Water Accumulation Research Articles

Safeguarding public facilities: a study on enhancing safety in mosque amenities through slip-resistance and surface innovations

PurposeThis study critically examines the safety aspects of ablution spaces in United Arab Emirates (UAE) mosques, emphasising the evaluation of smooth ceramic tile floorings prone to water accumulation. As an integral practice in Islamic worship, ablution spaces cater to a diverse demographic, making their safety a paramount concern. This study aims to meticulously assess slip-resistance properties and surface characteristics to provide practical recommendations for enhanced safety measures.Design/methodology/approachThe investigation involves in situ measurements of traction properties and an extensive analysis of surface features in thirty mosques across the UAE. This comprehensive approach allows for identifying the unique challenges posed by ceramic tile floorings in ablution spaces. The study uses a portable tribometer for dynamic friction coefficient measurements, ensuring accurate slip-resistance evaluations. Surface texture analysis uses a portable profilometer to quantify roughness parameters.FindingsThe study’s findings significantly advance the comprehension of safety considerations in ablution spaces. Through empirical evidence and evidence-based insights, the research identifies immediate safety concerns and provides practical recommendations to create secure and inclusive environments within mosques. The emphasis lies on safeguarding the well-being of worshippers and contributing to the broader goal of safety in religious spaces.Originality/valueThe original contribution of this study lies in its dual focus on immediate safety concerns and the deeper understanding of unique safety challenges within ablution spaces. By offering evidence-based insights and practical recommendations, the research strives to make meaningful contributions to creating secure and inclusive environments within mosques.

Solar-Driven Drum-Type Atmospheric Water Harvester Based on Bio-Based Gels with Fast Adsorption/Desorption Kinetics.

Sorption-based atmospheric water harvesting is an attractive technology for exploiting unconventional water sources. A critical challenge is how to facilitate fast and continuous collection of potable water from air. Here, a bio-based gel (CAL gel), resulting from the integration of a whole biomass-derived polymer network with lithium chloride is reported. A fast adsorption/desorption kinetics, with a water capture rate of 1.74kg kg-1 h-1 at 30% relative humidity and a desorption rate of 1.98kg kg-1 h-1, was simultaneously realized in one piece of CAL gel, because of its strong hygroscopicity, hydrophilic network, abundant water transport channels, photothermal conversion ability, and ∼200-μm-thick self-supporting bulky structure caused by multicomponent synergy. A solar-driven, drum-type, tunable, and portable harvester is designed that can harvest atmospheric water within a brief time. Under outdoor conditions, the harvester with CAL gels operates 36 switches (180°) per day realizes a water yield of 8.96kg kggel -1 (18.87g kgdevice -1). This portable harvester highlights the potential for fast and scalable atmospheric water harvesting in extreme environments. This article is protected by copyright. All rights reserved.

Association Between Demographic Characteristics of Users’ and Overall Satisfaction with Water Supply Service

Water constitutes an indispensable resource for various aspects of daily life, encompassing essential needs such as drinking, cooking, sanitation, and irrigation. Beyond household applications, diverse livelihood activities, including livestock management, gardening, crop cultivation, food processing, aquaculture, and fisheries, also rely on water. The assessment of customer satisfaction holds paramount significance in driving performance enhancements for service providers, even within government-owned entities offering critical services like water supply. This research aims to scrutinize the interplay between overall satisfaction with water services and its determinants, including satisfaction with water quality, and various parameters such as water supply hours, tap pressure, supplied water quantity, management responsiveness and communication, and water tariff. Anticipatedly, water supply hours, quantity, and quality are expected to exert a crucial influence on user satisfaction. Although users express a satisfaction level above neutral, it falls short of reaching a fully satisfactory level. Key contributors to user satisfaction involve aspects such as water supply hours, pressure, quantity, and quality, while complaints about water supply yield slightly lower satisfaction. Satisfaction with water service hours, quantity, and quality emerges as a driving force for overall satisfaction. The analysis reveals no significant association between overall satisfaction and demographic variables such as occupation, gender, age, education, and the main income source. However, a noteworthy association exists between satisfaction with water pressure and the water collection method, and a robust link is observed between satisfaction with water quality and respondents' water treatment practices. The provision for complaints is significantly associated with satisfaction regarding management responsiveness and communication. Multiple regression analysis underscores a positive relationship between overall satisfaction with water services and satisfaction with water quality and supply hours, indicating that higher satisfaction with these factors enhances overall satisfaction with water services.

Water-Filling Characteristics and Water Source of Weakly Rich Water and Weakly Conducting Water Aquifers in the Changxing Formation after Mining Damage

The escalation of mining activities in the karst regions of Guizhou Province has heightened the occurrence of water-inrush incidents in deep coal mines. This study focused on water-inrush phenomena within the Xinhua mining area of Jinsha County, Guizhou Province, aiming to investigate the sources of these incidents. The findings indicated that the overlying limestone of the Changxing Formation in the coal seam served as a vulnerable aquifer under certain conditions, leading to water inrushes. The analysis of the spatiotemporal distribution patterns of water-inrush incidents at the working face indicated that previous mining operations damaged the shallow Changxing Formation limestone, resulting in the accumulation of goaf water and the formation of numerous mining-induced fractures. These fractures served as rapid conduits for water inrushes from both atmospheric precipitation and underground sources at the deep working face. The examination of surface water and mine water quality demonstrated that both exhibited similar characteristics, predominantly featuring bicarbonate, sulfate, and sodium compositions. Investigation into the relationship between mine water inflow and atmospheric precipitation established that atmospheric precipitation influenced the mine water supply cycle, with a replenishment period of ~10 months during the operational phase of the Jinyuan Coal Mine and about one month post-closure. The fractures induced by mining activities within the Changxing Formation limestone facilitated water flow, with atmospheric precipitation serving as the primary water source for the mine. This study offered a valuable scientific foundation for addressing water-related damage resulting from atmospheric precipitation in mines susceptible to water inrushes under analogous hydrogeological conditions.

Factors associated with mosquito control among construction workers: A systematic review.

Workers in the construction industry frequently work in construction sites with numerous areas that can potentially accumulate water, such as tanks, wet cement surfaces, or water puddles. These water collection sites become ideal breeding grounds for mosquito infestation, which leads to a higher prevalence of mosquito-borne diseases, especially malaria and dengue among construction workers. Despite that numerous factors have been identified in controlling vector-borne diseases, the specific factors that influence mosquito control at construction sites have yet to be explored. This systematic review aims to determine the factors associated with mosquito control among construction workers. Primarily, articles related to factors associated with mosquito control among construction workers were collected from two different online databases (ScienceDirect and EBSCOhost). Two independent reviewers were assigned to screen the titles and abstracts of the collected data, stored in Microsoft Excel, against the inclusion and exclusion criteria. Afterwards, the quality of the included articles was critically assessed using the Mixed Method Appraisal Tool (MMAT). Of the 171 articles identified, 4 were included in the final review. Based on the thorough evaluation, mosquito-related knowledge, practical mosquito prevention measures, and Larval Source Management (LSM) were identified as vital factors associated with mosquito control among construction workers. The significant association between mosquito-related knowledge and control practices indicates higher knowledge linked to effective practices, particularly among female workers and those who were recently infected with malaria. Concurrently, there were notable challenges regarding sustainable preventive measures and larval control methods in construction settings. Implementing effective mosquito control, including knowledge and practice on mosquito control together with vector control, is highly required to suppress the expanding mosquito population. It is recommended that employers provide continuous mosquito control education and training to their employees and reward them with incentives, while employees should comply with the guidelines set by their employers to ensure successful mosquito control and reduce the spread of mosquito-borne diseases in the construction industry.

Preparation and properties of a metal-organic frameworks polymer material based on Sa-son seed gum capable of simultaneously absorbing liquid water and water vapor

Atmospheric water harvesting (AWH) technology has attracted significant attention as an effective strategy to tackle the global shortage of freshwater resources. Work has focused on the use of hydrogel-based composite adsorbents in water harvesting and water conservation. The approaches adopted to make use of hygroscopic inorganic salts which subject to a “salting out” effect. In this study, we report the first use of modified UIO-66-NH2 as a functional steric cross-linker and Sa-son seed gum was used as polymeric substrate to construct super hygroscopic hydrogels by free radical copolymerization. The maximum water uptake on SMAGs (572 cm3·g−1) outperforms pure UIO-66-NH2 (317 cm3·g−1). Simultaneously, our first attempt to use it for anti-evaporation applications in an arid environment (Lanzhou, China) simulating sandy areas. The evaporation rate of the anti-evaporation material treated with 0.20 % super moisture-absorbent gels (SMAGs) decreased by 6.1 % over 64 h period under natural condition in Lanzhou, China. The prepared material can not only absorb liquid water but also water vapor, which can provide a new way for water collection and conservation technology. The design strategy of this material has wide applications ranging from atmospheric water harvesting materials to anti-evaporation technology.

Implications of Heavy Metal Accumulation in Fish Feed, Water, Sediment, and Different Fish Species in a Polyculture System.

Heavy metal bioaccumulation in organisms is primarily a result of dietary uptake. The current study examines the concentrations of heavy metals (Pb, Cd, Cr, and Cu) in fish feed, water, sediment, and three fish species (Catla catla, Labeo rohita, and Cyprinus carpio) from different feeding zones in a polyculture pond system. Furthermore, associated human health risks were also evaluated. The fish samples (n = 25 for each species) were collected from 10 different fish ponds in the Kohat district, Pakistan. Heavy metals were determined using an atomic absorption spectrometer. Results revealed higher concentrations of heavy metals in sediment, followed by water. However, the concentration of heavy metals in fish feed was lower than the standard limits. In the case of fish, the bottom feeder (C. carpio) notably exhibited higher (P < 0.05) levels of heavy metals than the column feeder (L. rohita) and surface feeder (C. catla) fish. Moreover, in the liver of all fish species, the bioaccumulation of heavy metals was higher, followed by the gills. Principal component analysis (PCA) demonstrated a strong correlation of heavy metals in C. carpio gills, flesh, feed, and pond water, while the heavy metals in the liver correlated with the detected metals in sediment. The human health risk analysis shows that bottom feeder fish had higher estimated daily intake (EDI), target hazard quotient (THQ), and hazard index (HI) values (> 1). Consequently, the exposed population may experience adverse health effects. The findings of this study suggest that the bottom feeder (C. carpio) bioaccumulates a higher concentration of heavy metals than column (L. rohita) and surface feeder (C. catla) in the polyculture system.

In vitro toxicity evaluation in A549 cells of diesel particulate matter from two different particle sampling systems and several resuspension media.

In urban areas, inhalation of fine particles from combustion sources such as diesel engines causes adverse health effects. For toxicity testing, a substantial amount of particulate matter (PM) is needed. Conventional sampling involves collection of PM onto substrates by filtration or inertial impaction. A major drawback to those methodologies is that the extraction process can modify the collected particles and alter their chemical composition. Moreover, prior to toxicity testing, PM samples need to be resuspended, which can alter the PM sample even further. Lastly, the choice of the resuspension medium may also impact the detected toxicological responses. In this study, we compared the toxicity profile of PM obtained from two alternative sampling systems, using in vitro toxicity assays. One system makes use of condensational growth before collection in water in an impinger - BioSampler (CG-BioSampler), and the other, a Dekati® Gravimetric Impactor (DGI), is based on inertial impaction. In addition, various methods for resuspension of DGI collected PM were compared. Tested endpoints included cytotoxicity, formation of cellular reactive oxygen species, and genotoxicity. The alternative collection and suspension methods affected different toxicological endpoints. The water/dimethyl sulfoxide mixture and cell culture medium resuspended particles, along with the CG-BioSampler sample, produced the strongest responses. The water resuspended sample from the DGI appeared least toxic. CG-BioSampler collected PM caused a clear increased response in apoptotic cell death. We conclude that the CG-BioSampler PM sampler is a promising alternative to inertial impaction sampling.

Numerical investigation and experimental verification of liquid water dynamic transfer characteristics in the flow field of PEMFC with dead-ended anode during gas purging

Water accumulation in the anode during the operation of a proton exchange membrane fuel cell with the dead-ended anode (DEA) has a significant impact on its performance. In this study, numerical simulation and experimental verification were combined to investigate the water accumulation and water dynamic transfer characteristics in the anode flow field during dead-ended operation and gas purging, respectively. The effects of placement orientation, surface wettability, and purge time on the water dynamic transfer characteristics are investigated. The results show that the placement orientation has significant effects on the water distribution characteristics and drainage for PEMFC. When placed vertically and with a purging time of 50 ms, the liquid water saturation in the channel is 5.52 %, which drains 14.91 % more water than that of horizontal placement. Besides, Water discharge velocity and water removal ratio should be considered comprehensively in the development of the purge strategy, the optimal purging time is 70 ms with the water discharge velocity and water removal rate are 0.39 μl/ms and 97.34 %, respectively. Finally, the transfer process of liquid water in the flow field with DEA mode is observed by visual experiment, and the results of the numerical simulation are verified.

RGOs-AgNPs/PVA composite sponges for efficient solar saltwater evaporation

With an increasing demand for seawater desalination, fabricating photothermal materials with low cost, high photothermal conversion efficiency, and excellent mechanical stability is necessary but remains challenging. In this work, reduced graphene oxide nanosheets (RGOs) and silver nanoparticles (AgNPs) doped polyvinyl alcohol (PVA) sponges (RGOs-AgNPs/PVA) are fabricated by the mechanical foaming and impregnation reduction method, which combine the flexible porous structure of PVA sponges with the photothermal properties of RGOs-AgNPs. The incorporation of RGOs-AgNPs enhances the surficial hydrophobicity and reduces the accumulation of water on the surface, and the photothermal synergistic effect of RGOs-AgNPs enhances the water evaporation rate. The results showed that the evaporation rate of RGOs-AgNPs/PVA was 2.09 kg m−2 h−1 and the photothermal conversion efficiency was 94.2 % under standard sunlight intensity of 1 sun (1.0 kW m−2). Furthermore, the long-term stability and effective desalination capability of the RGOs-AgNPs/PVA solar evaporation device offer a potential opportunity for massive seawater desalination. Therefore, this work shows the prospect of combining flexible porous sponges with photothermal materials for practical solar evaporation.

Detection of DENV-1, DENV-3, and DENV-4 Serotypes in Aedes aegypti and Aedes albopictus, and Epidemic Risk in the Departments of Oueme and Plateau, South-Eastern Benin.

Background: This study conducted in the departments of Oueme and Plateau aims to assess the presence of the dengue virus and its different serotypes in Aedes aegypti and Aedes albopictus, as well as the epidemic risk incurred by the populations. Methods: Collections of adult mosquitoes using human landing catches (HLC) were carried out in six communes, three (Porto-Novo, Adjarra, and Avrankou) in the Oueme department and the rest (Ifangni, Kétou, and Pobè) in the Plateau department. Pools of ten Aedes mosquitoes were formed, and stored at -80°C in RNA later. RT-PCR was used to detect dengue virus, and conventional PCR for the different serotypes. Inspection of water containers and collection of Aedes larvae was performed inside and around each house to calculate the stegomyan indices. Results: In the six communes, the dengue virus was present both in Ae. aegypti and Ae. albopictus. Combined data of the two Aedes species at the communes level revealed infection rates ranging from 80.00% (95% CI: 61.43-92.29) to 96.67% (95% CI: 82.78-99.92). In all the communes, the values of stegomyan indices reached the WHO threshold, which indicates the existence of the risk of an arbovirus epidemic. In addition, the infection rates were similar for Ae. aegypti [88.19% (95% CI: 81.27-93.24)] and Ae. albopictus [86.79% (95% CI: 74.66-94.52)]. The three virus serotypes detected in the pools of Aedes were DENV-1, DENV-3, and DENV-4, with a high prevalence for the first two. Conclusion: This study revealed that three serotypes (DENV-1, DENV-3, and DENV-4) of dengue virus circulate in Ae. aegypti and Ae. albopictus in the departments of Oueme and Plateau. Moreover, the risk of transmission of arboviruses was globally high and variable from commune to commune. This information is essential for informed decision-making in the preventive control of the disease.

Susceptibility to Flooding and Urban Flooding in Small Municipalities: Hydrogeomorphological, Land Use and Land Cover Aspects in a Multi-Criterion Analysis

Objective: To investigate areas susceptible to flooding and inundation, testing the hypothesis that the accumulation of surface water does not depend exclusively on fluvial flood pulses.   Theoretical Framework: Anthropogenic actions have played a significant role in modifying natural physiography, especially through urbanization and occupation of environmentally sensitive areas. These interventions have a direct impact on the dynamics of natural processes, highlighting the need to understand local hydrogeomorphology in order to ensure efficient territorial planning.   Methodology: The research comprised a multi-criteria analysis involving hydrological, geomorphological, land use and occupation data associated with precipitation data for a small municipality. This municipality has urban development in the area of influence of a main river in its catchment area.   Results and Discussion: Around 52% of the municipality is urbanized with 95% on slopes ranging from 0 to 23º, upstream of a cumulative flow of 18,000. Rainfall is 1366 mm/year and tends to decrease, although there has been a 62% increase in flooding in recent years. Around 75% of the urbanized area is vulnerable to pluvial flooding, while the rest is subject to both pluvial flooding and fluvial flood pulses.    Research Implications: Insights into how the results can influence urban planning practices, extending to the fields of hydrogeomorphology and land use and occupation management.   Originality/Value: The methodology is simple and accessible to small municipalities and urban planning entrepreneurs. Its relevance is evidenced by the fact that it improves urban planning, minimizing socio-economic and environmental costs.

Performance Assessment of Novel Transparent Insulation Materials for Integrated Storage Collectors

Transparent insulation structures play a pivotal role in harnessing solar energy efficiently, akin to the greenhouse effect in the atmosphere. This study undertakes a systematic evaluation of a novel sorbitol- or bio-based polycarbonate (bio-PC) for thermal insulation (TI) structures and hot water collector systems. Employing optical and mechanical methods, the bio-PC was comprehensively characterized on the polymer film level. Subsequently, the technical and ecological performance of these structures in various hot water collectors and systems was rigorously modelled and simulated. Results indicated that the novel bio-PC exhibited superior properties compared to conventional materials like cellulose acetate or fossil-based PC, showcasing promising prospects for widespread adoption. Drawing parallels to the greenhouse effect of CO2, the functional principle of transparent insulation structures is rooted in high solar transmittance and infrared absorbance, primarily governed by carbon-oxygen bonds. While fossil-fuel based transparent insulation materials have been prevalent, they suffer from drawbacks such as average infrared absorbance and susceptibility to yellowing. In contrast, the newly introduced bottom-up biopolymer bio-PC, derived from sorbitol derivatives, offers a compelling alternative. The study sheds light on the potentials and limitations of bio-PC for transparent insulation structures in integrated storage or flat plate collectors, aiming to mitigate environmental impacts associated with traditional materials. Future research directions emphasize refining modelling tools and addressing input data deficiencies, particularly for life cycle analysis. Concurrently, efforts are directed towards enhancing simulation accuracy and reliability through concurrent measurements of collector systems equipped with bio-PC-based transparent insulation. This research underscores the critical role of innovative materials in advancing sustainable energy solutions, with bio-PC emerging as a promising candidate in the realm of transparent insulation technology.

GIS-based methodology for culvert location evaluation on railways: a case study of the Qena–Safaga Track in Egypt

Abstract Railway infrastructure plays a critical role in transportation networks, and ensuring its integrity and resilience is of utmost importance. Culverts are vital components of railway tracks, providing drainage and water management to prevent structural damage and disruptions. Identifying suitable locations for culverts requires careful evaluation and consideration of various factors. A study using GIS techniques was conducted on an existing commercial railway track in the Eastern Desert of Upper Egypt to assess the effectiveness of existing culverts in preventing flash floods. The culvert suitability index map revealed that areas with high slopes and large drainage areas were more susceptible to water accumulation, indicating the need for culverts. The study also highlighted areas where culverts could be installed without significantly impacting existing infrastructure. It was recommended to install culverts in 27 locations along the track where they intersect with watercourses. Existing culverts covered just 93 watercourses, while 5 specialized culverts needed to be relocated. The findings have significant implications for railway engineering, as using GIS techniques streamlines the process of culvert location evaluation, saving time and resources. The systematic approach ensures culverts are installed in the most appropriate locations, minimizing flooding risks and ensuring the safety and efficiency of railway operations.

Effect of SARS-CoV-2 S protein on the proteolytic cleavage of the epithelial Na+ channel ENaC.

Severe cases of COVID-19 are characterized by development of acute respiratory distress syndrome (ARDS). Water accumulation in the lungs is thought to occur as consequence of an exaggerated inflammatory response. A possible mechanism could involve decreased activity of the epithelial Na+ channel, ENaC, expressed in type II pneumocytes. Reduced transepithelial Na+ reabsorption could contribute to lung edema due to reduced alveolar fluid clearance. This hypothesis is based on the observation of the presence of a novel furin cleavage site in the S protein of SARS-CoV-2 that is identical to the furin cleavage site present in the alpha subunit of ENaC. Proteolytic processing of αENaC by furin-like proteases is essential for channel activity. Thus, competition between S protein and αENaC for furin-mediated cleavage in SARS-CoV-2-infected cells may negatively affect channel activity. Here we present experimental evidence showing that coexpression of the S protein with ENaC in a cellular model reduces channel activity. In addition, we show that bidirectional competition for cleavage by furin-like proteases occurs between 〈ENaC and S protein. In transgenic mice sensitive to lethal SARS-CoV-2, however, a significant decrease in gamma ENaC expression was not observed by immunostaining of lungs infected as shown by SARS-CoV2 nucleoprotein staining.

Different wettability surfaces composited by polydopamine-based SiO2/TiO2 coatings for efficient water collection and anti-corrosion application

Designing hybrid surfaces with superhydrophilic and superhydrophobic properties represents a promising approach for fog collection. Inspired by the adhesive properties of mussel proteins, a polydopamine (PDA) film was firmly attached to a brass surface through a combination of chemical etching and spontaneous dopamine polymerization. By harnessing the exceptional characteristics of PDA as a "double-sided adhesive," a hybrid surface with mixed wettability was created using a facile and cost-effective method involving SiO2 and TiO2 nanoparticles (NPs). The TiO2 NPs served as the hydrophilic sites for water capture, while the SiO2 NPs acted as the hydrophobic region to induce water droplet rolling. The resulting hybrid surface exhibited a significant improvement in water collection rate, measuring approximately 1.182 g/cm2/h, which was 1.84 times higher than that of the bare brass surface. This demonstrated a remarkable enhancement in fog collection capacity. Moreover, the hybrid surface demonstrated commendable corrosion resistance and remarkable durability, indicating its great potential for widespread application in practical scenarios.

Should We Value Rain Harvesting More in Turkey for Mitigating Precipitation Extremes

Mitigating precipitation extremes is a major issue due to destructive global warming and climate change. Heavy rainfall and drought have posed a threat to human life and ecology. That said, new strategies and new action plans are needed at local and global levels through needed cooperation from different stakeholders to handle the possible risks associated with precipitation extremes. Türkiye has become one of the most vulnerable countries involved in climate change due to its geographical location, rapid urbanization, and deforestation. Many forests have been destroyed to make room for agriculture and animal grazing as well as for manufacturing and construction. The impact has caused complications in landscapes. Precipitation extremes, such as heavy rainfalls and drought, are posing a big threat for many cities in Türkiye. In this line, the present study aims to explore potential benefits of rain harvesting in mitigating precipitation extremes by overviewing regulatory and legislative actions of rainwater harvesting worldwide and an interview based survey. The results of the study showed that Türkiye has several problems with infrastructure to mitigate precipitation extremes, such as shortcomings in capacity and old water management systems, unseparated water collection and sewage systems and lack of green infrastructure. In addition to urbanization, expansion in industry and tourism may cause water availability. RWH promises several benefits thanks to its cost effectiveness and contribution to water storage. The study also showed many authorities around globe try to boost RWH use by either stipulating RWH or encouraging through incentives and save a large amount of water with different projects.

Study on current-carrying tribological characteristics of C-Cu sliding electric contacts under water accumulation from rainfall condition

Pantograph-OCS system sliding electrical contact is the only way for train energy transmission, which determines the safety and stability of energy transfer. And the current-carrying wear is the core factor that affecting the service performance of C-Cu contact pairs. C-Cu mate pairs often work for a long time in rainy/humid environments due to its exposed nature of work, and the contact interface often accumulates a large amount of water. Existing operating experience has shown that the carbon sliding plate of the pantograph experiences abnormal wear and frequent failure during rainfall, resulting in a significant decrease in service performance and lifespan. This article found that the thickness of the water film at the contact interface has a significant impact on the current carrying friction and wear performance of C-Cu contact pairs. When the thickness of the water film exceeds a certain range, the carbon skateboard will cause abnormal wear under high current, with the wear amount being more than three times the minimum value. The contact resistance also increases by 53.9%, which is related to the obstruction of current transmission. It also proves that the water film lubrication effect can be restored during the process of rainfall decreasing from large to small. The research can help to provide a suitable maintenance policy for pantograph and catenary system during the rainy season.

Machine learning for water demand forecasting: case study in a Brazilian coastal city

Abstract Water resources management is crucial for human well-being and contemporary socio-economic development. However, the increasing use of water has led to various problems that affect its quality and availability. To address these issues, accurate forecasting of water consumption is essential for the optimal operation of water collection, treatment, and distribution systems. This study aims to compare four machine learning methods for predicting daily urban water demand in a Brazilian coastal tourist city (Guaratuba – Paraná). Historical data from the city’s water distribution system, spanning from 2016 to 2019 (1,461 measurements in total), were considered along with meteorological and calendar data to conduct the investigation. Three time series cross-validation approaches were considered for each method, thus totaling 12 evaluation settings. All models were subjected to hyperparameter optimization and evaluated using appropriate performance metrics from the literature. Results demonstrate the importance of using nonlinear models to predict short-term water demand, highlighting the problem’s complexity. From the compared models, multilayer perceptron provided the best results. Finally, regardless of the model, the best results were obtained by applying an expanding window time series cross-validation, indicating that the more historical data available, the better, in this particular case.

Space-confined manganese oxides nanosheets for efficient catalytic decomposition of ozone

Ground-level ozone has long posed a substantial menace to human well-being and the ecological milieu. The widely reported manganese-based catalysts for ozone decomposition still facing the persisting issues encompass inefficiency and instability. To surmount these challenges, we developed a mesoporous silica thin films with perpendicular nanochannels (SBA(⊥)) confined Mn3O4 catalyst (Mn3O4@SBA(⊥)). Under a weight hourly space velocity (WHSV) of 500,000 mL g−1 h−1, the Mn3O4@SBA(⊥) catalyst exhibited 100% ozone decomposition efficiency in 5 h and stability across a wide humidity range, which exceed the performance of bulk Mn3O4 and Mn3O4 confine in commonly reported SBA-15. Rapidly decompose 20 ppm O3 to a safety level below 100 μg m−3 in the presence of dust in smog chamber (60 × 60 × 60 cm) was also realized. This prominent catalytic performance can be attributed to the unique confined structure engenders the highly exposed active sites, facilitate the reactant-active sites contact and impeded the water accumulation on the active sites. This work offers new insights into the design of confined structure catalysts for air purification.