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
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 (2)
Crossref
Publication Date
Fri Mar 01 2024
Journal Name
Egyptian Journal Of Aquatic Biology And Fisheries
Carbon Sources and Riverine Algal Biomass: An Experimental Study
...Show More Authors

A lotic ecosystem is considered a source of carbon dioxide (CO2) in the atmosphere where it becomes supersaturated with CO2, which contributes to the global carbon cycle. To enhance our comprehension of the roles of CO2 in rivers, an outdoor experiment was designed with controlled carbon source inputs to investigate the roles of the dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the phytoplankton community. Plastic enclosures were installed in the Tigris River within Baghdad for that goal. Samples were collected on the first day, as well as on the 5th and the 12th days from 14 enclosures. The enclosures were treated by artificial glucose (C6H12O6) (10, 20, 30mg/ l) as DOC sources, while sodium bicarbonate (NaHCO3) (1

... Show More
View Publication
Scopus (1)
Scopus Crossref
Publication Date
Mon Apr 10 2023
Journal Name
The European Physical Journal Plus
Improved performance of D149 dye-sensitized ZnO-based solar cell under solvents activation effect
...Show More Authors

View Publication
Crossref (5)
Crossref
Publication Date
Sun Feb 24 2019
Journal Name
Iraqi Journal Of Physics
Construction and performance study of a solar - powered hybrid cooling system in Iraq
...Show More Authors

The systems cooling hybrid solar uses solar collector to convert solar energy into the source of heat for roasting Refrigerant outside of the compressor and this process helps in the transformation of Refrigerant from the gas to a liquid state in two-thirds the top of the condenser instead of two-thirds the bottom of the condenser as in Conventional cooling systems and this in turn reduces the energy necessary to lead the process of cooling. The system cooling hybrid use with a capacity of 1 ton and Refrigerant type R22 and the value of current drawn by the system limits (3.9-4.2A), the same value of electric current calculated by the system are  Conventional  within this atmosphere of Iraq, and after taking different readings

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Journal Of Engineering And Applied Sciences
Effect of silver doping for performance of CdS solar cell prepared by thermal vacuum evaporation
...Show More Authors

Publication Date
Sat Jun 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Study and Analysis of the Factors that Affect the Efficiency of Small and Medium Enterprises in the Kingdom of Saudi Arabia
...Show More Authors

Encouraging micro-enterprises for comprehensive economic development are crucial to achieve the ambitious vision 2030 of the Kingdom of Saudi Arabia.

 Small and Medium enterprises are inputting around 15.5 per cent to GDP while 33 per cent contribution as a private sector to Saudi Arabia's gross domestic product (GDP). This study aims to identify the most important factors that affect the efficiency of small enterprises in Saudi Arabia. To accomplish this objective, the study was conducted for small projects via the comprehensive inventory method under the supervision of the Institute of Entrepreneurship. A total of 282 questionnaires were collected from entrepreneurs and the differentiation analysis

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Apr 27 2022
Journal Name
Arabian Journal For Science And Engineering
Optical and Thermal Performance of a Parabolic Trough Collector for Different Receiver Geometries
...Show More Authors

This paper numerically and theoretically investigates the optical and thermal performance of a parabolic trough collector PTC system. Many numerical simulations and theoretical analyses are conducted to demonstrate the influence of the receiver geometry and shifting from the focal position on the optical performance. The examined receiver geometries are circular, square, triangular, elliptical, and the new circular–square combined geometry is named as channel receiver. The thermal performance of PTC is examined for different volume flow rates theoretically in the range of (0.36 to 2.4 lpm). The results show that the best optical design is the channel receiver with an intercept factor of 84%, while the worst is the elliptical receiver with

... Show More
View Publication
Scopus (19)
Crossref (11)
Scopus Crossref
Publication Date
Sun Jul 31 2022
Journal Name
Journal Of Ovonic Research
Effect of annealing on thin film AgInSe2 solar cell
...Show More Authors

AgInSe2 (AIS) thin films solar cell involving of n-type AgInSe2 and Si of p-type substrate by using thermal evaporation method. The influence of annealing of the preparation AgInSe2 were considered to find the best properties of solar device. Thin film AIS have been deposited under the vacuum of 1.5*10-6 Torr with (400) nm thickness at R.T and annealing temperatures (473,573) K. Polycrystalline tetragonal structure for AIS thin films from XRD and increasing of surface roughness from AFM, energy gap values decreasing with increasing annealing temperatures, all films were negative type, I-V characteristics show increasing of efficiency with increasing of annealing temperatures.

View Publication
Scopus (7)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Fri Feb 08 2019
Journal Name
Iraqi Journal Of Laser
Bactericidal Effect of CO2 Laser on Bacteria Associated With Dental Implant Infection: An In Vitro Study
...Show More Authors

One of the most popular causes for implant infection is dental plaque bacteria. Previous studies have shown the bactericidal effect of CO2 laser irradiation on bacteria associated with soft tissue surrounding the implant materials. No published studies have examined the effect of irradiation by CO2 laser on Streptococcus oralis and Staphylococcus aureus.The aim of this study was to evaluate the bactericidal effect of CO2 laser on bacteria that are causing dental implant infections. This study was carried out on two isolates of bacterial species out of 25 samples, isolated from patients having soft tissue infections around the dental implant. These two pure isolates including Streptococcus oralis and Staphylococcus aureus were identified

... Show More
View Publication Preview PDF
Publication Date
Tue Oct 01 2024
Journal Name
Energy And Buildings
Year-round performance evaluation of photovoltaic-thermal collector with nano-modified phase-change material for building application in an arid desert climate zone
...Show More Authors

View Publication
Scopus (24)
Crossref (25)
Scopus Clarivate Crossref