Search Results (190,512)

This study utilizes high-resolution sea surface temperature (SST) reanalysis data (0.25° × 0.25°) to investigate the relationship between SST anomalies in the South China Sea and ENSO events. The main findings are as follows: First, there is a delayed correlation between ENSO and SST anomalies in the South China Sea, with the correlation being stronger during El Niño years than during La Niña years. Second, the correlation with the peak values of the Oceanic Niño Index (ONI) is strongest for El Niño events with a 9-month lead, while for La Niña events, it is strongest with a 2-month lead. Seasonally, during El Niño events, the strongest correlations are observed in summer with a 3-month lead and in winter with a 1-month lag. For La Niña events, the strongest correlations are seen in summer with an 8-month lag and in winter with a 9-month lag. Finally, an analysis of atmospheric anomalies and shear kinetic energy anomalies relative to SST anomalies reveals a significant seasonal SST response, particularly during the summer of El Niño years and the winter of La Niña years. Overall, these results enhance our understanding of ENSO’s influence on the South China Sea and provide valuable insights for climate prediction and ecosystem protection in the region. Full article

Sustainability seeks to strike a balance between preserving the environment and meeting human needs without compromising future generations. In this context, and considering the effects of climate change on water availability, water reuse is emerging as an alternative to conventional water sources for various purposes, contributing to sustainability. Water reuse projects are, in general, not simple to implement due to different technical, environmental, social and economic aspects. In this paper, a support decision model for water reuse projects is presented, identifying relevant indicators and parameters. Based on a literature review, four indicators or dimensions (technical, social, environmental and economic) and twelve parameters (e.g., WWTP safety, transport complexity, existence of legislation, risk to health and environment, energy consumption, degree of acceptance and required investment and operation and maintenance costs) are proposed. The Fuzzy Analytic Hierarchy Process (FAHP) method is used as a component of the model to determine the weights of the indicators and parameters in order to allow the calculation of a reuse feasibility index (RFI). The developed model was applied to the city of Aquiraz, Ceará, Brazil, and the RFI found was 82%, which means that the water reuse project had very high viability. The results underwent a sensitivity analysis, which confirms the consistency of the conclusions. Full article

This study explores the physical, radiation shielding, optical, and photoluminescent properties of PbO₂-SiO₂-based glass systems. Traditional radiation shielding materials, like lead and concrete, face challenges due to toxicity and weight. Glass materials provide an alternative, offering transparency and efficiency. Four glass systems were analyzed: PbO₂-SiO₂ (PS), PbO₂-SiO₂-CeO₂ (PSC), PbO₂-SiO₂-Eu₂O₃ (PSE), and PbO₂-SiO₂-Yb₂O₃ (PSY). The results show that rare earth elements densify the glass network, thereby enhancing radiation attenuation properties, quantified through parameters like the linear attenuation coefficient (μ), the half-value layer (HVL), and the mean free path (MFP). The PSY system exhibited the best shielding properties, demonstrating its potential for use in gamma ray shielding. Samples PS0–PS3 revealed semiconducting behavior and may be considered a promising host matrix for solar cells and w-LED applications. Full article

The influence of Mg doping in α-Al₂O₃ crystals is investigated in this article by first-principles calculations and formation energies, density of states, and computed absorption spectra. Three models related to Mg²⁺ substituting for Al³⁺ doping structures were constructed, as well as spinel structure models with varying aluminum-magnesium ratios. The formation energy calculations confirmed the rationality of the Mg_AlV_O model, which means that Mg substitutional doping incorporating oxygen vacancies is most likely to form in crystals. The combined action of magnesium and oxygen vacancies introduced new defect energy levels in the bandgap. The calculated absorption spectra of the Mg_AlV_O and Mg-rich spinel structures exhibited various color centers. The experimental absorption spectra and thermoluminescence characteristics of α-Al₂O₃:Mg and alumina-magnesium (Al-Mg) spinel crystal samples were tested. The thermoluminescence peak of the Al-Mg spinel was significantly stronger than that of the α-Al₂O₃:Mg crystal. The consistency between the model-calculated absorption spectra and the experimental results confirmed the theoretical predictions. Based on the experimental and computational results, the influence of Mg²⁺ substitutional doping in α-Al₂O₃ and the impact of the locally Mg-rich spinel on the optical and radiation performance of α-Al₂O₃:Mg crystals are elucidated. Full article

New technologies and urban expansion have made it increasingly important for architects to incorporate movement into building facades, using a variety of artistic methods. This study explores the use of movable and movable-like solutions on urban elevations, ranging from visual effects to advanced technologies enabling physical movement. Case studies demonstrate different approaches to incorporating movement in building exteriors and their goals. This study considered how these solutions impact urban aesthetics, functionality, and energy efficiency. The research methods used include visual analysis, a literature review, and technological analysis of the kinetic systems used. The results show that movement at elevations can be achieved using various tools and can affect energy efficiency and building layout, in addition to having visual impacts. This study concluded that it is important to integrate new technologies into urban design and called for further research into the long-term impacts of changeable elevations on the urban environment. Full article

Within the realm of industrial energy conservation, the optimization of heat exchanger performance is paramount for the augmentation of energy utilization efficiency. This investigation employs computational fluid dynamics (CFD) simulations to elucidate the effects of an innovative DNA-Inspired Slotted Insert (DSI) on the convective heat transfer and pressure drop characteristics within heat exchange tubes. The study provides a thorough analysis of fully turbulent flow (Re = 6600−17,200), examining the effects of various DSI pitches, key lengths, and geometries. The findings reveal that the DSI instigates a three-dimensional spiral flow pattern, which is accompanied by an escalation in the Nusselt number (Nu) and friction factor (f) with increasing Reynolds numbers. An inverse relationship between Nu and both pitch and key length is observed; conversely, f exhibits a direct correlation with these parameters. The study identifies an optimal configuration characterized by a pitch of 10 mm and a key length of 1.5 mm, with square keys demonstrating superior heat transfer performance relative to other geometrical configurations. This research contributes significant design and application insights for double-helical inserts, which are pivotal for the enhancement of heat exchanger efficiency. Full article

The influences of MgO activity and its content on the mechanical properties, drying shrinkage compensation, pore structure, and microstructure of alkali-activated fly ash–slag materials were investigated. Active MgO effectively compensated for the alkali-activated materials’ (AAMs’) drying shrinkage. The drying shrinkage increased rapidly with the increase in curing age and stabilized after 28 d. Within a certain range, the material’s drying shrinkage was inversely proportional to the content of active MgO. The higher the activity of MgO, the lower the drying shrinkage of the AAMs under the same MgO content. The drying shrinkage values of the test groups with 9% R-MgO, M-MgO, and S-MgO at 90 d were 2444 με, 2306 με, and 2156 με, respectively. In the early stage of hydration, the addition of S-MgO reduced the compressive strength. As the content of M-MgO increased, the compressive strength first increased and then decreased, reaching a maximum of 72.28 MPa at an M-MgO content of 9%. The experimental group with 9% M-MgO exhibited higher compressive and flexural strengths than those with 9% S-MgO and R-MgO, demonstrating better mechanical properties. The results of this study provide an important theoretical basis and data support for the optimal application of MgO in AAMs. MgO expansion agents have great application potential in low-carbon buildings and durable materials. Further research on their adaptability in complex environments will promote their development for engineering and provide innovative support for green buildings. Full article

Existing studies have established reliable methods for estimating carbon emissions from food consumption, yet there remains a lack of quantitative analysis on the decarbonization effects of energy transition and resource recycling. This study integrates lifecycle analysis and scenario analysis, based on data from 2006 to 2020, to conduct an empirical investigation of four provincial capital cities (Zhengzhou, Xi’an, Jinan, and Taiyuan) in the lower and middle reaches of the Yellow River, exploring the potential for reducing carbon emissions from food consumption and examining the driving effects of energy transition and resource recycling. The results indicate the following: (1) Per capita carbon emissions from food consumption decreased after 2016. (2) Incineration for power generation has a significantly higher carbon reduction effect than landfilling. The proportion of carbon emissions from food waste disposal decreased from 20% to around 6%, with the decarbonization potential of recycling transformation being 8.8%, 8.3%, 11.5%, and 14.4% in Zhengzhou, Xi’an, Jinan, and Taiyuan, respectively. Our findings suggest that promoting the widespread adoption of new-energy vehicles, increasing the share of renewable energy in power generation, optimizing food recycling technologies, and reducing food waste are crucial for achieving future reductions in carbon emissions from urban food consumption. The proposed methodology for assessing carbon emissions and reduction potential in food consumption can also be applied to other regions with varying geographical, economic, and policy contexts. Full article

This research proposes an all-metal metamaterial-based absorber with a novel geometry capable of refractive index sensing in the terahertz (THz) range. The structure consists of four concentric diamond-shaped gold resonators on the top of a gold metal plate; the resonators increase in height by 2 µm moving from the outer to the inner resonators, making the design distinctive. This novel configuration has played a very significant role in achieving multiple ultra-narrow resonant absorption peaks that produce very high sensitivity when employed as a refractive index sensor. Numerical simulations demonstrate that it can achieve six significant ultra-narrow absorption peaks within the frequency range of 5 to 8 THz. The sensor has a maximum absorptivity of 99.98% at 6.97 THz. The proposed absorber also produces very high-quality factors at each resonance. The average sensitivity is 7.57/Refractive Index Unit (THz/RIU), which is significantly high when compared to the current state of the art. This high sensitivity is instrumental in detecting smaller traces of samples that have very correlated refractive indices, like several harmful gases. Hence, the proposed metamaterial-based sensor can be used as a potential gas detector at terahertz frequency. Furthermore, the structure proves to be polarization-insensitive and produces a stable absorption response when the angle of incidence is increased up to 60°. At terahertz wavelength, the proposed design can be used for any value of the aforementioned angles, targeting THz spectroscopy-based biomolecular fingerprint detection and energy harvesting applications. Full article

Sandy barrier systems are highly dynamic, with the most significant natural morphological changes to these systems occurring during high-energy storm conditions. These systems provide a range of economic and ecosystem benefits and protect inland areas from flooding and storm impacts, but the persistence of many coastal barriers is threatened by storms and sea-level rise (SLR). This study employed observations and modeling to examine recent and potential future influences of storms on a sandy coastal barrier system in Nauset Beach, MA. Drone-derived imagery and digital elevation models (DEMs) of the study area collected throughout the 2023–2024 winter revealed significant alongshore variability in the geomorphic response to storms. Severe, highly localized erosion (i.e., an erosional “hotspot”) occurred immediately south of the Nauset Bay spit as the result of a group of storms in December and January. Modeling results demonstrated that the location of the hotspot was largely controlled by the location of a break in a nearshore sandbar system, which induced larger waves and stronger currents that affected the foreshore, backshore and dune. Additionally, model simulations of the December and January storms assuming 0.3 m (1 ft) of SLR showed the system to be relatively resistant to major geomorphic changes in response to an isolated storm event, but more susceptible to significant overwash and breaching in response to consecutive storms. This research suggests that both very strong isolated storm events and sequential moderate storms pose an enhanced risk of major overwash, breaching, and possibly inlet formation today and into the future, raising concern for adjacent communities and resource managers. Full article

In order to reduce the impact of the performance degradation of a direct current (DC) distribution network system caused by the access of scaled electric vehicles (EVs), this paper proposes a collaborative optimization method for a DC distribution network based on scaled EVs charging and discharging and soft open points (SOPs) topology reconfiguration. Firstly, based on the normal charging of scaled EVs, the EV discharge power model and the discharge response model were established based on the V2G (vehicle-to-grid) characteristic. Based on the characteristics of SOPs regulating voltage and power distribution, the SOP model and its equivalent model of DC system are established to identify the collaborative optimization of scaled EVs charging and discharging and SOPs topology reconstruction. Secondly, the bi-level model that optimizes multi-objects, including distribution network system loss, total voltage deviation and customer benefits, is established. The upper and lower models use the multi-objective particle swarm optimization (MOPSO) algorithm and simulated annealing algorithm to jointly optimize the optimal EV discharge power and the optimal SOP access configuration simultaneously. Finally, the effectiveness of the proposed collaborative optimization method is verified by a modified IEEE 33-node DC system example. Full article

This paper aims to comprehensively explore the performance and influencing factors of the constructed wetland–microbial fuel cell (CW-MFC) system when treating brine with different concentrations. The main objective is to determine how different salinity levels affect the operation and treatment efficiency of the CW-MFC system. The research results show that Bruguiera gymnorrhiza exhibits strong salt tolerance and can be used as a wetland plant for the CW-MFC system. The closed-circuit CW-MFC system with planted plants has the best performance, with a chemical oxygen demand (COD) removal rate of 84.8%, a total nitrogen (TN) removal rate of 68.12%, and a chloride ion (Cl⁻) removal rate of 29.96%. The maximum power density is 64.79% higher than that of the system without planted plants. The power generation performance of the system first increases and then decreases with the increase in salinity, while the internal resistance keeps decreasing. When the salinity is 2%, the power generation effect is the best, with an average output voltage of 617.3 ± 25.7 mV and a power density of 45.83 mW/m². The removal rates of COD and TN are inhibited with the increase in salinity, while the removal rate of total phosphorus (TP) is not significantly affected. The microbial community grows well under salt stress, but its structure is different. When the salinity is 1%, the optimal distance between electrodes is 10 cm. Considering the pollutant removal performance, the optimal hydraulic retention time is 3 days, and considering the power generation performance, the optimal hydraulic retention time is 2 days. This research provides important value for improving the performance of the CW-MFC system in treating brine. Full article

Despite many studies, implementation of the additive manufacturing process in industrial and research practice is limited due to the numerous distortions affecting the obtained dependencies to a degree that is difficult to predict. No uniform methodology has been developed for the study of the impact of changes in the FFF parameters on the technological quality indicators. This paper presents a description of the original procedure for assessing technological quality using a reference component. The aim of the research was to analyze the impact of changes in the FFF additive manufacturing parameters on selected indicators of technological quality assessment of products. To compare the technological quality of the various models produced, measurements of surface roughness as well as dimensional and shape accuracy were carried out using stylus profilometry and coordinate measurement. The conducted tests showed that samples with a layer height of 0.12 mm have the most advantageous surface roughness parameters compared to the other layer heights of 0.16 mm and 0.20 mm tested. All the samples obtained were characterized by smaller dimensions than nominal, indicating the material shrinkage occurring during the FFF process. The study showed a negligible effect of material fill rate on surface roughness parameters as well as on the dimensions and shape accuracy. The obtained measurement results allow determining the most advantageous parameters of the FFF process depending on the adopted quality requirements. Full article

To address the issue of economic dispatch imbalance in virtual power plant (VPP) systems caused by the influence of operators and distribution networks, this study introduces an optimized economic dispatch method based on bi-level game theory. Firstly, a bi-level game model is formulated, which integrates the operational and environmental expenses of VPPs with the revenues of system operators. To avoid local optima during the search process, an enhanced reinforcement learning algorithm is developed to achieve rapid convergence and obtain the optimal solution. Finally, case analyses illustrate that the proposed method effectively accomplishes multi-objective optimization for various decision-making stakeholders, including VPP and system operators, while significantly reducing curtailment costs associated with the extensive integration of distributed renewable energy. Furthermore, the proposed algorithm achieves fast iteration and yields superior dispatch outcomes under the same modeling conditions. Full article

In line with environmental awareness movements and social concerns, the textile industry is prioritizing sustainability in its strategic planning, product decisions, and brand initiatives. The use of non-biodegradable materials, obtained from non-renewable sources, contributes heavily to environmental pollution throughout the textile production chain. As sustainable alternatives, considerable efforts are being made to incorporate biodegradable biopolymers derived from residual biomass, with reasonable production costs, to replace or reduce the use of synthetic petrochemical-based polymers. However, the commercial deployment of these biopolymers is dependent on high biomass availability and a cost-effective supply. Residual forest biomass, with lignocellulosic composition and seasonably available at low cost, constitutes an attractive renewable resource that might be used as raw material. Thus, this review aims at carrying out a comprehensive analysis of the existing literature on the use of residual forest biomass as a source of new biomaterials for the textile industry, identifying current gaps or problems. Three specific biopolymers are considered: lignin that is recovered from forest biomass, and the bacterial biopolymers poly(hydroxyalkanoates) (PHAs) and bacterial cellulose (BC), which can be produced from sugar-rich hydrolysates derived from the polysaccharide fractions of forest biomass. Lignin, PHA, and BC can find use in textile applications, for example, to develop fibers or technical textiles, thus replacing the currently used synthetic materials. This approach will considerably contribute to improving the sustainability of the textile industry by reducing the amount of non-biodegradable materials upon disposal of textiles, reducing their environmental impact. Moreover, the integration of residual forest biomass as renewable raw material to produce advanced biomaterials for the textile industry is consistent with the principles of the circular economy and the bioeconomy and offers potential for the development of innovative materials for this industry. Full article