A numerical investigation has been performed to study the effect of eccentricity on unsteady state, laminar aiding mixed convection in a horizontal concentric and eccentric cylindrical annulus. The outer cylinder was kept at a constant temperature
while the inner cylinder was heated with constant heat flux. The study involved numerical solution of transient momentum (Navier-Stokes) and energy equation using finite difference method (FDM), where the body fitted coordinate system (BFC) was
used to generate the grid mesh for computational plane. The governing equations were transformed to the vorticity-stream function formula as for momentum equations and to the temperature and stream function for energy equation.
A computer program (Fortran 90) was built to calculate the bulk Nusselt number (Nub) after reaching steady state condition for fluid Prandtl number fixed at 0.7 (air) with radius ratio ( =2.6), Rayleigh number (Ra=200), Reynolds number (Re=50) for both concentric and eccentric cylindrical annulus with different eccentricity ratios (ε=0, 0.25, 0.50, 0.75) and angular positions (φo=0o
, 45o , 90o , 135o , 180o ).
The results show a reasonable representation to the relation between Nusselt number and (ε, φo). Generally, Nub decreased with the increase in (ε and φo). Also, results show that the best thermal performance for the inner cylinder was at the angular
position (φo=0o ) for eccentricity ratio (ε=0.25), while the maximum reduction in the rate of heat transfer for the inner cylinder was at the angular position (φo=180o) for eccentricity ratio (ε=0.75).
Comparison of the result with the previous work shows a good agreement.
As a result of the developments that occurred in technological and digital technologies, which had a fundamental role in changing the paths of science, including the sciences of communication and the art of design, especially since these developments were the result of the information revolution, which called for the need to find alternatives that contribute to organizing presentations of information and texts in accordance with the manufacture of constructive content to deliver A communication message for the recipient to achieve culture and communication together, as it has become necessary to employ technical and digital developments in organizing that information according to the rules and laws of design and producing newspapers asso
... Show MoreThis research deals with the motives of the use of Facebook by elderly people and the achieved needs, which leads the researcher to ask an important question: why an old persons use Facebook and are the achieved needs through which they got? The research aims to find out the habits and patterns of using Facebook by old men and stands on the main motives of the elderly in their use of Facebook. It also identifies the most prominent needs that have been made for the elderly as a result of their use of Facebook.
The research is a descriptive one in which the researcher uses survey method to achieve the desired goals. The researcher has chosen a group of old men from Diyala province. The total sample number is about
... Show MoreThis work was conducted to study the extraction of pelletierine sulphate from Punica granatum L. roots by liquid membrane techniques. Pelletierine sulphate is used widely in medicine. The general behavior of extraction process indicates that pelletierine conversion increased with increasing the number of stages and the discs rotation speed but high rotation speed was not favored because of the increased risk of droplet formation during the operation. The pH of feed and acceptor solution was also important. The results exhibit that the highest pelletierine conversion was obtained when using two stages, (10 rpm) discs speed of stainless steel discs, (pH=9.5) of feed solution and (pH=2) of acceptor solution in n-decane. Assuming the existen
... Show MoreObjectives: Umbilical cord blood can be taken at birth and largely gives indication of fetal and maternal conditions. The aim of the study was to investigate the relation between sex hormones in cord blood and birth weight of newborns and pregnancy complications. Methods: Fifty cord blood samples were collected from newborns at labor room of Baghdad Teaching Hospital between May and October 2018. Blood was withdrawn from their mothers for lead analysis. Five milliliters (ml) of cord blood was taken, 3 ml was used for testosterone and estradiol analysis (using enzyme-linked immunosorbent assay) and 2 ml for lead measurement by lead care analyzer. Newborns weight and head circumference were measured. Delivered women were divided into four gro
... Show MoreThis research delves into the role of satirical television programs in shaping the image of Iraqi politicians. The research problem is summarized in the main question: How does satire featured in television programs influence the portrayal of Iraqi politicians? This research adopts a descriptive approach and employs a survey methodology. The primary data collection tool is a questionnaire, complemented by observation and measurement techniques. The study draws upon the framework of cultural cultivation theory as a guiding theoretical foundation. A total of 430 questionnaires were disseminated among respondents who regularly watch satirical programs, selected through a multi-stage random sampling procedure.
Th
Abstract
This paper is an experimental work to determinate the effect of welding velocity and formed arc energy for CO2-MAG fusion weld pool. The input parameters (arc voltage, wire feed speed and gas flow rate) were investigated to find their effects on the weld joint efficiency. Design of experiment with response surface methodology technique was used to build empirical mathematical models for welding velocity and arc energy in term of the input welding parameters. The predicted quadratic models were statistically checked for adequacy purpose by ANOVA analysis. Additionally, numerical optimization was conducted to obtain the optimum values for welding velocity and arc energy. A good agree
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1- The degree of self-control of the educational counselors.
2- The level of work pressures that educational counselors are exposed to from their point of view.
3- The significance of the differences in the degree of self-control and work pressures according to the gender variable (male / female).
4- The relationship between self-control and work stress for the sample as a whole.
The current research was limited to educational counselors of both sexes in Anbar Governorate, Ramadi District, affiliated to the Anbar Education Directorate. The researcher adopted the steps of the relational descriptive approach to achieve the research objectives. The current research community consists of (100) m
... Show MoreHeuristic Program proposal for the treatment of talented emotional and Cognitive problems .
1-The Curtent research aims : to identify the needs of gifted students and their problems and Ways to diagnose .
2-reprepare aproposal heuristic program for the treatment of emotional and Cognitive talented problems .
Research . Methodology : analytical and descriptive .
Define the terms
Virt uoso is the per for mance of the privileged Mstmrave performances appear in any area of his Values .
Chapter ll : Includes recipes gifted child and Methods diagnosis gifted by filtrontion and standavds of personal and mental and behavioral Doramwaliman and parental Features and Leader in the detection of the gif
... Show MoreObjectives: To identify the impact of Pap smear upon physical and psychological and social aspects of women's
health.
Methodology: A purposive sample of (71) women. The data were collected through the utilization of the
developed questionnaire which consists of four major parts: 1. demographic 2.Physical domain 3. Psychological
domain 4. social domain and by means of interview technique with the women who were individually interviewed
in the Baghdad Teaching Hospital/ the Consultant Clinic, Teaching Laboratories/ Medical City, AL-Elwyiah
Maternity Hospital . The data collection process has been performed from April 17th, 2011 until the August 10th,
2011. Descriptive and inferential statistical analysis procedures wer