Different thicknesseses of polycrystalline ZnTe films have been deposited on to glass substrates by vacuum evaporation technique under vacuum 2.1x10-5 mbar. The structural characteristics studied by X-ray diffraction (XRD) showed that the films are polycrystalline and have a cubic (zinc blende ) structure. The calculated microstructure parameters revealed that the crystallite size increases with increasing film thicknesses. The optical measurements on the deposited films were performed in different thicknesseses [ 400 , 450 and 500]nm, to determine the transmission spectrum and the absorption spectra as a function of incident wavelength. The optical absorption coefficient (α) of the films was determined from transmittance spectra in the range of wavelength (400-1100) nm. The dependence of absorption coefficient, on the photon energy showed the occurrence of a direct transition with band gap energy from 2.24eV to 1.92eV (for ZnTe films of different thicknesseses), where with high film thicknesses there are several energy levels resulting in several overlapping energy bands in the band gap of these films. The overlapping energy bands therefore tend to reduce the energy band gap, resulting in lower band gaps for thicker films.
In this research the active volume for a number of solid-state detectors of the type of high-purity germanium (HPGe) crystal was evaluated with different radii and depths using scanning method for diagonal (front) and lateral (side). It has been used for this purpose Monte-Carlo efficiency program after its development by adding a subroutine-program for its (subroutine scanning).Also a program has been written to calculate the stopping power and range for incident charged particle on the detector, in order to determine the exact sufficient energy to stop it inside the detector material. The calculations of our results of efficiency were compared with the results of published efficiency and the comparison is very good in terms of improvin
... Show MoreAbstract: Reflection optical fibre Humidity sensor is presented in this work, which is based on no core fibre prepared by splicing a segment of no core fibre (NCF) at different lengths 1-6 cm with fixed diameter 125 µm and a single mode fibre (SMF). The range of humidity inside the chamber is controlled from 30% to 90% RH at temperature ~ 30 °С. The experimental result shows that the resonant wavelength dip shift decreases linearly with an increment of RH% and the sensitivity of the sensor increased linearly with an increasing in the length of NCF. However, a high sensitivity 716.07pm/RH% is obtained at length 5cm with good stability and reputability. Furthermore, the sensor is shif
... Show MoreA spherical-statistical optical model (SOM) has been used to calculate and evaluate the neutron interaction with medium nuclei (40 ). Empirical formulae of the optical potentials parameters are predicted with minimize accuracy compared with experimental bench work data. With these optical formulae an evaluation of the shape and compound elastic scattering cross-section of interaction neutrons with 56Fe nuclei at different energy range (1-20) MeV has been calculated and compared with experimental results. Also, volume integrals for real and imaginary potential energies have been evaluated and matched with the standard ABAREX code. Good agreements with have been achieved with the available experimental data.
Through the history of art movements, abstraction has been rotating between appearance and disappearance, mounting and stillness while its performances differed between reduction and simplification on the one hand and between the use of chromatographic and linear abstraction on the other. As a result, to what is mentioned, abstraction has appeared in many different artistic forms underlying the systematicity of the plastic art history.However, according to a contemporary point of view that comes up with the scientific revolution, the art of optical deceiving (illusion) appeared to find a hybrid art form that locates between the geometricity of abstraction and the scientific, visual and psychological foundations that are linked with the i
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Abstract
An optoelectronic system for fog detection and visibility technique is presented .The idea of this research is based on the measurement of the atmospheric visibility by using an infrared beam emitter from LED diode. The optical scattering is used as a method to calculate the visibility. This method is applied at forward scattering within a foggy atmosphere, which is modern and has great importance for measuring visibility in seaports, airports, public roads and highways. In this paper we focus on the description of the system, principles of its operation and some results of field tests.
Keywords: fog sensor, visibility sensor, backscattering, forward scattering.
In the present work, silver nanoparticles were prepared. Nonlinear optical properties and
optical limiting of silver nanoparticles were investigated.Standard chemical synthesis method was used at
diffrent weight ratio(0.038, 0.058 and 0.078) of silver nitrate. Several testing were done to obtain the
characteristics of the sample. Z-Scan experiments were performed using 30 ns Q-switched Nd:YAG
laser at 1064 nm and 532 nm at different intensities. The results showed that the nonlinear refractive
index is directly proportional to the input intensities, which caused by the self-focusing of the material.
In addition, the optical limiting behavior has been studied. The results showed that the sample could be
used as an opt
In this study, polymeric coating was developed by incorporating nano graphene in the polymer blend with applications to oil storage tanks. The oil storage tanks samples were brought from the oil Pipeline Company / Doura refinery in Baghdad. The coating polymer was formed with a blend (epoxy resin and repcoat ZR). The proportion of mixing the mixture was 3:1:1 epoxy resin 21.06 gm: repcoat ZR 10.53 gm: hardener 10.53 gm. The blend/graphene was prepared using in stui-polymerization method with different weight percentage 1, 3, 5, and 7 wt % added to blend. The resulting solution was put in a glass tube on a magnetic stirrer for one hour at a temperature of 40 °C. The result of contact angle and wate
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Experimentation Multi effective and fertile grew human desire to discover new ways to express beauty in artwork .And dabble term experimentation in the performing arts and arts architecture, cinema and television in the test forms and interest in the visual effects and movements seek to establish and beauty and schools of thought in literature and art. This study aims to identify
PVC-LiF composites films with different lithium fluoride (LiF) concentrations (0, 30, 50, and 70 weight %) were prepared by using the casting method. This research deals with the investigation of dielectric properties for PVC-LiF composite films as a function of frequency and temperature in the ranges of 100 to 107 Hz and 293 - 370 K, respectively. The A.C activation energy values estimated from Arrhenius equation were 0.03820, 0.3174, 0.2009, and 0.1845 eV for the different PVC-LiF films with different LiF concentrations, respectively. It was found that the activation energy decreases by increasing LiF concentration and frequency. The exponent (s) showed a progressive increase with LiF for PVC-LiF films, while it showed
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Thermal and catalytic pyrolysis of waste plastics in an inert atmosphere has been regarded as a creative method, since pyrolysis can convert plastics waste into hydrocarbons that can be used either as fuels or as a source of chemicals.
Natural Iraqi kaolin clay was used to synthesis the NaX nano- zeolite by hydrothermal conditions with average particle size equal to 77.63nm.Thermal decomposition kinetics of high-density polyethylene (HDPE) in the absence and presence of catalysts nano NaX Zeolite was investigated. Thermal and catalytic degradation of HDPE was performed using a thermogravimetric analyzer in nitrogen atmosphere under non-isothermal conditions 4, 7 and 10 °C/min heating rates were employed in thermogravimetric anal
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