A\mathcal A-compact mappings

For a fixed Banach operator ideal $\mathcal A$, we use the notion of $\mathcal A$-compact sets of Carl and Stephani to study $\mathcal A$-compact polynomials and $\mathcal A$-compact holomorphic mappings. Namely, those mappings $g\colon X\rightarrow Y$ such that every $x \in X$ has a neighborhood $V_x$ such that $g(V_x)$ is relatively $\mathcal A$-compact. We show that the behavior of $\mathcal A$-compact polynomials is determined by its behavior in any neighborhood of any point. We transfer some known properties of $\mathcal A$-compact operators to $\mathcal A$-compact polynomials. In order to study $\mathcal A$-compact holomorphic functions, we appeal to the $\mathcal A$-compact radius of convergence which allows us to characterize the functions in this class. Under certain hypothesis on the ideal $\mathcal A$, we give examples showing that our characterization is sharp.Comment: 21 Pages; Accepted in RACSA

Upper-atmosphere Aerosols: Properties and Natural Cycles

The middle atmosphere is rich in its variety of particulate matter, which ranges from meteorite debris, to sulfate aerosols, to polar stratospheric ice clouds. Volcanic eruptions strongly perturb the stratospheric sulfate (Junge) layer. High-altitude 'noctilucent' ice clouds condense at the summer mesopause. The properties of these particles, including their composition, sizes, and geographical distribution, are discussed, and their global effects, including chemical, radiative, and climatic roles, are reviewed. Polar stratospheric clouds (PSCs) are composed of water and nitric acid in the form of micron-sized ice crystals. These particles catalyze reactions of chlorine compounds that 'activate' otherwise inert chlorine reservoirs, leading to severe ozone depletions in the southern polar stratosphere during austral spring. PSCs also modify the composition of the polar stratosphere through complex physiocochemical processes, including dehydration and denitrification, and the conversion of reactive nitrogen oxides into nitric acid. If water vapor and nitric acid concentrations are enhanced by high-altitude aircraft activity, the frequency, geographical range, and duration of PSCs might increase accordingly, thus enhancing the destruction of the ozone layer (which would be naturally limited in geographical extent by the same factors that confine the ozone hole to high latitudes in winter). The stratospheric sulfate aerosol layer reflects solar radiation and increases the planetary albedo, thereby cooling the surface and possibly altering the climate. Major volcanic eruptions, which increase the sulfate aerosol burden by a factor of 100 or more, may cause significant global climate anomalies. Sulfate aerosols might also be capable of activating stratospheric chlorine reservoirs on a global scale (unlike PCSs, which represent a localized polar winter phenomenon), although existing evidence suggests relatively minor perturbations in chlorine chemistry. Nevertheless, if atmospheric concentrations of chlorine (associated with anthropogenic use of chlorofluorocarbons) continue to increase by a factor of two or more in future decades, aircraft emissions of sulfur dioxide and water vapor may take on greater significance

Buddhism and modernity: in the margin of Donald S. Lopez Jr.’S “Buddhism and Science”

The present article aims at setting the issue of the relationship between Buddhism and science in a historical and philosophical frame wider than that took into account by the international scholarship so far. The historical point of view allows us to conclude that the narrative that connects Buddhism with science is not based on features intrinsic to Buddhist thought. In fact, such narrative prospered thanks to the development of a dialectic between science and religion typical of the 18th and 19th centuries. The philosophical point of view allows us to conclude that such narrative is backed by a metaphysical-like thought that denies the specificity of both science and Buddhism

Empirical investigation on labour market interactions in an enlarged Europe

This paper proposes an empirical assessment of economic interactions between the labour markets of the integrating EU over the period of time 1995–2005. Drawing on recently made available industry statistics, we provide a sector level study (13 tradable sectors, including manufacturing and services), analysing the contemporary evolution of domestic and trade partners’ employment levels. Given the intensification of trade relations as a result of ongoing integration process, we build a sector-specific measure of economic interdependency, based on information on labour markets’ performance and weighted by the magnitude of intra-EU trade flows (imports). The estimates of a dynamic empirical model confirm the interactions between employment levels in different Member States. Domestic employment in NMS-5 is rather positively affected by the expansion of labour markets in other EU’s trade partners (domestic employment levels in NMS-5 countries improve in parallel to the increase in foreign tradable sectors’ employment). The opposite holds true for EU-15 domestic labour markets that are rather challenged by the expansion of tradable sectors in their EU trade partners.EU integration, labour markets, trade

Skyrmion States In Chiral Liquid Crystals

Within the framework of Oseen-Frank theory, we analyse the static configurations for chiral liquid crystals. In particular, we find numerical solutions for localised axisymmetric states in confined chiral liquid crystals with weak homeotropic anchoring at the boundaries. These solutions describe the distortions of two-dimensional skyrmions, known as either \textit{spherulites} or \textit{cholesteric bubbles}, which have been observed experimentally in these systems. Relations with nonlinear integrable equations have been outlined and are used to study asymptotic behaviors of the solutions. By using analytical methods, we build approximated solutions of the equilibrium equations and we analyse the generation and stabilization of these states in relation to the material parameters, the external fields and the anchoring boundary conditions.Comment: 13 pages, 13 figures, Conference: PMNP 2017: 50 years of IST, Gallipoli (LE)- Italy June 17-24, 201

King post truss as a motif for internal structure of (meta)material with controlled elastic properties

One of the most interesting challenges in the modern theory of materials consists in the determination of those microstructures which produce, at the macro-level, a class of metamaterials whose elastic range is many orders of magnitude wider than the one exhibited by ‘standard’ materials. In Dell’Isola et al. (2015 Zeitschrift für angewandte Mathematik und Physik 66, 3473- 3498. (doi: 10.1007/s00033-015-0556-4)), it was proved that, with a pantographic microstructure constituted by ‘long’ microbeams it is possible to obtainmetamaterials whose elastic range spans up to an elongation exceeding 30%. In this paper, we demonstrate that the same behaviour can be obtained bymeans of an internal microstructure based on a king post motif. This solution shows many advantages: it involves only microbeams; all constituting beams are undergoing only extension or compression; all internal constraints are terminal pivots. While the elastic deformation energy can be determined as easily as in the case of long-beam microstructure, the proposed design seems to have obvious remarkable advantages: it seems to be more damage resistant and therefore to be able to have a wider elastic range; it can be realized with the same three-dimensional printing technology; it seems to be less subject to compression buckling. The analysis which we present here includes: (i) the determination of Hencky-type discrete models for king post trusses, (ii) the application of an effective integration scheme to a class of relevant deformation tests for the proposed metamaterial and (iii) the numerical determination of an equivalent second gradient continuum model. The numerical tools which we have developed and which are presented here can be readily used to develop an extensive measurement campaign for the proposed metamaterial

Measuring and Analyzing the Liquidity of the Italian Treasury Security Wholesale Secondary Market

Although its importance, only recently the issue of liquidity in Treasury markets has received greater attention. We survey the literature about market liquidity and liquidity measures, and we put forward new measures. The aim is to provide a description of the liquidity of the Italian wholesale secondary market, which we describe thoroughly. We apply a large set of measures on a unique dataset, which gives us a complete view of the market. Even though the market provides an amount of liquidity that fits the market needs, the quality of the order book is low, and despite the presence of a large number of market makers, the degree of competition among them is not very high. Moreover, no clear and general relationship emerges between trading and order book measures. Indeed, even though trading activity is higher for on-the-run securities with respect to the off-the-run securities, there is not a sharp difference in terms of liquidity of the order book between them. In this case market regulation plays an important role. Finally, we investigate how long it takes for a new issue to become the benchmark for its segment. Our evidence shows that some modifications of the issuance policy in order to have a larger outstanding since the first auction could help securities in gaining earlier their benchmark status, especially in case of 10-year BTPs.Liquidity, liquidity measures, Government securities, market microstructure, benchmark status.