نتایج جستجو برای: the attenuation parameters

تعداد نتایج: 16108098  

ژورنال: سنجش و ایمنی پرتو 2014

Precise measurement of void coefficient in two phase flow is one of important parameters in thermal hydraulic parameters such as average density, two phase flow pressure drop and two phase flow pattern. In this study the void coefficient has been correlated experimentally based on attenuation coefficient gamma ray emitted form 137Cs source passing a rectangular channel. The average void fractio...

Introduction: Globally, the need for radiotherapy as a part of cancer management increases every year. Thus, the shielding for megavoltage radiotherapy rooms is of great importance. Materials and Methods: In the present study, 14 types of developed high-density concrete with densities ranging from 2.45 to 5.11 were simulated by using Monte Carlo method. The linear attenuation coefficient and t...

A probabilistic seismic hazard assessment in terms of Arias intensity is presented for the city of Tehran. Tehran is the capital and the most populated city of Iran. From economical, political and social points of view, Tehran is the most significant city of Iran. Many destructive earthquakes happened in Iran in the last centuries. Historical references indicate that the old city of Rey and the...

ژورنال: سنجش و ایمنی پرتو 2018

Using of X-rays in different industries and especially in medical application is increasing. In this regard, designing of light and efficient protective material based on polymeric nanocomposites and precise study of the effect of adding nanoparticles with different sizes on the X-ray attenuation is necessary. In this study the epoxy nanocomposites with different percentages of copper oxide nan...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه بیرجند - دانشکده علوم انسانی 1389

abstract amino acids are building blocks of proteins, and play a vital role in living beings existence and their functionality. the interaction of these compounds with metal ions is of great importance to biochemists, and chemists, because their functions can be utilized as a model in understanding enzymes mechanism for transport of metal ions to tissues. among twenty essential amino acids w...

Golsar is located in north-west of Rasht the capital city of Guilan province. This region, according to standards 2800, is identified among the regions with relatively high risk of earthquake. A set of historical and instrumental seismicity data used in radius of 200 km which covers the period twelveth century until now. Kijko method has been applied for estimating for parameters considering of...

1999
Wei Zhang Nader Moayeri

Abstract A fundamental quantity in the calculation of rain attenuation statistics is the specific attenuation (attenuation per unit distance). The power-law form of rain specific attenuation is very convenient and is commonly used. It is expressed as α R k ⋅ , where k and α are the power-law parameters, and R is the rain rate in mm/h. Limited number of power-law parameters were available in the...

Abstract- Communication has become inevitably part of our day to day activities, in academic, business, banking, and other sectors. It has therefore become so important to implement good and efficient communication system. A reference point according to this research is the wireless sensor networking (WSN) system, and most important thing in communication is to be free from interference, attenu...

A. Darvizeh M. Darvizeh, R. Ansari, R. Rajabieh Fard

In the present work, FGM shells integrated with magnetostrictive layers acting as distributed sensors and actuators are modeled to control vibration attenuation of FGM shells with simply supported boundaryconditions. To achieve a mechanism for actively control of the oscillation amplitude of the integrated structure, a negative velocity proportional feedback control law is implemented in the st...

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