نتایج جستجو برای: sound pressure load

تعداد نتایج: 643260  

Journal: :TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C 2006

سموات, حمید, علیایی, محمد, معتمد زاده, مجید, گلمحمدی, رستم ,

Introduction & Objective: Noise is one of the most important harmful agents in work environment. In spit of industrial improvements, exposure with over permissible limit of noise is counted as one of the health complication of workers. In Iran, do not exact information of the absorption coefficient of acoustic materials. Iranian manufacturer have not laboratory for measured of sound absorbanc...

Hamzavi, Rostam, Younesian,

In recent years, need to increase the convenience of trips in railway vehicles causes that train operators and manufacturers focus on reducing the noise level which is sensed by passengers. In this paper, first the state of modeling acoustic noise in cab train is discussed and natural frequencies and acoustic mode shapes are derived and then formulation of acoustic pressure in the cab will be o...

Journal: :The Journal of the Acoustical Society of America 2012

Journal: :ماشین های کشاورزی 0
احمد شریفی مالواجردی محمد یونسی الموتی احمد محسنی منش

soil compaction can occur as a result of a number of factors. one of the most important factors is soil response to pressures imposed by wheels and soil engaging tools. this research investigated the effect of tyre load and inflation pressure on soil compaction-related factors. these factors include rut width, rut depth, cone index and horizontal force in different layers of soil profile. in th...

Journal: :international journal of occupational hygiene 0
samaneh momen-bellahfard department of environmental science, graduate school of the environment and energy, science and research branch, islamic azad university, tehran, iran. mohammadreza monazzam department of occupational hygiene, school of public health and center for air pollution research (capr), institute for environmental research (ier), tehran university of medical sciences, tehran, iran.

environmental noise pollution is among the most urban problems which can be caused due to real sources like traffic, train and virtual sources provided by rigid surfaces. one of the urban structures in which can perform as a virtual noise source are the installed gutters alongside highways. these structures are mostly used to pass the wastewater or the rainfall. in this research, the acoustical...

The purpose of this article is to provide an analytical model of the vibroacoustic for an elastic beam submerged in low subsonic flows with mean velocities. In general, vibroacoustic modeling refers to the combined effects of sound propagation and mechanical vibration of the structure. Sound radiations from submerged structures are coupled with physical phenomena because the sound pressures act...

Journal: :journal of research in health sciences 0
mohammad reza monazzam rostam golmohammadi maryam nourollahi samaneh momen bellah fard

background: noise is one of the most important harmful agents in work environment. noise pollution in oil refinery industries is related to workers' health. this study aimed to determine the overall noise pollution of an oil refinery operation and its frequency analysis to determine the control plan for a vent noise in these industries. methods: this experimental study performed in control unit...

Journal: :acta medica iranica 0
m. ameli

the cardiac action of phenoxybenzamine (dibenzyline) was studiedusing the maximum rate of pressure rise in the left ventricle as a measure of myocardial contractility. cardiac function was assessed by increasing the pressure load on the heart and measuring contractility as reflected by dp/dt. dibenzyline was found to change the cardiac response to pressure load. the rate of pressure increase in...

اعتمادی نژاد , سیاوش, علی زاده , احمد, محمدیان , محمود, یزدانی چراتی , جمشید,

Background and purpose: Noise is one of the most harmful factors in the environment. It is also one of the harsh phenomenons in this century that people are exposed to. Exposure to noise higher than threshold limit value could cause some physical and mental disorders. High traffic flow due to recent increase in number of vehicles causes higher noise pollution. There are few studies regarding ...

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