This paper deals with the modeling of a preventive maintenance strategy applied to a single-unit system subject to random failures.

According to this policy, the system is subjected to imperfect periodic preventive maintenance restoring it to ‘as good as new’ with probability

p and leaving it at state ‘as bad as old’ with probability q. Imperfect repairs are performed following failures occurring between consecutive

preventive maintenance actions, i.e the times between failures follow a decreasing quasi-renewal process with parameter a. Considering the

average durations of the preventive and corrective maintenance actions a

Abstract The present study was Conducted to evaluate the effect of amixture of three species of arbuscular mycorrhizal fungi ( Glomus etunicatum , G. leptotichum and Rhizophagus intraradices ) in inducing the non-enzymatic antioxidants of tomato roots infected with Fusarium oxysporum f.sp. Lycopersici wich cause Fusarial wilt disease , and planted for 10 weeks in the presence of the organic matter ( peatmose) , using pot cultures in aplastic green house , Results indicated significant reduction of disease incidence percentage and infection rate of roots infected with the pathogen 4 weaks after mycorrhizal colonization in all treatments ( single , dual and trial interactions) . on the other hand mycorrhizal colonization of the roots in the

مستخلص البحث. يهدف البحث الحالي التعرف على: ١ – الاستدلال التمثيلي لدى الطالب- المدرس في كلية التربية للعلوم الصرفة/ ابن الهيثم. ٢ –الفروق ذات الدلالة الاحصائية في الاستدلال التمثيلي وفق متغير الجنس ( ذكور، إناث) لدى الطالب- المدرس في كلية التربية للعلوم الصرفة/ ابن الهيثم. تألفت العينة من ( ١٥٠) طالب وطالبة من طلبة المرحلة الرابعة- لقسم الكيمياء/ ابن الهيثم، وتم اختيارهم بالطريقة العشوائية البسيطة، بواق

هدفت الدراسة إلى بناء برنامج التدخل المبكر نموذج دنفر على وفق أساليب معرفية سلوكية، والتعرف على اثر البرنامج في تنمية المهارات الاجتماعية لدى أطفال التوحد الافتراضي ولتحقق من هذا الهدف وضعت الباحثة الفرضية الآتية لا توجد فروق ذو دلاله إحصائية بين متوسط رتب درجات أفراد المجموعة التجريبية في التطبيقين القبلي والبعدي على المقياس (CARS2-ST). اقتصر البحث الحالي على الأطفال من ذوي اضطراب التوحد الافتراضي المسجل

تلعب السياسة النقدية دوراً فاعلاً ومتميزاً في تحقيق معدلات نمو عالية وتحقيق الاستقرار والتوازن الاقتصادي وبالاخص الحد من ظاهرة التضخم.

يمكن حصر اهداف السياسة النقدية في الدول النامية والعربية خصوصاً من خلال التعرف على الاغراض المنصوص عليها في التشريعات وتشمل (تحقيق استقرار نقدي، المحافظة على قيمة العملة، تشجيع النمو الاقتصادي، تطوير الاسواق المالية والنقدية، استقرار الاسعار، تحقيق ال

The problem of the current research has been crystallized through the study of the current reality of teaching Islamic Education in the intermediate schools. In order to get realistic results and to built on them the recommendations and suggestion that might help in improving teaching Islamic Education with more effective styles in the intermediate and secondary schools, this research has been formulated with the following question:

What are the common methods and styles used in teaching Islamic Education in the intermediate schools?

The importance of the research can be summarized as follows:

1. The importance of the Islamic Education according to its

After the fall of the Third Dynasty of Ur at the hands of the Elamites during the reign of its last ruler, King Ibi-Sin, the Amorites continued to flow more into Mesopotamia in the form of large migrations that established a number of contemporary and conflicting ruling dynasties that formed the Old Babylonian era. Among these dynasties was the Larsa dynasty, founded by King Nablanum in the city of Larsa. The fourth king who ruled in the Larsa dynasty, Gungunum, was one of the most powerful kings who stood up to the Isin dynasty, which had until that time enjoyed great political superiority in the country. The kings who ruled after him expanded their influence and controlled a number of cities, especially the cities of Nippur and Uruk, whic

The study aims to determine the responsibility of nursing staff for medical errors that accompany the surgery at the hospital , which is one of the important issues that the importance of determining the responsibility of landlords nursing medical errors in the hospital was the rationale in choosing the subject. Since study included cases of errors nursing staff of (22) case. While the checklist distributed to a sample of nursing Angel Group in Sadr Teaching Hospital 's (100) nurs According to the problem, the study in determining the responsibility of nursing staff for medical errors that are not important for the hospitals. Has shown results of the study agreement members of the study sample that the clarity of the power posses