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Sample records for extensional brasiliana correlata

  1. Geochronology Intermediary Laboratory implantation at the Rio Grande do Norte Federal University: the dating of the Serrinha Granitoid (RN) and the correlate Brasiliana extensional deformation; Implantacao do Laboratorio Intermediario de Geocronologia na UFRN: a datacao do granitoide de Serrinha (RN) e da deformacao extensional brasiliana correlata

    Energy Technology Data Exchange (ETDEWEB)

    Macedo, Maria Helena F.; Sa, Emanuel F. Jardim de; Souza, Zorano S. [Pernambuco Univ., Recife, PE (Brazil). Nucleo de Pesquisa em Geodinamica e Geofisica; Mendes, Franklin S. [Pernambuco Univ., Recife, PE (Brazil). Curso de Quimica; Ramalho, Karlos A.C. [Pernambuco Univ., Recife, PE (Brazil). Curso de Geologia

    1997-12-31

    The article describes the activities developed by the Geochronology Intermediary Laboratory at the Federal University of the Rio Grande do Norte, a Brazilian university, where there were the preoccupation of establishing strategies for a geochronological development. It relates the Rubidium-Strontium (Rb/Sr) and Samarium-Neodymium (Sm/Nd) methods, describing the analysis realized in these methodologies. Afterward, it presents the geological and petrographic situation of the Granitoide de Serrinha, located at Rio Grande do Norte State, Brazil and its geochronological data 8 refs., 2 figs.

  2. Environmental influence on population dynamics of the bivalve Anomalocardia brasiliana

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    Corte, Guilherme Nascimento; Coleman, Ross A.; Amaral, A. Cecília Z.

    2017-03-01

    Understanding how species respond to the environment in terms of population attributes (e.g. abundance, growth, mortality, fecundity, and productivity) is essential to protect ecologically and economically important species. Nevertheless, responses of macrobenthic populations to environmental features are overlooked due to the need of consecutive samplings and time-consuming measurements. We examined the population dynamics of the filter-feeding bivalve Anomalocardia brasiliana on a tidal flat over the course of one year to investigate the hypothesis that, as accepted for macrobenthic communities, populations inhabiting environments with low hydrodynamic conditions such as tidal flat should have higher attributes than populations inhabiting more energetic habitats (i.e. areas more influenced by wave energy such as reflective and intermediate beaches). This would be expected because the harsh conditions of more energetic habitats force organisms to divert more energy towards maintenance, resulting in lower population attributes. We found that A. brasiliana showed moderate growth and secondary production at the study area. Moreover the recruitment period was restricted to a few months. A comparison with previous studies showed that, contrary to expected, A. brasiliana populations from areas with low hydrodynamic conditions have lower abundance, growth, recruitment and turnover rate. It is likely that morphodynamic characteristics recorded in these environments, such as larger periods of air exposure and lower water circulation, may affect food conditions for filter-feeding species and increase competition. In addition, these characteristics may negatively affect macrobenthic species by enhancing eutrophication processes and anoxia. Overall, our results suggest that models accepted and applied at the macrobenthic community level might not be directly extended to A. brasiliana populations.

  3. Extensional Definition of Interdisciplinarity

    Science.gov (United States)

    Szostak, Rick

    2015-01-01

    An extensional definition of interdisciplinarity--that is, a definition that identifies the types of practices that are interdisciplinary--is explained, advocated, and developed. The criteria for identifying appropriate interdisciplinary practices are outlined. Such a definition is useful both for interdisciplinary teachers and researchers who…

  4. Pterocarpans and a novel flavanone from harpalyce brasiliana roots

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    Araujo, Renata M. de; Lima, Mary Anne S.; Silveira, Edilberto R. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica

    2009-07-01

    The novel (-)-7,8,3',4'-trihydroxy-8-(3{sup ,}7{sup -}dimethyl-octa-2{sup ,}6{sup -}dienoyl)-flavanone was isolated from the EtOH extract from the roots of Harpalyce brasiliana (Leguminosae) together with the known pterocarpans (-)-2-geranyl-3-hydroxy-8,9-methylenedioxypterocarpan, harpalicin, medicarpin, maackiain and cabenegrins A-I and A-II. The isolated metabolites were characterized on the basis of spectroscopic data, mainly 1D and 2D NMR. (author)

  5. Preliminary studies of alternative feed additives for broilers: Alternanthera brasiliana extract, propolis extract and linseed oil

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    MW Biavatti

    2003-05-01

    Full Text Available The influence of alternative treatments using fluidextracts of Alternanthera brasiliana, propolis resin and linseed oil on the performance and blood biochemistry of broilers was evaluated. The study was done with five treatments: basal diet (negative control; basal diet + 40 ppm avylamicin and 120 ppm monensin (positive control; basal diet + A. brasiliana extract (180 mL/200 kg of feed; basal diet + propolis extract (200 mL/200 kg of feed and basal diet + linseed oil (2.5% replacing soybean oil. Propolis and A. brasiliana extracts improved broiler performance from 14 to 21 days, whereas linseed oil had no effect. The findings of this experiment revealed that A. brasiliana and propolis extracts can be used as antimicrobials, but further studies are necessary to find the best concentration in broiler diets.

  6. Pressure Effect on Extensional Viscosity

    DEFF Research Database (Denmark)

    Christensen, Jens Horslund; Kjær, Erik Michael

    1999-01-01

    The primary object of these experiments was to investigate the influence of hydrostatic pressure on entrance flow. The effect of pressure on shear and extensional viscosity was evaluated using an axis symmetric capillary and a slit die where the hydrostatic pressure was raised with valves....... The experiments show a significant increase in extensional viscosity with increasing pressure....

  7. Chemical constituents from three medicinal plants: Piper renitens, Siparuna guianensis and Alternanthera brasiliana

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    Valdir A. Facundo

    2012-04-01

    Full Text Available Chemical study of three medicinal plants: from leaves of Piper renitens (Miq. Yunck, Piperaceae, and Siparuna guianensis Aubl., Siparunaceae, and from flowers of Alternanthera brasiliana (L. Kuntze, Amaranthaceae, resulted in isolation of nine compounds: three steroids, β-sitosterol, stigmasterol from P. renitens and sitosterol-3-O-β-D-glucopyranoside from A. brasiliana, the diterpene kaurane ent-kauran-16α,17-diol from P. renitens, two derivatives kaempferol-methylether, kumatakenine (kaempferol-3,7-dimethylether and kaempferol-3,7,3'-trimethylether from S. guianensis and three flavones, crysoeriol (5,7,4'-trihydroxy-3'-methoxyflavone, tricin (5,7,4'-trihydroxy-3',5'-dimethoxyflavone and 7-O-β-D-glucopyranoside-5,4'-dihydroxy-3'-methoxyflavone from A. brasiliana. Compounds structures were determinate using 1D and 2D ¹H NMR and 13C spectral data, mass and IR spectra, comparing with literature data.

  8. Chemical constituents from three medicinal plants: Piper renitens, Siparuna guianensis and Alternanthera brasiliana

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    Valdir A. Facundo

    2012-10-01

    Full Text Available Chemical study of three medicinal plants: from leaves of Piper renitens (Miq. Yunck, Piperaceae, and Siparuna guianensis Aubl., Siparunaceae, and from flowers of Alternanthera brasiliana (L. Kuntze, Amaranthaceae, resulted in isolation of nine compounds: three steroids, β-sitosterol, stigmasterol from P. renitens and sitosterol-3-O-β-D-glucopyranoside from A. brasiliana, the diterpene kaurane ent-kauran-16α,17-diol from P. renitens, two derivatives kaempferol-methylether, kumatakenine (kaempferol-3,7-dimethylether and kaempferol-3,7,3'-trimethylether from S. guianensis and three flavones, crysoeriol (5,7,4'-trihydroxy-3'-methoxyflavone, tricin (5,7,4'-trihydroxy-3',5'-dimethoxyflavone and 7-O-β-D-glucopyranoside-5,4'-dihydroxy-3'-methoxyflavone from A. brasiliana. Compounds structures were determinate using 1D and 2D ¹H NMR and 13C spectral data, mass and IR spectra, comparing with literature data.

  9. Processamento, estabilidade e aceitabilidade de marinado de vongole (Anomalocardia brasiliana Processing, stability and acceptability of marinade of vongole (Anomalocardia brasiliana

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    Eliete da Silva Bispo

    2004-09-01

    Full Text Available O vongole (Anomalocardia brasiliana tem importância socioeconômica para grande parte da população da região da Baía de Todos os Santos, na costa da Bahia, por fazer parte da dieta familiar e ser uma das principais fontes de renda. Para ampliar a comercialização deste molusco foi desenvolvido um processo de obtenção de marinado, envolvendo acidificação do produto com vinagre (pHThe vongole has economic-social importance to the most of people in the "Todos os Santos" Bay, located in Bahia coast, Brazil; it is a product of the familiar diet and it is one of the principal rental source of this local people. In purpose to increase the mollusc sale was developed studies on the marinating of vongole, through acidification of the product with vinegar at a pH[4,5 and a boiling water treatment during 30 min.The product was stored at room temperature for 240 days and the shelf life study included microbiological, physico-chemical, chemical and sensory evaluation. The process was effective to stablish commercial sterility to the marinaded vongole. According to sensory analyses, the marinaded vongole reached acceptability index like 78-82% for the overall appearance, colour, odour, flavour and texture. The data showed that the marinade of vongole was stable during storage for 240 days at room temperature.

  10. Polymer fragmentation in extensional flow

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    Maroja, Armando M.; Oliveira, Fernando A.; Ciesla, Michal; Longa, Lech

    2001-06-01

    In this paper we present an analysis of fragmentation of dilute polymer solutions in extensional flow. The transition rate is investigated both from theoretical and computational approaches, where the existence of a Gaussian distribution for the breaking bonds has been controversial. We give as well an explanation for the low fragmentation frequency found in DNA experiments.

  11. Presence of enteric viruses, bioaccumulation and stability in Anomalocardia brasiliana clams (Gmelin, 1791).

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    Souza, Doris Sobral Marques; Dominot, Ana Ferreira Ávila; Moresco, Vanessa; Barardi, Célia Regina Monte

    2018-02-02

    Bivalve mollusks are filter feeders and may accumulate human pathogens in their tissues. Many studies demonstrated human diseases associated with bivalve consumption, especially oysters. Anomalocardia brasiliana clams are distributed along the Brazilian coastal area and are an exotic ingredient for some typical dishes in Brazil. Even though there are several reports describing the contamination of oysters and mussels with human pathogens, there is a lack of studies reporting contamination of A. brasiliana with human pathogens. An evaluation of natural microbiological contamination in A. brasiliana samples over a period of 18months (November 2014 to April 2016) showed that the bacteria indices were in accordance with Brazilian regulations (E. coli<230MPN and Salmonella sp. absent in 25g of meat). However, the enteric viruses evaluated were detected throughout the analysis period, with the highest result for the hepatitis A virus (HAV); followed by Rotavirus-A (RVA); Human Adenovirus (HAdV) and Norovirus GI (NoV GI). The bioaccumulation of enteric viruses by A. brasiliana during a period of 24h was performed using NoV GI and GII, HAV, RVA and HAdV as models. Interestingly the mollusk demonstrated different uptake behaviors in relation to these viruses throughout the time period. NoV GI was the most adsorbed virus after 24h. HAV concentration was <1% at 3h, but it increased to <10% at 8h, remaining unchanged until 12h, and decreasing to <3% at 24h; HAdV reached its highest concentration at 12h, being released by the animals and lowering to <3% at 24h. RVA bioaccumulation was unstable over time, reaching its highest values after 24h (<5%); NoV GII bioaccumulation remained <1%. Thermal inactivation of HAdV-2 in A. brasiliana was also evaluated. After the usual gentle cooking procedure using different times (0, 1, 1.5, 3 and 5mins), viral infectivity was evaluated using ICC-et-RT-qPCR. The temperature inside the DT remained <80°C over time and after 5min of cooking the

  12. Geometry and kinematics of extensional structural wedges

    Science.gov (United States)

    Gui, Baoling; He, Dengfa; Zhang, Yongsheng; Sun, Yanpeng; Huang, Jingyi; Zhang, Wenjun

    2017-03-01

    Structural wedges in the compressive environment have been recognized and studied in different locations. However, extension structural wedges are less well-understood. Based on the normal fault-bend folding theory and inclined shear model, this paper quantitatively analyses deformations related to extensional structural wedges and builds a series of geometric models for them. An extensional structural wedge is a fault-block held by two or more normal faults, the action of which would fold its overlying strata. Extensional structural wedges of different shapes will lead to different deformation results for the overlying strata, and this paper illustrates both the triangular and quadrangular wedges and their related deformations. This paper also discusses differences between the extensional structural wedges and the normal fault-bend-folding. By analysing two seismic sections from Langfang-Gu'an Sag, East China, this paper provides two natural examples of the triangular and quadrangular extensional structural wedges, where the models can reasonably explain the overlying distinct highs and lows without obvious faults. The establishment of a geometric model of extensional structural wedges can provide reference and theoretical bases for future quantitative analysis of deformations in the extensional environment.

  13. Microfluidic extensional rheometry using stagnation point flow.

    Science.gov (United States)

    Haward, S J

    2016-07-01

    Characterization of the extensional rheometry of fluids with complex microstructures is of great relevance to the optimization of a wide range of industrial applications and for understanding various natural processes, biological functions, and diseases. However, quantitative measurement of the extensional properties of complex fluids has proven elusive to researchers, particularly in the case of low viscosity, weakly elastic fluids. For some time, microfluidic platforms have been recognized as having the potential to fill this gap and various approaches have been proposed. This review begins with a general discussion of extensional viscosity and the requirements of an extensional rheometer, before various types of extensional rheometers (particularly those of microfluidic design) are critically discussed. A specific focus is placed on microfluidic stagnation point extensional flows generated by cross-slot type devices, for which some important developments have been reported during the last 10 years. Additional emphasis is placed on measurements made on relevant biological fluids. Finally, the operating limits of the cross-slot extensional rheometer (chiefly imposed by the onset of elastic and inertial flow instabilities) are discussed.

  14. Extensional Information Articulation from the Universe

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    Yasufumi Saruwatari

    2012-11-01

    Full Text Available Information must have physical support and this physical universe comprisesphysical interactions. Hence actual information processes should have a description byinteractions alone, i.e., an extensional description. In this paper, such a model of the processof information articulation from the universe is developed by generalizing the extensivemeasurement theory in metrology. Moreover, a model of the attribute creation processis presented to exemplify a step of the informational articulation process. These modelsdemonstrate the valuableness of the extensional view and are expected to enhance theunderstanding of the extensional aspects of fundamentals of information.

  15. Extensional scientific realism vs. intensional scientific realism.

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    Park, Seungbae

    2016-10-01

    Extensional scientific realism is the view that each believable scientific theory is supported by the unique first-order evidence for it and that if we want to believe that it is true, we should rely on its unique first-order evidence. In contrast, intensional scientific realism is the view that all believable scientific theories have a common feature and that we should rely on it to determine whether a theory is believable or not. Fitzpatrick argues that extensional realism is immune, while intensional realism is not, to the pessimistic induction. I reply that if extensional realism overcomes the pessimistic induction at all, that is because it implicitly relies on the theoretical resource of intensional realism. I also argue that extensional realism, by nature, cannot embed a criterion for distinguishing between believable and unbelievable theories. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Extensional rheometer based on viscoelastic catastrophes outline

    DEFF Research Database (Denmark)

    2014-01-01

    The present invention relates to a method and a device for determining viscoelastic properties of a fluid. The invention resides inter alia in the generation of viscoelastic catastrophes in confined systems for use in the context of extensional rheology. The viscoelastic catastrophe is according...... to the invention generated in a bistable fluid system, and the flow conditions for which the catastrophe occurs can be used as a fingerprint of the fluid's viscoelastic properties in extensional flow....

  17. Population structure of the bivalve Anomalocardia brasiliana, (Gmelin, 1791 in the semi-arid estuarine region of northeastern Brazil

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    AML Rodrigues

    Full Text Available For several decades, the bivalve mollusk Anomalocardia brasiliana has been extracted in estuarine areas in the semi-arid region of northeastern Brazil. However, information on both dynamics and abundance of their populations are missing. In this context, the present study, therefore, investigated several aspects of the population structure of A. brasiliana on beaches near the estuary of the Apodi River in Northeast Brazil. The aims were to determine the population density of A. brasiliana during different times of the year, to estimate population parameters, and to relate species density and distribution to the abiotic characteristics of the region. Sampling was performed from March/2007 and May/2008, we collected samples of sediments and mollusks along 180 m transects in the intertidal area on the beaches Barra and Pernambuquinho, Grossos - RN. At each sampling site, samples of sediments and mollusks were collected in the intertidal area along 180 m transects. The highest and lowest average densities on Pernambuquinho beach were 1148 (April/2007, and 100 individuals.m–2 (May/ 2008, respectively. On Barra beach, the highest and lowest densities were 1813 (April/2007 and 951 individuals.m–2, (November/2007, respectively. The densities of A. brasiliana on both beaches were significantly different only in the months of January, April and May/ 2008. Length of the individuals ranged from 1 to 28 mm, with most individuals measuring between 22 and 24 mm. Length growth rate parameters for A. brasiliana were L∞ = 28.68 mm and k = 0.61 year–1 on Barra beach, and L∞ = 29.87 mm and k = 0.48 year–1 on Pernambuquinho beach. The growth rate curves for A. brasiliana suggest the presence of three well defined cohorts, thus pointing to a continuous reproduction cycle with peak recruitment between October/2007 and March/2008. A. brasiliana density decreased predominantly during the heavy rains of 2008, probably due to an accumulation of sediments and

  18. Transcriptional changes in oysters Crassostrea brasiliana exposed to phenanthrene at different salinities

    Energy Technology Data Exchange (ETDEWEB)

    Zacchi, Flávia Lucena; Lima, Daína; Flores-Nunes, Fabrício de [Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry − LABCAI, Federal University Santa Catarina, Florianópolis (Brazil); Mattos, Jacó Joaquim [Aquaculture Pathology Research Center – NEPAQ, Federal University of Santa Catarina, Florianópolis (Brazil); Lüchmann, Karim Hahn [Laboratory of Biochemistry and Molecular Biology – LBBM, Fishery Engineering Department, Santa Catarina State University, Laguna (Brazil); Araújo de Miranda Gomes, Carlos Henrique [Laboratory of Marine Mollusks – LMM, Federal University of Santa Catarina, Florianópolis (Brazil); Bícego, Márcia Caruso; Taniguchi, Satie; Sasaki, Silvio Tarou [Laboratory of Marine Organic Chemistry – LABQOM, Oceanographic Institute, University of São Paulo, São Paulo (Brazil); Dias Bainy, Afonso Celso, E-mail: afonso.bainy@ufsc.br [Laboratory of Biomarkers of Aquatic Contamination and Immunochemistry − LABCAI, Federal University Santa Catarina, Florianópolis (Brazil)

    2017-02-15

    Highlights: • Salinity effect on Crassostrea brasiliana exposed to phenanthrene. • Higher transcription of biotransformation genes under hyposmotic condition. • Elevated transcription of oxidative stress-related genes under hyposmotic condition. • Amino acid metabolism-related genes changes according to salinity. • Phenanthrene does not affect amino acid metabolism-related genes. - Abstract: Euryhaline animals from estuaries, such as the oyster Crassostrea brasiliana, show physiological mechanisms of adaptation to tolerate salinity changes. These ecosystems receive constant input of xenobiotics from urban areas, including polycyclic aromatic hydrocarbons (PAHs), such as phenanthrene (PHE). In order to understand the influence of salinity on the molecular responses of C. brasiliana exposed to PHE, oysters were acclimatized to different salinities (35, 25 and 10) for 15 days and then exposed to 100 μg L{sup −1} PHE for 24 h and 96 h. Control groups were kept at the same salinities without PHE. Oysters were sampled for chemical analysis and the gills were excised for mRNA quantification by qPCR. Transcript levels of different genes were measured, including some involved in oxidative stress pathways, phases I and II of the xenobiotic biotransformation systems, amino acid metabolism, fatty acid metabolism and aryl hydrocarbon receptor nuclear translocator putative gene. Higher transcript levels of Sulfotransferase-like gene (SULT-like) were observed in oysters exposed to PHE at salinity 10 compared to control (24 h and 96 h); cytochrome P450 isoforms (CYP2AU1, CYP2-like1) were more elevated in oysters exposed for 24 h and CYP2-like2 after 96 h of oysters exposed to PHE at salinity 10 compared to control. These results are probably associated to an enhanced Phase I biotransformation activity required for PHE detoxification under hyposmotic stress. Higher transcript levels of CAT-like, SOD-like, GSTm-like (96 h) and GSTΩ-like (24 h) in oysters kept at

  19. Analysis of transcriptional responses of normalizing genes on Crassostrea brasiliana under different experimental conditions.

    Science.gov (United States)

    Müller, Gabrielle do Amaral E Silva; de Lima, Daína; Zacchi, Flávia Lucena; Piazza, Rômi Sharon; Lüchmann, Karim Hahn; Mattos, Jacó Joaquim; Schlenk, Daniel; Bainy, Afonso Celso Dias

    2017-08-01

    Bivalves show remarkable plasticity to environmental changes and have been proposed as sentinel organisms in biomonitoring. Studies related to transcriptional analysis using quantitative real-time polymerase chain reaction (qRT-PCR) in these organisms have notably increased, imposing a need to identify and validate adequate reference genes for an accurate and reliable analysis. In the present study, 9 reference genes were selected from transcriptome data of Crassostrea brasiliana to identify their suitability as qRT-PCR normalizer genes. The transcriptional patterns were analyzed in gills of oysters under 3 different conditions: different temperatures (18, 24, or 32 °C) and phenanthrene (100 µg L(-1) ) combined exposure; different salinities (10, 25, or 35‰) and phenanthrene combined exposure; and 10% of diesel fuel water-accommodated fraction (diesel-WAF) exposure. Reference gene stability was calculated using 5 algorithms (geNorm, NormFinder, BestKeeper, ΔCt, RefFinder). Transcripts of ankyrin-like (ANK), glyceraldehyde 3-phosphate dehydrogenase-like (GAPDH), and α-tubulin-like (TUBA) genes showed minor changes in different temperature/phenanthrene treatment. Transcripts of ANK, β-actin-like, and β-tubulin-like genes showed better stability at salinity/phenanthrene treatment, and ANK, TUBA, and 28S ribosomal protein-like genes showed the most stable transcription pattern in oysters exposed to diesel-WAF exposure. The present study constitutes the first systematic analysis of reference gene selection for qRT-PCR normalization in C. brasiliana. These genes could be employed in studies using qRT-PCR analysis under similar experimental conditions. Environ Toxicol Chem 2017;36:2190-2198. © 2017 SETAC. © 2017 SETAC.

  20. Inside-out flowers of Lacandonia brasiliana (Triuridaceae) provide new insights into fundamental aspects of floral patterning.

    Science.gov (United States)

    Rudall, Paula J; Alves, Marccus; Sajo, Maria das Graças

    2016-01-01

    Background and Aims. A recently described Brazilian species, Lacandonia brasiliana, shares with its longer established putative sister species from Mexico, L. schismatica, inverted floral patterning (carpels surrounding stamens) that is almost unique among angiosperms. We present a detailed ontogenetic study of L. brasiliana for comparison with other members of the tribe Triurideae (Triuridaceae) to explore the possible evolutionary origins of "inside-out" flowers. Methods. Wild-source populations of L. brasiliana were compared morphologically and ontogenetically with related species of Triurideae, using light and scanning electron microscopy. Key Results. Relatively few morphological differences separate flowers of L. brasiliana and L. schismatica. Both species have tepals with late-developing subapical appendages. In both species, the three central (almost sessile) anthers develop precociously with respect to the carpels; the anthers remain closed, and fertilization is achieved via pollen-tube growth from germinating pollen grains of the same cleistogamous flower. Carpels are initiated on fascicles. Conclusions. The close similarity between the two Lacandonia species makes it unlikely that they arose independently from two separate homeotic transformation events; they could either represent sister species or two populations of a single disjunct species. Our study underlines the problematic generic and species boundaries within Triurideae. We present an evolutionary scenario of character evolution in Triuridaceae. The inside-out Lacandonia flower could have resulted from a stabilized homeotic transformation; this hypothesis is not in conflict with constrasting theories of the origin of the Triuridaceae flower, which coincided with a shift to unisexuality. The unisexual yet highly plastic flowers that are typical of Triuridaceae could have pre-adapted the origin of the extraordinary Lacandonia morphology.

  1. Inside-out flowers of Lacandonia brasiliana (Triuridaceae provide new insights into fundamental aspects of floral patterning

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    Paula J. Rudall

    2016-02-01

    Full Text Available Background and Aims. A recently described Brazilian species, Lacandonia brasiliana, shares with its longer established putative sister species from Mexico, L. schismatica, inverted floral patterning (carpels surrounding stamens that is almost unique among angiosperms. We present a detailed ontogenetic study of L. brasiliana for comparison with other members of the tribe Triurideae (Triuridaceae to explore the possible evolutionary origins of “inside-out” flowers. Methods. Wild-source populations of L. brasiliana were compared morphologically and ontogenetically with related species of Triurideae, using light and scanning electron microscopy. Key Results. Relatively few morphological differences separate flowers of L. brasiliana and L. schismatica. Both species have tepals with late-developing subapical appendages. In both species, the three central (almost sessile anthers develop precociously with respect to the carpels; the anthers remain closed, and fertilization is achieved via pollen-tube growth from germinating pollen grains of the same cleistogamous flower. Carpels are initiated on fascicles. Conclusions. The close similarity between the two Lacandonia species makes it unlikely that they arose independently from two separate homeotic transformation events; they could either represent sister species or two populations of a single disjunct species. Our study underlines the problematic generic and species boundaries within Triurideae. We present an evolutionary scenario of character evolution in Triuridaceae. The inside-out Lacandonia flower could have resulted from a stabilized homeotic transformation; this hypothesis is not in conflict with constrasting theories of the origin of the Triuridaceae flower, which coincided with a shift to unisexuality. The unisexual yet highly plastic flowers that are typical of Triuridaceae could have pre-adapted the origin of the extraordinary Lacandonia morphology.

  2. Significant genetic differentiation among populations of Anomalocardia brasiliana (Gmelin, 1791: a bivalve with planktonic larval dispersion

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    Cinthya Cristina Bulhões Arruda

    2009-01-01

    Full Text Available Four Brazilian populations of Anomalocardia brasiliana were tested for mutual genetic homogeneity, using data from 123 sequences of the mtDNA cytochrome oxidase c subunit I gene. A total of 36 haplotypes were identified, those shared being H3 (Canela Island, Prainha and Acupe and both H5 and H9 (Prainha and Acupe. Haplotype diversity values were high, except for the Camurupim population, whereas nucleotide values were low in all the populations, except for that of Acupe. Only the Prainha population showed a deviation from neutrality and the SSD test did not reject the demographic expansion hypothesis. Fst values showed that the Prainha and Acupe populations represent a single stock, whereas in both the Canela Island and Camurupim stocks, population structures are different and independent. The observed structure at Canela Island may be due to the geographic distance between this population and the remainder. The Camurupim population does not share any haplotype with the remaining populations in northeastern Brazil. The apparent isolation could be due to the rocky barrier located facing the mouth of the Mamanguape River. The results highlight the importance of wide-scale studies to identify and conserve local genetic diversity, especially where migration is restricted.

  3. Significant genetic differentiation among populations of Anomalocardia brasiliana (Gmelin, 1791): A bivalve with planktonic larval dispersion

    Science.gov (United States)

    2009-01-01

    Four Brazilian populations of Anomalocardia brasiliana were tested for mutual genetic homogeneity, using data from 123 sequences of the mtDNA cytochrome oxidase c subunit I gene. A total of 36 haplotypes were identified, those shared being H3 (Canela Island, Prainha and Acupe) and both H5 and H9 (Prainha and Acupe). Haplotype diversity values were high, except for the Camurupim population, whereas nucleotide values were low in all the populations, except for that of Acupe. Only the Prainha population showed a deviation from neutrality and the SSD test did not reject the demographic expansion hypothesis. Fst values showed that the Prainha and Acupe populations represent a single stock, whereas in both the Canela Island and Camurupim stocks, population structures are different and independent. The observed structure at Canela Island may be due to the geographic distance between this population and the remainder. The Camurupim population does not share any haplotype with the remaining populations in northeastern Brazil. The apparent isolation could be due to the rocky barrier located facing the mouth of the Mamanguape River. The results highlight the importance of wide-scale studies to identify and conserve local genetic diversity, especially where migration is restricted. PMID:21637701

  4. Changes in the microbiological quality of mangrove oysters (Crassostrea brasiliana) during different storage conditions.

    Science.gov (United States)

    Montanhini, Maike Taís Maziero; Montanhini Neto, Roberto

    2015-01-01

    This study aimed to determine the effect of temperature and period of postharvest storage on the microbiological quality and shelf life of raw mangrove oysters, Crassostrea brasiliana. A total of 150 dozen oysters were collected directly from the points of extraction or cultivation in southern Brazil, and in the laboratory, they were stored raw at 5, 10, 15, 20, and 25°C for 1, 4, 8, 11, and 15 days. On each of these days, the oysters were subjected to microbiological analyses of aerobic mesophilic count, total coliforms, enterococci, Escherichia coli, Staphylococcus aureus, and Salmonella. None of the tested samples under any storage condition showed contamination levels above those allowed by Brazilian legislation for E. coli, S. aureus, and Salmonella, and there was no change (P > 0.05) in the counts of these microorganisms due to the temperature and/or period of oyster storage. Counts of enterococci and total coliforms showed a tendency to increase (P < 0.05) among the different temperatures tested. Raw mangrove oysters remain in safe microbiological conditions for consumption up to 8 days after harvesting, regardless of temperature, and their shelf life may be extended to 15 days if they are stored at temperatures not exceeding 15°C.

  5. An Extensional CPS Transform (Preliminary Report)

    DEFF Research Database (Denmark)

    Filinski, Andrzej

    2001-01-01

    We shoe that, in a language wihg general continuation-effects, the syntactic, or intensional, CPS transform is mirrored by a semantic, or extensional, functional term. In other words, form only the observable behavior any direct-style term (possibly containing the usual first-class continuation...... primitives), we can uniformly extract the observable behavior of its CPS counterpart. As a consequence of this result, we show that the computational lambda-calculus is complete for observational equivalence of pure, simply typed lambda-terms in Scheme-like contexts....

  6. Hyperbolic contraction measuring systems for extensional flow

    Science.gov (United States)

    Nyström, M.; Tamaddon Jahromi, H. R.; Stading, M.; Webster, M. F.

    2017-08-01

    In this paper an experimental method for extensional measurements on medium viscosity fluids in contraction flow is evaluated through numerical simulations and experimental measurements. This measuring technique measures the pressure drop over a hyperbolic contraction, caused by fluid extension and fluid shear, where the extensional component is assumed to dominate. The present evaluative work advances our previous studies on this experimental method by introducing several contraction ratios and addressing different constitutive models of varying shear and extensional response. The constitutive models included are those of the constant viscosity Oldroyd-B and FENE-CR models, and the shear-thinning LPTT model. Examining the results, the impact of shear and first normal stress difference on the measured pressure drop are studied through numerical pressure drop predictions. In addition, stream function patterns are investigated to detect vortex development and influence of contraction ratio. The numerical predictions are further related to experimental measurements for the flow through a 15:1 contraction ratio with three different test fluids. The measured pressure drops are observed to exhibit the same trends as predicted in the numerical simulations, offering close correlation and tight predictive windows for experimental data capture. This result has demonstrated that the hyperbolic contraction flow is well able to detect such elastic fluid properties and that this is matched by numerical predictions in evaluation of their flow response. The hyperbolical contraction flow technique is commended for its distinct benefits: it is straightforward and simple to perform, the Hencky strain can be set by changing contraction ratio, non-homogeneous fluids can be tested, and one can directly determine the degree of elastic fluid behaviour. Based on matching of viscometric extensional viscosity response for FENE-CR and LPTT models, a decline is predicted in pressure drop for

  7. Extensional rheometry with a handheld mobile device

    Science.gov (United States)

    Marshall, Kristin A.; Liedtke, Aleesha M.; Todt, Anika H.; Walker, Travis W.

    2017-06-01

    The on-site characterization of complex fluids is important for a number of academic and industrial applications. Consequently, a need exists to develop portable rheometers that can provide in the field diagnostics and serve as tools for rapid quality assurance. With the advancement of smartphone technology and the widespread global ownership of smart devices, mobile applications are attractive as platforms for rheological characterization. The present work investigates the use of a smartphone device for the extensional characterization of a series of Boger fluids composed of glycerol/water and poly(ethylene oxide), taking advantage of the increasing high-speed video capabilities (currently up to 240 Hz capture rate at 720p) of smartphone cameras. We report a noticeable difference in the characterization of samples with slight variations in polymer concentration and discuss current device limitations. Potential benefits of a handheld extensional rheometer include its use as a point-of-care diagnostic tool, especially in developing communities, as well as a simple and inexpensive tool for assessing product quality in industry.

  8. In vitro anthelmintic activity and chemical composition of methanol extracts and fractions of Croton paraguayensis and Vernonia brasiliana against Eisenia fetida

    Directory of Open Access Journals (Sweden)

    Andrea Leticia Cáceres

    2017-02-01

    Full Text Available Objective: To evaluate the chemical composition and the anthelmintic activity of the methanol extracts and the acid and basic fractions of Croton paraguayensis (C. paraguayensis and Vernonia brasiliana (V. brasiliana against Eisenia fetida. Methods: A preliminary phytochemical analysis was performed to assess the presence of groups of secondary metabolites. The plants were extracted with methanol to obtain the crude extracts. A differential pH extraction was performed to isolate basic compounds like alkaloids. The methanolic extracts and the fractions obtained were tested for anthelmintic activity against Eisenia fetida, using albendazole as positive control. Results: The phytochemical test demonstrated the presence of alkaloids in the crude extracts and alkaline fractions, along with flavonoids, coumarins, steroids/triterpenes and tannins. The anthelmintic activity of the extracts and fractions of C. paraguayensis and V. brasiliana showed a statistically significant decrease of the times for paralysis and death compared to albendazole. Conclusions: The methanolic extracts and fractions of C. paraguayensis and V. brasiliana contain compounds that possess anthelmintic activity. The isolation of the substances responsible for the biological effect described could result in the development of new drugs to treat helminth diseases.

  9. Human capability in the perception of extensional and shear viscosity.

    Science.gov (United States)

    Lv, Zhihong; Chen, Jianshe; Holmes, Melvin

    2017-10-01

    Shear and extensional deformation are two basic rheological phenomena which occur commonly in our daily life. Because of the very different nature of the two deformations, fluid materials may exhibit significant differences in their responses to shear and extensional forces. This work investigated the human perception of shear and extensional viscosity and tested the hypothesis that human have different discriminatory sensation mechanisms including scaling to the two deformations. A series of fluid samples were prepared using two common food thickeners, guar gum and sodium carboxylmethylcellulose (CMC-Na). The shear and extensional flow behavior of these fluids were assessed using shear and extensional rheometers and in addition two separate sensory analysis sessions were organized to assess human sensitivity in perceiving the two viscosities. Magnitude estimation was used in the first session to assess human sensitivity in the perception of the shear and extensional viscosities and just-noticeable-difference (JND) assessment was used for the second session to identify the typical threshold of viscosity discrimination. For the participants considered, it was found that the perception of both shear and extensional viscosity follow a power law relationship i.e. Steven's law. It was also observed that the human has a greater discriminatory capacity in perceiving extensional viscosity. JND analysis showed that the human threshold in detecting shear viscosity difference was 9.33%, but only 6.20% for extensional viscosity. Shear and extensional deformation are two basic rheological properties which occur during food manipulation, mastication, deglutition executed during oral consumption and also in the processing and packaging of foods. Fluid resistance against shear and extensional deformation differ widely and whilst this has been confirmed theoretically and experimentally, a clear understanding of human perception of these properties will have beneficial returns to

  10. 3D modeling of dual wind-up extensional rheometers

    DEFF Research Database (Denmark)

    Yu, Kaijia; Román Marín, José Manuel; Rasmussen, Henrik K.

    2010-01-01

    Fully three-dimensional numerical simulations of a dual wind-up drum rheometer of the Sentmanat Extensional Rheometer (SER; Sentmanat, 2004 [1]) or the Extensional Viscosity Fixture (EVF; Garritano and Berting, 2006 [2]) type have been performed. In the SER and EVF a strip of rectangular shape...

  11. Extensional Rheology of Fire Ant Aggregates

    Science.gov (United States)

    Franklin, Scott; Kern, Matthew; Phonekeo, Sulisay; Hu, David

    We explore the extensional rheology and self-healing of fire ant (Solenopsis invicta) aggregations, mechanically entangled ensembles used to form rafts, bivouacs or bridges. Macroscopic experiments create quasi-two dimensional piles and measure the force required to impose a constant end-velocity. This force fluctuates, reminiscent of similar experiments on geometrically cohesive granular materials. Heterogeneous chains develop, with isolated ants often the sole link between top and bottom. Finally, the maximum pile strength scales sub-linearly with the number of ants, with the maximum force per ant decreasing as the pile grows. We reproduce these behaviors with a simple model that represents ants feet as discs connected by a spring (the ''leg''). Discs move randomly, and stick to one another when in contact. Discs in contact un-stick at random with a probability that decreases as the spring (leg) is stretched, modeling an ant's tendency to hold on longer when stretched. Simulations qualitatively reproduces the fluctuating force, chain formation and sublinear scaling of maximum force with particle number and give insight into underlying mechanisms that govern the ants' behaviors. Funded in part by NSF DMR #1133722.

  12. Modeling of dual cylinder wind-up extensional rheometers

    DEFF Research Database (Denmark)

    Yu, Kaijia; Marin, Jose; Jensen, Mette

    Polymer extensional flow is the one of the most important deformation in polymer processing. It is the dominant deformation in melt-spinning, bottle-blowing, and roll-coating. Because the molecular structure of the polymeric system strongly influences the extension viscosity, extensional flow......). *The title of this submission has been modified to remove the name of a commercial product or company to bring the title into compliance with SOR policy....

  13. Grabens on Io: Evidence for Extensional Tectonics

    Science.gov (United States)

    Hoogenboom, T.; Schenk, P.

    2012-12-01

    Io may well be the most geologically active body in the solar system. A variety of volcanic features have been identified, including a few fissure eruptions, but tectonism is generally assumed to be limited to compression driven mountain formation (Schenk et al., 2001). A wide range of structural features can also be identified including scarps, lineaments, faults, and circular depressions (pits and patera rims). Narrow curvilinear graben (elongated, relatively depressed crustal unit or block that is bounded by faults on its sides) are also scattered across Io's volcanic plains. These features are dwarfed by the more prominent neighboring volcanoes and mountains, and have been largely ignored in the literature. Although they are likely to be extensional in origin, their relationship to local or global stress fields is unknown. We have mapped the locations, length and width of graben on Io using all available Voyager and Galileo images with a resolution better than 5 km. We compare the locations of graben with existing volcanic centers, paterae and mountain data to determine the degree of correlation between these geologic features and major topographic variations (basins/swells) in our global topographic map of Io (White et al., 2011). Graben are best observed in > 1-2 km low-sun angle images. Approximately 300 images were converted from ISIS to ArcMap format to allow easy comparison with the geological map of Io (Williams et al., 2012) along with previous higher resolution structural mapping of local areas (e.g. Crown et al., 1992). We have located >45 graben to date. Typically 1-3 kilometers across, some of these features can stretch for over 500 kilometers in length. Their formation may be related to global tidal stresses or local deformation. Io's orbit is eccentric and its solid surface experiences daily tides of up to ˜0.1 km, leading to repetitive surface strains of 10-4 or greater. These tides flex and stress the lithosphere and can cause it to fracture

  14. Passive non-linear microrheology for determining extensional viscosity

    Science.gov (United States)

    Hsiao, Kai-Wen; Dinic, Jelena; Ren, Yi; Sharma, Vivek; Schroeder, Charles M.

    2017-12-01

    Extensional viscosity is a key property of complex fluids that greatly influences the non-equilibrium behavior and processing of polymer solutions, melts, and colloidal suspensions. In this work, we use microfluidics to determine steady extensional viscosity for polymer solutions by directly observing particle migration in planar extensional flow. Tracer particles are suspended in semi-dilute solutions of DNA and polyethylene oxide, and a Stokes trap is used to confine single particles in extensional flows of polymer solutions in a cross-slot device. Particles are observed to migrate in the direction transverse to flow due to normal stresses, and particle migration is tracked and quantified using a piezo-nanopositioning stage during the microfluidic flow experiment. Particle migration trajectories are then analyzed using a second-order fluid model that accurately predicts that migration arises due to normal stress differences. Using this analytical framework, extensional viscosities can be determined from particle migration experiments, and the results are in reasonable agreement with bulk rheological measurements of extensional viscosity based on a dripping-onto-substrate method. Overall, this work demonstrates that non-equilibrium properties of complex fluids can be determined by passive yet non-linear microrheology.

  15. Hermaphroditism among dioecious Tagelus plebeius (Lightfoot, 1786) (Mollusca, Psammobiidae) and Iphigenia brasiliana (Lamarck, 1818) (Mollusca, Donacidae) on the Cachoeira River estuary, Ilhéus, Bahia, Brazil.

    Science.gov (United States)

    Ceuta, L O; Boehs, G; Santos, J J B

    2010-02-01

    The samples of Tagelus plebeius and Iphigenia brasiliana were manually collected on the Cachoeira River estuary region (Ilhéus, BA, Brazil) between August 2005 and August 2006, with a periodicity of 15 days, with 20 animals collected/sampled, performing 500 samples from each species. The animals were measured, eviscerated and kept in solution of Davidson and after 24-30 hours, they were transferred to ethanol 70%. The material was processed for routine histology, with paraffin embedding, obtaining 7 microm thick slices, stained with Harris hematoxilin and Eosin (HE). By light microscopy analysis, 2 cases of hermaphroditism (0.4%) in T. plebeius samples and one case (0.2%) in I. brasiliana were registered with predominance of female over male follicles.

  16. A portable and affordable extensional rheometer for field testing

    Science.gov (United States)

    Hallmark, Bart; Bryan, Matthew; Bosson, Ed; Butler, Simon; Hoier, Tom; Magens, Ole; Pistre, Nicolas; Pratt, Lee; Ward, Betsy-Ann; Wibberley, Sam; Wilson, D. Ian

    2016-12-01

    Extensional shear testing is often needed to characterise the behaviour of complex fluids found in industry and nature. Traditional extensional rheometers are typically expensive, fragile and heavy and are only suited to making measurements in a laboratory environment. For some applications, it is necessary to make in situ rheological measurements where, for example, fluid properties change rapidly over time or where laboratory facilities are unavailable. This paper reports the development and validation of an inexpensive, lightweight and robust ‘open source’ extensional rheometer, Seymour II. Validation was carried out experimentally and computationally. Measurements on a Newtonian fluid (492 mPa s Brookfield silicone oil) yielded results of 510  ±  51 mPa s; these are comfortably within the range of  ±10% which other authors have quoted for extensional techniques using laboratory rheometers. Comparison of the observed filament thinning dynamics to those obtained using computational fluid dynamics (CFD) gave good qualitative agreement. Use of Seymour II at the University of Cambridge Botanic Gardens revealed that the mucilage of the ‘crane flower’, Strelitzia reginae, was a viscoelastic fluid whose extensional response could be described by a two-mode Giesekus equation. Engineering drawings and image analysis code for Seymour II are available for download at the project website, www.seymourII.org/.

  17. Developmental effects of additional ultraviolet a radiation, growth regulators and tyrosine in Alternanthera brasiliana (L. Kuntze cultured in vitro

    Directory of Open Access Journals (Sweden)

    Nina Cláudia Barboza Silva

    2005-09-01

    Full Text Available Tissue cultures of Alternanthera brasiliana (L. Kuntze were treated with different growth regulators (Kinetin and 2,4-D, tyrosine and Ultraviolet A radiation (UV-A; 320 - 400 nm to investigate their effects on development and pigment production. Nodal segments of plantlets grown from seeds were inoculated in all tested media and different light conditions. After eight weeks, this material was used to evaluate biomass, chlorophyll and betacyanin production. The Murashige and Skoog (MS + kinetin medium resulted in development of approximately four shoots/explant. This medium plus white light was the best combination for micropropagation with the highest rooting percentage and betacyanin production. Plantlets grown under UV-A illumination reduced biomass accumulation and worse Chlorophyll a / Chlorophyll b ratio. Addition of 2,4-D resulted in inhibition of pigment production and growth of plantlets.Culturas de tecidos de Alternanthera brasiliana (L. Kuntze foram tratadas com diferentes reguladores de crescimento (Cinetina e 2,4-D, tirosina e com ultravioleta longo (UV-A; 320 -400 nm adicional com o intuito de observar seus efeitos no desenvolvimento e produção de pigmentos. Segmentos nodais de plantas crescidas a partir de sementes foram inoculados nos meios de cultura testados e mantidos sob os diferentes tipos de iluminação. Após 8 semanas este material foi utilizado para avaliação da produção de biomassa, clorofilas e betacianinas. O meio de Murashige and Skoog (MS + cinetina proporcionou plântulas com até 4 brotos/explante. Este meio iluminado com luz branca (tipo luz do dia foi a combinação mais adequada para micropropagação, pois apresenta maior porcentagem de enraizamento e maior produção de betacianinas. Plântulas crescidas sob iluminação com ultravioleta adicional tiveram diminuídas tanto a produção de biomassa quanto a relação Clor a/ Clor b. A adição de 2,4-D ao meio de cultura resultou na inibição da produ

  18. Transient Overshoot Extensional Rheology: Experimental and Numerical Comparisons

    DEFF Research Database (Denmark)

    Hoyle, David; Huang, Qian; Auhl, Dietmar

    rheometer (FSR) and the cross-slot extensional rheometer (CSER). The first two are uni-axial stretching rheometers and the third is a planar extensional rheometer. The FSR and CSER are capable of achieving steady state flows, although in different strain-rate regimes. The SER has been a widely adopted tool...... as it conveniently adapts to a standard shear rheometer. However, the SER is only capable of reaching Hencky strains up to 4. We compare this to the transient measurements of the FSR which uses an active feedback system to control sample necking and is capable of Hencky strains of around 7. We then compare...

  19. Simbiontes associados com Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae na Ilha de Santa Catarina e região continental adjacente, Santa Catarina, Brasil Symbionts associated with Anomalocardia brasiliana (Gmelin (Mollusca, Bivalvia, Veneridae on Santa Catarina Island and adjacent continental region, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Guisla Boehs

    2004-12-01

    Full Text Available Berbigões, Anomalocardia brasiliana (Gmelin, 1791, de bancos naturais da Ilha de Santa Catarina e região continental adjacente (SC, Brasil, foram examinados quanto a presença de simbiontes. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia e poliquetos espionídeos (Polychaeta foram observados macroscopicamente. A análise das secções histológicas evidenciou esporocistos de trematódeos (Digenea, um metacestóide (Cestoda e dois ciliados (Ciliophora.Pointed venus, Anomalocardia brasiliana (Gmelin, 1791, from natural beds of Santa Catarina Island and adjacent continental region (SE Brazil were examined in respect of symbiotic associations. Holothuriophilus tomentosus (Ortmann, 1894 (Brachyura, Sphenia antillensis Dall & Simpson, 1901 (Bivalvia, and polychaete worms (Polychaeta were found by macroscopic diagnosis. By analysis of histological sections, it was noted trematode sporocysts (Digenea, a metacestode (Cestoda and two ciliates (Ciliophora.

  20. Hermaphroditism among dioecious Tagelus plebeius (Lightfoot, 1786 (Mollusca, Psammobiidae and Iphigenia brasiliana (Lamarck, 1818 (Mollusca, Donacidae on the Cachoeira River Estuary, Ilhéus, Bahia, Brazil Hermafroditismo nos moluscos dióicos Tagelus plebeius (Lightfoot, 1786 (Mollusca, Psammobiidae e Iphigenia brasiliana (Lamarck, 1818 (Mollusca, Donacidae na região estuarina do Rio Cachoeira, Ilhéus, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    LO. Ceuta

    2010-02-01

    Full Text Available The samples of Tagelus plebeius and Iphigenia brasiliana were manually collected on the Cachoeira River estuary region (Ilhéus, BA, Brazil between August 2005 and August 2006, with a periodicity of 15 days, with 20 animals collected/sampled, performing 500 samples from each species. The animals were measured, eviscerated and kept in solution of Davidson and after 24-30 hours, they were transferred to ethanol 70%. The material was processed for routine histology, with paraffin embedding, obtaining 7 μm thick slices, stained with Harris hematoxilin and Eosin (HE. By light microscopy analysis, 2 cases of hermaphroditism (0.4% in T. plebeius samples and one case (0.2% in I. brasiliana were registered with predominance of female over male follicles.Os exemplares de Tagelus plebeius e Iphigenia brasiliana foram manualmente coletados na região estuarina do Rio Cachoeira (Ilhéus, Bahia, entre agosto de 2005 e agosto de 2006, com coleta quinzenal de 20 animais, totalizando 500 exemplares/espécie. Os animais foram mensurados, eviscerados e fixados em solução de Davidson por 24-30 horas e depois transferidos para etanol a 70%. O material foi processado por técnica rotineira de histologia, com inclusão em parafina, obtenção de cortes com 7 μm de espessura e coloração por hematoxilina de Harris e Eosina (HE. A análise em microscopia de luz evidenciou 2 casos de hermafroditismo (0,4% em T. plebeius e um caso (0,2% em I. brasiliana (0,2%, com predominância de folículos femininos sobre os masculinos.

  1. Crystallinity of polyethylene in uni-axial extensional flow

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; van Drongelen, Martin; Mortensen, Kell

    such that crystallization from a stretched state can take place. In this work we explore this feature in the attempt to link the nonlinear extensional rheology to the final morphology. We investigate polyethylenes (PE) of various chain architectures and observe that, even for complex architectures like long chain branched...

  2. Late Proterozoic extensional collapse in the Arabian-Nubian Shield

    NARCIS (Netherlands)

    Blasband, B.B.; White, S.H.; Brooijmans, P.; Boorder, H. de; Visser, W.

    2000-01-01

    A structural and petrological study of the Late Proterozoic rocks in the Wadi Kid area, Sinai, Egypt indicates the presence of an extensional metamorphic core complex in the northern Arabian–Nubian Shield. Gneissic domes throughout the Arabian–Nubian Shield resemble the core complex of the Wadi Kid

  3. Recent advances in extensional rheology: controlled flows and fracture

    DEFF Research Database (Denmark)

    Hassager, Ole; Huang, Qian

    to study the relaxation of stress after cession of flow and the transient extensional creep under conditions of constant stress. Combination of the FSR technique with other methods gives further possibilities. For example high speed imaging may be used to study and analyze crack profiles under filament...

  4. Modifying the pom-pom model for extensional viscosity overshoots

    DEFF Research Database (Denmark)

    Hawke, L. D. G.; Huang, Qian; Hassager, Ole

    2015-01-01

    We have developed a variant of the pom-pom model that qualitatively describes two surprising features recently observed in filament stretching rheometer experiments of uniaxial extensional flow of industrial branched polymer resins: (i) Overshoots of the transient stress during steady flow and (i...

  5. Factors That Influence the Extensional Rheological Property of Saliva

    Science.gov (United States)

    Vijay, Amrita; Inui, Taichi; Dodds, Michael; Proctor, Gordon; Carpenter, Guy

    2015-01-01

    The spinnbarkeit of saliva reflects the ability of saliva to adhere to surfaces within the mouth, thereby serving as a protective role and aiding in lubrication. Therefore, alterations in the extensional rheology of saliva may result in the loss in adhesiveness or the ability to bind onto surfaces. Mucin glycoproteins and their structures are known to be important factors for the extensional rheological properties of saliva. The conformation of mucin depends on factors such as pH and ionic strength. Chewing is one of the main stimuli for salivary secretion but creates significant sheer stress on the salivary film which could influence mouthfeel perceptions. The current study investigates the possible factors which affect the extensional rheological properties of saliva by comparing submandibular/sublingual saliva with different oral stimuli within the same group of subjects. Unstimulated and stimulated saliva (chew, smell and taste) salivas were collected primarily from submandibular/sublingual glands. The saliva samples were measured for Spinnbarkeit followed by the measuring mucin, total protein, total calcium and bicarbonate concentrations. The results indicated correlations between rheological properties and mucin/ion concentrations. However, chewing stimulated submandibular/sublingual saliva is shown to have significantly lower Spinnbarkeit, but factors such as mucin, protein and calcium concentrations did not account for this variation. Analysis of the concentration of bicarbonate and pH appears to suggest that it has a prominent effect on extensional rheology of saliva. PMID:26305698

  6. Naive Probability: A Mental Model Theory of Extensional Reasoning.

    Science.gov (United States)

    Johnson-Laird, P. N.; Legrenzi, Paolo; Girotto, Vittorio; Legrenzi, Maria Sonino; Caverni, Jean-Paul

    1999-01-01

    Outlines a theory of naive probability in which individuals who are unfamiliar with the probability calculus can infer the probabilities of events in an "extensional" way. The theory accommodates reasoning based on numerical premises, and explains how naive reasoners can infer posterior probabilities without relying on Bayes's theorem.…

  7. Late Cenozoic extensional faulting in Central-Western Peloponnesus, Greece

    Science.gov (United States)

    Skourtsos, E.; Fountoulis, I.; Mavroulis, S.; Kranis, H.

    2012-04-01

    A series of forearc-dipping, orogen-parallel extensional faults are found in the central-western Peloponnesus, (south-western Aegean) which control the western margin of Mt Mainalon. The latter comprises HP/LT rocks of the Phyllites-Quartzites Unit (PQ), overlain by the carbonates and flysch of the Tripolis Unit while the uppermost nappe is the Pindos Unit, a sequence of Mesozoic pelagic sequence, topped by a Paleocene flysch. Most of the extensional structures were previously thought of as the original thrust between the Pindos and Tripolis Units. However, the cross-cutting relationships among these structures indicate that these are forearc (SW-dipping) extensional faults, downthrowing the Pindos thrust by a few tens or hundreds of meters each, rooting onto different levels of the nappe pile. In SW Mainalon the lowermost of the extensional faults is a low-angle normal fault dipping SW juxtaposing the metamorphic rocks of the PQ Unit against the non-metamorphic sequence of the Tripolis Unit. High-angle normal faults, found further to the west, have truncated or even sole onto the low-angle ones and control the eastern margin of the Quaternary Megalopolis basin. All these extensional structures form the eastern boundary of a series of Neogene-Quaternary tectonic depressions, which in turn are separated by E-W horsts. In the NW, these faults are truncated by NE to NNE-striking, NW-dipping faults, which relay the whole fault activity to the eastern margin of the Pyrgos graben. The whole extensional fault architecture has resulted (i) in the Pindos thrust stepping down from altitudes higher than 1000 m in Mainalon in the east, to negative heights in North Messinia and Southern Ilia in the west; and (ii) the gradual disappearance of the Phyllite-Quartzite metamorphics of Mainalon towards the west. The combination of these extensional faults (which may reach down to the Ionian décollement) with the low-angle floor thrusts of the Pindos, Tripolis and Ionian Units leads

  8. Estudio fitoquímico y farmacológico preliminar de plántulas de Alternanthera brasiliana cultivadas bajo diferentes cualidades espectrales de luz

    OpenAIRE

    Macedo, Andrea F.; Lage, Celso Luiz S.; Esquibel, María Aparecida; Souza, Márcia María de; Silva, Karina L. da; Niero,Rivaldo; Cechinel Filho, Valdir

    2004-01-01

    Extractos metanólicos de plántulas de Alternanthera brasiliana, cultivadas bajo diferentes cualidades espectrales de luz, fueron analizadas en dos modelos químicos de nocicepción en ratones. Los resultados mostraron mayor biomasa en las plántulas cultivadas con los tratamientos de luces azul y blanca. Extractos metanólicos (luces azules y blancas) administrados en concentraciones de 10 mg/kg del peso corporal, causaron inhibición de 51 y 62,5% para el test de contracciones y de 22...

  9. Recurring extensional and strike-slip tectonics after the Neoproterozoic collisional events in the southern Mantiqueira province

    Directory of Open Access Journals (Sweden)

    Renato P. Almeida

    2012-06-01

    Full Text Available In Eastern South America, a series of fault-bounded sedimentary basins that crop out from Southern Uruguay to Southeastern Brazil were formed after the main collisional deformation of the Brasiliano Orogeny and record the tectonic events that affected the region from the Middle Ediacaran onwards. We address the problem of discerning the basin-forming tectonics from the later deformational events through paleostress analysis of more than 600 fault-slip data, mainly from the Camaquã Basin (Southern Brazil, sorted by stratigraphic level and cross-cutting relationships of superposed striations, and integrated with available stratigraphic and geochronological data. Our results show that the Camaquã Basin was formed by at least two distinct extensional events, and that rapid paleostress changes took place in the region a few tens of million years after the major collision (c.a. 630 Ma, probably due to the interplay between local active extensional tectonics and the distal effects of the continued amalgamation of plates and terranes at the margins of the still-forming Gondwana Plate. Preliminary paleostress data from the Castro Basin and published data from the Itajaí Basin suggest that these events had a regional nature.No Leste da América do Sul, um conjunto de bacias sedimentares que afloram do sul do Uruguai ao sudeste do Brasil formou-se após os eventos colisionais da Orogenia Brasiliana, registrando os eventos tectônicos que afetaram a região a partir do Mesoediacarano. O problema da distinção entre a tectônica formadora das bacias e os eventos deformacionais posteriores é aqui abordado através da análise de paleotensões de mais de 600 dados de falhas com estrias, obtidos principalmente na Bacia Camaquã (Sul do Brasil, que foram classificados por nível estratigráfico e relações de corte entre estrias sobrepostas, e intergrados a dados estratigráficos e geocronológicos disponíveis. Nossos resultados revelam que a Bacia Camaqu

  10. Larval settlement and spat recovery rates of the oyster Crassostrea brasiliana (Lamarck, 1819) using different systems to induce metamorphosis.

    Science.gov (United States)

    Silveira, R C; Silva, F C; Gomes, C H M; Ferreira, J F; Melo, C M R

    2011-05-01

    This study aimed at the assessment, in the laboratory, of the larval settlement and spat recovery rates of oysters of the species Crassostrea brasiliana using plastic collectors, epinephrine (C9H13NO3 C4H6O6) and shell powder in settlement tanks. Polypropylene was used attached to bamboo frames. The material was chosen due to its pliability--that favours the spat detachment. Two experiments were carried out; the first between February and April 2008, and the second between November and December 2008 at the Marine Mussel Laboratory of Santa Catarina Federal University (Laboratório de Moluscos Marinhos da Universidade Federal de Santa Catarina). In the first experiment, the scratched plastic collectors were tested consorting them with shell powder; on the second, the plastic collectors were tested consorted with shell powder, only shell powder and epinephrine as the metamorphosis stimulator. The quantification was carried out of the larvae settled in the plastic collectors, and of the recovery and integrity of the spats after their detachment. The first experiment has shown a recovery rate of 48.83% of the spats in comparison with the D larvae used. From this percentage, 4.9% settled in the plastic collectors and 43.93% in shell powder. The second experiment revealed 55.78% regarding the settled spats in comparison with the total of larvae used (using epinephrine), 78.62% in the treatment with the collector plus shell powder and 58.33% in the treatment only with shell powder. Thus, the use of the collector plus shell powder resulted in a greater spat recovery when compared to the other treatments.

  11. Thiol oxidation of hemolymph proteins in oysters Crassostrea brasiliana as markers of oxidative damage induced by urban sewage exposure.

    Science.gov (United States)

    Trevisan, Rafael; Flores-Nunes, Fabrício; Dolores, Euler S; Mattos, Jacó J; Piazza, Clei E; Sasaki, Sílvio T; Taniguchi, Satie; Montone, Rosalinda C; Bícego, Márcia C; Dos Reis, Isis M M; Zacchi, Flávia L; Othero, Bárbara N M; Bastolla, Camila L V; Mello, Danielle F; Fraga, Ana Paula M; Wendt, Nestor; Toledo-Silva, Guilherme; Razzera, Guilherme; Dafre, Alcir L; de Melo, Cláudio M R; Bianchini, Adalto; Marques, Maria R F; Bainy, Afonso C D

    2017-07-01

    Urban sewage is a concerning issue worldwide, threatening both wildlife and human health. The present study investigated protein oxidation in mangrove oysters (Crassostrea brasiliana) exposed to seawater from Balneário Camboriú, an important tourist destination in Brazil that is affected by urban sewage. Oysters were exposed for 24 h to seawater collected close to the Camboriú River (CAM1) or 1 km away (CAM2). Seawater from an aquaculture laboratory was used as a reference. Local sewage input was marked by higher levels of coliforms, nitrogen, and phosphorus in seawater, as well as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), linear alkylbenzenes (LABs), and fecal steroid in sediments at CAM1. Exposure of oysters to CAM1 caused marked bioaccumulation of LABs and decreased PAH and PCB concentrations after exposure to both CAM1 and CAM2. Protein thiol oxidation in gills, digestive gland, and hemolymph was evaluated. Lower levels of reduced protein thiols were detected in hemolymph from CAM1, and actin, segon, and dominin were identified as targets of protein thiol oxidation. Dominin susceptibility to oxidation was confirmed in vitro by exposure to peroxides and hypochlorous acid, and 2 cysteine residues were identified as potential sites of oxidation. Overall, these data indicate that urban sewage contamination in local waters has a toxic potential and that protein thiol oxidation in hemolymph could be a useful biomarker of oxidative stress in bivalves exposed to contaminants. Environ Toxicol Chem 2017;36:1833-1845. © 2016 SETAC. © 2016 SETAC.

  12. A drop in uniaxial and biaxial nonlinear extensional flows

    Science.gov (United States)

    Favelukis, M.

    2017-08-01

    In this theoretical report, we explore small deformations of an initially spherical drop subjected to uniaxial or biaxial nonlinear extensional creeping flows. The problem is governed by the capillary number (Ca), the viscosity ratio (λ), and the nonlinear intensity of the flow (E). When the extensional flow is linear (E = 0), the familiar internal circulations are obtained and the same is true with E > 0, except that the external and internal flow rates increase with increasing E. If E 0) and oblate spheroidal drops for biaxial flows (Ca 0, the drop is more elongated than the linear case, while E 0 tends to facilitate drop breakup, while E < 0 makes drop breakup more difficult.

  13. Tumbling of a Brownian particle in an extensional flow

    CERN Document Server

    Plan, Emmanuel Lance Christopher VI Medillo

    2016-01-01

    The phenomenon of tumbling of microscopic objects is commonly associated with shear flows. We address the question of whether tumbling can also occur in stretching-dominated flows. To answer this, we study the dynamics of a semi-flexible trumbbell in a planar extensional velocity field. We show that the trumbbell undergoes a random tumbling-through-folding motion. The probability distribution of long tumbling times is exponential with a time scale exponentially increasing with the Weissenberg number.

  14. Stokes flow inside a sphere in an inviscid extensional flow

    Science.gov (United States)

    Krehbiel, Joel D.; Freund, Jonathan B.

    2017-08-01

    We derive the streamfunction solution for flow in and around a viscous sphere suspended in an inviscid extensional flow with matched stress boundary conditions, which is a model for estimating the stresses on a tiny suspended organism by a nearby expanding and collapsing bubble. The boundary conditions are enforced in an easily resolvable form by expressing the surface stresses as sums of Legendre and Gegenbauer functions. The flow inside the sphere reflects a balance of exterior inertia with internal viscous forces, which together are shown to constitute the relevant flow Reynolds number. The solution is evaluated to examine the flow field inside this sphere as a potential source of damage to the organism.

  15. A new look at extensional rheology of low-density polyethylene

    DEFF Research Database (Denmark)

    Huang, Qian; Mangnus, Marc; Alvarez, Nicolas J.

    2016-01-01

    The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU-FSR) and a co......The nonlinear rheology of three selected commercial low-density polyethylenes (LDPE) is measured in uniaxial extensional flow. The measurements are performed using three different devices including an extensional viscosity fixture (EVF), a homemade filament stretching rheometer (DTU....... With the capability of the filament stretching rheometers, we show that LDPEs with quite different linear viscoelastic properties can have very similar steady extensional viscosity. This points to the potential for independently controlling shear and extensional rheology in certain rate ranges....

  16. Determination of Extensional Rheological Properties by Hyperbolic Contraction Flow

    Science.gov (United States)

    Stading, Mats

    2008-07-01

    Extensional rheologyy is important for diverse applications such as processing of viscoelastic fluids, mouthfeel of semi-solid foods, cell mitosis and baking, and is also a useful tool for testing the applicability of constitutive equations. Despite the documented influence of extensional rheological properties, it is seldom measured due to experimental difficulties. There are only commercial equipments available for low-viscosity fluids by Capillary Breakup and for polymer melts by Meissner-type winding of ribbons around cylinders. Both methods have limited applicability for medium-viscosity fluids such as foods and other biological systems. Contraction flows are extensively studied and a new test method has been developed based on contraction flow through a hyperbolic nozzle. The method is suitable for medium-viscosity fluids and has been validated by comparison to results from Filament Stretching and Capillary Breakup. The hyperbolic contraction flow method has been used to characterize food and medical systems, distinguish between different products having equal shear behavior, quantify ropy mouth feel and to predict foaming behavior of biopolymers.

  17. Use of side-scan sonar for estimations of Crassostrea brasiliana (Lamarck, 1819 stocks in subtidal banks on the south coast of Brazil

    Directory of Open Access Journals (Sweden)

    Gisela Geraldine Castilho Westphal

    2016-03-01

    Full Text Available Abstract Uncontrolled extractivism has led to a worldwide reduction in oyster stocks. The use of new and more efficient management tools for impacted environments must increase. The application of such tools requires previous biological and environmental knowledge of the resident populations of these bivalve mollusks. Technical difficulties are usually associated with studies of submerged oyster banks, and these difficulties result in a considerable lack of biological data on the oysters that inhabit subtidal zones. This study aimed to survey Crassostrea brasiliana (also known as C. gasar stocks in submerged banks and to evaluate a method with which to measure the extent of the banks and identify and quantify the oysters in the banks with the use of side-scan sonar. This study was conducted on 10 oysters banks located in the subtidal zone of Guaratuba Bay, on the south coast of Brazil. The prospection of all these banks was later validated by diving, and oyster samples (n = 20/bank were collected for species identification with a molecular method. Only one bank contained oysters that were generically classified as Crassostrea sp.; those in the remaining banks being identified as C. brasiliana. The prospected banks contained oysters of various sizes (average 1.5 m, n = 1,107 that were heterogeneously scattered in the riverbeds. The total number of oysters in the 10 sampled banks was estimated to be 21,159.13 oysters or 1 oyster/4.5 m², which represents a low oyster density in the study site. The results validate the use of side-scan sonar as an efficient means with which to prospect for oysters in banks located within subtidal zones.

  18. Shear and Extensional Rheology of Polystyrene Melts and Solutions with the Same Number of Entanglements

    DEFF Research Database (Denmark)

    Costanzo, Salvatore; Huang, Qian; Ianniruberto, Giovanni

    2016-01-01

    We investigate the nonlinear shear and uniaxial extensional rheology of entangled polystyrene (PS) melts and solutions having the same number Z of entanglements, hence identical linear viscoelasticity. While experiments in extensional flows confirm that PS melts and solutions with the same Z behave...

  19. Extensional channel flow revisited: a dynamical systems perspective

    Science.gov (United States)

    Marques, Francisco; Meseguer, Alvaro; Mellibovsky, Fernando; Weidman, Patrick D.

    2017-06-01

    Extensional self-similar flows in a channel are explored numerically for arbitrary stretching-shrinking rates of the confining parallel walls. The present analysis embraces time integrations, and continuations of steady and periodic solutions unfolded in the parameter space. Previous studies focused on the analysis of branches of steady solutions for particular stretching-shrinking rates, although recent studies focused also on the dynamical aspects of the problems. We have adopted a dynamical systems perspective, analysing the instabilities and bifurcations the base state undergoes when increasing the Reynolds number. It has been found that the base state becomes unstable for small Reynolds numbers, and a transitional region including complex dynamics takes place at intermediate Reynolds numbers, depending on the wall acceleration values. The base flow instabilities are constitutive parts of different codimension-two bifurcations that control the dynamics in parameter space. For large Reynolds numbers, the restriction to self-similarity results in simple flows with no realistic behaviour, but the flows obtained in the transition region can be a valuable tool for the understanding of the dynamics of realistic Navier-Stokes solutions.

  20. Dumbbell formation for elastic capsules in nonlinear extensional Stokes flows

    Science.gov (United States)

    Dimitrakopoulos, P.

    2017-06-01

    Cross-slot and four-roll-mill microdevices are commonly used for particle manipulation and characterization owing to the stagnation-point flow at the device center. Because of the solid boundaries, these devices may generate extensional Stokes flows where the velocity is a nonlinear function of position associated with a decreased pressure at the particle edges and an increased pressure at the particle middle. Our computational investigation shows that in this class of Stokes flows, an elastic capsule made of a strain-hardening membrane develops two distinct steady-state conformations at strong flows, i.e., an elongated weak dumbbell shape with rounded edges at low flow nonlinearity and a laterally extended dumbbell shape at high flow nonlinearity. These effects are more pronounced for the less strain-hardening capsules which develop a flat extended middle where the two sides of the membrane approach each other. The strong stability properties of the strain-hardening capsules (owing to the development of strong membrane tensions) contrast significantly with the behavior of droplets in these nonlinear flows which are unable to achieve highly deformed steady-state dumbbell shapes owing to their constant surface tension.

  1. Extensional Tectonic Regime of Garut Basin based on Magnetotelluric Analysis

    Directory of Open Access Journals (Sweden)

    Lina Handayani

    2014-07-01

    Full Text Available DOI: 10.17014/ijog.v8i3.162Garut Basin are is part of Bandung-Garut Greater Basin (Bandung Zone characterized by a large basin surrounded by mountain ranges. Active volcanoes had distributed their material as pyroclastic deposits around the outer border of the zone and as lava flow deposit separating the two basins. Bouguer gravity anomaly data had also indicated the presence of several low anomaly closures at about the area of Bandung and Garut Basins that were surrounded by high gravity anomaly zones. Two magnetotelluric surveys were completed to acquire the subsurface model that might explain the tectonic evolution of studied area. The first stage was characterized sby the presence of horst - graben structures that might imply an extensional regime of the area. The next stage of evolutionwas indicated by the horizontal layering correlated to the relative non-active tectonic. In addition, a most recent structure that appeared near the surface might suggest a possible extension force as the current stage.

  2. The effect of shear and extensional viscosity on atomization in medical inhaler.

    Science.gov (United States)

    Broniarz-Press, L; Ochowiak, M; Matuszak, M; Włodarczak, S

    2014-07-01

    The paper contains the results of experimental studies of water, aqueous solutions of glycerol and aqueous solutions of glycerol-polyethylene oxide (PEO) atomization process in a medical inhaler obtained by the use of the digital microphotography method. The effect of the shear and extensional viscosity on the drop size, drop size histogram and mean drop diameter has been analyzed. The obtained results have shown that the drop size increases with the increase in shear and extensional viscosity of liquid atomized. Extensional viscosity has a greater impact on the spraying process. It has been shown that the change in liquid viscosity leads to significant changes in drop size distribution. The correlation for Sauter mean diameter as function of the shear and extensional viscosity was proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Shear History Extensional Rheology Experiment II (SHERE II) Microgravity Rheology with Non-Newtonian Polymeric Fluids

    Science.gov (United States)

    Jaishankar, Aditya; Haward, Simon; Hall, Nancy Rabel; Magee, Kevin; McKinley, Gareth

    2012-01-01

    The primary objective of SHERE II is to study the effect of torsional preshear on the subsequent extensional behavior of filled viscoelastic suspensions. Microgravity environment eliminates gravitational sagging that makes Earth-based experiments of extensional rheology challenging. Experiments may serve as an idealized model system to study the properties of lunar regolith-polymeric binder based construction materials. Filled polymeric suspensions are ubiquitous in foods, cosmetics, detergents, biomedical materials, etc.

  4. Evaluation of the cholinomimetic actions of trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana (Gastropoda, Opisthobranchia

    Directory of Open Access Journals (Sweden)

    C.M. Kerchove

    2002-04-01

    Full Text Available Trimethylsulfonium, a compound present in the midgut gland of the sea hare Aplysia brasiliana, negatively modulates vagal response, indicating a probable ability to inhibit cholinergic responses. In the present study, the pharmacological profile of trimethylsulfonium was characterized on muscarinic and nicotinic acetylcholine receptors. In rat jejunum the contractile response induced by trimethylsulfonium (pD2 = 2.46 ± 0.12 and maximal response = 2.14 ± 0.32 g was not antagonized competitively by atropine. The maximal response (Emax to trimethylsulfonium was diminished in the presence of increasing doses of atropine (P<0.05, suggesting that trimethylsulfonium-induced contraction was not related to muscarinic stimulation, but might be caused by acetylcholine release due to presynaptic stimulation. Trimethylsulfonium displaced [³H]-quinuclidinyl benzilate from rat cortex membranes with a low affinity (Ki = 0.5 mM. Furthermore, it caused contraction of frog rectus abdominis muscles (pD2 = 2.70 ± 0.06 and Emax = 4.16 ± 0.9 g, which was competitively antagonized by d-tubocurarine (1, 3 or 10 µM with a pA2 of 5.79, suggesting a positive interaction with nicotinic receptors. In fact, trimethylsulfonium displaced [³H]-nicotine from rat diaphragm muscle membranes with a Ki of 27.1 µM. These results suggest that trimethylsulfonium acts as an agonist on nicotinic receptors, and thus contracts frog skeletal rectus abdominis muscle and rat jejunum smooth muscle via stimulation of postjunctional and neuronal prejunctional nicotinic cholinoreceptors, respectively.

  5. Deformation and Stress Response of Carbon Nanotubes/UHMWPE Composites under Extensional-Shear Coupling Flow

    Science.gov (United States)

    Wang, Junxia; Cao, Changlin; Yu, Dingshan; Chen, Xudong

    2017-05-01

    In this paper, the effect of varying extensional-shear couple loading on deformation and stress response of Carbon Nanotubes/ ultra-high molecular weight polyethylene (CNTs/UHMWPE) composites was investigated using finite element numerical simulation, with expect to improve the manufacturing process of UHMWPE-based composites with reduced stress and lower distortion. When applying pure extensional loading and pure X-Y shear loading, it was found that the risk of a structural breakage greatly rises. For identifying the coupling between extensional and shear loading, distinct generations of force loading were defined by adjusting the magnitude of extensional loading and X-Y shear loading. It was shown that with the decrement of X-Y shear loading the deformation decreases obviously where the maximal Mises stress in Z-direction at 0.45 m distance is in the range from 24 to 10 MPa and the maximal shear stress at 0.61 m distance is within the range from 0.9 to 0.3 MPa. In addition, all the stresses determined were clearly below the yield strength of CNTs/UHMWPE composites under extensional-shear couple loading.

  6. Capillary break-up, gelation and extensional rheology of hydrophobically modified cellulose ethers

    Science.gov (United States)

    Sharma, Vivek; Haward, Simon; Pessinet, Olivia; Soderlund, Asa; Threlfall-Holmes, Phil; McKinley, Gareth

    2012-02-01

    Cellulose derivatives containing associating hydrophobic groups along their hydrophilic polysaccharide backbone are used extensively in the formulations for inks, water-borne paints, food, nasal sprays, cosmetics, insecticides, fertilizers and bio-assays to control the rheology and processing behavior of multi-component dispersions. These complex dispersions are processed and used over a broad range of shear and extensional rates. The presence of hydrophobic stickers influences the linear and nonlinear rheology of cellulose ether solutions. In this talk, we systematically contrast the difference in the shear and extensional rheology of a cellulose ether: ethy-hydroxyethyl-cellulose (EHEC) and its hydrophobically-modified analog (HMEHEC) using microfluidic shear rheometry at deformation rates up to 10^6 inverse seconds, cross-slot flow extensional rheometry and capillary break-up during jetting as a rheometric technique. Additionally, we provide a constitutive model based on fractional calculus to describe the physical gelation in HMEHEC solutions.

  7. Deep seismic investigation of crustal extensional structures in the Danish Basin along the ESTRID-2 profile

    DEFF Research Database (Denmark)

    Sandrin, Alessandro; Thybo, Hans

    2008-01-01

    The crust and uppermost mantle in the Danish Basin are investigated by modelling the P-wave velocity distribution along the north-south trending seismic profile ESTRID-2. Seismic tomography and ray inversion modelling demonstrate a variable depth to the top of the crystalline crust, from ~10 km...... to magmatic underplating. The occurrence of a large crustal mafic intrusion associated with magmatic underplating may be related to extensional/transtensional tectonism in the Tornquist Fan area in the Late Palaeozoic. The extensional event probably caused the opening of a plumbing system for intrusion...

  8. The missing link between the extensional dynamics of polymer melts and solutions

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Huang, Qian

    2014-01-01

    Based on extensional viscosities measured on narrow molecular weight distributed (NMMD) polystyrenes and polystyrene oligomer dilutions thereof, we discuss the relation between the flow physics of polymer solutions and melts. A polymer solution is here characterized as a dilution where the diluent...... contains less than two Kuhn steps. At the same entanglement number (e.g. concentrations) its extensional viscosities are up to about 300% higher than the corresponding viscosities for polymer blends. A blend is understood as a polymer system diluted with polymer/oligomer containing active chain in term...

  9. Extensional viscosity of copper nanowire suspensions in an aqueous polymer solution

    OpenAIRE

    McDonnell, Amarin G.; Jason, Naveen N.; Yeo, Leslie Y.; James R. Friend; Cheng, Wenlong; Prabhakar, Ranganathan

    2015-01-01

    Suspensions of copper nanowires are emerging as new electronic inks for next-generation flexible electronics. Using a novel surface acoustic wave driven extensional flow technique we are able to perform currently lacking analysis of these suspensions and their complex buffer. We observe extensional viscosities from 3 mPa$\\cdot$s (1 mPa$\\cdot$s shear viscosity) to 37.2 Pa$\\cdot$s via changes in the suspension concentration, thus capturing low viscosities that have been historically very challe...

  10. Generalized thermoelastic extensional and flexural wave motions in homogenous isotropic plate by using asymptotic method

    Science.gov (United States)

    Sharma, J. N.; Sharma, P. K.; Rana, S. K.

    2011-01-01

    In this paper the asymptotic method has been applied to investigate propagation of generalized thermoelastic waves in an infinite homogenous isotropic plate. The governing equations for the extensional, transversal and flexural motions are derived from the system of three-dimensional dynamical equations of linear theories of generalized thermoelasticity. The asymptotic operator plate model for extensional and flexural free vibrations in a homogenous thermoelastic plate leads to sixth and fifth degree polynomial secular equations, respectively. These secular equations govern frequency and phase velocity of various possible modes of wave propagation at all wavelengths. The velocity dispersion equations for extensional and flexural wave motion are deduced from the three-dimensional analog of Rayleigh-Lamb frequency equation for thermoelastic plate. The approximation for long and short waves along with expression for group velocity has also been obtained. The Rayleigh-Lamb frequency equations for the considered plate are expanded in power series in order to obtain polynomial frequency and velocity dispersion relations and its equivalence established with that of asymptotic method. The numeric values for phase velocity, group velocity and attenuation coefficients has also been obtained using MATHCAD software and are shown graphically for extensional and flexural waves in generalized theories of thermoelastic plate for solid helium material.

  11. Middle Miocene E-W tectonic horst structure of Crete through extensional detachment faults

    Science.gov (United States)

    Papanikolaou, D.; Vassilakis, E.

    2008-07-01

    Two east-west trending extensional detachment faults have been recognized in Crete, one with top-to-the-north motion of the hanging wall toward the Cretan Sea and one with top-to-the-south motion of the hanging wall toward the Libyan Sea. The east-west trending zone between these two detachment faults, which forms their common footwall, comprises a tectonic horst formed during Middle Miocene slip on the detachment faults. The detachment faults disrupt the overall tectono-stratigraphic succession of Crete and are localized along pre-existing thrust faults and along particular portions of the stratigraphic sequence, including the transition between the Permo-Triassic Tyros Beds and the base of the Upper Triassic-Eocene carbonate platform of the Tripolis nappe. By recognizing several different tectono-stratigraphic formations within what is generally termed the 'phyllite-quartzite', it is possible to distinguish these extensional detachment faults from thrust faults and minor discontinuities in the sequence. The deformation history of units within Crete can be summarized as: (i) compressional deformation producing arc-parallel east-west trending south-directed thrust faults in Oligocene to Early Miocene time (ii) extensional deformation along arc-parallel, east-west trending detachment faults in Middle Miocene time, with hanging wall motion to the north and south; (iii) Late Miocene-Quaternary extensional deformation along high-angle normal and oblique normal faults that disrupt the older arc-parallel structures.

  12. Middle Miocene E-W tectonic horst structure of Crete through extensional detachment faults

    Energy Technology Data Exchange (ETDEWEB)

    Papanikolaou, D [Professor of Dynamics and Tectonics, School of Geology and Geoenvironment, Department of Dynamics, Tectonics and Applied Geology, National and Kapodestrian University of Athens, 15784 (Greece); Vassilakis, E [Research Scientist, School of Geology and Geoenvironment, Department of Dynamics, Tectonics and Applied Geology, National and Kapodestrian University of Athens, 15784 (Greece)], E-mail: dpapan@geol.uoa.gr, E-mail: evasilak@geol.uoa.gr

    2008-07-01

    Two east-west trending extensional detachment faults have been recognized in Crete, one with top-to-the-north motion of the hanging wall toward the Cretan Sea and one with top-to-the-south motion of the hanging wall toward the Libyan Sea. The east-west trending zone between these two detachment faults, which forms their common footwall, comprises a tectonic horst formed during Middle Miocene slip on the detachment faults. The detachment faults disrupt the overall tectono-stratigraphic succession of Crete and are localized along pre-existing thrust faults and along particular portions of the stratigraphic sequence, including the transition between the Permo-Triassic Tyros Beds and the base of the Upper Triassic-Eocene carbonate platform of the Tripolis nappe. By recognizing several different tectono-stratigraphic formations within what is generally termed the 'phyllite-quartzite', it is possible to distinguish these extensional detachment faults from thrust faults and minor discontinuities in the sequence. The deformation history of units within Crete can be summarized as: (i) compressional deformation producing arc-parallel east-west trending south-directed thrust faults in Oligocene to Early Miocene time (ii) extensional deformation along arc-parallel, east-west trending detachment faults in Middle Miocene time, with hanging wall motion to the north and south; (iii) Late Miocene-Quaternary extensional deformation along high-angle normal and oblique normal faults that disrupt the older arc-parallel structures.

  13. Monitoring the hydration of DNA self-assembled monolayers using an extensional nanomechanical resonator

    DEFF Research Database (Denmark)

    Cagliani, Alberto; Kosaka, Priscila; Tamayo, Javier

    2012-01-01

    We have fabricated an ultrasensitive nanomechanical resonator based on the extensional vibration mode to weigh the adsorbed water on self-assembled monolayers of DNA as a function of the relative humidity. The water adsorption isotherms provide the number of adsorbed water molecules per nucleotid...

  14. Bridging the Gap between Polymer Melts and Solutions in Extensional Rheology

    DEFF Research Database (Denmark)

    Huang, Qian; Hengeller, Ludovica; Alvarez, Nicolas J.

    2015-01-01

    and polymer melts. We compare the nonlinear extensional rheology of a series of polystyrene solutions with wide concentration range between 10% and 100% (melt) in order to determine the key missing physics that can account for dilution effects. All the solutions studied have the same number of entanglements...

  15. Extensional rheology of entangled polystyrene solutions suggests importance of nematic interactions

    DEFF Research Database (Denmark)

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi

    polymer solutions in extensional flow. We prepared three polystyrene (PS) solutions with identical concentrations of the same PS sample (with the molecular weight M = 545k), but diluted with three different solvents, oligomeric styrene (OS) with M = 1k, 2k, and 4k. The three solutions have exactly...

  16. Non-linear Shear and Uniaxial Extensional Rheology of Polyether-Ester-Sulfonate Copolymer Ionomer Melts

    DEFF Research Database (Denmark)

    Shabbir, Aamir; Huang, Qian; P. Baeza, Guilhem

    2017-01-01

    We present unique nonlinear shear and extensional rheology data of unentan-gled amorphous polyester ionomers based on polyethers and sulphonated phthalates with sodium/ lithium counterions. Previous linear viscoelastic (LVE) measurements1 showed significant elasticity in these ionomers due...

  17. Geocronologia e aspectos estruturais e petrológicos do Pluton Bravo, Domínio Central da Província Borborema, Nordeste do Brasil: um granito transalcalino precoce no estágio pós-colisional da Orogênese Brasiliana

    Directory of Open Access Journals (Sweden)

    Geysson de Almeida Lages

    Full Text Available RESUMO: O Pluton Bravo (no Estado da Paraíba constitui um stock elipsoidal formado por monzo/sienogranitos porfiríticos, enclaves dioritos e zonas híbridas. Está intrudido em gnaisses migmatíticos paleoproterozoicos do Domínio Central da Província Borborema. Os sienogranitos são metaluminosos a levemente peraluminosos, e exibem altas razões de K2O/Na2O > 1,5 e FeOt/(FeOt + MgO > 0,86. Os dioritos possuem alto conteúdo de Zr (> 1.134 ppm, TiO2 ~ 1,6% e Nb > (49 ppm. As razões (LaN/YbNN estão entre 14 e 19,4, e (Eu/Eu*N, entre 0,31 e 0,37. As rochas do Pluton Bravo são moderadamente fracionadas com picos em La, Zr e forte depressão em P, Ti e menor em Sr. Os dados plotam no campo discriminante de granitos pós-tectônicos/intraplaca. As estimativas de pressão (4,4 a 6,0 Kbar baseadas no conteúdo de Alt em anfibólio sugerem posicionamento do pluton na crosta superior a média. A temperatura do liquidus de acordo com o conteúdo de Zr e SiO2 oscilou entre 847 e 893°C, e a de cristalização, calculada pelo par anfibólio-plagioclásio, entre 581 e 785°C. Exibem idades-modelo TDM = 2,35 a 2,18 e εNd (580 Ma = -18,32 a -17,03. A idade U-Pb (LA-MC-ICP-MS U-Th-Pb em zircão indica cristalização ao redor de 581 ± 2 Ma. A relação entre a idade de cristalização (~ 580 Ma, as características químicas de granito tipo-A, idades-modelo Sm-Nd maiores que 2,1 Ga e a associação com regime tectônico transcorrente contrastam com outros granitos similares, porém ligeiramente mais novos (~ 570 Ma, que ocorrem nos Domínios Central, Rio Grande do Norte e no leste da Nigéria. Isso sugere que a transição do regime compressional para direcional/componente extensional precedeu no caso deste corpo evidenciando o caráter episódico e diacrônico da Orogênese Brasiliana. Conclui-se que o Pluton Bravo constitui um bom exemplo de magmatismo pós-colisional transalcalino no Domínio Central, que, com outros exemplos no Domínio Rio Grande

  18. Larval settlement and spat recovery rates of the oyster Crassostrea brasiliana (Lamarck, 1819 using different systems to induce metamorphosis Taxas de assentamento larval e recuperação de sementes da ostra Crassostrea brasiliana (Lamarck, 1819 com uso de diferentes sistemas de indução à metamorfose

    Directory of Open Access Journals (Sweden)

    RC Silveira

    2011-05-01

    Full Text Available This study aimed at the assessment, in the laboratory, of the larval settlement and spat recovery rates of oysters of the species Crassostrea brasiliana using plastic collectors, epinephrine (C9H13NO3 C4H6O6 and shell powder in settlement tanks. Polypropylene was used attached to bamboo frames. The material was chosen due to its pliability - that favours the spat detachment. Two experiments were carried out; the first between February and April 2008, and the second between November and December 2008 at the Marine Mussel Laboratory of Santa Catarina Federal University (Laboratório de Moluscos Marinhos da Universidade Federal de Santa Catarina. In the first experiment, the scratched plastic collectors were tested consorting them with shell powder; on the second, the plastic collectors were tested consorted with shell powder, only shell powder and epinephrine as the metamorphosis stimulator. The quantification was carried out of the larvae settled in the plastic collectors, and of the recovery and integrity of the spats after their detachment. The first experiment has shown a recovery rate of 48.83% of the spats in comparison with the D larvae used. From this percentage, 4.9% settled in the plastic collectors and 43.93% in shell powder. The second experiment revealed 55.78% regarding the settled spats in comparison with the total of larvae used (using epinephrine, 78.62% in the treatment with the collector plus shell powder and 58.33% in the treatment only with shell powder. Thus, the use of the collector plus shell powder resulted in a greater spat recovery when compared to the other treatments.O presente estudo teve como objetivo avaliar a taxa de assentamento larval e recuperação de sementes de ostras da espécie Crassostrea brasiliana, em laboratório, através do uso de coletores plásticos, epinefrina (C9H13NO3 C4H6O6 e pó de concha em tanques de assentamento. Foram utilizados coletores plásticos de polipropileno, presos a armações de

  19. The transition between undiluted and oligomer-diluted states of nearly monodisperse polystyrenes in extensional flow

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik K.

    2017-01-01

    We have measured the startup and steady extensional viscosity of two narrow molar mass distributed (NMMD) polystyrenes, a 910 kg/mole and a 545 kg/mole, diluted in a NMMD 4.29 kg/mole styrene oligomer, with a wide concentration range from 90 down to 17%. The constant interchain pressure model......, proposed by Rasmussen and Huang (Rheol Acta 53(3):199–208 (2014a)), predicts the extensional viscosity well for the dilutions with lower concentrations. However, for the 70 and 90% 545 kg/mole samples which represent the transition between the diluted and undiluted states, the model predictions are less...... satisfactory. Another concept based on interchain pressure, proposed by Wagner (Rheol Acta 53(10):765–777 (2014)), also shows agreement with the measured data....

  20. The rheology of aqueous solutions of ethyl hydroxy-ethyl cellulose (EHEC) and its hydrophobically modified analogue (hmEHEC): extensional flow response in capillary break-up, jetting (ROJER) and in a cross-slot extensional rheometer.

    Science.gov (United States)

    Sharma, Vivek; Haward, Simon J; Serdy, James; Keshavarz, Bavand; Soderlund, Asa; Threlfall-Holmes, Phil; McKinley, Gareth H

    2015-04-28

    Cellulose derivatives containing associating hydrophobic groups along their hydrophilic backbone are used as rheology modifiers in the formulation of water-based spray paints, medicinal sprays, cosmetics and printable inks. Jetting and spraying applications of these materials involve progressive thinning and break-up of a fluid column or sheet into drops. Strong extensional kinematics develop in the thinning fluid neck. In viscous Newtonian fluids, inertial and viscous stresses oppose the surface tension-driven instability. In aqueous solutions of polymers such as Ethyl Hydroxy-Ethyl Cellulose (EHEC), chain elongation provides additional elastic stresses that can delay the capillary-driven pinch-off, influencing the sprayability or jettability of the complex fluid. In this study, we quantify the transient response of thinning filaments of cellulose ether solutions to extensional flows in a Capillary Break-up Extensional Rheometer (CaBER) and in a forced jet undergoing break-up using Rayleigh Ohnesorge Jetting Extensional Rheometry (ROJER). We also characterize the steady state molecular deformations using measurements of the flow-induced birefringence and excess pressure drop in an extensional stagnation point flow using a Cross-Slot Extensional Rheometer (CSER). We show that under the high extension rates encountered in jetting and spraying, the semi-dilute solutions of hydrophobically modified ethyl hydroxy-ethyl cellulose (hmEHEC) exhibit extensional thinning, while the unmodified bare chains of EHEC display an increase in extensional viscosity, up to a plateau value. For both EHEC and hmEHEC dispersions, the low extensibility of the cellulose derivatives limits the Trouton ratio observed at the highest extension rates attained (close to 10(5) s(-1)) to around 10-20. The reduction in extensional viscosity with increasing extension rate for the hydrophobically modified cellulose ether is primarily caused by the disruption of a transient elastic network that is

  1. Tectonic Exhumation and Climate Driven Erosion in Extensional Mountain Blocks: Two Examples from California, USA

    OpenAIRE

    Mason, Cody Curtis

    2017-01-01

    The Pacific-North America plate boundary in central and southern California has a complex tectonic history, and constraints are poor for inception of an extensional fault system linked to the southern San Andreas fault, a major tectonic element of this plate boundary. Furthermore, decades of research has shown relationships between climate, tectonics, and surface processes in most orogens across the globe (e.g. Alps, Himalaya, Andes, Alaska Ranges), however the role climate plays in modulatin...

  2. Interchain tube pressure effect in extensional flows of oligomer diluted nearly monodisperse polystyrene melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Huang, Qian

    2014-01-01

    times and entanglements have been established based on published extensional experiments on nearly monodisperse polystyrene melts. The constitutive equation has shown agreement with the experimental startup of and steady extension data from Huang et al. (Macromolecules 46:5026–5035, 2013a) based on 285...... and 545 kg/mol polystyrenes diluted in styrene oligomers containing 3.3 (1.92 kg/mol) and 7.3 (4.29 kg/mol) Kuhn steps....

  3. Spreading vs. Rifting as modes of extensional tectonics on the globally expanded Ganymede

    Science.gov (United States)

    Pizzi, Alberto; di Domenica, Alessandra; Komatsu, Goro; Cofano, Alessandra; Mitri, Giuseppe; Bruzzone, Lorenzo

    2017-05-01

    The formation of Ganymede's sulci is likely related to extensional tectonics that affected this largest icy satellite of Jupiter. Through geometric and structural analyses we reconstructed the pre-deformed terrains and we recognized two different modes of extension associated with sulci. In the first mode, smooth sulci constitute spreading centers between two dark terrain plates, similar to the fast oceanic spreading centers on Earth. Here extension is primarily accommodated by crustal accretion of newly formed icy crust. In the second mode, dark terrain extension is mainly accommodated by swaths of normal fault systems analogous to Earth's continental crustal rifts. A comparison with terrestrial extensional analogues, based on the fault displacement/length (Dmax/L) ratio, spacing and morphology, showed that magmato-tectonic spreading centers and continental crustal rifts on Earth follow the same relative patterns observed on Ganymede. Our results suggest that the amount of extensional strain may have previously been underestimated since the occurrence of spreading centers may have played a major role in the tectonic evolution of the globally expanded Ganymede. We also discuss a possible model for the origin of the different modes of extension in the context of the global expansion of the satellite.

  4. Transpressional inversion in an extensional transfer zone (the Saltacaballos fault, northern Spain)

    Science.gov (United States)

    Quintana, Luís; Alonso, Juan Luís; Pulgar, Javier A.; Rodríguez-Fernández, Luís Roberto

    2006-11-01

    This paper deals with an extensional transfer zone and its main structure, the Saltacaballos fault, developed during Early Cretaceous times, and obliquely inverted during the Alpine shortening. Geological mapping and structural analysis were carried out to determine the kinematic history of the deformation. The Saltacaballos ridge is the relay zone between two major and conjugate normal fault systems: the Bilbao and the La Granja-Samano fault systems. Three distinct phases in the structural evolution of this transfer zone can be identified. (1) During the initial stages of extensional deformation, shallow-water marine limestones were deposited on the relay ridge and deep-water marls on the flanking depocenters. At the same time, submarine landslides developed on paleoslope generated either by normal drag or by a fault-propagation fold related to the Saltacaballos normal fault. (2) With increasing displacement, normal faults antithetic to the Saltacaballos fault were developed probably in response to the collapse of its hanging-wall. (3) During the subsequent Alpine compressional stage, these normal faults were reactivated as dextral strike-slip faults as a result of transpressional inversion, whereas previous extensional fault-related folds were tightened. At the same time, some normal faults were overturned as a consequence of passive rotation in fold limbs.

  5. Extensional viscosity of copper nanowire suspensions in an aqueous polymer solution.

    Science.gov (United States)

    McDonnell, Amarin G; Jason, Naveen N; Yeo, Leslie Y; Friend, James R; Cheng, Wenlong; Prabhakar, Ranganathan

    2015-11-07

    Suspensions of copper nanowires are emerging as new electronic inks for next-generation flexible electronics. Using a novel surface acoustic wave driven extensional flow technique we are able to perform currently lacking analysis of these suspensions and their complex buffer. We observe extensional viscosities from 3 mPa s (1 mPa s shear viscosity) to 37.2 Pa s via changes in the suspension concentration, thus capturing low viscosities that have been historically very challenging to measure. These changes equate to an increase in the relative extensional viscosity of nearly 12,200 times at a volume fraction of just 0.027. We also find that interactions between the wires and the necessary polymer additive affect the rheology strongly. Polymer-induced elasticity shows a reduction as the buffer relaxation time falls from 819 to 59 μs above a critical particle concentration. The results and technique presented here should aid in the future formulation of these promising nanowire suspensions and their efficient application as inks and coatings.

  6. Extensional tectonics and sedimentary response of the Early–Middle Cambrian passive continental margin, Tarim Basin, Northwest China

    OpenAIRE

    Zhiqian Gao; Tailiang Fan

    2012-01-01

    The fact that several half-grabens and normal faults developed in the Lower–Middle Cambrian of Tazhong (central Tarim Basin) and Bachu areas in Tarim Basin, northwest China, indicates that Tarim Basin was under extensional tectonic setting at this time. The half-grabens occur within a linear zone and the normal faults are arranged in en echelon patterns with gradually increasing displacement eastward. Extensional tectonics resulted in the formation of a passive continental margin in the south...

  7. Two-stage partial melting during the Variscan extensional tectonics (Montagne Noire, France)

    Science.gov (United States)

    Poujol, Marc; Pitra, Pavel; Van Den Driessche, Jean; Tartèse, Romain; Ruffet, Gilles; Paquette, Jean-Louis; Poilvet, Jean-Charles

    2017-03-01

    One of the striking features that characterise the late stages of the Variscan orogeny is the development of gneiss and migmatite domes, as well as extensional Late Carboniferous and Permian sedimentary basins. It remains a matter of debate whether the formation of domes was related to the well-documented late orogenic extension or to the contractional tectonics that preceded. Migmatization and magmatism are expected to predate extension if the domes are compression-related regional anticlines, but they must both precede and be contemporaneous with extension if they are extensional core complexes. In the Montagne Noire area (southern French Massif Central), where migmatization, magmatism and the deformation framework are well documented, the age of the extensional event was unequivocally constrained to 300-290 Ma. Therefore, dating migmatization in this area is a key point for discriminating between the two hypotheses and understanding the Late Palaeozoic evolution of this part of the Variscan belt. For this purpose, a migmatite and an associated anatectic granite from the Montagne Noire dome were dated by LA-ICP-MS (U-Th-Pb on zircon and monazite) and laser probe 40Ar-39Ar (K-Ar on muscovite). Although zircon did not record any Variscan age unequivocally related to compression (380-330 Ma), two age groups were identified from the monazite crystals. A first event, at ca. 319 Ma (U-Th-Pb on monazite), is interpreted as a first stage of migmatization and as the emplacement age of the granite, respectively. A second event at ca. 298-295 Ma, recorded by monazite (U-Th-Pb) and by the muscovite 40Ar-39Ar system in the migmatite and in the granite, could be interpreted as a fluid-induced event, probably related to a second melting event identified through the syn-extensional emplacement of the nearby Montalet leucogranite ca. 295 Ma ago. The ages of these two events post-date the Variscan compression and agree with an overall extensional context for the development of the

  8. Risk of shear failure and extensional failure around over-stressed excavations in brittle rock

    Directory of Open Access Journals (Sweden)

    Nick Barton

    2017-04-01

    Full Text Available The authors investigate the failure modes surrounding over-stressed tunnels in rock. Three lines of investigation are employed: failure in over-stressed three-dimensional (3D models of tunnels bored under 3D stress, failure modes in two-dimensional (2D numerical simulations of 1000 m and 2000 m deep tunnels using FRACOD, both in intact rock and in rock masses with one or two joint sets, and finally, observations in TBM (tunnel boring machine tunnels in hard and medium hard massive rocks. The reason for ‘stress-induced’ failure to initiate, when the assumed maximum tangential stress is approximately (0.4–0.5σc (UCS, uniaxial compressive strength in massive rock, is now known to be due to exceedance of a critical extensional strain which is generated by a Poisson's ratio effect. However, because similar ‘stress/strength’ failure limits are found in mining, nuclear waste research excavations, and deep road tunnels in Norway, one is easily misled into thinking of compressive stress induced failure. Because of this, the empirical SRF (stress reduction factor in the Q-system is set to accelerate as the estimated ratio σθmax/σc >> 0.4. In mining, similar ‘stress/strength’ ratios are used to suggest depth of break-out. The reality behind the fracture initiation stress/strength ratio of ‘0.4’ is actually because of combinations of familiar tensile and compressive strength ratios (such as 10 with Poisson's ratio (say 0.25. We exceed the extensional strain limits and start to see acoustic emission (AE when tangential stress σθ ≈ 0.4σc, due to simple arithmetic. The combination of 2D theoretical FRACOD models and actual tunnelling suggests frequent initiation of failure by ‘stable’ extensional strain fracturing, but propagation in ‘unstable’ and therefore dynamic shearing. In the case of very deep tunnels (and 3D physical simulations, compressive stresses may be too high for extensional strain fracturing, and

  9. Human red blood cell behavior under homogeneous extensional flow in a hyperbolic-shaped microchannel.

    Science.gov (United States)

    Yaginuma, T; Oliveira, M S N; Lima, R; Ishikawa, T; Yamaguchi, T

    2013-01-01

    It is well known that certain pathological conditions result in a decrease of red blood cells (RBCs) deformability and subsequently can significantly alter the blood flow in microcirculation, which may block capillaries and cause ischemia in the tissues. Microfluidic systems able to obtain reliable quantitative measurements of RBC deformability hold the key to understand and diagnose RBC related diseases. In this work, a microfluidic system composed of a microchannel with a hyperbolic-shaped contraction followed by a sudden expansion is presented. We provide a detailed quantitative description of the degree of deformation of human RBCs under a controlled homogeneous extensional flow field. We measured the deformation index (DI) as well as the velocity of the RBCs travelling along the centerline of the channel for four different flow rates and analyze the impact of the particle Reynolds number. The results show that human RBC deformation tends to reach a plateau value in the region of constant extensional rate, the value of which depends on the extension rate. Additionally, we observe that the presence of a sudden expansion downstream of the hyperbolic contraction modifies the spatial distribution of cells and substantially increases the cell free layer (CFL) downstream of the expansion plane similarly to what is seen in other expansion flows. Beyond a certain value of flow rate, there is only a weak effect of inlet flow rates on the enhancement of the downstream CFL. These in vitro experiments show the potential of using microfluidic systems with hyperbolic-shaped microchannels both for the separation of the RBCs from plasma and to assess changes in RBC deformability in physiological and pathological situations for clinical purposes. However, the selection of the geometry and the identification of the most suitable region to evaluate the changes on the RBC deformability under extensional flows are crucial if microfluidics is to be used as an in vitro clinical

  10. Origin and role of fluids involved in the seismic cycle of extensional faults in carbonate rocks

    Science.gov (United States)

    Smeraglia, Luca; Berra, Fabrizio; Billi, Andrea; Boschi, Chiara; Carminati, Eugenio; Doglioni, Carlo

    2016-09-01

    We examine the potentially-seismic right-lateral transtensional-extensional Tre Monti Fault (central Apennines, Italy) with structural and geochemical methods and develop a conceptual evolutionary model of extensional faulting with fluid involvement in shallow (≤3 km depth) faults in carbonate rocks. In the analysed fault zone, multiscale fault rock structures include injection veins, fluidized ultracataclasite layers, and crackle breccias, suggesting that the fault slipped seismically. We reconstructed the relative chronology of these structures through cross-cutting relationship and cathodoluminescence analyses. We then used C- and O-isotope data from different generations of fault-related mineralizations to show a shift from connate (marine-derived) to meteoric fluid circulation during exhumation from 3 to ≤1 km depths and concurrent fluid cooling from ∼68 to barriers within the sedimentary sequence created a semi-closed hydrological system, where prevalently connate fluids circulated within the fault zone at temperatures between 60° and 75 °C. During fault zone exhumation, at depths ≤1 km and temperatures <30 °C, the hydrological circulation became open and meteoric-derived fluids progressively infiltrated and circulated within the fault zone. The role of these fluids during syn-exhumation seismic cycles of the Tre Monti Fault has been substantially passive along the whole fault zone, the fluids being passively redistributed at hydrostatic pressure following co-seismic dilatancy. Only the principal fault has been characterized, locally and transiently, by fluid overpressures. The presence of low-permeability clayey layers in the sedimentary sequence contributed to control the type of fluids infiltrating into the fault zone and possibly their transient overpressures. These results can foster the comprehension of seismic faulting at shallow depths in carbonate rocks of other fold-thrust belts involved in post-collisional seismogenic extensional

  11. Thrust faults and extensional detachment faults in Cretan tectono-stratigraphy: Implications for Middle Miocene extension

    Science.gov (United States)

    Papanikolaou, Dimitrios; Vassilakis, Emmanuel

    2010-06-01

    The revised tectono-stratigraphy of Crete and especially of the "Phyllites-Quartzites" complex demonstrated the distinction of the probable Paleozoic low-medium grade metamorphic rocks of the Arna unit from the underlying Permo-Triassic phyllites and associated carbonate sediments (Trypali facies) of Western Crete unit as well as the overlying Permo-Triassic phyllites and associated sediments of the Tyros/Ravdoucha Beds at the base of the Tripolis unit. The pre-existing mixture of the above tectono-stratigaphic units in a single complex created a number of misinterpretations as far as stratigraphy, metamorphism and interpretation of low angle faults as thrusts or detachments. Especially in cases where the inferred tectonic contact concerns the transition between the Tyros Beds and the base of the Tripolis carbonate platform there is no structural omission and therefore the contact represents a minor disharmonic sliding surface and not a detachment. Based on the revised tectono-stratigraphic analysis the determination of the structural omission for each tectonic contact was possible and several detachments were described for the first time. Footwall rocks of the detachments comprised several tectonic units usually from the lower nappes and hanging wall rocks comprised several tectonic units usually from the upper nappes. The detachment may separate not only metamorphosed units in the footwall (Mani, Western Crete, Arna) from non metamorphosed units in the hanging wall (Tripolis, Pindos and higher nappes) but also all other possible combinations from the Cretan nappe pile. Extension in Crete started in the Middle-Late Miocene with the formation of extensional detachment faults. The reported extensional structures of Oligocene to Early Miocene age do not correspond to crustal extension of Crete but to localized shear zones related to nappe stacking and the exhumation of metamorphic rocks. Extensional detachments in Crete form a tectonic horst through two oppositely

  12. An Extensional Characterization of Lambda-Lifting and Lambda-Dropping

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1999-01-01

    Lambda-lifting and lambda-dropping respectively transform a block-structured functional program into recursive equations and vice versa. Lambda-lifting was developed in the early 80’s, whereas lambda-dropping is more recent. Both are split into an analysis and a transformation. Published work......, however, has only concentrated on the analysis parts. We focus here on the transformation parts and more precisely on their correctness, which appears never to have been proven. To this end, we define extensional versions of lambda-lifting and lambda-dropping and establish their correctness with respect...

  13. An Extensional Characterization of Lambda-Lifting and Lambda-Dropping

    DEFF Research Database (Denmark)

    Danvy, Olivier

    1998-01-01

    Lambda-lifting and lambda-dropping respectively transform a block-structured functional program into recursive equations and vice versa. Lambda-lifting was developed in the early 80’s, whereas lambda-dropping is more recent. Both are split into an analysis and a transformation. Published work......, however, has only concentrated on the analysis parts. We focus here on the transformation parts and more precisely on their correctness, which appears never to have been proven. To this end, we define extensional versions of lambda-lifting and lambda-dropping and establish their correctness with respect...

  14. The dynamics of cylindrical samples in dual wind-up extensional rheometers

    DEFF Research Database (Denmark)

    Yu, Kaijia; Rasmussen, Henrik K.; Marín, Jose Manuel Román

    2011-01-01

    Numerical computations of the extension of circular cylindrical shaped samples in a dual wind-up drum rheometer of Sentmanat extensional rheometer type M. L. Sentmanat, Rheol. Acta 43, 657 (2004); R. Garritano and H. Berting, US Patent No. 7,096,728 (08/29/2006) are presented. These time......-dependent computations are fully three dimensional and based on theoretically ideal configurations. If necking or sample rupture does not occur, the elongation will resemble as ideal uni-axial if the initial sample diameter is decreased sufficiently. An initial diameter larger than 0.5 mm may result in large deviations...

  15. Natural frequencies of members with coupled extensional torsional motion. A physical approach

    Science.gov (United States)

    Williams, F. W.; Howson, W. P.; Banerjee, J. R.

    1993-08-01

    When using exact distributed mass formulations to find the coupled extensional-torsional natural frequencies of members, it is often useful to know a priori any necessary relationships between the natural frequencies of the member for one combination of boundary conditions and those for other combinations. In this contribution such relationships are developed for all combinations of clamped or free boundary conditions for any member with a straight axis, longitudinally invariant properties, coupled extension and torsion, and point symmetry about its midlength. Such members include helical springs, wire ropes, and certain composite beams.

  16. Transient extensional viscosity of polymer melts in the filament stretching rheometer. A. Bach, H. Bastian, M.H. Wagner, H.K. Rasmussen and O. Hassager

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Bach, Anders; Bastian, Heike

    2002-01-01

    In many polymer processing operations, the polymer molecules becomes highly elongated and the extensional viscosity becomes an inportant parameter in estimating properties during and after the process....

  17. Quaternary extensional growth folding beneath Reno, Nevada, imaged by urban seismic profiling

    Science.gov (United States)

    Stephenson, William J.; Frary, Roxy N.; Louie, John; Odum, Jackson K.

    2013-01-01

    We characterize shallow subsurface faulting and basin structure along a transect through heavily urbanized Reno, Nevada, with high‐resolution seismic reflection imaging. The 6.8 km of P‐wave data image the subsurface to approximately 800 m depth and delineate two subbasins and basin uplift that are consistent with structure previously inferred from gravity modeling in this region of the northern Walker Lane. We interpret two primary faults that bound the uplift and deform Quaternary deposits. The dip of Quaternary and Tertiary strata in the western subbasin increases with greater depth to the east, suggesting recurrent fault motion across the westernmost of these faults. Deformation in the Quaternary section of the western subbasin is likely evidence of extensional growth folding at the edge of the Truckee River through Reno. This deformation is north of, and on trend with, previously mapped Quaternary fault strands of the Mt. Rose fault zone. In addition to corroborating the existence of previously inferred intrabasin structure, these data provide evidence for an active extensional Quaternary fault at a previously unknown location within the Truckee Meadows basin that furthers our understanding of both the seismotectonic framework and earthquake hazards in this urbanized region.

  18. Quantification and restoration of extensional deformation along the Western Iberia and Newfoundland rifted margins

    Science.gov (United States)

    Sutra, Emilie; Manatschal, Gianreto; Mohn, Geoffroy; Unternehr, Patrick

    2013-08-01

    Many recent papers describe the structure of the Iberia and Newfoundland rifted margins; however, none of them propose kinematic restorations of the complete rift system to quantify the amount of extension necessary to exhume mantle and initiate seafloor spreading. In our study, we use two pairs of cross sections considered as conjugate lines: one across the Galicia Bank-Flemish Cap and the other across the Southern Iberia Abyssal Plain-Flemish Pass. Both transects have been imaged by reflection- and refraction-seismic methods and have been drilled during Ocean Drilling Program Legs 103, 149, 173, and 210. Drilling penetrated parts of the rift stratigraphy and the underlying basement. The cross sections can therefore be considered as the best-documented conjugate transects across present-day hyperextended, magma-poor rifted margins. The aim of this paper is threefold: (1) provide a detailed description of the crustal architecture of the two conjugate sections, (2) define the extensional structures and their ages, and (3) quantify the amount of strain and strain rate accommodated along these lines. This paper proposes a quantitative description of extension along the Iberia-Newfoundland rift system and discusses the limitations and problems in quantifying extensional deformation along hyperextended rifted margins.

  19. The importance of flow history in mixed shear and extensional flows

    Science.gov (United States)

    Wagner, Caroline; McKinley, Gareth

    2015-11-01

    Many complex fluid flows of experimental and academic interest exhibit mixed kinematics with regions of shear and elongation. Examples include flows through planar hyperbolic contractions in microfluidic devices and through porous media or geometric arrays. Through the introduction of a ``flow-type parameter'' α which varies between 0 in pure shear and 1 in pure elongation, the local velocity fields of all such mixed flows can be concisely characterized. It is tempting to then consider the local stress field and interpret the local state of stress in a complex fluid in terms of shearing or extensional material functions. However, the material response of such fluids exhibit a fading memory of the entire deformation history. We consider a dilute solution of Hookean dumbbells and solve the Oldroyd-B model to obtain analytic expressions for the entire stress field in any arbitrary mixed flow of constant strain rate and flow-type parameter α. We then consider a more complex flow for which the shear rate is constant but the flow-type parameter α varies periodically in time (reminiscent of flow through a periodic array or through repeated contractions and expansions). We show that the flow history and kinematic sequencing (in terms of whether the flow was initialized as shearing or extensional) is extremely important in determining the ensuing stress field and rate of dissipated energy in the flow, and can only be ignored in the limit of infinitely slow flow variations.

  20. Analogue scale modelling of extensional tectonic processes using a large state-of-the-art centrifuge

    Science.gov (United States)

    Park, Heon-Joon; Lee, Changyeol

    2017-04-01

    Analogue scale modelling of extensional tectonic processes such as rifting and basin opening has been numerously conducted. Among the controlling factors, gravitational acceleration (g) on the scale models was regarded as a constant (Earth's gravity) in the most of the analogue model studies, and only a few model studies considered larger gravitational acceleration by using a centrifuge (an apparatus generating large centrifugal force by rotating the model at a high speed). Although analogue models using a centrifuge allow large scale-down and accelerated deformation that is derived by density differences such as salt diapir, the possible model size is mostly limited up to 10 cm. A state-of-the-art centrifuge installed at the KOCED Geotechnical Centrifuge Testing Center, Korea Advanced Institute of Science and Technology (KAIST) allows a large surface area of the scale-models up to 70 by 70 cm under the maximum capacity of 240 g-tons. Using the centrifuge, we will conduct analogue scale modelling of the extensional tectonic processes such as opening of the back-arc basin. Acknowledgement This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (grant number 2014R1A6A3A04056405).

  1. Acoustic isolation of a monopole logging while drilling tool by combining natural stopbands of pipe extensional waves

    Science.gov (United States)

    Su, Yuan-Da; Tang, Xiao-Ming; Xu, Song; Zhuang, Chun-Xi

    2015-07-01

    For extensional wave propagation along a cylindrical pipe, there exists a natural stopband in the frequency range between the first and second modes. This study explores the feasibility and practicality of building a drill collar acoustic extensional-wave isolator by combining the stopbands of pipes of different thicknesses. Numerical modelling shows that this is indeed possible and a stopband of designated width can be obtained using an optimization procedure. Laboratory measurement on an optimized design further verified this concept. The result provides a viable approach for the acoustic isolation design of a logging while drilling acoustic tool.

  2. Extensional flow of nematic liquid crystal with an applied electric field

    KAUST Repository

    CUMMINGS, L. J.

    2013-10-17

    Systematic asymptotic methods are used to formulate a model for the extensional flow of a thin sheet of nematic liquid crystal. With no external body forces applied, the model is found to be equivalent to the so-called Trouton model for Newtonian sheets (and fibres), albeit with a modified \\'Trouton ratio\\'. However, with a symmetry-breaking electric field gradient applied, behaviour deviates from the Newtonian case, and the sheet can undergo finite-time breakup if a suitable destabilizing field is applied. Some simple exact solutions are presented to illustrate the results in certain idealized limits, as well as sample numerical results to the full model equations. Copyright © Cambridge University Press 2013.

  3. New approach to date the extensional tectonics in the Betic Chain (Spain)

    Science.gov (United States)

    Julián Esteban, José; María Tubía, José; Cuevas, Julia; Seward, Diane; Larionov, Alexander; Sergeev, Sergey; Navarro-Vilá, Francisco

    2013-04-01

    The Betic Cordilleras, in southern Spain, represent a good example of a collisional orogen disaggregated by extensional collapse in a convergent setting during the Miocene. The Alpujarride and Malaguide Complexes, in the Internal Zone, are bounded by an extensional detachment, previously interpreted as a thrust-nappe. In the western Betics, the Malaguide Complex overlies the Los Reales nappe (one of the tectonic slices that conforms the Alpujarride Complex) and although their boundary is characterized as a brittle-ductile extensional detachment, little is known about its age of movement. In order to constraint the age of the detachment, two dolerite dykes cut by the boundary were dated by U-Pb SHRIMP on zircons along with nine samples, from the lowest to the upper structural levels of the Malaguide Complex, by zircon fission-track analysis (ZFT). Zircons separated from dolerite dykes display rounded or eroded edges bounded by light or dark luminescent rims. Zircons cores with igneous appearance (euhedral, oscillatory zoning, high Th/U content) yield 206Pb/238U ages between 1799 and 264 Ma, which cannot be correlated with dolerite dyke intrusion, as similar dykes appear within Middle-Upper Triassic pelites in other Alpujarride sections. Otherwise, the external rims yield ages between 1187 to 28 Ma. Four of the youngest analysed zircon rims show Th/U ratios consistent with a metamorphic origin. These zircons define a mixing line intersecting the Concordia at 20.9 ± 9 (2σ), that agrees with the age of the thermal Alpine metamorphism. Two of the youngest rims display high Th/U contents, common in igneous zircons. They give concordant ages of 33.1 ± 1.5 (2σ) and 39.0 ± 2.5 (2σ) Ma. However, the youngest is the only one that has geological meaning, as similar ages have been reported using different geochronological systems. Therefore, it could be considered as the age of dolerite dyke intrusion. The ZFT samples yield ages between 18.6 ± 1.8 (2σ) and 25.8 ± 3

  4. Thin-walled composite beams under bending, torsional, and extensional loads

    Science.gov (United States)

    Chandra, Ramesh; Stemple, Alan D.; Chopra, Inderjit

    1990-01-01

    Symmetric and antisymmetric layup graphite-epoxy composite beams with thin-walled rectangular cross sections are fabricated using an autoclave molding technique and tested under bending, torsional, and extensional loads. The bending slope and elastic twist at a station are measured using an optical system, and the results correlated with predicted values from a simple beam analysis as well as a refined finite element analysis. A symmetric ply layup results in bending-twist coupling whereas an antisymmetric layup causes extension-twist coupling. Simple analytical results with plane-stress assumption agree better with measured data as well as finite element predictions than with plane-strain assumption. For symmetric layup beams, the bending-induced twist and torsion-induced bending slope are predicted satisfactorily using simple analytical solution. Correlations with measured data, however, are generally improved using a finite element solution. For antisymmetric beams, axial force-induced twist is predicted satisfactorily by both methods.

  5. Extensional Seismogenic Stress and Tectonic Movement on the Central Region of the Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Jiren Xu

    2009-01-01

    Full Text Available Various earthquake fault types, mechanism solutions and stress fields, as well as GPS and geothermal data are analyzed for the study of the crustal movements on the Tibetan plateau and their tectonic implications. The results show that a lot of the normal faulting type-event concentrated at altitudes greater than 4000 m on the central Tibetan plateau. The altitudes concentrating normal faulting type-events can be zoned two parts: the western part, the Lhasa block, and the eastern part, the Qiangtang-Changdu region. The azimuths of T-axes are in a general E-W direction in the Lhasa block and NW-SE or NNW-SSE in the Qiangtang-Changdu region at the altitudes of the Tibetan plateau. The tensional stresses in E-W direction and NW-SE direction predominate normal faulting earthquake occurrence in the Lhasa block and the Qiangtang-Changdu region, respectively. The slipping displacements of the normal-faulting-type events have great components in near E-W direction and NW-SE direction in the Lhasa block and the Qiangtang-Changdu region, respectively. The extensions are probably an eastward or southeastward extensional motion, being mainly tectonic activity phenomena in the plateau altitudes. The extensional motions due to normal-fault earthquakes are important tectonic activity regimes on the high altitudes of the plateau. The easterly crustal extensions on the plateau are attributable to the gravitational collapse of the high plateau and eastward extrusion of hotter mantle materials beneath the eastern boundary of the plateau. Numbers of thrust-fault and strike-slip-fault earthquakes with strong compressive stress in a general NNE-SSW direction occur on the edges of the plateau.

  6. Suppositions, Extensionality, and Conditionals: A Critique of the Mental Model Theory of Johnson-Laird and Byrne (2002)

    Science.gov (United States)

    Evans, Jonathan St. B. T.; Over, David E.; Handley, Simon J.

    2005-01-01

    P. N. Johnson-Laird and R. M. J. Byrne proposed an influential theory of conditionals in which mental models represent logical possibilities and inferences are drawn from the extensions of possibilities that are used to represent conditionals. In this article, the authors argue that the extensional semantics underlying this theory is equivalent to…

  7. Discrete element modeling of Martian pit crater formation in response to extensional fracturing and dilational normal faulting

    Science.gov (United States)

    Smart, Kevin J.; Wyrick, Danielle Y.; Ferrill, David A.

    2011-04-01

    Pit craters, circular to elliptical depressions that lack a raised rim or ejecta deposits, are common on the surface of Mars. Similar structures are also found on Earth, Venus, the Moon, and smaller planetary bodies, including some asteroids. While it is generally accepted that these pits form in response to material drainage into a subsurface void space, the primary mechanism(s) responsible for creating the void is a subject of debate. Previously proposed mechanisms include collapse into lave tubes, dike injection, extensional fracturing, and dilational normal faulting. In this study, we employ two-dimensional discrete element models to assess both extensional fracturing and dilational normal faulting as mechanisms for forming pit craters. We also examine the effect of mechanical stratigraphy (alternating strong and weak layers) and variation in regolith thickness on pit morphology. Our simulations indicate that both extensional fracturing and dilational normal faulting are viable mechanisms. Both mechanisms lead to generally convex (steepening downward) slope profiles; extensional fracturing results in generally symmetric pits, whereas dilational normal faulting produces strongly asymmetric geometries. Pit width is established early, whereas pit depth increases later in the deformation history. Inclusion of mechanical stratigraphy results in wider and deeper pits, particularly for the dilational normal faulting, and the presence of strong near-surface layers leads to pits with distinct edges as observed on Mars. The modeling results suggest that a thicker regolith leads to wider but shallower pits that are less distinct and may be more difficult to detect in areas of thick regolith.

  8. Late Miocene extensional systems in northern Tunisia and their relation with SE directed delamination of the African subcontinental mantle lithosphere

    Science.gov (United States)

    Booth-Rea, Guillermo; Gaidi, Seif; Melki, Fetheddine; Pérez-Peña, Vicente; Marzougui, Wissem; Azañón, Jose Miguel; Galve, Jorge Pedro

    2017-04-01

    Recent work has proposed the delamination of the subcontinental mantle lithosphere under northern Tunisia during the late Miocene. This process is required to explain the present location of the Tunisian segment of the African slab, imaged by seismic tomography, hanging under the Gulf of Gabes to the south of Tunisia. Thus, having retreated towards the SE several hundred km from its original position under the Tellian-Atlas nappe contact that crops out along the north of Tunisia. However, no tectonic structures have been described which could be related to this mechanism of lithospheric mantle peeling. Here we describe for the first time extensional fault systems in northern Tunisia that strongly thinned the Tellian nappes, exhuming rocks from the Tunisian Atlas in the core of folded extensional detachments. Two normal fault systems with sub-orthogonal extensional transport occur. These were active during the late Miocene associated to the extrusion of 13 Ma granodiorite and 9 Ma rhyodacite in the footwall of the Nefza detachment. We have differentiated an extensional system formed by low-angle normal faults with NE- and SW-directed transport cutting through the Early to Middle Miocene Tellian nappen stack and a later system of low and high-angle normal faults that cuts down into the underlying Tunisian Atlas units with SE-directed transport, which root in the Nefza detachment. Both normal fault systems have been later folded and cut by thrusts during Plio-Quaternary NW-SE directed compression. These findings change the interpretation of the tectonic evolution of Tunisia that has always been framed in a transpressive to compressive setting, manifesting the extensional effects of Late Miocene lithospheric mantle delamination under northern Tunisia.

  9. From orogenic buildup to extensional unroofing: the evolution of the Adria - Europe collisional zone in the Medvednica Mountains of Croatia

    Science.gov (United States)

    Beniest, Anouk; van Gelder, Inge; Matenco, Liviu; Willingshofer, Ernst; Gruic, Andrea; Tomljenovic, Bruno

    2013-04-01

    Quantifying the kinematics of the Miocene extension in the Pannonian Basin is of critical importance for understanding the evolution of Adria-Europe collision in particular in the transitional zone from the Alps (Adria the upper plate) to the Dinarides (Adria the lower plate). Recent studies have demonstrated that large-scale extensional unroofing and core-complex formation affected the Europe-Adria contact in the Dinarides during Miocene times. The relationship between this extensional exhumation of Adriatic units and the roughly coeval Miocene extension affecting the Alpine-derived units during their E-ward extrusion into the intra-Carpathians ALCAPA block and the formation of the Pannonian basin is still unknown. One key area situated in the transitional zone is the Medvednica Mountains of Croatia, an area that benefits from already existing and extensive petrological and structural studies. The area of the Medvednica Mountains has been targeted by the means of a field kinematic analysis complemented by low-temperature thermochronology, metamorphic petrology and sedimentological observations. The results demonstrate that two units, reflecting distinct Adriatic paleogeographical positions, make up the structural geometry of the mountains. The upper unit contains Paleozoic mostly fine clastic sequence metamorphosed in sub-greenschist facies, overlain by a proximal Adriatic facies consisting of Triassic shallow water carbonates. The lower unit is made up by a volcanic sequence overlain by gradual deepening Triassic carbonates metamorphosed in greenschist facies that bears a strong resemblance to the Triassic break-up volcanism and subsequent sedimentation affecting the distal Adriatic units observed elsewhere in the Jadar-Kopaonik unit of the Dinarides. The strong contrast between the Middle-Upper Triassic facies suggests large scale thrusting during Cretaceous nappe stacking. Subsequently, the studied area has been affected by significant extensional deformation

  10. Droplet Deformation in an Extensional Flow: The Role of Surfactant Physical Chemistry

    Science.gov (United States)

    Stebe, Kathleen J.

    1996-01-01

    Surfactant-induced Marangoni effects strongly alter the stresses exerted along fluid particle interfaces. In low gravity processes, these stresses can dictate the system behavior. The dependence of Marangoni effects on surfactant physical chemistry is not understood, severely impacting our ability to predict and control fluid particle flows. A droplet in an extensional flow allows the controlled study of stretching and deforming interfaces. The deformations of the drop allow both Marangoni stresses, which resist tangential shear, and Marangoni elasticities, which resist surface dilatation, to develop. This flow presents an ideal model system for studying these effects. Prior surfactant-related work in this flow considered a linear dependence of the surface tension on the surface concentration, valid only at dilute surface concentrations, or a non-linear framework at concentrations sufficiently dilute that the linear approximation was valid. The linear framework becomes inadequate for several reasons. The finite dimensions of surfactant molecules must be taken into account with a model that includes surfaces saturation. Nonideal interactions between adsorbed surfactant molecules alter the partitioning of surfactant between the bulk and the interface, the dynamics of surfactant adsorptive/desorptive exchange, and the sensitivity of the surface tension to adsorbed surfactant. For example, cohesion between hydrocarbon chains favors strong adsorption. Cohesion also slows the rate of desorption from interfaces, and decreases the sensitivity of the surface tension to adsorbed surfactant. Strong cohesive interactions result in first order surface phase changes with a plateau in the surface tension vs surface concentration. Within this surface concentration range, the surface tension is decoupled from surface concentration gradients. We are engaged in the study of the role of surfactant physical chemistry in determining the Marangoni stresses on a drop in an extensional

  11. Transient overshoot extensional rheology of long-chain branched polyethylenes: Experimental and numerical comparisons between filament stretching and cross-slot flow

    DEFF Research Database (Denmark)

    Hoyle, D.M.; Huang, Qian; Auhl, D.

    2013-01-01

    the imposed strain rate on a filament, allowing Hencky strains of around 7 to be reached. The cross-slot extensional rheometer uses optical birefringence patterns to determine the steady-state extensional viscosity from planar stagnation point flow. The two methods probe different strain-rate regimes...... and in this paper we demonstrate the agreement when the operating regimes overlap and explore the steady-state extensional viscosity in the full strain-rate regime that these two complimentary techniques offer. For long-chain branched materials, the cross-slot birefringence images show a double cusp pattern around...

  12. Salt diapirs in the Dead Sea basin and their relationship to Quaternary extensional tectonics

    Science.gov (United States)

    Al-Zoubi, A.; ten Brink, U.S.

    2001-01-01

    Regional extension of a brittle overburden and underlying salt causes differential loading that is thought to initiate the rise of reactive diapirs below and through regions of thin overburden. We present a modern example of a large salt diapir in the Dead Sea pull-apart basin, the Lisan diapir, which we believe was formed during the Quaternary due to basin transtension and subsidence. Using newly released seismic data that are correlated to several deep wells, we determine the size of the diapir to be 13 x 10 km. its maximum depth 7.2 km. and its roof 125 m below the surface. From seismic stratigraphy, we infer that the diapir started rising during the early to middle Pleistocene as this section of the basin underwater rapid subsidence and significant extension of the overburden. During the middle to late Pleistocene, the diapir pierced through the extensionally thinned overburden, as indicated by rim synclines, which attest to rapid salt withdrawal from the surrounding regions. Slight positive topography above the diapir and shallow folded horizons indicate that it is still rising intermittently. The smaller Sedom diapir, exposed along the western bounding fault of the basin is presently rising and forms a 200 m-high ridge. Its initiation is explained by localized E-W extension due monoclinal draping over the edge of a rapidly subsiding basin during the early to middle Pleistocene, and its continued rise by lateral squeezing due to continued rotation of the Amazyahu diagonal fault. 

  13. Marangoni Effects of a Drop in an Extensional Flow: The Role of Surfactant Physical Chemistry

    Science.gov (United States)

    Stebe, Kathleen J.; Balasubramaniam, R. (Technical Monitor)

    2002-01-01

    While the changes in stresses caused by surfactant adsorption on non-deforming interfaces have been fairly well established, prior to this work, there were few studies addressing how surfactants alter stresses on strongly deforming interfaces. We chose the model problem of a drop in a uniaxial extensional flow to study these stress conditions To model surfactant effects at fluid interfaces, a proper description of the dependence of the surface tension on surface concentration, the surface equation of state, is required. We have adopted a surface equation of state that accounts for the maximum coverage limit; that is, because surfactants have a finite cross sectional area, there is an upper bound to the amount of surfactant that can adsorb in a monolayer. The surface tension reduces strongly only when this maximum coverage is approached. Since the Marangoni stresses go as the derivative of the surface equation of state times the surface concentration gradient, the non-linear equation of state determines both the effect of surfactants in the normal stress jump, (which is balanced by the product of the mean curvature of the interface times the surface tension), and the tangential stress jump, which is balanced by Marangoni stresses. First, the effects of surface coverage and intermolecular interactions among surfactants which drive aggregation of surfactants in the interface were studied. (see Pawar and Stebe, Physics of Fluids).

  14. Experimental Methods to Observe Asymmetric Instability of Intermediate-Reduced-Volume Vesicles in Extensional Flow

    Science.gov (United States)

    Dahl, Joanna; Narsimhan, Vivek; Gouveia, Bernardo; Kumar, Sanjay; Shaqfeh, Eric; Muller, Susan

    2014-11-01

    Vesicles provide an attractive model system to understand the deformation of living cells in response to mechanical forces. These enclosed lipid bilayer membranes are suitable for complementary theoretical and experimental analysis. A recent study (Narsimhan et al., J. Fluid Mech. 750, 144 (2014)) predicted that intermediate-aspect-ratio vesicles break up asymmetrically in extensional flow. Upon infinitesimal perturbation to its shape, the vesicle stretches into an asymmetric dumbbell. In this work, we present preliminary results from cross-slot microfluidic experiments observing this instability. The onset of breakup depends on two non-dimensional parameters: reduced volume (vesicle asphericity) and capillary number (ratio of viscous to bending forces). We will present strategies for accurately measuring these quantities in order to plot a stability diagram. Specifically, we will describe our synthesis of floppy, intermediate-reduced-volume vesicles and our measurement of their bending moduli by analyzing membrane thermal fluctuations. We will discuss coupling particle-image velocimetry (PIV) with cross-slot trapping of vesicles to ensure that breakup occurs at the stagnation point. A preliminary phase diagram for asymmetric breakup will be reported.

  15. Buckling of thin viscous sheets with inhomogenous viscosity under extensional flows

    Science.gov (United States)

    Srinivasan, Siddarth; Wei, Zhiyan; Mahadevan, L.

    2016-11-01

    We investigate the dynamics, shape and stability of a thin viscous sheet subjected to an extensional flow under an imposed non-uniform temperature field. Using finite element simulations, we first solve for the stretching flow to determine the pre-buckling sheet thickness and in-plane flow velocities. Next, we use this solution as the base state and solve the linearized partial differential equation governing the out-of-plane deformation of the mid-surface as a function of two dimensionless operating parameters: the normalized stretching ratio α and a dimensionless width of the heating zone β. We show the sheet can become unstable via a buckling instability driven by the development of localized compressive stresses, and determine the global shape and growth rates of the most unstable mode. The growth rate is shown to exhibit a transition from stationary to oscillatory modes in region upstream of the heating zone. Finally, we investigate the effect of surface tension and present an operating diagram that indicates regions of the parameter space that minimizes or entirely suppresses the instability while achieving desired outlet sheet thickness. Therefore, our work is directly relevant to various industrial processes including the glass redraw & float-glass method.

  16. A numerical approach to thermal history modelling in an extensional basin

    Science.gov (United States)

    Tunwal, Mohit; Mulchrone, Kieran; Meere, Patrick

    2017-04-01

    Temperature plays an important role in many geological phenomena. In sedimentary basins, maturation of hydrocarbon source rocks depends on the temperature history after deposition. Sedimentation rate, geothermal gradient and duration of sedimentation are therefore key parameters controlling the thermal evolution. The McKenzie model is a widely accepted model for extensional basin formation which can be used for estimating post-rift subsidence, rate of sedimentation and basal heat flow. In this work, a numerical model in 1D has been implemented based on McKenzie's model and allows for the estimation of the thermal evolution of post-rift sediments and the rate of subsidence. The finite difference method is used to solve the heat equation in the sediments, crust and upper mantle. At each time step, subsidence due to thermal relaxation is calculated and added to the system. In this way the generalised moving boundary thermal diffusion problem is solved. Heat generated due to radioactivity may also be taken into account. The numerical model when compared to the McKenzie model gives significantly lower thermal subsidence estimates. Final thermal subsidence for the two models are compared with respect to the stretching factor. This model shows that significantly higher stretching is required to achieve the same level of thermal subsidence when compared to the McKenzie model. For example in the McKenzie model a 5 km of thermal subsidence is achieved with 280% stretching whereas this model requires 450% stretching.

  17. On the evolution and breakup of slender drops in an extensional flow

    Science.gov (United States)

    Favelukis, M.; Lavrenteva, O. M.; Nir, A.

    2012-04-01

    The evolution of the shape of an elongated drop embedded in an extensional flow is studied in the framework of slender body theory. The external flow has a weak but not neglected inertia. The problem is governed by three dimensionless parameters: the capillary number, the external Reynolds number, and the viscosity ratio between the drop and the external fluid, and exhibits a multiplicity of stationary shapes with only one being stable. Evolution of the drop surface from initial shapes was studied when the flow intensity was either kept constant or subjected to a sudden change. It was shown that the dynamics of the shape evolution can lead to a breakup of the drop or to a stable stationary shape. Two modes of breakup are revealed: an indefinite elongation and a center pinching mode. The former appears when the viscous forces dominate the inertia effects, with the typical case being that of a creeping flow. The latter breakup mode takes over in the presence of inertia when the drop viscosity diminishes with the extreme example being that of an inviscid drop.

  18. Energy trapping of thickness-extensional modes in thin film bulk acoustic wave filters

    Directory of Open Access Journals (Sweden)

    Zinan Zhao

    2016-01-01

    Full Text Available This paper presents the thickness-extensional vibration of a rectangular piezoelectric thin film bulk acoustic wave filter with two pairs of electrodes symmetrically deposited on the center of the zinc oxide film. The two-dimensional scalar differential equations which were first derived to describe in-plane vibration distribution by Tiersten and Stevens are employed. The Ritz method with trigonometric functions as basis functions is used based on a variational formulation developed in our previous paper. Free vibration resonant frequencies and corresponding modes are obtained. The modes may separate into symmetric and antisymmetric ones for such a structurally symmetric filter. Trapped modes with vibrations mainly under the driving electrodes are exhibited. The six corner-type regions of the filter neglected by Tiersten and Stevens for an approximation are taken into account in our analysis. Results show that their approximation can lead to an inaccuracy on the order of dozens of ppm for the fundamental mode, which is quite significant in filter operation and application.

  19. Extensional tectonics and sedimentary response of the Early–Middle Cambrian passive continental margin, Tarim Basin, Northwest China

    Directory of Open Access Journals (Sweden)

    Zhiqian Gao

    2012-09-01

    Full Text Available The fact that several half-grabens and normal faults developed in the Lower–Middle Cambrian of Tazhong (central Tarim Basin and Bachu areas in Tarim Basin, northwest China, indicates that Tarim Basin was under extensional tectonic setting at this time. The half-grabens occur within a linear zone and the normal faults are arranged in en echelon patterns with gradually increasing displacement eastward. Extensional tectonics resulted in the formation of a passive continental margin in the southwest and a cratonic margin depression in the east, and most importantly, influenced the development of a three-pronged rift in the northeast margin of the Tarim Basin. The fault system controlled the development of platform – slope – bathyal facies sedimentation of mainly limestone-dolomite-gypsum rock-saline rock-red beds in the half-grabens. The NW-SE trending half-grabens reflect the distribution of buried basement faults.

  20. Extensional flow of liquid jets formed by bubble collapse in oils under cavitation-generated pressure waves

    Energy Technology Data Exchange (ETDEWEB)

    Barrow, M.S.; Brown, S.W.J.; Williams, P.R. [Department of Chemical and Biological Process Engineering, University of Wales Swansea, Singleton Park, SA2 8PP, Swansea (United Kingdom)

    2004-03-01

    We report a study of liquid jets which are formed by bubble collapse under cavitation-generated pressure waves. The results obtained for jets formed from samples of a multigrade motor oil provide the first evidence that such jets experience a significant degree of extensional deformation, at high rates of extension. The results support the conclusion that the reduced velocity and final length of such jets, relative to their Newtonian counterparts, is due to an increased resistance to extensional flow. Insofar as the multigrade oils studied here are made viscoelastic by polymer additives and evidently possess significant levels of resistance to extension, the results provide evidence in support of a mitigating effect of viscoelasticity on a cavitation damage mechanism, as mooted by Berker et al. (J Non Newton Fluid Mech 56:333, 1995). (orig.)

  1. Extensional flow of liquid jets formed by bubble collapse in oils under cavitation-generated pressure waves

    Science.gov (United States)

    Barrow, M. S.; Brown, S. W. J.; Williams, P. R.

    We report a study of liquid jets which are formed by bubble collapse under cavitation-generated pressure waves. The results obtained for jets formed from samples of a multigrade motor oil provide the first evidence that such jets experience a significant degree of extensional deformation, at high rates of extension. The results support the conclusion that the reduced velocity and final length of such jets, relative to their Newtonian counterparts, is due to an increased resistance to extensional flow. Insofar as the multigrade oils studied here are made viscoelastic by polymer additives and evidently possess significant levels of resistance to extension, the results provide evidence in support of a mitigating effect of viscoelasticity on a cavitation damage mechanism, as mooted by Berker et al. (J Non Newton Fluid Mech 56:333, 1995).

  2. From nappe stacking to extensional detachments at the contact between the Carpathians and Dinarides - The Jastrebac Mountains of Central Serbia

    Science.gov (United States)

    Erak, Dalibor; Matenco, Liviu; Toljić, Marinko; Stojadinović, Uroš; Andriessen, Paul A. M.; Willingshofer, Ernst; Ducea, Mihai N.

    2017-07-01

    Reactivation of inherited nappe contacts is a common process in orogenic areas affected by back-arc extension. The amount of back-arc extension is often variable along the orogenic strike, owing to the evolution of arcuated mountain chains during stages of rapid slab retreat. This evolution creates low rates of extension near rotation poles, where kinematics and interplay with the pre-existing orogenic structure are less understood. The amount of Miocene extension recorded by the Pannonian Basin of Central Europe decreases SE-wards along the inherited Cretaceous - Paleogene contact between the Dinarides and Carpathian Mountains. Our study combines kinematic data obtained from field and micro-structural observations assisted with fission track thermochronological analysis and U-Pb zircon dating to demonstrate a complex poly-phase evolution in the key area of the Jastrebac Mountains of Serbia. A first event of Late Cretaceous exhumation was followed by latest Cretaceous - Eocene thrusting and magmatism related to a continental collision that sutured the accretionary wedge containing contractional trench turbidites. The suture zone was subsequently reactivated and exhumed by a newly observed Miocene extensional detachment that lasted longer in the Jastrebac Mountains when compared with similar structures situated elsewhere in the same structural position. Such extensional zones situated near the pole of extensional-driven rotation favour late stage truncations and migration of extension in a hanging-wall direction, while directions of tectonic transport show significant differences in short distances across the strike of major structures.

  3. Estrategias de gestión del valor de marca de las cabeceras de prensa españolas a través de sus extensiones digitales

    National Research Council Canada - National Science Library

    Victoria-Mas, María; Lacasa-Mas, Iván

    2017-01-01

    ... una minoría de empresas informativas tradicionales ha desarrollado estrategias de gestión de ese valor. Cuando las extensiones digitales no son coherentes con las marcas madre, pueden diluir su imagen y acabar siendo contraproducentes...

  4. The Tastil batholith (Cordillera Oriental, Argentina): a case of lower Cambrian extensional-related magmatism in the border of Gondwana.

    Science.gov (United States)

    Hongn, F.; Tubía, J. M.; Aranguren, A.; Mon, R.

    2003-04-01

    The Tastil batholith composed of gray granodiorite, red granite and dacite porphiry, intrudes into weakly metamorphosed turbidites (usually included in the Puncoviscana Formation) and into Cambrian shelf sandstones belonging to the Lower-Middle Cambrian Mesón Group deposited in an intracontinental extensional basin. Tremadocian fossiliferous conglomerates overlying the sandstones of the Mesón Group incorporate red granite pebbles in the Angosto de la Quesera section, the classical section for interpreting the stratigraphic relationships of the Tastil batholith. U-Pb zircon ages from a dacite porphiry (526 Ma) and red granite (517 Ma) are consistent with such field relationships. This new view of the Tastil batholith implies that the previous interpretations of the basement, based on the supposed unconformity between the Mesón Group and the underlying red granite, and hence including the Tastil batholith in the basement, can not longer be sustained. The batholith emplacement is not related with the shortening happened during the late evolution of the Puncoviscana Formation (Pampean cycle) as always was interpreted, but with the extensional tectonics responsible for the development of the Mesón Group basin (Famatinian cycle). Along central and northern Argentina, the basement records a wide spectrum of sedimentary, deformational, magmatic and metamorphic processes occurred at different crustal levels during the Latest Neoproterozoic and the Cambrian. In this regard, the deposition of the Mesón Group and the intrusion of the Tastil batholith within the Cordillera Oriental can be correlated with the magmatism and the high-T/low-P metamorphism developed, at deeper levels, 530 to 500 Ma ago within the basement of the Puna and Sierras Pampeanas. In the same way, the sedimentation and igneous processes documented at shallower levels in the Sierras Pampeanas took place in this extensional tectonic scenario. The available data point to an overall extensional tectonics

  5. The rift architecture and extensional tectonics of the South China Sea

    Science.gov (United States)

    Cameselle, Alejandra L.; Ranero, César R.; Barckhausen, Udo; Franke, Dieter

    2016-04-01

    Non-volcanic rifted continental margins are classically described as the product of lithospheric stretching and breakup leading to mantle exhumation, and subsequent seafloor spreading. However, recent studies question this model and indicate a wider range of structural evolutions, that challenge the existing model (e.g. Australia-Antarctic Rift System (Direen et al. 2007, 2011); the Tyrrhenian basin (Prada et al., 2014) or the South China Sea (Cameselle et al. 2015)). Rifting in the South China Sea developed from a series of extensional events, from early Eocene to Late Oligocene, resulting in a V-shape oceanic basin affected by the occurrence of several spreading centers, ridges, transform faults and post-spreading volcanism. In recent years, this marginal basin - the largest in East Asia - has increasingly become one of the key sites for the study of rifting and continental break-up. Its relative small size - compared to many classic, Atlantic-type continental margin settings - allows to easily match conjugated rifted margins and its relative youth promotes the preservation of its original nature. To examine the rifting evolution of the South China Sea, we have reprocessed with modern algorithms multichannel seismic profiles acquired during Sonne49 and BGR84 cruises across the three major subbasins: NW, SW and East subbasins. State-of-the-art of processing techniques have been used to increase the signal to noise ratio, including Tau-P and Wiener predictive deconvolution, multiple attenuation by both radon filtering and wave-equation-based surface-related multiple elimination (SRME) and time migration. To complement seismic interpretation, available vintage multichannel seismic data have been reprocessed with a post-stack flow, including Wiener deconvolution, FK-filtering, space and time variant band-pass filter and time migration. The improving quality of the seismic images shows a range of features including post-rift and syn-rift sediments, the structure of

  6. Analysis of Neogene deformation between Beaver, Utah and Barstow, California: Suggestions for altering the extensional paradigm

    Science.gov (United States)

    Anderson, R. Ernest; Beard, Sue; Mankinen, Edward A.; Hillhouse, John W.

    2013-01-01

    For more than two decades, the paradigm of large-magnitude (~250 km), northwest-directed (~N70°W) Neogene extensional lengthening between the Colorado Plateau and Sierra Nevada at the approximate latitude of Las Vegas has remained largely unchallenged, as has the notion that the strain integrates with coeval strains in adjacent regions and with plate-boundary strain. The paradigm depends on poorly constrained interconnectedness of extreme-case lengthening estimated at scattered localities within the region. Here we evaluate the soundness of the inferred strain interconnectedness over an area reaching 600 km southwest from Beaver, Utah, to Barstow, California, and conclude that lengthening is overestimated in most areas and, even if the estimates are valid, lengthening is not interconnected in a way that allows for published versions of province-wide summations.We summarize Neogene strike slip in 13 areas distributed from central Utah to Lake Mead. In general, left-sense shear and associated structures define a broad zone of translation approximately parallel to the eastern boundary of the Basin and Range against the Colorado Plateau, a zone we refer to as the Hingeline shear zone. Areas of steep-axis rotation (ranging to 2500 km2) record N-S shortening rather than unevenly distributed lengthening. In most cases, the rotational shortening and extension-parallel folds and thrusts are coupled to, or absorb, strike slip, thus providing valuable insight into how the discontinuous strike-slip faults are simply parts of a broad zone of continuous strain. The discontinuous nature of strike slip and the complex mixture of extensional, contractional, and steep-axis rotational structures in the Hingeline shear zone are similar to those in the Walker Lane belt in the west part of the Basin and Range, and, together, the two record southward displacement of the central and northern Basin and Range relative to the adjacent Colorado Plateau. Understanding this province

  7. Hydrothermal dolomitization of basinal deposits controlled by a synsedimentary fault system in Triassic extensional setting, Hungary

    Science.gov (United States)

    Hips, Kinga; Haas, János; Győri, Orsolya

    2016-06-01

    Dolomitization of relatively thick carbonate successions occurs via an effective fluid circulation mechanism, since the replacement process requires a large amount of Mg-rich fluid interacting with the CaCO3 precursor. In the western end of the Neotethys, fault-controlled extensional basins developed during the Late Triassic spreading stage. In the Buda Hills and Danube-East blocks, distinct parts of silica and organic matter-rich slope and basinal deposits are dolomitized. Petrographic, geochemical, and fluid inclusion data distinguished two dolomite types: (1) finely to medium crystalline and (2) medium to coarsely crystalline. They commonly co-occur and show a gradual transition. Both exhibit breccia fabric under microscope. Dolomite texture reveals that the breccia fabric is not inherited from the precursor carbonates but was formed during the dolomitization process and under the influence of repeated seismic shocks. Dolomitization within the slope and basinal succession as well as within the breccia zones of the underlying basement block is interpreted as being related to fluid originated from the detachment zone and channelled along synsedimentary normal faults. The proposed conceptual model of dolomitization suggests that pervasive dolomitization occurred not only within and near the fault zones. Permeable beds have channelled the fluid towards the basin centre where the fluid was capable of partial dolomitization. The fluid inclusion data, compared with vitrinite reflectance and maturation data of organic matter, suggest that the ascending fluid was likely hydrothermal which cooled down via mixing with marine-derived pore fluid. Thermal gradient is considered as a potential driving force for fluid flow.

  8. Single-molecule sequence detection via microfluidic planar extensional flow at a stagnation point.

    Science.gov (United States)

    Dylla-Spears, Rebecca; Townsend, Jacqueline E; Jen-Jacobson, Linda; Sohn, Lydia L; Muller, Susan J

    2010-06-21

    We demonstrate the use of a microfluidic stagnation point flow to trap and extend single molecules of double-stranded (ds) genomic DNA for detection of target sequences along the DNA backbone. Mutant EcoRI-based fluorescent markers are bound sequence-specifically to fluorescently labeled ds lambda-DNA. The marker-DNA complexes are introduced into a microfluidic cross slot consisting of flow channels that intersect at ninety degrees. Buffered solution containing the marker-DNA complexes flows in one channel of the cross slot, pure buffer flows in the opposing channel at the same flow rate, and fluid exits the two channels at ninety degrees from the inlet channels. This creates a stagnation point at the center of a planar extensional flow, where marker-DNA complexes may be trapped and elongated along the outflow axis. The degree of elongation can be controlled using the flow strength (i.e., a non-dimensional flow rate) in the device. Both the DNA backbone and the markers bound along the stretched DNA are observed directly using fluorescence microscopy, and the location of the markers along the DNA backbone is measured. We find that our method permits detection of each of the five expected target site positions to within 1.5 kb with standard deviations of <1.5 kb. We compare the method's precision and accuracy at molecular extensions of 68% and 88% of the contour length to binding distributions from similar data obtained via molecular combing. We also provide evidence that increased mixing of the sample during binding of the marker to the DNA improves binding to internal target sequences of dsDNA, presumably by extending the DNA and making the internal binding sites more accessible.

  9. Carbonate platform development in a Paleoproterozoic extensional basin, Vempalle Formation, Cuddapah Basin, India

    Science.gov (United States)

    Chakrabarti, Gopal; Shome, Debasish; Kumar, Subhasish; Stephens, George M.; Kah, Linda C.

    2014-09-01

    Sedimentological investigation of the late Paleoproterozoic (Orosirian) Vempalle Formation of the Cuddapah Basin, Dharwar craton, India, reveals three facies association that range from supratidal to deep subtidal. Sedimentary rocks of this succession are dominated by heterolithic carbonate mudstone, intraformational carbonate conglomerate, and a variety of columnar, domal, and stratiform microbialite facies. Deposition occurred in an extensional regime during development of a low-gradient ramp, where the distribution of microbialite facies is distinctly depth-partitioned. A gradual increase in synoptic relief of columnar stromatolites through the section, and the upward transition from stratiform to columnar microbialites, record a prolonged marine transgression with little or no influx of terrigenous detritus. Siliciclastic influx along the northeastern side of the shelf reflects the redistribution of topographic highs concomitant with large scale volcanic activity. Redistribution of topographic highs eventually led to progradation of peritidal facies and shutting down of the carbonate factory. Earthquake-induced ground shaking and voluminous volcanism experienced by this platform point to the reactivation of a deep-seated mantle-plume that resulted in thermal doming of the Dharwar crust prior to the onset of Cuddapah deposition. Isotopic and elemental chemistry of a selection of Vempalle Formation carbonate rocks record elevated Mn2+ and Fe2+ concentrations and depleted carbon isotope values in inner ramp lagoonal facies, relative to more open marine stromatolitic facies. Patterns of isotopic and elemental variation suggest the presence of geochemically distinct water masses-either within the water column or within substrate pore fluids-that resulted from a combination of globally low marine oxygenation and restricted oceanographic circulation in inner ramp environments. These data suggest that, even in the aftermath of Early Paleoproterozoic oxygenation, that

  10. Thermochronology across tectonic contacts in southwest Turkey defines extensional South Menderes Monocline

    Science.gov (United States)

    Ring, Uwe; Thomson, Stuart; Gessner, Klaus

    2017-04-01

    Apatite and zircon fission track data from the contact zones between the Menderes nappes, the Cycladic Blueschist unit, and the Ören nappe in the Anatolide belt of southwest Turkey provide new constraints on the debated Oligocene-Miocene kinematics of these nappe contacts. Apatite fission track ages range from 18.1±10.5 Ma to 27.8±7.0 Ma for the Menderes nappes and 31.5±5.8 Ma to 42.1±7.2 Ma for the Ören nappe. Zircon fission track ages are 29.2±4.9 Ma to 30.8±2.8 Ma for the Menderes nappes, 30.1±1.7 Ma to 33.3±3.5 Ma for the Cycladic Blueschist unit and 93.0±5.8 Ma to 128.7±12.8 Ma for the Ören nappe. The absence of any well-defined breaks in fission-track ages across the three nappe contacts in the southern Anatolide belt in southeast Turkey indicates that the tectonic contacts have not been reworked during the first phase of Menderes-wide extensional deformation in the late Oligocene and early Miocene. Distinctly older zircon fission track ages from the Ören nappe are mixed ages with single grain ages varying from 300-75 Ma reflecting partial to full resetting during late Cretaceous high-pressure metamorphism. The contact between the Cycladic Blueschist unit and the Ören nappe does not show any significant tectonic movement in the brittle crust after 70 Ma. As none of the tectonic units in the southern Menderes Massif appear to have moved significantly relative to the Earth's surface since the Oligocene, no reactivation could have occurred during the Oligocene/Miocene onset of continental extension. We interpret the steeply dipping part of nappe pile in the southern Menderes Massif as a tilted crustal section that formed as the footwall response to late Oligocene/early Miocene large-scale extension across the Simav detachment.

  11. Protracted weakening during lower crustal shearing along an extensional shear zone

    Science.gov (United States)

    degli Alessandrini, Giulia; Menegon, Luca; Giuntoli, Francesco

    2017-04-01

    This study investigates grain-scale deformation mechanisms in the mafic lower continental crust, with particular focus on the role of syn-kinematic metamorphic reactions and their product - symplectites - in promoting grain size reduction, phase mixing and thus strain localization. The investigated extensional shear zone is hosted in the Finero mafic-ultramafic complex in the Italian Southern Alps. Field and microstructural observations indicate that strain partitioned in gabbroic layers where the primary mineralogical assemblage contained amphibole, forming ultramylonites. These ultramylonites are characterized by isolated porphyroclasts of amphibole, garnet, clinopyroxene and orthopyroxene, embedded in a matrix of plagioclase (ca. 39 vol%) + amphibole (25 vol%) + clinopyroxene (18 vol%) + orthopyroxene (11 vol%) + Fe-Ti oxides (6 vol%) ± apatite (CPO with [001] axes preferentially aligned parallel to the stretching lineation, which we interpret as oriented grain growth during heterogeneous nucleation of amphibole. Pyroxenes and plagioclase lack a CPO and evidence for dislocation creep and dynamic recrystallization. Protracted shearing was initiated by syn-kinematic metamorphic reactions: garnet porphyroclasts formed orthopyroxene + plagioclase symplectites and amphibole porphyroclasts formed pyroxene + plagioclase symplectites. The latter reaction indicates that strain localization initiated with dehydration reactions leading to primary amphibole breakdown into pyroxene and plagioclase, now preserved in the ultramylonite. Geothermobarometry using plagioclase-amphibole pairs in the ultramylonites indicate temperature conditions of ca. 800˚ C and pressures from 8 to 6kbar. This suggests that protracted shearing in the ultramylonites occurred at decreasing pressure and nearly constant T. We suggest that the fluids released during the dehydration reaction were channelized in the ultramylonites and subsequently assisted amphibole nucleation in dilatant sites during

  12. Experimental modelling of tectonics-erosion-sedimentation interactions in compressional, extensional, and strike-slip settings

    Science.gov (United States)

    Graveleau, Fabien; Strak, Vincent; Dominguez, Stéphane; Malavieille, Jacques; Chatton, Marina; Manighetti, Isabelle; Petit, Carole

    2015-09-01

    Tectonically controlled landforms develop morphologic features that provide useful markers to investigate crustal deformation and relief growth dynamics. In this paper, we present results of morphotectonic experiments obtained with an innovative approach combining tectonic and surface processes (erosion, transport, and sedimentation), coupled with accurate model monitoring techniques. This approach allows for a qualitative and quantitative analysis of landscape evolution in response to active deformation in the three end-member geological settings: compression, extension, and strike-slip. Experimental results outline first that experimental morphologies evolve significantly at a short time scale. Numerous morphologic markers form continuously, but their lifetime is generally short because erosion and sedimentation processes tend to destroy or bury them. For the compressional setting, the formation of terraces above an active thrust appears mainly controlled by narrowing and incision of the main channel through the uplifting hanging-wall and by avulsion of deposits on fan-like bodies. Terrace formation is irregular even under steady tectonic rates and erosional conditions. Terrace deformation analysis allows retrieving the growth history of the structure and the fault slip rate evolution. For the extensional setting, the dynamics of hanging-wall sedimentary filling appears to control the position of the base level, which in turn controls footwall erosion. Two phases of relief evolution can be evidenced: the first is a phase of relief growth, and the second is a phase of upstream propagation of topographic equilibrium that is reached first in the sedimentary basin. During the phase of relief growth, the formation of triangular facets occurs by degradation of the fault scarp, and their geometry (height) becomes stationary during the phase of upstream propagation of the topographic equilibrium. For the strike-slip setting, the complex morphology of the wrench zone

  13. Tectono-stratigraphic evolution of a Neogene oblique extensional orogenic basin, southeast Spain

    Science.gov (United States)

    Hodgson, David Mark

    The Tabernas-Sorbas Basin is one of several elongate intramontane basins in the Betic Cordillera that formed on stretched metamorphic rocks, formed during Alpine African-Iberian compression. This study focuses on the early tectono-stratigraphic evolution of the basin from the late Serravallian to the early Messinian (12-6 Ma). During the latest Serravallian, the exhumation and erosion of the hinterland with rapid east-to-west cooling and uplift of the Nevado-Filabride Complex, was reflected by an abrupt east-to-west increase in coarse-grained sediment flux with the establishment of fan-delta sedimentation (Umbria Formation, Pollo Member, and Rambla de Indalecio Member). A major period of tectonic reorganisation in the earliest Tortonian led to the formation of a regional unconformity, a change in palaeoslope and the influx of Nevado-Filabride rock-types (Lomas Colorada Member). Continued basin subsidence, controlled by an anticlockwise change in extension (ENE-WSW), led to the deposition of submarine fans (Mizala Member) and marls with interbedded contained-flow turbidites (the Lucainena Member). The westward-stepping depocentre and a syn-sedimentary tectonic transport direction about the NE-SW, indicate subsidence was controlled by dextral oblique-extension. N-directed movement and anticlockwise rotation of the Alhamilla block led to the compressional deformation at the SE margin with low-angle normal faults reactivated as syn-sedimentary thrust faults and the formation of an angular unconformity. Growth of NE-SW trending anticlines and synclines, and a reduced basin floor gradient changed the bypassing sedimentary system (Unit A) to an aggradational, ponded system (Unit B and C). Dextral oblique-compressional conditions in the east, therefore, were coeval with a dextral oblique-extensional regime in the west during the latest Tortonian. Ponded sheet turbidites, intercalated with rare seismites, healed the topographically complex basin-floor (Unit D) and were

  14. Extensional vs contractional Cenozoic deformation in Ibiza (Balearic Promontory, Spain): Integration in the West Mediterranean back-arc setting

    Science.gov (United States)

    Etheve, Nathalie; Frizon de Lamotte, Dominique; Mohn, Geoffroy; Martos, Raquel; Roca, Eduard; Blanpied, Christian

    2016-07-01

    Based on field work and seismic reflection data, we investigate the Cenozoic tectono-sedimentary evolution offshore and onshore Ibiza allowing the proposal of a new tectonic agenda for the region and its integration in the geodynamic history of the West Mediterranean. The late Oligocene-early Miocene rifting event, which characterizes the Valencia Trough and the Algerian Basin, located north and south of the study area respectively, is also present in Ibiza and particularly well-expressed in the northern part of the island. Among these two rifted basins initiated in the frame of the European Cenozoic Rift System, the Valencia Trough failed rapidly while the Algerian Basin evolved after as a back-arc basin related to the subduction of the Alpine-Maghrebian Tethys. The subsequent middle Miocene compressional deformation was localized by the previous extensional faults, which were either inverted or passively translated depending on their initial orientation. Despite the lateral continuity between the External Betics and the Balearic Promontory, it appears from restored maps that this tectonic event cannot be directly related to the Betic orogen, but results from compressive stresses transmitted through the Algerian Basin. A still active back-arc asthenospheric rise likely explains the stiff behavior of this basin, which has remained poorly deformed up to recent time. During the late Miocene a new extensional episode reworked the southern part of the Balearic Promontory. It is suggested that this extensional deformation developed in a trans-tensional context related to the westward translation of the Alboran Domain and the coeval right-lateral strike-slip movement along the Emile Baudot Escarpment bounding the Algerian Basin to the north.

  15. Extensional and compressional regime driven left-lateral shear in southwestern Anatolia (eastern Mediterranean): The Burdur-Fethiye Shear Zone

    Science.gov (United States)

    Elitez, İrem; Yaltırak, Cenk; Aktuğ, Bahadır

    2016-10-01

    The tectonic framework of the eastern Mediterranean presented in this paper is based on an active subduction and small underwater hills/mountains on the oceanic crust moving toward the north. The Hellenic Arc, the Anaximander Mountains, the Rhodes and Finike basins, the compressional southern regions of the Western Taurides, and the extensional western Anatolian graben are the main interrelated tectonic structures that are shaped by the complex tectonic regimes. There are still heated debates regarding the structural properties and tectonic evolution of the southwestern Anatolia. GPS velocities and focal mechanisms of earthquakes demonstrate the absence of a single transform fault across the Burdur-Fethiye region; however, hundreds of small faults showing normal and left-lateral oblique slip indicate the presence of a regionally extensive shear zone in southwestern Turkey, which plays an important role in the eastern Mediterranean tectonics. The 300-km-long, 75-90-km-wide NE-SW-trending Burdur-Fethiye Shear Zone developed during the formation of Aegean back-arc extensional system and the thrusting of Western Taurides. Today, the left-lateral differential motion across the Burdur-Fethiye Shear Zone varies from 3 to 4 mm/yr in the north to 8-10 mm/yr in the south. This finding could be attributed to the fact that while the subduction of the African Plate is relatively fast beneath the western Anatolia at the Hellenic Trench, it is slow or locked beneath the Western Taurides. Therefore, the GPS vectors and their distributions on land indicate remarkable velocity differences and enable us to determine the left-lateral shear zone located between the extensional and compressional blocks. Furthermore, this active tectonic regime creates differences in topography. This study also demonstrates how deep structures, such as the continuation of the subduction transform edge propagator (STEP) fault between the Hellenic and Cyprus arcs in the continental area, can come into play

  16. Extensional flow produces recumbent folds in syn-orogenic granitoids (Padrón migmatitic dome, NW Iberian Massif)

    Science.gov (United States)

    Fernández, Rubén Díez; Parra, Luis Miguel Martín; Rubio Pascual, Francisco J.

    2017-04-01

    This contribution provides a case example on the generation of large-scale recumbent folds in syn-orogenic granitoids. We analyze the progressive reworking of extension-related structures into later ones after a period of crustal thickening. The Padrón migmatitic dome formed after the climax of the Gondwana-Laurussia collision in the late Paleozoic. Petrostructural analysis carried out in the eastern flank of this dome reveals that extensional flow resulted in progressive exhumation of mainland Gondwana, which rested under peri-gondwanan allochthonous terranes and a suture zone during maximum crustal thickening. Exhumation proceeded up to upper crust levels (andalusite stability field) along with partial melting of the middle-lower crust and with the generation of granitoid laccoliths during an early extensional stage. Newly-formed lithological and mechanical anisotropies, such as the presence of variably-sized sheet-shaped bodies of syn-orogenic granitoids, provided a favorable rheological setting for fold nucleation during the intermediate stages of extension. In extending orogenic crust, whether recumbent folds occur after significant melt production depends on the lateral/vertical flow ratio, and on the orientation of deforming bodies with regard to kinematic/strain axes. We suggest that subhorizontal extensional flow dominated over vertical flow during the early and intermediate stages of the evolution of the Padrón dome. A component of vertical (diapiric) flow caused progressive tilting of the sheet-like bodies and obliquity respect to strain axes. This resulted in the development of regional-scale folds at the expense of syn-orogenic granitoids, such as in the case of the Portomouro recumbent synform. Extensional ductile flow was oblique to the trend of the orogen during the whole process, and directed to the NNW during the formation of recumbent folds. Non-coaxial shearing favored an (NNW-SSE) elongate shape for the syn-kinematic granitic massifs as well

  17. Extensional fault geometry and its flexural isostatic response during the formation of the Iberia - Newfoundland conjugate rifted margins

    Science.gov (United States)

    Gómez-Romeu, Júlia; Kusznir, Nick; Manatschal, Gianreto; Roberts, Alan

    2017-04-01

    Despite magma-poor rifted margins having been extensively studied for the last 20 years, the evolution of extensional fault geometry and the flexural isostatic response to faulting remain still debated topics. We investigate how the flexural isostatic response to faulting controls the structural development of the distal part of rifted margins in the hyper-extended domain and the resulting sedimentary record. In particular we address an important question concerning the geometry and evolution of extensional faults within distal hyper-extended continental crust; are the seismically observed extensional fault blocks in this region allochthons from the upper plate or are they autochthons of the lower plate? In order to achieve our aim we focus on the west Iberian rifted continental margin along the TGS and LG12 seismic profiles. Our strategy is to use a kinematic forward model (RIFTER) to model the tectonic and stratigraphic development of the west Iberia margin along TGS-LG12 and quantitatively test and calibrate the model against breakup paleo-bathymetry, crustal basement thickness and well data. RIFTER incorporates the flexural isostatic response to extensional faulting, crustal thinning, lithosphere thermal loads, sedimentation and erosion. The model predicts the structural and stratigraphic consequences of recursive sequential faulting and sedimentation. The target data used to constrain model predictions consists of two components: (i) gravity anomaly inversion is used to determine Moho depth, crustal basement thickness and continental lithosphere thinning and (ii) reverse post-rift subsidence modelling consisting of flexural backstripping, decompaction and reverse post-rift thermal subsidence modelling is used to give paleo-bathymetry at breakup time. We show that successful modelling of the structural and stratigraphic development of the TGS-LG12 Iberian margin transect also requires the simultaneous modelling of the Newfoundland conjugate margin, which we

  18. Una experiencia en la implementación de extensiones de seguridad para el sistema de nombres de dominio

    OpenAIRE

    Sánchez, Ernesto; Rocabado, Sergio; Díaz, Javier; Arias Figueroa, Daniel; Gamarra, Álvaro

    2016-01-01

    [5 p.] Las extensiones de Seguridad para DNS (DNSSEC) proveen autenticación del origen e integridad de los datos intercambiados a través del protocolo DNS. Las mejoras que ofrece DNSSEC radican principalmente en el uso de una jerarquía de “firmas criptográficas” que permite proteger el flujo de información intercambiado entre Servidores Autoritativos, Servidores DNS Recursivos y Clientes DNS. El presente trabajo tiene por objetivo mostrar una experiencia en la implementación de las Extensi...

  19. SW-NE extensional low-angle faults in Mallorca, key for integrating the Balearic Promontory in the Miocene tectonic evolution of the western Mediterranean

    Science.gov (United States)

    Booth-Rea, Guillermo; Moragues, Lluis; Azañón, Jose Miguel; Roldán, Francisco J.; Pérez-Peña, Jose Vicente

    2017-04-01

    Mallorca forms part of the external thrust belt of the Betics. However, presently, it is surrounded by thin crust of the Valencia Trough and the Algero-balearic basin and is disconnected from the Internal Betic domains. The main tectonic structures described in the island correspond to thrusts that structured the Tramuntana and Llevant Serres during the Late Oligocene to Middle Miocene. Meanwhile, normal faults with NW-SE transport determined the development of Serravallian to Tortonian basins. Here we present a preliminary tectonic model for Mallorca after revising the contacts between supposed thrusts in Tramuntana and Serres de Llevant. This analysis shows the existence of important low-angle extensional faults with SW-NE transport, older than the high-angle NW-SE directed extensional system. Extensional deformation is more pervasive towards the Serres de Llevant where normal faults represent most of the contacts between units. This extensional gradient is favored by ENE-WSW strike-slip transfer faults, and probably, by the faults that bound the southeastern margin of Mallorca. These faults produced the extensional collapse of Mallorca during the Late Langhian-Serravallian, dismembering the external from the internal zones, which now occupy a more westerly position in the core of the Betics.

  20. Uniaxial Extensional Behavior of A--B--A Thermoplastic Elastomers: Structure-Properties Relationship and Modeling

    Science.gov (United States)

    Martinetti, Luca

    At service temperatures, A--B--A thermoplastic elastomers (TPEs) behave similarly to filled (and often entangled) B-rich rubbers since B block ends are anchored on rigid A domains. Therefore, their viscoelastic behavior is largely dictated by chain mobility of the B block rather than by microstructural order. Relating the small- and large-strain response of undiluted A--B--A triblocks to molecular parameters is a prerequisite for designing associated TPE-based systems that can meet the desired linear and nonlinear rheological criteria. This dissertation was aimed at connecting the chemical and topological structure of A--B--A TPEs with their viscoelastic properties, both in the linear and in the nonlinear regime. Since extensional deformations are relevant for the processing and often the end-use applications of thermoplastic elastomers, the behavior was investigated predominantly in uniaxial extension. The unperturbed size of polymer coils is one of the most fundamental properties in polymer physics, affecting both the thermodynamics of macromolecules and their viscoelastic properties. Literature results on poly(D,L-lactide) (PLA) unperturbed chain dimensions, plateau modulus, and critical molar mass for entanglement effect in viscosity were reviewed and discussed in the framework of the coil packing model. Self-consistency between experimental estimates of melt chain dimensions and viscoelastic properties was discussed, and the scaling behaviors predicted by the coil packing model were identified. Contrary to the widespread belief that amorphous polylactide must be intrinsically stiff, the coil packing model and accurate experimental measurements undoubtedly support the flexible nature of PLA. The apparent brittleness of PLA in mechanical testing was attributed to a potentially severe physical aging occurring at room temperature and to the limited extensibility of the PLA tube statistical segment. The linear viscoelastic response of A--B--A TPEs was first

  1. Deformation and breakup of a non-Newtonian slender drop in an extensional flow: inertial effects and stability

    Science.gov (United States)

    Favelukis, Moshe; Lavrenteva, Olga M.; Nir, Avinoam

    2006-09-01

    We consider the deformation and breakup of a non-Newtonian slender drop in a Newtonian liquid, subject to an axisymmetric extensional flow, and the influence of inertia in the continuous phase. The non-Newtonian fluid inside the drop is described by the simple power-law model and the unsteady deformation of the drop is represented by a single partial differential equation. The steady-state problem is governed by four parameters: the capillary number; the viscosity ratio; the external Reynolds number; and the exponent characterizing the power-law model for the non-Newtonian drop. For Newtonian drops, as inertia increases, drop breakup is facilitated. However, for shear thinning drops, the influence of increasing inertia results first in preventing and then in facilitating drop breakup. Multiple stationary solutions were also found and a stability analysis has been performed in order to distinguish between stable and unstable stationary states.

  2. Structural analysis of three extensional detachment faults with data from the 2000 Space-Shuttle Radar Topography Mission

    Science.gov (United States)

    Spencer, J.E.

    2010-01-01

    The Space-Shuttle Radar Topography Mission provided geologists with a detailed digital elevation model of most of Earth's land surface. This new database is used here for structural analysis of grooved surfaces interpreted to be the exhumed footwalls of three active or recently active extensional detachment faults. Exhumed fault footwalls, each with an areal extent of one hundred to several hundred square kilometers, make up much of Dayman dome in eastern Papua New Guinea, the western Gurla Mandhata massif in the central Himalaya, and the northern Tokorondo Mountains in central Sulawesi, Indonesia. Footwall curvature in profile varies from planar to slightly convex upward at Gurla Mandhata to strongly convex upward at northwestern Dayman dome. Fault curvature decreases away from the trace of the bounding detachment fault in western Dayman dome and in the Tokorondo massif, suggesting footwall flattening (reduction in curvature) following exhumation. Grooves of highly variable wavelength and amplitude reveal extension direction, although structural processes of groove genesis may be diverse.

  3. Landscape Response to Active Extensional Faulting and Multiple Local Base Levels: The Perachora Peninsula, Eastern Gulf of Corinth, Greece

    Science.gov (United States)

    Bujanowski-Duffy, O.; Brocklehurst, S. H.; Gawthorpe, R. L.; Finch, E.

    2010-12-01

    We integrate digital topographic analysis, remote sensing and field observations of an active extensional terrain in the Eastern Gulf of Corinth, to elucidate the controls upon spatial and temporal variations in transient landscape evolution. The ~130 km2 Perachora Peninsula is characterised by a suite of E-W trending, mainly northward-dipping normal faults. Interplay between onshore and offshore normal faulting, ongoing regional uplift and eustasy has resulted in a series of reconfigured and diverted drainage networks, with sediment dispersal patterns characterised by trapped endorheic lakes. Quantitative fluvial profile analysis was performed on a 20 m ground-truthed SPOT DEM, with the longitudinal profiles of over 100 ephemeral bedrock streams extracted. Profiles were analysed to determine the size, elevation and distribution of significant long profile convexities (knickpoints) and to develop a map of normalised channel steepness. In addition, field mapping of faults, gorges, wind-gaps, abandoned landscapes, alluvial fans, drainage reversals and drainage capture was conducted to provide details on geomorphic variability across the area and to delimit non-equilibrated portions of the landscape. Using this evidence, along with observations from the planform drainage network, we classify a series of distinct geomorphic domains and deconvolve the key controls and processes which have resulted in such variability in landscape form. The rich variability of controls across the area allows us to determine: i) the role of multiple base levels in controlling landscape evolution and sediment dispersal; ii) active processes in structural relay zones; and iii) insights into the sequence of tectonic events. Our results emphasise how the ongoing evolution of an extensional fault terrain over time-scales of hundreds of thousands of years results in a complex drainage system modified by abandoned landscapes, internal drainage, and steep knickzones. In addition, we demonstrate

  4. Phanerozoic extensional faulting and alteration control on uranium mineralization in trachytes of the Central Eastern Desert of Egypt

    Science.gov (United States)

    Hamdy, Mohamed M.; Waheeb, Anton G.; Aly, Samir M.; Farag, Nagdy M.; Sadek, Adel F.

    2017-12-01

    The Gabal Nasb El Atshan Upper Carboniferous-Lower Permian altered trachytes include uranium up to 3165 ppm. The paleostress and resolved shear stress analyses of the deformation systems in Gabal Nasb El Atshan area indicate that the trachyte was subjected to WNW-ESE to E-W tensile shear stress directed extensional regimes. The low-stress regions in the vicinity of extensional faults and their associated joints were favorable locations for fluid flow and the consequence alteration and U-mineralization. This occurred more extensively along the contacts between the sills of trachyte and the Hammamat sedimentary rocks; where the latter acted as a physical barrier for the alteration fluids migration outward. Alteration styles include albitization, aegirinization, arfvedsonization, chloritization and ferruginisation. The albitization is the most common sodic metasomatism, giving sanidine from Or98.8Ab0.7 to Or62.3Ab37.6, anorthoclase from Or51.4Ab48.0 to Or12.2Ab87.6 and albite from Or11.0Ab89.0 to Or0.8Ab99.2. Aegirine and arfvedsonite formed due to decreasing sodium activity in the metasomatic fluids. Sodic metasomatism may be the source of uranium-enrichment, taking place during the late magmatic to deuteric processes. This was followed by a retrograde alteration of chloritization between 175 and 42 °C toward precipitation of Fe-oxides and alteration of primary uranium. Surficial low-temperature alteration remobilized and redistributed the produced uranylhydroxides and ferruginisation caused the reduction and adsorption of U forming betafite, uranophane, soddyite, umohoite, uranotile and uranopilite.

  5. A numerical model study to evaluate the effect of sedimentation on the thermal structure of extensional basin

    Science.gov (United States)

    Kim, Yeseul; Lee, Changyeol

    2017-04-01

    Sedimentation on extensional basins allows fast cooling of the shallow crust because the overlying sediments efficiently transfer heats from the shallow crust to the surface and hinders heat transfer from the underlying deep crust and mantle to the surface, which lowers the surface heat flux (e.g., covering effect). Therefore, it is important to evaluate the impact of transient sedimentation on the thermal structure of the extensional basin. We designed a numerical model which considers transient sedimentation based on the kinematic basin extension formulated by Jarvis and McKenzie (1980). In the model study, we vary duration of extension, stretch factor (β) and sediment thickness of the basin with 100 Myr of cooling since the basin extension ceases. First, we evaluate the effect of duration of extension on the thermal structure of the basin by using the stretch factor (β) and sediment thickness of 2 and 2 km, respectively. Our model calculations show that longer duration of extension results in larger decreases in the geotherm and surface heat flux of the basin. Second, we evaluate the effect of stretch factor (β) on the thermal structure of the basin by using the duration of extension and sediment thickness of 20 Myr and 2 km, respectively. The results indicate that larger stretch factor (β) results in larger decreases in the geotherm and surface heat flux of the basin. Evaluation of the effect of the sediment thickness is ongoing by keeping the duration of extension and stretch factor (β) of 20 Myr and 2, respectively. We will apply our findings to analyze the thermal structure of the Ulleung and Yamato Basins in the East (Japan) Sea.

  6. A long-lived Late Cretaceous-early Eocene extensional province in Anatolia? Structural evidence from the Ivriz Detachment, southern central Turkey

    Science.gov (United States)

    Gürer, Derya; Plunder, Alexis; Kirst, Frederik; Corfu, Fernando; Schmid, Stefan M.; van Hinsbergen, Douwe J. J.

    2018-01-01

    Central Anatolia exposes previously buried and metamorphosed, continent-derived rocks - the Kırşehir and Afyon zones - now covering an area of ∼300 × 400 km. So far, the exhumation history of these rocks has been poorly constrained. We show for the first time that the major, >120 km long, top-NE 'Ivriz' Detachment controlled the exhumation of the HP/LT metamorphic Afyon Zone in southern Central Anatolia. We date its activity at between the latest Cretaceous and early Eocene times. Combined with previously documented isolated extensional detachments found in the Kırşehir Block, our results suggest that a major province governed by extensional exhumation was active throughout Central Anatolia between ∼80 and ∼48 Ma. Although similar in dimension to the Aegean extensional province to the east, the Central Anatolian extensional province is considerably older and was controlled by a different extension direction. From this, we infer that the African slab(s) that subducted below Anatolia must have rolled back relative to the Aegean slab since at least the latest Cretaceous, suggesting that these regions were underlain by a segmented slab. Whether or not these early segments already corresponded to the modern Aegean, Antalya, and Cyprus slab segments remains open for debate, but slab segmentation must have occurred much earlier than previously thought.

  7. Extensional tectonics, basement uplift and Stephano-Permian collapse basin in a late Variscan metamorphic core complex (Montagne Noire, Southern Massif Central)

    Science.gov (United States)

    Echtler, H.; Malavieille, J.

    1990-05-01

    The Montagne Noire is interpreted as a Variscan metamorphic core complex composed of: (1) an uplifted core of assumed Proterozoic gneisses and migmatitic rocks associated with anatectic granites related to a late Hercynian LP/HT metamorphism and (2) an upper plate composed of low-grade or non-metamorphic folded Palaeozoic sediments. These two units are separated by normal and wrench/normal ductile shear zones and detachment faults. These fault zones are characterized by synmetamorphic S- C type mylonites and stretching lineations superimposed on the earlier compressional deformation features. Early orogenic shortening is marked by polyphase, large-scale folding in the core rocks (Axial Zone) and in the thrust nappes of the upper plate. The late Variscan evolution of this massif is in general characterized by extensional tectonics. Kinematic analysis of the extensional deformation shows that displacement on the fault zones is parallel to retrogressive stretching lineations. Shear sense criteria indicate an upper plate movement towards the northeast in the northeastern part of the massif, and towards the south-southwest in the southwestern part. At the same time, transcurrent right-lateral movements occurred along the subvertical ENE-trending boundaries of the core zone. The late orogenic extensional tectonism in the Montagne Noire is attributed to uplift of the previously thickened core zone controlled by an extensional stage between two right-lateral wrench fault zones. Associated with the late Hercynian metamorphic core complex, a Stephano-Permian continental sedimentary basin was formed along the active detachment to the northeast of the uplifted core. The tectonic fabric of the basal coarse clastic Stephanian sediments shows an extension parallel to the ductile stretching in the underlying extensional shear zones. The geometry of unconformably layered clastic sequences, synsedimentary brittle faults, and the various deformation features are consistent with

  8. Extensional Detachment faulting in melange rocks. Plurikilometres migration by W the External Zone (Cordillera Bética, Spain)

    Science.gov (United States)

    Roldán, Francisco Javier; Azañon, Jose Miguel; Rodríguez, Jose; Mateos, Rosa Maria

    2014-05-01

    The synthesis and correlation of units carried out in the continuous geological map (Roldán et al., 2012), has revealed a fragmentation of the carbonate outcrops belong to the Subbetic Domain (García-Hernández et al., 1980). Subbetic NW verging thrust and fold axial traces have not lateral continuity and Jurassic carbonate outscrops appear as klippes on the olistotromic unit. These ductile structures that can be observed in the internal structure of these jurassic blocks are unrelated to the brittle-ductile deformation bands observed at the basal pelitic levels. Basal detachments are rooted in: a) the Olistostromic unit, a Upper Langhian-Lower Serravallian breccia constituted by gypsum-bearing clay and marls; b) Cretaceous-Tertiary marly sedimentary rocks (Rodríguez-Fernández, et al., 2013) . In both kind of rocks, cataclastic structures allows to infer a top-to-the WSW displacement. Paleostress measurements, made on these detachments levels, are compatible with a extensional regime (Roldán et al., 2012). At the same time, the analysis and interpretation of subsurface data (seismic surveys and borehole testing) shows that the Subbetic Domain (External Subbetic, Molina 1987) are affected by westward low-angle normal faults. A balanced cross-section, based on morphological and cartographic data in the area between Sierra de Cabra and Sierra de Alta Coloma (Valdepeñas de Jaén), shows plurikilometric displacements which has been produced during Late Serravallian-Early Tortonian times. References: García-Hernández, M., López-Garrido, A.C., Rivas, P., Sanz de Galdeano, C., Vera, J.A. (1980): Mesozoic paleogeographic evolution of the zones of the Betic Cordillera. Geol. Mijnb. 59 (2). 155-168. Molina, J.M. (1987). Análisis de facies del Mesozoico en el Subbético. Tesis Doctoral, Univ. Granada. 518 p. Rodríguez-Fernández, J., Roldán, F. J., Azañón, J.M. y García-Cortés, A. (2013). El colapso gravitacional del frente orogénico a lpino en el Dominio Subb

  9. Mesozoic alkaline plutonism: Evidence for extensional phase in Alpine-Himalayan orogenic belt in Central Alborz, north Iran

    Directory of Open Access Journals (Sweden)

    Roghieh Doroozi

    2017-12-01

    Full Text Available The Kamarbon Jurassic alkaline basic intrusion crops out in Central Alborz, north Iran, along the northern margin of the Alpine-Himalayan belt. The intrusion includes foid gabbros at the margins and foid monzodiorites towards the center. The foid monzodiorites are considered as the evolved melts after the fractional crystallization mostly of olivine and clinopyroxene from a foid gabbro parental magma. Based on mass balance calculation the evolution of the Kamarbon alkaline gabbro could be explained by 19.2% fractionation of clinopyroxene, 13.8% of olivine, 3% of plagioclase and 1.0% Ti-Magnetite, with 63% of residual liquid. REE inversion modeling indicates that the Kamarbon intrusion magma was generated by low degrees (<3% of partial melting from a garnet-bearing mantle source. In primitive mantle-normalized incompatible element diagrams, the Kamarbon rocks show enrichment in LILE elements (Ba, Rb, Sr and Th, HFSE elements (Nb, Ta, Ti, Zr and Hf and P and depletion in K, Y and HREE (Yb, Lu which are similar to patterns of HIMU-OIBs or intraplate alkaline magmas. According to the existence of extensional phases and occurrence of different rifting during late Triassic to middle Jurassic in Central Alborz, the formation of Kamarbon intrusion could be related to an intracontinental rifting.

  10. Two successive crustal melting events resulting from extensional exhumation and then thrusting of the Ronda Peridotites (South Spain)

    Science.gov (United States)

    Frasca, Gianluca; Gueydan, Frédéric; Poujol, Marc; Brun, Jean-Pierre; Parat, Fleurice; Monié, Patrick; Pichat, Alexandre; Maziers, Sophie

    2017-04-01

    The Alboran Domain, situated at the western end of the Mediterranean subduction system, is characterized by the Ronda Peridotites, one of the world largest exposures of sub-continental mantle. Using U-Pb (LA-ICP-MS) and Ar-Ar dating, we precisely dated two tectonic events associated with the Tertiary exhumation of the Ronda Peridotites. First, shearing along the Crust-Mantle Extensional Shear Zone caused, at ca. 22.5 Ma, mantle exhumation, local partial melting in the deep crust and coeval cooling in the upper crust. Second, the Ronda Peridotites Thrust triggered the final crustal emplacement of the peridotites onto the continental crust at ca. 21 Ma, as testified by granitic intrusions in the thrust hanging-wall. The tectonic evolution of the western Alboran Domain is therefore characterized by a fast switch from a continental lithosphere extension in a backarc setting, with sub-continental mantle exhumation, to a rift inversion by thrusting driven by shortening of the subduction upper plate.

  11. A Lorentz force magnetometer based on a piezoelectric-on-silicon square-extensional mode micromechanical resonator

    Science.gov (United States)

    Ghosh, S.; Lee, J. E.-Y.

    2017-06-01

    In this letter, we present a Lorentz force magnetic field sensor based on a thin-film piezoelectric-on-silicon (TPoS) CMOS-compatible resonator for the detection of an out-of-plane (perpendicular to the plane of fabrication) magnetic field. We here exploit the fundamental breathing mode of vibration in a suspended square plate, which is commonly referred to as the square-extensional (SE) mode. The symmetric stress profile of the SE mode avails stresses in the two orthogonal in-plane axes to be effectively coupled into a charge output through the piezoelectric transducers. This in turn enhances the output motional current from the device, which effectively determines the responsivity of the device. In this context, the responsivity has been defined as a ratio of output motional current to the external magnetic field, which has been further normalized against the input reference current of the device. The reported device has recorded a responsivity of 6950 ppm/T (μA/A.T) at a resonant frequency of 5.28 MHz and a reasonable mechanical quality (Q) factor of 1056 in air.

  12. Tectonic burial, thrust emplacement, and extensional exhumation of the Cabot nappe in the Appalachian hinterland of Cape Breton Island, Canada

    Science.gov (United States)

    Lynch, Gregory

    1996-02-01

    Silurian imbricate thrusting, Early Devonian high-grade metamorphic nappe emplacement, and Devonian-Carboniferous extensional denudation characterize deformation in the Appalachian hinterland of Cape Breton Island. Compressional deformation following Early Silurian arc volcanism features imbrication of Cambrian-Precambrian basement rocks of Gondwana derivation with Ordovician-Silurian cover sequences across thick zones of mylonite during south directed transport. High grade metamorphism and gneissic rocks of late Silurian age in the region indicate that significant tectonic burial and crustal thickening occurred as a result of the thrusting. Partial denudation of the high grade assemblages occurred during Early Devonian thrust emplacement of the Cabot nappe toward the northwest, along the Highlands Shear Zone. The nappe is characterized by an amphibolitic gneiss and high-grade schist complex defining a large folded klippe above Silurian units. Kyanite is widespread within the nappe, and a distinctive feature of the thrust sheet is the dynamothermal metamorphism of cooler greenschist-grade footwall rocks producing inverted isograds; staurolite is regionally distributed and occurs in pelitic units in the immediate footwall of the Highlands Shear Zone forming a discontinuous halo around the klippe. Greenschist-grade footwall rocks are exposed in structural windows as a result of folding and faulting. Shear sense indicators along the margins of the Cabot nappe have been rotated into their present positions due to superposed folding, providing apparent movement directions for the nappe. Complete exhumation to surface occurred during Late Devonian extension along the low-angle Margaree Shear Zone.

  13. Late extensional shear zones and associated recumbent folds in the Alpujarride subduction complex, Betic Cordillera, southern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Orozco, M.; Alonso-Chaves, F.; Platt, J.

    2017-11-01

    The existence in the Alpujarride Complex (Betic Cordillera, southern Spain) of a relatively continuous extensional event (following crustal thickening) is based on detailed structural studies and is consistent with the P-T paths and geochronological data established for the Alpujarride rocks. According to our research, the Alpujarride Complex contains two large-scale shear zones accommodating early Miocene extension. The shear zones contain km-scale recumbent folds, some with sheath fold geometry, and megaboudinage structures, and are closely associated with detachment faults. Large-scale folds and boudins cause dome-like undulations in the detachments, which are inferred to overlap in time with the deformation in the shear zones. One shear zone in the eastern part of the orogen is top-N; the other, in the western part, is top-E. The change in the shear direction may represent a temporal evolution in the direction of shear, possibly related to a change in the subduction direction in space and time.

  14. Symmetry during the syn- and post-rift evolution of extensional back-arc basins: the role of inherited orogenic structures

    Science.gov (United States)

    Balazs, Attila; Burov, Evgueni; Matenco, Liviu; Vogt, Katharina; Francois, Thomas; Cloetingh, Sierd

    2017-04-01

    Rheological heterogeneities in the lithosphere have first order control on the topographical expression of tectonic processes. Pre-existing orogenic suture zones localize extensional deformation resulting in asymmetric basins. Such crustal geometries are often in contrast with the more symmetric regional lithospheric structure observed beneath extensional basins. We study such (a)symmetries and their controlling parameters by conducting a series of 2D thermo-mechanical numerical experiments of the extension of an overthickened, hot lithosphere that contains a weakness zone. The modelling shows that syn-rift subsidence is low to moderate creating asymmetric half grabens where extension migrates in space and time, grouped in an overall symmetrical appearance on a larger scale. The initial lithospheric mantle asymmetry is attenuated by the lateral heat conduction and further dynamic evolution of the thermal anomaly during the "post-rift" phase, resulting in differential vertical movements of the crust including additional 2-3 km subsidence in the basin centre. The modelling shows that the initial crustal and lithospheric thicknesses, rate of extension and surface processes strongly control the thermo-mechanical evolution of the extensional system. The numerical modelling yields new insights into the mechanics of coupling between near-surface kinematics and the evolution of deep lithospheric structure in the Pannonian back-arc basin of Central Europe.

  15. Viscosidade extensional e em cisalhamento de suspensões acidificadas de amido de amaranto e caseinato de sódio Extensional and shear viscosity of acidified amaranth starch-sodium caseinate suspensions

    Directory of Open Access Journals (Sweden)

    Angela Maria Gozzo

    2009-09-01

    Full Text Available Foram avaliadas as viscosidades extensional e em cisalhamento de suspensões acidificadas de amido de amaranto-caseinato de sódio. Sistemas mistos de amido de amaranto-caseinato de sódio acidificados com glucona-delta-lactona (GDL foram estudados por ensaios reológicos em compressão biaxial e cisalhamento. Os efeitos da velocidade de acidificação (lenta e rápida e pH final (neutro e no ponto isoelétrico da caseína foram avaliados considerando as interações entre os biopolímeros e sua consequente influência nos parâmetros reológicos. Todas as amostras apresentaram comportamento pseudoplástico, no entanto, a adição de caseinato de sódio nas suspensões de amido, em pH neutro, promoveu um efeito negativo sobre a viscosidade aparente. Amostras acidificadas apresentaram um aumento na complexidade do sistema devido à formação da rede de amido e caseína, observando que a força necessária para o escoamento foi sempre maior para as amostras contendo concentrações maiores de caseinato. Isso mostra que a agregação e gelificação da proteína promovidas pela acidificação, impediram a microsseparação de fases. Esta rede foi mais forte em sistemas gelificados lentamente, devido à formação de uma rede de proteína mais organizada. Apesar da técnica de compressão biaxial imperfeita ser limitada para avaliação de determinados sistemas, neste estudo, mostrou ser um modo prático e eficiente de se mensurar o comportamento reológico.Extensional and shear viscosity of acidified amaranth starch-sodium caseinate suspensions were evaluated. Mixed systems of amaranth starch-sodium caseinate acidified with glucone-delta-lactone (GDL were studied using rheological measurements under biaxial compression and shear. The effects of the acidification rate (slow and fast and final pH (neutral and isoelectric point of casein were evaluated considering the interactions between biopolymers and their influence on the rheological parameters

  16. Oblique transfer of extensional strain between basins of the middle Rio Grande rift, New Mexico: Fault kinematic and paleostress constraints

    Science.gov (United States)

    Minor, Scott A.; Hudson, Mark R.; Caine, Jonathan S.; Thompson, Ren A.

    2013-01-01

    The structural geometry of transfer and accommodation zones that relay strain between extensional domains in rifted crust has been addressed in many studies over the past 30 years. However, details of the kinematics of deformation and related stress changes within these zones have received relatively little attention. In this study we conduct the first-ever systematic, multi-basin fault-slip measurement campaign within the late Cenozoic Rio Grande rift of northern New Mexico to address the mechanisms and causes of extensional strain transfer associated with a broad accommodation zone. Numerous (562) kinematic measurements were collected at fault exposures within and adjacent to the NE-trending Santo Domingo Basin accommodation zone, or relay, which structurally links the N-trending, right-stepping en echelon Albuquerque and Española rift basins. The following observations are made based on these fault measurements and paleostresses computed from them. (1) Compared to the typical northerly striking normal to normal-oblique faults in the rift basins to the north and south, normal-oblique faults are broadly distributed within two merging, NE-trending zones on the northwest and southeast sides of the Santo Domingo Basin. (2) Faults in these zones have greater dispersion of rake values and fault strikes, greater dextral strike-slip components over a wide northerly strike range, and small to moderate clockwise deflections of their tips. (3) Relative-age relations among fault surfaces and slickenlines used to compute reduced stress tensors suggest that far-field, ~E-W–trending σ3 stress trajectories were perturbed 45° to 90° clockwise into NW to N trends within the Santo Domingo zones. (4) Fault-stratigraphic age relations constrain the stress perturbations to the later stages of rifting, possibly as late as 2.7–1.1 Ma. Our fault observations and previous paleomagnetic evidence of post–2.7 Ma counterclockwise vertical-axis rotations are consistent with increased

  17. In vitro antimicrobial activity of essential oils from oregano, garlic, clove and lemon against pathogenic bacteria isolated from Anomalocardia brasilianaAtividade antimicrobiana in vitro dos óleos essenciais de orégano, alho, cravo e limão sobre bactérias patogênicas isoladas de vôngole

    Directory of Open Access Journals (Sweden)

    Tânia Fraga Barros

    2011-10-01

    Full Text Available Natural preservative substances are an efficient and economic alternative, because the aromatical plants and rich spices in essential oils characterized by a notable are gotten from antimicrobial activity, and for this reason, its derived products can be used to delay or to inhibit the growth of microorganisms. The objective of this study was to evaluate the antibacterial activity of essential oils of clove, limon, oregano (Origanum vulgare ssp. Hirtum and garlic several species of bacteria like Staphylococcus aureus and Escherichia coli isolated of vongole (Anomalocardia Brasiliana and bacteria standard ATCC (American Type Culture Collection: Escherichia coli, Staphylococcus aureus and Salmonella cholerasuis, through diffusion test and after it was determinate the Minimum Inhibitory Concentration (MIC. In this study it was observed that the garlic essential oil presented antibacterial activity front the S. aureus and the S. cholerasuis.; already the oils of clove and oregano (Origanum vulgare ssp. Hirtum had presented activity front to all the analyzed bacteria, however the oregano oil presented the bigger bacterial inhibition, 26.7mm e 29,3mm for E. coli e S. aureus respectively. The essential oil of lemon did not demonstrate antibacterial activity. In such a way the oregano and clove essential oils that they had presented antibacterial activity appeared to be the most preferable agent for future research.Antimicrobianos de origem natural são alternativas eficazes e econômicas, pois são obtidos a partir das plantas aromáticas e especiarias ricas em óleos essenciais caracterizados por uma notável atividade antimicrobiana, e por esta razão, seus produtos derivados podem ser usados para retardar ou inibir a multiplicação microbiana. O objetivo deste estudo foi avaliar a atividade antibacteriana dos óleos essenciais de cravo, limão, orégano e alho sobre as cepas de Staphylococcus aureus e Escherichia coli isolados do v

  18. The Finne fault zone (central Germany): structural analysis of a partially inverted extensional fault zone by balanced cross-sections

    Science.gov (United States)

    Malz, Alexander; Kley, Jonas

    2012-11-01

    The Finne fault zone, located in central Germany to the southwest of the Harz mountains, was studied by means of detailed map analysis, investigations of fault displacement and balanced cross-sections for the most strongly deformed area in the center of the fault zone (ca. 50 % of total fault zone length). The system of the Finne fault zone shows a nearly 100-km-long straight flexure that symbolizes the morphological and geological northeastern border of the Thuringian basin. In the central part, which should be surveyed here, the fault zone corresponds to a distinctive narrow band of highly deformed Triassic sedimentary rocks. The northwestern and especially the southeastern parts of the research area are developed as several parallel branch faults. In the southeastern elongation of the fault zone, which is not part of our survey, the sedimentary cover is missing. Here, it is possible to gain insight to the fact that the basement is also involved to the kinematics of the fault zone. Based on our results, we propose a subdivision of the fault zone into four sectors. From the northwest to the southeast, we interpret the structure of these sectors to reflect (1) a compressional flexure, (2) an overthrust graben, and (3) a partially inverted and folded half graben. In the extreme southeast (4), the fault zone is characterized by an anticline with some strike-slip movement parallel to the fold axis. This segmentation is caused by a thrust fault system whose strike direction deviates slightly from that of the earlier formed graben system. The structural configuration can be explained by a two-phase deformation, in which the contractional strain exceeded the preceding extensional deformation. In the investigated area, the horizontal shortening attains a maximum of ca. 1 km. The present study confirms many earlier hypotheses, presents new results on the deformation history of the fault zone, and attempts to evaluate the deformation in a regional geological context. The

  19. Microstructural investigations on carbonate fault core rocks in active extensional fault zones from the central Apennines (Italy)

    Science.gov (United States)

    Cortinovis, Silvia; Balsamo, Fabrizio; Storti, Fabrizio

    2017-04-01

    The study of the microstructural and petrophysical evolution of cataclasites and gouges has a fundamental impact on both hydraulic and frictional properties of fault zones. In the last decades, growing attention has been payed to the characterization of carbonate fault core rocks due to the nucleation and propagation of coseismic ruptures in carbonate successions (e.g., Umbria-Marche 1997, L'Aquila 2009, Amatrice 2016 earthquakes in Central Apennines, Italy). Among several physical parameters, grain size and shape in fault core rocks are expected to control the way of sliding along the slip surfaces in active fault zones, thus influencing the propagation of coseismic ruptures during earthquakes. Nevertheless, the role of grain size and shape distribution evolution in controlling the weakening or strengthening behavior in seismogenic fault zones is still not fully understood also because a comprehensive database from natural fault cores is still missing. In this contribution, we present a preliminary study of seismogenic extensional fault zones in Central Apennines by combining detailed filed mapping with grain size and microstructural analysis of fault core rocks. Field mapping was aimed to describe the structural architecture of fault systems and the along-strike fault rock distribution and fracturing variations. In the laboratory we used a Malvern Mastersizer 3000 granulometer to obtain a precise grain size characterization of loose fault rocks combined with sieving for coarser size classes. In addition, we employed image analysis on thin sections to quantify the grain shape and size in cemented fault core rocks. The studied fault zones consist of an up to 5-10 m-thick fault core where most of slip is accommodated, surrounded by a tens-of-meters wide fractured damage zone. Fault core rocks consist of (1) loose to partially cemented breccias characterized by different grain size (from several cm up to mm) and variable grain shape (from very angular to sub

  20. Basement-cover relationships in the Grampian Caledonides of Scotland - extensional strain preceding continental rupture and generation of the Laurentian ocean-continent transition zone

    Science.gov (United States)

    Leslie, Graham; Smith, Martin; Gillespie, Martin; Thomas, Christopher; Krabbendam, Maarten

    2010-05-01

    Ancient rift and passive margin basins can frequently only be studied in outcrop after uplift following orogenesis. Such basins are thus deformed, metamorphosed and partially eroded as a consequence of closure of the oceanic system in which the passive margin was originally established. As a result there are significant challenges in restoration and interpretation of the original basin geometries and lithostratigraphical relationships. The mid-Neoproterozoic to Cambrian Dalradian Supergroup of Scotland and Ireland was intensively deformed and metamorphosed by mid-Ordovician arc-accretion (c. 460 Ma) during the Caledonian Orogeny. Nevertheless, we can determine a history of stretching and break-up associated with rupture of the Neoproterozoic supercontinent of Rodinia and opening of Iapetus. Continental fragments apparently separated from the passive margin during rift-drift transition. The extensional structures bounding the various fragments subsequently exerted control on the collisional geometry and acted as nuclei for deformation structures during Caledonian orogenesis. Reading the record of Neoproterozoic extension in the Scottish Caledonides is further complicated by the need to unravel the structural record at the boundary between the Dalradian Supergroup and underlying early-Neoproterozoic metamorphic basement. The depositional age of the Dalradian succession is not well constrained but the oldest strata could pre-date 800 Ma. If such should be the case, then the thick siliciclastic deposits characteristic of the lower Dalradian Grampian Group succession accumulated before 800 Ma during an early stretching phase (distributed high angle faulting) that led to crustal thinning (low-angle shearing). A major low-angle, regional-scale ductile shear zone in the upper levels of the underlying basement is arranged sub-parallel to the present structural base of the Dalradian. The high-temperature regional metamorphism in basement is c. 830 Ma old while the ductile

  1. From detachment to transtensional faulting: A model for the Lake Mead extensional domain based on new ages and correlation of subbasins

    Science.gov (United States)

    Beard, L.; Umhoefer, P. J.; Martin, K. L.; Blythe, N.

    2007-12-01

    New studies of selected basins in the Miocene extensional belt of the northern Lake Mead domain suggest a new model for the early extensional history of the region (lower Horse Spring Formation and correlative strata). Critical data are from (i) Longwell Ridges area west of Overton Arm and within the Lake Mead fault system, (ii) Salt Spring Wash basin in the hanging wall of the South Virgin-White Hills detachment (SVWHD) fault, and (iii) previously studied subbasins of the south Virgin Mountains in the Gold Butte step-over region. The basins and faulting patterns suggest two stages of basin development related to two distinct faulting episodes, an early period of detachment faulting followed by a switch to faulting mainly along the Lake Mead transtensional fault system while detachment faulting waned. Apatite fission track ages suggest the footwall block of the SVWHD was cooling at 18-17 Ma, but the only evidence for basin deposition at that time is in the Gold Butte step-over where slow rates of sedimentation and facies patterns make faulting on the north side of the Gold Butte block ambiguous. The first basin stage was ca. 16.5 to 15.5 Ma, during which there was slow to moderate faulting and subsidence in a basin along the SVWHD and north of Gold Butte block in the Gold Butte step-over basin; the step- over basin had complex fluvial and lacustrine facies and was synchronous with landslides and debris flows in front of the SVWHD. At ca. 15.5-14.5 Ma, there was a [dramatic] increase in sedimentation rate related to formation of the Gold Butte fault, a change from lacustrine to widespread fluvial, playa, and local landslide facies in the step-over basin, and the peak of exhumation and faulting rates on the SVWHD. The simple step-over basin broke up into numerous subbasins [at[ as initial faults of the Lake Mead fault system formed. From 14.5 to 14.0 Ma, there was completion of a major change from dominantly detachment faulting to dominantly transtensional faulting

  2. Estrategias de gestión del valor de marca de las cabeceras de prensa españolas a través de sus extensiones digitales

    Directory of Open Access Journals (Sweden)

    María VICTORIA-MAS

    2017-01-01

    Full Text Available Las marcas periodísticas encuentran en las plataformas digitales una gran oportunidad de mantener y aumentar el valor que tienen. Solo una minoría de empresas informativas tradicionales ha desarrollado estrategias de gestión de ese valor. Cuando las extensiones digitales no son coherentes con las marcas madre, pueden diluir su imagen y acabar siendo contraproducentes. Este artículo explora hasta qué punto las marcas de prensa utilizan sus extensiones digitales para aumentar su valor y cómo comunican su marca a través de ellas. La metodología escogida para ello es el análisis de contenidos de las ediciones online y de los perfiles en redes sociales de las 44 cabeceras más leídas en España. Los resultados indican que esas marcas no han explotado aún todo el potencial que las plataformas online tienen para ganar valor. Realizan solo una comunicación parcial de sí mismas y no han llevado a cabo algunas de las acciones que se consideran prioritarias en la gestión estratégica de la marca, tales como la definición de la identidad y la concreción de la misión. La discusión de los resultados permite proponer algunas estrategias de creación de valor de marca en las empresas informativas.

  3. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Annual report, March 1996--March 1997

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Groshong, R.H.

    1997-08-01

    Gilbertown Field is the oldest oil field in Alabama and produces oil from chalk of the Upper Cretaceous Selma Group and from sandstone of the Eutaw Formation along the southern margin of the Gilbertown fault system. Most of the field has been in primary recovery since establishment, but production has declined to marginally economic levels. This investigation applies advanced geologic concepts designed to aid implementation of improved recovery programs. The Gilbertown fault system is detached at the base of Jurassic salt. The fault system began forming as a half graben and evolved in to a full graben by the Late Cretaceous. Conventional trapping mechanisms are effective in Eutaw sandstone, whereas oil in Selma chalk is trapped in faults and fault-related fractures. Burial modeling establishes that the subsidence history of the Gilbertown area is typical of extensional basins and includes a major component of sediment loading and compaction. Surface mapping and fracture analysis indicate that faults offset strata as young as Miocene and that joints may be related to regional uplift postdating fault movement. Preliminary balanced structural models of the Gilbertown fault system indicate that synsedimentary growth factors need to be incorporated into the basic equations of area balance to model strain and predict fractures in Selma and Eutaw reservoirs.

  4. Structure and provenance of Late Cretaceous-Miocene sediments located near the NE Dinarides margin: Inferences from kinematics of orogenic building and subsequent extensional collapse

    Science.gov (United States)

    Stojadinovic, Uros; Matenco, Liviu; Andriessen, Paul; Toljić, Marinko; Rundić, Ljupko; Ducea, Mihai N.

    2017-07-01

    The NE part of the Dinarides Mountain chain, located near their junction with the Carpatho-Balkanides, is an area where sedimentary basins associated with the Neotethys subduction and collision are still exposed. We performed a provenance study, based on detrital fission track thermochronology combined with zircon Usbnd Pb magmatic geochronology, and existing studies of kinematics and exhumation. Our study shows rapid sedimentation in the trench and forearc basin overlying the upper European tectonic plate. A number of latest Cretaceous-Early Paleocene igneous provenance ages show a dominant magmatic source area, derived from a Late Cretaceous subduction-related arc. This arc shed short time lag sediments in the forearc and the trench system, possibly associated with focused exhumation in the Serbo-Macedonian margin. This was followed by burial of the trench sediments and a novel stage of Middle-Late Eocene exhumation driven by continued continental collision that had larger effects than previously thought. The collision was followed by Late Oligocene-Miocene exhumation of the former lower Adriatic plate along extensional detachments that reactivated the inherited collisional contact along the entire Dinarides margin. This event re-distributed sediments at short distances in the neighboring Miocene basins. Our study demonstrates that the Dinarides orogenic system is characterized by short lag times between exhumation and re-deposition, whereas the upper tectonic plate is significantly exhumed only during the final stages of collision. Such an exhumation pattern is not directly obvious from observing the overall geometry of the orogen.

  5. Oven controlled N++ [1 0 0] length-extensional mode silicon resonator with frequency stability of 1 ppm over industrial temperature range

    Science.gov (United States)

    You, Weilong; Pei, Binbin; Sun, Ke; Zhang, Lei; Yang, Heng; Li, Xinxin

    2017-10-01

    This paper presents an oven controlled N++ [1 0 0] length-extensional mode silicon resonator, with a lookup-table based control algorithm. The temperature coefficient of resonant frequency (TCF) of the N++ doped resonator is nonlinear, and there is a turnover temperature point at which the TCF is equal to zero. The resonator is maintained at the turnover point by Joule heating; this temperature is a little higher than the upper limit of the industrial temperature range. It is demonstrated that the control algorithm based on the thermoresistor on the substrate and the lookup table for heating voltage versus chip temperature is sufficiently accurate to achieve a frequency stability of  ±0.5 ppm over the industrial temperature range. Because only two leads are required for electrical heating and piezoresistive sensing, the power required for heating of this resonator can be potentially lower than that of the oscillators with closed-loop oven control algorithm. It is also shown that the phase noise can be suppressed at the turnover temperature because of the very low value of the TCF, which justifies the usage of the heating voltage as the excitation voltage of the Wheatstone half-bridge.

  6. Petrogenesis of Neoarchean metavolcanic rocks in Changyukou, Northwestern Hebei: Implications for the transition stage from a compressional to an extensional regime for the North China Craton

    Science.gov (United States)

    Liou, Peng; Shan, Houxiang; Liu, Fu; Guo, Jinghui

    2017-03-01

    fractional crystallization of basaltic andesites (high-Al basalts) and andesites. Mixing of magmas at various stages along the fractionation course of basaltic andesites (high-Al basalts) toward rhyolites promotes the trend of the calc-alkaline series. To reconcile the 2.55 to 2.5 Ga TTGs derived from overthickened crust, the 2.51 to 2.50 Ga calc-alkaline volcanic rocks derived from thickened crust, tholeiitic basalts representing low pressure and an extensional tectonic setting, 2493 Ma leucosyenogranites derived from overthickened crust, 2437 Ma biotite-monzogranites derived from slightly thinner crust than leucosyenogranites but still thickened, as well as the clockwise hybrid ITD and IBC P-T paths of the HP granulites and widespread extension and rifting setting within the NCC from 2300 Ma, we propose a model of an evolving subduction process. Among them, the composition of the 2.5 Ga Changyukou volcanic rocks and potassic granites as well as the clockwise hybrid ITD and IBC P-T paths of the HP granulites may reveal that the tectonic setting in Northwest Hebei was in a transition stage from a subduction-related compressional regime to an extensional regime related to plate rollback.

  7. Seismic images of an extensional basin, generated at the hangingwall of a low-angle normal fault: The case of the Sansepolcro basin (Central Italy)

    Science.gov (United States)

    Barchi, Massimiliano R.; Ciaccio, Maria Grazia

    2009-12-01

    The study of syntectonic basins, generated at the hangingwall of regional low-angle detachments, can help to gain a better knowledge of these important and mechanically controversial extensional structures, constraining their kinematics and timing of activity. Seismic reflection images constrain the geometry and internal structure of the Sansepolcro Basin (the northernmost portion of the High Tiber Valley). This basin was generated at the hangingwall of the Altotiberina Fault (AtF), an E-dipping low-angle normal fault, active at least since Late Pliocene, affecting the upper crust of this portion of the Northern Apennines. The dataset analysed consists of 5 seismic reflection lines acquired in the 80s' by ENI-Agip for oil exploration and a portion of the NVR deep CROP03 profile. The interpretation of the seismic profiles provides a 3-D reconstruction of the basin's shape and of the sedimentary succession infilling the basin. This consisting of up to 1200 m of fluvial and lacustrine sediments: this succession is much thicker and possibly older than previously hypothesised. The seismic data also image the geometry at depth of the faults driving the basin onset and evolution. The western flank is bordered by a set of E-dipping normal faults, producing the uplifting and tilting of Early to Middle Pleistocene succession along the Anghiari ridge. Along the eastern flank, the sediments are markedly dragged along the SW-dipping Sansepolcro fault. Both NE- and SW-dipping faults splay out from the NE-dipping, low-angle Altotiberina fault. Both AtF and its high-angle splays are still active, as suggested by combined geological and geomorphological evidences: the historical seismicity of the area can be reasonably associated to these faults, however the available data do not constrain an unambiguous association between the single structural elements and the major earthquakes.

  8. Sedimentary Record of the Back-Arc Basins of South-Central Mexico: an Evolution from Extensional Basin to Carbonate Platform.

    Science.gov (United States)

    Sierra-Rojas, M. I.; Molina-Garza, R. S.; Lawton, T. F.

    2015-12-01

    The Lower Cretaceous depositional systems of southwestern Oaxaquia, in south-central Mexico, were controlled by tectonic processes related to the instauration of a continental arc and the accretion of the Guerrero arc to mainland Mexico. The Atzompa Formation refers to a succession of conglomerate, sandstone, siltstone, and limestone that crop out in southwestern Mexico with Early Cretaceous fauna and detrital zircon maximum depositional ages. The sedimentary record shows a transition from early fluvial/alluvial to shallow marine depositional environments. The first stage corresponds to juvenile fluvial/alluvial setting followed by a deep lacustrine depositional environment, suggesting the early stages of an extensional basin. The second stage is characterized by anabranched deposits of axial fluvial systems flowing to the NE-SE, showing deposition during a period of rapid subsidence. The third and final stage is made of tidal deposits followed, in turn, by abrupt marine flooding of the basin and development of a Barremian-Aptian carbonate ramp. We interpret the Tentzo basin as a response to crustal extension in a back-arc setting, with high rates of sedimentation in the early stages of the basin (3-4 mm/m.y), slower rates during the development of starved fluvial to tidal systems and carbonate ramps, and at the top of the Atzompa Formation an abrupt deepening of the basin due to flexural subsidence related to terrane docking and attendant thrusting to the west. These events were recorded in the back-arc region of a continental convergent margin (Zicapa arc) where syn-sedimentary magmatism is indicated by Early Cretaceous detrital and volcanic clasts from alluvial fan facies west of the basin. Finally, and as a response to the accretion of the Guerrero superterrane to Oaxaquia during the Aptian, a carbonate platform facing toward the Gulf of Mexico was established in central to eastern Oaxaquia.

  9. Ordovician appinites in the Wugongshan Domain of the Cathaysia Block, South China: Geochronological and geochemical evidence for intrusion into a local extensional zone within an intracontinental regime

    Science.gov (United States)

    Zhong, Yufang; Ma, Changqian; Liu, Lei; Zhao, Junhong; Zheng, Jianping; Nong, Junnian; Zhang, Zejun

    2014-06-01

    Palaeozoic mafic igneous rocks are potentially significant in constraining the tectonic nature and evolution of the Kwangsian Orogeny in the eastern South China Block, yet they have received little attention because of their limited outcrop. Geochemistry and geochronology was carried out on newly identified Ordovician ultramafic-mafic appinites in the Wugongshan Domain of the Cathaysia Block. Seven appinite samples yielded 206Pb/238U crystallisation ages ranging from 452 ± 4 Ma to 473 ± 3 Ma. Abundant 480-500 Ma zircon xenocrysts and/or inherited zircons were found in the appinites, possibly indicating an earlier magmatism episode in the early Palaeozoic period. The Wugongshan appinites are ultramafic to mafic in composition, and the ultramafic rocks display features of cumulates (high concentrations of MgO, Fe2O3t, Cr, Ni, and low concentrations of total alkali and total rare earth elements [REE]). The appinite geochemistry displays: relatively flat chondrite normalised REE patterns with slight enrichment in light REE and weak negative Eu anomalies; enrichment in large-ion lithophile elements (such as Rb, K), and weak depletion in Nb-Ta in primitive mantle normalised trace element patterns. We suggest that the Wugongshan appinites likely originated from an ancient metasomatised mantle, and that crustal assimilation, fractional crystallisation (AFC), magma mingling and hydration were involved in the petrogenetic process, based on the combination of geochemistry, crust-like bulk Sr, Nd and zircon Hf isotopic compositions (εNd (t) = - 8.2 to - 3.2, initial 87Sr/86Sr ratios of 0.7067-0.7144, zircon εHf (t) values peaking at - 9 to - 3) and regional geological data. Further considering the alignment and chronology of the appinites, we suggest that the appinitic magmas probably were emplaced along the Jiangshan-Shaoxing Fault in a local extensional zone in an intracontinental regime in the early Palaeozoic.

  10. Weighing the Oligocene extensional event in the Salar de Atacama Basin by analysis of depth-converted sections and geophysical data.

    Science.gov (United States)

    Bascunan, S. A.; Maksymowicz, A.; Martínez, F.; Becerra, J.; Rubilar, J. F.; Arriagada, C.; Peña Gomez, M. A.; Gómez, I.

    2016-12-01

    Multiple studies of industry seismic lines across the Salar de Atacama Basin, in the Central Andes of northern Chile (22°-24°S), have led to opposite interpretations regarding its internal architecture, particularly for the Cenozoic successions. These differences can be attributed to the yet uncertain stratigraphy of the 5425 m-deep Toconao-1 well, its relation to outcrops around the El Bordo Escarpment, the tie between the well and the seismic lines, and the lack of a depth conversion of these lines. An analysis of these data allows for the proper location in the depth domain of the most important reflectors found in line Z-1G010, which intersects the borehole. The vertical seismic profile and the density log show that the most significant change in lithological properties occurs at ca. 1 s TWT (1580 m), at the transition from mainly evaporitic deposits to more clastic units, presumably belonging to the Loma Amarilla Formation. This modification in velocity and density can be seen in the seismic line as a major west-dipping surface, dubbed the San Pedro Reflector (SPR). The use of 3D software and the depth conversion allow following the SPR along most of the basin. The surface shows an east-to-west, south-to-north increase in depth, reaching a maximum close to 8 km. The geometry of the surface closely follows the trend of the El Bordo Escarpment. Based on paleomagnetic data, recent mapping and geochronology data, the reflector is estimated to have formed during the Oligocene. Additional extensional features confirm its origin due to small-scale collapse of the Cordillera de Domeyko after the Eocene Incaic Event, after which the deformation front migrated eastwards, thus explaining the presence of extension and compression along the margin at the same time. This change in stress state also affected other parts of the range, such as the Calama Basin.

  11. Extensional dynamics of viscoplastic filaments

    Science.gov (United States)

    Slim, Anja; Balmforth, Neil; Dubash, Neville

    2009-11-01

    A one-dimensional slender-thread model is used to explore viscoplastic dripping under gravity and the controlled extension of a liquid bridge. We describe dynamics up to pinch-off and consider the possibility of using measurements in the two configurations (eg. drop volume) to infer rheological parameters. The model results are compared with experiments using aqueous solutions of Carbopol and kaolin suspensions.

  12. The role of long-term strain history on the generation and amplification of inherited heterogeneities in continental lithosphere extensional settings

    Science.gov (United States)

    Morena Salerno, V.; Capitanio, Fabio A.

    2017-04-01

    heterogeneities by calculating localization indexes for all the models at the onset of the second rifting event. This calculation embeds the inherited rheology from the previous rift event. We show that the lithosphere progressively localises along the inherited heterogeneities leading to the formation of various rift basin types, ranging from narrow to wide to hyperextended and with variation degrees of symmetry. Our result show that rift basin types and structural styles are strongly affected by inherited heterogeneities generated from previous rifting events, showing cases in which the previous strain history cannot be neglected. The subsidence patterns and melt production result to be very sensitive to the strain history, the type of inherited heterogeneities and their interplay with variation of boundary displacement velocity. Our numerical simulations replicate the first-order features of rift basins and provide a general framework to assess the inherited heterogeneities' role in the interpretation of extensional basins and their evolution.

  13. Relating titanium distribution and stable isotope thermometry to quartz microstructure in an extensional detachment system, Shuswap metamorphic core complex, British Columbia

    Science.gov (United States)

    Nachlas, W. O.; Seaton, N. C.; Whitney, D. L.; Teyssier, C.; Mulch, A.; Grove, M.

    2010-12-01

    Microstructural and textural observations in deformed rocks can be used to interpret the thermal history and rheological behavior of extensional shear zones. The interaction between deformation and dynamic recrystallization of individual mineral phases controls the preserved microstructures and provides insight into the physical and chemical response to plastic deformation. The accommodation of internal strain within a deformed mineral through the migration of lattice dislocations produces textural features that are indicative of deformation conditions. Mechanisms of dislocation creep are intimately linked to the mobility and distribution of trace elements within a dynamically recrystallized grain and can be used to interpret the temperature conditions of deformation. The Shuswap metamorphic core complex is a migmatite-cored gneiss dome situated within the Omineca crystalline belt of southern British Columbia. Exhumation of the dome was accommodated by a brittle-ductile detachment system localized within a thick (~800 m) sequence of quartzite mylonite. The quartzite is characterized by large elongate quartz ribbons locally mantled by recrystallized subgrains which preserve similar grain size between the three samples of interest. Detailed crystallographic preferred orientation measurements (EBSD) coupled with high resolution ion microprobe (SHRIMP-RG) analysis of quartz provides insight into the thermal evolution of quartz microstructure. Titanium concentration varies systematically both within single grains and between different structural levels in the detachment. Within the samples analyzed, a pattern of decreasing Ti content from core to recrystallized rim remains consistent regardless of the absolute concentration. The Ti values vary as follows, core/rim: 7-9.5 ppm/4.5-6.5 ppm; 11-14 ppm/7.5-10 ppm; 17-20 ppm/13-16 ppm. Intra-grain Ti content varies systematically with cathodoluminescence intensity and can be used to thermally track dynamic recrystallization

  14. Active faulting, 3-D geological architecture and Plio-Quaternary structural evolution of extensional basins in the central Apennine chain, Italy

    Science.gov (United States)

    Gori, Stefano; Falcucci, Emanuela; Ladina, Chiara; Marzorati, Simone; Galadini, Fabrizio

    2017-03-01

    legacy must be considered in a wider evolutionary perspective. Our results testify that a large-scale basin and range geomorphological feature - often adopted for morpho-tectonic and kinematic evaluations in active extensional contexts, as in the Apennines - just led by range-bounding active normal faults may be actually simplistic, as it could not be applied everywhere, owing to peculiar complexities of the local tectonic histories.

  15. Superimposed basin formation during Neogene-Quaternary extensional tectonics in SW-Anatolia (Turkey): Insights from the kinematics of the Dinar Fault Zone

    Science.gov (United States)

    Alçiçek, M. Cihat; Brogi, Andrea; Capezzuoli, Enrico; Liotta, Domenico; Meccheri, Marco

    2013-11-01

    In the extensional province of SW-Anatolia, the cross-cutting relationship between the NW- and NE-oriented Neogene and Quaternary basins is an ongoing debate in the understanding of the tectonic evolution of this area. In order to contribute to this issue, we carried out a structural and kinematic study along the seismogenic NW-trending Dinar Fault Zone (DFZ). This structure was initially controlled by the sedimentary and tectonic evolution of the NE-oriented Neogene Baklan, Acıgöl and Burdur basins and, later, by the NW-oriented Quaternary Dinar Basin. On the basis of > 1000 structural and kinematic data, in conjunction with basin stratigraphy, the DFZ can be divided into three almost parallel and continuous bands, that are: (a) the Hangingwall where Quaternary sediments are deformed by normal faults with mechanical striations; (b) the Inner Zone, corresponding to the present Dinar fault scarp, where NW-trending normal faults with mechanical striations are dominant, and (c) the Outer Zone, located in the footwall of the structure comprising the area between the fault scarp and undeformed bedrock, where faults exhibit variable orientation and kinematics, from strike-slip to normal dip-slip. These kinematics are mainly indicated by calcite shear veins and superimposed mechanical striations, respectively. This suggests that the DFZ changed kinematics over time, i.e., the DFZ initiated as dominant dextral strike-slip to oblique-slip fault system and continued with a dominant normal movement. Therefore, we hypothesize that the NW-trending DFZ was initially a transfer zone during the late Miocene-Pliocene, coeval to the sedimentary and structural evolution of the NE-trending Baklan, Acigöl and Burdur basins. During the Quaternary the DFZ, representing an already weakened crustal sector, played the role of a normal fault system providing the accommodation space for the Quaternary Dinar Basin. Hydrothermal circulation and volcanism at NE-/NW-trending faults

  16. Insights on the seismotectonics of the western part of northern Calabria (southern Italy) by integrated geological and geophysical data: Coexistence of shallow extensional and deep strike-slip kinematics

    Science.gov (United States)

    Ferranti, L.; Milano, G.; Pierro, M.

    2017-11-01

    We assess the seismotectonics of the western part of the border area between the Southern Apennines and Calabrian Arc, centered on the Mercure extensional basin, by integrating recent seismicity with a reconstruction of the structural frame from surface to deep crust. The analysis of low-magnitude (ML ≤ 3.5) events occurred in the area during 2013-2017, when evaluated in the context of the structural model, has revealed an unexpected complexity of seismotectonics processes. Hypocentral distribution and kinematics allow separating these events into three groups. Focal mechanisms of the shallower (< 9 km) set of events show extensional kinematics. These results are consistent with the last kinematic event recorded on outcropping faults, and with the typical depth and kinematics of normal faulting earthquakes in the axial part of southern Italy. By contrast, intermediate ( 9-17 km) and deep ( 17-23 km) events have fault plane solutions characterized by strike- to reverse-oblique slip, but they differ from each other in the orientation of the principal axes. The intermediate events have P axes with a NE-SW trend, which is at odds with the NW-SE trend recorded by strike-slip earthquakes affecting the Apulia foreland plate in the eastern part of southern Italy. The intermediate events are interpreted to reflect reactivation of faults in the Apulia unit involved in thrust uplift, and appears aligned along an WNW-ESE trending deep crustal, possibly lithospheric boundary. Instead, deep events beneath the basin, which have P-axis with a NW-SE trend, hint to the activity of a deep overthrust of the Tyrrhenian back-arc basin crust over the continental crust of the Apulia margin, or alternatively, to a tear fault in the underthrust Apulia plate. Results of this work suggest that extensional faulting, as believed so far, does not solely characterizes the seismotectonics of the axial part of the Southern Apennines.

  17. The Late Cretaceous I- and A-type granite association of southeast China: Implications for the origin and evolution of post-collisional extensional magmatism

    Science.gov (United States)

    Zhao, Jiao-Long; Qiu, Jian-Sheng; Liu, Liang; Wang, Rui-Qiang

    2016-01-01

    , leaving a granulite residue in the lower crust. Both the I- and A-type granites were emplaced during post-collisional extensional tectonism associated with rollback of the steeply subducting paleo-Pacific Plate. An increase of the dip angle of the subducted palaeo-Pacific plate between the Early and Late Cretaceous resulted in enhanced extension, further thinning the lithosphere and causing more intensive underplating of mantle-derived magmas. This generated high temperatures and caused the partial melting of the residual granulite material, producing relatively anhydrous F-bearing felsic melts. The mixing of these unusual crustal melts with more voluminous mantle-derived mafic magmas generated the parental magmas that eventually formed the peralkaline A-type granites.

  18. Shallow burial dolomitisation of Middle-Upper Permian paleosols in an extensional tectonic context (SE Iberian Basin, Spain): Controls on temperature of precipitation and source of fluids

    Science.gov (United States)

    Benito, M. Isabel; De la Horra, Raúl; López-Gómez, José; Barrenechea, José F.; Luque, Javier; Arche, Alfredo

    2011-06-01

    around 16 and 25 °C cooler, respectively. In addition, the δ 18O VSMOW values of the water from which dolomite precipitated would have ranged between - 0.3 and - 2.9‰. Dolomite is partially or totally replaced by non- to dark dull luminescent magnesite in the Landete and Talayuelas sections. Magnesite crystals are affected by stylolites, indicating that it precipitated before chemical compaction. The δ 13C mean values are - 6.5 and - 6.0‰ and the δ 18O VPDB mean values are - 6.7 and - 7.8‰, in the Landete and Talayuelas sections, respectively. The 87Sr/ 86Sr ratios of magnesite are similar in both sections yielding values between 0.71258 and 0.72508. This suggests that they probably precipitated from similar fluids during progressive burial and at higher temperatures than dolomites at the same sections. Assuming that magnesite precipitated from a fluid with similar δ 18O values in both sections, then it had to precipitate at a temperature around 8 °C higher in Talayuelas than in the Landete section. Dolomitisation and magnesite precipitation probably occurred via reflux of saline to hypersaline brines from the overlying Mid-Late Triassic Muschelkalk and/or Keuper facies. The temperatures inferred for dolomite precipitation, however, are too high for shallow burial if a normal geothermal gradient is applied. Thus, it can be inferred that saline fluids were heated as they flowed through the syn-sedimentary extensional faults that controlled Middle Permian to Middle Triassic sedimentation; consequently fluids would have been at higher temperatures near the Henarejos area, which was closer to the basin boundary fault than at the Talayuelas and Landete areas, which were situated further away. This contention is in agreement with recent studies which demonstrate that an important thermal event took place during Late Triassic-Early Jurassic times in the Iberian Peninsula.

  19. Impact of pre- and/or syn-tectonic salt layers in the hangingwall geometry of a kinked-planar extensional fault: insights from analogue modelling and comparison with the Parentis basin (bay of Biscay)

    Science.gov (United States)

    Ferrer, O.; Vendeville, B. C.; Roca, E.

    2012-04-01

    Using sandbox analogue modelling we determine the role played by a pre-kinematic or a syn-kinematic viscous salt layer during rollover folding of the hangingwall of a normal fault with a variable kinked-planar geometry, as well as understand the origin and the mechanisms that control the formation, kinematic evolution and geometry of salt structures developed in the hangingwall of this fault. The experiments we conducted consisted of nine models made of dry quartz-sand (35μm average grain size) simulating brittle rocks and a viscous silicone polymer (SMG 36 from Dow Corning) simulating salt in nature. The models were constructed between two end walls, one of which was fixed, whereas the other was moved by a motor-driven worm screw. The fixed wall was part of the rigid footwall of the model's master border fault. This fault was simulated using three different wood block configurations, which was overlain by a flexible (but not stretchable) sheet that was attached to the mobile endwall of the model. We applied three different infill hangingwall configurations to each fault geometry: (1) without silicone (sand only), (2) sand overlain by a pre-kinematic silicone layer deposited above the entire hanginwall, and (3) sand partly overlain by a syn-kinematic silicone layer that overlain only parts of the hangingwall. All models were subjected to a 14 cm of basement extension in a direction orthogonal to that of the border fault. Results show that the presence of a viscous layer (silicone) clearly controls the deformation pattern of the hangingwall. Thus, regardless of the silicone layer's geometry (either pre- or syn-extensional) or the geometry of the extensional fault, the silicone layer acts as a very efficient detachment level separating two different structural styles in each unit. In particular, the silicone layer acts as an extensional ductile shear zone inhibiting upward propagation of normal faults and/or shears bands from the sub-silicone layers. Whereas the

  20. Verbos de desplazamiento en español y en chino: Un análisis subléxico de su significado y sus extensiones semánticas

    OpenAIRE

    Luo, Ying

    2016-01-01

    Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Filosofía y Letras, Departamento de Lingüística General, Lenguas Modernas, Lógica y Filosofía de la Ciencia, Teoría de la Literatura y Literatura Comparada. Fecha de lectura: 18 de febrero de 2016 Esta tesis ha estudiado de manera exhaustiva las extensiones semánticas regulares de los verbos de desplazamiento en español salir y entrar y sus equivalentes en chino chū (‘salir’) y jìn/rù (‘entrar’) desde una persp...

  1. ESTUDO PROSPECTIVO DA PRÓPOLIS E TECNOLOGIAS CORRELATAS SOB O ENFOQUE EM DOCUMENTOS DE PATENTES DEPOSITADOS NO BRASIL

    Directory of Open Access Journals (Sweden)

    Bruna Aparecida Souza Machado

    2012-09-01

    Full Text Available A própolis é um produto natural elaborado a partir de secreções de árvores, flores, folhas e pólen, recebendo ainda a adição de substâncias secretadas pelo metabolismo glandular das abelhas. Devido à importância farmacológica, terapêutica, científica e econômica deste produto, o objetivo deste trabalho foi analisar as potencialidades, características e evolução das competências tecnológicas, traduzidas através de dados estatísticos de patentes depositados no Brasil, no que diz respeito aos processos de extração e obtenção de compostos ativos da própolis, bem como suas aplicações industriais a partir da elaboração de novos produtos. O termo documento de patente abrange pedidos de patente publicados ou patentes concedidas. A pesquisa foi realizada a partir de palavras-chave do tema na base de dados do Instituto Nacional de Propriedade Industrial. O primeiro documento de patente identificado foi de 1992, tendo como o país de origem o Japão. Do universo de patentes depositadas 94% são de residentes e 6% de não residentes. Em relação à tecnologia protegida os inventores independentes são os maiores depositantes, seguida das empresas e universidades. Apesar de o Brasil ser um dos maiores exportadores mundiais da própolis, este não é considerado como um mercado atraente e competitivo para a proteção desta tecnologia por outros países.

  2. Tratamento do blefaroespasmo e distonias faciais correlatas com toxina botulínica: estudo de 16 casos

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    Carvalho Roberto Murillo Limongi de Souza

    2003-01-01

    Full Text Available OBJETIVO: Analisar a eficácia do tratamento com Botox® e estudar o comportamento destes pacientes após aplicações sucessivas, dando ênfase ao possível efeito de tolerância após o uso prolongado deste medicamento. MÉTODOS: Foi realizado estudo prospectivo em 16 pacientes com distonias faciais no ambulatório de Oftalmologia, no Setor de Plástica Ocular do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, entre abril de 1998 a março de 1999. Todos os pacientes foram submetidos ao exame oftalmológico completo, neurológico e tomografia computadorizada de crânio. Os pacientes com sintomas importantes de espasmo foram tratados com aplicação da toxina botulínica tipo A (Botox®. Dez pacientes eram do sexo feminino. A idade média foi 64,75 anos. RESULTADOS: Dentre as distonias faciais, o espasmo hemifacial foi o mais encontrado, num total de 8 pacientes.O índice de sucesso do Botox®foi de 87,5 %, com duração média do efeito de 30 a 90 dias, variando de acordo com o número de aplicações. CONCLUSÕES: O tratamento dos espasmos faciais com a toxina botulínica mostrou-se eficaz em 87,5 % de nossos pacientes.

  3. Entangled Polymer Melts in Extensional Flow

    DEFF Research Database (Denmark)

    Hengeller, Ludovica

    monitor macromolecular chain orientation associated with induced flow fields. This work concerns linear and non-linear rheology of polystyrene melts and solutions coupled with neutron scattering experiments. The aim of this thesis is to investigate theextensional properties of well characterized polymer......, and the particular design of the oven meets the requirement of fast cooling of the sample, so that it can freeze the particularmolecular orientation of the chains at different stages of the stretching or relaxing ofthe sample....

  4. Constant force extensional rheometry of polymer solutions

    DEFF Research Database (Denmark)

    Szabo, Peter; McKinley, Gareth H.; Clasen, Christian

    2012-01-01

    We revisit the rapid stretching of a liquid filament under the action of a constant imposed tensile force, a problem which was first considered by Matta and Tytus [J. Non-Newton. Fluid Mech. 35 (1990) 215–229]. A liquid bridge formed from a viscous Newtonian fluid or from a dilute polymer solution...

  5. Upright folding during extensional and transtensional tectonics

    Science.gov (United States)

    Teyssier, Christian; Fossen, Haakon; Rey, Patrice F.; Whitney, Donna L.

    2017-04-01

    Upright folds are common structures that develop in response to horizontal shortening in layered material, for example in foreland basins that surround orogens. While the contractional nature of these folds is not in doubt, interpretation of their tectonic setting needs careful consideration. Here we focus on two examples: (1) folds developed in transtension; and (2) folds developed during the flow of deep crust in response to lithospheric extension. In both cases we consider folding of nearly horizontal layers that are either primary (bedding) or secondary (foliation). Strain theory inspired by John Ramsay's work makes predictions for the behavior of material lines and planes as well as strain axes (instantaneous, finite) during transtensional deformation. Results show: folds can form in transtension; fold hinges rotate toward the direction of divergence (and not the shear zone boundary as they do in transpression), providing unique insight into ancient plate motions; fold tightness is controlled by the obliquity of divergence and not finite strain; hinge parallel stretching is always greater than hinge-perpendicular shortening, resulting in constriction strain and boudinage of fold hinges. Taken together these results provide a rigorous framework for interpreting field observations where structures are complex and boundary conditions unclear. These principles are applied to various tectonic settings ranging from active tectonic regions of oblique divergence in western North America to ancient folding that developed during oblique extension of the Western Gneiss Region, deposition of Devonian basins, and exhumation of ultrahigh-pressure rocks in the Norwegian Caledonides. The other class of upright folds that form during extension may require revision of the tectonic interpretation of structural overprints in orogenic cores, for example in gneiss/migmatite domes. Dynamic modeling of extension of thick/hot crust predicts a positive feedback between extension of shallow crust (low-angle detachment system) and flow of low-viscosity (partially molten) deep crust. As the low-viscosity crust converges toward the zone of extension, it forms two crustal-scale upright to slightly inclined folds that eventually, in three dimensions, define two elongate domes. These contraction structures develop while the lithosphere undergoes extension. As it flows toward the zone of extension, deep crust material is incorporated into a contractional domain located directly beneath the zone of shallow crust extension, forming two domes of foliation separated by a high strain zone. This double-dome and high strain zone accommodate rapid exhumation of the deep crust, which then enters a domain of extension as it reaches the base of the shallow crust. Therefore, structural and metamorphic history indicates that high-pressure contraction is overprinted by low-pressure extension under nearly isothermal conditions. Geologic observations, for example in the Montagne Noire double dome (Massif Central, France), indicate that upright folds in the core of domes formed during extension of the units that mantle the dome. These folds/domes have significant exhuming power since eclogite that crystallized at the onset of extension is found in blocks and pods in the migmatite dome, indicating > 30 km of exhumation.

  6. Brazilian Policy and the Creation of a Regional Security Complex in the South Atlantic: Pax Brasiliana?

    Directory of Open Access Journals (Sweden)

    Beatriz Rodrigues Bessa Mattos

    Full Text Available Abstract Over the past five years, the South Atlantic region has become a central element of Brazilian security policy, with Brazil actively supporting the notion of a trans-oceanic security consciousness involving African littoral states. It has invested in diplomatic initiatives such as the Zone of Peace and Cooperation of the South Atlantic (ZPCSA, or ZOPACAS, and extensive military co-operation with West African states such as São Tomé e Príncipe, Namibia and Cape Verde. Its internal security and defence policy documents have repeatedly been updated to reflect this dimension, and now provide the foundation for advancing these initiatives. This policy thrust is directed at securing Brazil’s offshore oil assets, and limiting the influence of what it has termed ‘extra-regional powers’ such as the P-5. This article highlights these initiatives and reviews the prospects for this policy by examining the plausibility of the South Atlantic region as a regional security complex in the sense coined by Buzan and Wæver. The analysis is based on the role of geographical and linguistic proximity in international relations, and the impact of multilateral bodies on building support for a regional approach to security governance.

  7. Mecanismos envolvidos na biodegradação de materiais lignocelulósicos e aplicações tecnológicas correlatas

    OpenAIRE

    André Aguiar; André Ferraz

    2011-01-01

    The biodegradation of lignocellulosic materials is an important natural process because it is responsible for the carbon recycling. When induced under controlled conditions, this process can be used for technological applications such as biopulping, biobleaching of cellulosic pulps, pre-treatment for subsequent saccharification and cellulosic-ethanol production, and increase of the digestibility in agroindustrial residues used for animal feed. In the present work, the enzymatic and non-enzyma...

  8. Grain-size effects on the closure temperature of white mica in a crustal-scale extensional shear zone - Implications of in-situ 40Ar/39Ar laser-ablation of white mica for dating shearing and cooling (Tauern Window, Eastern Alps)

    Science.gov (United States)

    Scharf, Andreas; Handy, Mark R.; Schmid, Stefan M.; Favaro, Silvia; Sudo, Masafumi; Schuster, Ralf; Hammerschmidt, Konrad

    2016-04-01

    In-situ 40Ar/39Ar laser ablation dating of white-mica grains was performed on samples from the footwall of a crustal-scale extensional fault (Katschberg Normal Fault; KNF) that accommodated eastward orogen-parallel displacement of Alpine orogenic crust in the eastern part of the Tauern Window. This dating yields predominantly cooling ages ranging from 31 to 13 Myr, with most ages clustering between 21 and 17 Myr. Folded white micas that predate the main Katschberg foliation yield, within error, the same ages as white-mica grains that overgrow this foliation. However, the absolute ages of both generations are older at the base (20 Myr) where their grain size is larger (300-500 μm), than at the top and adjacent to the hangingwall (17 Myr) of this shear zone where grain size is smaller (new data show that rapid cooling within the KNF of the eastern Tauern Window started sometime before 21 Myr according to the 40Ar/39Ar white-mica cooling ages and between 25-21 Myr according to the new Rb/Sr white-mica ages, i.e., shortly after the attainment of the thermal peak in the Tauern Window at 25 Myr ago. These new data, combined with literature data, support earlier cooling in the eastern part of then Tauern Window than in the western part by some 3-5 Myr.

  9. Quantifying sedimentation in extensional basins and magmatism during continental collision

    NARCIS (Netherlands)

    Andrić, N.

    2017-01-01

    Continental collision is one of the main tectonic processes responsible for the formation of mountain ranges and plays an important role in the overall crustal growth, i.e. in the creation of new crust. Understanding the processes operating during continental collision demands an integrated approach

  10. Extensiones áulicas. Una oportunidad para seguir aprendiendo

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    Miriam Gelli

    2014-12-01

    Full Text Available El 5 de mayo de 1988 la Facultad de Ciencias Económicas y Estadística de la Universidad Nacional de Rosario comenzó a dictar la carrera de Contador Público en la ciudad San Nicolás. Fue éste un hecho importante para los jóvenes de esa localidad y su vasta zona de influencia. Así comenzó a desarrollar estrategias de inclusión en el sistema universitario que, a partir de la experiencia en San Nicolás, luego replicaría en otras localidades de la región centro de la Argentina. Habitualmente se considera a la educación como el principal mecanismo de reducción de desigualdades en el futuro y de superación de la reproducción intergeneracional de la pobreza, dado los círculos virtuosos existentes entre mayor educación, movilidad socio-ocupacional y más ingresos. El objetivo de esta nota es analizar cómo la Facultad ha superado los obstáculos que se observan en el acceso a la educación superior con el trabajo desarrollado junto con actores e instituciones de comunidades vecinas en pos de la igualdad de oportunidades para seguir aprendiendo.

  11. Carbonate pseudotachylite? from a Miocene extensional detachment, W. Cyclades, Greece.

    Science.gov (United States)

    Rice, A. Hugh N.; Grasemann, Bernhard

    2016-04-01

    Most pseudotachylites, both impact- and fault-related, occur in silicate-rich rocks, typically with 'granitoid' compositions. Examples of melting in carbonate rocks, excluding magmatic sources, are restricted to impact-events, except for a carbonate pseudotachylite in the Canalone Fault, S. Italy (Viganò et al. 2011). Another potential example of carbonate pseudotachylite, shown here, comes from the Miocene-aged W. Cycladic Detachment System, in Greece. Top-SSE ductile to brittle movement on this detachment, with a maximum displacement estimated at tens of kilometers, exhumed of HP-rocks. The carbonate pseudotachylite occurs within an 43 mm thick), consists of dark (hematitic) red, ultra-fine grained unlayered carbonate with up to 40x10 mm rather rounded clasts of earlier generations of cataclasite, many with a quartzite composition. These clasts are fractured and partially separated, with a fine red carbonate matrix. No layering of the matrix or clasts is apparent. The clasts become finer and more abundant towards the boundary with Layer B. Layers B and D (~57 & ~20 mm thick) dominantly comprises protocataclasite with greyish quartz fragments separated by a carbonate matrix along narrow fractures. Zone C and E (~23 m & >15 mm thick) comprise pale pink carbonate-dominated rocks with abundant clasts (+/- quartz fragments) of earlier cataclasite generations. These elongate clasts lie parallel to the overall banding, which is parallel to the ultramylonitic foliation (detachment surface). Smaller clasts are markedly more rounded and comprise carbonate and quartzite material and may have darker (?reaction) rims. No layering is seen in the pale pink groundmass although this is present in some elongate clasts. All layer boundaries are irregular and no principle slip surfaces have been seen. Injection veins from 1 to 9 mm wide and up to at least 100 mm long derive from the central layer (C), cutting the overall layering at a high angle and branching in several places. These veins contain clasts comparable to those in Layer C. Both thick and thin injection-veins are rimmed by impersistent white calcite suggesting that injection was associated with precipitation of calcite. Whether Layer C (and perhaps E also) is a carbonate pseudotachylite is unknown. Although the injection veins are suggestive of this, these also occur in conjunction with ultracataclasites (Craddock et al. 2012). The irregular boundaries between the layers and the lack of any principal slip surfaces might indicate decarbonation and/or fluidization of gouge layer (Rowe and Griffith, 2015). Finally, abundant tubules, with rounded profiles and mostly sub-circular shapes up to 1.2 mm across, occur in Layers C and E, and less so D; these could be interpreted to reflect vents formed by partial carbonate degassing during melting.

  12. Extensional versus Intuitive Reasoning: The Conjunction Fallacy in Probability Judgment.

    Science.gov (United States)

    Tversky, Amos; Kahneman, Daniel

    1983-01-01

    Judgments under uncertainty are often mediated by intuitive heuristics that are not bound by the conjunction rule of probability. Representativeness and availability heuristics can make a conjunction appear more probable than one of its constituents. Alternative interpretations of this conjunction fallacy are discussed and attempts to combat it…

  13. Extensional Flow-Induced Dynamic Phase Transitions in Isotactic Polypropylene.

    Science.gov (United States)

    Ju, Jianzhu; Wang, Zhen; Su, Fengmei; Ji, Youxin; Yang, Haoran; Chang, Jiarui; Ali, Sarmad; Li, Xiangyang; Li, Liangbin

    2016-09-01

    With a combination of fast extension rheometer and in situ synchrotron radiation ultra-fast small- and wide-angle X-ray scattering, flow-induced crystallization (FIC) of isotactic polypropylene (iPP) is studied at temperatures below and above the melting point of α crystals (Tmα). A flow phase diagram of iPP is constructed in strain rate-temperature space, composing of melt, non-crystalline shish, α and α&β coexistence regions, based on which the kinetic and dynamic competitions among these four phases are discussed. Above Tmα , imposing strong flow reverses thermodynamic stabilities of the disordered melt and the ordered phases, leading to the occurrence of FIC of β and α crystals as a dynamic phase transition. Either increasing temperature or stain rate favors the competiveness of the metastable β over the stable α crystals, which is attributed to kinetic rate rather than thermodynamic stability. The violent competitions among four phases near the boundary of crystal-melt may frustrate crystallization and result in the non-crystalline shish winning out. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Detecting and Reporting Extensional Concept Drift in Statistical Linked Data

    NARCIS (Netherlands)

    Meroño-Peñuela, A.; Guéret, C.; Hoekstra, R.; Schlobach, S.

    2013-01-01

    The RDF Data Cube vocabulary is a catalyst for the availability of statistical Linked Data: raw statistical Linked Data are easy to model in, publish to, and retrieve from the Linked Data cloud. In statistical datasets, concepts are central entities represented by variables and their values. The

  15. Tectonic and Geomporphic Overview of the Ross Embayment Extensional Province

    Science.gov (United States)

    Wilson, D. S.

    2016-12-01

    The Ross Embayment is one of the lowest-standing continental regions on Earth. In essentially all places where basement topography has been mapped, the morphology is horst and graben. Several authors have suggested that the low topography is recent, with the area having been an orogenic highland in the Cretaceous. The tectonic extension driving the transition from high topography to low topography may have been as much as 500 km, with stretching factors of 2-3 over wide areas. Timing of the extension is incompletely known, but may have spanned most of the interval from 100 to 25 Ma. An analogy between the Ross Embayment and the North American Basin and Range province has often been suggested, and the case for that analogy has been growing. North American orogenic topography was probably highest 50 Ma, and margin-normal extension has been of the order of 200 km, and is ongoing. The Transantarctic Mountains bordering the Ross Embayment may share elements of their formation with the Wasatch Mountains of Utah and other parts of the eastern boundary of the Basin and Range. Glacial erosion and deposition have played a huge role in the geomorphic history of the Ross Embayment. The source region for the major ice streams, now well below sea level even after accounting for removal of the present ice load, restores with confidence to above sea level in the Eocene after accounting for the effects of 2 km of erosion and of thermal subsidence. The scale of these topographic changes is large enough that they need to be considered in detailed simulations of past climates, especially the initiation of the Antarctic ice sheets. Under generous interpretations of early Cenozoic tectonic extension in the Ross Embayment, the Late Cretaceous ancestral Transantarctic Mountains may have been high enough to host short-lived ice caps inferred from global sea level and oxygen-isotope records.

  16. Numerical analysis of extensional flow through the pharyngeal duct

    Science.gov (United States)

    Preciado-Méndez, M.; Salinas-Vázquez, M.; Vicente, W.; Brito-de la Fuente, E.; Ascanio, G.

    2017-01-01

    The flow through the pharynx from the glossopalatal junction (GPJ) to the upper esophageal sphincter (UES) has been numerically investigated with a non-Newtonian fluid obeying the power-law with similar rheological indices to a contrast medium used in videofluroscopy. For that purpose, a three-dimensional model of the transport of food bolus along the pharynx has been proposed using the immersed boundaries method, which allow representing the shape of the pharynx using Cartesian grids. The pharyngeal wall has been considered to be an elastic membrane. Flow fields in terms of the axial velocity, pressure, shear rate and strain rate were obtained. Results show that the highest velocity concentrates in the central stream as the fluid enters into the pharynx. In addition, as the flow quits the pharynx, a recirculation zone appears inside the cavity, resulting in low velocity zone, which increases with the coefficient of elasticity. A strong dependence on the coefficient of elasticity was observed on the pressure fields; so that as such a coefficient increases, the pressure in the pharyngeal wall will increase. It has been also observed that the bolus head travels faster than the bolus tail, which indicates that the bolus is not only subjected to shear but also to elongation. Results from this work can be further used for a rheological characterization (shear and extension) of oral nutritional supplements for patients suffering from swallowing disorders.

  17. Considerações sobre a legislação correlata à zona-tampão de unidades de conservação no Brasil Interpretation of the legislation about buffer zones of protected areas in Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia De Luca Vitalli

    2009-06-01

    Full Text Available Zonas tampão são áreas ao redor de unidades de conservação, sujeitas a normas específicas, que visam mitigar impactos sobre os ecossistemas protegidos. Analisamos os instrumentos jurídicos que tratam dessas zonas no Brasil e consideramos que podem ser classificadas como limitações ao exercício do direito de propriedade, cabendo aos gestores das unidades de conservação, juntamente com os órgãos licenciadores, indicar quais atividades devem ser submetidas ao licenciamento ambiental para que possam ser instaladas ao redor de unidades de conservação.Buffer zones are areas around natural reserves under special laws, aiming at minimizing threats to the protected ecosystems. After analyzing the Brazilian legislation concerning the subject, we interpret buffer zones as a sort of limitation to the property rights. It is in the hands of the managers of protected areas, together with the licensing institutions, to indicate which activities are potentially of great impact and must have an environmental license to be permitted in the buffer zone of protected areas.

  18. Métodos analíticos ultrasensíveis: lente térmica e técnicas correlatas Ultrasensitive analytical methods: thermal lens and related techniques

    Directory of Open Access Journals (Sweden)

    Mauricio S. Baptista

    1999-07-01

    Full Text Available Among the emergent laser based spectrometric methods, thermal lensing and other photothermal techniques present a great potential for solving a variety of problems in the fields of chemistry, physics and biology. Their main advantages are high concentration sensitivity, sensibility to physical-chemical properties of the medium, excellent spatial resolution and noninvasive characteristics. In this article, theoretical principles, main applications and practical hints as well as fundamental limitations of these techniques will be carefully described. It is hoped that this will give the reader a clear picture of this field of investigation as well as provide to the ones who are not specialists in the area, the necessary background to understand, implement and use photothermal techniques. In the final sections the development frontiers of photothermal spectrometry will be discussed.

  19. Avaliação do efeito antimicrobiano de óleos essenciais sobre micro-organismos patogênicos em vôngole (Anomalocardia brasiliana)

    OpenAIRE

    Santos, Juliana Cantalino dos

    2013-01-01

    84 f. Os óleos essenciais têm se apresentado como uma alternativa eficaz para a conservação de alimentos devido ao seu poder antimicrobiano. O objetivo deste estudo foi avaliar a atividade antibacteriana dos óleos essenciais disponíveis no comércio da marca Laszlo Aromalândia (São Paulo- Brasil), como o de alho (Allium sativum), cravo-da-índia (Eugenia caryophyllata), orégano (Origanum vulgare ssp. Hirtum) e limão siciliano (Citrus limonum medica) sobre cepas de Staphylococcus aureus e Esc...

  20. Influência de estruturas brasilianas na sismicidade desencadeada por reservatório na Usina Hidrelétrica de Irapé, Minas Gerais, Brasil

    Directory of Open Access Journals (Sweden)

    Guilherme Ferreira da Silva

    Full Text Available Inaugurada em 2006, a Usina Hidrelétrica de Irapé possui a mais alta barragem do país, com 210 m, que vem sendo monitorada pelo Observatório Sismológico da Universidade de Brasília desde o começo do enchimento de seu reservatório. Apresentando sismicidade causada pelo aumento da tensão crustal logo após o início do represamento, a Sismicidade Desencadeada por Reservatório da Usina Hidrelétrica de Irapé permanece como um importante objeto de estudo para o entendimento deste fenômeno. O presente trabalho se propôs a estudar a sismicidade registrada de janeiro a maio de 2006, assim como a caracterizar a geologia ao redor da Usina Hidrelétrica de Irapé com o intuito de identificar e descrever as estruturas que permitam melhor compreender os eventos sísmicos. A orientação espacial dos eventos sísmicos obtidos pela análise das polaridades e da forma de onda condiz com aquelas dos lineamentos de relevo. As estruturas encontradas podem ser associadas a uma maior, de direção principal NE/SW, com dezenas de quilômetros, que seria responsável pela captura dos rios Jequitinhonha e Araçuaí, interpretada neste trabalho como uma estrutura relacionada a uma fase tardia do Evento Brasiliano. O diagrama de solução do mecanismo focal gerado utilizando um método de inversão da forma de onda no domínio do tempo indica que a direção dos possíveis planos de falhas está correlacionada ao principal direcionamento das estruturas rúpteis na área de trabalho.

  1. Observing the chain stretch transition in a highly entangled polyisoprene melt using transient extensional rheometry

    DEFF Research Database (Denmark)

    Nielsen, Jens Kromann; Hassager, Ole; Rasmussen, Henrik K.

    2009-01-01

    –Edwards reptation model for Deborah numbers based on the Rouse time less than about DeR=0.04. For DeR=0.04, the stress difference follows more or less the Doi–Edwards prediction in the limit of infinite stretch rates and, for DeR>0.04, the measured stresses are well above those that can be predicted by the basic...

  2. Extensional reactivation of the Chocolate Mountains subduction thrust in the Gavilan Hills of southeastern California

    Science.gov (United States)

    Oyarzabal, F.R.; Jacobson, C.E.; Haxel, G.B.

    1997-01-01

    The NE vergent Chocolate Mountains fault of south-eastern California has been interpreted as either a subduction thrust responsible for burial and prograde metamorphism of the ensimatic Orocopia Schist or as a normal fault involved in the exhumation of the schist. Our detailed structural analysis in the Gavilan Hills area provides new evidence to confirm the latter view. A zone of deformation is present at the top of the Orocopia Schist in which lineations are parallel to those in the upper plate of the Chocolate Mountains fault but oblique to ones at relatively deep levels in the schist. Both the Orocopia Schist and upper plate contain several generations of shear zones that show a transition from crystalloblastic through mylonitic to cataclastic textures. These structures formed during retrograde metamorphism and are considered to record the exhumation of the Orocopia Schist during early Tertiary time as a result of subduction return flow. The Gatuna fault, which places low-grade, supracrustal metasediments of the Winterhaven Formation above the gneisses of the upper plate, also seems to have been active at this time. Final unroofing of the Orocopia Schist occurred during early to middle Miocene regional extension and may have involved a second phase of movement on the Gatuna fault. Formation of the Chocolate Mountains fault during exhumation indicates that its top-to-the-NE sense of movement provides no constraint on the polarity of the Orocopia Schist subduction zone. This weakens the case for a previous model involving SW dipping subduction, while providing support for the view that the Orocopia Schist is a correlative of the Franciscan Complex.

  3. Mantle temperature as a control on the time scale of thermal evolution of extensional basins

    DEFF Research Database (Denmark)

    Petersen, K. D.; Armitage, J. J.; Nielsen, S. B.

    2015-01-01

    Extension of the lithosphere, the thermo-mechanical boundary layer above the convecting mantle, is followed by cooling and subsidence. The timescale of oceanic basin subsidence is ~100 Myr whereas basins of the continental interior often subside continuously for more than 200 Myr after rifting. U...

  4. Measuring the Extensional Properties of linear and branched Polymer Melts using Membrane Inflation into a Cylinder

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Eggen, Svein; Kjær, Erik Michael

    2001-01-01

    The bubble inflation technique has been used for some time as a rheological characterization method for polymeric materials. Recently, this technique has been modified to the inflation of a polymeric sheet into a circular cylinder. In this work, the experimental inflation of sheets (or membranes...

  5. A constitutive analysis of the extensional flows of nearly monodisperse polyisoprene melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.

    2016-01-01

    . Ntetsikas, A. Avgeropoulos, S.-Q. Wang, Journal of Rheology 57 (1) (2013) 89–104] and shear viscosities [D. Auhl, J. Ramirez, A.E. Likhtman, P. Chambon, C. Fernyhough, Journal of Rheology 52 (3) (2008) 801–835] of narrow molecular weight distributed (NMMD) polyisoprene melts. These two formulations......’. The needed Rouse times are here defined as τR/τmax ∝ (M/Me)−1.4 with a proportional factor of 1.4, achieved based on the viscosity measurement. τmax is the maximal relaxation time, M the molecular weight and the entanglement molecular weight Me=(4/5)ρRT/GN0 [M. Doi M, S.F. Edwards, The Theory of Polymer......-isothermal effects were addressed computationally using the pseudo time principle, assuming the most critical case of adiabatic heating....

  6. Short-lived and discontinuous intraplate volcanism in the South Pacific: Hot spots or extensional volcanism?

    Science.gov (United States)

    Koppers, Anthony A. P.; Staudigel, Hubert; Pringle, Malcolm S.; Wijbrans, Jan R.

    2003-10-01

    South Pacific intraplate volcanoes have been active since the Early Cretaceous. Their HIMU-EMI-EMII mantle sources can be traced back into the West Pacific Seamount Province (WPSP) using plate tectonic reconstructions, implying that these distinctive components are enduring features within the Earth's mantle for, at least, the last 120 Myr. These correlations are eminent on the scale of the WPSP and the South Pacific Thermal and Isotopic Anomaly (SOPITA), but the evolution of single hot spots emerges notably more complicated. Hot spots in the WPSP and SOPITA mantle regions typically display intermittent volcanic activity, longevities shorter than 40 Myr, superposition of hot spot volcanism, and motion relative to other hot spots. In this review, we use 40Ar/39Ar seamount ages and Sr-Nd-Pb isotopic signatures to map out Cretaceous volcanism in the WPSP and to characterize its evolution with respect to the currently active hot spots in the SOPITA region. Our plate tectonic reconstructions indicate cessation of volcanism during the Cretaceous for the Typhoon and Japanese hot spots; whereas the currently active Samoan, Society, Pitcairn and Marquesas hot spots lack long-lived counterparts in the WPSP. These hot spots may have become active during the last 20 Myr only. The other WPSP seamount trails can be only "indirectly" reconciled with hot spots in the SOPITA region. Complex age distributions in the Magellan, Anewetak, Ralik and Ratak seamount trails would necessitate the superposition of multiple volcanic trails generated by the Macdonald, Rurutu and Rarotonga hot spots during the Cretaceous; whereas HIMU-type seamounts in the Southern Wake seamount trail would require 350-500 km of hot spot motion over the last 100 Myr following its origination along the Mangaia-Rurutu "hotline" in the Cook-Austral Islands. These observations, however, violate all assumptions of the classical Wilson-Morgan hot spot hypothesis, indicating that long-lived, deep and fixed mantle plumes cannot explain the intraplate volcanism of the South Pacific region. We argue that the observed short-lived and discontinuous intraplate volcanism has been produced by another type of hot spot-related volcanism, as opposed to the strong and continuous Hawaiian-type hot spots. Our results also indicate that other geological processes (plate tension, hotlines, faulting, wetspots, self-propagating volcanoes) may act in conjunction with hot spot volcanism in the South Pacific. In all these scenarios, intraplate volcanism has to be controlled by "broad-scale" events giving rise to multiple closely-spaced mantle plumelets, each with a distinct isotopic signature, but only briefly active and stable over geological time. It seems most likely that these plumelets originate and dissipate at very shallow mantle depths, where they may shoot off as thin plumes from the top of a "superplume" that is present in the South Pacific mantle. The absence of clear age progressions in most seamount trails and periodic flare-ups of massive intraplate volcanism in the South Pacific (such as the one in the Cretaceous and one starting 30 Myr ago) show that regional extension (caused by changes in the global plate circuit and/or the rise-and-fall of an oscillating superplume) may be driving the waxing and waning of intraplate volcanism in the South Pacific.

  7. Non-linear Shear and Uniaxial Extensional Rheology of Polyether-Ester-Sulfonate Copolymer Ionomer Melts

    DEFF Research Database (Denmark)

    Shabbir, Aamir; Huang, Qian; P. Baeza, Guilhem

    2017-01-01

    (ethylene oxide) (PEO) along the backbone in the coionomer with poly ( tetramethylene glycol) PTMO, increases the maximum Hencky strain at fracture thus adding ductility to the brittle PTMO-Na ionomer. As a result, the coionomer deforms much more compared to PTMO-Na but both fracture eventually...

  8. Landscape response to base-level fall in extensional settings: Amargosa River, Basin and Range, USA

    Science.gov (United States)

    Smith, J.; Brocklehurst, S. H.; Gawthorpe, R. L.; Finch, E.

    2012-12-01

    Studies examining transient landscapes within rift basins generally focus on settings where changes in boundary conditions are driven by active tectonics. However, the effect of drainage network re-organisation on landscape development and sediment routing has received significantly less attention. Within active rift settings it is common for drainage networks to become fragmented as uplift rates overcome the erosive potential of streams, while subsidence generates under-filled basins. On a regional-scale this results in poorly integrated drainage systems consisting of numerous internally drained basins. Integration can occur through the filling of sub-basins, lake over-spill, or drainage capture. This may dramatically affect base-level, catchment size, sediment flux and fluvial geomorphology, providing a natural experiment in fluvial response to changing boundary conditions, as well as representing a fundamental control on the ultimate preservation of sediments. We combine field and remote mapping with the available dating to investigate an example of late Pleistocene drainage integration in the southern Basin and Range, where drainage integration has resulted in a base-level fall and rejuvenation of the upstream landscape triggering further drainage rearrangement. The Amargosa River was previously part of an internally-drained basin, feeding the former Lake Tecopa. Drainage capture at 150-200 ka caused the Amargosa River to flow into Death Valley, carving the Amargosa Canyon through the Sperry Hills. The canyon itself has experienced aggradation as well as incision, with both terraces and fans representing levels above the current river. Upstream of the Amargosa Canyon, incision is reflected by minor knickpoints, and gullying along tributaries. For what is now westwards-flowing Willow Wash, the net incision of Amargosa Canyon has resulted in spectacular headward erosion, dissecting fan surfaces which previously graded northwest to Lake Tecopa. The Willow Wash area is characterised by three distinct, well-defined geomorphic domains: (i) little-modified Lake Tecopa-time fan surfaces (ii); an intermediate domain of gently incised streams and rounded hilltops; and (iii) incised canyons, featuring drainage rearrangement, both of which have implications for sediment delivery to depocentres.

  9. Mantle temperature as a control on the time scale of thermal evolution of extensional basins

    DEFF Research Database (Denmark)

    Petersen, Kenni Dinesen; Armitage, J.J.; Nielsen, S.B.

    2015-01-01

    and continues for more than 800 Myr. The longevity of basin subsidence in the continental interior can therefore be explained by variation of mantle temperature. An additional cause of the longevity of subsidence is related to the equilibrium thickness of the lithosphere which is increased by the local...... held at a constant depth....

  10. Extensional viscosity for polymer melts measured in the filament stretching rheometer

    DEFF Research Database (Denmark)

    Bach, Anders; Rasmussen, Henrik K.; Hassager, Ole

    2003-01-01

    A new filament stretching rheometer has been constructed to measure the elongational viscosity of polymer melts at high temperatures. Two polymer melts, a LDPE and a LLDPE, were investigated with this rheometer. A constant elongational rate has been obtained by an iterative application of the Orr......-Sridhar method for specification of the end-plate movement. Agreement has been found with linear viscoelastic measurements performed in shear. Hencky strains up to about 6 have been reached. Steady values of the viscosity have been sustained in some cases for about two Hencky strain units. (C) 2003 The Society...

  11. Natural frequencies of members with coupled extensional-torsional motion - A physical approach

    Science.gov (United States)

    Williams, F. W.; Howson, W. P.; Banerjee, J. R.

    1993-08-01

    When using exact distributed mass formulations to find the coupled extension-torsional natural frequencies of members, it is often useful to know a priori any necessary relationships between the natural frequencies of the member for one combination of boundary conditions and those for other combinations. In this paper, such relationships are developed for all combinations of clamped or free boundary conditions for any member with a straight axis, longitudinally invariant properties, coupled extension and torsion, and point symmetry about its midlength.

  12. Accretion of continental extensional zone and development of Rehamna metamorphic dome (Morocco)

    Science.gov (United States)

    Chopin, F.; Schulmann, K.; Corsini, M.; El Houicha, M.; Ghienne, J. F.; El Attari, M.

    2009-04-01

    The Rehamna massif is a part of the Morocco Variscan belt where the metamorphic infrastructure has been exhumed in a continental accretionary wedge. The relationships between infra- and supra-structure tectonics originate by thickening of intra-continental Devonian and Carboniferous (Mississipian) basin. Two superposed deformations probably related to plate configuration changes have been identified. The first one corresponds to the development of the Barrovian metamorphism with a climax estimated at 0.5-0.7 Gpa, 500-550°C (litt.). The thickening of thermally preheated crust is related to a SW vergent nappe stacking in the orogenic infrastructure. This event terminates with large scale folding and extrusion of high grade rocks forming a large scale E-W trending metamorphic dome surrounded by un-metamorphosed Lower Palaeozoic rocks of orogenic suprastructre indicating complete decoupling between the two crustal layers. The second E-W shortening along Western Meseta Shear Zone event is responsible for the development of important deformation gradient orthogonal to the metamorphic dome axis. It is marked by an increase of the strain intensity towards the Cambrian rigid buttress located further west. This deformation gradient is marked by mechanical coupling and gentle folding of infra- and supra-structure in the east, development of slaty cleavage in the central part of the dome and intense deformation front close to the western buttress. Here the superposed fold pattern results in accentuation of asymmetrical NE-SW trending metamorphic dome close to the buttress and to further exhumation of deepest rocks associated with subsequent elevation and folding of metamorphic isograds. 40Ar/39Ar dating reveals that the cooling associated with the first thermal event occurred at around 310 Ma (biotite) while the second thermal event yields typical Alleghanian age around 280 Ma (muscovite). This last thermal event is contemporaneous with magmatic intrusions and continental basins opening in a context of Permo-Carboniferous dextral shearing.

  13. Extensional basin evolution in the presence of small-scale convection

    DEFF Research Database (Denmark)

    Petersen, Kenni Dinesen; Nielsen, S.B.; Clausen, O.R.

    2011-01-01

    . This is formulated by assuming that the temperature at a fixed depth (the asymptotic thickness of the lithosphere) is constant. It is implicitly assumed, that this temperature is maintained by sub-lithospheric, small-scale convection, but the dynamics, controlling this process, are not considered. Here, we apply...... a two-dimensional, numerical, thermo-mechanical model of the lithosphere and upper mantle to asses the effects of small-scale convection. Given a particular mantle rheology, our model features such convection, and, over time, the horizontally averaged geotherm converges towards a self-consistent, quasi......-steady-state. Extension of the convecting equilibrium model causes the formation of rifts or continental margins which, posterior to extension, cools and subsides as predicted by the plate model. However, in contrast to the plate model, the ascended asthenosphere is not instantaneously decoupled from the convecting upper...

  14. The Moho in extensional tectonic settings: Insights from thermo-mechanical models

    NARCIS (Netherlands)

    Cloetingh, S.|info:eu-repo/dai/nl/069161836; Burov, E.; Matenco, L.|info:eu-repo/dai/nl/163604592; Beekman, F.|info:eu-repo/dai/nl/123556856; Roure, F.; Ziegler, P.A.

    2013-01-01

    The lithospheric memory is key for the interplay of lithospheric stresses and rheological structure of the extending lithosphere and for its later tectonic reactivation. Other important factors are the temporal and spatial migration of extension and the interplay of rifting and surface processes.

  15. Entangled Polymer Melts in Extensional Flow - Characterization by Combined Rheology and Small-Angle Neutron Scattering

    DEFF Research Database (Denmark)

    Mortensen, Kell; Kirkensgaard, Jacob JK; Hassager, Ole

    Liquid bridges occur in a variety of situations in nature - yet our understanding of the dynamics and stability is very limited. Examples of liquid bridges are the process used byspiders to form draglines and the process used by cats lapping milk. We have an extendedprogram aiming to provide gene...

  16. Extensional Rheology of Entangled Polystyrene Solutions Suggests Importance of Nematic Interactions

    DEFF Research Database (Denmark)

    Huang, Qian; Javier Alvarez, Nicolas; Matsumiya, Yumi

    2013-01-01

    We compare the linear and nonlinear rheological response of three entangled polystyrene solutions with the same concentration of polymer, but diluted using different solvents. The three solutions have exactly the same physical tube model parameters when normalized to the same time scale. Although...

  17. On the link between nonlinear extensional rheology and morphology of polymeric fibers

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad

    . The imposed rate of deformation along with the molecular architecture of the polymer determines the extent of molecular deformation in the flow and which, in turn, dictates the morphology of the final product. Rheology, commonly known as "the study of flow", can link molecular architecture to the final...

  18. Cienfuegos Botanical Garden and the Municipal Agricultural System, a territorial approach to local management extensionism

    Directory of Open Access Journals (Sweden)

    Tania Domínguez Soto

    2016-10-01

    Full Text Available The present work identifies the goods and services available in the Botanical Garden of Cienfuegos, from the plant genetic resources that tax the agricultural sector and that allow to establish synergies with the Agrarian System of the Municipality Cienfuegos with the purpose of producing food.

  19. Testing the Extensional Detachment Paradigm: A Borehole Observatory in the Sevier Desert Basin

    Directory of Open Access Journals (Sweden)

    Gianreto Manatschal

    2009-09-01

    Full Text Available Low-angle normal faults or detachments are widely regarded as playing an important role in crustal extension and the development of rifted continental margins (Manatschal et al., 2007. However, no consensus exists on how to resolve the mechanical paradox implied by the gentledips of these faults and by the general absence of evidence for associated seismicity (Sibson, 1985; Wernicke, 1995; Axen, 2004. As part of a new initiative to rationalize geological and geophysical evidence and our theoretical understanding of how rocks deform, a group of forty-seven scientists and drilling experts from five countries met for four days on 15–18 July 2008 to discuss the present status of the paradox and a borehole-based strategy for resolving it. The workshop was held at two venues in Utah (the Utah Department ofNatural Resources in Salt Lake City, and Solitude Mountain Resort in the adjacent Wasatch Range, with a one-day field trip to the Sevier Desert basin of west-central Utah (Figs. 1, 2 to examine the general setting of potential drill sites and the footwall geology of the Sevier Desert detachment (Canyon Range.

  20. On Dichelyne (Cucullanellus elongatus (Tornquist, 1931 Petter, 1974: South American correlated species (Nematoda, Cucullanidae and some other helminths of micropogonias furnieri (Desmarest, 1823 (Pisces, Sciaenidae Sobre Dichelyne (Cucullanellus elongatus (Tornquist, 1931 Petter, 1974: espécies sul americanas correlatas (Nematoda, Cucullanidae e alguns outros helmintos de Micropogonias furnieri (Desmarest, 1823(Pisces, Sciaenidae

    Directory of Open Access Journals (Sweden)

    J. Júlio Vicente

    1989-09-01

    Full Text Available Dichelyne (Cucullanellus elongatus (Tomquist, 1931 Petter, 1974, from Venezuela, of which D.(C. amaurincai (Freitas, Vicente & Ibáñez, 1969 Petter, 1974 is proposed as a junior synonym, is redescribed and comments on the present status of the remaining species under the group, namely D.(C. dichelyneformes (Szidat, 1950 Petter, 1974, D.(C. rodriguesi (Pinto, Fábio & Noronha, 1970 Petter, 1974 and D.(C. travassosi (Guimarães & Cristofaro, 1974, occuring in South America are made. Dollfusentis chandleri Golvan, 1969 (Acanthocephala, Illiosentidae, Poecilancistrium caryophyllum (Diesing, 1850(Cestoidea, Otobothriidae and Callitetrarhynchus gracilis (Rudolphi, 1819(Cestoidea, Dasyrhynchidae as well as larval forms of Echinocephalus sp. (Nematoda, Gnathostomatidae and Contracaecum sp. (Nematoda, Anisakidae are also reported.Dichelyne (Cucullanellus elongatus (Tornquist, 1931 Petter, 1974, da Venezuela, da qual D.(C. amaurincai (Freitas, Vicente & Ibáñez, 1969 Petter, 1974 é proposta como sinônimo junior, é descrita, e são feitos comentários sobre a atual situação das outras espécies do mesmo grupo, ocorrendo na América do Sul, a saber: D.(C. dichelyneformes (Szidat, 1950 Petter, 1974, D.(C. rodriguesi (Pinto, Fábio & Noronha, 1971 Petter, 1974 e D.(C. travassosi (Guimarães & Cristofaro, 1974. Dollfusentis chandleri Golvan, 1969 (Acantochephala, Illiosentidae, Poecilancistrium cariophyllum (Diesing, 1850 (Cestoidea, Otobothriidae e Callitetrarhynchus gracilis (Rudolphi, 1819 (Cestoidea, Dayrhynchidae bem como formas larvares de Exhinocephalus sp. (Nematoda, Gnathostomatidae e Contracaecum sp. (Nematoda, Anisakidae são também assinaladas.

  1. Documentos y otras extensiones protésicas, o como apuntalar la “identidad” Documentos y otras extensiones protésicas, o como apuntalar la “identidad”

    Directory of Open Access Journals (Sweden)

    Carmen Romero Bachiller

    2009-04-01

    Full Text Available Este artículo se acerca a la consideración de qué cuenta como “humano” desde una perspectiva posthumanista. Para ello descarta la condición fundadora o pre-dada de “lo humano” para indagar en qué requerimientos y qué articulaciones de elementos –humanos y no-humanos– habilitan “lo humano” en cuanto tal. Destaca así cómo el “cuerpo” se ha venido constituyendo en vehiculador privilegiado de “lo humano”. Analiza las relaciones entre “cuerpo-humano”, “cuerpo-sujeto”, “cuerpo-ciudadano”, destacando la compleja configuración de dichas posiciones, para indagar en las formas concretas en que un elemento “no-humano” como un DNI configura “lo humano”. Así destaca cómo un DNI se convierte en un “móvil-inmutable” (Latour y Hermant, 1999 que permite garantizar la continuidad de un “sujeto-cuerpo- ciudadano” sobre la estabilización de ciertos parámetros que se convierten en detentadores de la “verdad” del “sujeto-cuerpo” que identifican. Para ello analiza los elementos incluidos en un DNI y finalmente acude a intervenciones socio-políticas y artísticas que han usado los documentos de identidad para cuestionar, cortocircuitar, y/o desmontar las continuidades invisibilizadas y dadas por supuestas que articulan la relación entre un “cuerpo-sujeto-ciudadano” concreto y su documentación. Esa relación por la cual el DNI se convierte en el “sujeto” y el “sujeto” es su DNI.This article faces the consideration of what does count as “human” from a posthumanist perspective. By discarding the founder or pre-given condition of “human”, it seeks which requirements and articulations of elements –both human and non-human– habilitate the properly “human” as such. Therefore, it highlights how the “body” has become a privileged site for “the human”. Further, it analyses the relations between “human-body”, “subject-body”, “citizen-body”, stressing the complex configuration of those positions, to inquire on the singular forms in which a “non-human” element such as an ID configures the properly “human”. An ID becomes then, an “immutable mobile” (Latour y Hermant, 1999 which allows for a guarantée of the continuity of a “citizen-body-subject” on the stabilization of certain parameters that become the “truth” keepers of the “body-subject” they identify. The article analyses the items included in an ID and, finally, follows some socio-political and artistic interventions that have employed identity documents to question, short-circuit, and/or dismantle the invisibilised and taken for granted continuities that articulate the relationship between a particular “citizen-body-subject” and its documents. That relation by which an ID becomes the “subject” and the “subject” is its ID.

  2. Migration of geothermal fluids in extensional terrains: the ore deposits of the Boccheggiano-Montieri area (southern Tuscany, Italy)

    Science.gov (United States)

    Liotta, Domenico; Ruggieri, Giovanni; Brogi, Andrea; Fulignati, Paolo; Dini, Andrea; Nardini, Isabella

    2010-04-01

    An integrated study based on fluid inclusion, δ18O composition and structural analyses was carried out on a Pliocene fossil hydrothermal system, located to the South of the present active Larderello geothermal field, in the Boccheggiano-Montieri area. The study area is typified by mineralized cataclastic levels related to Late Oligocene-Early Miocene thrust surfaces, and to the following two generations of normal faults of Miocene and Pliocene ages, respectively. Within the damage zone of the Pliocene Boccheggiano fault, the mineralization is mainly made up of quartz and pyrite. Quartz + Pb-Zn sulfides, or quartz + Pb-Zn sulfides + fluorite + carbonates assemblages occur instead in the older cataclastic levels. Two generations of liquid-rich fluid inclusions were recognized in quartz and fluorite: the first one, with homogenization temperatures ranging between 172 and 331°C and salinity between 0.0 and 8.8 wt.% NaClequiv., records the early stage of hydrothermal activity. The second generation of fluid inclusions documents a later stage, with homogenization temperature from 124 to 288°C and salinity from 0.2 to 1.9 wt.% NaClequiv.. Fluid inclusions analyses also indicate that mixing of fluid with distinct salinities and/or temperatures was a widespread process during the early stage, and that fluid temperatures decreased moving from the Boccheggiano fault toward the more distal and older cataclastic levels. The δ18O values of water in equilibrium with hydrothermal quartz, which range from -5.7 to -0.1‰, are related to the circulation of meteoric water mixed with saline water that leached the evaporite level and enriched in δ18O through water-rock interaction, and/or with magmatically derived fluids. Results indicate that the damage zone of the Pliocene Boccheggiano fault represented the main channel for the flow of meteoric water, which was heated at depth, then mixed with high salinity fluids, and finally ascend to infiltrate along the older cataclastic levels. Our results, based on fluid inclusions, oxygen isotopic compositions and structural analyses indicate that a single fluid flow path run through the damage zone of the Boccheggiano fault and the older cataclasites, which were thus hydraulically connected.

  3. Characterisation of extensional faults in carbonate rocks (Suez Rift, Egypt); with particular focus on the role of shale smear

    OpenAIRE

    Elvik, Lillian

    2012-01-01

    The distribution, composition and flow-properties of fault core and shale smear along faults in carbonate reservoirs is less well understood compared to faults in siliciclastic rocks. This study uses field data to characterize and quantify fault zone properties that are critical for understanding structural heterogeneity in carbonate reservoirs. The study focus on; (1) variability and co-dependence of displacement, shale smear, fault- thickness, -composition and -geometry; (2) the effect o...

  4. Effect of extensional cyclic strain on the mechanical and physico-mechanical properties of PVC-NBR/graphite composites

    Directory of Open Access Journals (Sweden)

    2008-12-01

    Full Text Available The variation of electrical resistivity as will as the mechanical properties of PVC (polyvinylchloride-NBR (acrylonitrile butadiene rubber based conductive composites filled with different concentrations of graphite were studied. These samples were studied as function of the constant deformation fatigue test. When the specimen was subjected to a large number of rapidly repeating strain cycles, and different strain amplitudes, the conductivity, σ(T, shows an initial rapid fall followed by dynamic equilibrium. Increasing the number of cycles and strain amplitudes, the conductivity remains almost constant over the temperature range 30–140°C. The equilibrium state between destruction and reconstruction of graphite particles has been detected for all strains of certain values of strain cycles (1000, 2000, 3000, and 4000 cycles for 30% strain amplitude. A preliminary study was done to optimize the possibility to use Conductive Polymer Composites (CPC as a strain sensor and to evaluate its performance by an intrinsic physico-mechanical modification measurement. The electromechanical characterization was performed to demonstrate the adaptability and the correct functioning of the sensor as a strain gauge on the fabric. The coefficient of strain sensitivity (K was measured for 50 phr graphite/PVCNBR vulcanized at 3000 number of strain cycles and 30% strain amplitude. There was a broad maximum of K, with a peak value of 82, which was much higher, compared to conventional wire resistors. A slight hysteresis was observed at unloading due to plasticity of the matrix. A good correlation exists between mechanical and electrical response to the strain sensitivity. Mechanical reinforcement was in accordance with the Quemada equation [1] and Guth model [2] attested to good particle-matrix adhesion. It was found that the viscous component of deformation gradually disappeared and the hardening occurred with increasing strain cycles. The modulus, fracture strength, and elongation at break increased with increasing filler volume fraction up to 40 phr of graphite particles.

  5. Supra-subduction zone extensional magmatism in Vermont and adjacent Quebec: Implications for early Paleozoic Appalachian tectonics

    Science.gov (United States)

    Kim, J.; Coish, R.; Evans, M.; Dick, G.

    2003-01-01

    Metadiabasic intrusions of the Mount Norris Intrusive Suite occur in fault-bounded lithotectonic packages containing Stowe, Moretown, and Cram Hill Formation lithologies in the northern Vermont Rowe-Hawley belt, a proposed Ordovician arc-trench gap above an east-dipping subduction zone. Rocks of the Mount Norris Intrusive Suite are characteristically massive and weakly foliated, have chilled margins, contain xenoliths, and have sharp contacts that both crosscut and are parallel to early structural fabrics in the host metasedimentary rocks. Although the mineral assemblage of the Mount Norris Intrusive Suite is albite + actinolite + epidote + chlorite + calcite + quartz, intergrowths of albite + actinolite are probably pseudomorphs after plagioclase + clinopyroxene. The metadiabases are subalkaline, tholeiitic, hypabyssal basalts with preserved ophitic texture. A backarc-basin tectonic setting for the intrusive suite is suggested by its LREE (light rare earth element) enrichment, negative Nb-Ta anomalies, and Ta/Yb vs. Th/Yb trends. Although no direct isotopic age data are available, the intrusions are broadly Ordovician because their contacts are clearly folded by the earliest Acadian (Silurian-Devonian) folds. Field evidence and geochemical data suggest compelling along-strike correlations with the Coburn Hill Volcanics of northern Vermont and the Bolton Igneous Group of southern Quebec. Isotopic and stratigraphic age constraints for the Bolton Igneous Group bracket these backarc magmas to the 477-458 Ma interval. A tectonic model that begins with east-dipping subduction and progresses to outboard west-dipping subduction after a syncollisional polarity reversal best explains the intrusion of deformed metamorphosed metasedimentary rocks by backarc magmas.

  6. Strike-slip and extensional tectonics of the Tan-Lu fault zone (eastern China) from the Cretaceous to Cenozoic

    Science.gov (United States)

    Zhang, Y. Q.; Shi, W.; Dong, S. W.

    2003-04-01

    The Tan-Lu fault zone which extends NNE-SSW more than 3000 km forms conspicuous geological feature along the northeastern margin of the Asia continent. Since its recognition by air-magnetic anomaly in 1957, this fault zone has become the subject of live debate. Most studies were mainly focused on the amount and age of the sinistral offsets along its middle and southern segments. It has been generally thought that the Tan-Lu fault zone was initiated as a transform fault during the Triassic collision between the South and North China Blocks and that it was strongly activated during the Cretaceous and Cenozoic time period. Some authors proposed that the Tan-Lu fault is part of a wide wrench fault system along the north-eastern Asia continent and that sinistral movement along this fault system accommodated oblique convergence between the Pacific oceanic plate and the Asia continent. Some others considered that the Tan-Lu fault belongs to the rifting system of eastern China. Based on field analysis of slip vector data from different rock units of the Cretaceous basins along the middle Tan-Lu fault zone (Shandong Province, eastern China), we document polyphase tectonic stress fields and address the changes in the sense of motion of the Tan-Lu fault zone during the Cretaceous and Cenozoic. The Cretaceous deformation history of the Tan-Lu fault zone can be divided into four main stages. The first stage during the lowermost Cretaceous was dominated by N-S extension, which is responsible for the formation of the Jiaolai basin. We interpret this extension to be related to dextral strike-slip pull-apart opening guided by the Tan-Lu fault zone. The second stage during the middle Early Cretaceous was overwhelmingly rift-dominated, and characterized by widespread intermediate volcanism, normal faulting and basin subsidence. It was at this stage that the Tan-Lu-parallel Yi-Shu Rift was initiated by E-W to WNW-ESE extension. The tectonic regime changed during the late Early Cretaceous to NW-SE oriented transpression, causing inversion of the Lower Cretaceous rift basin and sinistral motion along the Tan-Lu fault. During the Late Cretaceous, dextral activation of the Tan-Lu fault zone resulted in pull-apart opening of the Zhucheng basin, which was subsequently deformed by NE-SW compression. The Cenozoic deformation history of the Tan-Lu fault zone can be separated into three periods: Early Tertiary normal faulting resulting from NW-SE extension; Miocene normal faulting imposed by NE-SW to NNE-SSW extension; and Quaternary dextral strike-slip faulting caused by ENE-WSW compression. The Early Tertiary extension was responsible for rift basin formation in north China and originated from back-roll mantle convection induced by westward subduction of the Pacific plate beneath the eastern margin of the Asia continent. The Miocene extension may have been genetically associated with process of the Japan Sea opening. The Quaternary faulting mainly occurred along the middle portion of the active Tan-Lu fault zone and resulted from far-field effect of the late-stage India and Eurasia convergence.

  7. Constant interchain pressure effect in extensional flows of oligomer diluted polystyrene and poly(methyl methacrylate) melts

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Huang, Qian

    2017-01-01

    The constant ‘interchain pressure’ idea has been addressed, to evaluate if it is an adequate quantitative assumption to describe the fluid mechanics of oligomer diluted entangled NMMD polymer systems. The molecular stress function constitutive framework has been used with the constant interchain ......)s and almost all published oligomer diluted NMMD polystyrenes. The only deviation is on the most diluted and largest molecular weight case of an 18% 1880 kg/mol polystyrene in oligomer diluent. In this case, the maximal extensibility is not needed....

  8. Ultrasonics transduction in metallic and composite structures for structural health monitoring using extensional and shear horizontal piezoelectric wafer active sensors

    Science.gov (United States)

    Abdelrahman, Ayman Kamal

    Structural health monitoring (SHM) is crucial for monitoring structures performance, detecting the initiation of flaws and damages, and predicting structural life span. The dissertation emphasizes on developing analytical and numerical models for ultrasonics transduction between piezoelectric wafer active sensors (PWAS), and metallic and composite structures. The first objective of this research is studying the power and energy transduction between PWAS and structure for the aim of optimizing guided waves mode tuning and PWAS electromechanical (E/M) impedance for power-efficient SHM systems. Analytical models for power and energy were developed based on exact Lamb wave solution with application on multimodal Lamb wave situations that exist at high excitation frequencies and/or relatively thick structures. Experimental validation was conducted using Scanning Laser Doppler Vibrometer. The second objective of this work focuses on shear horizontal (SH) PWAS which are poled in thickness-shear direction (d35 mode). Analytical and finite element predictive models of the E/M impedance of free and bonded SH-PWAS were developed. Next, the wave propagation method has been considered for isotropic materials. Finally, the power and energy of SH waves were analytically modeled and a MATLAB graphical user interface (GUI) was developed for determining phase and group velocities, mode shapes, and energy of SH waves. The third objective focuses on guided wave propagation in composites. The transfer matrix method (TMM) has been used to calculate dispersion curves of guided waves in composites. TMM suffers numerical instability at high frequency-thickness values, especially in multilayered composites. A method of using stiffness matrix method was investigated to overcome instability. A procedure of using combined stiffness transfer matrix method (STMM) was presented and coded in MATLAB. This was followed by a comparative study between commonly used methods for the calculation of ultrasonic guided waves in composites, e.g. global matrix method (GMM), semi--analytical finite element (SAFE). The last part of this dissertation addresses three SHM applications: (1) using the SH-PWAS for case studies on composites, (2) testing of SHM industrial system for damage detection in an aluminum aerospace-like structure panel, and (3) measuring dispersion wave propagation speeds in a variable stiffness CFRP plate.

  9. Outcrop-scale evidence for the Norian-Rhaetian extensional tectonics in the Slovenian Basin (Southern Alps

    Directory of Open Access Journals (Sweden)

    Primož Oprčkal

    2012-06-01

    Full Text Available No direct evidence for the Norian-Rhaetian tectonic activity has been gathered from the Slovenian territoryuntil now. In the quarry in the vicinity of Škofja Loka, several palaeofaults transect the outcropping Bača Dolomite.The Norian-Rhaetian age of the Bača Dolomite is confirmed with the finding of the conodont species Norigondolellasteinbergensis (Mosher, 1968. The formation of the faults is related to the openning of the future JurassicPiemont-Ligurian Ocean to the west of the studied area, or with the diminishing influence of the Neotethys (Meliana Ocean to the east.

  10. Transient extensional viscosity of polymers in the filament strecthing rheometer. A. Bach, H.K. Rasmussen, O. Hassager

    DEFF Research Database (Denmark)

    Rasmussen, Henrik Koblitz; Bach, Anders; Hassager, Ole

    2002-01-01

    We investigate the transient uni-axial eextensional viscosity of polymer melts by means of a filament strecthing rheometer.......We investigate the transient uni-axial eextensional viscosity of polymer melts by means of a filament strecthing rheometer....

  11. Coseismic Pit Crater, Normal Fault, and Extensional Fissure Formation in Unconsolidated Sediment and Basalt in Northern Iceland

    Science.gov (United States)

    Ferrill, D. A.; Wyrick, D. Y.; Smart, K. J.

    2008-12-01

    Two rifting-related seismic events in 1975 and 1978 along the Mid-Atlantic Ridge near the northern coast of Iceland produced an array of surface deformation features in Holocene basalt flows and overlying unconsolidated sediments. New field mapping and aerial photograph interpretation is coupled with analysis of maps of seismic activity and level-line survey results to constrain the timing, style, and magnitude of this deformation. Fault scarps and fissures in basalts can be traced laterally down a gentle northward dip projecting into unconsolidated braided stream deposits, providing an impressive view of the deformation style in the two contrasting mechanical layers. We report on detailed field mapping of two of these laterally traceable structures conducted in the summer of 2008 and analysis of a suite of aerial photographs from 1958 to 1998. Map-scale structures in the basalts with little or no sedimentary cover include (i) fault scarps, (ii) fissures, and (iii) locally-developed gentle dip away from the related normal fault. Dilation of faults and extension fractures in the basalt has led to rock toppling and rock fall causing widening of fissures. Wedging of toppled rock blocks at the tops of fissures has locally produced keystone arches and bridges across the tops of open fissures. Different stages in the progression of fissure formation and collapse, including (i) fissure, (ii) widened fissure with cavern, (iii) localized collapse pit, and (iv) elongate collapsed fissure, can be observed over along-strike distances of 10's of meters. Where unconsolidated sand and gravel deposits >3 m thick cover the basalts (200 m to the north along strike) structural geomorphologic features are dominated by (i) grabens, (ii) pit craters, and (iii) elongate troughs. Graben-bounding normal faults cutting the sedimentary cover in many cases have displacements >1 m. Pit craters have cone to bowl shapes, commonly occur within grabens, and have depths up to 2.8 m. The mapped surface structures in the braided stream deposits formed during the 1975 and 1978 rifting events and were likely triggered by reactivation of faults and fissures in the underlying basalt. Fissures, caverns, pits, and troughs in the basalt and braided stream deposits are partially water filled, extending below the local water table. We interpret that pit craters formed in basalt by collapse into caverns formed by fissure-widening rock fall, and in sediments by draining of unconsolidated material downward into fault or fissure-related voids in the underlying basalt. In sediments, troughs appear to be produced by a combination of graben formation and pit crater amalgamation. A sequence of development from pit crater chain (or pit chain within graben) to trough to fissure occurs with increasing dilational fault displacement or fissure width, and as a function of sedimentary cover thickness. This field based study demonstrates that pit craters are readily explained by draining or falling of poorly consolidated material downward into subterranean cavities produced by coseismic fault and extension-fracture dilation in underlying cohesive material (basalt). Directly analogous geomorphologic patterns on Mars, clearly visible in high resolution surface imagery, suggest that similar mechanisms of deformation and surface collapse may be at work on Mars.

  12. Formation of the Wiesloch Mississippi Valley-type Zn-Pb-Ag deposit in the extensional setting of the Upper Rhinegraben, SW Germany

    Science.gov (United States)

    Pfaff, Katharina; Hildebrandt, Ludwig H.; Leach, David L.; Jacob, Dorrit E.; Markl, Gregor

    2010-10-01

    The Mississippi Valley-type (MVT) Zn-Pb-Ag deposit in the Wiesloch area, Southwest Germany, is controlled by graben-related faults of the Upper Rhinegraben. Mineralization occurs as vein fillings and irregular replacement ore bodies consisting of sphalerite, banded sphalerite, galena, pyrite, sulfosalts (jordanite and geocronite), barite, and calcite in the Middle Triassic carbonate host rock. Combining paragenetic information, fluid inclusion investigations, stable isotope and mineral chemistry with thermodynamic modeling, we have derived a model for the formation of the Wiesloch deposit. This model involves fluid mixing between ascending hot brines (originating in the crystalline basement) with sedimentary formation waters. The ascending brines originally had a near-neutral pH (around 6) and intermediate oxidation state, reflecting equilibrium with granites and gneisses in the basement. During fluid ascent and cooling, the pH of the brine shifted towards more acidic (around 4) and the oxidation state increased to conditions above the hematite-magnetite buffer. These chemical characteristics contrast strongly with those of the pore and fracture fluid residing in the limestone aquifer, which had a pH between 8 and 9 in equilibrium with calcite and was rather reduced due to the presence of organic matter in the limestone. Mixing between these two fluids resulted in a strong decrease in the solubility of silver-bearing sphalerite and galena, and calcite. Besides Wiesloch, several Pb-Zn deposits are known along the Upper Rhinegraben, including hydrothermal vein-type deposits like Badenweiler and the Michael mine near Lahr. They all share the same fluid origin and formation process and only differ in details of their host rock and fluid cooling paths. The mechanism of fluid mixing also seems to be responsible for the formation of other MVT deposits in Europe (e.g., Réocin, Northern Spain; Trèves, Southern France; and Cracow-Silesia, Poland), which show notable similarities in terms of their age, mineralogy. and mineral chemistry to the MVT deposit near Wiesloch.

  13. Building the Pamir-Tibetan Plateau—Crustal stacking, extensional collapse, and lateral extrusion in the Central Pamir: 1. Geometry and kinematics

    Science.gov (United States)

    Rutte, Daniel; Ratschbacher, Lothar; Schneider, Susanne; Stübner, Konstanze; Stearns, Michael A.; Gulzar, Muhammad A.; Hacker, Bradley R.

    2017-03-01

    Asian deep crust exposed in the Pamir permits determination of the amount, sequence, and interaction of shortening, extension, and lateral extrusion over 30 km of crustal section during the India-Asia collision. In the Central Pamir, gneiss domes and their hanging walls record Paleogene tripling of the 7-10 km thick Phanerozoic upper crustal strata; total crustal thickness may have amounted to 90 km. Two thrust sheets, comprising Cambro-Ordovician, respectively, Carboniferous to Paleogene strata, straddle the domes. Amphibolite-facies metamorphic rocks within the domes—equivalent to lower grade rocks outside the domes—form fold nappes with dome-scale wavelengths. E-W stretching occurred contemporaneously with top-to- N imbrication and folding. At 22-12 Ma, bivergent (top-to-N and top-to-S), normal-sense shear zones exhumed the crystalline rocks; most of the extension occurred along the northern dome margins. Shortening resumed at 12 Ma with opposite-sense thrusting and folding focused along the dome margins. Throughout the building of the Central and South Pamir, dominant N-S shortening interacted with E-W extension along mostly dextral shear/fault zones. In the Neogene, shear is concentrated along a dextral wrench corridor south of the domes. We interpret the Paleogene shortening to record thickening and northward growth of the Pamir-Tibetan Plateau and short-lived Miocene crustal extension as gravitational adjustment, i.e., collapse, of the thickened Asian crust to Indian slab breakoff. Synconvergent Paleogene lateral extrusion thickened the Afghan Hindu Kush crust west of the India-Asia collision, and the Miocene-Recent dextral shear and E-W extension have accommodated collapse of the Pamir Plateau into the Tajik depression.

  14. Building the Pamir-Tibetan Plateau—Crustal stacking, extensional collapse, and lateral extrusion in the Central Pamir: 2. Timing and rates

    Science.gov (United States)

    Rutte, Daniel; Ratschbacher, Lothar; Khan, Jahanzeb; Stübner, Konstanze; Hacker, Bradley R.; Stearns, Michael A.; Enkelmann, Eva; Jonckheere, Raymond; Pfänder, Jörg A.; Sperner, Blanka; Tichomirowa, Marion

    2017-03-01

    Geothermochronologic data outline the temperature-deformation-time evolution of the Muskol and Shatput gneiss domes and their hanging walls in the Central Pamir. Prograde metamorphism started before 35 Ma and peaked at 23-20 Ma, reflecting top-to- N thrust-sheet and fold-nappe emplacement that tripled the thickness of the upper 7-10 km of the Asian crust. Multimethod thermochronology traces cooling through 700-100°C between 22 and 12 Ma due to exhumation along dome-bounding normal-sense shear zones. Synkinematic minerals date normal sense shear-zone deformation at 22-17 Ma. Age-versus-elevation relationships and paleoisotherm spacing imply exhumation at ≥3 km/Myr. South of the domes, Mesozoic granitoids record slow cooling and/or constant temperature throughout the Paleogene and enhanced cooling (7-31°C/Myr) starting between 23 and 12 Ma and continuing today. Integrating the Central Pamir data with those of the East (Chinese) Pamir Kongur Shan and Muztaghata domes, and with the South Pamir Shakhdara dome, implies (i) regionally distributed, Paleogene crustal thickening; (ii) Pamir-wide gravitational collapse of thickened crust starting at 23-21 Ma during ongoing India-Asia convergence; and (iii) termination of doming and resumption of shortening following northward propagating underthrusting of the Indian cratonic lithosphere at ≥12 Ma. Westward lateral extrusion of Pamir Plateau crust into the Hindu Kush and the Tajik depression accompanied all stages. Deep-seated processes, e.g., slab breakoff, crustal foundering, and underthrusting of buoyant lithosphere, governed transitional phases in the Pamir, and likely the Tibet crust.

  15. Alcances y límites del análisis de redes sociales en la actualidad: una reflexión sobre tres deseables extensiones

    Directory of Open Access Journals (Sweden)

    Jorge E. Miceli

    2011-01-01

    Full Text Available El análisis de redes sociales (ARS ha experimentado un creci - miento incesante en los últimos años, generando expectativas de consolidación que exceden nuestra capacidad reĚexiva. En este artículo he abordado dos tipos de limitaciones devenidas de distintas etapas de cualquier proceso investigativo. Por un lado hago referencia a perspectivas epistemológicas que implican ciertas limitaciones al momento de pensar la investigación sobre redes sociales. Por el otro, tengo en cuenta algunas imposibilida - des surgidas del desarrollo práctico del soĞware y de los disposi - tivos y heurísticas de cálculo usados. En particular, destaco aquí las cuestiones relacionadas con la ausencia de una perspectiva temporal en ARS, con el uso de la intuición naturalista en la re- presentación de las redes y con la suposición de la aleatoriedad relacional como la norma típica en las redes que de forma empí- rica existen.

  16. A-type granitoid in Hasansalaran complex, northwestern Iran: Evidence for extensional tectonic regime in northern Gondwana in the Late Paleozoic

    Science.gov (United States)

    Azizi, Hossein; Kazemi, Tahmineh; Asahara, Yoshihiro

    2017-07-01

    The Hasansalaran plutonic complex is one of the main intrusive bodies with a wide range of granite, monzonite, diorite and syenite that crop out in northwest Iran. This body includes Paleozoic granitoids that are surrounded and cut by Cretaceous granitoids. Zircon U-Pb age dating shows that the crystallization of this body occurred at 360 Ma ago in the Early Carboniferous. Whole rock compositions of the investigated intrusive body, show high contents of Ga (11.1-76.3 ppm), Zr (73.5-1280 ppm), Zn (43.7-358 ppm), Y(17.9-177 ppm), enrichment of rare earth elements (REEs) together with high Ga/Al ratios and a strong Eu negative anomaly, fairly consistent with typical A-type signature. The low εNd(t = 360 Ma) value (oceanic released fluids in the subduction zone. These high Nb content rocks (37.2-342 ppm without one sample) are classified as A1-type granitoids. Based on the distribution of A1- and A2-type granitoids in the Late Paleozoic in northwest Iran, the existence of some gabbroic rocks with tholeiitic to alkali composition and a long gap for magmatic activities in the area from 550 to 360 Ma (approximately 180 my.a.) between the Zagros and Tabriz faults, we suggest a new thematic model for evolution of northwest Iran in the Late Paleozoic. Based on our model, the upwelling of a mantle plume, probably due to the proto-Tethys oceanic rollback activity beneath northern Gondwana, had a crucial role in the uplifting of the continental crust and resulted in the crystallization of A-type granitoids with some gabbroic rocks in northwest Iran.

  17. Deep permeable fault-controlled helium transport and limited mantle flux in two extensional geothermal systems in the Great Basin, United States

    Science.gov (United States)

    Banerjee, Amlan; Person, Mark; Hofstra, Albert; Sweetkind, Donald S.; Cohen, Denis; Sabin, Andrew; Unruh, Jeff; Zyvoloski, George; Gable, Carl W.; Crossey, Laura; Karlstrom, Karl

    2011-01-01

    This study assesses the relative importance of deeply circulating meteoric water and direct mantle fluid inputs on near-surface 3He/4He anomalies reported at the Coso and Beowawe geothermal fields of the western United States. The depth of meteoric fluid circulation is a critical factor that controls the temperature, extent of fluid-rock isotope exchange, and mixing with deeply sourced fluids containing mantle volatiles. The influence of mantle fluid flux on the reported helium anomalies appears to be negligible in both systems. This study illustrates the importance of deeply penetrating permeable fault zones (10-12 to 10-15 m2) in focusing groundwater and mantle volatiles with high 3He/4He ratios to shallow crustal levels. These continental geothermal systems are driven by free convection.

  18. Biodiscos: una alternativa de tratamiento biológico para aguas residuales cuando no se dispone de grandes extensiones de terreno

    OpenAIRE

    Deloya Martínez, Alma

    2015-01-01

    Uno de los sistemas más recientes para el tratamiento de aguas residuales es el Contador Biológico Rotatorio (CBR) comúnmente conocido como Biodisco. Este sistema de tratamiento biológico secundario es usado para la remoción de la Demanda Bioquímica de Oxígeno (DBO) y para el pulido de efluentes nitrificados1. El biodisco se usó por primera vez en Alemania en 1900 y en 1929 en los Estados Unidos. En ambos casos fueron construidos de madera. En 1950 se realizaron pruebas con discos de plástico...

  19. Key role of Upper Mantle rocks in Alpine type orogens: some speculations derived from extensional settings for subduction zone processes and mountain roots

    Science.gov (United States)

    Müntener, Othmar

    2016-04-01

    Orogenic architecture and mountain roots are intrinsically related. Understanding mountain roots largely depends on geophysical methods and exhumed high pressure and high temperature rocks that might record snapshots of the temporal evolution at elevated pressure, temperatures and/or fluid pulses. If such high pressure rocks represent ophiolitic material they are commonly interpreted as exhumed remnants of some sort of 'mid-ocean ridge' processes. Mantle peridotites and their serpentinized counterparts thus play a key role in understanding orogenic architecture as they are often considered to track suture zones or ancient plate boundaries. The recognition that some mantle peridotites and their serpentinized counterparts are derived from ocean-continent transition zones (OCT's) or non-steady state (ultra-)slow plate separation systems question a series of 'common beliefs' that have been applied to understand Alpine-type collisional orogens in the framework of the ophiolite concept. Among these are: (i) the commonly held assumption of a simple genetic link between mantle melting and mafic (MORB-type) magmatism, (ii) the commonly held assumption that mélange zones represent deep subduction zone processes at the plate interface, (iii) that pre-collisional continental crust and oceanic crust can easily be reconstructed to their original thickness and used for reconstructions of the size of small subducted oceanic basins as geophysical data from rifted margins increasingly indicate that continental crust is thinned to much less than the average 30-35 kilometers over a large area that might be called the 'zone of hyperextension', and (iv) the lack of a continuous sheet of mafic oceanic crust and the extremely short time interval of formation results in a lack of 'eclogitization potential' during convergence and hence a lack of potential for subsequent slab pull and, perhaps, a lack of potential for 'slab-breakoff'. Here we provide a synopsis of mantle rocks from the European realm to show that inherited mantle signatures from previous orogenies play a key role for the interpretation of ophiolites, and that peridotites from present-day passive margins show striking similarities to the metamorphic equivalents in Alpine type orogens. If the dimensions of mantle exhumation and the formation of proto-oceanic crust (refertilized domains) from present-day margins such as the Iberia-Newfoundland or the Australian - Antartic margins are applicable to the Alps, then there is little room for steady-state oceanic crust in the Ligurian Tethys. Possible consequences for mountain roots will be discussed.

  20. From nappe stacking to extensional detachments at the contact between the Carpathians and Dinarides – The Jastrebac Mountains of Central Serbia

    NARCIS (Netherlands)

    Erak, Dalibor; Matenco, Liviu; Toljić, Marinko; Stojadinović, Uroš; Andriessen, Paul A.M.; Willingshofer, Ernst; Ducea, Mihai N.

    2017-01-01

    Reactivation of inherited nappe contacts is a common process in orogenic areas affected by back-arc extension. The amount of back-arc extension is often variable along the orogenic strike, owing to the evolution of arcuated mountain chains during stages of rapid slab retreat. This evolution creates

  1. Formation of the Wiesloch Mississippi Valley-type Zn-Pb-Ag deposit in the extensional setting of the Upper Rhinegraben, SW Germany

    Science.gov (United States)

    Pfaff, Katharina; Hildebrandt, Ludwig H.; Leach, David L.; Jacob, Dorrit E.; Markl, Gregor

    2010-01-01

    The Mississippi Valley-type (MVT) Zn-Pb-Ag deposit in the Wiesloch area, Southwest Germany, is controlled by graben-related faults of the Upper Rhinegraben. Mineralization occurs as vein fillings and irregular replacement ore bodies consisting of sphalerite, banded sphalerite, galena, pyrite, sulfosalts (jordanite and geocronite), barite, and calcite in the Middle Triassic carbonate host rock. Combining paragenetic information, fluid inclusion investigations, stable isotope and mineral chemistry with thermodynamic modeling, we have derived a model for the formation of the Wiesloch deposit. This model involves fluid mixing between ascending hot brines (originating in the crystalline basement) with sedimentary formation waters. The ascending brines originally had a near-neutral pH (around 6) and intermediate oxidation state, reflecting equilibrium with granites and gneisses in the basement. During fluid ascent and cooling, the pH of the brine shifted towards more acidic (around 4) and the oxidation state increased to conditions above the hematite-magnetite buffer. These chemical characteristics contrast strongly with those of the pore and fracture fluid residing in the limestone aquifer, which had a pH between 8 and 9 in equilibrium with calcite and was rather reduced due to the presence of organic matter in the limestone. Mixing between these two fluids resulted in a strong decrease in the solubility of silver-bearing sphalerite and galena, and calcite. Besides Wiesloch, several Pb-Zn deposits are known along the Upper Rhinegraben, including hydrothermal vein-type deposits like Badenweiler and the Michael mine near Lahr. They all share the same fluid origin and formation process and only differ in details of their host rock and fluid cooling paths. The mechanism of fluid mixing also seems to be responsible for the formation of other MVT deposits in Europe (e.g., Reocin, Northern Spain; Treves, Southern France; and Cracow-Silesia, Poland), which show notable similarities in terms of their age, mineralogy, and mineral chemistry to the MVT deposit near Wiesloch.

  2. Implementación de extensiones simbólicas al lenguaje SQL en servidores de bases de datos objeto-relacionales

    Directory of Open Access Journals (Sweden)

    Johnny Villalobos-Murillo

    2015-07-01

    Full Text Available Este artículo propone extender el lenguaje SQL al crear nuevos tipos de datos con sus respectivos operadores, que permitan crear y manipular objetos simbólicos directamente sobre las bases de datos. La funcionalidad de la extensión propuesta se valida realizando transformaciones de datos relacionales clásicos a objetos simbólicos en bases de datos de gran volumen. Para los usuarios no familiarizados con el lenguaje SQL, se construye una interfaz de usuario final, que facilita y guía el proceso de transformación simbólica.

  3. Late Cretaceous extensional denudation along a marble detachment fault zone in the Kırşehir massif near Kaman, central Turkey

    NARCIS (Netherlands)

    Lefebvre, C.J.C.; Barnhoorn, A.; Hinsbergen, D.J.J. van; Kaymakçi, N.; Vissers, R.L.M.

    2011-01-01

    In the Central Anatolian Crystalline Complex (CACC), 100 km scale metamorphic domains were exhumed in a context of north-south plate convergence during late Cretaceous to Cenozoic times. The timing, kinematics and mechanisms of exhumation have been the focus of previous studies in the southern Ni

  4. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Final report, March 1996--September 1998

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.; Groshong, R.H.; Jin, G.

    1998-12-01

    This project was designed to analyze the structure of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas to suggest ways in which oil recovery can be improved. The Eutaw Formation comprises 7 major flow units and is dominated by low-resistivity, low-contrast play that is difficult to characterize quantitatively. Selma chalk produces strictly from fault-related fractures that were mineralized as warm fluid migrated from deep sources. Resistivity, dipmeter, and fracture identification logs corroborate that deformation is concentrated in the hanging-wall drag zones. New area balancing techniques were developed to characterize growth strata and confirm that strain is concentrated in hanging-wall drag zones. Curvature analysis indicates that the faults contain numerous fault bends that influence fracture distribution. Eutaw oil is produced strictly from footwall uplifts, whereas Selma oil is produced from fault-related fractures. Clay smear and mineralization may be significant trapping mechanisms in the Eutaw Formation. The critical seal for Selma reservoirs, by contrast, is where Tertiary clay in the hanging wall is juxtaposed with poorly fractured Selma chalk in the footwall. Gilbertown Field can be revitalized by infill drilling and recompletion of existing wells. Directional drilling may be a viable technique for recovering untapped oil from Selma chalk. Revitalization is now underway, and the first new production wells since 1985 are being drilled in the western part of the field.

  5. Seismic valve as the main mechanism for sedimentary fluid entrapment within extensional basin: example of the Lodève Permian Basin (Hérault, South of France).

    Science.gov (United States)

    Laurent, D.; Lopez, M.; Chauvet, A.; Imbert, P.; Sauvage, A. C.; Martine, B.; Thomas, M.

    2014-12-01

    During syn-sedimentary burial in basin, interstitial fluids initially trapped within the sedimentary pile are easily moving under overpressure gradient. Indeed, they have a significant role on deformation during basin evolution, particularly on fault reactivation. The Lodève Permian Basin (Hérault, France) is an exhumed half graben with exceptional outcrop conditions providing access to barite-sulfides mineralized systems and hydrocarbon trapped into rollover faults of the basin. Architectural studies shows a cyclic infilling of fault zone and associated S0-parallel veins according to three main fluid events during dextral/normal faulting. Contrasting fluid entrapment conditions are deduced from textural analysis, fluid inclusion microthermometry and sulfide isotope geothermometer: (i) the first stage is characterized by an implosion breccia cemented by silicifications and barite during abrupt pressure drop within fault zone; (ii) the second stage consists in succession of barite ribbons precipitated under overpressure fluctuations, derived from fault-valve action, with reactivation planes formed by sulphide-rich micro-shearing structures showing normal movement; and (iii) the third stage is associated to the formation of dextral strike-slip pull-apart infilling by large barite crystals and contemporary hydrocarbons under suprahydrostatic pressure values. Microthermometry, sulfide and strontium isotopic compositions of the barite-sulfides veins indicate that all stages were formed by mixing between deep basinal fluids at 230°C, derived from cinerite dewatering, and formation water from overlying sedimentary cover channelized trough fault planes. We conclude to a polyphase history of fluid trapping during Permian synrift formation of the basin: (i) a first event, associated with the dextral strike-slip motion on faults, leads to a first sealing of the fault zone; (ii) periodic reactivations of fault planes and bedding-controlled shearing form the main mineralized ore bodies by the single action of fluid overpressure fluctuations, undergoing changes in local stress distribution and (iii) a final tectonic activation of fault linked to last basinal fluid and hydrocarbon migration during which shear stress restoration on fault plane is faster than fluid pressure build-up.

  6. Shallow burial dolomitisation of Middle–Upper Permian paleosols in an extensional tectonic context (SE Iberian Basin, Spain): Controls on temperature of precipitation and source of fluids

    OpenAIRE

    Benito Moreno, María Isabel; Horra del Barco, Raúl de la; López Gómez, José; Fernández Barrenechea, José María; Luque del Villar, Francisco Javier; Arche, Alfredo

    2011-01-01

    This work is focused on carbonate paleosols developed in three stratigraphic sections (Landete, Talayuelas and Henarejos) of theMiddle–Late Permian Alcotas Formation in the SE Iberian Basin. The Alcotas Formation, of alluvial origin, was deposited in semi-connected half-grabens developed during the early stages of the Permian–Triassic rifting stage that affected the Iberian Basin. The studied sections were located in two of these half-grabens, the Henarejos section being much clos...

  7. De la Expansion Desarrollista a las Extensiones Aulicas : Un Desafío Para la Gestión del Conocimiento en la Universidad Argentina

    OpenAIRE

    Garcia, Lucía B.; Marco, Maria Cecília Di; Zelaya, Marisa

    2006-01-01

    En esta ponencia nos proponemos abordar algunas consideraciones sobre la universidad como objeto de estudio en relación a los modos de producción y distribución del conocimiento. Para este propósito revisamos las transformaciones cuanti - cualitativas de la educación superior latinoamericana acaecidas desde mediados de los años 1950, momento en el que las universidades diseñadas para las élites comienzan una apertura hacia sectores sociales medios y bajos. Esta expansión matric...

  8. PERSONAS CORPORIZADAS, MULTIPLICIDADES Y EXTENSIONES: UN ACERCAMIENTO A LAS NOCIONES de cuerpo y persona entre los tobas (qom del chaco argentino

    Directory of Open Access Journals (Sweden)

    FLORENCIA C. TOLA

    2005-01-01

    Full Text Available ESTE ARTÍCULO ANALIZA LAS NOCIONES DE PERSONA Y CUERPO ENTRE LOS INDÍGENAS tobas (qom del Chaco argentino y despliega una serie de conceptos derivados del trabajo etnográfico. A partir de dos mitos centrales entre los tobas, analiza el papel de la posesión de un cuerpo en la definición de la persona y en la diferenciación entre humanos y no-humanos. Luego, aborda algunos de los criterios que definen la existencia de personas humanas y no-humanas que poseen o carecen de cuerpo. Seguidamente, analiza las características de la noción toba de persona por medio de la constitución colectiva del cuerpo en función de la circulación de componentes provenientes de otras personas-cuerpos.

  9. Analogue modelling for localization of deformation in the extensional pull-apart basins: comparison with the west part of NAF, Turkey

    Science.gov (United States)

    Bulkan, Sibel; Storti, Fabrizio; Cavozzi, Cristian; Vannucchi, Paola

    2017-04-01

    Analogue modelling remains one of the best methods for investigating progressive deformation of pull apart systems in strike slip faults that are poorly known. Analogue model experiments for the North Anatolian Fault (NAF) system around the Sea of Marmara are extremely rare in the geological literature. Our purpose in this work is to monitor the relation between the horizontal propagation and branching of the strike slip fault, and the structural and topographic expression resulting from this process. These experiments may provide insights into the geometric evolution and kinematic of west part of the NAF system. For this purpose, we run several 3D sand box experiments, appropriately scaled. Plexiglass sheets were purposely cut to simulate the geometry of the NAF. Silicone was placed on the top of these to simulate the viscous lower crust, while the brittle upper crust was simulated with pure dry sand. Dextral relative fault motion was imposed as well using different velocities to reproduce different strain rates and pull apart formation at the releasing bend. Our experiments demonstrate the variation of the shear zone shapes and how the master-fault propagates during the deformation, helping to cover the gaps between geodetic and geologic slip information. Lower crustal flow may explain how the deformation is transferred to the upper crust, and stress partitioned among the strike slip faults and pull-apart basin systems. Stress field evolution seems to play an interesting role to help strain localization. We compare the results of these experiments with natural examples around the western part of NAF and with seismic observations.

  10. The role of western Mediterranea tectonic evolution in the geometry of a karstic domain in the Betic Cordilleras (Sierra Gorda, Spain): Importance of a tardy extensional regime

    Science.gov (United States)

    Pistre, Séverin; Lopez-Chicano, Manuel; Pulido-Bosch, Antonio; Drogue, Claude

    1999-01-01

    Located in the central part of the Betic Cordilleras, the large carbonate Sierra Gorda Massif provides an example of a west-Mediterranean karstic aquifer. In spite of a complex polyphased tectonic history, the fracturing presents, from aerial views and at outcrop scale a quite organised geometry. Four fracture directions are found over the massif: N000-010, N050-070, N090-100 and N140-170. The statistical and geostatistical approach allows the characteristics (lengths, orientations) and the spatial structure for each fracture set to be determined. The NOOO-010 and N140-170 sets are grouped in packets whereas the two other sets are grouped in bands. The microtectonic study describes the evolution of the massif in the geodynamic context of this part of Mediterranea, distinguishing three recent stages of brittle tectonic activity in the massif: a WNW-ESE Middle Miocene compression, then a NNW-SSE to NW-SE compression with a poorly wrenching regime, and finally a probably pre-Quaternary N-S radial distension. This last stage is essential for the karstification of the massif and groundwater circulation. From the combined analysis of fracture network geometry and palaeostresses a multiple porosity model in agreement with hydrological observations made inside the massif can be proposed: in particular, the hectometric N090-100 (and N050-070) fractures which are essential for the network connectivity, and have a major drainage role at aquifer scale, while the N000-010 and N140-170 ones have a more local drainage role. This extensive tardy regime, which is for the first time described separately from the internal zones of the Cordilleras, must be considered as a significant phenomenon on a regional scale, and henceforth integrated in future geodynamic schemes of this part of Mediterranea.

  11. The Role of Low-Angle Extensional Tectonics, Flat Fracture Domains, and Gravity Slides in Hydrothermal and EGS Resources of the Western United States

    Energy Technology Data Exchange (ETDEWEB)

    Joseph Moore

    2011-08-24

    The Steamboat Springs geothermal system provides the most dramatic example of subhorizontal thermal-fluid aquifers in crystalline rock in the Basin and Range, but this is by no means an isolated case. Similar but more diffuse subhorizontal permeability has been reported at Roosevelt Hot Springs and Cove-Fort Sulphurdale, Utah; and a km-scale gravity-slide block channels injectate at Dixie Valley, Nevada. During the course of this phase of the project 2543 reports including text, figures and large format enclosures, 1428 maps, and 698 well logs were scanned. The information is stored in a Microsoft Access Database on the Geothermal Server. Detailed geologic cross sections of the Desert Peak geothermal field were developed to identify the structural controls on the geothermal system and locate possible fluid flow paths. The results of this work were published by Lutz and others (2009, Appendix 1) in the Stanford Reservoir Engineering Conference Proceedings.

  12. Tectonic stress evolution in the Pan-African Lufilian Arc and its foreland (Katanga, DRC): orogenic bending, late orogenic extensional collapse and transition to rifting

    Science.gov (United States)

    Kipata, M. L.; Delvaux, D.; Sebagenzi, M. N.; Cailteux, J.; Sintubin, M.

    2012-04-01

    Between the paroxysm of the Lufilian orogeny at ~ 550 Ma and the late Neogene to Quaternary development of the south-western branch of the East African rift system, the tectonic evolution of the Lufilian Arc and Kundelungu foreland in the Katanga region of the Democratic Republic of Congo remains poorly unknown although it caused important Cu-dominated mineral remobilizations leading to world-class ore deposits. This long period is essentially characterized by brittle tectonic deformations that have been investigated by field studies in open mines spread over the entire arc and foreland. Paleostress tensors were computed for a database of 1450 fault-slip data by interactive stress tensor inversion and data subset separation, and the relative succession of 8 brittle deformation events established. The oldest brittle structures observed are related to the Lufilian brittle compressional climax (stage 1). They have been re-oriented during the orogenic bending that led to the arcuate shape of the belt. Unfolding the stress directions from the first stage allows to reconstruct a consistent NE-SW direction of compression for this stage. Constrictional deformation occurred in the central part of the arc, probably during orogenic bending (Stage 2). After the orogenic bending, a sequence of 3 deformation stages marks the progressive onset of late-orogenic extension: strike-slip deformations (stages 3-4) and late-orogenic arc-parallel extension (stage 5). It is proposed that these 3 stages correspond to orogenic collapse. In early Mesozoic, NW-SE compression was induced by a transpressional inversion, interpreted as induced by far-field stresses generated at the southern active margin of Gondwana (stage 6). Since then, this region was affected by rift-related extension, successively in a NE-SW direction (stage 7, Tanganyika trend) and NW-SE direction (stage 8, Moero trend).

  13. Re-orientation of the extension direction and pure extensional faulting at oblique rift margins: Comparison between the Main Ethiopian Rift and laboratory experiments

    NARCIS (Netherlands)

    Corti, G.; Philippon, M.|info:eu-repo/dai/nl/370818636; Sani, F.; Keir, D.; Kidane, T.

    2013-01-01

    In this study, we draw on a unique combination of well-resolved fault-slip data and earthquake focal mechanisms to constrain spatial variations in style of faulting in the obliquely extending Main Ethiopian Rift, East Africa. These data show that both boundary and internal faults - oblique and

  14. Geology of the Curimatau medium region (Paraiba State, Brazil) and the emplacement of the Dona Ines granite associated to the Brasiliano transcurrent shear zones; Geologia da Regiao do Medio Curimatau (PB) e o alojamento do granito de Dona Ines associado a zonas de cisalhamento transcorrentes brasilianas

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Sergio Vieira Freire

    1996-12-31

    In an area of about 700 Km{sup 2} located in the northeast of Paraiba State and having as main point the town of Dona Ines, a geologic/structural mapping, a gravimetric survey and radiometric dating using the Rb/Sr method in whole rock and Sm.Nd model ages were undertaken in order to study and to understand the geology of this portion of terrain, the emplacement of the Dona Ines granitoids and its relationship with the enclosing rocks and the deformation acting at the time of the intrusion. The age of the pluton of Dona Ines was determined by the Rb/Sr whole rock method as 560 {+-} 20 Ma (end of Brasiliano Cycle in the region). Sm.Nd model ages in granitoids of Araras, Belem and Dona Ines have revealed paleoproterozoic ages for their crustal sources, as indicated by the negative {epsilon}{sub nd} of this rock 128 refs., 95 figs., 6 tabs., 7 maps

  15. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama -- Year 2. Annual report, March 1997--March 1998

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.

    1998-09-01

    Gilbertown Field is the oldest oil field in Alabama and has produced oil from fractured chalk of the Cretaceous Selma Group and glauconitic sandstone of the Eutaw Formation. Nearly all of Gilbertown Field is still in primary recovery, although waterflooding has been attempted locally. The objective of this project is to analyze the geologic structure and burial history of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas in order to suggest ways in which oil recovery can be improved. Indeed, the decline of oil production to marginally economic levels in recent years has made this type of analysis timely and practical. Key technical advancements being sought include understanding the relationship of requisite strain to production in Gilbertown reservoirs, incorporation of synsedimentary growth factors into models of area balance, quantification of the relationship between requisite strain and bed curvature, determination of the timing of hydrocarbon generation, and identification of the avenues and mechanisms of fluid transport.

  16. El Margen Atlántico Ibérico al W de Galicia. Evolución en régimen extensional y sedimentación. (Resultados preliminares del Leg. 103, Ocean Drilling Program.)

    OpenAIRE

    Boillot, G; Winterer, E. L.; Meyer, A. W.; Applegate, J.; Baltuck, M.; Bergen, J. A.; Davies, T. A.; Dunham, K.; Evans, C A; Girardeau, J.; Goldberg, D; Haggerty, J; Jansa, L F; J. A. Johnson; Kasahara, J.

    1986-01-01

    Leg 101 of the Ocean Drilling Program (ODP) was devoted discovering the tectonic and sedimentary evolution of the Atlantic Margin of the lberian Peninsula. A transect of five sites, with a total of 14 drill-holes was undertaken to the South of the Galicia Bank on the seaward edge of the margin. The data obtained revealed a complex history of subsidence and rifting preceding the initiation of sea floor spreading between Newfoundland and Iberia. The main findings include: 1) The Upper Jurassic-...

  17. Reply to the discussion by F. Gutiérrez, P. Lucha, J. Guerrero, M. Gutiérrez and D. Carbonel on the article `Paleoseismological analysis of an intraplate extensional structure: the Concud fault (Iberian Chain, eastern Spain)'

    Science.gov (United States)

    Lafuente, P.; Arlegui, L. E.; Liesa, C. L.; Simón, J. L.

    2012-03-01

    This reply tackles the three main points of discussion of the comment, carefully distinguishing those constructive contributions from the potentially confusing ones. (1) We accept that we should have utilised previously published datings of the middle terrace, even if we consider them to be less reliable than the used ones, so broadening the slip-rate range from 0.23-0.33 mm/y to 0.16-0.33 mm/y. Nevertheless, their revision of the post-middle terrace slip rate charges us two contradictory imputations: that we underestimate the throw in a 25% (36 m vs. 47 m) and that this results in `anomalously high slip rates'. We analyse the adduced error, and we confirm our initial estimate based on our more reliable stratigraphic marker, so rejecting both criticisms. (2) About the paleoseismological interpretation at Los Baños trench, we appreciate the hint about displacement partitioning on the master fault and in our hypothetical blind normal fault during the last three events; however, such partitioning was already considered in our retrodeformation analysis. We believe that there is enough evidence for the two events questioned by the commenters, as well as for the interpretation of the colluvial wedge that evidences one of them. (3) With respect to the fault affecting the youngest terrace: (a) both traces exposed on orthogonal road-cut slopes belong to the same normal fault, and we prove it by means of basic structural constructions, and (b) it does not exhibit any feature suggesting a non-tectonic origin, as the commenters state.

  18. El Margen Atlántico Ibérico al W de Galicia. Evolución en régimen extensional y sedimentación. (Resultados preliminares del Leg. 103, Ocean Drilling Program.

    Directory of Open Access Journals (Sweden)

    Boillot, G.

    1986-06-01

    Full Text Available Leg 101 of the Ocean Drilling Program (ODP was devoted discovering the tectonic and sedimentary evolution of the Atlantic Margin of the lberian Peninsula. A transect of five sites, with a total of 14 drill-holes was undertaken to the South of the Galicia Bank on the seaward edge of the margin. The data obtained revealed a complex history of subsidence and rifting preceding the initiation of sea floor spreading between Newfoundland and Iberia. The main findings include: 1 The Upper Jurassic-Lowermost Cretaceous shallow-water carbonate platform are the first Messozoic deposits at the margin. The «basement seismic reflector» is made-up of these carbonates. 2 The platform drowning, tilting of fault blocks and rapid subsidence preceded the spreading by as much as 25 million years. 3 A ridge of serpentiniced peridotites is located near the boundary between the oceanic and continental crusts. 4 The seismic reflector «S» does not, as widely believed represent a ductile-brinle boundary within the continental crust but is instead a reflector at the base of the synrift sediments.

    La campaña oceanográfica 103 del Ocean Drilling Program (ODP ha estado dedicada a dilucidar la evolución tectónica y sedimentación del Margen Atlántico-Ibérico. Se realizaron un total de 14 sondeos., en cinco puntos de posicionamiento, sobre el extremo más profundo del margen; al S del Banco de Galicia. Los resultados obtenidos revelan que previamente al inicio de la expansión oceánica entre Terranova e Iberia ocurrió una historia compleja de distensión cortical, fracturación y subsidencia asociadas. Los resultados fundamentales son los siguientes: 1 Carbonatos de plataforma marina somera, de edad Jurásico superior-Cretáceo basal constituyen los primeros depósitos mesozóicos en ese ámbito del margen y dan lugar a un reflector sísmico considerado interiormente como basamento, 2 El hundimiento de la plataforma, fallamiento y basculamiento de los bloques ocurre desde 25 m.a. antes de iniciarse la acreción oceánica. 3 En el límite entre corteza oceánica-corteza continental se ubica una cresta constituida por peridotitas serpetinizadas. 4 El reflector sísmico «S», generalmente considerado como el límite dúctil-frágil en la corteza continental, corresponde realmente a la base de los depósitos sinrift.

  19. Analysis of the 3 and 4 cycles with extensions in the operation of the CNLV U-1; Analisis de los ciclos 3 y 4 con extensiones en la operacion de la CNLV U-1

    Energy Technology Data Exchange (ETDEWEB)

    Montes T, J.L.; Torres A, C.; Perusquia C, R. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    1992-08-15

    The objective of the report is the comparison of the radial distributions of burned in the core among the results of the simulation of the Laguna Verde Central U-1 reactor during the operation of the cycles 1 to 4 and the data of the operation with information provided by the fuel supplier. (Author)

  20. Spatial distribution of mollusks in the intertidal zone of sheltered beaches in southeastern of Brazil

    Directory of Open Access Journals (Sweden)

    Eliane P. de Arruda

    2003-06-01

    Full Text Available The spatial distribution of mollusks in the intertidal zone was examined monthly from August 1995 through July 1997, in Enseada, Barra Velha and Araçá beaches in southeastern of Brazil. One study sector was selected in Enseada and Barra Velha, and two sectors in Araçá (Araçá I and Araçá II. The sectors were 10 m wide and equivalent in length to the width of the intertidal zone. Each sector was divided into three horizontal levels: lower, middle and upper, where the samples were taken with a cylinder corer with a base area of 0.16 m². In order to characterize the intertidal environment in these areas, some environmental variables were analyzed. In general, the mollusks were distributed in the sectors as follows: Enseada - Olivella minuta (Link, 1807 in the lower level and Tagelus plebeius (Lightfoot, 1786 in the upper level; Araçá I - O. minuta in the lower level, Tellina lineata Turton, 1819 and Anomalocardia brasiliana (Gmelin, 1791 in the middle levels; Araçá II - Cerithium atratum (Born, 1778 in the lower level, O. minuta in the lower and middle levels, and A. brasiliana and Corbula caribaea Orbigny, 1842 in the middle level; Barra Velha - Tagelus divisus (Spengler, 1794, Lucina pectinata (Gmelin, 1791 and Tellina versicolor De Kay, 1843 in the lower level, and A. brasiliana and Macoma constricta (Brugüìere, 1792 in the upper level. The intertidal zone of the study sectors could be divided into two biological zones: the upper zone, where T. plebeius, A. brasiliana and M. constricta were more abundant; and the lower zone, where O. minuta, C. atratum, T. lineata, T. versicolor, C. caribaea, T. divisus and L. pectinata were abundant.

  1. Flow of Polymer Melts in Plane- and Axi-Symmetric Converging Dies

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Linding; Kjær, Erik Michael; Haudrum, Jan

    1998-01-01

    The extensional flow has considerable influence on the pressure loss in converging flows, which are present in both extrusion and injection moulding. Both plane- and axi-symmetric converging flows have been studied with LDPE, HDPE and PS. The transient extensional viscosities are determined in all...... cases. The extensional viscous description used is the one proposed by Cogswell $LB@3$RB@. The extensional viscosities in the two different flow fields are compared. The plane-symmetric extensional viscosity is found to be larger than the axi-symmetric for the HDPE melt. The two viscosities...

  2. Flow of Polymer Melts in Plane- and Axi-symmetric Converging Dies

    DEFF Research Database (Denmark)

    Lauridsen, Carsten Linding; Kjær, Erik Michael; Haudrum, Jan

    1997-01-01

    The extensional flow has considerable influence on the pressure loss in converging flows, which are present in both extrusion and injection moulding. Both plane- and axi-symmetric converging flows have been studied with LDPE, HDPE and PS. The transient extensional viscosities are determined in all...... cases. The extensional viscous description used is the one proposed by Cogswell (3). The extensional viscosities in the two now different flow fields ate compared. The plane-symmetric extensional viscosity is found to be larger than the axi-symmetric for the HDPE melt. The two viscosities are comparable...

  3. Pinch-off dynamics, dripping-onto-substrate rheometry and printability of dilute and semi-dilute polymer solutions

    Science.gov (United States)

    Dinic, Jelena; Jimenez, Leidy Nallely; Biagioli, Madeleine; Sharma, Vivek

    Many advanced manufacturing technologies like inkjet and 3D printing, nano-fiber spinning involve complex free-surface flows, where both shear and extensional rheology affect processability. In applications that involve progressive thinning and break-up of a fluid column or sheet into drops, the dominant flow within the filament is extensional in nature. Polymeric fluids exhibit a much larger resistance to flow in an elongational flow field than Newtonian fluids with same shear viscosity. We use dripping-onto-substrate (DoS) extensional rheometry technique for examining the influence of extensibility, flexibility and concentration on pinch-off dynamics and extensional rheology response of aqueous polyethylene oxide (PEO) solutions, aqueous polyacrylamide (PAM) solutions and aqueous 2-Hydroxyethyl cellulose (HEC) solutions. Both extensional relaxation time and the transient extensional viscosity of dilute and semi-dilute solutions display concentration-dependent behavior that is strikingly different from the response observed in typical shear rheology measurements.

  4. O transitar entre a Matemática do Matemático, a Matemática da Escola e a Matemática do GeoGebra: um estudo de como professores de Matemática lidam com as possibilidades e limitações do GeoGebra

    OpenAIRE

    Gonçalves, William Vieira [UNESP

    2016-01-01

    Este trabalho tem como principal objetivo demonstrar que o GeoGebra apresenta uma maneira diferente de produzir significados matemáticos, com isso, sugerindo sua relevância para o ensino de matemática e de se discutir sua linguagem, possibilidades e limitações. A base inicial da pesquisa foi um estudo imersivo em diferentes comunidades virtuais, literatura acadêmica correlata, cursos específicos do software, produção e análise de diferentes construções dinâmicas. Por fim, optou-se por delimit...

  5. Problemáticas psicossociais da abordagem da noção de sujeito

    OpenAIRE

    Jodelet, Denise; Loprete, Luciano

    2015-01-01

    O presente artigo trata da importância da questão do sujeito nas representações sociais. Para tanto, repassa alguns modelos da psicologia social e alude às novas perspectivas sobre o sujeito desenvolvidas nas ciências sociais e humanas. Feito um breve panorama do uso da categoria sujeito na história dessa disciplina, com destaque a seu retorno às ciências sociais nos anos 1990 e a noções correlatas, como "ator" e "agente", aponta-se a necessidade de trabalhar com a noção de "subjetivação" em ...

  6. A rastreabilidade bovina no Brasil : histórico, evolução e perspectiva de futuro

    OpenAIRE

    Mota, Ézio Gomes da

    2011-01-01

    Uma série de acontecimentos ocorridos na Europa e no mundo, relacionados a doenças dos animais e a contaminação dos alimentos como: o “Mal da Vaca Louca” (Encefalopatia Espongiforme Bovina – EEB) e seus registros da enfermidade correlata nos seres humanos, contaminação por dioxinas, aftosa e outros eventos, deixaram o mundo em alerta em relação aos alimentos de origem animal, especialmente de bovinos. Como consequência e com os objetivos principais de aumentar a segurança dos alimentos e a cr...

  7. "Tout autre est tout autre": direitos humanos e perspectivismo semântico-transcendental

    Directory of Open Access Journals (Sweden)

    Oliveira Junior, Nythamar Hilario Fernandes de

    2006-01-01

    Full Text Available A impossibilidade de se fundamentar os direitos humanos hoje de maneira satisfatória, sem recorrer a modelos essencialistas ou metafísicos, parece correlata à universalidade de sua defesa e promoção. Uma abordagem fenomenológica favorece uma leitura perspectivista da alteridade, tornando altamente defensável e razoável que se aplique uma semântica transcendental ao problema da fundamentação dos direitos humanos

  8. Responsabilidade Civil decorrente do Abandono Afetivo

    Directory of Open Access Journals (Sweden)

    Welington Oliveira de Souza Costa

    2015-11-01

    Full Text Available O presente artigo jurídico tem por finalidade demonstrar a aplicabilidade do instituto da responsabilidade civil decorrente do abandono afetivo aos genitores que negligenciem seu cuidado para com os filhos, indenizando-os em razão do dano decorrente. Para tanto, será demonstrada a possibilidade de associação do instituto da responsabilidade dentro do direito de família e os dispositivos aplicáveis, inclusive aqueles relativos à solução de conflitos de princípios, apontando, ainda, a jurisprudência correlata.

  9. Morfología de semillas y desarrollo post-seminal de especies de Comanthera (Eriocaulaceae)

    OpenAIRE

    Dugarte Corredor, Blanca Auxiliadora; Escobar Escobar, Diego Fernando; Scatena, Vera Lúcia

    2015-01-01

    Comanthera brasiliana, C. magnifica y C. suberosa (Eriocaulaceae) forman parte de la lista de especies amenazadas de extinción en Brasil, debido a su alto grado de endemismo y a la recolecta indiscriminada. Estas tres especies junto con C. brunnea y C. linearis constituyen el clado de Comanthera magnifica. Se estudió la germinación, la morfología de semillas y el desarrollo post-seminal de las cinco especies, buscando caracterizar morfológica y anatómicamente las semillas y estadios posterior...

  10. COZINHEIRO IMPERIAL - Ou a nova arte do cozimento e do copeiro em todos os seus ramos

    Directory of Open Access Journals (Sweden)

    Daniela Pereira de Vargas

    2011-12-01

    Full Text Available Resumo: O Cozinheiro Imperial Ou Nova Arte Do Cozinheiro E Do Copeiro Em Todos Os Seus Ramos é uma referencia tanto na culinária como na bibliografia brasileira, por tratar-se do primeiro livro de receitas editado no Brasil. De autor anônimo, foi reeditado em 1996 pela Best Seller. A Universidade de São Paulo digitalizou os originais, que hoje são parte de sua Coleção Brasiliana. Pela importância cultural do material, ele é destacado nesta edição de RRV. Palavras chave: Gastronomia. Cultura Brasileira. Cozinheiro Imperial. 

  11. Geochronology and structuring of the Ceara State: Borborema Province northwestern part, NE Brazil; Geocronologia e estruturacao do estado do Ceara: NW da provincia Borborema, NE, Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Fetter, A.; Van Schmus, W.R. [Kansas Univ., Lawrence, KS (United States). Dept. of Geology; Santos, Ticiano J. Saraiva dos [UNESP, Rio Claro, SP (Brazil). Inst. de Geociencias e Ciencias Exatas; Arthaud, M.; Nogueira Neto, J. [Ceara Univ., Fortaleza, CE (Brazil). Dept. de Geologia

    1997-12-31

    The work confirms that the geochronological new data U/Pb in zircon and Samarium/Neodymium from the Ceara State furnished a refined chronology of the geological activity in the NW part of the Borborema Province, indicating an evolutive history since 2,78 Ga and 532 Ma. Furthermore, these data facilitated the different crust domain outlines in the region, putting age maximum limits in the pre-brasilianas supracrusts rocks deposition, and evidencing the epoch and duration of the Brasiliano magmatism and metamorphism in the northwest part of the State

  12. Francisco Carlos Teixeira da Silva, Karl Shurster Sousa Leão, Igor Lapsky (organizadores), O Cinema Vai à Guerra

    OpenAIRE

    Santiago Júnior, Francisco das Chagas F.

    2016-01-01

    O Cinema vai à Guerra, libro curato da Francisco Carlos T. da Silva, Karl Schurster Leão e Igor Lapsky si inserisce nel solco della tradizione storiografica brasiliana attenta alla relazione fra storia e cinema. Il tema della guerra nel cinema non è nuovo né nello scenario internazionale, né in Brasile, non essendo, peraltro, monopolio della ricerca storica. La maggior parte delle monografie precedenti, infatti sono state scritte – in ambito brasiliano – da studiosi o critici cinematografici....

  13. Episodic crustal growth in the Bundelkhand craton of central India ...

    Indian Academy of Sciences (India)

    1

    Sharma (1998) invoked an alternating extensional and compressional environment in the. 418 tectnomagmatic evolution of the Bundelkhand carton wherein the extensional regime resulted in. 419 the evolution of volcano sedimentary greenstone belts and opening of the basins and the. 420 compressional regime resulted ...

  14. Mafic dykes of the Vestfold Hills, East Antarctica. An analysis of the emplacement mechanism of tholeiitic dyke swarms and of the role of dyke emplacement during crustal extension

    NARCIS (Netherlands)

    Hoek, J.D.

    1994-01-01

    Mafic dyke swarms are common in Proterozoic continental crustal terrains. Although it is generally recognized that parallel mafic dyke swarms are formed in extensional tectonic settings and that they accommodate in the order of 10% of extensional strain, the tectonics and geodynamics of dyke

  15. Arc parallel extension in Higher and Lesser Himalayas, evidence ...

    Indian Academy of Sciences (India)

    The existence of E–W extensional features from northeast (NE) Himalaya is poorly documented. Our investigation in the western part of Arunachal Himalaya provides evidences of active Quaternary E–W arc-parallel extensional features in the Higher and Lesser Himalayas. They are represented by arcperpendicular normal ...

  16. Non-inertial flow of dilute polymer solutions in a sudden contraction

    Science.gov (United States)

    1984-01-01

    Non-inertial flow of dilute polymer solutions in a sudden contraction was examined to interpret clearly the extensional-thickening behavior of the solutions. Experimental conditions were reviewed, and the velocity field and axial extensional velocities were discussed. A linear hydrolyzed polyacrylamid (HPAM) was dissolved in a Newtonian fluid to make the polymer solution. The velocities were measured with a laser Doppler velocimeter.

  17. Identification and characterisation of the dominant Pseudo-nitzschia species (Bacillariophyceae along the NE Spanish coast (Catalonia, NW Mediterranean

    Directory of Open Access Journals (Sweden)

    Sonia Quijano-Scheggia

    2008-06-01

    Full Text Available Potentially toxic species of the genus Pseudo-nitzschia were studied along the Spanish NW Mediterranean coast from January 2005 to May 2006. Observation in electron microscopy revealed the presence of Pseudo-nitzschia brasiliana, P. calliantha, P. delicatissima, P. fraudulenta, P. multistriata and P. pungens. Several strains were isolated from coastal waters and their clonal cultures were compared by combined techniques, including light and electron microscopy and internal transcribed spacer (ITS-1, 5.8S and ITS-2 rDNA sequencing. Cultured isolates were submitted to HPLC analysis of pigments to evaluate the possibility of taxonomic discriminations by means of a simple chemotaxonomic approach. The genus Pseudo-nitzschia showed high cell concentrations during most of the year, but the population initiated a sharp decline at all stations in the period between April and May. P. delicatissima with P. calliantha were found at the northern stations between February and April, and at the southern stations between August and November. P. brasiliana and P. multistriata were only occasionally detected in the southern region. None of the environmental variables considered was significant to explain the observed spatial and temporal distributions of Pseudo-nitzschia species in the area studied. Differences in the growth rate and cell yield of the species indicate that biotic factors may play a role in the observed distributional patterns.

  18. Conhecimento tradicional das marisqueiras de Barra Grande, área de proteção ambiental do delta do Rio Parnaíba, Piauí, Brasil

    Directory of Open Access Journals (Sweden)

    Simone Tupinambá Freitas

    2012-08-01

    Full Text Available Na comunidade de Barra Grande localizada no litoral do Piauí, as mulheres dos pescadores, conhecidas localmente como marisqueiras, extraem do manguezal vários tipos de moluscos para comercialização e em maior escala para a subsistência. Dados sobre a atividade de mariscagem, conceitos de conservação e aspectos socioeconômicos do contexto em que ocorre a atividade de cata dos moluscos, foram revelados após a aplicação de protocolos estruturados e semiestruturados. O molusco bivalve Anomalocardia brasiliana (Gmelin, 1791, popularmente denominado de marisco, é caracterizado por ser um importante recurso para a subsistência, sendo o mais coletado pela comunidade, seguido da Mytella charruana (d'Orbigny, 1842, o sururu, explorado para a comercialização por ter o maior valor de mercado. O conhecimento das marisqueiras sobre A. brasiliana foi comparado com literatura especializada, muitas vezes mostrando-se em harmonia com esta. Demonstra-se assim que o conhecimento tradicional deve ser valorizado para delineamento de programas de gestão de recursos pesqueiros da região. Quanto aos modos de pensar, foi revelado que 82,81% das marisqueiras praticam manejo para a conservação da A. brasiliana ao coletar apenas os indivíduos de maior tamanho, e 80,86% consideram que não existe poluição nos pontos de coletas. O surgimento de uma Associação exclusiva e cooperativa para as marisqueiras é necessário para a valorização do trabalho por elas desenvolvido, visto que há uma média estimada de 351 kg de carne sendo extraídos mensalmente.En la comunidad de Barra Grande, situada en la costa del estado de Piaui, las esposas de los pescadores, localmente llamadas de "marisqueiras", extraen de los manglares diversos tipos de moluscos para su comercialización, haciendo de esta actividad en una fuente de subsistencia. Informaciones detalladas y sistemáticas sobre la actividad de cosecha de mariscos, del contexto en el que se desarrolla la

  19. Une plate-forme en distension, témoin de phases pré-accrétion téthysienne en Afrique du Nord pendant le Toarcien Aalénien (synclinal Iguer Awragh Afennourir, Moyen Atlas occidental, Maroc)A pre-accretional extensional platform of the North African Tethys during the Toarcian Aalenian (Iguer Awragh Afennourir syncline, western Middle Atlas, Morocco)

    Science.gov (United States)

    El Hammichi, Fatima; Elmi, Serge; Faure-Muret, Anne; Benshilil, Khadija

    2002-10-01

    A stratigraphic study and mapping allow defining the particular features of this area of the southwestern Middle Atlas (Morocco) during the Toarcian and the Aalenian. Numerous spectacular variations in thickness and facies are documented by the discovery of coralline build-ups dated to the Late Toarcian. They occur along the palaeostructures. Development of the structures occurred in several stages: (1) initial differentiation during the Early and Middle Toarcian; (2) homogenisation during the Late Toarcian, after the construction of the reefs. The Aalenian history is similar: differentiation (Early Aalenian)-homogenisation (Middle to Late Aalenian). Two palaeostructural trends are evident: SW-NE and transverse SSW-NNE to south-north. These caused separation of several subbasins, which alternatively deepened and shallowed, probably due to the tilting of several blocks to the southwest. To cite this article: F. El Hammichi et al., C. R. Geoscience 334 (2002) 1003-1010.

  20. First Class Call Stacks: Exploring Head Reduction

    Directory of Open Access Journals (Sweden)

    Philip Johnson-Freyd

    2016-06-01

    Full Text Available Weak-head normalization is inconsistent with functional extensionality in the call-by-name λ-calculus. We explore this problem from a new angle via the conflict between extensionality and effects. Leveraging ideas from work on the λ-calculus with control, we derive and justify alternative operational semantics and a sequence of abstract machines for performing head reduction. Head reduction avoids the problems with weak-head reduction and extensionality, while our operational semantics and associated abstract machines show us how to retain weak-head reduction's ease of implementation.

  1. Molecular Rheology of Complex Fluids

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik Koblitz

    fluids as a function of molecular chemistry has attracted a long history of collaboration between industry and academia. In industrial polymer processes, there is usually a combination of both shear and extensional flows. In some processing operations such as blow molding and fiber spinning, extensional......–state viscosity between melts and solutions is still an open question. Branched polymer melts have more complex molecular structures. A stress maximum during the start–up of uniaxial extensional flow was reported in 1979 for a low–density polyethylene (LDPE) melt. Subsequently observations of a steady stress...

  2. A participação social como diretriz estratégica do SUS: a psicanálise operando em lógicas coletivas na saúde

    OpenAIRE

    Coaracy Neto, Augusto Ribeiro

    2017-01-01

    Esta pesquisa procura realizar uma interlocução entre psicanálise e Clínica Ampliada. O objetivo dessa interlocução é discutir a participação social enquanto diretriz estratégica do SUS, na perspectiva de uma Democracia Participativa. Para isso, especificam-se as noções de sujeito correlatas à psicanálise e à Clínica Ampliada, o que também delimita seus métodos clínicos. Para realçar as características do sujeito da Clínica Ampliada, estudam-se os trabalhos de Gastão Wagner e R...

  3. Diversity and similarity of trophic system "Barn Owl - terrestrial mammals" in the volcanic districts of Latium (Italy / Diversità ed affinità dei sistemi trofici "Tyto alba - mammiferi terragnoli" nei comprensori vulcanici del Lazio

    Directory of Open Access Journals (Sweden)

    Fiorella Aste

    1987-07-01

    Full Text Available Abstract Bony remains of about ten thousands small terrestrial mammals preyed by Barn Owl in six volcanic districts of Latium were examined and relevant biocoenotic parameters (such as biotic diversity, thermoxerophily index, Renkonen's and Faith's indexes calculated. Diversity values exhibit no apparent correlation with a number of environmental and biocoenotic parameters of non-anthropic origin - i.e.: district age, height on sea level, latitude, biocoenotic (Renkonen's and faunistic (Faith's affinities. Conversely, a clearly significant, negative correlation with landscape anthropization was shown, revealing the importance of man's impact in shaping functional connections in the terrestrial communities of studied region. Riassunto L'esame del sistema trofico in argomento in 6 distretti vulcanici del Lazio ha posto in evidenza che la diversità biotica è significativamente e inversamente correlata con l'antropizzazione territoriale, ma non con altri fattori ambientali di origine anantropica.

  4. Ação coletiva, governança democrática e accountability social na construção de cidades sustentáveis : os casos de Florianópolis, Ilhabela e Ilhéus

    OpenAIRE

    Dahmer, Jeferson

    2014-01-01

    A América Latina presenciou, nas duas últimas décadas, o surgimento de iniciativas da sociedade civil voltadas à qualificação da participação cidadã, à produção e à sistematização de informações, ao desenvolvimento de pesquisas de percepção cidadã e ao monitoramento do poder público. Expressões desse fenômeno são a Red de Ciudades Cómo Vamos, a Red Latino-americana por Ciudades y Territorios Justos, Democráticos y Sustentables e a sua correlata brasileira. Característi...

  5. Audiovisual translation research in Brazil and in Europe

    Directory of Open Access Journals (Sweden)

    Lina Alvarenga

    2002-01-01

    Full Text Available This article presents contributions from three translation scholars aimed at discussing the present situation of audiovisual translation research in Brazil and in Europe. The first contribution deals with issues concerning both contexts whereas the two others focus on local research issues.Este artigo apresenta contribuições de três pesquisadoras de tradução que discutem a situação atual das pesquisas sobre tradução audiovisual no Brasil e na Europa. A primeira contribuição trata de questões correlatas aos dois contextos enquanto que as duas outras enfocam questões de pesquisa de interesse local.

  6. A transexualidade no/pelo judiciário mineiro: um estudo dos julgados do TJMG correlatos à transexualidade no período de 2008 a 2010

    OpenAIRE

    Coacci, Thiago

    2016-01-01

    RESUMO: O presente artigo objetiva identificar o tratamento dado, pelo poder judiciário, à transexualidade e a suas questões correlatas por meio de uma análise de julgados do Tribunal de Justiça de Minas Gerais (TJMG), no período correspondente a janeiro de 2008 e junho de 2010. Procurou-se identificar: a) as razões mais frequentes pelas quais esses indivíduos recorrem à justiça; bJ como ps/as magistrados/as têm julgado esses casos; c) analisar, por um ponto de vista jurídico e com auxílio da...

  7. O conhecimento científico em turismo no Brasil

    OpenAIRE

    Momm,Christiane Fabíola

    2009-01-01

    Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências da Educação, Programa de Pós-Graduação em Ciência da Informação, Florianópolis, 2009. Estudo que objetiva investigar a institucionalização científica do campo de estudo do Turismo e áreas correlatas no Brasil, a partir das referências bibliográficas das dissertações produzidas em quatro Programas de Pós-Graduação, no período de 2000 a 2006. Os objetivos específicos são: recuperar as referências bibliográfic...

  8. Turbid Flows and Their Deposits on Slopes with Minibasins : A Modelling Approach

    NARCIS (Netherlands)

    Wang, X.

    2015-01-01

    Passive continental margins display a great diversity of seafloor bathymetries induced by gravity driven extensional faulting and compressional folding, as well as diapiric movements of salt or mud. In many diapirically controlled settings, slope bathymetries are complicated and characterized by

  9. An Evaluation of Knowledge Base Systems for Large OWL Datasets

    National Research Council Canada - National Science Library

    Guo, Yuanbo; Pan, Zhengxiang; Heflin, Jeff

    2004-01-01

    .... To this end, we have developed the Lehigh University Benchmark (LUBM). The benchmark is intended to evaluate knowledge base systems with respect to extensional queries over a large dataset that commits to a single realistic ontology...

  10. Near-surface Heating of Young Rift Sediment Causes Mass Production and Discharge of Reactive Dissolved Organic Matter

    National Research Council Canada - National Science Library

    Yu-shih Lin; Boris P Koch; Tomas Feseker; Kai Ziervogel; Tobias Goldhammer; Frauke Schmidt; Matthias Witt; Matthias Y Kellermann; Matthias Zabel; Andreas Teske; Kai-uwe Hinrichs

    2017-01-01

    .... Here we present evidence showing that near-surface heating of sediment in the Guaymas Basin, a young extensional depression, causes mass production and discharge of reactive dissolved organic matter (DOM...

  11. Crustal structure and tectonics of the Ninetyeast Ridge from seismic and gravity studies

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Neprochnov, Y.P.; Rao, D.G.; Grinko, B.N.

    of compressional and extensional stresses applied along the 89 degrees E Fracture Zone (FZ). The stresses are interpreted as resulting from multiple ridge jumps of Wharton spreading centers during the Late Cretaceous and middle Eocene. The velocity-depth model...

  12. Project Title: Geothermal Play Fairway Analysis of Potential Geothermal Resources in NE California, NW Nevada, and Southern Oregon: A Transition between Extension$-$Hosted and Volcanically$-$Hosted Geothermal Fields

    Energy Technology Data Exchange (ETDEWEB)

    McClain, James S. [Univ. of California, Davis, CA (United States). Dept. of; Dobson, Patrick [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Glassley, William [Univ. of California, Davis, CA (United States). Dept. of Earth and Planetary Sciences; Schiffman, Peter [Univ. of California, Davis, CA (United States). Dept. of Earth and Planetary Sciences; Zierenberg, Robert [Univ. of California, Davis, CA (United States). Dept. of Earth and Planetary Sciences; Zhang, Yingqi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Conrad, Mark [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Siler, Drew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gasperikova, Erika [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spycher, Nicolas F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2016-09-30

    Final report for the UCD-LBNL effort to apply Geothermal Play Fairway Analysis to a transition zone between a volcanically-hosted and extensionally-hosted geothermal. The project focusses on the geothermal resources in northeastern California.

  13. Responsive copolymers for enhanced petroleum recovery. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-02-01

    This report describes the development of new synthetic polymers to be used in petroleum recovery. The solution behavior and rheology properties, as well as new techniques for measuring extensional flow behavior under controlled conditions in packed bed geometries is described.

  14. Discrete Element Modeling of Dike-induced Deformation

    Science.gov (United States)

    Wyrick, D. Y.; Smart, K. J.

    2009-03-01

    Discrete element models of dike-induced deformation suggest the most distinctive topographic signature of an underlying dike are parallel ridges formed by contractional folding bounding a trough rather than an extensional fault-bounded graben.

  15. Avaliação auditiva em músicos de frevo e maracatu

    Directory of Open Access Journals (Sweden)

    Andrade Ana I.A.

    2002-01-01

    Full Text Available Objetivos: Medir o nível de pressão sonora a que são expostos os músicos dos blocos carnavalescos, especificamente dos ritmos de frevo e maracatu, levantar os níveis mínimos de audição dos músicos, conhecer seus hábitos auditivos e queixas correlatas e comparar os resultados entre os grupos. Forma de estudo: Clínico prospectivo randomizado. Material e método: A casuística constituiu-se de 19 músicos do grupo de frevo e 31 músicos do grupo de maracatu, de 12 a 71 anos de idade. Foi aplicado um questionário com o intuito de conhecer os hábitos auditivos e as queixas correlatas dos músicos e realizada audiometria tonal por via aérea e via óssea. Resultados: Os resultados mostraram que os hábitos mais citados foram os de freqüentar discotecas e o uso de walkman, e as principais queixas relatadas foram tontura e zumbido. A configuração de curvas audiométricas sugestivas de PAIR foi de 42,10% e 16,13%, nos grupos de frevo e de maracatu, respectivamente. No grupo de frevo, a idade, o tempo de trabalho como músico e o tempo de exposição à música influenciaram a ocorrência das alterações auditivas. Conclusão: É necessária a implantação de Programa de Conservação Auditiva, pela falta de consciência destes músicos aos riscos inerentes de instalação de perda auditiva decorrente da exposição à música intensa na cidade de Olinda-PE.

  16. Arcabouço geofísico, isostasia e causas do magmatismo cenozóico da província Borborema e de sua margem continental (Nordeste do Brasil)

    OpenAIRE

    OLIVEIRA, Roberto Gusmão de

    2008-01-01

    A Província Borborema (PB) é um domínio geológico-estrutural localizado no Nordeste do Brasil, limitado a sul pelo Cráton do São Francisco, a oeste pela Bacia do Parnaíba e a norte e leste pelas bacias costeiras. Embora bastante estudada por geologia de superfície, na PB ainda estão em aberto aspectos importantes de sua evolução, notadamente: i) a sua compartimentagem tectônica após a Orogênese Brasiliana, ii) a arquitetura da margem continental implantada no Cretáceo, iii) as propr...

  17. Phylogeny of the sea hares in the aplysia clade based on mitochondrial DNA sequence data

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Monica; Collins, Timothy; Walsh, Patrick J.

    2004-02-20

    Sea hare species within the Aplysia clade are distributed worldwide. Their phylogenetic and biogeographic relationships are, however, still poorly known. New molecular evidence is presented from a portion of the mitochondrial cytochrome oxidase c subunit 1 gene (cox1) that improves our understanding of the phylogeny of the group. Based on these data a preliminary discussion of the present distribution of sea hares in a biogeographic context is put forward. Our findings are consistent with only some aspects of the current taxonomy and nomenclatural changes are proposed. The first, is the use of a rank free classification for the different Aplysia clades and subclades as opposed to previously used genus and subgenus affiliations. The second, is the suggestion that Aplysia brasiliana (Rang, 1828) is a junior synonym of Aplysia fasciata (Poiret, 1789). The third, is the elimination of Neaplysia since its only member is confirmed to be part of the large Varria clade.

  18. Use of fishing resources by women in the Mamanguape River Estuary, Paraíba state, Brazil.

    Science.gov (United States)

    Rocha, Michelle S P; Santiago, Idalina M F L; Cortez, Creuza S; Trindade, Priscila M; Mourão, José S

    2012-12-01

    We evaluated the appropriation and use of fishing resources by women residing near the Mamanguape River Estuary (MRE), Paraíba state, Brazil. Were used combinations of qualitative (interviews and direct observations) and quantitative methods (use value and corrected principal use concordance). Thirty women were interviewed and reported the use of 41 species (30 fish, 8 crustaceans, and 3 mollusks), mainly for local consumption and sale. The species with the highest use value were Genidens genidens (0.7), Callinectes exasperatus (0.73) and Anomalocardia brasiliana (0.46). The diversity of resources exploited demonstrates the importance of the mangrove ecosystem to MRE families, and the data gathered can serve as a basis for formulating public policies to promote the equal participation of women in fishing and environmental conservation.

  19. Diversidade Palinológica das Convolvulaceae do Parque Nacional do Catimbau, Buíque, PE, Brasil Pollen diversity of Convolvulaceae at Catimbau National Park, Buíque, Pernambuco State, Brazil

    Directory of Open Access Journals (Sweden)

    Maria Teresa Aureliano Buril Vital

    2008-12-01

    Full Text Available Foram registradas quatorze espécies de Convolvulaceae no Parque Nacional do Catimbau. Com base na morfologia polínica, os táxons foram subdivididos em dois grupos: Psiloconiae - Evolvulus elegans Moric, E. frankenioides Moric, E. glomeratus Choisy, E. linarioides Meisn, Jacquemontia densiflora Hallier, J. montana Meisn, Jacquemontia sp. e Merremia cissoides Hallier, e Echinoconieae - Ipomoea bahiensis Willd., I. brasiliana (Choisy Meissn, I. pintoi O'Donnel, I. rosea Choisy, I. subincana Meisn e Turbina cordata (Choisy Austin & Staples. As espécies de Evolvulus são diferenciadas por diâmetro dos grãos de pólen e espessura da exina. Jacquemontia mostrou dois tipos polínicos - pantocolpado e tricolpado. Em Merremia cissoides, os grãos de pólen são tricolpados e as columelas são ramificadas. Ipomoea e Turbina têm grãos de pólen espinhosos. Entretanto, apenas em Ipomoea os espinhos apresentam base bulbar. Palinologicamente, Convolvulaceae no Parque Nacional do Catimbau é bastante diversificada e com grupos facilmente reconhecidos.Fourteen species of Convolvulaceae from Catimbau National Park were recognized. Based on pollen-grain morphology, the taxons were split into two groups: Psiloconiae - Evolvulus elegans Moric, E. frankenioides Moric, E. glomeratus Choisy, E. linarioides Meisn, J. densiflora Hallier, J. montana Meisn, Jacquemontia sp. and Merremia cissoides Hallier, and Echinoconieae - Ipomoea bahiensis Willd., I. brasiliana (Choisy Meissn, I. rosea Choisy, I. pintoi O'Donnel, I. subincana Meisn, and Turbina cordata (Choisy Austin & Staples. Evolvulus species are distinguished by differences in exine thickness and pollen-grain diameter. Merremia cissoides has tricolpate pollen grains and bifid columellae. The pollen grains of both Ipomoea and Turbina are echinate; however, the spines have a bulbous base only in Ipomoea. This paper confirms the high diversity of pollen morphology in the family.

  20. As traduções de Bates: dois naturalistas no Rio Amazonas Bates's translations: two naturalists in the Amazon River

    Directory of Open Access Journals (Sweden)

    Cristina Carneiro Rodrigues

    2011-12-01

    Full Text Available Neste trabalho analisam-se duas traduções do relato da viagem do naturalista Henry Walter Bates pela Amazônia, uma publicada em 1944 na Coleção Brasiliana feita pelo naturalista Candido de Mello-Leitão, outra editada em 1979 na Coleção Reconquista do Brasil, assinada por Regina Regis Junqueira. O objetivo do artigo é problematizar a demarcação de limites nítidos entre uma ética da diferença e uma ética da igualdade, pois, em ambos os textos, tanto ocorre um movimento no sentido de preservar a alteridade do texto e do autor, quanto no de domesticar o texto. A análise busca também evidenciar que cada tradução, realizada a partir de diferentes projetos editoriais e tradutórios, acaba por suscitar diferentes imagens do naturalista e dos lugares por ele visitados.Two translations of the travel writing by the naturalist Henry Walter Bates in the Amazon are analyzed in this work: one published in 1944 in the Brasiliana Collection by the naturalist Candido de Mello-Leitão, and another edited in 1979 in the Reconquista do Brasil Collection, signed by Regina Regis Junqueira. The purpose of this study is to examine the delimitation of clear boundaries between an ethics of difference and an ethics of equality, since the two texts present a movement that both preserves the otherness of the text and the author and domesticates the text. The analysis also aims to evidence that each translation, carried out from different editorial and translational projects, ultimately projects different images of naturalist and the places visited by him.

  1. Parasites of three commercially exploited bivalve mollusc species of the estuarine region of the Cachoeira river (Ilhéus, Bahia, Brazil).

    Science.gov (United States)

    Boehs, Guisla; Villalba, Antonio; Ceuta, Liliane Oliveira; Luz, Joaldo Rocha

    2010-01-01

    This paper reports the parasites found in three commercially exploited bivalve molluscs (Mytella guyanensis, Anomalocardia brasiliana and Iphigenia brasiliana) of an estuarine region of Ilhéus, south of Bahia, Brazil (14 degrees 48'23''S; 39 degrees 02'47''W). Samples of 20 individuals of each species were collected fortnightly from August 2005 to August 2006. A total of 1480 individuals was collected and processed by standard histologic techniques; the histologic sections were stained with Harris haematoxylin and eosin and examined with light microscope. The water temperature in the study area varied from 24 to 30.5 degrees C and the salinity from 0 to 23ppt. Remarkable differences were found in the parasitic community between the three mollusc species involved in the study, which occupied different habitats in the estuarine region of the Cachoeira river. The following parasites were found: intracellular rickettsia-like colonies in digestive epithelia; intracellular gregarine Nematopsis sp. in gills, mantle, gonad, digestive gland and foot muscle; sporocysts of a Bucephalidae trematode in gonads, mantle, gills, digestive gland and foot; unidentified digenetic metacercariae in digestive gland and gonad; metacestodes of Tylocephalum sp. in connective tissue in the digestive gland and in gonad; and an unidentified metazoan in mantle and intestinal lumen. No significant temporal variation in the prevalence of any parasite was detected, which could be due to the narrow temperature range of the region and the absence of patterns of salinity and rainfall variation through the year. The infestation by sporocyst was the only pathological threat detected for the studied populations because of its potential for host castration. The low infection intensity and/or prevalence of the other parasites and the lack of obvious lesions suggest that there is no other serious pathological risk for the studied mollusc populations.

  2. Digenean parasites of Ciconiiform birds from Argentina Digéneos parásitos de aves Ciconiiformes de Argentina

    Directory of Open Access Journals (Sweden)

    Fabiana B. Drago

    2011-03-01

    Full Text Available The helminthological survey of 13 specimens of 5 ciconiiform species revealed the presence of 10 species of intestinal digeneans: Sphincterodiplostomum musculosum Dubois, 1936 in Tigrisoma lineatum and Ardea alba; Tylodelphys elongata (Lutz, 1928 in T. lineatum; Apharyngostrigea ardearum (Lutz, 1928 and Dolichorchis lacombeensis Lunaschi and Drago, 2006 in Ardea cocoi and Ardea alba; Posthodiplostomum nanum Dubois, 1937 in A. alba and T. lineatum; Ascocotyle diminuta (Stunkard and Haviland, 1924 in A. alba; Petasiger sp.1 in A. cocoi and Paryphostomum segregatum Dietz, 1909, Strigea vaginata (Brandes, 1888 and Petasiger sp. 2 in Coragyps atratus. Syrigma sibilatrix was free of digeneans. The reports of A. ardearum, T. elongata, S. musculosum and D. lacombeensis represent new host records; the other reports are new geographical records. Moreover, the specimens described as Apharyngostrigea brasiliana Szidat, 1929 by Labriola and Suriano (1998 were analyzed and transferred to A. ardearum.El estudio parasitológico de 13 ejemplares pertenecientes a 5 especies de aves Ciconiiformes reveló la presencia de 10 especies de digéneos intestinales: Sphincterodiplostomum musculosum Dubois, 1936 en Tigrisoma lineatum y Ardea alba; Tylodelphys elongata (Lutz, 1928 en T. lineatum; Apharyngostrigea ardearum (Lutz, 1928 y Dolichorchis lacombeensis Lunaschi y Drago, 2006 en Ardea cocoi y A. alba; Posthodiplostomum nanum Dubois, 1937 en A. alba y T. lineatum; Ascocotyle diminuta (Stunkard y Haviland, 1924 en A. alba; Petasiger sp.1 en A. cocoi y Paryphostomum segregatum Dietz, 1909, Strigea vaginata (Brandes, 1888 y Petasiger sp. 2 en Coragyps atratus. Syrigma sibilatrix no se encontró parasitada por digéneos. El presente estudio aporta nuevos registros de hospedadores para A. ardearum, T. elongata, S. musculosum y D. lacombeensis y nuevos registros geográficos para las restantes especies. Además, los organismos descritos como Apharyngostrigea brasiliana

  3. Species occurrence of the potentially toxigenic diatom genus Pseudo-nitzschia and the associated neurotoxin domoic acid in the Argentine Sea.

    Science.gov (United States)

    Almandoz, Gastón O; Fabro, Elena; Ferrario, Martha; Tillmann, Urban; Cembella, Allan; Krock, Bernd

    2017-03-01

    The marine diatom genus Pseudo-nitzschia, the major known producer of the neurotoxin domoic acid (DA) responsible for the amnesic shellfish poisoning (ASP) syndrome in humans and marine mammals, is globally distributed. The genus presents high species richness in the Argentine Sea and DA has been frequently detected in the last few years in plankton and shellfish samples, but the species identity of the producers remains unclear. In the present work, the distribution and abundance of Pseudo-nitzschia species and DA were determined from samples collected on two oceanographic cruises carried out through the Argentine Sea (∼39-47°S) during summer and spring 2013. Phytoplankton composition was analysed by light and electron microscopy while DA was determined by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The genus Pseudo-nitzschia was recorded in 71 and 86% of samples collected in summer and spring, respectively, whereas DA was detected in only 42 and 21% of samples, respectively. Microscopic analyses revealed at least five potentially toxic species (P. australis, P. brasiliana, P. fraudulenta, P. pungens, P. turgidula), plus putatively non-toxigenic P. dolorosa, P. lineola, P. turgiduloides and unidentified specimens of the P. pseudodelicatissima complex. The species P. australis showed the highest correlation with DA occurrence (r=0.55; p<0.05), suggesting its importance as a major DA producer in the Argentine Sea. In the northern area and during summer, DA was associated with the presence of P. brasiliana, a species recorded for the first time in the Argentine Sea. By contrast, high concentrations of P. fraudulenta, P. pungens and P. turgidula did not correspond with DA occurrence. This study represents the first successful attempt to link toxigenicity with Pseudo-nitzschia diversity and cell abundance in field plankton populations in the south-western Atlantic. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Use of fishing resources by women in the Mamanguape River Estuary, Paraíba state, Brazil

    Directory of Open Access Journals (Sweden)

    Michelle S.P. Rocha

    2012-12-01

    Full Text Available We evaluated the appropriation and use of fishing resources by women residing near the Mamanguape River Estuary (MRE, Paraíba state, Brazil. Were used combinations of qualitative (interviews and direct observations and quantitative methods (use value and corrected principal use concordance. Thirty women were interviewed and reported the use of 41 species (30 fish, 8 crustaceans, and 3 mollusks, mainly for local consumption and sale. The species with the highest use value were Genidens genidens (0.7, Callinectes exasperatus (0.73 and Anomalocardia brasiliana (0.46. The diversity of resources exploited demonstrates the importance of the mangrove ecosystem to MRE families, and the data gathered can serve as a basis for formulating public policies to promote the equal participation of women in fishing and environmental conservation.Nós analisamos a apropriação e o uso dos recursos pesqueiros pelas mulheres que moram no Estuário do Rio Mamanguape, Estado da Paraíba, Brasil. Foi usada uma combinação de métodos qualitativos (entrevistas e observações diretas e quantitativos (valor de uso e concordância de uso principal corrigido. Foram entrevistadas 30 mulheres e registrado o uso de 41 espécies (peixes - 30, crustáceos - 08 e moluscos - 03, principalmente para consumo local e venda. As espécies com maior valor de uso foram Genidens genidens (0,7, Callinectes exasperatus (0,73 e Anomalocardia brasiliana (0,46. A diversidade de recursos explorados demonstra a importância do manguezal para as famílias do ERM, e os dados coletados podem servir de base para a formulação de políticas públicas que promovam a participação igualitária de mulheres na pesca, e na conservação ambiental.

  5. Are Entangled Polymer Melts Different From Solutions?

    DEFF Research Database (Denmark)

    Huang, Qian; Mednova, Olga; Rasmussen, Henrik K.

    The possible existence of a qualitative difference on extensional steady state viscosity between polymer melts and polymer solutions is still an open question. Recent experiments [1-4] showed the extensional viscosity of both polymer melts and solutions decayed as a function of strain rate...... with an exponent of -0.5. When the strain rate became higher than the order of inverse Rouse time, the polymer solutions showed an upturn [1, 4]. However, in the same regime for polymer melts, the experiments were contrary: some of the experiments showed an upturn [4, 5], while others did not [2, 3]. In order...... to further investigate the extensional steady state viscosity of polymer melts, we carefully synthesized two monodisperse polystyrenes with molar masses of 248 and 484 kg/mole. The start-up and steady uniaxial elongational viscosity have been measured for the two melts using a filament stretching rheometer...

  6. Guarded Cubical Type Theory

    DEFF Research Database (Denmark)

    Birkedal, Lars; Bizjak, Aleš; Clouston, Ranald

    2016-01-01

    terms. CTT provides a computational interpretation of functional extensionality, enjoys canonicity for the natural numbers type, and is conjectured to support decidable type-checking. Our new type theory, guarded cubical type theory (GCTT), provides a computational interpretation of extensionality......This paper improves the treatment of equality in guarded dependent type theory (GDTT), by combining it with cubical type theory (CTT). GDTT is an extensional type theory with guarded recursive types, which are useful for building models of program logics, and for programming and reasoning...... with coinductive types. We wish to implement GDTT with decidable type checking, while still supporting non-trivial equality proofs that reason about the extensions of guarded recursive constructions. CTT is a variation of Martin-L\\"of type theory in which the identity type is replaced by abstract paths between...

  7. Surface stress-induced change in overall elastic behavior and self-bending of ultrathin cantilever plates

    Science.gov (United States)

    Sadeghian, H.; Goosen, J. F. L.; Bossche, A.; van Keulen, F.

    2009-06-01

    In this letter, the dominant role of surface stress and surface elasticity on the overall elastic behavior of ultrathin cantilever plates is studied. A general framework based on two-dimensional plane-stress analysis is presented. Because of either surface reconstruction or molecular adsorption, there exists a surface stress and a surface elasticity imbalance between top and bottom surface of the cantilever. The surface elasticity imbalance creates an extra bending-extensional coupling which has not been taken into account previously. This leads to a modified extensional stiffness, bending stiffness and bending-extensional coupling stiffness. Due to the surface stress imbalance, an extended Stoney's formula for self-bending of ultrathin cantilevers is derived.

  8. Divulgação

    Directory of Open Access Journals (Sweden)

    Equipe REB Ensino de Bioquímica

    2015-06-01

    Full Text Available A partir do 2015 faremos a divulgação de portais e materiais de ensino na área de Bioquímica, Biologia Molecular, Ciências, Biologia, Química e áreas correlatas.O objetivo é ampliar a divulgação e o acesso aos interessados visando a melhoria e a potencialização dos processos de aprendizagem.Caso tenha interesse em fazer a divulgação de seu material ou portal, escreva para contato@bioquimica.org.br indicando o título, resumo, instituição, responsável. Tempo de Ciências - PodCiência: podcasts de divulgação científicaPortal de divulgação científica por meio de podcasts nas áreas de Biologia e Química, desenvolvido no Instituto de Bioquímica Média Leopoldo de Meiswebsite: http://tempodeciencia.wix.com/site#!podcincia/c11nfFacebook: https://www.facebook.com/tempodeciencia Energia e Matéria - da fundamentação conceitual às aplicações tecnológicasLivro abordando a energia, matéria e suas transformações, abordando a temática de modo multidisciplinar, congregando a Biologia, Física e Química em uma obra que busca a integração dos conhecimentos na busca de novos caminhos para o ensino integrado e contextualizado, saindo da escala micro para a nanoscópica.1a Edição – 2015 – ISBN 9788578613280Carlos Alberto dos Santos (org, professor na Universidade Federal do Rio Grande do Sul B iblioteca Digital de CiênciasPortal que disponibiliza materiais (vídeos, áudios, textos, softwares, roteiros de aulas práticas na área de Biologia/ Ciênciias, Bioquímica e correlatas, desenvolvido no Laboratório de Tecnologias Educacionais (LTE, Instituto de Biologia, Unicamp.website:http://www.bdc.ib.unicamp.br

  9. Environmental variables and the use of habitat of the Red fox Vulpes vulpes (L., 1758 in the Maremma Natural Park, Grosseto province, Central Italy / Parametri ambientali e uso dell'habitat della volpe Vulpes vulpes (L., 1758 in alcune aree del Parco Naturale della Maremma (GR

    Directory of Open Access Journals (Sweden)

    Sandro Lovari

    1991-07-01

    Full Text Available Abstract Berries of Juniperus oxycedrus, beetles and grasshoppers were the staple of the fox diet in the coastal ecotone of the Maremma Natural Park, while fruit and Insects were the main food resources in a rural zone around the park. Chiefly berries of J. oxycedrus, but also Insects and carrion, built up the greater part of the fox diet in the pinewood. On average, the presence in diet was correlated with the availability of the main food resources, which in turn was correlated with climatic factors. These influenced also the activity pattern of the Red fox. Home ranges were the largest (330 ha in the pinewood, intermediate (213 ha in the coastal ecotone, and smallest (131 ha in the rural zone. Such differences in size may be explained with the local pattern of food distribution and abundance, which also influenced the habitat use of the fox. In spite of the presence of several farm houses in the rural range, poultry and domestic rabbits were almost absent in the fox diet. The scrubwood (macchia was consistently the most preferred vegetation type. Riassunto Frutti di ginepro (Juniperus oxycedrus, Coleotteri e Ortotteri hanno costituito la maggior parte della dieta della Volpe nell'ecotone costiero del Parco Naturale della Maremma, mentre frutti e Insetti sono stati le principali risorse trofiche in una zona rurale nella parte esterna del parco. Nella pineta la dieta è risultata costituita prevalentemente da frutti di ginepro, ma anche da insetti e carogne. In media la presenza nella dieta delle principali risorse alimentari è risultata correlata con la loro disponibilità, la quale si è dimostrata a sua volta correlata con fattori climatici. Questi ultimi hanno influenzato anche il ritmo di attività della Volpe. Le dimensioni degli home range sono risultate massime (330 ha nella pineta, intermedie (213 ha nell'ecotone costiero e minime (131 ha nella zona rurale. Queste differenze

  10. As implicações do implante coclear para desenvolvimento das habilidades de linguagem: uma revisão da literatura

    Directory of Open Access Journals (Sweden)

    Anderson Jonas das Neves

    2015-10-01

    Full Text Available Resumo: A reabilitação auditiva por meio do implante coclear tem constituído um campo de atuação e de pesquisa interdisciplinar, cujos interesses têm incidido na investigação das variáveis e processos relacionados às habilidades de linguagem dessa população. O presente estudo teve como objetivo apresentar uma revisão sistemática das pesquisas que investigaram as relações entre o uso do implante coclear e o desenvolvimento da linguagem. Para isso, foi realizada uma busca nas bases científicas Web of Science(r, Scielo(r e LILACS(r, de 2003 a 2013, de estudos sob escopo da Audiologia (e de áreas correlatas, Educação, Reabilitação e Ciências do Comportamento; aplicando os unitermos "cochlear implant", "auditory recognition", "recognition", "speech", "speech production" e "language". Após um tratamento inicial dos resultados, foram selecionados para análise 86 artigos que foram classificados de acordo com os seguintes critérios: ano de publicação, periódico, área de pesquisa, tipo de estudo, habilidade investigada e a temática. Os resultados indicaram crescente avanço nesses estudos e uma ênfase em avaliar e/ou identificar possíveis fatores que interferem nos processos de linguagem de implantados cocleares, sendo essas pesquisas conduzidas majoritariamente pela Audiologia e áreas correlatas. Os estudos comparativos e explicativos foram os mais frequentes e têm destacado as habilidades auditivas, especificamente os fatores que afetam a percepção auditiva. Enquanto perspectivas futuras, poderão ser vislumbrados maior envolvimento científico de áreas interdisciplinares à Audiologia, ampliação de pesquisas sobre habilidades expressivas (como a produção oral e fomento à estudos que investiguem intervenções (práticas baseadas em evidências em linguagem para esse público.

  11. Filament stretching rheometer: inertia compensation revisited

    DEFF Research Database (Denmark)

    Szabo, Peter; McKinley, Gareth H.

    2003-01-01

    The necessary inertia compensation used in the force balance for the filament stretching rheometer is derived for an arbitrary frame of reference. This enables the force balance to be used to extract correctly the extensional viscosity from measurements of the tensile force at either end of the e......The necessary inertia compensation used in the force balance for the filament stretching rheometer is derived for an arbitrary frame of reference. This enables the force balance to be used to extract correctly the extensional viscosity from measurements of the tensile force at either end...

  12. Brand equity management strategies of Spanish press firms through their digital extensions

    OpenAIRE

    Victoria-Mas, María; Iván LACASA-MAS

    2016-01-01

    Las marcas periodísticas encuentran en las plataformas digitales una gran oportunidad de mantener y aumentar el valor que tienen. Solo una minoría de empresas informativas tradicionales ha desarrollado estrategias de gestión de ese valor. Cuando las extensiones digitales no son coherentes con las marcas madre, pueden diluir su imagen y acabar siendo contraproducentes. Este artículo explora hasta qué punto las marcas de prensa utilizan sus extensiones digitales para aumentar su valor y cómo co...

  13. Rheology in Pharmaceutical Sciences

    DEFF Research Database (Denmark)

    Aho, Johanna; Hvidt, Søren; Baldursdottir, Stefania

    2016-01-01

    Rheology is the science of flow and deformation of matter. Particularly gels and non-Newtonian fluids, which exhibit complex flow behavior, are frequently encountered in pharmaceutical engineering and manufacturing, or when dealing with various in vivo fluids. Therefore understanding rheology...... is important, and the ability to use rheological characterization tools is of great importance for any pharmaceutical scientist involved in the field. Flow can be generated by shear or extensional deformations, or a combination of both. This chapter introduces the basics of both shear and extensional rheology...

  14. Proximate composition of marine invertebrates from tropical coastal waters, with emphasis on the relationship between nitrogen and protein contents

    Directory of Open Access Journals (Sweden)

    Graciela S Diniz

    2014-05-01

    Full Text Available The chemical profiles of Desmapsamma anchorata, Hymeniacidon heliophila (Porifera, Bunodosoma caissarum, Renilla muelleri (Cnidaria, Aplysia brasiliana, Eledone massyae, Isognomon bicolor (Mollusca, Echinaster brasiliensis, Echinometra lucunter, Holothuria grisea, Lytechinus variegatus (Echinodermata, and Phallusia nigra (Chordata were determined. Hydrosoluble protein was the most abundant class of substances for all species, except for the ascidian Phallusia nigra, in which the carbohydrate content was higher. The percentages of hydrosoluble protein (dry weight, dw varied widely among the invertebrates, ranging from 5.88% (R. muelleri to 47.6% (Eledone massyae of the dw .The carbohydrate content fluctuated from 1.3% (R. muelleri to 18.4% (Aplysia brasiliana of the dw. For most of the species, lipid was the second most abundant class of substances, varying from 2.8% (R. muelleri to 25.3% (Echinaster brasiliensis of the dw. Wide variations were also found for the invertebrates nitrogen content, with the lowest value recorded in the cnidarian R. muelleri (2.02% of the dw and the highest in the molluscan E. massyae (12.7% of the dw. The phosphorus content of the dw varyed from 0.24% (R. muelleri to 1.16% (E. massyae. The amino acid composition varied largely among the species, but for most of the species glycine, arginine, glutamic acid, and aspartic acid were the most abundant amino acids, with histidine and tyrosine among the less abundant amino acids. The actual content of total protein in the samples was calculated by the sum of amino acid residues, establishing dw values that fluctuated from 11.1% (R. muelleri to 66.7% (E. massyae. The proteinaceous nitrogen content was high in all species, with an average value of 97.3% of the total nitrogen. From data of total amino acid residues and total nitrogen, specific nitrogen-to-protein conversion factors were calculated for each species. The nitrogen-to-protein conversion factors ranged from 5.10 to

  15. Utilização do farelo de conchas de vôngole na adsorção de fósforo e como corretivo da acidez do solo Utilization of ground clam shells in the adsorption of phosphorus and for correction of soil acidity

    Directory of Open Access Journals (Sweden)

    Paola A. V. Lo Monaco

    2012-10-01

    Full Text Available Teve-se o objetivo de, com a realização deste trabalho, obter a curva de neutralização do pH de amostras dos horizontes A e B de um Latossolo Vermelho-Amarelo distrófico, utilizando-se de farelo de conchas de vôngole (Anomalocardia brasiliana; além disso, avaliar a capacidade de adsorção de fósforo, obtendo-se a isoterma de adsorção de melhor ajuste aos dados obtidos. Verificou-se que o farelo de concha de vôngole apresenta potencial para uso como corretivo de acidez do solo e que a dose recomendada para correção do pH do horizonte A do Latossolo Vermelho Amarelo distrófico estudado foi de 2,92 t ha-1, enquanto, para correção do horizonte B, foi de 3,35 t ha-1. O farelo de conchas de vôngole também apresentou alta capacidade de adsorção de fósforo, o que indica possibilidades de sua utilização em sistemas que visem à remoção deste elemento químico de águas residuárias. Os modelos de Langmuir e Freundlich ajustaram-se bem aos dados e podem ser utilizados para representar a isoterma de adsorção de fósforo.The objective of this study was to obtain the curve of pH neutralization for samples of the horizons A and B of a dystrophic Rhodic Haplustox soil using ground clam shells (Anomalocardia brasiliana, as well as assess the capacity of phosphorus adsorption to obtain the adsorption isotherm that best fit to the data obtained. It was found that the ground clam shells present potential to be used in soil acidity correction and that the recommended dose for pH correction of horizon A of the dystrophic Rhodic Haplustox studied was 2.92 t ha-1, while for correction of horizon B was 3.35 t ha-1. The ground clam shells also showed high adsorption capacity for phosphorus, which indicates possibilities of its use in systems targeting the removal of this chemical from wastewater. The Langmuir and Freundlich models fit well to the data and may be used to represent the adsorption isotherm.

  16. “Sensing” il “city model” per incrementare l’efficacia e l’usabilità delle risorse digitali

    Directory of Open Access Journals (Sweden)

    Massimiliano Condotta

    2012-12-01

    Full Text Available L’attuale modo di gestire la conoscenza, basato su sistemi ICT, ha raggiunto un elevato livello prestazionale nel modo di utilizzare e gestire le informazioni degli archivi digitali. Tuttavia, ci sono ancora notevoli potenzialità inespresse nel modo di accedere e di usufruire la conoscenza, soprattutto in ragione delle possibili correlazioni con le informazioni non-digitali. Queste potenzialità sono ancora più rilevanti nel settore dei dati urbani e territoriali per i quali sono a disposizione numerose tecnologie di carattere innovativo che possono essere utilizzate nella gestione delle informazioni relative alla città, soprattutto se orientate alla grande sfida rappresentata dall’implementazione del modello smart cities. Il presente articolo illustra una di queste potenzialità: l’uso dei concetti della tassonomia semiotica per aumentare l’efficacia delle informazioni legate a una rappresentazione digitale della città. L’ambizione di quest’articolo è di stimolare una possibile attività congiunta tra istituzioni e utenti di Internet verso la creazione di una nuova risorsa di conoscenza condivisa, strutturata, semanticamente correlata e basata su un substrato di informazioni che rappresenta, in modo virtuale, l’ambiente fisico reale.

  17. Aquisição de conhecimento para construção de ontologias: uma proposta de roteiro metodológico aplicado ao contexto da hematologia

    Directory of Open Access Journals (Sweden)

    Kátia Cardoso Coelho

    2012-01-01

    Full Text Available Obter conhecimento especializado de um dado domínio do conhecimento é um desafio para diversos campos científicos. Em áreas correlatas às ciências da vida a terminologia é abrangente e complexa sujeita a diferentes interpretações para termos especializados. Esse tipo de problema, dentre outros relacionados, tem sido abordado há anos pela Ciência da Informação. O objetivo geral do presente trabalho é buscar alternativas para minimizar a distância entre o que o especialista tem a oferecer e aquilo que é de fato registrado como o que ele sabe. Para tal, foi proposto um roteiro para elicitação de conhecimento, para obtenção de conhecimento especializado sobre Mielopatia associada ao HTLV I. O universo empírico de dados corresponde à participação de pesquisadores do Grupo de Pesquisa em HTLV – GIPH, bem como a sua produção científica. Uma contribuição evidente da pesquisa é o roteiro metodológico descrito, que possibilitou a obtenção dos principais termos do domínio, candidatos à ontologia.

  18. A classe dos polinômios bivariados de Fibonacci (PBF: elementos recentes sobre a evolução de um modelo.

    Directory of Open Access Journals (Sweden)

    Francisco Regis Vieira Alves

    2017-02-01

    Full Text Available Se constata na abordagem, por parte dos autores de livros de História da Matemática – HM, uma apreciação lacônica, lúdica e desprovida de um vigor histórico-matemático que proporcione ao leitor um entendimento do processo evolutivo irrefreável hodierno do modelo de Fibonacci, originariamente correspondente ao processo biológico de produção de pares de coelhos. A partir dessa perspectiva, o trabalho atual discute a classe dos Polinômios Bivariados Complexos de Fibonacci – PBCF. Os mesmos constituem uma representação generalizada da Sequência de Fibonacci, em termos de uma variável real ‘x’ e a unidade imaginária ‘i’. Assim, o texto aborda e pormenoriza determinados resultados matemáticos que envidam uma perspectiva correlata ao processo ininterrupto evolutivo do modelo de Fibonacci, costumeiramente negligenciados por autores de livros.

  19. Um balanço de parte da teoria dos sistemas intencionais de Dennett

    Directory of Open Access Journals (Sweden)

    Filipe Lazzeri

    Full Text Available Dennett (1981/1987b caracteriza sua abordagem do funcionamento dos termos intencionais (aqueles para as assim chamadas atitudes proposicionais como um "behaviorismo lógico holista", ou versão holista de delineamentos conceituais traçados por Ryle (1949. Este artigo avalia algumas de suas possíveis contribuições e desvantagens para tais delineamentos, e algumas consequências para sua proposta de utilização destes termos em psicologia. Argumenta-se que a abordagem não se mostra mais plausível do que a de seu predecessor, caso a dimensão mentalista que lhe acrescenta seja equivocada, e que de fato este é o caso. Disso resulta que suas contribuições e proposta correlata devem ser entendidas com independência daquilo que tal dimensão implica. Uma alternativa não-mentalista, baseada no modelo selecionista de Skinner, para uma eventual adoção dos termos intencionais em psicologia, é brevemente discutida.

  20. Além do cânon: mão invisível, ordem natural e instituições

    Directory of Open Access Journals (Sweden)

    Antonio Tiago Loureiro Araújo dos Santos

    2007-09-01

    Full Text Available O artigo propõe um entendimento não canônico da mão invisível de Adam Smith, que implicou uma leitura atenta dos textos originais e sua inserção no contexto histórico e intelectual da época. Para atingir esse objetivo, identificamos a conexão entre mão invisível e noções correlatas (ordem natural, conseqüências não intencionais e discutimos o deísmo e o papel das instituições no pensamento de Smith. A discussão é precedida por breve apresentação dos fundamentos comportamentais da teoria smithiana, com a qual procuramos melhor amparar nossas conclusões.The article proposes a non-canonical understanding of Adam Smith´s invisible hand, which implied a careful reading of the original texts and their framing in the historical and intelectual context of their time. To reach this goal, we identify the connection between the invisible hand and correlated notions (natural order, non-intentional consequences and we discuss deism and the role of institutions in Smith´s thought. The discussion is preceded by a brief exposition of the behavioral foundations of the Smithian theory, in which we looked for a better support to our conclusions.

  1. AMPLIFICAÇÃO CRUZADA DE PRIMERS SSR DE CAFEEIRO EM GENÓTIPOS DE ANTÚRIO

    Directory of Open Access Journals (Sweden)

    Edilson Marques Junior

    2017-04-01

    Full Text Available Anthurium andraeanum Lindl. é uma espécie florística, de grande importância na diversificação da agricultura tropical. É a segunda flor tropical no mercado mundial, no entanto há uma dificuldade para a delimitação taxonômica do gênero. Estudos com marcadores moleculares eliminam algumas dificuldades encontradas quando se trabalha com marcadores morfológicos, e dentre as várias classes de marcadores moleculares, os marcadores microssatélites (SSR apresentam interessantes características para a distinção e classificação de indivíduos. Porém, o desenvolvimento de primers específicos para uma espécie requer um longo e oneroso trabalho. Até o momento não existem estudos moleculares de sequenciamento do genoma de antúrios, impossibilitando o desenvolvimento de marcadores moleculares para a espécie A. andraeanum, como o SSR. Considerando que os SSRs encontrados em determinadas espécies podem ser transferidos para espécies correlatas, neste trabalho foram testados 20 primers SSRs desenvolvidos para o cafeeiro em 16 genótipos de antúrio. Dos 20 primers testados, dois apresentaram amplificação para a espécie A. andraeanum, o que corresponde a 10% de taxa de transferência.

  2. Como antecipar os efeitos de uma tecnologia? Um Modelo Exploratório Inspirado na Nova Ciência de McLuhan e Aplicado ao Facebook

    Directory of Open Access Journals (Sweden)

    Vinícius Andrade Pereira

    2015-12-01

    Full Text Available O artigo tem como objetivo principal identificar os principais efeitos dos sites de redes sociais (SRS na cultura contemporânea, tendo como objeto específico o Facebook. Como referência teórica e metodológica adota-se uma proposição exploratória fortemente inspirada em uma “Nova Ciência”, tal como aventada por McLuhan. Isso implica a Lei dos Meios, sintetizada nas Tétrades. Como resultados o estudo propõe um conjunto de efeitos do Facebook na cultura contemporânea, que já podem ser identificados e mapeados e que se constituem como novos pontos e questões para futuras pesquisas. Ainda, apresenta um método de pesquisa que propõe o diálogo com disciplinas correlatas ao campo da comunicação, assim como uma metodologia flexível, capaz de lidar com descrições em profundidade de um objeto, ao mesmo tempo que acolher acasos e desvios de um procedimento científico ortodoxo, tal como preconizado por Feyerabend. Por fim, o estudo recupera uma parte importante da obra de McLuhan, ainda pouco explorada nos estudos comunacionais no Brasil.

  3. Economia e Planejamento do Ecoturismo: Estudo de Caso no Cerrado Brasileiro

    Directory of Open Access Journals (Sweden)

    Maione Rocha de Castro Cardoso

    2015-12-01

    Full Text Available É inegável que o turismo é hoje uma das principais atividades econômicas, porém seu desenvolvimento enseja diversos impactos nas comunidades locais (positivos e negativos. Com efeito, apresenta-se o Ecoturismo como alternativa sustentável de desenvolvimento do turismo e das atividades correlatas. O objetivo do trabalho é analisar a política e a gestão do Ecoturismo no município de Pirenópolis/GO e seus reflexos sobre a economia local. Para isso, foram utilizadas pesquisa bibliográfica e documental, entrevistas semiestruturadas e, em caráter complementar, observações e notas obtidas nas visitas de campo. Como resultado, pode-se dizer que a política e a gestão do Ecoturismo na área estudada mostraram-se em um estado muito inicial, atualmente, com poucas ações em operação dentre aquelas previstas no Plano Municipal de Turismo. Constatou-se, também, haver necessidade de uma estratégia de divulgação mais sistematizada dos eventos e atrativos locais nos meios de comunicação mais democráticos (TV e rádio e via internet, como forma de atrair mais visitantes e incrementar a geração de renda na região.

  4. ICMS SOBRE COMÉRCIO ELETRÔNICO. A INCONSTITUCIONALIDADE DO ICMS SOBRE COMPRAS ELETRÔNICAS POR CONSUMIDOR FINAL DE MERCADORIAS PROVENIENTES DE OUTROS ESTADOS, E QUESTÕES PROCESSUAIS CONEXAS. ANÁLISE À LUZ DOS DECRETOS 12.534, DE 2010, E 12.831, DE 2011, D

    Directory of Open Access Journals (Sweden)

    André Portella

    2015-06-01

    Full Text Available Trata-se de estudo que objetiva a análise de medidas legislativas adotadas por Estados da Federação no tocante ao regime de incidência do ICMS sobre as compras realizadas por consumidor final, tudo à luz da Constituição Federal de 1988. De maneira mais precisa, a análise tem como foco operações interestaduais com mercadorias e serviços destinadas a consumidor final. São consideradas as razões para a adoção de tais medidas pelos Estados, os fundamentos constitucionais que lhes dariam respaldo, os instrumentos legislativos utilizados para implementá-las, sempre à vista dos primados constitucionais tributários da legalidade, isonomia, não-discriminação em função da origem ou destino da mercadoria ou serviço, vedação à limitação tributária ao tráfego, e não-bitributação. De maneira correlata, são finalmente consideradas as medidas judiciais passíveis de adoção.

  5. O dedo em baioneta e o uso de drogas ilícitas

    Directory of Open Access Journals (Sweden)

    Borini Paulo

    2001-01-01

    Full Text Available A prevalência do "dedo em baioneta", sinal semiológico do distúrbio de déficit de atenção e hiperatividade (DHDA, foi determinada em pacientes do sexo masculino usuários de drogas ilícitas, internados em hospital psiquiátrico. Grupo controle, pareado quanto ao sexo, idade e classe social, foi selecionado da população geral. O sinal foi observado em 165/345 (47,8% dos usuários de drogas e 13/50 (26% dos controles, a diferença sendo estatisticamente significativa. Os portadores da anormalidade têm risco estimado de 2,61, risco relativo de 1,84 e probabilidade de 92,7% de usarem drogas ilícitas. As observações sugerem que, para homens: (1 o DHDA e síndromes correlatas estariam presentes em aproximadamente metade dos casos de usuários de drogas ilícitas e representariam fator de vulnerabilidade para o uso de tais drogas; (2 indivíduos portadores de "dedo em baioneta", especialmente adolescentes, deveriam merecer especial atenção para prevenção de uso de drogas.

  6. Modelos de equações estruturais em psicologia: conceitos e aplicações

    Directory of Open Access Journals (Sweden)

    Ronaldo Pilati

    Full Text Available O debate sobre procedimentos e técnicas de tratamento de dados é relevante para o contexto de produção e avanço do conhecimento em várias áreas do saber. Os Modelos de Equações Estruturais são um conjunto de técnicas de tratamento de dados que têm recebido grande atenção de pesquisadores, especialmente nos últimos 10 anos. Esse procedimento de tratamento de dados possui suas raízes relacionadas a distintas áreas do conhecimento: a biometria, a econometria e a psicometria. Como conseqüência de suas peculiaridades, o relato científico em Modelos de Equações Estruturais deve considerar vários aspectos relevantes, como a definição teórica do modelo a ser testado, a especificação e identificação do modelo, além de aspectos de estimação e mensuração dos índices de adequação. Vários desses elementos são apresentados e discutidos no presente artigo focando-se nas possibilidades de aplicação na Psicologia e em ciências correlatas. Perspectivas futuras e limitações dos Modelos de Equações Estruturais são discutidas.

  7. Estado emocional de alunos da primeira série de um Grupo Escolar - Ginásio da cidade de São Paulo, Brasil: problemática de saúde pública?

    Directory of Open Access Journals (Sweden)

    Helena Savastano

    1977-12-01

    Full Text Available Estudou-se uma amostra representativa de alunos da 1.ª série de um Grupo Escolar-Ginásio da rede estadual da cidade de São Paulo, com o objetivo de compreender a dinâmica emocional dessas crianças. Os alunos foram estratificados em fracos e não fracos quanto à aprendizagem e disciplinamento. Utilizou-se o teste de apercepção temática de Bellak e Bellak e os resultados demonstraram, que 43% das crianças não estão emocionalmente ajustadas para enfrentar o ambiente escolar, onde a figura do adulto (professor é visualizada como agressiva e os castigos são vistos, pelas crianças, como ameaçadores; os alunos fracos revelaram maior atraso no desenvolvimento psicossocial em relação aos não fracos. Estes dados, possivelmente, esclarecem parte das dificuldades de adaptação dessas crianças à situação escolar e sugerem: 1º maior atenção dos técnicos de educação, de saúde e áreas correlatas, para esses problemas; 2º maiores conhecimentos pelos educadores, dos aspectos do desenvolvimento psicossocial da criança.

  8. Democratic equality and respect

    Directory of Open Access Journals (Sweden)

    Baynes, Kenneth

    2008-01-01

    Full Text Available O artigo procura mostrar que a idéia liberal de assegurar uma igual liberdade para todos deve ser reexaminada em dois âmbitos de discussões acerca de um desejável equilibrio entre liberdade e igualdade, de forma a evitar a separação tanto da liberdade e da igualdade como dos domínios opondo reivindicações formais e substantivas. Estas devem antes ser consideradas em suas condições correlatas, exigidas para um exercício democrático efetivo da autonomia privada e pública dos cidadãos, como foi sugerido por Habermas. O artigo mostra que a questão da igualdade de condição não pode evitar as dificeis questões suscitadas pelo chamado debate sobre a "diferença" e tentavidas de ir "além da igualdade e da diferença" e tentavidas de ir "além da igualdade e da diferença "ou de "reconstituir" um ideal de igual cidadania numa democracia. Deve lidar com aspectos levantados em discussões sobre a igualdade de condição e o respeito

  9. Numerical simulation of breakup and detachment of an axially ...

    Indian Academy of Sciences (India)

    The extensional, breakup and detachment dynamics of an axially stretching Newtonian liquid bridge are investigated numerically with a dynamic domain multiphase incompressible flow solver. The multiphase flow solver employs a Cahn–Hilliard phase field model to describe the evolution of the diffuse interfaceseparating ...

  10. Long-term coupling and feedbacks between surface processes and tectonics during rifting

    Science.gov (United States)

    Theunissen, Thomas; Huismans, Ritske S.

    2017-04-01

    Whereas significant efforts have been made to understand the relationship between mountain building and surfaces processes, limited research has been done on the relationship between surface processes and extensional tectonics. Here we present high-resolution 2-D coupled tectonic-surface processes modeling of extensional basin formation. The main aim is to find out how erosion and deposition affect the deformation in extensional systems. We test the combined effects of crustal rheology and varying surface process efficiency (erodibility, sea level) on structural style of rift and passive margin formation. The results show that both erosion of rift flank areas and basin deposition enhance localization of crustal deformation. Frictional-plastic extensional shear zones accumulate more deformation during a longer period of time, and loading of offshore basins can generate crustal ductile flow. In extreme cases sediment deposition delays lithospheric rupture. These mechanisms are enhanced when fluvial erosion, transport and deposition are efficient. We show that removal of mass from rift flanks and sedimentary loading in the basin area provide a first order feedback with tectonic deformation and control on rifted margin tectonic-morphology. However, surface processes do not change the first order structural style of rifting, which is largely controlled by crustal rheology. Rift escarpment morphology is function of paleo-topography and sea level. Variation of strain localization in natural rift systems correlates with the observed behavior and suggests similar feedbacks as demonstrated by the forward numerical models.

  11. Comparison of observed rheological properties of hard wheat flour dough with predictions of the Giesekus-Leonov, White-Metzner and Phan-Thien Tanner models

    Science.gov (United States)

    Dhanasekharan, M.; Huang, H.; Kokini, J. L.; Janes, H. W. (Principal Investigator)

    1999-01-01

    The measured rheological behavior of hard wheat flour dough was predicted using three nonlinear differential viscoelastic models. The Phan-Thien Tanner model gave good zero shear viscosity prediction, but overpredicted the shear viscosity at higher shear rates and the transient and extensional properties. The Giesekus-Leonov model gave similar predictions to the Phan-Thien Tanner model, but the extensional viscosity prediction showed extension thickening. Using high values of the mobility factor, extension thinning behavior was observed but the predictions were not satisfactory. The White-Metzner model gave good predictions of the steady shear viscosity and the first normal stress coefficient but it was unable to predict the uniaxial extensional viscosity as it exhibited asymptotic behavior in the tested extensional rates. It also predicted the transient shear properties with moderate accuracy in the transient phase, but very well at higher times, compared to the Phan-Thien Tanner model and the Giesekus-Leonov model. None of the models predicted all observed data consistently well. Overall the White-Metzner model appeared to make the best predictions of all the observed data.

  12. Leibnizian intensional semantics for syllogistic reasoning

    NARCIS (Netherlands)

    van Rooij, R.; Ciuni, R.; Wansing, H.; Willkommen, C.

    2014-01-01

    Venn diagrams are standardly used to give a semantics for Syllogistic reasoning. This interpretation is extensional. Leibniz, however, preferred an intensional interpretation, according to which a singular and universal sentence is true iff the (meaning of) the predicate is contained in the (meaning

  13. Extension induced phase separation and crystallization in semidilute solutions of ultra high molecular weight polyethylene

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; Imperiali, Luna; Stepanyan, Roman

    2018-01-01

    Abstract We investigate the influence of controlled uniaxial extension on various flow induced phenomena in semidilute solutions of ultra high molecular weight polyethylene (UHMwPE). Concentrations range from 9 w% to 29 w% and the choice of solvent is paraffin oil (PO). The start-up extensional...

  14. Constraints on deformation of the Southern Andes since the Cretaceous from anisotropy of magnetic susceptibility

    NARCIS (Netherlands)

    Maffione, Marco; Hernandez-Moreno, Catalina; Ghiglione, Matias C.; Speranza, Fabio; van Hinsbergen, Douwe J.J.; Lodolo, Emanuele

    2015-01-01

    The southernmost segment of the Andean Cordillera underwent a complex deformation history characterized by alternation of contractional, extensional, and strike-slip tectonics. Key elements of southern Andean deformation that remain poorly constrained, include the origin of the orogenic bend known

  15. Elastic properties of nonstoichiometric reacted PDMS networks

    DEFF Research Database (Denmark)

    Skov, Anne Ladegaard; Hansen, Kristoffer Karsten; Sommer-Larsen, Peter

    2003-01-01

    The influence of stoichiometry on the elastic modulus of eight-functional end-linked poly(dimethylsiloxane) (PDMS) networks was investigated by extensional rheometry with extensions up to more than 100%, and the stress-strain relation was found to be almost linear-a characteristic property...

  16. Polymeric liquids in extension: fluid mechanics or rheometry?

    DEFF Research Database (Denmark)

    Hassager, Ole; Marin, Jose Martin Roman; Yu, Kaijia

    2010-01-01

    We use a transient 3D free surface finite element method to simulate flow of entangled polymer fluids in the dual cylinder wind-up extensional rheometer. The constitutive equations are K-BKZ integral representations of the Doi-Edwards models with and without the independent alignment approximation...

  17. Layered crust-mantle transition zone below a large crustal intrusion in the Norwegian-Danish basin

    DEFF Research Database (Denmark)

    Sandrin, Alessandro; Nielsen, Lars; Thybo, Hans

    2009-01-01

    crust-mantle transition zone as solidified melts of mantle affinity, which were intruded into the lowermost crust. The layered zone is proposed to be associated with the extensional tectonism that occurred in the area in Late Carboniferous-Early Permian, which also caused the large crustal intrusion...

  18. Determination of Mechanical Properties of Microcapsules

    NARCIS (Netherlands)

    Sagis, L.M.C.

    2015-01-01

    Mechanical characterization methods can be important tools in optimizing the design of an encapsulation system. Food microcapsules can be subjected to considerable shear and extensional forces during their life cycle, and the shell of the capsules needs to be designed with sufficient mechanical

  19. Neoproterozoic tectonics of the Arabian-Nubian Shield

    NARCIS (Netherlands)

    Blasband, B.

    2006-01-01

    The Neoproterozoic tectonic development of the Arabian-Nubian Shield (ANS) can be divided in three parts: 1) the oceanic stage; 2) the arc-accretion stage; 3) the extensional stage. Three key-areas in the Arabian-Nubian Shield, namely the Bi'r Umq Complex, The Tabalah and Tarj Complex and the Wadi

  20. Algebraic Optimization of Recursive Database Queries

    DEFF Research Database (Denmark)

    Hansen, Michael Reichhardt

    1988-01-01

    a generalization of Aho and Ullman, (1979). The result is interpreted in function free logic database terms as a transformation of the recursively defined predicate involving: (a) elimination of an argument, and (b) propagation of selections (instantiations) to the extensionally defined predicates. A collection...

  1. Linear viscoelastic characterization from filament stretching rheometry

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; Alvarez, Nicolas J.; Hassager, Ole

    viscoelasticity well into the nonlinear regime. Therefore at present, complete rheological characterization of a material requires two apparatuses: a shear and an extensional rheometer. This work is focused on developing a linear viscoelastic protocol for the filament stretching rheometer (FSR) in order...

  2. Opening a Can of Worm(‐like Micelle)s: The Effect of Temperature of Solutions of Functionalized Dipeptides

    Science.gov (United States)

    Draper, Emily R.; Su, Hao; Brasnett, Christopher; Poole, Robert J.; Rogers, Sarah; Cui, Honggang; Seddon, Annela

    2017-01-01

    Abstract A simple heat/cool cycle can be used to significantly affect the properties of a solution of a low‐molecular‐weight gelator at high pH. The viscosity and extensional viscosity are increased markedly, leading to materials with very different properties than when the native solution is used. PMID:28653804

  3. Predictive permeability model of faults in crystalline rocks ...

    Indian Academy of Sciences (India)

    This gives a proportional relationship for JH approximately 1:4:2 between the fault core, inner damage zone, and outer damage zone of extensional fault zones in crystalline rocks. The results of the verification exercise revealed that the new approach would be efficient and that the JH parameter is a reliable scale for the ...

  4. Representations of Sound in American Deaf Literature

    Science.gov (United States)

    Rosen, Russell S.

    2007-01-01

    Sound plays a prominent role in narrative description of characters and environs in mainstream American literature. A review of American Deaf literature shows that the representations of sound held for deaf writers are in extensional and oppositional terms. American deaf writers, in their descriptions of entities, characters, functions, and…

  5. Geodynamic evolution of the Pan-African lower crust in Sri Lanka : structural and petrological investigations into a high-grade gneiss terrain

    NARCIS (Netherlands)

    Kriegsman, L.

    1993-01-01

    Some main objectives of present-day geological research are to assess the role of the lower crust in collision and extensional tectonics and to unravel the mechanism and timing of crustal growth. Both objectives require input from the study of high-grade gneiss terrains, notably data concerning

  6. Long chain branching of PLA

    Science.gov (United States)

    Gu, Liangliang; Xu, Yuewen; Fahnhorst, Grant; Macosko, Christopher W.

    2017-05-01

    A trifunctional aziridine linker, trimethylolpropane tris(2-methyl-1-aziridinepropionate) (TTMAP), was melt blended with linear polylactic acid (PLA) to make star branched PLA. Adding pyromellitic dianhydride (PMDA) led to long chain branched (LCB) PLA. Mixing torque evolution during melt processing revealed high reactivity of aziridine with the carboxyl end group on PLA and an incomplete reaction of PMDA with the hydroxyl end group. Star-shaped PLA exhibited higher viscosity but no strain hardening in extensional flow while LCB PLA showed significant extensional hardening. Excess TTMAP in the branching reaction resulted in gel formation, which led to failure at low strain in extension. PMDA conversion was estimated based on gelation theory. The strain rate dependence of extensional hardening indicated that the LCB PLA had a low concentration of long chain branched molecules with an H-shaped topology. Unlike current methods used to branch PLA, free radical chemistry or use of an epoxy functional oligomers, our branching strategy produced strain hardening with less increase in shear viscosity. This study provides guidelines for design of polymers with low shear viscosity, which reduces pressure drop in extrusion, combined with strong extensional hardening, which enhances performance in processes that involve melt stretching.

  7. Controllability of Non-Newtonian Fluids Under Homogeneous Flows

    National Research Council Canada - National Science Library

    Wilson, Lynda M

    2007-01-01

    .... The constitutive models are as follows: the Phan-Thien-Tanner model; the Johnson-Segalman model; and the Doi model. The effect of extensional flow on these models and the effect of shear flow on the Doi model have not been explored previous to this work...

  8. The Mesozoic Tectonic Dynamics and Chronology in the Eastern North China Block

    Directory of Open Access Journals (Sweden)

    Quanlin Hou

    2012-01-01

    Full Text Available Mesozoic tectonic events in different areas of the eastern North China Block (NCB show consistency in tectonic time and genesis. The Triassic collision between NCB and Yangtze results in the nearly S-N strong compression in the Dabie, Jiaodong, and west Shandong areas in Middle Triassic-Middle Jurassic. Compression in the Yanshan area in the north part of NCB was mainly affected by the collision between Mongolia Block and NCB, as well as Siberia Block and North China-Mongolia Block in Late Triassic-Late Jurassic. However, in the eastern NCB, compressive tectonic system in Early Mesozoic was inversed into extensional tectonic system in Late Mesozoic. The extension in Late Mesozoic at upper crust mainly exhibits as extensional detachment faults and metamorphic core complex (MCC. The deformation age of extensional detachment faults is peaking at 120–110 Ma in Yanshan area and at 130–110 Ma in the Dabie area. In the Jiaodong area eastern to the Tan-Lu faults, the compression thrust had been continuing to Late Mesozoic at least in upper crust related to the sinistral strike slipping of the Tan-Lu fault zone.The extensional detachments in the eastern NCB would be caused by strong crust-mantle action with upwelling mantle in Late Mesozoic.

  9. Continentward-dipping detachment fault system and asymmetric rift structure of the Baiyun Sag, northern South China Sea

    Science.gov (United States)

    Zhou, Zhichao; Mei, Lianfu; Liu, Jun; Zheng, Jinyun; Chen, Liang; Hao, Shihao

    2018-02-01

    The rift architecture and deep crustal structure of the distal margin at the mid-northern margin of the South China Sea have been previously investigated by using deep seismic reflection profiles. However, one fundamental recurring problem in the debate is the extensional fault system and rift structure of the hyperextended rift basins (Baiyun Sag and Liwan Sag) within the distal margin because of the limited amount of seismic data. Based on new 3D seismic survey data and 2D seismic reflection profiles, we observe an array of fault blocks in the Baiyun Sag, which were tilted towards the ocean by extensional faulting. The extensional faults consistently dip towards the continent. Beneath the tilted fault blocks and extensional faults, a low-angle, high-amplitude and continuous reflection has been interpreted as the master detachment surface that controls the extension process. During rifting, the continentward-dipping normal faults evolved in a sequence from south to north, generating the asymmetric rift structure of the Baiyun Sag. The Baiyun Sag is separated from the oceanic domain by a series of structural highs that were uplifted by magmatic activity in response to the continental breakup at 33 Ma and a ridge jump to the south at 26-24 Ma. Therefore, we propose that magmatism played a significant role in the continental extension and final breakup in the South China Sea.

  10. sedimentology, depositional environments and basin evolution

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT: The Inter-Trappean coal and oil shale-bearing sedimentation in the Delbi-Moye Basin took place in tectonically controlled grabens and half-grabens formed by extensional fault systems and accompanied by passive subsidence. The sedimentation history of the basin is related to the tectonic events that affected ...

  11. in vitro production of virus free sweet potato [ipomoea batatas (l

    African Journals Online (AJOL)

    preferred customer

    latitudinal extension direction in the Quaternary deduced from fault slip analysis and earthquake focal mechanism .... similarly oriented extensional fault systems, and associated accom- modation structures. They have orientations consistent with that of the regional stress (ca. ...... origin, propagation and architecture of faults.

  12. Framing Effects Are Robust to Linguistic Disambiguation: A Critical Test of Contemporary Theory

    Science.gov (United States)

    Chick, Christina F.; Reyna, Valerie F.; Corbin, Jonathan C.

    2016-01-01

    Theoretical accounts of risky choice framing effects assume that decision makers interpret framing options as extensionally equivalent, such that if 600 lives are at stake, saving 200 implies that 400 die. However, many scholars have argued that framing effects are caused, instead, by filling in pragmatically implied information. This linguistic…

  13. An Axiomatic Theory for Partial Functions

    NARCIS (Netherlands)

    Kuper, Jan

    We describe an axiomatic theory for the concept of one-place, partial function, where function is taken in its extensional sense. The theory is rather general; i.e., concepts such as natural number and set are definable, and topics such as non-strictness and self application can be handled. It

  14. Sedimentology, depositional environments and basin evolution of ...

    African Journals Online (AJOL)

    The Inter-Trappean coal and oil shale-bearing sedimentation in the Delbi-Moye Basin took place in tectonically controlled grabens and half-grabens formed by extensional fault systems and accompanied by passive subsidence. The sedimentation history of the basin is related to the tectonic events that affected East Africa.

  15. An insight into asymmetric back-arc extension: Tecto-magmatic evidences from the Ulleung Basin, the East Sea (Sea of Japan)

    Science.gov (United States)

    Kim, Gi Bom; Yoon, Seok-Hoon

    2017-10-01

    This paper presents an ancient example of asymmetric back-arc extension found in the Ulleung Basin, the southwestern East Sea (Sea of Japan). The paper focuses on the formative processes of variable asymmetric features of the basin and on their relationship to the style of lithospheric stretching. In the Ulleung Basin, features resulting from asymmetric back-arc extension include: 1) the syn-extensional volcanism concentrated to the northern flank of the basin, 2) the overwhelming number of north-dipping syn-extensional normal faults, 3) the style of boundary faults different between the northern and southern conjugate margins, and 4) the thickness of the crust and the depth to the Moho discontinuity that together decrease toward north. We argue that the fundamental control of such asymmetric features was the simple-shear-style lithospheric extension, which presumably involved a crustal detachment, the mid-crustal extension of north-dipping syn-extensional listric normal faults. By the simple-shear-style extension, syn-extensional faults evolved to dip toward north, and at the same time volcanic activities that had been initially widespread throughout the basin became to concentrate to the north of the basin. The northward deviantion of volcanic centers and the zone underlain by maximally attenuated crust (possibly the extinct spreading center) might be the result of separation between the loci of basin subsidence and asthenospheric upwelling that is common in simple-shear cases.

  16. Reaction texture and Fe-Mg zoning in granulite garnet from ...

    Indian Academy of Sciences (India)

    The latter is associated with a Pan-African tectono-metamorphic event that has been interpreted to represent a continent-continent collision followed by extensional collapse. Reaction-diffusion modeling of the compositional zoning of garnet associated with the development of reaction texture during M2 yields a time scale of ...

  17. PML:PAGE-OM Markup Language: About PAGE-OM [

    Lifescience Database Archive (English)

    Full Text Available he Object Management Group (OMG) standardization organization, and this was approved in 2006. The latest meet...ing to continue this model development was held in Tokyo in September 2007. The meeting discussed extension...ation as well as modeling experimental results for associations between genotype and phenotype. The outcome of that meet

  18. Effect of planar extension on the structure and mechanical properties of polystyrene-poly(ethylene-¤co¤-butylene)-polystyrene triblock copolymers

    DEFF Research Database (Denmark)

    Daniel, C.; Hamley, I.W.; Mortensen, K.

    2000-01-01

    Two thermoplastic poly(styrene)-poly(ethylene-co-butylene) -poly(styrene) triblock copolymers containing either spherical or cylindrical poly(styrene) microdomains were pre-oriented through extensional flow. Small angle neutron scattering (SANS) measurements revealed that the pre-oriented triblock...

  19. Stress relaxation of entangled polystyrene solution after constant-rate, uniaxial elongation

    DEFF Research Database (Denmark)

    Matsumiya, Yumi; Masubuchi, Yuichi; Watanabe, Hiroshi

    For an entangled solution of linear polystyrene (PS 545k; M = 545k) in dibutyl phthalate (DBP), the stress relaxation after constant-rate uniaxial elongation was examined with an extensional viscosity fixture mounted on ARES (TA Instruments). The PS concentration, c = 52 wt%, was chosen in a way...

  20. Late Cretaceous evolution of the northern Sistan suture zone ...

    Indian Academy of Sciences (India)

    and kinematic environments, particularly trans- pressive and extensional regime, such as in ..... pressional and dextral strike-slip movement at least in the later episodes of intrusion, when ... Possible kinematics at the eastern boundary of the Sistan suture zone; (c) for a slip vector perpendicular to the boundary and pure ...

  1. Back-arc extension in the Andaman Sea: Tectonic and magmatic processes imaged by high-precision teleseismic double-difference earthquake relocation

    Digital Repository Service at National Institute of Oceanography (India)

    Diehl, T.; Waldhauser, F.; Cochran, J. R.; KameshRaju, K.A.; Seeber, L.; Schaff, D.; Engdahl, E.R.

    in 1984, 2006, and 2009. Short-term spreading rates estimated from extensional moment tensors account for less than 10 percent of the long-term 3.0-3.8 cm/yr spreading rate, indicating that spreading by intrusion and the formation of new crust make up...

  2. La usurpación de tierras comunales y baldíos en Guadalajara durante la segunda mitad del siglo XV

    OpenAIRE

    Plaza de Agustín, Javier

    2015-01-01

    La ciudad de Guadalajara, desde su incorporación a la corona castellana, se constituyó como cabeza de un amplio territorio de realengo sobre el que ejercía su jurisdicción. Este alfoz se componía de considerables extensiones de tierras de uso comu

  3. Transverse Mode Multi-Resonant Single Crystal Transducer

    Science.gov (United States)

    Snook, Kevin A. (Inventor); Liang, Yu (Inventor); Luo, Jun (Inventor); Hackenberger, Wesley S. (Inventor); Sahul, Raffi (Inventor)

    2015-01-01

    A transducer is disclosed that includes a multiply resonant composite, the composite having a resonator bar of a piezoelectric single crystal configured in a d(sub 32) transverse length-extensional resonance mode having a crystallographic orientation set such that the thickness axis is in the (110) family and resonance direction is the (001) family.

  4. Untitled

    Indian Academy of Sciences (India)

    bending, torsion and extensional loads. Uniform symmetric and antisymmetric layup beams were built for several cases. Measured bending slope and twist distributions were correlated satisfactorily (Chandra et al 1990; Smith & Chopra 1991). These beams were also tested for their rotating vibration characteristics in the 10- ...

  5. Rheological characterization of modified foodstuffs with food grade thickening agents

    Science.gov (United States)

    Reyes-Ocampo, I.; Aguayo-Vallejo, JP; Ascanio, G.; Córdova-Aguilar, MS

    2017-01-01

    This work describes a rheological characterization in terms of shear and extensional properties of whole milk, modified with food grade thickening agents (xanthan and carboxymethyl cellulose) with the purpose of being utilized in dysphagia treatment. Shear viscosity of the thickened fluids (2% wt. of xanthan and CMC) were measured in a stress-controlled rheometer and for extensional viscosity, a custom-built orifice flowmeter was used, with elongation rates from 20 to 3000 s-1. Such elongation-rate values represent the entire swallowing process, including the pharyngeal and esophageal phases. The steady-state shear and extensional flow curves were compared with the flow curve of a pudding consistency BaSO4 suspension (α=05), typically used as a reference fluid for the specialized commercial dysphagia products. The modified fluids presented non-Newtonian behavior in both, shear and extensional flows, and the comparison with the reference fluid show that the thickened milk prepared here, can be safely used for consumption by patients with severe dysphagia.

  6. Chapter 2. Borderlands environment, past and present

    Science.gov (United States)

    Guadalupe Sanchez de Carpenter; A.C. MacWilliams

    2006-01-01

    The major mountain ranges in the study area today were produced by Middle Miocene and younger extensional faulting. Faulting continued into the late Pleistocene as evidenced by fault scarps along the margins of the Animas, Hachita, and Playas Valleys. These long-term geologic events resulted in the present basin and range physiography of the Malpai Borderlands, as...

  7. Advanced Query Formulation in Deductive Databases.

    Science.gov (United States)

    Niemi, Timo; Jarvelin, Kalervo

    1992-01-01

    Discusses deductive databases and database management systems (DBMS) and introduces a framework for advanced query formulation for end users. Recursive processing is described, a sample extensional database is presented, query types are explained, and criteria for advanced query formulation from the end user's viewpoint are examined. (31…

  8. Evaluation of microwave and ultrasound extraction procedures for arsenic speciation in bivalve mollusks by liquid chromatography–inductively coupled plasma-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Clarissa M.M.; Nunes, Matheus A.G. [Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Barbosa, Isa S.; Santos, Gabriel L. [Instituto de Química, Universidade Federal da Bahia, Salvador, BA (Brazil); Peso-Aguiar, Marlene C. [Instituto de Biologia, Universidade Federal da Bahia, Salvador, BA (Brazil); Korn, Maria G.A. [Instituto de Química, Universidade Federal da Bahia, Salvador, BA (Brazil); Flores, Erico M.M. [Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Dressler, Valderi L., E-mail: vdressler@gmail.com [Departamento de Química, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2013-08-01

    Liquid chromatography–inductively coupled plasma-mass spectrometry (LC–ICP-MS) was used for arsenic speciation analysis in tissues of bivalve mollusks (Anomalocardia brasiliana sp. and Macoma constricta sp.). Microwave and ultrasound radiation, combined with different extraction conditions (solvent, sample amount, time, and temperature), were evaluated for As-species extraction from the mollusks' tissues. Accuracy, extraction efficiency, and the stability of As species were evaluated by analyzing certified reference materials (DORM-2, dogfish muscle; BCR-627, tuna fish tissue; and SRM 1566b, oyster tissue) and analyte recovery tests. The best conditions were found to be microwave-assisted extraction using 200 mg of samples and water at 80 °C for 6 min. The agreement of As-species concentration in samples ranged from 97% to 102%. Arsenobetaine (AsB) was the main species present in bivalve mollusk tissues, while monomethylarsonic acid (MMA) and arsenate (As(V)) were below the limit of quantification (0.001 and 0.003 μg g{sup −1}, respectively). Two unidentified As species also were detected and quantified. The sum of the As-species concentration was in agreement (90 to 104%), with the total As content determined by ICP-MS after sample digestion. - Highlights: • Method development for As speciation analysis by LC–ICP-MS • Evaluation of microwave and ultrasonic radiation for sample preparation • Investigation on As species content in mollusks.

  9. Evaluation of microwave and ultrasound extraction procedures for arsenic speciation in bivalve mollusks by liquid chromatography-inductively coupled plasma-mass spectrometry

    Science.gov (United States)

    Santos, Clarissa M. M.; Nunes, Matheus A. G.; Barbosa, Isa S.; Santos, Gabriel L.; Peso-Aguiar, Marlene C.; Korn, Maria G. A.; Flores, Erico M. M.; Dressler, Valderi L.

    2013-08-01

    Liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) was used for arsenic speciation analysis in tissues of bivalve mollusks (Anomalocardia brasiliana sp. and Macoma constricta sp.). Microwave and ultrasound radiation, combined with different extraction conditions (solvent, sample amount, time, and temperature), were evaluated for As-species extraction from the mollusks' tissues. Accuracy, extraction efficiency, and the stability of As species were evaluated by analyzing certified reference materials (DORM-2, dogfish muscle; BCR-627, tuna fish tissue; and SRM 1566b, oyster tissue) and analyte recovery tests. The best conditions were found to be microwave-assisted extraction using 200 mg of samples and water at 80 °C for 6 min. The agreement of As-species concentration in samples ranged from 97% to 102%. Arsenobetaine (AsB) was the main species present in bivalve mollusk tissues, while monomethylarsonic acid (MMA) and arsenate (As(V)) were below the limit of quantification (0.001 and 0.003 μg g- 1, respectively). Two unidentified As species also were detected and quantified. The sum of the As-species concentration was in agreement (90 to 104%), with the total As content determined by ICP-MS after sample digestion.

  10. COMPOSIÇÃO CENTESIMAL E DE MINERAIS DE MARISCOS CRUS E COZIDOS DA CIDADE DE NATAL/RN

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    PEDROSA Lucia de Fátima Campos

    2001-01-01

    Full Text Available Este estudo teve como objetivo analisar a composição centesimal e os teores de zinco, cobre e ferro de cinco tipos de mariscos crus e cozidos: Camarão (Penaeus brasiliensis, Caranguejo (Ucides cordatus, Lagosta (Panulirus argus, Ostra (Crassostrea rhizophorae e Mexilhão (Anomalocardia brasiliana, crus e cozidos, provenientes da cidade de Natal/RN. As amostras da parte comestível de cada alimento foram adquiridas em peixaria do cais do porto. Os mariscos foram considerados fontes expressivas de proteínas e minerais, enquanto as quantidades de lipídeos e calorias foram baixas. Observou-se na maioria das amostras teores de proteínas e de cinzas aumentados após a cocção. A concentração de zinco foi variada, apresentando-se a ostra como a maior fonte dentre as espécies estudadas. Os maiores teores de ferro e cobre foram verificados no mexilhão e na ostra. A cocção provocou perdas de 50% de cobre no mexilhão e praticamente não alterou as concentrações do referido nutriente no caranguejo. Esperamos que estes resultados contribuam para bancos de dados que auxiliarão na melhor estimativa de consumo de nutrientes em inquéritos dietéticos.

  11. Plants of restricted use indicated by three cultures in Brazil (Caboclo-river dweller, Indian and Quilombola).

    Science.gov (United States)

    Rodrigues, Eliana

    2007-05-04

    A detailed record of plants cited during ethnopharmacological surveys, suspected of being toxic or of triggering adverse reactions, may be an auxiliary means to pharmacovigilance of phytomedicines, in that it provides greater knowledge of a "bad side" to plant resources in the Brazilian flora. This study describes 57 plant species of restricted use (abortive, contraceptive, contraindicated for pregnancy, prescribed in lesser doses for children and the elderly, to easy delivery, in addition to poisons to humans and animals) as indicated during ethnopharmacological surveys carried out among three cultures in Brazil (Caboclos-river dwellers, inhabitants of the Amazon forest; the Quilombolas, from the pantanal wetlands; the Krahô Indians, living in the cerrado savannahs). These groups of humans possess notions, to a remarkable extent, of the toxicity, contraindications, and interaction among plants. A bibliographical survey in the Pubmed, Web of Science and Dr. Duke's Phytochemical and Ethnobotanical Databases has shown that 5 out of the 57 species have some toxic properties described up to the present time, they are: Anacardium occidentale L. (Anacardiaceae), Brosimum gaudichaudii Trécul (Moraceae), Senna alata (L.) Roxb. (Fabaceae), Senna occidentalis (L.) Link (Fabaceae), Strychnos pseudoquina A. St.-Hil. (Loganiaceae) and Vernonia brasiliana (L.) Druce (Asteraceae).

  12. Systematics of the Neotropical caddisfly genus Notidobiella Schmid (Trichoptera, Sericostomatidae, with the description of 3 new species

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    Ralph Holzenthal

    2010-12-01

    Full Text Available Three new species of Notidobiella Schmid (Insecta: Trichoptera are described from South America: Notidobiella amazoniana sp. n. (Brazil, N. brasiliana sp. n. (Brazil, and N. ecuadorensis sp. n. (Ecuador. In addition, the 3 previously described species in the genus, N. chacayana Schmid, N. inermis Flint, and N. parallelipipeda Schmid, all endemic to southern Chile, are redescribed and illustrated, including the females of each species for the first time, and a key to males of the species in the genus is provided. The ccurrence of Notidobiella in Brazil and Ecuador represents a significant extension of the range of thegenus beyond southern Chile where it was previously thought to be endemic. The biogeography of Sericostomatidae and other austral South American Trichoptera is reviewed. The occurrence of the family in South America may not be part of a “transantarctic” exchange, but instead represent an earlier dispersal to the region. The distribution of Notidobiella in tropical South America likely represents recent dispersal from southern South America to the north.

  13. Detection of Perkinsus marinus in the oyster Crassostrea rhizophorae in southern Bahia by proteomic analysis

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    Thiago Ramos Pinto

    2017-01-01

    Full Text Available This study reports the presence of the pathogen Perkinsus marinus, notifiable to the World Organization for Animal Health (Office International des Èpizooties = OIE in the oyster Crassostrea rhizophorae in southern Bahia via proteomic analysis. We analyzed Crassostrea brasiliana from a long-line cultivation system and C. rhizophorae from an adjacent mangrove in Porto do Campo, Camamu Bay, Bahia, Brazil. The collections (n = 100 were performed in October 2012. In the laboratory, the oysters were measured and opened to remove the meat, which was steeped in dry ice. For extraction of proteins, adaptation of a protocol used for mussels was used, after which separation in the first dimension was taken by isoelectric focusing (IEF. The peptides were transferred to a Mass Spectrometer. The obtained spectra were analyzed with the ProteinLynx Global Server 4.2 software tool and also by MASCOT (Matrix Science and compared to the databases of the SWISSPROT and NCBI, respectively. The identification was evidenced by beta-tubulin, Perkinsus marinus ATCC 50983 and protein homology code in the database NCBI = gi | 294889481. This is the first record of P. marinus in Bahia and the fourth in Brazil.

  14. Persistência de plantas medicinais em sistemas agroflorestais no município de São Bento do Sul, SC, Brasil

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    A.L. Hanisch

    2013-01-01

    Full Text Available No final da década de 90, a comunidade de Rio Natal, no município de São Bento do Sul, SC, passou a fazer parte de uma Área de Preservação Ambiental e desde então, muitas áreas de cultivo, paulatinamente, estão retomando o processo de formação florestal. Neste cenário, foi sugerido pela comunidade, a possibilidade de cultivo de plantas medicinais adaptadas às condições de sombreamento. Em atendimento a essa demanda foi realizada uma pesquisa participativa na comunidade, de 2005 a 2008, onde foram avaliadas 14 espécies de plantas medicinais com potencial de mercado, cultivadas em áreas sombreadas, em três propriedades familiares. Foram avaliados: taxa de sobrevivência das espécies, incidência de doenças e pragas, teor de massa seca e altura das plantas. Apresentaram persistência ao cultivo em áreas sombreadas as espécies: Curcuma longa L. (açafrão-da-índia; Arctium lappa L. (bardana; Pfaffia glomerata (Spreng Pedersen (fáfia ou ginseng-brasileiro; Mikania glomerata Sprengel (guaco; Alternanthera brasiliana L. Kuntze (penicilina; Pogostemon cablin (Blanco Benth (patchuli e Maytenus ilicifolia Mart. Ex Reissek (espinheira-santa.

  15. A critical examination of the possible application of zinc stable isotope ratios in bivalve mollusks and suspended particulate matter to trace zinc pollution in a tropical estuary.

    Science.gov (United States)

    Araújo, Daniel; Machado, Wilson; Weiss, Dominik; Mulholland, Daniel S; Boaventura, Geraldo R; Viers, Jerome; Garnier, Jeremie; Dantas, Elton L; Babinski, Marly

    2017-07-01

    The application of zinc (Zn) isotopes in bivalve tissues to identify zinc sources in estuaries was critically assessed. We determined the zinc isotope composition of mollusks (Crassostrea brasiliana and Perna perna) and suspended particulate matter (SPM) in a tropical estuary (Sepetiba Bay, Brazil) historically impacted by metallurgical activities. The zinc isotope systematics of the SPM was in line with mixing of zinc derived from fluvial material and from metallurgical activities. In contrast, source mixing alone cannot account for the isotope ratios observed in the bivalves, which are significantly lighter in the contaminated metallurgical zone (δ 66 Zn JMC  = +0.49 ± 0.06‰, 2σ, n = 3) compared to sampling locations outside (δ 66 Zn JMC  = +0.83 ± 0.10‰, 2σ, n = 22). This observation suggests that additional factors such as speciation, bioavailability and bioaccumulation pathways (via solution or particulate matter) influence the zinc isotope composition of bivalves. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Metabolomics as a potential chemotaxonomical tool: application in the genus Vernonia schreb.

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    Maria Elvira Poleti Martucci

    Full Text Available The taxonomic classification of the genus Vernonia Schreb is complex and, as yet, unclear. We here report the use of untargeted metabolomics approaches, followed by multivariate analyses methods and a phytochemical characterization of ten Vernonia species. Metabolic fingerprints were obtained by accurate mass measurements and used to determine the phytochemical similarities and differences between species through multivariate analyses approaches. Principal component analysis based on the relative levels of 528 metabolites, indicated that the ten species could be clustered into four groups. Thereby, V. polyanthes was the only species with presence of flavones chrysoeriol-7-O-glycuronyl, acacetin-7-O-glycuronyl and sesquiterpenes lactones piptocarphin A and piptocarphin B, while glaucolide A was detected in both V. brasiliana and V. polyanthes, separating these species from the two other species of the Vernonanthura group. Species from the Lessingianthus group were unique in showing a positive response in the foam test, suggesting the presence of saponins, which could be confirmed by metabolite annotation. V. rufogrisea showed a great variety of sesquiterpene lactones, placing this species into a separate group. Species within the Chrysolaena group were unique in accumulating clovamide. Our results of LC-MS-based profiling combined with multivariate analyses suggest that metabolomics approaches, such as untargeted LC-MS, may be potentially used as a large-scale chemotaxonomical tool, in addition to classical morphological and cytotaxonomical approaches, in order to facilitate taxonomical classifications.

  17. Metabolomics as a potential chemotaxonomical tool: application in the genus Vernonia schreb.

    Science.gov (United States)

    Martucci, Maria Elvira Poleti; De Vos, Ric C H; Carollo, Carlos Alexandre; Gobbo-Neto, Leonardo

    2014-01-01

    The taxonomic classification of the genus Vernonia Schreb is complex and, as yet, unclear. We here report the use of untargeted metabolomics approaches, followed by multivariate analyses methods and a phytochemical characterization of ten Vernonia species. Metabolic fingerprints were obtained by accurate mass measurements and used to determine the phytochemical similarities and differences between species through multivariate analyses approaches. Principal component analysis based on the relative levels of 528 metabolites, indicated that the ten species could be clustered into four groups. Thereby, V. polyanthes was the only species with presence of flavones chrysoeriol-7-O-glycuronyl, acacetin-7-O-glycuronyl and sesquiterpenes lactones piptocarphin A and piptocarphin B, while glaucolide A was detected in both V. brasiliana and V. polyanthes, separating these species from the two other species of the Vernonanthura group. Species from the Lessingianthus group were unique in showing a positive response in the foam test, suggesting the presence of saponins, which could be confirmed by metabolite annotation. V. rufogrisea showed a great variety of sesquiterpene lactones, placing this species into a separate group. Species within the Chrysolaena group were unique in accumulating clovamide. Our results of LC-MS-based profiling combined with multivariate analyses suggest that metabolomics approaches, such as untargeted LC-MS, may be potentially used as a large-scale chemotaxonomical tool, in addition to classical morphological and cytotaxonomical approaches, in order to facilitate taxonomical classifications.

  18. Comanagement of clams in Brazil: a framework to advance comparison

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    Ligia M. Rocha

    2015-03-01

    Full Text Available In Brazil, the recognition that fisheries encompass both natural ecosystems and human well-being has increased, but initiatives are focused largely on highly-valued species, ignoring socially relevant resources such as Venus clams (Anomalocardia brasiliana. We investigate two initiatives involving comanagement of Venus clams in the past two decades: the Marine Extractive Reserve "Pirajubaé" and the "People of the Tides" project. We focus on the nature of the institutional arrangements, the involved groups (fishing communities and government, and the resource, as well as the steps involved in developing the partnerships, identifying which factors favor success in comanagement. Through these projects, fisherwomen got visibility and clam harvesters became the center of institutional developments. However, their rights in management will not become meaningful unless comanagement in protected areas is fully implemented, and government becomes more willing to share power in harvest planning, and to improve health, infrastructure, and the return of value to fisher families. Only then would such cooperation promote sustainability for Venus clams and fisher families.

  19. Desafios à cogestão: os impactos da Via Expressa Sul sobre o extrativismo na RESEX Marinha do Pirajubaé

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    Juliana Lima Spínola

    2014-12-01

    Full Text Available This article focuses on the case of the environmental impacts generated by the installation of the Southern Expressway, an enterprise of the State Government of Santa Catarina, on the extraction of berbigão (cockles; Anomalocardia brasiliana in the Marine Extractive Reserve (RESEX, in the Portuguese acronym Pirajubaé, in Florianópolis (SC. The project caused significant impacts on the marine environment of this RESEX, including the loss of about half of the cockle bank, and hence on extractive practices and their management. The socio-environmental changes resulting from the construction of the Southern Expressway led to a situation of deregulation in the use of fisheries resources, resulting in use conflicts and establishing a situation of open access to resources in the area. In the case of Pirajubaé, when interests of dominant social groups in conflict with the goals of the RESEX were imposed, its institutional arrangement proved unable to secure the rights of the local users or gatherers on the use of natural resources in its territory, which should be the main objective of this kind of Conservation Unit. This leads us to question the effectiveness of the RESEX as an institutional arrangement to ensure shared management and conservation of natural resources in a given territory.

  20. Selection of shrimp breeders free of white spot syndrome and infectious hypodermal and hematopoietic necrosis

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    Carlos Cesar de Mello Junior

    2011-05-01

    Full Text Available The objective of this work was to select surviving breeders of Litopenaeus vannamei from white spot syndrome virus (WSSV outbreak, adapted to local climatic conditions and negatively diagnosed for WSSV and infectious hypodermal and hematopoietic necrosis virus (IHHNV, and to evaluate if this strategy is a viable alternative for production in Santa Catarina, Brazil. A total of 800 males and 800 females were phenotypically selected in a farm pond. Nested-PCR analyses of 487 sexually mature females and 231 sexually mature males showed that 63% of the females and 55% of the males were infected with IHHNV. Animals free of IHHNV were tested for WSSV, and those considered double negative were used for breeding. The post-larvae produced were stocked in nine nursery tanks for analysis. From the 45 samples, with 50 post-larvae each, only two were positive for IHHNV and none for WSSV. Batches of larvae diagnosed free of virus by nested-PCR were sent to six farms. A comparative analysis was carried out in growth ponds, between local post-larvae and post-larvae from Northeast Brazil. Crabs (Chasmagnathus granulata, blue crabs (Callinectes sapidus, and sea hares (Aplysia brasiliana, which are possible vectors of these viruses, were also evaluated. The mean survival was 55% for local post-larvae against 23.4% for post-larvae from the Northeast. Sea hares showed prevalence of 50% and crabs of 67% of WSSV.

  1. Tre vignette: dal cambiamento dell’altro al cambiamento del sé dell’operatore

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    Orietta Sponchiado

    2013-12-01

    Full Text Available Il testo mira a far sui movimenti di cambiamento del sé in una relazione psicoterapeutica, in cui il cliente appartiene ad una cultura differente. Verranno illustrati i passaggi fondamentali del lavoro clinico svolto con una donna brasiliana, la cui richiesta d’aiuto esplicita era relativa la sintomatologia del figlio di 5 anni, ma che dopo una consulenza alla coppia genitoriale mista cambia in una domanda di uno spazio di riflessione individuale rispetto alla storia familiare e migratoria. Si decide di lavorare insieme, concordando obiettivi e procedendo per cicli che affrontassero le seguenti tematiche: ricostruire la sua storia, a partire dalla famiglia d’origine; ricostruire il suo processo migratorio, dal Brasile verso l’Italia; lavorare sul tema dell’identità di bambina, donna, moglie e madre. Durante la relazione si evidenzieranno gli snodi critici di ciascuno di questi tre cicli dentro un processo di elaborazione delle sofferenze, che permette di dare significati differenti agli eventi dolorosi, ma soprattutto di aprirli ed esplorarli in una relazione di affidamento autentica. Si esplorerà questa relazione terapeutica, a sua volta interculturale, illustrando le difficoltà, il processo e i cambiamenti dell’operatrice nel vivere con gli occhi dell’Altra (la cliente la realtà dell’essere straniera.

  2. New Limonoids from Hortia oreadica and Unexpected Coumarin from H. superba Using Chromatography over Cleaning Sephadex with Sodium Hypochlorite

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    Vanessa G.P. Severino

    2014-08-01

    Full Text Available Previous investigations of H. oreadica reported the presence of a wide spectrum of complex limonoids and dihydrocinnamic acids. Our interest in the Rutaceae motivated a reinvestigation of H. oreadica, H. brasiliana and H. superba searching for other secondary metabolites present in substantial amounts for taxonomic analysis. In a continuation of the investigation of the H. oreadica, three new limonoids have now been isolated 9α-hydroxyhortiolide A, 11β-hydroxyhortiolide C and 1(S*-acetoxy-7(R*-hydroxy-7-deoxoinchangin. All the isolated compounds from the Hortia species reinforce its position in the Rutaceae. With regard to limonoids the genus produces highly specialized compounds, whose structural variations do not occur in any other member of the Rutaceae, thus, it is evident from limonoid data that Hortia takes an isolated position within the family. In addition, H. superba afforded the unexpected coumarin 5-chloro-8-methoxy-psoralen, which may not be a genuine natural product. Solid-state cross-polarisation/magic-angle-spinning 13C nuclear magnetic resonance, X-Ray fluorescence and Field-emission gun scanning electron microscopy experiments show that the Sephadex LH-20 was modified after treatment with NaOCl, suggesting that when xanthotoxin (8-methoxy-psoralen was extracted from cleaning of the gel column, chlorination of the aromatic system occurred.

  3. Kelimpahan dan komposisi fitoplankton di perairan Teluk Kodek Pemenang Lombok Utara

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    Nunik Cokrowati

    2014-09-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui kelimpahan dan komposisi fitoplankton di Teluk Kodek Pemenang Lombok Utara. Penelitian ini menggunakan metode survey pada 4 stasiun di perairan Teluk Kodek pada Bulan Agustus 2012 dan analisa fitoplankton dilakukan di Laboratorium Perikanan Program Studi Budidaya Perairan Universitas Mataram. Hasil penelitian menunjukkan bahwa kelimpahan fitoplankton di perairan Teluk Kodek pada bulan Agustus 2012 adalah 6557 ind/l. Tercatat 20 spesies fitoplankton yang ditemukan yang dikelompokkan menjadi dua kelompok besar yaitu diatom dan dinoflagelata. Kelompok diatom terdiri 11 spesies, yaitu; Guinardia flaccida, Rhizosolenia setigera, Navicula sp., Chaetoceros sp., Thalassionema nitzschioides, Pleurosigma normanii, Planktoniella sol, Pseudo-nitzchia brasiliana, Lauderia annulata, Socphanopysis palmeriana, Oscillatoria sp., sedangkan dari kelompok dinoflagelata terdiri dari 9 spesies, yaitu; Pyrocytis noutiluca, Dinophysis cudate., Prorocentrum lima, Alexandrium tamarence, Ceratium fusus, C. incisum, C. boehmii, Torodium teredo and Odontella sinensis. Indeks keragaman phytoplankton Teluk Kodek adalah 0,1307 dan masuk kategori keanekaragaman rendah, sedangkan indek keseragaman diperoleh nilai 0,207 dan masuk kategori keseragaman rendah. Nilai tersebut menunjukkan bahwa komunitas fitoplankton di perairan Teluk Kodek pada Bulan Agustus 2012 tidak stabil.

  4. Pliocene onset of widespread normal faulting in the southern Puna Plateau, southern central Andes, NW Argentina

    Science.gov (United States)

    Montero Lopez, M. C.; Hongn, F. D.; Marrett, R.; Seggiaro, R.; Strecker, M. R.

    2009-12-01

    Normal faults are often observed in many compressional Cenozoic mountain belts and paleotectonic settings and have been associated with a late-stage development in orogen evolution. Often, such normal faults are found in high-elevation sectors in the orogen interior and may form graben, closely spaced arrays or they are kinematically linked with strike-slip faults. In contrast, at lower elevations and in the adjacent foreland regions coeval shortening may be sustained. This situation typifies the active tectonics of the southern central Andes of NW Argentina characterized by the Puna Plateau (22° to 27° S lat), the world’s second largest orogenic plateau with an average elevation of 3.7 km and the adjacent Andean foreland. The Puna contains neotectonic landforms that host widespread active normal faults, closely associated with mafic centres. In contrast, the shortening continued in the foreland. The onset of the extensional kinematic in the Puna has been inferred to be Quaternary in age as many mafic volcanic manifestations were generated during the ultimate 2 Ma. However, our new structural observations and Ar/Ar dating of volcanic deposits and dykes suggests that widespread extension in the Puna started much earlier. We are able to show that the southern margin of the Puna is characterized by extensional structures at different length scales, including extensional fractures, sometimes hosting dykes, as well as normal fault arrays that cut volcanic edifices and flows, visible on satellite imagery. Fault kinematic analysis and an assessment of dyke and fracture orientations documents that the region at about 27°S lat is affected by N-S extension. This must be a regional phenomenon as similar observations can be made in areas farther north as well. Our geochronology work on lava flows and dykes in this region suggests that an extensional regime may have been in existence by 7-6 Ma and extensional processes were well underway by 4 Ma. The often observed

  5. Structural architecture and paleofluid evolution of the Compione fault, Northern Apennines

    Science.gov (United States)

    Lucca, Alessio; Storti, Fabrizio; Balsamo, Fabrizio; Molli, Giancarlo

    2016-04-01

    The Compione fault (CF) is part of the basin boundary East Lunigiana extensional fault system, active since Early Pliocene. This system is composed of three main fault segments, striking almost NW-SE and dipping 60-70° to the SW. The offset of the CF exceeds 1 km and caused the tectonic juxtaposition of turbiditic sandstones of the Late Oligocene-Early Miocene Macigno Fm. in the footwall, against the calcareous pelites, siltites and fine sandstones of the Ottone Fm. (a Late Cretaceous Ligurian Helminthoid Flysch) in the hangingwall. The CF overprints the previously-formed contractional tectonic stack where the Ottone Fm. overthrusted the Macigno Fm. during Miocene times. We performed a detailed structural analysis along a cross-section perpendicular to the CF in its central part, coupled with laboratory analyses including standard and cold cathodoluminescence petrography, microtermometric and stable isotope analysis of vein cements, and particle size analysis of fault core rocks. Field data show that the architecture of the CF is formed by an about 1.5 km wide asymmetric damage domain, composed of an up to 1 km wide footwall damage zone, an almost 500 m wide hangingwall damage zone and a core domain with variable thickness, up to some tens of meters, mostly composed of cataclastic sandstones and gouge layers, which typically incorporates one or more shear lenses of Macigno sandstones. In the footwall, extensional deformation affecting very thick and coarse sandstone strata caused intense fracturing, mostly by low-displacement conjugate extensional faulting. Hangingwall rocks are less fractured than footwall rocks due to their different composition and rheology, which favoured abundant dissolution-cementation processes and extensional faulting along less numerous, higher displacement shear zones. We propose an evolutionary model of the CF that starts with upward propagation as a blind extensional fault dissecting the previously formed thrust-related anticline

  6. Study of the interactions between poly(ethylene oxide) and anionic surfactants in elongational flow

    Science.gov (United States)

    Smitter, Luis Manuel

    2001-07-01

    The rheology of polymer solutions is important in a wide variety of applications. In particular, solutions of high-molecular-weight, flexible polymers exhibit an increase in their apparent extensional viscosity with strain rate under extensional flow conditions. This extension thickening is due to formation of transient entanglements of polymer molecules. Certain commercial fluids contain both polymers and surfactants that might interact at the molecular level. These interactions affect the conformation of the polymer chain and, therefore, the rheological behavior of the solution. For instance, addition of anionic surfactants to solutions of nonionic polymers is known to induce increases in the shear viscosity of aqueous solution. This work investigates the behavior of aqueous solutions of a high-molecular-weight poly(ethylene oxide) (PEO), a nonionic, flexible polymer, and the anionic surfactants sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS) and a commercial alpha-olefin sulfonate (AOS) in extensional flows. The extensional rheology of polymer/surfactant solutions is studied in an opposed-jets device, which generates a flow field close to uniaxial extension. For PEO/SDS mixtures, the results show that formation of micellar aggregates of SDS along the PEO chains results in an increase in the strength of extension thickening of PEO solutions by promoting intermolecular interactions between polymer chains. The minimum PEO concentration required to form intermolecular entanglements is substantially reduced in the presence of micellar aggregates. In solutions containing NaCl, intramolecular interactions are observed at low PEO concentrations. These reduce the strength of extension thickening. Addition of a co-solvent is investigated. The presence of alcohols in the aqueous solutions affects their rheology by changing the solvent nature for both PEO and SDS. In particular, n-octanol promotes aggregation of SDS along the PEO chains, enhancing

  7. Characterizing the Eastern Galicia Magnetic Anomaly (NW Spain): Origin of the mineralization and implications on the age of the Central Iberian Arc

    Science.gov (United States)

    Ayarza, Puy; Ramón Martínez Catalán, Jose; José Villalaín, Juan; Alvarez Lobato, Fernando; Durán Oreja, Manuela; de Prada Galende, Carmen

    2017-04-01

    The EGMA (Eastern Galicia Magnetic Anomaly) is the most conspicuous anomaly of the Central Iberian Arc. It coincides with the Lugo-Sanabria extensional dome, a structure developed during the final stages of Variscan deformation in the NW Iberian Massif, where important crustal thickening triggered overheating and extension of the crust. In fact, every extensional dome at the Central Iberian Arc is also coincident with a, less intense but equally important, magnetic anomaly. The bend featured by these anomalies is one of key attributes of the aforementioned arc. As yet, models of the EGMA, all based on low resolution aeromagnetic data, have not established a relationship between magnetization and tectonics. Ayarza and Martínez Catalán (2007) suggested that the source of the EGMA were syntectonic igneous rocks outcropping at the northern Lugo-Sanabria dome, but did not inferred any process as source of the mineralization. A high resolution (2x2 km) magnetic land survey carried out recently at the northern part of the dome has shed some light on this issue. The new magnetic anomaly map shows that the maxima coincide with identified extensional detachments and not with the center of the dome. These structures are often related to migmatites and inhomogeneous granites produced by crustal melting during the thermal event that triggered the extension. However, detachments also affect metasediments that, in these areas, show high magnetic susceptibilities. 2D models also indicate that the magnetization is concentrated along detachments and AMS studies show a planar anisotropy coincident with that of these extensional structures. Finally, rockmag studies indicate that multi-domain magnetite is the main magnetic mineral. A younger, probably Cretaceous, remanence has been addressed to hematite. These results constrain the models about the origin of the EGMA and probably that of the rest of anomalies defining the Central Iberian Arc. We suggest they developed during thermal

  8. Age and Origin of the Eastern Galicia Magnetic Anomaly (NW Spain): Constraints on the Understanding of the Central Iberian Arc

    Science.gov (United States)

    Ayarza, P.; Martinez-Catalan, J. R.; Villalain, J. J.; Alvarez Lobato, F.; Durán-Oreja, M.; Joven Romero, P.

    2016-12-01

    The EGMA (Eastern Galicia Magnetic Anomaly) is the most intense anomaly of the Iberian Massif. It overlaps the Lugo-Sanabria extensional dome, suggesting a link with it. However, models of the anomaly, all based on low resolution aeromagnetic data, do not establish a relationship between magnetization and tectonics. Surprisingly, a closer look into this dataset shows that magnetic anomalies defining the Central-Iberian Arc bend also coincide with extensional gneiss domes. In this regard, Ayarza and Martínez Catalán (2007) suggested that the source of the EGMA were migmatites and inhomogeneous granites outcropping in the northern Lugo dome, but did not inferred any process as source of the anomaly. In 2015-16, a high resolution (2x2 km) magnetic land survey over a 750 km2 area was carried out in the N of the Lugo dome. In addition, magnetic rocks were sampled in order to characterize their mineralogy and anisotropy of the magnetic susceptibily (AMS).The resulting map shows that the anomaly maxima coincide with outcropping extensional detachments. These structures are related to igneous rocks produced by crustal melting during the thermal event that triggered the extension. However, detachments also affect metasediments that, in these areas, show high magnetic susceptibilities. Similarly, 2D models indicate that the magnetization is concentrated on these detachments and AMS exhibits planar anisotropy coincident with that of the extensional structures. Finally, rockmag studies indicate that multi-domain magnetite is the main magnetic mineral although a younger remanence has been addressed to hematite. These results constrain the models about the origin of the EGMA and the rest of the anomalies defining the Central Iberian Arc. We suggest that the former was developed during thermal and extensional events (E1 and E2: 330-300 Ma) that followed crustal thickening during the Variscan collision in present NW Iberia. These events developed thermal gneiss domes and

  9. Origin of the Eastern Galicia Magnetic Anomaly (NW Spain). Implications for the Origin of Magnetic Anomalies in the Central Iberian Arc

    Science.gov (United States)

    Ayarza, P.; Martinez-Catalan, J. R.; Villalain, J. J.; Alvarez Lobato, F.; Martin Paramio, M.; Rodriguez Gómez, S.; Sanz López, M.

    2015-12-01

    The aeromagnetic map of Iberia features outstanding anomalies that have been key to define the Central Iberian Arc, a late-orogenic orocline in the western part of the Variscan belt. The most studied of them is the EGMA (Eastern Galicia Magnetic Anomaly), which follows the Lugo-Sanabria extensional dome and is probably associated with it. Among the existing models of this anomaly, those relating it with magnetite-rich inhomogeneous granites and migmatites formed during late-Variscan extension seem to be more plausible ones. However, this and other interpretations involving deep-seated mafic/ultramafic bodies lack resolution as they are based on the aeromagnetic dataset. New ground magnetic data have been acquired in the northern part of the Xistral Tectonic Window, at the core of the Lugo dome where its deepest rocks crop out. The resulting maps show that the anomaly ranges ~1000 nT (vs. 190 nT on the aeromagnetic map) and that the most important maxima lie on top of extensional detachments located on high-grade metasediments or inhomogeneous granites. 2D forward modeling indicates that the magnetization is carried by upper Neoproterozoic and early Cambrian metasediments, partially melted during late-Variscan high-T and low-P metamorphic event linked to the extensional collapse. Furthermore, the anomaly maxima are spatially related with detachments, where the metasediments were strongly sheared. Therefore, the P-T, redox and fluid pressure conditions necessary for the formation of magnetite seem related with the extensional process and the dynamics of its structures. Many magnetic anomalies of the Central Iberian Arc lie on top of Variscan extensional domes and accordingly may have a similar origin. Special attention is paid to the Gredos Magnetic Anomaly, coincident with the batholith of the same name. Preliminary magnetic mapping and modeling indicate that the anomaly is previous to the intrusion of the Jurassic Alentejo-Plasencia dyke and to the tardi

  10. Pseudomonas aeruginosa multiresistente em unidade de cuidados intensivos: desafios que procedem? Pseudomonas aeruginosa multiresistente en una unidad de cuidados intensivos: desafíos que proceden? Multi-resistant pseudomonas aeruginosa among patients from an intensive care unit: persistent challenge?

    Directory of Open Access Journals (Sweden)

    Maria Verônica Guilherme Ferrareze

    2007-03-01

    Full Text Available OBJETIVOS: Avaliar a ocorrência de infecção hospitalar por Pseudomonas aeruginosa multiresistente em pacientes hospitalizados em uma unidade de cuidados intensivos. MÉTODO: estudo retrospectivo realizado de outubro de 2003 a setembro de 2004 em um hospital de emergências. RESULTADOS: Totalizou-se 68 portadores de bactérias multiresistentes sendo 10 (14,7% de P. aeruginosa. Destes, 8 pacientes eram do sexo masculino, as médias de idade e de internação foram respectivamente de 57 anos a média de idade, 43,7 a média de dias de internação e 7 pacientes morreram. Isolaram-se 8 cepas no sangue, cinco na urina, duas em cateteres venosos e uma no líquor, das quais sete sensíveis somente a polimixina e três ao imipenem. CONCLUSÃO: O perfil microbiológico deve ser avaliado periodicamente visto que é específico de uma unidade ou instituição, e demanda ações correlatas.OBJETIVOS: Evaluar la ocurrencia de infección hospitalaria por Pseudomonas aeruginosa multiresistente en pacientes hospitalizados en una unidad de cuidados intensivos. MÉTODO: estudio retrospectivo realizado de octubre del 2003 a setiembre del 2004 en un hospital de emergencias. RESULTADOS: Se tuvo un total de 68 portadores de bacterias multiresistentes de las cuales 10 (14,7% de P. aeruginosa. De éstos, 8 pacientes eran del sexo masculino, los promedios de edad y de internamiento fueron respectivamente de 57 años y 43,7 de días de internamiento y 7 pacientes murieron. Se aislaron 8 cepas en la sangre, cinco en la orina, dos en catéteres venosos y una en el licor, de ellas siete eran sensibles sólo a la polimixina y tres al imipenem. CONCLUSIÓN: El perfil microbiológico debe ser evaluado periódicamente dado que es específico de una unidad o institución, y demanda acciones correlatas.OBJECTIVES: To evaluate the occurrence of multi-resistant Pseudomonas Aeruginosa infection among patients from an Intensive Care Unit. METHODS: This retrospective study was

  11. Dike-induced contraction along oceanic and continental divergent plate boundaries

    KAUST Repository

    Trippanera, D.

    2014-10-28

    The axis of divergent plate boundaries shows extension fractures and normal faults at the surface. Here we present evidence of contraction along the axis of the oceanic ridge of Iceland and the continental Main Ethiopian Rift. Contraction is found at the base of the tilted hanging wall of dilational normal faults, balancing part of their extension. Our experiments suggest that these structures result from dike emplacement. Multiple dike injection induces subsidence above and uplift to the sides of the dikes; the transition in between is accommodated by reverse faults and subsequent peripheral inward dipping normal faults. Our results suggest that contraction is a direct product of magma emplacement along divergent plate boundaries, at various scales, marking a precise evolutionary stage and initiating part of the extensional structures (extension fractures and normal faults). Key Points Contraction along divergent plate boundaries results from dike emplacementContraction generates extensional structures along divergent plate boundariesSurface deformation along divergent plate boundaries may be magma induced

  12. ALLOSTRATIGRAPHY AND SEISMIC STRATIGRAPHY OF THE MIOCENE SEDIMENTS OF THE SPICCHIAIOLA - POMARANCE AREA, SOUTHERN SIDE OF THE VOLTERRA BASIN (TUSCANY, ITALY

    Directory of Open Access Journals (Sweden)

    ALESSANDRO BOSSIO LUCA MARIA FORESI

    1997-11-01

    Full Text Available The objective of this work is to analyze the Miocene depositional units of the southern side of the Volterra Basin (Tuscany, Italy utilizing outcrop and seismic data and to establish the major events that led to their formation. Four depositional units have been recognized: Unit 1 is characterized by marine sediments of late Serravallian-early Tortonian age; Unit 2 is characterized by fluvio-lacustrine and brackish deposits of late Tortonian-early Messinian age; Unit 3 is characterized by marine deposits of early Messinian age; Unit 4 is characterized by the lacustrine deposits ("Lago-mare" facies of late Messinian age. The deposition of these four units is associated with an extensional tectonic regime that has been active in Tuscany since the late Tortonian. This regime generated half graben type structures in which deposition occurred. The recognized unconformities between the units are mainly related to uplift as a consequence of the extensional tectonic regime.    

  13. Geophysical investigations of the East Greenland Caledonides using receiver functions, gravity and topography data

    DEFF Research Database (Denmark)

    Schiffer, Christian; Balling, N.; Jacobsen, B. H.

    The present-day topography and crustal structure of the East Greenland Caledonides are a product of various events, including the Caledonian orogeny, lithospheric extensional collapse, continental breakup and erosional processes. The topographic elevation appears high in this region, still after...... considering erosional uplift, connected to fjord formation. This apparent longevity of topography remains a matter of discussion. In this context the relationship of topography to crustal thickness and isostasy is a central aspect. Erosion and possible subcrustal processes are of further importance. Shallow...... crustal structures related to extensional basin formation, a lower crustal high velocity layer and a crustal root have to be considered. A profile of 11 temporary broadband stations was deployed and maintained by Aarhus University for a period of 2 years (2009 – 2011). The approximately 270 km long Ella Ø...

  14. Analysis of scalar dissipation in terms of vorticity geometry in isotropic turbulence

    CERN Document Server

    Gonzalez, Michel

    2016-01-01

    The mechanisms promoting scalar dissipation through scalar gradient production are scrutinized in terms of vorticity alignment with respect to strain principal axes. For that purpose, a stochastic Lagrangian model for the velocity gradient tensor and the scalar gradient vector is used. The model results show that the major part of scalar dissipation occurs for stretched vorticity, namely when the vorticity vector aligns with the extensional and intermediate strain eigenvectors. More specifically, it appears that the mean scalar dissipation is well represented by the sample defined by alignment with the extensional strain, while the most intense scalar dissipation is promoted by the set of events for which vorticity aligns with the intermediate strain. This difference is explained by rather subtle mechanisms involving the statistics of both the strain intensities and the scalar gradient alignment resulting from these special alignments of vorticity. The analysis allowing for the local flow structure confirms t...

  15. The earthquake cycle in subduction zones

    Science.gov (United States)

    Melosh, H. J.; Fleitout, L.

    1982-01-01

    A simplified model of a subduction zone is presented, which incorporates the mechanical asymmetry induced by the subducted slab to anchor the subducting plate during post-seismic rebound and thus throw most of the coseismic stream release into the overthrust plate. The model predicts that the trench moves with respect to the deep mantle toward the subducting plate at a velocity equal to one-half of the convergence rate. A strong extensional pulse is propagated into the overthrust plate shortly after the earthquake, and although this extension changes into compression before the next earthquake in the cycle, the period of strong extension following the earthquake may be responsible for extensional tectonic features in the back-arc region.

  16. Role of magmatism in continental lithosphere extension: an introduction to tectnophysics special issue

    Energy Technology Data Exchange (ETDEWEB)

    Van Wijk, Jolante W [Los Alamos National Laboratory

    2008-01-01

    The dynamics and evolution of rifts and continental rifted margins have been the subject of intense study and debate for many years and still remain the focus of active investigation. The 2006 AGU Fall Meeting session 'Extensional Processes Leading to the Formation of Basins and Rifted Margins, From Volcanic to Magma-Limited' included several contributions that illustrated recent advances in our understanding of rifting processes, from the early stages of extension to breakup and incipient seafloor spreading. Following this session, we aimed to assemble a multi-disciplinary collection of papers focussing on the architecture, formation and evolution of continental rift zones and rifted margins. This Tectonophysics Special Issue 'Role of magmatism in continental lithosphere extension' comprises 14 papers that present some of the recent insights on rift and rifted margins dynamics, emphasising the role of magmatism in extensional processes. The purpose of this contribution is to introduce these papers.

  17. Breaking supercontinents; no need to choose between passive or active

    Science.gov (United States)

    Wolstencroft, Martin; Davies, J. Huw

    2017-08-01

    Much debate has centred on whether continental break-up is predominantly caused by active upwelling in the mantle (e.g. plumes) or by long-range extensional stresses in the lithosphere. We propose the hypothesis that global supercontinent break-up events should always involve both. The fundamental principle involved is the conservation of mass within the spherical shell of the mantle, which requires a return flow for any major upwelling beneath a supercontinent. This shallow horizontal return flow away from the locus of upwelling produces extensional stress. We demonstrate this principle with numerical models, which simultaneously exhibit both upwellings and significant lateral flow in the upper mantle. For non-global break-up the impact of the finite geometry of the mantle will be less pronounced, weakening this process. This observation should motivate future studies of continental break-up to explicitly consider the global perspective, even when observations or models are of regional extent.

  18. Alignment of Disks with Lagrangian Stretching in Turbulence

    Science.gov (United States)

    Hunt, Conor; Tierney, Lydia; Kramel, Stefan; Voth, Greg

    2015-11-01

    We study Lagrangian stretching in isotropic turbulence in order to understand both the rotations of disks and the preferential alignment of vorticity with the intermediate strain rate eigenvector. Using velocity gradient tensors from a numerical simulation of homogeneous isotropic turbulence at Rλ = 180, we calculate the Cauchy-Green strain tensors whose eigenvectors provide a natural basis for studying stretching phenomenon. Previous work has shown that rods preferentially align with the vorticity as a result of both quantities independently aligning with the extensional Cauchy-Green eigenvector. In contrast, disks orient with their symmetry axis perpendicular to vorticity and preferentially align with the compressional Cauchy-Green eigenvector. We also find that the intermediate strain rate eigenvector is aligned with the extensional Cauchy-Green eigenvector. A natural consequence is that the intermediate strain rate eigenvector is aligned with the vorticity vector since conservation of angular momentum aligns vorticity with the direction it has been stretched.

  19. Stress growth and relaxation of dendritically branched macromolecules in shear and uniaxial extension

    DEFF Research Database (Denmark)

    Huang, Qian; Costanzo, S.; Das, C.

    2017-01-01

    stress relaxation, suggesting a strong ‘elastic memory’ of the material. These results are 2 described by BoB semi-quantitatively, both in linear and nonlinear shear and extensional regimes. Given the fact that the segments between branch points are less than 3 entanglements long, this is a very...... of the remarkable properties of these highly branched macromolecules. In particular, we address three questions pertinent to the specific molecular structure: (i) is steady state attainable during uniaxial extension? (ii) what is the respective transient response in simple shear? and (iii) how does stress relax...... the Branch-on-Branch (BoB) algorithm. The data indicates that the extensional viscosity reaches a steady state value, whose dependence on extension rate is identical to that of entangled linear and other branched polymer melts. Nonlinear shear is characterized by transient stress overshoots and the validity...

  20. Effect of Hydrogen Bonding on Linear and Nonlinear Rheology of Entangled Polymer Melts

    DEFF Research Database (Denmark)

    Shabbir, Aamir; Goldansaz, Hadi; Hassager, Ole

    2015-01-01

    to AA along the backbone. Assuming superposition holds and subtracting out the linear chain rheology from LVE, the hydrogen bonding contribution to LVE is exposed. Hydrogen bonding affects linear viscoelasticity at frequencies below the inverse reptation time. More specifically, the presence of hydrogen...... bonds causes G′ and G″ as a function of frequency to shift to a power law scaling of 0.5. Furthermore, the magnitude of G′ and G″ scales linearly with the number of hydrogen-bonding groups. The nonlinear extensional rheology shows extreme strain hardening. The magnitude of extensional stress has...... a strongly nonlinear dependence on the number of hydrogenbonding groups. These results are aimed at uncovering the molecular influence of hydrogen bonding on linear and nonlinear rheology to aid future molecular synthesis and model development....

  1. Stress relaxation following uniaxial extension of polystyrene melt and oligomer dilutions

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik K.

    2016-01-01

    The filament stretching rheometer has been used to measure the stress relaxation following the startup of uniaxial extensional flow, on anarrow molar mass distribution (NMMD) polystyrene melt and styrene oligomer dilutions thereof. All samples used here were characterizedin molecular weight......, mechanical spectroscopy, and constant strain rate uniaxial extension in the work of Huang et al. [Macromolecules 46,5026–5035 (2013); ACS Macro Lett. 2, 741–744 (2013)]. The stress relaxation following the steady extensional stress was measured on a285 kg/mole NMMD polystyrene and two 1.92 kg/mole styrene...... oligomer dilutions thereof {PS-285k, PS-285k/2k-72, and PS-285k/2k-44 inthe work of Huang et al. [Macromolecules 46, 5026–5035 (2013)]}. The two dilutions contained 28 and 56 wt. % oligomer, respectively.Further, the stress relaxation on a 545 kg/mole NMMD polystyrene diluted with 48 wt. % 0.972 kg...

  2. Geological Mapping of the Lada Terra (V-56) Quadrangle, Venus

    Science.gov (United States)

    Kumar, P. Senthil; Head, James W., III

    2009-01-01

    Geological mapping of the V-56 quadrangle (Fig. 1) reveals various tectonic and volcanic features and processes in Lada Terra that consist of tesserae, regional extensional belts, coronae, volcanic plains and impact craters. This study aims to map the spatial distribution of different material units, deformational features or lineament patterns and impact crater materials. In addition, we also establish the relative age relationships (e.g., overlapping or cross-cutting relationship) between them, in order to reconstruct the geologic history. Basically, this quadrangle addresses how coronae evolved in association with regional extensional belts, in addition to evolution of tesserae, regional plains and impact craters, which are also significant geological units of Lada Terra.

  3. Argumentação e persuasão: tensão entre crer e saber em "Famigerado", de Guimarães Rosa

    Directory of Open Access Journals (Sweden)

    Waldir Beividas

    2009-12-01

    Full Text Available

    Diferentemente de outras teorias mais próximas da retórica, a semiótica da Escola de Paris nunca foi muito pródiga ao tratar dos problemas de persuasão e argumentação. A partir de uma constatação simples como essa, procuramos, neste artigo, pôr à prova certos dispositivos semióticos que têm suas consequências nesse domínio, a começar pela problemática modal do crer e do saber. Seus valores são examinados num tipo de situação específi ca, a saber, quando as personagens confrontadas se acham em circunstância de ameaça imediata a sua integridade física. Nesse sentido, discutimos três tópicos principais: (i a interação dos valores modais do saber e do crer, componentes de um mesmo universo cognitivo; (ii as modulações tensivas do medo e das paixões correlatas; (iii as formas de raciocínio inferencial mobilizadas pelas personagens do relato, e notadamente as ilações abdutivas postas em cena. O texto escolhido para a verifi cação do alcance e dos limites de tais dispositivos semióticos é o conhecido conto de Guimarães Rosa, “Famigerado” (Primeiras estórias, obra originalmente publicada em 1962.

  4. Diagnóstico como nome próprio Diagnostic as first name

    Directory of Open Access Journals (Sweden)

    Daiana Paula Milani Baroni

    2010-04-01

    Full Text Available Este artigo apresenta reflexões dentro do campo da saúde mental, considerada aqui enquanto produção histórica correlata ao surgimento da psiquiatria e do seu objeto, a doença mental. O intuito é o de problematizar, junto à emergência deste saber sobre o sujeito que dita modos de vida, a identificação com o nome de um diagnóstico e demais questões que perpassam a temática da medicalização, a fim de introduzir a discussão da saúde mental em uma perspectiva crítica. Pensar sobre as possibilidades de produção de outros nomes para o sujeito, de novas formas de subjetividade, requer a busca por pontos onde resistências se apresentem, onde novas práticas de si referentes ao corpo e à saúde possam conduzir a novos nomes para a saúde.This article presents some reflections on mental health, considered in this context as historical production in correlation with the emergence of psychiatry and its object - mental disease. It intends to discuss, along with the emergence of this knowledge that creates forms of life to the subject, the process of identification with a diagnostic name and other questions that pass through the thematic of medicalization, introducing the mental health's discussion in a critical perspective. To think about the production of other names to the subject, new kinds of subjectivities, requires searching for points of resistance, where new practices of oneself in reference to the body and health can conduce to new names for health.

  5. Cruetzfieldt Jakob Disease e sindromi correlate Il centro di riferimento Piemontese e la sua sorveglianza epidemiologica

    Directory of Open Access Journals (Sweden)

    G. Catapano

    2003-05-01

    Full Text Available

    Le encefalopatie spongiformi trasmissibili (EST sono malattie del sistema nervoso dell’uomo, ad esito infausto. L’agente eziologico, la proteina prionica (PrP, può trasformarsi e accumularsi nella cellula nervosa causandone la morte. La scoperta negli anni ‘90 di una variante (v. Cruetzfieldt Jakob Disease, correlata all’encefalopatia spongiforme bovina, che colpisce soggetti sotto i 30 anni, ha aumentato l’interesse per le EST.

    I paesi della comunità europea hanno adottano misure di controllo della carne bovina e si sono dotati di osservatori epidemiologici. Pertanto anche in Italia si è avuta l’esigenza di doverne disporre. Si è deciso quindi di istituire anche in Piemonte un centro per la sorveglianza e la notifica delle EST tramite sorveglianza epidemiologica e diagnosi, per mezzo di indagini molecolari e neuropatologiche con la successiva costituzione di una banca dati condivisa con altri centri di riferimento regionali, per la raccolta di dati clinici e strumentali dai reparti di neurologia piemontesi con ricovero in sede dei casi di EST giunti all’osservazione.

    In sede vengono effettuati anche il prelievo, la raccolta, la conservazione di tessuti e altri materiali biologici e si svolgono successive indagini neurobiologiche quali:

     1 la ricerca della proteina 14 3 3 su liquor;

     2 determinazione genotipo del codone 129;

     3 determinazione della sequenza del gene della PrP,

     4 ricerca della PrP proteasi resistente a livello tissutale;

     5 determinazione del sottotipo di PrP. Le indagini neuropatologiche vengono effettuate in collaborazione con dipartimento di Neuroscienze dell’Università di Torino. Si intende inoltre fare promozione attiva delle attività e condivisione delle informazioni raccolte con altri centri.

  6. A Arquivologia e os videogames: primeiras aproximações

    Directory of Open Access Journals (Sweden)

    Roberto Lopes dos Santos Junior

    2016-12-01

    Full Text Available Análise, baseado em levantamento bibliográfico e revisão de literatura em fontes secundárias, identificando, preliminarmente, o “estado da arte” das pesquisas e trabalhos ligados a Arquivologia (e áreas correlatas como Ciência da Informação e Biblioteconomia sobre os videogames. Inicialmente foi feito breve estudo histórico sobre a origem e evolução dos jogos eletrônicos, entre a segunda metade do século vinte e os primeiros anos do século 21. Posteriormente, foram analisadas as principais temáticas localizadas na literatura arquivística sobre os videogames, separadas, respectivamente, nas pretensas características documentais dessas mídias, dos aspectos teóricos ligados a preservação dos videogames, e sobre as estratégias de emulação, encapsulamento, e da utilização de repositórios e museus tecnológicos para o armazenamento desses suportes. O trabalho identificou a existência, principalmente após 2005, de estudos, ligados a Arquivologia norte-americana e europeia, indicando a necessidade de análises aprofundadas sobre diferentes características presentes nos videogames, apesar dos objetivos e premissas que consolidem essas pesquisas ainda estarem em fase de desenvolvimento. O levantamento indicou também que a temática possui potencial de desenvolvimento na Arquivologia brasileira.

  7. Sexualidade e medicina: a revolução do século XX: the 20th-century sexual revolution

    Directory of Open Access Journals (Sweden)

    Loyola Maria Andréa

    2003-01-01

    Full Text Available O artigo discute a contribuição da medicina, segundo o controle normativo e tecnológico da sexualidade feminina e do processo reprodutivo (parto, aleitamento, contracepção e tratamento das infertilidades para a construção, durante o século XX, de um novo modelo de reprodução (biológica e social, calcado em uma mudança radical das identidades e das relações e formas de união entre os sexos (desagregação de laços matrimoniais tradicionais, crescimento das uniões consensuais, monogamia serial, etc.. Este modelo se sustenta em uma separação radical entre sexualidade e reprodução correlata de um modelo único e horizontal de sexualidade (contrariamente ao modelo hierárquico dos dois sexos do século XIX, dirigida primordialmente para o prazer e progressivamente desvinculada dos laços sociais e afetos que lhes são correspondentes. Discute, além da contribuição da medicina (notadamente a partir dos efeitos da reprodução assistida e da sexologia (universalização do imperativo do orgasmo, a contribuição da epidemiologia (por meio das pesquisas relacionadas à AIDS para a transformação de uma normal moral sobre a sexualidade em uma norma abstrata e meramente estatística.

  8. Capilaroscopia periungueal: importância para a investigação do fenômeno de Raynaud e doenças do espectro da esclerose sistêmica Importance of the nailfold capillaroscopy in the investigation of Raynaud's phenomenon and scleroderma-spectrum syndromes

    Directory of Open Access Journals (Sweden)

    Cristiane Kayser

    2004-02-01

    Full Text Available A capilaroscopia periungueal é um exame não invasivo e extremamente útil para avaliação do componente morfológico da microcirculação. Permite o diagnóstico diferencial precoce entre indivíduos com fenômeno de Raynaud (FRy primário e secundário. Na esclerose sistêmica e síndromes correlatas ocorrem alterações capilaroscópicas facilmente distinguíveis do padrão encontrado em indivíduos normais, sendo caracterizadas pela presença de ectasia capilar e áreas de deleção vascular, além de diminuição difusa da quantidade de alças. Em razão de sua relevância diagnóstica, a familiarização do médico clínico e do reumatologista com a CPU é de fundamental importância.Nailfold capillaroscopy is a noninvasive method useful for the evaluation of microcirculation morphologic component. It allows an early differential diagnosis between subjects with primary Raynaud's phenomenon and patients with secondary Raynaud's phenomenon. In systemic sclerosis and sclerodermaspectrum syndromes there are capillaroscopic findings easily distinguished from the pattern of healthy controls, and characterized by the presence of enlarged loops, avascular areas and diffuse loss of capillaries. Because of their diagnostic relevance, the acquaintance of internists and rheumatologists with nailfold capillaroscopy is of utmost importance.

  9. Edema pulmonar neurogênico: uma revisão atualizada da literatura

    Directory of Open Access Journals (Sweden)

    Flávio Antônio Siqueira Ridenti

    2012-03-01

    Full Text Available O edema pulmonar neurogênico ainda é um fenômeno pouco compreendido no contexto da assistência ao paciente neurológico grave. Trata-se de uma situação clínica relativamente rara. Situações de importante dano cerebral como hemorragia subaracnóidea, traumatismos encefálicos severos, hemorragias cerebrais intra-parenquimatosas, crises convulsivas ou outras condições específicas fazem o perfil do paciente com risco de desenvolver edema pulmonar neurogênico. A falta de reconhecimento desta condição e o seu inadequado manuseio podem levar à piora do sofrimento cerebral por adicional lesão cerebral secundária em decorrência de hipoxemia e de redução da pressão de perfusão cerebral com aumento da morbidade e da letalidade. O objetivo desta revisão foi o de levantar aspectos atuais da fisiopatologia do edema pulmonar neurogênico, sua importância clínica e terapêutica. Embora de ocorrência relativamente rara, o edema pulmonar neurogênico deve ser prontamente reconhecido e tratado para que se evite dano cerebral secundário adicional. Apesar de ainda não totalmente elucidado, o conhecimento da base da fisiopatologia tem importância na estratégia do seu manuseio. Deve-se ter em mente a identificação de diagnósticos diferenciais como pneumonia aspirativa, embolia pulmonar, contusão pulmonar, congestão por sobrecarga de volume dentre outras situações. De forma semelhante, devem ser consideradas situações correlatas como a síndrome do miocárdio atordoado ("stunned myocardium" que podem estar presentes ou associadas ao edema pulmonar neurogênico.

  10. Fatores terapêuticos em um grupo de apoio para pacientes psiquiátricos ambulatoriais

    Directory of Open Access Journals (Sweden)

    Guanaes Carla

    2001-01-01

    Full Text Available INTRODUÇÃO/OBJETIVOS: O emprego da psicoterapia de grupo no atendimento em saúde mental, sobretudo em contextos institucionais, tem se expandido aceleradamente, não havendo uma expansão correlata de pesquisas na área, conforme aponta a literatura especializada. Objetivou-se compreender algumas possibilidades e alguns limites de um grupo de apoio de curta duração (16 sessões para pacientes psiquiátricos ambulatoriais, investigando os fatores terapêuticos que operam nesse grupo, segundo a percepção de seus participantes. MÉTODOS: Questionários do Incidente Crítico (QIC, observação e registro do grupo, consultas aos prontuários dos pacientes e notas de campo constituíram as fontes de dados. A análise das respostas dos pacientes ao QIC foi realizada por procedimentos de avaliação categorial de conteúdo, tendo como base um sistema descritivo dos fatores terapêuticos proposto na literatura. As demais fontes foram tomadas como dados de contexto dos sentidos produzidos pelos pacientes em suas respostas ao QIC. RESULTADOS: Os resultados remetem a dez categorias derivadas da percepção dos pacientes, indicativas de vivências terapêuticas e não-terapêuticas no grupo. DISCUSSÃO/CONCLUSÃO: Este estudo possibilita uma compreensão sobre o modo como os pacientes vivenciaram o processo desse grupo, tendo em vista os sentidos que produziram a partir de sua participação neste, e, em conjunção com a compreensão de seus quadros clínicos, situa algumas possibilidades e alguns limites desse tipo de tratamento em saúde mental, considerando o contexto em que ocorre e a clientela que usualmente o integra.

  11. Chagasic megacolon and large bowel neoplasms: case series and literature review

    Directory of Open Access Journals (Sweden)

    Maxwel Capsy Boga Ribeiro

    2011-12-01

    Full Text Available There is a clear association between chagasic megaesophagus and the esophageal cancer. On the other hand, the association between chagasic megacolon and intestinal neoplasm is uncommon. There are only a few cases described in literature. We selected two cases of colorectal adenocarcinoma associated with adenoma from 2000 to 2011, which are added to the four patients already described by this group. The mean age of the patients, was 68.5 years. Both had been submitted to surgical resection of the neoplasm. Survival rates ranged and were directly related to tumor staging at the time of diagnosis. In this context, we report our case series and reviwed the corresponding literature, especially the clinical and epidemiological aspects of this rare association.Há uma clara associação entre megaesôfago por doença de Chagas e o câncer esofágico. Ao contrário, tal relação, entre megacólon chagásico e neoplasias do intestino grosso é, reconhecidamente, incomum. Existem poucos casos relatados na literatura. Destacamos, entre 2000 e 2011, dois casos, sendo ambos adenocarcinomas colorretais e associados a adenomas, que se somam aos outros quatro já descritos por este grupo. A média de idade dos pacientes, foi de 68,5 anos. Todos foram submetidos à ressecção cirúrgica da neoplasia. A sobrevida foi variável e diretamente relacionada ao estádio do tumor no momento do diagnóstico. Dentro desse contexto, relatamos essa série de casos e revisamos a literatura correlata, com relação aos aspectos clínicos e epidemiológicos dessa rara associação.

  12. Interseccionalidade em uma era de globalização: As implicações da Conferência Mundial contra o Racismo para práticas feministas transnacionais

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    BLACKWELL MAYLEI

    2002-01-01

    Full Text Available Este relatório analisa a interseccionalidade como uma abordagem feminista com significante impacto nos discursos e debates durante o Fórum de ONGs e a Conferência Mundial Contra o Racismo, em Durban, África do Sul. O termo 'interseccionalidade' se refere às articulações entre a discriminação de gênero, a homofobia, o racismo e a exploração de classe. Falando do lugar de enunciação de mulheres de cor feministas situadas nos territórios geográficos dos Estados Unidos, as autoras enfatizam algumas questões-chave e tendências dos movimentos sociais que foram ignoradas pela mídia estadunidense. Alternativamente, o relatório examina como a introdução das 'intolerâncias correlatas' na agenda da Conferência permitiu discussões mais amplas sobre os efeitos da globalização no agravamento do racismo e sobre as múltiplas opressões com relação à orientação sexual e aos direitos sexuais. As autoras argumentam que uma insistência na significância do gênero e da raça, bem como da classe, no contexto do capitalismo neo-liberal, coloca novas e importantes coordenadas nos mapas do feminismo transnacional e do crescente movimento anti-globalização.

  13. RELATO DE EXPERIÊNCIA PARA APOIO A UM PERIÓDICO CIENTÍFICO

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    Gustavo Teodoro Bullé

    2014-09-01

    Full Text Available A Tecno Lógica é uma revista de publicação semestral, do Departamento de Química e Física, Departamento de Engenharia, Arquitetura e Ciências Agrárias, do Programa de Pós-Graduação em Tecnologia Ambiental e do Programa de Pós-Graduação em Sistemas e Processos Industriais. A revista promove e possibilita o desenvolvimento da ciência com enfoque na formação cientifica, em especial buscando socializar soluções para as áreas de Tecnologia Ambiental e Sistemas e Processo Industriais, publicando resultados de pesquisas primária e/ou secundária, em temas voltados para inovação, tecnologia, gestão, meio ambiente, melhoria e otimização de processos e áreas correlatas. Umas das atividades realizadas foi à capacitação sobre a utilização da ferramenta SEER - Sistema de Editoração Eletrônica de Revistas - software do IBICT, que é utilizado na editoração oferecendo vantagens e qualidade aos periódicos científicos publicados. Serão descritas, também, as funções do Editor Gerente, Editor, Avaliador e Autor, que customizam o processo de edição e reduzem o tempo, melhorando o desempenho de todos os envolvidos no processo de editoração e a qualidade dos periódicos científicos. Também foi realizada uma pesquisa que visava buscar pesquisadores, professores, alunos, enfim várias pessoas de todo o Brasil e de diferentes universidades convidando-os a submeter artigos e conhecer nossa Revista.

  14. Circovirose suína Porcine circovirosis: a review

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    Ticiana do Nascimento França

    2005-06-01

    Full Text Available Por meio de revisão da literatura pertinente foram coligidos e são apresentados os principais dados relativos aos aspectos epidemiológicos, clínicos, anátomo e histopatológicos observados na infecção por Circovírus Porcino tipo 2 (PCV-2 em suínos. São abordados a Síndrome Definhante Multissistêmica dos Suínos Desmamados (SDMDS, o Tremor Congênito Suíno (TCS, a Síndrome da Nefropatia e Dermatite Porcina (SNDP, bem como outras enfermidades associadas ou correlatas, a Síndrome Respiratória e Reprodutiva Porcina (SRRP, a Pneumonia Necrotizante Proliferativa (PNP e as falhas reprodutivas. Uma vez que a SDMSD já foi registrada na Região Sul do Brasil e no Estado do Rio de Janeiro esse estudo objetiva chamar a atenção para o especial significado dessa virose para a suinocultura brasileira, em função dos prejuízos econômicos por ela determinados.The literature of Porcine Circovirosis, including the main data on epidemiology and clinical, macroscopic and microscopic alterations of the infection of swine by Porcine Circovirus type 2 (PCV-2, is reviewed. There are various forms of infection: the [Porcine] Postweaning Multisystemic Wasting Syndrome (PMWS, Porcine Congenital Tremor, Porcine Dermatitis and Nephropathy Syndrome, and other associated or correlated diseases as the Porcine Reproductive and Respiratory Syndrome, Proliferative Necrotizing Pneumonia, and reproductive disorders. As PMWS already has been reported from southern Brazil and from the state of Rio de Janeiro, the objective of this review is to draw attention to the implications of this virosis for swine production in Brazil and its economical importance.

  15. Separação e identificação de aditivos em tinta por TLC-IR/ UATR e extração seletiva

    Directory of Open Access Journals (Sweden)

    Viviane Cristine Rodrigues

    2016-01-01

    Full Text Available Resumo Vários aditivos são incorporados nas formulações de tintas para evitar defeitos no revestimento e melhorar o desempenho nas aplicações, constituindo, desse modo, um sistema complexo. A caracterização de uma composição pode ser realizada por separações física/ química e técnicas analíticas instrumentais. A análise de multicomponentes é utilizada no estudo de não conformidades, investigação forense e pesquisa e desenvolvimento de novos produtos. As pesquisas correlatas, em geral, utilizam metodologias convencionais, encontrando algumas limitações, o que motiva a utilização de técnicas alternativas, incluindo acoplamentos, para a análise de aditivos em tintas. Nesse contexto, foi avaliada a aplicabilidade do acoplamento (indireto ou off-line das técnicas de cromatografia de camada fina (TLC e espectroscopia no infravermelho com transformada de Fourier (FT-IR, denominado TLC-IR, e extração seletiva na análise de aditivos em tinta à base de resina poliuretânica (PU e nitrocelulose (NC. Foi utilizada uma formulação, avaliados três sistemas de eluentes e um tipo de revelador, o de Gibbs. Os espectros FT-IR foram obtidos por Reflexão Total Atenuada Universal (UATR. Os principais resultados mostraram que o plastificante Acetil Tributil Citrato (ATBC, aditivo majoritário, foi facilmente identificado por TLC-IR. A metodologia permitiu detectar e diferenciar plastificantes do tipo ftalato, como dioctil ftalato (DOP e dibutil ftalato (DBP, mesmo em pequena quantidade de amostra, e identificar a oleamida (aditivo promotor de deslize por meio de extração seletiva e UATR.

  16. Revista Multitexto do CEAD/Unimontes: um periódico científico na produção de qualidade de gestão em EAD

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    Maria Ângela Lopes Dumont Macedo

    2015-06-01

    Full Text Available As atuais tendências de gestão em educação fazem usufruto de inúmeras ferramentas de ação e inovação para a consecução de suas metas e resultados. Todavia, é preciso que as metas sejam investidas de rigor e vigor para fundamentar ações, gerar pertinência, garantir relevância e alcançar eficácia. A pesquisa científica surge como uma proposta singular para a aplicação de qualidade em processos de gestão nas várias instâncias. Como marco de sua gestão, o Centro de Educação a Distância da Universidade Estadual de Montes Claros – CEAD/Unimontes instituiu a Revista Multitexto do CEAD/Unimontes. Um periódico científico que condense produções científicas em EAD e áreas correlatas. O objetivo desse trabalho foi relatar a experiência de implantação da Revista Multitexto no CEAD/Unimontes. Através de um relato de experiência, destacou-se a trajetória de implantação, comunicando a preocupação da instituição e movimentos de sua gestão. Por certo que um periódico científico investe, através da ciência, valores de relevância e fundamentação, e nesse ínterim, competem diretamente para a consecução e objetivos e aplicação de qualidade em processos de gestão, como a em EAD.

  17. O Sistema Político Brasileiro hoje: o governo do Supremo Tribunal Federal e legitimidade democrática

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    Eduardo Santos de Oliveira

    2013-08-01

    Full Text Available Numa perspectiva tradicional, cujo quadro teórico é a teoria da separação de poderes, de formulação europeia continental, os órgãos do Poder Judiciário não são vistos como elementos genuínos do sistema governamental. Este artigo tem com objetivo central propor e desenvolver a tese de que o Supremo Tribunal Federal é um elemento original do governo brasileiro. Adotou-se como contraponto crítico a ideia bem difundida de que qualquer ato de governo do Supremo Tribunal Federal implica uma usurpação na forma de uma assim chamada judicialização da política. Buscou-se evidenciar, contra crenças ainda não de todo modificadas, a atuação precípua e funcional do Supremo na produção do discurso político, bem como identificar a forma como os ministros do Supremo Tribunal Federal se posicionam em relação ao fato de atuarem na produção da ordem política. Buscou-se, ainda, através da análise do conteúdo dos votos proferidos pelos ministros, registrar a presença de palavras ou expressões que configurassem, dentro do discurso principal, metadiscursos, que dessem alguma pista acerca da autoimagem e legitimidade correlata.

  18. Comunidade arbórea de uma floresta estacional decídua sobre afloramento calcário na Bacia do rio Paraná Arboreal community of a seasonal deciduous forest on limestone outcrop in São Domingos - Goiás, Parana river Basin, Brazil

    Directory of Open Access Journals (Sweden)

    Luciana Álvares da Silva

    2004-02-01

    Full Text Available A bacia do rio Paraná (GO e TO, com 5.940.382 ha, tem alta diversidade de fitofisionomias, com sua flora pouco conhecida. As atividades de extração de madeira e implantação de pastagem contribuíram decisivamente para a remoção da vegetação. Este estudo foi conduzido em uma floresta estacional decídua sobre afloramento calcário (aproximadamente 13º41'16"S e 46º44'20"W e 462 m de altitude - fazenda Canadá (São Domingos-GO. Foram demarcadas cinco linhas paralelas, a intervalos de 100 m, onde foram distribuídas aleatoriamente 25 parcelas de 20 x 20 m (total de 1 ha. Em cada parcela foram amostradas todas as árvores com diâmetro do caule a 1,3 m de altura do solo (DAP > 5 cm, nos quais foi medido o DAP, estimada a altura máxima e identificada a espécie. Foram amostrados 924 indivíduos de 48 espécies, 38 gêneros e 24 famílias e obtidos o índice de Shannon-Wienner de 2,99 nats/ind. e a equabilidade de 0,77. As espécies que apresentaram maior valor de importância (VI foram Myracrodruon urundeuva (36,09, Pseudobombax tomentosum (34,75, Dilodendron bipinnatum (26,61, Combretum duarteanum (22,19, Jacaranda brasiliana (21,57, Commiphora leptophloeos (19,18, Astronium fraxinifolium (13,84, Tabebuia impetiginosa (13,79, Pseudobombax longiflorum (11,64 e Machaerium scleroxylon (10,00, que juntas somaram 69,9% do VI total. A diversidade foi próxima à encontrada em outros trabalhos em floresta estacional decídua sobre solo e afloramento na região.The Parana River basin - an area of 5,940,382 ha located in Brazil- has a highly diverse phytophysiognomy and scarce flora information. Wood extraction and pasture activities have decisively contributed to the removal of vegetation in this area. This study was carried out in a seasonal deciduous forest on limestone outcrop (approximately 13º41'16" S and 46º44'20" W on Canada Farm (São Domingos-GO. Twenty -five plots of 20 m x 20m (1 ha were randomly allocated on parallel lines 100 m

  19. Magmatic and solid state structures of the Abu Ziran pluton: Deciphering transition from thrusting to extension in the Eastern Desert of Egypt

    Science.gov (United States)

    Fritz, Harald; Loizenbauer, Jürgen; Wallbrecher, Eckart

    2014-11-01

    The 606 Ma old Abu Ziran granite of the Eastern Desert of Egypt intruded the southern margin of the Meatiq dome in a sinistral shear extensional setting. Its emplacement was enabled by a system of NW-trending sinistral shears, related Riedel shears and N-S extensional shear zones and faults. Magmatic flow was east-directed and controlled by Riedel shears that progressively rotated to an orientation favourable for extension. Strain markers that document magmatic flow show eastward decreasing strain together with strain increase from pluton centre to margins. This is explained by Newtonian flow between non-parallel plates and differences in flow velocities across the pluton. Solid state fabrics including shear fabrics, orientation of late magmatic dykes and quartz tension gashes, together with quartz C-axes distributions, document southward extensional shear within the solidified pluton and adjacent host rocks. Extensional shear is correlated with exhumation of the Meatiq dome coeval and soon after pluton solidification (585 Ma). Pressure temperature evolutionary paths, derived from fluid inclusions, show a clockwise path with exhumation by isothermal decompression in the Meatiq dome. By contrast, the overlying volcanosedimentary nappes experienced an anti-clockwise path released by temperature rise due to pluton emplacement followed by isobaric cooling. Quartz fabrics indicate high-temperature coaxial N-S flow in the northern Meatiq dome and lower-temperature, non-coaxial southward flow within the overlaying superficial nappe. This is explained by the exhumation process itself that progressively localised into simple shear domains when rocks approached higher crustal levels. Late extension at ca. 580 Ma was pure shear dominated and resulted in reversal of shear, now dextral, in the western Meatiq shear zone.

  20. Acoustic vibration modes and electron-lattice coupling in self-assembled silver nanocolumns.

    Science.gov (United States)

    Burgin, J; Langot, P; Arbouet, A; Margueritat, J; Gonzalo, J; Afonso, C N; Vallée, F; Mlayah, A; Rossell, M D; Van Tendeloo, G

    2008-05-01

    Using ultrafast spectroscopy, we investigated electron-lattice coupling and acoustic vibrations in self-assembled silver nanocolumns embedded in an amorphous Al2O3 matrix. The measured electron-lattice energy exchange time is smaller in the nanocolumns than in bulk silver, with a value very close to that of isolated nanospheres with comparable surface to volume ratio. Two vibration modes were detected and ascribed to the breathing and extensional mode of the nanocolumns, in agreement with numerical simulations.

  1. Critical Coulomb Wedge Theory Applied to Hyper-Extended Rifted Margins: A New Perspective

    Science.gov (United States)

    Nirrengarten, M.; Manatschal, G.; Yuan, X.; Kusznir, N. J.; Maillot, B.

    2016-12-01

    Field studies, borehole data and seismic sections show that hyper-extended domains at magma-poor rifted margins: 1) deform predominantly in the brittle field, 2) form wedge shape terminations of the continental crust, and 3) develop a frictional décollement between the hyper-extended crust and the underlying serpentinized mantle. These three observations are also the three requirements to apply the Critical Coulomb Wedge (CCW) theory, which describes the stability limit of a frictional wedge over a décollement. We measure the surface slope and detachment dip of hyper-extended wedges at magma-poor margins to compare them with the stability envelopes of CCW theory. Our analysis shows that lower plate margins, forming the footwall of the major extensional detachment faults, correspond to gravitational wedges. In contrast upper plate margins, forming the hanging wall of major extensional detachment faults, are tectonic extensional wedges. Dip measurements of the lower plate margins cluster on the CCW stability limits, which implies that lower plate wedges have similar shapes and that they are gravitationally stable. Upper plate margins are more complex and are not always at the critical shape due to the evolution of the underlying detachment dip and re-localization of the deformation on new detachment faults. The architecture of hyper-extended wedges results from the interaction between rocks physical properties (frictional parameters and fluid pressures) and the localization of deformation processes. Interpretation of hyper-extended domains with seismic sections is often complex due to thick post-tectonic sediments or salt layers. The application of CCW theory on hyper-extended rifted margins provides a new framework to interpret the fault pattern and its associated sedimentary architecture. In particular the application of CCW theory can explain the formation of extensional allochthons and continentward dipping faults.

  2. A hybrid Brownian dynamics/constitutive model for yielding, aging, and rejuvenation in deforming polymeric glasses.

    Science.gov (United States)

    Zou, Weizhong; Larson, Ronald G

    2016-08-10

    We present a hybrid model for polymeric glasses under deformation that combines a minimal model of segmental dynamics with a beads-and-springs model of a polymer, solved by Brownian dynamics (BD) simulations, whose relaxation is coupled to the segmental dynamics through the drag coefficient of the beads. This coarse-grained model allows simulations that are much faster than molecular dynamics and successfully capture the entire range of mechanical response including yielding, plastic flow, strain-hardening, and incomplete strain recovery. The beads-and-springs model improves upon the dumbbell model for glassy polymers proposed by Fielding et al. (Phys. Rev. Lett., 2012, 108, 048301) by capturing the small elastic recoil seen experimentally without the use of ad hoc adjustments of parameters required in the model of Fielding et al. With appropriate choice of parameters, predictions of creep, recovery, and segmental relaxation are found to be in good agreement with poly(methylmethacrylate) (PMMA) data of Lee et al. (Science, 2009, 323, 231-234). Our model shows dramatic differences in behavior of the segmental relaxation time between extensional creep and steady extension, and between extension and shear. The non-monotonic response of the segmental relaxation time to extensional creep and the small elastic recovery after removal of stress are shown to arise from sub-chains that are trapped between folds, and that become highly oriented and stretched at strains of order unity, connecting the behavior of glassy polymers under creep to that of dilute polymer solutions under fast extensional flows. We are also able to predict the effects of polymer pre-orientation in the parallel or orthogonal direction on the subsequent response to extensional deformation.

  3. Synchronous N-S and E-W extension at the Tibet-to-Himalaya transition in NW Bhutan

    Science.gov (United States)

    Cooper, F. J.; Hodges, K. V.; Parrish, R. R.; Roberts, N. M. W.; Horstwood, M. S. A.

    2015-07-01

    Despite 50 Myr of continuous continent-continent collision, contractional structures in the Himalayan-Tibetan orogen are today limited to the northern and southern margins of the system, while extension dominates much of the interior. On the Tibetan Plateau, Cenozoic E-W extension has been accommodated by strike-slip faults and extensional grabens, while N-S extension at the Tibet-to-Himalaya transition has been accommodated by the South Tibetan fault system (STFS). The genetic relationship between N-S and E-W extension is disputed, although age constraints indicate temporal overlap of at least 7 Myr. In NW Bhutan the two intersect where the STFS basal detachment is cut by the Yadong cross structure (YCS), an extensional half graben that provides a rare opportunity to constrain relative timings. We report U-Pb zircon dates from four STFS footwall leucogranites consistent with episodic magmatism during the middle-late Miocene and in situ U(-Th)-Pb monazite and xenotime dates from three metasedimentary rocks ranging from late Oligocene to middle Miocene. We suggest that amphibolite facies footwall metamorphism was ongoing at the time the basal STFS detachment initiated as a ductile structure in the middle-late Miocene. Late-stage granitic intrusions may reflect footwall melting during extensional exhumation along the STFS, but post-metamorphic and post-intrusion fabrics suggest that most displacement occurred after emplacement of the youngest granites. Some of the oldest YCS-related fabrics are found in a deformed 14 Ma leucogranite, implying middle Miocene ductile deformation. This observation, along with evidence for subsequent brittle YCS deformation, suggests that N-S and E-W extensional structures in the area had protracted and overlapping deformation histories.

  4. Responsive Copolymers for Enhanced Petroleum Recovery

    Energy Technology Data Exchange (ETDEWEB)

    McCormick, C.; Hester, R.

    2001-02-27

    The objectives of this work was to: synthesize responsive copolymer systems; characterize molecular structure and solution behavior; measure rheological properties of aqueous fluids in fixed geometry flow profiles; and to tailor final polymer compositions for in situ rheology control under simulated conditions. This report focuses on the synthesis and characterization of novel stimuli responsive copolymers, the investigation of dilute polymer solutions in extensional flow and the design of a rheometer capable of measuring very dilute aqueous polymer solutions at low torque.

  5. Transient filament stretching rheometer I: force balance analysis

    DEFF Research Database (Denmark)

    Szabo, Peter

    1997-01-01

    The filament stretching device which is used increasingly as an apparatus for measuring extensional properties of polymeric liquids isanalysed. A force balance that includes the effects of inertia and surface tension is derived.The force balance may be used to correct for the effects of inertia...... and surface tension, provided online measurements of the filament surface shape are available. In addition the question of initial asymmetry due to gravity is addressed....

  6. Patrimonio territorial y arquitectónico: El Plan Serena

    Directory of Open Access Journals (Sweden)

    Horacio Torrent Schneider

    2015-04-01

    La relación entre arquitectura y patrimonio se pone en evidencia en la lectura de las extensiones territoriales por la vigencia de una cierta densidad de arquitecturas patrimoniales y relaciones históricas, pero también paisajísticas. La repetición de signos patrimoniales semejantes hace que el lugar donde ello se produce pueda ser objeto de lectura patrimonial en tanto territorio.

  7. The timing and sources of intraplate magmatism related to continental breakup in southern New Zealand

    DEFF Research Database (Denmark)

    van der Meer, Quinten

    The long history of New Zealand as Gondwana’s eastern active margin ended at ~110 Ma when extensional tectonics initiated. In New Zealand’s inboard Western Province this is expressed in the formation of metamorphic core complexes and the syn-tectonic intrusion of the latest large scale subduction...... of lithospheric mantle with HIMU-type enriched veins. Chemical similarities suggest that contemporaneous and younger intraplate magmatism in New Zealand may also be derived from the same or similar sources...

  8. Tectonics and volcanism of Eastern Aphrodite Terra, Venus - No subduction, no spreading

    Science.gov (United States)

    Hansen, Vicki L.; Phillips, Roger J.

    1993-01-01

    Eastern Aphrodite Terra, a deformed region with high topographic relief on Venus, has been interpreted as analogous to a terrestrial extensional or convergent plate boundary. However, analysis of geological and structural relations indicates that the tectonics of eastern Aphrodite Terra is dominated by blistering of the crust by magma diapirs. The findings imply that, within this region, vertical tectonism dominates over horizontal tectonism and, consequently, that this region is neither a divergent nor a convergent plate boundary.

  9. Secular cooling of the earth as a source of intraplate stress

    Science.gov (United States)

    Solomon, Sean C.

    1987-01-01

    As a result of secular cooling and contraction of the earth, an increasingly extensional horizontal stress is imposed on the central portions of the plates. While the rate of increase of this stress is small in most situations, it is enhanced for large plates and during any episodes of accelerated global cooling. This source of stress may have contributed to the rifting and breakup of long-lived supercontinental plates.

  10. High Resolution Vp and Vp/Vs Local Earthquake Tomography of the Val d'Agri Region (Southern Apennines, Italy).

    Science.gov (United States)

    Improta, L.; Bagh, S.; De Gori, P.; Pastori, M.; Piccinini, D.; Valoroso, L.; Anselmi, M.; Buttinelli, M.; Chiarabba, C.

    2015-12-01

    The Val d'Agri (VA) Quaternary basin in the southern Apennines extensional belt hosts the largest oilfield in onshore Europe and normal-fault systems with high (up to M7) seismogenic potential. Frequent small-magnitude swarms related to both active crustal extension and anthropogenic activity have occurred in the region. Causal factors for induced seismicity are a water impoundment with severe seasonal oscillations and a high-rate wastewater injection well. We analyzed around 1200 earthquakes (MLENI petroleum company. We used local earthquake tomography to investigate static and transient features of the crustal velocity structure and to accurately locate earthquakes. Vp and Vp/Vs models are parameterized by a 3x3x2 km spacing and well resolved down to about 12 km depth. The complex Vp model illuminates broad antiformal structures corresponding to wide ramp-anticlines involving Mesozoic carbonates of the Apulia hydrocarbon reservoir, and NW-SE trending low Vp regions related to thrust-sheet-top clastic basins. The VA basin corresponds to shallow low-Vp region. Focal mechanisms show normal faulting kinematics with minor strike slip solutions in agreement with the local extensional regime. Earthquake locations and focal solutions depict shallow (< 5 km depth) E-dipping extensional structures beneath the artificial lake located in the southern sector of the basin, and along the western margin of the VA. A few swarms define relatively deep transfer structures accommodating the differential extension between main normal faults. The spatio-temporal distribution of around 220 events correlates with wastewater disposal activity, illuminating a NE-dipping fault between 2-5 km depth in the carbonate reservoir. The fault measures 5 km along dip and corresponds to a pre-existing thrust fault favorably oriented with respect to the local extensional field.

  11. Guarded dependent type theory with coinductive types

    DEFF Research Database (Denmark)

    Bizjak, Aleš; Grathwohl, Hans Bugge; Clouston, Ranald

    2015-01-01

    We present guarded dependent type theory, gDTT, an extensional dependent type theory with a later' modality and clock quantifiers for programming and proving with guarded recursive and coinductive types. The later modality is used to ensure the productivity of recursive definitions in a modular...... functor rules for the later modality considered in earlier work, and are crucial for programming and proving with dependent types. We show soundness of the type theory with respect to a denotational model....

  12. Assessing the seismic coupling of shallow continental faults and its impact on seismic hazard estimates: a case-study from Italy

    Science.gov (United States)

    Carafa, Michele M. C.; Valensise, Gianluca; Bird, Peter

    2017-04-01

    We propose an objective and reproducible algorithmic path to forecast seismicity in Italy from long-term deformation models. These models are appropriate for Italy and its neighbouring countries and seas thanks to the availability of rich, reliable and regularly updated historical earthquake and seismogenic fault databases, and to the density of permanent GPS stations. However, so far little has been done to assess the seismic coupling of Italian active faults, that is to quantify their ability to release earthquakes. This must be determined in order to use geodetic and active faulting observations in alternative seismicity models, to overcome possible limitations of the earthquake record for the assessment of seismic hazard. We use a probabilistic method to assign upper crustal earthquakes from the historical catalogue to their presumed causative faults, then collect all the events into three subcatalogues corresponding to the compressional, extensional and strike-slip faulting classes. We then determine the parameters of their Gutenberg-Richter frequency/magnitude relations using maximum-likelihood methods and integrate these distributions to estimate the long-term seismic moment rate for each class. Finally, we compare these seismicity rates to the long-term tectonic deformation based on GPS data, thus determining the coupled thickness (and estimating seismic coupling) for each fault class. We find that in our study region the seismic coupling and the related coupled thickness is on average two times larger for extensional than for compressional faults. As for the spatial distribution of earthquake rates, a larger number of events is predicted for the extensional settings of the Apennines chain, in agreement with the inferred seismic coupling but also with the long-term strain rates. We also find that the frequency/magnitude distributions indicate that the largest earthquakes occur in extensional settings, whereas compressional faults are expected to host

  13. Comment on "Age and evolution of the Grand Canyon revealed by U-Pb dating of water table-type speleothems".

    Science.gov (United States)

    Pearthree, Philip A; Spencer, Jon E; Faulds, James E; House, P Kyle

    2008-09-19

    Polyak et al. (Reports, 7 March 2008, p. 1377) reported that development of the western Grand Canyon began about 17 million years ago. However, their conclusion is based on an inappropriate conflation of Plio-Quaternary incision rates and longer-term rates derived from sites outside the Grand Canyon. Water-table declines at these sites were more likely related to local base-level changes and Miocene regional extensional tectonics.

  14. Framing Effects are Robust to Linguistic Disambiguation: A Critical Test of Contemporary Theory

    OpenAIRE

    Chick, Christina F.; Reyna, Valerie F.; Corbin, Jonathan C.

    2015-01-01

    Theoretical accounts of risky choice framing effects assume that decision makers interpret framing options as extensionally equivalent, such that if 600 lives are at stake, saving 200 implies that 400 die. However, many scholars have argued that framing effects are caused, instead, by filling in pragmatically implied information. This linguistic ambiguity hypothesis is grounded in neo-Gricean pragmatics, information leakage, and schema theory. In two experiments, we conducted a critical test ...

  15. Stratigraphy of the Volcanic Products Around Nemrut Caldera: Implications for Reconstruction of the Caldera Formation

    OpenAIRE

    KARAOĞLU, Özgür; ÖZDEMİR, Yavuz; TOLLUOĞLU, A. ÜMİT

    2005-01-01

    The volcanological development of the Nemrut stratovolcano, located near the southwestern tip of Lake Van in eastern Turkey, is subdivided into three stages: pre-caldera, post-caldera and late stages. Two ignimbrite flows have been recognized in the pre-caldera stage. The earlier of the two occurred after basaltic lavas formed along extensional fissures. The latter, which forms the main subject of this paper, was a major flow associated with the development of the Nemrut caldera. The pyroclas...

  16. Negative Normal Stress Elasticity of Emulsions of Viscous Drops at Finite Inertia

    Science.gov (United States)

    Li, Xiaoyi; Sarkar, Kausik

    2005-12-01

    The relation between the normal stress and the imposed strain for a Newtonian emulsion in an oscillating extensional flow is computed at finite Reynolds numbers using numerically simulated drop geometry. The interfacial stress was determined using Batchelor’s formalism. In the presence of inertia, the phase between the stress and the strain deviates from Stokes’s flow, and leads to a negative elastic modulus at small frequencies. The results are explained by a mass-spring-dashpot model.

  17. Propuesta de metodología para la calificación bio-ambiental de espacios verdes mediante coeficientes ecofisiológicos

    OpenAIRE

    Carrieri, Sergio A.; Codina, Ramón A.; Manzano, Enrique R.; Videla, Eugenia; Vespa, María Juliana; Kocsis, Cecilia Adriana; Ferro Malecki, Marianela; Fioretti, Sonia B.

    2009-01-01

    Uno de los mayores problemas que enfrentan las urbes modernas es su crecimiento horizontal en base a cemento y asfalto, cubriendo grandes extensiones. Su resultado es un importante incremento de la temperatura llamado efecto "isla de calor", aspecto de particular importancia en años venideros por el creciente calentamiento global, a lo cual se añade la contaminación por gases y partículas. Las ...

  18. Métodos y procesos para sistemas distribuidos : Experiencias

    OpenAIRE

    Pesado, Patricia Mabel; Thomas, Pablo Javier; Bertone, Rodolfo Alfredo; Ramón, Hugo Dionisio; Pasini, Ariel C.; Ibañez, Eduardo; Estrebou, César Armando; Marrero, Luciano; Delía, Lisandro Nahuel; Galdámez, Nicolás; Aguirre, Verónica; Ripodas, Alejandra

    2013-01-01

    Se presenta la continuidad de la línea de investigación y desarrollo, que tiene por objeto estudiar temas relacionados con aspectos de Ingeniería de Software orientados al desarrollo e implementación de proyectos concretos de Sistemas Distribuidos, en particular Sistemas Web, Sistemas Sensibles al Contexto y aplicaciones de E-Goverment, considerando las extensiones necesarias en las metodologías y herramientas clásicas.

  19. Etude volcano-tectonique de la zone de Divergence Nord Tanzanienne (Terminaison Sud du Rift Kenyan).
    Caractérisation pétrologique et géochimique du volcanisme récent (8 Ma – Actuel) et du manteau source.
    Contraintes de mise en place.

    OpenAIRE

    Nonnotte, Philippe

    2007-01-01

    The East African Rift System (EARS) is the best example worldwide of an active magmatic rift. It extends over more than 3500 km from the Afar province to the Mozambican Gulf, cutting through the Ethiopian and East Africa elevated plateaus that are the topographic expression of one or several Cenozoic mantle plumes beneath this part of Africa. Extensional strain initited along the eastern magmatic branch of the EARS at ca. 30 My in the Afar, and then propagated southwards by linkage of discret...

  20. Lithospheric mantle deformation in the Yerer-Tullu Wellel Volcanotectonic Lineament: A study of peridotite xenoliths

    Science.gov (United States)

    Trestrail, K. R.; Rooney, T. O.

    2014-12-01

    Although a great deal is known about crustal extensional processes in the East African Rift System (EARS), questions remain as to the impact of extension on the continental lithospheric mantle. The northernmost portion of the EARS is the Main Ethiopian Rift (MER), which is divided into three sectors: the Northern, (NMER), Central (CMER), and the Southern Main Ethiopian Rift (SMER). The NMER-CMER transition coincides with the Yerer-Tullu Wellel volcanotectonic lineament (YTVL), and may represent a terrain boundary along which extension was directed during the Cenozoic. Here we present petrographic data from peridotite xenoliths contained within ~6 Ma lavas recovered along the western portion of the YTVL near Nekempte, Ethiopia to examine the characteristics of the lithospheric mantle, and how peridotite has responded to extensional strain. Our preliminary results show that the Nekempte xenoliths are deformed spinel-bearing lherzolites, which previous studies have constrained to the spinel lherzolites field at 1.1 GPa in the lithospheric mantle. Petrographic examination of these xenoliths reveals two generations of crystals. These generations are defined by both size and texture; the first generation (coarse crystals) being up to 4 mm in diameter and the second generation (fine crystals) being less than 1 mm in diameter. The samples contain two generations of olivine (Ol I and Ol II) and orthopyroxene (Opx I and Opx II), one generation of clinopyroxene (Cpx I), spinel (Spl I), amphibole (Amp), and many fluid inclusion trails. We compare these xenoliths to samples from Injibara, Lake Tana Province, approximately 200 km north of Nekempte on the Ethiopian Plateau, a region with less focused extensional strain. Xenoliths from Injibara are also spinel-bearing lherzolites, however they exhibit less strain and metasomatic textures in comparison to xenoliths from along the YTVL. Based on the petrographic and textural analyses performed, we propose that the larger scale

  1. Tectonic model of the 2016, Central Apennines earthquake sequence: implications for seismogenic source identification

    Science.gov (United States)

    Bonini, Lorenzo; Maesano, Francesco Emanuele; Basili, Roberto; Burrato, Pierfrancesco; Fracassi, Umberto; Tiberti, Mara Monica; Vannoli, Paola; Valensise, Gianluca

    2017-04-01

    On 24 August 2016 a Mw 6.0 earthquake marked the beginning of a severe seismic sequence that struck Central Italy. This shock was followed by a Mw 5.9 on 26 October, by a Mw 6.5 on 30 October, by two Mw 5.4 aftershocks and by over 30,000 smaller shocks. Based on the widespread occurrence of surface breaks the majority of workers agreed that this sequence was caused by a widely-recognized system of Quaternary normal faults crossing the region, namely the Monti della Laga - Monte Vettore fault system. In this study we use surface and subsurface geological data, coupled with distributions of relocated seismicity and InSAR evidence of ground displacement, to show that the earthquake sequence was caused by the reactivation at depth of tectonic structures inherited from older tectonic phases combined with sympathetic slip along shallow ruptures. In particular we maintain that an inherited thrust fault is the most likely source of the 30 October, Mw 6.5 earthquake, the largest of the sequence. We also propose that the sequence involved slip along a normal fault partially located in the footwall of such thrust, and that this was the source of the 24 August, Mw 6.0 event. This latter fault partially reactivated the thrust in an extensional sense. The 26 October, Mw 5.9 event was caused by the extensional reactivation of an eastern portion of the same thrust; together with the 24 August earthquake this event triggered the reactivation of the whole thrust with extensional kinematics, ultimately leading to the Mw 6.5 shock. The 2016 sequence illuminates several aspects of the seismotectonics of the Central Apennines, casting doubts on a number of hypotheses that were put forward based exclusively on observations of exposed brittle structures. It also shows the key role of reactivated inherited structures as potential sources for large earthquakes, in addition to the activation of younger extensional fault systems.

  2. What determines sclerobiont colonization on marine mollusk shells?

    Science.gov (United States)

    Ochi Agostini, Vanessa; Ritter, Matias do Nascimento; José Macedo, Alexandre; Muxagata, Erik; Erthal, Fernando

    2017-01-01

    Empty mollusk shells may act as colonization surfaces for sclerobionts depending on the physical, chemical, and biological attributes of the shells. However, the main factors that can affect the establishment of an organism on hard substrates and the colonization patterns on modern and time-averaged shells remain unclear. Using experimental and field approaches, we compared sclerobiont (i.e., bacteria and invertebrate) colonization patterns on the exposed shells (internal and external sides) of three bivalve species (Anadara brasiliana, Mactra isabelleana, and Amarilladesma mactroides) with different external shell textures. In addition, we evaluated the influence of the host characteristics (mode of life, body size, color alteration, external and internal ornamentation and mineralogy) of sclerobionts on dead mollusk shells (bivalve and gastropod) collected from the Southern Brazilian coast. Finally, we compared field observations with experiments to evaluate how the biological signs of the present-day invertebrate settlements are preserved in molluscan death assemblages (incipient fossil record) in a subtropical shallow coastal setting. The results enhance our understanding of sclerobiont colonization over modern and paleoecology perspectives. The data suggest that sclerobiont settlement is enhanced by (i) high(er) biofilm bacteria density, which is more attracted to surfaces with high ornamentation; (ii) heterogeneous internal and external shell surface; (iii) shallow infaunal or attached epifaunal life modes; (iv) colorful or post-mortem oxidized shell surfaces; (v) shell size (1,351 mm2); and (vi) calcitic mineralogy. Although the biofilm bacteria density, shell size, and texture are considered the most important factors, the effects of other covarying attributes should also be considered. We observed a similar pattern of sclerobiont colonization frequency over modern and paleoecology perspectives, with an increase of invertebrates occurring on textured bivalve

  3. Pseudo-nitzschia species on the Catalan coast: characterization and contribution to the current knowledge of the distribution of this genus in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    Sonia Quijano-Scheggia

    2010-04-01

    Full Text Available Proliferations of the genus Pseudo-nitzschia recur along the Catalan coast (NW Mediterranean throughout the year. The establishment of 58 clonal cultures facilitated morphological studies with scanning electron microscopy (SEM and ITS 5.8S rDNA sequence characterization. Moreover, strains of each species were examined with respect to sexual compatibility and toxicity. The results of the morphological and phylogenetic studies confirmed nine species of the genus Pseudo-nitzschia: P. brasiliana, P. calliantha, P. delicatissima clade A/del 2, P. arenysensis, P. fraudulenta, P. galaxiae, P. linea, P. multistriata and P. pungens clade I. Moreover, two Pseudo-nitzschia species, P. caciantha and P. cf mannii, could only be identified following SEM analysis of their morphology. None of the cultured strains of Pseudo-nitzschia analyzed produced domoic acid in amounts above the limit of detection. The current distributions of the Pseudo-nitzschia species in the Mediterranean Sea were plotted on maps, which led to the following observations: i diversity within this genus is much greater than previously considered, ii some species have a broad distribution (e.g. P. calliantha, iii whereas the distribution of others is narrowly restricted (e.g. P. pungens clade I. Moreover, this study reports the first detection of P. linea in the Mediterranean Sea and is the first description of P. galaxiae and P. cf mannii along the Catalan coast. Morphological studies coupled with molecular biological characterization, mating tests and biogeographic distribution analyses provide a critical theoretical basis for testing and/or implementing the current phylogenetic framework in the genus Pseudo-nitzschia.

  4. Spatiotemporal appraisal of TBT contamination and imposex along a tropical bay (Todos os Santos Bay, Brazil).

    Science.gov (United States)

    Artifon, Vanda; Castro, Ítalo Braga; Fillmann, Gilberto

    2016-08-01

    A spatiotemporal evaluation of butyltin contamination was performed between 2010 and 2012 along Todos os Santos Bay (Northeast Brazil) using surface sediments, bivalve tissues (Anomalocardia brasiliana and Mytella guyanensis), and imposex occurrence (Stramonita rustica). The spatial study detected high tributyltin (TBT) levels (maximum values of 262 ng Sn g (-1) - 21,833 ng Sn g(-1) of total organic carbon - for surface sediments and 421 ng Sn g(-1) for bivalve tissues) in the innermost part of the bay. The TBT levels detected in M. guyanensis tissues might cause human health risk since local population consumes these organisms. These high concentrations observed in the bivalves might result in ingestions higher than the safe limits established by European Food Safety Authority (250 ng TBT kg(-1) day(-1)). Considering the temporal evaluation, no difference (p > 0.05) was observed between TBT concentrations in sediments obtained during the two sampling campaigns (2010/2011 and 2012). However, the increasing predominance of TBT metabolites (butyltin degradation index (BDI) >1) in more recent sediments indicates further degradation of old TBT inputs. In spite of that, recent inputs are still evident at this region. Nevertheless, a reduction of imposex parameters in S. rustica over the last decade suggests an overall decline in the TBT contamination, at least in the outermost and possible less impacted region of the bay. The TBT contamination is probably reducing due to the national and international legislative restrictions on the use of TBT as antifouling biocide. The contamination levels, however, are still relevant especially in the inner part of Todos os Santos Bay since they are above those that are likely to cause toxicity to the biota.

  5. Monitoring ecotoxicological and Environmental Testing Using with Biosurfactants Evaluation of Zone Water Quality Port | Monitoramento de testes ecotoxicológicos e ambientais Usando com biossurfactantes avaliação do porto de qualidade da água da zona

    Directory of Open Access Journals (Sweden)

    Itala Gabriela Sobral dos Santos

    2016-10-01

    Full Text Available Biosurfactants can be used in environmental pollution control systems for oil spill and its derivatives, since they increase the bioavailability of contaminants by reducing the surface tension of water. The mollusk Anomalocardia brasiliana is a species that inhabits areas with little suspended material. The aim was to test the tolerance concentration and the median lethal concentration (LC50 for a period of 96h through survival. The experiment was conducted at UFRPE, and the biosurfactant produced the root Candida lipolytica, having an industrial waste as a source of carbon, plus mineral medium. The animals were not fed for 24 hr prior to the experiment. It was performed six treatments (1:10, 1:20, 1:40, 1:80 and 1: 160 in three replicates, with the density of 2.5 individual / Litre and subjected to constant aeration at a temperature of 26 ± 0 5 ° C and salinity 26. It follows that the treatments 1 (1:10 and 2 (1:20 gave a survival 76.18%, however treatments 3 (95.23% and 4 (95 83% were higher and treating with 5 to 100%. The LC50 estimated for the biosurfactant tested was 0.222 or 1: 4.5. The compound is lethal to the test organism used in dilutions being suggested further experiments with dilutions from 1: 05 to 1:20, to better estimate of LC50 for the same species. Thus, a better understanding of the lethal concentration in organisms representing different trophic levels brings positive results to optimize the procedures in environmental monitoring in port areas.

  6. Plantas medicinais usadas para tratamentos dermatológicos, em comunidades da Bacia do Alto Paraguai, Mato Grosso

    Directory of Open Access Journals (Sweden)

    M. Macedo

    Full Text Available O uso de plantas medicinais no Brasil e em especial no Estado de Mato Grosso vem sendo registrado em suas comunidades rurais e tradicionais. Este trabalho visa identificar plantas com potencial dermatológico utilizada pelas comunidades: quilombolas, ribeirinhas, rurais e tradicionais dos municípios de Barão de Melgaço, Nossa Senhora do Livramento, Poconé e Santo Antônio de Leverger. Fez-se a coleta de material botânico fértil e levantamento sobre o uso desses vegetais com a população local. Este material encontra-se identificado e depositado em Coleção de Referência de Plantas Medicinais no UFMT, Herbário Central. Registraram-se 36 espécies utilizadas no tratamento de doenças como afecções, feridas e úlceras, erisipelas, herpes labial e verrugas. Destacam-se espécies como: Astronium fraxinifolium Schott.; Bixa orellana L.; Brosimum gaudichaudii Tréc.; Cassia grandis Lf.; Heliotropium indicum L.; Jacaranda brasiliana (Lam. Pers.; Macrosiphonia velame (St. Hil. Mull. Arg.; Pistia stratiotes L.; Senna alatal. Roxb., entre outras. Estes vegetais são freqüentemente usados na forma de banhos e chás. O órgão vegetal mais utilizado foi as folhas, seguido de cascas do caule, frutos, óleo, raiz, planta inteira, seiva e sementes. O avanço da fronteira agropecuária nesse Estado é constante preocupação dos botânicos e das comunidades que ao longo das décadas usufruem desse potencial medicinal.

  7. New constraints on the timing of flexural deformation along the northern Australian margin: Implications for arc-continent collision and the development of the Timor Trough

    Science.gov (United States)

    Saqab, Muhammad Mudasar; Bourget, Julien; Trotter, Julie; Keep, Myra

    2017-01-01

    Numerous extensional faults offset the passive margin strata of the northern Bonaparte Basin. This extensional deformation has been attributed to lithospheric flexure of the descending Australian Plate, in an overall convergence setting. Here we use an extensive 2D and 3D seismic dataset calibrated with well biostratigraphy and strontium (Sr) isotope age data to constrain the timing of deformation along the northern Australian margin during the Neogene. Analysis of fault throw and differential thickness variations give new insights on the propagation and slip history of the faults. Along-dip throw profiles exhibit 'D' shape distributions, skewed towards the top. Positive throw gradients above the throw maxima, coinciding with intervals of growth strata, indicate multiphase fault activity. Results indicate that post-rift extensional deformation initiated during the latest Miocene (ca. 6 Ma). The development of the modern Timor Trough (as a foreland basin) and Cartier Trough also commenced during this period. A second episode of increased tectonic activity occurred around the Pliocene-Quaternary boundary (ca. 3 Ma), and the deformation continued intermittently to the present-day. These new results are in agreement with the timing of initiation of collision between the Australian Plate and the Banda Arc and uplift of the Timor Island, recently derived from stratigraphic analysis in Timor. These regional tectonic events have profoundly affected the paleogeography of the Timor Sea and may explain major changes in oceanic circulation and climate during the Neogene.

  8. Tectonic Models for the Lake Vostok Region: Evidence for a major Suture Zone within East Antarctica

    Science.gov (United States)

    Studinger, M.; Karner, G. D.; Bell, R. E.; Levin, V.; Raymond, C. A.; Tikku, A. A.; Lerner-Lam, A.

    2001-12-01

    East Antarctica, roughly the size of the conterminous United States, remains the largest unexplored part of the Earth's crust. Existing tectonic models are mostly derived from the geological record preserved in the sparse rock outcrops along the perimeter of the continent. New aerogeophysical data, acquired during the 2000/01 field season over Lake Vostok represents the first comprehensive geophysical data in this region. A range of tectonic models has been tested in order to match the observed and predicted aerogeophysical data. A simple boundary between two different crustal blocks with different thickness and density, isostatically balanced, fails to match the long wavelength signature and amplitude of the observed gravity. Similarly, a simple extensional model does not fit the observed long wavelength trends in the gravity. In order to match the characteristic anomalies along the profiles we constructed a thrust model involving a former continental margin on one side. This model explains the typical asymmetric, dipolar gravity signature of suture zones. A small extensional basin beneath Lake Vostok,is needed to match the short wavelength gravity low, modulating the main trend. This small basin was likely created during a later phase of weak extensional reactivation. Modeling of composite receiver functions supports the idea of two different types of crust on top of each other beneath the recording site. Our newly discovered boundary in East Antarctica, its possible extension towards the Queen Mary Coast and its relation to major structures in Australia like the Albany-Fraser belt will be discussed in our presentation.

  9. Basin analysis in the Southern Tethyan margin: Facies sequences, stratal pattern and subsidence history highlight extension-to-inversion processes in the Cretaceous Panormide carbonate platform (NW Sicily)

    Science.gov (United States)

    Basilone, Luca; Sulli, Attilio

    2018-01-01

    In the Mediterranean, the South-Tethys paleomargin experienced polyphased tectonic episodes and paleoenvironmental perturbations during Mesozoic time. The Cretaceous shallow-water carbonate successions of the Panormide platform, outcropping in the northern edge of the Palermo Mountains (NW Sicily), were studied by integrating facies and stratal pattern with backstripping analysis to recognize the tectonics vs. carbonate sedimentation interaction. The features of the Requienid limestone, including geometric configuration, facies sequence, lithological changes and significance of the top-unconformity, highlight that at the end of the Lower Cretaceous the carbonate platform was tectonically dismembered in various rotating fault-blocks. The variable trends of the subsidence curves testify to different responses, both uplift and downthrow, of various platform-blocks impacted by extensional tectonics. Physical stratigraphic and facies analysis of the Rudistid limestone highlight that during the Upper Cretaceous the previously carbonate platform faulted-blocks were subjected to vertical movements in the direction opposite to the displacement produced by the extensional tectonics, indicating a positive tectonic inversion. Comparisons with other sectors of the Southern Tethyan and Adria paleomargins indicate that during the Cretaceous these areas underwent the same extensional and compressional stages occurring in the Panormide carbonate platform, suggesting a regional scale significance, in time and kinematics, for these tectonic events.

  10. Geological structure and evolution of Majorca: Implications for the origin of the Western Mediterranean

    Science.gov (United States)

    Sàbat, Francesc; Gelabert, Bernadí; Rodríguez-Perea, Antonio; Giménez, Jordi

    2011-09-01

    The island of Majorca forms part of the NE-SW continental Balearic Promontory, which is surrounded by continental and oceanic extensional basins. Majorca has a basin and range physiography mainly resulting from Late Neogene extension. The basins and ranges strike NE-SW. The structure of the ranges consists of thrust faults and associated folds involving Mesozoic series. Paleogene series are also involved in the compressional structures located in the southeast, whereas a stratigraphic hiatus embracing Late Cretaceous and Paleogene is present in the rest of the island. The age of syncompressive rocks and sediments is Chattian to Aquitanian in the SE Llevant Ranges, Aquitanian to Burdigalian in the Central Ranges and Burdigalian to Langhian in the NW Tramuntana Range. Thus compressive deformation progressed from southeast to northwest. The thrust fault hangingwall displacement is to the northwest and shortening is large (44%). Seismic reflection sections reveal the presence of compressive structures in the substratum of the basins. Moreover, normal faults due to WNW-ESE extension occurred during the Serravallian and Tortonian, producing additional subsidence in the basins. Minor compression could have occurred since the onset of the Pleistocene. Majorca was shortened when the extensional basins surrounding the island originated. Available models for the origin and evolution of extensional basins of the Western Mediterranean do not consider the structure observed in Majorca.

  11. Elasticity and Extensibility Determine Printability and Spinnability of Polymer Solutions

    Science.gov (United States)

    Dinic, Jelena; Jimenez, Leidy; Sharma, Vivek

    Many advanced manufacturing technologies like inkjet and 3D printing, nano-fiber spinning involve complex free-surface flows, and the formation of columnar necks that undergo spontaneous capillary-driven thinning and pinch-off. The progressive self-thinning of neck is often characterized by self-similar profiles and scaling laws that depend on the relative magnitude of capillary, inertial and viscous stresses for simple (Newtonian and inelastic) fluids. Stream-wise velocity gradients that arise within the thinning columnar neck create an extensional flow field that can orient and stretch macromolecules, contributing extra elastic stresses and extensional viscosity that change thinning and pinch-off dynamics for polymeric complex fluids. Characterizing the filament thinning and break-up kinetics in jetting, dripping and stretching liquid bridge provides invaluable insight into the interplay of elastic, viscous, capillary and inertial stresses relevant for these applications. We elucidate how polymer composition, flexibility and molecular weight determine the thinning and pinch-off kinetics in our experiments. Both effective relaxation time and transient extensional viscosity are found to be strongly concentration dependent even for dilute solutions.

  12. Parallel Extension Tectonics (PET): Early Cretaceous tectonic extension of the Eastern Eurasian continent

    Science.gov (United States)

    Liu, Junlai; Ji, Mo; Ni, Jinlong; Guan, Huimei; Shen, Liang

    2017-04-01

    The present study reports progress of our recent studies on the extensional structures in eastern North China craton and contiguous areas. We focus on characterizing and timing the formation/exhumation of the extensional structures, the Liaonan metamorphic core complex (mcc) and the Dayingzi basin from the Liaodong peninsula, the Queshan mcc, the Wulian mcc and the Zhucheng basin from the Jiaodong peninsula, and the Dashan magmatic dome within the Sulu orogenic belt. Magmatic rocks (either volcanic or plutonic) are ubiquitous in association with the tectonic extension (both syn- and post-kinematic). Evidence for crustal-mantle magma mixing are popular in many syn-kinematic intrusions. Geochemical analysis reveals that basaltic, andesitic to rhyolitic magmas were generated during the tectonic extension. Sr-Nd isotopes of the syn-kinematic magmatic rocks suggest that they were dominantly originated from ancient or juvenile crust partly with mantle signatures. Post-kinematic mafic intrusions with ages from ca. 121 Ma to Cenozoic, however, are of characteristic oceanic island basalts (OIB)-like trace element distribution patterns and relatively depleted radiogenic Sr-Nd isotope compositions. Integrated studies on the extensional structures, geochemical signatures of syn-kinematic magmatic rocks (mostly of granitic) and the tectono-magmatic relationships suggest that extension of the crust and the mantle lithosphere triggered the magmatisms from both the crust and the mantle. The Early Cretaceous tectono-magmatic evolution of the eastern Eurasian continent is governed by the PET in which the tectonic processes is subdivided into two stages, i.e. an early stage of tectonic extension, and a late stage of collapse of the extended lithosphere and transformation of lithospheric mantle. During the early stage, tectonic extension of the lithosphere led to detachment faulting in both the crust and mantle, resulted in the loss of some of the subcontinental roots, gave rise to

  13. Cenozoic Extension of the Southern Menderes Massif along the Kayabuku Shear Zone, Western Anatolia Extended Terrane, Turkey

    Science.gov (United States)

    Diniz, E.; Cemen, I.; Catlos, E. J.; Konak, N.; Goncuoglu, C. M.; Kohn, M. J.; Baker, C.; Hancer, M.

    2006-12-01

    Four major low angle extensional shear zones are located in the Menderes massif of the Western Anatolia Extended Terrane in western Turkey. The shear zones are, from north to south, Simav, Alasehir, Buyuk Menderes and Kayabuku (Selimiye) shear zones. We have conducted a detailed field oriented study to determine the role of the Kayabuku (Selimiye) shear zone in the Cenozoic extensional evolution of the Menderes massif. The south-dipping Kayabuku (Selimiye) shear zone of the southern Menderes massif contains well- developed mesoscopic and microscopic shear sense indicators, and separates orthogneiss and augengneiss in its footwall from schist and marble rock units in its hanging wall. Within the shear zone, the average attitude of the foliation planes between the towns of Milas and Yatagan is measured as N86W/50°S. The shear zone shows two ductile sense of shearing; 1) top to the north and 2) top to the south which overprinted the former one. Many thin sections also show top to the south brittle shear sense indicators overprinting the ductile shear sense indicators. The trend of the ductile shear sense indicators, such as stretching lineations, range from N10E to N30E indicating that they are parallel to the shear sense indicators measured along the Simav shear zone of the northern and, Alasehir and Buyuk Menderes shear zones of the central Menderes massif. This suggests to us that the Cenozoic extension which was initiated in Oligocene by the processes of Orogenic Collapse effected the Kayabuku (Selimiye) shear zone. The hanging wall of the Kayabuku shear zone is also locally brittely deformed by a south-dipping normal fault zone, discontinuously exposed between the schist and marble units. The fault zone suggests that the hanging wall of the shear zone has been brittely deformed during the extensional exhumation of the southern Menderes massif. Our field observations and microtectonic studies suggest that the rocks within the Kayabuku (Selimiye) shear zone gained

  14. The Dead Sea Rift, a key to the tectonic link between the NeoTethys closure of and opening of the Red Sea

    Science.gov (United States)

    Mart, Y.

    2009-04-01

    The closure of the central NeoTethys Ocean took place progressively as the subduction of the oceanic lithosphere off Africa-Arabia gradually changed into collision, advancing southeastwards along the Zagros front since the early Miocene. That subduction-collision is contemporaneous with the opening of the Red Sea, and structural modeling suggested that the oblique convergence along frontal Arabia formed extensional stresses in the Arabia-Africa plate which matured in time to become the tectonic plate boundaries of the Gulf of Aden and the Red Sea (Bellahsen et al., 2003). However such marine basins are not known to occur along subducting plates, and the contemporaneity of the Zagros collision and the Red Sea extension could have been tectonically unrelated. Fortuitously the key to the tectonic linkage between the opening of the Red Sea and the closure of the NeoTethys can be found in the Dead Sea Rift. The tectonics of the Dead Sea Rift has been debated for decades to be interpreted either as a transform fault or an extensional rift, both extending from the northern Red Sea. The transform fault interpretation requires the Dead Sea structure to be contemporaneous with the Red Sea, whereas if it is an extensional rift, its structural development should be subsequent to that of the the Suez Rift. It is well established that the Red Sea and its extension in the Suez Rift developed during the Miocene. However, the reconstruction of the Miocene river drainage of the Levant shows that large rivers flowed then from NW Arabia to the Mediterranean, predating the Dead Sea Rift. This sequence of events sets the structural evolution of the dead Sea Rift to the Plio-Quaternary. The Rift is thus contemporaneous with the termination of the tectonic activity of the Gulf of Suez, indicating a clockwise rotation of the regional stress field in the last 5 Ma. These observation suggest that the extensional stresses caused by the gradual change from subduction to collision along the

  15. Neogene tectonic evolution of the Gulf of Hammamet area, Northeast Tunisia offshore

    Science.gov (United States)

    Brahim, Ghada Ben; Brahim, Noureddine; Turki, Faiçal

    2013-05-01

    This paper discusses the Neogene tectonic evolution of the Tunisia offshore Gulf of Hammamet basin. Based on seismic and well data, this basin was created during the Miocene and is currently trending NE-SW. During the Neogene, the study area was affected by geodynamic interactions controlled simultaneously by convergence of the Eurasia and Africa plates and the opening of the Atlantic Ocean. These interactions generated compressive and extensional regimes which led to a variety of structures and basin inversions. The middle Miocene extensional regime created horst and graben structures (e.g. the Halk El Menzel graben). The two major compressive phases of the Tortonian and post Villafranchian age created different structures such as Ain Zaghouan and Fushia structures and the Jriba trough, and led to the reactivation of the old normal faults as reverse faults. During the Plio-Pleistocene and the Quaternary times, the Gulf of Hammamet was affected by an extensional regime related to the Siculo-Tunisian rift, which led to the development in the area of several sedimentary basins and new normal fault patterns. The Gulf of Hammamet shows several basins ranging in age from the Tortonian to the Quaternary, which display different structural and stratigraphic histories. Two main groups of sedimentary basins have been recognized. The first group has Tortonian-Messinian sedimentary fill, while the second group is largely dominated by Plio-Quaternary sediments. The shortening during the Tortonian and post Villafranchian times has led to the tectonic inversion of these basins. This shortening could be correlated to the Europe-Africa collision. Despite the large number of hydrocarbon discoveries, the Gulf of Hammamet remains under-explored, in particular at deeper levels. This study aims to guide future exploration and to highlight some new play concepts.

  16. New models for Paleoproterozoic orogenesis in the Cheyenne belt region: Evidence from the geology and U-Pb geochronology of the Big Creek Gneiss, southeastern Wyoming

    Science.gov (United States)

    Jones, D.S.; Snoke, A.W.; Premo, W.R.; Chamberlain, K.R.

    2010-01-01

    The disputed age of the deep crust of the Colorado Province is central to hypotheses for Paleoproterozoic crustal growth in the region. We studied the high-grade Big Creek Gneiss, southeastern Wyoming, as a potential exposure of pre-1780 Ma basement rocks. New geologic mapping and U-Pb geochronological data indicate that the Big Creek Gneiss exposes a deeper, but coeval, level of the Green Mountain arc relative to the predominantly supracrustal section to the west. The Big Creek Gneiss is composed of: supracrustal rocks; a ca. 1780 Ma Green Mountain arc-correlative, bimodal intrusive suite; a ca. 1763 Ma extensional(?) bimodal intrusive suite; and widespread ca. 1630 Ma pegmatitic leucogranite. The mafic member of the younger bimodal suite is documented here for the first time. U-Pb zircon ages from migmatite leucosomes indicate penetrative deformation of the Big Creek Gneiss at ca. 1750 Ma. We find that the postarc intrusive suite is mantle-involved, implying a second period of crustal growth. Shortening postdates arc magmatism by ~20 m.y., implying that termination of arc magmatism and accretion were separate events. Finally, criteria previously used to constrain the polarity of subduction for the Green Mountain arc are not reliable. We propose two competing models: (1) southward-dipping Green Mountain arc subduction (present coordinates), with slab breakoff-related magmatism following arc accretion; or (2) northward-dipping subduction, with extensional postarc magmatism. In both models, high-temperature deformation coincides with accretion along the Cheyenne belt, and extensional magmatism is an important component of crustal growth. We prefer the northward-dipping subduction model because it can be better integrated with regional tectonic events and published isotopic compositions of the igneous rocks. ?? 2010 Geological Society of America.

  17. Context recognition for a hyperintensional inference machine

    Science.gov (United States)

    Duží, Marie; Fait, Michal; Menšík, Marek

    2017-07-01

    The goal of this paper is to introduce the algorithm of context recognition in the functional programming language TIL-Script, which is a necessary condition for the implementation of the TIL-Script inference machine. The TIL-Script language is an operationally isomorphic syntactic variant of Tichý's Transparent Intensional Logic (TIL). From the formal point of view, TIL is a hyperintensional, partial, typed λ-calculus with procedural semantics. Hyperintensional, because TIL λ-terms denote procedures (defined as TIL constructions) producing set-theoretic functions rather than the functions themselves; partial, because TIL is a logic of partial functions; and typed, because all the entities of TIL ontology, including constructions, receive a type within a ramified hierarchy of types. These features make it possible to distinguish three levels of abstraction at which TIL constructions operate. At the highest hyperintensional level the object to operate on is a construction (though a higher-order construction is needed to present this lower-order construction as an object of predication). At the middle intensional level the object to operate on is the function presented, or constructed, by a construction, while at the lowest extensional level the object to operate on is the value (if any) of the presented function. Thus a necessary condition for the development of an inference machine for the TIL-Script language is recognizing a context in which a construction occurs, namely extensional, intensional and hyperintensional context, in order to determine the type of an argument at which a given inference rule can be properly applied. As a result, our logic does not flout logical rules of extensional logic, which makes it possible to develop a hyperintensional inference machine for the TIL-Script language.

  18. Boundary layer models for calving marine outlet glaciers

    Science.gov (United States)

    Schoof, Christian; Davis, Andrew D.; Popa, Tiberiu V.

    2017-10-01

    We consider the flow of marine-terminating outlet glaciers that are laterally confined in a channel of prescribed width. In that case, the drag exerted by the channel side walls on a floating ice shelf can reduce extensional stress at the grounding line. If ice flux through the grounding line increases with both ice thickness and extensional stress, then a longer shelf can reduce ice flux by decreasing extensional stress. Consequently, calving has an effect on flux through the grounding line by regulating the length of the shelf. In the absence of a shelf, it plays a similar role by controlling the above-flotation height of the calving cliff. Using two calving laws, one due to Nick et al. (2010) based on a model for crevasse propagation due to hydrofracture and the other simply asserting that calving occurs where the glacier ice becomes afloat, we pose and analyse a flowline model for a marine-terminating glacier by two methods: direct numerical solution and matched asymptotic expansions. The latter leads to a boundary layer formulation that predicts flux through the grounding line as a function of depth to bedrock, channel width, basal drag coefficient, and a calving parameter. By contrast with unbuttressed marine ice sheets, we find that flux can decrease with increasing depth to bedrock at the grounding line, reversing the usual stability criterion for steady grounding line location. Stable steady states can then have grounding lines located on retrograde slopes. We show how this anomalous behaviour relates to the strength of lateral versus basal drag on the grounded portion of the glacier and to the specifics of the calving law used.

  19. Rifting and reactivation of a Cretaceous structural belt at the northern margin of the South China Sea

    Science.gov (United States)

    Nanni, Ugo; Pubellier, Manuel; Chan, Lung Sang; Sewell, Roderick J.

    2017-04-01

    The Tiu Tang Lung Fault, Hong Kong Special Administrative Region - China, is located on the northern stretched continental margin of the South China Sea. Along this fault, Middle Jurassic volcanic rocks of the Tai Mo Shan Formation are tectonically juxtaposed on Lower Cretaceous sedimentary rocks of the Pat Sin Leng Formation. Both extensional detachments and compressional features are observed and various genetic strain configurations are proposed for the Tiu Tang Lung Fault with implications for understanding the dynamics of the pre-South China Sea rifting during the Cretaceous. We have identified tilted bedding planes in the continental deposits of the Pat Sin Leng Formation which can be related to Early Cretaceous syn-extensional deposition. A mid-Cretaceous penetrative top-to-the-south to top-to-the-west shear fabric is also observed and serves as an indicator of the strain pattern. This deformation is expressed by cleavages, schistosity, S/C fabrics, kink-folds, phacoids and stretched pebbles at both a macroscopic and microscopic scale. Cleavages and bedding are generally sub-parallel to the local shear orientation. The whole sedimentary pile is crosscut by Cenozoic N70 and N150 normal faults. These constraints, together with previous fission track, seismic and structural data, allow us to reinterpret the kinematics of this domain during syn-orogenic to syn-extensional periods. The observed top-to-the-south thrusting event is coeval with NE-SW strike-slip sinistral fault movement. Subsequent N-S extension can be correlated with South China Sea rifting from Eocene to Oligocene. These observations reveal a polyphase history associated with continental margin inversion which witnessed localized extension on previous compressional structures.

  20. Exhumation of the Deylaman fault trend and its effects on the deformation style of the western Alborz belt in Iran

    Science.gov (United States)

    Hakimi Asiabar, Saeid; Bagheriyan, Siyamak

    2017-07-01

    The Alborz range in northern Iran stretches along the southern coast of the Caspian Sea and finally runs northeast and merges into the Pamir mountains in Afghanistan. Alborz mountain belt is a doubly vergent orogen formed along the northern edge of the Iranian plateau in response to the closure of the Neo-Tethys ocean and continental collision between Arabia and Eurasia. The south Caspian depression—the Alborz basin of Mesozoic age (with W-E trend) in northern Iran—inverted in response to the Arabia-Eurasia collision. Pre-existing extensional faults of the south Caspian-Alborz system preferentially reactivated as contractional faults because of tectonic inversion. These contractional structures tend to run parallel to the trends of pre-existing extensional faults and acquire W and WNW-ESE orientations across the previous accommodation zones that were imposed by the reactivation of adjacent extensional faults with different directions. The NNE to N dipping faults show evidences of reactivation. The Deylaman fault is one of the important faults of western Alborz in Iran and is an example of inversion tectonic style of deformation in the western Alborz mountain range. The Deylaman fault, with an E-W trend, contains three discontinuous fault segments in the area under investigation. These fault segments have evidence of oblique right-lateral reverse motion and links eastward to the dextral Kandavan thrust. The importance of this fault is due to its effect on sedimentation of several rock units from the Jurassic to Neogene in western Alborz; the rock facies on each side of this fault are very different and illustrate different parts of tectonic history.

  1. Thick-skinned tectonics within the intracontinental easternmost Atlas foreland-and-thrust belt (Tunisia): Meso-Cenozoic kinematics and implications for regional geodynamics

    Science.gov (United States)

    Belkhiria, W.; Boussiga, H.; Inoubli, M. H.

    2017-05-01

    The transition zone between western and central Mediterranean domains presents a key area to investigate kinematic interactions within the adjacent orogen systems such as the easternmost Atlas foreland-and-thrust belt. Gravity and seismic data revealed a highly structured basement, characterizing a series of structural highs and lows delimited by high-angle N-S, E-W, and NW-SE extensional faults. This basement architecture is inherited from successive extensional events related to the openings of the Triassic-Early Cretaceous Tethys oceans (i.e., Alpine Tethys, Ligurian Tethys, and Mesogea). Throughout this period, this mosaic of continental blocks significantly controlled the thickness and facies distributions. Early stages of diapirism took place along these basement faults and allowed maximum subsidence in minibasins revealed by the development of growth strata. In response to the Late Cretaceous-Eocene shortenings, these extensional faults have been reactivated as trasnpressional shear zones, giving rise to narrow pop-up structures. In addition, gravity modeling indicates crustal thinning and deep-rooted faults affecting the crust south of the Zaghouan Thrust and along E-W transfer zones. From the late Miocene, a drastic change in the stress regime is attributed to the effect of the adjacent Sicily channel on the study area. This promotes crustal thinning, basin subsidence, and channeling up of mantle-derived helium along lithospheric-scale weak zones. Our results give rise to new insights into the reactivation of inherited weakness zones of southern Tethys margin in response to the complex interaction between African and Eurasian plates accommodated by subduction, rollback, collision, and slab segmentation.

  2. Tectonic evolution of the North Patagonian Andes (41°-44° S) through recognition of syntectonic strata

    Science.gov (United States)

    Echaurren, A.; Folguera, A.; Gianni, G.; Orts, D.; Tassara, A.; Encinas, A.; Giménez, M.; Valencia, V.

    2016-05-01

    The North Patagonian fold-thrust belt (41°-44° S) is characterized by a low topography, reduced crustal thickness and a broad lateral development determined by a broken foreland system in the retroarc zone. This particular structural system has not been fully addressed in terms of the age and mechanisms that built this orogenic segment. Here, new field and seismic evidence of syntectonic strata constrain the timing of the main deformational stages, evaluating the prevailing crustal regime for the different mountain domains through time. Growth strata and progressive unconformities, controlled by extensional or compressive structures, were recognized in volcanic and sedimentary rocks from the cordilleran to the extra-Andean domain. These data were used to construct a balanced cross section, whose deep structure was investigated through a thermomechanical model that characterizes the upper plate rheology. Our results indicate two main compressive stages, interrupted by an extensional relaxation period. The first contractional stage in the mid-Cretaceous inverted Jurassic-Lower Cretaceous half graben systems, reactivating the western Cañadón Asfalto rift border ~ 500 km away from the trench, at a time of arc foreland expansion. For this stage, available thermochronological data reveal forearc cooling episodes, and global tectonic reconstructions indicate mid-ocean ridge collisions against the western edge of an upper plate with rapid trenchward displacement. Widespread synextensional volcanism is recognized throughout the Paleogene during plate reorganization; retroarc Paleocene--Eocene flare up activity is interpreted as product of a slab rollback, and fore-to-retroarc Oligocene slab/asthenospheric derived products as an expression of enhanced extension. The second stage of mountain growth occurred in Miocene time associated with Nazca Plate subduction, reaching nearly the same amplitude than the first compressive stage. Extensional weakening of the upper plate

  3. Boundary layer models for calving marine outlet glaciers

    Directory of Open Access Journals (Sweden)

    C. Schoof

    2017-10-01

    Full Text Available We consider the flow of marine-terminating outlet glaciers that are laterally confined in a channel of prescribed width. In that case, the drag exerted by the channel side walls on a floating ice shelf can reduce extensional stress at the grounding line. If ice flux through the grounding line increases with both ice thickness and extensional stress, then a longer shelf can reduce ice flux by decreasing extensional stress. Consequently, calving has an effect on flux through the grounding line by regulating the length of the shelf. In the absence of a shelf, it plays a similar role by controlling the above-flotation height of the calving cliff. Using two calving laws, one due to Nick et al. (2010 based on a model for crevasse propagation due to hydrofracture and the other simply asserting that calving occurs where the glacier ice becomes afloat, we pose and analyse a flowline model for a marine-terminating glacier by two methods: direct numerical solution and matched asymptotic expansions. The latter leads to a boundary layer formulation that predicts flux through the grounding line as a function of depth to bedrock, channel width, basal drag coefficient, and a calving parameter. By contrast with unbuttressed marine ice sheets, we find that flux can decrease with increasing depth to bedrock at the grounding line, reversing the usual stability criterion for steady grounding line location. Stable steady states can then have grounding lines located on retrograde slopes. We show how this anomalous behaviour relates to the strength of lateral versus basal drag on the grounded portion of the glacier and to the specifics of the calving law used.

  4. An Andean tectonic cycle: From crustal thickening to extension in a thin crust (34°–37°SL

    Directory of Open Access Journals (Sweden)

    Victor A. Ramos

    2014-05-01

    Full Text Available Several orogenic cycles of mountain building and subsequent collapse associated with periods of shallowing and steepening of subduction zones have been recognized in recent years in the Andes. Most of them are characterized by widespread crustal delamination expressed by large calderas and rhyolitic flare-up produced by the injection of hot asthenosphere in the subduction wedge. These processes are related to the increase of the subduction angle during trench roll-back. The Payenia paleoflat-slab, in the southern Central Andes of Argentina and Chile (34°–37°S recorded a complete cycle from crustal thickening and mountain uplift to extensional collapse and normal faulting, which are related to changes in the subduction geometry. The early stages are associated with magmatic expansion and migration, subsequent deformation and broken foreland. New ages and geochemical data show the middle to late Miocene expansion and migration of arc volcanism towards the foreland region was associated with important deformation in the Andean foothills. However, the main difference of this orogenic cycle with the previously described cycles is that the steepening of the oceanic subducted slab is linked to basaltic flooding of large areas in the retroarc under an extensional setting. Crustal delamination is concentrated only in a narrow central belt along the cordilleran axis. The striking differences between the two types of cycles are interpreted to be related to the crustal thickness when steepening the subducting slab. The crustal thickness of the Altiplano is over 60–80 km, whereas Payenia is less than 42 km in the axial part, and near 30 km in the retroarc foothills. The final extensional regime associated with the slab steepening favors the basaltic flooding of more than 8400 km3 in an area larger than 40,000 km2, through 800 central vents and large fissures. These characteristics are unique in the entire present-day Andes.

  5. Miocene progressive forearc extension in the Central Mediterranean

    Science.gov (United States)

    Milia, A.; Valente, A.; Cavuoto, G.; Torrente, M. M.

    2017-07-01

    Miocene extensional sedimentary basins are being increasingly recognized in Central Mediterranean. However the paleogeographic reconstruction of the Paleo-Tyrrhenian during this time span results a difficult task because the subsequent Pliocene-Quaternary backarc opening moved away these older sedimentary basins. Our study outlines principal deformation events recorded by sediments that were deposited within minor basins of the Tyrrhenian Sea region and provides constraints on the duration of these events. The interpretation of seismic profiles, wells, and outcrops data together with a review of the middle-upper Miocene successions permitted us to recognize Miocene third order depositional sequences, reconstruct the fault pattern, and furnish a detailed evolution of the sedimentary basins that preceded the Pliocene-Quaternary Tyrrhenian high stretching. Based on the stratigraphic and tectonic constraints together with the age migration of the depocenters, we reconstructed a detailed paleogeographic evolution of central Mediterranean. Sedimentary basins architecture and fault pattern indicate a system of approximately N-S oriented normal faults and approximately E-W transform faults that were active since the Late Oligocene. Two period of extensional/transtensional tectonics (late Oligocene-Lower Burdigalian and Upper Langhian-Tortonian) were interrupted by a compressional event (late Burdigalian-Lower Langhian). Tacking in account the position of the Miocene volcanic arc (Sardinia), we propose that the coeval sedimentary basins developed in the central Mediterranean as forearc extensional/transtensional basins during the progressive collision with the African plate and before the Tyrrhenian backarc opening. Unlike published late Oligocene-Tortonian reconstructions of the western-central Mediterranean realm that report a linear migration of backarc extension, our results support a geodynamic model characterized by a progressive deformation of the forearc extension

  6. The Red Sea structural architecture assessment based on yield strength spatial variations and Arabian margin preexisting structures

    Science.gov (United States)

    Alotaibi, T.; Furlong, K. P.

    2016-12-01

    Rift initiation and localization might reflect spatial changes in the lithospheric yield strength. However, this does not appear to be the case in the Red Sea extensional system where fission track analysis shows no significant changes in the geothermal gradient prior to the Red Sea rift onset. In contrast, though the whole Red Sea rift initiated 25 Ma ago, its extensional architecture changes dramatically along strike from narrow localized spreading in the south to asymmetrical diffuse extension north of 21° latitude. This onset of diffuse extension has been recorded in the north-western Arabian margin as old as 33 Ma. Such diversity in the extensional style might reflect along strike yield strength variations as a consequence of the geological setting in the Arabian margin. The north-western Arabian basin, which is part of the Arabian margin, bounded by Qiba high from the east, the Arabian shield from the south and the west and Syrian plateau from the north. The basin accommodates part of the Red Sea diffuse extension and has a preexisting structural architecture represented in the Cenozoic failed rift that called Sarhan graben. Our goal is to analyze the current lithospheric yield strength spatial variations along the Red Sea rift and emphasize their relationship with the Arabian margin structural architecture. We hypothesize that the north-western Arabian margin's lithospheric weakness and structural diversity are playing an important role in producing region of diffuse extension by their interaction with the forces applied by far field stresses represented by the New Tethys slab pull. On the other hand, the south-western Arabian margin interacts with the far field stresses as a single strong block in which led to localize the extension in the southern Red Sea. Our work may improve the scientific community understanding for how rifts initiate and evolve over time.

  7. Late Cenozoic extension and crustal doming in the India-Eurasia collision zone: New thermochronologic constraints from the NE Chinese Pamir

    Science.gov (United States)

    Thiede, Rasmus C.; Sobel, Edward R.; Chen, Jie; Schoenbohm, Lindsay M.; Stockli, Daniel F.; Sudo, Masafumi; Strecker, Manfred R.

    2013-06-01

    northward motion of the Pamir indenter with respect to Eurasia has resulted in coeval thrusting, strike-slip faulting, and normal faulting. The eastern Pamir is currently deformed by east-west oriented extension, accompanied by uplift and exhumation of the Kongur Shan (7719 m) and Muztagh Ata (7546 m) gneiss domes. Both domes are an integral part of the footwall of the Kongur Shan extensional fault system (KES), a 250 km long, north-south oriented graben. Why active normal faulting within the Pamir is primarily localized along the KES and not distributed more widely throughout the orogen has remained unclear. In addition, relatively little is known about how deformation has evolved throughout the Cenozoic, despite refined estimates on present-day crustal deformation rates and microseismicity, which indicate where crustal deformation is presently being accommodated. To better constrain the spatiotemporal evolution of faulting along the KES, we present 39 new apatite fission track, zircon U-Th-Sm/He, and 40Ar/39Ar cooling ages from a series of footwall transects along the KES graben shoulder. Combining these data with present-day topographic relief, 1-D thermokinematic and exhumational modeling documents successive stages, rather than synchronous deformation and gneiss dome exhumation. While the exhumation of the Kongur Shan commenced during the late Miocene, extensional processes in the Muztagh Ata massif began earlier and have slowed down since the late Miocene. We present a new model of synorogenic extension suggesting that thermal and density effects associated with a lithospheric tear fault along the eastern margin of the subducting Alai slab localize extensional upper plate deformation along the KES and decouple crustal motion between the central/western Pamir and eastern Pamir/Tarim basin.

  8. Effects of lateral variations of crustal rheology on the occurrence of post-orogenic normal faults: The Alto Tiberina Fault (Northern Apennines, Central Italy)

    Science.gov (United States)

    Pauselli, Cristina; Ranalli, Giorgio

    2017-11-01

    The Northern Apennines (NA) are characterized by formerly compressive structures partly overprinted by subsequent extensional structures. The area of extensional tectonics migrated eastward since the Miocene. The youngest and easternmost major expression of extension is the Alto Tiberina Fault (ATF). We estimate 2D rheological profiles across the NA, and conclude that lateral rheological crustal variations have played an important role in the formation of the ATF and similar previously active faults to the west. Lithospheric delamination and mantle degassing resulted in an easterly-migrating extension-compression boundary, coinciding at present with the ATF, where (i) the thickness of the upper crust brittle layer reaches a maximum; (ii) the critical stress difference required to initiate faulting at the base of the brittle layer is at a minimum; and (iii) the total strengths of both the brittle layer and the whole lithosphere are at a minimum. Although the location of the fault is correlated with lithospheric rheological properties, the rheology by itself does not account for the low dip ( 20°) of the ATF. Two hypotheses are considered: (a) the low dip of the ATF is related to a rotation of the stress tensor at the time of initiation of the fault, caused by a basal shear stress ( 100 MPa) possibly related to corner flow associated with delamination; or (b) the low dip is associated to low values of the friction coefficient (≤ 0.5) coupled with high pore pressures related to mantle degassing. Our results establishing the correlation between crustal rheology and the location of the ATF are relatively robust, as we have examined various possible compositions and rheological parameters. They also provide possible general indications on the mechanisms of localized extension in post-orogenic extensional setting. The hypotheses to account for the low dip of the ATF, on the other hand, are intended simply to suggest possible solutions worthy of further study.

  9. EXPERIMENTAL STUDY OF THERMAL AND STRAIN FIELDS DURING DEFORMATION OF EN ENCHELON FAULTS AND ITS GEOLOGICAL IMPLICATIONS

    Directory of Open Access Journals (Sweden)

    Ma Jin

    2015-09-01

    Full Text Available The article presents results of experimental studies using a bi-axial servo-control system to apply load on samples with extensional and compressional en echelon faults. During the experiments, variations of temperature and thermal images were recorded synchronously by a multi-path contact-type thermometric apparatus and a thermal image system, respectively. A digital CCD camera was employed to synchronously collect images of specimens’ surfaces. The digital speckle correlation method (DSCM was utilized to analyze the images and to define displacements and strain fields. Our experimental results show that temperature fields have clear responses to opposite stress states in the jog areas of both types of the en echelon faults. Prior to failure of the jog area, its temperature is the highest at the compressional en echelon faults and the lowest at the extensional en echelon faults. Records by DSCM give evidence that mean strain of the jog area is the highest at compressional en echelon faults and the lowest at the extensional en echelon faults. It is revealed that deformation of the en echelon faults occurs in two stages, developing from stress build-up and fault propagation in the jog area to unstable sliding along the fault. Correspondingly, the mechanism of heating-up converts from strain heating into friction heating. During the period of transformation of the temperature rising mechanism, three events are observed in the jog area and its vicinity. Analyses of our experimental results demonstrate that variations of temperatures in the jog area can be indicative of fault sliding and suggest sliding directions. Observations and studies of temperature changes during transformation of the temperature rising mechanism at sensitive portions of faults are of great importance for early detection of precursors of unstable slip on active faults.

  10. The Padul normal fault activity constrained by GPS data: Brittle extension orthogonal to folding in the central Betic Cordillera

    Science.gov (United States)

    Gil, Antonio J.; Galindo-Zaldívar, Jesús; Sanz de Galdeano, Carlos; Borque, Maria Jesús; Sánchez-Alzola, Alberto; Martinez-Martos, Manuel; Alfaro, Pedro

    2017-08-01

    The Padul Fault is located in the Central Betic Cordillera, formed in the framework of the NW-SE Eurasian-African plate convergence. In the Internal Zone, large E-W to NE-SW folds of western Sierra Nevada accommodated the greatest NW-SE shortening and uplift of the cordillera. However, GPS networks reveal a present-day dominant E-W to NE-SW extensional setting at surface. The Padul Fault is the most relevant and best exposed active normal fault that accommodates most of the NE-SW extension of the Central Betics. This WSW-wards dipping fault, formed by several segments of up to 7 km maximum length, favored the uplift of the Sierra Nevada footwall away from the Padul graben hanging wall. A non-permanent GPS network installed in 1999 constrains an average horizontal extensional rate of 0.5 mm/yr in N66°E direction. The fault length suggests that a (maximum) 6 magnitude earthquake may be expected, but the absence of instrumental or historical seismic events would indicate that fault activity occurs at least partially by creep. Striae on fault surfaces evidence normal-sinistral kinematics, suggesting that the Padul Fault may have been a main transfer fault of the westernmost end of the Sierra Nevada antiform. Nevertheless, GPS results evidence: (1) shortening in the Sierra Nevada antiform is in its latest stages, and (2) the present-day fault shows normal with minor oblique dextral displacements. The recent change in Padul fault kinematics will be related to the present-day dominance of the ENE-WSW regional extension versus NNW-SSE shortening that produced the uplift and northwestwards displacement of Sierra Nevada antiform. This region illustrates the importance of heterogeneous brittle extensional tectonics in the latest uplift stages of compressional orogens, as well as the interaction of folding during the development of faults at shallow crustal levels.

  11. Do mesoscale faults near the tip of an active strike-slip fault indicate regional or local stress?

    Science.gov (United States)

    Yamaji, Atsushi

    2017-04-01

    Fault-slip analysis is used in Japan after the Great Tohoku Earthquake (2011) to judge the stability of fractures in the foundations of nuclear power plants. In case a fault-slip datum from a fracture surface is explained by the present stress condition, the fracture is thought to have a risk to be activated as a fault. So, it is important to understand the relative significance of regional and local stresses. To answer the question whether mesoscale faults indicate regional or local stress, fault-slip data were collected from the walls of a trenching site of the Nojima Fault in central Japan—an active, dextral, strike-slip fault. The fault gave rise to the 1995 Kobe earthquake, which killed more than 6000 people. The trench was placed near the fault tip, which produced compressional and extensional local stress conditions on the sides of the fault near the tip. A segment of the fault, which ruptured the surface in 1995, bounded Cretaceous granite and latest Pliocene sediments in the trench. As a result, the stress inversion of the data from the mesoscale faults observed in the trench showed both the local stresses. The present WNW-ESE regional compression was found from the compressive side, but was not in the extensional side, probably because local extension surpassed the regional compression. Instead, the regional N-S compression of the Early Pleistocene was found from the extensional side. From this project, we got the lesson that fault-slip analysis reveals regional and local stresses, and that local stress sometimes masks regional one. This work was supported by a science project of "Drilling into Fault Damage Zone" (awarded to A. Lin) of the Secretariat of Nuclear Regulation Authority (Japan).

  12. Theoretical analysis and experimental measurement for resonant vibration of piezoceramic circular plates.

    Science.gov (United States)

    Huang, Chi-Hung; Lin, Yu-Chih; Ma, Chien-Ching

    2004-01-01

    Based on the electroelastic theory for piezoelectric plates, the vibration characteristics of piezoceramic disks with free-boundary conditions are investigated in this work by theoretical analysis, numerical simulation, and experimental measurement. The resonance of thin piezoceramic disks is classified into three types of vibration modes: transverse, tangential, and radial extensional modes. All of these modes are investigated in detail. Two optical techniques, amplitude-fluctuation electronic speckle pattern interferometry (AF-ESPI) and laser Doppler vibrometer (LDV), are used to validate the theoretical analysis. Because the clear fringe patterns are shown only at resonant frequencies, both the resonant frequencies and the corresponding mode shapes are obtained experimentally at the same time by the proposed AF-ESPI method. Good quality of the interferometric fringe patterns for both the transverse and extensional vibration mode shapes are demonstrated. The resonant frequencies of the piezoceramic disk also are measured by the conventional impedance analysis. Both theoretical and experimental results indicate that the transverse and tangential vibration modes cannot be measured by the impedance analysis, and only the resonant frequencies of extensional vibration modes can be obtained. Numerical calculations based on the finite element method also are performed, and the results are compared with the theoretical analysis and experimental measurements. It is shown that the finite element method (FEM) calculations and the experimental results agree fairly well for the resonant frequencies and mode shapes. The resonant frequencies and mode shapes predicted by theoretical analysis and calculated by finite element method are in good agreement, and the difference of resonant frequencies for both results with the thickness-to-diameter (h/D) ratios, ranging from 0.01 to 0.1, are presented.

  13. Characterization of hyaluronic acid and synovial fluid in stagnation point elongational flow.

    Science.gov (United States)

    Haward, Simon J

    2014-03-01

    Hyaluronic acid (HA) is an important biomacromolecule, which fulfils a number of vital physiological functions (especially in the joint synovial fluid) and also has consumer and pharmaceutical applications. HA solution properties have already been quite thoroughly characterized in response to steady shear flows but are less well understood in highly deforming extensional flows. In this study, flow-induced birefringence measurements are made as a function of the strain rate in planar elongational flow at the stagnation point of a cross-slot device using HA solutions of a range of molecular weights (0.9×10(6) g mol(-1)≤Mw≤4.8×10(6) g mol(-1)) and at dilute concentrations. The results provide macromolecular relaxation times, molecular weight distributions and the extensional viscosities and Trouton ratios of the fluids. The HA relaxation time is found to vary as τ∼Mw1.8, which is consistent with a partially solvated, expanded coil. An intrinsic Trouton ratio is defined, which varies as [Tr]∼Mw2. The measurement of birefringence with strain rate is shown to be highly sensitive to the molecular weight distribution and can resolve subtle changes due to macromolecular degradation and the presence of fracture products. Mechanical degradation experiments in the cross-slots indicate midchain scission of HA macromolecules, strongly suggesting near full extension of the high-molecular weight fraction in the stagnation point extensional flow field. Taken together the results suggest a possible method for analysis of the HA in synovial fluid, and this concept is tested using synovial fluid obtained from porcine tarsal joint. Copyright © 2013 Wiley Periodicals, Inc.

  14. Magnetic fabric as a tool to decipher the kinematics of inverted basins; examples from the western Tethys

    Science.gov (United States)

    Oliva-Urcia, B.; Casas, A. M.; Román-Berdiel, T.; Soto, R.; García-Lasanta, C.; Izquierdo-Llavall, E.; Moussaid, B.; El'Ouardi, H.; Villalain, J.; Torres, S.

    2013-05-01

    Magnetic fabrics have been widely used in different scenarios and rock types since Graham (1954) become aware of the parallelism between the magnetic fabric and the petrofabric of a rock. Two key points are used to decipher the kinematics and strain partitioning within inverted basins where strain markers are scarce: i) the long axis of the magnetic ellipsoid is parallel to extension direction in extensional regimes (Sagnotti et al. 1999; Cifelli et al. 2004); ii) the long axis of the magnetic ellipsoid becomes parallel to the elongation direction in compressive regimes (usually perpendicular to the compression direction) (Parés et al., 1999). Between these two end-members, intermediate fabrics can be also obtained in inverted basins, depending on factors as buttressing, fault inversion and cleavage development (Oliva-Urcia et al., 2011; 2012). In addition, the proper interpretation of magnetic fabrics needs complementary sources of information (i.e., low-temperature magnetic fabric, ferromagnetic fabric, neutron or X-ray texture goniometry, classical structural field analyses, magnetic mineralogy analyses…). Some Mesozoic inverted basins have been studied mainly by means of magnetic fabrics, that allow deciphering (i) the main extensional directions during the basinal stage in Cameros (Iberian Range), Organyá (South Pyrenean Zone), Lusitanian (Portugal) and central and west High Atlas (Aïtt Atab, Ouaouizaght and Argana, Morocco) basins; (ii) the strain distribution and partitioning during compression in the Mauléon (North Pyrenean Zone, France), Cabuérniga (west Pyrenees), and Triassic Nogueres (central Pyrenees) basins, where the fabric is interpreted as the result of the overprint of compressional deformation onto a primary extensional fabric.

  15. Tectonic evolution, structural styles, and oil habitat in the Sonda de Campeche, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Angeles-Aquino, F.J.; Reyes-Nunez, J.; Quezada-Muneton, J.M. [and others

    1994-09-01

    The Sonda de Campeche is located in the southern part of the Gulf of Mexico and hosts one half of the oil reserves of Mexico. The stratigraphic section is 7500 m thick, ranging from Middle Jurassic to Holocene. The Mesozoic sequence includes Callovian salt deposits, Upper Jurassic sandstones, anhydrites, limestones, and shales; and Cretaceous limestones, dolomites, and carbonate breccias. In some places, this sequence displays condensed sections related to an early movement of salt. The Cenozoic sequence is formed mostly of benthonitic shales and minor sandstones, and shows two unconformities: the older one between the lower Miocene and the Oligocene, and the younger one between the middle Miocene and the upper Miocene. In the Sonda de Campeche, three main tectonic regimes are recorded: extensional, compressional, and extensional. The first one extended from Middle Jurassic to Late Jurassic and is related to the opening of the Gulf of Mexico. During this regime, tilted block faults trending northwest-southeast were dominant. The subsequent compressional regime took place at the end of the early Miocene and was related to northeast tangential stresses that added to the flow of Callovian salt, gave rise to huge anticlines, faulted, and often overturned. The last extensional regime extended throughout the middle and late Miocene and is related to salt tectonics and growth faults that have as a detachment surface a middle Miocene shaly horizon. The main source rocks are Tithonian shales and shaly limestones. Oolite bars, slope and shelfal carbonates, and regressive sandstones form the main reservoirs. Evaporites and shales are the regional seals. Recent information indicates that Oxfordian shaly limestones are also important source rocks.

  16. Beware of mereologists bearing gifts: prolegomena to a medical metaphysics.

    Science.gov (United States)

    Khushf, George

    2013-10-01

    This essay considers implications of formal mereologies and ontologies for medical metaphysics. Edward Fried's extensional mereological account of the human body is taken as representative of a prominent strand in analytic metaphysics that has close affinities with medical positivism. I show why such accounts fail. First, I consider how Fried attempts to make sense of the medical case of Barney Clark, the first recipient of an artificial heart, and show that his analytic metaphysical categories do not have the right kind of fit with the case. A proper medical metaphysic should involve a richer two way dialogue with medicine, and it should not just "apply" formal accounts worked out in other settings. Second, I argue that any effort to account for real wholes with extensional mereological sums requires all sorts of ad hoc, supplementary mechanisms that do the real work, and the full repertoire of these mechanisms involves inconsistencies and semantic shifts. Finally, I consider an alternative strand of work on non-extensional whole/part relations that is closer to medicine and that can deepen reflection on some core problems in bioethics, for example, associated with the determination of death when an organism ceases to function as a whole. In addition to the utility such formal ontologies have for addressing traditional problems such as the determination of death, philosophers of medicine should appreciate the increasingly influential role such formal tools are playing in the development of data system ontologies. Assumptions integral to these ontologies have far reaching implications for the way future research and practice in medicine will be conducted, and much greater critical reflection is needed on the full range of issues associated with the development and use of such medical ontologies.

  17. Late Paleozoic to Mesozoic extension in southwestern Fujian Province, South China: Geochemical, geochronological and Hf isotopic constraints from basic-intermediate dykes

    Directory of Open Access Journals (Sweden)

    Sen Wang

    2017-05-01

    Full Text Available The tectonic evolution of SE China block since late Paleozoic remains debated. Here we present a new set of zircon U-Pb geochronological, Lu-Hf isotopic data and whole-rock geochemistry for two stages of basic-intermediate dykes from the southwestern Fujian. The samples were collected from the NE-trending (mainly diabases and NW-trending (mainly diabasic diorites dykes and yielded zircon U-Pb ages of 315 and 141 Ma, with εHf (t values of −8.90 to 7.49 and −23.39 to −7.15 (corresponding to TDM2 values of 850 to 1890 Ma and 737 to 2670 Ma, respectively. Geochemically these rocks are characterized by low TiO2 (0.91–1.73 wt.% and MgO (3.04–7.96 wt.%, and high Al2O3 (12.5–16.60 wt.% and K2O (0.60–3.63 wt.%. Further they are enriched in LREEs and LILEs (Rb, Ba, Th and K, but depleted in HFSEs (Nb, Ta and Zr. The tectonic discrimination analysis revealed that the dykes were formed in an intraplate extensional environment. However, the NW trending dykes show crust-mantle mixed composition, which indicate an extensional tectonic setting with evidence for crustal contamination. The SE China block experienced two main stages of extensional tectonics from late Carboniferous to early Cretaceous. The tectonic evolution of the SE China block from late Devonian to Cretaceous is also evaluated.

  18. Slope tectonics-comparisons and contrasts of structural styles of salt and shale tectonics of the northern Gulf of Mexico with shale tectonics of Offshore Nigeria in Gulf of Guinea

    Science.gov (United States)

    Wu, Shengyu; Bally, Albert W.

    Regional structural styles on the continental slope are revealed by well-imaged deep multi-channel seismic profiles from northern Gulf of Mexico and Offshore Nigeria in Gulf of Guinea. Both provinces are situated on passive continental margins developed during the breakup of Gondwana. The northern Gulf of Mexico as well as Offshore Nigeria are underlain by complex systems of thin skinned upslope extensional fault systems, downslope contractional fold and thrust systems along with large scale salt or shale structures. The interactions between the deformation of mid-Jurassic salt and various stages and patterns of sedimentation on the continental slope are responsible for both extensional growth faults and Tertiary contractional fold and thrust systems in the northern Gulf of Mexico. The slope tectonics style of the northern Gulf of Mexico passive margin is characterized by perennial upslope extension since mid-Jurassic, associated with multistage autochthonous and allochthonous salt deformations along with brief periods of late Tertiary shortening in the down-dip fold belts. Offshore Nigeria is a salt-free progradational margin characterized by upslope extension, various shale structures and downslope toe-thrust systems. Gravity spreading and gliding in response to rapidly prograding Tertiary sedimentation over under-compacted shales resulted in the structural styles of the slope of Offshore Nigeria. Large upslope extensional tectonics are linked to coeval and balanced downslope contractional deformations in the form of shale ridges, massifs and diapirs, and deep basin toe thrusts. Late Miocene-Early Pliocene contractional deformation is widespread across the entire foldbelt, and with later shortening, folding migrated in a landward direction.

  19. Mushroom tyrosinase inhibitory activity and major fatty acid constituents of Amazonian native flora oils

    Directory of Open Access Journals (Sweden)

    Raquel da Silva Teixeira

    2012-09-01

    Full Text Available In order to treat hyperpigmentation-related problems, there has been a global trend in developing cosmetics claiming to have skin-whitening properties, which act by inhibiting melanin biosynthesis. The objective of this work was to evaluate the in vitro mushroom tyrosinase inhibitory activity of five Amazonian native flora oils, and so to verify the possibility of their incorporation into cosmetic products. In addition, the fatty acid composition of the essential oils was determined by gas chromatography-flame ionisation detection in order to determine the main components of these oils. The tyrosinase inhibitory activity of the tested oils was found to be in the following order: açaí (IA50 = 66.08 µg mL-1 > tucumã > patauá > pracaxi > castanha do Brasil. This study suggests that açaí oil has great potential in the treatment of hyperpigmentation and other related disorders, due to its considerable tyrosinase inhibitory activity.Com o intuito de se tratar problemas dermatológicos de hiperpigmentação, há uma tendência mundial no desenvolvimento de cosméticos que possuam propriedades despigmentantes, os quais agem inibindo a biossíntese de melanina. O objetivo deste trabalho foi avaliar in vitro a atividade de inibição da tirosinase de cogumelo de cinco óleos de plantas nativas da Amazônia e, desta forma, verificar a possibilidade de sua incorporação em produtos cosméticos. Ainda, a composição de ácidos graxos dos óleos foi determinada por cromatografia gasosa com detecção por ionização de chama, no intuito de determinar os principais componentes destes óleos. A atividade de inibição da tirosinase dos óleos testados foi encontrada na seguinte ordem: açaí (IA50 = 66,08 µg mL-1 > tucumã > patauá > pracaxi > castanha do Brasil. Este estudo sugere que o óleo de açaí possui grande potencial para o tratamento da hiperpigmentação cutânea e doenças correlatas, devido à sua considerável atividade de inibi

  20. Forager size of the leaf-cutting ant Atta sexdens (Hymenoptera: Formicidae in a mature eucalyptus forest in Brazil

    Directory of Open Access Journals (Sweden)

    Athayde Tonhasca

    2000-12-01

    Full Text Available We determined the size characteristics of foragers of the leaf-cutting ant Atta sexdens in a mature eucalyptus forest in Campos dos Goytacazes, Rio de Janeiro State, Brazil, at daytime (7: 30 to 10: 00 hr and nighttime (19: 00 to 23: 00 hr. There were no significant differences between daytime and nighttime ant mass (Ma, but leaf fragment mass (Ml and burden (B = [Ma + Ml]/Ma, which indicates relative load capacity, were significantly greater at daytime. There was a positive linear relationship between Ma and Ml for the combined daytime and nighttime data, and increases in Ma resulted in lower B. We compared A. sexdens characteristics with published results for Atta cephalotes, a closely related species. A. sexdens is larger and therefore able to carry heavier loads, but its burden is about 72% of the average value for A. cephalotes. We suggest that the lower load capacity of A. sexdens in comparison to A. cephalotes is related to its relatively larger size.Nós determinamos as características de tamanho de forrageiras da saúva Atta sexdens em uma floresta adulta de eucalipto em Campos dos Goytacazes, estado do Rio de Janeiro, Brasil, nos períodos diurno (7: 30 a 10: 00 hr e noturno (19: 00 to 23: 00 hr. Não houve diferença significativa entre o dia e a noite para a massa das formigas (Ma, mas a massa dos fragmentos de folhas (Ml e o esforço ([Ma + Ml]/Ma, o qual indica a capacidade relativa de carga, foram significativamente maiores durante o dia. Houve uma correlação linear positiva entre Ma e Ml para os dados diurnos e noturnos combinados, e o aumento em Ma resultou em esforço menor. Nós comparamos as características de A. sexdens com resultados publicados para Atta cephalotes, uma espécie correlata. A. sexdens é maior e portanto capaz de carregar cargas mais pesadas, mas seu esforço é cerca de 72% do valor médio obtido para A. cephalotes. Nós sugerimos que a menor capacidade de carga de A. sexdens em relação a A

  1. Variabilidade espacial de atributos químicos do solo sob cafeeiro Conilon: relação com textura, matéria orgânica e relevo

    Directory of Open Access Journals (Sweden)

    Diego Lang Burak

    2012-01-01

    Full Text Available Atributos químicos do solo têm relação com outros atributos, inclusive os geomorfológicos, constituindo fatores que controlam sua variabilidade espacial. Dentro desta premissa, delineou-se o objetivo deste trabalho: avaliar a variabilidade dos atributos químicos do solo e sua inter-relação com as frações granulométricas e componentes da matéria orgânica do solo, contextualizando a influência do relevo, utilizando-se a geoestatística e a análise de componentes principais (ACP. A variabilidade espacial dos atributos químicos em menor profundidade foi mais influenciada pelo relevo. Pela ACP, atributos relacionados com a reação do solo (pH, Ca, Mg, Al, m e V contribuíram com o primeiro componente principal (CP1 nas duas profundidades. Contudo, somente o CP1 na profundidade de 0,0 - 0,1 m foi correlacionado com o relevo: maiores altitudes e menores declividades favoreceram o maior teor da fração argila e menor teor de areia grossa, aumentando a retenção de cátions básicos no solo. Substâncias húmicas da matéria orgânica tiveram fraca influência na variabilidade dos atributos químicos, ressalvando a maior relação entre Ca e Mg com ácidos húmicos em locais de textura mais arenosa. Zonas homogêneas e correlatas com atributos geomorfológicos nas duas profundidades foram melhores obtidas para os teores de K, em comparação aos demais atributos. Dessa forma, o uso da análise espacial para segmentação da paisagem em regiões homogêneas visando otimizar o manejo da adubação depende não somente da topografia, mas também dos atributos químicos e da profundidade de amostragem.

  2. Fístula broncovascular: complicação de cateter venoso central percutâneo em neonato

    Directory of Open Access Journals (Sweden)

    D'Elia Cláudio

    2002-01-01

    Full Text Available Objetivos: relatar um caso em que ocorreu falso trajeto de cateter venoso central, com fístula vásculo-pulmonar e graves conseqüências respiratórias correlatas em recém-nascido. Revisar a literatura sobre as complicações respiratórias e não respiratórias relacionadas à introdução de cateteres venosos centrais percutâneos em crianças. Descrição: dados clínicos evolutivos e diagnósticos foram obtidos após revisão do prontuário. O recém-nascido prematuro permaneceu em UTI neonatal após o parto para tratamento de doença da membrana hialina leve e de infecção manifestada posteriormente. No dia seguinte à introdução percutânea do cateter central, para a administração de nutrição parenteral, iniciou desconforto respiratório que progrediu rapidamente. Necessitou de ventilação mecânica para estabelecer troca gasosa adequada. A verificação da trajetória do cateter com o auxílio de contraste radiológico revelou a presença da complicação. Comentários: não são raras as complicações decorrentes da inserção de cateteres centrais, sendo a infecção a mais comum. É importante que os profissionais responsáveis pelos cuidados desses pacientes conheçam as várias outras complicações menos freqüentes, como a trombose vascular e a migração do cateter, com lesões de órgãos e coleções extravasculares de líquidos. Em recém-nascidos, existe apenas um único relato de complicação semelhante à verificada em nosso paciente. Sua raridade pode ter determinado dificuldades para o diagnóstico imediato. São enfatizados os aspectos relacionados aos cuidados, após a introdução destes cateteres, que poderiam facilitar o reconhecimento precoce destas complicações.

  3. Produzioni lattiero-casearie in alpeggio: valutazione igienico-sanitaria

    Directory of Open Access Journals (Sweden)

    V. Chirico

    2003-05-01

    Full Text Available

    L’attività di trasformazione del latte in alpeggio costituisce una realtà di notevole interesse sotto il profilo socio-culturale, ambientale ed economico; ai servizi sanitari spetta il compito di assicurare la qualità igienico-sanitaria dei prodotti lattierocaseari (D.P.R. 54/1997.

    Obiettivi: l’Unità Organizzativa Veterinaria della Lombardia ha predisposto (2001 un piano di campionamento di latte e derivati, prodotti negli alpeggi di una vasta area alpina per valutarne la qualità igienico-sanitaria e trarre indicazioni per migliorare la sorveglianza.

    Metodi: é stata programmata la raccolta di almeno 200 campioni per effettuare: • la ricerca di E.coli, coliformi, S.aureus, L.monocytogenes, Salmonella sulle matrici latte crudo, formaggi freschi e stagionati, burro, ricotta; • la determinazione della carica batterica totale, titolo in cellule somatiche, presenza di sostanze inibenti e tenore in grassi, proteine e lattosio sui campioni di latte crudo. I criteri di valutazione dei risultati analitici si sono basati sui limiti legislativi ove esistenti o su valori fissati o in conformità ai riferimenti internazionali disponibili o per analogia con altre matrici paragonabili.

    Risultati: i risultati (572 campioni hanno evidenziato:

    • assenza di germi patogeni in tutti i prodotti;

    • frequente riscontro di carica batterica totale e cellule somatiche fuori limite nei campioni di latte crudo (45,7% e 66%;

    • buona qualità microbiologica dei formaggi;

    • conta superiore al limite fissato per coliformi ed E.coli nella quasi totalità dei campioni di ricotta e burro. La qualità microbiologica del latte crudo non è risultata correlata a quella dei formaggi.

    Conclusioni: si può ipotizzare che la buona qualità dei formaggi ottenuti a partire da latte scadente sia attribuibile per quelli freschi ai trattamenti termici

  4. APLICAÇÃO ADAPTATIVA DO MODELO FODNESS E MURRAY NA AVALIAÇÃO DA SATISFAÇÃO DE PASSAGEIROS NO AEROPORTO INTERNACIONAL AUGUSTO SEVERO UTILIZANDO REGRESSÃO MULTIVARIADA

    Directory of Open Access Journals (Sweden)

    Teófilo Câmara Mattozo

    2012-06-01

    Full Text Available A Satisfação do cliente e a sua avaliação fazem parte das preocupações dos gestores, sendo cada vez mais comum realizarem-se pesquisas de modo a aferir a sua satisfação. A proposta desse artigo foi avaliar a satisfação do cliente na condição de passageiros no Aeroporto Internacional Augusto Severo em Parnamirim/RN. Esta pesquisa também procurou identificar as dimensões que mais contribuem no resultado da avaliação da satisfação geral dos passageiros. Foi realizada uma revisão da literatura que serviu como base para a pesquisa e para a compreensão e análise dos resultados. A partir daí, foi identificado o modelo Fodness e Murray para a aferição do nível de satisfação quanto à qualidade dos serviços prestados, em função de sua abrangência temporal e espacial, correlata aos sistemas de transporte aéreo, tendo o mesmo sido utilizado como referencial do modelo proposto. Os resultados mostram que entre as dimensões determinantes, quatro foram significativas na explicação da satisfação geral, baseados na aplicação da regressão logística. O modelo estatístico formulado revelou-se bem ajustado e com boa capacidade de explicar o comportamento da satisfação do cliente. Os principais problemas identificados foram: confiança na segurança e nas instalações, disponibilidade de táxi, tempo de espera de táxi, disponibilidade e qualidade dos assentos, conforto do terminal e preços dos restaurantes. Outra percepção foi que a satisfação pode ser afetada pelas variáveis de caracterização estado civil, idade e renda.

  5. Epidemiologia molecolare di Acinetobacter baumannii in un reparto di terapia intensiva con la comparsa della resistenza ai carbapenemici

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    R. Zarrilli

    2003-05-01

    Full Text Available

    L’epidemiologia molecolare delle infezioni da Acinetobacter baumannii nel reparto di terapia intensiva dell’A.U.P. “Federico II” di Napoli è stato studiata in due periodi finestra, da Maggio 1999 a Dicembre 2000 e da Gennaio a Dicembre 2002. L’analisi genotipica degli isolati clinici di A. baumannii da 131 pazienti effettuata mediante elettroforesi su gel a campo pulsante (PFGE ha identificato 9 differenti genotipi.

    Due di essi, i cloni B ed I, predominavano sugli altri ed erano isolati sequenzialmente nel corso delle due epidemie, essendo il clone B responsabile di 67 colonizzazioni e di 14 infezioni, il clone I di 5 colonizzazioni e di 38 infezioni. Inoltre, i due cloni epidemici di A. baumannii mostravano un antibiotipo particolarmente aggressivo, essendo resistenti a tutti gli antimicrobici analizzati, con l’eccezione dei carbapenemici per il clone B e per l’ampicillina-sulbactam e la gentamicina per il clone I.

    L’analisi mediante reazione a catena della polimerasi (PCR mostrava la presenza di due integroni di 2500 and 2200 basi nel genoma dei due cloni epidemici B ed I, rispettivamente, ma non in quello dei cloni sporadici. La sequenza nucleotidica dell’integrone del clone B mostrava quattro cassette geniche: aacC1, che codifica per la resistenza alla gentamicina, due regioni codificanti per proteine non note, ed il gene aadA1a, che codifica per la resistenza alla spectinomicina ed alla streptomicina.

    L’analisi nucleotidica dell’ integrone del clone I mostrava, invece, tre cassette geniche: il gene aacA4, che codifica per la resistenza all’ amikacina, alla netilmicina eed alla tobramicina, una regione codificante per una proteina non nota, ed il gene blaoxa-20, che codifica per una cabapamenasi di classe D. La presenza nei due cloni epidemici di due integroni contenenti diversi geni di resistenza agli amminoglicosidi ed una carbapamenasi di classe D è stata correlata con l’uso elevato nel

  6. Tempos de racialização: o caso da 'saúde da população negra' no Brasil In times of racialization: the case of the 'health of the black population' in Brazil

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    Marcos Chor Maio

    2005-08-01

    Full Text Available Este artigo tem por objetivo analisar as iniciativas para a criação de um campo de reflexão e intervenção política denominado 'saúde da população negra', no período entre 1996 e 2004, que contempla o governo FHC e parte da administração de Lula. A discussão e implementação de políticas de ação afirmativa no Brasil adquire maior visibilidade, especialmente após a 3ª Conferência Mundial contra o Racismo, Discriminação Racial, Xenofobia e Formas Correlatas de Intolerância, sob os auspícios da ONU (Durban, África do Sul, 2001. O artigo descreve a emergência de uma proposta de política compensatória. Em seguida, aborda o debate contemporâneo sobre raça e saúde, sobretudo a literatura biomédica norte-americana, à luz das apropriações dessa discussão por agências e agentes comprometidos com a formulação de uma 'política racial' no âmbito da saúde pública no Brasil.The article analyzes initiatives aimed at creating a field of reflection and political intervention called the 'health of the black population,' which occurred between 1996 and 2004, that is, under the administration of Fernando Henrique Cardoso and part of Luis Inácio Lula da Silva´s administration. During this period, the process of discussing and enacting affirmative action policies in Brazil gained greater visibility, especially following the UN-sponsored Third World Conference on Racism, Racial Discrimination, Xenophobia, and Related Intolerance (Durban, South Africa, September 2001. The article describes the emergence of a proposal of compensatory policy within the Brazilian public health system. It then addresses the contemporary debate on race and health, especially the U.S. biomedical literature, and explores how this discussion has been appropriated by agencies and agents concerned with drawing up a 'racial policy' for the public health sector in Brazil.

  7. L' influenza nella regione Lazio dal 1999 al 2003: casi di sindrome influenzale, ricoveri ospedalieri per malattie respiratorie e coperture vaccinali

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    A. Pasquarella

    2003-05-01

    Full Text Available

    Obiettivi: 1 Descrivere l’andamento dei ricoveri ospedalieri per patologie respiratorie acute e croniche concomitanti alle epidemie stagionali da virus influenzale dal 1999 al 2003, in relazione con la segnalazione dei casi di sindrome influenzale (ILI da parte dei medici sentinella. 2 Misurare l’eccesso dell’ospedalizzazione influenza-correlata nelle diverse fasce di età rispetto ai periodi non epidemici. 3 Analizzare le modificazioni del ricorso al ricovero ospedaliero in relazione al tasso di copertura della vaccinazione antinfluenzale nella popolazione anziana, su scala regionale e nelle diverse ASL.

    Metodi: sono stati estratti dal Sistema Informativo
    Ospedaliero i ricoveri per patologie respiratorie
    influenza-correlate (codici ICD9-CM: 480-487; 460-
    466; 490-496 relativi agli anni 1999-2003.
    L’incidenza di ILI è stata stimata sulla base delle
    segnalazioni dei medici sentinella afferenti alla
    rete FLU-ISS dell’Istituto Superiore di Sanità.

    Per il calcolo dei tassi di copertura è stato utilizzato l’archivio
    nominativo dei soggetti vaccinati contro l’influenza,
    attivo nella regione Lazio dal 1999. Nel periodo considerato sono stati messi in relazione i tassi di ospedalizzazione età-specifici, le incidenze di ILI e le coperture vaccinali. L’eccesso di ospedalizzazione è stato misurato confrontando i tassi relativi ai periodi epidemici e non epidemici.

    Risultati: i tassi di ospedalizzazione per malattie respiratorie sono risultati costantemente superiori nei periodi di maggiore circolazione virale, in particolare negli ultrasessantaquattrenni. Con il progressivo aumento del tasso di copertura vaccinale regionale (da circa il 25% della stagione 1999-2000 a oltre il 60% della stagione 2002-2003 non si è registrata una corrispondente diminuzione dei ricoveri ospedalieri per patologie influenza-correlate.
    L

  8. Radiographic evaluation of periodontal osseous defects: in vitro study = Radiographic evaluation of periodontal osseous defects: in vitro study

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    Gomes Filho, Issac Suzart et al.

    2006-01-01

    Full Text Available Introdução: Embora os métodos de diagnóstico por imagem tenham evoluído permitindo um avanço na detecção precoce das doenças, o exame radiográfico convencional ainda é uma ferramenta importante para a avaliação da condição periodontal. Na literatura correlata existem poucas investigações sobre a especialiade da imagern radiográfica dos defeitos ósseos, evidenciando-se a necessidade de estudos adicionais sobre a temática. Objetivo: Descrever os aspectos radiográficos de defeitos ósseos periodontais produzidos artificialmente em mandíbulas secas, ressaltando os determinantes anatômicos que contribuem na formação dos diferentes tipos de defeito. Método: foram utilizadas quatorze mandíbulas secas nas quais oito tipos de defeitos ósseos periodontais foram produzidos. Fotografias digitais e radiografias convencionais foram obtidas deforma padronizada de cada sítio, antes e após a confecção dos referidos defeitos. Em seguida, as radiografias foram dispostas em negatoscópio e avaliadas por três examinadores. Resultados: Os defeitos ósseos apresentaram características radiográficas distintas, em grande parte, permitindo sua identificação, com exceção dos defeitos de uma, duas e três paredes ósseas. O defeito do septo radicular foi o mais difícil de interpretação enquanto que os defeitos horizontal e vertical foram mais facilmente interpretados. Considerações finais: A interpretação das imagens radiográficas de defeitos ósseos periodontais é dependente do tipo de reabsorção que está sendo avaliada. A descrição do defeito ósseo pode ser facilitada para aqueles tipos que apresentam a morfologia com menor superposição de estruturas óssea e dentária.

  9. Recomendações para o registro/interpretação do mapeamento topográfico do eletrencefalograma e potenciais evocados: Parte II: Correlações clínicas

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    LUCCAS FRANCISCO J.C.

    1999-01-01

    Full Text Available O EEG digital (DEEG e o quantitativo (QEEG representam métodos recém desenvolvidos na prática clínica que, além da utilidade didática e em pesquisa, também mostram importância clínica. As aplicações clínicas são enumeradas a seguir: 1. O DEEG representa um substituto estabelecido para o EEG convencional, pois acrescenta claros avanços técnicos. 2. Algumas técnicas do QEEG são consideradas estabelecidas para uso clínico como adjunto ao DEEG: 2a detecção automática de possíveis descargas epileptiformes ou crises epilépticas em registros prolongados, facilitando o trabalho subsequente do especialista; 2b monitoração contínua do EEG na sala cirúrgica ou na UTI, visando reduzir complicações. 3. Certas técnicas de QEEG são consideradas possíveis opções práticas como uma adição ao DEEG: 3a análise topográfica e temporal de voltagens e dipolos de espículas na avaliação pré-cirúrgica de alguns tipos de epilepsia; 3b análise de frequências em certos casos com doença cérebro-vascular, em quadros demenciais e em encefalopatias, principalmente quando outros testes, como os exames de imagem e o EEG convencional se mostrarem inconclusivos. 4. O QEEG permanece apenas como instrumento de pesquisa em doenças como síndrome pós-concussional, distúrbios do aprendizado, déficit de atenção, esquizofrenia, depressão, alcoolismo e dependência a drogas. O QEEG deve ser usado sempre em conjunto com o DEEG. Devido aos sérios riscos de erros de interpretação, é inaceitável o uso clínico do QEEG e de técnicas correlatas por médicos sem a adequada especialização em interpretação do EEG convencional e também nessas novas técnicas.

  10. Impact of nutrition since early life on cardiovascular prevention

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    Guardamagna Ornella

    2012-12-01

    Full Text Available Abstract The cardiovascular disease represents the leading cause of morbidity and mortality in Western countries and it is related to the atherosclerotic process. Cardiovascular disease risk factors, such as dyslipidemia, hypertension, insulin resistance, obesity, accelerate the atherosclerotic process which begins in childhood and progresses throughout the life span. The cardiovascular disease risk factor detection and management through prevention delays the atherosclerotic progression towards clinical cardiovascular disease. Dietary habits, from prenatal nutrition, breastfeeding, complementary feeding to childhood and adolescence nutrition play a basic role for this topic. The metabolic and neuroendocrine environment of the fetus is fundamental in the body’s “metabolic programming”. Further several studies have demonstrated the beneficial effects of breastfeeding on cardiovascular risk factors reduction. Moreover the introduction of complementary foods represents another important step, with particular regard to protein intake. An adequate distribution between macronutrients (lipids, proteins and carbohydrates is required for correct growth development from infancy throughout adolescence and for prevention of several cardiovascular disease risk determinants in adulthood. The purpose of this review is to examine the impact of nutrition since early life on disease. La malattia cardiovascolare rappresenta la principale causa di morbilità e mortalità dei paesi occidentali ed è correlata a degenerazione vascolare aterosclerotica. I fattori di rischio cardiovascolari quali dislipidemia, ipertensione, insulino resistenza e obesità accelerano tale processo il cui esordio è noto sin dell’età pediatrica ed evolve nel corso della vita. L’individuazione e la cura dei fattori di rischio cardiovascolari mediante la prevenzione dei fattori causali ritardano la progressione dell’aterosclerosi e l’insorgenza dei sintomi cardiovascolari. La

  11. Lo Stadio della Vittoria e il Monumento ai Caduti di Macerata: Cesare Bazzani tra monumentalismo e funzionalismo / The Victory Stadium and the Monument to the Fallen of the Great War in Macerata: Cesare Bazzani between monumentalism and functionalism

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    Mauro Saracco

    2016-06-01

    Full Text Available Il tessuto urbano maceratese viene fortemente trasfigurato nei primi decenni del 900 da alcuni grandi interventi edilizi condotti sia all’interno del tracciato storico delle mura urbiche sia nella immediata periferia e contrassegnati da quella ricerca di “modernizzazione”, anche funzionale, delle città strettamente correlata alle istanze propagandistiche di regime. Il tratto distintivo del caso maceratese è che tutti gli interventi in parola furono opera di un unico progettista, Cesare Bazzani, con una densità di realizzazioni e proposte progettuali inconsueta per una piccola realtà. In questa “rivoluzione” urbana spicca la realizzazione dello Stadio della Vittoria e il monumento ai caduti della grande guerra, in cui soluzioni di disegno urbano, istanze celebrative e nuovi modelli funzionali appaiono strettamente fusi, quasi a definire una nuova tipologia architettonica. Anche le soluzioni tecnico costruttive adottate, pur subordinate ad una immagine di classicità,  danno conto di questa ricerca di “ibridazione” di modelli consolidati, dando vita ad una realizzazione di notevole qualità tecnica.    The urban area of Macerata is greatly transformed in the early decades of the 900 by some big construction projects, conducted both inside the historic center both in the suburban, all marked by that search for "modernization", also functional, of the cities closely related to regime propaganda instances. The distinctive feature of Macerata is that all the projects in question,  were the work of a single designer, Cesare Bazzani,  with a density of achievements and project proposals, unusual for a small reality. This "urban revolution" stands out the realization of the Victory Stadium and the monument to the fallen of the Great War, where urban design solutions, celebratory instances and new functional models seem to be closely fused as if to define a new architectural typology. Also the technical and construction solutions

  12. Radiation exposure in nuclear medicine: real-time measurement

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    Iara Sylvain

    2002-09-01

    Full Text Available French regulations have introduced the use of electronic dosimeters for personal monitoring of workers. In order to evaluate the exposure from diagnostic procedures to nuclear medicine staff, individual whole-body doses were measured daily with electronic (digital personal dosimeters during 20 consecutive weeks and correlated with the work load of each day. Personal doses remained always below 20 µSv/d under normal working conditions. Radiation exposure levels were highest to tech staff, nurses and stretcher-bearers. The extrapolated annual cumulative doses for all staff remained less than 10 % of the maximum legal limit for exposed workers (2 mSv/yr. Electronic dosimeters are not technically justified for routine survey of staff. The high sensitivity and immediate reading of electronic semiconductor dosimeters may become very useful for exposure control under risky working conditions. It may become an important help for optimising radiation protection.A legislação francesa introduziu o uso de dosímetros eletrônicos para monitoração da exposição do trabalhador. Afim de avaliar a exposição do trabalhador proveniente de exames diagnósticos em medicina nuclear, doses individuais do corpo inteiro foram medidas diariamente com dosímetros eletrônicos (digitais durante 20 semanas consecutivas e correlatas com as atividades de trabalho de cada dia. As doses foram sempre inferiores à 20 µSv por dia em condições normais de trabalho. Os níveis de exposição de radiação mais elevados foram para os enfermeiros, manipuladores e maqueiros. A extrapolação da dose anual para todos os trabalhadores foi menos que 10 % do limite máximo legal para os trabalhadores expostos (2 mSv/ano. Dosímetros eletrônicos não são tecnicamente justificados para a o controle de rotina da exposição dos trabalhadores, mas a alta sensibilidade e a leitura imediata desses dosímetros podem vir a serem muito úteis para o controle da exposição em condi

  13. Análise do gerenciamento de resíduos sólidos e proposição de melhorias: estudo de caso em uma marcenaria de Cariacica, ES

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    Miraya Dutra Degli Esposti Caetano

    Full Text Available Resumo: O presente trabalho investiga o gerenciamento de resíduos sólidos em uma empresa moveleira sediada no município de Cariacica, ES. Primeiro, foram obtidas informações acerca do setor moveleiro da região, por meio de material bibliográfico, junto à Associação de Indústrias e Produtos de Insumos do Setor Mobiliário de Cariacica (AMOVEL, à Secretaria Municipal de Desenvolvimento Econômico e Turismo (SEDETUR da Prefeitura de Cariacica e ao Sindicato das Indústrias de Madeira e Atividades Correlatas em Geral da Região Centro Sul do Estado do Espírito Santo (SINDMADEIRA/ES. Em seguida, elaborou-se um questionário para coleta de informações. Depois, escolheu-se uma marcenaria para a análise em questão. Feito isso, por meio de visitas técnicas e entrevistas com o coordenador de produção da empresa, coletaram-se informações sobre o processo produtivo de móveis, com foco na utilização da matéria-prima e insumos, geração de resíduos sólidos, presença de técnicas de Produção mais Limpa, Licença Ambiental e Sistema de Gestão Ambiental. Ao final, constatou-se que, mesmo a empresa possuindo várias técnicas de Produção mais Limpa, há uma elevada quantidade de resíduos sólidos gerados ao longo da cadeia produtiva e que o percentual de perda de matéria-prima é superior a 20%, acima dos 10% estimados inicialmente. Com vistas nisso, alternativas com base no conceito de Produção mais Limpa foram propostas, para melhor aproveitamento e destinação dos resíduos sólidos gerados.

  14. Current outlook of ethics in research with human subjects Panorama atual da ética em pesquisa em seres humanos

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    Marystella Tomoe Takahashi

    2011-04-01

    Full Text Available In the last decades, medical care has been increasingly permeated by the concept of evidence-based-medicine, in which clinical research plays a crucial role in establishing diagnostic and treatment. Following the improvements in clinical research, we have a growing concern and understanding that some ethical issues must be respected when the subjects are human beings. Research with human subjects relies on the principles of autonomy, beneficence, no maleficence and justice. Ordinance 196/96 from the National Health Board adds to the Brazilian legislation such renowned bioethical principles. AIM: Discuss the main ethical aspects involved in research with human subjects. MATERIALS AND METHODS: Critical analysis of Ordinance 196/96 and related literature. CONCLUSION: Ordinance 196/96 rules research with human subjects; nevertheless, it requires more in-depth discussions regarding the informed consent, use of placebo, research with vulnerable populations and research in developing countries.Nas últimas décadas, a medicina tem sido cada vez mais permeada pelo conceito de medicina baseada em evidências, na qual a pesquisa clínica possui papel crucial no estabelecimento de diretrizes diagnósticas e terapêuticas. Com o avanço da pesquisa clínica, surgiu a preocupação e o entendimento que certos padrões éticos devam ser obedecidos quando o objeto de estudo é o ser humano. A pesquisa em seres humanos baseia-se nos princípios da autonomia, beneficência, não maleficência e justiça. A Resolução 196/96 do Conselho Nacional de Saúde incorpora à legislação brasileira tais princípios bioéticos consagrados. OBJETIVO: Discutir os principais aspectos éticos envolvidos na pesquisa em seres humanos. MATERIAL E MÉTODO: Análise crítica da Resolução 196/96 do CNS e literatura correlata. CONCLUSÃO: A Resolução 196/96 do Conselho Nacional de Saúde regulamenta a experimentação em seres humanos, no entanto necessita de discussões mais

  15. Use by small mammals of short-rotation plantations in relation to their structure and isolation

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    Marta Giordano

    2010-06-01

    . Dal nostro studio è emerso che le SRF sono largamente sfruttate dai micromammiferi, soprattutto in autunno e che il successo di cattura è massimo negli impianti a file binate. L’abbondanza dei micromammiferi è risultata inversamente correlata alla distanza dagli ambienti che offrono copertura, come boschi o altri impianti di arboricoltura. I risultati hanno mostrato che le SRF possono considerarsi un ambiente idoneo per i micromammiferi, ed esse potrebbero funzionare da habitat di collegamento tra i frammenti di altri habitat utilizzati dai micromammiferi.

    doi:10.4404/hystrix-20.2-4443

  16. Tendências curriculares no ensino de música: indefinição e permanência de um presente eterno

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    Celso do Prado Ferraz de Carvalho

    2016-11-01

    Full Text Available The theses about post-modernity and your expressions on the social reforms implemented since 1990, have been used and incorpored from the musical education, in the teaching and formation of the docent. Our general objective in this text é to reflect about this question seeing it through the subjects teacher pratical-reflexive; pedagogy focused in docent’s competences, in learn how to learn and the overvaluation of knowledges of ordinary experience. A search on the literature of musical education, above all in articles published in Journal and Anais of ABEM (Brazilian Association for Music Education of last ten years, suggest a large diffusion, in music educational area, of post-modernity/ post-structuralist preconditions about social and culture life. That diffusion happens with a larger incorporation and your associated conceptions of formation and knowledge. The marxism’ referential concludes that this theses can produce a retreat of the theory, depolitisation of the debate and impoverishment of the know act. As teses sobre a pós-modernidade, bem como a sua expressão nas reformas educacionais implementadas a partir da década de 1990, têm sido amplamente incorporadas pelo campo da educação musical, no ensino e na formação docente. Nosso objetivo neste texto é problematizar essa questão analisando os temas do professor prático-reflexivo e de uma pedagogia centrada em competências docentes, no aprender a aprender e na sobrevalorização dos saberes da experiência cotidiana. O levantamento na literatura da área baseado, sobretudo em artigos publicados na Revista e nos Anais da ABEM (Associação Brasileira de Educação Musical nos últimos dez anos, sugere a larga difusão, no campo da educação musical, dos pressupostos pós-modernos/pós-estruturalistas acerca da vida social e cultural. Tal difusão se daria em paralelo à vasta incorporação das suas correlatas concepções de formação e conhecimento. A partir do

  17. Risorse trofiche o disturbo antropico? Elaborazione preliminare e validazione di un indice di idoneità ambientale per l'orso bruno nell'Appennino

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    M. Bello

    2003-10-01

    Full Text Available In un'area di studio nell'Appennino abruzzese (ampia circa 250 km² sono state campionate variabili ambientali relative alla vegetazione, topografia, e presenza antropica in 2110 plot distribuiti lungo transetti da 1 km in 72 celle (1 km² selezionate casualmente dal reticolato geografico UTM. Utilizzando tematismi digitali sono state calcolate, tramite GIS, altre variabili ambientali relative alle stesse categorie. Le variabili sono state combinate in 14 indici (V1-14 utilizzati per calcolare un indice di idoneità ambientale relativo ai plot e alle celle campionate. Sono stati elaborati: A- un indice complessivo di idoneità (HSItotale e, B- 2 indici di idoneità relativi alla disponibilità di risorse trofiche e alla presenza umana (HSIcibo e HSIuomo, rispettivamente. Il valore medio di HSIcibo è stato pari a 0,23, in relazione ai valori medi degli indici di idoneità per la disponibilità di invertebrati (0,01, ghiande (0,004 e alla copertura percentuale di arbusti (0,06. Il valore medio di HSIuomo è risultato maggiore (0,32, soprattutto in relazione all'indice relativo alle variabili pendenza (0,69 e distanza dagli insediamenti umani (0,60. L'indice complessivo medio HSItotale è stato pari a 0,27. Il modello è stato validato comparando, per ogni cella, il valore dei tre indici con l'abbondanza relativa dell'orso bruno stimata lungo percorsi campione dal 1993 al 1998. Gli indici HSItotale e HSIuomo sono risultati significativamente e direttamente correlati con l'abbondanza relativa dell'orso (0,40 >rs< 0,44; p< 0,001; n= 72, mentre la frequentazione dell'orso non è risultata correlata significativamente all'indice HSIcibo (rs= 0,06; p> 0,5; n= 72. Questi dati preliminari, che saranno integrati dai risultati di ulteriori campionamenti in corso, indicano chiaramente che l

  18. EDUCAÇÃO AMBIENTAL: UMA PERSPECTIVA METODOLÓGICA EMPREGADA PELO PROJETO NATIVAS NO CAMPUS DA UFRN

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    Ricardo Teixeira Andrade

    2008-07-01

    Full Text Available O presente trabalho, tendo como tema ‘Educação Ambiental: uma perspectiva metodológica empregada pelo Projeto Nativas no Campus da UFRN’, é dedicado ao estudo da educação ambiental realizada através da prática de arborização e abordagem teórica correlata. Foram abordadas cinco atividades de educação ambiental, realizadas no Campus Universitário da UFRN, no período de julho/2005 a julho/2006, e contemplados estudantes de escolas públicas e particulares, na faixa etária de 11 a 15 anos. O objetivo geral foi desenvolver a construção da educação ambiental com estudantes de escolas públicas e particulares através de uma perspectiva metodológica empregada pelo Projeto Nativas no Campus (PNC - um projeto de extensão da Universidade Federal do Rio Grande do Norte (UFRN, que desenvolve atividades ambientais nos âmbitos social e acadêmico, por meio da prática de arborização urbana. A metodologia utilizada buscou integrar a educação informal à formal e consistiu em dois estágios: programação e efetivação. Esta última sendo desenvolvida em quatro momentos: recepção dos alunos, exposição teórica dos temas ligados ao meio ambiente, arborização e momento de interação. Os resultados obtidos têm por base a análise da metodologia aplicada quanto à sua funcionalidade, sendo expostos em função do comportamento observado nos estudantes e registros efetivados pelos mesmos (questionários e desenhos. Concluiu-se que a utilização dessa metodologia para a realização de atividades de educação ambiental foi válida. A temática arborização permitiu a abordagem de temas inerentes a educação ambiental com vasta abrangência, tanto no âmbito da educação formal, como também em destaque, da educação informal. PALAVRAS-CHAVE: Educação ambiental, arborização, confecção de desenhos, Nativas no Campus – UFRN, Meio Ambiente.

  19. TECNOGRAN: TODO PISO SERÁ PALCO. TODA PAREDE, MURAL. E A CIDADE INTEIRA, POESIA.

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    Danielle Denes dos Santos Carstens

    Full Text Available RESUMO Este caso apresenta a Tecnogran, empresa paranaense de revestimentos de alto tráfego atuante no segmento de pisos para supermercados, shopping centers, áreas externas, obras públicas e de acessibilidade. O caso descreve o histórico, as características da organização e do setor, abordando impasses enfrentados pela Tecnogran: pressões por preço e demandas de mercado. A empresa é líder no mercado nacional e, apesar disso, encontra dilemas ao buscar se consolidar como inovadora frente a seus concorrentes. O caso é analisado sob as perspectivas das teorias: Estratégias Genéricas e Vantagem Competitiva Ambiental; Teoria Baseada em Recursos; e Teoria de Recursos, Processos e Valores na Inovação. O caso apresenta também as respostas da empresa: inovações em produtos e serviços, e alterações em processos produtivos para manutenção de sua liderança no mercado nacional. As informações para a elaboração do caso foram obtidas por entrevistas semiestruturadas com os gestores da Tecnogran e por dados secundários, tais como publicações, documentos da empresa e sites. Este caso de ensino poderá ser utilizado nas disciplinas de Administração Estratégica, Gestão da Inovação, Marketing e disciplinas correlatas, em cursos de graduação e pós-graduação com foco em negócios de empresas. Os principais objetivos educacionais são: sensibilizar alunos para perceber as estratégias empresariais; analisar os modelos de gestão em busca de vantagem competitiva; identificar modelos estratégicos organizacionais; assinalar a relação entre competências organizacionais e vantagem competitiva sustentável; e compreender a importância e os desafios da inovação para as organizações.

  20. Estado emocional de alunos da primeira série de um Grupo Escolar - Ginásio da cidade de São Paulo, Brasil: problemática de saúde pública? Emotional disturbances of 1st grade school children: a Public Health Problem?

    Directory of Open Access Journals (Sweden)

    Helena Savastano

    1977-12-01

    Full Text Available Estudou-se uma amostra representativa de alunos da 1.ª série de um Grupo Escolar-Ginásio da rede estadual da cidade de São Paulo, com o objetivo de compreender a dinâmica emocional dessas crianças. Os alunos foram estratificados em fracos e não fracos quanto à aprendizagem e disciplinamento. Utilizou-se o teste de apercepção temática de Bellak e Bellak e os resultados demonstraram, que 43% das crianças não estão emocionalmente ajustadas para enfrentar o ambiente escolar, onde a figura do adulto (professor é visualizada como agressiva e os castigos são vistos, pelas crianças, como ameaçadores; os alunos fracos revelaram maior atraso no desenvolvimento psicossocial em relação aos não fracos. Estes dados, possivelmente, esclarecem parte das dificuldades de adaptação dessas crianças �� situação escolar e sugerem: 1º maior atenção dos técnicos de educação, de saúde e áreas correlatas, para esses problemas; 2º maiores conhecimentos pelos educadores, dos aspectos do desenvolvimento psicossocial da criança.Psychological and epidemiological aspects of emotional dynamics of children enroled in the first grade of a state school of the city of São Paulo, Brazil, were studied based on results of Children's Tematic Test (CAT, of Bellak and Bellak. The mentioned test showed that the group is made up of emotionally immature children, lacking affection, especially those considered of low learning capacity. The figure of the adult, as seen by the students, is inadequate, punitive, indiferent and agressive. The results suggest that teachers should have a greater understanding reference to such problems and should give attention to these students, thus leading to the conclusion that first grade classes should not have so many students. The results also suggest that parents should have more knowledge and understanding as regards child development from conception, as well as better family struture as to more adequate