Preferred Language
Articles
/
alkej-232
Influences of the Twisted Strips Insertion on the Performance of Flat Plate Water Solar Collector
...Show More Authors

Abstract

    In order to enhance the efficiency of flat plate solar water collectors without changing in its original shape and with low additional cost, twisted strips are inserted inside its riser pipes. Three flat plate collectors are used for test. Family of twisted strips are inserted inside each collector risers with different twisted ratios (TR=3,4,5). The collectors are connected in parallel mode (Z-Configuration) and are exposed to the same conditions (solar radiation and ambient temperature) .The experimental results show that, the highest heat transfer rate occurs at twisted ratio (3) .Consequently, for the same twisted ratio the daily efficiencies for the solar collector at different flow rate used (60,100 and 150) ℓ /hr. were 49 %, 57% and 63% respectively.

 Keywords: Twisted strip, solar collectors.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Mar 30 2021
Journal Name
Scientific Review Engineering And Environmental Studies (srees)
Testing the performance of a solar energy cooling system in Baghdad city
...Show More Authors

Renewable energy resources have become a promissory alternative to overcome the problems related to atmospheric pollution and limited sources of fossil fuel energy. The technologies in the field of renewable energy are used also to improve the ventilation and cooling in buildings by using the solar chimney and heat exchanger. This study addresses the design, construction and testing of a cooling system by using the above two techniques. The aim was to study the effects of weather conditions on the efficiency of this system which was installed in Baghdad for April and May 2020. The common weather in these months is hot in Baghdad. The test room of the design which has a size of 1 m3 was situated to face the geographical south. The te

... Show More
View Publication Preview PDF
Scopus (3)
Crossref (1)
Scopus Crossref
Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Produced Water Treatment Using Ultrafiltration and Nanofiltration Membranes
...Show More Authors

The application of ultrafiltration (UF) and nanofiltration (NF) processes in the handling of raw produced water have been investigated in the present study. Experiments of both ultrafiltration and nanofiltration processes are performed in a laboratory unit, which is operated in a cross-flow pattern. Various types of hollow fiber membranes were utilized in this study such as poly vinyl chloride (PVC) UF membrane, two different polyether sulfone (PES) NF membranes, and poly phenyl sulfone PPSU NF membrane. It was found that the turbidity of the treated water is higher than 95 % by using UF and NF membranes. The chemical oxygen demand COD (160 mg/l) and Oil content (26.8 mg/l) were found after treatment according to the allowable limits set

... Show More
View Publication Preview PDF
Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
Evaluating the performance of inspectors general offices in reducing corruption According to global indicators(Field research comparative)
...Show More Authors

Abstract

        This research aims to evaluate the application of the inspectors general of global indicators offices according to the axles (leadership, strategy and planning, employees, partners and resources, process management) and through the assumption main research which states that (there is an application for global indicators to evaluate performance in the offices of the ministries under study) which are subdivided into five sub-hypotheses according to the classification and division of the five axes of the checklist.

The researchers have taken refuge in the process of assessing the performance of the check list which included global i

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Dec 17 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Study Using the Passive Solar Chimney for Evaporative Cooling With PCM and CFM as a Thermal Energy Storage
...Show More Authors

 

      In this work, a test room was built in Baghdad city, with (2*1.5*1.5) m3  in dimensions, while the solar chimneys (SC) were designed with aspect ratio (ar) bigger than 12. Test room was supplied by many solar collectors; vertical single side of air pass with ar equals 25, and tilted 45o double side of air passes with ar equals 50 for each pass, both collectors consist of flat thermal energy storage box collector (TESB) that covered by transparent clear acrylic sheet, third type of collector is array of evacuated tubular collectors with thermosyphon in 45o instelled  in the bottom of TESB of vertical SC. The TESB was

... Show More
View Publication Preview PDF
Publication Date
Fri Jul 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Performance Evaluation for Higher and Medium Leadership in Institutional Work Quality.
...Show More Authors

Abstract:

This Research aims to define role of the system of evaluating the performance for higher leadership in determining the level of institutional work quality in the Ministry of Agriculture, by measuring system efficiency of evaluating the performance for higher leadership and its effect in institutional work quality, the searcher reached through the theoretical framing and involved studies to build default plan define the relation between Research variables formed from system of evaluating leadership performance as independent variable contains six subsidiary dimensions: (Polarization, evaluating the performance of personnel, training, motivation, se

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Sep 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Expermental Comparison For The Performance of Circular And Square Solar Cell
...Show More Authors

An    Experimental     comparison     between     the     current-voltage

characteristic and    the  efficiency    conversion from  solar  to  electric energy   were studied  for square  and circular  single crystal  silicon  solar

cell of equal area (35.28  cm2)  . The results show  that the solar shape is

an  important factor  in  calculating the  current-voltage characteristics and  efficiency of  the  solar  cell.  It was  shown   that  the  performance effici

... Show More
View Publication Preview PDF
Publication Date
Sat Feb 22 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of time management on the performance of the functional business: Survey study at Al Salam General Company for Communications and Information Technology
...Show More Authors

The aim of the research is to know the level of time management application and its impact on the performance of the job, a survey search in the general company for communication and information technology and provide recommendations that help employees to optimize the use of time and improve performance, which is an important element in controlling the various functions of the company. In order to achieve the objectives of the research, the questionnaire was based on two main variables and distributed to a random sample of (44) employees in the company out of (308) employees, thus the proportion of the sample (14%). After collecting the samples from the sample, there are (6) incomplete forms that have been retri

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Sep 30 2023
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
A proposed program to audit the performance of the hotel sector under crises (Applied Research)
...Show More Authors

Abstract:

        The research sought to identify the crises that occurred during the research period and their reflection on the performance of the hotel Research sample as well as to identify the reality of auditing the hotel Research sample and the preparation of a performance audit program can be adopted in auditing the performance of hotels in light of crises, and the problem of the research lies in the lack of a program to audit the performance of hotels that takes into account the crises experienced by the hotel sector, The research was based on solving its problems on three hypotheses, the first is that the performance audit in light of the Covid-19 pand

... Show More
View Publication Preview PDF
Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
The impact of e-governance on achieving creative performance
...Show More Authors

The research aims to investigate the relationship and impact of e-governance as an independent variable in achieving creative performance as a dependent variable. These variables have been studied in the Directorate of Passports Affairs, and seek to come up with a set of recommendations that help in promoting e-governance in the researched organization, and the researcher adopted the descriptive-analytical approach, included The sample (122) of the total (194) individuals distributed in several administrative levels (officers, associates, and administrative staff). By adopting the questionnaire, which included (49) paragraphs as the main tool for the collection of data and information, as well as personal interviews and field obs

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The impact of wages and benefits systems on the performance of employees A field study in the General Company for Food Industries in the city of Baghdad
...Show More Authors

The research aims to find out the impact of wages and benefits systems on the performance of employees, which included the research community on a sample of employees in the company, and the sample consisted of (50) employees and an employee, A questionnaire composed as prepared (23) paragraph, use the promised statistically methods in data collected by the questionnaire analysis. The research reached a number of results, the most prominent of which were: There is a correlation between wage systems, benefits and performance of employees, and the presence of the impact of the systems of wages and benefits to the performance of employees. The research was presented a set of recommendations including: increasing the effectiveness of

... Show More
View Publication Preview PDF
Crossref