Preferred Language
Articles
/
joe-928
Numerical Study of Fluid Flow and Heat Transfer Characteristics in Solid and Perforated Finned Heat Sinks Utilizing a Piezoelectric Fan
...Show More Authors

Numerical study is adapted to combine between piezoelectric fan as a turbulent air flow generator and perforated finned heat sinks. A single piezoelectric fan with different tip amplitudes placed eccentrically at the duct entrance. The problem of solid and perforated finned heat sinks is solved and analyzed numerically by using Ansys 17.2 fluent, and solving three dimensional energy and Navier–Stokes equations that set with RNG based k−ε scalable wall function turbulent model. Finite volume algorithm is used to solve both phases of solid and fluid. Calculations are done for three values of piezoelectric fan amplitudes 25 mm, 30 mm, and 40 mm, respectively. Results of this numerical study are compared with previous both numerical and experimental studies and give a good agreement. Numerical solution is invoked to explain the behavior of air flow and temperature distribution for two types of circular axial and lateral perforations. For each type, all the results are compared with an identical solid finned heat sink. Perforations show a remarkable enhanced in the heat transfer characteristics. The results achieved enhancement in the heat transfer coefficient about 12% in axial perforation and 25% in the lateral perforation at the maximum fan amplitude.

 

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Apr 01 2014
Journal Name
Journal Of Economics And Administrative Sciences
Developing a Learning Organization According to Analysis of the Relationship between Knowledge Gap and Strategic Performance Gaps: Field Study in a Sample of Private Banks in Baghdad.
...Show More Authors

The purpose of this research shed light on the analysis of the relationship between the knowledge gap and the strategic performance  gap and diagnose the level of impact this relationship in building a learning organization, and sought search to achieve a number of goals, cognitive and Applied been tested nature of the relationship and effect between variables in a sample size (62) of the managers of banks civil in Baghdad (Baghdad, Gulf, Assyria, Union, Elaf) and focused research problem in question is bold is whether the analysis of the relationship between the knowledge gap and the performance gap strategic leads to recognize organizations need to shift to organizations educated, either in the side of the field was the pr

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Mar 13 2011
Journal Name
Baghdad Science Journal
In Vivo Toxicity Study of Nerium oleander's Leaves and Flowers Aqueous Extracts in Mice (Cytogenetic, Biochemical and Hematological Study)
...Show More Authors

The present research was carried out to assess the toxic effect of oral administration of the aqueous extract of Nerium oleander leaves and flowers daily at doses of (25) mg/kg body weight for four weeks in mice. The toxicity of this plant parts was determined after two and four weeks by measuring the parameters of cytogenetic (mitotic index, micronucleus %), and serum levels of the hematological (RBC, Hb, WBC) and biochemical (GOT, GPT, ALT, AST) indexes in comparison with that of the control (normal saline), also clinical signs were determined. The results showed a significant decrease in mitotic index while an obvious raise was seen in micronucleus percentage in comparison with that of the control after the two periods of admini

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Mon May 01 2017
Journal Name
Desalination And Water Treatment
Cadmium removal from simulated chloride wastewater using a novel flow-by fixed bed electrochemical reactor: Taguchi approach
...Show More Authors

View Publication
Scopus (10)
Crossref (7)
Scopus Clarivate Crossref
Publication Date
Wed Jan 01 2025
Journal Name
Iraqi Journal Of Applied Physics
Structural and Morphological Characteristics of PEKK-Coated Titanium Disks by RF Magnetron Sputtering for Implant Osteointegration Application
...Show More Authors

Pure grade II titanium disks were coated with a thin coating of polyetherketoneketone (PEKK) polymer by RF magnetron sputtering using either nitrogen or argon gas. Sputtering technique was employed at 50 W for one hour at 60°C with continuous flow of nitrogen or argon gas. Field-emission scanning electron microscopy (FE-SEM) showed a continuous, homogeneous, rough PEKK surface coating without cracks. In addition, cross-sectional FE-SEM revealed an average coat thickness of 1.86 μm with argon gas and 1.96 μm with nitrogen gas. There was homogenous adhesion between the coating layer and substrate. The elemental analysis of titanium substrate revealed the presence of carbon, titanium, and oxygen. The RF magnetron sputtering with argon or ni

... Show More
Preview PDF
Publication Date
Wed Dec 01 2010
Journal Name
Iraqi Journal Of Physics
Current–voltage and capacitance-voltage characteristics of Se/Si heterojunction prepared by DC planar magnetron sputtering technique
...Show More Authors

In this work, the effect of annealing temperature on the electrical properties are studied of p-Se/ n-Si solar cell, which p-Se are deposit by DC planar magnetron sputtering technique on crystal silicon. The chamber was pumped down to 2×10−5 mbar before admitting the gas in. The gas was Ar. The sputtering pressure varied within the range of 4x10-1 - 8x10-2mbar by adjusting the pumping speed through the opening control of throttle valve. The electrical properties are included the C-V and I-V measurements. From C-V measurements, the Vbi are calculated while from I-V measurements, the efficiency of solar cell is calculated.

View Publication Preview PDF
Publication Date
Tue Jun 30 2015
Journal Name
Al-khwarizmi Engineering Journal
Studying and Modeling the Effect of Graphite Powder Mixing Electrical Discharge Machining on the Main Process Characteristics
...Show More Authors

Abstract

This paper concerned with study the effect of a graphite micro powder mixed in the kerosene dielectric fluid during powder mixing electric discharge machining (PMEDM) of high carbon high chromium AISI D2 steel. The type of electrode (copper and graphite), the pulse current and the pulse-on time and mixing powder in kerosene dielectric fluid are taken as the process main input parameters. The material removal rate MRR, the tool wear ratio TWR and the work piece surface roughness (SR) are taken as output parameters to measure the process performance. The experiments are planned using response surface methodology (RSM) design procedure. Empirical models are developed for MRR, TWR and SR, using the analysis

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 01 2022
Journal Name
Canadian Journal Of Chemistry
Hydrogenation of pyridine and hydrogenolysis of piperidine over $γ$-Mo2N catalyst: a DFT study
...Show More Authors

Increasing demands on producing environmentally friendly products are becoming a driving force for designing highly active catalysts. Thus, surfaces that efficiently catalyse the nitrogen reduction reactions are greatly sought in moderating air-pollutant emissions. This contribution aims to computationally investigate the hydrodenitrogenation (HDN) networks of pyridine over the γ-Mo2N(111) surface using a density functional theory (DFT) approach. Various adsorption configurations have been considered for the molecularly adsorbed pyridine. Findings indicate that pyridine can be adsorbed via side-on and end-on modes in six geometries in which one adsorption site is revealed to have the lowest adsorption energy (–45.3 kcal/mol). Over a nitr

... Show More
Publication Date
Wed Oct 03 2012
Journal Name
Journal Of Kufa For Chemical Science
A study of Adsorption of Acetone and 2- Butanone on Iraqi Siliceouns Rocks Powder
...Show More Authors

Adsorption of Acetone and 2-Butanone on Iraqi siliceouns rocks powder have been investigated. UV technique has been used to determine the adsorption isotherms. The results showed that the adsorption isotherms obeyed Freundlich adsorption equation. The results showed that the adsorption increases with increasing acidity of solutions. The adsorption was exothermic process, increasing temperature leads to decreasing adsorption. H,  S, G were calculated

Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
A study of the Effect of Air Inlet and Exit on Indoor Air Movement
...Show More Authors

This work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated  from burnt herbs and collected in a smoke generator to delivered through

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Feb 12 2019
Journal Name
Iraqi Journal Of Physics
A study of the structural and electrical properties of Ni1-x Cox Fe2O4 ferrites
...Show More Authors

Ferrite with general formula Ni1-x Cox Fe2O4(where x=0.0.1,0.3,0.5,0.7, and 0.9), were prepared by standard ceramic technique. The main cubic spinel structure phase for all samples was confirmed by x-ray diffraction patterns. The lattice parameter results were (8.256-8.299 °A). Generally, x -ray density increased with the addition of Cobalt and showed value between (5.452-5.538gm/cm3). Atomic Force Microscopy (AFM) showed that the average grain size and surface roughness was decreasing with the increasing cobalt concentration. Scanning Electron Microscopy images show that grains had an irregular distribution and irregular shape. The A.C conductivity was found to increase with the frequency and the addition of Cobal

... Show More
View Publication Preview PDF
Crossref (1)
Crossref