Search Results (414)

In order to investigate the lateral working performance of large-scale steel casing-reinforced concrete pile composite members, this paper sets up large-scale steel casing-reinforced concrete pile composite members with different slenderness ratios λ, compressive axial force ratios N, and foundation strengths. It conducts quasi-static loading tests to investigate the effects of these factors on the hysteretic performance, bearing capacity, ductile performance, strength degradation, and stiffness degradation of the members. The results show that the hysteresis curves of the members all have a typical inverse S-shape, which is affected by slip and has a poor degree of fullness. The members with larger slenderness ratios exhibit better ductility performance, deformation performance, and energy dissipation performance, but their poorer bearing capacity and effect on stiffness degradation are limited. While members with smaller slenderness ratios exhibit better bearing capacity, their ductile performance is poor. As the compressive axial force ratio increases, the lateral bearing capacity and ductility of the members slightly improve. However, the bearing capacity rapidly decreases when the compressive axial force ratio reaches a critical value. As the strength of the foundation increased, the lateral bearing capacity of the structures continued to improve, but its improvement effect began to decay after reaching a certain value. This paper investigates the lateral working properties of large-scale steel casing-reinforced concrete pile composite members designed for overhead vertical wharves that are subjected to significant water level differences in inland rivers, aiming to provide a reference for their application in practical engineering. Full article

Transition metal selenides are considered one of the most promising materials for sodium-ion battery anodes due to their excellent theoretical capacity. However, it remains challenging to suppress the volume variation and the resulted capacity decay during the charge–discharge process. Herein, hollow-structured CoNiSe₂ dual transition metal selenides wrapped in a carbon shell (HS-Co_xNi_ySe₂@C) were deliberately designed and prepared through sequential coating of polyacrylonitrile (PAN), ion exchange of ZIF-67 with Ni²⁺ metal ions, and carbonization/selenization. The hollow structure was evidenced by transmission electron microscopy, and the crystalline structure was confirmed by X-ray diffraction. The ample internal space of HS-Co_xNi_ySe₂@C effectively accommodated volume expansion during the charge and discharge processes, and the large surface area enabled sufficient contact between the electrode and electrolyte and shortened the diffusion path of sodium ions for a feasible electrochemical reaction. The surface area and ionic conductivity of HS-Co_xNi_ySe₂@C were strongly dependent on the ratio of Co to Ni. The synergistic effect between Co and Ni enhanced the conductivity and electron mobility of HS-Co_xNi_ySe₂@C, thereby improving charge transfer efficiency. By taking into account the structural advantages and rational metal selenide ratios, significant improvements can be achieved in the cycling performance, rate performance, and overall electrochemical stability of sodium-ion batteries. The optimized HS-Co_xNi_ySe₂@C demonstrated excellent performance, and the reversible capacity remained at 334 mAh g⁻¹ after 1000 cycles at a high current of 5.0 A g⁻¹. Full article

Despite their high specific capacity, magnetron-sputtered Si/Al thin films face rapid capacity decay due to stress-induced cracking, delamination, and detrimental electrolyte reactions. This study introduces a carbon-coated composite anode that overcomes these limitations, delivering superior reversible capacity, exceptional rate capability, and stable cycling performance. An electrochemical evaluation reveals that the CF-Si/Al@C-500-1h composite exhibits marked enhancements in capacity retention (43.5% after 100 cycles at 0.6 A·g⁻¹) and rate capability, maintaining 579.1 mAh·g⁻¹ at 3 A·g⁻¹ (1 C). The carbon layer enhances electrical conductivity, buffers volume expansion during lithiation/delithiation, and suppresses silicon aggregation and electrolyte side reactions. Coupled with an aluminum framework, this architecture ensures robust structural integrity and efficient lithium-ion transport. These advancements position CF-Si/Al@C-500-1h as a promising anode material for next-generation lithium-ion batteries, while insights into scalable fabrication and carbon integration strategies pave the way for practical applications. Full article

Using chaos theory, maximum entropies are calculated for 108 time series, each consisting of 28,463 hourly data of urban meteorology and pollutants. The series were measured with standardized and certified instruments (EPA) in six locations at different heights and in three periods (2010/2013, 2017/2020, and 2019/2022) in a basin geomorphology. Each urban meteorology series corresponds to relative humidity (RH), temperature (T), and wind speed magnitude (WS), and each pollutant series corresponds to 10 µm particulate matter (PM₁₀), 2.5 µm particulate matter (PM_2.5), and carbon monoxide (CO). These pollutants are in the top three places of presence in the studied geomorphology and in incidence in population diseases. From the calculated entropies, a quotient is constructed between the entropies of each of the first two urban meteorology variables (RH and T) and the sum of maximum entropies of the time series of anthropogenic pollutants, demonstrating the gradual decay in time of the quotient that is dominated by the maximum entropies of the pollutants. The latter leads to a more excited and warm boundary layer, due to thermal transfers, which makes it more unpredictable, increasing its capacity to contain water. It is verified that the diffusion is anomalous with alpha < 1 and that the contamination has a high probability, using a heavy-tailed probability function, of causing extreme events by influencing urban meteorology. Full article

The cement–soil pipe pile is a novel blend of cement and soil, designed to enhance load-bearing capabilities while cutting down on the need for cement. Its tubular construction is key to its strength. To delve into how the pile’s cross-sectional size affects its load-bearing properties, we took into account the soil–cement’s strain-softening behavior. Laboratory tests examined the load-bearing properties of piles. We created an exponential decay Mohr–Coulomb model in ABAQUS for further development, performed field tests, and built a numerical model incorporating wall thickness, pile diameter, and length. The unit volume ultimate bearing capacity was used to evaluate pile performance, with a focus on a 600 mm diameter pile. The results show that wall thickness minimally affects load-bearing capacity, needing to be at least a quarter of the diameter. Larger diameters increase the ultimate bearing capacity, but the capacity per unit volume declines. The 600 mm diameter pile boasts the highest unit volume ultimate bearing capacity. The pile’s effective length is roughly 10 m. Beyond this, extending the pile length increases the single pile’s ultimate bearing capacity by less than 5%, but the unit volume capacity starts to dwindle. Full article

Active packaging using an edible coating could be an essential and sustainable alternative solution to preserve the properties of fruits and to prevent food loss and food waste. Fruits generate significant food wastes and losses. Reducing food waste is a global priority. For this research, nature-based solutions (NBSs) were applied, using micro-sized chitosan (CsMPs) and selenium microparticles (SeMPs), which are green-synthesized from black tea leaf extracts, and thyme essential oil. In this study, the effects of the new generation active food preservative coating agents formed from combinations of micro-sized chitosan (CsMPs) and selenium (SeMPs), and thyme essential oil (Oil) on the quality of “0900 Ziraat” sweet cherry fruits after harvest were investigated. After the fruits were coated with edible colloid solution, they were stored at 4 °C and 21 °C for 20 days, and quality parameter analyses were performed on days 0, 5, 10, 15, and 20. As a result of this study, it was determined that the application of CsMPs + SeMPs and the subsequent application of CsMPs + SeMPs + Oil from colloid solution coatings reduced weight loss, respiration, and decay rates. Also, it was determined that these applications were the most effective in preserving color values (L*, chroma, and hue), fruit firmness, total soluble solid (TSS) amount, acidity content and total phenolics, anthocyanin, and antioxidant capacity. These results show that CsMPs + SeMPs and CsMPs + SeMPs + Oil applications can be used as edible coatings to preserve the quality of sweet cherry fruits and extend their shelf life after harvest. This study’s results will contribute to obtaining micro-sized composite coating agents/agents produced with new technology to extend the shelf life. Full article

Niobium pentoxide (Nb₂O₅) is a promising anode candidate for lithium-ion batteries due to its high theoretical capacity, excellent rate capability, and safe working potential. However, its inherent low conductivity limits its practical application in fast-charging scenarios. In this work, we develop an ultrathin carbon-coated two-dimensional T-Nb₂O₅ nanosheet composite (T-Nb₂O₅@UTC) through a facile solvothermal reaction and subsequent CVD acetylene decomposition. This unique design integrates a two-dimensional nanosheet structure with an ultrathin carbon layer, significantly enhancing electronic conductivity, reducing ion diffusion pathways, and preserving structural integrity during cycling. The T-Nb₂O₅@UTC electrode demonstrates an impressive specific capacity of 214.7 mAh g⁻¹ at a current density of 0.1 A g⁻¹, maintaining 117.9 mAh g⁻¹ at 5 A g⁻¹, much outperforming the bare T-Nb₂O₅ (179.6 mAh g⁻¹ at 0.1 A g⁻¹ and 62.9 mAh g⁻¹ at 5 A g⁻¹). It exhibits outstanding cyclic stability, retaining a capacity of 87.9% after 200 cycles at 0.1 A g⁻¹ and 83.7% after 1000 cycles at 1 A g⁻¹. In a full-cell configuration, the assembled T-Nb₂O₅@UTC||LiFePO₄ battery exhibits a desirable specific capacity of 186.2 mAh g⁻¹ at 0.1 A g⁻¹ and only a 1.5% capacity decay after 120 cycles. This work underscores a nanostructure engineering strategy for enhancing the electrochemical performance of Nb₂O₅-based anodes toward high-energy-density and fast-charging applications. Full article

Marine power systems, including generators and transformers, experience voltage stress at various frequencies. Once the stress exceeds the bearing capacity of the electrical system, it results in insulation breakdown or failure. Therefore, extensive testing is required to ensure that marine electrical insulation systems are reliable. In accordance with International Electrotechnical Commission (IEC) standards, conventional tests at commercial frequencies require over 5000 h, making them time-consuming, inefficient, and practically infeasible. This study explores frequency-based accelerated life testing to reduce the duration of testing. Insulation systems made of mica-based corona-resistant materials and epoxy resin were tested at 60, 300, 600, and 900 Hz using a variable-frequency high-voltage tester. The results show that the time to failure decreases as the frequency increases (from 381.83 h at 60 Hz to 22.33 h at 900 Hz, a 94% reduction). Power and exponential decay models effectively describe this relationship. The power model provides a better overall fit, and the exponential decay model improves the accuracy at higher frequencies. This study confirms that higher frequencies accelerate insulation degradation, shortening test times considerably. Frequency-based accelerated testing can enhance insulation system evaluation and optimize international testing standards. Full article

In this paper, the natural waste pinecone as a carbon precursor for the generation of satisfactory sulfur host materials in lithium–sulfur batteries was realized by introducing molybdenum carbide nanoparticles into the derived carbon structure. The conductive pinecone-derived carbon doped with N, O reveals an expansive specific surface area, facilitating the accommodation of a higher sulfur load. Moreover, the integration of Mo₂C nanoparticles also significantly enhances its chemical affinity and catalytic capacity for polysulfides (LiPSs) to alleviate the shuttle effect and accelerate sulfur redox conversion. As a result, the WPC-Mo₂C/S electrode displays excellent electrochemical performance, including a low capacity decay rate of 0.074% per cycle during 600 cycles at 1 C and an outstanding rate capacity (631.2 mAh g⁻¹ at 3 C). Moreover, with a high sulfur loading of 5.5 mg cm⁻², the WPC-Mo₂C/S electrode shows a high area capacity of 5.1 mAh cm⁻² after 60 cycles at 0.2 C. Full article

A two-dimensional longitudinal profile model was used to evaluate groundwater flow along a 48 km flowline in the Southeastern Hueco Aquifer, extending from the Diablo Plateau in Texas to the Sierra de San Ignacio in Chihuahua, Mexico. The model, incorporating geologically distributed permeability values, closely matched the predevelopment potentiometric surface. Predicted recharge rates and travel times aligned with published estimates and environmental isotopes, suggesting potential transboundary groundwater movement. The model estimated recharge rates needed to reach flow capacity, or the maximum volume a system can transmit, typically saturating the water table. Current moisture levels are insufficient, but flow capacity may have been reached during late Pleistocene pluvial periods. Required recharge rates were 297% higher than initial calibration in the U.S. and 1080% higher in Mexico, with only U.S. estimates appearing plausible for the Pleistocene–Holocene transition. These findings are relevant to regional waste disposal considerations because water tables near land surface present a risk to groundwater resources. A transient simulation modeled hydraulic head decay due to recharge abatement linked to climate change over 14,000 years. It simulated a decrease from a “flow capacity” recharge rate of 10.4 mm/year to 3.5 mm/year today. The modeling simulations ended with the hydraulic head remaining only 20 m above current levels, suggesting a minimal-to-negligible fossil hydraulic gradient in the low-permeability flow system. Full article

Wave attenuation by natural coastal features is recognised as a soft engineering approach to shoreline protection from storm surges and destructive waves. The effectiveness of wave energy dissipation is determined, in part, by vegetation structure, extent, and distribution. Mangroves line ca. 15% of the world’s coastlines, primarily in tropical and subtropical regions but also extending into temperate climates, where mangroves are shorter and multi-stemmed. Using wave loggers deployed across mangrove and non-mangrove shorelines, we studied the wave attenuating capacity and the drag coefficient (C_D) of temperate Avicennia marina mangrove forests of varying structure in Western Port, Australia. The structure of the vegetation obstructing the flow path was represented along each transect in a three-dimensional point cloud derived from overlapping uncrewed aerial vehicle (UAV) images and structure-from-motion (SfM) algorithms. The wave attenuation coefficient (b) calculated from a fitted exponential decay model at the vegetated sites was on average 0.011 m⁻¹ relative to only 0.009 m⁻¹ at the unvegetated site. We calculated a C_D for this forest type that ranged between 2.7 and 4.9, which is within the range of other pencil-rooted species such as Sonneratia sp. but significantly lower than prop-rooted species such as Rhizophora spp. Wave attenuation efficiency significantly decreased with increasing water depth, highlighting the dominance of near-bed friction on attenuation in this forest type. The UAV-derived point cloud did not describe the vegetation (especially near-bed) in sufficient detail to accurately depict the obstacles. We found that a temperate mangrove greenbelt of just 100 m can decrease incoming wave heights by close to 70%, indicating that, similarly to tropical and subtropical forests, temperate mangroves significantly attenuate incoming wave energy under normal sea conditions. Full article

As the forefront of inland extension on the Indian plate, the northeastern Tibetan Plateau, marked by low strain rates and high stress levels, is one of the regions with the highest seismic risk. Analyzing seismicity through statistical methods holds significant scientific value for understanding tectonic conditions and assessing earthquake risk. However, seismic monitoring capacity in this region remains limited, and earthquake frequency is low, complicating efforts to improve earthquake catalogs through enhanced identification and localization techniques. Bi-scale empirical probability integral transformation (BEPIT), a statistical method, can address these data gaps by supplementing missing events shortly after moderate to large earthquakes, resulting in a more reliable statistical data set. In this study, we analyzed six earthquake sequences with magnitudes of M_S ≥ 6.0 that occurred in northeastern Tibet since 2009, following the upgrade of the regional seismic network. Using BEPIT, we supplemented short-term missing aftershocks in these sequences, creating a more complete earthquake catalog. ETAS model parameters and b values for these sequences were then estimated using maximum likelihood methods to analyze parameter variability across sequences. The findings indicate that the b value is low, reflecting relatively high regional stress. The background seismicity rate is very low, with most mainshocks in these sequences being background events rather than foreshock-driven events. The p-parameter of the ETAS model is high, indicating that aftershocks decay relatively quickly, while the α-parameter is also elevated, suggesting that aftershocks are predominantly induced by the mainshock. These conditions suggest that earthquake prediction in this region is challenging through seismicity analysis alone, and alternative approaches integrating non-seismic data, such as electromagnetic and fluid monitoring, may offer more viable solutions. This study provides valuable insights into earthquake forecasting in the northeastern Tibetan Plateau. Full article

Integrated Li- and Mn-rich layered cathodes yLi₂MnO₃∙(1-y)LiMO₂ (M = Mn, Co, and Ni) have shown their ability to deliver specific capacities close to 300 mAh g⁻¹, but their significant drawbacks are capacity fading and voltage decay during cycling. In this study, new stoichiometric high-voltage Li-rich oxides with y = 0.0, 0.3, and 0.5 are synthesized in identical conditions using a sol–gel method. These compositions were analyzed to determine their optimal configuration and to understand their extraordinary behavior. Their nanostructural properties were investigated using XRD and Raman spectroscopy, while the morphology and grain-size distribution of the samples were characterized by BET, SEM and HRTEM analyses. The electrochemical performances of the integrated Li- and Mn-rich compounds were evaluated through galvanostatic cycling and electrochemical impedance spectroscopy. The best cathode material 0.5Li₂MnO₃∙0.5LiNi_1/3Co_1/3Mn_1/3O₂ had a capacity retention of 83.6% after 100 cycles in the potential range 2.0–4.8 V vs. Li⁺/Li. Full article

The Castle of Lanjarón is a 16th century stronghold located in Andalucía, Spain. After losing its military function, the castle was abandoned, leading to significant decay. Designated a national heritage site in 1985, recent efforts have sought to preserve its historical and cultural value. This study outlines an inspection and diagnosis campaign carried out on the castle. Non-destructive tests (NDTs) were employed to characterize the properties of the masonry, using both mechanical and wave-based methods. Dynamic identification was performed to determine dynamic and modal properties of the structure, which were used to develop and calibrate a three-dimensional (3D) finite element model (FEM) of the west wall, based on homogenized masonry material. Limit analysis and non-linear static (pushover) analysis under various boundary conditions were conducted to determine the maximum relative load factor in the out-of-plane direction. The results were compared to the expected peak ground acceleration (PGA) of the area, showing that the maximum load capacity of the wall exceeds local seismic demands with a safety factor of 1.39. The study highlights the efficacy of pairing a homogenized macro-modeling approach with wave-based and dynamic identification methods, particularly for resource efficiency. Finally, recommendations for future conservation efforts have been provided. Full article

Red grapes often suffer from postharvest diseases like blue mold and black mold caused by Penicillium expansum and Aspergillus niger. Biological control using beneficial yeasts and bacteria is an effective method to manage these diseases. Rhodotorula sp. and Bacillus sp. are effective microorganisms for the control of postharvest diseases of red grapes. This study combined two yeast strains (Rhodotorula graminis and Rhodotorula babjevae) and two bacterial strains (Bacillus licheniformis and Bacillus velezensis) to investigate their biological control effects on major postharvest diseases of red grapes and explore the underlying physiological mechanisms. Research showed that compound microorganism W3 outperformed the others; it reduced spore germination and germ tube growth of P. expansum and A. niger, while its volatiles further inhibited pathogen growth. Additionally, the treatment enhanced the antioxidant capacity of grapes and increased resistance to pathogens by boosting peroxidase activities, superoxide dismutase, catalase and ascorbate peroxidase, phenylalanine ammonolyase, and polyphenol oxidase. Furthermore, the combined treatment increased the activity and accumulation of antifungal compounds such as total phenols and flavonoids, thereby improving disease resistance and reducing decay. Therefore, composite microorganisms combining various antagonistic strains may offer a viable substitute for tackling postharvest diseases in red grapes. Full article