Producers' Perceptions and Consumers' Behaviour Toward Certified Beans from Integrated Production (IP) in the Brazilian Central Region

Integrated production (IP) is part of the Brazilian government program to promote sustainable agricultural production. IP ensure minimum food quality standards for domestic market, and export. Furthermore, IP is considered a good option to reduce negative environmental impacts of intensive crops in tropical Savannas, including common beans, as a Brazilian staple food. Although its advantages, and the government’s effort to promote IP, few growers are adopting IP. Maybe, the perception about IP usefulness and/or its ease of use is not too clear. Moreover, the production sector is driven by market signs, and there is few information on the consumer's preferences toward IP certified products in Brazil. In this study, we sought to identify some critical factors that can influence the IP adoption in beans' production. Moreover, we sought to verify the consumers’ perceptions and intention of purchasing IP certified beans (hypothetical product). This report comprises four chapters: (1) an introduction illustrating the context in which the research was based; (2) the results on the study of IP adoption based on the Technology Acceptance Model (TAM); (3) the choice experiment results applied to identify consumers preferences and willingness-to-pay (WTP) for IP label; (4) the results on the Theory of Planned Behaviour (TPB) applied to identify consumers’ perception toward IP certified beans. This research contributes with rich information for the beans’ supply chain, providing several insights to growers, retail and other agents, including policy makers. Beans’ production sector seems to be positively intentioned to adopt IP, but further studies should be conducted to test other adoption indicators using TAM model. Surveyed consumers are willing to pay a premium price for IP labelled beans. They showed a positive attitude toward purchasing IP labelled beans. It is an important information to motivate production sector to offer certified beans to the market.

Quantum Correlations in Field Theory and Integrable Systems

In this thesis we will investigate some properties of one-dimensional quantum systems. From a theoretical point of view quantum models in one dimension are particularly interesting because they are strongly interacting, since particles cannot avoid each other in their motion, and you we can never ignore collisions. Yet, integrable models often generate new and non-trivial solutions, which could not be found perturbatively. In this dissertation we shall focus on two important aspects of integrable one- dimensional models: Their entanglement properties at equilibrium and their dynamical correlators after a quantum quench. The first part of the thesis will be therefore devoted to the study of the entanglement entropy in one- dimensional integrable systems, with a special focus on the XYZ spin-1/2 chain, which, in addition to being integrable, is also an interacting model. We will derive its Renyi entropies in the thermodynamic limit and its behaviour in different phases and for different values of the mass-gap will be analysed. In the second part of the thesis we will instead study the dynamics of correlators after a quantum quench , which represent a powerful tool to measure how perturbations and signals propagate through a quantum chain. The emphasis will be on the Transverse Field Ising Chain and the O(3) non-linear sigma model, which will be both studied by means of a semi-classical approach. Moreover in the last chapter we will demonstrate a general result about the dynamics of correlation functions of local observables after a quantum quench in integrable systems. In particular we will show that if there are not long-range interactions in the final Hamiltonian, then the dynamics of the model (non equal- time correlations) is described by the same statistical ensemble that describes its statical properties (equal-time correlations).