A high Tc superconductor with a nominal composition
(Bi1-xPbx)2(Sr1-yBay)2Ca2Cu3O10+δ for (0 £ x £ 0.5) and (0 £ y £ 0.5) was prepared by
a solid state reaction method. The effect of the substitution of Pb for Bi and Ba for Sr and
quenching temperature on the superconductivity has been investigated to obtain the
optimum conditions for the formation and stabilization of the high Tc phase (2223).
The results showed that the optimum sintering temperature for the pure composition is
equal to 875°C and the sintering time is equal to 240h with heating and cooling rate of
60°C/h . Our results indicated that a small amount of (Ba = 0.1) could raise the transition
temperature (Tc), but enhancing Ba to 0.4 has raised
This paper is focused on studying the effect of cutting parameters (spindle speed, feed and depth of cut) on the response (temperature and tool life) during turning process. The inserts used in this study are carbide inserts coated with TiAlN (Titanum, Aluminium and Nitride) for machining a shaft of stainless steel 316L. Finite difference method was used to find the temperature distribution. The experimental results were done using infrared camera while the simulation process was performed using Matlab software package. The results showed that the maximum difference between the experimental and simulation results was equal to 19.3 , so, a good agreement between the experimental and simulation results was achieved. Tool life w
... Show MoreThe present investigation was conducted to evaluate the effect of the crude extracts mixture of three plants (Tribulus terrestris, Phoenix dactylifera and Nasturtium officinale) on semen quality,sex hormones and reproductive performance of mature male mice. A group of 25 male mice given 150mg/kg/day of the powder of the plants mixture with the food for four weeks and another three groups of 25 animals each given intraperitoneal injection from each of the aqueous and ethanolic extracts with a doses 75, 150, and 300mg/kg/day for two weeks. A remarkable increase in sperm concentration and motility with a decreased abnormal morphology was obtained in the experimental groups. A significant increase in hormones level were recognized in most grou
... Show MoreBackground: Wound healing is a complex dynamical interaction between various cell types, the extracellular matrix, cytokines, and growth factors. osteoponetin is a substance that acts as an anti-inflammatory. Aims of study: The study was designed to identify the role of local exogenous applications of osteopontin on wound healing (in cheek skin). Materials and methods: Thirty adult male albino rats weighting an average of (250-300gm) used in this study, incisional wounds were made in the skin of the cheek of rat and they were divided into the following groups: A-Control group: 15 rats treated with 1µ l of normal saline B-Experimental groups: 15 rats treated with topical application of 1µl osteopontin. The scarification of animals we
... Show MoreThe corrosion behavior of carbon steel at different Temperatures and in water containing different sodium chloride
concentrations under 3 bar pressure has been investigated using weight loss method . The carbon steel specimens were
immersed in water containing (100,400,700,1000PPM) of NaCl solution and under temperature was increased from
(90-120ºC) under pressures of 3 bar. The results of this investigation indicated that corrosion rate increased with NaCl
concentrations and Temperature.
CdSe quantum dots possess a tuning energy gap which can control gap values according to the size of the quantum dots, this is made the material able to absorb the wavelengths within visible light. A simple model is provided for the absorption coefficient, optical properties, and optical constants for CdSe quantum dots from the size 10nm to 1nm with the range of visible region between (300-730) nm at room temperature. It turns out that there is an absorption threshold for each wavelength, CdSe quantum dots begin to absorb the visible spectrum of 1.4 nm at room temperature for a wavelength of 300 nm. It has been noted that; when the wavelength is increased, the absorption threshold also increases. This applies to the optical propertie
... Show MoreBackground: Direct measurement of intracellular magnesium using erythrocytes has been suggested as a sensitive indicator for the estimation of body magnesium store. Marked depletion in plasma and erythrocyte magnesium levels was particularly evident in diabetic patients with advanced retinopathy and poor diabetic control. While insulin has been shown to stimulate erythrocyte magnesium uptake, hyperglycemia per se suppressed intracellular magnesium in normal human red cells.
Aim of the study: To investigate the erythrocyte magnesium level in Iraqi type I and II diabetic patients, with specific emphasis on the effect of both, metabolic control and the type of antidiabetic treatments.
Methods: Sixty two diabetic patients (7 with type
Mechanical and thermal properties of composites, consisted of unsaturated polyester resin, reinforced by different kinds of natural materials (Orange peels and Date seeds) and industrial materials (carbon and silica) with particle size 98 µm were studied. Various weight ratios, 5, 10, and 15 wt. % of natural and industrial materials have been infused into polyester. Tensile, three-point bending and thermal conductivity tests were conducted for the unfilled polyester, natural and industrial composite to identify the weight ratio effect on the properties of materials. The results indicated that when the weight ratio for polyester with date seeds increased from 10% to 15%, the maximum Young’s modulus decreased by 54%. When the weight rat
... Show MoreAn experimental study was conducted to evaluate the effect of AL-coholic extract alkaloid of Cordia myxa leafs in fourth larval stage of lesser grain borer Rhyzopertha dominica. Using alkaline extracts of 8%, the study has been shown clear effect increased in mortality rate for fourth larval stage 93.3% and degressed to 66.6% at 4% concentrate to 13.3% with control treatment .Ahigher percentage of pupal mortality 16.6% at 4% concentrate has been observed, while no natural emergence carried out at concentrates of 4.6% comparing with control treatment of 86.66%, at the same time percentage of deformation has been increased to 16.66% at 4% of extracts and degressed to 6.66% at 6% while no deformation have been shown with control treatment .
... Show MoreThe determination of critical micelle concentration of selected non-ionic surfactants (Tween 20,40 and 80) have been investigated using magnetic water(MW)as an aqueous medium.Conductometry technique is used to determine critical micelle concentration.The effect of alcohol addition and temperature variation at the range(293.15 -303.15K) are also pursued. It is concluded that the process of micellization is spontaneous and endothermic because of the observed free energy of micellization (ΔGom) , enthalpy change of micellization (ΔHom), and entropy change of micellization (ΔSom) for the system was also studied.The properties of the non-ionic surfactants were studied, both in absence and presence of
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