Glucose consume and growth of E. coli under electromagnetic field

E. coli,em caldo glicosado,foi submetida a campo eletromagnético de intensidade 5G, gerado por fonte de tensão alternada de 60 Hz . Os crescimento e consumo de glicose foram avaliados através do teste não-paramétrico de Mann-Whitney para comparação de dois grupos. Após 8 h de exposição encontraram-se menor valor da glicose residual e maior turbidez nos tubos expostos ao campo evidenciando efeito positivo deste. A causa deste efeito no consumo da glicose pode ser pela estimulação de sistema de transporte de glicose, como a Difusão Facilitada ou por um tipo de fenômeno chamado ressonância ciclotrônica. O aumento do crescimento pode ser pelo encurtamento da lag phase e estimulação da log phase.

Quantization of the electromagnetic field outside static black holes and its application to low-energy phenomena

We discuss the Gupta-Bleuler quantization of the free electromagnetic field outside static black holes in the Boulware vacuum. We use a gauge which reduces to the Feynman gauge in Minkowski spacetime. We also discuss its relation with gauges used previously. Then we apply the low-energy sector of this held theory to investigate some low-energy phenomena. First, we discuss the response rate of a static charge outside the Schwarzschild black hole in four dimensions. Next, motivated by string physics, we compute the absorption cross sections of low-energy plane waves for the Schwarzschild and extreme Reissner-Nordstrom black holes in arbitrary dimensions higher than three.

Electromagnetic field at finite temperature: A first order approach

In this work we study the electromagnetic field at finite temperature via the massless DKP formalism. The constraint analysis is performed and the partition function for the theory is constructed and computed. When it is specialized to the spin 1 sector we obtain the well-known result for the thermodynamic equilibrium of the electromagnetic field. (c) 2006 Elsevier B.V. All rights reserved.

Free electromagnetic field in Riemannian space-time via DKP theory

We study the massless Duffin-Kemmer-Petiau (DKP) equation in Riemannian space-times, particularly the massless spin 1 sector which reproduces the free Maxwell's equations.

Electromagnetic field in Lyra manifold: a first order approach

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

GREEN-FUNCTION FOR A SPIN-1/2 PARTICLE IN AN EXTERNAL PLANE-WAVE ELECTROMAGNETIC-FIELD

The Green function for a spin-1/2 charged particle in the presence of an external plane wave electromagnetic field is calculated by algebraic techniques in terms of the free-particle Green function.

The propagator for a charged oscillator with a time-dependent mass in a time-varying electromagnetic field

We make a change of variables and a time reparametrization in the Schrödinger equation in order to obtain the propagator of a charged oscillator with a time-dependent mass and frequency under the influence of time-varying electric and magnetic fields, in terms of the simple propagators of harmonic oscillators with constant frequencies and masses. We also discuss the Jackiw transformation and others as a particular case of ours. © 1991.

Energy and momentum for the electromagnetic field described by three outstanding electrodynamics

A prescription for computing the symmetric energy-momentum tensor from the field equations is presented. The method is then used to obtain the total energy and momentum for the electromagnetic field described by Maxwell electrodynamics, Born-Infeld nonlinear electrodynamics, and Podolsky generalized electrodynamics, respectively. © 1997 American Association of Physics Teachers.

Torsion and the electromagnetic field

In the framework of the teleparallel equivalent of general relativity, we study the dynamics of a gravitationally coupled electromagnetic field. It is shown that the electromagnetic field is able not only to couple to torsion, but also, through its energy-momentum tensor, produce torsion. Furthermore, it is shown that the coupling of the electromagnetic field with torsion preserves the local gauge invariance of Maxwell's theory.

Duality in a fermionlike formulation for the electromagnetic field

We employ the Dirac-like equation for the gauge field proposed by Majorana to obtain an action that is symmetric under duality transformation. We also use the equivalence between duality and chiral symmetry in this fermionlike formulation to show how the Maxwell action can be seen as a mass term. ©2000 The American Physical Society.

Schwinger's principle and gauge fixing in the free electromagnetic field

A manifestly covariant treatment of the free quantum eletromagnetic field, in a linear covariant gauge, is implemented employing Schwinger's variational principle and the B-field formalism. It is also discussed the Abelian Proca model as an example of a system without constraints. © Società Italiana di Fisica.

Biomass burning fuel consumption rates: a field measurement database

Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. Fuel consumption (FC) depends on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and estimates are becoming more reliable due to improved algorithms and sensors, FC is usually modeled or taken selectively from the literature. We compiled the peerreviewed literature on FC for various biomes and fuel categories to understand FC and its variability better, and to provide a database that can be used to constrain biogeochemical models with fire modules. We compiled in total 77 studies covering 11 biomes including savanna (15 studies, average FC of 4.6 t DM (dry matter) ha 1 with a standard deviation of 2.2), tropical forest (n = 19, FC = 126 +/- 77), temperate forest (n = 12, FC = 58 +/- 72), boreal forest (n = 16, FC = 35 +/- 24), pasture (n = 4, FC = 28 +/- 9.3), shifting cultivation (n = 2, FC = 23, with a range of 4.0-43), crop residue (n = 4, FC = 6.5 +/- 9.0), chaparral (n = 3, FC = 27 +/- 19), tropical peatland (n = 4, FC = 314 +/- 196), boreal peatland (n = 2, FC = 42 [42-43]), and tundra (n = 1, FC = 40). Within biomes the regional variability in the number of measurements was sometimes large, with e. g. only three measurement locations in boreal Russia and 35 sites in North America. Substantial regional differences in FC were found within the defined biomes: for example, FC of temperate pine forests in the USA was 37% lower than Australian forests dominated by eucalypt trees. Besides showing the differences between biomes, FC estimates were also grouped into different fuel classes. Our results highlight the large variability in FC, not only between biomes but also within biomes and fuel classes. This implies that substantial uncertainties are associated with using biome-averaged values to represent FC for whole biomes. Comparing the compiled FC values with co-located Global Fire Emissions Database version 3 (GFED3) FC indicates that modeling studies that aim to represent variability in FC also within biomes, still require improvements as they have difficulty in representing the dynamics governing FC.

A Non-Destructive Testing Based on Electromagnetic Measurements and Neural Networks for the Inspection of Concrete Structures

This paper presents a new non-destructive testing (NDT) for reinforced concrete structures, in order to identify the components of their reinforcement. A time varying electromagnetic field is generated close to the structure by electromagnetic devices specially designed for this purpose. The presence of ferromagnetic materials (the steel bars of the reinforcement) immersed in the concrete disturbs the magnetic field at the surface of the structure. These field alterations are detected by sensors coils placed on the concrete surface. Variations in position and cross section (the size) of steel bars immersed in concrete originate slightly different values for the induced voltages at the coils.. The values for the induced voltages were obtained in laboratory tests, and multi-layer perceptron artificial neural networks with Levemberg-Marquardt training algorithm were used to identify the location and size of the bar. Preliminary results can be considered very good.

Numerical simulation of magnetic field enhanced plasma immersion ion implantation

The behavior of plasma and sheath characteristics under the action of an applied magnetic field is important in many applications including plasma probes and material processing. Plasma immersion ion implantation (PIII) has been developed as a fast and efficient surface modification technique of complex shaped three-dimensional objects. The PIII process relies on the acceleration of ions across a high-voltage plasma sheath that develops around the target. Recent studies have shown that the sheath dynamics is significantly affected by an external magnetic field. In this work we describe a two-dimensional computer simulation of magnetic field enhanced plasma immersion implantation system. Negative bias voltage is applied to a cylindrical target located on the axis of a grounded cylindrical vacuum chamber filled with uniform nitrogen plasma. An axial magnetic field is created by a solenoid installed inside the cylindrical target. The computer code employs the Monte Carlo method for collision of electrons and neutrals in the plasma and a particle-in-cell (PIC) algorithm for simulating the movement of charged particles in the electromagnetic field. Secondary electron emission from the target subjected to ion bombardment is also included. It is found that a high-density plasma region is formed around the cylindrical target due to the intense background gas ionization by the magnetized electrons drifting in the crossed ExB fields. An increase of implantation current density in front of high density plasma region is observed. (C) 2007 Elsevier B.V. All rights reserved.

Atomic radiative transitions in thermo field dynamics

In this work we rederive the Lamb-Retherford energy shift for an atomic electron in the presence of a thermal radiation. Using the Dalibard, Dupont-Roc and Cohen-Tannoudji (DDC) formalism, where physical observables are expressed as convolutions of suitable statistical functions, we construct the electromagnetic field propagator of thermo field dynamics in the Coulomb gauge in order to investigate finite temperature effects on the atomic energy levels. In the same context, we also analyze the problem of the ground state stability.