265 research outputs found
Performance and loads data from a hover test of a full-scale XV-15 rotor
A hover test of a full-scale XV-15 rotor was conducted at the Outdoor Aerodynamic Research Facility at Ames Research Center. The primary objective of the test was to obtain accurate measurements of the hover performance of the original, metal-blade XV-15 rotor system. Data were acquired for rotor tip Mach numbers ranging from 0.60 to 0.73. This report presents data on rotor performance, rotor wake downwash velocities, and rotor loads
Performance and loads data from a hover test of a 0.658-scale V-22 rotor and wing
A hover test of a 0.658-scale model of a V-22 rotor and wing was conducted at the Outdoor Aerodynamic Research Facility at Ames Research Center. The primary objectives of the test were to obtain accurate measurements of the hover performance of the rotor system, and to measure the aerodynamic interactions between the rotor and wing. Data were acquired for rotor tip Mach numbers ranging from 0.1 to 0.73. This report presents data on rotor performance, rotor-wake downwash velocities, rotor system loads, wing forces and moments, and wing surface pressures
Avaliação do efeito de aceleradores de compostagem no desenvolvimento de milho em cultivo sequencial.
O conteúdo de matéria orgânica nos solos tropicais é geralmente baixo e a decomposição é muito favorecida em função das altas temperaturas. O uso de compostos orgânicos é uma alternativa para aumentar o teor de matéria orgânica no solo, além de fornecer nutrientes e estimular o desenvolvimento das culturas. O objetivo deste trabalho foi avaliar o efeito de compostos orgânicos elaborados com diferentes aceleradores de crescimento sobre o desenvolvimento vegetativo de plantas de milho. O desenvolvimento das plantas de milho foi avaliado em vasos, em função da adição de compostos produzidos com os seguintes tratamentos: isolado de fungos nativos de solo da Caatinga, produto comercial contendo bactérias mais leveduras e carvão vegetal, além de um composto sem aditivo e de um tratamento adicional contendo apenas solo. Os compostos orgânicos não afetaram o desenvolvimento vegetativo das plantas, embora tenham reduzido o índice de clorofila nas folhas
Diversidade genética de bactérias isoladas de nódulos de feijão-caupi cultivado em solos com e sem a aplicação de biochar.
Este trabalho foi desenvolvido com o objetivo de avaliar a diversidade genética de rizóbios isolados de nódulos de feijão-caupi [Vigna unguiculata (L.) Walp.] cultivado em solos com e sem a aplicação de biochar como condicionante de solo
Soil greenhouse gases emissions in a goat production system in the Brazilian semiarid region.
In the climate change scenario, studying greenhouse gases (GHG) emissions and measures of mitigation in the Caatinga biome are strategic and may provide a basis for mitigation plans. This study aimed to evaluate the soil CO2, CH4and N2O fluxes, as well as determining an annual baseline for GHG emissions, in a reference site of silvopastoral production system in the Brazilian semiarid region, in order to provide subsidies for future studies on GHG emissions mitigation. The GHG fluxes were monitored over one year, in a buffel grass pasture and in grazed and native Caatinga areas, which are components of a long-term silvopastoral system. The CO2 fluxes ranged from -19.98 to 179.12 mg m-2 h-1 of CO2-C, CH4 fluxes from -76.21 to 113.87 ?g m-2 h-1 of CH4-C, N2O fluxes from -1,043.12 to 471.37 ?g m-2 h-1 of N2O-N and the soil moisture was the main factor limiting the GHG fluxes. The total emissions converted to CO2-equivalent in the anthropized areas were lower than in the native area (65 % for the buffel grass pasture and 741 % for the grazed Caatinga). Therefore, it is possible to affirm that the GHG soil emissions from grazed areas in the Caatinga biome are not as high as in the native Caatinga, what is an important indication of the environmental sustainability of the evaluated silvopastoral syste
Caracterização físico, química do solo sob diferentes sistemas de usos no município de Santa Inês - MA.
Para o estudo da qualidade do solo é necessário analisar as características de natureza física, química e biológica do solo que agem de forma integrada. O objetivo do presente trabalho foi avaliar as suas modificações quando submetido a diferentes sistemas de uso e manejo em Santa Inês-MA. Os sistemas avaliados foram: vegetação nativa (mata de babaçu), vegetação secundária (capoeira), pastagem degradada, e área após remoção da capoeira. Para a caracterização do solo foram realizadas as análises físicas e químicas. Dentre os solos avaliados o único atributo químico que apresentou diferença significativa entre os usos foi o teor de cálcio trocável, que foi maior na pastagem degradada, que nos demais usos. Nos atributos físicos dos solos foram observadas diferenças significativas nos teores de areia e silte, no uso sob pastagem degradada. As áreas de mata nativa, capoeira e área após remoção da capoeira assemelharam-se em todos os outros atributos avaliados
Anthocyanins restore behavioral and biochemical changes caused by streptozotocin-induced sporadic dementia of Alzheimer's type
Aims
The aim of this study was to analyze if the pre-administration of anthocyanin on memory and anxiety prevented the effects caused by intracerebroventricular streptozotocin (icv-STZ) administration-induced sporadic dementia of Alzheimer's type (SDAT) in rats. Moreover, we evaluated whether the levels of nitrite/nitrate (NOx), Na+,K+-ATPase, Ca2 +-ATPase and acethylcholinesterase (AChE) activities in the cerebral cortex (CC) and hippocampus (HC) are altered in this experimental SDAT.
Main methods
Male Wistar rats were divided in 4 different groups: control (CTRL), anthocyanin (ANT), streptozotocin (STZ) and streptozotocin + anthocyanin (STZ + ANT). After seven days of treatment with ANT (200 mg/kg; oral), the rats were icv-STZ injected (3 mg/kg), and four days later the behavior parameters were performed and the animals submitted to euthanasia.
Key findings
A memory deficit was found in the STZ group, but ANT treatment showed that it prevents this impairment of memory (P < 0.05). Our results showed a higher anxiety in the icv-STZ group, but treatment with ANT showed a per se effect and prevented the anxiogenic behavior induced by STZ. Our results reveal that the ANT treatment (100 μM) tested displaces the specific binding of [3H] flunitrazepam to the benzodiazepinic site of GABAA receptors. AChE, Ca+-ATPase activities and NOx levels were found to be increased in HC and CC in the STZ group, which was attenuated by ANT (P < 0.05). STZ decreased Na+,K+-ATPase activity and ANT was able to prevent these effects (P < 0.05).
Significance
In conclusion, these findings demonstrated that ANT is able to regulate ion pump activity and cholinergic neurotransmission, as well as being able to enhance memory and act as an anxiolytic compound in animals with SDAT
Estoques de carbono e fluxo de gases do efeito estufa em agrossistemas no Brasil.
O trabalho objetivou apresentar dados atuais sobre os acúmulos de C no solo e potenciais reduções de emissão de GEE para a atmosfera nos principais agrossistemas no Brasil, incluindo os envolvidos na produção de biodiesel, cana-de-açúcar, mudanças do uso da terra na Amazônia e pastagens
Greenhouse gas emissions and chemical and physical soil attributes of off-season agricultural production systems in the savannah of Maranhão State, Brazil.
Management of agricultural production systems interferes with greenhouse gases (GHG) emissions, thereby altering physical, chemical, and biological attributes of soil; therefore, it is important to understand the relationship between soil attributes and GHG emissions. This study evaluated GHG emissions and their relationship with soil attributes in offseason soybean, maize, brachiaria and eucalyptus production systems. The experiment was carried out in Brejo, Maranhão, Brazil, with soybean (Glycine max), maize (Zea mays), brachiaria (Urochloa ruzizienses), and eucalyptus (Eucalyptus grandis)
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