Enhancement of the performance for hybrid solar air conditioning system was presented in this paper. The refrigerant temperature leaving the condenser was controlled using three-way valve, this valve was installed after the compressor to regulate refrigerant flow rate towards the solar system. A control system using data logger, sensors and computer was proposed to set the opening valve ratio. The function of control program using LabVIEW software is to obtain a minimum refrigerant temperature from the condenser outlet to enhance the overall COP of the unit by increasing the degree of subcooled refrigerant. A variable load electrical heater with coiled pipe was used instead of the solar collector and the storage tank to simulate the sola
... Show MoreTrials were carried out in the middle of Iraq ( 3 different sites ) during 2009 to detecation and determined the seasonal occurrence of Agriotes lineatus L. Three YATOR funnel traps were used in each of these sites which baited with the specific pheromone of A. lineatus from the first of March to the end of October in the College of Agriculture - Abu- Ghraib / Provenance of Baghdad and AL-Nile / Provenance of Babylon , while in AL-Radhwania was used through May- June. Pheromone dispenser were changed every 6 weeks in each of these traps . Males of A. lineatus were found in all of the three sites , and the total number capture were 208 , 897 and 57 male / 3 traps / season in College of Agriculture , AL-Nile and AL-Radhwania respectiv
... Show MoreThe study aimed to identify the perceptions of social studies teachers in the Governorate of Muscat about the importance of employing the skills of the twenty-first century in teaching. The study employed a qualitative approach. The two researchers used an analytical approach based on the Grounded Theory, the data was gathered through semi-structured interviews with (15) male and female teachers. The results indicated that social studies teachers relate the twenty-first-century skills more to improving students’ achievement level in the subject, while they see that these skills have less influence in developing students’ communication skills and cooperation with their peers. In light of the results of the study, the two researchers r
... Show MoreBackground: Relapse of previously moved teeth, is major clinical problem in orthodontics with respect to the goals of successful treatment. This study investigated the effect of orthodontic relapse on the proliferation of fibroblast and epithelial rests of Malassez cells in periodontal ligament of rat molars. Materials and Methods: Sixteen ten-week- old male Wister rats were randomly divided into four groups composed of four animals each: Group I received no orthodontic force (control). In both Group II and Group III, uniform standardized expansive springs were used for moving the maxillary first molars buccally for periods of one and three weeks respectively. The spring initially generated an average expansive force of 20 g on each side.
... Show MoreThis research was designed to study effect of performance appraisal dimensions on organizational confidence.
Asset completion questionnaire was used to collect data of this research from a random simple represent forty employees who works in Iraqi Oil ministry. The main result of this research was positive relations and the effect between performance appraisal and organizational confidence. The research contains some conclusions, the main of it is unimplemented the performance appraisal results in the policies of employees in the ministry and it work in classic methods incentives and training.
The important recommendations must doing to achieve integrating between the result of pe
... Show MoreIn this work, we studied the effect of power variation on inductively coupled plasma parameters using numerical simulation. Different values were used for input power (750 W-1500 W), gas temperature 300K, gas pressure (0.02torr), 5 tourns of the copper coil and the plasma was produced at radio frequency (RF) 13.56 MHZ on the coil above the quartz chamber. For the previous purpose, a computer simulation in two dimensions axisymmetric, based on finite element method, was implemented for argon plasma. Based on the results we were able to obtain plasma with a higher density, which was represented by obtaining the plasma parameters (electron density, electric potential, total power, number density of argon ions, el
... Show MoreChronic renal failure (CRF) affects thyroid function in multiple ways, including low circulating thyroid hormone concentration, altered peripheral hormone metabolism, disturbed binding to carrier proteins, possible reduction in tissue thyroid hormone content, and increased iodine store in thyroid glands.The target of study is to find a relationship between chronic renal failure and thyroid function.In addition, we tried to study the effect of CRF on serum creatinine dependent on the level of thyroid hormones (T3 and T4) and thyroid stimulating hormones(TSH). Forty patients with chronic renal failure (20 male, 20 female) were enrolled in this study in addition to forty healthy individual as control gro
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