Self-compacted concrete (SCC) is a highly flowable concrete, with no segregation which can be spread into place by filling the structures framework and permeate the reinforcement without any compaction or mechanical consolidation ACI 237R-14. One of the most important problems faced by concrete industry in Iraq and Gulf Arab land is deterioration due to internal sulfate attack (ISA) that causes damage of concrete and consequently reduces its compressive strength, increases expansion and may lead to its cracking and destruction. The experimental program was focused to study two ordinary Portland cements with different chemical composition with (5, 10 and 15) % percentage of high reactivity metakaoline (HRM) as a cement replacement and with W/Cm ratio 0.35. The SCC mixes with AL Shemalia OPC cement that produced in Saudi Arabia (C3 A=7.02%) shows higher resistance to ISA than mixes with Tasluja OPC cement that is produced in Iraq (C3 A=4.13%). The results indicate that the SCC mixes containing 15% HRM shows higher opposition to ISA. A good correlation was obtained between concrete splitting tensile strength and compressive strength from the results of this study.
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In this investigation, the mechanical properties and microstructure of Metal Matrix Composites (MMCs) of Al.6061 alloy reinforced by ceramic materials SiC and Al2O3 with different additive percentages 2.5, 5, 7.5, and 10 wt.% for the particle size of 53 µm are studied. Metal matrix composites were prepared by stir casting using vortex technique and then treated thermally by solution heat treatment at 530 0C for 1 hr. and followed by aging at 175 0C with different periods. Mechanical tests were done for the samples before and after heat treatment, such as impact test, hardness test, and tensile test. Also, the microstructure of the metal matrix composites was examine
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Aims: This study was conducted to assess the effect of the addition of yttrium oxide (Y2O3) nanoparticles on the tensile bond strength, tear strength, shore A hardness, and surface roughness of soft-denture lining material. Materials and Methods: Y2O3 NPs with 1.5 and 2 wt.% were added into acrylic-based heat-cured soft-denture liner. A total of 120 specimens were prepared and divided into four groups according to the test to be performed (tensile bond strength, tear strength, surface hardness, and surface roughness). Results: There was a highly significant increase in tensile bond strength between the soft liner and the acrylic denture base, tear strength, and hardness at both concentrations as compared to the control group, whereas ther
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Background In recent years, there has been a notable increase in the level of attention devoted to exploring capabilities of nanoparticles, specifically gold nanoparticles AuNPs, within context of modern times. AuNPs possess distinct biophysical properties, as a novel avenue as an antibacterial agent targeting Streptococcus Mutans and Candida Albicans. The aim of this study to create a nano-platform that has the potential to be environmentally sustainable, in addition to exhibiting exceptional antimicrobial properties against Streptococcus Mutans as well as Candida Albicans. Methods this study involved utilization of
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This study has been performed to study the inhibitory effects of crude plant extracts of Bay (laurus nobilis) leaves against some bacterial isolates represented by Staphylococcus aureus, Staphylococcus epidermids, Proteus vulgaris, Bacillus subtilis, Escherichia coli, and Pseudomonas aeroginosa in vitro. The results showed that percentages of essential chemical of laurus nobilis leaves which represented by moisture, total oil, total ash, crude protein, crude fibers, carbohydrites and caloric values in dry weight are 5.96, 4.28, 14.2, 8.75, 24.8, 76.99%, and 284.92 kcal/100g respectively, the percentages of some major and minor mineral elements of laurus nobilis leaves powder which represented by Mg, Fe, Cu, Pb, Cd and As, are: 0.211, 0.1
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Abstract
Personality is one of the most important elements that should be developed in university student. Thus, we have to develop the positive traits and neutralize the negative traits of students as well as we have to pay attention to the level of student achievement at the same time, the researcher designed a scale to measure the traits of study sample. The research come out with a number of recommendations and proposals, the most important of which Enhancing the positive characteristics of university students in order to reach them to the level of mature personality with mental health. Enhancing the positive role of the high level of achievement by motivating the stude
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