Search Results (2,767)

This paper focuses on analyzing the corrosion mechanism of stone cutting tool surfaces. Rare earth oxide films were prepared on the tool surface using the electrophoretic deposition–sintering method, and their corrosion resistance was investigated. Microstructural and compositional analyses of the surface layer of shot-peened tools and rare earth oxide films were conducted using characterization techniques such as SEM, EBSD, and XRD. The corrosion resistance of the rare earth oxide films was evaluated via an electrochemical workstation. The results indicate that the corrosion morphology on the stone cutting tool surface is pitting corrosion, which is significantly influenced by the friction of the tool coolant. Shot-peening treatment refines the grains in the tool surface layer, promoting the growth of rare earth oxide films. The rare earth oxide film is mainly composed of cerium oxide (CeO₂), presenting a continuous and dense structure with slight peeling after sintering. The Group 3 (0.1 mol/L, 3000 V/m, 5 min) rare earth oxide film exhibits the optimal electrochemical behavior and excellent corrosion resistance, with a corrosion potential (Ecorr) of −0.49 V and a corrosion current density (icorr) of 1.445 × 10⁻⁷ A/cm². Full article

This study examines the impact of recovered steel fibers (WTSFs) and waste tire aggregates of varying sizes—fine (FWTR), small coarse (SCWTR), and large coarse (LCWTR)—on the compressive strength of concrete subjected to elevated temperatures. Forty mixes were formulated utilizing four distinct WTR replacement ratios (0%, 5%, 10%, 20%) and four WTSF doses (0%, 0.5%, 1%, 2%), and evaluated at temperatures of 24 °C, 100 °C, 200 °C, and 300 °C. The findings indicate that elevated temperatures consistently diminish compressive strength, although the reference concrete saw around 18% loss at 300 °C, with WTR-containing mixes demonstrating losses ranging from 25% to 45%, contingent upon rubber size and dose. The type of WTR was critical—LCWTR mixes exhibited superior residual strength retention due to enhanced particle–matrix interlocking, whereas FWTR mixtures saw the most significant decline. The inclusion of WTSF increased strength by 2–10% at 0.5–1.0% fiber content through crack bridging, but excessive fiber addition (2.0%) decreased workability and caused clustering, leading to up to 40% strength loss. The ideal combination was 5LCWTR–1WTSF, which sustained 36.97 MPa at 24 °C and 29.65 MPa at 300 °C, indicating superior performance across all temperature ranges. Predictive modeling utilizing machine learning techniques (SVR, KRR, 1D-CNN, and DRL) corroborated the experimental results, with the CNN attaining the maximum generalization accuracy (R² = 0.9374) and the KRR exhibiting the most consistent performance (R² = 0.9305). The models indicated that WTR and temperature were the primary variables diminishing strength, although modest WTSF ratios enhanced overall thermal resilience. SHAP and ALE analysis further validated that WTR content exhibited the most significant negative feature contribution (~−6 MPa), succeeded by temperature, although modest fiber inclusion demonstrated a positive SHAP effect (+2–4 MPa), corroborating the experimentally observed non-linear reinforcement threshold. The combined experimental–computational framework demonstrates that the combination of coarse rubber aggregates (5–10%) with appropriate WTSF content (0.5–1.0%) improves sustainability and high-temperature durability. The integration of physical testing and interpretable AI modeling creates a hybrid approach that can anticipate and enhance thermo-mechanical performance in sustainable concrete systems. Full article

The research employs principal component analysis to construct composite indices for China’s economic policy uncertainty (EPU), the green stock market, and the traditional stock market. Using nonlinear Granger causality tests and a Time-Varying Parameter Structural Vector Autoregression with Stochastic Volatility (TVP-SVAR-SV) model, it systematically examines the dynamic time-varying impact mechanism of China’s EPU on price volatility in the green securities and traditional financial markets. This research provides a crucial theoretical foundation and empirical reference, grounded in a nonlinear and time-varying perspective, for coordinating policy interventions to stabilize both traditional and emerging financial markets during the transition towards a green economy. The findings indicate: (1) An asymmetric risk transmission mechanism exists between the traditional financial and green securities markets in China, with the influence from the traditional financial market to the green securities market being stronger. (2) The influence of EPU in China on the green securities market exhibits time-varying characteristics that differ across periods. For instance, the Russia–Ukraine Conflict saw the green stock market’s most notable short-term negative response to EPU shocks. (3) The traditional financial market shows varied responses to China’s EPU shocks. China’s money market demonstrated a highly similar negative response pattern across three distinct periods. Full article

Plasma regeneration was investigated as a means of regenerating microstructures on biosensors for repeated use. These microstructures were based on the deposition of suspensions containing polymer microspheres. While this method provides a simple way to structure surfaces, obtaining regular structures in a reproducible way remains a challenge. Therefore, it would be advantageous to be able to reuse regular structures, which requires regeneration. To investigate this concept, surface acoustic wave (SAW) resonators were structured using 5 µm and 20 µm polystyrene microspheres and coated with parylene C to stabilize the particle structures. After use in bioanalytical experiments, the biological residues and the parylene C cover layer were removed with plasma, and a new parylene C layer was added. Both atmospheric and low-pressure plasma were tested for regeneration. As a result, the low-pressure plasma was to be preferred because it did not damage the transducer structures on the SAW resonators, unlike the atmospheric plasma. Water contact angle measurements and transmission spectra recorded with a network analyzer confirmed that freshly prepared and regenerated structured SAW resonators coated with parylene C exhibited similar wetting properties and resonance parameters. Therefore, plasma regeneration is an effective way to enable the reuse of perfectly structured SAW resonators. Full article

The photovoltaic industry generates a substantial amount of high-purity waste silicon powder during the diamond-wire saw cutting process, which can serve as an environmentally friendly and cost-effective resource for lithium-ion battery recycling. However, its commercial application is hindered by the surface attachment of silicon dioxide, organic substances, metal impurities, as well as its intrinsic drawbacks such as significant volume expansion (>300%) during lithium (de)intercalation and low electronic conductivity. To address these issues, this study first purifies the waste silicon powder and then designs the structure of the composites. Using a simple ball-milling combined with sol-gel method, a core-shell composite material with a carbon-coated two-dimensional conductive network (FVW-Si/G₅₀₀@C) was synthesized. The two-dimensional conductive network provides sufficient space to accommodate the volume expansion of silicon, while the mesoporous structure on the carbon shell offers a fast transport pathway for Li⁺, thereby enhancing the electrode kinetics. The prepared FVW-Si/G₅₀₀@C electrode maintained a high reversible capacity of 951.8 mAh g⁻¹ after 100 cycles at a current density of 0.2 A g⁻¹. Even at a high current density of 1 A g⁻¹, it retained a reversible capacity of 230.4 mAh g⁻¹. The results indicated that the synergistic effect between graphite sheets and the mesoporous carbon shell significantly improved the rate performance and cycling stability of the FVW-Si/G₅₀₀@C electrode. This study provided a theoretical foundation for the scalable, green, and high-value utilization of waste silicon powder in the photovoltaic industry and offered technical support for sustainable energy development. Full article

Why do some organic farming systems persist while others collapse despite similar histories of collective action, policy support, and social legitimacy? This study examines how institutional design shapes the resilience of organic rice systems under conditions of market volatility and buyer power. Drawing on a qualitative comparative analysis of two subnational cases in rural Indonesia—Magelang and Tasikmalaya—Magelang experienced only 6–8% reversion to conventional rice (≈4.2 ha lost), while Tasikmalaya saw 32–38% reversion (≈13–17 ha). The study applies and extends the Institutional Analysis and Development (IAD) framework to foreground market risk governance as a central explanatory variable. The findings show that sustainability depends less on collective organisation than on whether producer institutions function as risk-bearing actors. In Magelang, a farmer cooperative governed market relations through internal monopsony and buyer diversification, shifting market risk from individual households to the organisational level. In Tasikmalaya, reliance on an external monopsony concentrated risk outside producer control; when buyer demand weakened, risk was rapidly transferred to farmers, triggering institutional fragmentation and exit from organic production. By distinguishing internal from external monopsony, the study advances an institutional explanation of resilience in market-mediated sustainability transitions and suggests that policies should prioritise institutional capacity for market risk governance over certification or production technologies. Full article

Background: Children with emotional disturbance (ED) frequently display highly unpredictable behaviors compared to other children. The magnitude and unpredictability of childhood ED make finding effective management strategies difficult for parents. Prior research has examined parents’ stress and the children’s behaviors in schools, but we know very little about how parents manage at home. Methods: This qualitative study used Naturalistic Inquiry to explore how parents respond to the challenges which arise at home due to childhood ED. Eight mothers raising 10 children with ED were recruited nationally. Data were gathered through semi-structured, individual interviews. Results: Consequences-based parenting strategies were unsuccessful, but mothers achieved greater success with pre-planned, intentional responses and adapting the child’s environment. Mothers learned their child’s world view was very different than their own. This realization caused mothers’ perspective toward their child to change. Mothers saw their child as struggling with a problem, instead of simply being defiant. The perception shift allowed mothers to approach situations with greater compassion and inner peace. Conclusions: The findings provide suggestions for pediatric healthcare providers who work with such parents seeking assistance and advice. Full article

Background: Healthcare workers are at the forefront of the global battle against COVID-19. Their vaccination perspectives, particularly in regions like Sierra Leone that have faced health crises such as the Ebola outbreak, are essential for shaping public health strategies in low-income countries that routinely face infectious disease outbreaks. Objective: This research sought to understand the perceptions and experiences of Sierra Leone’s healthcare workers concerning COVID-19 vaccination and booster doses, set against the backdrop of global health resource disparities and regional vaccine distribution challenges. Methods: Utilizing a mixed-methods approach, the study analyzed data from an online survey, which saw 1001 complete responses from 2060 participants across six Ebola-impacted districts (October–November 2022), and in-depth interviews with 24 health workers from three of these districts (February–July 2022). Results: Approximately 80% of respondents reported having received a COVID-19 vaccine, predominantly Sinopharm and AstraZeneca, yet only 34% of vaccinated participants had received a booster dose. In multivariable analyses, personally knowing someone who experienced serious COVID-19 illness or death was associated with higher odds of both initial vaccination and booster uptake (p < 0.05). By contrast, prior Ebola-related experiences were not consistently associated with vaccination outcomes. Qualitative findings contextualized these patterns, highlighting the roles of professional exposure, limited booster-related information, and inequities in vaccine availability and distribution. Conclusion: These findings indicate that vaccination strategies must move beyond initial rollout to address barriers to sustained engagement, particularly for booster uptake among healthcare workers. They also emphasize the need for equitable vaccine access and transparent, locally tailored communication to mitigate structural and informational constraints in low-income settings. Full article

Total factor productivity (TFP) serves as the primary driver of high-quality development and a key determinant for the sustainable growth of Japan’s beef cattle industry. This study analyzes panel data from nine agricultural regions in Japan, covering the period from 2004 to 2022, and applies the Malmquist-Luenberger index model to measure and decompose TFP in the sector. It utilizes various methods, including the Dagum Gini coefficient, kernel density estimation, and Markov chains, to examine regional disparities and dynamic changes. Additionally, the study applies the geographic detector and spatial Durbin model to explore the spatiotemporal evolution and influencing factors. The results show that: (1) From 2004 to 2022, TFP in Japan’s beef cattle industry steadily declined, accompanied by growing regional imbalances. The Tokai region was the only area to experience positive TFP growth, while other regions generally saw declines. (2) The spatial disparity in TFP growth has increased, with an intensified imbalance and a widening gap between regions. TFP distribution is becoming more “multipolar,” with considerable dynamic mobility. (3) TFP exhibits a general positive spatial correlation. Geographic detector analysis reveals that factors such as the number of agricultural research and development personnel, fiscal support, industrial agglomeration, feed production capacity, and labor productivity are the key drivers behind spatial TFP differentiation, reflecting a complex interplay of multidimensional factors. (4) Industrial agglomeration, fiscal support, and the number of agricultural R&D personnel exhibit significant spatial positive spillover effects, indicating that coordinated regional progress is essential for fostering the sustainable and healthy development of the beef cattle industry. This study provides theoretical and empirical support for the sustainable development of Japan’s beef cattle industry and offers policy recommendations to enhance the economic growth quality of the beef cattle industries in both Japan and China. Full article

This study aims to explore perceptions among students at Jordanian universities regarding “wasta,” defined as the use of social relations or kinship ties to pressure faculty members into granting them undeserved academic privileges, and to examine the impact of these perceptions on their academic behaviors and attitudes toward their institution. The study uses Travis Hirschi’s Social Bond Theory, which posits that the strength of social bonds is determined by four key elements: attachment, commitment, involvement, and belief. The researchers designed a survey using a proportionally stratified random sample of 748 students from two universities in the south of Jordan. The data were collected using a questionnaire whose validity and reliability were deemed suitable for analysis. The findings reveal a varying degree of erosion in social bonds as follows: while students expressed a rejection of wasta on ethical grounds, the involvement of others in such behavior to gain unearned academic advantages undermined their sense of belonging to the university. Participants also indicated that their peers’ reliance on wasta devalued their individual efforts and weakened trust in the fairness of the educational institution. Furthermore, students’ motivation to participate in campus activities was lower when they perceived that opportunities were granted based on connections rather than merit, while statistical significance was observed only for the involvement dimension in favor of the public university. Last, some students saw wasta as a practical resource in the absence of institutional justice, even if they recognized the harm it causes to academic integrity and the value of university credentials. The findings highlight the importance of addressing wasta within academic institutions by strengthening transparent decision making and academic integrity safeguards to enhance fairness and strengthen trust. Full article

Background: Facial asymmetry affecting the mandibular contour may significantly impact facial harmony even in patients with stable occlusion. Although orthognathic surgery remains the standard for skeletal correction, it carries substantial morbidity. In selected cases, contour-focused approaches can achieve meaningful esthetic improvement with reduced surgical burden. Objective: To describe the virtual surgical planning (VSP) workflow and clinical outcome of a unilateral Wing osteotomy for mandibular contour asymmetry. Case presentation: A 24-year-old woman presented with left-sided mandibular contour deficiency and facial asymmetry, despite stable Class I occlusion and preserved function. VSP with contralateral mirroring guided the design of the osteotomy and fabrication of a stereolithographic model and patient-specific cutting guide. Surgery was performed through a tunnelized mandibular approach using a 702 bur and reciprocating saw. Fixation was achieved with pre-bent 2.0 plates adapted to the 3D model, and Bio-Oss Collagen was interposed within the osteotomy gap. Occlusion and mental nerve function were preserved. Results: Postoperatively, the patient demonstrated improved facial symmetry, uneventful healing, preserved long-term neurosensory function, and high esthetic satisfaction. Conclusions: Unilateral Wing osteotomy guided by VSP and patient-specific instrumentation is a predictable, minimally invasive alternative to bimaxillary orthognathic surgery with genioplasty in selected patients presenting contour-focused asymmetry and stable occlusion. This case highlights a rare, underreported application of the technique. Full article

This study evaluated the potential of sawdust as an inducer of carbon for the production of lignocellulolytic (cellulase and xylanase) enzymes by filamentous fungi for biofuel applications. Fourteen soil samples were collected from a phosphate mine in Phalaborwa, South Africa. Filamentous fungi were isolated from these samples using cellulose and xylose media. These isolateswere tested qualitatively and quantitatively for endocellulase and xylanases. Four isolates were found to have promising xylanase activity and these were identified as Amesia atrobrunnea, Penicillium citrinum, Rhizopus azygosporus and Aspergillus quadrilineatus using ITS1/2 sequencing. A time-course assay for xylanase activity revealed that R. azygosporus and A. quadrilineatus exhibited the highest activity. The crude enzymes were extracted from these strains and used for the enzymatic saccharification of the untreated sawdust. The total reducing sugars were estimated using the DNS method. The results for the enzymatic saccharification showed that a high total reducing sugar concentration of 2.35 g/L was released by 20 U/g of crude xylanases from A. quadrilineatus after 60 h of hydrolysis, while the synergistic hydrolysis of sawdust with the commercial cellulase, Celic CTec2, and the crude enzyme of 6 U/g from A. quadrilineatus showed the maximum concentration of total reducing sugars of 1.41 g/L after 72 h. Sawdust proved to be an effective inducer of xylanase production, although it was less effective for cellulase. This study reports that the commercial cellulase was outperformed by the crude enzymes during hydrolysis, highlighting the possibility that commercial enzymes may be replaced by microbial enzymes, thus lowering the environmental hazards of chemical formulations. Sugar yields could potentially be improved through biomass pretreatment, enzyme purification and strain improvement. Full article

Background: Traditional high-speed mechanical osteotomes cause substantial thermal and mechanical trauma, impairing bone healing. Erbium-doped yttrium-aluminum-garnet (Er:YAG) lasers, with water-mediated non-contact ablation, offer precise osteotomy potential with minimal collateral damage. This study demonstrated the feasibility of Er:YAG laser use for complex osteotomies and elucidated its multi-scale biological impacts on bone. Methods: A custom Er:YAG laser performed Z/arc-shaped osteotomies on fresh ovine bone (oscillating saw as control); paired rat tibial osteotomies; and compared laser vs. saw resection. Osteotomy surfaces were characterized by SEM/micro-CT; histological staining quantified thermal/mechanical damage. Bone marrow-derived mesenchymal stem cell (BMSC) adhesion, viability, and infiltration on cut surfaces were evaluated via LSCM. Result: In the ex vivo ovine model, the Er:YAG laser enabled precise execution of complex osteotomies (Z-shaped and arc-shaped), producing significantly narrower gaps than the oscillating saw (1.14 mm vs. 2.70 mm, p < 0.001) with high geometric fidelity and smooth surfaces free of burrs, micro-cracks, or debris. In the in vivo rat model, laser ablation simultaneously minimized both thermal and mechanical damage at the osteotomy interface: it reduced the thermal damage depth (154 vs. 592 µm, p < 0.001) and empty lacunae rate (16.8% vs. 41.8%, p < 0.001) while completely avoiding the mechanical damage zone (297 µm) induced by sawing. Furthermore, the laser-ablated surface established a highly bioactive interface, which significantly enhanced the adhesion (606 vs. 389 cells), viability (86.9% vs. 46.6%), and infiltration depth (196 vs. 75 µm) of bone marrow-derived mesenchymal stem cells (all p < 0.001). Conclusions: In conclusion, this proof-of-concept study demonstrates that the Er:YAG laser has the potential to enable precise bone resection while preserving microstructure. By establishing a pro-regenerative microenvironment, this technology shows promise as a biologically favorable alternative to conventional sawing, although further technical refinement and long-term validation are essential for its clinical translation. Full article

Against the global push for “carbon peak and carbon neutrality” and Xinjiang’s role as a major arid-region agricultural base in China, balancing agricultural development with low-carbon transitions remains challenging due to its fragile ecology and resource-intensive farming. However, county-scale dynamics of cultivated land carbon emission intensity (CEI) and its drivers in Xinjiang are understudied, limiting targeted mitigation. This study analyzed Xinjiang’s cultivated land CEI (2000–2020) using the Geographically and Temporally Weighted Regression and Stochastic Impacts by Regression on Population, Affluence and Technology (GTWR-STIRPAT) model, geodetector, and spatiotemporal analysis, with counties as units. Data included 30 m-resolution land use data and socioeconomic statistics. Results showed CEI rose from 0.270 to 0.377 t/hm², with marked spatial differences: northern Xinjiang saw fluctuating growth and a 58.65 km northeastward shift of emission gravity, while southern Xinjiang had lower western CEI (ecological constraints) and higher eastern CEI (agricultural expansion). Key drivers were total sown area (TSAC), agricultural film usage (UAPF), and rural agricultural population (RAP). Factor interactions (machinery power × sown area, q = 0.844) non-linearly amplified CEI. The GTWR-STIRPAT model (R² = 0.97) outperformed OLS and captured heterogeneity—mechanization/area expansion dominated northern CEI, while film use/population mattered more in the south. Region-specific strategies are needed: northern Xinjiang should optimize machinery energy and control area expansion; southern Xinjiang, strengthen ecology and promote low-carbon inputs; eastern Xinjiang, leverage efficient oasis agriculture. This study supports precise carbon management in Xinjiang and similar arid regions globally. Full article