Monetary policy and welfare in a currency union

What are the welfare gains from being in a currency union? I explore this question in the context of a dynamic stochastic general equilibrium model with monetary barriers to trade, local currency pricing and incomplete markets. The model generates a trade off between monetary independence and monetary union. On one hand, distinct national monetary authorities with separate currencies can address business cycles in a country specific way, which is not possible for a single central bank. On the other hand, short-run violations of the law of one price and long-run losses of international trade occur if different currencies are adopted, due to the inertia of prices in local currencies and to the presence of trade frictions. I quantify the welfare gap between these two international monetary arrangements in consumption equivalents over the lifetime of households, and decompose it into the contributions of different frictions. I show that the welfare ordering of alternative currency systems depends crucially on the international correlation of macroeconomic shocks and on the strength of the monetary barriers affecting trade with separate currencies. I estimate the model on data from Italy, France, Germany and Spain using standard Bayesian tools, and I find that the trade off is resolved in favour of a currency union among these countries

Monetary policy and wealth effects with international income transfers

I study how a system of international transfers based on dividend income affects monetary policy in a two-country model with incomplete asset markets. I show that macroeconomic shocks alter international transfer payments and determine cross-border wealth effects on labour supply, output and consumption. The direction of these effects depends on the nature of the underlying disturbance: technology and wage markup shocks cause wealth effects that stabilise consumption relative to output, whereas monetary and price markup shocks cause wealth effects that destabilise it. Numerical work shows that this affects the balance of monetary policy between inflation and output stabilisation

Enhanced second harmonic generation from resonant GaAs gratings

We study second harmonic generation in nonlinear, GaAs gratings. We find large enhancement of conversion efficiency when the pump field excites the guided mode resonances of the grating. Under these circumstances the spectrum near the pump wavelength displays sharp resonances characterized by dramatic enhancements of local fields and favorable conditions for second harmonic generation, even in regimes of strong linear absorption at the harmonic wavelength. In particular, in a GaAs grating pumped at 1064nm, we predict second harmonic conversion efficiencies approximately five orders of magnitude larger than conversion rates achievable in either bulk or etalon structures of the same material.Comment: 8 page

Energy considerations for a superlens based on metal/dielectric multilayers

We investigate the resolution and absorption losses of a Ag/GaP multilayer superlens. For a fixed source to image distance the resolution is independent of the position of the lens but the losses depend strongly on the lens placement. The absorption losses associated with the evanescent waves can be significantly larger than losses associated with the propagating waves especially when the superlens is close to the source. The interpretation of transmittance values greater than unity for evanescent waves is clarified with respect to the associated absorption losses.Comment: to be published in Optics Expres

Single-Phase Motors for Household Applications

Single-phase motors are widely used in household applications. Shaded-pole and split-phase capacitor-start single-phase induction motors are very popular for their ruggedness and their comparatively low cost. Recently, line-start single-phase motors are gaining market shares. However, their superior efficiency and torque density are counterbalanced by the higher cost of the rotor construction due to the magnets. This chapter compares the main structures of single-phase line-start motors, presenting their lumped parameter models and the finite element analysis. The equivalent circuits of the single-phase induction motor and of the line-start permanent magnet are derived. Different rotor structures for single-phase line-start permanent magnet (PM) motors are compared. The finite element method (FEM) is used to compare the characteristics of the motors. Motors with the same stator have been tested. No-load and load tests have been performed and compared to the FEM simulations and to the analytical model. Finally, the performances of line-start PM motors are compared to the shaded-pole induction motors in terms of torque density and efficiency

Transmission function properties for multi-layered structures: Application to super-resolution

We discuss the properties of the transmission function in the k-space for a generic multi-layered structure. In particular we analytically demonstrate that a transmission greater than one in the evanescent spectrum (amplification of the evanescent modes) can be directly linked to the guided modes supported by the structure. Moreover we show that the slope of the phase of the transmission function in the propagating spectrum is inversely proportional to the ability of the structure to compensate the diffraction of the propagating modes. We apply these findings to discuss several examples where super-resolution is achieved thanks to the simultaneous availability of the amplification of the evanescent modes and the diffraction compensation of the propagating modes

APPUNTI PER UN SILLABO DI UN CORSO DI AGGIORNAMENTO SULLA DIDATTICA DELLA LETTURA NELLE SCUOLE SUPERIORI

L’articolo raccoglie alcuni appunti sulla didattica della comprensione del testo scritto nelle scuole superiori. Tratti dalla ricerca educativa sul tema, gli appunti hanno lo scopo di suggerire i contenuti di un corso di aggiornamento per gli insegnanti di italiano. Le informazioni sono selezionate per la didattica agli alunni adolescenti che frequentano i primi anni delle scuole superiori e che dimostrano di incontrare difficoltà nella comprensione dei testi scritti non riconducibili a specifici disturbi dell’apprendimento. Le note riguardano l’esposizione di questi argomenti: le nozioni di linguistica testuale che permettono di riconoscere i dispositivi coesivi in un testo scritto esteso e formale; le implicazioni didattiche che è possibile tratte dalla ricerche di psicologia cognitiva sullo sviluppo della comprensione dei testi scritti; l’insegnamento intenzionale del lessico; la selezione dei testi per gli interventi didattici; la verifica dell’abilità di lettura tramite le prove oggettive e l’uso dei test nella valutazione formativa; e, infine, gli strumenti per analizzare e promuovere la motivazione alla lettura. Nel complesso l’articolo intende ribadire l’importanza di una specifica e continua formazione didattica per gli insegnanti d’italiano.   Notes for the syllabus of a PD course on teaching reading in high schools  The article collects some notes on the teaching of understanding written texts in high schools.  Based on research on this topic, these notes are intended to suggest the content for a PD course for Italian teachers teaching adolescents attending high school and who encounter difficulties in understanding written texts that are not attributable to specific learning disorders.  The notes present textual linguistics concepts that allow students to recognize cohesive devices in an extended and formal written text;  the didactic implications drawn from cognitive psychology research on the development of the understanding of written texts;  intentional teaching of vocabulary;  a selection of texts for teaching interventions;  verification of reading skills through objective tests and the use of tests in assessment;  and finally, the tools to analyze and promote the motivation to read.  Overall, the article reiterates the importance of specific and continuous  training for Italian teachers

Essays in international monetary economics

This dissertation presents two essays in international monetary economics; the unifying theme is the international dimension of monetary policy. I investigate two issues related to the openness of the economy: (i) the implications of external positions for the conduct of macroeconomic stabilisation policy; (ii) the consequences of monetary unification for social welfare under incomplete international markets. The former subject occupies chapter one; the latter occupies chapter two. In the first chapter, "Monetary policy and wealth effects with external positions", I develop a two-country DSGE model to study how financial integration affects the international transmission of shocks and the conduct of monetary policy. If the households of each country receive dividends from foreign firms, macroeconomic disturbances are followed by international wealth effects that transfer consumption across countries. The direction of these effects varies across different types of shocks, as these imply different comovements of macroeconomic variables. As a consequence, the choice of the monetary policy mix is shown to rest on the relative importance of different sources of uncertainty. In the second chapter, "Monetary policy and welfare in a currency union", I explore the welfare cost of abandoning an independent monetary policy to join a currency union, and I investigate what trade gains can outweigh this loss. The consequences of subjecting distinct economies to a single monetary authority are investigated in the context of an open-economy DSGE model with country-specific macroeconomic shocks and incomplete international markets. The dependence of the cost of adopting a single currency on the international synchronisation of business cycles is examined first. Next, the welfare implications of international price misalignments and monetary barriers to trade with separate currencies are considered. Finally, the model is estimated with data from Italy, France, Germany and Spain using standard Bayesian tools. Moderate trade frictions are found to be sufficient for a monetary union to guarantee the same welfare as a regime with national currencies. Under a calibration of these frictions in line with the literature, monetary unification is found to offer positive net welfare gains to all these economies

Wood-Decay Fungi Fructifying in Mediterranean Deciduous Oak Forests: A Community Composition, Richness and Productivity Study.

first_pagesettingsOrder Article Reprints Open AccessArticle Wood-Decay Fungi Fructifying in Mediterranean Deciduous Oak Forests: A Community Composition, Richness and Productivity Study by Ángel Ponce 1,2,Elena Salerni 3,*ORCID,Maria Nives D’Aguanno 4ORCID andClaudia Perini 3,5ORCID 1 Department of Agricultural and Forest Sciences and Engineering, University of Lleida, Av. Alcalde Rovira Roure 191, E-25198 Lleida, Spain 2 Joint Research Unit CTFC—AGROTECNIO—CERCA, Av. Alcalde Rovira Roure 191, E-25198 Lleida, Spain 3 Department of Life Sciences, University of Siena, Via P.A. Mattioli 4, 53100 Siena, Italy 4 Institute of Microbiome and Applied Sciences, Malta Life Sciences Park (LS2.1.12—LS2.1.15), SGN 3000 San Gwann, Malta 5 NBFC, National Biodiversity Future Center, 90133 Palermo, Italy * Author to whom correspondence should be addressed. Forests 2023, 14(7), 1326; https://doi.org/10.3390/f14071326 Received: 5 June 2023 / Revised: 23 June 2023 / Accepted: 25 June 2023 / Published: 28 June 2023 (This article belongs to the Special Issue Diversity, Abundance, and Distribution of Wood-Decay Fungi) Download Browse Figures Review Reports Versions Notes Abstract Deadwood is involved in several important ecological roles, being the fundamental habitat of wood-decay fungi. At the same time, this polyphyletic group of fungi is the principal agent of wood decomposition, regulating the carbon cycle and the food resource for many other organisms. It is known that the diversity and community composition of wood-decay fungi are related to the tree species, decay stage and size of the woody debris in which they are living. Nevertheless, there is a lack of information on Mediterranean Quercus cerris L. forests. In response, we explored how wood-decay fungi colonize different woody types and how the productivity, richness and community composition of these fungi is influenced by the decay stage and size of the deadwood. Our results indicate that the studied groups, i.e., Ascomycetes, Corticioids, Polyporoids and Heterobasidiomycetes responded differently to the woody debris classes. Moreover, we note the high importance of smaller and soft-decayed woody debris for community composition and richness, hosting a great number of species, in addition to the positive effect of the heterogeneity of the woody debris size for wood-decay fungi productivity

Field Localization and Enhancement of Phase Locked Second and Third Harmonic Generation in Absorbing Semiconductor Cavities

We predict and experimentally observe the enhancement by three orders of magnitude of phase mismatched second and third harmonic generation in a GaAs cavity at 650nm and 433nm, respectively, well above the absorption edge. Phase locking between the pump and the harmonics changes the effective dispersion of the medium and inhibits absorption. Despite hostile conditions the harmonics become localized inside the cavity leading to relatively large conversion efficiencies. Field localization plays a pivotal role and ushers in a new class of semiconductor-based devices in the visible and UV ranges