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.
لقد نشا علم التحقيق على ايدي المحدثين المسلمين الذين وضعوا قواعد هذا العلم وظهرت مؤلفات عدة في هذا المجال ، لكن ما قام به الاقدمون لم يشكل قواعد علم مستقل بذاته ومنذ ظهور الطباعة بدأت حركة تحقيق المخطوطات ، وتعددت مناهج التحقيق فكان للمستشرقين منهجهم الخاص وظهر منهج التحقيق والاخراج الفني والعلمي للمخطوط .
We have studied in this research litter (Taa) a morphological , sonic indicative and comparative study among four Semitic languages. They are Arabic , Hebrew, Syriac and Akkadian languages . We have divided the research into a number of pivots beginning with an entrance about the letter (Taa) in Semitic languages and the symbols which are used by these languages referring to . Then we have studied (Taa) from sonic side with letters phenomenon (b, g, k, p, t) the six in both Hebrew and Syriac languages . The letter (Taa) is formed one of them and the sonic change that is happening in articulation (Taa) according to sonic rules related to these letters in case of emphasis or in case of neglected (not emphasis). Then we have studied the pro
... Show MoreWisdom in the era before Islam is soo famous and so mature And Wisdom in the age of Islam {the holy quran and AI Hadeeth AI shareef }is dealt with by different meanings that agree with the contexts in which it occurs its contacs One of meanings is wisesaying that occuars in the Halal and Haram .As to the wisdom of the Amawy age ,it was some times absent since it was not dealt with by the great Poets of that age .In the Poetry of AL-FARAZDAK , Wisdom was little and it expressed religious and phsycological meanings because wisdom is amessage that has along –rang .
لاحظ صناع القرار السياسي عدم مشاركتهم لمجموعة من الطوائف الاجتماعية في صنع القرار السياسي للدولة، مما دفعهم لتقوية هذه الطوائف، وتمت التدقيق في الجانب النسوي وعدم مشاركتهم في اتخاذ القرارات رغم الفئة الكبير منهم في المجتمع، مما أدى لاتخاذ أنظمة تساعد على تمثيل هذه الفئة في الحكم النيابي من خلال نظام الكوتا.
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)
عرض كتاب المدخل الى دراسة الاستراتيجية
There are many questions that have been presented and asked in order to know who the Lady Sharifa bint Al-Imam (peace be upon her) is? And then adopting the opinions that confirm or deny the existence of Mrs. Sharifa or the place of her death, and how did it happen? As well as the question, where is the shrine of Sharifa, daughter of Imam Hassan? Who are the daughters of Imam Hassan? Did she have a grave previously, and when was the trace of this tomb known