A numerical computation for determination transmission coefficient and resonant tunneling energies of multibarriers heterostructure has been investigated. Also, we have considered GaN/Al0.3Ga0.7N superlattice system to estimate the probability of resonance at specific energy values, which are less than the potential barrier height. The transmission coefficient is determined by using the transfer matrix method and accordingly the resonant energies are obtained from the T(E) relation. The effects of both well width and number of barriers (N) are observed and discussed. The numbers of resonant tunneling peaks are generally increasing and they become sharper with the increasing of N. The resonant tunneling levels are shifted inside the well by increasing the well width and vice versa. These features and the transmission coefficient as a function of incident energetic particles play an important role in fabrication of high speed devices and a good factor for determination the peak-to-valley ratio of resonant tunneling devices respectively.
The importance of the research lies in preparing exercises using a proposed device to learn the skill of thehuman wheel on a machine rug of ground movements of the artistic gymnastics. As for the research problem:Through the presence of the two researchers as teachers and observers of this sport in the gymnastics hall,they noticed that there is difficulty in the students’ performance of the skill of the round off on the machineof the mat of ground movements, according to the researchers’ opinion, the reason for this is that skillsare taught with the limited availability of assistive devices, as well as the lack of use of these devices inexercises according to biomechanical variables, although they facilitate the learning process
... Show MoreThe topic of the research tagged (narrative structure and its impact on building open and closed endings in the fictional film) is summarized by studying the mechanism of employing closed and open endings in the fictional film. novelist, then the need for it, as well as the objectives of the research and clarifying its limits as well as its importance. Then moving to the theoretical framework, which included three topics, where the first topic was entitled (the cinematic construction of the film narrative), either the second topic (the structure of complexity and narrative solutions), or the third topic dealt with the subject (the structure of the end and its relationship to the construction of the narrative). After completing the theore
... Show MoreTh paper scientifically deals with the Syrian crisis events erupted in 2011 using the historical descriptive and analytical approaches. The importance of the paper comes from the serious crisis that occurred in a region rich of historical crises, and natural resources attracting the attention of the major countries. The paper aims to show the Syrian crisis, its importance to Russia, the United States, and the regional countries, its impact on Russia economically and politically after the intervention, and Russia’s achievements on a global level holding the influential power on international decisions and other global events. The new Russian strategy has proven its worth in preserving its strategic interests as it could help the Syrian
... Show MoreThe demand for expatriate labor to Iraq increased after 2003 as a result of the openness that Iraq experienced, but this expatriate labor, which was requested at an increasing rate, has had economic, social, and political effects on the Iraqi economy in general, and the Iraqi labor market in particular. This is due to the high rates of unemployment, as most of these expatriate workers cause competition to local labor, and thus cause repercussions on the Iraqi economy as a whole, except for those expatriate workers coming with companies working in the oil sector. Iraq's GDP
This study was aimed to determine the impact of Conocarpus erectus L. compost fertilizer, and some micronutrients on growth and production of potato. This research was conducted at one of the fields of the College of Agricultural Engineering Sciences - University of Baghdad. The experiment was implemented using factorial arrangement (4X3X3) within randomized complete block design with three replicates. Conocarpus fertilizer was represented the first factor with three levels (7.5, 15, 30 ton.ha-1), which symbolized (C2, C3, C4). Chemical fertilizer as recommended dose as a control, which symbolized (C1). The second factor was foliar spraying with three levels of iron (0, 100, 200 mg.L-1), which symbolized (F0, F1, F2). The third fact
... Show MoreThe development taking place in various sports in performance, which was and still takes a large part by focusing on the specialized level of the players, whether in training or competition in all sports, including handball. In the competition (the match) by measuring the hormone beta-endorphin as well as. To identify the changes that occur in some biochemical variables as a result of the high effort in the competition (the match) by measuring lactic acid and the hormone aldosterone). The researcher used the descriptive method, the pre and post test of one group Due to the nature of the research, the research community was represented by Al-Shorta Sports players and Al-Jaish club players in handball, as they numbered (24) players from the t
... Show MoreTo investigate the effect of spraying some plant extraction and anti-oxidants on growth and yield of two cultivars of sunflower, a field experiment was conducted during fall season of 2009 and spring season of 2010 at the Experimental Farm, Department of Field Crop Science, College of Agriculture/ University of Baghdad. RCBD with three replications as factorial at two factors was used. First factor was cultivars Akmar and Shmoss, second was spraying with extraction of karkade at 25%, liquorices at 50%, vitamin C at concentration 1.5 mg.l-1 and nutrient which content 15 elements at concentration 15 % in addition to control treatment which sprayed with distilled water only. The result showed no significant differences between the two cultivar
... Show MoreThe field experiment was conducted in garden of Department of Biology, College of Education for Pure Sciences (Ibn- Al-Haitham), University of Baghdad during the season of growth (2014-2015). The experiment aimed to study the effect of citric acid with two concentration 10, 20 mg. L-1 and glutamic acid with two concentration 50, 100 mg. L-1 on growth and yield of broad bean (Vicia faba). The results were showed an increased in plant height, leaves number. Plant dry weight, chlorophyll content flowers number, absolute growth rate, crop growth rate, legume length and dry weight, legumes number, seed dry weight compared with control plants.