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ﻟﻘﺩ ﺯﺍﺩ ﺍﻻﻫﺘﻤﺎﻡ ﺍﻟﻌﺎﻟﻤﻲ ﺍﻟﻤﻨﺼﺏ ﻋﻠﻰ ﺍﻵﺜﺎﺭﻭﺫﻟﻙ ﻟﻤﺎ ﻟﻬﺎ ﻤﻥ ﻗﻴﻤﻪ ﺘﺎﺭﻴﺨﻴﺔ ﻭﻓﻨﻴﺔ، ﻓﻀﻼﹰ ﻋﻠﻰ ﺃﻨﻬﺎ ﻤﻥ ﺍﻟﺭﻜﺎﺌﺯ ﺍﻷﺴﺎﺴﻴﺔ ﻟﻠﺩﺨل ﺍﻟﻘﻭﻤﻲ ﻟﻌﺩﻴﺩ ﺍﻟﺩﻭل، ﻭﻓﻲ ﻟﻴﺒﻴﺎ ﻭﻋﻠﻰ ﺍﻟﺭﻏﻡ ﻤﻤﺎ ﺘﺯﺨﺭ ﺒﻪ ﻤﻥ ﺜﺭﻭﺍﺕ ﻫﺎﺌﻠﺔ ﻓﻲ ﻫﺫﺍ ﺍﻟﻤﺠﺎل ﺇﻻ ﺃﻨﻪ ﻻ ﻴﺯﺍل ﺨﺎﺭﺝ ﻗﺎﺌﻤﺔ ﺍﻷﻭﻟﻭﻴﺎﺕ، ﻤﻤﺎ ﺃﻋﻁﻰ ﻓﺭﺼﺔ ﻟﻌﻭﺍﻤل ﺍﻟﺘﻠﻑ ﺍﻟﻤﺨﺘﻠﻔﺔ ﻭﻤﻥ ﺃﺨﻁﺭﻫﺎ ﺍﻟﺘﻌﺩﻴﺎﺕ ﺍﻟﺤﺎﺼﻠﺔ ﻤﻥ ﻗﺒل ﺍﻟﺒﺸﺭ ﻭﺍﻟﻤﺘﻤﺜﻠﺔ ﻓﻲ ﻤﺎ ﻴﻤﺎﺭﺱ ﻤﻥ ﻋﻤﻠﻴﺎﺕ ﺘﺨﺭﻴﺒﻴﺔ ﺘﺤﺕ ﻤﺴﻤﻰ ﺍﻟﺘﺭﻤﻴﻡ. ﻤﺩﻴﻨﺔ ﻟﺒﺩﺓ ﺍﻟﻜﺒﺭﻯ ﺍﻷﺜﺭﻴﺔ ﺃﺤﺩﻯ ﺃﻫﻡ ﺍﻟﻤﻌﺎﻟﻡ ﺍﻟﻤﻤﻴﺯﺓ ﺍﻟﺘﻲ ﻟﻡ ﻴﺸﻔﻊ ﻟﻬﺎ ﻜﻭﻨﻬﺎ ﺘﺘﺼﺩﺭ ﻗﺎﺌﻤﺔ ﺍﻟﻤﻭﺭﻭﺙ ﺍﻟﻤﻌﻤﺎﺭﻱ ﻓﻲ ﻟﻴﺒﻴﺎ ﺃﻥ ﺘﺴﻠﻡ ﻤﻥ ﺍﻟﺘﻌﺩﻱ ﻋﻠﻰ ﺍﻟﻌﺩﻴﺩ ﻤﻥ ﺼﺭﻭﺤﻬﺎ ﻤﻤﺎ ﺃﺩﻯ ﺇﻟﻰ ﺘﺸﻭﻴﻬﻬﺎ ﻭﻁﻤﺱ ﺠﺯﺀ ﻤﻥ ﻤﻌﺎﻟﻤﻬﺎ .ﻭﻋﻨﺩ ﺍﻟﺘﺤﺩﺙ ﻋﻥ ﺍﻟﻤﻭﺭﻭﺙ ﺍﻟﻤﻌﻤﺎﺭﻱ ﺘﺒﺭﺯ ﻓﻲ ﺍﻷﺫﻫﺎﻥ ﻓﻜﺭﺓ ﺍﻟﺤﻔﺎﻅ ﻋﻠﻴﻪ ﻜﻤﺤﺎﻭﻟﺔ ﻟﻤﻨﺤﻪ ﺍﻻﺴﺘﻤﺭﺍﺭﻴﺔ ﻭﺍﻻﺴﺘﺩﺍﻤﺔ، ﻭﺍﻟﺤﻔﺎﻅ ﻫﻭ ﺍﻟﺘﻠﺨﻴﺹ ﺍﻟﺤﻘﻴﻘﻲ ﻟﻠﻨﺘﻴﺠﺔ ﺍﻟﻤﺭﺠﻭﺓ ﻤﻥ ﻋﻤﻠﻴﺔ ﺍﻟﺘﺭﻤﻴﻡ. ﻴﻬﺩﻑ ﻫﺫﺍ ﺍﻟﺒﺤﺙ ﺇﻟﻰ ﺍﻟﺘﺄﻜﻴﺩ ﻋﻠﻰ ﺃﻫﻤﻴﺔ ﺍﻟﻤﻭﺭﻭﺙ ﺍﻟﻤﻌﻤﺎﺭﻱ ﺍﻷﺜﺭﻱ ﻭﺴﺒل ﺍﻟﺤﻔﺎﻅ ﻋﻠﻴﻪ ﻤﻥ ﺍﻻﻨﺩﺜﺎﺭ ﻭﺍﻟﺘﺸﻭﻴﻪ ﻭﺫﻟﻙ ﻀﻤﻥ ﺃﺴﺱ ﺭﺍﺴﺨﺔ ﻤﺒﻨﻴﺔ ﻋﻠﻰ ﺩﺭﺍﺴﺔ ﻤﺴﺘﻔﻴﻀﺔ ﻟﻠﻤﻭﺍﺜﻴﻕ ﻭﺍﻟﻤﻌﺎﻫﺩﺍﺕ ﺍﻟﺩﻭﻟﻴﺔ ﻓﻲ ﻫﺫﺍ ﺍﻟﻤﺠﺎل ﻭﺘﻘﻴﻴﻡ ﺘﺠﺎﺭﺏ ﺘﺭﻤﻴﻤﻴﺔ ﺴﺎﺒﻘﺔ ﻟﻤﻌﻠﻤﻴﻥ ﻓﻲ ﻤﺩﻴﻨﺔ ﻟﺒﺩﺓ ﺍﻷﺜﺭﻴﺔ ﺘﻤﺕ ﻋﻠﻴﻬﻤﺎ ﻋﻤﻠﻴﺎﺕ ﺘﺭﻤﻴﻤﻴﺔ ﺴﺎﺒﻘﺔ ﻭﻫﻤﺎ "ﻗﻭﺱ ﺍﻟﻨﺼﺭ ﻟﺴﺒﺘﻴﻤﻭﺱ ﺴﻴﻔﻴﺭﻴﻭﺱ ﻭﺍﻟﻤﺴﺭﺡ ﺍﻷﻏﺴﻁﻲ "ﻜﻤﺜﺎل ﺠﻴﺩ ﻭﺁﺨﺭ ﺴﻴﺊ ﻭﺫﻟﻙ ﺒﻨﺎﺀ ﻋﻠﻰ ﻤﺎ ﻭﺭﺩ ﻓﻲ ﺍﻟﺠﺯﺀ ﺍﻟﻨﻅﺭﻱ ﻤﻥ ﺩﺭﺍﺴﺔ ﻟﻠﻤﻭﺍﺜﻴﻕ ﺍﻟﺩﻭﻟﻴﺔ ﻭﻤﻨﻬﺠﻴﺔ ﻭﺇﺴﺘﺭﺍﺘﻴﺠﻴﺔ ﺍﻟﻤﺸﺎﺭﻴﻊ ﺍﻟﺘﺭﻤﻴﻤﻴﺔ ﻓﻲ ﺩﺭﺍﺴﺔ ﻋﻠﻤﻴﺔ، ﻟﻤﻌﺭﻓﺔ ﻤﺩﻱ ﻨﺠﺎﻋﺘﻬﺎ ﻭﺍﻟﻭﻗﻭﻑ ﻋﻠﻰ ﻤﺎ ﺤﺩﺙ ﻓﻴﻬﺎ ﻤﻥ ﺃﺨﻁﺎﺀ ﻭﺘﻌﺩﻴﺎﺕ ﻟﺘﻼﻓﻴﻬﺎ ﻤﺴﺘﻘﺒﻼﹰ، ﺃﻱ ﺃﻥ ﻫﺫﺍ ﺍﻟﺒﺤﺙ ﻴﺘﺒﻨﻰ ﺩﺭﺍﺴﺔ ﺍﻟﺘﺭﻤﻴﻡ ﻜﻤﻨﻬﺞ ﻀﻤﻥ ﺃﺴﺱ ﻭﻗﻭﺍﻋﺩ ﻋﻠﻤﻴﺔ ﻭﻓﻨﻴﺔ ﻤﺤﺩﺩﺓ، ﻭﺍﻟﻐﺭﺽ ﻤﻥ ﻫﺫﻩ ﺍﻟﺩﺭﺍﺴﺔ ﻟﻴﺱ ﺍﻟﺴﺭﺩ ﺍﻟﺘﺎﺭﻴﺨﻲ ﻟﻌﻤﻠﻴﺎﺕ ﺍﻟﺘﺭﻤﻴﻡ، ﺇﻨﻤﺎ ﻫﻲ ﻭﻗﻔﺎﺕ ﻤﻊ ﺃﻫﻡ ﺍﻟﻤﺤﻁﺎﺕ ﺍﻟﺘﺭﻤﻴﻤﻴﺔ ﻓﻲ ﻋﻤﺭ ﺍﻟﻤﺒﻨﻰ ﻭﺩﺭﺍﺴﺘﻬﺎ ﻤﻥ ﺤﻴﺙ ﻤﺩﻯ ﺍﻟﺘﺯﺍﻤﻬﺎ ﺒﺎﻟﻤﺤﺩﺩﺍﺕ ﺍﻟﻔﻨﻴﺔ ﻭﺍﻟﻌﻠﻤﻴﺔ، ﻭﺍﻨﻌﻜﺎﺱ ﺫﻟﻙ ﻋﻠﻰ ﺍﻟﻨﺘﻴﺠﺔ ﺍﻟﻨﻬﺎﺌﻴﺔ ﻟﻠﻌﻤﻠﻴﺔ ﺍﻟﺘﺭﻤﻴﻤﻴﺔ ﻭﺒﺎﻟﺘﺎﻟﻲ ﻋﻠﻰ ﺍﻟﻤﺒﻨﻰ ﺍﻟﻤﺭﻤﻡ، ﺃﻱ ﺃﻥ ﻫﺫﺍ ﺍﻟﺒﺤﺙ ﻻ ﻴﻌﻠﻤﻨﺎ ﻜﻴﻑ ﻴﻜﻭﻥ ﺍﻟﺘﺭﻤﻴﻡ، ﻭﻟﻜﻥ ﺇﻥ ﻜﺎﻥ ﻭﻻﺒﺩ ﻤﻥ ﺍﻟﺘﺭﻤﻴﻡ ﻓﻭﻓﻕ ﺃﻱ ﺸﺭﻭﻁ ﻏﻴﺭ ﻗﺎﺒﻠﺔ ﻟﻠﺘﺤﺎﻴل .ﻭﺘﺨﺘﺘﻡ ﺍﻟﺩﺭﺍﺴﺔ ﺒﺎﻟﻨﺘﺎﺌﺞ ﺍﻟﺘﻲ ﺘﺅﻜﺩ ﻋﻠﻰ ﻨﺠﺎﻋﺔ ﺍﻟﻌﻤﻠﻴﺎﺕ ﺍﻟﺘﺭﻤﻴﻤﻴﺔ ﺍﻟﺘﻲ ﺘﻤﺕ ﻭﻓﻘﺎﹰ ﻟﻠﻤﻨﻬﺞ ﺍﻟﺼﺤﻴﺢ ﺍﻟﻤﺴﺘﻨﺩ ﻋﻠﻰ ﺍﻟﺸﺭﻭﻁ ﺍﻟﻔﻨﻴﺔ ﻭﺍﻟﻘﺎﻨﻭﻨﻴﺔ ﺍﻟﺘﻲ ﻭﺭﺩﺕ ﺒﺎﻟﻤﻭﺍﺜﻴﻕ ﺍﻟﺩﻭﻟﻴﺔ ﻟﻠﺤﻔﺎﻅ ﻭﺍﻟﻔﺸل ﺍﻟﺫﺭﻴﻊ ﻟﻠﻌﻤﻠﻴﺎﺕ ﺍﻟﺘﻲ ﺘﻤﺕ ﺒﺸﻜل ﻏﻴﺭ ﻋﻠﻤﻲ ﻭﻻ ﻤﺩﺭﻭﺱ ﻭﺒﺎﻟﺘﺎﻟﻲ ﺘﺤﻭل ﺍﻟﻤﺒﺎﻨﻲ ﺍﻟﺘﻲ ﺘﻤﺕ ﻋﻠﻴﻬﺎ ﺇﻟﻰ ﻤﺴﻭﺨﺎﹰ ﻓﺎﻗﺩﺓ ﻟﻁﺎﺒﻌﻬﺎ ﺍﻟﻤﻌﻤﺎﺭﻱ ﺍﻷﺼﻠﻲ، ﺒﺎﻟﺘﺄﻜﻴﺩ ﻋﻠﻰ ﻓﺭﻀﻴﺔ ﺍﻟﺩﺭﺍﺴﺔ ﻭﺍﻹﺠﺎﺒﺔ ﻋﻠﻰ ﺘﺴﺎﺅﻻﺘﻬﺎ ﻭﻴﺨﺘﺘﻡ ﺒﺎﻟﺘﻭﺼﻴﺎﺕ
ﺤﺴﻴﻥ ﻋﻠﻲ ﺍﻟﺩﺭﺍﻭﻱ (2013)

من المعروف أن نشاطي الشراء والتخزين ركنان اساسيان من اركان عمليات المؤسسات التجارية أو الصناعية أو الخدمية، وذلك نظراً لضخامة المواد المطلوبة في صناعة وتجارة اليوم. لذا أصبح من الضروري الاهتمام الكافي بهذان النشاطان، ولهذا السبب كانت فكرة هذه الدراسة. في هذه البحث تم تغطية الإطار النظري بمواضيع تشمل إدارة المشتريات وإدارة المخازن، يلي ذلك الإطار التطبيقي المتمثل في الدراسة الميدانية بجمع المعلومات من ثلاث مؤسسات ليبية كبيرة متنوعة المجالات، كعينة على المؤسسات الليبية، وهذه المؤسسات هي الشركة العامة للكهرباء، وشركة مليته للنفط والغاز، والشركة العامة للنقل البحري. كذلك تم إجراء دراسة إستبيانية بتوزيع استبيان لإدارة المشتريات وآخر لإدارة المخازن على عينة عشوائية لكل من هذه المؤسسات. ومن خلال النتائج المتحصل عليها من هذه الدراسة (البحث)، توصلت الباحثة لعدة استنتاجات عن اداء ادارتي المشتريات والمخازن في المؤسسات الليبية، ومن هذه الاستنتاجات انبثقت مجموعة من التوصيات التي تعتقد بان إتباعها قد يساهم في انجاح اداء ادارتي المشتريات والمخازن، وبالتالي انجاح ادارة حركة المواد في المؤسسات الليبية. ومن خلال هذه الدراسة، تم التوصل الى تصميم نموذج قدمته كمقترح لإدارتي المشتريات والمخازن، والتي تشمل طريقة الشراء والتخزين والفحص والصرف، وتم كذلك اقتراح نموذج لهيكل تنظيمي يتبع الاسلوب العلمي المطور لإدارتي المشتريات والمخازن.وترى الباحثة في هذا المقترح، ضرورة جمع إدارة المشتريات وإدارة المخازن في إدارة واحدة، يرأسها مدير واحد يتبع مدير الشؤون التجارية والمالية، يطلق عليها إدارة المواد. وينتج من دمج المشتريات والمخازن، ومراقبة المخزون في إدارة واحدة، مجموعة من المزايا غير متواجدة في النماذج الموجودة في المؤسسات الليبية تحت الدراسة. ونتيجة لان نشاطي الشراء والتخزين يعتبران نشاطان خدميان مهما اختلف تخصص المؤسسة التابعان لها، سواء كانت هذه المؤسسة إنتاجية صناعية أو تجارية أو خدمية، فان هذا المقترح من الممكن استخدامه في مختلف المؤسسات الليبية.وباعتقاد الباحثة بان هذا المقترح المقدم سيساعد في مراقبة حركة المواد، لأنه يربط المخازن بالمشتريات في مستنديه واحدة، ومن خلاله لا يتم الشراء إلا بعد التأكد من عدم وجود المواد بالمخازن، وبالتالي يمنع تكدس المواد وازدواجية الطلبيات. ايضا فإن هذا المقترح يجعل عملية الدفع مؤجلة حتى وصول المواد للمخازن وفحصها فنياً، وعند التأكد من سلامتها ومطابقتها للمواصفات، عندها فقط يتم الدفع وهذا يمنع تكدس المواد الغير مطابقة للمواصفات في المخازن ويحد من خسائر الشركة.

Abstract

It is well known that the purchase and storage activities are considered to be the fundamental pillars of the business, commercial, industrial or service operations, due to the magnitude of the required materials in the manufacture and trade of the day. So it became necessary to give adequate attention to these activities, and that’s why the researcher had thought of the idea of this research.In this research, the theoretical framework covering topics include procurement (purchasing) management and warehouse (inventory and storage) management; followed by a practical framework of the field study to collect information from the work of three large Libyan institutions in a variety of fields, namely, the General Electric Company, Mellitah Oil and Gas Company, and the General Company for Maritime Transport, as a sample of the Libyan institutions. Also, the study includes the distribution of questionnaires to procurement management and warehouses management on a random sample of each of these institutions.Through the obtained results from this study (research), the researcher reached several conclusions about the performance of the management of procurement and warehouses in the Libyan institutions and these conclusions emerged a set of recommendations. It is believed that if these recommendations were followed, then they may contribute to the success of the performance of the management of procurement and warehouses, and consequently to the success of the management of movement of materials in the Libyan institutions.An important model design presented as a proposal for the management of procurement and warehouses has been reached, which include a method for purchases, storages, inspection, and payment. Also an organization structure model was proposed that follows the advanced scientific method to manage the procurement and warehouse. Since the purchases and the warehouses are considered two service activities; then no matter what type of activity the institution is following; whether it is an industrial productivity, commercial or service, this proposal could be implemented in various Libyan institutions.The researcher beliefs that this proposed model will help in monitoring the movement of materials, it connects warehouses with purchases in just one documentary, and through it, purchase is only allowed after making sure that there are no materials in the warehouses, and thus prevents the accumulation of materials and duplication orders. Also, this proposal makes payment deferred until the arrival of materials to warehouses and technically inspected; when you confirm the safety and compliance with the specifications, only then the payment is made, and this prevents the accumulation of non-matching material to the specifications in the warehouses and reduces the company's losses.
سيناء يوسف السويحلي (2014)

نتقدم بهذه الدراسة، التي تعالج مشكلة من أهم المشكلات الهندسية حيث أن الأساسات على القواعد المرنة تشكل مشكلة تقنية شائعة في مجال الهندسة المدنية وقد تم أقتراح العديد من الحلول لها في السنوات الأخيرة لقد بقى أعتبار مرونة التربة تحت الأساسات مهملاً لفترة طويلة، وذلك نظراً لصعوبة الحل الرياضي من جهة، بالإضافة إلى عدم وجود نظريات ثابتة ومحققة دوماً، وما ذلك الا بسبب عدم وجود خواص ثابتة لتربة القواعد، موضوع البحث ومع تقدم العلوم والهندسية منها بشكل خاص، ونتيجة للإبحاث والتجارب التي لاحصر لها، والتي أستند إليها العديد من الفرضيات والنظريات المتتابعة، وبفضل الوسائل التعليمية، التي مكنت من حل أعقد المسائل الرياضية، فقد تمكن التوصل إلى بعض الحلول المقبولة من الناحية النظرية، إلى جانب أنها أعطت نتائج عملية جيدة، كما سنرى في الدراسات والحلول المقدمة ضمن هذه الدراسة وبالنظر لأهمية الأساسات وخطورتها بالنسبة لكافة المنشآت الهندسية، فإننا نأمل أن يلقى الموضوع كل ما يستحقه من اهتمام ومتابعة.
زينب عمر القضقاض (2006)

Abstract

1. The experimental viscosities densities measured with Anton Paar SVM 3000 equipment, and refractive indices measured with Refractive Meter equipment, corresponding values of excess molar volumes (VE ), deviations in viscosity (Δμ), deviations in refractive index (ΔnD), excess Gibbs energy (GE), and excess molar enthalpy (HE), for binary, ternary and fourth mixtures of alcohol, ether, and n-alkanes. 2.Used for the calibration experimental from paper [7] were the mixture for the binary system (tert butyl alcohol + ethanol ), we had good result and ADD% for densities, viscosities and refractive indices were 0.1657 %, 0.4846 %, and 0.033545 % respectively. 3.Data of binary mixture were fitted to a Redlich-Kister's The choice of the proper number of coefficients (p), was based on the standard deviations, and the F-test as criterion of goodness with an error lower that 1% see. 4.Data of ternary and fourth mixture were correlated by Cibulka equation were determined with the optimization algorithm similar to that for the binary parameters the σ values was less than 0.05%. 5.The experimental viscosities densities and refractive indices were positive and decrease with increase temperature for all tables for binary ternary and fourth mixtures. 6.Excess molar volumes (VE), was negative value for all binary system, Deviations in viscosity (∆µ), negative value, but at system (n-hexane + n-heptane), maximum positive and minimum with negative value, Deviations in Refractive Index (ΔnD), was were positive for all binary mixtures, Excess Gibbs Energy was negative for all binary ,but maximum positive and minimum with negative value just at system (n-hexane + n-heptane). 7.Excess properties for ternary mixture negative and positive value. 8.Excess properties for fourth mixture negative value.
سهير المبروك دربال (2009)

Abstract

Abu-Shaybah Formation is located on the coastal of the Meditrranean sea South of Ghanimah North West of Libya, between Tripoli and Al Khumes, about 100 km East of Tripoli. It lies on the eastern end of Jabel Nafusa flank. Abu Shaybah Formation Ghanimah area of Late Triasic age, consists of sandstone. The sedimentary structure in the lower most part from studied outcrops reflect NW paleocurrent direction indicating that Jabel Nafusa uplift poorly effect the study area. The upper part of studied succession changing in pallaeocurrent dirction to NE due to Jabel Nafusa uplifting. The extreme changing of paleocurrent direction and paleoslope direction to East due to continuous increase in Jabel Nafusa uplift, direction of vertical joints in Wadi Qirrim presented from NW to SE dirction. The rocks of Abu Shaybah Formation analyzed using differnt kinds of technique, Polrized Microscpe, XRF, SEM techniques. The study of sedimentary texture (grain size, roundness, sorting, and sphiricity) and sedimentary structures showed that Abu Shaybah Formation outcrops deposited in response to two fining upword cycles, formed mainly in Braided Stream Rivers with some effects of meandering. The sequences of Abu Shaybah Formation outcrops that exposed in Wadi Qirrim have been identified on many types of sedimentary facies associated with given sedimentary stucture as, Planar cross bedding, Convolute bedding, Trouph cross bedding, Ripple bedding, Shrinkage cracks, Plant rootlets, Concretions, Unconformity, Channels, Massive bedding, Laminated bedding, and the results which located on the grain size of quartz also loacted on the grain size of heavy minerals like tormaline, zircon and reutile.
سليم معمر قجوم (2009)

Abstract

Ad-hoc networking is a concept in computer communications, which means that users wanting to communicate with each other form a temporary network, without any form of centralized administration. Each node participating in the network acts both as host and a router and must therefore be willing to forward packets for other nodes.In a multi-hop wireless packet network, a packet traverses more than one wireless link in traveling from its source to its destination. Such wireless networks have received considerable attention recently in the context of ad hoc networks. Ad-Hoc networks are self-organizing multi-hop wireless networks where not all links along the path of a packet can be activated simultaneously. Hence the performance of a higher level mechanism, such as congestion window or Transport Layer protocol (TCP) will depend crucially on how the links are scheduled for transmission. In multiple access networks, such as the IEEE802.11 wireless LAN, the scheduling of transmissions is done by the medium access control (MAC) protocol. This transmission scheduling is completely unaware of the needs of the TCP congestion window protocol. This thesis is concerned with the poor interaction between the TCP adaptive window protocol, the IEEE 802.11 MAC protocol, and the IEEE 802.11 Ad-Hoc routing protocol. Our thesis follow on the work done by the researchers K. Nahm and C. Kuo in the paper entitled “TCP over 802.11 Multihop networks issues and Performance Enhancement” [1]. Our contributions are two-fold. First we have repeated and confirmed the simulation results reported by K.Nahm and C.Kuo using NS-2 network simulator. Second we have introduced a simple modification in the 802.11 DSR routing protocol which reduces the unnecessary VI reroutings triggered by MAC packet collisions and enforces the TCP to enter the fast retransmit / fast recovery phase to quickly recover the packet loses. This modification has been simulated using NS-2 network simulator and from the results we have found that it provides a substantial improvement in TCP performance in the situations that we have considered in the simulation models
يحي الشارف المبروك (2009)

Abstract

Against the background due to the energy crisis in the late 1970’s, the pinch analysis has emerged as a powerful tool for the integrated design of process heat networks which include heat exchangers, distillation columns, furnaces, etc..The key strategy of this methodology is to set energy targets prior to design based on basic thermodynamic principles.The subject of this thesis in to apply this analysis to one of the Libyan Refineries, namely Ras Lanuf Refinery, to assess energy utilization of such big energy – consuming plants and to explore the potential of energy as well as capital costs savings based on the finding of applying this analysis. Based on actual operating data collected from the plant and application of the procedure of the pinch analysis to this real case study where a minimum temperature difference approach in the Ras Lanuf refinery heat exchangers design of 10 (ΔT min =10 ) the following results were obtained. Actual rate of energy consumption of the base case design of the refinery is 9MW which is provided by burning fuel oil in the furnace, while the minimum target predicted by the pinch analysis should be 8MW. This amounts to just over 11% energy savings which equivalent to $462,000 per year reduction in the operating cost of the refinery
هويدة الهادي الحبيشي (2011)

Abstract

Cement kiln dust is a major by product in cement manufacture. Methods of disposal, handling, treatment and reuses are a major factors in optimization of a certain cement plant. This thesis concentrates on the uses of cement kiln dust of souk Al Kamees cement plant as Soil amendment and as an adsorpent of Fe, Zn and lead results from sand. The major objectives of these treatments are environmental rather than economical to reduce the landfill disposal of CKD which is major problem in cement industry. CKD is used in agricultural soil amendment.CKD in Souk Alkamees consists primarily of calcium carbonate and silence dioxide, the alkaline by pass process contains highest amount of calcium oxide and lowest loss on ignation [LOI] which become a beneficial for CKD use as a soil amendment to the sand for many especial agricultural products such as potatoes, …etc. This thesis concentrates on the uses of CKD as an adsorbent to remove heavy metals such as Fe, Zn, and Pb from soil. Adsorption column is used to perform the work. Experimental setup discussed in the thesis is used using cement kiln dust as an adsorbent for removal of heavy metals from soil. The major result is to simulate the physical behavior of the process using conventional isotherms available in literature, Langmuir, Freandlish and Drachsal isotherm models have been found to simulate the data with good agreement with experimental work. Characterization of the CKD is made after dehydration process at 150C for 24 hrs. X ray fluorescent equipment is used and the results are reported in the thesis.
محمد محمود الشاهري (2015)