Teores de matéria orgânica em diferentes sistemas de preparo de solo e sucessão de culturas.

Para assegurar a sustentabilidade do uso agrícola do solo e minimizar ações danosas torna-se necessário a adoção de um bom sistema de manejo do solo. O objetivo do trabalho foi avaliar os teores de matéria orgânica em três profundidades (0-10,10-20 e 20-30cm)de um solo cultivado em diferentes sistemas de preparo de solo e sequência de culturas. O experimento instalado em 2007 foi conduzido em esquema de parcelas subsubdivididas 4x4x3, sendo que o fator preparo de solo foi: 1- PRT - preparo tradicional (uma operação com grade aradora e mais uma com grade niveladora), 2 - PRA - preparo alternativo (uma operação de subsolagem), 3 - PDA - plantio direto com um preparo alternativo a cada quatro anos e 4 - PDC - plantio direto contínuo. O fator seqüência de culturas foi: 1) S/F: soja - feijão; 2) S/M: soja ? milho; 3) M/F: milho-feijão; 4) M/M: milho-milho e com três repetições. O PRA apresentou maior teor de matéria orgânica (MO) e houve um decréscimo em MO com o aumento da profundidade com exceção do PRT

Assessment of solar shading strategies in low-income tropical housing: the case of Uganda

Developing countries in tropical and subtropical areas will be the worst hit by climate change. Very little research has been done to assess the impact of climate change on thermal comfort in low-income housing in these regions. The effects of solar shading strategies and solar absorptance properties of walls and roofs on thermal comfort in Ugandan low-income housing are studied in this paper. Various shading strategies including curtains, roof and window overhangs, veranda and trees as well as effects of painting on solar heat gain and thermal comfort are modelled using EnergyPlus software. An adaptive approach for naturally ventilated buildings defined by the European Committee for Standardization standard BS EN 15251:2007 is used to assess the conditions. According to the results, solar shading is less effective in meeting thermal comfort requirements and it should be used in conjunction with other strategies to achieve desirable results. White painting, in contrast, significantly improved the conditions and significantly reduced the risk of overheating. Solar shading proved to be effective during the hottest periods of the year, reducing the risk of extreme overheating by up to 52%

State of the art: Italy

The paper illustrates some aspects of the housing developments built during ‘50/’80 which represents the main part of the Italian building heritage. The main housing building typologies and technologies diffused in Italy are described, furthermore problems related to the multi-stored building blocks, which is the most common building type used for the housing settlements, are analyzed