Analytical model of 1D Carbon-based Schottky-Barrier Transistors

Nanotransistors typically operate in far-from-equilibrium (FFE) conditions, that cannot be described neither by drift-diffusion, nor by purely ballistic models. In carbonbased nanotransistors, source and drain contacts are often characterized by the formation of Schottky Barriers (SBs), with strong influence on transport. Here we present a model for onedimensional field-effect transistors (FETs), taking into account on equal footing both SB contacts and FFE transport regime. Intermediate transport is introduced within the Buttiker probe approach to dissipative transport, in which a non-ballistic transistor is seen as a suitable series of individually ballistic channels. Our model permits the study of the interplay of SBs and ambipolar FFE transport, and in particular of the transition between SB-limited and dissipation-limited transport

Metabolic properties of the products of mitochondrial protein synthesis in HeLa cells

The metabolic behavior of the mitochondrial protein synthesis products has been investigated in HeLa cells. Particular attention was given to the four major electrophoretic components (designated as Nos. 2, 3, 5, and 8) of the 10 previously identified as organelle-specific products. Inhibition of cytoplasmic protein synthesis with emetine or cycloheximide causes a rapid decline in the rate of mitochondrial protein synthesis, with an estimated half-life of 1 to 2 h, affecting in a parallel way all the discrete components. About 30% of the original synthetic activity appears to be resistant to emetine treatment for at least 24 h; however, all the polypeptides synthesized after the first 4 h of cell exposure to emetine are metabolically unstable, possibly because of lack of integration into the inner mitochondrial membrane. An analysis of the stability of newly synthesized products of mitochondrial protein synthesis pulse-labeled in the presence of cycloheximide and then chased in the absence of the drug (i.e. under conditions of resumed cytoplasmic protein synthesis) has revealed marked differences among the various discrete components. In particular, about three-fourths of the radioactivity associated with components 3 and 5 decays within 4 h of chase, the remainder being substantailly stable afterwards; by contrast, the radioactivity in components 2 and 8 shows only a slow decline during a 3-day chase. If the chase is carried out under conditions of a persistent block of cytoplasmic protein synthesis, as is the situation after a pulse labeling in the presence of emetine, all newly synthesized components appear to be destablized in various degrees, with the exception of component 5, which is to a great extent stabilized. Inhibition of mitochondrial protein synthesis with chloramphenicol has a progressive stabilizing effect on most of the discrete components newly synthesized after removal of the drug; this effect is especially striking in the case of component 5 which, in experiments of continuous labeling in the presence of emetine after prolonged chloramphenicol treatment, becomes, after 24 h of labeling or more, the only recognizable peak in the electrophoretic pattern of the sodium dodecyl sulfate-lysed mitochondrial fraction. The results of the kinetic experiments described here are interpreted in terms of two roles of cytoplasmically synthesized proteins, one required for the synthesis of polypeptides within the organelles, the other necessary for the stabilization of the mitochondrial products

Prioritization methodology for roadside and guardrail improvement: Quantitative calculation of safety level and optimization of resources allocation

The attention to road safety-related issues has grown fast in recent decades. The experience gained with these themes reveals the importance of considering these aspects in the resource allocation process for roadside and guardrail improvement, which is a complex process often involves conflicting objectives. This work consists on defining an innovative methodology, with the objective of calculating and analysing a numerical risk factor of a road. The method considers geometry, accident rate, traffic of the examined road and four categories of elements/defects where the resources can be allocated to improve the road safety (safety barriers, discrete obstacles, continuous obstacles, and water drainage). The analysis allows the assessment of the hazard index, which could be used in decision-making processes. A case study is presented to analyse roadsides of a 995 km long road network, using the cost-benefit analysis, and to prioritize possible rehabilitation work. The results highlighted that it is suitable to intervene on roads belonging to higher classes of risk, where it is possible to maximize the benefit in terms of safety as consequence of rehabilitation works (i.e., new barrier installation, removal and new barrier installation, and new terminal installation). The proposed method is quantitative; therefore, it avoids providing weak and far from reliable results; moreover, it guarantees a broad vision for the problem, giving a useful tool for road management body

Ground states in complex bodies

A unified framework for analyzing the existence of ground states in wide classes of elastic complex bodies is presented here. The approach makes use of classical semicontinuity results, Sobolev mappinngs and Cartesian currents. Weak diffeomorphisms are used to represent macroscopic deformations. Sobolev maps and Cartesian currents describe the inner substructure of the material elements. Balance equations for irregular minimizers are derived. A contribution to the debate about the role of the balance of configurational actions follows. After describing a list of possible applications of the general results collected here, a concrete discussion of the existence of ground states in thermodynamically stable quasicrystals is presented at the end.Comment: 30 pages, in print on ESAIM-COC

The Evolution of Confidence for European Consumers and Businesses in France, Germany and Italy

The paper examines the evolution of consumer and business confidence indexes in France, Germany and Italy since the mid-eighties, using regressions of the indexes on a set of common macroeconomic variables for each country. Comparison of the results across agents (i.e. consumers and entrepreneurs in the same country) and across countries highlights some differences in behaviour that have emerged in the last fifteen years. In particular, the paper inquires into the causes of the recent break in the relationship between the consumer and business confidence indexes.firms and consumers confidence index

A Comparative Perspective on Italy’s Human Capital Accumulation

This paper reviews the evolution of educational institutions and outcomes over the 150 years since Italy’s unification, and discusses their interaction with national and regional growth patterns. While initial educational conditions contributed to differentiate across regions the early industrial take off in the late 19th century, and formal education does not appear to have played a major role in the postwar economic boom, the slowdown of Italy’s economy since the 1990s may be partly due to interactions between its traditionally low human capital intensity and new comparative advantage patterns, and to the deterioration since the 1970s of the educational system’s organization.Education systems, tracking, economic growth, regional convergence

A Global Network and its Local Ties. Restructuring of the Benetton Group

The paper investigates the change in strategy of the Benetton Group, since the mid nineties, in face of the severe intensive competition in the international fashion market. New competitors, in particular the European brands Zara, Mango and H&M, have challenged the Benetton position in the Italian and the European clothing market and have pushed the Group towards cost reduction through globalization of his suppliers. Benetton is a vertically integrated producer that controls (in different ways) the whole value chain from textile raw materials to the sales to the consumers. Till 2000 Benetton made part of its production in its own factories and through a wide network of domestic sub-contractors, mainly specialized in sewing. Now Benetton has drastically moved to a new strategy, abandoning Italy and organizing production around a dual supply chain: close locations (East Europe and North Africa) for quick production and far away locations (Asia) for more standardised products. The paper discusses also the redefinition of competences for the Treviso clothing district, where Benetton traditional sub-contractors have been in few years, drastically curtailed. Benetton restructuring marks the transition to a new network of competences between agents in the district.Global value chains, Internationalization, Benetton, Apparel

Connections and Competences in the Governance of the Value Chain. How Industrial Countries Maintain their Competitive Advantage.

The aim of our paper is to analyse the governance of value chains operating in the traditional sectors of clothing and footwear, focusing particularly on production de-localization from the Italian region of Veneto to the nearby country of Rumania After describing and ‘quantifying’ the internationalization process between Veneto and Rumania we turn to discuss the possible consequences of this process, both for the region of origin and the recipient area. We highlight, through the concepts of linkages and competences how the production internationalization process may determine a progressive weakening of the network of linkages that characterize the home region, and discuss the main obstacles to a successful transfer of know-how and technologies to the host system. From this discussion emerges the vision of some policy measures to amplify possible positive effects and counter negative consequences of the fragmentation of production, both in the home and in the host country.Internationalisation, Industrial districts, Delocalisation, Organization of Production