Transient three-dimensional natural convection heat transfer due to the influences of heating from one side of an enclosure filled with a saturated porous media, whereas the opposite side is maintained at a constant cold temperature, and the other four sides are adiabatic, were investigated in the present work experimentally. Silica sand was used as a porous media saturated with distilled water filled in a cubic enclosure heated from the side,using six electrical controlled heaters, at constant temperatures of (60, 70, 80, 90, and 100oC). The inverse side cooled at a constant temperature of (24oC) using an aluminum heat exchanger, consisted of 15 channels feeded with constant temperature water. Eighty thermocouples were used to control the heated and cooled sides, and to measure the temperature in the entire enclosure. Experimental results showed that the heat transfer regime was mainly conduction for all Rayleigh numbers with small influence of convection for Ra=42 and greater for Ra=55. This effect increased with the angle of inclination of the enclosure. Numerical and experimental results showed a good agreement. There was a rapid increase in the temperature at the entire media at the early time, reduced gradually until the steady state condition reached. This temperature and heat transfer to and from the porous media, were increased as the Rayleigh number and/or inclination angle increased. The Nusselt number increased directly with the angle of inclination up to o θ = 45 and then decreased. Correlation equations are obtained from the experimental investigation, showed the change of the average and local Nusselt number with time, distance, Rayleigh number, and the inclination angle.
The study attempts to measure the level of shyness; the level of psychological isolation; to identify the relationship between shyness and psychological isolation; and to identify the differences between shyness and psychological isolation among first-intermediate students. To this end, a random sample comprised (187) male and female students was chosen for the academic year (2016-2017) from Baghdad \ Al-Rasafa. To measure the shyness and psychological isolation, the researcher designed two scales: one to measure the shyness composed of (37) items divided into four domains; and the other to measure the psychological isolation made of (56) items divided into three domains. The study concluded that the sample has a medium level of shyness;
... Show MoreThe study aims to analyze computer textbooks content for preparatory stage according to the logical thinking. The researcher followed the descriptive analytical research approach (content analysis), and adopted an explicit idea during the analysis process. One of the content analysis tools which was designed based on mental processes employed during logical thinking has utilized to figure out the study results. The findings revealed that logical thinking skills formed (52%) in fourth preparatory textbook and (47%) in fifth preparatory textbook.
Sphingolipids (SLs) are major structural constituents of eukaryotes, including the kinetoplastid parasite Leishmania. SLs are important for cellular trafficking and signaling and participate in different cell functions, such as, differentiation and cell death (apoptosis). In this study we have investigated the viability of Leishmania major wild type (W.T) and L. major knockout LmLCB2, one of two subunits of serine palmitoyl transferase (SPT) after treatment with myriocin (potent inhibitor of SPT) in order to detect the survival and proliferation of the parasites in vitro. This is to focus on the de novo sphingolipids biosynthesis pathway in both Leishmania wild type which can synthesize SPT and knockout Leishmania which genetically ablated
... Show MoreThis study aims to simulate and assess the hydraulic characteristics and residual chlorine in the water supply network of a selected area in Al-Najaf City using WaterGEMS software. Field and laboratory work were conducted to measure the pressure heads and velocities, and water was sampled from different sites in the network and then tested to estimate chlorine residual. Records and field measurements were utilized to validate WaterGEMS software. Good agreement was obtained between the observed and predicted values of pressure with RMSE range between 0.09–0.17 and 0.08–0.09 for chlorine residual. The results of the analysis of water distribution systems (WDS) during maximum demand
In this paper, an estimate has been made for parameters and the reliability function for Transmuted power function (TPF) distribution through using some estimation methods as proposed new technique for white, percentile, least square, weighted least square and modification moment methods. A simulation was used to generate random data that follow the (TPF) distribution on three experiments (E1 , E2 , E3) of the real values of the parameters, and with sample size (n=10,25,50 and 100) and iteration samples (N=1000), and taking reliability times (0< t < 0) . Comparisons have been made between the obtained results from the estimators using mean square error (MSE). The results showed the
... Show MoreThe research aims to examine the effect of KUD strategy on acquiring the grammatical concepts among intermediate school students. To achieve the research objective, the researcher adopted the null hypothesis in which there is no statistically significant difference at the level (0.05) between the average scores of students of the experimental group who study grammar base on the KUD strategy and the average scores of the control group who study the grammar through the traditional way of acquiring grammatical concepts. In a random manner, the researcher selected the research sample from one of Baghdad’s education schools in al Rusafa / 2, as the total number of students of the two groups reached (67) students. They were divided into (33)
... Show MoreThe ancient Iraqis in the Mesopotamian civilization practiced various sports activities and physical exercises to develop their physical fitness until these practices became a part of their lives and accompanied their religious, social, and military celebrations. Music had a presence in many sports scenes, and the presence of musicians and musical instruments with the armies indicated its great role. In the military scene, the research aims to shed light on the archaeological evidence and evidence of the integration of music with the sports and military scene in Mesopotamian civilization and to explore the impact of music in the sports and military scene of Mesopotamian civilization. The historical approach was adopted in collecting and des
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The human intellect and his ability to complex thinking is a characteristic that Allah has given him above all his creatures. Islam came to encourage the utilization of the mind by thought, contemplation and consideration of the kingdom of Allah, His signs and religion, and He gave us a set of legislation that preserves the mind and protects it from falling into error or deviation.
This research deals with one of the most important components of civilizations in general and Islamic civilization in particular, which is thinking and what is related to it. It is an essential and influential component in man's dealing with life around him and the for
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