Recent years have seen significant interest in the mechanical properties of clay–polymer hybrids due to their suitability for possible application as sustainable materials in green chemistry. The objective of the present study was to investigate the mechanical properties of clay–polymer hybrids and their corresponding pristine smectite clay minerals. The density functional theory (DFT) method, employing the D3 scheme for corrections of dispersion interactions, was used to calculate elastic constants (Cij) of models of pristine smectites, particularly montmorillonite, beidellite, saponite, and hectorite, and their hybrids built on the polymer poly(2-methyl-2-oxazoline), PMeOx. Following that, the elastic moduli, encompassing the bulk modulus (KVRH), shear modulus (GVRH), Young’s modulus (EVRH), and Poisson’s ratio (ν), were calculated. The results revealed a reduction in elastic constants and elastic moduli following the intercalation of smectite clay minerals with the PMeOx polymer. The findings highlighted a distinctive ranking of mechanical properties among pristine smectite clay minerals and clay–polymer hybrids, with hectorite and its hybrid (Htr-PMeOx) demonstrating better performance compared with saponite, montmorillonite, and beidellite and their respective hybrids.

Persistently rising atmospheric greenhouse gas concentrations challenge dominant Liberal hopes that science and multilateralism might deliver rational, global climate outcomes. Emerging Realist climate approaches that take geopolitics and national interests more seriously have yet to explore Morgenthau’s concern that ‘scientism’ – exaggerated faith in scientific rationality to solve political problems – would lead to disastrous underestimations of power and irrationality. Recently, Realists have mooted ‘solar geoengineering’ designs as a ‘lesser evil’ option to deliberately cool the Earth independently of emissions reductions. However, assessments of solar geoengineering prospects barely factor in Realist concerns, focusing instead on idealised scientific modelling of bio-physical effects and Liberal governance scenarios. To explore how geoengineering techno-science would be ‘translated’ into security assessments, geopolitical logics were elicited through interviews and group discussions with (mainly Arctic-oriented) national security professionals. Security experts reframe solar geoengineering in three significant ways: (a) from a climate ‘global public good’ to a source of geopolitical leverage and disruption; (b) from a risk-reduction tool to a potential source of distrust and escalation; and (c) from a knowledge-deficit problem solvable by more research, to a potential disinformation vector. This expands Realist scholarship on climate change and identifies serious risks to ongoing scientific and commercial pursuit of such technologies.

The discourse of tragedy has significant value in a military context, reminding us of the temptations of hubris, the prevalence of moral dilemmas, and the inescapable limits of foresight. Today, however, this discourse is drawn upon too heavily. Within the tragicized politics of nuclear and drone violence, foreseeable and solvable problems are reconceptualized as intractable dilemmas, and morally accountable agents are reframed as powerless observers. The tragedy discourse, when wrongly applied by policymakers and the media, indulges the very hubris the tragic recognition is intended to caution against. This article clarifies the limits of “tragedy” in the context of military violence and argues for a renewed focus on political responsibility.

In this article I analyze Salvador Allende’s economic program and policies. I argue that the explosion of inflation during his administration (above 1,500% on a six-month annualized measure) was predictable, and I show that the government’s response to it was political. I postulate that runaway inflation generated major disaffection among the middle class and that that unhappiness paved the way to Pinochet’s coup d’état in 1973.

We study the real-valued modified KdV equation on the real line and the circle in both the focusing and the defocusing cases. By employing the method of commuting flows introduced by Killip and Vişan (2019), we prove global well-posedness in Hs for $0\leq s \lt \tfrac{1}{2}$. On the line, we show how the arguments in the recent article by Harrop-Griffiths, Killip, and Vişan (2020) may be simplified in the higher regularity regime $s\geq 0$. On the circle, we provide an alternative proof of the sharp global well-posedness in L2 due to Kappeler and Topalov (2005) and also extend this to the large-data focusing case.

It seems today that a sense of crisis permeates international affairs. From war to pollution to trade and beyond, there is much talk of the disintegration of the settled ways of doing things and fear of what comes next. The twenty-first century has turned sour for many believers in international order. This is not unique in history; order has been on the minds of writers for centuries, from Kant to Carr to Hedley Bull. It is hard to find a period in history when there has not been some sense of crisis. The problem of international order is both a perennial theme and an urgent contemporary concern. The essays in this collection broaden the conversation to consider the ambiguity, complexity, and contradiction within the concept of world order. Order is neither self-evident nor universally agreed upon; to the contrary, it is contested, political, and contingent. Order is a very disorderly idea.

Given a non-negative integer n and a ring R with identity, we construct a hereditary abelian model structure on the category of left R-modules where the class of cofibrant objects coincides with $\mathcal{GF}_n(R)$ the class of left R-modules with Gorenstein flat dimension at most n, the class of fibrant objects coincides with $\mathcal{F}_n(R)^\perp$ the right ${\rm Ext}$-orthogonal class of left R-modules with flat dimension at most n, and the class of trivial objects coincides with $\mathcal{PGF}(R)^\perp$ the right ${\rm Ext}$-orthogonal class of PGF left R-modules recently introduced by Šaroch and . The homotopy category of this model structure is triangulated equivalent to the stable category $\underline{\mathcal{GF}(R)\cap\mathcal{C}(R)}$ modulo flat-cotorsion modules and it is compactly generated when R has finite global Gorenstein projective dimension.

The second part of this paper deals with the PGF dimension of modules and rings. Our results suggest that this dimension could serve as an alternative definition of the Gorenstein projective dimension. We show, among other things, that (n-)perfect rings can be characterized in terms of Gorenstein homological dimensions, similar to the classical ones, and the global Gorenstein projective dimension coincides with the global PGF dimension.

“Imperial Crucible” tells the story of the Aluminum Company of America (Alcoa) from the company’s founding in Pittsburgh in 1888 through the 1950s. Although scholars have long contended that American multinational corporations played a pivotal role in the industrialization of the United States, the building of a global working class, and the transformation of European empires, they have tended to see these stories as distinct, rather than interconnected. In contrast, Imperial Crucible focuses on a single firm to draw together the political-economic, working-class, and imperial history of American business. What the industrialists behind Alcoa built, I argue, was not a multinational but a transimperial corporation.

We introduce the notion of the equivariant covering type of a space X on which a finite group G acts and study its properties. The equivariant covering type measures the size of G-equivariant good covers of X and is thus an extension of the covering type of a space, introduced by Karoubi and Weibel. We show that the equivariant covering type is a G-homotopy invariant and describe its relation with other G-invariants, like the equivariant LS-category, G-genus, and the multiplicative structures of equivariant cohomology theories. We also compute the G-covering type of regular G-graphs, give estimates for orientation-preserving actions on surfaces and for the projectivizations of complex representations of G and cohomology spheres. As an application, we derive estimates of sizes of minimal G-triangulations for various G-spaces.

This article considers a significant but overlooked set of policy developments in the latter half of the twentieth century: the extension of collective bargaining rights to most health care workers, many of whom were formally excluded for three decades under the 1947 Taft-Hartley amendments. Drawing on primary sources including archival records, an exhaustive review of congressional testimony, and rulings from the quasijudicial agency governing private sector industrial relations, this article shows that health care workers did so in two interrelated processes. First, in coordination with the civil rights movement, workers mobilized and used both disruptive and legal social movement tactics. Second, in doing so they drew the state into and revealed its position in the collective bargaining process between workers and health institutions, facilitating what is conceptualized as cross-domain policy feedback. Cross-domain policy feedback occurs when a policy in one domain (e.g., public health spending) influences the politics of a policy in a seemingly separate one (e.g., labor and employment relations). Such effects, this article suggests, are likely to occur when a policy is relatively large in scale, implicates actors with a diverse set of interests, and offers significant ambiguity and discretion in its implementation. Empirically, this article is the first to chart the institutionalization of collective bargaining rights for health care workers, among the largest group of private sector employees in the postindustrial economy. It also offers a new theoretical and conceptual framework through which to study the ways by which public policies reshape political dynamics—an enduring research agenda for students of American politics and policy.