51 research outputs found

    The Semitransparent Photovoltaic Films for Mediterranean Greenhouse: A New Sustainable Technology

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    Mediterranean countries offer very favorable climatic conditions for growing plants in a protected environment: as a matter of fact, the high solar radiation allows the use of greenhouses with simple structures, covered with plastic film and without fixed installations for winter heating. They are called "Mediterranean greenhouses" and are totally different from those in Central and Northern Europe. In the photovoltaic greenhouses, the cover on the pitch facing south is usually replaced by very opaque panels. However, this solution compromises the possibility to grow plants in covered and protected environments since solar radiation availability is limited and strongly nonuniform. In order to overcome this problem, semitransparent photovoltaic materials can be used to let the solar energy, necessary for plant growth, pass into the green house. The aim of this research is to analyze the radiometric properties of innovative semitransparent flexible photovoltaic materials in order to evaluate their performances in comparison with materials commonly used in the coverage of the greenhouses. Particular attention is paid to the transmittance of these materials in the visible range and in the long wave infrared for the achievement of greenhouse effect

    Photovoltaic Pumps: Technical and Practical Aspects for Applications in Agriculture

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    The paper deals with a series of tests conducted on a PV-DC pump in Viterbo (42°24′ North, 12°06′ East). The tests lasted from January 2003 up to November 2004 and involved measurements of solar radiation, on both a horizontal surface and the tilted module surface, flow rates, volumes, and total dynamic heads. In total, up to 3000 data were collected every day whose analysis allowed us to find empirical relationships among system efficiencies, solar radiations, and total dynamic heads. In the second part of the paper we develop a simple method that allows both the assessment of performances of the whole system when installed in a different site from that in which the tests were performed and the optimal inclination angle of the panel to be determined in relation to annual or seasonal use (see irrigation)

    L’immigrazione nella trasformazione dei contesti urbani: il caso siciliano, l’esigenza del recupero culturale ed il rifiuto della marginalizzazione

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    The issue of the immigration leads to reorganize the whole social architecture of the societies in which it occurs. Considering the urban environment as a microcosm which has a great deal of influence on global dynamics, it is right to think about the living conditions of urban citizens who live in the multicultural present societies, often suffering marginalization. As the last researches claim, the local government system is the one that could help to deal with the immigration matter in the best way and this also needs to be urgently addressed, as the “Immigration in Sicily” case study could show

    Serum Resistin, Cardiovascular Disease and All-Cause Mortality in Patients with Type 2 Diabetes

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    Background: High serum resistin has been associated with increased risk of cardiovascular disease in the general population, Only sparse and conflicting results, limited to Asian individuals, have been reported, so far, in type 2 diabetes. We studied the role of serum resistin on coronary artery disease, major cardiovascular events and all-cause mortality in type 2 diabetes. Methods: We tested the association of circulating resistin concentrations with coronary artery disease, major cardiovascular events (cardiovascular death, non-fatal myocardial infarction and non-fatal stroke) and all-cause mortality in 2,313 diabetic patients of European ancestry from two cross-sectional and two prospective studies. In addition, the expression of resistin gene (RETN) was measured in blood cells of 68 diabetic patients and correlated with their serum resistin levels. Results: In a model comprising age, sex, smoking habits, BMI, HbA1c, and insulin, antihypertensive and antidyslipidemic therapies, serum resistin was associated with coronary artery disease in both cross-sectional studies: OR (95%CI) per SD increment = 1.35 (1.10–1.64) and 1.99 (1.55–2.55). Additionally, serum resistin predicted incident major cardiovascular events (HR per SD increment = 1.31; 1.10–1.56) and all-cause mortality (HR per SD increment = 1.16; 1.06–1.26). Adjusting also for fibrinogen levels affected the association with coronary artery disease and incident cardiovascular events, but not that with all cause-mortality. Finally, serum resistin was positively correlated with RETN mRNA expression (rho = 0.343). Conclusions: This is the first study showing that high serum resistin (a likely consequence, at least partly, of increased RETN expression) is a risk factor for cardiovascular disease and all-cause mortality in diabetic patients of European ancestry

    In-work poverty, precarious work and indebtedness. The steady state European equilibrium?

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    Since the establishment of a European strategy to create more and better jobs at the end of ’90s Member States faced many efforts pursuing the target of high percentage of employed persons, target renewed with Europe 2020 strategy. In the same years many citizenship rights, universally recognized, started to be conditioned to the employment status: the “welfarism” was rapidly substituted with “workfare”, with the twin aims of encouraging activation of labour force and - less claimed – of cutting public expenses, especially in social services. In this paper we analyse trends and relations of certain dimension of employment to better understand the sustainability of this approach. The “new” employment is more and more characterized by undermining factors: insecurity, precariousness, poverty. States pursuing active labour market policies, under a Flexicurity approach, besides a good labour market performance, are still facing with poverty and job insecurity of many workers. This is accompanied by growth of household indebtedness, the other dangerous drawback of welfare “commodification” processes. Beyond enforce Employment Protection Legislations, Basic income or Minimum wages, we should change the targets of European strategy with more social or qualitative components (e.g. quality of employment) and get over the Flexicurity approac

    Comparison between Demand and Supply of Some Ecosystem Services in National Parks: A Spatial Analysis Conducted Using Italian Case Studies

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    In recent decades, modeling approaches of ecosystem services (ES) have been used extensively at the international level, providing useful tools during the decision-making process by integrating both physical and economic information, thus improving its management. The relationship between supply and demand may impact social welfare: for example, a deficit in ES could negatively influence demand (either potential or effective). For this reason, the relational study between supply and demand is necessary for the sustainable management of natural resources; particularly since the demand for some ES must be fulfilled not only on a local scale but also globally (as in the case of regulatory ES). This paper proposes an ES analysis framework that links the flow of services (supply) generated by the interaction between natural, human and social capital with consumption (demand) connected to potential beneficiaries. Specifically, we analyze three ES: Forage production, regulation of local climate (PM10), and carbon sequestration in three national parks (Aspromonte National Park, Circeo National Park, and Appennino Tosco Emiliano National Park). The use of synthetic (biophysical) indicators, on a spatial basis, made it possible to quantify the supply and demand of specific catchments with the aim of accounting for the surplus/deficit through the calculation of the ES supply and demand ratio (ESDR). In fact, sustainable land management requires a balance between supply and demand in relation to the different needs of the stakeholders and local community. The relationship between supply and demand of ES can help identify resource use trade-offs, thus rendering the achievement of management and protection objectives more efficient. Lastly, through the use of monetary coefficients, it was possible to calculate the benefits of increasing the awareness of public decision-makers of ES’s value and the importance of implementing integrated strategies for environmental protection and enhancement
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