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Current limits for exposures to nonionizing electromagnetic fields (EMF) are set, based on relatively short-term exposures. Long-term exposures to weak EMF are not addressed in the current guidelines. Nevertheless, a large and growing amount of evidence indicates that long-term exposure to weak fields can affect biological systems and might have effects on human health. If they do, the public health issues could be important because of the very large fraction of the population worldwide that is exposed. We also discuss research that needs to be done to clarify questions about the effects of weak fields. In addition to the current short-term exposure guidelines, we propose an approach to how weak field exposure guidelines for long-term exposures might be set, in which the responsibility for limiting exposure is divided between the manufacturer, system operator, and individual being exposed. Bioelectromagnetics. © 2020 Bioelectromagnetics Society.

We investigate the effects of the anomalous magnetic moment (AMM) in the EoS of a fermion system in the presence of a magnetic field. In the region of strong magnetic fields ($B>m^2$) the AMM is found from the one-loop fermion self-energy. In contrast to the weak-field AMM found by Schwinger, in the strong magnetic field case, the AMM depends on the Landau level (LL) and decreases with it. The effects of the AMM in the EoS at intermediate-to-large fields can be found introducing the one-loop, LL-dependent AMM in the effective Lagrangian that is then used to find the thermodynamic potential of the system. We compare the plots of the parallel and perpendicular pressures versus the magnetic field in the strong field region considering the LL-dependent AMM, the Schwinger AMM, and no AMM at all. The results clearly show a separation between the physical magnitudes found using the Schwinger AMM and the LL-dependent AMM. This is an indication of the inconsistency of considering the Schwinger AMM beyond the weak field region $B< m^2$ where it was originally found. The curves for the EoS, pressures and magnetization at different fields give rise to the well-known de Haas van Alphen oscillations, associated to the change in the number of LL contributing at different fields.

The purpose of the current work is the formulation of two different (algorithmic) models for multiscale inelastic materials whose behavior is influenced by the evolution of inelastic microstructure and the corresponding material or internal lengthscales. The two models are compared with each other, depending in particular on how the inelastic deformation and dislocation density are modeled. The work is a first extension of the investigation in Klusemann et al. [1] to two-dimensions. In the first model, the corresponding displacement and inelastic local deformation are modeled as global via weak field relations, and the dislocation density is a local quantity and solved for via a strong field relation. In the second model, displacement and dislocation density are modeled as global, and the inelastic deformation as local, in this sense. The influence for the modeling results is discussed. (© 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)

Metabolism of bees (Apis mellifica L.) in 50 Hz high-tension field Bees in 50 Hz high-voltage AC-field show an increase of the metabolism rate following an increase of motor activity. Caged beegroups under weak field strength (lower than approx. 10 KV/m) show differing metabolic rates. By medium field strength (approx. 20 KV/m-40 KV/m) the metabolic rate increases relative to the field strength. By high field strength (over approx. 50 KV/m) the bees are cause to sting one another. Zusammenfassung Bienen im 50-Hz-Hochspannungsfeld zeigen einen erhohten Stoffwechsel infolge gesteigerter motorischer Aktivitat. Bei geringen Feldstarken (unter ca. 10 KV/m) ist die Stoffwechselerhohung bei verschiedenen gekafigten Bienengruppen nicht einheitlich. Bei mittleren Feldstarken (ca. 20 KV/m-40 KV/m) ist die Stoffwechselerhohung mit der Feldstarke korreliert. Bei hohen Feldstarken (uber ca. 50 KV/m) erfolgt gegenseitiges Abstechen.

We calculate the thermal Hall conductivity of YBa2Cu3O6.99 by using Kubo formula approach. The longitudinal thermal conductivity, Kxx,is calculated and then by the relation between Kxx and Kxy the thermal Hall conductivity is evaluated. Our results show an increase in the thermal Hall conductivity with the applied field at low temperatures and weak field, i.e. Kxy ∼ T √H. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The photo-generated time-of-flight electron mobility measurements in 2,5-dibenzthiazolyl thiophene show weak field dependent high electron mobility, typically of the order of 1.21 × 10 -4 cm 2 /Vs at 2.5 x 10 5 V/cm, which is two orders of magnitude higher than that of Alq 3 complex.

A quantitative model is proposed for computing the dependence on the interecho time of the NMR relaxation rate in iron-rich gray matter obtained with a Carr-Purcell-Meiboom-Gill sequence. The model consists of representing oligodendrocytes as identical magnetic spheres arranged in a spatially random pattern, and in approximating water diffusion as isotropic and unrestricted. Predictions of the model are calculated numerically using a Monte Carlo technique and, for the weak field limit, using an analytic formula. The model is shown to provide a good fit to experimental measurements of in vitro samples of monkey brain at field levels of 1.0 T and 1.5 T. These field levels are not sufficient to fully determine the model parameters, but it is argued that this may be possible at 3.0 T. The model is potentially of value for multiple-spin-echo MRI studies of iron-related neurodegenerative disorders, such as Parkinson's disease. In particular, the model can be applied to correlate MRI data with the cellular distribution of iron in gray matter. Magn Reson Med 46:159–165, 2001. © 2001 Wiley-Liss, Inc.

In order to assess the effects of weak-field magnetic stimulation on brain electrical activity in epileptics, three patients suffering from mesial temporal lobe epilepsy (MTLE) were exposed to DC magnetic fields of 0.9 and 1.8 millitesla (mT). The EEG activity was recorded simultaneously from intracranial electrodes inserted through the foramen ovale (FO) and scalp electrodes. Significant enhancement of interictal epileptiform activity was observed in two patients, while in one patient, magnetic stimulation resulted in the cessation of interictal spike/wave trains.

The field dependence of the electron mobility is measured in Te at 77 K using an electron drift technique. In the range up to 80 V/cm the electron mobility is nearly field-independent. In the range from 100 to 400 V/cm the mobility lowers with E−0.6. At fields above 600 V/cm only a weak field strength dependence is observed. The zero field mobility ratio of electrons and holes at 77 K is about (3.55 ± 0.25) independently of the hole mobility of the samples. Mit einer Elektronendrift-Technik wird die Feldstarkeabhangigkeit der Elektronenbeweglichkeit in Te bei 77 K untersucht. Im Feldstarkebereich bis zu 80 V/cm ist die Elektronenbeweglichkeit nahezu feldunabhangig. Im Feldstarkebereich zwischen 100 und 400 V/cm sinkt die Beweglichkeit proportional zu E−0.6. Oberhalb 600 V/cm wird nur noch eine schwache Feldabhangigkeit beob-aohtet. Das Verhaltnis der Elektronen- und Locherbeweglichkeit bei 77 K im schwachen elektri-schen Feld ist etwa 3,55 ± 0,25, unabhangig von der Locherbeweglichkeit der Proben.

The weak-field thermomagnetic coefficients of bismuth with heat current in the trigonal direction have been measured in the range of temperatures from 10 to 65 K. The data are analysed in terms of the symmetry restrictions imposed by the 3m point group. The temperature dependences of the coefficients point to a diffusion thermoelectric power down to temperatures which depend on the coefficient in question, the highest temperature being around 40 K. On a mesure les coefficients thermomagnetique a champs faibles dans le bismuth avec un flux de chaleur trigonal a temperatures entre 10 et 65 K. Les resultats experimentaux ont ete analyses suivant les restrictions de la symetrie du groupe 3m. Les variations des coefficients avec la temperature indiquent un pouvoir thermoelectrique du diffusion jusqu'a temperatures qui dependent de le coefficient en question, la temperature la plus elevee est environ 40 K.

A formulation for obtaining the galvanomagnetic coefficients for the D2h group is presented based on Wasscher's method for the electrical measurements. The method is suitable to yield all possible transport coefficients. Es wird eine Methode zur Gewinnung der galvanomagnetischen Koeffizienten der D2h-Gruppe angegeben, die auf Wasschers Methode fur elektrische Messungen beruht. Dieses Verfahren erlaubt, alle moglichen Transportkoeffizienten zu erhalten.

The clay minerals kaolin and bentonite are demonstrated as gastrointestinal contrast agents for MRI. Weak field dependence of the relaxation efficiency assures effectiveness of these agents at all field strengths in clinical use. These agents eliminate signals from their immediate environment and are not toxic.

The imaginary part of the interband dielectric function of a heavily doped semiconductor in the presence of a uniform electric field is calculated. The expression is calculated directly from the Kubo equation in the one-electron approximation. The average over the impurity coordinates is carried out by means of the cluster integral technique and small time approximation. Under the weak field and low temperature approximation, the dielectric function of a heavily doped semiconductor in the presence of a uniform electric field may be calculated explicitly. It can be expressed in two terms; one is the Franz-Keldysh effect and the other is due to the impurities in the semiconductors. The results are given for both n- and p-type semiconductors. Es wird der Imaginarteil der. Interband-Dielektrizitatsfunktioneines stark dotierten Halbleiters in einem homogenen elektrischen Feld berechnet. Der Ausdruck wird direkt aus der Kubogleichung in der Ein-Elektronen-Naherung berechnet. Die Mittelung uber die Storstellenkoordinaten wird mit der Cluster-Integraltechnik und der Naherung kleiner Zeiten durchgefuhrt. Bei schwachen Feldern und in der Tieftemperaturnaherung last sich die Dielektrizitatsfunktion eines stark dotierten Halbleiters bei Anwesenheit eines homogenen elektrischen Feldes explizit berechnen. Sie kann in zwei Termen ausgedruckt werden, davon ist einer der Franz-Keldysh-Effekt und der andere wird durch die Storstellen in Halbleitern hervorgerufen. Ergebnisse werden sowohl fur n- als auch fur p-leitende Halb- leiter angegeben.

A closed analytical expression for multiphoton transition rate, in direct gap crystals, is obtained from a non-perturbative approach in theweak-field limit. This scheme is related to an approximate high order perturbation theory and compared with tunneling-like theories as proposed by Keldysh. The accuracy and the limitations of the use of the saddle-point in this type of methods are discussed. Es wird ein geschlossener analytischer Ausdruck fur die Multiphoton-Ubergangsrate in Kristallen mit direkter Bandlucke ohne Storungsverfahren im Grenzfall schwachen Feldes erhalten. Dieses Verfahren ist mit einer Storungstheorie hoher Ordnung verknupft und wird mit tunneleffektahnlichen Theorien, wie sie von Keldysch vorgeschlagen werden, verglichen. Genauigkeit und Grenzen der Benutzung des Sattelpunkts bei diesen Methoden werden diskutiert.

The galvanomagnetic properties of Se-doped tellurium measured in the temperature range from 1.2 to 77 K were compared with those of undoped tellurium. The hole concentrations were not changed by the Se-doping (from several p.p.m. t o 1500 p.p.m. (0.15%)). The temperature dependence of the weak field Hall coefficient was greatly changed by doping and showed two peaks at 4 to 6 and 20 to 25 K in sufficiently Se-doped samples. The temperature dependence of the resistivity was also changed and showed a broad peak around 15 K. These results were interpreted on the base of a two-carrier model in which the impurity band-like states are degenerate with the valence band as was proposed previously and the number of the states increases with the Se-concentration. This means that the impurity band-like states of undoped tellurium may also consist of isoelectronic impurity states due to the residual Se-impurity. The nature of the short range potential of the Se-impurity in tellurium is discussed. Die galvanomagnetischen Eigenschaften von Se-dotiertem Tellur wurden mit Daten von nicht-dotiertem Tellur im Temperaturbereich von 1,2 bis 77 K verglichen. Die Locherkonzentrationen wurden durch die Se-Dotierung (einige p.p.m. bis 1500p.p.m (0,150%)) nicht geandert. Die Temperaturabhangigkeit der Hall-Konstanten bei schwachem Feld wurde durch die Dotierung stark geandert und zeigt zwei Maxima bei 4 bis 6 und 20 bis 25 K in genugend Se-dotiertem Tellur. Die Temperaturabhangigkeit des Widerstandes andert sich auch und zeigt ein breites Maximum bei etwa 15 K. Die Ergebnisse werden auf der Grundlage eines Zwei-Trager-Modells erklart, in dem die Zustande des „Verunreinigungsbandes” mit dem Valenzband entartet sind, wie bereits vorgeschlagen wurde, und die Anzahl der Zustande mit der Se-Konzentration zunimmt. Das bedeutet, das die Zustande des „Verunreinigungsbandes” von nicht-dotiertem Tellur auch aus den Zustanden der isoelektronischen restlichen Se-Storstellen bestehen konnen. Es wird die Natur des kurzreichweitigen Potentials der Se-Storstellen in Tellur diskutiert.