Abstract The objective of this study is to formulate a drilling cost model which incorporates the drilling parameters, encountered during drilling operation of the petroleum well. This model is coupled with the selected drilling rate model proposed by Bourgoyne & Young, in order to predict the bit rotating time utilized in this model. The new drilling cost model was formulated using actual drilling data collected from thirteen wells selected in three oil fields in Sirte Basin (Ghani, Zenad, and Ed Dib).The drilling engineer can use drilling correlations in the planning stages of a well to help evaluate various drilling parameters encountered during drilling operations in order to update the proposal drilling plan and to evaluate any deviations from original projections. The gathered information will help selecting the best completion strategies as well as gaining experiences in the drilled area which will be the basis for the planning of future drilling activities in the area.
عزالدين أحمد أحمد (2009)

تأثير ألضوضاء على السلوكيات البشرية تتدرج من البسيطة والتي يمكن إهمالها إلى الإزعاج, الغضب, والإحباط النفسي.أما التأثير العضوي ,الضوضاء يمكن أن تتراوح من غير المؤذية إلى المؤلمة,وتسبب أضرارا جسدية. ضوضاء الطائرات تتجاوز عدم القدرة على النوم المريح وإحداث الضرر بطبلة الإذن. وقد تسبب في ارتفاع ضغط الدم وضربات القلب وأمراض الكلي والخرف. الناس الذين يعيشون في تجمعات سكنية قرب المطارات أصبحوا قلقين على نحو متزايد بشأن المشاكل الصحية المحتملة بسبب ضوضاء الطائرات. وبوجه عام فان تخفيض الضوضاء الناتجة عن محركات الطائرات التجارية وبسبب تزايد حركة الملاحة الجوية,يعتبر تحد مستمر .لذلك فان معظم شركات صناعة محركات الطائرات قامت بإعداد مجموعة برامج تهدف إلى تخفيض الضوضاء.حيث أنه بذلت بعض الجهود من قبل الشركات المصنعة للمحركات لتخفيض الضوضاء بحدود 15 ديسيبل أي بنسبة (10%) وفي الحقيقة فان الأجيال التالية للمحركات هي من نوع high-bypass ratio (نسبة الهواء الجانبي اكبر من الهواء عبر حجرة الاحتراق).مقاييس ضوضاء الطائرات , وتردداتها أخذت في العديد من المواقع حول مطار طرابلس العالمي , وتم تحليل البيانات المكتسبة .التحليلات أوضحت أن ترددات موجات الصوت الناتجة عن الطائرات هي من النوع المنخفض الاقل من( 400 هيرتز) وهذا النوع من الترددات يخترق البنايات, وقد وجدت العديد من الشقوق في البنايات القريبة من المطار. كما تبين أن أعلى معدل للشكاوى بشأن الاضطراب أثناء النوم والإزعاج يأتي من الناس الذين يعيشون حول المطار. وقد وجدت علاقة خطية بين التعرضِ المزمن لضوضاءِ الطائرات و ضعف القراءة والفهمِ والذاكرة. Abstract The effect of noise on human emotion ranges from negligible, through annoyance and anger, to psychological disruptive, physiologically, noise can range from harmless to painful and physically damaging, aircraft noise goes beyond disturbed sleeps and damaged eardrums. It may also cause hypertension, strokes, kidney diseases and dementia.People who live in communities near airports have become increasingly concerned about potential health effects from aircraft noise. In general the reduction of noise of the commercial aircraft engines is a continuing challenge, and due to the rise of air-traffic movements, major aero-engines manufacture set programs that aim to reduce the noise.There are some efforts made by engine manufacturers to reduce the noise. It results in a reduction to about ~15dB (10%). In fact the later versions of engines are of high-bypass ratio type to reduce the noise Aircraft noise measurements, have been taken at many sites around Tripoli International Airport, and their frequencies, and analyzing the obtained data. The analyzing shows that aircrafts noise frequencies are low-frequencies less than (400Hz) which penetrate the buildings, cracks have been found in the buildings near the airport. The highest numbers of complaints of sleep disturbance and annoyance come from people living around airports. Linear exposure-effect associations were found between chronic aircraft noise exposure and impairment of reading comprehension and recognition memory.
ميلاد عمر المزوغي (2009)

Abstract Wind turbines are the means of converting wind energy into electrical energy. It is not unexpected that certain brands of horizontal wind turbines are optimally designed for certain wind speed regimes prevailing at certain sites. It has been the objective of this study to find out whether it is possible to design a wind turbine that is more suitable for a site of lower annual mean wind speed such as the western coast of Libya. In achieving this objective, use was made of a typical wind turbine aerodynamic design and performance analysis procedure together with actual wind speed data recorded at the city of Misurata.Based on the annual wind energy yield obtained from different designs of wind turbines having different rated wind speeds and different blade design tip speed ratios, this study indicates that the decrease of the rated wind speed leads to a continuous increase of annual energy yield as well as an increase of the cost of the wind turbine. Therefore the optimum value of rated wind speed for this site may only be determined as a compromise between added wind energy yield and added cost. Moreover, for any given rated wind speed this study indicates that a blade design tip speed ratio equal to six seems to be the optimum value for the given site.
محمد على نايلي (2015)