33 research outputs found
Lead isotope composition and host phases in airborne particulate matter from Budapest, Hungary
Baixas concentrações de macronutrientes beneficiam a propagação in vitro de Vriesea incurvata (Bromeliaceae), uma espécie endêmica da Floresta Atlântica, Brasil
Efeitos da escarificação química e da concentração de nitrogênio sobre a germinação e o desenvolvimento in vitro de Vanilla planifolia Jack ex Andr. (Orchidaceae: Vanilloideae)
Is the lower Duarte Complex (Hispaniola) a remnant of the Caribbean plume-generated oceanic plateau.
Late Jurassic oceanic crust and Upper Cretaceous Caribbean plateau picritic basalts exposed in the Duarte igneous complex, Hispaniola
Four distinct rock units have been recognized near El Aguacate, in the
Janico-Juncalito-La Vega area of the Duarte complex (Dominican
Republic): (1) serpentinites crosscut by numerous diabasic dikes, (2)
basalts interbedded with Late Jurassic ribbon cherts, (3) picrites and
ankaramites relatively enriched in incompatible trace elements, and (4)
amphibolites and gneissic amphibolites chemically similar to Oceanic
Plateau Basalts. Similar Ar-Ar ages of late magmatic amphibole from a
picrite, and hornblende from an amphibolite (86.1 +/- 1.3 Ma and 86.7
+/- 1.6 Ma, respectively), suggest that the Duarte picrites are
contemporaneous with the Deep Sea Drilling Program Leg 15 and Ocean
Drilling Program Leg 126 basalts drilled from the Caribbean oceanic
plateau. These basalts are associated with sediments containing Late
Cretaceous faunas. Sr, Nd, and Pb data show that enriched picrites and
amphibolites are isotopically similar to mafic lavas from previously
described Caribbean plateau and Galapagos hotspot basalts. Major
element, trace element, and lead isotopic features of Late Jurassic
basalts and diabases are consistent with those of normal oceanic crust
basalt. However, these basalts differ from typical N-MORB because they
have lower epsilon Nd ratios that plot within the range of Ocean Island
Basalts. These rocks appear to represent remnants of the Caribbean
Jurassic oceanic crust formed from an oceanic ridge possibly close to a
hotspot. Later, they were tectonically juxtaposed with Late Cretaceous
slices of the Caribbean-Colombian plateau
Caracterização de farinhas de tapioca produzidas no estado do Pará Characterization of tapioca flour obtained in Pará state, Brazil
A farinha de tapioca é um alimento produzido artesanalmente a partir da fécula de mandioca (Manihot esculenta Crantz), amplamente consumida na Região Amazônica. O objetivo deste trabalho foi caracterizar duas farinhas de tapioca produzidas no estado do Pará: uma no Baixo Amazonas e outra na Zona Bragantina. As duas farinhas apresentaram perfis granulométricos distintos e diferença significativa (P 0,05) para a maioria dos parâmetros físico-químicos e tecnológicos analisados. A farinha de tapioca proveniente do Baixo Amazonas apresentou maior umidade (10,7%), em função da maior capacidade de adsorver água, devido a sua maior área específica (menor granulometria). A microscopia óptica com luz polarizada, juntamente com as características dos dois produtos indicou a inexistência de um processo padrão utilizado na produção da farinha de tapioca.<br>Tapioca flour is a typical food produced from cassava starch (Manihot esculenta Crantz), widely consumed in the Amazon Region. The aim of this study was to characterize two tapioca flours produced in Pará State, Brazil one in the West Region and other in Bragantina Area. Both tapioca flour presented distinct particle-size distribution and significant difference (P 0.05) for majority of the physico-chemical and technological parameters. Flour from West Region presented high moisture (10.7%), this due the greater capacity of water adsorption, attributed at its high specific area (smaller particle-size). The optical microscopy with polarized light and the technologic properties of the products did not showed a standard process for the production of tapioca flour