Search Results (432)

The Upper Oligocene–Lower Miocene Alibonca Formation retains an essential record of intricate relationships among carbonate platform evolution, volcanic–sedimentary inflow, and high-purity silica deposition. This study examines the stratigraphic structure, paleoenvironmental development, and industrial viability of the Ağın diatomite deposits using comprehensive sedimentological, mineralogical, and geochemical investigations. Stratigraphic evidence indicates that the formation commenced with Early Miocene alluvial fan and shallow restricted marine sub-basin sedimentation prior to evolving into a significant marine incursion. This marine phase created a resilient carbonate platform structure consisting of reef-core, fore-reef, and back-reef sub-environments. Simultaneously, vigorous regional synsedimentary volcanism introduced high-flux silica pulses into the basin, acting as a major catalyst for diatom proliferation and high biological productivity within a restricted sub-basin setting. Geochemical analyses indicate that these bright white, diatomite deposits formed in conjunction with potassium-rich clays in a relatively deep, low-energy, and confined sub-basin of the Alibonca Sea. The high concentration of bulk SiO₂ and low trace element baselines are consistent with a high-purity deposional system and a low total rare earth element (ΣREE) abundance. However, their relatively high Al₂O₃ and K₂O contents indicate significant volcanic and terrigenous detrital input together with authigenic clay mineral formation during diatomite deposition, classifying the deposits as clay-bearing (argillaceous) diatomites rather than exceptionally pure diatomites. Chemical Index of Alteration (CIA) values indicate moderate continental chemical weathering under mostly hot and humid paleoclimatic conditions. The rapid terrestrial runoff and nutrient influx stimulated significant diatom growth before the ultimate late Early Miocene marine regression, transforming the area into a subaerial, volcanically influenced terrestrial environment. The Ağın deposits exemplify intra-platform marine silica sinks, demonstrating how tectonic–magmatic influences can surpass typical carbonate factory conditions to provide economically valuable biogenic mineral resources. Full article

Sustainable water remediation requires catalytic strategies that remove contaminants efficiently while reducing chemical input, byproduct formation, and ecological disturbance. Conventional radical-dominated advanced oxidation processes can rapidly degrade pollutants, but their reliance on high oxidant dosages and freely diffusing reactive oxygen species often causes matrix quenching, non-selective oxidation, low oxidant utilization, and potential ecological risks. Mild interfacial catalysis provides a materials-chemistry strategy to regulate oxidative intensity and direct contaminant transformation under environmentally relevant conditions. In this review, mild catalysts are defined by pathway-selective, interfacially confined, and environmentally compatible oxidation rather than by low dosage alone. Representative non-radical or low-intensity pathways, including singlet oxygen generation, surface-mediated electron transfer, high-valent metal–oxo species, and direct oxidative transfer processes, are discussed in relation to active-site structure, oxidant utilization, matrix tolerance, and byproduct control. We further summarize how coordination environments, defect chemistry, heteroatom configurations, nanoconfinement, and immobilized interfaces regulate reactive-species formation and interfacial charge transfer. Key material platforms, including single-atom catalysts, heteroatom-doped carbons, defect-engineered oxides, catalytic membranes, hydrogels, and floating or immobilized composites, are evaluated from mechanistic and application-oriented perspectives. Finally, catalyst regeneration, cost, microbial community responses, algae–bacteria balance, ecotoxicity, and long-term safety are discussed to guide sustainable aquatic ecosystem restoration. Full article

Against the dual objectives of food security and sustainable agriculture, this study examines how agricultural machinery services—China’s primary organized mode of agricultural production—affect agricultural carbon emissions. Using panel data covering 30 provinces in China from 2010 to 2022, this study applies two-way fixed effects, mediation, and moderation models to investigate the effects of these services on carbon emissions as well as the mechanisms involved. The results show: (1) Both carbon emissions and the level of machinery services in China differ by region and over time. Carbon emissions are stabilizing, while machinery services are steadily improving. Both variables cluster in certain areas. (2) Machinery services exhibit a significant inverted U-shaped impact on carbon emissions. As the level of machinery services grows, emissions first rise, then fall. (3) The emission reduction impact of machinery services varies widely. It differs across topographic relief, farmland types, and grain crop types, but the inverted U-shaped relationship remains in most cases. (4) The efficiency of the division of labor and agricultural chemical input intensity partly explain the effect. They help reduce emissions by enabling labor substitution and lower input levels. (5) Large-scale agricultural operations strongly influence how machinery services affect carbon emissions. To accelerate the low-carbon sustainable transformation of Chinese agriculture, efforts should prioritize establishing a differentiated, regionally tailored agricultural machinery socialized service system, improving service efficiency and green development capacity, and optimizing large-scale land management structures. Full article

Femtosecond laser surface texturing offers a promising route to tailor the functionality of bio-based wood coatings, yet the interplay between coating composition and laser processing remains poorly understood. In this study, bio-based epoxy coatings with eventual micronized wax additives were textured using a femtosecond laser to investigate the effects of laser processing parameters on pattern formation and resulting hydrophobicity. The epoxy coatings containing PE, PE/PTFE, HDPE, and rice bran waxes at 1, 5, and 7 wt.-% were characterized in terms of morphology, roughness, wettability, and chemical stability, followed by systematic variation of pulse repetition rate and laser power. The results reveal that the ablation threshold strongly depends on intrinsic coating properties. Ablation resistance increases with surface roughness and wax melting enthalpy, reflecting the role of phase transition energy in laser–matter interaction. The wax-filled coatings exhibit a transition from melting-dominated behavior at low energy input to ablation-dominated behavior at a higher energy. Laser texturing enhances hydrophobicity in parallel with theoretical values calculated from the Cassie–Baxter wetting model, with the highest hydrophobicity achieved for coatings combining intrinsic hydrophobicity and stable pattern formation. Chemical analysis confirms limited degradation of the epoxy matrix without significant carbonization, while wax additives provide partial thermal shielding. Overall, this work demonstrates clear options for tailoring surface morphology and wettability of hydrophobic polymer coatings through controlled femtosecond laser processing. Full article

Rice–fish co-culture is widely promoted for mitigating nitrous oxide (N₂O) emissions from paddy soils, yet how the duration of co-culture reshapes the underlying nitrogen-cycling microbial community under low-nitrogen input remains poorly understood. This study aimed to (i) characterize how co-culture duration alters the rhizosphere microbial functional potential for N₂O production and consumption, and (ii) identify the water and soil variables linking fish activity to that response. The experiment was conducted during the 2024 rice growing season in the Qingtian rice–fish system (Zhejiang Province, China), a traditional agricultural heritage system managed without chemical fertilizer or supplementary feed. Three treatments (i.e., rice monoculture, first-year co-culture, and long-established (~10-year) co-culture) were compared using six independently bunded replicate plots each. Rhizosphere soils were collected at the tillering, heading and maturity stages for shotgun metagenomic profiling of nitrogen-cycling functional genes, with concurrent measurement of N₂O flux and water and soil physicochemical properties. Fluxes were uniformly low and did not differ among treatments (p > 0.05), defining a substrate-limited baseline. Against this baseline, first-year co-culture induced a coordinated shift toward complete denitrification (nosZ increased by 25–33% across all stages; nosZ/(nirK + nirS) rose to 0.99 at heading), associated with a transient water organic carbon pulse and dissolved-oxygen availability. The long-established system resembled monoculture, indicating a non-monotonic, duration-dependent response. Full article

Partially replacing cement with mine tailings offers a sustainable strategy for solid waste resource utilization. As a cement admixture, the compressive strength of tailings-based cement materials serves as a critical performance indicator. Machine learning (ML) techniques offer high efficiency, cost-effectiveness, and superior predictive accuracy. However, variations in the chemical composition of tailings often introduce uncertainties into model predictions. Consequently, this study developed an integrated approach incorporating chemical composition and activation methods as input parameters. Four optimized ML models were deployed to predict the compressive strength of tailings-based cementitious materials. Multiple metrics were employed to evaluate model performance, which identified the PSO-XGBoost model as the superior predictive architecture. SHAP analysis revealed that mechanical grinding, NaOH concentration, and the proportions of gypsum and tailings were the primary features influencing compressive strength. Experimental validation yielded a low prediction error of 8.7%, confirming the model’s high predictive accuracy. This research establishes a robust framework for predicting the strength of tailings-based cementitious materials, providing a theoretical foundation for solid waste upcycling. Full article

Maize, as a major cereal crop in China, is vital for national food security, and appropriate nitrogen fertilization is essential for its growth and yield. Avoiding excessive nitrogen fertilizer application while maintaining productivity remains a critical challenge for sustainable agriculture. Although straw returning is widely adopted to reduce chemical fertilizer inputs, its effectiveness is often regionally constrained. In the West Liaohe Plain, low temperature and spring drought limit straw decomposition and nutrient release, making it difficult to reduce nitrogen fertilizer input and improve fertilizer use efficiency. Therefore, this study examined the effects of different nitrogen management modes on straw decomposition, nutrient release, mineral fertilizer substitution potential, soil available nutrients, and maize yield under shallow buried drip irrigation with integrated water and fertilizer management. A field experiment was conducted with five nitrogen (N) fertilizer management treatments: a conventional fertilization treatment (CK), in which 15% of total N was applied as starter fertilizer; two increased starter N treatments, in which 30% (30%N) and 45% (45%N) of total N were applied as starter fertilizer; and two organic substitution treatments, in which 30% (30%ON) and 45% (45%ON) of mineral N fertilizer were substituted with decomposed sheep manure based on equivalent total N input. Straw decomposition and nutrient release were measured using the nylon mesh bag method and fitted with an exponential decay model. The mineral fertilizer substitution potential was estimated based on straw nutrient release, while soil available nutrient dynamics in the 0–40 cm soil layer were analyzed, and the Mantel test and PCA were used to assess their relationships. Organic substitution promoted straw decomposition. The 30%ON treatment showed the highest rate at 70.91%, which was 19.2% higher than that of CK, and it exhibited a higher theoretical maximum decomposition rate (a), higher decomposition rate constant (k), and a shorter half-life. All treatments increased nutrient release and soil available nutrients, and organic substitution demonstrated stronger temporal persistence and more uniform vertical distribution among soil layers. The 30%ON treatment increased straw nutrient release by 4.8% to 18.2% and enhanced mineral fertilizer substitution potential. Although the 30%ON treatment did not increase yield in the first experimental year, it showed a significant yield advantage in the second year, which coincided with greater straw nutrient release and higher soil available nutrient levels under this treatment. Substituting 30% of mineral N fertilizer with organic fertilizer under shallow buried drip irrigation (300 kg N ha⁻¹) optimized the C/N balance of the input system and facilitated straw decomposition and nutrient release. The continuous accumulation of soil available nutrients under this treatment, together with sustained straw nutrient release, was associated with a significant yield advantage in the second experimental year. Therefore, the 30%ON treatment may represent an appropriate management strategy for coordinating straw resource utilization, soil fertility maintenance, and stable maize production in the West Liaohe Plain. Full article

One of the primary inputs to short-term mine planning is the block model, which includes estimated or simulated run-of-mine grades calculated using geostatistical techniques. The ore label is usually assigned to the blocks by analyzing cut-off grades, determined from the grades of the most important variable related to the mineral processed in the plant and sold as concentrate. Zones below the cut-off grade usually indicate low-recovery areas, but in some situations, the yield obtained has quantity and quality to be further used, paying its costs in the plant with a profit. Zones with values above the cut-off do not consistently guarantee mineral recovery, as even high-grade zones may prove non-recoverable due to contaminants that can affect the beneficiation process. These factors increase the complexity of mining planning, requiring consideration of geometallurgical properties in the selection and sequencing of blocks sent to the processing plant. This study presents a sequence of selected mineable blocks, with the yield estimated using neural networks applied to each simulated block containing the run-of-mine grades. This approach minimizes the metallurgical risk over short-term planning periods. New paradigms are proposed for short-term planning optimization, not relying solely on chemical variables but also incorporating geometallurgical variables. Full article

Groundwater resources in the Kingdom of Saudi Arabia (KSA) are important for meeting the needs of human communities, agriculture, and industry. In Western KSA, groundwater from coastal aquifers is an essential resource that complements desalinated seawater. Therefore, ensuring the quality and contamination of groundwater has emerged as a critical priority for preserving water security. The aim of this research is to evaluate the groundwater quality and its vulnerability to contamination within the Wadi Marawani Basin. To achieve this aim, water quality indices (WQIs), the DRASTIC model, and machine learning (ML) algorithms were employed alongside a Geographic Information System (GIS). The results of the chemical analysis of 64 water samples were used in these assessments. Furthermore, several input parameters were evaluated using the DRASTIC model to estimate the DRASTIC index (DI) and generate a groundwater vulnerability map. Three ML algorithms—specifically, a Multilayer Perceptron (MLP), a Random Forest (RF), and a Decision Tree (DT)—were utilized to forecast WQIs such as the total dissolved solids (TDS) and sodium adsorption ratio (SAR), in addition to the DRASTIC index (DI). The results revealed that around 36% of the samples were classified as fresh water (<1000 mg/L). The SAR ranged from 1.10 to 32.50, indicating that most samples were suitable for irrigation. Approximately 22% of the basin was classified as demonstrating high vulnerability, whereas about 78% demonstrated low-to-moderate vulnerability. Assessment of the ML models showed high predictive accuracy for the TDS, SAR, and DI. The MLP-Vul. model attained an R² value of 1.00 and RMSE value of 0.01, the RF-Vul. model achieved an R² of 0.94 and RMSE of 3.17, and the DT-Vul. model attained an R² of 0.92 and RMSE of 3.57. Although there was a minor increase in RMSE across all models during the testing phase, their predictive performance remained clear. Full article

Against the backdrop of global climate change and the “dual carbon” goals, the issue of agricultural greenhouse gas emissions has garnered increasing attention. As a major grain and oilseed crop in China, carbon emissions from soybean production have a significant impact on the green and low-carbon development of agriculture. Although research on agricultural carbon footprints has grown in recent years, existing studies have largely focused on single regions or specific stages of crop production, and analyses of the carbon footprint of production systems in China’s major soybean-producing regions remain relatively limited. This study employs the Life Cycle Assessment (LCA) methodology to calculate and analyze the carbon footprint of soybean production systems across China’s 10 major soybean-producing provinces, utilizing agricultural input data from 2014 to 2023. The study establishes a carbon footprint accounting system based on two key aspects: carbon emissions from agricultural inputs and soil N₂O emissions. It further analyzes the temporal trends, regional variations, and contribution characteristics of each component within the carbon footprint. The results indicate that the average carbon footprint of soybean production in China is approximately 528 kg CO₂eq/ha (ranging from 273 to 855) and 0.25 CO₂eq/kg of soybean (ranging from 0.13 to 0.46). Specifically, the carbon footprint per unit of area and yield declined simultaneously, indicating a continuous improvement in the low-carbon efficiency of soybean production. Spatially, there are significant regional differences in the carbon footprint of soybean production. Henan, Anhui, and Inner Mongolia have relatively low carbon footprints, while Shaanxi and Shanxi have relatively high levels. In terms of composition, chemical fertilizer inputs and soil N₂O emissions are the primary sources of the carbon footprint in soybean production, with chemical fertilizer inputs being the largest source, accounting for approximately 40–60%, and soil N₂O emissions being the second major source. Overall, differences among regions in natural conditions, agricultural input structures, and production methods result in distinct regional characteristics in the carbon footprint composition. The findings of this study provide a scientific basis for the low-carbon transition of China’s soybean production system and serve as a reference for the formulation of policies related to green agricultural development. Full article

Croatia’s diverse agroecological zones, from Mediterranean coastal areas to continental lowlands, enable the cultivation of a broad portfolio of traditional fruit species that contribute simultaneously to biodiversity conservation, rural livelihoods, and the development of value-added food and beverage products. This review compiles and harmonizes evidence on six economically and culturally relevant crops and product chains—grapevine and wine, apple, pear, quince, sour cherry, mulberry, and plum with the traditional spirit šljivovica—focusing on genetic resources and cultivar diversity, agronomic and environmental performance, bioactive composition and potential health relevance, processing routes and by-product valorization, and the socio-economic roles of geographical indications, gastronomy, and tourism. Across species, the literature highlights recurring sustainability levers: safeguarding indigenous and old cultivars as reservoirs of adaptive traits under climate change; reducing chemical inputs through cultivar choice, organic and low-input systems, cover crops, and resistant genotypes; strengthening circularity by converting pomace and other residues into spirits, vinegars, functional ingredients, feed, compost, or energy carriers; and increasing rural value capture through branding, protected origin schemes, and experiential tourism. At the same time, production systems face shared constraints, including fragmentation of holdings, labour shortages, phytosanitary pressures, and the need to optimize processing technologies to preserve sensory and bioactive quality while meeting safety and regulatory requirements. By integrating crop-specific evidence with cross-cutting sustainability themes, this review outlines a coherent framework for positioning traditional Croatian fruit resources and their derived products within contemporary sustainable food system transitions. Full article

The dissimilar joining of aluminum alloy and carbon fiber-reinforced polymer (CFRP) is critical for lightweight manufacturing in transportation and aerospace sectors, yet it remains challenging due to their substantial differences in physical and chemical properties. This paper systematically reviews friction stir welding (FSW) of aluminum alloy and CFRP, and compares it with laser welding, induction welding, resistance welding, and ultrasonic welding. The comparative analysis indicates that while each alternative process presents distinct limitations in thermal management, heating uniformity, or joint configuration, FSW demonstrates the most balanced overall performance, uniquely combining single-pass long-distance capability, low heat input, and broad industrial applicability. Through systematic parametric analysis, the optimal FSW processing window is quantitatively established as a tool rotation speed of 1200–1500 rpm combined with a traverse speed of 30–50 mm/min. Under these optimized conditions, the CFRP side remains below its thermal degradation threshold of 350 °C, the defect volume fraction is reduced from 12% to below 3%, and the maximum joint tensile strength reaches 78 MPa, representing 65% of the base CFRP strength. The interfacial bonding mechanisms are identified as mechanical interlocking and localized chemical bonding, which however cover only approximately 30% of the interfacial area. Optimization strategies, including surface modification, auxiliary structures, nanoparticle reinforcement, and external field assistance, are evaluated for their effectiveness in improving joint quality. Finally, critical challenges and future research directions toward engineering application are outlined. Full article

This review is part of a series of studies on short-lived radionuclide accumulation in aquatic organisms following nuclear weapons testing, routine facility discharges, and accidental releases. It examines the pathways of uptake, accumulation, and internal redistribution of ¹²⁵Sb, ¹³¹I, ¹⁴¹Ce, and ¹⁴⁴Ce in fish representing different ecological groups. The analysis combines published literature data with our original findings obtained from studies conducted in the cooling pond of the Chornobyl Nuclear Power Plant and the Kaniv Reservoir during the post-accident period. It has been established that radionuclide accumulation is governed by their physicochemical properties, environmental speciation, and the trophic characteristics of fish. ¹²⁵Sb demonstrates high bioavailability and accumulates in internal organs, gills, roe, and muscle depending on its chemical form in the aquatic environment. ¹³¹I is characterized by high solubility, rapid incorporation into biological processes, and transient retention in tissues. ¹⁴¹Ce and ¹⁴⁴Ce exhibit low mobility, strong association with particulate matter, and preferential accumulation in the gastrointestinal tract, external, and mineralized tissues. At the same time, the presence of ¹⁴⁴Ce in the muscle tissue of carnivores and piscivores suggests possible trophic transfer and does not exclude potential manifestations of limited biomagnification of this radionuclide under conditions of elevated environmental contamination. It has been determined that the ratio of ¹²⁵Sb to ¹⁴⁴Ce can be used to identify contamination sources: their co-occurrence is interpreted as evidence of fuel particle input, explaining their predominant localization in the gastrointestinal tract and, to a lesser extent, in external tissues. Conversely, their separate detection reflects differences in mobility and bioavailability. It has been shown that the principal pathways for the uptake of the investigated radionuclides by fish are particle ingestion and absorption from the dissolved phase; thus, trophic dilution predominates over biomagnification, although trophic transfer of ¹⁴⁴Ce cannot be excluded. Full article

Circulating fluidized bed boilers (CFBBs) are widely applied in energy, metallurgy, the chemical industry and other fields, mainly due to their high combustion efficiency and low pollution emissions. However, the CFBB combustion system, as a typical third-order plus time delay (TOPTD) system, has inherent characteristics: large inertia, significant time delays and strong coupling. Coupled with the difficulty in establishing an accurate mathematical model, traditional control methods struggle to achieve the desired control performance. Active disturbance rejection control (ADRC) has prominent advantages, such as low dependence on the controlled plant’s accurate model and strong disturbance rejection ability, but it has obvious limitations in dealing with systems with large inertia and large time delays. To address this problem, this paper proposes an input-compensated active disturbance rejection control (ICADRC) method. An input-compensated part composed of a second-order inertial link and a time delay link is introduced into the ESO input channel, which is specially optimized for the characteristics of TOPTD systems. A set of quantitative parameter tuning rules unique to ICADRC is established via the equivalent approximation method, and a dedicated MATLAB auto-tuning toolbox for ICADRC is developed for TOPTD systems. Simulation experiments are conducted on the CFBB combustion system, and the results show that the proposed ICADRC exhibits superior setpoint tracking performance, disturbance rejection performance and robustness compared with ADRC, DADRC, and SIMC-PI. Under nominal operating conditions, the ${\mathrm{IAE}}_{\mathrm{sum}}$ of ICADRC is reduced by 36.2% relative to DADRC and by 54.3% relative to SIMC-PI. Specifically, under fixed parameter perturbations, the variation amplitude of ICADRC’s performance index is only 2.1%, significantly lower than the 5.1% for DADRC, 6.1% for ADRC, and 7.3% for SIMC-PI. Full article

As agriculture moves towards green transformation and low-carbon production, the high energy consumption, environmental burden, and residue risks associated with conventional chemical fertilisers, pesticides, and disinfectants have become increasingly prominent. Non-thermal plasma (NTP) can generate reactive oxygen and nitrogen species (RONS) under near-ambient temperature and pressure conditions, while offering low chemical residue, high reactivity, and modular equipment design. It has therefore attracted growing attention in agricultural engineering and green agricultural input preparation. This review focuses primarily on studies published within the past five years, together with the selected foundational literature retrieved from Web of Science, Scopus, PubMed, MDPI, and ScienceDirect. It systematically examines the fundamental mechanisms, application modes, and representative agricultural scenarios of NTP, with particular emphasis on agricultural nitrogen fixation and fertilisation, seed treatment and seedling raising, crop growth regulation and protection, soil improvement and remediation, and postharvest preservation and safety treatment of agricultural products. Key technological advances are then summarised, including optimisation of discharge systems and reactor configurations, plasma–catalysis synergy, preparation of plasma-activated water (PAW) and plasma-activated mist (PAM), and the development and integration of specialised agricultural equipment. In addition, the current state-of-the-art (SOA) of artificial intelligence (AI) applications in plasma-process modelling, process-parameter optimisation, agricultural performance evaluation, and intelligent control is discussed. Existing evidence indicates that NTP is particularly relevant to controlled-environment agriculture, including greenhouse cultivation, hydroponics, and aeroponics, where discharge processes, water or nutrient solutions, and crop root-zone management can be coupled for in situ nitrogen supply, activated-medium preparation, and crop protection. However, reported effects remain strongly dependent on discharge type, energy input, reactive-species composition, treatment dose, crop species, cultivation system, and application route. Therefore, NTP-based agricultural technologies should be evaluated using consistent indicators, including energy consumption, product selectivity, reactive-species stability, treatment throughput, crop response, ecological safety, and system-level integration with AI and IoT. Future research should prioritise high-efficiency reactors, standardised evaluation frameworks, cross-scale mechanistic understanding, reliable datasets, and closed-loop intelligent control, thereby supporting the transition from laboratory studies to reproducible and application-oriented agricultural systems. Full article