نتایج جستجو برای: equivalent sound pressure level
تعداد نتایج: 1647037 فیلتر نتایج به سال:
The splashing of water drops on a soil surface is the first step of water erosion. There have been many investigations into splashing-most are based on recording and analysing images taken with high-speed cameras, or measuring the mass of the soil moved by splashing. Here, we present a new aspect of the splash phenomenon's characterization the measurement of the sound pressure level and the sou...
OBJECTIVE To analyze the level of noise at the workplace environment among Physical Education teachers during indoor bike classes and its association with some aspects of health. METHODS Cross-sectional study carried out in 15 different gyms with 15 teachers in Rio de Janeiro (Southeastern Brazil) in 2007. A standardized questionnaire, tested in relation to its replication, was used in order ...
The aeroacoustic fields of twin jets and the equivalent single jet were experimentally investigated using particle image velocimetry (PIV), schlieren visualization, acoustic measurement. present study focuses on jets, effect interaction between each was various nozzle spacing. PIV results indicated that strong causes elliptical growth a cross-stream plane decrease in Reynolds stress inner shear...
Introduction: Chronic occupational noise exposure may constitute a risk factor for cardiovascular disease for workers. The aim of this study was to investigate the relationship between occupational noise exposure and noise annoyance with blood pressure, serum cholesterol and triglyceride levels in workers of a textile industry. Material and Method: This cross-sectional study was carried out ...
Muffler is one of the main components of an automotive exhaust system, which reduces the noise of the exhaust system. In this paper, modeling and simulation of the acoustic behavior of a muffler is presented with the aid of an engineering software. For this purpose, firstly, an analytical model is presented to evaluate the sound transmission loss in cylindrical shells based on Sander's theory....
Introduction: In Iran country, small enterprise with less than 10 workers comprise about %90 of all industries and 80% of working population. Noise, higher than the permissible level is among the hazardous agents, workers in these plants facing with. The aim of this study was to investigate the correlation between screening estimation and noise measurement in small plants. . Material and Metho...
There is a growing number of large spaces but their sound fields have not been studied systematically. The aim of this study is to explore the behaviour of reverberation time and sound pressure level in this kind of spaces. Acoustic measurement was carried out in two large spaces. The results show that in the near-source field, the sound pressure level and reverberation time vary rapidly with t...
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