High-temperature non-equilibrium effects are prominent in scramjet nozzle flows at high Mach numbers. Hence, the thermochemical non-equilibrium gas model incorporating the vibrational relaxation process of molecules in the hydrocarbon-air reaction is developed to numerically simulate the flow of a hydrocarbon fuel scramjet nozzle at Mach 10. Besides, the results computed by the models of the thermally perfect gas, chemically non-equilibrium gas, and thermally non-equilibrium chemically frozen gas are applied for comparative studies. Results indicate that chemical non-equilibrium effects are more significant for the flow-field structure and parameters compared to thermal non-equilibrium effects. Meanwhile, vibrational relaxation and chemical reactions interact in the flow-field. The heat released from the chemical reactions in the flow-field of the thermochemical non-equilibrium gas model makes the thermal non-equilibrium effects weaker compared to the thermally non-equilibrium chemically frozen gas model; the chemical reactions in the thermochemical non-equilibrium gas model are more intense than in the chemically non-equilibrium gas model. Due to the slow relaxation of vibrational energy, the thermal non-equilibrium models predicted nozzle thrust lower than the thermal equilibrium models by approximately 1.11% to 1.33%; when considering the chemical reactions, the chemical non-equilibrium models predicted nozzle thrust higher than the chemical frozen models by approximately 7.30% to 7.54%. Hence, the structural design and performance study of the high Mach numbers scramjet nozzle must consider thermochemical non-equilibrium effects.

The values of the signal-to-noise ratio are determined, at which the method of processing X-ray diffraction data reveals reflections with intensity less than the noise component of the background. The possibilities of the method are demonstrated on weak reflections of α-quartz. The method of processing X-ray diffraction data makes it possible to increase the possibilities of X-ray phase analysis in determining the qualitative phase composition of multiphase materials with a small (down to 0.1 wt.%) content of several (up to eight) phases.

A recent article of Chernikov, Hrushovski, Kruckman, Krupinski, Moconja, Pillay, and Ramsey finds the first examples of simple structures with formulas which do not fork over the empty set but are universally measure zero. In this article we give the first known simple $\omega $-categorical counterexamples. These happen to be various $\omega $-categorical Hrushovski constructions. Using a probabilistic independence theorem from Jahel and Tsankov, we show how simple $\omega $-categorical structures where a formula forks over $\emptyset $ if and only if it is universally measure zero must satisfy a stronger version of the independence theorem.

The property of countable metacompactness of a topological space gets its importance from Dowker’s 1951 theorem that the product of a normal space X with the unit interval $[0,1]$ is again normal iff X is countably metacompact. In a recent paper, Leiderman and Szeptycki studied $\Delta $-spaces, which is a superclass of the class of countably metacompact spaces. They proved that a single Cohen real introduces a ladder system $ L$ over the first uncountable cardinal for which the corresponding space $X_{ L}$ is not a $\Delta $-space, and asked whether there is a ZFC example of a ladder system $ L$ over some cardinal $\kappa $ for which $X_{ L}$ is not countably metacompact, in particular, not a $\Delta $-space. We prove that an affirmative answer holds for the cardinal $\kappa =\operatorname {\mathrm {cf}}(\beth _{\omega +1})$. Assuming $\beth _\omega =\aleph _\omega $, we get an example at a much lower cardinal, namely $\kappa =2^{2^{2^{\aleph _0}}}$, and our ladder system L is moreover $\omega $-bounded.

The later career of British prehistorian Peggy Piggott, latterly Guido, is evaluated in this article, in a bid to further develop our understanding of women's participation in twentieth-century British archaeology. After WWII, when her husband Stuart Piggott was appointed to the Abercromby Chair in Edinburgh, she worked to assist his role. By the early 1950s, she had co-directed and published eight hillfort excavations, advancing our understanding of prehistoric architecture before the advent of radiocarbon dating. The authors consider Peggy Piggott's contribution as a fieldworker, promoting open-area excavation and influencing the next generation. We also consider her thinking, as an early advocate for continuity and Childe's diffusionism, in contrast to the invasionist views of Christopher Hawkes and Stuart Piggott. The authors reflect on the role her marriage played in enabling and restricting her career, her work in 1960s Italy, her expertise in ancient glass beads, and her activity in retirement.

Given a cocycle on a topological quiver by a locally compact group, the author constructs a skew product topological quiver and determines conditions under which a topological quiver can be identified as a skew product. We investigate the relationship between the ${C^*}$-algebra of the skew product and a certain native coaction on the ${C^*}$-algebra of the original quiver, finding that the crossed product by the coaction is isomorphic to the skew product. As an application, we show that the reduced crossed product by the dual action is Morita equivalent to the ${C^*}$-algebra of the original quiver.

This paper defends an interpretation of Fanon's theory of recognition as revolving around his claim that we have a basic right to demand human behaviour from the other. Developing key Hegelian ideas in a novel direction, I argue that Fanon's theory of recognition employs a concretely universal concept of humanity as a normative orientation for establishing what he calls a ‘world of reciprocal recognitions’, which he equates with the creation of a ‘human reality’. In the first section, I take up the three passages from Hegel's Phenomenology of Spirit cited by Fanon in Black Skin, White Masks to outline three key features of Fanon's theory of recognition. In section two, I argue that there are three senses of ‘universal humanity’ operative in Fanon's work: a false universal, an abstract universal, and a concrete universal. Whereas the first two are critical, pejorative uses, the third provides the normative orientation for his account of recognition and social struggle. In the third section, I show how Fanon combines features of Hegel's concrete universal with features of Sartre's existential humanism in order to avoid an essentialist or ahistorical approach to human nature. Specifically, I argue that the ideas of self-transcendence and a universal human condition shed light on what Fanon refers to as the right of reciprocal recognition to demand human behaviour from the other, and our one human duty to not renounce our freedom.

The invasive pea leaf weevil, Sitona lineatus (Linnaeus) (Coleoptera: Curculionidae), damages field peas, Pisum sativum Linnaeus (Fabaceae), and faba beans, Vicia faba Linnaeus (Fabaceae), on the Canadian prairies. We used semiochemical-baited pitfall traps to monitor and detect S. lineatus range expansion and capture associated predaceous ground beetles (Coleoptera: Carabidae) in pulse-growing regions across Alberta. Traps captured male and female S. lineatus in all pulse-growing regions in the spring and fall, including a first record of S. lineatus in the Peace River region of northwestern Alberta. Pheromone-baited traps captured more weevils than unbaited traps did, and the addition of host plant volatiles did not increase the catch. More weevils were captured in traps in pea fields compared to in faba bean fields. Rubber septa lures released more pheromones and attracted a similar number or more weevils to traps than microcentrifuge tube lures did. Ground beetle capture was not affected by semiochemical baits targeting S. lineatus. Ground beetle diversity varied by region and collection period, but the most frequently collected species was Pterostichus melanarius, a potential predator of S. lineatus. This study shows that pitfall traps baited with rubber septa pheromone lures can be used to monitor new and expanding S. lineatus populations, as well as potential natural enemy communities.

Research on mobile-assisted language learning (MALL) has revealed that high rates of attrition among users can undermine the potential benefits of this learning method. To explore this issue, we surveyed 3,670 adult MALL users based on the Unified Theory of Acceptance and Use of Technology (UTAUT) and also conducted an in-depth analysis of their historical app usage data. The results of hierarchical k-means cluster analysis and recurrent event survival analysis revealed three major findings. First, three distinct profiles of learners were characterized by different MALL acceptance and engagement experiences. Second, those with greater MALL acceptance displayed more intense, frequent, and durable app usage (behavioral engagement). Lastly, high levels of MALL acceptance were associated with more frequent pauses in app usage but also (a) longer active usage, (b) shorter breaks before returning to the app, and, ultimately, (c) fewer dropouts. We argue that persistence is a multidimensional process involving cyclical phases of engagement, disengagement, dormancy, and reengagement, with each aspect, like intensity, frequency, and duration, building up cumulatively over time. Implications for promoting persistent MALL engagement are discussed.

We obtain asymptotic formulas for the number of matrices in the congruence subgroup

$$\begin{align*}\Gamma_0(Q) = \left\{ A\in\operatorname{SL}_2({\mathbb Z}):~c \equiv 0 \quad\pmod Q\right\}, \end{align*}$$

Contemplating how the familiar trope of the “bad Black mother” is used to surveil, punish, and scorn Black maternal subjects this article considers how good motherhood is at once aspirational and coercive for Black mothers who are disciplined by the ever looming threat of badness and the unattainable promise of goodness. Stretching contemporary Black feminist analyses of how Black maternal revolt against anti-Black logics can be witnessed through forms of mortal sacrifice that secure future Black life, this article troubles ideals of sacrifice through an auto-ethnographic reading of maternal death as a respite from the continuous labors of goodness for the subject that tires under the relentless force of racism and its anticipations of bad Black motherhood. Badness is then explored, through personal narrative, as a form of affective resistance against the drudgery of willing towards goodness as the maternal refuses to discipline their discontent.

Tropical drylands are characterized by extreme environmental conditions that, coupled with anthropogenic habitat degradation, can limit the occurrence of native species. Species that are most sensitive to these pressures may be prone to disappear in the context of climate change. In this study, we evaluated the influence of environmental and anthropogenic variables on the occurrence of large mammals and birds at the Tatacoa Desert, an arid region in central Colombia. We tested the relationship between the magnitude of the species’ responses to environmental, human-related variables and to body mass, and percentage of carnivory. Overall, we found a positive association between forest cover and the occupancy of the largest mammals (> 8kg), negative associations between solar radiation and human footprint with individual species occupancy, and a positive association of species occupancy with distance to touristic sites. Our results suggest that the largest and/or more carnivore species may be affected positively by forest cover and negatively by intense solar radiation highlighting the consequences of the increasing process of desertification on large mammals and birds at the upper Magdalena River basin of Colombia under the current scenario of global climate change.

Pi-d2, which encodes a potential serine-threonine receptor-like kinase (RLK) membrane-spanning protein consisting of 825 amino acids, confers resistance to Magnaporthe oryzae strain ZB15 via an unidentified recognition mechanism. In this study, the Pid2 alleles of 303 rice (O. sativa) varieties from China's Yunnan region were amplified and sequenced in order to produce 24 haplotypes and 16 translation variants. Six of twenty-four alleles possessing the resistant site at the 441st amino acid were chosen for evaluating blast resistance by transforming into the blast-vulnerable rice variety Nipponbare. After being infected with 11 strains of M. oryzae, all transgenic lines exhibited resistance to ZB-15, whereas resistance to other strains varied. Notably, Pi-d2_H23 and Pi-d2_H24 exhibited resistance to all M. oryzae strains tested, indicating that these two alleles may have a broader resistance spectrum to M. oryzae. Alignment of these alleles’ amino acid sequences revealed that the differences in blast resistance spectra were primarily related to the amino acids present in the PAN domain at position 363 (valine/alanine). These findings suggested that the two extracellular signal recognition domains of PI-D2, B-lectin and PAN, may play a role in the identification of M. oryzae effectors. The present results provide insight into the mechanism of interaction between RLKs and M. oryzae.

The high-pressure behaviour of inderborite [ideally CaMg[B3O3(OH)5]2(H2O)4⋅2H2O, space group C2/c with a ≈ 12.14, b ≈ 7.43, c ≈ 19.23 Å and β ≈ 90.3° at room conditions] has been studied by two in situ single-crystal synchrotron X-ray diffraction experiments up to ~10 GPa, using He as pressure-transmitting fluid. Between 8.11(5) and 8.80(5) GPa, inderborite undergoes a first-order phase transition to its high-pressure polymorph, inderborite-II (with a ≈ 11.37, b ≈ 6.96, c ≈ 17.67 Å, β ≈ 96.8° and ΔV ≈ 7.0%, space group unknown). The isothermal bulk modulus (KV0 = β−1P0,T0, where βP0,T0 is the volume compressibility coefficient) of inderborite was found to be KV0 = 41(1) GPa. The destructive nature of the phase transition prevented any structure resolution of inderborite-II or even the continuation of the experiments at pressures higher than 10.10(5) GPa. In the pressure range 0–8.11(5) GPa, the compressional anisotropy of inderborite, indicated by the ratio between the principal components of the Eulerian finite unit-strain ellipsoid, is ɛ1:ɛ2:ɛ3 = 1.4:1.05:1. The deformation mechanisms at the atomic scale in inderborite are here described. Our findings support the hypothesis of a quasi-linear correlation between the total H2O content and P-stability range in hydrated borates, as the pressure at which inderborite undergoes the phase transition falls in line with most of the hydrate borates studied at high-pressure so far.

The Ethiopian core collection of the USDA-Agriculture Research Service, National Plant Germplasm System (NPGS) includes 376 accessions and a genomic characterization that revealed 151,210 single nucleotide polymorphisms. This collection, however, lacks phenotypic characterization for several important agriculture traits. A total of 330 accessions from this NPGS Ethiopian core set were evaluated for grain mould resistance response across four tropical environments. Most of the accessions in the NPGS Ethiopian collection showed susceptibility to grain mould based on the low emergence rate and high seed deterioration observed in the seeds. The population structure of the collection was not related to grain mould resistance response suggesting this germplasm originated in regions with low disease pressure. The analysis identified two accessions with high emergence (PI 457867 and PI 454221) and three (PI 455036, PI 455213 and PI 330821) with low seed degradation. Genome-wide association analysis found genomic regions in chromosome 1, 3 and 8 associated with the observed grain mould resistance variation. Candidate gene analysis within these three loci identified diseases resistance genes involved in pathogen recognition and signalling cascades of the plant immunity system. These five NPGS Ethiopian accessions are candidates for use in a pre-breeding germplasm programme to develop improved germplasm with grain mould resistance.

Path planning for the unmanned aerial vehicle (UAV) is to assist in finding the proper path, serving as a critical role in the intelligence of a UAV. In this paper, a path planning for UAV in three-dimensional environment (3D) based on enhanced gravitational search algorithm (EGSA) is put forward, taking the path length, yaw angle, pitch angle, and flight altitude as considerations of the path. Considering EGSA is easy to fall into local optimum and convergence insufficiency, two factors that are the memory of current optimal and random disturbance with chaotic levy flight are adopted during the update of particle velocity, improving the balance between exploration and exploitation for EGSA through different time-varying characteristics. With the identical cost function, EGSA is compared with seven peer algorithms, such as moth flame optimization algorithm, gravitational search algorithm, and five variants of gravitational search algorithm. The experimental results demonstrate that EGSA is superior to the seven comparison algorithms on CEC 2020 benchmark functions and the path planning method based on EGSA is more valuable than the other seven methods in diverse environments.

We highlight an important but overlooked characteristic of financial fragility: “Fragile” stocks command higher liquidity. This reduces their sensitivity to corporate actions with price impact and affects the firms’ incentives to engage in such actions. We show that fragile firms have lower share repurchases, issue more equity, and invest more. We establish causality by relating changes in corporate actions to exogenous changes in fragility induced by mergers of asset managers. Our results suggest that financial fragility has direct but unexpected real implications for corporate actions.