The pumping station became widely used in many fields. Free surface vortices at intakes of pumps are not favorable. It may cause noise, excessive vibration, damage to the pumping structure, reduction in efficiency and flow for hydro-turbines, etc. One of the important problems encountered during the pump intake design is the depth of submergence and other design parameters to avoid strong free-surface vortices formation. This study aims to compute the critical submergence depth with some geometrical and hydraulic limitations by using Computational Fluid Dynamic (CFD) package. The mathematical model was validated with a laboratory model that had been conducted. The model of three intake pipes was investigated under five different submergence depth (S), three different spaces between intake pipes (b), and five different suction velocities (v). The results showed the best operation cases when the space between intake pipes (b) equal to 4D, the submergence depth of water is equal or greater than 1.25 from the bell mouth diameter of intake pipe (D), and the suction velocity less than 2 m/s. The worst case was when the space between the suction pipe (b) was (2D), in this case, the vortex appeared at submergence depth (S/D = 2) with suction velocity 3 m/s.
Background: Because of many factors play a role in the developing of late lower arch crowding, therefore the objective of the current study is to do vertical analysis for subjects with late lower dental arch crowding. The conducted study is the first attempt to do vertical analysis for Iraqi subjects with late lower arch crowding to see if there is a vertical discrepancy in such patients. Subjects and methods: Eighty subjects were selected according to certain inclusion criteria from patients attending the Orthodontic Department in the College of Dentistry, Baghdad University, patients ranged between 18-25 years old. The 80 patients were divided into two groups (crowding and normal), 40 patients each (20 males and 20 females). A study cast
... Show MoreThe great raise and development of residential buildings in modern cities worldwide as a result of urban extends leads to environmental and social problems, that make the designers looking for more complicated and innovative solutions. To encounter these, most advanced technologies in construction had been used resulting buildings had become higher, which was moved away from the land called residential housing. And with the development of these buildings, increase in the inhabitants inside; generate distant from nature, which increased the need for interactive outdoor recreational spaces open green in its high sections, was an alternative or complementary option to outer space at the ground level. Therefore, the research problem has emer
... Show MoreThe cartographic representation of geographical phenomenon considers the essential base in geographical analysis since as it supports the vertical house which is apartment houses consist of apartments which represent civil phenomenon , the aim of this study is to project the rule of cartographic representation methods in geographical analysis and make comparison in economic and social aspects for two approaches , the vertical and construction building methods.
The expand of city horizontally represent a problem in itself because it leads to loss of civil lands and overpass the agricultural lands as a result ,the ratio of habitation of land usage is so large in comparison with another usages of lands of the cities ; therefore ; many co
The dynamic response of foundation rest on collapsible soil in dry and soaked states is studied through wide experimental programmed. Gypseous soil from Tikrit governorate area was obtained and subjected to various physical and chemical analysis to determine its properties. Steel rectangular footing (400x200x20) mm is manufactured. The machine is fitted to the footing, then the model machine foundation is placed centrally over the prepared soil layer in steel container (1200x 1000x1000)mm with proper care to maintain the center of gravity of whole system lie in the same vertical line with container.Then, the footing is subjected to vertical harmonic loading using a rotating mass type mechanical oscillator to simulate different dynamic lo
... Show MoreThe Tigris River is one of the main rivers and an important resource for the population of Iraq. The present study aimed to quantify the concentration of surface-active substances in the Tigris River and to investigate the dynamics of this ecosystem. Five sampling sites were selected along the river within Baghdad city (Al-Muthanna Bridge, Al-Greaat Bridge, Al-Sarrafia Bridge, Al-Jadriyah Bridge, and Al-Za'franiya Area) for the period from July 2020 to April 2021. The study examined the relationship between the concentrations of surface-active materials (surfactants, including anionic and nonionic types) and their potential interaction with nutrients—nitrate (NO₃⁻), phosphate (PO₄), and sulfate (SO₄²⁻)—as well as the
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Magnetic abrasive finishing (MAF) process is one of non-traditional or advanced finishing methods which is suitable for different materials and produces high quality level of surface finish where it uses magnetic force as a machining pressure. A set of experimental tests was planned according to Taguchi orthogonal array (OA) L27 (36) with three levels and six input parameters. Experimental estimation and optimization of input parameters for MAF process for stainless steel type 316 plate work piece, six input parameters including amplitude of tooth pole, and number of cycle between teeth, current, cutting speed, working gap, and finishing time, were performed by design of experiment
... Show MoreIn this paper, an exact stiffness matrix and fixed-end load vector for nonprismatic beams having parabolic varying depth are derived. The principle of strain energy is used in the derivation of the stiffness matrix.
The effect of both shear deformation and the coupling between axial force and the bending moment are considered in the derivation of stiffness matrix. The fixed-end load vector for elements under uniformly distributed or concentrated loads is also derived. The correctness of the derived matrices is verified by numerical examples. It is found that the coupling effect between axial force and bending moment is significant for elements having axial end restraint. It was found that the decrease in bending moment was
in the
In recent years, English language teaching and second language acquisition has demonstrated a significant accentuation upon basic reasoning abilities improvement in the language capability advancement. Encouraging a point of view of duty to training basic intuition aptitudes in accordance with the English language courses, this paper gives an account of an investigation directed at theoretical meanings of basic deduction, drifts about the centrality of basic speculation for language educating and associations between critical thinking and language learning. The educators have the focal pretended by basic intuition in successful language teaching method, identified to Ennis’ (2011) critical thinking categories. The skill of thinking critic
... Show MoreZirconia ceramic restoration (ZCR) has a higher fracture incidence rate than metal ceramic restoration. Different surface treatments were used to improve fracture performance of ZCR such as grit blasting (GB) by aluminium oxide powder. This type of surface treatment generate residual stresses on veneering ceramic causing crack initiation and ending with a fracture. In order to overcome the stress generated by GB, zirconia surface coating is used as a surface treatment to improve fracture resistance and to accommodate stresses along the ZCR layers. Fifty zirconia ceramic crowns were fabricated and divided according to the type of surface treatment into three groups; the first group is (ZG), involving 20 cores were coated with a mixture of pa
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