نتایج جستجو برای: industries noise
تعداد نتایج: 240719 فیلتر نتایج به سال:
Introduction: The sound pressure levels caused by work environment noise, along with the effects and ways of reducing it, are one of the most important issues in the manufacturing industry. Noise is the most common pollutant in the industrial environment, which can cause many disorders in various organs of the body, such as the auditory and vascular systems. This study aimed to investigate the ...
We propose a systematic method for creating constellations of unitary space–time signals for multiple-antenna communication links. Unitary space–time signals, which are orthonormal in time across the antennas, have been shown to be well-tailored to a Rayleigh fading channel where neither the transmitter nor the receiver knows the fading coefficients. The signals can achieve low probability of e...
Introduction: Occupational exposure to excessive noise is commonly encountered in a large number of industries in Iran. This study evaluated the hearing threshold and hearing loss in Meybod tile factory workers. Methods: This cross-sectional study included 371 tile factoryworkers during summer and autumn of 2005. Current noise exposure was estimated using sound level meter .A specially formatt...
This study focuses on identifying source and frequency of noise pollution in Yazd, Iran. For data collection, we used two approaches: First we selected 55 monitoring stations for 122 km grid network; the distance between two stations was 2 km. Then, at the same time, we measured the sound pressure level (SPL) at main roads; the distance between two monitoring stations in this case was 1 km. Aft...
The aim of this article is to provide a broad overview of current and future noise reduction technologies used in aircraft industries. It starts by recalling the regulation framework and the European incentives that have triggered efforts in this domain, as well as the major dedicated EU research programs. Then, technologies are introduced in four parts: engine nacelle, fan, jet and exhaust tec...
This chapter describes applications of ammonia in agriculture, pharmaceutical and environmental industries and optoelectronic methods of its detection. In Section 2 the discovery, the chemical structure, reactivity and application of ammonia are reviewed. Applications in agriculture, cleaning products, pharmaceutical industries, beauty products, the benefits and dangers of ammonia to human heal...
The purpose of this study was to establish the validity and reliability of a hydrostatic weighing method using total lung capacity (measuring vital capacity with a respirometer at the time of weighing) the prone position, and a small oblong tank. The validity of the method was established by comparing the TLC prone (tank) method against three hydrostatic weighing methods administered in a pool....
Introduction: Individuals’ jobs performance is one the most important factors in industries and organizations. The aim of the present study was to investigate the simultaneous effect of exposure to noise, lighting and heat stress on the workers’ job performance. . Material and Method: In this analytical-descriptive study, 30 employees of the auto parts manufacturer, in Tehran city, were chose...
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