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Sample records for deformacao extensional brasiliana

  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. Antibiotic oxylipins from Alternanthera brasiliana and its endophytic bacteria.

    Science.gov (United States)

    Trapp, Marília Almeida; Kai, Marco; Mithöfer, Axel; Rodrigues-Filho, Edson

    2015-02-01

    Bioassay-guided fractionation of Alternanthera brasiliana stem extracts resulted in the isolation of an antibiotically active fraction. Five human pathogenic bacteria were used to guide the fractionation process for the isolation of antimicrobial compounds. Finally, 17 linoleate oxylipins were identified by LC-MS/MS and NMR spectroscopy. Five of the isolated compounds present in A. brasiliana tissues were also detected to be synthesized by endophytic bacteria of the genus Bacillus that were isolated from A. brasiliana. It is speculated that the antibiotic oxylipins from A. brasiliana might derive from bacteria and be involved in an ecological relationship between this plant and its endophytes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Healing efficacy of methanol extract of leaves of Alternanthera brasiliana Kuntze in aged wound model.

    Science.gov (United States)

    Barua, Chandana Choudhury; Begum, Shameem Ara; Sarma, Dilip Kumar; Pathak, Debesh Chandra; Borah, Rumi Saikia

    2012-09-01

    The methanol extract of Alternanthera brasiliana Kuntze (Family: Amaranthaceae) leaf was investigated for its wound healing effect by excision wound model (in vivo) in aged Sprague Dawley rats. In excision wound model, compared to the control group, percent contraction of wound was significantly (P brasiliana-treated group (5% w/w ointment). The collagen, elastin, and hydroxyproline contents of the granulation tissue of A. brasiliana-treated group increased significantly (P brasiliana possesses significant wound healing potential in aged animal wound model.

  4. Healing efficacy of methanol extract of leaves of Alternanthera brasiliana Kuntze in aged wound model

    OpenAIRE

    Barua, Chandana Choudhury; Begum, Shameem Ara; Sarma, Dilip Kumar; Pathak, Debesh Chandra; Borah, Rumi Saikia

    2012-01-01

    The methanol extract of Alternanthera brasiliana Kuntze (Family: Amaranthaceae) leaf was investigated for its wound healing effect by excision wound model (in vivo) in aged Sprague Dawley rats. In excision wound model, compared to the control group, percent contraction of wound was significantly (P < 0.01) higher in A. brasiliana-treated group (5% w/w ointment). The collagen, elastin, and hydroxyproline contents of the granulation tissue of A. brasiliana-treated group increased significantly ...

  5. Morfo-anatomia das folhas de Alternanthera brasiliana e Alternanthera dentata (Amaranthaceae)

    OpenAIRE

    Pereira, Danielle F.; Zanon, Ricardo B.; Zanetti, Gilberto Dolejal; Manfron, Melânia Palermo; Athayde, Margareth L.

    2008-01-01

    Este trabalho tem como objetivo contribuir na diferenciação entre as especies Alternanthera brasiliana (L.) Kuntze e Alternanthera dentata (Moench) Stuchlik (Amaranthaceae). As folhas de A. brasiliana e A. dentata apresentam características macroscópicas diferenciais relevantes no limbo (venação, forma, cor e transparência) e no pecíolo em seção transversal. Microscopicamente A. dentata exibe uma cutícula mais tênue e epiderme hipostomática e não anfiestomática como em A. brasiliana. Os trico...

  6. Polymer fragmentation in extensional flow

    International Nuclear Information System (INIS)

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

    2001-01-01

    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

  7. 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...

  8. Polymer fragmentation in extensional flow

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Flavonol robinobiosides and rutinosides from Alternanthera brasiliana (Amaranthaceae) and their effects on lymphocyte proliferation in vitro

    OpenAIRE

    Brochado,Claudia de O.; Almeida,Ana P. de; Barreto,Beatriz P.; Costa,Leandro P.; Ribeiro,Luciene S.; Pereira,Rachel L. da C.; Koatz,Vera L. Gonçalves; Costa,Sonia S.

    2003-01-01

    The extract of the medicinal species Alternanthera brasiliana Kuntze afforded six di- and triglycosyl kaempferol and quercetin derivatives. Their structures were elucidated based on the ¹H- and 13C-NMR data and are reported here for the first time in this genus. Kaempferol 3-O-robinobioside and kaempferol 3-O-rutinoside significantly inhibited the human lymphocyte proliferation in vitro. O extrato da espécie medicinal Alternanthera brasiliana Kuntze forneceu seis derivados di- e triglicosi...

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

    OpenAIRE

    Biavatti, MW; Bellaver, MH; Volpato, L; Costa, C; Bellaver, C

    2003-01-01

    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 soybe...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Kinematic models of extensional structures

    International Nuclear Information System (INIS)

    Groshong, R.H. Jr.

    1990-01-01

    This paper discusses kinematic models that can relate faults of different types and different positions within a single dynamic system and thereby offer the potential to explain the disparate seismic activity characteristic of extensional terrains. The major styles are full grabens, half grabens, domino blocks, and glide-block systems. Half grabens, the most likely models for Basin and Range structure, are formed above a master fault of decreasing dip with depth and a hangingwall that deforms as it passes over the curved fault. Second-order normal faults, typically domino style, accommodate the required hangingwall deformation. According to the author low-angle detachment faults are consistent with the evidence of seismicity only on high-angle faults if the hangingwall of the detachment is broken by multiple half-graben systems

  15. Effect of Alternanthera brasiliana (L) Kuntze on healing of dermal burn wound.

    Science.gov (United States)

    Baru, Chandana C; Talukdar, Archana; Begum, Shameem A; Buragohain, Bhaben; Roy, Jayanti Datta; Pathak, Debesh C; Sarma, Dilip K; Gupta, Asheesh K; Bora, Rumi S

    2012-01-01

    Wound healing activity of methanol extract of Alternanthera brasiliana [5% (w/w) ointment] was evaluated in experimental burn wound model in rats. Healing potential was assessed by the rate of wound contraction, estimation of anti-oxidants like catalase, superoxide dismutase, reduced glutathione, protein, vitamin C and hydroxyproline, along with histopathological examination on 8th day post wounding. The statistical data indicated that there was significant increase in wound contraction along with augmented level of antioxidants in granulation tissues in A. brasiliana treated group. Histopathological assessment of the granulation tissue revealed formation of epidermis with keratin layer and deposition of collagen fibers after treatment with the plant extract.

  16. Extensional viscosity of microfibrillated cellulose suspensions.

    Science.gov (United States)

    Moberg, Tobias; Rigdahl, Mikael; Stading, Mats; Levenstam Bragd, Emma

    2014-02-15

    The extensional properties of micro fibrillated cellulose (MFC)-suspensions at different fibril concentrations and with different amounts of added sodium chloride were evaluated. The MFC-suspensions were obtained by diluting a stock solution consisting of 0.95 wt.% cellulose with either deionized water or sodium chloride solution, giving a series of different concentrations and sodium chloride contents. The extensional viscosities of the suspensions were measured utilizing contraction flow geometry. Here the specimens were forced through a hyperbolic nozzle and the required pressure drop over the nozzle was measured. The extensional viscosity exhibited an extensional-thinning behaviour over the extensional strain rates used. Furthermore the extensional viscosity decreased with decreasing concentration of the suspensions, in similarities with the shear properties of the specimens. For the suspensions containing sodium chloride, the extensional viscosity appeared to increase when the concentration of sodium chloride was increased. But excessive amounts of added sodium chloride promoted an agglomeration of the suspensions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Photodynamic inactivation of yeast and bacteria by extracts of Alternanthera brasiliana.

    Science.gov (United States)

    Andreazza, Nathalia L; de Lourenco, Caroline C; Siqueira, Carlos A T; Sawaya, Alexandra C H F; Lapinski, Tadia F; Gasparetto, Adriana; Khouri, Sonia; Zamuner, Stella R; Munin, Egberto; Salvador, Marcos Jose

    2013-08-01

    This study was undertaken to evaluate the effect of Alternathera brasiliana (Amaranthaceae) extracts as photosensitizing agents in photodynamic antimicrobial therapies (PACT) against Staphylococcus aureus, Staphylococcus epidermidis and Candida dubliniensis. The crude hexane and ethanol extracts were obtained from A. brasiliana whole plant and showed absortion from 650 to 700 nm. Also, singlet molecular oxygen (1O2) production (type II photosensitization reaction) was examined, and the results show that 1,3-diphenylisobenzofuran photodegradation was greatly enhanced in the presence of the A. brasiliana extracts. One plate in each assay was irradiated while the other was not irradiated, the number of colony-forming units per milliliter (CFU/mL) was obtained, and data analyzed by the Tukey test. The chemical composition of the extracts was determined by chromatographic and spectrometric techniques; steroids, triterpenes, and flavonoids were identified. Laser irradiation alone at 685 nm using diode laser, output power of 35 mW, and energy of 28 J/cm2, or non-irradiated crude extracts in sub-inhibitory concentration did not reduce the number of CFU/mL significantly, whereas irradiated hexane and ethanol extracts, in sub-inhibitory concentrations, inhibited the growth of these microorganisms. The photoactivation of hexane and ethanol extracts of A. brasiliana, in sub-inhibitory concentrations, using red laser radiation at 685 nm had an antimicrobial effect.

  18. Wound healing activity of methanolic extract of leaves of Alternanthera brasiliana Kuntz using in vivo and in vitro model.

    Science.gov (United States)

    Barua, C C; Talukdar, A; Begum, S A; Sarma, D K; Fathak, D C; Barua, A G; Bora, R S

    2009-12-01

    Wound healing activity of methanolic extract of leaves of Alternanthera brasiliana Kuntz was studied by excision and incision wound model (in vivo) in Sprague Dawley rats and by Chorioallantoic membrane (CAM) model (In vitro) in 9-day-old embryonated chicken eggs. In excision wound model, compared to the control group, per cent contraction of wound was significantly higher in A. brasiliana (5% w/w ointment) treated group. In incision wound model, tensile strength of the healing tissue after treatment with A. brasiliana was found to be significantly higher compared to the control group indicating better wound healing activity of the test plant. These findings were also confirmed by histopathological examination. The extract also promoted angiogenesis as evidenced by CAM model. The results suggested that methanolic extract of A. brasiliana possess significant wound healing potential in normal wound.

  19. Extensional scientific realism vs. intensional scientific realism.

    Science.gov (United States)

    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.

  20. 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....

  1. Influence of Alternanthera brasiliana (L.) Kuntze on Altered Antioxidant Enzyme Profile during Cutaneous Wound Healing in Immunocompromised Rats

    OpenAIRE

    Barua, Chandana Choudhury; Ara Begum, Shameem; Talukdar, Archana; Datta Roy, Jayanti; Buragohain, Bhaben; Chandra Pathak, Debesh; Kumar Sarma, Dilip; Saikia Bora, Rumi; Gupta, Asheesh

    2012-01-01

    Alternanthera brasiliana (L.) Kuntze (Amaranthaceae) is a herbaceous plant used against inflammation, cough, and diarrhea in Brazilian popular medicine. In our preliminary study, promising wound healing activity of methanol extract of leaves of A. brasiliana (MEAB) was observed in normal excision and incision wound models. Therefore, the present study was designed to investigate the wound healing activity along with the antioxidant enzyme profile during cutaneous excision immunocompromised wo...

  2. Evaluation of the pharmacological activity of the Alternanthera brasiliana aqueous extract.

    Science.gov (United States)

    Formagio, Elen Luiza Pelisoli; Mendel, Monique Theissen; Fracasso, Rafael; Knobloch, Jéssica Gil; Teixeira, Paula Winckler; Kehl, Laís; Maluf, Rage Weidner; Picoli, Simone Ulrich; Ardenghi, Patrícia; Suyenaga, Edna Sayuri

    2012-11-01

    Alternanthera brasiliana (L.) Kuntze (Amarantaceae) is widely used in Brazilian traditional medicine as an analgesic, anti-inflammatory and antibacterial. To investigate the potential anti-inflammatory, analgesic, anxiolytic, and locomotor effect of the infusions in preclinical models. Anti-inflammatory activity was evaluated by a carrageenan-induced pleurisy test in Wistar rats (200 and 400 mg/kg, n = 6-7). Analgesic activity was evaluated by the number of abdominal contractions induced by 0.6% acetic acid administered to Swiss mice (25, 50, 100, 200, and 400 mg/kg, n = 10). Effects on the central nervous system (CNS) were evaluated in Wistar rats (100, 200, and 400 mg/kg, n = 10) using open field and plus maze models. Possible anti-inflammatory activity was indicated by the significant reduction of 19.8% for 200 mg/kg (p brasiliana has a potential pharmacological effect on inflammation and pain.

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

    Science.gov (United States)

    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. colitime period. NoV GI was the most adsorbed virus after 24h. HAV concentration was time, reaching its highest values after 24h (times (0, 1, 1.5, 3 and 5mins), viral infectivity was evaluated using ICC-et-RT-qPCR. The temperature inside the DT remained time and after 5min of cooking the HAdV reached a decay of 90% (1 log 10 ). The results showed a real warn to the consumers that can be exposed to infectious human viruses if they eat these clams improperly cooked. HAV was the most detected virus in these animals, which may lead to outbreaks. A. brasiliana exhibited distinct behavior in NoV GI bioaccumulation and persistence, pointing to the need for further studies about the cellular ligands used by these viruses to become attached to these clams. Copyright © 2017. Published by Elsevier B.V.

  4. Flavonol robinobiosides and rutinosides from Alternanthera brasiliana (Amaranthaceae and their effects on lymphocyte proliferation in vitro

    Directory of Open Access Journals (Sweden)

    Brochado Claudia de O.

    2003-01-01

    Full Text Available The extract of the medicinal species Alternanthera brasiliana Kuntze afforded six di- and triglycosyl kaempferol and quercetin derivatives. Their structures were elucidated based on the ¹H- and 13C-NMR data and are reported here for the first time in this genus. Kaempferol 3-O-robinobioside and kaempferol 3-O-rutinoside significantly inhibited the human lymphocyte proliferation in vitro.

  5. Effect of Alternanthera brasiliana in experimentally induced inflammatory bowel disease in albino rats

    OpenAIRE

    Shivashankar P.; Purushotham K.; Mangala Lahkar

    2016-01-01

    Background: Inflammatory bowel disease (IBD) is a chronic inflammatory condition affecting the gastrointestinal tract with limited therapeutic options. The present study aimed to investigate the effect of methanolic extract of Alternanthera brasiliana in acetic acid-induced inflammatory bowel disease (IBD) in albino rats. Methods: A total of 36 animals were included in the study. Animals were divided into six groups (n = 6 ): group I - control (normal saline), group II-AA+ normal saline, g...

  6. Betalains and phenolic compounds of leaves and stems of Alternanthera brasiliana and Alternanthera tenella.

    Science.gov (United States)

    Deladino, L; Alvarez, I; De Ancos, B; Sánchez-Moreno, C; Molina-García, A D; Schneider Teixeira, A

    2017-07-01

    Betacyanins and phenolic compounds from acetonitrile:acidified water extracts of Alternanthera brasiliana and Alternanthera tenella were characterized and quantified using a high-performance liquid chromatography system coupled with diode array and electrospray mass spectrometry detection. Four betacyanins (amaranthine, isoamaranthine, betanin and isobetanin) were tentatively identified and quantified. Twenty eight phenolic compounds of four different families (hydroxybenzoic and hydroxycinnamic acids, flavones and flavonols) were separated and characterized on the basis of their accurate MS and MS/MS information out of which ten compounds were confirmed by authentic standards. These plant species could be considered as an especially rich source of natural bioactive compounds and potential food colorants. A. brasiliana showed the highest betacyanin and polyphenols content (89μg/g and 35,243μg/g, respectively). Among polyphenols, flavonols were the more abundant (kaempferol-glucoside, kaempferol-rutinoside and kaempferol-rhamnosyl-rhamnosyl-glycoside). Meanwhile, A. tenella showed a different polyphenols profile with flavones as major compounds (glucopyranosil-vitexin and vitexin). As a novelty, pentosyl-vitexin and pentosyl-isovitexin were detected for the first time in Alternanthera plants. Both A. brasiliana and A. tenella leaves showed high total polyphenol content and in vitro antioxidant activity (FRAP). These results provide an analytical base concerning the phenolic and betalains composition and the antioxidant properties of two members of the promising Alternanthera gender, for subsequent applications, such as functional food ingredients. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Modeling of dual cylinder wind-up extensional rheometers

    DEFF Research Database (Denmark)

    Yu, Kaijia; Marin, Jose; Jensen, Mette

    measurements are useful for polymer characterization. The Sentmanat extensional Rheometer[1] is an new testing platform for the study of polymers and elastomers in extensional flow. This technique employs a dual wind-up drum technique to perform an uni-axial extensional deformation during experiments...

  8. Estudo mineral das espécies vegetais Alternanthera brasiliana (L.) Kuntze e Bouchea fluminensis (Vell) Mold.

    OpenAIRE

    Delaporte, R.H.; Guzen, K.P.; Takemura, O.S.; Mello, J.C.P de

    2005-01-01

    Alternanthera brasiliana e Bouchea fluminensis são plantas encontradas amplamente na América do Sul, sendo utilizada pela população pelas suas propriedades analgésicas e antiinflamatórias. O trabalho objetivou determinar o teor de cinzas totais e os elementos minerais em ambas espécies. O teor de cinzas totais das folhas de A. brasiliana e B. fluminensis foi de 13,23% ± 0,47 e 8,28% ± 0,07, respectivamente. Em relação à presença de macro e micronutrientes nas folhas observou-se uma maior conc...

  9. Extensional tectonics in Mt Parnon (Peloponnesus, Greece)

    Science.gov (United States)

    Skourtsos, Emmanuel; Lekkas, Spyridon

    2011-10-01

    Peloponnesus in the south-western part of the Aegean is formed by a heterogeneous pile of alpine thrust sheets that was reworked by normal faulting from Upper Miocene to recent times. Upper Miocene-Lower Pliocene extension in Mt Parnon was accommodated by several mappable brittle detachment faults that exhibit a top-to-the-NE-ENE sense of shear. The hanging wall of the detachments comprises a number of highly tilted fault blocks containing abundant evidence of intense internal deformation by normal faulting and layer-parallel shearing contemporaneous with faulting. These fault blocks are remnants of a cohesive extensional block that slipped to the NE-ENE and broke up along high-angle normal faults that sole into or are cut by the detachments. The largest part of this block is located at the eastern edge of the metamorphic core forming the hanging wall of East Parnon high-angle normal fault that excised part of the aforementioned detachments. The lowermost metamorphic Unit of the nappe-pile does not seem to be affected by the previous extensional episode. Upper plate reconstruction shows that various units of the nappe-pile were affected by high-angle normal faults that linked to detachment faults in the weaker layers. Since the Middle-Upper Pliocene further exhumation of the metamorphic rocks has resulted in the formation of high-angle normal faults overprinting Neogene extensional structures and cut the entire nappe-pile. This new fault system tilted the earlier extensional structures and produced a NE-SW coaxial deformation of Mt Parnon.

  10. Pharmacological and phytochemical studies of callus culture extracts from Alternanthera brasiliana.

    Science.gov (United States)

    Macedo, A F; Barbosa, N C; Esquibel, M A; Souza, M M; Cechinel-Filho, V

    1999-10-01

    This work describes the establishment of callus cultures of Alternanthera brasiliana, a Brazilian medicinal plant used to treat several ailments. In addition the two extracts, exhibiting best yields, were chemically analysed and evaluated as antinociceptive agents in two classical models of pain in mice: the writhing test and the formalin test. The results show that the highest biomass accumulation was observed in callus grown in media with higher concentrations of growth regulator of 2,4-D. Both extracts studied exhibited antinociceptive effects in mice, being more effective than the plant extracts. The pharmacological action seems to be related to the presence of steroids and/or terpenes.

  11. 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....

  12. Antioxidant activities and triterpenoids isolated from Alternanthera brasiliana (L.) Kuntze leaves.

    Science.gov (United States)

    Pereira, D F; Zanon, R B; Dos Santos, M; Boligon, A A; Athayde, M L

    2013-01-01

    The species Alternanthera brasiliana (L.) Kuntze (Amaranthaceae) is a perennial herbaceous plant widely distributed in Brazil's eastern beaches and certain Amazonian regions. Crude ethanolic (70%) extract, fractions (dichloromethane, ethyl acetate and n-butanolic) and the mixture isolated were investigated regarding their content of total phenolic compounds by Folin-Ciocalteau assay. Total phenolic contents varied from 29.0 to 56.6 mg/g (dry fraction). The scavenging capacity of the extract, fractions and mixture isolated was characterised by the 1,1-diphenyl-2-picrylhydrazyl method. Only ethyl acetate fraction exhibited a modest scavenging capacity (SC50 = 163.00 μg/mL and SC% = 64.29% at 250 μg/mL) in a dose-dependent manner. Crude extract, dichloromethane and butanolic fractions presented a very weak scavenging capacity (SC% ≤ 40% at 250 μg/mL). A correlation between the antioxidant activity and the total phenolic contents could not be observed. The fractionation and purification of dichloromethane fraction evidenced the presence of a mixture of β-sitosterol, stigmasterol and spinasterol, which was identified by NMR methods and compared with literature data. Results of this study demonstrated for the first time the antioxidant activity of A. brasiliana.

  13. 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

    International Nuclear Information System (INIS)

    Macedo, Maria Helena F.; Sa, Emanuel F. Jardim de; Souza, Zorano S.; Mendes, Franklin S.; Ramalho, Karlos A.C.

    1997-01-01

    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

  14. 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.

  15. 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

  16. 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

  17. Distribution and density of the bivalve Anomalocardia brasiliana in the estuarine region of Northeastern Brazil

    Directory of Open Access Journals (Sweden)

    A. M. L. Rodrigues Maia

    2017-06-01

    Full Text Available Abstract The objective of this study was to analyze the density and distribution of the bivalve Anomalocardia brasiliana in beaches in the estuarine region of the semiarid in Rio Grande do Norte State, Barra and Pernambuquinho (04°56.978’S and 37°08.961’W and 04°56.792’S and 37°09.375’W, respectively. Samples were collected monthly during 37 months using five transects (300 m long and 400 m apart laid perpendicularly to the beach line toward the sea. Seven collection points, 50 m apart, were set in each transect, and shellfish and sediment samples were collected. Temperature and salinity were measured in each transect. The results showed a temperature variation of average values of 3 °C; the greatest variation (33.2 °C was observed in May of 2009. The lowest average salinity values were observed between April and June of 2009 (5, 8.7, and 7.8, respectively. This fact was due to an atypical rainfall in the region, which resulted in a large freshwater inflow into the estuary; the average salinity values were about 40 in the remaining months. The highest precipitation values were observed in April/09, April/10, and April/11; the highest precipitation occurred in April/09 (316.3 mm. The lower average densities of A. brasiliana were observed in April and May/09 when compared to the other months; the lowest value was observed in April/09 (26 ind/m2. The highest densities occurred between November/10 and July/11, with values ranging from 70 to 322 ind/m2. The highest inflow of young individuals (lengths from 2 to 5 mm was observed between April and June of 2010 and on September/10 while the highest frequency of adults (from 20 to 25 mm occurred between December of 2010 and April of 2011. Hence, the results of this study show that in the months with the greatest rainfall, salinity and the average density of A. brasiliana showed the lowest values.

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

    International Nuclear Information System (INIS)

    Zacchi, Flávia Lucena; Lima, Daína; Flores-Nunes, Fabrício de; Mattos, Jacó Joaquim; Lüchmann, Karim Hahn; Araújo de Miranda Gomes, Carlos Henrique; Bícego, Márcia Caruso; Taniguchi, Satie; Sasaki, Silvio Tarou; Dias Bainy, Afonso Celso

    2017-01-01

    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 −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 salinity 10

  19. Extending the Extensional Lambda Calculus with Surjective Pairing is Conservative

    DEFF Research Database (Denmark)

    Støvring, Kristian

    2006-01-01

    We answer Klop and de Vrijer's question whether adding surjective-pairing axioms to the extensional lambda calculus yields a conservative extension. The answer is positive. As a byproduct we obtain a "syntactic" proof that the extensional lambda calculus with surjective pairing is consistent....

  20. Entangled Polymer Melts in Extensional Flow

    DEFF Research Database (Denmark)

    Hengeller, Ludovica

    . On the other hand, addition of low-volatility solvents to polymers is also a common industrial practice that others a means for lowering the Tg of the polymers. Moreover industrial polymers present a wide distribution of chain lengths and/or branched architectures that strongly influence their response....... Understanding the behaviour of polymer melts and solutions in complex non-linearflows is crucial for the design of polymeric materials and polymer processes. Through rheological characterization, in shear and extensional flow, of model polymer systems,i.e. narrow molar mass distribution polymer melts......Many commercial materials derived from synthetic polymers exhibit a complex response under different processing operations such as fiber formation, injection moulding,film blowing, film casting or coatings. They can be processed both in the solid or in the melted state. Often they may contain two...

  1. Transient Overshoot Extensional Rheology: Experimental and Numerical Comparisons

    DEFF Research Database (Denmark)

    Hoyle, David; Huang, Qian; Auhl, Dietmar

    in the extensional viscosity. We present a modified Pompom model capable of capturing these overshoots and show finite element simulations of the cross-slot flow using this model. In doing this we show how the overshoot causes the W-cusp and how the shape of the cusps is dependent upon the difference between...... polymer chains, and not having steady state values for the extensional viscosity makes understanding and modelling molecular rheology in extensional flow challenging. Here we present a comparison between tree extensional rheometers: the Sentmanat extensional rheometer (SER), the filament stretching...... the steady state measurements from the FSR to the predictions of the CSER, which measures the viscosity using optical flow induced birefringence techniques. The FSR is capable of measuring a steady state for strain rates less than 0.5/s and the CSER for strain rates typically in the range of 0.1/s to 10/s...

  2. Detection of a chemical cue from the host seaweed Laurencia dendroidea by the associated mollusc Aplysia brasiliana.

    Directory of Open Access Journals (Sweden)

    N Nocchi

    Full Text Available Chemical cues from sessile hosts can attract mobile and associated organisms and they are also impotant to maintain associations and overall biodiversity, but the identity and molecular structures of these chemicals have been little explored in the marine environment. Secondary metabolites are recognized as possible chemical mediators in the association between species of Laurencia and Aplysia, but the identity of the compounds has not been established. Here, for the first time, we experimentally verify that the sesquiterpene (+-elatol, a compound produced by the red seaweed Laurencia dendroidea, is a chemical cue attracting the associated sea hare Aplysia brasiliana. In addition to revealing the nature of the chemical mediation between these two species, we provide evidence of a chemical cue that allows young individuals of A. brasiliana to live in association with L. dendroidea. This study highlights the importance of chemical cues in Laurencia-Aplysia association.

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

    Directory of Open Access Journals (Sweden)

    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.

  4. Caracteres morfo-anatômicos da folha e do caule de Alternanthera brasiliana (L.) O. Kuntze, Amaranthaceae

    OpenAIRE

    Duarte, Márcia do Rocio; Debur, Maria do Carmo

    2004-01-01

    Alternanthera brasiliana (L.) O. Kuntze, Amaranthaceae is a Brazilian perennial herb employed as analgesic and anti-inflammatory in the traditional medicine. This work has analysed the morpho-anatomy of the leaf and stem, in order to supply knowledge to the medicinal plant identification. The botanical material was fixed, freehand sectioned and stained according to usual microtechniques. The leaves are simple, entire, decussate, oval-lanceolate and purple, presenting uniseriate epidermis, plu...

  5. Extremely Shallow Extensional Faulting Near Geothermal Fields

    Science.gov (United States)

    Hudnut, K. W.; Wei, S.; Donnellan, A.; Fielding, E. J.; Graves, R. W.; Helmberger, D. V.; Liu, Z.; Parker, J. W.; Treiman, J. A.

    2013-12-01

    Surface faulting has been discovered in association with a shallow extensional M 4.9 earthquake, the source properties of which have also been studied by modeling of broadband seismic data and geodetic imagery. This M 4.9 and also a M 4.6 shallow normal event occurred late in the Brawley Swarm of August 2012, a dominantly strike-slip sequence with events up to M 5.5 (Hauksson et al., SRL 2013 and Wei et al., GRL 2013). The point source waveform inversions reveal normal mechanisms and centroid depths of ~2.5 km for both events, while the modeling of the geodetic data indicates a compatible depth of ~2.0 km. The M 4.9 event had unusually large (~40 cm) and sudden (~1.0 - 1.5 km/sec) slip, considering its extremely shallow depth. The earlier and larger strike-slip events during the Aug. 2012 swarm were on a left-lateral SW-NE oriented vertical planar cross-fault, whereas the M 4.6 and M 4.9 occurred on a SSW-NNE oriented, west-dipping plane. Airborne imagery obtained using Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) revealed a surface fault rupture that was subsequently confirmed and documented in the field in May 2013. A pre-existing but previously un-mapped fault sustained west-down surface slip of up to 18 × 2 cm along breaks extending ~3.5 km along a NNE orientation, and ruptured beneath and under a railroad track and pipeline (without breaking them). UAVSAR and seismological data were used jointly to image the source properties of the M 4.9 earthquake in detail. Typically, the uppermost few kms of right-lateral faults in the Salton Trough exhibit creep, especially after larger earthquakes, as in 1979 and 1987. On this basis, general models of stable sliding within the uppermost few kms have been developed. In this case, however, the joint inversion indicates that seismic energy was radiated by slip of up to 40 cm on a fault plane extending from the surface to a depth of only ~3 km, extending ~4 km along-strike, and dipping ~45° west, with west

  6. Influence of Alternanthera brasiliana (L.) Kuntze on Altered Antioxidant Enzyme Profile during Cutaneous Wound Healing in Immunocompromised Rats.

    Science.gov (United States)

    Barua, Chandana Choudhury; Ara Begum, Shameem; Talukdar, Archana; Datta Roy, Jayanti; Buragohain, Bhaben; Chandra Pathak, Debesh; Kumar Sarma, Dilip; Saikia Bora, Rumi; Gupta, Asheesh

    2012-01-01

    Alternanthera brasiliana (L.) Kuntze (Amaranthaceae) is a herbaceous plant used against inflammation, cough, and diarrhea in Brazilian popular medicine. In our preliminary study, promising wound healing activity of methanol extract of leaves of A. brasiliana (MEAB) was observed in normal excision and incision wound models. Therefore, the present study was designed to investigate the wound healing activity along with the antioxidant enzyme profile during cutaneous excision immunocompromised wound after topical application of 5% w/w ointment of MEAB in rats. Immunocompromised state was induced by pretreatment with hydrocortisone (HC) at 40 mg/kg body weight (i.m.) in male rats. Following one-week pretreatment with HC, wounds were created. The vehicle, 5% (w/w) ointment of MEAB, or standard drug (Himax) was applied topically twice daily. Healing potential was evaluated by the rate of wound contraction, estimation of enzymatic and nonenzymatic antioxidants like catalase, SOD, GSH, protein, vitamin C, and hydroxyproline content, which was supported by histopathological study on the 8th day following wounding. There was significant increase in the enzymatic and nonenzymatic antioxidant parameters in the extract-reated group as compared to control group. Histopathological study revealed collagen deposition, fibroblast proliferation, angiogenesis, and development of basement membrane in A. brasiliana group. The results of the present investigation revealed significant wound healing activity of MEAB.

  7. Estudo mineral das espécies vegetais Alternanthera brasiliana (L. Kuntze e Bouchea fluminensis (Vell Mold.

    Directory of Open Access Journals (Sweden)

    R.H. Delaporte

    Full Text Available Alternanthera brasiliana e Bouchea fluminensis são plantas encontradas amplamente na América do Sul, sendo utilizada pela população pelas suas propriedades analgésicas e antiinflamatórias. O trabalho objetivou determinar o teor de cinzas totais e os elementos minerais em ambas espécies. O teor de cinzas totais das folhas de A. brasiliana e B. fluminensis foi de 13,23% ± 0,47 e 8,28% ± 0,07, respectivamente. Em relação à presença de macro e micronutrientes nas folhas observou-se uma maior concentração de nitrogênio (3,13% e manganês (0,296% para A. brasiliana e de cálcio (3,08% e ferro (0,256% para B. fluminensis. Os dados obtidos, cinzas totais, macro e microelementos, contribuem significativamente no controle de qualidade e padronização de ambas drogas vegetais, além de dar suporte ao uso como suplemento nutricional.

  8. 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...... is attached onto two drums, followed by a rotation of both drums in opposite direction. The numerical modeling is based on integral constitutive equations of the K-BKZ type. Generally, to ensure a proper uni-axial extensional deformation in dual wind-up drum rheometers the simulations show that a very small...

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

    DEFF Research Database (Denmark)

    Hassager, Ole; Huang, Qian

    Extensional deformation and flow occur in a number of polymer processing operations such as fiber spinning and film blowing. To understand and analyze material behavior in such operations, accurate and quantitative measurements of the rheological properties in well-defined extensional deformations...... are needed. However, while shear flows may in principle easily be generated in geometries such as cone-and-plate and plate-and-plate, the generation of controlled extensional flows has proven to be a challenge [1]. This presentation will focus on the application of Filament Stretching Rheometry (FSR...

  10. A portable and affordable extensional rheometer for field testing

    OpenAIRE

    Hallmark, Bart; Bryan, Matthew; Bosson, E; Butler, S; Hoier, T; Magens, Ole; Pistre, N; Pratt, L; Ward, B-A; Wibberley, S; Wilson, David Ian

    2016-01-01

    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 an...

  11. 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

  12. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. 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

  15. Radiosensitivity of Salmonella spp and Vibrio parahaemolyticus artificially incorporated by oysters (Crassostrea brasiliana)

    International Nuclear Information System (INIS)

    Jakabi, Miyoko

    2001-01-01

    Irradiation is considered one of the most efficient technological process to reduce the number of microorganisms in food. It can be used to improve the safety of food products as well as their shelf life. Oysters are considered one of the most important vehicle of pathogenic bacteria due to their feeding characteristic and because they are usually ingested raw. The aim of this study was to evaluate the influence of gamma radiation process on high levels of Salmonella Enteritidis, Salmonella Infantis and Vibrio parahaemolyticus incorporated by oysters (Crassostrea brasiliana) as well as on the survival of the animals and sensory attributes. The oysters were submitted to gamma radiation treatment ( 60 Co) with doses ranging from 0.5 kGy to 3.0 kGy. At least four trials were conducted for each serotype. The dose of 3.0 kGy was, generally, sufficient to reduce the level of Salmonella serotypes in 6 log while for V.parahaemolyticus the dose as 1.o kGy. Animals were not killed and sensory attributes were not changed by the highest irradiation dose. Therefore, 3.0 kGy is a dose that is effective on the inactivation of Salmonella spp and V.parahaemolyticus in oysters without changing their odour, flavour and appearance. (author)

  16. Toxicity against Drosophila melanogaster and antiedematogenic and antimicrobial activities of Alternanthera brasiliana (L.) Kuntze (Amaranthaceae).

    Science.gov (United States)

    Coutinho, Henrique Douglas Melo; de Morais Oliveira-Tintino, Cícera Datiane; Tintino, Saulo Relison; Pereira, Raimundo Luiz Silva; de Freitas, Thiago Sampaio; da Silva, Maria Arlene Pessoa; Franco, Jeferson Luis; da Cunha, Francisco Assis Bezerra; da Costa, José Galberto Martins; de Menezes, Irwin Rose Alencar; Boligon, Aline Augusti; da Rocha, João Batista Teixeira; Rocha, Maria Ivaneide; Dos Santos, Joycy Francely Sampaio

    2017-06-08

    Bioactive phytocompounds are studied by several bioactivities demonstrated, as their cytotoxic effects. The aim of this work was to evaluate the phytochemical profile, the toxic effect using the Drosophila melanogaster animal model and the anti-inflammatory and antimicrobial effect of the Alternanthera brasiliana (EEAB) ethanol extract. The phytochemical profile was performed using HPLC. The cytotoxic effect was evaluated in vivo using D. melanogaster. The anti-inflammatory effect was determined by neurogenic and antiedematogenic assays, and the antimicrobial activity was assayed using a microdilution method to determine the minimum inhibitory concentration (MIC) of the EEAB alone and in association with antibiotics. The main compound identified on the EEAB was luteolin (1.93%). Its cytotoxic effect was demonstrated after 24 h in the concentrations of 10, 20 and 40 mg/mL. The extract demonstrated an antiedematogenic effect, with a reduction of the edema between 35.57 and 64.17%. The MIC of the extract was ≥1.024 μg/mL, thus being considered clinically irrelevant. However, when the EEAB was associated with gentamicin, a synergism against all bacterial strains assayed was observed: Staphylococcus aureus (SA10), Escherichia coli (EC06) and Pseudomonas aeruginosa (PA24). Due to these results, the EEAB demonstrated a low toxicity in vivo and anti-inflammatory and synergistic activities. These are promising results, mainly against microbial pathogens, and the compounds identified can be a source of carbon backbones for the discovery and creation of new drugs.

  17. 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/.

  18. A portable and affordable extensional rheometer for field testing

    International Nuclear Information System (INIS)

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

    2016-01-01

    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/. (paper)

  19. 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.

  20. Produção de mudas de penicilina (Alternanthera brasiliana (L. Kuntze via estaquia

    Directory of Open Access Journals (Sweden)

    V. Tracz

    2014-01-01

    Full Text Available A penicilina (Alternanthera brasiliana (L. Kuntze, pertence à família Amaranthaceae e tem sido reconhecida por suas propriedades anti-inflamatória, analgésica, e antiviral. O trabalho teve como objetivo avaliar a concentração de ácido indolbutírico (AIB mais adequada para a indução do enraizamento de estacas da penicilina. Foram selecionados ramos herbáceos de plantas matrizes, coletadas em novembro de 2010, para confecção de estacas com 6 cm de comprimento e 2 folhas apicais. As estacas foram desinfestadas através de solução de hipoclorito de sódio (0,5% por 15 minutos. Em seguida, as estacas da penicilina tiveram suas bases imersas por 10 segundos em soluções de AIB nas concentrações de 0, 250, 500, 750 ou 1000 mg L-1, e foram plantadas em tubetes, sob irrigação em casa de vegetação. O delineamento experimental foi inteiramente casualizado, com 80 estacas por tratamento. Após 30 dias não foram observados resultados com diferenças significativas entre os tratamentos utilizados quanto ao enraizamento, crescimento das raízes, mortalidade, massa fresca e seca. No entanto, houve aumento do número de raízes das estacas tratadas nas concentrações mais altas de AIB (750 e 1000 mg L-1 quando comparadas ao controle e aos demais tratamentos. As porcentagens de enraizamento foram acima de 94% para essa espécie, podendo concluir que a propagação via estaquia é viável sem o uso de reguladores para induzir a formação de raízes dessa espécie, a qual pode ser considerada de fácil enraizamento.

  1. Anxiolytic and anticonvulsant activity of methanol extract of leaves of Alternanthera brasiliana (L.) Kuntze (Amaranthaceae) in laboratory animals.

    Science.gov (United States)

    Barua, Chandana C; Begum, Shameem A; Barua, Acheenta G; Borah, Rumi S; Lahkar, Mangala

    2013-06-01

    Anxiety related disorders are the most common mental illnesses and major cause of disability in man. Anxiolytic activity of methanol extract of leaves of A. brasiliana (L.) Kuntze (MEAB) was evaluated using hole board (HB), open field (OF), elevated plus maze (EPM) and light/dark exploration test (LDE) in mice. Its locomotor activity was studied using actophotometer and anticonvulsant effect was studied using maximal electroshock-induced seizures and pentylenetetrazole-induced seizures in mice. Single oral administration of MEAB at different doses (100, 300 and 600 mg/kg, ip) significantly increased the number and duration of head poking in the HB test; rearing, assisted rearing and number of square traveled in the OF test; entries and time spent in open arm in the EPM test; time spent in lighted box, and numbers of crossings and transfer latency time in the LDE test. There was significant reduction in the time spent in close arm in the EPM test and time spent in dark box in LDE test. In the actophotometer, the activity count was reduced in MEAB and diazepam treated group than control group. All the three doses of the extract significantly reduced the duration of seizures induced by pentylenetetrazole (chemoshock convulsion). However, the extract did not show any appreciable effect in electroshock convulsion model. The results of the present study suggest promising anxiolytic and anticonvulsant activity of MEAB which might be accredited to different phytoconstituents like alkaloids, steroids and triterpenes present in the methanol extract of A. brasiliana.

  2. Health promoting properties of Alternanthera brasiliana leaves and Hibiscus sabdariffa calyces used in fortification of maize-bambara groundnut malt and maize-cowpea malt complementary foods

    Directory of Open Access Journals (Sweden)

    Attaugwu, R.N.

    2017-06-01

    Full Text Available The study evaluated the chemical and antioxidant properties of Alternanthera brasiliana leaves and Hibiscus sabdariffa calyces used in iron and zinc fortification of maizebambara groundnut malt and maize-cowpea malt complementary foods. A. brasiliana leaves and H. sabdariffa calyces were freshly harvested, dried at 50oC for 48 hours and analyzed for the relevant chemical components and antioxidant activities. The vitamin A content was 6996 and 745.6 μgRE/kg while the vitamin C was 238.26 and 294.78 mg/kg respectively. The aqueous extracts of A. brasiliana and H. sabdariffa calyces contained 509.5 mg/kg and 5234.72 mg/kg of alkaloids, 1545 mg/kg and 384 mg/kg of anthocyanins, 767.3 and 235.83 mg/kg of carotenoids, 14,702.8 and 26,428.3 mg/kg of phenols, 1043.5 and 897.63 mg/kg steroids and 462.0 mg/kg and 1006.5 mg/kg of flavonoids respectively. A. brasiliana and H. sabdariffa extracts had concentration-dependent DPPH activity with IC50 of 1.76 mg/ml and 5.745 mg/ml, nitric oxide scavenging activity with IC50 of 0.675 mg/ml and 3.976 mg/ml while the ferric reducing power had an absorbance range of 0.5 – 0.982 and 0.959 – 0.986 respectively. The study revealed that A.brasiliana leaves and H. sabdariffa calyces contain components that will impact positively on the health of the infants when used to formulate complementary foods.

  3. 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...

  4. Rheology of dense granular suspensions under extensional flow

    Science.gov (United States)

    Cheal, Oliver; Ness, Christopher

    2018-03-01

    We study granular suspensions under a variety of extensional deformations and simple shear using numerical simulations. The viscosity and Trouton's ratio (the ratio of extensional to shear viscosity) are computed as functions of solids volume fraction $\\phi$ close to the limit of zero inertia. Suspensions of frictionless particles follow a Newtonian Trouton's ratio for $\\phi$ all the way up to $\\phi_0$, a universal jamming point that is independent of deformation type. In contrast, frictional particles lead to a deformation-type-dependent jamming fraction $\\phi_m$, which is largest for shear flows. Trouton's ratio consequently starts off Newtonian but diverges as $\\phi\\to\\phi_m$. We explain this discrepancy in suspensions of frictional particles by considering the particle arrangements at jamming. While frictionless particle suspensions have a nearly isotropic microstructure at jamming, friction permits more anisotropic contact chains that allow jamming at lower $\\phi$ but introduce protocol dependence. Finally, we provide evidence that viscous number rheology can be extended from shear to extensional deformations, with a particularly successful collapse for frictionless particles. Extensional deformations are an important class of rheometric flow in suspensions, relevant to paste processing, granulation and high performance materials.

  5. Crystallinity of polyethylene in uni-axial extensional flow

    DEFF Research Database (Denmark)

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

    Flow history of polymer melts in processing greatly influences the crystallinity and hence the solid properties of the final material. A wide range of polymer processes involve extensional flows e.g. fiber spinning, blow moulding etc. However, due to instrumental difficulties, experimental studies......, hence much can be learned from studying polymers in extension. Recent advances in filament stretching rheometry now enable the performance of controlled uniaxial stretching of polymeric liquids even to high Hencky strains [1]. In addition the instrument allows for quenching at specific strains...... 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...

  6. 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

  7. Meso-cenozoic extensional tectonics and uranium metallogenesis in southeast China

    International Nuclear Information System (INIS)

    Chen Yuehui; Chen Zuyi; Cai Yuqi; Fu Jin; Feng Quanhong; Shi Zuhai

    1998-12-01

    Through a systematic study on Meso-Cenozoic extensional tectonics in Southeast China, the authors point out that there are three major types of extensional tectonics such as taphrogenic thermo-upwelling, and gravitational extensional tectonics. The characteristics of structural forms, combination patterns, movement style and syn-tectonic magmatism of different extensional tectonics are studied. Then according to the known isotope age data of uranium mineralizations in the area, the relations between the process of extensional tectonics and regional uranium metallogenesis, as well as the corresponding relations in space and time between extensional tectonics and uranium deposits of different types are analyzed. In conclusion, the authors suggest that the uranium mineralizations of different types in Southeast China are characterized by an united ore-forming mechanism due to the apparent control of extensional tectonics to the regional uranium metallogenesis

  8. 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.

  9. Bioaccumulation and elimination of 60 Co and 137 Cs by Anomalocardia brasiliana (Gmelin, 1791) (Mollusca bivalvia). Remobilization of 60 Co, retained in marine sediment by microbial activity

    International Nuclear Information System (INIS)

    Mayr, L.M.

    1984-05-01

    It was studied the capacity of a bi valve mollusc Anomalocardia brasiliana, which lives in the local bottom sediment, to remobilize 60 Co previously sorbed in the sediment. Laboratory experiments demonstrated that the transference of 60 Co from the sediment to the animal was insignificant (bioaccumulation factor (BF) of the order of 10 -3 ). At the same time, the capacity of microorganisms, present in the bottom sediment, to remobilize 60 Co was studied. The results showed that this via of transference was important, considering the much greater microorganism biomass in relation to the biomass of bentonic organisms, as a whole. For 137 Cs the determined BF from water to the animal was 2.2. and, as in the case of 60 Co, the soft tissues concentrated more 137 Cs than shell. Remaining viscera showed the highest BFs. In another series of experiments, the loss of 60 Co or 137 Cs, previously accumulated by A. brasiliana, was followed in aquaria with or without sediment and the respective biological half-lives were calculated. Soft tissues retained 60 Co longer (biological half-life = 117 days) than shells, whereas for 137 Cs the opposite was observed and shells showed a biological half life of 38.5 days. The low values of 60 Co and 137 Cs BF S do not allow to classify A. brasiliana as good biological indicator for pollution by there radionuclides. However since A brasiliana is consumed by the local population and is commercialized to other areas, it was recommended that its contamination by 60 Co or 137 Cs should be monitored. (author)

  10. Cenozoic extensional tectonics of the Western Anatolia Extended Terrane, Turkey

    International Nuclear Information System (INIS)

    Cemen, I; Catlos, E J; Gogus, O; Diniz, E; Hancer, M

    2008-01-01

    The Western Anatolia Extended Terrane in Turkey is located on the eastern side of the Aegean Extended Terrane and contains one of the largest metamorphic core complexes in the world, the Menderes massif. It has experienced a series of continental collisions from the Late Cretaceous to the Eocene during the formation of the Izmir-Ankara-Erzincan suture zone. Based our field work and monazite ages, we suggest that the north-directed postcollisional Cenozoic extension in the region is the product of three consecutive stages, triggered by three different mechanisms. The first stage was initiated about 30 Ma ago, in the Oligocene by the Orogenic Collapse the thermally weakened continental crust along the north-dipping Southwest Anatolian shear zone. The shear zone was formed as an extensional simple-shear zone with listric geometry at depth and exhibits predominantly normal-slip along its southwestern end. But, it becomes a high-angle oblique-slip shear zone along its northeastern termination. Evidence for the presence of the shear zone includes (1) the dominant top to the north-northeast shear sense indicators throughout the Menderes massif, such as stretching lineations trending N10E to N30E; and (2) a series of Oligocene extensional basins located adjacent to the shear zone that contain only carbonate and ophiolitic rock fragments, but no high grade metamorphic rock fragments. During this stage, erosion and extensional unroofing brought high-grade metamorphic rocks of the Central Menderes massif to the surface by the early Miocene. The second stage of the extension was triggered by subduction roll-back and associated back-arc extension in the early Miocene and produced the north-dipping Alasehir and the south-dipping Bueyuek Menderes detachments of the central Menderes massif and the north-dipping Simav detachment of the northern Menderes massif. The detachments control the Miocene sedimentation in the Alasehir, Bueyuek Menderes, and Simav grabens, containing high

  11. Cenozoic extensional tectonics of the Western Anatolia Extended Terrane, Turkey

    Energy Technology Data Exchange (ETDEWEB)

    Cemen, I; Catlos, E J [Boone Pickens School of Geology, Oklahoma State University, 105 Noble Research Center, Stillwater OK 74078 (United States); Gogus, O [University of Toronto, Department of Geology, Earth Sciences Centre, 22 Russell St. Toronto, Ontario, M5S 3B1 (Canada); Diniz, E [Occidental Oil and Gas Corporation, PO Box 22757, Houston TX 77227 (United States); Hancer, M [Pamukkale Universitesi, Muhendislik Fakultesi, Jeoloji Muh. Bolmu, Denizli, 20070 Turkey (Turkey)], E-mail: icemen@okstate.edu

    2008-07-01

    The Western Anatolia Extended Terrane in Turkey is located on the eastern side of the Aegean Extended Terrane and contains one of the largest metamorphic core complexes in the world, the Menderes massif. It has experienced a series of continental collisions from the Late Cretaceous to the Eocene during the formation of the Izmir-Ankara-Erzincan suture zone. Based our field work and monazite ages, we suggest that the north-directed postcollisional Cenozoic extension in the region is the product of three consecutive stages, triggered by three different mechanisms. The first stage was initiated about 30 Ma ago, in the Oligocene by the Orogenic Collapse the thermally weakened continental crust along the north-dipping Southwest Anatolian shear zone. The shear zone was formed as an extensional simple-shear zone with listric geometry at depth and exhibits predominantly normal-slip along its southwestern end. But, it becomes a high-angle oblique-slip shear zone along its northeastern termination. Evidence for the presence of the shear zone includes (1) the dominant top to the north-northeast shear sense indicators throughout the Menderes massif, such as stretching lineations trending N10E to N30E; and (2) a series of Oligocene extensional basins located adjacent to the shear zone that contain only carbonate and ophiolitic rock fragments, but no high grade metamorphic rock fragments. During this stage, erosion and extensional unroofing brought high-grade metamorphic rocks of the Central Menderes massif to the surface by the early Miocene. The second stage of the extension was triggered by subduction roll-back and associated back-arc extension in the early Miocene and produced the north-dipping Alasehir and the south-dipping Bueyuek Menderes detachments of the central Menderes massif and the north-dipping Simav detachment of the northern Menderes massif. The detachments control the Miocene sedimentation in the Alasehir, Bueyuek Menderes, and Simav grabens, containing high

  12. Cenozoic extensional tectonics of the Western Anatolia Extended Terrane, Turkey

    Science.gov (United States)

    Çemen, I.; Catlos, E. J.; Gogus, O.; Diniz, E.; Hancer, M.

    2008-07-01

    The Western Anatolia Extended Terrane in Turkey is located on the eastern side of the Aegean Extended Terrane and contains one of the largest metamorphic core complexes in the world, the Menderes massif. It has experienced a series of continental collisions from the Late Cretaceous to the Eocene during the formation of the Izmir-Ankara-Erzincan suture zone. Based our field work and monazite ages, we suggest that the north-directed postcollisional Cenozoic extension in the region is the product of three consecutive stages, triggered by three different mechanisms. The first stage was initiated about 30 Ma ago, in the Oligocene by the Orogenic Collapse the thermally weakened continental crust along the north-dipping Southwest Anatolian shear zone. The shear zone was formed as an extensional simple-shear zone with listric geometry at depth and exhibits predominantly normal-slip along its southwestern end. But, it becomes a high-angle oblique-slip shear zone along its northeastern termination. Evidence for the presence of the shear zone includes (1) the dominant top to the north-northeast shear sense indicators throughout the Menderes massif, such as stretching lineations trending N10E to N30E; and (2) a series of Oligocene extensional basins located adjacent to the shear zone that contain only carbonate and ophiolitic rock fragments, but no high grade metamorphic rock fragments. During this stage, erosion and extensional unroofing brought high-grade metamorphic rocks of the Central Menderes massif to the surface by the early Miocene. The second stage of the extension was triggered by subduction roll-back and associated back-arc extension in the early Miocene and produced the north-dipping Alaşehir and the south-dipping Büyük Menderes detachments of the central Menderes massif and the north-dipping Simav detachment of the northern Menderes massif. The detachments control the Miocene sedimentation in the Alaşehir, Büyük Menderes, and Simav grabens, containing high

  13. Influence of extensional stress overshoot on crystallization of LDPE

    DEFF Research Database (Denmark)

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

    2017-01-01

    Low-density polyethylene (LDPE) shows a stress overshoot in start-up of strong uniaxial extensional flows of constant rate. It is believed that the overshoot is caused by a contraction of the polymer backbone due to alignment of the long chain branchesthe consequence being that the molecular...... that the overshoot indeed is reflected in the orientation of the crystalline domains of the quenched filaments. In a broader perspective, we show that the final crystalline morphology is determined by the stress at quenchnot the strain at quench. With these findings we confirm that the much debated overshoot has...

  14. Extensiones al meta-modelo UML desarrollando nuevos estereotipos

    OpenAIRE

    Riesco, Daniel Eduardo

    2002-01-01

    UML es un lenguaje universal de modelado de aplicaciones orientadas a objetos que cubre un amplio rango de dominios. Sin embargo, ningún paradigma es suficiente para expresar claramente todas las vistas de los dominios posibles en le mundo. Por ello, se han hecho muchas extensiones a UML que reflejan dominios específicos. En el estándar del OMG (Object Management Group) se proveen tres mecanismos para extender el meta-modelo UML: valores etiquetados, restricciones y estereotipos. Est...

  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. Characters of the leaf and stem morpho-anatomy of Alternanthera brasiliana (L. O. Kuntze, Amaranthaceae Caracteres morfo-anatômicos da folha e do caule de Alternanthera brasiliana (L. O. Kuntze, Amaranthaceae

    Directory of Open Access Journals (Sweden)

    Márcia do Rocio Duarte

    2004-03-01

    Full Text Available Alternanthera brasiliana (L. O. Kuntze, Amaranthaceae is a Brazilian perennial herb employed as analgesic and anti-inflammatory in the traditional medicine. This work has analysed the morpho-anatomy of the leaf and stem, in order to supply knowledge to the medicinal plant identification. The botanical material was fixed, freehand sectioned and stained according to usual microtechniques. The leaves are simple, entire, decussate, oval-lanceolate and purple, presenting uniseriate epidermis, pluricellular non-glandular trichomes coated by papillose cuticle, anomocytic and diacytic stomata on both surfaces; the mesophyll is dorsiventral, with collateral vascular bundles and druses. The stem, in secondary growth, has the dermal system similar to the leaf; the angular collenchyma alternates with the chlorenchyma; it occurs druses and a cambial variant, consisting of concentrical arcs of extra-cambia outside the first cambium and aligned vascular bundles in the pith.Alternanthera brasiliana (L. O. Kuntze, Amaranthaceae, é herbácea perene de origem brasileira, empregada como analgésico e antiinflamatório na medicina tradicional. Este trabalho analisou a morfo-anatomia de folha e caule, a fim de fornecer subsídios à identificação da planta medicinal. O material foi fixado, seccionado à mão livre e corado de acordo com técnicas usuais. As folhas são simples, inteiras, decussadas, oval-lanceoladas e púrpuras, e apresentam epiderme unisseriada, tricomas tectores pluricelulares revestidos por cutícula papilosa, estômatos anomocíticos e diacíticos em ambas as faces; o mesofilo é dorsiventral, com feixes vasculares colaterais e drusas. O caule, em estrutura secundária, tem o sistema de revestimento similar ao da folha; o colênquima é angular em alternância com o clorênquima, ocorrem drusas e uma organização cambial variante, consistindo de arcos cambiais extranumerários concêntricos ao primeiro câmbio vascular e feixes vasculares

  17. Dispersion of extensional waves in fluid-saturated porous cylinders at ultrasonic frequencies

    International Nuclear Information System (INIS)

    Berryman, J.G.

    1983-01-01

    Ultrasonic dispersion of extensional waves in fluid-saturated porous cylinders is studied by analyzing generalized Pochhammer equations derived using Biot's theory. Cases with open-pore surface and closed-pore surface boundary conditions are considered. For both cases, the dispersion of the fast extensional wave does not differ much qualitatively from the dispersion expected for extensional waves in isotropic elastic cylinders. A slow extensional wave propagates in the case with a closed-pore surface but not in the case with an open-pore surface. The propagating slow wave has very weak dispersion and its speed is always lower than, but close to, the bulk slow wave speed

  18. 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

  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. 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...

  1. Reproductive cycle of Anomalocardia brasiliana (Mollusca: Bivalvia: Veneridae) in the estuary of the Cachoeira River, Ilhéus, Bahia.

    Science.gov (United States)

    Luz, J R; Boehs, G

    2011-08-01

    The aim of this study was to characterize the reproductive cycle of Anomalocardia brasiliana, typical of the estuarine region of the Cachoeira River, Ilhéus, Bahia, Brazil. For this purpose, 20 specimens were collected biweekly between August 2005 and August 2006 on an intertidal bank (14º 48' 23" S and 39º 02' 47" W). The animals were measured on the anteroposterior axis (length), examined macroscopically and removed from the shell and fixed in Davidson's solution. Subsequently, the tissues were impregnated in paraffin, cut into 7 mm sections and stained with Harris hematoxylin and eosin (HE). The slides were examined under a light microscope. The water temperature at the site ranged from 24 to 30.5 ºC (mean: 27.4 ºC; SD ± 1.9), salinity from zero to 23 (mean: 13.7; SD ± 7.5) and rainfall from 28.3 mm to 248.8 mm monthly (yearly mean: 130 mm). The sample (n = 478) showed a sex ratio (M: F) of 1: 1.2 (p < 0.05) and no cases of hermaphroditism. There was no sexual dimorphism. Males and females showed reproductive synchrony. The reproductive cycle was continuous, with releases of gametes mainly in spring, summer and autumn. These results are similar to those found in other regions, but there was no reproductive rest period as reported for populations in higher latitudes.

  2. Structural studies of the 'Aplysia Brasiliana' and 'Dermochelis Coriacea' myoglobins by optical and electron paramagnetic resonance techniques

    International Nuclear Information System (INIS)

    Baffa Filho, O.

    1984-01-01

    The myoglobins of 'Applysia Brasiliana' (MbApB) and of the sea turtle 'Dermochelis Coriacea' (MbT) are studied with special attention devoted to the acid-alkalyne transition (AAT), the interaction with transition metals and temperature induced conformational changes in order to characterize structural differences in these proteins. The AAT of MbApB has a pK = 7.2 obtained from the EPR spectra of Fe 3+ at g (perpendicular) = 5.83 and a pK = 7.5 obtained from optical absorption (lambda = 590 nm). The EPR Spectrum of Fe 3+ at alkalyne pH shows a rhombic distortion of the ion crystal field which is in agreement with the absence in this protein of the distal histidine residue. The ESR lines associated with the low spin configuration are considerably broadened. This effect can be explained by fluctuations on the heme position relative to the symmetry axis. MbApB forms complexes with both Cu 2+ and Mn 2+ only one binding site is obtained for both metals in the protein. This site probably has common ligands for mN 2+ and Cu 2+ as the binding is competitive, suggesting also the at the Cu 2+ complex is more stable than the Mn 2+ one (K sub(A) sup(M) sub(n 2+ )) = (11,5 + - 0,8).10 3 M -1 . (Author) [pt

  3. Evaluation of antitumor activity and antioxidant status of Alternanthera brasiliana against Ehrlich ascites carcinoma in Swiss albino mice.

    Science.gov (United States)

    Samudrala, Pavan Kumar; Augustine, Bibin Baby; Kasala, Eshvendar Reddy; Bodduluru, Lakshmi Narendra; Barua, Chandana; Lahkar, Mangala

    2015-01-01

    The main objective of the present study was to explore the antitumor activity of the ethyl acetate extract of the Alternanthera brasiliana (EAAB) and its antioxidant status against Ehrlich ascites carcinoma (EAC) in Swiss albino mice. Based on the preliminary in vitro cytotoxicity studies, EAAB was selected for anti-tumor and antioxidant effects. Anticancer activity of EAAB was evaluated against EAC in Swiss albino mice at the doses of 200 and 400 mg/kg. EAAB was administered for 14 consecutive days after induction of cancer. After 24 h of the last dose and 18 h of fasting, half of the mice were sacrificed and rest were kept alive for assessing any increase in life span. The antitumor effect of EAAB was assessed by evaluating tumor volume, viable and nonviable tumor cell count, tumor weight, hematological and biochemical parameters of EAC bearing host. Furthermore, the antioxidant and histopathological parameters were evaluated. EAAB treatment has shown significant decrease in tumor volume, viable cell count, tumor weight and elevated the life span of EAC tumor bearing mice in a dose dependent manner. In hematological profile count of RBC, hemoglobin, and WBC were found reverted to normal. EAAB also significantly decreased the levels of lipid peroxidation and significantly increased the levels of GSH, SOD and Catalase. From the above results it may be concluded that EAAB has potent dose dependent antitumor activity and is comparable to that of 5-flourouracil.

  4. Óleos essenciais das folhas de Vernonia Remotiflora e Vernonia Brasiliana: composição química e atividade biológica

    OpenAIRE

    Maia,Ana Isabel V.; Torres,Maria Conceição M.; Pessoa,Otília Deusdênia L.; Menezes,Jane Eire S. A. de; Costa,Sônia Maria O.; Nogueira,Vanessa Lúcia R.; Melo,Vânia Maria Maciel; Souza,Elnatan B. de; Cavalcante,Maria Gilvânia B.; Albuquerque,Maria Rose Jane R.

    2010-01-01

    The chemical composition of the essential oils, obtained by hidrodistillation, from leaves of two Vernonia species (V. remotiflora and V. brasiliana), was determined by GC-FID and GC-MS. Both essential oils were predominantly constituted by sesquiterpenes (92.0 - 93.4%). The main constituents of the oil from V. brasilana were (E)-caryophyllene (36.7%), germacrene D (35.5%), and α-humulene (11.7%), while (E)-caryophyllene (42.2%) and bicyclogermacrene (20.0%) were the major ones in the oi...

  5. The Aegean/Cycladic and the Basin and Range Extensional Provinces - A Tectonic and Geochronologic Perspective

    Science.gov (United States)

    Stockli, D. F.

    2017-12-01

    The Aegean/Cycladic region (AC) and the Basin and Range Province (B&R) are two of the most famous Cenozoic extensional provinces and have greatly influenced our thinking about syn-convergent back-arc extension, core complex formation, syn-extensional magmatism, and kinematic transitions. They share numerous tectonic and structural similarities, such as a syn-convergent setting, previous contractional deformation, and core complex formation, but fundamental geological ambiguities remain, mainly centering around timing. The B&R affected a previously contractional belt (Sevier) and voluminous continental magmatic arc that created a pre-extensional orogenic highland. Extension was long-lived and complex, driven by both gravitational collapse and temporally distinct kinematic boundary condition changes. The B&R was also affected by massive, largely pre-extensional regional magmatic flare-ups that modified both the thermal and crustal composition. As the B&R occupies an elevated interior plateau, syn-extensional basin deposits are exclusively continental in character. In contrast, the AC is a classic marine back-arc extensional province that affected an active subduction margin with numerous accreted oceanic and continental ribbons, exhuming an early Cenozoic HP-LT subduction complex. Exhumation of the HP-LT complex, however, was accommodated both by vertical extrusion and crustal extension. Late Cenozoic extensional faulting was contemporaneous with S-ward sweeping arc magmatism and affected by little to no kinematic changes. As both the AC and B&R experienced contractional deformation during K-Cz subduction and J-K shortening, respectively, it is critical to differentiate between contractional and extensional structures and fabrics. The lack of temporal constraints hampers the reconstructions of pre-extensional structural anatomies and extensional strain magnitudes or even the attribution of structures to specific geodynamic settings. Novel methodologies in

  6. 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.

  7. 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.

  8. Shear History Extensional Rheology Experiment: A Proposed ISS Experiment

    Science.gov (United States)

    Hall, Nancy R.; Logsdon, Kirk A.; Magee, Kevin S.

    2007-01-01

    The Shear History Extensional Rheology Experiment (SHERE) is a proposed International Space Station (ISS) glovebox experiment designed to study the effect of preshear on the transient evolution of the microstructure and viscoelastic tensile stresses for monodisperse dilute polymer solutions. Collectively referred to as Boger fluids, these polymer solutions have become a popular choice for rheological studies of non-Newtonian fluids and are the non-Newtonian fluid used in this experiment. The SHERE hardware consists of the Rheometer, Camera Arm, Interface Box, Cabling, Keyboard, Tool Box, Fluid Modules, and Stowage Tray. Each component will be described in detail in this paper. In the area of space exploration, the development of in-situ fabrication and repair technology represents a critical element in evolution of autonomous exploration capability. SHERE has the capability to provide data for engineering design tools needed for polymer parts manufacturing systems to ensure their rheological properties have not been impacted in the variable gravity environment and this will be briefly addressed.

  9. Simulation of lipid vesicle breakup in extensional flows*

    Science.gov (United States)

    Banton, Rohan; Eggleton, Charles

    2001-11-01

    Lipid molecules in solution can spontaneously form vesicles encapsulating the solvent. Vesicles can be used to manufacture artificial cells and as a novel means of drug delivery. Unlike biological cells, vesicles do not possess a cytoskeleton (scaffolding for structural rigidity) and cannot resist in-plane shearing forces. The Evans-Skalak strain energy function is used to model the interfacial stresses in the vesicles due to deformation using measured values of the area dilatational and bending moduli. An understanding of vesicle breakup in fluid flow is required in order to effectively design vesicles for particular applications. The Boundary Integral Method is employed to simulate the deformation of the model membrane in both uniaxial and bi-axial extensional flows. The flow field is characterized by a capillary number based on the area dilatational modulus of the vesicle. The response of an initially spherical vesicle to the external flow field was simulated for internal to external viscosity ratios of 0.1,1,10 and capillary numbers in the approximate range of 0.005-0.025. The perturbation analysis developed by Barthes-Biesel (1980) was adapted to predict the deformation of lipid vesicles and compared to the simulations at small capillary numbers. At large capillary numbers, the break-up of the vesicle is simulated and the critical capillary number is determined.

  10. Propagation of extensional waves in a piezoelectric semiconductor rod

    Directory of Open Access Journals (Sweden)

    C.L. Zhang

    2016-04-01

    Full Text Available We studied the propagation of extensional waves in a thin piezoelectric semiconductor rod of ZnO whose c-axis is along the axis of the rod. The macroscopic theory of piezoelectric semiconductors was used which consists of the coupled equations of piezoelectricity and the conservation of charge. The problem is nonlinear because the drift current is the product of the unknown electric field and the unknown carrier density. A perturbation procedure was used which resulted in two one-way coupled linear problems of piezoelectricity and the conservation of charge, respectively. The acoustic wave and the accompanying electric field were obtained from the equations of piezoelectricity. The motion of carriers was then determined from the conservation of charge using a trigonometric series. It was found that while the acoustic wave was approximated by a sinusoidal wave, the motion of carriers deviates from a sinusoidal wave qualitatively because of the contributions of higher harmonics arising from the originally nonlinear terms. The wave crests become higher and sharper while the troughs are shallower and wider. This deviation is more pronounced for acoustic waves with larger amplitudes.

  11. 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.

  12. AÇÃO ANTI-HELMÍNTICA DO EXTRATO HIDROALCOÓLICO DE Alternanthera sessilis e Alternathera brasiliana EM OVINOS

    Directory of Open Access Journals (Sweden)

    Claudia Faccio Demarco

    2017-01-01

    Full Text Available Avaliou-se a atividade anti-helmíntica do extrato hidroalcoólico de plantas de Alternanthera sessilis e Alternanthera brasiliana em ovinos naturalmente infectados. Para o experimento foram utilizados 30 ovinos e estes foram distribuídos em 3 grupos:  grupo 1: controle, que recebeu 10 mL de água, grupo 2: com 10 mL de solução com concentração de 500 mg/L de extrato de A. brasiliana e grupo 3: com 10 mL de solução com concentração de 500 mg/L de A. sessilis. Os animais receberam o tratamento por via oral durante os dias 1, 2, 3, 4 e 5 e as coletas de fezes para avaliar a carga parasitária foram realizadas nos dias 2, 3, 4, 5, e 7. Os resultados demonstraram que não houve diferença significativa na redução de ovos por grama de fezes, bem como na porcentagem de redução de OPG. Conclui-se que nas condições deste trabalho, os extratos não apresentaram ação anti-helmíntica em ovinos.

  13. 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.

  14. 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.

  15. Evolution and dynamics of the Cenozoic tectonics of the South Balkan extensional system

    OpenAIRE

    Burchfiel, Clark B.; Nakov, R.; Dumurdzanov, Nikola; Papanikolaou, D.; Tzankov, Tzanko; Serafimovski, Todor; King, Robert W.; Kotzev, Valentin; Todosov, Angel; Nurce, Bilbil

    2008-01-01

    The South Balkan extensional system consists of normal faults and associated sedimentary basins within southern Bulgaria, Macedonia, eastern Albania, northern Greece, and northwestern Turkey. Extensional tectonism began during the final convergence across the Vardar, Intra-Pontide, and Izmir-Ankara suture zones, where oceanic regions closed between continental Europe and continental fragments that make up the Pelagonian, Sakar, and western Anatolian tectonic units. Earliest extension of lates...

  16. 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

    generic knowledge about the process in which macromolecular fluidfilaments are extended and stretched and show how the extensional properties are related to theproperties on individual molecules. We combine structural and rheological studies of a series ofmodel polymers with different composition...... and architectures. The project entails synthesizingmodel polymer systems of precisely known molecular architecture, subjecting these materials tocontrolled extensional flows and to measure the molecular deformation under controlled flowsituation by SANS. Neutron contrast is obtained using specific deuterium labeled...

  17. Experimental Investigation of Extensional Deformation of Immiscible Droplets in a Laminar, Converging Flow

    Science.gov (United States)

    Sangli, Aditya; Arispe-Guzman, Marcelo; Armstrong, Connor; Bigio, David

    2017-11-01

    The deformation of an immiscible droplet in an extensional flow has been widely studied by researchers using experimental four-roll mills where the bulk liquid imposes a stagnation extensional deformation on the droplet. However, it is of vital interest to study the behavior of an immiscible droplet in a non-stagnant extensional flow which can be produced using a converging channel. A hyperbolic converging channel was built, which could produce a constant extensional rate in the center of the channel, and deformation of droplets of Castor oil injected in a matrix of Silicone oil was observed. Droplets injected in the center of the channel experienced a pure extensional deformation while the droplets injected at an offset position attained the affine state. The nature of the droplet deformation and the critical Capillary numbers are compared with the four-roll mill experiments. Additional experiments were performed with the initial position of the droplet being vertically off center. Higher strain rates were exhibited compared to the pure extensional flow condition. An analysis of the flow field helps explaining the phenomenon and provides insight into the droplet behavior.

  18. Continental Extensional Tectonics in the Basins and Ranges and Aegean Regions: A Review

    Science.gov (United States)

    Cemen, I.

    2017-12-01

    The Basins and Ranges of North America and the Aegean Region of Eastern Europe and Asia Minor have been long considered as the two best developed examples of continental extension. The two regions contain well-developed normal faults which were considered almost vertical in the 1950s and 1960s. By the mid 1980s, however, overwhelming field evidence emerged to conclude that the dip angle normal faults in the two regions may range from almost vertical to almost horizontal. This led to the discovery that high-grade metamorphic rocks could be brought to surface by the exhumation of mid-crustal rocks along major low-angle normal faults (detachment faults) which were previously either mapped as thrust faults or unconformity. Within the last three decades, our understanding of continental extensional tectonics in the Basins and Ranges and the Aegean Region have improved substantially based on fieldwork, geochemical analysis, analog and computer modeling, detailed radiometric age determinations and thermokinematic modelling. It is now widely accepted that a) Basin and Range extension is controlled by the movement along the San Andreas fault zone as the North American plate moved southeastward with respect to the northwestward movement of the Pacific plate; b) Aegean extension is controlled by subduction roll-back associated with the Hellenic subduction zone; and c) the two regions contain best examples of detachment faulting, extensional folding, and extensional basins. However, there are still many important questions of continental extensional tectonics in the two regions that remain poorly understood. These include determining a) precise amount and percentage of cumulative extension; b) role of strike-slip faulting in the extensional processes; c) exhumation history along detachment surfaces using multimethod geochronology; d) geometry and nature of extensional features in the middle and lower crust; e) the nature of upper mantle and asthenospheric flow; f) evolutions

  19. 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

    2018-02-01

    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.

  20. 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.

  1. 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.

  2. LA CALIDAD EDUCATIVA Y LA SATISFACCIÓN DE LOS ESTUDIANTES EN EXTENSIONES MANABITAS

    OpenAIRE

    Villacís Zambrano, Lilia Moncerrate

    2017-01-01

    THE EDUCATIONAL QUALITY AND THE SATISFACTION OF THE STUDENTS IN MANABITAS EXTENSIONSRESUMENLa presente indagación se desarrolló en tres Extensiones de la Provincia de Manabí (Ecuador), se logró como objetivo explicar la relación entre la calidad de la educación y el grado de satisfacción de los estudiantes en las Extensiones objeto de estudio. En el tratado se utilizaron herramientas cualitativas y cuantitativas, entre las esenciales, se pueden mencionar: el muestreo, las encuestas, modelo Se...

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

    International Nuclear Information System (INIS)

    Papanikolaou, D; Vassilakis, E

    2008-01-01

    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

  4. Extensional Fault Evolution and its Flexural Isostatic Response During Iberia-Newfoundland Rifted Margin Formation

    Science.gov (United States)

    Gómez-Romeu, J.; Kusznir, N.; Manatschal, G.; Roberts, A.

    2017-12-01

    During the formation of magma-poor rifted margins, upper lithosphere thinning and stretching is achieved by extensional faulting, however, there is still debate and uncertainty how faults evolve during rifting leading to breakup. Seismic data provides an image of the present-day structural and stratigraphic configuration and thus initial fault geometry is unknown. To understand the geometric evolution of extensional faults at rifted margins it is extremely important to also consider the flexural response of the lithosphere produced by fault displacement resulting in footwall uplift and hangingwall subsidence. We investigate how the flexural isostatic response to extensional faulting controls the structural development of rifted margins. To achieve our aim, we use a kinematic forward model (RIFTER) which incorporates the flexural isostatic response to extensional faulting, crustal thinning, lithosphere thermal loads, sedimentation and erosion. Inputs for RIFTER are derived from seismic reflection interpretation and outputs of RIFTER are the prediction of the structural and stratigraphic consequences of recursive sequential faulting and sedimentation. Using RIFTER we model the simultaneous tectonic development of the Iberia-Newfoundland conjugate rifted margins along the ISE01-SCREECH1 and TGS/LG12-SCREECH2 seismic lines. We quantitatively test and calibrate the model against observed target data restored to breakup time. Two quantitative methods are used to obtain this target data: (i) gravity anomaly inversion which predicts Moho depth and continental lithosphere thinning and (ii) reverse post-rift subsidence modelling to give water and Moho depths at breakup time. We show that extensional faulting occurs on steep ( 60°) normal faults in both proximal and distal parts of rifted margins. Extensional faults together with their flexural isostatic response produce not only sub-horizontal exhumed footwall surfaces (i.e. the rolling hinge model) and highly rotated (60

  5. Extensional Structures on the Po Valley Side of the Northern Apennines

    Science.gov (United States)

    Bettelli, G.; Vannucchi, P.; Capitani, M.

    2001-12-01

    The present-day tectonics of the Northern Apennines is characterized by extension in the inner Tyrrhenian side and compression in the outer Po Valley-Adriatic side. The boundary separating the two domains, extensional and compressional, is still largely undetermined and mainly based on geophysical data (focal mechanisms of earthquakes). Map-scale extensional structures have been studied only along the Tyrrhenian side of the Northern Apennines (Tuscany), while along the Po Valley-Adriatic area the field studies concentrated on compressional features. A new, detailed field mapping of the Po Valley side of the Northern Apennines carried out in the last ten years within the Emilia Romagna Geological Mapping Program has shown the presence of a large extensional fault crossing the high Bologna-Modena-Reggio Emilia provinces, from the Sillaro to the Val Secchia valleys. This Sillaro-Val Secchia Normal Fault (SVSNF) is NW-SE trending, NE dipping and about 80 km long. The age, based on the younger displaced deposits, is post-Miocene. The SVSNF is a primary regional structure separating the Tuscan foredeep units from the Ligurian Units in the south-east sector of the Northern Apennines, and it is responsible for the exhumation of the Tuscan foredeep units along the Apennine water divide. The sub-vertical, SW-NE trending faults, formerly interpreted as strike slip, are transfer faults associated to the extensional structure. A geological cross-section across the SVSNF testifies a former thickness reduction and lamination of the Ligurian Units, as documented in the field, in the innermost areas of the Bologna-Modena-Reggio Emilia hills, implying the occurrence of a former extensional fault. These data indicate that the NE side of the water divide has already gone under extension reducing the compressional domain to the Po Valley foothills and plain. They can also help in interpreting the complex Apennines kinematics.

  6. 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

    This work analyses the high-strain extensional behavior of long-chain branched polyethylenes, employing two novel extensional rheometer devices, the filament stretching rheometer and the cross-slot extensional rheometer. The filament stretching rheometer uses an active feedback loop to control th...

  7. Inhibition of Neurotoxic Secretory Phospholipases A2 Enzymatic, Edematogenic, and Myotoxic Activities by Harpalycin 2, an Isoflavone Isolated from Harpalyce brasiliana Benth

    Directory of Open Access Journals (Sweden)

    Rafael M. Ximenes

    2012-01-01

    Full Text Available Secretory phospholipases A2 (sPLA2 exert proinflammatory actions through lipid mediators. These enzymes have been found to be elevated in many inflammatory disorders such as rheumatoid arthritis, sepsis, and atherosclerosis. The aim of this study was to evaluate the effect of harpalycin 2 (Har2, an isoflavone isolated from Harpalyce brasiliana Benth., in the enzymatic, edematogenic, and myotoxic activities of sPLA2 from Bothrops pirajai, Crotalus durissus terrificus, Apis mellifera, and Naja naja venoms. Har2 inhibits all sPLA2 tested. PrTX-III (B. pirajai venom was inhibited at about 58.7%, Cdt F15 (C. d. terrificus venom at 78.8%, Apis (from bee venom at 87.7%, and Naja (N. naja venom at 88.1%. Edema induced by exogenous sPLA2 administration performed in mice paws showed significant inhibition by Har2 at the initial step. In addition, Har2 also inhibited the myotoxic activity of these sPLA2s. In order to understand how Har2 interacts with these enzymes, docking calculations were made, indicating that the residues His48 and Asp49 in the active site of these enzymes interacted powerfully with Har2 through hydrogen bonds. These data pointed to a possible anti-inflammatory activity of Har2 through sPLA2 inhibition.

  8. Inhibition of Neurotoxic Secretory Phospholipases A(2) Enzymatic, Edematogenic, and Myotoxic Activities by Harpalycin 2, an Isoflavone Isolated from Harpalyce brasiliana Benth.

    Science.gov (United States)

    Ximenes, Rafael M; Rabello, Marcelo M; Araújo, Renata M; Silveira, Edilberto R; Fagundes, Fábio H R; Diz-Filho, Eduardo B S; Buzzo, Simone C; Soares, Veronica C G; Toyama, Daniela de O; Gaeta, Henrique H; Hernandes, Marcelo Z; Monteiro, Helena S A; Toyama, Marcos H

    2012-01-01

    Secretory phospholipases A(2) (sPLA(2)) exert proinflammatory actions through lipid mediators. These enzymes have been found to be elevated in many inflammatory disorders such as rheumatoid arthritis, sepsis, and atherosclerosis. The aim of this study was to evaluate the effect of harpalycin 2 (Har2), an isoflavone isolated from Harpalyce brasiliana Benth., in the enzymatic, edematogenic, and myotoxic activities of sPLA(2) from Bothrops pirajai, Crotalus durissus terrificus, Apis mellifera, and Naja naja venoms. Har2 inhibits all sPLA(2) tested. PrTX-III (B. pirajai venom) was inhibited at about 58.7%, Cdt F15 (C. d. terrificus venom) at 78.8%, Apis (from bee venom) at 87.7%, and Naja (N. naja venom) at 88.1%. Edema induced by exogenous sPLA(2) administration performed in mice paws showed significant inhibition by Har2 at the initial step. In addition, Har2 also inhibited the myotoxic activity of these sPLA(2)s. In order to understand how Har2 interacts with these enzymes, docking calculations were made, indicating that the residues His48 and Asp49 in the active site of these enzymes interacted powerfully with Har2 through hydrogen bonds. These data pointed to a possible anti-inflammatory activity of Har2 through sPLA(2) inhibition.

  9. Inhibition of Neurotoxic Secretory Phospholipases A2 Enzymatic, Edematogenic, and Myotoxic Activities by Harpalycin 2, an Isoflavone Isolated from Harpalyce brasiliana Benth

    Science.gov (United States)

    Ximenes, Rafael M.; Rabello, Marcelo M.; Araújo, Renata M.; Silveira, Edilberto R.; Fagundes, Fábio H. R.; Diz-Filho, Eduardo B. S.; Buzzo, Simone C.; Soares, Veronica C. G.; Toyama, Daniela de O.; Gaeta, Henrique H.; Hernandes, Marcelo Z.; Monteiro, Helena S. A.; Toyama, Marcos H.

    2012-01-01

    Secretory phospholipases A2 (sPLA2) exert proinflammatory actions through lipid mediators. These enzymes have been found to be elevated in many inflammatory disorders such as rheumatoid arthritis, sepsis, and atherosclerosis. The aim of this study was to evaluate the effect of harpalycin 2 (Har2), an isoflavone isolated from Harpalyce brasiliana Benth., in the enzymatic, edematogenic, and myotoxic activities of sPLA2 from Bothrops pirajai, Crotalus durissus terrificus, Apis mellifera, and Naja naja venoms. Har2 inhibits all sPLA2 tested. PrTX-III (B. pirajai venom) was inhibited at about 58.7%, Cdt F15 (C. d. terrificus venom) at 78.8%, Apis (from bee venom) at 87.7%, and Naja (N. naja venom) at 88.1%. Edema induced by exogenous sPLA2 administration performed in mice paws showed significant inhibition by Har2 at the initial step. In addition, Har2 also inhibited the myotoxic activity of these sPLA2s. In order to understand how Har2 interacts with these enzymes, docking calculations were made, indicating that the residues His48 and Asp49 in the active site of these enzymes interacted powerfully with Har2 through hydrogen bonds. These data pointed to a possible anti-inflammatory activity of Har2 through sPLA2 inhibition. PMID:22899963

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

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Huang, Qian

    2014-01-01

    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......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...... of Kuhn steps, e.g. at least two Kuhn steps. A similar disagreement is observed between blends and pure NMMD melts, both containing the same entanglement number. © 2013 Elsevier B.V....

  11. Prediction of cryogenic cavitation around hydrofoil by an extensional Schnerr-Sauer cavitation model

    Science.gov (United States)

    Sun, T. Z.; Wei, Y. J.; Wang, C.

    2015-12-01

    Developing a robust computational strategy to address the rich physics characteristic involved in the thermodynamic effects on the cryogenic cavitation remains a challenging problem. The objective of this present study is to model the numerical methodology to simulate the cryogenic cavitation by implanting the thermodynamic effects to the Schnerr-Sauer cavitation model, and coupling the energy equation considered the latent heat. For this purpose, cavitating flows are investigated over a three dimensional hydrofoil in liquid hydrogen and nitrogen. Experimental measurements of pressure and temperature are utilized to validate the extensional Schnerr-Sauer cavitation model. Specifically, the further analysis of the cavitation solution with respect to the thermodynamic term is conducted. The results show that the extensional Schnerr-Sauer cavitation model predicts better accuracy to the quasi-steady cavitation over hydrofoil in the two cryogenic fluids.

  12. The mechanism of fracture for entangled polymer liquids in extensional flow

    DEFF Research Database (Denmark)

    Huang, Qian; Yu, Liyun; Skov, Anne Ladegaard

    In uniaxial extensional flow of entangled polymer liquids, different rupture modes may happen, including necking and fracture. Malkin andPetrie [1] proposed a ''master curve'' dividing the flow behavior into four zones based on the stretch rate: (I) Flow zone; (II) Transition zone; (III) Rubbery...... zone; and (IV) Glass-like zone. The master curve shows that steady extensional flow can only be reached in Zone I where thestretch rate is very slow, while rupture happens in Zones II-IV with faster stretch rate. Furthermore, Wang et al. [2-4] reported experimental datathat matches the master curve...... and suggested the mechanism of rupture in Zone III and IV is disentanglement and chain scission, respectively. In this work we measure two groups of entangled polystyrene solutions. In one group the samples have the same entanglement molecular weight (Me) but different number of entanglements (Z...

  13. 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....

  14. Considering too few alternatives: The mental model theory of extensional reasoning.

    Science.gov (United States)

    Chevalley, Thierry; Schaeken, Walter

    2016-01-01

    When solving a simple probabilistic problem, people tend to build an incomplete mental representation. We observe this pattern in responses to probabilistic problems over a set of premises using the conjunction, disjunction, and conditional propositional connectives. The mental model theory of extensional reasoning explains this bias towards underestimating the number of possibilities: In reckoning with different interpretations of the premises (logical rules, mental model theoretical, and, specific to conditional premises, conjunction and biconditional interpretation) the mental model theory accounts for the majority of observations. Different interpretations of a premise result in a build-up of mental models that are often incomplete. These mental models are processed using either an extensional strategy relying on proportions amongst models, or a conflict monitoring strategy. The consequence of considering too few possibilities is an erroneous probability estimate akin to that faced by decision makers who fail to generate and consider all alternatives, a characteristic of bounded rationality. We compare our results to the results published by Johnson-Laird, Legrenzi, Girotto, Legrenzi, and Caverni [Johnson-Laird, P., Legrenzi, P., Girotto, V., Legrenzi, M., & Caverni, J. (1999). Naive probability: A mental model theory of extensional reasoning. Psychological Review, 106, 62-88. doi: 10. 1037/0033-295X.106.1.62], and we observe lower performance levels than those in the original article.

  15. 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

  16. 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.

  17. Probing hydrogen bond interactions in a shear thickening polysaccharide using nonlinear shear and extensional rheology.

    Science.gov (United States)

    Jaishankar, Aditya; Wee, May; Matia-Merino, Lara; Goh, Kelvin K T; McKinley, Gareth H

    2015-06-05

    Mamaku gum is a polysaccharide extracted from the fronds of the black tree fern found in New Zealand. The cooked pith has traditionally been used for various medicinal purposes and as a food source by the Maori people of New Zealand. It has potential applications as a thickener in the food industry and as a palliative for patients with dysphagia. Studies on the shear rheology of Mamaku gum have revealed that the gum exhibits shear thickening at a critical shear rate due to a transition from intra- to inter-molecular chain interactions upon shear-induced chain elongation. In this paper, we demonstrate that these interactions are primarily due to hydrogen bonding. We perform extensional rheology on mixtures of Mamaku gum and urea (a known disruptor of hydrogen bonds) to quantify the nature of these interactions. Capillary Breakup Extensional Rheometry (CaBER) performed on the pure Mamaku gum solutions yield plateau values of the Trouton ratio as high as ∼10(4), showing that the viscoelasticity of the gum in uniaxial elongation is much higher than in shear. For all Mamaku concentrations tested, the extensional viscosity decreases upon increasing urea concentration. Furthermore, the relaxation time decreases exponentially with increasing urea concentration. This exponential relationship is independent of the Mamaku concentration, and is identical to the relationships between urea concentration and characteristic timescales measured in nonlinear shear rheology. We show using the sticky reptation model for polymers with multiple sticker groups along the backbone how such a relationship is consistent with a linear decrease in the free energy for hydrogen bond dissociation. We then demonstrate that a time-concentration superposition principle can be used to collapse the viscoelastic properties of the Mamaku-gum/urea mixtures. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Extensional ductile tectonics of the Sioule metamorphic series (Variscan French Massif Central)

    Science.gov (United States)

    Faure, M.; Grolier, J.; Pons, J.

    1993-09-01

    In the Northern part of the Variscan French Massif Central, the Sioule series, from top to bottom, consists of a pre-Viséan granite, migmatite, gneiss and mica schist. Two ductile deformations have been recognized. The earlier phase is characterized by a north-east-south-west trending stretching lineation; the second phase, characterized by a north-west-south-east trending mineral, stretching and crenulation lineation, is better marked in the lower mica schist part than in the upper granito-gneissic part. This second phase occurred during retrogression of the metamorphic rocks; related shear criteria indicate a top to the south-west shear. The Namurian-Westphalian magmatic bodies such as the Echassières leucogranite, Pouzol-Servant microgranite and numerous north-east -south-west trending microgranite dykes are emplaced in extensional fractures related to the same north-west-south-east maximum stretching direction. The asymmetrical shapes of the two granitic massifs indicate that they intruded towards the south-east. The synkinematic retrogression of the metamorphic rocks, the shape of the magmatic bodies and a re-examination of the numerous available data support the interpretation that the deformation is due to the extensional tectonic regime related to the Variscan crustal re-quilibration. This interpretation is in agreement with the correlation of the Sioule series with the Chavanon series. The two series belong to a unique tectono-metamorphic unit left-laterally offset by the Stephanian motion of the Sillon Houiller fault. This study also shows that the Sillon Houiller did not play a significant part during the Namurian-Westphalian extensional tectonics of the Massif Central.

  19. Using extensional flow to reveal diverse aggregation landscapes for three IgG1 molecules.

    Science.gov (United States)

    Willis, Leon F; Kumar, Amit; Dobson, John; Bond, Nicholas J; Lowe, David; Turner, Richard; Radford, Sheena E; Kapur, Nikil; Brockwell, David J

    2018-01-08

    Monoclonal antibodies (mAbs) currently dominate the biopharmaceutical sector due to their potency and efficacy against a range of disease targets. These proteinaceous therapeutics are, however, susceptible to unfolding, mis-folding, and aggregation by environmental perturbations. Aggregation thus poses an enormous challenge to biopharmaceutical development, production, formulation, and storage. Hydrodynamic forces have also been linked to aggregation, but the ability of different flow fields (e.g., shear and extensional flow) to trigger aggregation has remained unclear. To address this question, we previously developed a device that allows the degree of extensional flow to be controlled. Using this device we demonstrated that mAbs are particularly sensitive to the force exerted as a result of this flow-field. Here, to investigate the utility of this device to bio-process/biopharmaceutical development, we quantify the effects of the flow field and protein concentration on the aggregation of three mAbs. We show that the response surface of mAbs is distinct from that of bovine serum albumin (BSA) and also that mAbs of similar sequence display diverse sensitivity to hydrodynamic flow. Finally, we show that flow-induced aggregation of each mAb is ameliorated by different buffers, opening up the possibility of using the device as a formulation tool. Perturbation of the native state by extensional flow may thus allow identification of aggregation-resistant mAb candidates, their bio-process parameters and formulation to be optimized earlier in the drug-discovery pipeline using sub-milligram quantities of material. © 2018 The Authors. Biotechnology and Bioengineering Published by Wiley Periodicals, Inc.

  20. Caledonian and late Caledonian Europe: a working hypothesis involving two contrasted compressional/extensional scenarios

    Directory of Open Access Journals (Sweden)

    Oyarzun, R.

    1990-08-01

    Full Text Available The tectonomagmatic and metamorphic structuration of the European Caledonian realm suggests that two mutually perpendicular compressional/extensional scenarios developed during the Ordovician-Devonian time-span. As a result of the mid Ordovician Grampian compressional scheme (Caledonian s.s., a major extensional province developed further east from the Caledonian foldbelt in continental Europe. This scenario ended by early/mid Devonian, with the complete locking of North America, Baltica and Gondwana into a Pangaea supercontinent, thus triggering a contrasted tectonic environment which might be termed La estructuración tectonomagmática y metamórfica del dominio caledónico europeo sugiere que dos escenarios, compresional y extensional, mutuamente perpendiculares, se desarrollaron durante el Ordovícico-Devónico. Como resultado del esquema compresional del Ordovícico medio (Grampian, caledónico s.s., en el O de Europa continental se desarrolló una provincia extensional localizada al E de la faja de plegamiento caledónica. Esta situación finalizó hacia el Devónico inferior/medio, cuando la convergencia de América del Norte, Báltica y Gondwana dió origen al supercontinente Pangea. Esta colisión generó un ambiente tectónico caracterizado por: 1. plegamiento y plutonismo en Europa continental occidental, y 2. extensión y volcanismo en la parte N de la faja de plegamiento caledónica (Escocia, SO de Noruega y E de Groenlandia. Este evento puede ser tentativamente denominado «Tardicaledónico». En términos globales, la evolución del dominio caledónico puede ser explicada en términos de «tectónica de inversión» (s.l., esto es, períodos de adelgazamiento cortical (extensionales seguidos por períodos de engrosamiento cortical (compresionales y viceversa

  1. 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 nucleotide...... for monolayers of single stranded (ss) DNA and after hybridization with the complementary DNA strand. Our results differ from previous data obtained with bulk samples, showing the genuine behavior of these self-assembled monolayers. The hybridization cannot be inferred from the water adsorption isotherms due...... on the interaction between water and self-assembled monolayers of nucleic acids....

  2. Dynamics of Star Polymers in Fast Extensional Flow and Stress Relaxation

    DEFF Research Database (Denmark)

    Huang, Qian; Agostini, Serena; Hengeller, Ludovica

    2016-01-01

    We confirm the observation from Ianniruberto and Marrucci [ Macromolecules 2013, 46, 267-275 ] that entangled melts of branched polystyrenes behave like linear polystyrenes in the steady state of fast extensional flow, by measuring a linear, an asymmetric star, and a symmetric star polystyrene wi...... they relax in a similar way, most likely via arm retraction, at short time, but behave differently at long time due to both the length of the arm and the branch point. The terminal relaxation is described by a Doi and Edwards based model, i.e., considering pure orientational relaxation....

  3. 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...

  4. 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...

  5. 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.

  6. 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).

  7. Late cretaceous extensional tectonics and associated igneous activity on the northern margin of the Gulf of Mexico Basin

    Science.gov (United States)

    Bowen, R. L.; Sundeen, D. A.

    1985-01-01

    Major, dominantly compressional, orogenic episodes (Taconic, Acadian, Alleghenian) affected eastern North America during the Paleozoic. During the Mesozoic, in contrast, this same region was principally affected by epeirogenic and extensional tectonism; one episode of comparatively more intense tectonic activity involving extensive faulting, uplift, sedimentation, intrusion and effusion produced the Newark Series of eposits and fault block phenomena. This event, termed the Palisades Disturbance, took place during the Late Triassic - Earliest Jurassic. The authors document a comparable extensional tectonic-igneous event occurring during the Late Cretaceous (Early Gulfian; Cenomanian-Santonian) along the southern margin of the cratonic platform from Arkansas to Georgia.

  8. 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

    The plate model of Parsons & Sclater provides a generally accepted, quantitative framework for the thermal subsidence-evolution in extensional basins. It predicts an asymptotic evolution of the geotherm towards a steady state, featuring a constant lithospheric thickness and ceased subsidence......-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...... mantle below, and cooling is thus not entirely conductive above the former base of the lithosphere. This causes significantly protracted cooling and subsidence.We show that our model features improved consistency with subsidence data from several rifted margins and intracontinental basins. Furthermore...

  9. 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.

  10. The case for pre-Middle Cretaceous extensional faulting in northern Yucca Flat, southwestern Nevada

    International Nuclear Information System (INIS)

    Cole, J.C.; Harris, A.G.; Lanphere, M.A.; Barker, C.E.; Warren, R.G.

    1993-01-01

    Extremely complex low-angle fault relationships within the Late Proterozoic to Pennsylvania sedimentary rocks near Yucca Flat, Nevada Test Site, have been previously ascribed to Mesozoic compression during the Sevier orogeny, or to middle Tertiary extension of a pre-existing thrust stack. New field evidence and detailed studies of a 3,500-foot drillhole show that this structural complexity results from post-thrust regional extension that may be much older than previously recognized. The interpreted age constraint is inferred from thermal disturbances recorded by rocks above the altered monzodiorite(?) porphyry border phase of an intrusion penetrated in the bottom of the drillhole. The pluton intrudes middle Devonian dolomite that forms the lowermost of at least seven structural sheets. Each sheet is bounded by breccia zones and consists of an identifiable slice of the local Paleozoic section without ordered sequence. The intervening structural sheets of carbonaceous siltstone appear to have been thermally disturbed because they yield essentially no volatile hydrocarbons during pyrolysis. All observed features are consistent with thermal overprinting by the 102 Ma intrusion and permit an interpretation that the complicated fault/stratigraphy relationships also predate 102 Ma. Outcrop studies of numerous low-angle faults within the Paleozoic and late Proterozoic rocks in this region indicate that many are extensional, whether they involve younger-over-older or older-over-younger age relations. The authors infer a dominantly extensional origin for the structural sheets encountered in the drillhole on the basis of similarities with the outcrop faults, but the sheets must have been derived from the upper plate of the nearby CP thrust fault

  11. 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.

  12. Estudo fitoquímico e avaliação do potencial antimicrobiano de espécies de Hortia (Rutaceae) : H. oreadica, H. brasiliana e H. superba

    OpenAIRE

    Vanessa Gisele Pasqualotto Severino

    2008-01-01

    O estudo fitoquímico de Hortia descrito neste trabalho visa contribuir com a quimiossistemática da família Rutaceae e também com a melhor classificação do gênero dentro da mesma. O estudo das espécies H. oreadica, H. brasiliana e H. superba levou ao isolamento de 15 substâncias, sendo, derivados do ácido diidrocinâmico ácido 3-fenil-[2,6-dimetoxi-(3,4-O:5,6)-2,2- dimetilpirano]propiônico (01), 3-fenil-[2-metoxi-(3,4-O:5,6)-2,2- dimetilpirano]propionato de metila (02), 3-fenil-[2,6-dimetoxi-(3...

  13. The origin of tectonic lineation in extensional basins: Combined neutron texture and magnetic analyses on "undeformed" clays

    Czech Academy of Sciences Publication Activity Database

    Cifelli, F.; Mattei, M.; Chadima, Martin; Hirt, A. M.; Hansen, A.

    2005-01-01

    Roč. 235, 1-2 (2005), s. 62-78 ISSN 0012-821X Institutional research plan: CEZ:AV0Z30130516 Keywords : anisotropy of magnetic susceptibility * extensional tectonic * neutron texture analysis Subject RIV: DB - Geology ; Mineralogy Impact factor: 3.434, year: 2005

  14. Prediction of bending set, wave efficacy, and hair damage using an extensional permanent waving treatment and the 20% index value.

    Science.gov (United States)

    Ueno, Yuzo; Namiki, Hideo

    2015-01-01

    To predict "wave efficacy" as evaluated by hairdressers, an extensional permanent waving treatment was performed on human hair fibers using various wave lotions manufactured in Japan. Glass columns devised for the purpose were equipped with a tensile tester in order to increase the measurement accuracy. Notably, the observed set agreed with the theoretical set. In addition, the data for the extensional set exhibited good correlation with the bending set and the wave efficacy assessed in a beauty parlor, and hair damage was estimated by the characteristic change in the 20% index. The following facts were experimentally determined. First, the Young's modulus of the hair fibers after extensional permanent waving treatment continually decreased with an increase in the reduction of the fibers and then abruptly decreased at 80% reduction. Second, the reduction of hair treated with the ammonium salt of thioglycolic acid followed pseudo first-order kinetics only during the initial stage of the reaction, independent of the pH level. Third, the 20% index of the individual virgin hairs remained constant in water at 30°C and also correlated with the Young's modulus of the hair after extensional permanent waving treatment.

  15. 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

    pressure assumption. Furthermore, the maximal extensibility based on the number of Kuhn steps in an entanglement has been used based on the relative Padé inverse Langevin function. The model predictions agree with the extensional measurements on all previously published poly(methyl methacrylate)s...

  16. Death Valley turtlebacks: Mesozoic contractional structures overprinted by Cenozoic extension and metamorphism beneath syn-extensional plutons

    Science.gov (United States)

    Pavlis, T. L.; Miller, M.; Serpa, L.

    2008-07-01

    The term turtleback was first coined to describe the curvilinear fault surfaces that produced a distinctive geomorphic form in the Black Mountains east of Death Valley, and although it was decades before their full significance was appreciated, they remain one of the most distinctive features of the extensional structure of the Death Valley region. Historically the interpretation of the features has varied markedly, and misconceptions about their character continue to abound, including descriptions in popular field guides for the area. It the 1990's, however, the full history of the systems began to be apparent from several key data: 1) the dating of the plutonic assemblage associated with the turtlebacks demonstrated that late Miocene, syn-extensional plutonism was fundamental to their formation; 2) the plutonic assemblage forms an intrusive sheet structurally above the turtlebacks, indicating a tie between much of the high grade metamorphism and Cenozoic plutonism; 3) a modern analog for the syn-extensional plutonism in the Black Mountains was recognized beneath Death Valley with the imaging of a mid-crustal magma body; 4) the Neogene structural history was worked out in the turtlebacks showing that folding of early-formed shear zones formed the turtleback anticlinoria but overprinting by brittle faults produced the final form as they cut obliquely across the older structure; and 5) the pre-extensional structural history was clarified, demonstrating that Mesozoic basement-involved thrust systems are present within the turtlebacks, but have been overprinted by the extensional system. An unresolved issue is the significance of Eocene U-Pb dates for pegmatites within the region, but presumably these relate somehow to the pre-extensional history. Miller and Pavlis (2005; E. Sci. Rev.) reviewed many features of the turtlebacks, and our working model for the region is that the turtlebacks originated as mid-crustal ductile-thrust systems within the Cordilleran fold

  17. 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.

  18. Microbial Communities of Terrestrial Springs in Extensional Settings of the Western U.S.A.

    Science.gov (United States)

    Takacs-Vesbach, C.; Hall, J.; Crossey, L. J.; Karlstrom, K. E.; Fischer, T.; Cron, B.

    2008-12-01

    Gas and water chemistry from hot springs, gas vents, travertine-bearing cool springs, and high-pCO2 groundwaters of the western U.S. indicate a regionally extensive flux of deeply sourced volatiles through spring vents. We use the term "continental smokers" to emphasize and test analogs to mid-ocean vent systems, and are currently concentrating on vents in the Rocky Mountain/Colorado Plateau region as part of the Colorado Rockies and Experiment and Seismic transects (CREST). Measurable mantle-derived helium components (3He/4He = 0.10 to 2.1 RA) occur in nearly all springs in Colorado and New Mexico suggesting direct fast fluid pathways from the mantle to the surface hydrologic system. Important components of the CO2 are also derived from the mantle. We surveyed the geochemistry and microbial diversity of more than forty deeply sourced terrestrial springs that ranged in temperatures from 9° to 70°C. We hypothesize that degassing in continental extensional settings supports microbial assemblages that are analogous to chemolithotrophic communities at mid-ocean ridges and continental volcanic hydrothermal systems. Geochemical characteristics of the fluids and gases structure and sustain distinctive geomicrobiological communities as indicated by the widespread presence of archaea and thermophilic organisms in cool as well as hot springs.

  19. 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.

  20. On ice rifts and the stability of non-Newtonian extensional flows on a sphere

    Science.gov (United States)

    Sayag, Roiy

    2017-11-01

    Rifts that form at the fronts of floating ice shelves that spread into the ocean can trigger major calving events in the ice. The deformation of ice can be modeled as a thin viscous film driven by buoyancy. The front of such a viscous film that propagates over a flat surface with no-slip basal conditions is known to have stable axisymmetric solutions. In contrast, when the fluid propagates under free-slip conditions at the substrate, the front can become unstable to small perturbations if the fluid is sufficiently strain-rate softening. Consequently, the front will develop tongues with a characteristic wavelength that coarsens over time, a pattern that is reminiscent of ice rifts. Here we investigate the stability of a spherical sheet of power-law fluids under free-slip basal conditions. The fluid is discharged at constant flux and axisymmetrically with respect to the pole, and propagates towards the equator. The propagating front in such a situation may become unstable due to its failure to sustain large extensional forces, resulting in the formation of rifts. This study has implications to understanding the cause of patterns that are observed on shells of floating ice in a range of planetary objects, and whether open rifts that sustain life were feasible in snowball earth. Israel Science Foundation 1368/16.

  1. 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.

  2. 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

  3. 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

  4. 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.

  5. Sensory effects of transient receptor potential channel agonists on whole mouth saliva extensional rheology.

    Science.gov (United States)

    Houghton, Jack William; Hans, Joachim; Pesaro, Manuel; Ley, Jakob Peter; Carpenter, Guy Howard; Proctor, Gordon

    2017-08-01

    The extensional rheology (ER) of saliva is a property associated with its ability to coat surfaces and is important for the maintenance of a normal mouth feeling. Transient receptor potential (TRP) channels are expressed in the oral cavity and this study investigated how the sensory effects of TRP channel agonists modify the ER of saliva. Healthy volunteers rinsed with solutions containing a TRP agonist. Unstimulated whole mouth saliva (WMS) was collected prior to rinsing and WMS was collected during the first and second minutes after the mouth rinse. The Spinnbarkeit of the collected saliva was measured using a Neva Meter. The nonivamide (TRPV1) mouth rinse increased WMS ER from 37.0 (± 6.3) mm to 49.3 (± 5.1) mm when compared with the vehicle control, which itself had no effect on WMS ER. However, this effect was short-lived and ER of WMS was not increased in the second minute after the nonivamide mouth rinse. The menthol (TRPM8) mouth rinse resulted in an increase up to 57.8 (± 7.8) mm in WMS ER from the vehicle control and returned to control levels in the second minute. The cinnamaldehyde (TRPA1) mouth rinse resulted in no change in WMS ER. It can be concluded that nonivamide and menthol mouth rinsing has a short-term effect of increasing WMS ER, an effect not observed after cinnamaldehyde rinsing. We hypothesize that the activation of some TRP channels in the oral cavity results in changes in the salivary protein composition that in turn alters WMS ER. Identifying compounds that modify the physical properties of saliva in a desirable way is important in developing treatments for conditions associated with changes in the physical properties of saliva such as xerostomia (also known as dry mouth). Furthermore, understanding the rheology of saliva contributes to the elucidation of food oral processing which is of importance to food manufacturers. © 2017 Wiley Periodicals, Inc.

  6. Extensional terrain formation on Europa and Ganymede: Implications for ocean-surface interaction

    Science.gov (United States)

    Howell, S. M.; Pappalardo, R. T.

    2017-12-01

    Europa and Ganymede, Galilean satellites of Jupiter, exhibit geologic activity in their outer H2O ice shells that might convey material from water oceans within the satellites to their surfaces. Imagery from the Voyager and Galileo spacecraft reveal surfaces rich with tectonic deformation, including dilational bands on Europa and groove lanes on Ganymede. These features are generally attributed to the extension of a brittle ice lithosphere overlaying a possibly convecting ice asthenosphere. To explore band formation and interaction with interior oceans, we employ fully visco-elasto-plastic 2-D models of faulting and convection with complex, realistic pure ice rheologies. In these models, material entering from below is tracked and considered to be "fossilized ocean," ocean material that has frozen into the ice shell and evolves through geologic time. We track the volume fraction of fossil ocean material in the ice shell as a function of depth, and the exposure of both fresh ice and fossil ocean material at the ice shell surface. We vary ice shell thickness, fault localization, melting-temperature ice viscosity, and the presence of pre-existing weaknesses. Mechanisms which act to weaken the ice shell and thin the lithosphere (e.g. vigorous convection, thinner shells, pre-existing weaknesses) tend to plastically yield to form smooth bands at high strains, and are more likely to incorporate fossil ocean material in the ice shell and expose it at the surface. In contrast, lithosphere strengthened by rapid fault annealing or increased viscosity, for example, exhibits large-scale tectonic rifting at low strains superimposed over pre-existing terrains, and inhibits the incorporation and delivery of fossil ocean material to the surface. Thus, our results identify a spectrum of extensional terrain formation mechanisms as linked to lithospheric strength, rather than any specific mechanism being unique to each type of band, and where in this spectrum ocean material

  7. Sedimentary response to tectonism in the extensional Chihuahua trough, Cretaceous of Southern North America

    Science.gov (United States)

    Budhathoki, P.; Langford, R. P.; Pavlis, T. L.

    2009-12-01

    During the Jurassic and Cretaceous, the Chihuahua Trough formed an extensional basin, extending from the Gulf of Mexico to Southern Arizona, along the Present Border of the United States and Mexico. West of the Big Bend of Texas, Jurassic and Cretaceous sediments are less than 150 m thick, and in many areas are absent. The sedimentary package thickens to over 3km within the trough. The Albian Cox Sandstone is one of the most areally extensive formations and consists of interbedded fluvial coastal and shallow marine sandstones and shales. In this study area, shales (10-70 m) are thicker more than sandstone beds (2-10 m). This unit is overlain by Finlay formation, a fine crystalline gray limestone and underlain by Bluff Mesa formation, a fossiliferous shallow marine limestone. Cross-bedded, brown, fine to medium grained sandstone, interbedded with siltstone, shale and limestone are characteristic lithology of the Cox. The Indio Mountains of Trans-Pecos Texas offer an ideal location to study how this package accommodates the deformation associated with the subsiding Chihuahua trough. A continuous outcrop extends over 30 km oblique to the basin margin and thickens from approximately 375 m on the northern side to 437 m on the southern side of the 10 km section studied so far. One important mechanism is rotation of the strata into the basin, followed by truncation along sequence boundaries. The lower two sequence in the southern Indio mountains are rotated down to the basin relative to Finlay. The lowest sequences thicken from an erosional pinch out towards the South. Shale beds thicken within the rotated strata and accommodate some of the tilting. For example, Thickness of the shale bed varies from 18 m to 70 m within a 2 km distance. However, erosional truncation of the tilted strata accounts for most of the increases in thickness within sequences. The base of the formation has been rotated about 6 degrees south relative to the top of the formation. Another observed

  8. 40Ar/39Ar constraints on the activity of the Temsamane extensional detachment (eastern Rif, Morocco)

    Science.gov (United States)

    Jabaloy Sánchez, A.; Booth-Rea, G.; Azdimousa, A.; Asebriy, L.; Vázquez-Vílchez, M.; Martínez-Martínez, J. M.; Gabites, J.

    2012-04-01

    The subducted North Maghrebian passive margin was exhumed by an upper crustal brittle-ductile extensional detachment and brittle low-angle normal faults in a continental subduction transform setting. The Temsamane detachment in the eastern Rif is defined by a ductile shear zone approximately 100 m thick with a low-angle ramp geometry that cuts down into the Temsamane fold-nappe stack. The shear zone shows southwestward kinematics and separates epizone metapelites of the Temsamane units below from the epizone to diagenetic rocks of the Tanger-Ketama-Aknoul units above. To the east, the detachment becomes brittle, branching into a listric-fan that cuts through 10-6 Ma sediments and volcanoclastics in the Tres Forcas cape. New 40Ar/39Ar radiometric ages on amphiboles and micas from the footwall of the Temsamane detachment indicate that the metamorphic peak was reached in the footwall (Temsamane units) at ca. 21 Ma, producing the amphibolite epidote facies in the Ras Afrou Unit. The cooling of the footwall rocks below the 325 °C occurred between the 16 and 13 Ma, while apatite fission track ages indicate that the cooling below the 120 °C occurred at ca. 11 Ma. The 40Ar/39Ar radiometric ages on amphiboles and micas of the metamorphic klippes over the Temsamene units (Ait-Amrâne massif) indicates that the Jurassic marbles of the Tanger-Ketama Unit reached their metamorphic peak at ca. 80 Ma, in agreement with previously published K/Ar ages in micas. The rocks of the Tanger-Ketama Unit cooled below the 120 °C between 17.0 ± 2.4 Ma and 13.9 ± 1.8 Ma. We interpret the increase of cooling rates of the footwall rocks between 15-13 Ma and 11 Ma as due to the activity of the Temsamane detachment fault. Thus, both the North Maghrebian and the South Iberian subducted passive margins were exhumed in the Betic and Rif branches of the Gibraltar arc by SW-directed brittle-ductile detachments during the Late Miocene in an oblique collisional setting.

  9. 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

  10. 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

  11. Kinematics of Post-Collisional Extensional Tectonics and Exhumation of the Menderes Massif in the Western Anatolia Extended Terrane, Turkey

    Science.gov (United States)

    Cemen, I.; Catlos, E. J.; Diniz, E.; Gogus, O.; Ozerdem, C.; Baker, C.; Kohn, M. J.; Goncuoglu, C.; Hancer, M.

    2006-12-01

    The Western Anatolia Extended Terrane in Turkey is one of the best-developed examples of post-collisional extended terranes and contains one of the largest metamorphic core complexes in the world, the Menderes massif. It has experienced a series of continental collisions from the Late Cretaceous to the Eocene as the Neotethys Ocean closed and the Izmir-Ankara-Erzincan suture zone was formed. Based our field work and monazite ages, we suggest that the north-directed postcollisional Cenozoic extension in the region is the product of three consecutive, uninterrupted stages, triggered by three different mechanisms. The first stage was initiated about 30 Ma ago, in the Oligocene by the Orogenic Collapse the thermally weakened continental crust along the north-dipping Southwest Anatolian shear zone. The shear zone was formed as an extensional simple-shear zone with listric geometry at depth and exhibits predominantly normal- slip along its southwestern end. But, it becomes a high-angle oblique-slip shear zone along its northeastern termination. Evidence for the presence of the shear zone includes (1) the dominant top to the north-northeast shear sense indicators throughout the Menderes massif, such as stretching lineations trending N10E to N30E; and (2) a series of Oligocene extensional basins located adjacent to the shear zone that contain only carbonate and ophiolitic rock fragments, but no high grade metamorphic rock fragments. During this stage, erosion and extensional unroofing brought high-grade metamorphic rocks of the central Menderes massif to the surface by the early Miocene. The second stage of the extension was triggered by subduction roll-back and associated back-arc extension in the early Miocene and produced the north-dipping Alasehir and the south-dipping Buyuk Menderes detachments of the central Menderes massif and the north-dipping Simav detachment of the northern Menderes massif. The detachments control the Miocene sedimentation in the Alasehir, Buyuk

  12. Death Valley turtlebacks: Mesozoic contractional structures overprinted by Cenozoic extension and metamorphism beneath syn-extensional plutons

    International Nuclear Information System (INIS)

    Pavlis, T L; Serpa, L; Miller, M

    2008-01-01

    The term turtleback was first coined to describe the curvilinear fault surfaces that produced a distinctive geomorphic form in the Black Mountains east of Death Valley, and although it was decades before their full significance was appreciated, they remain one of the most distinctive features of the extensional structure of the Death Valley region. Historically the interpretation of the features has varied markedly, and misconceptions about their character continue to abound, including descriptions in popular field guides for the area. It the 1990's, however, the full history of the systems began to be apparent from several key data: 1) the dating of the plutonic assemblage associated with the turtlebacks demonstrated that late Miocene, syn-extensional plutonism was fundamental to their formation; 2) the plutonic assemblage forms an intrusive sheet structurally above the turtlebacks, indicating a tie between much of the high grade metamorphism and Cenozoic plutonism; 3) a modern analog for the syn-extensional plutonism in the Black Mountains was recognized beneath Death Valley with the imaging of a mid-crustal magma body; 4) the Neogene structural history was worked out in the turtlebacks showing that folding of early-formed shear zones formed the turtleback anticlinoria but overprinting by brittle faults produced the final form as they cut obliquely across the older structure; and 5) the pre-extensional structural history was clarified, demonstrating that Mesozoic basement-involved thrust systems are present within the turtlebacks, but have been overprinted by the extensional system. An unresolved issue is the significance of Eocene U-Pb dates for pegmatites within the region, but presumably these relate somehow to the pre-extensional history. Miller and Pavlis (2005; E. Sci. Rev.) reviewed many features of the turtlebacks, and our working model for the region is that the turtlebacks originated as mid-crustal ductile-thrust systems within the Cordilleran fold

  13. 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

  14. Extensional Strain Hardening Induced by π -π Interactions in Barely Entangled Polymer Chains: The Curious Case of Poly(4-vinylbiphenyl)

    Science.gov (United States)

    López-Barrón, Carlos R.; Zhou, Huaxing

    2017-12-01

    Aromatic π -π interactions between phenyl groups of adjacent chains in poly(4-vinylbiphenyl) (PVBP) have profound effects on the dynamics of this polymer. We report two unexpected nonlinear viscoelastic responses of PVBP when subjected to uniaxial flow. One is the unprecedented observation of extensional strain hardening (SH) in a barely entangled polymer melt. An even more intriguing finding is that SH of lightly (or even barely) entangled melts occurs at strain rates one order of magnitude below the coil-stretch transition predicted by Rouse theory (ɛ˙ H=0.5 /τR ).We postulate that this behavior is due to a molecular rearrangement mechanism (supported by x-ray diffraction measurements) that involves flow-induced π -π stacking of the phenyl groups, which results in an enhancement of the friction coefficient between polymer chains.

  15. The effect of shear and extensional viscosities on atomization of Newtonian and non-Newtonian fluids in ultrasonic inhaler.

    Science.gov (United States)

    Broniarz-Press, L; Sosnowski, T R; Matuszak, M; Ochowiak, M; Jabłczyńska, K

    2015-05-15

    The paper contains results of the experimental study on atomization process of aqueous solutions of glycerol and aqueous solutions of glycerol-polyacrylamide (Rokrysol WF1) in an ultrasonic inhaler. In experiments the different concentration aqueous solutions of glycerol and glycerol-polyacrylamide have been tested. The results have been obtained by the use of laser diffraction technique. The differences between characteristics of ultrasonic atomization for test liquids have been observed. The analysis of drop size histograms shows that the different sizes of drops have been formed during atomization process. The present study confirmed the previous reports which suggested that the drops size changes with the increase in viscosity of solution changes in spray characteristics were also observed. It has been shown that the shear and extensional viscosities affect the process of atomization. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. 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.

  17. 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.

  18. 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.

  19. Extensional origin of ductile fabrics in the Schist Belt, Central Brooks Range, Alaska—II. Microstructural and petrofabric evidence

    Science.gov (United States)

    Law, Richard D.; Miller, Elizabeth L.; Little, Timothy A.; Lee, Jeffrey

    1994-07-01

    A regional system of S-dipping faults is exposed in the Florence and Fall Creeks area of the south-central Brooks Range. This fault system has previously been mapped as the ·root zone' of a N-vergent fold-and-thrust belt of Jurassic-Cretaceous age, although individual faults juxtapose lower grade on higher grade metamorphic rocks suggesting apparent extensional geometries. The structurally highest of these faults places rocks of the oceanic Paleozoic-Mesozoic Angayucham terrane, together with unconformably overlying Cretaceous clastic rocks, on Devonian metagreywacke and phyllite. This metagreywacke-phyllite (MP) unit in turn structurally overlies Devonian (?) and older basement rocks of the Brooks Range Schist Belt along a S-dipping structural contact previously mapped as the Florence Creek fault. The Schist Belt and MP units are both characterized by a regionally developed, S-dipping greenschist facies foliation that displays a pronounced N-S-trending, down-dip elongation lineation which earlier workers regarded as being associated with N-vergent thrusting. While only one foliation ( Sd) is recognized in the MP unit, in the underlying Schist Belt this foliation ( S2) overprints an earlier blueschist facies mineral assemblage and associated foliation ( S1). Mylonites with strong asymmetric crystal fabrics are well developed in quartz stringers in the MP unit and in Schist Belt rocks located at less than 250 m beneath the Florence Creek fault. These asymmetric single- and cross-girdle c-axis fabrics indicate a top down-to-the-south shear sense. This shear sense is confirmed in XZ sections by the presence of elongate, dynamically recrystallized quartz grains oblique to the Sd - S2 mylonitic foliation. Quartzose and quartzo-feldspathic lithologies become coarser grained in the deeper levels of the Schist Belt, and a greater proportion of the quartz grains are equant in outline suggesting the increasing importance of temperature-sensitive recovery processes. These

  20. 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

  1. 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.

  2. Evaluation of a silicon 5 MHz p–n diode actuator with a laterally vibrating extensional mode

    Science.gov (United States)

    Miyazaki, Fumito; Baba, Kazuki; Tanigawa, Hiroshi; Furutsuka, Takashi; Suzuki, Kenichiro

    2018-05-01

    In this paper, we describe p–n diode actuators that are laterally driven by the force induced in a depletion layer. The previously reported p–n diode actuators have been vertically driven. Because the resonant frequency depends on the thickness of the vibrating plate, the integration of resonators with different frequencies on a chip has been difficult. The resonators in this work are driven laterally by using length-extensional vibration. We have developed a compact model based on an analytical expression, in which p–n diode actuators are driven by the forces induced by the spread of the depletion layer. The deflection generated by the p–n diode actuators was proportional to the ratio of the depletion layer width to the resonator thickness as well as the position of the p–n junction. Good agreement of experimental results with the theory was confirmed by comparing the measured values for silicon p–n diode rectangular-plate actuators fabricated using a silicon-on-insulator (SOI) substrate. The displacement amplitude of the actuators was proportional to the DC bias, while the resonant frequency was independent of the DC bias. The latter characteristic is very different from that of widely used electrostatic actuators. Although the amplitude of the actuator measured in this work was very small, it is expected that the amplitude will increase greatly by increasing the doping of the p–n diode actuators.

  3. 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.

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

    International Nuclear Information System (INIS)

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

    2017-01-01

    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.

  5. Extensional flow of low-viscosity fluids in capillary bridges formed by pulsed surface acoustic wave jetting

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharjee, P K; McDonnell, A G; Prabhakar, R; Yeo, L Y; Friend, J, E-mail: james.friend@monash.edu.au [MicroNanophysics Research Laboratory, Department of Mechanical and Aerospace Engineering, Monash University, Melbourne, VIC 3800 (Australia); Melbourne Centre for Nanofabrication, Melbourne, VIC 3800 (Australia)

    2011-02-15

    Forming capillary bridges of low-viscosity ({approx}<10 mPa s) fluids is difficult, making the study of their capillary-thinning behavior and the measurement of the fluid's extensional viscosity difficult as well. Current techniques require some time to form a liquid bridge from the stretching of a droplet. Rapidly stretching a liquid bridge using these methods can cause its breakup if the viscosity is too low. Stretching more slowly allows the bridge to thin and break up before a suitable bridge geometry can be established to provide reliable and accurate rheological data. Using a pulsed surface acoustic wave to eject a jet from a sessile droplet, a capillary bridge may be formed in about 7.5 ms, about seven times quicker than current methods. With this approach, capillary bridges may be formed from Newtonian and non-Newtonian fluids having much lower viscosities-water, 0.04% by weight solution of high-molecular-weight (7 MDa) polystyrene in dioctyl phthalate and 0.25% fibrinogen solution in demineralized water, for example. Details of the relatively simple system used to achieve these results are provided, as are experimental results indicating deviations from a Newtonian response by the low-viscosity non-Newtonian fluids used in our study.

  6. 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.

  7. Release fault: A variety of cross fault in linked extensional fault systems, in the Sergipe-Alagoas Basin, NE Brazil

    Science.gov (United States)

    Destro, Nivaldo

    1995-05-01

    Two types of cross faults are herein recognized: transfer faults and the newly termed release faults. Transfer faults form where cross faults connect distinct normal faults and horizontal displacements predominate over vertical ones. In contrast, release faults form where cross faults associated with individual normal faults die out within the hangingwall before connecting to other normal faults, and have predominantly vertical displacements. Release faults are geometrically required to accommodate variable displacements along the strike of a normal fault. Thus, they form to release the bending stresses in the hangingwall, and do not cut normal fault planes nor detachment surfaces at depth. Release faults have maximum throws adjacent to normal faults, and may be nearly perpendicular or obliquely oriented to the strike of the latter. Such geometry appears not to depend upon pre-existing weaknesses, but such variable orientation to normal faults is an inherent property of release faults. Release faults commonly appear as simple normal faults in seismic sections, without implying extension along the strike of rift and basins. Three-dimensional strain deformation occurs in the hangingwall only between the terminations of an individual normal fault, but regionally, release faulting is associated with plane strain deformation in linked extensional fault systems.

  8. 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.

  9. From colloidal spheres to nanofibrils: extensional flow properties of mineral pigment and mixtures with micro and nanofibrils under progressive double layer suppression.

    Science.gov (United States)

    Dimic-Misic, Katarina; Hummel, Michael; Paltakari, Jouni; Sixta, Herbert; Maloney, Thad; Gane, Patrick

    2015-05-15

    Suspensions of mineral pigment and cellulose fibrillar derivatives are materials regularly found in the forest products industries, particularly in paper and board production. Many manufacturing processes, including forming and coating employ flow geometries incorporating extensional flow. Traditionally, colloidal mineral pigment suspensions have been considered to show little to no non-linear behaviour in extensional viscosity. Additionally, recently, nanofibrillar materials, such as microfibrillar (MFC) and nanofibrillar cellulose (NFC), collectively termed MNFC, have been confirmed by their failure to follow the Cox-Merz rule to behave more as particulate material rather than showing polymeric rheological properties when dispersed in water. Such suspensions and their mixtures are currently intensively investigated to enable them to generate likely enhanced composite material properties. The processes frequently involve exposure to increasing levels of ionic strength, coming either from the weak solubility of pigments, such as calcium carbonate, or retained salts arising from the feed fibre source processing. By taking the simple case of polyacrylate stabilised calcium carbonate suspension and comparing the extensional viscosity as a function of post extension capillary-induced Hencky strain on a CaBER extensional rheometer over a range of increasing salt concentration, it has been shown that the regime of constriction changes as the classic DLVO double layer is progressively suppressed. This change is seen to lead to a characteristic double (bimodal) measured viscosity response for flocculated systems. With this novel characteristic established, more complex mixed suspensions of calcium carbonate, clay and MNFC have been studied, and the effects of fibrils versus flocculation identified and where possible separated. This technique is suggested to enable a better understanding of the origin of viscoelasticity in these important emerging water-based suspensions

  10. 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

  11. Metamorphic and Ar/Ar geochronology constraints on the Alakeci shear zone: Implications for the extensional exhumation history of the northern Kazdag Massif, NW Turkey

    International Nuclear Information System (INIS)

    Bonev, N; Beccaletto, L; Robyr, M; Monie, P

    2008-01-01

    The Kazdag Massif exposes a metamorphic dome in the Biga Peninsula of northwest Turkey. An extensional origin has been proposed for the dome, limited on both flanks by detachments and/or shear zones. The northern flank is bounded by the extensional Alakeci Shear Zone (ASZ), whose P-T-t path is still poorly known. We therefore focus on its metamorphic conditions and related temporal history to precise its tectono-metamorphic evolution. The local tectonostratigraphy in structurally ascending order comprises: (i) the high-grade metamorphic core rocks of the Kazdag Massif (gneisses and micaschists intercalated with amphibolites and marbles); (ii) the two kilometer-thick ASZ; (iii) the overlaying unmetamorphosed pre-Cenomanian accretionary Cetmi melange; and (iv) Neogene sedimentary and volcanic cover rocks. ASZ mylonites were derived from both the core rocks and the melange lithologies. From the north to the south the mylonitic fabrics in the ASZ depict a top-to-the N-NNE shearing, parallel to the NNE-plunging stretching lineation and NNW-dipping mylonitic foliation. This geometry implies normal sense movement i.e. north-side down-dip extensional displacement along this flank of the Kazdag Massif. The northward transition from ductile to brittle-ductile regime through the ASZ shows that the deformation occurred at decreasing temperatures and degree of metamorphism. The paragenesis in equilibrium within the mylonitic gneisses and schists contains Qtz + Fs + Ms + Bt + Grt ± St ± Sill, with late retrogressive chlorite after biotite and garnet. Four samples of ASZ rocks yielded pressures between 6.9-5.7 kbar and temperatures between 706-587 deg. C. Three samples from the mylonitic rocks supplied in situ isochron 36 Ar/ 40 Ar mica ages between 31.2-24.2 Ma, which we interpret to date the cooling of the mylonites following the P-T decrease across the ASZ. The metamorphic and structural results support the extensional character of the ASZ, and sketch transition from

  12. Assessing interaction of active extensional faults from structural and paleoseismological analysis: The Teruel and Concud faults (eastern Spain)

    Science.gov (United States)

    Simón, José L.; Arlegui, Luis E.; Ezquerro, Lope; Lafuente, Paloma; Liesa, Carlos L.; Luzón, Aránzazu

    2017-10-01

    The relationship of independence, interaction or linkage between two neighbouring intraplate active extensional faults, the Teruel and Concud faults, are investigated from structural and paleoseismological data, and the results are discussed to improve seismic hazard assessment for the region. This paper provides the structural and paleoseismological characterization of the almost unknown Teruel Fault from detailed mapping and trench analysis, and discusses its kinematic and dynamic relationships with the Concud Fault. Four individual events occurred between 76.0 ka and 9.2 ka BP have been recorded at two branches of the Teruel Fault. Unfortunately, these only represent a small fraction of its overall activity during such time lapse, and their time constraints do not allow correlating them with those at the Concud Fault. The Teruel and Concud faults are independent structures from the geometric and kinematic point of view, as evinced by their distinct (i) transport directions (N275°E and N220°E, respectively), and (ii) average coseismic displacements (0.5 m and 1.9 m, respectively). These displacements are consistent with their respective lengths (9.0 km and 14.2 km) and significantly smaller than those expected for a hypothetically joint Concud-Teruel, 23 km-long fault. However, their displacement gradients close to the relay zone indicate that both faults undergo dynamic interaction, thus suggesting a transient stage from independence to linkage. We hypothesize that slip on both structures occurred, at the scale of the seismic cycle, in a broadly alternating manner, which induced strain partitioning between them and allowed accommodating bulk biaxial extension in the region. Such deformation pattern would have increased the earthquake frequency with respect to the scenario of a hypothetically linked Concud-Teruel Fault, but diminished the potential seismic magnitude.

  13. Ciclo gametogênico e comportamento reprodutivo de Iphigenia brasiliana (Mollusca, Bivalvia, Donacidae no estuário do rio Subaé, Baía de Todos os Santos, Bahia, Brasil

    Directory of Open Access Journals (Sweden)

    Patrícia P. Silva

    Full Text Available Este estudo teve como objetivos descrever o ciclo gametogênico e o comportamento reprodutivo da população de Iphigenia brasiliana (Lamarck,1818 no estuário do rio Subaé, Baía de Todos os Santos, Bahia. Os bivalves foram coletados de novembro de 2001 a novembro de 2002. Um total de 244 espécimes foi medido (eixo anteroposterior, eviscerado, fixado, desidratado e incluído em parafina. O estudo histológico das gônadas foi realizado através de cortes seriados do tecido gonadal, de 5 mm de espessura, e corados pela HE. O tamanho médio mínimo da primeira maturação sexual (Lpm foi estimado a partir da distribuição das frequências relativas de jovens e adultos, por classe de comprimento dos indivíduos. As frequências relativas dos sexos em cada estádio de desenvolvimento foram consideradas conjuntamente para a análise do comportamento reprodutivo da população, e, em separado, para avaliar a sincronia do ciclo sexual entre machos e fêmeas. Foi observada uma variação de tamanhos entre 9,1 e 66,6 mm, com comprimento médio de 50,2 mm. O estudo não demonstrou diferença significativa entre os tamanhos de machos e fêmeas. Não foi possível observar a diferenciação de sexos em 2,1% dos indivíduos analisados. 51,6% dos indivíduos foram identificados como machos (M e 46,3% como fêmeas (F, não sendo constatadas diferenças significativas entre o número médio de machos e fêmeas, resultando numa proporção de M:F de 1,1:1. O Lpm foi estimado em 11,4 mm, mas apenas ao alcançarem comprimento médio de 34,4 mm, todos os indivíduos foram considerados adultos. Foram caracterizados quatro estádios de evolução do desenvolvimento gonadal em fêmeas e machos. A análise dos diferentes estádios permitiu a observação dos fenômenos de atresia e inversão sexual em fêmeas. O ciclo reprodutivo apresentou eliminação contínua de gametas, com maiores intensidades reprodutivas nos meses de novembro de 2001 a abril de 2002 e, tamb

  14. 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

  15. 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

  16. Inherited discontinuities and fault kinematics of a multiphase, non-colinear extensional setting: Subsurface observations from the South Flank of the Golfo San Jorge basin, Patagonia

    Science.gov (United States)

    Paredes, José Matildo; Aguiar, Mariana; Ansa, Andrés; Giordano, Sergio; Ledesma, Mario; Tejada, Silvia

    2018-01-01

    We use three-dimensional (3D) seismic reflection data to analyze the structural style, fault kinematics and growth fault mechanisms of non-colinear normal fault systems in the South Flank of the Golfo San Jorge basin, central Patagonia. Pre-existing structural fabrics in the basement of the South Flank show NW-SE and NE-SW oriented faults. They control the location and geometry of wedge-shaped half grabens from the "main synrift phase" infilled with Middle Jurassic volcanic-volcaniclastic rocks and lacustrine units of Late Jurassic to Early Cretaceous age. The NE-striking, basement-involved normal faults resulted in the rapid establishment of fault lenght, followed by gradual increasing in displacement, and minor reactivation during subsequent extensional phases; NW-striking normal faults are characterized by fault segments that propagated laterally during the "main rifting phase", being subsequently reactivated during succesive extensional phases. The Aptian-Campanian Chubut Group is a continental succession up to 4 km thick associated to the "second rifting stage", characterized by propagation and linkage of W-E to WNW-ESE fault segments that increase their lenght and displacement in several extensional phases, recognized by detailed measurement of current throw distribution of selected seismic horizons along fault surfaces. Strain is distributed in an array of sub-parallel normal faults oriented normal to the extension direction. A Late Cretaceous-Paleogene (pre-late Eocene) extensional event is characterized by high-angle, NNW-SSE to NNE-SSW grabens coeval with intraplate alkali basaltic volcanism, evidencing clockwise rotation of the stress field following a ∼W-E extension direction. We demonstrate differences in growth fault mechanisms of non-colinear fault populations, and highlight the importance of follow a systematic approach to the analysis of fault geometry and throw distribution in a fault network, in order to understand temporal-spatial variations

  17. Tectono-sedimentary evolution of an extensional basin revealed by a combined photo-geological and field-mapping approach. The Montefalco Basin (Northern Apennines, Italy)

    Science.gov (United States)

    Bucci, Francesco; Mirabella, Francesco; Santangelo, Michele; Cardinali, Mauro; Guzzetti, Fausto

    2016-04-01

    Active extensional basins are important since their sedimentary infills and bounding tectonic structures provide: i) sinks with preservation potential for sedimentary and fossil records of past changes in climate and sediment/water supply, ii) information on the growth, activity, decay and death of normal faults, iii) vast economic reserves of hydrocarbons, water and minerals. Unfortunately, quaternary extensional basins, especially if located in humid and temperate climate environments, are often characterized by extensively cultivated areas, homogeneous terrains and quite flat morphologies. Furthermore, they commonly host human settlements, together with roads, economic and industrial infrastructures, with a consequent limited availability of good outcrops. Such a limitation can (often severely) hamper an adequate mapping of the sedimentary infill. Therefore alternative methodological approaches (such as aerial photographs interpretation, API) are needed to integrate heterogeneous and incomplete datasets. This contribution presents an updated photo-geological map of a Quaternary extensional basin in Central Italy, the Montefalco Basin. This basin developed in a continental environment characterized by clayey-sandy lacustrine and fluvial sequences (late Pliocene - early Pleistocene) underlying more recent coarse grained deposits related to alluvial fan environment (early-to-late Pleistocene) and younger palustrine deposits (late Pleistocene). Since the late Pleistocene, regional uplift and local tectonics led to the end of deposition in the Montefalco basin, which experienced a diffuse incision and the modification of the drainage network, in response to the W-to-E migration of active faulting and tectonic subsidence. The new photo-geological map represents an important improvement compared to the existing data, since it provides unprecedented and spatially distributed information on the geometry of the continental deposits and on the tectonic structures affecting

  18. Extensional collapse in the Neoproterozoic Araçuaí orogen, eastern Brazil: a setting for reactivation of asymmetric crenulation cleavage

    Science.gov (United States)

    Marshak, Stephen; Alkmim, Fernando F.; Whittington, Alan; Pedrosa-Soares, Antônio Carlos

    2006-01-01

    The Araçuaí orogen of eastern Brazil is one of many Brasiliano/Pan African orogens formed during the Neoproterozoic assembly of Gondwana. Its western edge, bordering the São Francisco craton, is the Serra do Espinhaço fold-thrust belt, in which top-up-to-the-west (reverse-sense) faults, west-verging folds (F 1), and east-dipping spaced to phyllitic cleavage (S 1) developed. We have found that the kinematics of deformation changes markedly at the hinterland margin of this fold-thrust belt. Here, beneath a plateau known as the Chapada Acauã, metadiamictite and fine-grained pelitic schist comprise an east-dipping belt that contains an assemblage of structures indicative of top-down-to-the-east (normal-sense) shear. This assemblage includes a cascade of F 2 folds that refold F 1 folds and verge down the dip of the belt's enveloping surfaces, vertical tension gashes, and top-down-to-the-east rotated clasts. Based on the presence of these structures, we propose that the plateau exposes a regional-scale normal-sense shear zone, here called the Chapada Acauã shear zone (CASZ). Because F 2 folds refold F 1 folds, normal-sense shear in the CASZ occurred subsequent to initial west-verging thrusting. Considering this timing of motion in the CASZ, we suggest that the zone accommodated displacement of the internal zone of the Araçuaí orogen down, relative to its foreland fold-thrust belt, and thus played a role in extensional collapse of the orogen. The CASZ trends parallel to preserved thrusts to the west, and thus may represent an inverted thrust fault. Notably, throughout the CASZ, S 1 schistosity has been overprinted by a pervasive, west-dipping asymmetric crenulation cleavage (S 2). The sigmoid shape of S 1 surfaces in S 2 microlithons require that slip on each S 2 surface was top-down-to-the-west. S 2 cleavage is axial-planar to the down-dip verging F 2 folds. Based on its geometry, we suggest that S 2 cleavage initiated either as an antithetic extensional

  19. 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.

  20. 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

  1. Seismological observations at the Northern Andean region of Colombia: Evidence for a shallowly subducting Caribbean Slab and an extensional regime in the upper plate

    Science.gov (United States)

    Monsalve, G.; Cardona, A.; Yarce, J.; Alvira, D.; Poveda, E.

    2013-05-01

    A number of seismological observations, among which we can mention teleseismic travel time residuals, P to S receiver functions and Pn velocity quantification, suggest a clear distinction between the seismic structure of the crust and uppermost mantle between the plains on the Caribbean coast of Colombia and the mountains at the Northern Andean region. Absolute and relative travel time residuals indicate the presence of a seismically fast material in the upper mantle beneath northern Colombia; preliminary results of Pn studies show a region of relatively slow Pn velocities (between 7.8 and 7.9 km/s) underneath the Caribbean coast, contrasting with values greater than 8 km/s beneath the Central and Western cordilleras of Colombia, and the Pacific coast; receiver functions suggest a significantly thinner crust beneath the Caribbean coast, with a crustal thickness between 25 and 30 km, than beneath the Northern Andean zone at the cordilleras of Colombia, where it exceeds 40 km and reaches about 57 km at the location of Bogota. Besides the obviuos discrepancies that appear in response to different topography, we think that the seismological observations are a consequence of the presence of two very distinct slab segments beneath Colombia and contrasting behaviors of the upper plate, which correspond to Caribbean and Nazca subductions. Our seismic observations can be explained by a shallowly subducting Caribbean Plate, in the absence of an asthenospheric wedge, that steepens at about the location of the Bucaramanga nest, and a thinned continental crust that reflects an extensional component linked to oblique convergence of the Caribbean, which contrasts with the crustal thickening in the Andean Cordillera linked to crustal shortening and Nazca plate subuction. These new data are consistent with the idea of of a relatively warm Nazca slab of Neogene age which seems to have a relatively frontal convergence, and a colder, more buoyant Caribbean slab which represents an

  2. S-type granite generation and emplacement during a regional switch from extensional to contractional deformation (Central Iberian Zone, Iberian autochthonous domain, Variscan Orogeny)

    Science.gov (United States)

    Pereira, M. F.; Díez Fernández, R.; Gama, C.; Hofmann, M.; Gärtner, A.; Linnemann, U.

    2018-01-01

    Zircon grains extracted from S-type granites of the Mêda-Escalhão-Penedono Massif (Central Iberian Zone, Variscan Orogen) constrain the timing of emplacement and provide information about potential magma sources. Simple and composite zircon grains from three samples of S-type granite were analyzed by LA-ICP-MS. New U-Pb data indicate that granites crystallized in the Bashkirian (318.7 ± 4.8 Ma) overlapping the proposed age range of ca. 321-317 Ma of the nearby S-type granitic rocks of the Carrazeda de Anciães, Lamego and Ucanha-Vilar massifs. The timing of emplacement of such S-type granites seems to coincide with the waning stages of activity of a D2 extensional shear zone (i.e. Pinhel shear zone) developed in metamorphic conditions that reached partial melting and anatexis (ca. 321-317 Ma). Dykes of two-mica granites (resembling diatexite migmatite) are concordant and discordant to the compositional layering and S2 (main) foliation of the high-grade metamorphic rocks of the Pinhel shear zone. Much of the planar fabric in these dykes was formed during magmatic crystallization and subsequent solid-state deformation. Field relationships suggest contemporaneity between the ca. 319-317 Ma old magmatism of the study area and the switch from late D2 extensional deformation to early D3 contractional deformation. Inherited zircon cores are well preserved in these late D2-early D3 S-type granite plutons. U-Pb ages of inherited zircon cores range from ca. 2576 to ca. 421 Ma. The spectra of inherited cores overlap closely the range of detrital and magmatic zircon grains displayed by the Ediacaran to Silurian metasedimentary and metaigneous rocks of the Iberian autochthonous and parautochthonous domains. This is evidence of a genetic relationship between S-type granites and the host metamorphic rocks. There is no substantial evidence for the addition of mantle-derived material in the genesis of these late D2-early D3 S-type granitic rocks. The ɛNd arrays of heterogeneous

  3. Geochemical Relationships between Middle- to Upper-Crustal Exposures of the Alisitos Oceanic Arc (Baja California, Mexico): An Outstanding Field Analog to Active Extensional Oceanic Arcs

    Science.gov (United States)

    Morris, R.; DeBari, S. M.; Busby, C.; Medynski, S.

    2016-12-01

    The southern volcano-bounded basin of the Rosario segment of the Cretaceous Alisitos oceanic arc provides outstanding 3-D exposures of an extensional arc, where crustal generation processes are recorded in the upper-crustal volcanic units and underlying middle-crustal plutonic rocks. Geochemical linkages between exposed crustal levels provide an analog for extensional arc systems such as the Izu-Bonin-Mariana (IBM) Arc. Upper-crustal units comprise a 3-5 km thick volcanic-volcaniclastic stratigraphy with hypabyssal intrusions. Deep-seated plutonic rocks intrude these units over a transition of <500m, where rafted volcanic blocks and evidence of magma mingling are exposed. Thermobarometry suggests <6 km emplacement depths. Compositional ranges (basalt to rhyolite) and mineral assemblages are similar in both middle-crustal and upper-crustal units, with striking compositional overlap. The most mafic compositions occur in upper-crustal hypabyssal units, and as amphibole cumulates in the plutonic rocks ( 51% SiO2). The most felsic compositions occur in welded ignimbrites and a tonalite pluton ( 71% SiO2). All units are low K with flat REE patterns, and show LILE enrichment and HFSE depletion. Trace element ratios show limited variation throughout the crustal section. Zr/Y and Nb/Y ratios are similar to the Izu active ( 3 Ma to present) zone of extension immediately behind the arc front, suggesting comparable mantle melt % during extension. Th/Zr ratios are more enriched in Alisitos compared to Izu, suggesting greater subducted sediment input. The Alisitos crustal section shows a limited range in ɛNd (5.7-7.1), but a wider range in 87Sr/86Sr (0.7035-0.7055) and 206Pb/204Pb (18.12-19.12); the latter is likely alteration effects. Arc magmas were derived from a subduction-modified MORB mantle source, less depleted than Izu arc front and less enriched than the rear arc, but is a good match with the zone of extension that lies between. Differentiation occurred in a closed

  4. 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.

  5. Infiltration of meteoric fluids in an extensional detachment shear zone (Kettle dome, WA, USA): How quartz dynamic recrystallization relates to fluid-rock interaction

    Science.gov (United States)

    Quilichini, Antoine; Siebenaller, Luc; Nachlas, William O.; Teyssier, Christian; Vennemann, Torsten W.; Heizler, Matthew T.; Mulch, Andreas

    2015-02-01

    We document the interplay between meteoric fluid flow and deformation processes in quartzite-dominated lithologies within a ductile shear zone in the footwall of a Cordilleran extensional fault (Kettle detachment system, Washington, USA). Across 150 m of shear zone section, hydrogen isotope ratios (δD) from synkinematic muscovite fish are constant (δD ˜ -130‰) and consistent with a meteoric fluid source. Quartz-muscovite oxygen isotope thermometry indicates equilibrium fractionation temperatures of ˜365 ± 30 °C in the lower part of the section, where grain-scale quartz deformation was dominated by grain boundary migration recrystallization. In the upper part of the section, muscovite shows increasing intragrain compositional zoning, and quartz microstructures reflect bulging recrystallization, solution-precipitation, and microcracking that developed during progressive cooling and exhumation. The preserved microstructural characteristics and hydrogen isotope fingerprints of meteoric fluids developed over a short time interval as indicated by consistent mica 40Ar/39Ar ages ranging between 51 and 50 Ma over the entire section. Pervasive fluid flow became increasingly channelized during detachment activity, leading to microstructural heterogeneity and large shifts in quartz δ18O values on a meter scale. Ductile deformation ended when brittle motion on the detachment fault rapidly exhumed the mylonitic footwall.

  6. Extensional Volcanism of the Taos Plateau Volcanic Field, Northern Rio Grande Rift, USA: New Insights from Geologic Mapping, 40Ar/39Ar Geochronology, Geochemistry and Geophysical Modeling

    Science.gov (United States)

    Thompson, R. A.; Turner, K. J.; Cosca, M. A.; Drenth, B.; Grauch, V. J. S.

    2016-12-01

    The Pliocene Taos Plateau Volcanic Field (TPVF) is the largest volcanic field of the Rio Grande rift. Deposits of the TPVF are distributed across 4500 km2 in the southern part of the 11,500 km2 San Luis Valley in southern Colorado and northern New Mexico constituting a major component of the structural San Luis Basin (SLB) fill. Exposed deposit thicknesses range from a few meters near the distal termini of basaltic lava flows to 240 m in the Rio Grande gorge near Taos, NM. New geologic mapping and 100 high-resolution 40Ar/39Ar age determinations help identify a complex distribution of >50 exposed eruptive centers ranging in composition from basalt to rhyolite. Total eruptive volume, estimated from geologic map relations, geophysical modeling of basin geometry and subsurface distribution of basaltic deposits, are approximately 300 km3; comprising 66% Servilleta Basalt (tholeiite), 3% mildly alkaline trachybasalt & trachyandesite, 12% olivine andesite, 17% dacite, and Guadalupe Mountain/Cerro Negro, 3.9 Ma Ute Mountain, and 3 Ma San Antonio Mountain) reach elevations of 3300 m, 770 m above the valley floor each spatially and temporally associated with fault-bounded sub-basins superposed on the broader structural SLB. Locally, coeval Pliocene fault-slip rates are 2.5 times the long-term rates determined for the SLB confirming the temporal association of local intrabasin extensional faulting and eruptive centers.

  7. 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.

  8. Long-term fluid circulation in extensional faults in the central Catalan Coastal Ranges: P-T constraints from neoformed chlorite and K-white mica

    Science.gov (United States)

    Cantarero, Irene; Lanari, Pierre; Vidal, Olivier; Alías, Gemma; Travé, Anna; Baqués, Vinyet

    2014-01-01

    The neoformation of chlorite and K-white mica in fault rocks from two main faults of the central Catalan Coastal Ranges, the Vallès and the Hospital faults, has allowed us to constrain the P-T conditions during fault evolution using thermodynamic modeling. Crystallization of M1 and M2 muscovite and microcline occured as result of deuteric alteration during the exhumation of the pluton (290 °C > T > 370 °C) in the Permian. After that, three tectonic events have been distinguished. The first tectonic event, attributed to the Mesozoic rifting, is characterized by precipitation of M3 and M4 phengite together with chlorite and calcite C1 at temperatures between 190 and 310 °C. The second tectonic event attributed to the Paleogene compression has only been identified in the Hospital fault with precipitation of low-temperature calcite C2. The shortcut produced during inversion of the Vallès fault was probably the responsible for the lack of neoformed minerals within this fault. Finally, the third tectonic event, which is related to the Neogene extension, is characterized in the Vallès fault by a new generation of chlorite, associated with calcite C4 and laumontite, formed at temperatures between 125 and 190 °C in the absence of K-white mica. Differently, the Hospital fault is characterized by the precipitation of calcite C3 during the syn-rift stage at temperatures around 150 °C and by low-temperature fluids precipitating calcites C5, C6 and PC1 during the post-rift stage. During the two extensional events (Mesozoic and Neogene), faults acted as conduits for hot fluids producing anomalous high geothermal gradients (50 °C/km minimum).

  9. Extensional Tectonics and Sedimentary Architecture Using 3-D Seismic Data: An Example from Hydrocarbon-Bearing Mumbai Offshore Basin, West Coast of India

    Science.gov (United States)

    Mukhopadhyay, D. K.; Bhowmick, P. K.; Mishra, P.

    2016-12-01

    In offshore sedimentary basins, analysis of 3-D seismic data tied with well log data can be used to deduce robust isopach and structure contour maps of different stratigraphic formations. The isopach maps give depocenters whereas structure contour maps give structural relief at a specific time. Combination of these two types of data helps us decipher horst-graben structures, sedimentary basin architecture and tectono-stratigraphic relations through Tertiary time. Restoration of structural cross sections with back-stripping of successively older stratigraphic layers leads to better understand tectono-sedimentary evolution of a basin. The Mumbai (or Bombay) Offshore Basin is the largest basin off the west coast of India and includes Bombay High giant oil/gas field. Although this field was discovered in 1974 and still producing, the basin architecture vis-à-vis structural evolution are not well documented. We take the approach briefly outlined above to study in detail three large hydrocarbon-bearing structures located within the offshore basin. The Cretaceous Deccan basalt forms the basement and hosts prodigal thickness (> 8 km at some localities) of Tertiary sedimentary formations.A two stage deformation is envisaged. At the first stage horst and graben structures formed due to approximately E-W extensional tectonics. This is most spectacularly seen at the basement top level. The faults associated with this extension strike NNW. At the second stage of deformation a set of ENE-striking cross faults have developed leading to the formation of transpressional structures at places. High rate of early sedimentation obliterated horst-graben architecture to large extent. An interesting aspect emerges is that the all the large-scale structures have rather low structural relief. However, the areal extent of such structures are very large. Consequently, these structures hold commercial quantities of oil/gas.

  10. Vertical-axis block rotations linked to normal faulting: paleomagnetic and structural evidence from Miocene to Recent extensional basins in southern Turkey

    Science.gov (United States)

    Koç, Ayten; van Hinsbergen, Douwe J. J.; Kaymakcı, Nuretdin; Langereis, Cornelis G.

    2017-04-01

    Paleomagnetism provides important constraints on complex patterns of vertical axis rotations in orogens. Where normally paleomagnetism is applied to constrain regional rotations, in the vicinity of fault zones often locally varying rotation patterns occur. Here we provide results of an extensive paleomagnetic survey constraining vertical axis rotation in Neogene extensional continental basins in the Taurides, in the eastern flank of the Isparta Angle (SW Turkey). In total, 437 oriented cores were sampled at 43 sites distributed within Miocene-Pliocene continental sedimentary rocks from the basins at the eastern limb (Ilgın and Altınapa Basins) and also central part (Yalvaç Basin) of the Isparta Angle. Despite the more or less coherent overall strike of the mountain belt and sedimentary basins, our results show different senses and varying amounts of vertical rotation within short distances; the Altınapa Basin has undergone only very minor rotations during and after the Miocene, but the paleomagnetic data from Yalvaç and Ilgın basins show 50° clockwise and 20° counter-clockwise rotation, respectively. Following a long history of shortening and thrusting, our study area has undergone regional extension since the mid-Miocene, which is still active in the present-day as portrayed by active seismicity, earthquake focal mechanisms, field data including fault plane solutions, and GPS measurements. This extension is accommodated along major normal faults that end in relay ramps with overlapping, adjacent normal faults. We show that the paleomagnetically determined rotations are related to such relay ramps, in places superimposed on rigid block rotations, and can be used as a first-order tool to quantify horizontal extension. As such, vertical axis rotations and paleomagnetism unravels important insights in the evolution of deformation in major normal fault zones.

  11. Innovative tidal notch detection using TLS and fuzzy logic: Implications for palaeo-shorelines from compressional (Crete) and extensional (Gulf of Corinth) tectonic settings

    Science.gov (United States)

    Schneiderwind, S.; Boulton, S. J.; Papanikolaou, I.; Reicherter, K.

    2017-04-01

    useful for the identification of palaeo-shorelines in extensional tectonic environments where coseismic footwall uplift (only 1/2 to 1/4 of net slip per event) is unlikely to raise an entire notch above the tidal range.

  12. The Unified Extensional Versioning Model

    DEFF Research Database (Denmark)

    Asklund, U.; Bendix, Lars Gotfred; Christensen, H. B.

    1999-01-01

    Versioning of components in a system is a well-researched field where various adequate techniques have already been established. In this paper, we look at how versioning can be extended to cover also the structural aspects of a system. There exist two basic techniques for versioning - intentional...

  13. 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.

  14. 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

  15. A Pyrenean Cretaceous extensional fault system in the Briançonnais Domain of the Alps: implications for the eastern termination of the segmented Bay of Biscay-Pyrenean rift system.

    Science.gov (United States)

    Tavani, Stefano; Bertok, Carlo; D'Atri, Anna; Piana, Fabrizio; Barale, Luca; Corradetti, Amerigo; Granado, Pablo; Martire, Luca; Vigna, Bartolomeo

    2017-04-01

    Recent studies in the foreland fold and thrust belt of the SW Alps reported that, in spite of the obliterating effect by the Alpine deformation, Mesozoic structures can still be recognised. These structures, occurring at the southern portion of the Western Alps arc, include a well-exposed crustal-scale Cretaceous extensional fault system. Field data (geological maps) and subsurface data (karst network) have been integrated to produce a detailed 3D reconstruction of this extensional fault system. Cretaceous faults affect the Paleozoic and Mesozoic successions and consist of a tens of km long E-W striking master fault, having in its northern block a set of E-dipping transverse extensional faults, having displacements in the order of hundreds of meters. The 3D reconstruction indicates that E-W extension, accommodated by transverse faults, is between 20% and 40%, and it reduces toward the E-W striking master fault. N-S extension is instead negligible and the E-W fault is interpreted as a Cretaceous right-lateral strike-slip fault. Removing the about 120° counter-clockwise vertical axis rotation, which is associated with the post-Cretaceous Alpine orogeny, the strike-slip fault becomes parallel to a suite of NNE-SSW to NE-SW striking faults occurring in the SW Alps foreland (present Provence region). We propose that, during the Cretaceous separation of Iberia from Eurasia, the NNE-SSW striking faults of Provence and Western Alps were delimiting to the east the Bay of Biscay - Pyrenean rift system. In detail, they formed a NNE-SSW striking transfer zone bounding to the east the Pyrenean arm of the rift, and likely ensured the connection of the Bay of Biscay - Pyrenean rift system with a further eastern, intra-plate, arm.

  16. Parametric study of the deformation of dispersion fuel plates; Estudo parametrico da deformacao de placas combustiveis com nucleos de dispersao

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, E.; Durazzo, M., E-mail: evieira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    The Nuclear and Energy Research Institute - IPEN-CNEN/SP produces routinely the nuclear fuel necessary for operating its research reactor, IEA-R1. This fuel consists of fuel plates containing U{sub 3}Si{sub 2}-Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed with base on information obtained from literature, which were used as premises for defining the current manufacturing procedures, according to a methodology with essentially empirical character. Despite the current rolling process to be perfectly stable and highly reproducible, it is not well characterized and therefore is not fully known. The objective of this work is to characterize the rolling process for producing fuel plates, presenting results of the evolution of all parameters of technological interest, after each rolling pass, obtaining information along the fuel plate deformation during the rolling process. (author)

  17. 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.

  18. 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...... is first established between two cylindrical disks. The upper disk is held fixed and may be connected to a force transducer while the lower cylinder falls due to gravity. By varying the mass of the falling cylinder and measuring its resulting acceleration, the viscoelastic nature of the elongating fluid...... filament can be probed. In particular, we show that with this constant force pull (CFP) technique it is possible to readily impose very large material strains and strain rates so that the maximum extensibility of the polymer molecules may be quantified. This unique characteristic of the experiment...

  19. Mesozoic­ and Cenozoic Tectono-depositional History of the Southwestern Chukchi Borderland: Implications of Pre-Brookian Passive-margin Slope Deposits for the Jurassic Extensional Deformation of the Amerasia Basin, Arctic Ocean

    Science.gov (United States)

    Ilhan, I.; Coakley, B.

    2016-12-01

    away from the East Siberian continental shelf, associated with the antecedent counter-clockwise rotation of the Arctic Alaska-Chukotka microplate away from the Canadian Arctic Islands and extensional deformation of the Amerasia Basin.

  20. Formation of the giant Chalukou porphyry Mo deposit in northern Great Xing'an Range, NE China: Partial melting of the juvenile lower crust in intra-plate extensional environment

    Science.gov (United States)

    Li, Zhen-Zhen; Qin, Ke-Zhang; Li, Guang-Ming; Ishihara, Shunso; Jin, Lu-Ying; Song, Guo-Xue; Meng, Zhao-Jun

    2014-08-01

    The Chalukou porphyry Mo deposit (2.46 Mt @ 0.087% Mo), located in the northern Great Xing'an Range, NE China, is the largest Mo deposit discovered in China so far. The host rocks consist of aplite porphyry, granite porphyry and quartz porphyry, and are intruded into Lower Ordovician intermediate-felsic volcanic-sedimentary rocks and pre-ore monzogranite and are cut by post-ore feldspar porphyry, diorite porphyry and quartz monzonite porphyry. Here, we present the zircon U-Pb ages, whole-rock geochemistry, Sr-Nd isotopic and zircon Hf isotopic data for the pre-ore, syn-ore and post-ore intrusive rocks. The Chalukou ore-forming porphyries intruded during 147-148 Ma and have high-silica, alkali-rich, metaluminous to slightly peraluminous compositions and are oxidized. They are enriched in large ion lithophile elements (e.g. K, Rb, U and Th), light REE and depleted in high-field strength elements (e.g. Nb, P and Ti). Depletions in Eu, Ba, Sr, Nb, Ta, P and Ti suggest that they have experienced strong fractional crystallization of plagioclase, biotite, hornblende and accessory minerals. The pre-ore monzogranite (~ 172 Ma) also belongs to the high-K calc-alkaline series. Highly fractionated REE patterns ((La/Yb) N = 19.6-21.7), high values of Sr/Y (54-69) and La/Yb (29-32), are adakite-like geochemical features. The post-ore rocks (~ 141-128 Ma) have similar geochemical characteristics with ore-forming porphyries except that quartz monzonite porphyry shows no Ba-Sr negative anomaly. All intrusive rocks have relative low initial 87Sr/86Sr (0.705413-0.707889) and εNd (t) values (- 1.28 to + 0.92), positive εHf (t) values (+ 2.4 to + 10.1) and young two-stage Nd and Hf model ages (TDM2 (Nd) = 863-977 Ma, TDM2 (Hf) = 552-976 Ma). These geochemical and isotopic data are interpreted to demonstrate that the ore-forming porphyries formed by partial melting of the juvenile lower crust caused by underplating of mafic magmas in an intra-plate extensional setting. The pre

  1. 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.

  2. Extensiones áulicas. Una oportunidad para seguir aprendiendo

    Directory of Open Access Journals (Sweden)

    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.

  3. 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.

  4. 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

  5. Extensiones centrales universales de álgebras Hom-Leibniz

    OpenAIRE

    Pacheco Rego, Natália Maria de Bessa

    2014-01-01

    Las álgebras Hom-Leibniz son espacios vectoriales V dotados de un producto corchete [-,-] : V × V → V y de una aplicación α : V --> V satisfaciendo la denominada identidad Hom-Leibniz: [α (x),[y,z

  6. 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.

  7. Violenza e repressione durante la dittatura civile-militare brasiliana: l’eredità dell’autoritarismo

    Directory of Open Access Journals (Sweden)

    Rafaella Bettamio

    2016-09-01

    Full Text Available Belief in the “enemy within” guided the national security for the Brazilian civil-military dictatorship, which was substantiated by high authoritarian legality. Together, these factors contributed to the consolidation of a highly centralized and violent system of information and repression, which had the DOI-CODI as its main character since 1970. The role of this institutional body, how this activity served to institutionalize the practice of police violence during the dictatorial period and how it lives up to the present are the points that we address in this article. Finally, we point out aspects of transitional justice that today are fundamental to combat the authoritarian legacies of that time in Brazil.

  8. Study on the radiation sensitivity of pathogenic Vibrionaceae and Enterobacteriaceae in vitro and after inoculation into oysters (Cassostrea brasiliana)

    International Nuclear Information System (INIS)

    Gelli, D.S.; Jakabi, M.; Del Mastro, N.; Rodrigues de Moraes, I.

    2001-01-01

    In vitro studies were conducted to evaluate the effects of ionizing radiation on various biotypes and serotypes of Vibrio cholerae (different biotypes and serotypes from group O1 and one strain from group O139); V. parahaemolyticus, V. vulnificus, V. fluvialis, Aeromonas hydrophila, Plesiomonas shigelloides; Salmonella typhi, S. enteritidis, S. typhymurium, Shigella flexneri and Escherichia coli O157:H7. In vivo tests were also conducted in oysters allowed to self-contaminate with V. cholerae and S. enteritidis cultures in sea water tanks through the natural feeding process of the mollusks. Bacterial populations irradiated (0.5-3.0 kGy) in pure culture in liquid broth or in oysters varied from 10 6 to 10 1 0 colony forming units per mL or gram (CFU/g or mL), respectively. The decrease in viable cells through the radiation dose range applied varied from 4 to 10 log 10 . The lowest radiation resistance was found in Vibrio spp. Aeromonas hydrophilia, and E. coli O157:H7, whereas S. enteritidis and S. typhimurium proved to be the most resistant species tested. A dose of 1.5 kGy was determined to be appropriate for elimination of up to 10 10 of bacteria tested except Salmonella spp. particularly, S. enteritidis, which required 3.0 kGy for complete elimination. Radiation doses of up to 3.0 kGy were not lethal to oysters. (author)

  9. Effect of cold working on nitriding process of AISI 304 and 316 austenitic stainless steel; Estudo da influencia da deformacao plastica na cinetica de nitretacao em acos inoxidaveis AISI 304 e 316

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Silvio Andre de Lima

    2012-07-01

    The nitriding behavior of AISI 304 and 316 austenitic stainless steel was studied by different cold work degree before nitriding processes. The microstructure, thickness, microhardness and chemical micro-composition were evaluated through optical microscopy, microhardness, scanner electronic microscopy and x ray diffraction techniques. Through them, it was observed that previous plastic deformations do not have influence on layer thickness. However, a nitrided layer thicker can be noticed in the AISI 304 steel. In addition, two different layers can be identified as resulted of the nitriding, composed for austenitic matrix expanded by nitrogen atoms and another thinner immediately below expanded by Carbon atoms. (author)

  10. Parametric study of the deformation of U{sub 3}Si{sub 2}-Al dispersion fuel plates; Estudo parametrico da deformacao de placas combustiveis com nucleos de dispersao U{sub 3}Si{sub 2}-Al

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Edeval

    2011-07-01

    The Nuclear and Energy Research Institute - IPEN-CNEN/SP produces routinely the nuclear fuel necessary for operating its research reactor, IEA-R1. This fuel consists of fuel plates containing U{sub 3}Si{sub 2}-Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed with base on information obtained from literature, which were used as premises for defining the current manufacturing procedures, according to a methodology with essentially empirical character. Despite the current rolling process to be perfectly stable and highly reproducible, it is not well characterized and therefore is not fully known. The objective of this work is to characterize the rolling process for producing fuel plates, specifically the evolution of dimensional parameters of the fuel plate as a function of its deformation in the rolling process. Results are presented in terms of the evolution of the thickness of the fuel meat and cladding of the fuel plate along the deformation, as well as the terminals defects, microstructure and porosity of the fuel meat. (author)

  11. Microstructural characterization of IF steel after severe plastic deformation via ARB and subsequent heat treatment; Caracterizacao microestrutural de um aco IF apos deformacao plastica severa via ARB e posterior recozimento

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, F.C.; Abrantes, A.L.A.; Lins, J.F.C., E-mail: cristinafo2@hotmail.co [Universidade Federal Fluminense (PPGEM/UFF), Volta Redonda, RJ (Brazil). Programa de Pos-graduacao em Engenharia Metalurgica

    2010-07-01

    This study aimed to evaluate the microstructural evolution of a titanium stabilized IF steel deformed to warm through the ARB process for 5 consecutive cycles and then annealing at 600 deg C for 1 h. The material was characterized with the aid of the techniques of scanning electron microscopy and electron backscatter diffraction (Electron Backscatter Diffraction - EBSD). An intense process of microstructural refinement was observed in the deformed material and the phenomenon of dynamic recovery was predominant. It can be concluded that the annealing of severely deformed material was not sufficient for a complete recrystallization of the microstructure. (author)

  12. Analysis of phase transformation occurring during deformation and recrystallization processes in Ti-Nb-Si alloys; Analise das transformacoes de fases ocorridas durante os processos de deformacao e recristalizacao em ligas de Ti-Nb-Si

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, H.J.R.; Batista, W.W.; Souza, S.A.; Dos Santos, D.F.D.; Lima, T.N.; Ramos, W.S., E-mail: helton_cabral@hotmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil)

    2014-07-01

    This paper presents an analysis of phase transformations in Ti-Nb-Si alloys. The alloys were produced in the arc furnace with a controlled atmosphere of argon and were then homogenized at 1000 ° for 8 hours and deformed by compression. The deformed alloys were recrystallized at the temperatures of 500, 600 and 700 ° C. Were used Optical Microscopy, Vickers Microhardness and X-ray Diffraction techniques in order to assess the effect of cold deformation and recrystallization processes in the hardness and phases present in the alloys. (author)

  13. Relationship between cold deformation, aging and microhardness of alloy Ti-35Nb-2,5Sn; Relacao entre deformacao a frio, envelhecimento e microdureza de ligas de Ti-35Nb-2,5Sn

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Igor Macedo; Santos, Arthur Fernando Amorim; Oliveira, Andre Filipe Barreto Rocha; Griza, Sandro, E-mail: igoor.inn@gmail.com, E-mail: arth_11n@hotmail.com, E-mail: andrefilipebro@gmail.com, E-mail: sandro_griza@gmail.com [Universidade Federal de Sergipe (UFS), Sao Cristovao, SE (Brazil)

    2014-07-01

    Alloys of titanium and niobium have been studied for biomedical applications because they have low modulus of elasticity. Research on Ti-Nb alloys with addition of tin comprise the state of the art in the subject. The Ti-35Nb-2,5Sn hot rolled alloy was used in the present study. Samples were machined and deformed in four levels of cold compression: 40%, 70%, 80% and 96%. Then the samples were subjected to aging at 900 ° C for 15 minutes. Further, microhardness tests, analysis and microscopic analysis of X-ray diffraction analysis for phase identification was carried out. It is observed that a degree of cold deformation of 80% followed by aging produces a substantial amplification of the hardness of the material. (author)

  14. 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...

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

    DEFF Research Database (Denmark)

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

    Local correlations in the orientation of neighboring molecules have been shown to exist both experimentally and theoretically for polymer melts, blends and networks. Such nematic interactions alter the stress-optic coefficient, but predict no change in the overall stress in long time scales in th...

  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. Measurement of Material Functions in Extensional Flow Using the Filament Stretch Rheometer

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.; Nielsen, Jens Kromann; Laille, Philippe

    2007-01-01

    The measurement of material functions other than startup and steady viscosity is demonstrated using the Filament Stretching Rheometer. This includes startup of uniaxial elongational flow (potentially until steady state) followed by stress relaxation, large amplitude oscillatory elongational flow ...... imposed upon a constant strain rate uni axial elongation and startup of uniaxial elongational flow followed by biaxial squeezing. The used Filament Stretching Rheometer allows measurements on polymeric fluids (including polymeric melts) from room temperatures until 200°C....

  19. Extensional flow of Newtonian and Boger fluids through a flow focusing microdevice

    OpenAIRE

    Oliveira, MSN; Pinho, FT; Alves, MA; 3rd Micro and Nano Flows Conference (MNF2011)

    2011-01-01

    This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute. ...

  20. Transverse systems along the extensional Tyrrhenian margin of central Italy and their influence on volcanism

    Science.gov (United States)

    Acocella, Valerio; Funiciello, Renato

    2006-04-01

    The Tyrrhenian margin of central Italy has undergone Plio-Quaternary extension, developing NW-SE normal faults and NE-SW faults. The NE-SW faults decrease in frequency toward NE with the stretching factor β, becoming negligible for β fissure eruptions are mostly controlled by NE-SW faults. Structural field data show normal motions for 76% of NW-SE Quaternary faults and transtensive for 73% of NE-SW Quaternary faults. Analogue experiments simulating the NE-SW Tyrrhenian extension show that transverse transtensive faults form with differential extension Δβ > 0.21. These data suggest that the NE-SW transtensive structures are transfer faults of the NW-SE normal faults due to relevant differential extension (Δβ > 0.21) within a stretched crust (β > 1.3). The minor dip-slip and strike-slip components of the NE-SW and NW-SE faults, respectively, possibly result from the NW-SE extension due to the southeastward slab retreat beneath the Calabrian arc. The NE-SW and NW-SE extensions in the central southern Tyrrhenian Sea account for the composite kinematics of the NE-SW structures, which, in turn, exert a twofold role in controlling volcanism. Where their dip-slip component forms basins, the associated decompression induces magma accumulation (developing central volcanoes) at the intersection among NW-SE and NE-SW systems. Where transfer faults are mainly strike slip, their inferred subvertical attitude enhances their permeability to magma, accounting for the observed NE-SW fissure eruptions. Regional extension, forming NW-SE faults, enhances the overall generation and rise of magma along the margin, but NE-SW structures focus magma rise and emplacement at shallower levels.

  1. Magma traps and driving pressure: consequences for pluton shape and emplacement in an extensional regime

    Science.gov (United States)

    Hogan, John P.; Price, Jonathan D.; Gilbert, M. Charles

    1998-09-01

    The level of emplacement and final form of felsic and mafic igneous rocks of the Wichita Mountains Igneous Province, southwestern Oklahoma, U.S.A. are discussed in light of magma driving pressure, lithostatic load, and crustal magma traps. Deposition of voluminous A-type rhyolites upon an eroded gabbroic substrate formed a subhorizontal strength anisotropy that acted as a crustal magma trap for subsequent rising felsic and mafic magma. Intruded along this crustal magma trap are the A-type sheet granites (length/thickness 100:1) of the Wichita Granite Group, of which the Mount Scott Granite sheet is typical, and smaller plutons of biotite bearing Roosevelt Gabbro. In marked contrast to the subhorizontal granite sheets, the gabbro plutons form more equant stocks with flat roofs and steep side walls. Late Diabase dikes cross-cut all other units, but accompanying basaltic flows are extremely rare in the volcanic pile. Based on magmastatic calculations, we draw the following conclusions concerning the level of emplacement and the shape of these intrusions. (1) Magma can rise to a depth at which the magma driving pressure becomes negligible. Magma that maintains a positive driving pressure at the surface has the potential to erupt. (2) Magma ascent may be arrested at a deeper level in the crust by a subhorizontal strength anisotropy (i.e. crustal magma trap) if the magma driving pressure is greater than or equal to the lithostatic load at the depth of the subhorizontal strength anisotropy. (3) Subhorizontal sheet-intrusions form along crustal magma traps when the magma driving pressure greatly exceeds the lithostatic load. Under such conditions, the magma driving pressure is sufficent to lift the overburden to create the necessary space for the intrusion. (4) Thicker steep-sided stocks or batholiths, with flat roofs, form at crustal magma traps when the magma driving pressure approximates that of the lithostatic load. Under these conditions, the necessary space for the intrusion must be created by other mechanisms (e.g. stoping). (5) Subvertical sheets (i.e. dikes) form when the magma driving pressure is less than the lithostatic load at the level of emplacement.

  2. Gravity in extensional regimes: A case study in the Central Volcanic Region, New Zealand

    Science.gov (United States)

    Greve, A.; Stern, T. A.

    2017-12-01

    Using the interpretation of a large crustal seismic experiment conducted in 2009 as boundary model, we produced a sequence of new 2D gravity models for the central North Island in New Zealand. The Bouguer gravity field in the region ranges from -100 to 60 mGal and is dominated by the long wavelength signals of the subduction of the Pacific beneath the Australian plate along the Hikurangi margin and the transition from continental to oceanic lithosphere about the Bay of Plenty coast (NE New Zealand). Removal of these broad regional trends reveals the presence of a triangular shaped area, within the lines Taranaki-Coromandel and Taranaki - White Island, with negative anomalies between -30 and 60 mGal and positive anomalies around 10 mGal along the margins. This area, commonly referred to as the Central Volcanic Region (CVR) represents the continental continuation of the Lau-Havre, oceanic, back-arc rift basin. The Taupo Volcanic Zone forms the active eastern half of the CVR, where anomalously high heat output, geothermal activity and active volcanism occur. The new gravity model includes the presence of a 90km wide, ca. 10 km thick rift pillow of new underplated, lower crust between the depths of 15 and 25 km. A positive density contrast of 300 kg/m3 for this body is consistent with the observed seismic velocities (6.8 ≤ Vp ≤ 7.1 km/s). A ca. 2.5 km deep basin dominates the upper crustal structure and is about 50 km wide, infilled by low density volcaniclastics, with adopted average negative densities of -425 kg/m3. In the mid-crustal region, between 2.5 and 15 km depth, isostatic compensation requires a small density contrast of -110 kg/m3. This density contrast, with respect to a standard crustal model, can be ascribed to the presence of low density intrusives, within the old and now stretched crust. On the basis of this new crustal structure model we estimate a stretching factor (ß) for the old crust of 2-2.4. The intruded mid crust and the underplated new crust are most likely the primary sources of the impressive 4 GW heat output of the CVR.

  3. 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

    Leish model. The relaxation modulus G(t,) is measured using stress relaxation after a sudden shearing displacement and we experimentally determine the Rouse time R by observing strain-time separability G(t,)=G(t)h() for t>R. The transient elongational properties are measured using three distinct instruments......–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......We measure the viscoelastic properties of a highly entangled narrow molecular weight polyisoprene melt with approximately 280 entanglements per chain in steady and transient shear and in elongational flows. The storage and loss moduli of the melt are found to be well described by the Milner and Mc...

  4. Crustal Extensional Faulting Triggered by the 2010 Chilean Earthquake: The Pichilemu Seismic Sequence

    Science.gov (United States)

    Comte, D.; Farias, M.; Roecker, S. W.; Carrizo, D.

    2011-12-01

    The MW =8.8 south-central Chilean earthquake occurred on February 27th , 2010 is one of the largest event recorded by modern seismology. Its rupture area, located along the interplate contact between Nazca and South America was about 500 × 140 km2, striking parallel to the coast of South America and extending to about 45 km depth. Somewhat surprisingly, although there have been numerous aftershocks in the rupture zone, none of them has had a magnitude Mw greater than 6.5, except the one observed on January 2nd, 2011, almost one year after the mainshock, located in the southern edge of the rupture zone. The first largest aftershocks, (Mw=6.9 and Mw=7.0), occurred within 15 minutes of each other on 11 March 2010 within the overriding South American plate at the northern tip of the rupture zone near the city of Pichilemu. These events are part of a sequence of normal faulting activated by the Maule earthquake. The purpose of this study is to document the first well-recorded case of forearc faulting due to a subduction megathrust earthquake in the Andean region. We combine evidence from local seismicity, Global Centroid-Moment Tensor (gCMT) focal solutions, and geological-geomorphological observations to provide some context for the 11 March sequence in the framework of the 27 February megathrust. We hypothesize that the megathrust earthquake produced alterations on the stress field, enhancing fluid circulation in the forearc, which finally triggered intraplate faulting in regions of pre-existing crustal weakness. In this study, we focus on the sequence of events associated with the March 11th aftershocks, which we name the Pichilemu seismic sequence, in particular on a swarm of 350 events with M > 4 that occurred within the first 24 hours after the largest aftershocks, and the two largest subsequent events, a Mw=5.9 and a Mw=5.3 that occurred on May 2nd and May 21th, 2010 respectively. The hypocenters located in our final 3D model body-wave velocity model, define a 35×25 km2 rupture zone striking N30°-35°W. The seismic zone dips 40°-50° to the SW and extends down to the subduction interface. The strike and dip of the zone are consistent with one of the nodal planes of the gCMT focal mechanisms for the two largest March 11th earthquakes. From this result, we conclude that the Pichilemu events occurred on crustal faults located in the coastal forearc region rather than in the interplate region of the main shock and can be considered as a coseismic expression of the Mw =8.8, 2010 megathrust earthquake. This rupture is well correlated with neotectonic expressions at this zone, which indicates that this kind of event is a long-term feature of this margin.

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

    DEFF Research Database (Denmark)

    Rasmussen, Henrik K.

    2016-01-01

    Dynamics; Clarendon Press: Oxford (1986)]. ρ is the density, R the gas constant, T the temperature and GN0 the plateau modulus. The method by [M.H. Wagner, S. Kheirandish, O. Hassager, Journal of Rheology 49 (6) (2005) 1317–1327, G. Marrucci, G. Ianniruberto, Macromolecules 37 (10) (2004) 3934....... 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...

  6. 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...... the orthogonal ESTRID-1 profile and the Eugeno-S profile 2. This high velocity zone in the middle to lower crust is interpreted as a mafic intrusion, which explains a positive gravity anomaly of ~50 mGal (Silkeborg Gravity High). The total length of the intrusion is at least 80 km in the east-west direction......P signal is very weak, due to the small velocity contrast between the lowermost crust (~7.4 km s-1) and uppermost mantle (~7.6-7.7 km s-1). The main Moho reflection has a 'reverberative' character to the south of the intrusion. This feature is interpreted by layering at the Moho level, possibly due...

  7. Constrictional strain during oblique rifting: A record from transtensional basins in the Gulf Extensional Province

    Science.gov (United States)

    Seiler, C.; Quigley, M.; Fletcher, J. M.

    2011-12-01

    Oblique opening of the Gulf of California provides a unique opportunity to study the mode of deformation in transtensional rift systems. Sedimentation in rifted basins is primarily controlled by the characteristics of the basin-bounding fault and the available sediment supply, and can thus be used as a proxy to understand tectonic processes during oblique shear. Transtensional basins are generally seen as composites between rift and pull-apart basins, with facies distributions that are controlled by interacting normal and strike-slip faults. Yet, transtensional shear may also be accommodated by more distributed constrictional strain that is not localised along fault zones. The Santa Rosa basin, located in the Sierra San Felipe of northern Baja California, is one of a series of transtensional syn-rift basins along the oblique-divergent plate boundary of the northern Gulf of California. The basin represents an asymmetric half-graben in the hanging wall of the Santa Rosa detachment, a low-angle normal fault with ~4-5km of E- to SE-directed displacement. The basin-fill dips NW into the detachment and displays form lines that mimic the corrugations of the detachment. The basin is broadly sigmoidal in shape, is truncated in the south by a dextral transfer zone and pinches out against the hanging wall basement in the north. The syn-rift stratigraphy is dominated by a sequence of alluvial fans shed from the hanging wall and footwall that interfinger with fine grained playa deposits. Stratigraphic analysis reveals systematic basin-scale variations in facies distributions, both along and across the axis of the basin. In a transverse direction, the basin-fill records a fining-upward cycle from conglomerate at the base to alternating sandstone-mudstone in the depocentre, which in turn interfingers with the proximal fault-scarp facies of the Santa Rosa detachment. Facies patterns also vary parallel to the basin axis even though finite displacement on the detachment was comparable along the length of the basin, indicating that different depositional environments were active at any one time. Importantly, the depocentre facies evolved progressively further upsection and thus later towards the southern Santa Rosa basin, where the detachment enters a broad synformal domain. Moreover, only the proximal (conglomeratic) fan facies developed in the eastern part of the basin, which lies adjacent to a major antiformal corrugation of the detachment. These relationships suggest that changes in the depositional environment are genetically linked to the corrugations of the detachment fault, which represent upright open folds that formed in the N-S constrictional strain regime of the transtensional plate boundary. The upward vertical deflection caused by antiformal folding led to increased uplift in both foot- and hanging wall, thereby choking the basin with coarse conglomerate and breccia. By comparison, the downward deflection in the synformal domain resulted in a lowering of the surface and the development of a well-established depocentre in the southern Santa Rosa basin.

  8. Segmentation pattern and structural complexities in seismogenic extensional settings: The North Matese Fault System (Central Italy)

    Science.gov (United States)

    Ferrarini, Federica; Boncio, Paolo; de Nardis, Rita; Pappone, Gerardo; Cesarano, Massimo; Aucelli, Pietro P. C.; Lavecchia, Giusy

    2017-02-01

    We investigated the northern slope of the Matese Mts. (Molise, Central Italy) with the aim of characterizing the N- to NE-dipping active normal fault system in the Bojano basin, a sector of primary importance from a seismic hazard perspective. We collected field data to define the geometry and segmentation pattern of two sub-systems (Patalecchia-Colle di Mezzo and Bojano-Campochiaro). New evidence of late Quaternary faulting was obtained by exploiting well log interpretations. Kinematic analysis revealed the interaction of pre-Quaternary inherited (mainly E-W-striking) and newly formed (NW-SE-striking) normal faults. Slip accommodation through linkage was clearly noted in the case of the Patalecchia-Colle di Mezzo sub-system. Detailed topographic profiles across the active fault segments provided post-LGM (15 ± 3 kyr) slip rates up to ∼2 mm/yr which agree with the high deformation rates based on different approaches in the literature. Finally, the instrumental seismicity analysis constrained the bottom of the seismogenic layer to depths of 13-14 km, and the gathered information allowed us to reconstruct the North Matese seismogenic source. Its 3D geometry and dimensions agree with both the dimension-magnitude relationships and macroseismic information available for the 1805 earthquake (Mw 6.6), the main historical earthquake to have struck the Bojano basin.

  9. 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....... Using numerical modelling, we show how these diverse rifting scenarios are unified when accounting for varying mantle potential temperature. At a temperature of 1300 °C, cooling is plate-like with nearly exponential subsidence as observed in oceanic basins. At 1200 °C, subsidence is almost linear...... 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...

  10. Style of extensional tectonism during rifting, Red Sea and Gulf of Aden

    Science.gov (United States)

    Bohannon, R. G.

    Models describing the development of the Red Sea and the Gulf of Aden, prior to the present periods of sea-floor spreading, include those that use block faulting on steep normal faults, uniform diffuse shear in continental crust, simple shear on large detachment faults that cut the entire lithosphere, combinations involving detachment faults/ductile deformation/plutonic inflation, and ones that minimize the role of mechanical extension in favor of an earlier stage of sea-floor spreading. Geologic and geophysical studies from the Arabian continental margin in the southern Red Sea and LANDSAT analysis of the northern Somalia margin in the Gulf of Aden suggest that the early continental rifts were long narrow features that formed by extension on closely spaced normal faults above moderate- to shallow-dipping detachments with break-away zones defining one rift flank and root zones under the opposing rift flank. The rift flanks presently form the opposing continental margins across each ocean basin. The detachment on the Arabian margin dips gently to the west, with a breakaway zone now eroded above the deeply dissected terrain of the Arabian escarpment. The Arabian detachment projects westward to middle crustal levels beneath the sediment of the southern Red Sea coastal plain. Strata in the upper plate dip as steeply as 60° to the west, and the beds are repeated by numerous planar and listric normal faults that dip to the east. Most of the faults truncate downward at the detachment. Thus, the upper plate is highly extended and the rocks in its eastern part have been translated about 20 km westward and 21/2- to 5-km downward relative to the rest of Arabia. A prominent detachment surface, with a north dip, is evident in northernmost Somalia where it breaks away north of the Somalian escarpment in an otherwise undeformed section of cratonic strata of Jurassic to Eocene age. The upper plate of the Somalian detachment consists of a highly faulted collage of the cratonic strata. This fault projects to middle crustal levels in the opposing Arabian margin to the northeast. A model is proposed in which upper crustal breakup occurs on large detachment faults that have a distinct polarity. Most of the intense faulting is confined to the upper plates of the detachments, which root in the middle crust. Deeper extension is accommodated chiefly by ductile shear that results in vertical uplift, thinning, and lateral expansion of the rocks of the lower crust and the lithospheric mantle. Thus, lithospheric thinning, the thermal anomaly associated with it, and nearly all isostatic effects of rifting are confined to the area of the rift, its flanks, or directly beneath it. Tholeiitic magmatism began, on the Arabian margin, once the crust had thinned to 20-25 km. It is proposed that most of the continental divergence was accommodated by disorganized plutonic expansion after that, rather than by mechanical extension, until the present system of organized sea-floor spreading was established.

  11. 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.

  12. 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

    Since its inception, the tube model of polymer dynamics has undergone several modifications to account for observed experimental trends. One trend that has yet to be captured by a modified version of the tube model is the observed experimental difference between concentrated polymer solutions...... per chain and are diluted in the same solvent (oligomeric styrene). We show that the difference in nonlinear rheological behavior between polystyrene melts reported by Bach et al.1 and polystyrene solutions reported by Bhattacharjee et al.2 and Sridhar et al.3 can be bridged by changing...... the polystyrene concentration. The results presented represent a unique benchmark for all future modifications to the tube model....

  13. Thermomechanics of an extensional shear zone, Raft River metamorphic core complex, NW Utah

    Science.gov (United States)

    Gottardi, Raphaël; Teyssier, Christian

    2013-08-01

    A detailed structural and microstructural analysis of the Miocene Raft River detachment shear zone (NW Utah) provides insight into the thermomechanical evolution of the continental crust during extension associated with the exhumation of metamorphic core complexes. Combined microstructural, electron backscattered diffraction, strain, and vorticity analysis of the very well exposed quartzite mylonite show an increase in intensity of the rock fabrics from west to east, along the transport direction, compatible with observed finite strain markers and a model of ``necking'' of the shear zone. Microstructural evidence (quartz microstructures and deformation lamellae) suggests that the detachment shear zone evolved at its peak strength, close to the dislocation creep/exponential creep transition, where meteoric fluids played an important role on strain hardening, embrittlement, and eventually seismic failure. Empirically calibrated paleopiezometers based on quartz recrystallized grain size and deformation lamellae spacing show very similar results, indicate that the shear zone developed under stress ranging from 40 MPa to 60 MPa. Using a quartzite dislocation creep flow law we further estimate that the detachment shear zone quartzite mylonite developed at a strain rates between 10-12 and 10-14 s-1. We suggest that a compressed geothermal gradient across this detachment, which was produced by a combination of ductile shearing, heat advection, and cooling by meteoric fluids, may have triggered mechanical instabilities and strongly influenced the rheology of the detachment shear zone.

  14. 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...

  15. 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...

  16. 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.

  17. Análise populacional de Anomalocardia brasiliana (Gmelin, 1791, na Praia do Saco da Ribeira, Ubatuba, Estado de São Paulo

    Directory of Open Access Journals (Sweden)

    Y Schaeffer-Novelli

    1980-12-01

    Full Text Available Monthly quantitative sampling of the beach benthic macro fauna was made from June 1972 through December 1974. Determinations of the distribution index, length |dry weight correlation and vertical distribution pattern was also made.

  18. “A Janela” e l'ambiguità del reale: invenzione e memoria nel racconto della scrittrice brasiliana Lygia Fagundes Telles

    Directory of Open Access Journals (Sweden)

    Luigia De Crescenzo

    2015-01-01

    Full Text Available This essay aims at analysing the role of the window in “A Janela”, a short story written by Lygia Fagundes Telles published for the first time in the collection O Jardim Selvagem (1965 and then republished in Antes do Baile Verde (1977. In this short story an old man returns to a room only to see the window that reminds him of his son who is dead. His reminiscences, revealed through a dialogue with the woman who lives in the room, modify the narrative structure: the transition from the present to the past discloses an introspection that makes the narration ambiguous and leads the woman – and also the reader – to suspect that the man is insane. In this way the text results in a Chinese box structure: “A Janela” contains its miniature, that is, the window which, by causing reminiscences of the man, turns out to be a sort of emblem of that “creative process” that, through the intersection of memory and fiction, defines Lygia Fagundes Telles' literary works. Starting from the analysis of metaphorical and symbolical meanings ascribed to the window as “subject-object” of the narration, this essay will also place emphasis on the combination of memory and fiction as one of the main stylistic mark of the writer's works in order to interpret “A Janela” as a sort of mise en abîme of the whole literary production of Lygia Fagundes Telles'.

  19. Ferrite re-crystallization kinetics on a C-Mn steel and on two micro alloyed steels after dual-phase strain; Cinetica de recristalizacao da ferrita em um aco C-Mn e dois acos microligados apos deformacao na regiao bifasica

    Energy Technology Data Exchange (ETDEWEB)

    Simieli, Eider A. [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil)

    1991-12-31

    Ferrite recrystallization was investigated in two micro alloyed steels deformed in the inter critical range. A reference steel was also used, which had a composition of 0,06% C and 1,31% Mn. (author). 15 refs., 7 figs., 3 tabs.

  20. Meso and microscopic characterization of deformation bands in porous sandstones: an example on the Paleozoic, Pre- and Sin-rift sequences of the Araripe Basin, Northeast of Brazil; Caracterizacao meso e microscopica de bandas de deformacao em arenitos porosos: um exemplo nas tectonossequencias Paleozoica, Pre- e Sin-rifte da Bacia do Araripe, Nordeste do Brasil

    Energy Technology Data Exchange (ETDEWEB)

    Araujo Neto, Joao Marculino de; Silva, Fernando Cesar Alves da; Sa, Emanuel Ferraz Jardim de [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil). Programa de Pos-Graduacao em Geodinamica e Geofisica], e-mails: jota_ex2@hotmail.com, fernando@geologia.ufrn.br, emanuel@ccet.ufrn.br

    2012-04-15

    Deformation bands are narrow tabular volumes developed in porous sandstones. Although these structures are a product of brittle deformation, they may have internally a continuous displacement gradient. When granular cataclasis is the dominant deformation mechanism, the initial properties of their host rocks (i.e., porosity and permeability) can change significantly. The deformation bands in sandstones from the pre- and syn-rift of the Araripe Basin were studied in meso and microscale in order to classify them and to understand the deformation mechanisms involved during their nucleation and development. Their geometric-spatial, kinematic, and rheological criteria allowed establishing relations between the origin of deformation bands and lithification of their host rocks. Additionally, some inferences on their influence to the fluid flow in the reservoir-scale were outlined. Moreover, the study of deformation bands contributed to the understanding of the tectonic evolution of the studied basin. Accordingly, the study of deformation bands can support research on local and regional aspects of the tectonosedimentary evolution of sedimentary basins. (author)

  1. Study of deformation and fracture micro mechanisms of titanium alloy Ti-6Al-4V using electron microscopy and and X-ray diffraction techniques; Estudo dos micromecanismo de deformacao e fratura da liga de titanio Ti-6Al-4V utizando-se tecnicas de microscopia eletronica e difracao de raios X

    Energy Technology Data Exchange (ETDEWEB)

    Morcelli, Aparecido Edilson

    2009-07-01

    This present work allowed the study of deformation and fracture micro mechanisms of titanium alloy Ti-6Al-4V, used commercially for the manufacture of metallic biomaterials. The techniques employed for the analysis of the material under study were: scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The study of the influence and behavior of the phases present in titanium alloys is important to evaluate the behavior of cracks in titanium alloys with high mechanical strength, which have fine alpha ({alpha}), beta ({beta}) and ({alpha}{+-}{beta}) microstructure, linking the presence of the phases with the strength of the material. The evaluation in situ of deformation and fracture micro mechanisms were performed by TEM and was also a study of phase transformations during cooling in titanium alloys, using the techniques of bright field, dark field and diffraction of electrons in the selected area. After heat treatment differences were observed between the amount of in relation to the original microstructure of the {beta} and {alpha} phases material for different conditions used in heat treatment applied to the alloy. The presence of lamellar microstructure formed during cooling in the {beta} field was observed, promoting the conversion of part of the secondary alpha structure in {beta} phase, which was trapped between the lamellar of alpha. (author)

  2. 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.

  3. Hydrodynamic alignment and assembly of nano-fibrillated cellulose in the laminar extensional flow: Effects of solidifying agents

    Science.gov (United States)

    Mittal, Nitesh; Lundell, Fredrik; Soderberg, Daniel

    2015-11-01

    There are several fiber production technologies that are based on wet-spinning processes. Many such processes rely on the transformation of a liquid solution into a solid filament. The kinetics of solidification depends largely on the diffusion of the solvents, additives and polymer molecules, which make such systems quite complex and differ from a system to another as a function of the specific chemical, physical and structural features of the used material components. Moreover, tuning the orientation of the polymers in the liquid suspensions makes it further possible to control their structure, which in turn can lead to materials having improved properties. By keeping in mind the facts mentioned above, the aim of the current study is to utilize benefits of a flow focusing approach to align carboxymethylated cellulose nanofibrils (CNF), as a colloidal dispersion, with the help of a laminar elongational flow-field followed by the solidification using different solidifying agents or molecules (with dissimilar diffusion behavior based on their size and charges) to synthesize fibers with enhanced mechanical properties. CNF are charged elongated particles obtained from woods with diameter of 4-10 nm and length of 1-1.5 μm, and they are completely biodegradable.

  4. 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.

  5. Exploración de repositorios de software y análisis de potenciales extensiones a aspectos

    Directory of Open Access Journals (Sweden)

    Graciela Beatriz Vidal

    2014-06-01

    Full Text Available Tanto el Desarrollo basado en Componentes como el Desarrollo de Software orientado a Aspectos son enfoque propuestos para abordar diversos problemas que surgen en el proceso de desarrollo de aplicaciones. Ambos enfoques tienen como objetivo el reuso de software, ante esta situación surge la necesidad de que componentes y aspectos compartan un espacio común en el cual puedan ser publicados, recuperados y reutilizados. Los repositorios actuales parecen no proveer aspectos de manera explícita, en ocasiones los aspectos son utilizados para especificar el componente, pero no son reusables. La tarea de publicar y recuperar componentes es muy compleja, existen diversos métodos de publicación y recuperación a tal fin. En este trabajo se exploraron diferentes repositorios analizando criterios al igual que se exponen los métodos de publicación y recuperación con el fin de determinar si es posible la adaptación o extensión de los repositorios a aspectos.

  6. Translational and extensional energy release rates (the J- and M-integrals) for a crack layer in thermoelasticity

    Science.gov (United States)

    Chudnovsky, A.; Gommerstadt, B.

    1985-01-01

    A number of papers have been presented on the evaluation of energy release rate for thermoelasticity and corresponding J integral. Two main approaches were developed to treat energy release rate in elasticity. The first is based on direct calculation of the potential energy rate with respect to crack length. The second makes use of Lagrangian formalism. The translational and expansional energy release rates in thermoelasticity are studied by employing the formalism of irreversible thermodynamics and the Crack Layer Approach.

  7. 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.

  8. Demoliendo barreras de pago : Extensiones de navegadores web para descubrir artículos en acceso abierto

    OpenAIRE

    Merlino Santesteban, Cristian

    2017-01-01

    Una de las mayores frustraciones que debe afrontar un científico cada vez que localiza el resumen de un artículo potencialmente relevante para su investigación es toparse con una barrera de “pago por acceso”. La búsqueda de información académica en la Web lleva tiempo, paciencia y dedicación y qué peor desenlace para dicha tarea que encontrarse con la imposibilidad de acceder a textos completos por no mediar un pago previo. Naturalmente, este tipo de restricción se presenta con mayor frecuenc...

  9. 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.

  10. 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.

  11. Building the Pamir-Tibet Plateau—Crustal stacking, extensional collapse, and lateral extrusion in the Pamir: 3. Thermobarometry and petrochronology of deep Asian crust

    Science.gov (United States)

    Hacker, Bradley R.; Ratschbacher, Lothar; Rutte, Daniel; Stearns, Michael A.; Malz, Nicole; Stübner, Konstanze; Kylander-Clark, Andrew R. C.; Pfänder, Jörg A.; Everson, Alexa

    2017-09-01

    Large domes of crystalline, middle to deep crustal rocks of Asian provenance make the Pamir a unique part of the India-Asia collision. Combined major-element and trace element thermobarometry, pseudosections, garnet-zoning deconstruction, and geochronology are used to assess the burial and exhumation history of five of these domes. All domes were buried and heated sufficiently to initiate garnet growth at depths of 15-20 km at 37-27 Ma. The Central Pamir was then heated at 10-20°C/Myr and buried at 1-2 km/Myr to 600-675°C at depths of 25-35 km by 22-19 Ma. The Shakhdara Dome in the South Pamir was heated at 20°C/Myr and buried at 2-8 km/Myr to reach 750-800°C at depths of ≥50 km by 20 Ma. All domes were exhumed at >3 km/Myr to 5-10 km depths and 300°C by 17-15 Ma. The pressures, temperatures, burial rates, and heating rates are typical of continental collision. Decompression during exhumation outpaced cooling, compatible with tectonic unroofing along mapped large-scale, normal-sense shear zones, and with advection of near-solidus or suprasolidus temperatures into the upper crust, triggering exhumation-related magmatism. The Shakhdara Dome was exhumed from greater depth than the Central Pamir domes perhaps due to its position farther in the hinterland of the Paleogene retrowedge and to higher heat input following Indian slab breakoff. The large-scale thickening and coincident 20 Ma switch to extension throughout a huge area encompassing the Pamir and Karakorum strengthens the idea that the evolution of orogenic plateaux is governed by catastrophic plate-scale events.

  12. The Rheological Evolution of Brittle-Ductile Transition Rocks During the Earthquake Cycle: Evidence for a Ductile Precursor to Pseudotachylyte in an Extensional Fault System, South Mountains, Arizona

    Science.gov (United States)

    Stewart, Craig A.; Miranda, Elena A.

    2017-12-01

    We investigate how the rheological evolution of shear zone rocks from beneath the brittle-ductile transition (BDT) is affected by coeval ductile shear and pseudotachylyte development associated with seismicity during the earthquake cycle. We focus our study on footwall rocks of the South Mountains core complex, and we use electron backscatter diffraction (EBSD) analyses to examine how strain is localized in granodiorite mylonites both prior to and during pseudotachylyte development beneath the BDT. In mylonites that are host to pseudotachylytes, deformation is partitioned into quartz, where quartz exhibits crystallographic-preferred orientation patterns and microstructures indicative of dynamic recrystallization during dislocation creep. Grain size reduction during dynamic recrystallization led to the onset of grain boundary sliding (GBS) accommodated by fluid-assisted grain size-sensitive (GSS) creep, localizing strain in quartz-rich layers prior to pseudotachylyte development. The foliation-parallel zones of GBS in the host mylonites, and the presence of GBS traits in polycrystalline quartz survivor clasts indicate that GBS zones were the ductile precursors to in situ pseudotachylyte generation. During pseudotachylyte development, strain was partitioned into the melt phase, and GSS deformation in the survivor clasts continued until crystallization of melt impeded flow, inducing pseudotachylyte development in other GBS zones. We interpret the coeval pseudotachylytes with ductile precursors as evidence of seismic events near the BDT. Grain size piezometry yields high differential stresses in both host mylonites ( 160 MPa) and pseudotachylyte survivor clasts (> 200 MPa), consistent with high stresses during interseismic and coseismic phases of the earthquake cycle, respectively.

  13. 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.

  14. 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.

  15. Rapid extensional unroofing of a granite-migmatite dome with relics of high-pressure rocks, the Podolsko complex, Bohemian Massif

    Czech Academy of Sciences Publication Activity Database

    Žák, J.; Sláma, Jiří; Burjak, M.

    2017-01-01

    Roč. 154, č. 2 (2017), s. 354-380 ISSN 0016-7568 Institutional support: RVO:67985831 Keywords : anisotropy of magnetic susceptibility (AMS) * granite-migmatite dome * exhumation * metamorphic core complex * U-Pb zircon geochronology Subject RIV: DB - Geology ; Mineralogy OBOR OECD: Geology Impact factor: 1.965, year: 2016

  16. Influence of lithosphere and basement properties on the stretching factor and development of extensional faults across the Otway Basin, southeast Australia

    NARCIS (Netherlands)

    Kharazizadeh, N.; Schellart, W. P.; Duarte, J.C.; Hall, M.

    2017-01-01

    The NW-SE striking Otway Basin in southeastern Australia is part of the continental rift system that formed during the separation of Australia from Antarctica. The development of this sedimentary basin occurred in two phases of Late Jurassic-Early Cretaceous and Late Cretaceous rifting. The

  17. 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.

  18. 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.

  19. 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...

  20. Surface analogue outcrops of deep fractured basement reservoirs in extensional geological settings. Examples within active rift system (Uganda) and proximal passive margin (Morocco).

    Science.gov (United States)

    Walter, Bastien; Géraud, Yves; Diraison, Marc

    2014-05-01

    The important role of extensive brittle faults and related structures in the development of reservoirs has already been demonstrated, notably in initially low-porosity rocks such as basement rocks. Large varieties of deep-seated resources (e.g. water, hydrocarbons, geothermal energy) are recognized in fractured basement reservoirs. Brittle faults and fracture networks can develop sufficient volumes to allow storage and transfer of large amounts of fluids. Development of hydraulic model with dual-porosity implies the structural and petrophysical characterization of the basement. Drain porosity is located within the larger fault zones, which are the main fluid transfer channels. The storage porosity corresponds both to the matrix porosity and to the volume produced by the different fractures networks (e.g. tectonic, primary), which affect the whole reservoir rocks. Multi-scale genetic and geometric relationships between these deformation features support different orders of structural domains in a reservoir, from several tens of kilometers to few tens of meters. In subsurface, 3D seismic data in basement can be sufficient to characterize the largest first order of structural domains and bounding fault zones (thickness, main orientation, internal architecture, …). However, lower order structural blocks and fracture networks are harder to define. The only available data are 1D borehole electric imaging and are used to characterize the lowest order. Analog outcrop studies of basement rocks fill up this resolution gap and help the understanding of brittle deformation, definition of reservoir geometries and acquirement of reservoir properties. These geological outcrop studies give information about structural blocks of second and third order, getting close to the field scale. This allows to understand relationships between brittle structures geometry and factors controlling their development, such as the structural inheritance or the lithology (e.g. schistosity, primary structures). Two field cases, located in Morocco and Uganda, allow us to investigate basement complexes at different stages of an extension process and give us analog geological data of similar fractured basement reservoirs. Border faults and associated fracture networks of an active rifting system propagated in Proterozoic basement rocks are analyzed in the Albertine rift system in Uganda. Brittle structures developed along a proximal passive margin of the Atlantic domain are analyzed in Proterozoic basements rocks in Western Anti-Atlas in Morocco.

  1. 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.

  2. 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

  3. 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.

  4. 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).

  5. 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.

  6. 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

  7. 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.

  8. THE PESTICIDAL POTENTIAL OF Alternanthera bransiliana (L.) O. KUNTZE IN SOLVING PEST PROBLEM IN ORGANIC AGRICULTURE

    OpenAIRE

    Fayinminnu , Olajumoke Oke; Shiro, Olawale Oreoluwa

    2014-01-01

    This study was carried out at the Teaching and Research Farm of University of Ibadan, Nigeria between March and May 2013, to evaluate the pesticidal potential of Alternanthera brasiliana on Hymenia recurvalis pest of Amaranthus cruentus.

  9. Celulas solares e sensores de filme fino de silicio depositados sobre substratos flexiveis =

    Science.gov (United States)

    Pinto, Emilio Sergio Marins Vieira

    Celulas solares flexiveis de filmes finos de silicio sao geralmente fabricadas a baixa temperatura sobre substratos de plastico ou a mais elevadas temperaturas sobre folhas de aco. Esta tese reporta o estudo da deposicao de filmes finos sobre diferentes substratos de plastico, transparentes e coloridos, para celulas solares do tipo sobrestrato e substrato, respectivamente. Como objetivo co-lateral, os filmes dopados depositados sobre plastico foram usados como sensores de deformacao, utilizando as suas propriedades piezo-resistivas. Elevadas taxas de deposicao dos filmes de silicio depositados sobre plastico foram obtidas a baixa temperatura do substrato (150ºC) por rf-PECVD. A influencia de diferentes parametros de deposicao sobre as propriedades e taxa de deposicao dos filmes resultantes foram estudados e correlacionados. Celulas solares de filmes finos de silicio amorfo e microcristalino foram desenvolvidas a baixas temperaturas sobre plasticos. Eficiencias de 5 – 6.5% foram alcancadas para as celulas amorfas e 7.5% para as celulas microcristalinas. Efeitos de aprisionamento da luz foram estudados atraves da texturizacao por ablacao laser de substratos de plastico e corrosao umida de TCO sobre plastico. Filmes finos de silicio microcristalino, depositados por HW-CVD, com fator piezoresistivo de -32.2, foram usados para fabricar sensores de deformacao em uma membrana plastica muito fina (15 μm). Estruturas de teste em textil e a miniaturizacao dos sensores piezoresistivos depositados sobre substratos flexiveis de poliimida foram abordados.

  10. 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

  11. 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.

  12. 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)

  13. 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.

  14. SABACO: Extensiones a los Algoritmos de Optimización basados en Colonias de Hormigas para la Toma de Decisiones Influenciada por Emociones y el Aprendizaje de Secuencias Contextuales en Ambientes Inteligentes

    OpenAIRE

    Mocholi Agües, Jose Antonio

    2011-01-01

    En el trabajo que presentamos en esta tesis hacemos inicialmente una revisión de cómo ha ido evolucionando la interacción hombre máquina en el contexto de la computación, desde los primeros y escasos computadores hasta el momento actual, en el que los avances tecnológicos han permitido que, en muchos de los escenarios en los que se desarrolla nuestra vida diaria, estemos rodeados de diversos dispositivos electrónicos con los que interactuamos para hacer uso de alguno de los servicios que ofre...

  15. La scuola tra gli xacriabá: tra sviluppo economico e innovazione didattica

    Directory of Open Access Journals (Sweden)

    Filippo Lenzi Grillini

    2013-07-01

    Full Text Available “Comunitaria, interculturale, bilingue, specifica e differenziata”, secondo il documento ministeriale “Diretrizes para a politica nacional de educação escolar indígena”sono queste le caratteristiche fondamentali che devono contraddistinguere ogni scuola indigena brasiliana.

  16. 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...

  17. 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.

  18. New Limonoids from Hortia oreadica and Unexpected Coumarin from H. superba Using Chromatography over Cleaning Sephadex with Sodium Hypochlorite

    OpenAIRE

    Severino, Vanessa; Freitas, Sâmya de; Braga, Patrícia; Forim, Moacir; Silva, M. da; Fernandes, João; Vieira, Paulo; Venâncio, Tiago

    2014-01-01

    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...

  19. CHEMICAL STUDY OF Hortia superba (Rutaceae) AND INVESTIGATION OF THE ANTIMYCOBACTERIAL ACTIVITY OF CRUDE EXTRACTS AND CONSTITUENTS ISOLATED FROM Hortia SPECIES

    OpenAIRE

    Severino, Vanessa Gisele Pasqualotto; Felix, Monteiro Afif; Silva, Maria Fátima das Graças Fernandes da; Lucarini, Rodrigo; Martins, Carlos Henrique Gomes

    2015-01-01

    In this paper, the chemical study of Hortia superba and antimycobacterial potential of Hortia species were investigated. Crude extracts and limonoids, alkaloids, dihydrocinnamic acid derivatives and coumarins isolated from Hortia superba, Hortia oreadica and Hortia brasiliana were evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium kansasii and Mycobacterium avium. The results obtained demonstrated an inhibitory effect of the dichloromethane extract of leaves of H. oreadica (MIC...

  20. La simbologia identitaria nei motivi dell’esordio poetico di Giuseppe Ungaretti

    OpenAIRE

    Ceccarelli, Marilena

    2017-01-01

    Dalla nascita ad Alessandria d’Egitto, passando per l’incontro con l’Italia, la Terra Promessa dei suoi genitori, sino alle feconde esperienze parigina e brasiliana, Ungaretti traspone nei suoi versi la percepita condizione di esule deraciné alla continua ricerca di una sistemazione identitaria che continua a non trovare soluzione. Il contributo intende indagare le tappe dell’itinerario poetico ungarettiano rivolto alla ricerca e alla definizione di una simile dimensione, rilevando come le ma...

  1. Criterios del Consejo de Evaluación, Acreditación y Aseguramiento de la Calidad de Educación superior y su influencia en la calidad de la educación de las extensiones universitarias de la provincia de Manabí - Ecuador

    OpenAIRE

    Villacis Zambrano, Lilia Moncerrate

    2017-01-01

    Determina el cómo influye la acreditación que otorga el Consejo de Acreditación y Aseguramiento de la Calidad de Educación Superior (CEAACES) en la calidad de las universidades. Para ello se utiliza encuestas, muestreo, método de expertos Kendall, diagramas causa-efecto, diagramas de flujo y análisis. Para el procesamiento y análisis de la información se utiliza el software SPSS, Microsoft, Excel, Word y otros. Los resultados de esta investigación sirve de base para proponer una serie de acci...

  2. 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.

  3. Temperature Dependence of the Elongation Behavior of Polyphenylene Sulfide using Melt Spinning Technique

    Science.gov (United States)

    Tan, Changbin; Yang, Yan; Gao, Jun; Li, Shenghu; Qing, Long

    2017-12-01

    The elongational properties of polyphenylene sulfide (PPS) melt were measured using a melt spinning technique. The relationship between extrusion temperature and melt strength (MS) as well as between elongational viscosity and drawability were investigated with respect to the effects of extrusion temperature and extensional strain rate on the melt extensional stress and elongational viscosity. The results showed that the stretching force for the PPS melt decreased with a rise of extrusion temperature while increased roughly with an increase of extensional rate. The MS decreased with an increase of temperature, and the ln MS was a linear function of 1/T when the extrusion velocity was constant. Both the melt extensional stress and elongational viscosity decreased with the increase of the extrusion temperature. With increase of the extensional strain rate, the extensional stress increased while the melt elongational viscosity first decreases and then increases gradually. A low melt elongational viscosity might be beneficial to improve the melt drawability.

  4. Investigation of thermal degradation of branched polypropylene via rheology

    Science.gov (United States)

    Drabek, Jiri; Zatloukal, Martin

    2015-04-01

    In this work, virgin as well as thermally degraded branched polypropylenes were investigated by using rotational and Sentmanat extensional rheometers. Based on the shear and extensional rheology data it was deduced that both chain scission and chain branching takes place during thermal degradation of the tested polypropylene. It was found that simple phenomenological constitutive equations such as Generalized Newtonian law and modified White Metzner model can be used to describe the measured steady state shear and uniaxial extensional viscosity data as well as for the simple quantification of the extensional strain hardening via their model parameters.

  5. In vitro antiplasmodial activity of medicinal plants native to or naturalised in South Africa

    CSIR Research Space (South Africa)

    Clarkson, C

    2004-06-01

    Full Text Available Journal of Biomedical Science 60, 89?91. Alves, T.M., Nagem, T.J., de Carvalho, L.H., Krettli, A.U., Zani, C.L., 1997. Antiplasmodial triterpenes from Vernonia brasiliana. Planta Medica 63, 554?555. Arnold, T.H., Prentice, C.A., Hawker, L.C., Snyman, E... of Ethnopharmacology 56, 1?13. Clarkson, C., Campbell, W.E., Smith, P., 2003. In vitro antiplasmodial activity of abietane and totarane diterpenes isolated from Harpagophy- tum procumbens (Devil?s Claw). Planta Medica 8, 720?724. Decosterd, L.A., Hoffmann, E., Kyburz...

  6. 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. 

  7. Estudo químico de plantas do gênero Hortia, do fungo Guignardia citricarpa e avaliação de seus potenciais efeitos biológicos

    OpenAIRE

    Vanessa Gisele Pasqualotto Severino

    2011-01-01

    O estudo químico de plantas do gênero Hortia descrito neste trabalho visou contribuir com a quimiossistemática da família Rutaceae e também com o posicionamento correto do gênero dentro da mesma. O estudo das espécies H. oreadica Groppo, Kallunki e Pirani, H. brasiliana Vand. ex DC. e H. superba Ducke levou ao isolamento de 21 substâncias: dez limonoides, três derivados do ácido diidrocinâmico, cinco alcaloides (dois furoquinolínicos, um 2-quinolona e dois indoloquinazolínicos) e três cumarin...

  8. 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...

  9. Flexural vibrations of finite composite poroelastic cylinders

    Indian Academy of Sciences (India)

    If the wavelength is infinite, frequency equations are degenerated as product of two determinants pertaining to extensional vibrations and shear vibrations. In this case, it is seen that the nature of the surface does not have any influence over shear vibrations unlike in the case of extensional vibrations. For illustration purpose ...

  10. Journal of Earth System Science | Indian Academy of Sciences

    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 ...

  11. 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 al...

  12. 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.

  13. 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

  14. An Examination of Upper Plate Aftershocks of the Tohoku-oki Earthquake: Are They Caused by a Long-term Change in the Dip of the Subducting Plate?

    Science.gov (United States)

    Oryan, B.; Buck, W. R.

    2017-12-01

    The Tohoku-oki earthquake was one of the strongest earthquakes ever recorded. 50-80 meters of lateral motion of the sloping seafloor resulted in a tsunami that exceeded predictions and caused one of the costliest natural disasters in history. It was also the first time extensional aftershocks were observed in the upper plate over a region as wide as 250km. Inspired by these findings, researchers found similar upper plate extensional earthquakes after reexamining seismic data from past earthquakes that had also produced large tsunamis. Such extensional aftershocks are difficult to explain in terms of standard subduction models. Most models assume that the dip of the subducting plate remains constant with time. However, geological evidence indicates that the dip angle of the subducting plate changes. We hypothesize that a reduction in the dip angle of the subducting plate can cause upper plate extensional earthquakes. This change in dip angle adds extensional bending stress to the upper plate. During an inter-seismic period, the interface is `locked' causing regional compression that prevents the release of extensional energy. Relief of compressional stresses during a megathrust event can trigger the release of the accumulated extensional energy, explaining why extensional earthquakes were observed after some megathrust events. Numerical models will be used to test our hypothesis. First, we will model long term subduction with a nearly constant dip angle. Then, we will impose a `mantle wind' to reduce the dip angle of the subducting plate. Eventually, we will model a full seismic cycle of the subduction resulting in a megathrust event. The generation of extensional earthquakes in the upper plate of our model following the megathrust event will allow us to determine whether a causal link exists between these earthquakes and a reduction in the dip angle of the subducting plate.

  15. Tectonic and volcanic history of Rhea as inferred from studies of scarps, ridges, troughs, and other lineaments

    International Nuclear Information System (INIS)

    Thomas, P.G.

    1988-01-01

    The 13 geomorphic feature types presently defined through the analysis of landforms on Rhea are with only one exception interpretable as of tectonic or volcanic-tectonic origin. The troughs, grabens, grooves, pit chains, scarps, and other lineaments are purely extensional in nature, while the ridges are volcanic features formed in an extensional stress field; this extension was followed by a global compression era generating megaridges and megascarps. The extensional landforms seem to form a global grid pattern that is directionally similar to the theoretically projected pattern of a tidally distorted planet. 17 references

  16. 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.

  17. Large deformation properties of short doughs: Effect of sucrose in relation to mixing time

    NARCIS (Netherlands)

    Baltsavias, A.; Jurgens, A.; Vliet, T. van

    1999-01-01

    Large deformation rheological properties of short doughs of various composition prepared under various mixing times were determined in uniaxial compression. Sucrose-syrup doughs exhibited prominent yielding and flow behaviour. Their apparent biaxial extensional viscosity decreased with increasing

  18. Mechanical controls on collision related compressional intraplate deformation.

    NARCIS (Netherlands)

    Ziegler, P.A.; van Wees, J.D.A.M.; Cloetingh, S.A.P.L.

    1998-01-01

    Intraplate compressional features, such as inverted extensional basins, upthrust basement blocks and whole lithospheric folds, play an important role in the structural framework of many cratons. Although compressional intraplate deformation can occur in a number of dynamic settings, stresses related

  19. 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...

  20. 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...

  1. 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.

  2. Preliminary results of a geophysical study of the East Greenland Caledonides

    DEFF Research Database (Denmark)

    Schiffer, Christian; Jacobsen, B. H.; Balling, N.

    The present-day topography and crustal structure of the East Greenland Caledonides were intensively influenced by several constructive and destructive processes, including the Caledonian orogeny, the subsequent extensional collapse, continental breakup and fluvial and glacial erosional processes....

  3. Evaluation of Thermally Induced Degradation of Branched Polypropylene by Using Rheology and Different Constitutive Equations

    OpenAIRE

    Jiri Drabek; Martin Zatloukal

    2016-01-01

    In this work, virgin as well as thermally degraded branched polypropylenes were investigated by using rotational and Sentmanat extensional rheometers, gel permeation chromatography and different constitutive equations. Based on the obtained experimental data and theoretical analysis, it has been found that even if both chain scission and branching takes place during thermal degradation of the tested polypropylene, the melt strength (quantified via the level of extensional strain hardening) ca...

  4. Native and exotic oysters in Brazil: Comparative tolerance to hypercapnia.

    Science.gov (United States)

    Moreira, Anthony; Figueira, Etelvina; Pecora, Iracy L; Soares, Amadeu M V M; Freitas, Rosa

    2018-02-01

    Environmental hypercapnia in shallow coastal marine ecosystems can be exacerbated by increasing levels of atmospheric CO 2 . In these ecosystems organisms are expected to become increasingly subjected to pCO 2 levels several times higher than those inhabiting ocean waters (e.g.: 10,000µatm), but still our current understanding on different species capacity to respond to such levels of hypercapnia is limited. Oysters are among the most important foundation species inhabiting these coastal ecosystems, although natural oyster banks are increasingly threatened worldwide. In the present study we studied the effects of hypercapnia on two important oyster species, the pacific oyster C. gigas and the mangrove oyster C. brasiliana, to bring new insights on different species response mechanisms towards three hypercapnic levels (ca. 1,000; 4,000; 10,000 µatm), by study of a set of biomarkers related to metabolic potential (electron transport system - ETS), antioxidant capacity (SOD, CAT, GSH), cellular damage (LPO) and energetic fitness (GLY), in two life stages (juvenile and adult) after 28 days of exposure. Results showed marked differences between each species tolerance capacity to hypercapnia, with contrasting metabolic readjustment strategies (ETS), different antioxidant response capacities (SOD, CAT, GSH), which generally allowed to prevent increased cellular damage (LPO) and energetic impairment (GLY) in both species. Juveniles were more responsive to hypercapnia stress in both congeners, and are likely to be most sensitive to extreme hypercapnia in the environment. Juvenile C. gigas presented more pronounced biochemical alterations at intermediate hypercapnia (4,000µatm) than C. brasiliana. Adult C. gigas showed biochemical alterations mostly in response to high hypercapnia (10,000µatm), while adult C. brasiliana were less responsive to this environmental stressor, despite presenting decreased metabolic potential. Our data bring new insights on the biochemical

  5. CHEMICAL STUDY OF Hortia superba (Rutaceae AND INVESTIGATION OF THE ANTIMYCOBACTERIAL ACTIVITY OF CRUDE EXTRACTS AND CONSTITUENTS ISOLATED FROM Hortia SPECIES

    Directory of Open Access Journals (Sweden)

    Vanessa Gisele Pasqualotto Severino

    2015-01-01

    Full Text Available In this paper, the chemical study of Hortia superba and antimycobacterial potential of Hortia species were investigated. Crude extracts and limonoids, alkaloids, dihydrocinnamic acid derivatives and coumarins isolated from Hortia superba, Hortia oreadica and Hortia brasiliana were evaluated against Mycobacterium tuberculosis H37Rv, Mycobacterium kansasii and Mycobacterium avium. The results obtained demonstrated an inhibitory effect of the dichloromethane extract of leaves of H. oreadica (MIC 31.25 µg mL-1, indolequinazoline (15.62 µg mL-1 and furoquinoline (31.25 µg mL-1 alkaloids, and dihydrocinnamic acid derivatives (62.50 µg mL-1, on the growth of M. tuberculosis. These results are promising in relation to the search for biologically active natural products and could be useful in the development of effective new drugs against mycobacteria.

  6. Resenha do livro: 'Catálogo dos folhetos da Coleção Barbosa Machado. Anais da Biblioteca Nacional'

    Directory of Open Access Journals (Sweden)

    Erasmo D'Almeida Magalhães

    1977-03-01

    Full Text Available (primeiro parágrafo do texto As investigações e trabalhos levados a cabo por Rosemaire Horch, responsável pela publicação de Sermões impressos dos autos da fé (Rio de Janeiro, 1960 e dos primorosos Catálogos da Brasiliana da Coleção Barbosa Machado (Rio de Janeiro, 1967 e dos Vilancicos da Coleção Barbosa Machado (Rio de Janeiro, 1969, tem revelado a importância da função da bibliotecária que não se atem tão somente a problemas de ordem técnica secundária, mas antes, torna a biblioteca um organismo vivo e dinâmico.

  7. 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.

  8. Equinodermes do Brasil: IV. Sobre seis espécies novas de Ophiuroidea da região ao largo da Ilha Grande (RJ

    Directory of Open Access Journals (Sweden)

    Luiz Roberto Tommasi

    1974-01-01

    Full Text Available Este trabalho apresenta a descrição, distribuição, dados ecológicos, chaves para classificação e fotografias de seis espécies novas de Ophiuroidea pertencentes às famílias Ophiolepididae, Amphiuridae, Ophiacanthidae , Ophiomyxidae e Amphilepididae (Echinodermata: Ophiuroidea. Os animais foram coletados das dragagens efetuadas pelo N/Oc. "Prof. W. Besnard" ao largo da Ilha Grande (RJ em fevereiro e julho de 1969. Os gêneros Ophiornastus, Ophioleptoplax e Amphilepis são registrados pela primeira vez no Atlântico Sul Ocidental.Description, distribution and ecological observations are presented for the following six new Ophiuroidea species: Ophiomastus satelitae sp. n., Ophiomusium anaelisae sp. n., Amphioplus mathildae sp. n., Ophiaoantha brasiliensis sp. n., Ophioleptoplax brasiliana sp. n. and Amphilepis teodorae sp. n.. The species were collected in front of Ilha Grande (RJ, from 50-500 m depth.

  9. A new species of Atanatolica Mosely 1936 (Trichoptera: Leptoceridae) from Serra Bonita, Bahia, Brazil.

    Science.gov (United States)

    Costa, Anne M; Calor, Adolfo R

    2014-04-16

    The Neotropical genus Atanatolica includes 17 species distributed from Costa Rica to Brazil, but only two, A. brasiliana and A. flinti, have been recorded from Brazil, both occurring in Rio de Janeiro and São Paulo States. A new species, Atanatolica bonita n. sp., is described and illustrated based on males and females from the Atlantic Forest in Bahia State in northeastern Brazil. The new species can be diagnosed by the following characters: Apicomesal and apicolateral processes of segment X of same length, long and digitate; and second article of each inferior appendage well developed, long, and thumb-shaped. Notes on demographic changes and correlations with seasonal variation and precipitation are also given.

  10. Survival of Saplings in Recovery of Riparian Vegetation of Pandeiros River (MG

    Directory of Open Access Journals (Sweden)

    Nathalle Cristine Alencar Fagundes

    2018-02-01

    Full Text Available ABSTRACT This study monitored the survival of saplings planted according to different recovery models in a riparian forest of the Pandeiros river (Januária, MG. The models consisted of planting the saplings in lines of 2 or 4 m with presence (T2S and T4S, respectively or absence of direct seeding (T2 and T4, respectively. We planted 16,259 saplings of 17 botanical families, 32 genera and 33 species. The saplings, in general, presented a survival rate after one year of 34.4% (±1.8. The species with highest survival rates were Jacaranda brasiliana, with 85.0% (±13.5 of survival, Anadenanthera colubrina, with 70.1% (±7.0, and Triplaris gardneriana, with 69.3% (±9.1. Survival did not vary between the models tested, probably due to the short evaluation period (12 months.

  11. Determinação de atividade antimicrobiana de extratos de plantas de uso popular como antiflamatório

    Directory of Open Access Journals (Sweden)

    N. Caetano

    Full Text Available Antimicrobial activities of “babaçu” (Orbignya martiana, “cardo santo” (Argemone mexicana, “mentrasto” (Ageratum conyzoides, “cavalinha” (Equisetum yeamalis and “terramicina” (Alternanthera brasiliana, used by Brazilian population as antiinflamatory medicine, were studied on Staphylococcus aureus. The freezer dried hydroalcoholic extracts solutions were tested for 7 strains of Staphylococcus aureus, which two of those are methicillin resistant (MRSA. The diffusion method on agar-agar, using holes technique, with tetracycline chlorydrate as standard. “Babaçu”, “cardo santo” and “terramicina” showed antimicrobial activity, within of those “terramicina” inhibited 6 strains, presenting zone inhibition of 22 mm compared to standard antibiotic (34 mm, except the seventh strain which was also tetracycline resistant.

  12. Biaxial seismic behaviour of reinforced concrete columns =

    Science.gov (United States)

    Rodrigues, Hugo Filipe Pinheiro

    A analise dos efeitos dos sismos mostra que a investigacao em engenharia sismica deve dar especial atencao a avaliacao da vulnerabilidade das construcoes existentes, frequentemente desprovidas de adequada resistencia sismica tal como acontece em edificios de betao armado (BA) de muitas cidades em paises do sul da Europa, entre os quais Portugal. Sendo os pilares elementos estruturais fundamentais na resistencia sismica dos edificios, deve ser dada especial atencao a sua resposta sob acoes ciclicas. Acresce que o sismo e um tipo de acao cujos efeitos nos edificios exige a consideracao de duas componentes horizontais, o que tem exigencias mais severas nos pilares comparativamente a acao unidirecional. Assim, esta tese centra-se na avaliacao da resposta estrutural de pilares de betao armado sujeitos a acoes ciclicas horizontais biaxiais, em tres linhas principais. Em primeiro lugar desenvolveu-se uma campanha de ensaios para o estudo do comportamento ciclico uniaxial e biaxial de pilares de betao armado com esforco axial constante. Para tal foram construidas quatro series de pilares retangulares de betao armado (24 no total) com diferentes caracteristicas geometricas e quantidades de armadura longitudinal, tendo os pilares sido ensaiados para diferentes historias de carga. Os resultados experimentais obtidos sao analisados e discutidos dando particular atencao a evolucao do dano, a degradacao de rigidez e resistencia com o aumento das exigencias de deformacao, a energia dissipada, ao amortecimento viscoso equivalente; por fim e proposto um indice de dano para pilares solicitados biaxialmente. De seguida foram aplicadas diferentes estrategias de modelacao nao-linear para a representacao do comportamento biaxial dos pilares ensaiados, considerando nao-linearidade distribuida ao longo dos elementos ou concentrada nas extremidades dos mesmos. Os resultados obtidos com as varias estrategias de modelacao demonstraram representar adequadamente a resposta em termos das curvas

  13. 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.

  14. 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.

  15. 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.

  16. Capillary Thinning and Pinch-off Dynamics and Printability of Polyelectrolyte Solutions

    Science.gov (United States)

    Sharma, Vivek; Jimenez, Leidy N.; Dinic, Jelena; Parsi, Nikila

    Biological macromolecules like proteins, DNA and polysaccharides, and many industrial polymers, are classified together as polyelectrolytes for in solution, the repeat units in their backbone are decorated with disassociated, charge-bearing ionic groups, surrounded by counter-ions. In diverse applications like inkjet printing, sprayable cosmetics and insecticides, paints and coatings that involve formation of fluid columns or sheets that undergo progressive thinning and pinch-off into drops, the dominant flow within the necking filament is extensional in nature. The extensional rheology response of the charged macromolecular solutions is not as well understood as that of their uncharged counterparts. Here focus on the characterization of capillary thinning and pinch-off dynamics, extensional rheology and printability of two model systems: sodium (polystyrene sulfonate) and poly(acrylic acid) by using dripping-onto-substrate (DoS) rheometry technique. Both the measured extensional relaxation times and the extensional viscosity values show salt- and polymer concentration-dependent behavior that is not expected or anticipated from the typical shear rheology response.

  17. Molecular Rheology of Complex Fluids

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik Koblitz

    The processing of polymer materials is highly governed by its rheology, and influences the properties of the final product. For example, a recurring problem is instability in extrusion that leads to imperfect plastic parts. The ability to predict and control the rheological behavior of polymer...... flow is the dominant type of deformation. The polymer molecules experience a significant amount of chain orientation and stretching during these processes. Shear rheology measured by conventional shear rheometers is good at describing chain orientation, whereas extensional rheology gives a good way...... of inducing chain stretching. Accurate and reliable stress–strain measurements of extensional flow play a crucial role in the understanding of non–linear rheological properties of polymers. However, the non–linear extensional rheology has not been extensively studied. It is known that the rheology of polymer...

  18. 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...

  19. Normal-faulting stress state associated with low differential stress in an overriding plate in northeast Japan prior to the 2011 Mw 9.0 Tohoku earthquake

    Science.gov (United States)

    Otsubo, Makoto; Miyakawa, Ayumu; Imanishi, Kazutoshi

    2018-03-01

    Spatial and temporal variations in inland crustal stress prior to the 2011 Mw 9.0 Tohoku earthquake are investigated using focal mechanism solutions for shallow seismicity in Iwaki City, Japan. The multiple inverse method of stress tensor inversion detected two normal-faulting stress states that dominate in different regions. The stress field around Iwaki City changed from a NNW-SSE-trending triaxial extensional stress (stress regime A) to a NW-SE-trending axial tension (stress regime B) between 2005 and 2008. These stress changes may be the result of accumulated extensional stress associated with co- and post-seismic deformation due to the M7 class earthquakes. In this study we suggest that the stress state around Iwaki City prior to the 2011 Tohoku earthquake may have been extensional with a low differential stress. High pore pressure is required to cause earthquakes under such small differential stresses.

  20. Microelectromechanical resonator and method for fabrication

    Science.gov (United States)

    Wittwer, Jonathan W [Albuquerque, NM; Olsson, Roy H [Albuquerque, NM

    2009-11-10

    A method is disclosed for the robust fabrication of a microelectromechanical (MEM) resonator. In this method, a pattern of holes is formed in the resonator mass with the position, size and number of holes in the pattern being optimized to minimize an uncertainty .DELTA.f in the resonant frequency f.sub.0 of the MEM resonator due to manufacturing process variations (e.g. edge bias). A number of different types of MEM resonators are disclosed which can be formed using this method, including capacitively transduced Lame, wineglass and extensional resonators, and piezoelectric length-extensional resonators.

  1. 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

    with a spherical microstructure adopts a body-centred cubic (bcc) structure with a [111] orientation along the Row direction. For the pre-oriented triblock with a cylindrical microstructure, the cylinder axis is aligned along the extensional Row direction. Investigation of the mechanical properties showed......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...

  2. A produção de vôngole e seu potencial para o desenvolvimento de novos produtos a base de pescado

    Directory of Open Access Journals (Sweden)

    Mayla Monique dos Santos Leite

    2015-12-01

    Full Text Available A dificuldade em suprir a demanda de proteína de origem animal de excelente valor biológico para a população humana é uma das maiores preocupações do nosso século. De acordo com a FAO, a atividade pesqueira (pesca extrativa e aquicultura, será uma das principais atividades responsáveis pela segurança alimentar do planeta, com previsões de produção de proteína de origem animal para a próxima década maior do que o setor de animais de abate (carnes bovinas, suínas e aves. A utilização de recursos pesqueiros subutilizados com potencial para explotação poderá assegurar a manutenção da oferta primária de matéria prima no mercado interno local e/ou regional, e inibir oscilação de preços, como a prática da mariscagem. Neste contexto, o presente artigo de revisão tem por objetivo evidenciar o potencial da Anomalocardia brasiliana para explotação e processamento contribuindo para o fortalecimento desta cadeia produtiva no segmento artesanal e diversificação de produtos no mercado brasileiro.The production of clams and its potential for development of new products based on fish Abstract: The difficulty in supplying the animal protein demand of great biological value for the human population is a major concern of our century. According to the FAO, the fishery (extractive fishing and aquaculture, will be one of the main activities responsible for food safety in the world, with animal protein production forecasts for the next decade longer than the slaughter of animals sector (beef, pork and poultry. The use of fishing resources with underutilized potential for exploitation can ensure the maintenance of primary supply of raw materials on-site domestic and / or regional, and inhibit movement of prices, as the practice of shellfish. In this context, the present review aims to highlight the potential of Anomalocardia brasiliana to exploitation and processing contributing to the strengthening of this production chain in the

  3. COMPOSIÇÃO CENTESIMAL E DE MINERAIS DE MARISCOS CRUS E COZIDOS DA CIDADE DE NATAL/RN CENTESIMAL AND MINERAL COMPOSITION OF THE RAW AND COOKED SHELLFISHES OF THE NATAL-RN CITY

    Directory of Open Access Journals (Sweden)

    Lucia de Fátima Campos PEDROSA

    2001-08-01

    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.The aim of this study was to analyse the centesimal composition as well as zinc, copper and iron contents of the five species from raw and cooked shellfishes: shrimp (Penaeus brasiliensis, crab (Ucides cordatus, lobster (Panulirus argus, oyster (Crassostrea rhizophorae and mussel (Anomalocardia brasiliana. The edible samples were collected in the fish market of the Natal city. Shellfishes were considered an expressive source of the proteins and minerals, while quantities of lipids and calories were low. After the cooking process protein and ash concentration increased in most of shellfishes. Zinc analysis showed variable concentration in the species. Oyster was the food with the highest zinc values. Mussel was considered the best source of iron and copper but around 50% of the copper detected was

  4. 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

  5. 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 ...

  6. Analysis of rosen piezoelectric transformers with a varying cross-section.

    Science.gov (United States)

    Xue, H; Yang, J; Hu, Y

    2008-07-01

    We study the effects of a varying cross-section on the performance of Rosen piezoelectric transformers operating with length extensional modes of rods. A theoretical analysis is performed using an extended version of a one-dimensional model developed in a previous paper. Numerical results based on the theoretical analysis are presented.

  7. 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…

  8. Tectonic and climatic controls on asymmetric half-graben sedimentation : Inferences from 3-D numerical modeling

    NARCIS (Netherlands)

    Balázs, Attila; Granjeon, Didier; Matenco, Liviu; Sztanó, Orsolya; Cloetingh, Sierd

    2017-01-01

    The tectono-sedimentary evolution of asymmetric extensional systems driven by the activity of major normal faults or detachments associated with footwall exhumation is often characterized by a sequence of slower, faster, and ultimately again slower subsidence rates in the center of hanging wall

  9. The linking of the upper-middle and lower reaches of the Yellow River as a result of fluvial entrenchment

    NARCIS (Netherlands)

    Hu, Zhenbo; Pan, Bao Tian; Bridgland, David; Vandenberghe, Jef; Guo, Lian Yong; Fan, Yun Long; Westaway, Rob

    2017-01-01

    The upper–middle Yellow River flows through the Fenwei graben, a structure resulting from extensional tectonism that was formed and repeatedly extended during the Cenozoic. The drainage system within this graben was formerly isolated from the lower reaches of the Yellow River system by the Xiaoshan

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

    Indian Academy of Sciences (India)

    extension determined based on geodetically computed extension rate and age of initiation of rifting in southern ..... sive distribution of these extensional structures in the Lesser Himalayas, we analysed incised fluvial terrace deposits. In the eastern Himalaya, the MCT ..... and Duncan C 2006 Climatic forcing of erosion, land-.

  11. Integrated high-resolution stratigraphy : Relative contributions of tectonics, eustasy and climate on basin evolution (Vienna Basin, Austria)

    NARCIS (Netherlands)

    Paulissen, W.E.

    2011-01-01

    Sedimentary basins form in a range of large-scale tectonic settings involving extensional, compressional or lateral movements. The dynamics of the basin infill are controlled by driving mechanisms such as tectonics, climate and eustatic control. The created accommodation space in the basin is filled

  12. A Middle-Upper Miocene fluvial-lacustrine rift sequence in the Song Ba Rift, Vietnam

    DEFF Research Database (Denmark)

    Lars H., Nielsen; Henrik I., Petersen; Nguyen D., Dau

    2007-01-01

    The small Neogene Krong Pa graben is situated within the continental Song Ba Rift, which is bounded by strike-slip faults that were reactivated as extensional faults in Middle Miocene time. The 500 m thick graben-fill shows an overall depositional development reflecting the structural evolution, ...

  13. Kinematic and thermal evolution of the Moroccan rifted continental margin: Doukkala-High Atlas Transect

    NARCIS (Netherlands)

    Gouiza, M.; Bertotti, G.V.; Hafid, M.; Cloetingh, S.A.P.L.

    2010-01-01

    The Atlantic passive margin of Morocco developed during Mesozoic times in association with the opening of the Central Atlantic and the Alpine Tethys. Extensional basins formed along the future continental margin and in the Atlas rift system. In Alpine times, this system was inverted to form the High

  14. Policy administration in tag-based authorization

    NARCIS (Netherlands)

    Etalle, Sandro; Hinrichs, Timothy L.; Lee, Adam J.; Trivellato, Daniel; Zannone, Nicola

    2013-01-01

    Tag-Based Authorization (TBA) is a hybrid access control model that combines the ease of use of extensional access control models with the expressivity of logic-based formalisms. The main limitation of TBA is that it lacks support for policy administration. More precisely, it does not allow

  15. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    ... by extensional mechanism of Gondwana tectonics events. Similar widespread granitic activity has also beendocumented in the Arabian Nubian shield, Madagascar, Sri Lanka and Antarctica, providing similarities for the reconstruction of the crustal fragments of Gondwana supercontinent followed by Pan-African orogeny.

  16. 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

  17. Kinematics of large scale asymmetric folds and associated smaller ...

    Indian Academy of Sciences (India)

    metric half grabens which acted as repository for the Proterozoic sequences adjoining the Bastar craton. Reactivation of extensional stage normal faults and moulding of folds ...... opment at shallow crustal level in the intra-cratonic. Proterozoic belt near Godavari–Indravati confluence, S. India. Unpublished Ph.D. thesis.

  18. IS-A diversified

    DEFF Research Database (Denmark)

    Nilsson, Jørgen Fischer

    2014-01-01

    We reconsider the nature and formal properties of the class inclusion relation, IS-A, from the point of view of information modeling and engineering of formal ontologies. In particular we review approaches to the elusive notion of intensionality. We then conduct an analysis adopting a metalogic...... the extensionality/intensionality dichotomy in ontological engineering....

  19. 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 b...

  20. 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 ...

  1. 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.

  2. 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.

  3. Continental Scientific Drilling Program.

    Science.gov (United States)

    1979-01-01

    anomalies ar more complex and controversial. Thin- ning of the lithosphere in regions of extensional tectonics implies mechanical A:h ofmam, fena les tha...porphyry-copper districts (i.e., a volcanic setting, locally strong sericitic and argillic alteration, and the occur- rence of breccia pipes and

  4. Tectonic evolution of Tarim basin in Cambrian–Ordovician and its ...

    Indian Academy of Sciences (India)

    For different geodynamic settings of surrounding regions, there are different charac- teristics of depositional lithologies and lithofacies, sea-level change, distribution and migration of sed- imentary facies, etc., in the Tarim basin. Under the condition of regional extensional dynamic setting around Tarim Plate, there formed the ...

  5. 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...

  6. Structural evidence for strike-slip deformation in the Izmir-Balikesir transfer zone and consequences for late Cenozoic evolution of western Anatolia (Turkey)

    NARCIS (Netherlands)

    Uzel, B.; Sözbilir, H.; Özkaymak, T.; Kaymakci, N.; Langereis, C.G.

    2013-01-01

    The Izmir-Balikesir transfer zone (IBTZ) is a recently recognized strike-slip dominated shear zone that accommodates the differential deformation between the Cycladic and Menderes core complexes within the Aegean Extensional System. Here, we present new structural and kinematic data obtained from

  7. Application of geophysics in the aerial mapping of magmatic complexes of the Sierra de Famatina in La Rioja, Argentina

    International Nuclear Information System (INIS)

    Candiani, J.

    2010-01-01

    The mountain range of Famatina is characterized by a group of prominent elevations above the base level of the surrounding area. Geologically it is a complex region that is located in the Andean fore land. Carboniferous extensional tectonics favored per alkaline leucocranitos intrusion. In an area of extreme geo morphological features, the magnetometry and radiometry r methodology has facilitated regional mapping of magmatic units

  8. Effects of Electron Beam Loading on an Operating Piezoelectric Transformer

    Science.gov (United States)

    2013-06-01

    Abstract Piezoelectric transformers (PTs) are currently being used to accelerate charged-particle beams for various applications [1, 2]. Beam...to maximize the transformer ratio of length-extensional piezoelectric transformers , these studies have typically been performed for discrete...Piezoelectric transformers (PTs) are currently being used to accelerate charged-particle beams for various applications [1, 2]. Beam interactions at the output

  9. Sadhana | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Numerical simulation of breakup and detachment of an axially stretching Newtonian liquid bridge with a moving contact line phase field method · KISHORE SINGH PATEL RATNESH K SHUKLA · More Details Abstract Fulltext PDF. The extensional, breakup and detachment dynamics of an axially stretching Newtonian liquid ...

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

    Indian Academy of Sciences (India)

    Kishore Singh Patel

    Abstract. 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 mul- tiphase flow solver employs a Cahn–Hilliard phase field model to describe the evolution of the diffuse interface.

  11. 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.

  12. Quotient maps: frame-valued spaces | Boustique | Quaestiones ...

    African Journals Online (AJOL)

    It is known that the category of frame-valued convergence spaces is topological, cartesian-closed and extensional. Properties of quotient maps between objects in this category are investigated here; in particular, it is shown that quotient maps are productive under arbitrary products. Keywords: L-filter, frame-valued ...

  13. Magnetostratigraphy of the Xiaolongtan Formation bearing Lufengpithecus keiyuanensis in Yunnan, southwestern China : Constraint on the initiation time of the southern segment of the Xianshuihe–Xiaojiang fault

    NARCIS (Netherlands)

    Li, S.; Deng, Chenglong; Dong, Wei; Sun, Lu; Liu, S.; Qin, Huafeng; Yin, Jiyun; Ji, Xueping; Zhu, Rixiang

    2015-01-01

    The late Cenozoic extensional basins in Yunnan Province (southwestern China), which are kinematically linked with the regional strike-slip faults, can provide meaningful constraints on the fault activity history and tectonic evolution of the southeast margin of the Tibetan Plateau (SEMTP), and

  14. 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…

  15. 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.

  16. 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...

  17. An Executable Formalization of the HOL/Nuprl Connection in the Metalogical Framework

    DEFF Research Database (Denmark)

    Schürmann, Carsten; Stehr, Mark-Oliver

    2006-01-01

    Howe’s HOL/Nuprl connection is an interesting example of a translation between two fundamentally different logics, namely a typed higher-order logic and a polymorphic extensional type theory. In earlier work we have established a proof-theoretic correctness result of the translation in a way...

  18. The optimization of Blister Disk geometry for mixing performance in co-rotating twin-screw extruder

    Science.gov (United States)

    Matsumoto, Koki; Kayamori, Natsuki; Tanaka, Tatsuya; Arao, Yoshihiko

    2015-05-01

    Extensional flow has been taken notice as the more efficient solution for improving the dispersion of nanocomposites than shear flow. One of the production processes of nanocomposites is melt extrusion with co-rotating twin-screw extruder (TSE) which is superior in terms of productivity and mixing performance. Then, we focused on "Blister Disk" which had many small holes for generating the extensional flow. However, the influences on the mixing performance by changing the geometry of Blister Disk have not been investigated as far as we know. Therefore, the objective of this study is the optimization of Blister Disk geometry (e.g. hole numbers, hole diameter and disk length) for improving the dispersion of nanocomposites. Primary, the extensional flow state was investigated at the Blister Disk with FEM analysis. Secondly, to validate the simulation results experimentally, the polypropylene reinforced multi-walled carbon nanotube (PP/CNT nanocomposite) was used as the model of nanocomposite, and the dispersion state of CNT was investigated by morphological observation. As the result of these experiments, the better dispersion state of CNT was obtained as total permeation area and shorter hole length of Blister Disk was smaller because extensional and shear stress were increased.

  19. Paleomagnetic evidence for an inverse rotation history of Western Anatolia during the exhumation of Menderes core complex

    NARCIS (Netherlands)

    Uzel, Bora; Langereis, Cornelis G.; Kaymakçı, Nuretdin; Sözbilir, Hasan; Özkaymak, Çağlar; Özkaptan, Murat

    2015-01-01

    Within the Aegean extensional system, the Izmir-Balikesir Transfer Zone (IBTZ) is a crucial element in the late Cenozoic evolution of western Anatolia since it accommodates the differential deformation between the Cycladic and the Menderes metamorphic core complexes. Here, we determine the

  20. 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

  1. Genesis of iron-apatite ores in Posht-e-Badam Block (Central Iran ...

    Indian Academy of Sciences (India)

    Iran iron-apatite ores are clearly related to an extensional setting where rifting was important (SSE–NNW fault lines). A probable ... and McLennan 1985). Of crucial importance is the ..... at the Esfordi deposit, (c) the Zarigan phosphate deposit and (d) fine to coarse-grained euhedral apatite crystals within the magnetite at the ...

  2. 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

  3. Early Neoarchaean A-type granitic magmatism by crustal reworking ...

    Indian Academy of Sciences (India)

    29

    dyke swarm). It is suggested that the ~2.8 Ga A-type granites in the Singbhum craton mark a significant crustal reworking event attendant to mantle-derived mafic magmatism in an extensional tectonic setting. Key words: Granite; A-type; Geochemistry; Archaean; Crustal reworking; Singhbhum craton. Abstract. Click here to ...

  4. On Structural Completeness of Tabular Superintuitionistic Logics

    NARCIS (Netherlands)

    Citkin, Alexander

    2015-01-01

    As usual, the superintuitionistic (propositional) logics (that is, logics extending intuitionistic logic) are being studied “modulo derivability”, meaning such logics are viewed extensionally — they are identified with the set of formulae that are valid (derivable in the corresponding calculus) in

  5. Effect of second to first normal stress difference ratio at the die exit on neck-in phenomenon in polymeric flat film production

    Science.gov (United States)

    Barborik, Tomas; Zatloukal, Martin

    2017-05-01

    In this study, viscoelastic modeling of the extrusion film casting process, based on the lD membrane model and modified Leonov constitutive equation, was conducted and the effect of the viscoelastic stress state at the die exit (captured here via second to first normal stress difference ratio) on the unwanted neck-in phenomenon has been analyzed for wide range of Deborah numbers and materials having different level of uniaxial and planar extensional strain hardening. Relevant experimental data for LDPE and theoretical predictions based on multimode eXtended Pom-Pom model acquired from the open literature were used for the validation purposes. It was found that firstly, the predicting capabilities of both constitutive equations for given material and processing conditions are comparable even if the single mode modified Leonov model was used and secondly, the agreement between theoretical and experimental data on neck-in is fairly good. Results of the theoretical study revealed that the viscoelastic stress state at the die exit (i.e. -N2/N1 ratio) increases the level of neck-in if uniaxial extensional strain hardening, planar to uniaxial extensional viscosity ratio and Deborah number increases. It has also been revealed that there exists threshold value for Deborah number and extensional strain hardening below which the neck-in becomes independent on the die exit stress state.

  6. Tensional fissures in sediments as signature of rift tectonics in the ...

    African Journals Online (AJOL)

    Earlier studies have shown that the effects of this extension are manifested mainly through earthquakes, faults and volcanism. Recently, with the observations of the occurrence of fissures of tectonic origin on the sediment cover of the rift floor, an additional effect of the extensional process has been identified. The importance ...

  7. Stress relaxation and reversed flow of low-density polyethylene melts following uniaxial extension

    DEFF Research Database (Denmark)

    Huang, Qian; Rasmussen, Henrik K.; Skov, Anne Ladegaard

    2012-01-01

    The extensional dynamics of two low-density polyethylene melts Lupolen 3020D and Lupolen 1840D, both showing a stress overshoot in start-up of uniaxial extension [Rasmussen, H. K., J. K. Nielsen, A. Bach, and O.Hassager, 'Viscosity overshoot in the start-up of uniaxial elongation of low density p...

  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. 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

  10. Linear viscoelastic characterization from filament stretching rheometry

    DEFF Research Database (Denmark)

    Wingstrand, Sara Lindeblad; Alvarez, Nicolas J.; Hassager, Ole

    Traditionally, linear viscoelasticity is measured using small amplitude oscillatory shear flow. Due to experimental difficulties, shear flows are predominately confined to the linear and mildly nonlinear regime. On the other hand, extensional flows have proven more practical in measuring viscoela......Traditionally, linear viscoelasticity is measured using small amplitude oscillatory shear flow. Due to experimental difficulties, shear flows are predominately confined to the linear and mildly nonlinear regime. On the other hand, extensional flows have proven more practical in measuring...... 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...... to measure both linear and nonlinear dynamics on a single apparatus. With a software modification to the FSR motor control, we show that linear viscoelasticity can be measured via small amplitude squeeze flow (SASF). Squeeze flow is a combination of both shear and extensional flow applied by axially...

  11. Are Risk Assessments of a Terrorist Attack Coherent?

    Science.gov (United States)

    Mandel, David R.

    2005-01-01

    Four experiments examined 3 types of violations of coherence criteria in risk assessments of a terrorist attack. First, the requirement that extensionally equivalent descriptions be assigned the same probability (i.e., additivity) was violated. Unpacking descriptions of an attack into subtypes led to an increase in assessed risk. Second,…

  12. Journal of Earth System Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    However, disposition of the basins and their structural architecture indicate that the kinematics of all the basins cannot be extensional. To maintain kinematic compatibility with other basins as well as the bulk lateral extension, some basins ought to be of strike-slip origin. The disposition, shape and structural architecture of ...

  13. Palaeoseismicity in relation to basin tectonics as revealed from soft ...

    Indian Academy of Sciences (India)

    an extensional tectonic setting (Gibbs 1984), which led to a half-graben geometry with accumulation of greater thickness of sediment towards the south. (Ghosh 2002). Transverse normal faults, regarded as transfer faults (Gibbs 1984), are distributed along the basin margin and have affected the con- tact of the Gondwana ...

  14. On the evolution of the Kazaure Schist Belt of NW Nigeria: a re ...

    African Journals Online (AJOL)

    Taking into account the presence of Banded Iron Formations (BIFs), metavolcanics and the Kalangai-Zungeru-Ifewara (KZI) fault in the belt, a new model of its evolution is proposed. The new model of evolution of the KZSB considers the evolution of the belt by invoking a simple ensialic mechanism under extensional and ...

  15. Resolution of non-double-couple components in the seismic moment tensor using regional networks-II: application to aftershocks of the 1999 M-w 7.4 Izmit earthquake

    Czech Academy of Sciences Publication Activity Database

    Stierle, E.; Bohnhoff, M.; Vavryčuk, Václav

    2014-01-01

    Roč. 196, č. 3 (2014), s. 1878-1888 ISSN 0956-540X R&D Projects: GA ČR(CZ) GAP210/12/1491 Institutional support: RVO:67985530 Keywords : earthquake source observations * seismicity and tectonics * continental tectonics: extensional Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 2.724, year: 2013

  16. Predicting pore pressure in active fold-thrust systems: An empirical model for the deepwater Sabah foldbelt

    Science.gov (United States)

    Couzens-Schultz, Brent A.; Azbel, Konstantin

    2014-12-01

    Measurements related to mudrock (shale and siltstone) porosity such as acoustic velocity, density or electrical resistivity, have traditionally been used to predict pore pressures in extensional stress settings. The underlying assumption is that burial and vertical effective stress (VES), which is the overburden minus the pore pressure, controls the compaction of these rocks through porosity loss. The dataset presented here compares VES and acoustic velocity of similar composition mudrocks in both an extensional and a compressional stress setting. In the extensional stress environment, the mudrocks follow a typical compaction trend with a porosity loss and increase in acoustic velocity that can be related to VES. In an active fold-thrust belt, the compressive stresses further reduce the porosity and increase the acoustic velocity of the mudrocks. First a layer-parallel shortening compacts sediments beyond what is observed for the VES. This additional compaction is further enhanced near thrust faults and in anticlinal forelimbs, presumably due to additional shear stress in these areas. The mudrocks located in folds that are buried by additional sedimentation do not compact again until the tectonic compaction is overridden by enough new burial. After that, the mudrocks follow the observed extensional setting compaction trend. In the fold-thrust belt, the observed reduction in porosity by stresses other than burial leads to an under-prediction of pore pressure using traditional methods. To account for this, we present a correction that can be applied to the acoustic velocity (or porosity) using two parameters: (a) proximity to thrust faults and anticlinal forelimbs and (b) the amount of burial after fold formation. With these corrections, the extensional velocity-VES compaction trend can be used to accurately predict pore pressure within the active fold-thrust belt. The correction is calibrated with well data and is empirical. None-the-less, it is a first step toward

  17. Rotation, narrowing and preferential reactivation of brittle structures during oblique rifting

    Science.gov (United States)

    Huismans, R. S.; Duclaux, G.; May, D.

    2017-12-01

    Occurrence of multiple faults populations with contrasting orientations in oblique continental rifts and passive margins has long sparked debate about relative timing of deformation events and tectonic interpretations. Here, we use high-resolution three-dimensional thermo-mechanical numerical modeling to characterize the evolution of the structural style associated with moderately oblique rifting in the continental lithosphere. Automatic analysis of the distribution of active extensional shears at the surface of the model demonstrates a characteristic deformation sequence. We show that upon localization, Phase 1 wide oblique en-échelon grabens develop, limited by extensional shears oriented orthogonal to σ3. Subsequent widening of the grabens is accompanied by a progressive rotation of the Phase 1 extensional shears that become sub-orthogonal the plate motion direction. Phase 2 is marked by narrowing of active deformation resulting from thinning of the continental lithosphere and development of a second-generation of extensional shears. During Phase 2 deformation localizes both on plate motion direction-orthogonal structures that reactivate rotated Phase 1 shears, and on new oblique structures orthogonal to σ3. Finally, Phase 3 consists in the oblique rupture of the continental lithosphere and produces an oceanic domain where oblique ridge segments are linked with highly oblique accommodation zones. We conclude that while new structures form normal to σ3 in an oblique rift, progressive rotation and long-term reactivation of Phase 1 structures promotes orthorhombic fault systems, critical to accommodate upper crustal extension and control oblique passive margin architecture. The distribution, orientation, and evolution of frictional-plastic structures observed in our models is remarkably similar to documented fault populations in the Gulf of Aden conjugate passive margins, which developed in moderately oblique extensional settings.

  18. Preliminary results of mercury levels in raw and cooked seafood and their public health impact.

    Science.gov (United States)

    Costa, Fernanda do N; Korn, Maria Graças A; Brito, Geysa B; Ferlin, Stacy; Fostier, Anne H

    2016-02-01

    Mercury is toxic for human health and one of the main routes of exposure is through consumption of contaminated fish and shellfish. The objective of this work was to assess the possible mercury contamination of bivalves (Anomalocardia brasiliana, Lucina pectinata, Callinectes sapidus), crustacean (C. sapidus) and fish (Bagre marinus and Diapterus rhombeus) collected on Salinas da Margarida, BA (Brazil), a region which carciniculture, fishing and shellfish extraction are the most important economic activities. The effect of cooking on Hg concentration in the samples was also studied. The results showed that Hg concentration was generally higher in the cooked samples than in raw samples. This increase can be related to the effect of Hg pre-concentration, formation of complexes involving mercury species and sulfhydryl groups present in tissues and/or loss of water and fat. The highest concentrations were found in B. marinus samples ranging 837.0-1585.3 μg kg(-1), which exceeded those recommended by Brazilian Health Surveillance Agency (ANVISA). In addition, Hg values found in the other samples also suggest the monitoring of the Hg concentrations in seafood consumed from the region. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. 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.

  20. Persistência de plantas medicinais em sistemas agroflorestais no município de São Bento do Sul, SC, Brasil

    Directory of Open Access Journals (Sweden)

    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.

  1. Bitter plants used as substitute of Cinchona spp. (quina) in Brazilian traditional medicine.

    Science.gov (United States)

    Cosenza, Gustavo P; Somavilla, Nádia S; Fagg, Christopher W; Brandão, Maria G L

    2013-10-07

    Bitter tasting plant species are used as tonics and have been previously used to treat intermittent fevers in Brazil, the principal symptom of malaria. Many of these species were named quina and were used as substitutes of Cinchona spp., the source of quinine. To present data on these bitter species named quina and to discuss their potential as sources of bioactive substances. Data about the plants were obtained from a survey of the literature and documents written by early naturalists and clinical doctors living in the 18th and 19th centuries in Brazil. Correlated pharmacological studies were obtained from different scientific databases. A total of 29 species were recorded. The largest number of species belonged to the Rubiaceae family (14), being Remijia ferruginea (A. St.-Hil) DC. the most representative. Strychnos pseudoquina A. St.-Hil. (Loganiaceae), Hortia brasiliana Vand. ex DC. (Rutaceae) and Solanum pseudoquina A. St.-Hil. (Solanaceae) were also frequently mentioned in the historical bibliography. Pharmacological studies have shown the presence of bitter bioactive substances useful to treat digestive disorders and/or with antimalarial activities, in all of the recorded botanic families. This study shows that several bitter species named quina were used in the past as substitute of Cinchona spp. and studying these plants can lead to the development of new products. © 2013 Elsevier Ireland Ltd. All rights reserved.

  2. New limonoids from Hortia oreadica and unexpected coumarin from H. superba using chromatography over cleaning Sephadex with sodium hypochlorite.

    Science.gov (United States)

    Severino, Vanessa G P; de Freitas, Sâmya D L; Braga, Patrícia A C; Forim, Moacir Rossi; das G F da Silva, M Fátima; Fernandes, João B; Vieira, Paulo C; Venâncio, Tiago

    2014-08-12

    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. Monitoring of polycyclic aromatic hydrocarbons in a produced water disposal area in the Potiguar Basin, Brazilian equatorial margin.

    Science.gov (United States)

    Lourenço, Rafael André; de Oliveira, Fábio Francisco; de Souza, João Maximino; Nudi, Adriana Haddad; de Luca Rebello Wagener, Ângela; de Fátima Guadalupe Meniconi, Maria; Francioni, Eleine

    2016-09-01

    The Potiguar Basin has oil and gas production fields offshore and onshore. All treated produced water (PW) from these fields is discharged through submarine outfalls. Although polycyclic aromatic hydrocarbons (PAHs) are minor constituents of PW, their input into the marine ecosystem is environmentally critical due to potential ecological hazards. A 2-year monitoring program was conducted in the vicinity of the outfalls to evaluate PAH bioaccumulation in marine life from PW discharges. The study was performed using transplanted bivalves Crassostrea brasiliana and semipermeable membrane devices (SPMDs) to measure PAH concentrations via bioaccumulation and in seawater. The bioaccumulation of PAH in transplanted bivalves reached up to 1105 ng g(-1) in the vicinity of the monitored outfall. Significantly lower PAH concentrations were found in the reference area in comparison to the studied area around the outfalls. Time-integrated PAH concentrations in seawater ranged from 38 to 0.3 ng L(-1) near the outfalls and from 10 ng L(-1) to not detected in the reference area. Both measurement techniques were found to be effective for determining a gradient of descending PAH concentrations from the outfalls. In addition, this study also evaluated the bioavailability of PAH for local marine biota and provided information about the influence of PW discharges on the water quality of marine ecosystems.

  4. New Limonoids from Hortia oreadica and Unexpected Coumarin from H. superba Using Chromatography over Cleaning Sephadex with Sodium Hypochlorite

    Directory of Open Access Journals (Sweden)

    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.

  5. 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).

  6. Imagens do Brasil

    Directory of Open Access Journals (Sweden)

    Renato Ortiz

    2013-12-01

    Full Text Available "Retratos do Brasil", "interpretação do Brasil", "pensamento brasileiro", "teoria do Brasil", todos esses termos remetem a uma unidade fundamental: um determinado país. Existe uma longa tradição que se dedica à sua compreensão, à sua decodificação; de fato, há inclusive um plêiade de autores que fazem parte deste panteão (Rocha Pita, Varnhagen, Sílvio Romero, Nina Rodrigues, Euclydes da Cunha, Sérgio Buarque de Holanda, Gilberto Freyre, Cai Prado Jr., Darcy Ribeiro, apenas para citar alguns deles. Todo debate sobre identidade nacional pressupõe algumas categorias de análise, sendo nação e cultura duas dentre as mais importantes. O presente artigo pretende abordar qual o sentido deste debate no mundo contemporâneo. Em que medida as transformações ocorridas nas últimas décadas incidem sobre a imagem que temos de nós mesmos, isto é, as representações simbólicas construídas em torno da tradição brasiliana são impactadas por tais eventos? Qual o seu legado intelectual?

  7. Detection of Perkinsus marinus in the oyster Crassostrea rhizophorae in southern Bahia by proteomic analysis

    Directory of Open Access Journals (Sweden)

    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.

  8. Desafios à cogestão: os impactos da Via Expressa Sul sobre o extrativismo na RESEX Marinha do Pirajubaé

    Directory of Open Access Journals (Sweden)

    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.

  9. Plate interactions control middle late Miocene, proto-Gulf and Basin and Range extension in the southern Basin and Range

    Science.gov (United States)

    Henry, Christopher D.; Aranda-Gomez, J. Jorge

    2000-03-01

    Middle-late Miocene (proto-Gulf; ˜12-6 Ma) extension around the Gulf of California (Gulf Extensional Province) is commonly interpreted as resulting from partitioning of oblique Pacific-North American plate motion into strike-slip displacement along the margin and east-northeast extension perpendicular to the margin within the North American plate. We propose that this mechanism also applies to kinematically similar, predominantly east-northeast extension that occurred at the same time throughout the southern Basin and Range province, from southern Arizona and New Mexico to the Trans-Mexican Volcanic Belt. New field and 40Ar/ 39Ar data in Sinaloa and Durango confirm that this episode of extension occurred on the mainland side of the Gulf and in the Basin and Range east of the Sierra Madre Occidental, which is generally considered the eastern margin of the Gulf Extensional Province. Published data indicate the middle-late Miocene episode also occurred across the northern and southern ends of the Sierra Madre where the Gulf Extensional Province connects with the Basin and Range: (1) from central Sonora into southern Arizona and New Mexico, and (2) from Nayarit into central Mexico north of the Trans-Mexican Volcanic Belt. This episode appears to have affected an area that continues to the eastern edge of the Basin and Range province in Texas and San Luis Potosi. Recognition that this episode of extension affected the entire southern Basin and Range resolves the discrepancy between the amount of extension calculated based on plate reconstructions and that based on field data within the Gulf Extensional Province alone. Published plate reconstructions require 160 to 110 km of east-northeast extension between ˜12 and 6 Ma. If taken up solely within the Gulf Extensional Province, this would have generated 66 to 78% extension, which is much greater than observed. Spread across the entire southern Basin and Range it requires only ˜20% total extension, which is more

  10. 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

  11. 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

  12. 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

  13. Is the current stress state in the Central Amazonia caused by surface water loading?

    Science.gov (United States)

    Ibanez, Delano M.; Riccomini, Claudio; Miranda, Fernando P.

    2014-11-01

    We present new fault data for the region of the Manaus, Central Amazonia, Brazil. Field measurements concentrate on the Miocene-Holocene sedimentary deposits exposed on the Amazonas River Basin, in order to investigate the development of this region in this time-interval. Two faulting events are distinguished since the Miocene. The oldest one is related to NW-SE extension during Miocene times and associated with paleoseismicity, while the younger is associated with NE-SW extension direction and seems to persist today. These two deformational events may be thereby considered Neotectonic. Moreover, the second extensional pulse with NE-SW orientation can be explained by the surface hydrological loading, which induces the Central Amazonia flexural subsidence and may promote extensional stresses in the upper crust.

  14. Rheology of Supramolecular Polymers

    DEFF Research Database (Denmark)

    Shabbir, Aamir

    efficient processes or biomedical areas. Design and development of supramolecular polymers using ionic, hydrogen bonding or transition metal complexes with tailored properties requires deep understanding of dynamics both in linear and non-linear deformations. While linear rheology is important to understand...... the dynamics under equilibrium conditions, extensional rheology is relevant during the processing or in the usage of polymers utilizing supramolecular associations for example, acrylic based pressure sensitive adhesives are subjected to extensional deformations during the peeling where strain hardening......) hydrogen bonding polymers, and (b) ionic bonding polymers (hereafter termed as ionomers). We study linear and non-linear rheology fora model system of entangled pure poly(n-butyl acrylate), PnBA, homopolymer andfour poly(acrylic acid), PnBA-PAA, copolymers with varying AA side groups synthesizedvia...

  15. Crosscutting relations and relative ages of ridges and faults in the Tharsis region of Mars

    Science.gov (United States)

    Watters, T. R.; Maxwell, T. A.

    1983-01-01

    The results of a detailed photogeologic analysis and classification of ridge-fault cross-cutting relationships on ridged plains units of the Tharsis region is reported. The problems involved in using the morphology of ridge-fault intersections to determine relative timing of structural events are discussed. The implications of using intersection angles as well as morphology to determine possible age relationships for the tectonic history of the region are presented. It is concluded that the major ridge-forming events in the Tharsis region were roughly coincident with, and possibly prior to, the extensional events that produced the faulting of the Tempe and Mareotis regions, the Coprates and Memnonia regions, and the rifting of the Valles Marineris. The compressional events that formed most of the ridges are restricted in time both by their relationship to regional extensional events and by the age of the units on which they formed.

  16. Die muttekopfgosau (Lechtaler Alpen, Tirol/Österreich): Sedimentologie und Beckenentwicklung

    Science.gov (United States)

    Ortner, H.

    1994-03-01

    In the Eastern Alps compression during orogeny in the Upper Cretaceous caused crustal thickening, isostatic uplift and gravitational adjustment of the unstable orogenic wedge. This process triggered extensional basin formation on the back of the orogen (Gosau Basins). The basin fill of the Muttekopf Gosau Basin is arranged in megacycles, the first one comprising alluvial fan sediments and “Inoceramus marls” of the Lower Gosau Complex (Faupl et al. 1987) of Santonian age. Three other cycles follow (Upper Gosau Complex, Campanian to Maastrichtian), consisting of turbiditic fining upward sequences, that are indicative for extensional tectonics during basin formation, as subsidence events prevent formation of autocyclic coarsening upward sequences and therefore prograding of the turbidite system. Deposition of the 1st and 2nd Megacycle occured below the CCD (Carbonate Compensation Depth). The carbonate rich 3rd Megacycle was deposited probably below the CCD after a period of palaeogeographic reorganisation (uplift?) in the source area.

  17. 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.

  18. 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.

  19. 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.

  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

    . The number of AA side groups (hydrogen-bonding groups) after hydrolysis is determined from NMR measurements. We show that using the theoretical dependency of modulus and reptation time on the packing length, we can account for the changes in linear viscoelasticity due to transformation of nBA side groups...... 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...

  1. Ultrasonic liquid-level detector for varying temperature and pressure environments

    Science.gov (United States)

    Anderson, R.L.; Miller, G.N.

    1981-10-26

    An ultrasonic liquid level detector for use in varying temperature and pressure environments, such as a pressurized water nuclear reactor vessel, is provided. The detector employs ultrasonic extensional and torsional waves launched in a multiplexed alternating sequence into a common sensor. The sensor is a rectangular cross section stainless steel rod which extends into the liquid medium whose level is to be detected. The sensor temperature derived from the extensional wave velocity measurements is used to compensate for the temperature dependence of the torsional wave velocity measurements which are also level dependent. The torsional wave velocity measurements of a multiple reflection sensor then provide a measurement of liquid level over a range of several meters with a small uncertainty over a temperature range of 20 to 250/sup 0/C and pressures up to 15 MPa.

  2. Immiscible blend morphology after shear and elongation

    Science.gov (United States)

    Batch, Gibson L.; Trifkovic, Milana; Hedegaard, Aaron; Macosko, Christopher W.

    2015-05-01

    This work examines the role of shear and extensional strain on immiscible blend morphology, namely domain size, orientation, and co-continuity. The domain size reduces with surface tension similar to what is observed with isolated droplets. The domain size is shown to increase with shear strain due to coalescence. Hence the best mixing is found with low shear strains, i.e. low rates of shear and short durations of time. Extensional strain (extrusion draw ratio DR) reduces phase width and thickness with a DR-0.5 dependence, suggesting the transformation to a fibrilar morphology. The critical draw ratio for morphology transformation is approximately 7, in agreement with observations by Grace for droplet breakup in elongation. Fibrilar morphology is also consistent with a large increase in strain-to-break in the drawn film and with observed creep and optical scattering behavior.

  3. 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

  4. Evaluation of Thermally Induced Degradation of Branched Polypropylene by Using Rheology and Different Constitutive Equations

    Directory of Open Access Journals (Sweden)

    Jiri Drabek

    2016-08-01

    Full Text Available In this work, virgin as well as thermally degraded branched polypropylenes were investigated by using rotational and Sentmanat extensional rheometers, gel permeation chromatography and different constitutive equations. Based on the obtained experimental data and theoretical analysis, it has been found that even if both chain scission and branching takes place during thermal degradation of the tested polypropylene, the melt strength (quantified via the level of extensional strain hardening can increase at short degradation times. It was found that constitutive equations such as Generalized Newtonian law, modified White-Metzner model, Yao and Extended Yao models have the capability to describe and interpret the measured steady-state rheological data of the virgin as well as thermally degraded branched polypropylenes. Specific attention has been paid to understanding molecular changes during thermal degradation of branched polypropylene by using physical parameters of utilized constitutive equations.

  5. 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...

  6. Tip-splitting instabilities in the channel Saffman-Taylor flow of constant viscosity elastic fluids

    International Nuclear Information System (INIS)

    Vlad, D. H.; Maher, J. V.

    2000-01-01

    Boger fluids are used to study viscous fingering growth in viscoelastic fluids in channel Hele-Shaw flow. We have found that the viscous finger growing in the Boger fluid is unstable to tip splitting at high velocities, in a regime where a Newtonian viscous finger is stable. No fracturelike instabilities were observed. We show that the viscoelastic normal stress differences arising in shear and extensional flow reach very high values at shear and extensional rates comparable to those achieved at the tip of the finger at the onset of tip splitting, and the fluid becomes highly anisotropic. The viscoelastic stress could affect the dynamics of the finger and induce the tip-splitting instability. (c) 2000 The American Physical Society

  7. Metaphysics after Metaphysics: The Limitative Conception of First Philosophy in Kant

    OpenAIRE

    Günter Zöller

    2003-01-01

    The essay examines Kant’s Enlightenment conception of metaphysics as a science (Wissenschaft) to be kept free of ideological prejudice and extrarational cognitive resources and to be established under the conditions of public, intersubjectively valid discourse. I analyze Kant’s self-interpretation of his transcendental philosophy as “metaphysics of metaphysics” and argue for the extensional partial identity of the critique of metaphysics and the metaphysics so rendered possible. In particular...

  8. Multiple tectonic mode switches indicate short-duration heat pulses in a Mio-Pliocene metamorphic core complex, West Papua, Indonesia

    Science.gov (United States)

    White, L. T.; Hall, R.; Gunawan, I.

    2017-12-01

    The Wandaman Peninsula is a narrow (2 km) promontory in remote western New Guinea. The peninsula is almost entirely composed of medium- to high-grade metamorphic rocks considered to be associated with a Mio-Pliocene metamorphic core complex. Previous work has shown that the uplift and exhumation of the core complex has potentially brought some extremely young eclogite to the surface. These might be comparable to the world's youngest (4.3 Ma) eclogites found in the D'Entrecasteaux Islands at the opposite end of New Guinea. We show that tectonic history of this region is complex. This is because the metamorphic sequences in the Wandaman Peninsula record multiple phases of deformation, all within the last few million years. This is demonstrated through methodical collation of cross-cutting relations from field and microstructural studies across the peninsula. The first phase of deformation and metamorphism is associated with crustal extension and partial melting that took place at 5-7 Ma according to new U-Pb data from metamorphic zircons. This extensional phase ceased after a tectonic mode switch and the region was shortened. This is demonstrated by two phases of folding (1. recumbent and 2. open) that overprint the earlier extensional fabrics. All previous structures were later overprinted by brittle extensional faults and uplift. This extensional phase is still taking place today, as is indicated by submerged forests exposed along the coastline associated with recent earthquakes and hot springs. The sequence of metamorphic rocks that are exposed in the Wandaman Peninsula show that stress and thermal conditions can change rapidly. If we consider that the present is a key to the past, then such results can identify the duration of deformation and metamorphic events more accurately than in much older orogenic systems.

  9. Impact of nanomechanical resonances on lasing from electrically pumped quantum dot micropillars

    Energy Technology Data Exchange (ETDEWEB)

    Czerniuk, T., E-mail: Thomas.Czerniuk@tu-dortmund.de; Tepper, J. [Experimentelle Physik 2, TU Dortmund University, 44227 Dortmund (Germany); Akimov, A. V. [School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD (United Kingdom); Unsleber, S.; Schneider, C.; Kamp, M. [Technische Physik, Physikalisches Institut and Wilhelm Conrad Röntgen-Center for Complex Material Systems, University of Würzburg, Am Hubland, 97074 Würzburg (Germany); Höfling, S. [School of Physics and Astronomy, University of St Andrews, KY16 0SS St Andrews (United Kingdom); Yakovlev, D. R.; Bayer, M. [Experimentelle Physik 2, TU Dortmund University, 44227 Dortmund (Germany); Ioffe Physical-Technical Institute, Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation)

    2015-01-26

    We use a picosecond acoustics technique to modulate the laser output of electrically pumped GaAs/AlAs micropillar lasers with InGaAs quantum dots. The modulation of the emission wavelength takes place on the frequencies of the nanomechanical extensional and breathing (radial) modes of the micropillars. The amplitude of the modulation for various nanomechanical modes is different for every micropillar which is explained by a various elastic contact between the micropillar walls and polymer environment.

  10. Význam obecného výrazu ve Fregově pojetí

    Czech Academy of Sciences Publication Activity Database

    Vlasáková, Marta

    2013-01-01

    Roč. 5, č. 1 (2013), s. 41-59 ISSN 1804-0969 R&D Projects: GA ČR(CZ) GA13-21076S Institutional support: RVO:67985955 Keywords : the reference of a general term * Frege's Sinn/Bedeutung * the extensional criterion of identity Subject RIV: AA - Philosophy ; Religion http://filosofiednes.ff.uhk.cz/index.php/hen/article/view/115

  11. Early paleozoic granitoids in the southern Vanoise basement: U-Pb geochronology of the Arpont meta-granite (Savoy, French Alps); Granitoides d`age paleozoique inferieur dans le socle de Vanoise meridionale: geochronologie U-Pb du metagranite de l`Arpont (Alpes de Savoir, France)

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, J.M. [Laboratoire de geodynamique des chaines alpines, LGCA-CISM, 73 - Le Bourget-du-Lac (France); Leterrier, J. [Centre de recherches petrographiques et geochimique, 54 - Vandoeuvre-les-Nancy (France)

    1997-12-01

    The U-Pb age of a meta-granite from southern Vanoise (Brianconnais` domain) at 479{+-} 4 Ma confirms hat the micaschists which dominate this pre-alpine basement are, at least, of Early Paleozoic age. The rare magmatic rocks occurring in Vanoise and showing alkaline affinities, may be compared to the orthogneisses belonging to the Cambrian-Ordovician extensional event well known in other parts of the Varican belt. (authors) 27 refs.

  12. Structural Evolution and Mobile Shale Deformation in the Eastern Niger Delta

    International Nuclear Information System (INIS)

    Wiener, R. W.; Aikhionbare, D. O. L.

    2002-01-01

    Regional cross-sections and restorations of the eastern delta constructed from 2D and 3D seismic data show the structural evolution of paired extensional contractional belts and the kinematic and geometric evolution of mobile shale. The delta consists of an updip extensional belt and downdip zones of transitional and contractional deformation linked by a regional detachment. The extensional belt is characterized by zones of N-dipping (counterregional) and S-dipping (regional) normal faults.In the regional fault trend, sediment accommodation space is created largely by lateral movement of mobile substrate due to sediment loading and gravity. The transitional belt is characterized by low relief, shale-cored detachment folds and normal faults. The contractional belt consists of 2 parts, the high relief shale-cored detachment fold belt (mobile shale) and the fold/thrust belt: In the mobile shale belt, anticlines are generally symmetric and characterized by parallel-folded cover and highly variable thickness in the underlying ductile shale zone.Palinspastic restoration of the mobile shale by area balance shows a high degree of lateral and vertical mobility. Isostatic restoration of the depositional wedge that is the precursor to the mobile shale suggests lateral movement of 10s of kms from the extensional to the contractional domain. The fold and thrust belt is characterized by a train of asymmetric fault-related folds. The zone of ductile substrate is thin in this area, which may account for the change in structural style from high relief detachment folds in the mobile shale belt to a more classic fold/thrust belt style to the south

  13. Hydrothermal system in Southern Grass Valley, Pershing County, Nevada

    Energy Technology Data Exchange (ETDEWEB)

    Welch, A.H.; Sorey, M.L.; Olmsted, F.H.

    1981-01-01

    Southern Grass Valley is a fairly typical extensional basin in the Basin and Range province. Leach Hot Springs, in the southern part of the valley, represents the discharge end of an active hydrothermal flow system with an estimated deep aquifer temperature of 163 to 176/sup 0/C. Results of geologic, hydrologic, geophysical and geochemical investigations are discussed in an attempt to construct an internally consistent model of the system.

  14. Map view restoration of Aegean-West Anatolian accretion and extension since the Eocene

    Science.gov (United States)

    van Hinsbergen, Douwe J. J.; Schmid, Stefan M.

    2012-10-01

    The Aegean region (Greece, western Turkey) is one of the best studied continental extensional provinces. Here, we provide the first detailed kinematic restoration of the Aegean region since 35 Ma. The region consists of stacked upper crustal slices (nappes) that reflect a complex paleogeography. These were decoupled from the subducting African-Adriatic lithospheric slab. Especially since ˜25 Ma, extensional detachments cut the nappe stack and exhumed its metamorphosed portions in metamorphic core complexes. We reconstruct up to 400 km of trench-perpendicular (NE-SW) extension in two stages. From 25 to 15 Ma, the Aegean forearc rotated clockwise relative to the Moesian platform around Euler poles in northern Greece, accommodated by extensional detachments in the north and an inferred transfer fault SE of the Menderes massif. The majority of extension occurred after 15 Ma (up to 290 km) by opposite rotations of the western and eastern parts of the region. Simultaneously, the Aegean region underwent up to 650 km of post-25 Ma trench-parallel extension leading to dramatic crustal thinning on Crete. We restore a detachment configuration with the Mid-Cycladic Lineament representing a detachment that accommodated trench-parallel extension in the central Aegean region. Finally, we demonstrate that the Sakarya zone and Cretaceous ophiolites of Turkey cannot be traced far into the Aegean region and are likely bounded by a pre-35 Ma N-S fault zone. This fault became reactivated since 25 Ma as an extensional detachment located west of Lesbos Island. The paleogeographic units south of the İzmir-Ankara-Sava suture, however, can be correlated from Greece to Turkey.

  15. 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...

  16. 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 ...

  17. Self-driven particles in linear flows and trapped in a harmonic potential

    Science.gov (United States)

    Sandoval, Mario; Hidalgo-Gonzalez, Julio C.; Jimenez-Aquino, Jose I.

    2018-03-01

    We present analytical expressions for the mean-square displacement of self-driven particles in general linear flows and trapped in a harmonic potential. The general expressions are applied to three types of linear flows, namely, shear flow, solid-body rotation flow, and extensional flow. By using Brownian dynamics simulations, the effect of trapping and external linear flows on the particles' distribution is also elucidated. These simulations also enabled us to validate our theoretical results.

  18. 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.

  19. 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.

  20. On the "viscosity maximum" during the uniaxial extension of a low density polyethylene

    OpenAIRE

    Burghelea, Teodor I.; Stary, Zdenek; Muenstedt, Helmut

    2010-01-01

    An experimental investigation of the viscosity overshoot phenomenon observed during uniaxial extension of a low density polyethylene is pre- sented. For this purpose, traditional integral viscosity measurements on a Muenstedt type extensional rheometer are combined with local mea- surements based on the in-situ visualization of the sample under exten- sion. For elongational experiments at constant strain rates within a wide range of Weissenberg numbers (Wi), three distinct deformation regimes...

  1. Patrimonio territorial y arquitectónico: El Plan Serena

    Directory of Open Access Journals (Sweden)

    Horacio Torrent Schneider

    2004-11-01

    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.

  2. State-of-stress in magmatic rift zones: Predicting the role of surface and subsurface topography

    Science.gov (United States)

    Oliva, S. J. C.; Ebinger, C.; Rivalta, E.; Williams, C. A.

    2017-12-01

    Continental rift zones are segmented along their length by large fault systems that form in response to extensional stresses. Volcanoes and crustal magma chambers cause fundamental changes to the density structure, load the plates, and alter the state-of-stress within the crust, which then dictates fracture orientation. In this study, we develop geodynamic models scaled to a effects of loading on state-of-stress. By modeling varying geometric arrangements, and density contrasts of topographic and subsurface loads, and with reasonable regional extensional forces, the resulting state-of-stress reveals the favored orientation for new intrusions. Although our models are generalized, they allow us to evaluate whether a magmatic system (surface and subsurface) can explain the observed stress rotation, and enable new intrusions, new faults, or fault reactivation with orientations oblique to the main border faults. Our results will improve our understanding of the different factors at play in these extensional regimes, as well as contribute to a better assessment of the hazards in the area.

  3. When intensions do not map onto extensions: Individual differences in conceptualization.

    Science.gov (United States)

    Hampton, James A; Passanisi, Alessia

    2016-04-01

    Concepts are represented in the mind through knowledge of their extensions (the class of items to which the concept applies) and intensions (features that distinguish that class of items). A common assumption among theories of concepts is that the 2 aspects are intimately related. Hence if there is systematic individual variation in concept representation, the variation should correlate between extensional and intensional measures. A pair of individuals with similar extensional beliefs about a given concept should also share similar intensional beliefs. To test this notion, exemplars (extensions) and features (intensions) of common categories were rated for typicality and importance respectively across 2 occasions. Within-subject consistency was greater than between-subjects consensus on each task, providing evidence for systematic individual variation. Furthermore, the similarity structure between individuals for each task was stable across occasions. However, across 5 samples, similarity between individuals for extensional judgments did not map onto similarity between individuals for intensional judgments. The results challenge the assumption common to many theories of conceptual representation that intensions determine extensions and support a hybrid view of concepts where there is a disconnection between the conceptual resources that are used for the 2 tasks. (c) 2016 APA, all rights reserved).

  4. Characterization of flows in micro contractions using micro PIV and CFD to study the protein aggregation process

    Science.gov (United States)

    Tovar-Lopez, Francisco J.; Mitchell, Arnan; Rosengarten, Gary

    2007-12-01

    Protein aggregation is arguably the most common and troubling manifestation of protein instability, encountered in almost all stages of protein drug development. The production process in the pharmaceutical industry can induce flows with shear and extensional components and high strain rates which can affect the stability of proteins. We use a microfluidic platform to produce accurately controlled strain regions in order to systematically study the main parameters of the flow involved in the protein aggregation. This work presents a characterization of the pressure driven flow encountered in arrays of micro channels. The micro channels were fabricated in polydimethyl siloxane (PDMS) using standard soft-lithography techniques with a photolithographically patterned KMPR mold. We present a relationship of the main geometrical variables of the micro channels and its impact on the extensional strain rate along the center line, for different cross sectional shapes and over a range of strain rates typically encountered in protein processing. Computational Fluid Dynamics (CFD) simulations have been carried out to gain more detailed local flow information, and the results have been validated with experiments. We show good agreement between the CFD and experiments and demonstrate the use of microfluidics in the production of a large range of controllable shear and extensional rates that can mimic large scale processing conditions.

  5. 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.

  6. 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.

  7. Tectonic evolution, structural styles, and oil habitat in Campeche Sound, Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Angeles-Aquino, F.J.; Reyes-Nunez, J.; Quezada-Muneton, J.M.; Meneses-Rocha, J.J. [Pemex Exploracion-Produccion, Mexico City (Mexico)

    1994-12-31

    Campeche Sound is located in the southern part of the Gulf of Mexico. This area is Mexico`s most important petroleum province. The Mesozoic section includes Callovian salt deposits; Upper Jurassic sandstones, anhydrites, limestones, and shales; and Cretaceous limestones, dolomites, shales, and carbonate breccias. The Cenozoic section is formed by bentonitic shales and minor sandstones and carbonate breccias. Campeche Sound has been affected by three episodes of deformation: first extensional tectonism, then compressional tectonism, and finally extensional tectonism again. The first period of deformation extended from the middle Jurassic to late Jurassic and is related to the opening of the Gulf of Mexico. During this regime, tilted block faults trending northwest-southwest were dominant. The subsequent compressional regime occurred during the middle Miocene, and it was related to northeast tangential stresses that induced further flow of Callovian salt and gave rise to large faulted, and commonly overturned, anticlines. The last extensional regime lasted throughout the middle and late Miocene, and it is related to salt tectonics and growth faults that have a middle Miocene shaly horizon as the main detachment surface. The main source rocks are Tithonian shales and shaly limestones. Oolite bars, slope and shelf 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.

  8. On the formation and evolution of the Pannonian basin: constraints derived from the orogenic collapse recorded at the junction between Carpathians and Dinarides

    Science.gov (United States)

    Matenco, L. C.; Radivojevic, D.

    2012-04-01

    Formation and evolution of back-arc basins is related to the evolution of subduction zones, resulting geometries being dependent on the interplay between the velocity of retreating slabs and boundary conditions that often limit rapid subduction systems. Classical models of evolution in the Alps-Carpathians-Dinaridic domain assume that the formation of the Pannonian back-arc basin is related to the rapid roll-back of an European slab and the invasion of Tisza-Dacia and ALCAPA upper plate blocks into the so-called Carpathians embayment starting at ~20Ma. The general mechanism assumes a gradual evolution, an initial mechanical phase of extensional detachments being recognized near the transition between the Alps and the Pannonian basin was subsequently followed by upper crustal normal faulting and a thermal phase during the Middle-late Miocene times that affected the central part of the Pannonian basin. A key area of the entire system often neglected by kinematic studies is the connection between South Carpathians and Dinarides. Here, regional seismic lines traversing the entire Serbian part of the Pannonian basin were calibrated with well data in order to derive an evolutionary model. The deformation is dominantly expressed by the formation of extensional (half-)grabens that are the brittle expression of large-scale extensional detachments. In contrast with previous interpretation restricting the syn-rift phase to the Middle Miocene, the geometry of normal faults and the associated syn-kinematic sedimentation allows the definition of a continuous Early to Late Miocene extensional evolution that was followed by the formation of isolated uplifted areas during the subsequent Pliocene - Quaternary inversion. The orientation of these (half-)grabens changes gradually from W-E to NW-SE and then to N-S, suggesting that the present-day strike of faults is the effect of a clockwise rotational mechanism of South Carpathians and Apuseni Mountains in respect to Dinarides. The S

  9. Mechanical properties of conjugate faults in the Makran accretionary prism estimated from InSAR observations of coseismic deformation due to the 2013 Baluchistan (Mw 7.7) earthquake

    Science.gov (United States)

    Dutta, R.; Harrington, J.; Wang, T.; Feng, G.; Vasyura-Bathke, H.; Jonsson, S.

    2017-12-01

    Interferometric Synthetic Aperture Radar (InSAR) measurements allow us to study various mechanical and rheological properties around faults. For example, strain localizations along faults induced by nearby earthquakes observed by InSAR have been explained by the elastic response of compliant fault zones (CFZ) where the elastic moduli is reduced with respect to that of the surrounding rock. We observed similar strain localizations (up to 1-3 cm displacements in the line-of-sight direction of InSAR) along several conjugate faults near the rupture of the 2013 Mw7.7 Baluchistan (Pakistan) earthquake in the accretionary prism of the Makran subduction zone. These conjugate compliant faults, which have strikes of N30°E and N45°W, are located 15-30 km from the mainshock fault rupture in a N-S compressional stress regime. The long-term geologic slip direction of these faults is left-lateral for the N30°E striking faults and right-lateral for the N45°W striking faults. The 2013 Baluchistan earthquake caused WSW-ENE extensional coseismic stress changes across the conjugate fault system and the observed strain localizations shows opposite sense of motion to that of the geologic long-term slip. We use 3D Finite Element modeling (FEM) to study the effects extensional coseismic stresses have on the conjugate CFZs that is otherwise loaded in a compressional regional stress. We use coseismic static displacements due to the earthquake along the FEM domain boundaries to simulate the extensional coseismic stress change acting across the fault system. Around 0.5-2 km wide CFZs with reduction in shear modulus by a factor of 3 to 4 can explain the observed InSAR strain localizations and the opposite sense of motion. The InSAR measurements were also used to constrain the ranges of the length, width and rigidity variations of the CFZs. The FEM solution shows that the N45°W striking faults localize mostly extensional strain and a small amount of left-lateral shear (opposite sense to

  10. Electivities and resource use by an assemblage of lizards endemic to the dunes of the São Francisco River, northeastern Brazil

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    Pedro L.B. Rocha

    2005-01-01

    Full Text Available This study describes the pattern of resource use by one assemblage of lizards inhabiting a desert-like dune field in the Brazilian Caatinga. We evaluated food and microhabitat availability and phases of lizard activity, as well as use of, and electivities for, food and microhabitats. Six of the seven most abundant species are endemic to the dunes, and their diets under-represented arthropods possessing chemical defenses. The two fossorial gymnophthalmids were similar in presenting no electivities for microhabitat but differed in diet, electivities for food and phase of activity. The five species of epigeous lizards include one group presenting positive electivities for protected and shaded microhabitats (Procellosaurinus erythrocercus, Briba brasiliana, and Tropidurus psammonastes and another presenting negative electivities for such microhabitats (Eurolophosaurus divaricatus and Cnemidophorus spec. nov.. The tropidurid T. psammonastes presented the earliest activity in the morning, the strongest positive electivities for protected and shaded areas and negative electivity for exposed areas, and was the only species to present high positive electivity for ants. The only other tropidurid in the area, E. divaricatus, also ate ants but presented positive electivity for flowers. The medium-sized teiid Cnemidophorus spec. nov. showed the highest negative electivity for shaded areas, high positive electivity for open areas, and high negative electivity for protected areas. This pattern leads to use of microhabitat that is similar to that of E. divaricatus, which has a very different diet, and different from that of T. psammonastes, whose diet is comparable in the consumption of insect larvae and large-sized items. We discuss the evolution of the detected patterns of resource electivities.Este estudo descreve o padrão de uso de recursos por uma assembléia de lagartos de um campo de dunas da Caatinga. Avaliamos a disponibilidade de recursos e as fases

  11. Composição florística e estrutura da comunidade arbórea em uma floresta estacional decidual em afloramento calcário (Fazenda São José, São Domingos, GO, bacia do rio Paranã Floristic composition and structure of the tree community in a deciduous forest on a limestone outcrop in São Domingos, Goiás, Paranã river basin, Brazil

    Directory of Open Access Journals (Sweden)

    Luciana Álvares da Silva

    2003-06-01

    Full Text Available A bacia do rio Paranã (Goiás e Tocantins com 5.940.382ha, tem alta diversidade de fitofisionomias, incluindo a floresta estacional decidual sobre afloramento calcário, que ainda não foi estudada nesta região. Este trabalho objetivou o levantamento quantitativo da vegetação arbórea de uma floresta estacional decidual sobre afloramento calcário (13°49'34''S e 46º 41'55''W; 478m de altitude na fazenda São José, São Domingos, GO. Foram demarcadas cinco linhas a intervalos de 100m, onde foram aleatoriamente alocadas 25 parcelas permanentes de 20 × 20m (1,0 ha. Em cada parcela foram amostrados todos os indivíduos com diâmetro à altura do peito (DAP igual ou maior que 5cm, onde foram medidos o DAP e a altura, e identificadas as espécies. Foram amostrados 588 indivíduos (536 vivos e 52 mortos ainda em pé, pertencentes a 36 espécies, 31 gêneros e 21 famílias, com índice de Shannon 2,99 e Equabilidade 0,83. As principais espécies em valor de importância (VI, foram: Tabebuia impetiginosa (43,81, Aspidosperma pyrifolium (35,64, Luetzelburgia sp. (21,77, Commiphora leptophloeos (18,79, Myracrodruon urundeuva (15,79, Pseudobombax tomentosum (13,42, Combretum duarteanum (13,04, Luehea divaricata (12,24, Cabralea canjerana (11,99, Ficus pertusa (11,82, Jacaranda brasiliana (11,68 e Aspidosperma sp. (10,57 que juntas somaram 73,5% do VI total, enquanto as 24 espécies restantes somaram 26,5%. Esta floresta é similar, em termos de diversidade, a outras áreas de afloramentos na região.The Paranã river basin (States of Goiás and Tocantins, Brazil, with 5,940,382 ha, has many different plant physiognomies, including the deciduous forest on limestone outcrops which has not yet been studied in this region. In this paper we present the structure of the tree community of a deciduous forest on a limestone outcrop (13º49'34'' S; 46º 41'55'' W in São Domingos municipality, Goiás State, Brazil. Twenty-five plots of 20m × 20m (400m² were

  12. 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

  13. Aproveitamento industrial de marisco na produção de lingüiça Shellfish industrial utilization to produce sausage

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    Eliete da Silva Bispo

    2004-12-01

    Full Text Available Foram estudadas as condições do processamento e a aceitabilidade da lingüiça de vongole (Anomalocardia brasiliana, além de avaliar a estabilidade do produto congelado sob os aspectos químico, físico-químico, microbiológico e sensorial. O produto final obedeceu a seguinte formulação: 48% vongole, 5% proteína texturizada de soja, 15% água, 25% gordura suína, 3% albumina, 2% pré-mistura (sais de cura e NaCl, 1,5% condimentos e 0,5% urucum. O produto congelado ficou armazenado à temperatura de -18ºC durante três meses; periodicamente foi avaliado quanto ao pH, umidade, proteínas, lipídios, NBV, índice de peróxidos, reação de Kreiss, quanto à presença de microrganismos patogênicos e toxigênicos e quanto à aparência, aroma, sabor, textura. Os resultados apontaram que a lingüiça de vongole teve uma boa aceitação, com IA entre 78-87% para todos os atributos avaliados, especialmente em relação ao sabor e textura. As amostras foram avaliadas como sabor ideal de marisco e sabor ideal de condimentos por 66,67% e 73,33% dos provadores, respectivamente. Os resultados com o teste de atitude de intenção de compra mostraram que 46,67% dos consumidores tinham intenção provável ou certa de compra do produto. Os resultados da avaliação microbiológica, físico-química, química e sensorial da lingüiça de vongole, indicaram que o produto manteve-se estável, durante 90 dias de armazenamento a temperatura de -18ºC.It was studied the process and the acceptibility of the vongole (Anomalocardia brasiliana sausage, beyond to evaluate the stability of the frozen product as to chemical, physico-chemical, microbiological and sensory aspects. The vongole sausage had the following formulation: 48% vongole, 5% soy protein, 15% water, 25% swine fat, 3% albumin, 2% blend of cure salts and NaCl, 1.5% flavouring, 0.5% colouring. The final product was stored during three months at -18ºC, and the shelf life study included pH, moisture

  14. 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.

  15. Molecular phylogenetics of the Brazilian giant bromeliads (Alcantarea, Bromeliaceae): implications for morphological evolution and biogeography.

    Science.gov (United States)

    Versieux, Leonardo M; Barbará, Thelma; Wanderley, Maria das Graças Lapa; Calvente, Alice; Fay, Michael F; Lexer, Christian

    2012-07-01

    The genus Alcantarea comprises near 30 species endemic to rocky outcrops from eastern Brazil. Most species are ornamental and several are threatened due to habitat loss and over collection. In this paper we examine the phylogenetics of Alcantarea and its relationship with the Brazilian members of Vriesea, a genus of which Alcantarea has been treated as a subgenus. We discuss the morphological evolution of the stamen position and its implication for pollination and the occurrence of Alcantarea in the Espinhaço mountain range rocky savanna-like habitat vegetation. DNA sequence data derived from two plastid markers (trnK-rps16, trnC-petN) and from a low copy nuclear gene (Floricaula/Leafy) together with 20 nuclear microsatellite loci were the data source to perform analyses and construct phylogenetic and Neighbor Joining trees for the genus. Alcantarea is well supported as monophyletic in both Bayesian and parsimony analyses, but sections of Vriesea, represented by the eastern Brazilian species, appear paraphyletic. Microsatellites delimit geographically isolated species groups. Nevertheless individuals belonging to a single species may appear related to distinct clusters of species, suggesting that hybridization and/or homoplasy and/or incomplete lineage sorting are also influencing the analysis based on such markers and may be the reasons for some unexpected results. Alcantarea brasiliana is hypothesized as putative hybrid between A. imperialis and A. geniculata. Spreading stamens, a morphological floral characteristic assumed to be related to Chiropterophily, apparently evolved multiple times within the genus, and invasion of rocky savanna-like habitat vegetation by Atlantic rainforest ancestors seems to have occurred multiple times as well. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Paleogeographical evolution of the Itapoa coastal plain, Northern coast of Santa Catarina, SC, Brazil

    International Nuclear Information System (INIS)

    Souza, Maria Cristina de; Angulo, Rodolfo Jose; angulo@geologia.ufpr.br; Pessenda, Luiz Carlos Ruiz

    2001-01-01

    The paper aims to characterize the paleogeographical evolution of the Itapoa coastal plain during the Quaternary and to compare this evolution with other proposed models. To reach the objectives the area was mapped in scale 1:50.000, sub-surface information were obtained from geotechnical drillings and paleosea-levels were inferred by radiocarbon dating performed on vermetids tubes, wood fragments and shells of Anomalocardia brasiliana samples. The paleosea-level reconstructions are consistent with the sea level curve proposed in previous works. The evolution model for the Itapoa coastal plain proposed in this work is similar to the model proposed for the coastal plain of Paranagua. The paleogeographical evolution of the Itapoa coastal plain can be summarized as: formation of fans during Lower Miocene, with sea level similar or lower than the present one; island-barrier formation during the Upper Pleistocene transgression maximum; formation of extensive regressive barriers and later dissection by a rectangular pattern drainage system, during sea level low stand; island barrier formation during the Holocene transgression maximum, with inlets associated to the present mouth of Sai-Mirim and Sai-Guacu rivers; formation of extensive regressive barriers during falling sea level period. During the Holocene regression, spits grew northward, moving northward the estuarine inlets as well. This drift direction is the same that was suggested for Parana and Santa Catarina north coast. During regression until present the Sai-Mirim River has eroded the Holocene barrier inland portion, that probably caused the erosion of most of the Holocene transgressive barrier-islands. (author)

  17. Environmental drivers of the benthic macroinvertebrates community in a hypersaline estuary (Northeastern Brazil

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    Carlinda Railly Ferreira Medeiros

    Full Text Available Abstract Introduction The estuarine community of benthic macroinvertebrates spatially varies in response to changes in environmental variables in these ecosystems. Understanding this variability helps our understanding the mechanisms structuring these communities. Aim Assess the structural aspects of the benthic macroinvertebrate community in a hypersaline estuary, and to relate to environmental variables that influence the community structure along the estuary. Methods The study was conducted at Tubarão river estuary in May 2015. We sampled two estuarine areas (upper and lower, and in each zone were sampled six points composed of two replicas, one sampled in sandy bottom and the other in muddy bottom. Samples of benthic macroinvertebrates and estuarine environmental variables were collected. Environmental drivers of the benthic macroinvertebrate community were determined by Distance-based Linear Models analysis. The contribution of individual species to the dissimilarity between the areas and substrate types were determined by analysis of the percentage of similarity. Results The composition of benthic macroinvertebrate community differed between the upper and lower areas, although it was similar between the muddy and sandy bottoms. The variation in the benthic community between areas was mainly related to the influence of salinity in the upper area. In the lower area, the variation of the macroinvertebrates was related to salinity, associated with other variables in the sandy (temperature, turbidity and dissolved oxygen and muddy (temperature, total dissolved solids and dissolved oxygen substrates. Taxa which contributed most to the dissimilarity between the upper and lower areas were Nereididae (17.89%, Anomalocardia brasiliana (15% and Cirratulidae (10.43%. Conclusions Salinity was the main driver of the structural aspects of the benthic macroinvertebrate community in the upper area of the estuary, although in the lower area a set of

  18. 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

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    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.

  19. Seasonal variation in the abundance and distribution of Anomalocardia flexuosa (Mollusca, Bivalvia, Veneridae in an estuarine intertidal plain

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    Jacqueline S. Silva-Cavalcanti

    2018-02-01

    Full Text Available Spatial and temporal density and biomass of the infaunal mollusk Anomalocardia flexuosa (Linnaeus, 1767 evaluated a tidal plain at Goiana estuary (Northeast Brazil. Three hundred and sixty core samples were taken during an annual cycle from three intertidal habitats (A, B and C. Shell ranged from 2.20 to 28.48 mm (15.08 ± 4.08 mm. Recruitment occurred more intensely from January to March. Total (0–1,129 g m−2 differed seasons (rainy and dry, with highest values in the early rainy season (221.0 ± 231.44 g m−2; and lowest values in the late dry season (57.34 ± 97 g m−2. The lowest occurred during the late rainy (319 ± 259 ind m−2 and early dry (496 ± 607 ind m−2 seasons. Extreme environmental situations (e.g., river flow, salinity and water temperature at the end of each season also affected density ranges (late dry: 0–5,798 ind m−2; late rainy: 0–1,170 ind m−2. A. flexuosa in the Goiana estuary presented a dominance of juvenile individuals (shell length < 20 mm, with high biomass main the recruitment period. Average shell length, density and biomass values suggest overfishing of the stock unit. A. flexuosa is an important food and income resource along its whole distribution range. The species was previously also known as Anomalocardia brasiliana (Gmelin, 1791.

  20. Plantas medicinais usadas para tratamentos dermatológicos, em comunidades da Bacia do Alto Paraguai, Mato Grosso

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    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.

  1. Antifungal activity of extracts of some plants used in Brazilian traditional medicine against the pathogenic fungus Paracoccidioides brasiliensis.

    Science.gov (United States)

    Johann, Susana; Cisalpino, Patricia Silva; Watanabe, Gisele Almeida; Cota, Betania Barros; de Siqueira, Ezequias Pessoa; Pizzolatti, Moacir Geraldo; Zani, Carlos Leomar; de Resende, Maria Aparecida

    2010-04-01

    Paracoccidioidomycosis (PCM) is a systemic granulomatous disease caused by Paracoccidioides brasiliensis Almeida (Onygenales) that requires 1-2 years of treatment. In the absence of drug therapy, the disease is usually fatal, highlighting the need for the identification of safer, novel, and more effective antifungal compounds. With this need in mind, several plants employed in Brazilian traditional medicine were assayed on P. brasiliensis and murine macrophages. Extracts were prepared from 10 plant species: Inga spp. Mill. (Leguminosae), Schinus terebinthifolius Raddi (Anacardiaceae), Punica granatum L. (Punicaceae), Alternanthera brasiliana Kuntze (Amaranthaceae), Piper regnellii CDC. (Piperaceae), P. abutiloides Kunth (Piperaceae), Herissantia crispa L. Briz. (Malvaceae), Rubus urticaefolius Poir (Rosaceae), Rumex acetosa L. (Polygonaceae), and Baccharis dracunculifolia DC. (Asteraceae). Hexane fractions from hydroalcoholic extracts of Piper regnellii and Baccharis dracunculifolia were the most active against the fungus, displaying minimum inhibitory concentration (MIC) values of 7.8 microg/mL and 7.8-30 mug/mL, respectively. Additionally, neither of the extracts exhibited any apparent cytotoxic effects on murine macrophages at 20 microg/mL. Analyses of these fractions using gas chromatography-mass spectrometry (GC-MS) showed that the major components of B. dracunculifolia were ethyl hydrocinnamate (14.35%) and spathulenol (16.02%), while the major components of the hexane fraction of Piper regnellii were 1-methoxy-4-(1-propenyl) benzene (21.94%) and apiol (21.29%). The activities of these fractions against P. brasiliensis without evidence of cytotoxicity to macrophages justify their investigation as a potential source of new chemical agents for the treatment of PCM.

  2. Mechanical algal disruption for efficient biodiesel extraction

    Science.gov (United States)

    Krehbiel, Joel David

    mass at the bubble center, and if the bubble-to-cell spacing is much larger than the cell radius, the flow around the cell is approximately extensional in the cell's frame of reference. It is known that the present algae are quasi-spherical with cytoplasmic viscosity approximately 100 times that of water, so the cell is approximated as a viscous sphere. Thus, conditions that cause cell disruption from an expanding microbubble are modeled as either steady inviscid extensional flow or steady point source flow over a viscous sphere. In the inviscid extensional flow model, the flow inside the sphere is dominated by viscous forces so the Stokes equation is solved with matched stresses at the sphere surface from the exterior inviscid extensional flow. The short-time deformation of the sphere surface suggests that inviscid extensional flow is insufficient to disrupt cells. This indicates that asymmetry of the flow over the sphere may be required to provide sufficient surface areal strain to rupture the cell. In a more detailed model, the bubble expansion is modeled as an expansion near a viscous sphere using finite element software. For conditions similar to those seen in the experiment, deformation shows similar scaling to disruption. The deformation in this model is significantly higher than predicted from the inviscid extensional flow model due to the effect of asymmetric flow on the cell membrane. Estimates suggest 21% average areal strain on the algal membrane is required to disrupt algal cells, and this result agrees well with areal strains typically required to disrupt cell membranes although the actual value would be lessened by the effect of an elastic membrane, which is neglected in the present model. The local areal strain on the sphere surface is a maximum closest to the point source, and there is compressive strain near theta = +/-pi/4 with theta the angle from the line between the cell center and the point source. The maximum local areal strain shows less

  3. Differential unroofing within the central metasedimentary Belt of the Grenville Orogen: constraints from 40Ar/39Ar thermochronology

    Science.gov (United States)

    Cosca, Michael A.; Essene, Eric J.; Kunk, Michael J.; Sutter, John F.

    1992-04-01

    An 40Ar/39Ar thermochronological investigation of upper greenschist to granulite facies gneiss, amphibolite and marble was conducted in the Central Metasedimentary Belt (CMB), Ontario, to constrain its cooling history. Incremental 40Ar/39Ar release spectra indicate that substantial differential unroofing occurred in the CMB between ˜ 1000 and ˜ 600 Ma. A consistent pattern of significantly older hornblende and phlogopite 40Ar/3Ar cooling ages on the southeast sides of major northeast striking shear zones is interpreted to reflect late displacement due to extensional deformation. Variations in hornblende 40Ar/39Ar age plateaus exceeding 200 Ma occur over distances less than 50 km with major age discontinuities occurring across the Robertson Lake shear zone and the Sharbot Lake mylonite zone which separate the Sharbot Lake terrane from the Elzevir and Frontenac terranes. Extensional displacements of up to 14 km are inferred between the Frontenac and Elzevir terranes of the CMB. No evidence for significant post argon-closure vertical displacement is indicated in the vicinity of the Perth Road mylonite within the Frontenac terrane. Variations of nearly 100 Ma in phlogopite 40Ar/39Ar plateau ages occur in undeformed marble on either side of the Bancroft Shear Zone. Phlogopites from sheared and mylonitized marble within the shear zone yield 40Ar/39Ar diffusional loss profiles, but have older geologically meaningless ages thought to reflect incorporation of excess argon. By ˜ 900 Ma, southeast directed extension was occurring throughout the CMB, possibly initiated along previous zones of compressional shearing. An easterly migration of active zones of extension is inferred, possibly related to an earlier, overall easterly migration of active zones of regional thrusting and easterly migration of an ancient subduction zone. The duration of extensional shearing is not well constrained, but must have ceased before ˜ 600 Ma as required by the deposition of overlying

  4. 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.

  5. Geometries of inversion structures and implication for hydrocarbon prospectivity in the Troms-Finnmark Fault Complex, SW Barents Sea

    Science.gov (United States)

    Zervas, Ioannis; Olakunle Omosanya, Kamaldeen; Lippard, Stephen John; Johansen, Ståle Emil; Marfo, George

    2017-04-01

    Several inversion structures have been reported in the Southwestern Barents Sea, however such structures are poorly understood in the Troms-Finnmark Fault Complex (TFFC). This study interpreted three-dimensional (3-D) seismic data mainly in the TFFC and several adjoining structural elements, such as the Harstad and Tromsø Basins, the Finnmark Platform and the Ringvassøy Loppa Fault Complex. The methods used here include detailed seismic interpretation, analysis of structural maps, and fault displacement characterization. Our results show several evidences of localized partial positive inversion, intermittent with rifting events of Middle Jurassic to Early Cretaceous age. The inversion structures are of Middle/Late Triassic to Early Cretaceous age and include snakehead geometries of inverted wedge structures, folds associated with extensional faults, small-scale stratigraphic inversion in a fault network and reverse drag geometries along planar to rotated fault planes. The axial planes of folds associated with extensional faults in the study area revealed two different episodes of contraction linked to either compressional or shearing movements. Causes of inversion may also include far-field stresses related to halokinesis in the Tromsø Basin and uplift of the Loppa High. Inversion structures have had an impact on hydrocarbon prospectivity and accumulation in the TFFC and surrounding basins. Our work shows that localized folds close to extensional faults positively change the geometries of traps within the Stø Fm. (reservoir) and the Hekkingen Fm. (cap rock). In contrast, folding observed in the potential source rock of the Hekkingen Fm. post-dates the timing of petroleum generation and migration. Reactivated faults in the TFFC can act as conduits for hydrocarbons or compromise the sealing integrity of the traps.

  6. Landscape evolution of the graben of Puerto Vallarta (west-central Mexico) using the analysis of landforms and stream long profiles

    Science.gov (United States)

    Castillo, Miguel

    2017-01-01

    The analysis of landforms and stream long profiles are useful tools that can provide information about the tectonic activity in the landscape. The west-central portion of Mexico is a region that is mostly dominated by an extensional tectonics initiated in the Miocene and continuing in the Quaternary, where there has also been a vast emission of volcanic products. Of particular importance is the graben of Puerto Vallarta which was formed during the extensional activity that opened the Gulf of California in the Miocene. Nevertheless, the geomorphology and landscape evolution of this structure has not been studied in detail. Here I present a study of the rivers, landforms and topography of Puerto Vallarta graben in order to assess its evolution, focusing on the evidences of its initial phase of formation. The geomorphological map elaborated in this study reveals the presence of lava flows and volcanic structures in the eastern sector of the graben. Here it is proposed that this volcanism occurred during the formation of the graben in the Miocene, nevertheless, radiometric dating of lavas is still required to determine the precise timing of this event. Analysis of stream long profiles confirms that knickpoints are propagating in the fluvial network at a rate of ∼0.07 to ∼0.7 mm yr-1 and these were probably triggered by a drop in the base-level of rivers during the graben formation. The rates of knickpoint retreat in the graben of Puerto Vallarta are slightly lower than those observed in other recent (Quaternary) tectonic areas, however, the migration rates of the graben of Puerto Vallarta were probably higher at the onset of the faulting. Here the analysis of landforms and stream long profiles were useful to elucidate one part of the evolution of the graben of Puerto Vallarta. This study emphasizes the importance of incorporating the tectonic geomorphology in future studies of the extensional zones of west-central Mexico.

  7. 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.

  8. 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

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    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.

  9. Three Types of Flower Structures in a Divergent-Wrench Fault Zone

    Science.gov (United States)

    Huang, Lei; Liu, Chi-yang

    2017-12-01

    Flower structures are typical features of wrench fault zones. In conventional studies, two distinct kinds of flower structures have been identified based on differences in their internal structural architecture: (1) negative flower structures characterized by synforms and normal separations and (2) positive flower structures characterized by antiforms and reverse separations. In addition to negative and positive flower structures, in this study, a third kind of flower structure was identified in a divergent-wrench fault zone, a hybrid characterized by both antiforms and normal separations. Negative flower structures widely occur in divergent-wrench fault zones, and their presence indicates the combined effects of extensional and strike-slip motion. In contrast, positive and hybrid flower structures occur only in fault restraining bends and step overs. A hybrid flower structure can be considered as product of a kind of structural deformation typical of divergent-wrench zones; it is the result of the combined effects of extensional, compressional, and strike-slip strains under a locally appropriate compressional environment. The strain situation in it represents the transition stage that in between positive and negative flower structures. Kinematic and dynamic characteristics of the hybrid flower structures indicate the salient features of structural deformation in restraining bends and step overs along divergent-wrench faults, including the coexistence of three kinds of strains (i.e., compression, extension, and strike-slip) and synchronous presence of compressional (i.e., typical fault-bend fold) and extensional (normal faults) deformation in the same place. Hybrid flower structures are also favorable for the accumulation of hydrocarbons because of their special structural configuration in divergent-wrench fault zones.

  10. Context recognition for a hyperintensional inference machine

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    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.

  11. Late Paleozoic to Mesozoic extension in southwestern Fujian Province, South China: Geochemical, geochronological and Hf isotopic constraints from basic-intermediate dykes

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    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.

  12. Exhumation of the Deylaman fault trend and its effects on the deformation style of the western Alborz belt in Iran

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    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.

  13. Rifting and reactivation of a Cretaceous structural belt at the northern margin of the South China Sea

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    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.

  14. 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.

  15. Employing 2D Forward Modeling of Gravity and Magnetic Data to Further Constrain the Magnitude of Extension Recorded by the Caetano Caldera, Nevada

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    Ritzinger, B. T.; Glen, J. M. G.; Athens, N. D.; Denton, K. M.; Bouligand, C.

    2015-12-01

    Regionally continuous Cenozoic rocks in the Basin and Range that predate the onset of major mid-Miocene extension provide valuable insight into the sequence of faulting and magnitude of extension. An exceptional example of this is Caetano caldera, located in north-central Nevada, that formed during the eruption of the Caetano Tuff at the Eocene-Oligocene transition. The caldera and associated deposits, as well as conformable caldera-filling sedimentary and volcanic units allow for the reconstruction of post Oligocene extensional faulting. Extensive mapping and geochronologic, geochemical and paleomagnetic analyses have been conducted over the last decade to help further constrain the eruptive and extensional history of the Caetano caldera and associated deposits. Gravity and magnetic data, that highlight contrasts in density and magnetic properties (susceptibility and remanence), respectively, are useful for mapping and modeling structural and lithic discontinuities. By combining existing gravity and aeromagnetic data with newly collected high-resolution gravity data, we are performing detailed potential field modeling to better characterize the subsurface within and surrounding the caldera. Modeling is constrained by published geologic map and cross sections and by new rock properties for these units determined from oriented drill core and hand samples collected from outcrops that span all of the major rock units in the study area. These models will enable us to better map the margins of the caldera and more accurately determine subsurface lithic boundaries and complex fault geometries, as well as aid in refining estimates of the magnitude of extension across the caldera. This work highlights the value in combining geologic and geophysical data to build an integrated structural model to help characterize the subsurface and better constrain the extensional tectonic history if this part of the Great Basin.

  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. Abbot Ice Shelf, structure of the Amundsen Sea continental margin and the southern boundary of the Bellingshausen Plate seaward of West Antarctica

    Science.gov (United States)

    Cochran, James R.; Tinto, Kirsty J.; Bell, Robin E.

    2015-05-01

    Inversion of NASA Operation IceBridge airborne gravity over the Abbot Ice Shelf in West Antarctica for subice bathymetry defines an extensional terrain made up of east-west trending rift basins formed during the early stages of Antarctica/Zealandia rifting. Extension is minor, as rifting jumped north of Thurston Island early in the rifting process. The Amundsen Sea Embayment continental shelf west of the rifted terrain is underlain by a deeper, more extensive sedimentary basin also formed during rifting between Antarctica and Zealandia. A well-defined boundary zone separates the mildly extended Abbot extensional terrain from the deeper Amundsen Embayment shelf basin. The shelf basin has an extension factor, β, of 1.5-1.7 with 80-100 km of extension occurring across an area now 250 km wide. Following this extension, rifting centered north of the present shelf edge and proceeded to continental rupture. Since then, the Amundsen Embayment continental shelf appears to have been tectonically quiescent and shaped by subsidence, sedimentation, and the advance and retreat of the West Antarctic Ice Sheet. The Bellingshausen Plate was located seaward of the Amundsen Sea margin prior to incorporation into the Antarctic Plate at about 62 Ma. During the latter part of its independent existence, Bellingshausen plate motion had a clockwise rotational component relative to Antarctica producing convergence across the north-south trending Bellingshausen Gravity Anomaly structure at 94°W and compressive deformation on the continental slope between 94°W and 102°W. Farther west, the relative motion was extensional along an east-west trending zone occupied by the Marie Byrd Seamounts. The copyright line for this article was changed on 5 JUN 2015 after original online publication.

  18. Navajo minettes in the Cerros de las Mujeres, New Mexico

    Science.gov (United States)

    Vaniman, D.; Laughlin, A. W.; Gladney, E. S.

    1985-06-01

    The Cerros de las Mujeres in west-central New Mexico are three mafic minette plugs that should be considered part of the Navajo volcanic fields on the central Colorado Plateau. This newly recognized occurrence extends the Navajo volcanic fields to the southeastern margin of the Colorado Plateau, within 45 km of the extensional tectonic setting in which the Mogollon ash-flow tuff cauldrons occur. The Cerros de las Mujeres provide additional evidence for contemporaneous sodic and potassic volcanism within the Navajo volcanic fields.

  19. Extension joints: a tool to infer the active stress field orientation (case study from southern Italy)

    Science.gov (United States)

    De Guidi, Giorgio; Caputo, Riccardo; Scudero, Salvatore; Perdicaro, Vincenzo

    2013-04-01

    An intense tectonic activity in eastern Sicily and southern Calabria is well documented by the differential uplift of Late Quaternary coastlines and by the record of the strong historical earthquakes. The extensional belt that crosses this area is dominated by a well established WNW-ESE-oriented extensional direction. However, this area is largely lacking of any structural analysis able to define the tectonics at a more local scale. In the attempt to fill this gap of knowledge, we carried out a systematic analysis of extension joint sets. In fact, the systematic field collection of these extensional features, coupled with an appropriate inversion technique, allows to determine the characteristic of the causative tectonic stress field. Joints are defined as outcrop-scale mechanical discontinuities showing no evidence of shear motion and being originated as purely extensional fractures. Such tectonic features are one of the most common deformational structures in every tectonic environment and particularly abundant in the study area. A particular arrangement of joints, called "fracture grid-lock system", and defined as an orthogonal joint system where mutual abutting and crosscutting relationships characterize two geologically coeval joint sets, allow to infer the direction and the magnitude of the tectonic stress field. We performed the analyses of joints only on Pleistocene deposits of Eastern Sicily and Southern Calabria. Moreover we investigated only calcarenite sediments and cemented deposits, avoiding claysh and loose matrix-supported clastic sediments where the deformation is generally accomodated in a distributed way through the relative motion between the single particles. In the selection of the sites, we also took into account the possibility to clearly observe the geometric relationships among the joints. For this reason we chose curvilinear road cuts or cliffs, wide coastal erosional surfaces and quarries. The numerical inversions show a similar stress

  20. Composition driven structural instability in perovskite ferroelectrics

    Directory of Open Access Journals (Sweden)

    Chao Xu

    2017-04-01

    Full Text Available Ferroelectric solid solutions usually exhibit enhanced functional properties at the morphotropic phase boundary separating two ferroelectric phases with different orientations of polarization. The underlying mechanism is generally associated with polarization rotational instability and the flattened free energy profile. In this work we show that the polarization extensional instability can also be induced at the morphotropic phase boundary beyond the reported polar-nonpolar phase boundary. The piezoelectricity enhanced by this mechanism exhibits excellent thermal stability, which helps to develop high performance piezoelectric materials with good temperature stability.

  1. Dinosaur tectonics

    DEFF Research Database (Denmark)

    Graversen, Ole; Milàn, Jesper; B. Loope, David

    2007-01-01

    for foot movements and weight distribution in the feet. During the end of the weight-bearing phase of the stride, the weight of the animal was transferred to the front of the digits, creating a rotated disc below the foot that was bounded by an extensional fault at the front and a thrust ramp toward...... of the undertrack. The total length of the tectonic disturbance created by the dinosaur is up to three times that of the original footprint. Early, near-surface cementation gave the substrate the rheological properties necessary for development of the observed structures....

  2. Evaluación de la tolerancia al estrés hídrico en genotipos de papa criolla (Solanum phureja Juz et Buk)

    OpenAIRE

    Díaz Valencia, Paula Andrea

    2016-01-01

    Prologo: La papa criolla (Solanum phureja Juz et Buk) es producida a nivel nacional en los departamentos de Cundinamarca, Boyacá y Nariño y, en menor proporción, en Antioquia, Santander, Norte de Santander, Cauca y Tolima (Secretaria de Agricultura y Desarrollo Económico- Gobernación de Cundinamarca, 2009). Es un cultivo de pequeñas extensiones, de economía campesina y baja tecnología (Jaramillo y Botero, 2007). Colombia es el primer productor mundial de papa criolla, producto con ampli...

  3. LOS PROCESOS DE PRODUCCIÓN Y SU INCIDENCIA EN LA CALIDAD DEL CHOCOLATE, EN LA FÁBRICA ASOCIATIVA DE LA CORPORACIÓN “LA PEPA DE ORO”. CANTÓN VINCES, PROVINCIA DE LOS RÍOS. AÑO 2015.

    OpenAIRE

    Saucedo Aguiar, Álvaro Edmundo

    2016-01-01

    Este proyecto busca contribuir con el desarrollo de la industria cacaotera en el Cantón Vinces, puesto que es aquí donde se encuentra el mejor cacao del Ecuador situación dada por las condiciones de clima y suelo, no obstante la comercialización de este producto siempre ha sido como materia prima es decir en grano. Esta característica ha sido por mucho tiempo una limitante para que los productores que tienen pequeñas extensiones de tierras dedicadas al cultivo de cacao no obtengan mayores ing...

  4. Geologic map of the Topock 7.5’ quadrangle, Arizona and California

    Science.gov (United States)

    Howard, Keith A.; John, Barbara E.; Nielson, Jane E.; Miller, Julia M.G.; Wooden, Joseph L.

    2013-01-01

    The Topock quadrangle exposes a structurally complex part of the Colorado River extensional corridor and also exposes deposits that record landscape evolution during the history of the Colorado River. Paleoproterozoic gneisses and Mesoproterozoic granitoids and intrusive sheets are exposed through tilted cross-sectional thicknesses of many kilometers. Intruding them are a series of Mesozoic to Tertiary igneous rocks including dismembered parts of the Late Cretaceous Chemehuevi Mountains Plutonic Suite. Plutons of this suite in Arizona, if structurally restored for Miocene extension, formed cupolas capping the Chemehuevi Mountains batholith in California. Thick (1–3 km) Miocene sections of volcanic rocks, sedimentary breccias, conglomerate, and sandstone rest nonconformably on the Proterozoic rocks and record the structural and depositional evolution of the Colorado River extensional corridor. Four major Miocene low-angle normal faults and a steep block-bounding fault that developed during this episode divide the deformed rocks of the quadrangle into major structural plates and tilted blocks in and east of the Chemehuevi Mountains core complex. The low-angle faults attenuate crustal section, superposing supracrustal and upper crustal rocks against gneisses and granitoids originally from deeper crustal levels. The transverse block-bounding Gold Dome Fault Zone juxtaposes two large hanging-wall blocks, each tilted 90°, and the fault zone splays at its tip into folds in layered Miocene rocks. A synfaulting intrusion occupies the triangular zone where the folded strata detached from an inside corner along this fault between the tilt blocks. Post-extensional upper Miocene to Quaternary strata, locally deformed, record post-extensional landscape evolution, including several Pliocene and younger aggradational episodes in the Colorado River valley and intervening degradation episodes. The aggradational sequences include (1) the Bouse Formation, (2) fluvial deposits

  5. Caractérisation géochimique des dykes basiques du massif de les Saras (Mayombe Congolais, Afrique Centrale): conséquences géodynamiquesGeochemical characterizations of basic dykes of the Saras massif (Congolese Mayombe Belt, Central Africa): geodynamic implications

    Science.gov (United States)

    Boni, J. Mpemba; Vellutini, P. J.

    1992-02-01

    The Saras granodioritic massif is one of the Eburnean intrusive plutons of the Mayombe Belt. (South-West Congo, Central Africa) It is crosscut by a system of basic dykes, of diversified composition. Petrographic data and a comparative geochemical study, using incompatible trace elements, shows a tholeiitic transitional affinity, and allow us to suggest that these dykes are continental basaltic suites, from extensive areas. This basic magmatism, scattered in the whole Congo Craton, marks a widespread extensional episode in relation with the formation of subsidence basins or true aulacogens, at about 970 Ma (Pan African).

  6. Late Mesozoic basin and range tectonics and related magmatism in Southeast China

    Directory of Open Access Journals (Sweden)

    Dezi Wang

    2012-03-01

    Full Text Available During the Late Mesozoic Middle Jurassic–Late Cretaceous, basin and range tectonics and associated magmatism representative of an extensional tectonic setting was widespread in southeastern China as a result of Pacific Plate subduction. Basin tectonics consists of post-orogenic (Type I and intra-continental extensional basins (Type II. Type I basins developed in the piedmont and intraland during the Late Triassic to Early Jurassic, in which coarse-grained terrestrial clastic sediments were deposited. Type II basins formed during intra-continental crustal thinning and were characterized by the development of grabens and half-grabens. Graben basins were mainly generated during the Middle Jurassic and were associated with bimodal volcanism. Sediments in half-grabens are intercalated with rhyolitic tuffs and lavas and are Early Cretaceous in age with a dominance of Late Cretaceous–Paleogene red beds. Ranges are composed of granitoids and bimodal volcanic rocks, A-type granites and dome-type metamorphic core complexes. The authors analyzed lithological, geochemical and geochronological features of the Late Mesozoic igneous rock assemblages and proposed some geodynamical constraints on forming the basin and range tectonics of South China. A comparison of the similarities and differences of basin and range tectonics between the eastern and western shores of the Pacific is made, and the geodynamical evolution model of the Southeast China Block during Late Mesozoic is discussed. Studied results suggest that the basin and range terrane within South China developed on a pre-Mesozoic folded belt was derived from a polyphase tectonic evolution mainly constrained by subduction of the western Pacific Plate since the Late Mesozoic, leading to formation of various magmatism in a back-arc extensional setting. Its geodynamic mechanism can compare with that of basin and range tectonics in the eastern shore of the Pacific. Differences of basin and range

  7. Optimización de la productividad de una empresa mediante la implementación de Lean Manufacturing

    OpenAIRE

    Caballero Fernández, Álvaro

    2015-01-01

    Este proyecto pretende estudiar la aplicación de las técnicas y herramientas propias del Lean Manufacturing en el proceso de generación de producto final de Sangrá Hair International, S.A., empresa distribuidora de extensiones para el pelo, con el fin de conseguir mejorar su productividad. En primer lugar se hará una búsqueda de información de conceptos teóricos en cuanto a implantación de técnicas como el SMED o el método de las 5S, entre otros, y paralelamente se analizará...

  8. Flow and breakup in extension of low-density polyethylene

    DEFF Research Database (Denmark)

    Rasmussen, Henrik; Fasano, Andrea

    2018-01-01

    The breakup during the extension of a low-density polyethylene Lupolen 1840D, as observed experimentally by Burghelea et al. (J Non-Newt Fluid Mech 166:1198–1209 2011), was investigated. This was observed during the extension of an circular cylinder with radius R0 = 4 mm and length L0 = 5mm...... the error bars as reported experimentally by Burghelea et al. (J Non-Newt Fluid Mech 166:1198–1209 2011). At low extensional rates, the measurements were considerably above the calculated ones. A very small relative suppression in the surface (0.1%) was required to achieve an agreement with all measurements...

  9. Dating an actively exhuming metamorphic core complex, the Suckling Dayman Massif in SE Papua New Guinea

    Science.gov (United States)

    Oesterle, J.; Seward, D.; Little, T.; Stockli, D. F.; Mizera, M.

    2016-12-01

    Low-temperature thermochronology is a powerful tool for revealing the thermal and kinematic evolution of metamorphic core complexes (MCCs). Most globally studied MCCs are ancient, partially eroded, and have been modified by deformation events that postdate their origin. The Mai'iu Fault is a rapidly slipping active low-angle normal fault (LANF) in the Woodlark Rift in Papua New Guinea that has exhumed a >25 km-wide (in the slip direction), and over 3 km-high domal fault surface in its footwall called the Suckling-Dayman massif. Some knowledge of the present-day thermal structure in the adjacent Woodlark Rift, and the pristine nature of this active MCC make it an ideal candidate for thermochronological study of a high finite-slip LANF. To constrain the thermal and kinematic evolution of this MCC we apply the U/Pb, fission-track (FT) and (U-Th)/He methods. Zircon U/Pb analyses from the syn-extensional Suckling Granite that intrudes the footwall of the MCC yield an intrusion age of 3.3 Ma. Preliminary zircon FT ages from the same body indicate cooling below 300 °C at 2.7 Ma. Ages decrease to 2.0 Ma with increasing proximity to the Mai'iu Fault and imply cooling controlled by tectonic exhumation. Almost coincident zircon U/Pb and FT ages from the nearby syn-extensional Mai'iu Monzonite, on the other hand, record extremely rapid cooling from magmatic temperatures to 300 °C at 2 Ma. As apparent from the preliminary He extraction stage, these syn-extensional plutons have young zircon and apatite (U-Th)/He ages. These initial results suggest that the Mai'iu Fault was initiated as an extensional structure by 3.3 Ma. We infer that it reactivated an older ophiolitic suture that had emplaced the Papuan Ultramafic body in the Paleogene. Rapid cooling of the Mai'iu Monzonite indicates that it was intruded into a part of the MCC's footwall that was already shallow in the crust by 2 Ma. This inference is further supported by the mineral andalusite occurring in the contact

  10. Early Paleozoic U-Pb age of zircons from meta-granophyres f the Grand-Saint-Bernard nappe (zona interna, Aosta Valley, Italy); Age paleozoique inferieur (U-Pb sur zircon) de metagranophyres de la nappe du Grand-Saint-Bernard (zona interna, Vallee d'Aoste, Italie)

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, J.M. [Laboratoire de Geodynamique des Chaines Alpines, LGCA, Campus Scientifique, 73 - Le Bourget-du-Lac (France)

    2000-04-01

    The U-Pb age of a meta-granophyre from the Val de Rhemes (Brianconnais basement of the Aosta valley) of 511{+-}9 Ma suggests that the micaschists which dominate the pre-alpine basement of the Grand-Saint-Bernard Nappe are, in part, of Early Paleozoic age. The Brianconnais domain is characterized by a Cambrian to Ordovician alkalineto sub-alkaline (monzonitic) magmatism, similar in age to orthogneisses known in other parts of the Variscan belt and generally interpreted as related to an extensional event. (authors)

  11. Joint time-frequency analysis of ultrasonic signal

    International Nuclear Information System (INIS)

    Oh, Sae Kyu; Nam, Ki Woo; Oh, Jung Hwan; Lee, Keun Chan; Jang, Hong Keun

    1998-01-01

    This paper examines the propagation of Lamb (or plate) waves in anisotropic laminated composite plates. The dispersion relations are explicitly derived using the classical plate theory (CLT), the first-order shear deformation theory (FSDT) and the exact solution (ES), Attention is paid to the lowest antisymmetric (flexural) and lowest symmetric(extensional) modes in the low frequency, long wavelength limit. Different values of shear correction factor were tested in FSDT and comparisons between flexural wave dispersion curves were made with exact results to asses the range of validity of approximate plate theories in the frequency domain.

  12. Ingeniería de software de sistemas distribuidos de tiempo real modelización y evaluación de las restricciones de tiempo

    OpenAIRE

    De Giusti, Armando Eduardo; Ramón, Hugo Dionisio; Fernández, Pamela; Artime, Andrea

    1998-01-01

    Se presenta un análisis de las extensiones en la metodología clásica de análisis y diseño de software, orientada a sistemas distribuidos de tiempo real (SDTR). En particular se discute el modo de modelizar y verificar las restricciones de tiempo, utilizando Redes de Petri extendidas. A modo de ejemplo concreto de aplicación se analiza el desarrollo de un sistema de software que detecta en tiempo real el corte de cables telefónicos troncales y utiliza información de GIS para alertar a ...

  13. A Middle-Upper Miocene fluvial-lacustrine rift sequence in the Song Ba Rift, Vietnam

    DEFF Research Database (Denmark)

    Lars H., Nielsen; Henrik I., Petersen; Nguyen D., Dau

    2007-01-01

    The small Neogene Krong Pa graben is situated within the continental Song Ba Rift, which is bounded by strike-slip faults that were reactivated as extensional faults in Middle Miocene time. The 500 m thick graben-fill shows an overall depositional development reflecting the structural evolution...... development sedimentation rate outpaced the formation of accommodation space and fluvial activity increased again. During periods when the general sedimentation rate was in balance with the creation of accommodation space the environment changed frequently between lake deposition and intermittent vigorous...

  14. Basaltic volcanic episodes of the Yucca Mountain region

    Energy Technology Data Exchange (ETDEWEB)

    Crowe, B.M.

    1990-03-01

    The purpose of this paper is to summarize briefly the distribution and geologic characteristics of basaltic volcanism in the Yucca Mountain region during the last 10--12 Ma. This interval largely postdates the major period of silicic volcanism and coincides with and postdates the timing of major extensional faulting in the region. Field and geochronologic data for the basaltic rocks define two distinct episodes. The patterns in the volume and spatial distribution of these basaltic volcanic episodes in the central and southern part of the SNVF are used as a basis for forecasting potential future volcanic activity in vicinity of Yucca Mountain. 33 refs., 2 figs.

  15. Reestructurados de pollo saludables, evaluación del efecto de varias estrategias tecnológicas combinadas.

    OpenAIRE

    BOARI DE GREISSING, VIRGINIA MABEL

    2014-01-01

    La innovación juega un rol clave en el desarrollo de nuevos productos y extensiones de línea. La reformulación de productos cárnicos es una estrategia, que aplica la industria actual, basada en el conocimiento de las necesidades y expectativas de los consumidores. Siguiendo estas tendencias se desarrolla un reestructurado de pollo con fibra soluble y omega 3, sin el agregado de grasa y sal. Para proteger los omega 3 de la autoxidación se emplean métodos de cocción a calor moderado y vacío en...

  16. Method for in-situ nondestructive measurement of Young's modulus of plate structures

    Science.gov (United States)

    Huang, Jerry Qixin (Inventor); Perez, Robert J. (Inventor); DeLangis, Leo M. (Inventor)

    2003-01-01

    A method for determining stiffness of a composite laminate plate entails disposing a device for generating an acoustical pulse against a surface of the plate and disposing a detecting device against the same surface spaced a known distance from the pulse-generating device, and using the pulse-generating device to emit a pulse so as to create an extensional wave in the plate. The detecting device is used to determine a time of flight of the wave over the known distance, and the wave velocity is calculated. A Young's modulus of the plate is determined based on the wave velocity. Methods for both anisotropic and quasi-isotropic laminates are disclosed.

  17. Aplicación de técnicas UAVs en Agriculutura: Documentación geométrica y teledetección de viñedos a partir a partir de imágenes satelitales e imágenes multiespectrales de UAVS

    OpenAIRE

    López de Herrera, Juan

    2016-01-01

    Mostramos un análisis mediante una doble fuente de imágenes para la caracterización del paisaje. Por una parte imágenes de Satélite Sentinel 2 y por otra de UAV. Analizamos y comparamos las Ortoimágenes de satelitales y UAV comparando los resultados de los índices de vegetación en función del estado vegetativo de las viñas. Los UAV son más precisos y mejores para la agricultura de precisión. Los satélites para el análisis de grandes extensiones.

  18. An approximate method of analysis for notched unidirectional composites

    Science.gov (United States)

    Zweben, C.

    1974-01-01

    An approximate method is proposed for the analysis of unidirectional, filamentary composite materials having slit notches perpendicular to the fibers and subjected to tension parallel to the fibers. The approach is based on an engineering model which incorporates important effects of material heterogeneity by considering average extensional stresses in the fibers and average shear stresses in the matrix. Effects of interfacial failure and matrix plasticity at the root of the notch are considered. Predictions of the analysis are in reasonably good agreement with previous analytical models and experimental data for graphite/epoxy.

  19. Research progress on structural ore-controlling of Xinjiang Baiyanghe uranium-polymetallic deposit

    International Nuclear Information System (INIS)

    Wang Mou; Wang Guo; Zhang Xiaojun

    2014-01-01

    This article mainly starts from the tectonics of Baiyanghe uranium-polymetallic deposit, which control the ore-mineralization distribution. Elaborate the research progress by analysising the characteristics and divising the stage of ore-controlling structures. which divided into contact zone structure and fracture structure, including complex contact zone and extensional double tectonic superimposition which control the output of main ore-body. According to the tectonic activities order. the ore-controlling structure can be mainly divided into three stage activities, metallogenic before, mineralization and metallogenic period after. (authors)

  20. Wadi Tharthar. Samarra, Irak

    Directory of Open Access Journals (Sweden)

    Editorial, Equipo

    1959-02-01

    Full Text Available De tiempo inmemorial son conocidas las devastadoras inundaciones y ruina que las grandes avenidas del río Tigris causan periódicamente en las partes llanas que atraviesa este río entre Samarra y Baghdad, asolando grandes extensiones de terrenos fértiles explotados agrícolamente. La Administración nacional iraquí no podía permitir una continuación prolongada de este proceso cíclico de inundaciones y accidentes.

  1. Mechanism of Polymer Drag Reduction Using a Low-Dimensional Model

    Science.gov (United States)

    Roy, Anshuman; Morozov, Alexander; van Saarloos, Wim; Larson, Ronald G.

    2006-12-01

    Using a retarded-motion expansion to describe the polymer stress, we derive a low-dimensional model to understand the effects of polymer elasticity on the self-sustaining process that maintains the coherent wavy streamwise vortical structures underlying wall-bounded turbulence. Our analysis shows that at small Weissenberg numbers, Wi, elasticity enhances the coherent structures. At higher Wi, however, polymer stresses suppress the streamwise vortices (rolls) by calming down the instability of the streaks that regenerates the rolls. We show that this behavior can be attributed to the nonmonotonic dependence of the biaxial extensional viscosity on Wi, and identify it as the key rheological property controlling drag reduction.

  2. Two Cenozoic tectonic events of N-S and E-W extension in the Lhasa Terrane: Evidence from geology and geochronology

    Science.gov (United States)

    Huang, Feng; Xu, Ji-Feng; Chen, Jian-Lin; Wu, Jian-Bin; Zeng, Yun-Chuan; Xiong, Qiu-Wei; Chen, Xue-Feng; Yu, Hong-Xia

    2016-02-01

    Cenozoic active structures in the Tibetan Plateau are mainly regional N-S trending extensional faults and grabens, and E-W trending extensional tracks that are related to the transition from syn- to post-collision between India and Asia. E-W trending tracks are parallel to the direction of Neo-Tethyan oceanic convergence and consist of extensional volcanic-sedimentary basins and magmatic dykes in the southern Lhasa Terrane, Tibet. N-S trending tracks comprise faults and grabens, which are widely developed in Tibet. It remains unknown how and when the geodynamic transition from E-W to N-S trending tectonic tracks occurred. This study describes both E-W and N-S trending tectonic tracks identified at Dazi area of southern Lhasa Terrane, where E-W trending mafic dykes intruded a granitoid and late-stage N-S trending felsic dykes cut across E-W trending mafic dykes. Zircons from four granitoid samples yield consistent crystallization ages of ca. 60 Ma and positive εHf(t) values (~+ 9). An altered dioritic vein, which cuts the mafic dykes, yields an age of ca. 53 Ma. These new dating results indicate that E-W trending dykes, which formed due to regional N-S extension, were emplaced between 60 and 53 Ma. In addition, two N-S trending monzonitic porphyritic dykes, which cut the mafic dykes, yield U-Pb zircon ages of ca. 17 Ma with moderate positive εHf(t) values (+ 3 to + 9.6), as well as a NNE-SSW trending quartz monzonitic dyke, which cuts all other types of dykes, yields U-Pb ages of ca. 13 Ma. This suggests that E-W extension took place between 17 and 13 Ma. These results, in combination with existing age data for Gangdese granitoids and mafic magmatism, indicate the occurrence of two major extensional events at 60-53 Ma and 17-13 Ma. In turn, this implies that the transition from E-W to N-S trending tectonic and the onset of E-W extension occurred at ca. 17 Ma or slightly earlier. Paleocene granitoids have geochemical characteristics that are indicative of both

  3. Black Holes, Geons, and Singularities in Metric-Affine Gravity

    OpenAIRE

    Sanchez-Puente, Antonio

    2017-01-01

    Uno de los problemas abiertos en la descripción de la gravedad es la existencia de singularidades. Las geometrías singulares se caracterizan por geodésicas incompletas, lo que físicamente se corresponde con observadores que desaparecen del espacio-tiempo, o que aparecen de la nada. Múltiples extensiones de la Relatividad General tratan de resolver este problema de algún modo. Por ello, en esta tesis estudio modificaciones al Lagrangiano de Relatividad General, tales como gravedad cuadráti...

  4. Internet Sexualities

    Science.gov (United States)

    Döring, Nicola

    The term “internet sexuality” (or OSA, online sexual activities) refers to sexual-related content and activities observable on the internet (cf. Adams, Oye, & Parker, 2003; Cooper, McLoughlin, & Campbell, 2000; Leiblum & Döring, 2002). It designates a variety of sexual phenomena (e.g., pornography, sex education, sexual contacts) related to a wide spectrum of online services and applications (e.g., websites, online chat rooms, peer-to-peer networks). If an even broader range of computer networks - such as the Usenet or bulletin board systems - is included in this extensional definition, one speaks of “online sexuality” or “cybersexuality.”

  5. Orientational ordering in sheared inelastic dumbbells.

    Science.gov (United States)

    Reddy, K Anki; Kumaran, V; Talbot, J

    2009-09-01

    Using even driven simulations, we show that homogeneously sheared inelastic dumbbells in two dimensions are randomly orientated in the limit of low density. As the packing fraction is increased, particles first tend to orient along the extensional axis, and then as the packing fraction is further increased, the alignment shifts closer to the flow axis. The orientational order parameter displays a continuous increase with packing fraction and does not appear to exhibit a universal scaling with elongation. Except at the highest packing fractions, the orientational distribution function can be reconstructed with only the first coefficient of the Fourier expansion.

  6. Two decades of Indian research on Ninetyeast Ridge reveal how seafloor spreading and mantle plume activities have shaped the eastern Indian Ocean.

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.

    is widespread and often complex. The style of strike–slip faulting observed over the northern part of the Ninetyeast Ridge is a clear manifes- tation of India–Australia deforma- tion and it differs from the style of extensional faulting in the southern part... of the ridge which was ascribed due to Capricorn–Australia defor- mation. The findings further indicate that structural style of deformations varies on either side of the Ninety- east Ridge, implying that the ridge structure is currently acting as a...

  7. Presentación de un caso de Pénfigo Vulgar

    OpenAIRE

    Zully Ballesteros Zárate; Julio Cesar Mantilla Hernández; Álvaro Sanabria Naranjo

    2012-01-01

    El pénfigo es una enfermedad vesículo-ampollosa autoinmune de la piel y mucosas, que puede comprometer grandes extensiones; los tipos vulgar y foliáceo son los más frecuentes, con diferencias inmunopatológicas entre ellas. El pénfigo es tratado con corticoides y Azatioprina pero en los últimos años se incluyeron nuevos medicamentos como inmunoglobulinas, Rituximab (anticuerpo monoclonal quimérico anti-CD20) entre otros, Mostramos un caso de pénfigo hiperpigmentado atípico, y revisamos el tema...

  8. La deserción escolar en la educación rural, Municipio de El Fuerte, Sinaloa.

    OpenAIRE

    Ruíz Ramírez, Rosalva

    2014-01-01

    El objetivo de la investigación fue analizar las causas y consecuencias -de tipo personal, económico y social- que provocan la deserción escolar de estudiantes de preparatoria, caso Universidad Autónoma de Sinaloa (UAS) en el municipio El Fuerte. La pesquisa se efectuó en la Unidad Académica San Blas y sus extensiones La Constancia y Las Higueras de Los Natoches en 2013. Se trabajó con metodología de enfoque mixto analizando datos cualitativos y cuantitativos a través de observación directa, ...

  9. Abnormal interruption of water flow from an artesian well prior to 2008 Wenchuan earthquake

    Directory of Open Access Journals (Sweden)

    Liu Chenglong

    2011-05-01

    Full Text Available Water flow from an artesian well stopped on December 17, 2007 but recovered when the Wenchuan Ms 8.0 earthquake occurred on May 12, 2008. This well is located 90 km south of the epicenter in an extensional tectonic setting, where similar changes of water level and resistivity were observed at two other nearby sites. Our investigation suggests that this phenomenon was not caused by environmental disturbances, such as drought or borehole-drilling activity, but might be a precursor to the earthquake.

  10. Colonización de taludes artificiales por medio de la vegetación natural

    OpenAIRE

    Alfaya Arias, Valentín

    2012-01-01

    La construcción de modernas vías de transporte, y, por extensión, de grandes infraestructuras de carácter lineal, conlleva ingentes movimientos de tierra que afectan a vastas extensiones de hábitats naturales. En la actualidad, la tecnología y maquinaria disponibles permiten abordar obras de ingeniería de una envergadura impensable hace tan solo un par de décadas, pero que al mismo tiempo son el origen de impactos ambientales antes desconocidos, en no pocas ocasiones severos o incluso irrever...

  11. 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.

    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...... from published wide-angle seismic studies in the area. The evolution of the East Greenland and Norwegian Caledonides at the conjugated margins may be closely connected. A comparison with a similar study in Norway will give insight to what extend topography, crustal and upper mantle structures on both...

  12. On the lamb wave propagation in anisotropic laminated composite plates

    International Nuclear Information System (INIS)

    Park, Soo Keun; Jeong, Hyun Jo; Kim, Moon Saeng

    1998-01-01

    This paper examines the propagation of Lamb (or plate) waves in anisotropic laminated composite plates. The dispersion relations are explicitly derived using the classical plate theory (CLT), the first-order shear deformation theory (FSDT) and the exact solution (ES), Attention is paid to the lowest antisymmetric (flexural) and lowest symmetric(extensional) modes in the low frequency, long wavelength limit. Different values of shear correction factor were tested in FSDT and comparisons between flexural wave dispersion curves were made with exact results to asses the range of validity of approximate plate theories in the frequency domain.

  13. Is The Chapala-Oaxaca Fault The Souhtern Boundary of the Michoacan-Guanajuato Volcanic Field As inferrred From Magnetic data?

    Science.gov (United States)

    Rosas-Elguera, J.; Lopez-Loera, H.; Fregoso, E.; Flores, R. M., Sr.; Peña, L.

    2016-12-01

    On the basis of previous structural and new geophysical data, we propose that: (1) the continental boundaries of the Michoacan block are early structures reactivated since the Pliocene to Quaternary contributing to development of volcanism along it and (2) previously, Rosas-Elguera et al. (1996) proposed that Pliocene-Quaternary extensional faulting at the western edge of Michoacan block is a basement-controlled intraplate deformation related to plate boundary forces rather than to active continental rifting. Here we propose the NW boundary is formed by three segments: the Cotija half-graben, the Paricutin zone and the Jorullo zone.

  14. McLuhan y la radio. Del fonógrafo y la radiotelegrafía a Spotify

    OpenAIRE

    Octavio Islas

    2015-01-01

    En 2014 se cumplieron 50 años de la publicación de la primera edición del libro Understanding media: The extensions of man (1964) -en castellano: Comprender los medios de comunicación. Las extensiones del hombre-, cuarto libro de Herbert Marshall McLuhan (1911-1980), pensador de enorme trascendencia en la imaginación comunicológica contemporánea. Es posible afirmar que McLuhan inauguró formalmente el estudio de los medios de comunicación electrónicos, anticipando, además, el estudio de los me...

  15. Measuring Cell Mechanics By Optical Alignment Compression Cytometry

    Science.gov (United States)

    Roth, Kevin B.; Eggleton, Charles D.; Neeves, Keith B.; Marr, David W. M.

    2013-01-01

    To address the need for a high throughput, non-destructive technique for measuring individual cell mechanical properties, we have developed optical alignment compression (OAC) cytometry. OAC combines hydrodynamic drag in an extensional flow microfluidic device with optical forces created with an inexpensive diode laser to induce measurable deformations between compressed cells. In this, a low-intensity linear optical trap aligns incoming cells with the flow stagnation point allowing hydrodynamic drag to induce deformation during cell-cell interaction. With this novel approach, we measure cell mechanical properties with a throughput that improves significantly on current non-destructive individual cell testing methods. PMID:23440063

  16. Little Shop of Horrors: Rheology of the Mucilage of Drosera sp., a Carnivorous Plant

    Science.gov (United States)

    Erni, Philipp; Varagnat, Matthieu; McKinley, Gareth H.

    2008-07-01

    Drosera sp. (`sundew') are carnivorous plants; they capture insects using tiny drops of mucilage secreted by stalked glands on their leaf laminae. Prey gets trapped by the sticky viscoelastic liquid, initiating a metabolic cascade on the leaf that eventually results in the insect being digested by the plant. The mucilage droplets typically are in the size range of tens of micrometers; at these extremely small sample sizes, complex fluids are usually not amenable to traditional rheometry. We discuss how microrheometric techniques, in particular capillary breakup extensional rheometry ("μ-caber"), can be used to test the nonlinear rheological properties of nanoliter volumes of such small-volume biopolymer samples.

  17. A Viscoelastic Deadly Fluid in Carnivorous Pitcher Plants

    Science.gov (United States)

    Gaume, Laurence; Forterre, Yoel

    2008-07-01

    We study the rheology of the digestive fluid secreted by the carnivorous pitcher plants Nepenthes rafflesiana and its role in the mechanism of insects trapping. Using a combination of physical measurements (surface tension, wetting properties, extensional and shear rheometry), insects bioessays and high-speed video, we show that the digestive fluid of Nepenthes rafflesiana is a highly viscoelastic fluid and that this property is crucial for the retention of insect in its trap. Trapping efficiency is shown to remain strong even when the fluid is highly diluted by water, as long as the elastic relaxation time of the fluid is higher than the typical time scale of insect movements (large Deborah numbers).

  18. Breve Panorama das Tendências Contemporâneas da Ficção Científica Brasileira

    Directory of Open Access Journals (Sweden)

    Rodolfo Rorato Londero

    2016-07-01

    Full Text Available Atualmente é possível reconhecer na produção brasileira de ficção científica três grandes tendências: 1 a história alternativa, incluindo a recentíssima febre steampunk; 2 a ficção cyberpunk; e 3 a ficção borderline (obras na fronteira entre a ficção científica e a ficção mainstream. As três tendências surgiram durante a Segunda Onda da Ficção Científica Brasileira, período que abrange o início dos anos 1980, sendo cada uma representada pelos autores Gerson Lodi-Ribeiro, Fausto Fawcett e Braulio Tavares, respectivamente. Além de comentar algumas obras recém-publicadas de novos e antigos autores inseridos nas três tendências – as histórias alternativas de Gerson Lodi-Ribeiro (Xochiquetzal, 2009 e de Roberto de Sousa Causo (Selva Brasil, 2010; as ficções cyberpunks de Fábio Fernandes (Os dias da peste, 2009 e de Richard Diegues (Cyber Brasiliana, 2010; e a ficção borderline de Luiz Bras (Paraíso líquido, 2010 –, o objetivo é relacioná-las ao pós-modernismo, demonstrando que este movimento artístico-cultural é o determinante em comum da atual produção: sendo assim, a história alternativa se aproxima da poética do pós-modernismo que Linda Hutcheon denomina “metaficção historiográfica”; a ficção cyberpunk, segundo Fredric Jameson, é a expressão literária máxima não apenas do pós-modernismo, mas também do capitalismo tardio; e a ficção borderline representa o enfraquecimento da distinção entre alta cultura e cultura de massa, também creditada ao pós-modernismo.

  19. TAXONOMÍA Y DISTRIBUCIÓN DE DIATOMEAS EPILÍTICAS REGISTRADAS POR PRIMERA VEZ EN COLOMBIA. I

    Directory of Open Access Journals (Sweden)

    SILVIA ESTELA SALA

    2015-06-01

    Full Text Available El presente trabajo se llevó a cabo en el marco del proyecto para elaborar un índice de calidad biológica para ríos de zonas bajas y de piedemonte del país basado en comunidades biológicas acuáticas, desarrollado en el Laboratorio de Biotecnología del Instituto Colombiano del Petróleo, cuyo objetivo es evaluar la calidad ecológica de los ríos de tierras bajas y de piedemonte dentro del área de influencia de Ecopetrol, a través de la implementación de un índice de calidad biológica utilizando diatomeas. Las 165 muestras analizadas hasta el momento provienen de muestras de perifiton de 83 sistemas lóticos de distintas regiones del país, de donde también se obtuvo información sobre temperatura del agua, pH, conductividad y oxígeno disuelto. El material fue estudiado con microscopio óptico y microscopio electrónico de barrido. Aquí reunimos 11 taxones de los cuales Achnanthidium macrocephalum(Hustedt Round & Bukhtiyarova, Cymbopleura zimmermannii Metzeltin & Lange-Bertalot, Chamaepinnularia brasiliana Metzeltin & Lange-Bertalot, Ch. brasilianopsis Metzeltin & Lange-Bertalot, Planothidium lagerheimii (Cleve Wetzel & Ector, Eunotioforma curvula (Hustedt Kociolek & Burliga, Gomphonema archaevibrio fo. cuneatum Metzeltin & Lange-Bertalot, Gomphonema capitatum Ehrenberg, Nitzschia clausii Hantzsch y N. filiformis var. conferta (Richter Lange-Bertalot se mencionan por primera vez para Colombia. Este es el primer registro del género Eunotioforma Kociolek & Burliga y por primera vez se describe e ilustra el género Chamaepinnularia Lange-Bertalot para el país. Además, analizamos la ultraestructura de Nitzschia dissipata(Kützing Grunow, ya mencionada para el país pero solo analizada con MO. A pesar de ser esta especie considerada cosmopolita citada en las floras de diferentes regiones del mundo, ha sido frecuentemente mal identificada, por lo que este análisis nos permitió confirmar la identidad de los materiales colombianos.

  20. Empirical relationships among triangular facet slope, facet height and slip rates along active normal faults from ASTER DEM data

    Science.gov (United States)

    Tsimi, Christina; Ganas, Athanassios

    2015-04-01

    ASTER DEM data (30-m pixel size) are used to derive empirical relationships between triangular facet attributes and slip rates along active normal faults. We sampled 232 triangular facets along 10 normal faults in Greece and Bulgaria that slip with rates from 0.1 mm/yr up to 1.3 mm/yr. The studied normal faults accumulate Quaternary tectonic strain in well-known extensional provinces, such as central Greece, Crete and SW Bulgaria. The normal fault footwalls analysed herein have been developed under similar long-term climatic conditions. It is suggested that two key geometrical features of the youngest generation of triangular facets (slope angle and height) can provide useful metrics to assess rates of deformation when seismological and geodetic data are lacking or not found in sufficient quantity to make reasonable assessments. Our derived empirical relation between slip rate and facet slope angle is: Y=0.057•X-1 where Y is fault slip rate (mm/yr) and X is facet slope angle (degrees), with an R² = 0.728. It is envisaged that our analysis may be helpful in assessing seismic hazard along normal faults with similar facet characteristics in other extensional settings. Note: This research was funded by The Rapid Analysis and Spatialisation Of Risk (RASOR) project http://www.rasor-project.eu/