In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation conditions was examined. The variation of angles of attack and wind velocity leads to different values of vortex loading coefficients and shedding frequencies. The relation between the dynamic characteristics and solar collector performance was evaluated. The finite element method was used to estimate the dynamic characteristic of the solar collector in addition to experimental work to evaluate the relation between the dynamic behavior of the collector and its performance.
Objective: determine the effectiveness of an education program on youth's level of awareness towards
household waste control.
Methodology: A Quazi-experimental study was conducted. Non-probability (quota sample) of (80) young
persons is selected from Baghdad Governorate. They are divided into two equal groups of (40) subjects for the
study group which is exposed to the household waste control educational program. The remaining is the
control group which is not exposed to the educational program.
Results: The findings of the study indicated that youth of the study group have got benefits from the
implementation of the educational program towards household waste control and change has occurred to
their awareness tow
This study was conducted in the Poultry farm of the animal during the Production department, Iraqi during the (Ministry of Science and Technology) period from 3-9-2001 to 8-4-2002. The objectives of this study were to evaluate the effect of low – level chronic aflatoxicosis on performance (body weight, feed conversion efficiency and mortality), Serum biochemistry and activity of some enzymes (GOT,GPT, ALKP, LDH). A total of 300 male chicks of broiler breeder (Faw–Bro) were used. Chicks at day 1 of age were fed diets contaminated with aflatoxine at levels of 0, 0.3, 0.6, 0.9, 1.2, and 1.5 the feeding period were extended to 8 weeks. The data were subjected to analysis of variance by the completely randomized design. The results showed
... Show MoreIn the recent years, some of the newly constructed asphalt concrete pavements in Baghdad as well as other cities across Iraq showed premature failures with consequential negative impact on both roadway safety and economy. Frequently, load associated mode of failure (rutting and fatigue) as well as, occasionally, moisture damage in some poorly drained sections are the main failure types found in those newly constructed road.
In this research, hydrated lime was introduced into asphalt concrete mixtures of wearing course in two methods. The first one was the addition of dry lime on dry aggregate and the second one was the addition of dry lime on saturated surface dry aggregate moisturized by 2.0 to 3.0 percent of wa
... Show MoreAbstract
The research aims to determine the impact of the strategy performance evaluation and of the Standards (leadership, people, knowledge, processes, financial) in the achievement of organizational effectiveness in accordance with the dimensions (planning and setting goals, Exploitation of the Environment, achieve the goals, the ability to adapt, information management and communications) and the relationship between them, the problem of the research in the growing interest in the process of performance evaluation for organizations, the erroneous belief that the performance evaluation activity is useful, and the fact that performance evaluation process is one of the main tasks of the work of the Office of the Inspecto
... Show MoreThe research problem can be summarized through focusing on the environment that surrounds students and class congestion, how these factors affect directly or indirectly the academic achievement of students, how these factors affect understanding the scientific material that the student receives in this physical environment, how classroom’s components such as seats, space With which the student can move, the number of students in the same class, the lighting, whether natural or artificial, and is this lighting sufficient or not enough, the nature of the wall paint old or modern, is it comfortable for sight, the blackboard if it is Good or exhausted, In addition to air-conditioning sets in summer and winter, this is on the on
... Show MoreS Ali…, Journal of Physical Education, 2019 - Cited by 1
Abstract:
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 MoreTwisted tape insertion in smooth plain tube is one of types of passive methods that is used to enhance heat transfer. Swirl fluid flow inside tube and related heat transfer characteristics are very complex. ANSYS FLUENT (V 16.1) and ASPEN industrial program are used in analyzing this technique for enhancement heat transfer. A circular plain tube has length L=8534mm and 17 mm inner diameter with twisted tape has twist ratio of y = (H/D) = (150/17) =8.8 along with a plain tube were considered for this study. Eight Reynolds numbers (Re) of 784, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 are used to analyze the response of thermal performance. Crude oil API 28 exit temperature, film heat transfer coefficient, Nusselt number
... Show MoreTwisted tape insertion in the smooth plain tube is one of the types of passive methods that are used to enhance heat transfer. Swirl fluid flow inside the tube and related heat transfer characteristics are very complex. ANSYS FLUENT (V 16.1) and ASPEN industrial program are used in analyzing this technique for enhancement heat transfer. A circular plain tube has length L=8534mm and 17 mm inner diameter with a twisted tape of twist ratio of y = (H/D) = (150/17) =8.8 along the plain tube were considered for this study. Eight Reynolds numbers (Re) of 784, 1000, 2000, 3000, 4000, 5000, 6000 and 7000 are used to analyze the response of thermal performance. Crude oil API 28 exit temperature, film heat transfer coefficient, Nus
... Show More