نتایج جستجو برای: sound pressure level
تعداد نتایج: 1531055 فیلتر نتایج به سال:
Introduction: Using diesel generators is necessary for activities like welding in construction sites and it is often accompanied with noise pollution. The aim of this study was to evaluate noise pollution induced by diesel generators in construction activities in one of the districts of Tehran city. Material and Method: In this descriptive study, 14 construction sites were selected for th...
Background and Objective: Noise pollution causes many physiological, psychological, economic and social effects on human life. This issue is more important in the environment of industrial workplaces. This research aimed to adopt the functions of GIS for evaluating and spatial analysis of noises in industrial environments. Materials and Methods: At the initial step, the spatial data for indust...
Abstract: Background and aims: Using water pump in residential buildings to provide the required water pressure is accompanied by noise pollution and the annoyance of residents. So, the purpose of this study is to reduce water pump noise pollution with designed acoustic curtains in a residential building of Qazvin city. Methods: The mean sound pressure level was measured before and ...
Background: Noise pollution is one of the common physical harmful factors in many work environments. The current study aimed to assess the personal and environmental noise level and project the sound map of an Iranian tire manufacturing complex using Surfer V.14 and Noise At Work tools. Materials and Methods: This descriptive study was conducted in the curing hall [including curing, sandblast,...
Background & Aims: In addition to the adverse effects of noise in the auditory system, non-auditory effects can be regarded as factors which cause physiological harassment, discomfort and also disorder in cognitive functions. The present study aimed at determining cognitive function after exposuring to different levels of sound pressure level in a clinical trial study. Materials & Metho...
It is accepted that noise pollution has a major impact on health, such as physical, physiological, psychological and performance related effects, all over the world. This study aims to evaluate noise pollution in four urban parks located in Sanandaj City, Iran and to zone it in GIS environment. Sound pressure level (SPL) and maximum sound level (Lmax) were measured at 45 points (each point was ...
Aerospace engines testing is a source of noise pollution and determining the low frequency acoustic characteristics of the test cell, plays an important role in optimally control of the sound field and reducing the level of sound pressure and pollution. In this study, the drop in average sound pressure level is numerically predicted by constructing a test cell according to ISO 140 standard. To ...
the aim of the present study was to examine the rate of noise induced hearing loss in a group of punching and cutting section and other occupational groups workers and its relation with sound pressure levels, age and work history. this descriptive, cross-sectional study included 245 workers of the punching and cutting section and other occupational groups of an iranian axial parts factory in 20...
Introduction: Vehicle engine id one of the main sources of noise which its level is influenced by various parameters. The aim of this study was to investigate the impact of motor oils quality before and after oil change on the variability of vehicle engine induced noise level. In this study it is tried to follow-up the efficacy of motor oil quality on engines sound level. .Material and Method...
Determining the Hydro-acoustic Characteristics of the Ship Propeller in Uniform and Non-uniform Flow
This research has been carried out to determine the marine propeller hydro-acoustic characteristics by Reynolds-Averaged Navier-Stokes (RANS) solver in both uniform and non-uniform wake flow at different operating conditions Wake flow can cause changes in pressure fluctuation and gas effect on propeller noise spectrum. Noise is generated by the induced trailing vortex wake and induced pressure ...
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