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Article
Publication date: 17 August 2021

Bin Zhou, Jin Ma, Hongyan Zhou, Xiaoliang Shi and Ahmed Mohamed Mahmoud Ibrahim

This paper aims to investigate the friction noise properties of M50 matrix curved microporous channel composites filled with solid lubricant Sn-Ag-Cu (MS).

Abstract

Purpose

This paper aims to investigate the friction noise properties of M50 matrix curved microporous channel composites filled with solid lubricant Sn-Ag-Cu (MS).

Design/methodology/approach

Pure M50 (MA) and MS are prepared by selective laser melting and vacuum-pressure infiltration technology. The tribological and friction noise properties of MA and MS are tested through dry sliding friction and then the influential mechanism of surface wear sate on friction noise is investigated by analyzing the variation law of noise signals and the worn surface characteristics of MS.

Findings

Experimental results show that the friction noise sound pressure level of MS is only 75.6 dB, and it mainly consists of low-frequency noise. The Sn-Ag-Cu improves the surface wear state, which reduces self-excited vibration of the interface caused by fluctuation of friction force, leading to the decrease of friction noise.

Originality/value

This investigation is meaningful to improve the tribological property and suppress the friction noise of M50 bearing steel.

Details

Industrial Lubrication and Tribology, vol. 73 no. 6
Type: Research Article
ISSN: 0036-8792

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Article
Publication date: 12 October 2021

Mekhala Kaluarachchi, K.G.A.S. Waidyasekara and Raufdeen Rameezdeen

Construction activities generate noise that is harmful to workers and the neighbouring community. Engineering control methods are often used for its control which are…

Abstract

Purpose

Construction activities generate noise that is harmful to workers and the neighbouring community. Engineering control methods are often used for its control which are expensive and limited in effectiveness. This study aims to investigate factors that affect employee behaviour and how it could be used by construction companies to manage noise pollution on sites.

Design/methodology/approach

Norm Activation Model (NAM) is used to investigate the relationship between attitudes and behaviour of site-based employees using a questionnaire survey administered in Colombo, Sri Lanka. The responses were analysed using structural equation modelling to discern behavioural patterns and how it differs between managers and workers.

Findings

The results showed that behaviour of site employees could be influenced when they are aware of the consequences of noise pollution and take responsibility for its control. Personal norm of an employee and company's environmental behaviour are found to influence the behaviour in a positive manner.

Practical implications

Construction companies should focus more on how to harness their employee's behaviour in order to reduce noise pollution on sites. Employees should be made aware of consequences of noise pollution and feel responsible for their actions through training, awareness campaigns, signage and so on.

Originality/value

This study contributes to the literature by building a theoretical model of employee noise control behaviour in construction organizations and empirically testing it among managers and workers. It compares the differences between these two groups which enhances one’s understanding of behavioural control methods when applied in a construction project setting. The study also evaluates the effects of company's environmental behaviour on employee behaviour.

Details

Built Environment Project and Asset Management, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2044-124X

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Article
Publication date: 29 May 2020

Anton V. Ubaychin, Tilekbek Abdirasul Uulu and Grigory Zhuk

This paper aims to describe a new microwave radiometer designed for sensing natural mediums to solve various applied scientific problems. The research findings enable to…

Abstract

Purpose

This paper aims to describe a new microwave radiometer designed for sensing natural mediums to solve various applied scientific problems. The research findings enable to make assertions about high efficiency of the described microwave radiometer being a part of mobile sensor systems with self-contained power supplies.

Design/methodology/approach

A new microwave radiometer is based on the modification of the null method. Modification of the null method has been implemented by using two reference noise generators. The first reference noise generator is passive and its implementation is based on the matched load. A low-noise amplifier is used as the second reference noise generator. The use of the low-noise amplifier as the reference noise generator is based on the noise wave generation effect at its input whereby the waves form low-temperature noise.

Findings

The use of the low-noise amplifier as the reference noise generator in the modified microwave radiometer has made it possible to simplify the device design at the system level while reducing the weight and power consumption and increasing sensitivity.

Originality/value

The novelty of the modified radiometer lies in the modification of the null method and the removal of high-temperature reference noise generators based on avalanche transit-time diodes. Further, the novelty lies in the invariance of measurement results toward changes in the receiver’s own noise and transmission factor while the design of the device has been simplified.

Details

Sensor Review, vol. 40 no. 3
Type: Research Article
ISSN: 0260-2288

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Article
Publication date: 10 September 2021

Junfeng Sun, Haitao Zhang, Guangyuan Wu, Zuoqiang Liu, Yuping Feng and Minghao Jia

In order to give full play to the function of noise reduction of asphalt pavement, it is necessary to understand its internal sound absorption mechanism. Therefore, the…

Abstract

Purpose

In order to give full play to the function of noise reduction of asphalt pavement, it is necessary to understand its internal sound absorption mechanism. Therefore, the purpose of this study is to establish a micro model of the pore structure of asphalt mixture with the help of finite element method (FEM), discuss the noise reduction mechanism of asphalt pavement from the micro perspective and analyze and evaluate the noise attenuation law of the pore structure.

Design/methodology/approach

The FEM was used to establish the microscopic model of the pore structure of asphalt mixture. Based on the principle of acoustics, the noise reduction characteristics of asphalt pavement were simulated. The influence of gradation and pore characteristics on the noise reduction performance of asphalt pavement was analyzed.

Findings

The results show that the open graded friction course-13 (OGFC-13) has excellent performance in noise reduction. The resonant sound absorption structure composed of its large porosity can effectively reduce the pavement noise. For asphalt concrete-13 (AC-13) and stone matrix asphalt-13 (SMA-13), the less resonant sound absorption structure makes them have poor sound absorption effect. In addition, the variation rules of noise transmission loss (TL) curve and sound absorption coefficient curve of three graded asphalt mixtures were obtained. At the same time, the peak noise reduction values of OGFC-13, AC-13 and SMA-13 were obtained, which were 650Hz, 1000Hz and 800Hz, respectively.

Originality/value

The results show that the simulation results can well reflect and express the experimental results. This will provide a reference for further exploring the sound absorption mechanism and its variation rule of porous asphalt pavement. It also has some positive significance for the application of low noise asphalt pavement.

Details

Multidiscipline Modeling in Materials and Structures, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1573-6105

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Article
Publication date: 1 December 2003

Y. Srinivasa Rao and M. Satyam

This paper deals with the investigations carried out on the variation of current noise (1/f noise) in polymer thick film resistors, when they are subjected to pulse…

Abstract

This paper deals with the investigations carried out on the variation of current noise (1/f noise) in polymer thick film resistors, when they are subjected to pulse voltage trimming. The current noise is measured in terms of noise index (micro volts of noise per volt of DC applied, in a decade of frequency) using Noise Meter Model 315 C manufactured by Quan‐Tech of New Jersey. It has been found that current noise decreases as the resistors are trimmed to lower values. An attempt has been made to explain the decrease in current noise with the trimming of resistors.

Details

Microelectronics International, vol. 20 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 1 April 1997

Alan D. Wallis

Suggests that before measurement of noise can be implemented all “non‐aircraft noises” must be eliminated. Sets out various approaches to the problem of airport noise: the…

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Abstract

Suggests that before measurement of noise can be implemented all “non‐aircraft noises” must be eliminated. Sets out various approaches to the problem of airport noise: the acoustic companies’ approach; the systems companies’ approach; systems costs; flight identification and correlation; and noise monitoring. Looks at international standards for noise monitoring and reports on the current noise monitoring terminal situation. Includes an Appendix on units of measure for noise.

Details

Aircraft Engineering and Aerospace Technology, vol. 69 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

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Article
Publication date: 27 April 2012

Paul Roelofsen

This article is a proposal and aims to be a first step to develop a method to evaluate and classify environmental noise, according to EN‐15251 and CR‐1752, in the built…

Abstract

Purpose

This article is a proposal and aims to be a first step to develop a method to evaluate and classify environmental noise, according to EN‐15251 and CR‐1752, in the built environment based on the percentage of dissatisfied related to the equivalent background noise level.

Design/methodology/approach

In the European guideline CR‐1752 and the standard EN‐15251 three categories of the indoor environment in buildings are prescribed (category A, B and C). In the recommendations, the limit whereby the percentage of dissatisfied should remain under varies in each category for both the thermal indoor environment and the air quality. The categories for noise and illumination criteria are not yet explicitly related to a percentage of dissatisfied.

Findings

Using the percentage of dissatisfied as the evaluation criterion, when related to the equivalent background noise, produces a more refined evaluation of comfort than an evaluation based on the percentage of seriously disturbed or the effects of sleep deprivation in relation to external noise. Furthermore, this corresponds to the European standards and recommendations concerning quality classification of the indoor environment, based on the percentage of dissatisfied.

Originality/value

Based on recent European undertakings concerning the development of categories for the indoor environment based on the percentage of dissatisfied, it is desirable to utilise these categories to noise aspects too, and to relate it to the equivalent background noise level.

Details

Journal of Facilities Management, vol. 10 no. 2
Type: Research Article
ISSN: 1472-5967

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Article
Publication date: 1 February 1967

F.B. Greatrex and R. Bridge

DURING the 1950s noise around airports increased steadily with increasing traffic and size of aircraft. With the introduction of heavy jet transports the very different…

Abstract

DURING the 1950s noise around airports increased steadily with increasing traffic and size of aircraft. With the introduction of heavy jet transports the very different quality of noise (compared to piston engines) highlighted the problem and the upward trend had to be halted. This led to a considerable increase in effort to investigate the noise of turbojet engines.

Details

Aircraft Engineering and Aerospace Technology, vol. 39 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 1 June 2004

A. Czyzewski and J. Kotus

A concept and an implementation of the multimedia computer system for the monitoring of environmental noise is presented in the paper. The system provides an extension to…

Abstract

A concept and an implementation of the multimedia computer system for the monitoring of environmental noise is presented in the paper. The system provides an extension to the Internet‐based system for testing hearing which was engineered and launched in 1999. A considerable portion of hearing diseases is caused by excessive industry, urban and traffic noise or any unwanted sounds occurring in everyday life. Consequently, it is expected that a reduction of hearing diseases occurrence will be achieved as a result of implementation of the solutions that have been developed within the project scope. The latest technological advances in information technology were used in the course of the project realisation. Consequently, it is shown in the paper that the presented solutions are based on some innovative ideas and inexpensive technical means for measuring noise and vibration allowing fast evaluation of its influence on the psychosomatic and the vegetative system. It is expected that implementation of the noise telemonitoring system covering whole country will contribute to rising awareness of society and authorities with regard of the influence of noise on health. Furthermore, it turns out to be an essential factor in the future improvement of the environmental noise conditions.

Details

Management of Environmental Quality: An International Journal, vol. 15 no. 3
Type: Research Article
ISSN: 1477-7835

Keywords

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Article
Publication date: 1 April 1997

John Hutchinson

Examines the problem of noise level of civil aircraft engines. Focuses on two aspects of aircraft fan noise: cabin noise and community noise. Outlines the FANPAC programme…

Abstract

Examines the problem of noise level of civil aircraft engines. Focuses on two aspects of aircraft fan noise: cabin noise and community noise. Outlines the FANPAC programme launched in 1992 to assess techniques to control fan noise and describes two of the most promising liner designs. Reports on the progress made and suggests a follow‐on programme to explore further areas.

Details

Aircraft Engineering and Aerospace Technology, vol. 69 no. 2
Type: Research Article
ISSN: 0002-2667

Keywords

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