A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave number (1 & 0.75) for Rayleigh number of (1000).
Growing interest in the subject of corporate governance after the repercussions of financial collapses of some of the leaders of American companies and European, and the consequent crisis of confidence in global financial lists of companies due to weak accounting disclosure and transparency, was quick from many countries and international organizations to adopt the concept in an attempt to improve the situation of companies and promote transparency and prevent further financial crises in the future. Based on this background, the present study aims to shed light on the concept of exercising the powers of governance that has become invitations for adoption in Iraq of great importance, given the increasing role of corporations both restrict
... Show MoreThis research is an attempt to study and evaluate the maintenance function at Factory 7 - The State General Company for Leather Industries, and to design a computerized preventive maintenance system to design and to analyze preventive maintenance. To accomplish the objectives of this research, data were gathered and analyzed according to the reliability engineering criteria for the period 2/1– 30/6/2005, then a preventive maintenance plan was designed for each machine of the sample study using the computerized system designed in this research. A Monte Carlo Simulation methodology was used for the purpose of evaluating the performance of the preventive maintenance plan of each machine for one year. The simulation res
... Show MoreThe objective of the current research is to identify the effective of the suggested instructional design that based on the teaching strategy for understanding in achievement for students(girls) of mathematics in the fifth grads secondary school. To achieve the research goal, the empirical research method is depended. In this method a realistic empirical design pre-test of two equivalent sets to determine the students’ grade is used. The following zero hypotheses is formulated “There is no statistical difference for the faction at 0.05 between the mean grad for the students of the empirical group who studied the subject using the Instructional design based on the teaching strategy for understanding and those who studied the same subje
... Show MoreThe research aimed to study the role that the media play in shaping the public knowledge of human rights issues among the people of Kirkuk, which will be the focus of the study. The research was conducted by applying a survey panel to a random sample of the city's audience. The research dealt with the theoretical aspect of a theory that relied on the media, and the loans provided by the theory, on the basis of which the research was conducted and the research problem was determined based on a major question: What is the role that the mass media play in developing the knowledge of members of the public on human rights and the relationship between the intensity of view in that, as well as the identification of the effect of two variables G
... Show MoreIn this study, the photodegradation of Congo red dye (CR) in aqueous solution was investigated using Au-Pd/TiO2 as photocatalyst. The concentration of dye, dosage of photocatalyst, amount of H2O2, pH of the medium and temperature were examined to find the optimum values of these parameters. It has been found that 28 ppm was the best dye concentration. The optimum amount of photocatalyst was 0.09 g/75 mL of dye solution when the degradation percent was ~ 96 % after irradiation time of 12 hours, while the best amount of hydrogen peroxide was 7μl/75 mL of dye solution at degradation percent ~97 % after irradiation time of 10 hours, whereas pH 5 was the best value to carry out the reaction at the highest deg
... Show MoreThe present study included the microscopic and molecular identification of Entamoeba histolytica by using specific primers to detect four virulence factors possessed by Entamoeba histolytica. Virulence factors included Active Cysteine proteinase, Galactose/N-acetyl-D-galactose-lectin, Amoeba pore C and Phospholipase. Titanium dioxide nanoparticles (TiO2NPs) were synthesized from Pseudomonas aeruginosa which producing Pyocyanin pigment as a reducing agent to form it. After that we studied the ability ofTiO2NPs to inhibit virulence factors production and curing the genes responsible for encoding them by using four different dose 2 ,3, 4, 6 mg/Kg and administered by intraperitoneal injection
... Show MoreManuscript (Tuhfat Al-Ashaba and the Nuzha Al-Kulbab) by Ahmed bin Ibrahim Al-Hanafi Al-Suruji (d.710 AH / 1310 AD), one of the important manuscripts as an encyclopedia characterized by the diversity of its topics
As we know the transportation studies regarded as one of a very
important and difficult studies and one of its difficulties created from the
process of data updating therefore the researcher well facing many difficulties
to balancing between the old data on collecting new data.
The research present an opinion which is summarized by: can we use
the old data after we updated and used it as alternatives? Or the researcher
must collect new data to complete their research which indicate to the present
situation and some times they cant complete their studies because of the
security, economic, temporally difficulties.
The research used two kinds of data, the old data which belong to the
period (1998) and new data
هدف البحث إلى معرفة تقويم الكفاءة الادارية لأعضاء اللجان المشرفة على التطبيقات التدريسية في كليات التربية بجامعة بغداد من وجهة نظر التدريسيين المشرفين عليها. اعتمد البحث المنهج الوصفي التحليلي. وتكون مجتمع البحث من (162) مشرفاً على التطبيقات التدريسية من كليات التربية/ جامعة بغداد، واختيرت عينة البحث بالطريقة العشوائية البسيطة، وبلغ عدد أفراد العينة (120) مشرفاً من الكليات آنفة الذكر. وتم بناء استبانة تضمنت (35)
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