APPLICATION OF PHOTOMETRY IN DETERMINING THE DUST MASS CONCENTRATION OF HARDWOODS

Given the carcinogenicity of hardwood dust, the aim of this study was to determine the effectiveness of the photometric method for different types of woodworking machines and its application in determining the mass concentration of inhalable dust for raw and dry hardwoods. In addition to the optical part of the device, the input part of the measuring device contains the Institute of Occupational Medicine (IOM) inhalable dust filter holder. This correlation of gravimetric and photometric methods in determining the dust mass concentration showed that photometry underestimates the mass concentration measured gravimetrically. The results of this study recommend the application of a correction factor 2 for a timber band saw and a correction factor 3 for circular saws in determining the mass concentration of hardwood dust by the photometric method. It was showed that photometry can be used if the correction factor of the optical device has been previously tested for specific wood processing place.

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Profiling Dust Mass Concentration in Northwest China Using a Joint Lidar and Sun-photometer Setting

Remote Sensing ◽

10.3390/rs13061099 ◽

2021 ◽

Vol 13 (6) ◽

pp. 1099

Author(s):

Tianhe Wang ◽

Ying Han ◽

Wenli Hua ◽

Jingyi Tang ◽

Jianping Huang ◽

...

Keyword(s):

Mass Concentration ◽

Field Experiments ◽

Negative Relationship ◽

Northwest China ◽

Dust Particles ◽

Mass Loading ◽

Average Mass ◽

Dust Mass ◽

Dust Loading ◽

Sun Photometer

The satellite-based estimation of the dust mass concentration (DMC) is essential for accurately evaluating the global biogeochemical cycle of the dust aerosols. As for the uncertainties in estimating DMC caused by mixing dust and pollutants and assuming a fixed value for the mass extinction efficiency (MEE), a classic lidar-photometer method is employed to identify and separate the dust from pollutants, obtain the dust MEE, and evaluate the effect of the above uncertainties, during five dust field experiments in Northwest China. Our results show that this method is effective for continental aerosol mixtures consisting of dust and pollutants. It is also seen that the dust loading mainly occurred in the free troposphere (< 6 km), with the average mass loading of 905 ± 635 µg m−2 trapped in the planetary boundary layer. The dust MEE ranges from 0.30 to 0.60 m2 g−1 and has a significantly negative relationship with the size of dust particles. With the assumption of the dust MEE of 0.37 (0.60) m2 g−1, the DMC is shown to be overestimated (underestimated) by 20–40% (15–30%). In other words, our results suggest that the change of MEE with the size of dust particles should be considered in the estimation of DMC.

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Influence of wood properties and technological parameters of processing on cutting power in milling of thermally modified beechwood

Glasnik Sumarskog fakulteta ◽

10.2298/gsf1104109m ◽

2011 ◽

pp. 109-124

Author(s):

Marija Mandic ◽

Nebojsa Todorovic ◽

Ranko Popadic ◽

Gradimir Danon

Keyword(s):

Beech Wood ◽

Untreated Wood ◽

Treatment Temperature ◽

Modulus Of Rupture ◽

Dry Density ◽

Technological Parameters ◽

Cross Sectional ◽

Measuring Device ◽

Cutting Power ◽

Wood Processing

The paper presents results of influence of thermal modification on cutting power required for milling wood processing. The experiment was conducted for the different treatment temperatures (170?C, 190?C and 210?C) and different technological parameters of processing (feed and cutting depth). Cutting powers during milling were measured on four groups of beech wood samples, dimensions 35?16?400 mm, separately for heartwood and sapwood. The following mechanical and physical properties of the processed samples were tested: bending properties (modulus of rupture and modulus of elasticity), cross-sectional and tangential hardness, and air-dry density. The measuring device used for measuring, monitoring and displaying cutting power was developed at the Wood Machining Centre at the Faculty of Forestry in Belgrade. The results point out the differences in the powers required for processing heat-treated wood compared to untreated wood. The analysis shows that with the increase in treatment temperature, the required cutting powers decrease.

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Investigating the size, shape and surface roughness dependence of polarization lidars with light-scattering computations on real mineral dust particles: Application to dust particles' external mixtures and dust mass concentration retrievals

Atmospheric Research ◽

10.1016/j.atmosres.2017.11.027 ◽

2018 ◽

Vol 203 ◽

pp. 44-61 ◽

Cited By ~ 8

Author(s):

Tahar Mehri ◽

Osku Kemppinen ◽

Grégory David ◽

Hannakaisa Lindqvist ◽

Jani Tyynelä ◽

...

Keyword(s):

Surface Roughness ◽

Light Scattering ◽

Mass Concentration ◽

Mineral Dust ◽

Dust Particles ◽

Dust Mass

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Uncertainty of Dust Mass Concentration Measurement

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.611.511 ◽

2014 ◽

Vol 611 ◽

pp. 511-518

Author(s):

Miroslav Dovica ◽

Vladislav Maxim ◽

Michal Kelemen ◽

Tatiana Kelemenová ◽

Ivan Virgala ◽

...

Keyword(s):

Light Scattering ◽

Mass Concentration ◽

Concentration Measurement ◽

Working Environment ◽

Respirable Dust ◽

Respirable Fraction ◽

Dust Mass ◽

Dust Fraction

Paper deals with dust mass concentration measurement in working environment. The measurement is focused to respirable dust fraction, which is dangerous for people. Light scattering principle of dust mass concentration measurement is used for this purpose. Also cyclone as mechanical way of separation of respirable fraction can be used for this purpose. Next problem is determination of uncertainty of this measurement.

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Field Comparison of TSI DustTrak versus TEOM in Two Poultry Houses

Transactions of the ASABE ◽

10.13031/trans.12442 ◽

2018 ◽

Vol 61 (2) ◽

pp. 653-660

Author(s):

Xufei Yang ◽

Chen Zhang ◽

Hong Li

Keyword(s):

Light Scattering ◽

Correction Factor ◽

Mass Concentration ◽

Field Performance ◽

Mie Scattering ◽

Correction Factors ◽

Poultry Houses ◽

Equivalent Method ◽

Tapered Element Oscillating Microbalance ◽

Broiler House

Abstract. The TSI DustTrak monitor has been used for particulate matter (PM) monitoring at various animal facilities. The instrument determines PM concentrations based on the principle of light scattering. Several assumptions (e.g., particle size, refractive index, and density) are imposed during the calibration process; however, they may not apply to PM emanating from agricultural settings. In this study, PM10 monitoring was conducted at a broiler house and a layer breeding house with four collocated instruments: three DustTrak monitors and one tapered element oscillating microbalance (TEOM). Being a federal equivalent method (FEM) for PM10 monitoring, TEOM was selected here as a transfer standard for assessing the field performance of DustTrak. Results revealed a good linearity between DustTrak and TEOM PM10 readings (R2 =0.92 and 0.85 in the broiler and layer breeding houses, respectively). However, DustTrak significantly underestimated PM10 concentrations in both houses. To correct for the monitoring bias by DustTrak, an average correction factor was derived from correlation analysis that characterized the ratio of DustTrak’s PM10 response to TEOM’s. The factor was calculated as 0.267 for the broiler house and 0.244 for the layer breeding house. Mie scattering simulation was performed to further verify the derived correction factors. A factor of 0.204 was estimated from the simulation, and it accorded well with experimental results. A dependence of the correction factor on PM10 concentration was noted in both poultry houses, indicating the feasibility of developing a concentration-dependent correction factor for future monitoring efforts. Such a relationship could also be explained by Mie scattering. This study is expected to facilitate a better understanding of the limitations and perspectives of the TSI DustTrak and other light scattering PM monitors for agricultural air quality research. Keywords: DustTrak, Mass concentration, Mie scattering, PM10, Poultry, TEOM.

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Retrieval of Dust Properties From Spectral Snow Reflectance Measurements

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.644551 ◽

2021 ◽

Vol 9 ◽

Author(s):

Alexander Kokhanovsky ◽

Biagio Di Mauro ◽

Roberto Garzonio ◽

Roberto Colombo

Keyword(s):

Grain Size ◽

Mass Concentration ◽

Diffuse Reflectance ◽

Near Infrared ◽

Spectroscopy Data ◽

Field Spectroscopy ◽

Dust Mass ◽

The Alps ◽

Simplified Algorithm ◽

Reflectance Measurements

In this paper, we present a simplified algorithm to retrieve snow grain size, dust mass absorption coefficient and dust mass concentration from spectral diffuse reflectance measurements at three wavelengths located in the visible and near infrared. The theoretical model is then compared with field spectroscopy data collected in different days from an automated spectrometer in the Alps.

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Researches on the numerical simulation of the dust pollution characteristics and the optimal dust suppression wind-speed on fully mechanised caving face

Energy Exploration & Exploitation ◽

10.1177/01445987211055807 ◽

2021 ◽

pp. 014459872110558

Author(s):

Jinming Mo ◽

Wei Ma

Keyword(s):

Numerical Simulation ◽

Wind Speed ◽

Wind Velocity ◽

Mass Concentration ◽

Dust Control ◽

Dust Pollution ◽

Dust Suppression ◽

Working Face ◽

Dust Mass ◽

Wind Velocities

Dust removal by ventilation is a commonly used dust control strategy. This study analyses the characteristics of airflow transport and dust pollution on a fully mechanised top-coal caving face at different inlet wind velocities by using a numerical simulation experiment, and the best wind velocity for dust suppression is obtained. When the inlet wind velocity fluctuates in the range of 0.5 to 3.0 m/s, the overall dust mass concentration on the working face initially increases and then remains stable, but in the range of 2.5 to 3.0 m/s, the changes in the overall dust mass concentration and dust mass concentration of the respiratory zone on the working face are not significant. The dust pollution in the respiratory zone produced by the hydraulic support lowering pillar and moving frame on the working face is quantitatively analysed at different inlet wind velocities of 2.5 to 3.0 m/s to determine the optimum wind velocity for dust suppression on the working face. The optimum wind speed for dust suppression is 2.6 m/s. This study lays a foundation for the ventilation design and dust control in the early stage of a mine and for the establishment of a clean and green production mine.

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