Dust Mitigation Research Articles

Development of a scenario-based approach using game theory for the restoration of Hawizeh Marsh and dust mitigation

ABSTRACT The exploitation of water from the Main Outfall Drain (MOD) canal together with the water from the Tigris River can be considered an effective solution to reduce the water consumption from the Tigris River by Iraq’s agricultural sector. This extra outflow can be used to restore Hawizeh Marsh and improve/control the consequent environmental problems (including dust storms) across the region. Accordingly, this study presents an efficient water resource management framework based on a game theory model to calculate the amount of agricultural drainage water available for exploitation in MOD, which can be integrated with the Tigris River water for agricultural irrigation. Different conjunctive water use scenarios were evaluated through a non-cooperative game theory model. The proposed optimum scenarios, in addition to supplying this wetland’s water rights and consequently mitigating its environmental problems, can also perfectly meet the water demand of farmers in terms of both quantity and quality.

QEMSCAN® automated mineralogical analysis of PM2.5 and PM4: A preliminary study of underground coal mine dust from Poland and Slovenia

Determining the physical and chemical properties of airborne dusts in occupational settings is essential for assessing their potential toxicity as well as the effectiveness of respiratory protective equipment and dust mitigation measures. Here, we report the first successful QEMSCAN® automated mineralogical analysis of potentially toxic PM4 and PM2.5 dust from deep coal mines in Poland and Slovenia. QEMSCAN® was setup to automatically delimit 100,000 ‘particles’ per sample, based on average atomic number contrast, subject these to X-ray elemental analysis at points in a grid pattern (0.5 µm spacing), assign a mineral name to each point and then output the results as particle size, shape, mineralogy and mineral associations data and as mineral maps. The dusts were prepared as dispersions on a polyethylene sheet so that coal particles, with a slightly higher BSE signal, could be recognized from their substrate. Samples were analyzed repeatedly and in different orientations to determine the effects of sample geometry and topography. QEMSCAN® mineral identifications were manually checked using standard SEM X-ray elemental analysis. From a pilot study of Polish and Slovenian coal dust samples, PM4 and PM2.5 contain varying proportions of coal, quartz and other silicates, sulphides, sulphates, carbonates, oxides and other minerals, and notable concentrations of fly-ash particles. That some of these components may be toxic when inhaled, particularly the quartz and fly-ash, highlights the need for larger scale and wider ranging studies. The further potential of the newly developed QEMSCAN® methodology is discussed.

Dust mitigation by the application of treated sewage effluent (TSE) in Iran

Considering the presence of 274 dusty days in 2021 in Zabol city, Iran, the present study aimed to evaluate the feasibility of using treated sewage effluent (TSE) for dust mitigation with natural methods of increasing land cover. Hence, first of all, the identification of sewage treatment facilities along with the volume and chemical status was carried out and compared to the various national and international legislation. Then, field investigation on land use and land cover, along with literature review on dust origins, sand detachment areas, and sand corridors in the study area will be assisted for optimal area suggestion. Note that, in the present study it was assumed that the application of TSE for wetting the surface to vegetation restoration resulted in wind erosion control in critical foci. The results showed that, so far, a total of 39,000 m3/day could be treated, in the whole study area. The TSE volume calculated based on two scenarios consisting, (1) data obtained from the related organization, and (2) based the capacity of the wastewater plant is 2.8 and 5.1 mcm/year, respectively. Additionally, the study of TSE quality and its comparison to various regulation such as FAO, USEPA, INS, and CWQI indicated the applicability of transforming TSE to 14 km away from the WWT planet daily for rehabilitation of Hammon Hirmand through irrigation of T.stricta to increase the vegetation cover to above 30%.

An infrared based dust mitigation system operated by the robotic arm for performance improvement of the solar panel

Solar panel is one of the key elements to extract the electrical energy from solar energy for end use. The performance of solar panels is affected by the dust accumulation, which is one of the serious concerns for the decrement in the solar panel output. A suitable cleaning technique can be useful to overcome this problem. Thus, to mitigate the dust effect on the solar panel surface, a robotic arm based self-automated dust removal system is designed and developed. A novel IR sensor-based cleaning technique is utilized, which performs multitasking operation for early morning shadow-free cleaning, day-to-night shifting, overheating observations and movement of robotic arm. The proposed wet cleaning mechanism offers a Silicone rubber based wiping function carried out by a PWM operated motor of robotic arm. The IEEE 1149.1 compliant embedded controller (C8051F226DK) is incorporated to control the whole system. The experimental work on a 30 WP system can produce the average value of 11.88 % of energy increase, 13.02 % of PV module efficiency and 81.35 % of performance ratio after 2.4 months (73 days) cleaning in winter season. The device works at higher cleaning rate (1.86 m2/s) with less water (0.31 L/m2) consumption. A comparatively light weighted (520 g) device provides low power cleaning operation and offers low cost (1.84 $/kW) per cleaning cycle. It is concluded that the upgradability and user-friendly operation of this indigenous device make it competitive among other cleaning solutions. The proposed technique is more suitable in terms of its operation, electrical and economic performance.

Influence of seasonal effect on dust accumulation on Photovoltaic panels that operate light posts

Dust accumulation on Photovoltaic (PV) panels is a severe threat that decreases the energy production of PV panels and therefore, lowers their efficiency especially in the Middle East and North Africa (MENA) region. Cleaning of the PV panels has always been a challenge for most of the countries in this region due to scarcity of water resources and high dust accumulation rates throughout the year. A new dust mitigation technique has been developed in this research, which consists of a wind shield, antistatic hydrophilic coating and a mechanical vibrator. The objective of this research is to study the seasonal effects on the performance of this new dust mitigation technique for PV panels that operate street light posts. Two experiments were conducted for six weeks in 2021; the first one was in winter while the other one was in summer. In both experiments, two PV panels were examined. The first PV panel is used as a reference panel for comparison and the second panel is provided with a wind shield and a mechanical vibrator, in addition to being coated with an antistatic hydrophilic coating. The function of the wind shield is to obstruct the wind coming from the South direction. The antistatic coating prevents the dust particles from adhering to the panel’s surface. The role of the mechanical vibrator is to shake off the deposited dust particles on the panel’s surface. The experimental results show that applying the antistatic coating together with the wind shield with vibrating the panel in case of the winter experiment preserved the efficiency of the panel, such that the drop in efficiency did not exceed the maintenance limit of 10% during the experiment. While in the summer experiment, the maintenance limit has been exceeded in the fifth week. This is mainly due to the effect of wind direction and rainfalls, which were present in the winter, unlike the summer experiment where winds and rainfalls are rarely found. This clearly shows that the combination of the wind shield and the mechanical vibrator together with the coating is a promising dust mitigation technique for PV panels operating light posts especially in winter.

Jordan Space Research Initiative: Societal Benefits of Lunar Exploration and Analog Research

Jordan's political stability has aided in the country's notable rapid growth these past few years, despite its limited natural and financial resources. Jordan is currently taking the lead in multiple sectors in the region, such as Education, Medicine, Information and Communications Technology, and more. The advancement of these industries has encouraged the progress and development of the Jordanian community as well. Similarly, space can contribute societal benefits in an emerging space country like Jordan. Under the Moon Village – Participation of Emerging Space Countries (MV-PESC) program, a roadmap for Jordan's contribution to lunar exploration and the Jordan Space Research Initiative (JSRI) were created. This 20-year roadmap focuses on establishing an analog R&D facility for Moon and Mars in the Jordanian desert of Wadi Rum, locally known as the Valley of the Moon. This roadmap aims to support the following building blocks: Water Resource Management, Renewable Energy, In-situ Resource Utilization (ISRU) and Robotics, Dust Mitigation, Agriculture, Smart City Infrastructure, and Women's Health. These building blocks will advance research required for the Moon Village, while simultaneously contributing to sustainable development in Jordan. Due to the national importance which Wadi Rum holds, for being a tourist attraction site, a naturally protected area, and a homeland for the local nomadic tribes (The Bedouins), community engagement is a crucial aspect of this roadmap. Finding an appropriate way of approaching the local community in Wadi Rum, the general public in Jordan, local authorities and the government, as well as fostering international cooperation in the space community, is crucial to its success. This paper investigates how the implementation of the Moon Village PESC project in Jordan, as embodied by JSRI, will contribute to solving some of its most pressing societal and economic issues, such as water scarcity, while highlighting how the incorporation of space technology and research will play a major role in advancing Jordan's existing research goals and initiatives. By linking the roadmap developed by JSRI to the preliminary Roadmap for Space and Sustainable Development (RSSD), which was introduced in a previous IAC paper titled “Jordan and the United Nations Space2030 Agenda: A Roadmap for Space and Sustainable Development” (2020), this paper also identifies ways in which the implementation of the Moon Village in Jordan will contribute to the achievement of the objectives of the UN Space2030 Agenda and the Sustainable Development Goals.

Dust removal from a variety of surface materials with multiple electron beams

Dust mitigation is one of the technical challenges to overcome for future lunar surface exploration. In our previous work, a new electron beam (e-beam) mitigation technology was introduced to remove dust particles from protected surfaces through an electrostatic mechanism developed based on a Patched Charge Model. This model shows that the emission and re-absorption of e-beam induced secondary electrons inside microcavities between dust particles can result in large charges on the particles and their subsequent ejections from the surface due to strong repulsive forces. It was shown that, due to random orientations of microcavities, varying the e-beam incident angle by rotating the sample surface can cause more microcavities to be exposed, thereby improving the cleaning effectiveness. In this paper, we present and test a new configuration to implement varying the beam angle. Here multiple e-beam sources are aimed at different angles simultaneously at a sample surface that is fixed in place. A large variety of surface material samples are tested to demonstrate the e-beam technology's application scenarios, including both insulating samples (spacesuit, glass, a photovoltaic (PV) panel, Kapton tape, thermal blanket and anodized aluminum) and a conducting sample (aluminum). It is shown that the multiple e-beam source configuration improves cleaning effectiveness by 10–30% in comparison to a single fixed beam and sample. Most of the insulating samples achieve 80–90% cleanliness after only the 2–3 min beam exposure, except for the PV panel that shows 50% cleanliness. The conducting aluminum sample shows relatively low cleanliness at 35–45% likely due to the attractive Coulomb mirror force between the charged dust and aluminum surface. Finally, various e-beam configurations are suggested depending on application scenarios.

Designing a grain dust simulator for dusty environments in typical grain bins in the Midwestern United States

Grain dust represents a significant health risk to grain farmers and workers. Exposure to grain dust can diminish lung function as well as cause respiratory diseases. Grain storage facilities are considered agricultural confined spaces with high concentrations of grain dust. On-farm research for dust sample measurements is time consuming and cost prohibitive. The objective of this research was to design, build, and test a grain dust simulator (GDS) to simulate the dusty environments of grain storage bins in a laboratory setting whereby different types of grain dusts with various environmental conditions (airflow, temperature, and humidity) could be studied. The GDS, a 1/10th scale bin model, was designed with similar ventilation and auger systems as an on-farm grain bin with a diameter of 15.24 m and a capacity of 1762 m 3 . Dust concentration data collected from farms in Ohio, USA were used to guide the development of the GDS. Feasibility and performance tests verified that the GDS designed can be used as a testing platform for simulating the dusty environment in grain bins and development of effective respiratory protection for farmers under various on-farm conditions. • Grain dust simulator designed, built and tested. • Design simulates the respirable dust environment in on-farm grain bins. • Simulator a testing platform for dust mitigation strategies. • Also, simulator a testing platform for respirable protection equipment.

Working with lunar surface materials: Review and analysis of dust mitigation and regolith conveyance technologies

The Moon's dusty surface environment threatens any equipment that operates there, especially for long-duration infrastructure needed for a sustained lunar presence. This is doubly true for systems that convey regolith, which by agitating the soil are certain to generate dust. Here, we provide a comprehensive review of technologies that have been proposed to convey regolith on the lunar surface, and to mitigate against dust hazards that are generated by such transport systems. We define functional taxonomies for both regolith conveyance and dust mitigation, then carry out quantitative trade studies in several categories for each. Examples include passive and active dust mitigation, and horizontal and near vertical conveyance. Conveyance technologies that scored particularly high include wheeled haulers, conveyor belts, and auger/hopper transfer points. High scoring dust mitigation technologies include the lotus leaf passive coating, Electrodynamic Dust Shield, and boots or bellow made of fiberglass fabric. We also explore novel or unconventional concepts and describe how dust mitigation and regolith conveyance can be combined using a systems approach with multiple technologies layered together. The results from the trade studies and the subsequent recommendations constitute a practical guide that can be used for designing and developing systems that must perform efficiently and reliably to carry out useful tasks on the Moon or Mars, such as resource extraction, construction, and additive manufacturing.

A novel dust mitigation technology solution of a self-cleaning method for a PV module capable of harnessing reject heat using shape memory alloy

Most large-scale solar photovoltaic (PV) systems are installed in remote and desert areas, where large land areas and sunlight are available throughout the year. However, major environmental degradation factors exist in the form of soiling and dust accumulation, primarily when operating PV systems in desert lands. In this study, an innovative method for dust mitigation of a PV panel surface is introduced using an SMA wire actuator. It utilizes unwanted heat energy at the back surface of a PV panel and converts it into effective mechanical energy using a unique thermo-mechanical property in SMA materials. Results of the indoor test, using a sun-simulator instrument, prove the effectiveness of harnessing the reject heat at the back surface of a PV panel toward the activation of an SMA-based PV cleaning system. Experimental results demonstrated the successful reach of the SMA activation temperature of about 60 OC, for an applied solar irradiance power of 1200 W/m2, within a test duration of 40 min. This allowed generating a desirable mechanical displacement based on the harnessed rejected heat for the operation of the cleaning system. The overall performance of the fabricated system was analyzed and evaluated to highlight the achieved cleaning process and its effectiveness.

Anthropogenic Sources Dominate Foliar Chromium Dust Deposition in a Mining-Based Urban Region of South Africa.

Dust pollution can be severe in urban centers near mines and smelters. Identification of dust sources and assessing dust capturing plant morphological traits may help address the problem. A chromium (Cr) mining and ferrochrome smelting region in Sekhukhuneland, South Africa, was investigated to identify the sources of Cr in soil and plant leaf surfaces and to evaluate the association between Cr sources and plant morphology. Combinations of bi- and multivariate statistical analysis techniques were applied. Non-significant relation between Cr quantities in surface soil and on leaf surfaces suggested negligible Cr dust contribution from soil to leaves. Association among Cr, Fe, Mg, Al, and Si levels on leaf surfaces confirmed their shared origin, possibly from chromite containing dust dispersed by mines, smelters, roads, and tailings. Both plant morphology and Cr sources (number and proximity to mines and roads) conjointly determined Cr dust deposition on leaf surfaces. Air mass movement patterns further identified local polluters, i.e., mines, ferrochrome smelters, and roads, as dominant dust sources in the region. Common plant species showed Cr dust adhesion favouring traits (plant tallness, larger leaf area, dense epicuticular wax structures, and larger stomata) and projected dust mitigation prospects for Sekhukhuneland.

Water droplet behavior in between hydrophilic and hydrophobic surfaces and dust mitigation.

An innovative method is introduced for environmental dust mitigation from a hydrophobic surface by a sessile water droplet. The sessile water droplet is located between two parallel plates having hydrophilic (at the top) and hydrophobic (at the bottom) states. The water droplet is located at the top hydrophilic plate, and the effect of the plate spacing on dust mitigation rate is examined. The droplet behavior is analyzed for different plate spacings and various droplet sizes using a high-speed camera. The fluid and the particle motions are simulated inside the droplet while adopting the experimental conditions. The findings demonstrate that the sessile droplet can effectively mitigate dust. Reducing the plate spacing increases the droplet meniscus diameter and enhances the dust removal rate. The surface tension force on the hydrophilic surface remains greater than that of the pinning force on the dusty hydrophobic surface even though the Magdeburg and surface tension forces contribute to the droplet pinning force on the hydrophobic dusty surface. Flow current is developed in the droplet fluid during the squeezing period, which considerably enhances the dust removal rate from the hydrophobic surface. The cleaned area increases with the droplet volume and plate spacing. Stria patterns are observed on the circumference of the dust-removed area. The present study provides a detailed analysis of a new method of dust removal from surfaces for self-cleaning applications.

Novel Policies are Required to Reduce Pediatric Lead Exposure from Legacy Lead (Pb) in Soil and Air

In 1925, a U.S. conference on lead (Pb) additives tacitly approved their use in petrol. Over five-decades an exponential increase of air lead occurred from commercial marketing of leaded petrol and the sale of automobiles. The ability to measure microgram quantities of Pb was unavailable to medical researchers until the late 1960s and early 1970s. The clinical application of advanced analytical technology demonstrated that pediatric lead exposure was excessive. Beginning in the mid-1970s, actions were taken to curtail Pb additive and decreases of pediatric lead poisoning coincided with decreased air Pb from leaded petrol use. Exogenous Pb exhaust particles are absorbed through inhalation and ingestion routes of exposure. Exogenous Pb is metabolically mistaken for calcium and stored endogenously in bones, teeth, and other tissues. Endogenous Pb has intergenerational effects. All organs, most notably the nervous system, are affected. Clinical studies indicate that there is no safe level of Pb exposure. A worldwide ban on leaded petrol was achieved on August 30, 2021. Banning leaded petrol corresponded with marked decreases in lead exposure. However, exogenous Pb dust persists in soil as a legacy from the era of leaded petrol. Soil Pb is remobilized into the air. Because of traffic congestion and Pb dust emissions, population centers are of particular concern. An exceedingly strong association exists between soil Pb and blood Pb indicating that at the community-scale Pb dust mitigation is necessary to decrease pediatric Pb exposure. Urban soil Pb and blood Pb studies indicate the risk of excessive exposure from legacy Pb dust in communities is highest where the median soil Pb is ≥ 50 mg/kg. The objective of this article is to demonstrate the practical application of an advanced hand-held analytical instrument to map Pb in children’s playgrounds adjacent to a major traffic corridor. We illustrate soil Pb mapping and then consider mitigation procedures for primary prevention of legacy Pb. Mapping soil Pb provides an informed basis for advising parents and encouraging community mitigation responses for reducing pediatric Pb exposure from legacy Pb dust. The soil health-plant health-animal/human health signaling nexus is compromised by legacy Pb. For the medical pediatric community, the existence of legacy lead requires new policies to address intervention of the soil-air-blood linkages of the Pb exposure pathway.

Respirable Dust and Respirable Crystalline Silica Concentration in Workers of Copper Mine, Mongolia

Introduction: Prosperity in the mining industry in Mongolia has led to an increase in the number of mining workers, resulting in an increase in occupational exposures and the prevalence of occupational diseases and disabilities. The aim of this study was to assess the personal exposure of workers to respirable dust (RD) and respirable crystalline silica (RCS). Method: A cross-sectional study was conducted at the Erdenet Copper Ore Mining and included 581 personal samples of RD and 324 samples of RCS, collected in 2018-2020. Results: The study results revealed that the geometric mean (GM) of RD was 0.35 mg/m3 (95% CI 0.32 - 0.39). The RD concentration in 5.9% (n = 34) of all the samples exceeded the permissible exposure level (PEL) (3 mg/mg3). The GM of RCS was 0.012 mg/m3 (95% CI 0.010 - 0.016). In total, 12.0% (n = 39) of all RCS sample concentrations exceeded the PEL (0.1 mg/m3). Conclusion: Steel smelters, blasters, welders, and maintenance laborers were exposed to RD, while crushers, operators, drilling machinists, and maintenance laborers were exposed to RCS. Therefore, regular monitoring of the work environment, risk-based health examinations for dust-exposed workers, efficient support for dust mitigation, reduction measures at the source, and engineering controls are needed.

Mitigating Dust Pollution from Construction Activities: A Behavioural Control Perspective

Construction sites constitute major sources of pollutants creating negative impacts on the environment. Sustainable construction aims at mitigating these negative externalities while promoting economic and social outcomes. Dust pollution in construction sites is an invisible hazard, which is often ignored as little more than a nuisance. Although behavioral control is a popular way of preventing dust generation, past research has paid little attention to worker behavior regarding dust mitigation. This study aims to test a model that predicts intentions to alter the conduct of workers towards dust control in construction activities. This study adopted a questionnaire survey design with construction participants in Sri Lanka, using structural equation modelling to test several hypotheses based on the Norm Activation Model. The results proved that awareness of consequences and ascription of responsibility could have a positive impact on personal norms, which in turn could influence the behavior of site employees. The study also provided new insights on employees’ awareness of dust hazards, their sense of responsibility for its control, and the importance of their company. Policymakers and practitioners are recommended to pay more attention to how to harness worker’s support to mitigate dust pollution, and construction companies should initiate educational campaigns to raise awareness about environmental impacts, to influence personal norms of the workers in building sites. This research contributes to the body of knowledge by enhancing our understanding of factors influencing employees’ dust control behavior.

A novel method for dust mitigation from PV cell surfaces

A novel method is introduced eliminating dust from PV cells by rolling droplets. Since hydrophobizing of PV cell surfaces reduces the optical transmittance, hydrophobized meshes are adopted laying over PV cell surfaces towards reducing the coverage area of hydrophobized coating over cell surfaces. Droplet rolling and droplet fluid spreading conditions on PV cell surfaces are evaluated and the mesh size resulting in droplet rolling over the PV cell surface is incorporated in the experiments. Droplet dynamics over the hydrophobic mesh laid dusty PV cell surfaces are examined incorporating the high-speed recorded data. Findings reveal that rolling droplets mitigate dust from hydrophobic mesh-laid PV cells surfaces without leaving droplet fluid residues on PV cell surfaces. During dust mitigation, droplet fluid interacts with dust via infusion, which slightly reduces the translational velocity of the rolling droplet. PV cell output reduction becomes less (almost 11%) for the hydrophobic mesh laid surface than that of hydrophobized cell surfaces after dust removal by rolling droplets.

Improvement of the electron beam (e-beam) lunar dust mitigation technology with varying the beam incident angle

Dust hazards are considered to be one of the technical challenges for future lunar exploration. In our past work a new dust mitigation technology was introduced utilizing an electron beam to remove dust particles from various surfaces. This technology was developed based on a patched charge model, which shows that the emission and re-absorption of electron beam induced secondary electrons inside microcavities between dust particles can lead to sufficiently large charges on the dust particles, causing their release from the surface due to strong repulsive forces. In this paper an improvement in the effectiveness of this technology is demonstrated with varying the beam incident angle on dust-covered sample surfaces by rotating the samples relative to the beam. Due to random arrangements of the microcavities, more of them will be exposed to the beam with various incident angles, thereby causing more dust release from the surface. The cleaning performance is tested against three samples: glass, spacesuit, and a photovoltaic (PV) panel. Lunar simulant (<25 μm in diameter) is deposited onto the sample surfaces such that the initial cleanliness of the samples is 0 % (full dust coverage) and 40 %. Varying the beam incident angle shows an overall surface cleanliness increase of 10–20 % in addition to the cleanliness achieved with a fixed beam angle. The ultimate cleanliness reaches 83–92 % for the glass and spacesuit samples. The PV panel coated with MgF2 is shown to be more adhesive to the dust with the maximum cleanliness of 50–63 %.

An experimental investigation on condensation-induced self-cleaning of dust on superhydrophobic surface

The self-cleaning of the superhydrophobic surface (SHS) attracted worldwide interest. However, in most cases it depends on the incoming droplet, which places additional constraints especially in arid area and/or narrow space. Herein, a condensation-induced self-cleaning of dust on the SHS is proposed. First, the SHS are prepared and dust is deposited on the surface, and then the dust removal process is studied on the condensation visualization platform. During condensation, a liquid bridge is initially formed at the contact points between particles on the SHS, which governs dust removal behavior. Specially, three consecutive processes are accounted for the self-cleaning including dust agglomerating, condensate sliding and rolling as the condensate prolongs. As far as the sizes and coverage rate of dust particles are concerned, over 95% of particles can be removed by condensation within 90 min (air temperature 26 ± 0.5 ℃, air humidity 60 ± 5% and cooling-stage temperature 10 ± 0.5 ℃). This study aims to provide a useful, in-depth understanding of dust mitigation by condensation on SHS, which has potential application in PV module and heat exchanger.

Solution Crystallization of Polycarbonate Surfaces for Hydrophobic State: Water Droplet Dynamics and Life Cycle Assessment towards Self-Cleaning Applications.

Polycarbonate sheets are optically transparent and have the potential to be used as one of the cover materials for PV applications. Solution treatment of polycarbonate surfaces enables to create surface texture topology giving rise to a hydrophobic state, which is favorable for self-cleaning applications. In the present study, hydrophobization of polycarbonate surface is investigated via crystallization of surface by a one-step process. The influence of texture topology, which is created via crystallization, on water droplet mobility and optical transmittance is examined. Findings revealed that solution treatment, using acetone, results in crystallized polycarbonate surfaces with a hydrophobic state. Depending on the treatment duration, the texture characteristics of crystallized surface change while influencing the water contact angle hysteresis. This in turn affects the droplet mobility over the inclined crystallized surface and alters the UV visible transmittance. Moreover, the droplet mobility improves and dust mitigation rates from the treated surface increase as the solution treatment duration are reduced to 2 min. Oil impregnated samples result in improved UV visible transmittance; however, droplet motion changes from rolling to sliding over the surface. A sliding water droplet enables the removal of the dust particles from the oil-impregnated sample surface.

On the Mechanism of Human Saliva Interaction with Environmental Dust in Relation to Spreading of Viruses.

Environmental effects such as dust mitigation can amplify the spread of viruses via inhaling infected dust particles. Infusion and the spreading rate of human saliva over the dust particles can play a critical role in contiguous virus spread. In the present study, mechanical and chemical interactions of human saliva with environmental dust particles are considered. The saliva droplet impact on dust particles is examined while mimicking saliva droplet spreading during coughing in a dusty ambience. The mechanisms of saliva infusion and cloaking on the dust particles are explored. The characteristics of saliva droplet normal and oblique impacts on a dust particle are examined experimentally and numerically to evaluate the amount of saliva residues on the impacted particle surface. The findings reveal that the saliva liquid infuses and cloaks the dust particle surfaces. The saliva droplet impact on the dust particles leaves a considerable amount of saliva residues on the impacted surfaces, which remain undried for a prolonged period in indoor environments. Weak adhesion of the saliva-infected dust particles on surfaces, such as glass surfaces, enables saliva-infected dust particles to rejoin neighboring ambient air while possessing a high potential for virus spreading.