304 research outputs found
Varieties of organic products from dairy sheep and goats production systems in the Mediterranean region.
Challenging Climate Strikers' Youthfulness: The Evolution of the Generational Gap in Environmental Attitudes Since 1999
In 2019, youth took to the street to express their fears and ambitions in relation to climate change. Alongside, many adult and senior citizens expressed their solidarity. While the media present environmental issues as being generationally dividing, we know little about potential differences between generations in terms of environmental attitudes. In this paper, we analyze data collected in the framework of street demonstrations in Switzerland and longitudinal data collected in the Swiss population. Our analyses of survey data on climate strike demonstrators in Switzerland show that while the early demonstrations attracted mostly youth, the age composition of climate strike demonstrators became more diverse over time increasingly including members of different generations. Furthermore, we explore how age differences evolved over the last 20 years using the Swiss Household Panel data. Our analyses show that the share of individuals who favor the environment over the economy is greater among younger generations and that the climate strike generation stands out with the largest share of pro-environmental attitudes. However, all generations have moved in parallel over the last twenty years following a non-linear but generally upward trend illustrating that the political context affects all generations. Overall, our analyses contribute to understanding incremental changes in public attitudes in the environmental area and the role played by generational renewal in these regards
Metrological characterization of a vision-based system for relative pose measurements with fiducial marker mapping for spacecrafts
An improved approach for the measurement of the relative pose between a target and a chaser spacecraft is presented. The selected method is based on a single camera, which can be mounted on the chaser, and a plurality of fiducial markers, which can be mounted on the external surface of the target. The measurement procedure comprises of a closed-form solution of the Perspective from n Points (PnP) problem, a RANdom SAmple Consensus (RANSAC) procedure, a non-linear local optimization and a global Bundle Adjustment refinement of the marker map and relative poses. A metrological characterization of the measurement system is performed using an experimental set-up that can impose rotations combined with a linear translation and can measure them. The rotation and position measurement errors are calculated with reference instrumentations and their uncertainties are evaluated by the Monte Carlo method. The experimental laboratory tests highlight the significant improvements provided by the Bundle Adjustment refinement. Moreover, a set of possible influencing physical parameters are defined and their correlations with the rotation and position errors and uncertainties are analyzed. Using both numerical quantitative correlation coefficients and qualitative graphical representations, the most significant parameters for the final measurement errors and uncertainties are determined. The obtained results give clear indications and advice for the design of future measurement systems and for the selection of the marker positioning on a satellite surface
Herd structure in the bovine Calvana breed
Farm structure is one of the principle components that influence profit, sustainability and survival of a herd, especially in endangered breeds. The sustainability of these herds is based on the capability to take advantage of specific niches of the market, of specific label or organic certification or "designation of geographical indications or origin for agricultural products"
A Study on Contestable Regions in Europe through the Use of a New Rail Cost Function: An Application to the Hinterland of the New Container Terminal of Leghorn Port
In this paper, the potential hinterland of the new container terminal of the port of Leghorn (Livorno in Italian) is studied. The study actually analyses the competitiveness of major European ports with respect to some of the most contestable regions in Europe. Travel time and monetary costs of railway paths, connecting ports to their hinterland, have been determined. The rail network of a large part of Europe was modelled using a graph. To each link, which represents a portion of the rail line, a cost function is associated. The travel time on the link is determined from the average speed, which has been determined from the maximum speed via formulae obtained through linear regression. The few cost functions that exist in current literature for the computation of the cost of a rail link are not detailed enough. Therefore, a new cost function has been developed. All cost components were determined in detail: the staff cost, the amortisation, maintenance, and insurance costs of locomotives and wagons, the cost of the usage of rail track, the traction cost. The traction cost was calculated in detail from all resistances to motion. Moreover, for each rail link, the number of locomotives needed to operate the train and the maximum towable weight were determined. The monetary value of time in freight transport registers a high variability; therefore, three different optimisations of the pathsâby travel times, monetary costs, and generalised costsâbetween each originâdestination pair were carried out. The rates of competitiveness of the ports with respect to the examined European contestable regions were analysed
Animal production and marketing for the diffusion of organic farming in the natural parks of Tuscany in Italy
Productive performances of Maremmana young bulls reared following organic rules and slaughtered at 18 and 24 months of age
Fourteen Maremmana young bulls fed on pastures supplemented with mixed hay and concentrates, according to an organic method, were slaughtered at 18 and 24 months of age to evaluate in vita and post-mortem performances. At slaughter, carcass yield was determined and carcass evaluation according to EU rules wasmade. Physico-chemical characteristics of Longissimus thoracis (LT) and Caput longum triceps brachii (TB) muscles were determined. No differences for both carcass yield and quality were found between the two age groups. Animals of 24 months of age presented lighter and more yellow meat as well as higher hue angle and drip loss. TB muscle showed lower protein content and higher shear force, moisture, total lipids and ash than LT. The latter presented a higher percentage of C15iso, whereas TB showed higher values of C18:2n6, C20:3n6, C20:4n6, C18:3n3 and C22:5n3. Maremmana animals, irrespective of age, showed a low percentage of saturated fatty acids, good PUFA/SFA ratio and a great amount of unsaturated fatty acids of the n3 and n6 series, as well as a favorable atherogenicity and thrombogenicity indexes
Space tethers: parameters reconstructions and tests
In the last several years, the need for an alternative to chemical propulsive systems for low-orbit satellite deorbiting has become increasingly evident; a Tethered System can provide adequate thrust or drag without the complications of combustions and with a minimal impact on the environment. In this context, the authors are part of a team that is studying various tether applications and building a prototype of an electrodynamic tether system. The goal of this paper is to characterize tether materials in order to find valid solutions for future space tether missions. Mission requirements (e.g., the survivability to hypervelocity impacts and the capability to damp oscillations in electrodynamic tethers) influence the choice of tether parameters such as cross section geometry (round wires or tapes), materials, length, and cross section sizes. The determination of the elastic characteristics and damping coefficients is carried out through a campaign of experiments conducted with both direct stress/strain measurements and the laboratory facility SPAcecRraft Testbed for Autonomous proximity operatioNs experimentS (SPARTANS) on a low friction table at the University of Padova. In the latter case, the stiffness and damping of a flexible line were verified by applying different tensile load profiles and then measuring the tether-line dynamic response in terms of tension spike amplitude, oscillation decay, and estimation of the damping coefficient
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