Preferred Language
Articles
/
joe-235
Numerical Study of Heat Transfer Enhancement in Heat Exchanger Using AL2O3 Nanofluids
...Show More Authors

In this study, the flow and heat transfer characteristics of Al2O3-water nanofluids for a range of the Reynolds number of 3000, 4500, 6000 and 7500 with a range of volume concentration of 1%, 2%, 3% and 4% are studied numerically. The test rig consists of cold liquid loop, hot liquid loop and the test section which is counter flow double pipe heat exchanger with 1m length. The inner tube is made of smooth copper with diameter of 15mm. The outer tube is made of smooth copper with diameter of 50mm. The hot liquid flows through the outer tube and the cold liquid (or nanofluid) flow through the inner tube. The boundary condition of this study is thermally insulated the outer wall with uniform velocity at (0.2, 0.3, 0.4 and 0.5 m/s) at the cold loop and constant velocity at (0.5 m/s) at the hot loop.

The results show that the heat transfer coefficient and Nusselt number increased by increasing Reynolds number and particle concentration. Numerical results indicate that the maximum enhancement in Nusselt number and heat transfer coefficient were 9.5% and 13.5% respectively at Reynolds number of 7100 and particles volume fraction of 4%. Results of nanofluids also showed a good agreement with the available empirical correlation at particles volume fractions of 1%, 2% and 3%, but at volume fractions of 4% a slight deviation is obtained.

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Tue Dec 15 2020
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of ageing media on shear bond strength of metal orthodontic brackets bonded with different adhesive systems (A comparative in-vitro study)
...Show More Authors

Background: The aim of this study was to evaluate the shear bond strength (SBS) and adhesive remnant index (ARI) of different orthodontic adhesive systems after exposure to aging media (water storage and acid challenge). Materials and methods: Eighty human upper premolar teeth were extracted for orthodontic purposes and randomly divided into two groups (40 teeth each): the first group in which the bonded teeth were stored in distilled water for 30 days at 37°C, and the second group in which the bonded teeth were subjected to acid challenge. Each group was further subdivided into four subgroups (10 teeth each) according to the type of adhesive system that would be bonded to metal brackets: either non-fluoride releasing adhesive (NFRA),

... Show More
View Publication Preview PDF
Scopus (5)
Crossref (4)
Scopus Crossref
Publication Date
Mon Mar 09 2026
Journal Name
Journal Of Baghdad College Of Dentistry
An Evaluation of Some Mechanical Properties of Autopolymerizing Acrylic Resin with the Modified One after Changing the Curing Environment: (In vitro Study)
...Show More Authors

Background: Studying and investigating the transverse strength(Ts), impact strength(Is), hardness (Hr) and surface roughness(Ra) of conventional and modified autopolymerizing acrylic resin with different weight percentages of biopolymer kraftlignin, after curing in different water temperatures; 40°C and 80°C. Material and Methods: Standard acrylic specimens were fabricated according to ADA specification No.12 for transverse strength, ISO 179 was used for impact testing, Shore D for hardness and profilometerfor surface roughness. The material lignin first dispersed in the monomer, then the powder PMMA is immediately added. Ligninadded in different weight percentages. Then cured using pressure pot (Ivomet) in two temperatures;40°C a

... Show More
View Publication Preview PDF
Publication Date
Mon Mar 13 2017
Journal Name
Journal Of Baghdad College Of Dentistry
The Effect of Artificial Accelerated Aging on The Color of Ceramic Veneers Cemented With Different Resin Cements (A Comparative In Vitro Study)
...Show More Authors

ABSTRACT Background: Color changes that are detectable to human eye can affect the esthetic appearance of ceramic veneers. The purpose of this study was to evaluate and compare the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements. Materials and Methods: Sixty discs were prepared with 0.5 mm thickness, 30 discs made from IPS e.max press (Ivoclar Vivadent) and 30 discs were made from VITA Enamic (VITA Zahnfabrik). The discs were cemented with three resin cements: Variolink Veneer MV 0 shade (Ivoclar Vivadent), Rely X veneer Translucent shade (3M ESPE) and NX3 Nexus Clear shade (Kerr Corporation) with 0.1 mm thickness. The spectrophotometer Easyshade Advance was used to measure the co

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Tue Dec 26 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
A Comparative Study of Blood Levels of Manganese, Some Macroelements and Heavy Metals in Obese and Non-Obese Polycystic Ovary Syndrome Patients
...Show More Authors

Polycystic ovary syndrome (PCOS) is a prevalent condition in women of reproductive age. It is characterized by androgen excess and chronic anovulation. Some trace elements, macroelements, and heavy metals have been linked to pathophysiological mechanisms of PCOS .

To study the alterations in the serum levels of the trace element manganese (Mn), some macroelements, magnesium(Mg) and calcium (Ca), and the heavy metals cadmium (Cd) and lead (Pb), in obese and non-obese PCOS patients; and the association of these alterations with some of the hormonal changes occurring in PCOS.

The study was carried out at Kamal Al-Samarrai Hospital (Center for Infertility treatment and in vitro Fertilization "IVF") Baghdad- Iraq. Eig

... Show More
View Publication Preview PDF
Crossref (5)
Crossref
Publication Date
Sun Jan 01 2023
Journal Name
Journal Of Clinical And Experimental Dentistry
Preventive effect of combined Er, Cr: YSGG and fluoride gel on acid resistance of the permanent tooth enamel: An in vitro study
...Show More Authors

View Publication
Crossref (5)
Crossref
Publication Date
Fri Jan 01 2016
Journal Name
Al–bahith Al–a'alami
The Influence of Turkish Soap Operas in the Behavior and Trends of the Iraqi Audience (A Field Study on Iraqi University's Students)
...Show More Authors

This research seeks the effects of dubbed Turkish TV series on Iraqi audiences. The chosen sample is about 600 Iraqi students at Baghdad and al-Anbar Universities. This study consists of four sections: section one deals with the theoretical framework of the study. Section two studies the dubbed Turkish TV series. The third section explores the role of mass media in forming tendencies, and the last section seeks the field study by analyzing the tendencies if Iraqi viewers of these series.
The goal of this study is to know the role these series played in affecting the behavior and attitudes of Iraqi people and how it can change their morals.
The research ends with the number of results like the negative effect of these series on the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Sep 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Business Process Re-engineering and its Role of Achieving Competitive Advantage: An application study in the State Company of Vegetable Oil Industry
...Show More Authors

The business process re-engineering is one of the popular concepts at this time because its provide a radical solution for the problems that companies faces. This method appeared because the changes of competition and costumers 'desires at the two last decades. The markets become wider because of the globalization so the companies must change its way to stay a life.

        The research aim is to concentrate on the  BPR  because it's a  philosophy aims to re-organize the company's business process to achieve the competitive advantage, the research also aims to a plicate  the BPR using cost management technique  in the State Company of Vegetable Oils Industry.

&nb

... Show More
View Publication Preview PDF
Publication Date
Wed Jun 29 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
A Comparison Study for The Performance of Polyethersulfone Ultrafiltration Mixed Matrix Membranes in The Removal of Heavy Metal Ions from Aqueous Solutions
...Show More Authors

Polyethersulfone (PES) ultrafiltration membrane blending NaX zeolite crystals as a hydrophilic additive was examined for zinc (II) and lead ions Pb (II) removal from aqueous solutions. The effect of NaX zeolite content on the permeation flux and removal efficiency was studied. The results showed that adding zeolite to the polymer matrix enhanced the permeation flux. The permeation flux of all the zeolite/PES matrix membranes was higher than the pristine membrane. No significant improvement was observed in the removal of Zn (II) ions using all prepared membranes as the removal percentage did not raise above 29.2%. However, the removal percentage of Pb (II) ions was enhanced to 97% using a membrane containing 0.9%wt. zeolite. Also, it was

... Show More
View Publication Preview PDF
Crossref (7)
Crossref
Publication Date
Fri Mar 01 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The Relationship Between Competitive Intelligence and Entrepreneurial Performance By Centralizing Strategic Vigilance: Field study of a sample of National colleges in Iraq
...Show More Authors

The aim of this study is to highlight the relationship between competitive intelligence and Entrepreneurial Performance by centralizing the strategic vigilance of a sample of civil faculties in Baghdad. The sample of the study was targeted at 10 Iraqi civil colleges, which consisted of (133) members of the faculty council of the faculties, the search data was collected using the questionnaire form as the main research tool. The results showed that the correlation and influence of competitive intelligence and strategic vigilance in the Entrepreneurial Performance, as well as the role of strategic vigilance as an intermediate variable between competitive intelligence and Entrepreneurial Performance.

View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Electronic trading system and its refletion in the trading of stock market indices –an analytical study of the Iraqi market for securities–
...Show More Authors

The research aims at identify the role of the electronic trading system used in the Iraq stock exchange to promote trading activity for the stocks of listed companies in this market.

To prove the hypothesis of research, it was selected the main trading indicators for the market to be a main field in test the research hypothesis.it was selected as the period of time for (9)years span between the years (2005-2013) because they represent the first two articles of equal time periods represent aperiod that preceded the introduction of electronic trading system  while the second represents the period of time that followed 

The research found a number of conclusions but the mo

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