Three different rotational speeds (800, 1000 and 1250 rpm) and traverse speeds of (0.42 mm/sec) at a constant taped pin have been employed to produce the stir zones generated from friction stir processing (FSP) of near eutectic Al- 14 wt.% Si alloy. The processed samples were thoroughly analyzed macroscopically and microscopically. The as-cast microstructure of eutectic (α Al+ Si) and primary Si were fragmented to produce spheroidization of small size of Si and deformed matrix. The stir zones showed an increase in hardness from around 45-50 Hv for as-cast to 40-65 depending on the variables applied. All the processed samples were characterized by advanced and retreated regions with large single piping defects formed mainly at the retreated region. High temperature spheroidization at 500 oC with two soaking times of 10 and 20 hrs was applied for the processed sample of 1000 rpm to investigate the effect of heat treatment on the silicon fragmentation and hardness. Growth and fragmentation of Si have taken place at soaking time of 10 hrs. At soaking time of 20 hrs noticeable microvoids and macrovoids were formed at the stir zones. Microhardness of both the advancing and the retreating regions decreased with increasing soaking time.
The research dealt with its forefront a definition of the aspects of the study and its variables, the explosive capacity and its relationship to the scoring of football for the halls and highlights the importance of these variables, and the problem of the research consisted that some players fail to score Amie because of the weak power of shots or the slow scoring, so the researchers saw studying this problem and knowing the extent of the influence of the explosive strength During the performance of the skill of scoring with five football, the study aimed to identify the relationship between the explosive strength and the skill of scoring with five football. Researchers assume that there is a statistically significant relationship between t
... Show MoreThe study aims to identify the reality of the use of educational technology in the teaching of mathematics from the point of view of mathematics teachers in Amman, where the researcher used the descriptive survey method. The sample included (67) female teachers working in public schools in Amman. In order to achieve the objectives of the study, the researcher used the questionnaire as a tool to collect data. The study concluded that many educational techniques are not available from the point of view of the study sample. Mathematics teachers also found that there are many obstacles that prevent the use of educational techniques in schools, most notably the lack of courses offered to teachers on the use of teaching techniques in teaching
... Show MoreThe research problem consisted in answering the question that revolves around whether there is a relationship to the settlement of salaries with the growth of bank deposits? The research also aimed to provide some initial solutions to improve the role of salary localization, in terms of reviewing the concept of electronic payment systems, its tools and channels, and then identifying the concept of salary localization, its importance, objectives and obstacles to its application, and then analyzing the reality of the state of the settlement of salaries and bank deposits for the research sample banks, which are each of the bank (Ashur International, Business Bay, the Iraqi Middle East for Investment, the Iraqi National, Development and the
... Show MoreThe environmental contamination by the polycyclic aromatic hydrocarbons (PAHs) and heavy metals (Pb, Cu, Ni, Cr, and Cd) concentrations in the leaves of plant Eucalyptus camaldulensis were determined at the city of Kirkuk in 15 selected locations using GPS. The pickings up of samples were carried out in two periods October 2010 and March 2011. Compared with results of other studies, the concentration levels of determined heavy metals show values within these studies results. The average total concentration of polycyclic aromatic hydrocarbons (PAHs) in the leaves of Plant Eucalyptus camaldulensis indicated 37.1 ppb in October, while in March 165.2 ppb.
The mode
... Show MoreThis experiment was carried out at the Grdarash field belongs to the Agricultural researches directorate/general Agriculture directorate-Erbil in September (2007)، 27 Arabic lambs aged (5-6 months) With average initial weight (39.178 Kg/lamb) were used. Lambs were divided in to (3) groups (9 lambs/group). Control group was fed on (85% barely، 10% bran and 5% straw)، and second and third groups were fed on various by-product in replacement with barely in loss and block shape respectively.
The total gain of three groups were (392708.32، 634826.52 & 445613.72 ID resp
... Show MoreDiatoms are considered a potentially new and valuable source of biologically active compounds including those with antimicrobial properties; so, this study was conducted to evaluate the antibacterial activity of Navicula incerta. The diatom was isolated from the salt water of Sawa Lake, southern of Iraq, it was cultivated in salt water then was adapted and cultivated in freshwater environment; the harvested and dried biomass was extracted, and the antibacterial activity of each extract was evaluated against several species of pathogenic bacteria. The chemical constituents of the extracts were also analyzed using Gas chromatography/Mass spectrometry technique. Generally, the result showed that fresh water extract of N. incert
... Show MoreThe northern region of Algeria is experiencing a real threat to the spatial extension of soil erosion. The Oued Bouhamdane watershed, part of this region, brings together all the natural and anthropogenic conditions that accelerate its degradation. This study is based on the use of remote sensing and GIS to map soil erosion in the Oued Bouhamdane watershed in north-eastern Algeria, using the Gavrilovic equation. The combination of data from different sources and field observation has made it possible to draw up a contextualized map of all the factors of soil erosion. Integrating the model into the GIS made it possible to give a first estimate of the annual volume of eroded soils, i.e., 14.57% of the total area of the Oued Bouham
... Show MoreAmara oil field is located at south eastern Iraq in Missan governorate. The Mishrif Formation in Amara field is one of the most important reservoirs in southern Iraq. Identifying and characterizing petrophysical flow units are the key to understanding and improving reservoir description, exploitation, production and predicting the performance of carbonate reservoirs to represent them as combinations of different flow units, each with uniform pore throat size distribution and similar performance. Mishrif Formation in Amara oil field was divided into seven reservoir units (MA.MB11,MB12,MB13,MB21,MC1, and MC2) separated between them barrier beds. The present work is a reservoir flow unit identification for (MA) and (MB11) reservoir units of
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