A real method of predication brake pad wear ,could lead to substantiol economies of time and money. This paper describes how such a procedure has been used and gives the results to establish is reliability by comparing the predicted wear with that which actually occurs in an existing service. The experimental work was carried out on three different commercial samples ,tested under different operation conditions (speed,load,time...etc)using a test ring especially modified for this purpose. Abrasive wear is mainly studied , since it is the type of wear that takes place in such arrangements. Samples wear tested in presences of sand or mud between the mating surfaces under different operational conditions of speed, load and braking time .Mechanical properties of the pad material samples (hardness, young,s modulus and collapse load under pure bending condition )wear established . The thermal conductivity and surface roughness of the pad material wear also found in order to enable comparison between the surface condition before and after testing. Sliding velocity had a small effect on the wear rate but it had great effect on friction coefficient. Wear rate was affected mainly by the surface temperature which causing a reduction friction coefficient and increasing the wear rate. Surface roughness had almost no effect on the wear rate since it was proved experimentally ,that the surface becomes softer during operation .mechanical properties of the pad material had fluctuating effect on wear rate. The existence of solid particles between pad and disc increasing wear rate and friction coefficient while the mud caused a reduction in wear rate of the pad surface since it acts as a lubricant absorbing the surface heat generated during sliding the area of contact between pad and disc. wear rate obtained experimentally agreed fairly well that found from empirically obtained equations.
The spatial variation of regional development means that some regions to be a center of activities and services and job opportunities and economic development, and are usually in major urban centers, while lacking in other regions to such activities and services. Perhaps the studies of spatial variation SPATIAL INEQUALITY, regional development, REGIONAL DEVELOPMENT has had the greatest impact on the operations of regional planning in particular the study of the regional dimension of any city requires that you review the basis and theoretical framework, which refers to the inevitability of the existence of disparities across regions, due to the properties of the regions population and economic political and environmental The study
... Show MoreIn this research the natural frequency of a cracked simple supported beam (the crack is in many places and in different depths) is investigated analytically, experimentally and numerically by ANSYS program, and the results are compared. The beam is made of iron with dimensions of L*W*H= (0.84*0.02* 0.02m), and density = 7680kg/m3, E=200Gpa. A comparison made between analytical results from ANSYS with experimental results, where the biggest error percentage is about (7.2 %) in crack position (42 cm) and (6 mm) depth. Between Rayleigh method with experimental results the biggest error percentage is about (6.4 %) for the same crack position and depth. From the error percentages it could be concluded that the Rayleigh method gives
... Show MoreCommunication has seen a big advancement through ages; concepts, procedures and technologies, it has also seen a similar advancement of language. What unites language and media is the fact that each one of them guides and contributes to the other; media exists and results from language and from the other sign systems, and what strengthens this connection is the symbolic language system, as media helps it by providing knowledge and information. The change that occurred through time must leave a significant trace in the media, for example Diction, which has changed concerning development and growth, also the ways and mediums of media have become manifold and widespread. This change affected the recipient whether it was a reader, listener o
... Show Moreيعد موضوع التنافس بين القوى الكبرى من الموضوعات المستقبلية المهمة التي تؤشر لنا جانبا من صور العلاقات الدولية التي تتسم بالصراع والتعاون من ناحية، والتعاون والتنافس من ناحية أخرى، وبقدر تعلق الموضوع بالمنطقة العربية التي تعد إحدى أهم المناطق العالمية إثارة في مستوى التفاعلات بأنساقها المختلفة، كونها منطقة لازالت محكومة بعوامل غير مستقرة، تشكل نافذة فاعلة لتدخلات القوى الكبرى الساعية إلى إعادة تشكيل المد
... Show Moreيعد موضوع المحل من المواضيع الشائكة في القانون المدني ، اذ ان هذا الموضوع رغم قدمه الا انه لازال يمثل ارضا خصبة للبحث ، اذ يوجد خلاف حول تحديد الكائن القانوني الذي يعد المحل ركنا فيه ، حيث اختلفت التشريعات في هذه المسألة ، فبعض التشريعات تذهب الى ان المحل ركن في العقد ، وبعضها يذهب الى ان المحل ركن في الالتزام ، وبعضها يذهب الى ان المحل ركن في العقد وركن في الالتزام وقد انتقل هذا الخلاف الى الفقه فظهر فيه عدة اتج
... Show MorePraise be to God, Lord of the worlds, and may blessings and peace be upon the most honorable of all creation, Abi Al-Qasim Muhammad, who is the messenger of mercy to the worlds and upon the God of the pure and good companions all
احكام التركز الاقتصادي للمشاريع دراسة مقارنة
The main purpose of this study is to investigate the relationship between smoking and increased risk if diseases.
It has been estimated that gland of smoker in the world 3.1 billion smoker . Glands an estimated 4.1 million deaths per day . The proportion of death in developing countries 70% due to relationship between poverty and smoking .
The damage caused by smoking not only no the Alzbn users , but to millions of people around them .
According to medical studies to confirm the relationship between forced smoking and increased risk of heart diseases , lung cancer , and mental diseases . it is surprising
... Show MoreThis is a research that deals with one of the topics of Arabic grammar, namely, the plural noun, and it is not hidden from the students the importance of grammatical topics in preserving the tongue from melody, and what it has of fundamental importance in knowing the graphic miracles of the Qur’an, and I called this research:
(plural noun in Arabic a grammatical study)
Stop the search on the performance of the stylistic literary messages sent by
Abu Mohammed Amer bin Said Altakrna to the kings of his time and Ullach
highlighting the method of the three levels is psychological and away the consignee
and the receiver Taster literary text.
Level voice and rhythmic, which dealt with (alliteration and Naturalization
voice, and repetition and parallelism, and rhyme and toning) and its impact on the
taste and the emotional art between the sender and the receiver Bashklah.
Who has studied the structural level (introductory sentence order methods in the
messages, generally have much style presentation and brief delays and actor, and
then end the moral and intellectual martyrdom and de