Simulated Weather Conditions Research Articles

Weathering words: a virtual reality study of environmental influence on reading dynamics.

Reading is a fundamental cognitive activity that is influenced by both textual and external environmental factors, although the latter has been less thoroughly explored. This study aims to examine the impact of environmental visual conditions on reading performance using Virtual Reality (VR) technology. We conducted two experiments to assess the effects of visual contrast and simulated weather conditions on reading dynamics. In Experiment 1, we measured single-word recognition speed using a lexical decision task under different visual contrasts and weather conditions. In Experiment 2, we assessed reading dynamics during a sentence reading task, analyzing how visual contrast and simulated sunny versus rainy weather conditions affected reading behavior, particularly focusing on reading speed and eye fixations. In Experiment 1, high visual contrast, particularly under sunny conditions, significantly enhanced single-word recognition speed, indicating a notable influence of environmental visual conditions. In Experiment 2, visual contrast had minimal effect on sentence reading; however, sunny weather facilitated faster reading times, while rainy scenarios increased the number of eye fixations. These findings suggest that environmental factors, such as weather conditions, can significantly affect reading behavior. The study contributes to the understanding of key environmental influences on reading in everyday life contexts and has implications for the ergonomic design of reading materials, especially for outdoor settings and VR environments. Additionally, the integration of controlled stimuli within VR increases the ecological validity of reading research, underscoring the potential of VR as a powerful tool for cognitive research.

EduSolar: A Remote-Controlled Photovoltaic/Thermal Educational Lab with Integrated Daylight Simulation

This study presents a compact educational photovoltaic/thermal (PV/T) system designed for thorough performance assessment under simulated weather conditions. As an affordable educational tool, the system offers significant pedagogical value. The PV/T system features two photovoltaic modules: a thermally enhanced module and a standard one. The thermally enhanced module uses water as a coolant, which transfers heat from the PV cells to a fan-operated heat exchanger, with the coolant being recirculated to maintain optimal conditions. A halogen lamp, placed between the modules, simulates solar radiation to ensure effective electrical current generation. The system’s remote-control capabilities, managed via the Message Queuing Telemetry Transport (MQTT) protocol, enable real-time adjustments to the coolant flow rate, heat exchanger efficiency, and lamp brightness, as well as monitoring of electrical parameters. Experimental findings indicate that the PV/T module achieves a 7.71% increase in power output compared to the standard PV module and offers a 17.41% improvement in cooling efficiency over scenarios without cooling. Additionally, the numerical methods used in the study show a maximum deviation of 4.29% from the experimental results, which is considered acceptable. This study showcases a best practice model for solar training, applicable from elementary to university levels, and suggests innovative approaches to enhancing solar energy education.

Clouded judgments? The role of virtual weather in word valence evaluations

ABSTRACT Exploring the dynamic interface of environmental psychology and psycholinguistics, this investigation delves into how simulated weather conditions – sunny versus rainy – affect emotional perceptions of linguistic stimuli within a Virtual Reality (VR) framework. Participants assessed words’ emotional valence being exposed to these distinct environmental simulations. Contrary to expectations, we found that while rainy conditions modestly prolonged response times, they did not significantly alter the emotional valence attributed to words. Our study shows that weather can affect emotional cognition, but intrinsic emotional word properties are resilient to environmental influences. This highlights the complex interplay between environmental factors and linguistic processing and reaffirms the importance of environmental contexts in cognitive and emotional evaluations, especially in the face of climate change. By integrating VR technology with environmental psychology and linguistics, our research offers novel insights into the subtle yet significant ways in which virtual and real-world environments converge to shape human emotional and cognitive responses.

Oxygen-induced Ag-based binary structure for efficient heat-regulating windows

Heat-regulating (HR) windows are essential for net-zero-energy building approaches. Silver (Ag) thin films are preferred for developing high-functioning HR windows because of their unique optoelectrical properties. The quality of the HR windows depends on the tradeoff between the transparency and conductivity of the Ag film. Ultrathin Ag (thickness < 10 nm) obtained using the wetting technique has been universally adopted to overcome this trade-off. However, the use of a wetting layer can hinder the optimum transparency of HR windows because of the possible optical loss associated with the wetting layer. Herein, the partial oxidation technique was thoroughly investigated for fabricating one-step grown Ag used for high-functioning HR windows. The incorporation of oxygen (5.7 % volume) during Ag sputtering allowed the direct growth of continuous Ag film on substrates with a percolation threshold below 4 nm. Partial oxidization of Ag resulted in modulated optical coefficients of Ag, thereby facilitating the ease of developing AZO/Ag (6.5 nm)/glass with optimum transparency of 98 % and sheet resistance of 12 Ω sq−1. AZO/Ag/glass possessing a high Haacke figure of merit 68.1 (10−3 Ω−1) was developed for HR windows, with the capability of providing a temperature discrepancy of 2 °C for different simulated weather conditions.

Sphalerite oxidation simulating acidic, circumneutral and alkaline conditions to account for weathering behavior and Zn release

There is little evidence of sphalerite oxidation accounting for interfacial behavior, evolution of its oxidation capacity and kinetics processes under simulated weathering conditions. Accordingly, the present study combines surface analyses of pristine and leached low Fe-bearing and Pb-bearing sphalerite samples (PbS-ZnS) including X-ray Photoelectron Spectroscopy (XPS), Glow Discharge Optical Emission Spectroscopy (GDOES), Raman spectroscopy, Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM), along with the chemical evolution of leachates obtained after 24 h of mineral contact with 0.1 M NaOH, 0.1 M NaNO3, 0.1 M H2SO4 or 0.1 M HClO4 solution. An electrochemical study using Cyclic voltammetry (CV), Chronopotentiometry (CP), Chronoamperometry (CA), Linear sweep voltammetry (LSV) and Tafel plots (TP) of PbS-ZnS and marmatite-like sphalerite ((Fe, Zn)S) samples were also conducted to evaluate the oxidation capacity of the mineral interfaces in the solutions. Results reveal slow sphalerite oxidation linked to formation and heterogeneous polysulfides distribution, thus defining bare modifications of surface as indicated by SEM, AFM, GDOES, XPS and Raman studies. The highest oxidation was obtained in NaOH solution (NaOH > NaNO3 > HClO4 > H2SO4). While the corresponding Kf·CRb parameters were 1.07 × 10−7 and 3.14 × 10−8 mol·s−1 for PbS-ZnS and (Fe, Zn)S samples, respectively. A clear oxidation trend involving the progressive passivation of (Fe, Zn)S sample was revealed during evolution of sphalerite oxidation, whereas an alternative passive to transpassive oxidation was observed for the PbS-ZnS sample. We suggest weathering mechanisms for sphalerite, and their environmental implications are discussed.

Numerical method for solving coupled heat and mass transfer through walls for future integration into an urban climate model

Numerous studies of hygrothermal transfers through walls have highlighted the impacts of this phenomenon on energy consumption and indoor conditions. However, urban scale models that aim to simulate weather conditions and urban heat island effects within cities neglect moisture transfer through walls. The objective of this paper is to propose a method for solving this phenomenon that could be integrated into an urban climate model. This kind of integration requires the numerical schemes to be adapted as well as the spatiotemporal scales. The proposed method is based on an Implicit/Explicit discretisation scheme and a decoupled numerical approach for solving. Numerical stability is ensured by reducing the time step in critical moments, which are detected by five tests. This method is validated by comparison with a reference model (Delphin ®), on several study cases using different wall compositions and climates. A mesh sensitivity analysis is performed and shows that low permeability walls require a finer mesh than walls made of highly hygroscopic or capillary active materials. Furthermore, the more layers there are in the wall, the finer the mesh size needs to be. This numerical method allowed a balance to be found between computational cost and accuracy level in accordance with the expectations for an urban climate model. The future integration of this method into an urban climate model will make it possible to carry out energy/climate simulations, including the hygrothermal behaviour of walls, and thus to study its impact at urban scale.

Skid Resistance Performance of Asphalt Mixtures Containing Recycled Pavement Materials under Simulated Weather Conditions

One of the challenges of using recycled materials in road structures is to maintain safe and durable pavements. A multitude of research has been conducted over the years on various recycled materials, with a focus on the structural performance of pavements. Another crucial, but almost overlooked, aspect is the pavement’s ability to provide adequate skid resistance for road users under different climatic conditions. With this in mind, the present study aimed to investigate the skid resistance of asphalt mixtures containing two different types of recycled materials under laboratory-simulated weather conditions. Conventional hot-mix asphalt (HMA) and mixtures containing either reclaimed asphalt pavement (RAP) for aggregate replacement or crumb rubber (CR) as a bitumen additive were prepared and tested at different temperatures and different surface conditions (i.e., dry/wet) following a wetting protocol. Skid resistance was measured using a British Pendulum Tester (BPT). The results showed that the recycled mixtures performed similarly to conventional ones in terms of the skid resistance when the temperature was varied and under variable simulated surface conditions too. In some cases, they performed even better than conventional mixtures. Overall, a promising potential is demonstrated towards the use of the investigated recycled materials in asphalt surface courses.

Disaster Preparedness and Coping Among Older Adults: Empirical Analysis and Virtual Reality Platform Development

This symposium included 4 studies that use national and regional data to examine older adults’ disaster preparedness and coping. The first study examined age differences in preparedness for the continuation of COVID-19 with a sample of 443 residents in Dallas, TX. The findings highlight older adults’ resilience and special needs for different types of support during the pandemic. The second study examined the association of having COVID-19 and intergenerational relationships using the COVID-19 module of the Health and Retirement Study with a sample of 3266 respondents. Using a national sample of 1,467 respondents from the 2017 U.S. National Household Survey, the third study examined age differences relationships among the type of disasters (i.e., disasters with different lead-time), response efficacy, and disaster preparedness. The findings highlighted older adults’ unique vulnerability and resilience in different types of disasters. The fourth study discussed a pilot virtual reality platform under development to assist older adults to develop tailored household emergency preparedness plans and practice those plans with simulated extreme weather conditions and warnings for older adults to practice disaster response and develop relevant knowledge and skills as well as test and revise their emergency preparedness plans. Overall, this symposium emphasizes the uniqueness of older adults’ needs, vulnerability, and resilience to disasters.

Integrated BIM and VR to implement IPD mode in transportation infrastructure projects: System design and case application.

The complex design of transportation infrastructure hinders communication between different roles in the project, which makes it difficult to promote the Integrated Project Delivery (IPD) mode. This paper discusses a design simulation and communication system based on Building Information Modeling and Virtual Reality for transportation infrastructure (DSC-BV-TI system), integrated with BIM, with VR developed by using a game engine. Based on an analysis of the user’s demand, the system introduces a three-dimensional BIM model of traffic infrastructure in an immersive VR environment and realizes the simulation design, weather simulation, virtual driving, sight distance calculation, visual simulation and other functions of traffic infrastructure project by using the system’s safety assessment and scheme decision. The system is applied to the design of the Jinjiazhuang Extra-Long Tunnel project of the Yan-Chong Expressway in Hebei Province, which was built for the 2022 Winter Olympics. The results show that, using the DSC-BV-TI system, the designer has completed a display of the overall scheme: the user can use the steering wheel to drive a vehicle; use the head-mounted display to play the picture; realize the simulation and interaction in a variety of simulated weather conditions and environments; and use IPD mode to communicate and make decisions on the design scheme of the traffic infrastructure, tunnel speed limit and other aspects that play a key role. The DSC-BV-TI system has 8 advantages and 4 disadvantages identified through a questionnaire survey, the advantages including high fidelity, high efficiency and low cost. At the same time, according to the research results, three suggestions to help improve the system are discussed. DSC-BV-TI system as a communication bridge between the design team and other stakeholders reduces the communication gap and promotes the implementation of the IPD mode in transportation infrastructure projects.

Short-term and Long-term Drought Forecasts in Iraq Using Neural Networks and GIS

Drought is a dangerous phenomenon that affects the general life of the environment. Iraq is one of the countries that is facing drought periodically, especially in the last decades due to the great weather changes in the world including global warming, which resulted in less rainfall below normal levels. Therefore, it must be thought of drought forecasting because it is an important role in the planning and management of the water resources in Iraq. In this Study, Recurrent neural networks (RNN) were used as representing of Artificial Neural Networks (ANNs), which is a non-linear kind of ANNs where the output from it will feedback again as input for the next step. This type of neural network can simulate weather conditions with high precision such as rain, wind, earthquake, drought, and temperature. The model used to forecast droughts is the standardized precipitation index (SPI) series as a drought index in Iraq. The two-time scale which is used in this study, which is SPI 6 which represents short term drought and SPI 24 which represent long term drought. RNN was used to make forecasts for the SPI for the period 2020-2030. The assessment of the work and efficiency of RNN was regressing by (R), mean square error (MSE), and root mean square error (RMSE). Twenty-Four stations were selected to represent all study area (Iraq). Geographic information system (GIS) was used with the aid of Inverse distance weighted (IDW) to represent the forecasted drought for April month from years (2025 and 2030). The results showed that the study region (Iraq) suffered from varied drought levels in different periods ranging from mild to extreme drought, also the study showed improvement by decreasing the drought situation for period 2020-3030, which must be invested well.

Isotope ratio mass spectrometry and spectroscopic techniques for microplastics characterization

Micro- and nano-scale plastic particles in the environment result from their direct release and degradation of larger plastic debris. Relative to macro-sized plastics, these small particles are of special concern due to their potential impact on marine, freshwater, and terrestrial systems. While microplastic (MP) pollution has been widely studied in geographic regions globally, many questions remain about its origins. It is assumed that urban environments are the main contributors but systematic studies are lacking. The absence of standard methods to characterize and quantify MPs and smaller particles in environmental and biological matrices has hindered progress in understanding their geographic origins and sources, distribution, and impact. Hence, the development and standardization of methods is needed to establish the potential environmental and human health risks. In this study, we investigated stable carbon isotope ratio mass spectrometry (IRMS), attenuated total reflectance - Fourier transform infrared (ATR-FTIR) spectroscopy, and micro-Raman spectroscopy (μ-Raman) as complementary techniques for characterization of common plastics. Plastic items selected for comparative analysis included food packaging, containers, straws, and polymer pellets. The ability of IRMS to distinguish weathered samples was also investigated using the simulated weathering conditions of ultraviolet (UV) light and heat. Our IRMS results show a difference between the δ13C values for plant-derived and petroleum-based polymers. We also found differences between plastic items composed of the same polymer but from different countries, and between some recycled and nonrecycled plastics. Furthermore, increasing δ13C values were observed after exposure to UV light. The results of the three techniques, and their advantages and limitations, are discussed.

Efficacy of warming systems in mountain rescue: an experimental manikin study

Mountain accident casualties are often exposed to cold and windy weather. This may induce post-traumatic hypothermia which increases mortality. The aim of this study was to assess the ability of warming systems to compensate for the victim’s estimated heat loss in a simulated mountain rescue operation. We used thermal manikins and developed a thermodynamic model of a virtual patient. Manikins were placed on a mountain rescue stretcher and exposed to wind chill indices of 0 °C and − 20 °C in a climatic chamber. We calculated the heat balance for two simulated clinical scenarios with both a shivering and non-shivering victim and measured the heat gain from gel, electrical, and chemical warming systems for 3.5 h. The heat balance in the simulated shivering patient was positive. In the non-shivering patient, we found a negative heat balance for both simulated weather conditions (− 429.53 kJ at 0 °C and − 1469.78 kJ at − 20 °C). Each warming system delivered about 300 kJ. The efficacy of the gel and electrical systems was higher within the first hour than later (p < 0.001). We conclude that none of the tested warming systems is able to compensate for heat loss in a simulated model of a non-shivering patient whose physiological heat production is impaired during a prolonged mountain evacuation. Additional thermal insulation seems to be required in these settings.

Experimental and Theoretical Study of a Thermoelectric Dehumidification System

A laboratory-scale thermoelectric (TE) dehumidification system used to dehumidify air in a test chamber (volume of 1 m3) is described herein. The system consists of TE cooling modules, heat sinks, and a water cooling unit. Two rectangular-fin heat sinks were bonded with the hot and cold sides of the TE modules. The air from the test chamber circulated through the cold-side heat sink to remove moisture from the air in the test chamber. The water cooling unit was used to release heat from the hot side of the TE modules. A theoretical model was developed to simulate the air dehumidification process using the TE cooling system. Experiments were performed to validate the results of the developed model, indicating that the model showed good predictive ability. The TE dehumidification system reduced the humidity ratio by about 31.7% from the ambient value. The coefficient of performance of the system ranged from 0.44 to 0.94 under different operating electric currents supplied to the TE modules. The different electric current settings simulated weather conditions in Thailand. The main attraction of this approach is its compact, noiseless, reliable, and Freon-free operation.

Carrier-microencapsulation of arsenopyrite using Al-catecholate complex: nature of oxidation products, effects on anodic and cathodic reactions, and coating stability under simulated weathering conditions

Mining activities often generate large amounts of sulfide-rich wastes containing arsenopyrite (FeAsS), which when dissolved releases toxic arsenic (As) and generates acid mine drainage (AMD) that are both disastrous to the environment. To suppress arsenopyrite dissolution, a technique that selectively coats sulfide minerals with a protective layer of Al-oxyhydroxide called Al-based carrier-microencapsulation (CME) was developed. Although a previous study of the authors showed that Al-based CME could significantly limit arsenopyrite dissolution, nature of the coating formed on arsenopyrite, including its electrochemical properties, is still not well understood. Moreover, stability of the coating once exposed to weathering conditions remains unclear. Better understanding of these important issues would greatly improve Al-based CME especially in its application to real mine wastes. In this study, nature of the coating formed by Al-based CME was investigated using SEM-EDX, DRIFTS and XPS while the electrochemical properties of the coating were evaluated by cyclic voltammetry and chronoamperometry. Meanwhile, stability of the coating was elucidated using consecutive batch leaching experiments and weathering cell tests.SEM-EDX, DRIFTS and XPS results indicate that the protective coating formed on arsenopyrite by Al-based CME was mainly composed of bayerite (α-Al(OH)3), gibbsite (γ-Al(OH)3), and boehmite (γ-AlO(OH)). These Al-based coatings, which have insulating properties, made arsenopyrite less electrochemically active. The coatings also limited the extent of both the anodic and cathodic half-cell reactions of arsenopyrite oxidation that suppressed As release and acid generation. Weathering cell tests indicated that the oxidation of CME-treated arsenopyrite was effectively limited until about 15 days but after this, it started to gradually progress with time due to the increasing acidity of the system where Al-based coatings became unstable. Nonetheless, CME-treated arsenopyrite was less oxidized based on the released amounts of Fe, As and S suppressed by 80, 60 and 70%, respectively, compared with the one treated with control.

Abrasion Resistance of Gabion Wires Against Simulated Weathering and Field Conditions

Gabions are steel wire mesh cages filled with stones of appropriate size and mechanical characteristics. It is widely applied in geotechnical and hydraulic engineering as retaining and erosion control structures. Therefore, it must be made of durable materials to withstand most of the site conditions and weathering. Various coating technologies has been applied to enhance the lifespan. This study was conducted to examine the effect of moisture, acid, alkaline and saltwater under ultraviolet radiation and heat on the durability of a plastic-based coating material used as protective coating of gabion wires. Exposure conditions were simulated via natural weathering method, where they were placed outdoors at a designated test station. The samples were soaked and covered in soil to represent applications in waterlogged as well as buried / semi-buried field conditions. The weathered samples were subjected to the abrasion test after different periods of exposure over 250, 500 and 750 hours. 3 samples each were tested to maintain consistency in the measurements taken. Degradation of the coating material due to the simulated weathering conditions varied in terms of rate and severity, though the overall results indicate alkalinity to be more detrimental than acidity and salinity. Variation among the samples’ degradation was observed to be more distinct in the terms of soaked and soil-covered conditions. In conclusion, samples buried in alkali-tainted soil are the least durable against abrasion as the recorded mass loss percentage was the highest, followed by acid-soaked samples. Some plausible explanations include the lack of heat built up on seawater-soaked samples leading to less degradation, and surfacial biofouling of soaked samples serving as a protection against UV light or chemical attack. Further work is in the pipeline to examine the effects of longer exposure period and wider range of exposure conditions to verify the coating material’s long-term performance.

Assessing the potential effect of extreme weather on water quality and disinfection by-product formation using laboratory simulation

Increased frequency and severity of extreme weather events (i.e., floods and droughts) combined with higher temperatures can threaten surface water quality and downstream drinking water production. This study characterized the effects of extreme weather events on dissolved organic matter (DOM) washout from watershed soils and the corresponding contribution to disinfection by-product (DBP) precursors under simulated weather conditions. A laboratory simulation was performed to assess the effects of temperature, drought, rainfall intensity, sea level rise, and acid deposition on the amount of DOM released from soil samples. DBP formation potentials (DBPFPs) were obtained to assess the effect of extreme weather events on DBP formation and drinking water quality. The results demonstrated that the dissolved organic carbon (DOC) and carbonaceous DBP levels increased with increasing temperature in a dry (drought) scenario. Regardless of the watershed from which a soil sample was obtained and the incubation temperature during rewetting or chlorination processes, the DOC and carbonaceous DBP levels also increased with increasing temperature. Brominated DBP formation was increased when bromide was present during the rewetting of soil, indicating the effect of sea level rise. When bromide was present during the chlorination of water for DBPFP tests, only the level of brominated DBPs increased. Acid deposition had various effects under different weather conditions. The results of heavy rainfall simulations suggested that water quality deteriorates at the beginning of an extreme rainfall event. Abundant DOM was washed out of soil, leading to a peak in the DBPFP level. The level of DOM in seepage water was less than that of the surface runoff water during rainfall. The situation was more severe when the rainfall came after a long drought and the drought–rewetting cycle effect occurred.

Morphological Transformation of Silver Nanoparticles from Commercial Products: Modeling from Product Incorporation, Weathering through Use Scenarios, and Leaching into Wastewater.

There is increasing interest in the environmental fate and effects of engineered nanomaterials due to their ubiquitous use in consumer products. In particular, given the mounting evidence that dramatic transformations can occur to a nanomaterial throughout its product lifecycle, the appropriateness of using pristine nanomaterials in environmental testing is being questioned. Using a combination of transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-mass spectrometry (ICP-MS), this work examines the morphological and compositional effects of conditions mimicking a typical lifecycle of a nano-enabled product, from the production of the silver nanoparticle (AgNP)-laden textiles, through its use, laundering, and then finally, its leaching and incubation in the wastewater collection system. These simulated weathering conditions showed evidence for the transformation of AgNPs into AgCl and Ag2S. Incubation in raw wastewater had the most dramatic effect on the AgNPs in terms of transformation, no matter what initial weathering was applied to the NPs prior to incubation. However, despite extensive transformation noted, AgNPs were still present within all the samples after the use scenarios.

Meteorological conditions leading to extreme low variable renewable energy production and extreme high energy shortfall

To mitigate climate change a renewable energy transition is needed. Existing power systems will need to be redesigned to balance variable renewable energy production with variable energy demand. We investigate the meteorological sensitivity of a highly-renewable European energy system using large ensemble simulations from two global climate models. Based on 3×2000 years of simulated weather conditions, daily wind and solar energy yields, and energy demand are calculated. From this data, 1-, 7- and 14-days events of extreme low renewable energy production and extreme high energy shortfall are selected. Energy shortfall is defined as the residual load, i.e. demand minus renewable production. 1-day low energy production days are characterised by large-scale high pressure systems over central Europe, with lower than normal wind speeds. These events typically occur in winter when solar energy is limited due to short day lengths. Situations of atmospheric blocking lead to long lasting periods of low energy production, such 7- and 14-days low production events peak late summer. High energy shortfall events occur due to comparable high pressure systems though now combined with below normal temperatures, driving up energy demand. In contrast to the low energy production events, 1-, 7- and 14-days high shortfall events all occur mid-winter, locked to the coldest months of the year. A spatial redistribution of wind turbines and solar panels cannot prevent these high-impact events, options to import renewable energy from remote locations during these events are limited. Projected changes due to climate change are substantially smaller than interannual variability. Future power systems with large penetration of variable renewable energy must be designed with these events in mind.

Carrier-microencapsulation using Al-catecholate complex to suppress arsenopyrite oxidation: Evaluation of the coating stability under simulated weathering conditions

Arsenopyrite (FeAsS) is the most common primary arsenic-sulfide mineral in nature, and its oxidation causes the release of toxic arsenic (As). To mitigate these problems, carrier-microencapsulation (CME), a technique that passivates sulfide minerals by covering their surfaces with a protective coating, has been developed. In the previous study of authors on CME, Al-catecholate complex significantly suppressed arsenopyrite oxidation via electron donating effects of the complex and the formation of an Al-oxyhydroxide coating. For the application of this technique to real tailings, however, further study should be carried out to elucidate long-term effectiveness of the coating to suppress arsenopyrite oxidation. This study investigates the stability of the coating formed on arsenopyrite by Al-based CME using weathering tests. The Al-oxyhydroxide coating suppressed arsenopyrite oxidation until about 50 days of the experiment, but after this, the amounts of oxidation products like dissolved S and As increased due to the gradual dissolution of the coating with time as a result of the low pH of leachate. This suggests that co-disposal of Al-based CME-treated arsenopyrite with minerals that have appropriate neutralization potentials, so that the pH is maintained at around 5 to 8 where Al-oxyhydroxide is stable.

Recoupling fire and grazing reduces wildland fuel loads on rangelands

AbstractFire suppression and exclusion, the historically dominant paradigm of fire management, has resulted in major modifications of fire‐dependent ecosystems worldwide. These changes are partially credited with a recent increase in wildfire number and extent, as well as more extreme fire behavior. Fire and herbivory historically interacted, and research has shown that the interaction creates a unique mosaic of vegetation heterogeneity that each disturbance alone does not create. Because fire and grazing have largely been decoupled in modern times, the degree to which the interaction affects fuels and fire regimes has not yet been quantified. We evaluated effects of fire‐only and pyric herbivory on rangeland fuels and fire behavior simulated using BehavePlus at four sites across the southern Great Plains. We predicted patches managed via pyric herbivory would maintain lower fuel loads, and less intense simulated fire behavior than fire alone. We found that time since fire was a significant predictor of fuel loads and simulated fire behavior characteristics at all sites. Fuel loads and simulated fire behavior characteristics (flame length and rate of spread) increased with increasing time since fire in all simulated weather scenarios. Pyric herbivory mediated fuel accumulation at all sites. Mean fuel loads in fire‐only treatments exceeded 5000 kg/ha within 24 months, but pyric herbivory treatments remained below 5000 kg/ha for approximately 36 months. Simulated flame lengths in fire‐only treatments were consistently higher (up to 3 × ) than in pyric herbivory treatments. Similarly, fire spread rates were higher in fire‐only than in pyric herbivory treatments in all simulated weather conditions. Although all sites had potential to burn in the most extreme weather conditions, pyric herbivory reduced fuel accumulations, flame lengths, and rates of spread across all weather patterns simulated. These reductions extended the amount of time standard wildland firefighting techniques remain effective. Therefore, incorporating pyric herbivory into fuel management practices, in areas of high herbaceous productivity, increases the effectiveness of fuel treatments.