فهرست مطالب محسن مزیدی

In the present study, mixed convection heat transfer of two-phase Newtonian and non-Newtonian nanofluids was examined in a ventilated cavity with internal barrier. Water - Aluminum oxide and water - copper oxide nanofluids are considered as working fluid, and the governing equations are discrete using a finite volume numerical method and solved by the Eulerian-Eulerian two-phase method. In this research, heat source has a constant thermal flux and all cavity walls are also thermally insulated; Finally, the effect of parameters such as Grashof number, volumetric fraction of nanoparticles, Reynolds number, type of nanofluid and different locations of the heat source were considered and Aluminum oxide nanoparticle with an ethylene glycol based fluid, which is converted to Bingham-type non-Newtonian fluid, has also been investigated. The results of this study show that with a Reynolds No. of 100 and Grashof No. of 105, the average Nusselt was 24.61% higher than that of pure water at the presence of copper oxide nanoparticles, and also by increasing the volume fraction of nanoparticles from 0.02 to 0.05, average Nusselt increase by 2.11 percent, indicating that water-copper oxide nanofluid has a better heat transfer than pure water.

Cross winds adversely affect the thermal performance of Heller dry cooling towers. In this experimental study, an isothermal model of Heller tower was used in wind tunnel to investigate the effect of windbreakers for increasing flow rate through the model under wind conditions. Windbreakers of various dimensions were installed at different angles around the model, and their effectiveness was studied under various wind directions. Results showed that use of windbreakers improved the flow rate by 30%. Moreover, with increase in wind velocity, effect of windbreaker length on the performance of the model was more pronounced. Results also indicated that for up to 30 degrees change in wind direction with respect to the diameter perpendicular to wind, there is no appreciable effect on the flow rate through the model.

Ambient temperature variations and cross winds are the most important environmental parameters affecting the performance of cooling towers, which can result in considerable economical losses to a power plant. In this paper, field and analytical study of these parameters and their effects on the performance of Heller cooling towers from economical point of view have been presented for a typical 240 MW power plant. Results show that at constant ambient temperature, with the increase in wind speed up to 6 m/s, the performance of the steam section of the power plant decreases by an average of 2.52%. Similarly, under still-air condition (no-wind condition), a 10 °C increase in the ambient temperature results in about 3.4% decrease in the performance of the steam section. The percentages of decrease in the performance of the steam section of the power plant are equivalent to reduction in the produced power amounting to 16.8 MW and 24 MW, respectively.

Coriandrum Sativum seeds are used as a traditional drug for the treatment of high-cholesterol and diabetic patients. This study aimed to determine the effect of oral administration of coriander seeds extract on the levels of blood glucose, lipid profile, and oxidative stress in experimental diabetic rats. In this experimental study, four groups of 15 male rats were divided into groups of normal control, normal treated with coriander seeds extract, diabetic, and diabetic treated with coriander seeds extract. Blood glucose higher than 300mg/dl was considered as an indicator of diabetes. Oxidative stress indicators, including superoxide dismutase, glutathione peroxidase, malondialdehyde, catalase and lipid parameters, including triglycerides, total cholesterol, HDL, and LDL, blood sugar, and weight of rats during the experiments, were measured. Data were analyzed using one-way ANOVA, repeated-measures ANOVA, and Duncan's test. The significance level was considered p<0.05. In this investigation, the serum levels of glucose, lipid profile (p<0.001) and oxidative stress level were significantly affected by oral consumption of coriander seeds extract. No significant differences were observed between the normal rats fed by coriander seeds extract and treated diabetic rats for catalase. There was no significantly difference between treatment groups and control and diabetic groups for catalase. Treatment of diabetic rates with coriander seeds extract improved all oxidative stress indicators, compared to non-treated diabetic rats. Based on the results of this study, oral administration of coriander seeds extract in experimental diabetic male rats can improve disorders of blood sugar, lipid profile, and oxidative stress indicators.

Healthy Eating Index (HEI) was first developed to assess and monitor nutritional status of Americans by the United States Department of Agriculture (USDA) in 1989. HEI is one of the scoring systems in nutritional researches. Since prison is an isolated place and prisoner’s state of health to some degree depends on the food consumed، therefore the nutritional status by this index might have some implementations for the policy makers. In a cross sectional study 435 prisoners (48 females and 387 males) were recruited using stratified random sampling method proportional to the ward population. Food intake from different sources in prison was assessed by analysing prison food menu، measuring wasted foods and food bought and provided by prison supermarkets. HEI score in Mashhad Central Prison was 80 percent of the total calculated score. Scores for consumption of fruit، meat and poultry، dairy products and food variety were 0، 4، 9. 5 and 9 respectively. Other food groups concerned with vegetable and cereals had scores of 10. Sodium intake representing the salt consumption was not measured. The results of this study showed that eating pattern of prisoners is healthy but steps might be taken to improve the quality of the food consumed.

Wind Towers are small towers, which have been used for the natural ventilation of the buildings in hot, arid regions of Iran since many years ago. When the wind blows, air enters the channel of wind tower, it transfers the heat to the internal surface of wind tower walls and finally the cool air comes into the building.The most important advantage of wind towers is air conditioning and air cooling without any use of electrical energy. In this study, the performance of the tallest wind tower of the world (wind tower of Dolatabad garden in city of Yazd) is analyzed by employing a CFD package. The temperature, perasure and velocity disturbutions of air at different cross-sections and along the column of wind tower are investigated. Heat transfer, fluid mechanics and thermodynamics principles are applied in order to evaluate the performance of wind towers. Finally, the results are presented.