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).
S Khalifa E, N Adil A, K Nabeel O…, 2008
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Objectives: To identify quality of life (QOL) in Myocardial Infarction (MI) patients, and to find out the
relationship between QOL in MI patients and demographic characteristics.
Methodology: A descriptive colTelation study which utilized an assessment approach. The study was carried out
from March 2007 through November 2007 in order to assess the quality of life for patients with myocardial
infarction. A purposive "non-probability" sample of (75) patients with myocardial infarction who were attending
to Baquba General Hospita`l through their visits to that hospital. A questionnaire was adapted and developed
from the World Health Organization Quality of Life Scale (1998). The questionnaire was designed and
consisted
In this research we assumed that the number of emissions by time (𝑡) of radiation particles is distributed poisson distribution with parameter (𝑡), where < 0 is the intensity of radiation. We conclude that the time of the first emission is distributed exponentially with parameter 𝜃, while the time of the k-th emission (𝑘 = 2,3,4, … . . ) is gamma distributed with parameters (𝑘, 𝜃), we used a real data to show that the Bayes estimator 𝜃 ∗ for 𝜃 is more efficient than 𝜃̂, the maximum likelihood estimator for 𝜃 by using the derived variances of both estimators as a statistical indicator for efficiency
This paper deals with constructing mixed probability distribution from mixing exponential
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The study aimed to examine the sensitivity to stress and its relation to positive mood among educational supervisors. The researcher used the descriptive approach as more an appropriate method for the current study. The sample is composed of (200) educational supervisor. To collect study data, two scales have been used: one scale to measure the sensitivity to stress and the other to measure the positive mood. The results indicated that a high level of sensitivity to stress with low level of positive mood among educational supervisors, sensitivity to stress showed significant differences among the sample regarding to major. There is no correlation between sensitivity to stress and positive mood, and finally, there are no significant diffe
... Show MoreThe increase in the Iraqi population put pressure on urban cities as there were no new cities built since the 1980s due to the wars and the economic blockade imposed in 1991 and the deteriorating security situation after 2003, where the population in 2018 reached about forty million people. Iraq also suffered during the past decades from problems and challenges in many respects that affected the local environment, and the constructed buildings had a role in increasing these impacts, so the Ministry of Housing worked to issue the Iraqi Green Architecture Code in 2019 to reduce damage to the environment and use resources more efficiently. And because the constructed buildings were not constructed according to green standards, including Bas
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Aeroelastic flutter in aircraft mechanisms is unavoidable, essentially in the wing and control surface. In this work a three degree-of-freedom aeroelastic wing section with trailing edge flap is modeled numerically and theoretically. FLUENT code based on the steady finite volume is used for the prediction of the steady aerodynamic characteristics (lift, drag, pitching moment, velocity, and pressure distribution) as well as the Duhamel formulation is used to model the aerodynamic loads theoretically. The system response (pitch, flap pitch and plunge) was determined by integration the governing equations using MATLAB with a standard Runge–Kutta algorithm in conjunction with Henon’s method. The results are compared with
... Show MoreA Photo Dynamic Therapy (PDT) is a technique which is used with Laser to treat many of cancer
tissues. This paper deals with the relatively new therapeutic technique (PDT) with pulsed Nd:glass Laser
which was applied to human soft tissues (Ovary and Kidney tissues), and to the hard tissues (freshly
extracted human teeth), with power density of 280 watt/mm2 and exposure time 330 usec. Different
dyes (Blue, methylene, eosin, and orange) were applied to the area before irradiation to study the effect
of the pigments on the laser interaction with biological tissues. The zone of treatment (Z-necrosis) with
aid of MATLAB was determined. The relationship of zone of treatment with exposure time,
accumulated damage and fracti