1,721,013 research outputs found
L'insostenibile leggerezza dei Bund tedeschi nell'area Euro
No full textLa letteratura economica e quella dei principali organismi internazionali sui tassi di rendimento dei debiti sovrani dell’area euro non sembra aver preso in considerazione il tema in un ottica di intermediazione finanziaria, sul terreno suo proprio. In questo articolo si tenta di colmare questa lacuna con analisi quantitative e di scenario incentrata sui quattro maggiori paesi dell’area Euro (Germania, Italia, Francia e Spagna).
Le specificazioni adottate sono basate su una interazione tra effetti di breve periodo (modelli alla Capm di un ipotetico fondo di investimenti in titoli sovrani) e determinanti di medio lungo periodo legate ai fondamentali macro (debito e deficit su PIL).
Il fitting migliore rispetto ai modelli consensus deriva da Beta variabili di portafoglio che simulano i comportamenti divergenti tra tassi tedeschi e italiani, spagnoli e francesi (gli spread), non escludendo l’impatto dei fondamentali alla BCE in un’ottica di medio periodo. Dalle simulazioni, per la fine dell’anno in corso e in prospettiva per il 2014, sembrano emergere alcuni
interrogativi in merito alla efficacia delle misure di riequilibrio economico-finanziario suggerite dalla letteratura e/o dagli organismi internazionali nell’area euro: un rialzo dei tassi dei Bund tedeschi accoppiato ad un riallineamento delle politiche di bilancio simili quelle realizzate nei passati anni da Italia e Spagna ed in corso in Francia sembrerebbero, dalle proiezioni, implicare effetti di progressivo superamento dell’attuale stasi, da una parte, e di riduzione del rischio di break up dell’aera euro, dall'altra.Both the economic literature and the International Organizations Report’s on the sovereign debts yield’s in the Euro Area do not seem to have covered the issue on the asset allocation specific ground. This paper attempts to fill this gap with naïve quantitative analyses and scenario’s projections, focusing on the four major Eurozone countries (Germany, Italy, France and Spain). The approaches adopted are centered on the interactions between short-term behaviors (CAPM type models for a hypothetical fund investments in sovereign bonds) and medium- long behaviors linked to the macro fundamentals (debt and deficit on GDP). To some extent, the results fit better than obtained from current models (consensus models): portfolio time-varying Beta’s captures the divergent behaviors of the rates between Germany, Italy, France and Spain coupled with the impact of single countries macro-fundamentals. The various scenarios prospects covering the end of 2013 and the beginning of the 2014 exclude a realignment of South Countries spreads without a substantial increase of German rates (roughly speaking, the same rates of the Treasury Bills). Furthermore, 200 basis points spread between Italian Bond and benchmark Deutschland Bond is foreseeable only by (literature’s counterintuitive) measures to comprise Germany debt and deficit, similar to those adopted by Italy and Spain, and in progress in France. In all et all and finally, the results suggest a focus on the risks due to the effect of a dramatic reduction German bonds price, i.e. the risks that the asset purchases of German bonds (today a sort of safe haven and insurance for the other bonds of the euro area) may to shrink due to some shock/expectations changes of a big international investor and subsequent domino effects
Ghetti e campi. La produzione istituzionale di marginalità abitativa nelle campagne siciliane
No full text
Virtual element method for computational homogenization of composite and heterogeneous materials
Full text linkIn this study, a two-dimensional multi-region framework, based on the use of the Virtual Element Method (VEM), is developed for computational materials homogenization and applied to different classes of widely employed heterogeneous materials. The VEM has recently emerged as a powerful generalisation of the Finite Element Method capable of dealing with very general polygonal mesh elements, including non-convex or highly distorted elements. Such features are appealing for the treatment of problems whose analysis domains present complex or statistical morphological features, which would generally require careful and time-consuming mesh/data preparation and regularization. In this work, the lowest-order VEM for two-dimensional elastostatics is employed for the homogenization of polycrystalline materials and unidirectional fibre-reinforced composites. In both cases, artificial micro-morphologies are usually generated resorting to automatic algorithms aimed at approximating/reproducing the statistical microscopic features of real materials. In such a context, the likely presence of morphological irregularities, and subsequent mesh distortions, usually requires caution and the employment of sophisticated mesh regularization procedures. The study demonstrates how the inherent features of the VEM can be conveniently exploited for such classes of problems, as the method allows the relaxation of the requirements on the mesh quality, yet providing accurate numerical results
Coupled VEM–BEM Approach for Isotropic Damage Modelling in Composite Materials
No full textNumerical prediction of composite damage behaviour at the microscopic level is still a challenging engineering issue for the analysis and design of modern materials. In this work, we document the application of a recently developed numerical technique based on the coupling between the Virtual Element Method (VEM) and the Boundary Element Method (BEM) within the framework of continuum damage mechanics (CDM) to model the in-plane damage evolution characteristics of composite materials. BEM is a widely adopted and efficient numerical technique that reduces the problem dimensionality due to its underlying formulation. It substantially simplifies the pre-processing stage and decreases the computational effort without affecting the solution's accuracy. VEM is a recent generalization to general polygonal mesh elements of the Finite Element Method that ensures noticeable simplification in the data preparation stage of the analysis, notably for computational micro-mechanics problems, whose analysis domain often features complex geometries. The numerical technique has been applied to artificial microstructures, representing the transverse section of composite material with stiffer circular-shaped inclusions embedded in a softer matrix. BEM is used to model the inclusions that are supposed to behave within the linear elastic range, while VEM is used to model the surrounding matrix material, developing nonlinear behaviours. Numerical results are reported and discussed to validate the proposed method
The Emergency Management of Migration and Agricultural Workforce during the Pandemic The Contradictory Outcomes of the 2020 Amnesty Law
No full textThe chapter aims to illustrate the effects of the Covid pandemic and, in particular, of the of amnesty law passed by the Italian government in May 2020 for migrants working in agriculture, highlighting the continuity of the latter measure with the previous policies regulating migration and agricultural labour. For decades, these policies have managed both international migrations and domestic mobility of the seasonal labour force through an emergency approach. The chapter resorts on data collected through statistics, interviews and participant observation inside informal settlements in the South of Italy. In conclusion, we argue that the health emergency accelerates the resort to administrative and bureaucratic emergency practices in the management of migrations, thus contributing to the reproduction of an emergency frame, that relegates labourers to the role of ‘victims of exploitation’, and at the same time regulates their possibility of movement and their employment opportunities
The potential evolution of the supply of credit to the productive chain: A focus on Italy and the Regional Sardinian economy
No full textThe analysis performed in this chapter aims to define the dynamics of the demand for and supply of credit for the regional Sardinian economy, compared to other Italian regions, during the period from 2002 to 2013. Typical methodologies for the analysis of financial series (velocity and momentum indicators), as well as the methodologies for spatial analysis (principal component analysis, cluster analysis and specialisation indexes), have been employed for this purpose. Based on a sample of macro- and micro-data – the latter being related to 19,000 firms – our analysis highlights the existence of some high-performing industry segments, such as Lodging, Food and Food Services (LFFS). Overall, our results show undeniable criticalities with regard to the allocative efficiency of banks. For the most recent years of the sample, banks severely shrank the credit supply towards the most dynamic sectors, exhibiting instead an increasing credit specialisation towards weaker performing sectors, which are characterised by high rates of impaired loans
Esperienze di attaccamento e competenza emotiva nei minori abusanti
No full textLe relazioni interpersonali consentono ai bambini di apprendere quale significato attribuire alle emozioni, nonché quali modalità socialmente accettabili utilizzare; tra le variabili in grado di spiegare il comportamento dei minori abusanti appaiono particolarmente significative la scarsa competenza emotiva e l’insicurezza del legame di attaccamento. La valutazione della storia personale e dell’Adult Attachment Interview di due utenti dell’Ufficio di Servizio Sociale per i Minorenni (USSM) di Palermo accusati di un reato sessuale ha permesso di evidenziare una mancanza di intimità nelle relazioni che viene disfunzionalmente compensata attraverso la condotta abusante. L’analisi dei due casi viene specificata con la descrizione degli obiettivi trasformativi dell’intervento psicosociale destinato ai minori abusanti.Interpersonal relationships allow children to learn how to recognise emotional experiences, as well as how to use socially acceptable manners. Among different variables explaining the conduct of young offenders, the lack of emotional competence and an insecure attachment bond are particularly relevant. The assessment of personal history and the Adult Attachment Interview of two users of the Minors Social Service Office (USSM) of Palermo, accused of a sexual offense, has highlighted a lack of intimacy in relationships, compensated in a dysfunctional way by an abusive conduct. The analysis of these two cases is supported by including the description of transformative objectives of the psychosocial intervention oriented to young offenders
Optical properties of PbS quantum dot doped sol-gel films
No full textPbS nanoparticles have been prepared via a colloidal route and were incorporated in hybrid organic-inorganic sol–gel films.
X-ray diffraction and transmission electron microscopy showed the presence of spherically shaped particles with nanometric diameter.
The absorption spectra showed a large blue shift of the absorption edge to shorter wavelength, indicating strong quantum confinement.
Strong photoluminescence emission in the near infrared was found by pumping at 514 nm. The femtosecond pump–probe
technique was used for studying the relaxation dynamics of the PbS-doped films by pumping at 80 0nm and probing at 1500 nm
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