Ab – initio restricted Hartree - Fock method within the framework of large unit cell (LUC) formalism is used to investigate the electronic structure of Si and Ge nanocrystals. The surface and core properties are investigated. A large unit cell of 8 atoms is used in the present analysis. Cohesive energy, energy gap, conduction and valence band widths are obtained from the electronic structure calculations. The results are compared with available experimental data and theoretical results of other investigators. The calculated lattice constant is found to be slightly larger than the corresponding experimental value because we use only 8 atoms and we compared the results with that of the bulk crystals, nanoclusters are expected to have stronger directional bonds that in their bulk structure. The surface states are found to be mostly non-degenerated because of the effect of surface discontinuity and the existence of oxygen atoms. Valence and conduction bands are found to be wider on the surface due to the splitting of energy levels due to the existence of oxygen atoms. The present method can be used to investigate the electronic structure of bulk, surface and nanocrystals.
Abstract:
The distribution or retention of profits is the third decision among financial management decisions in terms of priority, whether at the level of theory or practice, as the issue of distribution or retention is multi-party in terms of influence and impact, as determining the optimal percentage for each component is still the subject of intellectual debate because these decisions are linked to the future of the organization and several considerations, The research focus on the nature of the policies followed by the Iraqi banking sector As the sample chosen by the intentional sampling method was represented by the Commercial Bank of
... Show MoreThis research aimed to identify the structural model of the relationship between emotional creativity and self-efficacy among male and female students of the preparatory year at Tabuk University. The current study adopted the descriptive correlational approach, as it is appropriate to the nature of the study. The study tools contained (60) items that measure the relationship between emotional creativity and self-efficacy among the male and female students of the preparatory year at Tabuk University. The study sample was chosen by the stratified random method of the study community, where the study sample reached (183) male and female students of the preparatory year at the University of Tabuk. The results of the study showed that there a
... Show MoreThrust blocks and restraint joints are the two most popular methods of counteracting the thrust force that generated at pipe fittings (bends, Tee, wye, reducers, dead ends, etc…). Both systems perform the same function, which is to prevent the joints from separating from the pipes. The aim of the study is to review previous studies and scientific theories related to the study and design of thrust blocks and restraint joints to study the behavior of both systems under thrust force and to study the factors and variables that affect the behavior of these systems. The behavior of both systems must be studied because they cannot be abandoned, as each system has conditions whose use is more feasible, scientific, and economic
... Show MoreThe study aimed at ideutifying the impact of scieutific skills in strategy and liabits of mind amony stueuts in tenth grade . The study demanded to choose a sampie that coutaiun (42) student of the fourth grade of the secondary school who were dirided into tow groups , the first is experimental studied according to scieutific skill strategy , and the other controlling , studied according to the usualway . An achievement test has been taken that adopted staudard for mind skills as research tools that are applid after ascertaining sincerity proved at the end of the experiment .The study has reached to the conclusion that there are statistically significant differnces in farour of the experiment group in both
... Show MoreThe actor has mechanisms that were applied in the performance، as it formed a style in the theatrical form (weird)، and the researcher deliberately studied these mechanisms and divided them into four chapters.
The researcher divided it into two sections، the first is the actor's performance requirements، and the second is the boring performance methods in the directors' theater، and then the researcher concluded the second chapter with the most important indicators.
As for the third chapter، the researcher determined the society of his research and the method of selecting the sample (strange) and analyzing the sample and concluded with the most important results of the sample analysis.
A total of 72 specimens of the wild jungle cat Felis chaus furax De Winton, 1898 were
examined for the purpose of this study. The results show that 55.6% of the sample harbored
either single or mixed infections with ecto- and/ or endoparasites. The mode of infection
shows that only four specimens( 5.6% of the total sample) acquire single infections, the
double infections comprise 15.3%, the triple infections comprised 33.3%, while the
quadruplicate infections comprised 1.4%.
The systematic list of the parasites included six ectoparasites: Ctenocephalides felis (insect),
Sarcoptes scabiei (mite), Haemaphysalis adleri, Rhipicephalus leporis, Rhipicephalus
turanicus and Hyalomma anatolicum excavatum (ticks) and seven
The research aims to know the impact of workers values on their performance which is reflected on increasing productivity and improving its quality as well as the organization's progress and success. Application of this research took place in the General Company Of Electrical Industries; it contained four main pillars; the first involved research methodology، regarding the problem، importance، aim، basic theory، and method of data collection، the second is dedicated to the theoretical framework related to the research basic variables (values and workgroups) the third is assigned to analyze the actual data by using number of statistical methods، such as mathematical medium and standard deviation and also spearman rank
... Show MoreThe research tackles the nature of relationship between the Orthodox Church and the state in the Russian Federation. At the beginning of the nineties of the last century, the church had been performed a different role in its relationship with the state, and it had an effect over the internal and foreign policies for the Russian Federation. In political history of Russia, the church’s existence became an evident too much in comparing with the previous historical period, starting with the educational and political system, whether through a symbolic participating roles as what happened in the inauguration ceremony to take over responsibility of the head of state or taking actual roles such as influencing on the process of holding elections d
... Show MoreThe internationalization of the Libyan crisis and its accompanying militarization of the conflict have played a vital role in hindering to reach a comprehensive political settlement solution in Libya. The increasing international greediness in the Libyan energy resources and the geopolitical importance of the Libyan State led to the involvement of many international and regional powers in this crisis and transformed the Libyan crisis into “proxy war”. Moreover, the Turkish direct military intervention in the Libyan crisis is considered as one of the main constraints facing the international and regional efforts to settle the Libyan crisis as a result of the Turkish insistence on its military existence in Libya to preserve i
... Show MoreBackground: Health professionals have a crucial role in promotion, support and management of breastfeeding. To be effective in this effort, the clinician should focus on the issue from the preconception stage through pregnancy and delivery, and continue in subsequent infant care. Aim of the study: to assess the effectiveness of the UNICEF/WHO 40-hour of breast feeding training through the assess breastfeeding knowledge and attitudes of the health profession staff before and after training course.