Dielectric

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    (6) The remaining contribution to the net Coulomb energy comes from the self-interaction of each charge with its own image, which is the so-called “dielectric solvation energy” ()()aaaaHRaaarVrrdrVˆ02ρ∫+=. (7) In above expressions, ()()2rraaℜ=ρ is the electron or hole density, and a = e, h; ()herrW,ˆ is a spherically symmetric component of the point charges direct Coulomb interaction operator, is a spherically symmetric component of the polarization energy operator, and ( herrU,ˆ ()rVˆ is the dielectric solvation energy operator. To obtain the explicit form of these operators we solve analytically the Poisson equation for a potential due to a point charge in the core/shell structure with the standard boundary conditions that account for discontinuity of the dielectric constant at hetero-interfaces.3 As a result, we obtain the following solutions: 3 ()()()()()()[](hecescheheherrqRrRrrRrRrrW,max2,ˆ2εεεθθθθ−+−+−−−= (8) ()()()()()(HRqRqrRrRrrUsesecscehehe+−−−−−−=εεεεεεθθ11,ˆ22 (9) where cε , sε and eε are the dielectric constants of the core, the shell, and the environment, respectively, and ()xθ is the Heaviside step function. The expression for the dielectric solvation energy is more complex and can be represented as a sum of two…

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    1.1 Dielectric Materials Dielectric materials are insulating materials that exhibit the property of electrical polarization. Dielectric materials support charge by acquiring a polarisation in an electric field. 1.1.1 Electric susceptibility and permittivity When a capacitor with capacitance C0 is filled with a dielectric material, its charge storage capacity (capacitance) increases to a value of C. Than susceptibility (χ^') of the dielectric materials is given by χ^'= (C-C_0)/C Dielectric…

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    Electrical Properties AC Conductivity, Ac Resistivity, Dielectric loss, and Dielectric constant are electrical properties and measured as a function of frequency. AC Conductivity and Resistivity AC resistance (ρac) was recorded by LCR meter model 4275 in the frequency range 1MHz to 3GHz. AC conductivity was determined by using the value of Ac resistance. As we know, Ac Conductivity is reciprocal of Ac resistance can be calculated by the relation; ac =1/ρac (6) The variation of AC…

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    The dielectric loss factor was the most influenstic parameter in this microwave spectrum. The loss factor values increased as a function of frequency and slight modification in spectrum on changing the solute concentration. The ε˝ values obtained in our experiments are almost similar to our earlier work[43]. Above 8GHz the frequency dispersion spectrum of ε΄& ε˝ were superimposed with each other. The spacing between the dielectric values in dispersion spectrum could be attributed to…

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    On the basis ofBased on the p-type pentacene and n-type N,N′’-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13), low-voltage organic field-effect transistors (OFETs) and inverters using hafnium (Hf)-based dielectrics were produced and characterized. All Based on the p-type pentacene and n-type N,N′-ditridecylperylene-3,4,9,10-tetracarboxylic diimide (PTCDI-C13), low-voltage organic field-effect transistors (OFETs) and inverters using hafnium (Hf)-based dielectrics were produced…

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    Polarization In Antenna

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    any one of the dimension. The other dimensions of the signal will be nullified. This type is generally used in the antennas where we are dealing with the transmission and reception of horizontal and vertical antennas. In this, for example we want to receive horizontal signal, then we have dielectrics in the antenna places horizontal when these dielectrics come in contact with the horizontal wave they get polarized and we get the signal and when one the same antenna we get the vertical signal…

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    A graph is plotted between dielectric constant (εr) versus log frequency for different temperatures 30 0C, 60 0C, 90 0C and 120 0C for Tb3+: SA single crystals. From the Fig12(a) we can conclude that dielectric constant is high at low frequencies which is because of space charge polarization [61] which depends on purity and perfection of the sample. The maximum values of dielectric constant is 6.9, 6.8 for SR and SEST grown Tb3+: SA single crystals respectively, minimum values are 1.4, 1.2 for…

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    that the D.C electrical conductivity increased with increasing the alumina concentrations and temperature. Also the activation energy change with increasing of additional alumina. The dielectric constant, dielectric loss, A.C electrical conductivity are changed with change the concentration of the filler and frequency of applied electrical field. Keywords: Composites, poly-methyl methacrylate, Electrical Properties. Introduction In order to fulfill the requirements of polymer industry many…

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    bandwidth response levels of The Microstrip Patch Antenna are unsatisfactory, the antenna is widely implemented for various applications with high gain and large bandwidth. Fig. 1. A Microstrip Patch Antenna [1] II. Design of the antenna The Microstrip Patch Antenna consists of a radiating metallic patch on top of a dielectric substrate, which has a ground plan on the other side as shown in Fig. 1. The following equations were used to design of the Antenna: Where, W = Width of the patch C…

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    Antireflection coatings usually have single or multiple layered dielectric thin films deposited at the top of crystalline silicon substrate using various deposition techniques such as Spray Pyrolysis, Plasma Enhanced Chemical Vapor Deposition, Sputtering and many other similar deposition techniques [16, 18]. Various dielectric materials such as SiNx, SiO2, TiO2, ZnS, ZrO2, AlO¬3¬ and HfO¬2 ¬ can be used as antireflection coating in solar cells. The most widely used ARC is Silicon Nitride (SiNx)…

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