In this paper, a theoretical study to the effect of journal misalignment on the static characteristics of oil filled porous journal bearing when lubricated with couple stress fluid has been carried out.
The analytical model used through this work is for a bearing with isotropic permeability. Considering isotropic permeability the Reynolds' equation for the oil film is modified to include a so – called filter term and the effect of fluid coupled stress. The pressure equation for the porous medium is obtained from Darcy's law and continuity equation. The equation which was used to evaluate the oil film thickness was modified to include the effect of possible misalignment in longitudinal and transverse directions. The governing eq
... Show MoreIn this paper, a theoretical study of the energy spectra and the heat capacity of one electron quantum dot with Gaussian Confinement in an external magnetic field are presented. Using the exact diagonalization technique, the Hamiltonian of the Gaussian Quantum Dot (GQD) including the electron spin is solved. All the elements in the energy matrix are found in closed form. The eigenenergies of the electron were displayed as a function of magnetic field, Gaussian confinement potential depth and quantum dot size. Explanations to the behavior of the quantum dot heat capacity curve, as a function of external applied magnetic field and temperature, are presented.
We report a method of converting non-conductive plastic surfaces into conductive by plating either copper electroless or copper electroplating -carbon black containing bending Agent onto Perspex plastics . Various approaches have been studied in order to comparing properties of the plated copper for two methods such as scanning electron microscopy (SEM),thickness, roughness, porosity, tensile Strength and elongation. The results show that the surface of electroplating was uniform, compact, and continuous and it had an obvious metallic sheen, while the surface of plated copper for electroless for it had many pores. Also observed that the coating was composed of small cells. Thes
... Show MoreMagnetic Abrasive Finishing (MAF) is an advanced finishing method, which improves the quality of surfaces and performance of the products. The finishing technology for flat surfaces by MAF method is very economical in manufacturing fields an electromagnetic inductor was designed and manufactured for flat surface finishing formed in vertical milling machine. Magnetic abrasive powder was also produced under controlled condition. There are various parameters, such as the coil current, working gap, the volume of powder portion and feed rate, that are known to have a large impact on surface quality. This paper describes how Taguchi design of experiments is applied to find out important parameters influencing the surface quality generated during
... Show MoreThe effect of different magnetic Jiel ds on the Nal(Tl) scintillation detector of (3"x3") and (1.5"x1.5") sizes was studies, using the radioactive source Cs-137.
Two type:; of coils (A,B) were used to produce the magnetic fields. The coil "A" is cylindrical of "9cm" diameter and "9cm" length , and of
2500 turns.
The measurements were taken in two positions ;the first when the crystal inside the coil ,and the second, the PMT inside the coil . The range of the magnetic field was (0.35,0.61,0.84,1.1 1,1.37,1.62,1.87 and
2.12) mT.
The coil "D" consists of two circular and parallel coils of "12 em" distance between them and of "18.5 em" diameter of each other and of "125" turns. rive &
... Show MoreThis study aimed to determine the effect of varicocelectomy on sperm parameters, oxidant- antioxidant status and chromatin maturity percent. The current study has been conducted on 154 infertile patients complaining from varicocele and varicocelomized men in addition to 25 fertile men as control. The results revealed significant decrease (P<0.05) in sperm concentration, progressive motile sperm percent, normal sperm morphology percent, GSH, SOD1, CAT levels and chromatin maturity percent and significant increase (P<0.05) in MDA and ROS concentrations in infertile patients with varicocele when compared to fertile men. The results revealed improvement (P<0.05) of sperm parameters quality, GSH, SOD1, CAT, MDA, ROS concentration and chromatin m
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The research aims to build an integrated frame of knowledge for the basic research topics, represented by (assimilation of knowledge, strategic clarity) and their basic variables, by examining the most important scientific propositions on these topics in administrative thought, and framing the knowledge contained in them, in a serious attempt to provide appropriate answers to questions The research dilemma, and the research was applied in the Iraqi Airways Company, whose number is (1200) employees, and the descriptive and analytical approach was adopted in conducting the research. A valid form for statistical analysis, i.e., with a retrieval rate of (92%). The two researchers used the (SPSS & AMOS) program for
... Show MoreThe research aims to find ways to minimize the use of quantities of chemical fertilizers in agriculture in order to get to an environment that is free of contaminants. Magnetized water technology used in the experience of planting seeds of tomatoes Thomson type to obtain a higher efficiency to absorb fertilizer NRK in the protected environment of the period from February to June. Magnetized water system used locally made levels Gaues (4800,2500,1500) concentrations of 50 to 100% for each level and the rate of (4) replicates, and results indicated that the severity of the magnet (4800 Gaues) and a concentration of 50% gave the highest percentage of tomato fruit size and intensity ( 1500 Gaues) and a concentration of 100% did not give any inc
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