scholarly journals ACOUSTIC NOISE POLLUTION FROM MARINE INDUSTRIAL ACTIVITIES: EXPOSURE AND IMPACTS

2018 ◽  
pp. 148-161 ◽  
Author(s):  
Halit Kuşku ◽  
Murat Yiğit ◽  
Sebahattin Ergün ◽  
Ümüt Yiğit ◽  
Nic Taylor
Keyword(s):  
Acoustic Noise ◽  
Noise Pollution ◽  
Industrial Activities

Experimental Study of Aerodynamic Noise From the Trailing Edge and Leading Edge of Blades in a Coaxial-Double Shaft Fan

2013 ◽  
Author(s):  
Jafar Madadnia ◽  
Mustafa Shekeb ◽  
Thimantha Ulluwishewa
Keyword(s):  
Wind Turbines ◽  
Acoustic Noise ◽  
Residential Building ◽  
Leading Edge ◽  
Noise Pollution ◽  
Aerodynamic Noise ◽  
Trailing Edge ◽  
Double Row ◽  
Positive Effects ◽  
Spacing Variation

Proactive acoustic noise control technologies in wind turbines and blowers have in recent years been the focus of intensive research to integrate wind turbines in residential building and to address public concerns on noise pollution. However efforts to understand the mechanics has been inconclusive, mainly due to the complexity and commercial confidentiality of the topic. The paper reports on the experimental investigation on two methods in controlling aerodynamic noise. A counter-rotating-double-row-turbine with variable gap/spacing (s) was designed, built and tested. Serrations were designed and attached on the leading edge and the trailing edge of the blades to proactively control aerodynamic noise. The model was operated in fan-mode and air velocity, shaft-revolution; electric-fan-power, acoustic noise amplitude (dB) and Centre frequency (CF in Hz) were measured for a number of spacing and serrations. Coefficients of Performance (COP), dB, CF were plotted against tip speed (TS). It was noticed that: • The double-shaft-fan has operated quieter than the single shaft fan especially as TS decreases. Acoustic noise (dB) dropped 20% at TS = 4m/s to less than 2% at TS = 10m/s. Efficiency and CF increased in the double-shaft fan as TS increased. Spacing variation between blade-rows had insignificant effect on the dB, Cf, and efficiency. • Serrations on single-shaft fan have also reduced dB (up to 10%), increased efficiency and CF with more positive effects with the serrations on the leading edge than the trailing edge. Serrations are more effective at higher TS range. • Serrations on a double-shaft fan with an optimum spacing, reduced acoustic noise (dB) only allow speeds [at TS <4m/s]. However minor improvement was noticed in efficiency or noise frequency.

scholarly journals A Digital Signal Processor Based Acoustic Sensor for Outdoor Noise Monitoring in Smart Cities

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 605 ◽  
Author(s):  
Juan Manuel López ◽  
Jesús Alonso ◽  
César Asensio ◽  
Ignacio Pavón ◽  
Luis Gascó ◽  
...  
Keyword(s):  
Acoustic Noise ◽  
Smart Cities ◽  
Monitoring Network ◽  
Noise Pollution ◽  
Sound Level ◽  
Noise Measurement ◽  
Acoustic Sensor ◽  
Measurement Instruments ◽  
Frequency Weighting

Presently, large cities have significant problems with noise pollution due to human activity. Transportation, economic activities, and leisure activities have an important impact on noise pollution. Acoustic noise monitoring must be done with equipment of high quality. Thus, long-term noise monitoring is a high-cost activity for administrations. For this reason, new alternative technological solutions are being used to reduce the costs of measurement instruments. This article presents a design for a versatile electronic device to measure outdoor noise. This device has been designed according to the technical standards for this type of instrument, which impose strict requirements on both the design and the quality of the device’s measurements. This instrument has been designed under the original equipment manufacturer (OEM) concept, so the microphone–electronics set can be used as a sensor that can be connected to any microprocessor-based device, and therefore can be easily attached to a monitoring network. To validate the instrument’s design, the device has been tested following the regulations of the calibration laboratories for sound level meters (SLM). These tests allowed us to evaluate the behavior of the electronics and the microphone, obtaining different results for these two elements. The results show that the electronics and algorithms implemented fully fit within the requirements of type 1 noise measurement instruments. However, the use of an electret microphone reduces the technical features of the designed instrument, which can only fully fit the requirements of type 2 noise measurement instruments. This situation shows that the microphone is a key element in this kind of instrument and an important element in the overall price. To test the instrument’s quality and show how it can be used for monitoring noise in smart wireless acoustic sensor networks, the designed equipment was connected to a commercial microprocessor board and inserted into the infrastructure of an existing outdoor monitoring network. This allowed us to deploy a low-cost sub-network in the city of Málaga (Spain) to analyze the noise of conflict areas due to high levels of leisure noise. The results obtained with this equipment are also shown. It has been verified that this equipment meets the similar requirements to those obtained for type 2 instruments for measuring outdoor noise. The designed equipment is a two-channel instrument, that simultaneously measures, in real time, 86 sound noise parameters for each channel, such as the equivalent continuous sound level (Leq) (with Z, C, and A frequency weighting), the peak level (with Z, C, and A frequency weighting), the maximum and minimum levels (with Z, C, and A frequency weighting), and the impulse, fast, and slow time weighting; seven percentiles (1%, 5%, 10%, 50%, 90%, 95%, and 99%); as well as continuous equivalent sound pressure levels in the one-third octave and octave frequency bands.

scholarly journals Identification and analysis of noise sources in the Noor-Abad gas compressor station, Iran

2015 ◽  
Vol 4 (1) ◽  
pp. 196
Author(s):  
Nader Mohammadi ◽  
Kami Mohammadi
Keyword(s):  
Sound Pressure Level ◽  
Sound Pressure ◽  
Acoustic Noise ◽  
Noise Pollution ◽  
Residential Area ◽  
Pressure Level ◽  
Compressor Station ◽  
Noise Condition ◽  
Noise Sources ◽  
Noise Map

The objective of this study is to identify the sources of acoustic noise (noise pollution) in the Noor-Abad gas compressor station and then to prioritize the station equipment based on noise pollution. First, the key locations inside the station as well as in the surrounding residential area, aka the study area, are determined for the measurement of sound pressure level. Then, the sound pressure level is measured at those points, and the related noise map is produced. Based on the noise map, the noise condition in the study area is evaluated by comparing the measured acoustic parameters with allowable standard values. Dangerous regions and critical points are thus identified. The major noise sources consist of main blowdown, units’ blowdowns, scrubbers, and turbo-compressors. The sound pressure level of main blowdown is measured at two intervals from its position: 80 m inside the station and 600 m outside the station (at the edge of the surrounding residential area). Also, the sound pressure level for a unit blowdown and a scrubber is measured at respectively 25 m and 40 m from their positions. Finally, the station equipment is prioritized based on noise pollution. The analysis of measurement results showed that the main noise sources are, respectively, the station main blowdown, units’ scrubbers, units’ blowdowns, turbo-compressors, and gas pipelines.

scholarly journals Toward acoustic noise type detection based on QQ plot statistics

2017 ◽  
Vol 30 (4) ◽  
pp. 571-584 ◽  
Author(s):  
Sanja Vujnovic ◽  
Aleksandra Marjanovic ◽  
Zeljko Djurovic ◽  
Predrag Tadic ◽  
Goran Kvascev
Keyword(s):  
State Estimation ◽  
Acoustic Signal ◽  
Acoustic Noise ◽  
Thermal Power ◽  
Noise Pollution ◽  
Detection Algorithm ◽  
Noise Detection ◽  
Statistical Parameters ◽  
Industrial Environment ◽  
Stochastic Signal

Fault detection and state estimation using acoustic signals is a procedure highly affected by ambient noise. This is particularly pronounced in an industrial environment where noise pollution is especially strong. In this paper a noise detection algorithm is proposed and implemented. This algorithm can identify the times in which the recorded acoustic signal is influenced by different types of noise in the form of unwanted impulse disturbance or speech contamination. The algorithm compares statistical parameters of the recordings by generating a series of QQ plots and then using an appropriate stochastic signal analysis tools like hypothesis testing. The main purpose of this algorithm is to eliminate noisy signals and to collect a set of noise free recordings which can then be used for state estimation. The application of these techniques in a real industrial environment is extremely complex because sound contamination usually tends to be intense and nonstationary. The solution described in this paper has been tested on a specific problem of acoustic signal isolation and noise detection of a coal grinding fan mill in thermal power plant in the presence of intense contaminating sound disturbances, mainly impulse disturbance and speech contamination.

Assessment of Traffic Noise Pollution due to Road Traffic

2021 ◽  
Vol 110 ◽  
pp. 87-97
Author(s):  
Gabriela Demian ◽  
Luminița Grecu ◽  
Mihai Demian
Keyword(s):  
Noise Level ◽  
Road Traffic ◽  
Traffic Noise ◽  
Noise Pollution ◽  
Road Transport ◽  
Time Of Day ◽  
Regression Method ◽  
Noise Sources ◽  
Industrial Activities ◽  
Level Measurement

The paper presents aspects related to noise pollution due to road traffic in Drobeta Turnu Severin. The main noise sources in Drobeta Turnu Severin are: road transport, railway and industrial activities. Based on the noise level measurement performed to assess the traffic noise over a period of 7 years, namely between 2013 and 2019, on an important road traffic artery in the mentioned city, predictions for its level over the next three years are made, correlating it with the number of cars that are supposed to cross the artery. For this study a road where the equivalent noise level exceeded the limit almost every year, was chosen. For obtaining the correlation between our data we have used the regression method. The noise level depends on the time of day in which the measurements were made but also on the season. Another correlation, between the equivalent noise level, and the number and type of cars was made, for a winter day in 2020, on another important artery, in order to see how much influence these factors have, on the noise level.

scholarly journals Alzheimers Disease-Like Neuropathology Following Exposure to Ambient Noise

2021 ◽  
Vol 2 (11) ◽  
pp. 1159-1162
Author(s):  
Mojtaba Ehsanifar ◽  
Zeinab Montazeri ◽  
Mehravar Rafati
Keyword(s):  
Public Health ◽  
Health Care ◽  
Ambient Noise ◽  
Noise Exposure ◽  
Noise Pollution ◽  
Occupational Noise ◽  
Global Knowledge ◽  
Industrial Activities ◽  
The Public ◽  
Lack Of Information

Many factors play a role in the risk of dementia, including the environment. Widespread and significant worldwide exposure to noise, the severity of related health consequences, and the limited tools available to the public to protect themselves strongly support the WHO's argument that 'noise pollution is not only an environmental nuisance but also a threat to public health'. Exposures to noise from industrial activities, airport noise, or occupational noise are very important. One of the limitations of such studies is the lack of information about lifestyle habits that can play a key role in a person's risk of dementia. This review suggests that people with more exposure to ambient noise are at higher risk of Alzheimer’s Disease (AD) and dementia than other people and we examined how chronic noise exposure causes neuropathology such as AD and how it relates to ApoE4 activation. Further studies are essential to expanding global knowledge about the harmful health effects and costs of health care due to noise pollution.

Easy and effective acoustic noise protection in neonatal MRI

2006 ◽  
Vol 210 (S 1) ◽  
Author(s):  
M Lundh ◽  
A Nordell ◽  
J Bengtsson ◽  
Z Nagy ◽  
S Horsch ◽  
...  
Keyword(s):  
Acoustic Noise ◽  
Neonatal Mri

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.

Pengaruh bising lalu lintas terhadap penurunan fungsi pendengaran pada juru parkir di kota Denpasar

2013 ◽  
Vol 40 (2) ◽  
Author(s):  
Ni Ketut Susilawati ◽  
Wayan Sudana ◽  
Eka Putra Setiawan
Keyword(s):  
Hearing Impairment ◽  
Noise Exposure ◽  
Traffic Noise ◽  
Hearing Threshold ◽  
Noise Pollution ◽  
Simple Random Sampling ◽  
Cross Sectional Study ◽  
Control Group ◽  
Cross Sectional ◽  
Hearing Function

Background: Noise pollution or noise is an unwanted sound which is disturbing to human beings.However small or soft the sound, if it is undesirable it is considered as noise. Noise induced hearingloss is a sensorineural hearing loss that is commonly encountered second to presbycusis. Purpose: Toknow the effect of traffic noise exposure on hearing impairment to the employees of the Parking DistrictCompany of the Denpasar city and to improve diagnostic detection on hearing impairment caused bynoise. Method: A cross sectional study was conducted at the Parking District Company office. Thepopulations of this study were the employees of the Parking District Company. Samples of this study were the employees who were exposed to traffic noise and control samples were an employee who was unexposed. Samples were selected by simple random sampling. Results: From 40 parking attendants,27 persons (67.5%) aged above 35 years old. The parking attendants who had been working for ten to fifteen years were 36 persons (90%) and no history using ear protection when working. Seven persons(17.5%) had referred DPOAE upon examination with increase hearing threshold on audiogram result.In this study the parking attendants who had hearing deficit induced by noise were 7 persons (17.5%)and only one person (2.5%) in control group. There was a statistically significant effect of traffic noiseto hearing function deficit (p<0.05). Conclusion: Traffic noise has effect in hearing function deficit onthe parking attendants.ORLI Vol. 40 No. 2 Tahun 2010Key words: NIHL, parking attendant, audiometry, DPOAE.

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