Search Results (3,287)

Complex narrow-channel reservoirs are strongly constrained by depositional architecture, resulting in highly nonuniform areal waterflood sweep, and pronounced water-cut variations among different channel types. These characteristics pose substantial challenges to stabilizing oil production and controlling water cut at high water-cut stages. To elucidate how narrow-channel planform architecture controls waterflood sweep, gel-assisted flow-field regulation by heterogeneous-phase composite flooding (HPCF), and remaining-oil mobilization, three representative configurations were reproduced in two-dimensional visual physical models. Sequential waterflood–HPCF–post-waterflood experiments were conducted, and time-lapse images and dynamic production data were integrated to characterize sweep evolution and remaining-oil mobilization across displacement stages. The results demonstrate that narrow-channel architecture exerts primary control on preferential flow-path development, gel migration and retention, spatial fluid redistribution, and displacement performance. During waterflooding, injected water preferentially migrated through high-permeability zones along channel centerlines, leaving channel margins, branch termini, and poorly connected regions insufficiently swept. After HPCF injection, the gel-containing composite system preferentially entered the established dominant flow paths. Gel retention and accumulation selectively increased flow resistance in these pathways, while mobility control induced subsequent fluids to divert toward bypassed regions, thereby enlarging the macroscopic swept volume and improving local displacement efficiency. A low injection rate promoted sustained gel-assisted flow diversion within bifurcated channels, whereas a high injection rate facilitated gel-slug propagation against the geometric constraints of highly sinuous channels and expanded its spatial coverage. Compared with waterflooding alone, HPCF increased the ultimate oil recovery of the three channel models by 19.23–26.47 percentage points. These findings clarify the coupled effects of narrow-channel architecture, gel transport and injection parameters on the profile-control and oil-recovery performance of HPCF, providing a mechanistic basis for water control and development optimization in high-water-cut narrow-channel reservoirs. Full article

Collagen peptides (CPs) possess diverse biological activities, yet their oral efficacy is limited by gastrointestinal degradation and restricted systemic exposure of intact bioactive peptide species. Herein, a stable cholesterol-free nanoliposome system was developed using soybean phospholipids and stigmasterol through high-pressure microfluidization, followed by tangential flow filtration and spray drying to obtain a stable dry formulation. The optimized nanoliposomes exhibited a particle size below 100 nm, high peptide loading, excellent redispersibility, and remarkable physicochemical stability during refrigerated storage and under different pH and thermal conditions. During simulated gastrointestinal digestion, the stigmasterol-stabilized phospholipid bilayer effectively preserved encapsulated CPs throughout the gastric phase while facilitating peptide release under intestinal conditions. Oral administration in rats significantly enhanced collagen peptide bioavailability, increasing the plasma exposure (iAUC_{0–8 h}) of total hydroxyproline by 3.84-fold compared with free CPs. Peptide-bound hydroxyproline exposure increased 9.3-fold and accounted for approximately 94% of total absorbed hydroxyproline. UHPLC–HRMS analysis confirmed substantially enhanced systemic exposure of multiple characteristic hydroxyproline-containing dipeptides and tripeptides following nanoliposomal delivery. These findings indicate that stigmasterol-containing nanoliposomes improve the gastrointestinal stability and systemic delivery performance of collagen peptides, providing a promising strategy for enhancing the oral delivery potential of food-derived bioactive peptides. Full article

The population genetic diversity and demographic history of Hypomeces pulviger in Thailand were examined based on mitochondrial cytochrome c oxidase subunit 1 (CO1) and 16S ribosomal DNA (16S rDNA) sequence data. A total of 171 and 104 individuals from multiple populations were analyzed using CO1 and 16S rDNA sequences, respectively. The CO1 sequence dataset revealed high haplotype diversity (Hd = 0.999) and moderate nucleotide diversity (Nd = 0.0323), whereas the 16S rDNA showed lower diversity (Hd = 0.750, Nd = 0.0026). Population structure analyses showed low to moderate differentiation in CO1 sequences with a significant isolation-by-distance pattern, suggesting distance-limited gene flow, while 16S rDNA sequences showed weaker structure. Neutrality tests and mismatch distribution analyses supported a recent population expansion, as indicated by significantly negative Fu’s Fs and a unimodal distribution. Haplotype network and phylogenetic analyses further demonstrated greater resolution in the CO1 gene compared to the 16S rRNA gene. Collectively, H. pulviger populations in Thailand are genetically diverse, connected, and expanding, likely facilitated by both natural dispersal and agricultural activities. These findings provide important insights for understanding pest dynamics and developing effective management strategies. Full article

Viscous fingering is a canonical nonlinear interfacial instability that arises when a less viscous fluid displaces a more viscous one under an adverse viscosity contrast. Despite extensive investigations into the effects of fluid properties, operating conditions, and rheology, systems involving a shear-thickening displaced phase remain largely unexplored. Here, three-dimensional numerical simulations of immiscible air–fluid displacement in a Hele–Shaw cell are performed to elucidate how interfacial tension, air-inlet velocity, and gap-depth gradient regulate instability evolution. Increasing interfacial tension strengthens the Laplace-pressure barrier, suppresses shear-induced necking and pinch-off, and preserves finger topology; however, it intensifies flow diversion and delays the advancement of the central finger. Increasing the inlet velocity markedly amplifies the local interfacial shear rate and triggers pronounced shear thickening. The resulting viscous-resistance barrier redistributes momentum toward paths of least hydraulic resistance, directly promoting tip splitting and severe topological breakup. Even a small gap-depth gradient reorganizes the local hydraulic resistance and pressure field. Positive and negative gradients induce resistance-reduction and throttling effects, respectively, generating pronounced pressure shielding that governs asymmetric momentum transfer and preferential flow-path selection. These findings identify the capillary, rheological, and geometric mechanisms controlling viscous fingering during the air-driven displacement of shear-thickening fluids. Because such instabilities compromise the integrity of geological-fracture seals and the operating efficiency of semi-solid flow batteries, this study provides a mechanistic basis for stabilizing immiscible displacement and optimizing industrial fluid-transport systems. Full article

We investigated mitochondrial diversity and phylogeographic structure across all subspecies of the barn swallow (Hirundo rustica) to clarify evolutionary relationships, identify novel haplogroups, and assess the extent of hybridisation and maternal introgression. We analysed 580 complete H. rustica mitochondrial genomes together with twelve additional Hirundo species, three of which were newly obtained. We identified 553 unique haplotypes, including 166 previously undescribed ones, revealing high nucleotide diversity among subspecies. Phylogenetic analyses found five major haplogroups. Of these, a novel haplogroup (E) was discovered and ascribed to H.r. tytleri, previously considered part of H.r. erythrogaster. Comparative analyses with other Hirundo species support a southern African origin of H. rustica at the end of the Pliocene, followed by diversification and northward expansion. Our comprehensive dataset substantially refines the phylogeographic resolution of the species. We identify a novel haplogroup, clarify subspecies-level relationships, and reveal pervasive hybridisation and maternal introgression. These findings revise the evolutionary history of H. rustica and underscore the complexity of its population structure and gene flow. Beyond reconstructing lineage history, our study provides an evolutionary framework crucial for predicting environmental change responses and guiding migratory species conservation strategies. Full article

Contemporary approaches to urban water management increasingly rely on concepts such as Nature-Based Solutions (NBSs), Green Infrastructure, and Blue-Green Infrastructure. Although these frameworks have gained broad acceptance, their typological character provides limited guidance for project-oriented decision-making, as they primarily describe infrastructure types rather than their functions within integrated hydrological systems. To address this gap, this study proposes a complementary functional-operational framework for interpreting ecological infrastructures in urban flood mitigation. Employing a qualitative comparative case study methodology, we analysed four diverse international models—the Dutch Water Squares (Rotterdam), Tokyo’s underground flood control system, Copenhagen’s Cloudburst Management Plan, and Singapore’s ABC Waters Programme—to examine the systemic interaction between grey, green, and blue infrastructures at different watershed scales. The results indicate that flood mitigation effectiveness depends less on the predominance of a single infrastructure type and more on the functional coupling among them. Specifically, three primary functions were identified: rapid conveyance (grey infrastructure), infiltration and thermal regulation (green infrastructure), and dynamic storage and biodiversity support (blue infrastructure). Despite the contextual limitations and varying scales of the selected cases, blue infrastructure universally emerges as a systemic buffer that enhances urban resilience by regulating excess volumetric flows. Ultimately, the proposed framework introduces an actionable interpretative layer that complements existing typological classifications, providing planners and urban designers with a robust, scalable basis for implementing integrated ecological infrastructures. Full article

To reveal how meniscus dynamics affect wet film uniformity during slot-die coating for perovskite solar cell manufacturing, a 2D numerical model employing the VOF method is established for perovskite precursor fluids. A photoresist is used as a qualitative substitute liquid for auxiliary experimental validation, and dry film thickness is measured to characterize the relative uniformity of wet coating. The results show that the capillary number governs the upstream meniscus shape. Inlet velocity, slot gap, and coating gap influence film thickness by altering the downstream meniscus climbing height. Optimal film thickness uniformity is achieved when the pre-coating liquid volume accounts for about 31% of the total coating volume; this empirical optimal ratio is only valid within the tested inlet flow rate range under the fixed experimental conditions adopted in this work, and further multi-parameter verification under diverse process windows will be carried out in follow-up research. Full article

Neosalanx taihuensis is a fish species endemic to China, primarily distributed in the middle and lower reaches of the Yangtze and Huaihe rivers and their affiliated lakes. To assess its resource status and facilitate targeted conservation of genetic diversity, we analyzed genetic differences among populations in the lower Yangtze River. Samples were collected from four natural river populations (JJ, AQ, NJ, and TZ) and one lacustrine population (THL). Whole genome resequencing was performed to characterize genetic diversity, population structure, and selection signatures across the five populations. The results showed no obvious genetic divergence among the natural river populations, whereas all natural river populations were distinctly separated from the THL population. The natural river populations harbored higher genetic diversity than the THL population. Gene flow analysis suggested that historical gene exchange might have occurred between TZ and THL, as well as between TZ and NJ. Selective sweep analysis identified Chr01, Chr04, Chr09, and Chr15 as candidate genomic regions potentially carrying adaptive selection signatures. In summary, conservation efforts should prioritize the genetic diversity of both natural river populations and the THL population, facilitate gene flow among populations, and adopt differentiated management strategies for each group. Full article

Among developed-market stock exchanges, the NZX is distinctive. Its imputation credit system and capital-gains-tax exemption create financial incentives for firms to distribute earnings that have no close parallel elsewhere, yet what actually drives payout decisions at the firm level has never been tested in a multivariate panel framework. We analyzed 116 NZX-listed companies from 2017 to 2023. The results show that revenue and net profit prove to be the dominant positive predictors of dividend payout; cash flow and shareholders’ equity are negatively associated with the payout, suggesting that the firms prioritize capital retention in a manner consistent with the pecking order theory. Market capitalization adds nothing once earnings quality is accounted for in the model. Firms in which women occupied more than half of board seats paid, on average, seventeen times more in dividends than those with minimal female representation, a gap sustained without exception across all seven years. Domestic firms outpaid multinational firms throughout and, by 2023, had exceeded their own pre-period baseline, while multinationals had not. Our findings have implications for income-focused investors, for boards weighing payout strategies, and for policymakers assessing the case for diversity requirements. Full article

Echinophora tenuifolia subsp. sibthorpiana is an aromatic and traditionally used plant whose phytochemical diversity and pharmacological potential remain incompletely characterized. This study aimed to integrate comprehensive chemical profiling with antioxidant, antimicrobial, and antiproliferative evaluations of an acidified methanolic extract prepared from its aerial parts. Phenolic constituents, volatile compounds, and fatty acids were characterized using LC–MS/MS, GC–MS, and GC–FID, respectively. Antioxidant capacity was assessed using DPPH and ABTS assays, antimicrobial effects were evaluated by disc diffusion and broth microdilution methods, and antiproliferative activity was investigated in six human cancer cell lines and non-cancerous BEAS-2B cells. Apoptosis induction and cell-cycle alterations were further examined by flow cytometry. The extract contained a high total phenolic content of 181.78 ± 5.03 mg GAE/g and exhibited substantial DPPH and ABTS radical scavenging activities of 333.65 ± 2.94 and 262.18 ± 6.80 mg TE/g, respectively. LC–MS/MS analysis identified rutin hydrate, quinic acid, chlorogenic acid, narcissin, and vicenin-2 as the predominant non-volatile constituents. The essential oil was dominated by methyl eugenol (51.10%) and Δ-3-carene (32.23%), whereas lauric acid (29.71%) was the major fatty acid. The extract also exhibited measurable antimicrobial activity and concentration-dependent cytotoxicity, with the greatest sensitivity observed in MCF-7 breast cancer cells (IC₅₀ = 32.96 ± 4.80 μg/mL), followed by A549 and MDA-MB-231 cells. However, the relatively close IC₅₀ values observed in cancer and non-cancerous BEAS-2B cells indicated limited cancer-cell selectivity under the tested conditions. Flow-cytometric analyses demonstrated marked apoptosis induction in MCF-7 cells, reaching 57.93 ± 1.80%, together with a cell-line-dependent accumulation in the G2/M phase. Collectively, these findings indicate that E. tenuifolia subsp. sibthorpiana is a chemically diverse source of plant-derived bioactive compounds with notable radical scavenging and measurable antimicrobial and cytotoxic effects. Further bioactivity-guided fractionation and mechanistic studies are required to identify the active constituents and clarify their pharmacological relevance and selectivity. Full article

Complex water conveyance systems often involve mixed flow conditions comprising pressurized pipe networks and free-surface open channels. Every single model has its limitations in long-distance and complex water transfer projects; coupling different models can leverage their respective advantages. For this reason, this study proposes an integrated modeling framework that couples the Storm Water Management Model (SWMM) and Environmental Protection Agency Network Evaluation Tool (EPANET) models to simulate water quality in pressurized–unpressurized coupled systems. Taking the typical Yin Chao Ji Liao water diversion project as a case study, total nitrogen (TN) and total dissolved solids (TDS) were selected as representative pollutants. A total of 32 simulation scenarios were systematically evaluated across four concentration levels at four distinct monitoring points. During this synthesis, key emergency response indicators, specifically T0 (optimal gate-opening time) and T2 (drainage operation duration), were quantified. The results indicate that pollutant dispersion in the unpressurised tunnel section is primarily governed by pollutant loading, whereas in the pressurised pipeline section, it is controlled by flow velocity and pressure differentials. High-concentration pollution in the tunnel section allows for a relatively longer emergency response time (T0 = 453 min). In contrast, due to rapid transport in the pipeline section, emergency operations must be completed swiftly (≤30 min). This coupled approach effectively addresses the challenge of water quality simulation in cross-regime conveyance systems. Future research will focus on integrating real-time sensor monitoring data with this coupled model to further optimize automated early warning protocols for long-distance diversion projects. Full article

Software startups operate in environments characterized by rapid change, high uncertainty, and limited resources, resulting in high failure rates and challenges such as premature scaling and cash flow mismanagement. Prior research on pre-MVP validation has largely measured activity by volume rather than by the strength of evidence produced, leaving open whether evidence type, rather than quantity, is associated with startup performance. This study addresses that gap by investigating how early-stage software startups validate their initial idea before building their first Minimum Viable Product (MVP). Through 29 semi-structured interviews with founders from 16 software startups, pre-MVP validation activities were extracted and inductively coded into a six-level Validation Canvas spanning three validation stages identified in the literature: problem validation, problem-solution fit, and product-market fit. Startup performance was assessed through a composite ranking across funding, revenue, profitability, and runway indicators, and validation activities were analyzed thematically to derive the six evidence levels. No clear relationship was observed between the number of validation events and startup performance. Instead, stronger-performing startups tended to reach higher levels of evidence—particularly securing contingent investment commitments (Level 5) or paying customers (Level 6) before full MVP development. Level 6—paying customers before the full product exists—is identified as the strongest form of pre-MVP market evidence, as it directly validates willingness-to-pay without relying on investor confidence. In this study, product-market fit is operationalised as demonstrated commercial viability through external financial commitments rather than interest signals or free sign-ups alone. Based on these exploratory findings, the study proposes the Hierarchy of Validation: a staged, bidirectional process model in which bottom-up traversal from informal interest signals (L1) toward paying customers (L6) emerged as the primary pattern among stronger-performing startups. A top-down direction, in which experienced founders begin at higher evidence levels and work downward, is proposed as a hypothesis for future research. To our knowledge, this is among the first accounts of pre-MVP validation that differentiates strength of evidence rather than volume of activity, contributing the Hierarchy of Validation as an original, exploratory framework for early-stage software startups. These findings remain exploratory and require validation in larger and more diverse samples. Full article

Transportation networks are subject to multiple sources of uncertainty, ranging from stochastic fluctuations in demand and travel times to epistemic indeterminacy in infrastructure condition, disruption risk, and user behavior. A diverse body of mathematical frameworks has emerged in response, including stochastic programming and probabilistic reliability analysis, fuzzy and possibilistic approaches, Liu’s uncertainty theory and uncertain programming, and robust or distributionally robust optimization. This article delivers a comprehensive, mathematically oriented synthesis of these paradigms for transportation networks, with emphasis on network-level structures—paths, flows, spanning trees, and network design problems—and on reliability notions including connectivity, travel-time, capacity, and max-type reliability. A central theme is that modelling choices about uncertainty representation and reliability indices are inseparable from questions of stability and sensitivity: how robust are optimal or near-optimal configurations when parameters vary within plausible ranges? Building on deterministic post-optimal analysis, this paper reviews tolerance-based stability concepts for uncertain most reliable paths, maximum reliable transmission paths, and uncertain minimum spanning trees under Liu-type uncertainty and demonstrates how inverse-distribution mappings yield exact deterministic equivalents and belief-based robustness margins. A dedicated comparative framework is developed, summarizing the data requirements, core advantages, typical limitations, and suitable engineering scenarios of each uncertainty paradigm to guide model selection in practice. The discussion extends to practical applications in post-disaster planning, infrastructure investment prioritization, and supply chain network design and identifies open research directions including network-wide travel-time reliability under belief-based uncertainty, unified stability frameworks across paradigms, and the integration of machine learning for uncertainty distribution elicitation. The emphasis throughout is on conceptual structure, modelling assumptions, and interpretability of reliability and stability indices, thereby positioning uncertain transportation networks as a rich interface between applied mathematics, operations research, and infrastructure planning. Full article

Passenger Car Equivalent (PCE) factors are widely used to convert heterogeneous traffic streams into equivalent homogeneous flow rates for the design and analysis of roads and intersections. In developing countries, mixed traffic conditions differ substantially from those in developed contexts due to variations in vehicle composition, operating characteristics, roadway parameters, and environmental conditions. Consequently, PCE values are highly context-specific and require periodic updates to accurately represent prevailing traffic conditions. However, such updates are often infrequent because conventional PCE estimation relies on extensive field data collection through time-consuming and costly traffic surveys, as well as the availability of experienced experts to conduct and validate the analyses. In Sri Lanka, the currently adopted PCE factors are more than two decades old and no longer reflect existing traffic conditions. Although several recent studies have estimated PCE values for mid-block roadway sections of various facility types (e.g., four-lane roads, two-lane roads, and freeways), no study has comprehensively addressed intersections, which are critical for signal timing and geometric design. This study aims to develop a systematic methodology for estimating intersection-specific PCE factors using drone-based video data. Traffic data were collected at selected intersections using an unmanned aerial vehicle to obtain an accurate bird’s-eye view of vehicle movements. The methodology compares the area occupancy of different vehicle categories under varying traffic compositions with that of a passenger-car-only traffic stream operating at the same average speed. Using the extracted traffic parameters, the basic headway method was applied to establish a framework for calculating PCE factors. PCE values were estimated for ten vehicle categories, and the results reveal significant deviations, particularly for three-wheelers, motorcycles, and commercial vehicles, when compared with values currently in use. A high-level comparison with studies from other developing countries in the South Asian region indicates notable differences in vehicle impacts at signalized intersections in Sri Lanka. Furthermore, the proposed methodology provides a practical, economical, and less labour-intensive approach for estimating PCE factors, enabling more frequent updates without requiring extensive field surveys or specialized expertise. Because it relies on a straightforward headway-based framework and drone-derived traffic data, the methodology can be readily adapted to different roadway facilities, including highways, rural roads, and intersections, making it suitable for application across diverse geographical regions. Full article

The Middle Route of the South-to-North Water Diversion Project (SNWD-MR) serves as a strategic infrastructure critical to safeguarding water security in Northern China. Traversing complex geographical units, the project is perpetually exposed to long-term risks of land subsidence. Conventional Interferometric Synthetic Aperture Radar (InSAR) monitoring is hampered by waterbody isolation, causing spatial discontinuities in the retrieved deformation fields; furthermore, relying solely on deformation metrics fails to comprehensively quantify multidimensional risks. To address these issues, this study proposes an integrated assessment framework that couples time-series InSAR observations with the Analytic Hierarchy Process-Fuzzy Comprehensive Evaluation (AHP-FCE) model. To specifically mitigate the challenge of waterbody isolation, we developed a connectivity-aware multiscale down-sampling phase unwrapping strategy. By exploiting cross-canal bridges to construct a spatial connection network, a highly accurate, spatiotemporally continuous deformation field across the entire alignment was successfully reconstructed. Using the derived deformation field as the core dynamic indicator, an AHP-FCE model integrating hydrogeological features and human perturbations was constructed. A complementary evaluation process comprising sensitivity analysis and an internal physical consistency assessment was subsequently implemented. The results demonstrate that (1) the proposed algorithm effectively resolves the spatial discontinuity issue of the cross-canal deformation fields, reducing the deformation-velocity RMSE from 7.9 to 5.7 mm/y, corresponding to an approximately 27.8% reduction in RMSE relative to the traditional Minimum Cost Flow (MCF) method; (2) land subsidence along the alignment exhibits prominent spatial heterogeneity, with the northern Henan and southern Hebei sections identified as very-high-risk zones; and (3) InSAR deformation magnitude and the groundwater elevation indicator emerge as the most influential factors in the modeled risk distribution. Overall, this study expands conventional deformation monitoring into a systematic, quantitative risk assessment framework, thereby providing scientific insights and theoretical support for the early warning of geo-hazards and the smart operation and maintenance of large-scale water diversion projects. Full article