The synthesis of nano-silica is gaining the attention of researchers due to its numerous applications in various fields such as medicine, the food industry, catalysis, agriculture and construction, amongst others, because of its unique physicochemical features. However, achieving its facile synthesis and finding inexpensive source material that is locally available requires further exploration for its large-scale production. This paper reports the synthesis and characterization of nano-silica from locally available laterite clay using the sol-gel method. The product was analysed using X-ray florescence, X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy and transmission electron microscopy. It was observed that the product was spherical, agglomerated and amorphous in nature. The obtained nano-silica was found to have 97% and 95% purity for sodium hydroxide and potassium hydroxide, respectively. The synthesized nano-silica is expected to play pivotal role as a pozzolanic activator in the construction industry.

Bioethicists aim to provide moral guidance in policy, research, and clinical contexts using methods of moral analysis (e.g., principlism, casuistry, and narrative ethics) that aim to satisfy the constraints of public reason. Among other objections, some critics have argued that public reason lacks the moral content needed to resolve bioethical controversies because discursive reason simply cannot justify any substantive moral claims in a pluralistic society. In this paper, the authors defend public reason from this criticism by showing that it contains sufficient content to address one of the perennial controversies in bioethics—the permissibility and limits of clinician conscientious objection. They develop a “reasonability view” grounded in public reason and apply it to some recent examples of conscientious objection.

This article presents an analysis of speech rhythm in Tongan English, an emergent variety spoken in the Kingdom of Tonga. The normalised Pairwise Variability Index (nPVI-V) is used to classify the variety and determine the social and stylistic constraints on variation in a corpus of conversational and reading passage data with 48 speakers. Findings reveal a greater tendency towards stress-timing in speakers of the emergent local elite, characterised by white-collar professions and high levels of education, and those with a high index of English use. Variation is discussed as a consequence of proficiency, language contact and L1 transfer. An acoustic analysis of vowels in unstressed syllables of eight speakers confirms that lack of vowel centralisation (higher F1) is an underlying linguistic mechanism leading to more syllable-timed speech. Stark interspeaker variation was identified, highlighting the need to proceed with caution when classifying L2 Englishes based on speech rhythm.

We introduce three measures of complexity for families of sets. Each of the three measures, which we call dimensions, is defined in terms of the minimal number of convex subfamilies that are needed for covering the given family. For upper dimension, the subfamilies are required to contain a unique maximal set, for dual upper dimension a unique minimal set, and for cylindrical dimension both a unique maximal and a unique minimal set. In addition to considering dimensions of particular families of sets, we study the behavior of dimensions under operators that map families of sets to new families of sets. We identify natural sufficient criteria for such operators to preserve the growth class of the dimensions. We apply the theory of our dimensions for proving new hierarchy results for logics with team semantics. To this end we associate each atom with a natural notion or arity. First, we show that the standard logical operators preserve the growth classes of the families arising from the semantics of formulas in such logics. Second, we show that the upper dimension of $k+1$-ary dependence, inclusion, independence, anonymity, and exclusion atoms is in a strictly higher growth class than that of any k-ary atoms, whence the $k+1$-ary atoms are not definable in terms of any atoms of smaller arity.

We present new stable oxygen and carbon isotope composite records (δ18O, δ13C) of speleothems from Sandkraal Cave 1 (SK1) on the South African south coast for the time interval between 104 and 18 ka (with a hiatus between 48 and 41 ka). Statistical comparisons using kernel-based correlation analyses and semblance analyses based on continuous wavelet transforms inform the relationships of the new speleothem records to other proxies and their changes through time. Between 105 and ~70 ka, changes of speleothem δ18O values at SK1 are likely related to rainfall seasonality. Variations of δ13C values are associated with changes of vegetation density, prior carbonate precipitation (PCP), CO2 degassing in the cave, and possibly variations of the abundance of C3 and C4 grasses in the vegetation. The relationships of δ18O with other proxies shift between ~70 and 48 ka (Marine Isotope Stages 4–3) so that both stable isotope records now reflect CO2 degassing, evaporation, and PCP. Similar relationships also continue after the hiatus for the deposition phase between 42 and 18 ka. Our findings support modeling results suggesting drier conditions in the study area when the Southern Hemisphere westerlies are shifted north and the paleo–Agulhas Plain is exposed.

In the aftermath of World War II, eugenics and the pseudoscientific base used to justify its practices are generally understood to have phased off the scene. If, however, eugenics never actually disappeared but has been persistent, and in turn becomes one of the best explanations for mass incarceration today, what role did Christianity—especially Evangelicalism—play in this unprecedented moment of imprisonment? Building on legal scholarship identifying the significant role of eugenic philosophy that manifests in penal policy and ongoing phenomena into the early twenty-first century, this article examines key figures in the backdrop of eugenics’ particular early developments, and leading figures—namely, Billy Graham and Prison Fellowship’s Chuck Colson—whose ministries operated in close proximity to the prison during the latter twentieth century and especially over the past fifty years as incarceration rates skyrocketed. After examining several important theological tenets reflected within Evangelicalism that are compatible with eugenic logic, a critical approach is developed drawing from more robust theological considerations that if appropriated earlier might have found evangelicals resisting the mass incarceration building efforts rather than supporting them.

Can Rawlsian public reason sufficiently justify public policies that regulate or restrain controversial medical and technological interventions in bioethics (and the broader social world), such as abortion, physician aid-in-dying, CRISPER-cas9 gene editing of embryos, surrogate mothers, pre-implantation genetic diagnosis of eight-cell embryos, and so on? The first part of this essay briefly explicates the central concepts that define Rawlsian political liberalism. The latter half of this essay then demonstrates how a commitment to Rawlsian public reason can ameliorate (not completely resolve) many of the policy disagreements related to bioethically controversial medical interventions today. The goal of public reason is to reduce the size of the disagreement by eliminating features of the disagreement that violate the norms of public reason. The norms of public reason are those norms that are politically necessary to preserve the liberal, pluralistic, democratic character of this society. What remains is reasonable disagreement to be addressed through normal democratic deliberative processes. Specific issues addressed from a public reason perspective include personal responsibility for excessive health costs, the utility of a metaphysical definition of death for organ transplantation, and the moral status of excess embryos generated through IVF and/or their use in medical research.