Floating structures in shallow water: local well-posedness in the axisymmetric case

The floating structure problem describes the interaction between surface water waves and a floating body, generally a boat or a wave energy converter. As shown by Lannes in [18] the equations for the fluid motion can be reduced to a set of two evolution equations on the surface elevation and the horizontal discharge. The presence of the object is accounted for by a constraint on the discharge under the object; the pressure exerted by the fluid on this object is then the Lagrange multiplier associated to this constraint. Our goal in this paper is to prove the well-posedness of this fluid-structure interaction problem in the shallow water approximation under the assumption that the flow is axisymmetric without swirl. We write the fluid equations as a quasilinear hyperbolic mixed initial boundary value problem and the solid equation as a second order ODE coupled to the fluid equations. Finally we prove the local in time well-posedness for this coupled problem, provided some compatibility conditions on the initial data are satisfied

Emergent processes as generation of discontinuities

In this article we analyse the problem of emergence in its diachronic dimension. In other words, we intend to deal with the generation of novelties in natural processes. Our approach aims at integrating some insights coming from Whitehead’s Philosophy of the Process with the epistemological framework developed by the “autopoietic” tradition. Our thesis is that the emergence of new entities and rules of interaction (new “fields of relatedness”) requires the development of discontinuous models of change. From this standpoint natural evolution can be conceived as a succession of emergences — each one realizing a novel “extended” present, described by distinct models — rather than as a single and continuous dynamics. This theoretical and epistemological framework is particularly suitable to the investigation of the origin of life, an emblematic example of this kind of processes

Embedding Session Types in HML

Recent work on the enhancement of multiparty session types with logical annotations enable the effective verification of properties on (1) the structure of the conversations, (2) the sorts of the messages, and (3) the actual values exchanged. In [3] we extend this work to enable the specification and verification of mutual effects of multiple cross-session interactions. Here we give a sound and complete embedding into the Hennessy-Milner logic to justify the expressiveness of the approach in [3] and to provide it with a logical background that will enable us to compare it with similar approaches

The school meal system: analysis of calls for tender as a tool for improving quality

The quality of school meals is a very complex issue. Call for tenders are a key instrument impacting food and meal quality

Timed Runtime Monitoring for Multiparty Conversations

We propose a dynamic verification framework for protocols in real-time distributed systems. The framework is based on Scribble, a tool-chain for design and verification of choreographies based on multiparty session types, developed with our industrial partners. Drawing from recent work on multiparty session types for real-time interactions, we extend Scribble with clocks, resets, and clock predicates constraining the times in which interactions should occur. We present a timed API for Python to program distributed implementations of Scribble specifications. A dynamic verification framework ensures the safe execution of applications written with our timed API: we have implemented dedicated runtime monitors that check that each interaction occurs at a correct timing with respect to the corresponding Scribble specification. The performance of our implementation and its practicability are analysed via benchmarking

The footprint of organic farms. Some ecological indicators to evaluate it Department of Food crops – State University of Milan

Agro-ecological indicators are a tool which provides an agile evaluation of the ecological footprint of a farm. This paper analyses the preliminary results of a survey in which 7 agro-ecological indicators were calculated for 81 organic farms in the region of Lombardy in the northern part of Italy. The indicators chosen (all indicators of State) are: hedges and rows, energy input, energy output, energy output/input ratio, N balance, P2O5 balance, works unit per hectare. The preliminary results suggest that these indicators allow to discriminate between different farms on the basis of the productive orientation (cropping classes). In perspective, the use of indicators may enable farmers to improve the management of their farm, evaluating the ecological footprint in order to reduce it gradually

School catering supply chains: study on 5 cases

This study presents accurate data on the school catering systems of five different municipalities which decided to invest on service quality and sustainable development. The aim is to provide a compendium to be considered by other local authorities and then used as an educational tool for drafting new templates for tender specifications. Regional laws as drivers for promoting organic consumption in school canteens and waste reduction through self service systems are two examples of interesting models for sustainable school food catering. This work does not present a unique best practice model but constellations of reference models for each different situation: in such way each municipality can consult the most fit case study and search the best solution according to specific variables

Organising supply chains of organic products for Italian school meals - The case of the province and of the city of Piacenza

The paper is part of the proceedings of an iPOPY seminar. The authors describe, how supply chains of organic school food might be organised in a sustainable way in order to serve high quality food to pupils. They present a best practice case of controlled food chains (filiera controllata) from Italy, the European champion of organic school food. From the province and the city of Piacenza in the region of Emilia-Romagna, we can learn a lot about a short and certified organic food-chain, a wide range of regional and organic products provided through a shared logistic organisation among local partners, and specific tender procedures

Main constraints in developing public organic procurement

The present study investigates how to increase and improve school catering supply chains, to understand hindering factors and their perception in order to reveal drivers and constraints for POP. These include policy implementation instruments, changed values and attitudes, healthy nutrition policies, supply chain bottle necks, premium prices (to producers), successful procurement strategies and certification procedures. This work is based on a two-step survey concerning the Italian school food service system. Initially questionnaires were submitted to a qualified group of 50 producers and 50 caterers (managers of national and international companies of food service for school, local administrators who manage food services for the schools). The results of the questionnaires have subsequently been the basis to plan in-depth interviews with few decision makers who could represent both caterers and producers. The aim of this second step being to view how identified problems could be solved. The results show how the understanding and the acceptance of the organic food concept among the catering staff is crucial for the degree of success in each step of public organic procurement. The introduction of organic food in serving outlets needs appropriate support (such as qualification of key actors and a specific financial support). Other key aspects in this regard are laws and regulations promoting the procurement of quality food, policy interventions tackling more than one aspect of the problem, education programs, calls for tenders, negotiated procurement contracts and quality standards