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We investigate the occurrence of flow circulation in an open triangular cavity filled with a gas at highly rarefied conditions. The cavity is subject to an external shear flow that is in either the circular or linear direction at its inlet. The problem is studied analytically in the free-molecular limit and numerically based on the direct simulation Monte Carlo (DSMC) method. The corner walls are modelled based on the Maxwell boundary condition, as either specular or diffuse. The results are obtained for arbitrary values of the outer flow speed and corner angle. Remarkably, it is found that multiple recirculation zones occupy the corner domain in the absence of molecular interactions. In the specular-corner set-up, such topologies occur at non-large outer-flow speeds and distinct corner-angle intervals of $[\pi /(n+1),\pi /n]$ with $n=3,5,\ldots$. In the diffuse-wall case, the cavity flow field contains two recirculation zones at sufficiently low corner angles for both circular and straight outer flows. With increasing angles, the straight-flow configuration differs, reducing the number of vortices to one and then none. The results are rationalised based on ballistic particle kinematics, suggesting insight into the relation between the microscopic description and the hydrodynamic (observed) generation of circulation. The effects of molecular collisions on the corner flow pattern, as well as more elaborate gas-surface interaction models, are inspected based on DSMC calculations, indicating visible impacts on the macroscopic flow structure at large Knudsen numbers.
The hydrodynamic performance of oscillating elastic plates with tapered and uniform thickness in an incompressible Newtonian fluid at varying Reynolds numbers is investigated numerically using a fully coupled fluid–structure interaction computational model. By leveraging the acoustic black hole effect, tapered plates can generate bending patterns that vary from standing wave to travelling wave oscillations, whereas plates with uniform thickness are limited to standing wave oscillations. Simulations reveal that although both standing and traveling wave oscillation modes can produce high thrust, travelling waves achieve significantly higher hydrodynamic efficiency, and this advantage is more pronounced at higher Reynolds numbers. Furthermore, regardless of the oscillation mode, tapering leads to greater hydrodynamic performance. The enhanced hydrodynamic efficiency of travelling wave propulsion is associated with the reduced amount of vorticity generated by tapered plates, while maintaining high tip displacements. The results have implications for the development of highly efficient biomimetic robotic swimmers, and more generally, the better understanding of the undulatory aquatic locomotion.
The relationship between political science and sociolegal scholarship is, at it’s best, a constitutive one. This essay argues that the two fields of study have taken turns illuminating important aspects of law, politics, and social life – responding, in turn, to the theoretical and empirical findings of each other. Law and Society scholarship, in particular, presses political scientists to rethink their foundational assumptions about the rule of law, the power of institutions, and the meaning of judicial decision-making and processes. Some of this rethinking may result, as we posited on the panel which gave rise to this work, in a fruitful “undisciplining” of the field, and re-imagining of the political.
Do anti-elitist parties behave differently in parliament than other parties? Existing evidence is inconclusive: some studies suggest that anti-elitist parties do not show a shared voting pattern as this is mainly structured by their left- or right-wing ideology. Others suggest that these parties vote against legislation more often. In order to address this question, we develop a new method that allows one to look at different explanations of voting concurrently while also taking into account characteristics of the vote. We find that anti-elitist parties do vote in a similar way and different from other parties, but only on legislative votes. As such, we present a major step forward in our understanding of and methodological approach to parliamentary voting behavior.
This article introduces the open access ArcGIS database Weather Extremes in England's Little Ice Age, 1500–1700. The database maps narrative weather records from a range of sources, including historical chronicles, personal diaries, and extreme weather pamphlets. A source of particular note is the manuscript commonplace book of Richard Shann (1561–1627), a Catholic copyholder from Methley, Yorkshire. Shann included his weather notations in two distinct sections, with the first transcribing events between 1617–27, and the second, between 1586–1622. Falling between the genres of chronicle and diary, these records provide a sustained perspective on local weather conditions. In their turn-of-the-century focus, they also help to clarify the specific impact of the Little Ice Age on England, as their local observations reflect a national trend wherein seventeenth-century weather becomes not only more cold but also more unstable.
To solve the problems of precise operation and real-time interaction during the spraying process of industrial robots, a new spraying method based on digital twin technology is proposed. In view of the limitations of traditional spraying processes in complex geometric shape processing, spraying uniformity control, and operational flexibility, this study built a highly simulated virtual environment based on digital twin and human–machine collaboration technology, allowing operators to guide the robot in real time for precise spraying operations. The use of multisensor fusion technology achieves a high degree of consistency between the physical and virtual environments, ensuring that the system can maintain high-precision spraying on complex workpiece surfaces. The experimental designed spraying tasks for different geometric shapes and evaluated the performance of the system’s interactive spraying method in terms of real-time feedback guidance and path planning. The results show that the proposed method significantly improves the accuracy and efficiency of the spraying process, especially showing obvious advantages when processing complex geometric workpieces, and provides a new technical approach for future high-precision manufacturing.
To explore cancer patients’ understanding of Advance Care Planning (ACP) and identify the main barriers hindering its effective implementation in clinical practice.
Methods
This qualitative descriptive study included Brazilian women with breast cancer aged 18–75 years, all with preserved functional status, recruited by convenience sampling. Exclusion criteria were difficulty using online calls or significant communication impairment. Data collection involved a sociodemographic questionnaire and a follow-up interview. After receiving an informational brochure, participants were contacted by video call 14 days later and asked, “How do you understand what ACP is?” Interviews were conducted confidentially at home, transcribed, and analyzed according to qualitative research reporting guidelines.
Results
Sixty-one women participated. Most had difficulty understanding ACP; nearly 40% could not define it. Main barriers included cultural resistance to discussing death, reliance on family members or physicians for decision-making, and lack of clear information. Many participants confused ACP with preventive care. A conceptual multilevel model was developed, showing how cultural taboos, family dependence, and systemic inertia interact to sustain barriers through a feedback loop in which cultural avoidance reinforces structural gaps and institutional neglect.
Significance of results
This study provides evidence on how ACP is understood and misinterpreted by cancer patients in a middle-income Latin American setting, an area that remains underrepresented in the literature. By demonstrating that misconceptions, cultural taboos, and systemic barriers operate through a reinforcing multilevel process, the findings offer a conceptual framework that explains why ACP remains marginal in routine oncology care. The model highlights critical points for intervention, including patient education, professional communication, and institutional support, and is directly applicable to similar sociocultural contexts characterized by strong family involvement and biomedical dominance. These results have clear implications, supporting the integration of ACP as a proactive, relational, and value-based process rather than a late end-of-life intervention.
Khasi nightshade (Solanum khasianum C.B. Clarke) is a perennial poisonous weed in tropical and subtropical regions that seriously threatens the development of grasslands. For a high-risk invasive weed, a comprehensive understanding of its seed germination characteristics is important for predicting its spread and developing effective management strategies. However, the impact of various abiotic factors on the germination of S. khasianum is not clear. The study first explored the effect of temperature, light, pH, osmotic stress, salt stress, high-temperature pretreatment and burial depth on the germination of S. khasianum. Seeds germinated at constant temperature of 30, 33, 35, and 38 C, and the germination rate (GR) ranged from 10% to 94%. The optimum germination temperature was 35 C, while germination was completely inhibited at 25 C or 40 C. The germination of S. khasianum was greatly promoted by alternating light and darkness (16/8, 12/12, 8/16 h), but was not sensitive to the time change of photoperiod. The GRs were more than 70% in the pH range of 4 to 10, and strongly acidic environment was more suitable for the germination. The GR gradually decreased with the osmotic potential from 0 to -0.2 MPa, and no germination occurred at -0.4 MPa. Accordingly, germination was also low in sodium chloride (NaCl) solution with concentration higher than 60 mM. Seeds of S. khasianum were not tolerant to high temperature, GR decreased significantly after exposure to 40 C for five minutes, and it decreased to 3% at 120 C. The emergence rate was the highest (93%) when the seeds were buried on the soil surface, while seedlings hardly appeared when the burial depth was more than 2 cm. This study revealed the possible adaptive mechanism of invasive S. khasianum, and will contribute to the effective prediction and management in grasslands.
This article recovers the international thought of Jón Ólafsson—an Icelandic journalist, transatlantic migrant, and settler colonialist—to illuminate how visions of world order were articulated from the Northern European periphery at the fin de siècle. While scholars have emphasized the rise of Anglo-Saxonist ideas—particularly the notion of a racial-imperial union between the United States and Britain—as central to late nineteenth-century reimaginings of global politics, little attention has been paid to how such ideas were adapted beyond the English-speaking world itself. Tracing how Ólafsson reworked this paradigm for a transnational audience, the article argues that he expanded the imagined boundaries of the Angloworld through appeals to what he saw as Teutonic whiteness. The result was what might be termed a ‘Teutonisphere’: a vision of racial solidarity illustrating how great-power narratives were refracted, appropriated, and creatively reconfigured by intellectuals in peripheral regions. Cast as pristine exemplars of the Teutonic race, Icelanders were imagined as ideal agents to rejuvenate Anglo-Saxon colonization from the US frontier and Canadian prairies to the South African veldt.
This study investigates finite-wall effects in vortex ring–wall interactions on flat circular plates with diameters $1.5D_n \leqslant D \leqslant 10D_n$, where $D_n$ is the nozzle diameter. Flow visualisation experiments were conducted across a broad range of vortex Reynolds numbers, ${\textit{Re}}_{\varGamma } \approx 600$–$2800$, while particle image velocimetry measurements were performed over a focused range of ${\textit{Re}}_{\varGamma } \approx 1300$–$1900$. The formation length was fixed at $L/D_n = 2$, where $L$ is the length of the ejected fluid slug. The plate sizes examined span from those reproducing the canonical infinite-wall behaviour to plates smaller than the vortex ring’s diameter. Three distinct regimes are identified based on the relative plate size: (i) ‘infinite’ plates where edge effects are negligible; (ii) ‘quasi-infinite’ plates where boundary-layer separation dominates but weak edge-generated vorticity emerges; and (iii) ‘finite’ plates where boundary-layer roll-up over the edge replaces surface separation, yielding strong edge effects. These regimes are established through vorticity contour analysis and flow visualisation, supported by quantitative measurements of circulation, trajectory, vortex-core velocity, eccentricity and boundary-layer separation. Within the explored range, geometric extent rather than Reynolds number governs the interaction dynamics. Finite-edge effects manifest through enhanced and earlier secondary vorticity formation, stronger primary vortex decay and elongated rebound trajectories with larger orbital periods. When the plate diameter becomes smaller than the vortex ring diameter, edge clipping rapidly disrupts the coherent vortex structures. The results provide a canonical framework for understanding finite-surface interactions and for distinguishing edge-induced dynamics from curvature or confinement effects observed in previous studies.
Henry John Temple, third Viscount Palmerston, the ebullient Victorian foreign secretary and prime minister, is no stranger to historians; few stones in his life have been left unturned. One exception is Palmerston’s relationship with the Devonshire borough of Tiverton, which he represented in Parliament for thirty years. Palmerston’s biographers have traditionally downplayed the significance of the Tivertonians and this article offers a more sophisticated approach, by relating popular politics to the nascent historiographical subfields of celebrity and memory. It finds that, during Palmerston’s lifetime, the celebrity status that he used Tiverton to cultivate became a source of civic pride and a pillar of the borough’s identity. Then, after Palmerston’s death, the politics of celebrity became intertwined with the politics of memory. Control of the political space that Palmerston’s legacy occupied became a prerequisite for electoral success, as political debates mutated into bitter arguments over which faction had the better claim to his legacy. This article therefore seeks to illuminate new ways of reading Palmerston and to contribute to the growing body of work on Victorian celebrities and the political uses of the Victorian past.
Delaying cover crop termination until planting (i.e., planting green) in no-till production systems is likely to mediate the fate of herbicides that provide soil residual activity. In a planting green scenario, there is currently limited knowledge of how the interaction between physiochemical properties of cover crop residues and sorption properties of herbicides influence the washoff potential of residual herbicides from cover crop residues. We conducted field- and laboratory-based experiments using herbicide washoff assay methods to evaluate the interaction between lignin (%) of cereal rye (Secale cereale, L.) and herbicide lipophilicity (Kow) on washoff potential across herbicide application timings. We contrasted herbicides with intermediate lipophilicity (atrazine, pyroxasulfone , and S-metolachlor) to less (mesotrione) and highly lipophilic (pendimethalin) herbicides. When applied into living cereal rye, washoff of atrazine and pyroxasulfone were greater than mesotrione and S-metolachlor. Pendimethalin had the least washoff potential. When applied into fresh- to aged-cereal rye residues (0 to 84 days after termination), pendimethalin washoff was below the detection threshold. Washoff of mesotrione, pyroxasulfone, and atrazine declined as lignin (%) in cereal rye residues increased, whereas a positive relationship between S-metolachlor recovery and lignin (%) was observed. Results of our study partially support the hypotheses that (1) herbicide lipophilicity, measured via log Kow values, can be a useful indicator of washoff potential among residual herbicides used in cover crop systems, and (2) washoff potential declines as cover crop residues age within herbicide application windows.
Following Entman’s observation that policy frames define social problems, diagnose causes and suggest remedies, we examined the strategies that 12 U.S. governors (from states matched according to population size and density, demographic composition, per capita incomes, geographic proximity, and COVID-19 incidence) used to frame COVID-19 policy agendas. After scraping the governors’ statements about COVID-19 from press releases issued from January 2020 to May 2023 (N = 14,629), we leveraged ChatGPT (GPT) to identify and assess the intensity of public health, economic stability, and civic vitality frames. Subsequent analysis explored differences in the framing strategies according to the governors’ political party and gender. In the process, this study underscores the importance of AI prompt engineering to realize GPT’s transformative potential to facilitate communication research by efficiently identifying and assessing the content of policy frames.