Preferred Language
Articles
/
alkej-598
Studying the Effect of Volume Fraction of Glass Fibers on the Thermal Conductivity of the Polymer Composite Materials
...Show More Authors

In this study the effect of fiber volume fraction of the glass fiber on the thermal conductivity of the polymer composite material was studied. Different fiber volume fraction of glass fibers were used (3%, 6%, 9%, 12%, and 15%). Specimens were made from polyester which reinforced with glass fibers .The fibers had two arrangements according to the direction of the thermal flow. In the first arrangement the fibers were parallel to the direction of the thermal flow, while the second arrangement was perpendicular; Lee's disk method was used for testing the specimens. The experimental results proved that the values of the thermal conductivity of the specimens was higher when the fibers arranged in parallel direction than that when the fibers arranged in the perpendicular direction. The percentage of increasing of experimental thermal conductivity was 96.91% for parallel arrangement and 13.33% for perpendicular arrangement comparison with its original value before the using of glass fibers.

Also the experimental results indicated that the thermal conductivity increases with the increasing of the fiber volume fraction. Minimum value was (0.172 W/m.°C) for perpendicular arrangement at fiber volume fraction 3% and maximum value was (0.327 W/m.°C) for parallel arrangement at fiber volume fraction 15%.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
Effect of CO2 Laser Irradiation on the Topographic and Optical Properties of CdO Thin Films
...Show More Authors

     In this study, cadmium oxide (CdO) was deposited on glass bases by thermal chemical spraying technique at three concentrations (0.05, 0.1, 0.15) M and then was irradiated by CO2 laser with 10.6 μm wave length and 1W power. The results of the atomic force microscope AFM test showed that the surfaces of these CdO thin films were homogenous and that the laser irradiated effect resulted in decreasing the roughness of the surface as well as the heights of the granular peaks, indicating a greater uniformity and homogeneity of the surfaces. The optical properties were studied to determine laser effect. The results of optical tests of these thin films showed that the photoluminescence spectra and absorption s

... Show More
View Publication Preview PDF
Scopus (7)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The effect of performance appraisal dimensions On organization confidence
...Show More Authors

This research was designed to study effect of performance appraisal dimensions on organizational confidence.

Asset completion questionnaire was used to collect data of this research from a random simple represent forty employees who works in Iraqi Oil ministry. The main result of this research was positive relations and the effect between performance appraisal and organizational confidence. The research contains some conclusions, the main of it is unimplemented the performance appraisal results in the policies of employees in the ministry and it work in classic methods incentives and training.

The important recommendations must doing to achieve integrating between the result of pe

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Al-khwarizmi Engineering Journal
Experimental and Numerical Investigation for Simulation of Thermophysical Properties for Polypropylene 575 Polymer Melts in Single Screw Extruder
...Show More Authors

A numerical model for Polypropylene 575 polymer melts flow along the solid conveying screw of a single screw extruder under constant heat flux using ANSYS-FLUENT 17.2 software has been conducted. The model uses the thermophysical properties such as Viscosity, thermal conductivity, Specific heat and density of polypropylene 575 that measured as a function of temperature, and residence time data for process simulation. The numerical simulation using CFD models for single screw extruder and the polymer extrusion was analysed for parameters such as (thermal conductivity, specific heat, density and viscosity) reveals a high degree of similarity to experimental data measured. The most important outcome of this study is that geometrical, parame

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 23 2018
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Dividend Policy on Earnings Quality in The Companies listed in Iraq Stock Exchange
...Show More Authors

The dividends is one of difficult and important decisions taken by the administration in the economic units, because this decision has a direct impact on the investor and economic unit, so the main objective of any investor is achieve earnings, as well as information borne by dividends about the earnings quality of the economic unit and the level and efficiency of management to achieving earnings.

The research aims at explaining the effect of the dividends policy on the earnings quality in the companies listed in the Iraq Stock Exchange. The Miller model was used to measu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Aug 15 2023
Journal Name
Sumer 1
The effect of silver diamine fluoride on the microleakage of glass ionomer restoration in primary teeth at different time intervals
...Show More Authors

Silver diamine fluoride (SDF) has shown effectiveness in hardening tooth structure and killing bacteria. Therefore, it can be used to prevent and arrest dental caries. Riva Star (SDF) treatment alone will stop cavities but will not reverse the cavitation. The Silver Modified Atraumatic Procedure, often known as Smart, is the optimum technique for regaining the tooth's structure and function. Glass ionomer was introduced in (1972) as a new material that has become one of the most widely used materials in restorative dentistry. By releasing fluoride ions, this material has a therapeutic impact on the surrounding tooth structure. Microleakage is the ingress of bacteria, its byproducts, toxins, chemicals, oral fluids, and ions between t

... Show More
View Publication
Scopus (5)
Crossref (2)
Scopus Crossref
Publication Date
Wed Sep 30 2020
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Studying Thermal Cracking Behavior of Vacuum Residue
...Show More Authors

   In the oil industry, the processing of vacuum residue has an important economic and environmental benefit. This work aims to produce industrial petroleum coke with light fuel fractions (gasoline, kerosene , gas oil) as the main product and de asphalted oil (DAO) as a side production from treatment secondary product matter of vacuum residue. Vacuum residue was produced from the bottom of vacuum distillation unit of the crude oil. Experimentally, the study investigated the effect of the thermal conversion process on (vacuum residue) as a raw material at temperature reaches to 500 °C, pressure 20 atm. and residence time for about 3 hours. The first step of this treatment is constructing a carbon steel batch re

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Thu Aug 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Effect of the application of IFRS 15 "Revenue from contracts with customers" on the quality of financial reporting
...Show More Authors

Abstract

This study aims at identifying the impact of the application of IFRS 15 "Revenue from contracts with customers on the quality of financial reporting, through application to faculty members in the accounting departments of Iraqi universities and auditors. The problem of the study was the multiplicity of accounting rules and standards Which deals with the issues of revenue recognition , as well as the lack of consistency of most of them with the common framework of financial accounting, which results in low quality of financial reporting in the current financial statements, where the formulation of one hypothesis was the lack of relationship of significant significance The application of IFRS 15 "Recognition of rev

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Jan 01 2011
Journal Name
Iraqi Journal Of Physics
Dielectric Waveguide for Composite Materials
...Show More Authors

The Maxwell equations have been formulated for a composite slab waveguide at x-band wave propagation. The eigenvalues of the system equations are obtained by using MATLAB program. These eigenvalues are used to obtain the wave propagation constant and a number of modes inside the slabs. A good correspondence was seen between the number of modes and the cut off thickness. The parameter that affects the performance of waveguide is the slab thickness. The propagation constant is usually adopted to characterize this type of waveguide and show how the cutoff frequency of the mode in the slab is increased dramatically by decreasing the frequency.
Our study focused on lower modes, the results for the transmission coefficient are then used to

... Show More
View Publication Preview PDF
Publication Date
Fri Aug 20 2021
Journal Name
Iraqi Journal Of Laser
The Influence of No-Core Fiber Length on the Sensitivity in Fiber Optic Strain Sensor
...Show More Authors

The influence of sensing element length of no-core fiber strain sensor has been studied and experimentally demonstrated, four different lengths of 125 μm diameter no-core fiber is fused between two standard single-mode fibers and bi-directionally strained, the highest obtained sensitivity was around 16.37 pm με -1 which was exhibited in the shortest no-core fiber segment, to the best of our knowledge this is the first study of the influence of no-core fiber strain sensors length on sensor sensitivity. The proposed sensor can be used in many opto-mechanical applications such as, structural health monitoring, aerospace vehicles and airplane components monitoring.

View Publication Preview PDF
Publication Date
Thu Nov 08 2018
Journal Name
Iraqi National Journal Of Nursing Specialties
Studying the Effect of Different Separating Medium on the Roughness of the tissue surface of Acrylic Denture Base (In Vitro Study)
...Show More Authors

Objective: In order to evaluate the effect of different typed of Separating Medium on the roughness of the fitted
tissue surface of acrylic denture base.
Methodology: Chosen three types of separating medium (Group A Tin foil), (Group B Detery Isolant),(Group C
Cold Mould Seal),used 30 samples of hot cure acrylic resin ,10 samples for each group, after complete curing of
these samples , Profilometer device was used to measure the surface roughness of each sample in all groups.
Results: Using One Way ANOVA Test and LSD test, the results were highly significant in differences among all
groups. Although (Group A) showing lest roughness, (Group B) showing a satisfactory result of roughness, While
(Group C) Showing the hig

... Show More
View Publication Preview PDF