scholarly journals Dietrich et al. Magnetic resonance noise measurements and signal-quantization effects at very low noise levels. Magn Reson Med 2008;60:1477-1487.

2009 ◽  
Vol 62 (1) ◽  
pp. 277-278
Author(s):  
Olaf Dietrich ◽  
José G. Raya ◽  
Maximilian F. Reiser
Keyword(s):  
Magnetic Resonance ◽  
Low Noise ◽  
Noise Levels ◽  
Signal Quantization ◽  
Noise Measurements

Magnetic resonance noise measurements and signal-quantization effects at very low noise levels

2008 ◽  
Vol 60 (6) ◽  
pp. 1477-1487 ◽  
Author(s):  
Olaf Dietrich ◽  
José G. Raya ◽  
Maximilian F. Reiser
Keyword(s):  
Magnetic Resonance ◽  
Low Noise ◽  
Noise Levels ◽  
Signal Quantization ◽  
Noise Measurements

scholarly journals A Note on Variation of the Acoustic Environment in a Quiet Residential Area in Kobe (Japan): Seasonal Changes in Noise Levels Including COVID-Related Variation

Urban Science ◽  
2020 ◽  
Vol 4 (4) ◽  
pp. 63
Author(s):  
Kimihiro Sakagami
Keyword(s):  
Noise Level ◽  
Residential Area ◽  
Low Noise ◽  
Noise Levels ◽  
State Of Emergency ◽  
Acoustic Environment ◽  
Target Values ◽  
Noise Measurements

This communication compares the previously reported results of the acoustic environment, mainly noise levels at a fixed point, in a quiet residential area in Kobe, Japan, under the declaration of the COVID-19 state of emergency in May 2020 with the results of two follow-up studies in the same area: subsequent follow-up noise measurements in June and July–August 2020, and the present results of measurements in September–October 2020. The results of the comparison among the above three measurements suggest that noise levels were lower during September-October 2020 than during the declaration of the state of emergency in May 2020. In the period from May to October 2020, the noise level was significantly higher in July and August of the same year due to the sound of cicadas, which are common in this area. This suggests that it is difficult to set the target values of the acoustic environment planning by referring to the low noise level at lockdown or similar measures in areas with large seasonal variations in acoustic environment. Although many case studies are necessary to obtain appropriate target values, one case study is presented in this communication to illustrate an example and discuss its difficulty.

scholarly journals Case Study in a Working Environment Highlighting the Divergence between Sound Level and Workers’ Perception towards Noise

2020 ◽  
Vol 17 (17) ◽  
pp. 6122
Author(s):  
Chun-Yip Hon ◽  
Illia Tchernikov ◽  
Craig Fairclough ◽  
Alberto Behar
Keyword(s):  
Noise Exposure ◽  
Health And Safety ◽  
Sound Level ◽  
Working Environment ◽  
Noise Levels ◽  
Hearing Conservation ◽  
Attitudes And Perceptions ◽  
Noise Measurements ◽  
Survey Responses ◽  
Excessive Noise

Excessive noise levels are a prevalent issue in food processing operations and, although there have been numerous studies on occupational noise, no single study has used a concurrent mixed-methods approach. Employing this study design allows for an understanding of the level of convergence (similarity) between measured noise levels and workers’ attitudes and perceptions towards noise. This, in turn, allows for the identification of potential challenges with respect to the implementation of hearing conservation efforts. In this study, spot noise measurements were collected using a sound level meter. One-on-one interviews were conducted with workers to determine attitudes and perceptions towards noise in their workplaces. Subsequently, the results of the noise measurements (quantitative data) were integrated with the survey responses (qualitative data) to identify convergence. The majority of the noise measurements were found to exceed 85 dBA—the criterion mandated by the local occupational health and safety legislation. Although all study participants felt that it was noisy in the workplace, a large proportion of respondents indicated that the noise was not bothersome. With workers’ perception being contradictory to the measured noise levels, it is a challenge to implement hearing conservation measures unless changes are made to raise the awareness of the risks associated with excessive noise exposure.

New Method to Determine the a-Si:H Pin Diode Series Resistance by Noise Measurements

1998 ◽  
Vol 507 ◽  
Author(s):  
F. Blecher ◽  
K. Seibel ◽  
M. Hillebrand ◽  
M. Böhm
Keyword(s):  
Series Resistance ◽  
Partial Information ◽  
Low Noise ◽  
Operating Conditions ◽  
New Method ◽  
Measuring System ◽  
Pin Diode ◽  
Noise Current ◽  
Current Voltage ◽  
Noise Measurements

ABSTRACTThe series resistance limits the linearity of photodiodes and decreases the efficiency of solar cells. It is usually determined from IV-measurements for moderate and high forward current density. This method, however, provides only partial information about Rs, since the series resistance depends on the operating point. An alternative method is based on noise measurements. System noise of the measuring system with a low-noise current-voltage converter has been investigated. A new method for extraction of photodiode series resistance from noise measurements is suggested. Noise measurements are carried out for a-Si:H pin diodes. The series resistance of an amorphous pin diode has been extracted for different operating conditions using the new measurement method.

Blow-Down Valve Noise and Interactions With Downstream Orifice Plates

2003 ◽  
Author(s):  
Denis G. Karczub ◽  
Fred W. Catron ◽  
Allen C. Fagerlund
Keyword(s):  
Noise Exposure ◽  
Control Valve ◽  
Low Noise ◽  
Noise Levels ◽  
Exposure Limits ◽  
Blow Down ◽  
Gas Processing ◽  
The Impact ◽  
Acoustic Fatigue ◽  
Infrequent Event

In a blow-down situation as might occur at a natural gas processing facility, noise levels are very high and significantly exceed the noise levels one would normally associate with a control valve. As the blow-down operation is an infrequent event, this may be permissible but requires consideration of the duration of these high noise levels to ensure that occupational noise exposure limits and acoustic fatigue limits are not exceeded. Tests of noise levels due to an 8-inch control valve in a 12-inch pipeline under blow-down conditions are compared here with noise level predictions based on the IEC standard. Consideration is also given to the impact of placing an orifice plate downstream of the control valve as is often done to reduce pressure drop across the valve in the expectation that control valve noise levels will be reduced. Simple orifice plates often installed by plant operators to achieve this goal are shown to have an adverse impact, and it is shown that a multi-hole diffuser or low-noise control valve should instead be used.

scholarly journals Low noise constant current source for bias dependent noise measurements

2011 ◽  
Vol 82 (1) ◽  
pp. 013906 ◽  
Author(s):  
D. Talukdar ◽  
R. K. Chakraborty ◽  
Suvendu Bose ◽  
K. K. Bardhan
Keyword(s):  
Current Source ◽  
Low Noise ◽  
Constant Current ◽  
Constant Current Source ◽  
Noise Measurements

A Discussion of Pod Drives and Their Application In the Pleasure Boat Market

2009 ◽  
Author(s):  
Christopher Swanhart
Keyword(s):  
North America ◽  
General Information ◽  
Low Noise ◽  
Noise Levels ◽  
Propulsion Systems ◽  
Fully Integrated ◽  
Operator Interface ◽  
Performance System ◽  
Hull Forms

Since being introduced to North America at the Miami Boat Show in 2005, Volvo Penta Inboard Performance System, or IPS has established itself as a leading propulsion choice among pleasure boat owners and builders. Other suppliers are following suit including the Cummins Mercruiser Zeus system. Pod propulsion offers benefits like increased efficiency, better performance, nimble handling, and low noise levels while allowing more people to successfully operate their vessel due to a friendly operator interface. Features of these commercial pod systems that also benefit builders include ease of installation and the integral underwater exhaust which helps to meet CE requirements, for both exhaust and noise levels. Both IPS and Zeus are fully integrated pod propulsion systems. Existing vessels can be retro-fitted with these systems while many new vessels are being designed specifically for IPS or Zeus. Donald L. Blount and Associates provides consulting in regards to IPS integration with existing and new designs and has also been involved with designs employing the Zeus system. The first portion of this paper discusses pod drives, particularly IPS itself. (Because the author has substantially more experience and background with IPS, much of the information herein is IPS specific). General information on IPS and Zeus is offered as well as some operational specifics. The paper then focuses on the application of pod drives in existing and new vessel designs. The discussion includes how hull forms can be evaluated for use with pod drives. A look at the integration of pod systems into various types of pleasure boats (cruiser, day boat, fishing yacht, etc) is also covered including the challenges which exist for each specific vessel type.

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