8,330 research outputs found

    The determinants and employment effects of international outsourcing: the case of Italy

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    Using a new firm-level database, we address micro determinants and employment consequences of international production outsourcing (INPOU). Regarding the former, we confirm that INPOU in Italy mostly counters emerging economies. threats to traditional manufactured goods: INPOU disproportionately targets developing countries and intensifies in sectors with stiffest Chinese competition. Concerning employment consequences, we concur with previous literature that INPOU firms. domestic employment performances are no worse than at matching no-INPOU firms. However, given Italy.s industrial structure (small-sized networked enterprises), INPOU might negatively affect subcontracting firms. Our evidence that employment performances worsen in the productive segments with strongest INPOU supports our conjecture.international outsourcing, multinational firms

    Numerical simulation of lava flows based on depth-averaged equations

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    Risks and damages associated with lava flows propagation (for instance the most recent Etna eruptions) require a quantitative description of this phenomenon and a reliable forecasting of lava flow paths. Due to the high complexity of these processes, numerical solution of the complete conservation equations for real lava flows is often practically impossible. To overcome the computational difficulties, simplified models are usually adopted, including 1-D models and cellular automata. In this work we propose a simplified 2D model based on the conservation equations for lava thickness and depth-averaged velocities and temperature which result in first order partial differential equations. The proposed approach represents a good compromise between the full 3-D description and the need to decrease the computational time. The method was satisfactorily applied to reproduce some analytical solutions and to simulate a real lava flow event occurred during the 1991-93 Etna eruption.Comment: 4 pages, 4 figure

    Nonlinear phenomena in fluids with temperature-dependent viscosity: an hysteresis model for magma flow in conduits

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    Magma viscosity is strongly temperature-dependent. When hot magma flows in a conduit, heat is lost through the walls and the temperature decreases along the flow causing a viscosity increase. For particular values of the controlling parameters the steady-flow regime in a conduit shows two stable solutions belonging either to the slow or to the fast branch. As a consequence, this system may show an hysteresis effect, and the transition between the two branches can occur quickly when certain critical points are reached. In this paper we describe a model to study the relation between the pressure at the inlet and the volumetric magma flow rate in a conduit. We apply this model to explain an hysteric jump observed during the dome growth at Soufri\`ere Hills volcano (Montserrat), and described by Melnik and Sparks [1999] using a different model.Comment: 4 pages, 4 figures, corrected version of "Nonlinear phenomena in fluids with temperature-dependent viscosity: an hysteresis model for magma flow in conduits" GRL Vol 29, No 10,200

    Photometry of the five marginally studied open clusters Collinder 74, Berkeley 27, Haffner 8, NGC 2509 and VdB-Hagen 4

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    The stellar populations in the outer Galactic disk are nowadays a subject of wide interest. To contribute to a better picture of this part of the Galaxy, we have studied the nature of five marginally investigated star clusters (Collinder 74, Berkeley 27, Haffner 8, NGC 2509, and VdB-Hagen 4) by means of accurate CCD photometry in the V and I pass-bands. These clusters are in fact located in the Third Galactic Quadrant. We aim to obtain the basic parameters of these objects, which in some cases are still disputed in the literature. In the case of VdB-Hagen 4 we provide the first estimate of its fundamental parameters, while for Haffner 8 we present the first CCD photometry. The analysis is based on the comparison between field stars decontaminated Color Magnitude Diagrams and stellar models. Particular care is devoted to the assessment of the data quality, and the statistical field stars decontamination. The library of stellar isochrones from Girardi et al. (2000) is adopted in this study. The analysis we carried out allowed us to solve a few inconsistencies in the literature regarding Haffner 8 and NGC 2509. Collinder 74 is found to be significantly older than reported before. VdB-Hagen 4 is a young open cluster located more than 20 kpc from the Galactic center. Such an extreme distance is compatible with the cluster belonging to the Norma-Cygnusarm.Comment: 10 pages, 17 eps figures (some of them degraded in resolution), in press in Astronomy and Astrophysic

    Firing at Subcontractors? Spillover Employment Effects of Offshoring in Italy

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    Using firm-level data for Italy, we address the employment consequences of international production offshoring. We concur with previous literature that offshoring firms’ individual employment performances are no worse than at matching non-offshoring firms. However, offshoring might impart negative spillover effects on subcontracting firms, and this indirect effect might be felt particularly in Italy’s industrial structure (small-sized networked enterprises). To study this, we group firms within their typical subcontracting clusters, identify high offshoring clusters and compare them with a matching low offshoring sample. The evidence that employment performances worsen in the productive clusters with high offshoring supports our conjecture.International outsourcing, multinational firms, employment effects, propensity

    New wine in new bottles: Visualizing the progression over time of the epidemics of tobacco smoking and obesity through the use of modified population pyramids

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    Tobacco smoking and obesity greatly contribute to premature death and disease in developed countries. In order to measure the extent to which these risk factors affect a population, as well as to describe the progression of these epidemics over time, routine surveillance of the prevalence of obesity and smoking is carried out by international organizations, national departments of health, and statistical offices. To this end, summary measures—like age-standardized rates, and tabular and graphical representations, such as maps—are used. In this study, we argue that population pyramids, a widely used demographic tool, may be easily adapted to provide relevant visual information for public health purposes. By means of two juxtaposed histograms, one for each gender, population pyramids show either the proportion or the actual number of subjects in each age and gender subgroup. We suggest that stratifying each bar of the two histograms according to ordinal categories of the health condition or risk factor examined may provide useful details on the relationship between this condition or factor and key demographic variables like age and gender. In addition, the actual number of exposed subjects can be immediately read from the graph. We therefore built a statistical routine with Stata to create modified population-pyramid plots separately for overweight/obese and current/former smoker. Data were derived from five National Health Interview Surveys carried out in Italy between 1983 and 2005. For each survey, data on age, gender, smoking status, height, and weight were extracted for subjects aged 20–99. Age and gender-specific prevalence rates of overweight/obese, and of current/former/never smoker were computed and applied to population estimates performed by the Italian national statistical institute (ISTAT). The resulting estimated numbers of underweight/normal weight/overweight/obese individuals and of former/current/never smokers were used to create the modified population pyramids. In conclusion, modified population pyramids may contribute to assessing the impact of risk factors on a population in absolute terms, to evaluating how these risk factors are distributed by age and gender, and to assessing how the age and gender distribution of these risk factors changes over time.
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