This research includes a study of dezincification by corrosion from brass alloys in three types of media, which are acidic solution, basic and slat solution in different percentages. The study show the higher dezincification occurs in basic solution which decrease the fatigue properties where the fatigue properties are inversely proportional with dezincification.

Abstract

The intellectual capital an important variable in the equation of the success of seeking economic units to achieve a competitive advantage, since it is a real capital for economic unity it constitutes a strategic importance as the main source to achieve high profitability in the economic unit and highlights the importance of showing intellectual capital components of the main Represent of human capital and structural capital and relational capital, through effective and the prominent role played by intellectual capital within the economic unity in order to achieve a sustainable competitive advantage contribute to attracting investors with longer investment decision of the most important and difficult decisions ta

 This research was to determine the effect of rare earth metal (REM) on the as-cast microstructure of Mg-4Al alloy. The rare earth metal used here is Lanthanum to produce Mg-4Al-1.5La alloy. The microstructure was characterized by optical microscopy. The phases of this alloy were identified by X-ray diffraction. The microstructure of Mg-4Al consists of α-Mg and grain boundaries with precipitated phase particles. With the addition of Lanthanum, three distinct phases were identified in the X-ray diffraction patterns of the as cast Mg-4Al-1.5La:  Mg, Al₁₁La₃, Al₄La. The Mg₁₇Al₁₂ phase was not detected. The addition of Lanthanium increases the hardness and dec

Background: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u

The Internet, networks and the means of communication in the world of communication and information have greatly influenced all aspects of the information cycle until things have been turned upside down, and it has even been said that today the world can be separated into two worlds: the world of pre-internet and post-Internet.

Perhaps one of the most important data of the Internet in the world of information and journalism is electronic publishing, which comes blogging as one of its forms. Blogs, which have begun slowly in the form of personal diaries, developed and spread on the Internet very quickly and started to have its own universe, the world of blogging. It has begun to make its way in the world of journali

يتمثل الهدف الأساسي من الرقابة علىٰ تركز الشركات في منع آثارها المحتملة غير التنافسية الضارة بالهيكل التنافسي للسوق المعنية، وذلك لحماية حرية المنافسة فيها. وفي إطار ذلك لا بد من التحقق من أن تلك العمليات ليس من شأنها إعاقة المنافسة الفعّالة أو الحد منها بشكل كبير علىٰ نحو يترتب عليه التأثير علىٰ السوق المعنية بجعلها أقل قدرة علىٰ المنافسة مما كانت عليه، أي ضرورة التنبوء بكافة الآثار المحتملة التي ستترتب عل

Urbanization can not be seen as a modern phenomenon. It has led people to live and live in cities for thousands of years. It should be noted here that the oldest villages and large cities have emerged after the crystallization of civilization, that the emergence of cities was one of the phenomena of civilization. There is no doubt that the cities after the emergence has contributed to the development of civilization effective contribution. There has been a civilizational progress when the man practiced agriculture and used metal tools and invented the wheels and went to write in the New Stone Age. In this period, many changes in the field have taken place in economic, cultural and social life. In the economic and cultural aspect, this tr

The importance of television has emerged as an effective and influential force in the lives of societies and peoples, And not just a professional media since the fifties of the twentieth century, It was used as a platform to achieve the goals and objectives of the media and politics for governments, agencies and individuals in different countries of the world, Using many methods, methods and techniques that later became important major subjects and curricula and a scientific specialization that was founded for him to study and teach in most international universities, The media, especially television and satellite channels, play an active and significant role in managing crises and conflicts and directing them through the methods of deal

    The research specified with study the relation  between the market share for the sample research banks and the amount of the achieved revenues from the investment, where the  dominated belief  that there potentiality enhancing the revenue on investment with the increase of the banks shares in their markets after their success in achieving rates of successive growth in their sales of sales and to a suitable achieve  market coverage for their products and they have dissemination and suitable  promotion activity, the  market share represented the competition  for the banks, and the markets pay attention to the  market share as a strategic objective and to maintain them also increasi

The electrochemical behavior of Al-17%Si alloy is investigated in 3.5wt% NaCl solution. Many alloys with addition of the different wt% magnesium metal of  1wt%, 2%, 3wt% ,4.5wt% ,and 9wt% were prepared by gravity die casting . The microstructures of prepared alloys were examined by optical and SEM microscopes. Corrosion behavior was investigated by using potentiostat instrument under static potentials test and corrosion current was recorded to determine corrosion resistance of all prepared samples. It was found that the addition of Mg metal improves the corrosion resistance of Al-17%Si alloy in 3.5%NaCl solution. The alloy containing 1%Mg shows less corrosion rate than the others while the alloys containing 4.5%Mg, 9%Mg content have