The fall angle of sun rays on the surface of a photovoltaic PV panel and its temperature is negatively affecting the panel electrical energy produced and efficiency. The fall angle problem was commonly solved by using a dual-axis solar tracker that continually maintains the panel orthogonally positioning to the sun rays all day long. This leads to maximum absorption for solar radiation necessary to produce maximum amount of energy and maintain high level of electrical efficiency. To solve the PV panel temperature problem, a Water-Flow Double Glazing WFDG technique has been introduced as a new cooling tool to reduce the panel temperature. In this paper, an integration design of the water glazing system with a dual-axis tracker has been accomplished and experimentally tested in order to enhance the PV panel efficiency, especially at hot climates. The proposed glazing system can simultaneously perform two functions, firstly, working as a cooling tool for reducing the stored heat in the PV panel during its work and secondly as an optical filter for sun light spectrum. Optimum design factors with their levels for the glazing system were calculated according to Taguchi method. Test experiments were carried out in Baghdad city on the 20th and 21st July 2016 on the tracker with and without using the WFDG system. The obtained results show that, the PV panel temperature with using the WFDG system was significantly dropped by 44% and its efficiency increased maximally by 36.6% at solar irradiance of 1213W/m2 as compared with conventional one.
SKF Sami I. Jafar, Mohammad J. Kadhim, Engineering and Technology Journal, 2018 - Cited by 4
Undesirable growth of potato (Solanum tuberosum L.) crop under an excessive N fertilizer application is the main obstacle presently. This research was conducted to investigate the response of different potato cultivars; Russet Burbank, Shepody, and Superior, and its qualitative characteristics under a series of N rates. Six rates of N fertilization (0–280 kg ha−1) were applied on 11 sites in a randomized complete block design, with four replications. Sites with ≥30 g kg−1 of soil organic matter (OM) produced total tuber yield, marketable yield, and tuber weight per plant 39.5, 45.2, and 54.9%, respectively, higher than sites with ≤30 g kg−1 of OM. Tubers specific gravity increased by 0.18% in the sites with ≥30 g kg−1 of OM.
... Show MoreThe frenzy caused by the horrific news on the TVs and the social media about COVID19 brings to the forefront the catastrophic epidemics in the past that led to mass deaths and haunt the imagination of historians and public alike. Works of fiction often depict the disastrous consequences of these epidemics, both real and imagined, focusing on the gothic experience the characters endure and their struggle to survive the disasters. This article explores this major issue in a contemporary novel, Laurie Halse Anderson’s Fever 1793 (2000). It chronicles the journey of the female protagonist and her struggle to survive and achieve autonomy during the historical yellow fever that hit Philadelphia more than two centuries ago, which stuck to the me
... Show MoreIn this research two series of the new derivatives of Trimethoprim and paracetamol drugs have been prepared which known as a high medicinal effectiveness. Series (A) is including the interaction of diazonium salt of trimethoprim and coupling with some substituted phenol compounds (2-amino phenol, 3-ethyl phenol, 1-naphthol, 2-nitro phenol, Salbutamol). Series (B) is including the interaction coupling alkali solution of paracetamol with diazonium salt of some substituted aniline compounds (Benzedine, 2, 3-di chloro aniline, Trimethoprim, Anilinium chloride, 2-nitro- 4-chloro aniline).Chemical structures of all synthesized compounds were confirmed by UV-visible and FTIR spectroscopy.
The current research aims to identify the level of digital skills of kindergarten teachers, identify the level of professional competence of kindergarten teachers, as well as to identify the relationship between digital skills and the professional competence of kindergarten teachers. The current research was determined by kindergarten teachers in the second Baghdad / Karkh Education Directorate for the academic year (2021-2022). The research sample consisted of (100) teachers chosen in a simple random way. To achieve the objectives of the research, the researcher developed a digital skills scale of (20) items and a scale of professional competence consisting of (22) items. The results revealed that kindergarten teachers have a high level
... Show MoreThe micronucleated erythrocytes in fish was used to detect water pollution by genotoxic agents. Fish belonging to different species were collected from three regions from Baghdad during three months (December/2000,January and February/2001 ).The micronucleated erythrocytes was observed in all the specimens. It was concluded that the genotoxic activity' in one region was less than in die other two regions.?
The crude aqueous extract of menthespicata , the objective of this study was to investigate the effects of this extraction , on the histological changes of the ovares and levels of sex hormone , ( FSH , LH , Estradiol ) in albino female mice . the extract was given orally for( 45 ) days . fourty mature female mice were used in this study , the animals divided into four major groups . each group was include ten mice . the first three groups was given different concentration )) (21 , 14 , 7 %) . While the fourth group considered as control group which had been administrated tab water . For ( 45 ) days each group had been killed for hormonal assay in blood
... Show MoreThis study aimed to identify the alterations of liver in the quail (Coturnix coturnix) exposed by nanosilver particles.45 quail (females) were collected from agriculture research center in Abu-Ghraib, divided into (6) groups including: T1(12 quails were exposed to 4ppm), T2 (12 quails were exposed to 8ppm) and T3 (12 quails were exposed to 12ppm) of silver nanoparticles solution for 60 days. As well as three groups for control (3 females for each). Birds were dissected to isolate livers for histological preperations after fixation with Bouin's fluid, Routine stains Hematoxyline and eosin were used. Histological study showed that the structure of liver in a control groups consist of hepatocytes arranged radially cords around the central vein
... Show MoreBackground: Conventional MR imaging is essential for diagnosis and evaluation of the posterior fossa tumors Objectives: To assess the value of diffusion weighted imaging and apparent diffusion coefficient in making distinction between different histological types of posterior fossa tumors.
Type of the study: Cross-sectional study.
Methods: Brain MRI and DWI assessed 19 patients (12 female and 7 male) with MRI diagnosis of posterior fossa tumors. absolute ADC values of contrast -enhancing solid tumor region and ADC ratio of solid tumor to ADC of normal -appearing deep White matter were compared with histological diagnosis postoperatively .The m
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