Search Results (164)

In regions lacking sufficient data, remote sensing (RS) offers a reliable alternative for precipitation estimation, enabling more effective drought management. This study comprehensively evaluates four commonly used RS datasets—Climate Hazards Center InfraRed Precipitation with Station data (CHIRPS), Tropical Applications of Meteorology using Satellite data (TAMSAT), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks–Climate Data Record (PERSIANN-CDR), and Multi-Source Weighted-Ensemble Precipitation (MSWEP) against ground-based data—with respect to their performance in detecting precipitation and drought patterns in the Great Ruaha River Basin (GRRB), Tanzania (1983–2020). Statistical metrics including the Pearson correlation coefficient (r), mean error (ME), root mean square error (RMSE), and bias were employed to assess the performance at daily, monthly, seasonal (wet/dry), and annual timescales. Most of the RS products exhibited lower correlations (r < 0.5) at daily timestep and low RMSE, bias, and ME. Monthly performance improved substantially (r > 0.8 at most stations) particularly during the wet season (r = 0.52–0.82) while annual and dry-season performance declined (r < 0.5 and r < 0.3, respectively). Performance under RMSE, bias, and ME declined at higher timescales, particularly during the wet season and annually. CHIRPS, MSWEP, and PERSIANN generally overestimated precipitation while TAMSAT consistently underestimated it. Spatially, CHIRPS and MSWEP reproduced coherent basin-scale patterns of drought persistence, with longer dry-spells concentrated in the northern, central, and western parts of the basin and shorter dry-spells in the eastern and southern regions. Trend analysis further revealed that most products captured consistent large-scale changes in dry-spell characteristics, although localized drought events were more variably detected. CHIRPS and MSWEP showed superior performance especially in capturing monthly precipitation patterns and major drought events in the basin. Most products struggled to detect extreme dry conditions with the exception of CHIRPS and MSWEP at certain stations and periods. Based on these findings, CHIRPS and MSWEP are recommended for drought monitoring and water resource planning in the GRRB. Their appropriate use can help water managers make informed decisions, promote sustainable resource use, and strengthen resilience to extreme weather events. Full article

Recent studies have highlighted the potential for production of an alternative sodium silicate in powder obtained by mixing NaOH with rice husk ash, followed by a dissolution and drying process. This alternative sodium silicate, when mixed with metakaolin and dried under special conditions, results in an eco-friendly one-part alkali-activated binder (OPAAB). However, the durability performance of OPAAB incorporating RHA-derived sodium silicate remains largely unexplored. This study focuses on an experimental investigation of OPAAB mortar durability, analyzing permeability, high-temperature exposure, wet-and-dry cycles, and resistance to aggressive environments (sulfate and acid attack). A two-part mix mortar made with the same precursors was used as a reference. It was found that the OPAAB mortars were not affected by the wet-and-dry cycles nor the sulfate attack. Exposure to high temperature (900 °C for 1 h) did not cause specimen failure, which had a residual compressive strength higher than 5 MPa. Finally, exposure to sulfuric acid for 56 days decreased the mechanical strength of the mortars, but all the specimens maintained a residual compressive strength higher than 4 MPa. The durability performance of the mortars produced with OPAAB incorporating RHA-derived sodium silicate was similar to the two-part mix mortars (reference), demonstrating technical feasibility and advancing the understanding of durability aspects for application in civil construction. Full article

Arsenic (As) accumulation in rice (Oryza sativa L.) is considered a major environmental and food safety concern, particularly in flooded agroecosystems where reducing conditions mobilize As from soils. Portugal is one of Europe’s rice producers, especially in the Tejo, Almansor, and Sorraia valleys. As such, this study evaluates As pathways across 5000 ha of rice fields in the Tagus, Sorraia, and Almansor alluvial plains by combining soil, water, and plant analyses with a geostatistical approach. The soils exhibited consistently elevated As concentrations (mean of 18.9 mg/kg), exceeding national reference values for agricultural soils (11 mg/kg) and forming a marked east–west gradient with the highest levels in the Tagus alluvium. Geochemical analysis showed that As is strongly correlated with Fe (r = 0.686), indicating an influence of Fe-oxyhydroxides under oxidizing conditions. The irrigation waters showed low As (mean of 2.84 μg/L for surface water and 3.51 μg/L for groundwater) and predominantly low sodicity facies, suggesting that irrigation water is not the main contamination vector. In rice plants, As accumulation follows the characteristic organ hierarchy roots > stems/leaves > grains, with root concentrations reaching up to 518 mg/kg and accumulating progressively in the maturity phase. Arsenic content in harvested rice grains was 266 μg/kg (with a maximum of 413.9 μg/kg), being close to EU maximum limits when considering typical inorganic As proportions, assuming 60 to 90% inorganic fraction. Together, the findings highlight that a combined approach is essential, and identify soil geochemistry (and not irrigation water) as the primary source of As transfer in those agroecosystems, due to the flooded conditions that trigger the reductive dissolution of Fe oxides, releasing As. Additionally, the results also identified the need for targeted monitoring in areas of elevated As content in soils and support future mitigation through As speciation analysis, cultivar selection, improved fertilization strategies, and water-management practices such as Alternate Wetting and Drying (AWD), to ensure the long-term food safety. Full article

As exposed bedrocks commonly interface with the soil directly, lacking a transition layer, cracks at rock–soil interface cracks (RSI-Cracks), are well-developed, particularly following wet–dry alternation in karst critical zones. However, inadequate understanding of the influence of RSI-Cracks on multi-path runoff generation around bedrocks has hindered an in-depth comprehension of subsurface-dominated hydrological processes in karst areas. To address this gap, we developed micro-slope models replicating rock–soil interfacial configurations by building upon field investigations. Two conditions, namely, the presence and absence of RSI-Cracks, were incorporated, with rain intensity and rock surface inclination as experimental conditions. Our results indicate that RSI-Cracks significantly alter the runoff output (p < 0.05), exacerbating subsurface water leakage. Compared with that on slopes without RSI-Cracks, the proportion of surface runoff on slopes with RSI-Cracks is reduced, with a reduction range of 4 to 46%. Conversely, RSI-Cracks promote an increase in the proportion of outflow at the rock–soil interface (RSI flow), with an increase range of 7 to 38%. This is an important reason for the aggravation of subsurface water leakage through RSI-Cracks. However, there is no significant change in the water loss caused by internal soil seepage on slopes with or without RSI-Cracks. These findings provide novel insights into underground water loss, with valuable implications for the construction and improvement of hydrological models in karst areas. Full article

The Eocene fourth member of the Shahejie formation (Es4x) in the Bonan Depression, Bohai Bay Basin, records syn-rift sedimentation under alternating arid and humid climates. It provides insight into how orbital-scale climatic fluctuations influenced tectonics, facies patterns, and reservoir distribution. This study integrates 406 m of core data, 92 thin sections, 450 km² of 3D seismic data, and multiple geochemical proxies, leading to the recognition of five facies associations (LFA): (1) alluvial fans, (2) braided rivers, (3) floodplain mudstones, (4) fan deltas, and (5) saline lacustrine evaporites. Three major depositional cycles are defined within the Es4x. Seismic reflections, well-log patterns, and thickness trends suggest that these cycles represent fourth-order lake-level fluctuations (0.8–1.1 Myr) rather than short 21-kyr precession rhythms. This implies long-term climate and tectonic modulation, likely linked to eccentricity-scale monsoon variability. Hyperarid phases are marked by Sr/Ba > 4, δ¹⁸O > +4‰, and thick evaporite accumulations. In contrast, Sr/Ba < 1 and δ¹⁸O < −8‰ reflect humid conditions with larger lakes and enhanced fluvial input. During wet periods, rivers produced sand bodies nearly 40 times thicker than in dry intervals. Reservoir quality is highest in braided-river sandstones (LFA 2) with 12%–19% porosity, preserved by chlorite coatings that limit quartz cement. Fan-delta sands (LFA 4) have <8% porosity due to calcite cementation, though fractures (10–50 mm) improve permeability. Floodplain mudstones (LFA 3) and evaporites (LFA 5) act as seals. This work presents a predictive depositional and reservoir model for arid–humid rift systems and highlights braided-river targets as promising exploration zones in climate-sensitive basins worldwide. Full article

Constructed wetlands (CWs), increasingly adopted as nature-based solutions (NBS) for wastewater treatment, require a rigorous assessment of the durability and structural performance of the materials used in their supporting systems. In contrast to the extensive literature addressing hydraulic efficiency and contaminant removal, the structural behavior of CWs has been scarcely examined, with existing studies offering only general references to reinforced concrete and masonry and lacking explicit design criteria or deterioration analyses. This study integrates evidence from real-world CW installations with a systematic review of 31 studies on the degradation of cementitious materials in analogous environmental conditions, following PRISMA 2020 guidelines, with inclusion criteria based on quantified wastewater-related exposure conditions (e.g., chemical aggressiveness, persistent saturation, and biogenic activity). Results indicate that reinforced concrete, despite its structural capacity, is susceptible to biogenic corrosion, accelerated carbonation, and sulfate–chloride attack under conditions of persistent moisture, with reported degradation rates in analogous wastewater infrastructures on the order of millimeters per year for concrete loss and tens of micrometers per year for reinforcement corrosion. Masonry structures, similarly, exhibit performance constraints when exposed to mechanical overloads and repeated wetting–drying cycles. In contrast, emerging alternatives—such as nanomodified matrices and concretes incorporating supplementary cementitious additives—demonstrate potential to enhance durability while contributing to a reduced carbon footprint, without compromising mechanical strength. These findings reinforce the need for explicit structural design criteria tailored to CW applications to improve sustainability, durability, and long-term performance. Full article

Water scarcity in semi-arid regions necessitates accurate soil water modeling to optimize irrigation management. This study compares three HYDRUS-1D parameterization approaches—based on the drying-branch soil water retention curve (SWRC), wetting-branch SWRC (using Shani’s drip method), and inverse modeling—to simulating soil water content at 15 cm and 45 cm depths under center-pivot irrigation in a semi-arid region. Field experiments in three maize fields provided daily soil water, soil hydraulic, and meteorological data. Inverse modeling achieved the highest accuracy (NRMSE: 2.29–7.40%; RMSE: 0.006–0.023 cm³ cm⁻³), particularly at 15 cm depth, by calibrating van Genuchten parameters against observed water content. The wetting-branch approach outperformed the drying branch at the same depth, capturing irrigation-induced wetting processes more effectively. Statistical validation confirmed the robustness of inverse modeling in reproducing temporal patterns, while wetting-branch data improved deep-layer accuracy. The results demonstrate that inverse modeling is a reliable approach for soil water simulation and irrigation management, whereas the wetting-branch parameterization offers a practical, field-adaptable alternative. This study provides one of the first side-by-side evaluations of these three modeling approaches under real-world semi-arid conditions. Full article

This study investigates premature fatigue failure in rocker arm gears of large-mining-height shearers operating at alternating ±45° working angles, where insufficient lubrication generates non-uniform thermal -stress fields. In this study, an integrated multiphysics framework combining transient thermal–fluid–structure coupling simulations with fatigue life prediction is proposed. Transient thermo-mechanical coupling analysis simulated dry friction conditions, capturing temperature and stress fields under varying speeds. Fluid–thermal–solid coupling analysis modeled wet lubrication scenarios, incorporating multiphase flow to track oil distribution, and calculated convective heat transfer coefficients at different immersion depths (25%, 50%, 75%). These coupled simulations provided the critical time-varying temperature and thermal stress distributions acting on the gears (Z6 and Z7). Subsequently, these simulated thermo-mechanical loads were directly imported into ANSYS 2024R1 nCode DesignLife to perform fatigue life prediction. Simulations demonstrate that dry friction induces extreme operating conditions, with Z6 gear temperatures reaching over 800 °C and thermal stresses peaking at 803.86 MPa under 900 rpm, both escalating linearly with rotational speed. Lubrication depth critically regulates heat dissipation, where 50% oil immersion optimizes convective heat transfer at 8880 W/m²·K for Z6 and 11,300 W/m²·K for Z7, while 25% immersion exacerbates thermal gradients. Fatigue life exhibits an inverse relationship with speed but improves significantly with cooling. Z6 sustains a lower lifespan, exemplified by 25+ days at 900 rpm without cooling versus 50+ days for Z7, attributable to higher stress concentrations. Based on the multiphysics analysis results, two physics-informed engineering optimizations are proposed to reduce thermal stress and extend gear fatigue life: a staged cooling system using spiral copper tubes and an intelligent lubrication strategy with gear-pump-driven dynamic oil supply and thermal feedback control. These strategies collectively enhance gear longevity, validated via multiphysics-driven topology optimization. Full article

Background/Objectives: Polymeric barrier membranes (BMs) are usually used in guided bone regeneration to isolate the bone defect from the surrounding tissue, favoring bone apposition. This study proposes a third-generation BM made of polycaprolactone (PCL), loaded with different concentrations of nano-hidroxyapatite (nHAP) and gentamicin (GEN), and fabricated by electrospinning. Methods: The mechanical properties of the polymer, together with the fabrication procedure, offer porosity with interconnectivity to permit cell adhesion and proliferation. Bacterial contamination of the BM can induce infection at the bone level, leading to unfavorable clinical outcomes of the regeneration procedure. Results: Therefore, BMs have been proposed as carriers for local GEN antibiotic therapy, demonstrating antibacterial properties against S. aureus, S. mutans, and P. aeruginosa, depending on the drug concentration, while being negligibly affected by the nHAP content. X-ray diffraction, FTIR-ATR, and SEM allowed for BM structural characterization, demonstrating the presence of GEN/nHAP and establishing the fiber diameter, which influences the mechanical properties in dry and wet conditions and the drug release behaviorA BM cytotoxicity assessment, performed over 1 and 5 days, revealed that a high nHAP concentration provided protection against cytotoxicity, in contrast to GEN, and that cell proliferation and cell adhesion increased in the presence of nHAP. The BM’s bioactivity was demonstrated by mineralization after 21 days in simulated body fluid in an SEM/EDX analysis. Conclusions: The electrospun 15 wt.% nHAP and 2 wt.% GEN-loaded third-generation BM could be a promising alternative for guided bone regeneration. Full article

Vineyard sustainability increasingly focuses on transitioning from traditional soil management practices, such as tillage and herbicides, to environmentally friendly methods like cover cropping and mulching. While this strategy works in cool climates with abundant rainfall, its application in warmer areas is not advisable due to potential disadvantages, such as water and nutrient competition from cover crops, which may outweigh the benefits. We examine the pros and cons of vineyard tillage, including data on evaporation rates from wet and dry tilled soils. We explore methodologies to quantify competition between vine roots and grass roots, focusing on distinguishing native versus spontaneous vegetation, duration and extent of cover cropping, species used in sown mixtures, and cover crop water use rates. Novel soil management practices are discussed as alternatives to traditional green manuring, such as mid-row rolling and sub-row sward mulching. The review updates recent approaches for establishing native or sown under-vine cover crops, which, with irrigation, might control native weeds while colonizing shallow soil, allowing grapevine roots to penetrate deeper, moistened soil layers. Promising grasses include creeping species such as Glechoma hederacea, Trifolium subterraneum, and Hieracium pilosella. Finally, we describe three soil management protocols: two suited to dry farm conditions and one involving blue water availability, which may mitigate cover crop competition for water and nutrients while maintaining benefits such as reduced soil erosion, increased soil organic matter, carbon sequestration, and improved machinery access. Full article

The incidence of duckweed (Lemna minor L.) outbreaks in paddy fields has increased in recent years, but how it impacts rice production is still under debate. This study assessed duckweed’s effects on rice yield and quality under different fertilizer regimes: organic fertilizer (OF), chemical fertilizer (CF), a mix (one-third OF and two-thirds CF based on nitrogen content, COF), and no fertilizer (NF) as a control. For each fertilizer regime, two duckweed treatments were applied: duckweed coverage (Duckweed) and no duckweed coverage (Control). A light wet–dry alternate irrigation method was used in the experimental field. Averaged across all fertilizer treatments, duckweed coverage in paddy fields increased grain yield by 8.3%, mainly due to increased panicle density. Duckweed coverage increased chalky grain percentage by 17.0% under NF, but decreased it by 33.7% under CF, with nonsignificant changes under COF and OF conditions. Similar fertilizer-by-duckweed interactions were also found for chalkiness degree, white degree, breakdown and setback values of the starch rapid visco analyzer (RVA) profile, palatability index, and protein and amino acid concentrations. Duckweed coverage decreased protein and amino acid concentrations but improved the taste of cooked rice under NF, while the opposite trend was observed under CF. Duckweed coverage significantly decreased copper and zinc concentrations in milled rice, which may aggravate the “hidden hunger” risk for rice consumers. Full article

Traffic accidents caused by black ice have become a serious public safety concern due to their high fatality rates and the limitations of conventional detection systems under low visibility. Millimeter-wave (mmWave) radar, capable of operating reliably in adverse weather and lighting conditions, offers a promising alternative for road surface monitoring. In this study, six representative road surface conditions—dry, wet, thin-ice, ice, snow, and sludge—were experimentally implemented on asphalt and concrete specimens using a temperature and humidity-controlled chamber. mmWave radar data were repeatedly collected to analyze the temporal variations in reflected signals. The acquired signals were transformed into range-based spectra using Range-Fast Fourier Transform (Range-FFT) and converted into statistical features and graphical representations. These features were used to train and evaluate classification models, including Extreme Gradient Boost (XGBoost), Light Gradient-Boosting Machine (LightGBM), Convolutional Neural Networks (CNN), and Vision Transformer (ViT). While machine learning models performed well under dry and wet conditions, their accuracy declined in hazardous states. Both CNN and ViT demonstrated superior performance across all conditions, with CNN showing consistent stability and ViT exhibiting competitive accuracy with enhanced global pattern-recognition capabilities. Comprehensive robustness evaluation under various noise and blur conditions revealed distinct characteristics of each model architecture. This study demonstrates the feasibility of mmWave radar for reliable road surface condition recognition and suggests potential for improvement through multimodal sensor fusion and time-series analysis. Full article

The growing environmental impact of plastic waste and the high energy consumption in traditional asphalt production have driven the search for more sustainable alternatives in road construction. This systematic review evaluates the incorporation of recycled plastics into Hot Mix Asphalt (HMA) and Warm Mix Asphalt (WMA), focusing on their effects on mechanical performance and environmental outcomes. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA/ScR) methodology, 39 studies published between 2012 and 2023 were analyzed to compare plastic types, incorporation methods (dry, wet, and pyrolysis), and dosage levels. Results show that plastics such as Polyethylene Terephthalate (PET), Low-Density Polyethylene (LDPE), and Polypropylene (PP) can improve stiffness, rutting resistance, and fatigue life. WMA technologies, while less commonly applied, offer significant environmental advantages by reducing greenhouse gas emissions and energy consumption. The review highlights the critical role of plastic type, blending method, and local conditions in optimizing performance. Overall, integrating recycled plastics into asphalt mixtures presents a promising pathway toward more durable and sustainable pavement infrastructure. Full article

Palatability is a critical determinant of pet food performance, directly influencing voluntary intake, nutrient utilization, and therapeutic efficacy. In this systematic review, we examine peer-reviewed research publications, patent filings, and commercial product data pertaining to palatant technologies in dry and wet pet food from 2014 to 2024. Major palatant classes—including fats, proteins, yeast extracts, and novel plant-derived or insect-based hydrolysates—are evaluated for their physicochemical properties, flavor-release mechanisms, and stability during processing. We analyze formulation techniques such as microencapsulation, Maillard-reaction enhancement, and multilayer coating systems, focusing on their impact on aromatic compound retention and palatability consistency. Patent landscape assessment identifies over 15 key innovations in delivery systems, life-stage-specific palatant modulation, and dual-phase release architectures. Dual-phase release architectures are defined as systems that deliver active compounds in two sequential phases, such as immediate and sustained release. Sensory evaluation methodologies—ranging from multivariate preference mapping to descriptive analysis—are critically appraised to correlate human-panel metrics with canine and feline feeding behavior. We also discuss strategic integration of palatants at different processing stages (pre-conditioning, extrusion, and post-extrusion) and the challenges of balancing taste masking with nutritional requirements, particularly in formulations containing alternative proteins for sustainability. Despite rapid market growth in functional palatant-infused products, peer-reviewed literature remains relatively limited, suggesting opportunities for further research on species-specific flavor drivers, synbiotic flavor–nutrient interactions, and novel delivery platforms. This comprehensive overview of palatant science, patent innovations, and market evolution provides evidence-based guidance for researchers, formulators, and veterinarians seeking to optimize organoleptic properties and consumer acceptance of next-generation pet foods. Full article

Recently, there has been a growing interest in using agricultural and forestry residues to cultivate Flammulina filiformis. However, there is limited research on cultivating F. filiformis with soybean straw as a substrate. This study systematically optimized the cultivation formula for F. filiformis using soybean straw as the raw substrate and explored the effects of the water content, carbon-to-nitrogen ratio (C/N ratio), substrate particle size, and substrate loading on its growth and development. By replacing corncob, wheat bran, and soybean hulls with soybean straw and increasing the proportion of rice bran, the cultivation formula for growing F. filiformis was optimized. We found that the maximum fruiting body yield of 405 g (330 g dry substrate per bottle) and a biological efficiency of 122.73% were achieved using a substrate mixture of 25% soybean straw, 20% corncob, 20% cottonseed hull, 25% rice bran, 8% wheat bran, 1% CaCO₃, and 1% shellfish powder. The yield and biological efficiency of fruiting bodies cultivated on the substrate containing 25% soybean straw did not show significant differences compared to the control group. However, the cultivation formula containing 25% soybean straw yielded F. filiformis with significantly higher levels of amino acids, essential amino acids, and fat. These findings suggest that the 25% soybean straw substrate formulation can serve as a viable alternative to the control formulation for the cultivation of F. filiformis, although variations in the nutritional composition exist. Based on this optimized formula, an optimal biological efficiency can be achieved with a substrate-to-water ratio of 1:1.7, a wet substrate loading amount of 940 g (in a 1250 mL cultivation bottle), and a soybean straw particle size range of 6–8 mm. The optimal C/N ratio for cultivating F. filiformis using soybean straw ranges from 27:1 to 32:1. Additionally, orthogonal experiments revealed that the nitrogen content significantly affected the fruiting body yield, stipe length, and stipe diameter, while the water content mainly affected the pileus diameter, pileus thickness, and number of fruit bodies. Under defined conditions (dry substrate loading volume of 337 g (in a 1250 mL cultivation bottle), a substrate-to-water ratio of 1:1.6, and a C/N ratio of 26:1), the maximum yield and biological efficiency per bottle reached 395 g and 117.21%, respectively. Our findings indicate that the F. filiformis cultivation using soybean straw as the raw substrate exhibits a promising performance and extensive application potential. Full article