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 absence of disorder, that can be interpreted as the mobility gap of the material.
الخلاصة:
ان المحادثة كانت الشغل الشاغل لكثیر من العلماء المھتمین بدراستھم بھذا المجال من امثال ساكس
.( واخرون ( ١٩٧٤ ) وغرایس ( ١٩٧٥ ) و شكلوف و اخرون ( ١٩٧٧ ) و دانكن ( ١٩٧٢ ) و بیرتن ( ١٩٨٠
قدمت بیرتن ( ١٩٨٠ ) تحلیلا لمسرحیة النادل الابكم لغرض تقدیم طریقتھا. تتوخى الباحثة من
تقدیم ھذا البحث تحلیل تركیب المحادثة منتدى حول القصة الادبیة و القصة الروائیة باستعمال نموذج بیرتن
١٩٨٠ ). و یمیل البحث الى الاجابة عن ا
يهدف البحث إلى الكشف عن تأثير الممارسات الأخلاقية الجامعية (السلبية والإيجابية) في تحديد مستوى جودة الأداء الجامعي، اختار الباحثان عينة من كليات الإدارة والاقتصاد في جامعات المنطقة الجنوبية مجالا للدراسة، واعتمد فرضية مفادها (يعتمد مستوى الأداء الجامعي على تجنب الممارسات السلبية في السلوك الأخلاقي الجامعي والالتزام بالممارسات الإيجابية). توصل البحث إلى مجموعة من الاستنتاجات من
... Show MoreThe international financial accounting and reporting standards IFRS/IAS represent the set of rules and foundations that the economic entity must follow in the measurement, presentation, and disclosure of the elements of the financial statements, the implementation of adopting the international financial reporting standards contributes to improving the qualitative characteristics of accounting information, so the current research aims to explain the role of adopting the International Accounting Standard (IAS) in improving the qualitative characteristics as well as analyzing the impact of the adoption of IAS.1 in improving the qualitative characteristics of accounting information within the financi
... Show MoreThe Esterification kinetics of acetic acid with ethanol in the presence of sulfuric acid as a homogenous catalyst was studied with isothermal batch experiments at 50-60°C and at a different molar ratio of ethanol to acetic acid [EtOH/Ac]. Investigation of kinetics of the reaction indicated that the low of [EtOH/Ac] molar ratio is favored for esterification reaction, this is due to the reaction is catalyzed by acid. The maximum conversion, approximately 80% was obtained at 60°C for molar ratio of 10 EtOH/Ac. It was found that increasing temperature of the reaction, increases the rate constant and conversion at a certain mole ratio, that is due to the esterification is exothermic. Activity coefficients were calculated using UNIFAC progra
... Show MoreIntroduction: Articaine was developed in 1969, with reported advantages which are increased potency, increased duration of its anesthetic effect and superior diffusion through bony tissue. The effectiveness of using 4% articaine infiltration for extraction of mandibular molar teeth in comparison to 2% lidocaine inferior alveolar nerve block is not settled yet. Aim: The aim of this study was to evaluate the effectiveness of using 4% articaine infiltration for extraction of mandibular molars by comparing it to the use of 2% lidocaine inferior alveolar nerve block in terms of success, the volume of local anesthetic agents and the pain experienced during the procedure. Materials and methods: A prospective randomized controlled study included
... Show MoreIntroduction: An aneurysmal bone cyst are enigmatic lesion of unknown cause and presentation and are difficult to distinguish from other lesions, it is a benign, but expansible tumor like lesion that generally occurs in the long bones. An aneurysmal bone cyst arising from the flat bone like clavicle is rare . Case presentation: We report a 12-year-old girl child with an aneurysmal bone cyst of the lateral third of left clavicle treated with enblock resection. The pathologic findings confirmed the diagnosis of aneurysmal bone cyst. The patient has been followed up for one year with no evidence of recurrence . Conclusion: En bloc resection can be curative and provide good results for this rare type of clavicle tumour.
The researchers reached many conclusions, the most important of which was the distinction of practitioners of sports activity with high degrees in the trait (social). At the same time, it was low in the trait (aggression –restraint-desisting) and non-practitioners were distinguished by sports activity with high degrees in the trait (aggression –restraint-desisting). In contrast, the degree was low in the trait (social), and there were significant differences in favor of practitioners of the activity of the athlete, Through the conclusions, the researchers recommend the need for university students to practice sports activities because of their positive impact on their health in general and on the deve
... Show MoreObjective: The aim of this study is to find out the impact of life events upon onset of depression, to describe the
prevalence of life events among depressed patients.
Methodology: Retrospective a case-control study conducted in AL-Diwanyia Teaching Hospital, Psychiatric
Department on A non-probability (purposive sample) of (60) depressed patients and (60) of healthy person were matched
with them from general population. The data were collected through the use of semi-structured interview by
questionnaire, which consists of two parts (1) divide, section A. cover letter and B. Sociodemographic data which consists
of 9-items, (2) Life events questionnaire consists of 51-items distributed to six dimensions include, family