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
Fri Aug 20 2021
Journal Name
Iraqi Journal Of Laser
Effect of Low Energy Laser on the Healing of Tooth Extraction Wound: (Histological Study in Rat)
...Show More Authors

Aims: This study was done to investigate the effect of low energy laser therapy on bone healing at the extraction site. Materials and methods:(24) male albino rats were exposed to the extraction procedure of the maxillary first molar on the first day of a seven day experiment and these animals were divided into two main groups; the control group and the laser group. The laser experiment involved using (Ga-As infrared diode laser) from optodent by directing the probe over the extraction site. The control group consisted of 4 rats, and the laser group was subdivided into 5 subgroups of 4 rats each. The laser dose was as follows: B1: a single dose of 5 minutes immediately after extraction.,

... Show More
View Publication Preview PDF
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of The Mechanical Behavior Of Materials
Experimental and numerical study of the bulb's location effect on the behavior of under-reamed pile in expansive soil
...Show More Authors
Abstract<p>In this experimental and numerical analysis, three varieties of under-reamed piles comprising one bulb were used. The location of the bulb changes from pile to pile, as it is found at the bottom, center, and top of the pile, respectively. <italic>PLAXES 3D</italic> was used to conduct the research. In expansive soil, the under-reamed piles were 350 mm long, with the pile tip in dense sandy soil. The experiment was carried out in both saturated and unsaturated circumstances. The influence of the bulb location on the pile's bearing capacity for vertical and lateral loads, as well as the amount of swelling pressure and upward movement owing to swelling, was investigated. The re</p> ... Show More
Crossref (6)
Crossref
Publication Date
Tue Oct 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Efficiency of Human Resources Information System and Its Impact on The Level Effectiveness of Employees Performance Appraisal System / Practical Research on Ministry of Higher Education and Scientific Research
...Show More Authors

Abstract

The research aims to determine the role of the efficiency of Human Resources Information System in the effectiveness of Employees Performance Appraisal System in the Ministry of Higher Education and Scientific Research / Center for the ministry, it was touching the researchers need the ministry to devise methods that employ outputs Human Resources Information System in the organization surveyed for the development of methods and levels of process evaluate the performance of its employees, in order to identify the extent of the role played by human resources information system in the process of assessing the performance of employees, we raised the question of the President as follows:

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Apr 08 2018
Journal Name
Al-khwarizmi Engineering Journal
Study the Effect of Welding Heat Input on the Microstructure, Hardness, and Impact Toughness of AISI 1015 Steel
...Show More Authors

In the present study, MIG welding is carried out on low carbon steel type (AISI 1015) by using electrode ER308L of 1.5mm diameter with direct current straight polarity (DCSP). The joint geometry is of a single V-butt joint with one pass welding stroke for different plate thicknesses of 6, 8, and 10 mm. In welding experiments, AISI 1015 plates with dimensions of 200×100mm and edge angle of 60o from both sides are utilized. In this work, three main parameters related to MIG welding process are investigated, which are welding current, welding speed, heat input and plate thickness, and to achieve that three groups of plates are employed each one consists of three plates. The results indicate that increasing the weld heat input (t

... Show More
View Publication Preview PDF
Publication Date
Tue Jan 01 2019
Journal Name
Aip Conference Proceedings
Effect of in on the properties of AlSb thin film solar cell
...Show More Authors

View Publication
Scopus (17)
Crossref (10)
Scopus Clarivate Crossref
Publication Date
Mon Aug 19 2024
Journal Name
Chalcogenide Letters
Influence of copper on zinc oxide films and solar cell performance
...Show More Authors

Copper doped Zinc oxide and (n-ZnO / p-Si and n-ZnO: Cu / p-Si) thin films thru thickness (400±20) nm were deposited by thermal evaporation technique onto two substrates. The influence of different Cu percentages (1%,3% and 5%) on ZnO thin film besides hetero junction (ZnO / Si) characteristics were investigated, with X-ray diffractions examination supports ZnO films were poly crystal then hexagonal structural per crystallite size increase from (22.34 to 28.09) nm with increasing Cu ratio. The optical properties display exceptional optically absorptive for 5% Cu dopant with reduced for optically gaps since 3.1 toward 2.7 eV. Hall Effect measurements presented with all films prepared pure and doped have n-types conductive, with a ma

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Role of the Auditor in Confirming the Integrated Reports - An Exploratory Study on a Sample of External Auditors in Iraq-
...Show More Authors

  The aim of the research is to identify the extent of the ability to ensure the integrated reports by the auditor in verifying the credibility of these reports, and their implications for the benefit of all parties dealing with the economic unit, as well as measuring the impact of the assurance procedures followed by the auditors and their role in confirming these reports.

  The research methodology was designed after studying the previous literature related to the research variables, and then the relationship between these variables was tested, through the use of a questionnaire list. A questionnaire targeting the community of auditors in the local environment, and the results of the study wer

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Sat Nov 27 2021
Journal Name
Lecture Notes In Civil Engineering
An Experimental Study on Concavely Curved Soffit Reinforced Concrete Beams Externally Bonded with FRP
...Show More Authors

View Publication
Crossref (1)
Crossref
Publication Date
Fri Jul 25 2025
Journal Name
Modern Sport
The Effect of Training Exercises Using an Innovative Device on Developing Skill Performance Among Female Foil Fencers
...Show More Authors

View Publication
Crossref
Publication Date
Tue Aug 16 2022
Journal Name
Heat Transfer
Experimental study on thermo‐hydraulic performance of metal foam twisted tape in a double pipe heat exchanger
...Show More Authors
Abstract<p>A recent study compared experimentally the hydraulic and thermal activity of twisted tape inserts for two types, metal foam twisted tape (MFTT) and traditional twisted tape (TTT), in a double pipe heat exchanger. The investigation goal of the innovatively designed MFTT is to enhance the heat transfer process, which provides a higher thermal enhancement factor over those of TTT under the same conditions. Heat transfer activity in terms of Nusselt number (<italic>Nu</italic>) and Nusselt number ratio (<italic>Nu</italic>/<italic>Nu</italic><sub>o</sub>) as the heat exchanger equipped with the proposed MFTT and TTT inserts with various tape‐twist ratios (<i></i></p> ... Show More
View Publication
Scopus (16)
Crossref (17)
Scopus Clarivate Crossref