Search Results (3,321)

This study investigates the tribological behavior of selective laser-sintered (SLS) sliding bearings under dry-sliding operating conditions. These polyamide-12 bearings reinforced with glass beads (PA 3200 GF) were tested against a stainless-steel sleeve in three different pressure–velocity (PV) regimes that represent real operating conditions. The coefficient of friction (COF) and contact temperatures were monitored throughout the experiment, while the specific wear rate was quantified based on mass loss measurements. The evolution of surface topography was analyzed using roughness parameters of the Abbott-Firestone family. Scanning electron microscopy (SEM) analysis was performed to identify the dominant wear mechanism. The results show a pronounced running-in phase, after which a stable thermomechanical equilibrium occurs in all regimes. Heavy-loaded regimes increase temperature but accelerate surface adaptation and lower stable coefficients of friction. Lower load regimes have the lowest thermal load but higher friction due to lower real contact. The medium PV regime has a low COF and moderate temperature rise, while peak and core roughness metrics increase more significantly. These results provide an experimentally based insight into the influence of the load regime on the tribological behavior and topography of the SLS-made polymer sliding bearings, thus contributing to a deeper understanding of their operation in real dry-sliding conditions. Full article

Lake Kotokel is one of the largest lakes along the eastern shore of Lake Baikal. Increasing anthropogenic pressure combined with climate variability led to a sharp decline in its ecological condition, culminating in an outbreak of Gaff disease in 2009. Moreover, Lake Kotokel may serve as a source of pollutants to Lake Baikal due to its hydrological connection via a system of rivers. In light of these factors, ongoing research seeks to identify the drivers of ecological degradation in the lake ecosystem and provide a comprehensive assessment of its current environmental status and potential adverse processes. In this study, we report, for the first time, the occurrence of microplastic particles in the surface water and sediments of Lake Kotokel. Mean microplastic concentrations were 0.59 ± 0.25 items/m³ in water and 280 ± 162 items/kg dry weight in sediments, with corresponding average microplastic masses of 2.6 ± 1.4 μg/m³ in water and 1.33 ± 1.21 mg/kg dry weight in sediments. In surface waters, microplastic were predominantly 1–3 mm in size, whereas sediments were dominated by 0.1–1 mm particles. Fibers were the most abundant morphological form, comprising 79.5% and 82.8% of particles in water and sediments, respectively. Five polymer types were identified, with polyethylene terephthalate being the most prevalent. Based on particle abundance and polymer composition, the ecological risk of microplastic in Lake Kotokel was assessed as low to moderate. Full article

Plant functional traits are key to understanding species performance, community assembly and ecosystem processes. Fruit and seed traits play an important role in early life-cycle processes by influencing seed dispersal, germination, and establishment, ultimately shaping plant regeneration and ecosystem dynamics. While global initiatives such as TRY and Seed Information Database (SID) have assembled extensive trait data, coverage of reproductive traits remains limited, and high-quality images of diaspores are particularly scarce, particularly in subtropical Asia. To address this need, we created an open-source, comprehensive database of fruit and seed traits, accompanied by diaspore images against a high-contrast background. This dataset documents 684 species in 128 families recorded in Hong Kong and provides standardised measurements of morphological attributes (e.g., length, mass, number of seeds per fruit) and dispersal characteristics (e.g., presence of appendages). Our measurements were validated against previously published records of common species in Hong Kong, showing strong consistency with R² = 0.80 (p < 0.001) for fruit dry mass and R² = 0.91 (p < 0.001) for seed dry mass, respectively. This database provides a valuable resource for trait-based ecology, forest dynamics and conservation biology. Additionally, it supports applications in ecological restoration, habitat management, and predicting plant responses to environmental change. This initiative enhances our understanding of trait-based ecology by complementing global initiatives such as TRY and SID and improving the representation of reproductive traits from subtropical Asia, a region that is underrepresented in existing global databases. Full article

The Changjiang estuary–Hangzhou Bay region is a critical zone of land–sea interaction, where Total Suspended Matter (TSM) dynamics significantly influence coastal ecology and engineering. While previous studies have examined individual factors affecting TSM variability, the synergistic effects of “tide–monsoon–current” interactions and the actual pathways of turbid plume transport remain poorly understood. Using GOCI satellite data, in situ buoy measurements, and voyage data from 2020, this study applied Data Interpolating Empirical Orthogonal Functions (DINEOFs) and comprehensive spatio-temporal analysis to reconstruct continuous high-resolution TSM fields and elucidate multi-factor controls on TSM dynamics. Based on this high-resolution dataset of TSM, we found that, during the dry season, elevated TSM concentrations are primarily driven by wind–tide resuspension and transport under the comprehensive forcing of the Jiangsu Alongshore Current (JAC), the Yellow Sea Warm Current (YSWC), and wind–tide-induced flows. Contrary to the conventional understanding, the Jiangsu-origin surface TSM can transport to the outer sea without supplementing the TSM in the Turbidity Maximum Zone (TMZ). The YSWC in autumn can cause either low C_TSM gradients or high gradients nearshore depending on whether it is carrying Korean coastal turbid water or not. During the wet season, stratification induced by the Changjiang freshwater discharge suppresses wind–tide resuspension, reducing TSM concentrations in the TMZ and the Qidong water. However, the Changjiang freshwater combined with the Taiwan Warm Current (TWC) dilutes surface TSM in Hangzhou Bay, where the two water masses meet on the 10 m isobath. These insights into factor interactions and TSM plume pathways provide a scientific basis for improved environmental monitoring and coastal management. Full article

Hydrodynamic cavitation (HC) is a green and readily scalable platform for the recovery and upgrading of bioactives from agri-food and forestry byproducts. This expert-led narrative review examines HC processing of citrus and pomegranate peels, softwoods, and plant protein systems, emphasizing process performance, ingredient functionality, and realistic routes to market, and contrasts HC with other green extraction technologies. Pilot-scale evidence repeatedly supports water-only operation with high solids and short residence times; in most practical deployments, energy demand is dominated by downstream water removal rather than the extraction step itself, which favors low water-to-biomass ratios. A distinctive outcome of HC is the spontaneous formation of stable pectin–flavonoid–terpene phytocomplexes with improved apparent solubility and bioaccessibility, and early studies indicate that HC may also facilitate protein–polyphenol complexation while lowering anti-nutritional factors. Two translational pathways appear near term: (i) blending HC-derived dry extracts with commercial dry protein isolates to deliver measurable functional benefits at low inclusion levels and (ii) HC-based extraction of plant proteins to obtain digestion-friendly isolates and conjugate-ready ingredients. Priority gaps include harmonized reporting of specific energy consumption and operating metrics, explicit solvent/byproduct mass balances, matched-scale benchmarking against subcritical water extraction and pulsed electric field, and evidence from continuous multi-ton operation. Overall, HC is a strong candidate unit operation for circular biorefineries, provided that energy accounting, quality retention, and regulatory documentation are handled rigorously. Full article

Phosphate-solubilizing rhizobacteria associated with the Solanum tuberosum L. cultivar ‘Superchola’ were isolated and characterized to improve our understanding of plant growth promotion in agricultural systems. Bacteria were isolated by serial dilutions, and the morphology of the colonies was characterized on nutrient agar culture medium. In addition, morphological identification was achieved by Gram staining. The ability to solubilize phosphate was assessed in Pikovskaya agar culture medium, while molecular identification involved the amplification of the partial 16S rRNA gene using the polymerase chain reaction. In the Píllaro canton, the highest number of colony-forming units per gram of soil was recorded at 9.72 × 10⁹. Among the isolated strains, 62% exhibited circular morphology, 92% had a smooth texture, and 85% displayed entire margins. Notably, 83% of the isolates were Gram-negative, with 50% exhibiting a bacillary form. The most effective phosphate solubilizers were from the Mocha canton, particularly the isolate CC-FCAGP-BSF6, which showed superior solubilization capacity. Molecular identification revealed bacterial isolates from four genera, i.e., Bacillus, Pseudomonas, Lysinibacillus, and Paenibacillus. These strains exhibited significant phosphate solubilization in vitro and resulted in increased leaf area (0.21–0.49, p = 0.038), fresh mass (0.46–0.87, p = 0.014), dry mass (0.092–0.096, p = 0.047), and leaf area index (0.14–0.33, p = 0.026) in the S. tuberosum cultivar ‘Superchola’ in vitro plants. This study identifies bacterial species associated with the rhizosphere of S. tuberosum in Ecuador and highlights their potential for promoting plant growth and solubilizing phosphates. Full article

This study examines the performance of a proton exchange membrane fuel cell operated in electrochemical hydrogen compression (EHC) mode, focusing on the effects of temperature, relative humidity (RH), and pressure on water management and efficiency. Two humidification strategies were investigated: (i) a dry cathode with humidified anode hydrogen and (ii) a flooded cathode with controlled anode humidification. Experiments were conducted at different temperatures (from 35 to 70 °C), RH levels (from 0 to 100%), and compression ratios of 1 and 2, using polarization curves, electrochemical impedance spectroscopy, and linear sweep voltammetry (LSV). In the dry cathode configuration, optimal performance occurred at 70 °C with fully humidified anode gas, achieving current densities above 2 A cm⁻² at voltages below 0.3 V. Partial humidification caused instability due to membrane dehydration. In the flooded cathode, high cathode pressure increased mass transport resistance, while excessive inlet humidification promoted flooding and consequently reduced the efficiency. LSV results highlighted the trade-off between proton conductivity and hydrogen back diffusion, particularly for thin membranes used in this study. The findings demonstrate that precise water balance is essential for stable and efficient EHC operation and provide guidelines for optimizing compression performance, supporting the development of high-efficiency and low-maintenance hydrogen compression systems for stationary and mobile applications. Full article

To address the energy and environmental challenges, this study targets the need for ultra-low energy buildings in China’s hot summer-cold winter region (HSCW) by developing high-performance alkali-activated foam concrete (AAFC) insulation material. Initially, a target performance indicator system was established. Subsequently, a mix proportion design method based on the volume method was proposed, and preliminary mix proportions were designed and tested to achieve the target performance. Accordingly, eight factors, including alkali equivalent and SiO₂ aerogel content, were selected for further optimization. A systematic optimization of performance was then conducted using an L₃₂(4⁸) orthogonal experimental design. Range analysis and analysis of variance indicated that foam content significantly affected all target properties. The water-to-binder ratio notably influenced mechanical performance and dry density. Alkali equivalent and activator modulus directly regulated the reaction process. Notably, the incorporation of 2.5 wt% SiO₂ aerogel reduced the thermal conductivity to 0.1107 W/(m·K), highlighting its significant role in improving thermal insulation and effectively resolving the common trade-off between insulation and mechanical properties in FC. Furthermore, the waterproofing agent played a critical role in reducing water absorption and enhancing frost resistance. Finally, the optimal mix proportion was determined through matrix analysis, with all material properties meeting the expected targets. Test results confirmed that the optimized FC achieved a dry density of 576.34 kg/m³, compressive and flexural strengths of 5.83 MPa and 1.41 MPa, respectively, a drying shrinkage rate of only 0.614 mm/m, a mass water absorption of 3.87%, and strength and mass loss rates below 10.5% and 1.8% after freeze–thaw cycles. Therefore, this material presents a novel solution for the envelope structures of low-energy buildings. Full article

Aerobically produced methane (CH₄) from plants is influenced by several environmental factors, but wind velocity has yet to be investigated for its potential role in plant-derived CH₄ emissions. We tested three wind velocities (0, 6, and 12 km h⁻¹) on a wind-susceptible, Raphanus sativus (radish), and a wind-tolerant, Brassica oleracea var. sabellica (kale) plant species to investigate the effects of wind on plant-derived CH₄, and to compare how varying tolerances to wind affect CH₄ emissions. We found that wind exposure resulted in a decrease in leaf surface area, root and total dry mass, and an increase in leaf water potential for radish plants, while kale plants were affected minimally by wind. Radish plants emitted more CH₄ than kale plants, although the effect of wind velocity on CH₄ emissions and several of the measured traits was insignificant. Our study revealed that short-term exposure to lower wind velocities is generally insufficient to induce significant changes in plant growth and functioning. However, we showed that radish plants were more stressed by exposure to wind compared to kale plants, as indicated by lower plant growth and higher CH₄ emissions. Full article

Background: Nebulized polymyxin B (PMB) therapy is widely used in intensive care units for treating hospital-acquired and ventilator-associated pneumonia caused by multidrug-resistant Gram-negative bacteria, yet its pulmonary delivery performance during invasive mechanical ventilation remains poorly characterized. Methods: An in vitro adult mechanical ventilation model was used. We evaluated two nebulizers (vibrating mesh nebulizer [VMN] and jet nebulizer [JN]) at three positions (standalone nebulizer, 15 cm from the Y-piece, and the humidifier’s dry end) with two artificial airway types (endotracheal and tracheostomy tubes). Lung deposition was predicted using the multiple-path particle dosimetry model, incorporating the Yeh/Schum five-lobe adult lung model. Results: In the standalone setup, the percentage of delivered dose of VMN and JN was approximately 40% and 34%, respectively. Mechanical ventilation significantly reduced the delivered dose (all p ≤ 0.0085), with VMN at the humidifier’s dry end delivering only 2.14–2.99% of the nominal dose. In all the tested ventilation scenarios, both the use of the JN and positioning the nebulizer 15 cm from the Y-piece significantly increased aerosol delivery (all p ≤ 0.021). While the ventilator circuit reduced the total drug amount, it filtered larger aerosols. This resulted in a smaller mass median aerodynamic diameter and a higher fine particle fraction (all p < 0.0001), which doubled the predicted alveolar deposition fraction (from 13–14% in standalone to 23–28% in ventilation scenarios) and eliminated extrathoracic deposition. Conclusions: This study provides the first in vitro and in silico assessment of PMB aerosol delivery during invasive mechanical ventilation. Nebulizer type, its placement within the circuit, and the artificial airway are critical factors that significantly alter the pulmonary delivery of PMB aerosol and subsequently impact its lung deposition. Full article

This study employs CFD simulations carried on ANSYS Fluent 2022 R1 (ANSYS Inc., Canonsburg, PA, USA), to address the design, development, and thermodynamic analysis of a biomass burner, based on mass and energy balances, combustion efficiency, flame temperature, and thermodynamic properties. The prototype incorporates a flow deflector located before the combustion chamber. This component improves the air-fuel mixture to maximise thermal efficiency and minimise pollutant emissions. The burner is specifically designed to use sawdust as fuel and is intended for industrial applications such as heating or drying processes. The integration of the flow deflector results in uniform, complete combustion, achieving 90% thermal efficiency and an adjustable thermal power output of 0–100 kW. Compared to conventional burners, this design reduces CO emissions by 20% and NO_x emissions by 15%, demonstrating significant environmental improvements. The design methodology is based on mass and energy balance equations to evaluate combustion efficiency as a function of the stoichiometric ratio, along with experimental testing. These experimental tests were conducted using an ECOM (America Ltd., Nashua, NH, USA) gas analyser and anemometer. The internal temperature was monitored with a K-type thermocouple (Omega Engineering Inc., Norwalk, CT, USA). The results confirmed the positive influence of the structural design on thermal performance. The proposed burner aims to maximise heat generation in the combustion chamber, offering an innovative alternative for biomass combustion systems. Full article

In January 2025, multiple wildfires erupted across the Los Angeles region, fueled by prolonged dry conditions and intense Santa Ana winds. Southern California has faced increasingly frequent and severe wildfires in recent years, driven by prolonged drought, high temperatures, and the expanding wildland–urban interface. These fires have caused major loss of life, extensive property damage, mass evacuations, and severe air-quality decline in this densely populated, high-risk region. This study integrates passive and active satellite observations to characterize the spatiotemporal and vertical distribution of wildfire emissions and assesses their impact on air quality. TROPOMI (Sentinel-5P) and the recently launched TEMPO geostationary instrument provide hourly high temporal-resolution mapping of trace gases, including nitrogen dioxide (NO₂), carbon monoxide (CO), formaldehyde (HCHO), and aerosols. Vertical column densities of NO₂ and HCHO reached 40 and 25 Pmolec/cm², respectively, representing more than a 250% increase compared to background climatological levels in fire-affected zones. TEMPO’s unique high-frequency observations captured strong diurnal variability and secondary photochemical production, offering unprecedented insights into plume evolution on sub-daily scales. ATLID (EarthCARE) lidar profiling identified smoke layers concentrated between 1 and 3 km altitude, with optical properties characteristic of fresh biomass burning and depolarization ratios indicating mixed particle morphology. Vertical profiling capability was critical for distinguishing transported smoke from boundary-layer pollution and assessing radiative impacts. These findings highlight the value of combined passive–active satellite measurements in capturing wildfire plumes and the need for integrated monitoring as wildfire risk grows under climate change. Full article

Fluidized bed drying has been widely applied in the food industry due to its high heat and mass transfer rates. In this study, the impact of drying temperatures (50, 60, 70 and 80 °C) in a fluidized bed on the physicochemical, functional, morpho-structural, and thermal properties of avocado seed starch was evaluated. The process yield for all temperatures ranged from 52.3 to 58.5% (p > 0.05), with a starch content of 59.20–60.9 g/100 g, amylose content of 28.85–31.84 g/100 g, and amylopectin content of 29.13–30.37 g/100 g. Additionally, all samples showed high water, milk, and oil absorption capacity (>90%), low solubility (5.22–8.35%), good flow characteristics, and swelling power greater than 50%. There was also a greater release of water (syneresis) after 168 h of storage, regardless of the drying temperature, which likewise did not influence the texture parameters. The granules had a smooth surface, without cracks or cavities, predominantly oval and partially rounded, being classified as type B. In the FT-IR analysis, no new functional groups were observed, only a reduction in peak intensity with increasing drying temperature. Finally, the thermal properties indicated high conclusion temperatures (>130 °C), with gelatinization enthalpy in the range of 14.18 to 15.49 J/g, reflecting its thermal resistance and structural integrity under heat conditions. These results demonstrated that fluidized bed drying is an alternative technique for drying avocado seed starch pastes. Full article

The simultaneous stabilization of Cu, Ni, Pb, and As in sustainable environmental development remains a significant challenge in heavy metal remediation. In this paper, liquid phase equilibrium experiments have evaluated the immobilization efficiency of 20 potential stabilization materials. Soil stabilization experiments, material characterization, and long-term effectiveness assessments have been performed to investigate the efficient composite stabilization agent and its underlying mechanisms. Results demonstrate that seven materials, including calcium oxide (CaO) and hydroxyapatite (HAP), exhibit multi-metal immobilization capabilities. Among single-material stabilization in soil, HAP for Pb, zero-valent iron (ZVI) for As, and blast furnace slag (BFS) for Cu exhibit prominent stabilization efficiency, yet they cannot efficiently stabilize the four heavy metals simultaneously. Subsequently, the ZVI:BFS:CaO composite agent (6:3:1 mass ratio, 10% addition rate) has been proposed by formulation optimization, achieving remarkable stabilization rates: 99.92% for Cu, 96.16% for Ni, 92.06% for Pb, and 99.58% for As. XRD, XPS, and SEM-EDS analyses confirm that the stabilization occurs through synergistic mechanisms including precipitation, complexation, and lattice encapsulation. The composite stabilizing agent withstood 15 wet–dry and 150 freeze–thaw cycles, with four types of heavy metals stabilization rates > 60%, confirming its long-term effectiveness. Full article

The continued evolution and advances in Artificial Intelligence (AI) technologies are offering innovative solutions and setting the futuristic trends in the food sector. The use of different Machine Learning (ML)-based models has demonstrated promising applications in the food processing industry. Processing operations such as drying, frying, cooking, heating, and baking are complex and challenged by multifaceted problems due to simultaneous heat, mass and momentum transport processes. The ML-based tools could potentially categorize each food material and efficiently predict its processing kinetics for optimization of the processing conditions. Furthermore, ML technologies have shown excellent applications in ensuring the traceability of food provenance and quality, enhancing the transparency and traceability from farm to fork, and providing consumers with more reliable product information. Overall, ML tools have untapped potential to identify and accelerate multiple development opportunities across the entire agri-food sector to improve productivity, profitability, and sustainability in the future. Full article