Search Results (585)

To address the issues of high cutting temperatures and severe tool wear during titanium alloy machining, this study proposes a hybrid surface modification strategy combining micro-textures and multicomponent titanium nitride (TiN)-based coatings on cemented carbide tools. Using YG8 cemented carbide as the substrate, micro-dimple textures were fabricated by fiber laser, and three coatings with different architectures (TiAlSiN, TiSiN/TiAlN, and TiSiN/TiAlSiN/TiAlN) were deposited via multi-arc ion plating technology. Based on a two-factor (texture diameter and texture spacing) and three-level orthogonal experiment, the evolution behaviors of surface morphology, phase composition, and mechanical properties of the textured multicomponent TiN-based coatings were systematically characterized and comparatively analyzed. The results reveal that: compared to the monolithic-structured TiAlSiN coating, the TiSiN/TiAlSiN/TiAlN and TiSiN/TiAlN composite coatings with multilayered composite structures can effectively relieve the residual stress inside the film–substrate system, and significantly suppress the phenomena of coating cracking and localized spallation caused by irregular protrusions of the recast layer at the micro-texture edges. X-ray diffraction (XRD) and crystallite size analyses indicate that the amorphous Si₃N₄ phase promoted by the Si element in the composite coatings effectively impedes the growth of TiN columnar crystals, achieving significant grain refinement. Mechanical property tests confirm that the existence of multicomponent composite interfaces effectively hinders dislocation movement. Among them, the textured TiSiN/TiAlSiN/TiAlN composite coating exhibits the optimal comprehensive performance; its microhardness, nanohardness, and H/E ratio (characterizing the resistance to plastic deformation) are increased by 17.94%, 8%, and approximately 45%, respectively, compared to those of the textured TiAlSiN coating. This study deeply elucidates the synergistic strengthening and toughening mechanisms between micro-texture parameters and the internal structures of the coatings, providing important theoretical guidance and experimental data support for the surface design of long-lifespan tools oriented towards the high-efficiency machining of titanium alloys. Full article

Prolonged sitting with poor posture is associated with musculoskeletal disorders, reduced productivity, and long-term health risks. Many existing posture monitoring systems predominantly rely on single-modality sensing, such as pressure or vision-based approaches, limiting their ability to capture both static alignment and dynamic micro-movements. This study proposes a multimodal smart-skin system integrating pressure, temperature, and vibration sensors for sitting posture recognition. A total of 42 sensors distributed across 14 anatomical locations were deployed, generating 15,037 samples collected over three independent sessions to evaluate cross-session temporal generalization across nine posture classes under controlled experimental conditions. Two deep learning architectures—Temporal Convolutional Networks with Attention (TCN + Attn) and Convolutional Neural Network–Long Short-Term Memory (CNN − LSTM)—were compared under Leave-One-Session-Out (LOSO) cross-validation. TCN + Attn achieved 85.23% LOSO accuracy, outperforming CNN − LSTM by 2.56 percentage points while reducing training time by 36.7% and inference latency by 33.9%. Ablation analysis revealed that temperature sensing was the most discriminative unimodal modality (71.5% accuracy), and full multimodal fusion improved LOSO accuracy by 22.93% compared to pressure-only configurations. These results demonstrate the feasibility of multimodal smart-skin sensing combined with temporal convolutional modeling for cross-session posture recognition and indicate potential for efficient real-time, privacy-preserving ergonomic monitoring. This study should be interpreted as a controlled, single-subject proof-of-concept, and further validation in multi-subject and real-world environments is required to establish broader generalizability. Full article

As large language models (LLMs) pursue higher accuracy, their model sizes have surged, substantially increasing GPU memory consumption. Prior work mitigates this issue by distributing the memory burden across multiple GPUs. However, on clusters interconnected via Ethernet, the resulting computational intensity is insufficient to hide the significant network latency. Achieving a favorable compute-to-communication ratio is further constrained by the memory required to cache the massive activations generated during the forward pass. PyAO, proposed in this paper, effectively offloads activations, selects offloading strategies based on their offloading efficiency, and minimizes data-movement bottlenecks, thereby enabling larger micro-batch sizes. In Ethernet-interconnected cluster environments, experiments on popular models—including OPT-1.3B, GPT-0.8B, and Llama-1.2B—demonstrate that PyAO reduces peak GPU memory by up to 1.94× at the same micro-batch size, enables up to 2.5× larger batch sizes, and accelerates training by up to 3.63× relative to the baseline. Full article

In many non-tourism historical districts in China, property division has subdivided traditional dwellings into multi-household units. While such subdivision reshapes spatial sequences and connections, its consequences for everyday space use and circulation are rarely documented with continuous in situ evidence, partly because residential behaviour is temporally continuous and difficult to observe directly. This study examines two typical subdivision patterns in Subu Old Street: a longitudinal, single-axis serial dwelling (Case A) and a transversal, courtyard-centred dwelling (Case B). We formalize spatial units, connections, and operational nodes using a semantic ontology and map day-long Ultra-Wideband (UWB) trajectories to quantify occupancy and transition characteristics. Case A concentrates both staying and passing at the entrance-end kitchen, where activities overlap with through-movements and transition durations are short in most events but highly volatile with a long tail. Case B channels most transitions through the courtyard hub, keeping indoor rooms mainly for staying and producing longer but more stable transition durations. This study is positioned as a comparative exploratory case study of two representative subdivision patterns identified in Subu Old Street. Semantic ontology modelling, UWB-based behavioural tracking, and behavioural indicators are used together in a comparative analytical approach for examining how subdivision reorganises spatial structure and everyday residential behaviour. The results reveal pattern-specific differences in occupancy concentration, transition organisation, and movement duration. These findings are analytical observations derived from two representative cases. They provide a basis for spatial adjustment and micro-regeneration in still-inhabited subdivided traditional dwellings. Full article

Rapid urbanization-induced extreme rainstorms severely disrupt social functions. Previous research often focused on “de-densification” strategies, which are difficult to adapt to high-density Sponge City Stormwater Management Units (SMUs) that carry core development functions. This study uses Shenzhen as a case study, utilizing Keep movement big data as a “social sensor” for system function perception and introducing the Socio-Ecological-Technological Systems (SETS) theory to construct a “recovery (RCN)–resistance (MI)” binary assessment framework. Through systematic clustering and hierarchical regression models, the driving mechanisms of blue landscape patterns, topography, road networks, and the built environment on social behavioral resilience are systematically parsed. The results show: (1) Road network morphology dominates resistance, while multi-dimensional elements collaborate for recovery. Resistance (MI) is primarily dominated by macro road network detour resistance (TPD2000, β = 0.956), while recovery depends on the synergistic support of blue space interspersion (Blue_IJI), topography, and micro-circulation road networks. (2) Green infrastructure fails in the model due to efficiency bottlenecks, empirical evidence of weakened regulation caused by green space fragmentation in ultra-high-density environments. (3) Low-density, eco-centric built environments provide dual synergistic gains for resilience. Based on this, a “Bidirectional Socio-Ecological Resilience Needs Pyramid” model is constructed, identifying four governance types such as the “Synergistic Balanced Type”. This study provides a quantitative basis for the transition from administrative control to precise morphological governance in high-density cities. Full article

Background: Traditional functional mobility assessments often fail to detect subclinical postural decline in active aging populations. This study introduces the Head–Sternum Dissociation Index as a novel digital biomarker to identify latent sensorimotor deficits before macroscopic balance failure occurs. Methods: Ninety-four participants (Young, Middle-Aged Civil, Middle-Aged Dancers, and Older Adults) performed instrumented limits of stability tasks, specifically functional and lateral reach tests, utilizing a three-sensor inertial measurement unit configuration. Postural strategies were quantified via the Head–Sternum Dissociation Index and the peak ratio of corrective micro-movements, validating the sensor output against a gold-standard force platform. Results: A significant kinematic breakpoint in postural control was identified at age 55 (p < 0.001). However, Middle-Aged Civilians exhibited early kinematic divergence despite maintaining normal Timed Up and Go test performance. Receiver operating characteristic analysis revealed distinct, sex-specific physiological limits: aging males predominantly adopted a rigid “Stiffness” strategy (peak ratio ≤ 1.15, head–sternum dissociation threshold > 0.63°), while females utilized a broader, more permissive “Continuous” strategy (head–sternum dissociation threshold > 0.31°). Notably, recreational rhythmic training (dance) completely neutralized this age-related decay, with middle-aged dancers maintaining highly efficient, youthful stabilization profiles (Cohen’s d = 2.20). Conclusions: The Head–Sternum Dissociation Index, combined with relative corrective frequency, successfully phenotypes early sensorimotor erosion. These findings advocate for the integration of sex-specific kinematic screening into primary care, allowing clinicians to prescribe targeted interventions well before clinical fall risk manifests. Full article

This conceptual and spiritual autoethnographic essay proposes tendering masculinities as a framework for late-life formation that moves men from performance to presence and from control to communion. Drawing on Jungian alchemy (nigredo, albedo, rubedo) and the movements of decolonizing, queering, and befriending, the piece integrates fieldnotes with theological and depth-psychological reflection to articulate three interwoven practices for elderhood: imperfection as belonging, brokenness as illumination, and holding opposites without hardening. The argument reframes masculine strength as reliable, relational tenderness expressed through micro-practices such as grief literacy, “weaponless speech,” soul friendship (anam cara), and collaborative mentorship within families and intergenerational relationships. Implications are offered for chaplaincy, pastoral counseling, spiritual direction, men’s groups, social work, and family or community contexts, with guidance on designing rituals of lament, contemplative listening, and communities of “steady tenderness.” By bridging depth psychology, poetic theology, and lived practice, the essay suggests that tendered masculinities can help families and relational systems cultivate stronger spiritual resilience, counter patterns of domination or disconnection, and contribute to communal healing. Limitations of single-author autoethnography and pathways for applied, practice-based research are noted. Full article

The lack of integrity at the implant–abutment junction (IAJ) contributes to problems such as micromovements and microbial colonisation. This study aimed to (1) design a protocol for assessing microleakage at the IAJ using chromophore analysis not previously reported for this specific application, (2) compare gas and dye leakage between titanium (Ti) and cobalt chrome (CoCr) abutments, and (3) assess the effect of gold (Au) gilding on sealing. Forty abutments were divided into five groups: milled Ti (MTi); cast CoCr (CCoCr); milled CoCr (MCoCr); cast CoCr with Au gilding (CCoCrG); and milled CoCr with Au gilding (MCoCrG). Samples were subjected to internal pressure within a gas and dye reservoir. Chromophore analysis via UV-Vis spectrometer was used to calculate crystal violet leakage concentrations. Scanning electron microscopy (SEM) revealed close adaptation in the MTi and MCoCr groups, contrasting with irregularities in the CCoCr groups. Correspondingly, gas leakage and dye leakage were most prevalent in the CCoCr group. Fisher exact test demonstrated a statistically significant difference (p = 0.026) between the MCoCr and CCoCr abutments. While CCoCr exhibited the highest failure rate (62.5%), Au gilding demonstrated a trend toward reduced leakage (25% failure rate), though this did not reach statistical significance (p = 0.315). This chromophore analysis represents a viable and objective assessment of IAJ integrity. Full article

Forest recreation sites provide accessible settings for everyday leisure while accommodating multiple, and often competing, uses, making zoning both a central planning challenge and solution. This study advances micro-zoning as a novel, site-scale extension of established recreation zoning concepts, examining how zoning principles can be operationalized within intensively used forest recreation areas. Data were collected from 302 visitors using a structured questionnaire on visit patterns, valued forest attributes, disturbances, and socio-demographic characteristics. Descriptive statistics and tests of association were used to identify needs, disturbances, and recurring combinations of use. The results show that these forests function as everyday recreation spaces for diverse group visits, with high importance placed on peacefulness, shade, cleanliness, natural scenery, and basic infrastructure, alongside frequent reports of disturbance from music, crowding, and litter. Building on these patterns, the study develops a micro-zoning framework that delineates three interpretive planning micro-areas: Drive-in Forest Recreation, representing high-intensity, infrastructure-oriented social use; Low-Intensity Recreation, a moderate-use, low-noise nature-oriented area prioritizing separation from disturbance; and Active Recreation Use, comprising movement-focused routes for walking, running, and cycling. The study illustrates how visitor survey data can guide evidence-based micro-zoning and adapt zoning frameworks to the fine spatial grain of intensively used forest recreation sites. Full article

This study investigates how young children’s geometric reasoning develops through the act of drawing, examining how their eye movements, actions, and verbal explanations interact to reveal emerging structural awareness. Grounded in a developmental framework of structural reasoning, the study extends this model from static visual products to the dynamic processes involved in constructing geometric figures. Using an exploratory qualitative case study design, three children (ages 5.5–7.5) completed line, circle, and rectangle drawing tasks while their gaze and actions were recorded using mobile eye-tracking. Gaze data, video recordings, drawing product, and verbal responses were synchronized and analyzed frame by frame to examine gaze–action coordination. Analysis revealed a progression from partial structural awareness, where gaze remained embedded in action, to structural awareness, where gaze projected multiple steps ahead to coordinate global shape structure. Between these, an intermediate, process-oriented phase was identified, characterized by alternating gaze-in-activity and anticipatory fixations supporting local planning. These fine-grained gaze patterns reveal micro-level transitions in geometric reasoning that are not observable from final drawings alone. The study refines current models of geometric development by revealing how perceptual, representational, and embodied processes dynamically integrate during drawing, offering a more nuanced understanding of early structural reasoning and its implications for teaching geometry. Full article

The implant–abutment connection (IAC) is a critical determinant of the mechanical and biological performance of dental implants. Connection design and insertion torque may influence fatigue resistance, micromovement, and microgap formation, thereby affecting long-term implant success. This in vitro study evaluated a novel conical implant–abutment connection under controlled mechanical loading conditions. Methods: A sequential in vitro protocol was applied. Mechanical testing was conducted according to ISO 14801:2016 and included static and cyclic loading tests of the KS implant system inserted at two different torque values (35 Ncm and 70 Ncm). High-resolution micro-computed tomography (micro-CT) was performed after mechanical loading to evaluate implant–abutment interface integrity, microstructural alterations, and microgap behavior. Results: Static and cyclic loading tests revealed no observable differences between implants inserted at 35 Ncm and 70 Ncm, with all specimens completing the loading protocols without mechanical failure. Micro-CT analysis showed no evidence of microfractures, permanent deformation, or clinically relevant alterations at the implant–abutment interface. A stable and well-sealed connection was observed for both torque values following mechanical loading. Conclusions: Within the limitations of this in vitro study, the investigated conical implant–abutment connection demonstrated stable mechanical performance and preserved interface integrity after static and cyclic loading, regardless of whether implants were placed at 35 Ncm or 70 Ncm. These findings indicate that, under the present experimental conditions, both torque levels were associated with comparable structural integrity and mechanical stability of the investigated implant–abutment connection. This study should be interpreted as a preliminary experimental investigation, designed to provide descriptive and mechanistic insights rather than statistically powered comparative conclusions. Further long-term clinical trials are required to confirm these preliminary results. Full article

The pantograph–catenary system is a critical component of the traction power supply network. Due to hard points on the overhead contact line and vibrations of the pantograph, pantograph–catenary separation may occur, leading to offline DC arc events. To investigate the characteristics of DC arcs generated during pantograph–catenary separation in metro systems, this study constructs a laboratory platform that simulates the offline process and analyzes the electrical characteristics, optical intensity, and arc-burn duration under different electrode separation conditions. First, a DC pantograph–catenary offline arc simulation platform is developed using a contact wire, a carbon-strip pantograph slider, and a linear motor, enabling slider movement in both horizontal and vertical directions. Second, offline discharge experiments are conducted to compare the discharge process and electrical arc characteristics with and without horizontal slider motion. Finally, arc luminosity and burn duration are measured under various electrode separation configurations, and the influence of voltage level, current level, and electrode material is examined. Experimental results reveal a significant polarity effect, where the arc burn duration is notably longer when the contact wire serves as the cathode than when the carbon slider serves as the cathode. At the instant of separation, the high electric field intensity within the micro-gap triggers pronounced “peak phenomena” in both arc resistance and power, accompanied by abrupt voltage surges and transient current dips. Furthermore, the introduction of horizontal motion modulates the arcing process, causing the stable arcing voltage to follow a distinctive trend of a slow increase followed by a gradual decrease, which differs from static separation characteristics. Finally, this study demonstrates that voltage levels exert a more dominant influence on arc luminosity and duration than current levels, while the maintenance voltage of the arc channel remains significantly lower than the air breakdown voltage. Full article

Proximity-oriented urban models, such as the 15-min city, have been promoted to create sustainable, human-centered urban environments that support wellbeing. However, proximity alone does not guarantee accessibility, particularly for persons with disabilities. This paper explores how persons with disabilities experience and navigate Madrid (Spain) and Munich (Germany) under the proximity-oriented policies prism. Drawing on 114 semi-structured interviews (65 in Madrid, 49 in Munich), the study explores how urban form, design features, and environmental conditions shape access, movement, and engagement in public space. Findings reveal that key barriers, such as irregular paving and sidewalk obstructions, limit independence and comfort, while contextual factors such as climate, topography, and local cultural practices further modulate accessibility. Despite proximity, many participants remain reliant on cars instead of public transport due to these micro-scale barriers. By integrating proximity planning, inclusive urban experiences and universal design, this study highlights the need to move from “proximity as distance” to “proximity as accessible experience”, arguing that accessibility must be embedded as a structuring condition of proximity planning. Ultimately, these findings contribute to ongoing debates on sustainable built environments and human wellbeing, highlighting the importance of architectural and urban design in fostering equitable, healthy, and inclusive cities. Full article

This study examines the vocal directivity of singing in Greek across three stylistically diverse genres—operatic/classical, modern/pop, and Byzantine chant—performed under realistic, unconstrained conditions. Directivity data was captured in a hemi-anechoic environment using a 29-microphone hemispherical array, in a setup that allowed singers to make natural, performance-related micro-movements. The applied analysis framework combined sound projection (magnitude of radiated energy across space and frequency) and radiation patterns (normalized spatial distribution) with three established directivity metrics: Horizontal Directivity Index, Front-to-Back Ratio, and Upward-to-Downward Ratio. Results show that while directional shape remains largely consistent across styles and sexes, projection intensity varies systematically as a function of both. Male pop singers exhibit the strongest low-frequency output (125–500 Hz), while female classical and male pop/Byzantine singers display greater frontal focus in the 1–2 kHz range. Classical singers tend toward more balanced projection profiles. Beyond the release of publicly available datasets—including the first directivity measurements of Byzantine chant—this study introduces a structured analysis framework and offers comparative findings that inform vocal science, pedagogy, and spatial audio applications. Full article

The Jurassic lacustrine oil shale in southwest China has become a primary production layer due to its high yield and substantial reserves. However, influenced by the lacustrine environment, the vertical profile of the lacustrine shale reservoir shows alternating deposits of shale and carbonate rock. This complex lithological combination results in significant heterogeneity in reservoir types, reservoir distribution, and internal structure. Currently, research on micro-pore structure and hydrocarbon storage mechanisms in lacustrine shales is insufficient, necessitating the elucidation of their micro-characteristics to support future exploration and development. This research focuses on the Da’anzhai Member of Jurassic Ziliujing Formation. Various techniques—including organic geochemical analysis, X-ray diffraction, physical property testing, gradient centrifugation, and gradient drying NMR monitoring—were employed to investigate the micro-pore structure and fluid storage mechanisms of the lacustrine shale reservoir. The following insights were gained from this research. The organic matter pores (OMP) and inorganic pores (IP) developed within the Da’anzhai lacustrine shale reservoir together create the storage space for shale oil, while micro-fractures further enhance the reservoir’s storage capacity and flow performance. Lacustrine shale oil exists in three storage states: mobile oil, bound oil, and adsorbed oil. Mobile oil is primarily located within the micro-fractures and large pores (greater than 350 nm) of the shale reservoir and is the main target for industrial extraction. Bound oil is mainly found in the meso-pores, micropores, and narrow pore structures between rock grains (30 nm to 350 nm), and, theoretically, could potentially be developed through engineering methods such as hydraulic fracturing. Adsorbed oil, due to its close binding with organic matter and clay mineral surfaces, is difficult to release effectively using conventional techniques. The OM abundance, the mineral composition of lacustrine shale, and the pore structure all influence the storage states of shale oil. While a high TOC value increases the amount of mobile oil, the strong adsorption properties of kerogen and organic matter lead to the accumulation of adsorbed oil, which inhibits oil flow. Clay minerals further restrict oil flow by enhancing adsorption, while brittle minerals facilitate the movement of mobile oil by expanding pore space. Based on fractal geometry theory and multi-scale testing results, the large pores in the Da’anzhai lacustrine shale have a high fractal dimension and exhibit complex shapes. However, as pore complexity increases, the amount of adsorbed oil rises significantly, which in turn reduces the proportion of movable oil. Full article