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
Tue Jan 05 2010
Journal Name
Political Sciences Journal
دور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي
...Show More Authors

دور المراكز البحثية في الحياة السياسية وصنع القرار السياسي الخارجي الامريكي

View Publication Preview PDF
Crossref
Publication Date
Sun Sep 01 2019
Journal Name
Gazi University Journal Of Science
Reliable Iterative Methods for Solving Convective Straight and Radial Fins with Temperature-Dependent Thermal Conductivity Problems
...Show More Authors

In our article, three iterative methods are performed to solve the nonlinear differential equations that represent the straight and radial fins affected by thermal conductivity. The iterative methods are the Daftardar-Jafari method namely (DJM), Temimi-Ansari method namely (TAM) and Banach contraction method namely (BCM) to get the approximate solutions. For comparison purposes, the numerical solutions were further achieved by using the fourth Runge-Kutta (RK4) method, Euler method and previous analytical methods that available in the literature. Moreover, the convergence of the proposed methods was discussed and proved. In addition, the maximum error remainder values are also evaluated which indicates that the propo

... Show More
View Publication
Crossref (6)
Crossref
Publication Date
Wed Jun 13 2012
Journal Name
Journal Of Kerbala University
Thermo physical behaviour of binary and ternary systems for cyclohexanol with some Ketones at three temperature
...Show More Authors

Publication Date
Sun Jan 01 2017
Journal Name
Journal Of Engineering
Effect of Air Bubbles on Heat Transfer Coefficient in Turbulent Convection Flow
...Show More Authors

Experimental and numerical studies have been conducted for the effect of injected air bubbles on the heat transfer coefficient through the water flow in a vertical pipe under the influence of uniform heat flux. The investigated parameters were water flow rate of (10, 14 and 18) lit/min, air flow rate of (1.5, 3 and 4) lit/min for subjected heat fluxes of (27264, 36316 and 45398) W/m2. The energy, momentum and continuity equations were solved numerically to describe the motion of flow. Turbulence models k-ε was implemented. The mathematical model is using a CFD code Fluent (Ansys15). The water was used as continuous phase while the air was represented as dispersed. phase. The experimental work includes design, build and instrument a test

... Show More
View Publication Preview PDF
Publication Date
Sat Jan 05 2019
Journal Name
Iraqi Journal Of Physics
Fabrication and characterization of porous silicon for humidity sensor application
...Show More Authors

Porous Silicon (PS) layer has been prepared from p-type silicon by electrochemical etching method. The morphology properties of PS samples that prepared with different current density has been study using atom force measurement (AFM) and it show that the Layer of pore has sponge like stricture and the average pore diameter of PS layer increase with etching current density increase .The x-ray diffraction (XRD) pattern indicated the nanocrystaline of the sample. Reflectivity of the sample surface is decrease when etching current density increases because of porosity increase on surface of sample. The photolumenses (PL) intensity increase with increase etching current density. The PL is affected by relative humidity (RH) level so we can use

... Show More
View Publication Preview PDF
Crossref (3)
Crossref
Publication Date
Fri Oct 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Comparison between method penalized quasi- likelihood and Marginal quasi-likelihood in estimating parameters of the multilevel binary model
...Show More Authors

Multilevel models are among the most important models widely used in the application and analysis of data that are characterized by the fact that observations take a hierarchical form, In our research we examined the multilevel logistic regression model (intercept random and slope random model) , here the importance of the research highlights that the usual regression models calculate the total variance of the model and its inability to read variance and variations between levels ,however in the case of multi-level regression models, the calculation of  the total variance is inaccurate and therefore these models calculate the variations for each level of the model, Where the research aims to estimate the parameters of this m

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Dec 01 2018
Journal Name
Political Sciences Journal
The Patterns of the Strategic Environment and its Role in Determining Strategies for Dealing with Conflict and Peace Situations
...Show More Authors

Abstract

The decision maker needs to understand the strategic environment to be addressed through different means and methods. It is obvious that there is a difference between the three strategic environments (conflict environment, peace environment, post- peace environment) in terms of inputs and strategies to deal with each one of them. There is an urgent need to understand each pattern separately, analyze its inputs, and identify the factors and variables that affect the continuity of this situation (conflict, peace, post-peace). It is not appropriate to identify treatment without diagnosis of the condition, so it is very important to understand the type of strategic environment to be dealt with it.

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Oct 01 2016
Journal Name
Journal Of Economics And Administrative Sciences
Catalysts for money laundering and control by the banks / analytical study in the province of Arbil measures
...Show More Authors

Receive money laundering phenomenon of interest to researchers and scholars on different intellectual orientation of economic or political or other, as this process is gaining paramount importance in light of business and increase the number of banks in the province of Kurdistan of Iraq and Erbil in particular and in the presence of openness developments chaotic economic and there are no factors encourage money laundering operation because of the presence of the hidden economy and the weakness of the banking and legal measures to combat them, and on this basis there is a need to examine money laundering operation in the province of Arbil, to indicate the presence or absence of a money laundering operation in working in the provin

... Show More
View Publication Preview PDF
Crossref
Publication Date
Tue Dec 28 2021
Journal Name
Arab Science Heritage Journal
اللحن اللغــــوي بين الترجمة و أثر اللغـــات الأخرى
...Show More Authors

One of the infections that occurred on the Arabic tongue is melody, distortion and intruder, with it Arabic has moved away from classical Arabic, as it was taken from other western and eastern languages, the Arabic language is introduced, in addition to  foreign words that are one of the causes of the deviation of classical Arabic in the era of eloquence

View Publication Preview PDF
Crossref
Publication Date
Sat Jun 01 2013
Journal Name
Journal Of The College Of Languages (jcl)
The Intellectual as an Alien: A Study of Henry James's The Beast in the Jungle and James Joyce's "A Painful Case"
...Show More Authors

This research paper studies the alienation of the intellectuals in the modern novel through the study of two alienated characters, John Marcher in Henry James's The Beast in the Jungle, and Mr. Duffy in James's Joyce's "A Painful Case." As a result of the complexity of life in the industrial societies, the individuals, especially the intellectual ones, feel themselves unable to integrate into social life; they fear society and feel that it endangers their individuality and independence. Thus, these characters live on the fringe of the societ

... Show More
View Publication Preview PDF