نتایج جستجو برای: equivalent sound pressure level

تعداد نتایج: 1647037  

عسگری, اسرافیل, محوی, امیر حسین, مصداق نیا, علیرضا, ندافی, کاظم, یوسفیان, مسعود,

Background and Objective: Noise pollution is an important environmental problem that may cause hazardous effects, such as hearng loss, sleep disorders, hypertension and digestive problems in communities. To prevent these effects, achieving recommended standards of noise pollution measuring in cities is mandatory. This study was aimed to evaluate noise pollution in zanjan city in 2007. Materials...

Journal: :تحقیقات نظام سلامت 0
رستم گلمحمدی دانشیار گروه مهندسی بهداشت حرفه‎ای، دانشکده بهداشت و مرکز تحقیقات علوم بهداشتی، دانشگاه علوم پزشکی همدان، همدان، ایران محسن علی آبادی ستادیار گروه مهندسی بهداشت حرفه‎ای، دانشکده بهداشت، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی همدان، همدان، ایران ابراهیم درویشی عضو مرکز تحقیقات بهداشت محیط و مربی گروه مهندسی بهداشت حرفه‎ای، دانشکده بهداشت، دانشگاه علوم پزشکی و خدمات بهداشتی درمانی کردستان، سنندج، ایران

background: in the steel industry, coke-fueled furnaces are used for smelting iron ore to produce cast iron are considered as sources of annoying noise.this study aims to evaluate the noise pollution blast furnace and sound source characteristics in order to present noise control measures in the steel industry. methods: measurement of noise level and its frequency analysis was performed using s...

Journal: :health scope 0
sahand ghafori department of occupational health, faculty of medical sciences, tarbiat modares university, tehran, ir iran ali khavanin department of occupational health, faculty of medical sciences, tarbiat modares university, tehran, ir iran; department of occupational health, faculty of medical sciences, tarbiat modares university, tehran, ir iran. tel: +98-2182883564 hassan assilean department of occupational health, faculty of medical sciences, tarbiat modares university, tehran, ir iran ardalan solimanian department of occupational health, faculty of medical sciences, tarbiat modares university, tehran, ir iran

conclusions use of flexible joint in the exhaust system leads to conversion of linear vibration to non-linear one, resulting in significant reduction of noise levels. results by using this new exhaust at speed levels of 1000, 2000, 3000, 4000, and 5000 rpm, we had respectively 3.9, 6.8, 7.4, 5.6, and 5 dba decreases in total sound level pressure. objectives this study aimed to reduce motorcycle...

ژورنال: سلامت کار ایران 2014

  Background and aims: In the steel industry, air blowers used to supply compressed air are considered as sources of annoying noise . This study aims to design an acoustic room chamber in order to control the noise level of the air blower.   Methods: Measuring of the noise level along with frequency analysis was performed by using sound level meter, model ofCASELLA-Cell.450 . Dosimetery was per...

ژورنال: سلامت و محیط زیست 2011
اصلانی, حسن, قنبری, محمد, مسافری, محمد, ندافی, کاظم, یونسیان, مسعود,

Background and Objectives: Over the last three decades environmental pollutions became a more noticeable problem in all around of the world. In many countries, noise pollution as a basic problem has a great importance.Development of the city, increasing of industrial centers, increasing vehicles, other annoying noise resources and also little information about the noise pollution of Tabriz city...

2008
L. P. R. de Oliveira B. Stallaert W. Desmet P. Sas K. Janssens H. Van der Auweraer

Active noise control systems tend to be designed with a target on sound pressure level reduction. However, the perceived control efficiency for the occupants can be more accurately assessed if psychoacoustic metrics are taken into account. The aim of this paper is to evaluate the effect of an adaptive structural acoustic controller on the sound quality of engine noise in a vehicle mockup. The e...

Journal: :Acoustics 2023

The study aims to diagnose the sound pressure levels inside incubators in a controlled environment under free-field conditions. tests were carried out semi-anechoic room standard UNE-EN ISO 3745:2012/A1:2018 three different operating states: off, on, and on with temperature alarm triggered. Sound analyzed models of incubators, both outside. main noise indices corrected equivalent continuous lev...

A Ahmadi Orkomi, A Noorpoor, B Tavakoli ,

  Background : Cement industry has many process units. Basically all of these units can be considered as a source of noise. Since noise pollution is defined based on its offensive hearing effects, the importance of the noise sources depends directly on the number of workers in the unit.   Materials and Methods : An experimental study has been done at Tehran cement factory to recogn...

Journal: :Sound and Vibration 2021

Noise pollution is one of the common physical harmful factors in many work environments. The current study aimed to assess personal and environmental sound pressure level project sound-Isosonic map Razavi Khorasan Paste manufacture using Surfer V.14 at V.5.0. This cross-sectional, descriptive analytical that was conducted 2018 factory contains Canister, production Brewing unit. Following ISO 96...

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...

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