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Experimental and Simulation for the Effect of Partial Shading on Solar Panel Performance
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Partial shading is one of the problems that affects the power production and the efficiency of photovoltaic module. A series of experimental work have been done of partial shading of   monocrystalline PV module; 50W, Isc: 3.1A, Voc: 22V with 36 cells in series is achieved. Non-linear power output responses of the module are observed by applying various cases of partial shading (vertical and horizontal shading of solar cells in the module). Shading a single cell (corner cell) has the greatest impact on output energy. Horizontal shading or vertical shading reduced the power from 41W to 18W at constant solar radiation 1000W/m2 and steady state condition. Vertical blocking a column of cells (9 cells) in a module reduces the power from 41W to 18W (53% power reduction); while, blocking one or two cell in the row reduces the power from 41 W to 18W (53% power reduction). Shading three or four cells in the same row reduces the power from 41W to 1W or 0.006W (94% power reduction). A complete Matlab / Simulink model are achieved to simulate the effect of partial shading on power output of module. It is found that shading a single cell reduces the power from 50 W to 25 W (50%) using Matlab/Simulink model. Comparisons have been made between the I-V and P-V characteristic curves from the simulation with the practical (experimental) curves. The results showed that the percentage of error between the Simulink results and the corresponding experimental measurement are 22% without shading effect and, 32% with partial shading.

 

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Publication Date
Mon Feb 01 2016
Journal Name
Journal Of Engineering
Dust Effect on the Efficiency of Silicon Mono Crystalline Solar Modules at Different Tilt Angles at Al-Jadryia Climate Conditions
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Solar energy usage in Iraq is facing many issues; one of those is the accumulation “of the dust on the surface of the solar module which” would highly lower its efficiency. The present work study the effect of dust accumulation” on installing fixed solar modules with different inclined angles 15o, 33o, 45o, 60o. Evaluation of the solar modules performance under different circumstance conditions such as rain, wind and humidity are considered in study of dust effect on solar module performance. The results show that the lowest output average efficiencies of solar modules occurs at 15o horizontally inclined angle are 7.4% , 6.7% , 8.0% , 8.1%, and 8.4% for the cor

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Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The effect of strategic decisions for operations management in performance excellence organizational.
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This research focused on clarifying the relationship strategic decisions for operations management & performance excellence organizational, The research emerges from a problem which explained by many application questions. Special questionnaire has been prepared for this purpose distributed (72) to sample of  management levels (Top, middle) in the General company for mining industries and aquatic Insullation & the General company of batteries industry, The research has tried to test a number hypotheses related to the relation and regression among the variables of the research, and the differences among the <

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Crossref
Publication Date
Sun Apr 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Effect of Discussion Techniques in Composition performance for The fifth preparatory student
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The present study aims at knowing the effect of discussion method for students of fifth grade in preparatory school.

Methodology of the Study:

          In order to achieve the objective of the study, the researcher chooses non-randomly the preparatory school affiliated to the District Chamchamal \ Suliemnaniya. The sample attained 64 students in 32 per group (control and experimental) groups. The researcher used the discussion method which was applied on experimental group. She uses the traditional method on the control group.

The researcher matched the two group in ago, intelligence, marks at the Kurdish Language in the previous year , pretest and posts for the indepe

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Publication Date
Thu Oct 01 2020
Journal Name
The Asian Efl Journal
The Effect of Flow as a Strategy on EFL Student-teachers' Performance and their Flow
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This study aims at suggesting flow as a strategy for training female EFL student-teachers in the teaching training course and finding out the effect of this strategy on their performance and their flow state. The training course syllabuses will be constructed according to the flow nine factors and the teaching skills. The measurement tools are the student-teacher performance checklist that has already been used by the department of English language and SHORT Flow State Scale (S FSS-2). The study population is represented with the (60) female student-teachers/ fourth stage/ evening studies at theEnglish department /college of education for women/the University of Baghdad. The study is used the experimental design in that (30) of the student-

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Scopus
Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of estimations methods of the entropy function to the random coefficients for two models: the general regression and swamy of the panel data
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In this study, we focused on the random coefficient estimation of the general regression and Swamy models of panel data. By using this type of data, the data give a better chance of obtaining a better method and better indicators. Entropy's methods have been used to estimate random coefficients for the general regression and Swamy of the panel data which were presented in two ways: the first represents the maximum dual Entropy and the second is general maximum Entropy in which a comparison between them have been done by using simulation to choose the optimal methods.

The results have been compared by using mean squares error and mean absolute percentage error to different cases in term of correlation valu

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Crossref
Publication Date
Fri Dec 19 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Histological and immunohistochemical evaluation of the effect of local exogenous application of VEGF on bone healing (experimental study in rat)
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Background: The repair of bone defects remains a major clinical orthopaedic challenge. Bone is a highly vascularised tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. Angiogenesis thus plays a pivotal role in skeletal development and bone fracture repair. The role of angiogenic and osteogenic factors in the adaptive response and interaction of osteoblasts and endothelial cells during the multi step process of bone development and repair will be highlighted in this study. This study aimed to identify the role of local exogenous vascular endothelial growth factor in bone healing and to analyze the expression of VEGF by immunohistochemistry in created bone defect af

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Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
Effect of Kerosene and Gasoline on Some Properties of High Performance Concrete
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During the last quarter century, many changes have taken place in the tanks industry and also in the materials that used in its production، while concrete is the most suitable material where concrete tanks has the benefits of strength, long service life and cost effectiveness. So, it is necessary improvement the
conventional concrete in order to adapt the severe environment requirements and as a result high
performance concrete (HPC) was used. It is not fundamentally different from the concrete used in the past, although it usually contains fly ash, ground granulated blast furnace slag and silica fume, as well as
superplasticizer. So, the content of cementitious material is high and the water/cement ratio is low. In this
stu

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Crossref
Publication Date
Thu Jun 30 2022
Journal Name
Pakistan Journal Of Medical And Health Sciences
The Effect of Music Therapy on Clients' Vital Signs during Pulmonary Function Test: An Experimental Study
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Background: The patient's vital signs must stay stable pre a pulmonary function test since the approach demands the patient to breathe slowly and deeply and exhale quickly. However, events that cause variations in normal vital signs may impact the patient. Many strategies can be utilized to stabilize vital signs, including music treatment. The purpose of this study is to compare the effectiveness of music therapy on the vital signs of client's pre a pulmonary function test. Methods: An experimental design study with an application (pre-test, post-test), to determine the effectiveness of music therapy for clients pre pulmonary function test for 106 clients in Al-Diwaniyah, Al-Shamiya, and Al- Hamza public hospitals In Iraq. Parti

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Crossref
Publication Date
Tue Dec 30 2008
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
The Effect of TCE Addition on the Performance of Catalytic Isomerization of n-Hexane
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n-Hexane conversion enhancement was studied by adding TCE (Trichloro-ethylene) on feed stream using 0.3%Pt/HY zeolite catalyst. All experiments were achieved at atmospheric pressure and on a continuous laboratory unit with a fixed bed reactor at a temperature range 240-270◦C, LHSV 1-3h-1, H2/nC6 mole ratio 1-4.
By adding 435 ppm of TCE, 49.5 mole% conversion was achieved at LHSV 1h-1, temperature of 270ºC and H2/nC6 mole ratio of 4, while the conversion was 18.3 mol% on the same catalyst without adding TCE at the same conditions. The activation energy decreased from 98.18 for pure Pt/HY zeolite to 82.83 kJ/mole by adding TCE. Beside enhancement the activity, selectivity and product distribution enhanced by providing DMB (Dimethyl b

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Publication Date
Wed Sep 01 2010
Journal Name
Al-khwarizmi Engineering Journal
The Effect of Surface Roughness on Thermohydrodynamic Performance in Misaligned Journal Bearings
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     In this work an approach has been developed to investigate the influence of surface roughness on thermohydrodynamic performance in aligned and misaligned journal bearings by considering an average flow model and deriving the shear flow factor for various roughness configurations, similar to the pressure flow factor. An average Reynolds equation for rough surfaces is defined in term of pressure and shear flow factors, which can be obtained by numerical flow simulation, though the use of measured or numerically generated rough surfaces. Reynolds, heat conduction and energy equations are solved simultaneously by using a suitable numerical technique (Finite Difference Method) to obtain the pressure and temperature di

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