Thermal conductivity for epoxy composites filled with Al2O3 and Fe2O3 are
calculated, it found that increasing the weight ratio of Al2O3 and Fe2O3 lead to
increase in the values of thermal conductivity, but the epoxy composite filled with
Fe2O3, have values of thermal conductivity less than for epoxy composite filled with
Al2O3, for the same weight ratio. Also thermal conductivity calculated for epoxy
composites by contact to every two specimens (like sandwich) content same weight
ratio of alumina-oxide and ferrite-oxide, its found that the value of thermal
conductivity lays between the values of epoxy filled Al2O3 and of epoxy filled Fe2O3
Frictional heat is generated when the clutch starts to engag. As a result of this operation the surface temperature is increased rapidly due to the difference in speed between the driving and driven parts. The influence of the thickness of frictional facing on the distribution of the contact pressure of the multi-disc clutches has been investigated using a numerical approach (the finite element method). The analysis of contact problem has been carried out for a multiple disc dry clutch (piston, clutch discs, separators and pressure plate). The results present the distribution of the contact pressure on all tShe surfaces of friction discs that existed in the friction clutch system. Axisymmetric finite element models have been developed to ac
... Show MoreAccurate description of thermodynamic, structural, and electronic properties for bulk and surfaces of ceria (CeO2) necessitates the inclusion of the Hubbard parameter (U) in the density functional theory (DFT) calculations to precisely account for the strongly correlated 4f electrons. Such treatment is a daunting task when attempting to draw a potential energy surface for CeO2-catalyzed reaction. This is due to the inconsistent change in thermo-kinetics parameters of the reaction in reference to the variation in the U values. As an illustrative example, we investigate herein the discrepancy in activation and reaction energies for steps underlying the partial and full hydrogenation of acetylene over the CeO2(111) surface. Overall, we find th
... Show MoreThe results of this study showed that the tongue of the adult Iraqi domestic cat is divided into three regions of apex, body and root. The dorsal surface of all regions possesses five types of lingual papillae, two mechanical which are filiform and cylindrical papillae, while the other three types are taste papillae which are foliate, fungiform and circumvallate papillae, while these papillae are absent on its ventral surface. The histological examination of all tongue areas revealed that it consisted of three tunica, the tunica mucosa and the tunica submucosa (the lamina propria) and the tunica muscularis. The tunica mucosa consisted of the epithelial lining, which is a stratified squamous epithelial tissue covering the lingual papillae, a
... Show MoreThe influence of fear on the dynamics of harvested prey-predator model with intra-specific competition is suggested and studied, where the fear effect from the predation causes decreases of growth rate of prey. We suppose that the predator attacks the prey under the Holling type IV functional response. he existence of the solution is investigated and the bounded-ness of the solution is studied too. In addition, the dynamical behavior of the system is established locally and globally. Furthermore, the persistence conditions are investigated. Finally, numerical analysis of the system is carried out.
This study examines the species composition, biodiversity, zoogeography, and ecology of freshwater gastropods of 12 springs in Andijan region of Uzbekistan. The study used generally accepted malacological, faunistic, ecological, analytical, and statistical methods. As a result of research in the springs, 14 species of freshwater gastropods belonging to 2 subclasses, 5 families, and 10 genera were recorded. 7 of them are endemic to Central Asia. When indicators of biodiversity of mollusks were analyzed according to the Shannon index, it was found that the highest value was recorded in the springs besides the hills. According to the biotope of distribution and bioecological features, they were divided into cryophilic, phytophilic, pelophil
... Show MoreThe techniques of contemporary Iraqi painting and their reflection on the productions of students of art education is an important subject in the field of painting at the theoretical and practical levels in academic study, whether theoretical or practical. Al-Iraqi is one of the arts with historical roots and a distinguished position among other artistic genres. Painting has received a sufficient level of development through the use of various contemporary techniques to advance it for the better.
The methodological framework included the problem of research and the need for it, and then the importance of research came in shedding light on the techniques of contemporary Iraqi painting, and the impact of these techniques on the producti
The effect of adding different volume of coumarin dye (5, 15, 25 and 35) ml on optical properties of Poly (Methyl Meth Acrylate) was studied. Films of pure PMMA and PMMA with different volume of coumarin dye (5, 15, 25 and 35) ml were prepared using the casting technique. Transmission and absorption of the films were measured by using UV-VIS spectrometer technique type (100 Conc), in order to assess the type of transmission which was found an indirect transition. An optical energy gap of pure PMMA is (4.95e v) and after adding coumarin with volume (25, 35) ml, the energy gap for PMMA decrease by (0.05) compere to pure PMMA films and addition energy gap appear equal to (4.1 e v). It was found that the absorption coefficient, extinction coeff
... Show MoreThe global rise in temperature and the desert climatic conditions prevalent in Middle Eastern countries have exacerbated rutting distress in heavily trafficked highways. Conventional asphalt binders with a high-temperature performance grade (PG 70) have proven inadequate under such extreme conditions, necessitating the development of modified binders with enhanced high-temperature performance. While polymer modification using styrene-butadiene-styrene (SBS), an elastomeric polymer, and ethylene-vinyl acetate (EVA), a plastomeric polymer, has been widely studied, limited research provides a direct comparison of their effectiveness at both the binder and mixture levels under extremely high-temperature conditions. This study addresses this gap
... Show MoreThe result showed that hot water and ethanol extracts of Nigella sativa contain alkaloids ,saponins, flavonoids,tannins,glycosides,terpins and steroids. Albino mice were administered orally with 0.1 of the extract at dose of 100 mg/kg, body weight the results showed high level of white blood cell ,total and differential count of WBC,phagocytosis index, mitotic index, Arthus and delayed type hypersensitivity. The result, also showed high level of hemoglobin (Hb) and the packed cell volume (PCV) the alcoholic extract has been found more efficient than hot water extract on mice.
Klebsiella pneumoniae are Gram-negative which cause many diseases such as urinary tract infections, respiratory tract infections and septicemia. Inulinase is an enzyme used in food manufacture and pharmaceuticals. Inulinase is used in decreasing lipid ratio and, cholesterol in blood and considered as a prebiotic factor inside intestine. Many microorganisms can produce inulinase, such as yeast, fungi and bacteria; among such bacteria: Bacillus spp., Arthrobacter spp., and Pseudomonas spp. but there are no studies about inulinase production by K. pneumoniae have been reported. So the current study aims at investing the ability of producing and purification inulinase by K. pneumoniae. Method: K. pneumoniae were isolated from many hospitals and
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