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.
The skull is one of the largest bones in the body. It is classified into flat bones that maintain the important organic structures; which are the brain, eyes, and tongue. The skull is a strong support for preserving these organs but they are various according to the type of animals and the environments in which they live and the nature of their nutrition. There are many differences among living organisms in terms of the bones in the skull, their difference or disappearance and their length in the shape of the head. The samples were taken from the scientific storage in the Iraq Natural History Research Center and Museum; Cape hare Lepus capensis (Linnaeus, 1758) and Red fox Vulpes vulpes (Linnaeus, 1758) and the study was conducted o
... Show MoreThe other day in the Holy Quran and the four Gospels
The global oil market is one of the most important markets in the world and occupies especially for countries consuming and producing countries, and the status of understanding of the mechanism for determining prices in the market help to stand on many factors affecting oil demand and supply of oil and geopolitical factors, climate and alternative sources of energy .. etc. factors, and that the main objective of the research is to study the causes and results left behind by the oil price shocks in the world market, and the movement of these factors be through a cycle of energy that explain the strength of competition between these factors and their effects on prices, when demand increases evolution Large image leads to significan
... Show MoreThe aim of this study to investigate the tongue morphology and histology in house gecko Hemidactylus flaviviridis using light and scanning electron –microscopy (SEM ) technique.The morphology result revealed the presence of three parts : apex , body and lingual root .The light microscopy result showed that the tongue is covered with mucous membrane composed of non keratinized stratified squamous epithelium based on lamina propria which contain bundles of striated muscles its fibers in different directions including connective tissue , blood vessels and nerves. The lingual mucosa of the dorsal surface is covered with different pattern of lingual papillae which are widely distributed all over the dorsal surface except the apex. Noticed on t
... Show More
The present study is about tales attributed to certain people and are not traded. Such a study has a great importance for religion scholars and conveyors of hadiths since it is considered as one of the important sources of Islamic legislation that represent the Holy Sunna, and the majority of the recent study is concerned with non-traded tales of religion scholars. The research starts with the definition of such type of tales and then its types, conditions, legality, exceptions, and the benefit from studying such matter. It is mainly concerned with the opinions of the Imami and Hanafi region scholars respectively, and with comparing between the two doctrines i.e. Imami and Hanafi at the end of each
... Show MoreTourist business organizations face a challenging and the risks dynamic environment reflected its impact on the community and generate extra under pressure in the responsibilities and burdens of exceptional and affected much of factors, accidents and risks as a result of the actions and attitudes of disasters variety may exceed the geography of States border, which requires the absorption of risks facing the tourism and how to manage and deal with them scientific and reasonable grounds for the diagnosis and treatment of risk and how to reduce the aggravation and the different kinds.
As risks affecting the most important and vital to organizations as a tourist aspects of the market share and styles tourist
... Show MoreBackground: Hand, foot, and mouth disease is viral disease caused commonly by coxsackie virus A16 virus. It is a mild disease and children usually recover with no specific treatment within 7 to 10 days. Rarely, this illness may be associated with aseptic meningitis were patient may need hospitalization.
Objective: To determine significance of clinical features of hand, foot and mouth disease.
Methods: A cross sectional study of cases with clinical features of hand, foot and mouth disease visiting the dermatological consultation unit of Al Kindy teaching hospital. Sampling was for Zyona and Edressi Quarter patients over the period of 1st December 2017
... Show MoreAbstract The present study aimed to investigate the morphological description and histological structure of thyroid gland in Herpestes javanicus . The results revealed that thyroid gland in adult Herpestes javanicus is located in the neck region just below the larynx and attached to the trachea . Histological study revealed that thyroid gland in H. javanicus surrounded by a capsule of losse connective tissue and the thyroid gland mainly formed from follicles within different sizes. The results showed that the follicle consists of three compenets represented by follicular lining cells, basal parafollicular cells and the colloid. Microscopical examination revealed that the follicular lining tissue is either to be simple squamous or simple cub
... Show More