This research studies the effect of grain size for the final stage in sintering Al2O3 .The experimental results for α- Al2O3 powder are modeled using ( L2-Regression ) technique in order to study the effect grain size distribution on densification rate using four kinds for the initial particle size which were ( 1.44 , 2.54 , 0.7-2.54 ,1.15-3.53 ) µm , and for sintering time (0-241) min. The mathematical simulation for grain size changing shows that the densification rates boots up as the grain size goes lower, this was due to the increase of contact area between the grains.
Abstract:
This study is considerated one of many Studies above the standing of
the Islamic Arab nation which was chosen by God from other nations all over
the world . Some of these nations used to come to the Arab nation to take
whatever useful for them from the beginning of history till now . The
researcher deals in this study with a French artist who is well-know as
August Renoir . He traveled to Algeria and lived there . He was
influenced by the Islamic culture.
The study include. from chapter . chapter one deals with the framework of
programming (out line ) . Chapter two deals with the theoretical framework .
It includes five sections. Deals with the Islamic drawings(Arabesque) . section
three deals w
Dam break is series phenomenon that can result in fatal consequences and loss of properties. Unfortunately, the observed consequences can only be available after the dam breaks. Therefore, it is important to anticipate what will happen prior to dam break to issue suitable warning and locate the possible risk areas. This study attempts to simulate the case of dam break in Blue Nile at Roseires dam and see its consequences downstream. Roseires dam lies at a distance of 630 km south of Khartoum, Sennar dam lies at about 260 km downstream of Roseires dam. In this study hydraulic model is developed based of Hydraulic Engineering Centre (HEC), River Analysis System (RAS), and HEC- RAS. The HEC-RAS based model is calibrated and validated usi
... Show MoreThe flavonoglycone hesperidin is recognized as a potent anti-inflammatory, anticancer, and antioxidant agent. However, its poor bioavailability is a crucial bottleneck regarding its therapeutic activity. Gold nanoparticles are widely used in drug delivery because of its unique properties that differ from bulk metal. Hesperidin loaded gold nanoparticles were successfully prepared to enhance its stability and bioactive potential, as well as to minimize the problems associated with its absorption. The free radical scavenging activities of hesperidin, gold nanoparticles, and hesperidin loaded gold nanoparticles were compared with that of Vitamin C and subsequently evaluated in vitro using 2,2-diphenyl-1-picrylhydrazyl assay. The antioxi
... Show MoreBackground: Little is known about asymmetry of children's dental arches, the purpose of this study was to verify the presence of asymmetry of dental arches among Iraqi children in the mixed dentition stage. Materials and methods: The sample included 52 pairs of dental casts, 27 pairs belong to males and 25 pairs for females. Three linear distances were utilized on each side on the dental arch: Incisal-canine distance, canine-molar distance and incisal-molar distance, which represent the dental arch segmental measurements using the digital sliding calipers, which is accurate up to 0.02 mm. Results: No significant sides' differences with high correlation coefficient were found between the right and left incisal-canine, canine-molar and in
... Show MoreThe increasing use of polymeric materials in the daily life, leads to challenges in the processing industry to deliver high performance materials with affordable terms. However, new processing techniques lead to high costs. In order to reduce processing costs it is necessary to understand the non-Newtonian behavior of the polymers in their molten state to be able to simulate the processes before the construction of the plants starts. Here the shear thinning behavior of the viscosity of polymeric melts is essential. Thus, this paper deals with the experimental investigation of the thermo-rheological behavior of the viscosity of one of the most used polymers (Polypropylene) over a wide range of temperatures and shear rates. Furthermo
... Show MoreE-learning applications according to the levels of enlightenment (STEM Literacy) for physics teachers in the secondary stage. The sample consists of (400) teachers, at a rate of (200) males (50%), and (200)females (50%), distributed over (6) directorates of education in Baghdad governorate on both sides of Rusafa and Karkh. To verify the research goals, the researcher built a scale of e-learning applications according to the levels of STEM Literacy, which consists of (50) items distributed over (5) levels. The face validity of the scale and its stability were verified by extracting the stability coefficient through the internal consistency method “Alf-Cronbach”. The following statistical means were used: Pearson correlation coefficient,
... Show MoreThe moral aspect is an important one in the structure of personality , and the lack of moral aspect is responsible for what we suffering today from problems . there is no exaggeration to say that many of our current problems are moral problems , and reflects the lack of moral growth.
The goal of research is to build scale in order to detect the level of moral reasoning among junior high school students in Baghdad , The researcher followed the procedures in the construction of scientific standards in order to measur
... Show MoreThe oil and gas production industry is considered the most important industries in the modern world because of its large relative significance among the group of energy recourses required for the world, where the natural resources represent the oil and natural gas fields, phosphate, gold, coal, forests and others. The most important advantage of the natural resources is its need for huge financial investments for a relatively long period of time from the beginning of the work until the start of extracting natural resources. Also, there are numerous cases where the natural source is not feasible exploited economically and is not discovered until after the passage of a long period of time from the start of work and paying relatively high a
... Show More