The Application of Heat Transfer Analysis in Condition Monitoring System of Wind Generators
Conference paperEffective cooling is required in power generation, processing, and distribution to avoid failure that could occur during operations. As heat loads continue to increase, manufacturers of wind turbines are turning to improve the cooling system to remove high intensity heat loads from many active parts particularly in the generator part. Wind generators need an effective cooling system due to the large amount of heat that is released during power production. Many large wind turbines (more than 5MW rated power) particularly offshore wind turbines where the water is available, heat exchangers with water-air cooling system is used, in which the water is utilized to cool the hot air. This type of heat exchangers are desired, since they are more efficient and reliable than the air-air heat exchangers, which are used in small wind turbines. Because of the growing number of failures that occurred in wind turbine generators due to high generator’s temperatures owing to power losses of generator, applying condition monitoring system on wind generators depending on heat transfer analysis through the heat exchangers of wind generators plays an effective role. This helps avoid failures and maintain wind turbines to be protected. In this paper new methodology has been applied by considering the heat transfer and fluid mechanics analysis through a heat exchanger of wind generator, which uses water to air cooling system. Case study based on data collected from actual measurements demonstrates the adequacy of the proposed model.
KHALED BUBAKER MATOG ABDUSAMAD, (12-2013), Hong Kong, China: IEEE, 1-7
[PDF] from academia.edu The Influence of Project Characteristics on Green Design Performance of Building Projects
Journal ArticleThe building projects are differentiated, each building project is unique in terms of size, the level of complexity, procurement systems required. The characteristics of building projects could have major influence on overall project performance. Building projects that incorporate green designs, which are complicated to understand or manage adequately and are more complex compared with typical building projects. Therefore, To achieve high-green design performance, understand crucial characteristics of building projects that may have affect performance level of green design is required. The propose of this study to identify key project characteristics of building projects influencing green design performance. To achieve mentioned aim a questionnaire survey was conducted to collect dada required. A sample of 274 respondents has been covered under the study, including architects and engineers practicing design and consultancy building sectors. Prior to analysis of data WINSTEPS software were used to determine validity and reliability of date. Descriptive analysis data includes quantitative and qualitative. The results revealed that the Project Size can influence the Green Design Performance. The type of Building and size of the project are the key factors influencing Green Design Performance. The Availability of Design Information was moderate. The Reused and Recycled Materials were hard to find, while Regional Materials were available in the market.
Mohamed S Abd Elforgani, (12-2013), International Journal of Engineering Research & Technology (IJERT): IJERTV2IS120239, 2 (12), 1-11
التعلم النشط واستقراء قاعدة المعرفه
مقال في مؤتمر علميتعرض هذه الورقه طرقا لتعزيز دقة انظمة التعلم الاستقرائي، وتهتم بمسائل: تعلُم قواعد الأثر production rules في مهام تصنيف متعددة الفئه multi-class classification tasks في مجالات مشوّشه ، والإبقاء على تعلم مستمر عند مصادفة وضع جديد عقب انتهاء مرحلة التعلم الأولى، وتصنيف كائن ما object عندما لا يوجد قانون ينطبق على ذلك الكائن.
لقد اوضحنا ان دمج نسق تقييم الأداء والتعلم يعمل على تقديم تصنيفات دقيقه لفئات بيانات واقعيه. وتعرض الورقه النظام أريس ARIS الذي يحقق هذا الاسلوب، وقد تبين ان التصنيفات الناتجه هي غالبا أدق من تلك التي توفرت عن طريق قواعد المعرفه غير المنقحه.
يعتمد قرار التصميم الرئيسي في نظام اريس على ترتيب القوانين Rules طبقا لأوزانها، ويتم تعلم وزن القانون باستخدام نظرية باييز لحساب اوزان شروط القانون ودمجها، ويركز هذا النموذج على تحليل قاعدة المعرفه ويساند عملية التنقيح بكفاءة.
ان هذا النظام (أي اريسARIS) ليس تفاعليا، ويعتمد على كاشفات heuristics لتركيز عملية التنقيح على تلك التجارب التي تبدو اكثر تناغما مع فئة بيانات التنقيح. ويتكون الاطار التصميمي لنظام ARIS من نموذج جدولي لتمثيل اوزان القانون والعلاقه بين حالات التنقيح والقوانين التي تفي (او تنطبق على) كل حاله لتركيز عملية التنقيح، وقد استخدم النظام لتنقيح قواعد معرفه صنعها ARIS بنفسه، وكذلك تنقيح قواعد معرفه اختلقها نظام RIPPER ونظام C4.5 في عشرة ميادين تم اختياها.
محمد ابوالقاسم علي الرتيمي، (10-2013)، المغرب: المؤسسة العربية للعلوم والتكنولوجيا، 1-10
Modeling of beam-to-column joints of steel concrete composite frames subjected to standard and extreme load combinations
PhD ThesisProgressive building collapse occurs when failure of a structural component leads to the failure and collapse of surrounding members, possibly promoting additional collapse. Global system collapse will occur if the damaged system is unable to reach a new static equilibrium configuration. The objective of this research is to identify and investigate the importance of issues related to the unexpected collapse resulting from the loss of key elements of the structure (a column or columns, for example). In this research study there are examined on the entire frame including details of the column loss scenario and also the influence of the ductility and strength of beam-to-column joints adjacent to the location of such as incident. The study also includes catenary action in beams resulting from collapse and its impact on the adjacent joints and reports on the comparison of negative and positive moments in joints. In addition, it records the important notes associated with the state of collapse and parts of this research include the conformity of numerical and analytical results, the ratio of credibility and conformity of results and the test. This thesis reports in detail on the experimental and numerical investigations of the behaviour of steel and composite joints, which aim to develop common solutions with regard to the joint semi-rigid and partial strength properties that might allow for significant rotations and the redistribution of internal forces in structural system when there was a damage to its key element such as a column. Investigations of steel and composite joints with regard to their ductile behaviour are presented. Thereby special attention is paid to shaping of …
Bashir Ali Kalifa Saleh, (10-2013), Warsaw University of Technology: Bashir SALEH,
A condition monitoring system for wind turbine generator temperature by applying multiple linear regression model
Conference paperThe development and implementation of condition monitoring system become very important for wind industry with the increasing number of failures in wind turbine generators due to over temperature especially in offshore wind turbines where higher maintenance costs than onshore wind farms have to be paid due to their farthest locations. Monitoring the wind generators temperatures is significant and plays a remarkable role in an effective condition monitoring system. Moreover, they can be easily measured and recorded automatically by the Supervisory Control and Data Acquisition (SCADA) which gives more clarification about their behavior trend. An unexpected increase in component temperature may indicate overload, poor lubrication, or possibly ineffective passive or active cooling. Many techniques are used to reliably predict generator's temperatures to avoid occurrence of failures in wind turbine generators. Multiple Linear Regression Model (MLRM) is a model that can be used to construct the normal operating model for the wind turbine generator temperature and then at each time step the model is used to predict the generator temperature by measuring the correlation between the observed values and the predicted values of criterion variables. Then standard errors of the estimate can be found. The standard error of the estimate indicates how close the actual observations fall to the predicted values on the regression line. In this paper, a new condition-monitoring method based on applying Multiple Linear Regression Model for a wind turbine generator is proposed. The technique is used to construct the normal behavior model of an electrical generator temperatures based on the historical generator temperatures data. Case study built on a data collected from actual measurements demonstrates the adequacy of the proposed model.
KHALED BUBAKER MATOG ABDUSAMAD, (09-2013), Manhattan, KS, USA: IEEE, 1-8
Flexible Pavement Rutting Prediction Model for Wet Freeze Zone
Conference paperPavement distress is an indication of pavement layer deterioration. There are many types of
deteriorations; however, rutting, defined as the permanent deformation forming longitudinal
surface depressions in the wheel paths, is one of the most important kind of distress that affect
the safety and the ride quality of flexible pavement. The main objective of this study was to
develop an empirical pavement rutting model for the wet freeze zone, which is one of the four
long term pavement performance (LTPP) climate zones, to predict the depth of pavement rutting
on granular bases. Using the LTPP database, the study aimed at a better understanding of the
pavement rutting phenomena and the factors that may affect pavement rutting. Multiple
regression analysis was performed to develop a flexible pavement rutting model. The proposed
model was developed based on the relationship between the response variable rut depth, and
predictor variables of traffic loads, structural number, Marshall stiffness, air voids in the total
mix, and voids in the mineral aggregate. It was found that traffic loads was the predominant
factor that have a significant effect on pavement rutting, which agrees with the existing
literature, as well as engineering knowledge and practice. Following the traffic loads, structural
number was the most significant secondary factor, followed by percent of voids in the total mix,
- voids in the mineral aggregate, and Marshall stiffness.
Asmaiel Kodan Ali Naiel, (07-2013), Honolulu, USA: ISEC, 1-7
The Effects of Adding External Mass and Localised Fatigue upon Static and Dynamic Balance
Conference paperThe influence of physical (external added weight) and neurophysiological (fatigue) factors on static and dynamic balance in sport related activities was typified statically by the Romberg test (one foot flat, eyes open) and dynamically by jumping and hopping in both horizontal and vertical directions. Twenty healthy males were participated in this study. In Static condition, added weight increased body-s inertia and therefore decreased body sway in AP direction though not significantly. Dynamically, added weight significantly increased body sway in both ML and AP directions, indicating instability, and the use of the counter rotating segments mechanism to maintain balance was demonstrated. Fatigue on the other hand significantly increased body sway during static balance as a neurophysiological adaptation primarily to the inverted pendulum mechanism. Dynamically, fatigue significantly increased body sway in both ML and AP directions again indicating instability but with a greater use of counter rotating segments mechanism. Differential adaptations for each of the two balance mechanisms (inverted pendulum and counter rotating segments) were found between one foot flat and two feet flat dynamic conditions, as participants relied more heavily on the first in the one foot flat conditions and relied more on the second in the two feet flat conditions.
khaled Gabriel Mustafa abuzayan, (05-2013), Lucerne, switzerland: https://scholarly.org/, 191-203
Changes in Subjective and Objective Measures of Performance in Ramadan
Journal ArticleThe Muslim faith requires individuals to fast between the hours of sunrise and sunset during the month of Ramadan. Our recent work has concentrated on some of the changes that take place during the daytime when fasting. A questionnaire was developed to assess subjective estimates of physical, mental and social activities, and fatigue. Four days were studied: in the weeks before and after Ramadan (control days) and during the first and last weeks of Ramadan (experimental days). On each of these four days, this questionnaire was given several times during the daytime and once after the fast had been broken and just before individuals retired at night. During Ramadan, daytime mental, physical and social activities all decreased below control values but then increased to abovecontrol values in the evening. The desires to perform physical and mental activities showed very similar patterns. That is, individuals tried to conserve energy during the daytime in preparation for the evenings when they ate and drank, often with friends. During Ramadan also, individuals were more fatigued in the daytime and napped more often than on control days. This extra fatigue probably reflected decreased sleep, individuals often having risen earlier (before sunrise, to prepare for fasting) and retired later (to enable recovery from the fast). Some physiological measures and objective measures of performance (including the response to a bout of exercise) have also been investigated. Urine osmolality fell during the daytime on control days as subjects drank, but rose in Ramadan to reach values at sunset indicative of dehydration. Exercise performance was also compromised, particularly late in the afternoon when the fast had lasted several hours. Self-chosen exercise work-rates fell and a set amount of exercise felt more arduous. There were also changes in heart rate and lactate accumulation in the blood, indicative of greater cardiovascular and metabolic stress caused by the exercise in subjects who had been fasting. Daytime fasting in Ramadan produces widespread effects which probably reflect combined effects of sleep loss and restrictions to intakes of water and food.
khaled Gabriel Mustafa abuzayan, (05-2013), Lucerne, switzerland: https://scholarly.org/, 7 (5), 1095-1104
النشر الإلكتروني: دراسة تحليليه
تقرير علميالهدف لأي نظام معلوماتي هو استغلال المعلومات واستثمارها للرفع من مستويات التعليم وتشجيع المساهمة في اتخاذ القرار لتقدم البشريه. وتبث المعلومات المنتجه بواسطة العديد من وسائط النشر المتاحة ، وتتعاظم اهمية النشر الالكتروني كلما اتسعت الشبكة المعلوماتيه( الانترنت) internet ، فحجم المعلومات المتوفر بها مذهل ويزداد ميتخدموها بالآلاف كل يوم. كما تعمل التقنيات لحديثه على إحداث تحولات جوهريه في عملية نشر و توزيع المعلومات وهي تشكل اساسا لمجتمع المعلومات الجديد.
تحاول هذه الورقه دراسة تأثير النشر الالكتروني والشبكة المعلوماتيهعلى الكتاب الورقي والمكتبات والدوريات العلميه .
محمد ابوالقاسم علي الرتيمي، (04-2013)، طرابلس: الأكاديمية الليبية،
Optimization of hydrodesulfurization activity in the hydrotreating process: canonical analysis and the combined application of factorial design and response surface methodology
Journal ArticleThis study is aimed at investigating the interactive effects of reaction parameters such as temperature (330–370 °C), total pressure (30–50 bar) and liquid hourly space velocity LHSV (1–3 h−1) on the performance of hydrodesulfurization (HDS) activity. Experiments were performed based on the central composite rotatable design and analyzed using the response surface methodology (RSM). First, the equation model is used to predict HDS activity as a response. Second, the regression analysis of the HDS activity model is obtained from the output of this developed model. Finally, the RSM and canonical analysis is used to optimize this empirical regression model. R 2 = 96.5 % showed that the RSM model fitted the observed data well with and is considered to be accurate and available for predicting HDS activity. The obtained equation for the canonical analysis with different signs of eigenvalues …
Fawzi Mohamed Amin Mohamed Elfagaih, (04-2013), Reaction Kinetics, Mechanisms and Catalysis: Springer Netherlands, 108 (1), 371-390