Preferred Language
Articles
/
jih-2609
Efficiency Evaluation of Solar Concentrator without Tracking System Type of Compound Parabolic Concentrator (CPC)
...Show More Authors

      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.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Jul 01 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Analyzing impact of competitive dimensions on the efficiency of e-learning: دراسه استطلاعيه
...Show More Authors

The aim of this research is to diagnose the impact of competitive dimensions represented by quality, cost, time, flexibility on the efficiency of e-learning, The research adopted the descriptive analytical method by identifying the impact of these dimensions on the efficiency of e-learning, as well as the use of the statistical method for the purpose of eliciting results. The research concluded that there is an impact of the competitive dimensions on the efficiency of e-learning, as it has been proven that the special models for each of the research hypotheses are statistically significant and at a level of significance of 5%, and that each of these dimensions has a positive impact on the dependent variable, and the research recommended

... Show More
View Publication Preview PDF
Publication Date
Sat Dec 04 2021
Journal Name
Plant Science Today
Isolation, characterization and quantification of a pentacyclic triterpinoid compound ursolic acid in Scabiosa palaestina L. distributed in the north of Iraq
...Show More Authors

Ursolic acid (UA, 3 ?-hydroxy-urs-12-en-28-oic acid) are isomeric triterpenic acids. The high quantities of pentacyclic triterpenoids in Scabiosa species seems to be obvious and there is an evidence that most of pentacyclic triterpenoids that have been isolated are saponins. This is one of the most important characteristic of the genus Scabiosa, the main aglycones are ursolic acid and oleanolic acid. In the current study, isolation from the aerial part and roots of Scabiosa palaestina L. was performed using Preparative HPLC. Furthermore, detection and quantitation of ursolic acid was performed by high performance thin layer chromatography (HPTLC). The identification of isolated triterpenoid involves two methods including FT-IR coupl

... Show More
View Publication
Scopus (6)
Scopus Clarivate Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Journal Of Biomechanical Science And Engineering
A COMPARATIVE STUDY OF RETN GENE 3ʹ-UNTRANSLATED REGION POLYMORPHISM RS1862513 IN IRAQI PATIENTS WITH TYPE 1 AND TYPE 2 DIABETES MELLITUS
...Show More Authors

Both type 1 diabetes and type 2 diabetes have a genetic component, with over 60 chromosomal regions related to type 1 diabetes and over 200 connected with type 2 diabetes at significant genome-wide levels. Numerous single nucleotide polymorphisms in the RETN gene and genetic variables can account for up to 70% of the variations in circulating resistin levels. The RETN polymorphism has been linked in numerous studies to obesity, insulin sensitivity, type 2 diabetes, and cerebrovascular illness. Our objective is to compare this RETN gene 3ʹ-untranslated region polymorphism in type 1 diabetes and type 2 diabetes Iraqi patients. We choose 51 type 1 diabetes and 52 type 2 diabetes patients against 50 healthy subjects (control group) to investig

... Show More
Scopus
Publication Date
Mon Sep 01 2014
Journal Name
Al-khwarizmi Engineering Journal
An Experimental Study of the Effect of Vortex Shedding on Solar Collector Performance
...Show More Authors

In this work, the effect of vortex shedding on the solar collector performance of the parabolic trough solar collector (PTSC) was estimated experimentally. The effect of structure oscillations due to wind vortex shedding on solar collector performance degradation was estimated. The performance of PTSC is evaluated by using the useful heat gain and the thermal instantaneous efficiency. Experimental work to simulate the vortex shedding excitation was done. The useful heat gain and the thermal efficiency of the parabolic trough collector were calculated from experimental measurements with and without vortex loading. The prototype of the collector was fabricated for this purpose. The effect of vortex shedding at different operation condition

... Show More
View Publication Preview PDF
Publication Date
Mon Dec 18 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental and Theoretical Study for Performance Enhancement of Air Solar Collectors by Using Different Absorbers
...Show More Authors

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

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2022
Journal Name
Political Sciences Journal
Transformation in International Polar System: Study of the future of the nonpolar system
...Show More Authors

The study of the future of the international system currently appears, according to scientific data and existing facts in light of the emergence of international actors from non-states and international informal institutions, to be heading towards a non-polarity system and this trend is fueled by many variables to reduce polarity, and it is expected in the future that the international system will turn into a non-polarity.

 

View Publication Preview PDF
Crossref
Publication Date
Sun Mar 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Preparation of Zeolite Type 13X from Locally Available Raw Materials
...Show More Authors

The aim of this work was to prepare zeolite type 13X from locally available kaolin and to study the effects of using some binding materials through the process of agglomeration of this zeolite. This study was focused on using kaolin binder in different weight percents (10,15,25,35 and 45%).Physical and mechanical properties of the agglomerates such as porosity , apparent density , pore volume, crushing strength , loss on attrition , surface area and finally the adsorption capacity had been measured and evaluated .The preparation step was achieved by mixing the reactants consisting of metakaolin , source of silica as ( sodium trisilicate ) and sodium hydroxide . The conditions was temperature of 70° C and time of mixing as 8, 10,24,34,50

... Show More
View Publication Preview PDF
Publication Date
Sun May 16 2021
Journal Name
Graphs And Combinatorics
Commuting Involution Graphs for Certain Exceptional Groups of Lie Type
...Show More Authors
Abstract<p>Suppose that <italic>G</italic> is a finite group and <italic>X</italic> is a <italic>G</italic>-conjugacy classes of involutions. The commuting involution graph <inline-formula><alternatives><tex-math>$${\mathcal {C}}(G,X)$$</tex-math><math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mrow> <mi>C</mi> <mo>(</mo> <mi>G</mi> <mo>,</mo> <mi>X</mi> <mo>)</mo> </mrow> </math></alternatives></inline-formula> is</p> ... Show More
View Publication
Scopus (4)
Crossref (1)
Scopus Clarivate Crossref
Publication Date
Fri Nov 09 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Infants’ Obesity and Overweight in Relation to Type of Feeding
...Show More Authors

Abstract Objective (s): To identify the prevalence of obesity and overweight in infants and children less than 2 years of age and its relationship with type of feeding in a sample of children attending Al- Kadhymia primary health care center. Methodology: This study was a descriptive survey carried out in, the primary health care centre of Al-Kadhymia town in Baghdad during the period from 5th of July 2009-1st of May 2010. Sample was chosen by non probability convenience sampling and it included 744 infant and children. Data were gathered by a combination of a structured questionnaire and measurements o

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 01 2014
Journal Name
Baghdad Science Journal
Producing Ceramic Water Purifiers Made Of Iraqi Bentonite Type (Bpl1)
...Show More Authors

In this study, ceramic purifier (CP) was produced from a mixture of Iraqi raw materials. This ceramic mixture was prepared using Bentonite as a Clay, Porcelanite as a Silica, and Limestone as a flux. The produced ceramic filter was formed by semi-dry compressing method and was fired at 1200 C?. Physical properties of the produced CP were measured. A hydraulic test rig was constructed to study the hydraulic conductivity of the produced CP. The average hydraulic conductivity of the produced CP was 55 times that of commercial types of ceramic filters. The mineral composition of the produced ceramics was found by X-Ray tests. Tests results showed that all of the produced ceramics filters composed mainly of low Cristobalte and Tridoymite in addi

... Show More
View Publication Preview PDF
Crossref (1)
Crossref