Investigations into the effects of polymers on small-scale statistics and flow patterns were conducted in a turbulent von Kármán swirling (VKS) flow. We employed the tomographic particle image velocimetry technique to obtain full information on three-dimensional velocity data, allowing us to effectively resolve dissipation scales. Under varying Reynolds numbers ($R_\lambda =168{-}235$) and polymer concentrations ($\phi =0{-}25\ {\textrm{ppm}}$), we measured the velocity gradient tensor (VGT) and related quantities. Our findings reveal that the ensemble average and probability density function (PDF) of VGT invariants, which represent turbulent dissipation and enstrophy along with their generation terms, are suppressed as polymer concentration increases. Notably, the joint PDFs of the invariants of VGT, which characterise local flow patterns, exhibited significant changes. Specifically, the third-order invariants, especially the local vortex stretching, are greatly suppressed, and strong events of dissipation and enstrophy coexist in space. The local flow pattern tends to be two-dimensional, where the eigenvalues of the rate-of-strain tensor satisfy a ratio $1:0:-1$, and the vorticity aligns with the intermediate eigenvector of the rate-of-strain tensor, while it is perpendicular to the other two. We find that these statistics observations can be well described by the vortex sheet model. Moreover, we find that these vortex sheet structures align with the symmetry axis of the VKS system, and orient randomly in the horizontal plane. Further investigation, including flow visualisation and conditional statistics on vorticity, confirms the presence of vortex sheet structures in turbulent flows with polymer additions. Our results establish a link between single-point statistics and small-scale flow topology, shedding light on the previously overlooked small-scale structures in polymeric turbulence.

Resilient Zulu moral economy compelled Natal’s sugar planters and white settler state to introduce Indian indentured workers since 1860. As concerns over productivity in a weak colonial economy informed this decision, meticulous management of labor time crucially shaped the treatment of migrant Indian indentees. Moreover, systemic violence in capital’s life processes formed the culture of work-discipline in the plantations and in other industrial sectors. Subsequently, as contract expired Indian indentees acquired relative economic mobility compared to Africans, they appeared in Zulu critiques of Natal’s settler colonial order. Ironically, dispossessed Zulus reproduced colonial logic of time management while discussing the comparative economic success of Indian “newcomers.” Zulu critiques of colonial labor management also complemented the racial exclusivity of migrant Indians. Analyzing the complex workings of capital, labor, and race in nineteenth-century Natal, this article explains how capital’s life processes shaped violent conflicts in the intimate domestic space of working-class lifeworld.

Minority governments are common across parliamentary systems, and a large body of literature has examined their stability and performance. Meanwhile, we know very little about how voters perceive this government type and whether they understand its political implications. We survey voters in Denmark, Germany, and Sweden, three European countries with varying degrees of exposure to minority governments, about their knowledge and perceptions of minority governments. We find that voters have knowledge levels comparable to those about the role of political parties, and that this is independent of the respective prevalence of minority governments in each country. Informed voters express stronger preferences for majority governments. However, minority governments are associated with specific positive representational traits, specifically with the impression that such governments listen more to the demands of all voters, and general perceptions are stronger for knowledgeable voters. The findings have implications for how elites can formulate arguments in favour or against minority governments that may resonate with voters.

This article is concerned with finite rank stability theory, and more precisely two classical ways to decompose a type using minimal types. The first is its domination equivalence to a Morley product of minimal types, and the second is its semi-minimal analysis, both of which are useful in applications. Our main interest is to explore how these two decompositions are connected. We prove that neither determine the other in general, and give more precise connections using various notions from the model theory literature such as uniform internality, proper fibrations, and disintegratedness.

Floating particles deform the liquid–gas interface, which may lead to capillary repulsion or attraction and aggregation of nearby particles (e.g. the Cheerios effect). Previous studies employed the superposition of capillary multipoles to model interfacial deformation for circular or ellipsoidal particles. However, the induced interfacial deformation depends on the shape of the particle and becomes more complex as the geometric complexity of the particle increases. This study presents a generalised solution for the liquid–gas interface near complex anisotropic particles using the domain perturbations approach. This method enables a closed-form solution for interfacial deformation near particles with an anisotropic shape, as well as the varying height of the pinned liquid–gas contact line. We verified the model via experiments performed with fixed particles held at the water level with shapes such as a circle, hexagon and square, which have either flat or sinusoidal pinned contact lines. Although in this study we concentrate on the equilibrium configuration of the liquid–gas interface in the vicinity of particles placed at fixed positions, our methodology paves the way to explore the interactions among multiple floating anisotropic particles and, thus, the role of particle geometry in self-assembly processes of floating particles.

This article – arising from an ERC-funded project on the lived experiences of dictatorship – explores the development of and approaches to the history of everyday life under repressive political systems, presenting the historiographical, conceptual, and contextual points of contact, synergy, and divergence between historians working in and on Europe, Southern Africa, and Latin America. As a historiographical review article, this piece provides both a critical assessment of and novel intervention in these respective literatures, making the case for ‘decentring’ European histories and historiographies, to encourage greater engagement and collaboration between those working on different historical and geographical contexts.

The study explores the engagement of Russophone Ukrainians with educational policies that increase the status of the Ukrainian language, the standardized tests of Ukrainian, and the subject tests that could be passed in Ukrainian. It argues that this centralized unitary language policy has received support from Russophones. It does so by analyzing the language choices of Russophone students when taking standardized tests in various subjects, as well as admission policies and discussions of relevant policies in local media and social media of the Russophone city of Kharkiv. It shows that following the introduction of standardized tests, the value of Ukrainian has increased across various actors: students have been choosing Ukrainian more, universities have valued Ukrainian in the admission process, and local citizens have defended the status of Ukrainian, relying on decolonial rhetoric. It shows that the decolonial framing of the Ukrainization policies resonated with Russophones enough for them to support them, and not to result in a backlash.

When analyzing the nation-state, studies of Pakistan often portray the Pakistani state as autocratic and dictatorial. While the Pakistani nation-state performs various hegemonic roles, it is also “cultured.” This article illustrates this point by focusing on the nation-state’s patronage of cultural projects in the 1960s (and beyond), tracing the genealogies of sites in Lahore’s Greater Iqbal Park (the Minar-e-Pakistan monument, Hafeez Jalandari mausoleum, and the National History Museum) along with the Quaid-e-Azam mausoleum in Karachi. The article centers these as “sites of memory,” exploring the hybrid tensions between tourism, citizenship, and modern memory in postcolonial Pakistan.

Directional freezing of brine is widely found in numerous environmental and industrial settings. Despite extensive studies, the microscopic evolution of ice-brine structures remains unclear. By combining in situ micro-computed tomography visualisation and theoretical analyses, we reveal new details inside the porous ice structure and its evolution towards a cleaner ice layer. We identify three distinct stages characterised by different brine exclusion rates during solidification: a rapid initial stage possibly lasting seconds from nucleation to local equilibrium without long-range heat or mass transfer; a second stage where the system reaches global thermal equilibrium, involving brine expulsion by volume expansion and convection associated with gravity; and a final prolonged stage dominated by diffusion. Comparison between analytical solutions and the migration rates of microstructural features such as brine stripes, columns and pockets extracted from photographic images confirms these understandings. Morphologically, we capture the formation of random striped patterns together with brine columns during downward freezing and brine skirts during upward freezing, all of which gradually transform into vertically aligned polygonal patterns. The volume fraction of brine pockets in porous ice near the cold end reduces to less than 10 % after 22 h in most experiments. The residual brine pockets, however, are not rejected out of the porous ice as fast as predicted by diffusion and remain persistent. Our findings provide new insights into the brine freezing dynamics, with implications ranging from sea ice formation to freeze desalination and general solidification of binary melts.

In Euclidean geometry, a tangential polygon or a circumgon is a polygon that contains an inscribed circle which is also called an incircle and the radius of its incircle is called the inradius. A tangential polygon may be concave or convex. If it is concave, it is the extension of some of its sides that is tangent to the incircle. In this Article we restrict ourselves to convex tangential polygons, so that their corresponding incircles are tangent to each of its sides. Every regular polygon is a circumgon and there are also irregular polygons that are circumgons but not all irregular polygons are circumgons. In what follows, we shall use circumgon or tangential polygon interchangeably according to the situation.

In this paper, a highly integrated wideband 3 × 3 Nolen Matrix with inherent filtering characteristics is proposed. It is based on an arbitrary-phase-difference (A-PD) filtering coupler and phase compensation networks. The proposed A-PD filtering coupler, composed of three groups of coupled lines, offers outstanding advantages, including wide bandwidth, flat output distributions, high frequency selectivity, and compact structure. To address the challenges introduced by the series topology of the Nolen matrix, a differential phase shift network and a phase slope adjustment network are incorporated, ensuring a constant phase difference between stages and minimizing in-band phase errors at the output ports. By integrating the A-PD filtering coupler with the phase compensation networks, a compact Nolen matrix centered at 3.5 GHz is realized, occupying only 0.5 λg × 0.5 λg. Measurement results validate its excellent performance, demonstrating an overlapping bandwidth exceeding 50% under the criteria of 10-dB return loss, 3-dB passband, ±1 dB amplitude imbalance, and ±5° phase difference error. Furthermore, the design achieves over 15 dB stopband rejection.

Distributional learning enables listeners to form phonetic categories by extracting statistical regularities from speech input. Younger Cantonese speakers can acquire the Mandarin level-falling (T1–T4) contrast through distributional learning, with bimodal exposure facilitating category formation and unimodal exposure suppressing it, and with fine-grained pitch sensitivity predicting success. However, aging is associated with declines in pitch sensitivity and phonetic boundary formation, which may disrupt this process. This study examined whether Cantonese-speaking older adults exhibit distributional learning of Mandarin T1–T4 and whether individual cognitive factors predict learning success. Sixty-four participants completed a pretest–training–posttest procedure with bimodal or unimodal exposure. While older adults improved in tone discrimination, no group differences emerged. Further analysis showed that those with lower pitch-related auditory memory failed to learn from unimodal input. On the other hand, fine-grained pitch perception abilities did not predict learning outcomes. These results suggest that older adults may rely on alternative learning mechanisms, such as memory-based strategies, when exposed to ambiguous input distributions. The findings indicate a shift from perceptual encoding to memory-driven processing in aging and highlight the limits of passive statistical learning in older adulthood.

Biometric identification represents a transformative, advanced technology with significant implications for herd management. Its adoption addresses the critical requirement of accurate identification methods along with upgraded approaches on higher traceability, disease control, genetic management, and economic returns. In this work, a database of muzzle images was collected from 264 Vrindavani cattle, with ages ranging from 6 months to 10 years. To assess the accuracy of muzzle print as a biometric means of identification, this study investigated the efficiency of a 68-layer convolutional neural network called SqueezeNet for the identification of Vrindavani cattle (a crossbred developed in India) using 2,640 muzzle images. It was observed that SqueezeNet gives a harmonious blend of superior accuracy and minimal complexity, rendering it an optimal option for devices with constrained specifications and computing power. Further, the results of this study showed an identification accuracy of 97.22% with a remarkably small model size (<4 MB). This compact size makes it significantly advantageous compared to other models.

Close friends Rebecca and Aisha are taking an integral calculus class. With their permission, we listen in on a conversation that they are having about an integration problem.

The paper analyses the creation of socialist Poland’s foreign and foreign economic policies from 1957 to 1967, focusing on the country’s involvement with the General Agreement on Tariffs and Trade (GATT) and the European Economic Community (EEC). It argues that for the Polish policymakers, the interest in accession to GATT went beyond economic benefits such as alleviating the EEC’s protectionism and securing better terms for exports to the Common Market. Joining the Agreement was also important for the political goals of Polish diplomacy and was considered a part of a general drive for rapprochement with the West and implementation of the principle of peaceful coexistence. Redefining the scope of foreign policy, Polish diplomats attempted to embed Poland in a network of international interdependency and wanted to see the country as a pioneer of the East–West détente.