Theory of electromagnetic insertion devices and the corresponding synchrotron radiation

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

Shumail, Muhammad; Tantawi, Sami G.

Permanent magnet insertion devices (IDs), which are the main radiation generating devices in synchrotron light sources and free-electron lasers, use a time-invariant but space-periodic magnetic field to wiggle relativistic electrons for short-wavelength radiation generation. Recently, a high power microwave based undulator has also been successfully demonstrated at SLAC which promises the advantage of dynamic tunability of radiation spectrum and polarization. Such IDs employ transverse elecromagnetic fields which are periodic in both space and time to undulate the electrons. In this paper we develop a detailed theory of the principle of electromagnetic IDs from first principles for both linear and circularmore » polarization modes. The electromagnetic equivalent definitions of undulator period (λ u) and undulator deflection parameter (K) are derived. In the inertial frame where the average momentum of the electron is zero, we obtain the figure-8-like trajectory for the linear polarization mode and the circular trajectory for the circular polarization mode. As a result, the corresponding radiation spectra and the intensity of harmonics is also calculated.« less

Theory of electromagnetic insertion devices and the corresponding synchrotron radiation

DOE PAGES

Shumail, Muhammad; Tantawi, Sami G.

2016-07-27

Permanent magnet insertion devices (IDs), which are the main radiation generating devices in synchrotron light sources and free-electron lasers, use a time-invariant but space-periodic magnetic field to wiggle relativistic electrons for short-wavelength radiation generation. Recently, a high power microwave based undulator has also been successfully demonstrated at SLAC which promises the advantage of dynamic tunability of radiation spectrum and polarization. Such IDs employ transverse elecromagnetic fields which are periodic in both space and time to undulate the electrons. In this paper we develop a detailed theory of the principle of electromagnetic IDs from first principles for both linear and circularmore » polarization modes. The electromagnetic equivalent definitions of undulator period (λ u) and undulator deflection parameter (K) are derived. In the inertial frame where the average momentum of the electron is zero, we obtain the figure-8-like trajectory for the linear polarization mode and the circular trajectory for the circular polarization mode. As a result, the corresponding radiation spectra and the intensity of harmonics is also calculated.« less

Translation and Rotation of Transformation Media under Electromagnetic Pulse

PubMed Central

Gao, Fei; Shi, Xihang; Lin, Xiao; Xu, Hongyi; Zhang, Baile

2016-01-01

It is well known that optical media create artificial geometry for light, and curved geometry acts as an effective optical medium. This correspondence originates from the form invariance of Maxwell’s equations, which recently has spawned a booming field called ‘transformation optics’. Here we investigate responses of three transformation media under electromagnetic pulses, and find that pulse radiation can induce unbalanced net force on transformation media, which will cause translation and rotation of transformation media although their final momentum can still be zero. Therefore, the transformation media do not necessarily stay the same after an electromagnetic wave passes through. PMID:27321246

Translation and Rotation of Transformation Media under Electromagnetic Pulse.

PubMed

Gao, Fei; Shi, Xihang; Lin, Xiao; Xu, Hongyi; Zhang, Baile

2016-06-20

It is well known that optical media create artificial geometry for light, and curved geometry acts as an effective optical medium. This correspondence originates from the form invariance of Maxwell's equations, which recently has spawned a booming field called 'transformation optics'. Here we investigate responses of three transformation media under electromagnetic pulses, and find that pulse radiation can induce unbalanced net force on transformation media, which will cause translation and rotation of transformation media although their final momentum can still be zero. Therefore, the transformation media do not necessarily stay the same after an electromagnetic wave passes through.

Sizing and Pointing of Solar Panels and for Solar Thermal Applications

Atmospheric Science Data Center

2014-09-25

... on horizontal surface (kWh/m2/day) Amount of electromagnetic energy (solar radiation) incident on the surface of the earth. ... on horizontal surface (kWh/m2/day) Amount of electromagnetic energy (solar radiation) incident on the surface of the earth ...

Fault current limiter with shield and adjacent cores

DOEpatents

Darmann, Francis Anthony; Moriconi, Franco; Hodge, Eoin Patrick

2013-10-22

In a fault current limiter (FCL) of a saturated core type having at least one coil wound around a high permeability material, a method of suppressing the time derivative of the fault current at the zero current point includes the following step: utilizing an electromagnetic screen or shield around the AC coil to suppress the time derivative current levels during zero current conditions.

The motion near L{sub 4} equilibrium point under non-point mass primaries

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

Huda, I. N., E-mail: ibnu.nurul@students.itb.ac.id; Utama, J. A.; Madley, D.

2015-09-30

The Circular Restricted Three-Body Problem (CRTBP) possesses five equilibrium points, that comprise three collinear (L{sub 1}, L{sub 2}, and L{sub 3}) and two triangular points (L{sub 4} and L{sub 5}). The classical study (with the primaries are point mass) suggests that the equilibrium points may cause the velocity of infinitesimal object relatively becomes zero and reveals the zero velocity curve. We study the motion of infinitesimal object near triangular equilibrium point (L{sub 4}) and determine its zero velocity curve. We extend the study by taking into account the effects of radiation of the bigger primary (q{sub 1} ≠ 1, q{submore » 2} = 1) and oblateness of the smaller primary (A{sub 1} = 0, A{sub 2} ≠ 0). The location of L{sub 4} is analytically derived then the stability of L{sub 4} and its zero velocity curves are studied numerically. Our study suggests that the oblateness and the radiation of primaries may affect the stability and zero velocity curve around L{sub 4}.« less

Schwinger mechanism in electromagnetic field in de Sitter spacetime

NASA Astrophysics Data System (ADS)

Bavarsad, Ehsan; Pyo Kim, Sang; Stahl, Clément; Xue, She-Sheng

2018-01-01

We investigate Schwinger scalar pair production in a constant electromagnetic field in de Sitter (dS) spacetime. We obtain the pair production rate, which agrees with the Hawking radiation in the limit of zero electric field in dS. The result describes how a cosmic magnetic field affects the pair production rate. In addition, using a numerical method we study the effect of the magnetic field on the induced current. We find that in the strong electromagnetic field the current has a linear response to the electric and magnetic fields, while in the infrared regime, is inversely proportional to the electric field and leads to infrared hyperconductivity.

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

Veklenko, B. A., E-mail: veklenkoba@yandex.ru

It is shown theoretically that the electromagnetic background of longitudinal zero oscillations of a temperature-degenerate electron–ion plasma in a thermodynamic equilibrium state resonantly distorts the wave functions of its electrons. This gives rise to a characteristic quantum frequency that nonanalytically depends on Planck’s constant ℏ. Vacuum phenomena in plasma attributed to zero oscillations turn out to be anomalously large. Quantum corrections to the transverse dielectric permittivity of a degenerate electron–ion plasma, which are nonanalytic with respect to ℏ and are attributed to the zero-point oscillations of the plasma, are determined.

Self field electromagnetism and quantum phenomena

NASA Astrophysics Data System (ADS)

Schatten, Kenneth H.

1994-07-01

Quantum Electrodynamics (QED) has been extremely successful inits predictive capability for atomic phenomena. Thus the greatest hope for any alternative view is solely to mimic the predictive capability of quantum mechanics (QM), and perhaps its usefulness will lie in gaining a better understanding of microscopic phenomena. Many ?paradoxes? and problematic situations emerge in QED. To combat the QED problems, the field of Stochastics Electrodynamics (SE) emerged, wherein a random ?zero point radiation? is assumed to fill all of space in an attmept to explain quantum phenomena, without some of the paradoxical concerns. SE, however, has greater failings. One is that the electromagnetic field energy must be infinit eto work. We have examined a deterministic side branch of SE, ?self field? electrodynamics, which may overcome the probelms of SE. Self field electrodynamics (SFE) utilizes the chaotic nature of electromagnetic emissions, as charges lose energy near atomic dimensions, to try to understand and mimic quantum phenomena. These fields and charges can ?interact with themselves? in a non-linear fashion, and may thereby explain many quantum phenomena from a semi-classical viewpoint. Referred to as self fields, they have gone by other names in the literature: ?evanesccent radiation?, ?virtual photons?, and ?vacuum fluctuations?. Using self fields, we discuss the uncertainty principles, the Casimir effects, and the black-body radiation spectrum, diffraction and interference effects, Schrodinger's equation, Planck's constant, and the nature of the electron and how they might be understood in the present framework. No new theory could ever replace QED. The self field view (if correct) would, at best, only serve to provide some understanding of the processes by which strange quantum phenomena occur at the atomic level. We discuss possible areas where experiments might be employed to test SFE, and areas where future work may lie.

Electronic zero-point fluctuation forces inside circuit components

PubMed Central

Leonhardt, Ulf

2018-01-01

One of the most intriguing manifestations of quantum zero-point fluctuations are the van der Waals and Casimir forces, often associated with vacuum fluctuations of the electromagnetic field. We study generalized fluctuation potentials acting on internal degrees of freedom of components in electrical circuits. These electronic Casimir-like potentials are induced by the zero-point current fluctuations of any general conductive circuit. For realistic examples of an electromechanical capacitor and a superconducting qubit, our results reveal the possibility of tunable forces between the capacitor plates, or the level shifts of the qubit, respectively. Our analysis suggests an alternative route toward the exploration of Casimir-like fluctuation potentials, namely, by characterizing and measuring them as a function of parameters of the environment. These tunable potentials may be useful for future nanoelectromechanical and quantum technologies. PMID:29719863

Localization of non-stationary sources of electromagnetic radiation with the aid of phasometry

NASA Technical Reports Server (NTRS)

Mersov, G. A.

1978-01-01

The possibility of localizing sources of electromagnetic radiation by measurement of the time of passage of the radiation or the measurement of its phase at various points of cosmic space, at which are located satellite observatories is examined. Algorithms are proposed for localization using two, three, and four astronomical observatories. The precision of the localization and several partial results of practical significance are deduced.

Propagation in and scattering from a matched metamaterial having a zero index of refraction.

PubMed

Ziolkowski, Richard W

2004-10-01

Planar metamaterials that exhibit a zero index of refraction have been realized experimentally by several research groups. Their existence stimulated the present investigation, which details the properties of a passive, dispersive metamaterial that is matched to free space and has an index of refraction equal to zero. Thus, unlike previous zero-index investigations, both the permittivity and permeability are zero here at a specified frequency. One-, two-, and three-dimensional source problems are treated analytically. The one- and two-dimensional source problem results are confirmed numerically with finite difference time domain (FDTD) simulations. The FDTD simulator is also used to treat the corresponding one- and two-dimensional scattering problems. It is shown that in both the source and scattering configurations the electromagnetic fields in a matched zero-index medium take on a static character in space, yet remain dynamic in time, in such a manner that the underlying physics remains associated with propagating fields. Zero phase variation at various points in the zero-index medium is demonstrated once steady-state conditions are obtained. These behaviors are used to illustrate why a zero-index metamaterial, such as a zero-index electromagnetic band-gap structured medium, significantly narrows the far-field pattern associated with an antenna located within it. They are also used to show how a matched zero-index slab could be used to transform curved wave fronts into planar ones.

Multiple scattered radiation emerging from continental haze layers. 1: Radiance, polarization, and neutral points

NASA Technical Reports Server (NTRS)

Kattawar, G. W.; Plass, G. N.; Hitzfelder, S. J.

1975-01-01

The complete radiation field is calculated for scattering layers of various optical thicknesses. Results obtained for Rayleigh and haze scattering are compared. Calculated radiances show differences as large as 23% compared to the approximate scalar theory of radiative transfer, while the same differences are approximately 0.1% for a continental haze phase function. The polarization of reflected and transmitted radiation is given for various optical thicknesses, solar zenith angles, and surface albedos. Two types of neutral points occur for aerosol phase functions. Rayleigh-like neutral points arise from zero polarization that occurs at scattering angles of 0 deg and 180 deg. For Rayleigh phase functions, the position of these points varies with the optical thickness of the scattering layer. Non-Rayleigh neutral points are associated with the zeros of polarization which occur between the end points of the single scattering curve, and are found over a wide range of azimuthal angles.

[Effect of electromagnetic radiation on discharge activity of neurons in the hippocampus CA1 in rats].

PubMed

Tong, Jun; Chen, Su; Liu, Xiang-Ming; Hao, Dong-Mei

2013-09-01

In order to explore effect of electromagnetic radiation on learning and memory ability of hippocampus neuron in rats, the changes in discharge patterns and overall electrical activity of hippocampus neuron after electromagnetic radiation were observed. Rat neurons discharge was recorded with glass electrode extracellular recording technology and a polygraph respectively. Radiation frequency of electromagnetic wave was 900 MHZ and the power was 10 W/m2. In glass electrode extracellular recording, the rats were separately irradiated for 10, 20, 30, 40, 50 and 60 min, every points repeated 10 times and updated interval of 1h, observing the changes in neuron discharge and spontaneous discharge patterns after electromagnetic radiation. In polygraph recording experiments, irradiation group rats for five days a week, 6 hours per day, repeatedly for 10 weeks, memory electrical changes in control group and irradiation group rats when they were feeding were repeatedly monitored by the implanted electrodes, observing the changes in peak electric digits and the largest amplitude in hippocampal CA1 area, and taking some electromagnetic radiation sampling sequence for correlation analysis. (1) Electromagnetic radiation had an inhibitory role on discharge frequency of the hippocampus CA1 region neurons. After electromagnetic radiation, discharge frequency of the hippocampus CA1 region neurons was reduced, but the changes in scale was not obvious. (2) Electromagnetic radiation might change the spontaneous discharge patterns of hippocampus CA1 region neurons, which made the explosive discharge pattern increased obviously. (3) Peak potential total number within 5 min in irradiation group was significantly reduced, the largest amplitude was less than that of control group. (4) Using mathematical method to make the correlation analysis of the electromagnetic radiation sampling sequence, that of irradiation group was less than that of control group, indicating that there was a tending to be inhibitory connection between neurons in irradiation group after electromagnetic radiation. Electromagnetic radiation may cause structure and function changes of transfer synaptic in global, make hippocampal CA1 area neurons change in the overall discharge characteristic and discharge patterns, thus lead to decrease in the ability of learning and memory.

Polariton excitation in epsilon-near-zero slabs: Transient trapping of slow light

NASA Astrophysics Data System (ADS)

Ciattoni, Alessandro; Marini, Andrea; Rizza, Carlo; Scalora, Michael; Biancalana, Fabio

2013-05-01

We numerically investigate the propagation of a spatially localized and quasimonochromatic electromagnetic pulse through a slab with a Lorentz dielectric response in the epsilon-near-zero regime, where the real part of the permittivity vanishes at the pulse carrier frequency. We show that the pulse is able to excite a set of virtual polariton modes supported by the slab, with the excitation undergoing a generally slow damping due to absorption and radiation leakage. Our numerical and analytical approaches indicate that in its transient dynamics the electromagnetic field displays the very same enhancement of the field component perpendicular to the slab, as in the monochromatic regime. The transient trapping is inherently accompanied by a significantly reduced group velocity ensuing from the small dielectric permittivity, thus providing an alternative platform for achieving control and manipulation of slow light.

Synchronous Controlled Switching by VCB with Electromagnetic Operation Mechanism

NASA Astrophysics Data System (ADS)

Horinouchi, Katsuhiko; Tsukima, Mitsuru; Tohya, Nobumoto; Inoue, Ryuuichi; Sasao, Hiroyuki

Synchronously controlled switching to suppress transient overvoltage and overcurrent resulting from when the circuit breakers on medium voltage systems are closed is described. Firstly, by simulation it is found that if the closing time is synchronously controlled so that the contacts of the circuit breaker close completely at the instant when the voltage across contacts of the breaker at each of the three individual phases are zero, the resulting overvoltage and overcurrent is significantly suppressed when compared to conventional three phase simultaneous closing. Next, an algorithm for determining the closing timing based on a forecasted voltage zero waveform, obtained from voltage sampling data, is presented. Finally, a synchronous closing experiment of voltage 22kV utilizing a controller to implement the algorithm and a VCB with an electromagnetic operation mechanism is presented. The VCB was successfully closed at the zero point within a tolerance range of 200 microseconds.

Multiple scattered radiation emerging from Rayleigh and continental haze layers. 1: Radiance, polarization, and neutral points.

PubMed

Kattawar, G W; Plass, G N; Hitzfelder, S J

1976-03-01

The complete radiation field including polarization is calculated by the matrix operator method for scattering layers of various optical thicknesses. Results obtained for Rayleigh scattering are compared with those for scattering from a continental haze. Radiances calculated using Stokes vectors show differences as large as 23% compared to the approximate scalar theory of radiative transfer, while the same differences are only of the order of 0.1% for a continental haze phase function. The polarization of the reflected and transmitted radiation is given for a wide range of optical thicknesses of the scattering layer, for various solar zenith angles, and various surface albedos. Two entirely different types of neutral points occur for aerosol phase functions. Rayleigh-like neutral points (RNP) arise from the zero polarization in single scattering that occurs for all phase functions at scattering angles of 0 degrees and 180 degrees . For Rayleigh phase functions, the position of the RNP varies appreciably with the optical thickness of the scattering layer. At low solar elevations there may be four RNP. For a continental haze phase function the position of the RNP in the reflected radiation shows only a small variation with the optical thickness, and the RNP exists in the transmitted radiation only for extremely small optical thicknesses. Another type of neutral point (NRNP) exists for aerosol phase functions. It is associated with the zeros of the single scattered polarization, which occur between the end points of the curve; these are called non-Rayleigh neutral points (NRNP). There may be from zero to four of these neutral points associated with each zero of the single scattering curve. They occur over a range of azimuthal angles, unlike the RNP that are in the principal plane only. The position of these neutral points is given as a function of solar angle and optical thickness.

ZERO-TIME INDICATOR

DOEpatents

Sander, H.H.

1960-08-30

The travel time of a nuclear shock wave from its point of origin to a location can be determined accurately by an apparatus for noting and comparably recording both zerotime, as indicated by the electromagnetic transient associated with the nuclear detonation, and shock wave arrival time.

Electric levitation using ϵ-near-zero metamaterials.

PubMed

Rodríguez-Fortuño, Francisco J; Vakil, Ashkan; Engheta, Nader

2014-01-24

The ability to manufacture metamaterials with exotic electromagnetic properties has potential for surprising new applications. Here we report how a specific type of metamaterial--one whose permittivity is near zero--exerts a repulsive force on an electric dipole source, resulting in levitation of the dipole. The phenomenon relies on the expulsion of the time-varying electric field from the metamaterial interior, resembling the perfect diamagnetic expulsion of magnetostatic fields. Leveraging this concept, we study some realistic requirements for the levitation or repulsion of a polarized particle radiating at any frequency, from microwave to optics.

Semiconductor photoelectrochemistry

NASA Technical Reports Server (NTRS)

Buoncristiani, A. M.; Byvik, C. E.

1983-01-01

Semiconductor photoelectrochemical reactions are investigated. A model of the charge transport processes in the semiconductor, based on semiconductor device theory, is presented. It incorporates the nonlinear processes characterizing the diffusion and reaction of charge carriers in the semiconductor. The model is used to study conditions limiting useful energy conversion, specifically the saturation of current flow due to high light intensity. Numerical results describing charge distributions in the semiconductor and its effects on the electrolyte are obtained. Experimental results include: an estimate rate at which a semiconductor photoelectrode is capable of converting electromagnetic energy into chemical energy; the effect of cell temperature on the efficiency; a method for determining the point of zero zeta potential for macroscopic semiconductor samples; a technique using platinized titanium dioxide powders and ultraviolet radiation to produce chlorine, bromine, and iodine from solutions containing their respective ions; the photoelectrochemical properties of a class of layered compounds called transition metal thiophosphates; and a technique used to produce high conversion efficiency from laser radiation to chemical energy.

Effect of inductive and capacitive coupling on the current–voltage characteristic and electromagnetic radiation from a system of Josephson junctions

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

Rahmonov, I. R., E-mail: rahmonov@theor.jinr.ru, E-mail: ilhom-tj@inbox.ru; Shukrinov, Yu. M.; Atanasova, P. Kh.

We have studied the current–voltage characteristic of a system of long Josephson junctions taking into account the inductive and capacitive coupling. The dependence of the average time derivative of the phase difference on the bias current and spatiotemporal dependences of the phase difference and magnetic field in each junction are considered. The possibility of branching of the current–voltage characteristic in the region of zero field step, which is associated with different numbers of fluxons in individual Josephson junctions, is demonstrated. The current–voltage characteristic of the system of Josephson junctions is compared with the case of a single junction, and itmore » is shown that the observed branching is due to coupling between the junctions. The intensity of electromagnetic radiation associated with motion of fluxons is calculated, and the effect of coupling between junctions on the radiation power is analyzed.« less

Maxwell-Faraday Stresses in Electromagnetic Fields and the Self-Force on a Uniformly Accelerating Point Charge

ERIC Educational Resources Information Center

Rowland, D. R.

2007-01-01

The physical analysis of a uniformly accelerating point charge provides a rich problem to explore in advanced courses in electrodynamics and relativity since it brings together fundamental concepts in relation to electromagnetic radiation, Einstein's equivalence principle and the inertial mass of field energy in ways that reveal subtleties in each…

First indication of the coherent unipolar diffraction radiation generated by relativistic electrons

NASA Astrophysics Data System (ADS)

Naumenko, G.; Shevelev, M.

2018-05-01

As is generally known, the integral of the electric field strength over all time for usual (bipolar) radiation is zero. The first demonstration of the possibility of unipolar radiation generation has been considered theoretically by Bessonov in 1981 [E.G. Bessonov, Zh. Eksp. Teor. Fiz. 80 (1981) 852]. According to this work, the unipolar radiation (or strange electromagnetic waves) is radiation for which the integral of the electric field strength over the entire duration of a pulse differs significantly from zero. Later, several theoretical papers devoted to this phenomenon have appeared in the literature, where authors investigated mainly synchrotron radiation. However, despite the critical interest, the experimental investigations ignored this effect. In this paper we present results of the first experimental investigation of the unipolar radiation generated by a relativistic electron beam. To detect the unipolar radiation the detector that is sensitive to the selected direction of the electric field strength has been elaborated and tested. We used a designed detector to observe the coherent backward diffraction radiation appearing when a bunched electron beam travels in the vicinity of a flat conductive target. The asymmetry of the electric field strength of the coherent backward diffraction radiation has been demonstrated.

Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.

PubMed

Wu, Juan; Xu, Yong; Ma, Jun

2017-01-01

As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.

Lévy noise improves the electrical activity in a neuron under electromagnetic radiation

PubMed Central

Wu, Juan; Ma, Jun

2017-01-01

As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected. PMID:28358824

Processing Waveform-Based NDE

NASA Technical Reports Server (NTRS)

Roth, Donald J (Inventor)

2011-01-01

A computer implemented process for simultaneously measuring the velocity of terahertz electromagnetic radiation in a dielectric material sample without prior knowledge of the thickness of the sample and for measuring the thickness of a material sample using terahertz electromagnetic radiation in a material sample without prior knowledge of the velocity of the terahertz electromagnetic radiation in the sample is disclosed and claimed. Utilizing interactive software the process evaluates, in a plurality of locations, the sample for microstructural variations and for thickness variations and maps the microstructural and thickness variations by location. A thin sheet of dielectric material may be used on top of the sample to create a dielectric mismatch. The approximate focal point of the radiation source (transceiver) is initially determined for good measurements.

Simultaneous Noncontact Precision Imaging of Microstructural and Thickness Variation in Dielectric Materials Using Terahertz Energy

NASA Technical Reports Server (NTRS)

Roth, Donald J (Inventor)

2011-01-01

A process for simultaneously measuring the velocity of terahertz electromagnetic radiation in a dielectric material sample without prior knowledge of the thickness of the sample and for measuring the thickness of a material sample using terahertz electromagnetic radiation in a material sample without prior knowledge of the velocity of the terahertz electromagnetic radiation in the sample is disclosed and claimed. The process evaluates, in a plurality of locations, the sample for microstructural variations and for thickness variations and maps the microstructural and thickness variations by location. A thin sheet of dielectric material may be used on top of the sample to create a dielectric mismatch. The approximate focal point of the radiation source (transceiver) is initially determined for good measurements.

Design of compact electromagnetic impulse radiating antenna for melanoma treatment.

PubMed

Arockiasamy, Petrishia; Mohan, Sasikala

2016-01-01

Cancer therapy is one of the several new applications which use nanosecond and subnanosecond high voltage pulses. New treatment based on electromagnetic (EM) fields have been developed as non-surgical and minimally invasive treatments of tumors. In particular, subnanosecond pulses can introduce important non-thermal changes in cell biology, especially the permeabilization of the cell membrane. The motivation behind this work is to launch intense subnanosecond pulses to the target (tumors) non-invasively. This works focuses on the design of a compact intense pulsed EM radiating antenna. In tense EM waves radiated at the first focal point of the Prolate Spheroidal Reflector (PSR) are focused at the second focal point where the target (tumor) is present. Two antennas with PSR but fed with different compact wave radiator are designed to focus pulsed field at the second focal point. The PSR with modified bicone antenna feed and PSR with elliptically tapered horn antenna feed are designed. The design parameters and radiation performance are discussed.

Multiple scattered radiation emerging from Rayleigh and continental haze layers. I - Radiance, polarization, and neutral points

NASA Technical Reports Server (NTRS)

Kattawar, G. W.; Plass, G. N.; Hitzfelder, S. J.

1976-01-01

The matrix operator method was used to calculate the polarization of radiation scattered on layers of various optical thicknesses, with results compared for Rayleigh scattering and for scattering from a continental haze. In both cases, there are neutral points arising from the zeros of the polarization of single scattered photons at scattering angles of zero and 180 degrees. The angular position of these Rayleigh-like neutral points (RNP) in the sky shows appreciable variation with the optical thickness of the scattering layer for a Rayleigh phase matrix, but only a small variation for haze L phase matrix. Another type of neutral point exists for non-Rayleigh phase functions that is associated with the zeros of the polarization for single scattering which occurs between the end points of the curve. A comparison of radiances calculated from the complete theory of radiative transfer using Stokes vectors with those obtained from the scalar theory shows that differences of the order of 23% may be obtained for Rayleigh scattering, while the largest difference found for a haze L phase function was of the order of 0.1%.

Effects of a PID Control System on Electromagnetic Fields in an nEDM Experiment

NASA Astrophysics Data System (ADS)

Molina, Daniel

2017-09-01

The Kellogg Radiation Laboratory is currently testing a prototype for an experiment that hopes to identify the electric dipole moment of the neutron. As part of this testing, we have developed a PID (proportional, integral, derivative) feedback system that uses large coils to fix the value of local external magnetic fields, up to linear gradients. PID algorithms compare the current value to a set-point and use the integral and derivative of the field with respect to the set-point to maintain constant fields. We have also developed a method for zeroing linear gradients within the experimental apparatus. In order to determine the performance of the PID algorithm, measurements of both the internal and external fields were obtained with and without the algorithm running, and these results were compared for noise and time stability. We have seen that the PID algorithm can reduce the effect of disturbance to the field by a factor of 10.

Synchrotron Radiation II.

ERIC Educational Resources Information Center

MOSAIC, 1978

1978-01-01

Synchrotron radiation is a unique form of radiation that spans the electro-magnetic spectrum from X-rays through the ultraviolet and visible into the infrared. Tunable monochromators enable scientists to select a narrow band of wavelengths at any point in the spectrum. (Author/BB)

Creation of an anti-imaging system using binary optics.

PubMed

Wang, Haifeng; Lin, Jian; Zhang, Dawei; Wang, Yang; Gu, Min; Urbach, H P; Gan, Fuxi; Zhuang, Songlin

2016-09-13

We present a concealing method in which an anti-point spread function (APSF) is generated using binary optics, which produces a large-scale dark area in the focal region that can hide any object located within it. This result is achieved by generating two identical PSFs of opposite signs, one consisting of positive electromagnetic waves from the zero-phase region of the binary optical element and the other consisting of negative electromagnetic waves from the pi-phase region of the binary optical element.

Creation of an anti-imaging system using binary optics

PubMed Central

Wang, Haifeng; Lin, Jian; Zhang, Dawei; Wang, Yang; Gu, Min; Urbach, H. P.; Gan, Fuxi; Zhuang, Songlin

2016-01-01

We present a concealing method in which an anti-point spread function (APSF) is generated using binary optics, which produces a large-scale dark area in the focal region that can hide any object located within it. This result is achieved by generating two identical PSFs of opposite signs, one consisting of positive electromagnetic waves from the zero-phase region of the binary optical element and the other consisting of negative electromagnetic waves from the pi-phase region of the binary optical element. PMID:27620068

Homodyning and heterodyning the quantum phase

NASA Technical Reports Server (NTRS)

Dariano, Giacomo M.; Macchiavello, C.; Paris, M. G. A.

1994-01-01

The double-homodyne and the heterodyne detection schemes for phase shifts between two synchronous modes of the electromagnetic field are analyzed in the framework of quantum estimation theory. The probability operator-valued measures (POM's) of the detectors are evaluated and compared with the ideal one in the limit of strong local reference oscillator. The present operational approach leads to a reasonable definition of phase measurement, whose sensitivity is actually related to the output r.m.s. noise of the photodetector. We emphasize that the simple-homodyne scheme does not correspond to a proper phase-shift measurements as it is just a zero-point detector. The sensitivity of all detection schemes are optimized at fixed energy with respect to the input state of radiation. It is shown that the optimal sensitivity can be actually achieved using suited squeezed states.

Observable consequences of zero-point energy

NASA Astrophysics Data System (ADS)

Sen, Siddhartha; Gupta, Kumar S.

2017-12-01

Spectral line widths, the Lamb shift and the Casimir effect are generally accepted to be observable consequences of the zero-point electromagnetic (ZPEM) fields. A new class of observable consequences of ZPEM field at the mesoscopic scale were recently proposed and observed. Here, we extend this class of observable effects and predict that mesoscopic water layers should have a high value for its solid-liquid phase transition temperature, as illustrated by water inside a single-walled carbon nanotube (CNT). For this case, our analysis predicts that the phase transition temperature scales inversely with the square of the effective radius available for the water flow within the CNT.

Radiated interference in rapid transit systems. volume 2. suggested test procedures.

DOT National Transportation Integrated Search

1987-06-30

The purpose of this report is to present a suggested test procedure for measuring the radiated electromagnetic interference (EMI) emanating from rail transit systems. This report points out that, unlike inductive and conductive EMI, radiated EMI has ...

Extension of On-Surface Radiation Condition (OSRC) theory to full-vector electromagnetic wave scattering by three-dimensional conducting, dielectric, and coated targets

NASA Astrophysics Data System (ADS)

Taflove, Allen; Umashankar, Korada R.

1993-08-01

This project introduced radiation boundary condition (RBC) and absorbing boundary condition (ABC) theory to the engineering electromagnetics community. An approximate method for obtaining the scattering of 2-D and 3-D bodies, the on-surface radiation condition (OSRC) method, was formulated and validated. RBC's and ABC's were shown to work well at points closer to scatterers than anyone had expected. Finite-difference time domain (FD-TD) methods exploiting these ABC's were pursued for applications in scattering, radiation, penetration, biomedical studies, and nonlinear optics. Multiprocessing supercomputer software was developed for FD-TD, leading to the largest scale detailed electromagnetic wave interaction models ever conducted, including entire jet fighter aircraft modeled for radar cross section (RCS) at UHF frequencies up to 500 MHz.

Combination of ray-tracing and the method of moments for electromagnetic radiation analysis using reduced meshes

NASA Astrophysics Data System (ADS)

Delgado, Carlos; Cátedra, Manuel Felipe

2018-05-01

This work presents a technique that allows a very noticeable relaxation of the computational requirements for full-wave electromagnetic simulations based on the Method of Moments. A ray-tracing analysis of the geometry is performed in order to extract the critical points with significant contributions. These points are then used to generate a reduced mesh, considering the regions of the geometry that surround each critical point and taking into account the electrical path followed from the source. The electromagnetic analysis of the reduced mesh produces very accurate results, requiring a fraction of the resources that the conventional analysis would utilize.

Search for magnetic monopoles in lunar material.

NASA Technical Reports Server (NTRS)

Eberhard, P. H.; Ross, R. R.; Alvarez, L. W.; Watt, R. D.

1971-01-01

A search for magnetic monopoles in lunar material has been performed by the electromagnetic measurement of the magnetic charge of samples. All measurements were found consistent with zero charge for all samples and inconsistent with any other value allowed by the Dirac theory. Upper limits are determined for the monopole flux in cosmic radiation and for the pair-production cross section in proton-nucleon collisions.

Measurement and mapping of the GSM-based electromagnetic pollution in the Black Sea region of Turkey.

PubMed

Tuysuz, Burak; Mahmutoglu, Yigit

2017-01-01

Electromagnetic pollution caused by mobile communication devices, a new form of environmental pollution, has been one of the most concerning problems to date. Consequences of long-term exposure to the electromagnetic radiation caused by cell phone towers are still unknown and can potentially be a new health hazard. It is important to measure, analyze and map the electromagnetic radiation levels periodically because of the potential risks. The electromagnetic pollution maps can be used for the detection of diseases caused by the radiation. With the help of the radiation maps of different regions, comparative analysis can be provided and distribution of the diseases can be investigated. In this article, Global System for Mobile communication (GSM)-based electromagnetic pollution map of the Rize Providence, which has high cancer rates because of the Chernobyl nuclear explosion, is generated. First, locations of the GSM base stations are identified and according to the antenna types of the base stations, safety distances are determined. Subsequently, 155 measurements are taken during November 2014 from the nearest living quarters of the Rize city center in Turkey. The measurements are then assessed statistically. Thenceforth, for visual judgment of the determined statistics, collected measurements are presented on the map. It is observed that national limits are not exceeded, but it is also discovered that the safety distance is waived at some of the measurement points and above the average radiation levels are noted. Even if the national limits are not exceeded, the long-term effects of the exposition to the electromagnetic radiation can cause serious health problems.

Sonoluminescence Explained by the Standpoint of Coherent Quantum Vacuum Dynamics and its Prospects for Energy Production

NASA Astrophysics Data System (ADS)

Maxmilian Caligiuri, Luigi; Musha, Takaaki

Sonoluminescence, or its more frequently studied version known as Single Bubble Sonoluminescence, consisting in the emission of light by a collapsing bubble in water under ultrasounds, represents one of the most challenging and interesting phenomenon in theoretical physics. In fact, despite its relatively easy reproducibility in a simple laboratory, its understanding within the commonly accepted picture of condensed matter remained so far unsatisfactory. On the other hand, the possibility to control the physical process involved in sonoluminescence, representing a sort of nuclear fusion on small scale, could open unthinkable prospects of free energy production from water. Different explanations has been proposed during the past years considering, in various way, the photoemission to be related to electromagnetic Zero Point Field energy dynamics, by considering the bubble surface as a Casimir force boundary. More recently a model invoking Cherenkov radiation emission from superluminal photons generated in quantum vacuum has been successfully proposed. In this paper it will be shown that the same results can be more generally explained and quantitative obtained within a QED coherent dynamics of quantum vacuum, according to which the electromagnetic energy of the emitted photons would be related to the latent heat involved in the phase transition from water's vapor to liquid phase during the bubble collapse. The proposed approach could also suggest an explanation of a possible mechanism of generation of faster than light (FTL) photons required to start Cherenkov radiation as well as possible applications to energy production from quantum vacuum.

Propagation and Linear Mode Conversion of Magnetosonic and Electromagnetic Ion Cyclotron Waves in the Radiation Belts

NASA Astrophysics Data System (ADS)

Horne, R. B.; Yoshizumi, M.

2017-12-01

Magnetosonic waves and electromagnetic ion cyclotron (EMIC) waves are important for electron acceleration and loss from the radiation belts. It is generally understood that these waves are generated by unstable ion distributions that form during geomagnetically disturbed times. Here we show that magnetosonic waves could be a source of EMIC waves as a result of propagation and a process of linear mode conversion. The converse is also possible. We present ray tracing to show how magnetosonic (EMIC) waves launched with large (small) wave normal angles can reach a location where the wave normal angle is zero and the wave frequency equals the so-called cross-over frequency whereupon energy can be converted from one mode to another without attenuation. While EMIC waves could be a source of magnetosonic waves below the cross-over frequency magnetosonic waves could be a source of hydrogen band waves but not helium band waves.

Evaluation of Information Leakage from Cryptographic Hardware via Common-Mode Current

NASA Astrophysics Data System (ADS)

Hayashi, Yu-Ichi; Homma, Naofumi; Mizuki, Takaaki; Sugawara, Takeshi; Kayano, Yoshiki; Aoki, Takafumi; Minegishi, Shigeki; Satoh, Akashi; Sone, Hideaki; Inoue, Hiroshi

This paper presents a possibility of Electromagnetic (EM) analysis against cryptographic modules outside their security boundaries. The mechanism behind the information leakage is explained from the view point of Electromagnetic Compatibility: electric fluctuation released from cryptographic modules can conduct to peripheral circuits based on ground bounce, resulting in radiation. We demonstrate the consequence of the mechanism through experiments where the ISO/IEC standard block cipher AES (Advanced Encryption Standard) is implemented on an FPGA board and EM radiations from power and communication cables are measured. Correlation Electromagnetic Analysis (CEMA) is conducted in order to evaluate the information leakage. The experimental results show that secret keys are revealed even though there are various disturbing factors such as voltage regulators and AC/DC converters between the target module and the measurement points. We also discuss information-suppression techniques as electrical-level countermeasures against such CEMAs.

A measurement technique to determine the calibration accuracy of an electromagnetic tracking system to radiation isocenter.

PubMed

Litzenberg, Dale W; Gallagher, Ian; Masi, Kathryn J; Lee, Choonik; Prisciandaro, Joann I; Hamstra, Daniel A; Ritter, Timothy; Lam, Kwok L

2013-08-01

To present and characterize a measurement technique to quantify the calibration accuracy of an electromagnetic tracking system to radiation isocenter. This technique was developed as a quality assurance method for electromagnetic tracking systems used in a multi-institutional clinical hypofractionated prostate study. In this technique, the electromagnetic tracking system is calibrated to isocenter with the manufacturers recommended technique, using laser-based alignment. A test patient is created with a transponder at isocenter whose position is measured electromagnetically. Four portal images of the transponder are taken with collimator rotations of 45° 135°, 225°, and 315°, at each of four gantry angles (0°, 90°, 180°, 270°) using a 3×6 cm2 radiation field. In each image, the center of the copper-wrapped iron core of the transponder is determined. All measurements are made relative to this transponder position to remove gantry and imager sag effects. For each of the 16 images, the 50% collimation edges are identified and used to find a ray representing the rotational axis of each collimation edge. The 16 collimator rotation rays from four gantry angles pass through and bound the radiation isocenter volume. The center of the bounded region, relative to the transponder, is calculated and then transformed to tracking system coordinates using the transponder position, allowing the tracking system's calibration offset from radiation isocenter to be found. All image analysis and calculations are automated with inhouse software for user-independent accuracy. Three different tracking systems at two different sites were evaluated for this study. The magnitude of the calibration offset was always less than the manufacturer's stated accuracy of 0.2 cm using their standard clinical calibration procedure, and ranged from 0.014 to 0.175 cm. On three systems in clinical use, the magnitude of the offset was found to be 0.053±0.036, 0.121±0.023, and 0.093±0.013 cm. The method presented here provides an independent technique to verify the calibration of an electromagnetic tracking system to radiation isocenter. The calibration accuracy of the system was better than the 0.2 cm accuracy stated by the manufacturer. However, it should not be assumed to be zero, especially for stereotactic radiation therapy treatments where planning target volume margins are very small.

Electromagnetic fields radiated from a lightning return stroke - Application of an exact solution to Maxwell's equations

NASA Technical Reports Server (NTRS)

Le Vine, D. M.; Meneghini, R.

1978-01-01

A solution is presented for the electromagnetic fields radiated by an arbitrarily oriented current filament over a conducting ground plane in the case where the current propagates along the filament at the speed of light, and this solution is interpreted in terms of radiation from lightning return strokes. The solution is exact in the fullest sense; no mathematical approximations are made, and the governing differential equations and boundary conditions are satisfied. The solution has the additional attribute of being specified in closed form in terms of elementary functions. This solution is discussed from the point of view of deducing lightning current wave forms from measurements of the electromagnetic fields and understanding the effects of channel tortuosity on the radiated fields. In addition, it is compared with two approximate solutions, the traditional moment approximation and the Fraunhofer approximation, and a set of criteria describing their applicability are presented and interpreted.

Radiation-like scalar field and gauge fields in cosmology for a theory with dynamical time

NASA Astrophysics Data System (ADS)

Benisty, David; Guendelman, E. I.

2016-09-01

Cosmological solutions with a scalar field behaving as radiation are obtained, in the context of gravitational theory with dynamical time. The solution requires the spacial curvature of the universe k, to be zero, unlike the standard radiation solutions, which do not impose any constraint on the spatial curvature of the universe. This is because only such k = 0 radiation solutions pose a homothetic Killing vector. This kind of theory can be used to generalize electromagnetism and other gauge theories, in curved spacetime, and there are no deviations from standard gauge field equation (like Maxwell equations) in the case there exist a conformal Killing vector. But there could be departures from Maxwell and Yang-Mills equations, for more general spacetimes.

Low power electromagnetic flowmeter providing accurate zero set

NASA Technical Reports Server (NTRS)

Fryer, T. B. (Inventor)

1971-01-01

A low power, small size electromagnetic flowmeter system is described which produces a zero output signal for zero flow. The system comprises an air core type electromagnetic flow transducer, a field current supply circuit for the transducer coils and a pre-amplifier and demodulation circuit connected to the output of the transducer. To prevent spurious signals at zero flow, separate, isolated power supplies are provided for the two circuits. The demodulator includes a pair of synchronous rectifiers which are controlled by signals from the field current supply circuit. Pulse transformer connected in front of the synchronous rectifiers provide isolation between the two circuits.

Force approach to radiation reaction

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

López, Gustavo V., E-mail: gulopez@udgserv.cencar.udg.mx

The difficulty of the usual approach to deal with the radiation reaction is pointed out, and under the condition that the radiation force must be a function of the external force and is zero whenever the external force be zero, a new and straightforward approach to radiation reaction force and damping is proposed. Starting from the Larmor formula for the power radiated by an accelerated charged particle, written in terms of the applied force instead of the acceleration, an expression for the radiation force is established in general, and applied to the examples for the linear and circular motion ofmore » a charged particle. This expression is quadratic in the magnitude of the applied force, inversely proportional to the speed of the charged particle, and directed opposite to the velocity vector. This force approach may contribute to the solution of the very old problem of incorporating the radiation reaction to the motion of the charged particles, and future experiments may tell us whether or not this approach point is in the right direction.« less

Meridian is a three-dimensional network from bio-electromagnetic radiation interference: an interference hypothesis of meridian.

PubMed

Han, Jinxiang

2012-03-01

An electromagnetic radiation field within a biological organism is characterized by non-local interference. The interfering beams form a unitary tridimensional network with beams of varying intensity, also called striae, which are distributed on the organism surface. These striae are equivalent to semi-reflectors. The striae carry bio-information of corresponding organs and, thus, integrate all tissues, and organs of the organism. The longitudinal striae are classified as channels, while the transverse striae are collaterals. The acupoints are seen as the points where electromagnetic interfering striae intersect or converge. This hypothesis builds a foundation to understand the traditional Chinese medicine, including acupuncture, from the perspective of scientific knowledge.

AC-driven bilayer graphene: quasienergy spectrum of electrons and generation of soliton-like electromagnetic pulse

NASA Astrophysics Data System (ADS)

Kukhar, Egor I.

2018-01-01

Quasienergy spectrum of electrons in biased bigraphene subjected to the linear polarized high-frequency electromagnetic radiation has been derived. Quasienergy bands of ac-driven bigraphene have been investigated. Dynamical appearing of the saddle points in band structure of biased bigraphene and energy gap modification have been predicted. Electromagnetic field equation has been written using obtained quasienergy spectrum. The solution corresponding to the soliton-like electromagnetic wave has been obtained. The conditions of soliton-like wave generation in ac-driven bigraphene have been discussed.

Radiation-reaction force on a small charged body to second order

NASA Astrophysics Data System (ADS)

Moxon, Jordan; Flanagan, Éanna

2018-05-01

In classical electrodynamics, an accelerating charged body emits radiation and experiences a corresponding radiation-reaction force, or self-force. We extend to higher order in the total charge a previous rigorous derivation of the electromagnetic self-force in flat spacetime by Gralla, Harte, and Wald. The method introduced by Gralla, Harte, and Wald computes the self-force from the Maxwell field equations and conservation of stress-energy in a limit where the charge, size, and mass of the body go to zero, and it does not require regularization of a singular self-field. For our higher-order computation, an adjustment of the definition of the mass of the body is necessary to avoid including self-energy from the electromagnetic field sourced by the body in the distant past. We derive the evolution equations for the mass, spin, and center-of-mass position of the body through second order. We derive, for the first time, the second-order acceleration dependence of the evolution of the spin (self-torque), as well as a mixing between the extended body effects and the acceleration-dependent effects on the overall body motion.

Observation of acoustic Dirac-like cone and double zero refractive index

PubMed Central

Dubois, Marc; Shi, Chengzhi; Zhu, Xuefeng; Wang, Yuan; Zhang, Xiang

2017-01-01

Zero index materials where sound propagates without phase variation, holds a great potential for wavefront and dispersion engineering. Recently explored electromagnetic double zero index metamaterials consist of periodic scatterers whose refractive index is significantly larger than that of the surrounding medium. This requirement is fundamentally challenging for airborne acoustics because the sound speed (inversely proportional to the refractive index) in air is among the slowest. Here, we report the first experimental realization of an impedance matched acoustic double zero refractive index metamaterial induced by a Dirac-like cone at the Brillouin zone centre. This is achieved in a two-dimensional waveguide with periodically varying air channel that modulates the effective phase velocity of a high-order waveguide mode. Using such a zero-index medium, we demonstrated acoustic wave collimation emitted from a point source. For the first time, we experimentally confirm the existence of the Dirac-like cone at the Brillouin zone centre. PMID:28317927

Nonlinear interferometric vibrational imaging

NASA Technical Reports Server (NTRS)

Boppart, Stephen A. (Inventor); Marks, Daniel L. (Inventor)

2009-01-01

A method of examining a sample, which includes: exposing a reference to a first set of electromagnetic radiation, to form a second set of electromagnetic radiation scattered from the reference; exposing a sample to a third set of electromagnetic radiation to form a fourth set of electromagnetic radiation scattered from the sample; and interfering the second set of electromagnetic radiation and the fourth set of electromagnetic radiation. The first set and the third set of electromagnetic radiation are generated from a source; at least a portion of the second set of electromagnetic radiation is of a frequency different from that of the first set of electromagnetic radiation; and at least a portion of the fourth set of electromagnetic radiation is of a frequency different from that of the third set of electromagnetic radiation.

Electromagnetic forces in negative-refractive-index metamaterials: A first-principles study

NASA Astrophysics Data System (ADS)

Yannopapas, Vassilios; Galiatsatos, Pavlos G.

2008-04-01

According to the theory of Veselago, when a particle immersed within a metamaterial with negative refractive index is illuminated by plane wave, it experiences a reversed radiation force due to the antiparallel directions of the phase velocity and energy flow. By employing an ab initio method, we show that, in the limit of zero losses, the effect of reversed radiation pressure is generally true only for the specular beam. Waves generated by diffraction of the incident light at the surface of the slab of the metamaterial can produce a total force which is parallel to the radiation flow. However, when the actual losses of the materials are taken into account, the phenomenon of reversed radiation force is evident within the whole range of a negative refractive index band.

A new method to obtain narrowband emission from a broadband current using increased impedance of plasma-like media (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hur, Min Sup; Ersfeld, Bernhard; Noble, Adam; Suk, Hyyong; Jaroszynski, Dino A.

2017-05-01

In conventional radiation sources, narrowband radiation emission can be obtained by narrowband current oscillation. Usually the spectrum of the oscillating current is made narrow by a large or complicated structure for wave-particle interaction. One good example is the beam-undulator system. In this presentation, we introduce a new method to obtain a radiation emission with a well-collimated frequency without changing the broadband nature of a given current source. The method is based on our recent discovery of the new physical properties of the cut-off phenomenon, which broadly exists in general plasma-like media, such as plasma, waveguide, or photonic crystal, etc. A common feature of these media is the Bohm-Gross dispersion relation, which has a frequency condition to make the wavenumber zero. In the zero-wavenumber state, an electromagnetic wave cannot propagate through the medium, but instead, is reflected (i.e. cut-off). In regular steady-state analysis, the cut-off condition is characterized by infinite radiation impedance. An interesting question here is what would happen to the radiation power, if a non-zero current oscillating with the cut-off frequency were enforced in a medium (a current source, in contrast with the regular voltage source). A regular steady-state analysis for this situation leads to infinite power of radiation from Ohm's law. We could solve such a paradoxical situation by analyzing the non-steady-state system; we found that the system can be described by a time-dependent Schroedinger equation with an external driving term. The solution of this equation shows a temporally growing electromagnetic field. When this concept is extended to a generally broadband current source, the spectral density at the cut-off frequency can be selectively enhanced (selectively enhanced emission, SEE). Hence a general broadband radiation source can be easily converted to a narrowband source by enclosing the system with a plasma-like medium. The current source seems to exist in many radiation systems with a low driver-to-emission efficiency. When the current is determined predominantly by the driver (for examples, laser pulses), while the feedback from the emitted field is weak, such current can be considered as a quasi-current source, We present a few examples (mostly from PIC simulations) to demonstrate the SEE; two-color-driven THz system enclosed by a tapered waveguide, THz emission from a magnetized plasma, and re-interpretation of experimental data. Those examples show that quasi-current source can be found in practical systems, and the SEE mechanism works.

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

Hajian, Hodjat, E-mail: hodjat.hajian@bilkent.edu.tr; Ozbay, Ekmel; Department of Physics, Bilkent University, 06800 Ankara

Certain types of photonic crystals with Dirac cones at the Γ point of their band structure have a zero effective index of refraction at Dirac cone frequency. Here, by an appropriate design of the photonic structure, we obtain a strong coupling between modes around the Dirac cone frequency of an all-dielectric zero-index photonic crystal and the guided ones supported by a photonic crystal waveguide. Consequently, we experimentally demonstrate that the presence of the zero-index photonic crystal at the inner side of the photonic crystal waveguide leads to an enhancement in the transmission of some of the guided waves passing throughmore » this hybrid system. Moreover, those electromagnetic waves extracted from the structure with enhanced transmission exhibit high directional beaming due to the presence of the zero-index photonic crystal at the outer side of the photonic crystal waveguide.« less

Steady bound electromagnetic eigenstate arises in a homogeneous isotropic linear metamaterial with zero-real-part-of-impedance and nonzero-imaginary-part-of-wave-vector

NASA Astrophysics Data System (ADS)

Chen, Jiangwei; Dai, Yuyao; Yan, Lin; Zhao, Huimin

2018-04-01

In this paper, we shall demonstrate theoretically that steady bound electromagnetic eigenstate can arise in an infinite homogeneous isotropic linear metamaterial with zero-real-part-of-impedance and nonzero-imaginary-part-of-wave-vector, which is partly attributed to that, here, nonzero-imaginary-part-of-wave-vector is not involved with energy losses or gain. Altering value of real-part-of-impedance of the metamaterial, the bound electromagnetic eigenstate may become to be a progressive wave. Our work may be useful to further understand energy conversion and conservation properties of electromagnetic wave in the dispersive and absorptive medium and provides a feasible route to stop, store and release electromagnetic wave (light) conveniently by using metamaterial with near-zero-real-part-of-impedance.

Creation of quasi-Dirac points in the Floquet band structure of bilayer graphene.

PubMed

Cheung, W M; Chan, K S

2017-06-01

We study the Floquet quasi-energy band structure of bilayer graphene when it is illuminated by two laser lights with frequencies [Formula: see text] and [Formula: see text] using Floquet theory. We focus on the dynamical gap formed by the conduction band with Floquet index  =  -1 and the valence band with Floquet index  =  +1 to understand how Dirac points can be formed. It is found that the dynamical gap does not have rotation symmetry in the momentum space, and quasi-Dirac points, where the conduction and valence bands almost touch, can be created when the dynamical gap closes along some directions with suitably chosen radiation parameters. We derive analytical expressions for the direction dependence of the dynamical gaps using Lowdin perturbation theory to gain a better understanding of the formation of quasi-Dirac points. When both radiations are circularly polarized, the gap can be exactly zero along some directions, when only the first and second order perturbations are considered. Higher order perturbations can open a very small gap in this case. When both radiations are linearly polarized, the gap can be exactly zero up to the fourth order perturbation and more than one quasi-Dirac point is formed. We also study the electron velocity around a dynamical gap and show that the magnitude of the velocity drops to values close to zero when the k vector is near to the gap minimum. The direction of the velocity also changes around the gap minimum, and when the gap is larger in value the change in the velocity direction is more gradual. The warping effect does not affect the formation of a Dirac point along the k x axis, while it prevents its formation when there is phase shift between the two radiations.

FIBER AND INTEGRATED OPTICS. OTHER TOPICS IN QUANTUM ELECTRONICS: Modulation method for reducing long-term drift of the emission frequency of an He-Ne laser (λ = 0.63 μm) generating two orthogonally polarized electromagnetic waves

NASA Astrophysics Data System (ADS)

Vitushkin, L. F.; Zakharenko, Yu G.; Smirnov, M. Z.

1990-05-01

Theoretical and experimental investigations were made of the principal physical factors responsible for a long-term drift of the frequency of the radiation generated in a stabilized two-frequency He-Ne laser with internal mirrors, emitting two orthogonally polarized electromagnetic waves. When zero difference between the intensities was controlled by a modulation method and the frequency was set before each measurement, a long-term (over a period of a year) frequency drift did not exceed 10 - 8, but in the absence of such control the drift could reach 5 × 10 - 8.

Effects of a reentry plasma sheath on the beam pointing properties of an array antenna

NASA Astrophysics Data System (ADS)

Bai, Bowen; Liu, Yanming; Lin, Xiaofang; Li, Xiaoping

2018-03-01

The reduction in the gain of an on-board antenna caused by a reentry plasma sheath is an important effect that contributes to the reentry "blackout" problem. Using phased array antenna and beamforming technology could provide higher gain and an increase in the communication signal intensity. The attenuation and phase delay of the electromagnetic (EM) waves transmitting through the plasma sheath are direction-dependent, and the radiation pattern of the phased array antenna is affected, leading to a deviation in the beam pointing. In this paper, the far-field pattern of a planar array antenna covered by a plasma sheath is deduced analytically by considering both refraction and mutual coupling effects. A comparison between the analytic results and the results from an electromagnetic simulation is carried out. The effect of the plasma sheath on the radiation pattern and the beam pointing errors of the phased array antenna is studied systematically, and the derived results could provide useful information for the correction of pointing errors.

Discrimination between pre-seismic electromagnetic anomalies and solar activity effects

NASA Astrophysics Data System (ADS)

Koulouras, G.; Balasis, G.; Kiourktsidis, I.; Nannos, E.; Kontakos, K.; Stonham, J.; Ruzhin, Y.; Eftaxias, K.; Cavouras, D.; Nomicos, C.

2009-04-01

Laboratory studies suggest that electromagnetic emissions in a wide frequency spectrum ranging from kilohertz (kHz) to very high megahertz (MHz) frequencies are produced by the opening of microcracks, with the MHz radiation appearing earlier than the kHz radiation. Earthquakes are large-scale fracture phenomena in the Earth's heterogeneous crust. Thus, the radiated kHz-MHz electromagnetic emissions are detectable not only in the laboratory but also at a geological scale. Clear MHz-to-kHz electromagnetic anomalies have been systematically detected over periods ranging from a few days to a few hours prior to recent destructive earthquakes in Greece. We should bear in mind that whether electromagnetic precursors to earthquakes exist is an important question not only for earthquake prediction but mainly for understanding the physical processes of earthquake generation. An open question in this field of research is the classification of a detected electromagnetic anomaly as a pre-seismic signal associated with earthquake occurrence. Indeed, electromagnetic fluctuations in the frequency range of MHz are known to be related to a few sources, including atmospheric noise (due to lightning), man-made composite noise, solar-terrestrial noise (resulting from the Sun-solar wind-magnetosphere-ionosphere-Earth's surface chain) or cosmic noise, and finally, the lithospheric effect, namely pre-seismic activity. We focus on this point in this paper. We suggest that if a combination of detected kHz and MHz electromagnetic anomalies satisfies the set of criteria presented herein, these anomalies could be considered as candidate precursory phenomena of an impending earthquake.

Discrimination between preseismic electromagnetic anomalies and solar activity effects

NASA Astrophysics Data System (ADS)

Koulouras, Gr; Balasis, G.; Kontakos, K.; Ruzhin, Y.; Avgoustis, G.; Kavouras, D.; Nomicos, C.

2009-04-01

Laboratory studies suggest that electromagnetic emissions in a wide frequency spectrum ranging from kHz to very high MHz frequencies are produced by the opening of microcracks, with the MHz radiation appearing earlier than the kHz radiation. Earthquakes are large-scale fracture phenomena in the Earth's heterogeneous crust. Thus, the radiated kHz-MHz electromagnetic emissions are detectable not only at laboratory but also at geological scale. Clear MHz-to-kHz electromagnetic anomalies have been systematically detected over periods ranging from a few days to a few hours prior to recent destructive earthquakes in Greece. We bear in mind that whether electromagnetic precursors to earthquakes exist is an important question not only for earthquake prediction but mainly for understanding the physical processes of earthquake generation. An open question in this field of research is the classification of a detected electromagnetic anomaly as a pre-seismic signal associated to earthquake occurrence. Indeed, electromagnetic fluctuations in the frequency range of MHz are known to related to a few sources, i.e., they might be atmospheric noise (due to lightning), man-made composite noise, solar-terrestrial noise (resulting from the Sun-solar wind-magnetosphere-ionosphere-Earth's surface chain) or cosmic noise, and finally, lithospheric effect, namely pre-seismic activity. We focus on this point. We suggest that if a combination of detected kHz and MHz electromagnetic anomalies satisfies the herein presented set of criteria these anomalies could be considered as candidate precursory phenomena of an impending earthquake.

An improved DPSM technique for modelling ultrasonic fields in cracked solids

NASA Astrophysics Data System (ADS)

Banerjee, Sourav; Kundu, Tribikram; Placko, Dominique

2007-04-01

In recent years Distributed Point Source Method (DPSM) is being used for modelling various ultrasonic, electrostatic and electromagnetic field modelling problems. In conventional DPSM several point sources are placed near the transducer face, interface and anomaly boundaries. The ultrasonic or the electromagnetic field at any point is computed by superimposing the contributions of different layers of point sources strategically placed. The conventional DPSM modelling technique is modified in this paper so that the contributions of the point sources in the shadow region can be removed from the calculations. For this purpose the conventional point sources that radiate in all directions are replaced by Controlled Space Radiation (CSR) sources. CSR sources can take care of the shadow region problem to some extent. Complete removal of the shadow region problem can be achieved by introducing artificial interfaces. Numerically synthesized fields obtained by the conventional DPSM technique that does not give any special consideration to the point sources in the shadow region and the proposed modified technique that nullifies the contributions of the point sources in the shadow region are compared. One application of this research can be found in the improved modelling of the real time ultrasonic non-destructive evaluation experiments.

Joint Electromagnetic Spectrum Management Operations

DTIC Science & Technology

2012-03-20

electromagnetic radiation to ordnance ( HERO ), hazards of electromagnetic radiation to fuels (HERF), and natural phenomena effects of lightning and...fuels HERO hazards of electromagnetic radiation to ordnance HERP hazards of electromagnetic radiation to personnel HF high frequency HN host... electromagnetic pulse (EMP); hazards of EM radiation to personnel, ordnance ,

Gravity and Zero Point Energy

NASA Astrophysics Data System (ADS)

Massie, U. W.

When Planck introduced the 1/2 hv term to his 1911 black body equation he showed that there is a residual energy remaining at zero degree K after all thermal energy ceased. Other investigators, including Lamb, Casimir, and Dirac added to this information. Today zero point energy (ZPE) is accepted as an established condition. The purpose of this paper is to demonstrate that the density of the ZPE is given by the gravity constant (G) and the characteristics of its particles are revealed by the cosmic microwave background (CMB). Eddies of ZPE particles created by flow around mass bodies reduce the pressure normal to the eddy flow and are responsible for the force of gravity. Helium atoms resonate with ZPE particles at low temperature to produce superfluid helium. High velocity micro vortices of ZPE particles about a basic particle or particles are responsible for electromagnetic forces. The speed of light is the speed of the wave front in the ZPE and its value is a function of the temperature and density of the ZPE.

The Lagrange Points in a Binary Black Hole System: Applications to Electromagnetic Signatures

NASA Technical Reports Server (NTRS)

Schnittman, Jeremy

2010-01-01

We study the stability and evolution of the Lagrange points L_4 and L-5 in a black hole (BH) binary system, including gravitational radiation. We find that gas and stars can be shepherded in with the BH system until the final moments before merger, providing the fuel for a bright electromagnetic counterpart to a gravitational wave signal. Other astrophysical signatures include the ejection of hyper-velocity stars, gravitational collapse of globular clusters, and the periodic shift of narrow emission lines in AGN.

The localized quantum vacuum field

NASA Astrophysics Data System (ADS)

Dragoman, D.

2008-03-01

A model for the localized quantum vacuum is proposed in which the zero-point energy (ZPE) of the quantum electromagnetic field originates in energy- and momentum-conserving transitions of material systems from their ground state to an unstable state with negative energy. These transitions are accompanied by emissions and re-absorptions of real photons, which generate a localized quantum vacuum in the neighborhood of material systems. The model could help resolve the cosmological paradox associated with the ZPE of electromagnetic fields, while reclaiming quantum effects associated with quantum vacuum such as the Casimir effect and the Lamb shift. It also offers a new insight into the Zitterbewegung of material particles.

Features of the photometry of the superposition of coherent vector electromagnetic waves

NASA Astrophysics Data System (ADS)

Sakhnovskyj, Mykhajlo Yu.; Tymochko, Bogdan M.; Rudeichuk, Volodymyr M.

2018-01-01

In the paper we propose a general approach to the calculation of the forming the intensity and polarization fields of the superposition of arbitrary coherent vector beams at points of a given reference plane. The method of measuring photometric parameters of a field, formed in the neighborhood of an arbitrary point of the plane of analysis by minimizing the values of irradiance in the vicinity of a given point (method of zero-amplitude at a given point), which is achieved by superimposing on it the reference wave with the controlled values of intensity, polarization state, phase, and angle of incidence, is proposed.

Optics of tunneling from adiabatic nanotapers

NASA Astrophysics Data System (ADS)

Sumetsky, M.

2006-12-01

A theory of light propagation along adiabatic photonic nanowire tapers (nanotapers) having diameters significantly less than the radiation wavelength λ˜1 μm is developed. The fundamental mode of a nanotaper primarily consists of an evanescent field, which propagates in the ambient medium and is very sensitive to the nanotaper shape. General analytical expressions for the evanescent field and the radiation loss of adiabatic nanotapers are obtained and applied to the investigation of the optics of tunneling from a nanotaper of a characteristic shape. The radiation loss of this nanotaper occurs locally near a focal circumference of the evanescent field, representing an intersection of a complex caustic surface with real space, where the fundamental mode splits into the radiating and guiding components. The interference of these components gives rise to a sequence of circumferences with zero electromagnetic field.

Direct Reactions with Exotic Nuclei

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

Baur, G.; Typel, S.

2005-10-14

We discuss recent work on Coulomb dissociation and an effective-range theory of low-lying electromagnetic strength of halo nuclei. We propose to study Coulomb dissociation of a halo nucleus bound by a zero-range potential as a homework problem. We study the transition from stripping to bound and unbound states and point out in this context that the Trojan-Horse method is a suitable tool to investigate subthreshold resonances.

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.

[Biological effects of non-ionizing electromagnetic radiation].

PubMed

Fedorowski, A; Steciwko, A

1998-01-01

Since the mid 1970's, when Adey discovered that extremely-low-frequency electromagnetic field (ELF EMF) may affect the calcium ions efflux from various cells, bioeffects of non-ionizing radiation (NIR) have become the subject of growing interest and numerous research projects. At present, the fact that NIR exerts both stimulatory and inhibitory effects on different physiological cellular parameters is rather unquestionable. At the same time, some epidemiological studies suggest that exposure to EMF is potentially harmful even if its intensity is very low. It has been proved that thermal factors are not responsible for these effects, therefore nowadays, they are called 'non-thermal effects'. Our paper deals with three different aspects of biological effects of non-ionizing radiation, bioelectromagnetism, electromagnetobiology and electromagnetic bioinformation. Firstly, we describe how EMF and photons can be produced within a living cell, how biological cycles are controlled, and what are the features of endogenous electromagnetic radiation. Secondly, we discuss various facets of external EMF interactions with living matter, focusing on extremely-low-frequencies, radio- and microwaves. Possible mechanisms of these interactions are also mentioned. Finally, we present a short overview of current theories which explain how electromagnetic couplings may control an open and dissipative structure, namely the living organism. The theory of electromagnetic bioinformation seems to explain how different physiological processes are triggered and controlled, as well as how long-range interactions may possibly occur within the complex biological system. The review points out that the presented research data must be assessed very carefully since its evaluation is crucial to set the proper limits of EMF exposure, both occupational and environmental. The study of biological effects of non-ioinizing radiation may also contribute to the development of new diagnostic and therapeutic methods.

Topological magnetoelectric effects in microwave far-field radiation

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

Berezin, M.; Kamenetskii, E. O.; Shavit, R.

2016-07-21

Similar to electromagnetism, described by the Maxwell equations, the physics of magnetoelectric (ME) phenomena deals with the fundamental problem of the relationship between electric and magnetic fields. Despite a formal resemblance between the two notions, they concern effects of different natures. In general, ME-coupling effects manifest in numerous macroscopic phenomena in solids with space and time symmetry breakings. Recently, it was shown that the near fields in the proximity of a small ferrite particle with magnetic-dipolar-mode (MDM) oscillations have the space and time symmetry breakings and the topological properties of these fields are different from the topological properties of themore » free-space electromagnetic fields. Such MDM-originated fields—called magnetoelectric (ME) fields—carry both spin and orbital angular momenta. They are characterized by power-flow vortices and non-zero helicity. In this paper, we report on observation of the topological ME effects in far-field microwave radiation based on a small microwave antenna with a MDM ferrite resonator. We show that the microwave far-field radiation can be manifested with a torsion structure where an angle between the electric and magnetic field vectors varies. We discuss the question on observation of the regions of localized ME energy in far-field microwave radiation.« less

Manipulating the transmission through valve structure composed of zero-index metamaterial

NASA Astrophysics Data System (ADS)

Wang, Yongxing; Sun, Zhouzhou; Xu, Ping

2017-11-01

We propose a valve structure composed of zero-index metamaterial to manipulate the electromagnetic wave conveniently and effectively through regulating the phase of reflected waves. Both the structure and characteristics of zero-index metamaterial need not to be changed when manipulating the transmission, which maintains the stability of zero-index metamaterial. Moreover, the good performance of tuning the electromagnetic wave is not limited by the shape and size of our proposed structure. By using our proposed valve structure, we demonstrate the realization of the tunable curved anisotropic ɛ-near-zero material waveguide with irregular shape, arbitrarily sized isotropic ɛ-near-zero material waveguide with high transmittance and the curved isotropic impedance matched ɛ-near-zero material waveguide without polarization limitations.

Electromagnetic response of the protective pellicle of Euglenoids: influence of the surface profile

NASA Astrophysics Data System (ADS)

Inchaussandague, Marina E.; Gigli, Miriam L.; Skigin, Diana C.; Tolivia, Analía.; Conforti, Visitación

2015-03-01

In a recent paper we have investigated, from an electromagnetic point of view, the role played by the pellicle of Euglenoids -unicellular aquatic organisms- in the protection of the cell against UV radiation.14 By modelling the pellicle as a diffraction grating, we computed the electromagnetic response of different species that exhibit different behaviors against UV radiation. In this previous study, the pellicle profile was approximated by a sinusoidal grating. However, it has been observed in the transversal cut images that the profiles are not exactly sinusoidal, and also vary from sample to sample. Since the electromagnetic response depends on the geometry of the grating, reflectance calculations that take into account a more accurate representation of the actual profile could provide more insight into this problem. In this paper we investigate the electromagnetic response of the pellicle of Euglenoids for different grating profiles. The diffraction problem is solved by using the Chandezon method, which has demonstrated a successful performance for deep gratings of arbitrary profiles. We analyze the influence of the shape, depth and period of the grating on the UV reflectance. We show that the pellicle characteristics are critical parameters to increase the reflectance, thus reducing the penetration of the UV radiation within the cell and therefore, minimizing the damage and increasing the survival of these organisms.

Properties of an ultrarelativistic charged particle radiation in a constant homogeneous crossed electromagnetic field

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

Bogdanov, O.V., E-mail: bov@tpu.ru; Department of Higher Mathematics and Mathematical Physics, Tomsk Polytechnic University, Tomsk, 634050; Kazinski, P.O., E-mail: kpo@phys.tsu.ru

The properties of radiation created by a classical ultrarelativistic scalar charged particle in a constant homogeneous crossed electromagnetic field are described both analytically and numerically with radiation reaction taken into account in the form of the Landau–Lifshitz equation. The total radiation naturally falls into two parts: the radiation formed at the entrance point of a particle into the crossed field (the synchrotron entrance radiation), and the radiation coming from the late-time asymptotics of a particle motion (the de-excited radiation). The synchrotron entrance radiation resembles, although does not coincide with, the ultrarelativistic limit of the synchrotron radiation: its distribution over energiesmore » and angles possesses almost the same properties. The de-excited radiation is soft, not concentrated in the plane of motion of a charged particle, and almost completely circularly polarized. The photon energy delivering the maximum to its spectral angular distribution decreases with increasing the initial energy of a charged particle, while the maximum value of this distribution remains the same at the fixed photon observation angle and entrance angle of a charged particle. The ultraviolet and infrared asymptotics of the total radiation are also described. - Highlights: • Properties of an electron radiation in a crossed electromagnetic field are studied. • Spectral angular distribution of the synchrotron entrance radiation is described. • Spectral angular distribution of the de-excited radiation is described. • De-excited radiation is almost completely circularly polarized. • Photon energy at the maximum of the de-excited radiation decreases with increasing the initial energy of an electron.« less

Radiation from an Accelerated Point Charge and Non-Inertial Observers

ERIC Educational Resources Information Center

Leonov, A. B.

2012-01-01

It is known that observers comoving with a uniformly accelerated point charge detect the electromagnetic field of a charge as a static electric field. We show that one can find a similar family of observers, which detect the field of a charge as a static electric field, in the general case of arbitrary point-charge motion. We find the velocities…

A possible effect of electromagnetic radiation from mobile phone base stations on the number of breeding house sparrows (Passer domesticus).

PubMed

Everaert, Joris; Bauwens, Dirk

2007-01-01

A possible effect of long-term exposure to low-intensity electromagnetic radiation from mobile phone (GSM) base stations on the number of House Sparrows during the breeding season was studied in six residential districts in Belgium. We sampled 150 point locations within the 6 areas to examine small-scale geographic variation in the number of House Sparrow males and the strength of electromagnetic radiation from base stations. Spatial variation in the number of House Sparrow males was negatively and highly significantly related to the strength of electric fields from both the 900 and 1800 MHz downlink frequency bands and from the sum of these bands (Chi(2)-tests and AIC-criteria, P<0.001). This negative relationship was highly similar within each of the six study areas, despite differences among areas in both the number of birds and radiation levels. Thus, our data show that fewer House Sparrow males were seen at locations with relatively high electric field strength values of GSM base stations and therefore support the notion that long-term exposure to higher levels of radiation negatively affects the abundance or behavior of House Sparrows in the wild.

Tsallis entropy and decoherence of CsI quantum pseudo dot qubit

NASA Astrophysics Data System (ADS)

Tiotsop, M.; Fotue, A. J.; Fotsin, H. B.; Fai, L. C.

2017-05-01

Polaron in CsI quantum pseudo dot under an electromagnetic field was considered, and the ground and first excited state energies were derived by employing the combining Pekar variational and unitary transformation methods. With the two-level system obtained, single qubit was envisioned and the decoherence was studied using non-extensive entropy (Tsallis entropy). Numerical results showed: (i) the increase (decrease) of the energy levels (period of oscillation) with the increase of chemical potential, the zero point of pseudo dot, cyclotron frequency, and transverse and longitudinal confinements; (ii) the Tsallis entropy evolved as a wave envelop that increase with the increase of non-extenxive parameter and with the increase of electric field strength, zero point of pseudo dot and cyclotron frequency the wave envelop evolve periodically with reduction of period; (iii) The transition probability increases from the boundary to the centre of the dot where it has its maximum value. It was also noted that the probability density oscillate with period T0 = ℏ / Δ Ε with the tunnelling of the chemical potential and zero point of the pseudo dot. These results are helpful in the control of decoherence in quantum systems and may also be useful for the design of quantum computers.

The urban decline of the house sparrow (Passer domesticus): a possible link with electromagnetic radiation.

PubMed

Balmori, Alfonso; Hallberg, Orjan

2007-01-01

During recent decades, there has been a marked decline of the house sparrow (Passer domesticus) population in the United Kingdom and in several western European countries. The aims of this study were to determine whether the population is also declining in Spain and to evaluate the hypothesis that electromagnetic radiation (microwaves) from phone antennae is correlated with the decline in the sparrow population. Between October 2002 and May 2006, point transect sampling was performed at 30 points during 40 visits to Valladolid, Spain. At each point, we carried out counts of sparrows and measured the mean electric field strength (radiofrequencies and microwaves: 1 MHz-3 GHz range). Significant declines (P = 0.0037) were observed in the mean bird density over time, and significantly low bird density was observed in areas with high electric field strength. The logarithmic regression of the mean bird density vs. field strength groups (considering field strength in 0.1 V/m increments) was R = -0.87 (P = 0.0001). The results of this article support the hypothesis that electromagnetic signals are associated with the observed decline in the sparrow population. We conclude that electromagnetic pollution may be responsible, either by itself or in combination with other factors, for the observed decline of the species in European cities during recent years. The appearently strong dependence between bird density and field strength according to this work could be used for a more controlled study to test the hypothesis.

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.

Prostate tumor alignment and continuous, real-time adaptive radiation therapy using electromagnetic fiducials: clinical and cost-utility analyses.

PubMed

Quigley, Martin M; Mate, Timothy P; Sylvester, John E

2009-01-01

To evaluate the accuracy, utility, and cost effectiveness of a new electromagnetic patient positioning and continuous, real-time monitoring system, which uses permanently implanted resonant transponders in the target (Calypso 4D Localization System and Beacon transponders, Seattle, WA) to continuously monitor tumor location and movement during external beam radiation therapy of the prostate. This clinical trial studied 43 patients at 5 sites. All patients were implanted with 3 transponders each. In 41 patients, the system was used for initial alignment at each therapy session. Thirty-five patients had continuous monitoring during their radiation treatment. Over 1,000 alignment comparisons were made to a commercially available kV X-ray positioning system (BrainLAB ExacTrac, Munich, Germany). Using decision analysis and Markov processes, the outcomes of patients were simulated over a 5-year period and measured in terms of costs from a payer's perspective and quality-adjusted life years (QALYs). All patients had satisfactory transponder implantations for monitoring purposes. In over 75% of the treatment sessions, the correction to conventional positioning (laser and tattoos) directed by an electromagnetic patient positioning and monitoring system was greater than 5 mm. Ninety-seven percent (34/35) of the patients who underwent continuous monitoring had target motion that exceeded preset limits at some point during the course of their radiation therapy. Exceeding preset thresholds resulted in user intervention at least once during the therapy in 80% of the patients (28/35). Compared with localization using ultrasound, electronic portal imaging devices (EPID), or computed tomography (CT), localization with the electromagnetic patient positioning and monitoring system yielded superior gains in QALYs at comparable costs. Most patients positioned with conventional tattoos and lasers for prostate radiation therapy were found by use of the electromagnetic patient positioning and monitoring system to have alignment errors exceeding 5 mm. Almost all patients undergoing external beam radiation of the prostate have been shown to have target organ movement exceeding 3 mm during radiation therapy delivery. The ability of the electromagnetic technology to monitor tumor target location during the same time as radiation therapy is being delivered allows clinicians to provide real time adaptive radiation therapy for prostate cancer. This permits clinicians to intervene when the prostate moves outside the radiation isocenter, which should decrease adverse events and improve patient outcomes. Additionally, a cost-utility analysis has demonstrated that the electromagnetic patient positioning and monitoring system offers patient outcome benefits at a cost that falls well within the payer's customary willingness to pay (WTP) threshold of $50,000 per QALY.

Radiation of a charge flying in a partially loaded dielectric section of a waveguide

NASA Astrophysics Data System (ADS)

Grigoreva, Aleksandra A.; Tyukhtin, Andrey V.; Vorobev, Viktor V.; Galyamin, Sergey N.; Antipov, Sergey

2018-03-01

We consider the electromagnetic field of a point charged particle moving along the axis of a cylindrical waveguide from a homogeneously filled area to a dielectric loading area having an axially symmetrical channel. We are interested in studying the Cherenkov radiation excited in the bilayer area. The solution is performed by expanding the field in each area in a series of orthogonal eigenmodes. The main attention is focused on investigation of the wave field in the bilayer section. We show that, at a given observation point, the "reduced wakefield" is simplified with time (the number of modes decreases). The obtained results are generalized for the case of a bunch with Gaussian longitudinal profile. The typical numerical results for wakefield formation process are presented. These results agree with simulations done by the industry standard electromagnetic code CST Particle Studio.

Integration and Validation of Avian Radars (IVAR)

DTIC Science & Technology

2011-08-01

hazards of electromagnetic radiation to fuel HERO hazards of electromagnetic radiation to ordnance HERP hazards ... hazard Radiation hazard to humans, fuels, and ordnance can be easily managed. Demonstration of how operation of radars can meet hazards of... electromagnetic radiation to personnel (HERP), hazards of electromagnetic radiation to

21 CFR 1000.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-04-01

... person is or has been primarily or customarily engaged in such business. (i) Electromagnetic radiation includes the entire electromagnetic spectrum of radiation of any wavelength. The electromagnetic spectrum...) Electronic product radiation means: (1) Any ionizing or nonionizing electromagnetic or particulate radiation...

21 CFR 1000.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-04-01

... person is or has been primarily or customarily engaged in such business. (i) Electromagnetic radiation includes the entire electromagnetic spectrum of radiation of any wavelength. The electromagnetic spectrum...) Electronic product radiation means: (1) Any ionizing or nonionizing electromagnetic or particulate radiation...

21 CFR 1000.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-04-01

... person is or has been primarily or customarily engaged in such business. (i) Electromagnetic radiation includes the entire electromagnetic spectrum of radiation of any wavelength. The electromagnetic spectrum...) Electronic product radiation means: (1) Any ionizing or nonionizing electromagnetic or particulate radiation...

21 CFR 1000.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-04-01

... person is or has been primarily or customarily engaged in such business. (i) Electromagnetic radiation includes the entire electromagnetic spectrum of radiation of any wavelength. The electromagnetic spectrum...) Electronic product radiation means: (1) Any ionizing or nonionizing electromagnetic or particulate radiation...

21 CFR 1000.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-04-01

... person is or has been primarily or customarily engaged in such business. (i) Electromagnetic radiation includes the entire electromagnetic spectrum of radiation of any wavelength. The electromagnetic spectrum...) Electronic product radiation means: (1) Any ionizing or nonionizing electromagnetic or particulate radiation...

Response of two-phase droplets to intense electromagnetic radiation

NASA Technical Reports Server (NTRS)

Spann, James F.; Maloney, Daniel J.; Lawson, William F.; Casleton, Kent H.

1993-01-01

The behavior of two-phase droplets subjected to high intensity radiation pulses is studied. Droplets are highly absorbing solids in weakly absorbing liquid medium. The objective of the study was to define heating thresholds required for causing explosive boiling and secondary atomization of the fuel droplet. The results point to mechanisms for energy storage and transport in two-phase systems.

[Indirect and repeated electromagnetic irradiation of extremely high freguency of bacteria Escherichia coli].

PubMed

Isakhanian, V; Trchunian, A

2005-01-01

It has been shown that separate irradiation of distilled water and tris-phosphate buffer containing some inorganic ions, with Escherichia coli K12 grown in anaerobic conditions upon fermentation of sugar (glucose) with "noise" electromagnetic radiation of extremely high frequencies (53.5-68 gHz) or millimeter waves (wavelength of 3 to 8 mm) with low flux capacity (0.01 mW) for 10, 30 and 60 min caused opposite effects, changing the growth of these bacteria. The irradiation of water has a bactericide effect, whereas the irradiation of the buffer stimulates bacterial growth although the buffer itself inhibits the growth. These results point out the role of water in the bactericide action of "noise" electromagnetic radiation of extremely high frequencies, and confirm the significance of membranotropic effects. The bactericide action disappeared after repeated irradiation for 10 and 30 min with 2-h intervals. This indicates the operation of some compensatory mechanisms in bacteria.

Zero frequency modes of the Maclaurin spheroids

NASA Astrophysics Data System (ADS)

Baumgart, D.; Friedman, J. L.

1986-05-01

The location of all zero-frequency modes of oscillation along the Maclaurin sequence are found for modes corresponding to oblate spheroidal harmonics with indices (l,m) where l less than 6 (equivalently, for modes described by Lagrangian displacements whose components in Cartesian coordinates are polynomials of degree less than or equal to 5). These points of zero frequency mark the onset of instability in each mode in the context of general relativity, or when a gravitational radiation reaction term is adjointed to the Newtonian theory.

Measurement and analysis of electromagnetic pollution generated by GSM-900 mobile phone networks in Erciyes University, Turkey.

PubMed

Sorgucu, Ugur; Develi, Ibrahim

2012-12-01

Mobile phones are becoming increasingly important in our everyday lives. The rising number of mobile phones reflects a similar increase in the number of base stations. Because of this rapid evolution, the establishment and planning of new base stations has become mandatory. However, the rise in the number of base stations, in terms of human health, is potentially very harmful. It is important to analyze the radiation levels of base stations until we can confirm that they are definitely not harmful in the long term. Mapping of electromagnetic field (EMF) is also important from a medical point of view because it provides useful information, for example, on the detection of diseases caused by EMF. With the help of this information the distribution of diseases over different regions can be obtained. In this article, the electromagnetic radiation levels of base stations were measured at 80 different points in Erciyes University (ERU), Turkey and detailed information about the measurement tools and measurement method were given. It was observed that no area in ERU exceeded the national and international limits. It is also observed that the effects of base stations vary according to duration and degree of exposure. Therefore, if people are exposed to a very low-intensity electromagnetic field for a very long time, serious health problems can occur.

Background compensation for a radiation level monitor

DOEpatents

Keefe, D.J.

1975-12-01

Background compensation in a device such as a hand and foot monitor is provided by digital means using a scaler. With no radiation level test initiated, a scaler is down-counted from zero according to the background measured. With a radiation level test initiated, the scaler is up-counted from the previous down-count position according to the radiation emitted from the monitored object and an alarm is generated if, with the scaler having crossed zero in the positive going direction, a particular number is exceeded in a specific time period after initiation of the test. If the test is initiated while the scale is down-counting, the background count from the previous down- count stored in a memory is used as the initial starting point for the up-count.

[Influence of electromagnetic radiation on toxicity of Vipera lebetina obtusa venom].

PubMed

Abiev, G A; Babaev, E I; Topchieva, Sh A; Chumburidze, T B; Nemsitsveridze, N G

2009-11-01

The aim of the article was to study the effect of electromagnetic radiation on toxicity of Vipera lebetina obtusa venom. It was found that mice intoxicated with snake venom, with moderate to high exposure to electromagnetic radiation and mice intoxicated with venom, which had not been exposed to the radiation showed the same symptoms of intoxication and death. At the same time, the longevity of mice intoxicated with venom exposed to electromagnetic radiation was higher. The longevity of mice in control group was 25+/-5 min. The longevity of mice intoxicated with exposed to electromagnetic radiation snake venom was from 29 to 60 min. The research showed that the longevity of mice intoxicated with snake venom rose with the level of electromagnetic radiation intensity the snake was exposed to. Accordingly, snake venom, with exposure to high intensity electromagnetic radiation is less toxic.

Hazards of Electromagnetic Radiation to Ordnance (HERO) Safety Test

DTIC Science & Technology

2013-01-10

Ordnance Test Procedure (JOTP)-061 Hazards of Electromagnetic Radiation to...DEPARTMENT OF DEFENSE JOINT ORDNANCE TEST PROCEDURE (JOTP)-061 HAZARDS OF ELECTROMAGNETIC RADIATION TO ORDNANCE (HERO) SAFETY...TEST Joint Services Munition Safety Test Working Group Joint Ordnance Test Procedure (JOTP)-061 Hazards of Electromagnetic Radiation

Quantum principle of sensing gravitational waves: From the zero-point fluctuations to the cosmological stochastic background of spacetime

NASA Astrophysics Data System (ADS)

Quiñones, Diego A.; Oniga, Teodora; Varcoe, Benjamin T. H.; Wang, Charles H.-T.

2017-08-01

We carry out a theoretical investigation on the collective dynamics of an ensemble of correlated atoms, subject to both vacuum fluctuations of spacetime and stochastic gravitational waves. A general approach is taken with the derivation of a quantum master equation capable of describing arbitrary confined nonrelativistic matter systems in an open quantum gravitational environment. It enables us to relate the spectral function for gravitational waves and the distribution function for quantum gravitational fluctuations and to indeed introduce a new spectral function for the zero-point fluctuations of spacetime. The formulation is applied to two-level identical bosonic atoms in an off-resonant high-Q cavity that effectively inhibits undesirable electromagnetic delays, leading to a gravitational transition mechanism through certain quadrupole moment operators. The overall relaxation rate before reaching equilibrium is found to generally scale collectively with the number N of atoms. However, we are also able to identify certain states of which the decay and excitation rates with stochastic gravitational waves and vacuum spacetime fluctuations amplify more significantly with a factor of N2. Using such favorable states as a means of measuring both conventional stochastic gravitational waves and novel zero-point spacetime fluctuations, we determine the theoretical lower bounds for the respective spectral functions. Finally, we discuss the implications of our findings on future observations of gravitational waves of a wider spectral window than currently accessible. Especially, the possible sensing of the zero-point fluctuations of spacetime could provide an opportunity to generate initial evidence and further guidance of quantum gravity.

Electromagnetic scattering by a uniaxial anisotropic sphere located in an off-axis Bessel beam.

PubMed

Qu, Tan; Wu, Zhen-Sen; Shang, Qing-Chao; Li, Zheng-Jun; Bai, Lu

2013-08-01

Electromagnetic scattering of a zero-order Bessel beam by an anisotropic spherical particle in the off-axis configuration is investigated. Based on the spherical vector wave functions, the expansion expression of the zero-order Bessel beam is derived, and its convergence is numerically discussed in detail. Utilizing the tangential continuity of the electromagnetic fields, the expressions of scattering coefficients are given. The effects of the conical angle of the wave vector components of the zero-order Bessel beam, the ratio of the radius of the sphere to the central spot radius of the zero-order Bessel beam, the shift of the beam waist center position along both the x and y axes, the permittivity and permeability tensor elements, and the loss of the sphere on the radar cross section (RCS) are numerically analyzed. It is revealed that the maximum RCS appears in the conical direction or neighboring direction when the sphere is illuminated by a zero-order Bessel beam. Furthermore, the RCS will decrease and the symmetry is broken with the shift of the beam waist center.

Knotted optical vortices in exact solutions to Maxwell's equations

NASA Astrophysics Data System (ADS)

de Klerk, Albertus J. J. M.; van der Veen, Roland I.; Dalhuisen, Jan Willem; Bouwmeester, Dirk

2017-05-01

We construct a family of exact solutions to Maxwell's equations in which the points of zero intensity form knotted lines topologically equivalent to a given but arbitrary algebraic link. These lines of zero intensity, more commonly referred to as optical vortices, and their topology are preserved as time evolves and the fields have finite energy. To derive explicit expressions for these new electromagnetic fields that satisfy the nullness property, we make use of the Bateman variables for the Hopf field as well as complex polynomials in two variables whose zero sets give rise to algebraic links. The class of algebraic links includes not only all torus knots and links thereof, but also more intricate cable knots. While the unknot has been considered before, the solutions presented here show that more general knotted structures can also arise as optical vortices in exact solutions to Maxwell's equations.

Feasibility study of a synthesis procedure for array feeds to improve radiation performance of large distorted reflector antennas

NASA Technical Reports Server (NTRS)

Stutzman, W. L.; Smith, W. T.

1990-01-01

Surface errors on parabolic reflector antennas degrade the overall performance of the antenna. Space antenna structures are difficult to build, deploy and control. They must maintain a nearly perfect parabolic shape in a harsh environment and must be lightweight. Electromagnetic compensation for surface errors in large space reflector antennas can be used to supplement mechanical compensation. Electromagnetic compensation for surface errors in large space reflector antennas has been the topic of several research studies. Most of these studies try to correct the focal plane fields of the reflector near the focal point and, hence, compensate for the distortions over the whole radiation pattern. An alternative approach to electromagnetic compensation is presented. The proposed technique uses pattern synthesis to compensate for the surface errors. The pattern synthesis approach uses a localized algorithm in which pattern corrections are directed specifically towards portions of the pattern requiring improvement. The pattern synthesis technique does not require knowledge of the reflector surface. It uses radiation pattern data to perform the compensation.

Pitch-angle diffusion of electrons through growing and propagating along a magnetic field electromagnetic wave in Earth's radiation belts

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

Choi, C.-R., E-mail: crchoi@kaist.ac.kr; Dokgo, K.; Min, K.-W.

The diffusion of electrons via a linearly polarized, growing electromagnetic (EM) wave propagating along a uniform magnetic field is investigated. The diffusion of electrons that interact with the growing EM wave is investigated through the autocorrelation function of the parallel electron acceleration in several tens of electron gyration timescales, which is a relatively short time compared with the bounce time of electrons between two mirror points in Earth's radiation belts. Furthermore, the pitch-angle diffusion coefficient is derived for the resonant and non-resonant electrons, and the effect of the wave growth on the electron diffusion is discussed. The results can bemore » applied to other problems related to local acceleration or the heating of electrons in space plasmas, such as in the radiation belts.« less

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.

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

Thin-film spectroscopic sensor

DOEpatents

Burgess, Jr., Lloyd W.; Goldman, Don S.

1992-01-01

There is disclosed an integrated spectrometer for chemical analysis by evanescent electromagnetic radiation absorption in a reaction volume. The spectrometer comprises a noninteractive waveguide, a substrate, an entrance grating and an exit grating, an electromagnetic radiation source, and an electromagnetic radiation sensing device. There is further disclosed a chemical sensor to determine the pressure and concentration of a chemical species in a mixture comprising an interactive waveguide, a substrate, an entrance grating and an exit grating, an electromagnetic radiation source, and an electromagnetic radiation sensing device.

Dynamical Casimir effect in a Josephson metamaterial

PubMed Central

Lähteenmäki, Pasi; Paraoanu, G. S.; Hassel, Juha; Hakonen, Pertti J.

2013-01-01

The zero-point energy stored in the modes of an electromagnetic cavity has experimentally detectable effects, giving rise to an attractive interaction between the opposite walls, the static Casimir effect. A dynamical version of this effect was predicted to occur when the vacuum energy is changed either by moving the walls of the cavity or by changing the index of refraction, resulting in the conversion of vacuum fluctuations into real photons. Here, we demonstrate the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity at 5.4 GHz. We modulate the effective length of the cavity by flux-biasing the metamaterial based on superconducting quantum interference devices (SQUIDs), which results in variation of a few percentage points in the speed of light. We extract the full 4 × 4 covariance matrix of the emitted microwave radiation, demonstrating that photons at frequencies symmetrical with respect to half of the modulation frequency are generated in pairs. At large detunings of the cavity from half of the modulation frequency, we find power spectra that clearly show the theoretically predicted hallmark of the Casimir effect: a bimodal, “sparrow-tail” structure. The observed substantial photon flux cannot be assigned to parametric amplification of thermal fluctuations; its creation is a direct consequence of the noncommutativity structure of quantum field theory.

Synchronization behaviors of coupled neurons under electromagnetic radiation

NASA Astrophysics Data System (ADS)

Ma, Jun; Wu, Fuqiang; Wang, Chunni

2017-01-01

Based on an improved neuronal model, in which the effect of magnetic flux is considered during the fluctuation and change of ion concentration in cells, the transition of synchronization is investigated by imposing external electromagnetic radiation on the coupled neurons, and networks, respectively. It is found that the synchronization degree depends on the coupling intensity and the intensity of external electromagnetic radiation. Indeed, appropriate intensity of electromagnetic radiation could be effective to realize intermittent synchronization, while stronger intensity of electromagnetic radiation can induce disorder of coupled neurons and network. Neurons show rhythm synchronization in the electrical activities by increasing the coupling intensity under electromagnetic radiation, and spatial patterns can be formed in the network under smaller factor of synchronization.

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

FDTD-based computed terahertz wave propagation in multilayer medium structures

NASA Astrophysics Data System (ADS)

Tu, Wan-li; Zhong, Shun-cong; Yao, Hai-zi; Shen, Yao-chun

2013-08-01

The terahertz region of the electromagnetic spectrum spans the frequency range of 0.1THz~10THz, which means it sandwiches between the mid-infrared (IR) and the millimeter/ microwave. With the development and commercialization of terahertz pulsed spectroscopy (TPS) and terahertz pulsed imaging (TPI) systems, terahertz technologies have been widely used in the sensing and imaging fields. It allows high quality cross-sectional images from within scattering media to be obtained nondestructively. Characterizing the interaction of terahertz radiation with multilayer medium structures is critical for the development of nondestructive testing technology. Currently, there was much experimental investigation of using TPI for the characterization of terahertz radiation in materials (e.g., pharmaceutical tablet coatings), but there were few theoretical researches on propagation of terahertz radiation in multilayer medium structures. Finite Difference Time Domain (FDTD) algorithm is a proven method for electromagnetic scattering theory, which analyzes continuous electromagnetic problems by employing finite difference and obtains electromagnetic field value at the sampling point to approach the actual continuous solutions. In the present work, we investigated the propagation of terahertz radiation in multilayer medium structures based on FDTD method. The model of multilayer medium structures under the THz frequency plane wave incidence was established, and the reflected radiation properties were recorded and analyzed. The terahertz radiation used was broad-band in the frequency up to 2 THz. A batch of single layer coated pharmaceutical tablets, whose coating thickness in the range of 40~100μm, was computed by FDTD method. We found that the simulation results on pharmaceutical tablet coatings were in good agreement with the experimental results obtained using a commercial system (TPI imaga 2000, TeraView, Cambridge, UK) , demonstrating its usefulness in simulating and analyzing terahertz responses from a multilayered sample.

A computer program to evaluate optical systems

NASA Technical Reports Server (NTRS)

Innes, D.

1972-01-01

A computer program is used to evaluate a 25.4 cm X-ray telescope at a field angle of 20 minutes of arc by geometrical analysis. The object is regarded as a point source of electromagnetic radiation, and the optical surfaces are treated as boundary conditions in the solution of the electromagnetic wave propagation equation. The electric field distribution is then determined in the region of the image and the intensity distribution inferred. A comparison of wave analysis results and photographs taken through the telescope shows excellent agreement.

21 CFR 1000.15 - Examples of electronic products subject to the Radiation Control for Health and Safety Act of 1968.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... (a) Examples of electronic products which may emit x-rays and other ionizing electromagnetic radiation, electrons, neutrons, and other particulate radiation include: Ionizing electromagnetic radiation... radiation and ionizing electromagnetic radiation: Electron microscopes. Neutron generators. (b) Examples of...

21 CFR 1000.15 - Examples of electronic products subject to the Radiation Control for Health and Safety Act of 1968.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... (a) Examples of electronic products which may emit x-rays and other ionizing electromagnetic radiation, electrons, neutrons, and other particulate radiation include: Ionizing electromagnetic radiation... radiation and ionizing electromagnetic radiation: Electron microscopes. Neutron generators. (b) Examples of...

21 CFR 1000.15 - Examples of electronic products subject to the Radiation Control for Health and Safety Act of 1968.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... (a) Examples of electronic products which may emit x-rays and other ionizing electromagnetic radiation, electrons, neutrons, and other particulate radiation include: Ionizing electromagnetic radiation... radiation and ionizing electromagnetic radiation: Electron microscopes. Neutron generators. (b) Examples of...

21 CFR 1000.15 - Examples of electronic products subject to the Radiation Control for Health and Safety Act of 1968.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... (a) Examples of electronic products which may emit x-rays and other ionizing electromagnetic radiation, electrons, neutrons, and other particulate radiation include: Ionizing electromagnetic radiation... radiation and ionizing electromagnetic radiation: Electron microscopes. Neutron generators. (b) Examples of...

21 CFR 1000.15 - Examples of electronic products subject to the Radiation Control for Health and Safety Act of 1968.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... (a) Examples of electronic products which may emit x-rays and other ionizing electromagnetic radiation, electrons, neutrons, and other particulate radiation include: Ionizing electromagnetic radiation... radiation and ionizing electromagnetic radiation: Electron microscopes. Neutron generators. (b) Examples of...

Electromagnetic field radiation model for lightning strokes to tall structures

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

Motoyama, H.; Janischewskyj, W.; Hussein, A.M.

1996-07-01

This paper describes observation and analysis of electromagnetic field radiation from lightning strokes to tall structures. Electromagnetic field waveforms and current waveforms of lightning strokes to the CN Tower have been simultaneously measured since 1991. A new calculation model of electromagnetic field radiation is proposed. The proposed model consists of the lightning current propagation and distribution model and the electromagnetic field radiation model. Electromagnetic fields calculated by the proposed model, based on the observed lightning current at the CN Tower, agree well with the observed fields at 2km north of the tower.

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.

Effect of electromagnetic radiations on neurodegenerative diseases- technological revolution as a curse in disguise.

PubMed

Hasan, Gulam M; Sheikh, Ishfaq A; Karim, Sajjad; Haque, Absarul; Kamal, Mohammad A; Chaudhary, Adeel G; Azhar, Essam; Mirza, Zeenat

2014-01-01

In the present developed world, all of us are flooded with electromagnetic radiations (EMR) emanating from generation and transmission of electricity, domestic appliances and industrial equipments, to telecommunications and broadcasting. We have been exposed to EMR for last many decades; however their recent steady increase from artificial sources has been reported as millions of antennas and satellites irradiate the global population round the clock, year round. Needless to say, these are so integral to modern life that interaction with them on a daily basis is seemingly inevitable; hence, the EMR exposure load has increased to a point where their health effects are becoming a major concern. Delicate and sensitive electrical system of human body is affected by consistent penetration of electromagnetic frequencies causing DNA breakages and chromosomal aberrations. Technological innovations came with Pandora's Box of hazardous consequences including neurodegenerative disorders, hearing disabilities, diabetes, congenital abnormalities, infertility, cardiovascular diseases and cancer to name few, all on a sharp rise. Electromagnetic non-ionizing radiations pose considerable health threat with prolonged exposure. Mobile phones are usually held near to the brain and manifest progressive structural or functional alterations in neurons leading to neurodegenerative diseases and neuronal death. This has provoked awareness among both the general public and scientific community and international bodies acknowledge that further systematic research is needed. The aim of the present review was to have an insight in whether and how cumulative electro-magnetic field exposure is a risk factor for neurodegenerative disorders.

Robinson-Trautman solutions to Einstein's equations

NASA Astrophysics Data System (ADS)

Davidson, William

2017-02-01

Solutions to Einstein's equations in the form of a Robinson-Trautman metric are presented. In particular, we derive a pure radiation solution which is non-stationary and involves a mass m, The resulting spacetime is of Petrov Type II A special selection of parametric values throws up the feature of the particle `rocket', a Type D metric. A suitable transformation of the complex coordinates allows the metrics to be expressed in real form. A modification, by setting m to zero, of the Type II metric thereby converting it to Type III, is then shown to admit a null Einstein-Maxwell electromagnetic field.

Laser beat wave excitation of terahertz radiation in a plasma slab

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

Chauhan, Santosh; Parashar, Jetendra, E-mail: j.p.parashar@gmail.com

2014-10-15

Terahertz (THz) radiation generation by nonlinear mixing of lasers, obliquely incident on a plasma slab is investigated. Two cases are considered: (i) electron density profile is parabolic but density peak is below the critical density corresponding to the beat frequency, (ii) plasma boundaries are sharp and density is uniform. In both cases, nonlinearity arises through the ponderomotive force that gives rise to electron drift at the beat frequency. In the case of inhomogeneous plasma, non zero curl of the nonlinear current density gives rise to electromagnetic THz generation. In case of uniform plasma, the sharp density variation at the plasmamore » boundaries leads to radiation generation. In a slab width of less than a terahertz wavelength, plasma density one fourth of terahertz critical density, laser intensities ∼10{sup 17 }W/cm{sup 2} at 1 μm, one obtains the THz intensity ∼1 GW/cm{sup 2} at 3 THz radiation frequency.« less

QUANTUM MECHANICS. Quantum squeezing of motion in a mechanical resonator.

PubMed

Wollman, E E; Lei, C U; Weinstein, A J; Suh, J; Kronwald, A; Marquardt, F; Clerk, A A; Schwab, K C

2015-08-28

According to quantum mechanics, a harmonic oscillator can never be completely at rest. Even in the ground state, its position will always have fluctuations, called the zero-point motion. Although the zero-point fluctuations are unavoidable, they can be manipulated. Using microwave frequency radiation pressure, we have manipulated the thermal fluctuations of a micrometer-scale mechanical resonator to produce a stationary quadrature-squeezed state with a minimum variance of 0.80 times that of the ground state. We also performed phase-sensitive, back-action evading measurements of a thermal state squeezed to 1.09 times the zero-point level. Our results are relevant to the quantum engineering of states of matter at large length scales, the study of decoherence of large quantum systems, and for the realization of ultrasensitive sensing of force and motion. Copyright © 2015, American Association for the Advancement of Science.

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.

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.

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

Anisotropic conducting films for electromagnetic radiation applications

DOEpatents

Cavallo, Francesca; Lagally, Max G.; Rojas-Delgado, Richard

2015-06-16

Electronic devices for the generation of electromagnetic radiation are provided. Also provided are methods for using the devices to generate electromagnetic radiation. The radiation sources include an anisotropic electrically conducting thin film that is characterized by a periodically varying charge carrier mobility in the plane of the film. The periodic variation in carrier mobility gives rise to a spatially varying electric field, which produces electromagnetic radiation as charged particles pass through the film.

Electromagnetic response of the protective pellicle of different unicellular microalgae

NASA Astrophysics Data System (ADS)

Inchaussandague, Marina E.; Skigin, Diana C.; Tolivia, Analía.; Fuertes Vila, Isabel; Conforti, Visitación

2014-03-01

Euglenoids are unicellular aquatic organisms. These microalgae show a typical surface structure that distinguishes them from the other protists. Most cells are naked and bounded by a plasma membrane surrounded by a pellicle formed by overlapping bands. It is well known that all terrestrial and aquatic organisms are exposed to UV-A and UV-B radiation. This radiation is potentially harmful to life and since it can penetrate up to 12 meters in the water, it can reduce survival, growth and production of phytoplankton. However, the organisms have developed numerous protection mechanisms intended to reduce such damage, such as the production of pigments and other repair mechanisms. However, the possible protection that could provide the first barriers before entering into the cell has not been explored yet. In this paper we investigate, from an electromagnetic point of view, the role played by the pellicle of euglenoids in the protection of the cell against UV radiation. To do so, we investigate the electromagnetic response of different species that exhibit different behaviors against the UV radiation. We solve the diffraction problem by using the Chandezon Method and obtain the reflectance of the pellicle for the UV wavelengths. The results show that the corrugated pellicle could contribute to increase the reflectance, thus reducing the penetration of the UV radiation within the cell and therefore, minimizing the damage and increasing the survival of these organisms.

Stabilization of beam-weibel instability by equilibrium density ripples

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

Mishra, S. K., E-mail: nishfeb@gmail.com; Kaw, Predhiman; Das, A.

In this paper, we present an approach to achieve suppression/complete stabilization of the transverse electromagnetic beam Weibel instability in counter streaming electron beams by modifying the background plasma with an equilibrium density ripple, shorter than the skin depth; this weakening is more pronounced when thermal effects are included. On the basis of a linear two stream fluid model, it is shown that the growth rate of transverse electromagnetic instabilities can be reduced to zero value provided certain threshold values for ripple parameters are exceeded. We point out the relevance of the work to recent experimental investigations on sustained (long length)more » collimation of fast electron beams and integral beam transport for laser induced fast ignition schemes, where beam divergence is suppressed with the assistance of carbon nano-tubes.« less

New Precision Limit on the Strange Vector Form Factors of the Proton

DOE PAGES

Ahmed, Z.; Allada, K.; Aniol, K. A.; ...

2012-03-01

The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q 2 = 0.624 GeV 2 and beam energy E b = 3.48 GeV to be A PV = -23.80 ± 0.78 (stat) ± 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G E s + 0.517 G M s = 0.003 ± 0.010 (stat) ± 0.004 (syst) ± 0.009 (ff), where the third error is due to the limits of precisionmore » on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.« less

Electromagnetic Spectrum Test and Evaluation Process

DTIC Science & Technology

2010-01-01

HERO , hazards of electromagnetic radiation to ordnance ; HERP, hazards of electromagnetic radiation to personnel; HERF, hazards of electromagnetic ... electromagnetic pulse (EMP); electronic protection; electrostatic dis- charge (ESD); hazards of electromagnetic radi- ation to personnel (HERP), ordnance ...including ordnance containing electrically initiated devices, to be mutually compatible in their intended

Spectrum Management and Electromagnetic Environmental Effects (E3) Business Process

DTIC Science & Technology

2010-05-06

HAZARDS OF ELECTROMAGNETIC RADIATION TO ORDNANCE ( HERO ) SURVEY. XM11: IS THERE A CURRENT ELECTROMAGNETIC INTERFERENCE (EMI) SITE SURVEY. SM & EMI Navy...PERSONNEL (HERP) / FUEL (HERF) SURVEY. XM10: IS THERE A CURRENT HAZARDS OF ELECTROMAGNETIC RADIATION TO ORDNANCE ( HERO ) SURVEY. XM11...OF ALL KNOWN ELECTROMAGNETIC INTERFERENCE (EMI) FIXES INSTALLED ONE YEAR AFTER SURVEY COMPLETION. M05: OF ALL RADIATION HAZARDS

Mesoscopic structure formation in condensed matter due to vacuum fluctuations

NASA Astrophysics Data System (ADS)

Sen, Siddhartha; Gupta, Kumar S.; Coey, J. M. D.

2015-10-01

An observable influence of zero-point fluctuations of the vacuum electromagnetic field on bound electrons is well known in the hydrogen atom, where it produces the Lamb shift. Here, we adapt an approach used to explain the Lamb shift in terms of a slight expansion of the orbits due to interaction with the zero-point field and apply it to assemblies of N electrons that are modeled as independent atomically bound two-level systems. The effect is to stabilize a collective ground-state energy, which leads to a prediction of novel effects at room temperature for quasi-two-dimensional systems over a range of parameters in the model, namely, N , the two-level excitation energy ℏ ω and the ionization energy ℏ ω +ɛ . Some mesoscopic systems where these effects may be observable include water sheaths on protein or DNA, surfaces of gaseous nanobubbles, and the magnetic response of inhomogeneous, electronically dilute oxides. No such effects are envisaged for uniform three-dimensional systems.

The Zero-Point Field and the NASA Challenge to Create the Space Drive

NASA Technical Reports Server (NTRS)

Haisch, Bernhard; Rueda, Alfonso

1999-01-01

This NASA Breakthrough Propulsion Physics Workshop seeks to explore concepts that could someday enable interstellar travel. The effective superluminal motion proposed by Alcubierre (1994) to be a possibility owing to theoretically allowed space-time metric distortions within general relativity has since been shown by Pfenning and Ford (1997) to be physically unattainable. A number of other hypothetical possibilities have been summarized by Millis (1997). We present herein an overview of a concept that has implications for radically new propulsion possibilities and has a basis in theoretical physics: the hypothesis that the inertia and gravitation of matter originate in electromagnetic interactions between the zero-point field (ZPF) and the quarks and electrons constituting atoms. A new derivation of the connection between the ZPF and inertia has been carried through that is properly co-variant, yielding the relativistic equation of motion from Maxwell's equations. This opens new possibilities, but also rules out the basis of one hypothetical propulsion mechanism: Bondi's "negative inertial mass," appears to be an impossibility.

The simulation of electromagnetically driven strong Langmuir turbulence effect on the backscatter radiation from ionosphere

NASA Astrophysics Data System (ADS)

Kochetov, Andrey

2016-07-01

Numerical simulations of the dynamics of electromagnetic fields in a smoothly inhomogeneous nonlinear plasma layer in frameworks of the nonlinear Schrödinger equation with boundary conditions responsible for the pumping of the field in the layer by an incident wave and the inverse radiation losses supplemented the volume field dissipation due to the electromagnetic excitation of Langmuir turbulence are carried out. The effects of the threshold of non-linearity and it's evolution, of the threshold and saturation levels of dissipation in the vicinity of the wave reflection point on the features of the dynamics of reflection and absorption indexes are investigated. We consider the hard drive damping depending on the local field amplitude and hysteresis losses with different in several times "on" and "off" absorption thresholds as well. The dependence of the thresholds of the steady-state, periodic and chaotic regimes of plasma-wave interaction on the scenario of turbulence evolution is demonstrated. The results are compared with the experimental observations of Langmuir stage ionospheric modification.

Overview of the Chandra X-Ray Observatory Facility

NASA Technical Reports Server (NTRS)

Weisskopf, M. C.; Six, N. Frank (Technical Monitor)

2002-01-01

The Chandra X-Ray Observatory (originally called the Advanced X-Ray Astrophysics Facility - AXAF) is the X-Ray component of NASA's "Great Observatory" Program. Chandra is a NASA facility that provides scientific data to the international astronomical community in response to scientific proposals for its use. The Observatory is the product of the efforts of many organizations in the United States and Europe. The Great Observatories also include the Hubble Space Telescope for space-based observations of astronomical objects primarily in the visible portion of the electromagnetic spectrum, the now defunct Compton Gamma- Ray Observatory that was designed to observe gamma-ray emission from astronomical objects, and the soon-to-be-launched Space Infrared Telescope Facility (SIRTF). The Chandra X-Ray Observatory (hereafter CXO) is sensitive to X-rays in the energy range from below 0.1 to above 10.0 keV corresponding to wavelengths from 12 to 0.12 nanometers. The relationship among the various parts of the electromagnetic spectrum, sorted by characteristic temperature and the corresponding wavelength, is illustrated. The German physicist Wilhelm Roentgen discovered what he thought was a new form of radiation in 1895. He called it X-radiation to summarize its properties. The radiation had the ability to pass through many materials that easily absorb visible light and to free electrons from atoms. We now know that X-rays are nothing more than light (electromagnetic radiation) but at high energies. Light has been given many names: radio waves, microwaves, infrared, visible, ultraviolet, X-ray and gamma radiation are all different forms. Radio waves are composed of low energy particles of light (photons). Optical photons - the only photons perceived by the human eye - are a million times more energetic than the typical radio photon, whereas the energies of X-ray photons range from hundreds to thousands of times higher than that of optical photons. Very low temperature systems (hundreds of degrees below zero Celsius) produce low energy radio and microwave photons, whereas cool bodies like our own (about 30 degrees Celsius) produce infrared radiation. Very high temperatures (millions of degrees Celsius) are one way of producing X-rays.

Single-Electron Detection and Spectroscopy via Relativistic Cyclotron Radiation.

PubMed

Asner, D M; Bradley, R F; de Viveiros, L; Doe, P J; Fernandes, J L; Fertl, M; Finn, E C; Formaggio, J A; Furse, D; Jones, A M; Kofron, J N; LaRoque, B H; Leber, M; McBride, E L; Miller, M L; Mohanmurthy, P; Monreal, B; Oblath, N S; Robertson, R G H; Rosenberg, L J; Rybka, G; Rysewyk, D; Sternberg, M G; Tedeschi, J R; Thümmler, T; VanDevender, B A; Woods, N L

2015-04-24

It has been understood since 1897 that accelerating charges must emit electromagnetic radiation. Although first derived in 1904, cyclotron radiation from a single electron orbiting in a magnetic field has never been observed directly. We demonstrate single-electron detection in a novel radio-frequency spectrometer. The relativistic shift in the cyclotron frequency permits a precise electron energy measurement. Precise beta electron spectroscopy from gaseous radiation sources is a key technique in modern efforts to measure the neutrino mass via the tritium decay end point, and this work demonstrates a fundamentally new approach to precision beta spectroscopy for future neutrino mass experiments.

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

Broad band waveguide spectrometer

DOEpatents

Goldman, Don S.

1995-01-01

A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

Expanding the use of real-time electromagnetic tracking in radiation oncology.

PubMed

Shah, Amish P; Kupelian, Patrick A; Willoughby, Twyla R; Meeks, Sanford L

2011-11-15

In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery.

Expanding the use of real‐time electromagnetic tracking in radiation oncology

PubMed Central

Kupelian, Patrick A.; Willoughby, Twyla R.; Meeks, Sanford L.

2011-01-01

In the past 10 years, techniques to improve radiotherapy delivery, such as intensity‐modulated radiation therapy (IMRT), image‐guided radiation therapy (IGRT) for both inter‐ and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery. PACS number: 87.63.‐d PMID:22089017

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.

Monitoring dynamic reactions of red blood cells to UHF electromagnetic waves radiation using a novel micro-imaging technology.

PubMed

Ruan, Ping; Yong, Junguang; Shen, Hongtao; Zheng, Xianrong

2012-12-01

Multiple state-of-the-art techniques, such as multi-dimensional micro-imaging, fast multi-channel micro-spetrophotometry, and dynamic micro-imaging analysis, were used to dynamically investigate various effects of cell under the 900 MHz electromagnetic radiation. Cell changes in shape, size, and parameters of Hb absorption spectrum under different power density electromagnetic waves radiation were presented in this article. Experimental results indicated that the isolated human red blood cells (RBCs) do not have obviously real-time responses to the ultra-low density (15 μW/cm(2), 31 μW/cm(2)) electromagnetic wave radiation when the radiation time is not more than 30 min; however, the cells do have significant reactions in shape, size, and the like, to the electromagnetic waves radiation with power densities of 1 mW/cm(2) and 5 mW/cm(2). The data also reveal the possible influences and statistical relationships among living human cell functions, radiation amount, and exposure time with high-frequency electromagnetic waves. The results of this study may be significant on protection of human being and other living organisms against possible radiation affections of the high-frequency electromagnetic waves.

Effective dynamics of a classical point charge

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

Polonyi, Janos, E-mail: polonyi@iphc.cnrs.fr

2014-03-15

The effective Lagrangian of a point charge is derived by eliminating the electromagnetic field within the framework of the classical closed time path formalism. The short distance singularity of the electromagnetic field is regulated by an UV cutoff. The Abraham–Lorentz force is recovered and its similarity to quantum anomalies is underlined. The full cutoff-dependent linearized equation of motion is obtained, no runaway trajectories are found but the effective dynamics shows acausality if the cutoff is beyond the classical charge radius. The strength of the radiation reaction force displays a pole in its cutoff-dependence in a manner reminiscent of the Landau-polemore » of perturbative QED. Similarity between the dynamical breakdown of the time reversal invariance and dynamical symmetry breaking is pointed out. -- Highlights: •Extension of the classical action principle for dissipative systems. •New derivation of the Abraham–Lorentz force for a point charge. •Absence of a runaway solution of the Abraham–Lorentz force. •Acausality in classical electrodynamics. •Renormalization of classical electrodynamics of point charges.« less

[Pulse-modulated Electromagnetic Radiation of Extremely High Frequencies Protects Cellular DNA against Damaging Effect of Physico-Chemical Factors in vitro].

PubMed

Gapeyev, A B; Lukyanova, N A

2015-01-01

Using a comet assay technique, we investigated protective effects of. extremely high frequency electromagnetic radiation in combination with the damaging effect of X-ray irradiation, the effect of damaging agents hydrogen peroxide and methyl methanesulfonate on DNA in mouse whole blood leukocytes. It was shown that the preliminary exposure of the cells to low intensity pulse-modulated electromagnetic radiation (42.2 GHz, 0.1 mW/cm2, 20-min exposure, modulation frequencies of 1 and 16 Hz) caused protective effects decreasing the DNA damage by 20-45%. The efficacy of pulse-modulated electromagnetic radiation depended on the type of genotoxic agent and increased in a row methyl methanesulfonate--X-rays--hydrogen peroxide. Continuous electromagnetic radiation was ineffective. The mechanisms of protective effects may be connected with an induction of the adaptive response by nanomolar concentrations of reactive oxygen species formed by pulse-modulated electromagnetic radiation.

Measurement of the 100 MHz EMF radiation in vivo effects on zebrafish D. rerio embryonic development: A multidisciplinary study.

PubMed

Piccinetti, Chiara Carla; De Leo, Alfredo; Cosoli, Gloria; Scalise, Lorenzo; Randazzo, Basilio; Cerri, Graziano; Olivotto, Ike

2018-06-15

The augmented exposure of both environment and human being to electromagnetic waves and the concomitant lack of an unequivocal knowledge about biological consequences of these radiations, raised public interest on electromagnetic pollution. In this context, the present study aims to evaluate the biological effects on zebrafish (ZF) embryos of 100 MHz radiofrequency electromagnetic field (RF-EMF) exposure through a multidisciplinary protocol. Because of the shared synteny between human and ZF genomes that validated its use in biomedical research, toxicology and developmental biology studies, ZF was here selected as experimental model and a measurement protocol and biological analyses have been set up to clearly discriminate between RF-EMF biological and thermal effects. The results showed that a 100 MHz EMF was able to affect ZF embryonic development, from 24 to 72 h post fertilization (hpf) in all the analyzed pathways. Particularly, at the 48 hpf stage, a reduced growth, an increased transcription of oxidative stress genes, the onset of apoptotic/autophagic processes and a modification in cholesterol metabolism were detected. ZF embryos faced stress induced by EMF radiation by triggering detoxification mechanisms and at 72 hpf they partially recovered from stress reaching the hatching time in a comparable way respect to the control group. Data here obtained showed unequivocally the in vivo effects of RF-EMF on an animal model, excluding thermal outcomes and thus represents the starting point for more comprehensive studies on dose response effects of electromagnetic fields radiations consequences. Copyright © 2018 Elsevier Inc. All rights reserved.

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.

Laser Spiderweb Sensor Used with Portable Handheld Devices

NASA Technical Reports Server (NTRS)

Scott, David C. (Inventor); Ksendzov, Alexander (Inventor); George, Warren P. (Inventor); Smith, James A. (Inventor); Steinkraus, Joel M. (Inventor); Hofmann, Douglas C. (Inventor); Aljabri, Abdullah S. (Inventor); Bendig, Rudi M. (Inventor)

2017-01-01

A portable spectrometer, including a smart phone case storing a portable spectrometer, wherein the portable spectrometer includes a cavity; a source for emitting electromagnetic radiation that is directed on a sample in the cavity, wherein the electromagnetic radiation is reflected within the cavity to form multiple passes of the electromagnetic radiation through the sample; a detector for detecting the electromagnetic radiation after the electromagnetic radiation has made the multiple passes through the sample in the cavity, the detector outputting a signal in response to the detecting; and a device for communicating the signal to a smart phone, wherein the smart phone executes an application that performs a spectral analysis of the signal.

[Experimental research on the electromagnetic radiation immunity of a kind of portable monitor].

PubMed

Yuan, Jun; Xiao, Dongping; Jian, Xin

2010-11-01

The paper is focused on a kind of portable monitor that is widely used in military hospitals. In order to study the electromagnetic radiation immunity of the monitor, the experiments of electromagnetic radiation caused by radio frequency continuous wave in reverberation chamber and by ultra wide band (UWB) electromagnetic pulse have been done. The study results show that UWB electromagnetic pulse interferes observably the operating state of the monitor. It should be paid high attention to take protective measures. The monitor tested has some electromagnetic immunity ability for radio frequency continuous wave radiation. The frequent abnormal phenomena are baseline drift and waveform distortion. The electromagnetic sensitivity of the monitor is related to the frequency of interference source. The monitor tested is most sensitive to the frequency of 390 MHz.

Demonstration of Electro-Osmotic Pulse Technology in Earth-Covered Magazines at Fort A.P. Hill, VA

DTIC Science & Technology

2009-08-01

Electromagnetic Radiation to Ordnance ( HERO ) Evaluation Tests were conducted on magazines to detect any radio frequency (RF) emissions produced and to...measure electromagnetic (EM) radiation from the anodes installed in the magazines. The detailed results of a HERO ( Hazards of Electromagnetic ...reinforcement steel ........................................................... 14 3.3.6 Testing for electromagnetic radiation hazards

Brownian Emitters

NASA Astrophysics Data System (ADS)

Tsekov, Roumen

2016-06-01

A Brownian harmonic oscillator, which dissipates energy either by friction or via emission of electromagnetic radiation, is considered. This Brownian emitter is driven by the surrounding thermo-quantum fluctuations, which are theoretically described by the fluctuation-dissipation theorem. It is shown how the Abraham-Lorentz force leads to dependence of the half-width on the peak frequency of the oscillator amplitude spectral density. It is found that for the case of a charged particle moving in vacuum at zero temperature, its root-mean-square velocity fluctuation is a universal constant, equal to roughly 1/18 of the speed of light. The relevant Fokker-Planck and Smoluchowski equations are also derived.

Cloaking of arbitrarily shaped objects with homogeneous coatings

NASA Astrophysics Data System (ADS)

Forestiere, Carlo; Dal Negro, Luca; Miano, Giovanni

2014-05-01

We present a theory for the cloaking of arbitrarily shaped objects and demonstrate electromagnetic scattering cancellation through designed homogeneous coatings. First, in the small-particle limit, we expand the dipole moment of a coated object in terms of its resonant modes. By zeroing the numerator of the resulting rational function, we accurately predict the permittivity values of the coating layer that abates the total scattered power. Then, we extend the applicability of the method beyond the small-particle limit, deriving the radiation corrections of the scattering-cancellation permittivity within a perturbation approach. Our method permits the design of invisibility cloaks for irregularly shaped devices such as complex sensors and detectors.

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.

Semi-classical Reissner-Nordstrom model for the structure of charged leptons

NASA Technical Reports Server (NTRS)

Rosen, G.

1980-01-01

The lepton self-mass problem is examined within the framework of the quantum theory of electromagnetism and gravity. Consideration is given to the Reissner-Nordstrom solution to the Einstein-Maxwell classical field equations for an electrically charged mass point, and the WKB theory for a semiclassical system with total energy zero is used to obtain an expression for the Einstein-Maxwell action factor. The condition obtained is found to account for the observed mass values of the three charged leptons, and to be in agreement with the correspondence principle.

An Alternate Set of Basis Functions for the Electromagnetic Solution of Arbitrarily-Shaped, Three-Dimensional, Closed, Conducting Bodies Using Method of Moments

NASA Technical Reports Server (NTRS)

Mackenzie, Anne I.; Baginski, Michael E.; Rao, Sadasiva M.

2008-01-01

In this work, we present an alternate set of basis functions, each defined over a pair of planar triangular patches, for the method of moments solution of electromagnetic scattering and radiation problems associated with arbitrarily-shaped, closed, conducting surfaces. The present basis functions are point-wise orthogonal to the pulse basis functions previously defined. The prime motivation to develop the present set of basis functions is to utilize them for the electromagnetic solution of dielectric bodies using a surface integral equation formulation which involves both electric and magnetic cur- rents. However, in the present work, only the conducting body solution is presented and compared with other data.

In Situ Magnetic Field Measurement using the Hanle Effect

NASA Astrophysics Data System (ADS)

Jackson, Jarom; Durfee, Dallin

2016-05-01

We have developed a simple method of in situ magnetic field mapping near zero points in magnetic fields. It is ideal for measuring trapping parameters such the field gradient and curvature, and should be applicable in most experiments with a magneto-optical trap (MOT) or similar setup. This method works by probing atomic transitions in a vacuum, and is based on the Hanle effect, which alters the polarization of spontaneous emission in the presence of a magnetic field. Unlike most techniques based on the Hanle effect, however, we look only at intensity. Instead of measuring polarization we use the change in directional radiation patterns caused by a magnetic field. Using one of the cooling beams for our MOT, along with a linear polarizer, a narrow slit, and an inexpensive webcam, we measure the three dimensional position of a magnetic field zero point within our vacuum to within +/-1 mm and the gradient through the zero point to an accuracy of 4%. This work was supported by NSF Grant Number PHY-1205736.

[Changes in physico-chemical parameters of homeopathic remedies ferrum metallicum CH6 and ferrum metallicum CH30 after exposure to high frequency electromagnetic radiation of low intensity].

PubMed

Mendez, N M

2005-01-01

It is considered the microwaves electromagnetic radiation do not affect the materials, alive or not, when used in low power. In high power, the interaction effects would be the material warming (thermal effect). However, in the last years, the studies about electromagnetic radiation with low power (non thermal effect) in the human being have been increasing. It was found out the electromagnetic radiation, even with low power, can affect the living organisms and biosubstratum. In the present work the influence of electromagnetic radiation (2.45 GHz 500 W/cm2), on physical and chemical parameters of the homeopathic pharmaceutics products in shown.

The electromagnetic environment of hospitals: how it is affected by the strength of electromagnetic fields generated both inside and outside the hospital.

PubMed

Hanada, Eisuke

2007-01-01

Most problems with the electromagnetic environment of medical institutions have been related to radiated electromagnetic fields and have been constructed from reports about electromagnetic interference (EMI) with electronic medical equipment by the radio waves emitted from mobile telephone handsets. However, radiated electromagnetic fields are just one of the elements. For example, little attention has been placed on problems with the electric power source. Apparatus for clinical treatment and diagnosis that use electric power sources have come into wide use in hospitals. Hospitals must pay careful attention to all elements of the electromagnetic environment. Herein, I will show examples of measurements and measuring methods for radiated electromagnetic fields, static magnetic fields, and power-source noise, common components of the medical electromagnetic environment.

Computational Electromagnetic Studies for Low-Frequency Compensation of the Reflector Impulse-radiating Antenna

DTIC Science & Technology

2015-03-26

COMPUTATIONAL ELECTROMAGNETIC STUDIES FOR LOW-FREQUENCY COMPENSATION OF THE REFLECTOR IMPULSE-RADIATING ANTENNA THESIS Casey E. Fillmore, Capt, USAF... ELECTROMAGNETIC STUDIES FOR LOW-FREQUENCY COMPENSATION OF THE REFLECTOR IMPULSE-RADIATING ANTENNA THESIS Presented to the Faculty Department of Electrical and...2015 DISTRIBUTION STATEMENT A APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED. AFIT-ENG-MS-15-M-011 COMPUTATIONAL ELECTROMAGNETIC STUDIES FOR LOW

LeadingEdge: Challenges and Solutions for the 21st Century, Electromagnetic Environmental Effects. Volume 7, Issue 1, 2009

DTIC Science & Technology

2009-01-01

Hazards of Electromagnet - ic Radiation to Ordnance ( HERO ). Below decks spaces, such as ammunition storage lockers and...Navy’s Hazards of Electromagnetic Radiation to Ordnance ( HERO ) program. Unlike other services deployed in our nation’s defense, our sailors liter...also provides infor- mation on other general HERO requirements. The Electromagnetic Radiation Hazards ( Hazards to Ordnance ) Datasheets2

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.

Dielectric waveguide with transverse index variation that support a zero group velocity mode at a non-zero longitudinal wavevector

DOEpatents

Ibanescu, Mihai; Joannopoious, John D.; Fink, Yoel; Johnson, Steven G.; Fan, Shanhui

2005-06-21

Optical components including a laser based on a dielectric waveguide extending along a waveguide axis and having a refractive index cross-section perpendicular to the waveguide axis, the refractive index cross-section supporting an electromagnetic mode having a zero group velocity for a non-zero wavevector along the waveguide axis.

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.

Compound simulator IR radiation characteristics test and calibration

NASA Astrophysics Data System (ADS)

Li, Yanhong; Zhang, Li; Li, Fan; Tian, Yi; Yang, Yang; Li, Zhuo; Shi, Rui

2015-10-01

The Hardware-in-the-loop simulation can establish the target/interference physical radiation and interception of product flight process in the testing room. In particular, the simulation of environment is more difficult for high radiation energy and complicated interference model. Here the development in IR scene generation produced by a fiber array imaging transducer with circumferential lamp spot sources is introduced. The IR simulation capability includes effective simulation of aircraft signatures and point-source IR countermeasures. Two point-sources as interference can move in two-dimension random directions. For simulation the process of interference release, the radiation and motion characteristic is tested. Through the zero calibration for optical axis of simulator, the radiation can be well projected to the product detector. The test and calibration results show the new type compound simulator can be used in the hardware-in-the-loop simulation trial.

Toward an interstellar mission: Zeroing in on the zero-point-field inertia resonance

NASA Astrophysics Data System (ADS)

Haisch, Bernhard; Rueda, Alfonso

2000-01-01

While still an admittedly remote possibility, the concept of an interstellar mission has become a legitimate topic for scientific discussion as evidenced by several recent NASA activities and programs. One approach is to extrapolate present-day technologies by orders of magnitude; the other is to find new regimes in physics and to search for possible new laws of physics. Recent work on the zero-point field (ZPF), or electromagnetic quantum vacuum, is promising in regard to the latter, especially concerning the possibility that the inertia of matter may, at least in part, be attributed to interaction between the quarks and electrons in matter and the ZPF. A NASA-funded study (independent of the BPP program) of this concept has been underway since 1996 at the Lockheed Martin Advanced Technology Center in Palo Alto and the California State University at Long Beach. We report on a new development resulting from this effort: that for the specific case of the electron, a resonance for the inertia-generating process at the Compton frequency would simultaneously explain both the inertial mass of the electron and the de Broglie wavelength of a moving electron as first measured by Davisson and Germer in 1927. This line of investigation is leading to very suggestive connections between electrodynamics, inertia, gravitation and the wave nature of matter. .

Acoustic radiation force control: Pulsating spherical carriers.

PubMed

Rajabi, Majid; Mojahed, Alireza

2018-02-01

The interaction between harmonic plane progressive acoustic beams and a pulsating spherical radiator is studied. The acoustic radiation force function exerted on the spherical body is derived as a function of the incident wave pressure and the monopole vibration characteristics (i.e., amplitude and phase) of the body. Two distinct strategies are presented in order to alter the radiation force effects (i.e., pushing and pulling states) by changing its magnitude and direction. In the first strategy, an incident wave field with known amplitude and phase is considered. It is analytically shown that the zero- radiation force state (i.e., radiation force function cancellation) is achievable for specific pulsation characteristics belong to a frequency-dependent straight line equation in the plane of real-imaginary components (i.e., Nyquist Plane) of prescribed surface displacement. It is illustrated that these characteristic lines divide the mentioned displacement plane into two regions of positive (i.e., pushing) and negative (i.e., pulling) radiation forces. In the second strategy, the zero, negative and positive states of radiation force are obtained through adjusting the incident wave field characteristics (i.e., amplitude and phase) which insonifies the radiator with prescribed pulsation characteristics. It is proved that zero radiation force state occurs for incident wave pressure characteristics belong to specific frequency-dependent circles in Nyquist plane of incident wave pressure. These characteristic circles divide the Nyquist plane into two distinct regions corresponding to positive (out of circles) and negative (in the circles) values of radiation force function. It is analytically shown that the maximum amplitude of negative radiation force is exactly equal to the amplitude of the (positive) radiation force exerted upon the sphere in the passive state, by the same incident field. The developed concepts are much more deepened by considering the required power supply for distinct cases of zero, negative and positive radiation force states along with the frequency dependent asymmetry index. In addition, considering the effect of phase difference between the incident wave field and the pulsating object, and its possible variation with respect to spatial position of object, some practical points about the spatial average of generated radiation force, the optimal state of operation, the stability of zero radiation force states and the possibly of precise motion control are discussed. This work would extend the novel concept of smart carriers to and may be helpful for robust single-beam acoustic handling techniques. Furthermore, the shown capability of precise motion control may be considered as a new way toward smart acoustic driven micro-mechanisms and micro-machines. Copyright © 2017 Elsevier B.V. All rights reserved.

Simulation of π 0-γ separation study for proposed CMS forward electromagnetic calorimeter

DOE PAGES

Roy, Ashim; Jain, Shilpi; Banerjee, Sunanda; ...

2016-11-11

The Forward Electromagnetic Calorimeter of the CMS detector is going to be upgraded in the high luminosity running as the energy of the present Electromagnetic Calorimeter (PbWO4) will degrade in the high luminosity (luminosity 10 34 cm -2 s -1) running due to extensive radiation (hadron flux 10 13 neutrons cm, -2). Shashlik Electromagnetic Calorimeter which consists of alternate layers of 1.5 mm LYSO(Ce) crystal plates and 2.5 mm Tungsten absorbers, was a proposal for high luminosity running. One of the performance points for any electromagnetic calorimeter is the ability to separate π 0 s from true photons, since finalmore » states with photons are a clean and one of the most important final states in proton-proton collisions at the LHC. As a result, the objective of this project is to study the possibility of π 0 and γ separation in the Shashlik detector using Multivariate Analysis (MVA) technique.« less

Simulation of π 0-γ separation study for proposed CMS forward electromagnetic calorimeter

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

Roy, Ashim; Jain, Shilpi; Banerjee, Sunanda

The Forward Electromagnetic Calorimeter of the CMS detector is going to be upgraded in the high luminosity running as the energy of the present Electromagnetic Calorimeter (PbWO4) will degrade in the high luminosity (luminosity 10 34 cm -2 s -1) running due to extensive radiation (hadron flux 10 13 neutrons cm, -2). Shashlik Electromagnetic Calorimeter which consists of alternate layers of 1.5 mm LYSO(Ce) crystal plates and 2.5 mm Tungsten absorbers, was a proposal for high luminosity running. One of the performance points for any electromagnetic calorimeter is the ability to separate π 0 s from true photons, since finalmore » states with photons are a clean and one of the most important final states in proton-proton collisions at the LHC. As a result, the objective of this project is to study the possibility of π 0 and γ separation in the Shashlik detector using Multivariate Analysis (MVA) technique.« less

Free Electron coherent sources: From microwave to X-rays

NASA Astrophysics Data System (ADS)

Dattoli, Giuseppe; Di Palma, Emanuele; Pagnutti, Simonetta; Sabia, Elio

2018-04-01

The term Free Electron Laser (FEL) will be used, in this paper, to indicate a wide collection of devices aimed at providing coherent electromagnetic radiation from a beam of "free" electrons, unbound at the atomic or molecular states. This article reviews the similarities that link different sources of coherent radiation across the electromagnetic spectrum from microwaves to X-rays, and compares the analogies with conventional laser sources. We explore developing a point of view that allows a unified analytical treatment of these devices, by the introduction of appropriate global variables (e.g. gain, saturation intensity, inhomogeneous broadening parameters, longitudinal mode coupling strength), yielding a very effective way for the determination of the relevant design parameters. The paper looks also at more speculative aspects of FEL physics, which may address the relevance of quantum effects in the lasing process.

Containerless study of metal evaporation by laser induced fluorescence

NASA Technical Reports Server (NTRS)

Schiffman, Robert A.; Nordine, Paul C.

1987-01-01

Laser induced fluorescence (LIF) detection of atomic vapors was used to study evaporation from electromagnetically levitated and CW CO2 laser-heated molybdenum spheres and resistively-heated tungsten filaments. Electromagnetic (EM) levitation in combination with laser heating of tungsten, zirconium, and aluminum specimens was also investigated. LIF intensity vs temperature data were obtained for molybdenum atoms and six electronic states of atomic tungsten, at temperatures up to the melting point of each metal. The detected fraction of the emitted radiation was reduced by self-absorption effects at the higher experimental temperatures. Vaporization enthalpies derived from data for which less than half the LIF intensity was self-absorbed were -636 + or - 24 kJ/g-mol for Mo and 831 + or - 32 kJ/g-mol for W. Space-based applications of EM levitation in combination with radiative heating are discussed.

Electromagnetic radiation accompanying gravitational waves from black hole binaries

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

Dolgov, A.; Postnov, K., E-mail: dolgov@fe.infn.it, E-mail: kpostnov@gmail.com

The transition of powerful gravitational waves, created by the coalescence of massive black hole binaries, into electromagnetic radiation in external magnetic fields is considered. In contrast to the previous calculations of the similar effect we study the realistic case of the gravitational radiation frequency below the plasma frequency of the surrounding medium. The gravitational waves propagating in the plasma constantly create electromagnetic radiation dragging it with them, despite the low frequency. The plasma heating by the unattenuated electromagnetic wave may be significant in hot rarefied plasma with strong magnetic field and can lead to a noticeable burst of electromagnetic radiationmore » with higher frequency. The graviton-to-photon conversion effect in plasma is discussed in the context of possible electromagnetic counterparts of GW150914 and GW170104.« less

Apparatus for processing electromagnetic radiation and method

NASA Technical Reports Server (NTRS)

Gatewood, George D. (Inventor)

1983-01-01

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

Detection of electromagnetic radiation using nonlinear materials

DOEpatents

Hwang, Harold Y.; Liu, Mengkun; Averitt, Richard D.; Nelson, Keith A.; Sternbach, Aaron; Fan, Kebin

2016-06-14

An apparatus for detecting electromagnetic radiation within a target frequency range is provided. The apparatus includes a substrate and one or more resonator structures disposed on the substrate. The substrate can be a dielectric or semiconductor material. Each of the one or more resonator structures has at least one dimension that is less than the wavelength of target electromagnetic radiation within the target frequency range, and each of the resonator structures includes at least two conductive structures separated by a spacing. Charge carriers are induced in the substrate near the spacing when the resonator structures are exposed to the target electromagnetic radiation. A measure of the change in conductivity of the substrate due to the induced charge carriers provides an indication of the presence of the target electromagnetic radiation.

Pregnancy and Radiation Exposure

MedlinePlus

... pregnant women. Ionizing radiation is the kind of electromagnetic radiation produced by x-ray machines, radioactive isotopes ( ... The reproductive risk of nonionizing radiation, which includes electromagnetic fields emitted from computers, microwave communication systems, microwave ...

[Effect of decimeter polarized electromagnetic radiation on germinating capacity of seeds].

PubMed

Polevik, N D

2013-01-01

The effect of a polarization structure of electromagnetic radiation on the germinating capacity of seeds of such weeds as Green foxtail (Setaria viridis) and Green amaranth (Amaranthus retroflexus) has been studied. Seeds have been exposed to impulse electromagnetic radiation in a frequency of 896 MHz with linear, elliptical right-handed and elliptical left-handed polarizations at different power flux density levels. It is determined that the effect of the right-handed polarized electromagnetic radiation increases and the influence of the left-handed polarized one reduces the germinating capacity of seeds compared to the effect of the linearly polarized electromagnetic radiation. It is shown that the seeds have an amplitude polarization selectivity as evinced by the major effect of the right-handed polarized radiation on seeds. An electrodynamic model as the right-handed elliptically polarized antenna with the given quantity of the ellipticity of polarization is suggested to use in description of this selectivity.

THz electromagnetic radiation driven by intense relativistic electron beam based on ion focus regime

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

Zhou, Qing; Xu, Jin; Zhang, Wenchao

The simulation study finds that the relativistic electron beam propagating through the plasma background can produce electromagnetic (EM) radiation. With the propagation of the electron beam, the oscillations of the beam electrons in transverse and longitudinal directions have been observed simultaneously, which provides the basis for the electromagnetic radiation. The simulation results clearly show that the electromagnetic radiation frequency can reach up to terahertz (THz) wave band which may result from the filter-like property of plasma background, and the electromagnetic radiation frequency closely depends on the plasma density. To understand the above simulation results physically, the dispersion relation of themore » beam-plasma system has been derived using the field-matching method, and the dispersion curves show that the slow wave modes can couple with the electron beam effectively in THz wave band, which is an important theoretical evidence of the EM radiation.« less

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

Reflection technique for thermal mapping of semiconductors

DOEpatents

Walter, Martin J.

1989-06-20

Semiconductors may be optically tested for their temperatures by illuminating them with tunable monochromatic electromagnetic radiation and observing the light reflected off of them. A transition point will occur when the wavelength of the light corresponds with the actual band gap energy of the semiconductor. At the transition point, the image of the semiconductor will appreciably darken as the light is transmitted through it, rather than being reflected off of it. The wavelength of the light at the transition point corresponds to the actual band gap energy and the actual temperature of the semiconductor.

[The role of RKIP mediated ERK pathway in hippocampus neurons injured by electromagnetic radiation].

PubMed

Zuo, Hong-Yan; Wang, De-Wen; Peng, Rui-Yun; Wang, Shui-Ming; Gao, Ya-Bing; Zhang, Zhi-Yi; Xiao, Feng-Jun

2008-07-01

To study the effects of electromagnetic radiation on RKIP and phosphorylated ERK in primary cultured hippocampus neurons. The inhibitor of MEK U0126 was applied to investigate the role of RKIP mediated ERK pathway in radiation injury. Primary hippocampus neurons were cultured in vitro. X-HPM, S-HPM and EMP were taken as radiation source respectively to establish three cell models exposed to electromagnetic radiation. RKIP and phosphorylated ERK were measured by immunofluorescent labelling and laser scanning confocal microscope. Apoptosis and death fraction of the cells were detected by Annexin V-PI double labelling and flow cytometry. After three kinds of electromagnetic radiation, the expression of RKIP in hippocampus neurons decreased but the expression of phosphorylated ERK increased, and its nuclear translocation occurred. No significant differences were seen between radiation groups. Apoptosis and death fraction of the neurons in U0126 pretreatment groups was significantly lower than that in radiation groups but they were still higher than those in sham-radiation group. The excessive activation of RKIP mediated ERK pathway is one of the important mechanisms for the apoptosis and death of hippocampus neurons induced by electromagnetic radiation. U0126 have some protective effects on radiation injury.

Imaging tooth enamel using zero echo time (ZTE) magnetic resonance imaging

NASA Astrophysics Data System (ADS)

Rychert, Kevin M.; Zhu, Gang; Kmiec, Maciej M.; Nemani, Venkata K.; Williams, Benjamin B.; Flood, Ann B.; Swartz, Harold M.; Gimi, Barjor

2015-03-01

In an event where many thousands of people may have been exposed to levels of radiation that are sufficient to cause the acute radiation syndrome, we need technology that can estimate the absorbed dose on an individual basis for triage and meaningful medical decision making. Such dose estimates may be achieved using in vivo electron paramagnetic resonance (EPR) tooth biodosimetry, which measures the number of persistent free radicals that are generated in tooth enamel following irradiation. However, the accuracy of dose estimates may be impacted by individual variations in teeth, especially the amount and distribution of enamel in the inhomogeneous sensitive volume of the resonator used to detect the radicals. In order to study the relationship between interpersonal variations in enamel and EPR-based dose estimates, it is desirable to estimate these parameters nondestructively and without adding radiation to the teeth. Magnetic Resonance Imaging (MRI) is capable of acquiring structural and biochemical information without imparting additional radiation, which may be beneficial for many EPR dosimetry studies. However, the extremely short T2 relaxation time in tooth structures precludes tooth imaging using conventional MRI methods. Therefore, we used zero echo time (ZTE) MRI to image teeth ex vivo to assess enamel volumes and spatial distributions. Using these data in combination with the data on the distribution of the transverse radio frequency magnetic field from electromagnetic simulations, we then can identify possible sources of variations in radiation-induced signals detectable by EPR. Unlike conventional MRI, ZTE applies spatial encoding gradients during the RF excitation pulse, thereby facilitating signal acquisition almost immediately after excitation, minimizing signal loss from short T2 relaxation times. ZTE successfully provided volumetric measures of tooth enamel that may be related to variations that impact EPR dosimetry and facilitate the development of analytical procedures for individual dose estimates.

IR detection and energy harvesting using antenna coupled MIM tunnel diodes

NASA Astrophysics Data System (ADS)

Yesilkoy, Filiz

The infrared (IR) spectrum lies between the microwave and optical frequency ranges, which are well suited for communication and energy harvesting purposes, respectively. The long wavelength IR (LWIR) spectrum, corresponding to wavelengths from 8microm to 15microm, includes the thermal radiation emitted by objects at room temperature and the Earth's terrestrial radiation. Therefore, LWIR detectors are very appealing for thermal imaging purposes. Thermal detectors developed so far either demand cryogenic operation for fast detection, or they rely on the accumulation of thermal energy in their mass and subsequent measurable changes in material properties. Therefore, they are relatively slow. Quantum detectors allow for tunable and instantaneous detection but are expensive and require complex processes for fabrication. Bolometer detectors are simple and cheap but do not allow for tunability or for rapid detection. Harvesting the LWIR radiation energy sourced by the Earth's heating/cooling cycle is very important for the development of mobile energy resources. While speed is not as significant an issue here, conversion efficiency is an eminent problem for cheap, large area energy transduction. This dissertation addresses the development of tunable, fast, and low cost wave detectors that can operate at room temperature and, when produced in large array format, can harvest Earth's terrestrial radiation energy. This dissertation demonstrates the design, fabrication and testing of Antenna Coupled Metal-Insulator-Metal (ACMIM) tunnel diodes optimized for 10microm wavelength radiation detection. ACMIM tunnel diodes operate as electromagnetic wave detectors: the incident radiation is coupled by an antenna and converted into a 30 terahertz signal that is rectified by a fast tunneling MIM diode. For efficient IR radiation coupling, the antenna geometry and its critical dimensions are studied using a commercial finite-element based multi-physics simulation tool, and the half-wave dipole-like bow-tie antennas are fabricated using simulation-optimized geometries. The major challenge of this work is designing and fabricating MIM diodes and coupled antennas with internal capacitances and resistances small enough to allow response in the desired frequency range (˜30 THz) and yet capable of efficiently coupling to the incident radiation. It is crucial to keep the RC time constant of the tunnel junction small to achieve the requisite cut-off frequency and adequate rectification efficiency. Moreover, a low junction resistance is necessary to load the coupled AC power across the MIM junction. For energy harvesting applications, the device has to operate without an external bias, which requires asymmetry at the zero bias operation point. To address these requirements, the MIM tunnel junction is established so that one electrode has a field enhancing sharp tip (cathode) and the other is a rectangular patch. This asymmetric geometry not only offers asymmetric current-voltage behavior at the zero bias point, but also it decouples the junction resistance and capacitance by concentrating the charge transport in a small volume around the tip. Various fabrication methods are developed in order to create small junction area (= low parasitic capacitance), low junction resistance (= effective power coupling through antenna), asymmetry (= zero bias operation), high fabrication yield and low cost ACMIM tunnel diodes. High resolution fabrication needs are accomplished by electron beam lithography and nano-accuracy in the junction area is achieved by employing dose modifying proximity effect correction and critical alignment methods. Our Ni/NiOx/Ni ACMIM diodes with an optimized insulation layer created with O2 plasma oxidation are the most successful devices presented to date. A novel fabrication technique called "strain assisted self lift-off process" is used to achieve small junction area devices without relying on lithographic resolution. This technique eliminates the rival parasitic capacitance issue of today's ACMIM tunnel diodes and does not rely on extreme-high resolution lithography technologies.

Radiofrequency radiation injures trees around mobile phone base stations.

PubMed

Waldmann-Selsam, Cornelia; Balmori-de la Puente, Alfonso; Breunig, Helmut; Balmori, Alfonso

2016-12-01

In the last two decades, the deployment of phone masts around the world has taken place and, for many years, there has been a discussion in the scientific community about the possible environmental impact from mobile phone base stations. Trees have several advantages over animals as experimental subjects and the aim of this study was to verify whether there is a connection between unusual (generally unilateral) tree damage and radiofrequency exposure. To achieve this, a detailed long-term (2006-2015) field monitoring study was performed in the cities of Bamberg and Hallstadt (Germany). During monitoring, observations and photographic recordings of unusual or unexplainable tree damage were taken, alongside the measurement of electromagnetic radiation. In 2015 measurements of RF-EMF (Radiofrequency Electromagnetic Fields) were carried out. A polygon spanning both cities was chosen as the study site, where 144 measurements of the radiofrequency of electromagnetic fields were taken at a height of 1.5m in streets and parks at different locations. By interpolation of the 144 measurement points, we were able to compile an electromagnetic map of the power flux density in Bamberg and Hallstadt. We selected 60 damaged trees, in addition to 30 randomly selected trees and 30 trees in low radiation areas (n=120) in this polygon. The measurements of all trees revealed significant differences between the damaged side facing a phone mast and the opposite side, as well as differences between the exposed side of damaged trees and all other groups of trees in both sides. Thus, we found that side differences in measured values of power flux density corresponded to side differences in damage. The 30 selected trees in low radiation areas (no visual contact to any phone mast and power flux density under 50μW/m 2 ) showed no damage. Statistical analysis demonstrated that electromagnetic radiation from mobile phone masts is harmful for trees. These results are consistent with the fact that damage afflicted on trees by mobile phone towers usually start on one side, extending to the whole tree over time. Copyright © 2016 Elsevier B.V. All rights reserved.

The attainment of large accelerating gradients using near field synchrotron radiation

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

Decker, G.

1989-01-01

Lienard-Wiechert potentials are used to find the electromagnetic field everywhere in free space resulting from a point charge moving on a helical trajectory. The total power emitted as synchrotron radiation from a particle on a circular path is calculated. The point charge results are generalized to the case of a line charge, and formulae are presented which can easily be evaluated numerically. A useful gradient of 80 MeV/m per kA of peak driving beam current over a distance of 1 cm is calculated using two 5 MeV driving beams moving on 1 cm radius helical orbits with bunch length 1more » mm. 11 refs., 5 figs.« less

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

Relativistically strong electromagnetic radiation in a plasma

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

Bulanov, S. V., E-mail: svbulanov@gmail.com, E-mail: bulanov.sergei@jaea.go.jp; Esirkepov, T. Zh.; Kando, M.

Physical processes in a plasma under the action of relativistically strong electromagnetic waves generated by high-power lasers have been briefly reviewed. These processes are of interest in view of the development of new methods for acceleration of charged particles, creation of sources of bright hard electromagnetic radiation, and investigation of macroscopic quantum-electrodynamical processes. Attention is focused on nonlinear waves in a laser plasma for the creation of compact electron accelerators. The acceleration of plasma bunches by the radiation pressure of light is the most efficient regime of ion acceleration. Coherent hard electromagnetic radiation in the relativistic plasma is generated inmore » the form of higher harmonics and/or electromagnetic pulses, which are compressed and intensified after reflection from relativistic mirrors created by nonlinear waves. In the limit of extremely strong electromagnetic waves, radiation friction, which accompanies the conversion of radiation from the optical range to the gamma range, fundamentally changes the behavior of the plasma. This process is accompanied by the production of electron–positron pairs, which is described within quantum electrodynamics theory.« less

The Inertia Reaction Force and Its Vacuum Origin

NASA Astrophysics Data System (ADS)

Rueda, Alfonso; Haisch, Bernard

By means of a covariant approach we show that there must be a contribution to the inertial mass and to the inertial reaction force on an accelerated massive object by the zero-point electromagnetic field. This development does not require any detailed model of the accelerated object other than the knowledge that it interacts electromagnetically. It is shown that inertia can indeed be construed as an opposition of the vacuum fields to any change to the uniform state of motion of an object. Interesting insights originating from this result are discussed. It is argued why the proposed existence of a Higgs field in no way contradicts or is at odds with the above statements. The Higgs field is responsible for assigning mass to elementary particles. It is argued that still the underlying reason for the opposition to acceleration that massive objects present requires an explanation. The explanation proposed here fulfills that requirement.

Towards measuring quantum electrodynamic torque with a levitated nanorod

NASA Astrophysics Data System (ADS)

Xu, Zhujing; Bang, Jaehoon; Ahn, Jonghoon; Hoang, Thai M.; Li, Tongcang

2017-04-01

According to quantum electrodynamics, quantum fluctuations of electromagnetic fields give rise to a zero-point energy that never vanishes, even in the absence of electromagnetic sources. The interaction energy will not only lead to the well-known Casimir force but will also contribute to the Casimir torque for anisotropic materials. We propose to use an optically levitated nanorod in vacuum and a birefringent substrate to experimentally investigate the QED torque. We have previously observed the libration of an optically levitated non-spherical nanoparticle in vacuum and found it to be an ultrasensitive torque sensor. A nanorod with a long axis of 300nm and a diameter of 60nm levitated in vacuum at 10 (- 8) torr will have a remarkable torque detection sensitivity on the order of 10 (- 28) Nm/ √Hz, which will be sufficient to detect the Casimir torque. This work is partially supported by the National Science Foundation under Grant No.1555035-PHY.

Quantum Optomechanics with Silicon Nanostructures

NASA Astrophysics Data System (ADS)

Safavi-Naeini, Amir H.

Mechanical resonators are the most basic and ubiquitous physical systems known. In on-chip form, they are used to process high frequency signals in every cell phone, television, and laptop. They have also been in the last few decades in different shapes and forms, a critical part of progress in quantum information sciences with kilogram scale mirrors for gravitational wave detection measuring motion at its quantum limits, and the motion of single ions being used to link qubits for quantum computation. Optomechanics is a field primarily concerned with coupling light to the motion of mechanical structures. This thesis contains descriptions of recent work with mechanical systems in the megahertz to gigahertz frequency range, formed by nanofabricating novel photonic/phononic structures on a silicon chip. These structures are designed to have both optical and mechanical resonances, and laser light is used to address and manipulate their motional degrees of freedom through radiation pressure forces. We laser cool these mechanical resonators to their ground states, and observe for the first time the quantum zero-point motion of a nanomechanical resonator. Conversely, we show that engineered mechanical resonances drastically modify the optical response of our structures, creating large effective optical nonlinearities not present in bulk silicon. We experimentally demonstrate aspects of these nonlinearities by proposing and observing ``electromagnetically induced transparency'' and light slowed down to 6 m/s, as well as wavelength conversion, and generation of nonclassical optical radiation. Finally, the application of optomechanics to longstanding problems in quantum and classical communications are proposed and investigated.

Electromagnetic diffraction radiation of a subwavelength-hole array excited by an electron beam.

PubMed

Liu, Shenggang; Hu, Min; Zhang, Yaxin; Li, Yuebao; Zhong, Renbin

2009-09-01

This paper explores the physics of the electromagnetic diffraction radiation of a subwavelength holes array excited by a set of evanescent waves generated by a line charge of electron beam moving parallel to the array. Activated by a uniformly moving line charge, numerous physical phenomena occur such as the diffraction radiation on both sides of the array as well as the electromagnetic penetration or transmission below or above the cut-off through the holes. As a result the subwavelength holes array becomes a radiation array. Making use of the integral equation with relevant Green's functions, an analytical theory for such a radiation system is built up. The results of the numerical calculations based on the theory agree well with that obtained by the computer simulation. The relation among the effective surface plasmon wave, the electromagnetic penetration or transmission of the holes and the diffraction radiation is revealed. The energy dependence of and the influence of the hole thickness on the diffraction radiation and the electromagnetic penetration or transmission are investigated in detail. Therefore, a distinct diffraction radiation phenomenon is discovered.

Development and implementation of the software for visualization and analysis of data geophysical loggers

NASA Astrophysics Data System (ADS)

Gordeev, V. F.; Malyshkov, S. Yu.; Botygin, I. A.; Sherstnev, V. S.; Sherstneva, A. I.

2017-11-01

The general trend of modern ecological geophysics is changing priorities towards rapid assessment, management and prediction of ecological and engineering soil stability as well as developing brand new geophysical technologies. The article describes researches conducted by using multi-canal geophysical logger MGR-01 (developed by IMCES SB RAS), which allows to measure flux density of very low-frequency electromagnetic radiation. It is shown that natural pulsed electromagnetic fields of the earthen lithosphere can be a source of new information on Earth's crust and processes in it, including earthquakes. The device is intended for logging electromagnetic processes in Earth's crust, geophysical exploration, finding structural and lithological inhomogeneities, monitoring the geodynamic movement of Earth's crust, express assessment of seismic hazards. The data is gathered automatically from observation point network in Siberia

New Basis Functions for the Electromagnetic Solution of Arbitrarily-shaped, Three Dimensional Conducting Bodies Using Method of Moments

NASA Technical Reports Server (NTRS)

Mackenzie, Anne I.; Baginski, Michael E.; Rao, Sadasiva M.

2007-01-01

In this work, we present a new set of basis functions, de ned over a pair of planar triangular patches, for the solution of electromagnetic scattering and radiation problems associated with arbitrarily-shaped surfaces using the method of moments solution procedure. The basis functions are constant over the function subdomain and resemble pulse functions for one and two dimensional problems. Further, another set of basis functions, point-wise orthogonal to the first set, is also de ned over the same function space. The primary objective of developing these basis functions is to utilize them for the electromagnetic solution involving conducting, dielectric, and composite bodies. However, in the present work, only the conducting body solution is presented and compared with other data.

New Basis Functions for the Electromagnetic Solution of Arbitrarily-shaped, Three Dimensional Conducting Bodies using Method of Moments

NASA Technical Reports Server (NTRS)

Mackenzie, Anne I.; Baginski, Michael E.; Rao, Sadasiva M.

2008-01-01

In this work, we present a new set of basis functions, defined over a pair of planar triangular patches, for the solution of electromagnetic scattering and radiation problems associated with arbitrarily-shaped surfaces using the method of moments solution procedure. The basis functions are constant over the function subdomain and resemble pulse functions for one and two dimensional problems. Further, another set of basis functions, point-wise orthogonal to the first set, is also defined over the same function space. The primary objective of developing these basis functions is to utilize them for the electromagnetic solution involving conducting, dielectric, and composite bodies. However, in the present work, only the conducting body solution is presented and compared with other data.

"Bio-lighting." Lighting Techniques in Architecture (Madison, December 9-10, 1969).

ERIC Educational Resources Information Center

Logan, H. L.

The electromagnetic environment has a great amount of influence on the existence of life and man. The main points of concern are--(1) that sea-level solar radiation is biologically beneficial and necessary for man's physical and mental health, (2) that urban man has inadequate exposure to certain wavelengths of ultraviolet light normally received…

Influence of electromagnetic radiation produced by mobile phone on some biophysical blood properties in rats.

PubMed

El-Bediwi, Abu Bakr; Saad, Mohamed; El-kott, Attall F; Eid, Eman

2013-04-01

Effects of electromagnetic radiation produced by mobile phone on blood viscosity, plasma viscosity, hemolysis, Osmotic fragility, and blood components of rats have been investigated. Experimental results show that there are significant change on blood components and its viscosity which affects on a blood circulation due to many body problems. Red blood cells, White blood cells, and Platelets are broken after exposure to electromagnetic radiation produced by mobile phone. Also blood viscosity and plasma viscosity values are increased but Osmotic fragility value decreased after exposure to electromagnetic radiation produced by mobile phone.

Quantum treatment of field propagation in a fiber near the zero dispersion wavelength

NASA Astrophysics Data System (ADS)

Safaei, A.; Bassi, A.; Bolorizadeh, M. A.

2018-05-01

In this report, we present a quantum theory describing the propagation of the electromagnetic radiation in a fiber in the presence of the third order dispersion coefficient. We obtained the quantum photon-polariton field, hence, we provide herein a coupled set of operator forms for the corresponding nonlinear Schrödinger equations when the third order dispersion coefficient is included. Coupled stochastic nonlinear Schrödinger equations were obtained by applying a positive P-representation that governs the propagation and interaction of quantum solitons in the presence of the third-order dispersion term. Finally, to reduce the fluctuations near solitons in the first approximation, we developed coupled stochastic linear equations.

Comment on ‘Poynting flux in the neighbourhood of a point charge in arbitrary motion and radiative power losses’

NASA Astrophysics Data System (ADS)

Rowland, David R.

2018-01-01

Based on a calculation of the Poynting vector flux in the neighbourhood of an accelerating point charge, Singal (2016 Eur. J. Phys. 37 045210) has claimed that the instantaneous rate of energy radiated by the charge differs from the Larmor formula. It is argued in this comment that Singal’s proposed formula for the radiated power is physically untenable because it predicts a negative rate of energy loss in physically realisable situations. The cause of Singal’s erroneous conclusion is identified as being a failure to realise that the bound electromagnetic field energy of an accelerating charge differs by the Schott energy from the bound field energy of a charge moving at a constant velocity equal to the current velocity of the accelerating charge. References to the salient literature are provided.

[Impact of various millimeter-range electromagnetic radiation schedules on immunological parameters in patients with respiratory sarcoidosis].

PubMed

Borisov, S B; Shpykov, A S; Terent'eva, N A

2007-01-01

The paper analyzes the impact of various millimeter-range electromagnetic radiation schedules on immunological parameters in 152 patients with new-onset respiratory sarcoidosis. It shows that the immunomodulatory effect of millimeter-range therapy depends on the treatment regimen chosen. There is evidence for the advantages of millimeter-range noise electromagnetic radiation.

[Effects of electromagnetic radiation on RAF/MEK/ERK signaling pathway in rats hippocampus].

PubMed

Zuo, Hong-yan; Wang, De-wen; Peng, Rui-yun; Wang, Shui-ming; Gao, Ya-bing; Xu, Xin-ping; Ma, Jun-Jie

2009-05-01

To study the development of changes for signaling molecules related to Raf/MEK/ERK pathway in hippocampus of rats after electromagnetic radiation, and investigate the mechanisms of radiation injury. Rats were exposed to X-HPM, S-HPM and EMP radiation source respectively, and animal model of electromagnetic radiation was established. Western blot was used to detect the expression of Raf-1, phosphorylated Raf-1 and phospholylated ERK. The expression of Raf-1 down-regulated during 6 h-14 d after radiation, most significantly at 7 d, and recovered at 28 d. There was no significant difference between the radiation groups. The expression of phosphorylated Raf-1 and phosphorylated ERK both up-regulated at 6 h and 7 d after radiation, more significantly at 6 h, and the two microwave groups were more serious for phosphorylated ERK. During 6 h-14 d after S-HPM radiation, the expression of phosphorylated Raf-1 increased continuously, but phosphorylated ERK changed wavily, 6 h and 7 d were expression peak. Raf/MEK/ERK signaling pathway participates in the hippocampus injury induced by electromagnetic radiation. The excessive activation of ERK pathway may result in the apoptosis and death of neurons, which is the important mechanism of recognition disfunction caused by electromagnetic radiation.

Non-Thermal Electromagnetic Radiation Damage to Lens Epithelium

PubMed Central

Bormusov, Elvira; P.Andley, Usha; Sharon, Naomi; Schächter, Levi; Lahav, Assaf; Dovrat, Ahuva

2008-01-01

High frequency microwave electromagnetic radiation from mobile phones and other modern devices has the potential to damage eye tissues, but its effect on the lens epithelium is unknown at present. The objective of this study was to investigate the non-thermal effects of high frequency microwave electromagnetic radiation (1.1GHz, 2.22 mW) on the eye lens epithelium in situ. Bovine lenses were incubated in organ culture at 35°C for 10-15 days. A novel computer-controlled microwave source was used to investigate the effects of microwave radiation on the lenses. 58 lenses were used in this study. The lenses were divided into four groups: (1) Control lenses incubated in organ culture for 10 to15 days. (2) Electromagnetic radiation exposure group treated with 1.1 GHz, 2.22 mW microwave radiation for 90 cycles of 50 minutes irradiation followed by 10 minutes pause and cultured up to 10 days. (3) Electromagnetic radiation exposure group treated as group 2 with 192 cycles of radiation and cultured for 15 days. (4) Lenses exposed to 39.5ºC for 2 hours 3 times with 24 hours interval after each treatment beginning on the second day of the culture and cultured for 11 days. During the culture period, lens optical quality was followed daily by a computer-operated scanning laser beam. At the end of the culture period, control and treated lenses were analyzed morphologically and by assessment of the lens epithelial ATPase activity. Exposure to 1.1 GHz, 2.22 mW microwaves caused a reversible decrease in lens optical quality accompanied by irreversible morphological and biochemical damage to the lens epithelial cell layer. The effect of the electromagnetic radiation on the lens epithelium was remarkably different from those of conductive heat. The results of this investigation showed that electromagnetic fields from microwave radiation have a negative impact on the eye lens. The lens damage by electromagnetic fields was distinctly different from that caused by conductive heat. PMID:19517034

[Saccharomyces cerevisiae as a model organism for studying the carcinogenicity of non-ionizing electromagnetic fields and radiation].

PubMed

Voĭchuk, S I

2014-01-01

Medical and biological aspects of the effects of non-ionizing electromagnetic (EM) fields and radiation on human health are the important issues that have arisen as a result of anthropogenic impact on the biosphere. Safe use of man-made sources of non-ionizing electromagnetic fields and radiation in a broad range of frequencies--static, radio-frequency and microwave--is a subject of discussions and speculations. The main problem is the lack of understanding of the mechanism(s) of reception of EMFs by living organisms. In this review we have analyzed the existing literature data regarding the effects of the electromagnetic radiation on the model eukaryotic organism--yeast Saccharomyces cerevisiae. An attempt was made to estimate the probability of induction of carcinogenesis in humans under the influence of magnetic fields and electromagnetic radiation of extremely low frequency, radio frequency and microwave ranges.

Melting heat transport of nanofluidic problem over a Riga plate with erratic thickness: Use of Keller Box scheme

NASA Astrophysics Data System (ADS)

Iqbal, Z.; Azhar, Ehtsham; Mehmood, Zaffar; Maraj, E. N.

Present article is a study of stagnation point flow over Riga plate with erratic thickness. Riga plate is an electromagnetic surface in which electrodes are assembled alternatively. This arrangement generates electromagnetic hydrodynamic behavior in the fluid flow. This is an attempt to investigate influence of melting heat, thermal radiation and viscous dissipation effects on Riga plate. A traversal electric and magnetic fields are produced by Riga plate. It causes Lorentz force parallel to wall which contributes in directing flow pattern. Physical problem is modeled and reduced nonlinear system is solved numerically. Comparative analysis is carried out between solutions obtained by Keller Box Method and shooting technique with Runge-Kutta Fehlberg method of order 5. It is noted that melting heat transfer reduces temperature distribution whereas radiation parameter upsurge it. Velocity is accelerated by modified Hartman number and Eckert number contributes in raising temperature.

Lanthanide/Actinide Opacities

NASA Astrophysics Data System (ADS)

Hungerford, Aimee; Fontes, Christopher J.

2018-06-01

Gravitational wave observations benefit from accompanying electromagnetic signals in order to accurately determine the sky positions of the sources. The ejecta of neutron star mergers are expected to produce such electromagnetic transients, called macronovae (e.g. the recent and unprecedented observation of GW170817). Characteristics of the ejecta include large velocity gradients and the presence of heavy r-process elements, which pose significant challenges to the accurate calculation of radiative opacities and radiation transport. Opacities include a dense forest of bound-bound features arising from near-neutral lanthanide and actinide elements. Here we present an overview of current theoretical opacity determinations that are used by neutron star merger light curve modelers. We will touch on atomic physics and plasma modeling codes that are used to generate these opacities, as well as the limited body of laboratory experiments that may serve as points of validation for these complex atomic physics calculations.

Vacuum electron acceleration by coherent dipole radiation

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

Troha, A.L.; Van Meter, J.R.; Landahl, E.C.

1999-07-01

The validity of the concept of laser-driven vacuum acceleration has been questioned, based on an extrapolation of the well-known Lawson-Woodward theorem, which stipulates that plane electromagnetic waves cannot accelerate charged particles in vacuum. To formally demonstrate that electrons can indeed be accelerated in vacuum by focusing or diffracting electromagnetic waves, the interaction between a point charge and coherent dipole radiation is studied in detail. The corresponding four-potential exactly satisfies both Maxwell{close_quote}s equations and the Lorentz gauge condition everywhere, and is analytically tractable. It is found that in the far-field region, where the field distribution closely approximates that of a planemore » wave, we recover the Lawson-Woodward result, while net acceleration is obtained in the near-field region. The scaling of the energy gain with wave-front curvature and wave amplitude is studied systematically. {copyright} {ital 1999} {ital The American Physical Society}« less

An All-Dielectric Coaxial Waveguide.

PubMed

Ibanescu; Fink; Fan; Thomas; Joannopoulos

2000-07-21

An all-dielectric coaxial waveguide that can overcome problems of polarization rotation and pulse broadening in the transmission of optical light is presented here. It consists of a coaxial waveguiding region with a low index of refraction, bounded by two cylindrical, dielectric, multilayer, omnidirectional reflecting mirrors. The waveguide can be designed to support a single mode whose properties are very similar to the unique transverse electromagnetic mode of a traditional metallic coaxial cable. The new mode has radial symmetry and a point of zero dispersion. Moreover, because the light is not confined by total internal reflection, the waveguide can guide light around very sharp corners.

Microwave metamaterials—from passive to digital and programmable controls of electromagnetic waves

NASA Astrophysics Data System (ADS)

Cui, Tie Jun

2017-08-01

Since 2004, my group at Southeast University has been carrying out research into microwave metamaterials, which are classified into three catagories: metamaterials based on the effective medium model, plasmonic metamaterials for spoof surface plasmon polaritons (SPPs), and coding and programmable metamaterials. For effective-medium metamaterials, we have developed a general theory to accurately describe effective permittivity and permeability in semi-analytical forms, from which we have designed and realized a three dimensional (3D) wideband ground-plane invisibility cloak, a free-space electrostatic invisibility cloak, an electromagnetic black hole, optical/radar illusions, and radially anisotropic zero-index metamaterial for omni-directional radiation and a nearly perfect power combination of source array, etc. We have also considered the engineering applications of microwave metamaterials, such as a broadband and low-loss 3D transformation-optics lens for wide-angle scanning, a 3D planar gradient-index lens for high-gain radiations, and a random metasurface for reducing radar cross sections. In the area of plasmonic metamaterials, we proposed an ultrathin, narrow, and flexible corrugated metallic strip to guide SPPs with a small bending loss and radiation loss, from which we designed and realized a series of SPP passive devices (e.g. power divider, coupler, filter, and resonator) and active devices (e.g. amplifier and duplexer). We also showed a significant feature of the ultrathin SPP waveguide in overcoming the challenge of signal integrity in traditional integrated circuits, which will help build a high-performance SPP wireless communication system. In the area of coding and programmable metamaterials, we proposed a new measure to describe a metamaterial from the viewpoint of information theory. We have illustrated theoretically and experimentally that coding metamaterials composed of digital units can be controlled by coding sequences, leading to different functions. We realised that when the digital state of a coding unit is controlled by a field programmable gate array, the programmable metamaterial, which is capable of manipulating electromagnetic waves in real time, can generate many different functions.

Electromagnetic scattering laws in Weyl systems.

PubMed

Zhou, Ming; Ying, Lei; Lu, Ling; Shi, Lei; Zi, Jian; Yu, Zongfu

2017-11-09

Wavelength determines the length scale of the cross section when electromagnetic waves are scattered by an electrically small object. The cross section diverges for resonant scattering, and diminishes for non-resonant scattering, when wavelength approaches infinity. This scattering law explains the colour of the sky as well as the strength of a mobile phone signal. We show that such wavelength scaling comes from the conical dispersion of free space at zero frequency. Emerging Weyl systems, offering similar dispersion at non-zero frequencies, lead to new laws of electromagnetic scattering that allow cross sections to be decoupled from the wavelength limit. Diverging and diminishing cross sections can be realized at any target wavelength in a Weyl system, providing the ability to tailor the strength of wave-matter interactions for radiofrequency and optical applications.

Method and apparatus for measuring electromagnetic radiation

NASA Technical Reports Server (NTRS)

Been, J. F. (Inventor)

1973-01-01

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

[Mechanisms of electromagnetic radiation damaging male reproduction].

PubMed

Xue, Lei; Chen, Hao-Yu; Wang, Shui-Ming

2012-08-01

More and more evidence from over 50 years of researches on the effects of electromagnetic radiation on male reproduction show that a certain dose of electromagnetic radiation obviously damages male reproduction, particularly the structure and function of spermatogenic cells. The mechanisms of the injury may be associated with energy dysmetabolism, lipid peroxidation, abnormal expressions of apoptosis-related genes and proteins, and DNA damage.

Digital Semaphore: Tactical Implications of QR Code Optical Signaling for Fleet Communications

DTIC Science & Technology

2013-06-01

Emissions Control (EMCON) and Hazards of Electromagnetic Radiation to Ordnance (HERO) restrict the ability for Naval Vessels to communicate using...importance of visual communications methods is brought to light by discussing emissions control, hazards of electromagnetic radiation to ordnance , and...overview of emissions restrictions including Emissions Control (EMCON) and Hazards of Electromagnetic Radiation to Ordnance (HERO). Chapter VII is

Thermally emissive sensing materials for chemical spectroscopy analysis

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

Poole, Zsolt; Ohodnicki, Paul R.

A sensor using thermally emissive materials for chemical spectroscopy analysis includes an emissive material, wherein the emissive material includes the thermally emissive materials which emit electromagnetic radiation, wherein the electromagnetic radiation is modified due to chemical composition in an environment; and a detector adapted to detect the electromagnetic radiation, wherein the electromagnetic radiation is indicative of the chemical interaction changes and hence chemical composition and/or chemical composition changes of the environment. The emissive material can be utilized with an optical fiber sensor, with the optical fiber sensor operating without the emissive material probed with a light source external to themore » material.« less

The effect of inertia on the Dirac electron, the spin Hall current and the momentum space Berry curvature

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

Chowdhury, Debashree, E-mail: debashreephys@gmail.com; Basu, B., E-mail: sribbasu@gmail.com

2013-02-15

We have studied the spin dependent force and the associated momentum space Berry curvature in an accelerating system. The results are derived by taking into consideration the non-relativistic limit of a generally covariant Dirac equation with an electromagnetic field present, where the methodology of the Foldy-Wouthuysen transformation is applied to achieve the non-relativistic limit. Spin currents appear due to the combined action of the external electric field, the crystal field and the induced inertial electric field via the total effective spin-orbit interaction. In an accelerating frame, the crucial role of momentum space Berry curvature in the spin dynamics has alsomore » been addressed from the perspective of spin Hall conductivity. For time dependent acceleration, the expression for the spin polarization has been derived. - Highlights: Black-Right-Pointing-Pointer We study the effect of acceleration on the Dirac electron in the presence of an electromagnetic field, where the acceleration induces an electric field. Black-Right-Pointing-Pointer Spin currents appear due to the total effective electric field via the total spin-orbit interaction. Black-Right-Pointing-Pointer We derive the expression for the spin dependent force and the spin Hall current, which is zero for a particular acceleration. Black-Right-Pointing-Pointer The role of the momentum space Berry curvature in an accelerating system is discussed. Black-Right-Pointing-Pointer An expression for the spin polarization for time dependent acceleration is derived.« less

Plasmonic nanoparticle chain in a light field: a resonant optical sail.

PubMed

Albaladejo, Silvia; Sáenz, Juan José; Marqués, Manuel I

2011-11-09

Optical trapping and driving of small objects has become a topic of increasing interest in multidisciplinary sciences. We propose to use a chain made of metallic nanoparticles as a resonant light sail, attached by one end point to a transparent object and propelling it by the use of electromagnetic radiation. Driving forces exerted on the chain are theoretically studied as a function of radiation's wavelength and chain's alignments with respect to the direction of radiation. Interestingly, there is a window in the frequency spectrum in which null-torque equilibrium configuration, with minimum geometric cross section, corresponds to a maximum in the driving force.

Potential of Glassy Carbon and Silicon Carbide Photonic Structures as Electromagnetic Radiation Shields for Atmospheric Re-entry

NASA Technical Reports Server (NTRS)

Komarevskiy,Nikolay; Shklover, Valery; Braginsky, Leonid; Hafner, Christian; Lawson, John W.

2012-01-01

During high-velocity atmospheric entries, space vehicles can be exposed to strong electromagnetic radiation from ionized gas in the shock layer. Glassy carbon (GC) and silicon carbide (SiC) are candidate thermal protection materials due to their high melting point and also their good thermal and mechanical properties. Based on data from shock tube experiments, a significant fraction of radiation at hypersonic entry conditions is in the frequency range from 215 to 415 THz. We propose and analyze SiC and GC photonic structures to increase the reflection of radiation in that range. For this purpose, we performed numerical optimizations of various structures using an evolutionary strategy. Among the considered structures are layered, porous, woodpile, inverse opal and guided-mode resonance structures. In order to estimate the impact of fabrication inaccuracies, the sensitivity of the reflectivity to structural imperfections is analyzed. We estimate that the reflectivity of GC photonic structures is limited to 38% in the aforementioned range, due to material absorption. However, GC material can be effective for photonic reflection of individual, strong spectral line. SiC on the other hand can be used to design a good reflector for the entire frequency range.

Potential of glassy carbon and silicon carbide photonic structures as electromagnetic radiation shields for atmospheric re-entry.

PubMed

Komarevskiy, Nikolay; Shklover, Valery; Braginsky, Leonid; Hafner, Christian; Lawson, John

2012-06-18

During high-velocity atmospheric entries, space vehicles can be exposed to strong electromagnetic radiation from ionized gas in the shock layer. Glassy carbon (GC) and silicon carbide (SiC) are candidate thermal protection materials due to their high melting point and also their good thermal and mechanical properties. Based on data from shock tube experiments, a significant fraction of radiation at hypersonic entry conditions is in the frequency range from 215 to 415 THz. We propose and analyze SiC and GC photonic structures to increase the reflection of radiation in that range. For this purpose, we performed numerical optimizations of various structures using an evolutionary strategy. Among the considered structures are layered, porous, woodpile, inverse opal and guided-mode resonance structures. In order to estimate the impact of fabrication inaccuracies, the sensitivity of the reflectivity to structural imperfections is analyzed. We estimate that the reflectivity of GC photonic structures is limited to 38% in the aforementioned range, due to material absorption. However, GC material can be effective for photonic reflection of individual, strong spectral line. SiC on the other hand can be used to design a good reflector for the entire frequency range.

Health Issues: Do Cell Phones Pose a Health Hazard?

MedlinePlus

... confused with the effects from other types of electromagnetic energy. Very high levels of electromagnetic energy, such as is found in X-rays ... light, infrared radiation (heat) and other forms of electromagnetic radiation with relatively low frequencies. While RF energy ...

Ocular cells and light: harmony or conflict?

PubMed

Jurja, Sanda; Hîncu, Mihaela; Dobrescu, Mihaela Amelia; Golu, Andreea Elena; Bălăşoiu, Andrei Theodor; Coman, Mălina

2014-01-01

Vision is based on the sensitivity of the eye to visible rays of the solar spectrum, which allows the recording and transfer of visual information by photoelectric reaction. Any electromagnetic radiation, if sufficiently intense, may cause damages in living tissues. In a changing environment, the aim of this paper is to point out the impact of light radiation on ocular cells, with its phototoxicity potential on eye tissues. In fact, faced with light and oxygen, the eye behaves like an ephemeral aggregate of unstable molecules, like a temporary crystallization threatened with entropia.

Infrared Radiative Properties of Food Materials

USDA-ARS?s Scientific Manuscript database

Precisely, infrared radiation is electromagnetic radiation whose wavelength is longer than that of visible light, but shorter than that of terahertz radiation and microwaves. The infrared portion of the electromagnetic spectrum spans roughly three orders of magnitude (750 nm to 100 µm) and has been...

Conical electromagnetic radiation flux concentrator

NASA Technical Reports Server (NTRS)

Miller, E. R.

1972-01-01

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

Measurement and analysis of radiofrequency radiations from some mobile phone base stations in Ghana.

PubMed

Amoako, J K; Fletcher, J J; Darko, E O

2009-08-01

A survey of the radiofrequency electromagnetic radiation at public access points in the vicinity of 50 cellular phone base stations has been carried out. The primary objective was to measure and analyse the electromagnetic field strength levels emitted by antennae installed and operated by the Ghana Telecommunications Company. On all the sites measurements were made using a hand-held spectrum analyser to determine the electric field level with the 900 and 1800 MHz frequency bands. The results indicated that power densities at public access points varied from as low as 0.01 microW m(-2) to as high as 10 microW m(-2) for the frequency of 900 MHz. At a transmission frequency of 1800 MHz, the variation of power densities is from 0.01 to 100 microW m(-2). The results were found to be in compliant with the International Commission on Non-ionizing Radiological Protection guidance level but were 20 times higher than the results generally obtained for such a practice elsewhere. There is therefore a need to re-assess the situation to ensure reduction in the present level as an increase in mobile phone usage is envisaged within the next few years.

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.

Universe of constant

NASA Astrophysics Data System (ADS)

Yongquan, Han

2016-10-01

The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ``gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 × 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = constant = 6 × 1075, the value of this constant is the universe, The singular point should also equal to the constant Author: hanyongquan

The change law of the universe

NASA Astrophysics Data System (ADS)

Yongquan, Han

The ideal gas state equation is not applicable to ordinary gas, it should be applied to the Electromagnetic ''gas'' that is applied to the radiation, the radiation should be the ultimate state of matter changes or initial state, the universe is filled with radiation. That is, the ideal gas equation of state is suitable for the Singular point and the universe. Maybe someone consider that, there is no vessel can accommodate radiation, it is because the Ordinary container is too small to accommodate, if the radius of your container is the distance that Light through an hour, would you still think it can't accommodates radiation? Modern scientific determinate that the radius of the universe now is about 1027 m, assuming that the universe is a sphere whose volume is approximately: V = 4.19 × 1081 cubic meters, the temperature radiation of the universe (cosmic microwave background radiation temperature of the universe, should be the closest the average temperature of the universe) T = 3.15k, radiation pressure P = 5 Ã 10-6 N / m 2, according to the law of ideal gas state equation, PV / T = 6 à 1075, the value of this constant is the universe, The singular point should also equal to the constant

The attainment of large accelerating gradients using near field synchrotron radiation

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

Decker, G.

1989-10-15

Lienard-Wiechert potentials are used to find the electromagnetic field everywhere in free space resulting from a point charge moving on a helical trajectory. The total power emitted as synchrotron radiation from a particle on a circular path is calculated. The point charge results are generalized to the case of a line charge, and formulae are presented which can easily be evaluated numerically. A useful gradient of 80 MeV/m per kA of peak driving beam current over a distance of 1 cm is calculated using two 5 MeV driving beams moving on 1 cm radius helical orbits with bunch length 1more » mm. {copyright} 1989 American Institute of Physics« less

The influence of electromagnetic pollution on living organisms: historical trends and forecasting changes.

PubMed

Redlarski, Grzegorz; Lewczuk, Bogdan; Żak, Arkadiusz; Koncicki, Andrzej; Krawczuk, Marek; Piechocki, Janusz; Jakubiuk, Kazimierz; Tojza, Piotr; Jaworski, Jacek; Ambroziak, Dominik; Skarbek, Łukasz; Gradolewski, Dawid

2015-01-01

Current technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. In many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. The harm caused by this pollution is still open to question since there is no clear and definitive evidence of its negative influence on humans. This is despite the fact that extremely low frequency electromagnetic fields were classified as potentially carcinogenic. For these reasons, in recent decades a significant growth can be observed in scientific research in order to understand the influence of electromagnetic radiation on living organisms. However, for this type of research the appropriate selection of relevant model organisms is of great importance. It should be noted here that the great majority of scientific research papers published in this field concerned various tests performed on mammals, practically neglecting lower organisms. In that context the objective of this paper is to systematise our knowledge in this area, in which the influence of electromagnetic radiation on lower organisms was investigated, including bacteria, E. coli and B. subtilis, nematode, Caenorhabditis elegans, land snail, Helix pomatia, common fruit fly, Drosophila melanogaster, and clawed frog, Xenopus laevis.

The Influence of Electromagnetic Pollution on Living Organisms: Historical Trends and Forecasting Changes

PubMed Central

Żak, Arkadiusz; Koncicki, Andrzej; Piechocki, Janusz; Jakubiuk, Kazimierz; Tojza, Piotr; Jaworski, Jacek; Ambroziak, Dominik; Skarbek, Łukasz

2015-01-01

Current technologies have become a source of omnipresent electromagnetic pollution from generated electromagnetic fields and resulting electromagnetic radiation. In many cases this pollution is much stronger than any natural sources of electromagnetic fields or radiation. The harm caused by this pollution is still open to question since there is no clear and definitive evidence of its negative influence on humans. This is despite the fact that extremely low frequency electromagnetic fields were classified as potentially carcinogenic. For these reasons, in recent decades a significant growth can be observed in scientific research in order to understand the influence of electromagnetic radiation on living organisms. However, for this type of research the appropriate selection of relevant model organisms is of great importance. It should be noted here that the great majority of scientific research papers published in this field concerned various tests performed on mammals, practically neglecting lower organisms. In that context the objective of this paper is to systematise our knowledge in this area, in which the influence of electromagnetic radiation on lower organisms was investigated, including bacteria, E. coli and B. subtilis, nematode, Caenorhabditis elegans, land snail, Helix pomatia, common fruit fly, Drosophila melanogaster, and clawed frog, Xenopus laevis. PMID:25811025

All-dielectric metamaterials

NASA Astrophysics Data System (ADS)

Jahani, Saman; Jacob, Zubin

2016-01-01

The ideal material for nanophotonic applications will have a large refractive index at optical frequencies, respond to both the electric and magnetic fields of light, support large optical chirality and anisotropy, confine and guide light at the nanoscale, and be able to modify the phase and amplitude of incoming radiation in a fraction of a wavelength. Artificial electromagnetic media, or metamaterials, based on metallic or polar dielectric nanostructures can provide many of these properties by coupling light to free electrons (plasmons) or phonons (phonon polaritons), respectively, but at the inevitable cost of significant energy dissipation and reduced device efficiency. Recently, however, there has been a shift in the approach to nanophotonics. Low-loss electromagnetic responses covering all four quadrants of possible permittivities and permeabilities have been achieved using completely transparent and high-refractive-index dielectric building blocks. Moreover, an emerging class of all-dielectric metamaterials consisting of anisotropic crystals has been shown to support large refractive index contrast between orthogonal polarizations of light. These advances have revived the exciting prospect of integrating exotic electromagnetic effects in practical photonic devices, to achieve, for example, ultrathin and efficient optical elements, and realize the long-standing goal of subdiffraction confinement and guiding of light without metals. In this Review, we present a broad outline of the whole range of electromagnetic effects observed using all-dielectric metamaterials: high-refractive-index nanoresonators, metasurfaces, zero-index metamaterials and anisotropic metamaterials. Finally, we discuss current challenges and future goals for the field at the intersection with quantum, thermal and silicon photonics, as well as biomimetic metasurfaces.

Fluctuation of a Piston in Vacuum Induced by Thermal Radiation Pressure

NASA Astrophysics Data System (ADS)

Inui, Norio

2017-10-01

We consider the displacement of a piston dividing a vacuum cavity at a finite temperature T induced by fluctuations in the thermal radiation pressure. The correlation function of the thermal radiation pressure is calculated using the theoretical framework developed by Barton, which was first applied to the fluctuation of the Casimir force at absolute zero. We show that the variance of the radiation pressure at a fixed point is proportional to T8 and evaluate the mean square displacement for a piston with a small cross section in a characteristic correlation timescale ħ/(kBT). At room temperature, the contribution of the thermal radiation to the fluctuation is larger than that of the vacuum fluctuation.

Electromagnetic inhibition of high frequency thermal bonding machine

NASA Astrophysics Data System (ADS)

He, Hong; Zhang, Qing-qing; Li, Hang; Zhang, Da-jian; Hou, Ming-feng; Zhu, Xian-wei

2011-12-01

The traditional high frequency thermal bonding machine had serious radiation problems at dominant frequency, two times frequency and three times frequency. Combining with its working principle, the problems of electromagnetic compatibility were studied, three following measures were adopted: 1.At the head part of the high frequency thermal bonding machine, resonant circuit attenuator was designed. The notch groove and reaction field can make the radiation being undermined or absorbed; 2.The electromagnetic radiation shielding was made for the high frequency copper power feeder; 3.Redesigned the high-frequency oscillator circuit to reduce the output of harmonic oscillator. The test results showed that these measures can make the output according with the national standard of electromagnetic compatibility (GB4824-2004-2A), the problems of electromagnetic radiation leakage can be solved, and good social, environmental and economic benefits would be brought.

Discussion and analytical test for inclusion of advanced field and boundary condition in theory of free electron lasers

NASA Astrophysics Data System (ADS)

Niknejadi, Pardis; Madey, John M. J.

2017-09-01

By the covariant statement of the distance in space-time separating transmitter and receivers, the emission and absorption of the retarded and advanced waves are all simultaneous. In other words, for signals carried on electromagnetic waves (advanced or retarded) the invariant interval (cdt) 2 -dr2 between the emission of a wave and it's absorption at the non-reflecting boundary is always identically zero. Utilizing this principle, we have previously explained the advantages of including the coherent radiation reaction force as a part of the solution to the boundary value problem for FELs that radiate into "free space" (Self Amplified Spontaneous Emission (SASE) FELs) and discussed how the advanced field of the absorber can interact with the radiating particles at the time of emission. Here we present an analytical test which verifies that a multilayer mirror can act as a band pass filter and can contribute to microbunching in the electron beam. Here we will discuss motivation, conditions and requirements, and method for testing this effect.

RF waves - Measuring their energy (dBm) in three points into Baia Mare, Romania

NASA Astrophysics Data System (ADS)

Pop-Vǎdean, A.; Pop, P. P.; Barz, C.; Lung, C.

2016-02-01

For the general public - and even for people with a science education - knowing to be subject to Radio Frequency (RF) radiation may arouse a feeling of uneasiness or even fear. Those feelings are instigated by the fact that you cannot see, hear, smell or feel RF radiation. Furthermore, the term „radiation” in itself has become very sensitive from the moment that the hazardous health effects of excessive radioactive decay (ionizing radiation) have become apparent. Media announcements of mostly unconfirmed scientific studies add to the feeling of uneasiness. So, naturally, whenever a new Global System of Mobile communications (GSM) base station is installed in an urban environment, the people living in the neighborhood may get worried. The same applies when we propose to use RF radiation for powering wireless sensors in office and home spaces using harvesting energy sistem (HE).In this paper we determine if the electromagnetic field intensity values, measured at certain points, respect the limits set by law, the protection against risks to human health.

Non-astigmatic imaging with matched pairs of spherically bent reflectors

DOEpatents

Bitter, Manfred Ludwig [Princeton, NJ; Hill, Kenneth Wayne [Plainsboro, NJ; Scott, Steven Douglas [Wellesley, MA; Feder, Russell [Newton, PA; Ko, Jinseok [Cambridge, MA; Rice, John E [N. Billerica, MA; Ince-Cushman, Alexander Charles [New York, NY; Jones, Frank [Manalapan, NJ

2012-07-10

Arrangements for the point-to-point imaging of a broad spectrum of electromagnetic radiation and ultrasound at large angles of incidence employ matched pairs of spherically bent reflectors to eliminate astigmatic imaging errors. Matched pairs of spherically bent crystals or spherically bent multi-layers are used for X-rays and EUV radiation; and matched pairs of spherically bent mirrors that are appropriate for the type of radiation are used with microwaves, infrared and visible light, or ultrasound. The arrangements encompass the two cases, where the Bragg angle--the complement to the angle of incidence in optics--is between 45.degree. and 90.degree. on both crystals/mirrors or between 0.degree. and 45.degree. on the first crystal/mirror and between 45.degree. and 90.degree. on the second crystal/mirror, where the angles of convergence and divergence are equal. For x-rays and EUV radiation, also the Bragg condition is satisfied on both spherically bent crystals/multi-layers.

Optically powered active sensing system for Internet Of Things

NASA Astrophysics Data System (ADS)

Gao, Chen; Wang, Jin; Yin, Long; Yang, Jing; Jiang, Jian; Wan, Hongdan

2014-10-01

Internet Of Things (IOT) drives a significant increase in the extent and type of sensing technology and equipment. Sensors, instrumentation, control electronics, data logging and transmission units comprising such sensing systems will all require to be powered. Conventionally, electrical powering is supplied by batteries or/and electric power cables. The power supply by batteries usually has a limited lifetime, while the electric power cables are susceptible to electromagnetic interference. In fact, the electromagnetic interference is the key issue limiting the power supply in the strong electromagnetic radiation area and other extreme environments. The novel alternative method of power supply is power over fiber (PoF) technique. As fibers are used as power supply lines instead, the delivery of the power is inherently immune to electromagnetic radiation, and avoids cumbersome shielding of power lines. Such a safer power supply mode would be a promising candidate for applications in IOT. In this work, we built up optically powered active sensing system, supplying uninterrupted power for the remote active sensors and communication modules. Also, we proposed a novel maximum power point tracking technique for photovoltaic power convertors. In our system, the actual output efficiency greater than 40% within 1W laser power. After 1km fiber transmission and opto-electric power conversion, a stable electric power of 210mW was obtained, which is sufficient for operating an active sensing system.

Sandia National Laboratories: Exceptional Service in the National Interest

Science.gov Websites

Electromagnetics Engineering Science Geoscience Materials Science Nanodevices & Microsystems Radiation Effects Electromagnetics Engineering Science Geoscience Materials Science Nanodevices & Microsystems Radiation Effects Geoscience Materials Science Nanodevices & Microsystems Radiation Effects & High Energy Density

Gravitational Stokes parameters. [for electromagnetic and gravitational radiation in relativity

NASA Technical Reports Server (NTRS)

Anile, A. M.; Breuer, R. A.

1974-01-01

The electromagnetic and gravitational Stokes parameters are defined in the general theory of relativity. The general-relativistic equation of radiative transfer for polarized radiation is then derived in terms of the Stokes parameters for both high-frequency electromagnetic and gravitational waves. The concept of Stokes parameters is generalized for the most general class of metric theories of gravity, where six (instead of two) independent states of polarization are present.

Effects of low-intensity ultrahigh frequency electromagnetic radiation on inflammatory processes.

PubMed

Lushnikov, K V; Shumilina, Yu V; Yakushina, V S; Gapeev, A B; Sadovnikov, V B; Chemeris, N K

2004-04-01

Low-intensity ultrahigh frequency electromagnetic radiation (42 GHz, 100 microW/cm(2)) reduces the severity of inflammation and inhibits production of active oxygen forms by inflammatory exudate neutrophils only in mice with inflammatory process. These data suggest that some therapeutic effects of electromagnetic radiation can be explained by its antiinflammatory effect which is realized via modulation of functional activity of neutrophils in the focus of inflammation.

[Morphological structure of rat epiphysis exposed to electromagnetic radiation from communication devices].

PubMed

Yashchenko, S G; Rybalko, S Yu

Pineal gland is one of the most important components of homeostasis - the supporting system of the body. It participates in the launch of stress responses, restriction of their development, prevention of adverse effects on the body. There was proved an impact of electromagnetic radiation on the epiphysis. However, morphological changes in the epiphysis under exposure to electromagnetic radiation of modern communication devices are studied not sufficiently. For the time present the population is daily exposed to electromagnetic radiation, including local irradiation on the brain. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. These date determined the task of this research - the study of the structure of rat pineal gland under the exposure to electromagnetic radiation from personal computers and mobile phones. Performed transmission electron microscopy revealed signs of degeneration of dark and light pinealocytes. These signs were manifested in the development of a complex of general and specific morphological changes. There was revealed the appearance of signs of aging and depletion transmission electron microscopy both in light and dark pinealocytes. These signs were manifested in the accumulation of lipofuscin granules and electron-dense "brain sand", the disappearance of nucleoli, cytoplasm vacuolization and mitochondrial cristae enlightenment.

Study of electromagnetic radiation pollution in Jalandhar city, India

NASA Astrophysics Data System (ADS)

Basandrai, D.; Dhami, A. K.; Bedi, R. K.; Khan, S. A.

2017-07-01

Environment pollution from electromagnetic radiations emitted from cell phone towers is a new kind of health hazard, which has increase the public concern regarding the health implications of electromagnetic radiations on humans and animals. Long term consequences of these radiations are still unknown. So it become important to measure and maps the electromagnetic radiation level to analyze potential risk. The present study has been taken to estimate the RF pollution by measuring radiation power densities level near school, hospitals and old age home of Jalandhar City, India. The radiation exposure was measured using a handheld portable electrosmog meter. Results were compared with the safety guidelines issued by ICNIRP (International commission on non ionizing radiation protection) and Bio-initiative report, 2012. It has been found that the radiation exposure level in terms of power densities and corresponding specific absorption rate (SAR) are much below than ICNIRP guidelines for all schools, hospitals and old age home. But in the case of 3 schools, the results are quite alarming where the power density and SAR was found to be 79.6% and 4%, respectively higher in comparisons with safe biological limit.

A Discussion about Ionising and Non-Ionising Radiation and the Critical Issue of Mobile Phones

ERIC Educational Resources Information Center

Kontomaris, Stylianos-Vasileios; Malamou, Anna

2018-01-01

Electromagnetic radiation is one of the most important issues affecting peoples' lives today. The misunderstanding of students and the general population of the effects of electromagnetic radiation is a problem which must be eliminated. Thus, a discussion about ionising and non-ionising radiation focusing on the crucial issue of radiation emitted…

[Effects of electromagnetic radiation on health and immune function of operators].

PubMed

Li, Yan-zhong; Chen, Shao-hua; Zhao, Ke-fu; Gui, Yun; Fang, Si-xin; Xu, Ying; Ma, Zi-jian

2013-08-01

To investigate the effects of electromagnetic radiation on the physiological indices and immune function of operators. The general conditions and electromagnetic radiation awareness rate of 205 operators under electromagnetic radiation were evaluated using a self-designed questionnaire. Physical examination, electrocardiography, and routine urine test were performed in these operators. Peripheral blood was collected from the operators under electromagnetic radiation for blood cell counting and biochemical testing, and their peripheral blood lymphocytes were cultured for determination of chromosomal aberrant frequency and micronucleus frequency. The data from these operators (exposure group) were compared with those of 95 ordinary individuals (control group). The chief complaint of giddiness, tiredness, dizziness, and amnesia showed significant differences between the exposure group and control group (P < 0.01), and the difference in headache became larger with an increase in working years. The awareness rate of electromagnetic radiation damage was significantly higher in the exposure group than in the control group. The difference in bradycardia was significant between the two groups (P <0.01), and the incidence was higher with longer working years. Significant differences between the two groups were also found in the numbers of individuals with elevated alanine aminotransferase, total bilirubin, and direct bilirubin (P < 0.01), populations with increased lymphocyte ratio and decreased neutrophil ratio (P < 0.01), populations with positive occult blood, urobilinogen, and bilirubin tests, and the number of individuals with increased micronucleus frequency of cultured peripheral blood lymphocytes (P < 0.01). In addition, the exposure group had significantly increased complement C3 and C4 (P < 0.01), significantly increased IgG (P < 0.05), and significantly decreased IgM (P < 0.01), as compared with the control group. Electromagnetic radiation may lead to the changes in physiological indices, genetic effects, and immune function and affect the health and immune function in operators. The adverse effects are increased as the working years increase. So it is important to strengthen occupational protection of operators under electromagnetic radiation.

Thermo-optical Modelling of Laser Matter Interactions in Selective Laser Melting Processes.

NASA Astrophysics Data System (ADS)

Vinnakota, Raj; Genov, Dentcho

Selective laser melting (SLM) is one of the promising advanced manufacturing techniques, which is providing an ideal platform to manufacture components with zero geometric constraints. Coupling the electromagnetic and thermodynamic processes involved in the SLM, and developing the comprehensive theoretical model of the same is of great importance since it can provide significant improvements in the printing processes by revealing the optimal parametric space related to applied laser power, scan velocity, powder material, layer thickness and porosity. Here, we present a self-consistent Thermo-optical model which simultaneously solves the Maxwell's and the heat transfer equations and provides an insight into the electromagnetic energy released in the powder-beds and the concurrent thermodynamics of the particles temperature rise and onset of melting. The numerical calculations are compared with developed analytical model of the SLM process providing insight into the dynamics between laser facilitated Joule heating and radiation mitigated rise in temperature. These results provide guidelines toward improved energy efficiency and optimization of the SLM process scan rates. The current work is funded by the NSF EPSCoR CIMM project under award #OIA-1541079.

Electromagnetic radiation and nonlinear energy flow in an electron beam-plasma system

NASA Technical Reports Server (NTRS)

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

1985-01-01

It is shown that the unstable electron-plasma waves of a beam-plasma system can generate electromagnetic radiation in a uniform plasma. The generation mechanism is a scattering of the unstable electron plasma waves off ion-acoustic waves, producing electromagnetic waves whose frequency is near the local plasma frequency. The wave vector and frequency matching conditions of the three-wave mode coupling are experimentally verified. The electromagnetic radiation is observed to be polarized with the electric field parallel to the beam direction, and its source region is shown to be localized to the unstable plasma wave region. The frequency spectrum shows negligible intensity near the second harmonic of the plasma frequency. These results suggest that the observed electromagnetic radiation of type III solar bursts may be generated near the local plasma frequency and observed downstream where the wave frequency is near the harmonic of the plasma frequency.

Illusion optics: Optically transforming the nature and the location of electromagnetic emissions

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

Yi, Jianjia; Tichit, Paul-Henri; Burokur, Shah Nawaz, E-mail: shah-nawaz.burokur@u-psud.fr

Complex electromagnetic structures can be designed by using the powerful concept of transformation electromagnetics. In this study, we define a spatial coordinate transformation that shows the possibility of designing a device capable of producing an illusion on an antenna radiation pattern. Indeed, by compressing the space containing a radiating element, we show that it is able to change the radiation pattern and to make the radiation location appear outside the latter space. Both continuous and discretized models with calculated electromagnetic parameter values are presented. A reduction of the electromagnetic material parameters is also proposed for a possible physical fabrication ofmore » the device with achievable values of permittivity and permeability that can be obtained from existing well-known metamaterials. Following that, the design of the proposed antenna using a layered metamaterial is presented. Full wave numerical simulations using Finite Element Method are performed to demonstrate the performances of such a device.« less

Zero-power infrared digitizers based on plasmonically enhanced micromechanical photoswitches

NASA Astrophysics Data System (ADS)

Qian, Zhenyun; Kang, Sungho; Rajaram, Vageeswar; Cassella, Cristian; McGruer, Nicol E.; Rinaldi, Matteo

2017-10-01

State-of-the-art sensors use active electronics to detect and discriminate light, sound, vibration and other signals. They consume power constantly, even when there is no relevant data to be detected, which limits their lifetime and results in high costs of deployment and maintenance for unattended sensor networks. Here we propose a device concept that fundamentally breaks this paradigm—the sensors remain dormant with near-zero power consumption until awakened by a specific physical signature associated with an event of interest. In particular, we demonstrate infrared digitizing sensors that consist of plasmonically enhanced micromechanical photoswitches (PMPs) that selectively harvest the impinging electromagnetic energy in design-defined spectral bands of interest, and use it to create mechanically a conducting channel between two electrical contacts, without the need for any additional power source. Our zero-power digitizing sensor prototypes produce a digitized output bit (that is, a large and sharp off-to-on state transition with an on/off conductance ratio >1012 and subthreshold slope >9 dec nW-1) when exposed to infrared radiation in a specific narrow spectral band (∼900 nm bandwidth in the mid-infrared) with the intensity above a power threshold of only ∼500 nW, which is not achievable with any existing photoswitch technologies.

Characteristics of electromagnetic interference generated during discharge of Mylar samples. [spacecraft-environment interaction simulation

NASA Technical Reports Server (NTRS)

Leung, P. L.

1984-01-01

This paper discusses the measurements of the electromagnetic interference (EMI) generated during discharges of Mylar samples. The two components of EMI, the conducted emission and the radiated emission, are characterized by the replacement current and the radiated RF spectrum respectively. The measured radiated RF spectra reveal important information on the source of the electromagnetic radiation. The possible sources are the replacement current pulse and the discharged generated plasma. The scaling of the amplitudes of the EMI, as a function of the area of the test sample, is also discussed.

Electromagnetic Radiation in the Atmosphere Generated by Excess Negative Charge in a Nuclear-Electromagnetic Cascade

NASA Astrophysics Data System (ADS)

Malyshevsky, V. S.; Fomin, G. V.

2017-01-01

On the basis of the analytical model "PARMA" (PHITS-based Analytical Radiation Model in the Atmosphere), developed to model particle fluxes of secondary cosmic radiation in the Earth's atmosphere, we have calculated the characteristics of radio waves emitted by excess negative charge in an electromagnetic cascade. The results may be of use in an analysis of experimental data on radio emission of electron-photon showers in the atmosphere.

Environmental Assessment for AFRL/RY Research & Development Activities & Area B Laser Test Area, Wright-Patterson AFB, Ohio

DTIC Science & Technology

2008-10-01

732) 866-2821 Hazards of Electromagnetic Radiation to Ordnance ( HERO ) Mr. Charles Denham/Rick Magrogan Naval Surface Warfare Center, Dahlgren...with a lightning strike; thus the requirements of paragraph C7.4.1 of reference (b) are met. (4) There are no electromagnetic radiation hazards to...the other hazardous material requirements of 49 CFR. This includes, but is not limited to, the packaging, electromagnetic radiation , and

Effects of Millimeter-Wave Electromagnetic Radiation on the Experimental Model of Migraine.

PubMed

Sivachenko, I B; Medvedev, D S; Molodtsova, I D; Panteleev, S S; Sokolov, A Yu; Lyubashina, O A

2016-02-01

Effects of millimeter-wave electromagnetic radiation (40 GHz frequency, 0.01 mW power) on the spontaneous fi ring of convergent neurons of the spinal trigeminal nucleus and their responses to electrical stimulation of the dura mater were studied in neurophysiological experiments on rats. Irradiation of the area of cutaneous receptive fields of spinal trigeminal nucleus reversibly inhibited both spontaneous discharges and activity induced by electrical stimulation of the dura mater. The second and third exposures to electromagnetic radiation with an interval of 10 min were ineffective. These results suggest that suppression of neuronal excitability in the spinal trigeminal ganglion can be a mechanism of the anti-migraine effects of electromagnetic radiation observed in clinical practice.

Distinguishing non-resonant four-wave-mixing noise in coherent stokes and anti-stokes Raman scattering

NASA Technical Reports Server (NTRS)

Marks, Daniel L. (Inventor); Boppart, Stephen A. (Inventor)

2009-01-01

A method of examining a sample comprises exposing the sample to a pump pulse of electromagnetic radiation for a first period of time, exposing the sample to a stimulant pulse of electromagnetic radiation for a second period of time which overlaps in time with at least a portion of the first exposing, to produce a signal pulse of electromagnetic radiation for a third period of time, and interfering the signal pulse with a reference pulse of electromagnetic radiation, to determine which portions of the signal pulse were produced during the exposing of the sample to the stimulant pulse. The first and third periods of time are each greater than the second period of time.

Biological Effects of Nonionizing Electromagnetic Radiation. Volume IV. Number 3.

DTIC Science & Technology

1980-03-01

lines that produce EMR. perimental evidence on human health effects due to electromagnetic field exposures from high-voltage transmission lines is...1311, Mrch YOW that a permissible occupational exposure level to The biologic effects of electromagnetic fields on MW and RF radiation of 500 PW/cm 2...along with the principal physical param- eters of exposure . 6402 REGULATING POSSIBLE HEALTH EFFECTS FROM AC TRANSMISSION LINE ELECTROMAGNETIC FIELDS

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

Method for plasma formation for extreme ultraviolet lithography-theta pinch

DOEpatents

Hassanein, Ahmed [Naperville, IL; Konkashbaev, Isak [Bolingbrook, IL; Rice, Bryan [Hillsboro, OR

2007-02-20

A device and method for generating extremely short-wave ultraviolet electromagnetic wave, utilizing a theta pinch plasma generator to produce electromagnetic radiation in the range of 10 to 20 nm. The device comprises an axially aligned open-ended pinch chamber defining a plasma zone adapted to contain a plasma generating gas within the plasma zone; a means for generating a magnetic field radially outward of the open-ended pinch chamber to produce a discharge plasma from the plasma generating gas, thereby producing a electromagnetic wave in the extreme ultraviolet range; a collecting means in optical communication with the pinch chamber to collect the electromagnetic radiation; and focusing means in optical communication with the collecting means to concentrate the electromagnetic radiation.

A discussion about ionising and non-ionising radiation and the critical issue of mobile phones

NASA Astrophysics Data System (ADS)

Kontomaris, Stylianos-Vasileios; Malamou, Anna

2018-01-01

Electromagnetic radiation is one of the most important issues affecting peoples’ lives today. The misunderstanding of students and the general population of the effects of electromagnetic radiation is a problem which must be eliminated. Thus, a discussion about ionising and non-ionising radiation focusing on the crucial issue of radiation emitted by mobile phones is presented.

48 CFR 252.235-7003 - Frequency authorization.

Code of Federal Regulations, 2014 CFR

2014-10-01

... characteristics of the proposed electromagnetic radiating device to the Contracting Officer during the initial... Contractor shall provide the technical operating characteristics of the proposed electromagnetic radiating...

Generation of nonthermal continuum radiation in the magnetosphere

NASA Technical Reports Server (NTRS)

Okuda, H.; Chance, M. S.; Ashour-Abdalla, M.; Kurth, W. S.

1982-01-01

Generation of electromagnetic continuum radiation from electrostatic fluctuations near the upper hybrid resonance frequency has been calculated by using cold plasma theory in an inhomogeneous plasma near the plasmapause. It is shown that both the polarization and the amplitude of electromagnetic radiation are in good quantitative agreement with spacecraft observations for nonthermal continuum radiation.

Multifluid cosmology: An illustration of fundamental principles

NASA Astrophysics Data System (ADS)

Comer, G. L.; Peter, Patrick; Andersson, N.

2012-05-01

Our current understanding of the Universe depends on the interplay of several distinct matter components, which interact mainly through gravity, and electromagnetic radiation. The nature of the different components, and possible interactions, tends to be based on the notion of coupled perfect fluids (or scalar fields). This approach is somewhat naive, especially if one wants to be able to consider issues involving heat flow, dissipative mechanisms, or Bose-Einstein condensation of dark matter. We argue that a more natural starting point would be the multipurpose variational relativistic multifluid system that has so far mainly been applied to neutron star astrophysics. As an illustration of the fundamental principles involved, we develop the formalism for determining the nonlinear cosmological solutions to the Einstein equations for a general relativistic two-fluid model for a coupled system of matter (nonzero rest mass) and radiation (zero rest mass). The two fluids are allowed to interpenetrate and exhibit a relative flow with respect to each other, implying, in general, an anisotropic Universe. We use initial conditions such that the massless fluid flux dominates early on so that the situation is effectively that of a single-fluid and one has the usual Friedmann-Lemaître-Robertson-Walker spacetime. We find that there is a Bianchi I transition epoch out of which the matter flux dominates. The situation is then effectively that of a single fluid and the spacetime evolves towards the Friedmann-Lemaître-Robertson-Walker form. Such a transition opens up the possibility of imprinting observable consequences at the specific scale corresponding to the transition time.

On the Transport and Radiative Properties of Plasmas with Small-Scale Electromagnetic Fluctuations

NASA Astrophysics Data System (ADS)

Keenan, Brett D.

Plasmas with sub-Larmor-scale ("small-scale") electromagnetic fluctuations are a feature of a wide variety of high-energy-density environments, and are essential to the description of many astrophysical/laboratory plasma phenomena. Radiation from particles, whether they be relativistic or non-relativistic, moving through small-scale electromagnetic turbulence has spectral characteristics distinct from both synchrotron and cyclotron radiation. The radiation, carrying information on the statistical properties of the turbulence, is also intimately related to the particle diffusive transport. We investigate, both theoretically and numerically, the transport of non-relativistic and transrelativistic particles in plasmas with high-amplitude isotropic sub-Larmor-scale magnetic turbulence---both with and without a mean field component---and its relation to the spectra of radiation simultaneously produced by these particles. Furthermore, the transport of particles through small-scale electromagnetic turbulence---under certain conditions---resembles the random transport of particles---via Coulomb collisions---in collisional plasmas. The pitch-angle diffusion coefficient, which acts as an effective "collision" frequency, may be substantial in these, otherwise, collisionless environments. We show that this effect, colloquially referred to as the plasma "quasi-collisionality", may radically alter the expected radiative transport properties of candidate plasmas. We argue that the modified magneto-optic effects in these plasmas provide an attractive, novel, diagnostic tool for the exploration and characterization of small-scale electromagnetic turbulence. Lastly, we speculate upon the manner in which quasi-collisions may affect inertial confinement fusion (ICF), and other laser-plasma experiments. Finally, we show that mildly relativistic jitter radiation, from laser-produced plasmas, may offer insight into the underlying electromagnetic turbulence. Here we investigate the prospects for, and demonstrate the feasibility of, such direct radiative diagnostics for mildly relativistic, solid-density laser plasmas produced in lab experiments. In effect, we demonstrate how the diffusive and radiative properties of plasmas with small-scale, turbulent, electromagnetic fluctuations may serve as a powerful tool for the diagnosis of laboratory, astrophysical, and space plasmas.

Spectral singularities of complex scattering potentials and infinite reflection and transmission coefficients at real energies.

PubMed

Mostafazadeh, Ali

2009-06-05

Spectral singularities are spectral points that spoil the completeness of the eigenfunctions of certain non-Hermitian Hamiltonian operators. We identify spectral singularities of complex scattering potentials with the real energies at which the reflection and transmission coefficients tend to infinity, i.e., they correspond to resonances having a zero width. We show that a waveguide modeled using such a potential operates like a resonator at the frequencies of spectral singularities. As a concrete example, we explore the spectral singularities of an imaginary PT-symmetric barrier potential and demonstrate the above resonance phenomenon for a certain electromagnetic waveguide.

Spectral Singularities of Complex Scattering Potentials and Infinite Reflection and Transmission Coefficients at Real Energies

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

Mostafazadeh, Ali

2009-06-05

Spectral singularities are spectral points that spoil the completeness of the eigenfunctions of certain non-Hermitian Hamiltonian operators. We identify spectral singularities of complex scattering potentials with the real energies at which the reflection and transmission coefficients tend to infinity, i.e., they correspond to resonances having a zero width. We show that a waveguide modeled using such a potential operates like a resonator at the frequencies of spectral singularities. As a concrete example, we explore the spectral singularities of an imaginary PT-symmetric barrier potential and demonstrate the above resonance phenomenon for a certain electromagnetic waveguide.

Thread bonds in molecules

NASA Astrophysics Data System (ADS)

Ivlev, B.

2017-07-01

Unusual chemical bonds are proposed. Each bond is characterized by the thread of a small radius, 10-11 cm, extended between two nuclei in a molecule. An analogue of a potential well, of the depth of MeV scale, is formed within the thread. This occurs due to the local reduction of zero point electromagnetic energy. This is similar to formation of the Casimir well. The electron-photon interaction only is not sufficient for formation of thread state. The mechanism of electron mass generation is involved in the close vicinity, 10-16 cm, of the thread. Thread bonds are stable and cannot be created or destructed in chemical or optical processes.

Higher Dimensional Spacetimes for Visualizing and Modeling Subluminal, Luminal and Superluminal Flight

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

Froning, H. David; Meholic, Gregory V.

2010-01-28

This paper briefly explores higher dimensional spacetimes that extend Meholic's visualizable, fluidic views of: subluminal-luminal-superluminal flight; gravity, inertia, light quanta, and electromagnetism from 2-D to 3-D representations. Although 3-D representations have the potential to better model features of Meholic's most fundamental entities (Transluminal Energy Quantum) and of the zero-point quantum vacuum that pervades all space, the more complex 3-D representations loose some of the clarity of Meholic's 2-D representations of subluminal and superlumimal realms. So, much new work would be needed to replace Meholic's 2-D views of reality with 3-D ones.

One-dimensional "atom" with zero-range potential perturbed by finite sequence of zero-duration laser pulses

NASA Astrophysics Data System (ADS)

Gusev, A. A.; Chuluunbaatar, O.; Popov, Yu. V.; Vinitsky, S. I.; Derbov, V. L.; Lovetskiy, K. P.

2018-04-01

The exactly soluble model of a train of zero-duration electromagnetic pulses interacting with a 1D atom with short-range interaction potential modelled by a δ-function is considered. The model is related to the up-to-date laser techniques providing the duration of pulses as short as a few attoseconds and the intensities higher than 1014 W/cm2.

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

Research on radiation characteristic of plasma antenna through FDTD method.

PubMed

Zhou, Jianming; Fang, Jingjing; Lu, Qiuyuan; Liu, Fan

2014-01-01

The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD) approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML). Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic.

An experimental test of the 'transmission-line model' of electromagnetic radiation from triggered lightning return strokes

NASA Technical Reports Server (NTRS)

Willett, J. C.; Idone, V. P.; Orville, R. E.; Leteinturier, C.; Eybert-Berard, A.

1988-01-01

Peak currents, two-dimensional average propagation speeds, and electric field waveforms for a number of subsequent return strikes in rocket-triggered lightning flashes were measured in order to test the 'transmission-line model' of return-stroke radiation of Uman and McLain (1970). Reasonable agreement is found between the propagation speeds measured with the streak camera and those deduced from the transmission-line model. A modification of the model is proposed in which two wave fronts travel upward and downward away from a junction point a short distance above the ground.

An experimental test of the 'transmission-line model' of electromagnetic radiation from triggered lightning return strokes

NASA Astrophysics Data System (ADS)

Willett, J. C.; Idone, V. P.; Orville, R. E.; Leteinturier, C.; Eybert-Berard, A.

1988-04-01

Peak currents, two-dimensional average propagation speeds, and electric field waveforms for a number of subsequent return strikes in rocket-triggered lightning flashes were measured in order to test the 'transmission-line model' of return-stroke radiation of Uman and McLain (1970). Reasonable agreement is found between the propagation speeds measured with the streak camera and those deduced from the transmission-line model. A modification of the model is proposed in which two wave fronts travel upward and downward away from a junction point a short distance above the ground.

Application of a zero-latency whitening filter to compact binary coalescence gravitational-wave searches

NASA Astrophysics Data System (ADS)

Tsukada, Leo; Cannon, Kipp; Hanna, Chad; Keppel, Drew; Meacher, Duncan; Messick, Cody

2018-05-01

Joint electromagnetic and gravitational-wave (GW) observation is a major goal of both the GW astronomy and electromagnetic astronomy communities for the coming decade. One way to accomplish this goal is to direct follow-up of GW candidates. Prompt electromagnetic emission may fade quickly, therefore it is desirable to have GW detection happen as quickly as possible. A leading source of latency in GW detection is the whitening of the data. We examine the performance of a zero-latency whitening filter in a detection pipeline for compact binary coalescence (CBC) GW signals. We find that the filter reproduces signal-to-noise ratio (SNR) sufficiently consistent with the results of the original high-latency and phase-preserving filter for both noise and artificial GW signals (called "injections"). Additionally, we demonstrate that these two whitening filters show excellent agreement in χ2 value, a discriminator for GW signals.

49 CFR 173.60 - General packaging requirements for explosives.

Code of Federal Regulations, 2011 CFR

2011-10-01

... initiation that is sensitive to external electromagnetic radiation, must have its means of initiation effectively protected from electromagnetic radiation sources (for example, radar or radio transmitters...

49 CFR 173.60 - General packaging requirements for explosives.

Code of Federal Regulations, 2010 CFR

2010-10-01

... initiation that is sensitive to external electromagnetic radiation, must have its means of initiation effectively protected from electromagnetic radiation sources (for example, radar or radio transmitters...

49 CFR 173.60 - General packaging requirements for explosives.

Code of Federal Regulations, 2012 CFR

2012-10-01

... initiation that is sensitive to external electromagnetic radiation, must have its means of initiation effectively protected from electromagnetic radiation sources (for example, radar or radio transmitters...

49 CFR 173.60 - General packaging requirements for explosives.

Code of Federal Regulations, 2014 CFR

2014-10-01

... initiation that is sensitive to external electromagnetic radiation, must have its means of initiation effectively protected from electromagnetic radiation sources (for example, radar or radio transmitters...

49 CFR 173.60 - General packaging requirements for explosives.

Code of Federal Regulations, 2013 CFR

2013-10-01

... initiation that is sensitive to external electromagnetic radiation, must have its means of initiation effectively protected from electromagnetic radiation sources (for example, radar or radio transmitters...

[Paternal exposure to occupational electromagnetic radiation and sex ratio of the offspring: a meta-analysis].

PubMed

Tong, Shu-Hui; Liu, Yi-Ting; Liu, Yang

2013-02-01

To investigate the association between paternal exposure to occupational electromagnetic radiation and the sex ratio of the offspring. We searched various databases, including PubMed, Embase, Cochrane Library, OVID, Bioscience Information Service (BIOSIS), China National Knowledge Infrastructure, VIP Database for Chinese Technical Periodicals and Wanfang Database, for the literature relevant to the association of paternal exposure to occupational electromagnetic radiation with the sex ratio of the offspring. We conducted a meta-analysis on their correlation using Stata 11.0. There was no statistically significant difference in the sex ratio between the offspring with paternal exposure to occupational electromagnetic radiation and those without (pooled OR = 1.00 [95% CI: 0.95 -1.05], P = 0.875). Subgroup analysis of both case-control and cohort studies revealed no significant difference (pooled OR = 1.03 [95% CI: 0.99 -1.08], P = 0.104 and pooled OR = 0.98 [95% CI: 0.99 -1.08], P = 0.186, respectively). Paternal exposure to occupational electromagnetic radiation is not correlated with the sex ratio of the offspring.

Effects of electromagnetic radiation on the hemorheology of rats

NASA Astrophysics Data System (ADS)

Huang, Zhiwei; Tian, Tian; Xiao, Bo; Li, Wen

2017-01-01

The current work examines the effects of electromagnetic radiation on the hemorheology to provide an experimental basis for radiation protection. Electromagnetic radiation was generated by a Helmholtz coil constructed from copper wire. There were six rats altogether: three rats in the experimental group, and three rats in the control group. The rats in the experimental group were continuously exposed to radiation for 10 hours every day, and rats in the control group remained in a normal environment. After 30 days, the characteristics of hemorheology of the two groups were compared. The average plasma viscosity, whole blood high shear velocity, and whole blood low shear viscosity were lower in rats in the experimental group than in rats in the control group, while the whole blood shear viscosity was higher in the experimental group than in the control group. Results suggest that long term exposure to electromagnetic radiation does have certain impacts on the cardiovascular system, deeming it necessary to take preventative measures.

Lorentz-Abraham-Dirac versus Landau-Lifshitz radiation friction force in the ultrarelativistic electron interaction with electromagnetic wave (exact solutions).

PubMed

Bulanov, Sergei V; Esirkepov, Timur Zh; Kando, Masaki; Koga, James K; Bulanov, Stepan S

2011-11-01

When the parameters of electron-extreme power laser interaction enter the regime of dominated radiation reaction, the electron dynamics changes qualitatively. The adequate theoretical description of this regime becomes crucially important with the use of the radiation friction force either in the Lorentz-Abraham-Dirac form, which possesses unphysical runaway solutions, or in the Landau-Lifshitz form, which is a perturbation valid for relatively low electromagnetic wave amplitude. The goal of the present paper is to find the limits of the Landau-Lifshitz radiation force applicability in terms of the electromagnetic wave amplitude and frequency. For this, a class of the exact solutions to the nonlinear problems of charged particle motion in the time-varying electromagnetic field is used.

Lorentz-Abraham-Dirac versus Landau-Lifshitz radiation friction force in the ultrarelativistic electron interaction with electromagnetic wave (exact solutions)

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

Bulanov, Sergei V.; Esirkepov, Timur Zh.; Kando, Masaki

2011-11-15

When the parameters of electron-extreme power laser interaction enter the regime of dominated radiation reaction, the electron dynamics changes qualitatively. The adequate theoretical description of this regime becomes crucially important with the use of the radiation friction force either in the Lorentz-Abraham-Dirac form, which possesses unphysical runaway solutions, or in the Landau-Lifshitz form, which is a perturbation valid for relatively low electromagnetic wave amplitude. The goal of the present paper is to find the limits of the Landau-Lifshitz radiation force applicability in terms of the electromagnetic wave amplitude and frequency. For this, a class of the exact solutions to themore » nonlinear problems of charged particle motion in the time-varying electromagnetic field is used.« less

Low cost impulse compatible wideband antenna

DOEpatents

Rosenbury, Erwin T.; Burke, Gerald J.; Nelson, Scott D.; Stever, Robert D.; Governo, George K.; Mullenhoff, Donald J.

2002-01-01

An antenna apparatus and method for building the antenna is disclosed. Impulse signals travel through a feed point of the antenna with respect to a ground plane. A geometric fin structure is connected to the feed point, and through a termination resistance to the ground plane. A geometric ridge structure connected to the ground is positioned with respect to the fin in order to receive and radiate electromagnetic energy from the impulse signal at a predetermined impedance and over a predetermined set of frequencies. The fin and ridge can be either a wire or a planar surface. The fin and ridge may be disposed within a radiation cavity such as a horn. The radiation cavity is constructed of stamped and etched metal sheets bent and then soldered together. The fin and ridge are also formed from metal sheets or wires. The fin is attached to the feed point and then to the cavity through a termination resistance. The ridge is attached to the cavity and disposed with respect to the fin in order to achieve a particular set of antenna characteristics.

Electromagnetic Simulations of Ground-Penetrating Radar Propagation near Lunar Pits and Lava Tubes

NASA Technical Reports Server (NTRS)

Zimmerman, M. I.; Carter, L. M.; Farrell, W. M.; Bleacher, J. E.; Petro, N. E.

2013-01-01

Placing an Orion capsule at the Earth-Moon L2 point (EML2) would potentially enable telerobotic operation of a rover on the lunar surface. The Human Exploration Virtual Institute (HEVI) is proposing that rover operations be carried out near one of the recently discovered lunar pits, which may provide radiation shielding for long duration human stays as well as a cross-disciplinary, science-rich target for nearer-term telerobotic exploration. Ground penetrating radar (GPR) instrumentation included onboard a rover has the potential to reveal many details of underground geologic structures near a pit, as well as characteristics of the pit itself. In the present work we employ the full-wave electromagnetic code MEEP to simulate such GPR reflections from a lunar pit and other subsurface features including lava tubes. These simulations will feed forward to mission concepts requiring knowledge of where to hide from harmful radiation and other environmental hazards such as plama charging and extreme diurnal temperatures.

Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice.

PubMed

Choi, Yu-Jin; Choi, Yun-Sik

2016-02-01

Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spatial working memory was examined with a Y maze, and proliferation of hippocampal progenitor cells were examined by 5-bromo-2'-deoxyuridine administration and immunohistochemical detection. When spatial working memory on a Y maze was examined in the 9(th) week, there was no significant difference in the spontaneous alternation score on the Y maze between the two groups. In addition, there was no significant difference in hippocampal progenitor cell proliferation. However, immunoreactivity to glial fibrillary acidic protein was increased in exposed animals. Next, to test the effect of recovery following chronic radiation exposure, the remaining female mice were further exposed to electromagnetic radiation for 2 more weeks (total 11 weeks), and spontaneous alternation was tested 4 weeks later. In this experiment, although there was no significant difference in the spontaneous alternation scores, the number of arm entry was significantly increased. These data indicate that although chronic electromagnetic radiation does not affect spatial working memory and hippocampal progenitor cell proliferation it can mediate astrocyte activation in the hippocampus and delayed hyperactivity-like behavior.

49 CFR 176.150 - Radio and radar.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., unloaded, or handled, the responsible person must ensure that all sources of electromagnetic radiation such... are sensitive to electromagnetic radiation from external sources must be stowed at a safe distance...

49 CFR 176.150 - Radio and radar.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., unloaded, or handled, the responsible person must ensure that all sources of electromagnetic radiation such... are sensitive to electromagnetic radiation from external sources must be stowed at a safe distance...

49 CFR 176.150 - Radio and radar.

Code of Federal Regulations, 2010 CFR

2010-10-01

..., unloaded, or handled, the responsible person must ensure that all sources of electromagnetic radiation such... are sensitive to electromagnetic radiation from external sources must be stowed at a safe distance...

49 CFR 176.150 - Radio and radar.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., unloaded, or handled, the responsible person must ensure that all sources of electromagnetic radiation such... are sensitive to electromagnetic radiation from external sources must be stowed at a safe distance...

49 CFR 176.150 - Radio and radar.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., unloaded, or handled, the responsible person must ensure that all sources of electromagnetic radiation such... are sensitive to electromagnetic radiation from external sources must be stowed at a safe distance...

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 variation of the fine-structure constant from disformal couplings

NASA Astrophysics Data System (ADS)

van de Bruck, Carsten; Mifsud, Jurgen; Nunes, Nelson J.

2015-12-01

We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure constant, α. As a result, the theory we consider can explain the non-zero reported variation in the evolution of α by purely considering disformal couplings. We also find that if matter and photons are coupled in the same way to the scalar field, disformal couplings itself do not lead to a variation of the fine-structure constant. A number of scenarios are discussed consistent with the current astrophysical, geochemical, laboratory and the cosmic microwave background radiation constraints on the cosmological evolution of α. The models presented are also consistent with the current type Ia supernovae constraints on the effective dark energy equation of state. We find that the Oklo bound in particular puts strong constraints on the model parameters. From our numerical results, we find that the introduction of a non-minimal electromagnetic coupling enhances the cosmological variation in α. Better constrained data is expected to be reported by ALMA and with the forthcoming generation of high-resolution ultra-stable spectrographs such as PEPSI, ESPRESSO, and ELT-HIRES. Furthermore, an expected increase in the sensitivity of molecular and nuclear clocks will put a more stringent constraint on the theory.

The variation of the fine-structure constant from disformal couplings

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

De Bruck, Carsten van; Mifsud, Jurgen; Nunes, Nelson J., E-mail: c.vandebruck@sheffield.ac.uk, E-mail: jmifsud1@sheffield.ac.uk, E-mail: njnunes@fc.ul.pt

2015-12-01

We study a theory in which the electromagnetic field is disformally coupled to a scalar field, in addition to a usual non-minimal electromagnetic coupling. We show that disformal couplings modify the expression for the fine-structure constant, α. As a result, the theory we consider can explain the non-zero reported variation in the evolution of α by purely considering disformal couplings. We also find that if matter and photons are coupled in the same way to the scalar field, disformal couplings itself do not lead to a variation of the fine-structure constant. A number of scenarios are discussed consistent with themore » current astrophysical, geochemical, laboratory and the cosmic microwave background radiation constraints on the cosmological evolution of α. The models presented are also consistent with the current type Ia supernovae constraints on the effective dark energy equation of state. We find that the Oklo bound in particular puts strong constraints on the model parameters. From our numerical results, we find that the introduction of a non-minimal electromagnetic coupling enhances the cosmological variation in α. Better constrained data is expected to be reported by ALMA and with the forthcoming generation of high-resolution ultra-stable spectrographs such as PEPSI, ESPRESSO, and ELT-HIRES. Furthermore, an expected increase in the sensitivity of molecular and nuclear clocks will put a more stringent constraint on the theory.« less

Detailed observations of the source of terrestrial narrowband electromagnetic radiation

NASA Technical Reports Server (NTRS)

Kurth, W. S.

1982-01-01

Detailed observations are presented of a region near the terrestrial plasmapause where narrowband electromagnetic radiation (previously called escaping nonthermal continuum radiation) is being generated. These observations show a direct correspondence between the narrowband radio emissions and electron cyclotron harmonic waves near the upper hybrid resonance frequency. In addition, electromagnetic radiation propagating in the Z-mode is observed in the source region which provides an extremely accurate determination of the electron plasma frequency and, hence, density profile of the source region. The data strongly suggest that electrostatic waves and not Cerenkov radiation are the source of the banded radio emissions and define the coupling which must be described by any viable theory.

Modeling of Ultrasonic and Terahertz Radiations in Defective Tiles for Condition Monitoring of Thermal Protection Systems

DTIC Science & Technology

2013-04-01

different ultrasonic and electromagnetic field modeling problems for NDE (nondestructive evaluation) applications [5- 14]. 2d . Use of the...transient ultrasonic wave propagation using the Distributed Point Source Method”, IEEE Transactions on Ultrasonics, Ferroelectric and Frequency Control...Cavity”, IEEE Transactions on Ultrasonics, Ferroelectric and Frequency Control, Vol. 57(6), pp. 1396-1404, 2010. [10] A. Shelke, S. Das and T. Kundu

78 FR 73475 - Defense Federal Acquisition Regulation Supplement: Clauses With Alternates-Research and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

... electromagnetic radiating device to the Contracting Officer during the initial planning, experimental, or... proposed electromagnetic radiating device to the Contracting Officer during the initial planning...

Using Electromagnetic Microwave Field Combined With Laserotherapy in Postoperative Period of Patients With Purulent-Inflammatory Diseases of the Hand in Outpatient Clinic

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

Rabenok, L.; Grimalsky, V.; Juarez R, D.

2008-08-11

The results of a treatment of 51 patients with purulent-inflammatory diseases of the hand in outpatient clinic are analyzed; a new method of treatment using electromagnetic (EM) microwave field combined with laserotherapy was applied. A portable apparatus was used that operates in the millimeter (mm) wave range in 4 regimes of an intensity 2-10 mW/cm{sup 2} and a red laser of 0.65 {mu}m wavelength of a low intensity 10-15 mW/cm{sup 2}. A peculiarity of the method was an absence of any antibacterial medicine. An exposure of an influence was 10 min. The total course included 5-7 applications. An influence ofmore » low intensity EM radiation was started 15-20 min before the operation. The action was to the center of purulent inflammation and to the biological active points of acupuncture (G14, E36). Starting from the first day since the operation, the low intensity EM radiation was applied to the biological active points combined with laserotherapy to the wound in the sedative regime (the repetition rate 9-10 Hz) during 10 min. Clinical symptomatology, radiographic findings, the results of microbiologic, morphologic studies were analyzed as well and were satisfactory (without any complications)« less

Using Electromagnetic Microwave Field Combined With Laserotherapy in Postoperative Period of Patients With Purulent-Inflammatory Diseases of the Hand in Outpatient Clinic

NASA Astrophysics Data System (ADS)

Rabenok, L.; Grimalsky, V.; Juárez-R., D.

2008-08-01

The results of a treatment of 51 patients with purulent-inflammatory diseases of the hand in outpatient clinic are analyzed; a new method of treatment using electromagnetic (EM) microwave field combined with laserotherapy was applied. A portable apparatus was used that operates in the millimeter (mm) wave range in 4 regimes of an intensity 2-10 mW / cm2 and a red laser of 0.65 μm wavelength of a low intensity 10-15 mW / cm2 . A peculiarity of the method was an absence of any antibacterial medicine. An exposure of an influence was 10 min. The total course included 5-7 applications. An influence of low intensity EM radiation was started 15-20 min before the operation. The action was to the center of purulent inflammation and to the biological active points of acupuncture (G14, E36). Starting from the first day since the operation, the low intensity EM radiation was applied to the biological active points combined with laserotherapy to the wound in the sedative regime (the repetition rate 9-10 Hz) during 10 min. Clinical symptomatology, radiographic findings, the results of microbiologic, morphologic studies were analyzed as well and were satisfactory (without any complications).

Mapping the Baby Universe

NASA Technical Reports Server (NTRS)

Wanjek, Christopher

2003-01-01

In June, NASA plans to launch the Microwave Anisotropy Probe (MAP) to survey the ancient radiation in unprecedented detail. MAP will map slight temperature fluctuations within the microwave background that vary by only 0.00001 C across a chilly radiation that now averages 2.73 C above absolute zero. The temperature differences today point back to density differences in the fiery baby universe, in which there was a little more matter here and a little less matter there. Areas of slightly enhanced density had stronger gravity than low-density areas. The high-density areas pulled back on the background radiation, making it appear slightly cooler in those directions.

Radiation Forces and Torques without Stress (Tensors)

ERIC Educational Resources Information Center

Bohren, Craig F.

2011-01-01

To understand radiation forces and torques or to calculate them does not require invoking photon or electromagnetic field momentum transfer or stress tensors. According to continuum electromagnetic theory, forces and torques exerted by radiation are a consequence of electric and magnetic fields acting on charges and currents that the fields induce…

Electromagnetic radiation from beam-plasma instabilities

NASA Technical Reports Server (NTRS)

Pritchett, P. L.; Dawson, J. M.

1983-01-01

A computer simulation is developed for the generation of electromagnetic radiation in an electron beam-plasma interaction. The plasma is treated as a two-dimensional finite system, and effects of a continuous nonrelativistic beam input are accounted for. Three momentum and three field components are included in the simulation, and an external magnetic field is excluded. EM radiation generation is possible through interaction among Langmuir oscillations, ion-acoustic waves, and the electromagnetic wave, producing radiation perpendicular to the beam. The radiation is located near the plasma frequency, and polarized with the E component parallel to the beam. The scattering of Langmuir waves caused by ion-acoustic fluctuations generates the radiation. Comparison with laboratory data for the three-wave interactions shows good agreement in terms of the radiation levels produced, which are small relative to the plasma thermal energy.

Exposure safety standards for nonionizing radiation (NIR) from collision-avoidance radar

NASA Astrophysics Data System (ADS)

Palmer-Fortune, Joyce; Brecher, Aviva; Spencer, Paul; Huguenin, Richard; Woods, Ken

1997-02-01

On-vehicle technology for collision avoidance using millimeter wave radar is currently under development and is expected to be in vehicles in coming years. Recently approved radar bands for collision avoidance applications include 47.5 - 47.8 GHz and 76 - 77 GHz. Widespread use of active radiation sources in the public domain would contribute to raised levels of human exposure to high frequency electromagnetic radiation, with potential for adverse health effects. In order to design collision avoidance systems that will pose an acceptably low radiation hazard, it is necessary to determine what levels of electromagnetic radiation at millimeter wave frequencies will be acceptable in the environment. This paper will summarize recent research on NIR (non-ionizing radiation) exposure safety standards for high frequency electromagnetic radiation. We have investigated both governmental and non- governmental professional organizations worldwide.

Experiments on active isolation using distributed PVDF error sensors

NASA Technical Reports Server (NTRS)

Lefebvre, S.; Guigou, C.; Fuller, C. R.

1992-01-01

A control system based on a two-channel narrow-band LMS algorithm is used to isolate periodic vibration at low frequencies on a structure composed of a rigid top plate mounted on a flexible receiving plate. The control performance of distributed PVDF error sensors and accelerometer point sensors is compared. For both sensors, high levels of global reduction, up to 32 dB, have been obtained. It is found that, by driving the PVDF strip output voltage to zero, the controller may force the structure to vibrate so that the integration of the strain under the length of the PVDF strip is zero. This ability of the PVDF sensors to act as spatial filters is especially relevant in active control of sound radiation. It is concluded that the PVDF sensors are flexible, nonfragile, and inexpensive and can be used as strain sensors for active control applications of vibration isolation and sound radiation.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon [Pinole, CA; Bruchez, Jr., Marcel; Alivisatos, Paul [Oakland, CA

2008-01-01

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) an affinity molecule linked to the semiconductor nanocrystal. The semiconductor nanocrystal is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Exposure of the semiconductor nanocrystal to excitation energy will excite the semiconductor nanocrystal causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

A Route to Chaotic Behavior of Single Neuron Exposed to External Electromagnetic Radiation.

PubMed

Feng, Peihua; Wu, Ying; Zhang, Jiazhong

2017-01-01

Non-linear behaviors of a single neuron described by Fitzhugh-Nagumo (FHN) neuron model, with external electromagnetic radiation considered, is investigated. It is discovered that with external electromagnetic radiation in form of a cosine function, the mode selection of membrane potential occurs among periodic, quasi-periodic, and chaotic motions as increasing the frequency of external transmembrane current, which is selected as a sinusoidal function. When the frequency is small or large enough, periodic, and quasi-periodic motions are captured alternatively. Otherwise, when frequency is in interval 0.778 < ω < 2.208, chaotic motion characterizes the main behavior type. The mechanism of mode transition from quasi-periodic to chaotic motion is also observed when varying the amplitude of external electromagnetic radiation. The frequency apparently plays a more important role in determining the system behavior.

A Route to Chaotic Behavior of Single Neuron Exposed to External Electromagnetic Radiation

PubMed Central

Feng, Peihua; Wu, Ying; Zhang, Jiazhong

2017-01-01

Non-linear behaviors of a single neuron described by Fitzhugh-Nagumo (FHN) neuron model, with external electromagnetic radiation considered, is investigated. It is discovered that with external electromagnetic radiation in form of a cosine function, the mode selection of membrane potential occurs among periodic, quasi-periodic, and chaotic motions as increasing the frequency of external transmembrane current, which is selected as a sinusoidal function. When the frequency is small or large enough, periodic, and quasi-periodic motions are captured alternatively. Otherwise, when frequency is in interval 0.778 < ω < 2.208, chaotic motion characterizes the main behavior type. The mechanism of mode transition from quasi-periodic to chaotic motion is also observed when varying the amplitude of external electromagnetic radiation. The frequency apparently plays a more important role in determining the system behavior. PMID:29089882

On the dynamic toroidal multipoles from localized electric current distributions.

PubMed

Fernandez-Corbaton, Ivan; Nanz, Stefan; Rockstuhl, Carsten

2017-08-08

We analyze the dynamic toroidal multipoles and prove that they do not have an independent physical meaning with respect to their interaction with electromagnetic waves. We analytically show how the split into electric and toroidal parts causes the appearance of non-radiative components in each of the two parts. These non-radiative components, which cancel each other when both parts are summed, preclude the separate determination of each part by means of measurements of the radiation from the source or of its coupling to external electromagnetic waves. In other words, there is no toroidal radiation or independent toroidal electromagnetic coupling. The formal meaning of the toroidal multipoles is clear in our derivations. They are the higher order terms of an expansion of the multipolar coefficients of electric parity with respect to the electromagnetic size of the source.

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.

The electromagnetic interference of mobile phones on the function of a γ-camera.

PubMed

Javadi, Hamid; Azizmohammadi, Zahra; Mahmoud Pashazadeh, Ali; Neshandar Asli, Isa; Moazzeni, Taleb; Baharfar, Nastaran; Shafiei, Babak; Nabipour, Iraj; Assadi, Majid

2014-03-01

The aim of the present study is to evaluate whether or not the electromagnetic field generated by mobile phones interferes with the function of a SPECT γ-camera during data acquisition. We tested the effects of 7 models of mobile phones on 1 SPECT γ-camera. The mobile phones were tested when making a call, in ringing mode, and in standby mode. The γ-camera function was assessed during data acquisition from a planar source and a point source of Tc with activities of 10 mCi and 3 mCi, respectively. A significant visual decrease in count number was considered to be electromagnetic interference (EMI). The percentage of induced EMI with the γ-camera per mobile phone was in the range of 0% to 100%. The incidence of EMI was mainly observed in the first seconds of ringing and then mitigated in the following frames. Mobile phones are portable sources of electromagnetic radiation, and there is interference potential with the function of SPECT γ-cameras leading to adverse effects on the quality of the acquired images.

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.

Electromagnetic compatibility of PLC adapters for in-home/domestic networks

NASA Astrophysics Data System (ADS)

Potisk, Lukas; Hallon, Jozef; Orgon, Milos; Fujdiak, Radek

2018-01-01

The use of programable logic controllers (PLC) technology in electrical networks 230 V causes electromagnetic radiation that interferes with other electrical equipment connected to the network [1-4]. Therefore, this article describes the issues of electromagnetic compatibility (EMC) of new PLC adapters used in IP broadband services in a multi-user environment. The measurements of disturbing electromagnetic field originated in PLC adapters were made in a certified laboratory EMC (laboratory of electromagnetic compatibility) in the Institute of Electrical Engineering at Faculty of Electrical Engineering and Information Technology of the Slovak University of Technology in Bratislava. The measured spectra of the radiated electromagnetic field will be compared with the results obtained when testing older PLC modems [5].

[Dynamics of biomacromolecules in coherent electromagnetic radiation field].

PubMed

Leshcheniuk, N S; Apanasevich, E E; Tereshenkov, V I

2014-01-01

It is shown that induced oscillations and periodic displacements of the equilibrium positions occur in biomacromolecules in the absence of electromagnetic radiation absorption, due to modulation of interaction potential between atoms and groups of atoms forming the non-valence bonds in macromolecules by the external electromagnetic field. Such "hyperoscillation" state causes inevitably the changes in biochemical properties of macromolecules and conformational transformation times.

Research on Radiation Characteristic of Plasma Antenna through FDTD Method

PubMed Central

Zhou, Jianming; Fang, Jingjing; Lu, Qiuyuan; Liu, Fan

2014-01-01

The radiation characteristic of plasma antenna is investigated by using the finite-difference time-domain (FDTD) approach in this paper. Through using FDTD method, we study the propagation of electromagnetic wave in free space in stretched coordinate. And the iterative equations of Maxwell equation are derived. In order to validate the correctness of this method, we simulate the process of electromagnetic wave propagating in free space. Results show that electromagnetic wave spreads out around the signal source and can be absorbed by the perfectly matched layer (PML). Otherwise, we study the propagation of electromagnetic wave in plasma by using the Boltzmann-Maxwell theory. In order to verify this theory, the whole process of electromagnetic wave propagating in plasma under one-dimension case is simulated. Results show that Boltzmann-Maxwell theory can be used to explain the phenomenon of electromagnetic wave propagating in plasma. Finally, the two-dimensional simulation model of plasma antenna is established under the cylindrical coordinate. And the near-field and far-field radiation pattern of plasma antenna are obtained. The experiments show that the variation of electron density can introduce the change of radiation characteristic. PMID:25114961

[Study on effects of bioelectric parameters of rats in electromagnetic radiation of HV transmission line].

PubMed

Zhang, Anying; Pang, Xiaofeng; Yuan, Ping

2007-02-01

With the development of economy and coming of information era, the chance of exposure to electromagnetic fields with various frequencies has been increased for every human. The effects of electromagnetic radiattion on human being's health are versatile. To study the effects of bioelctronic parameters of rats in the electromagnetic radiations of HV transmission line, EEG, ECG and CMAP were measured in rats exposed to simulating high-voltage transmission line electromagnetic radiation for over one year. Brain tissues were studied by Fourier transform infrared spectroscopy. The results showed that no significant difference between exposed group and control group in EEG; however the FT-infrared spectra of brain tissues were different; the ECG of the exposed animals was considerably altered. Significant slowing of heart rate was observed in those rates exposed to EMFs; the latent period of CMAP in exposed group were not different compared with those of control group however there was a significant difference in wave amplitude of CMAP between the exposed group and control group. All results indicated that there must be some effects on bioelectric parameters of rats exposed to electromagnetic radiation of high-voltage transmission line for a long time.

Modulated wave formation in myocardial cells under electromagnetic radiation

NASA Astrophysics Data System (ADS)

Takembo, Clovis N.; Mvogo, A.; Ekobena Fouda, H. P.; Kofané, T. C.

2018-06-01

We exclusively analyze the onset and condition of formation of modulated waves in a diffusive FitzHugh-Nagumo model for myocardial cell excitations. The cells are connected through gap junction coupling. An additive magnetic flux variable is used to describe the effect of electromagnetic induction, while electromagnetic radiation is imposed on the magnetic flux variable as a periodic forcing. We used the discrete multiple scale expansion and obtained, from the model equations, a single differential-difference amplitude nonlinear equation. We performed the linear stability analysis of this equation and found that instability features are importantly influenced by the induced electromagnetic gain. We present the unstable and stable regions of modulational instability (MI). The resulting analytic predictions are confirmed by numerical experiments of the generic equations. The results reveal that due to MI, an initial steady state that consisted of a plane wave with low amplitude evolves into a modulated localized wave patterns, soliton-like in shape, with features of synchronization. Furthermore, the formation of periodic pulse train with breathing motion presents a disappearing pattern in the presence of electromagnetic radiation. This could provide guidance and better understanding of sudden heart failure exposed to heavily electromagnetic radiation.

Effects of Electromagnetic Radiation from Smartphones on Learning Ability and Hippocampal Progenitor Cell Proliferation in Mice

PubMed Central

Choi, Yu-Jin; Choi, Yun-Sik

2015-01-01

Objectives Nonionizing radiation is emitted from electronic devices, such as smartphones. In this study, we intended to elucidate the effect of electromagnetic radiation from smartphones on spatial working memory and progenitor cell proliferation in the hippocampus. Methods Both male and female mice were randomly separated into two groups (radiated and control) and the radiated group was exposed to electromagnetic radiation for 9 weeks and 11 weeks for male and female mice, respectively. Spatial working memory was examined with a Y maze, and proliferation of hippocampal progenitor cells were examined by 5-bromo-2′-deoxyuridine administration and immunohistochemical detection. Results When spatial working memory on a Y maze was examined in the 9th week, there was no significant difference in the spontaneous alternation score on the Y maze between the two groups. In addition, there was no significant difference in hippocampal progenitor cell proliferation. However, immunoreactivity to glial fibrillary acidic protein was increased in exposed animals. Next, to test the effect of recovery following chronic radiation exposure, the remaining female mice were further exposed to electromagnetic radiation for 2 more weeks (total 11 weeks), and spontaneous alternation was tested 4 weeks later. In this experiment, although there was no significant difference in the spontaneous alternation scores, the number of arm entry was significantly increased. Conclusion These data indicate that although chronic electromagnetic radiation does not affect spatial working memory and hippocampal progenitor cell proliferation it can mediate astrocyte activation in the hippocampus and delayed hyperactivity-like behavior. PMID:26981337

Research on the electromagnetic radiation characteristics of the gas main switch of a capacitive intense electron-beam accelerator

NASA Astrophysics Data System (ADS)

Qiu, Yongfeng; Liu, Jinliang; Yang, Jianhua; Cheng, Xinbing; Li, Guolin

2017-11-01

Strong electromagnetic fields are radiated during the operation of the intense electron-beam accelerator (IEBA), which may lead to the nearby electronic devices out of order. In this paper, the research on the electromagnetic radiation characteristic of the gas main switch of a capacitive IEBA is carried out by the methods of theory analysis and experiment investigation. It is obtained that the gas main switch is the dominating radiation resource. In the absence of electromagnetic shielding for the gas main switch, when the pulse forming line of the IEBA is charged to 700 kV, the radiation field with amplitude of 3280 V/m, dominant frequency of 84 MHz and high frequency 100 MHz is obtained at a distance of 10 meters away from the gas main switch. The experimental results of the radiation field agree with the theoretical calculations. We analyze the achievements of several research groups and find that there is a relationship between the rise time (T) of the transient current of the gas main switch and the dominant frequency (F) of the radiation field, namely, F*T=1. Contrast experiment is carried out with a metal shield cover for the gas main switch. Experimental results show that for the shielded setup the radiation field reduces to 115 V/m, the dominant frequency increases to 86.5 MHz at a distance of 10 away meters from the gas main switch. These conclusions are beneficial for further research on the electromagnetic radiation and protection of the IEBA.

Stability of the accelerated expansion in nonlinear electrodynamics

NASA Astrophysics Data System (ADS)

Sharif, M.; Mumtaz, Saadia

2017-02-01

This paper is devoted to the phase space analysis of an isotropic and homogeneous model of the universe by taking a noninteracting mixture of the electromagnetic and viscous radiating fluids whose viscous pressure satisfies a nonlinear version of the Israel-Stewart transport equation. We establish an autonomous system of equations by introducing normalized dimensionless variables. In order to analyze the stability of the system, we find corresponding critical points for different values of the parameters. We also evaluate the power-law scale factor whose behavior indicates different phases of the universe in this model. It is concluded that the bulk viscosity as well as electromagnetic field enhances the stability of the accelerated expansion of the isotropic and homogeneous model of the universe.

Improving microwave antenna gain and bandwidth with phase compensation metasurface

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

Chen, Ke; Yang, Zhongjie; Feng, Yijun, E-mail: yjfeng@nju.edu.cn

Metasurface, as a planar version of artificial metamaterial, provide an effective way to manipulate electromagnetic wave propagation. Here, we present a transparent metasurface for compensating the out-of-phase radiation from a microstrip patch antenna to improve its radiation gain and bandwidth. Based on the equivalence principle of Huygens’ surface, we propose metasurface composed of both inductive and capacitive resonant elements which could produce high transmission with variable phase characteristics. Such metasurface mounted on a patch antenna can transform the spherical-like phase profile generated from the patch into an in-phase planar one. A prototype antenna has been fabricated and validated the squeezedmore » radiation pattern with suppressed sidelobes as well as enhanced impedance bandwidth due to strong near-field coupling. As operating at around 5.7 GHz, the proposed antenna may have potential application in wireless communication systems especially for point-to-point data transmission. It is believed that the design methodology could also be scaled to other frequency bands such as millimeter or terahertz wave.« less

Rigorous derivation of electromagnetic self-force

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

Gralla, Samuel E.; Harte, Abraham I.; Wald, Robert M.

2009-07-15

During the past century, there has been considerable discussion and analysis of the motion of a point charge in an external electromagnetic field in special relativity, taking into account 'self-force' effects due to the particle's own electromagnetic field. We analyze the issue of 'particle motion' in classical electromagnetism in a rigorous and systematic way by considering a one-parameter family of solutions to the coupled Maxwell and matter equations corresponding to having a body whose charge-current density J{sup a}({lambda}) and stress-energy tensor T{sub ab}({lambda}) scale to zero size in an asymptotically self-similar manner about a worldline {gamma} as {lambda}{yields}0. In thismore » limit, the charge, q, and total mass, m, of the body go to zero, and q/m goes to a well-defined limit. The Maxwell field F{sub ab}({lambda}) is assumed to be the retarded solution associated with J{sup a}({lambda}) plus a homogeneous solution (the 'external field') that varies smoothly with {lambda}. We prove that the worldline {gamma} must be a solution to the Lorentz force equations of motion in the external field F{sub ab}({lambda}=0). We then obtain self-force, dipole forces, and spin force as first-order perturbative corrections to the center-of-mass motion of the body. We believe that this is the first rigorous derivation of the complete first-order correction to Lorentz force motion. We also address the issue of obtaining a self-consistent perturbative equation of motion associated with our perturbative result, and argue that the self-force equations of motion that have previously been written down in conjunction with the 'reduction of order' procedure should provide accurate equations of motion for a sufficiently small charged body with negligible dipole moments and spin. (There is no corresponding justification for the non-reduced-order equations.) We restrict consideration in this paper to classical electrodynamics in flat spacetime, but there should be no difficulty in extending our results to the motion of a charged body in an arbitrary globally hyperbolic curved spacetime.« less

Generation of ordinary mode electromagnetic radiation near the upper hybrid frequency in the magnetosphere

NASA Technical Reports Server (NTRS)

Ashour-Abdalla, M.; Okuda, H.

1984-01-01

It is shown by means of plasma numerical simulations that long-wavelength ordinary mode electromagnetic radiation can be generated from short-wavelength electrostatic waves near the upper hybrid resonance frequency in an inhomogeneous plasma. A possible relation of this process to nonthermal continuum radiation in the magnetosphere is discussed.

The emergence of gravity as a retro-causal post-inflation macro-quantum-coherent holographic vacuum Higgs-Goldstone field

NASA Astrophysics Data System (ADS)

Sarfatti, Jack; Levit, Creon

2009-06-01

We present a model for the origin of gravity, dark energy and dark matter: Dark energy and dark matter are residual pre-inflation false vacuum random zero point energy (w = - 1) of large-scale negative, and short-scale positive pressure, respectively, corresponding to the "zero point" (incoherent) component of a superfluid (supersolid) ground state. Gravity, in contrast, arises from the 2nd order topological defects in the post-inflation virtual "condensate" (coherent) component. We predict, as a consequence, that the LHC will never detect exotic real on-mass-shell particles that can explain dark matter ΩMDM approx 0.23. We also point out that the future holographic dark energy de Sitter horizon is a total absorber (in the sense of retro-causal Wheeler-Feynman action-at-a-distance electrodynamics) because it is an infinite redshift surface for static detectors. Therefore, the advanced Hawking-Unruh thermal radiation from the future de Sitter horizon is a candidate for the negative pressure dark vacuum energy.

Apertureless near-field optical microscopy

NASA Astrophysics Data System (ADS)

Kazantsev, D. V.; Kuznetsov, E. V.; Timofeev, S. V.; Shelaev, A. V.; Kazantseva, E. A.

2017-05-01

We discuss the operating principles of the apertureless scanning near-field optical microscope (ASNOM), in which the probe acts as a rod antenna and its electromagnetic radiation plays the role of the registered signal. The phase and amplitude of the emitted wave vary depending on the ‘grounding conditions’ of the antenna tip at the sample point under study. Weak radiation from a tiny (2-15 μm long) tip is detected using optical homo- and heterodyning and the nonlinear dependence of the tip polarizability on the tip-surface distance. The lateral resolution of ASNOMs is determined by the tip curvature radius (1- 20 nm), regardless of the wavelength (500 nm-100 μm). ASNOMs are shown to be capable of providing a surface optical map with nanometer resolution and carrying out spectral- and time-resolved measurements at a selected point on the surface.

Gutenberg-Richter-type relation for laboratory fracture-induced electromagnetic radiation.

PubMed

Rabinovitch, A; Frid, V; Bahat, D

2002-01-01

The fractal nature of electromagnetic radiation induced by uniaxial and triaxial rock fracture is considered. Both the well-known Gutenberg-Richter-type and the Benioff strain-release relationship, for earthquakes and starquakes, are shown to extend to the microscale (millimeters-centimeters). Results show that both the b value of the Gutenberg-Richter-type law and the slope of the Benioff strain-release relationship of the electromagnetic radiation signals are similar to values known for earthquakes. These results imply that a common mechanism is acting at all scales.

Rat testicular impairment induced by electromagnetic radiation from a conventional cellular telephone and the protective effects of the antioxidants vitamins C and E

PubMed Central

Al-Damegh, Mona Abdullah

2012-01-01

OBJECTIVE: The aim of this study was to investigate the possible effects of electromagnetic radiation from conventional cellular phone use on the oxidant and antioxidant status in rat blood and testicular tissue and determine the possible protective role of vitamins C and E in preventing the detrimental effects of electromagnetic radiation on the testes. MATERIALS AND METHODS: The treatment groups were exposed to an electromagnetic field, electromagnetic field plus vitamin C (40 mg/kg/day) or electromagnetic field plus vitamin E (2.7 mg/kg/day). All groups were exposed to the same electromagnetic frequency for 15, 30, and 60 min daily for two weeks. RESULTS: There was a significant increase in the diameter of the seminiferous tubules with a disorganized seminiferous tubule sperm cycle interruption in the electromagnetism-exposed group. The serum and testicular tissue conjugated diene, lipid hydroperoxide, and catalase activities increased 3-fold, whereas the total serum and testicular tissue glutathione and glutathione peroxidase levels decreased 3-5 fold in the electromagnetism-exposed animals. CONCLUSION: Our results indicate that the adverse effect of the generated electromagnetic frequency had a negative impact on testicular architecture and enzymatic activity. This finding also indicated the possible role of vitamins C and E in mitigating the oxidative stress imposed on the testes and restoring normality to the testes. PMID:22892924

Rat testicular impairment induced by electromagnetic radiation from a conventional cellular telephone and the protective effects of the antioxidants vitamins C and E.

PubMed

Al-Damegh, Mona Abdullah

2012-07-01

The aim of this study was to investigate the possible effects of electromagnetic radiation from conventional cellular phone use on the oxidant and antioxidant status in rat blood and testicular tissue and determine the possible protective role of vitamins C and E in preventing the detrimental effects of electromagnetic radiation on the testes. The treatment groups were exposed to an electromagnetic field, electromagnetic field plus vitamin C (40 mg/kg/day) or electromagnetic field plus vitamin E (2.7 mg/kg/day). All groups were exposed to the same electromagnetic frequency for 15, 30, and 60 min daily for two weeks. There was a significant increase in the diameter of the seminiferous tubules with a disorganized seminiferous tubule sperm cycle interruption in the electromagnetism-exposed group. The serum and testicular tissue conjugated diene, lipid hydroperoxide, and catalase activities increased 3-fold, whereas the total serum and testicular tissue glutathione and glutathione peroxidase levels decreased 3-5 fold in the electromagnetism-exposed animals. Our results indicate that the adverse effect of the generated electromagnetic frequency had a negative impact on testicular architecture and enzymatic activity. This finding also indicated the possible role of vitamins C and E in mitigating the oxidative stress imposed on the testes and restoring normality to the testes.

Electromagnetic and nuclear radiation detector using micromechanical sensors

DOEpatents

Thundat, Thomas G.; Warmack, Robert J.; Wachter, Eric A.

2000-01-01

Electromagnetic and nuclear radiation is detected by micromechanical sensors that can be coated with various interactive materials. As the micromechanical sensors absorb radiation, the sensors bend and/or undergo a shift in resonance characteristics. The bending and resonance changes are detected with high sensitivity by any of several detection methods including optical, capacitive, and piezoresistive methods. Wide bands of the electromagnetic spectrum can be imaged with picoJoule sensitivity, and specific absorptive coatings can be used for selective sensitivity in specific wavelength bands. Microcantilevers coated with optical cross-linking polymers are useful as integrating optical radiation dosimeters. Nuclear radiation dosimetry is possible by fabricating cantilevers from materials that are sensitive to various nuclear particles or radiation. Upon exposure to radiation, the cantilever bends due to stress and its resonance frequency shifts due to changes in elastic properties, based on cantilever shape and properties of the coating.

A Near Zero Refractive Index Metamaterial for Electromagnetic Invisibility Cloaking Operation

PubMed Central

Islam, Sikder Sunbeam; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2015-01-01

The paper reveals the design of a unit cell of a metamaterial that shows more than 2 GHz wideband near zero refractive index (NZRI) property in the C-band region of microwave spectra. The two arms of the unit cell were splitted in such a way that forms a near-pi-shape structure on epoxy resin fiber (FR-4) substrate material. The reflection and transmission characteristics of the unit cell were achieved by utilizing finite integration technique based simulation software. Measured results were presented, which complied well with simulated results. The unit cell was then applied to build a single layer rectangular-shaped cloak that operates in the C-band region where a metal cylinder was perfectly hidden electromagnetically by reducing the scattering width below zero. Moreover, the unit cell shows NZRI property there. The experimental result for the cloak operation was presented in terms of S-parameters as well. In addition, the same metamaterial shell was also adopted for designing an eye-shaped and triangular-shaped cloak structure to cloak the same object, and cloaking operation is achieved in the C-band, as well with slightly better cloaking performance. The novel design, NZRI property, and single layer C-band cloaking operation has made the design a promising one in the electromagnetic paradigm. PMID:28793472

A Near Zero Refractive Index Metamaterial for Electromagnetic Invisibility Cloaking Operation.

PubMed

Islam, Sikder Sunbeam; Faruque, Mohammad Rashed Iqbal; Islam, Mohammad Tariqul

2015-07-29

The paper reveals the design of a unit cell of a metamaterial that shows more than 2 GHz wideband near zero refractive index (NZRI) property in the C-band region of microwave spectra. The two arms of the unit cell were splitted in such a way that forms a near-pi-shape structure on epoxy resin fiber (FR-4) substrate material. The reflection and transmission characteristics of the unit cell were achieved by utilizing finite integration technique based simulation software. Measured results were presented, which complied well with simulated results. The unit cell was then applied to build a single layer rectangular-shaped cloak that operates in the C-band region where a metal cylinder was perfectly hidden electromagnetically by reducing the scattering width below zero. Moreover, the unit cell shows NZRI property there. The experimental result for the cloak operation was presented in terms of S-parameters as well. In addition, the same metamaterial shell was also adopted for designing an eye-shaped and triangular-shaped cloak structure to cloak the same object, and cloaking operation is achieved in the C-band, as well with slightly better cloaking performance. The novel design, NZRI property, and single layer C-band cloaking operation has made the design a promising one in the electromagnetic paradigm.

Depolarization and Scattering of Electromagnetic Waves. Appendices.

DTIC Science & Technology

1986-06-30

for both specular point scattering and Bragg scattering in a self-consistent manner is used to express the total cross section of the flake as a...by Arbitrarily Oriented Composite Rough Surfaces. In this work the full wave approach is used to determine the modu- lations of the like and cross...analyze multiple scattering using the equation of radiative transfer with the general Stokes’ parameters. Our ultimate goal is to develop codes which will

Heat Radiators for Electromagnetic Pumps

NASA Technical Reports Server (NTRS)

Campana, R. J.

1986-01-01

Report proposes use of carbon/carbon composite radiators in electromagnetic coolant pumps of nuclear reactors on spacecraft. Carbon/carbon composite materials function well at temperatures in excess of 2,200 K. Aluminum has melting temperature of only 880 K.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2006-09-05

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon [Pinole, CA; Bruchez, Jr., Marcel; Alivisatos, Paul [Oakland, CA

2004-03-02

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe, causing the emission of electromagnetic radiation. Further described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2005-08-09

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2002-01-01

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in he probe, causing the emission of electromagnetic radiation. Further described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Students’ conceptions of radiation and what to do about them

NASA Astrophysics Data System (ADS)

Plotz, Thomas

2017-01-01

For good science teaching, it is necessary to have knowledge of your students’ preconceptions. Numerous studies have been conducted about typical ideas that students bring to the science classroom in science education research. Unfortunately the domains of which we know preconceptions are not distributed evenly and there is a lack of studies about students’ conceptions of electromagnetic radiation. This literature review focuses on the existing body of studies around those conceptions. All studies focusing on conceptions of radiation, including nuclear radiation, have been considered if they were published in international peer reviewed journals in English and German between 1980 and the present day. Some interesting conceptions mentioned in different studies are pointed out, as well as gaps in the literature that need to be filled. At the end, some ideas to conquer misconceptions are presented.

A large-scale measurement of electromagnetic fields near GSM base stations in Guangxi, China for risk communication.

PubMed

Wu, Tongning; Shao, Qing; Yang, Lei; Qi, Dianyuan; Lin, Jun; Lin, Xiaojun; Yu, Zongying

2013-06-01

Radiofrequency (RF) electromagnetic field (EMF) exposure from wireless telecommunication base station antennae can lead to debates, conflicts or litigations among the adjacent residents if inappropriately managed. This paper presents a measurement campaign for the GSM band EMF exposure in the vicinity of 827 base station sites (totally 6207 measurement points) in Guangxi, China. Measurement specifications are designed for risk communication with the residents who previously complained of over-exposure. The EMF power densities with the global positioning system coordinate at each measured point were recorded. Compliance with the International Commission on Non-Ionizing Radiation Protection guidelines and Chinese environmental EMF safety standards was studied. The results show that the GSM band EMF level near the base stations is very low. The measurement results and the EMF risk communication procedures positively influence public perception of the RF EMF exposure from the base stations and promote the exchange of EMF exposure-related knowledge.

Volume integrals associated with the inhomogeneous Helmholtz equation. Part 1: Ellipsoidal region

NASA Technical Reports Server (NTRS)

Fu, L. S.; Mura, T.

1983-01-01

Problems of wave phenomena in fields of acoustics, electromagnetics and elasticity are often reduced to an integration of the inhomogeneous Helmholtz equation. Results are presented for volume integrals associated with the Helmholtz operator, nabla(2) to alpha(2), for the case of an ellipsoidal region. By using appropriate Taylor series expansions and multinomial theorem, these volume integrals are obtained in series form for regions r 4' and r r', where r and r' are distances from the origin to the point of observation and source, respectively. Derivatives of these integrals are easily evaluated. When the wave number approaches zero, the results reduce directly to the potentials of variable densities.

On the fine-structure constant in a plasma model of the fluctuating vacuum substratum

NASA Technical Reports Server (NTRS)

Cragin, B. L.

1986-01-01

The existence of an intimate connection between the quivering motion of electrons and positrons (Zitterbewegung), predicted by the Dirac equation, and the zero-point fluctuations of the vacuum is suggested. The nature of the proposed connection is discussed quantitatively, and an approximate self-consistency relation is derived, supplying a purely mathematical expression that relates the dimensionless coupling strengths (fine-structure constants) alpha sub e and alpha sub g of electromagnetism and gravity. These considerations provide a tentative explanation for the heretofore puzzling number 1/alpha sub e of about 137.036 and suggest that attempts to unify gravity with the electroweak and strong interactions will ultimately prove successful.

Area Monitoring for Detection of Leaks and/or Flames

NASA Technical Reports Server (NTRS)

Mian, Zahid F. (Inventor); Gamache, Ronald W. (Inventor); Glasser, Nick (Inventor)

2015-01-01

A solution for monitoring an area for the presence of a flame and/or a leak, such as from a pressurized fluid, is provided. An imaging device can be used that acquires image data based on electromagnetic radiation having wavelengths only corresponding to at least one region of the electromagnetic spectrum in which electromagnetic radiation from an ambient light source is less than the electromagnetic radiation emitted by at least one type of flame for which the presence within the area is being monitored. An acoustic device can be used that is configured to acquire acoustic data for the area and enhance acoustic signals in a range of frequencies corresponding to a leak of a pressurized fluid present in the area.

Area Monitoring for Detection of Leaks And/Or Flames

NASA Technical Reports Server (NTRS)

Mian, Zahid F. (Inventor); Gamache, Ronald W. (Inventor); Glasser, Nicholas (Inventor)

2017-01-01

A solution for monitoring an area for the presence of a flame and/or a leak, such as from a pressurized fluid, is provided. An imaging device can be used that acquires image data based on electromagnetic radiation having wavelengths only corresponding to at least one region of the electromagnetic spectrum in which electromagnetic radiation from an ambient light source is less than the electromagnetic radiation emitted by at least one type of flame for which the presence within the area is being monitored. An acoustic device can be used that is configured to acquire acoustic data for the area and enhance acoustic signals in a range of frequencies corresponding to a leak of a pressurized fluid present in the area.

A new numerically stable implementation of the T-matrix method for electromagnetic scattering by spheroidal particles

NASA Astrophysics Data System (ADS)

Somerville, W. R. C.; Auguié, B.; Le Ru, E. C.

2013-07-01

We propose, describe, and demonstrate a new numerically stable implementation of the extended boundary-condition method (EBCM) to compute the T-matrix for electromagnetic scattering by spheroidal particles. Our approach relies on the fact that for many of the EBCM integrals in the special case of spheroids, a leading part of the integrand integrates exactly to zero, which causes catastrophic loss of precision in numerical computations. This feature was in fact first pointed out by Waterman in the context of acoustic scattering and electromagnetic scattering by infinite cylinders. We have recently studied it in detail in the case of electromagnetic scattering by particles. Based on this study, the principle of our new implementation is therefore to compute all the integrands without the problematic part to avoid the primary cause of loss of precision. Particular attention is also given to choosing the algorithms that minimise loss of precision in every step of the method, without compromising on speed. We show that the resulting implementation can efficiently compute in double precision arithmetic the T-matrix and therefore optical properties of spheroidal particles to a high precision, often down to a remarkable accuracy (10-10 relative error), over a wide range of parameters that are typically considered problematic. We discuss examples such as high-aspect ratio metallic nanorods and large size parameter (≈35) dielectric particles, which had been previously modelled only using quadruple-precision arithmetic codes.

The feasibility of using methylene blue sensitized polyvinylalcohol film as a linear polarizer

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

Jyothilakshmi, K.; Anju, K. S.; Arathy, K.

2014-01-28

Linear light polarizing films selectively transmit radiations vibrating along an electromagnetic radiation vector and selectively absorb radiations vibrating along a second electromagnetic radiation vector. It happens according to the anisotropy of the film . In the present study the polarization effects of methylene blue sensitized polyvinyl alcohol is investigated. The polarization effects on the dye concentration, heating and stretching of film also are evaluated.

Electromagnetic radiation detector

DOEpatents

Benson, Jay L.; Hansen, Gordon J.

1976-01-01

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

[Use of terahertz electromagnetic radiation at nitric oxide frequencies for the correction of thyroid functional state during stress].

PubMed

Kirichuk, V F; Tsymbal, A A

2010-01-01

The influence of terahertz electromagnetic radiation at nitric oxide frequencies (150.176-150.664 Ghz) on the functional activity of rat thyroid gland subjected to acute immobilization stress has been studied. It is shown that terahertz radiation totally normalizes thyroid activity in stressed animals within 30 min after application.

[UV-radiation--sources, wavelength, environment].

PubMed

Hölzle, Erhard; Hönigsmann, Herbert

2005-09-01

The UV-radiation in our environment is part of the electromagnetic radiation, which emanates from the sun. It is designated as optical radiation and reaches from 290-4,000 nm on the earth's surface. According to international definitions UV irradiation is divided into short-wave UVC (200-280 nm), medium-wave UVB (280-320 nm), and long-wave UVA (320-400 nm). Solar radiation which reaches the surface of the globe at a defined geographical site and a defined time point is called global radiation. It is modified quantitatively and qualitatively while penetrating the atmosphere. Besides atmospheric conditions, like ozone layer and air pollution, geographic latitude, elevation, time of the season, time of the day, cloudiness and the influence of indirect radiation resulting from stray effects in the atmosphere and reflection from the underground play a role in modifying global radiation, which finally represents the biologically effective radiation. The radiation's distribution on the body surface varies according to sun angle and body posture. The cumulative UV exposure is mainly influenced by outdoor profession and recreational activities. The use of sun beds and phototherapeutic measures additionally may contribute to the cumulative UV dose.

On the Intensity of Radiation of an Electromagnetic Field by a Rotating Ferroelectric Sphere

NASA Astrophysics Data System (ADS)

Gladkov, S. O.; Bogdanova, S. B.

2018-05-01

It is shown that in the case when the spontaneous polarization vector P 0 and the rotational frequency vector ω of a ferroelectric sphere do not coincide, electromagnetic waves will be radiated. The intensity of the radiation is calculated as a function of the coordinates and time, and the anisotropy of this radiation is proven. The distribution of the intensity of radiation is graphically illustrated in the form of a function of the central distance r.

[Applications of electromagnetic radiation in medicine].

PubMed

Miłowska, Katarzyna; Grabowska, Katarzyna; Gabryelak, Teresa

2014-05-08

Recent decades have been devoted to the intense search for the response to questions related to the impact of radiation on the human body. Due to the growing fashion for a healthy lifestyle, increasing numbers of works about the alleged dangers of electromagnetic waves and diseases that they cause appeared. However, the discoveries of 20th century, and knowledge of the properties of electromagnetic radiation have allowed to broaden the horizons of the use of artificial sources of radiation in many fields of science and especially in medicine. The aim of this paper is to show that although excessive radiation or high doses are dangerous to the human body, its careful and controlled use, does not pose a threat, and it is often necessary in therapy. The possibility of using ionizing radiation in radiotherapy, isotope diagnostics or medical imaging, and non-ionizing radiation in the treatment for dermatological disorders and cancers will be presented. The unique properties of synchrotron radiation result in using it on a large scale in the diagnosis of pathological states by imaging methods.

Programming an Artificial Neural Network Tool for Spatial Interpolation in GIS - A Case Study for Indoor Radio Wave Propagation of WLAN.

PubMed

Sen, Alper; Gümüsay, M Umit; Kavas, Aktül; Bulucu, Umut

2008-09-25

Wireless communication networks offer subscribers the possibilities of free mobility and access to information anywhere at any time. Therefore, electromagnetic coverage calculations are important for wireless mobile communication systems, especially in Wireless Local Area Networks (WLANs). Before any propagation computation is performed, modeling of indoor radio wave propagation needs accurate geographical information in order to avoid the interruption of data transmissions. Geographic Information Systems (GIS) and spatial interpolation techniques are very efficient for performing indoor radio wave propagation modeling. This paper describes the spatial interpolation of electromagnetic field measurements using a feed-forward back-propagation neural network programmed as a tool in GIS. The accuracy of Artificial Neural Networks (ANN) and geostatistical Kriging were compared by adjusting procedures. The feedforward back-propagation ANN provides adequate accuracy for spatial interpolation, but the predictions of Kriging interpolation are more accurate than the selected ANN. The proposed GIS ensures indoor radio wave propagation model and electromagnetic coverage, the number, position and transmitter power of access points and electromagnetic radiation level. Pollution analysis in a given propagation environment was done and it was demonstrated that WLAN (2.4 GHz) electromagnetic coverage does not lead to any electromagnetic pollution due to the low power levels used. Example interpolated electromagnetic field values for WLAN system in a building of Yildiz Technical University, Turkey, were generated using the selected network architectures to illustrate the results with an ANN.

Programming an Artificial Neural Network Tool for Spatial Interpolation in GIS - A Case Study for Indoor Radio Wave Propagation of WLAN

PubMed Central

Şen, Alper; Gümüşay, M. Ümit; Kavas, Aktül; Bulucu, Umut

2008-01-01

Wireless communication networks offer subscribers the possibilities of free mobility and access to information anywhere at any time. Therefore, electromagnetic coverage calculations are important for wireless mobile communication systems, especially in Wireless Local Area Networks (WLANs). Before any propagation computation is performed, modeling of indoor radio wave propagation needs accurate geographical information in order to avoid the interruption of data transmissions. Geographic Information Systems (GIS) and spatial interpolation techniques are very efficient for performing indoor radio wave propagation modeling. This paper describes the spatial interpolation of electromagnetic field measurements using a feed-forward back-propagation neural network programmed as a tool in GIS. The accuracy of Artificial Neural Networks (ANN) and geostatistical Kriging were compared by adjusting procedures. The feedforward back-propagation ANN provides adequate accuracy for spatial interpolation, but the predictions of Kriging interpolation are more accurate than the selected ANN. The proposed GIS ensures indoor radio wave propagation model and electromagnetic coverage, the number, position and transmitter power of access points and electromagnetic radiation level. Pollution analysis in a given propagation environment was done and it was demonstrated that WLAN (2.4 GHz) electromagnetic coverage does not lead to any electromagnetic pollution due to the low power levels used. Example interpolated electromagnetic field values for WLAN system in a building of Yildiz Technical University, Turkey, were generated using the selected network architectures to illustrate the results with an ANN. PMID:27873854

Gauge Invariant Formulation of the Interaction of Electromagnetic Radiation and Matter

ERIC Educational Resources Information Center

Kobe, Donald H.; Smirl, Arthur L.

1978-01-01

Presents a discussion in Perturbation theory in quantum mechanics for the interaction of electromagnetic radiation with matter. Advocates the use of electric dipole interaction whenever it can be used as compared to the vector potential interaction. (GA)

Terahertz metamaterials

DOEpatents

Peralta, Xomalin Guaiuli; Brener, Igal; O'Hara, John; Azad, Abul; Smirnova, Evgenya; Williams, John D.; Averitt, Richard D.

2014-08-12

Terahertz metamaterials comprise a periodic array of resonator elements disposed on a dielectric substrate or thin membrane, wherein the resonator elements have a structure that provides a tunable magnetic permeability or a tunable electric permittivity for incident electromagnetic radiation at a frequency greater than about 100 GHz and the periodic array has a lattice constant that is smaller than the wavelength of the incident electromagnetic radiation. Microfabricated metamaterials exhibit lower losses and can be assembled into three-dimensional structures that enable full coupling of incident electromagnetic terahertz radiation in two or three orthogonal directions. Furthermore, polarization sensitive and insensitive metamaterials at terahertz frequencies can enable new devices and applications.

Communications system using a mirror kept in outer space by electromagnetic radiation pressure

DOEpatents

Csonka, Paul L.

1981-01-01

A method and system are described for transmitting electromagnetic radiation by using a communications mirror located between about 100 kilometers and about 200 kilometers above ground. The communications mirror is kept aloft above the atmosphere by the pressure of the electromagnetic radiation which it reflects, and which is beamed at the communications mirror by a suitably constructed transmitting antenna on the ground. The communications mirror will reflect communications, such as radio, radar, or television waves up to about 1,100 kilometers away when the communications mirror is located at a height of about 100 kilometers.

Method for generating extreme ultraviolet with mather-type plasma accelerators for use in Extreme Ultraviolet Lithography

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

Hassanein, Ahmed; Konkashbaev, Isak

A device and method for generating extremely short-wave ultraviolet electromagnetic wave uses two intersecting plasma beams generated by two plasma accelerators. The intersection of the two plasma beams emits electromagnetic radiation and in particular radiation in the extreme ultraviolet wavelength. In the preferred orientation two axially aligned counter streaming plasmas collide to produce an intense source of electromagnetic radiation at the 13.5 nm wavelength. The Mather type plasma accelerators can utilize tin, or lithium covered electrodes. Tin, lithium or xenon can be used as the photon emitting gas source.

[Application of low-intensity and ultrahigh frequency electromagnetic radiation in modern pediatric practice].

PubMed

Azov, N A; Azova, E A

2009-01-01

The use of an Amfit-0,2/10-01 apparatus generating low-intensity ultrahigh frequency (UHF) electromagnetic radiation improved efficiency of therapy of sick children. This treatment allowed to reduce the frequency of intake of anesthetics in the post-operative period, correct metabolic disorders in children with type 1 diabetes mellitus, reduce severity of diabetic nephropathy and polyneuropathy, prevent formation of fresh foci of lipoid necrobiosis. The results of the study indicate that the use of low-intensity UHF electromagnetic radiation may be recommended for more extensive introduction into practical clinical work of pediatric endocrinologists and surgeons.

[The ultrastructure of Leydig cells under the influence of drinking mineral water and electromagnetic radiation under the stress conditions in the rats].

PubMed

Geniatulina, M S; Korolev, Yu N; Nikulina, L A

The objective of the present study was elucidate the peculiar features of low-intensity electromagnetic radiation (LI EMR) and mineral water (MW) on the ultrastructure of rat Leydig cells under conditions of immobilization stress. The experiments were carried out on outbred male rats with the use of electron microscopy. It has been demonstrated that the prophylactic consumption of drinking sulfate-containing mineral water and the application low-intensity electromagnetic radiation (with the flow power density of 1 mcW/cm2 and frequency around 1,000 Hz) or the combination of these two modalities under conditions of immobilization stress reduced the degree of ultrastructural derangement in the rat Leydig cells and stimulated the development of regenerative processes. In the cases of the single-factor impact, drinking mineral water exerted more pronounced action than low-intensity electromagnetic radiation on mitochondrial regeneration. In case of the simultaneous application of the two factors their protective action on the Leydig cells was much more conspicuous than that of either of them applied alone. It is concluded that drinking sulfate-containing mineral water in combination with the application of low-intensity electromagnetic radiation enhances resistance of the rat Leydig cells to stress.

Extremal black holes, Stueckelberg scalars and phase transitions

NASA Astrophysics Data System (ADS)

Marrani, Alessio; Miskovic, Olivera; Leon, Paula Quezada

2018-02-01

We calculate the entropy of a static extremal black hole in 4D gravity, non-linearly coupled to a massive Stueckelberg scalar. We find that the scalar field does not allow the black hole to be magnetically charged. We also show that the system can exhibit a phase transition due to electric charge variations. For spherical and hyperbolic horizons, the critical point exists only in presence of a cosmological constant, and if the scalar is massive and non-linearly coupled to electromagnetic field. On one side of the critical point, two extremal solutions coexist: Reissner-Nordström (A)dS black hole and the charged hairy (A)dS black hole, while on the other side of the critical point the black hole does not have hair. A near-critical analysis reveals that the hairy black hole has larger entropy, thus giving rise to a zero temperature phase transition. This is characterized by a discontinuous second derivative of the entropy with respect to the electric charge at the critical point. The results obtained here are analytical and based on the entropy function formalism and the second law of thermodynamics.

Electromagnetic transponders indicate prostate size increase followed by decrease during the course of external beam radiation therapy.

PubMed

King, Benjamin L; Butler, Wayne M; Merrick, Gregory S; Kurko, Brian S; Reed, Joshua L; Murray, Brian C; Wallner, Kent E

2011-04-01

Real-time image guidance enables more accurate radiation therapy by tracking target movement. This study used transponder positions to monitor changes in prostate volume that may be a source of dosimetric and target inaccuracy. Twenty-four men with biopsy-proven T1c-T3a prostate cancer each had three electromagnetic transponders implanted transperineally. Their coordinates were recorded by the Calypso system, and the perimeter of the triangle formed by the transponders was used to calculate prostate volumes at sequential time points throughout the course of radiation therapy to a dose of 81 Gy in 1.8-Gy fractions. There was a significant decrease in mean prostate volume of 10.9% from the first to the final day of radiation therapy. The volume loss did not occur monotonically but increased in most patients (75%) during the first several weeks to a median maximum on Day 7. The volume increased by a mean of 6.1% before decreasing by a mean maximum difference of 18.4% to nadir (p < 0.001 for both increase and decrease). Glandular shrinkage was asymmetric, with the apex to right base dimension varying more than twice that of the lateral dimension. For all dimensions, the mean change was <0.5 cm. Real-time transponder positions indicated a volume increase during the initial days of radiation therapy and then significant and asymmetric shrinkage by the final day. Understanding and tracking volume fluctuations of the prostate during radiation therapy can help real-time imaging technology perform to its fullest potential. Copyright © 2011 Elsevier Inc. All rights reserved.

A model-dependent approach to the non-relativistic Lamb shift

NASA Astrophysics Data System (ADS)

Diaz-Valdes, J. F.; Bruce, S. A.

2018-02-01

The precise observation of the Lamb shift, between the 2s_{1/2} and 2p_{1/2} levels in hydrogen, was a genuine motivation for the development of modern quantum electrodynamics. According to Dirac theory, the 2s_{1/2} and 2p_{1/2} levels should have equal energies. However, "radiative corrections" due to the interaction between the atomic electron and the vacuum, shift the 2s_{1/2} level higher in energy by around 4.37493× 10^{-6} eV or 2π\\hbar× 1057.85 MHz relative to the 2p_{1/2} level. The measurement of Lamb and Retherford provided the stimulus for renormalization theory which has been so successful in handling troublesome divergences. The Lamb shift is still a central theme in atomic physics. W.E. Lamb was the first to see that this tiny shift, so elusive and hard to measure, would clarify in a fundamental way our thinking about particles and fields. In this article, the Lamb shift for the 2 s energy level in hydrogen is assessed for three different electron models by using the variational principle. It is then verified that this shift arises mostly from the interaction of a bound electron with the zero-point fluctuations of the free electromagnetic field (Welton's interpretation). We briefly comment on the construct validity of the proposed electron models.

40 CFR 86.1333 - Transient test cycle generation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... zero percent speeds, zero percent torque points, but may be engaged up to two points preceding a non-zero point, and may be engaged for time segments with zero percent speed and torque points of durations...

Phase-transition Theory of Kerr Black Holes in the Electromagnetic Field

NASA Astrophysics Data System (ADS)

Liao, Yi; Gong, Xiao-Bo; Wu, Jian-Sheng

2017-02-01

For a Kerr black hole (KBH) with spin J and mass M in a steady electromagnetic field, a special Wald vacuum solution (WVS) has been found in the case of the no-source uniform field. For WVS, the Meissner effect (ME) occurs only in the the extreme KBH, where M2/J = 1, in this case, the magnetic field is totally excluded from the event horizon (EH) of KBH. However, WVS does not consider the Hawking radiation (HR) but treats KBH as an absolutely black body. If HR is added , researchers believe that the condition is not so restricted and it is possible for ME to occur in the less-extreme case. How less is the “less-extreme case”? This paper tries to answer this question. Since the Hawking temperature TH of KBH defined by HR is proportional to the surface gravity κ at the EH, this question is actually about the so-called existence/non-existence of ME (ME/NME) or superconducting phase transition. In this paper, we study the connection between the superconductivity of KBH-EH and the existence of Weyl fermion. Using thermodynamic formulas and the KBH state equation, we prove that the inherent-parameter condition for ME to occur is {M}2/J≤slant {ɛ }c=1.5 in force-free fields whether it be in the simple axisymmetric vacuum zero source case or in the non-zero source case, which can be described by the nonlinear Grad-Shafranov equation. We suggest that this is a second-order phase transition and calculate the critical exponents δ = 1 and η = 1/2 for the specific heat diverging at constant J.

Nanocomposites for electromagnetic radiation protection

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

Petrunin, V. F., E-mail: VFPetrunin@mephi.ru

Specific features that characterize nanoparticles and which are due to their small size and allow one to enhance the interaction between the electromagnetic radiation and nanostructured materials and to develop the effective protection of man and equipment against harmful uncontrolled radiation are reported. Examples of the development of nanocomposite radar absorbing materials that can be used for protection of man and equipment are presented.

Fast Atom Ionization in Strong Electromagnetic Radiation

NASA Astrophysics Data System (ADS)

Apostol, M.

2018-05-01

The Goeppert-Mayer and Kramers-Henneberger transformations are examined for bound charges placed in electromagnetic radiation in the non-relativistic approximation. The consistent inclusion of the interaction with the radiation field provides the time evolution of the wavefunction with both structural interaction (which ensures the bound state) and electromagnetic interaction. It is shown that in a short time after switching on the high-intensity radiation the bound charges are set free. In these conditions, a statistical criterion is used to estimate the rate of atom ionization. The results correspond to a sudden application of the electromagnetic interaction, in contrast with the well-known ionization probability obtained by quasi-classical tunneling through classically unavailable non-stationary states, or other equivalent methods, where the interaction is introduced adiabatically. For low-intensity radiation the charges oscillate and emit higher-order harmonics, the charge configuration is re-arranged and the process is resumed. Tunneling ionization may appear in these circumstances. Extension of the approach to other applications involving radiation-induced charge emission from bound states is discussed, like ionization of molecules, atomic clusters or proton emission from atomic nuclei. Also, results for a static electric field are included.

Minimization of the Total Depth of Internal Saw-Tooth Reliefs of a Two-Layer Relief-Phase Diffraction Microstructure

NASA Astrophysics Data System (ADS)

Greisukh, G. I.; Danilov, V. A.; Stepanov, S. A.; Antonov, A. I.; Usievich, B. A.

2018-01-01

Results of studying the possibility to decrease the total depth of reliefs of a two-layer microstructure having two internal saw-tooth microreliefs reducing the dependence of the diffraction efficiency of the microstructure on the radiation wavelength and angle of radiation incidence on the microstructure are presented. These results allow one to minimize the complexity of obtaining optimum microrelief depths depending on requirements applicable to the diffraction optical element in the framework of the electromagnetic-diffraction theory. Optimum depths provide in the specified spectral range and interval of angles of radiation incidence the maximum possible (for the chosen width of the narrowest zone of the saw-tooth microrelief) value of the diffraction efficiency at the point of its minimum.

Electromagnetic Radiation from Corona Discharges.

DTIC Science & Technology

1977-01-25

a 3 MHz bandwidth to cover frequencies below I GHz. Various TWT preamplifiers were used to increase the system gain. R-f energy from the corona point...100 MHz CENTER FREQUENCYr 0.05 mv/div 5 ps/div FIGURE 11. DETECTED I.F SIGNALS RECEIVED FROM A 20’ PIPE IN CORONA 29 the broadband impulsive background...noise at sea, with a secondary objective of measuring background noise at narrower bandwidths on a swept frequency basis. The broadband measurement

New radiation protection calibration facility at CERN.

PubMed

Brugger, Markus; Carbonez, Pierre; Pozzi, Fabio; Silari, Marco; Vincke, Helmut

2014-10-01

The CERN radiation protection group has designed a new state-of-the-art calibration laboratory to replace the present facility, which is >20 y old. The new laboratory, presently under construction, will be equipped with neutron and gamma sources, as well as an X-ray generator and a beta irradiator. The present work describes the project to design the facility, including the facility placement criteria, the 'point-zero' measurements and the shielding study performed via FLUKA Monte Carlo simulations. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

University Physics Students' Use of Models in Explanations of Phenomena Involving Interaction between Metals and Electromagnetic Radiation.

ERIC Educational Resources Information Center

Redfors, Andreas; Ryder, Jim

2001-01-01

Examines third year university physics students' use of models when explaining familiar phenomena involving interaction between metals and electromagnetic radiation. Concludes that few students use a single model consistently. (Contains 27 references.) (DDR)

The ELF in Your Library.

ERIC Educational Resources Information Center

McKimmie, Tim; Smith, Jeanette

1994-01-01

Presents an overview of the issues related to extremely low frequency (ELF) radiation from computer video display terminals. Highlights include electromagnetic fields; measuring ELF; computer use in libraries; possible health effects; electromagnetic radiation; litigation and legislation; standards and safety; and what libraries can do. (Contains…

Total electron count variability and stratospheric ozone effects on solar backscatter and LWIR emissions

DTIC Science & Technology

2017-03-10

electromagnetic radiation that propagates through a planetary atmosphere. These codes vary in the extent of their scope, incorporated models, and derived...emissive properties of the atmosphere. The propagation of electromagnetic radiation is affected by the scattering and absorption by both air molecules...Mie theory is the collection of the Mie solutions and methods to Maxwell’s Equations, which 35 describe how electromagnetic waves are scattered by

[Organization of monitoring of electromagnetic radiation in the urban environment].

PubMed

Savel'ev, S I; Dvoeglazova, S V; Koz'min, V A; Kochkin, D E; Begishev, M R

2008-01-01

The authors describe new current approaches to monitoring the environment, including the sources of electromagnetic radiation and noise. Electronic maps of the area under study are shown to be made, by constructing the isolines or distributing the actual levels of controlled factors. These current approaches to electromagnetic and acoustic monitoring make it possible to automate a process of measurements, to analyze the established situation, and to simplify the risk controlling methodology.

[Antitumor effect of low-intensity extremely high-frequency electromagnetic radiation on a model of solid Ehrlich carcinoma].

PubMed

Gapeev, A B; Shved, D M; Mikhaĭlik, E N; Korystov, Iu N; Levitman, M Kh; Shaposhnikova, V V; Sadovnikov, V B; Alekhin, A I; Goncharov, N G; Chemeris, N K

2009-01-01

The influence of different exposure regimes of low-intensity extremely high-frequency electromagnetic radiation on the growth rate of solid Ehrlich carcinoma in mice has been studied. It was shown that, at an optimum repetition factor of exposure (20 min daily for five consecutive days after the tumor inoculation), there is a clearly pronounced frequency dependence of the antitumor effect. The analysis of experimental data indicates that the mechanisms of antitumor effects of the radiation may be related to the modification of the immune status of the organism. The results obtained show that extremely high-frequency electromagnetic radiation at a proper selection of exposure regimes can result in distinct and stable antitumor effects.

Formation of Twisted Elephant Trunks in the Rosette Nebula

NASA Astrophysics Data System (ADS)

Carlqvist, P.; Gahm, G. F.; Kristen, H.

New observations show that dark elephant trunks in the Rosette nebula are often built up by thin filaments. In several of the trunks the filaments seem to form a twisted pattern. This pattern is hard to reconcile with current theory. We propose a new model for the formation of twisted elephant trunks in which electromagnetic forces play an important role. The model considers the behaviour of a twisted magnetic filament in a molecular cloud, where a cluster of hot stars has been recently born. As a result of stellar winds, and radiation pressure, electromagnetic forces, and inertia forces part of the filament can develop into a double helix pointing towards the stars. The double helix represents the twisted elephant trunk. A simple analogy experiment visualizes and supports the trunk model.

[A Compact Source of Terahertz Radiation Based on Interaction of Electrons in à Quantum Well with an Electromagnetic Wave of a Corrugated Waveguide].

PubMed

Shchurova, L Yu; Namiot, V A; Sarkisyan, D R

2015-01-01

Coherent sources of electromagnetic waves in the terahertz frequency range are very promising for various applications, including biology and medicine. In this paper we propose a scheme of a compact terahertz source, in which terahertz radiation is generated due to effective interaction of electrons in a quantum well with an electromagnetic wave of a corrugated waveguide. We have shown that the generation of electromagnetic waves with a frequency of 1012 sec(-1) and an output power of up to 25. mW is possible in the proposed scheme.

Extraordinary electromagnetic transmission by antenna arrays and frequency selective surfaces having compound unit cells with dissimilar elements

DOEpatents

Loui, Hung; Strassner, II, Bernd H.

2018-03-20

The various embodiments presented herein relate to extraordinary electromagnetic transmission (EEMT) to enable multiple inefficient (un-matched) but coupled radiators and/or apertures to radiate and/or pass electromagnetic waves efficiently. EEMT can be utilized such that signal transmission from a plurality of antennas and/or apertures occurs at a transmission frequency different to transmission frequencies of the individual antennas and/or aperture elements. The plurality of antennas/apertures can comprise first antenna/aperture having a first radiating area and material(s) and second antenna/aperture having a second radiating area and material(s), whereby the first radiating/aperture area and second radiating/aperture area can be co-located in a periodic compound unit cell. Owing to mutual coupling between the respective antennas/apertures in their arrayed configuration, the transmission frequency of the array can be shifted from the transmission frequencies of the individual elements. EEMT can be utilized for an array of evanescent of inefficient radiators connected to a transmission line(s).

On the role of radiation and dimensionality in predicting flow opposed flame spread over thin fuels

NASA Astrophysics Data System (ADS)

Kumar, Chenthil; Kumar, Amit

2012-06-01

In this work a flame-spread model is formulated in three dimensions to simulate opposed flow flame spread over thin solid fuels. The flame-spread model is coupled to a three-dimensional gas radiation model. The experiments [1] on downward spread and zero gravity quiescent spread over finite width thin fuel are simulated by flame-spread models in both two and three dimensions to assess the role of radiation and effect of dimensionality on the prediction of the flame-spread phenomena. It is observed that while radiation plays only a minor role in normal gravity downward spread, in zero gravity quiescent spread surface radiation loss holds the key to correct prediction of low oxygen flame spread rate and quenching limit. The present three-dimensional simulations show that even in zero gravity gas radiation affects flame spread rate only moderately (as much as 20% at 100% oxygen) as the heat feedback effect exceeds the radiation loss effect only moderately. However, the two-dimensional model with the gas radiation model badly over-predicts the zero gravity flame spread rate due to under estimation of gas radiation loss to the ambient surrounding. The two-dimensional model was also found to be inadequate for predicting the zero gravity flame attributes, like the flame length and the flame width, correctly. The need for a three-dimensional model was found to be indispensable for consistently describing the zero gravity flame-spread experiments [1] (including flame spread rate and flame size) especially at high oxygen levels (>30%). On the other hand it was observed that for the normal gravity downward flame spread for oxygen levels up to 60%, the two-dimensional model was sufficient to predict flame spread rate and flame size reasonably well. Gas radiation is seen to increase the three-dimensional effect especially at elevated oxygen levels (>30% for zero gravity and >60% for normal gravity flames).

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.

Rockburst Disaster Prediction of Isolated Coal Pillar by Electromagnetic Radiation Based on Frictional Effect

PubMed Central

Zhao, Tongbin; Yin, Yanchun; Xiao, Fukun; Tan, Yunliang; Zou, Jianchao

2014-01-01

Based on the understanding that charges generated during coal cracking are due to coal particle friction, a microstructure model was developed by considering four different variation laws of friction coefficient. Firstly, the frictional energy release of coal sample during uniaxial compressive tests was investigated and discussed. Then electromagnetic radiation method was used to predict the potential rockburst disaster in isolated coal pillar mining face, Muchengjian Colliery. The results indicate that the friction coefficient of coal particles decreases linearly with the increase of axial loading force. In predicting the strain-type rockburst, the high stress state of coal must be closely monitored. Field monitoring shows that electromagnetic radiation signal became abnormal before the occurrence of rockburst during isolated coal pillar mining. Furthermore, rockburst tends to occur at the early and ending stages of isolated coal pillar extraction. Mine-site investigation shows the occurrence zone of rockburst is consistent with the prediction, proving the reliability of the electromagnetic radiation method to predict strain-type rockburst disaster. PMID:25054186

Rockburst disaster prediction of isolated coal pillar by electromagnetic radiation based on frictional effect.

PubMed

Zhao, Tongbin; Yin, Yanchun; Xiao, Fukun; Tan, Yunliang; Zou, Jianchao

2014-01-01

Based on the understanding that charges generated during coal cracking are due to coal particle friction, a microstructure model was developed by considering four different variation laws of friction coefficient. Firstly, the frictional energy release of coal sample during uniaxial compressive tests was investigated and discussed. Then electromagnetic radiation method was used to predict the potential rockburst disaster in isolated coal pillar mining face, Muchengjian Colliery. The results indicate that the friction coefficient of coal particles decreases linearly with the increase of axial loading force. In predicting the strain-type rockburst, the high stress state of coal must be closely monitored. Field monitoring shows that electromagnetic radiation signal became abnormal before the occurrence of rockburst during isolated coal pillar mining. Furthermore, rockburst tends to occur at the early and ending stages of isolated coal pillar extraction. Mine-site investigation shows the occurrence zone of rockburst is consistent with the prediction, proving the reliability of the electromagnetic radiation method to predict strain-type rockburst disaster.

The electric field changes and UHF radiations caused by the triggered lightning in Japan

NASA Technical Reports Server (NTRS)

Kawasaki, Zen-Ichiro; Kanao, Tadashi; Matsuura, Kenji; Nakano, Minoru; Horii, Kenji; Nakamura, Koichi

1991-01-01

In the rocket triggered lightning experiment of fiscal 1989, researchers observed electromagnetic field changes and UHF electromagnetic radiation accompanying rocket triggered lightning. It was found that no rapid changes corresponding to the return stroke of natural lightning were observed in the electric field changes accompanying rocket triggered lightning. However, continuous currents were present. In the case of rocket triggered lightning to the tower, electromagnetic field changes corresponding to the initiation of triggered lightning showed a bipolar pulse of a relatively large amplitude. In contrast, the rocket triggered lightning to the ground did not have such a bipolar pulse. The UHF radiation accompanying the rocket triggered lightning preceded the waveform portions corresponding to the first changes in electromagnetic fields. The number of isolated pulses in the UHF radiation showed a correlation with the time duration from rocket launching up to triggered lightning. The time interval between consecutive isolated pulses tended to get shorter with the passage of time, just like the stepped leaders of natural lightning.

Mini Array for TLE Detection

NASA Astrophysics Data System (ADS)

Fullekrug, M.; Liu, Z.; Koh, K.; Mezentsev, A.; Pedeboy, S.; Soula, S.; Sugier, J.; Enno, S. E.; Rycroft, M. J.

2016-12-01

Transient Luminous Events (TLEs) can generate electromagnetic radiation at frequencies 100 kHz (Qin et al., 2012, Fullekrug et al., 2013) and <1 kHz (Pasko et al., GRL, 1998, Cummer et al., GRL, 1998)as a result of the splitting and exponential growth of streamer discharges (Pasko, JGR, 2010, McHarg, JGR, 2010). The electromagnetic radiation results from the coherent superposition of the very weak signalsfrom thousands of small scale streamer discharges at 40 km height for frequencies 100 kHz and at 80 km height for frequencies <1 kHz. It seems therefore plausible that TLEs can also generate electromagnetic waves at intermediate heights, e.g. 60 km with frequencies between 1-100 kHz, e.g., 10 kHz. However, this frequency range is dominated by the powerful electromagnetic radiation from return strokes and it is hence commonly thought that this radiation can not easily be detectedwith single radio receivers. This study proposes to search for electromagnetic radiation from TLEsabove thunderclouds by use of a mini array that has the ability to determine the elevation angle toward the radiation source. Mini arrays with small apertures are used for infrasonic and seismic studies to determine source mechanisms and properties of the medium through which the waves propagate. For the detection of electromagneticradiation, the array processing is adapted for the fast propagationat the speed of light. Here we report for the first time the detection and mapping of distant lightning strokes in the sky with a mini array located near Bath in the UK. The array has a baseline to wavelength ratio 4.2 10^{-2} to record electromagnetic waves from 2-18 kHz. It is found that the mini array detects 69 lightning strokes per second from cloud-to-ground and in-cloud discharges, even though the parent thunderstorms are 900-1,100 km away and a rigorous selection criterion based on the spatial coherency of the electromagnetic source field across the array is used. About 14% of the lightning strokes appear at larger elevation angles in the sky than the remaining 86% of lightning strokes as the result of birefringent subionospheric wave propagation attributed to ordinary and extra-ordinary waves. These results imply that mini arrays can be used to detect electromagnetic radiation from TLEs above thunderclouds in different frequency ranges.

Optimized point dose measurement for monitor unit verification in intensity modulated radiation therapy using 6 MV photons by three different methodologies with different detector-phantom combinations: A comparative study

PubMed Central

Sarkar, Biplab; Ghosh, Bhaswar; Sriramprasath; Mahendramohan, Sukumaran; Basu, Ayan; Goswami, Jyotirup; Ray, Amitabh

2010-01-01

The study was aimed to compare accuracy of monitor unit verification in intensity modulated radiation therapy (IMRT) using 6 MV photons by three different methodologies with different detector phantom combinations. Sixty patients were randomly chosen. Zero degree couch and gantry angle plans were generated in a plastic universal IMRT verification phantom and 30×30×30 cc water phantom and measured using 0.125 cc and 0.6 cc chambers, respectively. Actual gantry and couch angle plans were also measured in water phantom using 0.6 cc chamber. A suitable point of measurement was chosen from the beam profile for each field. When the zero-degree gantry, couch angle plans and actual gantry, couch angle plans were measured by 0.6 cc chamber in water phantom, the percentage mean difference (MD) was 1.35%, 2.94 % and Standard Deviation (SD) was 2.99%, 5.22%, respectively. The plastic phantom measurements with 0.125 cc chamber Semiflex ionisation chamber (SIC) showed an MD=4.21% and SD=2.73 %, but when corrected for chamber-medium response, they showed an improvement, with MD=3.38 % and SD=2.59 %. It was found that measurements with water phantom and 0.6cc chamber at gantry angle zero degree showed better conformity than other measurements of medium-detector combinations. Correction in plastic phantom measurement improved the result only marginally, and actual gantry angle measurement in a flat- water phantom showed higher deviation. PMID:20927221

Antenna-coupled unbiased detectors for LW-IR regime

NASA Astrophysics Data System (ADS)

Tiwari, Badri Nath

At room temperature (300K), the electromagnetic (EM) radiation emitted by humans and other living beings peaks mostly in the long-wavelength infrared (LW-IR) regime. And since the atmosphere shows relatively little absorption in this band, applications such as target detection, tracking, active homing, and navigation in autonomous vehicles extensively use the LW-IR frequency range. The present research work is focused on developing antenna-based, uncooled, and unbiased detectors for the LW-IR regime. In the first part of this research, antenna-coupled metal-oxide-metal diodes (ACMOMD) are investigated. In response to the EM radiation, high-frequency antenna currents are induced in the antenna. An asymmetric-barrier Al-Al2O3-Pt MOM diode rectifies the antenna currents. Two different types of fabrication processes have been developed for ACMOMDs namely one-step lithography and two-step lithography. The major drawbacks of MOM-based devices include hard-to-control fabrication processes, generally very high zero-biased resistances, and vulnerability to electrostatic discharges, leading to unstable electrical characteristics. The second part of this research focuses on the development of unbiased LW-IR sensors based on the Seebeck effect. If two different metals are joined together at one end and their other ends are open-circuited, and if a non-zero temperature difference exists between the joined end and the open ends, then a non-zero open-circuit voltage can be measured between the open ends of the wires. Based on this effect, we have developed antenna-coupled nano-thermocouples (ACNTs) in which radiation-induced antenna currents produce polarization-dependent heating of the joined end of the two metals whereas the open ends remain at substrate temperature. This polarization-dependent heating induces polarization-dependent temperature difference between the joined end and the open ends of the metals leading to a polarization-dependent open-circuit voltage between the open ends of the metals. A CW CO2 laser tuned at 10.6 mum wavelength has been used for infrared characterization of these sensors. For these sensors, average responsivity of 22.7 mV/W, signal-to-noise (SNR) ratio of 29 dB, noise equivalent power (NEP) of 1.55 nW, and specific detectivity (D*) of 1.77x105 cm. Hz .W--1 were measured. ACNTs are expected to operate at frequencies much beyond 400 KHz. The third part of this research focuses on the effect of DC read-out interconnects on polarization characteristics of the planar dipole antennas. Different geometries of the interconnects present different electromagnetic boundary conditions to the antenna, and thus affect the far-field polarization characteristics of the antenna. Four designs of DC read-out interconnects are fabricated and their polarization-dependent IR responses are experimentally measured. The High Frequency Structure Simulator (HFSS) from ANSYS is used to simulate the polarization characteristics of the antenna with different read-out geometries.

Four-body calculation of {sup 12}C(α, γ){sup 16}O radiative capture reaction at stellar energies

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

Sadeghi, H., E-mail: H-Sadeghi@Araku.ac.ir; Firoozabadi, M. M.

2016-01-15

On the basis of the four-alphamodel, the {sup 12}C(α, γ){sup 16}Oradiative capture process is investigated by using the four-body Faddeev–Yakubovsky equations as well as the two- and three-body electromagnetic currents. The present calculation is an application of our current conservation realistic potentials method for the {sup 12}C(α, γ){sup 16}Oradiative capture process. This work clears the way formore refinedmodels of radiative capture based on two- and three-body realistic potentials and current conservation. The calculation is carried out by considering the {sup 4}He + {sup 12}C (1 + 3) and the {sup 8}Be + {sup 8}Be (2 + 2) subamplitudes, respectively. Radiativemore » capture {sup 12}C(α, γ){sup 16}Oreaction is one of the most important reactions in nuclear astrophysics. For this reaction, the electric dipole transitions between states with the same isospin are forbidden in the first order. Because the state 1{sup +} and 0{sup +} ground state nuclei {sup 16}O have zero isospin, thus the electric dipole radiations are not at the first order between two levels and electric dipole radiation will be the second order and electric dipole radiation is the same order as the electric quadrupole radiation. Therefore, we must consider the effects of both radiations. In comparison with other theoretical methods and available experimental data, good agreement is achieved for the E{sub 1} and E{sub 2} contribution to the cross section and the astrophysical S factor for this process.« less

Influence of gravitation on the propagation of electromagnetic radiation

NASA Technical Reports Server (NTRS)

Mashhoon, B.

1975-01-01

The existence of a general helicity-rotation coupling is demonstrated for electromagnetic waves propagating in the field of a slowly rotating body and in the Goedel universe. This coupling leads to differential focusing of circularly polarized radiation by a gravitational field which is detectable for a rapidly rotating collapsed body. The electromagnetic perturbations and their frequency spectrum are given for the Goedel universe. The spectrum of frequencies is bounded from below by the characteristic rotation frequency of the Goedel universe. If the universe were rotating, the differential focusing effect would be extremely small due to the present upper limit on the anisotropy of the microwave background radiation.

Does electromagnetic radiation accelerate galactic cosmic rays

NASA Technical Reports Server (NTRS)

Eichler, D.

1977-01-01

The 'reactor' theories of Tsytovich and collaborators (1973) of cosmic-ray acceleration by electromagnetic radiation are examined in the context of galactic cosmic rays. It is shown that any isotropic synchrotron or Compton reactors with reasonable astrophysical parameters can yield particles with a maximum relativistic factor of only about 10,000. If they are to produce particles with higher relativistic factors, the losses due to inverse Compton scattering of the electromagnetic radiation in them outweigh the acceleration, and this violates the assumptions of the theory. This is a critical restriction in the context of galactic cosmic rays, which have a power-law spectrum extending up to a relativistic factor of 1 million.

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.

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...

Metronidazole as a protector of cells from electromagnetic radiation of extremely high frequencies

NASA Astrophysics Data System (ADS)

Kuznetsov, Pavel E.; Malinina, Ulia A.; Popyhova, Era B.; Rogacheva, Svetlana M.; Somov, Alexander U.

2006-08-01

It is well known that weak electromagnetic fields of extremely high frequencies cause significant modification of the functional status of biological objects of different levels of organization. The aim of the work was to study the combinatory effect of metronidazole - the drug form of 1-(2'hydroxiethil)-2-methil-5-nitroimidazole - and electromagnetic radiation of extremely high frequencies (52...75 GHz) on the hemolytic stability of erythrocytes and hemotaxis activity of Infusoria Paramecium caudatum.

INDEX OF PUBLICATIONS ON BIOLOGICAL EFFECTS OF ELECTROMAGNETIC RADIATION (0-100 GHZ)

EPA Science Inventory

Considerable research effort has been made into the biological effects of electro-magnetic radiation over the frequency range of 0-100 GHz. This work intensified since 1966 when occupational exposure guidelines were made by American Standards Institute - C95.9. During this period...

Orbital dynamics of high area-to-mass ratio spacecraft with J2 and solar radiation pressure for novel Earth observation and communication services

NASA Astrophysics Data System (ADS)

Colombo, Camilla; Lücking, Charlotte; McInnes, Colin R.

2012-12-01

This paper investigates the effect of planetary oblateness and solar radiation pressure on the orbits of high area-to-mass spacecraft. A planar Hamiltonian model shows the existence of equilibrium orbits with the orbit apogee pointing towards or away from the Sun. These solutions are numerically continued to non-zero inclinations and considering the obliquity of the ecliptic plane relative to the equator. Quasi-frozen orbits are identified in eccentricity, inclination and the angle between the Sun-line and the orbit perigee. The long-term evolution of these orbits is then verified through numerical integration. A set of 'heliotropic' orbits with apogee pointing in the direction of the Sun is proposed for enhancing imaging and telecommunication on the day side of the Earth. The effects of J2 and solar radiation pressure are exploited to obtain a passive rotation of the apsides line following the Sun; moreover the effect of solar radiation pressure enables such orbits at higher eccentricities with respect to the J2 only case.

The impact of electromagnetic radiation of different parameters on platelet oxygen metabolism - in vitro studies.

PubMed

Lewicka, Małgorzata; Henrykowska, Gabriela A; Pacholski, Krzysztof; Szczęsny, Artur; Dziedziczak-Buczyńska, Maria; Buczyński, Andrzej

2015-01-01

Electromagnetic radiation emitted by a variety of devices, e.g. cell phones, computers and microwaves, interacts with the human body in many ways. Research studies carried out in the last few decades have not yet resolved the issue of the effect of this factor on the human body and many questions are left without an unequivocal answer. Various biological and health-related effects have not been fully recognized. Thus further studies in this area are justified. A comparison of changes within catalase enzymatic activity and malondialdehyde concentration arising under the influence of the electromagnetic radiation emitted by car electronics, equipment used in physiotherapy and LCD monitors. The suspension of human blood platelets at a concentration of 1 × 109/0.001 dm 3, obtained from whole blood by manual apheresis, was the study material. Blood platelets were exposed to an electromagnetic field for 30 min in a laboratory stand designed for the reconstruction of the electromagnetic radiation generated by car electronics, physiotherapy equipment and LCD monitors. The changes in catalase activity and malondialdehyde concentration were investigated after the exposure and compared to the control values (unexposed material). An increase in catalase activity and malondialdehyde concentration was observed after 30 min exposure of platelets to EMF regardless of the radiation source. The most significant changes determining the degree of oxidative stress were observed after exposure to the EMF generated by car electronics. The low frequency electromagnetic fields generated by car electronics, physiotherapy equipment and LCD monitors may be a cause of oxidative stress in the human body and may lead to free radical diseases.

SU-F-J-146: Experimental Validation of 6 MV Photon PDD in Parallel Magnetic Field Calculated by EGSnrc

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

Ghila, A; Steciw, S; Fallone, B

Purpose: Integrated linac-MR systems are uniquely suited for real time tumor tracking during radiation treatment. Understanding the magnetic field dose effects and incorporating them in treatment planning is paramount for linac-MR clinical implementation. We experimentally validated the EGSnrc dose calculations in the presence of a magnetic field parallel to the radiation beam travel. Methods: Two cylindrical bore electromagnets produced a 0.21 T magnetic field parallel to the central axis of a 6 MV photon beam. A parallel plate ion chamber was used to measure the PDD in a polystyrene phantom, placed inside the bore in two setups: phantom top surfacemore » coinciding with the magnet bore center (183 cm SSD), and with the magnet bore’s top surface (170 cm SSD). We measured the field of the magnet at several points and included the exact dimensions of the coils to generate a 3D magnetic field map in a finite element model. BEAMnrc and DOSXYZnrc simulated the PDD experiments in parallel magnetic field (i.e. 3D magnetic field included) and with no magnetic field. Results: With the phantom surface at the top of the electromagnet, the surface dose increased by 10% (compared to no-magnetic field), due to electrons being focused by the smaller fringe fields of the electromagnet. With the phantom surface at the bore center, the surface dose increased by 30% since extra 13 cm of air column was in relatively higher magnetic field (>0.13T) in the magnet bore. EGSnrc Monte Carlo code correctly calculated the radiation dose with and without the magnetic field, and all points passed the 2%, 2 mm Gamma criterion when the ion chamber’s entrance window and air cavity were included in the simulated phantom. Conclusion: A parallel magnetic field increases the surface and buildup dose during irradiation. The EGSnrc package can model these magnetic field dose effects accurately. Dr. Fallone is a co-founder and CEO of MagnetTx Oncology Solutions (under discussions to license Alberta bi-planar linac MR for commercialization).« less

[Reparative Osteogenesis and Angiogenesis in Low Intensity Electromagnetic Radiation of Ultra-High Frequency].

PubMed

Iryanov, Y M; Kiryanov, N A

2015-01-01

Non-drug correction of reparative bone tissue regeneration in different pathological states - one of the most actual problems of modern medicine. Our aim was to conduct morphological analysis of the influence of electromagnetic radiation of ultra-high frequency and low intensity on reparative osteogenesis and angiogenesis in fracture treatment under transosseous osteosynthesis. A controlled nonrandomized study was carried out. In the experiment conducted on rats we modeled tibial fracture with reposition and fixation of the bone fragments both in control and experimental groups. In the animals of the experimental group the fracture zone was exposed to low intensity electromagnetic radiation of ultra-high frequency. Exposure simulation was performed in the control group. The operated bones were examined using radiography, light and electronic microscopy, X-ray electronic probe microanalysis. It has been established that electromagnetic radiation of ultra-high frequency sessions in fracture treatment stimulate secretory activity and degranulation of mast cells, produce microcirculatory bed vascular permeability increase, endotheliocyte migration phenotype expression, provide endovascular endothelial outgrowth formation, activate reparative osteogenesis and angiogenesis while fracture reparation becomes the one of the primary type. The full periosteal, intermediary and intraosteal bone union was defined in 28 days. Among the therapeutic benefits of electromagnetic radiation of ultra-high frequency in fracture treatment we can detect mast cell secretorv activity stimulation and endovascular anziozenesis activation.

Organo Luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

1999-01-01

A luminescent semiconductor nanocrystal compound is described which is capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation (luminescing) in a narrow wavelength band and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source (of narrow or broad bandwidth) or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The luminescent semiconductor nanocrystal compound is linked to an affinity molecule to form an organo luminescent semiconductor nanocrystal probe capable of bonding with a detectable substance in a material being analyzed, and capable of emitting electromagnetic radiation in a narrow wavelength band and/or absorbing, scattering, or diffracting energy when excited by an electromagnetic radiation source (of narrow or broad bandwidth) or a particle beam. The probe is stable to repeated exposure to light in the presence of oxygen and/or other radicals. Further described is a process for making the luminescent semiconductor nanocrystal compound and for making the organo luminescent semiconductor nanocrystal probe comprising the luminescent semiconductor nanocrystal compound linked to an affinity molecule capable of bonding to a detectable substance. A process is also described for using the probe to determine the presence of a detectable substance in a material.

Illumination and radiative cooling

DOEpatents

Fan, Shanhui; Raman, Aaswath Pattabhi; Zhu, Linxiao; Rephaeli, Eden

2018-03-20

Aspects of the present disclosure are directed to providing and/or controlling electromagnetic radiation. As may be implemented in accordance with one or more embodiments, an apparatus includes a first structure that contains an object, and a second structure that is transparent at solar wavelengths and emissive in the atmospheric electromagnetic radiation transparency window. The second structure operates with the first structure to pass light into the first structure for illuminating the object, and to radiatively cool the object while preserving the object's color.

Harmful effects of 41 and 202 MHz radiations on some body parts and tissues.

PubMed

Kumar, Vijay; Vats, R P; Pathak, P P

2008-08-01

Many types of invisible electromagnetic waves are produced in our atmosphere. When these radiations penetrate our body, electric fields are induced inside the body, resulting in the absorption of power, which is different for different body parts and also depends on the frequency of radiations. Higher power absorption may result into health problems. In this communication, effects of electromagnetic waves (EMW) of 41 and 202 MHz frequencies transmitted by the TV tower have been studied on skin, muscles, bone and fat of human. Using international standards for safe exposure limits of specific absorption rate (SAR), we have found the safe distance from TV transmission towers for two frequencies. It is suggested that transmission towers should be located away from the thickly populated areas and people should keep away from the transmission towers, as they radiate electromagnetic radiations that are harmful to some parts/tissues of body.

Realization of zero-field skyrmions with high-density via electromagnetic manipulation in Pt/Co/Ta multilayers

NASA Astrophysics Data System (ADS)

He, Min; Peng, Licong; Zhu, Zhaozhao; Li, Gang; Cai, Jianwang; Li, Jianqi; Wei, Hongxiang; Gu, Lin; Wang, Shouguo; Zhao, Tongyun; Shen, Baogen; Zhang, Ying

2017-11-01

Taking advantage of the electron-current ability to generate, stabilize, and manipulate skyrmions prompts the application of skyrmion multilayers in room-temperature spintronic devices. In this study, the robust high-density skyrmions are electromagnetically generated from Pt/Co/Ta multilayers using Lorentz transmission electron microscopy. The skyrmion density is tunable and can be significantly enhanced. Remarkably, these generated skyrmions after optimized manipulation sustain at zero field with both the in-plane current and perpendicular magnetic field being switched off. The skyrmion generation and manipulation method demonstrated in this study opens up an alternative way to engineer skyrmion-based devices. The results also provide key data for further theoretical study to discover the nature of the interaction between the electric current and different spin configurations.

A Constant-Field Interrupted Resonance System for Percutaneous Electromagnetic Measurement of Blood Flow

PubMed Central

Kolin, Alexander; Steele, James R.; Imai, James S.; Macalpin, Rex N.

1974-01-01

A combination of deformable flow probes of negligible lateral dimensions with an electronic circuit capable of providing a prolonged plateau of dB/dt = 0 and of sampling the flow signal at the end of this interval permits electromagnetic measurement of blood flow with a reliable zero base line secured by switching off the magnet. An extracorporeal magnet provides the magnetic field. The flow transducer is introduced into the vascular system percutaneously through a standard angiographic catheter by conventional technique. The idea of the current generator can be described as “principle of interrupted resonance.” The current wave form can be described as a sequence of disconnected bisected sine waves joined at the apices by horizontal current plateaus where di/dt is strictly zero. Images PMID:4275395

All-optical band engineering of gapped Dirac materials

NASA Astrophysics Data System (ADS)

Kibis, O. V.; Dini, K.; Iorsh, I. V.; Shelykh, I. A.

2017-03-01

We demonstrate theoretically that the interaction of electrons in gapped Dirac materials (gapped graphene and transition-metal dichalchogenide monolayers) with a strong off-resonant electromagnetic field (dressing field) substantially renormalizes the band gaps and the spin-orbit splitting. Moreover, the renormalized electronic parameters drastically depend on the field polarization. Namely, a linearly polarized dressing field always decreases the band gap (and, particularly, can turn the gap into zero), whereas a circularly polarized field breaks the equivalence of valleys in different points of the Brillouin zone and can both increase and decrease corresponding band gaps. As a consequence, the dressing field can serve as an effective tool to control spin and valley properties of the materials and be potentially exploited in optoelectronic applications.

Experimental observations of nonlinearly enhanced 2omega-UH electromagnetic radiation excited by steady-state colliding electron beams

NASA Technical Reports Server (NTRS)

Intrator, T.; Hershkowitz, N.; Chan, C.

1984-01-01

Counterstreaming large-diameter electron beams in a steady-state laboratory experiment are observed to generate transverse radiation at twice the upper-hybrid frequency (2omega-UH) with a quadrupole radiation pattern. The electromagnetic wave power density is nonlinearly enhanced over the power density obtained from a single beam-plasma system. Electromagnetic power density scales exponentially with beam energy and increases with ion mass. Weak turbulence theory can predict similar (but weaker) beam energy scaling but not the high power density, or the predominance of the 2omega-UH radiation peak over the omega-UH peak. Significant noise near the upper-hybrid and ion plasma frequencies is also measured, with normalized electrostatic wave energy density W(ES)/n(e)T(e) approximately 0.01.

Radiative Energy Loss by Galactic Cosmic Rays

NASA Technical Reports Server (NTRS)

Ahern, Sean C.; Norbury, John W.; Tripathi, R. K.

2002-01-01

Interactions between galactic cosmic rays and matter are a primary focus of the NASA radiation problem. The electromagnetic forces involved are for the most part well documented. Building on previous research, this study investigated the relative importance of the weak forces that occur when a cosmic ray impinges on different types of materials. For the familiar electromagnetic case, it is known that energy lost in the form of radiation is more significant than that lost via contact collisions the rate at which the energy is lost is also well understood. Similar results were derived for the weak force case. It was found that radiation is also the dominant mode of energy loss in weak force interactions and that weak force effects are indeed relatively weak compared to electromagnetic effects.

Simulation and analysis of the effect of ungrounded rectangular loop distributed parameters on TEM response

NASA Astrophysics Data System (ADS)

Shi, Zongyang; Liu, Lihua; Xiao, Pan; Geng, Zhi; Liu, Fubo; Fang, Guangyou

2018-02-01

An ungrounded loop in the shallow subsurface transient electromagnetic surveys has been studied as the transmission line model for early turn-off stage, which can accurately explicate the early turn-off current waveform inconsistency along the loop. In this paper, the Gauss-Legendre numerical integration method is proposed for the first time to simulate and analyze the transient electromagnetic (TEM) response considering the different early turn-off current waveforms along the loop. During the simulation, these integral node positions along the loop are firstly determined by solving these zero points of Legendre polynomial, then the turn-off current of each node position is simulated by using the transfer function of the transmission line. Finally, the total TEM response is calculated by using the Gauss-Legendre integral formula. In addition, the comparison and analysis between the results affected by the distributed parameters and that generated by lumped parameters are presented. It is found that the TEM responses agree well with each other after current is thoroughly switched off, while the transient responses in turn-off stage are completely different. It means that the position dependence of the early turn-off current should be introduced into the forward model during the early response data interpretation of the shallow TEM detection of the ungrounded loop. Furthermore, the TEM response simulations at four geometric symmetry points are made. It shows that early responses of different geometric symmetry points are also inconsistent. The research on the influence of turn-off current position dependence on the early response of geometric symmetry point is of great significance to guide the layout of the survey lines and the transmitter location.

Electromagnetic Fields and Public Health: Mobile Phones

MedlinePlus

... Ebola virus disease » Home / News / Fact sheets / Detail Electromagnetic fields and public health: mobile phones 8 October ... fixed antennas called base stations. Radiofrequency waves are electromagnetic fields, and unlike ionizing radiation such as X- ...

SCALING THE PHYSIOLOGICAL EFFECTS OF EXPOSURE TO RADIOFREQUENCY ELECTROMAGNETIC RADIATION: CONSEQUENCES OF BODY SIZE

EPA Science Inventory

The authors have demonstrated that a comparative analysis of the physiological effects of exposure of laboratory mammals to radiofrequency electromagnetic radiation (RFR) may be useful in predicting exposure thresholds for humans if the effect is assumed to be due only to heating...

FURTHER EVIDENCE OF AN INVERSE RELATION BETWEEN MAMMALIAN BODY MASS AND SENSITIVITY TO RADIO-FREQUENCY ELECTROMAGNETIC RADIATION

EPA Science Inventory

The principal objectives of the paper under criticism were to interrelate the effects of ambient temperature and intensity of exposure to radiofrequency electromagnetic radiation (RFR) on the activity of a single thermoregulatory effector, evaporative heat loss (EHL) and (ii) to ...

WKB solution 4×4 for electromagnetic waves in a planar magnetically anisotropic inhomogeneous layer

NASA Astrophysics Data System (ADS)

Moiseeva, Natalya Michailovna; Moiseev, Anton Vladimirovich

2018-04-01

In the paper, an oblique incidence of a plane electromagnetic wave on a planar magnetically anisotropic inhomogeneous layer is considered. We consider the case when all the components of the magnetic permeability tensor are non zero and vary with distance from the interface of media. The WKB method gives a matrix 4 × 4 solution for the projections of the electromagnetic wave fields during its propagation. The dependence of the cross-polarized components on the orientation of the anisotropic medium relative to the plane of incidence of the medium is analyzed.

Military Handbook: Management and Design Guidance Electromagnetic Radiation Hardness for Air Launched Ordnance Systems

DTIC Science & Technology

1981-01-15

system is attacted to the delivery aircraft until it Impacto a target, it is exposed to electromagnetic radiation from emitters aboard the delivery...homogeneous, isotropic, ambient medium may be a lossy dielectric. Antenna computations include cur- rent distribution, input impedance, radiation...permissible ambient interference level in the system, and when determining the expected signal-to-inter- ference ratio of the signal transmission circuits

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

[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.

Study of electromagnetic radiation pollution in an Indian city.

PubMed

Dhami, A K

2012-11-01

Electromagnetic radiation emitted by cell phone towers is a form of environmental pollution and is a new health hazard, especially to children and patients. The present studies were taken to estimate the microwave/RF pollution by measuring radiation power densities near schools and hospitals of Chandigarh city in India. The cell phone radiations were measured using a handheld portable power density meter TES 593 and specific absorption rates were estimated from the measured values. These values of electromagnetic radiation in the environment were compared with the levels at which biological system of humans and animals starts getting affected. The values were also compared with the international exposure limits set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The highest measured power density was 11.48 mW/m(2) which is 1,148% of the biological limit. The results indicated that the exposure levels in the city were below the ICNIRP limit, but much above the biological limit.

[Blocking 1800 MHz mobile phone radiation-induced reactive oxygen species production and DNA damage in lens epithelial cells by noise magnetic fields].

PubMed

Wu, Wei; Yao, Ke; Wang, Kai-jun; Lu, De-qiang; He, Ji-liang; Xu, Li-hong; Sun, Wen-jun

2008-01-01

To investigate whether the exposure to the electromagnetic noise can block reactive oxygen species (ROS) production and DNA damage of lens epithelial cells induced by 1800 MHz mobile phone radiation. The DCFH-DA method and comet assay were used respectively to detect the intracellular ROS and DNA damage of cultured human lens epithelial cells induced by 4 W/kg 1800 MHz mobile phone radiation or/and 2 muT electromagnetic noise for 24 h intermittently. 1800 MHz mobile phone radiation at 4 W/kg for 24 h increased intracellular ROS and DNA damage significantly (P<0.05). However, the ROS level and DNA damage of mobile phone radiation plus noise group were not significant enhanced (P>0.05) as compared to sham exposure group. Electromagnetic noise can block intracellular ROS production and DNA damage of human lens epithelial cells induced by 1800 MHz mobile phone radiation.

Extension of On-Surface Radiation Condition (OSRC) Theory to Full-Vector Electromagnetic Wave Scattering by Three-Dimensional Conducting, Dielectric, and Coated Targets

DTIC Science & Technology

1993-08-27

rever"_? if necessary and identify by block number) FIELD SUB- GROUP Electromagnetic wave scattering, radiation boundary -. ... conditions, finite...international engineering electromagnetics symposia and in related journals has risen from a level of less than 10 per year (published primarily by my group ) to...Rzpoxs and Non -Refereed Papers: 3, as follows- I. D. S. Katz, A. Taflove, J. P. Brooks and E. Harrigan, "Large-scale methods in computational

Hawking radiation in an electromagnetic waveguide?

PubMed

Schützhold, Ralf; Unruh, William G

2005-07-15

It is demonstrated that the propagation of electromagnetic waves in an appropriately designed waveguide is (for large wavelengths) analogous to that within a curved space-time--such as around a black hole. As electromagnetic radiation (e.g., microwaves) can be controlled, amplified, and detected (with present-day technology) much easier than sound, for example, we propose a setup for the experimental verification of the Hawking effect. Apart from experimentally testing this striking prediction, this would facilitate the investigation of the trans-Planckian problem.

Exposure to Radiofrequency Radiation Emitted from Common Mobile Phone Jammers Alters the Pattern of Muscle Contractions: an Animal Model Study.

PubMed

Rafati, A; Rahimi, S; Talebi, A; Soleimani, A; Haghani, M; Mortazavi, S M J

2015-09-01

The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects of exposure to radiofrequency (RF) radiation emitted from mobile phone jammers on the pulse height of contractions, the time interval between two subsequent contractions and the latency period of frog's isolated gastrocnemius muscle after stimulation with single square pulses of 1V (1 Hz). Frogs were kept in plastic containers in a room. Animals in the jammer group were exposed to radiofrequency (RF) radiation emitted from a common Jammer at a distance of 1m from the jammer's antenna for 2 hours while the control frogs were only sham exposed. Then animals were sacrificed and isolated gastrocnemius muscles were exposed to on/off jammer radiation for 3 subsequent 10 minute intervals. Isolated gastrocnemius muscles were attached to the force transducer with a string. Using a PowerLab device (26-T), the pattern of muscular contractions was monitored after applying single square pulses of 1V (1 Hz) as stimuli. The findings of this study showed that the pulse height of muscle contractions could not be affected by the exposure to electromagnetic fields. However, the latency period was effectively altered in RF-exposed samples. However, none of the experiments could show an alteration in the time interval between two subsequent contractions after exposure to electromagnetic fields. These findings support early reports which indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians including the effects on the pattern of muscle extractions.

Apparatus and method for the simultaneous detection of neutrons and ionizing electromagnetic radiation

DOEpatents

Bell, Zane W.

2000-01-01

A sensor for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising: a sensor for the detection of gamma radiation, the sensor defining a sensing head; the sensor further defining an output end in communication with the sensing head; and an exterior neutron-sensitive material configured to form around the sensing head; wherein the neutron-sensitive material, subsequent to the capture of the neutron, fissions into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the first excited state decaying via the emission of a single gamma ray at 478 keV which can in turn be detected by the sensing head; and wherein the sensing head can also detect the ionizing electromagnetic radiation from an incident radiation field without significant interference from the neutron-sensitive material. A method for simultaneously detecting neutrons and ionizing electromagnetic radiation comprising the steps of: providing a gamma ray sensitive detector comprising a sensing head and an output end; conforming an exterior neutron-sensitive material configured to form around the sensing head of the detector; capturing neutrons by the sensing head causing the neutron-sensitive material to fission into an alpha-particle and a .sup.7 Li ion that is in a first excited state in a majority of the fissions, the state decaying via the emission of a single gamma ray at 478 keV; sensing gamma rays entering the detector through the neutron-sensitive material; and producing an output through a readout device coupled to the output end; wherein the detector provides an output which is proportional to the energy of the absorbed ionizing electromagnetic radiation.

Low-gravity Orbiting Research Laboratory Environment Potential Impact on Space Biology Research

NASA Technical Reports Server (NTRS)

Jules, Kenol

2006-01-01

One of the major objectives of any orbital space research platform is to provide a quiescent low gravity, preferably a zero gravity environment, to perform fundamental as well as applied research. However, small disturbances exist onboard any low earth orbital research platform. The impact of these disturbances must be taken into account by space research scientists during their research planning, design and data analysis in order to avoid confounding factors in their science results. The reduced gravity environment of an orbiting research platform in low earth orbit is a complex phenomenon. Many factors, among others, such as experiment operations, equipment operation, life support systems and crew activity (if it is a crewed platform), aerodynamic drag, gravity gradient, rotational effects as well as the vehicle structural resonance frequencies (structural modes) contribute to form the overall reduced gravity environment in which space research is performed. The contribution of these small disturbances or accelerations is precisely why the environment is NOT a zero gravity environment, but a reduced acceleration environment. This paper does not discuss other factors such as radiation, electromagnetic interference, thermal and pressure gradient changes, acoustic and CO2 build-up to name a few that affect the space research environment as well, but it focuses solely on the magnitude of the acceleration level found on orbiting research laboratory used by research scientists to conduct space research. For ease of analysis this paper divides the frequency spectrum relevant to most of the space research disciplines into three regimes: a) quasi-steady, b) vibratory and c) transient. The International Space Station is used as an example to illustrate the point. The paper discusses the impact of these three regimes on space biology research and results from space flown experiments are used to illustrate the potential negative impact of these disturbances (accelerations) on space biology research.

Superposition of nonparaxial vectorial complex-source spherically focused beams: Axial Poynting singularity and reverse propagation

NASA Astrophysics Data System (ADS)

Mitri, F. G.

2016-08-01

In this work, counterintuitive effects such as the generation of an axial (i.e., long the direction of wave motion) zero-energy flux density (i.e., axial Poynting singularity) and reverse (i.e., negative) propagation of nonparaxial quasi-Gaussian electromagnetic (EM) beams are examined. Generalized analytical expressions for the EM field's components of a coherent superposition of two high-order quasi-Gaussian vortex beams of opposite handedness and different amplitudes are derived based on the complex-source-point method, stemming from Maxwell's vector equations and the Lorenz gauge condition. The general solutions exhibiting unusual effects satisfy the Helmholtz and Maxwell's equations. The EM beam components are characterized by nonzero integer degree and order (n ,m ) , respectively, an arbitrary waist w0, a diffraction convergence length known as the Rayleigh range zR, and a weighting (real) factor 0 ≤α ≤1 that describes the transition of the beam from a purely vortex (α =0 ) to a nonvortex (α =1 ) type. An attractive feature for this superposition is the description of strongly focused (or strongly divergent) wave fields. Computations of the EM power density as well as the linear and angular momentum density fluxes illustrate the analysis with particular emphasis on the polarization states of the vector potentials forming the beams and the weight of the coherent beam superposition causing the transition from the vortex to the nonvortex type. Should some conditions determined by the polarization state of the vector potentials and the beam parameters be met, an axial zero-energy flux density is predicted in addition to a negative retrograde propagation effect. Moreover, rotation reversal of the angular momentum flux density with respect to the beam handedness is anticipated, suggesting the possible generation of negative (left-handed) torques. The results are particularly useful in applications involving the design of strongly focused optical laser tweezers, tractor beams, optical spanners, arbitrary scattering, radiation force, angular momentum, and torque in particle manipulation, and other related topics.

The resolution of point sources of light as analyzed by quantum detection theory

NASA Technical Reports Server (NTRS)

Helstrom, C. W.

1972-01-01

The resolvability of point sources of incoherent light is analyzed by quantum detection theory in terms of two hypothesis-testing problems. In the first, the observer must decide whether there are two sources of equal radiant power at given locations, or whether there is only one source of twice the power located midway between them. In the second problem, either one, but not both, of two point sources is radiating, and the observer must decide which it is. The decisions are based on optimum processing of the electromagnetic field at the aperture of an optical instrument. In both problems the density operators of the field under the two hypotheses do not commute. The error probabilities, determined as functions of the separation of the points and the mean number of received photons, characterize the ultimate resolvability of the sources.

[The application of low-intensity electromagnetic radiation under immobilization stress conditions (an experimental study)].

PubMed

Korolev, Iu N; Bobrovnitskiĭ, I P; Nikoulina, L A; Mikhaĭlik, L V; Geniatulina, M S; Bobkova, A S

2014-01-01

The experiments carried out on outbred male white rats with the use of optical, electron-microscopic, biochemical, and radioimmunological methods have demonstrated that the application of low-intensity electromagnetic radiation (LI-EMR) with a flow density of 1 mcW/cm2 and a frequency of around 1,000 MHz both in the primary prophylaxis regime and as the therapeuticpreventive modality arrested the development of post-stress disorders in the rat testicles, liver, and thymus; moreover, it promoted activation of the adaptive, preventive, and compensatory processes. The data obtained provide a rationale for the application of low-intensity electromagnetic radiation to protect the organism from negative effects of stressful factors.

Electromagnetic field of a bunch intersecting a dielectric plate in a waveguide

NASA Astrophysics Data System (ADS)

Alekhina, Tatiana Yu; Tyukhtin, Andrey V.

2014-05-01

The electromagnetic field (EMF) of a bunch moving uniformly and traversing a dielectric plate located in a waveguide is investigated. The main attention is focused on the case when Cherenkov radiation is generated in the plate. Analysis of the field components of the mode is performed with methods of the complex variable function theory. An algorithm of computation using the exact expressions for the EMF is also presented. Consideration of the EMF structure for different time moments is given. It is shown that Cherenkov-transition radiation (CTR) is generated in the vacuum area after the plate under certain conditions. Results obtained might be of interest for development of new methods of generation of electromagnetic radiation.

Radiation enhanced efficiency of combined electromagnetic hyperthermia and chemotherapy of lung carcinoma using cisplatin functionalized magnetic nanoparticles.

PubMed

Babincová, M; Kontrisova, K; Durdík, S; Bergemann, C; Sourivong, P

2014-02-01

The effect of trimodality treatment consisting of hyperthermia, cisplatin and radiation was investigated in two non-small lung carcinoma cell lines with different sensitivities to cisplatin. Hyperthermia treatment was performed using heat released via Neél and Brown relaxation of magnetic nanoparticles in an alternating magnetic field. Radiation with dose 1.5 Gy was performed after 15 min electromagnetic hyperthermia and cisplatin treatment. Electromagnetic hyperthermia enhanced cisplatin-induced radiosensitization in both the cisplatin-sensitive H460 (viability 11.2 +/- 1.8 %) and cisplatin-resistant A549 (viability 14.5 +/- 2.3 %) lung carcinoma cell line. Proposed nanotechnology based trimodality cancer treatment may have therefore important clinical applications.

Magnetic Imaging: a New Tool for UK National Nuclear Security

NASA Astrophysics Data System (ADS)

Darrer, Brendan J.; Watson, Joe C.; Bartlett, Paul; Renzoni, Ferruccio

2015-01-01

Combating illicit trafficking of Special Nuclear Material may require the ability to image through electromagnetic shields. This is the case when the trafficking involves cargo containers. Thus, suitable detection techniques are required to penetrate a ferromagnetic enclosure. The present study considers techniques that employ an electromagnetic based principle of detection. It is generally assumed that a ferromagnetic metallic enclosure will effectively act as a Faraday cage to electromagnetic radiation and therefore screen any form of interrogating electromagnetic radiation from penetrating, thus denying the detection of any eventual hidden material. In contrast, we demonstrate that it is actually possible to capture magnetic images of a conductive object through a set of metallic ferromagnetic enclosures. This validates electromagnetic interrogation techniques as a potential detection tool for National Nuclear Security applications.

Magnetic Imaging: a New Tool for UK National Nuclear Security

PubMed Central

Darrer, Brendan J.; Watson, Joe C.; Bartlett, Paul; Renzoni, Ferruccio

2015-01-01

Combating illicit trafficking of Special Nuclear Material may require the ability to image through electromagnetic shields. This is the case when the trafficking involves cargo containers. Thus, suitable detection techniques are required to penetrate a ferromagnetic enclosure. The present study considers techniques that employ an electromagnetic based principle of detection. It is generally assumed that a ferromagnetic metallic enclosure will effectively act as a Faraday cage to electromagnetic radiation and therefore screen any form of interrogating electromagnetic radiation from penetrating, thus denying the detection of any eventual hidden material. In contrast, we demonstrate that it is actually possible to capture magnetic images of a conductive object through a set of metallic ferromagnetic enclosures. This validates electromagnetic interrogation techniques as a potential detection tool for National Nuclear Security applications. PMID:25608957

Magnetic imaging: a new tool for UK national nuclear security.

PubMed

Darrer, Brendan J; Watson, Joe C; Bartlett, Paul; Renzoni, Ferruccio

2015-01-22

Combating illicit trafficking of Special Nuclear Material may require the ability to image through electromagnetic shields. This is the case when the trafficking involves cargo containers. Thus, suitable detection techniques are required to penetrate a ferromagnetic enclosure. The present study considers techniques that employ an electromagnetic based principle of detection. It is generally assumed that a ferromagnetic metallic enclosure will effectively act as a Faraday cage to electromagnetic radiation and therefore screen any form of interrogating electromagnetic radiation from penetrating, thus denying the detection of any eventual hidden material. In contrast, we demonstrate that it is actually possible to capture magnetic images of a conductive object through a set of metallic ferromagnetic enclosures. This validates electromagnetic interrogation techniques as a potential detection tool for National Nuclear Security applications.

Effect of electromagnetic radiation on the coils used in aneurysm embolization.

PubMed

Lv, Xianli; Wu, Zhongxue; Li, Youxiang

2014-06-01

This study evaluated the effects of electromagnetic radiation in our daily lives on the coils used in aneurysm embolization. Faraday's electromagnetic induction principle was applied to analyze the effects of electromagnetic radiation on the coils used in aneurysm embolization. To induce a current of 0.5mA in less than 5 mm platinum coils required to stimulate peripheral nerves, the minimum magnetic field will be 0.86 μT. To induce a current of 0.5 mA in platinum coils by a hair dryer, the minimum aneurysm radius is 2.5 mm (5 mm aneurysm). To induce a current of 0.5 mA in platinum coils by a computer or TV, the minimum aneurysm radius is 8.6 mm (approximate 17 mm aneurysm). The minimum magnetic field is much larger than the flux densities produced by computer and TV, while the minimum aneurysm radius is much larger than most aneurysm sizes to levels produced by computer and TV. At present, the effects of electromagnetic radiation in our daily lives on intracranial coils do not produce a harmful reaction. Patients with coiled aneurysm are advised to avoid using hair dryers. This theory needs to be proved by further detailed complex investigations. Doctors should give patients additional instructions before the procedure, depending on this study.

Mobile phone electromagnetic radiation activates MAPK signaling and regulates viability in Drosophila.

PubMed

Lee, Kyu-Sun; Choi, Jong-Soon; Hong, Sae-Yong; Son, Tae-Ho; Yu, Kweon

2008-07-01

Mobile phones are widely used in the modern world. However, biological effects of electromagnetic radiation produced by mobile phones are largely unknown. In this report, we show biological effects of the mobile phone 835 MHz electromagnetic field (EMF) in the Drosophila model system. When flies were exposed to the specific absorption rate (SAR) 1.6 W/kg, which is the proposed exposure limit by the American National Standards Institute (ANSI), more than 90% of the flies were viable even after the 30 h exposure. However, in the SAR 4.0 W/kg strong EMF exposure, viability dropped from the 12 h exposure. These EMF exposures triggered stress response and increased the production of reactive oxygen species. The EMF exposures also activated extracellular signal regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) signaling, but not p38 kinase signaling. Interestingly, SAR 1.6 W/kg activated mainly ERK signaling and expression of an anti-apoptotic gene, whereas SAR 4.0 W/kg strongly activated JNK signaling and expression of apoptotic genes. In addition, SAR 4.0 W/kg amplified the number of apoptotic cells in the fly brain. These findings demonstrate that the exposure limit on electromagnetic radiation proposed by ANSI triggered ERK-survival signaling but the strong electromagnetic radiation activated JNK-apoptotic signaling in Drosophila.

Effect of Electromagnetic Radiation on the Coils Used in Aneurysm Embolization

PubMed Central

Lv, Xianli; Wu, Zhongxue; Li, Youxiang

2014-01-01

Summary This study evaluated the effects of electromagnetic radiation in our daily lives on the coils used in aneurysm embolization. Faraday’s electromagnetic induction principle was applied to analyze the effects of electromagnetic radiation on the coils used in aneurysm embolization. To induce a current of 0.5mA in less than 5 mm platinum coils required to stimulate peripheral nerves, the minimum magnetic field will be 0.86 μT. To induce a current of 0.5 mA in platinum coils by a hair dryer, the minimum aneurysm radius is 2.5 mm (5 mm aneurysm). To induce a current of 0.5 mA in platinum coils by a computer or TV, the minimum aneurysm radius is 8.6 mm (approximate 17 mm aneurysm). The minimum magnetic field is much larger than the flux densities produced by computer and TV, while the minimum aneurysm radius is much larger than most aneurysm sizes to levels produced by computer and TV. At present, the effects of electromagnetic radiation in our daily lives on intracranial coils do not produce a harmful reaction. Patients with coiled aneurysm are advised to avoid using hair dryers. This theory needs to be proved by further detailed complex investigations. Doctors should give patients additional instructions before the procedure, depending on this study. PMID:24976203

[The electroporation effects of high power pulse microwave and electromagnetic pulse irradiation on the membranes of cardiomyocyte cells and the mechanism therein involved].

PubMed

Deng, Hua; Wang, Dewen; Peng, Ruiyun; Wang, Shuiming; Chen, Jiankui; Zhang, Sa; Dong, Bo; Wang, Xiaomin

2005-08-01

Though there is ongoing public concern on potential hazards and risk of electromagnetic radiation, the bioeffects mechanism of electromagnetic fields remains obscure. Heart is one of the organs susceptive to electromagnetic fields (EMF). This study was designed to assess the influence of high power pulse microwave and electromagnetic pulse irradiation on cardiomyocytes, to explore the critical mechanism of electromagnetic fields, and to explain the regular course of injury caused by exposure to pulse EMF. Cultured cardiomyocytes were irradiated by high power pulse microwave and electromagnetic pulse first, then a series of apparatus including atom force microscope, laser scanning confocal microscope and flow cytometer were used to examine the changes of cell membrane conformation, structure and function. After irradiation, the cardiomyocytes pulsated slower or stop, the cells conformation was abnormal, the cells viability declined, and the percentage of apoptosis and necrosis increased significantly (P< 0.01). The cell membrane had pores unequal in size, and lost its penetration character. The concentration of Na+, K+, Ca2+, Cl-, Mg2+, Ca2+ and P3+ in cell culture medium increased significantly (P< 0.01). and the concentration of Ca2+ in cells ([Ca2+]i) decreased significantly (P<0.01). The results indicated that cardiomyocytes are susceptible to non-ionizing radiation. Pulse electromagnetic field can induce cardiomyocytes electroporation, and can do great damage to cells conformation, structure and function. Electroporation is one of the most critical mechanisms to explain the athermal effects of electromagnetic radiation.

Biological and Health Effects of Electromagnetic (Nonionizing) Radiation. LC Science Tracer Bullet.

ERIC Educational Resources Information Center

Halasz, Hisako, Comp.

The environment we live in today is filled with human-created electromagnetic fields generated by a variety of sources, including radio and television transmitters, power lines, and visual display terminals. (In addition, there exists a natural background of electromagnetic fields.) The term "electromagnetic pollution" is often used to…

Influence of the distribution of PWO crystal radiation hardness on electromagnetic calorimeter performance

NASA Astrophysics Data System (ADS)

Drobychev, Gleb Yu.; Borisevich, Andrei E.; Korjik, Mikhail V.; Lecoq, Paul; Moroz, Valeri I.; Peigneux, Jean-Pierre

2002-06-01

The distribution of about 5000 mass-produced PWO crystals by their light yield and radiation hardness is analysed. The correlation between results of radiation hardness measurements at low and saturating dose rates is refined. A method for the evaluation of the energy resolution of the electromagnetic calorimeter accounting for a distribution of individual PWO crystal characteristics is proposed. A preliminary analysis of the PWO crystal recovery kinetics is also performed.

Scattering of point particles by black holes: Gravitational radiation

NASA Astrophysics Data System (ADS)

Hopper, Seth; Cardoso, Vitor

2018-02-01

Gravitational waves can teach us not only about sources and the environment where they were generated, but also about the gravitational interaction itself. Here we study the features of gravitational radiation produced during the scattering of a pointlike mass by a black hole. Our results are exact (to numerical error) at any order in a velocity expansion, and are compared against various approximations. At large impact parameter and relatively small velocities our results agree to within percent level with various post-Newtonian and weak-field results. Further, we find good agreement with scaling predictions in the weak-field/high-energy regime. Lastly, we achieve striking agreement with zero-frequency estimates.

Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors

PubMed Central

Mortazavi, SMJ; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, AR

2014-01-01

Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors. PMID:25505778

Electromagnetic Radiofrequency Radiation Emitted from GSM Mobile Phones Decreases the Accuracy of Home Blood Glucose Monitors.

PubMed

Mortazavi, Smj; Gholampour, M; Haghani, M; Mortazavi, G; Mortazavi, Ar

2014-09-01

Mobile phones are two-way radios that emit electromagnetic radiation in microwave range. As the number of mobile phone users has reached 6 billion, the bioeffects of exposure to mobile phone radiation and mobile phone electromagnetic interference with electronic equipment have received more attention, globally. As self-monitoring of blood glucose can be a beneficial part of diabetes control, home blood glucose testing kits are very popular. The main goal of this study was to investigate if radiofrequency radiation emitted from a common GSM mobile phone can alter the accuracy of home blood glucose monitors. Forty five female nondiabetic students aged 17-20 years old participated in this study. For Control-EMF group (30 students), blood glucose concentration for each individual was measured in presence and absence of radiofrequency radiation emitted by a common GSM mobile phone (HTC touch, Diamond 2) while the phone was ringing. For Control- Repeat group (15 students), two repeated measurements were performed for each participant in the absence of electromagnetic fields. The magnitude of the changes between glucose levels in two repeated measurements (|ΔC|) in Control-Repeat group was 1.07 ± 0.88 mg/dl while this magnitude for Control-EMF group was 7.53 ± 4.76 mg/dl (P < 0.001, two-tailed test). To the best of our knowledge, this is the first study to assess the electromagnetic interference in home blood glucose monitors. It can be concluded that electromagnetic interference from mobile phones has an adverse effect on the accuracy of home blood glucose monitors. We suggest that mobile phones should be used at least 50 cm away from home blood glucose monitors.

Optical system for high resolution spectrometer/monochromator

DOEpatents

Hettrick, Michael C.; Underwood, James H.

1988-01-01

An optical system for use in a spectrometer or monochromator employing a mirror which reflects electromagnetic radiation from a source to converge with same in a plane. A straight grooved, varied-spaced diffraction grating receives the converging electromagnetic radiation from the mirror and produces a spectral image for capture by a detector, target or like receiver.

Electro-Optic Generation and Detection of Femtosecond Electromagnetic Pulses

DTIC Science & Technology

1991-11-20

electromagnetic pulses from an electro - optic crystal following their generation by electro - optic Cherenkov radiation, and their subsequent propagation and detection...in free space; (4) The measurement of subpicosecond electrical response of a new organic electrooptic material (polymer); (5) The observation of terahertz transition radiation from the surfaces of electro - optic crystals.

Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

ERIC Educational Resources Information Center

Sage, Cindy; Burgio, Ernesto

2018-01-01

Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

[Low-energy wideband electromagnetic radiation and manual therapy in the treatment of neurological manifestations of spinal osteochondrosis].

PubMed

Afoshin, S A; Gerasimenko, M Iu

2006-01-01

It is shown that the advanced technique of low-energy wideband electromagnetic radiation improves vascular tonicity and peripheral circulation while a modified technique of manual therapy facilitates movements in the affected part of the spine and reduces tonicity of the muscles involved in the pathological process.

EFFECTS OF LASER RADIATION ON MATTER. LASER PLASMA: Radiation emitted by a beam of particles crossing an inhomogeneous electromagnetic wave

NASA Astrophysics Data System (ADS)

Kol'tsov, A. V.; Serov, Alexander V.

1995-03-01

A theoretical investigation is made of the time dependence of the spatial distribution of particles injected perpendicular to the direction of propagation of a linearly polarised inhomogeneous electromagnetic wave and reflected by this wave. It is shown that such reflection modulates the particle density in a beam which is homogeneous at injection. Stimulated emission of radiation from a ribbon electron beam reflected by a wave is considered. The spectral—angular and polarisation characteristics of such radiation are investigated.

Next generation distal locking for intramedullary nails using an electromagnetic X-ray-radiation-free real-time navigation system.

PubMed

Hoffmann, Michael; Schröder, Malte; Lehmann, Wolfgang; Kammal, Michael; Rueger, Johannes Maria; Herrman Ruecker, Andreas

2012-07-01

Distal locking marks one challenging step during intramedullary nailing that can lead to an increased irradiation and prolonged operation times. The aim of this study was to evaluate the reliability and efficacy of an X-ray-radiation-free real-time navigation system for distal locking procedures. A prospective randomized cadaver study with 50 standard free-hand fluoroscopic-guided and 50 electromagnetic-guided distal locking procedures was performed. All procedures were timed using a stopwatch. Intraoperative fluoroscopy exposure time and absorbed radiation dose (mGy) readings were documented. All tibial nails were locked with two mediolateral and one anteroposterior screw. Successful distal locking was accomplished once correct placement of all three screws was confirmed. Successful distal locking was achieved in 98 cases. No complications were encountered using the electromagnetic navigation system. Eight complications arose during free-hand fluoroscopic distal locking. Undetected secondary drill slippage on the ipsilateral cortex accounted for most problems followed by undetected intradrilling misdirection causing a fissural fracture of the contralateral cortex while screw insertion in one case. Compared with the free-hand fluoroscopic technique, electromagnetically navigated distal locking provides a median time benefit of 244 seconds without using ionizing radiation. Compared with the standard free-hand fluoroscopic technique, the electromagnetic guidance system used in this study showed high reliability and was associated with less complications, took significantly less time, and used no radiation exposure for distal locking procedures. Therapeutic study, level II.

[The ultrastructure of Sertoli cells and spermatogonia in the rats exposed to radiation under conditions of therapeutic and prophylactic application of low-intensity electromagnetic emission].

PubMed

Korolev, Y N; Bobrovnitskii, I P; Geniatulina, M S; Nikulina, L A; Mikhailik, L V

2018-04-09

it has been demonstrated in various experimental studies that radiation exposure produces a negative impact on the processes of spermatogenesis associated with the disturbances of the microcirculation processes in the testes and the development of cellular and intracellular disintegration expressed as destructive changes in the cells leading to their death. The objective of the present study was to detect the ultrastructural abnormalities in the cells of Sertoli and spermatogonia under conditions of their exposure to radiation and to identify the peculiarities of their regeneration under the influence of the therapeutic and prophylactic application of low-intensity ultra-high frequency (UHF) electromagnetic radiation (EMR) and low-intensity low-frequency magnetic field (MF). The experiments were carried out on 28 non-pedigree mature male rats with the body weight 180-220 g that were divided into four groups. The first study group was comprised of the animals exposed to radiation followed by the application of low-intensity ultra-high frequency UHF electromagnetic radiation EMR. The rats in the second study group experienced effects of radiation and low-intensity low-frequency MF. The animals of the third (control) group were exposed to radiation alone, and those comprising the fourth group 1 (only radiation exposure) were considered to be intact. The studies with the use of electron microscopy showed that the therapeutic and prophylactic application of low-intensity ultra-high frequency (UHF) electromagnetic radiation and low-intensity low-frequency magnetic field caused the decrease in the number and the severity of post-radiation defects in the treated cells together with the increase of the number and size of mitochondria as well as hyperplasia of ribosomes; moreover, it promoted cellular and intracellular regeneration. UHF electromagnetic radiation had a more pronounced stimulating effect on the regeneration processes as compared with low-frequency MF. Particularly active processes of intracellular regeneration evolved in Sertoli cells; they were manifested as the increase in the number and size of mitochondria, enhanced hyperplasia of ribosomes, and formation of polysomes and new membranes of the granular endoplasmic reticulum. In spermatogonia, intracellular regeneration was less pronounced than in the Sertoli cells but was accompanied by enhanced cell regeneration and a greater number of reserve stem/progenitor cells. The results of the present study provide a rationale for the possibility of the application of a low-frequency magnetic field and especially UHF electromagnetic radiation for the further development of the promising therapeutic and preventive technologies with a view to their introduction into routine clinical practice dealing with radiation-induced pathology.

Transverse electromagnetic horn antenna with resistively-loaded exterior surfaces

DOEpatents

Aurand, John F.

1999-01-01

An improved transverse electromagnetic (TEM) horn antenna comprises a resistive loading material on the exterior surfaces of the antenna plates. The resistive loading material attenuates or inhibits currents on the exterior surfaces of the TEM horn antenna. The exterior electromagnetic fields are of opposite polarity in comparison to the primary and desired interior electromagnetic field, thus inherently cause partial cancellation of the interior wave upon radiation or upon reception. Reducing the exterior fields increases the radiation efficiency of the antenna by reducing the cancellation of the primary interior field (supported by the interior surface currents). This increases the transmit gain and receive sensitivity of the TEM horn antenna, as well as improving the transient (time-domain) response.

Design of tapered arm impulse radiating antenna with log periodic lens system for skin cancer treatment.

PubMed

Petrishia, A; Sasikala, M

2014-04-01

A Prolate-Spheroidal Impulse Radiating Antenna (PSIRA) is used as a non-invasive technique for generating an electromagnetic implosion to kill melanoma cells. It can launch and focus fast (100 ps) high voltage (>50 KV) pulses into the biological targets. It can be used to obtain electromagnetic focusing on the target to reduce the damage to the tissue layers surrounding the target (skin). The main aim of this work is to improve the gain of the antenna, enhance the electric field intensity and to reduce the spot size at the focal point. In this work the PSIRA with tapered arm is designed to increase the gain of the antenna. The log periodic lens system is designed to enhance the electric field and reduce the spot size. The IRA with tapered arms located at the position of φ = 60° gives a gain improvement of 14.28% when compared to a traditional IRA. In this work a 10-layer dielectric lens system is designed to match the 100 ps pulses to the skin phantom. Simulation results show that the electric field is increased by a factor of 2. The spot size is reduced from 1 cm to 0.75 cm at the focal point where the target is placed. The proposed Log periodic lens system provides an increase in electric field amplitude and reduction in spot size.

[Patient exposure to electromagnetic fields in magnetic resonance scanners: a review].

PubMed

Guibelalde del Castillo, E

2013-12-01

The use of non-ionizing electromagnetic fields in the low frequency end of the electromagnetic spectrum and static fields, radiofrequencies (RF), and microwaves is fundamental both in modern communication systems and in diagnostic medical imaging techniques like magnetic resonance imaging (MRI). The proliferation of these applications in recent decades has led to intense activity in developing regulations to guarantee their safety and to the establishment of guidelines and legal recommendations for the public, workers, and patients. In April 2012 it was foreseen that the European Parliament and Council would approve and publish a directive on the minimum health and safety requirements regarding the exposure of workers to the risks arising from electromagnetic fields, which would modify Directive 2004/40/EC. New studies related to the exposure to electromagnetic radiation and its impact on health published in recent years have led to a new postponement, and it is now foreseen that the directive will come into effect in October 2013. One of the most noteworthy aspects of the new version of the directive is the exclusion of the limits of occupational exposure to electromagnetic fields in the clinical use of MRI. In exchange for this exception, physicians and experts in protection against non-ionizing radiation are asked to make additional efforts to train workers exposed to non-ionizing radiation and to establish mechanisms to guarantee the correct application of non-ionizing electromagnetic fields in patients, along similar lines to the principles of justification and optimization established for ionizing radiation. On the basis of the most recently published studies, this article reviews some safety-related aspects to take into account when examining patients with MRI with high magnetic fields. Copyright © 2013 SERAM. Published by Elsevier Espana. All rights reserved.

47 CFR 22.99 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... converts radio frequency electrical energy to radiated electromagnetic energy and vice versa; in a... portion of the electromagnetic spectrum within which the emission power of the authorized transmitter(s.... The portion of the electromagnetic spectrum assigned by the FCC for one emission. In certain...

47 CFR 22.99 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... converts radio frequency electrical energy to radiated electromagnetic energy and vice versa; in a... portion of the electromagnetic spectrum within which the emission power of the authorized transmitter(s.... The portion of the electromagnetic spectrum assigned by the FCC for one emission. In certain...

47 CFR 22.99 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

... converts radio frequency electrical energy to radiated electromagnetic energy and vice versa; in a... portion of the electromagnetic spectrum within which the emission power of the authorized transmitter(s.... The portion of the electromagnetic spectrum assigned by the FCC for one emission. In certain...

47 CFR 22.99 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

... converts radio frequency electrical energy to radiated electromagnetic energy and vice versa; in a... portion of the electromagnetic spectrum within which the emission power of the authorized transmitter(s.... The portion of the electromagnetic spectrum assigned by the FCC for one emission. In certain...

47 CFR 22.99 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... converts radio frequency electrical energy to radiated electromagnetic energy and vice versa; in a... portion of the electromagnetic spectrum within which the emission power of the authorized transmitter(s.... The portion of the electromagnetic spectrum assigned by the FCC for one emission. In certain...

Electromagnetic coupling to centimeter-scale mechanical membrane resonators via RF cylindrical cavities

NASA Astrophysics Data System (ADS)

Martinez, Luis A.; Castelli, Alessandro R.; Delmas, William; Sharping, Jay E.; Chiao, Raymond

2016-11-01

We present experimental and theoretical results for the excitation of a mechanical oscillator via radiation pressure with a room-temperature system employing a relatively low-(Q) centimeter-size mechanical oscillator coupled to a relatively low-Q standard three-dimensional radio-frequency (RF) cavity resonator. We describe the forces giving rise to optomechanical coupling using the Maxwell stress tensor and show that nanometer-scale displacements are possible and experimentally observable. The experimental system is composed of a 35 mm diameter silicon nitride membrane sputtered with a 300 nm gold conducting film and attached to the end of a RF copper cylindrical cavity. The RF cavity is operated in its {{TE}}011 mode and amplitude modulated on resonance with the fundamental drum modes of the membrane. Membrane motion is monitored using an unbalanced, non-zero optical path difference, optically filtered Michelson interferometer capable of measuring sub-nanometer displacements.

Effect of a magnetic field on Schwinger mechanism in de Sitter spacetime

NASA Astrophysics Data System (ADS)

Bavarsad, Ehsan; Kim, Sang Pyo; Stahl, Clément; Xue, She-Sheng

2018-01-01

We investigate the effect of a uniform magnetic field background on scalar QED pair production in a four-dimensional de Sitter spacetime (dS4 ). We obtain a pair production rate which agrees with the known Schwinger result in the limit of Minkowski spacetime and with Hawking radiation in dS spacetime in the zero electric field limit. Our results describe how the cosmic magnetic field affects the pair production rate in cosmological setups. In addition, using the zeta function regularization scheme we calculate the induced current and examine the effect of a magnetic field on the vacuum expectation value of the current operator. We find that, in the case of a strong electromagnetic background the current responds as E .B , while in the infrared regime, it responds as B /E , which leads to a phenomenon of infrared hyperconductivity. These results for the induced current have important applications for the cosmic magnetic field evolution.

Gas chromatography/matrix-isolation apparatus

DOEpatents

Reedy, G.T.

1986-06-10

A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one reflecting surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the reflecting surface which is maintained at a sufficiently low temperature to cause solidification. A first parabolic mirror directs an incident beam of electromagnetic radiation, such as in the infrared (IR) spectrum, from a source onto the sample/matrix mixture while a second parabolic mirror directs a second beam of electromagnetic radiation reflected by the specular surface to an IR spectrometer for determining the absorption spectra of the sample material deposited on the reflecting surface. The pair of off-axis parabolic mirrors having a common focal point are positioned outside of the vacuum chamber and may be displaced in combination for improved beam positioning and alignment. The carousel is provided with an aperture for each reflecting surface to facilitate accurate positioning of the incident beam relative to the gas-samples under analysis. Improved gas-sample deposition is insured by the use of a long focal length stereomicroscope positioned outside of the vacuum chamber for monitoring sample formation through a window, while the sample collector is positioned outside of the zone bounded by the incident and reflected electromagnetic beams for improved sample access and monitoring. 10 figs.

Gas chromatography/matrix-isolation apparatus

DOEpatents

Reedy, Gerald T.

1986-01-01

A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one reflecting surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the reflecting surface which is maintained at a sufficiently low temperature to cause solidification. A first parabolic mirror directs an incident beam of electromagnetic radiation, such as in the infrared (IR) spectrum, from a source onto the sample/matrix mixture while a second parabolic mirror directs a second beam of electromagnetic radiation reflected by the specular surface to an IR spectrometer for determining the absorption spectra of the sample material deposited on the reflecting surface. The pair of off-axis parabolic mirrors having a common focal point are positioned outside of the vacuum chamber and may be displaced in combination for improved beam positioning and alignment. The carousel is provided with an aperture for each reflecting surface to facilitate accurate positioning of the incident beam relative to the gas-samples under analysis. Improved gas-sample deposition is insured by the use of a long focal length stereomicroscope positioned outside of the vacuum chamber for monitoring sample formation through a window, while the sample collector is positioned outside of the zone bounded by the incident and reflected electromagnetic beams for improved sample access and monitoring.

Food collection and response to pheromones in an ant species exposed to electromagnetic radiation.

PubMed

Cammaerts, Marie-Claire; Rachidi, Zoheir; Bellens, François; De Doncker, Philippe

2013-09-01

We used the ant species Myrmica sabuleti as a model to study the impact of electromagnetic waves on social insects' response to their pheromones and their food collection. We quantified M. sabuleti workers' response to their trail, area marking and alarm pheromone under normal conditions. Then, we quantified the same responses while under the influence of electromagnetic waves. Under such an influence, ants followed trails for only short distances, no longer arrived at marked areas and no longer orientated themselves to a source of alarm pheromone. Also when exposed to electromagnetic waves, ants became unable to return to their nest and recruit congeners; therefore, the number of ants collecting food increases only slightly and slowly. After 180 h of exposure, their colonies deteriorated. Electromagnetic radiation obviously affects social insects' behavior and physiology.

[Nonionizing radiation and electromagnetic fields].

PubMed

Bernhardt, J H

1991-01-01

Nonionising radiation comprises all kinds of radiation and fields of the electromagnetic spectrum where biological matter is not ionised, as well as mechanical waves such as infrasound and ultrasound. The electromagnetic spectrum is subdivided into individual sections and includes: Static and low-frequency electric and magnetic fields including technical applications of energy with mains frequency, radio frequency fields, microwaves and optic radiation (infrared, visible light, ultraviolet radiation including laser). The following categories of persons can be affected by emissions by non-ionising radiation: Persons in the environment and in the household, workers, patients undergoing medical diagnosis or treatment. If the radiation is sufficiently intense, or if the fields are of appropriate strength, a multitude of effects can occur (depending on the type of radiation), such as heat and stimulating or irritating action, inflammations of the skin or eyes, changes in the blood picture, burns or in some cases cancer as a late sequel. The ability of radiation to penetrate into the human body, as well as the types of interaction with biological tissue, with organs and organisms, differs significantly for the various kinds of nonionising radiation. The following aspects of nonionising radiation are discussed: protection of humans against excessive sunlight rays when sunbathing and when exposed to UV radiation (e.g. in solaria); health risks of radio and microwaves (safety of microwave cookers and mobile radio units); effects on human health by electric and magnetic fields in everyday life.

Strain-induced three-photon effects

NASA Astrophysics Data System (ADS)

Jeong, Jae-Woo; Shin, Sung-Chul; Lyubchanskii, I. L.; Varyukhin, V. N.

2000-11-01

Strain-induced three-photon effects such as optical second-harmonic generation and hyper-Rayleigh light scattering, characterized by electromagnetic radiation at the double frequency of an incident light, are phenomenologically investigated by adopting a nonlinear photoelastic interaction. The relations between the strain and the nonlinear optical susceptibility for crystal surfaces with point symmetries of 4mm and 3m are described by a symmetry analysis of the nonlinear photoelastic tensor. We theoretically demonstrate a possibility of determining the strain components by measuring the rotational anisotropy of radiation at the second-harmonic frequency. Hyper-Rayleigh light scattering by dislocation strain is also described using a nonlinear photoelastic tensor. The angular dependencies of light scattered at the double frequency of an incident light for different scattering geometries are analyzed.

Experiments and Demonstrations in Physics: Bar-Ilan Physics Laboratory (2nd Edition)

NASA Astrophysics Data System (ADS)

Kraftmakher, Yaakov

2014-08-01

The following sections are included: * Data-acquisition systems from PASCO * ScienceWorkshop 750 Interface and DataStudio software * 850 Universal Interface and Capstone software * Mass on spring * Torsional pendulum * Hooke's law * Characteristics of DC source * Digital storage oscilloscope * Charging and discharging a capacitor * Charge and energy stored in a capacitor * Speed of sound in air * Lissajous patterns * I-V characteristics * Light bulb * Short time intervals * Temperature measurements * Oersted's great discovery * Magnetic field measurements * Magnetic force * Magnetic braking * Curie's point I * Electric power in AC circuits * Faraday's law of induction I * Self-inductance and mutual inductance * Electromagnetic screening * LCR circuit I * Coupled LCR circuits * Probability functions * Photometric laws * Kirchhoff's rule for thermal radiation * Malus' law * Infrared radiation * Irradiance and illuminance

Analysis of the Radiated Field in an Electromagnetic Reverberation Chamber as an Upset-Inducing Stimulus for Digital Systems

NASA Technical Reports Server (NTRS)

Torres-Pomales, Wilfredo

2012-01-01

Preliminary data analysis for a physical fault injection experiment of a digital system exposed to High Intensity Radiated Fields (HIRF) in an electromagnetic reverberation chamber suggests a direct causal relation between the time profile of the field strength amplitude in the chamber and the severity of observed effects at the outputs of the radiated system. This report presents an analysis of the field strength modulation induced by the movement of the field stirrers in the reverberation chamber. The analysis is framed as a characterization of the discrete features of the field strength waveform responsible for the faults experienced by a radiated digital system. The results presented here will serve as a basis to refine the approach for a detailed analysis of HIRF-induced upsets observed during the radiation experiment. This work offers a novel perspective into the use of an electromagnetic reverberation chamber to generate upset-inducing stimuli for the study of fault effects in digital systems.

Optical system for high resolution spectrometer/monochromator

DOEpatents

Hettrick, M.C.; Underwood, J.H.

1988-10-11

An optical system for use in a spectrometer or monochromator employing a mirror which reflects electromagnetic radiation from a source to converge with same in a plane is disclosed. A straight grooved, varied-spaced diffraction grating receives the converging electromagnetic radiation from the mirror and produces a spectral image for capture by a detector, target or like receiver. 11 figs.

[Interaction of oxytocin, laser and electromagnetic radiation on the persistence properties of Staphylococcus aureus].

PubMed

Kurlaev, P P; Chernova, O L; Kirgizova, S B

2000-01-01

The suppressive action of oxytocin, heliumneon radiation and ultrahigh-frequency electromagnetic waves (UHF-therapy) on the persistence properties of S. aureus has been experimentally established. The effectiveness of the therapeutic actions under study in the treatment of patients with the prognosticated unfavorable course of purulent inflammatory diseases of soft tissues has been shown.

Effect of 935-MHz phone-simulating electromagnetic radiation on endometrial glandular cells during mouse embryo implantation.

PubMed

Liu, Wenhui; Zheng, Xinmin; Qu, Zaiqing; Zhang, Ming; Zhou, Chun; Ma, Ling; Zhang, Yuanzhen

2012-10-01

This study examined the impact of 935MHz phone-simulating electromagnetic radiation on embryo implantation of pregnant mice. Each 7-week-old Kunming (KM) female white mouse was set up with a KM male mouse in a single cage for mating overnight after induction of ovulation. In the first three days of pregnancy, the pregnant mice was exposed to electromagnetic radiation at low-intensity (150 μW/cm(2), ranging from 130 to 200 μW/cm(2), for 2- or 4-h exposure every day), mid-intensity (570 μW/cm(2), ranging from 400 to 700 μW/cm(2), for 2- or 4-h exposure every day) or high-intensity (1400 μW/cm(2), ranging from 1200 to 1500 μW/cm(2), for 2- or 4-h exposure every day), respectively. On the day 4 after gestation (known as the window of murine embryo implantation), the endometrium was collected and the suspension of endometrial glandular cells was made. Laser scanning microscopy was employed to detect the mitochondrial membrane potential and intracellular calcium ion concentration. In high-intensity, 2- and 4-h groups, mitochondrial membrane potential of endometrial glandular cells was significantly lower than that in the normal control group (P<0.05). The calcium ion concentration was increased in low-intensity 2-h group but decreased in high-intensity 4-h group as compared with the normal control group (P<0.05). However, no significant difference was found in mitochondrial membrane potential of endometrial glandular cells between low- or mid-intensity groups and the normal control group, indicating stronger intensity of the electromagnetic radiation and longer length of the radiation are required to inflict a remarkable functional and structural damage to mitochondrial membrane. Our data demonstrated that electromagnetic radiation with a 935-MHz phone for 4 h conspicuously decreased mitochondrial membrane potential and lowered the calcium ion concentration of endometrial glandular cells. It is suggested that high-intensity electromagnetic radiation is very likely to induce the death of embryonic cells and decrease the chance of their implantation, thereby posing a high risk to pregnancy.

Classical electromagnetic radiation of the Dirac electron

NASA Technical Reports Server (NTRS)

Lanyi, G.

1973-01-01

A wave-function-dependent four-vector potential is added to the Dirac equation in order to achieve conservation of energy and momentum for a Dirac electron and its emitted electromagnetic field. The resultant equation contains solutions which describe transitions between different energy states of the electron. As a consequence it is possible to follow the space-time evolution of such a process. This evolution is shown in the case of the spontaneous emission of an electromagnetic field by an electron bound in a hydrogen-like atom. The intensity of the radiation and the spectral distribution are calculated for transitions between two eigenstates. The theory gives a self-consistent deterministic description of some simple radiation processes without using quantum electrodynamics or the correspondence principle.

No detectable bioeffects following acute exposure to high peak power ultra-wide band electromagnetic radiation in rats.

PubMed

Walters, T J; Mason, P A; Sherry, C J; Steffen, C; Merritt, J H

1995-06-01

A wide range assessment of the possible bioeffects of an acute exposure to high peak power ultra-wide band (UWB) electromagnetic radiation was performed in rats. The UWB-exposure consisted of 2 min of pulsed (frequency: 60 Hz, pulse width: 5-10 ns) UWB (bandwidth: 0.25-2.50 GHz) electromagnetic radiation. Rats were examined using one of the following: 1) a functional observational battery (FOB); 2) a swimming performance test; 3) a complete panel of blood chemistries; or 4) determination of the expression of the c-fos protein in immunohistologically-stained sections of the brain. No significant differences were found between UWB- or sham-exposed rats on any of the measured parameters.

Impact of electromagnetic radiation emitted by monitors on changes in the cellular membrane structure and protective antioxidant effect of vitamin A - In vitro study.

PubMed

Lewicka, Małgorzata; Henrykowska, Gabriela; Zawadzka, Magdalena; Rutkowski, Maciej; Pacholski, Krzysztof; Buczyński, Andrzej

2017-07-14

The increasing number of devices emitting electromagnetic radiation (EMR) in people's everyday life attracted the attention of researchers because of possible adverse effects of this factor on living organisms. One of the EMR effect may be peroxidation of lipid membranes formed as a result of free radical process. The article presents the results of in vitro studies aimed at identifying changes in malondialdehyde (MDA) concentration - a marker of lipid peroxidation and antioxidant role of vitamin A during the exposure of blood platelets to electromagnetic radiation generated by liquid-crystal-display (LCD) monitors. Electromagnetic radiation emitted by LCD monitors is characterized by parameters: 1 kHz frequency and 220 V/m intensity (15 cm from display screen). The time of exposure was 30 and 60 min. The study was conducted on porcine blood platelets. The samples were divided into 6 groups: unexposed to radiation, unexposed + vitamin A, exposed for 30 min, exposed for 30 min + vitamin A, exposed for 60 min, exposed for 60 min + vitamin A. The MDA concentration in blood platelets increases significantly as compared to control values after 60 min of exposure to EMR. A significant decrease in MDA concentration after the addition of vitamin A was noticed. In the blood samples exposed to EMR for 30 and 60 min the MDA concentration was significantly increased by addition of vitamin A. The results show the possibly negative effect of electromagnetic radiation on the cellular membrane structure manifested by changes in malondialdehyde concentration and indicate a possible protective role of vitamin A in this process. Int J Occup Med Environ Health 2017;30(5):695-703. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

Spin zero Hawking radiation for non-zero-angular momentum mode

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

Ngampitipan, Tritos; Bonserm, Petarpa; Visser, Matt

2015-05-15

Black hole greybody factors carry some quantum black hole information. Studying greybody factors may lead to understanding the quantum nature of black holes. However, solving for exact greybody factors in many black hole systems is impossible. One way to deal with this problem is to place some rigorous analytic bounds on the greybody factors. In this paper, we calculate rigorous bounds on the greybody factors for spin zero hawking radiation for non-zero-angular momentum mode from the Kerr-Newman black holes.

A biotechnological project with a gamma radiation source of 100,000 Ci

NASA Astrophysics Data System (ADS)

Lombardo, J. H.; Smolko, E. E.

A project for the production of radiovaccines and other bio-medical products is presented which includes a radiation facility provided with a gamma ray source equivalent to 100,000 Ci of Co-60. The whole process incorporates novel basic features in virus production and inactivation steps. The former is carried out in animals previously subjected to immunodepression through electromagnetic radiation. The later is obtained at low temperatures by using either electromagnetic or particle radiations. A vaccine manufacture process is shown to illustrate the utilization of ionizing radiations to obtain a foot and mouth disease virus (FMDV) vaccine with good antigenic quality and low cost.

Acoustic manipulation of active spherical carriers: Generation of negative radiation force

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

Rajabi, Majid, E-mail: majid_rajabi@iust.ac.ir; Mojahed, Alireza

2016-09-15

This paper examines theoretically a novel mechanism of generating negative (pulling) radiation force for acoustic manipulation of spherical carriers equipped with piezoelectric actuators in its inner surface. In this mechanism, the spherical particle is handled by common plane progressive monochromatic acoustic waves instead of zero-/higher- order Bessel beams or standing waves field. The handling strategy is based on applying a spatially uniform harmonic electrical voltage at the piezoelectric actuator with the same frequency of handling acoustic waves, in order to change the radiation force effect from repulsive (away from source) to attractive (toward source). This study may be considered asmore » a start point for development of contact-free precise handling and entrapment technology of active carriers which are essential in many engineering and medicine applications.« less

Modeling of ultrasonic and terahertz radiations in defective tiles for condition monitoring of thermal protection systems

NASA Astrophysics Data System (ADS)

Kabiri Rahani, Ehsan

Condition based monitoring of Thermal Protection Systems (TPS) is necessary for safe operations of space shuttles when quick turn-around time is desired. In the current research Terahertz radiation (T-ray) has been used to detect mechanical and heat induced damages in TPS tiles. Voids and cracks inside the foam tile are denoted as mechanical damage while property changes due to long and short term exposures of tiles to high heat are denoted as heat induced damage. Ultrasonic waves cannot detect cracks and voids inside the tile because the tile material (silica foam) has high attenuation for ultrasonic energy. Instead, electromagnetic terahertz radiation can easily penetrate into the foam material and detect the internal voids although this electromagnetic radiation finds it difficult to detect delaminations between the foam tile and the substrate plate. Thus these two technologies are complementary to each other for TPS inspection. Ultrasonic and T-ray field modeling in free and mounted tiles with different types of mechanical and thermal damages has been the focus of this research. Shortcomings and limitations of FEM method in modeling 3D problems especially at high-frequencies has been discussed and a newly developed semi-analytical technique called Distributed Point Source Method (DPSM) has been used for this purpose. A FORTRAN code called DPSM3D has been developed to model both ultrasonic and electromagnetic problems using the conventional DPSM method. This code is designed in a general form capable of modeling a variety of geometries. DPSM has been extended from ultrasonic applications to electromagnetic to model THz Gaussian beams, multilayered dielectrics and Gaussian beam-scatterer interaction problems. Since the conventional DPSM has some drawbacks, to overcome it two modification methods called G-DPSM and ESM have been proposed. The conventional DPSM in the past was only capable of solving time harmonic (frequency domain) problems. Time history was obtained by FFT (Fast Fourier Transform) algorithm. In this research DPSM has been extended to model DPSM transient problems without using FFT. This modified technique has been denoted as t-DPSM. Using DPSM, scattering of focused ultrasonic fields by single and multiple cavities in fluid & solid media is studied. It is investigated when two cavities in close proximity can be distinguished and when it is not possible. A comparison between the radiation forces generated by the ultrasonic energies reflected from two small cavities versus a single big cavity is also carried out.

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.

The steady state solutions of radiatively driven stellar winds for a non-Sobolev, pure absorption model

NASA Technical Reports Server (NTRS)

Poe, C. H.; Owocki, S. P.; Castor, J. I.

1990-01-01

The steady state solution topology for absorption line-driven flows is investigated for the condition that the Sobolev approximation is not used to compute the line force. The solution topology near the sonic point is of the nodal type with two positive slope solutions. The shallower of these slopes applies to reasonable lower boundary conditions and realistic ion thermal speed v(th) and to the Sobolev limit of zero of the usual Castor, Abbott, and Klein model. At finite v(th), this solution consists of a family of very similar solutions converging on the sonic point. It is concluded that a non-Sobolev, absorption line-driven flow with a realistic values of v(th) has no uniquely defined steady state. To the extent that a pure absorption model of the outflow of stellar winds is applicable, radiatively driven winds should be intrinsically variable.

Statistical analysis of electromagnetic radiation measurements in the vicinity of GSM/UMTS base station antenna masts.

PubMed

Koprivica, Mladen; Neskovic, Natasa; Neskovic, Aleksandar; Paunovic, George

2014-01-01

As a result of dense installations of public mobile base station, additional electromagnetic radiation occurs in the living environment. In order to determine the level of radio-frequency radiation generated by base stations, extensive electromagnetic field strength measurements were carried out for 664 base station locations. Base station locations were classified into three categories: indoor, masts and locations with installations on buildings. Having in mind the large percentage (47 %) of sites with antenna masts, a detailed analysis of this location category was performed, and the measurement results were presented. It was concluded that the total electric field strength in the vicinity of base station antenna masts in no case exceeded 10 V m(-1), which is quite below the International Commission on Non-Ionizing Radiation Protection reference levels. At horizontal distances >50 m from the mast bottom, the median and maximum values were <1 and 2 V m(-1), respectively.

[State of the reproductive systemin in male rats of 1st generation obtained from irradiated parents and exposed to electromagnetic radiation (897 MHz) during embryogenesis and postnatal development].

PubMed

Vereshchako, G G; Chueshova, N V; Gorokh, G A; Naumov, A D

2014-01-01

The consequences of prolonged exposure to electromagnetic radiation from cellular phone (897 MHz, daily 8 h/day) in male rats of the 1st generation obtained from irradiated parents and subjected to prolonged exposure to electromagnetic radiation of the range of mobile communications during ontogeny and postnatal development were studied. It has been found that irradiation causes a decrease in the number of births of animals, changing the sex ratio towards the increase in the number of males. It had a significant impact on the reproductive system of males, accelerating their sexual development, revealed at the age of two months. Radiation from cell phones led to significant disproportions in the cell number at different stages of spermatogenesis. It increased the number of mature spermatozoa which decreased viability.

[Seasonal changes in tumor necrosis factor production in hibernating animals in normal conditions and under the effects of electromagnetic and ionizing radiation].

PubMed

Ogaĭ, V B; Novoselova, E G; Makar, V R; Kolaeva, S G

2002-01-01

Production of tumor necrosis factor (TNF) has been investigated in peritoneal macrophages and splenic T cells of Arctic Yakutian ground squirrel (Citellus Undulatus Pallas) upon in vitro action of electromagnetic and ionizing radiation during annual cycle. The significant activation of TNF production in the cells of awaken ground squirrels in winter and increasing level of the lymphokine production at spring-summer period has been indicated. The level of TNF production in splenic T cells was not changed during whole year. The electromagnetic radiation (EMR) of low intensity (8.15-18 GHz, 1 microW/cm2) induced an augmentation of both secretory and proliferative activity in TNF-producing cells. Ionizing radiation suppressed T cell proliferation, but the doses 2 and 5 Gy resulted in a significant stimulation of TNF production in T cells and macrophages.

Electromagnetic navigation-guided neuroendoscopic removal of radiation-induced intraforniceal cavernoma as a late complication of medulloblastoma treatment.

PubMed

Liby, Petr; Zamecnik, J; Kyncl, M; Zackova, J; Tichy, M

2017-11-01

Medulloblastoma is the most frequent malignant brain tumour in children. Radiation-induced cavernous haemangiomas (RICHs) are a known late complication of radiation exposure, especially in young children. We present a patient who underwent subtotal resection of posterior fossa medulloblastoma with subsequent chemotherapy and radiotherapy at the age of 10 years. A new lesion in the region of the left foramen of Monro appeared 16 years later. Based on the imaging results, metastasis or radiation-induced cavernoma was considered. The lesion had the same appearance on imaging as a rarely published intraventricular cavernoma of the foramen of Monro. Unlike the cavernoma of the foramen of Monro, this lesion was subependymal and intraforniceal. Using electromagnetic navigation and neuroendoscopy, the lesion was completely removed. Histopathological examination revealed a cavernous haemangioma. This is a unique case of intraforniceal paraforaminal cavernoma that was successfully removed endoscopically using electromagnetic neuronavigation and without neurological sequelae.

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.

Broadband mixing of $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases in photonic heterostructures with a one-dimensional loss/gain bilayer

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

Özgün, Ege; Serebryannikov, Andriy E.; Ozbay, Ekmel

Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enablingmore » $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission. In this report, broadband mixing of the $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/gain bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are then discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/gain medium, i.e., from epsilon-near-zero to high-epsilon regime.« less

Broadband mixing of [Formula: see text]-symmetric and [Formula: see text]-broken phases in photonic heterostructures with a one-dimensional loss/gain bilayer.

PubMed

Özgün, Ege; Serebryannikov, Andriy E; Ozbay, Ekmel; Soukoulis, Costas M

2017-11-14

Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enabling [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission. In this report, broadband mixing of the [Formula: see text]-symmetric and [Formula: see text]-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/gain bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/gain medium, i.e., from epsilon-near-zero to high-epsilon regime.

Broadband mixing of $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases in photonic heterostructures with a one-dimensional loss/gain bilayer

DOE PAGES

Özgün, Ege; Serebryannikov, Andriy E.; Ozbay, Ekmel; ...

2017-11-14

Combining loss and gain components in one photonic heterostructure opens a new route to efficient manipulation by radiation, transmission, absorption, and scattering of electromagnetic waves. Therefore, loss/gain structures enablingmore » $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues have extensively been studied in the last decade. In particular, translation from one phase to another, which occurs at the critical point in the two-channel structures with one-dimensional loss/gain components, is often associated with one-way transmission. In this report, broadband mixing of the $${\\mathscr{P}}{\\mathscr{T}}$$-symmetric and $${\\mathscr{P}}{\\mathscr{T}}$$-broken phases for eigenvalues is theoretically demonstrated in heterostructures with four channels obtained by combining a one-dimensional loss/gain bilayer and one or two thin polarization-converting components (PCCs). The broadband phase mixing in the four-channel case is expected to yield advanced transmission and absorption regimes. Various configurations are analyzed, which are distinguished in symmetry properties and polarization conversion regime of PCCs. The conditions necessary for phase mixing are then discussed. The simplest two-component configurations with broadband mixing are found, as well as the more complex three-component configurations wherein symmetric and broken sets are not yet mixed and appear in the neighbouring frequency ranges. Peculiarities of eigenvalue behaviour are considered for different permittivity ranges of loss/gain medium, i.e., from epsilon-near-zero to high-epsilon regime.« less

SU-F-T-264: VMAT QA with 2D Radiation Measuring Equipment Attached to Gantry

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

Fung, A

2016-06-15

Purpose: To introduce a method of VMAT QA by 2D measuring device. The 2D device is attached to the gantry throughout measurement duration. This eliminates error caused by the angular dependence of the radiation detectors. Methods: A 2D radiation measuring device was attached to the gantry of linear accelerator. The center of the detector plane was at the isocenter. For each patient plan, two verification plans were created for QA purpose. One was like an ordinary VMAT plan, to be used for radiation delivery. The other is a plan with gantry angle fixed at zero, so the dose distribution asmore » seen by the rotating 2D device. Points above 10% dose threshold were analyzed. Data is in tolerance if it fits within the 3 mm or 3% dose gamma criteria. For each patient, the plan was passed when 95% of all the points in the 2D matrix fit the gamma criteria. The following statistics were calculated: number of patient plans passed, percentage of all points passed, average percentage difference of all points. Results: VMAT QA was performed for patients during one year in our department, and the results were analyzed. All irradiation was with 6 MV photon beam. Each plan has calculated and measured doses compared. After collecting one year’s result, with 81 patient plans analyzed, all (100%) of the plans passed the gamma criteria. Of the points analyzed from all plans, 98.8% of all points passed. Conclusion: This method of attaching a 2D measuring device on the linac gantry proves to be an accurate way for VMAT QA. It is simple to use and low cost, and it eliminates the problem of directional dependence.« less

A novel model of interaction between high frequency electromagnetic non-ionizing fields and microtubules viewed as coupled two-degrees of freedom harmonic oscillators.

PubMed

Caligiuri, Luigi Maxmilian

2015-01-01

The question regarding the potential biological and adverse health effects of non-ionizing electromagnetic fields on living organisms is of primary importance in biophysics and medicine. Despite the several experimental evidences showing such occurrence in a wide frequency range from extremely low frequency to microwaves, a definitive theoretical model able to explain a possible mechanism of interaction between electromagnetic fields and living matter, especially in the case of weak and very weak intensities, is still missing. In this paper it has been suggested a possible mechanism of interaction involving the resonant absorption of electromagnetic radiation by microtubules. To this aim these have been modeled as non-dissipative forced harmonic oscillators characterized by two coupled "macroscopic" degrees of freedom, respectively describing longitudinal and transversal vibrations induced by the electromagnetic field. We have shown that the proposed model, although at a preliminary stage, is able to explain the ability of even weak electromagnetic radiating electromagnetic fields to transfer high quantities of energy to living systems by means of a resonant mechanism, so capable to easily damage microtubules structure.

Effect of electromagnetic microwave radiation on the growth of Ehrlich ascites carcinoma.

PubMed

Kryukova, O V; Pyankov, V F; Kopylov, A F; Khlebopros, R G

2016-09-01

Daily exposure of mouse recipients of Ehrlich ascites carcinoma to electromagnetic radiation of the microwave range leads to a change in the dynamics of tumor growth by decreasing the total number of cells. The number of tumor cells with blebbing morphological signs after microwave radiation increases gradually with tumor growth. The maximum content of tumor cells in the state of blebbing is observed during active proliferation in tumor-recipient mice of the control group (without irradiation).

Assessment of radiofrequency radiation within the vicinity of some GSM base stations in Ghana.

PubMed

Deatanyah, P; Amoako, J K; Fletcher, J J; Asiedu, G O; Adjei, D N; Dwapanyin, G O; Amoatey, E A

2012-08-01

A radiofrequency (RF) electromagnetic radiation safety survey had been carried out at public access points in 46 towns with 76 Global Systems for Mobile communication cell sites in two major cities in Ghana. The objective was to determine the levels of RF field in residential areas, schools and market places, and compare the measured results with the guidelines set by the International Commission of Non-Ionising Radiation (ICNIRP). Measurements were made with log-periodic antenna coupled with spectrum analyzer. The results varied from 0.85 to 1.07 mW m(-2) and 0.78 to 1.19 mW m(-2) for the transmission frequencies of 900 and 1800 MHz, respectively. The result generally shows a compliance with the ICNIRP limit of 0.024 % but was 108 times higher than a similar survey carried out in Ghana 2 y ago.

Evanescent radiation, quantum mechanics and the Casimir effect

NASA Technical Reports Server (NTRS)

Schatten, Kenneth H.

1989-01-01

An attempt to bridge the gap between classical and quantum mechanics and to explain the Casimir effect is presented. The general nature of chaotic motion is discussed from two points of view: the first uses catastrophe theory and strange attractors to describe the deterministic view of this motion; the underlying framework for chaos in these classical dynamic systems is their extreme sensitivity to initial conditions. The second interpretation refers to randomness associated with probabilistic dynamics, as for Brownian motion. The present approach to understanding evanescent radiation and its relation to the Casimir effect corresponds to the first interpretation, whereas stochastic electrodynamics corresponds to the second viewpoint. The nonlinear behavior of the electromagnetic field is also studied. This well-understood behavior is utilized to examine the motions of two orbiting charges and shows a closeness between the classical behavior and the quantum uncertainty principle. The evanescent radiation is used to help explain the Casimir effect.