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.
The surface finish of the machining part is the mostly important characteristics of products quality and its indispensable customers’ requirement. Taguchi robust parameters designs for optimizing for surface finish in turning of 7025 AL-Alloy using carbide cutting tool has been utilized in this paper. Three machining variables namely; the machining speeds (1600, 1900, and 2200) rpm, depth of cut (0.25, 0.50, 0.75) mm and the feed rates (0.12, 0.18, 0.24) mm/min utilized in the experiments. The other variables were considered as constants. The mean surface finish was utilized as a measuring of surface quality. The results clarified that increasing the speeds reduce the surface roughness, while it rises with increasing the depths and fee
... Show MoreWhen embankment is constructed on very soft soil, special construction methods are adopted. One of the techniques is a piled embankment. Piled (stone columns) embankments provide an economic and effective solution to the problem of constructing embankments over soft soils. This method can reduce settlements, construction time and cost. Stone columns provide an effective improvement method for soft soils under light structures such as rail or road embankments. The present work investigates the behavior of the embankment models resting on soft soil reinforced with stone columns. Model tests were performed with different spacing distances between stone columns and two lengths to diameter ratios of the stone columns, in addition to different
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This research seeks to test the influence of intellectual capital as an explanatory variable and its components (human capital, structural capital, relational capital) and sustainable competitive performance as a responsive variable and its components (reducing service delivery cycle time, rapid response to market demand, increasing customer satisfaction, providing better Quality of service, increasing market share)” through a field study, and here the research problem was diagnosed in an attempt to answer the following question: Is there awareness among the senior management within the private colle
... Show MoreThis study aims at identifying the extent of SMS usage and understanding the role it plays in satisfying users' needs and motivations. In order to achieve this aim, an analytical descriptive method was adopted by conducting a field survey among students at Petra University.
The study resulted in many conclusions, the most important of which is that using SMS meets the students' cognitive, social and communicational needs and desires, the highest being communicating with friends at 75%, followed by exchanging songs and videos at 52%, as well as exchanging photos at 45%. In regards to their motivation for using text messaging, forgetting daily problems scored highest at 81.4% and spending free time followed at 77.4%. This proves th
... Show MoreThis study was investigated the role of garlic extracts on the reproductive functions, via the development of immature male mice (25 days old) un l puberty. Immature male mice were divided into 3 groups (n=25). Group 1 "control" was daily administrated with tap water. Group 2 was daily administrated with cold aqueous garlic extract. Group 3 was daily administrated with hot aqueous garlic extract. Each group was randomly consisted of 5 subgroups (n=5/ subgroup) and administrated for different periods i.e, 1, 2, 3, 4 and 5 weeks respectively. Animals were scarified after 24 h from last treatment. Our findings elucidated that, cold and hot aqueous garlic extracts, when administrated at 25 days old (Immature period) have different impact dep
... Show MoreThe gas-lift method is crucial for maintaining oil production, particularly from an established field when the natural energy of the reservoirs is depleted. To maximize oil production, a major field's gas injection rate must be distributed as efficiently as possible across its gas-lift network system. Common gas-lift optimization techniques may lose their effectiveness and become unable to replicate the gas-lift optimum in a large network system due to problems with multi-objective, multi-constrained & restricted gas injection rate distribution. The main objective of the research is to determine the possibility of using the genetic algorithm (GA) technique to achieve the optimum distribution for the continuous gas-lift injectio
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