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In this work, the performance of residual iron dust (RID) from metallurgic industry was assessed as Fenton catalyst for the treatment of real pulp bleaching wastewater. The focus was on the removal of recalcitrant pollutants AOX (adsorbable organic halides), by a novel, cleaner, and cost-effective circular solution based on a waste-derived catalyst. The behaviour of RID as iron source was firstly assessed by performing leaching tests at different RID:wastewater w/v ratios and contact time. Afterwards, RID-catalysed homogeneous and heterogeneous Fenton processes were conducted to maximise AOX removal from the pulp bleaching wastewater. Reusability of RID was assessed by a simple collect-and-reuse methodology, without any modification. Similar AOX removal under less consumption of chemicals was achieved with the novel heterogeneous Fenton process. Reaction in the bulk solution was the main pathway of AOX removal, given that the low surface area and porosity of the material did not allow for a high contribution of surface reaction to the overall performance. Moreover, AOX removal was similar over two consecutive treatment cycles, with Fenton process being responsible for 56.7–62.1% removal of AOX from the wastewater, and the leaching step adding 11.4–13.2%. At the end of treatment, COD either decreased (1st cycle) or remained unchanged (2nd and 3rd cycle). The operating cost of the optimised heterogeneous Fenton was 3–11% lower than under conventional Fenton process. This work presented a novel, circular solution based on a low-cost waste-derived catalyst, advancing the knowledge needed to foster industrial application of such technologies to increase industrial environmental performance and efficiency. [Display omitted] • Residual iron dust successfully catalysed Fenton process, acting mainly as iron supplier. • Catalyst performance in removing AOX was maintained over consecutive treatment cycles. • The catalyst was successfully reused without any modification or regeneration. • Operating cost of the heterogeneous Fenton was 3–11% lower than conventional Fenton. [ABSTRACT FROM AUTHOR]

• ZIF-67 particles can be evenly distributed and tightly attached to the cellulose paper substrate. • Mild synthesis conditions combined with papermaking processes are suitable for mass production. • The composite filter has a hierarchical porous structure with a large specific surface area. • The optimum sample exhibited removal efficiencies of 98.52% for PM 2.5 and 99.00% for PM 10. • Composite papers possessed excellent mechanical properties and reusability. The combination of functional zeolitic imidazolate frameworks (ZIFs) with suitable substrates is promising for the preparation of advanced filtering materials. In this study, the bleached kraft softwood pulp (NBKP) was composited with ZIF-67 particles via an in situ growth method to fabricate functional paper. Enabled by the traditional papermaking process, ZIF-67 crystals were uniformly and tightly anchored on cellulosic fibers in a facile and economic way. The introduction of ZIF-67 boosted the mechanical performances of the composite paper owing to the presence of electrostatic interactions and hydrogen bonds. Meanwhile, the resultant paper presents hierarchical porous structure with a large specific surface area of 327.07 m2·g−1. The filters with hierarchical pore structure will provide a complex tortuous channel for passing particulates, which can increase the frequency of effective collision between filters and particulates. Air filtering tests demonstrated that the ZIF-67 entrapped paper has superior particle removal efficiency with a low pressure drop and a large dust holding capacity. The optimal ZP-3 sample displayed removal efficiencies of 98.52 % for PM 2.5 and 99.00 % for PM 10. Meanwhile, filtration quality factors were calculated to be 0.15 (PM 2.5) and 0.17 (PM 10), respectively. The filter also has good antibacterial activity. In addition, ZP-x composite paper is easy to regenerate and possesses good reusability. The high-efficient ZP-x filter will have potential applications in fields of air purification. [ABSTRACT FROM AUTHOR]

Due to production technologies such as blasting, transportation, and loading, large quantities of dust are produced in surface mines. This dust not only pollutes the environment but also restricts the development of coal mining enterprises. This work aims to use waste paper as raw material for the efficient extraction of cellulose, in which waste materials can be converted to useable materials. This work can broaden the sources of raw materials and provide new methods for the efficient preparation of dust suppressants. As a matrix, sodium carboxymethyl cellulose is a novel crust-dust suppressant that is synthesized by graft copolymerization with polyvinylalcohol and N-vinylpyrrolidone in this study. The results of experiments revealed the high purity of sodium carboxymethylcellulose prepared in flotation for 20 min, the degree of substitution DS > 0.8, and the viscosity of 2% aqueous solution>300 mPa s, which can satisfy the requirements of the experiments. The microscopic reaction and structure of the product are analyzed by infrared spectrometry, scanning electron microscopy and thermogravimetry, and the microscopic mechanism of a crust-dust suppressant is investigated. The reaction process and structural characteristics of the product were analyzed by infrared spectroscopy and scanning electron microscopy, and the product reaction process and final structure were deduced. Thermogravimetric experiments showed that the product had strong thermal stability and ensured the performance of the product during use. This paper reveals the combination of dust suppressants and coal via molecular dynamics simulation. The product performance experiments show that the product has a high shell strength of 98 HA, satisfactory freeze-thaw resistance and high temperature resistance, permeability higher than 15 mm/min, and dust suppression rate of approximately 88% when the wind speed reaches 15 m*s−1 and it can degrade without pollution. In general, the product can effectively suppress coal dust and other forms of dust. Image 1011236 • A new kind of dust suppressing material with excellent properties was prepared. • Conduct comprehensive tests on the characterization and properties of materials. • Raw materials for preparation are cheap. • Final product can be degraded after being extracted from waste paper. • MS technique was used to analyze the action mechanism of the dust inhibitor. [ABSTRACT FROM AUTHOR]

Developing a flexible nano-composite material which is not only impermeable to low-polar oil, but also has the ability of daytime radiation cooling, remains a huge challenge for both academia and industry. By modifying the fiber network of the dust-free paper using nano-ZnO particles (ZnO-DF), we strategically designed and demonstrated dual capabilities of superhydrophilicity/superoleophobicity and daytime radiant cooling for the flexible cellulose nano-composite simultaneously. A superior surface with superhydrophilic/superoleophobic (oil contact angle up to 159° and water contact angle down to 0°) was attained by regulation of surface energy components and roughness. Furthermore, the materials revealed outstanding corrosion and mechanical damage resistance, 152,788 L m−2 h−1 high permeation flux and >99.2% continuous and efficient oil-water separation performance. In addition, a cooling effect of about 5.6 °C of ZnO-DF paper could be achieved by cooperative function of both radiative cooling and sweat evaporation. It is expected that the ZnO-DF paper is promising for the thermal management of wearable products integrated with passive radiant cooling, phase change cooling (e.g., sweat evaporation) and large-scale industrial oil-water separation. [Display omitted] • A novel and stable flexible cellulose "ZnO-DF paper" nanocomposites were fabricated. • Nanocomposites have multi-functions covering superhydrophilic/superoleophobic and passive radiant cooling. • ◆Cetane-water mixture separation efficiency is up to 99.2%, and the extremely high water permeation flux up to 152,788 L m−2 h−1. • 5.6 °C of moist ZnO-DF paper could be achieved by cooperative function of both radiative cooling and sweat evaporation. [ABSTRACT FROM AUTHOR]

Abstract: Dust accumulation is one of the natural phenomena that adversely affects the performance of solar systems. Since 1942, many efforts have been made to address the severity of deposited particles like dust, water stains, carbon from smoke, pollen in agricultural regions, etc. on the efficiency reduction of solar devices, which results in additional costs either from oversizing the system or from cleaning it. Although various innovative methods have been employed to clean the surface of grimy PVs, a holistic approach needs to show the cleaning mechanism under different climate conditions. This review highlights the findings from several references in three time periods and focusing on their similarities. For scaling up the appropriate mitigation method, four different global zones are explored based on suspended particles in the air. Consequently, the pattern of dust distribution in different parts of the world is assessed and it was found that the Middle East and North Africa have the worst dust accumulation zones in the world. Finally, a set of recommendations and guidelines with regard to the different climatic zones and their characteristics are presented especially for the installers of PV or other solar devices to implement a suitable cleaning system. [Copyright &y& Elsevier]

The grinding process of the angle grinder generates a large amount of dust, which present hazards to the environment and workers' health. In order to capture the grinding dust more efficiently, this paper optimizes the performance of the dust collection hood of the angle grinder by building a grinding experimental platform and using the response surface method (RSM). Using the Box-Behnken design method, the collection quantity M total of all dust particles generated by grinding and the collection quantity M PM10 of PM10 are used as the main performance indicators of the dust collector. Four independent factors such as grinding wheel diameter, suction pipe diameter, mounting angle, and grinding wheel speed of the dust collection hood were optimized to arrive at the best combination of parameters. Through response surface analysis, a quadratic polynomial regression model between each influencing factor and performance indicator is established, and significance test and variance analysis are performed to verify the validity and applicability of the model. Finally, through three-dimensional response surface plots and contour plots, the interactions between each influencing factor are analyzed, and the predicted values of performance indicators under optimal experimental conditions are determined. The experimental results show that the mounting angle has the greatest impact on M total , and the grinding wheel speed has the greatest impact on M PM10. The field engineering application shows that the optimized dust collection hood can effectively prevent dust from escaping. The reduction efficiency of total dust concentration in the grinding place is over 83.6 %, and the reduction efficiency of respirable dust concentration is over 90.0 %. The research results of this paper provide some reference value for the research and application in the field of dust control. [Display omitted] [ABSTRACT FROM AUTHOR]

This paper discusses the newly discovered acoustic waves that arise from the equilibrium between the inertia of dust particles and plasma pressure. The propagation of these waves is demonstrated to be non-linear, with supersonic solitons exhibiting either a positive or negative electrostatic potential, and linear, with normal modes in a dusty plasma. Implementing the unified method and the generalized projective Ricatti equation technique, we generate a variety of optical wave structures for the governing framework. Using 3 D and 2 D dimensional illustrations, the fundamental behavior of the derived solutions is visually analyzed by choosing appropriate values for arbitrary parameters that satisfy the specified constraints. The employed methodologies are acknowledged to be a powerful and effective mechanism for creating solitary wave solutions for non-linear evolution models. [ABSTRACT FROM AUTHOR]

The explosion characteristics of AlH 3 dust clouds with varying micron particle sizes are investigated in this paper. The explosion mechanism of AlH 3 dust clouds is initially explored. The results indicate that the activation energy for hydrogen evolution shows an increasing trend with the AlH 3 particle size, and both of these values are comparable to the 30 kJ/mol desorption energy of hydrogen from large AlH 3 clusters. Due to the rapid dehydrogenation rate and small-size residual aluminum core, fine AlH 3 particles exhibit a continuous gas-phase flame and fast propagation velocity. With increasing particle size, the lower dehydrogenation rate, reduced specific surface area, and higher volume heat capacity contribute to a higher level of incomplete reaction. Consequently, large micro-sized AlH 3 particles display a discrete flame, slower flame velocity, and lower explosion pressure. The flame delamination phenomenon is not observed in our experiments on AlH 3 dust clouds. [Display omitted] • The explosion characteristics of AlH 3 dust with different particle sizes are studied. • The phenomenon of flame delamination is not observed in the AlH 3 dust clouds. • The activation energy for H 2 release increases with particle size, similar to large AlH 3 clusters' desorption energy. • The explosion mechanism of AlH 3 dust with different particle size is revealed. [ABSTRACT FROM AUTHOR]

Magnesium is widely used but often accompanied by frequent magnesium powder explosion accidents. If the variation regularity and mechanism of the minimum explosion concentration (c m) of magnesium powder under the multi-factor coupling effect can be understood, the occurrence of magnesium powder explosion accidents can be fundamentally avoided, and intrinsic safety can be achieved. In this paper, experiments were conducted using a self-made 20 L explosion device to explore the effects of particle size, initial temperature, and equilibrium relative humidity (ERH) coupling on the c m of magnesium powder. The study found that an increase in ERH of moist magnesium powder would lead to easier agglomeration of the dust, making it less prone to activation. Additionally, excessive moisture also absorbed more heat, reducing the ignition sensitivity of the dust cloud and resulting in a continuous increase in c m. However, increasing the initial temperature and decreasing the dust particle size both decreased the c m of moist magnesium powder, weakening the effect of ERH on c m. Furthermore, using the analysis methods of orthogonal experimental range and AHP model, it was determined that the influence weights of the factors coupling effects on the c m of magnesium powder, from highest to lowest weight, were: particle size > ERH > initial temperature. Furthermore, in order to deeper understand the mechanism of the action process that affect the c m of moist magnesium powder, additional experiments were conducted to further confirm that the addition of hydrogen derived from the erosion reaction of moist magnesium powder to the explosion system can reduce the c m of magnesium dust clouds. Moreover, a quantitative mathematical model for predicting the c m of magnesium powder/hydrogen two-phase system was also established. The mechanism of temperature effect on the ignition of moist particles. [Display omitted] • A quantitative mathematical model for predicting MEC of Mg dust/H 2 hybrid is created. • Higher initial temp and lower particle size weaken ERH effect on wet Mg powder MEC. • The higher the ERH, the greater the effect of initial temp on the MEC of Mg powder. • Use orthogonal test range and AHP model to assess factors' impact weight on dust MEC. • Impact weights of factors coupling on dust MEC: Particle size > ERH > Initial temp. [ABSTRACT FROM AUTHOR]

The Shuiyindong gold mine in Guizhou is used as a case study in this paper to study patterns of dust pollution occurring with traditional electric-rake operation. In particular, the study uses the northern quarry of the twenty-third line in the first middle section of the second mining area and establishes a three-dimensional simulation model of equal size. It uses Computational Fluid Dynamics (CFD) to simulate and analyse the airflow traces and distribution of dust concentration in the relevant roadway during each stage of the electric-rake operation. The simulation results show that the airflow in the working roadway has a spiral movement and produces reverse dirty-wind circulation towards the end. Dust flows out of the working roadway from the 8th second of operation, and dust concentration reaches a peak in the working roadway at the 12th second of operation at an average dust concentration of 37.5 mg/m³. The dust concentration drops rapidly from the 120th second and reaches the maximum dust concentration permitted for operation at the 180th second of operation. The validity of the simulation is tested by comparing the actual measured data at the site with the simulation results. Finally, the simulation results are analysed using violent Python, and the solution is used to divide the roadway into areas according to the human breathing range. The paper analyses the distribution of dust concentration at an average human breathing height, providing an established theoretical basis for dust-control work in mines. [Display omitted] [ABSTRACT FROM AUTHOR]

Pleated cartridge with triangular structure is prone to clogging when filtering sticky dust, leading to a significant reduction in filtration capacity. In this paper, a method of pre-cladding low-viscosity dust was introduced to promote the filtration and cleaning performance on sticky dust. The adhesion of six types of dusts was tested by both reverse blowing and pulse-jet cleaning. The effect of dust feeding rate, filtration velocity and pre-cladding pressure drop on the dust layers was investigated. Through comparative tests, the cleaning cycles reduce rates of two loading methods were 45.99% and 15.89%, while dust emission concentrations were 1.83 and 2.03 mg/m3, which reveals that the pre-cladding method can increase the filtration efficiency in the early stage and improve the cleaning performance. The increased pressure drop with hybrid and pre-cladding methods under two times cleaning process were 8.8, 15.8, 8.4 and 14.8 Pa, which demonstrated that hybrid method is applicable in industrial application. This study is aiming to provide an efficient filtration and cleaning method to avoid clogging during filtering sticky dust. [Display omitted] [ABSTRACT FROM AUTHOR]

Aluminum hydride (AlH 3) dust is a high-capacity hydrogen storage material but is prone to explosion. In this paper, explosion characteristics and flame propagation behavior of AlH 3 dust are investigated. The results indicate that the exposure of bare aluminum and the increase of specific surface area lead to the maximum explosion pressure of AlH 3 dust being 4 times higher than that of Al dust. The enhancement of heat transfer by hydrogen combustion causes a higher combustion rate, leading to a higher maximum explosion pressure rise rate and flame propagation velocity of AlH 3 dust. The thermo-diffusive instabilities and the evolution of hydrogen result in a pulsation flame propagation velocity of AlH 3 dust. Combining the explosion temperature calculated by NASA CEA with the explosion residues analysis, the explosion mechanism of AlH 3 dust is further revealed. The break of the oxide film and the combustion of hydrogen result in a different explosion mechanism. • The explosion characteristics and flame propagation behavior of AlH 3 dust are investigated. • The hydrogen evolution characteristic is studied by the comparison of Al dust. • The explosion mechanism of AlH 3 dust is revealed. [ABSTRACT FROM AUTHOR]

The Visual Monitoring Camera (VMC) is a small imaging instrument onboard Mars Express with a field of view of ∼40°x30°. The camera was initially intended to provide visual confirmation of the separation of the Beagle 2 lander and has similar technical specifications to a typical webcam of the 2000s. In 2007, a few years after the end of its original mission, VMC was turned on again to obtain full-disk images of Mars to be used for outreach purposes. As VMC obtained more images, the scientific potential of the camera became evident, and in 2018 the camera was given an upgraded status of a new scientific instrument, with science goals in the field of Martian atmosphere meteorology. The wide Field of View of the camera combined with the orbit of Mars Express enable the acquisition of full-disk images of the planet showing different local times, which for a long time has been rare among orbital missions around Mars. The small data volume of images also allows videos that show the atmospheric dynamics of dust and cloud systems to be obtained. This paper is intended to be the new reference paper for VMC as a scientific instrument, and thus provides an overview of the updated procedures to plan, command and execute science observations of the Martian atmosphere. These observations produce valuable science data that is calibrated and distributed to the community for scientific use. • The preparation of an engineering camera to be used as a science instrument is described. • Developed procedures enabled this new fully operational science instrument. • Low-cost cameras can expand the science return of current and future space missions. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) panels' photoelectric conversion efficiency will decrease as dust deposition on their surface. An approach to dust removal on the PV panel's surface by longitudinal high-speed airflow was investigated to increase the output power. In this paper, commercial CFD software was used to numerically simulate the characteristics of dust removal by longitudinal high-speed airflow. The PV panels' output characteristic model under the action of dust removal by high-speed airflow is established by Simulink software, and the influence of high-speed airflow on the output characteristic is studied. Firstly, the dust removal mechanism of the PV panel under high-speed airflow is studied. Secondly, the impact of different tilt angles of the PV panel, dust particle size, airflow velocity, and blowing time on the dust removal effect of the PV panel surface were studied. The optimal airflow velocity and blowing time were obtained according to the airflow velocity and blowing time and their influence on the dust removal rate. Finally, the effect of high-speed airflow dust removal on PV power generation's efficiency and output characteristics is studied. The findings demonstrate that as the tilt angle increases, so does the dust removal rate increases continuously. In addition, the rate at which dust is removed increases with airflow velocity and blowing time. When the tilt angle is 30°, the best airflow velocity of dust removal is 5 m/s, and the best blowing time is 8 s. When the tilt angle is 45°, the best airflow velocity of dust removal is 10 m/s, and the best blowing time is 5 s. With the increase in airflow velocity and blowing time, the output power of PV panels continues to increase. When the airflow velocity is 10 m/s, and the blowing time is 5 s, 7.5 s, 12.5 s, and 15 s, the maximum output power after dust removal is increased by 15.44 %, 23.05 %, 23.38 %, and 23.39 %. This paper's research results can guide the design of the practical engineering application of longitudinal blowing high-speed airflow in the dust removal of PV panels. • A dust removal method based on longitudinal high-speed airflow on the surface of PV panels. • Dust removal under the action of longitudinal high-speed airflow is simulated by CFD. • The effect of high-speed airflow dust removal on the output power is studied. [ABSTRACT FROM AUTHOR]

[Display omitted] • Inorganic dusts had higher adsorption efficiencies of explosives than organic dusts due to their higher polar characteristic. • The collection rates of dust were 5 – 15%, and clay and cotton fabric had hig her collection rates. • The most intensive detection times of RDX were later than those of TNT and PETN. • The detection limits for lensing cleansing paper were better than for poly(tetrafluoroethylene). • The detection limits of explosives adsorbed in dust were much higher than those of pure explosives. Vapor and particulate matter from explosives can be adsorbed onto dust, enabling their detection in security and military applications. In this study, model explosive-adsorbed dust specimens were prepared using four types of dust from two inorganic substances [silica (SL) and clay (CL)] and two organic materials [sawdust (SD) and cotton fabric (CF)]. Three explosives, namely 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and pentaerythritol tetranitrate (PETN), were investigated, along with two different collection filters of poly(tetrafluoroethylene) (PTFE) and lens cleansing paper (LCP). The dust was sprayed in a hood and collected using a cyclone collector. The explosive components present in the dust were rapidly detected using ion mobility spectrometry (IMS). The adsorption efficiencies of TNT, RDX, and PETN onto dust were 36 – 97, 45 – 76, and 37 – 90 %, respectively, and the values of the inorganic dusts were higher than those of the organic dusts. The dust collection rate ranged from 5 to 15 %, and decreased in the order of CL > CF > SL = SD. The factors influencing rapid explosive detection were the intrinsic vapor pressure of the explosive, interactions between the dust and the explosive, thermal conductivities of the dusts and collection filters, and structure of the collection filter. Due to the low vapor pressure of RDX, this explosive was detected later than TNT and PETN. In most cases, detection was more rapid when using the LCP than when using the PTFE because of the thicker and woven structure of the PTFE filter. The detection limits achieved using the LCP (0.049 – 1.17 μg) were lower than those of the PTFE (0.67 – 10.05 μg). When the PTFE was used, the detection limits for the organic dusts were lower than those for the inorganic dusts. Notably, the detection limits of the explosives adsorbed onto dust were significantly higher than those of the pure explosives. [ABSTRACT FROM AUTHOR]

Dust control is of great significance to industrial process safety and environmental protection. Wet dust reduction is the most commonly used dust control technology, and the physical and chemical properties of water are closely related to its dust reduction ability. In order to improve dust reduction efficiency, scholars have done much fruitful work in the physical and chemical modification of water. It is essential to summarize the progress of this research direction and shows what is lacking at present in recent years. This paper reviews the research progress on improving the performance of water for dust reduction by physical and chemical methods in the past ten years. The physical methods are mainly adopted to improve dust reduction performance in spray technologies, which include air atomization, ultrasonic atomization, magnetized water and water mist charging. And the chemical methods are mainly used to prepare dust suppression materials, which can be distinguished by single-phase dust suppressants and gas-liquid two-phase dust suppression foam. In this paper, we analyze the advantages as well as disadvantages of various methods and point out the unresolved issues. Furthermore, the development directions are proposed to provide meaningful guidance for wet dust reduction technologies. [Display omitted] [ABSTRACT FROM AUTHOR]

The objective of this work was to prepare low cost CaCO 3 nanofillers for wet end papermaking application. CaCO 3 nanofillers were successfully prepared from commercial limestone and white waste marble dust using wet carbonation technique. Anionic (sodium oleate) and cationic surfactants (CTAB) were used to modify the size, morphology and surface property of CaCO 3 . The prepared CaCO 3 fillers were applied in paper handsheets and their effect on paper quality was systematically investigated. The results obtained from XRD and FTIR revealed that the prepared CaCO 3 particles were typically calcite. The presence of surfactant during the preparation significantly reduced the particle size and changed the morphology from scalenohedral to rhombohedral as illustrated from TEM results. The surfactant modification of filler improved the retention and consequently all the paper optical properties significantly increased. However, the strength properties were practically unchanged despite the high retention values obtained compared with GCC, indicating improved affinity of the filler particles to the fibres. Oleate modified CaCO 3 showed higher effect on retention, apparent density, opacity, and mechanical properties than the CTAB modified CaCO 3 . The SEM images of paper handsheets confirmed the results and indicated that the modified nano CaCO 3 are highly retained and more effectively adhered and bonded to pulp fibre, in addition to their uniform distribution on paper surface. [ABSTRACT FROM AUTHOR]

• RACs in dust impressions were similar size/larger than their test impression mates. • RACs with positional and geometric similarity occurred between unrelated outsoles. • A minimum of 3.1% of shoes had a non-zero RAC-RMF based on features = 2.8 mm. • A maximum of 32% of shoes had a non-zero RAC-RMF based on features of any size. This study serves as Part II of an investigation into the random match frequency of randomly acquired characteristics (RAC-RMF) in footwear evidence. In Part I, RAC-RMF was estimated in a dataset of laboratory-simulated crime scene impressions deposited in blood. For Part II, a second dataset was created composed of impressions deposited in dust on paper or tile, with the latter lifted using gelatin or Mylar film. A total of 1,513 RACs were identified from more than 160 dust impressions and compared to RACs with positional similarity in test impressions from 1,299 non-mated outsoles. RACs of any size deposited in dust exhibited a 31% decrease in shoes with non-zero RAC-RMFs as compared to their mated test impressions, while those deposited in blood exhibited a 45% increase. When only considering shoes with at least one RAC deemed forensically-reliable (length ⩾ 2.8 mm), 3.1% of shoes contributing dust impressions and 3.4% of shoes contributing blood impressions exhibited relative RAC-RMFs at a value ⩾ 0.0008. Although each dataset resulted in a comparable rate for encountering non-zero RAC-RMFs, the estimate for dust was based on twice the number of RAC comparisons (154,477) than those performed when assessing blood (77,566). While these results are considered specific to the non-mated impressions and methods of analysis described herein, and continued work is required before rates can be fully understood and reported in forensic casework, this study encountered non-zero RAC-RMFs for shoes exhibiting at least one forensically-reliable RAC at a more frequent rate than any estimates previously reported. [ABSTRACT FROM AUTHOR]

Interstellar dust (ISD) particles penetrate the solar system due to the relative motion of the Sun and the local interstellar cloud. Before entering the heliosphere, they pass through the heliospheric interface – the region of the solar wind interaction with the interstellar plasma. The size distribution and number density of dust grains are modified in the interface essentially. The modification depends on the charging of the dust particles along their trajectories. In this paper, we present modeling results of the charging of ISD particles passing through the heliospheric interface. The main physical processes responsible for the charging within the heliospheric conditions are the sticking of primary plasma particles, secondary electron emission, photoemission, and the effects of cosmic ray electrons. We consider two methods to calculate the electric charge of ISD particles based on (1) the classic steady-state assumption that the charge depends only on local plasma and radiation conditions and (2) the dynamical computation of charge along the particle trajectory. We demonstrate that the steady-state assumption is quite justified to model trajectories and number density distributions of relatively big ISD grains (radius of 100 nm and larger) penetrating the heliosphere. The estimates show that ISD grains of these sizes require less than 0.25 years (distance of ≈ 1 au) after transition from the LISM into the heliosphere to reach an equilibrium. For small particles (radius of 10 nm), the dynamical computation of charge influences the trajectories and modifies the number density substantially. The dust density accumulations are distributed within a more elongated region along the heliopause in case of dynamically changed charge as compared with the use of a steady-state charge approximation. As a result, the magnitudes of number density at the points of density features differ several times between the results obtained by the two considered approaches. [ABSTRACT FROM AUTHOR]

Due to the limitations of the existing atmospheric surface layer (ASL) turbulence prediction models during dust storms, therefore, this paper uses multi-scale signal reconstruction and HSM as the basic framework to propose a prediction model of streamwise and vertical wind speed fluctuation during dust storms in near-neutral ASL. The input of this model is only friction wind speed. In the reconstruction of large-scale signals, the random phase control and the introduction of structural inclination angle reflect the coherence of large-scale turbulent structures. Through the modification of the HSM method, turbulence events in different quadrants are introduced into the prediction model. The introduction of the influence of dust particles on turbulent fluctuation is achieved by modifying the characterization parameters of the Kaimal spectrum. The model proposed in this paper can not only reflect the coherence and inclination of large-scale turbulent structures, but also reflect the contribution of different turbulent events. In addition, the power spectrum predicted by the model, the event contribution ratio of different quadrants, and the turbulence intensity are in good agreement with the field observation results both qualitatively and quantitatively. These results show that the model can be used to predict the streamwise and vertical wind speed fluctuation. • Turbulence events in different quadrants are introduced into the prediction model. • The model can reflect the coherence and inclination of large-scale turbulent structures. • Predicted results are in good agreement with the field observation. [ABSTRACT FROM AUTHOR]

In the current paper, we have studied the impact of microwave (2.45 GHz) plasma treatment of submicronic (250–600 nm) tungsten dust, upon tritium gas retention. Herein, the conducted experiments have emphasized the role of dust treatments in pure hydrogen gas versus hydrogen plasma, before the tritiation process at different pressures. The obtained tritiated dust was analyzed via room temperature desorption and dissolutions. Additionally, Scanning Electron Microscopy and X-ray Photoelectron Spectroscopy analyses were performed to observe the changes induced by the plasma discharge. The results have shown that the Specific Surface Area of dust is enhanced by using microwave hydrogen plasma treatments, resulting in a high tritium gas retention inside the submicronic tungsten dust. [Display omitted] • We studied the 3H retention in W submicronic dust. • One compared 3H retention in untreated/plasma-treated dust. • Microwave plasma dust treatment enhanced 3H retention. [ABSTRACT FROM AUTHOR]

In this paper, a multi-physics field coupled model of electric, flow and particle fields was constructed by COMSOL to compare the effects of three different corrugated dust collector plates on electric field distribution, airflow field, particle trajectories and dust removal efficiency in an electrostatic precipitator, and to compare them with a conventional electrostatic precipitator with a parallel plate structure. The results indicated that the corrugated dust collection plate influenced the electric field within the ESP channel, while the wire plate spacing directly affected the size and distribution of space charge density. Furthermore, the corrugated dust collection plate also affected the EHD flow within the channel, with the D2-ESP and D3-ESP being the most strongly influenced by the ionic wind. By comparing the dust removal efficiency of the four ESPs, we found that D2-ESP has the highest dust removal efficiency, followed by D3-ESP, then Flat-ESP, and finally D1-ESP. The ranking order of the four ESPs' dust removal efficiency is consistent with the ranking order of the space charge density within the four ESP channels, which shows that the size of the space charge density directly affects the dust removal efficiency of ESPs. Numerical simulation results show that the change of wire plate spacing is the main reason why corrugated ESP affects the dust removal efficiency of electrostatic precipitators. [Display omitted] [ABSTRACT FROM AUTHOR]

The wet filter dust collector (WFDC) is widely used in dust control in various industries, but its dust collection mechanism is unclear, and the influence of the metal-based filter screen (MBFS) inclination angle on the dust removal performance is still uncertain. In this paper, the liquid film crushing and collecting dust mechanism of MBFS and the influence of its inclination angle on the dust removal performance of WFDC are studied. The results show that with the increase of inclination angle (30° to 150°), the average pressure drop of WFDC first decreases and then increases, the average dust concentration first increases and then decreases, and the MBFS dust removal performance is optimal at 90°. The optimized WFDC was applied on-site in a coal preparation plant, which exceeded the dust suppression efficiencies of 91 % and 88 % for total dust and respirable dust, respectively. The research results are expected to provide theoretical guidance for WFDC design and improvement. [Display omitted] [ABSTRACT FROM AUTHOR]

A scientific method for evaluating the dust generation capacities of coal samples with varying properties and moisture contents is of great significance for the study on dust generation and prevention in coal mines. The impact crushing dust generation method, which attributes coal dust generation to a single variable, i.e. energy, avoids the interference terms such as the conical pick angle, depth and rotating dust in the cutting process and can well reflect the dust generation law of coals with different hardness. However, the selection of sample size, sample pretreatment method, impact crushing energy, dust screening method and time, impact crushing and dust screening program setting, etc. is controversial or inconclusive in current coal impact crushing dust generation method, leading to errors that affect the test results to varying extents. Consequently, the research results can hardly be universally recognized. In this paper, a large number of comparative tests were performed in the impact energy range of 20–200 J and the moisture content of 0–5.5%. The following conclusions were obtained: The particle size of the sample is determined to be 12–15 mm. It is the most reasonable to conduct dust screening on a vibrating screening machine for 5 min. The numbers of impacts and screenings should be minimized on the premise of ensuring sufficient crushing of the sample, and the program of 5 impacts plus 1 screening can excellently reflect the effect of moisture increment on dust generation capacity reduction. Furthermore, the reliability of the above conclusions and the adaptability of the test method proposed in this paper were verified by coal samples from another two mining areas. The verification results confirm the above conclusions and further prove the remarkable repeatability and reliability of the proposed test procedure. [Display omitted] • A complete dust generation test process was established. • Several key influencing factors were analyzed and discussed. • The optimum test parameters were determined. • The relationship between moisture and coal dust production by crushing was obtained. • The reliability and applicable of test method has been verified. [ABSTRACT FROM AUTHOR]

This paper argues that uncertainty can be mobilized as a geographic discourse to influence how the state negotiates competing responsibilities for health. Uncertainty shapes the struggles that define what constitutes a human health risk and how it is governed. This politics often manifests through contested scientific knowledge claims. When the state regulates occupational health risk, it does so within a legal framework that defines the state's responsibilities to different populations. In the US, these responsibilities are to protect working people and the industries they work for; responsibilities that are negotiated during processes to develop new regulations. This paper examines arguments made during public hearings in 2014 on proposals to lower the exposure limit to respirable crystalline silica. Respirable crystalline silica is a carcinogenic dust used during hydraulic fracturing and other industries. The paper uses the example of the hydraulic fracturing industry to show how industry rebrands its flexible geographies - its variable spatial and temporal configuration of work, equipment, and bodies - as uncertain such that the industry, and its occupational exposures, are ungovernable. The evidentiary process of rulemaking has the effect of imbuing industry with 'health' such that human health risks are considered alongside industry's capacities. Thus, the hearings provide a venue for industry to contest new regulations using discourses of uncertainty, not just regarding the science that justifies lower limits, but also the geographies on which the industry relies. [ABSTRACT FROM AUTHOR]

Dust detection using remotely sensed measurements has been one of the challenging problems encountered by atmospheric scientists. MODerate Resolution Imaging Spectroradiometer (MODIS) on the Terra (T) and Aqua (A) platforms have been a versatile sensor for well over 21 and 18 years respectively, and have been extremely useful in the retrieval of aerosol information over the entire globe. The MODIS radiances from the Level 1B in general are expected to be within 5% accuracy in the reflective wavelengths and within 1% in the thermal emissive wavelengths. In this paper, we evaluate the sensitivity of previously developed dust detection technique based on thermal emissive wavelengths, which correspond to MODIS bands 20, 29, 31, and 32 respectively. The Thermal Emissive Dust Index (TEDI) performed very comparably to the traditional Aerosol Optical Thickness (AOT) retrievals by MODIS reflective channels. Since the MODIS Thermal Emissive Bands (TEB) are well calibrated on-orbit using a BlackBody (BB) source, the calibration of these long wave infrared bands is quite robust. As A-MODIS continues to perform well beyond its designed lifetime of 6 years, the instrument has undergone various levels of degradation during its mission time. As a consequence, it is imperative to check the impacts of calibration on the higher-level retrievals. In this paper, we rigorously analyze the sensitivity of TEDI due to the impact of calibration by the afore-mentioned TEB. The perturbation of the dominant (linear) calibration term demonstrated the following: first, there was a correlation in the sensitivity of the TEDI due to the uncertainty in the linear calibration term. Based on a perturbation in the linear calibration term for all aforementioned bands over a range of ±5% yielded the TEDI sensitivity to vary from approximately −3.2% to about −3.6%. When considering the uncertainty in each individual band significant changes were observed. The least change was observed for the perturbation in the calibration of band 20 with the TEDI sensitivity and the largest sensitivity in TEDI was observed in the perturbation of band 31 calibration. Thus, in the case of TEDI, noticeable sensitivity due to calibration uncertainty was observed in bands 29, 31, and 32, reiterating the importance of the TEB calibration in these bands. Also, the dust detection scheme based on A-MODIS was successfully transferred to the follow-on sensors such as Suomi (SNPP) and NOAA 20 (N20) VIIRS. The results presented in this paper would be extremely helpful in understanding impacts of calibration on the higher-level products for both current and future missions based on the MODIS heritage. Finally, the work also identifies the importance of radiometric fidelity in maintaining the accuracy of the dust detection. Results presented will show drastic improvement of the Saharan dust detection after the reduction of the electronic crosstalk in the 8.5 µm channel of T-MODIS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Black liquor can be acidified with spent sulfuric acid to precipitate lignin. • Lignin can be used as a reducing agent in reutilization of steel waste. • Red dust, BOF scrap fines, IOF, mill scale can be used in geopolymeric material. • Replacing 30% of fly ash w/ mill scale in geopolymers increased compressive strength. Recycling wastes back into a manufacturing process, or into a separate product, is an important challenge. The primary aim of this work was to combine wastes from the steel industry, the galvanizing industry and the pulp and paper industry to form two new useful products. The steel industry generates the wastes red dust, mill scale, blast oxygen furnace slag and iron ore fines. Galvanizing industrial facilities dispose of sulfuric acid contaminated with iron. The pulp and paper industry produces the byproduct black liquor, which is high in lignin. Inserting these wastes as resources into the steel industry, or as stand-alone products, could reduce the need for virgin materials. The main methodology of the work was three-fold. First, spent sulfuric acid was used to precipitate the lignin from black liquor. Second, this lignin was combined with steel industry wastes and geopolymeric materials to make briquettes, a sustainable reducing material for steelmaking furnaces. Briquettes contained red dust, mill scale, blast oxygen furnace slag, iron ore fines and lignin precipitated from black liquor with spent sulfuric acid. Key research findings of compressive strength and weight loss testing showed the briquettes to be feasible for steel-making furnace use. Third, these steel industry wastes were investigated as a partial fly ash replacement in geopolymers. Main research findings were that compared to the control geopolymer, these geopolymer samples improved compressive strength and gave similar workability. Thus, the investigated wastes have the potential to both increase recycling in the steel industry and to improve geopolymeric products. [ABSTRACT FROM AUTHOR]

Dust plays a key role in many Earth system processes and is ubiquitous in the Martian atmosphere. Various intensive field campaigns, laboratory analyses, space-based remote sensing missions, and global modeling efforts aim to characterize dust optical properties. This is a bountiful time for dust scientists, and yet the interpretation of retrievals and comparison to models remains complicated by various conflicting assumptions that are part of each algorithm. For example, the conversion of satellite radiance measurements into products like aerosol optical depth for model evaluation depends upon aerosol properties like particle size and shape that are often prescribed and not part of the retrieval. Conversely, the model calculation of aerosol optical depth often uses different assumptions. The goal of this review is to first document algorithmic assumptions by various satellite retrieval products and models, and identify where there is consistency and where there are differences. In general, the differences documented in this paper reflect uncertainties resulting from incomplete observational characterization of dust aerosols and limitations in our understanding. Second, we note what observations might reduce uncertainties in our knowledge and bring greater consistency to retrievals and models, allowing for a more rigorous and harmonious comparison. The lack of comprehensive and realistic shape models for dust is an outstanding issue, such that closure between forward modeling from particle refractive index, shape, and size and observed optical properties cannot be achieved. Limitations in the computational methods that must be applied to model scattering from complex shapes also makes accurate optical modeling for dust challenging. Field observations indicate the persistence of coarse and giant dust particles at higher altitudes and farther downwind from their source than previously expected. Remote sensing retrieval algorithms based on observations at visible wavelengths have limited sensitivity to these particles and generally do not consider them, although a recent product based on longwave radiances is encouraging. Current measurements of the refractive index of bulk dust and fundamental dust minerology components such as hematite vary widely, inhibiting attempts to represent the variability in dust optical properties and forcing, as expected from different major dust source regions on Earth that have varying mineralogical composition. Some remote sensing retrieval algorithms allow for limited refractive index variability in their inversion solutions through mixing with other fine mode aerosol models, or optimizing the single scattering albedo, but Earth system models surveyed for this paper assume a globally uniform, size-invariant refractive index. Although no Martian dust samples have yet been returned to Earth, remote sensing observations indicate that Martian dust is globally homogenous in composition, and a single spectral refractive index assumption has been widely adopted to represent Martian dust. The lack of comprehensive, statistically representative measurements of dust particle microphysical properties (size distribution, morphology, complex index of refraction spectra, internal structure heterogeneity), and the resulting optical properties, limits our ability to verify the fidelity of these assumptions. A chain of measurements is needed, ranging from characterizing individual dust mineralogy components (e.g., pure hematite and goethite) to in situ sampling of complex atmospheric aerosol mixtures. Such results could be applied to both remote sensing retrievals that characterize the optical properties of the total aerosol burden in the atmosphere from total radiance measurements, and to global models that represent the total aerosol burden in the atmosphere by building it up from the balance of individual aerosol sources and sinks. • Algorithmic assumptions by various satellite retrieval products and models • No closure between forward modeled and observed dust optical properties. • Retrieval algorithms using visible channels have low sensitivity to large particles. • Field observations indicate the persistence of coarse and giant dust particles. • Retrieval algorithms and global models make different refractive index assumptions. [ABSTRACT FROM AUTHOR]

Pleated cartridge dust collectors are widely used in various industrial production environments, in its use, pulse-jet cleaning is a crucial step. Despite the importance of pulse-jet cleaning, there was a widespread problem of uneven cleaning in the upper part of the filter cartridge. In this paper, a built-in open-hole dust cleaner (BODC) was developed to improve the pulse-jet cleaning performance, ameliorate the problem of uneven cleaning and prolong the filter cartridge's service life. The filtration and pulse-jet cleaning test system was established to verify the effect of BODC. Based on the comprehensive comparison and analysis of pulse-jet pressure at the four types of measuring points, the best BODC in this experiment is 6 mm 4 holes with composite pressure of 1.52 MPa. The best BODC and ordinary nozzle were compared with respect to pressure drop. The results showed that the change rule of pressure drop of BODC is similar to that of the ordinary nozzle. The average filtration cycle of BODC and ordinary nozzle was 1300 s and 928 s, respectively. The dust emission concentration of the dust collectors of both cleaning methods during filtration was 1.354 mg/m3 and 1.412 mg/m3, respectively. A significant improvement in cleaning uniformity has been demonstrated when the BODC is used. Ultimately, the best BODC in this experiment was applied on site at the excavation face of Donghuantuo Coal Mine, which resulted in an average dust removal efficiency of 95.2% for total dust and 93.2% for respirable dust, with no residual dust left in the upper part of the filter cartridge after cleaning. [Display omitted] [ABSTRACT FROM AUTHOR]

The Comet Interceptor space mission, selected by ESA in June 2019 as the first F-Class mission, will study a dynamically new comet or an interstellar object by a unique multi-point 'snapshot' measurement. The mission design will allow to complement previous single spacecraft's fly-by cometary observations. The Dust Impact Sensor and Counter (DISC), devoted to the dust coma characterization, is part of the payload selected for Comet Interceptor. It will be mounted on-board two of the three spacecraft, as part of the Dust-Fields-Plasma (DFP) suite, dedicated to understand further: 1) dust in the coma; 2) magnetic field; 3) plasma and energetic neutral atoms. DISC architecture originates from the Impact Sensor subsystems, part of the Grain Impact Analyzer and Dust Accumulator (GIADA) that successfully flew on-board the ESA/Rosetta spacecraft. DISC main scientific objectives are: 1) to define the dust mass distribution for particles in the mass range 10−15 − 10−8 kg ejected from the cometary nucleus; 2) to count dust particles with mass > 10−15 kg; 3) to constrain dust particle density/structure. In this paper, we describe DISC design, aims, methods, feasibility and performances evaluations, carried out by real and simulated dust impacts and by retrieving the number of particles, and their corresponding momentum, using the Comet Interceptor's Engineering Dust Coma Model. [ABSTRACT FROM AUTHOR]

The finest fraction of the lunar regolith, namely the lunar dust, poses a challenge for hardware design and lunar operations. The Apollo missions experienced equipment malfunctions and failures due to dust interactions with hardware. In this work we focus on the problems related to the clogging of rigid body mechanisms. We explain the causes of the problem and propose a solution consisting of replacing traditional mechanisms with compliant mechanisms. There are multiple methods for synthesizing compliant mechanisms, but two approaches are most commonly used: analytical design and topology optimization. In this paper using a compliant gripper as an example, the suitability of these methods to design compliant mechanisms used in extra-vehicular activities is investigated. In doing so, the feasibility of using complaint mechanisms in the lunar equipment as part of dust mitigation strategies for surface projects is also demonstrated. • Lunar dust poses a challenge for surface hardware. • Compliant mechanisms are dust resilient — implicit dust mitigation technology. • Compliant mechanisms can replace existing mechanisms like Apollo geological tools. [ABSTRACT FROM AUTHOR]

• A new model of dust impact on grid-connected PV was proposed. • The dust characterization and effects in Sohar, Oman was investigated. • Experimental validation of the proposed model with the techno-economical evaluation presented. A grid-connected photovoltaic system was tested and investigated for the entire year under desertic weather exhibited. The system contains 1.4 kW PV and 1.7 kW inverter —the data was measured every second and used to model and evaluate the system performance. However, dust is one of the essential parameters that affect grid-connected photovoltaic performance, yield, and profitability. In this paper, a proposed model has been takes into consideration the dust impact on grid-connected photovoltaic performance in a novel way. The outcomes demonstrate that the proposed model precisely anticipated the system performance and validated through experimental results. However, it is found that the photovoltaic, inverter, and performance efficiencies are 10.80%, 94.00%, and 73.00%, respectively. Besides, the average yield factor is 141.39 kWh/kWp, and capacity factor is 19.64%. It concluded that the system productivity in Oman is within the prospected rate. The information in this paper is valuable for investors, researchers, and engineers interested in grid-connected photovoltaic and dust impact in Oman and neighboring countries. [ABSTRACT FROM AUTHOR]

Due to the tiny size of dust particles and the low atmospheric pressure, the Martian aeolian activity between Martian dust particles and Martian airflow should be considered as a rarefied two-phase flow. In this paper, a simulation approach for the rarefied characteristic of Martian dust storm has been studied based on discrete element method (DEM). First, the simulation approach based on the DSMC method was studied, and a series of DSMC simulation of Martian rarefied airflow were carried out in dsmcFoam. Second, the DEM simulation approach was used for the simulation of Martian rarefied airflow, and the simulation accuracy was proved by comparing with the DSMC simulation results. Finally, a series of simulation of Martian aeolian activity have been carried out in the DEM simulation software EDEM. This paper provides a new approach for the investigation on the two-phase flow of Martian aeolian activities. Unlabelled Image • The rarefied characteristic of Martian aeolian activities was analyzed. • A new simulation approach for Martian rarefied airflow was proposed. • DEM simulation results were compared with DSMC simulation results. • hSimulations based on DEM were performed for Martian aeolian activities. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) power generation has become one of the key technologies to reach energy-saving and carbon reduction targets. However, dust accumulation will significantly affect the electrical, optical, and thermal performance of PV panels and cause some energy loss. For this reason, appropriate cleaning measures are needed to restore their performance and power output. Many researchers have reviewed the effects of dust on the performance of PV panels and cleaning methods, but their coverage is narrow and lacks more in-depth summarization, comparison, and critique of key quantitative results. Using the Web of Science database as the main search source, this paper provides a comprehensive overview of research results on the mechanisms and influencing factors of dust deposition on photovoltaic panels, photovoltaic performance loss and prediction models, cleaning methods, and dirt monitoring systems. The results found that the module power output degradation due to dust deposition is more serious in different regions, ranging from 7% to 98.13%. The automatic cleaning robot, as an emerging intelligent technology, has a better cleaning effect and can increase PV efficiency by up to 49.53%. This paper also proposes a comprehensive strategy for dust prevention on PV panels that integrates "real-time monitoring of dust accumulation - model prediction of losses - and optimization of cleaning solutions", emphasises the development of new intelligent cleaning methods represented by robots and drone cleaning, and suggests promoting the application of AI in the monitoring and cleaning of PV modules to accelerate the process of achieving carbon neutrality. [ABSTRACT FROM AUTHOR]

Periodic cleaning of photovoltaic (PV) panels, such as every three months, is a common industry practice. However, this fixed period may not be optimal for maximizing the profit of a PV power generation system, due to numerous time-variant influencing factors, such as weather, temperature, etc. To increase the overall profit of a solar farm, it is highly desirable to have a flexible cleaning schedule that considers time-variant influencing factors. For this requirement, a rolling-horizon cleaning recommendation system is presented in this paper. Within this cleaning recommendation system, a prediction model and profit model are proposed. The prediction model, called the ensemble long-term and nonlinear autoregressive, can provide a time-variant future horizon by analyzing and compressing the time-variant characteristics in historical information. The profit model based on mathematical constraints, can process time-variant future horizon output from prediction model to generate a flexible optimized recommendation for cleaning schedule. The effectiveness of the proposed system is validated in real farms and all data used in this paper is collected from real world. The two case studies in experiments show that the profit improvement can reach up to 6% and 30%, respectively. [Display omitted] • A rolling-horizon cleaning recommendation system for PV panels. • A novel long-term and nonlinear predictive method. • A concise profit model for easy deployment in industry. • Flexible cleaning schedule considering time-variant characteristics. • Improvements of 6% and 30% in two different real farms, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we applied the Dispersion Normalised Positive Matrix Factorisation (DN-PMF) approach recently proposed in the literature to provide a more realistic picture of the relative importance of emission strength vs. atmospheric dispersion conditions. The disentanglement of such effects is of great concern in pollution hot spots like the Po Valley (Italy), where particulate matter limit values are exceeded despite the existing abatement measures. To explore the potentiality of the DN-PMF approach – still scarcely applied in the literature – a well-chemically characterised PM 1 (atmospheric particles with aerodynamic diameter <1 μm) dataset comprising samples collected at different time resolutions at an urban background site (Bologna) in the southern Po Valley was used. Indeed, it is well known that shallow mixing layers promote pollutant accumulation but this observation is not enough to exclude an enhancement of emission strength which could be tackled by appropriate abatement strategies. The source apportionment of sub-micron sized aerosols having a quite long atmospheric residence time in a complex environment like the Po Valley - which is also strongly impacted by secondary aerosol formation on a basin-scale - is generally quite challenging when using receptor models. Due to the availability of a huge dataset with variables having multiple time resolutions, in this work the DN-PMF was implemented in a multi-time resolution approach (MT) to achieve a better source identification and to gain knowledge about the relative importance of atmospheric dilution vs. emissions. A comparison between results obtained by the application of the regular multi time resolution (REG-MT) vs. the DN-MT approach is presented here for the five factors identified (nitrate-dominated, sulphate-dominated, biomass burning, mineral dust, and urban aerosol). The first interesting outcome is that REG-MT and DN-MT results do not point at significant differences in temporal patterns for aerosol components and sources impacting at the basin-scale (i.e. sulphate- and nitrate-dominated aerosol, biomass burning) thus suggesting that the diel modulation of these PM 1 emissions is somehow masked by the stronger variability of the mixing layer. Conversely, contributions from local sources with more pronounced diel variation like traffic are quite well reproduced by DN-MT and the ambient concentrations are enhanced compared to REG-MT. This is an important piece of information highlighting that PM 1 concentrations from local sources have been likely underestimated by REG-MT assessments. To our knowledge, this is one of the very few applications of DN-MT and the first one at a European site where the huge effort made to implement air pollution containment measures is still not very much effective in reducing PM levels; moreover, in this paper a detailed discussion about the possible interpretation of the output of DN-MT in terms of temporal patterns is reported. [Display omitted] • High PM levels are due to atmospheric stability and emission strength; DN-PMF points out the source emission role. • Secondary aerosol-dominated factors showed a regional nature. • Urban aerosol factor was highly enhanced by dispersion-normalisation. [ABSTRACT FROM AUTHOR]

• We have collected almost all published dust obscured galaxies (DOGs) with the certain coordinate. • in the literature (817 DOGs in total) to investigate their infrared properties by using 2MASS. • (and other observations in the JHK bands), WISE, IRAS and Hershel data in this paper. We have collected almost all published dust obscured galaxies (DOGs) with the certain coordinate in the literature (817 DOGs in total) to investigate their infrared properties by using 2MASS (and other observations in the JHK bands), WISE, IRAS and Herschel data in this paper. Our study shows that objects with different types have different presentations for the relations between the redshift and infrared colors. It is also found that in the near infrared two-color diagram, DOGs are distributed across the blackbody line and the power law line indicative of the thermal emission from the stellar component and the star formation for some objects, and the AGN dominated for other objects in the near infrared. However, in the two-color diagrams with longer wavelengths the majority of DOGs are distributed around the power law line indicative of the central AGN dominated in the mid-infrared, far infrared, and submillimeter regions. We also compared the infrared color propertes between DOGs and ULIRGs. It is found that, statistically, ULIRGs have redder colors than that for DOGs in the near and mid- infrared region while compared with DOGs, ULIRGs are more near the blackbody line indicative of the star formation dominated in far infrared. [ABSTRACT FROM AUTHOR]

The paper presents experimental studies on the effect of sodium bicarbonate and calcium hydroxide dry, low temperature sorbent injection on the concentration and size distributions of precipitated particles (fly ash and sorbent particles mixture), fractional collection efficiency, and particles morphology. The measurements were carried out on a lab-scale system comprising unipolar electrostatic agglomerator and electrostatic precipitator. In the experiments presented in this paper, the sorbent was injected upstream of electrostatic agglomerator. Results of SEM studies revealed the process of sorbent and fly ash particles agglomeration. The measurement of resistivity of fly ash and sorbent mixtures have shown that injected sorbent has a large effect on the particles resistivity, when the temperature of dust cake is increasing. In practical situations, too high resistivity can lead to back corona discharge generation, while too low causes the particles re-entrainment; both of these phenomena can reduce the dust collection efficiency of an electrostatic system. [Display omitted] • Agglomeration of PM2.5 particles with particles >5 μm improves PM2.5 removal. • Dry sorbent injected to fly ash in flow provides new agglomeration collectors for PM2.5. • Dry sorbent injection upstream of agglomerator increases PM2.5 collection efficiency. • Dry-injected sorbent to fly ash flow has a large effect on resistivity of dust cake. • Synergistic effect of electrostatic agglomeration and precipitation was obtained. [ABSTRACT FROM AUTHOR]

• A new method to invert the complex refraction index (CRI) and particle morphology of non-spherical aerosols based on the full Stokes parameters of non-spherical aerosols is proposed. • The method has fewer limitations, and does not need to assume a function to describe the aerosol size distribution. It can invert the CRI and particle morphology for unknown non-spherical aerosol particles accurately. • A new Stokes parameters measurement system for non-spherical aerosol particles is designed. The full Stokes parameters and backscattering matrix of dust aerosols particles are measured and inverted. • The light scattering parameters calculated by the full Stokes parameters can be used for fine classification of particles of different morphology. The complex refraction index (CRI) and particle morphology of aerosols are the most important microphysical parameters of aerosols. They are related to the light scattering parameters of aerosols closely. However, the variation of polarization state of light scattering parameters of non-spherical particles is very sensitive to the CRI and particle morphology. In order to accurately obtain the CRI and particle morphology of non-spherical aerosols, a new method of inversion the CRI and particle morphology for non-spherical aerosols using the full Stokes parameters of non-spherical aerosols is proposed. In this paper, a new Stokes parameters measurement system for non-spherical aerosol is designed. The backscattering (180°) full Stokes parameters of the typical non-spherical aerosol (dust aerosol particle population) are measured. The CRI value of dust aerosols estimated using this method is consistent with those of the references. The feasibility of our retrieval method is confirmed. In this paper, the relationship between the dust aerosol CRI and the change of particle size during the dust settling process is investigated. The results show that the average CRI of dust aerosol does not vary with the particle size distribution in settling process. At the same time, the linear depolarization ratio and the ellipticity of backscattered polarized light of the dust aerosol particles are calculated using the full Stokes parameters. It is found that the non-spherical aerosol linear depolarization ratio and the ellipticity of backscattering polarized light are very sensitive to particle morphology. They can be used for fine classification of particles of different morphology in the dust aerosol particle population. [ABSTRACT FROM AUTHOR]

The safety of production and the health of on-site workers are greatly affected by dust pollution in metal mines. In recent years, wet-type and bag-type dust collectors with high efficiency have been widely used for dedusting. However, a series of problems exist, such as high resistance, and high energy consumption. This paper presents a review of the research and development regarding occupational hazards and dust control/removal methods in metal mines in China. First, it introduces the occupational hazards of dust in metal mines and discusses the pathogenic mechanism and sources of dust. Then, several dust control methods, including ventilation, sealed, spray, dust suppressant, and curtain dust isolation are examined. Additionally, this paper discusses the difficulties in the development of dust control in China. Finally, some valuable suggestions are made for future development on dedusting measures in metal mines. This review provides references for scientific and green mining in China. [Display omitted] [ABSTRACT FROM AUTHOR]

• A cloud-edge collaborated dust deposition degree monitoring scheme for distributed PV systems. • Classification using temporal and interactive information of PV arrays. • Improved scheme adaptivity by training model with randomly grouped data. • The classification accuracy reaches 98% verified by 201,600 sets of real data. After installation, the long-term efficient operation dominates the profitability of photovoltaic (PV) generation systems. Unlike large-scale PV plants, distributed PV systems are relatively dispersed, and belong to different owners, whose main obstacle for maximizing the profit is the lack of professional maintenance. This paper therefore proposes a cloud-edge collaborated dust deposition degree monitoring scheme for distributed PV systems without employing additional equipment, sensors or meteorological data, which just assumes the operational and historical data of all distributed PV systems in the same area to give the guidance whether the distributed PV system needs cleaning. In implementation, temporal and interactive models are established based on the operation characteristics of distributed PV systems, whose overall classification accuracy could reach more than 98%. In addition, in order to improve the adaptivity of monitoring scheme, this paper proposes a data-based random grouping method, which avoids the model mismatch caused by the addition or withdrawal of PV arrays. Finally, experimental verifications are carried out to prove the effectiveness of the presented scheme. © 2017 Elsevier Inc. All rights reserved. [ABSTRACT FROM AUTHOR]

MAXI J1421–613 is an X-ray burster discovered by Monitor of All-sky X-ray Image (MAXI) on 9 January 2014 and is considered to be a low-mass X-ray binary. A previous study analyzing follow-up observation data obtained by Suzaku on 31 January to 3 February 2014 reported that an annular emission of ∼ 3 ′ – 9 ′ radius was found around the transient source. The most plausible origin of the annular emission is a dust scattering echo by the outburst of MAXI J1421–613. In this paper, we confirm the annular emission by analyzing the data of the Swift follow-up observation which was conducted by the photon counting mode on 18 January 2014. In a radial profile, we found an annular emission at ∼ 2 ′. 5 – 4 ′. 5. Its spectrum was well explained by an absorbed power law, and the photon index was higher than that of MAXI J1421–613 itself by Δ Γ ∼ 2. The flux and radius of the annular emission observed by Swift are explained by dust scattering of the same outburst as is responsible for the annular emission observed by Suzaku. Assuming that the dust layer causing the annular emission found by Swift is located at the same position as the CO cloud in front of MAXI J1421–613, the distance to the transient source was estimated to be ∼ 3 kpc, which is consistent with the value estimated by the previous study of Suzaku. [ABSTRACT FROM AUTHOR]

Mode division multiplexing (MDM) is an emerging information transmission technique in which multiple data signals can be transmitted simultaneously on different modes of a single wavelength laser beam over a free-space channel. MDM is a potential technique for the realization of high-speed spectral efficient communication links for future generations of wireless networks. We present a novel MDM-based free-space optics (FSO) system. The system integrates a 3D hybrid modulation scheme produced by combining carrier suppressed-non-return-to-zero (CSNRZ), differential quadrature phase-shift keying (DQPSK), and polarization shift keying (PolSK) modulation schemes for beyond 100 Gbps applications. Three unrelated 40 Gbps data signals are modulated and transmitted on one optical carrier utilizing three distinct signal properties: amplitude (CSNRZ), phase (DQPSK), and polarization state (PolSK). The proposed 3D modulation scheme offers a high-capacity system, where each channel transmits 4 Gbps as compared to 1 Gbps in the case of OOK modulation. MDM using distinct Hermite Gaussian modes: (HG00 and HG01) of a laser beam is incorporated to boost the spectral efficiency and information rates of the FSO link. The proposed 120 Gbps single-channel MDM-FSO link performance is examined under the impact of different levels of dust and fog environmental conditions using quality factors and received eye diagrams as the performance metrics. This system achieved optimal performances up to 1250 m (very light dust), 540 m (light dust), 170 m (moderate dust), 750 m (low fog), and 425 m (medium fog). In the worst-case scenario, the system manages to work up to a 67 m range in dense dust with a maximum attenuation of 297.38 dB/km and a 200 m distance in heavy fog with only 90 dB/km attenuation which is less than 1/3rd of the attenuation measured for dense dust event. In addition, our results and the case studies confirm that dust introduces greater signal attenuation than fog. Therefore, an encounter with a dust environment should be considered as the bottleneck issue for FSO links. The creative contribution of this paper is to put forward a bandwidth-efficient MDM-FSO-enabled B5G system that could be deployed in harsh and challenging locations at reduced visibility. This is expected to be further technically sustainable owing to the use of advanced 3D hybrid optical orthogonal modulation and therefore find use in implementing 5G and 6G cellular and data networks. [ABSTRACT FROM AUTHOR]

An accurate evaluation of the dust accumulation on photovoltaic (PV) panels enables the development of cleaning plans and improves the grid connection security of PV power stations. In this paper, a novel image enhancement algorithm is proposed to evaluate the dust accumulation on PV panels. An atmospheric scattering model was used to analyze the difference in the image characteristics of clean and dusty PV panels. A model was proposed to describe the relationship between the model coefficient and the dust level by minimizing the pixel difference between the images of the soiled and clean PV panels. An experiment system was designed to acquire the images of clean and soiled PV panels with different dust levels. The model parameters were determined by data fitting, and the model's generalization ability was improved by adding a noise item. The results show that the model can estimate the dust level on PV panels with an accuracy of 83.78%. The average root mean square error (RMSE) of samples 1–4 is 1.67, and the error range is 2–3.5 g/m 2. In addition, the proposed method has higher accuracy than the optical attenuation and weighing methods, with a mean absolute error (MAE) of 1.61 g/m 2. The method is simple and reliable for intelligent cleaning of PV panels. [ABSTRACT FROM AUTHOR]

Coal mine production links will produce dust, which not only pollutes the environment but also endangers the health of coal miners. When the dust concentration is too high, it may cause serious accidents such as dust explosion. Dust removal in coal mines is extremely important. Based on the Extension set theory of Extenics and on the basis of analyzing the working principle and technical characteristics of commonly used dust removal methods, this paper proposes an Extension data mining method for in-depth analysis using environmental open data and large data collected by various sensors, mining measures for intelligent dust removal and worker health protection in coal mines, and illustrates its application strategies with examples. As a new technology of intelligent dust removal, the development trend of Extension data mining and the innovation direction in future applications are prospected. [ABSTRACT FROM AUTHOR]

• NH 4 H 2 PO 4 curbs LDPE deflagration by inhibiting C 2 H 4 generation and consumption. • Species of deflagration products and free radicals were counted using ReaxFF MD. • Traced the production and consumption pathways of the major intermediate C 2 H 4. • Mechanism of NH 4 H 2 PO 4 inhibition of C 100 H 202 deflagration flame spread revealed. In this paper, the inhibition effect of ammonium dihydrogen phosphate (NH 4 H 2 PO 4) on the deflagration of polyethylene dust (C 100 H 202) is studied by combining experimental tests with reaction molecular dynamics simulation (ReaxFF MD). The mechanism by which NH 4 H 2 PO 4 inhibits C 100 H 202 deflagration is revealed at the microscopic level. The experimental results demonstrate that the inhibition effect of NH 4 H 2 PO 4 on C 100 H 202 deflagration is positively correlated with its concentration, and the addition of NH 4 H 2 PO 4 equivalent to 50 % of the mass of C 100 H 202 can completely suppress the deflagration. The apparent activation energies for the decomposition of C 100 H 202 and C 100 H 202 /50 %NH 4 H 2 PO 4 are calculated using ReaxFF MD to be 97.11 kJ/mol and 124.78 kJ/mol, respectively, which are in agreement with the results obtained from thermogravimetric tests. Furthermore, ReaxFF MD is employed to calculate the types and quantities of deflagration products and free radicals before and after the addition of NH 4 H 2 PO 4. The results indicate that the number of the main intermediate C 2 H 4 decreases with the increasing addition of NH 4 H 2 PO 4. Based on this, the generation and consumption pathways of C 2 H 4 are traced. It is found that phosphorous groups such as HOPO and PO 2 scavenge active free radicals like ·O and ·OH, thereby altering the formation and consumption pathways of C 2 H 4 , leading to a reduction in both its formation and consumption. Additionally, H 2 O and inert gases produced by the thermal decomposition of NH 4 H 2 PO 4 also contribute to inhibiting the progression of C 100 H 202 deflagration. [ABSTRACT FROM AUTHOR]

The excessive concentration of dust in fully-mechanized excavation face (FEF) poses a serious risk to the health and safety of workers. This paper proposes a novel dual swirling air curtain (DSAC) dust-control system and conducts similar experiments to evaluate its effectiveness. Firstly, the theory of annular swirling jet and the dust-control mechanism of DSAC are elaborated upon. The subsequent section presents a comprehensive description of the proposed DSAC, outlining its design and the theoretical computations involved. Thereafter, the formation and attenuation of the air curtain, as well as the dust diffusion patterns with and without the DSAC system, are investigated using a similar experimental platform. The results showed that the DSAC can produce a clockwise rotating swirling air curtain. Furthermore, the utilization of the DSAC can effectively mitigate dust concentration on the experimental platform and suppress dust diffusion. • A novel dual swirling air curtain dust-control system is proposed. • Airflow field and dust filed experiments are performed on similar test platform. • The proposed system can effectively mitigate the dust concentration. [ABSTRACT FROM AUTHOR]

This paper introduces an optical power ring model for calculating the efficiency of fiber coupling. The model obtains more accurate results than the Gaussian model. This model compares the coupling efficiency of large core and standard multimode fiber and demonstrates that the tolerance of the large-core multimode fiber to the coupling misalignment and dust contamination is higher than that of the standard multimode fiber. • A model for calculating the fiber coupling efficiency in VCSEL-MMF links has been proposed. • The model is verified by experiments. • The tolerance to radial offset and dust contamination of MMF and LCMMF has been compared. [ABSTRACT FROM AUTHOR]