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We revisit Brenner's seminal work on the Stokes resistance of a slightly deformed sphere (Chem. Engng Sci., vol. 19, 1964, p. 519), evaluate its range of validity and extend its applicability to higher deformations for axisymmetric particles, using hydrodynamic radius as the measure of Stokes resistance. Brenner's method solves the flow around a slightly deformed sphere through two mapping steps: the first mapping translates the surface velocity on the deformed sphere to that over a reference sphere of arbitrary radius using an asymptotic expansion of the flow field in terms of deformation amplitude and a Taylor expansion of the velocity field around the surface of the reference sphere. Subsequently, the second mapping extrapolates the velocity field from the surface of the reference sphere to any point in the fluid using Lamb's general solution for Stokes flow. While the original work addresses slightly deformed spheres to a linear order in deformation amplitude, we demonstrate that the first mapping, in combination with axisymmetric spectral modes (J. Fluid Mech., vol. 936, 2022, R1), can accommodate significant deformations to arbitrary orders of perturbation, and thus is not limited to slightly deformed spheres. Also, while first-order analysis is suitable for nearly spherical particles, second-order terms can provide a reasonable range for significantly higher deformations.
One of the elegant achievements in the history of proof theory is the characterization of the provably total recursive functions of an arithmetical theory by its proof-theoretic ordinal as a way to measure the time complexity of the functions. Unfortunately, the machinery is not sufficiently fine-grained to be applicable on the weak theories, on the one hand and to capture the bounded functions with bounded definitions of strong theories, on the other. In this paper, we develop such a machinery to address the bounded theorems of both strong and weak theories of arithmetic. In the first part, we provide a refined version of ordinal analysis to capture the feasibly definable and bounded functions that are provably total in $\textrm{PA}+\bigcup _{\beta \prec \alpha } \textrm{TI}({\prec_{\beta}})$, the extension of Peano arithmetic by transfinite induction up to the ordinals below $\alpha$. Roughly speaking, we identify the functions as the ones that are computable by a sequence of $\textrm{PV}$-provable polynomial time modifications on an initial polynomial time value, where the computational steps are indexed by the ordinals below $\alpha$, decreasing by the modifications. In the second part, and choosing $l \leq k$, we use similar technique to capture the functions with bounded definitions in the theory $T^k_2$ (resp. $S^k_2$) as the functions computable by exponentially (resp. polynomially) long sequence of $\textrm{PV}_{k-l +1}$-provable reductions between $l$-turn games starting with an explicit $\textrm{PV}_{k-l +1}$-provable winning strategy for the first game.
This article presents a business history of the Barranquilla Railway and Pier Company (BRPC) and its impact on Colombia’s Caribbean region. It explores the company’s operations, profitability, shareholders, infrastructure development, and competition with other coastal railways for insights into the role of foreign capital in regional growth. The BRPC’s railway and port infrastructure connected the coastal city of Barranquilla with the Colombian interior, allowing the city to supplant Cartagena as the country’s principal international port. Statistical analysis reveals the railway’s remarkable profitability, which attracted transnational investors, who consolidated majority control. The company’s ability to leverage engineering expertise and capital underscored its strategic significance, yet its interests centered on protecting its transport monopoly. The railway’s lack of visibility in London and information asymmetries shaped investor perceptions. Extending the pier demonstrated BRPC’s role in accommodating rising export volumes during Colombia’s “despegue cafetero.” However, the railway faced obsolescence, as the government opened the obstructing Bocas de Ceniza sandbank and pursued railway nationalization. The railway’s redundancy, demographic shifts, and rise of Buenaventura underscore its eventual decline. This paper reveals the complex dynamics between foreign capital, infrastructure, and trade monopolies in shaping uneven development. It highlights the BRPC’s overlooked yet fundamental role in Colombia’s export economy and Barranquilla’s ascendancy.
The cry of “Get married women out of the factories!” echoed across the Spanish industrial landscape at the turn of the twentieth century, driven by two intertwined factors. From a societal perspective, women's place was at home, not in factories. On an economic note, concerns arose over women's lower wages displacing men from jobs. This research delves into a case study of a workers’ claim aimed against women. It aims to illuminate the interplay of social demands and gender dynamics in labour history and business operations. Using as a case study a strike among male workers at the Amatller chocolate factory in May 1890, it seeks insights into gender complexities and women's challenges when joining the workforce. Male factory workers sought better conditions but directed their frustrations at women, influenced by prevailing social discourse. Women joined the factory, but portraying them as victors would be an oversimplification. Their presence was restricted, confined to manual tasks, with few opportunities for advancement.
In 2013 and 2019, two separate encounters with a white shark (Carcharodon carcharias) were documented within Indonesian waters. Of particular importance was ca. 6.0 m male C. carcharias that was captured in Lombok, Indonesia in 2013, where an upper lateral tooth was retained. Using the D-loop sequences of the mitochondrial DNA (mtDNA) associated with this captured white shark, the mtDNA was compared to the available mtDNA sequences in GenBank® associated with the Northwest Pacific and Australian (i.e. Southern-Western and Eastern) C. carcharias subpopulations to determine its point of origin. Results from the mtDNA analyses suggest that the point of origin for this captured C. carcharias is from one of the Australian subpopulations. When compared to primary literature, this migration presents a northerly range extension for this species; however, since it is unclear what Australian subpopulation this shark was from it is uncertain what subpopulation this range extension applies to. Although C. carcharias presence within Indonesian waters is likely a rare occurrence, being that Indonesia represents the largest shark fin exporter in the world, the utilization of these waters and potential unsustainable exploitation poses a definitive threat to this highly migratory top predator. Therefore, further research investigating the purpose and site fidelity of C. carcharias within these waters is critical to future multijurisdictional protection of this top predator.
We show that an infinite group G definable in a $1$-h-minimal field admits a strictly K-differentiable structure with respect to which G is a (weak) Lie group, and we show that definable local subgroups sharing the same Lie algebra have the same germ at the identity. We conclude that infinite fields definable in K are definably isomorphic to finite extensions of K and that $1$-dimensional groups definable in K are finite-by-abelian-by-finite. Along the way, we develop the basic theory of definable weak K-manifolds and definable morphisms between them.
Tanaidaceans have a worldwide distribution, with 36 families, 316 genera, and 1575 extant species described. This study aimed to compile the resulting taxonomic information for Brazilian waters obtained to produce the available online catalogue Taxonomic Catalogue of the Brazilian Fauna. Results show 63 species described for Brazilian waters: 30 Apseudomorpha and 33 Tanaidomorpha, distributed in 46 genera and 18 families. For apseudomorphan, Kalliapseudidae is the most diverse family (12.7%), followed by Apseudidae and Parapseudidae (9.5% each). For tanaidomorphan, Typhlotanaidae is the most diverse (15.9%) followed by Leptocheliidae (9.5%) and Tanaididae (7.9%). In Brazilian waters, more than 60% of Tanaidacea species are distributed in shallow waters (42 species; 63.6%), including continental areas, and about 1/3 are recorded from deep-sea (24 species; 36.4%). Southeast Region of Brazil holds most records with 46 occurrences, followed by the Northeast Region with 19 occurrences. Our results highlight the increasing number of publications and new Brazilian tanaids species in the last 15 years, and this is directly correlated to where specialists in alpha-taxonomy, systematics/phylogeny, and ecology are based in. Our current dataset also indicates an important aspect regarding the lack of taxonomic experts of Tanaidacea worldwide, but especially in Brazil. This study gives an overview of all the information that may help elucidate future research on the taxonomic diversity of tanaidaceans in Brazil, thus it is expected that this may encourage further studies and specialists for the group.
We test whether tissue moisture content affects settling and feeding behaviours of Monochamus galloprovincialis, a forest insect that feeds on multiple pine species and is a vector of tree disease. In a watering experiment using potted Aleppo pine trees, Pinus halepensis Miller (Pinaceae), water deprivation reduced mid-day shoot water potentials and corresponded to lower phloem water content. In short-term choice assays allowing prereproductive beetles to select among P. halepensis phloem for maturation feeding, beetles preferred to settle and initiate feeding on phloem with lower moisture content and over a 24-hour period consumed more phloem from oven-dried phloem punches. No differences in settling and feeding preferences between males and females were observed. In no-choice feeding assays where beetles were confined to either “dry” or “fresh” shoots (moisture differential ∼10%) over a five-day period, beetles fed on fresh shoots excreted on average 38% more frass, potentially consistent with higher consumption requirements. Our data suggest that water input affects shoot water potentials of Aleppo pine and corresponding phloem water content, which influences feeding preferences of newly emerged M. galloprovincialis.
Fire is a material and social process that is different in different periods and places. This article examines the fires set during the largest, and last, uprising of the enslaved in Jamaica, which occurred in the island's western parishes after Christmas 1831. It argues that different sorts of fire were central to processes of production and everyday life under plantation slavery, and examines what the burnings of 1831–32 reveal about the fight against enslavement in the early nineteenth century. A close reading of the records of the trials that followed the uprising details the methods used to burn plantations; the decisions over what to burn and what to save; and the contested social and political relations involved in encouraging or extinguishing the flames. This demonstrates that fire was a material means of creative destruction for the rebels that turned the everyday practices of commodity production and coerced social reproduction against the plantation infrastructure; that destroying buildings by fire both denied and made claims on the land, and sought to remake the Jamaican landscape for other forms of inhabitation; and that the collectivities forged through fire were inevitably shaped by both shared endeavors and tensions within and between groups of plantation inhabitants facing an uncertain future. Overall, it seeks to understand the use of fire in the 1831–32 uprising to fight for freedom as part of a “politics of habitation.”
As a required sample preparation method for 14C graphite, the Zn-Fe reduction method has been widely used in various laboratories. However, there is still insufficient research to improve the efficiency of graphite synthesis, reduce modern carbon contamination, and test other condition methodologies at Guangxi Normal University (GXNU). In this work, the experimental parameters, such as the reduction temperature, reaction time, reagent dose, Fe powder pretreatment, and other factors, in the Zn-Fe flame sealing reduction method for 14C graphite samples were explored and determined. The background induced by the sample preparation process was (2.06 ± 0.55) × 10–15, while the 12C– beam current were better than 40μA. The results provide essential instructions for preparing 14C graphite of ∼1 mg at the GXNU lab and technical support for the development of 14C dating and tracing, contributing to biology and environmental science.
Omobranchus sewalli is a native Indo-Pacific blenniid recently introduced and established along the Brazilian coast. The putative introduction was through ballast water and/or ship hull biofouling. Herein, we report the presence of the species for the first time inside of the Paranaguá Estuarine Complex (PEC) which is recognized as a RAMSAR site and listed as a Wetland of International Importance. The mature specimens of O. sewalli were found in intertidal and shallow subtidal waters in the mixture zone in the estuary, suggesting the establishment of the population. The presence of port terminals in this area indicates that O. sewalli colonize PEC using ship hull fouling or larval dispersal from the shallow inner shelf.
Although the Lower Kasai was identified by Jan Vansina as a likely center for highly complex societies, he failed to recognize that sixteenth-century sources had mentioned the Empire of Mwene Muji as a large polity in that region. Studying the well known and recently discovered literature on West Central Africa, as well as a critical study of oral tradition, shows considerable evidence for the antiquity and existence of Mwene Muji.
A rise in the number of moral individuals in a group can hurt the morality of the group’s collective action. In this paper, we characterize strategic environments and models of morality where this is true solely because, after all, individual morals are private information.
We investigate air-entraining flows where degassing, rather than fragmentation, plays a significant role. Of interest is the power-law slope $\beta$ of the bulk bubble size distribution $N(a)$ during the air-generating period, when the total volume of bubbles is increasing. We study a canonical air-entraining flow created by strong underlying free-surface turbulence. We perform analysis using the population balance equation (PBE) and computations using direct numerical simulations (DNS) with bubble tracking. We quantify the importance of degassing by the ratio of degassing flux ($Q_D$) to entrainment flux ($Q_I$), $\mathcal {D}=Q_D/Q_I$, and the ratio of degassing rate ($\varLambda (a)$) to fragmentation rate ($\varOmega (a)$) for a bubble of radius $a$, $\varLambda (a)/\varOmega (a)$. For a broad range of large Froude numbers ${{Fr}}=U/\sqrt {L g}$, DNS give $\mathcal {D}=\operatorname {O}(1)$ (independent of ${{Fr}}$), showing that degassing is relevant, and $\varLambda (a) \gg \varOmega (a)$, showing that the bubble population is degassing-dominated. In contrast to fragmentation-dominated populations, such as those due to wave breaking, where $\beta =-10/3$, degassing-dominated populations have qualitatively different $N(a)$ during air entrainment. Analysis using the PBE shows that degassing-dominated $\beta$ is a function of $\varLambda (a)$, which has a turbulence-driven regime ($a< a_\varLambda$) and a buoyancy-driven regime ($a>a_\varLambda$). Here, $a_\varLambda$ is the bubble radius where terminal buoyant rise velocity equals $u_{rms}$. Consequently, $N(a)$ exhibits a split power with $\beta (a< a_\varLambda )=-4.\bar {3}$ and $\beta (a>a_\varLambda )=-5.8\bar {3}$ for moderate bubble Reynolds numbers ${{Re}}_b$. For large ${{Re}}_b$, $\beta (a>a_\varLambda )=-4.8\bar {3}$. The DNS strongly confirm these findings for moderate ${{Re}}_b$. By identifying and describing degassing-dominated bubble populations, this work contributes to the understanding and interpretation of broad types of air-entraining problems where degassing plays a relevant role.
The period 1974–1999 were transition years for government school systems in Australia and New South Wales (NSW), where government agencies issued numerous policies and documents to influence and manage education and resultant classroom pedagogy. During those years, many music syllabi were produced for enactment in NSW, placing multiple demands on teacher accountability. This paper forms part of a larger study involving three generations of music teachers representing different career stages and experiences and presents the voices of the group of experienced music teachers (EMTs), exploring the impact of syllabus change, teacher identity, pedagogical skills, and eventual flourishing as confident teachers.