The ceramic compound Mg1-xSixAl2O4 (x= 0, 0.1, 0.2, 0.3, 0.4) was prepared from nano powder of Al2O3 and MgO doped with Nano powder of SiO2 at different molar ratios. The specimens were prepared by standard chemical solid reaction technique and sintered at 1450 oC. Structure of the specimens was analyzed by using X-ray diffraction (XRD). The X-ray patterns of the specimens showed the formation of pure simple cubic spinel structure MgAl2O4 phase with space group of ̅ . The average grain size and surface topology were studied by atomic force microscopy. The results showed that the average grain size was about 73-90 nm. The DC electrical properties of the specimen were measured. The apparent density was found to increase and the porosity and water absorption were found to decrease with increase of Si addition. Mechanical properties were characterized by Vicker’s micro hardness and Brazilian fracture test to measure the fracture toughness of the samples. The micro hardness decreased with Si addition increase. Fracture toughness increased with the increase in Si addition.
Objectives. This study aimed to evaluate the impact of nonnutritive sucking habits on the presence of oral Escherichia coli. Methods. One hundred and twenty children aged 3–5 years old were enrolled in the present case-control study, as follows: 60 children with continuous pacifier and thumb sucking habits (study group) and 60 children without any sucking habits (control group). The children in the two groups were matched in terms of age and gender. Information was gathered from the parents concerning their children using a special sheet. Sterile swabs were taken from both groups and cultured on agar plates. Then, they were subjected to further biochemical tests to identify E. coli species. The mean of the E. coli count was determ
... Show MoreMotives: Baghdad is the capital city and an important political, administrative, social, cultural and economic centre of Iraq. Baghdad’s growth and development has been significantly influenced by efforts to accommodate various needs of its steadily growing population. Uncontrolled population and urban growth have exerted negative effects in numerous dimensions, including environmental sustainability because urban expansion occurred in green spaces within the city and the surrounding areas.Aim: The aim of this study was to examine the planning solutions in Baghdad’s green areas in the past and at present, and to identify the key changes in the city’s green areas, including changes in the ratio of green urban spaces to the tota
... Show MoreThe present investigation considers the effect of curing temperatures (30, 40, and 50˚C) and curing compound method on compressive strength development of high performance concrete, and compares the results with concrete cured at standard conditions and curing temperature (21˚C). The experimental results showed that at early ages, the rate of strength development at high curing temperature is greater than at lower curing temperature, the maximum increasing percentage in compressive strength is 10.83% at 50C˚ compared with 21C˚ in 7days curing age. However, at later ages, the strength achieved at higher curing temperature has been less, and the maximum percentage of reduction has been 5.70% at curing temperature 50C˚ compared with 21
... Show MoreFinancial inclusion refers to the access of financial services at low cost and high-quality from the formal financial sector to all segments of society, especially marginalized groups, and then use and benefit from them. Financial inclusion is also associated with banking stability, as well as with financial integrity and financial protection for the consumer, therefore, it achieves a number of objectives, the most important of which is to support and enhance banking stability. This is what made it attract the attention of many countries and central banks recently.
The study aims to show the impact of financial inclusion indicators on ban
... Show MoreSand dunes are spread in multiple places in the world especially in a desert area as a result of economic development and construction processes, there was a need to study the behavior of sand dunes and make it suitable for construction. This paper aims to study the effect of adding sodium silicate on the cohesion strength of sand dune and its behavior. The results show that the cohesion strength increase as a percentage of sodium silicate increase (addition 8% Sodium silicate show the higher cohesion) and the cohesion between sand dune particles increase excepted when using 10% sodium silicate the cohesion began to decrease. However, the effect of curing time is significant and shows
Recently, interest in the use of projectiles in research on recycling waste materials for construction applications has grown. Using recycled materials for the construction of asphalt concrete pavement, in the meantime, has become a topic of research due to its significant benefits, such as cost savings and reduced environmental impacts. This study reports on comprehensive experimental research conducted using a typical mechanical milling waste, iron filing waste (IFW), as an alternative fine aggregate for warm mix asphalt (WMA) for pavement wearing surface applications. A type of IFW from a local machine workshop was used to replace the conventional fine aggregate, fine natural sand (FNS), at percentages of 25%, 50% 75%, and 100% b
... Show MoreA hand lay-up method was used to prepare Epoxy/ metal composites. Epoxy resin (EP) was used as a matrix with metal particles (Al, Cu, and Fe) as fillers.
The preparation method includes preparing square panels of composites with different weight percentage of fillers (10, 20, 30, 40, and 50%). Standard specimens (88mm in diameter) for thermal conductivity tests were prepared to measure thermal conductivity kexp.The result of experimental thermal conductivity kexp, for EP/metal composites show that, kexp increase with increasing weight percentage, For EP/ Al and EP/Cu composites, and it have have maximum values of 0.33 and 0.35 W/m.K, respectively. While kexp for EP/ Fe composite show slight increase with maximum value of 0.186 W/m.K.
This work aims at finding out the impact of teaching types blended learning strategies on academic students` achievement. A review of related literature indicates that almost no study has ever attempted to focus specifically on the effect of the different kinds of blended learning strategies on EFL students` achievement in the educational research writing, and the present study attempts to fill this gap. The study focused on the students at the Master's degree in Educational Research Writing in the first semester of the academic year 2020/2021. The sample has selected from the college of Education Ibn-Rushd (18) students. Material has been designed for the Master candidates’ participants of the study was divided into two groups: one an e
... Show MoreEP/ metal composites were prepared as adhesives between two steel rods. Epoxy resin (EP) was used as a matrix with metal as fillers (Al, Cu, Fe,).
The preparation method for tensile adhesion tests includes two steel rods with adhesive composites between the rods to measure adhesion strength Sad and adhesion toughness Gad.
Results of tensile adhesion tests show that EP/ metals composite have maximum strength Sad for certain weight percentage of metals 2.95 and 9MPa at 10% for EP/Al and EP/Cu composite and 8.2MPa at 40% for EP/Fe composites
Kombucha(Khubdat Humza) is composed of yeast and acetic acid bacteria especially, Acetobacter xylinum which forms a cellulose pellicle on tea broth. Kombucha(Khubdat Humza) produces bacterial cellulose pellicles, with unique purity and fine structure. It can be used in many forms, such as an emulsifier, stabilizer, dispersing agent, thickener and gelling agent but these are generally subsidiary to its most important use of holding on to water. Recently, bacterial cellulose is used in many special applications such as a scaffold for tissue engineering of cartilages and blood vessels, also for artificial skin for temporary covering of wounds, as well as its used in the clothing industry. The yield of cellulose produced were investiga
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