Pre-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 from the tip of the pin electrode. This type of studies is very important to give a good approximation for the high voltage equipments designing
This study shows the effects of copper material electrode, applied voltage, and different pressure values on electrical discharge plasma. The purpose of the work is the application of the spectral analysis method to obtain accurate results of nitrogen plasma parameters. By using the optical emission spectroscopy (OES), many N2 molecular spectra peaks appeared in the range from 300 to 480 nm. Also, some additional peaks were recorded, corresponding to atomic and ionic lines for nitrogen, target material, and hydrogen, in all samples. The electron density (ne) was calculated from the measurement of Stark broadening effect, which was found to decrease with increasing pressure from 0.1 mba
... Show MoreIn this study, a system of nonthermal plasma that was operated under atmospheric pressure and was powered by argon gas was employed. The particular plasma properties are affected by changes in the Ar gas flow ranges from 0.5 to 2.5 l/min, product by stream of the plasma jet that is utilized. By using the aforementioned method generated from AC and DC. After placing Ar gas as the cathode, which represents the negative pole, flows toward the anode, which is represented by a tiny metal plate of Zn measuring 6 × 1 cm2 in size, with a submerged part of 4 cm2 long, with both types of current employed having a high voltage of 13.5 kV and the frequency of AC was 30 kHz, we measured these variable parameters. It has been shown that when argon f
... Show MoreThis paper considers and proposes new estimators that depend on the sample and on prior information in the case that they either are equally or are not equally important in the model. The prior information is described as linear stochastic restrictions. We study the properties and the performances of these estimators compared to other common estimators using the mean squared error as a criterion for the goodness of fit. A numerical example and a simulation study are proposed to explain the performance of the estimators.
The linear instability and nonlinear stability analyses are performed for the model of bidispersive local thermal non-equilibrium flow. The effect of local thermal non-equilibrium on the onset of convection in a bidispersive porous medium of Darcy type is investigated. The temperatures in the macropores and micropores are allowed to be different. The effects of various interaction parameters on the stability of the system are discussed. In particular, the effects of the porosity modified conductivity ratio parameters, and , with the int
... Show MoreNon-thermal plasma(Dielectric barrier discharge) has many uses including living tissue sterilization, inactivation of the bacteria, excimer formation, angiogenesis, and surface treatment. This research aim is to use cold plasma as a tool to search the effect of the dielectric barrier discharge system at room temperature on human sperm motility and DNA integrity. This work was performed on 60 human semen samples suffering from low motility; each sample was prepared by centrifugation method, then each semen sample was divided into two sections, the first section is before significant exposure to the plasma system (DBD) and the second section is after treatment with the DBD system at ambient temperature. Before and after exposure to non-the
... Show MoreBiofilm formation represents one of the biggest problems facing scientists because of this phenomenon linkage with virulence of bacteria and other clinical environmental problems. In the present study, two clinical isolates,
Escherichia coli, and Staphylococcus aureus were exposed to the non thermal plasma for different intervals of time (1, 2, 4, 8, and 16 min). The biofilm was measured post exposing. It was found that 2 min. exposing to non-thermal plasma reduced the biofilm formation by both clinical isolates significantly. It can be concluded that the ability of S. aureus to form biofilm higher than E. coli and exposing for 2 min to non-thermal plasma sufficient to reduce the biofilm formati
In the current study, the emission spectra generated from clove were measured under normal atmospheric pressure with different laser energies. Clove is used as a source of essential oil in herbal medicine, in particular as a dynamic analgesic oil in dental and other diseases. For aromatherapy, Antiseptic, antiviral, and antimicrobial agents are also packaged with cloves. Compounds that reduce inflammation tend to battle sore throats, cold, and cough as they display so many advantages. The measured spectrum reveals distinctive lines of clove’s chemical elements. X-ray fluorescent (XRF) and atomic absorption spectrometry (AAS) were used to measure the spectrum generated or absorbed by detecting the presence of va
... Show MoreThe calculation of the charge on an isolated dust grain immersed in plasma with different grain sizes is a challenging one, especially under moderately high plasma temperature when secondary electron emission significant. The discrete charging model is used to calculate the charges of dust grain in dusty plasma. In this model, we included the effect of grain size dependence on secondary electron emission. The results show that the secondary electron emission from the glass dust grains due to energetic electron (40eV) can lead to the small grain to be slightly more positive than the large grain. Under these conditions, the smaller and larger grains would be attracted rather than repelled, which possibly lead to enhanced coagulation rates.
... Show MoreNanoparticles generation by laser ablation of a solid target in a liquid environment is an easy method. Cadmium Telluride (CdTe) colloidal nanoparticles have been synthesized by laser ablation Nd:YAG with wavelengths of 1064nm and double frequency at 532 nm, number of pulses 50 pulses, with pulse energy= 620mJ, 700mJ of a solid target CdTe is immersed in double distilled deionized water (DDIW) and in methanol liquid. Influences of the laser energy and different solutions on the formation and optical characterization of the CdTe nanoparticles have been studied using atomic force microscope (AFM) and the UV-Vis absorption. As a results, it leads to the absorbance in UV-Vis spectra of samples prepared in water at laser wavelength of 532nm i
... Show MoreBackground: In the present study used device jet plasma needle with atmospheric pressure which generates non thermal plasma jet to measure treatment potent with plasma against pathogenic bacteria founded in UTI was inactivated with plasma at 10 sec,
Objective:. This work included the application of the plasma produced from the system in the field of bacterial sterilization , where sample of Gram- negative bacteria (Escherichia coli) were exposed to intervals (1-10)second . Midstream Urine samples swabs were obtained from patients with urinary tract infections.
Type of the study: Cross -sectional study.
Methods: The work were used i
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