Dust Content and Adhesion Characteristics of Five Corn Samples

2020 ◽  
Vol 63 (2) ◽  
pp. 495-499
Author(s):  
Benjamin M. Plumier ◽  
Yumeng Zhao ◽  
Mark E. Casada ◽  
Ronaldo G. Maghirang ◽  
R. P. Kingsly Ambrose

HighlightsThe corn sample and centrifuge speed interactions were statistically significant predictors of dust generation.Attachment strengths of dust particles were calculated, with forces ranging from less than 4.6 × 10-10 N to 2.1 × 10-8 N.A sequential centrifuge experiment indicated a bimodal distribution of adhesion forces.Abstract. Grain dust explosions are a constant threat to the grain handling industry. Explosions occur when dust accumulates beyond the minimum explosion concentration in a confined area and is exposed to an ignition source. Handling and grain unloading conditions that generate dust, the minimum explosive dust concentration, overpressure from an explosion, and other factors that lead to grain dust explosion are well documented in the literature. The adhesion force that holds grain dust particles to the grain itself is an important factor in better understanding and mitigating dust separation from grain kernels and the resulting dust cloud generation. However, that adhesion force, how it is affected by grain quality, and how it is influenced by particle factors such as size and shape has not been adequately researched. A centrifuge separation technique was used to study the adhesion forces of grain dust. Results showed large variability in dust concentration between the five corn samples tested in this study. The dust particle attachment strength ranged from less than 4.6 × 10-10 N to 2.1 × 10-8 N. Only the sample and centrifuge speed interaction had a statistically significant effect on dust concentrations recovered at a 5% confidence limit. Under repeated centrifugations, the dust removed showed a bimodal distribution of attachment strengths, with three of four samples tested showing a local minimum at 2000 rpm, and the other at 3000 rpm. This study improves the understanding of the fundamental attachment strength behind dust separation from grain kernels. Investigating the size, shape, and surface characteristics of dust particles with varying attachment strengths is important to further understand their adhesion and separation mechanisms. Keywords: Adhesion strength, Dust explosion, Dust mitigation, Grain dust, Grain handling.

Atmosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 489
Author(s):  
Kohei Ono ◽  
Yuki Mizushima ◽  
Masaki Furuya ◽  
Ryota Kunihisa ◽  
Nozomu Tsuchiya ◽  
...  

A new method, namely, force–distance curve mapping, was developed to directly measure the adhesion force of individual aerosol particles by atomic force microscopy. The proposed method collects adhesion force from multiple points on a single particle. It also takes into account the spatial distribution of the adhesion force affected by topography (e.g., the variation in the tip angle relative to the surface, as well as the force imposed upon contact), thereby enabling the direct and quantitative measurement of the adhesion force representing each particle. The topographic effect was first evaluated by measuring Polystyrene latex (PSL) standard particles, and the optimized method was then applied on atmospherically relevant model dust particles (quartz, ATD, and CJ-1) and inorganic particles (ammonium sulfate and artificial sea salt) to inter-compare the adhesion forces among different aerosol types. The method was further applied on the actual ambient aerosol particles collected on the western coast of Japan, when the region was under the influence of Asian dust plume. The ambient particles were classified into sea salt (SS), silicate dust, and Ca-rich dust particles based on individual particle analysis (micro-Raman or Scanning Electron Microscope/Energy Dispersive X-ray Spectroscopy (SEM-EDX)). Comparable adhesion forces were obtained from the model and ambient particles for both SS and silicate dust. Although dust particles tended to show smaller adhesion forces, the adhesion force of Ca-rich dust particles was larger than the majority of silicate dust particles and was comparable with the inorganic salt particles. These results highlight that the original chemical composition, as well as the aging process in the atmosphere, can create significant variation in the adhesion force among individual particles. This study demonstrates that force–distance curve mapping can be used as a new tool to quantitatively characterize the physical properties of aerosol particles on an individual basis.


Author(s):  
E.Y. Chen ◽  
Peter Renner ◽  
K. Lee ◽  
Bing Guo ◽  
Hong Liang

Abstract Solar panel cleaning is important to maintain the efficiency of energy production. In this research, we investigated the effects of relative humidity and condensation on the effectiveness of cleaning. The dust particles are subjected to various forces once they are deposited on the surface of a solar panel. When the dust particles continue to build up, they are also subjected to the adhesion forces from the neighboring dust particles. The adhesion forces from the substrates and the neighboring particles are dependent on the ambient conditions. Fundamentally, the interaction between the adhesion force of particle-particle and particle-substrate under various conditions was discussed in this manuscript.


2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Wen-Zheng Wang ◽  
Yan-Ming Wang ◽  
Guo-Qing Shi

Respirable coal particle generated during underground mining is the main cause for gas-dust explosions and coal workers’ pneumoconiosis (CWP) which needs accurate monitoring especially on its concentration. Focusing on the coal dust pollution in the fully mechanized working face of Huangbaici coalmine, coal particle was sampled for further industrial analysis and FT-IR test to obtain its chemical composition and optical constant. Combined with the simulated spatial distribution of airborne dust, the spectral transmission characteristics of coal dust within wavelengths of 2.5 to 25 μm under different operating conditions were obtained. The simulation results show that the transmittance and aerosol optical depth (AOD) of coal dust are closely linked and obviously influenced by the variation of dust generation source (intensity of dust release, position of coal cutting, and the wetting of the coal seam) and airflow field (wind speed and direction of ventilation). Furthermore, an optical channel of 1260–1280 cm−1(7.937–7.813 μm) which is almost only sensitive to the variation of dust concentration but dull to the diameter change of coal dust was selected to establish the correlation of dust concentration and infrared transmittance. The fitting curve was then applied to retrieve the equivalent dust concentration based on optical information, and the comparison results demonstrate that the estimated pollution level is consistent with field measurement data in engineering practice.


2004 ◽  
Vol 165 (4) ◽  
pp. 529-537 ◽  
Author(s):  
Iwona Bucior ◽  
Simon Scheuring ◽  
Andreas Engel ◽  
Max M. Burger

The adhesion force and specificity in the first experimental evidence for cell–cell recognition in the animal kingdom were assigned to marine sponge cell surface proteoglycans. However, the question whether the specificity resided in a protein or carbohydrate moiety could not yet be resolved. Here, the strength and species specificity of cell–cell recognition could be assigned to a direct carbohydrate–carbohydrate interaction. Atomic force microscopy measurements revealed equally strong adhesion forces between glycan molecules (190–310 piconewtons) as between proteins in antibody–antigen interactions (244 piconewtons). Quantitative measurements of adhesion forces between glycans from identical species versus glycans from different species confirmed the species specificity of the interaction. Glycan-coated beads aggregated according to their species of origin, i.e., the same way as live sponge cells did. Live cells also demonstrated species selective binding to glycans coated on surfaces. These findings confirm for the first time the existence of relatively strong and species-specific recognition between surface glycans, a process that may have significant implications in cellular recognition.


2019 ◽  
Vol 191 ◽  
pp. 413-421 ◽  
Author(s):  
Rima J. Isaifan ◽  
Daniel Johnson ◽  
Luis Ackermann ◽  
Benjamin Figgis ◽  
Mohammed Ayoub

2017 ◽  
Vol 17 (3) ◽  
pp. 2401-2421 ◽  
Author(s):  
Siyu Chen ◽  
Jianping Huang ◽  
Litai Kang ◽  
Hao Wang ◽  
Xiaojun Ma ◽  
...  

Abstract. The Weather Research and Forecasting Model with chemistry (WRF-Chem model) was used to investigate a typical dust storm event that occurred from 18 to 23 March 2010 and swept across almost all of China, Japan, and Korea. The spatial and temporal variations in dust aerosols and the meteorological conditions over East Asia were well reproduced by the WRF-Chem model. The simulation results were used to further investigate the details of processes related to dust emission, long-range transport, and radiative effects of dust aerosols over the Taklimakan Desert (TD) and Gobi Desert (GD). The results indicated that weather conditions, topography, and surface types in dust source regions may influence dust emission, uplift height, and transport at the regional scale. The GD was located in the warm zone in advance of the cold front in this case. Rapidly warming surface temperatures and cold air advection at high levels caused strong instability in the atmosphere, which strengthened the downward momentum transported from the middle and low troposphere and caused strong surface winds. Moreover, the GD is located in a relatively flat, high-altitude region influenced by the confluence of the northern and southern westerly jets. Therefore, the GD dust particles were easily lofted to 4 km and were the primary contributor to the dust concentration over East Asia. In the dust budget analysis, the dust emission flux over the TD was 27.2 ± 4.1 µg m−2 s−1, which was similar to that over the GD (29 ± 3.6 µg m−2 s−1). However, the transport contribution of the TD dust (up to 0.8 ton d−1) to the dust sink was much smaller than that of the GD dust (up to 3.7 ton d−1) because of the complex terrain and the prevailing wind in the TD. Notably, a small amount of the TD dust (PM2.5 dust concentration of approximately 8.7 µg m−3) was lofted to above 5 km and transported over greater distances under the influence of the westerly jets. Moreover, the direct radiative forcing induced by dust was estimated to be −3 and −7 W m−2 at the top of the atmosphere, −8 and −10 W m−2 at the surface, and +5 and +3 W m−2 in the atmosphere over the TD and GD, respectively. This study provides confidence for further understanding the climate effects of the GD dust.


Author(s):  
Svetlana Ratynskaia ◽  
Ladislas Vignitchouk ◽  
Panagiotis Tolias

Abstract The design, licensing and operation of magnetic confinement fusion reactors impose various limitations on the amount of metallic dust particles residing inside the plasma chamber. In this context, predictive studies of dust production and migration constitute one of the main sources of relevant data. These are mainly conducted using dust transport codes, which rely on coupled dust-plasma and dust-wall interaction models, and require external input on the dust and droplet initial conditions. Some particularities of dust modelling in reactor-relevant conditions are analyzed with an emphasis on dust generation mechanisms relevant for disruption scenarios and on dust remobilization mechanisms relevant for ramp-up scenarios. Emerging topics such as dust production by runaway electron impact and pre-plasma remobilization of magnetic dust are also discussed.


10.14311/1759 ◽  
2013 ◽  
Vol 53 (2) ◽  
Author(s):  
Vadym A. Makhlaj ◽  
Igor E. Garkusha ◽  
Nikolay N. Aksenov ◽  
Alexander A. Chuvilo ◽  
Igor S. Landman

Dust generation under powerful plasma stream impacts has been studied in ITER ELM simulation experiments with QSPA Kh-50 plasma accelerator. Repetitive plasma exposures of tungsten have been performed by 0.25 ms plasma pulses and the heat load varied in the range (0.1÷1.1) MJm-2. Main characteristics of dust particles such as a number of ejected particles, their velocity, angular distribution and start time from the surface are investigated. Dust particles have not been observed under heat load below the cracking threshold. Quantity of dust particles rises with increasing heat load. Average velocities of dust particles are found to be strongly dependent on their start time from the surface after beginning of plasma-surface interaction. Maximal velocity achieved a few tens of meters per second.


Author(s):  
Bartosz Pałubicki ◽  
Luďka Hlásková ◽  
Tomasz Rogoziński

Air pollution by wood dust in furniture production sites is an important hygiene issue. The dust is created by all types of wood and wood-based material machining, and its concentration in the working zone surrounding the machining stand depends on the effectiveness of the dust exhaust system. In present research, three setups of the dust extraction system for a conventional table sawing machine are considered while machining particleboards. The results showed a high impact of the exhaust system connection setup on the dust concentration in the air surrounding the sawing machine work stand. The use of both main and auxiliary sawdust extraction connectors together ensured the highest clearness of the air, with only 0.5 mg/m3 of dust concentration. Closing the upper hood leads to a concentration five times higher, while disconnecting it results in a ten times higher dust content. The finest dust particles (<1 µm), however, are the most numerous in the case of closing the hood.


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