نتایج جستجو برای: low frequency vibration

تعداد نتایج: 1624419  

Journal: :journal of petroleum science and technology 2015
chunsheng pu liming zheng jing liu jiaxiang xu

foam injection is widely applied in amounts of fields to drilling, production, and formation protection. sometimes, the application result is disappointing, which is caused by the failure of bubble generation in foam flooding. therefore, it is necessary to seek ways for improving the performance of foam injection. an increased disturbance to the stratum, like the vibration caused by a seismic o...

Journal: :تحقیقات موتور 0
محمد رضا قاسمی m.r. ghassemi یوسف حجت y. hojjat

today there are different vibration isolators used in industries according to the weight and excitation frequency of the machines which have vibration. one of them is air spring which is in two types: convoluted air spring and membrane air spring. convoluted air springs are used to control vibrations in low frequency (usually lower than 10 hz) and the membrane ones are used in high frequency (u...

ژورنال: تحقیقات موتور 2010
حجت, یوسف, قاسمی, محمد رضا,

Today there are different vibration isolators used in industries according to the weight and excitation frequency of the machines which have vibration. One of them is Air Spring which is in two types: Convoluted air spring and membrane air spring. Convoluted air springs are used to control vibrations in low frequency (usually lower than 10 Hz) and the membrane ones are used in high frequenc...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه تحصیلات تکمیلی صنعتی کرمان - پژوهشکده برق و کامپیوتر 1390

a phase-locked loop (pll) based frequency synthesizer is an important circuit that is used in many applications, especially in communication systems such as ethernet receivers, disk drive read/write channels, digital mobile receivers, high-speed memory interfaces, system clock recovery and wireless communication system. other than requiring good signal purity such as low phase noise and low spu...

2011
Gunawan Setia Prihandana Muslim Mahardika M. Hamdi Kimiyuki Mitsui

High-frequency vibration aided EDM has become one of the ways to increase material removal rate in EDM process, due to the flushing effect caused by vibration. However, utilizing high-frequency vibration, especially in ultrasonic range consumes a lot of setup cost. This work presents an attempt to use a low-frequency vibration on workpiece of stainless steel (SS 304) during EDM process. The wor...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده ادبیات و علوم انسانی دکتر علی شریعتی 1393

this study aimed at examining the effects of iranian efl learners’ anxiety, ambiguity tolerance, and gender on their preferences for corrective feedback (cf, henceforth). the effects were sought with regard to the necessity, frequency, and timing of cf, types of errors that need to be treated, types of cf, and choice of correctors. seventy-five iranian efl students, twenty-eight males and forty...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه اصفهان - پژوهشکده تربیت بدنی و علوم ورزشی 1391

چکیده معضل چاقی به عنوان عارضه ای جدی برای زندگی بی تحرک و ماشینی، مورد توجه اغلب مراکز بهداشتی و درمانی دنیا قرار گرفته است. چاقی عامل زمینه ساز و در واقع عامل خطری برای بروز بیماری های قلبی - عروقی است که عموماً با کاهش طول عمر مورد انتظار و افزایش بیماری همراه است. هدف پژوهش حاضر تأثیر 12 هفته تمرینات ویبریشن کل بدن، تمرینات هوازی و تمرینات ترکیبی( هوازی و ویبریشن کل بدن) بر ترکیب بدنی زنان ...

Foam injection is widely applied in amounts of fields to drilling, production, and formation protection. Sometimes, the application result is disappointing, which is caused by the failure of bubble generation in foam flooding. Therefore, it is necessary to seek ways for improving the performance of foam injection. An increased disturbance to the stratum, like the vibration caused by a seismic o...

2014
Lifeng Pan

The hydropower generating units’ vibration parameter is an important indicator to monitor its rollstabilization. To measure the low-frequency vibration of the large and middle scale of hydropower generating units, according to frequency characteristic compensation principle of the vibration sensor, a low-frequency compensating circuit was designed to extend the frequency characteristic to the l...

Journal: :نشریه دانشکده فنی 0
حسین یدالله تبار حسن ثقفیان محمود شهبازی سعید شبستری

this research concentrates on the effects of low frequency, vertical mechanical vibration during solidification on the microstructure and mechanical properties of a380 aluminum alloy. two series of sr-modified and al-5ti-b grain refined a380 alloy samples were solidified in both static and dynamic conditions in the frequency and amplitude of 60 hz and 0.2 m, respectively. their physical, micro-...

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