Caracterização e classificação dos solos do Campo Experimental do Cerrado da Embrapa Amapá, Estado do Amapá.

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Mapeamento de solos das áreas de duas mesobacias hidrográficas no Nordeste paraense.

Este trabalho cumpre parte das necessidades de levantar e caracterizar os solos de duas áreas de mesobacias hidrográficas inseridas no projeto Gestabacias, previstas no diagnóstico do meio biofísico dessas áreas. O Projeto Gestabacias foi elaborado com o intuito de desenvolver uma rede de informações que permita integrar resultados de pesquisa sobre a integridade dos recursos solo, vegetação, água e fauna aquática em mesobacias hidrográficas relacionadas com diferentes sistemas de uso da terra praticados, como subsídio à construção de um modelo de gestão participativa dos recursos naturais nessas bacias. Ao ultrapassar os limites da academia e dos centros de pesquisa, prevê a socialização das informações disponíveis e a participação de diferentes atores envolvidos na elaboração de modelos de gestão dos recursos naturais em bacias hidrográficas localizadas no nordeste do Estado do Pará

Auslander-Buchweitz approximation theory for triangulated categories

We introduce and develop an analogous of the Auslander-Buchweitz approximation theory (see \cite{AB}) in the context of triangulated categories, by using a version of relative homology in this setting. We also prove several results concerning relative homological algebra in a triangulated category \T, which are based on the behavior of certain subcategories under finiteness of resolutions and vanishing of Hom-spaces. For example: we establish the existence of preenvelopes (and precovers) in certain triangulated subcategories of \T. The results resemble various constructions and results of Auslander and Buchweitz, and are concentrated in exploring the structure of a triangulated category \T equipped with a pair (\X,\omega), where \X is closed under extensions and $\omega$ is a weak-cogenerator in \X, usually under additional conditions. This reduces, among other things, to the existence of distinguished triangles enjoying special properties, and the behavior of (suitably defined) (co)resolutions, projective or injective dimension of objects of \T and the formation of orthogonal subcategories. Finally, some relationships with the Rouquier's dimension in triangulated categories is discussed.Comment: To appear at: Appl. Categor. Struct. (2011); 22 page

Lighting and noise levels in compost dairy barns with natural and forced ventilation

The housing system, called compost barn, is attracting the interest of several farmers. It allows dairy cows to remain in free movement inside a shed without any containment partitions like those used in freestall barns. In Brazil the compost barns with open sides are very common, but recently some closed barns with climatic control systems have been implemented. The objective of this work was to evaluate and compare lighting and noise levels in an open compost barn with natural ventilation and in a closed compost barn with a climate control system. The latter one is based on tunnel ventilation: inlet of air trough evaporative cellulose panels and exit through fans placed on the opposite wall. Through analysis of the collected data it was observed that the sound pressure recorded inside both analysed buildings did not exceed the ranges of noise discomfort recommended for the rearing of animals. However, the sound pressure amplitude inside the barn with climate control system was greater than in the open barn. The light intensity was significantly lower in the closed barn when compared to the open barn (84.96 and 1,413.58 lx, respectively). The artificial lighting system distributed throughout the closed barn was not sufficient to maintain brightness within the recommended range for lactating cows. In addition, it was found that in the closed building with forced ventilation, the highest brightness values are located near the exhaust fans

Crystal slow extraction of positrons from DAΦNE: the SHERPA project

The SHERPA project aim is to develop an efficient technique to extract a positron beam from one of the accelerator rings composing the DAΦNE complex at the Frascati National Laboratory of INFN, setting up a new beam line able to deliver positron spills of O(ms) length, excellent beam energy spread and emittance. The most common approach to slowly extract from a ring is to increase betatron oscillations approaching a tune resonance in order to gradually eject particles from the circulating beam. SHERPA proposes a paradigm change using coherent processes in bent crystals to kick out positrons from the ring, a cheaper and less complex alternative. A description of this innovative nonresonant extraction technique is reported in this manuscript, including its performance preliminary estimation

Crystal slow extraction of positrons from the Frascati da φ NE collider

The slow high-efficiency extraction from a ring positron accelerator (SHERPA) project's aim is to develop an efficient technique to extract a positron beam from one of the accelerator rings composing the DAφNE complex at the Frascati National Laboratory of INFN, setting up a new beam line able to deliver positron spills of O(ms) length, excellent beam energy spread and emittance. The most common approach to slowly extract from a ring is to increase betatron oscillations approaching the third order tune resonance to gradually eject particles from the circulating beam. SHERPA proposes a paradigm change for lepton machines using coherent processes in bent crystals to kick out positrons from the ring, a cheaper and less complex alternative. A description of this innovative nonresonant extraction technique is reported in this manuscript, including its performance preliminary estimation

The SHERPA experiment

The SHERPA project aim is to develop an efficient technique for extracting a positron beam from one of the accelerator rings composing the DAΦNE accelerator complex at the Frascati National Laboratory of INFN, setting up a new beam line delivering positron spills of O(ms) length, excellent beam energy spread and emittance. The main idea is to use coherent processes in bent crystals to slowly kick out positrons from the ring, a cheaper and less complex alternative. This non-resonant technique, already successfully used and still developed mainly in hadron accelerators, will provide a continuous multi-turn extraction of a high quality beam. In this manuscript an overview of the whole experiment will be given, describing in particular the crystal extraction principle, the accelerator optics studies, the crystal prototype and its characterization. A first estimation of the crystal extraction performance at DAΦNE is also reported

Mapeamento detalhado dos solos da Fazenda Experimental da Embrapa Amazônia Oriental em Tomé-Açu, PA.

Este trabalho reveste-se de grande importância no que tange ao levantamento de recursos naturais nessa Fazenda Experimental, com informações sobre caracterização, classificação taxonômica e mapeamento dos solos, em escala de detalhe. Os resultados deste trabalho apresentam potencialidade para dar suporte às pesquisas agronômicas aplicadas não apenas na propriedade analisada, mas igualmente em áreas com condições edafoclimáticas semelhantes, no contexto das ações de transferência de tecnologias desenvolvidas pela Embrapa Amazônia Oriental.bitstream/item/109987/1/DOC-405.pd