This research has presented a solution to the problem faced by alloys: the corrosion problem, by reducing corrosion and enhancing protection by using an inhibitor (Schiff base). The inhibitor (Schiff base) was synthesized by reacting of the substrates materials (4-dimethylaminobenzaldehyde and 4-aminoantipyrine). It was diagnosed by infrared technology IR, where the IR spectrum and through the visible beams proved that the Schiff base was well formed and with high purity. The corrosion behavior of carbon steel and stainless steel in a saline medium (artificial seawater 3.5%NaCl) before and after using the inhibitor at four temperatures: 20, 30, 40, and 50 C° was studied by using three electrodes potentiostat. The corrosion behavior was studied by cathode and anode polarization through which all corrosion parameters were investigated which include: corrosion current icorr (1341× 10-7-5393 × 10-9A/cm2), corrosion potential Ecorr (-1.031--0.227 mV vs SCE) , corrosion rates CR (0.658-0.007 mm.y-1), inhibition efficiency %IE (92-98%), and energy activation barriers Ea (4.709-26.733 kJ/mole). The thermodynamic and kinetic properties of the corrosion behavior of these two metals under study, which include: enthalpy ∆H*(2.153-24.176 kJ/mole), entropy ∆S*(-197 -156 J/mole), and freeGibbs energy ∆G*(59.87-74.56 kJ/mole) before and after using the inhibitor, were also studied
An experimental investigation has been made to study the influence of using v-corrugated aluminum fin on heat transfer coefficient and heat dissipation in a heat sink. The geometry of fin is changed to investigate their performance. 27 circular perforations with 1 cm diameter were made. The holes designed into two ways, inline arrangement and staggered in the corrugated edges arrangement. The experiments were done in enclosure space under natural convection. Three different voltages supplied to the heat sink to study their effects on the fins performance. All the studied cases are compared with v-corrugated smooth solid fin. Each experiment was repeated two times to reduce the error and the data recorded after reaching t
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In this paper,the homtopy perturbation method (HPM) was applied to obtain the approximate solutions of the fractional order integro-differential equations . The fractional order derivatives and fractional order integral are described in the Caputo and Riemann-Liouville sense respectively. We can easily obtain the solution from convergent the infinite series of HPM . A theorem for convergence and error estimates of the HPM for solving fractional order integro-differential equations was given. Moreover, numerical results show that our theoretical analysis are accurate and the HPM can be considered as a powerful method for solving fractional order integro-diffrential equations.
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solation of candida spp. From cancer patients who suffered oral candidiasis due to immunodeficiency
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Due to the importance of the extraction process in many engineering and medical industries, in addition to great interest in medicinal plants, in this research, microwave-assisted extraction has been applied to extract some active compounds from Rosmarinus officinalis leaves. The optimal extraction conditions were then determined by calculating the ratio and extraction efficiency. The process has also been described through kinetic study by applying five kinetic models, the Hyperbolic diffusion model, Power low model, the First order reaction model, Elovich's model, and Fick's second law diffusion model and determining their compatibility with the studies operation, and determining the kinetic constants for each model. The result
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Objective: The aim of this study is to determine the factors affecting birth space interval in a sample of women.
Methodology: A cross-sectional study conducted in primary health centers in Al-Tahade and Al- Shak Omar in
Baghdad city. Data were collected by direct interview using questionnaire especially prepared for the study.
Sample size was (415) women in age group (20-40) years who were chosen randomly.
Results: Analysis of data shows highest rate of women (31.8%) had a birth space interval of (8-12) months
followed by (26.7%) had a birth space interval of (19-24) months, (20.2%) had a birth space interval of (>24)
months and (16.1%) had a birth space interval of (13-18) months respectively, while lower rate of w