Search Results (260)

With increasing global challenges related to water scarcity and phosphorus depletion, the recovery and reuse of wastewater-derived nutrients offer a sustainable path forward. This study evaluates the dual role of lanthanides (Ce³⁺ and La³⁺) in recovering phosphorus from municipal wastewater and supporting corn (Zea mays) cultivation through lanthanide phosphate (Ln-P) and lanthanide-reclaimed wastewater (LRWW, wastewater spiked with lanthanide). High-purity precipitates of CePO₄ (98%) and LaPO₄ (92%) were successfully obtained without pH adjustment, as confirmed by X-ray photoelectron spectroscopy (XPS) and energy-dispersive spectroscopy (EDS). Germination assays revealed that lanthanides, even at concentrations up to 2000 mg/L, did not significantly alter germination rates compared to traditional coagulants, though root and shoot development declined above this threshold—likely due to reduced hydrogen peroxide (H₂O₂) production and elevated total dissolved solids (TDSs), which induced physiological drought. Greenhouse experiments using desert-like soil amended with Ln-P and irrigated with LRWW showed no statistically significant differences in corn growth parameters—including plant height, stem diameter, leaf number, leaf area, and biomass—when compared to control treatments. Photosynthetic performance, including stomatal conductance, quantum efficiency, and chlorophyll content, remained unaffected by lanthanide application. Metal uptake analysis indicated that lanthanides did not inhibit phosphorus absorption and even enhanced the uptake of calcium and magnesium. Minimal lanthanide accumulation was detected in plant tissues, with most retained in the root zone, highlighting their limited mobility. These findings suggest that lanthanides can be safely and effectively used for phosphorus recovery and agricultural reuse, contributing to sustainable nutrient cycling and aligning with the United Nations’ Sustainable Development Goals of zero hunger and sustainable cities. Full article

This paper investigated the impact of repeated bushfire exposure on the properties of four different types of lightweight aggregate (i.e., expanded perlite, pumice, diatomite and expanded glass) masonry blocks for use in the external walls of bushfire shelters and buildings in bushfire-prone areas. First, the properties of cement, sand and lightweight aggregates were determined. Then, 15 different masonry block cement mixes—control, expanded perlite, pumice, diatomite and expanded glass mixes—were developed using the absolute volume method and lightweight aggregate cement mixes were developed by replacing sand in the control mix with lightweight aggregate on an equal volume basis. The test specimens cast included 100 mm diameter cylinders and 90 mm solid masonry blocks. Prior to bushfire exposure, the density and ambient compressive strength of the cement mixes were determined. Then, masonry blocks were exposed to bushfire flame zone conditions (BAL-FZ) for the first time and then for a second time (i.e., repeated exposure) and the effect of these exposures on the bushfire resistance and compressive strength (i.e., residual strength) of the masonry blocks was examined. The results obtained for the newly developed lightweight aggregate blocks were compared with those of the control block and two different commercially available solid blocks (i.e., Com 1 and Com 2). The control block recorded the highest temperature rises (69 and 84 °C), heating rates (1.26 and 1.47 °C/min) and compressive strength reductions (10.2 MPa) upon first-time and repeated bushfire exposure. The inclusion of lightweight aggregates in the masonry block mix lowered the temperature rises (between 17 and 61 °C) and heating rates (between 1.07 and 0.19 °C/min) on the ambient surface and also resulted in compressive strength reductions (between 3.2 and 9.0 MPa) during first-time and repeated bushfire exposure. Only the diatomite block (D60; block made with 60% diatomite aggregate) and commercial lightweight block (Com 2) remained within the interior temperature limits for bushfire shelters after both the first exposure and repeated exposure. However, only the D60 block satisfied the loadbearing strength requirement of 5 MPa even after repeated exposure. Therefore, considering the need to comply with the temperature limit on the interior surfaces of bushfire shelters during first-time and repeated exposure and to satisfy the loadbearing strength requirement of solid masonry units even after repeated bushfire exposure, the block made with 60% diatomite aggregate is recommended for use in the external walls of buildings in bushfire-prone areas. Full article

Under the collaborative framework of sustainable development and environmental pollution control in China, there is an urgent need to break the governance dilemma of traditional environmental regulations and explore innovative paths for sustainability. This paper empirically tests the direct impact, spatial spillover effects, and mechanisms of free trade zones (FTZs) in China in reducing water pollution. Using a spatial Durbin model (SDM) combined with the staggered difference-in-differences (STA-DID) method on a dataset of 266 Chinese cities encompassing eastern, central, and western regions with diverse economic and environmental baselines from 2003 to 2023, the study finds that FTZs significantly reduce local water pollution by 9.17 million tons of untreated sewage discharge (β = −916.6, p < 0.01), with a spatial spillover effect that decreases pollution in surrounding cities by 12.33 million tons (β = −1232.9, p < 0.01). Upgrading industrial structure, accelerating technological innovation, and strengthening government environmental governance constitute the core mediating channels. This study provides theoretical support for institutional innovation in environmental governance and empirical evidence to address the trade-off between economic growth and environmental protection in China, contributing to the understanding of how context-specific institutional innovations can advance regional sustainability, aligning with the United Nations Sustainable Development Goals (SDGs). Full article

Understanding diagenetic processes is fundamental to characterizing heterogeneous carbonate reservoirs, where variations in pore structures and mineralogy significantly influence reservoir quality and fluid flow behavior. This study presents an integrated diagenetic classification approach applied to the upper Dalan and Kangan formations in the Persian Gulf. Utilizing extensive core analyses, petrographic studies, scanning electron microscopy (SEM) imaging, and petrophysical data, six distinct diagenetic classes were identified based on the quantification of key processes such as dolomitization, dissolution, cementation, and compaction. The results reveal that dolomitization and dissolution enhance porosity and permeability, particularly in high-energy shoal facies, while cementation and compaction tend to reduce reservoir quality. A detailed petrographic examination and rock typing, including pore type classification and hydraulic flow unit analysis using flow zone indicator methods, allowed the subdivision of the reservoir into hydraulically meaningful units with consistent petrophysical characteristics. The application of the Stratigraphic Modified Lorenz Plot facilitated large-scale reservoir zonation, revealing the complex internal architecture and significant heterogeneity controlled by depositional environments and diagenetic overprints. This diagenetic classification framework improves predictive modeling of reservoir behavior and fluid distribution, supporting the optimization of exploitation strategies in heterogeneous carbonate systems. The approach demonstrated here offers a robust template for similar carbonate reservoirs worldwide, emphasizing the importance of integrating diagenetic quantification with multi-scale petrophysical and geological data to enhance reservoir characterization and management. Full article

In axial-flow combine harvesters, guide vanes direct crop material through the threshing and separation unit. The research object has the standard configuration of guide vane assembly; the six rear vanes are adjustable, while the two front vanes—located in the threshing zone—are fixed, which limits material flow control. In European conditions, where crop biomass is typically higher, improved control in the threshing area is essential to reduce losses and maintain grain quality. This study introduces a guide vane angle evaluation to combine performance and a modified guide vane system that enables all eight vanes to be adjusted simultaneously between 10–35°. Field tests were conducted using two identical combines (A and B) in the same winter wheat field, under identical operating conditions. Combine A was equipped with the modified system, while Combine B retained the original manufacturer configuration. Both machines operated at a rotor speed of 980 rpm and a concave clearance of 15 mm. Results showed that Combine A achieved higher throughput (23.78 kg s⁻¹), lower broken grain (0.18%), and lower fuel consumption (0.84 L t⁻¹) compared to Combine B (20.6 kg s⁻¹, 0.61%, 0.99 L t⁻¹, respectively); the separation and sieve losses were also reduced in Combine A. Analysis of the results demonstrated that full-range guide vane adjustability—including in the threshing zone—can improve crop flow, grain separation, and harvesting efficiency in high-yield conditions. Full article

The automotive industry is fully shifting towards autonomous connected vehicles. By advancing vehicles’ intelligence and connectivity, the industry has enabled innovative functions such as advanced driver assistance systems (ADAS) in the direction of driverless cars. Such functions are often referred to as cyber-physical features, since almost all of them require collecting data from the physical environment to make automotive operation decisions and properly actuate in the physical world. However, increased functionalities result in increased complexity, which causes serious security vulnerabilities that are typically a result of mushrooming functionality and hence complexity. In a world where we keep seeing traditional mechanical systems shifting to x-by-wire solutions, the number of connected sensors, processing systems, and communication buses inside the car exponentially increases, raising several safety and security concerns. Because there is no safety without security, car manufacturers start struggling in making lightweight sensor and processing systems while keeping the security aspects a major priority. This article surveys the current technological challenges in securing autonomous vehicles and contributes a cross-layer analysis bridging hardware security primitives, real-world side-channel threats, and redundancy-based fault tolerance in automotive electronic control units (ECUs). It combines architectural insights with an evaluation of commercial support for TrustZone, trusted platform modules (TPMs), and lockstep platforms, offering both academic and industry audiences a grounded perspective on gaps in current hardware capabilities. Finally, it outlines future directions and presents a forward-looking vision for securing sensors and processing systems in the path toward fully safe and connected autonomous vehicles. Full article

To address the challenges in predicting roof water hazards in weakly cemented strata of Northwest China, this study pioneers an integrated CNN-BiLSTM model for aquifer water abundance prediction. Focusing on the 1301E working face in the Yili No. 1 Coal Mine, we employed kriging interpolation to process sparse hydrological datasets (mean relative error: 8.7%), identifying five dominant controlling factors—aquifer burial depth, hydraulic conductivity, core recovery rate, sandstone–mudstone interbedded layer count, and sandstone equivalent thickness. The proposed bidirectional architecture synergizes CNN-based spatial feature extraction with BiLSTM-driven nonlinear temporal modeling, optimized via Bayesian algorithms to determine hyperparameters (32-channel convolutional kernels and 64-unit BiLSTM hidden layers). This framework achieves the comprehensive characterization of multifactorial synergistic effects. The experimental results demonstrate: (1) that the test set root mean square error (1.57 × 10⁻³) shows 65.3% and 85.9% reductions compared to the GA-BP and standalone CNN models, respectively; (2) that the coefficient of determination (R² = 0.9966) significantly outperforms the conventional fuzzy analytic hierarchy process (FAHP, error: 0.071 L/(s·m)) and BP-based neural networks; (3) that water abundance zoning reveals predominantly weak water-rich zones (q = 0.05–0.1 L/(s·m)), with 93.3% spatial consistency between predictions and pumping test data. Full article

To resolve the critical issues of severe deformation, structural failure, and maintenance difficulties in the advanced reuse zone of gob-side-entry retaining roadways under pillarless mining conditions in ultra-long fully mechanized top-coal caving isolated mining faces, this study proposes a surrounding rock control technology incorporating pressure relief through roof cutting. Taking the 3203 ultra-long isolated mining face at Nanyang Coal Industry as the engineering case, an integrated methodology combining laboratory experiments, theoretical analysis, numerical simulations, and industrial-scale field trials was implemented. The deformation and failure mechanism of flexible formwork walls in gob-side-entry retaining and the fundamental principles of pressure relief via roof cutting were systematically examined. The vertical stress variations in the advanced reuse zone of the retained roadway before and after roof cutting were investigated, with specific focus on the strata pressure behavior of roadways and face-end hydraulic supports on both the wide coal-pillar side and the pillarless side following roof cutting. The key findings are as follows: ① Blast-induced roof cutting reduces the cantilever beam length adjacent to the flexible formwork wall, thereby decreasing the load per unit area on the flexible concrete wall. This reduction consequently alleviates lateral abutment stress and loading in the floor heave-affected zone, achieving effective control of roadway surrounding rock stability. ② Compared with non-roof cutting, the plastic zone damage area of surrounding rock in the gob-side entry retained by flexible formwork concrete wall is significantly reduced after roof cutting, and the vertical stress on the flexible formwork wall is also significantly decreased. ③ Distinct differences exist in the distribution patterns and magnitudes of working resistance for face-end hydraulic supports between the wide coal-pillar side and the pillarless gob-side-entry retaining side after roof cutting. As the interval resistance increases, the average working resistance of hydraulic supports on the wide pillar side demonstrates uniform distribution, whereas the pillarless side exhibits a declining frequency trend in average working resistance, with an average reduction of 30% compared to non-cutting conditions. ④ After roof cutting, the surrounding rock deformation control effectiveness of the track gateway on the gob-side-entry retaining side is comparable to that of the haulage gateway on the 50 m wide coal-pillar side, ensuring safe mining of the working face. Full article

Rapid urbanization, climate variability, and land degradation are increasingly challenging traditional open-field farming systems. Soilless farming (SLF) has emerged as a complementary approach to enhance horticultural resilience in space-constrained and climate-stressed environments. This review critically evaluates the role of SLF within the broader framework of climate-smart agriculture (C-SA), with a particular focus on its applications in urban and peri-urban settings. Drawing on a systematic review of the existing literature, the study explores how SLF technologies contribute to efficient resource use, localized food production, and environmental sustainability. By decoupling crop cultivation from soil, SLF enables precise control over nutrient delivery and water use in enclosed environments, such as vertical farms, greenhouses, and container-based units. These systems offer notable advantages regarding water conservation, increased yield per unit area, and adaptability to non-arable or degraded land, making them particularly relevant for high-density cities, arid zones, and climate-sensitive regions. SLF systems are categorized into substrate-based (e.g., coco peat and rock wool) and water-based systems (e.g., hydroponics, aquaponics, and aeroponics), each with distinct design requirements, nutrient management strategies, and crop compatibility. Emerging technologies—including artificial intelligence, the Internet of Things, and automation—further enhance SLF system efficiency through real-time data monitoring and precision control. Despite these advancements, challenges remain. High setup costs, energy demands, and the need for technical expertise continue to limit large-scale adoption. While SLF is not a replacement for traditional agriculture, it offers a strategic supplement to bolster localized food systems and address climate-related risks in horticultural production. Urban horticulture is no longer a peripheral activity; it is becoming an integral element of sustainable urban development. SLF should be embedded within broader resilience strategies, tailored to specific socioeconomic and environmental contexts. Full article

To address the frequency regulation requirements of hybrid energy storage (HES) in renewable-dominated power grids, this paper proposes an asymmetric droop control strategy based on an improved backpropagation (BP) neural network. First, a simulation model of HES (comprising supercapacitors for the power support and batteries for the energy balance) participating in primary frequency regulation is established, with a stepwise frequency regulation dead zone designed to optimize multi-device coordination. Second, an enhanced Sigmoid activation function (with controllable parameters a, b, m, and n) is introduced to dynamically adjust the power regulation coefficients of energy storage units, achieving co-optimization of frequency stability and State of Charge (SOC). Simulation results demonstrate that under a step load disturbance (0.05 p.u.), the proposed strategy reduces the maximum frequency deviation by 79.47% compared to scenarios without energy storage (from 1.7587 × 10⁻³ to 0.0555 × 10⁻³) and outperforms fixed-droop strategies by 44.33%. During 6-min continuous random disturbances, the root mean square (RMS) of system frequency deviations decreases by 4.91% compared to conventional methods, while SOC fluctuations of supercapacitors and batteries are reduced by 49.28% and 45.49%, respectively. The parameterized asymmetric regulation mechanism significantly extends the lifespan of energy storage devices, offering a novel solution for real-time frequency control in high-renewable penetration grids. Full article

The summer cultivation of lettuce in greenhouses frequently encounters heat stress challenges. In hydroponic systems, cooling the nutrient solution to reduce root zone temperature is an effective strategy to alleviate heat stress. To address the issue of temperature control instability in hydroponic nutrient solutions under high-temperature conditions, this study developed a nutrient solution temperature control system based on an adaptive DBO-fuzzy PID controller. Firstly, the system integrates high-precision sensor networks and air-source heat pump units, forming the hardware foundation. Simultaneously, a fuzzy PID controller optimized by the Dung Beetle Optimizer (DBO) algorithm was designed for this system, enabling real-time adjustment of quantization and scaling factors in the fuzzy controller. Simulation results showed that the DBO-Fuzzy PID achieved a settling time of 35.23 s, overshoot of 2.18%, and steady-state error of 0.009 °C. The DBO-Fuzzy PID controller exhibited faster and more stable disturbance rejection compared to traditional PID and fuzzy PID control, demonstrating enhanced stability and robustness. System performance tests in the summer greenhouse demonstrated that with a setpoint of 22 °C, the DBO-Fuzzy PID optimized nutrient solution temperature control system maintained an average temperature of 21.98 °C, closer to the target value and exhibiting better adaptability to high-temperature environments compared to traditional PID control. Cultivation experiments confirmed the system’s effectiveness in mitigating heat stress and maintaining optimal nutrient solution temperature for lettuce growth. The results can provide a theoretical basis and practical reference for precise and stable temperature control in hydroponic nutrient solutions. Full article

With the high penetration of renewable energy, the imbalance between heat supply and demand is becoming increasingly severe. Installing additional heat storage bypass pipelines in the heating network can significantly enhance the heat storage capacity of the system, and regulating the supply and demand balance of heat stations can achieve a stable heat supply for users. This paper proposes a heat storage bypass configuration scheme and a dual-valve-coordinated control system. Based on the control valves’ ideal and operational flow characteristics, this paper delves into the minimum and maximum control impedance mechanisms in control valves, analyzing their impact on operational performance. Aiming at the fluctuation in the water supply temperature in the secondary pipe network (dead zone of 1%), the influence of control valve parameters on the dynamic response was systematically analyzed. The optimal parameter-matching scheme of the bypass control valve and the heat exchange control valve was finally determined through an optimization analysis. We verified its correctness based on the measured engineering data. This study improves the stability and operational efficiency of the supply and demand balance and decoupling control of the heating heat exchange unit, thereby establishing a critical technical foundation for advancing the high-efficiency integration of renewable energy sources within urban energy systems. Full article

The increasing integration of renewable energy sources has posed significant challenges to grid frequency stability. To maximize the advantages of energy storage in primary frequency regulation, this paper proposes a comprehensive control strategy for a hybrid energy storage system (HESS) based on supercapacitor battery. Firstly, considering the characteristics of the HESS and different control strategies, the battery responds to virtual droop control to reduce frequency deviation, while the supercapacitor responds to inertia control to suppress frequency drops and facilitate frequency recovery. Simultaneously, a reasonable dynamic dead zone is configured to prevent frequent actions of the battery and thermal unit while allowing flexible adjustments according to the load condition. Thirdly, an algebraic S-curve-based adaptive droop coefficient incorporating SOC is proposed, while the inertia coefficient additionally considers load type, enhancing adaptability. Furthermore, to better maintain the battery’s SOC, an improved adaptive recovery strategy within the battery dead zone is proposed, considering both SOC recovery requirements and system frequency deviation constraints. Finally, a simulation validation was conducted in MATLAB/Simulink. Compared to the conventional strategy, the proposed control strategy reduces the frequency drop rate by 17.43% under step disturbance. Under compound disturbances, the RMS of frequency deviation decreases by 13.34%, and the RMS of battery SOC decreases by 68.61%. The economic benefit of this strategy is 3.212 times that of the single energy storage scheme. The results indicate that the proposed strategy effectively alleviates sudden frequency disturbances, suppresses frequency fluctuations, and reduces battery output while maintaining the SOC of both the supercapacitor and the battery, thereby extending the battery lifespan and improving economic performance. Full article

Counties are fundamental units for ecological restoration, where scientifically delineated zoning is essential for resource allocation and governance. This study proposes a dual-dimensional, multi-source ecological zoning framework combining ecosystem service value (ESV) and Comprehensive Ecological Risk Index (CERI), with the CERI incorporating endogenous, exogenous, and regulatory ecological risk, providing a holistic representation of county-level ecological risk mechanisms. A Self-Organizing Map (SOM) neural network model clusters ESV and CERI, identifying spatial conflict zones and enabling high-resolution ecological management unit delineation. The results indicate the following: (1) The total ESV of Songzi City amounts to CNY 7.64 billion, showing spatial heterogeneity high-value clustering and low-value dispersion pattern, and water bodies and woodlands contributing 49.17% and 29.61%, respectively. (2) The spatial distribution of CERI is high in the central and eastern regions, and low in the west pattern, radiating from river systems under the combined effects of endogenous, exogenous, and regulatory risks. (3) Based on SOM clustering, four service clusters are identified and classified into ecological preventive conservation, vulnerability restoration, safeguard restoration, and improvement and utilization, shifting from broad-scale control to targeted ecological governance. This framework addresses the limitations of traditional single-dimensional risk assessments and provides a scientific basis for sustainable county-level ecological management. Full article

An alternative combustion technology to replace conventional start-up and flame stabilization using fuel oil or natural gas in pulverized coal-fired boilers has been investigated. In this study, a novel plasma burner design is proposed as a replacement for traditional auxiliary burners, operating by generating plasma through the ionization of air using microwave energy. The burner features an internal combustion system and a multi-stage ignition process to enhance flame stability, improve combustion efficiency, and enable more controlled pulverized coal burning within the plasma. Supported by a magnetron generating microwave energy at 915 MHz with a 75 kW output, the burner directly ignites approximately 22% of the coal–air mixture in the plasma zone, forming a stable flame that ensures complete combustion of the remaining coal. An experimental system was established, and tests were conducted by burning up to 3000 kg/h of pulverized coal in an industrial-scale setup at Unit-1 of the 22 MW_e Soma A Power Plant to optimize burner parameters. The specific microwave energy consumption was calculated as 0.055 kWh/kg of coal, demonstrating high energy efficiency and low operational cost. These results confirm that the microwave-assisted plasma burner is a technically viable, energy-efficient, and environmentally friendly alternative to conventional auxiliary burners. Full article