A study of multi-element/multi-path concentric shell structures to reduce noise and vibration

2014 ◽  
Vol 135 (4) ◽  
pp. 2386-2386
Author(s):  
Donald B. Bliss ◽  
David Raudales ◽  
Linda P. Franzoni
Keyword(s):  
Shell Structures ◽  
Noise And Vibration ◽  
Concentric Shell

Characterisation of the Humming-Type Noise and Vibration of the Automotive HVAC System

2019 ◽  
Vol 16 (2) ◽  
pp. 6634-6648
Author(s):  
A. Z. A. Mazlan ◽  
M. H. A. Satar ◽  
M. H. Hamdan ◽  
M. S. Md. Isa ◽  
S. Man ◽  
...  
Keyword(s):  
Vibration Characteristics ◽  
Operating Conditions ◽  
Hvac System ◽  
Frequency Range ◽  
Noise And Vibration ◽  
Power Steering ◽  
Pump Compressor

The automotive heating and ventilating air condition (HVAC) system, when vibrating, can generate various types of noises such as humming, hissing, clicking and air-rushes. These noises can be characterised to determine their root causes. In this study, the humming-type noise is taken into consideration whereby the noise and vibration characteristics are measured from various HVAC components such as power steering pump, compressor and air conditional pipe. Four types of measurement sensors were used in this study - tachometer for rpm tracking; accelerometer for the vibration microphone for the noise; and sound camera for the visualization measurement. Two types of operating conditions were taken into consideration - they were “idle” (850 rpm) and “running” (850-1400 rpm) conditions. A constant blower speed was applied for both conditions. The result shows that the humming noises can be determined at the frequency range of 300-350 Hz and 150-250 Hz for both idle and running conditions, respectively. The vibration of the power steering pump shows the worst acceleration of 1.8 m/s2 at the frequency range of 150-250 Hz, compared to the compressor and air conditional pipe. This result was validated with the 3D colour order and sound camera analyses, in which the humming noise colour mapping shows dominance in this frequency range.  

Noise and vibration: Mine workers’ exposure in Quebec underground mines

CIM Journal ◽  
2015 ◽  
Vol 6 (2) ◽  
pp. 111-117
Author(s):  
Marcel Laflamme ◽  
Pierre Marcotte ◽  
Jérôme Boutin ◽  
Sylvain Ouellette ◽  
Gilles LeBlanc
Keyword(s):  
Underground Mines ◽  
Noise And Vibration ◽  
Mine Workers

Preventing Noise and Vibration During the 60 Years of Activity of the Central Institute for Labour Protection - National Research Institute

2011 ◽  
Vol 36 (1) ◽  
pp. 161-171
Author(s):  
Wiktor Zawieska ◽  
Dariusz Pleban
Keyword(s):  
Working Environment ◽  
60Th Anniversary ◽  
National Research Institute ◽  
Noise And Vibration ◽  
Central Institute ◽  
Research Institute

Abstract In 2010, the Central Institute for Labour Protection - National Research Institute celebrated the 60th anniversary of its activity. Primary objectives of the Institute have been and continue to be the protection of employees against any hazards at work stations. Among the numerous hazards, vibroacoustic ones are becoming prevailing. Therefore, one can now dare to say that the 60 years of activity of the Central Institute for Labour Protection have also meant 60 years of preventing noise and vibration in the working environment. For those 60 years of activity, Central Institute for Labour Protection has been associated with outstanding acousticians and vibration specialists. The first chairperson of the Scientific Council of the Central Institute for Labour Protection was Professor Ignacy Malecki, one of the most outstanding Polish scientists. Chairpersons of the Council have also included Professor Adam Lipowczan and Professor Zbigniew Engel and the members of the Council have included Professor Stefan Ziemba and Professor Jerzy Sadowski.

State of hormonal regulation in experimental animals exposed to noise and vibration

2020 ◽  
pp. 680-681
Author(s):  
A. V. Lizarev ◽  
V. A. Pankov
Keyword(s):  
Blood Plasma ◽  
Hormonal Regulation ◽  
Adrenocorticotropic Hormone ◽  
Vibration Exposure ◽  
Noise And Vibration ◽  
Experimental Animals ◽  
In Blood Plasma

When exposed to noise and vibration in experimental animals there was a decrease in the content of threeiodinethyronine, thyroxin and adrenocorticotropic hormone in blood plasma after 15 and 30 days of experience. An increase in loads led to an increase in the level of threeiodinethyronine and thyroxin under vibration exposure and was normalized with noise. The content of adrenocorticotropic hormone leveled in both cases.

Main approaches to prevention of health disorders in workers in contact with physical factors

2020 ◽  
Vol 60 (11) ◽  
pp. 827-829
Author(s):  
Andrey V. Melentyev
Keyword(s):  
Cardiovascular Risk ◽  
Cardiovascular Diseases ◽  
Machine Building ◽  
Working Environment ◽  
Physical Factors ◽  
Noise And Vibration ◽  
Industrial Enterprises ◽  
Increased Risk ◽  
Health Disorders ◽  
Building Enterprises

Introduction. One of the leading causes of occupational health loss, especially in mining and machine-building enterprises, is the combined impact of industrial noise and vibration. The wide prevalence of cardiovascular diseases is one of the most important medical and social problems, due to persistent disability and high mortality, bringing prevention of health disorders to the first place as the basis for preserving labor longevity. The aim of study is to identify the main approaches aimed at preventing health problems in workers who come into contact with vibration and noise at mining and machine-building enterprises. Materials and methods. A survey and survey of 296 industrial workers was conducted. Group 1 (160 people) included men who were exposed to noise and vibration factors above the maximum permissible levels, group 2 consisted of 136 men who did not have direct contact with noise and vibration generating equipment. When conducting an in-depth laboratory and instrumental examination in a hospital setting, all workers additionally calculated the level of cardiovascular risk on the SCORE scale. Statistical analysis was performed using the software package "Statistica 6.0". Results. It is determined that the priority adverse factors of the working environment in production are noise and vibration. It has been shown that individuals who come into contact with these factors are more likely to detect violations of lipid metabolism and endothelial function, have a higher average heart rate and systolic blood pressure, and have an increased risk of developing cardiovascular diseases. Conclusions. Taking into account the obtained results of the proposed diagnostic approaches aimed at the prevention of health disorders among workers of industrial enterprises. If employees are found to have an increased cardiovascular risk, it is necessary to conduct a more in-depth examination and timely medical and preventive measures.

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