1,721,534 research outputs found
Energy upper bound for structurally-stable N-passive states
Full text linkPassive states are special configurations of a quantum system which exhibit no energy decrement at the end of an arbitrary cyclic driving of the model Hamiltonian. When applied to an increasing number of copies of the initial density matrix, the requirement of passivity induces a hierarchical ordering which, in the asymptotic limit of infinitely many elements, pinpoints ground states and thermal Gibbs states. In particular, for large values of N the energy content of a N-passive state which is also structurally stable (i.e. capable to maintain its passivity status under small perturbations of the model Hamiltonian), is expected to be close to the corresponding value of the thermal Gibbs state which has the same entropy. In the present paper we provide a quantitative assessment of this fact, by producing an upper bound for the energy of an arbitrary N-passive, structurally stable state which only depends on the spectral properties of the Hamiltonian of the system. We also show the condition under which our inequality can be saturated. A generalization of the bound is finally presented that, for sufficiently large N, applies to states which are N-passive, but not necessarily structurally stable.Passive states are special configurations of a quantum system which exhibit no energy decrement at the end of an arbitrary cyclic driving of the model Hamiltonian. When applied to an increasing number of copies of the initial density matrix, the requirement of passivity induces a hierarchical ordering which, in the asymptotic limit of infinitely many elements, pinpoints ground states and thermal Gibbs states. In particular, for large values of N the energy content of a N-passive state which is also structurally stable (i.e. capable to maintain its passivity status under small perturbations of the model Hamiltonian), is expected to be close to the corresponding value of the thermal Gibbs state which has the same entropy. In the present paper we provide a quantitative assessment of this fact, by producing an upper bound for the energy of an arbitrary N-passive, structurally stable state which only depends on the spectral properties of the Hamiltonian of the system. We also show the condition under which our inequality can be saturated. A generalization of the bound is finally presented that, for sufficiently large N, applies to states which are N-passive, but not necessarily structurally stable
Multi-actor platform as a tool to enhance networking of sustainable socio-ecological food systems
No full textThe sustainability of food systems is a central issue in academic and political debate at a national and global level. Involving the various actors in food systems through a multi-actor platform approach is increasingly recognized as a way to promote sustainability because it is a strategy capable of ensuring resilience and an effective mechanism to guarantee the co-creation of knowledge and the definition and implementation of innovation. In order to ensure that the actors/ stakeholders involved are an authentic reflection of the food system, understood as a socio-ecological system i.e. the result of interactions between the socio-economic and ecological components, it is essential to use analytical tools that allow a multidisciplinary approach and that can act as devices for knowledge co-creation and promoting of collaborative approaches. This paper uses a modified version of the SES framework, designed to allow the integration of a range of collaboration behavioural factors for sustainable agri-food chains. The objective is to strengthen the analysis of the structural aspects of SES with assessment of the behavioural factors that can significantly influence the path of sustainable transformation that the SES could undertake. The study analyses the implementation of a good practice multi-actor collaboration and gives an ex ante evaluation of the adaptive mechanisms needed to activate an effective transfer, considering: - the structural characteristics of the agri-food socio-ecological systems involved in the "re-use of good practice"; - the quality and density of behavioural factors present in the socio-ecological systems involved in the "re-use of good practice". The "re-using" socio-ecological systems are all quite different, which makes the challenge of adapting the innovation more complicated. The wine producing systems involved show different levels of aggregation and capacity for adding value. There is a high risk that the costs of implementing the innovation will fall principally to the farmers, while the increase in value generated will not. For this reason, it is important to guarantee, through the initial design and subsequent implementation of the multi-actor platform, that the platform can express, recognize, and address these kinds of challenges
Participatory approach to a place-based sustainable rural development: E-market platform for a resilient Agri-food chain
No full textThe paper reports the experience of a participatory process for the definition of a Local Action Group (LAG) rural development strategy in the southern Italian region of Campania, carried out under the RDP 2014-2020. A number of rural labs for resilient communities were organised involving key actors from agri-food chains, the rural tourism sector, consumers and local institutions. As in many rural areas, the principal challenge facing local farms in the territory is accessing larger distribution channels given their small size. The participatory process aimed to address this challenge and achieved two important results; firstly, the creation of a product-local identity environment that led to the conception of a virtual E-market platform, negotiated among the different stakeholders, with an aim to promote direct sales of local agri-food products between quality conscious consumers and local producers via a smartphone app; secondly, a more closely connected agri-food chain as all participants in the chain, including regional policy-makers, agencies and other key stakeholders, have access to up-to-date and explicitly localised information on the key driving forces they need to consider to ensure the sustainability of policies and programmes relating to rural development
An iterative approach for knowledge production in the agricultural systems and insights for is development
No full textThere is motivation in many rural areas and communities to resolve the issues slowing achievement of a sustainable future, and to embrace the concept of the circular economy for agro-food systems. Increased consumption of resources is not an option and therefore best use must be made of capital, incorporating the "reduce, re-use, recycle" mantra. Research projects addressing sustainable land use can help to accomplish this aim, and the studies have demonstrated that stakeholders may be helped to understand and act on new knowledge especially if they are involved in more than one project. This is because they gain confidence to evaluate research ideas in the light of their own experience. In the Basilicata region of southern Italy there has been a succession of research projects since the 1990s to study the processes of land degradation and appropriate technologies to combat the risk of desertification. Most recently, the attitudes and perceptions of groups of cereal farmers included in both the DESIRE and REACT projects, or the REACT project alone, were compared using a Questionnaire, and the results highlighted the success of the iterative approach. This is an important finding, and can encourage understanding and action to overcome constraints and support the circular economy in agro-food systems
Peasant agriculture and part-time farming: use of resources and landscape effects in a rural area of Southern Italy
No full textLo sviluppo rurale e le OCM nella nuova programmazione 2000-2006: aspetti innovativi per le aziende agricole
No full textBioconverter insects: A good example of circular economy, the study case of hermetia illucens
No full textThe production cycle based on extraction, transformation, production, consumption and waste has not been sustainable for years. The goal is to have production cycles capable of self-regeneration, and therefore to identify a new way of managing byproducts is needed, one that would turn them into a resource. In the production cycle of the food industry, losses and waste account for about 1,3 billion of tons a year, and thus around 1/3 of world production for human consumption. Insects can represent a valid solution to the reuse and valorization of food industry by-products. In environmental and economic fields, an innovative application is offered by the capacity of some insects to bioconvert waste material into valuable products. Bioconverter insects can valorize organic waste from the agrifood industry through bioconversion. This process allows to obtain numerous products of high biological and economic value: proteins and lipids of animal origin, chitin and residues from the bioconversion process (frass of insect and partially digested organic material, rich in in uric acid and chitin, comparable to soil conditioner for agriculture and therefore usable for crop fertilization). Proteins and lipids deriving from some insect species could be used for feed production, and lipids can be exploited for the production of biodiesel or could find application in cosmetics field. Moreover, insect's chitin and its derivative chitosan can find many possible applications in agricultural, biomedical, pharmaceutical and industrial fields as well as in wastewater treatment. The breeding of insects for animal feed and as an alternative source of energy could represent one of the solutions to be adopted in the future. To date, in Europe the larval biomass obtained from bioconversion process can be marketed for the feeding of game animals, reptiles, fur animals and other insectivorous species (EU Reg. 68/2013, EU Reg. 142/2011); they can also be transformed into processed animal proteins (PAP) and then in flours with high nutritional content, to replace or supplement the protein and lipid quotas present in conventional feeds. The specific conditions of processing, production, storage, transport and use of insect flour for aquaculture (fish farming) has been governed by the European Regulation 2017/893 that allows the use of proteins for fish feed derived only from seven species, including the dipteran Hermetia illlucens. In the present paper, we describe the sustainable use of H. illucens to bioconvert agrifood by-products and produce proteins, lipids, chitin and its derivatives; furthermore, we shall outline their applications in the view of a zero-waste circular economy
Modelli distributivi emergenti: una possibilità per le imprese non inserite sul mercato?
No full textCartagine, la Calabria ed il Levante mediterraneo
No full textLa rassegna, condotta sull'edito, in particolare sui rinvenimenti anforici e su quelli monetali, evidenzia alcuni tramiti Egitto-Calabria che possono aver avuto come vettore Cartagine punic
Local food production for local consumption: Why is it so hard to achieve? A case study from a small UK Transition Initiative
Full text linkThe Transition Mayfield (UK) group ran a Local Food project to raise awareness in the local community about the importance of developing local food production and consumption networks; strengthening the local economy and fostering collaboration and skill sharing. The discussion reveals number of factors that were not addressed: growers can lack the additional energy and skills needed to market their produce locally; the community already has very active social networks and the Transition group could not add anything to it; there is a complex relationship between shopkeepers that determines which shop sells what produce. The paper shows that, when trying to promote local food production for local consumption, attention has to be paid and an understanding gained of the motivation and constraints that operate in every part of the network
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