Analytical Comparison of Helicopter and Airplane in Level Flight

10.2514/8.699 ◽  
1938 ◽  
Vol 5 (11) ◽  
pp. 431-435 ◽  
Author(s):  
MONTGOMERY KNIGHT
Keyword(s):  
Analytical Comparison ◽  
Level Flight

الشيخ والشاه مقارنة أوليَّة في الإرث الفكري لمحمد بن عبد الوهاب وولي الله الدِّهلوي The Sheikh and Shah Preliminary Comparison of the Intellectual Legacy of Muhammad ibn ‘Abd Al-WahhÉb and WalÊ Allah DehlawÊ

2016 ◽  
Vol 13 (1) ◽  
pp. 1-25
Author(s):  
حسن أحمد إبراهيم
Keyword(s):  
Arabian Peninsula ◽  
Muslim World ◽  
Islamic Revival ◽  
Analytical Comparison ◽  
Islamic Reform ◽  
Preliminary Comparison ◽  
Intellectual Heritage ◽  
Intellectual Legacy

         الملخّصتحاول هذه الدراسة، التي أحسب أنها الأولى من نوعها، أن تقدم مقارنة تحليلية للإرث الفكري للشيخين محمد عبد الوهاب (1703-1791م) في الجزيرة العربية وشاه ولي الله الدهلوي (1703-1761م) في شبه القارة الهندية في إطار واقعهما البيئي. وتخلص إلى أن لفظ "الوهابية الهندية"، الذي ابتدعه بعض المستشرقين لوصف حركة الإصلاح الإسلامي في الهند، والذي يوحي بأن رائدها الدِّهلوي كان مجرد نسخة مطابقة لمعاصره ابن عبد الوهاب، مصطلح غير دقيق، بل لعله خاطئ كليًّا. وذلك لأن دراسة الإرث الفكري لهذين العملاقين تبين بأنهما أسسا في عصر ما قبل الهجمة الإستعمارية على بلاد المسلمين مدرستين متباينتين من حيث التوجه والمحتوى.الكلمات المفتاحية: محمد عبد الوهاب، شاه ولي الله، الإرث الفكري، التجديد الإسلامي. Abstract          This is the first study to provide an analytical comparison of the intellectual legacy of two great scholars Muhammad ibn ‘Abd al-WahhÉb (1703-1791) in the Arabian Peninsula and Shah WalÊ Allah DehlawÊ (1703-1761) in the Indian sub-continent in the context of their respective environments. It concludes that the term “Indian Wahhabism”, which was coined by some Orientalists to describe the movement for Islamic reform in India, suggesting that Sheikh DehlawÊ was just a duplicate of contemporary Ibn ‘Abd al-WahhÉb, is not only inaccurate but completely incorrect. The study of the intellectual legacy of these two luminaries reveals that they both founded, prior to the pre-colonial attack on the Muslim world, two schools different in terms of orientation and content..Keywords: Muhammad ibn ‘Abd al-WahhÉb, ShÉh WalÊ Allah DehlawÊ, Intellectual Heritage, Islamic Revival.

Economical Aspects of Cutting Speed Selection When Turning Stepped Parts

1971 ◽  
Vol 93 (4) ◽  
pp. 1113-1119 ◽  
Author(s):  
L. Kops
Keyword(s):  
Cutting Speed ◽  
Minimum Cost ◽  
Turbine Disk ◽  
Constant Speed ◽  
Graphical Form ◽  
Propeller Shaft ◽  
Analytical Comparison ◽  
Speed Selection ◽  
Time Required ◽  
Speed Method

The concept is developed of analytical comparison between two methods of cutting speed selection when cutting stepped parts: the constant rpm method and constant cutting speed method. Formulas for cost and time of machining stepped parts are derived and analyzed for two different examples of stepped parts: short ones with large differences in diameters (turbine disk) and long ones with small differences in diameters (propeller shaft). The results presented in graphical form show the advisable operating regions for the use of one of the two methods considered. The effect of time required to change the rpm on the effectiveness of the constant speed method is examined and the limit of applicability is determined. It is found that a reduction of as much as 1/3 in cost and time may be obtained when the constant speed method is applied in the case of the turbine disk. It is noted also that the minimum-cost speed and minimum-time speed depend on the choice of the method and on the shape of the machined part as well. The conclusions set out the conditions under which the use of the constant cutting speed method is justified.

Dimensional Analysis of Thermal Fields Surrounding Friction Stir Welding Process

2014 ◽  
Author(s):  
Lewis N. Payton ◽  
Vishnu Vardhan Chandrasekaran ◽  
Wesley S. Hunko
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Welding Process ◽  
Temperature Fields ◽  
Analytical Comparison ◽  
Friction Stir ◽  
Thermal Fields ◽  
Designed Experiment ◽  
Pi Theorem ◽  
Alloy 6061

A dimensionless correlation is developed based on Buckingham’s Pi-Theorem to estimate the temperature fields generated by the movement of a tool during the Friction Stir Welding of an aluminum alloy (6061-T6). Symmetrical thermocouple measurements are taken during a statistically designed experiment using different factor levels (RPM, Traverse, etc). Analytical comparison (using multivariate ANOVA) validates the predicted dimensionless correlation including the often-reported difference between the advancing versus retreating side of the Friction Stir Tool.

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