The objective of the study is developing a procedure for production and characterization of rice husk ash (RHA). The effects of rice husk (RH) amount, burning/cooling conditions combined with stirring on producing of RHA with amorphous silica, highest SiO2, lowest loss on ignition (LOI), uniform particle shape distribution and nano structured size have been studied. It is concluded that the best amount is 20 g RH in 125 ml evaporating dish Porcelain with burning for 2 h at temperature 700 °C combined with cooling three times during burning to produce RHA with amorphous silica, SiO2 90.78% and LOI 1.73%. On the other hand, cooling and stirring times affect the variation of nano structured size and particle shape distribution. However, no crystalline phases were found in RHA in all cases. Results proved that the Attritor ball mill was more suitable than vibration disk mill for pulverizing nano structured RHA with 50% of particle size (D50) lower than 45 mm and 99 % of particle size (D99) lower than 144 mm to nanosized RHA with D50 lower than 36 nm and D99 lower than 57 nm by grinding time 8.16 min to every 1 g RHA without changes in morphousity of silica.
This research aims to modify the components of stainless steel alloy by the method of surface engineering through the single diffusion coating technique in order to obtain new alloys with high efficiency in resisting harsh environmental conditions. Steam a mixture of sodium chloride ( ) and sodium sulfate ( ) at a temperature of 900 and then compare it with the base alloy. The results showed that the alloys produced in this way are very efficient. The results showed that the aluminum coating showed high efficiency in resisting oxidation and provided better protection for a longer time compared to the uncoated alloy due to the oxide crust layer formed with high adhesion as well as the aluminum-rich phases, whether the phase
... Show MoreThe Arabs muslim , throughout the historical ages, had many and varied contributions in various fields of science and knowledge, and in all scientific disciplines. They were preceded by scholars of other sects, so their books were translated into Arabic and they added to it many of their scientific research and writings that affected Arab and Islamic libraries, as these scientific research turned into basic references for the benefit of students of science in this field, and they did not stop at that, but built observatories, and invented They developed many astronomical devices in their time and observed the planets and stars, drew maps for them and determined their locations
The great challenge that will face the management in the developed and developing countries at the same time as core issue is represented in the question of the labor productivity in the field of in the Training Of human which is believed that it will prevail upon the jobs of their organization for many coming decades in in next years. Farther more, it will limit the construction of the communities and the quality of this life. Therefore, the priority of the economics of those countries will be headed toward increasing this productivity and giving it tried finally to control economically and managerially. In the light of information era, every organization should become knowledgeable enterprise. And for this reason, the achievement of su
... Show MoreThe stress(Y) – strength(X) model reliability Bayesian estimation which defines life of a component with strength X and stress Y (the component fails if and only if at any time the applied stress is greater than its strength) has been studied, then the reliability; R=P(Y<X), can be considered as a measure of the component performance. In this paper, a Bayesian analysis has been considered for R when the two variables X and Y are independent Weibull random variables with common parameter α in order to study the effect of each of the two different scale parameters β and λ; respectively, using three different [weighted, quadratic and entropy] loss functions under two different prior functions [Gamma and extension of Jeffery
... Show Moreتعد الثقافة التنظيمية في المجال االداري وكذلك الرياضي من المفاهيم الحديثة لذا وجب التعرف عليها من عدة اتجاهات لمعرفة تكوينها واب عادها والنظريات التي تناولتها لتكوين رؤية تختلف عن االخرين لما لها من دور مهم ونافع في مختلف المؤسسات ومنها االتحادات الرياضية، ولعل لعلوم الرياضة واالختبار والقياس على وجه الخصوص الدور الرئيس في المساعدة بإيجاد وسيلة علمية وتطبيقها على االعضاء لمعرفة انماط الثقافة لديهم ومن
... Show MoreThe study falls in Five chapters as follows:
Chapter One : definition of the Study including:
1. The problem of the study: the current study tries to answers two questions;
First: the effectiveness of the performance of the applicants in the department of Quran
Sciences and Islamic Education in the colleges of Education according the point of view of
their supervisors.
Second: what is the future vision for teacher training according to the assessment of the
performance of the applicant students?
2. The importance of the study: the application or the field training is of an important role
in the process of training the students for teaching; as it is considered the real scale of
success in the processes of ac
E.M. Forster (1879-1970) is one of the important novelists who dealt with the personal and social lives of the people in England during the early beginning of the twentieth century. During his literary career, he developed gradually his views about man and his position in society.
In his first novel, Where Angels Fear to Tread (1902), the focus is laid on local and personal issues in the lives of the characters. It is limited to the relations between neighbours in small communities. Though the setting is shifted to Italy, Forster does not make full use of this shift to present cultural or racial conflicts; rather he limits his plot to the private tr
... Show MoreWater resources would be differentiate in Morocco specially in Morocco which appear as form of eyes ,rivers as dissolved water of mountain.
The human takes care of water either as rains to store and use in necessity trying to bring it to Maracas by helping from state .
The religious tried to dig wells to emphasize that water is rumored and do not monopolized.
Knowing the conduct of the common stocks during the different intervals of time (quarterly and yearly) is an important step in choosing and administrating the portfolio of common stocks which be in accordance with the tendency of the investor toward risk and revenues. This is an attempt to understand the behavior of this common stocks in Amman stock Exchange to discover the extent of change in its behavior for employing them by the managers in identifying the accurate and beneficed investments , which meet the ambitions of Arab investor.