Preferred Language
Articles
/
alkej-265
Experimental Study on the Effect of Insertion of Copper Lessing Rings in Phase Change Material (PCM) on the Performance of Thermal Energy Storage Unit
...Show More Authors

Abstract

One of the most suitable materials to be used in latent heat thermal energy storage system (LHTES) are Phase change materials, but a problem of slow melting and solidification processes made many researchers focusing on how to improve their thermal properties. This experimental work concerned with the enhancing of thermal conductivity of phase change material. The enhancing method was by the addition of copper Lessing rings in phase change material (paraffin wax). The effect of diameter for the used rings was studied by using two different diameters (0.5 cm and 1cm). Also, three volumetric percentages of rings addition (3%, 6% and 10%) were tested for each diameter. The discharging process was done with four velocities for each case. The obtained results indicated that the maximum volumetric percentage gave a diminished time for melting and maximized the heat transfer in both PCM and air sides as compare with the case of no rings, but the effect of these rings had lower effect on the solidification time. In case of 1 cm rings diameter minimum time for melting was obtained for both 3% and 6% volumetric percentages as compared with the same percentages in case of 0.5 cm diameter rings, while the latter with 10% volumetric percentage overcomes the 1 cm diameter rings for the same previous percentage. Also it can be seen that the minimum velocity (v=1m/s) gave the utmost outlet temperature and with the maximum one (v=3m/s), the minimum solidification time achieved.

Keyword: Thermal energy storage systems, Latent heat storage, Phase change materials, Heat transfer enhancement.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Jul 06 2022
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Using of costs based on activity that focused on performance in Reduce Costs and their reflection to improve competitive advantage: An applied research in wasitTextile and Knitting factory
...Show More Authors

The research aims mainly to the role of the statement style costs on the basis of activity based on performance (PFABC) to reduce production cost and improve the competitive advantage of economic units and industrial under the modern business environment dominated by a lot of developments and changes rapidly, which necessitates taking them and criticize them to ensure survival and continuity.  The research problem is the inability of traditional cost methods of providing useful information to the departments of units to take many administrative decisions, particularly decisions related to the product and calculating the costs of the quality of the sound and the availability of the need and the ability to replace methods capa

... Show More
View Publication Preview PDF
Publication Date
Mon Apr 21 2025
Journal Name
Structural Concrete
On the effectiveness of shear reinforcement type in <scp>GFRP</scp>‐reinforced concrete beams: Experimental study
...Show More Authors
Abstract<p>This study investigated the shear performance of concrete beams with GFRP stirrups vs. traditional steel stirrups. Longitudinal glass fiber‐reinforced polymer (GFRP) bars were used to doubly reinforce the tested beams at both the top and bottom of their cross sections. To accomplish this, several stirrup spacings were provided. Eight beam specimens, measuring 300 × 250 × 2400 mm, were used in an experimental program to test under a two‐point concentrated load with an equal span‐to‐depth ratio until failure. Four beams in Group I have standard mild steel stirrups of 8 mm diameter, while four beams in Group II have GFRP stirrups with the same adopted diameter. The difference betwe</p> ... Show More
Scopus (10)
Crossref (9)
Scopus Clarivate Crossref
Publication Date
Mon Apr 21 2025
Journal Name
Structural Concrete
On the effectiveness of shear reinforcement type in <scp>GFRP</scp>‐reinforced concrete beams: Experimental study
...Show More Authors
Abstract<p>This study investigated the shear performance of concrete beams with GFRP stirrups vs. traditional steel stirrups. Longitudinal glass fiber‐reinforced polymer (GFRP) bars were used to doubly reinforce the tested beams at both the top and bottom of their cross sections. To accomplish this, several stirrup spacings were provided. Eight beam specimens, measuring 300 × 250 × 2400 mm, were used in an experimental program to test under a two‐point concentrated load with an equal span‐to‐depth ratio until failure. Four beams in Group I have standard mild steel stirrups of 8 mm diameter, while four beams in Group II have GFRP stirrups with the same adopted diameter. The difference betwe</p> ... Show More
View Publication
Scopus (10)
Crossref (9)
Scopus Clarivate Crossref
Publication Date
Wed Feb 25 2026
Journal Name
Journal Of Baghdad College Of Dentistry
The surface roughness of new fluoride releasing material after using three polishing protocols and storage in artificial saliva
...Show More Authors

Background: Prophylaxis methods are used to mechanically remove plaque and stain from tooth surfaces; such methods give rise to loss of superficial structure and roughen the surface of composites as a result of their abrasive action. This study was done to assess the effect of three polishing systems on surface texture of new anterior composites after storage in artificial saliva. Materials and methods: A total of 40 Giomer and Tetric®N-Ceram composite discs of 12 mm internal diameter and 3mm height were prepared using a specially designed cylindrical mold and were stored in artificial saliva for one month and then samples were divided into four groups according to surface treatment: Group A (control group):10 specimens received no surfa

... Show More
View Publication Preview PDF
Publication Date
Thu Jan 04 2024
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Creative accounting practices for supply contracts and the role of internal audit in reducing them: An exploratory study on a sample of industrial companies in Iraq
...Show More Authors

Abstract:

                The internal control is the tool through which it is possible to verify and ensure the implementation of tasks in accordance with the established plans and programs and to evaluate the level of performance that is implemented within the different companies.

A guarantee from the supplier with the absence of a specialized technical committee that follows up the stages of implementing the contract and disbursing all amounts of financial dues to the supplier before completing the implementation of the contract and overlooking the non-implementation of some clauses of the contract by the committee in charge of

... Show More
View Publication Preview PDF
Publication Date
Mon Jun 01 2009
Journal Name
Al-khwarizmi Engineering Journal
Effect of Adding Alcohols and Gas Velocity on Gas Hold up and Mass Transfer Coefficient in Bubble Columns with Draught Tube
...Show More Authors

     The bubble columns are widely used as a two or three phase reactor in industrial chemical process such as absorption, biochemical reactions, coal liquefaction, etc. To design such a column, two main parameters should be taken in consideration, the gas hold-up (), and the liquid phase mass transfer coefficient KLa. The study includes the effect of gas velocity and the addition of alcohols on gas hold-up and mass transfer coefficient in bubble column with draught tube when the length of the column is 1.5m and the ratio of the draught tube diameter to the column diameter equals 0.5 and the air dispersion into the base of the draught tube using a multi hole tuyere is equivalent to a diameter of 0.15 mm and

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 20 2018
Journal Name
Al-academy
The stylistic change in Kandinsky and Mondrian paintings
...Show More Authors

The current rasearch which is entitled " The stylistic change in Kandinsky and Mondrian paintings – A Comparative Analytic study-" deals with the nature of change concept, its mechanisms and its constructive disciplines. The research has four chapters: The first chapter deals with the methodological Framework represented by the problem of the research which is concerned with the stylistic change and its role in activating formative disciplines.                                   The research aims at, finding out the stylistic change in Kandinsky and Mondrian Paintings.&

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 02 2017
Journal Name
Journal Of Educational And Psychological Researches
Bayer effective strategy in the development of deductive thinking when students fifth grade literary material in history
...Show More Authors

Supervised By : Prof. dr. Shaker Jaseem Mohammed This research aims to identify the (effectiveness of Bayer's strategy in the development of deductive thinking among students in the fifth grade literary material European history) and to achieve the goal set researcher null hypothesis of the following: • There is no statistically significant difference between the average scores of the experimental group which studied the use of Bayer's strategy and the control group, which studied the use of the usual way in the development of deductive reasoning. The study sample consisted of (84 students) of the students in the fifth grade literary breeding Baghdad / Karkh second Directorate for the academic year 2015-2016 were distributed Aanhaldras

... Show More
View Publication Preview PDF
Publication Date
Sun Jun 30 2019
Journal Name
Journal Of Engineering
Thermal Performance of Plastic Receiver in Solar Collector
...Show More Authors

A plastic tubes used as absorber of active flat plate solar collector (FPSC) for heating water were studied numerically and experimentally. The set-up is located in Babylon (republic of Iraq) 43.80 East longitude and 32.30 North latitude with titled of 450 toward the south direction.  The study involved three dimensions mathematical model for flat coil plastic absorber which solved by FLUENT-ANSYS-R.18 program. Experiments were conducted at outdoor conditions for clear days on January and February 2018 with various water volume flow rates namely (500, 750, 1000, 1250, and 1500 Liter per hour LPH) on each month for Reynolds number range of (1 x 104 to 5 x 104) th

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Aug 30 2025
Journal Name
مجلة منوال للدراسات التربوية والنفسية
The Negative Impact of Media on the Educational Identity of Society
...Show More Authors

This research aims the effects of negative media on the educational identity of community. Whereas display the concept of educational identity and its basic components, as well as the role of educational institutions for example the school and the family in form it and reinforcing this identity to individuals. The study showcasing the harmful impact of both traditional and modern media on identity and values, spotlight several examples like the promotion of consumerism and materialism through television programs. which results in the young people to adopt materialistic values like simplicity. The study concludes that media is a double-edged weapon: it can instill virtues and support education if used duly, but it can also weaken the educat

... Show More
View Publication Preview PDF