692 resultados para Unconsolidated Sands
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FILTER is an innovative, CSIRO developed system for treating effluent using high rate land application and subsequent effluent recapture via a closely spaced, subsurface drainage network. We report on the summer performance of a FILTER system established in a subtropical environment on a relatively impermeable swelling clay soil underlain by a deep regional water table. Using secondary treated sewage effluent, the FILTER system produced effluent of tertiary nutrient standards (less than or equal to5 mg/L TN; less than or equal to1 mg/L TP), with salinity levels suitable for subsequent irrigation reuse (EC less than or equal to2.5 dS/m). Removal of faecal coliforms was considerably less effective. The hydraulic loading rate achieved was about two and a half times larger than conventional irrigation demand, but this was associated with high deep percolation losses (e 3 mm/day). Comparisons are made with the original FILTER system developed and tested by Jayawardane et al. in temperate Australia. Suggestions are made for modifications to, and further testing of FILTER in a subtropical environment.
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Chemical investigations of some Stephania species native to Australia and reportedly employed by Aboriginal people as therapeutic agents. are described. The alkaloids from the forest vines Stephania bancroftii F.M. Bailey and S. aculeata F.M. Bailey (Menispermaceae) have been isolated and characterised. The major alkaloids in the tuber of the former species are (-)-tetra-hydropalmatine and (-)-stephanine, whereas these are minor components in the leaves, from which a C-7 hydroxylated aporphine has been identified. The major tuber alkaloids in S. aculcata are (+)-laudanidine, and the morphinoid, (-)-amurine, whose absolute stereochemistry has been established by X-ray structural analysis of the methiodide derivative. No significant levels of alkaloids were detected in S. japonica. Complete and unambiguous H-1 and C-13 NMR data are presented for these alkaloids. (C) 2003 Elsevier Ltd. All rights reserved.
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Levantamentos sonográficos desenvolvidos em duas áreas da plataforma interna adjacente ao estado do Espírito Santo revelam formas de fundo cuja origem é fortemente relacionada a eventos de tempestades. Estas são caracterizadas por alternâncias de bandas de areias finas sobrepostas, de forma alternada, a um fundo de areias grossas, gerando manchas de areias grossas intercaladas abruptamente com faixas de areias finas a profundidades de 25-30 m para GUA e de 05-08 m para BES. Em ambas as áreas as faixas de areias grossas apresentam marcas de ondulação geradas por ondas com orientação levemente paralela a linha de costa. A sedimentologia de GUA é composta por areias finas a muito finas lamosas carbonáticas com cascalhos siliciclásticos e a de BES por areias grossas e médias com cascalhos biodetríticos. Desta forma, é clara a ação de correntes/ondas de tempestade no fundo marinho de GUA e de BES; porém, a classificação quanto ao comportamento hidrodinâmico e ao transporte de sedimento é necessária para as estimativas sobre a formação, transporte e manutenção das feições encontradas.
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A variabilidade natural dos solos torna complexo o conhecimento de suas propriedades na elaboração de projetos geotécnicos, sendo a determinação da resistência ao cisalhamento não drenada um parâmetro importante nas análises de estabilidade de solos moles. Os ensaios de laboratório de cone e palheta, não convencionais, os ensaios de campo de palheta e piezocone e os ensaios de compressão simples e triaxial não adensado e não drenado foram utilizados para mensurar a resistência não drenada de uma camada de argila marinha mole localizada na planície costeira central brasileira. Os ensaios de laboratório foram realizados em amostras indeformadas coletadas com amostradores de pistão estacionário em vertical próxima à realização dos ensaios de campo. O sítio foi investigado preliminarmente por sondagens de simples reconhecimento, sendo apresentado o perfil estratigráfico por meio de modelagem computacional. Foram também realizados ensaios para caracterização física (análise granulométrica, teor de umidade, limites de liquidez e plasticidade, densidade real dos grãos) e mineralógica (difração de raios X), e ensaios de adensamento para obtenção do histórico de tensões e classificação de qualidade das amostras indeformadas. Os valores de resistência não drenada obtidos pelos ensaios de laboratório foram comparados ao perfil contínuo de resistência determinado empiricamente pelo ensaio de piezocone, com fator de cone Nkt calibrado pelo ensaio de palheta de campo, apresentando boa concordância, com a variabilidade natural do solo influenciando de forma preponderante a qualidade das amostras na variação entre os resultados. Os valores de resistência obtidos pelos ensaios de laboratório de cone e palheta foram comparados entre si, apresentando boa compatibilidade. Ambos, quando comparados ao ensaio de palheta de campo, não apresentaram boa concordância. Os resultados de resistência obtidos pelos ensaios de compressão simples e triaxial apresentaram boa compatibilidade com os resultados do ensaio de laboratório de cone, o que não ocorreu com os resultados do ensaio de laboratório de palheta. Na comparação entre a resistência normalizada pela tensão de sobreadensamento obtida pelos diversos métodos e algumas correlações empíricas da literatura internacional, foi observado para as amostras de solo com índice de plasticidade superior a 60% boa concordância com as correlações de Mesri (1975) e Jamiolkowski et al (1985). Os ensaios não convencionais apresentaram boa confiabilidade, que aliado a simplicidade e agilidade de execução, justificam a difusão destes na prática da investigação geotécnica brasileira como método alternativo para complementar e dar suporte às estimativas de resistência não drenada de solos moles.
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This paper aims to cast some light on the dynamics of knowledge networks in developing countries by analyzing the scientific production of the largest university in the Northeast of Brazil and its influence on some of the remaining regional research institutions in the state of Bahia. Using a methodology test to be employed in a larger project, the Universidade Federal da Bahia (UFBA) (Federal University of Bahia), the Universidade do Estado da Bahia (Uneb) (State of Bahia University) and the Universidade Estadual de Santa Cruz (Uesc)'s (Santa Cruz State University) scientific productions are discussed in one of their most traditionally expressive sectors in academic production - namely, the field of chemistry, using social network analysis of co-authorship networks to investigate the existence of small world phenomena and the importance of these phenomena in research performance in these three universities. The results already obtained through this research bring to light data of considerable interest concerning the scientific production in unconsolidated research universities. It shows the important participation of the UFBA network in the composition of the other two public universities research networks, indicating a possible occurrence of small world phenomena in the UFBA and Uesc networks, as well as the importance of individual researchers in consolidating research networks in peripheral universities. The article also hints that the methodology employed appears to be adequate insofar as scientific production may be used as a proxy for scientific knowledge.
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O presente estudo diz respeito a um trabalho de pesquisa no âmbito de uma Tese de Mestrado incluída no segundo ciclo de estudos do curso de Engenharia Geotécnica e Geoambiente, realizado sobre as condições de desidroxilação para a obtenção de metacaulino com propriedades cimentíceas, a partir da fracção argilosa proveniente dos finos residuais da produção de areias de natureza granítica. O produto resultante da alteração e desintegração dos feldspatos constituintes dos granitos são ricos em caulinite. Na natureza e em particular no Norte de Portugal, existem significativos depósitos cauliníticos com características potenciadoras para a produção de metacaulino. O metacaulino utilizado neste estudo foi obtido de uma amostra de argila submetida a 750oC, por um período de tempo de 30 minutos, processo que permitiu a desidroxilação quase total da matéria-prima, transformando esta numa fase amorfa e irreversível, com propriedades pozolânicas. Os metacaulinos, também conhecidos por geopolímeros, são produtos de fácil produção utilizando uma matéria-prima abundante e proporcionam a obtenção de novos produtos que permitem a substituição parcial do cimento Portland normal na composição das pastas de betão, com vantagens significativas no comportamento mecânico e na resistência aos agentes atmosféricos. Neste estudo são apresentados os resultados dos ensaios de caracterização da matéria-prima, das condições de calcinação e do produto resultante da desidroxilação, nomeadamente a determinação da pozolanicidade e das características fundamentais para a aplicabilidade do produto. No âmbito da especialidade de Georrecursos, consideramos que este trabalho está perfeitamente adequado, já que, para além do estudo para o conhecimento das propriedades da matéria-prima, foi possível, através das alterações introduzidas com o tratamento térmico, obter um novo produto, cuja utilização terá importantes reflexos na sustentabilidade dos recursos naturais e sua utilização.
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Trabalho de Projeto para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização em Estruturas
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de Edificações
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According to an ancient folkloric legend, Our Lady, stepping down from the sea, would have rided on a mule to the platform above the cliffs named Pedra da Mua at Lagosteiros'bay, near Espichel cape. Mule's footprints, regarded by fishermen as evidence, would be clearly recognizable on exposed surfaces of the rocks. Indeed there are footprints but from Dinosaurs of latest Jurassic, Portlandian age, this spectacular locality being specially rich in giant Sauropod tracks (that have seldom been found elsewhere in Europe). As we proceeded to its study, another locality with Dinosaur footprints, Lower Cretaceous (Hauterivian) in age, was found on the northern cliffs at Lagosteiros. It is probably the richest one in european Lower Cretaceous and the only of this age known in Portugal, so we decided to give priority to its study. Dinosaur tracks have been printed on calciclastic sands in a lagoonal environment protected by fringing coral reefs. There have been emersion episodes; beaches were frequented by Dinosaurs. Later on, the marine barremian ingression restablished a gulf and such animals could not come here any more. Under a paleogeographical viewpoint, the evidence of a marine regression near the end of Hauterivian is to be remarked. Five types of tracks and footprints have been recognized: - Neosauropus lagosteirensis, new morphogenus and species, tracks from a giant Sauropod, perhaps from Camarasaurus; with its proportions the total length of the author would be about 15,5 m. These are the only Sauropod tracks known till now in Europe's Lower Cretaceous. - tracks from a not so big quadruped, maybe a Sauropod (young individual?); however it is not impossible that they were produced by Stegosaurians or Ankylosaurians. -Megalosauropus (?Eutynichnium) gomesi new morphospecies, four Theropod tracks most probably produced by megalosaurs. - Iguanodon sp., represented by some footprints and specially by a set corresponding to the feet and tail from an individual standing in a rest position. - problematical, quite small-sized biped (maybe an Ornithopod related to Camptosaurus). Evidence points to a richer fauna than that known in barremian "Dinosaur sandstones" from a nearby locality, Boca do Chapim. Lagosteiros' association clearly indicates the predominance of herbivores, which required large amounts of vegetable food in the neighbourhood. This is an indirect evidence of the vegetal wealth, also suggested by associations of plant macrofossils, polen and spores found in early Cretaceous sediments at the same region. The relatively high proportion of Theropoda is related to the wealth of the whole fauna, which comprised a lot of the prey needed by such powerful flesh-eaters. The evidence, as a whole, points out to a warm and moist climate. All the tracks whose direction could be measured are directed to the southern quadrants, this being confirmed by the approximative direction of other footprints. Massive displacements (migration?) could take place during a brief emersion episode. This may result from the ingression of barremian seas, flooding the region and restablishing here a small gulf. Even if the arrival of the waters damaged certain footprints it has not destroyed them completely, thus allowing the preservation of such evidence from a remote past.
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This study deals with mastodont teeth found near Lisbon in Lower Langhian (lower Middle Miocene) fluviatile, feldspathic sands (Vb division). Conclusions are as follows: 1. Tetralophodont molars (even if at a still primitive stade of the tetralophodont condition) do exist at least since lower Langhian times, and not only since late Middle Miocene as was previously known. 2. Tri- and tetralophodont structures may (and indeed do) coexist in the same individual: such examples do not correspond to transitional forms, but instead to a mosaic of juxtaposed characters (however this does not mean there are no transitional forms in other instances). 3. So these structures coexisted in a population not yet genetically separated beyond fertile cross-breeding, i.e. beyond species' level. 4. Origin of the tetralophodont molar was due to some mutation (s). but without crossing species, limits and even more genus'ones. 5. At this times probably soon after the first appearance of tetralophodont mutants, animals with such characters were a small but significant minority among the population (17% if account is taken on D4's: only 2% after M2's). 6. There was not then any direct and clear correlation between number of lophs (transversal crests) and tooth size, even if the increase of such number goes along with length's increase. 7. Dimensions (length in special) in tetralophodont teeth tend to exceed those in «normal» trilophodont teeth, this being particularly clear in D4, even if there is no clear distinction: the situation is quite the same, maybe less marked, with the M2. 8. According to the preceding conclusions there are no reasons to segregate different taxa among such mastodont population on the grounds of the presence in D4, M1 and M2 of 3 or 4 crests (this character being regarded as diagnostic of the genus Tetralophodon). 9. On the contrary, if any natural (in biological sense) classification is disregarded and a morphological parataxonomy is adopted there should be considered both Gomphotherium angustidens and Tetralophodon sp.: however this is absolutely not our opinion.
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This paper reports some research work that has been done to support Geological Survey's field work for the 1:50.000 Carta Geológica de Portugal, (sheets 19-C Figueira da Foz and 19-D Coimbra-Lousã). Its main purpose was to establish the age of some continental formations. At Cerâmica do Mondego, Ld.ª near Taveiro, two series were observed. The lower one is mainly pelitic, montmorillonite being predominant. It also includes some sandy beds and channel deposits with high energy sediments (conglomerate with limestone pebbles). The upper series lies unconformably upon the former, and there is a neat discontinuity surface between the two. It mainly consists of sands, kaolinite being the most abundant of the clay minerals. This seems to indicate an intensive weathering, an acid, well drained environment and transportation by quite high energy running waters. No fossils were recorded. Preliminary paleontological results are presented, along with some data concerning other localities (Aveiro, etc.). Fossils found in the lower series are: gastropoda (Bulimus gaudryi, TV. 15 bed), several vertebrates (TV. 18), fishes (TV. 19?) and plants (TV. 19-TV. 24). Vertebrata belong to the same fauna as that from Vizo, Aveiro, etc. The presence of mammals is most important as only a single tooth was previously Know in Europe (Southern France) in Late Cretaceous formations. Elsewhere there are some mammalian remains in Peru besides the rich assemblages found in the USA and Mongolia. Plants are representative of the «Debeya flora» well known at several localities in Beira Litoral province, in «Buçaco sandstones», and in Lisbon's «Basaltic Complex». The most important stratigraphical conclusion is that the lower series is Upper Campanian and/or Maastrichtian in age, and not Tertiary as sometimes it has been considered. As at Aveiro, «Bebeya flora» occurs in-beds somewhat higher than those with the Aveiro-Vizo-Taveiro vertebrate fauna. Correlation with other «Debeya flora» localities are now more clear. Data concerning Taveiro lower series, in the whole, point out to a rather warm (and moist?) environment in an occasionally (seasonally?) flooded region.
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This study deals with mastodont teeth found near Lisbon in Lower Langhian (lower Middle Miocene) fluviatile, feldspathic sands (Vb division). Conclusions are as follows: 1. Tetralophodont molars (even if at a still primitive stade of the tetralophodont condition) do exist at least since lower Langhian times, and not only since late Middle Miocene as was previously known. 2. Tri- and tetralophodont structures may (and indeed do) coexist in the same individual: such examples do not correspond to transitional forms, but instead to a mosaic of juxtaposed characters (however this does not mean there are no transitional forms in other instances). 3. So these structures coexisted in a population not yet geneticaliy separated beyond fertile cross-breeding, i.e. beyond species'level. 4. Origin of the tetralophodont molar was due to some mutation (s). but without crossing species, limits and even more genus' ones. 5. At this times probably soon after the first appearance of tetralophodont mutants, animals with such characters were a small but signifiant minority among the population (17% if account is taken on D4's: only 2% after M2's). 6. There was not then any direct and clear correlation between number of lophs (transversal crests) and tooth size, even if the increase of such number goes along with length's increase. 7. Dimensions (length in special) in tetralophodont teeth tend to exceed those in «normal» trilophodont teeth, this being particularly clear in D4, even if there is no clear distinction: the situation is quite the same, maybe less marked, with the M2. 8. According to the preceding conclusions there are no reasons to segregate different taxa among such mastodont population on the grounds of the presence in D4, M1 and M2 of 3 or 4 crests (this character being regarded as diagnostic of the genus Tetralophodon). 9. On the contrary, if any natural (in biological sense) classification is disregarded and a morphological parataxonomy is adopted there should be considered both Gomphotherium angustidens and Tetralophodon sp.: however this is absolutely not our opinion.
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This paper reports some research work that has been done to support Geological Survey's field work for the 1:50.000 Carta Geológica de Portugal, (sheets 19-C Figueira da Foz and 19-D Coimbra-Lousã). Its main purpose was to establish the age of some continental formations. At Cerâmica do Mondego, Lda. near Taveiro, two series were observed. The lower one is mainly pelitic, montmorillonite being predominant. It also includes some sandy beds and channel deposits with high energy sediments (conglomerate with limestone pebbles). The upper series lies unconformably upon the former, and there is a neat discontinuity surface between the two. It mainly consists of sands, kaolinite being the most abundant of the clay minerals. This seems to indicate an intensive weathering, an acid, well drained environment and transportation by quite high energy running waters. No fossils were recorded. Preliminary paleontological results are presented, along with some data concerning other localities (Aveiro, etc). Fossils found in the lower series are: gastropoda (Bulimus gaudryi, TV. 15 bed), several vertebrates (TV. 18), fishes (TV. 19?) and plants (TV. 19-TV. 24). Vertebrata belong to the same fauna as that from Vizo, Aveiro, etc. The presence of mammals is most important as only a single tooth was previously know in Europe (Southern France) in Late Cretaceous formations. Elsewhere there are some mammalian remains in Peru besides the rich assemblages found in the USA and Mongolia. Plants are representative of the «Debeya flora» well known at several localities in Beira Litoral province, in «Buçaco sandstones», and in Lisbon's «Basaltic Complex». The most important stratigraphical conclusion is that the lower series is Upper Campanian and/or Maastrichtian in age, and not Tertiary as sometimes it has been considered. As at Aveiro, «Bebeya flora» occurs in-beds somewhat higher than those with the Aveiro-Vizo-Taveiro vertebrate fauna. Correlation with other «Debeya flora» localities are now more clear. Data concerning Taveiro lower series, in the whole, point out to a rather warm (and moist?) environment in an occasionally (seasonally?) flooded region.
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This paper presents a resume of the results achieved by researchers of the Centro de Estratigrafia e Paleobiologia da U. N. L. on the Neogene of Algarve, since 1977. The detailed study of several profiles as well as that af calcareous nannoplanton, planktonic foraminifera, ostracoda, fishes and mammals allowed to obtain data and correlation elements leading to a new interpretation of the Miocene of Algarve. It was possible to date and to characterize the following units: a) Carbonate formation of Lagos-Portimão, of marine facies, ascribed to the Lower Miocene (Aquitanian? and mainly Burdigalian), possibly attaining the Lower Langhian. b) Essentially arenaceous series of continental facies with a marine intercalation of Arrifão, Olhos de Água and Auramar Hotel beach, middle Miocene (Langhian-Serravallian) in age. c) Marine (tripoli, conglomerates, sands and limestones) deposits of Tunes-Mem Moniz, Ponte das Lavadeiras (Faro), Arroteia (Fuzeta) and Luz de Tavira, corresponding, at least partially, to the first part of the upper Miocene (Lower Tortonian). d) Cacela formation with three members: The lower member (conglomerates and sands), the middle (yellow silts) and the upper ones (gray silts), uppermost Tortonian and mainly Messinian in age. An interpretation of the tectonic and paleogeographic evolution of the portuguese littoral during the Miocene is also presented considering its insertion in the meridional part of the Peninsula (Guadalquivir depression, Betic massif basins and in the spanish Levant in general). Comparisons among the Neogene vulcanism of this region and similar manifestations documented in Algarve (basanite of Figueira-Portimão, etc) are established.