Preferred Language
Articles
/
alkej-458
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 conditions was examined. The variation of angles of attack and wind velocity leads to different values of vortex loading coefficients and shedding frequencies. The relation between the dynamic characteristics and solar collector performance was evaluated. The finite element method was used to estimate the dynamic characteristic of the solar collector in addition to experimental work to evaluate the relation between the dynamic behavior of the collector and its performance.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sun Jan 19 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Effect flexibility of the Strategic human resources in improvement operational performance: "Survey study of views of a sample of managers, engineers and technicians in the Baghdad south 2/Station directorate of Electricity"
...Show More Authors

The research attempts to diagnose the level of the effect of human resources flexibility (employees skills flexibility, employees behaviors flexibility, and human resource practice flexibility) in the south al-rusafa directorate of a power  station one of the formations and the Ministry of Electricity, and impact of a range of variables related to the performance operational, namely, (efficiency, effectiveness)recognizing the importance of the subjects studied,& because of the importance of expected results of the field under consideration,researcher selected a sample of size (121) engineers and technicians of workers in the directorate. Was my hypotheses the major search of a relationship and impact between human resources flex

... Show More
View Publication Preview PDF
Publication Date
Fri Apr 12 2019
Journal Name
Journal Of Economics And Administrative Sciences
The effect of uncertainty in adopting the general requirements of strategic environmental assessment /exploratory study
...Show More Authors

Abstract                                                                  

The aim of the research is to demonstrate the role of uncertainty in adopting the general requirements for the strategic environmental assessment of service departments in Babil Governorate and the Environment Department. By focusing on a range of environmental problems, despite the efforts exerted to deal with the environme

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Matec Web Of Conferences
Effect of internal curing on performance of self-compacting concrete by using sustainable materials
...Show More Authors

This paper is devoted to investigate the effect of internal curing technique on the properties of self-compacting concrete. In this study, self-compacting concrete is produced by using limestone powder as partial replacement by weight of cement with percentage of (5%), sand is partially replaced by volume with saturated fine lightweight aggregate which is thermostone aggregate as internal curing material in three percentages of (5%, 10%, 15%) for self-compacting concrete, and the use of two external curing conditions which are water and air. The experimental work was divided into three parts: in the first part, the workability tests of fresh self-compacting concrete were conducted. The second part included conducting compressive str

... Show More
View Publication
Crossref (2)
Crossref
Publication Date
Mon Mar 15 2010
Journal Name
International Journal Of Poultry Science
Effect of Supplementing Different Levels of Chromium Yeast to Diet on Broiler Chickens Performance
...Show More Authors

The experiment was conducted at the Faculty of Agriculture University of Ain Shams-Egypt, from January to March 2008, to study the effect of different levels of chromium yeast (Cr-yeast) on broiler chickens performance, carcass quality and enzyme activity through 35 days of experimental periods. A total of 450 one-day old unsexed chickens (Cobb) strain were used. The birds were randomly allocated to five treatments with 3 replicates each. The treatments were control (T1) without supplementation and T2, T3, T4 and T5 which were supplemented with 0.5, 1, 1.5 and 2 mg Cr-yeast /kg diet, respectively. Live body weight and weight gain were significantly (p<0.05) higher when Cr-yeast were supplemented at 1 (T3), 1.5 (T4) and 2 (T5) mg/kg diet. Fe

... Show More
View Publication
Scopus (10)
Crossref (9)
Scopus Crossref
Publication Date
Thu Apr 15 2010
Journal Name
International Journal Of Poultry Science
Effect of Dietary Supplementation with Different Oils on Productive and Reproductive Performance of Quail
...Show More Authors

View Publication
Scopus (23)
Crossref (14)
Scopus Crossref
Publication Date
Mon Oct 01 2018
Journal Name
Chemical Physics Letters
Effect of heat treatment on photoelectrochemical performance of hydrothermally synthesised Ag2S/ZnO nanorods arrays
...Show More Authors

View Publication
Scopus (23)
Crossref (21)
Scopus Clarivate Crossref
Publication Date
Tue Oct 01 2019
Journal Name
Poultry Science
Effect of using ionized water on some productive and physiological performance of Japanese quails
...Show More Authors

This study was conducted to explore the effects of using ionized water on the productive and physiological performance of Japanese quails (Coturnix japonica). Our study was conducted at a private farm from 20th April, 2016 to 13th July, 2016 (84 d). One hundred 42-day-old Japanese quail chicks were used, divided randomly into 5 groups with 4 replicates. Treatments consisted in a control group (T1 - normal water:), alkaline (T2 - pH 8 and T3 - pH 9), and acidic water (T4 - pH 6 and T5 - pH 5). All birds were fed a balanced diet of energy and protein. The egg production ratio, egg weight, cumulative number of eggs, egg mass, feed conversion ratio, productivity per hen per week, and effects on plasma lipids, uric acid, glucose, calcium, and ph

... Show More
View Publication
Scopus (4)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Mon May 27 2019
Journal Name
Al-khwarizmi Engineering Journal
Prediction of Process Parameters That Affecting on Surface Roughness in Multi-Point Forming Process Using ANOVA Algorithm
...Show More Authors

 

Multipoint forming process is an engineering concept which means that the working surface of the punch and die is produced as hemispherical ends of individual active elements (called pins), where each pin can be independently, vertically displaced using a geometrically reconfigurable die. Several different products can be made without changing tools saved precious production time. Also, the manufacturing of very expensive rigid dies is reduced, and a lot of expenses are saved. But the most important aspects of using such types of equipment are the flexibility of the tooling. This paper presents an experimental investigation of the effect of three main parameters which are blank holder, rubber thickness and forming speed th

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Mar 01 2018
Journal Name
International Journal Of Science And Nature
EXPERIMENTAL AND THEORETICAL STUDY OF 3-BENZYL -2- MERCAPTOQUINOIZOLINE-4(3H)-ONE (BMQ) AS AN INHIBITOR OF CARBON STEEL CORROSION IN ACIDIC MEDIA
...Show More Authors

The inhibition of 3-Benzyl -2-mercaptoquinoizoline -4 (3H)-one (BMQ) on the corrosion of carbon steel in 0.5 M HCl studied by potentionstat polarization methods at 303–333 K. Results obtained show that BMQ act as inhibitor for carbon steel in HCl solution. The inhibition efficiency increase with increase in BMQ concentration. Activation parameters and Gibbs free energy for the adsorption process using Statistical Physics calculated and discussed. Quantum chemical calculations using DFT at the B3LYP/6-31G level of theory were used to calculate some electronic properties of the molecule to verify any correlation between the inhibitive effect and molecular structure of BMQ. The quantum calculations were proceeded to get data around correlati

... Show More
View Publication Preview PDF
Publication Date
Fri Feb 08 2019
Journal Name
Journal Of The College Of Education For Women
The role of an active teacher in developing the curriculum by using educational techniqes a theoretical study
...Show More Authors

Preparing teacher occupies the attention of many thinkers and philosophers since the age of
kaldinics ( people of mesoptam / 2342 pH ) to the Islamic age where moslems philosophers
focus their attention on thought and philosophy where the philosophy of that teaching
depends on : teacher , student and family begin .
So , the issue of preparing and training teacher occupies the attention of education scientists
depending on his vital and important role in implementing of teaching policies in philosophies
and Islamic educational thought , therefore , the preparing and development of the teacher
regards as one of the basics of teaching development because of its importance in
development of teaching performance and th

... Show More
View Publication Preview PDF