نتایج جستجو برای: noise standard

تعداد نتایج: 696617  

In this paper, an intuitive analysis of a phase noise reduction technique is done, and then a modified structure is proposed to achieve higher phase noise reduction than the original one. This method reduces the impact of noise sources on the phase noise by decreasing closed-loop gain in zero-crossings points and moving this high closed-loop gain to the non-zero-crossings points. This reduction...

Journal: :journal of physical & theoretical chemistry 2014
hossein tajabadipour mehdi shahidi nima karachi

vanillin is an interesting corrosion inhibitor because of its safe use and high solubility inwater. the effect of vanillin on the corrosion inhibition of carbon steel in 1.0 mhydrochloric acid solution has been studied using potentiodynamic polarization,electrochemical impedance spectroscopy (eis) and electrochemical noise (en) techniques.the effect of temperature on the rate of corrosion in th...

Introduction and purpose: Noise pollution can exert negative effects on mental health. In this regard, the present study aimed to evaluate the noise levels in sugar factory of Debal Khozaei agro-industry complex in 2018. Methods: For the current study, sound and audio parameters were measured using a sound meter. These audio parameters included sound pressure level and minimum and maximum valu...

  Background: It has been prover that the prevalence of experiencing job related stress is very high among the dentists. This stress can be the result of factors such as poor lightening of dental office and noise. This stress can cause emotional distress and threaten dentists’ physical health and affect the quality of their life. This study is conducted to determine dentists’ p...

خرمیان, داریوش, سیستانی, سروش, هاشمی ملایری, بیژن,

Introduction: Noise and spatial resolution (SR) are the main characteristics of image quality in CT scanning affected by different radiation and technical parameters. One of the important parameters are reconstruction kernels. Different reconstruction kernels are used for noise reduction and/or edge-enhancement purposes. In this study, we investigate some reconstruction kern...

Journal: :international journal of occupational hygiene 0
seyedehzahra jalilzadeh islamic republic of iran broadcasting university, tehran, iran. mohammad asgari islamic republic of iran broadcasting university, tehran, iran. mohammadebrahim sadeghi islamic republic of iran broadcasting university, tehran, iran.

acoustic experimental data of irib (islamic republic of iran broadcasting) server room was taken to measure the acoustic noise characteristics of frequency and sound pressure level (spl). the purposes of this paper are measuring the noise pollution and its evaluation through the regulations. the measurements were taken in two stages. the first one was taken at 10 points by sound investigator 22...

ژورنال: سلامت کار ایران 2011
خانجانی, نرگس, جعفری ندوشن, رضا, حلوانی, غلامحسین, سلمانی ندوشن, مجاهده, قطبی, محمدرضا, منظم , محمدرضا,

  Background and aims  During last decades one of the hazardous agents on workers health has been workplaces noise. The aim of this study was to investigate the level of noise exposure in different jobs and noise induced permanent threshold shift in relation to noise level and work experience.   Methods  This is a cross-sectional and descriptive study that performed among total workers. Dosimet...

ژورنال: ارگونومی 2016
بیابانی, اعظم, علی آبادی, محسن, گلمحمدی, رستم,

Introduction: Nominal noise reduction rate of the earmuff manufacturers can be different compared with the actual attenuation rate. The present study aimed to determine the actual noise reduction rate of common hearing protection devices using microphone in real ear method. Materials and Methods: In this study, five brands of common earmuffs used in Iranian industries were investigated on 30...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید