The steady state laminar mixed convection and radiation through inclined rectangular duct with an interior circular tube is investigated numerically for a thermally and hydrodynamicaly fully developed flow. The two heat transfer mechanisms of convection and radiation are treated independently and simultaneously. The governing equations which used are continuity, momentum and energy equations. These equations are normalized and solved using the Vorticity-Stream function and the Body Fitted Coordinates (B.F.C) methods. The finite difference approach with the Line Successive Over-Relaxation (LSOR) method is used to obtain all the computational results. The (B.F.C) method is used to generate the grid of the problem. A computer program (Fortran 90) is built to calculate the steady state Nusselt number (Nu) for Aspect Ratio AR (0.55-1) and Geometry Ratio GR (0.1-0.9). The fluid Prandtl number is 0.7, Rayleigh number Ra = 400, Reynolds number Re = 100, Optical Thickness (0 ≤ t ≤ 10), Conduction- Radiation parameter (0 ≤ N ≤ 100) and Inclination angle λ = 45. For the range of parameters considered, results show that radiation enhance heat transfer. It is also indicated in the results that heat transfer from the surface of the circle exceeds that of the rectangular duct. Generally, Nu is increased with increasing GR, t and N but it decreased with AR increase. When the radiation effect added to the heat transfer mechanism, the heat transfer rate increased. This effect increased with increasing in GR and decreasing with AR. The increasing in radiation properties lead to increase the radiation effect. Tecplot 7 program was used to plot the curves which cleared these relations and isotherms and streamlines which illustrate the behavior of air through the channel and its variation with other parameters. A correlation equation is concluded to describe the radiation effect. Comparison of the results with the previous work shows a good agreement.
Reaction of L1 [((E)-N1-(nitrobenzylidene)benzene-1,2-diamine] and L2( m-aminophenol), and one equivalent of di- or tri-valent metals(Cr(ӀӀӀ), Mn(ӀӀ), Fe(ӀӀӀ), Co(ӀӀ), Ni(ӀӀ), Cu(ӀӀ) and Zn(ӀӀ) afforded the complexes [M(L1)(L2)2]Cl, M=Cr(ӀӀӀ) and Fe(ӀӀӀ) and the complexes [M(L1)(L2)2] M= Mn(ӀӀ), Co(ӀӀ), Ni(ӀӀ), Cu(ӀӀ) and Zn(ӀӀ). The structure of the Schiff base ligand and their complexes are characterized by (C:H:N), FT.IR, UV.Vis, 1HNMR, 13CNMR and mass spectral. The presence of metal in the complexes are characterized by flame atomic absorption. The spectral data of the complexes have revealed the octahedral geometry. The (L1), (L2) and mixed ligand metal complexes were screened for their ability as cataly
... Show MoreSalicylaldehyde was react with 4-amino-2,3-dimethyl-1-phenyl-3-pyrazoline-5-on to produce the Schiff base ligand 2,3-dimethyl-1-phenyl-4-salicylidene-3-pyrazoline-5-on (L). The prepared ligand was identified by Microelemental Analysis, and FT.IR, UV-Vis spectroscopic techniques. A new complexes of Fe(III),Co(II),Ni(II),Cu(II),Ce(III) and Pb(II) with mixed ligands of dithizone (DTZ) and Schiff base were prepared in aqueous ethanol with a 2:2:1 M:L:DTZ. The prepared complexes were characterized using flame atomic absorption, (C.H.N) Analysis, FT.IR and UV-Vis spectroscopic methods as well as magnetic susceptibility and conductivity measurements. In addition biological activity of the ligands and complexes against two selected type of bacteria
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Background: The success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. The purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. Materials and Methods: Forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. Standardized preparation of all teeth samples were carried out to receive full contour zirconia crown re
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Background: The success and maintenance of indirect dental restorations is closely related to the marginal accuracy, which is affected by many factors like preparation design, using of different fabrication techniques, and the time of taking final impression and pouring it. The purpose of this in vitro study was to evaluate the effect of different pouring time of conventional impression on the vertical marginal gap of full contour zirconia crowns in comparison with digital impression technique. Materials and Methods: Forty sound recently extracted human permanent maxillary first premolar teeth of comparable size and shape were collected. Standardized preparation of all teeth samples were carried out to receive full contour zirconia crown re
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The research is based on the basic idea that companies today are moving towards a new trend towards protecting the environment coupled with the increasing wareness of the pollution damage caused by these companies due to their operations and activities in the environment. The two main reasons that led the researchers to choose this subject is the need to adapt the companies themselves in response to successive developments, The great development was that companies moved from the sole economic responsibility of the business to social responsibility by emphasizing socially responsible profit. The problem of research is the knowledge of the availability of the dimensions of the green processing series in Kirkuk Cement Factory The re
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Various Hall Effects have been successfully observed in samples of n-type indium antimonide with values for conductivity, energy gap, Hall mobility and Hall coefficient all agreeing with theory. A particular interest in developing a method for obtaining accurate values of carrier concentrations in semiconductor samples has been fulfilled with an experimental result of (1.6×1016 cm-3 ±10.7%) giving a percentage difference of (6.7%) to a quoted value of (1.5×1016cm-3) at (77K) using an (80mW C.W. CO2) laser beam at (10.6μm) to illuminate a similar sample of n-type indium antimonide, an "Optical" Hall effect has been observed. Although some doubt has been raised as to the validity of effect i.e. "thermal" rather than "Optical", values o
... Show MoreThe problem of research lies in answering some of the question: What is the reality of (vital conscience) in some colleges and departments of physical education and sports science in Baghdad from the viewpoint of the teachers? And The aim of the research is to prepare a scale (the vitality of the conscience) and learn about its reality in colleges and departments of physical education and sports science in Baghdad from the viewpoint of teachers and The researcher relied on the descriptive method in the survey method and the relationships related to the nature of the research problem and The sample of the research was senior administrators teaching some colleges and departments of physical education and sports science in Baghdad , Th
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The game of volleyball, like all other sports, has been made by new amendments, the most important of which is the system of what is not the system of the free player in 1998, which gave added importance to the skills of receiving the transmission and defending the stadium being one of the important skills where the law allowed the free player to move and position in the back positions of the stadium Limited support mainly defensive skills. This is to make the state of stability and balance between defensive and offensive skills, which helps in the development of the game and make it exciting and enjoyable for players and fans. Therefore, the researchers decided to shed light by identifying the percentage of the contribution of the free pla
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