نتایج جستجو برای: sound pressure level
تعداد نتایج: 1531055 فیلتر نتایج به سال:
بررسی تاثیر سر و صدا بر میزان خطا و سرعت انجام کار با استفاده از آزمون ارگونومیکی هماهنگی بین دو دست
Background and aims : The most important factors that influence human performance are accuracy, speed and ability to perform the skills by individuals. Given the importance of human productivity in improving the production and quality, This study examines the impact of noise on error rate, speed and ability to perform the manual skills. Methods : This experimental study was conducted on 96 ...
Identifying the quantitative relationship between the sound pressure level and noise annoyance for environmental noises is important from the viewpoint of noise assessment. In this study, a method for predicting the probabilistic evaluation quantities like Lx ((100−x) percentile level) and LAeq (equivalent A-weighted sound pressure level) of the noise environment is proposed by introducing a no...
Background and aims: Discharging compressed air through conventional single jet nozzles or open pipes is a common jet noise in industry. This study is aimed to reduce air blow gun jet noise by designing and fabrication of multiple jet nozzle as a substitute for conventional single jet nozzles. Methods: One of the most common commercial air blow gun equipped with a conventional single j...
Sound-related behavioural studies explore the effects of sound on underwater animals in tanks under controlled laboratory conditions. In this study, we aim to assess sound pressure distributions and gradients in a small-sized water-filled tank that can be used in behavioural studies to examine anthropogenic sound effects on fish and invertebrates and to raise awareness among scientists in the f...
This paper presents noise problems associated with the use of air-turbine drills in dental practice. Two hundred and fifty dentists (male and female) were randomly selected from the faculty of dentistry as well as the dentists who worked private in Tehran. The results indicated that the mean value of sound pressure level produced by the high-speed drills was 69.1 db. Most of the energy from...
conclusions according to the results of this study, with increasing load of traffic, there is an increasing need for proper consideration plans to control noise pollution and prevent its effects. results according to the research findings, the equivalent sound pressure levels in all stations were 76.28 ± 3.12 db (mean ± sd). according to sound measurements and the survey questionnaire, noise po...
The fluidization behavior of silica gel was tested in a fluidized bed under different sound pressure levels and sound frequencies. It has been found that the particle mixtures can be fluidized smoothly with sound assistance at low sound frequency owing to the sound energy disrupting large size of agglomerates. The minimum fluidization velocity was found to decrease with increasing sound frequen...
In this paper, we design, simulate, and build an ultrasonic heat generator. In thermoacoustics, heat generated by the passage of alternating current through a thin conductor produces a sound wave. In this method, unlike other methods of sound production, moving parts are not used to vibrate air molecules, and as a result, the frequency response of these generators is flatter than other sound ge...
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