Comparison of noise reduction of earplugs between fit test and coal mine work and observed variability of real-time noise reduction in coal mine work

Work ◽  
2016 ◽  
Vol 55 (3) ◽  
pp. 531-538 ◽  
Author(s):  
Mingyu Wu ◽  
Steve E. Guffey ◽  
Brandon C. Takacs
Keyword(s):  
Noise Reduction ◽  
Real Time ◽  
Coal Mine

scholarly journals Review of Respirable Coal Mine Dust Characterization for Mass Concentration, Size Distribution and Chemical Composition

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 426
Author(s):  
Behrooz Abbasi ◽  
Xiaoliang Wang ◽  
Judith C. Chow ◽  
John G. Watson ◽  
Bijan Peik ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Particle Size ◽  
Real Time ◽  
Coal Mine ◽  
Energy Dispersive ◽  
Size Distributions ◽  
X Ray ◽  
Membrane Filters ◽  
Mine Dust ◽  
Mass Concentrations

Respirable coal mine dust (RCMD) exposure is associated with black lung and silicosis diseases in underground miners. Although only RCMD mass and silica concentrations are regulated, it is possible that particle size, surface area, and other chemical constituents also contribute to its adverse health effects. This review summarizes measurement technologies for RCMD mass concentrations, morphology, size distributions, and chemical compositions, with examples from published efforts where these methods have been applied. Some state-of-the-art technologies presented in this paper have not been certified as intrinsically safe, and caution should be exerted for their use in explosive environments. RCMD mass concentrations are most often obtained by filter sampling followed by gravimetric analysis, but recent requirements for real-time monitoring by continuous personal dust monitors (CPDM) enable quicker exposure risk assessments. Emerging low-cost photometers provide an opportunity for a wider deployment of real-time exposure assessment. Particle size distributions can be determined by microscopy, cascade impactors, aerodynamic spectrometers, optical particle counters, and electrical mobility analyzers, each with unique advantages and limitations. Different filter media are required to collect integrated samples over working shifts for comprehensive chemical analysis. Teflon membrane filters are used for mass by gravimetry, elements by energy dispersive X-ray fluorescence, rare-earth elements by inductively coupled plasma-mass spectrometry and mineralogy by X-ray diffraction. Quartz fiber filters are analyzed for organic, elemental, and brown carbon by thermal/optical methods and non-polar organics by thermal desorption-gas chromatography-mass spectrometry. Polycarbonate-membrane filters are analyzed for morphology and elements by scanning electron microscopy (SEM) with energy dispersive X-ray, and quartz content by Fourier-transform infrared spectroscopy and Raman spectroscopy.

scholarly journals Joint upsampling and noise reduction for real-time depth map enhancement

2014 ◽  
Author(s):  
Kazuki Matsumoto ◽  
Chiyoung Song ◽  
Francois de Sorbier ◽  
Hideo Saito
Keyword(s):  
Noise Reduction ◽  
Real Time ◽  
Depth Map

scholarly journals Development and Evaluation of Light-Weight Active Noise Cancellation Earphones

2018 ◽  
Vol 8 (7) ◽  
pp. 1178 ◽  
Author(s):  
Sen Kuo ◽  
Yi-Rou Chen ◽  
Cheng-Yuan Chang ◽  
Chien-Wen Lai
Keyword(s):  
Noise Reduction ◽  
Real Time ◽  
Random Noise ◽  
Active Noise Control ◽  
Noise Cancellation ◽  
Experimental Results ◽  
Path Model ◽  
Light Weight ◽  
Active Noise ◽  
Natural Sound

This paper presents the development of active noise control (ANC) for light-weight earphones, and proposes using music or natural sound to estimate the critical secondary path model instead of extra random noise. Three types of light-weight ANC earphones including in-ear, earbud, and clip phones are developed. Real-time experiments are conducted to evaluate their performance using the built-in microphone inside KEMAR’s ear and to compare with commercially-available ANC headphones and earphones. Experimental results show that the developed light-weight ANC earphones achieve higher noise reduction than the commercial ANC headphones and earphones, and the in-ear ANC earphone has the best noise reduction performance.

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