A numerical study of the double-diffusive laminar natural convection in a right triangular solar collector has been investigated in present work. The base (absorber) and glass cover of the collector are isothermal and isoconcentration surfaces, while the vertical wall is considered adiabatic and impermeable. Both aiding and opposing buoyancy forces have been studied. Governing equations in vorticity-stream function form are discretized via finite-difference method and are solved numerically by iterative successive under relaxation (SUR) technique. Computer code for MATLAB software has been developed and written to solve mathematical model. Results in the form of streamlines, isotherms, isoconcentration, average Nusselt, and average Sherwood number, are presented for wide range of the buoyancy ratio , angle of inclined glass cover with horizontal coordinate , Lewis number , thermal Rayleigh number , and Prandtl number . The results show that above parameters have strong influences on the patterns of streamline, isotherms, isoconcentration, average Nusselt number and average Sherwood number. Results show that a decrease in the angle of inclined glass cover with horizontal coordinate ( leads to increase average Nusselt number and average Sherwood number. For (N > 0), both average Nusselt number and average Sherwood number increase with increasing of buoyancy ratio and Rayleigh number. By contrast for ( these values decreases. Also, increasing of the buoyancy ratio for positive (N > 0), at the same Rayleigh number enhance the heat and mass transfer rate. A comparison is made with the previous numerical results and it found to be reveal a good agreement.
A Factorial Study for separation anxiety in students, of Baghdad City
Summary: The study focused on the role of the educational counselor in schools, as an integral part of the educational system that faces multiple challenges and difficulties. In this context, the counselor’s role becomes crucial in attempting to reduce or eliminate such difficulties, in addition to guiding students in an appropriate manner. Methodes: The study employed a descriptive field approach, using interviews and direct observation as tools to examine the actual role performed by school counselors. Results: The study concluded with several key findings, most notably the numerous challenges faced by counselors, including students’ negative behaviors, school dropouts, and the limited administrative support for counselors’ work. Fu
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The primary objective of the present research is to diagnose the most mportant imensions of quality of work life in a sample of individuals working in the Northern Gas Filling Company in Nynawa. The study sample consisted of 140 employees of the Northern Region Filling Company in even ,Through a questionnaire prepared for this purpose. The study concluded that there are five main factors that are considered to be measure of the quality of working life and are based on their importance: Empowerment, organizational health, internal work environment, motivation, development and training of workers. The study recommended that the organization should payattentio
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The researchers wanted to make a novel azo imidazole as a follow-up to their previous work. We focused on the ligand 4-[(2-amino-4-phenylazo)- methyl]-cyclohexane carboxylic acid as a derivative of trans-4- (aminomethyl) cyclohexane carboxylic acid diazonium salt, synthesized a series of its chelate complexes with metal ions, and characterized these compounds using a variety techniques, including elemental analysis, FTIR, LC-Mass, NMR and UV-Vis spectral process as well TGA, conductivity and magnetic quantifications. Analytical data showed that the Cr(III), Mn(II) and Zn(II) complexes out to 1:1 metal-ligand ratio with octahedral geometry except Mn complex has tetrahedral geometry.
Cluster analysis (clustering) is mainly concerned with dividing a number of data elements into clusters. The paper applies this method to create a gathering of symmetrical government agencies with the aim to classify them and understand how far they are close to each other in terms of administrative and financial corruption by means of five variables representing the prevalent administrative and financial corruption in the state institutions. Cluster analysis has been applied to each of these variables to understand the extent to which these agencies are close to other in each of the cases related to the administrative and financial corruption.
In this paper a comparison of the experimental of evacuated tube solar water heater systems with and without mirror flat reflector. The aim of using the reflector to improve thermal efficiency, and the data gathered which are (temperature, solar irradiation and time) for three days were compared. the results from compared data the temperature lower increase in evacuated tube solar water heater system without reflector than the temperature increase in evacuated tube solar water heater system with reflector .The results show (53, 39, 35) % for three days respectively that the evacuated tube solar water heater system with reflector has higher thermal efficiencies than the results (47, 28, 30) % for three days respectively thermal efficiencies
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The structure, optical, and electrical properties of SnSe and its application as photovoltaic device has been reported widely. The reasons for interest in SnSe due to the magnificent optoelectronic properties with other encouraging properties. The most applications that in this area are PV devices and batteries. In this study tin selenide structure, optical properties and surface morphology were investigated and studies. Thin-film of SnSe were deposit on p-Si substrates to establish a junction as solar cells. Different annealing temperatures (as prepared, 125,200, 275) °C effects on SnSe thin films were investigated. The structure properties of SnSe was studied through X-ray diffraction, and the results appears the increasing of the peaks
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