Preferred Language
Articles
/
alkej-625
Investigation of heat transfer phenomena and flow behavior around electronic chip
...Show More Authors

Computational study of three-dimensional laminar and turbulent flows around electronic chip (heat source) located on a printed circuit board are presented. Computational field involves the solution of elliptic partial differential equations for conservation of mass, momentum, energy, turbulent energy, and its dissipation rate in finite volume form. The k-ε turbulent model was used with the wall function concept near the walls to treat of turbulence effects. The SIMPLE algorithm was selected in this work. The chip is cooled by an external flow of air. The goals of this investigation are to investigate the heat transfer phenomena of electronic chip located in enclosure and how we arrive to optimum level for cooling of this chip. These parameters, which will help enhance thermal performance of electronic chip and flow patterns, through the understanding of different factors on flow patterns. The results show the relation between the temperature rise, heat transfer parameters (Nu, Ra) with (Ar, Q) for two cases of laminar and turbulent flows.

View Publication Preview PDF
Quick Preview PDF
Publication Date
Sat Dec 02 2023
Journal Name
Journal Of Engineering
The Cost of Technology Transfer in Construction Companies (In Iraq)
...Show More Authors

The construction sector is considered an important and influential pivot in the national economy of any country.  Nations are working to develop this sector, receiving modern and developed techniques. So, this sector can be a carrier or a receiver of modern technologies. The cost of technology transfer between the international companies that sponsor this sector is a matter of great importance, especially since different factors affect the need for this advanced technology. The cost of technology transfer in construction is related to multiple factors presented by Knowledge, equipment, plant, hardware and software. The lack of distinguishing and evaluating the direct and indirect costs in the construction sector during

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Feb 14 2023
Journal Name
Journal Of Educational And Psychological Researches
Negotiation Behavior and Its Relationship to Some Variables of Administrative Teachers
...Show More Authors

Abstract

The current research aims to identify the negotiation behavior of administrative teachers, as well as to identify the significance of the differences in negotiation behavior according to the variables (gender, scientific title, length of service). After confirming the psychometric characteristics of (20) items, the researchers applied the scale to (400) male and female administrative teaching staff who were randomly selected from the University of Baghdad for the academic year 2021/2022. The results showed the following the research sample has a negotiating behavior. There are no statistically significant differences between gender, scientific title, and length of service in the means of negotiating beha

... Show More
View Publication Preview PDF
Publication Date
Wed Mar 01 2023
Journal Name
Iraqi Journal Of Physics
FTIR and Electrical Behavior of Blend Electrolytes Based on (PVA/PVP)
...Show More Authors

Polymer electrolytes were prepared using the solution cast technology. Under some conditions, the electrolyte content of polymers was analyzed in constant percent of PVA/PVP (50:50), ethylene carbonate (EC), and propylene carbonate (PC) (1:1) with different proportions of potassium iodide (KI) (10, 20, 30, 40, 50 wt%) and iodine (I2) = 10 wt% of salt. Fourier Transmission Infrared (FTIR) studies confirmed the complex formation of polymer blends. Electrical conductivity was calculated with an impedance analyzer in the frequency range 50 Hz–1MHz and in the temperature range 293–343 K. The highest electrical conductivity value of 5.3 × 10-3 (S/cm) was observed for electrolytes with 50 wt% KI concentration at room

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Materials Today
Behavior of RC columns strengthened by combined (CFRP and steel jacket)
...Show More Authors

Scopus (15)
Crossref (8)
Scopus Clarivate Crossref
Publication Date
Fri Apr 01 2016
Journal Name
Al–bahith Al–a'alami
The Electronic Advertising War Among the International Trading Companies
...Show More Authors

The use of the word “war” alone raises horror and fear in the hearts of the recipients, especially if this war aimed at human’s life, his health and his future. It is the electronic advertising war among rival international companies that use cyberspace to create fear and horror in the hearts of the recipients because it connects the use of the product with human’s death or serious illness.
The problem of this research sheds light on the new uses of cyberspace which fucked by international companies to strike the interests of each other by displaying the defects of their products and its negative impact on citizen’s life. Despite the fact that those wars have opposed strongly, there are supporters for those wars. Their argu

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Mar 01 2021
Journal Name
Iraqi Journal Of Physics
Investigation of Structural, Mechanical, Thermal and Optical Properties of Cu Doped TiO2
...Show More Authors

In this work, Pure and Cu: doped titanium dioxide nano-powder was prepared through a solid-state method. the dopant concentration [Cu/TiO2 in atomic percentage (wt%)] is derived from 0 to 7 wt.%. structural properties of the samples performed with XRD revealed all nanopowders are of titanium dioxide having polycrystalline nature. Physical and Morphological studies were conducted using a scanning electronic microscope SEM test instrument to confirm the grain size and texture. The other properties of samples were examined using an optical microscope, Lee's Disc, Shore D hardness instrument, Fourier-transform infrared spectroscopy (FTIR), and Energy-dispersive X-ray spectroscopy (EDX). Results showed that the thermal conductivity

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Mon Jan 01 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Science
Investigation of the Structural, Optical and Electrical Properties of AgInSe2 Thin Films
...Show More Authors

Publication Date
Wed Dec 18 2019
Journal Name
Bulletin Of Materials Science
Investigation of optical properties and glass transition temperature of nano-epoxy matrix
...Show More Authors

View Publication
Scopus (2)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Thu May 18 2023
Journal Name
Journal Of Engineering
Theoritical and Experimental Investigation of the Dynamical Behaviour of Complex Configuration Rotors
...Show More Authors

The present work considers an alternative solution for a complex configuration of rotor discs by applying Galerkin Method. The theoretical model consists of elastic shaft carrying number of discs and supported on number of journal bearings. The equation of motion was discretized to finite degree of freedom in terms of the system generalized coordinates. The various effects of the dynamical forces and moments arising from the bearing, discs and shaft were included. Rayleigh beam model is used for analyzing the shaft while the discs are considered rigid . The validity and convergence of the present analysis was carefully checked by comparing with the Finite Element solution. An example of rotor consists of three different size discs and su

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue May 01 2012
Journal Name
Iraqi Journal Of Physics
Nano-Scale core effects on electronic structure properties of gallium arsenide
...Show More Authors

Ab – initio density function theory (DFT) calculations coupled with Large Unit Cell (LUC) method were carried out to evaluate the electronic structure properties of III-V zinc blend (GaAs). The nano – scale that have dimension (1.56-2.04)nm. The Gaussian 03 computational packages has been employed through out this study to compute the electronic properties include lattice constant, energy gap, valence and conduction band width, total energy, cohesive energy and density of state etc. Results show that the total energy and energy gap are decreasing with increase the size of nano crystal . Results revealed that electronic properties converge to some limit as the size of LUC increase .

View Publication Preview PDF