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...

background; noise mapping in industry can be useful to assess the risks of harmful noise, or to monitor noise in machine rooms. using gis -based software for plot of noise maps in an indoor noisy work environment can be helpful for occupational hygienists to monitor noise pollution. methods; this study was carried out in noisy packaging unit of a food industry in ghazvin industrial zone, to eva...

large urban areas are facing growing problems of noise pollutions. geospatial information systems (gis) can conveniently be adapted to gather, analyze and present noise information. gis can also be extended to answer to user specific problems through deterministic and statistics models. the objectives of this research were to measure urban traffic noise levels, analyze temporal and spatial dyna...

introduction: among the environmental pollutions, noise is very important for its physiological  and psychological effects on human. traffic noise is one of the most important pollutants and the  hospitals  are  one  of  the  critical  places  regarding  this  type  of  noise.  for  these  reasons,  in  the  summer  of  1382,  the  traffic  noise  of  mashhad  main  streets  around  the  hospit...

background: educational centers have higher standards for controlling noise pollution as it has been shown that noise pollution is a major cause of discomfort for teachers and students. noise pollution reduces concentration, interferes in the conversation, and leads to dropouts and lower grades especially in mathematics. the present study aimed to evaluate noise pollution in the schools of birj...

Noise is essential for the existence of a liquid market, and if noise traders are not present in the market, the trade volume will drop severely and an important aspect of the market philosophy will be lost. However, these noise traders bring noise to the market, and the existence of noise in prices indicates a temporary deviation in prices from their fundamental values. In particular, high-fre...

  Background : Noise pollution and workers' noise exposure are common in industrial factories in Iran. In order to reduce this noise pollution, evaluation and investigation of noise emission are both necessary. In this study, different noise mapping methodsare used for determining the distribution of noise.   Materials and Methods : In the present study, for preparing a noise map i...

Background & Aims of the Study: Noise is one of the most important environmental pollutants. It is a global health problem, especially among industrial workers. Since there was little information about noise levels in small workshops in Qom city, this study aimed to evaluate noise in small workshops and compare it with national standards. Materials and Methods: This was a cross-sectional stu...

  Background: Educational centers have higher standards for controlling noise pollution as it has been shown that noise pollution is a major cause of discomfort for teachers and students. Noise pollution reduces concentration, interferes in the conversation, and leads to dropouts and lower grades especially in mathematics. The present study aimed to evaluate noise pollution in the schools ...

the aim of this paper is to minimize output phase noise for the pure signal synthesis in the frequency synthesizers. for this purpose, first, an exact mathematical model of phase locked loop (pll) based frequency synthesizer is described and analyzed. then, an exact closed-form formula in terms of synthesizer bandwidth and total output phase noise is extracted. based on this formula, the phase ...