in recent years, need to increase the convenience of trips in railway vehicles causes that train operators and manufacturers focus on reducing the noise level which is sensed by passengers. in this paper, first the state of modeling acoustic noise in cab train is discussed and natural frequencies and acoustic mode shapes are derived and then formulation of acoustic pressure in the cab will be o...

Jet noise is a common problem in minimum quantity lubrication (MQL) technology. This should be given great attention because of its serious impacts on the physical and mental health operators. In this study, micro-grooved nozzle proposed based reduction concept biological micro-grooves. The flow field acoustic characteristics an original were investigated numerically to help better understand m...

in this paper the interior noise level of a vehicle due to structural vibration, named structure borne noise, as a part of nvh analysis has been investigated. first structural analysis is performed and vibrational behavior of structure carried out due to power plant excitations. then interior acoustic cavity response for such excitation and resultant noise is determined. vibrational analysis is...

A kind of noise is dominated by broadband noise with low frequency tonal components. To achieve noise control on whole frequency band, it is necessary to implement hybrid control technique combining passive control and active control. There are three methods to combine passive control and active control, including active control in passive enclosures, active control outside passive enclosure an...

There are at least two challenges that the jet engine noise community is currently facing. One challenge is due to existing engines that are being extended to higher power ratings without increasing the passive noise control treatment area. The second challenge comes about with the increasing trend to go to ultra-high bypass engines. This increases the importance of the fan tone noise and at th...

Background and Aim: Exposure to impact noise (short-term, high intensity) higher than permitted levels results in injury to the auditory system. Armed forces are one of the occupational groups exposed to these types of noises resulting from gunshots. In this study, relevant articles and research on the adverse effects of impact noise, hearing loss, and tinnitus in armed forces and effective con...

Background: The recruitment of medicinal herbs for the treatment of psychological disorders such as anxiety and stress has a long history. The purpose of the present study was to investigate the compensatory effects of hydroalcoholic extract of green tea on anxiety behaviors that are induced by noise stress in male Wistar rats. Methods: In this study, male Wis...