Modelo AC para el despacho combinado de contratos bilaterales y bolsa de energía considerando restricciones de seguridad

Reliability is a key aspect in power system design and planning. Maintaining a reliable power system is a very important issue for their design and operation. Under the new competitive framework of the electricity sector, power systems find ever more and more strained to operate near their limits. Under this new scenario, it is crucial for the system operator to use tools that facilitate an energy dispatch that minimizes possible power cuts. This paper presents a mathematical model to calculate an energy dispatch that considers security constraints (single contingencies in transmission lines and transformers). The model involves pool markets and fixed bilateral contracts. Traditional methodologies that include security constraints are usually based in multistage dispatch processes. In this case, we propose a single-stage model that avoids the economic inefficiencies which result when conventional multi-stage dispatch approaches are applied. The proposed model includes an AC representation of the transport system and allows calculating the cost overruns incurred in due to reliability restrictions. We found that complying with fixed bilateral contracts, when they go above certain levels, might lead to congestion problems in transmission lines.

Familiares de portadores de transtorno mental: vivenciando o cuidado em um centro de atenção psicossocial

Esta investigação teve por objetivo apreender como os familiares de portadores de transtorno mental têm convivido com um serviço de saúde mental. Foi utilizado o método exploratório/descritivo, de natureza qualitativa. Como instrumento de coleta de dados, utilizou-se uma entrevista semiestruturada, sendo sujeitos dessa pesquisa seis familiares que já conviviam há mais de três anos com o adoecimento psíquico. A análise dos dados permitiu inferir que os familiares que acompanham o usuário têm de lidar com um aprendizado que adquiriram na vivência cotidiana e são sujeitos à rejeição de membros da família e da comunidade; com relação ao centro de atenção psicossocial, os familiares se sentem acolhidos em suas queixas, recebendo um atendimento singular; porém, desconhecem os mecanismos para a sua participação social, o que aponta para uma deficiência do serviço, à medida que este deve estimular formas de inserção na comunidade, e da ampliação dos direitos de cidadania dos usuários.

O associativismo como alternativa de desenvolvimento na dinâmica da economia solidária

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Serviço de Referência Virtual: implantação do serviço de chat

Introduction: With the invention of the Internet and the Collaborative Web, libraries had to rethink the way to offer their services. Thus, the U.S. libraries began a search for technological innovations in an effort to bring the library to the user through features that patrons commonly use. The Virtual Reference Service (VRS) through chat and reference services via videoconferencing are features that derived from this search. Objective: This article aims to outline the implementation process of Virtual Reference Services (SRV) libraries in American universities, particularly those for chat, as well as presenting the successful Brazilian experience. This paper also discusses factors to be considered for implementing virtual reference service via chat for libraries wishing to offer the service. Methodology: The research methodology is based on a theoretical search on international and national literature on the subject. The methodology also includes participant observation. Results: In Brazil the implementation of SRV in some university libraries has occurred and according to these institutions, the SRV is a service that benefits the community and puts the library in line with the demands of information technology and communication. Conclusions: It is concluded that online SRV is appropriate to the reality of university libraries in Brazil, since the institutions that offer the service have positive results from their assessments and believe they are adding value to their library.