This work is an experimental study about the effects of gas pressure and magnetic field on plasma characteristics produced in an internal hollow electrodes discharge (HED) system. The results show that the breakdown voltage values increase with increasing the working pressure (especially with the presence of a magnetic field). The breakdown voltage depends on the p.d. product, where p is the gas pressure and d is the distance between the electrodes. While the values of current discharge decrease with the increase of the working pressure. The temperature of electron and the number density of electron are calculated from the Boltzmann method and the broadening of Stark, respectively. The results showed that the electron number density ( ) and plasma frequency ( ) increase with increasing the gas pressure, especially with the presence of a magnetic field, i.e. the plasma is more stable with the presence of magnetic field. While the electron temperature ( ) and Debye length ( ) decrease with increasing the gas pressure.
In this Research, (In2O3: CdO) films were prepared using pulsed laser deposition (PLD) method on glass substrate at room temperature deposited at laser influence 500mJ/cm2with different shoots N= (200,300,400,500and600). the structural, and the optical properties and the films are studied with different annealing temperatures (523and 623) K. Optical measurements and the films were analyzed by UV-VIS absorption spectra. The structural properties of samples were investigated by x-ray diffraction patterns of the films and show that the films and polycrystalline Structure with all shoots. Transmittance spectrum found is equal to 93.17%, refractive index range is 1.635 and energy gap range is 2.75-3.15ev.
Abstract
Experimental work from Magnetic Abrasive Finishing (MAF) tests was carried out design parameters (amplitude, and number of cycle which are formed the shape of electromagnetic pole), and technological parameters (current, cutting speed, working gap, and finishing time) all have an influence on the mechanical properties of the surface layer in MAF process. This research has made to study the effect of design and technological parameters on the surface roughness (Ra), micro hardness (Hv) and material removal (MR) in working zone. A set of experimental tests has been planned using response surface methodology according to Taguchi matrix (36) with three levels and six factors
... Show MoreIn this paper, a numerical analysis was carried out using finite element method to analyse the mechanisms for streamer discharges. The hydrodynamic model was used with three charge carriers equations (positive ion, negative ion and electron) coupled with Poisson equation to simulate the dynamic of streamer discharge formation and propagation. The model was tested within a 2D axisymmetric tip-plate electrodes configuration using the transformer oil as the dielectric liquid. The distance between the electrodes was fixed at 1 mm and the applied voltage was 130 kV at 46 ns rising time. Simulation results showed that the time has a clear effect on the streamer propagation along the symmetry axis. In addition, it was observed that t
... Show MoreIn this present paper , a special model was built to govern the equations of two dimensional peristaltic transport to nanofluid flow of a heat source in a tapered considered in an asymmetric channel. The equations of dimensionless temperature concentration are analytical solve under assumption slow Reynolds number and long wave length. Furthermore, the results that receive by expressing the maximum pressure rise communicates increased in case of non-Newtonian fluid when equated with Newtonian fluid. Finally, MATHEMATICA 11 program has been used to solve such system after obtaining the initial conditions. Most of the results of drawing for many are obtained via above program .
The professional skepticism is one of the fundamental concepts necessary for practicing the audit profession, without which the auditor can not reach a reasonable assurance as to the correctness of the evidence and the information obtained by the auditing department. The auditor's possession of the characteristics of professional skepticism and his practice of professional skepticism during the audit process lead to an increase The quality of audit and thus raise the confidence of the financial community in the audit profession again after the exposure of several crises led to the loss of financial society confidence in the audit profession.
The aim of the study is to measure the impact of professional sk
... Show MoreIn this paper the variable structure control theory is utilized to derive a discontinuous controller to the magnetic levitation system. The magnetic levitation system model is considered uncertain, which subjected to the uncertainty in system parameters, also it is open-loop unstable and strongly nonlinear. The proposed variable structure control to magnetic levitation system is proved, and the area of attraction is determined. Additionally, the chattering, which induced due to the discontinuity in control law, is attenuated by using a non-smooth approximate. With this approximation the resulted controller is a continuous variable structure controller with a determined steady state error according to the selected control
... Show MoreCold atmospheric plasma (CAP) is used widely in medical and biological fields because of non-thermal effected. Direct application of plasma is preferred in medical functions, so, direct application of cold plasma has obtained by the floating electrode dielectric barrier discharge (FE-DBD) system. The purpose of this paper to review the effect of (CAP) on the reproductive hormones (testosterone, LH, E2, progesterone, for male rats. The study appeared that no significant effect on E2 and progesterone hormone for all time of exposure, besides this significant difference in LH hormone (P<0.05) at 15 sec, (P<0.0001) at 30, 90 sec and (P<0.001) at 60 sec of exposure to plasma. Added to that significant difference (P<0.01) at 15, 30, 60 sec and no
... Show MoreThis study evaluates the performance of magnetic abrasive finishing (MAF) of aluminum alloy in terms of achieving materials removal (MR). A vertical milling machine is used to perform the finishing process using a developed MAF unit that consists of an inductor made out of a 150 mm long and 20 mm diameter iron core wound with 1500 turns and 0.5 mm copper wire. The commutator and magnetic pole are attached at the top and bottom of the inductor, respectively. The required current is supplied using a DC power supply. The South Pole workpiece is a 100×50×3 mm3 plate of AA 1100 aluminum alloy, whereas the magnetic pole represented the North Pole. Pole rotational speed, applied current, and abrasive finishing time was selected as
... Show MoreThis work aimed to use effective, low-cost, available, and natural adsorbents like eggshells for removal of hazardous organic dye result from widely number of industries and study the influence of different eggshell particle size (75, 150) Mm. The adsorbent was characterized by SEM, EDX, BET and FTIR . The initial pH of dye solutions varying from 4 to 10 , the initial concentrations of methyl violet (MV) 2B range (20-80) mg/L, dosage range (0.5-10) g, contact time (30-180) min, and particles size of the adsorbent (75, 150) Mm were selected to be studied. Two adsorption isotherms models have been used to fit the experimental data. Langmuir and Freunlich models were found to more represent the experiments with high
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