The optical absorption data of Hydrogenated Amorphous Silicon was analyzed using a Dunstan model of optical absorption in amorphous semiconductors. This model introduces disorder into the band-band absorption through a linear exponential distribution of local energy gaps, and it accounts for both the Urbach and Tauc regions of the optical absorption edge.Compared to other models of similar bases, such as the O’Leary and Guerra models, it is simpler to understand mathematically and has a physical meaning. The optical absorption data of Jackson et al and Maurer et al were successfully interpreted using Dunstan’s model. Useful physical parameters are extracted especially the band to the band energy gap , which is the energy gap in the a
... Show MoreThe current study included the collection of soft samples for Ipomoea carnea Jacq. The anatomical properties of the leaf, which included the characteristics of the surface epidermis, the vertical section of the leaf, the transverse section of the petiole, the pedicel and the indumentum, as well as the study of leaf venation, were examined
DBN Rashid, International Journal of Innovation, Creativity and Change, 2020
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
... Show MoreIdentity 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
... Show MoreBackground : 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
... Show MorePollen 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
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