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Experimental and Theoretical Study for Performance Enhancement of Air Solar Collectors by Using Different Absorbers
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An experimental and theoretical study has been done to investigate the thermal performance of different types of air solar collectors, In this work air solar collector with a dimensions of (120 cm x90 cm x12 cm) , was tested under climate condition of  Baghdad city with a (43° tilt angel)  by using  the absorber plate (1.45 mm thickness, 115 cm height x 84 cm width), which was manufactured from iron painted with a black matt.

The experimental test deals with five types of absorber:-

 Conventional smooth flat plate absorber , Finned absorber , Corrugated absorber plate, Iron wire mesh on absorber And matrix of porous media  on absorber .

The hourly and average efficiency of the collectors were investigated for three values of mass flow rates (0.016 kg/s to 0.027 kg/s) for each type of collector and then the porosity for the last collector type was tested by changing the porosity of porous media.

A typical air solar collector has been studied Theoretically to build a standard software for testing any type of air solar collectors with local weather data .

From the experimental study  it can be seen  by using some obstacle material to the air flow (fins, corrugated absorber plate, iron wire mesh porous media on the absorber) could be enhanced the efficiencies not less than 4 %  for  finned type and 8 % for corrugated and 25 % for mesh and 30  %  for porous media comparing with flat plate (smooth) collector .

Theoretically, the results showed that the collector with high convention heat transfer coefficient porous media has high  hourly efficiency about (η = 56 %) and iron wire mesh on absorber ( η = 52 % ), on the other  side the minimum  performance occurred in the  flat plate absorber  (η = 28  %).

Comparison of results reveals that the theoretical predictions agree reasonably well with experimental results. And the difference between the theoretical   and experimental efficiency in general was between (1─ 15 %).

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Publication Date
Tue Nov 01 2022
Journal Name
Optik
Design new D-π-A materials for sensitizers for dye-sensitized solar cells: Quantum chemical study
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Within this paper, we developed a new series of organic chromophores based on triphenyleamine (TPA) (AL1, AL-2, AL-11 and AL-22) by engineering the structure of the electron donor (D) unit via replacing a phenyle ring or inserting thiophene as a π-linkage. For the sake of scrutinizing the impact of the TPA donating ability and the spacer upon the photovoltaic, absorptional, energetic, and geometrical characteristic of these sensitizers, density functional theory (DFT) and time-dependent DFT (TD-DFT) have been utilized. According to structural characteristics, incorporating the acceptor, π-bridge and TPA does not result in a perfect coplanar conformation in AL-22. We computed EHOMO, ELUMO and bandgap (Eg) energies by performing frequency a

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Publication Date
Tue Dec 01 2015
Journal Name
Journal Of Economics And Administrative Sciences
Measuring Service Delivery Orientation For Doctor and patients Perspective Experimental Study in Numan General Hospital
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This research aims to Measurement provide the service from Two perspectives The first perspective Service Provider (doctors) and the second recipient of the service (patients) in Numan General Hospital, and represented the research problem in perceptions of medical staff in the hospital assigned to them responsibility by providing superior services satisfy customers, and how they maintained ready to assist customers and provide services that exceed their perceptions of these services through the use of the developer scale by (Frimpong and Wilson, 2012), includes orientation to provide the service scale four dimensions (Internal cooperative behaviors, service Competence, Service Responsiveness and Enhanced service) and includes do

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Publication Date
Fri Jan 20 2023
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
A Review Article: Green Synthesis by using Different Plants to preparation Oxide Nanoparticles
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Green nanotechnology is a thrilling and rising place of technology and generation that bracesthe ideas of inexperienced chemistry with ability advantages for sustainability, protection, andthe general protection from the race human. The inexperienced chemistry method introduces aproper technique for the production, processing, and alertness of much less dangerous chemicalsubstances to lessen threats to human fitness and the environment. The technique calls for inintensity expertise of the uncooked materials, particularly in phrases in their creation intonanomaterials and the resultant bioactivities that pose very few dangerous outcomes for peopleand the environment. In the twenty-first century, nanotechnology has become a systematic

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Publication Date
Tue Apr 24 2018
Journal Name
المجلة العلمية للتربية البدنية والرياضية - جامعة الإسكندرية مصر
وضع تدريبات بليومترية وفقا لبعض المؤشرات البيوميكانيكية والعضلية لتحسين أداء الركلة من علامة الجزاء في كرة القدم - اطروحة دكتوراه
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تتطلب كرة القدم الحديثة تطوير الصفات البدنية والمهارية للوصول باللاعب إلى لمستويات العليا، ولما كانت هذه الصفات مرتبطة مع بعضها البعض، فانها تتطلب ان يتم تطويرها معا في نفس الوقت دون تنمية كل صفة على حده، وإن توافر الحد الأدنى من الصفات البدنية كمتطلبات أساسية للأداء المهاري يعتبر الهدف الأساسي للتخطيط لأي برنامج تدريبي، وإن الصفات البدنية لها مفهوم شاسع وواسع الاستعمال في مجال البحوث الرياضية، وقد أعطيت ع

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Publication Date
Thu Dec 14 2023
Journal Name
Iete Journal Of Research
Performance Enhancement of VLC-NOMA Employing Beamforming Function based vehicle-to-multivehicle Communication system
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Publication Date
Fri Mar 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Balancing the Multi Assembly line Using Ranked Positional Weight and COMSOAL Algorithms: Case Study at the Sewing line Factory (7) /the General Company for Leather Industries (GCLI/ Baghdad)
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      The problem of multi assembly line balancing appears as one of the most prominent and complex type of problem. The research problem of this dissertation is concerned with choosing the suitable method that includes the nature of the processes of the multi assembly type of the sewing line at factory no. (7). The State Company for Leather Manufacturing. The sewing line currently suffers from idle times at work stations which resulted in low production levels that do not meet the production plans. The authors have devised a flexible simulation model which uses the uniform distribution to generate task time for each shoe type produced by the factory. The simulation of the multi assembly line was based on assigni

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Publication Date
Sat Apr 01 2017
Journal Name
Image & Video Processing
Enhancement of LBP-based face identification system by adopting preprocessing techniques
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Face Identification system is an active research area in these years. However, the accuracy and its dependency in real life systems are still questionable. Earlier research in face identification systems demonstrated that LBP based face recognition systems are preferred than others and give adequate accuracy. It is robust against illumination changes and considered as a high-speed algorithm. Performance metrics for such systems are calculated from time delay and accuracy. This paper introduces an improved face recognition system that is build using C++ programming language with the help of OpenCV library. Accuracy can be increased if a filter or combinations of filters are applied to the images. The accuracy increases from 95.5% (without ap

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Publication Date
Mon Oct 03 2022
Journal Name
Optik
Enhancement the photosensitivity of PVA NFs/Si prepared by electrospinning technique
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This work aimed PVA nanofibers in a range of concentrations were successfully manufactured via electrospinning. PVA NFs/Si was effectively prepared using the electrospinning process. The structural, morphological, optical and electrical properties of the prepared PVA were studied using XRD, FE-SEM, UV-Vis spectrophotometer and I-V characteristics, respectively. The amorphous structure of PVA nanofibers was observed. The optical energy gap from ultraviolet to visible was between (2.75 and 2.41) eV, making this compound highly sensitive to visible orange light at 610 nm, with a photosensitivity of 66%. The optical energy gap of PVA/Si heterojunction was utilized to modify this film from the UV to the visible spectrum. As show in the results,

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Publication Date
Sat Sep 30 2017
Journal Name
Al-khwarizmi Engineering Journal
Thermal Conductivity Enhancement of Iraqi Origin Paraffin Wax by Nano-Alumina
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Abstract

 

Paraffin wax is utilized for the heat storage applications taking advantage from the high stored latent heat during the phase change (from solid to fluid) period. What isn't right with this procedure is that the wax has a little heat transfer rate because of its low thermal conductivity. The thermal conductivity improvement of the paraffin wax has been examined utilizing nano-material with high thermal conductivity. In the recent study, (Al2O3) nanoparticles with weights of 1, 2, and 3% of the paraffin wax were added to the paraffin wax. The Iraqi paraffin wax accessible at the local markets was utilized as a phase change material (PCM).

Many properties of the

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Impact of empowerment and functional flexibility in evaluating worker performance :an empirical study
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This study was conducted in the Department of Employment and Loans at the Ministry of Labor and Social Affairs to indicate the importance and impact of both the empowerment and the functional flexibility in evaluating the performance of the employees. To achieve the objectives of the study, the data was collected through a questionnaire form designed for this purpose based on previous studies. Data obtained for a significant evaluation of the relationship between the components of both the empowerment and the functional flexibility with the components of the evaluation and determining the degree of importance of each component of both the empowerment and functional flexibility for the components of the evaluation by the extractio

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