نتایج جستجو برای: noise sources

تعداد نتایج: 473529  

Journal: :IEEE Trans. Instrumentation and Measurement 2001
J. Randa Lawrence P. Dunleavy Leon A. Terrell

We report results of stability and repeatability measurements performed on a selection of different noise sources for selected frequencies between 12 GHz and 26.5 GHz. Measurements cover intervals classified as intermediate term (about 1 week) and long term (about 1 year or more). Noise sources measured include a commercial diode source, a gas-discharge source constructed by NIST, a specially m...

ژورنال: طب کار 2016

Introduction: A hospital as a health care institution providing  treatment services can be heavily influenced by sources of noise. Noise pollution has negative impacts on patient comfort and staff welfare. This study aimed to evaluate the relationship between noise annoyance and sensitivity with noise parameters (PNC, SIL) in the hospitals of Behbahan. Methods: This study...

ژورنال: تحقیقات موتور 2018
Asadi, M., Baloo, M., Jafari, M. J.,

Valvetrain is one of the major sources of noise and vibration in IC engines. The importance of cam surface quality parameters is highlighted in the valve train mechanisms with direct sliding contact between cam and tappet. In this paper, the influence of surface quality parameters on high frequency noise producing is investigated. The roughness and waviness of some intake and exhaust camshafts ...

Journal: :international journal of environmental research 2010
h. mehravaran s. zabani gh.r. nabi bidhendi r. ghousi h. keshavarzi shirazi

the equivalent noise level in large cities has been growing due to the population growth, uncontrolled production of cars, and the existence of worn out cars. on the other hand, heavy traffic has increased the amount of noise problems for residents of medical and educational centers, research institutes and residential area (or sensitive centers to noise) built in highway bounds and it has also...

گلمحمدی , رستم ,

For assessing of impact Noise which is produced by pneumatic breaker, a study was performed in Hamadan during summer 1995.32 Kg pneumatic breakers of five services organizations were studied. Results show: background Noise, including Environmental and Air compressor Noise are in the range of 87 dBA-101 dBA and different in various type of cases. According to this study, SPL of breaker during ...

In this paper, a stochastic term is added to the classical generalized nonlinear Schrödinger Equation to describe the noise generated when light pulses propagate in a fiber. It has been shown that the generated supercontinuum light source fluctuates up to 50% of its output temporal intensity profile due to noises of different sources. The simulation method devised has been applied to the propag...

Journal: :NOISE-CON ... proceedings 2023

Electric vehicles (EVs) constitute an increasing share of the vehicle fleet, in particular regarding light vehicles. This ratio may be significantly enhanced urban areas that favour access to low-emission Acknowledged quieter than conventional due a lower propulsion noise, EVs feature comparatively heightened tyre-road noise contribution, further reduction which can achieved by selecting approp...

ناظم, فرزاد, پیری, خسرو, کریمی, امیرحسین,

Background: There is a long history of using physical activities and herbal medications to cure psychological diseases such as stress and anxiety. The aim of this study was to assess the effect of training, extract of Althaea kurdica flower and noise stress on the anxiety of Wistar male rats. Methods: Thirty-five male rats were randomly divided into five groups: the noise group (n=7), traini...

Journal: :jentashapir journal of health research 0
leila ibrahimi-ghavam abadi department of environmental management, ahvaz branch, islamic azad university, ahvaz, ir iran behzad foualdi dehaghi department of occupational health, school of public health ahvaz, jundishapur university of medical sciences, ahvaz, ir iran; department of occupational health, school of public health ahvaz, jundishapur university of medical sciences, ahvaz, ir iran. tel/fax: +98-61337385318 siamak kavoosi department of hse, national iranian drilling company, ahvaz, ir iran

conclusions our results showed that only 17% of the measured points in the oil drilling rig floor were in safe area; 39% were in caution area and 44% were in danger area. in the camp facilities area, 51% of the points were in safe area, 38% were in caution area and 11% in danger area. the main sources of noise exposure in the rig floor area were power generators. materials and methods this was ...

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