scholarly journals Tackling Noise Pollution With Slow Sound

2021 ◽  
Vol 9 ◽  
Author(s):  
William J. Parnell ◽  
William D. Rowley ◽  
Naomi R. M. Curati
Keyword(s):  
Special Class ◽  
Noise Pollution ◽  
Sound Waves

Noise pollution can reduce the quality and even the length of our lives, causing around 12,000 early deaths in Europe each year. Devices called resonators can be used to reduce unwanted noise from engines and fans, by cancelling out sound waves. However, the sound waves of low-pitched noises are difficult to cancel because they are very big: sometimes as long as 17 m! To cancel such large sound waves would require an impractically large resonator. One solution to this problem is to make the resonator from a special class of material called a metamaterial. Metamaterials have specially designed structures that give them properties that are not found in ordinary materials. This article explains how we used mathematics to design a metamaterial that slows down sound waves. Slowing the sound allows us to use smaller resonators, so we can cancel lower-pitched noises than we can with ordinary materials.

scholarly journals Approach to design of distributed multi-agent system for processing sound information of the environment

2019 ◽  
pp. 47-53
Author(s):  
U. A. Vishniakou ◽  
B. H. Shaya
Keyword(s):  
Urban Space ◽  
Noise Pollution ◽  
Gaussian Mixture ◽  
Support Vector ◽  
Multi Agent System ◽  
Sound Waves ◽  
Agent System ◽  
Continuous Space ◽  
Wide Range ◽  
Multi Agent

The processes of measurement, recording and analysis of different sound levels are considered. The amplitude and effect of sound waves vary considerably in continuous space-time measurements. Modeling different types of sounds and their spatiotemporal effects becomes important for assessing the sound situation both in working spaces and in recreation areas. Developing a model that reflects the characteristics of sounds, their sources, and the rules that govern their distribution in different environments would help track sound variations and predict their future changes for spatiotemporal states. Similar works abroad are given, but they are of a private nature. There are many features that you can use to describe audio signals. We consider a wide range of objects to evaluate the effect of each object and select the appropriate set of objects to distinguish between classes. Two estimations of a sound situation are given: on the basis of short-term energy and average speed of change. Three different classification methods are investigated: KNearest neighbors, Gaussian mixture model and Support vector machine.Multi-agent system (M)AS characteristics are given, the classification, trends in the use of multi-agent intelligent technologies for information processing are presented. Authors propose the use of MAS for sound information (MASSI) monitoring. MFSSI structure includes many agents of sound transformation, analysis of information received from them and decision-making. MASSI can handle noise levels in the urban space and to help in the study of noise pollution in many areas.

scholarly journals Cryptococcus neoformans Virulence Attributes can be Modulated by Sound Stress

2021 ◽  
Vol 8 (4) ◽  
Author(s):  
Kellysson GB Mendes ◽  
◽  
Fabiana Brandao AS ◽  
Raul Alberto Laumann ◽  
Simoni Campos Dias ◽  
...  
Keyword(s):  
Cryptococcus Neoformans ◽  
Morphological Changes ◽  
Noise Pollution ◽  
Pathogenic Fungi ◽  
Slight Reduction ◽  
Sound Waves ◽  
Melanin Production ◽  
Viable Cells ◽  
Almost All ◽  
The Impact

Sound waves are a prime component making up the environment, and they are present in almost all niches on the planet. In times of increasing noise pollution, the effect of sound stress on humans, animals, and microorganisms is well known. However, the possibility of this kind of pressure in the environment, affecting pathogenic fungi, which live in the background as saprophytes, has not been explored. Fungi can develop attributes and become virulent due to adaptation to selective pressure or stress. In this context, our group has become interested in evaluating the impact of sound stress on the fungus Cryptococcus neoformans, a pathogen that has high phenotypic plasticity. C. neoformans strain H99 was chosen for all assays. The yeasts were cultivated at 30°C, exposed or not to the frequency of 8 kHz. We observed morphological changes in these cells, such as the expression of phenotype virulence attributes: capsule expansion and melanin production. We also analyzed the number of viable cells after exposure, and we observed the yeast’s susceptibility to antifungals. After the treatment with 8 kHz, the cells showed a significant increase in the capsule expansion, an acceleration of the melanin production, and a slight reduction in the number of viable cells. Finally, tests performed with the antifungals showed a decrease in inhibition halo on the plate test. Our results are innovative and suggest that stress caused by sound could incite increased virulence in this fungus.

scholarly journals Zaštita od buke - zvučne barijere

Sigurnost ◽  
2019 ◽  
Vol 61 (3) ◽  
pp. 217-226
Author(s):  
Sanja Grubeša ◽  
Antonio Petošić ◽  
Mia Suhanek ◽  
Ivan Đurek
Keyword(s):  
Prolonged Exposure ◽  
Negative Impact ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Negative Influence ◽  
Environmental Pollutant ◽  
Sound Waves ◽  
Noise Barriers ◽  
Advantages And Disadvantages ◽  
Different Types

SUMMARY: This paper deals with the issue of noise as an environmental pollutant, and furthermore it suggests possible solutions for this issue. Sound is a form of energy transmitted by sound waves. In general, sounds may be perceived as desirable or undesirable. Sounds which are considered undesirable and unwanted can be observed as noise, however the perception of sound in general is significantly subjective and individual. In particular, one person can perceive a certain sound as pleasant, whereas another could characterize it as annoying, unpleasant, and generally undesirable. This paper explains the term “noise” in detail, noise indicators as numerical values, and the ways noise can have a negative impact on people. Even today, noise pollution is often neglected compared to other environmental pollutions (i.e. water pollution, soil pollution, air pollution etc.). However, exposure to noise has an accumulative character. The consequences are noticeable after a prolonged exposure and can manifest themselves as bad mood, fatigue, insomnia, headache and loss of concentration, thereby having a direct influence on the quality of life. The focus of this paper is traffic noise and acoustical solutions which can reduce it. The dominant part of sound energy produced by traffic is in the middle-frequency range, which coincides with the range of maximum sensitivity of human hearing. When planning a new traffic route the negative influence of noise on people and the environment can be reduced by choosing the route which is remote from populated areas. In cases when the roads are fitted into the existing terrain and near populated areas, they can be equipped with protective noise barriers. The paper gives a detailed explanation on what noise barriers are, and an overview of different types of noise barriers that are currently in use. In addition, the advantages and disadvantages of different types of noise barriers are discussed.

scholarly journals Impacto de la contaminación acústica producida en el Aeropuerto Capitán FAP Guillermo Concha Iberico

2021 ◽  
Vol 2 (4) ◽  
pp. 5049-5067
Author(s):  
Shirley Tatiana Bustamante Vilchez De Tay ◽  
Karina Silvana Gutiérrez Valverde ◽  
Julio César Tay León ◽  
Vicente Segundo Ruiz Jacinto ◽  
Jannyna Reto Gómez ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Environmental Quality ◽  
Noise Pollution ◽  
National Standards ◽  
Sound Waves ◽  
Negative Effects ◽  
Calidad De Vida ◽  
Acoustic Impact

El propósito de la investigación se basó en la evaluación del impacto acústico causado por el tráfico aéreo de las aerolíneas de los vuelos comerciales que operan en el Aeropuerto Capitán FAP Guillermo Concha Iberico, ubicado en el Distrito de Castilla, Piura, Perú. La investigación consistió en analizar: (a) Los niveles de contaminación de ruido y (b) los efectos negativos que produce en la salud y calidad de vida de la población que habita en la cercanía del mismo y se delimitó en el Distrito de Castilla, en función a lo establecido por el D.S. N° 085-2003-PCM del Reglamento de Estándares Nacionales de Calidad Ambiental para Ruido (ECA’s), el cual regula los límites máximos permisibles de sonido; bajo un modelamiento de las zonas de tránsito de los aviones a la hora de aterrizaje y despegue, el cual entregó como resultado un mapa de contornos de ruido. De esta manera, fue posible identificar aquellas áreas afectadas por las ondas sonoras, producto del funcionamiento del aeropuerto. El modelo se realizó con la recopilación de información a través de datos in situ en lugares que abarcan la zona de desplazamiento de las aeronaves y el tiempo de evaluación fue el periodo de cinco meses comprendido entre octubre, noviembre y diciembre del 2017 y enero y febrero del 2018.   The purpose of the research was based on the evaluation of the acoustic impact caused by the air traffic of the airlines of the commercial flights operating at the Capitán FAP Guillermo Concha Iberico Airport, located in the District of Castilla, Piura, Peru. The investigation consisted in analyzing: (a) the levels of noise pollution and (b) the negative effects it has on the health and quality of life of the population living in the vicinity of it and was delimited in the District of Castilla, according to the provisions of the DS N ° 085-2003-PCM of the Regulation of National Standards of Environmental Quality for Noise (ECA's), which regulates the maximum permissible limits of sound; under a modeling of the zones of transit of the airplanes at the time of landing and takeoff, which gave as a result a map of noise contours. In this way, it was possible to identify those areas affected by the sound waves, as a result of the operation of the airport. The model was made with the collection of information through on-site data in places that cover the area of ​​displacement of aircraft and the time of evaluation was the five-month period between October, November and December 2017 and January and February of 2018.

scholarly journals Study on Sound Field Distribution Rule for Tank Structures of Large Oil-immersed Transformers

2021 ◽  
Vol 233 ◽  
pp. 01021
Author(s):  
Ma Yuchao ◽  
Mo Juan ◽  
Yu Jinshan ◽  
Li Xiang ◽  
Zheng Zhongyuan
Keyword(s):  
Power Systems ◽  
Field Distribution ◽  
Influence Factors ◽  
Sound Field ◽  
Noise Pollution ◽  
Sound Waves ◽  
Analysis Model ◽  
Term Operation ◽  
Distribution Rule ◽  
Propagation Rule

Large oil-immersed transformers are an important part of the transmission and distribution network in power systems. Power transformers are the main noise source of substations. Because of the uneven manufacturing process, aging equipment, long-term operation, and close distance from sensitive points, the problem of transformer noise pollution has become increasingly prominent. In this paper, the transmission and analysis model is established for transformer sound waves on the interface between insulating oil and tank body according to the sound wave propagation rule in complicated medium, and the simplified acoustic simulation model is constructed for large oil-immersed transformers by simulating the vibration noise of transformer core with monopole sound source, with which, the sound field distribution rule inside and outside the transformer tank structure is obtained, and finally, the influence factors for noise distribution are given. The results of the study provide control basis for reducing transformer noise.

An Intervention in a “Special” Class

1980 ◽  
Vol 9 (1) ◽  
pp. 99-103 ◽  
Author(s):  
Virginia Monroe ◽  
Lisa Ford
Keyword(s):  
Special Class

Lantern Slide Illustrating Sound Waves

1894 ◽  
Vol 70 (25) ◽  
pp. 395-395
Author(s):  
M. Hopkins
Keyword(s):  
Sound Waves ◽  
Lantern Slide

Effect of No-load and Load Condition on Transformer Sound

2018 ◽  
pp. 11-15
Author(s):  
Dr. Hitesh Paghadar
Keyword(s):  
Experimental Study ◽  
Power Transformer ◽  
Load Condition ◽  
Noise Pollution ◽  
Sound Level ◽  
Measurement Scale ◽  
Dominant Factor ◽  
Public Attention ◽  
Level Measurement ◽  
Human Ear

Increasing environment noise pollution is a matter of great concern and of late has been attracting public attention. Sound produces the minute oscillatory changes in air pressure and is audible to the human ear when in the frequency range of 20Hz to 20 kHz. The chief sources of audible sound are the magnetic circuit of transformer which produces sound due to magnetostriction phenomenon, vibration of windings, tank and other structural parts, and the noise produced by cooling equipments. This paper presents the validation for sound level measurement scale, why A-weighted scale is accepted for sound level measurement, experimental study carried out on 10MVA Power Transformer. Also presents the outcomes of comparison between No-Load sound & Load sound level measurement, experimental study carried out on different transformer like - 10MVA, 50MVA, 100MVA Power Transformer, to define the dominant factor of transformer sound generation.

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