As the temperature of combustion gases is higher than the melting temperature of the turbine materials, cooling of turbine parts in a gas turbine engine is necessary for safe operation. Cooling methods investigated in this computational study included cooling flow losses. Film-cooling is one typically used cooling method whereby coolant is supplied through holes passage, in present study the holes placed along the camber line of the blade. The subject of this paper is to evaluate the heat transfer that occur on the holes of blade through different
blowing coolant rates. The cases of this study were performed in a low speed wind tunnel with two tip gap at small and large (0.03 and 0.09cm) and multiple coolant flow rates through the film-cooling holes. The
blowing ratios was studied whereby coolant was injected from holes placed along the tip of a large scale blade model with Reynolds number (2.1 x 105 ) of the engine was matched. Results showed that baseline
Nusselt numbers on the holes were reduced along the holes passage, and heat transfer coefficient is high values at iterance region. Overall, the cooling by holes appears to be a feasible method for prolonging blade life.
The determination hardness in water raised to rivers caused several problem in the validity of the water used depends on where determination ions concentration calcium and magnesium in salts carbonate and sulfate , this possibility of separation between of these ions and the resulting impact on concentration and determination the degree of hardness water and appreciation between the insolvent water quality . It study the effect of the impact of concentration magnesium ion in determination the quality of the water has turned out to be Mg concentration more than 60% of the total content of hardness is borderline in hardness effect the determination. Adopted in this research determination the ions in two method titration by EDTA solution and
... Show MoreBackground: Considering the antioxidant, anti-inflammatory, and antimicrobial properties of green tea, this study aimed to evaluate the histopathological effect of the sulcular irrigation of green tea extract in the treatment of experimental gingivitis in rabbit.
Materials and methods: For this experimental study, 45 male rabbits, separated in two groups, control non- irrigated group (5rabbits) and study group (40 rabbits), gingivitis induced by ligatures was packed subgingivally in the lower right central incisors of the experimental group for seven days. Then, the animals were randomly designated to two irrigated groups (20 rabbits
... Show MoreThe vast advantages of 3D modelling industry have urged competitors to improve capturing techniques and processing pipelines towards minimizing labour requirements, saving time and reducing project risk. When it comes to digital 3D documentary and conserving projects, laser scanning and photogrammetry are compared to choose between the two. Since both techniques have pros and cons, this paper approaches the potential issues of individual techniques in terms of time, budget, accuracy, density, methodology and ease to use. Terrestrial laser scanner and close-range photogrammetry are tested to document a unique invaluable artefact (Lady of Hatra) located in Iraq for future data fusion sc
The comparative study tries to find the common points in two different authors’ works and in this kind of studying so many other common but the hidden points may be revealed. Postwar literature is somehow one of the best literary genres for finding the common factors and features that the poets have tried to present in their works elements such as desire to be winner, cruelty, inhumanity, and absurdity of the war. The Iranian poet late Qaisar Aminpour(1961-2007) and Yusef Komunyakaa ( 1947) from Bogalusa, Louisiana, are among the great American and Iranian poets whose works so many times have been interpreted and analyzed. The finding the outstanding and the most important points and themes in the postwar poems of these
... Show MoreThis research paper aims at studying the effect of adopting the corporate social responsibility on marketing performance indicators, where the study adopted the descriptive method for theoretical concepts, in addition to the statistical approach by using the SPSS v25 program to analyze the questionnaire and test the hypotheses of the study. The results showed that there is a positive correlation between social responsibility and marketing performance indicators, and the study found that it is better for NAFTAL Company to mix the environmental and social responsibilities in order to improve its marketing performance. Also, the study recommended that Naftal should adopt the four responsibilities equally, correctly and make its work
... Show MoreOdontogenic cysts and tumors often form hard and soft structures that resemble odontogenesis. It is well known that amyloid is produced in Pindborg tumors; however, it is still debatable whether it is also formed in other odontogenic tumors and cysts. This study aimed to detect the presence of amyloid in different odontogenic cysts and tumors in correlation to matrix proteins secreted during enamel formation; namely amelogenin and odontogenic ameloblast‐associated protein.
This study included formalin fixed paraffin embedded tissue blocks of 106 different types of odontogenic