Absence Of Electromagnetic Fields Research Articles

Electromagnetic field on a photothermal semiconducting voids medium under Lord–Shulman and refined multi-phase lag models in thermoelasticity

This study investigates the contemporary thermoelasticity theories in a photothermal semiconducting medium with voids influenced by the electromagnetic field. Boundary conditions of the phenomenon were based on the equations that regulate it concerning the stresses, carrier density, change in volume fraction field and temperature on the surface space. The equations were solved in normal mode technique, and the results are displayed by graphs. A comparison has been made with the findings of the literature when neglecting the new external parameters. The findings show that the presence or absence of electromagnetic field and carrier density significantly impacts on the phenomenon. From the results obtained, it is clear that the effects of electromagnetic field, carrier density, volume fraction and thermal relaxation times are very pronounced and applicable in diverse fields including geophysics, astronomy, engineering, biology, etc.

Coalescence sum rule and the electric charge- and strangeness-dependences of directed flow in heavy ion collisions

The rapidity-odd directed flows (v1) of identified hadrons are expected to follow the coalescence sum rule when the created matter is initially in parton degrees of freedom and then hadronizes through quark coalescence. A recent study has considered the v1 of produced hadrons that do not contain u or d constituent quarks. It has constructed multiple hadron sets with a small mass difference but given difference in electric charge Δq and strangeness ΔS between the two sides, where a nonzero and increasing Δv1 with Δq has been proposed to be a consequence of electromagnetic fields. In this study, we examine the consequence of coalescence sum rule on the Δv1 of the hadron sets in the absence of electromagnetic fields. We find that in general Δv1≠0 for a hadron set with nonzero Δq and/or ΔS due to potential v1 differences between u¯ and d¯ and between s and s¯ quarks. We further propose methods to extract the coefficients for the Δq- and ΔS-dependences of the direct flow difference, where a nonzero constant term would indicate the breaking of the coalescence sum rule. The extraction methods are then demonstrated with transport model results.

Conservative second-order accurate finite-difference scheme for the coupled Maxwell-Dirac equations

The recent development of nanoelectronic devices that incorporate Dirac materials has highly increased the need for adequate simulation and modelling tools. This paper introduces an accurate, multiphysics finite-difference time-domain method to solve the pertinent Maxwell-Dirac equations. The stability criterion for the Dirac equation with electromagnetic fields is derived, which reduces to the Courant-Friedrichs-Lewy condition in the absence of electromagnetic fields. Validation examples show the second-order accuracy of the novel fully coupled Maxwell-Dirac scheme and illustrate that total norm and energy are caonserved within a relative error of order 10−4. The method is applied to a ZrTe5 waveguide and it is found that even at low field strengths, the charge carriers can be accelerated to 80% of the Fermi velocity. Furthermore, the flexibility of the advocated method allows for the seamless integration into existing computational electromagnetics frameworks and the possible extension to higher-order schemes.

Resonant tunneling of deuteron-triton fusion in strong high-frequency electromagnetic fields

We investigate deuteron-triton (DT) fusion in the presence of linearly polarized strong electromagnetic fields in high-frequency limit, in which a complex spherical square-well potential is exploited to describe the nuclear potential. Within the framework of the Kramers-Henneberger (KH) transformation, we have calculated the total and angular differential fusion cross sections by investigating the asymptotical phase shifts of the Coulomb wavefunctions. With introducing a dimensionless quantity of $n_d$ representing the ratio of the particle quiver oscillation amplitude to the radius of nuclear potential, we find that, even though the tunneling probability of passing through the Coulomb repulsive potential keeps almost identical to that in the absence of electromagnetic fields, the peak of total fusion sections shows an apparent shift from the well known value of 110 keV to 78 keV for $n_d=0.01$. The angular differential cross sections also show some resonance peaks that shift from zero inclination angle to $\pi/2$ with increasing the parameter $n_d$. The corresponding astrophysical $S$-factors are found to be enhanced by several times in amplitudes. With the help of Wentzel-Kramers-Brillouin (WKB) approximate wavefunctions, the shape-resonance tunneling mechanism of the above findings are uncovered and some implications are discussed.

Quasi-Casimir coupling can induce thermal resonance of adsorbed liquid layers in a nanogap.

In a vacuum nanogap, phonon heat transfer can be induced by quasi-Casimir coupling in the absence of electromagnetic fields. However, it is unknown whether phonons can be transmitted across a nanogap via solid-like liquid layers adsorbed on solid surfaces. Here, we elucidate that phonon transmission across a nanogap can be induced by quasi-Casimir coupling via adsorbed liquid layers using classical nonequilibrium molecular dynamics simulation. We modulated the gap distance to verify the existence of quasi-Casimir coupling between interfacial solid-liquid or liquid-liquid layers. Thermal resonance can be induced between two liquid layers by quasi-Casimir coupling, agitating the co-occurrence of thermal resonance between interfacial solid layers, while a liquid monolayer disturbs the resonance. The thermal resonance between liquid layers results in a larger heat flux and thermal gap conductance compared with those in the vacuum gap case, while the liquid layer limits the acoustic phonon transmission in the interfacial solid layers. The fundamental understanding of quasi-Casimir heat transfer at the solid-liquid interface could pave the way for future nanoscale energy transport and thermal management.

Generalized polytropic models in Finch-Skea spacetime

In present article, we have formulated the new physical generalized polytropic models with anisotropic matter distribution in the absence of electromagnetic field. We have assumed the Finch-Skea spacetime to develop the models, which fulfill all the criteria for the physical adequacy. Distinct physical features of the obtained models have been examined and evaluated. Furthermore, the physical quantities are presented graphically to meet the physical conditions of viable astronomical models. These results can be reduced to the different cases of uncharged anisotropic fluid such as linear, quadratic and polytropic equations of state.

An electroplastic internal state variable (ISV) model for nonferromagnetic ductile metals

This study presents a multiphysics Internal State Variable (ISV) theory that couples the thermo-elasto-viscoplastic-damage model of Bammann with electroplasticity and other electricity-related electromagnetic phenomena. The model framework features internally consistent kinematics, thermodynamics, and kinetics. The abstraction of the developed ISV model can capture the full spectrum of multiphysics electro-mechanical behavior of the nonferromagnetic ductile metals. However, in the absence of electromagnetic fields the model reverts to the existing large deformation Bammann plasticity ISV model with the Horstemeyer damage ISV formalism.

Effective quantum kinetic theory for spin transport of fermions with collsional effects

We systematically derive the collision term for the axial kinetic theory, a quantum kinetic theory delineating the coupled dynamics of the vector/axial charges and spin transport carried by the massive spin-1/2 fermions traversing a medium. We employ the Wigner-function approach and propose a consistent power-counting scheme where the axial-charge distribution function, a non-conserved quantity for massive particles, is accounted as the first-order quantity in the ħ expansion, while the vector-charge distribution function the zeroth-order quantity. This specific power-counting scheme allows us to organize a reduced ħ expansion for the collision term and to formally identity the spin- diffusion effect and the spin-polarization effect at the same order. We confirm that the obtained collisional axial kinetic theory smoothly reduces to the chiral kinetic theory in the massless limit, serving as a consistency check. In the absence of electromagnetic fields, we further present the simplified axial kinetic equations suitable for tracking dynamical spin polarization of heavy and light fermions, respectively. As an application to the weakly coupled quark-gluon plasma at high temperature, we compute the spin-diffusion term for massive quarks within the leading-log approximation. The formal expression for the first- order terms provides a path toward evaluation of the spin polarization effect in quantum chromodynamics.

Syngas Production Improvement of Sugarcane Bagasse Conversion Using an Electromagnetic Modified Vacuum Pyrolysis Reactor

The trends and challenges of pyrolysis technology nowadays have shifted to low-temperature pyrolysis, which provides low-cost processes but high-yield conversion, with suitable H2/CO ratios for performing gas-to-liquid technology in the future. The present study has developed a modified vacuum pyrolysis reactor to convert sugarcane bagasse to gas products, including H2, CO2, CH4, and CO in the low-temperature process. The experimental design includes the effects of pyrolysis time, pyrolysis temperature, and applying a current as a function of the electromagnetic field. The result showed that 0.12 ng/µL, 0.85 ng/µL, and 0.31 ng/µL of hydrogen (H2), carbon dioxide (CO2), and carbon monoxide (CO) gases, respectively, started forming in the first 20 min at 210 °C for the pyrolysis temperature, and the gas product accumulated in the increase of pyrolysis time and temperature. In the absence of electromagnetic field, the optimum condition was obtained at 60 min and 290 °C of pyrolysis time and temperature, respectively, in which 20.98, 14.86, 14.56, and 15.78 ng/µL of H2, CO2, CH4, and CO were generated, respectively. However, this condition did not meet the minimum value of Fischer–Tropsch synthesis, since the minimum requirement of the H2/CO ratio is 2. Furthermore, applying the electromagnetic field performed a significant improvement, in which applying current ≥3A improved the gas product to 33.76, 8.71, 18.39, and 7.66 ng/µL of H2, CO2, CH4, and CO, respectively, with an H2/CO ratio above 2. The obtained result showed that applying electric current as an electromagnetic field provides a significant improvement, not only in boosting yield product, but also in performing the standard ratios of H2/CO in the gas–liquid conversion of syngas to liquid hydrocarbon. The result proves that applying an electromagnetic approach could be used as an alternative way to obtain efficiency and as a better process to convert biomass as a future energy source.

Enhanced deuterium-tritium fusion cross sections in the presence of strong electromagnetic fields

We investigate deuterium-tritium (DT) fusion cross sections in the presence of electromagnetic fields with high intensity and high frequency. With the help of the Kramers-Henneberger (KH) transformation, we show that the corresponding Coulomb barrier penetrability increases significantly due to the depression of the time-averaged potential barrier. As a result, we find that DT fusion cross sections can be enhanced depending effectively on a dimensionless quantity ${n}_{\mathrm{d}}$, which equals the ratio of the quiver oscillation amplitude to the geometrical touching radius of the deuterium and tritium nuclei. For ${n}_{\mathrm{d}}=9$, we predict that the fusion cross section is almost five times the value in the absence of electromagnetic fields, which implies that the famous Lawson criterion might be relaxed to some extent.

Geometrical unification of gravitation and electromagnetism

A theory which achieves a complete geometrical unification of gravitation and electromagnetism (GUGE) is presented. This new theory is based on a recent proposal of proper time redefinition that leads to the construction of a Riemann metric, which naturally unifies gravity and electromagnetism. The 5--dimensional Riemann metric which arises looks exactly the same as the one postulated in the Kaluza-Klein (KK) 5-dimensional theory. Nevertheless, there are deep differences between GUGE and KK. The GUGE metric is deduced while the KK metric is postulated. In the GUGE field theory there is no need to impose either of the so called "cylinder" or "curling of coordinates" conditions, because they emerge as direct consequences of the construction of the GUGE metric. The GUGE field equations are fully equivalent to Einstein--Maxwell equations, while KK field equations are not. The GUGE 5--dimensional (geodesic) equations are equivalent to the 4--dimensional (non--geodesic) equations for a charged particle moving in the presence of gravitational and electromagnetic fields, unlike the KK 5--dimensional (geodesic) equations which are not and, in addition, yield non--gauge covariant geodesic equations. No extra scalar field appears in GUGE. The physical interpretation of the fifth dimension and of the role of the extra field in KK (internal coordinate in GUGE) are totally different in both approaches. Finally, GUGE results include electric charge conservation, electric charge quantization and electric charge contribution to the energy of charged particles even in the absence of electromagnetic fields, which implies (the observed fact) that there are no massless electrically charged particles in Nature, unlike the prevailing treatments of KK theories.

Some features of semiclassical chiral transport in rotating frames

Semiclassical chiral kinetic theories in the presence of electromagnetic fields as well as vorticity can be constructed by means of some different relativistic or nonrelativistic approaches. To cover the noninertial features of rotating frames one can start from the modified quantum kinetic equation of Wigner function in Minkowski spacetime. It provides a relativistic chiral transport equation whose nonrelativistic limit yields a consistent three-dimensional kinetic theory which does not depend explicitly on spatial coordinates. Recently a chiral transport equation in curved spacetime has been proposed and its nonrelativistic limit in rotating coordinates was considered in the absence of electromagnetic fields. We show that the modified theory can be extended to curved spacetime. The related particle current density and chiral transport equation for an inertial observer in the rotating frame are derived. A novel three-dimensional chiral kinetic transport equation is established by inspecting the nonrelativistic limit of the curved spacetime approach in the rotating frame for a comoving observer in the presence of electromagnetic fields. It explicitly depends on spatial coordinates. We prove that it is consistent with the chiral anomaly, chiral magnetic and vortical effects.

Different profiles of the mRNA levels of DNA repair genes in MCF-7 and SH-SY5Y cells after treatment with combination of cisplatin, 50-Hz electromagnetic field and bleomycin

Neurotoxicity is known to be a major dose-limiting adverse effect of cisplatin (CDDP), alone or in combination with other chemicals. DNA repair capacity serve as a neuroprotective factor against CDDP. The purpose of this study was to evaluate the effect of 50-Hz electromagnetic field (EMF) in combination with CDDP and bleomycin (Bleo) on expression of some of DNA repair genes (GADD45A, XRCC1, XRCC4, Ku70, Ku80, DNA-PKcs and LIG4) in MCF-7 (breast cancer) and SH-SY5Y (neuroblastoma) cell lines. MCF-7 and SH-SY5Y cells were pre-treated with CDDP in the presence or absence of EMF and then exposed to different concentration of Bleo. EMF (0.50mT intensity) was used in the intermittenet pattern of “15min field on/15min field off” with 30min total exposure. Cell viability assay was done and then the transcript levels of the examined genes were measured using quantitative real-time PCR in “CDDP+Bleo” and “CDDP+EMF+Bleo” treatments. Our results indicated that MCF-7 cells treated with “CDDP+EMF+Bleo” showed more susceptibility compared with “CDDP+Bleo” treated ones, while SH-SY5Y susceptibility was not changed between the two treatments. The represented data indicated that MCF-7 and SH-SY5Y cells showed non-random disagreement in DNA repair gene expression in 11 conditions (out of 14 conditions) with each other (χ2=4.52, df=1, P=0.033). This finding can be promising for sensitizing breast cancer cells while protecting against CDDP induced neuropathy in cancer patients.

Combining the Absence of Electromagnetic Fields and Mirror Therapy to Improve Outcome for Persons with Lower-Limb Vascular Amputation: Letter to the Editor and in Response to Shannon Fillmore’s Letter to the Editor

Combining the Absence of Electromagnetic Fields and Mirror Therapy to Improve Outcome for Persons with Lower-Limb Vascular Amputation: Letter to the Editor and in Response to Shannon Fillmore’s Letter to the Editor

Re: Combining the Absence of Electromagnetic Fields and Mirror Therapy to Improve Outcome for Persons with Lower-Limb Vascular Amputation: Letter to the Editor

Re: Combining the Absence of Electromagnetic Fields and Mirror Therapy to Improve Outcome for Persons with Lower-Limb Vascular Amputation: Letter to the Editor

Self-accelerating Dirac particles and prolonging the lifetime of relativistic fermions

By engineering the electron wavefunction it is possible to create Aharonov–Bohm-like phases and relativistic effects such as length contraction and time dilation in a non-relativistic setting and in the absence of electromagnetic fields.

Effect of Ionizing and Non-ionizing Radiation On Amalgam, Composite and Zirconomer Based Restorations.

Dear Editor, With great interest we read the article by Patel et al., entitled “An invitro Evaluation of Microleakage of Posterior Teeth Restored with Amalgam, Composite and Zirconomer–A Stereomicroscopic Study” [1] that is published in the July issue of the Journal of Clinical and Diagnostic Research (Vol-9(7): ZC65-ZC67, 2015). In this article, the authors performed an in vitro stereomicroscopic study to evaluate the microleakage of posterior teeth restored with amalgam, composite and zirconomer. In their study, cavities prepared on the occlusal surface, were restored with amalgam, composite and zirconomer. These researchers reported that based on their findings, zirconomer revealed the highest level of microleakage compared to composite and amalgam. The microleakage of composite was moderate and amalgam showed the minimum level of microleakage. This paper seems to have a serious shortcoming. Substantial evidence shows that in the studies on microleakage of amalgam, the challenging issue of exposure to different sources of electromagnetic fields (e.g. Wi-Fi, mobile phones and mobile base stations, or even electrical household appliances such as hair dryers, electric shavers and vacuum cleaners) and their effects on enhanced microleakage should be taken into account. Over the past several years, our lab at the Ionizing and Non-ionizing Radiation Protection Research Center (INIRPRC) has performed extensive experiments on the health effects of exposure of animal models and humans to different sources of electromagnetic fields (EMFs) such as cellular phones [2–9], mobile base stations [10], mobile phone jammers [11], laptop computers [12], radars [3], dentistry cavitrons [13] and MRI [14,15]. Our first report on the role of exposure to MRI or microwave radiation emitted by mobile phones in enhancing the release of mercury from dental amalgam restoration was published in 2008 [8]. Due to some limitations in this early study, we have recently investigated the effect of exposure to relatively stronger magnetic fields (0.25 T in our previous report versus 1.5 T in our recent study). Interestingly, this study confirmed our previous findings that the release of mercury from amalgam fillings can be enhanced by exposure to EMFs [16]. We have also shown that some of the papers which reported no increased release of mercury after MRI, may have some methodological flaws [17]. On the other hand, microleakage studies also provide further evidence that supports the biologically detrimental effect of MRI on increasing the microleakage of dental amalgam fillings [18,19]. As there is no reports indicating that exposure of other filling materials such as composites to EMFs enhances the microleakage, we believe that the significant role of rapidly increasing exposure to EMFs in increasing amalgam microleakage is not addressed in the study of Patel et al., In this light, to obtain more reliable results, the comparison of microleakage of amalgam and non-amalgam filling materials should be performed in both presence and absence of EMFs. We hope that these comments will provide evidence for broader understanding of the challenging issue of enhanced dental amalgam microleakage due to exposure to EMFs.

Low frequency electromagnetic field reduces β-adrenergic response in murine cardiomyocytes

In the modern society, concerns have been raised about possible adverse effects of exposure to low frequency electromagnetic field (ELF) on biological systems. Many research groups are working in this field, but the obtained results are often contradictory and cannot be reproduced by an experimental point of view in different laboratories, preventing definitive conclusions (Kheifets L. et al., 2007). In this work, the ELF was generated by a bioreactor that produced a variable magnetic field of 0-3.3 mT at a frequency of 75 Hz. The ELF was applied to cultures of murine neonatal cardiomyocytes to study several biological parameters. Neonatal cardiomyocytes are able to form spontaneously beating syncytia (Fassina L. et al., 2011). In basal conditions and after a β-adrenergic stimulation with Isoproterenol, a short exposure to ELF induced a decrease of contraction rate, Ca2+ transients, force of contraction and energy consumption. ELF did not modify frequency of contraction after stimulation with Forskolin and Norepinephrine, suggesting a specific effect of ELF on β-adrenergic receptors. Isolated cardiomyocytes were cultured in monolayer for 48 hours in the presence or absence of ELF, to investigate the effects of the ELF exposure on cell viability, cell size and differentiation. Immunofluorescence experiments showed that the ELF decreased the percentage of mature cardiomyocytes without having effects on cell size and morphology. Moreover, the ELF caused a decrease of binucleated cardiomyocytes, indicating possible differentiation defects. In conclusion these data show that a short exposure to ELF induces a decrease on β-adrenergic response while a long exposure to ELF influences the cell viability and the differentiation of cardiomyocytes.

Electromagnetic fields (UHF) increase voltage sensitivity of membrane ion channels; possible indication of cell phone effect on living cells

The effects of ultra high frequency (UHF) nonionizing electromagnetic fields (EMF) on the channel activities of nanopore forming protein, OmpF porin, were investigated. The voltage clamp technique was used to study the single channel activity of the pore in an artificial bilayer in the presence and absence of the electromagnetic fields at 910 to 990 MHz in real time. Channel activity patterns were used to address the effect of EMF on the dynamic, arrangement and dielectric properties of water molecules, as well as on the hydration state and arrangements of side chains lining the channel barrel. Based on the varied voltage sensitivity of the channel at different temperatures in the presence and absence of EMF, the amount of energy transferred to nano-environments of accessible groups was estimated to address the possible thermal effects of EMF. Our results show that the effects of EMF on channel activities are frequency dependent, with a maximum effect at 930 MHz. The frequency of channel gating and the voltage sensitivity is increased when the channel is exposed to EMF, while its conductance remains unchanged at all frequencies applied. We have not identified any changes in the capacitance and permeability of membrane in the presence of EMF. The effect of the EMF irradiated by cell phones is measured by Specific Absorption Rate (SAR) in artificial model of human head, Phantom. Thus, current approach applied to biological molecules and electrolytes might be considered as complement to evaluate safety of irradiating sources on biological matter at molecular level.

Viscous Accreting Magnetofluids around a Static Compact Object in Final Stages of Accretion Flow

Abstract The dynamics of the stationary axisymmetric configuration of accreting magnetofluids surrounding a non-rotating compact object in the final stages of accretion flow is presented here. We discuss two classes of solutions for the angular momentum: a Keplerian solution, which demands no accretion flow for the fluids, and a non-Keplerian solution, which requires a radial inflow velocity for the matter. For the special case of no presence of electromagnetic fields, two sets of self-consistent analytical solutions of fully relativistic fluid equations are obtained separately for two different equations of state. The effect of the bulk viscosity coefficient on the physical functions was investigated for each state, as well as the bounds that exert on the free parameters due to last stages of the accretion-flow condition. To resolve the magnetohydrodynamical equations, we were inspired by previous sets of solutions, since the magnetofluid equations are just the same as the fluid ones in the case of vanishing electromagnetic fields. The azimuthal current in magnetofluids doesn’t modify the dipolar configuration of the central object magnetic field, owing to the lack of a finite resistivity. The presence of this magnetic field doesn’t affect the azimuthal velocity of the plasma, but does slow down its radial inflow, and decrease the density and pressure of the plasma. Despite the role importance of the bulk viscosity on the fluids’ dynamics in the absence of electromagnetic fields, exerting the magnetic field decreases this role.