Heat transfer process and fluid flow in a solar chimney used for natural ventilation are investigated numerically in the present work. Solar chimney was tested by selecting different positions of absorber namely: at the back side, front side, and at the middle of the air gap. CFD analysis based on finite volume method is used to predict the thermal performance, and air flow in two dimensional solar chimney under unsteady state condition, to identify the effect of different parameters such as solar radiation. Results show that a solar chimney with absorber at the middle of the air gap gives better ventilation performance. A comparison between the numerical and previous experimental results shows fair agreement.

The aim of the present study is to research two morphological processes: acronym and compounding (phrasal compounds/ circumlocution) and one syntactic category which are 'existential sentences' in science fiction short stories. The present paper identifies different types and rates of existential sentences. In this respect , 'bare existential and locative’ read the high percentages and may be contrasted with other classifications of English existential sentences which have a verb other than 'be' and a definite expression. 'Phrasal compounds' vary in rates as they constitute notable percentage for those that involve 'lexical means and lexical relations' followed by 'prepositional compounds' , 'conjunctional compounds' , and those invo

Background: Coated aesthetic archwires are currently the existing solutions for the esthetic problem, but the color of these archwires tends to change overtime. This study was aimed to evaluate the color stability of different types of esthetic archwires from four different companies at different time periods after immersion of two different staining drinks which are tea and Pepsi cola. Materials and methods: 48 specimens were prepared, each specimen contains 10 aesthetic archwires; and were divided according to type of solution into two groups: A (tea) &B (Pepsi cola); each group contained 24 specimens (12 specimens were immersed in the staining solution as 4 specimens for each time intervals and 12 specimens were immersed in distilled wa

One of the costliest problems facing the production of hydrocarbons in unconsolidated sandstone reservoirs is the production of sand once hydrocarbon production starts. The sanding start prediction model is very important to decide on sand control in the future, including whether or when sand control should be used. This research developed an easy-to-use Computer program to determine the beginning of sanding sites in the driven area. The model is based on estimating the critical pressure drop that occurs when sand is onset to produced. The outcomes have been drawn as a function of the free sand production with the critical flow rates for reservoir pressure decline. The results show that the pressure drawdown required to

This study was conducted to examine the anatomical aspects of Carissa macrocarpa, of stem, leaf and leaf venation. The results obtaind showed that the tissue of the studied parts have important anatomical characteristics in terms of the shape of the cross-sectional of stem and vertical-sectional of leaves. The stem section appeared in circular and the midrib was crescent shape and the stomata appeared on the upper surface of the leaf only, Tetracytic in type. Druses crystals and Aleurone granules appeared on both surfaces of leaves. The venation type was Brochidodromous in which the secondary veins do not end at the edge of the leaf, and each secondary race is connected with the higher rac

Identity is an influential and flexible concept in social sciences and political studies. The basic sense of identity is looking for uniqueness. In one sense, it is a sign of identification with those we assume they are similar to us or at least in some significant ways they are so. Globalization, migration, modern technologies, media and political conflicts are argued to have a crucial effect on identity representation in terms of the political perspectives specifically in the United States of America. This paper endeavors to investigate how American politicians represent their identities in speeches delivered in different periods of time namely from 2015 to 2018 in terms of the pragmatic paradigm. Three randomly selected speeches by fa

Background : The aim of this work is to study the clinical features and causative fungi of tinea pedis in diabetic and non-diabetic patients. Result : Tinea pedis was estimated to be the second most common skin disease in the United States, after acne. Up to 15% of the U.S., population may have tinea pedis. Across Europe and East Asia, prevalence rates reach 20 %. Methods: The Complete history taking regarding: age, sex, occupation, residency, history of diabetes and diabetic profile (fasting blood sugar and post prandial).and Clinical examination of the feet Aim of the study : The aim of this work was to study the clinical features and causative fungi of tinea pedis in diabetic and non-diabetic patients Conclusion : Tinea pedis is more

Pollen morphology characterization is an important field in taxonomy. This study aims to identify and characterize the pollen morphology for fourteen species from subfamily Caesalpiniodeae (Fabaceae). The results showed the similarity of all species pollen in terms of being monad and tri,zono-colporate type, and each Ceratonia siliqua and Senna occidentalis distinguished by having tetra,zono-colporate pollen as well, and the results revealed the prevalence of reticulate configuration in most studies species, while Ceratonia siliqua characterized by striates configuration, Cassia fistula distinguished by verrrucate-gemmate wall, and Senna species by verrrucate- perforate, as for the shape, showed a discrepancy in the general shape fr

The semantic analysis is characterized by its ability to describe the communicative pattern and its high efficiency in questioning its semantic manifestations and its deliberative purposes, which helped to understand the symbolic, contextual and cultural manifestations of the structure of the pattern, whether verbal or nonverbal. In order to highlight the role of the semiautomatic approach and its application to a sample of slogans collected from "media, social networking sites, in-kind views, media institutions, etc." to study the components and analyze the contents and highlight the signs. His boat logo is not just uttered as a linguistic transmission of a message, but as a political Tghieria actually . For example, the slogan "People Wan