نتایج جستجو برای: impact energy

تعداد نتایج: 1387768  

ژورنال: Journal of Railway Research 2014
Hosseini, Amirsaeed, Hosseini Tehrani , Parisa ,

At the collision time, a lot of energy is generated during a short period of time that causes large deformations in bodies. One of the most important parts of wagon in railway is a buffer which may absorb the energy during an impact. It should be mentioned that normal buffers only absorb the energy resulted from a crash elastically. In the present paper, it is tried to use inversion mode of ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه سیستان و بلوچستان 1390

a one dimensional dynamic model for a riser reactor in a fluidized bed catalytic cracking unit (fccu) for gasoil feed has been developed in two distinct conditions, one for industrial fccu and another for fccu using various frequencies of microwave energy spaced at the height of the riser reactor (fccu-mw). in addition, in order to increase the accuracy of component and bulk diffusion, instanta...

Charpy impact energy of functionally graded steels in the form of crack arrester configuration was investigated. Functionally graded steels which contain layers of ferrite, austenite, bainite and/or martensite could be produced by electroslag remelting. The results showed that notch tip position and the distances of notch with respect to the bainite and martensite layers significantly affect th...

Journal: :journal of rehabilitation in civil engineering 2013
rui c. barros h. naderpour s.m. khatami a. mortezaei

building pounding occurs between two adjacent buildings with small gap or without sufficient separation distance. it leads to damage buildings during earthquake due to impact. many researchers have investigated building pounding based on impact force reduction and energy dissipation increase, when two buildings collide with each other. in numerical investigations, using specific link element, i...

Energy as one of the most important factors of production, as well as one of the most important marginal products, has effential role in trade and economic development.The importance of energy has increased after the two oil crises in 1970’s. The relationship between energy and trade is an important topic to study for several reasons. If energy consumption is found to Granger cause export...

Journal: :اقتصاد و توسعه کشاورزی 0
رمضانی امیری رمضانی امیری زیبایی زیبایی

abstract intensive and inefficient use of energy leads to degradation of natural resources and environmental problems. this study evaluated the relationship between the energy of consumed inputs and yield of tomato, cucumber and melon using the cobb–douglas production function. the data were collected from 90 farmers in firoozabad using a questionnaire. the farmers were chosen by simple random ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه علامه طباطبایی 1391

this research is about the political economy of china in central asia. in this research the political & economic interactions affected on chinas political economy in central asia are examined. chinas goal of presence in central asia including political-security, economic and energy goals is described in one part. in another part, the trade relations between china and central asian countries ar...

Journal: :journal of the structural engineering and geotechnics 0
mohammad mahdi kheirikhah faculty of industrial and mechanical engineering, qazvin branch, islamic azad university, qazvin, iran sajjad dehghanpour faculty of industrial and mechanical engineering, qazvin branch, islamic azad university, qazvin, iran mohsen rahmani faculty of industrial and mechanical engineering, qazvin branch, islamic azad university, qazvin, iran

assessing the behavior of composite structures which are subjected to impact loads is one of the important subjects in the field of mechanical sciences. using thin-walled tubes which collapsed and absorbed the impact energy is a well-known method to prevent damages to the other parts of the structures. in this paper, deformations, crushing length, peak load, mean force and energy absorption cap...

Journal: :مهندسی بیوسیستم ایران 0
بنیامین حوشنویسان دانشجوی کارشناسی ارشد، دانشکدۀ مهندسی و فناوری کشاورزی پردیس کشاورزی و منابع طبیعی دانشگاه تهران شاهین رفیعی استاد، دانشکدۀ مهندسی و فناوری کشاورزی پردیس کشاورزی و منابع طبیعی دانشگاه تهران محمود امید استاد، دانشکدۀ مهندسی و فناوری کشاورزی پردیس کشاورزی و منابع طبیعی دانشگاه تهران علیرضا کیهانی استاد، دانشکدۀ مهندسی و فناوری کشاورزی پردیس کشاورزی و منابع طبیعی دانشگاه تهران مهران موحدی دانش آموختۀ کارشناسی ارشد، دانشکدۀ مهندسی و فناوری کشاورزی پردیس کشاورزی و منابع طبیعی دانشگاه تهران

by increasing crops yield due to intensive use of agricultural machinery and energy inputs, utilizedenergy in agriculture has been increasing rapidly which negative environmental impacts on water,air and soil are its consequences. in this paper, potato production in isfahan province was studiedusing life cycle assessment approach from the standpoint of energy consumption and environmentalimpact...

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This paper tries to demonstrate the importance of non-economic exogenous factors (Underlying Energy Demand Trend) when we estimate the industrial energy demand for Iran. The Structural Time Series Model (STSM) approach is used to model these unobservable factors. The Kalman filter and Maximum Likelihood methods allow us to estimate the value of the UEDT. This approach enables us to obtain more ...

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