A number of glow discharge experiments has been carried out in a relatively large-volume metallic vacuum chamber containing argon at low pressure and immersed in an inhomogeneous magnetic field generated by a solenoidal coil capable of delivering 2100G. Two Paschen curves demonstrating the dependence of the discharge voltage on sparking parameter Pd and magnetic field strength B were deduced. A graphical correlation showing the behaviour of the voltage difference from the two curves on the ratio B/Pd was constructed. Investigations showed a reduction in the nominal impedance of the discharge device of nearly 20% when B reaches a value of 525G. Plasma confinement regions were found around the internal surface of the chamber at the entrance of the electrodes which may be attributed to pressure gradient by JxB effects as well as ExB drifts.
Titanium alloy (Ti-6Al-4V) samples were nitrided in low pressure (1.3, 3 mbar) dc-glow discharge plasmas of nitrogen. The treating time was 5, 10 and 15 hour and the temperatures range of the samples during the nitriding process was close to 800oC. The obtained microstructures of the nitride layers were studied by x-ray diffraction and optical microscopy. The ε –Ti2N, ζ-Ti3N3-x and η-Ti3N2-x.phases were formed and addition to the solid solution of nitrogen in titanium, α (Ti,N). Micro hardness measurements exhibit an increment for the Ti-alloy specimens which nitrided at 800oC for 10 and 15h.Corrosion measurements were obtained for the Ti-6Al-4V alloy in Ringer solution after plasma nitriding. The clear improving in the corrosion r
... Show MoreWe have studied Bayesian method in this paper by using the modified exponential growth model, where this model is more using to represent the growth phenomena. We focus on three of prior functions (Informative, Natural Conjugate, and the function that depends on previous experiments) to use it in the Bayesian method. Where almost of observations for the growth phenomena are depended on one another, which in turn leads to a correlation between those observations, which calls to treat such this problem, called Autocorrelation, and to verified this has been used Bayesian method.
The goal of this study is to knowledge the effect of Autocorrelation on the estimation by using Bayesian method. F
... Show MoreDC planar sputtering system is characterized by varying discharge potential of (250-2000 volt) and Argon gas pressures of (3.5×10-2 – 1.5) mbar. The breakdown voltage for silver electrode was studied with a uniform electric field at different discharge distances, as well as plasma parameters. The breakdown voltage is a product of the Argon gas pressure inside the chamber and gab distance between the electrodes, represent as Paschen curve. The Current-voltage characteristics curves indicate that the electrical discharge plasma is working in the abnormal glow region. Plasma parameters were found from the current-voltage characteristics of a single probe positioned at the inter-cathode space. Typical values of the electron temperature an
... Show MoreThe aim of the study was to investigate the effect of magnetized water on the histological structure of heart, lung and spleen. For this purpose, twenty five albino rats were divided into five equal groups, the first group was considered as control group. The other groups were given magnetized water with intensity of 250, 750, 1000, 1500 gause every day for 30 days. Then the animals were sacrificed and the histological change on heart, lung and spleen was studied. Histopathology of heart in rats treated with magnetic water with intensity of 250, 750, 1000, 1500 gause showed no clear pathological lesion. Lung section of rats treated with 250 gause of magnetic water showed no pathological lesion, while lung section belongs to rats group given
... Show Morea laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the rod that appears for Au NPs, in addition to that, TEM has been an indication of the fact that syn
... Show MoreThe current study aimed the syntheses and characterizations of Gold nanoparticles (Au NPs) using a laser ablation Q-switched Nd: YAG laser with a wave-length of 355 nm at a variety of laser pulse energies (E) and deposited on porous silicon (PS). Optical emission spectrometer was used to diagnosed medium air to study gold plasma characteristics and prepared Au nanoparticles. The laser pulse energy influence has been studied on the plasma characteristics in air. The data showed the emergence of the ionic (Au II) spectral emission lines in the gold plasma emission spectrum. XRD has been utilized to examine structural characteristics. Moreover, AFM results 37.2 nm as the mean value of the diameter that is coordinated in a shape similar to the
... Show MoreNon-thermal atmospheric pressure plasma has emerged as a
new promising tool in medicine and biology. In this work, A DBD
system was built as a source of atmospheric pressure non-thermal
Plasma suitable for clinical and biological applications. E. coli and
staphylococcus spp bacteria were exposed to the DBD plasma for a
period of time as inactivation (sterilization) process. A series of
experiments were achieved under different operating conditions. The
results showed that the inactivation, of the two kinds of bacteria, was
affected (increasing or decreasing) according to operation conditions
because they affects, as expected, the produced plasma properties
according to those conditions.
A theoretical model is developed to determine time evolution of temperature at the surface of an opaque target placed in air for cases characterized by the formation of laser supported absorption waves (LSAW) plasmas. The model takes into account both plasma dynamics and time variation of incident laser pulse (i.e. pulse shape or profile).Shock tube relations were employed in formulating plasma dynamics over target surface. Gaussian function was chosen in formulating the pulse profile in the present modeling
Objective: Rheumatoid arthritis (RA) patients have increased morbidity and mortality from premature cardiovascular (CV) disease (CVD). Framingham risk score (FRS) is a simplified coronary prediction tool developed to enable clinicians to assess the risk of a cardiovascular event and to identify candidate patients for risk factors modifications worldwide. The predictive ability of the FRS varies between populations, ethnic groups, and socio-economic status. The aim of this study is to find if there is any correlation between the Framingham risk score and the inflammatory and biochemical parameters used to measure disease activity and functional ability in Iraqi patients with active RA.
A theoretical investigation is carried out to study the effect of a pencil electron beam propagating inside the plasma region determining the hydrodynamic densities distribution with the aid of numerical analysis finite deference method (FDM).The plasma is generated and trapped by annular electron beams of fixed electron density 1x1014 m-3. The result of the study shows that the hydrodynamic density behaves as the increase in pencil electron beam. The hydrodynamic density ratio goes to more than double as the increase in pencil electron beam density to 1x1018 m-3.