972 resultados para Stamp collecting


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This article aims to present proposals for improvement of key standards and resolutions concerned about the methodology for calculating the indicator of total harmonic voltage distortion, and should contribute to the process of examining the compatibility of potentially disturbing loads in electric power quality in distribution systems. These proposals were drawn from the analysis of results from measurement campaigns conducted in a case study including analysis of the connection of a new induction furnace in a foundry served by a distributor of São Paulo state. A general historical situating the quality of electric energy in the electricity sector is presented, and methodological guidelines and procedures used in experimental trials are shown. The analysis and discussion of results are prepared to answer the main questions that arise during the implementation of standards, resolutions and procedures. © 2011 IEEE.

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Pós-graduação em Agronomia (Horticultura) - FCA

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Piper aduncum L. é uma planta que ocorre na Amazônia Brasileira com elevado teor de óleo essencial e que apresenta propriedades biológicas utilizáveis na agricultura e saúde humana. Com o objetivo de avaliar germoplasma visando ao melhoramento genético e cultivo econômico, realizaram-se coletas (inflorescências, estacas, folhas e ramos finos) em dez municípios da Amazônia Brasileira (Manaus, Marabá, Goianésia, Moju, Belém, Santa Izabel, Americano, Bonito, Santarém Novo e Aveiro). Tomaram-se dados do ambiente, populações e de doze caracteres morfoagronômicos (número de folhas por ramo, comprimento da folha, largura da folha, circunferência do ramo mais velho, altura da planta, número de ramos ortotrópicos, número de ramos plagiotrópicos, comprimento do entrenó, número de espigas por ramo, rendimento de óleo, teor e produção de dilapiol). As inflorescências e estacas foram identificadas e encaminhadas para a UFRA em Belém-PA e, as folhas e ramos finos, para o Museu Paraense Emílio Goeldi-MPEG, para extração do óleo essencial (hidrodestilação). Utilizaram-se estimadores de média, desvio padrão, coeficiente de variação e amplitude total para estudo da variabilidade fenotípica. As matrizes prevalenceram em ambientes antropizados, solos argilosos, condições de drenagem variáveis, terrenos planos e clima Ami, como também predominaram populações definíveis pela agregação dos indivíduos, em terra alta e a pleno sol, serrapilheira, tamanho das populações e presença de plântulas no chão muito variáveis. Os caracteres de maior variabilidade foram número de ramos ortotrópicos, número de espigas por ramo, circunferência do ramo mais velho (morfológicos), teor e produção de dilapiol (agronômicos). Concluiu-se que a espécie apresenta adaptação a diferentes ambientes com relação à vegetação, solo, clima, relevo e drenagem, facilitando o cultivo e domesticação. Há variabilidade morfoagronômica favorecendo a seleção e fitomelhoramento.

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Coordenação de Aprefeiçoamento de Pessoal de Nível Superior (CAPES)

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Scientific collections are important sources of material for many areas of ornithological research. Although firearms (particularly shotguns) have been the standard for avian scientific collecting for more than 100 years, their use is restricted in many areas of the world. We describe a cheap, relatively silent, and effective air shotgun for collecting birds weighing up to 50 g at distances up to 4 m. This air shotgun is capable of shooting birdshot, uses hollow metal rivets connected to plastic straws as shot shells, and represents a simple adaptation of any 0.177 or 0.22 cal single-shot, break-barrel air rifle with at least 25 joules of muzzle energy. This air shotgun will be especially useful for focused sampling of birds (and other small vertebrates) in situations where firearm use or transport is restricted.

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Heavy metal-rich copper mine tailings, called stamp sands, were dumped by mining companies directly into streams and along the Lake Superior shoreline, degrading Keweenaw Peninsula waterways. One of the largest disposal sites is near Gay, Michigan, where tailings have been moved along the shoreline by currents since mining ceased. As a result, the smallest sand particles have been washed into deeper water and are filling the interstitial spaces of Buffalo Reef, a critical lake trout spawning site. This research is the first to investigate if stamp sand is detrimental to survival and early development of eggs and larvae of lake sturgeon, lake trout, and Northern leopard frogs, and also examines if the presence of stamp sands influences substrate selection of earthworms. This study found that stamp sand had significantly larger mean particle sizes and irregular shapes compared to natural sand, and earthworms show a strong preference for natural substrate over any combination that included stamp sand. Additionally, copper analysis (Cu2+) of surface water over stamp sand and natural sand showed concentrations were significantly higher in stamp sand surface water (100 μg/L) compared to natural sand surface water (10 μg/L). Frog embryos had similar hatch success over both types of sand, but tadpoles reared over natural sand grew faster and had higher survival rates. Eggs of lake sturgeon showed similar hatch success and development over natural vs. stamp sand over 17 days, while lake trout eggs hatched earlier and developed faster when incubated over stamp sand, yet showed similar development over a 163 day period. Copper from stamp sand appears to impact amphibians more than fish species in this study. These results will help determine what impact stamp sand has on organisms found throughout the Keweenaw Peninsula which encounter the material at some point in their life history.