Renewable Energy in Urban Low-Income Communities. Case Study of Santa Marta, Rio de Janeiro

Nowadays, 55% of the global population lives in urban areas, a ratio that is estimated to grow to 68% by the end of 2050. Sustainable development depends more and more on the adequate management of urban growth, including the successful planning of basic services, such as electricity. In the city of Rio de Janeiro, Brazil, more than 22% of the population lives in informal settlements, overcrowded areas characterized by low standard housing, poor services and infrastructure, inhabited by impoverished people. Brazilian electricity prices are among the highest in Latin America and have shown high volatility in the last years, mainly due to the strong dependence of the electricity sector on hydro sources, which are subject to climate conditions. Without adequate programs, Brazilian low-income families are obliged to compromise their budget to pay the electricity service. In this context, this study aims to assess from a techno-economic point of view, the use of renewable energy technologies in urban low-income communities, focusing on the case study of Santa Marta, in Rio de Janeiro, with the final objective of identifying both competitive and sustainable systems to provide electricity to the community. Results show that solar PV systems are extremely competitive with the electricity supplied by the grid and they could represent a solution for low-income communities thanks to the implementation of adequate business plans and financing methods

Os 'learner´s dictionaries' do inglês e os 'Lernwörterbücher' do alemão: uma simples transposição de nomes?

It could be said that learner’s dictionaries are the most reliable expression of lexicography in terms of providing the necessary tools to help the learning process of a foreign language. This paper analyses three English learner’s dictionaries in order to establish its stylistic patterns as well as to compare them with four German learner’s dictionaries. Undoubtly, the lexicography of English learner’s dictionaries is a model. However, we argue that this model can not be transfered to German lexicography since each language has its own particularities which demand specific solutions

Different Decomposition Strategies to Solve Stochastic Hydrothermal Unit Commitment Problems

Solving very-large-scale optimization problems frequently require to decompose them in smaller subproblems, that are iteratively solved to produce useful information. One such approach is the Lagrangian Relaxation (LR), a broad range technique that leads to many different decomposition schemes. The LR supplies a lower bound of the objective function and useful information for heuristics aimed at constructing feasible primal solutions. In this paper, we compare the main LR strategies used so far for Stochastic Hydrothermal Unit Commitment problems, where uncertainty mainly concerns water availability in reservoirs and demand (weather conditions). This problem is customarily modeled as a two-stage mixed-integer optimization problem. We compare different decomposition strategies (unit and scenario schemes) in terms of quality of produced lower bound and running time. The schemes are assessed with various hydrothermal systems, considering different configuration of power plants, in terms of capacity and number of units

Comparing Spatial and Scenario Decomposition for Stochastic Hydrothermal Unit Commitment Problems

Solving very-large-scale optimization problems frequently require to decompose them in smaller subproblems, that are iteratively solved to produce useful information. One such approach is the Lagrangian Relaxation (LR), a general technique that leads to many different decomposition schemes. The LR produces a lower bound of the objective function and useful information for heuristics aimed at constructing feasible primal solutions. In this paper, we compare the main LR strategies used so far for Stochastic Hydrothermal Unit Commitment problems, where uncertainty mainly concerns water availability in reservoirs and demand (weather conditions). The problem is customarily modeled as a two-stage mixed-integer optimization problem. We compare different decomposition strategies (unit and scenario schemes) in terms of quality of produced lower bound and running time. The schemes are assessed with various hydrothermal systems, considering different configuration of power plants, in terms of capacity and number of units

Solving Stochastic Hydrothermal Unit Commitment with a New Primal Recovery Technique Based on Lagrangian Solutions

The high penetration of intermittent renewable generation has prompted the development of Stochastic Hydrothermal Unit Commitment (SHUC) models, which are more difficult to be solved than their thermal-based counterparts due to hydro generation constraints and inflow uncertainties. This work presents a SHUC model applied in centralized cost-based dispatch. The SHUC is represented by a two-stage stochastic model, formulated as a large-scale mixed-binary linear programming problem. The solution strategy is divided into two steps. The first step is the Lagrangian Relaxation (LR) approach, which is applied to solve the dual problem and generate a lower bound for SHUC. The second step is given by a Primal Recovery where we use the solution of the LR dual problem with heuristics based on Benders’ Decomposition to obtain the primal-feasible solution. Both steps benefit from each other, exchanging information over the iterative process. We assess our approach in terms of the quality of the solutions and running times on space and scenario LR decompositions. The computational instances use various power systems, considering the different configuration of plants (capacity and number of units). The results show the advantage of our primal recovery technique compared to solving the problem via MILP solver. This is true already for the deterministic case, and the advantage grows as the problem’s size (number of plants and/or scenarios) does. The space decomposition provides better solutions, although scenario one provides better lower bounds, but the main idea is to encourage researchers to explore LR decompositions and heuristics in other relevant problems

Solving Stochastic Hydrothermal Unit Commitment with a New Primal RecoverycTechnique Based on Lagrangian Solutions

The high penetration of intermittent renewable generation has prompted the development of Stochastic Hydrothermal Unit Commitmentc(SHUC) models, which are more difficult to be solved than their thermal-basedccounterparts due to hydro generation constraints and inflow uncertainties.cThis work presents a SHUC model applied in centralized cost-based dispatch, where the uncertainty is related to the water availability in reservoirs and demand. The SHUC is represented by a two-stage stochastic model, formulated as a large-scale mixed-binary linear programming problem. The solution strategy is divided into two steps, performed sequentially, with intercalated iterations to find the optimal generation schedule. The first step is the Lagrangian Relaxation (LR) approach. The second step is given by a Primal Recovery based on LR solutions and a heuristic based on Benders' Decomposition. Both steps benefit from each other, exchanging information over the iterative process. We assess our approach in terms of the quality of the solutions and running times on space and scenario LR decompositions. The results show the advantage of our primal recovery technique compared to solving the problem via MILP solver. This is true already for the deterministic case, and the advantage grows as the problem’s size (number of plants and/or scenarios) does

Efeito da suplementação com minerais injetáveis sobre parâmetros reprodutivos de fêmeas suínas

Orientador: Prof. Dr. Geraldo Camilo AlbertonDissertação (mestrado) - Universidade Federal do Paraná, Setor de Palotina, Programa de Pós-Graduação em Ciência Animal. Defesa: Palotina, 24/07/2014Inclui referênciasArea de concentração : Saúde animalResumo: Avanços crescentes ocorreram na suinocultura, e se devem principalmente a pesquisas em genética, sanidade e nutrição. Neste último caso, dietas cada vez mais precisas visam estimular a fêmea a manifestar sua melhor produção. Porém, pouca atenção tem sido dada ao requerimento e uso de minerais em fêmeas de alta prolificidade. As indicações não levam em consideração fatores importantes como o peso do animal, a fase de gestação, número de partos e a fonte oferecida, se orgânica ou inorgânica. Desta forma, as fêmeas acabam recebendo doses menores do que sua necessidade, prejudicando o número e o peso dos animais nascidos. Sabe-se que os minerais orgânicos tem melhor absorção pela via oral do que minerais inorgânicos, mas, ainda assim, não são totalmente absorvíveis e biodisponíveis. Uma inovadora forma de aplicação de minerais para suínos é a injetável, sendo armazenados em órgão alvo e utilizados quando necessário. Este estudo teve como objetivo realizar a suplementação mineral com minerais injetáveis em fêmeas da puberdade até o segundo parto, com minerais principalmente a base de zinco e selênio. Para isto, foram selecionadas 400 leitoas, 178 para o controle e 176 para receber os minerais. As aplicações ocorreram aos 150 dias, 210 dias de vida da leitoa e após a cobertura, aos 80 dias. As aplicações subseqüentes foram aos 21 e 80 dias pós cobertura. Os resultados demonstraram um incremento significativo (p<0,05) para o total de leitões nascidos e para o número de nascidos vivos, além do aumento do peso ao nascer da leitegada de fêmeas tratadas. Estes resultados podem indicar que a suplementação com minerais injetáveis leva a melhora do número de leitões nascidos bem como a manutenção e aumento do peso da leitegada. Palavras chave: Suínos, Reprodução, Minerais, Zinco, Selênio;Abstract: Increasing advances have occurred in swine production, mainly because of research on genetics, health and nutrition. In this last case, increasingly accurate diets aim to stimulate the female to show its best production. However, little attention has been given to the application and use of minerals in high prolificacy females. The indications do not take into account important factors such as the weight of the animal, stage of pregnancy, number of births and the source offered, if it?s organic or inorganic. Thus, females end up receiving lower doses than they need, decreasing the number and weight of pigs stillborn. It is known that organic minerals have better oral absorption than inorganic minerals, but they are still not fully absorbable and bioavailable. An innovative way of applying minerals for pigs is injectable, in which these minerals are administered by injection and stored in the target organ and used when is needed. This study?s aim was to perform mineral supplementation with injectable minerals in gilts from puberty until the second pregnancy with mainly minerals based of zinc and selenium. For this, there were selected 400 gilts, 178 of control and 176 to receive minerals. Applications occurred at 150 days, 210 days of life and 80 days after hedging. Subsequent applications were at 21 and 80 days after hedging. The results showed a significant increase (p < 0.05) in the total of piglets born and the number of them born alive, besides the tendency of increasing birth weight of treated females? litter. These results may indicate that supplementation with injectable minerals improves litter?s size, as well, maintenance and litter weight increase. Key Word: Swine, Reproduction, Organic Minerals, Zinc, Selenium

Locust bean gum hydrogels are bioadhesive and improve indole-3-carbinol cutaneous permeation: influence of the polysaccharide concentration

The locust bean gum (LBG) is a polysaccharide with thickening, stabilizing and gelling properties and it has been used in the preparation of pharmaceutical formulations. Hydrogels (HGs) are obtained from natural or synthetic materials that present interesting properties for skin application. This study aimed to develop HGs from LBG using indole-3-carbinol (I3C) as an asset model for cutaneous application. HGs were prepared by dispersing LBG (2%, 3% and 4% w/v) directly in cold water. The formulations showed content close to 0.5 mg/g (HPLC) and pH ranging from 7.25 to 7.41 (potentiometry). The spreadability factor (parallel plate method) was inversely proportional to LBG concentration. The rheological evaluation (rotational viscometer) demonstrated a non-Newtonian pseudoplastic flow behavior (Ostwald De Weale model), which is interesting for cutaneous application. The HET-CAM evaluation showed the non-irritating characteristic of the formulations. The bioadhesive potential demonstrated bioadhesion in a concentration-dependent manner. Permeation in human skin using Franz cells showed that the highest LBG concentration improved the skin distribution profile with greater I3C amounts in the viable skin layers. The present study demonstrated the feasibility of preparing HGs with LBG and the formulation with the highest polymer concentration was the most promising to transport active ingredients through the skin