The main aim of the present paper is to study the electric breakdown in a uniform electric discharge system. The system consists of two spheres separated by a dielectric. The dielectric is dry air. Certain boundary conditions are taken into consideration as applied voltage, pressure, and domain. The formation of discharge types as Townsend and streamer under different distance gaps (1, 0.9,0.8, 0.6, 0.4, 0.2, 0.1) mm was sudied. The temperature effect on the breakdown voltages for the discharge process is also included. Seven different temperature steps are chosen in the study. Comsol Multiphysics software is used for the simulation model as a plasma model. Results show that as the gap distance increases the breakdown voltage increases for each of the discharges. For maximum electric field, as the distance increases the field also increases. For gap distance, the temperature effects are more apparent at the higher values of the pressure. The maximum electric field increases as the voltage increases with the temperature.
In this work, seven soil samples were brought brought to study and analyses the element concentrations from different southern regions of Iraq using laser-induced breakdown spectroscopy (LIBS) technique. It has been documented as an atomic emission spectroscopy (AES) technique. Laser-induced plasma utilized to analyze elements in materials (gases, liquids, and solids). In order to analyze elements in materials (gases, liquids, and solid). The Nd: YAG laser excitation source at 1064 nm with pulse width 9 ns is used to generate power density of 5.5 x 1012 MW/mm2, with optical spectrum in the range 320-740 nm. From this investigation, the soil sample analysis of the southern cities of Iraqi, it is concluded that the rich soil element of P, Si,
... Show MoreIn the present work, the effect of the cylindrical configurations of the sputtering device electrodes on the plasma parameters (Debye length, electron temperature, electron density, plasma frequency) is studied. Also, the effect of the argon gas pressure on the discharge properties is examined with gas pressures of (0.08, 0.2, 0.4 and 0.6) Torr. The properties of the plasma are diagnosed by optical emission spectrometry. The spectroscopic method is adopted for examining the atomic spectra of argon emission. The electron temperature is determined by the Boltzmann method. While, the Stark-widening method was employed for calculating the electron number density. The voltage against current curves of the cylindrical sprayer disc
... Show MoreRapid breakdown anodization (RBA) process was used to fabricate TiO2 sensor to measure pressure and humidity and sense gases at room temperature. This chemical process transformed Ti to its oxide (TiO2) as a powder with amorphous phase as X ray diffraction (XRD) technique confirmed. This oxide consisted from semi spherical nanoparticles and titania nanotubes (TNTs) as Scanning electron microscope (SEM) technique showed. TiO2 powder was deposited on Ti substrates by using electrophoretic deposition (EPD) method. Average pressure sensitivity was 0.34 MΩ/bar and hysteresis area was 1.4 MΩ .bar. Resistance of TiO2 decreased exponentially with the increasing of relative
... Show MoreThe significant shortage of usable water resources necessitated the creation of safe and non-polluting ways to sterilize water and rehabilitate it for use. The aim of the present study was to examine the ability of using a gliding arc discharge to inactivate bacteria in water. Three types of Bacteria satisfactory were used to pollute water which are Escherichia coli (Gram-negative), Staphylococcus aurous (Gram-positive) and salmonella (Gram-negative). A DC power supply 12V at 100 Hz frequency was employed to produce plasma. pH of water is measured gradually during the plasma treatment process. Contaminated water treated by gliding arc discharge at steadying the gas flow rate (1.5 l/mi
In this work, the Al-Mg alloys plasma plume that produced under vacuum (10-1 torr) by Nd:Yag Laser was studied. the plasma spectra were analyzed by comparing the atomic lines of Al and Mg lines with standard lines. The effect of laser energies on spectral lines produced by laser ablation were investigated using optical
spectroscopy .several plasma characteristics like electron temperature, electron density, Debye’s length, plasma frequency and number of particles in the ‘‘Debye’s Sphere’’ were calculated in vacuum .The results show the electron temperature and electron density increase in magnesium, aluminum and magnesium :aluminum alloy
targets . It was found that the lines intensities at
Simplifying formulas that are used for calculations and design are the aim of researchers. For present work, the approach to distinguish the flow under sluice gate was conducted in a laboratory. The extensive experimental program was done to collect fifty-four data points for both free and submerged flow conditions. The data included different discharges, gate openings, flow depths at upstream as well as the flow depths represent a tail water and at a contracted section for downstream. The collected data are analyzed according to a problematic that may encounter in the field, to present a more straightforward (but with acceptable accurate) practical features equations and charts. Based on the proposed formulas, five meth
... Show MorePre-breakdown phenomenon was investigated within the two, non-mixed dielectric liquids; transformation oil and cresol. Finite element technique was used to follow the initiation and growth of plasma channels (streamer discharge) within pin-plane configuration. That was done for different spacing between the pin-electrode and the liquid-liquid interface. Streamer growth model assumed that, the streamer initiation occurs at the region of the highest value of electric field. Our study shows that the streamer initiates at the tip of the pin and growths toward the other electrode. The study shows, too, that the streamer path controlled by the difference of permittivity of the two liquids and spacing distance of the liquid-liquid interface fro
... Show MoreThis paper presents experimentally a new configuration of shear connector for Steel-Concrete-Steel (SCS) sandwich beams that is derived from truss configuration. It consists of vertical and inclined shear connectors welded together and to cover steel plates infilled with concrete. Nine simply supported SCS beams were tested until the failure under a concentrated central load (three- point bending). The beams were similar in length (1100mm), width (100mm), and the top plate thickness (4mm). The test parameters were; beam thickness (150, 200, 250, and 300mm), the bottom plate thickness (4, and 6mm), the diameter of the shear connectors (10, 12, and 16mm), and the connector spacing (100, 200, and 250mm). The test results sh
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