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Experimental evaluation of thermal efficiency, electrical efficiency, and power production of low-concentrating photovoltaic-thermal system with micro-jet channel
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The efficient behavior of a low-concentrating photovoltaic-thermal system with a micro-jet channel (LCPV/T-JET) and booster mirror reflector is experimentally evaluated here. Micro-jets promote the thermal management of PV solar cells by implementing jet water as active cooling, which is still in the early stages of development. The booster mirror reflector concentrates solar irradiance into solar cells and improves the thermal, electrical, and combined efficiencies of the LCPV/T-JET system. The LCPV/T-JET system was tested under ambient weather conditions in the city of Bangi, Selangor, Malaysia, and all data was recorded between 10:00 a.m. and 4:00 p.m. Parametric studies were conducted to compare the performance of the LCPV/T-JET system to that of a conventional PV module. It is found that the short-circuit current of a standard PV module could be increased by 28% and 11.7%, with and without the use of jet water and booster mirror reflectors, respectively. Moreover, the power supplied by the PV component increases to 31% and 16%, respectively, with and without jet water and a booster mirror reflector. The characteristic curves for current–voltage and power–voltage curves also confirmed the superior thermoelectric properties of the LCPV/T-JET system. The measurements reveal a drop in the electrical efficiency of solar cells from 14.5% to 12.25% as the temperature of the cells increases from 32.5 °C to 66.5 °C between 10:00 a.m. and 1:00 p.m. Meanwhile, the thermal and overall efficiencies declined from 84% to 81.5% and 96% to 93%, respectively.

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Publication Date
Thu Jun 30 2022
Journal Name
Iraq Journal Of Market Research And Consumer Protection
COMPARISON BETEEEN THE CONSUMPTION OF RED MEAT AND WHITE MEAT FOR ASAMPLE OF CITIZENS OF THE CITY OF BAGHDAD/ AN EXPLORATORY STUDY
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Three hundred Iraqi people participated in demographic and attitudes study about red and white meat consumption. The mean age of the participants was 50 SD ± 11 years (mean 30-72); 51% were females and 49% males, mostly in forties who lived ≥ 5 years in Baghdad. The results showed that 80% of individuals prefer red meat. A 90% of people prefer fresh meat compared to frozen and processed meat. A 60% of people buy meat from popular markets. Nearly 87% of respondents believe the improving of livestock sector is essential and 80% of people confirmed there are obstacles to development this sector. An 80% of participates thought the reasons of the high prices of local fresh meat is the lack of planning and support to livestock sector. A survey

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Publication Date
Mon Feb 28 2022
Journal Name
Journal Of Educational And Psychological Researches
The Effect of Using the Strategy of Roundhouse in the Achievement of Fourth Grade Students of Computer and Their Attitudes towards It
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The research aims to identify the effect of using the strategy of Roundhouse on the achievement of fourth-grade students of computer and their Attitudes towards it. The research sample consisted of (61) fourth-grade secondary school students distributed into the experimental group consisted of (31) students study computer according to the Roundhouse strategy, and the control group consisted of (30) students follow the traditional method. The researcher designed an achievement test consisting of (30) items of multiple choice. To measure the attitudes of students towards the computer, a questionnaire of (32) paragraphs with three alternatives was designed by the researcher. The results showed that there is a statistically significant diffe

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Publication Date
Tue Jan 01 2019
Journal Name
Opcion, Año
The effect of the -Zahorik- model on acquiring grammatical concepts among students of the College of Administration and Economics/University of Baghdad
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Publication Date
Sat Oct 01 2022
Journal Name
Al–bahith Al–a'alami
NEGOTIATION SKILLS OF THE EMPLOYEES OF PUBLIC RELATIONS IN THE GOVERNMENT INSTITUTIONS : (Ministry of Electricity and Ministry of Transportation as a Model)
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This research dealt with the subject of negotiation skills of employees in public relations departments which is one of many skills supposed to be available to these employees. These skills combined help in the success of the job of public relations departments; and give them an important and vital role within the roles distributed in the departments of any government institution wither is governmental or non-governmental.

Negotiation is a skill that requires intelligence, tact, culture, information, intuition, and knowing to use the means of communication to access the information that is useful in reaching satisfactory results

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Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of organizational stress on the Performance of professor at the Faculty of Economics and Commercial Sciences / University of Djelfa / Algeria
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The present study aims at identifying the effect of organizational pressure with its aspects (management, work team, nature and conditions of work, external environment) on job performance in all its dimensions (commitment and effort made, capabilities and the rapidity of performance, motivation and job satisfaction, work environment) for the university teacher at the Faculty of Economics, Commercial and Management Sciences at the University of Djelfa, Algeria.

     In this research, the descriptive analytical approach is used. Data was collected through the distribution of a questionnaire to a sample that included 130 permanent teachers before being analyzed using the (SPSS) statisti

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Publication Date
Sun Dec 06 2015
Journal Name
Baghdad Science Journal
Efficacy of some local isolates of Beauveria bassiana(Bals.) and Metarhizium anisopliae (Met.) in control of mosquito larvae of Culex quinquefasciatus (Say)
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The main aim of this study is to investigate the ability of four local entomopathogenic isolates Beauveria bassiana (Bals.) and Metarhizium anisopliae (Met.) to control the mosquito larvae in the lab. The results revealed that the isolate (MARD48) B .bassiana reduced the survival rate of the mosquito larvae to (80%) followed by the isolate M. anisopliae (MARD10) to (90%) in the first two days of treatment, and 60 and 66% respectively in the third day. The results also showed that the isolate B. bassiana (MARD48) killed 50% of the population (LC50) with the concentration 1×104 conidia/ml compared to 1×107 conidia/ml for the isolates B. bassiana (MARD14) and M. anisopliae (MARD10), and 1×108 conidia/ml for the isolate B .bassiana (MARD76).

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Publication Date
Sun Aug 06 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effects of Rustamiyah treatment plant effluent on concentration of some heavy metals in water and sediment of Diyala river
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      Concentrations  of  four  heavy  metals, Zinc , Copper , Lead  and  Cadimium  were  determed  in  water  and  sediment  samples   collected bi-weekly  from  six  sampling sites  on  the  lower  part  of  River  Diyala    during  low  flow  period  (August  to  October)  and   high  flow  period  (April  to  June). A  reference  point site (1)  was  situated   upstream the  effects  of  the  effluent. Present  work  describes  the  e

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Publication Date
Mon Jul 01 1996
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
THE EFFECT OF DIFFERENT LEVELS OF NEMATODE POPULATION DENSITIES ON SEED GERMINATION PERCENTAGE AND SEEDLING CHARACTERISTICS OF SEVERAL CROPS
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Labrotary experiment was conducted to study the effect of different levels of nematode population densities of Meloidogyne spp on seed germination percentage and seedling characteristics of Vigna sinensis, Ahelmoschus esculentus, Cicer arietinum, Helianthus annuus and Rap-hanus sativus. Four different levels of nematode populat-ion densities ranged from 1 to 4 prepared from radish in-fected roots and used as inoculating agent to infect all seed types in the experiment Seed germination percentage of Vigna sinensis and Ablemoschus eseulentus were highly reduced (at 0.01 level of significance) with increased nematode population level from 1 to 4. Seedling length of the remaining seed types were significantly reduced (at 0.01 level of signif

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Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of estimation methods for regression model parametersIn the case of the problem of linear multiplicity and abnormal values
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 A simulation study is used to examine the robustness of some estimators on a multiple linear regression model with problems of multicollinearity and non-normal errors, the Ordinary least Squares (LS) ,Ridge Regression, Ridge Least Absolute Value (RLAV), Weighted Ridge (WRID), MM and a robust ridge regression estimator MM estimator, which denoted as RMM this is the modification of the Ridge regression by incorporating robust MM estimator . finialy, we show that RMM is the best among the other estimators

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Publication Date
Sat Oct 01 2011
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of etchant type and the use of silane on the shear bond strength of composite resin to porcelain
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Background: This study was formulated to compare the effect of 5%hydrofluoric acid in comparison to 37%phosphoric acid with and without the application of silane on bond strength of composite to porcelain. Materials and Methods: Specimen preparation was divided in to two phases, metal-disks fabrication (8mm-diameter and 4mm-thickness) and ceramic veneering. Thirty two specimens were prepared, sandblasted with 50 μm aluminum oxide, and divided into four groups of eight samples. Groups I and III were etched with 37%phosphoric acid while groups II and IV were etched with 5%hydrofluoric acid; and groups I and II were silaneted while groups III and IV were not. Heliobond, and resin composite were applied to each specimen using a plastic transpa

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