China
Africa
Explore chapters and articles related to this topic
Noise and vibration
Published in Stephen Battersby, Clay's Handbook of Environmental Health, 2023
Andrew Colthurst, Steve Fisher
Environmental noise is defined as unwanted or harmful outdoor sound created by human activities, including noise from road, rail, airports and from industrial sites. Major airports and non-major airports that may impact upon agglomerations are designated to undertake their own noise mapping and each publish the resultant noise action plan. A particular requirement of the Directive is that Member States have to ensure that the strategic noise maps are made available and disseminated to the public, and that all information is clear, comprehensible and a summary is provided setting out the most important points. Action planning is to be repeated every five years, based on the noise maps generated the previous year. There is a range of potential mitigation measures that may be appropriate to particular situations, depending on various factors such as source and receiver characteristics, local sensitivities such as visual appearance, and finally practicality and cost effectiveness.
Predicting Thermal Conductivity of Metallic Glasses and Their Nanocomposites
Published in Sumit Sharma, Metallic Glass–Based Nanocomposites, 2019
Wang et al. [55] investigated physical and mechanical properties of zirconium-based bulk metallic glass reinforced with carbon nanotube (CNT). Experimental results show that the compressive strength is high with high fracture strength. It was found that the density of the BMG composite reduces with the increasing volume concentration of CNT, but longitudinal and transverse acoustic velocities, Young’s modulus, bulk modulus, shear modulus, and hardness increase with the volume concentration of the CNT. It was noted that for 4% volume concentration of CNT reinforcement, relative changes in longitudinal acoustic velocity, transverse acoustic velocity, Young’s modulus, bulk modulus, and rigidity modulus were up to 11.11% , 6.39% , 11.21% , 23.91% , and 10.86% , respectively. These results indicate the strengthening ability of the composites with the increase of volume concentration of the CNT. It was also noted that the composites have excellent wave absorption ability with very high ultrasonic attenuation as the coefficient of attenuation was very sensitive to the volume concentration of the CNT and increased non-linearly with the volume concentration of the CNT. The ultrasonic attenuation and wave absorption properties built due to the scattering of crystalline ZrC phase mixed with CNT dispersed in the glass matrix, and the interface built between the glassy phase and CNT. These results indicate that this material can be efficiently used for shielding of noise and can play a major role to reduce the environmental noise pollution.
Principles of Noise Control
Published in Junbo Jia, Jeom Kee Paik, Engineering Dynamics and Vibrations, 2018
The noise control engineer must be adept at capturing critical data, understanding the physics of sound reduction, the physiology of hearing and hearing damage, and the psychology of those exposed to environmental noise. To those new to the field this may seem like an impossible challenge, but there has been much work done to support the noise control engineer in meeting these challenges. There is good information on the effects of noise exposure and on the potential reaction of people exposed to environmental noise. There is a significant amount of data on the noise emissions of machines or how to predict noise emissions based on operational conditions. Finally, there is a great deal of data and practical information on the application and effectiveness of noise controls. The key is to understand how to use this information properly and in an effective manner.
An automated magnetoencephalographic data cleaning algorithm
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Antonietta Sorriso, Pierpaolo Sorrentino, Rosaria Rucco, Laura Mandolesi, Giampaolo Ferraioli, Stefano Franceschini, Michele Ambrosanio, Fabio Baselice
The environmental noise is due to unavoidable sources such as trains, cars, portable phones, power lines, elevators, and so on. Several countermeasures can be adopted for limiting such a kind of noise. A magnetically shielded room, a chamber enveloped by layers of aluminum and mu-metal, can attenuate external fields by 100 dB and more (Kawakatsu 2003). The adoption of gradiometer sensors, i.e. two or more coils measuring the differential field, makes the system insensitive to homogeneous magnetic fields which are typical of far (noise) sources. Hence, only nearby signal sources are detected, i.e. those within the brain. Several MEG systems have some reference sensors outside the helmet with the aim of measuring the external noise in order to compensate for it during the data pre-processing. It has to be underlined that environmental noise is not limited to magnetic noise. Mechanical vibrations propagate to the helmet and produce modulation artifacts. Thus, the presence of nearby roads or of slamming doors can considerably degrade the recorded signals. A proper design of the floor, mainly in terms of damping materials, can mitigate this noise source.
Social inequality, noise pollution, and quality of life of slum dwellers in Pokhara, Nepal
Published in Archives of Environmental & Occupational Health, 2022
Eunhwa Choi, Tulsi Ram Bhandari, Niranjan Shrestha
Noise, or ‘unwanted sound’, is perceived as an environmental stressor and nuisance. However, there is sufficient scientific evidence linking population exposure to environmental noise to adverse health.1,2 Therefore, environmental noise is considered not only a nuisance but also a public health concern.2 Hearing impairment has been well documented as a direct consequence of environmental noise exposure. Non-auditory effects of noise include ischemic heart disease, sleep disturbance, cognitive impairment in children, and annoyance.1,2 At least 1 million healthy life years have been estimated to be lost each year owing to traffic-related noise in western European countries.2
Exploring nighttime road traffic noise: A comprehensive predictive surface for Toronto, Canada
Published in Journal of Occupational and Environmental Hygiene, 2018
Christopher Drudge, James Johnson, Elaina MacIntyre, Ye Li, Ray Copes, Stanley Ing, Steven Johnson, Sunil Varughese, Hong Chen
Noise is an important risk factor for chronic disease and an emerging global public health problem.[1–3] In addition to directly causing hearing loss, environmental noise is associated with indirect effects such as sleep disturbance,[4,5] depression,[6,7] and cardiometabolic disease.[8–11] Sleep disturbance is a widespread consequence of environmental noise in cities, as nighttime noise is ubiquitous in urban areas and a reduction in sleep quality and quantity occurs at relatively low noise levels.[12,13]