61 research outputs found
Floating two force component measuring device Patent
Device for measuring two orthogonal components of force with gallium flotation of measuring target for use in vacuum environment
Improved molecular sorbent trap for high-vacuum systems
Closed cycle refrigeration loop in which trays holding molecular sorbent are made to serve as cooling baffles improves the performance of high vacuum systems. High performance is obtained with almost no decrease in pumping speed
Two force component measuring device Patent
Development of two force component measuring devic
Assessment of Gas-Surface Interaction Models for Computation of Rarefied Hypersonic Flow
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76727/1/AIAA-36375-113.pd
Eunotiaceae (Bacillariophyceae) em igarapés da Amazônia Central, Manaus e Presidente Figueiredo, Brasil
Estudos florĂsticos e taxonĂ´micos envolvendo diatomáceas sĂŁo escassos para a regiĂŁo amazĂ´nica. As publicações existentes incluem registros de diatomáceas da AmazĂ´nia brasileira, do Equador, da ColĂ´mbia e do Peru e comumente mostram que Eunotia e Actinella (Eunotiaceae) sĂŁo gĂŞneros bem representados nessa regiĂŁo. A maioria dos igarapĂ©s amazĂ´nicos costuma apresentar potencial hidrogeniĂ´nico (pH) ácido, caracterĂstica aquática que promove o desenvolvimento de uma comunidade tĂpica de diatomáceas, dominada por espĂ©cimes de Eunotiaceae. O objetivo deste trabalho foi providenciar um levantamento florĂstico das espĂ©cies de Eunotiaceae presentes em igarapĂ©s da AmazĂ´nia Central brasileira e registrar os morfotipos de algumas espĂ©cies. Amostras fitoplanctĂ´nicas e perifĂticas foram coletadas em cinco igarapĂ©s na rodovia BR-174, em Manaus e Presidente Figueiredo, em setembro e outubro de 1996 e fevereiro e março de 1997. Lâminas permanentes foram preparadas de acordo com a tĂ©cnica de oxidação lenta para o estudo qualitativo. Vinte e trĂŞs espĂ©cies pertencentes ao gĂŞnero Eunotia e seis ao gĂŞnero Actinella foram determinadas. Chaves dicotĂ´micas de identificação, descrição detalhada, comentários relevantes e ilustrações foram providenciadas para cada táxon determinado. Morfotipos foram documentados para Eunotia zygodon. EspĂ©cies raramente citadas na literatura foram registradas, tais como, Eunotia falcifera e Eunotia rostellata.Floristic and taxonomical studies about diatoms to Amazonian region are commonly well represented by Eunotia and Actinella (Eunotiaceae). The available works include diatom assemblage from Brazilian, Ecuadorian, Colombian and Peruvian Amazonia. The local streams often present acid pH which provides environmental conditions to develop a very particular diatom community dominated by specimens of Eunotiaceae. Thus, the aim of this paper is to give a floristic survey of Eunotiaceae from central Amazonian rivers and to register the typical morphologic frustule variations of some species. Planktonic and periphytic samples were collected from five rivers located at the BR-174 highway, near Manaus and Presidente Figueiredo districts, during 1996 and 1997. Slides were prepared in accordance with the technique of slow oxidation for the qualitative determination. Twenty-three species of Eunotia and six of Actinella were identified. Dicotomic keys, taxonomic comments and photographic illustrations were added. Morphotypes of Eunotia zygodon were registered. Species scarcelly mentioned on diatom literature were registered, such as, Eunotia falcifera and Eunotia rostellata
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