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.
Various simple and complicated models have been utilized to simulate the stress-strain behavior of the soil. These models are used in Finite Element Modeling (FEM) for geotechnical engineering applications and analysis of dynamic soil-structure interaction problems. These models either can't adequately describe some features, such as the strain-softening of dense sand, or they require several parameters that are difficult to gather by conventional laboratory testing. Furthermore, soils are not completely linearly elastic and perfectly plastic for the whole range of loads. Soil behavior is quite difficult to comprehend and exhibits a variety of behaviors under various circumstances. As a result, a more realistic constitutive model is
... Show MoreCarbon dioxide geo-sequestration (CGS) into sediments in the form of (gas) hydrates is one proposed method for reducing anthropogenic carbon dioxide emissions to the atmosphere and, thus reducing global warming and climate change. However, there is a serious lack of understanding of how such CO2 hydrate forms and exists in sediments. We thus imaged CO2 hydrate distribution in sandstone, and investigated the hydrate morphology and cluster characteristics via x-ray micro-computed tomography in 3D in-situ. A substantial amount of gas hydrate (∼17% saturation) was observed, and the stochastically distributed hydrate clusters followed power-law relations with respect to their size distributions and surface area-volume relationships. The layer-
... Show MoreThis study included the isolation and diagnosis of Pseudomonas aeruginosa from cases of burns samples. 100 samples were collected from resident patients at Al-Kindi Teaching Hospital, who suffer from different types of burns. Pseudomonas aeruginosa was isolated and diagnosed with 39% of the total samples. The cold and hot aqueous and alcoholic extract of flaxseeds oil was prepared and its inhibitory efficacy has been studied on the growth of isolated Pseudomonas aeruginosa. It is revealed that both extracts of flaxseeds oil had a high inhibitory effect on Pseudomonas aeruginosa growth. The Minimum Inhibitory Concentration (MIC) of flaxseed oil on the studied bacteria was also estimated, which was 25 mg/ml. In conclusion, the efficacy of fla
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The most famous thing a person does is talk. He loves and hates, and continues with it confirming relationships, and with it, too, comes out of disbelief into faith. Marry a word and separate with a word. He reaches the top of the heavens with a kind word, with which he will gain the pleasure of God, and the Lord of a word that the servant speaks to which God writes with our pleasure or throws him on his face in the fire. Emotions are inflamed, the United Nations is intensified with a word, and relations between states and war continue with a word.
What comes out of a person’s mouth is a translator that expresses the repository of his conscience and reveals the place of his bed, for it is evidence of
... Show MoreBackground: Small cardamom or green cardamom is the dried fruit of the tall perennial herbaceous plant, Elettaria cardamomum Maton belonging to the family Zingiberaceae. The major use of small cardamom on world wide is for domestic culinary purpose and in medicine. This study was conducted to test the effect of small cardamom extracts on Mutans streptococci and Candida Albicans in comparison to 0.2% chlorhexidine gluconate and de-ionized water in vivo. Materials and Methods: Mutans streptococci and Candid Albicans were isolated, purified and diagnosed according to morphological characteristic and biochemical test. In this experiments, the effect of control agents and small cardamom extracts as a mouth rinses was tested on the saliva
... Show MoreFibroblast growth factor-23, play an important role in atherosclerosis, endothelial dysfunction and vascular calcification. Sevelamer can improve vascular calcification, serum uric acid, low-density lipoprotein-cholesterol and Fibroblast growth factor-23. Aim of study Assessment the effect of sevelamer as phosphate binder against calcium carbonate on Fibroblast growth factor-23. Methods A prospective open-labelled study that included patients on hemodialysis. A total of 72 patients were screened, only 53 patients completed the 10 week period. Adults patients with serum phosphate as> 5.5 mg/dl were included. There were Group1: Includes 28 patients (19 males and 9 females receiving sevelamer carbonate (Renvela) tablet. Group 2: Include 25pati
... Show MoreAbstract:
The objective of this study, is to attempt to explain the reality of the Structural Imbalances in the Iraqi Economy during the period of research, by providing a quantitative analysis of the most important types of Imbalances, Which are represented by the disruption in the Productive Structure, the imbalance of the structure of Public Budget, and the imbalance of the Structure of Trade. The problem of the research, is the fact that the economy structure in Iraq has long suffered from an Imbalances in its economic structure, which are represented in the unequal relations between its constituent elements, according to the proportions levels defined by the economic theory.
... Show MoreThis work deals with the description of histopathological effects of the nematode Hartertia
gallinarurn Theiler. 1919 on the digestive system of the seesee partridge collected from Qa’ra
area in the western desert district of Iraq. along with some notes on intensity fluctuation of the
parasite according to the seasons. It is found that the major effects of the nematode are
necrosis and fibrosis of gizzard: granulomatous reaction. necrosis and mononuclear
infiltration of proventriculus: damage of mucosal lining of intestine and lymphocytic
infiltration of liver.