Search Results (6,785)

The phasing out of high-GWP refrigerants and the growing diversity of working fluids used across heat pumps, refrigeration systems, and closed-cycle power applications have made drop-in fluid replacement a question of significant practical interest. Centrifugal compressors are designed around the thermophysical properties of a specific fluid, and the performance penalty is incurred when working fluid is replaced without redesigning the impeller. This study presents a CFD comparison of direct drop-in fluid replacement in a fixed geometry centrifugal compression system. Eight working fluids that span the property range relevant to current drop-in substitutions are evaluated: air, nitrogen, argon, carbon dioxide, R22, R134a, R1234yf, and R1234ze(E). A reference centrifugal impeller was reconstructed in ANSYS BladeGen, meshed in ANSYS TurboGrid using the Automatic Topology and Meshing method, and simulated in ANSYS CFX (2024 R2) as a single periodic passage with Frozen Rotor interfaces and Spalart–Allmaras turbulence closure. Performance maps were generated for each fluid across a range of rotational speeds and mass flow rates, with a common inlet reference condition applied across all cases to isolate the influence of fluid properties from an inlet state. The resulting dataset enables a like-for-like comparison of pressure ratio, efficiency, and shaft power requirement, providing a basis for assessing the aerodynamic implications of drop-in fluid substitution in centrifugal compression systems. Air, nitrogen, argon and carbon dioxide achieved similar peak efficiencies (~88%) and comparable pressure ratios (PR), indicating they can be used as drop-in substitutes without performance loss. Refrigerants R1234yf and R1234ze(E) matched R134a in efficiency (peak ~90%) while offering higher pressure ratios and significantly lower power requirements at peak efficiency. At 20,000 RPM and a mass flow rate of 2 kg/s, compared to a PR of 1.45 for air, nitrogen, carbon dioxide and argon achieved PRs of 1.4, 1.9 and 2.4, respectively. At the same settings, R134a and R1234 refrigerants reached PRs of 5 and 6, respectively. The power requirement was ~8 × 10⁴ W for air and similar fluids, and ~11 × 10⁴ W for refrigerants. Full article

This paper develops a unified qualitative framework for four classes of Liouville–Caputo fractional difference equations arising from different combinations of fractional sums and integer-order differences. Based on the equivalence between initial/final value problems and Volterra-type summation equations, sufficient conditions for the existence and uniqueness of solutions are established by applying the Banach contraction mapping principle together with refined combinatorial estimates. Furthermore, the continuous dependence of solutions on prescribed initial or final data is investigated. By deriving explicit error estimates through a discrete fractional Gronwall-type inequality, we prove that Lipschitz solutions depend continuously on perturbations of boundary data. Numerical experiments for a representative case are presented to verify the theoretical results, including the influence of the fractional order and the sensitivity with respect to boundary data, while additional examples illustrate the applicability of the framework. The obtained results extend the unified discrete fractional calculus framework by providing a rigorous well-posedness analysis and offering a theoretical foundation for further applications of discrete fractional models with memory effects and diverse boundary conditions. Full article

Maternal obesity and a Western diet high in fat and sugars are increasing worldwide and may contribute to rising neurodevelopmental and neurobehavioral disorders in offspring. Both human and animal studies link these factors to adverse outcomes. However, the cellular mechanisms driving altered early-life neurogenesis, particularly in the hippocampus, remain unclear. To assess fructose effects on neural stem cell (NSC) differentiation and neuronal morphology, hippocampal NSCs from E12.5 C57BL/6 mouse embryos were cultured and treated with fructose (8.75 or 12.5 mM) for 7 days. Neuronal and astrocyte populations, along with neuronal morphology, were analyzed by immunofluorescence, and protein expression was assessed by Western blot. Fructose treatment significantly reduced neuronal and increased astrocyte counts, leading to a decreased neuron-to-astrocyte ratio compared to controls. These findings were supported by decreased MAP2 (neuronal) and increased GFAP (astrocyte) protein expression. Furthermore, fructose also significantly reduced neurite lengths without affecting neurite number. Morphological analysis revealed decreased soma size, reduced area/perimeter, and altered soma area-to-perimeter ratios, indicating impaired structural integrity. Thus, fructose exposure shifts NSC differentiation toward an astroglial lineage while suppressing neuronal development and impairs neuronal growth and structural complexity. Future studies are necessary to determine the influence of these cellular changes on synaptic plasticity and learning, as well as memory. Full article

Space-time adaptive processing (STAP) is regarded as a highly effective approach for clutter mitigation in airborne radar applications. However, in practical range-ambiguous scenarios, the clutter suppression performance of traditional STAP algorithms can be severely degraded. Element-pulse coding (EPC) radar introduces extra controllable freedoms by assigning frequency offsets among array elements, which provides a promising means to cope with the influence of range ambiguity. On this basis, EPC-assisted STAP techniques have attracted increasing attention. Even so, the large number of adaptive degrees of freedom (DoFs) required by EPC-STAP makes its performance highly dependent on sufficient training snapshots, and a noticeable degradation may occur when only limited snapshots are available. To overcome this limitation, this study focuses on reduced-dimension (RD) STAP for airborne EPC radar under range-ambiguous conditions and develops an efficient reduced-dimension EPC-STAP scheme. Specifically, the received signal model of the airborne EPC-STAP system is first formulated to characterize the data structure. Subsequently, a tailored linear mapping matrix is constructed to compress the original high-dimensional observation space. The resulting RD-EPC-STAP processor is then obtained according to the minimum variance distortionless response principle using the transformed lower-dimensional data. Numerical experiments verify that the proposed algorithm provides improved clutter rejection capability while retaining strong tolerance to array gain and phase errors. Full article

Exhibition layouts in museums strongly influence visitors’ learning and viewing experiences, yet their evaluation often relies on curators’ subjective judgments. This study aims to provide objective behavioral data through visitor flow analysis to support evidence-based exhibition design. Single-board computers installed in the museum exhibition rooms serve as sensors to detect humans in captured images using machine learning. Detected positions are projected onto a floor map using a homography transformation to reconstruct visitors’ spatiotemporal behavior. The proposed system enables server-side real-time analysis and visualization, allowing curators to quickly and objectively understand visitor movement patterns. Full article

Background: Falls in older adults are a major public health and rehabilitation concern and may reflect interacting chronic disease-related mechanisms rather than diagnostic labels alone. Type 2 diabetes mellitus (T2DM), hypertension (HTN), and osteoarthritis (OA) are common in later life and may influence fall vulnerability through sensory, vascular, musculoskeletal, cognitive, medication-related, and functional pathways. This scoping review aimed to map mechanism-oriented evidence linking T2DM, HTN, and OA to falls and fall-related outcomes in older adults. Methods: A scoping review was conducted in accordance with established scoping review methodology and PRISMA-ScR guidance. PubMed, Web of Science, and Embase were searched for English-language studies published from 2016 to 2026; the final search was conducted on 15 April 2026. Evidence was charted in a structured table and synthesised descriptively and thematically across disease-specific and shared mechanism domains. Results: A total of 151 studies were included. The evidence was organised into T2DM-related sensory-neural, gait and balance, vestibular/visual-cognitive, strength-related, and glycaemic or medication-related mechanisms; HTN-related haemodynamic, cerebral perfusion, dizziness/syncope, and medication-related mechanisms; and OA-related pain, proprioceptive, strength-related, gait and balance, psychological, and compensatory-control mechanisms. Shared pathways included frailty, multimorbidity, polypharmacy, pain burden, cognitive impairment, sleep disturbance, ADL decline, dizziness, and reduced physical function. Conclusions: Falls in older adults with T2DM, HTN, OA, or multimorbidity may be better understood through interacting disease-specific and shared mechanisms than through diagnostic labels alone. Future longitudinal and multimorbidity-specific studies using standardised fall ascertainment are needed to test these pathways more directly. Full article

Monitoring the spatial distribution of oyster reefs in an accurate, efficient, and flexible manner is crucial for assessing changes in nearshore fishery habitat environments. However, traditional optical remote sensing methods are often affected by illumination variation, tidal fluctuation, and spectral confusion in complex intertidal environments. An automated extraction framework based on the SAM (Segment Anything Model) using UAV (Unmanned Aerial Vehicle) DOM (Digital Orthophoto Map) imagery is proposed to achieve high-precision oyster reef identification and area estimation. Multi-resolution UAV imagery was processed, and key SAM parameters were systematically optimized under different illumination conditions. The results show that spatial resolution significantly influences segmentation accuracy, and appropriate resolution selection improves both stability and reliability. Based on UAV data acquired in 2025, the total oyster reef area in the study region was estimated to be 2.24 ha. After parameter optimization, segmentation accuracy improved from 93.22% to 97.61% in illuminated areas and from 93.30% to 96.67% in shaded areas. The proposed method demonstrates strong robustness under varying environmental conditions and effectively enhances boundary detection accuracy. A scalable and reliable approach is provided for coastal habitat monitoring and offers new insights into automated object extraction in complex remote sensing imagery. Full article

Pollen data obtained from aerobiological monitoring are utilized in various fields of application but require statistical processing. In this study, airborne pollen data from the Rome aerobiological monitoring stations (San Pietro Hospital and Tor Vergata), covering the period 1997–2025, were analyzed, with a specific focus on an Ambrosia pollen episode occurring on 11–12 September 2009. Many studies have employed descriptive statistical methods or predictive models. Among these, the HYSPLIT model was employed in a case study to verify whether the elevated levels of ragweed pollen recorded on 11–12 September 2009 in Rome were attributed to long-distance transport, and to determine the possible source areas through back-trajectories. The relationships between pollen concentrations, distribution maps of Ambrosia spp. individuals, transport conditions, and meteorological conditions were examined. The combination of these tools appears to confirm that the presence of Ambrosia pollen is the result of long-distance transport. To complement the modeling analysis, backward trajectories were computed using the HYSPLIT model with a 48 h duration at three altitudes (0, 100, and 1500 m above sea level) to evaluate the influence of planetary boundary layer dynamics on the transport pathways. Despite being an excellent tool, the use of HYSPLIT in Italy could present some critical issues due to the terrain topography, which affects the calculation of altitude levels and introduces uncertainties in trajectory reconstruction. New techniques are emerging daily, leading to increasingly precise forecasts. Nevertheless, an increase in aerobiological sampling sites with adequate regulation would represent a sound starting point for standardizing intervention strategies. Full article

To address the difficulty of effectively sensing weakly distorted electric fields generated during the early stage of insulation degradation in power equipment, this paper proposes a miniaturized high-sensitivity multilayer flexible electric field sensor optimized using an improved GOOSE algorithm. First, based on the electric field coupling mechanism, the enhancement effect of the flexible arc-shaped structure on local distorted electric fields is analyzed, and an equivalent model that discretizes the flexible curved surface into parallel-plate micro-elements is established. Furthermore, a multilayer sensor equivalent circuit model considering the effects of parasitic capacitance and conductive ink electrode resistance is developed, and the relationship between sensor sensitivity and structural parameters is derived. Subsequently, an electric field–circuit-coupled simulation model is established in COMSOL Multiphysics to systematically investigate the influence of parameters such as electrode layer number, electrode thickness, dielectric layer thickness, and electrode side length on the output response. The results show that the multilayer structure can effectively improve the equivalent sensing capacitance and electric field coupling capability, while the electrode thickness and dielectric layer thickness exhibit significant nonlinear effects on the output voltage. To achieve the coordinated optimization of high sensitivity and miniaturization, Tent chaotic mapping initialization and nonlinear dynamic adaptive inertia weight are introduced to improve the traditional GOOSE algorithm, and a multi-objective optimization model is constructed with the objectives of maximizing the output voltage and minimizing the electrode area. The optimization results indicate that the improved GOOSE algorithm achieves faster convergence and better optimization stability. Among the Pareto solution sets with different electrode layer numbers, the seven-layer structure exhibits the best size–performance trade-off. The final optimized design achieves an electrode area of only 1.746 mm² and an output voltage of 2.565 × 10⁻⁶ V. These results demonstrate that the proposed multilayer flexible structure and improved GOOSE optimization method can significantly enhance the response capability to weak electric fields while maintaining device miniaturization, providing a new sensor design concept and optimization approach for non-contact detection of early-stage insulation degradation in power equipment. Full article

Family-centred approaches are being increasingly recognized as integral to inclusive mental health care. Although substantial evidence-based exists for specific interventions particularly family intervention for psychosis, there is no synthesis that maps how family-centred approaches are conceptualized, implemented, and linked to inclusivity across diagnoses, service contexts, and levels of evidence. Existing reviews are largely disorder-specific or outcome-focused and do not examine family-centred care as a system-level strategy for inclusive practice. This scoping review aimed to map and synthesize the existing literature on family-centred approaches used to promote inclusive mental health care for individuals with psychiatric disorders. This review followed the Joanna Briggs Institute (JBI) methodology for scoping reviews and the PRISMA-ScR reporting guidelines. Searches were conducted in PubMed, PsycINFO, CINAHL, Scopus, Embase, and Web of Science for English-language empirical studies published between 2000 and 2025. Studies involving individuals with psychiatric disorders and any form of family-centred, family-focused, or family-inclusive approach were eligible. Data were charted and analyzed thematically to map intervention types, reported outcomes, and implementation influences; the review did not evaluate intervention effectiveness. Twenty-four studies met the inclusion criteria. Only five themes emerged from this study. Across the literature, family involvement was associated with improved engagement, enhanced communication, and increased caregiver competence. Psychoeducation featured prominently in evidence-based interventions, while newer models emphasized shared decision-making and service co-production. Family-centred approaches are conceptualized in diverse ways across mental health services and are commonly linked to more inclusive and collaborative care. However, the strength of evidence varies substantially between intervention types. This review clarified how family-centred practices are situated across levels of evidence and service contexts, highlighting the need for greater precision in distinguishing established interventions from emerging practices and for system-level strategies to support consistent, culturally responsive family inclusion. Full article

Micro-Newton cold-gas thrusters are promising actuators for precision space missions, but their performance is strongly influenced by the integrated head architecture. This study presents the design, fabrication, and experimental validation of a piezoelectrically controlled cold-gas microthruster head for space-based gravitational-wave detection missions. The proposed head integrates a cone-needle throttle, a micro-orifice interface, and a downstream micro-nozzle, thereby converting actuator displacement into a regulated mass flow and ultimately into thrust. One-dimensional theory was first used for preliminary sizing, and Direct Simulation Monte Carlo (DSMC) analysis of the complete throttle-nozzle geometry was then applied to determine the final design parameters under rarefied-flow conditions. The selected design uses a throat radius of 29 μm and a needle half-angle of 10 degrees. Following fabrication and structural characterization, the integrated device was validated through mass-flow calibration and vacuum thrust testing. The experimental results show that the pressure-decay-based calibration provides a consistent mapping between actuation command, calibrated flow rate, and thrust output. The measured flow–thrust relation preserves the high linearity predicted by simulation, while the experimentally evaluated specific impulse meets the specified design target over the tested range. In addition, thrust-resolution testing at a baseline thrust of approximately 98.4 micro-Newton demonstrates a minimum resolvable step of 50 nano-Newton, and the measured thrust-noise amplitude spectral density remains below 0.07 micro-Newton/sqrt(Hz) over the 10 mHz–1 Hz band for the tested thrust levels. These results support the feasibility of the proposed integrated cold-gas microthruster head and its device-level validation approach for future space-based gravitational-wave detection applications. Full article

AI-based multi-hazard susceptibility mapping has become an important approach for identifying slope-instability hazards over large areas. However, in multi-hazard modeling, negative samples do not have a consistent stable meaning across hazard types: a background unit that is stable for one hazard may correspond to a potentially susceptible environment for another. Existing studies mainly focus on model optimization and accuracy improvement, but pay limited attention to task-level label confusion and background-sample mismatch caused by this issue. To address this gap, this study proposes a task-specific negative sample selection method based on the feature-space distribution of hazard-specific positive samples. Specifically, for each hazard type, the method uses its positive-sample centroid as a reference to rank the shared candidate background pool by feature-space distance. Rather than selecting only hard or easy negatives, it combines hard negatives closer to the centroid, easy negatives farther from it, and randomly supplemented background units to improve diversity. Taking the Minjiang River Basin in southeastern coastal China as the study area, the proposed method was compared with five benchmark strategies—random sampling, easy negative sampling, hard negative sampling, outside-buffer sampling, and buffer-ring sampling—using random forest (RF), boosted regression tree (BRT), multilayer perceptron (MLP), support vector machine (SVM), and logistic regression (LR). The results show that the dataset constructed using the proposed method improves the overall classification performance of the models, with average improvements of 14.47% and 12.25% in AUC and F1-score, respectively. The corresponding susceptibility maps also show the highest spatial screening efficiency, with the top 10% susceptible areas capturing 39.26% of historical hazard events, and only 27.06% of slope units were required to cover 80% of the hazards. In addition, this study further discusses the influence of hazard-specific adaptability on the feature-space distribution of negative samples, as well as the relationships among negative-sample selection strategies, classification performance, and study area-wide susceptibility-map quality. This study provides a new method for constructing reliable negative samples in regional multi-hazard susceptibility mapping of slope-instability hazards. Full article

Innovation ecosystems are recognized as drivers of regional development and technological transformation, yet empirical studies remain concentrated in metropolitan areas, limiting the understanding of emerging agroindustrial territories. This study examines the innovation ecosystem of Rio Verde (Brazil), highlighting how structural configurations and functional asymmetries influence collaboration and distributed innovation outcomes. Grounded in the Regional Innovation System perspective and the Six-Helix model, an exploratory survey was conducted with 41 actors through a digital mapping platform. Results reveal institutional diversity and strong willingness to collaborate, but innovation capabilities and outputs remain concentrated in a few central organizations, while funding and coordination mechanisms are weak. The study refines the concept of the collaboration paradox—high engagement without broad diffusion of results—and demonstrates the methodological value of combining digital ecosystem mapping with the Six-Helix framework. Practically, it suggests that regional policies should move beyond stimulating collaboration to prioritize funding, institutional coordination, and the diffusion of innovation capabilities across emerging agroindustrial ecosystems. Full article

Background/Objectives: Among the most common medical conditions of pregnancy, nausea and vomiting of pregnancy (NVP) and its severe form hyperemesis gravidarum (HG) represent a clinically significant and increasingly researched area of maternal health. However, the global evolution, structural organization, and thematic development of this literature remain insufficiently characterized. This bibliometric study maps five decades of global research on therapeutic and supportive interventions for NVP and HG. Methods: Web of Science Core Collection records were searched on 10 May 2026, restricted to English-language articles and reviews published up to 2025, and deduplicated to 1182 unique documents. A secondary thematic filter was subsequently applied to generate a refined obstetric subset for the country collaboration, keyword co-occurrence, and thematic evolution analyses. Bibliometric performance, collaboration networks, source impact, institutional output, PELT-based changepoint detection, metadata completeness, keyword co-occurrence, and thematic evolution were analyzed using VOSviewer, Bibliometrix/Biblioshiny, and custom Python scripts. Results: Publication output increased markedly after 2010 and reached its maximum in 2025. PELT sensitivity analysis localized the principal transitions to the mid-1990s and early 2010s, informing three broad analytical macroperiods: 1975–1994, 1995–2009, and 2010–2025. The United States dominated cumulative output and collaboration intensity, while Canada, England, Australia, Italy, Germany, and China showed substantial scientific influence. Core publication venues were concentrated in obstetrics, gynecology, reproductive safety, and pregnancy-focused clinical medicine. Keyword and thematic analyses showed a transition from early vomiting, Bendectin, exposure, and pregnancy-safety concerns toward pharmacological treatment, complementary interventions, controlled clinical evaluation, maternal–fetal outcomes, and supportive management. Metadata-completeness analysis identified a major pre-1991 indexing discontinuity, requiring caution when interpreting long-range keyword-based trends. Conclusions: These findings outline the trajectory of the field and highlight priorities for future research, including stronger comparative evidence for pharmacological, complementary, and supportive-care strategies, broader international collaboration, and prospective studies to strengthen the evidence base for managing NVP and HG. Full article

This study presents an analytical elastic solution using the complex variable approach to determine the soil disturbance surrounding a shallow rectangular tunnel, taking into account the effect of gravity and considering the influence of grouting pressure applied at the tunnel boundary. A theoretical calculation model is first established by applying stress boundary conditions along the tunnel boundary. To handle the geometric complexity of the rectangular cavity, a conformal mapping function suitable for non-circular opening is adopted. This function maps the original half-infinite region with a rectangular cavity onto an annulus in the transformed plane, thereby converting the irregular cavity problem into a more tractable configuration. The boundary conditions at the ground surface and the tunnel interface are then addressed using Fourier series expansion. By solving these series-expanded equations, all unknown coefficients of the analytical functions are determined, leading to an analytical elastic solution for soil disturbance. Numerical verification validates the accuracy of the proposed approach. Moreover, parametric studies are conducted to evaluate the effects of soil mechanical properties and tunnel geometry on the soil disturbance. The findings offer a valuable reference for future investigations into construction-related issues associated with rectangular tunnels. Full article