Preferred Language
Articles
/
alkej-502
Free Convection in an Inclined Concentric Annular Square Cavities Filled With Porous Medium and Heated By Non-Uniform Temperature
...Show More Authors

A numerical study of the two-dimensional steady free convection flow in an inclined annulus between two concentric square cavities filled with a porous medium is presented in this paper for the case when the side outer walls are kept with differentially heated temperature while the horizontal outer walls and the inner walls are insulated. The heated wall is assumed to have spatial sinusoidal temperature variation about a constant mean value. The Darcy model is used and the fluid is assumed to be a standard Boussinesq fluid. For the Cartesian coordinate system, the governing equations which were used in stream function form are discretized by using the finite difference method with successive under – relaxation method (SUR) and are solved by Gauss-Siedel iterative method. The upwind scheme was used for the transport terms in the energy conservation equation. The results are presented to demonstrate the streamlines, the isotherms, and the Nusselt number depending on the Rayleigh number ranging from (Ra =10 to 1000), dimension ratio from (Dr = 0.15 to 0.45), and the inclination angle from (= 0o to 45o). Also the effects of the amplitude (=0 to 1) and the wave number (f =0 to 5) of the heated side wall temperature variation on the free convection are investigated. The results show the effect of previous parameters (Ra, Dr,, , and f) on the flow fields and temperature profiles. It also show that the average Nusselt number is a strong function of the Rayleigh number, inclination angle, dimension ratio, and temperature variation. The peak value of the average Nusselt number based on the hot wall temperature is observed to occur at dimension ratio of (0.15), inclination angle of (40.1°), amplitude and wave  number (1 & 0.75) for Rayleigh number of (1000).

View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed May 17 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Effects of Temperature on Thermodynamic parameters and Carbon Nanotubes Growth Rate on Aluminum Electrode in Electrochemical deposition Process
...Show More Authors

 The optimum process conditions of the electrochemical deposition of carbon nanotubes (CNT) have been established by using developed, cheap and simple system. It has been found that temperature affects on the rate, purity and the yield of CNT obtained in this process. The electrochemical behavior of CNT deposition, kinetic and thermodynamic parameters were also discussed.

View Publication Preview PDF
Publication Date
Sat Dec 17 2022
Journal Name
Al-rafidain Journal Of Medical Sciences ( Issn: 2789-3219 )
Organic Synthesis under Solvent-free Condition (Green Chemistry): A Mini Literature Review
...Show More Authors

Solvents are important components in the pharmaceutical and chemical industries, and they are increasingly being used in catalytic reactions. Solvents have a significant influence on the kinetics and thermodynamics of reactions, and they can significantly change product selectivity. Solvents can influence product selectivity, conversion rates, and reaction rates. However, solvents have received a lot of attention in the field of green chemistry. This is due to the large amount of solvent that is frequently used in a process or formulation, particularly during the purification steps. However, neither the solvent nor the active ingredient in a formulation is directly responsible for the reaction product's composition. Because these ch

... Show More
View Publication
Scopus (1)
Crossref (1)
Scopus Crossref
Publication Date
Mon May 20 2019
Journal Name
The Journal Of Engineering
Experimental comparison of two linear machines developed for the free piston engine
...Show More Authors

: In this study, a linear synchronous machine is compared with a linear transverse flux machine. Both machines have been designed and built with the intention of being used as the power take off in a free piston engine. As both topologies are cylindrical, it is not possible to construct either using just flat laminations and so alternative methods are described and demonstrated. Despite the difference in topology and specification, the machines are compared on a common base in terms of rated force and suitability for use as a generator. Experience gained during the manufacture of two prototypes is described.

View Publication Preview PDF
Crossref (9)
Clarivate Crossref
Publication Date
Sat Jul 22 2023
Journal Name
Journal Of Engineering
Effect of Steel Fibers on the Properties of Refractory Free Cement Concrete
...Show More Authors

Free cement refractory concrete is a type of refractory concrete with replacing alumina cement by bonding materials such as white kaolin, red kaolin and fumed silica. The free cement refractory concrete used in many applications like Petrochemicals, iron furnaces and cement production industries. The research clarifies the effect of steel fibers with two types crimped steel fibers and hooked steel
fibers with percentages 0.5%, 1% and 1.5% by volume from weight of bauxite aggregates. The additions of steel fibers with two types gave good properties in high temperatures where the specimens keep the dimension without failure and the properties made the best. the percentage of increasing for thermal conductivity was 44% for 1.5% crimped

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Mon Jan 28 2013
Journal Name
Spie Proceedings
Enhancement of security for free space optics based on reconfigurable chaotic technique
...Show More Authors

Free Space Optical (FSO) technology offers highly directional, high bandwidth communication channels. This technology can provide fiber-like data rate over short distances. In order to improve security associated with data transmission in FSO networks, a secure communication method based on chaotic technique is presented. In this paper, we have turned our focus on a specific class of piece wise linear one-dimensional chaotic maps. Simulation results indicate that this approach has the advantage of possessing excellent correlation property. In this paper we examine the security vulnerabilities of single FSO links and propose a solution to this problem by implementing the chaotic signal generator “reconfigurable tent map”. As synchronizat

... Show More
View Publication
Scopus (3)
Crossref (2)
Scopus Clarivate Crossref
Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Educational And Psychological Researches
Under the title "ideas to demonstrate and prove some new insight into the measurement of psychological and educational assessment"Paragraphs of the psychometric analysis between the logical and virtual (for arbitrators experts and specialists) and the sta
...Show More Authors

   Thsst researcher problem of delays faced by researchers are all waiting to evaluate their standards by the experts who must take their views to extract the truth Virtual important step first step in building standards whatsoever, then the difference of opinion among experts about the paragraphs Whatever the scope of their functions, leading to confusion in maintaining these paragraphs or delete? Or ignore the views and opinion of the researcher to maintain the same? Or as agreed upon with the supervisor if he was a student? Especially if the concepts of a modern new building.
   Therefore, the researcher sought to try to find a solution to her problem to conduct an experiment to test building steps

... Show More
View Publication Preview PDF
Publication Date
Thu Oct 01 2015
Journal Name
Al-academy
Problems between acter and director in film and t.v: صالح الصحن
...Show More Authors

Constitute the relationship between the director and actor mainstay chock done to show art in film and television , both of which occupy what a big role in the mission accomplishment . The leadership of the director of the artwork in various joints require two features two important ( creativity and administration ) , The capabilities director of creative serves as an added intellectual and aesthetic saturated sensation that leaves its impact on all the technical elements involved in done. Either trait administration and leadership it is what requires multiple skills in dealing on according to technical standards and moral and humanitarian allow the transfer of ideas , concepts and visions to those elements to embody and implement the ki

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Jan 31 2019
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Analysis the Expected Profit By the Relation Between the Sustainable growth and Actual growth: Apply Study for Iraq Stock Exchange
...Show More Authors

The research aims to analysis the future profits of companies listed on the Iraq Stock Exchange through analyzing the relationship between Actual Growth and Sustainable Growth, The study was applied to the sample of companies included in the Iraq Stock Exchange for the period (2010- 2014), The Internal Growth Rate has been used as a measure for the Actual Return Rate but the Sustainable Growth Rate has been measured under the Rose model, The research showed group of conclusions, the most important are:1. From the analysis of sustainable growth for the banks sample and the variables involved in its measure shows that investment in the investors amounts have achieved a significant return, which demonstrates the company's efficiency at gene

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 01 2018
Journal Name
Materials Letters
Temperature stable electric field-induced strain in Er-doped BNT-BT-BKT ceramics
...Show More Authors

View Publication
Scopus (15)
Crossref (12)
Scopus Clarivate Crossref
Publication Date
Tue Mar 01 2016
Journal Name
المصرية للدراسات القانونية والاقتصادية
مدى تحقق المنافسة غير المشروعة في حق المؤلف
...Show More Authors

Preview PDF