1,524 research outputs found
Electric Waterborne Public Transportation in Venice: a Case Study
The paper reports the results of a study for moving the present diesel-based watercraft propulsion technology used for public transportation in Venice city and lagoon to a more efficient and smart electric propulsion technology, in view of its adopted in a near future. Energy generation and storage systems, electrical machines and drives, as well as economic, environmental and social issues are presented and discussed. Some alternative solutions based on hybrid diesel engine and electric and full electric powertrains are compared in terms of weights, costs and payback times. Previews researches on ship propulsion and electric energy storage developed by the University of Padua and preliminary experiences on electric boats carried out in Venice lagoon by the municipal transportation company ACTV and other stakeholders are the starting point for this study. Results can be transferred to other waterborne mobility systems
A study of the hydrographic conditions in the Adriatic Sea from numerical modelling and direct observations (2000–2008)
The inter-annual variability of Adriatic Sea hydrographic
characteristics is investigated by means of numerical
simulation and direct observation. The period under investigation
runs from the beginning of 2000 to the end of 2008.
The model used to carry out the simulation is derived from
the primitive equation component of the Adriatic Forecasting
System (AFS). The model is based on the Princeton Ocean
Model (POM) adapted in order to reproduce the features
of the Adriatic. Both numerical findings and observations
agree in depicting a strong inter-annual variability in the entire
Adriatic Sea and its sub-basins. Nevertheless, two model
deficiencies are identified: an excessive vertical/horizontal
mixing and an inaccurate representation of the thermohaline
properties of the entering Mediterranean Waters. The dense
water formation process has been found to be intermittent.
In addition to inter-annual variability, a long-scale signal has
been observed in the salinity content of the basin as a consequence
of a prolonged period of reduced Po river runoff
and high evaporation rates. As a result, the temperature and
salinity of the northern Adriatic dense water vary considerably
between the beginning and the end of the period investigated
A Framework to Assess Social Indicators in a Circular Economy Perspective
The thriving circular economy is expected to contribute to all three dimensions of sustainable development: environmental, economic, and social. This paper aims to propose a framework to assess social indicators to support circular business models. To validate the framework, we conducted a case study in a medium-size Italian footwear luxury industry, using the Value Focused Thinking-VFT. This approach was used to define proper social indicators to measure the perception of the company's managers related to the level of incorporation of social dilemmas in the company. We collect data through interviews, documental analysis and direct observation from October/2019 until August/2020 and apply a questionnaire in 2020/2021. The novelty of this paper lies in the proposition of a framework to assess the social indicators in broad categories, capable of covering all supply chains: Corporation, Community; Consumers; Suppliers; Human Rights and Human Resources. Another novelty is related to the analysis of indicators in terms of strategic, tactical, and operational levels, similarly to the idea of a Balanced Scorecard, which was allowed by applying the VFT approach
sensitivity of the mediterranean sea level to atmospheric pressure and free surface elevation numerical formulation in nemo
Abstract. The sensitivity of the dynamics of the Mediterranean Sea to atmospheric pressure and free surface elevation formulation using NEMO (Nucleus for European Modelling of the Ocean) was evaluated. Four different experiments were carried out in the Mediterranean Sea using filtered or explicit free surface numerical schemes and accounting for the effect of atmospheric pressure in addition to wind and buoyancy fluxes. Model results were evaluated by coherency and power spectrum analysis with tide gauge data. We found that atmospheric pressure plays an important role for periods shorter than 100 days. The free surface formulation is important to obtain the correct ocean response for periods shorter than 30 days. At frequencies higher than 15 days−1 the Mediterranean basin's response to atmospheric pressure was not coherent and the performance of the model strongly depended on the specific area considered. A large-amplitude seasonal oscillation observed in the experiments using a filtered free surface was not evident in the corresponding explicit free surface formulation case, which was due to a phase shift between mass fluxes in the Gibraltar Strait and at the surface. The configuration with time splitting and atmospheric pressure always performed best; the differences were enhanced at very high frequencies
Learning activation functions from data using cubic spline interpolation
Neural networks require a careful design in order to perform properly on a
given task. In particular, selecting a good activation function (possibly in a
data-dependent fashion) is a crucial step, which remains an open problem in the
research community. Despite a large amount of investigations, most current
implementations simply select one fixed function from a small set of
candidates, which is not adapted during training, and is shared among all
neurons throughout the different layers. However, neither two of these
assumptions can be supposed optimal in practice. In this paper, we present a
principled way to have data-dependent adaptation of the activation functions,
which is performed independently for each neuron. This is achieved by
leveraging over past and present advances on cubic spline interpolation,
allowing for local adaptation of the functions around their regions of use. The
resulting algorithm is relatively cheap to implement, and overfitting is
counterbalanced by the inclusion of a novel damping criterion, which penalizes
unwanted oscillations from a predefined shape. Experimental results validate
the proposal over two well-known benchmarks.Comment: Submitted to the 27th Italian Workshop on Neural Networks (WIRN 2017
COMPARING DATA ACQUISITION METHODOLOGIES FOR DTM PRODUCTION
In this paper we present the results related to several field campaigns conducted in the last three years in a small (4.4 km2) wilderness basin in Carnia, a tectonically active alpine region in northeast Italy. The study area is a typical alpine debris-flow dominated catchment where several landslides, including a significantly large one, were observed and mapped. The field survey carried out in 2007, 2008, 2009 and 2010 were focused on the large landslide of the basins and they consisted in the following steps: 1 – development of an accurate GPS network, 2 – make use of a long range Terrestrial Laser Scanner (TLS) for a detailed and local analysis of landslide movements, 3 – merge the data with an airborne LiDAR for a large scale analysis of the processes. Preliminary analysis consist in the comparison of different high resolution Digital Terrain Models (DTMs) in order to estimate the debris volume that has been triggered during the last movements of the landslides. Achieved results show that the integration between ALS and TSL data allows to produce DTMs of limited extent, with higher quality and level of detail. Such DTMs improve the capabilities for landslides analysis and modelling with respect to the use of LiDAR data only, even in areas providing limited or difficult access for the survey activity
Physical-Mechanical Modifications of Eggs for Food-Processing During Storage
Abstract Physical-mechanical properties of egg constituents and their modifications during storage and poststorage greatly influence the efficiency of food processing, such as the separation of white and yolk by mechanical shelling. Thick albumen height, Haugh unit, yolk index and vitelline membrane-yolk system strength of eggs from Hy-Line White and Lohmann Brown hens were analyzed during 7 mo of storage at 0°C performing 3 poststorage treatments: i) immediately after refrigeration, T1; ii) after a further 6 h at 18°C after refrigeration, T2; and iii) after a week at 18°C after refrigeration, T3. For all qualitative parameters considered, this last poststorage treatment appeared to be the factor that produced the highest decrements; with respect to the first poststorage treatment, a further week at 18°C after refrigeration can involve mean decreases of about 19, 14, 14, and 16% in thick albumen height, Haugh unit, yolk index, and vitelline membrane-yolk system strength (in terms of maximum force), respectively. During about 7 mo of storage at 0°C, the latter parameter decreases, on average, by 10%. Increasing the storage time, physical-mechanical behavior was sometimes divergent from the observed trends
A validated dynamical model of a kW-class Vanadium Redox Flow Battery
The development of redox flow batteries depends on the research on new materials as well as on the technological development, but also on appropriate models which allow to simulate their performance in operative conditions. Very few investigations are reported in the literature concerning the technology, modeling and simulation of large-scale Vanadium Redox Flow Battery systems, built around multi-cell stacks. This paper regards the modeling of an industrial-sized 9 kW test facility. In particular, a complete dynamic model is presented, that takes into account all thermal effects occurring inside the stack, resulting in a complex non-linear coupled formulation, that allows to simulate the battery operation in any realistic conditions. The model is able to simulate the thermal behavior both in standby, i.e. without power and reactant flow, as well as in load operation, i.e. in charge and discharge. The numerical implementation of the model is described in detail. The model validation is also described, consisting in comparing computed data with experimental measurements taken on the available test facility
A new dataset and empirical relationships between magnitude/intensity and epicentral distance for liquefaction in central-eastern Sicily
Strong earthquakes can trigger several phenomena inducing soil deformation, such as liquefaction, ground fracturing
and landslides, which can often cause more damage than the seismic shaking itself. A research performed
on numerous historical accounts reporting descriptions of seismogeological effects in central-eastern Sicily, allowed
the authors to update the previous liquefaction datasets. 75 liquefaction-induced phenomena observed in
26 sites, triggered by 14 earthquakes, have been used to define relationships between intensity/magnitude values
and epicentral distance from the liquefied sites. The proposed upper bound-curves, at regional scale for central-
eastern Sicily, are realized by using the updating liquefaction dataset and also the new CPTI04 Italian earthquake
parametric catalogue. These relationships can be useful in hazard assessment to evaluate the minimum energy
of an earthquake inducing liquefactions
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