This research is concerned with the re-analysis of optical data (the imaginary part of the dielectric function as a function of photon energy E) of a-Si:H films prepared by Jackson et al. and Ferlauto et al. through using nonlinear regression fitting we estimated the optical energy gap and the deviation from the Tauc model by considering the parameter of energy photon-dependence of the momentum matrix element of the p as a free parameter by assuming that density of states distribution to be a square root function. It is observed for films prepared by Jackson et al. that the value of the parameter p for the photon energy range is is close to the value assumed by the Cody model and the optical gap energy is which is also close to the value of the Cody gap of these films. While for the films prepared by Ferlauto et al. the value of the parameter is equal to and .
The Iranian nuclear program was one of the most prominent issues in the international arena, in light of Iran's insistence on using it in various ways, and according to international changes, it came under pressure from the American side to impose packages of sanctions, which continued to our time, as it went to Russia and China to gain support in developing its nuclear activities. And, by virtue of the common interests that are linked between them, Iran has received great support from the last two countries in all fields to reach the final agreement in 2015, regarding asserting the peace of these activities, in addition to lifting all restrictions represented in the previous sanctions according to the Security Council resolutions, Aldo
... Show MoreThe extraction of Cupressus sempervirens L. or cypress essential oil was studied in this paper. This cypress oil was extracted by using the hydro-distillation method, using a clevenger apparatus. Cupressus sempervirens L. leaves were collected from Hit city in Al-Anbar province – Iraq. The influences of three important parameters on the process of oil extraction; water which used as a solvent to the solid ratio (5:1 and 14:1 (ml solvent/g plant), temperature (30 to 100 °C) and processing time, were examined to obtain the best processing conditions to achieve the maximum yield of the essential oil. Also, the mathematical model was described to calculate the mass transfer coefficient. Therefore, the best conditions, that were obtained in
... Show MoreIn the present investigation two different types of fiber reinforced polymer composites were prepared by hand lay-up method using three different parameters (curing temperature, pressing load and fiber volume fraction). These composites were prepared from the polyester resin as the matrix material reinforced with glass fibers as first group of samples and mat Kevlar fibers as the second group, both with different volume fractions (4%, 8%, and 12%) of fibers. They were then tested by tensile strength and impact strength. The main objective in this study is to use Taguchi method for predicting the better parameters that give the better tensile and impact strength to the composites, and then preparing composites at
... Show MoreThe research started from the basic objective of tracking the reality of organizational excellence in educational organizations on the basis of practical application. The research in its methodology was based on the examination of organizational excellence in the way of evaluating institutional performance. Tikrit University was selected as a case study to study the reality of application to the dimensions of organizational excellence in it, The results of the analysis for ten periods during the year and month. For the accuracy of the test and its averages, it was preferable to use the T test to determine the significance of the results compared to the basic criteria.
The research found that there is an o
... Show MoreWorld War II has brought suffering for all people; it has led people to have a nostalgic feeling. The war has many faces all of them are ugly, like death, separation, loneliness, violence, crime, betrayal, and disconnection and many other meanings. Michael Ondaatje in his novel The English Patient (1992) portrays a picture of the effect of World War II on four different characters; Hana a Canadian nurse, The English patient who is Hungarian, Caravaggio a Canadian-Italitan thief, and Kip an Indian sapper. They live together in one house, share their secrets and memories about World War II. Ondaatje brings them together to reveal their secrets and to heal their wounds of the war experience.
World War II has brought suffering for all people; it has led people to have a nostalgic feeling. The war has many faces all of them are ugly, like death, separation, loneliness, violence, crime, betrayal, and disconnection and many other meanings. Michael Ondaatje in his novel The English Patient (1992) portrays a picture of the effect of World War II on four different characters; Hana a Canadian nurse, The English patient who is Hungarian, Caravaggio a Canadian-Italitan thief, and Kip an Indian sapper. They live together in one house, share their secrets and memories about World War II. Ondaatje brings them together to reveal their secrets and to heal their wounds of the war experience.
Abstract:
The main objective of the research is to build an optimal investment portfolio of stocks’ listed at the Iraqi Stock Exchange after employing the multi-objective genetic algorithm within the period of time between 1/1/2006 and 1/6/2018 in the light of closing prices (43) companies after the completion of their data and met the conditions of the inspection, as the literature review has supported the diagnosis of the knowledge gap and the identification of deficiencies in the level of experimentation was the current direction of research was to reflect the aspects of the unseen and untreated by other researchers in particular, the missing data and non-reversed pieces the reality of trading at the level of compani
... Show MoreIn this study, we focused on the random coefficient estimation of the general regression and Swamy models of panel data. By using this type of data, the data give a better chance of obtaining a better method and better indicators. Entropy's methods have been used to estimate random coefficients for the general regression and Swamy of the panel data which were presented in two ways: the first represents the maximum dual Entropy and the second is general maximum Entropy in which a comparison between them have been done by using simulation to choose the optimal methods.
The results have been compared by using mean squares error and mean absolute percentage error to different cases in term of correlation valu
... Show MoreBragg Reflectors consist of periodic dielectric layers having an optical path length of quarter wavelength for each layer giving them important properties and makes them suitable for optoelectronics applications. The reflectivity can be increased by increasing the number of layers of the mirror to get the required value. For example for an 8 layers Bragg mirror (two layers for each dielectric pair), the contrast of the refractive index has to be equal to 0.275 for reaching reflectivity > 99%. Doubling the number of layers results in a reflectivity of 99.99%. The high reflectivity is purely caused by multiple-interference effects. It can be analyzed by using different matrix methods such as the transfer matrix method (TMM) which is the
... Show More