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.
Abstract: In accordance with contemporary Western thinking, power is an organized force with a high ability to achieve stability and social security because it possesses tools based on rational organization, which helps it to control the behavior of the individual and society and prevent them from practicing the processes of exclusion and discrimination against others in pursuit of their interests and needs. Vision The philosophers and thinkers of the theory of social contract can consolidate it, which changed the form and nature of power from the traditional heritage to the constructionWhich has contributed to the development and development of civil society - Western political, and despite the success of this experiment, especially aft
... Show MoreThe metric dimension and dominating set are the concept of graph theory that can be developed in terms of the concept and its application in graph operations. One of some concepts in graph theory that combine these two concepts is resolving dominating number. In this paper, the definition of resolving dominating number is presented again as the term dominant metric dimension. The aims of this paper are to find the dominant metric dimension of some special graphs and corona product graphs of the connected graphs and , for some special graphs . The dominant metric dimension of is denoted by and the dominant metric dimension of corona product graph G and H is denoted by .
In this research was study the effect of increasing the number of layers of the semiconductor films as PbS on the average grain sizes and illustrate the relationship between the increase in the average grain size and thickness of the membrane, and membrane was prepared using the easy and simple and does not need the complexity of which is that the chemical bath , and from an X-ray diffraction found that the material and the installation of a random cubic and when increasing the number of layers deposited note the emergence of a number of vertices of a substance and PbS at different levels but the level is more severe (200) as well as the value is calculated optical energy gap and found to be not affected by increase thickness and from th
... Show MoreThe research entitled "the Iraqi Topics in International Arab Press" is an analytical study of two newspapers: Al-Arab and Al-Hayat published in London from September 1-30, 2013.
The Arab press is one of the cultural monuments Home stretches for culture and media of Arabs outside the Arab Homeland which made them international press targeting public Arab audience's not civil audiences in a particular country and formulating their contents on this basis taking into account intake affairs and issues that have been national or international.
Because of this international presence of the Arab press, these newspa
... Show MoreFlourished economic life in the city Asturabaz was the main engine of social and political conditions in the city; In order to provide factors to help the successful cultivation of the city as well as the prosperity of the industry as famous city Asturabaz since ancient times textile industry and won wide acclaim as well as leather and wood industries and the pharmaceutical industry industry in addition to the livestock that have contributed to increased imports of the city, and this led to the prosperity of the evolution of physical movement and intellectual life.
Of non-Muslim minorities In the Muslim community