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Thermal performance of a flat-plate solar collector using aqueous colloidal dispersions of graphene nanoplatelets with different specific surface areas
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The effects of using aqueous nanofluids containing covalently functionalized graphene nanoplatelets with triethanolamine (TEA-GNPs) as novel working fluids on the thermal performance of a flat-plate solar collector (FPSC) have been investigated. Water-based nanofluids with weight concentrations of 0.025%, 0.05%, 0.075%, and 0.1% of TEA-GNPs with specific surface areas of 300, 500, and 750 m2/g were prepared. An experimental setup was designed and built and a simulation program using MATLAB was developed. Experimental tests were performed using inlet fluid temperatures of 30, 40, and 50 °C; flow rates of 0.6, 1.0, and 1.4 kg/min; and heat flux intensities of 600, 800, and 1000 W/m2. The FPSC’s efficiency increased as the flow rate and heat flux intensity increased, and decreased as inlet fluid temperature increased. When using nanofluids in the FPSC, the measured temperatures of absorber plate and tube wall decreased down to 3.35% and 3.51%, respectively, with the increase in weight concentration and specific surface area, while the efficiency increased up to 10.53% for 0.1- wt% TEA-GNPs nanofluid with specific surface area of 750 m2/g, in comparison with water. When using water as heat transfer fluid, very good agreement was obtained between the experimental and predicted values of absorber plate temperature, tube wall temperature, and collector’s efficiency with maximum differences of 3.02%, 3.19%, and 3.26%, respectively. While, when using nanofluids, higher differences were found, up to 4.74%, 4.7%, and 13.47% for TEA-GNPs nanofluid with specific surface area of 750 m2/g, respectively. Accordingly, the MATLAB code was capable of simulating the thermal performance of FPSCs utilizing nanofluids as their heat transfer fluids with acceptable accuracy. Values of performance index were all greater than 1, and increased as weight concentration increased up to 1.104 for 0.1- wt% TEA-GNPs nanofluid with specific surface area of 750 m2/g, implying higher positive effects on efficiency than negative effects on pressure drop. Accordingly, the investigated nanofluids can efficiently be used in FPSCs for enhanced energy efficiency, and the 0.1- wt% water-based TEA-GNPs nanofluid with specific surface area of 750 m2/g was comparatively the superior one.

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Publication Date
Sun Nov 01 2015
Journal Name
Engineering And Technology Journal
Synthesized Cu (In, Ga) Se2 (CIGS) thin films and implementation as the active light absorbing material in photovoltaic devices (PVs)
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This review article summarizes our research focused on Cu(In, Ga)Se2 (CIGS) nanocrystals, including their synthesis and implementation as the active light absorbing material in photovoltaic devices (PVs). CIGS thin films were prepared by arrested precipitation from molecular precursors consisting of CuCl, InCl3, GaCl3 and Se metal onto Mo/soda-lime glass (SLG) substrates. We have sought to use CIGS nanocrystals synthesized with the desired stoichiometry to deposit PV device layers without high temperature processing. This approach, using spray deposition of the CIGS light absorber layers, without high temperature selenization, has enabled up to 1.5 % power conversion efficiency under AM 1.5 solar illumination. The composition and morphology

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Publication Date
Fri Jun 12 2015
Journal Name
Chemistry And Materials Research
Synthesis, Physico-Chemical and Antimicrobial Activities Co(II),Ni (II) ,Cu(II), Zn(II),Cd(II) and Hg(II) MixedLigand Complexes of L- Alanine and Trimethoprim Antibiotic
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The Co (II), Ni (II) ,Cu(II), Zn(II) ,Cd(II) and Hg(II) complexes of mixed of amino acid (L-Alanine ) and Trimethoprim antibiotic were synthesized. The complexes were characterized using melting point, conductivity measurement and determination the percentage of the metal in the complexes by flame (AAS). Magnetic susceptibility, Spectroscopic Method [FT-IR and UV-Vis]. The general formula have been given for the prepared mixed ligand complexes [M(Ala)2(TMP)(H2O)] where L- alanine (abbreviated as (Ala ) = (C5H9NO2) deprotonated primary ligand, L- Alanine ion .= (C5H8NO2-) Trimethoprim (abbreviated as (TMP ) = C10H11N3O3S M(II) = Co (II),Ni(II) ,Cu(II), Zn(II) ,Cd(II) and Hg(II). The results showed that the deprotonated L- Alanine b

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Publication Date
Mon Dec 28 2020
Journal Name
Journal Of The College Of Education For Women
Penalty of Semi-Intentional Killing Offence according to the Egyptian and Algerian Penal Law: An Evaluative Study from the Islamic Viewpoint: محمد جبر السيد عبد الله جميل
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The study aims at  evaluating  the penalty of  semi- intentional killing felony in the Egyptian and Algerian criminal law following the Islamic Law (Shari'a). The  study used the descriptive, evalutive and analytical  methodology  to  reach the topic in question. To meet the theoretical significance of the study, much data has been collected to give a comprehensive picture about the topic under examination. As for the practical significance of the study, it helps the juridical power to reconsider and phrase the legal materials of the semi-intentional killing penalty based on the Islamic law. The study has come to the conclusions that the Islamic Law (Shari'a) imposes a compensation (blood-money) to be g

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Publication Date
Sat Mar 26 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The theory of convergent between standard and optimal cost supporting actual cost in an Enterprise: بحث تطبيقي في معمل الألبسة الرجالية في النجف للفترة من 2007-2020
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The research aims to achieve proof of convergence between optimal costs and standard costs in calculating costs for the economic unit, support efforts aimed at adopting optimal costs in cost accounts and accounting thought in general, and achieve benefit from the theory of convergence between optimal costs and standard costs in the field of achieving actual costs in The economic unit in order to reduce and converge, and this came to address the possibility of adopting the concept of optimal costs in the production costs calculations for the purposes of rationalizing administrative decisions, and rationalizing the preparation of financial statements within management accounting.

The research concluded that

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Publication Date
Tue May 01 2018
Journal Name
Journal Of Physics: Conference Series
Composition, Characterization and Antibacterial activity of Mn (II), Co (II), Ni (II), Cu (II) Zn (II) and Cd (II) mixed ligand complexes Schiff base derived from Trimethoprim
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. New Schiff base ligand 2-((4-amino-5-(3, 4, 5-trimethoxybenzyl) pyrimidin2-ylimino) (phenyl)methyl)benzoic acid] = [HL] was synthesized using microwave irradiation trimethoprim and 2-benzoyl benzoic acid. Mixed ligand complexes of Mn((ІІ), Co(ІІ), Ni(ІІ), Cu(ІІ), Zn(ІІ) and Cd(ІІ) are reacted in ethanol with Schiff base ligand [HL] and 8-hydroxyquinoline [HQ] then reacted with metal salts in ethanol as a solvent in (1:1:1) ratio. The ligand [HL] is characterized by FTIR, UV-Vis, melting point, elemental microanalysis (C.H.N), 1H-NMR, 13C-NMR, and mass spectra. The mixed ligand complexes are characterized by infrared spectra, electronic spectra, (C.H.N), melting point, atomic absorption, molar conductance and magnetic m

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Publication Date
Fri Apr 27 2012
Journal Name
Al-qadisiyah Journal For Science
Synthesis and Characterization of azo Compound 5-(2-Benzoic acid azo)-8-hydroxy quinoline as Bidentate Ligand and It’s Complexeswith Co (II), Ni (II) and Cu (II) .
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Coupling reaction of 2-amino benzoic acid with the 8-hydroxy quinoline gave the azo ligand (H2L): 5-(2-benzoic acid azo )-8-hydroxy quinoline.Treatment of this ligand with some metal ions (CoII, NiII and CuII ) in ethanolic medium with a (1:2) (M:L) ratio yielded a series of neutral complexes with general Formula[M(HL)2],where: M=Co(II), Ni(II) and Cu(II), HL=anion azo ligand (-1).The prepared complexes were characterized using flame atomic absorption,FT-IR and UV-Vis spectroscopic methods as well as magnetic susceptibility and conductivity measurements.

Publication Date
Tue Aug 03 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Measurement and accounting disclosure for small and medium-sized enterprises according to the International Financial Reporting Standard (SMEs) and its reflection on the fairness of financial statements.
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The research aims to identify small and medium enterprises in accounting thought in terms of definition and concept, and this international financial reporting standard for small and medium-sized enterprises (SMEs) in the theoretical aspect. As for the practical aspect, the small and medium-sized enterprises standard has been applied to the financial statements of the company in question, the preparation of the opening entry on the date of the transition, the requirements of measurement and the accounting disclosure on the date following the application of the standard, and the preparation of the company's financial statements and the accompanying explanations according to the standard of small and medium-sized enterprises. The r

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Publication Date
Fri Sep 24 2021
Journal Name
Journal Of The College Of Education For Women
Arabic Language Teachers’ Training Needs for Implementing Cognitive Trips Strategy when Teaching Arabic Language Courses in the Kingdom of Saudi Arabia: أمل ناصر الحربي, و وفاء العويضي
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The present work focuses on examining the strategy of cognitive trips and the Arabic language teachers’ training needs of such a strategy when teaching Arabic language courses in the Saudi Arabia Kingdom. To achieve the objective of the study, and check whether this strategy is used in lesson planning, lesson teaching, or lesson assessment, a descriptive approach and a questionnaire have been adopted. The researchers used a number of statistical tools, and chose a purposive sample, which consists of (58) Arabic language teachers from Saudi Arabia Kingdom. Results have shown that the training needs of Arabic language teachers for implemining the strategy of cognitive journeys while teaching Arabic language courses came in the following

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Publication Date
Sun Sep 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Investment portfolio risks of the insurance company and their impacts on profitability ratios: An applied research at the national insurance co. for the period 2004-2014
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The research is trying to identify the investment portfolio risks of the insurance company and their impact, on the Profitability ratios of the company, and whether the company's scientific methods followed in the measurement of these risks, and conducted research in the National Insurance Company. by relying on its annual budget as well as the annual reports, The search dealing with these data in theoretical and practical major premise to statistically significant between to investment portfolio risk and financial performance correlation and reach a set of conclusions and recommendations which are the following.                

investments include many ri

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Publication Date
Fri Jan 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
The Role of the Vegetative Part in Some Plant Species to Uptake and Accumulate Lead Element from Polluted Air (an Applied Study in Baghdad /Karkh in Iraq)
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The current study was conducted to test the efficiency of the vegetative part (plant leaves) of plant species of shrubs and trees involved in forming semi-artificial vegetation in the city of Baghdad, Karkh, in the uptake and accumulating the lead element that pollutes the air in the city atmosphere. Five plant sampling sites were selected: Al-Kadhimiyah, Al-Mansour, Al-Ma'aml (Al-Salam district), Al-Adl, and Al-Ameriya district intersections (Al-Seklat), and symbols were given (A, B, C, D, E) respectively. The spread and distribution of plants vary in terms of human activities and pollution levels, affecting the five sites that recorded more than 20 species. For a real comparison between plant efficiency and the effect of the nature of

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