The present work investigates the effect of magneto – hydrodynamic (MHD) laminar natural convection flow on a vertical cylinder in presence of heat generation and radiation. The governing equations which used are Continuity, Momentum and Energy equations. These equations are transformed to dimensionless equations using Vorticity-Stream Function method and the resulting nonlinear system
of partial differential equations are then solved numerically using finite difference approximation. A thermal boundary condition of a constant wall temperature is considered. A computer program (Fortran 90) was built to calculate the rate of heat transfer in terms of local Nusselt number, total mean Nusselt number, velocity distribution as well as temperature distribution for a selection of parameters sets
consisting of dimensionless heat generation parameter (0.0 ≤ Q ≤ 2.0), conduction – radiation parameter (0.0 ≤ N ≤ 10.0), and the dimensionless magneto hydrodynamic parameter (0.0 ≤ M ≤ 1.0). Numerical solution have been considered for a fluid Prandtl number fixed at (Pr=0.7), Rayleigh number (102 ≤ ≤ 105 ) l Ra . The results are shown reasonable representation to the relation between Nusselt number and Rayleigh number with other parameters (M, N and Q). Generally, Nu increase with increasing Ra, M, N and Q separately. When the MHD, N, and Q effect added to the heat transfer mechanism, the heat transfer rate increased and this effect increased with increasing in Ra, MHD, N, and Q. The effect of magneto hydrodynamic, heat generation and heat radiation on the rate of heat transfer is concluded by correlation
equations. The results are found to be in good agreement compared with the results of other researchers.
The experiment was conducted in the glasshouse of Biology Dept. ,College of Education
Ibn- Al- Haitham ,University of Baghdad, during the growing season(2011), to study the
effect of sprying potassium sulphate at (0,200,400,600) ppm and cytokinin at (0,75,150)ppm
and their interactions on number of branches , protein percentage , carbohydrate percentage ,
absolute growth rate , biomass duration , relative efficiency of fertilizer and value of the
secondary productivity ,in Lentil plant cultivar(Baraka).
Results indicated that foliar sprying of potassium sulphate and cytokinin and their
interactions gave a significant effect on all vegetative growth parameters of lentil plant. the
concentration600 ppm of po
Background: White spot lesions (WSLs) are subsurface enamel demineralization manifested as white opacities which had an esthetic problem. The purpose of this in-vitro study was to evaluate the lesion depth improvement of WSLs following application of fluoride varnish, tooth mousse and resin infiltration (ICON). Materials and methods: Artificial WSLs were created on 120 premolar teeth using demineralization solution with pH (4-4.5). Samples randomly allocated into four groups; fluoride varnish, tooth mousse, ICON and untreated group. Groups were discolored in Cola and orange juice for 24 hours. Teeth were ground sectioned by longitudinal cutting then these sections examined and photographed under stereomicroscope at 12X magnification then an
... Show MoreWe described herein the synthesis of novel bis-1,3,4-oxadiazole containing glycine moiety. N-{5-[5-(4-methoxyphenyl)-1,3,4-oxadiazole-2-yl-sulfanyl]-1,3,4-oxadiazole-2-yl-methyl}-4methoxybenzamide was fully characterized by elemental analysis, FT-IR and 1H NMR spectroscopy. Also this study was designed to show the effects of bis-oxadiazole compound on the activities of some transferase enzymes such as: GOT, GPT and γ-GT in sera. This compound demonstrated activation on GOT and GPT activities, inhibitory effects on the γ-GT activity. These effects increased with the increasing of the concentration of the compound. The causes of the increases and decreases in the enzymes activities are discussed
Dissolution of gypsum rock in water is significant, which may result in hydrocarbon reservoir formation and evaporate deposits. However, the complexity of the gypsum dissolution process is still of interest because of its uncleanness that requires more critical analysis. The objectives of this experimental study are emphasis on the dissolution characteristics of gypsum rock under room temperature and by various types of water; namely: deionized, tap, fresh, acidic, well, and normal rainwatre. In addition, the influences of dissolution on gypsum rock's mechanical and physical characteristics. Gypsum rock was obtained from Agjalar area, in the southwest of Sulaymaniyah city, Northern Iraq. Experimental results show that we
... Show MoreIn this work, corrosion parameters were evaluated using potentiodynamic polarization curves. In order to determine corrosion parameters of potential and current density of the interesting metal, carbon steel, environmental conditions of external corrosion of buried carbon steel pipeline in Iraqi soil were prepared in the laboratory using simulated prepared conditions. Solutions of sodium chloride at different concentrations (300, 1100, 1900, 2700, and 3500 ppm) were used. pH of solution were acidic at pH =5, and alkaline at pH = 9. Laboratory conditions were similar to those of Iraqi soil where the pipelines were buried. Temperature was constant at 20 °C. Potentiodynamic polarization curves, of potential vs. log current density, were ob
... Show MoreThis study examined the effect of essential oils extracted from peel of Citrus paradisi and Citrus sinensis on two species of fungi: Penicillium oxalicum and Fusarium oxysporum as well as effect of two fungicides: Carbendazim and Thiophanatemethyl against above fungi. Results showed that the essential oil of Citrus paradisi inhibited the radial growth of Penicillium oxalicum and Fusarium oxysporum at concentration 4%. Nevertheless, the essential oil of Citrus sinensis inhibited the radial growth at concentration 5 and 4%, respectively. Furthermore, the two studied fungicides inhibited radial growth of these fungi too. Therefore, there are a positive relationship between the evaluating of concentration and the percentage of inhibiting of rad
... Show MoreIn this study 77 human isolates of Staphylococcus aureus were obtain from different clinical sources. The results showed that the number of isolates producing α-hemolysin was 32 isolates (41.55%) , while non- hemolysin producing was 45 isolates (58.45%) .The minimum inhibitory concentration (MIC) of methicillin which were 32 micrograms \ ml. The effect of CD-Cholesterol ,Cholesterol ,Cyclodextran(CD) ,Methicillin and Phosphate Buffer Saline(PBS) on α- hemolysin activity was study and the hemolytic Titer was:8 ، 32.768 ,65.536 ,
140.737.488.355.32 , 4.961408E + 25 respectively, while the effect of the same effect with Titer 67.108.864 and low Titer with PBS 3.96140812E + 25. The α – hemolysin toxin was partialy purified by ammoni
This paper presents the study and analysis, analytically and numerical of circular cylindrical shell pipe model, under variable loads, transmit fluid at the high velocity state (fresh water). The analytical analysis depended on the energy observation principle (Hamilton Principle), where divided all energy in the model to three parts , strain energy, kinetic energy and transmitted energy between flow and solid (kinetic to potential energy). Also derive all important equations for this state and approach to final equation of motion, free and force vibration also derived. the relations between the displacement of model function of velocity of flow, length of model, pipe thickness, density of flowed with location coordinate x-axis and angle
... Show MoreThis work was conducted to study the treatment of industrial waste water, and more particularly those in the General Company of Electrical Industries.This waste water, has zinc ion with maximum concentration in solution of 90 ppm.
The reuse of such effluent can be made possible via appropriate treatments, such as chemical coagulation, Na2S is used as coagulant.
The parameters that influenced the waste water treatment are: temperature, pH, dose of coagulant and settling time.
It was found that the best condition for zinc removal, within the range of operation used ,were a temperature of 20C a pH value of 13 , a coagulant dose of 15 g Na2S /400ml solution and a settling time of 7 days. Under these conditions the zinc concentrat