Search Results (40,184)

Understanding the thermal decomposition behavior and kinetic characteristics of blended biomass is crucial for optimizing thermochemical conversion processes. This study systematically investigates the synergistic pyrolysis (thermal decomposition) behavior of Salix psammophila (SP) and corn stover (CS) under a nitrogen atmosphere, with particular emphasis on process behavior and reaction kinetics (and thermodynamic feasibility). Based on elemental and proximate analyses, SP provides high calorific value and lignin content, while CS contributes high volatile matter and cellulose, enabling complementary interaction during thermal conversion. Three blending ratios (CS:SP = 2:1, 3:1, and 5:2) were analyzed using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and kinetic evaluation via the Coats–Redfern, Flynn–Wall–Ozawa (FWO), and Kissinger–Akahira–Sunose (KAS) methods, together with thermodynamic parameter estimation (ΔH, ΔS, and ΔG). The results indicate that the 3:1 blend forms an optimized “continuous phase–dispersed phase” structure with an interfacial transition layer of 11–15 μm and uniformly distributed fine pores, promoting effective heat and mass transfer and facilitating volatile-release pathways across the blend interface. At a heating rate of 15 °C·min⁻¹, this blend exhibits the lowest onset temperature of rapid mass loss (T_onset, 209 °C), the highest comprehensive pyrolysis performance index (S_N, 3.01), and stable DTG profiles. Kinetic analysis confirmed that the 3:1 blend exhibits the lowest activation energy during the devolatilization stage, indicating enhanced reaction feasibility under inert conditions. The results provide mechanistic insight into biomass blending effects and offer guidance for process optimization in inert-atmosphere thermochemical conversion systems. Full article

The continuous growth in both the number of phenotypic records and the range of traits included in beef cattle genetic evaluations poses substantial statistical and computational challenges for the estimation of genetic and residual (co)variance matrices required for breeding value estimation. Structural equation models (SEM), implemented using either factor analysis (FA) or recursive model (REC) structures, provide a flexible framework to model genetic and residual (co)variance matrices while yielding more parsimonious and computationally efficient parameterizations. Here, SEM was applied to estimate parameters for growth and ultrasound-measured carcass traits in beef cattle. The dataset comprised 2,942 animals, and six traits were evaluated using standard multiple-trait mixed models (SMTM) and SEM. We considered FA and REC models implemented with six alternative parameterizations, in which random effects were represented as linear combinations of fewer unobservable random variables. Relative to the SMTM, both the model with two factors in the genetic covariance matrix (FA2G) and the model in which six recursive effects were constrained to zero in the residual covariance matrix (REC1) demonstrated a strong ability to capture genetic variability, as reflected by comparable heritability estimates. Correlations between estimated breeding values (EBV) for the same traits across models were consistently high, ranging from 0.94 to 1.00, indicating strong agreement among model estimates. The FA2G model was the most parsimonious in terms of the effective number of parameters ($p_D$), with 431.2 $p_D$, corresponding to a reduction of 25.3 parameters relative to the SMTM. The REC1 model also emerged as a competitive alternative for this dataset, exhibiting a lower $p_D$ (443.6) than the SMTM (456.5) and the most favorable deviance information criterion among all models evaluated (e.g., 37,868.6 for REC1 versus 37,874.7 for SMTM). Overall, these results demonstrate that mixed-effects multi-trait models for beef cattle genetic evaluation can be effectively implemented using FA or REC structures, which provide parsimonious representations of the underlying covariance patterns while maintaining high agreement in EBV. Full article

Despite extensive pore-scale studies on oil–water displacement, quantitative understanding of the dynamic evolution of residual oil morphology and waterflooding efficiency in geologically heterogeneous sandstones remains limited, particularly under large water-injection multiples. To better understand pore-scale oil–water distribution and its influence on enhanced oil recovery, this study utilized Micro-CT combined with SEM-EDS to examine the 3D pore structure and oil–water phase evolution in a heterogeneous sandstone sample from the Xiayang Formation, Wushi Sag, Zhanjiang. Mineralogical analyses reveal that dolomite cementation and vermicular kaolinite infilling introduce strong pore-scale heterogeneity by selectively reducing pore connectivity and permeability, posing challenges for uniform fluid displacement. A 30% KI solution was used to enhance X-ray attenuation of the aqueous phase, enabling clear discrimination between oil and water. Micro-CT reconstructions reveal a relatively uniform pore network dominated by medium-to-large intergranular pores. As the water-injection multiple increases, water progressively invades larger pores, while residual oil is immobilized by capillary forces within micro-throats, forming isolated clusters. The oil-droplet size distribution broadens from a narrow range (50–100 µm) to a wider one (200–300 µm), indicating interfacial destabilization and droplet coalescence. Quantitative analysis indicates that oil saturation decreases from approximately 90% to 36%, while waterflooding efficiency increases rapidly to ~45% at 1 PV and gradually approaches a plateau of ~60% beyond 500–1000 PV. This waterflooding plateau is attributed to capillary trapping and pore-scale connectivity limitations imposed by mineral-induced heterogeneity, which prevent further mobilization of residual oil despite continued water injection. This study advances pore-scale waterflooding research by combining mineralogical heterogeneity with long-term micro-CT imaging, revealing the pore-scale mechanisms controlling residual oil evolution and ultimate waterflooding limits in realistic sandstone. Full article

Directional control of heat flow is essential for advanced energy and electronic systems, yet strategies for tuning anisotropic phonon transport in low-dimensional materials remain limited. Hollow tellurium (Te) nanowires were synthesized via a solvothermal method and modified through Pd electroless plating to achieve tunable anisotropic thermal transport. Structural analyses confirmed Pd incorporation as nanoscale surface deposits without crystalline Pd phases, while SEM observations revealed cavity enlargement due to galvanic displacement at higher PdCl₂ concentrations. Bulk films prepared by cold pressing exhibited direction-dependent behavior. Thermal conductivities remained nearly unchanged below 2.2 mM PdCl₂, but at 5.5 mM, the in-plane value increased to 2.14 W/(m·K) and the cross-plane value decreased to 0.39 W/(m·K), enhancing the anisotropy ratio from 2.71 to 5.49. This divergence arises from direction-selective phonon scattering, where Pd-rich regions promote in-plane heat flow while junction irregularity suppresses cross-plane transport. These results demonstrate a controllable approach for engineering anisotropic thermal properties in functional energy materials. Full article

Background: Surgical tendon rupture repair suffers from scar formation, leading to tendons with inferior mechanics and consequently to re-ruptures, as well as from adhesion formation to the surrounding tissue, reducing the range of motion. In an approach of re-purposing the phytochemical Bakuchiol to be incorporated in the polymer DegraPol^® (DP), we fabricated a novel implant material by emulsion electrospinning. Methods: To characterize the emulsion electrospun novel materials, we used Scanning Electron Microscopy (SEM) to determine the fiber diameter and pore size. In addition, we used Fourier Transformed Infrared Spectroscopy (FTIR). Finally, we planted the materials onto the chorioallantoic membrane of the chicken embryo (CAM assay) to assess tissue integration and collagen expression. Results: While the pure DP meshes were very well integrated in the CAM assay and showed a significantly higher collagen deposition within the scaffold, the DP + Bakuchiol meshes exhibited poor tissue integration, showing rather the beginning of a fibrous encapsulation. Conclusions: The novel electrospun material DP + Bakuchiol could be used as an anti-adhesion barrier to prevent tendon adhesion. Full article

Dental wear provides valuable evidence for reconstructing past human behaviour, including diet abrasiveness and non-masticatory activities such as the use of teeth as a “third hand”. This study investigates activity-induced dental modifications (AIDMs) in two adult human skeletons recovered from a 15th–19th-century necropolis at the St. Athanasius Church in Niculițel (Tulcea County, Romania). Dental remains and associated dental calculus were examined using low- and high-magnification optical microscopy and scanning electron microscopy (SEM). Well-polished grooves with parallel striations were identified on the incisor crowns, consistent with repetitive extra-masticatory activities related to fibre drafting during spinning and textile production. Dental calculus analysis revealed the presence of plant and animal fibres, providing direct micro-contextual evidence for textile-related practices. These results offer new insights into the use of teeth as tools and contribute to the reconstruction of textile-related craft activities during the Ottoman and early modern periods in southeastern Europe. Full article

This study investigates the influence of H13 steel substrate surface roughness on the corrosion behavior of CrAlN coatings in a 3.5 wt.% NaCl solution. The interfacial structure of the coatings and the evolution of corrosion products were characterized using electrochemical techniques, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). Results indicate that reducing the substrate surface roughness from 0.235 μm to 0.167 μm resulted in a proportional decrease in the coating’s critical load (Lc1), from 23.3 N to 17.3 N. Concurrently, the corrosion potential (Ecorr) shifted positively, the charge transfer resistance (Rct) increased significantly, and the corrosion current density (Icorr) decreased markedly. After 14 days of immersion, the most substantial positive shift in Ecorr was observed, moving from −1.038 V to −0.803 V (ΔE = 0.235 V). Rct increased dramatically from 2360 Ω·cm² to 2.772 × 10⁶ Ω·cm², representing an enhancement of two orders of magnitude. Icorr decreased from 7.003 × 10⁻⁵ A·cm⁻² to 1.182 × 10⁻⁶ A·cm⁻², corresponding to a reduction of 98%. Following 20 days of immersion, the sample with a substrate roughness of 0.214 μm exhibited corrosion damage to the underlying substrate. In contrast, the coating on the sample with a lower roughness (0.167 μm) remained relatively intact. Surface roughness directly governs collision, adsorption, and diffusion processes during coating deposition. While higher roughness enhances coating-substrate interfacial adhesion, it concomitantly increases surface porosity, ultimately compromising corrosion resistance. Therefore, practical applications necessitate a comprehensive optimization of coating adhesion strength and corrosion resistance, tailored to specific service environments. Full article

In this work, sustainable aluminum-modified orange peels functionalized with graphene oxide (OP-Al-GO) were synthesized and evaluated for the removal of Methylene Violet (MV) and Reactive Red 120 (RR120) from aqueous solutions. Adsorption performance was systematically investigated in single-dye systems, binary dye mixtures, and real textile wastewater samples, and compared with that of orange peels (OP), orange peel–aluminum composite (OP-Al), and graphene oxide (GO). pH_pzc analysis clarified the surface charge of the adsorbent, while SEM and FTIR showed that the incorporation of aluminum and GO increased roughness and functional groups appearance, enhancing dye adsorption and confirming successful interactions. The OP-Al-GO composites exhibited improved removal efficiency for both dyes (64.8% for RR120 and 96.2% for MV) at pH 3.0. The presence of aluminum improved structural stability and surface charge regulation, while graphene oxide contributed to multiple adsorption mechanisms, including electrostatic attraction and π–π interactions. The adsorption kinetics were found to follow a pseudo-second-order (PSO) kinetic model for RR120 and an intraparticle-diffusion model (IPD) for MV, while isotherm analysis revealed a Langmuir behavior for MV and a Freundlich behavior for RR120. Langmuir maximum adsorption capacities were 298.7 and 10.8 mg/g for MV and RR120, respectively. High removal efficiency was maintained in binary dye mixtures, with OP-Al-GO achieving 96.9% removal of MV and 85.7% of RR120. Furthermore, the proposed adsorbent was tested on real wastewater samples, and the results highlight that the proposed adsorbents are promising, low-cost, and environmentally sustainable for textile wastewater treatment. Full article

Notch wear in austenitic stainless steel turning develops rapidly and remains a key productivity limitation with carbide tools. This work identifies the initiation mechanism of notch wear when turning EN 1.4307 stainless steel using CVD-coated cemented carbide inserts with an Al₂O₃ top layer. Turning tests were performed under dry conditions, followed by optical wear measurements and chip surface analysis. The tool–chip interface chemistry and material transfer were characterized using SEM/EDS, while high-frequency acoustic emissions were recorded to resolve the dynamics of adhesive events. Thermo-mechanical FEM simulations were conducted to map contact pressure and temperature along the cutting edge. The results show that adhesive wear initiates immediately at engagement and governs notch formation: polluted SiO₂ deposits act as an active bonding medium, and repeated bond formation/rupture removes extremely thin flakes of tool and coating material, evidenced by Al₂O₃ and Ti(C,N) fragments on the chip and by characteristic acoustic cluster waves. A new tool–chip contact model is presented, indicating that high pressure and high temperature within the polluted SiO₂ near the chip’s outmost side promote larger, stronger adhesive bonds together with the absence of ceramic particles near the rake in the notch area. Oxidation and diffusion are assumed to be secondary processes that become relevant after local coating loss, while adhesion remains the primary removal mechanism during early and intermediate stages. Full article

Interest in organic food has grown steadily, driven by its health and environmental benefits and concerns about conventional production. Yet organic rice remains largely overlooked, while imported, low-cost inorganic rice dominates the market. This study addresses that gap by extending the Theory of Planned Behavior (TPB) to include environmental concern and knowledge, alongside health consciousness and status, as predictors of purchase intention, and the TPB constructs as mediators. Using survey data from 401 Haitian consumers, we applied structural equation modeling and fuzzy-set qualitative comparative analysis. Results show health consciousness as the strongest and most consistent driver, shaping attitudes, norms, and perceived control, while environmental concern also plays a significant role. Environmental knowledge proved context-dependent, and health status and perceived control were not significant. The mediation analysis revealed several significant indirect effects. Environmental concern influenced behavioral intention through both attitudes and subjective norms, while environmental knowledge showed a significant indirect effect via subjective norms. Health concern demonstrated the strongest mediation effects, with significant pathways through attitudes and subjective norms. In contrast, mediations through perceived behavioral control were consistently non-significant across all tested relationships. The fsQCA analysis identified environmental concern, environmental knowledge, health consciousness, attitudes, and subjective norms as necessary conditions for consumers’ intention to purchase organic rice to occur. This analysis also revealed 22 pathways to high purchase intention, with most pathways including two or three of the identified necessary conditions. These findings advance TPB and offer practical insights for promoting sustainable consumption. Full article

Increased alloying content in advanced Ni-based superalloys for large disc forgings intensifies microsegregation and promotes the formation of detrimental secondary phases, challenging the cast-and-wrought processing route. This study investigates the effects of Ta addition on the solidification and homogenization behaviors of a high-alloyed GH4065A superalloy by comparing the base alloy with a variant containing 5 wt.% Ta (5Ta alloy). As-cast and homogenized microstructures were characterized using SEM and EPMA, solidification behavior was analyzed via DSC, and homogenization kinetics were modeled. Results demonstrate that Ta addition stabilizes the η phase, increasing its solidification temperature and fraction in the as-cast microstructure, but does not alter the solidification sequence. During homogenization, Nb remained the most segregated element and governed the homogenization kinetics, whereas Ta preferentially partitioned into MC carbides and the η phase. The diffusion activation energy for Nb in the 5Ta alloy was determined, and a diffusion model was established to describe the elimination of microsegregation. Optimum homogenization parameters were determined to completely dissolve the η phase and eliminate microsegregation. The results indicate that strategic Ta addition for enhanced performance does not compromise ingot manufacturability, providing valuable guidance for the processing and composition design of advanced disc superalloys. Full article

Affiliated Open Spaces (AOS) constitute vital public assets within high-density vertical cities. However, prevailing scholarship remains largely confined to two-dimensional horizontal perspectives, overlooking the quantitative impact of vertical built environment characteristics on spatial distribution and human behavior. Focusing on four high-density districts in Guangzhou typified by distinct three-dimensional morphologies, this study integrates field surveys, 3D geospatial data acquisition, and 621 valid questionnaires to empirically analyze the impact of 3D spatial features on user behavior and the mediating role of accessibility. Utilizing the ArcGIS 3D Analyst for vertical accessibility measurement and Partial Least Squares Structural Equation Modeling (PLS-SEM) for path analysis, the study tests the hypothesized relationships using multi-source data. The results indicate that (1) a user’s vertical location exerts a significant negative impact on both accessibility and human behavior; (2) building density and building functional diversity indirectly promote user engagement primarily by significantly enhancing accessibility, thereby confirming accessibility as a critical mediator; and (3) significant spatial heterogeneity exists, revealing distinct correlation patterns across varying built environments. This research elucidates the pivotal constraint of “vertical location” and validates the mediating efficacy of accessibility, offering empirical insights for human-centric vertical urban planning. Full article

Background: Artemisia annua L. is a medicinal plant with documented antimicrobial, antioxidant, and anti-inflammatory properties. Although widely studied for internal therapeutic applications, its topical use—especially in hydrogel-based systems—has not been thoroughly investigated. The aim of this study was to develop sodium alginate hydrogels containing Artemisia annua extract, supplemented with hyaluronic acid and dexpanthenol, and to evaluate their physicochemical characteristics as well as their biological activities in vitro and in vivo. Methods: Select bioactive constituents of the Artemisia annua extract were quantified using liquid chromatography coupled with electrospray ionization mass spectrometry (LC-ESI-MS). Hydrogels were prepared by cross-linking sodium alginate with a calcium carbonate–glucono-delta-lactone system and were formulated with or without hyaluronic acid and dexpanthenol. Physicochemical evaluations included measurements of moisture content, water-retention capacity, gelation time, and pH. The hydrogel microstructure was examined by scanning electron microscopy (SEM). Antioxidant activity was assessed using three methods: the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, the ferric reducing antioxidant power (FRAP) assay, and the cupric reducing antioxidant capacity (CUPRAC) assay. Biocompatibility and regenerative effects were analyzed using cell viability assays and an in vitro scratch wound model on human keratinocyte cells. In vivo wound-healing efficacy was examined in rats with full-thickness skin excisions. Results: The extract contained high levels of methylated flavonoids and sesquiterpenes characteristic of Artemisia annua. Hydrogels supplemented with hyaluronic acid and dexpanthenol exhibited improved hydration stability and higher porosity. All formulations demonstrated measurable antioxidant activity, and those containing hyaluronic acid showed the strongest effects. The preparations were biocompatible and enhanced keratinocyte migration in vitro, with the combined hyaluronic acid–dexpanthenol formulation promoting the fastest wound closure. In vivo, Artemisia annua hydrogels accelerated wound healing by two to three days compared with untreated wounds. Conclusions: These results confirm the promise of Artemisia annua hydrogels for topical wound care and highlight the beneficial contributions of hyaluronic acid and dexpanthenol to their structural and therapeutic performance. Full article

In this study, poly(lactic acid) (PLA) composites reinforced with lignocellulosic materials were developed to reduce the environmental impact of plastics. PLA–biomass composites, incorporating cork, rice husk, coffee grounds, or oak gall at loadings of 2.5% to 20.0% (w.w⁻¹), were produced via melt extrusion and subsequently used in 3D printing. The results showed that the incorporation of biomass reduced the mechanical performance of the composites despite being adequate for 3D printing. Rice husk and coffee grounds increased filament density, whereas cork and oak gall decreased it. Thermal properties were largely preserved, with glass transition temperatures (T_g) near 70 °C and decomposition temperatures well above the printing temperature, indicating that thermal resistance was not compromised. SEM analysis of the printed objects revealed good layer definition for neat PLA and rice husk composites, highlighting rice husk as the most promising biomass filler in terms of print quality. Hence, the results demonstrated that incorporating rice husk into PLA offers a viable route for more sustainable composites suitable for additive manufacturing. Full article

Impact toughness of three different samples was evaluated using an instrumented Charpy pendulum combined with fractography performed using scanning electron microscopy (SEM) to analyze the effects of heat treatment and vanadium as alloying element. Samples were made from Mn16V with water quenching and aging (WQA), as well as from Mn16V and Mn16 with WQA and additional aging (WQAA). It was concluded that vanadium reduced impact toughness, whereas the additional aging had practically no effect. Full article