Search Results (121)

Brush seals using compliant bristle packs can reduce turbomachinery leakage more effectively than conventional labyrinth seals, but their coupled structural and flow behavior makes design difficult. Under large pressure loading, bristles can deflect, lose contact with the rotor, and generate clearance, causing the sharp leakage increase known as blow-out. This study develops a model linking nonlinear bristle deflection, rotor–bristle contact loss, and leakage response. The bristle is treated as an inextensible nonlinear elastic member subjected to distributed pressure loading, backing-plate support, and frictional rotor contact. Contact and separated states are solved iteratively using boundary-value and initial-value solvers. Leakage through the bristle pack is calculated using a random bristle-bed formulation, and leakage through generated clearance is evaluated with an orifice-flow model. The model agrees well with published bristle-deflection predictions. Increasing pressure load reduces normal contact force until lift-off occurs, producing clearance and a sharp rise in leakage. Increasing front-plate free height shifted lift-off from pressure ratio ≈4 to ≈2, while clearance flow contributed up to 36.5% after lift-off. Brush-seal blowout is therefore governed by the transition from rotor–bristle contact to separation. Lower back-plate height can delay blow-out, but hysteresis and durability tradeoffs must be considered. Full article

Digital innovation platform ecosystems can scale rapidly without becoming durable because broad participation does not ensure sustained value circulation. Existing models homogenize complementors, obscuring horizontal coopetition among distinct groups and its interaction with vertical governance. We examine how vertical and horizontal relations shape value-flow architecture and sustainability. Drawing on ecological symbiosis theory, we distinguish a platform orchestrator, technology-extending complementors, and service-integrating complementors. We construct an extended three-actor Lotka–Volterra model and use the Global Value-Flow Symmetry (GV) index and the continuous directional indicator ${\delta }_c$ to assess symmetry and direction. Designed for theory building rather than empirical calibration or testing, the analysis uses no empirical data and compares 35 vertical–horizontal configurations through deterministic simulation and sensitivity analysis. Results show the following: (1) Greater symmetry is associated with higher aggregate maintained output, but vertical backflow direction shapes its distribution; $\mathrm{G}\mathrm{V}$ must therefore be interpreted with ${\delta }_c$. (2) Under complementor-favoring vertical parasitism, horizontal mutualism expands complementor output but intensifies negative vertical backflow, simultaneously increasing aggregate output and reducing platform equilibrium—a cooperation paradox. (3) The same horizontal mutualism yields three focal outcomes across the examined vertical structures: Negative complementor-to-platform effects produce the cooperation paradox, absent effects produce value decoupling, and mutually positive vertical exchange produces systemic resonance. Thus, horizontal cooperation does not necessarily enhance sustainability; its effect depends on whether complementor gains feed back to support platform capability. This study advances platform-ecosystem sustainability research and offers theoretical guidance for optimizing value backflow and cooperative governance. Full article

Western Anatolia is a tectonically and seismically active region shaped by the complex interaction among the Eurasian, African, and Arabian plates. Since the Late Cenozoic, it has been dominated by an extensional tectonic regime. This study investigates the morphotectonic, seismotectonic, and kinematic evolution of the Edremit and Bakırçay basins and their surroundings, located at the intersection zone of the right-lateral strike-slip North Anatolian Fault System (NAFS) and the subduction-zone-driven Aegean Extensional System (AES). Within the scope of this research study, paleostress analyses were conducted using slip data obtained from fault planes, and these data were compared with 240 earthquake focal mechanism solutions reflecting the contemporary seismicity of the region. The findings indicate that both basins underwent a synchronized, two-stage tectonic evolution throughout the Plio-Quaternary period. During the first phase, encompassing the Pliocene, back-arc extensional forces related to slab rollback in the Hellenic subduction zone were dominant, and the main graben-forming processes (NW-SE-trending extension) took place. In the second phase, spanning the Quaternary period, an axis shift occurred as the southern branches of the NAFS reached the region, leading to the development of transtensional pull-apart basin mechanisms dominated by NE-SW-trending extension. Also supported by GPS velocity vectors and paleomagnetic block rotation data, this kinematic model demonstrates that the neotectonic evolution of Northwest Anatolia is governed not only by upper-crustal deformations but also by deep asthenospheric/lithospheric processes, such as slab rollback, lithospheric slab tear, and the NAFS-controlled westward differential escape of the Anatolian block. Full article

Small and medium-sized enterprises (SMEs) have limited resources and governance that might restrict their ability to conduct dynamic cyber risk assessment (DCRA) and maintain effective cyber situational awareness (CSA). This study investigates stakeholders’ perceptions of CSA, DCRA, and AI-enabled cybersecurity to develop a conceptual framework targeted for SMEs. The online survey was cross-sectional, and 302 completed responses were gathered. The valid sample size for the items ranged from 288 to 299. Out of 293 respondents, 54 (18.4%) indicated prior usage of CSA techniques, 21 (7.2%) reported prior use of DCRA tools, and 226 (77.1%) backed AI in the cybersecurity field. The highest rated DCRA requirements were continuous threat updates, identification of attacks and vulnerabilities, and prioritization of alerts based on risk. The highest rated implementation challenges were accuracy, relevance, and integration with current infrastructure. Four multi-item measures had good-to-outstanding internal consistency (α = 0.868–0.926; ω = 0.870–0.929), and parallel analysis supported a single factor for each. Exploratory findings suggested that Information Technology (IT) and cybersecurity professionals had greater familiarity with CSA and DCRA than did leaders and managers. There was a moderate-to-strong positive association between familiarity with CSA and DCRA (ρ = 54). The framework defines AI as a layer of analytical decision support, DCRA as the process of translating changing evidence into updated and prioritized risk information, and CSA as decision-relevant interpretation and use of that information. This framework will help SMEs to improve CSA and will help their leaders to make the right decisions when dealing with cyber threats. Full article

High-altitude regions are known as corridors assisting exchange among communities, and the implementation of economic corridors in these regions provides connections and networks based on two geographical territories. For example, the China–Pakistan Economic Corridor (CPEC), established as an infrastructural development project with wide-reaching socioeconomic and environmental implications, is regarded as a significant driver of regional transformation, with the potential to generate several businesses, build institutional resilience, reduce poverty, foster a circular economy, and create job opportunities. The current study explores the perceptions and attitudes of educated adult residents in selected mountain districts regarding CPEC, which is vital to ensure wide-ranging and sustainable infrastructure development in alignment with the SDG goals, explicitly SDG 4 (Quality Education), SDG 8 (Decent Work and Economic Growth), SDG 9 (Industry, Innovation, and Infrastructure), and SDG 15 (Environmental Protection). Grounded in Social Exchange Theory, Structural Equation Modeling (SEM) was used to assess local perceptions concerning the costs and benefits linked with infrastructural development projects and concentrating on its socioeconomic and environmental outcomes in Gilgit-Baltistan, Pakistan. The questionnaire was self-administered by respondents, who documented their own responses to all items. The researcher remained present throughout data collection to distribute the questionnaires, provide verbal explanations or translations into the local language for specific terms upon request, and collect completed forms; in total, 384 respondents completed the survey. Findings revealed that surveyed educated adult respondents perceived sustainable infrastructural development favorably, particularly regarding anticipated improvements in quality of life, job creation, alleviating poverty, and the current education system, with 59.9%, 53.1%, 53.1% and 41.7% agreement, respectively. Respondents also expressed concerns about environmental protection, such as health and safety, environmental risks, and construction/transportation-related pollution at 39.8%, 37.5% and 36.7%, respectively. Backed up by SEM direct path analysis, which showed significant positive relationships between infrastructural development and educational development (H1: β = 0.439), quality of life (H2: β = 0.638), job opportunities (H3: β = 0.603), poverty alleviation (H4: β = 0.534), and environmental protection (H5: β = 0.267). Thus, all hypotheses H1-H5 were supported. This study recommends that officials and policymakers promote stakeholder investment for regional sustainability transitions, formulate regional environmental policies and governance for sustainable development to enhance the benefits of CPEC. Full article

This paper develops a literature-grounded review on connecting circular economy (CE) principles and urban mobility to examine how smart city transportation can be reshaped through durable design, reuse, service-based models, and materials stewardship. A structured review of indexed documents (2010–April 2026) from Scopus and Web of Science identified a set of papers that were screened, thematically grouped into six clusters (design, digital infrastructures, shared mobility, materials management, social inclusion, decision support), and synthesized via textual analysis to generate an integrative, evidence-based conceptual framework, identify empirical and methodological gaps, and propose policy-relevant research priorities informed by the identified topics. The literature documents CE interventions and analytical methods that can lower embodied impacts, raise asset utilization, and recover secondary materials when backed by clear public policies, coordinated governance, and digital platforms. Key limitations include fragmented governance, optimistic recovery rate assumptions, limited integration of life cycle analyses, and weak empirical evidence linking participatory processes to measurable outcomes. The findings are relevant to researchers, planners, policymakers, and practitioners, and indicate that operationalizing circular approaches in urban mobility requires cross-sectoral policy alignment, data governance, financing reform, inclusive stakeholder engagement, interoperable platforms, and longitudinal place-based pilots with multi-metric monitoring aligned with the Sustainable Development Goals. Full article

The unsteady buzz characteristics of a dorsal supersonic bump inlet for a flying-wing configuration are investigated using wind-tunnel tests and three-dimensional unsteady numerical simulations. This study focuses on off-design operation at a freestream Mach number of 1.8, with particular attention to the effects of angle of attack and downstream throttling on shock motion, pressure oscillation, and inlet stability. Wind-tunnel measurements show that the onset and development of buzz are highly sensitive to angle of attack. At high angles of attack, pressure oscillations first appear near the inlet compression surface and subsequently develop into large-amplitude fluctuations at the aerodynamic interface plane. The dominant experimental buzz frequency is approximately 60–70 Hz, and the numerical prediction of 71 Hz agrees well with the measured dominant frequency of 66 Hz. The simulations further reveal a strongly three-dimensional buzz cycle in which asymmetric separation over the bump, spanwise accumulation and discharge of low-energy flow, and alternating inlet blockage and recovery govern the large-amplitude shock excursion. The oscillatory flow field is dominated by shock–system expulsion and ingestion on the spanwise side with stronger back-pressure tolerance, accompanied by the formation of strong and weak shear layers during different stages of the cycle. These results provide insight into the buzz mechanism of dorsal bump inlets and support the assessment of starting performance and stable operating limits for supersonic inlets integrated with flying-wing configurations. Full article

Large language models (LLMs) are increasingly discussed in digital government research, but existing studies remain fragmented across application opportunities, technical performance, and governance risks, with limited synthesis of how they support service provision within digital government service processes. Using the concept of interpretive support, this study examines: (1) what forms of interpretive support LLMs provide; (2) what task- and service-level effects are reported; and (3) what governance conditions shape responsible integration. Drawing on a socio-technical systems perspective, the study conducts a PRISMA-informed systematic review and thematic synthesis of 60 studies from the Web of Science Core Collection and Scopus. The findings show a shift from stand-alone question answering to broader forms of interpretive support, including rule explanation, service navigation, complaint interpretation, issue routing, and back-office knowledge structuring. The strongest evidence concerns efficiency, responsiveness, and accessibility, whereas claims about trust, accountability, and wider public value remain less well supported. The review concludes that public value is conditional rather than automatic, depending on reliability, legal boundaries, responsibility allocation, data security and privacy, and organizational capacity. Future research should examine whether these service-level gains persist in routine service environments and how governance mechanisms affect service quality, equity, and accountability. Full article

Against the background of China’s “dual carbon” goals and the continued advancement of the green and low-carbon transformation of resource-based industries, resource-based enterprises urgently need to rely on green innovation to overcome development constraints characterized by high resource dependence, strong environmental pressures, and mounting transformation challenges. Patient capital, with its long-term orientation, stable support, and risk-sharing characteristics, can provide sustained financial backing and governance support for green innovation in resource-based enterprises; however, its underlying mechanism remains to be further explored. Drawing on patient capital theory, this study constructs a “capital–ESG–innovation” analytical framework to examine the impact of patient capital on green innovation in resource-based enterprises and its mechanism of action. Using Chinese A-share listed resource-based enterprises from 2014 to 2023 as the research sample, this study measures patient capital from two dimensions, namely stable equity and relational debt, and conducts empirical analysis through panel regression and multiple robustness tests. The results show that patient capital significantly promotes green innovation in resource-based enterprises, with both relational debt and stable equity playing positive roles. Mechanism tests reveal that ESG performance serves as an important mediating channel through which patient capital promotes green innovation. Further analysis indicates that the level of regional marketization strengthens the green innovation effect of patient capital, and this effect is more pronounced in large enterprises, enterprises subject to stronger media supervision, and enterprises whose executives have higher green cognition. This study enriches the literature on the relationship between patient capital and green innovation and provides empirical evidence for cultivating long-term capital and promoting the green and low-carbon transformation of resource-based enterprises. Full article

This study examines whether environmental, social, and governance (ESG) performance reduces credit risk in Gulf Cooperation Council (GCC) banks over 2014–2025, and whether this relationship differs between Islamic and conventional banks. Using loan-loss provision (LLP) ratios as the primary credit risk proxy, we estimate two-way fixed-effects panel regressions and, as the primary specification, a two-step System GMM estimator for 43 banks across six GCC countries (258 bank-year observations). Our results are threefold. First, accounting for profit persistence and endogenous capital accumulation through System GMM reveals a significant negative aggregate ESG–credit risk relationship absent from static fixed-effects estimates, directly supporting the credit risk reduction hypothesis. Second, pillar decomposition identifies the social score as the primary driver, while governance and environmental scores are individually insignificant in the full sample. Third, split-sample GMM estimates reveal that Islamic bank credit risk dynamics are structurally distinct: profitability (ROA) suppresses provisioning approximately 1.2 times more powerfully than in conventional banks, loan intensity disciplines rather than amplifies credit risk under Sharia asset-backed financing, and lagged provisioning exhibits a mean-reversion pattern unique to the profit-and-loss sharing model. Full article

Trustworthy digital credential management is increasingly important in LMS-connected higher-education information systems, yet institutions still lack controlled implementation-oriented evidence on how cloud-native service decomposition and blockchain-backed trust services influence deployment performance. This study develops and evaluates a cloud-native architecture that combines containerized microservices with Hyperledger Fabric-based permissioned ledger services and a Polygon-linked public-chain anchoring path for credential issuance, learning-record verification, and record validation. Unlike largely conceptual prior work, it benchmarks four functionally aligned deployment paths in a unified Kubernetes-managed testbed: a monolithic baseline, a microservices-only baseline, a Hyperledger Fabric-integrated variant, and a Polygon-linked anchoring path. The credential-service paths were evaluated under stepped workloads from 1000 to 20,000 scheduled virtual users. Evaluation focused on service-path latency, throughput, tamper-detection accuracy, and resource utilization. The microservices-only architecture achieved the lowest baseline latency (182 ms), Hyperledger Fabric maintained stable response times for trusted institutional workflows (352 ms at baseline and 485 ms at 20,000 virtual users), and the Polygon-linked anchoring path reached the highest observed service-path throughput (228 TPS) in the tested prototype. Both blockchain-integrated variants detected tampered credentials in all successfully processed tamper cases. Overall, the results show that cloud-native decomposition and ledger-backed trust and anchoring can support scalable and trustworthy credential services when platform choice aligns with institutional governance scope, verification audience, and deployment constraints. Full article

Background and Objectives: Patient safety at hospital interfaces is shaped by organisational fragility, ethical obligations, and anticipated legal exposure. Reporting, disclosure, and speaking up have been studied separately, yet the way these pressures converge in ordinary hospital work remains insufficiently described. Materials and Methods: We conducted a qualitative study in a public hospital in Romania using semi-structured episodic interviews and the critical incident technique. Twelve clinicians participated: six nurses and six physicians working in intensive care, emergency medicine, general surgery, paediatrics, oncology day care, anaesthesia, obstetrics, and internal medicine/cardiology. Interviews were audio-recorded, transcribed verbatim in Romanian, anonymised, and analysed with the framework method from a critical realist perspective. A secondary cross-case coding of all 12 episodes was used for descriptive analytic displays. Results: Four mechanisms organised the material. First, local stop rules and cross-checks created temporary stability at fragile interfaces such as high-alert medication, patient identification, specimen labelling, and transfer documentation. Second, consent and confidentiality were repeatedly compressed by urgency, compromised capacity, public space, and family pressure; legitimacy depended on explicit reasoning rather than documentary completion alone. Third, speaking-up and near-miss reporting were governed by protocol-backed legitimacy, leader response, and the informal cost of interruption. Formal incident reporting was present in one episode, partial in one, and absent in 10. Fourth, documentation and disclosure redistributed accountability. Notes that recorded reasoning supported continuity of care, whereas protective opacity concealed near misses, infrastructural weakness, and interactional pressure. Documentation or disclosure pressure appeared in all 12 episodes. Conclusions: Safety in everyday hospital work was assembled through local barriers, moral triage, and selective visibility. Interface redesign, protected near-miss reporting, psychologically safe escalation, and structured support for urgent consent and post-incident communication would make transparent safety work more sustainable. Trustworthiness was strengthened through reflexive memoing by the physician-interviewer, an audit trail of coding decisions, comparison across professional groups, active attention to negative cases, and iterative assessment of meaning saturation at the level of explanatory mechanisms. Full article

This manuscript creates a framework for decision support based on green urbanism to direct the sustainable development of Gamasa, an Egyptian seaside city. The paper aims to convert the concepts of green urbanism into a multi-criteria evaluation that can support strategic urban development and prioritize spatial interventions. Sustainable mobility, green and blue infrastructure, energy and resource efficiency, urban form and density, social livability and public space quality, and governance and implementation feasibility are the six dimensions that are defined. These dimensions are derived from international sustainability literature and tailored to Gamasa’s particular challenges. The study’s methodology combines a multi-criteria decision-making approach based on the AHP with spatial analysis of land use, street hierarchy, building shape, and green space distribution. Weights for these dimensions are determined by expert-based pairwise comparisons, which are backed by a SWOT analysis. To prioritize priority zones for green transformation, the weighted framework is applied to four important urban areas: residential districts, a large urban park, the waterfront, and the main urban corridor. The top priorities, according to the results, are climate-responsive coastal design, increased green and blue infrastructure, and sustainable transportation. For quickly urbanizing coastal cities, the method demonstrates how the AHP operationalizes green urbanism into quantifiable, context-sensitive goals. Full article

Sustainable air quality governance requires robust monitoring and updated air quality management plans (AQMPs) to translate legislation into meaningful environmental and health protection. The Highveld Priority Area (HPA), which was declared South Africa’s second National Air Pollution Priority Area in 2007, includes the Ekurhuleni Metropolitan Municipality (EMM), where AQMPs are outdated and long-term chemical characterization data remain limited. This study provides baseline evidence to support AQMP revision by characterizing PM_2.5 mass concentrations and chemical composition in a residential area of Kempton Park within the EMM and HPA. A total of 57 24 h PM_2.5 samples were collected every sixth day from May 2021 to April 2022. Concentrations ranged from 0.9 to 32 µg/m³ (annual mean 10 µg/m³), exceeding the WHO annual guideline (5 µg/m³) but remaining below the South African standard (20 µg/m³). The daily WHO guideline (15 µg/m³) was exceeded on 13 days. PM_2.5, black carbon and organic carbon peaked during winter and spring, consistent with enhanced atmospheric stability and combustion emissions, while elements Br, Fe, K, S, Si and Sr exhibited seasonal variability. Principal component analysis and enrichment factor assessment distinguished crustal sources (Si, Ca, Fe, Ti) from enriched anthropogenic elements (S, Zn, Br, U), indicating contributions from combustion, industrial activities and mining. Correlation patterns and 72 h back-trajectory analysis further demonstrated shared sources and significant regional transport influences. These findings highlight the combined role of local emissions, meteorology and long-range transport, providing locally relevant evidence to inform sustainable air quality management within the EMM and HPA. Full article

Intervertebral disk pathology, including disk herniation and degeneration, is a major contributor to chronic low back pain, and when conservative treatment fails, surgical management often involves discectomy-based procedures that leave residual annulus fibrosus (AF) defects associated with reherniation and progressive degeneration. These limitations have motivated interest in regenerative strategies using biomaterial scaffolds; however, reproducing the hierarchical, angle-ply architecture of the AF remains challenging. Here, we present a single-step extrusion-based 3D-printing approach to fabricate polycaprolactone (PCL) scaffolds with aligned microscale surface grooves that promote AF-like organization. Patterned nozzles with circumferential peaks generated uniaxial concave microgrooves (10–17 µm wide) directly during printing, enabling formation of multilamellar angle-ply constructs. Human bone marrow-derived mesenchymal stem cells cultured on patterned scaffolds aligned longitudinally within concave grooves, forming end-to-end arrays that guided extracellular matrix deposition. Gene expression analysis showed that topographical cues governed cellular organization without significantly altering gene expression profiles, while TGF-β3 supplementation upregulated outer AF-associated markers, including COL1, COL12, SFRP2, MKX, MCAM, and SCX. TAGLN expression increased specifically on patterned scaffolds in the absence of TGF-β3, indicating an association between microgroove-guided cellular organization and TAGLN expression, warranting further investigation into potential tension-related mechanisms. This novel single-step extrusion-printing approach leverages custom nozzle geometry to impart concave microgrooves, facilitating scalable fabrication of multilamellar angle-ply scaffolds that induce aligned cellular organization and support potential applications in annulus fibrosus repair, as well as mechanobiological studies of anisotropic musculoskeletal tissues. Full article