This article deals with the impact of including transverse ribs within the absorber tube of the concentrated linear Fresnel collector (CLFRC) system with a secondary compound parabolic collector (CPC) on thermal and flow performance coefficients. The enhancement rates of heat transfer due to varying governing parameters were compared and analyzed parametrically at Reynolds numbers in the range 5,000–13,000, employing water as the heat transfer fluid. Simulations were performed to solve the governing equations using the finite volume method (FVM) under various boundary conditions. For all Reynolds numbers, the average Nusselt number in the circular tube in the CLFRC system with ribs was found to be larger than that of the plain absorber tube. Also, the inclusion of transverse ribs inside the absorber tube increases the average Nusselt number by approximately 115% at Re = 5,000 and 175% at Re = 13,000. For all Reynolds numbers, the skin friction coefficient of the circular tube with ribs in the CLFRC system is larger than that of the plain absorber tube. The coefficient of surface friction reduces as the Reynolds number increases. The performance assessment criterion was found to vary between 1.8 and 1.9 as the Reynolds number increases.
The Plerion nebula is characterized by its pulsar that fills the center of the supernova remnant with radio and X-ray frequencies. In our galaxy there are nine naked plerionic systems known, of which the Crab Nebula is the best-known example. It has been studied this instance in order to investigate how the pulsar energy affect on the distribution and evolution of the remnant as well as study the pulsar kick velocity and its influence on the remnant. From the obtained results it's found that, the pulsar of the Crab Nebula injects about (2−3)𝑥 1047 erg of energy to the remnant, although this energy is small compared to the supernova explosion energy which is about 1051 erg but still plays a significant role in the distribution and the m
... Show MoreThe current research aims at identifying the new marketing directions that in the picture because if the changes and challenges that face the business nowadays, these effect on the future of the new product.
The problem of the research concentrate on the new marketing activities and how to make it appropriate between the product and the market's need, and to fulfill the needs and desire of the customer and it's importance for achieving the economical goals of the organization for a long relationship with the customer.
The resume of the research is about the impact of nowadays marketing and it's effect on knowing the customer instead of concentrating on the important roll of mark
... Show MoreThis study was conducted to identify the impact of germination in the ratio Almaah of Chemical Constituents of Homs and in the organoleptic properties of the Biskt plant it and compare the results with the treatment control (seeds Almnepth) Adhrt results for a significant increase in the percentage of crude protein with the progress of the process of germination, reaching 24.5% in percentage of crude protein with the progress of the germination process Krbu hydrate college during the germination period, reaching 59.2% in the fourth day
Maximizing the water productivity for any agricultural system is considered an adaptation to the potential climate change crisis. It is required, especially in arid and semi-arid environments in Iraq. Therefore, this study assessed the potential impact of climate change on the different environments in the Qadissiya and Nineveh provinces. The ensemble of six GCM models employed for the regional climate model of the HCLIM-ALADIN in high-resolution 10*10 km2 and Aqua-Crop was used to examine the response of water productivity and yield of winter wheat. With and without CO2 concentration changing under different water regimes in the near term (2020-2040
Medicinal plants are used to treat various diseases although little is known about their toxicity. Coriandrum sativum is one of the most commonly plants that is used to treat several physiological disorders. Thus, this study was conducted to evaluate the effect of aqueous extract of C. sativum on the structure and function of liver in male albino mice. Thirty male mice were randomly divided into three groups: Group 1 untreated (control), Group 2 and 3 were administrated orally with the aqueous extract of the plant at dose 125 and 250 mg/kg. b. w. For 30 days. The effect of the extract on liver weights, biochemical parameters as well as histological study were assessed. There were no significant difference (P>0.05) observed in relative organ
... Show MoreObjective: to assessthe impact of psychological and social climacteric changes on quality of life among
middle age women in Baghdad city
Methodology: : A descriptive analytic study was conducted to study the quality of life among middle age
women due topsychological and social climacteric changes from February 2013- July 2013. A purposive
sampleconsisted of three hundred (300) womenaged (40-65) years who were attending health centers in two
sectors in Baghdad / AL- Russafa andAL- karhk . The data were collected through using interview technique ,
and questionnaire format , which comprises two parts, first part consist (socio-demographic characteristic , the
second part quality of life domains (psychological and socia