Experimental and numerical investigations of the centrifugal pump performance at non-cavitating and cavitating flow conditions were carried out in the present study. Experiments were performed by applying a vacuum to a closed-loop system to investigate the effects of the net positive suction head available (NPSHa), flow rate, water temperature and pump speed on the centrifugal pump performance. Accordingly, many of the important parameters concerning cavitation phenomenon were calculated. Also, the noise which is accompanied by cavitation was measured. Numerical analysis was implemented for two phase flow (the water and its vapor) using a 2-D simulation by ANSYS FLUENT software to investigate the internal flow of centrifugal pump under cavitating conditions. It was observed that with decreasing NPSHa, the values of the pump head, flow rate and efficiency initially remain constant, but with further reduction in NPSHa these parameters will decrease. Also, it was found that at 3% head drop the percentage drop of the flow rate is less than 2% whereas the percentage drop of the efficiency is greater than 3%. Numerically, it was noticed that the cavitation regions appear at the leading edge of suction side of the impeller blades which represents the lowest pressure area inside the computational domain of the centrifugal pump.
This research delts with study seven species of seeds and wild varieties wild belonging to the genus Medicago L., these species are: M. constricta Dur., M. coronata (L.) Bartal., M. intertexta (L.) Mill., M. intertexta.var. ciliaris (L.) Hyen., M. laciniata (L.) Mill., M. lupulina L., M. minima (L.) Bartal. and M. sativa L., the research involved characteristics of shapes, dimensions, colors and the nature of the surface ornamentation of seeds and also the hilum site. the seeds forms ranged between crescent, reniform and ovate, in addition there was a clear difference in seeds dimensions in height and width, while, the color has been vary between light brown to brown and dark brown. The nature of the surface ornamentation was smooth, retic
... Show MoreThis study was conducted with the aim to extract and purify a polyphenolic compound “ Resveratrol†from the skin of black grapes Vitis vinifera cultivated in Iraq. The purified resveratrol is obtained after ethanolic extraction with 80% v/v solution for fresh grape skin, followed by acid hydrolysis with 10% HCl solution then the aglycon moiety was taken with organic solvent
( chloroform). Using silica gel G60 packed glass column chromatography with mobile phase benzene: methanol: acetic acid 20:4:1 a
... Show MoreMany attempts have been made to modify the surface of orthodontic micro-implants and prevent the development of microbes by coating them with antimicrobial nanoparticles (NPs). The purpose of the present study was to evaluate the cytotoxicity of different NPs, namely, TiO2 and zinc oxide (ZnO) NPs, that are used to coat titanium orthodontic micro-implants.
Thirty orthodontic micro-implants were included in this study. Those were divided into three groups: control group without coating, TiO2-coated orthodontic micro-implants, and TiO2- and ZnO-coated orthodontic micro-implants. Scann
The research shows the importance of orientation towards the formulation of the green strategy and its effect in determining the behavior of the green municipal institution in Babel governorate. The research highlighted the formulation of the green strategy as an important variable, especially today, the trend towards protecting the environment and minimizing the damage resulting from the delivery of services, and through it also the type of green behavior or performance adopted by the municipal institution and the emergence of the need for a strategy that is not harmful to the environment. The research took the sample intentionally comprehensive size of 222 personnel of municipal institutions and some formations concerned with t
... Show MoreThe problem of the research is focused on importance limited of Iraq industrial companies in application of scientific measurements of supply chains performance, The research sought to achieve a group of goals, the most important are , identifying the strengths and weaknesses in the reality of supply chain in General Company for Cotton Industries, The data and information required are gathered from the dependence company, records through the field observations and personal interviews, the research used some quantitative indicators to measure of supply chain performance, The research reached to many conclusions , the most outstanding among them is the existence of a strong inverse correlatio
... Show MoreThe primary objective of this study was to identify the obstacles and problems encountered in the work of sports clubs according to the reality of the application of administrative automation. The present study was conducted in the sports club headquarters of Baghdad within the timeframe of October 2021 to December 2021. In the present study, a descriptive approach was used by the researchers in an analytical style according to the nature of the problem to be studied. The research community of the current study was composed of 100 sports clubs in the governorate of Baghdad. A total of 80 questionnaires were filled by the sample participants, who represented a percentage of 80% of the research community. After processin
... Show MoreAsset management involves efficient planning of economic and technical performance characteristics of infrastructure systems. Managing a sewer network requires various types of activities so the network can be able to achieve a certain level of performance. During the lifetime of the network various components will start to deteriorate leading to bad performance and can damage the infrastructure. The main objective of this research is to develop deterioration models to provide an assessment tool for determining the serviceability of the sewer networks in Baghdad city the Zeppelin line was selected as a case study, as well as to give top management authorities the appropriate decision making. Different modeling techniques
... Show MoreBackground:Periodontal diseases are infectious diseases in which periodontalpathogens trigger chronic inflammatory and immune responses. Interleukine-6 is a multifunctional cytokine playing a central role in inflammation and tissue injury.The aim of the study IS to determine the level of Interleukin-6(IL-6) in saliva of patients with chronic periodontitis compared to healthy subjects. Materials and Methods:The total subjects of the present study is 60, divided into 3 groups; 20 patients with chronic periodontitis with pocket depth(PD ≥4 mm)(group I), 20 patients with pocket depth(PD <4 mm) with clinical attachment loss (group II), and 20 healthy controls with pocket probing depth (PPD ≤ 3 mm) without clinical attachment loss (g
... Show MoreThe present study aimed to investigate the acetamiprid effects on biochemical aspects in albino mice. Thirty albino mice at the age of 6-8 weeks and average weight 25±5 g were divided into three groups each having ten (10) healthy mice. The first group was orally administrated with distilled water while the second and third groups were orally administrated with 50 mg/mL and 100 mg/mL respectively of acetamprid (0.1 mL) daily for one week. LD50 of acetamiprid was measured and found to be 200 mg/kg. The parameters of evaluations included liver function using Aspartate Aminotransferase (AST), Alanine Aminotransferase (ALT) and Alkaline Phosphatase (ALP). Lipid profile was anal
... Show Moren this study, 25 clinical isolates of Proteus spp. were collected from urine, wounds and burns specimens from different hospitals in Baghdad city, all isolates were identified by using different bacteriological media, biochemical assays and Vitek-2 system. It was found that 15 (60%) isolates were identifies as Proteus mirabilis and 10 (40 %) isolates were Proteus vulgaris. The susceptibility of P. mirabilis and P. vulgaris isolates towards cefotaxime was (66.6 %) and (44.4 %) respectively; while the susceptibility of P. mirabilis and P. vulgaris isolates towards ceftazidime was (20%). Extended spectrum β-lactamses producing Proteus was (30.7 %). DNA of 10 isolates of P. mirabilis and 4 isolates of P. vulgaris were extracted and de
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