Sample records for vent field juan

  1. Hydrothermal Vents of Juan de Fuca Ridge (United States)

    Stark, Joyce

    As a member of REVEL (Research and Education: Volcanoes, Exploration and Life), I had an opportunity to participant in a scientific research cruise focused on the active volcanoes along the Juan de Fuca Ridge, the submarine spreading center off the Washington- Oregon-Canada coast. REVEL was sponsored by the National Science Foundation, University of Washington, Pennsylvania State University and the American Museum of Natural History. We studied the geological, chemical and biological processes associated with active hydrothermal systems and my research focused on the biological communities of the sulfide structures. We worked on board the Woods Hole Oceanographic Institution Vessel, R/V Atlantis and the submersible ALVIN was used to sample the "Black Smokers". As a member of the scientific party, I participated in collection and sorting of biological specimens from the vent communities, attended lectures by scientists, contributed to the cruise log website, maintained a journal and developed my own research project. It was my responsibility to bring this cutting-edge research back to the classroom.

  2. Heat flux measured acoustically at Grotto Vent, a hydrothermal vent cluster on the Endeavour Segment, Juan de Fuca Ridge (United States)

    Xu, G.; Jackson, D. R.; Bemis, K. G.; Rona, P. A.


    Over the past several decades, quantifying the heat output has been a unanimous focus of studies at hydrothermal vent fields discovered around the global ocean. Despite their importance, direct measurements of hydrothermal heat flux are very limited due to the remoteness of most vent sites and the complexity of hydrothermal venting. Moreover, almost all the heat flux measurements made to date are snapshots and provide little information on the temporal variation that is expected from the dynamic nature of a hydrothermal system. The Cabled Observatory Vent Imaging Sonar (COVIS, is currently connected to the Endeavour node of the NEPTUNE Canada observatory network ( to monitor the hydrothermal plumes issuing from a vent cluster (Grotto) on the Endeavour Segment of the Juan de Fuca Ridge. COVIS is acquiring a long-term (20-months to date) time series of the vertical flow rate and volume flux of the hydrothermal plume above Grotto through the Doppler analysis of the acoustic backscatter data (Xu et al., 2013). We then estimate the plume heat flux from vertical flow rate and volume flux using our newly developed inverse method. In this presentation, we will briefly summarize the derivation of the inverse method and present the heat-flux time series obtained consequently with uncertainty quantification. In addition, we compare our heat-flux estimates with the one estimated from the plume in-situ temperatures measured using a Remotely Operative Vehicle (ROV) in 2012. Such comparison sheds light on the uncertainty of our heat flux estimation. Xu, G., Jackson, D., Bemis, K., and Rona, P., 2013, Observations of the volume flux of a seafloor hydrothermal plume using an acoustic imaging sonar, Geochemistry, Geophysics Geosystems, 2013 (in press).

  3. Activity and abundance of denitrifying bacteria in the subsurface biosphere of diffuse hydrothermal vents of the Juan de Fuca Ridge (United States)

    Bourbonnais, A.; Juniper, S. K.; Butterfield, D. A.; Devol, A. H.; Kuypers, M. M. M.; Lavik, G.; Hallam, S. J.; Wenk, C. B.; Chang, B. X.; Murdock, S. A.; Lehmann, M. F.


    Little is known about fixed nitrogen (N) transformation and elimination at diffuse hydrothermal vents where anoxic fluids are mixed with oxygenated crustal seawater prior to discharge. Oceanic N sinks that remove bio-available N ultimately affect chemosynthetic primary productivity in these ecosystems. Using 15N paired isotope techniques, we determined potential rates of fixed N loss pathways (denitrification, anammox) and dissimilatory nitrate reduction to ammonium (DNRA) in sulfidic hydrothermal vent fluids discharging from the subsurface at several sites at Axial Volcano and the Endeavour Segment on the Juan de Fuca Ridge. We also measured physico-chemical parameters (i.e., temperature, pH, nutrients, H2S and N2O concentrations) as well as the biodiversity and abundance of chemolithoautotrophic nitrate-reducing, sulfur-oxidizing γ-proteobacteria (SUP05 cluster) using sequence analysis of amplified small subunit ribosomal RNA (16S rRNA) genes in combination with taxon-specific quantitative polymerase chain reaction (qPCR) assays. Denitrification was the dominant N loss pathway in the subsurface biosphere of the Juan de Fuca Ridge, with rates of up to ~1000 nmol N l-1 day-1. In comparison, anammox rates were always small fraction of the total marine N loss (~275 to > 400 Tg N yr-1).

  4. Temporal and spatial variation in temperature experienced by macrofauna at Main Endeavour hydrothermal vent field (United States)

    Lee, Raymond W.; Robert, Katleen; Matabos, Marjolaine; Bates, Amanda E.; Juniper, S. Kim


    A significant focus of hydrothermal vent ecological studies has been to understand how species cope with various stressors through physiological tolerance and biochemical resistance. Yet, the environmental conditions experienced by vent species have not been well characterized. This objective requires continuous observations over time intervals that can capture environmental variability at scales that are relevant to animals. We used autonomous temperature logger arrays (four roughly parallel linear arrays of 12 loggers spaced every 10-12 cm) to study spatial and temporal variations in the thermal regime experienced by hydrothermal vent macrofauna at a diffuse flow vent. Hourly temperatures were recorded over eight months from 2010 to 2011 at Grotto vent in the Main Endeavour vent field on the Juan de Fuca Ridge, a focus area of the Ocean Networks Canada cabled observatory. The conspicuous animal assemblages in video footage contained Ridgeia piscesae tubeworms, gastropods (primarily Lepetodrilus fucensis), and polychaetes (polynoid scaleworms and the palm worm Paralvinella palmiformis). Two dimensional spatial gradients in temperature were generally stable over the deployment period. The average temperature recorded by all arrays, and in some individual loggers, revealed distinctive fluctuations in temperature that often corresponded with the tidal cycle. We postulate that this may be related to changes in bottom currents or fluctuations in vent discharge. A marked transient temperature increase lasting over a period of days was observed in April 2011. While the distributions and behavior of Juan de Fuca Ridge vent invertebrates may be partially constrained by environmental temperature and temperature tolerance, except for the one transient high-temperature event, observed fluid temperatures were generally similar to the thermal preferences for some species, and typically well below lethal temperatures for all species. Average temperatures of the four arrays

  5. Activity and abundance of denitrifying bacteria in the subsurface biosphere of diffuse hydrothermal vents of the Juan de Fuca Ridge

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    A. Bourbonnais


    Full Text Available Little is known about fixed nitrogen (N transformation and elimination at diffuse hydrothermal vents where anoxic fluids are mixed with oxygenated crustal seawater prior to discharge. Oceanic N sinks that remove bio-available N ultimately affect chemosynthetic primary productivity in these ecosystems. Using 15N paired isotope techniques, we determined potential rates of fixed N loss pathways (denitrification, anammox and dissimilatory nitrate reduction to ammonium (DNRA in sulfidic hydrothermal vent fluids discharging from the subsurface at several sites at Axial Volcano and the Endeavour Segment on the Juan de Fuca Ridge. We also measured physico-chemical parameters (i.e., temperature, pH, nutrients, H2S and N2O concentrations as well as the biodiversity and abundance of chemolithoautotrophic nitrate-reducing, sulfur-oxidizing γ-proteobacteria (SUP05 cluster using sequence analysis of amplified small subunit ribosomal RNA (16S rRNA genes in combination with taxon-specific quantitative polymerase chain reaction (qPCR assays. Denitrification was the dominant N loss pathway in the subsurface biosphere of the Juan de Fuca Ridge, with rates of up to ~1000 nmol N l−1 day−1. In comparison, anammox rates were always < 5 nmol N l−1 day−1 and below the detection limit at most of the sites. DNRA rates were up to ~150 nmol N l−1 day−1. These results suggest that bacterial denitrification out-competes anammox in sulfidic hydrothermal vent waters. Taxon-specific qPCR revealed that γ-proteobacteria of the SUP05 cluster sometimes dominated the microbial community (SUP05/total bacteria up to 38%. Significant correlations were found between fixed N loss (i.e., denitrification, anammox rates and in situ nitrate and dissolved inorganic nitrogen (DIN deficits in the fluids, indicating that DIN availability may ultimately regulate N loss in the subsurface

  6. Discovery of a black smoker vent field and vent fauna at the Arctic Mid-Ocean Ridge. (United States)

    Pedersen, Rolf B; Rapp, Hans Tore; Thorseth, Ingunn H; Lilley, Marvin D; Barriga, Fernando J A S; Baumberger, Tamara; Flesland, Kristin; Fonseca, Rita; Früh-Green, Gretchen L; Jorgensen, Steffen L


    The Arctic Mid-Ocean Ridge (AMOR) represents one of the most slow-spreading ridge systems on Earth. Previous attempts to locate hydrothermal vent fields and unravel the nature of venting, as well as the provenance of vent fauna at this northern and insular termination of the global ridge system, have been unsuccessful. Here, we report the first discovery of a black smoker vent field at the AMOR. The field is located on the crest of an axial volcanic ridge (AVR) and is associated with an unusually large hydrothermal deposit, which documents that extensive venting and long-lived hydrothermal systems exist at ultraslow-spreading ridges, despite their strongly reduced volcanic activity. The vent field hosts a distinct vent fauna that differs from the fauna to the south along the Mid-Atlantic Ridge. The novel vent fauna seems to have developed by local specialization and by migration of fauna from cold seeps and the Pacific.

  7. Dissolved gases in hydrothermal plumes from Artic vent fields


    Stensland, Anne


    Recent discoveries of active vent fields on slow and ultraslow spreading ridges have revealed that hydrothermal activity is more common than previously assumed. In the Norwegian-Greenland Sea, two such vent fields are found; the Jan Mayen vent fields (71°N and 6°E) and Loki`s Castle (73°30′N and 8°E). Both these systems are located on the ultraslow spreading Mohns Ridge, but they differ profoundly in the geochemical fluid and gas composition. This study presen...

  8. Biogenic iron oxyhydroxide formation at mid-ocean ridge hydrothermal vents: Juan de Fuca Ridge

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    Toner, Brandy M.; Santelli, Cara M.; Marcus, Matthew A.; Wirth, Richard; Chan, Clara S.; McCollom, Thomas; Bach, Wolfgang; Edwards, Katrina J.


    Here we examine Fe speciation within Fe-encrusted biofilms formed during 2-month seafloor incubations of sulfide mineral assemblages at the Main Endeavor Segment of the Juan de Fuca Ridge. The biofilms were distributed heterogeneously across the surface of the incubated sulfide and composed primarily of particles with a twisted stalk morphology resembling those produced by some aerobic Fe-oxidizing microorganisms. Our objectives were to determine the form of biofilm-associated Fe, and identify the sulfide minerals associated with microbial growth. We used micro-focused synchrotron-radiation X-ray fluorescence mapping (mu XRF), X-ray absorption spectroscopy (mu EXAFS), and X-ray diffraction (mu XRD) in conjunction with focused ion beam (FIB) sectioning, and highresolution transmission electron microscopy (HRTEM). The chemical and mineralogical composition of an Fe-encrusted biofilm was queried at different spatial scales, and the spatial relationship between primary sulfide and secondary oxyhydroxide minerals was resolved. The Fe-encrusted biofilms formed preferentially at pyrrhotite-rich (Fe1-xS, 0<_ x<_ 0.2) regions of the incubated chimney sulfide. At the nanometer spatial scale, particles within the biofilm exhibiting lattice fringing and diffraction patterns consistent with 2-line ferrihydrite were identified infrequently. At the micron spatial scale, Fe mu EXAFS spectroscopy and mu XRD measurements indicate that the dominant form of biofilm Fe is a short-range ordered Fe oxyhydroxide characterized by pervasive edge-sharing Fe-O6 octahedral linkages. Double corner-sharing Fe-O6 linkages, which are common to Fe oxyhydroxide mineral structures of 2-line ferrihydrite, 6-line ferrihydrite, and goethite, were not detected in the biogenic iron oxyhydroxide (BIO). The suspended development of the BIO mineral structure is consistent with Fe(III) hydrolysis and polymerization in the presence of high concentrations of Fe-complexing ligands. We hypothesize that

  9. Geology, sulfide geochemistry and supercritical venting at the Beebe Hydrothermal Vent Field, Cayman Trough (United States)

    Webber, Alexander P.; Roberts, Stephen; Murton, Bramley J.; Hodgkinson, Matthew R. S.


    The Beebe Vent Field (BVF) is the world's deepest known hydrothermal system, at 4960 m below sea level. Located on the Mid-Cayman Spreading Centre, Caribbean, the BVF hosts high temperature (˜401°C) "black smoker" vents that build Cu, Zn and Au-rich sulfide mounds and chimneys. The BVF is highly gold-rich, with Au values up to 93 ppm and an average Au:Ag ratio of 0.15. Gold precipitation is directly associated with diffuse flow through "beehive" chimneys. Significant mass-wasting of sulfide material at the BVF, accompanied by changes in metal content, results in metaliferous talus and sediment deposits. Situated on very thin (2-3 km thick) oceanic crust, at an ultraslow spreading centre, the hydrothermal system circulates fluids to a depth of ˜1.8 km in a basement that is likely to include a mixture of both mafic and ultramafic lithologies. We suggest hydrothermal interaction with chalcophile-bearing sulfides in the mantle rocks, together with precipitation of Au in beehive chimney structures, has resulted in the formation of a Au-rich volcanogenic massive sulfide (VMS) deposit. With its spatial distribution of deposit materials and metal contents, the BVF represents a modern day analogue for basalt hosted, Au-rich VMS systems.

  10. Co-registered Geochemistry and Metatranscriptomics Reveal Unexpected Distributions of Microbial Activity within a Hydrothermal Vent Field

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    Heather C. Olins


    Full Text Available Despite years of research into microbial activity at diffuse flow hydrothermal vents, the extent of microbial niche diversity in these settings is not known. To better understand the relationship between microbial activity and the associated physical and geochemical conditions, we obtained co-registered metatranscriptomic and geochemical data from a variety of different fluid regimes within the ASHES vent field on the Juan de Fuca Ridge. Microbial activity in the majority of the cool and warm fluids sampled was dominated by a population of Gammaproteobacteria (likely sulfur oxidizers that appear to thrive in a variety of chemically distinct fluids. Only the warmest, most hydrothermally-influenced flows were dominated by active populations of canonically vent-endemic Epsilonproteobacteria. These data suggest that the Gammaproteobacteria collected during this study may be generalists, capable of thriving over a broader range of geochemical conditions than the Epsilonproteobacteria. Notably, the apparent metabolic activity of the Gammaproteobacteria—particularly carbon fixation—in the seawater found between discrete fluid flows (the intra-field water suggests that this area within the Axial caldera is a highly productive, and previously overlooked, habitat. By extension, our findings suggest that analogous, diffuse flow fields may be similarly productive and thus constitute a very important and underappreciated aspect of deep-sea biogeochemical cycling that is occurring at the global scale.

  11. Description and morphology of the “Juan de Fuca vent mussel”, Benthomodiolus erebus sp. n. (Bivalvia, Mytilidae, Bathymodiolinae: “Phylogenetically basal but morphologically advanced”

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    P. Graham Oliver


    Full Text Available The Juan de Fuca vent mussel first found in 1990 is formally described as Benthomodiolus erebus sp. n. Comparisons are made with the three other species previously assigned to Benthomodiolus namely B. lignocola, B. geikotsucola and B. abyssicola. The anatomies of all four species are examined and are shown to share the arrangement of pedal and byssus musculature, having largely un-fused mantle margins and a hind gut with a very short loop. The ctenidia were examined using both light and scanning electron microscopy. B. erebus and B. geikotsucola were found to have lamellar filaments with extensive abfrontal expansion and fusion of the ascending and descending arms. In this there is similarity with Bathymodiolus. B. lignocola and B. abyssicola were found to have linear filaments with narrow abfrontal surfaces with little fusion. All four species were shown to have the abfrontal surfaces covered by polygonal cushions of microvilli although these were much less apparent in B. lignocola and B. abyssicola. Although Benthomodiolus was shown by a number of previous studies, using molecular data alone, to be phylogenetically basal to all other Bathymodiolinae the anatomy is highly adapted for chemosymbiosis. Species of Benthomodiolus are found on wood-falls, whale-falls and vent sites and thus mirror the habits of the Bathymodiolus/Idas clade.

  12. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre (United States)

    Connelly, Douglas P.; Copley, Jonathan T.; Murton, Bramley J.; Stansfield, Kate; Tyler, Paul A.; German, Christopher R.; Van Dover, Cindy L.; Amon, Diva; Furlong, Maaten; Grindlay, Nancy; Hayman, Nicholas; Hühnerbach, Veit; Judge, Maria; Le Bas, Tim; McPhail, Stephen; Meier, Alexandra; Nakamura, Ko-ichi; Nye, Verity; Pebody, Miles; Pedersen, Rolf B.; Plouviez, Sophie; Sands, Carla; Searle, Roger C.; Stevenson, Peter; Taws, Sarah; Wilcox, Sally


    The Mid-Cayman spreading centre is an ultraslow-spreading ridge in the Caribbean Sea. Its extreme depth and geographic isolation from other mid-ocean ridges offer insights into the effects of pressure on hydrothermal venting, and the biogeography of vent fauna. Here we report the discovery of two hydrothermal vent fields on the Mid-Cayman spreading centre. The Von Damm Vent Field is located on the upper slopes of an oceanic core complex at a depth of 2,300 m. High-temperature venting in this off-axis setting suggests that the global incidence of vent fields may be underestimated. At a depth of 4,960 m on the Mid-Cayman spreading centre axis, the Beebe Vent Field emits copper-enriched fluids and a buoyant plume that rises 1,100 m, consistent with >400 °C venting from the world's deepest known hydrothermal system. At both sites, a new morphospecies of alvinocaridid shrimp dominates faunal assemblages, which exhibit similarities to those of Mid-Atlantic vents. PMID:22233630

  13. Effect of depth and vent fluid composition on the carbon sources at two neighboring deep-sea hydrothermal vent fields (Mid-Cayman Rise) (United States)

    Bennett, Sarah A.; Dover, Cindy Van; Breier, John A.; Coleman, Max


    In this study, we have used stable isotopes of megafauna, microbial mats and particulate organic matter to examine the effect of depth and vent fluid composition on the carbon sources at two proximal, chemically distinct hydrothermal vent fields along the Mid-Cayman Rise. The basalt hosted Piccard vent field (4980 m) is twice as deep as the ultramafic hosted Von Damm vent field (2300 m) and has very different faunal assemblages. Of particular note is the presence of seep-associated fauna, Escarpia and Lamellibrachia tubeworms, at the Von Damm vent field. We identify a greater range of carbon sources and a suggestion of increased photosynthetic inputs to the Von Damm vent field compared to Piccard vent field. Rimicaris hybisae shrimp are the only abundant species shared between the two vent fields with δ13C values ranging between -22.7 and -10.1‰. Higher concentrations of hydrogen sulfide in the vent fluids at Piccard is proposed to be responsible for varying the relative contributions of the carbon fixation cycles used by their epibionts. Seep-associated fauna at Von Damm rely on elevated, thermogenic hydrocarbon content of the vent fluids for their carbon source (δ13C values ranging from -21.3 to 11.6‰). They also derive energy from hydrogen sulfide formed by the microbial reduction of sulfide (δ34S values ranging from -10.2 to -6.9‰). The tubeworms have very short roots (buried at most a centimeter into rubble), suggesting that microbial sulfate reduction must be occurring either in the shallow subsurface and/or in the anterior part of the tube. Overall, megafauna at Von Damm vent field appear to have a smaller food chain length (smaller δ15N range) but a greater breadth of trophic resources compared to the megafauna at the Piccard vent field.

  14. Bioaccumulation of Hg, Cu, and Zn in the Azores Triple Junction hydrothermal vent field food chains


    Colaco, Ana; Bustamante, Paco; Fouquet, Yves; Sarradin, Pierre-Marie; Serrão-Santos, R.


    International audience; In this work, mercury (Hg), copper (Cu) and zinc (Zn) concentrations and tissue distribution are determined in seven benthic invertebrates species (the key species) from the Mid Atlantic Ridge (MAR) hydrothermal vent fields. The samples were collected from three hydrothermal vent fields - Menez Gwen, 840 m; Lucky Strike, 1700 m and Rainbow, 2300 m - near the Azores Triple Junction. These fields are characterized by different depths, geological context and chemical comp...

  15. Antioxidant systems and lipid peroxidation in Bathymodiolus azoricus from Mid-Atlantic Ridge hydrothermal vent fields. (United States)

    Bebianno, M J; Company, R; Serafim, A; Camus, L; Cosson, R P; Fiala-Médoni, A


    Enzymatic defenses involved in protection from oxygen radical damage were determined in gills and mantle of Bathymodiolus azoricus collected from three contrasting Mid-Atlantic Ridge (MAR) hydrothermal vent fields (Menez-Gwen, Lucky Strike and Rainbow). The activities of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx) (total and Se-dependent), and levels of total oxyradical scavenging capacity (TOSC), metallothioneins (MT) and lipid peroxidation (LPO) were determined in B. azoricus tissues and the impact of metal concentrations on these antioxidant systems and lipid peroxidation assessed. SOD, CAT, TOSC, MTs and LPO levels were higher in B. azoricus gills while glutathione peroxidases (total and Se-dependent) were higher in the mantle, and with the exception of CAT, were of the same order of magnitude as in other molluscs. TOSC levels from Menez-Gwen indicate that the vent environment at this site is less stressful and the formation of ROS in mussels is effectively counteracted by the antioxidant defense system. TOSC depletion indicates an elevated ROS production in molluscs at the other two vent sites. Cytosolic SOD, GPx and LPO were more relevant at Lucky Strike (Bairro Alto) where levels of essential (Cu and Zn) and toxic metals (Cd and Ag) were highest in the organisms. CAT activity and LPO were predominant at the Rainbow vent site, where an excess of Fe in mussel tissues and in vent fluids (the highest of all three vent sites) may have contributed to increased LPO. Therefore, three distinct pathways for antioxidant enzyme systems and LPO based on environmental metal speciation of MAR vent fields are proposed for Bathymodiolus gills. At Menez-Gwen, TOSC towards peroxyl and hydroxyl radicals and peroxynitrite are predominant, while at Lucky Strike cytosolic SOD activity and GPx are the main antioxidant mechanisms. Finally at Rainbow, catalase and lipid peroxidation are dominant, suggesting that resistance of mussels to metal toxicity at

  16. Field Testing of an Unvented Roof with Fibrous Insulation, Tiles, and Vapor Diffusion Venting

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    Ueno, K. [Building Science Corporation, Westford, MA (United States); Lstiburek, J. W. [Building Science Corporation, Westford, MA (United States)


    This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane. As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design.

  17. Field tests-low input, side-wall vented boiler

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    Litzke, W.L.; Butcher, T.A.; Celebi, Y. [Brookhaven National Lab., Upton, NY (United States)


    The Fan Atomized Burner (FAB) was developed at Brookhaven National Laboratory as part of the Oil Heat Combustion Equipment Technology Program to provide a practical low-firing rate technology leading to new, high efficiency oil-fired appliances. The development of the burner design and results of application testing have been presented in prior oil heat conferences over the past several years. This information is also summarized in a more comprehensive BNL report. The first field trial of a prototype unit was initiated during the 1994-95 heating season. This paper presents the results of the second year of testing, during the 1995-96 heating season. The field tests enable the demonstration of the reliability and performance of the FAB under practical, typical operating conditions. Another important objective of the field test was to demonstrate that the low input is adequate to satisfy the heating and hot water demands of the household. During the first field trial it was shown that at a maximum input rate of 0.4 gph (55,000 Btu/hr) the burner was able to heat a home with over 2,000 square feet of conditioned living space and provide adequate supply of domestic hot water for a family of six. The test is located in Long Island, NY.

  18. Volcanic field elongation, vent distribution and tectonic evolution of continental rift: The Main Ethiopian Rift example (United States)

    Mazzarini, Francesco; Le Corvec, Nicolas; Isola, Ilaria; Favalli, Massimiliano


    Magmatism and faulting operate in continental rifts and interact at a variety of scales, however their relationship is complex. The African rift, being the best example for both active continental rifting and magmatism, provides the ideal location to study the interplay between the two mechanisms. The Main Ethiopian Rift (MER), which connects the Afar depression in the north with the Turkana depression and Kenya Rift to the south, consists of two distinct systems of normal faults and its floor is scattered with volcanic fields formed by tens to several hundreds monogenetic, generally basaltic, small volcanoes and composite volcanoes and small calderas. The distribution of vents defines the overall shape of the volcanic field. Previous work has shown that the distribution of volcanic vents and the shape of a field are linked to its tectonic environment and its magmatic system. In order to distinguish the impact of each mechanism, we analyzed four volcanic fields located at the boundary between the central and northern MER, three of them (Debre Zeyit, Wonji and Kone) grew in the rift valley and one (Akaki) on the western rift shoulder. The elongation and shape of the fields were analyzed based on their vent distribution using the Principal Component Analysis (PCA), the Vent-to-Vent Distance (VVD), and the two dimensional symmetric Gaussian kernel density estimate methods. We extracted from these methods several parameters characterizing the spatial distribution of points (e.g., eccentricity (e), eigenvector index (evi), angular dispersion (Da)). These parameters allow to define at least three types of shape for volcanic fields: strong elongate (line and ellipse), bimodal/medium elongate (ellipse) and dispersed (circle) shapes. Applied to the natural example, these methods well differentiate each volcanic field. For example, the elongation of the field increases from shoulder to rift axis inversely to the angular dispersion. In addition, the results show that none of

  19. Mapping the Piccard Hydrothermal Field - The World's Deepest Known Vent Area (United States)

    Kinsey, J. C.; German, C. R.


    We report the recent mapping and exploration of the Piccard Hydrothermal Field on the Mid-Cayman Rise. Two previous expeditions in 2009 and 2010 led to the discovery of the site, which at 5000m hosts the world's deepest known vents. The site was mapped and explored in January 2012 and the Piccard Field was found to be larger than previously appreciated. The site includes 3 separate currently active hydrothermal mounts together with 4 additional extinct depo-centers. The 3 active centers are the Beebe Vents, Beebe Woods, and Beebe Sea sites. Beebe Vents is an active black smoker system with maximum temperatures of 400-403 degrees Celsius. Beebe Woods contains a set of tall beehive smokers with temperatures of approximately 353 degrees Celsius. Beebe Sea, the largest sulfide mound in the field, contains diffuse venting together with numerous extinct chimneys that indicate significant past active focused flow. Observations of the 4 extinct mounds indicate differences in their apparent ages based on the texture and morphology of the extinct sulfides at the summit of each mound. The entire field is located on top of an axial volcanic ridge with extrusive pillow mounds prominent. A major fault traverses the mound along its long axis, from Southwest to Northeast. Beebe Woods, Beebe Sea, and extinct Beebe mound D abut this fault directly with an apparent monotonic age progression from youngest (Beebe Woods) in the SW to relict mound 'D' in the NE. Similarly, the Beebe Vents site and mound is located at the SW limit of a parallel set of mounds, offset from the fault by approximately 100m, which also ages progressively through extinct Beebe Mounds 'E', 'F' and 'G'. The major fault that bisects the axial volcanic ridge at Piccard evidently serves as a controlling mechanism for the mounds abutting that fault however the mechanism for the second line of mounds remains to be determined. Bathymetry suggests the presence of a second, smaller fault which may serve as the control

  20. Field Testing of an Unvented Roof with Fibrous Insulation, Tiles and Vapor Diffusion Venting

    Energy Technology Data Exchange (ETDEWEB)

    Ueno, K. [Building Science Corporation, Westford, MA (United States); Lstiburek, J. W. [Building Science Corporation, Westford, MA (United States)


    This research is a test implementation of an unvented tile roof assembly in a hot-humid climate (Orlando, FL; Zone 2A), insulated with air permeable insulation (netted and blown fiberglass). Given the localized moisture accumulation and failures seen in previous unvented roof field work, it was theorized that a 'diffusion vent' (water vapor open, but air barrier 'closed') at the highest points in the roof assembly might allow for the wintertime release of moisture, to safe levels. The 'diffusion vent' is an open slot at the ridge and hips, covered with a water-resistant but vapor open (500+ perm) air barrier membrane. As a control comparison, one portion of the roof was constructed as a typical unvented roof (self-adhered membrane at ridge). The data collected to date indicate that the diffusion vent roof shows greater moisture safety than the conventional, unvented roof design. The unvented roof had extended winter periods of 95-100% RH, and wafer (wood surrogate RH sensor) measurements indicating possible condensation; high moisture levels were concentrated at the roof ridge. In contrast, the diffusion vent roofs had drier conditions, with most peak MCs (sheathing) below 20%. In the spring, as outdoor temperatures warmed, all roofs dried well into the safe range (10% MC or less). Some roof-wall interfaces showed moderately high MCs; this might be due to moisture accumulation at the highest point in the lower attic, and/or shading of the roof by the adjacent second story. Monitoring will be continued at least through spring 2016 (another winter and spring).

  1. Evolution of the Mothra Hydrothermal Field, Endeavour Segment of the Juan de Fuca Ridge (United States)

    Glickson, D.; Kelley, D. S.; Delaney, J.


    The Mothra Hydrothermal Field (MHF) is a 600 m long, high-temperature hydrothermal field. It is located 2.7 km south of the Main Endeavour Field at the southern end of the central Endeavour Segment. Mothra is the most areally extensive field along the Endeavour Segment, composed of six active sulfide clusters that are 40-200 m apart. Each cluster contains rare black smokers (venting up to 319°C), numerous diffusely venting chimneys, and abundant extinct chimneys and sulfide talus. From north to south, these clusters include Cauldron, Twin Peaks, Faulty Towers, Crab Basin, Cuchalainn, and Stonehenge. As part of the Endeavour Integrated Study Site (ISS), the MHF is a site of intensive interdisciplinary studies focused on linkages among geology, geochemistry, fluid chemistry, seismology, and microbiology. Axial valley geology at MHF is structurally complex, consisting of lightly fissured flows that abut the walls and surround a core of extensively fissured, collapsed terrain. Fissure abundance and distribution indicates that tectonism has been the dominant process controlling growth of the axial graben. Past magmatic activity is shown by the 200 m long chain of collapse basins between Crab Basin and Stonehenge, which may have held at least ~7500 m3 of lava. Assuming a flow thickness of 0.5 m, this amount of lava could cover over half the valley floor during a single volcanic event. At a local scale, MHF clusters vary in size, activity, and underlying geology. They range in size from 400-1600 m2 and consist of isolated chimneys and/or coalesced cockscomb arrays atop ramps of sulfide talus. In the northern part of the field, Cauldron, Twin Peaks, Faulty Towers, and Crab Basin are located near the western valley wall, bounded by basalt talus and a combination of collapsed sheet flows, intermixed lobate and sulfide, disrupted terrain, and isolated pillow ridges. The southern clusters, Cuchalainn and Stonehenge, are associated with collapse basins in the central valley

  2. Analysis of Upper Air, Ground and Remote Sensing Data for the Atlas Field Campaign in San Juan, Puerto Rico (United States)

    Gonzalez-Cruz, Jorge E.


    The general climate of the island of Puerto Rico is dominated by the easterly trade winds from the Atlantic Ocean, and during synoptically calm days by the topographic and local land surface characteristics [1]. The urban canopy of the metropolitan area of San Juan, capital city of the Island, may introduce a new microclimate that changes the characteristics of the low atmosphere and interacts with the other microclimates already present in the island. The primitive land cover and land use (LCLU) of the metropolitan area of San Juan was composed by broadleaf trees, moist soils, and very dense vegetation in general. The urban LCLU changes the balance for the mass, momentum and energy between the bottom boundary and the lower atmosphere, creating different climate conditions over urban and rural regions. Some of these differences are low relative humidity and high temperatures observed in urban areas when compared to rural areas. These in turn produces a convective circulation over the urban areas, a phenomenon compared to the sea and land breezes, commonly known as heat islands (UHI). Factors that contribute to the formation of the UHI are anthropogenic heat sources, aerosols from pollutants, fast water canalization due to the presence of buildings and streets, among others. The comparison between urban and rural climates is the most common approach to analyze the UHI. These contrasts are larger in clear and calm conditions and tend to disappear in cloudy and windy weather. The UHI was recognized in the early 1950 s as closed isotherms that separates the city from the general temperature field [2]. The impact of the urban LCLU in San Juan, Puerto Rico, was quantified calculating the difference between historical data sets for the air temperature over an identified urban area and a rural area dT(U-R). The analysis of the climatological data revealed that a UHI exists in the metropolitan area of San Juan, Puerto Rico. The data reveals a permanent urban heat island

  3. Geochemistry of hydrothermal vent fluids and its implications for subsurface processes at the active Longqi hydrothermal field, Southwest Indian Ridge (United States)

    Ji, Fuwu; Zhou, Huaiyang; Yang, Qunhui; Gao, Hang; Wang, Hu; Lilley, Marvin D.


    The Longqi hydrothermal field at 49.6°E on the Southwest Indian Ridge was the first active hydrothermal field found at a bare-rock ultra-slow spreading mid-ocean ridge. Here we report the chemistry of the hydrothermal fluids, for the first time, that were collected from the S zone and the M zone of the Longqi field by gas-tight isobaric samplers by the HOV "Jiaolong" diving cruise in January 2015. According to H2, CH4 and other chemical data of the vent fluid, we suggest that the basement rock at the Longqi field is dominantly mafic. This is consistent with the observation that the host rock of the active Longqi Hydrothermal field is dominated by extensively distributed basaltic rock. It was very interesting to detect simultaneously discharging brine and vapor caused by phase separation at vents DFF6, DFF20, and DFF5 respectively, in a distance of about 400 m. Based on the end-member fluid chemistry and distance between the vents, we propose that there is a single fluid source at the Longqi field. The fluid branches while rising to the seafloor, and two of the branches reach S zone and M zone and phase separate at similar conditions of about 28-30.2 MPa and 400.6-408.3 °C before they discharge from the vents. The end-member fluid compositions of these vents are comparable with or within the range of variation of known global seafloor hydrothermal fluid chemical data from fast, intermediate and slow spreading ridges, which confirms that the spreading rate is not the key factor that directly controls hydrothermal fluid chemistry. The composition of basement rock, water-rock interaction and phase separation are the major factors that control the composition of the vent fluids in the Longqi field.

  4. Virtual Vents: A Microbathymetrical Survey of the Niua South Hydrothermal Field, NE Lau Basin, Tonga (United States)

    Kwasnitschka, T.; Köser, K.; Duda, A.; Jamieson, J. W.; Boschen, R.; Gartman, A.; Hannington, M. D.; Funganitao, C.


    At a diameter of 200 m, the 1100 m deep Niua South hydrothermal field (NE Lau Basin) was studied in an interdisciplinary approach during the SOI funded Virtual Vents cruise in March of 2016. On the grounds of a previously generated 50 cm resolution AUV multi beam map, the projects backbone is formed by a fully color textured, 5 cm resolution photogrammetrical 3D model. Several hundred smaller and about 15 chimneys larger than 3 m were surveyed including their basal mounds and surrounding environment interconnecting to each other. This model was populated through exhaustive geological, biological and fluid sampling as well as continuous Eh measurements, forming the basis for highly detailed geological structural and biological studies resulting in 3D maps of the entire field. At a reasonable effort, such surveys form the basis for repetitive time series analysis and have the potential of a new standard in seafloor monitoring.

  5. Development and field application of a 6-bottle serial gas-tight fluid sampler for collecting seafloor cold seep and hydrothermal vent fluids with autonomous operation capability (United States)

    Wu, S.; Ding, K.; Yang, C.; Seyfried, W. E., Jr.; Tan, C.; Schaen, A. T.; Luhmann, A. J.


    A 6-bottle serial gas-tight sampler (so-called "six-shooter") was developed for application with deep-sea vent fluids. The new device is composed of a custom-made 6-channel valve manifold and six sampling bottles which are circularly distributed around the valve manifold. Each valve channel consists of a high-pressure titanium cartridge valve and a motor-driven actuator. A sampling snorkel is connected to the inlet of the manifold that delivers the incoming fluid to different bottles. Each sampling bottle has a 160 ml-volume chamber and an accumulator chamber inside where compressed nitrogen is used to maintain the sample at near in-situ pressure. An electronics chamber that is located at the center of the sampler is used to carry out all sampling operations, autonomously, if desired. The sampler is of a compact circular configuration with a diameter of 26 cm and a length of 54 cm. During the SVC cruise AT 26-12, the sampler was deployed by DSV2 Alvin at a cold seep site MC036 with a depth of 1090 m in the Gulf of Mexico. The sampler collected fluid samples automatically following the tidal cycle to monitor the potential impact of the tide cycle on the fluid chemistry of cold seep in a period of two day. During the cruise AT 26-17, the sampler was used with newly upgraded DSV2 Alvin three times at the hydrothermal vent sites along Axial Seamount and Main Endeavor Field on Juan de Fuca Ridge. During a 4-day deployment at Anemone diffuse site (Axial Caldera), the sampler was set to work in an autonomous mode to collect fluid samples according to the preset interval. During other dives, the sampler was manually controlled via ICL (Inductively Coupled Link) communication through the hull. Gas-tight fluid samples were collected from different hydrothermal vents with temperatures between 267 ℃ and 335 ℃ at the depth up to 2200 m. The field results indicate unique advantages of the design. It can be deployed in extended time period with remote operation or working

  6. Moytirra: Discovery of the first known deep-sea hydrothermal vent field on the slow-spreading Mid-Atlantic Ridge north of the Azores (United States)

    Wheeler, A. J.; Murton, B.; Copley, J.; Lim, A.; Carlsson, J.; Collins, P.; Dorschel, B.; Green, D.; Judge, M.; Nye, V.; Benzie, J.; Antoniacomi, A.; Coughlan, M.; Morris, K.


    Geological, biological, morphological, and hydrochemical data are presented for the newly discovered Moytirra vent field at 45oN. This is the only high temperature hydrothermal vent known between the Azores and Iceland, in the North Atlantic and is located on a slow to ultraslow-spreading mid-ocean ridge uniquely situated on the 300 m high fault scarp of the eastern axial wall, 3.5 km from the axial volcanic ridge crest. Furthermore, the Moytirra vent field is, unusually for tectonically controlled hydrothermal vents systems, basalt hosted and perched midway up on the median valley wall and presumably heated by an off-axis magma chamber. The Moytirra vent field consists of an alignment of four sites of venting, three actively emitting "black smoke," producing a complex of chimneys and beehive diffusers. The largest chimney is 18 m tall and vigorously venting. The vent fauna described here are the only ones documented for the North Atlantic (Azores to Reykjanes Ridge) and significantly expands our knowledge of North Atlantic biodiversity. The surfaces of the vent chimneys are occupied by aggregations of gastropods (Peltospira sp.) and populations of alvinocaridid shrimp (Mirocaris sp. with Rimicaris sp. also present). Other fauna present include bythograeid crabs (Segonzacia sp.) and zoarcid fish (Pachycara sp.), but bathymodiolin mussels and actinostolid anemones were not observed in the vent field. The discovery of the Moytirra vent field therefore expands the known latitudinal distributions of several vent-endemic genera in the north Atlantic, and reveals faunal affinities with vents south of the Azores rather than north of Iceland.

  7. New species of Ampharetidae (Annelida: Polychaeta) from the Arctic Loki Castle vent field (United States)

    Kongsrud, Jon A.; Eilertsen, Mari H.; Alvestad, Tom; Kongshavn, Katrine; Rapp, Hans Tore


    Ampharetid polychaetes adapted to live in chemosynthetic environments are well known from the deep Pacific and Atlantic Oceans, but to date no such species have been reported from the Arctic Ocean. Here, we describe two new species, Paramytha schanderi gen. et sp. nov. and Pavelius smileyi sp. nov., from the Arctic Loki's Castle vent field on the Knipovich Ridge north-east of the island of Jan Mayen. The new species are both tube-builders, and are found in a sedimentary area at the NE flank of the vent field, characterized by low-temperature venting and barite chimneys. The new genus, Paramytha, is characterized by a prostomium without lobes or glandular ridges, smooth buccal tentacles, four pairs of cirriform branchiae arranged as 2+1+1 without median gap dorsally on segments II-IV, absence of chaetae (paleae) on segment II, and absence of modified segments. P. smileyi sp. nov. is placed in the previously monotypic genus Pavelius, primarily based on the presence of a rounded prostomium without lobes and four pairs of branchiae arranged in a single transverse row without median gap dorsally on segment III. Pavelius smileyi sp. nov. differs from the type species, Pavelius uschakovi, in the number of thoracic and abdominal chaetigers, and the absence of chaetae (paleae) on segment II. The phylogenetic position of the two new species from Loki's Castle is further explored by use of molecular data. New sequences of mitochondrial (16S rDNA and cytochrome c oxidase subunit 1, COI) and nuclear (18S rDNA) markers have been produced for both species from Loki's Castle, as well as for specimens identified as Paramytha sp. from Setùbal Canyon off Portugal, and for the following species: Pavelius uschakovi, Grassleia cf. hydrothermalis, Sosane wireni, Amphicteis ninonae and Samythella neglecta. Results from phylogenetic analysis, including 22 species and 12 genera of Ampharetidae, recovered Paramytha gen. nov. as monophyletic with maximum support, and a close relationship

  8. Metagenomic Signatures of Microbial Communities in Deep-Sea Hydrothermal Sediments of Azores Vent Fields. (United States)

    Cerqueira, Teresa; Barroso, Cristina; Froufe, Hugo; Egas, Conceição; Bettencourt, Raul


    The organisms inhabiting the deep-seafloor are known to play a crucial role in global biogeochemical cycles. Chemolithoautotrophic prokaryotes, which produce biomass from single carbon molecules, constitute the primary source of nutrition for the higher organisms, being critical for the sustainability of food webs and overall life in the deep-sea hydrothermal ecosystems. The present study investigates the metabolic profiles of chemolithoautotrophs inhabiting the sediments of Menez Gwen and Rainbow deep-sea vent fields, in the Mid-Atlantic Ridge. Differences in the microbial community structure might be reflecting the distinct depth, geology, and distance from vent of the studied sediments. A metagenomic sequencing approach was conducted to characterize the microbiome of the deep-sea hydrothermal sediments and the relevant metabolic pathways used by microbes. Both Menez Gwen and Rainbow metagenomes contained a significant number of genes involved in carbon fixation, revealing the largely autotrophic communities thriving in both sites. Carbon fixation at Menez Gwen site was predicted to occur mainly via the reductive tricarboxylic acid cycle, likely reflecting the dominance of sulfur-oxidizing Epsilonproteobacteria at this site, while different autotrophic pathways were identified at Rainbow site, in particular the Calvin-Benson-Bassham cycle. Chemolithotrophy appeared to be primarily driven by the oxidation of reduced sulfur compounds, whether through the SOX-dependent pathway at Menez Gwen site or through reverse sulfate reduction at Rainbow site. Other energy-yielding processes, such as methane, nitrite, or ammonia oxidation, were also detected but presumably contributing less to chemolithoautotrophy. This work furthers our knowledge of the microbial ecology of deep-sea hydrothermal sediments and represents an important repository of novel genes with potential biotechnological interest.

  9. The Arctic Gakkel Vents (AGAVE) Expedition: Technology Development and the Search for Deep-Sea Hydrothermal Vent Fields Under the Arctic Ice Cap (United States)

    Reves-Sohn, R. A.; Singh, H.; Humphris, S.; Shank, T.; Jakuba, M.; Kunz, C.; Murphy, C.; Willis, C.


    Deep-sea hydrothermal fields on the Gakkel Ridge beneath the Arctic ice cap provide perhaps the best terrestrial analogue for volcanically-hosted chemosynthetic biological communities that may exist beneath the ice-covered ocean of Europa. In both cases the key enabling technologies are robotic (untethered) vehicles that can swim freely under the ice and the supporting hardware and software. The development of robotic technology for deep- sea research beneath ice-covered oceans thus has relevance to both polar oceanography and future astrobiological missions to Europa. These considerations motivated a technology development effort under the auspices of NASA's ASTEP program and NSF's Office of Polar Programs that culminated in the AGAVE expedition aboard the icebreaker Oden from July 1 - August 10, 2007. The scientific objective was to study hydrothermal processes on the Gakkel Ridge, which is a key target for global studies of deep-sea vent fields. We developed two new autonomous underwater vehicles (AUVs) for the project, and deployed them to search for vent fields beneath the ice. We conducted eight AUV missions (four to completion) during the 40-day long expedition, which also included ship-based bathymetric surveys, CTD/rosette water column surveys, and wireline photographic and sampling surveys of remote sections of the Gakkel Ridge. The AUV missions, which lasted 16 hours on average and achieved operational depths of 4200 meters, returned sensor data that showed clear evidence of hydrothermal venting, but for a combination of technical reasons and time constraints, the AUVs did not ultimately return images of deep-sea vent fields. Nevertheless we used our wireline system to obtain images and samples of extensive microbial mats that covered fresh volcanic surfaces on a newly discovered set of volcanoes. The microbes appear to be living in regions where reducing and slightly warm fluids are seeping through cracks in the fresh volcanic terrain. These discoveries

  10. A geologic and anthropogenic journey from the Precambrian to the new energy economy through the San Juan volcanic field (United States)

    Yager, Douglas B.; Burchell,; Johnson, Raymond H.


    The San Juan volcanic field comprises 25,000 km2 of intermediate composition mid-Tertiary volcanic rocks and dacitic to rhyolitic calderas including the San Juan–Uncompahgre and La Garita caldera-forming super-volcanoes. The region is famous for the geological, ecological, hydrological, archeological, and climatological diversity. These characteristics supported ancestral Puebloan populations. The area is also important for its mineral wealth that once fueled local economic vitality. Today, mitigating and/or investigating the impacts of mining and establishing the region as a climate base station are the focuses of ongoing research. Studies include advanced water treatment, the acid neutralizing capacity (ANC) of propylitic bedrock for use in mine-lands cleanup, and the use of soil amendments including biochar from beetle-kill pines. Biochar aids soil productivity and revegetation by incorporation into soils to improve moisture retention, reduce erosion, and support the natural terrestrial carbon sequestration (NTS) potential of volcanic soils to help offset atmospheric CO2 emissions. This field trip will examine the volcano-tectonic and cultural history of the San Juan volcanic field as well as its geologic structures, economic mineral deposits and impacts, recent mitigation measures, and associated climate research. Field trip stops will include a visit to (1) the Summitville Superfund site to explore quartz alunite-Au mineralization, and associated alteration and new water-quality mitigation strategies; (2) the historic Creede epithermal-polymetallic–vein district with remarkably preserved resurgent calderas, keystone-graben, and moat sediments; (3) the historic mining town of Silverton located in the nested San Juan–Silverton caldera complex that exhibits base-metal Au-Ag mineralization; and (4) the site of ANC and NTS studies. En route back to Denver, we will traverse Grand Mesa, a high NTS area with Neogene basalt-derived soils and will enjoy a soak

  11. Mercury concentrations in fish species caught at Mid-Atlantic Ridge hydrothermal vent fields

    National Research Council Canada - National Science Library

    I. Martins; V. Costa; F. M. Porteiro; A. Colaço; R. S. Santos


    Concentrations of total mercury and methyl mercury were determined in muscle and liver samples of 8 fish species caught at the Menez Gwen, Lucky Strike and Rainbow hydrothermal vents (Mid-Atlantic Ridge...

  12. Morphology of cone-fields in SW Elysium Planitia - Traces of hydrothermal venting on Mars? (United States)

    Lanz, J. K.; Saric, M. B.


    Introduction Small cone-shaped features with summit pits can be found in several regions on Mars; mainly in Isidis Planitia; Elysium Planitia; Amazonis Planitia; Acidalia Planitia; in the Cydonia Region; in Cerberus Planum; the Phlegra Montes and on several volcanic flanks. They vary greatly in size and morphology and have been compared to terrestrial features of various origins; namely (1) cinder cones (e.g. [1]), (2) tuff cones or tuff rings (e.g. [2]), (3) rootless cones (pseudocraters) (e.g. [3], [4]), (4) pingos (e.g. [5], [6]) and (5) mud volcanoes (e.g. [7]). They are often found near volcanic centers and large lava fields or cluster in regions where the volatile content of the Martian regolith was/is supposedly high. This has led to the assumption that (ground-) water or ground ice was a trigger or driving force of cone formation. They could therefore, be an important indicator of the history of water on the planet. We have studied an area in western Elysium Planitia, bordering the Aeolis Planum plateau, which exhibits a large number of pitted cones, ridges and dome-like structures. Their distribution and morphology differs strongly from pitted cones elsewhere in Elysium Planitia, which have mainly been interpreted as hydrovolcanic rootless cones, and from other regions on Mars. Based on our observations, we present an alternative model for cone formation in the study area that might hint towards hydrothermal processes in the Aeolis Planum region and possibly young igneous activity. Aeolis Planum Cones The Aeolis Planum pitted cones (referred to as APCs from now on) cluster along the southern edges of the broad shallow valley that borders the Aeolis Planum Formation (APF) to the north. Cones along the northern edges of the valley are rare and can only be found in association with APF remnants where they strongly resemble the cones in the south. Along the southern border the cone coverage is almost continuous, describing a narrow band approximately 2 to 3 km

  13. The formation of gold-rich seafloor sulfide deposits: Evidence from the Beebe hydrothermal vent field, Cayman Trough (United States)

    Webber, Alexander P.; Roberts, Stephen; Murton, Bramley J.; Mills, Rachel A.; Hodgkinson, Matthew R. S.


    The Beebe vent field (BVF) in the Cayman Trough has built an auriferous massive sulfide deposit on the ultraslow spreading mid-Cayman spreading center. The genesis of auriferous sulfide deposits at mid-ocean ridges is not fully understood, although there is a growing recognition that slow and ultraslow spreading centers are conducive to gold mineralization. Analysis of hydrothermal precipitates from the BVF indicates that the highest gold contents are present within "beehive diffusers," which have developed a highly porous pyrrhotite framework. The beehive structure allows vent fluids to effuse slowly while allowing ingress of seawater to cool the fluid. The prevalence of pyrrhotite in the beehive samples, lack of sulfates, association between pyrrhotite and gold grains, and results of thermodynamic modeling suggest gold precipitation occurred under highly reduced conditions even during mixing with seawater. In contrast, high-temperature chimneys, with a single orifice, maintain high temperatures to the primary vent orifice and much of the gold is lost to seawater. Despite this, both chimney types are relatively gold-enriched, which points to a further underlying cause for high gold at the BVF such as interaction of hydrothermal fluids with ultramafic lithologies in the basement. The final gold composition of the deposit is partially controlled by loss of gold during mass-wasting of the material, with gold depletion most prevalent in blocks formed at beehive-type chimneys. The BVF demonstrates that the overall gold content of a massive sulfide deposit is the sum of basement, precipitation, and surface processes.Plain Language SummaryMineral deposits form on the seafloor at hydrothermal vent sites and are rich in metals including copper, zinc, lead, and sometimes precious metals like gold and silver. However, the processes controlling the amount of gold that ends up in these deposits is not clearly understood. In this article we show that as hydrothermal fluid vents

  14. Morphotypes of virus-like particles in two hydrothermal vent fields on the East Scotia Ridge, Antarctia


    Millard, Andrew D.; Hands-Portman, Ian; Zwirglmaier, Katrin


    Viruses from extreme environments are still largely unexplored and may harbor unseen genetic potential. Here, we present a first glance at the morphological diversity of virus like particles (VLPs) from an environment that is extreme in more than one respect: two recently discovered hydrothermal vent fields on the East Scotia Ridge in the Southern Ocean near Antarctica. They are the southernmost hydrothermal sites found to date and have been shown to present a new biogeographic province, cont...

  15. Influence of hydrothermal venting on water column properties in the crater of the Kolumbo submarine volcano, Santorini volcanic field (Greece) (United States)

    Christopoulou, Maria E.; Mertzimekis, Theo J.; Nomikou, Paraskevi; Papanikolaou, Dimitrios; Carey, Steven; Mandalakis, Manolis


    The Kolumbo submarine volcano, located 7 km northeast of the island of Santorini, is part of Santorini's volcanic complex in the south Aegean Sea, Greece. Kolumbo's last eruption was in 1650 AD. However, a unique and active hydrothermal vent field has been revealed in the northern part of its crater floor during an oceanographic survey by remotely operated vehicles (ROVs) in 2006. In the present study, conductivity-temperature-depth (CTD) data collected by ROV Hercules during three oceanographic surveys onboard E/V Nautilus in 2010 and 2011 have served to investigate the distribution of physicochemical properties in the water column, as well as their behavior directly over the hydrothermal field. Additional CTD measurements were carried out in volcanic cone 3 (VC3) along the same volcanic chain but located 3 km northeast of Kolumbo where no hydrothermal activity has been detected to date. CTD profiles exhibit pronounced anomalies directly above the active vents on Kolumbo's crater floor. In contrast, VC3 data revealed no such anomalies, essentially resembling open-sea (background) conditions. Steep increases of temperature (e.g., from 16 to 19 °C) and conductivity near the maximum depth (504 m) inside Kolumbo's cone show marked spatiotemporal correlation. Vertical distributions of CTD signatures suggest a strong connection to Kolumbo's morphology, with four distinct zones identified (open sea, turbid flow, invariable state, hydrothermal vent field). Additionally, overlaying the near-seafloor temperature measurements on an X-Y coordinate grid generates a detailed 2D distribution of the hydrothermal vent field and clarifies the influence of fluid discharges in its formation.

  16. Morphotypes of virus-like particles in two hydrothermal vent fields on the East Scotia Ridge, Antarctica. (United States)

    Millard, Andrew D; Hands-Portman, Ian; Zwirglmaier, Katrin


    Viruses from extreme environments are still largely unexplored and may harbor unseen genetic potential. Here, we present a first glance at the morphological diversity of virus like particles (VLPs) from an environment that is extreme in more than one respect: two recently discovered hydrothermal vent fields on the East Scotia Ridge in the Southern Ocean near Antarctica. They are the southernmost hydrothermal sites found to date and have been shown to present a new biogeographic province, containing several new macrofaunal species and associated microbial organisms. Transmission electron microscopy revealed a range of tailed and untailed VLPs of various morphologies as well as an unusual long rod-shaped VLP with three long filaments. Based on its distant similarity with several known archaeal viruses, we hypothesize that this presents a new viral morphology that most likely infects an archaeon. Notably absent in the samples we analyzed were lemon- or spindle-shaped VLPs that have previously been described in other hydrothermal vent settings.

  17. Comparison of Five Hydrothermal Vent Fields at the Mid-Atlantic Ridge: Which Parameters Control the Differences in Fluid Geochemistry? (United States)

    Schmidt, K.; Koschinsky, A.; Garbe-Schönberg, D.; Seifert, R.


    Five different high-temperature hydrothermal vent sites along the Mid-Atlantic Ridge are investigated within a special priority program funded by the German Research Foundation (SPP 1144). The sites are all located at 3000 m water depth (near the critical point of seawater). Comparing the geochemical signature of the hydrothermal fluids with respect to the individual setting, it is possible to distinguish between the major controlling parameters as they are phase separation in the supercritical region of seawater, temperature, and host rock composition. Three of the vent sites were found at 4°49'S on the MAR in a young post-eruptive basaltic setting. Two of them are characterized by strong phase separation and the highest temperatures measured so far along the MAR (up to 407°C), assuming a very shallow heat source. It is assumed, that this hydrothermal system newly formed after a big eruption event in this region. The other one, although located at a distance of maximum 2 km from the other two, emanates somewhat cooler fluids (up to 349°C), with no indications for boiling and phase separation Despite their spatial proximity and the identical basaltic host rock in which these fields are situated, the vent fields show a clearly different fluid chemistry with depletion of alkali and earth alkali elements and some trace metals in the very hot, phase separated fluids. The Logatchev field at 14°45'N is located in an ultramafic setting with outcropping peridotitic and gabbroic rocks. The chlorinity of the fluids does not clearly indicate phase separation. Compared to the non-phase separated basaltic system at 4°49'S MAR the fluids are characterized by significantly higher concentrations of hydrogen and methane due to the serpentinization reactions, lower silica and lithium concentrations and a depletion of boron. A identical chemical signature characterizes a recently discovered system at 8°18'S, the Nibelungen field. Host rock composition with both mafic and


    Energy Technology Data Exchange (ETDEWEB)

    Thomas C. Chidsey Jr; David E. Eby


    Over 400 million barrels (64 million m{sup 3}) of oil have been produced from the shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation in the Paradox Basin, Utah and Colorado. With the exception of the giant Greater Aneth field, the other 100 plus oil fields in the basin typically contain 2 to 10 million barrels (0.3-1.6 million m{sup 3}) of original oil in place. Most of these fields are characterized by high initial production rates followed by a very short productive life (primary), and hence premature abandonment. Only 15 to 25 percent of the original oil in place is recoverable during primary production from conventional vertical wells. An extensive and successful horizontal drilling program has been conducted in the giant Greater Aneth field. However, to date, only two horizontal wells have been drilled in small Ismay and Desert Creek fields. The results from these wells were disappointing due to poor understanding of the carbonate facies and diagenetic fabrics that create reservoir heterogeneity. These small fields, and similar fields in the basin, are at high risk of premature abandonment. At least 200 million barrels (31.8 million m{sup 3}) of oil will be left behind in these small fields because current development practices leave compartments of the heterogeneous reservoirs undrained. Through proper geological evaluation of the reservoirs, production may be increased by 20 to 50 percent through the drilling of low-cost single or multilateral horizontal legs from existing vertical development wells. In addition, horizontal drilling from existing wells minimizes surface disturbances and costs for field development, particularly in the environmentally sensitive areas of southeastern Utah and southwestern Colorado.

  19. Analysis of quench-vent pressures for present design of ITER (International Thermonuclear Experimental Reactor) TF (toroidal field) coils

    Energy Technology Data Exchange (ETDEWEB)

    Slack, D.S.


    The International Thermonuclear Experimental Reactor (ITER) is a new tokamak design project with joint participation from Japan, the European Community, the Union of the Soviet Union, and the United States. This paper examines the effects of a quench within the toroidal field (TF) coils based on current ITER design. It is a preliminary, rough analysis. Its intent is to assist ITER designers while more accurate computer codes are being developed and to provide a check against these more rigorous solutions. Rigorous solutions to the quench problem are very complex involving three- dimensional heat transfer, extreme changes in heat capacities and copper resistivity, and varying flow dynamics within the conductors. This analysis addresses all these factors in an approximate way. The result is much less accurate than a rigorous analysis. Results here could be in error as much as 30 to 40 percent. However, it is believed that this paper can still be very useful to the coil designer. Coil pressures and temperatures vs time into a quench are presented. Rate of helium vent, energy deposition in the coil, and depletion of magnetic stored energy are also presented. Peak pressures are high (about 43 MPa). This is due to the very long vent path length (446 m), small hydraulic diameters, and high current densities associated with ITER's cable-in-conduit design. The effects of these pressures as well as the ability of the coil to be self protecting during a quench are discussed. 3 refs., 1 fig., 3 tabs.

  20. Field imaging spectroscopy and inferring a blind thrust earthquake history from secondary faulting: 1944 San Juan Earthquake, Argentina (United States)

    Ragona, Daniel Eduardo

    The studies presented in this dissertation provide new approaches to extract paleo-earthquake information from the geological record. The first chapter describes the development of Field Imaging Spectroscopy, a new methodology for data acquisition and analysis in paleoseismology. The study shows the steps followed from data acquisition, pre-processing, processing and analysis of high spatial and spectral resolution images obtained from cores and a large sample from a fault zone collected at Hog Lake, San Jacinto Fault, Southern California. The study demonstrate that hyperspectral data can be obtained in the field using portable scanners and that high spatial and spectral resolution in the visible to short wave infrared provide a way to enhance subtle or invisible stratigraphic and structural features. The second chapter focuses on the use of neural networks and naive Bayesian classifiers to automatically classify hyperspectral image data, providing an objective mapping of the structure of cores, samples and field exposures. The results of this study show that a system integrated by a hyperspectral scanner and pattern recognition algorithms can work as an enhanced eye and an objective classifier to provide the geologist with additional information that facilitates the final description, interpretation and correlation of the geology in paleoseismic exposures and cores. The hyperspectral dataset collected together with a spectral library of the materials observed in the excavation provide a new way to archive paleoseismological data for future analysis. Finally, in chapter 3, an innovative approach to study blind thrust faults is presented. The study of the secondary La Laja fault near San Juan, Argentina shows that the earthquake history recorded in a minor fault provides an indirect way to study the occurrence of large M˜7 earthquakes at depth. This investigation also provides the first and perhaps the longest record of the earthquake activity of a blind thrust

  1. Arsenic bioaccumulation and biotransformation in deep-sea hydrothermal vent organisms from the PACMANUS hydrothermal field, Manus Basin, PNG (United States)

    Price, Roy E.; Breuer, Christian; Reeves, Eoghan; Bach, Wolfgang; Pichler, Thomas


    Hydrothermal vents are often enriched in arsenic, and organisms living in these environments may accumulate high concentrations of this and other trace elements. However, very little research to date has focused on understanding arsenic bioaccumulation and biotransformation in marine organisms at deep-sea vent areas; none to date have focused organisms from back-arc spreading centers. We present for the first time concentration and speciation data for As in vent biota from several hydrothermal vent fields in the eastern Manus basin, a back-arc basin vent field located in the Bismark Sea, western Pacific Ocean. The gastropods Alviniconcha hessleri and Ifremeria nautilei, and the mussel Bathymodiolus manusensis were collected from diffuse venting areas where pH was slightly lower (6.2-6.8), and temperature (26.8-10.5 °C) and arsenic concentrations (169.5-44.0 nM) were higher than seawater. In the tissues of these organisms, the highest total measured As concentrations were in the gills of A. hessleri (5580 mg kg-1), with 721 mg kg-1 and 43 mg kg-1 in digestive gland and muscle, respectively. I. nautilei contained 118 mg kg-1 in the gill, 108 mg kg-1 in the digestive gland and 22 mg kg-1 in the muscle. B. manusensis contained 15.7 mg kg-1 in the digestive gland, followed by 9.8 mg kg-1 and 4.5 mg kg-1 in its gill and muscle tissue, respectively. We interpret the decreasing overall total concentrations in each organism as a function of distance from the source of hydrothermally derived As. The high concentration of arsenic in A. hessleri gills may be associated with elemental sulfur known to occur in this organism as a result of symbiotic microorganisms. Arsenic extracted from freeze-dried A. hessleri tissue was dominated by AsIII and AsV in the digestive gland (82% and 16%, respectively) and gills (97% AsIII, 2.3% AsV), with only 1.8% and 0.2% arsenobetaine (As-Bet) in the digestive gland and gills, respectively. However, the muscle contained substantial amounts of

  2. A Diverse Community of Metal(loid Oxide Respiring Bacteria Is Associated with Tube Worms in the Vicinity of the Juan de Fuca Ridge Black Smoker Field.

    Directory of Open Access Journals (Sweden)

    Chris Maltman

    Full Text Available Epibiotic bacteria associated with tube worms living in the vicinity of deep sea hydrothermal vents of the Juan de Fuca Ridge in the Pacific Ocean were investigated for the ability to respire anaerobically on tellurite, tellurate, selenite, selenate, metavanadate and orthovanadate as terminal electron acceptors. Out of 107 isolates tested, 106 were capable of respiration on one or more of these oxides, indicating that metal(loid oxide based respiration is not only much more prevalent in nature than is generally believed, but also is an important mode of energy generation in the habitat. Partial 16S rRNA gene sequencing revealed the bacterial community to be rich and highly diverse, containing many potentially new species. Furthermore, it appears that the worms not only possess a close symbiotic relationship with chemolithotrophic sulfide-oxidizing bacteria, but also with the metal(loid oxide transformers. Possibly they protect the worms through reduction of the toxic compounds that would otherwise be harmful to the host.

  3. Seismic structure at the Kairei Hydrothermal vent field near the Rodriguez Triple Junction in the Indian Ocean (United States)

    Takata, H.; Sato, T.; Imai, Y.; Mori, T.; Noguchi, Y.; Kono, A.; Yamada, T.; Shinohara, M.


    Central Indian Ridge is located at the north of the Rodriguez Triple Junction and shows slow-intermediate spreading rate. The Kairei hydrothermal Field (KHF) was discovered in the first segment of Central Indian Ridge near the Rodriguez Triple Junction. The vent fluid which is extruding at the KHF has higher H2 content compared with other hydrothermal vent fluid in the world. Although The KHF itself exists above a basaltic rock massif, gabbro and mafic rocks were discovered on the seafloor around the KHF. These deep-seated rocks may contribute to the high H2concentration of the Kairei vent fluid .To understand how gabbro and mafic rocks are uplifted and exhumed on the seafloor, we conducted a seismic refraction/reflection survey using ocean bottom seismograms (OBSs). We conducted the seismic refraction/reflection survey from January 27 to March 19 in 2013 using S/V Yokosuka of Jamstec. In the experiment, we used 21 OBSs, an air gun (G.I.gun) and a single channel steamer cable. We obtained 5 survey lines NNW-SSE direction parallel to the ridge axis, 5 lines E-W direction and 5 lines NNE-SSW direction. In addition to these lines, we acquired other 5 lines passing through the point above the KHF or Yokoniwa Rise, which is the north of the KHF. In analysis of refraction data, firstly, we estimated 2D velocity model under survey lines, which are parallel to the ridge axis, using the progressive model development method developed by Sato and Kennett (2000). Then, we constructed a 3D initial model and run the 3D tomographic method developed by Zelt and Barton (1998). The 1D velocity profile of the KHF seems to be similar to that of mid ocean ridges such as Mid Atlantic Ridge, East Pacific Rise. Seismic velocities under the KHF and Yokoniwa Rise reach about 6km/s at depth of 1~2 km below seafloor, probably indicating uplift of deep-seated rocks. In this presentation we will show 3D seismic structure of this area.

  4. Spatial patterns of zooplankton and nekton in a hydrothermally active axial valley on Juan de Fuca Ridge (United States)

    Skebo, Kristina; Tunnicliffe, Verena; Garcia Berdeal, Irene; Johnson, H. Paul


    Zooplankton and nekton at 2000 m depth in the axial valley of Endeavour Segment, Juan de Fuca Ridge, show marked variability in abundances in a plane at 20 m above bottom. A remotely operated vehicle flew a gridded rectangle 3.2×0.5 km that included two large high-temperature and two small low-temperature vent fields. Numbers of zooplankton, jellyfish, shrimp and fish were recorded with a video camera, and the abundance patterns were examined with the program SADIE ©. Each organism group displayed a distinctive distribution pattern. Abundance gaps over the high-temperature fields were significant and, for the more abundant copepods, were related to the locations of individual smokers. Pelagic shrimp and macrourid fish abundances were correlated and concentrated around the northern high temperature field. Distinct aggregations of zooplankton and nekton were correlated with the fluid indicators from both the low temperature diffuse effluent and the focused high temperature vents. Patterns were likely established by organism choice that forms aggregations and gaps, and by physical processes that entrain passive particles near vigorous smoker plumes. While enhanced plankton and nekton numbers were not observed over the vent fields, overall abundances in the axial valley may be sustained by production transported from the vent fields on the seafloor.

  5. PRex: An Experiment to Investigate Detection of Near-field Particulate Deposition from a Simulated Underground Nuclear Weapons Test Vent. (United States)

    Keillor, Martin E; Arrigo, Leah M; Baciak, James E; Chipman, Veraun; Detwiler, Rebecca S; Emer, Dudley F; Kernan, Warnick J; Kirkham, Randy R; MacDougall, Matthew R; Milbrath, Brian D; Rishel, Jeremy P; Seifert, Allen; Seifert, Carolyn E; Smart, John E


    A radioactive particulate release experiment to produce a near-field ground deposition representative of small-scale venting from an underground nuclear test was conducted to gather data in support of treaty capability development activities. For this experiment, a CO2-driven "air cannon" was used to inject (140)La, a radioisotope of lanthanum with 1.7-d half-life and strong gamma-ray emissions, into the lowest levels of the atmosphere at ambient temperatures. Witness plates and air samplers were laid out in an irregular grid covering the area where the plume was anticipated to deposit based on climatological wind records. This experiment was performed at the Nevada National Security Site, where existing infrastructure, radiological procedures, and support personnel facilitated planning and execution of the work. A vehicle-mounted NaI(Tl) spectrometer and a polyvinyl toluene-based backpack instrument were used to survey the deposited plume. Hand-held instruments, including NaI(Tl) and lanthanum bromide scintillators and high purity germanium spectrometers, were used to take in situ measurements. Additionally, three soil sampling techniques were investigated and compared. The relative sensitivity and utility of sampling and survey methods are discussed in the context of on-site inspection.

  6. Seafloor Uplift in Middle Valley, Juan de Fuca Ridge: New High-Resolution Pressure Data (United States)

    Inderbitzen, K. E.; Becker, K.; Davis, E. E.


    Currently, in-situ seafloor and basement pressures are continuously monitored and recorded by an ODP subseafloor hydrogeological observatory (CORK) located in Middle Valley, Juan de Fuca Ridge. Hole 857D was drilled in 1991 in thickly sedimented crust to a depth of 936 mbsf and instrumented with an original CORK that was replaced in 1996. A large hydrothermal field (Dead Dog) lies roughly 1.7 km north of the hole, and two isolated chimneys and several diffuse flow sites are located ~800 meters northeast. The borehole and the vent fields have been visited periodically by submersible/ROV since 1999. Recent results from the CORK at 857D have shown apparent seafloor uplift, supported by depth records from the submersible Alvin. A constant rate of pressure change of ~6 kPa/yr, from its initiation in 2005 to the visit in 2010, has reduced mean seafloor pressure by ~28 kPa, equivalent to nearly 3 meters of head. This uplift rate is several times the typical pre-eruption inflation rates observed at Axial Seamount further south along the Juan de Fuca Ridge. Initially, the apparent uplift at 857D did not seem to have any effect on local high-temperature hydrothermal venting, however recent operations in Middle Valley revealed distinct changes at not only the hydrothermal field to the northeast, but also a shutdown of high-temperature venting to the north of 857D. We will present new data from Middle Valley, including the first year of data collected by a high-resolution pressure data logger deployed at 857D in June, 2010.

  7. Potential field studies of the central San Luis Basin and San Juan Mountains, Colorado and New Mexico, and southern and western Afghanistan (United States)

    Drenth, Benjamin John

    This dissertation includes three separate chapters, each demonstrating the interpretive utility of potential field (gravity and magnetic) geophysical datasets at various scales and in various geologic environments. The locations of these studies are the central San Luis Basin of Colorado and New Mexico, the San Juan Mountains of southwestern Colorado, and southern and western Afghanistan. The San Luis Basin is the northernmost of the major basins that make up the Rio Grande rift, and interpretation of gravity and aeromagnetic data reveals patterns of rifting, rift-sediment thicknesses, distribution of pre-rift volcanic and sedimentary rocks, and distribution of syn-rift volcanic rocks. Syn-rift Santa Fe Group sediments have a maximum thickness of ˜2 km in the Sanchez graben near the eastern margin of the basin along the central Sangre de Cristo fault zone. Under the Costilla Plains, thickness of these sediments is estimated to reach ˜1.3 km. The Santa Fe Group sediments also reach a thickness of nearly 1 km within the Monte Vista graben near the western basin margin along the San Juan Mountains. A narrow, north-south-trending structural high beneath San Pedro Mesa separates the graben from the structural depression beneath the Costilla Plains. Aeromagnetic anomalies are interpreted to mainly reflect variations of remanent magnetic polarity and burial depth of the 5.3-3.7 Ma Servilleta basalt of the Taos Plateau volcanic field. Magnetic-source depth estimates indicate patterns of subsidence following eruption of the basalt and show that the Sanchez graben has been the site of maximum subsidence. One of the largest and most pronounced gravity lows in North America lies over the rugged San Juan Mountains in southwestern Colorado. A buried, low-density silicic batholith related to an Oligocene volcanic field coincident with the San Juan Mountains has been the accepted interpretation of the source of the gravity low since the 1970s. However, this interpretation was

  8. Dissolved Fe and Fe binding ligand concentrations at the hydrothermal vent fields in the Coriolis Troughs, New Hebrides Island Arc (United States)

    Kleint, C.; Hawkes, J. A.; Sander, S. G.; Koschinsky, A.


    It is globally accepted that hydrothermal vent fluids are highly enriched in Fe compared to the surrounding seawater and for long it was believed that the majority of the dissolved Fe is precipitated either directly out of the fluid with seawater contact or from the plume within a short distance. Recent research at other deep-sea hydrothermal vents has shown, however, that organic ligands are able to keep Fe soluble and therefore facilitating its transport into the open ocean. This is important since Fe is also considered a limiting factor for primary production in large parts of the world`s surface ocean. The New Hebrides Island Arc is not studied well with respect to the fluid chemistry of its numerous vents. Up until now, no data is published for the crucial micronutrient Fe in these fluids. Several hydrothermal vent fluids, divided into mixing zone, outlet and pure fluid as well as one hydrothermal plume from the Coriolis Troughs have been analyzed with respect to total dissolved Fe (dFe) and Fe binding ligands (FeL), using competitive ligand exchange - adsorptive cathodic stripping voltammetry (CLE - AdCSV) with Salicylaldoxime as the artificial ligand. Our dFe data for the hydrothermal plume show concentrations ranging from 9.6 nM to 30.1 nM, being highly enriched compared to the surrounding seawater. Good correlation is observed between dFe and turbidity, which can be used as a proxy for hydrothermal plumes. Hydrothermal fluid samples collected near and directly from the vent outlet show total dissolved Fe concentrations varying from 0.46 µM up to 380 µM, respectively. We find enriched organic ligand concentrations in the plume samples as well as in the samples taken near the hydrothermal vent outlets. Pure hydrothermal fluid samples with an in-situ temperature of up to 370 °C show different ligand properties than low to mid temperature samples.

  9. Brine formation via deliquescence by salts found near Don Juan Pond, Antarctica: Laboratory experiments and field observational results (United States)

    Gough, R. V.; Wong, J.; Dickson, J. L.; Levy, J. S.; Head, J. W.; Marchant, D. R.; Tolbert, M. A.


    The observed darkening of water tracks near Don Juan Pond (DJP) as well as the formation of wet patches elsewhere in the McMurdo Dry Valleys is attributed at least partially to deliquescence, a process by which salts absorb atmospheric water vapor and form brine, coupled with liquid-phase growth when the atmospheric relative humidity exceeds the water activity. Here we perform laboratory experiments to investigate the temperature and relative humidity conditions necessary for deliquescence to occur in calcium chloride-rich sediments collected from the DJP watershed. We use a Raman microscope equipped with an environmental cell to study both deliquescence and efflorescence (recrystallization) of the soluble salt component of DJP soils between -30 and +15 °C. In this temperature range, we find that the soluble salt component of the DJP sediments begins to deliquesce between 19 and 46% RH, slightly higher than the deliquescence relative humidity of the primary pure component, calcium chloride. We find a limited hysteresis between deliquescence and efflorescence, but much greater supersaturation of the salt brine can occur at temperatures above 0 °C. The relative humidity conditions were varied either slowly (over ∼8 h) to observe near-equilibrium phases or rapidly (over round hydrological cycle of the DJP watershed. Steep-sloped water tracks found near DJP have been suggested as a terrestrial analog for recurring slope lineae on Mars, for which salt deliquescence is a proposed formation mechanism. Therefore, understanding the formation of deliquescent brines in a hyper-arid region on Earth may have relevance to Mars.

  10. Imaging hydrothermal roots along the Endeavour segment of the Juan de Fuca ridge using elastic full waveform inversion. (United States)

    Arnulf, A. F.; Harding, A. J.; Kent, G. M.


    The Endeavour segment is a 90 km-long, medium-spreading-rate, oceanic spreading center located on the northern Juan de Fuca ridge (JDFR). The central part of this segment forms a 25-km-long volcanic high that hosts five of the most hydrothermally active vent fields on the MOR system, namely (from north to south): Sasquatch, Salty Dawg, High Rise, Main Endeavour and Mothra. Mass, heat and chemical fluxes associated to vigorous hydrothermal venting are large, however the geometry of the fluid circulation system through the oceanic crust remains almost completely undefined. To produce high-resolution velocity/reflectivity structures along the axis of the Endeavour segment, here, we combined a synthetic ocean bottom experiment (SOBE), 2-D traveltime tomography, 2D elastic full waveform and reverse time migration (RTM). We present velocity and reflectivity sections along Endeavour segment at unprecedented spatial resolutions. We clearly image a set of independent, geometrically complex, elongated low-velocity regions linking the top of the magma chamber at depth to the hydrothermal vent fields on the seafloor. We interpret these narrow pipe-like units as focused regions of hydrothermal fluid up-flow, where acidic and corrosive fluids form pipe-like alteration zones as previously observed in Cyprus ophiolites. Furthermore, the amplitude of these low-velocity channels is shown to be highly variable, with the strongest velocity drops observed at Main Endeavour, Mothra and Salty Dawg hydrothermal vent fields, possibly suggesting more mature hydrothermal cells. Interestingly, the near-seafloor structure beneath those three sites is very similar and highlights a sharp lateral transition in velocity (north to south). On the other hand, the High-Rise hydrothermal vent field is characterized by several lower amplitudes up-flow zones and relatively slow near-surface velocities. Last, Sasquatch vent field is located in an area of high near-surface velocities and is not

  11. Barite in hydrothermal environments as a recorder of subseafloor processes: a multiple-isotope study from the Loki's Castle vent field. (United States)

    Eickmann, B; Thorseth, I H; Peters, M; Strauss, H; Bröcker, M; Pedersen, R B


    Barite chimneys are known to form in hydrothermal systems where barium-enriched fluids generated by leaching of the oceanic basement are discharged and react with seawater sulfate. They also form at cold seeps along continental margins, where marine (or pelagic) barite in the sediments is remobilized because of subseafloor microbial sulfate reduction. We test the possibility of using multiple sulfur isotopes (δ34S, Δ33S, ∆36S) of barite to identify microbial sulfate reduction in a hydrothermal system. In addition to multiple sulfur isotopes, we present oxygen (δ18O) and strontium (87Sr/86Sr) isotopes for one of numerous barite chimneys in a low-temperature (~20 °C) venting area of the Loki's Castle black smoker field at the ultraslow-spreading Arctic Mid-Ocean Ridge (AMOR). The chemistry of the venting fluids in the barite field identifies a contribution of at least 10% of high-temperature black smoker fluid, which is corroborated by 87Sr/86 Sr ratios in the barite chimney that are less radiogenic than in seawater. In contrast, oxygen and multiple sulfur isotopes indicate that the fluid from which the barite precipitated contained residual sulfate that was affected by microbial sulfate reduction. A sulfate reduction zone at this site is further supported by the multiple sulfur isotopic composition of framboidal pyrite in the flow channel of the barite chimney and in the hydrothermal sediments in the barite field, as well as by low SO4 and elevated H2S concentrations in the venting fluids compared with conservative mixing values. We suggest that the mixing of ascending H2- and CH4-rich high-temperature fluids with percolating seawater fuels microbial sulfate reduction, which is subsequently recorded by barite formed at the seafloor in areas where the flow rate is sufficient. Thus, low-temperature precipitates in hydrothermal systems are promising sites to explore the interactions between the geosphere and biosphere in order to evaluate the microbial impact on

  12. Can high-temperature, high-heat flux hydrothermal vent fields be explained by thermal convection in the lower crust along fast-spreading Mid-Ocean Ridges? (United States)

    Fontaine, Fabrice J.; Rabinowicz, M.; Cannat, M.


    We present numerical models to explore possible couplings along the axis of fast-spreading ridges, between hydrothermal convection in the upper crust and magmatic flow in the lower crust. In an end-member category of models corresponding to effective viscosities μM lower than 1013 Pa.s in a melt-rich lower crustal along-axis corridor and permeability k not exceeding ˜10-16 m2 in the upper crust, the hot, melt-rich, gabbroic lower crust convects as a viscous fluid, with convection rolls parallel to the ridge axis. In these models, we show that the magmatic-hydrothermal interface settles at realistic depths for fast ridges, i.e., 1-2 km below seafloor. Convection cells in both horizons are strongly coupled and kilometer-wide hydrothermal upflows/plumes, spaced by 8-10 km, arise on top of the magmatic upflows. Such magmatic-hydrothermal convective couplings may explain the distribution of vent fields along the East (EPR) and South-East Pacific Rise (SEPR). The lower crustal plumes deliver melt locally at the top of the magmatic horizon possibly explaining the observed distribution of melt-rich regions/pockets in the axial melt lenses of EPR and SEPR. Crystallization of this melt provides the necessary latent heat to sustain permanent ˜100 MW vents fields. Our models also contribute to current discussions on how the lower crust forms at fast ridges: they provide a possible mechanism for focused transport of melt-rich crystal mushes from moho level to the axial melt lens where they further crystallize, feed eruptions, and are transported both along and off-axis to produce the lower crust.

  13. Continental shelf and slope gas venting off Cascadia (United States)

    Scherwath, Martin; Riedel, Michael; Roemer, Miriam; Juniper, Kim; Heesemann, Martin; Mihaly, Steven; Paull, Charles; Spence, George; Veloso, Mario


    Along the Cascadia Margin in the Northeast Pacific, off the coasts of British Columbia, Washington and Oregon, hundreds natural gas vent locations have been mapped using sonar data from ships, autonomous underwater and also remotely operated vehicles, as well as camera and seafloor sonar data. We have combined observed vent locations from published literature as well as analyzed original data from research cruises and fishing sonar from various archives, including those of Natural Resources Canada, the Monterey Bay Aquarium Research Institute, Ocean Networks Canada, the National Ocean and Atmospheric Administration, and the Schmidt Ocean Institute. In total, over 950 individual vents are now mapped. By far the highest accumulation of gas vent locations appear both shallow (<250 m) and concentrated towards the mouth of the Juan de Fuca Strait, however these observations are naturally biased toward the distribution of the observation footprints. Normalized observations confirm the shallow (<500 m) high concentrations of gas vents but also establish some deeper sections of focused venting activity. We will speculate about the reasons behind the distribution, focus on specific examples, extrapolate for rough margin flux rate ranges and comment on short-comings and future directions for margin-wide gas vent studies.

  14. A Field Study of Wall Furnace Venting and Coincident Exhaust Fan Usage in 16 Northern California Apartments

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Less, Brennan D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Delp, William W. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Brooks, Andrew [Association for Energy Affordability, Emeryville, CA (United States); Cohn, Sebastian [Association for Energy Affordability, Emeryville, CA (United States); Finn, Brian [Association for Energy Affordability, Emeryville, CA (United States)


    To inform efforts to improve combustion appliance testing in residential energy efficiency programs, we studied the frequency of coincident fan use and depressurization-induced downdrafting and spillage from atmospherically vented (i.e., natural draft) wall furnaces in airtight apartments. Indoor environmental conditions, heating appliance operation, use of exhaust fans, and cooking with stovetop or oven were monitored for approximately three weeks each in 16 apartment units in two buildings in Northern California. Apartments also were assessed using standard combustion appliance safety test methods and enhanced protocols. Monitoring occurred in February and March of 2016, with heating demand corresponding to 7.3 ± 0.5 heating degree-days at a 65ºF reference temperature. Most of the furnaces spilled combustion products when the apartments were depressurized in the “worst-case” challenge condition of all exhaust fans operating at their highest settings and all windows closed. Many also spilled under less challenging conditions (e.g., with kitchen exhaust fan on low and bathroom fan operating). On average, bathroom exhaust fans were operated 3.9% of monitored minutes (13.5% max), and cooking (burner or kitchen fan operation) occurred 4.6% of minutes (max 13.3%). Event lengths averaged 17 minutes (max 540) and 34 minutes (max 324), respectively. Their coincident operation averaged 0.34% of minutes (max 2.0%), with average event length of 13 minutes (max 92 minutes). This suggests that the operation of apartment units at or near the currently used worst-case challenge condition is quite rare. Wall furnace burners operated an average of 2.8% of minutes (max of 8.9%), with average burner cycle length of 14 minutes (max 162). Coincident bath fan use, cooking and wall furnace operation was very rare, occurring only a handful of times across all apartments. The highest rate was 0.075% of monitored minutes in one apartment, and the longest event length was 12 minutes

  15. Phylogenetic characterization of episymbiotic bacteria hosted by a hydrothermal vent limpet (Lepetodrilidae, Vetigastropoda)

    NARCIS (Netherlands)

    Bates, A.E.; Harme, T.L.; Roeselers, G.; Cavanaugh, C.M.


    Marine invertebrates hosting chemosynthetic bacterial symbionts are known from multiple phyla and represent remarkable diversity in form and function. The deep-sea hydrothermal vent limpet Lepetodrilus fucensis from the Juan de Fuca Ridge complex hosts a gill symbiosis of particular interest because

  16. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

    Lautkaski, R. [VTT Energy, Espoo (Finland). Energy Systems


    The report is an introduction to vented gas explosions for nonspecialists, particularly designers of plants for flammable gases and liquids. The phenomena leading to pressure generation in vented gas explosions in empty and congested rooms are reviewed. The four peak model of vented gas explosions is presented with simple methods to predict the values of the individual peaks. Experimental data on the external explosion of dust and gas explosions is discussed. The empirical equation relating the internal and external peak pressures in vented dust explosions is shown to be valid for gas explosion tests in 30 m{sup 3} and 550 m{sup 3} chambers. However, the difficulty of predicting the internal peak pressure in large chambers remains. Methods of explosion relief panel design and principles of vent and equipment layout to reduce explosion overpressures are reviewed. (orig.) 65 refs.

  17. Boiling vapour-type fluids from the Nifonea vent field (New Hebrides Back-Arc, Vanuatu, SW Pacific): Geochemistry of an early-stage, post-eruptive hydrothermal system (United States)

    Schmidt, Katja; Garbe-Schönberg, Dieter; Hannington, Mark D.; Anderson, Melissa O.; Bühring, Benjamin; Haase, Karsten; Haruel, Christy; Lupton, John; Koschinsky, Andrea


    In 2013, high-temperature vent fluids were sampled in the Nifonea vent field. This field is located within the caldera of a large shield-type volcano of the Vate Trough, a young extensional rift in the New Hebrides back-arc. Hydrothermal venting occurs as clear and black smoker fluids with temperatures up to 368 °C, the hottest temperatures measured so far in the western Pacific. The physico-chemical conditions place the fluids within the two-phase field of NaCl-H2O, and venting is dominated by vapour phase fluids with Cl concentrations as low as 25 mM. The fluid composition, which differs between the individual vent sites, is interpreted to reflect the specific geochemical fluid signature of a hydrothermal system in its initial, post-eruptive stage. The strong Cl depletion is accompanied by low alkali/Cl ratios compared to more evolved hydrothermal systems, and very high Fe/Cl ratios. The concentrations of REY (180 nM) and As (21 μM) in the most Cl-depleted fluid are among the highest reported so far for submarine hydrothermal fluids, whereas the inter-element REY fractionation is only minor. The fluid signature, which has been described here for the first time in a back-arc setting, is controlled by fast fluid passage through basaltic volcanic rocks, with extremely high water-rock ratios and only limited water-rock exchange, phase separation and segregation, and (at least) two-component fluid mixing. Metals and metalloids are unexpectedly mobile in the vapour phase fluids, and the strong enrichments of Fe, REY, and As highlight the metal transport capacity of low-salinity, low-density vapours at the specific physico-chemical conditions at Nifonea. One possible scenario is that the fluids boiled before the separated vapour phase continued to react with fresh glassy lavas. The mobilization of metals is likely to occur by leaching from fresh glass and grain boundaries and is supported by the high water/rock ratios. The enrichment of B and As is further controlled

  18. Iron partitioning between the dissolved and particulate phase within a rising hydrothermal plume: Beebe Vents, Piccard Hydrothermal Field, Mid-Cayman Rise. (United States)

    Breier, J. A., Jr.; Estapa, M. L.; German, C. R.


    Particle processes place first order controls on the transfer of high temperature hydrothermal metals from the lithosphere to the oceans. Within buoyant rising hydrothermal plumes, settling attenuates metal concentrations, and settling is controlled by particle precipitation and growth. To improve our understanding of these processes we collected samples from rising hydrothermal plumes in the Piccard field of the Mid-Cayman Rise in 2012 and 2013. We used a combination of remotely operated vehicle and water-rosette sampling techniques. From these samples, we measured dissolved and particulate Fe and optical proxies of particle size distribution in vertical plume profiles spanning >150 m of the initial plume rise. The measurements from 2013 show that more than 50% of the >1 mmol per kg vent flux partitions to the particulate phase within the first meter of plume rise. The plume is rapidly diluted over 1000 times in the first 16 meters but during this stage the partitioning ratio between dissolved and particulate Fe remains relatively constant. Above 16 m, plume dilution continues more slowly but the Fe partitioning ratio shifts towards the dissolved until 90% of the total Fe concentration, 620 nmol per kg plume fluid, is dissolved. It is not clear to what extent this shift is due to settling or oxidative particle dissolution and both are likely. However, particle size distribution measurements from 2013 show the plume is dominated by small particles, and that particles >100 μm are rare. Thus in this setting, despite rapid precipitation, particle growth and settling are surprisingly slow and a relatively stronger role for particle dissolution is suggested.

  19. Remembering Juan Navia. (United States)

    Dasanayake, A P; Li, Y; Maetz, H M; Vermund, S H


    Juan Navia died on September 4, 2010. Those who knew him as the director of the University of Alabama's John J. Sparkman Center for International Public Health Education and later the dean of UAB School of Public Health watched him train and shape the next generation of global public health leaders with a kind heart and a firm, but gentle, hand. On this third anniversary of Professor Navia's passing, in response to an invitation from the Journal of Dental Research to write an essay on an educator who influenced the professional trajectories of many people, we have put together an account of some of his contributions and attributes to highlight this remarkable leader's accomplishments in and impact on dental public health and global nutrition.

  20. Seismic and Tectonic Monitoring of the Endeavour Ridge Segment—Recent and Future Expansion of Ocean Networks Canada's NEPTUNE Observatory on the Juan de Fuca Ridge (United States)

    Heesemann, M.; Davis, E. E.; Scherwath, M.; Kao, H.; Coogan, L. A.; Rogers, G. C.; Wilcock, W. S. D.


    Ocean Networks Canada's (ONC) NEPTUNE observatory provides real-time access to sensors on the Endeavour Ridge Segment (Endeavour)—a focus site on the Juan de Fuca Ridge System that is complementary to one on Axial Volcano that is connected through the Ocean Observatories Initiative's (OOI) Cabled Array. While first instruments (including cameras, a short-period seismometer, and vent monitoring instruments) installed at the Main Endeavour vent field have been sending data since summer 2010, unreliable extension cables precluded continuous time-series from other nearby locations. With the successful installation of four extension cables, the summer of 2016 represents an important milestone in the instrumentation of the Endeavour Ridge Segment. We will present an overview of the data that are available in near real-time from Endeavour and new instrumentation that is scheduled for installation in 2017, and highlight first results derived from the new seismo-tectonic network now in operation. This network consists of three short-period seismometers (Mothra Field, Main Endeavour Field, Regional Circulation North), one broadband seismometer (western Ridge Flank), and four bottom pressure recorders (Mothra Field, Regional Circulation South, Main Endeavour Field, western Ridge Flank). The pressure recorders will provide both seismic and oceanographic data, and allow to measure differential vertical motion among the sites. We will also highlight a new technique to determine long period seafloor deformation from broadband seismometer mass-position measurements, using data from the Ridge Flank instrument as an example.

  1. Some features of the trace metal biogeochemistry in the deep-sea hydrothermal vent fields (Menez Gwen, Rainbow, Broken Spur at the MAR and 9°50‧N at the EPR): A synthesis (United States)

    Demina, Ludmila L.; Holm, Nils G.; Galkin, Sergey V.; Lein, Alla Yu.


    Along with summarizing the published literature and our own data some new results on properties of the trace metal biogeochemistry in the deep-sea hydrothermal ecosystems at the Mid-Atlantic Ridge (MAR) and East Pacific Rise (EPR) are shown. Differences in mean concentrations of big group of trace metals (Fe, Mn, Zn, Cu, Ni, Cr, Co, As, Pb, Cd, Ag, Hg) between the biotope water of the low- and high-temperature hydrothermal vent fields were firstly revealed. The same trace metals were studied in different groups of organisms within different temperature zones at one and the same vent field (9°50‧N EPR), as well as in fauna inhabiting geochemically different vent sites. Distribution patterns of Fe, Mn, Zn, Cu, Cd, Pb, Ag, Ni, Cr, Co, As, Se, Sb, and Hg in different taxa gave an evidence of the influence of environmental and biological parameters on their bioaccumulation in organisms. Among the animals a particular “champion” with respect to the trace metal content was found to be a polychaeta Alvinella pompejana that inhabits the hottest places of the vent sulfide chimneys of the 9°50‧N field, EPR. New data on the trace metal distribution between soft tissues and carbonate shell let us estimate a role of biomineralization in the accumulation of metals in the Bathimodiolus mussels. Contrasting geochemical behavior was revealed for Cu that is enriched in soft tissues of mussels and depleted in shells, on the one hand, and Mn that is accumulated almost totally in mussel shells, on the other hand. Deep-sea hydrothermal biological communities demonstrate a strong concentration function, and bioconcentration factors (BCF) of trace metals estimated for Bathimodiolus mussels collected at the four hydrothermal fields vary within the limits of n102-n105 and are similar to that of the littoral mussels. Due to this and to the high values of biomasses per square meter, the hydrothermal fauna may be considered as a newly discovered biological filter of the oceans.

  2. Atacamite and paratacamite from the ultramafic-hosted Logatchev seafloor vent field (14°45′N, Mid-Atlantic Ridge) (United States)

    Dekov, Vesselin; Boycheva, Tanya; Halenius, Ulf; Petersen, Sven; Billstrom, Kjell; Stummeyer, Jens; Kamenov, G.; Shanks, W.


    Atacamite and paratacamite are ubiquitous minerals associated with Cu-rich massive sulfides at the Logatchev hydrothermal field (Mid-Atlantic Ridge). In this work we provide new details on the mineralogy and geochemistry of these basic cupric chlorides. Our data support the notion that atacamite and paratacamite formation at submarine vent fields is an alteration process of hydrothermal Cu-sulfides. Secondary Cu-sulfides (bornite, covellite) are unstable at ambient seawater conditions and will dissolve. Dissolution is focused at the sulfide–seawater contact, leading to release of Fe2+ and Cu+ and formation of residual chalcocite through an intermediate Cu5S4 phase. Most of the released Fe2+ oxidizes immediately and precipitates as FeOOH directly on the chalcocite rims whereas Cu as chloride complexes (CuCl2−, CuCl32-) remains in solution at the same Eh. Cuprous–chloride complexes migrate from the reaction zone and upon increasing Eh precipitate as Cu2Cl(OH)3. As a consequence of this, the sulfide–seawater reaction interface is clearly marked by thin chalcocite–FeOOH bands and the entire assemblage is mantled by atacamite (or paratacamite). Our mineralogical, petrographic, geochemical and isotopic studies suggest that there are two types of atacamite (and/or paratacamite) depending on their mode of precipitation. Type 1 atacamite precipitated directly on the parent sulfides as evidenced by mantling of the sulfides, absence of detrital mineral grains, a preserved conspicuous positive Eu anomaly and a negligible negative Ce anomaly similar to those of the parent sulfide. In addition, Au concentrations are slightly lower than those of the parent sulfides, which suggest minimal transport of Au-ions after their release from the sulfides. Furthermore, the low content of the rare earth elements implies short contact time with the ambient seawater. The Sr–Nd–Pb-isotopic signatures of type 1 atacamite confirm the genetic association with the parent sulfides and

  3. Measure Guideline: Passive Vents

    Energy Technology Data Exchange (ETDEWEB)

    Berger, David [Consortium for Advanced Residential Buildings, Norwalk, CT (United States); Neri, Robin [Consortium for Advanced Residential Buildings, Norwalk, CT (United States)


    This document addresses the use of passive vents as a source of outdoor air in multifamily buildings. The challenges associated with implementing passive vents and the factors affecting performance are outlined. A comprehensive design methodology and quantified performance metrics are provided. Two hypothetical design examples are provided to illustrate the process. This document is intended to be useful to designers, decision-makers, and contractors implementing passive ventilation strategies. It is also intended to be a resource for those responsible for setting high-performance building program requirements, especially pertaining to ventilation and outdoor air. To ensure good indoor air quality, a dedicated source of outdoor air is an integral part of high-performance buildings. Presently, there is a lack of guidance pertaining to the design and installation of passive vents, resulting in poor system performance. This report details the criteria necessary for designing, constructing, and testing passive vent systems to enable them to provide consistent and reliable levels of ventilation air from outdoors.

  4. The relative effects of particles and turbulence on acoustic scattering from deep-sea hydrothermal vent plumes. (United States)

    Xu, Guangyu; Di Iorio, Daniela


    Acoustic methods are applied to the investigation and monitoring of a vigorous hydrothermal plume within the Main Endeavor vent field at the Endeavor segment of the Juan de Fuca Ridge. Forward propagation and scattering from suspended particulates using Rayleigh scattering theory is shown to be negligible (log-amplitude variance σ(χ) (2)~10(-7)) compared to turbulence induced by temperature fluctuations (σ(χ) (2)~0.1). The backscattering from turbulence is then quantified using the forward scattering derived turbulence level, which gives a volume backscattering strength of s(V)=6.5 × 10(-8) m(-1). The volume backscattering cross section from particulates can range from s(V)=3.3 × 10(-6) to 7.2 × 10(-10) m(-1) depending on the particle size. These results show that forward scatter acoustic methods in hydrothermal vent applications can be used to quantify turbulence and its effect on backscatter measurements, which can be a dominant factor depending on the particle size and its location within the plume. © 2011 Acoustical Society of America

  5. Eruptive and noneruptive calderas, northeastern San Juan Mountains, Colorado: Where did the ignimbrites come from? (United States)

    Lipman, P.W.; McIntosh, W.C.


    The northeastern San Juan Mountains, the least studied portion of this well-known segment of the Southern Rocky Mountains Volcanic Field are the site of several newly identified and reinterpreted ignimbrite calderas. These calderas document some unique eruptive features not described before from large volcanic systems elsewhere, as based on recent mapping, petrologic data, and a large array of newly determined high-precision, laser-fusion 40Ar/39Ar ages (140 samples). Tightly grouped sanidine ages document exceptionally brief durations of 50-100 k.y. or less for individual Oligocene caldera cycles; biotite ages are more variable and commonly as much as several hundred k.y. older than sanidine from the same volcanic unit. A previously unknown ignimbrite caldera at North Pass, along the Continental Divide in the Cochetopa Hills, was the source of the newly distinguished 32.25-Ma Saguache Creek Tuff (???400-500 km3). This regionally, distinctive crystal-poor alkalic rhyolite helps fill an apparent gap in the southwestward migration from older explosive activity, from calderas along the N-S Sawatch locus in central Colorado (youngest, Bonanza Tuff at 33.2 Ma), to the culmination of Tertiary volcanism in the San Juan region, where large-volume ignimbrite eruptions started at ca. 29.5 Ma and peaked with the enormous Fish Canyon Tuff (5000 km3) at 28.0 Ma. The entire North Pass cycle, including caldera-forming Saguache Creek Tuff, thick caldera-filling lavas, and a smaller volume late tuff sheet, is tightly bracketed at 32.25-32.17 Ma. No large ignimbrites were erupted in the interval 32-29 Ma, but a previously unmapped cluster of dacite-rhyolite lava flows and small tuffs, areally associated with a newly recognized intermediate-composition intrusion 5 ?? 10 km across (largest subvolcanic intrusion in San Juan region) centered 15 km north of the North Pass caldera, marks a near-caldera-size silicic system active at 29.8 Ma. In contrast to the completely filled North Pass

  6. Noise reduction in steam-vent points at the Cerro Prieto geothermal field, BC; Reduccion del ruido en puntos de desfogue en el campo geotermico de Cerro Prieto, BC

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Herrera, Carlos A [Comision Federal de Electricidad, Residencia General de Cerro Prieto, Mexicali, B.C (Mexico)]. E-mail:


    Steam silencers have been placed on the power units regulation system of the Cerro Prieto geothermal field, but not where the steam-pipes vent high-pressure steam (rupture disks). Moreover, the power-unit silencers are large and their abilities to reduce noise depend on an external, uncontrollable factor: pores sizes in the volcanic rocks they are made of. Thus a compact, economic and relatively easy to construct metallic silencer was designed to be used at several points of dry-steam venting to minimize the noise. The design was based on orifice-plate equations and a prototype was constructed and tested. It proved capable of reducing noise by 30 decibels for atmospheric discharges of primary steam at operating pressures. The size of the silencer can be adjusted to the particular needs of each vent case. [Spanish] En el campo geotermico de Cerro Prieto solo existen silenciadores de vapor en el sistema de regulacion de las plantas generadoras, pero no en los sitios de desfogue de vapor a alta presion en los vaporductos (discos de ruptura). Ademas, los silenciadores de las plantas son muy robustos y su capacidad de reduccion del ruido depende de un factor externo no controlable, como es el tamano del poro de la roca volcanica con el que estan construidos. Por lo tanto, se diseno un silenciador metalico compacto, economico y relativamente facil de fabricar, para utilizarse en diversos puntos de descarga de vapor seco a fin de minimizar el ruido. El diseno se realizo con base en las ecuaciones de la placa de orificio. Se construyo un prototipo cuyas pruebas demostraron que es capaz de reducir el ruido hasta en 30 decibeles, al descargar desde la presion de operacion de vapor primario hacia la presion atmosferica. Las dimensiones del silenciador pueden ajustarse a las necesidades particulares de cada caso de desfogue.

  7. Counseling According to don Juan (United States)

    Pulvino, Charles J.; Lee, James L.


    This article specifies a number of precepts put forth by don Juan, a Yaqui Indian sorcerer. It also outlines the consequences of each precept for counselors. The intent is to facilitate the emergence of a new reality for counseling and other helping professions. (Author/BW)

  8. Antarctic marine biodiversity and deep-sea hydrothermal vents. (United States)

    Chown, Steven L


    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  9. Geology and fuel resources of the southern part of the San Juan Basin, New Mexico. Part 1, The coal field from Gallup eastward toward Mount Taylor, with a measured section of pre-Dakota(?) rocks near Navajo Church (United States)

    Sears, Julian D.


    The report describes the geology and coal deposits of the southwestern part of the San Juan Basin, N.Mex. The field lies northeast of the town of Gallup, on the Atchison, Topeka & Santa Fe Railway, and is an irregular tract of about 630 square miles in central and west-central McKinley County; it includes the southeast corner of the Navajo Indian Reservation. Settlement is confined to the white families at a few trading posts and the Indian agency at Crown Point and to scattered Navajo Indians. The land forms, drainage, vegetation, and climate are those typical of the highland in the semiarid Southwest.The investigation disclosed complicated relations of the Mancos shale and the Mesaverde formation, of Upper Cretaceous age, and a marked variation in the stratigraphic boundary between them. At the western edge of the field, as in the adjoining Gallup coal district, the Mancos consists of about 725 feet of marine shale almost wholly of Benton (lower Colorado) age. It is overlain by about 1,800 feet of chiefly estuarine and fluviatile deposits that represent the lower part of the Mesaverde formation. In ascending order the Mesaverde here consists of the Gallup sandstone member (which includes local lenses of valuable coal), the Dilco coal member, the Bartlett barren member, the Gibson coal member, and the Allison barren member. Eastward through the field the outcrops extend obliquely across the trend of old shore lines out into the ancient basin of marine deposition, and some of the beds consequently show a progressive lateral change into rocks of littoral and marine types. The Gallup sandstone member is in part replaced by marine shale of the Mancos. The upper part of the Dilco coal member is replaced by the Dalton sandstone member, and still farther east the bottom of the Dalton and the top of the remaining Dilco are replaced by the Mulatto tongue of the Mancos shale. The Bartlett barren member becomes coal-bearing and thus merges with the Gibson. The Gibson coal

  10. Airbag vent valve and system (United States)

    Peterson, Leslie D. (Inventor); Zimmermann, Richard E. (Inventor)


    An energy absorbing airbag system includes one or more vent valve assemblies for controlling the release of airbag inflation gases to maintain inflation gas pressure within an airbag at a substantially constant pressure during a ride-down of an energy absorbing event. Each vent valve assembly includes a cantilever spring that is flat in an unstressed condition and that has a free end portion. The cantilever spring is secured to an exterior surface of the airbag housing and flexed to cause the second free end portion of the cantilever spring to be pressed, with a preset force, against a vent port or a closure covering the vent port to seal the vent port until inflation gas pressure within the airbag reaches a preselected value determined by the preset force whereupon the free end portion of the cantilever spring is lifted from the vent port by the inflation gases within the airbag to vent the inflation gases from within the airbag. The resilience of the cantilever spring maintains a substantially constant pressure within the airbag during a ride-down portion of an energy absorbing event by causing the cantilever spring to vent gases through the vent port whenever the pressure of the inflation gases reaches the preselected value and by causing the cantilever spring to close the vent port whenever the pressure of the inflation gases falls below the preselected value.

  11. Safe venting of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, W.F.; Dewart, J.M.; Edeskuty, F.J.


    The disposal of hydrogen is often required in the operation of an experimental facility that contains hydrogen. Whether the vented hydrogen can be discharged to the atmosphere safely depends upon a number of factors such as the flow rate and atmospheric conditions. Calculations have been made that predict the distance a combustible mixture can extend from the point of release under some specified atmospheric conditions. Also the quantity of hydrogen in the combustible cloud is estimated. These results can be helpful in deciding of the hydrogen can be released directly to the atmosphere, or if it must be intentionally ignited. 15 refs., 5 figs., 2 tabs.

  12. Hydrothermal deposition on the Juan de Fuca Ridge over multiple glacial-interglacial cycles (United States)

    Costa, Kassandra M.; McManus, Jerry F.; Middleton, Jennifer L.; Langmuir, Charles H.; Huybers, Peter J.; Winckler, Gisela; Mukhopadhyay, Sujoy


    Hydrothermal systems play an important role in modern marine chemistry, but little is known about how they may have varied on 100,000 year timescales. Here we present high-resolution records of non-lithogenic metal fluxes within sediment cores covering the last 500,000 years of hydrothermal deposition on the flanks of the Juan de Fuca Ridge. Six adjacent, gridded cores were analyzed by x-ray fluorescence for Fe, Mn, and Cu concentrations, corrected for lithogenic inputs with Ti, and normalized to excess initial 230Th to generate non-lithogenic metal flux records that provide the longest orbitally resolved reconstructions of hydrothermal activity currently available. Fe fluxes vary with global sea level over the last two glacial cycles, suggesting higher hydrothermal deposition during interglacial periods. The observed negative relationship between Fe and Mn indicates variable sediment redox conditions and diagenetic remobilization of sedimentary Mn over time. Thus, Mn fluxes may not be a reliable indicator for hydrothermal activity in the Juan de Fuca Ridge sediment cores. Cu fluxes show substantial high-frequency variability that may be linked to changes in vent temperature related to increased magmatic production during glacial periods. Deglacial hydrothermal peaks on the Juan de Fuca Ridge are consistent with previously published records from the Mid-Atlantic Ridge and the East Pacific Rise. Moreover, on the Juan de Fuca Ridge, the deglacial peaks in hydrothermal activity are followed by relatively high hydrothermal fluxes throughout the ensuing interglacial periods relative to the previous glacial period.

  13. Spatially distinct, temporally stable microbial populations mediate biogeochemical cycling at and below the seafloor in hydrothermal vent fluids. (United States)

    Fortunato, Caroline S; Larson, Benjamin; Butterfield, David A; Huber, Julie A


    At deep-sea hydrothermal vents, microbial communities thrive across geochemical gradients above, at, and below the seafloor. In this study, we determined the gene content and transcription patterns of microbial communities and specific populations to understand the taxonomy and metabolism both spatially and temporally across geochemically different diffuse fluid hydrothermal vents. Vent fluids were examined via metagenomic, metatranscriptomic, genomic binning, and geochemical analyses from Axial Seamount, an active submarine volcano on the Juan de Fuca Ridge in the NE Pacific Ocean, from 2013 to 2015 at three different vents: Anemone, Marker 33, and Marker 113. Results showed that individual vent sites maintained microbial communities and specific populations over time, but with spatially distinct taxonomic, metabolic potential, and gene transcription profiles. The geochemistry and physical structure of each vent both played important roles in shaping the dominant organisms and metabolisms present at each site. Genomic binning identified key populations of SUP05, Aquificales and methanogenic archaea carrying out important transformations of carbon, sulfur, hydrogen, and nitrogen, with groups that appear unique to individual sites. This work highlights the connection between microbial metabolic processes, fluid chemistry, and microbial population dynamics at and below the seafloor and increases understanding of the role of hydrothermal vent microbial communities in deep ocean biogeochemical cycles. © 2017 The Authors. Environmental Microbiology published by Society for Applied Microbiology and John Wiley & Sons Ltd.

  14. Vente d'artisanat

    CERN Document Server

    Staff Associaiton


      Éducation et Libération Vente d’artisanat du Tiers Monde Mardi 22 et mercredi 23 avril 2014 CERN, Bâtiment principal Togo, École Arc en ciel, construction des salles de classe. Appel pour le financement de ce chantier afin de libérer l’école de la charge des loyers payés pendant des années. Après nos réalisations en Amérique latine et au Bénin, nous mobilisons nos efforts pour l’école Arc en ciel de Kpémé, au Togo, sur les bords de l’Océan, à mi-chemin entre Lomé et la frontière entre le Bénin et le Togo. Il s’agit d’une école primaire privée, laïque qui a très bonne réputation en termes de résultats, notamment pour les écoliers en fin de scolar...

  15. Antarctic marine biodiversity and deep-sea hydrothermal vents.

    Directory of Open Access Journals (Sweden)

    Steven L Chown


    Full Text Available The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining.

  16. 33 CFR 165.776 - Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico (United States)


    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico 165.776 Section 165.776 Navigation and Navigable Waters COAST... Guard District § 165.776 Security Zone; Coast Guard Base San Juan, San Juan Harbor, Puerto Rico (a...

  17. Vented Chill / No-Vent Fill of Cryogenic Propellant Tanks (United States)

    Rhys, Noah O.; Foster, Lee W.; Martin, Adam K.; Stephens, Jonathan R.


    Architectures for extended duration missions often include an on-orbit replenishment of the space vehicle's cryogenic liquid propellants. Such a replenishment could be accomplished via a tank-to-tank transfer from a dedicated tanker or a more permanent propellant depot storage tank. Minimizing the propellant loss associated with transfer line and receiver propellant tank thermal conditioning is essential for mass savings. A new methodology for conducting tank-to-tank transfer while minimizing such losses has been demonstrated. Charge-Hold-Vent is the traditional methodology for conducting a tank-to-tank propellant transfer. A small amount of cryogenic liquid is introduced to chill the transfer line and propellant tank. As the propellant absorbs heat and undergoes a phase change, the tank internal pressure increases. The tank is then vented to relieve pressure prior to another charge of cryogenic liquid being introduced. This cycle is repeated until the transfer lines and tank are sufficiently chilled and the replenishment of the propellant tank is complete. This method suffers inefficiencies due to multiple chill and vent cycles within the transfer lines and associated feed system components. Additionally, this system requires precise measuring of cryogenic fluid delivery for each transfer, multiple valve cycling events, and other complexities associated with cycled operations. To minimize propellant loss and greatly simplify on-orbit operations, an alternate methodology has been designed and demonstrated. The Vented Chill / No Vent Fill method is a simpler, constant flow approach in which the propellant tank and transfer lines are only chilled once. The receiver tank is continuously vented as cryogenic liquid chills the transfer lines, tank mass and ullage space. Once chilled sufficiently, the receiver tank valve is closed and the tank is completely filled. Interestingly, the vent valve can be closed prior to receiver tank components reaching liquid saturation

  18. Macrofaunal ecology of sedimented hydrothermal vents in the Bransfield Strait, Antarctica

    Directory of Open Access Journals (Sweden)

    James Benjamin Bell


    Full Text Available Sedimented hydrothermal vents, where hot, mineral-rich water flows through sediment, are poorly understood globally, both in their distribution and the ecology of individual vent fields. We explored macrofaunal community ecology at a sediment-hosted hydrothermal vent in the Southern Ocean. This is the first such study of these ecosystems outside of the Pacific and the furthest south (62˚S of any vent system studied. Sedimentary fauna were sampled in four areas of the Bransfield Strait (Southern Ocean, with the aim of contrasting community structure between vent and non-vent sites. Macrofaunal assemblages were clearly distinct between vent and non-vent sites, and diversity, richness and density declined towards maximum hydrothermal activity. This variation is in contrast to observations from similar systems in the Pacific and demonstrates the influence of factors other than chemosynthetic primary productivity in structuring infauna at deep-sea vent communities. Vent endemic fauna had limited abundance and were represented by a single siboglinid species at hydrothermally active areas, meaning that that the majority of local biota were those also found in other areas. Several taxa occupied all sampling stations but there were large differences in their relative abundances, suggesting communities were structured by niche variation rather than dispersal ability.

  19. Juan de Mairena en Srebrenica


    Sánchez, J. Jorge


    Not available.Dos hilos impulsan estas líneas: la reflexión sobre uno de los acontecimientos cruciales de este fin de siglo en Europa, la masacre de Srebrenica, y la necesidad de contribuir a la tarea colectiva de reconstruir una tradición filosófica en lengua castellana más allá de las clásicas distinciones de géneros. Ambos propósitos confluirían, metonímica y metafóricamente, en un nombre, Machado, y una obra, el Juan de Mairena. Los textos del apócrifo del poeta, tan próximo en algunos mo...

  20. Juan de Mairena en Srebrenica

    Directory of Open Access Journals (Sweden)

    Sánchez, J. Jorge


    Full Text Available Not available.Dos hilos impulsan estas líneas: la reflexión sobre uno de los acontecimientos cruciales de este fin de siglo en Europa, la masacre de Srebrenica, y la necesidad de contribuir a la tarea colectiva de reconstruir una tradición filosófica en lengua castellana más allá de las clásicas distinciones de géneros. Ambos propósitos confluirían, metonímica y metafóricamente, en un nombre, Machado, y una obra, el Juan de Mairena. Los textos del apócrifo del poeta, tan próximo en algunos momentos al pensamiento de Lévinas o Heidegger, pueden contribuir a articular un examen crítico, insertado en una tradición, sobre ese símbolo de nuestra época.

  1. A Feasibility Study of H{sub 2}S Abatement by Incineration of Noncondensable Gases in Vented Steam Flow from Davies-State 5206-1 Geothermal Steam Well, Geysers Geothermal Steam Field, Lake County, California

    Energy Technology Data Exchange (ETDEWEB)



    Determine feasibility of using an incineration-type device to accomplish the required reduction in vent steam H{sub 2}S content to meet ICAPCO rules. This approach is to be the only method considered in this feasibility study.

  2. Graafikatriennaalil osalev Juan Manuel Echavarria saabub Tallinna

    Index Scriptorium Estoniae


    12.-15. aprillini 2011 külastab Tallinna Columbia kunstnik Juan Manuel Echavarria. Tema holograafiliste trükiste sarjast "Reekviem NN" (2008-2010), mida eksponeeritakse Tallinna XV graafikatriennaalil Kumu Kunstimuuseumis

  3. The History of Venting (part I) (United States)

    Leiter, Stephen C.


    Venting techniques and design are an important implementation strategy for observatory and payload contamination control, and yet venting analysis has seen a topsey turvey history, at lease from the perspective of the simple Layman trying to design a black box. Additionally, designing the vent has competing controls from Safety and EMIEMC. In the days of Shuttle, Safety placed liens against the vents of blankets, boxes, and large structural items principally to protect cargo bay vents but also from a flammability perspective. What continues to elude the Designer Community is a stable, simple way of designing vents for black boxes that satisfies everybody. But we continue to try.

  4. Mapping Planetary Volcanic Deposits: Identifying Vents and Distinguishing between Effects of Eruption Conditions and Local Storage and Release on Flow Field Morphology (United States)

    Bleacher, J. E.; Eppler, D. B.; Skinner, J. A.; Evans, C. A.; Feng, W.; Gruener, J. E.; Hurwitz, D. M.; Whitson, P.; Janoiko, B.


    Terrestrial geologic mapping techniques are regularly used for "photogeologic" mapping of other planets, but these approaches are complicated by the diverse type, areal coverage, and spatial resolution of available data sets. When available, spatially-limited in-situ human and/or robotic surface observations can sometimes introduce a level of detail that is difficult to integrate with regional or global interpretations. To assess best practices for utilizing observations acquired from orbit and on the surface, our team conducted a comparative study of geologic mapping and interpretation techniques. We compared maps generated for the same area in the San Francisco Volcanic Field (SFVF) in northern Arizona using 1) data collected for reconnaissance before and during the 2010 Desert Research And Technology Studies campaign, and 2) during a traditional, terrestrial field geology study. The operations, related results, and direct mapping comparisons are discussed in companion LPSC abstracts. Here we present new geologic interpretations for a volcanic cone and related lava flows as derived from all approaches involved in this study. Mapping results indicate a need for caution when interpreting past eruption conditions on other planetary surfaces from orbital data alone.

  5. Mapping Planetary Volcanic Deposits: Identifying Vents and Distingushing between Effects of Eruption Conditions and Local Lava Storage and Release on Flow Field Morphology (United States)

    Bleacher, J. E.; Eppler, D. B.; Skinner, J. A.; Evans, C. A.; Feng, W.; Gruener, J. E.; Hurwitz, D. M.; Whitson, P.; Janoiko, B.


    Terrestrial geologic mapping techniques are regularly used for "photogeologic" mapping of other planets, but these approaches are complicated by the diverse type, areal coverage, and spatial resolution of available data sets. When available, spatially-limited in-situ human and/or robotic surface observations can sometimes introduce a level of detail that is difficult to integrate with regional or global interpretations. To assess best practices for utilizing observations acquired from orbit and on the surface, our team conducted a comparative study of geologic mapping and interpretation techniques. We compared maps generated for the same area in the San Francisco Volcanic Field (SFVF) in northern Arizona using 1) data collected for reconnaissance before and during the 2010 Desert Research And Technology Studies campaign, and 2) during a traditional, terrestrial field geology study. The operations, related results, and direct mapping comparisons are discussed in companion LPSC abstracts [1-3]. Here we present new geologic interpretations for a volcanic cone and related lava flows as derived from all approaches involved in this study. Mapping results indicate a need for caution when interpreting past eruption conditions on other planetary surfaces from orbital data alone.

  6. Field-trip guide to the vents, dikes, stratigraphy, and structure of the Columbia River Basalt Group, eastern Oregon and southeastern Washington (United States)

    Camp, Victor E; Reidel, Stephen P.; Ross, Martin E.; Brown, Richard J.; Self, Stephen


    The Columbia River Basalt Group covers an area of more than 210,000 km2 with an estimated volume of 210,000 km3. As the youngest continental flood-basalt province on Earth (16.7–5.5 Ma), it is well preserved, with a coherent and detailed stratigraphy exposed in the deep canyonlands of eastern Oregon and southeastern Washington. The Columbia River flood-basalt province is often cited as a model for the study of similar provinces worldwide.This field-trip guide explores the main source region of the Columbia River Basalt Group and is written for trip participants attending the 2017 International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly in Portland, Oregon, USA. The first part of the guide provides an overview of the geologic features common in the Columbia River flood-basalt province and the stratigraphic terminology used in the Columbia River Basalt Group. The accompanying road log examines the stratigraphic evolution, eruption history, and structure of the province through a field examination of the lavas, dikes, and pyroclastic rocks of the Columbia River Basalt Group.

  7. Juan Rivano: Un Largo Contrapunto

    Directory of Open Access Journals (Sweden)

    Eduardo Naranjo


    Full Text Available El fin de este artículo es presentar parcialmente el desarrollo intelectual del filósofo y escritor chileno Juan Rivano. La elección de Rivano se ha debido a la importante influencia que ejerció y aún ejerce su pensamiento sobre la sociedad chilena. Este artículo es una invitación a leer con curiosidad filosófica su Largo contrapunto y trambién su extensa producción intelectual. El periodo tratado aquí concluye a fines dela década del 60. Una parte importante de su filosofía se había concentrado en la dialectización de las relaciones sociales su conclusión fue que éste no se resolvería sino que quedaba en forma de dilema. En consecuencia, para él, la filosofía no está vertebrada de conflicto en conflicto, de dilema en dilema sino vertebrada en dilemas.

  8. Stability of Hydrothermal Vent Communities on the Eastern Lau Spreading Center (United States)

    Fisher, C. R.; Du Preez, C.; Ferrini, V. L.; Beinart, R.; Seewald, J.; Hoer, D.; Girguis, P. R.


    With polymetalic sulfide deposit mining imminent in the Western Pacific, understanding the pace and patterns of natural change in the hydrothermal vent communities of the region is critical to the design of pre-mining surveys and post-exploitation monitoring that should accompany responsible resource extraction. The overarching goals of our April 2016 expedition to the Eastern Lau Spreading Center (ELSC) with the RV Falkor, were therefore to significantly increase our understanding of the natural patterns of change in the vent geology, chemistry, and biology along the ELSC, and the processes that govern these changes. During the expedition we were able to revisit 17 community study sites in four vent fields, which were established during the NSF Ridge 2000 program. In each vent field, we acquired high resolution multibeam and spatially explicit chemical data and imagery for photo mosaics of seven chimney, six diffuse flow, and four peripheral vent faunal communities to compare with similar data collected in 2005, 2006 and 2009. Advances in chemical sensor and imaging technology not only facilitate comparisons to the pre-existing data sets, but also provide new insights to the physiological ecology of the fauna and the factors contributing to their realized distribution. Notably, our preliminary analyses have found no evidence of significant volcanic or tectonic activity at any of the sites since 2005. The most surprising observation, however, was the remarkable stability in the community structure and faunal distribution at most of the chimney, diffuse flow, and peripheral community study sites at three of the major vent fields, which showed little evidence of change over the decade that they have been monitored. While the discovery of fauna with chemoautotrophic symbionts at the southern-most vent field visited, Mariner, suggests significant changes in the chemistry of the diffuse flow in this vent field since 2009, the apparent geological and ecological stability

  9. Stereoscopic particle image velocimetry investigations of the mixed convection exchange flow through a horizontal vent (United States)

    Varrall, Kevin; Pretrel, Hugues; Vaux, Samuel; Vauquelin, Olivier


    The exchange flow through a horizontal vent linking two compartments (one above the other) is studied experimentally. This exchange is here governed by both the buoyant natural effect due to the temperature difference of the fluids in both compartments, and the effect of a (forced) mechanical ventilation applied in the lower compartment. Such a configuration leads to uni- or bi-directional flows through the vent. In the experiments, buoyancy is induced in the lower compartment thanks to an electrical resistor. The forced ventilation is applied in exhaust or supply modes and three different values of the vent area. To estimate both velocity fields and flow rates at the vent, measurements are realized at thermal steady state, flush the vent in the upper compartment using stereoscopic particle image velocimetry (SPIV), which is original for this kind of flow. The SPIV measurements allows the area occupied by both upward and downward flows to be determined.

  10. Influence of Hydrodynamics on the Larval Supply to Hydrothermal Vents on the East Pacific Rise

    National Research Council Canada - National Science Library

    Adams, Diane K


    ... that contribute to structuring marine benthic communities. In order to facilitate field studies, this thesis first provides new morphological and genetic identifications for hydrothermal vent gastropod larvae along the northern East Pacific Rise...

  11. Spatial variation of metal bioaccumulation in the hydrothermal vent mussel Bathymodiolus azoricus. (United States)

    Cosson, Richard P; Thiébaut, Eric; Company, Rui; Castrec-Rouelle, Maryse; Colaço, Ana; Martins, Inês; Sarradin, Pierre-Marie; Bebianno, Maria João


    The variability of the bioaccumulation of metals (Ag, Cd, Cu, Fe, Mn and Zn) was extensively studied in the mussel Bathymodiolus azoricus from five hydrothermal vent sites inside three main vent fields of increasing depth along the Mid-Atlantic Ridge: Menez Gwen, Lucky Strike and Rainbow. Metal bioaccumulation varied greatly between vent fields and even between sites inside a vent field with B. azoricus showing a great capacity to accumulate metals. The bioaccumulation of these metals also varied significantly among tissues. The main target was the gills where metals were mainly associated with soluble compounds whereas in the digestive gland they were mainly associated with insoluble compounds. Storage of metals under insoluble forms in B. azoricus seems to be a major pathway for the detoxification of both essential and non-essential metals. Mussels from the studied fields can be discriminated following their metallic load but the segregation relies partially on the composition of the metal-enriched fluids.

  12. Investigations of a novel fauna from hydrothermal vents along the Arctic Mid-Ocean Ridge (AMOR) (Invited) (United States)

    Rapp, H.; Schander, C.; Halanych, K. M.; Levin, L. A.; Sweetman, A.; Tverberg, J.; Hoem, S.; Steen, I.; Thorseth, I. H.; Pedersen, R.


    The Arctic deep ocean hosts a variety of habitats ranging from fairly uniform sedimentary abyssal plains to highly variable hard bottoms on mid ocean ridges, including biodiversity hotspots like seamounts and hydrothermal vents. Deep-sea hydrothermal vents are usually associated with a highly specialized fauna, and since their discovery in 1977 more than 400 species of animals have been described. This fauna includes various animal groups of which the most conspicuous and well known are annelids, mollusks and crustaceans. The newly discovered deep sea hydrothermal vents on the Mohns-Knipovich ridge north of Iceland harbour unique biodiversity. The Jan Mayen field consists of two main areas with high-temperature white smoker venting and wide areas with low-temperature seepage, located at 5-700 m, while the deeper Loki Castle vent field at 2400 m depth consists of a large area with high temperature black smokers surrounded by a sedimentary area with more diffuse low-temperature venting and barite chimneys. The Jan Mayen sites show low abundance of specialized hydrothermal vent fauna. Single groups have a few specialized representatives but groups otherwise common in hydrothermal vent areas are absent. Slightly more than 200 macrofaunal species have been identified from this vent area, comprising mainly an assortment of bathyal species known from the surrounding area. Analysis of stable isotope data also indicates that the majority of the species present are feeding on phytodetritus and/or phytoplankton. However, the deeper Loki Castle vent field contains a much more diverse vent endemic fauna with high abundances of specialized polychaetes, gastropods and amphipods. These specializations also include symbioses with a range of chemosynthetic microorganisms. Our data show that the fauna composition is a result of high degree of local specialization with some similarities to the fauna of cold seeps along the Norwegian margin and wood-falls in the abyssal Norwegian Sea

  13. Autonomous and Remotely Operated Vehicle Technology for Hydrothermal Vent Discovery, Exploration, and Sampling


    Yoerger, Dana; Bradley, Albert; Jakuba, Michael; German, Christopher; Shank, Timothy; TIVEY, Maurice


    Autonomous and remotely operated underwater vehicles play complementary roles in the discovery, exploration, and detailed study of hydrothermal vents. Beginning with clues provided by towed or lowered instruments, autonomous underwater vehicles (AUVs) can localize and make preliminary photographic surveys of vent fields. In addition to finding and photographing such sites, AUVs excel at providing regional context through fine-scale bathymetric and magnetic field mapping. Remotely operated veh...

  14. San Juan Uchucuanicu: évolution historique

    Directory of Open Access Journals (Sweden)


    Full Text Available La communauté de San Juan est reconnue depuis 1939. Une première partie concerne l’organisation de la reducción de San Juan vers le milieu du XVIe siècle. Le poids fiscal s’exerce durement sur le village et la crise est générale dans toute la vallée du Chancay au XVIIe. siècle. La christianisation des habitants est définitive au milieu de ce même siècle. C’est vers la fin du XVIIe siècle et durant tout le XVIIIe que se multiplient les conflits entre San Juan et les villages voisins liés aux terrains de pâture et à la possession de l’eau. La deuxième partie du travail concerne les rapports de la communauté de San Juan avec le Pérou contemporain : contrainte fiscale toujours très lourde durant la fin de l’époque coloniale, exactions des militaires juste avant l’indépendance. La période républicaine voit toujours les conflits avec les villages voisins mais aussi la naissance de familles qui cherchent à retirer le maximum de la communauté. Les terres sont divisées et attribuées : la détérioration de l’organisation communale traditionnelle est manifeste. L4es conflits se multiplient entre petits propriétaires, mais aussi avec les haciendas voisines : c’est l’apparition d’une véritable lutte de classes. La situation actuelle est incertaine, le poids de l’économie marchande se développe avec l’exode des jeunes. Que sera la communauté San Juan à la fin de ce siècle? La comunidad de San Juan está reconocida desde 1939. La primera parte concierne a la organización de la 'reducción' de San Juan hacia mediados del siglo XVI. El peso fiscal se ejerce duramente sobre el pueblo y en el siglo XVII la crisis es general en todo el valle de Chancay. Hacia mediados del mismo siglo la cristianización de los habitantes es definitiva. Es hacia fines del siglo XVII y durante todo el siglo XVIII que se multiplican los conflictos entre San Juan y los pueblos vecinos, los que están relacionados con los terrenos de

  15. Explosive Volcanic Eruptions from Linear Vents on Earth, Venus and Mars: Comparisons with Circular Vent Eruptions (United States)

    Glaze, Lori S.; Baloga, Stephen M.; Wimert, Jesse


    Conditions required to support buoyant convective plumes are investigated for explosive volcanic eruptions from circular and linear vents on Earth, Venus, and Mars. Vent geometry (linear versus circular) plays a significant role in the ability of an explosive eruption to sustain a buoyant plume. On Earth, linear and circular vent eruptions are both capable of driving buoyant plumes to equivalent maximum rise heights, however, linear vent plumes are more sensitive to vent size. For analogous mass eruption rates, linear vent plumes surpass circular vent plumes in entrainment efficiency approximately when L(sub o) > 3r(sub o) owing to the larger entrainment area relative to the control volume. Relative to circular vents, linear vents on Venus favor column collapse and the formation of pyroclastic flows because the range of conditions required to establish and sustain buoyancy is narrow. When buoyancy can be sustained, however, maximum plume heights exceed those from circular vents. For current atmospheric conditions on Mars, linear vent eruptions are capable of injecting volcanic material slightly higher than analogous circular vent eruptions. However, both geometries are more likely to produce pyroclastic fountains, as opposed to convective plumes, owing to the low density atmosphere. Due to the atmospheric density profile and water content on Earth, explosive eruptions enjoy favorable conditions for producing sustained buoyant columns, while pyroclastic flows would be relatively more prevalent on Venus and Mars. These results have implications for the injection and dispersal of particulates into the planetary atmosphere and the ability to interpret the geologic record of planetary volcanism.

  16. Microbial community structure across fluid gradients in the Juan de Fuca Ridge hydrothermal system. (United States)

    Anderson, Rika E; Beltrán, Mónica Torres; Hallam, Steven J; Baross, John A


    Physical and chemical gradients are dominant factors in shaping hydrothermal vent microbial ecology, where archaeal and bacterial habitats encompass a range between hot, reduced hydrothermal fluid and cold, oxidized seawater. To determine the impact of these fluid gradients on microbial communities inhabiting these systems, we surveyed bacterial and archaeal community structure among and between hydrothermal plumes, diffuse flow fluids, and background seawater in several hydrothermal vent sites on the Juan de Fuca Ridge using 16S rRNA gene diversity screening (clone libraries and terminal restriction length polymorphisms) and quantitative polymerase chain reaction methods. Community structure was similar between hydrothermal plumes and background seawater, where a number of taxa usually associated with low-oxygen zones were observed, whereas high-temperature diffuse fluids exhibited a distinct phylogenetic profile. SUP05 and Arctic96BD-19 sulfur-oxidizing bacteria were prevalent in all three mixing regimes where they exhibited overlapping but not identical abundance patterns. Taken together, these results indicate conserved patterns of redox-driven niche partitioning between hydrothermal mixing regimes and microbial communities associated with sinking particles and oxygen-deficient waters. Moreover, the prevalence of SUP05 and Arctic96BD-19 in plume and diffuse flow fluids indicates a more cosmopolitan role for these groups in the ecology and biogeochemistry of the dark ocean. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  17. Sobre el teatro del absurdo (de Juan del Encina a Juan Mateu

    Directory of Open Access Journals (Sweden)

    Serralta, Frédéric


    Full Text Available From the analysis of a few comic devices of the absurd in Don Juan Tenorio «El refugiao» —a parodical play by exiled playwright Juan Mateu, first performed in Toulouse in 1958—, this article aims at showing that a tradition is still alive —a tradition that can, non only be traced back to La venganza de don Mendo by Muñoz Seca (who did not, as has been claimed, invent the theatre of the absurd, but which is also part of an old trend stemming from Juan del Encina's famous Disparates, which has been exemplified by the burlesque plays of the seventeenth century, which was obvious in the nineteenth and early twentieth century popular liking for parodical drama, and which is still today one of the sources of what could be called humour the Spanish way.A partir del análisis de algunos mecanismos cómicos del absurdo en Don Juan Tenorio «El refugiao» —obra paródica del dramaturgo exiliado Juan Mateu estrenada en Toulouse en 1958—, el artículo pretende demostrar la persistencia de una tradición que no se remonta sólo a La venganza de don Mendo de Muñoz Seca (el cual no fue ni mucho menos, como demasiadas veces se ha dicho, el inventor del teatro del absurdo, sino que se inscribe en una vieja trayectoria arraigada en los famosos Disparates de Juan del Encina, ilustrada luego por la comedia burlesca del siglo XVII, patente en la afición popular del XIX y principios del XX al teatro paródico y que todavía hoy es una de las fuentes de lo que se podría llamar un humor «a la española».

  18. Spatial variation in the population structure and reproductive biology of Rimicaris hybisae (Caridea: Alvinocarididae at hydrothermal vents on the Mid-Cayman Spreading Centre.

    Directory of Open Access Journals (Sweden)

    Verity Nye

    Full Text Available The dynamics and microdistribution of faunal assemblages at hydrothermal vents often reflect the fine-scale spatial and temporal heterogeneity of the vent environment. This study examined the reproductive development and population structure of the caridean shrimp Rimicaris hybisae at the Beebe and Von Damm Vent Fields (Mid-Cayman Spreading Centre, Caribbean using spatially discrete samples collected in January 2012. Rimicaris hybisae is gonochoric and exhibits iteroparous reproduction. Oocyte size-frequency distributions (21-823 µm feret diameters varied significantly among samples. Embryo development was asynchronous among females, which may result in asynchronous larval release for the populations. Specimens of R. hybisae from the Von Damm Vent Field (2294 m were significantly larger than specimens from the Beebe Vent Field. Brooding females at Von Damm exhibited greater size-specific fecundity, possibly as a consequence of a non-linear relationship between fecundity and body size that was consistent across both vent fields. Samples collected from several locations at the Beebe Vent Field (4944-4972 m revealed spatial variability in the sex ratios, population structure, size, and development of oocytes and embryos of this mobile species. Samples from the Von Damm Vent Field and sample J2-613-24 from Beebe Woods exhibited the highest frequencies of ovigerous females and significantly female-biased sex ratios. Environmental variables within shrimp aggregations may influence the distribution of ovigerous females, resulting in a spatially heterogeneous pattern of reproductive development in R. hybisae, as found in other vent taxa.

  19. 78 FR 35593 - Special Local Regulation; Christmas Boat Parade, San Juan Harbor; San Juan, PR (United States)


    ... SECURITY Coast Guard 33 CFR Part 100 RIN 1625-AA08 Special Local Regulation; Christmas Boat Parade, San... Juan, Puerto Rico during the Christmas Boat Parade, a Boat Parade. The event is scheduled to take place on Saturday, December 14, 2013. Approximately 35 boats are anticipated to participate in the Boat...

  20. Una Visita al Viejo San Juan (A Visit to Old San Juan). (United States)

    Cabello, Victor; And Others

    Written in Spanish, this black and white illustrated booklet provides a tour of Old San Juan, Puerto Rico's oldest and most historic city. Brief historical information is provided on the Perro de San Jeronimo, a statue of a barking dog found in front of the Castillo; Plaza de Colon, a small plaza dedicated to Christopher Columbus; the Catedral de…

  1. Trique de San Juan Copala, Oaxaca (Trique of San Juan Copala, Oaxaca). (United States)

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Trique, an indigenous language of Mexico spoken in San Juan Copala, in the state of Oaxaca. The objective of collecting such a representative sampling of the…

  2. Chinanteco de San Juan Lealao, Oaxaca (Chinantec of San Juan Lealao, Oaxaca). (United States)

    Mexico Coll. (Mexico City)

    This document is one of 17 volumes on indigenous Mexican languages and is the result of a project undertaken by the Archivo de Lenguas Indigenas de Mexico. This volume contains information on Chinantec, an indigenous language of Mexico spoken in San Juan Lealao, in the state of Oaxaca. The objective of collecting such a representative sampling of…

  3. Juan: a 9-year-old Latino boy with ADHD. (United States)

    DuPaul, George J; Pérez, Victor H; Kuo, Alice; Stein, Martin T


    Juan, a 9-year-old Latino male, was referred to a community clinic by his third-grade teacher for evaluation of classroom behavior problems. He is an only child and lives with both parents. At home, Juan speaks Spanish with his parents although he occasionally speaks English with his father. His father came to the U.S. from Mexico as a small child and completed the 12 grade in the U.S. Juan's mother completed 8 grade in Mexico and immigrated to the U.S. as a teenager.Juan's mother reported that he has had no significant medical problems. Her report of his behavior included an inability to focus on tasks at hand and easy distractibility. She was concerned that the principal of the school mentioned that Juan may be asked to repeat the 3 grade or change schools. In the clinic, Juan sat quietly but appeared to be daydreaming and attentive to the conversation. The pediatrician called the principal who expressed frustration with Juan's behavior. In class, he was very fidgety, did not pay attention and usually did not answer questions. He also bothered other students when they were working. The principal explained that because Juan's school was a Spanish language immersion school, there were no special education services available. If a student at the school required special education services, he or she would be transferred to another school in the same school district. An evaluation for an Individualized Education Plan (IEP) indicated that Juan had above average cognitive ability (90 percentile), with superior ability to problem solve and process information simultaneously (99 percentile). The Woodcock Johnson III (Spanish version) indicated average achievement in academic skills, with low average in reading fluency, comprehension and spelling. On the Test of Auditory-Perceptual Skills, Juan tested generally low average in all domains, and was at the 14 percentile for both auditory number and auditory word memory. On the Test of Visual-Perceptual Skills, Juan scored

  4. 30 CFR 77.304 - Explosion release vents. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Explosion release vents. 77.304 Section 77.304... Dryers § 77.304 Explosion release vents. Drying chambers, dry-dust collectors, ductwork connecting dryers... explosion release vents which open directly to the outside atmosphere, and all such vents shall be: (a...

  5. Juan's Dilemma: A New Twist on the Old Lemon Battery (United States)

    Hunt, Vanessa; Sorey, Timothy; Balandova, Evguenia; Palmquist, Bruce


    When life hands you lemons, make a battery! In this article, the authors describe an activity they refer to as "Juan's Dilemma," an extension of the familiar lemon-battery activity (Goodisman 2001). Juan's Dilemma integrates oxidation and reduction chemistry with circuit theory in a fun, real-world exercise. The authors designed this activity for…

  6. El Arquitecto Juan de Madrazo y Kuntz


    Navascués Palacio, Pedro


    En el panorama de la arquitectura isabelina y procedente de la primera promoción de la Escuela de Arquitectura de Madrid, ocupa un lugar destacado Juan de Madrazo y Kuntz (1829-1880), hijo de José de Madrazo y hermano de Federico, Pedro y Luis de Madrazo. Su vida y obra resultan exiguas, tanto por el corto número de años alcanzados como por los escasos proyectos que llegó a realizar. Mas aquí radica uno de los secretos de la singularidad de su obra, pues ésta deja ver siempre un grado de madu...

  7. Sequence Stratigraphy of the Dakota Sandstone, Eastern San Juan Basin, New Mexico, and its Relationship to Reservoir Compartmentalization

    Energy Technology Data Exchange (ETDEWEB)

    Varney, Peter J.


    This research established the Dakota-outcrop sequence stratigraphy in part of the eastern San Juan Basin, New Mexico, and relates reservoir quality lithologies in depositional sequences to structure and reservoir compartmentalization in the South Lindrith Field area. The result was a predictive tool that will help guide further exploration and development.

  8. 78 FR 50104 - Notice of Inventory Completion: U.S. Department of the Interior, National Park Service, San Juan... (United States)


    ... objects were removed from three prehistoric archeological sites within the boundaries of San Juan Island..., WA, during a summer field school in archeology under the direction of Professor Carroll Burroughs of... osteological analysis, archeological data, geographic context and accession data, the 76 individuals from the...

  9. An Inquiry into Juan Ramon's Interest in Walter Pater

    Directory of Open Access Journals (Sweden)

    John C. Wilcox


    Full Text Available The evidence for Juan Ramon's interest in Pater, which began around 1920 and was still active twenty years later, is discussed in this paper. Pater's view of death and dying and his attitude toward the decadent persona are described in so far as they indicate the spiritual affinity that exists between him and Juan Ramón. Pater's aesthetic idealism, and the presence of similar ideals in Juan Ramon's own work are then examined. The second part of the paper concentrates on the great interest Juan Ramón took in Pater's evocation of the Mona Lisa. The potential impact of the aesthetic idealism inherent in this passage, its Platonism in particular, receives special analysis in the light of Espacio , and in consideration of Juan Ramon's 1943 remark: "I am, have been, and always will be a Platonist."

  10. Modeling and Simulation of Synchronous Threshold in Vent Collective Behavior

    Directory of Open Access Journals (Sweden)

    Yaofeng Zhang


    Full Text Available With the strengthening of the social contradiction, the outbreak of vent collective behavior tends to be frequent. The essence of vent collective behavior is emergence of synchronization. In order to explore the threshold of consensus synchronization in vent collective behavior, a mathematic model and a corresponding simulation model based on multi-agent are proposed. The results of analysis by mean field theory and simulation experiments show the following. (1 There is a threshold Kc for consensus synchronization in global-coupling and homogeneous group, and when the system parameter K is greater than Kc, consensus synchronization emerge. Otherwise the system cannot achieve synchronization. The conclusion is verified by further study of multiagent simulation. (2 Compared with the global-coupling situation, the process of synchronization is delayed in local-coupling and homogeneous group. (3 For local-coupling and heterogeneous group, consensus dissemination can achieve synchronization only when the effects of the parameters meet the threshold requirements of consensus synchronization.

  11. Genomic and population genetic analysis of deep-sea vent chemoautotrophs (United States)

    Nakagawa, S.; Shimamura, S.; Takaki, Y.; Mino, S.; Makita, H.; Sawabe, T.; Takai, K.


    Deep-sea vents are the light-independent, highly productive ecosystems driven primarily by chemoautotrophs. Most of the invertebrates thrive there through their relationship with symbiotic chemoautotrophs. Chemoautotrophs are microorganisms that are able to fix inorganic carbon using a chemical energy obtained through the oxidation of reduced compounds. Following the discovery of deep-sea vent ecosystems in 1977, there has been an increasing knowledge that deep-sea vent chemoautotrophs display remarkable physiological and phylogenetic diversity. Recent microbiological studies have led to an emerging view that the majority of deep-sea vent chemoautotrophs have the ability to derive energy from multiple redox couples other than the conventional sulfur-oxygen couple. Genomic, metagenomic and postgenomic studies have considerably accelerated the comprehensive understanding of molecular mechanisms of deep-sea vent chemoautotrophy, even in unculturable endosymbionts of vent fauna. For example, genomic analysis suggested that there were previously unrecognized evolutionary links between deep-sea vent chemoautotrophs and important human/animal pathogens. However, relatively little is known about the genome of horizontally transmitted endosymbionts. In this study, we sequenced whole genomes of the probably horizontally transmitted endosymbionts of two different gastropod species from a deep-sea hydrothermal field, as an effort to address questions about 1) the genome evolution of horizontally transmitted, facultative endosymbionts, 2) their genomic variability, and 3) genetic differences among symbionts of various deep-sea vent invertebrates. Both endosymbiont genomes display features consistent with ongoing genome reduction such as large proportions of pseudogenes and transposable elements. The genomes encode multiple functions for chemoautotrophic respirations, probably reflecting their adaptation to their niches with continuous changes in environmental conditions. When

  12. Geomicrobiology of sublacustrine thermal vents in Yellowstone Lake: Geochemical controls on microbial community structure and function

    Directory of Open Access Journals (Sweden)

    William P. Inskeep


    Full Text Available Yellowstone Lake (Yellowstone National Park, WY, USA is a large high-altitude (2200 m, fresh-water lake, which straddles an extensive caldera and is the center of significant geothermal activity. The primary goal of this interdisciplinary study was to evaluate the microbial populations inhabiting thermal vent communities in Yellowstone Lake (Yellowstone Lake using 16S rRNA gene and random metagenome sequencing, and to determine how geochemical attributes of vent waters influence the distribution of specific microorganisms and their metabolic potential. Thermal vent waters and associated microbial biomass were sampled during two field seasons (2007 - 2008 using a remotely operated vehicle (ROV. Sublacustrine thermal vent waters (circa 50 - 90 oC contained elevated concentrations of numerous constituents associated with geothermal activity including dissolved hydrogen, sulfide, methane and carbon dioxide. Microorganisms associated with sulfur-rich filamentous ‘streamer’ communities of Inflated Plain and West Thumb (pH range 5 - 6 were dominated by bacteria from the Aquificales, but also contained thermophilic archaea from the Crenarchaeota and Euryarchaeota. Novel groups of methanogens and members of the Korarchaeota were observed in vents from West Thumb and Elliot’s Crater (pH 5 - 6. Conversely, metagenome sequence from Mary Bay vent sediments did not yield large assemblies, and contained diverse thermophilic and nonthermophilic bacterial relatives. Analysis of functional genes associated with the major vent populations indicated a direct linkage to high concentrations of carbon dioxide, reduced sulfur (sulfide and/or elemental S, hydrogen and methane in the deep thermal ecosystems. Our observations show that sublacustrine thermal vents in Yellowstone Lake support novel thermophilic communities, which contain microorganisms with functional attributes not found to date in terrestrial geothermal systems of YNP.

  13. Programa educativo del Infante D. Juan Manuel

    Directory of Open Access Journals (Sweden)

    Marciano SÁNCHEZ


    Full Text Available RESUMEN: Si hemos de creer al Prólogo-Dedicatoria, el infante D. JUAN MANUEL parece que se sentía muy preocupado por los problemas de su tiempo, hasta el punto de que le hacían «perder el dormir». Como terapia contra este insomnio utilizaba el leer y escribir. En consecuencia, si el origen de este Libro del cauallero et del escudero, calificado por Díaz Plaja como «curiosa enciclopedia didáctica de su tiempo», hay que buscarlo en las noches de insomnio que padecía en Sevilla, es lícito concluir que los temas educativos constituían una preocupación para el Infante. Si bien no es tanto un tratado sistemático de educación cuanto una «fabliella» —género literario de la época que funde lo novelesco y lo didáctico— da pautas suficientes para, de una parte, deducir cuál sería el método de educación imperante entre los nobles junto con sus principales contenidos educativos, y, de otra, inferir el sistema ideal para don Juan Manuel.

  14. Juan Antonio Rubio Rodriguez (1944 – 2010)

    CERN Multimedia

    His colleagues and friends


    It was with deep sorrow and great sadness that we learnt that Juan Antonio Rubio Rodriguez had passed away on 16th January 2010. Juan Antonio was born in Madrid on 4th June 1944, and received his Ph. D. in Physics in 1971 from“Universidad Complutense de Madrid”. He was a CERN Fellow (1968 – 1971) and subsequently worked at JEN (currently CIEMAT) as a researcher (1971 – 1976). He was leader of the HEP group (1977 – 1981), leader of the Nuclear and Particle Physics Division (1981 – 1983), Director for Basic Research (1983 – 1987) and Scientific Director (1984 – 1987). He was instrumental in the Spanish accession to CERN approved by the Spanish Government at the end of 1982 and ratified by the Spanish Parliament in June 1983. He served at CERN (1987 – 2004) as Group Leader (1987 – 1990), Scientific Advisor to the Director-General (1990 – 2000) and as Division Leader of the Education and Technology T...

  15. Thermal Constraints on Upper Basement Permeability Near a Venting Seamount (United States)

    Hutnak, M.; Fisher, A. T.; Zuehlsdorff, L.; Spiess, V.


    We used transient numerical simulations of coupled heat and fluid transport to quantify relations between fluid fluxes, basement permeability, and the vigor of local convection on seafloor heat flow patterns adjacent to a basement outcrop through which warm hydrothermal fluids are discharged. These finite-element models are designed to replicate conditions near the Baby Bare outcrop on 3.5-Ma seafloor on the eastern flank of the Juan de Fuca Ridge, where 5-20 L/s of warm fluid seeps from the seafloor. Several transects of heat flow observations co-located along seismic reflection profiles around this feature provide observational constraints for the models. Heat flow is not greatly influenced by venting at the outcrop at distances of several kilometers from the point of sediment onlap, but values rise abruptly immediately adjacent to the outcrop. The model domain consisted of a 21 km x 5 km radial grid, with 8 sedimentary and 6 basalt units, and a characteristic node spacing of 20-500 meters. Conductive simulations include a small rise in heat flow near the outcrop as a result of conductive refraction, but the magnitude of the rise is much smaller than observed. Additional simulations were run using elevated basement thermal conductivity as a proxy for local convection, to evaluate the vigor of local convection required to generate large increases in heat flow near the outcrop. Nusselt numbers (the ratio of heat transported within the edifice by conduction and advection to that which would be transported by conduction alone) of 100 10-10m2), and this convection is as effective at redistributing heat as single-pass flow in which little or no local convection occurs.

  16. VentDB: A Global Online Synthesis Database of Seafloor Hydrothermal Spring Geochemistry (United States)

    Mottl, M. J.; Lehnert, K. A.; Johansson, A. K.; Hsu, L.


    Chemical data for seafloor hydrothermal springs are fundamental to the study of mid-ocean ridge and seafloor processes, ocean water chemistry, and global geochemical cycles, as well as vent ecosystems and the sub-seafloor biosphere. So far, these data have been accessible only in the scientific literature or in online data catalogs where they are widely dispersed in individual data tables, and are often insufficiently documented for re-use. We have developed VentDB as an online data system for geochemical data for hydrothermal springs that will facilitate access and analysis of these data. VentDB uses the concept and architecture of the popular PetDB database for seafloor igneous and metamorphic rock geochemistry ( to provide easy and fast access to a global synthesis of seafloor hydrothermal spring geochemical data. The VentDB database contains concentrations of major and trace species, dissolved gases, and radiogenic and isotopic ratios for hydrothermal vents on the seafloor. Further chemical or physical properties of hydrothermal springs can be included in the future if desired. The database comprises both the calculated hydrothermal end-member solution compositions as estimated by extrapolation of the concentrations of individual chemical species to a Mg concentration of zero, and the raw data for hydrothermal solution samples as collected, where available. Data quality is documented by including information for the raw analytical data about the analytical method, precision, and reference material measurements, and quality control parameters for end-member compositions including the lowest Mg measured in any sample, the number of samples and correlation coefficient of the linear regression, and the charge balance for the extrapolated zero-Mg composition. The database also includes information about the sampled locations (geospatial coordinates, vent or vent field names, names of other physiographic features), temperature, flow and vent type

  17. Eruptive and tectonic history of the Endeavour Segment, Juan de Fuca Ridge, based on AUV mapping data and lava flow ages (United States)

    Clague, David A.; Dreyer, Brian M; Paduan, Jennifer B; Martin, Julie F; Caress, David W; Gillespie, James B.; Kelley, Deborah S; Thomas, Hans; Portner, Ryan A; Delaney, John R; Guilderson, Thomas P.; McGann, Mary L.


    High-resolution bathymetric surveys from autonomous underwater vehicles ABE and D. Allan B. were merged to create a coregistered map of 71.7 km2 of the Endeavour Segment of the Juan de Fuca Ridge. Radiocarbon dating of foraminifera in cores from three dives of remotely operated vehicle Doc Ricketts provide minimum eruption ages for 40 lava flows that are combined with the bathymetric data to outline the eruptive and tectonic history. The ages range from Modern to 10,700 marine-calibrated years before present (yr BP). During a robust magmatic phase from >10,700 yr BP to ~4300 yr BP, flows erupted from an axial high and many flowed >5 km down the flanks; some partly buried adjacent valleys. Axial magma chambers (AMCs) may have been wider than today to supply dike intrusions over a 2 km wide axial zone. Summit Seamount formed by ~4770 yr BP and was subsequently dismembered during a period of extension with little volcanism starting ~4300 yr BP. This tectonic phase with only rare volcanic eruptions lasted until ~2300 yr BP and may have resulted in near-solidification of the AMCs. The axial graben formed by crustal extension during this period of low magmatic activity. Infrequent eruptions occurred on the flanks between 2620–1760 yr BP and within the axial graben since ~1750 yr BP. This most recent phase of limited volcanic and intense hydrothermal activity that began ~2300 yr BP defines a hydrothermal phase of ridge development that coincides with the present-day 1 km wide AMCs and overlying hydrothermal vent fields.

  18. El rastro de juan Preciado entre los mundos mestizos de Juan Rulfo


    Palaisi-Robert, Marie-Agnès


    19 pages; Ya no es para desmostrar que la obra de Juan Rulfo tiene un interés a la vez regional y universal. Sin embargo , si tomamos el término "universal" en el sentido de"comprension del uiverso, esta obra todavia tiene mucho que revelarnos. En este articulo, demuestro que la novela "Pedro Paramo" presenta una cosmovision que se enraiza en los mundos prehispanicos, y que es una herencia que Rulfo tambien desarolla en su obra fotografica.

  19. Characterization of vent fauna at the Mid-Cayman Spreading Center (United States)

    Plouviez, Sophie; Jacobson, Alixandra; Wu, Mengyou; Van Dover, Cindy L.


    Hydrothermal vents in the deep sea have a global distribution on mid-ocean ridges and comprise at least six biogeographic provinces. A geographically isolated vent system was recently discovered on the Mid-Cayman Spreading Center (MCSC). Here, we describe the faunal assemblages associated with this system and their relationship to known biogeographic provinces. Taxa from MCSC vents were sorted based on morphology and barcoded using the cytochrome oxidase I (COI) and 16S ribosomal RNA (16S) genes for identification. Distinct faunal assemblages were recognized around vent chimneys at two hydrothermal vent fields (Von Damm and Beebe) separated by a distance of ~13 km and >2.5-km depth along the Mid-Cayman Spreading Center. These results suggest that depth and/or local conditions structure faunal assemblages in this region. COI and microsatellite markers were then used to explore the genetic structure of the shrimp Rimicaris hybisae, the only abundant species shared between the shallow Von Damm and the deep Beebe vent fields. R. hybisae was not genetically differentiated between the Von Damm Spire and Beebe chimneys, suggesting this species is better adapted for bathymetric dispersal and the differences in local conditions than other MCSC species. In addition, a third faunal assemblage dominated by two species of tubeworms was identified at Von Damm in association with weakly diffuse flow sites (including the site known as "Marker X18"). The Marker X18 assemblage shares species with seeps in the region. Fauna shared with both vents and seeps at the MCSC reinforces the need for a global biogeographic study of deep-sea chemosynthetic fauna that is not focused on specific habitats.

  20. Is the Juan Fernandez Ridge (nazca Plate) a Deep-Mantle Hot SPOT Trail? (United States)

    Lara, L. E.; Selles, D.; Díaz, A.; Piña-Gauthier, M.


    The Juan Fernández Ridge on the oceanic Nazca plate is thought to be a classic hot spot trail because of the apparent westward rejuvenation of the eruptive ages. Geochronological data is still scarce to prove this is the case, and other hypothesis should be taken into account. There are a few constrains, like the ca. 9 Ma Ar-Ar age of the O'Higgins seamount (115 km from the Chile-Perú trench), published K-Ar ages of ca. 3-4 Ma in Robinson Crusoe island (580 km from the trench) and ca. 1 Ma in Alejandro Selkirk (180 km further west). New reconnaissance K-Ar ages in Robinson Crusoe yield ca. 1-3 Ma, which partially overlap with the age of Alejandro Selkirk, breaking the expected age progression given that the Nazca plate moves eastwards at ca. 6-8 cm/yr. New geological mapping also shows a sharp unconformity between the older, strongly altered sequences and more recent, post-erosional volcanic piles, where only the vent facies have disappeared. A fixed deep-mantle plume origin for Pacific hot spots has been widely debated and concurrent phenomena arose as a possible explanation for non-linear age progressions and/or long-lived volcanic activity. In fact, intraplate regional tectonics, plume displacement, and mantle heterogeneities could be the main factor of the ridge architecture or the mask for a first-order linear trend. An ongoing mapping and dating effort is aimed to understand the evolution of the Juan Fernández Ridge, testing the main hypothesis. Fondecyt grant 110966 is acknowledged for financial support.

  1. Wind tunnel investigation of the Titan Forward Skirt compartment vent from a free-stream Mach number of 0.80 to 1.96. [conducted in the Lewis Research Center 8 by 6 foot supersonic wind tunnel (United States)

    Johns, A. L.


    A test was conducted to determine the flow characteristics of the Titan forward skirt compartment vent over a free stream Mach number range of 0.80 to 1.96. The vent was mounted in a flat plate and the plate was flush mounted to the tunnel side wall with coinciding center lines. Air was discharged from a duct, located on the tunnel side wall behind the plate, through a canted aft 30 deg honeycomb vent into the free stream. Data for the analysis of the Titan forward skirt compartment venting during ascent through the atmosphere are provided. Full scale simulated flight hardware, such as the honeycomb vent, duct corrugations and field joint ring were used. Boundary layer thicknesses were used to vary boundary height. The highest vent discharge coefficient for any given Mach number and vent pressure ratio generally occurred at the maximum displacement thickness. With no vent flow the static pressure in the vent region was generally less than the free stream static pressure. With vent flow, the static pressures upstream of the vent increased, and those downstream of the vent decreased.

  2. Juan Valdez: Resurgimiento de una marca


    Arias Daza, Daniela Alejandra; Gutiérrez Delgadillo, María Camila


    La Federación Nacional de Cafeteros fue fundada en el año 1927 con el objetivo de elevar el nivel de vida de los caficultores y dar a conocer la calidad del café Colombiano en el mundo. Parte del trabajo de la federación ha sido el posicionamiento a nivel mundial del café Colombiano, para lo cual ha utilizado varias campañas publicitarias entre las cuales se destaca la creación en el año 1959 del icono Juan Valdez con su mula Conchita. Así mismo, en noviembre del año 2002 la Federación Nac...

  3. Juan Guas en la Catedral de Segovia

    Directory of Open Access Journals (Sweden)

    López Díez, María


    Full Text Available Juan Guas, one of the most active stone masons of the second half of the 15th century, worked in Segovia for 20 years (1471-1491, where he participated in the construction of the Cathedral and other buildings in the city. Thus Segovia is a necessary place of reference for the study of this master. In this article the participation of Guas in the building of the Cathedral is analyzed from the documental point of view through the different contracts he signed with the Cathedral chapter. These documents allow for the evaluation of the progressive consolidation of Guas in the exercise of his profession, and are of great interest for the better understanding of artistic practice during his day.

    Juan Guas es uno de los canteros más activos de la segunda mitad del siglo XV. Durante veinte años (1471-1491 trabajó en Segovia, donde participó en la construcción de la catedral y en otros edificios de la misma ciudad, siendo Segovia un lugar de referencia obligada en la investigación sobre el maestro. El presente artículo analiza, desde un punto de vista documental, la participación de Guas en las obras de la catedral a través de los diferentes contratos que firmó con el cabildo catedralicio. Estos permiten evaluar la progresiva consolidación de Guas en el ejercicio de su profesión, de gran interés para el mejor conocimiento de la práctica artística de su época.

  4. On Small Disturbance Ascent Vent Behavior (United States)

    Woronowicz, Michael


    As a spacecraft undergoes ascent in a launch vehicle, its ambient pressure environment transitions from one atmosphere to high vacuum in a matter of a few minutes. Venting of internal cavities is necessary to prevent the buildup of pressure differentials across cavity walls. These pressure differentials are often restricted to low levels to prevent violation of container integrity. Such vents usually consist of fixed orifices, ducts, or combinations of both. Duct conductance behavior is fundamentally different from that for orifices in pressure driven flows governing the launch vehicle ascent depressurization environment. Duct conductance is governed by the average pressure across its length, while orifice conductance is dictated by a pressure ratio. Hence, one cannot define a valid equivalent orifice for a given duct across a range of pressure levels. This presentation discusses development of expressions for these two types of vent elements in the limit of small pressure differentials, explores conditions for their validity, and compares their features regarding ascent depressurization performance.

  5. Vents et nuages la physique du ciel

    CERN Document Server


    Les nuages et les vents sont au cœur des attentions des climatologues et des météorologues. Les premiers s’intéressent à leurs interactions avec le réchauffement climatique. Les seconds cherchent à prédire le temps qu’il fera demain, mais aussi les manifestations extrêmes (tornades, orages, cyclones…). Un numéro pour rester le nez au vent et la tête dans les nuages !

  6. San Juan, Puerto Rico Tsunami Forecast Grids for MOST Model (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The San Juan, Puerto Rico Forecast Model Grids provides bathymetric data strictly for tsunami inundation modeling with the Method of Splitting Tsunami (MOST) model....

  7. Strait of Juan de Fuca 36 arc-second DEM (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 36-second Strait of Juan de Fuca Washington Elevation Grid provides bathymetric data in ASCII raster format of 36-second resolution in geographic coordinates....

  8. Strait of Juan de Fuca 1 arc-second DEM (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The 1-second Strait of Juan de Fuca Washington Elevation Grid provides bathymetric data in ASCII raster format of 1-second resolution in geographic coordinates. This...

  9. 77 FR 47358 - San Juan National Forest Resource Advisory Committee (United States)


    ... inspect comments received at or the Public Reading Room, San Juan Public... II. Anyone who would like to bring related matters to the attention of the committee may file written...

  10. Distribution of bacteria and associated minerals in the gill chamber of the vent shrimp Rimicaris exoculata and related biogeochemical processes


    Zbinden, M.; Le Bris, Nadine; Gaill, F.; Compere, P


    The shrimp Rimicaris exoculata dominates the megafauna of some Mid-Atlantic Ridge hydrothermal vent fields. This species harbours a rich bacterial epibiosis inside its gill chamber. At the 'Rainbow' vent site (36degrees 14.0'N), the epibionts are associated with iron oxide deposits. Investigation of both bacteria and minerals by scanning electron microscopy (SEM) and X-ray microanalysis (EDX) revealed 3 distinct compartments in the gill chamber: (1) the lower pre-branchial chamber, housing ba...

  11. Protection Island and San Juan Islands National Wildlife Refuges: Comprehensive Conservation Plan and San Juan Islands Wilderness Stewardship Plan (United States)

    US Fish and Wildlife Service, Department of the Interior — This Comprehensive Conservation Plan (CCP) was written to guide management on Protection Island and San Juan Islands NWRs for the next 15 years. This plan outlines...

  12. Preoperational test report, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.


    This represents a preoperational test report for Vent Building Ventilation Systems, Project W-030. Project W-030 provides a ventilation upgrade for the four Aging Waste Facility tanks. The system provides Heating, Ventilation, and Air Conditioning (HVAC) for the W-030 Ventilation Building. The tests verify correct system operation and correct indications displayed by the central Monitor and Control System.

  13. Crystal structure of Deep Vent DNA polymerase. (United States)

    Hikida, Yasushi; Kimoto, Michiko; Hirao, Ichiro; Yokoyama, Shigeyuki


    DNA polymerases are useful tools in various biochemical experiments. We have focused on the DNA polymerases involved in DNA replication including the unnatural base pair between 7-(2-thienyl)imidazo[4,5-b]pyridine (Ds) and 2-nitro-4-propynylpyrrole (Px). Many reports have described the different combinations between unnatural base pairs and DNA polymerases. As an example, for the replication of the Ds-Px pair, Deep Vent DNA polymerase exhibits high efficiency and fidelity, but Taq DNA polymerase shows much lower efficiency and fidelity. In the present study, we determined the crystal structure of Deep Vent DNA polymerase in the apo form at 2.5 Å resolution. Using this structure, we constructed structural models of Deep Vent DNA polymerase complexes with DNA containing an unnatural or natural base in the replication position. The models revealed that the unnatural Ds base in the template-strand DNA clashes with the side-chain oxygen of Thr664 in Taq DNA polymerase, but not in Deep Vent DNA polymerase. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  14. Summary of measurements with MicroVent

    DEFF Research Database (Denmark)

    Dreau, Jerome Le; Heiselberg, Per Kvols; Jensen, Rasmus Lund

    This summary presents the main results when MicroVent is used in the cooling case, without heat recovery. Experiments have thus been performed with relatively low inlet air temperature (below 15°C). Different solutions have been compared to decrease the risk of draught in the occupied zone: ‐ using...

  15. Using Spatial Density to Characterize Volcanic Fields on Mars (United States)

    Richardson, J. A.; Bleacher, J. E.; Connor, C. B.; Connor, L. J.


    We introduce a new tool to planetary geology for quantifying the spatial arrangement of vent fields and volcanic provinces using non parametric kernel density estimation. Unlike parametricmethods where spatial density, and thus the spatial arrangement of volcanic vents, is simplified to fit a standard statistical distribution, non parametric methods offer more objective and data driven techniques to characterize volcanic vent fields. This method is applied to Syria Planum volcanic vent catalog data as well as catalog data for a vent field south of Pavonis Mons. The spatial densities are compared to terrestrial volcanic fields.

  16. 40 CFR 63.1425 - Process vent control requirements. (United States)


    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process vent control requirements. 63... control requirements. (a) Applicability of process vent control requirements. For each process vent at an... process changes occur, in accordance with the provisions of § 63.1428(g). No control requirements apply to...

  17. 46 CFR 182.450 - Vent pipes for fuel tanks. (United States)


    ... requirements of this section. (g) Where a flexible vent pipe section is necessary, suitable flexible tubing or... by clamps. The flexible section must be accessible and as near the upper end of the vent pipe as... 46 Shipping 7 2010-10-01 2010-10-01 false Vent pipes for fuel tanks. 182.450 Section 182.450...

  18. 46 CFR 119.450 - Vent pipes for fuel tanks. (United States)


    ... screens or arrester elements. (e) Where a flexible vent pipe section is necessary, suitable flexible... each end by clamps. The flexible section must be accessible and as near the upper end of the vent pipe... 46 Shipping 4 2010-10-01 2010-10-01 false Vent pipes for fuel tanks. 119.450 Section 119.450...

  19. 40 CFR 63.1406 - Reactor batch process vent provisions. (United States)


    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Reactor batch process vent provisions... § 63.1406 Reactor batch process vent provisions. (a) Emission standards. Owners or operators of reactor... reactor batch process vent located at a new affected source shall control organic HAP emissions by...

  20. Las Silvas de Juan Lorenzo Palmireno

    Directory of Open Access Journals (Sweden)

    Lee, Lilith


    Full Text Available This paper examines the works titled Silva by Juan Lorenzo Palmireno. The analysis of these texts sheds light on Palmireno’s understanding of the word and its possible implications in the sixteenth century. The study identifies an interpretation of silva as a way of writing different from his predecessor, Pedro Mexía, who first used it to title his work Silva de varia lección twenty years ago. The lack of any intention to arrange its structure gives these silvas the characteristic of a literary draft, a feature derived from one of the meanings of silva inherited from the Classical Age. Moreover, Palmireno’s works reveal an encyclopedic project of which the miscellany (represented by silva forms a part. Furthermore, the silvas of Palmireno act as a transition to the later development of silva as a genre, which finds its educational objective being taken over gradually by the anxiety to provide entertainment.El artículo examina las obras tituladas Silva de Juan Lorenzo Palmireno. El análisis de estos textos deja constancia de cómo el humanista entiende la palabra y sus implicaciones en el siglo XVI. El estudio identifica una interpretación de silva como una manera de escribir distinta de su predecesor, Pedro Mexía, quien veinte años antes la utilizó para nombrar a su obra Silva de varia lección. La falta de la intención en ordenar los textos les otorga a las silvas palmirenianas la característica de un borrador literario, uno de los significados de la silva desde la Edad Clásica. Además, las obras del humanista aragonés muestra su proyecto enciclopédico del autor que integra la miscelánea (representada por la silva como una parte. Estas silvas también actúan como la transición para el desarrollo de la silva como género que encuentra su objetivo educacional sustituido gradualmente por la finalidad de ofrecer entretenimiento.

  1. Portada de la iglesia de San Juan Bautista en Las Cabezas de San Juan, Sevilla

    Directory of Open Access Journals (Sweden)

    Juan A. Fernández Naranjo


    Full Text Available La restauración de la Portada de la Iglesia de San Juan Bautista responde al tipo de intervención modesta en su presupuesto pero ambiciosa en su riguroso planteamiento metodológico. El autor nos expone cómo a través de las obras de intervención fueron descubriendo los datos que atesoraba esta portada barroca realizada, con gran dominio del ofi­cio, en ladrillo. Especial interés merece sobre todo el tratamiento del color.

  2. The sound generated by mid-ocean ridge black smoker hydrothermal vents.

    Directory of Open Access Journals (Sweden)

    Timothy J Crone

    Full Text Available Hydrothermal flow through seafloor black smoker vents is typically turbulent and vigorous, with speeds often exceeding 1 m/s. Although theory predicts that these flows will generate sound, the prevailing view has been that black smokers are essentially silent. Here we present the first unambiguous field recordings showing that these vents radiate significant acoustic energy. The sounds contain a broadband component and narrowband tones which are indicative of resonance. The amplitude of the broadband component shows tidal modulation which is indicative of discharge rate variations related to the mechanics of tidal loading. Vent sounds will provide researchers with new ways to study flow through sulfide structures, and may provide some local organisms with behavioral or navigational cues.

  3. Modeling mid-ocean ridge hydrothermal response to earthquakes, tides, and ocean currents: a case study at the Grotto mound, Endeavour Segment, Juan de Fuca Ridge (United States)

    Xu, G.; Bemis, K. G.


    Seafloor hydrothermal systems feature intricate interconnections among oceanic, geological, hydrothermal, and biological processes. The advent of the NEPTUNE observatory operated by Ocean Networks Canada at the Endeavour Segment, Juan de Fuca Ridge enables scientists to study these interconnections through multidisciplinary, continuous, real-time observations. The multidisciplinary observatory instruments deployed at the Grotto Mound, a major study site of the NEPTUNE observatory, makes it a perfect place to study the response of a seafloor hydrothermal system to geological and oceanic processes. In this study, we use the multidisciplinary datasets recorded by the NEPTUNE Observatory instruments as observational tools to demonstrate two different aspects of the response of hydrothermal activity at the Grotto Mound to geological and oceanic processes. First, we investigate a recent increase in venting temperature and heat flux at Grotto observed by the Benthic and Resistivity Sensors (BARS) and the Cabled Observatory Vent Imaging Sonar (COVIS) respectively. This event started in Mar 2014 and is still evolving by the time of writing this abstract. An initial interpretation in light of the seismic data recorded by a neighboring ocean bottom seismometer on the NEPTUNE observatory suggests the temperature and heat flux increase is probably triggered by local seismic activities. Comparison of the observations with the results of a 1-D mathematical model simulation of hydrothermal sub-seafloor circulation elucidates the potential mechanisms underlying hydrothermal response to local earthquakes. Second, we observe significant tidal oscillations in the venting temperature time series recorded by BARS and the acoustic imaging of hydrothermal plumes by COVIS, which is evidence for hydrothermal response to ocean tides and currents. We interpret the tidal oscillations of venting temperature as a result of tidal loading on a poroelastic medium. We then invoke poroelastic

  4. Getting the bigger picture: Using precision Remotely Operated Vehicle (ROV) videography to acquire high-definition mosaic images of newly discovered hydrothermal vents in the Southern Ocean (United States)

    Marsh, Leigh; Copley, Jonathan T.; Huvenne, Veerle A. I.; Tyler, Paul A.; Isis ROV Facility


    Direct visual observations from submersible vehicles at hydrothermal vents typically only reveal a fraction of the vent environment at any one time. We describe the use of precision Remotely Operated Vehicle (ROV) videography to produce extensive mosaic images of hydrothermal vent chimneys and surrounding seafloor areas (c. 250 m2), with sufficient resolution to determine distributions of macro- and megafauna. Doppler velocity log navigation (DVLNAV) was used to follow overlapping vertical survey lines in a fixed plane facing a vent chimney, while acquiring high-definition video imagery using a forward-looking camera. The DVLNAV also enabled the vehicle to follow overlapping horizontal survey lines while acquiring seafloor imagery from a downward-looking video camera and mapping variations in seawater temperature. Digital stills images extracted from video were used to compile high-resolution composite views of the surveyed areas. Applying these image acquisition techniques at vent fields on the East Scotia Ridge, Southern Ocean, revealed consistent patterns of faunal zonation around vent sources, variations in proportions of faunal assemblage types on different faces of a vent chimney, and differences in proportions of faunal assemblages between two different vent fields. The technique can therefore be used to determine the composition and spatial distribution of fauna across complex areas of topography, such as vent fields, where mosaic images of vertical structures cannot currently be acquired using other platforms such as autonomous underwater vehicles (AUVs). These image acquisition techniques, demonstrated here in the first ROV dives at newly discovered vent fields, may offer an appropriate technology for rapid baseline studies required by the potential mining of seafloor massive sulfides (SMS).

  5. Active positioning of vent larvae at a mid-ocean ridge (United States)

    Mullineaux, L. S.; McGillicuddy, D. J.; Mills, S. W.; Kosnyrev, V. K.; Thurnherr, A. M.; Ledwell, J. R.; Lavelle, J. W.


    The vertical position of larvae of vent species above a mid-ocean ridge potentially has a strong effect on their dispersal. Larvae may be advected upward in the buoyant vent plume, or move as a consequence of their buoyancy or by active swimming. Alternatively, they may be retained near the bottom by the topography of the axial trough, or by downward swimming. At vents near 9°50'N on the axis of the East Pacific Rise, evidence for active larval positioning was detected in a comparison between field observations of larvae in the plankton in 2006 and 2007 and distributions of non-swimming larvae in a two-dimensional bio-physical model. In the field, few vent larvae were collected at the level of the neutrally buoyant plume (~75 m above the bottom); their relative abundances at that height were much lower than those of simulated larvae from a near-bottom release in the model. This discrepancy was observed for many vent species, particularly gastropods, suggesting that they may actively remain near the bottom by sinking or swimming downward. Near the seafloor, larval abundance decreased from the ridge axis to 1000 m off axis much more strongly in the observations than in the simulations, again pointing to behavior as a potential regulator of larval transport. We suspect that transport off axis was reduced by downward-moving behavior, which positioned larvae into locations where they were isolated from cross-ridge currents by seafloor topography, such as the walls of the axial valley—which are not resolved in the model. Cross-ridge gradients in larval abundance varied between gastropods and polychaetes, indicating that behavior may vary between taxonomic groups, and possibly between species. These results suggest that behaviorally mediated retention of vent larvae may be common, even for species that have a long planktonic larval duration and are capable of long-distance dispersal.

  6. JUAN LUIS SEGUNDO (1925-1976

    Directory of Open Access Journals (Sweden)

    Eduardo Hoornaert


    Full Text Available Juan Luís Segundo era um teólogo que sabia o que queria. Enquanto a maioria de seus colegas ensinava em seminários ou institutos de teologia, assessorava bispos ou encontros de clero, trabalhava com os assim chamados agentes de pastoral, engajava se nas "pastorais especiais", escrevia para revistas de divulgação pastoral, - sempre apoiados na plataforma da instituição grande -, ele ficou organizando seus seminários com leigos não-tão-pobres em Montevidéu, longe do mundo hierárquico, com uma metodologia que ele mesmo descreveu nas palavras introdutórias de sua "Teologia aberta para o leigo adulto" (1976/1, 10-12: seminários em fim-de-semana, com duração de dois ou três dias, divididos em blocos de quatro horas de concentração na seguinte seqüência, aliás bem conhecida: uma conferência inicial de quarenta minutos, grupos de reflexão por uma hora, mesa redonda, reflexão final pelo assessor, e depois oração.

  7. JUAN LUIS SEGUNDO (1925-1976

    Directory of Open Access Journals (Sweden)

    Eduardo Hoornaert


    Full Text Available Juan Luís Segundo era um teólogo que sabia o que queria. Enquanto a maioria de seus colegas ensinava em seminários ou institutos de teologia, assessorava bispos ou encontros de clero, trabalhava com os assim chamados agentes de pastoral, engajava se nas "pastorais especiais", escrevia para revistas de divulgação pastoral, - sempre apoiados na plataforma da instituição grande -, ele ficou organizando seus seminários com leigos não-tão-pobres em Montevidéu, longe do mundo hierárquico, com uma metodologia que ele mesmo descreveu nas palavras introdutórias de sua "Teologia aberta para o leigo adulto" (1976/1, 10-12: seminários em fim-de-semana, com duração de dois ou três dias, divididos em blocos de quatro horas de concentração na seguinte seqüência, aliás bem conhecida: uma conferência inicial de quarenta minutos, grupos de reflexão por uma hora, mesa redonda, reflexão final pelo assessor, e depois oração.


    Directory of Open Access Journals (Sweden)

    Silvia Méndez-Anchía


    Full Text Available Tomando como base la lectura del cuento "Juan Sin Miedo" realizada por tres sujetos adolescentes, pretendo responder a la pregunta sobre los principales temores que enfrenta la población costarricense adolescente en la actualidad. Las respuestas giran en torno a tres núcleos significativos: el miedo a la exclusión económica y social, materializada en el trato discriminatorio hacia quienes no se adecuan a los criterios impuestos por la sociedad de consumo; el miedo a la escuela, en tanto excluye a quienes no se ajustan a la norma esperada de desempeño académico; y el miedo al otro, en particular a la calle y la escuela como espacios de violencia. Concluyo señalando que, detrás de dichos temores, es posible leer un anhelo de pertenencia; de aprecio sincero y gratuito, en que no medie el rendimiento académico de la persona; así como un anhelo de seguridad en el entorno cercano.

  9. Juan Bautista Perolli. Obras genovesas. II

    Directory of Open Access Journals (Sweden)

    López Torrijos, Rosa


    Full Text Available In this article the study of Perolli's work in Genoa is continued, demonstrating his varied artistic activities and his relationship with families under Spanish influence. His last work in Genoa (the Spinola Chapel in the church of San Francisco had to be completed by other artists because Perolli was engaged by Don Alvaro de Bazán to work in his Spanish palace of El Viso. In December 1574, Bazán paid Perolli's debts and shortly afterwards Juan Bautista left for Spain.

    Continúa el estudio de la obra de Perolli en Génova, mostrando su participación en trabajos de arquitectura, escultura y pintura para varias familias genovesas, todas ellas relacionadas con España. Se estudia también su última obra realizada en Génova, la capilla Spinola de la iglesia de San Francisco, desaparecida y totalmente desconocida hasta ahora. Este último trabajo queda interrumpido en diciembre de 1574 cuando don Álvaro de Bazán paga las deudas de Perolli para que éste venga a España a trabajar en el palacio del Viso.

  10. Ecology and biogeography of megafauna and macrofauna at the first known deep-sea hydrothermal vents on the ultraslow-spreading Southwest Indian Ridge (United States)

    Copley, J. T.; Marsh, L.; Glover, A. G.; Hühnerbach, V.; Nye, V. E.; Reid, W. D. K.; Sweeting, C. J.; Wigham, B. D.; Wiklund, H.


    The Southwest Indian Ridge is the longest section of very slow to ultraslow-spreading seafloor in the global mid-ocean ridge system, but the biogeography and ecology of its hydrothermal vent fauna are previously unknown. We collected 21 macro- and megafaunal taxa during the first Remotely Operated Vehicle dives to the Longqi vent field at 37° 47‧S 49° 39‧E, depth 2800 m. Six species are not yet known from other vents, while six other species are known from the Central Indian Ridge, and morphological and molecular analyses show that two further polychaete species are shared with vents beyond the Indian Ocean. Multivariate analysis of vent fauna across three oceans places Longqi in an Indian Ocean province of vent biogeography. Faunal zonation with increasing distance from vents is dominated by the gastropods Chrysomallon squamiferum and Gigantopelta aegis, mussel Bathymodiolus marisindicus, and Neolepas sp. stalked barnacle. Other taxa occur at lower abundance, in some cases contrasting with abundances at other vent fields, and δ13C and δ15N isotope values of species analysed from Longqi are similar to those of shared or related species elsewhere. This study provides baseline ecological observations prior to mineral exploration activities licensed at Longqi by the United Nations.

  11. Investigating the Relationship between Fin Whales, Zooplankton Concentrations and Hydrothermal Venting on the Juan de Fuca Ridge (United States)


    1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Investigating the Relationship between Fin Whales ...Developing an automatic algorithm to track fin whales using data from a small-scale seafloor seismic network. 2. Tracking vocalizing fin whales above...acoustical data show that the zooplankton concentrations are higher at all depths. 3. Estimating the density of calling fin whales above ocean bottom

  12. Sediment Microbial Diversity of Three Deep-Sea Hydrothermal Vents Southwest of the Azores. (United States)

    Cerqueira, Teresa; Pinho, Diogo; Froufe, Hugo; Santos, Ricardo S; Bettencourt, Raul; Egas, Conceição


    Menez Gwen, Lucky Strike and Rainbow are the three most visited and well-known deep-sea hydrothermal vent fields in the Azores region, located in the Mid-Atlantic Ridge. Their distinct geological and ecological features allow them to support a diversity of vent communities, which are largely dependent on Bacteria and Archaea capable of anaerobic or microaerophilic metabolism. These communities play important ecological roles through chemoautotrophy, feeding and in establishing symbiotic associations. However, the occurrence and distribution of these microbes remain poorly understood, especially in deep-sea sediments. In this study, we provide for the first time a comparative survey of the sediment-associated microbial communities from these three neighbouring vent fields. Sediment samples collected in the Menez Gwen, Lucky Strike and Rainbow vent fields showed significant differences in trace-metal concentrations and associated microbiomes. The taxonomic profiles of bacterial, archaeal and eukaryotic representatives were assessed by rRNA gene-tag pyrosequencing, identified anaerobic methanogens and microaerobic Epsilonproteobacteria, particularly at the Menez Gwen site, suggesting sediment communities potentially enriched in sub-seafloor microbes rather than from pelagic microbial taxa. Cosmopolitan OTUs were also detected mostly at Lucky Strike and Rainbow sites and affiliated with the bacterial clades JTB255, Sh765B-TzT-29, Rhodospirillaceae and OCS155 marine group and with the archaeal Marine Group I. Some variations in the community composition along the sediment depth were revealed. Elemental contents and hydrothermal influence are suggested as being reflected in the composition of the microbial assemblages in the sediments of the three vent fields. Altogether, these findings represent valuable information for the understanding of the microbial distribution and potential ecological roles in deep-sea hydrothermal fields.

  13. Food-web complexity across hydrothermal vents on the Azores triple junction (United States)

    Portail, Marie; Brandily, Christophe; Cathalot, Cécile; Colaço, Ana; Gélinas, Yves; Husson, Bérengère; Sarradin, Pierre-Marie; Sarrazin, Jozée


    The assessment and comparison of food webs across various hydrothermal vent sites can enhance our understanding of ecological processes involved in the structure and function of biodiversity. The Menez Gwen, Lucky Strike and Rainbow vent fields are located on the Azores triple junction of the Mid-Atlantic Ridge. These fields have distinct depths (from 850 to 2320 m) and geological contexts (basaltic and ultramafic), but share similar faunal assemblages defined by the presence of foundation species that include Bathymodiolus azoricus, alvinocarid shrimp and gastropods. We compared the food webs of 13 faunal assemblages at these three sites using carbon and nitrogen stable isotope analyses (SIA). Results showed that photosynthesis-derived organic matter is a negligible basal source for vent food webs, at all depths. The contribution of methanotrophy versus autotrophy based on Calvin-Benson-Bassham (CBB) or reductive tricarboxylic acid (rTCA) cycles varied between and within vent fields according to the concentrations of reduced compounds (e.g. CH4, H2S). Species that were common to vent fields showed high trophic flexibility, suggesting weak trophic links to the metabolism of chemosynthetic primary producers. At the community level, a comparison of SIA-derived metrics between mussel assemblages from two vent fields (Menez Gwen & Lucky Strike) showed that the functional structure of food webs was highly similar in terms of basal niche diversification, functional specialization and redundancy. Coupling SIA to functional trait approaches included more variability within the analyses, but the functional structures were still highly comparable. These results suggest that despite variable environmental conditions (physico-chemical factors and basal sources) and faunal community structure, functional complexity remained relatively constant among mussel assemblages. This functional similarity may be favoured by the propensity of species to adapt to fluid variations and


    DEFF Research Database (Denmark)

    Tocho, Claudia; Miranda, Silvia; Pacino, Maria Cristina


    A high-resolution and high-precision detailed gravimetric geoid has been computed for San Juan province in Argentina, ranging from 27 degrees S to 34 degrees S in latitude and 72 degrees W to 65 degrees W in longitude. The gravimetric geoid was calculated using the RTM method, a multiband spherical...... Stokes Fast Fourier Transformation, and the removerestore technique for the spherical harmonic reference field and the terrain. As an external evaluation, the gravimetric quasigeoid/geoid was compared to the geoid heights obtained from 90 GPS/levelling points available for the province. Finally, a GPS...

  15. Distribution, abundance, and diversity patterns of the thermoacidophilic Deep-sea Hydrothermal Vent Euryarchaeota 2 (DHVE2.

    Directory of Open Access Journals (Sweden)

    Gilberto E Flores


    Full Text Available Cultivation-independent studies have shown that taxa belonging to the Deep-sea Hydrothermal Vent Euryarchaeota 2 (DHVE2 lineage are widespread at deep-sea hydrothermal vents. While this lineage appears to be a common and important member of the microbial community at vent environments, relatively little is known about their overall distribution and phylogenetic diversity. In this study, we examined the distribution, relative abundance, co-occurrence patterns, and genetic diversity of cultivable thermoacidophilic DHVE2 in deposits from globally distributed vent fields. Results of quantitative polymerase chain reaction assays with primers specific for the DHVE2 and Archaea demonstrate the ubiquity of the DHVE2 at deep-sea vents and suggest that they are significant members of the archaeal communities of established vent deposit communities. Local similarity analysis of pyrosequencing data revealed that the distribution of the DHVE2 was positively correlated with ten other Euryarchaeota phylotypes and negatively correlated with mostly Crenarchaeota phylotypes. Targeted cultivation efforts resulted in the isolation of 12 axenic strains from six different vent fields, expanding the cultivable diversity of this lineage to vents along the East Pacific Rise and Mid-Atlantic Ridge. Eleven of these isolates shared greater than 97% 16S rRNA gene sequence similarity with one another and the only described isolate of the DHVE2, Aciduliprofundum boonei T469T. Sequencing and phylogenetic analysis of five protein-coding loci, atpA, EF-2, radA, rpoB, and secY, revealed clustering of isolates according to geographic region of isolation. Overall, this study increases our understanding of the distribution, abundance, and genetic diversity of the DHVE2.

  16. Testing Geyser Models using Down-vent Data (United States)

    Wang, C.; Munoz, C.; Ingebritsen, S.; King, E.


    Geysers are often studied as an analogue to magmatic volcanoes because both involve the transfer of mass and energy that leads to eruption. Several conceptual models have been proposed to explain geyser eruption, but no definitive test has been performed largely due to scarcity of down-vent data. In this study we compare simulated time histories of pressure and temperature against published data for the Old Faithful geyser in the Yellowstone National Park and new down-vent measurements from geysers in the El Tatio geyser field of northern Chile. We test two major types of geyser models by comparing simulated and field results. In the chamber model, the geyser system is approximated as a fissure-like conduit connected to a subsurface chamber of water and steam. Heat supplied to the chamber causes water to boil and drives geyser eruptions. Here the Navier-Stokes equation is used to simulate the flow of water and steam. In the fracture-zone model, the geyser system is approximated as a saturated fracture zone of high permeability and compressibility, surrounded by rock matrix of relatively low permeability and compressibility. Heat supply from below causes pore water to boil and drives geyser eruption. Here a two-phase form of Darcy's law is assumed to describe the flow of water and steam (Ingebritsen and Rojstaczer, 1993). Both models can produce P-T time histories qualitatively similar to field results, but the simulations are sensitive to assumed parameters. Results from the chamber model are sensitive to the heat supplied to the system and to the width of the conduit, while results from the fracture-zone model are most sensitive to the permeability of the fracture zone and the adjacent wall rocks. Detailed comparison between field and simulated results, such as the phase lag between changes of pressure and temperature, may help to resolve which model might be more realistic.

  17. Filtered Containment Venting - latest developments in Spain

    Energy Technology Data Exchange (ETDEWEB)

    Zieger, T.


    Introduction: The containment of a Nuclear Power Plant (NPP) is the last barrier for the release of radioactive substances to the environment. The “Status Report on Filtered Containment Venting” [1] states the following: In case of a Severe Accident the containment can be pressurized with a pressure exceeding its failure pressure. In order to keep the containment intact de-pressurization should be possible. To protect the environment against contamination with fission products filtration of the released gas is recommended. Filtered containment venting (FCV) is an additional option to protect the containment and the facility while mitigating radioactivity releases to the environment. The Fukushima Daiichi NPP’s accident demonstrated that in the absence of alternatives to reduce the containment pressure build-up due to steam and incondensable gas accumulation during an accident, the venting of the containment becomes an essential accident management measure for the preservation of its structural integrity... (Author)

  18. Provisions for containment venting in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, J.G.


    In this short paper an overlook is given of the systems developed in Germany for filtered containment venting and their implementation in nuclear power plants. More information on the development can be found in the Proceedings of the DOE/NRC Aircleaning Conferences. In Germany, 28.8 % of the electric energy is produced by 19 nuclear power reactors. No new power reactor is expected to be built at least within the next ten years, but France and Germany cooperate in the development of a future European Power Reactor (ERP). This reactor type will be fitted with a core catcher and passive cooling in order to avoid serious consequences of a hypothetical core meltdown accident so that provisions for containment venting are not required. 3 refs., 6 figs., 1 tab.

  19. Comparative Study of Vented vs. Unvented Crawlspaces

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Kaushik [ORNL; Christian, Jeffrey E [ORNL; Gehl, Anthony C [ORNL


    There has been a significant amount of research in the area of building energy efficiency and durability. However, well-documented quantitative information on the impact of crawlspaces on the performance of residential structures is lacking. The objective of this study was to evaluate and compare the effects of two crawlspace strategies on the whole-house performance of a pair of houses in a mixed humid climate. These houses were built with advanced envelope systems to provide energy savings of 50% or more compared to traditional 2010 new construction. One crawlspace contains insulated walls and is sealed and semi-conditioned. The other is a traditional vented crawlspace with insulation in the crawlspace ceiling. The vented (traditional) crawlspace contains fiberglass batts installed in the floor chase cavities above the crawl, while the sealed and insulated crawlspace contains foil-faced polyisocyanurate foam insulation on the interior side of the masonry walls. Various sensors to measure temperatures, heat flux through crawlspace walls and ceiling, and relative humidity were installed in the two crawlspaces. Data from these sensors have been analyzed to compare the performance of the two crawlspace designs. The analysis results indicated that the sealed and insulated crawlspace design is better than the traditional vented crawlspace in the mixed humid climate.

  20. The spatial scale of genetic subdivision in populations of Ifremeria nautilei, a hydrothermal-vent gastropod from the southwest Pacific

    Directory of Open Access Journals (Sweden)

    Thaler Andrew D


    Full Text Available Abstract Background Deep-sea hydrothermal vents provide patchy, ephemeral habitats for specialized communities of animals that depend on chemoautotrophic primary production. Unlike eastern Pacific hydrothermal vents, where population structure has been studied at large (thousands of kilometres and small (hundreds of meters spatial scales, population structure of western Pacific vents has received limited attention. This study addresses the scale at which genetic differentiation occurs among populations of a western Pacific vent-restricted gastropod, Ifremeria nautilei. Results We used mitochondrial and DNA microsatellite markers to infer patterns of gene flow and population subdivision. A nested sampling strategy was employed to compare genetic diversity in discrete patches of Ifremeria nautilei separated by a few meters within a single vent field to distances as great as several thousand kilometres between back-arc basins that encompass the known range of the species. No genetic subdivisions were detected among patches, mounds, or sites within Manus Basin. Although I. nautilei from Lau and North Fiji Basins (~1000 km apart also exhibited no evidence for genetic subdivision, these populations were genetically distinct from the Manus Basin population. Conclusions An unknown process that restricts contemporary gene flow isolates the Manus Basin population of Ifremeria nautilei from widespread populations that occupy the North Fiji and Lau Basins. A robust understanding of the genetic structure of hydrothermal vent populations at multiple spatial scales defines natural conservation units and can help minimize loss of genetic diversity in situations where human activities are proposed and managed.

  1. Biodiversity and biogeography of hydrothermal vent species in the western Pacific: a biological perspective of TAIGA project (United States)

    Seo, M.; Watanabe, H.; Nakamura, M.; Sasaki, T.; Ogura, T.; Yahagi, T.; Takahashi, Y.; Ishibashi, J.; Kojima, S.


    Deep-sea hydrothermal vents are scientifically interesting environments where strong interactions of geology, chemistry, and biology can be observed. The hydrothermal vents are geologically controlled in association with magmatic activities while diversity of chemicals (such as hydrogen sulfide) contained in hydrothermal fluid is controlled by geochemical interaction between heated seawater and surrounding rocks. In addition to those geological and chemical characters of hydrothermal vents, high biomasses of chemosynthetic community have been known around many vents since the first discovery in the 1970s. To understand the unique system and diversity of biological communities associated with vents is highly valuable in geological, chemical, and biological sciences. As an activity of the research project "TAIGA (Trans-crustal Advection & In-situ bio-geochemical processes of Global sub-seafloor Aquifer)" (Representative: Tetsuro Urabe, Department of Earth & Planetary Science, the University of Tokyo), we analyzed population structures and connectivity as well as larval ecology of various hydrothermal vent species in the Okinawa Trough and the Mariana Trough in an attempt to estimate faunal transitional history associated with hydrothermal activities. The specimens analyzed in the present study were collected by R/V Yokosuka with manned submersible Shinkai6500 and R/V Natsushima with ROV Hyper-Dolphin during YK10-11 and NT11-20 cruises, respectively. In the Mariana Trough (YK10-11), benthic and planktonic faunas were investigated by multiple sampling and use of plankton samplers in three hydrothermal vents (Snail, Archaean, and Urashima-Pika fields). Faunal compositions were then compared as well as size compositions and genetic diversities of major vent species among local populations. In the Okinawa Trough (NT11-20), multiple quantitative sampling was made with simultaneous environmental measurements at more than two sites in five hydrothermal vents (Minami

  2. Thermal Grid 2000/2001: An Examination of the Thermal Flux From a 3.5 km Length of the Endeavour Segment, Juan de Fuca Ridge (United States)

    Johnson, H. P.; Hautala, S. L.


    Two Thermal Grid cruises in 2000/2001 used the ROV Jason to quantify diffuse hydrothermal venting over a 3.5 km along-strike length of the Endeavour axial valley, an area that includes two large hydrothermal fields (MEF and High Rise) and many smaller, isolated diffuse systems. A systematic near-bottom survey was first made using ROV-mounted CTDs, particulate and O2 sensors, to identify sites of diffuse venting. We also deployed the ROV-mounted SM2000 scanning sonar during, and the data provided the highest resolution bathymetric map made to date, with sub-meter pixels and 10 cm vertical resolution. The SM2000 data was also used to produce AST (acoustic scintillation tomography) images, where the acoustic de-correlation between adjacent sonar pings identified areas of hydrothermal fluid venting. In areas of high AST de-correlation (warm water vents), we deployed MAV current meters and thermistors to acquire data on vertical thermal flux over both long (9 month) and short (24 hr) intervals. Data from these cruises allows us to (a) determine vertical thermal flux through the seafloor in vent areas, (b) discover a large number of circular magnetization lows across the valley floor, which overlie active or extinct hydrothermal vent fields, (c) collect temperature and ADCP data to measure seawater entrainment around a high temperature vent, (d) define regions of diffuse fluid vents with the AST method, (e) make long-term measurements of fluid flow variability due to crustal and tidal processes, and (f) use CTD and near-bottom magnetometer data in the discovery of several new and extinct hydrothermal fields on west axial valley wall, providing new constraints regarding crustal fluid circulation. * including C. Jones, M.A. Tivey, M. Pruis, I. Garcia-Berdeal, L. Gilbert, J. Voight, W. Fredericks, T. Bjorkland, T. Kurokawa, M. Tsurumi, S. Bolton, L. Thomas, K. O'Connell, J. Turner, J. Howland and the entire Jason Group.

  3. VentPlan: a ventilator-management advisor.


    Rutledge, G.; Thomsen, G.; Farr, B.; Tovar, M.; Sheiner, L.; Fagan, L.


    VentPlan assists physicians, nurses, and respiratory therapists in the management of artificial respiration for critically ill patients in the intensive-care unit (ICU). VentPlan interprets clinical observations, monitored data, and arterial-blood-gas analyses to make recommendations for setting the ventilator. The VentPlan interface allows users to examine the physiologic model, to inspect details of the data on which the model is based, and to exercise the model to try out different ventila...

  4. 40 CFR 264.1032 - Standards: Process vents. (United States)


    ... operator of a facility with process vents associated with distillation, fractionation, thin-film evaporation, solvent extraction, or air or steam stripping operations managing hazardous wastes with organic...

  5. Bacterial diversity and successional patterns during biofilm formation on freshly exposed basalt surfaces at diffuse-flow deep-sea vents

    Directory of Open Access Journals (Sweden)

    Lara K. Gulmann


    Full Text Available Many deep-sea hydrothermal vent systems are regularly impacted by volcanic eruptions, leaving fresh basalt where abundant animal and microbial communities once thrived. After an eruption, microbial biofilms are often the first visible evidence of biotic re-colonization. The present study is the first to investigate microbial colonization of newly exposed basalt surfaces in the context of vent fluid chemistry over an extended period of time (4 to 293 days by deploying basalt blocks within an established diffuse-flow vent at the 9o50’N vent field on the East Pacific Rise (EPR. Additionally, samples obtained after a recent eruption at the same vent field allowed for comparison between experimental results and those from natural microbial re-colonization. Over 9 months, the community changed from being composed almost exclusively of Epsilonproteobacteria to a more diverse assemblage, corresponding with a potential expansion of metabolic capabilities. The process of biofilm formation appears to generate similar surface-associated communities within and across sites by selecting for a subset of fluid-associated microbes, via species sorting. Furthermore, the high incidence of shared operational taxonomic units (OTUs over time and across different vent sites suggests that the microbial communities colonizing new surfaces at diffuse-flow vent sites might follow a predictable successional pattern.

  6. Las Cabezas de San Juan, Nature Reserve (El Faro). (United States)

    P. L. Weaver; J. L. Ram¡rez; J. L. Coll


    The 178-hectarea(ha) northeastern tip of Puerto Rico, Which is known locally as "Las Cabezas de San Juan Nature Reserve", is managed by the Puerto Rican Conservation Trust to protect the area's scenic beauty and to provide enviromental education and research opportunities to the island's resident and visitors

  7. Dialectical conception of culture in Juan Marinello Vidaurreta

    Directory of Open Access Journals (Sweden)

    Andria Torres-Guerra


    Full Text Available The theoretical problems related to the culture in Cuba have always had special attention in the traditions of thinking. In his context, the work of Juan Marinello offers a vision about the culture with a deep philosophical character.

  8. The green areas of San Juan, Puerto Rico (United States)

    O.M. Ramos-Gonzalez


    Green areas, also known as green infrastructure or urban vegetation, are vital to urbanites for their critical roles in mitigating urban heat island effects and climate change and for their provision of multiple ecosystem services and aesthetics. Here, I provide a high spatial resolution snapshot of the green cover distribution of the city of San Juan, Puerto Rico, by...

  9. El silencio como estrategia en la obra de Juan Rulfo


    Gómez López-Quiñones, Loreto


    Juan Rulfo utiliza el silencio como un espacio para oír y decir mejor en el contexto del México postrevolucionario. Inspirándonos en la terminología de Spivak, pretendemos mostrar el silencio de Rulfo como una estrategia de resistencia ante la representación occidental del Otro.

  10. Pyranocoumarins from Zosima absinthifolia (Vent) Link roots. (United States)

    Razavi, Seyed Mehdi; Imanzadeh, Gholamhasan; Jahed, Fatemeh Soghra; Zarrini, Gholamreza


    Zosima absinthifolia (Vent) Link (Apiaceae) is a perennial herb indigenous to Iran. It has been used as a medicinal plant from ancient time in Iran, Turkey and Pakistan. In the present work, air-dried and powdered plant roots were extracted with n-hexane, dichloromethane and methanol, respectively, using Soxhlet apparatus. The dichloromethane extract was subjected to vacuum liquid chromatography (VLC) and preparative thin layer chromatography (P-TLC) to yield two pyranocoumarins, aegelinol and agasyllin. The antimicrobial assay was performed using agar dilution method. The results showed that purified compounds have modest to weak antibacterial and antifungal activity.

  11. Exposition-vente - French version only

    CERN Multimedia


    Vendredi 7 mai 2004 au CERN : Exposition-vente d'artisanat et de produits du Niger en faveur des femmes et des enfants nigériens de 08h30 à 16h00 à côté du Restaurant No 1 (Novae) Venez nombreux ! Association Suisse-Niger case postale 524 1211 Genève 4 tél. et fax : 011 320.99.75 Compte de chèques postaux : 70-395231-8

  12. MAVEN Contamination Venting and Outgassing Analysis (United States)

    Petro, Elaine M.; Hughes, David W.; Secunda, Mark S.; Chen, Philip T.; Morrissey, James R.; Riegle, Catherine A.


    Mars Atmosphere and Volatile EvolutioN (MAVEN) is the first mission to focus its study on the Mars upper atmosphere. MAVEN will study the evolution of the Mars atmosphere and climate, by examining the conduit through which the atmosphere has to pass as it is lost to the upper atmosphere. An analysis was performed for the MAVEN mission to address two distinct concerns. The first goal of the analysis was to perform an outgassing study to determine where species outgassed from spacecraft materials would redistribute to and how much of the released material might accumulate on sensitive surfaces. The second portion of the analysis serves to predict what effect, if any, Mars atmospheric gases trapped within the spacecraft could have on instrument measurements when re-released through vents. The re-release of atmospheric gases is of interest to this mission because vented gases from a higher pressure spacecraft interior could bias instrument measurements of the Mars atmosphere depending on the flow rates and directions.

  13. Helium as a tracer for fluids released from Juan de Fuca lithosphere beneath the Cascadia forearc (United States)

    McCrory, Patricia A.; Constantz, James E.; Hunt, Andrew G.; Blair, James Luke


    The ratio between helium isotopes (3He/4He) provides an excellent geochemical tracer for investigating the sources of fluids sampled at the Earth's surface. 3He/4He values observed in 25 mineral springs and wells above the Cascadia forearc document a significant component of mantle-derived helium above Juan de Fuca lithosphere, as well as variability in 3He enrichment across the forearc. Sample sites arcward of the forearc mantle corner (FMC) generally yield significantly higher ratios (1.2-4.0 RA) than those seaward of the corner (0.03-0.7 RA). The highest ratios in the Cascadia forearc coincide with slab depths (40-45 km) where metamorphic dehydration of young oceanic lithosphere is expected to release significant fluid and where tectonic tremor occurs, whereas little fluid is expected to be released from the slab depths (25-30 km) beneath sites seaward of the corner.Tremor (considered a marker for high fluid pressure) and high RA values in the forearc are spatially correlated. The Cascadia tremor band is centered on its FMC, and we tentatively postulate that hydrated forearc mantle beneath Cascadia deflects a significant portion of slab-derived fluids updip along the subduction interface, to vent in the vicinity of its corner. Furthermore, high RA values within the tremor band just arcward of the FMC, suggest that the innermost mantle wedge is relatively permeable.Conceptual models require: (1) a deep fluid source as a medium to transport primordial 3He; (2) conduits through the lithosphere which serve to speed fluid ascent to the surface before significant dilution from radiogenic 4He can occur; and (3) near lithostatic fluid pressure to keep conduits open. Our spatial correlation between high RA values and tectonic tremor provides independent evidence that tremor is associated with deep fluids, and it further suggests that high pore pressures associated with tremor may serve to keep fractures open for 3He migration through ductile upper mantle and lower crust.

  14. Vented piston seal prevents fluid leakage between two chambers (United States)

    Mac Glashan, W. F.; Morrison, R.


    To prevent fluid leakage around piston seals separating two fluids under differential pressure, a venting system has been devised. Two methods may be used for venting seals through internal passages to an external low-pressure area, O-ring or split-ring seals.

  15. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.


    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  16. [The examination of men's wits by Juan Huarte de San Juan, and the dawn of the neurobiology of intelligence in the Spanish renaissance]. (United States)

    Martín-Araguz, A; Bustamante-Martínez, C

    The Spanish renaissance doctor Juan Huarte de San Juan (1529-1588) was the author of a unique and immortal work, The Examination of Men's Wits, the edition princeps of which was printed in Baeza in 1575. Since then it has been reprinted at least 80 times and translated into seven languages, which makes it the most influential Spanish contribution to medicine ever published. In this paper we review the unjustly little-known figure of Huarte as the founder of Neuropsychology, and we also analyse his works from a historical and neuroscientific point of view. Huarte's writings deal with the problem of the organic relations between the brain and understanding, and accept the possible influences exerted by temper on the will within the field of the Neurobiology of Intelligence. Thus, over four centuries ago Huarte became the founder of Differential or Physiological Psychology, Neuropsychology, Eugenics and Career Guidance. Huarte's work not only played a fundamental role in the history and development of the body of neuroscientific knowledge, but has also been a clear (although not always cited) influence on scientists, philosophers and men of letters such as Alarcón, Bacon, Cabanis, Cervantes (whose Don Quixote was inspired by him), Charron, Chomsky, Gall, Goethe, Hume, Kant, Kretchmer, Lessing, Lope de Vega, Montaigne, Montesquieu, Nietzsche, Quevedo, Rousseau, Schopenhauer, Thomasius, Tirso de Molina and Ziegler. In the middle of the 16th century, Huarte and his Examination of Men's Wits, together with the works of the naturalist philosophers Gómez Pereira (Antoniana Margarita, 1554) and Miguel Sabuco (New Philosophy, 1587), constituted the prestigious triumvirate of Spanish Renaissance scholars who, for the first time in history, contemplated the workings of the brain from a point of view that had more to do with science than the supernatural.

  17. Differences in recovery between deep-sea hydrothermal vent and vent-proximate communities after a volcanic eruption

    NARCIS (Netherlands)

    Gollner, S.; Govenar, B.; Martinez Arbizu, P.; Mills, S.; Le Bris, N.; Weinbauer, M.; Shank, T.M.; Bright, M.


    Deep-sea hydrothermal vents and the surrounding basalt seafloor are subject to major natural disturbance events such as volcanic eruptions. In the near future, anthropogenic disturbance in the form of deep-sea mining could also significantly affect the faunal communities of hydrothermal vents. In

  18. Deep-Sea Hydrothermal-Vent Sampler (United States)

    Behar, Alberto E.; Venkateswaran, Kasthur; Matthews, Jaret B.


    An apparatus is being developed for sampling water for signs of microbial life in an ocean hydrothermal vent at a depth of as much as 6.5 km. Heretofore, evidence of microbial life in deep-sea hydrothermal vents has been elusive and difficult to validate. Because of the extreme conditions in these environments (high pressures and temperatures often in excess of 300 C), deep-sea hydrothermal- vent samplers must be robust. Because of the presumed low density of biomass of these environments, samplers must be capable of collecting water samples of significant volume. It is also essential to prevent contamination of samples by microbes entrained from surrounding waters. Prior to the development of the present apparatus, no sampling device was capable of satisfying these requirements. The apparatus (see figure) includes an intake equipped with a temperature probe, plus several other temperature probes located away from the intake. The readings from the temperature probes are utilized in conjunction with readings from flowmeters to determine the position of the intake relative to the hydrothermal plume and, thereby, to position the intake to sample directly from the plume. Because it is necessary to collect large samples of water in order to obtain sufficient microbial biomass but it is not practical to retain all the water from the samples, four filter arrays are used to concentrate the microbial biomass (which is assumed to consist of particles larger than 0.2 m) into smaller volumes. The apparatus can collect multiple samples per dive and is designed to process a total volume of 10 L of vent fluid, of which most passes through the filters, leaving a total possibly-microbe-containing sample volume of 200 mL remaining in filters. A rigid titanium nose at the intake is used for cooling the sample water before it enters a flexible inlet hose connected to a pump. As the water passes through the titanium nose, it must be cooled to a temperature that is above a mineral

  19. Adding prefilters to French containment venting systems

    Energy Technology Data Exchange (ETDEWEB)

    Kaercher, M.V. [Electricite de France (EDF), 75 - Paris (France); Boissieu, P. de


    To avoid the need for extra biological shielding round the sand-bed filters in its Pressurized Water Reactor containment venting systems, Electricite de France is installing prefilters. The sand-bed filters filters installed on all French PWRs were intended to retain the source term of radioactivity for 24 hours after the beginning of a core meltdown. But because of its size the sand filter is outside the containment and therefore the source term, which may be inside the sand filter, could produce very high radiation levels on site. To solve this problem a prefilter has been designed. This is to be located inside the containment and aims to retain the source term there. (Author).

  20. Controlled source electromagnetic study on the response of cold vent sites and gas hydrate occurrences on the northern Cascadia margin (United States)

    Gehrmann, R.; Schwalenberg, K.; Riedel, M.; Dosso, S. E.; Mir, R. A.; Edwards, R. N.


    The northern Cascadia margin offshore Vancouver Island is an accretionary sedimentary prism with abundant fluid seepage including cold vents. Cold vents represent gas-rich fluid conduits that often reach the seafloor, contain gas hydrates and support large chemo-synthetic communities. Fluids rise pervasively through the sediments and locally through fault and fracture networks from as far down as the subducting plate to the seafloor. Transported gases may result locally in high amounts of gas hydrate within the upper few tens of meters below the seafloor. The controlled source electromagnetic (CSEM) method is sensitive to resistivity contrasts and therefore to free gas and hydrate accumulations. Our data were acquired with the electric dipole-dipole CSEM configuration built at the University of Toronto that is especially designed to detect resistive anomalies close to the seafloor. We utilize 1-D data inversion and model parameter uncertainty analysis, as well as complementary information from seismic, bathymetry and borehole data. Our data were acquired near the prominent vent site Bullseye, as well as close to the shelf at the edge of the gas hydrate stability field. We analyze the 3-D effect of vents on the CSEM response through forward modeling of a variety of vent models and compare the results to our data. We conclude with a geological interpretation for the upper few hundred meters of the sediment section on the middle and upper slope of the northern Cascadia margin.

  1. Un contrato inédito de Juan de Juanes. El retablo de la Cofradía de la Sangre de Cristo de Valencia (1539

    Directory of Open Access Journals (Sweden)

    Gómez-Ferrer, Mercedes


    Full Text Available This article is based on an unpublished contract signed in 1539 by Vicente and Juan Macip for an altarpiece for the Valencian Brotherhood of the Blood of Christ. The agreement stipulates that Juan, later known as Juan de Juanes, had to paint the scenes. Thus the document reinforces the hypothesis that Juan Macip was the most important painter in the Macip workshop during the 1530’s. It also fills a documental void in between the completion of the Silversmith’s Guild altarpiece (1534-1539 and the contract for the Fuente la Higuera altarpiece (1548. This study also verifies the popularity of the iconography of the seven sheddings of the Blood of Christ and processions of disciplinants.

    Se presenta un contrato inédito suscrito por la Cofradía de la Sangre de Cristo de la ciudad de Valencia con Vicente y Juan Macip en 1539. En él se especifica que sea pintado por Juan, más conocido con posterioridad como Juan de Juanes. Se refuerza la hipótesis que permite concretar a Juan Macip como el pintor más importante del taller de los Macip durante la década de los 30, al tiempo que se llena un vacío documental entre la entrega del retablo del gremio de plateros (1534-1539 y la contratación del retablo de Fuente la Higuera (1548. Se constata igualmente la popularidad de la iconografía de los siete derramamientos de la Sangre de Cristo y la procesión de los disciplinantes.

  2. Il mestiere di tradurre 5: Juan Carlos Reche

    Directory of Open Access Journals (Sweden)

    Juan Carlos Reche


    Full Text Available En la última década el traductor y poeta Juan Carlos Reche (Córdoba, 1976 ha dado a conocer algunos de los textos poéticos más relevantes y complejos de la literatura italiana de los últimos tiempos. Galardonado en 2013 con el Premio Nazionale per la Traduzione concedido por el Ministerio Italiano de Cultura, es además autor de poemarios propios como El dolor y la velocidad (Ed. Renacimiento, Sevilla, 1999 o Carrera del fruto (Ed. Pre-Textos, Valencia, 2006. Su doble condicion de poeta y traductor, el riesgo de enfrentarse a autores como Maurizio Cucchi, Giorgio Caproni o Giovanni Raboni, y la reciente aparición de la revista Años diez, que dirije junto al poeta Abraham Gragera, nos ha llevado a plantearle algunas preguntas sobre su labor en ambos campos. Entrevista de Juan Pérez Andrés.

  3. Obituary: Juan Antonio Paniagua (1920-2010, Medical Historian

    Directory of Open Access Journals (Sweden)

    Pedro Gil-Sotres


    Full Text Available The Spanish medical historian Juan Antonio Paniagua Arellano (Artajona, Navarre, 1920 passed away in Pamplona on 11th February. He read medicine at the University of Valladolid (1945 and received his PhD at the Complutense University of Madrid (1948. For thirty years he was Professor of History of Medicine and Pharmacy at the University of Navarra (Spain, where he carried out research into Medieval Latin Medicine and trained many students.

  4. San Juan Bay Estuary watershed urban forest inventory (United States)

    Thomas J. Brandeis; Francisco J. Escobedo; Christina L. Staudhammer; David J. Nowak; Wayne C. Zipperer


    We present information on the urban forests and land uses within the watershed of Puerto Rico’s 21 658-ha San Juan Bay Estuary based on urban forest inventories undertaken in 2001 and 2011. We found 2548 ha of mangrove and subtropical moist secondary forests covering 11.8 percent of the total watershed area in 2011. Red, black, and white mangroves (Rhizophora...

  5. Mercury accumulation in hydrothermal vent mollusks from the southern Tonga Arc, southwestern Pacific Ocean. (United States)

    Lee, Seyong; Kim, Se-Joo; Ju, Se-Jong; Pak, Sang-Joon; Son, Seung-Kyu; Yang, Jisook; Han, Seunghee


    We provide the mercury (Hg) and monomethylmercury (MMHg) levels of the plume water, sulfide ore, sediment, and mollusks located at the hydrothermal vent fields of the southern Tonga Arc, where active volcanism and intense seismic activity occur frequently. Our objectives were: (1) to address the potential release of Hg from hydrothermal fluids and (2) to examine the distribution of Hg and MMHg levels in hydrothermal mollusks (mussels and snails) harboring chemotrophic bacteria. While high concentrations of Hg in the sediment and Hg, As, and Sb in the sulfide ore indicates that their source is likely hydrothermal fluids, the MMHg concentration in the sediment was orders of magnitude lower than the Hg (mollusks were much higher (10-100 times) than in other hydrothermal vent environments, indicating that organisms located at the Tonga Arc are exposed to exceedingly high Hg levels. While Hg concentration was higher in the gills and digestive glands than in the mantles and residues of snails and mussels, the MMHg concentrations in the gills and digestive glands were orders of magnitude lower (0.004-0.04%) than Hg concentrations. In summary, our results suggest that the release of Hg from the hydrothermal vent fields of the Tonga Arc and subsequent bioaccumulation are substantial, but not for MMHg. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Probability hazard map for future vent opening at Etna volcano (Sicily, Italy). (United States)

    Scandura, D.; Montalto, P.; Brancato, A.; Cannavo, F.; Coltelli, M.; Mattia, M.; Patanè, D.; Proietti, C.


    The frequent flank eruptions occurrence at Mt. Etna lead to a high volcanic hazard that, linked to a population of nearly one million people dwell on its flanks, poses a high volcanic risk. In the framework of the project PON SIGMA (Integrated Cloud-Sensor System for Advanced Multirisk Management), we developed a near real-time computer-assisted analysis and probabilistic evaluations that provide the identification of the areas prone to the highest vent opening hazard. The use of a code such BET_EF (Bayesian Event Tree_Eruption Forecasting) provide us a long-term hazard map mainly based on the past behaviour of the Etna volcano. The near real-time additional seismic and ground deformation data allow the long-term hazard map switches into a short-term future vent opening one. The short-term hazard map was computed starting from the evaluation of deformation field over Etna surface. Analytical inversion of deformation and seismic data is performed to find the parameters of a magmatic source in an elastic, isotropic and homogeneous half-space and forward model is performed to computed the displacement field over Etna surface. We modelled the final intrusion of the Mount Etna May 2008 eruption that was accompanied by a violent seismic swarm and marked by ground deformation recorded at GPS stations. Results suggest a good accordance between the higher probability area and the real vent occurrence.

  7. La encrucijada en Pedro Páramo de Juan Rulfo / The Crossroads in Pedro Páramo by Juan Rulfo

    Directory of Open Access Journals (Sweden)

    Lilia Leticia García-Peña


    Full Text Available La obra de Juan Rulfo sintetiza la realidad del campo mexicano, captura el contorno de las identidades individuales y de la estructura de la interacción social del mundo que tanto le preocupó y del que es intérprete indiscutible, pero también supo convertir en materia narrativa aquellas atmósferas que rebasan el contexto mexicano y social. En este trabajo abordaré el tema de la encrucijada en el imaginario simbólico de Pedro Páramo (1955 como expresión de una reelaboración del mito de Hermes, analizaré cómo la novela de Juan Rulfo muestra estos ecos herméticos y qué sentido estético y sociocultural tiene esta resonancia mítica.

  8. Empirical Profiling of Cold Hydrogen Plumes Formed from Venting Of LH2 Storage Vessels: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Buttner, William J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Rivkin, Carl H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Schmidt, Kara [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hartmann, Kevin S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wright, Hannah [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Weidner, Eveline [Joint Research Centre, Petten, the Netherlands; Ciotti, Michael [H2 Fueling and CIP Markets Engineering


    Liquid hydrogen (LH2) storage is a viable approach to assuring sufficient hydrogen capacity at commercial fuelling stations. Presently, LH2 is produced at remote facilities and then transported to the end-use site by road vehicles (i.e., LH2 tanker trucks). Venting of hydrogen to depressurize the transport storage tank is a routine part of the LH2 delivery process. The behaviour of cold hydrogen plumes has not been well-characterized because empirical field data is essentially non-existent. The NFPA 2 Hydrogen Storage Safety Task Group, which consists of hydrogen producers, safety experts, and CFD modellers, has identified the lack of understanding of hydrogen dispersion during LH2 venting of storage vessel as a critical gap for establishing safety distances at LH2 facilities, especially commercial hydrogen fuelling stations. To address this need, the NREL sensor laboratory, in collaboration with the NFPA 2 Safety Task Group developed the Cold Hydrogen Plume Analyzer to empirically characterize the hydrogen plume formed during LH2 storage tank venting. A prototype Analyzer was developed and field-deployed at an actual LH2 venting operation with critical findings that included: - H2 being detected as much as 2 m lower than the release point, which is not predicted by existing models - A small and inconsistent correlation between oxygen depletion and the hydrogen concentration - A negligible to non-existent correlation between in-situ temperature and the hydrogen concentration The Analyzer is currently being upgraded for enhanced metrological capabilities including improved real-time spatial and temporal profiling of the plume and tracking of prevailing weather conditions. Additional deployments are planned to monitor plume behaviour under different wind, humidity, and temperatures. This data will be shared with the NFPA 2 Safety Task Group and ultimately will be used support theoretical models and code requirements prescribed in NFPA 2.

  9. A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents. (United States)

    Reysenbach, Anna-Louise; Liu, Yitai; Banta, Amy B; Beveridge, Terry J; Kirshtein, Julie D; Schouten, Stefan; Tivey, Margaret K; Von Damm, Karen L; Voytek, Mary A


    Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH cycling at deep-sea vents.

  10. Сombined Thermal Insulating Module of Mounted Vented Facades

    Directory of Open Access Journals (Sweden)

    Ryabukhina Svetlana


    Full Text Available In order to define an optimum type of mounted vented facades among the existing ones, comparative analysis of two façade modules has been conducted. The first module type is a widespread standard module of hinged vented facade and the second type is less applicable combined thermal insulating module. Those two technologies were compared thermal engineering and energy efficiency parameters. It was defined that the application of a thermal insulating module with combined insulation system improves thermal engineering parameters of the building as well as leads to a substantial savings. This article exposes innovative materials and structure of vented facades which can be applied in modern construction.

  11. Visualization of the air flow behind the automotive benchmark vent (United States)

    Pech, Ondrej; Jedelsky, Jan; Caletka, Petr; Jicha, Miroslav


    Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive vents and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark vent. The visualization was made for two different shapes of the inlet channel connected to the benchmark vent. The smoke visualization with the laser knife was used. The influence of the shape of the inlet channel to the airflow direction, its enlargement and position of air flow axis were investigated.

  12. Visualization of the air flow behind the automotive benchmark vent

    Directory of Open Access Journals (Sweden)

    Pech Ondrej


    Full Text Available Passenger comfort in cars depends on appropriate function of the cabin HVAC system. A great attention is therefore paid to the effective function of automotive vents and proper formation of the flow behind the ventilation outlet. The article deals with the visualization of air flow from the automotive benchmark vent. The visualization was made for two different shapes of the inlet channel connected to the benchmark vent. The smoke visualization with the laser knife was used. The influence of the shape of the inlet channel to the airflow direction, its enlargement and position of air flow axis were investigated.

  13. The Geologic Setting of Hydrothermal Vents at Mariana Arc Submarine Volcanoes: High-Resolution Bathymetry and ROV Observations (United States)

    Chadwick, W. W.; Embley, R. W.; de Ronde, C. E.; Stern, R. J.; Hein, J.; Merle, S.; Ristau, S.


    Remotely operated vehicle (ROV) dives were made at 7 submarine volcanoes between 14-23° N in the Mariana Arc in April 2004 with the ROPOS ROV. Six of these volcanoes were known to be hydrothermally active from CTD data collected during a previous expedition in March 2003: NW Rota-1, E Diamante, NW Eifuku, Daikoku, Kasuga-2, and Maug, a partly submerged caldera. The physical setting of hydrothermal venting varies widely from volcano to volcano. High-resolution bathymetric surveys of the summits of NW Rota-1 and NW Eifuku volcanoes were conducted with an Imagenex scanning sonar mounted on ROPOS. Near bottom observations during ROPOS dives were recorded with digital video and a digital still camera and the dives were navigated acoustically from the R/V Thompson using an ultra-short baseline system. The mapping and dive observations reveal the following: (1) The summits of some volcanoes have pervasive diffuse venting (NW Rota-1, Daikoku, NW Eifuku) suggesting that hydrothermal fluids are able to circulate freely within a permeable edifice. At other volcanoes, the hydrothermal venting is more localized (Kasuga-2, Maug, E Diamante), suggesting more restricted permeability pathways. (2) Some volcanoes have both focused venting at depth and diffuse venting near the summit (E Diamante, NW Eifuku). Where the hydrothermal vents are focused, fluid flow appears to be localized by massive lava outcrops that form steep cliffs and ridges, or by subsurface structures such as dikes. High-temperature (240° C) venting was only observed at E Diamante volcano, where the "Black Forest" vent field is located on the side of a constructional cone near the middle of E Diamante caldera at a depth of 350 m. On the side of an adjacent shallower cone, the venting style changed to diffuse discharge and it extended all the way up into the photic zone (167 m). At NW Eifuku, the pattern of both deep-focused and shallow-diffuse venting is repeated. "Champagne vent" is located at 1607 m, ~150 m

  14. La construcción de un mito : fortuna crítica de Juan de Juanes en los siglos XVI y XVII

    Directory of Open Access Journals (Sweden)

    Miguel Falomir Faus


    Full Text Available Este artículo pretende analizar los inicios de la fortuna crítica de Juan de Juanes en los siglos XVI y XVII. La «leyenda» de Juanes se asentó en su triple condición de gloria local, pintor ejemplar y artista piadoso, y quienes la forjaron, de Escolano a Vicente Vitoria pasando por Pacheco o Jusepe Martínez, no dudaron en potenciar, e incluso distorsionar, aquellas facetas de la personalidad de Juanes afines a sus intereses particulares.This article seeks to analyze the origins of the historiographical treatment of Juan de Juanes in the sixteenth and seventeenth centuries. The «myth» of Juanes was posited on three aspects: as exemplary and illustrious citizen, model forpainters, and pious artist. Those who forged this image of the artist, from Escolano to Vicente Vitoria and passing by Pacheco or Jusepe Martínez, did not doubt in emphasizing and even distorting those aspects of his personality and life that affirmed their individual interests.

  15. 40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods. (United States)


    ....1104 Process vents from continuous unit operations: applicability assessment procedures and methods. (a... from continuous unit operations. The owner or operator of a process vent is not required to determine... process vent from a batch unit operation manifolded with at least one process vent from a continuous unit...

  16. Ultrafine particles from a vented gas clothes dryer

    National Research Council Canada - National Science Library

    Wallace, Lance


    .... A major source was determined to be the gas clothes dryer. Although the dryer was vented to the outdoors it consistently produced an order of magnitude increase in the ultrafine concentrations compared to times with no indoor sources...

  17. 40 CFR 265.1032 - Standards: Process vents. (United States)


    ... owner or operator of a fa-cil-ity with process vents associated with distillation, fractionation, thin-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous wastes...

  18. Haakon Mosby Mud Volcano provides unusual example of venting (United States)

    Vogt, P. R.; Cherkashev, G.; Ginsburg, G.; Ivanov, G.; Milkov, A.; Crane, K.; Sundvor, A.; Pimenov, N.; Egorov, A.

    A seafloor mud volcano north of Norway is presenting researchers with an uncommon example of venting and is raising important questions. Seafloor aqueous vents, gas vents, mud volcanoes, and mud diapirs are found in a variety of geological settings. However, scientists did not expect to discover venting at the northern site, now known as the Haakon Mosby Mud Volcano (HMMV). It is considered especially unusual because of its Arctitc Location (72°N), its development largely within glacial marine sediments, and its lack of association either with salt tectonics or with plate subduction. Further, the volcano is posing questions for investigators about the relationship of methane generation and mud volcanism to thick, rapidly deposited sediments; sediment failure; and gas hydrates (GH).

  19. Turbofan Engine Core Compartment Vent Aerodynamic Configuration Development Methodology (United States)

    Hebert, Leonard J.


    This paper presents an overview of the design methodology used in the development of the aerodynamic configuration of the nacelle core compartment vent for a typical Boeing commercial airplane together with design challenges for future design efforts. Core compartment vents exhaust engine subsystem flows from the space contained between the engine case and the nacelle of an airplane propulsion system. These subsystem flows typically consist of precooler, oil cooler, turbine case cooling, compartment cooling and nacelle leakage air. The design of core compartment vents is challenging due to stringent design requirements, mass flow sensitivity of the system to small changes in vent exit pressure ratio, and the need to maximize overall exhaust system performance at cruise conditions.

  20. 40 CFR 65.143 - Closed vent systems. (United States)


    ...) CONSOLIDATED FEDERAL AIR RULE Closed Vent Systems, Control Devices, and Routing to a Fuel Gas System or a... of the equipment as frequently as practical during safe-to-inspect times. Inspection is not required...

  1. 40 CFR 63.983 - Closed vent systems. (United States)


    ... Emission Standards for Closed Vent Systems, Control Devices, Recovery Devices and Routing to a Fuel Gas... the equipment as frequently as practical during safe-to-inspect times. Inspection is not required more...

  2. Shallow seismicity at open-vent volcanoes (United States)

    Girona, T.; Caudron, C.; Huber, C.


    Understanding the origin of the shallow seismicity detected at active volcanoes is fundamental to interpret geophysical and geochemical signals in terms of sub-surface magmatic processes. One of the most intriguing seismic signals is shallow tremor, which is long-lasting (from minutes to months), is usually sourced at shallow levels ( 100's of meters), has dominant frequencies in the range 0.1-20 Hz, and is common to many open-vent and hydrothermal systems. Here, we present a viable mechanism to explain the origin of shallow tremor and its correlation with magma degassing. In particular, we show from basic principles (mass and momentum balance) that shallow tremor can emerge spontaneously as a result of three coupled processes: (1) the formation of gas pockets beneath rheological or geometrical barriers; (2) the intermittent supply of volatiles from depth, e.g., through a bubbly magma column; and (3) the permeable transfer of these gases through a porous lava dome, conduit, or volcanic edifice. Our model, which can be solved analytically at first order, reproduces and provides an explanation for the main features of shallow tremor, including frequency gliding, changes of seismic amplitude when volcanoes enter a period of unrest, and the different types of amplitude spectra observed (i.e., monochromatic, harmonic, and broadband). A crucial conclusion of our study is that different processes (e.g., magma ascent and sealing of gas pathways) cause distinguishable variations in the tremor properties, which could be used by monitoring agencies to improve volcanic forecasting.

  3. Biogeography of Persephonella in deep-sea hydrothermal vents of the Western Pacific.

    Directory of Open Access Journals (Sweden)

    Sayaka eMino


    Full Text Available Deep-sea hydrothermal vent fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea vents. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal ecosystem around the world, little is known about their population structure such as intraspecific genomic diversity, distribution pattern, and phenotypic diversity. We developed the multi-locus sequence analysis (MLSA scheme for their genomic characterization. Sequence variation was determined in five housekeeping genes and one functional gene of 36 P. hydrogeniphila strains originated from the Okinawa Trough and the South Mariana Trough. Although the strains share > 98.7% similarities in 16S rRNA gene sequences, MLSA revealed 35 different sequence types, indicating their extensive genomic diversity. A phylogenetic tree inferred from all concatenated gene sequences revealed the clustering of isolates according to the geographic origin. In addition, the phenotypic clustering pattern inferred from whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/MS analysis can be correlated to their MLSA clustering pattern. This study represents the first MLSA combined with phenotypic analysis indicative of allopatric speciation of deep-sea hydrothermal vent bacteria.

  4. Optimizing the night time with dome vents and SNR-QSO at CFHT (United States)

    Devost, Daniel; Mahoney, Billy; Moutou, Claire; CFHT QSO Team, CFHT software Group


    Night time is a precious and costly commodity and it is important to get everything we can out of every second of every night of observing. In 2012 the Canada-France-Hawaii Telescope started operating 12 new vent doors installed on the dome over the course of the previous two years. The project was highly successful and seeing measurements show that venting the dome greatly enhances image quality at the focal plane. In order to capitalize on the gains brought by the new vents, the observatory started exploring a new mode of observation called SNR-QSO. This mode consist of a new implementation inside our Queued Service Observation (QSO) system. Exposure times are adjusted for each frame depending on the weather conditions in order to reach a specific depth, Signal to Noise Ratio (SNR) at a certain magnitude. The goal of this new mode is to capitalize on the exquisite seeing provided by Maunakea, complemented by the minimized dome turbulence, to use the least amount of time to reach the depth required by the science programs. Specific implementations were successfully tested on two different instruments, our wide field camera MegaCam and our high resolution spectrograph ESPaDOnS. I will present the methods used for each instrument to achieve SNR observing and the gains produced by these new observing modes in order to reach the scientific goals of accepted programs in a shorter amount of time.

  5. 33 CFR 165.758 - Security Zone; San Juan, Puerto Rico. (United States)


    ... Security Zone; San Juan, Puerto Rico. (a) Location. Moving and fixed security zones are established 50... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Security Zone; San Juan, Puerto Rico. 165.758 Section 165.758 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND...

  6. 77 FR 52310 - Expansion of Foreign-Trade Zone 61, San Juan, Puerto Rico (United States)


    ... Foreign-Trade Zones Board Expansion of Foreign-Trade Zone 61, San Juan, Puerto Rico Pursuant to its...-Trade Zones Board (the Board) adopts the following Order: Whereas, the Puerto Rico Trade and Export... FTZ 61 to include a site in Aguadilla, Puerto Rico, adjacent to the San Juan U.S. Customs and Border...

  7. Las intrigas políticas de Juan Pacheco, del combate de Olmedo a la muerte de Juan II (1445-1454

    Directory of Open Access Journals (Sweden)

    Franco Silva, Alfonso


    Full Text Available In this essay, offered to the consideration of researchers, I try to analyse the political evolution of Juan Pacheco, royal favourite of Principe de Asturias, since thanks to the favour with Don Enrique he got the title and domain of Marquis of Villena in 1445 until Juan II died in 1454.

    En el trabajo que se ofrece a la consideración de los investigadores intento analizar la trayectoria política de Juan Pacheco, privado del Príncipe de Asturias, desde que merced a la privanza con don Enrique consiguiera el título y señorío de marqués de Villena en 1445 hasta la muerte de Juan II en 1454.

  8. Juan Rodríguez Freile (cronista colonial

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    Julio Enrique Cuervo Escobar


    Full Text Available Juan Rodríguez Freile -1566-1638-. Aspirante al sacerdocio, soldado en los albores de la Conquista y más tarde hombre pacífico, que cambió las armas por instrumentos de labranza y en la vejez por la pluma, escribiendo sobre la "Conquista y Descubrimiento del Nuevo Reino. de Granada . .. " (El título completo equivale al índice 1, crónica santafereña que ha pasado a la posteridad con el título familiar de '·'EI Carnero".

  9. Juan O’Gorman. Formas de no ser arquitecto


    Javier Jerez González


    La obra proyectada y construida por Juan O’Gorman a lo largo de su vida traza un recorrido largo y sincopado entre formas de entender la arquitectura totalmente antagónicas. Su primera etapa de radical racionalismo desarrolla, según procedimientos estrictamente técnicos, un lenguaje revolucionario basado en la austeridad y la precisión. A pesar de ello muchas de sus obras destacan por la plasticidad de sus composiciones volumétricas, la riqueza espacial o, incluso, por la creación de atmósfer...

  10. Juan Goytisolo y la “primavera árabe”

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    Marco Kunz


     Juan Goytisolo observed with enthusiasm, though with certain concern, the news about the revolutions that, since early 2011, overthrew several autocratical regimes (in Tunisia, Egypt and Libya, entailed reforms in other countries (Morocco and caused a yet unfinished civil war (Syria. He gave his opinions on this historical process in repor­tages, essays and, mainly, articles published in El País. Based on these texts, I intend to compare his current comments with ideas he expressed in the late 20th century and to analize argumentation figures that are characteristic of Goytisolo’s vision of the recent history of North Africa.

  11. Juan Valdez in the coffe market of France


    Rodriguez Maldonado, Edna Katherine


    El objetivo de este trabajo es presentar un marco organizacional en profundidad de las operaciones de Juan Valdez y sus posibilidades de incursionar en el mercado Francés. El Análisis se presenta en base a una investigación de mercados que tiene como referencia las tendencias de consumo, más exactamente hacía bebidas con alto contenido de cafeína, (Bebidas energizantes, deportivas, café etc.). Igualmente se analizan los socios estratégicos con más fuerza de realizar alianzas con la empresa c...

  12. Juan Antonio Ramírez : La arquitectura como imagen




    Juan Antonio Ramírez era historiador del arte, pero dedicó gran parte de su vida al estudio de la arquitectura. A lo largo de su obra podemos encontrar temas como la utopía arquitectónica, la arquitectura del renacimiento y el barroco, la arquitectura en el cine, o los autores de tratados. En este trabajo repasamos su trayectoria por el ámbito de la arquitectura, y buscamos las que fueron sus mayores aportaciones, como su metodología de análisis iconográfico, su noción de...

  13. Il mestiere di tradurre 1: entrevista a Juan Antonio Vivanco

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    Juan Antonio Vivanco Gefaell


    Full Text Available Hijo del poeta Luis Felipe Vivanco y de la escritora María Luisa Gefaell, Juan Antonio Vivanco Gefaell lleva más de tres décadas desarrollando una prestigiosa labor como traductor. Por sus manos han pasado autores italianos tan dispares como Roberto Saviano (La belleza y el infierno, Debolsillo, 2010, Paolo Maurensig (Canon inverso, Mondadori, 1997, Pier Paolo Pasolini (Escritos corsarios, Ed. Del Oriente, 2009 o Paolo Cottino (La ciudad imprevista, Bellaterra, 2005, por citar unos pocos.Traductor minucioso y preciso no sólo de textos narrativos, también se deben a él textos técnicos que abarcan media docena de especialidades humanísticas: desde  libros de antropología como el interesante Genes, pueblos y lengua de Luca Cavalli Sforza (Crítica, 1997, a textos de etnografía como La tierra del remordimiento de Ernesto de Martino (Bellaterra, 1999 en cuya traducción, nos comenta, disfrutó de forma especial, hasta llegar a densos manuales como la Historia de España de Joseph Pérez (Crítica, 1999 o Crisis e inflación entre la Antigüedad y la Edad Media de Georges Depeyrot (Crítica, 1996. Intentar abarcar el trabajo de Juan Antonio Vivanco implicaría, sin duda, citar las mejores editoriales de nuestro país y una amplia variedad temática hasta abarcar disciplinas tan diversas como la micología, el alpinismo, la historia del Arte y, especialmente, sus múltiples traducciones de estudios sobre Islam y Oriente Medio.Zibaldone. Estudios italianos le agradece que se haya prestado a inaugurar este espacio, Il mestiere di tradurre, contestando a unas preguntas sobre su trayectoria y su  profesión. Entrevista de Juan José Tejero y Juan Pérez Andrés. 

  14. Iglesia de San Juan Bautista, en Italia

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    Michelucci, Giovanni


    Full Text Available The building consists essentially of three parts: an entry processional gallery and the baptistery, to the left; to the ;right of the main entrance, the great nave; whilst between these there are two small cloisters. This chapel does not pretend to be an original design, or even a especially original structure. It must be interpreted rather as a shape that follows logically from the attempt to serve a spiritual need of man in a popular language. In this case, the architecture has been understood as something alive and changing, under the effects of light and shade. The plastic quality of this church induces an emotional uplift to those who look at it from the neighboring fields.El organismo arquitectónico está formado, esencialmente, por tres partes: una galería procesional de ingreso y el baptisterio, a la izquierda de la entrada principal, y la gran nave a la derecha; entre estos dos cuerpos existen dos pequeños claustros. Al proyectar esta iglesia no se ha tenido la pretensión de diseñar una forma nueva o de pensar en estructuras originales, sino que «la forma» resultante es una consecuencia lógica de la premisa fundamental: «servir a los hombres» en un lenguaje «popular». La arquitectura ha sido tratada, en este caso, como algo vivo y cambiante bajo los efectos de la luz, de la sombra, de las estaciones. La plástica de su forma orgánica imprime una sublime emoción al que la contempla desde la campiña circundante.

  15. 40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and... (United States)


    ... Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and Reporting Requirements 7 Table 7 to Subpart JJJ... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins Pt. 63, Subpt. JJJ, Table 7 Table 7 to Subpart JJJ of Part 63—Group 1 Batch Process Vents and Aggregate Batch Vent Streams...

  16. Paralelismos y divergencias entre Juan Tenorio de Tirso de Molina y Miguel Páramo, personaje de Juan Rulfo.

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    Herlinda Ramírez-Barradas.


    Full Text Available Resumen: En este breve artículo se presentan algunas características de Miguel Páramo que, primero, permiten incluirlo en la larga lista de personajes donjuanescos derivados de la obra de Tirso de Molina y que, además, hacen posible entender su función trágica.Summary: This article presents some of Miguel Páramo's characteristics that, first, allow including him in the long list of prominent Don Juan figures derived from Tirso de Molina's work and, in addition, make it possible to understand his tragic function.

  17. Juan O’Gorman. Formas de no ser arquitecto

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    Javier Jerez González


    Full Text Available La obra proyectada y construida por Juan O’Gorman a lo largo de su vida traza un recorrido largo y sincopado entre formas de entender la arquitectura totalmente antagónicas. Su primera etapa de radical racionalismo desarrolla, según procedimientos estrictamente técnicos, un lenguaje revolucionario basado en la austeridad y la precisión. A pesar de ello muchas de sus obras destacan por la plasticidad de sus composiciones volumétricas, la riqueza espacial o, incluso, por la creación de atmósferas oníricas. Los primeros años de frenética actividad dan paso a un periodo de voluntario alejamiento de la práctica profesional de la arquitectura: ni una sola obra, ni un solo proyecto durante cerca de 15 años. Tan solo su actividad docente le mantiene en contacto con el mundo de la arquitectura. Cuando Juan O’Gorman vuelve a ejercer como arquitecto, lo hace construyendo algunos de los iconos del movimiento de integración plástica de México: la biblioteca central de la UNAM y su casa en San Jerónimo. A pesar de las enormes diferencias, o más bien oposiciones, entre unos momentos y otros, puede identificarse una invariante clara como señal de identidad personal: una velada voluntad de no ser arquitecto


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    Arístides Osvaldo Fernández DE CIEZA


    Full Text Available With over 8,100 traffic fatalities in 1997 and an accident rate per 100 million vehicle kilometres travelled, approximately five times that of United States, Argentinean road authorities are now beginning to focus attention on traffic safety and driver education. One of the main problems in the search of causes for car accidents in Argentina is the lack of a reliable and updated data base. The results and conclusions presented in this paper are based on a thorough analysis of car accidents in the Province of San Juan, Argentina. A seven-year data base of car accidents has been compiled from police reports, including the results of traffic counts at intersections and other collision locations. In addition, topographic and filmed reports of such places and their surroundings bring about parameters such as stop lines, visibility triangles, road size, traffic light performance, etc., which allow to carrying out of a traffic flow analysis for proposing measures aiming to minimize accidents. For San Juan province, in general, the main causes are: high absolute car speeds, speed differences between vehicles, lack of good lighting, poor driving habits, lack of traffic control devices such as signs, signals, and an absence of road markings.

  19. Avifauna de la subcuenca del río San Juan, Guerrero, México Avifauna of the Río San Juan Basin, Guerrero, Mexico

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    R. Carlos Almazán-Núñez


    Full Text Available Se presenta un análisis de la riqueza avifaunística en diferentes tipos de vegetación en la subcuenca del río San Juan, perteneciente a la provincia biótica de la Cuenca del Balsas, Guerrero. El trabajo de campo se realizó de junio de 2001 a septiembre de 2002. La riqueza avifaunística en la zona fue de 164 especies considerando los registros previos. Se mencionan algunos registros de interés los cuales amplían su área de distribución geográfica dentro del estado. La riqueza de especies fue significativamente mayor en el bosque tropical caducifolio, presentando éste también el mayor número de especies exclusivas. El componente estacional de las especies indica que el 72% son residentes y el 28% restante son migratorias. Existe una mayor proporción de especies raras (37.5% y no comunes (38.2% que de abundantes (2.12% y comunes (3.5%. El endemismo en la zona es alto, ya que el 28% de las especies son endémicas de México. Del total de especies registradas, 6 se encuentran sujetas a protección especial.We present an analysis of the species richness and abundance of birds in several localities of the Río San Juan Basin, state of Guerrero, region belonging to the Balsas Basin biotic province. The field work was performed from June 2001 to September 2002. The species richness was 164 species, and for some species its geographic distribution within the state is expanded. The species richness was significantly higher in tropical deciduous forest, which also holds the greatest number of exclusive species. The seasonal component indicate that 72% of the species are residents and the 28% remaining are migratory. There are a major proportion of rare species (37.5% and uncommon (38.2% than abundant (2.12% and common (3.5%. The endemism in the region is high, because 28% of the species are endemic to Mexico. Six species are considered threatened.

  20. The relative effect of particles and turbulence on acoustic scattering from deep sea hydrothermal vent plumes revisited. (United States)

    Xu, Guangyu; Jackson, Darrell R; Bemis, Karen G


    The relative importance of suspended particles and turbulence as backscattering mechanisms within a hydrothermal plume located on the Endeavour Segment of the Juan de Fuca Ridge is determined by comparing acoustic backscatter measured by the Cabled Observatory Vent Imaging Sonar (COVIS) with model calculations based on in situ samples of particles suspended within the plume. Analysis of plume samples yields estimates of the mass concentration and size distribution of particles, which are used to quantify their contribution to acoustic backscatter. The result shows negligible effects of plume particles on acoustic backscatter within the initial 10-m rise of the plume. This suggests turbulence-induced temperature fluctuations are the dominant backscattering mechanism within lower levels of the plume. Furthermore, inversion of the observed acoustic backscatter for the standard deviation of temperature within the plume yields a reasonable match with the in situ temperature measurements made by a conductivity-temperature-depth instrument. This finding shows that turbulence-induced temperature fluctuations are the dominant backscattering mechanism and demonstrates the potential of using acoustic backscatter as a remote-sensing tool to measure the temperature variability within a hydrothermal plume.

  1. Réquiem para un cóndor ciego: Juan Lavalle según la visión estetizada de la dupla Sabato-Falú

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    Ariel Mamani


    Full Text Available Este artículo indaga las estrategias desplegadas por Ernesto Sabato para la difusión de su particular visión de la historia argentina, especialmente de la controvertida figura del general Juan Lavalle. El deseo de terciar en el campo intelectual y político lo llevó a ensayar diversas formas de participación en los combates por la reinterpretación del pasado. Romance de la Muerte de Juan Lavalle, obra poético-musical realizada en colaboración con el músico folclórico Eduardo Falú, es abordada con la intención de analizar la construcción de discursos acerca del pasado desde ámbitos historiográficos no tradicionalesThis article inquires about the strategies suggested by Ernesto Sabato for the diffusion of his point of view about argentinean history and in special, general Juan Lavalle’s life. The author, in his will of participating in the intellectual and political field, essayed to diverse forms of participation in its re-interpretation of past. His piece of work entitled Romance de la Muerte de Juan Lavalle has been written in collaboration with native music composer Eduardo Falú. My intention is to remark some of the quarrels which took place in the field of "memories" in the purpose of analyze the construction of the differents discourses about past from non traditional historical enclosures

  2. Vent Control as a Means of Enhancing Airbag Performance

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    Richard E. Zimmermann


    Full Text Available Typical automotive airbag systems have a fixed area vent for exiting gasses. The US Army Cockpit Airbag System (CABS is unvented to prolong the period during which the system can provide occupant protection during extended helicopter crash scenarios. In each application, system performance may be enhanced by providing a controlled vent area. This paper describes work conducted under a Phase I SBIR program sponsored by the NASA Langley Research Center. The work was focused on eventual inflatable restraint system applications in general aviation aircraft, and showed that appropriate vent control offers many enhancements. Two series of tests conducted during Phase I showed that inflatable restraint system size and weight can be reduced without degrading performance, injury potential in an out of position situation (OOPS deployment can be reduced, and peak bag pressures can be reduced (at any temperature during normal operation.

  3. Cabled-observatory Regional Circulation Moorings on the Endeavour segment of the Juan de Fuca Ridge (United States)

    Mihaly, S. F.


    In September of 2010, one of four moorings was deployed on the Endeavour node of the NEPTUNE Canada cabled-observatory network. The installation included the laying of a 7km cable from the node to the mooring site in the axial valley about 3km north of the Main Endeavour Vent Field over extraordinary bathymetry. This September, three more cables and secondary junction boxes will be deployed to support the three additional moorings that complete the regional circulation array. The cable-laying is facilitated by the Canadian Scientific Submersible Facility's ROV ROPOS and a remotely operated cable-laying system, whereas the actual deployment of the moorings is a two ship operation. The CCGS John P. Tully lowers the mooring anchor first, while the RV Thomas G. Thompson supports the ROV operations which navigate the mooring to underwater mateable cable end. Precise navigation is needed because there are few areas suitable for placement of the junction boxes. Scientifically, the moorings are designed and located to best constrain the hydrothermally driven circulation within the rift valley, the regional circulation can then be used as a proxy measurement for hydrothermal fluxes. Each mooring carries a current meter/ ctd pair at 4, 50, 125, and 200m, with an upward looking ADCP at 250m. The northern moorings are located between the Hi-Rise and Salty Dawg fields about 700m apart in the ~1km wide rift valley and the southern moorings are located south of the Mothra vent field. Here we present initial results from the four mooring array.

  4. Carbon dioxide vent for direct methanol fuel cells (United States)

    Prakash, Shruti; Mustain, William; Kohl, Paul A.

    Passive, stand-alone, direct methanol fuel cells require a pressure management system that releases CO 2 produced in the anode chamber. However, this must be done without allowing the methanol fuel to escape. In this paper, two siloxane membranes are investigated and shown to selectively vent CO 2 from the anode chamber. The addition of hydrophobic additives, 1,6-divinylperfluorohexane and 1,9-decadiene, improved the selectivity of the siloxane membranes. The best performing CO 2 vent was obtained with 50:50 wt% poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane.

  5. Hydrothermal vents and methane seeps: Rethinking the sphere of influence (United States)

    Levin, Lisa A.; Baco, Amy; Bowden, David; Colaco, Ana; Cordes, Erik E.; Cunha, Marina; Demopoulos, Amanda W.J.; Gobin, Judith; Grupe, Ben; Le, Jennifer; Metaxas, Anna; Netburn, Amanda; Rouse, Greg; Thurber, Andrew; Tunnicliffe, Verena; Van Dover, Cindy L.; Vanreusel, Ann; Watling, Les


    Although initially viewed as oases within a barren deep ocean, hydrothermal vent and methane seep communities are now recognized to interact with surrounding ecosystems on the sea floor and in the water column, and to affect global geochemical cycles. The importance of understanding these interactions is growing as the potential rises for disturbance from oil and gas extraction, seabed mining and bottom trawling. Here we synthesize current knowledge of the nature, extent and time and space scales of vent and seep interactions with background systems. We document an expanded footprint beyond the site of local venting or seepage with respect to elemental cycling and energy flux, habitat use, trophic interactions, and connectivity. Heat and energy are released, global biogeochemical and elemental cycles are modified, and particulates are transported widely in plumes. Hard and biotic substrates produced at vents and seeps are used by “benthic background” fauna for attachment substrata, shelter, and access to food via grazing or through position in the current, while particulates and fluid fluxes modify planktonic microbial communities. Chemosynthetic production provides nutrition to a host of benthic and planktonic heterotrophic background species through multiple horizontal and vertical transfer pathways assisted by flow, gamete release, animal movements, and succession, but these pathways remain poorly known. Shared species, genera and families indicate that ecological and evolutionary connectivity exists among vents, seeps, organic falls and background communities in the deep sea; the genetic linkages with inactive vents and seeps and background assemblages however, are practically unstudied. The waning of venting or seepage activity generates major transitions in space and time that create links to surrounding ecosystems, often with identifiable ecotones or successional stages. The nature of all these interactions is dependent on water depth, as well as

  6. Hydrothermal Vents and Methane Seeps: Rethinking the Sphere of Influence

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    Lisa Ann Levin


    Full Text Available Although initially viewed as oases within a barren deep ocean, hydrothermal vent and methane seep communities are now recognized to interact with surrounding ecosystems on the sea floor and in the water column, and to affect global geochemical cycles. The importance of understanding these interactions is growing as the potential rises for disturbance from oil and gas extraction, seabed mining and bottom trawling. Here we synthesize current knowledge of the nature, extent and time and space scales of vent and seep interactions with background systems. We document an expanded footprint beyond the site of local venting or seepage with respect to elemental cycling and energy flux, habitat use, trophic interactions, and connectivity. Heat and energy are released, global biogeochemical and elemental cycles are modified, and particulates are transported widely in plumes. Hard and biotic substrates produced at vents and seeps are used by benthic background fauna for attachment substrata, shelter, and access to food via grazing or through position in the current, while particulates and fluid fluxes modify planktonic microbial communities. Chemosynthetic production provides nutrition to a host of benthic and planktonic heterotrophic background species through multiple horizontal and vertical transfer pathways assisted by flow, gamete release, animal movements, and succession, but these pathways remain poorly known. Shared species, genera and families indicate that ecological and evolutionary connectivity exists among vents, seeps, organic falls and background communities in the deep sea; the genetic linkages with inactive vents and seeps and background assemblages however, are practically unstudied. The waning of venting or seepage activity generates major transitions in space and time that create links to surrounding ecosystems, often with identifiable ecotones or successional stages. The nature of all these interactions is dependent on water depth, as

  7. Pressure Venting Tests of Phenolic Impregnated Carbon Ablator (PICA) (United States)

    Blosser, Max L.; Knutson, Jeffrey R.


    A series of tests was devised to investigate the pressure venting behavior of one of the candidate ablators for the Orion capsule heat shield. Three different specimens of phenolic impregnated carbon ablator (PICA) were instrumented with internal pressure taps and subjected to rapid pressure changes from near vacuum to one atmosphere and simulated Orion ascent pressure histories. The specimens vented rapidly to ambient pressure and sustained no detectable damage during testing. Peak pressure differences through the thickness of a 3-inch-thick specimen were less than 1 psi during a simulated ascent pressure history.

  8. Active Venting Sites On The Gas-Hydrate-Bearing Hikurangi Margin, Off New Zealand: ROV Measurements And Observations (United States)

    Naudts, L.; Poort, J.; Boone, D.; Linke, P.; Greinert, J.; de Batist, M.; Henriet, J.


    During R.V. Sonne cruise SO191-3, part of the "New (Zealand Cold) Vents" expedition, RCMG deployed a CHEROKEE ROV "Genesis" on the Hikurangi Margin. This accretionary margin, on the east coast of New Zealand, is related to the subduction of the Pacific Plate under the Australian Plate. Several cold vent locations as well as an extensive BSR, indicating the presence of gas hydrates, have been found at this margin. The aims of the ROV-work were to precisely localize active methane vents, to conduct detailed visual observations of the vent structures and activity, and to perform measurements of physical properties and collect samples at and around the vent locations. The three investigated areas generally have a flat to moderate undulating sea floor with soft sediments alternating with carbonate platforms. The different sites were sometimes covered with dense fields of live clams or shell debris, often in association with tube worms, sponges and/or soft tissue corals. Active bubble- releasing seeps were observed at Faure's site and LM-3 site. Bubble-releasing activity was very variable in time, with periods of almost non-activity alternating with periods of violent outbursts. Bubble release occurred mainly from prominent depressions in soft-sediment sea floor. Bottom-water sampling revealed sometimes high concentrations of methane. Sediment-temperature measurements were largely comparable with the bottom- water temperature except for a "raindrop site" (with dense populations of polychaetes), where anomalous low sediment-temperature was measured. Further analysis of the ROV data together with the integration of other datasets will enable us to produce a model characterizing seep structure and environment.

  9. Norma y uso: las ideas educativas en Juan de Robles / Etymology and use: The educational ideas of Juan de Robles

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    Alejandro Gómez Camacho


    Full Text Available Resumen: Juan de Robles es uno de los más brillantes humanistas de nuestro Siglo de Oro, entre cuyas obras destaca El culto sevillano (1631. En este trabajo se analizan sus ideas educativas, centradas en la relación entre la ortografía y el aprendizaje de la escritura. Entre las ideas pedagógicas de Juan de Robles es muy relevante el rechazo vehemente de la ortografía fonética, entre otros motivos, porque no favorecía el aprendizaje de la lectura y de la escritura; en consecuencia, censura la creación de nuevas letras y de un nuevo orden para el alfabeto español. Los ortógrafos defensores de la ortografía fonética en el siglo XVII argumentaban que la nueva escritura permitiría a los niños aprender a leer y a escribir con más rapidez y facilidad; así como que la creación de nuevas letras y el establecimiento de un nuevo orden del alfabeto facilitarían su enseñanza. Frente a estas pretensiones, Juan de Robles defendió el alfabeto tradicional y la ortografía etimológica de origen latino porque eran los instrumentos adecuados para la alfabetización en nuestra lengua. También critica los colegios jesuitas y la Ratio Studiorum; las principales discrepancias entre la pedagogía de la Compañía de Jesús y las ideas educativas de Juan de Robles podrían concretarse en la primacía del español sobre el latín, y en el uso de cuentos y refranes populares para la educación en El culto sevillano. En conclusión, con la obra de Juan de Robles se incorpora definitivamente el argumento pedagógico que relaciona la ortografía y la gramática españolas con el aprendizaje de la lectura y de la escritura a la polémica sobre la ortografía española del Siglo de Oro, en defensa de la ortografía etimológica frente a las pretensiones de imponer una ortografía fonética en el primer tercio del siglo XVII. Abstract: Juan de Robles is considered one of the main humanists in the Spanish Golden Century. The most important of his works is

  10. Juan Antonio Rubio appointed as Director-General of CIEMAT

    CERN Multimedia


    Juan Antonio Rubio, Head of CERN's ETT unit (Education and Technology Transfer) has been appointed by the Spanish Ministry of Education and Science as the Director General of the Research Centre for Energy, Environment and Technology, CIEMAT. Dr Rubio's career began at the Spanish Nuclear Energy Commission where he held the posts of Investigator, Head of the High Energy Group and Head of Nuclear Physics and High Energy Division. Later, he was named Director of the Department of Basic Investigation and Scientific Director of the CIEMAT. In 1987 he joined CERN as Scientific Adviser to the Director General and Group Leader of the Scientific Assessment Group. Up to now, Dr Rubio has been the Head of the ETT unit, as well as Coordinator for Latin America and Commissioner for the 50th Anniversary of the Organization. He was born on 4 June 1944 in Madrid, and holds a Doctorate in Physical Sciences from the Universidad Complutense de Madrid.

  11. Central San Juan caldera cluster: Regional volcanic framework (United States)

    Lipman, Peter W.


    Eruption of at least 8800 km3 of dacitic-rhyolitic magma as 9 major ash-slow sheets (individually 150-5000 km3) was accompanied by recurrent caldera subsidence between 28.3 and about 26.5 Ma in the central San Juan Mountains, Colorado. Voluminous andesitic-decitic lavas and breccias were erupted from central volcanoes prior to the ash-flow eruptions, and similar lava eruptions continued within and adjacent to the calderas during the period of explosive volcanism, making the central San Juan caldera cluster an exceptional site for study of caldera-related volcanic processes. Exposed calderas vary in size from 10 to 75 km in maximum diameter, the largest calderas being associated with the most voluminous eruptions. After collapse of the giant La Garita caldera during eruption if the Fish Canyon Tuff at 17.6 Ma, seven additional explosive eruptions and calderas formed inside the La Garita depression within about 1 m.y. Because of the nested geometry, maximum loci of recurrently overlapping collapse events are inferred to have subsided as much as 10-17 km, far deeper than the roof of the composite subvolcanic batholith defined by gravity data, which represents solidified caldera-related magma bodies. Erosional dissection to depths of as much as 1.5 km, although insufficient to reach the subvolcanic batholith, has exposed diverse features of intracaldera ash-flow tuff and interleaved caldera-collapse landslide deposits that accumulated to multikilometer thickness within concurrently subsiding caldera structures. The calderas display a variety of postcollapse resurgent uplift structures, and caldera-forming events produced complex fault geometries that localized late mineralization, including the epithermal base- and precious-metal veins of the well-known Creede mining district. Most of the central San Juan calderas have been deeply eroded, and their identification is dependent on detailed geologic mapping. In contrast, the primary volcanic morphology of the

  12. El realismo "full hd" de Juan Francisco Ferré


    Florenchie, Amélie


    A partir de las teorías sobre el simulacro del filósofo francés Jean Baudrillard, así como del análisis del posmodernismo como resultado de la lógica cultural del capitalismo tardío de Fredric Jameson, y de los postulados más recientes de Eloy Fernández Porta sobre la evolución de la cultura hacia el paradigma estético del afterpop, nos proponemos estudiar en este artículo las características del “realismo de alta definición” definido por Juan Francisco Ferré a propósito de su penúltima novel...

  13. Multi-scale reservoir modeling as an integrated assessment tool for geo-sequestration in the San Juan Basin (United States)

    Young, G.; Haerer, D.; Bromhal, G.; Reeves, S.


    The Southwestern Regional Partnership on CO2 Sequestration conducted an Enhanced Coalbed Methane (ECBM)/Carbon Storage Pilot in the San Juan Basin as part of the ongoing DOE/NETL Carbon Capture and Storage Program. The primary goal of this pilot is to demonstrate the efficacy of using CO2 to enhance coalbed methane recovery particularly near reservoir abandonment pressure while also evaluating the suitability of coal seams for longer-term carbon storage. Basic geologic models of the coal seams were developed from well logs in the area. Production histories from several surrounding CBM wells were shown. To monitor the injection of up to 75,000 ton of CO2 beginning September 2007, seismic surveys and tiltmeter arrays were utilized. Larger-scale geo-hydrodynamic simulations were used to develop a regional model for the fluid dynamics of the northern San Juan Basin. Smaller-scale reservoir simulations, incorporating available laboratory and field data, were used to develop an improved understanding of reservoir dynamics within the specific 640-acre pilot area. Both modeling scales were critical to assessing the suitability of deploying commercial carbon storage programs throughout the basin. Reservoir characterization results on the optimization of total CO2 injection volume, injection rate over time, and how CO2 is expected to disperse after injection are presented. This is an abstract of a paper presented at the 2007 AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).

  14. Faulting and hydration of the Juan de Fuca plate system (United States)

    Nedimović, Mladen R.; Bohnenstiehl, DelWayne R.; Carbotte, Suzanne M.; Pablo Canales, J.; Dziak, Robert P.


    Multichannel seismic observations provide the first direct images of crustal scale normal faults within the Juan de Fuca plate system and indicate that brittle deformation extends up to ~ 200 km seaward of the Cascadia trench. Within the sedimentary layering steeply dipping faults are identified by stratigraphic offsets, with maximum throws of 110 ± 10 m found near the trench. Fault throws diminish both upsection and seaward from the trench. Long-term throw rates are estimated to be 13 ± 2 mm/kyr. Faulted offsets within the sedimentary layering are typically linked to larger offset scarps in the basement topography, suggesting reactivation of the normal fault systems formed at the spreading center. Imaged reflections within the gabbroic igneous crust indicate swallowing fault dips at depth. These reflections require local alteration to produce an impedance contrast, indicating that the imaged fault structures provide pathways for fluid transport and hydration. As the depth extent of imaged faulting within this young and sediment insulated oceanic plate is primarily limited to approximately Moho depths, fault-controlled hydration appears to be largely restricted to crustal levels. If dehydration embrittlement is an important mechanism for triggering intermediate-depth earthquakes within the subducting slab, then the limited occurrence rate and magnitude of intraslab seismicity at the Cascadia margin may in part be explained by the limited amount of water imbedded into the uppermost oceanic mantle prior to subduction. The distribution of submarine earthquakes within the Juan de Fuca plate system indicates that propagator wake areas are likely to be more faulted and therefore more hydrated than other parts of this plate system. However, being largely restricted to crustal levels, this localized increase in hydration generally does not appear to have a measurable effect on the intraslab seismicity along most of the subducted propagator wakes at the Cascadia margin.

  15. 40 CFR 63.693 - Standards: Closed-vent systems and control devices. (United States)


    ...) Whenever gases or vapors containing HAP are vented through a closed-vent system connected to a control... of such devices include, but are not limited to, a car-seal or a lock-and-key configuration valve. (d...

  16. Previously unsuspected dietary habits of hydrothermal vent fauna: the bactivorous shrimp Rimicaris hybisae can be carnivorous or even cannibalistic (United States)

    Versteegh, Emma; Van Dover, Cindy; Coleman, Max


    Most hydrothermal vents support productive communities, with chemosynthetic bacteria at the base of the food web. They form a potentially important link in global geochemical cycles. However, few data yet exist on their significance in ocean biogeochemistry and related ecological processes. We present results on the structure of part of the food web around hydrothermal vents of the Mid-Cayman Rise (MCR), revealing previously unknown life-history traits of the alvinocarid shrimp species Rimicaris hybisae. We also demonstrate that stable carbon isotope ratios (δ13C values) are an excellent tracer of trophic positions in these ecosystems, in spite of recent findings arguing otherwise. Two hydrothermal vent fields have been described at the ultra-slow spreading ridge of the MCR. These include the world's deepest hydrothermal vents (Piccard field ~4985 m), which support a food web, which includes bactivorous shrimp and carnivorous anemones. The nearby Von Damm vent field (~2300 m) supports a more complex food web, with more primary producers, and probably some influx of photosynthetically produced carbon. Rimicaris hybisae is abundant at both known MCR vent fields and shows a high degree of spatial variability in population structure and reproductive features. In previous work it has been considered bactivorous. Large variations in tissue δ13C values remained largely unexplained, and it has been argued that δ13C values are not a good food web tracer in hydrothermal vent ecosystems. We observed that shrimp tended to be either in dense aggregations on active chimneys or more sparsely distributed, peripheral shrimp in ambient or near-ambient temperatures. With the hypothesis that varying δ13C values show real differences in food sources between individuals and that shrimp in different locales might have different diets, we collected shrimp from both environments at the Von Damm site during E/V Nautilus (NA034, August 2013) and examined their gut contents. Stomach

  17. Genetic diversity in Oroxylum indicum (L.) Vent. (Bignoniaceae), a ...

    African Journals Online (AJOL)



    Feb 5, 2008 ... Random amplified polymorphic DNA (RAPD) markers were used to assess genetic diversity in. Oroxylum indicum (L.) Vent (Bignoniaceae) a vulnerable medicinal plant collected from eight locations in Andhra Pradesh, India. High level of genetic similarity was observed in the collected accessions.

  18. Population genetic structure of Rufous-Vented Prinia ( Prinia burnesii )

    African Journals Online (AJOL)

    The objective of the study is to ascertain genetic variation within Rufous-vented Prinia, Prinia burnesii an endemic species, by DNA fingerprinting applying random amplified polymorphic DNA (RAPD) technique. Genetic material was obtained from three distant sites along western bank of River Indus. These sites include ...

  19. Assessment of retrofit automatic vent dampers for residential heating systems

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, D.L.; Wilson, R.P. Jr.; Ashley, L.E.; Butterfield, J.F.


    Automatic vent dampers are devices installed in the exhaust vent of a central heating system which prohibit the chimney flow of warm air from the dwelling space and from within the furnace when the heating system is not operating. An investigation of the effect of thermally actuated or electrically actuated dampers on home energy conservation, their cost, and safety is described. Eleven heating system types in 2 geographic regions were used in this study. It was determined that good quality, safe electrically actuated dampers are available in the U.S. and that thermally actuated units will be available soon; an average savings of approximately 8% in home heating cost could be achieved by using automatic dampers with suitable furnace systems in regions with a heating season of more than 4000 degree-days; the cost of the automatic dampers is from $65 to $140 with a payback period of 3 to 4 1/2 y; and, with the average heating system, vent damper retrofit alone is not as an attractive energy conservation option as combined vent damper, intermittent ignition device retrofit, and reduced gas orifice. (LCL)

  20. Genetic diversity in Oroxylum indicum (L.) Vent. (Bignoniaceae), a ...

    African Journals Online (AJOL)

    Genetic diversity in Oroxylum indicum (L.) Vent. (Bignoniaceae), a vulnerable medicinal plant by random amplified polymorphic DNA marker. ... results show that the genetic diversity of this species is low, possibly depicting a difficulty in adapting to environmental variations. This distributive pattern of genetic variation of O.

  1. Fault control on patterns of Quaternary monogenetic vents in the ...

    African Journals Online (AJOL)

    ... cone populations reveal that monogenetic vent alignments and the long axes of elongate cones are parallel to and spatially linked with mapped normal faults. This is consistent with the overall sub- latitudinal extension direction in the Quaternary deduced from fault slip analysis and earthquake focal mechanism solutions.

  2. Ephemerality of discrete methane vents in lake sediments (United States)

    Scandella, Benjamin P.; Pillsbury, Liam; Weber, Thomas; Ruppel, Carolyn D.; Hemond, Harold F.; Juanes, Ruben


    Methane is a potent greenhouse gas whose emission from sediments in inland waters and shallow oceans may both contribute to global warming and be exacerbated by it. The fraction of methane emitted by sediments that bypasses dissolution in the water column and reaches the atmosphere as bubbles depends on the mode and spatiotemporal characteristics of venting from the sediments. Earlier studies have concluded that hot spots—persistent, high-flux vents—dominate the regional ebullitive flux from submerged sediments. Here the spatial structure, persistence, and variability in the intensity of methane venting are analyzed using a high-resolution multibeam sonar record acquired at the bottom of a lake during multiple deployments over a 9 month period. We confirm that ebullition is strongly episodic, with distinct regimes of high flux and low flux largely controlled by changes in hydrostatic pressure. Our analysis shows that the spatial pattern of ebullition becomes homogeneous at the sonar's resolution over time scales of hours (for high-flux periods) or days (for low-flux periods), demonstrating that vents are ephemeral rather than persistent, and suggesting that long-term, lake-wide ebullition dynamics may be modeled without resolving the fine-scale spatial structure of venting.

  3. Juan Gelman: Fábulas y revolución poética = Juan Gelman: Fables and poetic revolution

    Directory of Open Access Journals (Sweden)

    Ching-Yu Lin


    Full Text Available Resumen: El presente estudio se centra en Fábulas de Juan Gelman para analizar la vinculación entre el género fabulístico y la revolución poética subyacente en su obra. Se trata de un nuevo modo de contar la realidad y las circunstancias sociales. Los poemas mezclan la historia oficial y la ficción para proponer miradas alternativas y subvertir convencionalismos y formalismos. Además, se crean personajes anónimos a fin de relatar visiones fabulosas en relación con la identidad colectiva. Esta técnica causa un efecto del extrañamiento y distanciamiento que desemboca en una reflexión profunda sobre la vida real. Finalmente, se reescriben leyendas exóticas, inventando episodios, con la finalidad de llamar la atención sobre ciertos fenómenos de la sociedad actual e inspirar solidaridad.Abstract: This study focuses on Fábulas of Juan Gelman. The aim is to analyze the relationship between fable genre and poetic revolution in this work, in which Gelman provides a new way of describing reality and social circumstances. His poems combine official history with fiction to propose alternative views and subvert conventionalism and formalism. In addition, this poet creates anonymous characters to relate fabulous visions regarding the collective identity. This technique results in estrangement and distancing, which lead to profound reflection on real life. Finally, exotic legends are rewritten by means of invented episodes to draw attention to certain phenomena of modern society and inspire solidarity.

  4. 40 CFR 63.487 - Batch front-end process vents-reference control technology. (United States)


    ... § 63.487 Batch front-end process vents—reference control technology. (a) Batch front-end process vents... process vent, reduce organic HAP emissions for the batch cycle by 90 weight percent using a control device... control device as it relates to continuous front-end process vents shall be used. Furthermore, the...

  5. 40 CFR 63.486 - Batch front-end process vent provisions. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vent provisions... Batch front-end process vent provisions. (a) Batch front-end process vents. Except as specified in paragraph (b) of this section, owners and operators of new and existing affected sources with batch front...

  6. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems. (United States)


    ... 10 Energy 1 2010-01-01 2010-01-01 false Acceptance criteria for reactor coolant system venting... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high point vents for the reactor coolant system, for the reactor vessel head, and for other systems required...

  7. 40 CFR 63.1407 - Non-reactor batch process vent provisions. (United States)


    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Non-reactor batch process vent... § 63.1407 Non-reactor batch process vent provisions. (a) Emission standards. (1) Owners or operators of non-reactor batch process vents located at new or existing affected sources with 0.25 tons per year (0...

  8. A New Deep-Sea Hydrothermal Vent Species of Ostracoda (Crustacea) from the Western Pacific: Implications for Adaptation, Endemism, and Dispersal of Ostracodes in Chemosynthetic Systems. (United States)

    Tanaka, Hayato; Yasuhara, Moriaki


    Deep-sea hydrothermal vent fields are among the most extreme habitats on Earth. Major research interests in these ecosystems have focused on the anomalous macrofauna, which are nourished by chemoautotrophic bacterial endosymbionts. In contrast, the meiofauna is largely overlooked in this chemosynthetic environment. The present study describes a new species, Thomontocypris shimanagai sp. nov. (Crustacea: Ostracoda), which was collected from the surface of colonies of neoverrucid barnacles and paralvinellid worms on the chimneys at the Myojin-sho submarine caldera. This is the first discovery of an ostracode from deep-sea hydrothermal vent environments in the western Pacific region. In addition to the species description, we discuss three aspects: 1) adaptation, 2) endemism, and 3) dispersal strategy of the hydrothermal vent ostracodes. Regarding these aspects, we conclude the following: 1) the new species may feed on sloughed-off tissues, mucus secretions, or fecal pellets of sessile organisms, rather than depend on chemoautotrophic bacteria as symbionts for energy; 2) as has been pointed out by other studies, Thomontocypris does not likely represent a vent-specific genus; however, this new species is considered to be endemic at the species level, as it has not been found outside of the type locality; and 3) this new species may have migrated from adjacent deep-sea chemosynthesis-based habitats, such as hydrothermal vents, with wood falls potentially having acted as stepping stones.

  9. Iconografía de los Santos Juanes en el arte valenciano


    Vilaplana Zurita, David Manuel


    El artículo aborda la importancia y la repercusión de la iconografía de San Juan Bautista y San Juan Evangelista en Valencia, tras analizar los orígenes y evolución de esta iconografía, de la que se esboza un ensayo de catalogación en el ámbito concreto del arte valenciano.

  10. Juan L. Ortíz: Primeros diálogos

    Directory of Open Access Journals (Sweden)

    Roxana Haydée Páez


    Full Text Available Emergencia, contextualización y diferencia de la poética de Juan L. Ortiz. El intertexto de lo que Julia Kristeva considera la primera vanguardia o vanguardia de fin de siglo, de los poetas argentinos posmodernistas, de Juan Ramón Jiménez. Vinculaciones del impresionismo de Ortiz, a través del simbolismo, el modernismo y el sencillismo

  11. Stenocercus doellojuradoi (Iguanidae, Tropidurinae: una nueva especie para la provincia de San Juan, Argentina

    Directory of Open Access Journals (Sweden)

    Laspiur, Alejandro


    Full Text Available República Argentina, Provincia de San Juan, Depto. Valle Fértil, 3 km al norte de la localidad de Las Tumanas sobre la Ruta Provincial 510 (30°52’ S, 67°20’ W. COLECTOR: Alejandro Laspiur. FECHA: 25 /02/ 2006. MATERIAL DE REFERENCIA: Instituto y Museo de Ciencias Naturales, Universidad Nacional de San Juan: IMCNUNSJ 3000. Un ejemplar macho (LHC: 54 mm..

  12. Comentario al Libro Juan de Dios Carrasquilla, Hombre de Ciencia”

    Directory of Open Access Journals (Sweden)

    José Félix Patiño Restrepo


    Full Text Available

    La historia de la medicina es, en gran parte, la historia de la ciencia y la historia de la ciencia es la historia de la humanidad. A su vez, las biografías de los médicos conforman como lo dice Sherwin Nuland, la biografía de la medicina. Adolfo De Francisco Zea presenta la tercera biografía de médicos ilustres de Colombia. Primero en 1997 apareció su obra El Doctor José Félix Merizalde y la Medicina a comienzos del siglo XIX en Santa Fe de Bogotá. Luego, en 1999 como la anterior con el patrocinio de la Academia Colombiana de Historia, el estudio biográfico sobre Luis Zea Uribe. Su Vida y su Época, su eminente abuelo materno que tanta influencia tuvo en la escogencia de la medicina como vocación por Adolfo De Francisco.

    La presente obra Juan de Dios Carrasquilla, Hombre de Ciencia, es otra formidable biografía de un personaje que vivió a finales del siglo XIX, la gran revolución científica desatada con el descubrimiento del origen microbiano de las enfermedades, y como lo escribe el autor, “A Juan de Dios Carrasquilla le correspondió hacer el tránsito gradual que va desde las visiones clínicas de un pasado cercano, hasta las concepciones científicas de un presente más rico en soluciones para los problemas médicos, y más adecuado para el desarrollo de las investigaciones que habría de realizar en el difícil y poco explorado campo de la más temible de las enfermedades de todos los tiempos: la lepra”.

    Adolfo De Francisco presenta, en elegante prosa y con base en formidable documentación, la personalidad de Juan de Dios Carrasquilla, cuya vida fue fundamentalmente una continuada aventura intelectual. Como los médicos más destacados de su época, Carrasquilla viajó a Europa, motivado también por su interés en la mineralogía y la geología. En efecto, este médico, nieto de médico, desde temprana edad cultivó una afición especial por las ciencias naturales.

    Es así como De Francisco destaca

  13. Environmental controls on chemoautotrophic primary producers at deep-sea vents (United States)

    Le Bris, Nadine; Mullineaux, Lauren; Sievert, Stefan


    High biomasses and fast growth rates of dominant chemosynthetic species characterize hydrothermal ecosystems, raising the issue of their contribution to energy transfer and carbon cycling in the deep-sea. Addressing this issue, however, needs to account for the temporal instability of hydrothermal systems, both, in terms of biological colonization and habitat conditions. Volcanic eruptions on mid-ocean ridges offer the opportunity to investigate the environmental conditions favoring the successive modes of chemoautotrophic primary production (i.e. free living microbes and symbiotic invertebrates). In that perspective, habitat-scale approaches distinguish from vent field-scale approaches based on fluid composition and provide relevant information on environmental constraints exerted at different stages of colonization focusing on parameters linked with physiological limits and available energy. Investigation of habitat physicochemical properties along a typical successional sequence of recolonization at 9°50'N EPR diffuse-flow vents, between 2006 and 2014, was performed in order to examine potential changes in environmental features associated with chemoautotrophic primary producers, from early microbial colonizers to symbiotic invertebrates. Combined in situ measurements of temperature, pH and hydrogen sulfide were used and their variability documented over a series of assemblages characterizing recolonization stages. The distributions of mature assemblages of dominant invertebrate species associate with substantial differences in habitat conditions, pointing to a strong influence of habitat properties on potential productivity. Among the differences observed, however, the amplitude and rate of environmental fluctuation appear more important than average conditions in the succession, highlighting the role of spatial heterogeneity and temporal dynamics as a control on primary producers. Invertebrate species acting as engineer species are expected to play a primary

  14. A new record for American Bullfrog (Lithobates catesbeianus in San Juan, Argentina Nuevo registro de rana toro americana (Lithobates catesbeianus en San Juan, Argentina

    Directory of Open Access Journals (Sweden)

    Eduardo Sanabria


    Full Text Available We report a new record of Lithobates catesbeianus (American bullfrog from Argentina. L. catesbeianus was first introduced to San Juan Province 11 years ago in Calingasta Department, where the habitat is pre-cordilleran. The new record is for Zonda Department, San Juan Province, in the Monte desert region. Here, L. catesbeianus uses artificial ponds for reproduction and tadpole development. These ponds receive water from an irrigation system that connects the whole agriculture land in the region. The tadpoles use the irrigation canals to move among ponds. We suggest that legislation should be established to prevent future invasions and to achieve sustainable management of the wild American bullfrog populations in San Juan. Prevention of future invasion and management of established populations of this species requires the cooperation of numerous stake holders.Se presenta un nuevo registro de Lithobates catesbeianus (rana toro americana en Argentina. L. catesbeianus fue introducida por primera vez a la provincia de San Juan hace 11 años en el Departamento Calingasta, donde el hábitat es pre-cordillerano. El nuevo registro es para el Departamento Zonda en la provincia de San Juan, en el desierto del Monte. En este sitio, L. catesbeianus usa estanques artificiales para la reproducción y desarrollo del renacuajo. Los estanques reciben agua de un sistema de riego que conecta todas las tierras de la agricultura en la región. Los renacuajos utilizan los canales de riego para moverse entre los estanques. Sugerimos que se establezcan leyes para prevenir invasiones futuras y para lograr un manejo integrado de las poblaciones silvestres de rana toro que se encuentran en San Juan. La prevención de futuras invasiones y el manejo de las poblaciones establecidas de esta especie requieren la cooperación de numerosas entidades tanto gubernamentales como privadas.

  15. Explosive volcanism on Mercury: Analysis of vent and deposit morphology and modes of eruption (United States)

    Jozwiak, Lauren M.; Head, James W.; Wilson, Lionel


    The MESSENGER mission revealed, for the first time, conclusive evidence of explosive volcanism on Mercury. Several previous works have cataloged the appearance and location of explosive volcanism on the planet using a variety of identifying characteristics, including vent presence and deposit color as seen in multispectral image mosaics. We present here a comprehensive catalog of vents of likely volcanic origin; our classification scheme emphasizes vent morphology. We have analyzed the morphologies of all vents in our catalog, and recognize three main morphologies: "simple vent", "pit vent", and "vent-with-mound". The majority of vents we identify are located within impact craters. The spatial distribution of vents does not correlate with the locations of volcanic smooth plains deposits, in contrast to the Moon, nor do vents correlate with the locations of large impact basins (except for the Caloris and Tolstoj basins). Using the degradation state of the vent host crater as a proxy for maximum age, we suggest that vent formation has been active through the Mansurian and into the Kuiperian periods, although the majority of vents were likely formed much earlier in mercurian history. The morphologies and locations of vents are used to investigate a set of plausible formation geometries. We find that the most likely and most prevalent formation geometry is that of a dike, stalled at depth, which then explosively vents to the surface. We compare the vent and deposit size of mercurian pyroclastic deposits with localized and regional lunar pyroclastic deposits, and find a range of possible eruption energies and corresponding variations in eruption style. Localized lunar pyroclastic deposits and the majority of mercurian pyroclastic deposits show evidence for eruption that is consistent with the magmatic foam at the top of a dike reaching a critical gas volume fraction. A subset of mercurian vents, including the prominent Copland-Rachmaninoff vent to the northeast of the

  16. Zero Gravity Cryogenic Vent System Concepts for Upper Stages (United States)

    Flachbart, Robin H.; Holt, James B.; Hastings, Leon J.


    The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space, and would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray-bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray-bar system consists of a recirculation pump, a parallel flow concentric tube heat exchanger, and a spray-bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses.

  17. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Stratton, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wray, Craig P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    In many residential building retrofit programs, air tightening to increase energy efficiency is constrained by concerns about related impacts on the safety of naturally vented combustion appliances. Tighter housing units more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spillage. Several test methods purportedly assess the potential for depressurization-induced backdrafting and spillage, but these tests are not robustly reliable and repeatable predictors of venting performance, in part because they do not fully capture weather effects on venting performance. The purpose of this literature review is to investigate combustion safety diagnostics in existing codes, standards, and guidelines related to combustion appliances. This review summarizes existing combustion safety test methods, evaluations of these test methods, and also discusses research related to wind effects and the simulation of vent system performance. Current codes and standards related to combustion appliance installation provide little information on assessing backdrafting or spillage potential. A substantial amount of research has been conducted to assess combustion appliance backdrafting and spillage test methods, but primarily focuses on comparing short-term (stress) induced tests and monitoring results. Monitoring, typically performed over one week, indicated that combinations of environmental and house operation characteristics most conducive to combustion spillage were rare. Research, to an extent, has assessed existing combustion safety diagnostics for house depressurization, but the objectives of the diagnostics, both stress and monitoring, are not clearly defined. More research is also needed to quantify the frequency of test “failure” occurrence throughout the building stock and assess the statistical effects of weather (especially wind) on house depressurization and in turn on combustion appliance venting

  18. Demistifikasi Tokoh Don Juan dalam La Nuit De Valognes Karya Eric-Emmanuel Schmitt

    Directory of Open Access Journals (Sweden)

    Talha Bachmid


    Full Text Available Don Juan is a myth about a seducer, a man with many love adventures, a women’s heat conqueror, and many other predicates. Don Juan as a myth is well-known world wide over, appearing in about 50 writings such as novels, plays, operas. But a French writer Eric-Emannuel Schmitt proposes a new figure of Don Juan in his play La Nuit de Valognes (Night in Valognes: the seducer is judged by five victims and convicted to marry one of his victims in order to stop his adventures. Surprisingly, Don Juan accepts this verdict without conditions. This sudden change becomes the theme of the play: the demythification of Don Juan. A flash back scene shows the beginning of this change and the interpretations that might arise from here. One possible interpretation is proposed and discussed in this paper: Don Juan found the way to a purer love, which is the union with God, and decides to begin his journey. This play can thus be categorised as a sufi text.

  19. From surfaces to magnetic properties: special section dedicated to Juan Rojo (United States)

    Mascaraque, A.; Rodríguez de la Fuente, O.; González-Barrio, Miguel A.


    Surface physics and magnetism, in particular the connection between surface defects, reduced dimensionality or size, crystal structure, electronic density of states and the mechanical and magnetic properties of solids, were always at the core of Juan Rojo's scientific interest and output. Both fields seem to meet at the nanoscale, a privileged playing field which is ideal for testing theoretical concepts, exploring new physics or probing a wealth of new, stunning and unheard-of applications. Upon reducing size or dimensionality, either in bulk systems or in thin films, surfaces and surface effects are telling. Thus, for instance, an ultra-thin coating can make nanoparticles of non-magnetic materials exhibit magnetic behaviour; or atomic steps can modify the local mechanical properties of a metallic single crystal. In this special section there are eight invited papers by disciples and close collaborators of Juan Rojo, that cover an ample spectrum of the above mentioned topics. The first paper, by Palacio et al, investigates the temperature and oxygen partial pressure conditions for FeO mono- and bi-layer growth on Ru(0001). The following paper, by Cortés-Gil et al, reports on the dramatic change in the electric resistivity of the manganite perovskite (La0.5Ca0.5)z MnO3 as a function of Ca content, an effect related to the removal of a charge-ordered state and a magnetic transition. Baeza et al study biomaterials for bone cancer treatment and skeletal reinforcing, as well as targeted magnetic nanoparticles used for intracell hyperthermia in cancer therapies. In the following paper, Marcano et al, assisted by a multi-technique approach, revisit the extraordinarily rich magnetic phase diagram of the Kondo system CeNi1- x Cux down to 100 mK temperatures. The magnetic field dependence of the martensitic transition temperature of the meta-magnetic shape memory alloy Ni50Mn34.5In15.5 in a crystalline and amorphous phase, in fields up to 13 T, is the subject of the paper

  20. Hydrogen may be an energy source for endosymbiotic bacteria of the vent mussel Bathymodiolus puteoserpentis (United States)

    Zielinski, F.; Pape, T.; Wenzhöfer, F.; Seifert, R.; Dubilier, N.


    The ultramafic hosted Logatchev hydrothermal vent field at the slow spreading Mid-Atlantic Ridge (MAR) exhibits unusually high hydrogen concentrations due to serpentinization of ultramafic rocks. Endmember H2-concentrations here have been calculated to be as high as 12 mM which is significantly higher than at most other vent sites along the MAR. Hydrogen is a potential energy source for bacteria providing an energy yield of roughly 240 kJ/mol if oxidized with oxygen. Hence, the energy yield is even higher than for conventional aerobic respiration which liberates 220 kJ/mol. The ability to use H2 as an energy source has been shown for a variety of free-living bacteria. However, to date no other energy sources besides methane and sulfide have been identified for vent (or seep) symbionts. Here we show that H2 is consumed by endosymbiotic bacteria of the Logatchev vent mussel Bathymodiolus puteoserpentis. B. puteoserpentis is known to live in dual symbiosis with methane- and sulfide-oxidizing bacteria that occur intracellularly in specialized gill cells called bacteriocytes. The methanotrophic symbionts use methane as both an energy and carbon source whereas the thiotrophic symbionts use H2S as an energy and dissolved CO2 as a carbon source. Hydrothermal fluids carrying methane and sulfide provide the energy for the bacteria and the bacteria in turn provide the mussel with carbon compounds. The mussel on the other hand supplies its symbionts with a constant fluid flow and, by hosting them offers an ideal ecological niche. Freshly dissected gill pieces of B. puteoserpentis incubated in chilled sea water containing hydrogen gas readily consumed H2. The consumption of H2 over time was significantly higher in gill tissues than in symbiont-free mussel tissue indicating that the symbiotic bacteria are responsible for the observed activity. H2-consumption rates were similar in mussels from two different sampling sites, Irina II: 37 nmol h-1 (ml gill)-1 and Quest: 31 nmol h-1

  1. Mitochondrial DNA Analyses Indicate High Diversity, Expansive Population Growth and High Genetic Connectivity of Vent Copepods (Dirivultidae) across Different Oceans. (United States)

    Gollner, Sabine; Stuckas, Heiko; Kihara, Terue C; Laurent, Stefan; Kodami, Sahar; Martinez Arbizu, Pedro


    Communities in spatially fragmented deep-sea hydrothermal vents rich in polymetallic sulfides could soon face major disturbance events due to deep-sea mineral mining, such that unraveling patterns of gene flow between hydrothermal vent populations will be an important step in the development of conservation policies. Indeed, the time required by deep-sea populations to recover following habitat perturbations depends both on the direction of gene flow and the number of migrants available for re-colonization after disturbance. In this study we compare nine dirivultid copepod species across various geological settings. We analyze partial nucleotide sequences of the mtCOI gene and use divergence estimates (FST) and haplotype networks to infer intraspecific population connectivity between vent sites. Furthermore, we evaluate contrasting scenarios of demographic population expansion/decline versus constant population size (using, for example, Tajima's D). Our results indicate high diversity, population expansion and high connectivity of all copepod populations in all oceans. For example, haplotype diversity values range from 0.89 to 1 and FST values range from 0.001 to 0.11 for Stygiopontius species from the Central Indian Ridge, Mid Atlantic Ridge, East Pacific Rise, and Eastern Lau Spreading Center. We suggest that great abundance and high site occupancy by these species favor high genetic diversity. Two scenarios both showed similarly high connectivity: fast spreading centers with little distance between vent fields and slow spreading centers with greater distance between fields. This unexpected result may be due to some distinct frequency of natural disturbance events, or to aspects of individual life histories that affect realized rates of dispersal. However, our statistical performance analyses showed that at least 100 genomic regions should be sequenced to ensure accurate estimates of migration rate. Our demography parameters demonstrate that dirivultid

  2. Community Structure of Macrobiota and Environmental Parameters in Shallow Water Hydrothermal Vents off Kueishan Island, Taiwan.

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    Benny Kwok Kan Chan

    Full Text Available Hydrothermal vents represent a unique habitat in the marine ecosystem characterized with high water temperature and toxic acidic chemistry. Vents are distributed at depths ranging from a few meters to several thousand meters. The biological communities of shallow-water vents have, however, been insufficiently studied in most biogeographic areas. We attempted to characterize the macrofauna and macroflora community inhabiting the shallow-water vents off Kueishan Island, Taiwan, to identify the main abiotic factors shaping the community structure and the species distribution. We determined that positively buoyant vent fluid exhibits a more pronounced negative impact to species on the surface water than on the bottom layer. Species richness increased with horizontal distance from the vent, and continuing for a distance of 2000 m, indicating that the vent fluid may exert a negative impact over several kilometers. The community structure off Kueishan Island displayed numerous transitions along the horizontal gradient, which were broadly congruent with changes in environmental conditions. Combination of variation in Ca2+, Cl-, temperature, pH and depth were revealed to show the strongest correlation with the change in benthic community structure, suggesting multiple factors of vent fluid were influencing the associated fauna. Only the vent crabs of Kueishan Island may have an obligated relationship with vents and inhabit the vent mouths because other fauna found nearby are opportunistic taxa that are more tolerant to acidic and toxic environments.

  3. Deep-sea hydrothermal vent Epsilonproteobacteria encode a conserved and widespread nitrate reduction pathway (Nap). (United States)

    Vetriani, Costantino; Voordeckers, James W; Crespo-Medina, Melitza; O'Brien, Charles E; Giovannelli, Donato; Lutz, Richard A


    Despite the frequent isolation of nitrate-respiring Epsilonproteobacteria from deep-sea hydrothermal vents, the genes coding for the nitrate reduction pathway in these organisms have not been investigated in depth. In this study we have shown that the gene cluster coding for the periplasmic nitrate reductase complex (nap) is highly conserved in chemolithoautotrophic, nitrate-reducing Epsilonproteobacteria from deep-sea hydrothermal vents. Furthermore, we have shown that the napA gene is expressed in pure cultures of vent Epsilonproteobacteria and it is highly conserved in microbial communities collected from deep-sea vents characterized by different temperature and redox regimes. The diversity of nitrate-reducing Epsilonproteobacteria was found to be higher in moderate temperature, diffuse flow vents than in high temperature black smokers or in low temperatures, substrate-associated communities. As NapA has a high affinity for nitrate compared with the membrane-bound enzyme, its occurrence in vent Epsilonproteobacteria may represent an adaptation of these organisms to the low nitrate concentrations typically found in vent fluids. Taken together, our findings indicate that nitrate reduction is widespread in vent Epsilonproteobacteria and provide insight on alternative energy metabolism in vent microorganisms. The occurrence of the nap cluster in vent, commensal and pathogenic Epsilonproteobacteria suggests that the ability of these bacteria to respire nitrate is important in habitats as different as the deep-sea vents and the human body.

  4. The origin of life in alkaline hydrothermal vents (United States)

    Sojo, V.; Herschy, B.; Whicher, A.; Camprubí, E.; Lane, N.


    The origin of life remains one of Science's greatest unresolved questions. The answer will no doubt involve almost all the basic disciplines, including Physics, Chemistry, Astronomy, Geology, and Biology. Chiefly, it is the link between the latter two that must be elucidated: how geochemistry gave rise to biochemistry. Serpentinizing systems such as alkaline hydrothermal vents offer the most robust combination of conditions to have hosted the origin of life on the early Earth, while bearing many parallels to modern living cells. Stark gradients of concentration, pH, oxidation/reduction, and temperature provided the ability to synthesise and concentrate organic products, drive polymerisation reactions, and develop an autotrophic lifestyle independent of foreign sources of organics. In the oxygen-depleted waters of the Hadean, alkaline vents would have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with the relatively acidic CO2-rich waters of the ocean, through interconnected micropores made of thin inorganic walls containing catalytic Fe(Ni)S minerals. Perhaps not coincidentally, the unit cells of these Fe(Ni)S minerals closely resemble the active sites of crucial ancestral bioenergetic enzymes. Meanwhile, differences in pH across the thin barriers produced natural proton gradients similar to those used for carbon fixation in modern archaea and bacteria. At the earliest stages, the problem of the origin of life is the problem of the origin of carbon fixation. I will discuss work over the last decade that suggests several possible hypotheses for how simple one-carbon molecules could have given rise to more complex organics, particularly within a serpentinizing alkaline hydrothermal vent. I will discuss the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria, thought to be the earliest representatives of each domain, to propose a possible ancestral mechanism of CO2 reduction in

  5. Formation of Zn- and Fe-sulfides near hydrothermal vents at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs

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    Yucel Mustafa


    Full Text Available Abstract Background The speciation of dissolved sulfide in the water immediately surrounding deep-ocean hydrothermal vents is critical to chemoautotrophic organisms that are the primary producers of these ecosystems. The objective of this research was to identify the role of Zn and Fe for controlling the speciation of sulfide in the hydrothermal vent fields at the Eastern Lau Spreading Center (ELSC in the southern Pacific Ocean. Compared to other well-studied hydrothermal systems in the Pacific, the ELSC is notable for unique ridge characteristics and gradients over short distances along the north-south ridge axis. Results In June 2005, diffuse-flow ( 250°C vent fluids were collected from four field sites along the ELSC ridge axis. Total and filtered Zn and Fe concentrations were quantified in the vent fluid samples using voltammetric and spectrometric analyses. The results indicated north-to-south variability in vent fluid composition. In the high temperature vent fluids, the ratio of total Fe to total Zn varied from 39 at Kilo Moana, the most northern site, to less than 7 at the other three sites. The concentrations of total Zn, Fe, and acid-volatile sulfide indicated that oversaturation and precipitation of sphalerite (ZnS(s and pyrite (FeS2(s were possible during cooling of the vent fluids as they mixed with the surrounding seawater. In contrast, most samples were undersaturated with respect to mackinawite (FeS(s. The reactivity of Zn(II in the filtered samples was tested by adding Cu(II to the samples to induce metal-exchange reactions. In a portion of the samples, the concentration of labile Zn2+ increased after the addition of Cu(II, indicating the presence of strongly-bound Zn(II species such as ZnS clusters and nanoparticles. Conclusion Results of this study suggest that Zn is important to sulfide speciation at ELSC vent habitats, particularly at the southern sites where Zn concentrations increase relative to Fe. As the hydrothermal

  6. VOC transport in vented drums containing simulated waste sludge

    Energy Technology Data Exchange (ETDEWEB)

    Liekhus, K.J.; Gresham, G.L.; Rae, C.; Connolly, M.J.


    A model is developed to estimate the volatile organic compound (VOC) concentration in the headspace of the innermost layer of confinement in a lab-scale vented waste drum containing simulated waste sludge. The VOC transport model estimates the concentration using the measured VOC concentration beneath the drum lid and model parameters defined or estimated from process knowledge of drum contents and waste drum configuration. Model parameters include the VOC diffusion characteristic across the filter vent, VOC diffusivity in air, size of opening in the drum liner lid, the type and number of layers of polymer bags surrounding the waste, VOC permeability across the polymer, and the permeable surface area of the polymer bags. Comparison of model and experimental results indicates that the model can accurately estimate VOC concentration in the headspace of the innermost layer of confinement. The model may be useful in estimating the VOC concentration in actual waste drums.

  7. Catalytic Diversity in Alkaline Hydrothermal Vent Systems on Ocean Worlds (United States)

    Cameron, Ryan D.; Barge, Laura; Chin, Keith B.; Doloboff, Ivria J.; Flores, Erika; Hammer, Arden C.; Sobron, Pablo; Russell, Michael J.; Kanik, Isik


    Hydrothermal systems formed by serpentinization can create moderate-temperature, alkaline systems and it is possible that this type of vent could exist on icy worlds such as Europa which have water-rock interfaces. It has been proposed that some prebiotic chemistry responsible for the emergence of life on Earth and possibly other wet and icy worlds could occur as a result ofredox potential and pH gradients in submarine alkaline hydrothermal vents (Russell et al., 2014). Hydrothermal chimneys formed in laboratory simulations of alkaline vents under early Earth conditions have precipitate membranes that contain minerals such as iron sulfides, which are hypothesized to catalyze reduction of CO2 (Yamaguchi et al. 2014, Roldan et al. 2014) leading to further organic synthesis. This CO2 reduction process may be affected by other trace components in the chimney, e.g. nickel or organic molecules. We have conducted experiments to investigate catalytic properties of iron and iron-nickel sulfides containing organic dopants in slightly acidic ocean simulants relevant to early Earth or possibly ocean worlds. We find that the electrochemical properties of the chimney as well as the morphology/chemistry of the precipitate are affected by the concentration and type of organics present. These results imply that synthesis of organics in water-rock systems on ocean worlds may lead to hydrothermal precipitates which can incorporate these organic into the mineral matrix and may affect the role of gradients in alkaline vent systems.Therefore, further understanding on the electroactive roles of various organic species within hydrothermal chimneys will have important implications for habitability as well as prebiotic chemistry. This work is funded by NASA Astrobiology Institute JPL Icy Worlds Team and a NAI Director's Discretionary Fund award.Yamaguchi A. et al. (2014) Electrochimica Acta, 141, 311-318.Russell, M. J. et al. (2014), Astrobiology, 14, 308-43.Roldan, A. (2014) Chem. Comm. 51

  8. Primer registro de artropodofauna cadavérica en sustratos humanos y animales en San Juan, Argentina First record of cadaverous arthropod fauna in human and animal substrates in San Juan, Argentina

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    Fernando H. Aballay


    Full Text Available En el presente trabajo se estudiaron los artrópodos carroñeros que acudieron a cadáveres de vertebrados al aire libre en la provincia de San Juan, Argentina. El objetivo fue inventariar la composición específica de la artropodofauna cadavérica, asociada a diferentes sustratos de vertebrados en descomposición. Se colectaron muestras de artrópodos sobre restos animales y humanos en condiciones de campo y sobre cadáveres de cerdos domésticos colocados al aire libre bajo condiciones controladas. Se registraron, por primera vez para la provincia de San Juan, 40 especies de artropodofauna tanatológica incluidas en cuatro órdenes y 15 familias. Se incorpora, como primera cita para la fauna forense argentina, un necrófago: Megelenophorus americanus Lacordaire (Coleoptera: Tenebrionidae, y tres necrófilas: Polybia ruficeps Schrottky (Hymenoptera: Vespidae, Pheidole bergi Mayr (Hymenoptera, Formicidae, Myrmicinae y Ectatomma brunneum Smith (Hymenoptera, Formicidae, Ponerinae. Se citan 18 especies necrófagas, 18 necrófilas, una omnívora y seis oportunistas sobre siete diferentes sustratos cadavéricos de vertebrados. Se brindan nuevos registros de distribución de 18 especies de insectos. Se confirma la estacionalidad invernal de Callíphora vicina Robineau-Desvoidy (Diptera: Calliphoridae.In order to determine the specific composition of cadaverous arthropod fauna associated to different decomposing vertebrate substrates, we studied the carrion arthropods that feed on outdoor carcasses in San Juan province, Argentina. Arthropods were collected on animal and human remains in the field and on carcasses of domestic pig placed outdoors under controlled conditions. Forty species of carrion arthropods belonging to four orders and 15 families were recorded for the first time in this province. We present the first record of forensic fauna in Argentina of the necrophagous species Megelenophorus americanus (Coleoptera: Tenebrionidae and three

  9. Indigenous ectosymbiotic bacteria associated with diverse hydrothermal vent invertebrates. (United States)

    Goffredi, Shana K


    Symbioses involving bacteria and invertebrates contribute to the biological diversity and high productivity of both aquatic and terrestrial environments. Well-known examples from chemosynthetic deep-sea hydrothermal vent environments involve ectosymbiotic microbes associated with the external surfaces of marine invertebrates. Some of these ectosymbioses confer protection or defence from predators or the environment itself, some are nutritional in nature, and many still are of unknown function. Several recently discovered hydrothermal vent invertebrates, including two populations of yeti crab (Kiwa spp.), a limpet (Symmetromphalus aff. hageni), and the scaly-foot snail (as yet undescribed), support a consortium of diverse bacteria. Comparisons of these ectosymbioses to those previously described revealed similarities among the associated microorganisms, suggesting that certain microbes are indigenous to the surfaces of marine invertebrates. In particular, members of the Thiovulgaceae (epsilonproteobacteria) and Thiotrichaceae (gammaproteobacteria) appear to preferentially form ectosymbioses with vent crustaceans and gastropods. Interactions between specific Proteobacteria and the surfaces of many marine invertebrates likely have ecological and evolutionary significance at these chemically challenging habitats. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

  10. Performance of carbon dioxide vent for direct methanol fuel cells (United States)

    Prakash, Shruti; Kohl, Paul A.

    Direct methanol fuel cells have potentially high energy density if the balance of plant and fuel losses can be kept to a minimum. CO 2 accumulation in the fuel tank can lower the efficiency and performance of closed-tank methanol fuel cells. This report discusses the implementation of a passive CO 2 vent fabricated with poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane. The performance of the membrane as a selective vent for carbon dioxide in the presence of methanol has been studied at various operating conditions. First, the selectivity of the vent membrane improved with temperature. Second, the activation energy for permeation through the polymer membrane corresponded to diffusion controlled transport of CO 2 and sorption controlled transport for methanol vapor. The activation energy for CO 2 transport through the poly(1-trimethyl silyl propyne) and 1,6-divinylperfluorohexane membrane was less than that for a pure poly(1-trimethyl silyl propyne) membrane. Finally, the polymer had a high selectivity for carbon dioxide compared to both liquid and vapor phase methanol.

  11. Primary Formation Path of Formaldehyde in Hydrothermal Vents (United States)

    Inaba, Satoshi


    Formaldehyde is abundant in the universe and one of the fundamental molecules for life. Hydrothermal vents produce a substantial amount of hydrogen molecules by serpentinization and promote reductive reactions of single carbon compounds. The abundance of formaldehyde is expected to be low due to the high Gibbs free energy in hydrothermal vents. We consider two competing formation pathways of formaldehyde: (1) the reduction of CO by H2 and (2) the reduction of HCOOH by H2 to form a methanediol, followed by the dehydration of the methanediol. We performed a number of quantum chemical simulations to examine the formation of formaldehyde in the gas phase as well as in aqueous solution. The energy barrier is significantly reduced by the catalytic effect of water molecules in aqueous solution and becomes lowest when a water cluster consisted of 5 water molecules catalyzes the reduction. The energy barrier to form a methanediol by the reduction of HCOOH is lower by 17.5 kcal/mol than that to form a formaldehyde by the reduction of CO. Considering the low energy barrier to dehydrate methanediol, the primary pathway to form formaldehyde in hydrothermal vents is concluded to be the reduction of HCOOH by H2, followed by the dehydration of methanediol.

  12. Reversible Venting Stitch for Fenestrating Valve-less Glaucoma Shunts. (United States)

    Akil, Handan; Vu, Priscilla Q; Nguyen, Anhtuan H; Nugent, Alexander; Chopra, Vikas; Francis, Brian A; Tan, James C


    The purpose of this is to describe a venting stitch modification for valveless glaucoma aqueous shunts and characterize early postoperative intraocular pressure (IOP) and glaucoma medication use following the modification. Retrospective chart review of 61 sequential patients undergoing Baerveldt glaucoma implant (BGI)-350 implantation at the Doheny Eye Institute. Twenty-four patients received a glaucoma shunt with venting stitch modification (modified BGI) and 37 patients received an unmodified shunt (BGI-only). IOP, number of glaucoma medications, and number of hypotony cases (intraocular pressure ≤5 mm Hg) were compared between the groups. T-tests were used for statistical analysis. At postoperative-day 1, mean IOP was significantly lower compared with preoperatively in the modified BGI group (14 mm Hg; reduced by 51%; P<0.0001) but not the BGI-only group (27 mm Hg; P=0.06). IOP difference between groups persisted till immediately before tube opening (P=0.005) and fewer IOP-lowering medications needed in the modified BGI group (P<0.0001). One case (4.2%) of postoperative hypotony was encountered with BGI modification, which resolved after the stitch was removed in clinic. The venting stitch valveless shunt modification allows for effective, reliable, and safe control of early postoperative IOP.

  13. The Effects of Infrared-Blocking Pigments and Deck Venting on Stone-Coated Metal Residential Roofs

    Energy Technology Data Exchange (ETDEWEB)

    Miller, William A [ORNL


    Field data show that stone-coated metal shakes and S-mission tile, which exploit the use of infraredblocking color pigments (IrBCPs), along with underside venting reduce the heat flow penetrating the conditioned space of a residence by 70% compared with the amount of heat flow penetrating roofs with conventional asphalt shingles. Stone-coated metal roof products are typically placed on battens and counter-battens and nailed through the battens to the roof deck. The design provides venting on the underside of the metal roof that reduces the heat flow penetrating a home. The Metal Construction Association (MCA) and its affiliate members installed stone-coated metal roofs with shake and S-mission tile profiles and a painted metal shake roof on a fully instrumented attic test assembly at Oak Ridge National Laboratory (ORNL). Measurements of roof, deck, attic, and ceiling temperatures; heat flows; solar reflectance; thermal emittance; and ambient weather were recorded for each of the test roofs and also for an adjacent attic cavity covered with a conventional pigmented and direct nailed asphalt shingle roof. All attic assemblies had ridge and soffit venting; the ridge was open to the underside of the stone-coated metal roofs. A control assembly with a conventional asphalt shingle roof was used for comparing deck and ceiling heat transfer rates.

  14. Expression patterns of mRNAs for methanotrophy and thiotrophy in symbionts of the hydrothermal vent mussel Bathymodiolus puteoserpentis (United States)

    Wendeberg, Annelie; Zielinski, Frank U; Borowski, Christian; Dubilier, Nicole


    The hydrothermal vent mussel Bathymodiolus puteoserpentis (Mytilidae) from the Mid-Atlantic Ridge hosts symbiotic sulfur- and methane-oxidizing bacteria in its gills. In this study, we investigated the activity and distribution of these two symbionts in juvenile mussels from the Logatchev hydrothermal vent field (14°45′N Mid-Atlantic Ridge). Expression patterns of two key genes for chemosynthesis were examined: pmoA (encoding subunit A of the particulate methane monooxygenase) as an indicator for methanotrophy, and aprA (encoding the subunit A of the dissimilatory adenosine-5′-phosphosulfate reductase) as an indicator for thiotrophy. Using simultaneous fluorescence in situ hybridization (FISH) of rRNA and mRNA we observed highest mRNA FISH signals toward the ciliated epithelium where seawater enters the gills. The levels of mRNA expression differed between individual specimens collected in a single grab from the same sampling site, whereas no obvious differences in symbiont abundance or distribution were observed. We propose that the symbionts respond to the steep temporal and spatial gradients in methane, reduced sulfur compounds and oxygen by modifying gene transcription, whereas changes in symbiont abundance and distribution take much longer than regulation of mRNA expression and may only occur in response to long-term changes in vent fluid geochemistry. PMID:21734728

  15. Metal concentrations in the tissues of the hydrothermal vent mussel Bathymodiolus: reflection of different metal sources. (United States)

    Koschinsky, Andrea; Kausch, Matteo; Borowski, Christian


    Hydrothermal vent mussels of the genus Bathymodiolus are ideally positioned for the use of recording hydrothermal fluxes at the hydrothermal vent sites they inhabit. Barium, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Pb, Sr, and U concentrations in tissue sections of Bathymodiolus mussels from several hydrothermal fields between 15°N and 9°S at the Mid-Atlantic Ridge were determined and compared to the surrounding fluids and solid substrates in the habitats. Elements generally enriched in hydrothermal fluids, such as Fe, Cu, Zn, Pb and Cd, were significantly enriched in the gills and digestive glands of the hydrothermal mussels. The rather small variability of Zn (and Mn) and positive correlation with K and earth alkaline metals may indicate a biological regulation of accumulation. Enrichments of Mo and U in many tissue samples indicate that particulate matter such as hydrothermal mineral particles from the plumes can play a more important role as a metal source than dissolved metals. Highest enrichments of Cu in mussels from the Golden Valley site indicate a relation to the ≥400 °C hot heavy-metal rich fluids emanating in the vicinity. In contrast, mussels from the low-temperature Lilliput field are affected by the Fe oxyhydroxide sediment of their habitat. In a comparison of two different sites within the Logatchev field metal distributions in the tissues reflected small-scale local variations in the metal content of the fluids and the particulate material. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Cartas de Juan Carlos Onetti para Julio Payró =Letters from Juan Carlos Onetti to Julio Payró

    Directory of Open Access Journals (Sweden)

    Lucena, Karina de Castilhos


    Full Text Available Este artigo analisa as cartas enviadas pelo escritor uruguaio Juan Carlos Onetti (1909- 1994 ao crítico de arte argentino Julio Payró (1899-1971 entre 1937 e 1955. A análise desses documentos contradiz uma faceta generalizante presente na fortuna crítica do autor, que o descreve como homem solitário e frio. Nos textos aqui estudados, Onetti manifesta seu carinho e admiração por Payró. Da mesma forma, as cartas oferecem dados que contestam a imagem do Onetti descompromissado, já que ele demonstra preocupação com os rumos da política de seu país. A correspondência também revela inseguranças e vaidades que a figura pública fazia questão de manter escondidas. Nesse sentido, este trabalho sugere que investigações a partir de documentos pessoais de escritores podem ampliar fortemente a interpretação de sua obra e às vezes se opor a juízos estabelecidos pelos críticos que não tiveram acesso a esse material.


    Directory of Open Access Journals (Sweden)

    Alfonso Vargas Rubiano


    Full Text Available

    Hace un tiempo vengo estudiando con fervorosa dedicación la obra pedagógica, sociopolítica, etnológica y cultural de uno de los grandes boyacenses de este siglo, el médico Juan Clímaco Hernández y he encontrado datos muy valiosos de la historia de nuestra educación médica en las postrimerías del pasado siglo y comienzos del actual, que bien valen la pena ser conocidos puesto que las Memorias de Ibáñez terminan en 1884 y el estudio hecho por el Dr. Juan N. Corpas si bien comprende hasta 1922, es muy poco lo que refiere al período que en nuestra historia nacional se conoce como de la Guerra de los 1000 días.


    El 22 de noviembre de 1879, en la solemne sesión de clausura de estudios de la recientemente fundada Facultad de Medicina de la Universidad Nacional de los Estados Unidos de Colombia, recibían el grado de médicos los jóvenes Rodolfo Rueda, Manuel J
    Urruchurtu, Rafael Baquero, Eugenio de la Hoz y Miguel Hernández. Este último, nacido en Santa Marta, de 34 años de edad, había sido maestro de escuela superior en el Departamento del Magdalena, y recién graduado se trasladó a la ciudad de Tunja, como médico del Batallón Bolívar y allí ejerció su profesión hasta su muerte en 1911, alternándola con el periodismo y la política; fue elegido Diputado a la Asamblea de Boyacá en el período 1880-82 por el liberalismo de la provincia. Dicen las crónicas de la época que "a la Botica del Negro Hernández acudían todas las clases sociales, sin distinción alguna, a solicitar sus servicios médicos; los pobres sabían muy bien que en él tenían un defensor de sus derechos, listo siempre a aliviar sus dolores y miserias; y algunos contertulios iban en busca de distracción, charla agradable, tresillo tras los frascos y también, en noches especiales una mesa redonda con carpeta verde dejaba que los dados corriesen libremente


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    Alfredo Jácome Roca


    Full Text Available

    Guardo en mi biblioteca tres libros de tipo biográfico con dedicatoria del autor, el académico Juan Pablo Llinás Cuentas (1924-2011. Investigó este culto colega en los años ochenta sobre la vida de algunos de nuestros prohombres, como Atanasio Girardot, José Hilario López y José Celestino Mutis, siendo este último libro comentado en mi columna semanal de otrora, la del diario barranquillense El Heraldo. Como todos los que llevan los genes Llinás, sus raíces estaban en Sabanalarga, de donde  era también el ilustre profesor y académico César Augusto Pantoja. Me honró Llinás con su amistad (al igual que su hijo Adolfo, el ortopedista. Edgardo Coronado –escritor e historiador de la segunda ciudad del Atlántico (por tamaño, pero la primera en antigüedad y en abolengos– dijo de él que “su experiencia de 30 años como profesor le dio paciencia, entendimiento y sabiduría, lo que le permitió escribir diez libros sobre temas de historia, ética, medicina y filosofía, que fueron su satisfacción y el camino para encontrarse y encontrar a los demás”. 

    Mi contacto personal con Llinás fue precisamente en la década de los ochenta, cuando en su condición de Coordinador del Programa de Ciencias Básicas de la recién fundada Universidad del Norte, me llamó en varias ocasiones para que dictara mis cursos de fisiología endocrina en este centro académico de excelencia, faro de ciencia y de cultura. Su fuerte eran –por supuesto– las humanidades. De vocablo educado y gentiles maneras, Juan Pablo sabía de medicina, de historia, de filosofía, de artes plásticas y de poesía. En un grupo de amigos de las letras y de las artes en Barranquilla, organizaba reuniones con amigos personales como el poeta Eduardo Carranza, o divagaba sobre el significado imaginario de esculturas enigmáticas del maestro Edgar Negret.

     Fue Fundador, Decano y Profesor de la Facultad de Medicina

  19. Entrevista a Juan Rafael Muñoz

    Directory of Open Access Journals (Sweden)

    Ana Mercedes Vernia Carrasco


    de formadores en distintos ámbitos de la formación del profesorado. Autor de numerosas publicaciones sobre didáctica de la música. Compositor y director de la banda de música de la Universidad de Almería Juan Rafael Muñoz Muñoz. Doctor en Ciencias de la Educación y Profesor de Didáctica de la Expresión Musical. Licenciado en Humanidades por la Universidad de Almería y Maestro Especialista en Ciencias Humanas, así como Maestro Especialista en Educación Musical. Miembro del Grupo de Investigación HUM-25. Ha sido Asesor Regional de Música de la Consejería de Educación y Ciencia de la Junta de Andalucía desde el año 1987 hasta el año 2000, en el que se incorporó a la Universidad de Almería. En la actualidad forma parte del Consejo de Dirección de la Revista EUFONÍA, Didáctica de la Música, de la Editorial GRAÓ en Barcelona. Ha participado en la elaboración de los Planes de Estudio de los cuatro Grados que se imparten en la Facultad de Ciencias de la Educación. Es en la actualidad el Coordinador del Área de Expresión Musical. Paralelamente, ha desempeñado el cargo de Director del Secretariado de Actividades Culturales, del Vicerrectorado de Extensión Universitaria; y el de Vicedecano de estudiantes y Cultura de la Facultad de Ciencias de la Educación.

  20. Meteorologically Driven Simulations of Dengue Epidemics in San Juan, PR (United States)

    Morin, Cory W.; Monaghan, Andrew J.; Hayden, Mary H.; Barrera, Roberto; Ernst, Kacey


    Meteorological factors influence dengue virus ecology by modulating vector mosquito population dynamics, viral replication, and transmission. Dynamic modeling techniques can be used to examine how interactions among meteorological variables, vectors and the dengue virus influence transmission. We developed a dengue fever simulation model by coupling a dynamic simulation model for Aedes aegypti, the primary mosquito vector for dengue, with a basic epidemiological Susceptible-Exposed-Infectious-Recovered (SEIR) model. Employing a Monte Carlo approach, we simulated dengue transmission during the period of 2010–2013 in San Juan, PR, where dengue fever is endemic. The results of 9600 simulations using varied model parameters were evaluated by statistical comparison (r2) with surveillance data of dengue cases reported to the Centers for Disease Control and Prevention. To identify the most influential parameters associated with dengue virus transmission for each period the top 1% of best-fit model simulations were retained and compared. Using the top simulations, dengue cases were simulated well for 2010 (r2 = 0.90, p = 0.03), 2011 (r2 = 0.83, p = 0.05), and 2012 (r2 = 0.94, p = 0.01); however, simulations were weaker for 2013 (r2 = 0.25, p = 0.25) and the entire four-year period (r2 = 0.44, p = 0.002). Analysis of parameter values from retained simulations revealed that rain dependent container habitats were more prevalent in best-fitting simulations during the wetter 2010 and 2011 years, while human managed (i.e. manually filled) container habitats were more prevalent in best-fitting simulations during the drier 2012 and 2013 years. The simulations further indicate that rainfall strongly modulates the timing of dengue (e.g., epidemics occurred earlier during rainy years) while temperature modulates the annual number of dengue fever cases. Our results suggest that meteorological factors have a time-variable influence on dengue transmission relative to other important

  1. Abundant Hydrothermal Venting in the Southern Ocean Near 62°S/159°E on the Australian-Antarctic Ridge (United States)

    Baker, E. T.; Hahm, D.; Rhee, T. S.; Park, S. H.; Lupton, J. E.; Walker, S. L.; Choi, H.


    Circum-Antarctic Ridges (CARs) comprise almost one-third of the global Mid-Ocean Ridge, yet remain terra incognita for hydrothermal activity and chemosynthetic ecosystems. The InterRidge Vents Database lists only 3 confirmed (visualized) and 35 inferred (plume evidence) active sites along the ~21,000 km of CARs. Here, we report on a multi-year effort to locate and characterize hydrothermal activity on two 1st-order segments of the Australian-Antarctic Ridge that are perhaps more isolated from other known vent fields than any other vent site on the Mid-Ocean Ridge. KR1 is a 300-km-long segment near 62°S/159°E, and KR2 a 90-km-long segment near 60°S/152.5°E. We used profiles collected by Miniature Autonomous Plume Recorders (MAPRs) on rock corers in March and December of 2011 to survey each segment, and an intensive CTD survey in Jan/Feb 2013 to pinpoint sites and sample plumes on KR1. Optical and oxidation-reduction potential (ORP, aka Eh) anomalies indicate multiple active sites on both segments. Seven profiles on KR2 found 3 sites, each separated by ~25 km. Forty profiles on KR1 identified 13 sites, some within a few km of each other. The densest site concentration on KR1 occurred along a relatively inflated, 90-km-long section near the segment center. CTD tows covered 20 km of the eastern, most inflated portion of this area, finding two 6-km-long zones centered near 158.6°E and 158.8°E with multiple plume anomalies. Three ORP anomalies within 50 m of the seafloor indicate precise venting locations. We call this area the Mujin "Misty Harbor" vent field. Vent frequency sharply decreases away from Mujin. 3He/heat ratios determined from 20 plume samples in the Mujin field were mostly <0.015 fM/J, indicative of chronic venting, but 3 samples, 0.021-0.034 fM/J, are ratios typical of a recent eruption. The spatial density of hydrothermal activity along KR1 and KR2 is similar to other intermediate-rate spreading ridges. We calculate the plume incidence (ph) along

  2. Analysis of design and operational effects of filtered containment venting on depressurization and fission product release

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong Woon; Seol, Wook-Cheol; Kim, Jisu [Dongguk Univ., Gyeongbuk (Korea, Republic of)


    Effects of design and operational parameters of filtered containment venting system during a specified containment depressurization and relative aero sol release amount are analyzed. The analyses is performed by using the MAAP4 code for the APR1400 reactor. Major results uniquely identified from the analyses can be noted as following: Even though containment depressurization is accelerated as the pipe size increases, the venting system solution is also depleted earlier. Elapsed times to reach lower end pressure of 2 bar are nearly identical regardless of the vent initiation pressure and thus early venting is not much beneficial than late venting. Stroke time of the isolation valves has no effect on the depressurization performance and thus slow opening is beneficial for load reduction from the vent effluent.

  3. Buscando el compromiso : la negociación del Pacto de San Juan de Luz

    Directory of Open Access Journals (Sweden)

    Luis Carlos Hernando


    Full Text Available Este trabajo ofrece una visión en detalle del proceso de negociación entre el Partido socialista Obrero Español y la Confederación de Derechas Monárquicas leales a don Juan de Borbón, la cual condujo finalmente a la frágil alianza firmada en el conocido como pacto de San Juan de Luz. El análisis del proceso antedicho, iniciado con el encuentro entre el socialista Prieto y el monárquico Gil Robles en Londres en octubre de 1947 y cerrado en agosto de 1948 en el pueblo francés de San Juan de Luz, sirve para extraer conclusiones sobre el estado objetivo de ambas fuerzas políticas exiliadas, su relación y las causas que llevaron al fracaso de la política de conciliación entre las opuestas fuerzas de la izquierda y derecha liberal española.This work offers a view in detail of the process of negotiation between the Socialist Party of Spanish Workers and the Confederation of Spanish Rightists loyal to don Juan de Borbón, which ultimately led to the fragile alliance signed in the so called San Juan de Luz’s pact. The analysis of the aforementioned process, initiated with the encounter between the socialist Prieto and the monarchist Gil Robles in London in October of 1947 and closed in august of 1948 in the French village of San Juan de Luz, serves to draw conclusions about the real significance of both exiled political forces, their relationship and the causes that led to the fail of the politics of conciliation between the opposed liberal forces of Spanish right and left.

  4. Effect of containment venting on the risk from LWR meltdown accidents

    Energy Technology Data Exchange (ETDEWEB)

    Cybulskis, P.; Wooton, R.O.; Denning, R.S.


    Many of the high-consequence accident sequences in the Reactor Safety Study (WASH-1400) involved containment failure by overpressurization. One way to relieve pressure and avoid containment failure is by venting of the containment atmosphere. The study undertook to develop some quantitative insight into the potential effect on public risk of venting and filtering the containment atmosphere for this class of accidents. The results of the Reactor Safety Study were examined to identify the dominant accident sequences in which containment venting could be expected to have an impact. The effects on fission product release for these sequences due to various modes of venting and/or filtering were then evaluated. The results for these selected dominant sequences were then used as a guide to infer the overall effects of containment venting on reactor accident risks. The potential impact on both the Reactor Safety Study PWR and BWR designs were considered. The results indicate that for the PWR design considered venting alone will not lead to an appreciable reduction in overall risk of reactor meltdown accidents. Filtered venting could reduce the likelihood of the accidents with very high consequences that were found to dominate the risk in WASH-1400. IN PWR accidents involving loss of containment heat removal containment venting could significantly delay the start of core melting and thus offer the possibility to effect repairs and avoid core melting. For the BWR design considered, filtered venting will not lead to an appreciable reducton of overall risk due to the dominance of several transient accident sequences in which venting was found to have little beneficial effect. The maximum benefit that could be derived from filtered venting appears to be about an order of magnitude reduced in risk; beyond this containment modes not affected by venting appear to be controlling.

  5. El anti-don Juan de María de Zayas

    Directory of Open Access Journals (Sweden)

    Trambaioli, Marcella


    Full Text Available All critics agree on considering that María de Zayas writes inspired by the anger that she feels for the women condition. Both in her prose and in the only play we know, La traición en la amistad, Zayas censures with irony and wit the don-Juan type who deceives women leaving them without honour. She does it elaborating an intertextual relationship with El burlador de Sevilla. Specifically, in the play she uses three characters: Liseo, who deceives three women, Fenisa, who is a don-Juan female even more exaggerated than Liseo, and don Juan, the less donjuanesco of all. As a matter of fact, Zayas creates an anti-don Juan similar to the one that Ventura de la Vega will realize in the XIX century with his play El hombre de mundo, a parody of Zorrilla’s Don Juan Tenorio; nevertheless it has a clear ethical purpose: to warn women of his age in order to avoid men’s abuses.Los críticos concuerdan en que María de Zayas escribe inspirada por la cólera que le provoca la condición femenina coetánea. Tanto en sus novelas como en la única comedia conservada, La traición en la amistad, Zayas censura con sutil ironía al tipo donjuanesco que se burla de las mujeres dejándolas sin honor, y lo hace entablando un complejo e ingenioso diálogo intertextual con El burlador de Sevilla. De forma especial, en la pieza lo hace a través de tres figuras: Liseo, que engaña a tres mujeres, Fenisa, un don Juan mujer aún más hiperbólico que Liseo, y don Juan, el menos donjuanesco de todos. En definitiva, crea un anti-don Juan parecido al que Ventura de la Vega realizará en el siglo XIX con El hombre de mundo, parodia del Tenorio de Zorrilla, pero con una clara intencionalidad ética: la de aleccionar a las mujeres de su época para que aprendan a esquivar a los hombres que abusan de ellas.

  6. Entrevista al músico Juan Carlos Panarace sobre la música


    Ilariucci, Virginia; Radio Universidad Nacional de La Plata


    Entrevista de la periodista Virginia Ilariucci para el programa Radiomemoria de radio Universidad al músico argentino Juan Carlos Panarace, con motivo del "Día de la Música". Lo consulta sobre el concepto "música", como arte y como reflejo de la sociedad, la creatividad, la música clásica, popular y la música contemporánea. Una mirada sobre la música "comercial" y los fenómenos de público. Juan Carlos Panarace, nació el 8 de marzo de 1954 en Castelli, provincia de Buenos Aires. Es Licencia...

  7. [The medical world of Juan Gil de Zamora's Historia Naturalis (ca. 1275-1296)]. (United States)

    García Ballester, L; Domínguez, A


    The article describes the authors and works which were quoted by the Franciscan Juan Gil de Zamora in his Historia naturalis, a scientific encyclopaedia written between c. 1275 and before 1296, probably in the Franciscan monastery of Zamora (Kingdom of Castille). Juan Gil made wide use of the Avicenna's Canon, Gilbertus de Aquila (Anglicus)'s Compendium medicine, and Salernitan medical literature. His work contributed to the diffusion of these medical authors and works throughout the Christian intellectual milieu of late medieval Castille. This diffusion was not without problems.

  8. Bancarización de clusters: La experiencia de la provincia de San Juan, Argentina


    Raúl Novoa; Juan Antonio Ketterer; Gabriela Szarfer; Pablo Curat; Leonardo Gioja; Marisú Puerta; Carlos Colabello; Jorge Ramírez; Manuel Prieto; Pablo Sánchez Le Daca; Roxana Matías Gago; Jorge A. Lupano


    El presente documento se basa en la experiencia obtenida a través de la ejecución del Programa de Crédito para el Desarrollo de la Producción y el Empleo en la Provincia de San Juan, Argentina, financiado parcialmente por el BID. Analiza los instrumentos de promoción utilizados para desarrollo de agrupamientos locales de PYMES dinámicas (clusters), verificando que --a diferencia de la experiencia de San Juan-- la asistencia para el acceso al crédito bancario y a otras fuentes de financiamient...

  9. Memoria y desmemoria, pensamiento y poética en la dramaturgia de Juan Mayorga


    March Tortajada, Robert


    En Memoria y desmemoria, pensamiento y poética en la dramaturgia de Juan Mayorga nos hemos adentrado en los puntos de contacto entre filosofía y teatro para, a partir de ahí, ver cómo éstos son permeables. Nuestra investigación se ha interesado en el diálogo, en la intertextualidad, en ver cómo las piezas dramáticas de Juan Mayorga se relacionan unas con otras y desestabilizan, sobre todo, aquello que creemos saber. Si de la palabra teatral del autor nos interesa la desconfianza hacia el leng...

  10. PUBLIC ART - Juan Soriano in the main square (Zócalo): an experience of contemporary


    Hernández Sánchez, Adriana


    This research is trying to spread the experience of a temporary exhibition of contemporary art in the most important public site from the historical City of Puebla-Mexico, named “Los sueños moldeados de Juan Soriano” (The manageable dreams from Juan Soriano) carried out by Instituto Municipal de Arte y Cultura (Municipal Institute of Art and Culture) from the Town Council of Puebla City, from April 21st to June 26th, 2006, within the setting of the festivities for the 475 years of the City fo...

  11. Tissue partitioning of micro-essential metals in the vent bivalve Bathymodiolus azoricus and associated organisms (endosymbiont bacteria and a parasite polychaete) from geochemically distinct vents of the Mid-Atlantic Ridge (United States)

    Kádár, Enikõ; Costa, Valentina; Santos, Ricardo S.; Powell, Jonathan J.


    Hydrothermal communities are built on highly specialised organisms possessing effective adaptation mechanisms to tolerate elevated levels of toxic heavy metals typical of these extreme habitats. Bioavailability and tissue compartmentalisation of micro-essential metals (Cu, Zn, and Fe) were investigated in the bivalve Bathymodiolus azoricus from three geochemically distinct hydrothermal vents (Rainbow, Lucky Strike, Menez Gwen). Additionally , in order to make inferences on the effect of biological interactions on the metal uptake, the bivalves' endosymbiont bacteria and commensal parasite Branchipolynoe seepensis were analysed for metal bioaccumulation. Micro-essential metal concentrations in byssus threads exceeded many-fold concentrations in the gill and digestive gland, which in turn were consistently one order of magnitude above levels measured in the mantle. In spite of its high metal concentrations, the byssus is unlikely to be an active bioaccumulator. Its high surface to mass ratio and its binding sites for metals suggest a reversible adsorption of micro-essential metals in the vent mussel. Inter-site comparison showed highest Fe concentrations in tissues of mussels from the Rainbow site, whereas Zn and Cu in all tissues were highest in mussels from the Lucky Strike site, reflecting metal concentrations in the water surrounding macro-invertebrates at these vent sites. The omnipresence of the commensal parasite polychaete in gills of B. azoricus from the Lucky Strike vent field, unlike the other sites, is suggested to be an adaptation to the typically elevated Fe concentrations in the water column near mussel beds. Unprecedented Fe concentrations measured in the digestive gland of mussels from the Rainbow site (4000 μg g - 1 , three times higher than levels in bivalves from polluted sites) call for further post-capture ecotoxicological investigations of potentially novel Fe-handling strategies. We provide the first information on the bioaccumulation

  12. Zero Gravity Cryogenic Vent System Concepts for Upper Stages (United States)

    Ravex, Alain; Flachbart, Robin; Holt, Barney

    The capability to vent in zero gravity without resettling is a technology need that involves practically all uses of sub-critical cryogenics in space. Venting without resettling would extend cryogenic orbital transfer vehicle capabilities. However, the lack of definition regarding liquid/ullage orientation coupled with the somewhat random nature of the thermal stratification and resulting pressure rise rates, lead to significant technical challenges. Typically a zero gravity vent concept, termed a thermodynamic vent system (TVS), consists of a tank mixer to destratify the propellant, combined with a Joule-Thomson (J-T) valve to extract thermal energy from the propellant. Marshall Space Flight Center's (MSFC's) Multipurpose Hydrogen Test Bed (MHTB) was used to test both spray bar and axial jet TVS concepts. The axial jet system consists of a recirculation pump heat exchanger unit. The spray bar system consists of a recirculation pump, a parallel flow concentric tube, heat exchanger, and a spray bar positioned close to the longitudinal axis of the tank. The operation of both concepts is similar. In the mixing mode, the recirculation pump withdraws liquid from the tank and sprays it into the tank liquid, ullage, and exposed tank surfaces. When energy extraction is required, a small portion of the recirculated liquid is passed sequentially through the J-T expansion valve, the heat exchanger, and is vented overboard. The vented vapor cools the circulated bulk fluid, thereby removing thermal energy and reducing tank pressure. The pump operates alone, cycling on and off, to destratify the tank liquid and ullage until the liquid vapor pressure reaches the lower set point. At that point, the J-T valve begins to cycle on and off with the pump. Thus, for short duration missions, only the mixer may operate, thus minimizing or even eliminating boil-off losses. TVS performance testing demonstrated that the spray bar was effective in providing tank pressure control within a 6

  13. Evolution and biogeography of deep-sea vent and seep invertebrates. (United States)

    Van Dover, C L; German, C R; Speer, K G; Parson, L M; Vrijenhoek, R C


    Deep-sea hydrothermal vents and cold seeps are submarine springs where nutrient-rich fluids emanate from the sea floor. Vent and seep ecosystems occur in a variety of geological settings throughout the global ocean and support food webs based on chemoautotrophic primary production. Most vent and seep invertebrates arrive at suitable habitats as larvae dispersed by deep-ocean currents. The recent evolution of many vent and seep invertebrate species (<100 million years ago) suggests that Cenozoic tectonic history and oceanic circulation patterns have been important in defining contemporary biogeographic patterns.

  14. Physiological impacts of acute Cu exposure on deep-sea vent mussel Bathymodiolus azoricus under a deep-sea mining activity scenario. (United States)

    Martins, Inês; Goulart, Joana; Martins, Eva; Morales-Román, Rosa; Marín, Sergio; Riou, Virginie; Colaço, Ana; Bettencourt, Raul


    Over the past years, several studies have been dedicated to understanding the physiological ability of the vent mussel Bathymodiolus azoricus to overcome the high metal concentrations present in their surrounding hydrothermal environment. Potential deep-sea mining activities at Azores Triple junction hydrothermal vent deposits would inevitably lead to the emergence of new fluid sources close to mussel beds, with consequent emission of high metal concentrations and potential resolubilization of Cu from minerals formed during the active phase of the vent field. Copper is an essential metal playing a key role in the activation of metalloenzymes and metalloproteins responsible for important cellular metabolic processes and tissue homeostasis. However, excessive intracellular amounts of reactive Cu ions may cause irreversible damages triggering possible cell apoptosis. In the present study, B. azoricus was exposed to increasing concentrations of Cu for 96h in conditions of temperature and hydrostatic pressure similar to those experienced at the Lucky Strike hydrothermal vent field. Specimens were kept in 1L flasks, exposed to four Cu concentrations: 0μg/L (control), 300, 800 and 1600μg/L and pressurized to 1750bar. We addressed the question of how increased Cu concentration would affect the function of antioxidant defense proteins and expression of antioxidant and immune-related genes in B. azoricus. Both antioxidant enzymatic activities and gene expression were examined in gills, mantle and digestive gland tissues of exposed vent mussels. Our study reveals that stressful short-term Cu exposure has a strong effect on molecular metabolism of the hydrothermal vent mussel, especially in gill tissue. Initially, both the stress caused by unpressurization or by Cu exposure was associated with high antioxidant enzyme activities and tissue-specific transcriptional up-regulation. However, mussels exposed to increased Cu concentrations showed both antioxidant and immune

  15. AREVA’s Containment Venting Technologies and Experience Worldwide

    Energy Technology Data Exchange (ETDEWEB)

    Welker, M.


    The AREVA Filtered Containment Venting System (FCVS) is a product family that minimizes the environmental impact in case of a severe accident in a nuclear power plant (NPP). Our experience is based on a large-scale test and qualification program as well as on the design, licensing and installation of more than 80 projects worldwide. The product family provides flexibility regarding the adaptation to respective accident scenarios, applicable codes and standards, seismic design, supply chain, implementation and localization. AREVA has broad experience of managing fleet supplies, successful support of licensing and cooperating with original equipment manufacturers (OEMs) of pressurized and boiling water reactors (PWR and BWR). (Author)

  16. Measurements of energy exchange between acoustic fields and non-uniform steady flow fields


    Magiawala, K. R.; Culick, F. E. C.


    This paper describes an experimental investigation of interactions between acoustic waves and a non-uniform steady flow field. Data have been obtained for a resonance tube having a vent at the center in the lateral boundary, an average flow being introduced at the ends. Experiments have been done for both circular and slot vents, over ranges of both frequency and Mach number. According to the one-dimensional linear stability analysis, the interactions between the longitudinal a...

  17. Compact autonomous voltammetric sensor for sulfide monitoring in deep sea vent habitats (United States)

    Contreira-Pereira, Leonardo; Yücel, Mustafa; Omanovic, Dario; Brulport, Jean-Pierre; Le Bris, Nadine


    In situ chemical monitoring at deep-sea hydrothermal vents remains a challenge. Particularly, tools are still scarce for assessing the ranges and temporal variability of sulfide in these harsh environmental conditions. There is a particular need for compact and relatively simple devices to enlarge the capacity of in situ measurements of this major energy source in chemosynthetic ecosystems. With this objective, a voltammetric sensor based on a bare-silver working electrode was developed and tested in real conditions. In the laboratory, the sensor presented a linear response from 10 to 1000 μM sulfide, together with a low pH sensitivity and moderate temperature dependence. The device was operated at 850 and 2500 m depth during 3 cruises over two different vent fields. The autonomous potentiostat (290 mm length, ∅ 35 mm) equipped with laboratory-made electrodes was mounted on a wand, for manipulation from a submersible, or on a holder for unattended deployments. The system was applied in mussel, tubeworm and annelid worm habitats, characterized by different ranges of sulfide concentration, pH and temperature. Calibrations performed before and after each deployment confirmed the stability of the sensor response over a few hours to 11 days, with a maximum drift of 11.4% during this period. Short-term measurements in the vicinity of Riftia pachyptila and Alvinella pompejana were consistent with previous results on these habitats, with concentrations ranging from 20 to 140 μM and 100 to 450 μM and sulfide versus temperature ratio of 14 μM °C-1 and 20 μM °C-1, respectively. A continuous 4-day record on a bed of Bathymodiolus Thermophilus mussels furthermore illustrated the capacity of the sensor to capture fluctuating sulfide concentration between 0 and 70 μM, in combination to temperature, and to investigate the changes in the sulfide versus temperature ratio over time. The method has a higher detection limit (<10 μM) than previous in situ sulfide measurement


    Directory of Open Access Journals (Sweden)

    Marcela Cristina Quinteros


    Full Text Available Juan Natalicio González was a Paraguayan intellectual, identified with the historical revisionism and the Colorado Party. He played a central role in spreading this historical revisionism over his country’s frontiers, through of different activities during the early decades of the XX century, until his death in 1966. In this article, we will examine the González’s letters to his master Juan Emiliano O’Leary, the main referent of Paraguayan historical revisionism, those were written in the first years of his intellectual and political life, during the 1920’s. The goals of this text are the study of the literary, editorial and political projects of Natalicio González and the understanding of the relation between González and O’Leary. The reading of these letters enables us to recognize that the literature, the journalism and the editorial work were tools used by González to achieve his political ambitions. These letters were elaborated when González lived in Buenos Aires and they show the way to he practiced his politics inside and outside Paraguay. Finally, these sources aid to identify the autonomy of González to decide his own projects. This article is part of an investigation about the Juan Natalicio González’s trajectory as a Latin-American plural intellectual.

  19. Metaproteomic Analysis of a Chemosynthetic Hydrothermal Vent Community Reveals Insights into Key-Metabolic Processes (United States)

    Steen, I.; Stokke, R.; Lanzen, A.; Pedersen, R.; Øvreås, L.; Urich, T.


    In 2005 researchers at the Centre for Geobiology, University of Bergen, Norway, discovered two active vent fields at the southwestern Mohns Ridge in the Norwegian-Greenland Sea. The fields harbours both low-temperature iron deposits and high-temperature white smoker vents. Distinct microbial mats were abundantly present and located in close vicinity to the hydrothermal vent sites. Characteristics of the mat environment were steep physical and chemical gradients with temperatures ranging from 10°C in the top layer to 90°C at 10 cm bsf and high concentrations of hydrogen sulfide and methane. The work presented here focus on the In situ community activities, and is part of an integrated strategy combining metagenomics, metatranscriptomics and metaproteomics to in-depth characterise these newly discovered hydrothermal vent communities. Extracted proteins were separated via SDS-PAGE. Peptides extracted after In-gel tryptic digest was injected into an Ultimate 3000 nanoLC system connected to a linear quadropole ion trap-orbitrap (LTQ-Orbitrap XL) mass spectrometer equipped with a nanoelectrospray ion source. A custom database of open reading frames (ORFs) from the combined metatranscriptome and metagenome datasets was implemented and searched against using Mascot 2.2; the IRMa tool box [1] was used in peptide validation. Validated ORFs were subjected to a Blastp search against Refseq with an E-value cut-off of 0.001. A total of 1097 proteins with ≥ 2 peptides were identified of which 921 gave a hit against Refseq, containing 519 unique proteins. Key enzymes of the sulfur oxidation pathway (sox) were found, which were taxonomically affiliated to Epsilonproteobacteria. In addition, this group actively expressed hydrogenases and membrane proteins involved in aerobic and anaerobic respiratory chains. Enzymes of dissimilatory sulfate-reduction (APS-reductase, AprAB and DsrA2) were found with closest hit to members of the Deltaproteobacteria. These findings indicate an

  20. A Review of the Incidence and Consequences of Cigarette Filter Vent Blocking Among Smokers

    Directory of Open Access Journals (Sweden)

    Baker RR


    Full Text Available Vent blocking, the covering of the filter ventilation zone on a cigarette during smoking, is a potentially important aspect of smoking behavior. Various techniques have been used to assess the incidence of vent blocking, and widely different views have been expressed on its importance. Studies relevant to filter vent blocking have been reviewed with two overall objectives: to examine critically the evidence on the occurrence of vent blocking and to assess the effects of vent blocking on the smoke yield to the smoker. The reviewed studies fall into four main categories: (1 measurements of the incidence of filter vent blocking among smokers; (2 the observed effects of vent blocking on cigarette ventilation and machine smoke yields; (3 the effect of experimentally blocking vents on human smoke yields; and (4 simultaneous determination of vent blocking and smoke yield under human smoking conditions. Direct observation indicates that only 4% of smokers have their fingers in direct contact with the cigarette during puffing. Estimates of vent blocking incidence by lips during smoking range from 15-24% (saliva-staining technique to up to 50% ('tar’ staining pattern technique of smokers. For those smokers who do block the ventilation zone, a mean of 27% of the vents are blocked, and a maximum of about 50%. When the cigarettes are machine-smoked, the smoke yield increases in a highly non-linear manner as the blocked portion of the filter ventilation zone increases. This effect is also more pronounced at higher original filter ventilation levels. In contrast, smoking behavior monitoring techniques have shown that when the experimenter deliberately blocks the vent zone, the human smoker adjusts by taking smaller and fewer puffs. The blocked filter affects the yields of smoke components to the smoker less than it does smoking-machine measured yields. It is concluded that the incidence of vent zone blocking by fingers is quite low and relatively

  1. Microbial diversity in nonsulfur, sulfur and iron geothermal steam vents. (United States)

    Benson, Courtney A; Bizzoco, Richard W; Lipson, David A; Kelley, Scott T


    Fumaroles, commonly called steam vents, are ubiquitous features of geothermal habitats. Recent studies have discovered microorganisms in condensed fumarole steam, but fumarole deposits have proven refractory to DNA isolation. In this study, we report the development of novel DNA isolation approaches for fumarole deposit microbial community analysis. Deposit samples were collected from steam vents and caves in Hawaii Volcanoes National Park, Yellowstone National Park and Lassen Volcanic National Park. Samples were analyzed by X-ray microanalysis and classified as nonsulfur, sulfur or iron-dominated steam deposits. We experienced considerable difficulty in obtaining high-yield, high-quality DNA for cloning: only half of all the samples ultimately yielded sequences. Analysis of archaeal 16S rRNA gene sequences showed that sulfur steam deposits were dominated by Sulfolobus and Acidianus, while nonsulfur deposits contained mainly unknown Crenarchaeota. Several of these novel Crenarchaeota lineages were related to chemoautotrophic ammonia oxidizers, indicating that fumaroles represent a putative habitat for ammonia-oxidizing Archaea. We also generated archaeal and bacterial enrichment cultures from the majority of the deposits and isolated members of the Sulfolobales. Our results provide the first evidence of Archaea in geothermal steam deposits and show that fumaroles harbor diverse and novel microbial lineages. © 2011 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  2. Phenotypic variation and fitness in a metapopulation of tubeworms (Ridgeia piscesae Jones at hydrothermal vents.

    Directory of Open Access Journals (Sweden)

    Verena Tunnicliffe

    Full Text Available We examine the nature of variation in a hot vent tubeworm, Ridgeia piscesae, to determine how phenotypes are maintained and how reproductive potential is dictated by habitat. This foundation species at northeast Pacific hydrothermal sites occupies a wide habitat range in a highly heterogeneous environment. Where fluids supply high levels of dissolved sulphide for symbionts, the worm grows rapidly in a "short-fat" phenotype characterized by lush gill plumes; when plumes are healthy, sperm package capture is higher. This form can mature within months and has a high fecundity with continuous gamete output and a lifespan of about three years in unstable conditions. Other phenotypes occupy low fluid flux habitats that are more stable and individuals grow very slowly; however, they have low reproductive readiness that is hampered further by small, predator cropped branchiae, thus reducing fertilization and metabolite uptake. Although only the largest worms were measured, only 17% of low flux worms were reproductively competent compared to 91% of high flux worms. A model of reproductive readiness illustrates that tube diameter is a good predictor of reproductive output and that few low flux worms reached critical reproductive size. We postulate that most of the propagules for the vent fields originate from the larger tubeworms that live in small, unstable habitat patches. The large expanses of worms in more stable low flux habitat sustain a small, but long-term, reproductive output. Phenotypic variation is an adaptation that fosters both morphological and physiological responses to differences in chemical milieu and predator pressure. This foundation species forms a metapopulation with variable growth characteristics in a heterogeneous environment where a strategy of phenotypic variation bestows an advantage over specialization.

  3. Trace Metal and Sulfur Dynamics in the First Meter of Buoyant Hydrothermal Vent Plumes (United States)

    Findlay, A.; Gartman, A.; Shaw, T. J.; Luther, G. W., III


    The speciation and reactivity of metals and metal sulfides within the buoyant plume is critical to determining the ultimate fate of metals emitted from hydrothermal vents. The concentration, size fractionation, and partitioning of trace metals (Fe, Mn, Cu, Co, Zn, Cd, Pb) were determined within the first meter of the rising plume at three vent fields (TAG, Snakepit, and Rainbow) along the Mid-Atlantic Ridge. At Rainbow, total Fe concentrations exceed total sulfide concentrations by an order of magnitude, whereas at the other two sites, total Fe and total sulfide concentrations are nearly equal. At all three sites, Mn and Fe are primarily in the filtered (copper is correlated with unfiltered cobalt, and unfiltered zinc is correlated with unfiltered cadmium and lead. At Rainbow, unfiltered zinc, cadmium and lead are correlated, but unfiltered copper and cobalt are not, indicating precipitation dynamics at Rainbow are different than those at TAG and Snakepit due to bulk geochemical differences, including a higher iron to sulfide ratio. A sequential HCl/HNO3 leaching method was used to distinguish metals present in pyrite and chalcopyrite in both unfiltered and filtered samples. Significant portions of unfiltered Cu and Co were extracted in HNO3, whereas unfiltered Zn, Cd, and Pb were extracted in HCl. Up to 95 % of filtered Cu, Co, and Zn, up to 80% Cd, and up to 60 % Pb are only extractable in HNO3, indicating that a significant portion of metals < 0.2 μm are incorporated into a recalcitrant fraction such as nanoparticulate pyrite or chalcopyrite.

  4. Gas Release Near Bullseye Vent - New Observations From NEPTUNE Canada's Seafloor Cable (United States)

    Scherwath, M.; Spence, G.; Riedel, M.; Heesemann, M.


    Over the past six years many marine expeditions to the area of Bullseye Vent region at the Cascadia margin off Vancouver Island have provided evidence of intense degassing at the seafloor above gas hydrate fields. These gas plumes have usually been imaged with ship-based echosounders at frequencies of 12-38 kHz and also with remotely operated vehicles (ROVs) sector-scanning 675 kHz sonars. These intermittent observations show that plume activity varied from visit to visit in size and location, from the absence of bubbles or small plumes to large plumes from multiple sources raising to water depths of up to 500 m below the surface. However, long time intervals without any observations existed between funding cycles and cruises, and so a complete picture of degassing was lacking. Since the installation of the North-East Pacific Time-series Undersea Networked Experiments (NEPTUNE) Canada cabled observatory it is now possible to make permanent long-term observations on a continuous basis and compile a complete series of degassing observations that fill the gap in expedition-based monitoring. At NEPTUNE Canada's Site ODP 889 near Bullseye Vent a permanent 260 kHz multibeam sonar has been installed in May 2010 for initially one year, and since July 2012 rotational capability for a 360 degrees view has been available. We show correlations of degassing with currents, tidal pressure and ocean floor shaking. We also provide an overview of the underlying geologic structures and show our interpretation of degassing associated with faulting as well as recent erosion and outcropping sand-rich layers that feed the gas up the system.

  5. The potential for alternative transportation at Chimney Rock, San Juan National Forest (United States)


    Increased visitation at Chimney Rock in the San Juan National Forest in southwest Colorado has led to increasing interest in the addition of a shuttle system. Piloting a shuttle system at Chimney Rock is a relatively low-cost option that the USFS cou...

  6. Juan Rulfo and Machado de Assis: Toward an Integrated New Narrative (United States)

    Wiseman, David P.; Krause, James R.


    Despite apparent connections between Brazilian and Spanish American narratives, comparative scholarship has only recently begun to investigate actively these important points of contact. In this study, we introduce a vital crossover between the two traditions, involving Juan Rulfo and Joaquim Maria Machado de Assis. Rulfo's outspoken affinity for…

  7. Juan Linz ja eestlane Aleksander Kesküla / Kaido Jaanson

    Index Scriptorium Estoniae

    Jaanson, Kaido, 1940-


    Eestlasest revolutsionääri Aleksander Kesküla elust Hispaanias aastail 1934-1963. Artikli aluseks on A. Kesküla Hispaania-perioodi väheste sõprade, eelkõige tänaseks rahvusvaheliselt tunnustatud sotsioloogi Juan Linz'i meenutused

  8. 77 FR 33239 - Prairie Stewardship Plan/Environmental Impact Statement, San Juan Island National Historical Park (United States)


    ... National Park Service Prairie Stewardship Plan/Environmental Impact Statement, San Juan Island National Historical Park AGENCY: National Park Service, Interior. ACTION: Notice of Intent to Prepare an Environmental... stewardship actions, and nature and extent of potential environmental consequences and appropriate mitigation...

  9. Hurricane recovery at Cabezas de San Juan, Puerto Rico, and research opportunities at Conservation Trust Reserves (United States)

    Peter L. Weaver; Elizabeth Padilla Rodriguez


    The Cabezas de San Juan Natural Reserve (El Faro), an exposed peninsular area located in the Subtropical dry forest of northeastern Puerto Rico, was impacted by hurricanes Hugo (1989) and Georges (1998). From 1998 to 2008, a 0.10 ha plot was used to assess forest structure, species composition, and stem growth. During post-hurricane recovery, stem density, tree height...

  10. 78 FR 72060 - Chimney Rock National Monument Management Plan; San Juan National Forest; Colorado (United States)


    ...; ] DEPARTMENT OF AGRICULTURE Forest Service Chimney Rock National Monument Management Plan; San Juan National...) to establish management direction for the land and resources within Chimney Rock National Monument... establishing Chimney Rock National Monument (the Monument) requires preparation of a management plan. The...

  11. 77 FR 61632 - Final Environmental Impact Statement for Cattle Point Road Relocation, San Juan Island National... (United States)


    ... conditions to aid comparison and analysis of the action alternatives. Unless current management changes... alternative which would continue current road management), and appropriate measures to minimize or avoid harm... release of the Draft EIS was published September 1, 2010, in the Journal of the San Juan Islands. A public...

  12. Tradición y modernidad: la Virgen de San Juan de los Lagos


    Anna M. Fernández Poncela


    The text is about the modern and traditional aspects of the Virgin of San Juan de los Lagos, image and popular religious sanctuary in the state of Jalisco, Mexico. It is a devotion with traditional origin that she goes in increase that agglutinates the regional identity, the religion and the business, and she expands with the migrants to United States.

  13. Colombia kunstnik Juan Manuel Echavarría Tallinnas / Kadri Karro

    Index Scriptorium Estoniae

    Karro, Kadri


    Juan Manuel Echavarría külastab Tallinna 12.-15. aprillini 2011, 13. apr.-l toimub Eesti Kunstiakadeemia Rüütelkonna hoones tema artist talk. Kunstniku holograafiliste trükiste sarjast "Reekviem NN" (2008-2010), mida eksponeeritakse Tallinna 15. graafikatriennaalil Kumu Kunstimuuseumis

  14. The case of the missing vent: lessons in lava flow interpretation from Highway Flow, Craters of the Moon, Idaho (United States)

    Hughes, S. S.; Nawotniak, S. K.; Haberle, C. W.; Downs, M.; Sehlke, A.; Elphic, R. C.; Lim, D. S. S.; Heldmann, J.


    Highway Flow, a latite lava flow at the northern edge of Craters of the Moon National Monument and Preserve in Idaho, appears to have been northward flowing on the basis of its footprint and broad morphology. In plan view, the overall morphology suggests a northward flow in a self-defined channel before finishing in a rounded terminus. Comparison with topographic maps clearly demonstrates, however, that this would require significant uphill travel. We hypothesize, based on topography, alteration, and contacts between flow lobes, that the lava flow emerged from a vent under the highest elevation in the central part of the flow. More detailed ground investigation with the Biologic Analog Science Associated with Lava Terrains (BASALT) and Field Investigations to Enable Solar System Science and Exploration (FINESSE) projects, using Highway flow as an analog for planetary lavas, demonstrates that Highway Flow is actually two separate compound flow lobes, one that flowed mostly westward and the other southward. The western lobe has a circular footprint and is extensively broken by radial fractures. The southern lobe is elongate, with sheared margins and interior ribs perpendicular to flow direction; the ribs include crude ogives and extension cracks. The vent for Highway Flow, previously thought to be buried by North Crater or Big Crater flows to the south or transported tephra from Sunset Cone to the east, is identifiable at the approximate center of the seam between the two lobes using new high-resolution DTMs from UAV flights and alteration patterns observed in the field and via multispectral imagery. Contrasting topographic controls surrounding the vent resulted in very different morphologies for the two lobes, despite emplacement under otherwise similar conditions. These results argue in favor of using multiple datasets, rather than simply using visual orbiter imagery, to interpret lava flow emplacement features on other planetary bodies.

  15. 40 CFR 63.113 - Process vent provisions-reference control technology. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Process vent provisions-reference control technology. 63.113 Section 63.113 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 63.113 Process vent provisions—reference control technology. (a) The owner or operator of a Group 1...

  16. 40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents... § 63.491 Batch front-end process vents—recordkeeping requirements. (a) Group determination records for batch front-end process vents. Except as provided in paragraphs (a)(7) and (a)(8) of this section, each...

  17. 40 CFR 63.450 - Standards for enclosures and closed-vent systems. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards for enclosures and closed... Standards for enclosures and closed-vent systems. (a) Each enclosure and closed-vent system specified in... shall meet the requirements specified in paragraphs (b) through (d) of this section. (b) Each enclosure...

  18. 40 CFR 63.1322 - Batch process vents-reference control technology. (United States)


    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents-reference control technology. 63.1322 Section 63.1322 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Batch process vents—reference control technology. (a) Batch process vents. The owner or operator of a...

  19. Influence of Hydrodynamics on the Larval Supply to Hydrothermal Vents on the East Pacific Rise (United States)


    Distinct patterns of genetic differentiation among annelids of eastern Pacific hydrothermnal vents. Molecular Ecology, 13(9):2603-2615. [17] Jannasch, H...A. Hurtado, R. A. Lutz, and R. C. Vrijenhoek. Distinct patterns of genetic differentiation among annelids of eastern Pacific hydrotherma l vents

  20. 40 CFR 63.765 - Glycol dehydration unit process vent standards. (United States)


    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Glycol dehydration unit process vent... Facilities § 63.765 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to or...

  1. 40 CFR 63.1275 - Glycol dehydration unit process vent standards. (United States)


    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Glycol dehydration unit process vent... Facilities § 63.1275 Glycol dehydration unit process vent standards. (a) This section applies to each glycol dehydration unit subject to this subpart with an actual annual average natural gas flowrate equal to or...

  2. A kinetic model for the pattern and amounts of hydrate precipitated from a gas steam: Application to the Bush Hill vent site, Green Canyon Block 185, Gulf of Mexico (United States)

    Chen, Duo Fu; Cathles, Lawrence M.


    We construct a linear kinetic model of hydrate crystallization from a gas stream. We use this model to predict the fraction of gas that crystallizes as hydrate in the subsurface of Bush Hill, and the depth profile of subsurface hydrate accumulation. This is possible because the Bush Hill vent is fed by reservoir gas from the nearby Jolliet field whose composition is known. On the average, ˜9% of the vent gas is precipitated as hydrate in the subsurface. Although other explanations are possible, the observed vent gas compositions and the greater range of hydrate gas compositions are consistent with a single source gas whose venting rate varies by a factor of at least 3 over periods of a few years or less. The predicted depth profile of hydrate accumulation and the hydrate content of the Bush Hill mound suggest that between ˜1.1 × 109 and 2.8 × 109 m3 (STP) of gas may have accumulated as hydrate between the seafloor and ˜614-m depth. For the radiometrically and geologically suggested system age of 10,000 years, the time average venting rate is ˜106 m3/yr (0.7 × 106 kg/yr). If distributed evenly across the 600 m diameter mound, as suggested by echo sounder images, the methane flux is >3.2 kg/m2 yr. This is >103 times that inferred for hydrates associated with bottom-simulating seismic reflectors. The subsurface hydrate accumulation and the cumulative methane venting are related. We show how both may be estimated from measurements of vent gas composition, bottom water temperature, and geothermal gradient.

  3. Geomicrobiology of Hydrothermal Vents in Yellowstone Lake: Phylogenetic and Functional Analysis suggest Importance of Geochemistry (Invited) (United States)

    Inskeep, W. P.; Macur, R.; Jay, Z.; Clingenpeel, S.; Tenney, A.; Lavalvo, D.; Shanks, W. C.; McDermott, T.; Kan, J.; Gorby, Y.; Morgan, L. A.; Yooseph, S.; Varley, J.; Nealson, K.


    Yellowstone Lake (Yellowstone National Park, WY, USA) is a large, high-altitude, fresh-water lake that straddles the most recent Yellowstone caldera, and is situated on top of significant hydrothermal activity. An interdisciplinary study is underway to evaluate the geochemical and geomicrobiological characteristics of several hydrothermal vent environments sampled using a remotely operated vehicle, and to determine the degree to which these vents may influence the biology of this young freshwater ecosystem. Approximately six different vent systems (locations) were sampled during 2007 and 2008, and included water obtained directly from the hydrothermal vents as well as biomass and sediment associated with these high-temperature environments. Thorough geochemical analysis of these hydrothermal environments reveals variation in pH, sulfide, hydrogen and other potential electron donors that may drive primary productivity. The concentrations of dissolved hydrogen and sulfide were extremely high in numerous vents sampled, especially the deeper (30-50 m) vents located in the Inflated Plain, West Thumb, and Mary Bay. Significant dilution of hydrothermal fluids occurs due to mixing with surrounding lake water. Despite this, the temperatures observed in many of these hydrothermal vents range from 50-90 C, and elevated concentrations of constituents typically associated with geothermal activity in Yellowstone are observed in waters sampled directly from vent discharge. Microorganisms associated with elemental sulfur mats and filamentous ‘streamer’ communities of Inflated Plain and West Thumb (pH range 5-6) were dominated by members of the deeply-rooted bacterial Order Aquificales, but also contain thermophilic members of the domain Archaea. Assembly of metagenome sequence from the Inflated Plain vent biomass and to a lesser extent, West Thumb vent biomass reveal the importance of Sulfurihydrogenibium-like organisms, also important in numerous terrestrial geothermal

  4. Insights on the Biology of the Eastern Lau Spreading Center from Studies on the East Pacific Rise and Juan de Fuca Ridge (United States)

    Fisher, C. R.; Sen, A.; Becker, E.


    A primary goal of the Ridge 2000 program was to conduct comparable interdisciplinary studies at a few fundamentally different sites that would facilitate comparisons among sites and development of concepts with broad application across deep ocean ridge spreading centers. Although the Eastern Lau Spreading Center (ELSC) was the least known of the three Integrated Study Sites, we were able to make amazingly fast progress on understanding this system because we could draw on technology and experience developed during the RIDGE program to plan and conduct the work, and now interpret our findings in the context of the rich literature and Ridge 2000 studies on East Pacific Rise (EPR) , Juan de Fuca Ridge (JdFR), and Mid Atlantic Ridge communities. The ELSC communities not only house different species than those of the other regions, but unlike the often tubeworm dominated E. Pacific vents, they are structured by symbiont reliant species that are mobile; snails and mussels. Although there is some variation with lava type on the ELSC, the 4 species of large, symbiont-containing snails largely occupy the niches filled by tubeworms and mussels on the EPR, while the niche of the mussel in the W. Pacific vents is quite different from that of its EPR cousin. Although we have not observed any significant tectonic or magmatic events during our studies of the ELSC, 4 years of study considered in the context of what we have learned on the EPR and JdFR allow us to formulate and begin testing hypotheses about temporal change and succession in these very different and much less visited ecosystems. Furthermore, athough Paralvinella fijiensis are only found in limited areas on some chimneys and flanges, unlike the situation on the EPR and JdFR ,the ELSC chimney communities are largely composed of the same species as are found in diffuse flow on the lavas. The ELSC chimney communities are also remarkably stable, hosting some of the largest and apparently oldest individuals found on the

  5. Linking regional variation of epibiotic bacterial diversity and trophic ecology in a new species of Kiwaidae (Decapoda, Anomura) from East Scotia Ridge (Antarctica) hydrothermal vents. (United States)

    Zwirglmaier, Katrin; Reid, William D K; Heywood, Jane; Sweeting, Christopher J; Wigham, Benjamin D; Polunin, Nicholas V C; Hawkes, Jeff A; Connelly, Douglas P; Pearce, David; Linse, Katrin


    We analyzed the diversity of bacterial epibionts and trophic ecology of a new species of Kiwa yeti crab discovered at two hydrothermal vent fields (E2 and E9) on the East Scotia Ridge (ESR) in the Southern Ocean using a combination of 454 pyrosequencing, Sanger sequencing, and stable isotope analysis. The Kiwa epibiont communities were dominated by Epsilon- and Gammaproteobacteria. About 454 sequencing of the epibionts on 15 individual Kiwa specimen revealed large regional differences between the two hydrothermal vent fields: at E2, the bacterial community on the Kiwa ventral setae was dominated (up to 75%) by Gammaproteobacteria, whereas at E9 Epsilonproteobacteria dominated (up to 98%). Carbon stable isotope analysis of both Kiwa and the bacterial epibionts also showed distinct differences between E2 and E9 in mean and variability. Both stable isotope and sequence data suggest a dominance of different carbon fixation pathways of the epibiont communities at the two vent fields. At E2, epibionts were putatively fixing carbon via the Calvin-Benson-Bassham and reverse tricarboxylic acid cycle, while at E9 the reverse tricarboxylic acid cycle dominated. Co-varying epibiont diversity and isotope values at E2 and E9 also present further support for the hypothesis that epibionts serve as a food source for Kiwa. © 2014 The Authors. MicrobiologyOpen published by John Wiley & Sons Ltd.

  6. Impact of vent pipe diameter on characteristics of waste degradation in semi-aerobic bioreactor landfill. (United States)

    Jiang, Guobin; Liu, Dan; Chen, Weiming; Ye, Zhicheng; Liu, Hong; Li, Qibin


    The evolution mechanism of a vent pipe diameter on a waste-stabilization process in semi-aerobic bioreactor landfills was analyzed from the organic-matter concentration, biodegradability, spectral characteristics of dissolved organic matter, correlations and principal-component analysis. Waste samples were collected at different distances from the vent pipe and from different landfill layers in semi-aerobic bioreactor landfills with different vent pipe diameters. An increase in vent pipe diameter favored waste degradation. Waste degradation in landfills can be promoted slightly when the vent pipe diameter increases from 25 to 50 mm. It could be promoted significantly when the vent pipe diameter was increased to 75 mm. The vent pipe diameter is important in waste degradation in the middle layer of landfills. The dissolved organic matter in the waste is composed mainly of long-wave humus (humin), short-wave humus (fulvic acid) and tryptophan. The humification levels of the waste that was located at the center of vent pipes with 25-, 50- and 75-mm diameters were 2.2682, 4.0520 and 7.6419 Raman units, respectively. The appropriate vent pipe diameter for semi-aerobic bioreactor landfills with an 800-mm diameter was 75 mm. The effect of different vent pipe diameters on the degree of waste stabilization is reflected by two main components. Component 1 is related mainly to the content of fulvic acid, biologically degradable material and organic matter. Component 2 is related mainly to the content of tryptophan and humin from the higher vascular plants.

  7. Rapports de parenté et de production à San Juan, haute vallée du Chancay, Pérou

    Directory of Open Access Journals (Sweden)


    Full Text Available Les relations de parenté dans l'organisation des communautés andines sont particulièrement importantes, ce qui est aussi le cas à San Juan. L'utilisation et la distribution de l'eau en fonction de 'turnos' se font selon diverses combinaisons basées sur les relations de parenté. Il est vraisemblable que l'organisation des tours à l'intérieur du village et par quartiers se fasse également en fonction de la distribution des familles. L'élevage est aussi lié à ces relations de parenté, en particulier l'élaboration des fromages: les femmes ont ici une place prépondérante, tout comme pour l'irrigation. Ainsi les relations de parenté constituent un capital précieux, mais seulement dans le cas d'une société traditionnelle fonctionnant par prestations mutuelles. Or, on assiste actuellement à un développement du travail libre favorisé par les possibilités d'accumulation individuelle d'argent (vente de fruits, des produits de l'élevage. La division sexuelle du travail est envisagée en fin d'article. Las relaciones de parentesco en la organización de las comunidades andinas son particularmente importantes, lo cual también es el caso de San Juan. La utilización y distribución del agua, en función de 'turnos' se efectúa de acuerdo a diversas combinaciones basadas en las relaciones de parentesco. Es verosímil que la organización de turnos para el agua en el interior del pueblo y por barrios se efectúe igualmente en función de la distribución de las familias. La cría de ganado también estaba ligada a estas relaciones de parentesco, sobre todo la elaboración de quesos: en esto las mujeres tienen un lugar preponderante, así como para la irrigación. Así pues las relaciones de parentesco constituyen un capital precioso, pero tan solo en el caso de una sociedad tradicional que funcione por prestaciones mutuas. Ahora bien, actualmente se asiste a un desarrollo de trabajo libre favorecido por las posibilidades de acumulaci

  8. Vent d’Irlande sur lettres d’oc


    Forêt, Jean-Claude


    Vent d’Irlande sur lettres d’oc... Le titre ne tiendra guère ses promesses. On a vite fait le compte des auteurs occitans pour qui la littérature irlandaise du xxe siècle a vraiment compté. Personne ou presque, à part Max Rouquette. Denis Saurat, le poète cathare, inspiré par la littérature écossaise, Mac Diarmid en tête ? Peut-être a-t-il subi l’influence de Yeats, de sa fascination pour l’occultisme, ce qui reste à prouver... Antoine Dubernard, le dramaturge et paysan limousin ? L’influence...

  9. 40 CFR 63.1037 - Alternative means of emission limitation: Enclosed-vented process units or affected facilities. (United States)


    ... limitation: Enclosed-vented process units or affected facilities. 63.1037 Section 63.1037 Protection of...-vented process units or affected facilities. (a) Use of closed vent system and control device. Process units or affected facilities or portions of process units at affected facilities enclosed in such a...

  10. 40 CFR 63.7885 - What are the general standards I must meet for my affected process vents? (United States)


    ... meet for my affected process vents? 63.7885 Section 63.7885 Protection of Environment ENVIRONMENTAL... Remediation General Standards § 63.7885 What are the general standards I must meet for my affected process vents? (a) For the process vents that comprise the affected source designated under § 63.7882, you must...

  11. 40 CFR Table 4 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Metal HAP Process Vents (United States)


    ... Requirements for Metal HAP Process Vents 4 Table 4 to Subpart VVVVVV of Part 63 Protection of Environment... of Part 63—Emission Limits and Compliance Requirements for Metal HAP Process Vents As required in § 63.11496(f), you must comply with the requirements for metal HAP process vents as shown in the...

  12. Digital Geologic Map of San Juan Island National Historical Park and vicinity, Washington (NPS, GRD, GRE, SAJH, SAJH digital map) (United States)

    National Park Service, Department of the Interior — The Digital Geologic Map of San Juan Island National Historical Park and vicinity, Washington is composed of GIS data layers complete with ArcMap 9.2 layer (.LYR)...

  13. Hacia una poetica de las hagiografias novohispanas. El caso de la "vida" de Catarina de San Juan de Alonso Ramos

    National Research Council Canada - National Science Library

    Rice, Robin Ann


    .... Por medio del analisis de la hagiografia mas voluminosa escrita en el siglo XVII, la vida de Catarina de San Juan de Alonso Ramos, esta investigacion pretende formular una poetica hagiografica...

  14. EL CAMINO DEL INCA ENTRE TOCOTA Y VILLA NUEVA (VALLE DE IGLESIA, SAN JUAN / The Inka road between Tocota and Villa Nueva (Iglesia Valley, San Juan

    Directory of Open Access Journals (Sweden)

    Alejandro García


    Full Text Available La vialidad estatal incaica en los valles longitudinales de la provincia de San Juan, en el extremo SE del Tawantinsuyu, ha sido objeto de diversas consideraciones durante el último siglo. Sin embargo, no se han realizado estudios específicos destinados a comprobar su existencia, la cual incluso ha sido negada recientemente. A fin de aclarar el tema se realizó el relevamiento de un sector del Valle de Iglesia. En este artículo se presentan los resultados de ese estudio, junto con una revisión y discusión de los antecedentes y de algunas ideas vinculadas con el tema. Fundamentalmente, se verifica la presencia del Qhapaq Ñan en la parte baja del sector analizado, se refuta la propuesta de que el trazado longitudinal principal se habría extendido por la parte alta del sector precordillerano y se sostiene que el tramo relevado fue recorrido por Debenedetti a principios del siglo XX, aunque sin advertir que se trataba del camino incaico.   Palabras clave: Inca; Camino del Inca; Dominación incaica; Collasuyo; San Juan   Abstract The Inka road system in the longitudinal valleys of San Juan province, in the southeastern end of Tawantinsuyu, has been subject of several considerations during the last century. However, no specific studies have been undertaken to verify its existence, which recently has been even denied. To clarify the issue we surveyed a section of Iglesia Valley. This article presents the results of that study, along with a review and discussion of the background and of some ideas related to the topic. Basically, the presence of the Qhapaq Ñan at the bottom of the surveyed sector is verified, and the suggestion that the main inka longitudinal route would have extended over the top of the precordilleran mountain region is refused. Also, it is argued that the analyzed stretch was traveled by Debenedetti in the beginnings of the twentieth century, but without realizing that it was the Inka road.   Keywords: Inka; Inka Road; Inka

  15. Isolated communities of Epsilonproteobacteria in hydrothermal vent fluids of the Mariana Arc seamounts. (United States)

    Huber, Julie A; Cantin, Holly V; Huse, Susan M; Welch, David B Mark; Sogin, Mitchell L; Butterfield, David A


    Low-temperature hydrothermal vent fluids represent access points to diverse microbial communities living in oceanic crust. This study examined the distribution, relative abundance, and diversity of Epsilonproteobacteria in 14 low-temperature vent fluids from five volcanically active seamounts of the Mariana Arc using a 454 tag sequencing approach. Most vent fluids were enriched in cell concentrations compared with background seawater, and quantitative PCR results indicated that all fluids were dominated by bacteria. Operational taxonomic unit-based statistical tools applied to 454 data show that all vents from the northern end of the Mariana Arc grouped together, to the exclusion of southern arc seamounts, which were as distinct from one another as they were from northern seamounts. Statistical analysis also showed a significant relationship between seamount and individual vent groupings, suggesting that community membership may be linked to geographical isolation and not geochemical parameters. However, while there may be large-scale geographic differences, distance is not the distinguishing factor in the microbial community composition. At the local scale, most vents host a distinct population of Epsilonproteobacteria, regardless of seamount location. This suggests that there may be barriers to exchange and dispersal for these vent endemic microorganisms at hydrothermal seamounts of the Mariana Arc.

  16. In vivo and in vitro analysis of topographic changes secondary to DSAEK venting incisions

    Directory of Open Access Journals (Sweden)

    Church D


    Full Text Available Majid Moshirfar, Monette T Lependu, Dane Church, Marcus C Neuffer John A Moran Eye Center, University of Utah, Salt Lake City, UT, USA Introduction: Descemet’s stripping automated endothelial keratoplasty (DSAEK venting incisions may induce irregular corneal astigmatism. The study examines in vivo and in vitro astigmatic effects of venting incisions. Patients and methods: In vivo analysis examined eleven eyes of eleven patients who had received DSAEK with venting incisions. A chart review of the eleven eyes including assessment of pre and postoperative refraction and topography was performed. In vitro analysis examined three cadaver eyes which received topographic imaging followed by venting incisions at 4 mm, 6 mm, and 7 mm optical zones. Topographic imaging was then performed again after the incisions. Results: Postoperative topographies of eleven eyes demonstrated localized flattening at incision sites and cloverleaf pattern astigmatism. There was a significant difference in corneal irregularity measurement (P = 0.03, but no significant difference in shape factor or change of topographic cylinder. The cloverleaf pattern was found in cadaver eyes with incisions placed at 4 mm and 6 mm optical zones but not at the 7 mm zone. Conclusion: DSAEK venting incisions can cause irregular corneal astigmatism that may affect visual outcomes. The authors recommend placement of venting incisions near the 7 mm optical zone. Keywords: DSAEK, venting incisions, endothelial keratoplasty, astigmatism, endothelium, endothelial transplant

  17. Venting of gas explosion through relief ducts: interaction between internal and external explosions. (United States)

    Ferrara, G; Willacy, S K; Phylaktou, H N; Andrews, G E; Di Benedetto, A; Salzano, E; Russo, G


    Relief ducts fitted to venting openings is a widespread configuration in the industrial practice. The presence of a duct has been reported to severely increase the violence of the vented explosion posing a problem for the proper design of the venting device. Several studies have reported the leading importance--in the whole complex explosion phenomenology--of a secondary explosion in the duct. Modern approaches in the study of simply vented explosions (without ducts) have focused on the study of the interaction between internal and external explosion as a key issue in the mechanisms of pressure generation. The issue is even more relevant when a duct is fitted to the vent due the confined nature of the external explosion. In this work the interaction between internal and external events is experimentally investigated for gas explosions vented through a relief duct. The work has aimed at studying mechanisms underlying the pressure rise of this venting configuration. The study has put the emphasis on the mutual nature of the interaction. A larger scale than laboratory has been investigated allowing drawing results with a greater degree of generality with respect to data so far presented in literature.

  18. Periodic venting of MABR lumen allows high removal rates and high gas-transfer efficiencies. (United States)

    Perez-Calleja, P; Aybar, M; Picioreanu, C; Esteban-Garcia, A L; Martin, K J; Nerenberg, R


    The membrane-aerated biofilm reactor (MABR) is a novel treatment technology that employs gas-supplying membranes to deliver oxygen directly to a biofilm growing on the membrane surface. When operated with closed-end membranes, the MABR provides 100-percent oxygen transfer efficiencies (OTE), resulting in significant energy savings. However, closed-end MABRs are more sensitive to back-diffusion of inert gases, such as nitrogen. Back-diffusion reduces the average oxygen transfer rates (OTR), consequently decreasing the average contaminant removal fluxes (J). We hypothesized that venting the membrane lumen periodically would increase the OTR and J. Using an experimental flow cell and mathematical modeling, we showed that back-diffusion gas profiles developed over relatively long timescales. Thus, very short ventings could re-establish uniform gas profiles for relatively long time periods. Using modeling, we systematically explored the effect of the venting interval (time between ventings). At moderate venting intervals, opening the membrane for 20 s every 30 min, the venting significantly increased the average OTR and J without substantially impacting the OTEs. When the interval was short enough, in this case shorter than 20 min, the OTR was actually higher than for continuous open-end operation. Our results show that periodic venting is a promising strategy to combine the advantages of open-end and closed end operation, maximizing both the OTR and OTE. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Ventricular apical vents and postoperative focal contraction abnormalities in patients undergoing coronary artery bypass surgery. (United States)

    Shaw, R A; Kong, Y; Pritchett, E L; Warren, S G; Oldham, H N; Wagner, G S


    Ventriculograms made 9-15 months after surgery in 48 patients with normal preoperative apical contraction were reviewed to determine the influence of apical venting on apical wall motion in patients undergoing coronary bypass surgery. After interpretation of postoperative apical wall motion, the patients were subdivided into two groups. One group consisted of 34 patients who were vented by inserting a catheter through the apex of the left ventricle and the second group included 14 patients in whom no transventricular vent was made. The two groups were similar clinically and hemodynamically before surgery, and the surgical procedures were similar with the exception of vent site. Following surgery, incidences of graft patency and antegrade flow to the apex were also similar. Nineteen (56%) patients in the apically vented group had apical dyskinesia or akinesia observed on the postoperative ventriculogram while none of the patients who were not apically vented had these findings. None of the patients with apical dyskinesia or akinesia had congestive heart failure following surgery. The postoperative ventriculograms of 12 patients with mitral stenosis who underwent valvulotomy by inserting a Tubbs dilator through the apex were also analyzed. Only one patient (8.5%) had apical dyskinesia or akinesia. Since the patients with mitral stenosis probably did not have significant coronary artery disease, it is possible that the combination of the apical vent and ischemic heart disease was responsible for the focal contraction abnormalities observed.

  20. The Hydrothermal Vent Biosampler (HVB) Developed to Collect `Pristine' Samples (Iceland & Myojin Knoll & Planned deployment on the Myojin Knoll & Suiyo Seamount. (United States)

    Behar, A.; Bruckner, J.; Venkateswaran, K.; Matthews, J.


    Marine hydrothermal systems and the unique biota associated with them represent some of the most interesting ecosystems on the planet. These `extreme' environments are often composed of vents spewing super-heated fluid containing a variety of minerals and reduced compounds, numerous of which can be used as substrates for growth by microorganisms. To accurately describe the diversity and distribution of these chemosynthetic communities, it is essential to collect samples from defined locations associated with a given hydrothermal vent without contamination from the surrounding water column (e.g. the collected samples are `pristine'). Additionally, samples need to be collected in sufficient volume to a) account for the potential low biomass of these environments and b) provide modern molecular techniques with adequate sample material. The hydrothermal vent biosampler (HVB) was developed to collect `pristine' hydrothermal vent samples for microbial analyses. Utilizing an array of sensors (temperature monitors and flow meters), the system can relay real time data regarding sampling conditions allowing accurate placement of the HVB's collection nozzle and ensuring samples are collected from defined locations. The unit has been designed to withstand extreme conditions (source water temperatures >400°C) and has been pressure tested to a simulated depth of 6.5km and undergone field trials along the Eyjafjordur Fjord hydrothermal system (Iceland). Collection of sufficient biomass is achieved through employment of a series of filters (90, 60, 7 and 0.2 ìm pore sizes) that concentrate ~20L of hydrothermal fluid to a final volume of 500-ml. Filtered samples can be directly collected from the HVB for subsequent biological analyses (both culture- and molecular-based). In conjunction with JAMSTEC, further field exercises along the Myojin Knoll and Suiyo Seamount have been planned for November 2006.

  1. The Harmony of Becoming: Zen and Poetry in the Work of Juan L. Ortiz

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    Tania Favela Bustillo


    Full Text Available I am exploring in this essay the relation in Argentinian poet Juan L. Ortiz’s poetry,between the poetic experience and the zen philosophy of enlightenment orsatori. Through the contemplation of the landscape in his everyday fatherland,Juan L. Ortiz reaches consciousness in which he perceives the wonder of onebeing one with everything. Renouncement of one’s self, attention to the smallestof things, acceptance of the void as basis of our existence, take him to seelove as the only answer to recover harmony.Ortiz’s poetry gives then the possibility to enter, through language, to thatharmony he so aspires. An important axis in this essay is to present how Ortiz’slanguage succeeds to configure within itself that experience, how he builds up a language which he himself denominated “transparent”, and how this languagecontains within itself the harmony of becoming.

  2. Juan Valdez la estrategia detrás de la marca

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    Ana María Parente


    Full Text Available El libro Juan Valdez, la estrategia detrás de la marca busca explicar la táctica de valorización del café colombiano desarrollada por la Federación Nacional de Cafeteros (FNC, que tiene como principal objetivo beneficiar a los caficultores colombianos a lo largo de la cadena de valor. Para ello, el texto hace un recuento del contexto del mercado cafetero mundial, haciendo énfasis en los principales proveedores y consumidores hasta finalmente centrarse en la construcción de la marca Café de Colombia® y Juan Valdez® como estrategias para darle competitividad al grano colombiano.

  3. Axial seamount: An active ridge axis volcano on the Central Juan De Fuca Ridge (United States)

    Johnson, H. Paul; Embley, Robert W.


    Axial Seamount (some of the manuscripts in this special section refer to the edifice with the more precise name of "Axial Volcano"), a large ridge axis volcano, is located on the central segment of the Juan de Fuca Ridge approximately 250 nautical miles west of the Washington/Oregon/British Columbia coast. Currently both volcanically and hydrothermally active, Axial lies directly at the intersection of the Cobb-Eickelberg Seamount Chain and the Juan de Fuca Ridge (Figure 1). The volcanic activity associated with the seamount formation strongly interacts with, and is affected by, the normal seafloor spreading processes at the intersection. Because of this unique geologic setting, its proximity to west coast ports and oceanographie institutions, and its shallow depth, Axial has become the focus of a large number of scientific investigations over the past decade.

  4. Juan Puma, el hijo del oso. Cuento quechua de La Jalca, Chachapoyas

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    Full Text Available JUAN PUMA, LE FILS DE L'OURS . CONTE QUECHUA DE LA JALCA, CHACHAPOYAS. Une des fêtes les plus importantes de la communauté de La Jalca, Province de Chachapoyas, Amazonas, est celle de la Saint-Pierre où l’on exécute une danse de l’ours très semblable à celle des ukukus du sud péruvien. Le narrateur du récit que nous publions ici assimile ce rite à l’histoire de Juan Oso (Jean de l’Ours très connue dans le monde andin. L’importance de l’ours dans cette culture des hautes terres amazoniennes est fondamentale. En quechua local, l’ours s’appelle “puma” et partage avec le puma de la forêt les caractéristiques de puissance effrayante et de pouvoirs surnaturels. Le fils de l’ours, Juan, évoque les relations ambiguës liant les “chrétiens” des hautes terres d’Amazonas et les “sauvages” de la forêt. Una de las fiestas más importantes de la comunidad de La Jalca, Provincia de Chachapoyas, Amazonas, es la de San Pedro en la que se representa un baile del oso muy semejante al baile de los ukukus del sur peruano. El narrador del cuento que publicamos aquí asimila este rito a la historia de Juan Oso, muy conocido en el mundo andino. La importancia del oso en esta cultura de la ceja de selva alta es fundamental. En quechua local, el oso se llama “puma” y comparte con el puma de la selva las características de fuerza temible y poderes sobrenaturales. El hijo del oso, Juan, evoca las relaciones ambiguas existentes entre los “cristianos” de la serranía de Amazonas y los “chunchos” de la selva. JUAN PUMA, THE BEAR'S SON. A QUECHUA TALE FROM LA JALCA, CHACHAPOYAS. One of the most important feasts of the community of La Jalca, Province of Amazonas, is that of Saint Peter in which a bear dance similar to the southern Peruvian dance of the ukukus is performed. In the story published here, the narrator assimilates this rite with the tale of Juan Oso, another story which is well known throughout the Andes. The importance of bears

  5. Effect of pressure vents on the fast cookoff of energetic materials.

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, Marcia A.; Oliver, Michael S.; Erikson, William W


    The effect of vents on the fast cookoff of energetic materials is studied through experimental modifications to the confinement vessel of the Radiant Heat Fast Cookoff Apparatus. Two venting schemes were investigated: 1) machined grooves at the EM-cover plate interface; 2) radial distribution of holes in PEEK confiner. EM materials of PBXN-109 and PBX 9502 were tested. Challenges with the experimental apparatus and EM materials were identified such that studying the effect of vents as an independent parameter was not realized. The experimental methods, data and post-test observations are presented and discussed.

  6. A new species of Ophryotrocha (Annelida, Eunicida, Dorvilleidae from hydrothermal vents on the Southwest Indian Ridge

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    Dong-sheng Zhang


    Full Text Available Dorvilleids were collected from hydrothermal vents on the Southwest Indian Ridge by manned submersible Jiaolong. These represent a new species of Ophryotrocha that is here described as Ophryotrocha jiaolongi sp. n. This is the first dorvilleid described from vents on the Southwest Indian Ridge. It most closely resembles another vent species, Ophryotrocha akessoni Blake, 1985 from the Galapagos Rift, but can be distinguished by its antennae, palps, jaw structure. The new species has particularly distinctive mandibles, which allow it to be easily identified.

  7. Anatomical studies of Baccharis grisebachii Hieron. (Asteraceae). Used in folk medicine of San Juan province, Argentina


    Hadad, Martín Ariel; Gattuso, Susana Julia; Gattuso, Martha Ana; Feresin, Gabriela Egly; Tapia, Aníbal Alejandro


    Baccharis grisebachii Hieron., commonly known as “quilchamali”, is a bushy plant that lives in the high mountains of Argentina and southern Bolivia. The infusion or decoction of aerial parts is used in the traditional medicine of San Juan province, Argentina, to treat gastric ulcers, digestive problems, and as antiseptic and wound healing in humans and horses. The aim of this study is to analyze the anatomical characters of B. grisebachii for specific identification and quality control. The r...

  8. The paradigm of paraglacial megafans of the San Juan river basin, Central Andes, Argentina (United States)

    Suvires, Graciela M.


    The spatial distribution and several morphometric characteristics of the Quaternary alluvial fans of the San Juan River, in the province of San Juan, at the Central and Western part of Argentina, have been studied to classify them as paraglacial megafans, as well to ratify its depositional environmental conditions. The high sedimentary load exported by San Juan river from the Central Andes to the foreland depressions is estimated about 3,682,200 hm3. The large alluvial fans of Ullum-Zonda and Tulum valleys were deposited into deep tectonic depressions, during the Upper Pleistocene deglaciation stages. The outcome of collecting remotely sensed data, map and DEM data, geophysical data and much fieldwork gave access to morphometric, morphographic and morphogenetic data of these alluvial fans. The main drainage network was mapped on processed images using QGis (vers.2.0.1). Several fan morphometric parameters were measured, such as the size, the shape, the thickness, the surface areas and the sedimentary volume of exported load. The analyzed fans were accumulated in deep tectonic depressions, where the alluvium fill reaches 700 to 1200 m thick. Such fans do not reach the large size that other world megafans have, and this is due to tectonic obstacles, although the sedimentary fill average volume surpasses 514,000 hm3. The author proposes to consider Ullum-Zonda and Tulum alluvial fans as paraglacial megafans. According to the stratigraphic relationships of the tropical South American Rivers, the author considers that the San Juan paraglacial megafans would have occurred in the period before 24 ka BP , possibly corresponding to Middle Pleniglacial (ca 65-24ka BP). They record colder and more humid conditions compared with the present arid and dry conditions.

  9. Tradición y modernidad: la Virgen de San Juan de los Lagos

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    Anna M. Fernández Poncela


    Full Text Available El texto muestra los aspectos modernos y tradicionales de la Virgen de San Juan de los Lagos, imagen y santuario religioso popular en el estado de Jalisco, México. Es una devoción con origen tradicional que va en aumento, que aglutina la identidad regional, la religión y el comercio, y se expande entre los migrantes a Estados Unidos.

  10. Family, gold and power: The plots of kinship. San Juan (1790-1815.

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    Eliana Beatriz Fracapani Ríos


    Full Text Available The purpose of this paper is to present the families dedicated to the mining activity and explain how family networks were woven, in order to interpret the power structure, the accumulation of capital, and the form in which production relations were articulated, at the end of the colonial period, in the territory of the current province of San Juan. In order to do this, irst-hand sources such as scribe protocols, testaments and judicial records are used.

  11. Juan García de Miranda : pinturas religiosas en conjuntos madrileños (II

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    María Teresa Jiménez Priego


    Full Text Available Juan de Miranda, en sus prolongados contactos en Madrid y Alcalá de Henares con la orden franciscana, se familiarizó con los temas favoritos de la Orden y su época: la vida de los santos más insignes (San Diego, San Pascual Bailón.... Fruto de esta influencia parecen ser dos cuadros sobre la vida de San Pascual Bailón que habitualmente se le han atribuido.

  12. Turismo rural y comunalidad: impactos socioterritoriales en San Juan Atzingo, México


    Pérez-Ramírez, Carlos Alberto; Universidad Autónoma del Estado de México; Zizumbo-Villareal, Lilia; Universidad Autónoma del Estado de México


    El desarrollo del turismo rural en San Juan Atzingo, estado de México, ha sido impulsado por parte de diversos organismos internacionales, dependencias del Gobierno Federal, empresas del sector privado e incluso algunas organizaciones de la sociedad civil. No obstante, la actividad no se ha consolidado y está generando resultados contradictorios sobre los componentes que determinan el modo de vida y producción campesina. El trabajo identifica los impactos socioterritoriales del proyecto Ecotu...

  13. Reflections on Don Juan and on the utility of the unhappy love affair. (United States)

    Bergel, Ernest


    Based on an unusual clinical experience of a teenage boy in child psychotherapy, two conclusions are proposed: (1) that the extremely unhappy, early love affairs that occur in most men's lives serve a valuable function in helping them separate from their mothers sufficiently to be able to realistically relate to appropriate marriage partners, and (2) that some Don Juans start new relationships in order to break them off, rather than the reverse.

  14. Visit of His Excellency Mr Juan Martabit, Ambassador, Permanent Representative of Chile to the United Nations Office in Geneva and other international organisations in Switzerland.

    CERN Multimedia

    Maximilien Brice


    Secretary-General; Mrs Juan Martabit. 0502017_07.jpg His Excellency Mr Juan Martabit, Ambassador,Permanent Representative of Chile to the United Nations Office in Geneva and other international organisations in Switzerland visiting the ATLAS building site. From left to right: Prof. Giora Mikenberg, ATLAS Collaboration; Mr Maximilian Metzger, Secretary-General and His Excellency Mr Juan Martabit. 0502017_08.jpg His Excellency Mr Juan Martabit, Ambassador,Permanent Representative of Chile to the United Nations Office in Geneva and other international organisations in Switzerland visiting the ATLAS cavern. From left to right: From left to right: Prof. Giora Mikenberg, ATLAS Collaboration; Mr Maximilian Metzger, Secretary-General; His Excellency Mr Juan Martabit and Mrs Juan Martabit.

  15. A propósito de unas versiones de La Sagrada Familia con los santos «Juanitos» de Juan de Juanes

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    Mateo Gómez, Isabel


    Full Text Available Desde el año 1961 consta en el Archivo fotográfico del Instituto Amatller de Barcelona una Sagrada Familia con los santos «Juanitos» (fig. 1, en colección privada madrileña. Un año después, José Luis Alonso Misol la publicó en un artículo sobre Pintura española en colecciones madrileñas, aportando el nombre del coleccionista, Sr. Fernández López, y destacando que se trataba de una de las mejores obras de Juan de Juanes, de la que hay otras versiones con algunas variantes, poniendo como ejemplo de ellas la de la Academia de San Fernando (fig. 3. En esta línea podría considerarse la pintada por Nicolás Borras (fig. 4, de la colección Grases de Barcelona donde se encontraba en 1916, y en la que se advierten ambas influencias.…

  16. Juan Gonzalo Restrepo Londoño. Semblanzas de un empresario Juan Gonzalo Restrepo Londoño. Semblanzas de un empresario

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    Jairo Andrés Campuzano Hoyos


    Full Text Available Es este un breve recorrido por la vida de Juan Gonzalo Restrepo Londoño,quien además de tener la fortuna de crecer en el seno de una familia tradicionalantioqueña, fue haciéndose portador de invaluables conocimientos que lepermitirían engranarse exitosamente en la maquinaria empresarial colombianadurante la segunda mitad del siglo xx. La institución de la familia, el conocimientodel entorno natural y social, y una marcada propensión al servicio de los interesesregionales, serán, entre otros, los elementos que caractericen y hagan comprensiblelas ejecutorias de este empresario multifacético e innovador.This is a brief journey through the life of Juan Gonzalo Restrepo Londoño. Besides having the fortune of growing up within the heart of a traditional family of Antioquia, he became bearer of invaluable knowledge since his youth, which allowed him to engage successfully in the entrepreneurial machinery of the region during the second half of the XXth century.The institution of the family, the knowledge of the natural and social context and a marked tendency to serve the interests of a region would be, among others, the elements to characterize and make intelligible the actions of this versatile and innovative businessman.

  17. Linking hydrothermal geochemistry to organismal physiology: physiological versatility in Riftia pachyptila from sedimented and basalt-hosted vents.

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    Julie C Robidart

    Full Text Available Much of what is known regarding Riftia pachyptila physiology is based on the wealth of studies of tubeworms living at diffuse flows along the fast-spreading, basalt-hosted East Pacific Rise (EPR. These studies have collectively suggested that Riftia pachyptila and its chemoautotrophic symbionts are physiologically specialized, highly productive associations relying on hydrogen sulfide and oxygen to generate energy for carbon fixation, and the symbiont's nitrate reduction to ammonia for energy and biosynthesis. However, Riftia also flourish in sediment-hosted vents, which are markedly different in geochemistry than basalt-hosted systems. Here we present data from shipboard physiological studies and global quantitative proteomic analyses of Riftia pachyptila trophosome tissue recovered from tubeworms residing in the EPR and the Guaymas basin, a sedimented, hydrothermal vent field. We observed marked differences in symbiont nitrogen metabolism in both the respirometric and proteomic data. The proteomic data further suggest that Riftia associations in Guaymas may utilize different sulfur compounds for energy generation, may have an increased capacity for energy storage, and may play a role in degrading exogenous organic carbon. Together these data reveal that Riftia symbionts are far more physiologically plastic than previously considered, and that--contrary to previous assertions--Riftia do assimilate reduced nitrogen in some habitats. These observations raise new hypotheses regarding adaptations to the geochemical diversity of habitats occupied by Riftia, and the degree to which the environment influences symbiont physiology and evolution.

  18. Hinduism in Animal de fondo by Juan Ramón Jimenez

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    Christine Steffen


    Full Text Available Animal de fondo (1949, by Juan Ramón Jimenez, is an enigmatic and joyous recounting of a mystical trance which the poet experienced during a sea voyage from New York to Buenos Aires in 1948. This essay approaches the poems from the perspective of classic Hindu religious traditions. The conciencia frequently used by Juan Ramón to express integration with the natural world is analogous to Brahman, the all-pervading reality which for the Vedic poets includes everything from the life of man to sticks and stones. The apparent polytheism of Animal de fondo echoes Vedic hymns, which deify many important social and natural elements. The Hindu concept of dharma , the sacred law of society regulating moral order, duties, and forms of conduct appropriate for different classes or persons, appears in poems where the poet exults in his poetizing function. Juan Ramón assimilated elements of the relativist-pluralist Hindu tradition that relegated questions of dogma to secondary importance, and, like the Vedic hymn-makers, was able to capture religious reality that was reflected in his own heart and mind and affirm it joyously.

  19. Assessing Climate Variability Effects on Dengue Incidence in San Juan, Puerto Rico

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    Pablo Méndez-Lázaro


    Full Text Available We test the hypothesis that climate and environmental conditions are becoming favorable for dengue transmission in San Juan, Puerto Rico. Sea Level Pressure (SLP, Mean Sea Level (MSL, Wind, Sea Surface Temperature (SST, Air Surface Temperature (AST, Rainfall, and confirmed dengue cases were analyzed. We evaluated the dengue incidence and environmental data with Principal Component Analysis, Pearson correlation coefficient, Mann-Kendall trend test and logistic regressions. Results indicated that dry days are increasing and wet days are decreasing. MSL is increasing, posing higher risk of dengue as the perimeter of the San Juan Bay estuary expands and shorelines move inland. Warming is evident with both SST and AST. Maximum and minimum air surface temperature extremes have increased. Between 1992 and 2011, dengue transmission increased by a factor of 3.4 (95% CI: 1.9–6.1 for each 1 °C increase in SST. For the period 2007–2011 alone, dengue incidence reached a factor of 5.2 (95% CI: 1.9–13.9 for each 1 °C increase in SST. Teenagers are consistently the age group that suffers the most infections in San Juan. Results help understand possible impacts of different climate change scenarios in planning for social adaptation and public health interventions.

  20. Assessing Climate Variability Effects on Dengue Incidence in San Juan, Puerto Rico (United States)

    Méndez-Lázaro, Pablo; Muller-Karger, Frank E.; Otis, Daniel; McCarthy, Matthew J.; Peña-Orellana, Marisol


    We test the hypothesis that climate and environmental conditions are becoming favorable for dengue transmission in San Juan, Puerto Rico. Sea Level Pressure (SLP), Mean Sea Level (MSL), Wind, Sea Surface Temperature (SST), Air Surface Temperature (AST), Rainfall, and confirmed dengue cases were analyzed. We evaluated the dengue incidence and environmental data with Principal Component Analysis, Pearson correlation coefficient, Mann-Kendall trend test and logistic regressions. Results indicated that dry days are increasing and wet days are decreasing. MSL is increasing, posing higher risk of dengue as the perimeter of the San Juan Bay estuary expands and shorelines move inland. Warming is evident with both SST and AST. Maximum and minimum air surface temperature extremes have increased. Between 1992 and 2011, dengue transmission increased by a factor of 3.4 (95% CI: 1.9–6.1) for each 1 °C increase in SST. For the period 2007–2011 alone, dengue incidence reached a factor of 5.2 (95% CI: 1.9–13.9) for each 1 °C increase in SST. Teenagers are consistently the age group that suffers the most infections in San Juan. Results help understand possible impacts of different climate change scenarios in planning for social adaptation and public health interventions. PMID:25216253

  1. Dry Juan de Fuca slab revealed by quantification of water entering Cascadia subduction zone (United States)

    Canales, J. P.; Carbotte, S. M.; Nedimović, M. R.; Carton, H.


    Water is carried by subducting slabs as a pore fluid and in structurally bound minerals, yet no comprehensive quantification of water content and how it is stored and distributed at depth within incoming plates exists for any segment of the global subduction system. Here we use seismic data to quantify the amount of pore and structurally bound water in the Juan de Fuca plate entering the Cascadia subduction zone. Specifically, we analyse these water reservoirs in the sediments, crust and lithospheric mantle, and their variations along the central Cascadia margin. We find that the Juan de Fuca lower crust and mantle are drier than at any other subducting plate, with most of the water stored in the sediments and upper crust. Variable but limited bend faulting along the margin limits slab access to water, and a warm thermal structure resulting from a thick sediment cover and young plate age prevents significant serpentinization of the mantle. The dryness of the lower crust and mantle indicates that fluids that facilitate episodic tremor and slip must be sourced from the subducted upper crust, and that decompression rather than hydrous melting must dominate arc magmatism in central Cascadia. Additionally, dry subducted lower crust and mantle can explain the low levels of intermediate-depth seismicity in the Juan de Fuca slab.

  2. Navegación costarricense por el río San Juan

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    Ricardo Wheelock Román


    Full Text Available El Estado de Nicaragua afirma que el Laudo Cleveland zanjó todas las cuestiones relativas a los límites fronterizos terrestres con Costa Rica, a la vez que no se reconoce la sentencia de la CJC de 1916 ya que se extralimitó en sus funciones. Por el Tratado Jerez-Cañas, Costa Rica sólo puede servirse del Río San Juan para "objetos de comercio" y entrando por San Juan del Norte, para que lleguen al interior de Costa Rica, el Tratado no especifica la viceversa, por lo que no puede ser usado para fines turísticos, vía de navegación o de abastecimiento 0 que el derecho de navegar "con objetos de comercio" se pueda , como extensión de soberanía y jurisdicción costarricense a los buques y personas de ese país que navegan por el Río San Juan, 10 que resultaría en negación de la soberanía de Nicaragua

  3. The San Juan Canyon, southeastern Utah: A geographic and hydrographic reconnaissance (United States)

    Miser, Hugh D.


    This report, which describes the San Juan Canyon, San Juan River and the tributary streams and the geography and to some extent the geology of the region, presents information obtained by me during the descent of the river with the Trimble party in 1921. The exploration of the canyon, which was financed jointly by the United States Geological Survey and the Southern California Edison Co., had as its primary object the mapping and study of the San Juan in connection with proposed power and storage projects along this and Colorado rivers.1 The exploration party was headed by K. W. Thimble, topographic engineer of the United States Geological Survey. Other members of the party were Robert N. Allen, Los Angeles, Calif., recorder; H. E. Blake, jr., Monticello, Utah, and Hugh Hyde, Salt Lake City, Utah, rodmen; Bert Loper, Green River, Utah, boatman; Heber Christensen, Moab, Utah, cook; and H. D. Miser, geologist. Wesley Oliver, of Mexican Hat, Utah, served as packer for the party and brought mail and provisions by pack train twice a month to specified accessible places west of Goodridge.

  4. Juan de Fuca slab geometry and its relation to Wadati-Benioff zone seismicity (United States)

    McCrory, Patricia A.; Blair, J. Luke; Waldhause, Felix; Oppenheimer, David H.


    A new model of the subducted Juan de Fuca plate beneath western North America allows first-order correlations between the occurrence of Wadati-Benioff zone earthquakes and slab geometry, temperature, and hydration state. The geo-referenced 3D model, constructed from weighted control points, integrates depth information from earthquake locations and regional seismic velocity studies. We use the model to separate earthquakes that occur in the Cascadia forearc from those that occur within the underlying Juan de Fuca plate and thereby reveal previously obscured details regarding the spatial distribution of earthquakes. Seismicity within the slab is most prevalent where the slab is warped beneath northwestern California and western Washington suggesting that slab flexure, in addition to expected metamorphic dehydration processes, promotes earthquake occurrence within the subducted oceanic plate. Earthquake patterns beneath western Vancouver Island are consistent with slab dehydration processes. Conversely, the lack of slab earthquakes beneath western Oregon is consistent with an anhydrous slab. Double-differenced relocated seismicity resolves a double seismic zone within the slab beneath northwestern California that strongly constrains the location of the plate interface and delineates a cluster of seismicity 10 km above the surface that includes the 1992 M7.1 Mendocino earthquake. We infer that this earthquake ruptured a surface within the Cascadia accretionary margin above the Juan de Fuca plate. We further speculate that this earthquake is associated with a detached fragment of former Farallon plate. Other subsurface tectonic elements within the forearc may have the potential to generate similar damaging earthquakes.

  5. Development of a new deep-sea hybrid Raman insertion probe and its application to the geochemistry of hydrothermal vent and cold seep fluids (United States)

    Zhang, Xin; Du, Zengfeng; Zheng, Ronger; Luan, Zhendong; Qi, Fujun; Cheng, Kai; Wang, Bing; Ye, Wangquan; Liu, Xiaorui; Lian, Chao; Chen, Changan; Guo, Jinjia; Li, Ying; Yan, Jun


    Hydrothermal vent fluids, cold seep fluids, their associated chemosynthetic communities, and the biogeochemical anaerobic oxidation of methane (AOM) play very important roles in the biogeochemical sulfur and carbon cycles in the ocean. Based on our previous success developing and deploying a deep-sea sediment pore water Raman probe, we developed a new deep-sea hybrid Raman insertion probe (RiP) designed to operate at temperatures up to 450 °C that can be inserted directly into high-temperature fluids emerging from hydrothermal vents. By routinely exchanging the various tips and optics of the probe, we can analyze the geochemistry of hydrothermal vent fluids, cold seep fluids, and sediment pore water profiles (0-60 cm) in situ. The instrument ensemble also includes a new deep-sea laser Raman spectrometer in a custom-designed, 6000-m titanium pressure housing, which is powered, controlled and deployed by the remotely operated vehicle (ROV) Faxian down to a maximum water depth of 4500 m. The new RiP was deployed at the Izena Hole hydrothermal area in the middle Okinawa Trough back-arc basin; the Papua-Australia-Canada-Manus (PACManus) hydrothermal vent area in the Manus back-arc basin, Papua New Guinea; and a cold seep field at Formosa Ridge in the northern South China Sea. The Raman peaks of CO2, CH4, H2S, HS-, SO42- and S8 were obtained in situ from high-temperature hydrothermal vents (290 °C), low-temperature cold seep fluids (2 °C) and the surrounding sediment pore water. Dissolved CH4 and S8 were identified for the first time in the fluids under the lush chemosynthetic communities of the cold seep. Several sediment pore water profiles collected near the cold seep were characterized by the loss of SO42- and increased CH4, H2S and HS- peaks. Additionally, the in situ pH range of the pore water profile was between 6.95 and 7.22. Thus, the RiP system provides a very useful tool for investigating the geochemistry of hydrothermal vent and cold seep fluids.

  6. A fossil venting system in the Feragen Ultramafic Body, Norway? (United States)

    Dunkel, Kristina G.; Jamtveit, Bjørn; Austrheim, Håkon


    Carbonation of ultramafic rocks in ophiolites and on the seafloor has recently been the focus of extensive research, as this alteration reaction not only influences the carbon flux between hydro- and lithosphere, but also provides natural analogues for industrial CO2 sequestration. It is a significant part of the hydrothermal circulation in the oceanic crust, as demonstrated by carbonate precipitation at hydrothermal vents. We provide microstructural and geochemical data from a previously little known ophicarbonate occurrence in the Feragen Ultramafic Body, Sør-Trøndelag, Norway. Along the northern edge of the Feragen Ultramafic Body, strongly serpentinised peridotites are carbonated. In places, the carbonation took place pervasively, leading to the formation of soapstones consisting mainly of talc and magnesite. More common is the carbonation of serpentinite breccias. Within the clasts, some of the serpentine mesh centres are replaced by magnesite, and, subordinately, dolomite or calcium carbonate. Four types of matrix have been identified in different localities: fine-grained magnesite, coarse-grained calcium carbonate, brucite occurring in large fans (up to 1 mm in diameter), and dolomite. Inclusion trails in the coarse-grained calcium carbonates record botryoidal growth, indicating crystallisation from a fluid in open space, and a hexagonal precursor phase, suggesting that aragonite was replaced by calcite. Brucite-cemented serpentinite breccias occur very locally in two outcrops with a size less than 10 m2. Many of the brucite fans have a similar arrangement of inclusions, with an area rich in dolomite inclusions in the centre of the brucite crystals, and magnetite inclusions concentrated in the tips. Dolomite as a matrix phase often grows inwards from hexagonal, rectangular, rhomboidal, or irregular pores. Many dolomite grains are probably cast pseudomorphs after (calcitised) aragonite. Some carbonate crystals are crosscut or replaced by serpentine. The

  7. Analysis of TLM Air-vent Model Applicability to EMC Problems for Normal Incident Plane Wave

    Directory of Open Access Journals (Sweden)

    N. J. Nešić


    Full Text Available In this paper, the shielding properties related to a protective metal enclosure with airflow aperture arrays are numerically analyzed. As a numerical model, a TLM method, either in a conventional form based on fine mesh to describe apertures presence or enhanced with the compact air-vent model is employed. The main focus in the paper is on examining the limits of applying the compact air-vent model for EMC problems solving. Namely, various values for the distance between neighboring apertures in the TLM air-vent models as well as the air-vent thicknesses are analyzed. Specifically, the analyses are conducted for a normal incident plane wave, vertically and horizontally polarized.

  8. Stochastic Mapping for Chemical Plume Source Localization With Application to Autonomous Hydrothermal Vent Discovery

    National Research Council Canada - National Science Library

    Jakuba, Michael V


    ..., explosive ordinance removal, and hydrothermal vent prospecting. Turbulent flows make the spatial relationship between the detectable manifestation of a chemical plume source, the plume itself, and the location of its source inherently uncertain...

  9. Reactor pressure vessel head vents and methods of using the same (United States)

    Gels, John L; Keck, David J; Deaver, Gerald A


    Internal head vents are usable in nuclear reactors and include piping inside of the reactor pressure vessel with a vent in the reactor upper head. Piping extends downward from the upper head and passes outside of the reactor to permit the gas to escape or be forcibly vented outside of the reactor without external piping on the upper head. The piping may include upper and lowers section that removably mate where the upper head joins to the reactor pressure vessel. The removable mating may include a compressible bellows and corresponding funnel. The piping is fabricated of nuclear-reactor-safe materials, including carbon steel, stainless steel, and/or a Ni--Cr--Fe alloy. Methods install an internal head vent in a nuclear reactor by securing piping to an internal surface of an upper head of the nuclear reactor and/or securing piping to an internal surface of a reactor pressure vessel.

  10. AT26-10 Chemosynthetic Microbial Communities at Deep-Sea Vents (EM122) (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The cruise will include 16 dives with DSV Alvin or ROV Jason, to allow time for deployment and collection of experiments and for extensive sampling of discrete vents...

  11. Ultrafine particles from a vented gas clothes dryer (United States)

    Wallace, Lance

    Ultrafine particles (˜10-100 nm) were measured continuously for 18 months in an occupied townhouse. A major source was determined to be the gas clothes dryer. Although the dryer was vented to the outdoors it consistently produced an order of magnitude increase in the ultrafine concentrations compared to times with no indoor sources. Short-term peak number concentrations exceeded 100,000 cm -3 on a number of occasions. The source strength was conservatively estimated at about 6×10 12 ultrafine particles produced per drying episode. These values are underestimates, since the part of the peak below 9.8 nm was not measured. Averaged over 150 h of operation, the number concentration showed a major peak at the smallest size measured (9.8 nm) and a secondary peak at 30 nm. Loss rates of the ultrafines due to diffusion, deposition, and particle growth (1-2 h -1) were high compared to losses due to air exchange (0.1-0.6 h -1). Considering the reported health effects of ultrafines, the widespread use of gas dryers, and the substantial amount of time that gas dryers are operated in many homes, it may be desirable to carry out further research to determine if the results reported here for a single dryer in one home are reproducible under different conditions.

  12. DIII-D Dust Particulate Characterization (June 1998 Vent)

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, William Jonathan


    Dust is a key component of fusion power device accident source term. Understanding the amount of dust expected in fusion power devices and its physical and chemical characteristics is needed to verify assumptions currently used in safety analyses. An important part of this safety research and development work is to characterize dust from existing experimental tokamaks. In this report, we present the collection, data analysis methods used, and the characterization of dust particulate collected from various locations inside the General Atomics DIII-D vacuum vessel following the June 1998 vent. The collected particulate was analyzed at the Idaho National Engineering and Environmental Laboratory (INEEL). Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Choice of collection technique is important because the sampling method used can bias the particle size distribution collected. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Seventeen samples were collected including plasma facing surfaces in lower, upper, and horizontal locations, surfaces behind floor tiles, surfaces behind divertor tiles, and surfaces behind ceiling tiles. The results of the analysis are presented.

  13. DIII-D dust particulate characterization (June 1998 Vent)

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, W.J.


    Dust is a key component of fusion power device accident source term. Understanding the amount of dust expected in fusion power devices and its physical and chemical characteristics is needed to verify assumptions currently used in safety analyses. An important part of this safety research and development work is to characterize dust from existing experimental tokamaks. In this report, the authors present the collection, data analysis methods used, and the characterization of dust particulate collected from various locations inside the General Atomics DIII-D vacuum vessel following the June 1998 vent. The collected particulate was analyzed at the Idaho National Engineering and Environmental Laboratory (INEEL). Two methods were used to collect particulate with the goal of preserving the particle size distribution and physical characteristics of the particulate. Choice of collection technique is important because the sampling method used can bias the particle size distribution collected. Vacuum collection on substrates and adhesion removal with metallurgical replicating tape were chosen as non-intrusive sampling methods. Seventeen samples were collected including plasma facing surfaces in lower, upper, and horizontal locations, surfaces behind floor tiles, surfaces behind divert or tiles, and surfaces behind ceiling tiles. The results of the analysis are presented.

  14. Validation testing of radioactive waste drum filter vents

    Energy Technology Data Exchange (ETDEWEB)

    Weber, L.D. [Pall Corp., Port Washington, NY (United States); Rahimi, R.S. [Pall Corp., Cortland, NY (United States); Edling, D. [Edling & Associates, Inc., Russel Springs, KY (United States)


    The minimum requirements for Drum Filter Vents (DFVs) can be met by demonstrating conformance with the Waste Isolation Pilot Plant (WIPP) Trupact II Safety Assessment Report (SAR), and conformance with U.S. Federal shipping regulations 49 CFR 178.350, DOT Spec 7A, for Type A packages. These together address a number of safety related performance parameters such as hydrogen diffusivity, flow related pressure drop, filtration efficiency and, separately, mechanical stability and the ability to prevent liquid water in-leakage. In order to make all metal DFV technology (including metallic filter medium) available to DOE sites, Pall launched a product development program to validate an all metal design to meet these requirements. Numerous problems experienced by DOE sites in the past came to light during this development program. They led us to explore enhancements to DFV design and performance testing addressing these difficulties and concerns. The result is a patented all metal DFV certified to all applicable regulatory requirements, which for the first time solves operational and health safety problems reported by DOE site personnel but not addressed by previous DFV`s. The new technology facilitates operations (such as manual, automated and semi-automated drum handling/redrumming), sampling, on-site storage, and shipping. At the same time, it upgrades filtration efficiency in configurations documented to maintain filter efficiency following mechanical stress. 2 refs., 2 figs., 10 tabs.

  15. Unit vent airflow measurements using a tracer gas technique

    Energy Technology Data Exchange (ETDEWEB)

    Adams, D.G. [Union Electric Company, Fulton, MO (United States); Lagus, P.L. [Lagus Applied Technology, Inc., San Diego, CA (United States); Fleming, K.M. [NCS Corp., Columbus, OH (United States)


    An alternative method for assessing flowrates that does not depend on point measurements of air flow velocity is the constant tracer injection technique. In this method one injects a tracer gas at a constant rate into a duct and measures the resulting concentration downstream of the injection point. A simple equation derived from the conservation of mass allows calculation of the flowrate at the point of injection. Flowrate data obtained using both a pitot tube and a flow measuring station were compared with tracer gas flowrate measurements in the unit vent duct at the Callaway Nuclear Station during late 1995 and early 1996. These data are presented and discussed with an eye toward obtaining precise flowrate data for release rate calculations. The advantages and disadvantages of the technique are also described. In those test situations for which many flowrate combinations are required, or in large area ducts, a tracer flowrate determination requires fewer man-hours than does a conventional traverse-based technique and does not require knowledge of the duct area. 6 refs., 10 figs., 6 tabs.

  16. Microscopic bubble behaviour in suppression pool during wetwell venting (United States)

    Zablackaite, G.; Nagasaka, H.; Kikura, H.


    During a severe accident PCV failure should be avoided and fission products inside PCV should be confined as much as possible. In order to minimize FPs release, Wetwell venting is conducted by releasing steam-non-condensable gas mixture carrying FPs from the Drywell to Suppression Pool. Steam is condensed by subcooled water in the pool, and most of FPs are retained into water. The removal of FP in the water pool is referred to as “Pool Scrubbing effect”. Hydrodynamic parameters of bubbles have impact on pool scrubbing effect. However, there is only few data available to evaluate quantitatively the bubble behaviour under depressurization and/or thermal stratification conditions. Series of experiments were conducted to evaluate the influence of temperature distribution, non-condensable gas content and pressure in the Wetwell on bubble behaviour. Bubbles were visualized using High Speed Camera and adopting shadowgraphy technique. Applying Particle Tracking Velocimetry, bubble velocity and size distribution were obtained from recorded images. Experimental results show that with increasing suppression pool temperature, bubbles reaching the pool surface decreased in size and traveling velocity became slower. In pressurized wetwell, bubble behaviour was similar to that in the heated up suppression pool case, although bubble parameters were similar to the low temperature case. Higher air content induced water surface movement and bubbles were smaller due to break up.

  17. Pratiques de publicité au point de vente dans l'industrie du tabac ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    On entend ici, par " publicité au point de vente ", la présence d'articles promotionnels là où se vendent les produits du tabac. Des études menées dans des pays comme le Canada démontrent que la publicité au point de vente exerce une influence importante sur les écoliers et peut les prédisposer à devenir fumeurs.

  18. Cloaca-vent prolapsed in a Lutino fischer’s love bird (Agapornis fischeri

    Directory of Open Access Journals (Sweden)

    Dibyendu Biswas


    Full Text Available Cloacal-vent prolapse in a bird is often fatal if left untreated. A 10-month-old female love bird was brought to teaching veterinary hospital, Chittagong Veterinary and Animal Sciences University, Bangladesh, due to an everted cloaca through the vent. This condition was treated successfully by washing, massage, and icing. Calcium was supplemented orally for five days and the bird was cured completely after seven days.

  19. 40 CFR 63.492 - Batch front-end process vents-reporting requirements. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents-reporting... Batch front-end process vents—reporting requirements. (a) The owner or operator of a batch front-end... Compliance Status specified in § 63.506(e)(5). (1) For each batch front-end process vent complying with § 63...

  20. Arsenic speciation in food chains from mid-Atlantic hydrothermal vents


    Taylor, Vivien F.; Jackson, Brian P.; Siegfried, Matthew; Navratilova, Jana; Francesconi, Kevin A.; Kirshtein, Julie; Voytek, Mary


    Arsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge hydrothermal vents. The shrimp species, Rimicaris exoculata, the vent chimney-dwelling mussel, Bathymodiolus azoricus, Branchipolynoe seepensis, a commensal worm of B. azoricus, and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (δ13C and δ15N) signature between species, suggesting different sources of As uptake. A...

  1. Metal influence on metallothionein synthesis in the hydrothermal vent mussel Bathymodiolus thermophilus


    Hardivillier, Yann; Denis, Françoise; Demattei, Marie-Véronique; Bustamante, Paco; Laulier, Marc; Cosson, Richard,


    International audience; The present study reports on the metallothionein expression in the hydrothermal vent mussel Bathymodiolus thermophilus. Metallothioneins (MT) are proteins involved in intracellular metal regulation and conserved throughout the animal kingdom. The hydrothermal vent environment presents peculiarities (high levels of sulfides and metals, low pH, anoxia) that may have driven associated species to develop original evolutionary ways to face these extreme living conditions. M...

  2. Virioplankton and bacterioplankton in a shallow CO 2-dominated hydrothermal vent (Panarea Island, Tyrrhenian Sea) (United States)

    Karuza, Ana; Celussi, Mauro; Cibic, Tamara; Del Negro, Paola; De Vittor, Cinzia


    Gas hydrothermal vents are used as a natural analogue for studying the effects of CO 2 leakage from hypothetical shallow marine storage sites on benthic and pelagic systems. This study investigated the interrelationships between planktonic prokaryotes and viruses in the Panarea Islands hydrothermal system (southern Tyrrhenian Sea, Italy), especially their abundance, distribution and diversity. No difference in prokaryotic abundance was shown between high-CO 2 and control sites. The community structure displayed differences between fumarolic field and the control, and between surface and bottom waters, the latter likely due to the presence of different water masses. Bacterial assemblages were qualitatively dominated by chemo- and photoautotrophic organisms, able to utilise both CO 2 and H 2S for their metabolic requirements. From significantly lower virioplankton abundance in the proximity of the exhalative area together with particularly low Virus-to-Prokaryotes Ratio, we inferred a reduced impact on prokaryotic abundance and proliferation. Even if the fate of viruses in this particular condition remains still unknown, we consider that lower viral abundance could reflect in enhancing the energy flow to higher trophic levels, thus largely influencing the overall functioning of the system.

  3. Iron oxide deposits associated with the ectosymbiotic bacteria in the hydrothermal vent shrimp Rimicaris exoculata (United States)

    Corbari, L.; Cambon-Bonavita, M.-A.; Long, G. J.; Grandjean, F.; Zbinden, M.; Gaill, F.; Compère, P.


    The Rimicaris exoculata shrimp is considered a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR) hydrothermal ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the minerals associated with these bacteria have been investigated by using X-ray microanalyses, light microscopy, and transmission, environmental scanning and scanning transmission electron microscopy. The nature of the iron oxides in shrimps obtained from the Rainbow vent field at 36°14.0' N, has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three step-levels of mineral crust found in the Rimicaris exoculata shrimps consist of heavy concretions formed by nanoparticles of two-line ferrihydrite intermixed with minor inorganic SiO2, (Ca,Mg)SO4, and (Ca,Mg)3(PO4)2 minerals that may stabilise the ferrihydrite form of iron oxides. Morphological observations on the bacteria have revealed their close interactions with these minerals and, thus, indicate the biogenic origin of the iron oxide deposits. The evolution of the bacterial density in the three mineral crust levels is related to the amount of the iron deposits and it is proposed that the lower crust level is the most likely region for the location of the iron-oxidizing bacteria.

  4. Iron oxide deposits associated with the ectosymbiotic bacteria in the hydrothermal vent shrimp Rimicaris exoculata

    Directory of Open Access Journals (Sweden)

    P. Compère


    Full Text Available The Rimicaris exoculata shrimp is considered as a primary consumer that dominates the fauna of most Mid-Atlantic Ridge (MAR hydrothermal ecosystems. These shrimps harbour in their gill chambers an important ectosymbiotic community of chemoautotrophic bacteria associated with iron oxide deposits. The structure and elemental composition of the mineral concretions associated with these bacteria have been investigated by using LM, ESEM, TEM STEM and EDX microanalyses. The nature of the iron oxides in shrimps obtained from the Rainbow vent field has also been determined by Mössbauer spectroscopy. This multidisciplinary approach has revealed that the three layers of mineral crust in the Rimicaris exoculata shrimps consist of large concretions formed by aggregated nanoparticles of two-line ferrihydrite and include other minor elements as Si, Ca, Mg, S and P, probably present as silicates cations, sulphates or phosphates respectively that may contribute to stabilise the ferrihydrite form of iron oxides. TEM-observations on the bacteria have revealed their close interactions with these minerals. Abiotic and biotic precipitation could occur within the gill chamber of Rimicaris exoculata, suggesting the biologically-mediated formation of the iron oxide deposits. The difference of the bacterial density in the three-mineral crust layers could be correlated to the importance of the iron oxide concretions and suggest that the first mineral particles precipitates on the lower layer which could be considered as the most likely location of iron-oxidizing bacteria.

  5. Beyond the vent: New perspectives on hydrothermal plumes and pelagic biology (United States)

    Phillips, Brennan T.


    Submarine hydrothermal vent fields introduce buoyant plumes of chemically altered seawater to the deep-sea water column. Chemoautotrophic microbes exploit this energy source, facilitating seafloor-based primary production that evidence suggests may transfer to pelagic consumers. While most hydrothermal plumes have relatively small volumes, there are recent examples of large-scale plume events associated with periods of eruptive activity, which have had a pronounced effect on water-column biology. This correlation suggests that hydrothermal plumes may have influenced basin-scale ocean chemistry during periods of increased submarine volcanism during the Phanerozoic eon. This paper synthesizes a growing body of scientific evidence supporting the hypothesis that hydrothermal plumes are the energetic basis of unique deep-sea pelagic food webs. While many important questions remain concerning the biology of hydrothermal plumes, this discussion is not present in ongoing management efforts related to seafloor massive sulfide (SMS) mining. Increased research efforts, focused on high-resolution surveys of midwater biology relative to plume structures, are recommended to establish baseline conditions and monitor the impact of future mining-based disturbances to the pelagic biosphere.

  6. Elemental mercury at submarine hydrothermal vents in the Bay of Plenty, Taupo volcanic zone, New Zealand (United States)

    Stoffers, P.; Hannington, M.; Wright, I.; Herzig, P.; de Ronde, C.; Scientific Party, Shipboard


    Hot springs in active geothermal areas such as Yellowstone National Park, the Geysers geothermal field in California, and the Taupo volcanic zone in New Zealand are notably enriched in the trace metals Au, Ag, As, Sb, and Hg. Such near-surface hot springs have formed many of the world's important deposits of gold and silver and some of the largest deposits of mercury. The majority of these are associated with continental geothermal systems in subaerial environments. Here we report the discovery of active mercury-depositing hot springs in a submarine setting, at nearly 200 m water depth, within the offshore extension of the Taupo volcanic zone of New Zealand. These vents contain the first documented occurrence of elemental mercury on the sea floor and provide an important link between offshore hydrothermal activity and mercury-depositing geothermal systems on land. The discovery has implications for mercury transport in sea-floor hydrothermal systems and underscores the importance of submarine volcanic and geothermal activity as a source of mercury in the oceans.

  7. Complete mitochondrial genome of the blind vent crab Gandalfus puia (Crustacea: Bythograeidae) from the Tonga Arc. (United States)

    Kim, Se-Joo; Moon, Jai-Woon; Ju, Se-Jong


    The brachyuran crab Gandalfus puia is a species endemic to the hydrothermal vent fields in the Tonga-Kermadec Arc. In order to understand G. puia at the genomic level, we sequenced its mitochondrial genome (mitogenome) and then compared to other bythograeids. The mitogenome is 15,548 bp in length and exhibits brachyuran-typical gene arrangement. Its protein-coding genes were very similar to other bythograeid species with respect to length, AT content and start and stop codons. Additionally, we compared the mitogenomes of Gandalfus and the closely related Austinograea. The inter-specific nucleotide divergence was 13.4% in Gandalfus and 13.7-14.0% in Austinograea. The inter-generic nucleotide divergence between Gandalfus and Austinograea was 16.3-19.7%. Based on the phylogenetic tree constructed with maximum likelihood and Bayesian inference, bythograeid crabs were recognized as the monophyletic taxon with the high supporting values (100% bootstrap proportions and 1.00 posterior probabilities). These results are useful for understanding the phylogenetic relationships and evolution of bythograeid crabs.

  8. Quaternary fault-controlled volcanic vents and crustal thinning: new insights from the magma-rich Tyrrhenian passive margin (Italy) (United States)

    Cardello, Giovanni Luca; Conti, Alessia; Consorti, Lorenzo; Do Couto, Damien


    The discover of monogenic Quaternary volcanic vents, that were recently mapped along major fault zones both inland and offshore the Tyrrhenian magma-rich passive margin, poses questions about: timing and role they had into Plio-Pleistocene crustal thinning with relevant consequences for the hazard assessment of an area inhabited by some 0.5 million people. The present-day margin is stretched over 100 km between the Volsci Range (VR) and the Pontian escarpment, being defined by moderate shallow seismicity (Mw≤4.6), relative high geothermal gradient and ongoing hydrothermal activity. Although major central volcanoes (e.g., Colli Albani), occurring at major fault intersections are well studied, smaller volcanic fields were so far unconstrained. Both field survey in the VR and offshore high-resolution geophysical data, allow us to: 1) better define the anatomy of the poorly known VR volcanic field; 2) furnish new insights on the regional Quaternary dynamics; 3) propose modes and reason of magma emplacement. The VR is composed of about 40 punctual and linear monogenic and mostly phreatomagmatic vents occurring at the edges of the Apennine carbonate fold-and-thrust belt and within the VR backbone. Volcanites are characterized by zeolitized to incoherent tuffs and surge deposits locally covered by lavas and slope deposits. Most explosive units host carbonate-rich lithics with different degrees of rounding and decarbonation, which frequently belong to Albian-Cenomanian aquifers. By comparing cross-section with lithic analyses we demonstrate that fragmentation, transport, progressive disintegration and decarbonation occur at multiple depths, depending on the fold-and-thrust belt setting. Thus, along the same vent zone, juvenile lithic composition proves repeated fragmentation within pressured-aquifers, testifying for fissural activity with implications for local seismic and volcanic assessment. Pyroclastic deposits occur as well in the Pontina and Fondi coastal plains at

  9. Hazard evaluation of inorganics, singly and in mixtures, to Flannelmouth Sucker Catostomus latipinnis in the San Juan River, New Mexico (United States)

    Hamilton, S.J.; Buhl, K.J.


    Larval flannelmouth sucker (Catostomus latipinnis) were exposed to arsenate, boron, copper, molybdenum, selenate, selenite, uranium, vanadium, and zinc singly, and to five mixtures of five to nine inorganics. The exposures were conducted in reconstituted water representative of the San Juan River near Shiprock, New Mexico. The mixtures simulated environmental ratios reported for sites along the San Juan River (San Juan River backwater, Fruitland marsh, Hogback East Drain, Mancos River, and McElmo Creek). The rank order of the individual inorganics, from most to least toxic, was: copper > zinc > vanadium > selenite > selenate > arsenate > uranium > boron > molybdenum. All five mixtures exhibited additive toxicity to flannelmouth sucker. In a limited number of tests, 44-day-old and 13-day-old larvae exhibited no difference in sensitivity to three mixtures. Copper was the major toxic component in four mixtures (San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek), whereas zinc was the major toxic component in the Fruitland marsh mixture, which did not contain copper. The Hogback East Drain was the most toxic mixture tested. Comparison of 96-h LC50values with reported environmental water concentrations from the San Juan River revealed low hazard ratios for arsenic, boron, molybdenum, selenate, selenite, uranium, and vanadium, moderate hazard ratios for zinc and the Fruitland marsh mixture, and high hazard ratios for copper at three sites and four environmental mixtures representing a San Juan backwater, Hogback East Drain, Mancos River, and McElmo Creek. The high hazard ratios suggest that inorganic contaminants could adversely affect larval flannelmouth sucker in the San Juan River at four sites receiving elevated inorganics.

  10. Management of turbidity current venting in reservoirs under different bed slopes. (United States)

    Chamoun, Sabine; De Cesare, Giovanni; Schleiss, Anton J


    The lifetime and efficiency of dams is endangered by the process of sedimentation. To ensure the sustainable use of reservoirs, many sediment management techniques exist, among which venting of turbidity currents. Nevertheless, a number of practical questions remain unanswered due to a lack of systematic investigations. The present research introduces venting and evaluates its performance using an experimental model. In the latter, turbidity currents travel on a smooth bed towards the dam and venting is applied through a rectangular bottom outlet. The combined effect of outflow discharge and bed slopes on the sediment release efficiency of venting is studied based on different criteria. Several outflow discharges are tested using three different bed slopes (i.e., 0%, 2.4% and 5.0%). Steeper slopes yield higher venting efficiency. Additionally, the optimal outflow discharge leading to the largest venting efficiency with the lowest water loss increases when moving from the horizontal bed to the inclined positions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. The discovery of new deep-sea hydrothermal vent communities in the southern ocean and implications for biogeography.

    Directory of Open Access Journals (Sweden)

    Alex D Rogers


    Full Text Available Since the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp., stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae, bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more

  12. The Discovery of New Deep-Sea Hydrothermal Vent Communities in the Southern Ocean and Implications for Biogeography (United States)

    Rogers, Alex D.; Tyler, Paul A.; Connelly, Douglas P.; Copley, Jon T.; James, Rachael; Larter, Robert D.; Linse, Katrin; Mills, Rachel A.; Garabato, Alfredo Naveira; Pancost, Richard D.; Pearce, David A.; Polunin, Nicholas V. C.; German, Christopher R.; Shank, Timothy; Boersch-Supan, Philipp H.; Alker, Belinda J.; Aquilina, Alfred; Bennett, Sarah A.; Clarke, Andrew; Dinley, Robert J. J.; Graham, Alastair G. C.; Green, Darryl R. H.; Hawkes, Jeffrey A.; Hepburn, Laura; Hilario, Ana; Huvenne, Veerle A. I.; Marsh, Leigh; Ramirez-Llodra, Eva; Reid, William D. K.; Roterman, Christopher N.; Sweeting, Christopher J.; Thatje, Sven; Zwirglmaier, Katrin


    Since the first discovery of deep-sea hydrothermal vents along the Galápagos Rift in 1977, numerous vent sites and endemic faunal assemblages have been found along mid-ocean ridges and back-arc basins at low to mid latitudes. These discoveries have suggested the existence of separate biogeographic provinces in the Atlantic and the North West Pacific, the existence of a province including the South West Pacific and Indian Ocean, and a separation of the North East Pacific, North East Pacific Rise, and South East Pacific Rise. The Southern Ocean is known to be a region of high deep-sea species diversity and centre of origin for the global deep-sea fauna. It has also been proposed as a gateway connecting hydrothermal vents in different oceans but is little explored because of extreme conditions. Since 2009 we have explored two segments of the East Scotia Ridge (ESR) in the Southern Ocean using a remotely operated vehicle. In each segment we located deep-sea hydrothermal vents hosting high-temperature black smokers up to 382.8°C and diffuse venting. The chemosynthetic ecosystems hosted by these vents are dominated by a new yeti crab (Kiwa n. sp.), stalked barnacles, limpets, peltospiroid gastropods, anemones, and a predatory sea star. Taxa abundant in vent ecosystems in other oceans, including polychaete worms (Siboglinidae), bathymodiolid mussels, and alvinocaridid shrimps, are absent from the ESR vents. These groups, except the Siboglinidae, possess planktotrophic larvae, rare in Antarctic marine invertebrates, suggesting that the environmental conditions of the Southern Ocean may act as a dispersal filter for vent taxa. Evidence from the distinctive fauna, the unique community structure, and multivariate analyses suggest that the Antarctic vent ecosystems represent a new vent biogeographic province. However, multivariate analyses of species present at the ESR and at other deep-sea hydrothermal vents globally indicate that vent biogeography is more complex than

  13. Variaciones de gravedad en el Valle de Tulum, San Juan: aportes a la caracterización sismotectónica de la región

    Directory of Open Access Journals (Sweden)

    Francisco Ruiz


    Full Text Available Con el objeto de establecer relaciones espacio-temporales de la evolución del campo gravitatorio debidas a actividad sismotectónica, se estableció una red de control geodésico areal (RED G1. La red está compuesta por puntos fijos bien materializados, abarca un área de 2500 km², con la ciudad de San Juan en su centro. Estos puntos fijos fueron vinculados con mediciones precisas de gravedad en los años 2000 y 2004. Las diferencias gravimétricas 2000-2004 se refirieron a la estación de gravedad del Instituto Geofísico Sismológico (UNSJ. El campo de variaciones relativas de gravedad así obtenido, muestra relaciones consistentes con la actividad sísmica de magnitud mayor que 3 (abundante en este período. Los rasgos más sobresalientes indican: A una alineación de máximos con variaciones de hasta +0.088 mGal en el sudoeste de la Sierra de Pie de Palo, +0.045 mGal en el Co. Barboza y de +0.065 en el Co. Valdivia. B Una zona de máximos (hasta 0.090 mGal en el centro-oeste de la Sa. Chica de Zonda correlacionada con nidos de sismos de magnitud 3 a 3.9. C Una marcada quietud en los puntos fijos ubicados al sur de la Sa. Chica de Zonda. D Ascenso generalizado de todos los puntos ubicados al norte del Río San Juan llegando a 0.080 mGal en la Falla de La Laja (Terremoto del 15-01-1944. Si atribuimos los cambios de g enteramente a cambios topográficos, las variaciones altimétricas estarían en el orden de los 10 cm.A network of areal geodetic control (Red G1 was set up with the purpose of establishing space-time relations in the evolution of the gravity field produced by seismo-tectonic activity. The network is composite for points well materialized in the field, and extends over an about 2500 km² area centered in the San Juan city. These fixed points were linked with precise gravity measurements carried out during years 2000 and 2004. The gravity changes 2000-2004 are evaluated taking as fix the gravity value in the Instituto Geof

  14. Liquid Oxygen Thermodynamic Vent System Testing with Helium Pressurization (United States)

    VanDresar, Neil T.


    This report presents the results of several thermodynamic vent system (TVS) tests with liquid oxygen plus a test with liquid nitrogen. In all tests, the liquid was heated above its normal boiling point to 111 K for oxygen and 100 K for nitrogen. The elevated temperature was representative of tank conditions for a candidate lunar lander ascent stage. An initial test series was conducted with saturated oxygen liquid and vapor at 0.6 MPa. The initial series was followed by tests where the test tank was pressurized with gaseous helium to 1.4 to 1.6 MPa. For these tests, the helium mole fraction in the ullage was quite high, about 0.57 to 0.62. TVS behavior is different when helium is present than when helium is absent. The tank pressure becomes the sum of the vapor pressure and the partial pressure of helium. Therefore, tank pressure depends not only on temperature, as is the case for a pure liquid-vapor system, but also on helium density (i.e., the mass of helium divided by the ullage volume). Thus, properly controlling TVS operation is more challenging with helium pressurization than without helium pressurization. When helium was present, the liquid temperature would rise with each successive TVS cycle if tank pressure was kept within a constant control band. Alternatively, if the liquid temperature was maintained within a constant TVS control band, the tank pressure would drop with each TVS cycle. The final test series, which was conducted with liquid nitrogen pressurized with helium, demonstrated simultaneous pressure and temperature control during TVS operation. The simultaneous control was achieved by systematic injection of additional helium during each TVS cycle. Adding helium maintained the helium partial pressure as the liquid volume decreased because of TVS operation. The TVS demonstrations with liquid oxygen pressurized with helium were conducted with three different fluid-mixer configurations-a submerged axial jet mixer, a pair of spray hoops in the tank

  15. Non-Venting Thermal and Humidity Control for EVA Suits (United States)

    Izenson, Mike; Chen, Weibo; Bue, Grant


    Future EVA suits need processes and systems to control internal temperature and humidity without venting water to the environment. This paper describes an absorption-based cooling and dehumidification system as well as laboratory demonstrations of the key processes. There are two main components in the system: an evaporation cooling and dehumidification garment (ECDG) that removes both sensible heat and latent heat from the pressure garment, and an absorber radiator that absorbs moisture and rejects heat to space by thermal radiation. This paper discusses the overall design of both components, and presents recent data demonstrating their operation. We developed a design and fabrication approach to produce prototypical heat/water absorbing elements for the ECDG, and demonstrated by test that these elements could absorb heat and moisture at a high flux. Proof-of-concept tests showed that an ECDG prototype absorbs heat and moisture at a rate of 85 W/ft under conditions that simulate operation in an EVA suit. The heat absorption was primarily due to direct absorption of water vapor. It is possible to construct large, flexible, durable cooling patches that can be incorporated into a cooling garment with this system. The proof-of-concept test data was scaled to calculate area needed for full metabolic loads, thus showing that it is feasible to use this technology in an EVA suit. Full-scale, lightweight absorber/radiator modules have also been built and tested. They can reject heat at a flux of 33 W/ft while maintaining ECDG operation at conditions that will provide a cool and dry environment inside the EVA suit.

  16. Evaluation of Passive Vents in New Construction Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Sean [Steven Winter Associates, Inc., Norwalk, CT (United States); Berger, David [Steven Winter Associates, Inc., Norwalk, CT (United States); Zuluaga, Marc [Steven Winter Associates, Inc., Norwalk, CT (United States)


    Exhaust ventilation and corresponding outdoor air strategies are being implemented in high-performance new construction multifamily buildings to meet program or code requirements for improved indoor air quality, but a lack of clear design guidance is resulting in poor performance of these systems despite the best intentions of the programs or standards. CARB's 2014 'Evaluation of Ventilation Strategies in New Construction Multifamily Buildings' consistently demonstrated that commonly used outdoor air strategies are not performing as expected. Of the four strategies evaluated in 2014, the exhaust ventilation system that relied on outdoor air from a pressurized corridor was ruled out as a potential best practice due to its conflict with meeting requirements within most fire codes. Outdoor air that is ducted directly to the apartments was a strategy determined to have the highest likelihood of success, but with higher first costs and operating costs. Outdoor air through space conditioning systems was also determined to have good performance potential, with proper design and execution. The fourth strategy, passive systems, was identified as the least expensive option for providing outdoor air directly to apartments, with respect to both first costs and operating costs. However, little is known about how they actually perform in real-world conditions or how to implement them effectively. Based on the lack of data available on the performance of these low-cost systems and their frequent use in the high-performance building programs that require a provision for outdoor air, this research project sought to further evaluate the performance of passive vents.

  17. Collective Protection (ColPro) Field Testing (United States)


    be independently reviewed and authenticated , as required by the test facility or the test program. h. All analysis calculations will be double...electronic control unit ( ECU ), exterior sampling lines/pumps, exhaust ports, etc.) will be conducted to verify the absence of intrusion sources...Outer Vent: GPFU: ECU : Vapor Monitor 1: Model #: Serial #: Field Location: Vapor

  18. Dengue Fever Trends and Climate Change in San Juan, Puerto Rico (United States)

    Muller-Karger, F. E.; Mendez-Lazaro, P.; Otis, D. B.; McCarthy, M.; Pena-Orellana, M.


    Climate change has important implications for public health. We developed and tested the hypothesis that conditions for dengue fever transmission in San Juan (Puerto Rico, USA) are becoming favorable as a result of meteorological drivers being modified with climate change. Sea level pressure, mean sea level (MSL), wind, sea surface temperature (SST), air surface temperature (AST), rainfall, and confirmed dengue cases were variables examined over the past 30 years, or longer for some variables. Statistical tools used included Principal Component Analysis, Pearson correlation coefficient, Mann-Kendall trend tests, and logistic regressions. Results show that dry days are increasing and that wet days are decreasing. MSL is steadily increasing, which increases the risk of dengue cases along the coast, as the perimeter of the San Juan Bay estuary expands and the shoreline moves inland. Warming is evident in both SST and AST. Maximum and minimum air surface temperature extremes have also increased. Incidence of dengue is accelerating along with environmental change. For example, between 2000-2011, dengue transmission increased by a factor of 3.4 (95% CI: 1.9-6.1) for each 1ºC increase in SST. Between 2007 and 2011, this risk factor increased to 5.2 (95% CI: 1.9-13.9) for every 1ºC increase in SST. An important but difficult to examine problem is how social and economic factors affect such dengue fever transmission rates in light of environmental change. A concern is that the patterns observed in San Juan are representative of potential incidence of dengue virus in other parts of the island of Puerto Rico and in other Caribbean nations. These results help understand patterns of disease spreading, and allow public health officials to evaluate scenarios and interventions intended to mitigate the impacts of climate change.

  19. Las correcciones de Juan Rejano. En torno a Canciones de la paz (1955

    Directory of Open Access Journals (Sweden)

    Luján Atienza, Ángel Luis


    Full Text Available The aim of this paper is to explain the reasons for Juan Rejano to have removed his book Canciones de la paz (Songs for the Peace, 1955 from his first almost complete poems collection, Alas de tierra (Wings of Earth, 1975, and to modify it in his last «collected poems», La mirada del hombre (The Man’s Sight, 1978. In this paper, the circumstances under which the book was written will be analysed, these being linked to the World Movement for Peace and being deeply influenced by the P.C.E. (Spanish Communist Party exhortations. The study of textual variants, deleted poems and new assignments in finished poems reveals that Juan Rejano feels uncomfortable with the combative voice of this part of his work as the instrument to reveal the ugliest side in contemporary life. In addition, this book, intended to be written for children, does not fit in young readers literature.Este artículo trata de dar cuenta de las razones que llevaron a Juan Rejano a eliminar el libro Canciones de la paz (1955 de su primera gran recopilación, Alas de tierra (1975, y a modificarlo sustancialmente en su última suma poética, La mirada del hombre (1978. Con el análisis de las circunstancias en que nació el libro, vinculado al Movimiento Mundial por la Paz e influenciado por las consignas del PCE, y con el estudio de variantes, poemas eliminados y poemas reubicados, podemos aventurar que Rejano no se sentía cómodo con la parte más combativa del libro y con la que presentaba la faceta más sombría de la realidad contemporánea, además de que no cabía el adoctrinamiento en una escritura explícitamente dirigida a los niños.

  20. Community-based enterprises and the commons: The case of San Juan Nuevo Parangaricutiro, Mexico

    Directory of Open Access Journals (Sweden)

    Alejandra Orozco-Quintero


    Full Text Available Commons scholarship has tended to focus on the administration and use of commons by individuals and households and less so on collective enterprises that extract, transform and market what they harvest from the commons. In this paper, we consider Nuevo San Juan, a Mexican case that is well known in the community forestry and commons literature. In San Juan, indigenous community members who hold the rights for the commons are also the members of the enterprise that transforms and markets goods from the commons. We argue that such a strategy is one way to confront internal and external pressures on a commons. We draw upon the transcripts of 40 interviews undertaken during 2006 which are analyzed using a framework developed from the social, community-based and indigenous enterprise literature. Our goal was to utilize this framework to analyze the San Juan Forest Enterprise and understand its emergence and formation as a long-standing community-based enterprise that intersects with a commons, and thereby identify factors that increase chances of success for community enterprises. We found that by starting from the community-based and indigenous enterprise literature and using that literature to engage with thinking on commons, it was possible to consider the enterprise from the perspective of a regulatory framework rather than from the poles of dependency and modernization theories in which much commons work has been based. Enterprise and commons intersect when both are guided by core cultural values and the enterprise can become a new site for the creation of social and cultural cohesion. We also found that there were a number of necessary conditions for commons-based community-enterprises to retain internal and external legitimacy, namely: (1 leadership representative of the broad social mission rooted in the customary institutions, values and norms of the community; (2 accountability of enterprise leaders to the memberships they represent; and (3

  1. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots.

    Directory of Open Access Journals (Sweden)

    Alan M Friedlander

    Full Text Available The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA, in Desventuradas, the laminarian kelp (Eisenia cokeri, which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC, in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.

  2. Marine Biodiversity in Juan Fernández and Desventuradas Islands, Chile: Global Endemism Hotspots. (United States)

    Friedlander, Alan M; Ballesteros, Enric; Caselle, Jennifer E; Gaymer, Carlos F; Palma, Alvaro T; Petit, Ignacio; Varas, Eduardo; Muñoz Wilson, Alex; Sala, Enric


    The Juan Fernández and Desventuradas islands are among the few oceanic islands belonging to Chile. They possess a unique mix of tropical, subtropical, and temperate marine species, and although close to continental South America, elements of the biota have greater affinities with the central and south Pacific owing to the Humboldt Current, which creates a strong biogeographic barrier between these islands and the continent. The Juan Fernández Archipelago has ~700 people, with the major industry being the fishery for the endemic lobster, Jasus frontalis. The Desventuradas Islands are uninhabited except for a small Chilean military garrison on San Félix Island. We compared the marine biodiversity of these islands across multiple taxonomic groups. At San Ambrosio Island (SA), in Desventuradas, the laminarian kelp (Eisenia cokeri), which is limited to Desventuradas in Chile, accounted for >50% of the benthic cover at wave exposed areas, while more sheltered sites were dominated by sea urchin barrens. The benthos at Robinson Crusoe Island (RC), in the Juan Fernández Archipelago, comprised a diverse mix of macroalgae and invertebrates, a number of which are endemic to the region. The biomass of commercially targeted fishes was >2 times higher in remote sites around RC compared to sheltered locations closest to port, and overall biomass was 35% higher around SA compared to RC, likely reflecting fishing effects around RC. The number of endemic fish species was extremely high at both islands, with 87.5% of the species surveyed at RC and 72% at SA consisting of regional endemics. Remarkably, endemics accounted for 99% of the numerical abundance of fishes surveyed at RC and 96% at SA, which is the highest assemblage-level endemism known for any individual marine ecosystem on earth. Our results highlight the uniqueness and global significance of these biodiversity hotspots exposed to very different fishing pressures.

  3. El mito de Don Juan en el cine: De Molière a Jacques Weber

    Directory of Open Access Journals (Sweden)

    Becerra Suárez, Carmen


    Full Text Available From its birth in Spain in the 17th century, the myth of Don Juan has been explored through a diversity of genres, approached by numerous artists, from a wide range of perspectives and artistic expressions, interpreted by philosophers and studied by scientists. This article analyzes the modifications that the mythic scenario displays in Jacques Weber’s cinematographic version, taking into account the specific issues related to the shift of language, from literature to cinema, alongside other aspects of similar interest. Furthermore, given the fact that the study case is the result of a film transposition from a particular literary text, in this case Molière’s account of Don Juan, we will analyse, first and foremost, the suitability of the original literary text to the mythic discourse.

    Desde su nacimiento en el siglo XVII español, el mito de Don Juan ha sido vertido en diferentes géneros, abordado por numerosos creadores, desde perspectivas y expresiones artísticas diversas, interpretado por filósofos y estudiado por científicos. Este artículo analiza las modificaciones que el escenario mítico presenta en la versión cinematográfica de Jacques Weber, teniendo en cuenta, además de otras causas de semejante interés, las relacionadas con el cambio de lenguaje: de la literatura al cine. Pero además, como el film estudiado es el resultado de la transposición fílmica de un texto literario particular, en este caso la versión donjuanesca de Molière, se analiza, en primer lugar, la adecuación al discurso mítico del texto literario de partida.

  4. A heat vulnerability index to improve urban public health management in San Juan, Puerto Rico. (United States)

    Méndez-Lázaro, Pablo; Muller-Karger, Frank E; Otis, Daniel; McCarthy, Matthew J; Rodríguez, Ernesto


    Increased frequency and length of high heat episodes are leading to more cardiovascular issues and asthmatic responses among the population of San Juan, the capital of the island of Puerto Rico, USA. An urban heat island effect, which leads to foci of higher temperatures in some urban areas, can raise heat-related mortality. The objective of this research is to map the risk of high temperature in particular locations by creating heat maps of the city of San Juan. The heat vulnerability index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor flown on Landsat 8. Social determinants (e.g., age, unemployment, education and social isolation, and health insurance coverage) were analyzed by census tract. The data were examined in the context of land cover maps generated using products from the Puerto Rico Terrestrial Gap Analysis Project (USDA Forest Service). All variables were set in order to transform the indicators expressed in different units into indices between 0 and 1, and the HVI was calculated as sum of score. The tract with highest index was considered to be the most vulnerable and the lowest to be the least vulnerable. Five vulnerability classes were mapped (very high, high, moderate, low, and very low). The hottest and the most vulnerable tracts corresponded to highly built areas, including the Luis Munoz International Airport, seaports, parking lots, and high-density residential areas. Several variables contributed to increased vulnerability, including higher rates of the population living alone, disabilities, advanced age, and lack of health insurance coverage. Coolest areas corresponded to vegetated landscapes and urban water bodies. The urban HVI map will be useful to health officers, emergency preparedness personnel, the National Weather Service, and San Juan residents, as it helps to prepare for and to mitigate

  5. A heat vulnerability index to improve urban public health management in San Juan, Puerto Rico (United States)

    Méndez-Lázaro, Pablo; Muller-Karger, Frank E.; Otis, Daniel; McCarthy, Matthew J.; Rodríguez, Ernesto


    Increased frequency and length of high heat episodes are leading to more cardiovascular issues and asthmatic responses among the population of San Juan, the capital of the island of Puerto Rico, USA. An urban heat island effect, which leads to foci of higher temperatures in some urban areas, can raise heat-related mortality. The objective of this research is to map the risk of high temperature in particular locations by creating heat maps of the city of San Juan. The heat vulnerability index (HVI) maps were developed using images collected by satellite-based remote sensing combined with census data. Land surface temperature was assessed using images from the Thermal Infrared Sensor flown on Landsat 8. Social determinants (e.g., age, unemployment, education and social isolation, and health insurance coverage) were analyzed by census tract. The data were examined in the context of land cover maps generated using products from the Puerto Rico Terrestrial Gap Analysis Project (USDA Forest Service). All variables were set in order to transform the indicators expressed in different units into indices between 0 and 1, and the HVI was calculated as sum of score. The tract with highest index was considered to be the most vulnerable and the lowest to be the least vulnerable. Five vulnerability classes were mapped (very high, high, moderate, low, and very low). The hottest and the most vulnerable tracts corresponded to highly built areas, including the Luis Munoz International Airport, seaports, parking lots, and high-density residential areas. Several variables contributed to increased vulnerability, including higher rates of the population living alone, disabilities, advanced age, and lack of health insurance coverage. Coolest areas corresponded to vegetated landscapes and urban water bodies. The urban HVI map will be useful to health officers, emergency preparedness personnel, the National Weather Service, and San Juan residents, as it helps to prepare for and to mitigate

  6. Larval dispersal and life cycle in deep-water hydrothermal vents : the case of Rimicaris exoculata and related species


    Hernández Ávila, Iván


    Deep-water hydrothermal vent host high-biomass communities based on chemoautotrophy supported by the metabolic activity of free-living and symbiotic bacteria associated to invertebrates, especially megafauna. Knowledge on the mechanisms of dispersal and the life cycle of vent species is essential to our understanding of the vent communities in terms of distribution, structure and temporal variation. In this study, I present some advances regarding the dispersal and life cycle of a dominant sp...

  7. Knowledge to serve the city: insights from an emerging knowledge-action network to address vulnerability and sustainability in San Juan, Puerto Rico (United States)

    T.A. Munoz-Erickson; A.E. Lugo; E. Melendez-Ackerman; L.E. Santiago-Acevedo; J. Seguinot-Barbosa; P. Mendez-Lazaro


    This paper presents initial efforts to establish the San Juan Urban Long-Term Research Area Exploratory (ULTRA-Ex), a long-term program aimed at developing transdisciplinary social-ecological system (SES) research to address vulnerability and sustainability for the municipality of San Juan. Transdisciplinary approaches involve the collaborations between researchers,...

  8. 78 FR 37788 - In the Matter of: Juan Ricardo Puente-Paez, Inmate Number #05086-379, FCI McDowell, Federal... (United States)


    ... Bureau of Industry and Security In the Matter of: Juan Ricardo Puente-Paez, Inmate Number 05086-379, FCI..., Juan Ricardo Puente-Paez (``Puente-Paez'') was convicted of violating Section 38 of the Arms Export Control Act (22 U.S.C. 2778 (2006 & Supp. IV 2010)) (``AECA''). Specifically, Puente-Paez was convicted of...

  9. A GPR survey on degraded permafrost at Mesón San Juan, Mendonza, Argentina


    Travassos, Jandyr de Menezes; Stael, Giovanni Chaves; Liaudat, Dario Trombotto


    This work presents some geophysical results obtained at Mesón San Juan located in the Central Andes (6,012 m, 33°30' Sand 69°49' W), on the border of Argentina and Chile. The permafrost plateau (4,400 m) situated at the loot of the glacier is limited by recent moraines produced by cryogenic phenomena. The geophysical results revealed lateral differences in the dielectric characteristics of the subsurface due to varying water contents, allowing a zoning of the permafrost structure. We have c...





    Se analizó la dinámica del Humedal Juan Amarillo durante el periodo comprendido entre los años 1950-2005. Los resultados muestran que la configuración paisajística del ecosistema ha cambiado notoriamente con una tendencia al incremento en el número, tamaño y tipo de parches. Igualmente se presentan diferencias estructurales importantes entre los diversos periodos de tiempo analizados, ocasionados principal- mente por la disminución y desaparición de espejos de agua y el aumento de pasto kikuy...



    Alejandro, Hermosilla Sánchez


    En el presente artículo nos proponemos llevar a cabo un análisis de la novela del mexicano Juan Villoro, El testigo. Este análisis nos permitirá no sólo conocer mejor cómo y de qué manera aparece México en esta y otras novelas de Villoro, sino, además y más importante aún, la importancia de López Velarde y la ironía en su obra así como su significado final.

  12. Sobre la etnografía medieval : el oriente de Marco Polo y Juan de Mandevilla


    Aníbal A. Biglieri


    Este artículo estudia la visión del Oriente en las traducciones al aragonés de los libros de Marco Polo y John Mandeville. En particular, se analizan el Oriente y sus muchedumbres, las “nuevas maravillas" de Marco Polo y las maravillas etnográficas de Juan de Mandevilla. This article analyzes the image of the Orient in the aragonese translations of the books by Marco Polo and John Mandeville. In particular, it focuses on the multitudes, the “new marvels" by Marco Polo and the ethnographic ...

  13. Juan de Miralles: Un comerciante cubano en la guerra de independencia norteamericana


    Böttcher, Nikolaus


    El presente artículo analiza las actividades mercantiles y políticas del comerciante habanero Juan de Miralles como comisionado de la Corona española en Norteamérica durante la revolución de las trece colonias contra Inglaterra. La presencia de Miralles marcó el principio de las relaciones comerciales y diplomáticas entre Cuba y Norteamérica. El caso de este cubano es un ejemplo importante de la función del comerciante como intermediario en los procesos comerciales, culturales e incluso polít...

  14. Aplicaciones para la Gestión Automatizada de Procedimientos en la Universidad Rey Juan Carlos


    Rodríguez Ortego, Lorena; Juan Carlos Hernández Gutiérrez


    Proyecto Fin de Carrera leído en la Universidad Rey Juan Carlos en el curso académico 2009/2010. Tutor del Proyecto: Javier Mart nez Moguerza Internet y las Nuevas Tecnologías han ido cogiendo cada día más y más importancia en nuestras vidas, podemos ver que uno de los grandes beneficios que nos aportan es la simplificación de ciertas tareas que cometemos a diario las personas. Esta simplificación presente en muchos _ámbitos de nuestra vida, ya sea personal o profesional, va desd...

  15. África, memoria musical del río San Juan


    Martínez Peña, Oscar Giovanni; Fundador de la Escuela de Formación Artística de Palmira EFA y director académico en la misma institución desde 2008.


    Las migraciones humanas en Colombia, causadas por necesidades económicas y grupos armados, producen a su vez migraciones culturales, desplazamientos de cosmovisiones y percepciones artísticas. La región Pacífico no es ajena a estas problemáticas y el grupo África, como exponente de la música chocoana, representa un claro ejemplode esta situación. Sus integrantes, venidos de la región del río San Juan, llegan a Palmira en la búsqueda de oportunidades dentro de la industria azucarera, trayendo ...

  16. Cuentos terroríficos del antiguo Juan Viñas: El Sitio.


    Quesada Vargas, María


    Cuentos: Los compadres, Redención, Regreso iluminado, Auxilio divino, Alaridos inciertos, Comida mortífera, Terror sonoro, Enemigo feroz, La casona, A la tercera, Uno más, Contratiempo, Paseante del infierno, Doble identidad, Cuidado materno, Diablo honrado, Espantos espantados, Perdidas en el tiempo, Muchacho impío, Pelea fraternal, Negro sonriente, Persecución implacable, San Lucas, Ojo modernísimo, Pronóstico acertado Horror Stories from Old Juan Viñas: El Sitio

  17. El sistema de escuelas primarias de Juan O'Gorman, arquitecto : modernidad y eficiencia


    Bosqued Navarro, Alejandro


    El proceso de proyecto, llevado a cabo por Juan O’Gorman, para proyectar y construir más de veinticinco Escuelas Primarias en el Distrito Federal en menos de seis meses en 1932, necesariamente debió regirse por una metodología que permitiera conseguirlo. Esta investigación plantea la existencia de un método de proyecto que engloba toda la arquitectura de la etapa funcionalista de O’Gorman. Se considera la metodología, denominada en esta tesis Sistema Modular de las Escuelas Primarias, como un...

  18. Historia de una disidencia: memoria y ficción en la obra de Juan Goytisolo


    Checa Vaquero, Diana


    A través de sus novelas más relacionadas con la narrativa del yo Juan Goytisolo participa del debate en torno a la transformación de los géneros literarios. Principalmente lo hace transgrediendo los límites de la identidad mediante las relaciones entre memoria y ficción y explorando las relaciones entre las categorías de autor, de narrador y de personaje, y teniendo en cuenta el inevitable papel del lector y el impacto resultante del texto. La idea de la memoria y la ficción entendidas como p...

  19. Water Scarcity and Degradation in the Rio San Juan Watershed of Northeastern Mexico


    José de Jesús Návar Cháidez


    El agua se ha convertido en un recurso limitante para el desarrollo en la cuenca del río San Juan, el mayor tributario del bajo Río Bravo, del noreste de México. Señales de manejo no sostenible incluyen: la transferencia del agua entre cuencas, la disminución del nivel del agua de los acuíferos, la presencia de caudales mínimos e inexistentes en varios segmentos de los ríos, aumento en los niveles de contaminación, altos consumos per cápita, baja eficiencia en la agricultura, el disturbio de ...

  20. The Teatro Guindalera Project. An Interview with Juan Pastor MilletFernandez


    Mª-Yolanda Fernández-Suárez


    Juan Pastor Millet was born in Alicante in 1943. He has a degree in Drama and did his training with William Layton and Arnold Taraborrelli in Laboratorio T.E.I. Till 1980 he worked as a theatre, cinema and TV actor. As an independent director he has produced plays by both Spanish and foreign contemporary authors, and also by classic ones like Calderón de la Barca, Shakespeare, Cervantes, Molière, Ibsen, Strindberg and Brecht. From 1987 till 2006 he combined his job as a director with his job ...

  1. La doma de un caudillo colombiano: Juan Nepomuceno Moreno, de Casanare

    Directory of Open Access Journals (Sweden)

    Jane M. Rausch


    Full Text Available Ninguna estatua de Juan Napomuceno Moreno se levanta hoy en Bogotá. La mayoría de los colombianos no han oido hablar de él, y probablemente apenas unos cuantos estudiosos puedan identificarlo como un patriota llanero que combatió en las batallas de Boyacá y Carabobo. Sin embargo, no es exagerado decir que, en mayo e 1831, la actuación de este oscuro caudillo de Casanare pudo haber cambiado el curso de la historia colombiana.

  2. Los Mares Interiores. (Libro de Poemas del Académico Juan Mendoza Vega)


    Efraim Otero Ruiz


    (Presentación del libro en la Fundación Santillana para Iberoamérica, Bogotá, Noviembre 23, 2001).

    Ha querido la deferencia del señor  exPresidente Belisario Betancur, Presidente de la Fundación Santillana para lberoamérica, que sea yo quien les presente el libro "Los mares interiores" del médico, periodista y poeta Juan Mendoza Vega. Tarea que acometo con singular afecto, nacido de una amistad que supera ya los 40 años y de una admiraci...

  3. Del pueblo elegido y el maná escondido. La minera en San Juan (Argentina)


    Mirta Alejandra Antonelli


    Este artículo aborda el desastre ambiental provocado en la mina Veladero, que explota la canadiense Barrick Gold, como implosión del núcleo duro del modelo de la megaminería metalífera en Argentina, que ha tenido como «religión y culto» a la cordillerana provincia de San Juan. Se analiza aquí la narrativa promesante que sostienen los discursos dominantes, aquellos que conforman un dispositivo de control de mundos posibles para la generación de creencias, ideas, valores. Desde una perspectiva ...


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    Wilton Barroso*


    Full Text Available Este estudo tem por objetivo uma análise acerca do comportamento libertino1 dos don Juans2 kunderianos. De posse da compreensão do percurso dessa personagem na historiografia literária, objetiva-se uma comparação analítica dessa figura com as composições de Milan Kundera, tendo como centro de observação os seus universos objetivos e subjetivos de onde se acredita, emanam grandes temas vividos pela humanidade nos tempos atuais. PALAVRAS-CHAVE: Donjuanismo; Pós-modernidade; Subjetividade.

  5. La Guerra de las Galias y el poeta español Juan Eduardo Cirlot


    Conde Salazar, Matilde


    Juan Eduardo Cirlot (1916-1972), poeta, musicólogo, ensayista y crítico de arte, es un personaje de extraordinaria erudición de la que hace gala a lo largo de toda su obra. En la obra de este enamorado de las civilizaciones antiguas encontramos abundantes referencias a personajes y hechos, tanto mitólogicos como históricos o literarios, de Grecia y Roma, y muchas de sus composiciones poéticas o bien están dedicadas a algún aspecto o personaje relacionado con el mundo clásico, o aluden a dicho...

  6. The Effect of Saturation on the Slope Sliding in the San Juan de Grijalva Comunity, Chiapas


    Mora-Ortiz R.S.; Rojas-González E.


    A number of slopes that have been stable during many years may fail when an extraordinary rain period occurs. This phenomenon involves not only the lithology, the geometric and the mechanical characteristics of the slope but also the rain-evaporation-infiltration regime of the site. In this paper, the stability of a slope in the comunity of San Juan de Grijalva, Ostuacán, Chiapas (Mexico) that failed during an intense raining period is analyzed. The volume of this slide was over 5 millions of...

  7. Deep-coal-bed methane potential of the San Juan River coal region, southwestern Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, B.S.; Goolsby, S.M.; Tremain, C.M.


    The deepest, highest ranking and probably gassiest coals in the San Juan River coal region of southwestern Colorado are found in the 100 mile (mi) wide San Juan Basin of Colorado and New Mexico. The thickest and most continuous coal beds in the basin are found in the Cretaceous Fruitland Formation. Logs from 231 petroleum exploration drill holes were used to produce the following: a Fruitland Formation isopach, a Pictured Cliffs structure map, Fruitland Formation net coal and net sand isopachs, and Fruitland coal percentage and sand percentage maps. Of the 231 holes, 8 produced natural gas from sandstones in coal bearing zones, 5 were production tested in mixed sandstone and coal intervals (one well had an initial production of 1.6 MMCFGPD), and 5 were drill stem tested in coal bearing zones (one flowed 1 MMCFG in 35 min). The authors calculate 19.7 billion tons of coal are present in the study area. The coals are ranked high-volatile B (hvB) and high-volatile A (hvA) with local upgrading to medium-volatile (mv). Comparing gas contents of Cretaceous Raton Mesa coals to San Juan Basin coals, a gas potential ranging from 72 cubic feet/ton (cu ft/ton) to 514 cu ft/ton exists. The authors estimate a gas resource in the study area ranging from 1.4 to 10.0 trillion cubic feet. The data indicates that gas is present in the coals of the study area. This gas has been produced from sandstones adjacent to the coals and possibly from the coals themselves. Therefore, it might pay to test the Fruitland coals encountered while drilling for deeper targets. With the right economic factors and development of completion techniques for coal bed methane, this gas resource may prove to be important. Data gained from vitrinite reflectance of cuttings, desorption of cuttings, and desorption of conventional cores continue to support the existing evidence that coal bed gas is being generated and trapped in the deeper portion of the San Juan Basin.

  8. [Dr. Juan Ramon Beltran and his contribution to the School of Dentistry]. (United States)

    Zarranz, A


    He was in charge of the course of Legal Dentistry at the School of Dentistry from 1929 through 1932. He prepared the study program for this subject, basing it on the experience he had gained as professor in Legal Medicine at the Faculty of Medical Sciences in Buenos Aires. He published the book "Medicina Legal para la ensenanza de la Odontologia Legal y Social" (1932), and its second edition included an important contribution made by Dr. Juan Ubaldo Carrea, Main Professor of Orthodontics with Legal Dentistry at this school

  9. Cerebro y metáfora en la novela "Pedro Páramo", de Juan Rulfo

    Directory of Open Access Journals (Sweden)



    Full Text Available Se trata de un avance de investigación que aplica la teoría neurolingüística de Omar Parra Rozo para leer y comprender la metáfora en un texto literario. Se toma como objeto de estudio la novela "Pedro Páramo" de Juan Rulfo, específicamente los fragmentos que hablan acerca de la imagen compleja (religión-poder y muerte. El ejercicio de investigación alcanzó a establecer la relación que existe entre imagen- cerebro y metáfora, en el discurso de esta novela.

  10. A morte como elemento cultural mexicano em Pedro Páramo, de Juan Rulfo

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    Ana Paula Cantarelli


    Full Text Available Pedro Páramo (1955, de Juan Rulfo, desde sua publicação tem sido alvo de inúmeros estudos desenvolvidos por pesquisadores de diferentes áreas do conhecimento (história, sociologia, filosofia, etc.. Neste texto, buscou-se elaborar uma proposta de leitura a partir do reconhecimento da morte, símbolo nacional mexicano, como um elemento constituinte da estrutura narrativa desse romance, com a intenção de ampliar o campo de análises já delineado ao redor dessa obra.


    Directory of Open Access Journals (Sweden)



    Full Text Available Entre 1830 y 1835 algunos dirigentes de Mendoza y San Juan, provincias vitivinícolas, trataron de separarse de la República Argentina y regresar a Chile, tal como en la época colonial. Durante más de dos siglos, Mendoza y San Juan fueron parte del Corregimiento de Cuyo del Reino de Chile. Esta situación cambió desde 1776 con la creación del Virreinato del Río de la Plata. Después de la Revolución de 1810, Mendoza y San Juan formaron parte de la República Argentina. Pero algunos años después de la independencia, un grupo descontento con la acción y decisiones del gobierno de Buenos Aires, inició acciones orientadas a la secesión. Este artículo investiga las razones y motivaciones socioeconómicas de este grupoBetween 1830 and 1835 some leaders of Mendoza and San Juan, wine industry oriented provinces, attempted to withdrawal from Argentina Republic, and come back to Chile such as in colonial times. During more than two centuries, Mendoza and San Juan were members of Cuyo Province in Chile's Kingdom. This situation changed since 1776 because the creation of the River Plate Viceroyalty. After Revolution of 1810, Mendoza and San Juan took part of Argentina Republic. But some years after the independence, a group discontented with de action and decision of Buenos Aires government begun the action oriented to secession. This paper explores the socioeconomic reasons and motivation of this group

  12. Modelling hydrothermal venting in volcanic sedimentary basins: Impact on hydrocarbon maturation and paleoclimate (United States)

    Iyer, Karthik; Schmid, Daniel W.; Planke, Sverre; Millett, John


    Vent structures are intimately associated with sill intrusions in sedimentary basins globally and are thought to have been formed contemporaneously due to overpressure generated by gas generation during thermogenic breakdown of kerogen or boiling of water. Methane and other gases generated during this process may have driven catastrophic climate change in the geological past. In this study, we present a 2D FEM/FVM model that accounts for 'explosive' vent formation by fracturing of the host rock based on a case study in the Harstad Basin, offshore Norway. Overpressure generated by gas release during kerogen breakdown in the sill thermal aureole causes fracture formation. Fluid focusing and overpressure migration towards the sill tips results in vent formation after only few tens of years. The size of the vent depends on the region of overpressure accessed by the sill tip. Overpressure migration occurs in self-propagating waves before dissipating at the surface. The amount of methane generated in the system depends on TOC content and also on the type of kerogen present in the host rock. Generated methane moves with the fluids and vents at the surface through a single, large vent structure at the main sill tip matching first-order observations. Violent degassing takes place within the first couple of hundred years and occurs in bursts corresponding to the timing of overpressure waves. The amount of methane vented through a single vent is only a fraction (between 5 and 16%) of the methane generated at depth. Upscaling to the Vøring and Møre Basins, which are a part of the North Atlantic Igneous Province, and using realistic host rock carbon content and kerogen values results in a smaller amount of methane vented than previously estimated for the PETM. Our study, therefore, suggests that the negative carbon isotope excursion (CIE) observed in the fossil record could not have been caused by intrusions within the Vøring and Møre Basins alone and that a contribution

  13. Direct torus venting analysis for Chinshan BWR-4 plant with MARK-I containment

    Energy Technology Data Exchange (ETDEWEB)

    Yuann, Yng-Ruey, E-mail:


    Highlights: • Study the effectiveness of Direct Torus Venting System (DTVS) during extended SBO of 24 h for Chinshan MARK-I plant. • Containment response is analyzed by GOTHIC based on boundary conditions from RETRAN calculation. • Analyses are performed with and without DTVS, respectively. • Suppression pool is sub-divided and thermal stratification is observed. - Abstract: The Chinshan plant, owned by Taiwan Power Company, has twin units of BWR-4 reactor and MARK-I containment. Both units have been operating at rated core thermal power of 1840 MWt. The existing Direct Torus Venting System (DTVS) is the main system used for venting the containment during the extended station blackout event. The purpose of this paper is to study the effects of the DTVS venting on the response of the containment pressure and temperature. The reactor is depressurized by manually opening the safety relief valves (SRVs) during the SBO, which causes the mass and energy to be discharged into and heat up the suppression pool. The RETRAN model is used to calculate the Nuclear Steam Supply System (NSSS) response and generate the SRV blowdown conditions, including SRV pressure, enthalpy, and mass flow rate. These conditions are then used as the time-dependent boundary conditions for the GOTHIC code to calculate the containment pressure and temperature response. The DTVS model is established in the GOTHIC model based on the venting size, venting piping loss, venting initiation time, and venting source. The lumped volume model, 1-D coarse-mesh model, and 3-D coarse-mesh model are considered in the torus volume. The calculation is first done without DTVS venting to establish a reference basis. Then a case with DTVS available is performed. Comparison of the two cases shows that the existing DTVS design is effective in mitigating the severity of the containment pressure and temperature transients. The results also show that the 1-D coarse-mesh model may not be appropriate since a

  14. Hg bioaccumulation in marine copepods around hydrothermal vents and the adjacent marine environment in northeastern Taiwan. (United States)

    Hsiao, Shih-Hui; Fang, Tien-Hsi


    The Hg concentration in seawater and copepod samples collected from the area around hydrothermal vents at Kueishan Island and the adjacent marine environment in northeastern Taiwan were analyzed to study Hg bioaccumulation in copepods living in polluted and clean marine environments. The seawater collected from the hydrothermal vent area had an extremely high concentration of dissolved Hg, 50.6-256 ng l(-1). There was slightly higher Hg content in the copepods, 0.08-0.88 μg g(-1). The dissolved Hg concentration in the hydrothermal vent seawater was two to three orders of magnitude higher than that in the adjacent environment. The bioconcentration factor of the studied copepods ranged within 10(3)-10(6), and showed higher dissolved concentration as the bioconcentration factor was lower. A substantial abundance, but with less copepod diversity was recorded in the seawater around the hydrothermal vent area. Temora turbinata was the species of opportunity under the hydrothermal vent influence. Copyright © 2013. Published by Elsevier Ltd.

  15. Arsenic speciation in food chains from mid-Atlantic hydrothermal vents (United States)

    Taylor, Vivien F.; Jackson, Brian P.; Siegfried, Matthew R.; Navratilova, Jana; Francesconi, Kevin A.; Kirshtein, Julie; Voytek, Mary


    Arsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge hydrothermal vents. The shrimp species, Rimicaris exoculata, the vent chimney-dwelling mussel, Bathymodiolus azoricus, Branchipolynoe seepensis, a commensal worm of B. azoricus and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (δ13C and δ15N) signature between species, suggesting different sources of As uptake. Arsenic speciation showed arsenobetaine to be the dominant species in R. exoculata, whereas in B. azoricus and B. seepensis arsenosugars were most abundant, although arsenobetaine, dimethylarsinate and inorganic arsenic were also observed, along with several unidentified species. Scrape samples from outside the vent chimneys covered with microbial mat, which is a presumed food source for many vent organisms, contained high levels of total As, but organic species were not detectable. The formation of arsenosugars in pelagic environments is typically attributed to marine algae, and the pathway to arsenobetaine is still unknown. The occurrence of arsenosugars and arsenobetaine in these deep sea organisms, where primary production is chemolithoautotrophic and stable isotope analyses indicate food sources are of vent origin, suggests that organic arsenicals can occur in a foodweb without algae or other photosynthetic life.

  16. Bayesian Optimization Analysis of Containment-Venting Operation in a Boiling Water Reactor Severe Accident

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    Xiaoyu Zheng


    Full Text Available Containment venting is one of several essential measures to protect the integrity of the final barrier of a nuclear reactor during severe accidents, by which the uncontrollable release of fission products can be avoided. The authors seek to develop an optimization approach to venting operations, from a simulation-based perspective, using an integrated severe accident code, THALES2/KICHE. The effectiveness of the containment-venting strategies needs to be verified via numerical simulations based on various settings of the venting conditions. The number of iterations, however, needs to be controlled to avoid cumbersome computational burden of integrated codes. Bayesian optimization is an efficient global optimization approach. By using a Gaussian process regression, a surrogate model of the “black-box” code is constructed. It can be updated simultaneously whenever new simulation results are acquired. With predictions via the surrogate model, upcoming locations of the most probable optimum can be revealed. The sampling procedure is adaptive. Compared with the case of pure random searches, the number of code queries is largely reduced for the optimum finding. One typical severe accident scenario of a boiling water reactor is chosen as an example. The research demonstrates the applicability of the Bayesian optimization approach to the design and establishment of containment-venting strategies during severe accidents.

  17. Arsenic speciation in food chains from mid-Atlantic hydrothermal vents. (United States)

    Taylor, Vivien F; Jackson, Brian P; Siegfried, Matthew; Navratilova, Jana; Francesconi, Kevin A; Kirshtein, Julie; Voytek, Mary


    Arsenic concentration and speciation were determined in benthic fauna collected from the Mid-Atlantic Ridge hydrothermal vents. The shrimp species, Rimicaris exoculata , the vent chimney-dwelling mussel, Bathymodiolus azoricus , Branchipolynoe seepensis , a commensal worm of B. azoricus , and the gastropod Peltospira smaragdina showed variations in As concentration and in stable isotope (δ 13 C and δ 15 N) signature between species, suggesting different sources of As uptake. Arsenic speciation showed arsenobetaine to be the dominant species in R. exoculata , whereas in B. azoricus and B. seepensis arsenosugars were most abundant, although arsenobetaine, dimethylarsinate, and inorganic arsenic were also observed, along with several unidentified species. Scrape samples from outside the vent chimneys, covered with microbial mat, which is a presumed food source for many vent organisms, contained high levels of total As, but organic species were not detectable. The formation of arsenosugars in pelagic environments is typically attributed to marine algae, and the pathway to arsenobetaine is still unknown. The occurrence of arsenosugars and arsenobetaine in these deep sea organisms, where primary production is chemolithoautotrophic and stable isotope analyses indicate food sources are of vent origin, suggests that organic arsenicals can occur in a food web without algae or other photosynthetic life.

  18. On the differing growth mechanisms of black-smoker and Lost City-type hydrothermal vents (United States)

    Cardoso, Silvana S. S.; Cartwright, Julyan H. E.


    Black smokers and Lost City-type springs are varieties of hydrothermal vents on the ocean floors that emit hot, acidic water and cool, alkaline water, respectively. While both produce precipitation structures as the issuing fluid encounters oceanic water, Lost City-type hydrothermal vents in particular have been implicated in the origin of life on the Earth. We present a parallel-velocity flow model for the radius and flow rate of a cylindrical jet of fluid that forms the template for the growth of a tube precipitated about itself and we compare the solution with previous laboratory experimental results from growth of silicate chemical gardens. We show that when the growth of the solid structure is determined by thermal diffusion, fluid flow is slow at the solid-liquid contact. However, in the case of chemical diffusive transport, the fluid jet effectively drags the liquid in the pores of the solid precipitate. These findings suggest a continuum in the diffusive growth rate of hydrothermal vent structures, where Lost City-type hydrothermal vents favour contact between the vent fluid and the external seawater. We explore the implications for the road to life.

  19. Astronomical and atmospheric impacts on deep-sea hydrothermal vent invertebrates. (United States)

    Lelièvre, Yann; Legendre, Pierre; Matabos, Marjolaine; Mihály, Steve; Lee, Raymond W; Sarradin, Pierre-Marie; Arango, Claudia P; Sarrazin, Jozée


    Ocean tides and winter surface storms are among the main factors driving the dynamics and spatial structure of marine coastal species, but the understanding of their impact on deep-sea and hydrothermal vent communities is still limited. Multidisciplinary deep-sea observatories offer an essential tool to study behavioural rhythms and interactions between hydrothermal community dynamics and environmental fluctuations. Here, we investigated whether species associated with a Ridgeia piscesae tubeworm vent assemblage respond to local ocean dynamics. By tracking variations in vent macrofaunal abundance at different temporal scales, we provide the first evidence that tides and winter surface storms influence the distribution patterns of mobile and non-symbiotic hydrothermal species (i.e. pycnogonids Sericosura sp. and Polynoidae polychaetes) at more than 2 km depth. Local ocean dynamics affected the mixing between hydrothermal fluid inputs and surrounding seawater, modifying the environmental conditions in vent habitats. We suggest that hydrothermal species respond to these habitat modifications by adjusting their behaviour to ensure optimal living conditions. This behaviour may reflect a specific adaptation of vent species to their highly variable habitat. © 2017 The Author(s).

  20. LH2 tank pressure control by thermodynamic vent system (TVS) at zero gravity (United States)

    Wang, B.; Huang, Y. H.; Chen, Z. C.; Wu, J. Y.; Li, P.; Sun, P. J.


    Thermodynamic vent system (TVS) is employed for pressure control of propellant tanks at zero gravity. An analytical lumped parameter model is developed to predict pressure variation in an 18.09 m3 liquid hydrogen tank equipped with TVS. Mathematical simulations are carried out assuming tank is filled up to 75% volume (liquid mass equals to 945 kg) and is subjected to heat flux of 0.76 W/m2. Tank pressure controls at 165.5-172.4, 165.5-179.3 and 165.5-182.2 kPa are compared with reference to number of vent cycles, vent duration per cycle and loss of hydrogen. Analysis results indicate that the number of vent cycles significantly decreases from 62 to 21 when tank pressure control increases from 6.9 to 20.4 kPa. Also, duration of vent cycle increases from 63 to 152 and cycle duration decreases from 3920 to 3200 s. Further, the analysis result suggests that LH2 evaporation loss per day decreases from 0.17 to 0.14%. Based on the results of analysis, TVS is found effective in controlling the propellant tank pressure in zero gravity.

  1. Oil Heat Vent Analysis Program (OHVAP) users manual and engineering report

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R.F.


    Oil-fired heating appliances have traditionally used conventional chimney venting systems. In more recent times, masonry chimneys have given way to fabricated metal chimneys which have had the advantage of lower installed cost. Even more recently, there has been an effort by the industry to apply power venting technology to oil-fired appliances. These changes in venting technology have been accompanied by ever improving appliance efficiencies. The successful application of these modern, high efficiency oil-fired appliances depends upon the safe and cost effective integration of the heating appliance and the vent system. Unfortunately, due to the complexity inherent in such issues as heat loss, condensation and corrosion the available manual calculations provide only a steady state rather than transient analysis. In addition, these methods are exceedingly cumbersome. While computerized methods have been developed, for the most part they are usually these same steady state calculations placed into a spreadsheet or BASIC program. This report describes the oil heat vent analysis program (OHVAP) for the analysis of ventilation of oil-fired appliances.

  2. Bacterial sulfur cycle shapes microbial communities in surface sediments of an ultramafic hydrothermal vent field

    DEFF Research Database (Denmark)

    Schauer, Regina; Røy, Hans; Augustin, Nico


    RNA sequence analysis, was characterized by the capability to metabolize sulfur components. High sulfate reduction rates as well as sulfide depleted in (34)S further confirmed the importance of the biogeochemical sulfur cycle. In contrast, methane was found to be of minor relevance for microbial life in mat......, these sediments were investigated in order to determine biogeochemical processes and key organisms relevant for primary production. Temperature profiling at two mat-covered sites showed a conductive heating of the sediments. Elemental sulfur was detected in the overlying mat and metal-sulfides in the upper......-covered surface sediments. Our data indicate that in conductively heated surface sediments microbial sulfur cycling is the driving force for bacterial biomass production although ultramafic-hosted systems are characterized by fluids with high levels of dissolved methane and hydrogen....

  3. Leonardo da Vinci’s anatomical drawings and Juan de Arfe y Villafañe

    Directory of Open Access Journals (Sweden)

    Röhrl, Boris


    Full Text Available The four volumes of the Varia commensuración para la escultura y architectura (1585–87 of the Spanish silversmith and sculptor Juan de Arfe y Villafañe represent an extensive compilation of Italian art techniques of the Renaissance. The sources for the Libro segundo, which includes systematic explanations on the theory of proportions, the skeleton and musculature have yet to be discovered. Its didactic and illustrative structure is unique in the context of sixteenth-century literature. The general layout and some details of the illustrations of the first three chapters seem to be derived from the Windsor convolute of anatomical drawings by Leonardo da Vinci.Los cuatros libros de Varia commensuración para la escultura y architectura (1585-1587 del platero y escultor Juan de Arfe y Villafañe representan un extenso compendio de las teorías y técnicas del Renacimiento italiano. Las fuentes del Libro segundo, que contiene explicaciones sistemáticas sobre la proporción de la figura humana, el esqueleto y la musculatura, aún no han sido descubiertas. La estructura didáctica y las ilustraciones son únicas en el contexto de la literatura del siglo XVI. El formato general y algunos detalles de las ilustraciones de los primeros tres capítulos parecen tener su origen en los dibujos anatómicos de Leonardo da Vinci conservados en el castillo de Windsor.

  4. Progressive migration and anagenesis in Drimys confertifolia of the Juan Fernández Archipelago, Chile. (United States)

    López-Sepúlveda, Patricio; Takayama, Koji; Greimler, Josef; Crawford, Daniel J; Peñailillo, Patricio; Baeza, Marcelo; Ruiz, Eduardo; Kohl, Gudrun; Tremetsberger, Karin; Gatica, Alejandro; Letelier, Luis; Novoa, Patricio; Novak, Johannes; Stuessy, Tod F


    A common mode of speciation in oceanic islands is by anagenesis, wherein an immigrant arrives and through time transforms by mutation, recombination, and drift into a morphologically and genetically distinct species, with the new species accumulating a high level of genetic diversity. We investigate speciation in Drimys confertifolia, endemic to the two major islands of the Juan Fernández Archipelago, Chile, to determine genetic consequences of anagenesis, to examine relationships among populations of D. confertifolia and the continental species D. winteri and D. andina, and to test probable migration routes between the major islands. Population genetic analyses were conducted using AFLPs and nuclear microsatellites of 421 individuals from 42 populations from the Juan Fernández islands and the continent. Drimys confertifolia shows a wide genetic variation within populations on both islands, and values of genetic diversity within populations are similar to those found within populations of the continental progenitor. The genetic results are compatible with the hypothesis of high levels of genetic variation accumulating within anagenetically derived species in oceanic islands, and with the concept of little or no geographical partitioning of this variation over the landscape. Analysis of the probability of migration within the archipelago confirms colonization from the older island, Robinson Crusoe, to the younger island Alejandro Selkirk.

  5. Dinosaur Footprints in Lower Cretaceous Beds in San Juan Raya, Southern Mexico and the Paleoenvironmental Implications (United States)

    Aceves, D.


    Dinosaur footprints were traced at San Juan Raya, an important site in Mexico, a world fossil site. This site is found at South-west of the State of Puebla, within the Biosphere Reserve of Tehuacan-Cuitcatlán, to the southwest of the Tehuacan valley. These footprints were recorded by tracing them on transparent paper at Barranca Agua Nueva, at point 18°18.56´N 97°37´W. Using Jacob´s staff a stratigraphic register was generated from 50 m ascending and descending in stratigraphically direction from the bed where footprints were founded. Bivalbes, nerineas, shell fragments, and trigonias were founded in this sequence as well as cross bedding of clays and fine grain sand, some which display ripples. Fifty two footprints were recorded and five different tracks identified, observing two different sizes. The tracks of dinosaur footprints present the common Teropode ichnites. The succession where dinosaur footprints have been found, are interpreted as a peritidal environment. This investigation contributes to an eco-tourism project of San Juan Raya.

  6. La astronomía de un humanista, Juan Andrés

    Directory of Open Access Journals (Sweden)



    Full Text Available RESUMEN: La páginas que siguen pretenden ofrecer una visión de conjunto del análisis que de la historia de la Astronomía realiza Juan Andrés, desde los orígenes de la humanidad hasta el siglo XVIII. Este análisis, incluido en su monumental obra Origen, progresos y estado actual de toda la literatura, destaca por su modernidad y precisión, constituyendo, por tanto, una interesante base de comparación entre la visión de la ciencia astronómica del humanismo ilustrado y la que pervive en la actualidad.ABSTRACT: The following pages attempt to offer a full view of the research into the history of astronomy made by Juan Andrés, from the beginning of human culture until the 18th century. This analysis, included in a broader work called Origen, progresos y estado de toda la literatura, stands out on account of its modern and precise ideas, thus representing an interesting knowledge base for comparing the view of astronomy during the Enlightenment with that of the present.

  7. Climate-driven disturbances in the San Juan River sub-basin of the Colorado River (United States)

    Bennett, Katrina E.; Bohn, Theodore J.; Solander, Kurt; McDowell, Nathan G.; Xu, Chonggang; Vivoni, Enrique; Middleton, Richard S.


    Accelerated climate change and associated forest disturbances in the southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances on the basin scale, and none on the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change on a headwater basin to the Colorado River, the San Juan River watershed, using a robustly calibrated (Nash-Sutcliffe efficiency 0.76) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce evapotranspiration and increase streamflow. In this study, annual average regional streamflow under the coupled climate-disturbance scenarios is at least 6-11 % lower than those scenarios accounting for climate change alone; for forested zones of the San Juan River basin, streamflow is 15-21 % lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbance scenarios indicate a high risk of low water availability for forested headwater systems of the Colorado River basin. These findings also indicate that explicit representation of land cover disturbances is required in modeling efforts that consider the impact of climate change on water resources.

  8. [Hospital San Juan de Dios: actor and victim of the public policies in Colombia]. (United States)

    Pinilla, María Y; Abadía, César E


    In this article, we narrate and analyze the historical configuration that a group of female workers and a collective of social organizations made about the Hospital San Juan de Dios (HSJD) and Instituto Materno Infantil (IMI) in Bogotá, Colombia, within the neoliberal crisis in health. Our ethnographic research intersects the Latinamerican traditions of collaborative ethnography and historic anthropology. The research was conducted in two sites. In the first one, from 2005 until 2015, we had informal conversations and conducted workshops and semi-structured interviews with IMI workers. The second site corresponds to our participation in the deliberations of the Mesa Jurídica por el San Juan de Dios (2008-2009), which aimed to elevate a class action to defend the hospitals. We found that workers and social organizations made use of the colonial origin of the hospitals and their institutionalization as center of welfare policies in the country as a way to highlight their patrimonial, historical, educational and social importance. This historical construction critiques efforts that negate or transform the public character of the hospitals and helped them carry on different actions to denounce the neoliberal health care reform as the cause of the hospitals most important crisis and closing. The different actors denounce the change in the hospitals-state relationship, which transited from being central for the development of social policies to reflecting a symbolic and material elimination of the hospitals. Such transition benefits the market interests established by the neoliberal model.

  9. Juan Rejano en México: Los criterios del crítico literario

    Directory of Open Access Journals (Sweden)

    Olmedo Muñoz, Iliana


    Full Text Available Making use of the articles published by Juan Rejano in El Nacional, this paper defines Rejano’s criteria in order to make known the critical perspective of Spanish exiles about Mexican literature and to insist in the importance of a dialogue between Mexican and Exile intellectuals. Despite the registry of his column is wide, Rejano’s critique about Mexican narrative explains his tastes, his ideas of tradition and literary quality. Moreover, the specific case of Rejano demonstrates how Spanish exiles participated and exerted influence in Mexico’s cultural space.Este trabajo analiza la columna que Juan Rejano mantuvo durante décadas en el diario El Nacional como ejemplo de la crítica literaria que los exiliados españoles realizaron en México, un capítulo importante y poco estudiado del diálogo cultural entre intelectuales exiliados y mexicanos. Aunque el registro de la columna es muy amplio, examinar la labor de Rejano como crítico de narrativa mexicana revela sus filiaciones, su idea de tradición y de calidad literaria. Además descubre, desde el caso concreto de Rejano, cómo los exiliados participaron e influyeron en la conformación del medio cultural mexicano.

  10. A Geo-referenced 3D model of the Juan de Fuca Slab and associated seismicity (United States)

    Blair, J.L.; McCrory, P.A.; Oppenheimer, D.H.; Waldhauser, F.


    We present a Geographic Information System (GIS) of a new 3-dimensional (3D) model of the subducted Juan de Fuca Plate beneath western North America and associated seismicity of the Cascadia subduction system. The geo-referenced 3D model was constructed from weighted control points that integrate depth information from hypocenter locations and regional seismic velocity studies. We used the 3D model to differentiate earthquakes that occur above the Juan de Fuca Plate surface from earthquakes that occur below the plate surface. This GIS project of the Cascadia subduction system supersedes the one previously published by McCrory and others (2006). Our new slab model updates the model with new constraints. The most significant updates to the model include: (1) weighted control points to incorporate spatial uncertainty, (2) an additional gridded slab surface based on the Generic Mapping Tools (GMT) Surface program which constructs surfaces based on splines in tension (see expanded description below), (3) double-differenced hypocenter locations in northern California to better constrain slab location there, and (4) revised slab shape based on new hypocenter profiles that incorporate routine depth uncertainties as well as data from new seismic-reflection and seismic-refraction studies. We also provide a 3D fly-through animation of the model for use as a visualization tool.

  11. Juan de Guevara, poeta y comediógrafo coetáneo de sor Juana

    Directory of Open Access Journals (Sweden)

    Guillermo Schmidhuber de la Mora


    Full Text Available Las vidas y las obras de sor Juana Inés de la Cruz y Juan de guevera tuvieron varios cruces: ganaron premios literarios en el mismo concurso, publicaron juntos y colaboraron en escribir a dos plumas la comedia «Amor es más laberinto». Este ensayo elabora sobre la biografía de este sacerdote y autor, con información desconocida hasta hoy; además, incluye un poema original y de tema universitario inédito The lives and works of sor Juana Inés de la Cruz and Juan Guevera enjoyed several cross paths; they won literary awards at the same contest, published together and collaborated in writing to two pens comedy «Amor es más laberinto». This paper elaborates on the biography of this priest and author, mentioning information unknown until today; a university-milieu poem never publish before.

  12. Climate-driven disturbances in the San Juan River sub-basin of the Colorado River

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, Katrina E.; Bohn, Theodore; Solander, Kurt; McDowell, Nate G.; Xu, Chonggang; Vivoni, Enrique; Middleton, Richard


    Accelerated climate change and associated forest disturbances in the Southwestern USA are anticipated to have substantial impacts on regional water resources. Few studies have quantified the impact of both climate change and land cover disturbances on water balances at the basin scale, and none at the regional scale. In this work, we evaluate the impacts of forest disturbances and climate change for a headwater basin to the Colorado River, the San Juan River watershed, using a robustly-calibrated (Nash Sutcliff 0.80) hydrologic model run with updated formulations that improve estimates of evapotranspiration for semi-arid regions. Our results show that future disturbances will have a substantial impact on streamflow with implications for water resource management. Our findings are in contradiction with conventional thinking that forest disturbances reduce ET and increase streamflow. In this study, annual average regional streamflow under the coupled climate-disturbances scenarios is at least 6–11% lower than those scenarios accounting for climate change alone, and for forested zones of the San Juan River basin streamflow is 15–21% lower. The monthly signals of altered streamflow point to an emergent streamflow pattern related to changes in forests of the disturbed systems. Exacerbated reductions of mean and low flows under disturbance scenarios indicate a high risk of lower water availability for forested headwater systems to the Colorado River basin. These findings also indicate that explicit representation of land cover disturbances is required in modelling efforts that consider the impact of climate change on water resources.

  13. Geologic controls on open-hole cavity completions in the San Juan basin

    Energy Technology Data Exchange (ETDEWEB)

    Kelso, B.S. (Advanced Resources International, Inc., Lakewood, CO (United States))


    The success of open-cavity-completed wells is measured (1) by how well mechanically the cavity is created, which results in a higher degree of completion efficiency; and (2) by production success, whereby production rates are improved relative to other completion techniques. Open-hole cavitation is highly successful in the San Juan basin fairway, but the technique has not been successful in other areas. Outside the fairway, particularly to the south, operators have not achieved mechanical success with cavity completions. To explain the change in permeability across the southern fairway boundary, an hypothesis is proposed that involves the presence of a northwest-trending basement structure, such as a fault or fault zone. Episodic post-Fruitland movement on the northeastern limb of the structure could have enhanced the fracturing of the coal seams, resulting in higher permeabilities and the higher productivity levels of both cavity and fracture-stimulated wells. Based on the San Juan basin data reviewed, it appears that a combination of adequate permeability, overpressuring, and coal rank of high-volatile A bituminous are required for mechanical success of cavity completions. Although the level of permeability is not quantified, it is the author's opinion that at least 5 md is required. High production rates from cavity-completed wells are a function of better completion efficiency, whereby the wellbore is linked to favorable permeability settings. 5 refs., 10 figs.

  14. El destierro infinito de Blanco White en la mirada de Juan Goytisolo

    Directory of Open Access Journals (Sweden)

    Durán López, Fernando


    Full Text Available In the years 1970-1972, the novelist Juan Goytisolo published several studies and translations on the work of José María Blanco White, which represent a key moment in the recovery of that forgotten writer for the modern Spanish culture. The argument made in this essay is that the consciously identifying strategy applied by Goytisolo on Blanco White, in order to define a Spanish intellectual tradition throughout the centuries, marked by exile and dissent, is in fact a deformation of the figure and thought of the writer from Seville. Blanco White’s reception in Spain, however, has been conditioned by that reading.En torno a los años 1970-1972 el novelista Juan Goytisolo publica varios estudios y traducciones sobre la obra de José María Blanco White, que suponen un momento clave en la recuperación de ese olvidado escritor para la moderna cultura española. La tesis formulada en el presente artículo es que la estrategia conscientemente identificadora que aplica Goytisolo sobre Blanco White, a fin de definir una tradición intelectual española a lo largo de los siglos marcada por el exilio y la disidencia, supone de hecho una deformación de la figura y el pensamiento del escritor sevillano. La recepción de Blanco White en España ha quedado, sin embargo, condicionada por esa lectura.

  15. Oil heat venting technology and NFPA standard 31 revision year 2000

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R.F. [Brookhaven National Labs., Upton, NY (United States)


    The revision of National Fire Protection Association (NFPA) Standard 31 for the year 2000 offers an opportunity to update the Appendix which currently offers recommendations for basic metal relining of masonry chimneys up to and including 25 feet. The paper discusses the proposed update of the existing recommendations to include flexible (rough) metal liners. In addition, the discussion addresses the inclusion of additional information for unlined (non-conforming), lined (conforming to NFPA 211) masonary chimneys, insulated metal chimneys, chimney heights beyond what are now published, as well as power venting both forced and induced draft. Included in the paper is a discussion of the existing Oil Heat Vent Analysis Program (OHVAP Version 3.0) and issues that need resolution to make it a better vent system model.

  16. First hydroacoustic evidence of marine, active fluid vents in the Naples Bay continental shelf (Southern Italy) (United States)

    Passaro, Salvatore; Genovese, Simona; Sacchi, Marco; Barra, Marco; Rumolo, Paola; Tamburrino, Stella; Mazzola, Salvatore; Basilone, Gualtiero; Placenti, Francesco; Aronica, Salvatore; Bonanno, Angelo


    We present the first results of a multidisciplinary research aimed at the detection and mapping of Active Fluid Vents (AFVs) at the seafloor of the Naples Bay, Italy. This segment of the Campania continental margin is characterised by severe Quaternary extension and intense volcanism at Ischia and Procida islands, the Campi Flegrei and Somma-Vesuvius volcanic complexes. High resolution hydroacoustic profilers were used to identify and localize fluid emission from the seafloor. ROV direct observation showed that each emission centre is generally composed by the coalescence of several emitting points. CTD probes showed that there are no significant gradients in temperature profiles. The results of this study include the detection and mapping of 54 fluid emission points all located in the - 71/- 158 m depth range, and spatially distributed into four main clusters. Three of the described clusters are located along the margin of a complex, toe-shaped seafloor morphology southwest of the Somma-Vesuvius, representing the shallow expression of partly buried, coalesced depositional features (namely, two flank collapses and one pyroclastic flow) associated with the Late Pleistocene activity of the volcano. The fourth AFV cluster was detected at the morphological - high, located about 8 km south of Naples (Banco della Montagna), represented by a field of volcaniclastic diapirs composed of massive pumiceous deposits originated from the Campi Flegrei intruding rising through the latest Quaternary-Holocene marine deposits. Our study suggests that the occurrence of AFV in this area could be genetically linked to the interaction between volcanic related seafloor morphologies and the main, NE striking faults present in the area, i.e. the Magnaghi-Sebeto line and the Vesuvian fault.

  17. Expanding Geophysical and Geochemical Investigation of Causes of Extraordinary Unrest at the Laguna del Maule (Rhyolitic) Volcanic Field, Southern Andes, Chile (United States)

    Singer, B. S.


    The Laguna del Maule Volcanic Field, Chile, includes an unusually large and recent concentration of silicic eruptions. Since 2007 the crust here has been inflating at an astonishing rate of 25 cm/yr. Findings thus far lead to the hypothesis that the silicic vents have tapped an extensive layer of crystal-poor, rhyolitic melt that began to form atop a magmatic mush zone that was established by ~20 ka with a renewed phase of rhyolite eruptions during the Holocene. Modeling of surface deformation, magnetotelluric data, and gravity changes suggest that magma is currently intruding at a depth of ~5 km. Swarms of volcano-tectonic and long period earthquakes, mostly of M students at: University of Wisconsin-Madison, Georgia Tech, Cornell, University of Alberta, Simon Fraser University, University of Chile-Santiago, CONICET/University of San Juan-Argentina, Nanyang Technological University-Singapore, SERNAGEOMIN, OVDAS, USGS, and SEGEMAR-Argentina. Team members will be introduced in this presentation. Our approach includes augmenting the OVDAS array of 6 permanent seisic stations with 40 additional instruments to conduct tomographic, receiver function and ambient noise studies. We continue to collect 4-D gravity data from 37 stations. Surface deformation is monitored via cGPS at 5 permanent receivers and InSAR data. A magnetotelluric survey across the Andes at 36o S is planned. Geochemical studies include mineral zoning and U-Th disequilibrium of zircons to constrain the timing of magma intrusion and mixing events prior to the current unrest. The overall aim is to integrate these observations and to construct numerical models of system dynamics. We are developing communications protocols and a web site to facilitate sharing of findings among the team members and with the public.

  18. Utilizing ground penetrating radar to image vents and fractures in geothermal ennvironments (United States)

    Dougherty, A. J.; Lynne, B.


    Fractures act as vents allowing gases and thermal water to discharge at the surface from deep geothermal reservoirs. Knowledge of these geothermal environments, and the faults they run along, has been limited to deep geophysics and exposures available by surface mapping. The aim of this research is to display the utility of ground-penetrating radar (GPR) to image vent and fracture pathways within the context of a more comprehensive study into the applicability of this geophysical tool in mapping the shallow subsurface of geothermal areas. GPR transmits short pulses of high-frequency electromagnetic energy into the ground and detects the reflected signals identifying buried objects or boundary surfaces. GPR has been successfully utilized in many geologic settings, including mapping rock fractures, but our research is the first to utilize this geophysical technique in a range of geothermal environments. Hot spring water discharges through vents often along fractures to form siliceous sinter or carbonate travertine hot spring rocks. These vents may self seal overtime, but the sinter or travertine deposit and their geothermal source at depth can be preserved for thousands of years after hot spring discharge ceases. Subsequently these hot spring rocks can become fractured with potential as a gas-migration pathway. Since this formative hot spring water and ascending gases are associated with a deeper geothermal resource, the directionality of these conduits contributes to our understanding of the deeper reservoir. Our initial research in both the United States and New Zealand showed that GPR was successful in imaging sinter and travertine deposits to depths greater than 7 meters with decimetre resolution. Then GPR transects specifically collected over vents and fractures exposed in sinter outcrop showed that the geophysical records compared well with the geological cross-sections. GPR profiles were then collected over open vents, fractures and areas of steaming ground

  19. Synthesis of silver nanoparticles using methanol and dichloromethane extracts of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts. (United States)

    Chitsazi, Mohammad Reza; Korbekandi, Hassan; Asghari, Gholamreza; Bahri Najafi, Rahim; Badii, Akbar; Iravani, Siavash


    The objectives were to study the potential of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts in production of nanoparticles and the effect of the extraction solvent on the produced nanoparticles. Methanol and dichloromethane extracts were prepared by percolation of the plant powder. Both the extracts of P. gnaphalodes (Vent.) Boiss. successfully produced small and polydispersed nanoparticles with low aggregates in early hours of the biotransformation. Methanol extract produced spherical and many single nanoparticles, whereas dichloromethane produced porous polyhedral and more aggregated nanoparticles. Methanol extract of this plant seems to be quiet useful for industrial scale production of nanoparticles.

  20. The mechanics of intermittent methane venting at South Hydrate Ridge inferred from 4D seismic surveying (United States)

    Bangs, Nathan L. B.; Hornbach, Matthew J.; Berndt, Christian


    Sea floor methane vents and seeps direct methane generated by microbial and thermal decompositions of organic matter in sediment into the oceans and atmosphere. Methane vents contribute to ocean acidification, global warming, and providing a long-term (e.g. 500-4000 years; Powell et al., 1998) life-sustaining role for unique chemosynthetic biological communities. However, the role methane vents play in both climate change and chemosynthetic life remains controversial primarily because we do not understand long-term methane flux and the mechanisms that control it ( Milkov et al., 2004; Shakhova et al., 2010; Van Dover, 2000). Vents are inherently dynamic and flux varies greatly in magnitude and even flow direction over short time periods (hours-to-days), often tidally-driven ( Boles et al., 2001; Tryon et al., 1999). But, it remains unclear if flux changes at vents occur on the order of the life-cycle of various species within chemosynthetic communities (months, years, to decades Leifer et al., 2004; Torres et al., 2001) and thus impacts their sustainability. Here, using repeat high-resolution 3D seismic surveys acquired in 2000 and 2008, we demonstrate in 4D that Hydrate Ridge, a vent off the Oregon coast has undergone significant reduction of methane flow and complete interruption in just the past few years. In the subsurface, below a frozen methane hydrate layer, free gas appears to be migrating toward the vent, but currently there is accumulating gas that is unable to reach the seafloor through the gas hydrate layer. At the same time, abundant authigenic carbonates show that the system has been active for several thousands of years. Thus, it is likely that activity has been intermittent because gas hydrates clog the vertical flow pathways feeding the seafloor vent. Back pressure building in the subsurface will ultimately trigger hydrofracturing that will revive fluid-flow to the seafloor. The nature of this mechanism implies regular recurring flow interruptions

  1. 40 CFR Table 5 to Subpart Ppp of... - Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements (United States)


    ... Subpart PPP of Part 63—Process Vents From Batch Unit Operations—Monitoring, Recordkeeping, and Reporting... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 5 Table 5 to Subpart PPP of Part 63...

  2. 40 CFR Table 6 to Subpart Ppp of... - Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements (United States)


    ... Subpart PPP of Part 63—Process Vents From Continuous Unit Operations—Monitoring, Recordkeeping, and... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 6 Table 6 to Subpart PPP of Part 63...

  3. 40 CFR Table 7 to Subpart Ppp of... - Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements (United States)


    ... Subpart PPP of Part 63—Process Vents From Continuous Unit Operations—Monitoring, Recordkeeping, and... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process Vents From Continuous Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 7 Table 7 to Subpart PPP of Part 63...

  4. 40 CFR 63.490 - Batch front-end process vents-performance test methods and procedures to determine compliance. (United States)


    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch front-end process vents... Pollutant Emissions: Group I Polymers and Resins § 63.490 Batch front-end process vents—performance test... interim status requirements of 40 CFR part 265, subpart O. (c) Batch front-end process vent testing and...

  5. 78 FR 15753 - Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants (United States)


    ... COMMISSION Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power... lead-acid storage batteries in nuclear power plants. DATES: Submit comments by May 13, 2013. Comments... Vented Lead-Acid Storage Batteries for Nuclear Power Plants'' is temporarily identified by its task...

  6. 78 FR 58574 - Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants (United States)


    ... COMMISSION Maintenance, Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power..., Testing, and Replacement of Vented Lead-Acid Storage Batteries for Nuclear Power Plants.'' The guide... nuclear power plants. ADDRESSES: Please refer to Docket ID NRC-2013-0048 when contacting the NRC about the...

  7. 46 CFR 153.361 - Arrangements for removal of valves from venting systems having multiple relief valves. (United States)


    ... having multiple relief valves. 153.361 Section 153.361 Shipping COAST GUARD, DEPARTMENT OF HOMELAND... removal of valves from venting systems having multiple relief valves. A venting system having multiple... arranged so that cargo vapor will not escape through the opening left after a valve has been removed. ...

  8. Writing Virtue and Indigenous Rights: Juan Bautista De Pomar and the "Relación de Texcoco" (United States)

    Espericueta, José


    In his "Relación de Texcoco," Juan Bautista de Pomar (c. 1535-90) takes a political and moral stance against Spanish colonialism in Texcoco and the entire viceroyalty of New Spain. Responding to the "Instrucción y memoria's" (1577) request for information about the history and cultural practices of local populations, Pomar…

  9. Variation in the mitochondrial control region in the Juan Fernández fur seal (Arctocephalus philippii). (United States)

    Goldsworthy, S; Francis, J; Boness, D; Fleischer, R


    The Juan Fernandez fur seal (Arctocephalus philippii was allegedly extremely abundant, numbering as many as 4 million prior to sealing which continued from the late 17th to the late 19th century. By the end of the sealing era the species was thought to be extinct until they were rediscovered at Alejandro Selkirk Island in 1965. Historic records would suggest that the species underwent a substantial population bottleneck as a result of commercial sealing, and from population genetic theory we predicted that the genetic variability in the species would be low. We compared the mtDNA control region sequence from 28 Juan Fernandez fur seals from two islands in the Juan Fernandez Archipelago (Chile). Contrary to expectation, we found that variation in the Juan Fernandez fur seals is not greatly reduced in comparison to other pinniped taxa, especially given the apparent severity of the bottleneck they underwent. We also determined minor, but significantly different haplotype frequencies among the populations on the two islands (Alejandro Selkirk and Robinson Crusoe Islands), but no difference in their levels of variability. Such differences may have arisen stochastically via a recent founder event from Alejandro Selkirk to Robinson Crusoe Island or subsequent genetic drift.

  10. AgRISTARS: Renewable resources inventory. Land information support system implementation plan and schedule. [San Juan National Forest pilot test (United States)

    Yao, S. S. (Principal Investigator)


    The planning and scheduling of the use of remote sensing and computer technology to support the land management planning effort at the national forests level are outlined. The task planning and system capability development were reviewed. A user evaluation is presented along with technological transfer methodology. A land management planning pilot test of the San Juan National Forest is discussed.

  11. Kant e o problema da coisa em si no Idealismo Alemão, de Juan Adolfo Bonaccini

    Directory of Open Access Journals (Sweden)

    Glenn W. Erickson


    Full Text Available Resenha do livro "Kant e o problema da coisa em si no Idealismo Alemão: sua atualidade e relevância para a compreensão do problema da Filosofia", de Juan Adolfo Bonaccini. Rio de Janeiro: Relume Dumará, 2003. 442 páginas [Coleção Metafísica 3].

  12. 77 FR 63289 - Foreign-Trade Zone 61-San Juan, PR, Application for Subzone, Coamo Property & Investments, LLC... (United States)


    ... for the facility of Coamo Property & Investments, LLC, located in Coamo, Puerto Rico. The application... Foreign-Trade Zones Board Foreign-Trade Zone 61--San Juan, PR, Application for Subzone, Coamo Property & Investments, LLC, Coamo, PR An application has been submitted to the Foreign-Trade Zones Board (the Board) by...

  13. El mayor laboratorio en física del mundo Juan Antonio Rubio, candidato a dirigir el CERN

    CERN Multimedia


    The spanish Government presented last Friday at the CERN Council Juan Antonio Rubio, as candidate for the post of Director General of CERN. It's the first time that the spanish Government proposes a candidate for the Direction of this international research center. (2/3 page)

  14. 78 FR 34128 - Notice of Inventory Completion: U.S. Department of Agriculture, U.S. Forest Service, San Juan... (United States)


    ... National Park Service Notice of Inventory Completion: U.S. Department of Agriculture, U.S. Forest Service...: The U.S. Department of Agriculture (USDA), Forest Service, San Juan National Forest has completed an... Pueblo of Texas; and the Zuni Tribe of the Zuni Reservation, New Mexico. History and description of the...

  15. 75 FR 70818 - Traffic Separation Schemes: In the Strait of Juan de Fuca and Its Approaches; in Puget Sound and... (United States)


    ... Fuca and Its Approaches; in Puget Sound and Its Approaches; and in Haro Strait, Boundary Pass, and the... Strait of Juan de Fuca and its approaches, in Puget Sound and its approaches, and in Haro Strait... Oceanic and Atmospheric Administration (NOAA) charts since 2006, and are currently documented in the IMO...

  16. Illustration of a fingerprinting method to isolate Gold King Release Metals from Background Concentrations in the San Juan River (United States)

    Detecting the Gold King Mine metals as the release plume passed was difficult once it entered the San Juan River on August 8, 2015. Plume metals concentrations were relatively low after 200 km of travel and deposition in the Animas River while background concentrations of the sa...

  17. Paradiplomacia en las relaciones Chileno-Argentinas : la integración desde Coquimbo y San Juan

    NARCIS (Netherlands)

    Alvarez, M.


    The dissertation studies how non-central governments inserted themselves in the integration process between Argentina and Chile. As a case study, the link between the Argentinean province of San Juan and the Chilean region of Coquimbo was addressed through an extensive literature review and more

  18. 46 CFR 7.145 - Strait of Juan de Fuca, Haro Strait and Strait of Georgia WA. (United States)


    ... Reef Bouy “2”); thence to International Boundary Range B Front Light. Alaska .... (Salmon Bank Lighted Gong Buoy “3”); thence to Cattle Point Light on San Juan Island. (b) A line drawn from Lime Kiln Light to Kellett Bluff Light on Henry Island; thence to Turn Point Light on Stuart...

  19. Investigating a hydrothermal venting scenario at the Bahariya Oasis, Western Desert, Egypt (United States)

    Lupi, Matteo; Mazzini, Adriano; Sciarra, Alessandra; Hammed, Mohammed S.; Schmindt, Susanne T.; Suessenberger, Annette


    but it is a primary phase. Quartz is often rimmed by a phyllosilicate phase of the montmorillonite group, grew probably during the final phases of hydrothermal circulation. We also identified a Zn-Al-F-silicate, that we speculate may be hemimorphite, a typical low-T phase occurring in hydrothermal environments. In addition, zircon, rutile, quartz and microcline are easily recognized and halite, brushite, bornite and diopside are detected by XRD analysis. Considering the textural relationship between the minerals it can be inferred that the Ba-bearing K-feldspar was the first phase to crystallize while the euhedral sanidine grew afterwards. SEM images indicate the textural evidence of channeling implying that high-T fluids were flushing the system and inducing the precipitation of the minerals. The paragenesis and the petrographic structures of the identified mineralogical assemblages indicate circulation of high temperature fluids flushed from these vents towards the surface. This evidence is consistent with large-scale field observations and with a scenario envisaging the paleo-venting system focusing hydrothermal fluids at localities near the faulted zone.

  20. 3D imaging of vents and sand injectites produced by Lower Cretaceous hydrothermal activity in the southern North Sea

    DEFF Research Database (Denmark)

    Moreau, Julien

    for the latest (onlaps on the vents, bended reflections, igneous intrusion dating from well cutting). Vents formation and subsequent fluidized sandstone injection and expulsion are interesting from petroleum exploration perspective. Most of the vents punctured through basins primary source rock – the Posidonia...... shales. The breaching most probably created new pathways for fluid migration, connecting the source with the overlaying sandstone units with sand injectites /fracturation around the pipes. Sand injections in the vents could serve as both migration route and reservoir units, under the condition......Within the Jurassic Broad Forteen Basin (North Sea), 31 vents built of 58 smaller structures have recently been recognized within a seismic cube thanks to seismic attribute analysis. Within the surveyed volume, well cuttings from Zeichstein salt structures contain nephelinic basalts dating of 100...

  1. Robust thumb flexor tendon repairs with a six-strand M-Tang method, pulley venting, and early active motion. (United States)

    Pan, Z J; Qin, J; Zhou, X; Chen, J


    We present the outcomes of flexor pollicis longus tendon repairs in 34 thumbs using a six-strand M-Tang repair with venting of one or two pulleys according to site of tendon laceration. The A2 pulley was vented in all three thumbs with zone 1 injury. In 31 thumbs with zone 2 injuries, the oblique pulley was vented partially or entirely. Twenty-two thumbs had both the A1 and oblique pulleys vented. Six to 46 months post-surgery, 14 thumbs with zone 2 injuries were rated excellent, 13 good, three fair and one failure according to Tang criteria. No tendon ruptures or bowstringing occurred. Fourteen of 34 thumbs had deficits in interphalangeal joint extension averaging 13°. We conclude that venting of one or two pulleys may ensure recovery of thumb function without risking tendon bowstringing and that early active thumb motion is safe with a robust tendon repair. IV.

  2. Estudio de las conductas prosociales en niños de San Juan de Pasto/ Prosocial Behaviors Study in Children San Juan de Pasto

    Directory of Open Access Journals (Sweden)

    Érika Alexandra Vásquez Arteaga


    Full Text Available Objetivo: El presente artículo es el resultado de una investigación finalizada desarrollada en tres escuelas públicas de San Juan de Pasto. El objetivo general se dirigió a develar las manifestaciones de las conductas prosociales de los niños para el diseño e implementación de una estrategia psicopedagógica. Método: La metodología se abordó desde el paradigma cualitativo, con un enfoque crítico social, de tipo investigación-acción. El presente artículo corresponde a la fase hermenéutica de la investigación en donde se emplearon como técnicas de recolección de información: narrativas, entrevistas focalizadas, observaciones participantes y sociodramas. Resultados: Los resultados indicaron que la empatía puede ser vista como una señal de debilidad o como una constante necesaria de interacción; en las conductas de ayuda hay manifestaciones principalmente no altruistas y la cooperación se presenta de manera intermitente según los estímulos ambientales.

  3. Juan Ruiz, Arcipreste de Hita, y Don Juan Manuel, Infante de Castilla : dos miradas para un mundo en crisis o la literatura como herramienta

    Directory of Open Access Journals (Sweden)

    Matías Escalera Cordero


    Full Text Available Hace unos años -en el cuarto número de Verba Hispanica-, en un trabajo titulado Juan Ruiz, un hombre de nuestro tiempo -fundamentado en lo sustancial por las lecturas que del Libro de buen amor, y de la figura de su autor, habían hecho Américo Castro y Jullio Rodríguez Puértolas -, comprobamos cómo la premeditada -y, en absoluto, casualcomplejidad interna del Libro se cimienta no sólo en la diversidad de los materiales que contiene y lo construyen, sino, sobre todo, en la unidad de sentido, que podríamos nombrar proto/novelesca, del conjunto entero: articulada, primero, en tomo de la "ficción realista" -psicológica- del yo literario que los informa; en la lógica –intensamente dialéctica- que los organiza; y, finalmente, en la radical ironía mediante la que el autor desentraña y desactiva todos y cada uno de los -engañosos- discursos artísticos, religiosos e ideológicos dominantes en su tiempo; especialmente, el cortesano, el clerical y el monetario.

  4. Juan C

    African Journals Online (AJOL)

    Information Technology

    justice to the eloquence of the phrasing, formulation, argumentation and structure of this study. The third essay is the thought-provoking one by Blaise Pascal, "The Art of. Persuasion" (pp. 108-117). This essay is particularly interesting as it is one of the few in which definitions are linked to the rhetorical tradition. The rules for.

  5. Juan C

    African Journals Online (AJOL)

    Information Technology

    John Locke, Gottfried Wilhelm Leibniz, George Berkeley, Immanuel Kant, John. Stuart Mill, and Heinrich Rickert have also been included. Although all included texts are classified as "essays", there is some variety in the form in which the authors present their views on definition: besides the essay, there are also genres such ...

  6. Utilisation de l'espace dans la communauté de San Juan

    Directory of Open Access Journals (Sweden)


    Full Text Available Quelques aspects de la mise en valeur et de l'exploitation agro-pastorale du terroir de San Juan sont présentés à l'aide d'une série de cartes et de tableaux: carte de l'intensité de l'utilisation annuelle de la terre, circuit annuel du bétail, système foncier, évolution de l'irrigation au cours de l'année, rotation des cultures à proximité du village, rotation de terres d'altitude, évolution du bétail et enfin systèmes de mise en valeur du sol, on étudie en conclusion deux types d'évolution possibles de ce village. -Una serie de mapas y de cuadros presenta algunos aspectos del manejo y de 1a explotación agropastoral del terruño de la Comunidad de San Juan, teniendo en cuenta las limitaciones naturales ,y socioculturales: mapa de la intensidad del uso anual de la tierra con respecto al riego, rotación del ganado durante el año, sistema predial, evolución del riego a lo largo del año, rotación de los cultivos entre los corrales ubicados cerca del pueblo, rotación de los cultivos en las tierras de altura, evolución del ganado y sistemas de uso del suelo. Se examinan en conclusión dos tipos de evolución posibles para el pueblo. Some aspects of agro-pastoral management and exploitation in the San Juan lands are presented with a series of maps and tables: map of annual land utilization intensity, annual cattle rotation, land tenure system, irrigation process during the year, rotation of crops near the village, rotation of altitude lands, cattle evolution and soil use systems. Finally, two possible types of evolution for this village are discussed.

  7. Geochemistry of reduced fluids from shallow cold vents hosting chemosynthetic communities (Comau Fjord, Chilean Patagonia, ∼42°S) (United States)

    Muñoz, Práxedes; Sellanes, Javier; Villalobos, Katherine; Zapata-Hernández, Germán; Mayr, Christoph; Araya, Karen


    Reduced fluids from shallow-marine vents sustain chemosynthetic bacterial mats located at the base of the volcano Barranco Colorado in Comau Fjord (X-Huinay; 42°23.279‧S, 72°27.635‧W). We characterized the chemical environment in which these bacteria thrive. To this end, we analyzed CH4, ∑H2S, O2, DIC, and stable isotopes (δ13C, δ2H and δ18O) and compared them with readings taken at a control station (which lacks evidence of fluid venting and mat-forming bacteria). In addition, CTD measurements, chlorophyll-a, and nutrient analyses were performed. At depths of approximately 5-7 m, the water column exhibited a pycnocline that formed under the influence of fresh water discharges, especially during the summer season, which also affected the surface temperature. Bacterial mats and elemental sulfur flocs were observed in the vicinity of the vents (X-Huinay station), and higher concentrations of reduced compounds (CH4 and ∑H2S) were found in the vent fluids, in particular at a depth of 36 m. No significant differences in the temperatures of vent and ambient waters were detected. The bottom water close to the vents possessed notably low concentrations of reduced compounds, indicating a rapid and large-quantity dilution of the chemicals from vents. The surface water featured light isotopic values of δ2H and 18O due to the freshwater input from melting ice and precipitation. A linear mixing trend was observed between the freshwater (negative isotopic values) and the fjord bottom water (positive values) that was not influenced by vent fluid. This trend suggests that the venting water corresponds to the mixing among local meteoric water, spring water, and seawater. This result is relevant to understanding how freshwater and meteoric water influence the chemical composition of seawater and how this mixing could impact the marine biota in the vicinities of the vents.

  8. Spatial variation of metal bioaccumulation in the hydrothermal vent mussel Bathymodiolus azoricus


    Cosson, Richard P.; Thiébaut, Éric; Company, Rui; Castrec-Rouelle, Maryse; Colaço, Ana; Martins, Inès; Sarradin, Pierre-Marie; Bebianno, Maria João


    Spatial variation of metal bioaccumulation in the hydrothermal vent mussel Bathymodiolus azoricus correspondance: Corresponding author. (Cosson, Richard P.) (Cosson, Richard P.) Universite de Nantes--> , EMI--> , EA 2663--> , F-44322 Nantes cedex 3--> - FRANCE (Cosson, Richard P.) FRANCE (Cosson, Richard P.) Universite Pierre et Marie Curie-Paris6--> , UMR-CNRS-...

  9. 21 CFR 113.89 - Deviations in processing, venting, or control of critical factors. (United States)


    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Deviations in processing, venting, or control of critical factors. 113.89 Section 113.89 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... critical factors are out of control for any low-acid food or container system as disclosed from records by...

  10. E-njoy the first CERN Global Network e-vent!

    CERN Multimedia

    CERN Bulletin


    Empowered by the considerable interest it received after it was launched, the CERN Global Network takes off and organizes the first e-vent, which will be a special talk on science communication that will be held on 29 June at 4.30 p.m. in the Council Chamber. You can experience it live on the Global Network site and, if you are a Member, provide feedback. Stay linked!   On the CERN Global Network webpage, you will be able to choose the topic of the next e-vents. Seven weeks after its launch, about 600 people have already joined the CERN Global Network and six thematic groups have been created. The whole idea of joining the Network is to stay connected or reconnect with life at CERN where seminars, talks and discussions are undoubtedly a very important and much appreciated part of it. This is where the e-vents come into play. “The e-vents enable members of the Global Network to participate in selected events taking place at CERN, such as lectures or panel discussions. They will...

  11. Compact fluorescent lamp using horizontal and vertical insulating septums and convective venting geometry (United States)

    Siminovitch, Michael


    A novel design for a compact fluorescent lamp, including a lamp geometry which will increase light output and efficacy of the lamp in a base down operating position by providing horizontal and vertical insulating septums positioned in the ballast compartment of the lamp to provide a cooler coldspot. Selective convective venting provides additional cooling of the ballast compartment.


    The Environmental Technology Verification report discusses the technology and performance of a pressure relief valve for protection of storage tanks that operate at pressures of 15 psig or less. Four Pin-Tech Bubble Tight <500 ppm Relief Vent valves manufactured by the Protectose...

  13. Bacterial Sulfate Reduction Above 100-Degrees-C in Deep-Sea Hydrothermal Vent Sediments

    DEFF Research Database (Denmark)



    -reducing bacteria was done in hot deep-sea sediments at the hydrothermal vents of the Guaymas Basin tectonic spreading center in the Gulf of California. Radiotracer studies revealed that sulfate reduction can occur at temperatures up to 110-degrees-C, with an optimum rate at 103-degrees to 106-degrees...

  14. 40 CFR 63.645 - Test methods and procedures for miscellaneous process vents. (United States)


    ... process heater with a design heat input capacity of 44 megawatts or greater. (2) Any boiler or process... site. (2) No traverse site selection method is needed for vents smaller than 0.10 meter in diameter. (f... cubic meter) (kilogram per gram) (minute per day), where the standard temperature (standard cubic meter...

  15. Bonded carbon or ceramic fiber composite filter vent for radioactive waste (United States)

    Brassell, Gilbert W.; Brugger, Ronald P.


    Carbon bonded carbon fiber composites as well as ceramic or carbon bonded ceramic fiber composites are very useful as filters which can separate particulate matter from gas streams entraining the same. These filters have particular application to the filtering of radioactive particles, e.g., they can act as vents for containers of radioactive waste material.

  16. Effect of shallow-water venting in Azores on a few marine biota

    Digital Repository Service at National Institute of Oceanography (India)

    Colaco, A.; Raghukumar, C.; Mohandass, C.; Cardigos, F.; Santos, R.S.

    The 1000 m high D. Joao de Castro seamount lies in the middle of the Azores Archipelago (Portugal) on the hyperslow-spreading Terceira rift in the Atlantic. Hydrothermal vents were found near the top of the seamount and occurred in two distinct...

  17. In Situ Soil Venting - Full Scale Test, Hill AFB. Volume 3. Guidance Document, Literature Review (United States)


    and Hazardous Materials Agency (USATHAMA), operated a pilot-scale soil venting test at a solvent dump site at the Twin Cities Army Ammunitions Plant...even soil heating could remediate a site several times faster than an unheated case, with favorable economia . Based upon a hypothetical regulatory

  18. Prebiotic Synthesis of Glycine from Ethanolamine in Simulated Archean Alkaline Hydrothermal Vents (United States)

    Zhang, Xianlong; Tian, Ge; Gao, Jing; Han, Mei; Su, Rui; Wang, Yanxiang; Feng, Shouhua


    Submarine hydrothermal vents are generally considered as the likely habitats for the origin and evolution of early life on Earth. In recent years, a novel hydrothermal system in Archean subseafloor has been proposed. In this model, highly alkaline and high temperature hydrothermal fluids were generated in basalt-hosted hydrothermal vents, where H2 and CO2 could be abundantly provided. These extreme conditions could have played an irreplaceable role in the early evolution of life. Nevertheless, sufficient information has not yet been obtained for the abiotic synthesis of amino acids, which are indispensable components of life, at high temperature and alkaline condition. This study aims to propose a new method for the synthesis of glycine in simulated Archean submarine alkaline vent systems. We investigated the formation of glycine from ethanolamine under conditions of high temperature (80-160 °C) and highly alkaline solutions (pH = 9.70). Experiments were performed in an anaerobic environment under mild pressure (0.1-8.0 MPa) at the same time. The results suggested that the formation of glycine from ethanolamine occurred rapidly and efficiently in the presence of metal powders, and was favored by high temperatures and high pressures. The experiment provides a new pathway for prebiotic glycine formation and points out the phenomenal influence of high-temperature alkaline hydrothermal vents in origin of life in the early ocean.

  19. 40 CFR 270.24 - Specific part B information requirements for process vents. (United States)


    ... calculations or source tests. For the purpose of determining compliance, estimates of vent emissions and... highest load or capacity level reasonably expected to occur. (3) Information and data used to determine... applies for permission to use a control device other than a thermal vapor incinerator, catalytic vapor...

  20. Passive soil venting at the Chemical Waste Landfill Site at Sandia National Laboratories, Albuquerque, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Phelan, J.M.; Reavis, B.; Cheng, W.C.


    Passive Soil Vapor Extraction was tested at the Chemical Waste Landfill (CWL) site at Sandia National Laboratories, New Mexico (SNLIW). Data collected included ambient pressures, differential pressures between soil gas and ambient air, gas flow rates into and out of the soil and concentrations of volatile organic compounds (VOCS) in vented soil gas. From the differential pressure and flow rate data, estimates of permeability were arrived at and compared with estimates from other studies. Flow, differential pressure, and ambient pressure data were collected for nearly 30 days. VOC data were collected for two six-hour periods during this time. Total VOC emissions were calculated and found to be under the limit set by the Resource Conservation and Recovery Act (RCRA). Although a complete process evaluation is not possible with the data gathered, some of the necessary information for designing a passive venting process was determined and the important parameters for designing the process were indicated. More study is required to evaluate long-term VOC removal using passive venting and to establish total remediation costs when passive venting is used as a polishing process following active soil vapor extraction.