Volume 3 Issue 2

Authors: Anastasia S. Safigianni; Aristotle M. Tsimtsios

Abstract: This paper investigates the electric and magnetic fields created due to the operation of roof-mounted photovoltaic units. For this purpose the most recent reference levels for safe general public and occupational exposure given in the guidelines of the International Commission on Non-Ionizing Radiation Protection are first presented. Basic constructional and operational data of the rooftop photovoltaic installations are examined follow, as well as a description of the measurement process. Electric and magnetic field measurements in typical photovoltaic units with different nominal powers and inverter types (single or three-phase) are performed under convenient weather conditions that ensure maximum electricity production. The main measurement results are evaluated according to the reference levels for safe public exposure, and the conclusion finally derived is that the examined fields are not dangerous and, therefore, are no cause for concern among the public.

Keywords: Electric and Magnetic Field Measurements; Reference Levels; Rooftop Photovoltaic Units; Safe Public Exposure

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Authors: Ireneusz Kubiak

Abstract: In the era of technological advance in development of electronic equipment and its widespread application for everyday use, the issues related to protection of information against electromagnetic penetration become the matters of key importance. Each piece of equipment that is used for processing confidential information may happen to be a source of undesired emissions. However, due to design solutions applied to engineering of such devices, the levels of compromising emission signals are very low. To evaluate vulnerability of such equipment to eavesdropping, it is necessary to apply methods that enable picking up substantial information that is hidden in noise. In particular, it refers to signals that are correlated with signals of graphic transmission tracks of computers since capturing such signals enables reproduction of images that are displayed on the screen of the “eavesdropped” computer. Use of the methods that are suitable for digital processing of images, even modified for needs of successful electromagnetic infiltration, is insufficient to achieve the desirable results. Hence, it is necessary to seek for other more powerful and efficient methods, where the method of two-dimensional correlation between the pattern image and fragments of the images subjected to the analysis seems to be the most promising one, where the images can be reproduced from the compromising emanation with use of the half-tone screening method. For such cases, the correlation factor never reaches the levels that correspond to a strong or even a weak correlation since its values for those fragments of the images under the analysis that comprise signs consistent with signs of the pattern reach the values of about 0.07. Therefore, one has to adopt a certain criterion that makes it possible to classify recognized fragments of images. The paper outlines the opportunities offered by application of the Zeroing Filter. The approach bases on the analysis of the amplitude value for the pixel that indicates potential position of the pattern image in the image under analysis and comparison of that amplitude against the average amplitude of adjacent pixels. When the differential amplitude exceeds the predefined threshold D the methods assumes that the location within the analyzed image with the desired sign of the pattern image is detected. The studies with the aim to confirm legitimacy of the assumed method were carried out for real images that had been acquired form signals of compromising emanation recorded for the special unit under test.

Keywords: Electromagnetic Infiltration; Protection of Information; Compromising Emanation

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Authors: J. Chauca; R. Doria

Abstract: Observing that nature also works as a group, a reinterpretation for field theory is given by taking the fields set {G_μ^I } as origin. Based on this assumption a whole abelian gauge theory is developed. It includes the usual abelian case and incorporates new structures as non-linearity and renormalizable mass without requiring spontaneous symmetry breaking. A next step for this systemic symmetry is to introduce an abelian internal structure. To propose an invariant action under the transformation law 〖G_μ^I〗^'=A_J^I G_μ^J+k_I ∂_μ α where A_J^I means a generic fields rotation matrix. This motivates to investigate on A_J^I possibilities, understand on its possible physicities, as consider SO(N) symmetry and introduce charged fields through SO(2) symmetry. So given such systemic gauge symmetry based on a common gauge parameter, this work builds up a systemic abelian pattern of type 〖U(1)〗_local×〖SO(2)〗_global for embracing γ, Z^0, W^+, W^- or charged particles like that.

Keywords: Whole Abelian Model; Unification; Charged Fields

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Authors: Duvan J. Mesa; Alfredo J. Constaín

Abstract: An important environmental issue for theory and applications of quality of water models in natural flows is to know precisely how to evolve the solute plume in time and space. Transport theory is by definition the branch of water sciences that most information bear due to the several physical and chemical mechanisms involved at the same time. However, currently, state-of-the-art available models are unclear when addressing this subject. This drawback probably appears by the lack of understanding of real mechanism acting in the process. In this paper, the definition of a thermodynamic function that may help to reveal those mechanisms behind this process is discussed, and in this approach discharge may be involved as internal parameter. Applying the new equations it is presented here the experimental results in a large mountain river in Colombia.

Keywords: Mass Transport in Fluids; Tracer Dynamics

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Authors: Woon Siong Gan

Abstract: A different approach using the covariant derivative, the theoretical framework of local gauge invariance is used to derive the Yang Mills field, unlike the usual way of extending the Maxwell’s equations from linear to nonlinear cases by adding a quadratic term in the vector potential. This avoids the weakness of resulting massless particles as Maxwell’s equation is meant for photons which are massless. Also since Yang Mills field is basically electromagnetic in nature and electromagnetic force is long range in nature and so it cannot explain the subatomic range of forces in the nucleus. Covariant derivative is also used to derive the Higgs field as covariant derivative is applicable to both symmetry and broken symmetry cases. A detailed mass acquisition mechanism for material particles and force particles is given for the Higgs field. This paves the way towards a unified Yang Mills Field and Higgs field. I show that the Yang Mills field is a special case of the united field when the temperature is above the critical temperature of the spontaneous symmetry breaking (SSB) when the Higgs field is zero and the masses of all particles are zero. This shows that SSB like Yang Mills theory is also an important ingredient of the Standard Model. It even has a broader implication that it can be extended to all particles in the universe unlike Yang Mills theoy is only meant for the atomic particles. Higgs boson is a product of SSB and it causes the Big Bang point to the role of SSB in the Big Bang creation of the universe and this give support to the superfluid model for the particles of the universe. I thus extend SSB to all particles of the universe and hence propose a superfluid model as the theory beyond the Standard Model to describe all the particles in the universe, including the dark energy particles and the dark matter particles. The critical temperature for SSB is equivalent to the extremely high temperature which occurs during the Big Bang. My thought has the support of the works of Tom Kibble and Kerson Huang who also propose second order phase transition and SSB to describe the early universe.

Keywords: Covariant Derivative; Yang Mills Field; Higgs Field; Unified Field; Spontaneous Symmetry Breaking; Second Order Phase Transition; Order Parameter; Mass Acquisition Mechanism; Material Particle; Force Particle; Superfluid Model; Dark Energy Particles

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Authors: K. Po?ela; J. Po?ela; V. Jucien?

Abstract: The electric field dependences of electron mobility and drift velocity in InGaAs quantum wells (QWs) of modulation doped Al<sub>x</sub>In<sub>1–x</sub>As/In<sub>y</sub>Ga<sub>1-y</sub>As and Al<sub>x</sub>Ga<sub>1–x</sub>As/In<sub>y</sub>Ga<sub>1-y</sub>As heterostructures are reviewed. It was theoretically predicted and experimentally observed that the enhancement of the low-field mobility in the AlxIn1–xAs/InyGa1-yAs QW up to 1.2×10<sup>4</sup> cm<sup>2</sup>/(V s) can be achieved by increasing the In fraction y in the QW and barriers up to y = 0.7–0.8 and by decreasing Al fraction x up to x = 0.2 in the barrier layer. The largest increase by a factor of 1.8 in the electron mobility and maximal drift velocity up to (2–4)×10<sup>7</sup> cm/s was achieved by inserting the InAs phonon wall into the InGaAs QW. The InAs phonon wall is a new type of a specific barrier transparent to electrons and reflected phonons. The created heterojunctions with high electron mobility and drift velocity were proposed and tested as basic elements for high-speed electronic devices in the 0.5–1.0 THz frequency range.

Keywords: Heterostructures; AlInAs/InGaAs; AlGaAs/InGaAs; Microwave and THz Electronics; High-Field Electron Drift Velocity in QWs; Electron–Phonon Scattering in QWs

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Authors: Najib A. Kasti

Abstract: Several publications used the finite element method to determine the band structures of periodic solids by solving the Schrödinger equation (for example, Pask et al., Sukumar et al. [1-4]). The approaches used by these publications could basically be divided into two. The first approach (Pask et al. [1-3]) expresses the wave function ψ as the product of a harmonic function and a periodic function using Bloch’s theorem. The periodic function is then discretized over the domain. In contrast, the second approach (Sukumar et al. [4]) discretizes the wave function over the domain with its nodal values being complex in this case. This paper discusses a solution procedure for determining the band structures for a class of materials starting from the approach followed by Sukumar [4]. It assumes that one can obtain the discrete Hamiltonian and overlap matrices from a conventional finite element analysis program without reverting to a special program. The application of the boundary conditions and the solution of the band structures, for the defined class of material, are performed through matrix operations of well defined steps. The final complex eigenvalue problem, to determine the band energies of the system, is then solved by conventional methods. When solving the resulting system, two representations of the overlap matrix were tested in this work, namely, the consistent and lumped representations. Each of these representations displayed a different response when compared to the exact solution. The results from the lumped and consistent formulations as well as those from a simple averaging process are discussed in this paper.

Keywords: Quantum Mechanics; Finite Element Method; Schrödinger Equation; Periodic Solids

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