ACOUSTIC INTENSIFICATION OF PROCESSES IN THE PLASMA OF THE GLOW DISCHARGE FOR TECHNOLOGICAL PROCESSES

In order to technological use in the preparation and application of plasma coatings, the mutual influence of acoustic impact on low-temperature plasma was conducted, the experimental methodology and the results of the study in the pipe at the resonant excitation frequency are given. The nonlinearity of sound oscillations was found and their amplification by increasing the pressure, which can be used to intensify the processes of plasma coatings.

Noise Generation and Acoustic Impact of Free Surface Hydropower Machines: Focus on Water Wheels and Emerging Challenges

The noise generated by free surface hydropower machines, e.g., water wheels, has led to complaints and to restrictions in their operation in urban areas. This problem generally occurs when water wheels are not well designed and are installed without expertise. Despite the relevance of the problem, and the growing interest in the use of water wheels at existing low head barriers, the acoustic impact of water wheels has not yet been properly addressed by the scientific community. Therefore, in this manuscript, the importance of the problem and the related scientific challenges are discussed, supported by case studies and theoretical considerations. A literature review on the topic is carried out, although little information is available in the scientific domain. The aim of this work is to increase the awareness on this problem, in order to stimulate future research and to suggest useful guidelines for future water wheel projects, thereby increasing the water wheel potential and reducing noise disturbance for people.

Acoustic Impact of Hybrid-Electric DEP Aircraft Configuration at Airport Level

The Italian research project PROSIB (PROpulsione e Sistemi IBridi per velivoli ad ala fissa e rotante), is a 30-month initiative funded by the Italian Ministry of University and Scientific Research (MIUR) and coordinated by the Leonardo company. The project is aimed to investigate configurations for regional aircraft and rotary wing platforms and architectures for propulsion systems, and is dedicated to the identification of the best strategy for their use, given different on-board energy sources. The reduced environmental impact is the key for the success of the new hybrid/electric aircraft configurations. This not only considers the chemical pollution introduced in the atmosphere, but also the noise produced on the surrounding area of airports. The present paper describes the acoustic impact assessment resulting from the inclusion of new propulsion technologies and new configurations of regional aircraft (ATR42 pax) in a reference airport area.

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

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.

THE USE OF ACOUSTIC WAVES TO SUPPRESS THE COMBUSTION PROCESS IN THE FIRE SEAT

Іn this article, the foundations of the formation of the acoustic method of impact on the combustion center have been considered. The relationship between the parameters of the acoustic impact on the source of an emergency arising from a fire, depending on the burning substance has been established. Separate proposals on the parameters of acoustic impact (power, frequency, pulse shape) and design solutions for acoustic systems for suppressing the combustion process in the fire source at the initial stage of the development of an emergency have been developed. Key words: acoustic method, acoustic impact, combustion process, emergency, acoustic lens.

A Review on Acoustic and Skid Resistance Solutions for Road Pavements

As cities grow in size, traffic also increases, thus making the population more exposed to road noise and traffic accidents. It is therefore important to study and understand which properties of the pavement influence its acoustic impact and skid resistance performance. The pavement texture plays a major role in generating noise and friction, and it can be engineered in order to control both of them at the same time. The phenomena regulating skid resistance are well understood today. The same applies for noise generation and propagation; the literature contains methods of designing the pavement surface layer to achieve consistent results. Several types of solutions can be found for asphalt mixtures, most of them derived from decades of studies and research. They use different approaches to be effective for noise and friction, but all have in common the control of the surface’s macro and microtexture. Finally, some considerations are made regarding novel paving solutions with artificial aggregates instead of natural ones to address noise and skid resistance.

Acoustic waste water clarification practices

The article covers the problems of reagent-free clarification of circulating and waste waters of enterprises with their production sites located in valleys of spawning rivers in the environmentally-sensitive northern territories. It is shown that horizontal sumps, widely used at mining enterprises due to their low construction and operation costs, fail to ensure the production and environmental indicators required in the current conditions. The article analyses the results of 20 years of application in the Russian Federation and the countries of the Asia-Pacific region of the complex acoustic method (CAM), based on the mechanisms of coagulation of fine particles, forced sedimentation of initial and coagulated particles, as well as sludge thickening and dewatering. The advantages and limitations are shown for the CAM method, developed by the author of the article and based on the principles of: complexity, with the use of the laws of linear and nonlinear acoustics; acoustic impact on the water system for the purpose of acoustic degassing of water; acoustic coagulation of fine suspended solids (and subsequent gravity sedimentation of the newly formed aggregates); acoustic (forced) sedimentation of the original and previously acoustically coagulated suspended solids; acoustic thickening of sludge in sumps and acoustic dewater ing of sludge at depositing sites with drainage systems; the cascade (boundary) nature of acoustic impacts on the water system in the main water catchers, sumps, etc. The specific behavior of processes under a complex acoustic impact ensures their high productivity and low power consumption values (unattainable by any other methods) and the required environmental safety in the special conditions of the Far North and the Far East.