A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the coolant is indicated. The radiation has a considerable effect on the computed wall temperature values.
The determination of river pollution impact on the performance of water treatment plants is achieved by two main objectives. The first is to study raw and treated water qualities and comparing them with standards and the second is to evaluate the treatment plants efficiency. The analyzed data were those water quality parameters in relation to physical, chemical and bacteriological characteristics for river water and produced water by seven water treatment plants located on Tigris River passing through Baghdad City.
The results of this study indicated that all raw water characteristic are within the surface water standards established by Iraqi and USA criteria except Bacterial Counts.
Tigris River water is of good quality to be trea
In this study, new heterocyclic compounds were synthesized through the cyclization reactions of o-phenylenediamine (1) with various organic reagents. Benzodiazepine derivatives (2-4) were obtained by reaction of (1) with ethylacetoacetate, malonic acid and acetyl acetone.Treatment of compound (1) with chloroacetamide, chloroacetic acid, p-bromophenacyl bromide and oxalic acid dihydrate afforded quinoxaline derivatives (5-8), respectively. Reaction of compound (1) with benzoic acid, piperonal, cyclohexanone and carbon disulfide resulted in the formation of compounds (9-12), respectively. Finally, reaction of compound (12) with chloroacetic acid in the presence of potassium hydroxide produced compound (13).
Zirconia ceramic restoration (ZCR) has a higher fracture incidence rate than metal ceramic restoration. Different surface treatments were used to improve fracture performance of ZCR such as grit blasting (GB) by aluminium oxide powder. This type of surface treatment generate residual stresses on veneering ceramic causing crack initiation and ending with a fracture. In order to overcome the stress generated by GB, zirconia surface coating is used as a surface treatment to improve fracture resistance and to accommodate stresses along the ZCR layers. Fifty zirconia ceramic crowns were fabricated and divided according to the type of surface treatment into three groups; the first group is (ZG), involving 20 cores were coated with a mixture of pa
... Show MoreObjective: Conventional approaches for disinfection, including spraying and immersion, resulted in only surface disinfection of impressions. As a result, self-disinfecting impression materials incorporated with antimicrobial compounds require more extensive studies. The incorporation of a disinfectant into irreversible hydrocolloid impression materials could eliminate the need for the disinfection step by conventional approaches, including spraying and immersion which only result in surface disinfection of impressions. The study was aimed to investigate the effect of incorporation of hypochlorous acid in irreversible hydrocolloid materials on antimicrobial efficiency, detail reproduction, and dimensional stability. Materials and
... Show MoreThe purpose of this resesrh know (the effectiveness of cooperative lerarning implementation of floral material for calligraphy and ornamentation) To achieve the aim of the research scholar put the two zeros hypotheses: in light of the findings of the present research the researcher concluded a number of conclusions, including: -
1 - Sum strategy helps the learner to be positive in all the information and regulations, monitoring and evaluation during the learning process.
2 - This strategy helps the learner to use information and knowledge and their use in various educational positions, and to achieve better education to increase its ability to develop thinking skills and positive trends towards the article.
In light of this, the
Abstract The results of the effect of the type of feed showed a significant increase (P≤0.01) for palm fronds DM during the incubation period of 7, 14, 21 days, a high Mnp superiority in its incubation 14 days, and a significant superiority of Laccase in its incubation 21 days, while the effect of the enzyme concentration on DM was higher Significant at a concentration of 10% of the enzyme, and the interaction between the type of feed and the enzyme together showed a highly significant increase in the treated palm fronds Laccase and Lip in the incubation period of 7 days, and the treated palm fronds Mnp during incubation 14 days. %, 15% for the interaction between the type of coarse feed and the concentration of the enzyme
... Show MoreThe article deals with the role of metaphors in forming the plot of L. Ulitskaya’s family chronicle “Medea and Her Children”. The author of the article describes the results of the next stage of research related to the works of Lyudmila Evgenievna Ulitskaya, a representative of modern Russian prose. The analysis of tropes and figures in the works written at the turn of the XXth – XXIth centuries is of importance for the study of the modern state of Russian language as an independent system. “Medea and Her Children” is one of the works by L. Ulitskaya (written in 1996), which, like her other works, is characterized by a unique style of narration, rich in vocabulary, lexical, semantic and stylistic diversity of the author’s word
... Show MoreThe main objective of this research is to identify the role of job satisfaction in influencing strategic agility through knowledge sharing. The researcher used the descriptive as well as the analytical approach in the completion of this research by collecting data by means of the questionnaire as the main tool on a sample of the General Company for Food Industries' employees, whose number reached (76) individuals. Moreover, some statistical methods were employed to process the data; including the arithmetic mean, Standard deviation, simple linear correlation coefficient (Pearson), simple linear regression, and the median variable test. It was represented that there is a significant and essential impact of job satisfaction in influen
... Show MoreThis study aimed to statement jet stream and its impact in the anti-cyclone affecting the climate of Iraq. Through the use of simple correlation coefficient ( Pearson ) that there is a very strong relationship between high- Siberian and both of the jet stream especially during the winter or over the stations of North . Therefore we, observe the relationship be significant in most of the winter months , spring and autumn . Statistically significant , but are different between station and another station , while the study come to another Anti-ciyclon have a real ,significant and statistically relationship corrclation . But this relationship is less than which found in are much less it with the Siberian high , it depends on the type of stat
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