Preferred Language
Articles
/
alkej-24
The Effect of Restriction Shape On Laminar Natural Convection Heat Transfer In A Vertical Circular Tube
...Show More Authors

Natural convection heat transfer is experimentally investigated for laminar air flow in a vertical circular tube by using the boundary condition of constant wall heat flux in the ranges of (RaL) from (1.1*109) to (4.7*109). The experimental set-up was designed for determining the effect of different types of restrictions placed at entry of heated tube in bottom position, on the surface temperature distribution and on the local and average heat transfer coefficients. The apparatus was made with an electrically heated cylinder of a length (900mm) and diameter (30mm). The entry restrictions were included a circular tube of same diameter as the heated cylinder but with lengths of (60cm, 120cm), sharp-edge and bell-mouth. The surface temperature along the cylinder surface for same heat flux would be higher values for circular restriction with length of (120cm) and would be smaller values for bell-mouth restriction. The results show that the local Nusselt number (Nux) and average Nusselt numberare higher for bell-mouth restriction and smaller values for (120cm) restriction. For all entry shape restrictions, the results show that the Nusselt number values increases as the heat flux increases. From the present work an empirical correlations were obtained in a form of (Log) versus (Log) for each case investigated and obtained a general correlation for all cases which reveals the effect of restriction existence on the natural convection heat transfer process in a vertical circular tube.

 

View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Mar 02 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Antibacterial effect of cardamom and black tea aqueous extract on mutans streptococci in comparison to chlorhexidine (in vitro study)
...Show More Authors

Background: Antimicrobial agents have been considered as having potential for the prevention of dental caries. This study aimed to test the effect of different concentrations of cardamom and black tea extracts on the sensitivity and growth of salivary mutans streptococci in comparison to chlorhexidine gluconate (0.2%) in vitro. Materials and methods: In this study. Mutans streptococci were isolated from saliva of 34 healthy people (aged between 22-40yrs). The bacteria was isolated, purifiedand diagnosed according to morphologicalcharacteristic and biochemical tests. Aqueous extracts of cardamom and black tea were prepared. Different concentrations of extracts were prepared and estimated in gm/ 100ml deionized water. The agar diffusion techn

... Show More
View Publication Preview PDF
Publication Date
Fri Feb 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
A Standard Study of the Role of the Tourism Sector in Achieving Economic Growth in Tunisia for the Period (1995-2017
...Show More Authors

This study examines the relationship between the increase in the number of tourists coming to Tunisia and GDP during the period 1995-2017, using the methodology of joint integration, causal testing and error correction model. The research found the time series instability of the logarithm of the number of tourists coming to Tunisia and the output logarithm but after applying the first differences, these chains become stable, THUS these time series are integrated in the first differences. Using the Johansson method, we found the possibility of a simultaneous integration relationship between the logarithm of the number of tourists coming to Tunisia and the logarithm of GDP in Tunisia, and there is a causal relationship in one direc

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 25 2023
Journal Name
Optical Materials
Impact of a precise pH value change on the characteristics of deposited tin monosulphide films onto a flexible substrate
...Show More Authors

The chemical bath deposition technique (CBD) is considered the cheapest and easiest compared with other deposition techniques. However, it is highly sensitive to effective parameter deposition values such as pH, temperature, and so on. The pH value of the reaction solution has a direct impact on both the nucleation and growth rate of the film. Consequently, this study presents a novel investigation into the effect of a precise change. in the pH reaction solution value on the structural, morphological, and photoresponse characteristics of tin monosulphide (SnS) films. The films were grown on a flexible polyester substrate with pH values of 7.1, 7.4, and 7.7. The X-ray diffraction patterns of the grown films at pH 7.1 and 7.4 confirmed

... Show More
Preview PDF
Publication Date
Sat Jun 01 2013
Journal Name
Journal Of Economics And Administrative Sciences
Impact of the global financial crisis on the efficiency of activity of the Iraqi Stock Market, "An Empirical Study for the period 2006-2008”
...Show More Authors

Abstract
  financial market occupy very important place in the economic activity all over the world countris, and its importance increased with considerable technological progress in the world of transportation ,communications and information where its impact have spread over the whole world, which led to link the international economy in a kind of international relations so that the open policy became the prevailing trend in national and regional economies within the framework of the new world order.

the international economy has faced the financial crisis, global, that hit all world economies although the United States is the center of the crisis and the starting spark for it w

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Oct 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Time-Cost Trade-off to Manage A Project in a Fuzzy Environment
...Show More Authors

In this research, the problem of ambiguity of the data for the project of establishing the typical reform complex in Basrah Governorate was eliminated. The blurry of the data represented by the time and cost of the activities was eliminated by using the Ranking function and converting them into normal numbers. Scheduling and managing the Project in the Critical Pathway (CPM) method to find the project completion time in normal conditions in the presence of non-traditional relationships between the activities and the existence of the lead and lag periods. The MS Project was used to find the critical path. The results showed that the project completion time (1309.5) dinars and the total cost has reached (33113017769) dinars and the

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jun 03 2012
Journal Name
Baghdad Science Journal
Study the effect of polyphenols extracted from Iraqi grape seeds on glucose , MDA levels and GST activity in streptozotocin (STZ ) induced diabetic mice.
...Show More Authors

1-Objective:- Polyphenols are biochemical compounds with antioxidant activity against differences diseases related to Lipid peroxidation such as diabetes mellitus. Polyphenols distributed widely in medical plants, the aim of the study is to extract and analyze some polyphenolic compounds from grape seeds and examine their effects on (STZ) induced diabetic mice. 2-Methods:- In the present study , a group of polyphenols has been extracted from Iraq

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Revista Iberoamericana De PsicologÍa Del Ejercicio Y El Deporte
SPECIAL EXERCISES IN THE HIERARCHICAL OPPOSING TRAINING METHOD AND ITS EFFECT ON DEVELOPING PHYSICAL ABILITIES AND ACCURACY OF SOCCER SCORING FOR ADVANCED PLAYERS
...Show More Authors

Scopus (1)
Scopus
Publication Date
Mon Mar 02 2026
Journal Name
Journal Of Physical Education
The Effect of Inclusion Style Using Electronic Device On Learning Front and Side Movement in Squash For Beginners Aged 13 – 15 Years Old
...Show More Authors

View Publication
Publication Date
Sun Oct 01 2023
Journal Name
Heliyon
The preventive/therapeutic effect of CO2 laser and MI Paste Plus® on intact and demineralized enamel against Streptococcus mutans (In Vitro Study)
...Show More Authors

View Publication Preview PDF
Scopus (5)
Crossref (4)
Scopus Clarivate Crossref
Publication Date
Wed Aug 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
A Study on Transportation Models in Their Minimum and Maximum Values with Applications of Real Data
...Show More Authors

The purpose of this paper is to apply different transportation models in their minimum and maximum values by finding starting basic feasible solution and finding the optimal solution. The requirements of transportation models were presented with one of their applications in the case of minimizing the objective function, which was conducted by the researcher as real data, which took place one month in 2015, in one of the poultry farms for the production of eggs

... Show More
View Publication Preview PDF
Crossref