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Efficiency Evaluation of Solar Concentrator without Tracking System Type of Compound Parabolic Concentrator (CPC)
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      It is useful to analyze any optical system theoretically before proceeding with its design in order to ensure the effectiveness of the design through computer simulations that are important and useful in designs for the ability to predict the performance of solar concentrator under any conditions.  For this design, non-sequential ray tracing mode wasused in the Zimax program with a light source that simulated solar radiation.  The purpose of the design of a compound parabolic concentrator (CPC) is to take advantage of the solar radiation that falls on it without the need for an efficiently tracked system within certain limits of the angle of solar radiation fall known as the acceptance angle.  That is, obtaining the largest possible number of rays received inside the CPC through reflections in the inner walls of it, which give a large amount of thermal energy to the surface of the recipient, which in turn gets this energy to be used to create electrical energy. The efficiency of receiving reflected solar radiation in this type of concentrator is great compared to other solar concentrators.

Simulated design of solar reflector concentrator has been presented. The concentrator is a type of compound parabolic concentrator (CPC) involved of internal reflector surface (Hollow and within Poly methyl methacrylate (PMMA) polymer material) without tracking system. CPC has the property to overcome problems result from variation of incidence angle of the sun during daytime. Because the tracking system expensive and has technical problems. The efficiency of CPC has been obtained by using Zemax optical design program, for different designs has concentration ratio(c=1,2,3,4,5). That is, the ratio of the output aperture to the input aperture. Taking into account the angle of acceptance that plays a major role in the form of design and its efficiency the results are shown when designing the model with radial aperture of (50mm) and length of (500mm).The design of concentrations ratio is depends on the acceptance angle.

c=5 at normal incident angle (ÆŸ=0). And it is almost similar if the material is used PMMA within CPC, and degradation of efficiency with increasing the incidence angle.

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Publication Date
Fri May 01 2015
Journal Name
Journal Of Engineering
Experimental Study of the Thermal Performance of Flat Plate Solar Collectors Array by Different Connection Configurations
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The current research illustrates experimentally the effect of series and parallel connection (Z-I Configurations) of flat plate water solar collectors array on the thermal performance of closed loop solar heating system. The study includes the effect of changing the water flow rate on the thermal efficiency. The results show that, the collector's efficiency in series connection is higher than the parallel connection within flow rate level less than (100) ℓ/hr. Moreover, the collector efficiency in parallel connection of (I-Configurations) is more than the (Z- Configurations) with increasing the water flow rate .The maximum daily efficiency for parallel (I-Configurations) and (Z- Configurations) are (55%) and (51%) at w

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Publication Date
Tue Jan 01 2019
Journal Name
Opción
Phraseological units of the idafa type in the Quran
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Publication Date
Mon Oct 01 2012
Journal Name
Iraqi Journal Of Physics
Structural and morphological study of nanostructured n-type silicon
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In this study, investigations of structural properties of n-type porous silicon prepared by laser assisted-electrochemical etching were demonstrated. The Photo- electrochemical Etching technique, (PEC) was used to produce porous silicon for n-type with orientation of (111). X-ray diffraction studies showed distinct variations between the fresh silicon surface and the synthesized porous silicon surfaces. Atomic force microscopy (AFM) analysis was used to study the morphology of porous silicon layer. AFM results showed that root mean square (RMS) of roughness and the grain size of porous silicon decreased as etching current density increased. The chemical bonding and structure were investigated by using fourier transformation infrared spec

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Publication Date
Fri Dec 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Effect of the Quality of Accounting Information on the Efficiency of Investment Decisions
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Abstract

The entities responsible for regulating the financial market are seeking to provide high quality accounting information, to provide appropriate protection to investors, and thus encourage them and attract them to increase their investments. the research reached several conclusion, the most prominent of which comes  :-

1-The production of high quality accounting information reduces investment costs and costs of processing accounting information.

2- The production of high quality accounting information helps investors identify the best investment opportunities.

3- The results of the statistical analysis showed that there is significant

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Publication Date
Sat Jan 20 2024
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Comparison of the Optical Efficiency of Two Designs of the Maksutov–Cassegrain Telescope
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The research aims to develop the best possible design for the widely used Cassegrain telescope. The system consists of two models of different designs: (a) the telescope consists of a Maksutov lens, a spherical primary mirror, and a secondary mirror attached to the lens; (b) it consists of a Maksutov lens and a spherical primary mirror, plus a non-lens attached secondary mirror located between the lens and the primary mirror. The image was evaluated and analyzed using the analysis tools in Zemax software. The results of the two designs showed that the telescope whose secondary mirrors are not adjacent to the Maksutov lens produces high quality image that is almost free from aberration, and then comes the telescope whose secondary mirrors

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Publication Date
Thu Apr 01 2021
Journal Name
Iop Conference Series: Materials Science And Engineering
Evaluating the Efficiency of some Wastewater Treatment Plants in Najaf Governorate
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Abstract<p>Although there are many wastewater treatment plants, we still suffer from many problems resulting from a lack of experience or technical operating problems. In this research, the service’s efficiency is evaluated according to the design laws required for small factories in the province of Najaf, which works with filtering technology through point filtration, the old project in the Al-Baraka plant, and the second works. Within the biological treatment mbbr + activated sludge, which is a biomass technology where samples were taken from both plants and annual values of the pollutant rate after treatment in the old Al-Baraka plant project COD 64 mg/L and the demand for biochemical oxyge</p> ... Show More
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Publication Date
Tue Mar 20 2018
Journal Name
1st International Conference On Applied Agricultural Sciences And Prospective Technology
Water Productivity and Efficiency of Irrigated Corn Farms in Babylon Governorate
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Publication Date
Sun Apr 01 2018
Journal Name
Journal Of Educational And Psychological Researches
Counseling program efficiency in developing emotional competence of intermediate school students
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Emotional competence, is relatively a new concept, stands for the ability of people to perceive their feelings and emotions, and sharing them with others. It also refers to capability in optimizing these feeling and emotions, and managing them over various situations. Thus, this study aims to examine the efficiency of counseling program in developing an emotional competence among intermediate school students in Baghdad city. The sample included group of female students at intermediate stage. The findings revealed none of experimental and control groups have statistically significant differences in pre-posttests of emotional competence efficiency.

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Publication Date
Fri Sep 14 2018
Journal Name
Radiation Effects & Defects In Solids
Effect of gamma and beta radiation on I–V characterization of the solar cell panel
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Optoelectronic devices, widely used in high energy and nuclear physics applications, suffer severe radiation damage that leads to degradations in its efficiency. In this paper, the influence of gamma radiation (137Ce source) and beta radiation (90Sr source) on the photoelectric parameters of the Si solar cell, based on the I–V characterization at different irradiation exposer, has been studied. The penetrating radiation produces defects in the base material, may be activated during its lifetime, becoming traps for electron–hole pairs produced optically and, this will, decrease the efficiency of the solar cell. The main objective of the paper is to study and measure changes in the I–V characteristics of solar cells, such as efficienc

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Publication Date
Sun Mar 02 2014
Journal Name
Baghdad Science Journal
Comparison of Properties of Various Heat Storage Fluids used with Evacuated Tube of Solar Water Heater
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The aim of this work was to capture solar radiation and convert it into solar thermal energy by using a storage material and the heat transfer fluid like oil and water and comparison between them, we used the evacuated tube as a receiver for solar radiation, The results showed that the oil better than water as storage material and the heat transfer fluid and the effective thermal conductivity material and good for power level, rates and durations of charge and discharge cycles.

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