Because of Cadmium selenide quantum dots (CdSe quantum dots) has a tuning energy gap in the visible light range, therefore; it is provided a simple theoretical model for the absorption coefficient of CdSe quantum dots, where the absorption coefficient determines the extent to which the light of a material can penetrate a specific wavelength before it is absorbed. CdSe quantum dots have an energy gap can be controlled through two effects: the temperature and the dot size of them. It is found that; there is an absorption threshold for each directed wavelength, where CdSe quantum dots begin to absorb the visible spectrum at a size of 1.4 nm at room temperature for a directed wavelength 300 nm. It has been observed that; when the wavelength is increasing its absorption threshold is increased. For wavelengths (400, 500, 600) nm, the absorption thresholds for each quantum sizes are (1.8, 2.2. 3.2)nm respectively. On the other hand, a rising of the temperature led to reduces the absorption coefficient value, that at 400 K for all quantum sizes, the absorption coefficient increases >2000cm−1(According to the directed wavelength) than it is at 0 K. CdSe quantum dots can be considered as one of the most promising materials because it has a tuning gap for the visible wavelengthsfor different applications, such as light-emitting diodes in different colors of the visible spectrum. It is found that; there is a good agreement between our theoretical calculations and experimental results.
كان لنهاية الحرب الباردة وعولمة العالم على وفق رؤية كونية تتجاوز حدود ومفاهيم السيادة الوطنية والقومية الاثر الواضح في ترتيب العلاقات الدولية , واصبحت تلك العلاقات تدور حول محورين الاول .. هو الاعتماد المتبادل بين الدول من اجل الوصول الى خطوط مشتركة للمصالح المختلفة بين هذه الدول . والآخر.. هو تبعية الدول الضعيفة للدول القوية لافتقار الاولى توفير الحاجيات الى مواطنيها . هذا يشير الى نشأة علا
... Show MoreThe goal of this research is to introduce the concepts of Large-small submodule and Large-hollow module and some properties of them are considered, such that a proper submodule N of an R-module M is said to be Large-small submodule, if N + K = M where K be a submodule of M, then K is essential submodule of M ( K ≤e M ). An R-module M is called Large-hollow module if every proper submodule of M is Large-small submodule in M.
Urban wetlands are one of the complex systems that provide many economic, social and environmental services to the city. In this research, the most important services provided by urban wetlands from the point of view of the urban planner were reviewed, and the types of these lands and their divisions according to the type of services provided by each type were presented. Environmental is represented in its ability to reduce the dangers of floods, mitigate the climate and reduce its negative impacts, purify water and deplete a lot of suspended impurities and pollutants, and social services such as recreational areas and beautiful landscapes that inspire joy and reassurance in the soul, as well as cultural areas and sports activities for m
... Show MoreThe financial fraud considers part of large concept to management and financial corruption, the financial fraud is appeared especially after corporate, that is Emerge agency theory, that is because recognize relationship between the management company and stakeholder, that is through group from constriction in order to block the management to fraud practice, that on the basis was choose another party in order fraud this practice and give opinion on financial statement, that consider basis decision making from stakeholder to basis the report auditor about creditability this is statement that reflect real activity for the company.The Auditor in order to lead work him Full professionalism to must using group from control Techniques, that is
... Show MoreIn the present study ten samples of bottled water from Baghdad conservative were taken to measure the concentration of radon gas by using nuclear track detector LR-115.The result obtained are varying from(0.033)to(0.007)pCi.l-1and these values are very low than the allowed limits (5) pCi.l-1, and specific activity from bottled water has been calculated which was vary from (0.00027)to(0.00126) Bq.l-1 and these values are very low than allowed limits (0.0123) Bq.l-1 that mean the bottled water was treated with good treatment to decrease the side effect of radon
The present study aims to describe the histological structure of kidney of, (Herpestes javanicus ) that inhabits Iraqi lands. Transverse sections of kidney stained with hematoxylin and eosin showed two distinct regions, the outer thin darkly stained cortex and inner thick lightly stained medulla, which further subdivided into external and internal medullary zones linked with one conical renal papilla. The lateral margin of the outer medullary tissue forms a secondary renal pyramid with a specialized fornix. All the nephrons in the kidney start with the renal corpuscle [Malpighian], which is formed from two distinct parts, these are a centrally located glomerulus, which represented by a tuft of blood capillaries and an outer Bowman’s capsu
... Show MoreTranslation as a human endeavor has occupied the attention of nations since it bridges the gab between cultures and helps in bringing out national integration. The translation of Kurdish literature started with personal efforts in which newspapers and magazines had played a vital role in supporting translation and paved the way for promoting the publication of Kurdish products.
The bulk of the materials translated from Arabic exceeds that translated from other languages owing to the influence of religious and authoritarian factors.
The survey of the Kurdish journals was limited to the period 1898-1991 since it marked a radical and historic change represented by the birth of Kurdish journalis
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