66 resultados para glycosidation sur support solide
Resumo:
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 is the first report on Dinoflagellata from lowermost Miocene beds in Portugal (Tagus basin, Lisbon region, exposure at Benfica). Some general data about Dinoflagellata are presented. Descriptions are provided for some forms: Gonyaulacysta tenuitabulata, Spiniferites ramosus, Achomosphaera sp., Hystrichokolpoma rigaudae, Homotriblium cf. pallidum, Cordosphaeridium sp, and Lingulodinium machaerophorum. Lithostratigraphical study of an important section along Circular highway at Benfica has shown that there is a hitherto unknown sedimentary cycle in Lisbon's lowermost Miocene (upper Oligocene?). Pollen and Ostracoda point out to an Lower Aquitanian or even Upper Chattian age for the first Neogene marine transgression in Portugal, previously considered as Upper Aquitanian or Lower Burdigalian.
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A new species, Pokornyella lusitanica (Ostracoda), from the Lower Miocene (Aquitanian) of the Lisbon area, is described. Some palaeoecological data are presented.
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This note is concerned with fish remains from Upper Neogene beds at Farol das Lagostas (and nearby quarry of SECIL) and Baía Farta, mainly recovered by the author in 1960, 1961, 1963 and 1967. For further data see ANTUNES, 1964, pp. 213-215. All the forms identified until now (many of them for the first time) are show in «tableau I». Smaller ones are poorly represented. I. benedeni is provisorily accepted as a distinct species, though it may correspond to a dental morphotype that does exist equally in the extant I. oxyrhinchus (see text): therefore I. benedeni from Farol das Lagostas may after all represent only some dental variations that really belong in the form described as I. cf. oxyrhinchus. The presence of Aprionodon and Hypoprion could not be ascertained: Procarcharodon megalodon, Carcharodon carcharias, Isurus benedeni. Galeocerdo cuvieri, and Carcharhinus sp. I and sp. II are specially discussed. The whole fauna does not correspond either to a very shallow and coastal environment, or to deep waters far away from the coast. It clearly points out to warm waters: an acceptable model would be the fauna from the tropical Atlantic between Northern Angola and Senegal-Cape Verde. The age of this fauna was long regarded as Burdigalian. The data formerly presented (ANTUNES, 1963) that allowed us to ascribe a pliocene age to the uppermost Neogene beds of Farol das Lagostas (Neogene III, ANTUNES, 1964) are reviewed and developed in this paper. This view is corroborated by planctonic foraminifera and stratigraphical data which provide further evidence to prove the presence of miocene beds much younger than Burdigalian, and that some deposits previously correlated to this stage have instead a Plio-Pleistocene age. Fish fauna from Farol das Lagostas is very characteristic, with giant P. megalodon in association with C. carcharias (which predominates, and whose stratigraphical distribution is particularly discussed), and with other very advanced forms like the extant tiger shark, G. cuvieri, enormous I. Benedeni, Hemipristis, and Carcharhinus (whose size largely exceeds the maximum observed with miocene material). With the exception of P. megalodon (extinct) all the other forms show very close affinities, or even identity with modern species. Comparisons with very similar faunas from some South African localities that may also have a Pliocene age are also presented.
Resumo:
This note deals with the stratigraphical and paleontological study of the Palença section on the southern bank of the river Tagus, Portugal, and specially with its coccolithophorids. Three main lithostratigraphical units may be recognized: the lowest one does correspond to the upper part of COTTER's division II, the intermediate one to divisions III and IV-a, the third corresponding to pratically the whole division IV-b, However other and higher levels are also represented. Higher beds are also represented in the same sections; they are less well exposed and were not studied in detail. Caracterisation of biozones on the basis of Coccoliths so far found at Palença section is difficultsince MARTINI's zones have been defined mainly by forms of Discoaster and other genera that are wanting. However we can recognize that the richest assemblage (from beds 17-18, the uppermost layers of blue clays IV-a) may correspond to NN4. This is not in opposition to the results of the study of planctonic foraminifera, that are characteristic of BLOW's N7. Coccoliths from lower beds do not allow at present any valid comparisons.
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The study of Cyprinid fish pharyngeal teeth, collected by M. Telles Antunes in continental "Helvetian" sediments from Póvoa de Santarém, makes possible to demonstrate the occurrence of two distinct species. One remains undetermined. The other belongs to the recent genus Leuciscus CUV. Several dental types of this genus are described and figured as Leuciscus antunesi nov. sp. Palaeoclimatical and palaeoecological interpretations are proposed.
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In Portugal, the Mesozoic lower part is principally composed of conglomeratic, arenitic and pelitic deposits, which are here and there associated with carbonates rocks and evaporites. The Germanic Triassic succession is not observed. The Muschelkalk facies do not exist. Carbonates formation, and some thick evaporites deposits (Keuper facies) are of early Jurassic in age. The thick red beds accumulations deposited in a continental environment are Triassic. In Coimbra area the oldest palynomorphs found are Camian-Norian. In South Portugal (Algarve), the triassic serie must be more complete with a lower Triassic rich in Stegocephales bone-beds.
Resumo:
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.
Resumo:
A new species, Pokornyella lusitanica (Ostracoda), from the Lower Miocene (Aquitanian) of the Lisbon area, is described. Some palaeoecological data are presented.
Resumo:
This note is concerned with fish remains from upper Neogene beds at Farol das Lagostas (and nearby quarry of SECIL) and Baía Farta, mainly recovered by the author in 1960, 1961, 1963 and 1967. For further data see ANTUNES, 1964, pp. 213-215. All the forms identified until now (many of them for the first time) are show in «tableau I». Smaller ones are poorly represented. I. benedeni is provisorily accepted as a distinct species, though it may correspond to a dental morphotype that does exist equally in the extant I. oxyrhinchus (see text): therefore I. benedeni from Farol das Lagostas may after all represent only some dental variations that really belong in the form described as I. cf. oxyrhinchus. The presence of Aprionodon and Hypoprion could not be ascertained: Procarcharodon megalodon, Carcharodon carcharias, Isurus benedeni. Galeocerdo cuvieri, and Carcharhinus sp. I and sp. II are specially discussed. The whole fauna does not correspond either to a very shallow and coastal environment, or to deep waters far away from the coast. It clearly points out to warm waters: an acceptable model would be the fauna from the tropical Atlantic between Northern Angola and Senegal-Cape Verde. The age of this fauna was long regarded as Burdigalian. The data formerly presented (ANTUNES, 1963) that allowed us to ascribe a pliocene age to the uppermost Neogene beds of Farol das Lagostas (Neogene III, ANTUNES, 1964) are reviewed and developed in this paper. This view is corroborated by planctonic foraminifera and stratigraphical data which provide further evidence to proove the presence of miocene beds much younger than Burdigalian, and that some deposits previously correlated to this stage have instead a Plio-Pleistocene age. Fish fauna from Farol das Lagostas is very characteristic, with giant P. megalodon in association with C. carcharias (which predominates, and whose stratigraphical distribution is particularly discussed), and with other very advanced forms like the extant tiger shark, G. cuvieri, enormous I. Benedeni, Hemipristis, and Carcharhinus (whose size largely exceeds the maximum observed with miocene material). With the exception of P. megalodon (extinct) all the other forms show very close affinities, or even identity with modern species. Comparisons with very similar faunas from some South African localities that may also have a Pliocene age are also presented.
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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.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para a obtenção do grau de Mestre em Engenharia Informática.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores
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Emergent architectures and paradigms targeting reconfigurable manufacturing systems increasingly rely on intelligent modules to maximize the robustness and responsiveness of modern installations. Although intelligent behaviour significantly minimizes the occurrence of faults and breakdowns it does not exclude them nor can prevent equipment’s normal wear. Adequate maintenance is fundamental to extend equipments’ life cycle. It is of major importance the ability of each intelligent device to take an active role in maintenance support. Further this paradigm shift towards “embedded intelligence”, supported by cross platform technologies, induces relevant organizational and functional changes on local maintenance teams. On the one hand, the possibility of outsourcing maintenance activities, with the warranty of a timely response, through the use of pervasive networking technologies and, on the other hand, the optimization of local maintenance staff are some examples of how IT is changing the scenario in maintenance. The concept of e-maintenance is, in this context, emerging as a new discipline with defined socio-economic challenges. This paper proposes a high level maintenance architecture supporting maintenance teams’ management and offering contextualized operational support. All the functionalities hosted by the architecture are offered to the remaining system as network services. Any intelligent module, implementing the services’ interface, can report diagnostic, prognostic and maintenance recommendations that enable the core of the platform to decide on the best course of action.
Resumo:
Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores