There have been many advances in the solar chimney power plant since 1930 and the first pilot work was built in Spain (Manzanares) that produced 50 KW. The solar chimney power plant is considered of a clean power generation that needs to be investigated to enhance the performance by studying the effect of changing the area of passage of air to enhance the velocity towards the chimney to maximize design velocity. In this experimental and numerical study, the reduction area of solar collector was investigated. The reduction area that mean changing the height of glass cover from the absorbing plate (h1=3.8cm, h2=2.6cm and h3=1.28cm). The numerical study was performed using ANSYS Fluent software package (version 14.0) to solve governing equations. The aim of this work was to study the effect of change the height of reduction area to the design velocity (velocity move the blade of turbine at inlet in the chimney). The results showed that the third height (h3=1.28cm) gives the best result because when decreasing the height between the glass cover and absorbing plate, the area between them decreased and the design velocity increased then the efficiency of solar chimney model was increased.
Environmental risk growing Become challenge "and a matter of controversy and concern to many of those concerned with environment, social, economic, and the same happens with the administrative rather than in isolation for this movement, as the issues of climate change Disturbed and troubled him, especially after what caused the risk of destruction, and irresponsibility , chaos, and the futility of resources, crops, fields, nature and homes and reactors, and after what happened in Japan from the scourge of "Hurricane tsunami " and earthquakes successive accompanied him and what became of him by surprise catastrophic affected the economy and the univ
... Show MoreTotal Quality Assurance Concept have appeared in Higher Education Institutions as a result of the continuous criticism for the lower quality of the outputs of these institutions and their inappropriacy to the needs of the job market. The faculty, i.e. teaching staff member, is one of the most important output for his/her responsibility to achieve the stated goals in higher education. This represents a problem that may influence the construction of society which has to limit his tasks, responsibilities, and competencies that should be found in a faculty, and evaluating his teaching profession in light of the prerequisites of the century to become an input to achieve quality assurance in Higher Education. Therefore, the present study aims
... Show MoreThe results of theoretical and experimental investigations carried out to study the effect of load and relative sliding speed on the abrasive wear behavior in drilling bit teeth surfaces of an insert tungsten carbide bit have been presented. Experimentally, an apparatus for abrasive wear tests conducted on the modified ASTM-G65 was modified and fabricated to facilitate loading and measurement of wear rate for the sand/ steel wheel abrasion test, which involves two cases of contact; first is at dry sand and second is under wet condition. These tests have been carried under varied operating parameters of normal load and sliding speed. A theoretical model based upon the Archard equation has been developed for predicting wear simulation by u
... Show MoreThe Messengers and the Imam of the God-fearing, Muhammad is God, his family, and all of his companions. As for what comes after... Fainting is one of the involuntary symptoms and states that occur to a person when carrying out his life’s tasks suddenly due to his loss of sense and movement, so he loses consciousness for a period of time that is short or may be long, and the person is held accountable and responsible for every moment of his life. He is required to perform duties specified by Sharia law, such as prayer, fasting, and Hajj...and fainting prevents him from performing these actions. We must consider the opinions of jurists and know the legal implications resulting from it. It was said that a person has a capacity that enable
... Show MoreThis study aims to identify the level of quality of Islamic banking services in the Kingdom of Saudi Arabia. It also investigates the importance of the various dimensions of the quality of banking services. The sample of the study included 69 clients of Al Rajhi Bank and Al-Bilad Bank. The study concluded that the overall level quality of services that Islamic banking offer is high. However, their relative importance varies from one dimension to another. The security, confidence and physical aspects are very high which this is a good point. On the other hand, the application aspects do not get the same importance. These aspects include the customer's wishes, helping them to improve the services offered to them,
... Show MoreThe research attempts to diagnose the level of the effect of human resources flexibility (employees skills flexibility, employees behaviors flexibility, and human resource practice flexibility) in the south al-rusafa directorate of a power station one of the formations and the Ministry of Electricity, and impact of a range of variables related to the performance operational, namely, (efficiency, effectiveness)recognizing the importance of the subjects studied,& because of the importance of expected results of the field under consideration,researcher selected a sample of size (121) engineers and technicians of workers in the directorate. Was my hypotheses the major search of a relationship and impact between human resources flex
... Show MoreThe study aimed at identifying the strategic gaps in the actual reality of the management of public organizations investigated to determine the strategy used based on the study model. The study relied on the variable of the general organization strategy in its dimensions (the general organization strategy, the organization's political strategy and the defense strategy of the organization) The sample of the study was (General Directorate of Traffic, Civil Status Directorate and Civil Defense Directorate), formations affiliated to the Ministry of the Interior, for the importance of the activity carried out by these public organizations by providing them In order to translate the answers into a quantitative expression in the analysi
... Show MoreBackground: Poly-ether-ether-ketone(PEEK) has been introduced to many dental fields. Recently it was tested as a retainer wire‎ following orthodontic treatment. This study aimed to investigate the effect of changing the bonding spot size and location on the performance of PEEK retainer wires. Methods: A biomechanical study involving four three-dimensional finite element models was performed. The basic model was with a 0.8 mm cylindrical cross-section PEEK wire, bonded at the center of the lingual surface of the mandibular incisors with 4 mm in diameter composite spots. Two other models were designed with 3 mm and 5 mm composite sizes. The last model was created with the composite bonding spot of the canine away from the center of t
... Show MoreBackground: Poly-ether-ether-ketone(PEEK) has been introduced to many dental fields. Recently it was tested as a retainer wire‎ following orthodontic treatment. This study aimed to investigate the effect of changing the bonding spot size and location on the performance of PEEK retainer wires. Methods: A biomechanical study involving four three-dimensional finite element models was performed. The basic model was with a 0.8 mm cylindrical cross-section PEEK wire, bonded at the center of the lingual surface of the mandibular incisors with 4 mm in diameter composite spots. Two other models were designed with 3 mm and 5 mm composite sizes. The last model was created with the composite bonding spot of the canine away from the center
... Show More