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Sample records for chimney venting tables

  1. The application of masonry chimney venting tables for oil-fired appliances

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R.F.; Strasser, J. [Brookhaven National Lab., Upton, NY (United States)

    1995-04-01

    This paper presents an overview of the results of work in developing a set of rational guidelines for the venting of modern oil-fired appliances. The activities included the continued development and completion of the Oil-Heat Vent Analysis Program (OHVAP), Version 1.0 and the interpretation of nearly 2,000 runs in preparing recommendations for presentation in table form. These results are presented in the form of venting tables for the installation of chimney vent systems for mid- and high-efficiency oil-fired heating appliances using masonry chimneys. A brief description of OHVAP is given as well as a discussion of what the program does. Recommendations based on the results of OHVAP are presented in the form of five tables spanning oil-fired appliance Steady state Efficiencies (Eff{sub ss}) of 80% to 88%. The assumptions used in the calculations and examples of the computed results are presented as well as a discussion of the rationale for masonry chimney system treatment. Working examples are given with suggested diagnostic approaches for application of the table recommendations.

  2. Development of a practical training program based on BNL`s input to new NFPA Lined Masonary Chimney Venting Tables

    Energy Technology Data Exchange (ETDEWEB)

    Potter, G. [Agway Energy Products, Tully, NJ (United States)

    1997-09-01

    This paper describes how we developed a practical training program for technicians and sales personnel from the BNL studies that evolved into the Lined Chimney Venting Tables. One of the topics discussed is our search for solutions to the reoccurring problems associated with flue gas condensation on newly installed oil fired appliances. The paper will also discuss our own experiences in applying the new venting tables and working through the questions that arise when we encounter installations beyond the scope of the present tables.

  3. Modeling microbial reaction rates in a submarine hydrothermal vent chimney wall

    NARCIS (Netherlands)

    LaRowe, D.E.; Dale, A.W.; Aguilera, D.R.; L'Heureux, I.; Amend, J.P.; Regnier, P.

    2014-01-01

    The fluids emanating from active submarine hydrothermal vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several mod

  4. Modeling microbial reaction rates in a submarine hydrothermal vent chimney wall

    Science.gov (United States)

    LaRowe, Douglas E.; Dale, Andrew W.; Aguilera, David R.; L'Heureux, Ivan; Amend, Jan P.; Regnier, Pierre

    2014-01-01

    The fluids emanating from active submarine hydrothermal vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, hydrothermal fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these hydrothermal systems. In an effort to remedy this, a fully coupled biogeochemical reaction-transport model of a hydrothermal vent chimney has been developed that explicitly quantifies the rates of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation-reduction reactions associated with fluid mixing as a function of temperature. The metabolisms included in the reaction network are methanogenesis, aerobic oxidation of hydrogen, sulfide and methane and sulfate reduction by hydrogen and methane. Model results indicate that microbial catalysis is generally fastest in the hottest habitable portion of the vent chimney (77-102 °C), and methane and sulfide oxidation peak near the seawater-side of the chimney. The fastest metabolisms are aerobic oxidation of H2 and sulfide and reduction of sulfate by H2 with maximum rates of 140, 900 and 800 pmol cm-3 d-1, respectively. The maximum rate of hydrogenotrophic methanogenesis is just under 0.03 pmol cm-3 d-1, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). These simulations are consistent with vent chimney metabolic activity inferred from phylogenetic data reported in the literature. The model developed here provides a quantitative approach to describing the rates of biogeochemical transformations in hydrothermal systems and can be used to constrain the

  5. Quantifying metabolic rates in submarine hydrothermal vent chimneys: A reaction transport model

    Science.gov (United States)

    LaRowe, D.; Dale, A.; Aguilera, D.; Amend, J. P.; Regnier, P.

    2012-12-01

    The fluids emanating from active submarine hydrothermal vent chimneys provide a window into subseafloor processes and, through mixing with seawater, are responsible for steep thermal and compositional gradients that provide the energetic basis for diverse biological communities. Although several models have been developed to better understand the dynamic interplay of seawater, hydrothermal fluid, minerals and microorganisms inside chimney walls, none provide a fully integrated approach to quantifying the biogeochemistry of these hydrothermal systems. In an effort to remedy this, a fully coupled biogeochemical reaction transport model of a hydrothermal vent chimney has been developed that explicitly quantifies the rate of microbial catalysis while taking into account geochemical processes such as fluid flow, solute transport and oxidation-reduction reactions associated with fluid mixing as a function of temperature. Methanogenesis, hydrogen oxidation by oxygen and sulfate, sulfide oxidation by oxygen and methane oxidation by oxygen and sulfate are the metabolisms included in the reaction network. Model results indicate that microbial catalysis is fastest in the hottest habitable portion of the vent chimney except for methane oxidation by oxygen, which peaks near the seawater-side of the chimney at 20 nmol /cm^3 yr. The dominant metabolisms in the chimney are hydrogen oxidation by sulfate and oxygen and sulfide oxidation at peak rates 3200 , 300 and 900 nmol /cm^3 yr, respectively. The maximum rate of hydrogenotrophic methanogensis is just under 0.07 nmol /cm^3 yr, the slowest of the metabolisms considered. Due to thermodynamic inhibition, there is no anaerobic oxidation of methane by sulfate (AOM). The model developed here provides a quantitative approach to understanding the rates of biogeochemical transformations in hydrothermal systems and can be used to better understand the role of microbial activity in the deep subsurface.

  6. Assessing the influence of physical, geochemical and biological factors on anaerobic microbial primary productivity within hydrothermal vent chimneys.

    Science.gov (United States)

    Olins, H C; Rogers, D R; Frank, K L; Vidoudez, C; Girguis, P R

    2013-05-01

    Chemosynthetic primary production supports hydrothermal vent ecosystems, but the extent of that productivity and its governing factors have not been well constrained. To better understand anaerobic primary production within massive vent deposits, we conducted a series of incubations at 4, 25, 50 and 90 °C using aggregates recovered from hydrothermal vent structures. We documented in situ geochemistry, measured autochthonous organic carbon stable isotope ratios and assessed microbial community composition and functional gene abundances in three hydrothermal vent chimney structures from Middle Valley on the Juan de Fuca Ridge. Carbon fixation rates were greatest at lower temperatures and were comparable among chimneys. Stable isotope ratios of autochthonous organic carbon were consistent with the Calvin-Benson-Bassham cycle being the predominant mode of carbon fixation for all three chimneys. Chimneys exhibited marked differences in vent fluid geochemistry and microbial community composition, with structures being differentially dominated by gamma (γ) or epsilon (ε) proteobacteria. Similarly, qPCR analyses of functional genes representing different carbon fixation pathways showed striking differences in gene abundance among chimney structures. Carbon fixation rates showed no obvious correlation with observed in situ vent fluid geochemistry, community composition or functional gene abundance. Together, these data reveal that (i) net anaerobic carbon fixation rates among these chimneys are elevated at lower temperatures, (ii) clear differences in community composition and gene abundance exist among chimney structures, and (iii) tremendous spatial heterogeneity within these environments likely confounds efforts to relate the observed rates to in situ microbial and geochemical factors. We also posit that microbes typically thought to be mesophiles are likely active and growing at cooler temperatures, and that their activity at these temperatures comprises the

  7. Assessing the influence of physical, geochemical and biological factors on anaerobic microbial primary productivity within hydrothermal vent chimneys.

    Science.gov (United States)

    Olins, H C; Rogers, D R; Frank, K L; Vidoudez, C; Girguis, P R

    2013-05-01

    Chemosynthetic primary production supports hydrothermal vent ecosystems, but the extent of that productivity and its governing factors have not been well constrained. To better understand anaerobic primary production within massive vent deposits, we conducted a series of incubations at 4, 25, 50 and 90 °C using aggregates recovered from hydrothermal vent structures. We documented in situ geochemistry, measured autochthonous organic carbon stable isotope ratios and assessed microbial community composition and functional gene abundances in three hydrothermal vent chimney structures from Middle Valley on the Juan de Fuca Ridge. Carbon fixation rates were greatest at lower temperatures and were comparable among chimneys. Stable isotope ratios of autochthonous organic carbon were consistent with the Calvin-Benson-Bassham cycle being the predominant mode of carbon fixation for all three chimneys. Chimneys exhibited marked differences in vent fluid geochemistry and microbial community composition, with structures being differentially dominated by gamma (γ) or epsilon (ε) proteobacteria. Similarly, qPCR analyses of functional genes representing different carbon fixation pathways showed striking differences in gene abundance among chimney structures. Carbon fixation rates showed no obvious correlation with observed in situ vent fluid geochemistry, community composition or functional gene abundance. Together, these data reveal that (i) net anaerobic carbon fixation rates among these chimneys are elevated at lower temperatures, (ii) clear differences in community composition and gene abundance exist among chimney structures, and (iii) tremendous spatial heterogeneity within these environments likely confounds efforts to relate the observed rates to in situ microbial and geochemical factors. We also posit that microbes typically thought to be mesophiles are likely active and growing at cooler temperatures, and that their activity at these temperatures comprises the

  8. Microbial life associated with low-temperature hydrothermal venting and formation of barite chimneys at Loki's Castle vent field

    Science.gov (United States)

    Thorseth, I. H.; Steen, I.; Roalkvam, I.; Dahle, H.; Stokke, R.; Rapp, H.; Pedersen, R.

    2010-12-01

    A low-temperature diffuse venting area with numbers of small barite chimneys is located on the flank of the large sulphide mound of the Loki’s Castle black smoker vent field at the Arctic Mid-Ocean Ridge (AMOR). White cotton-like microbial mats on top of the barite chimneys and associated siboglinid tubeworms were observed. The temperature was determined to 20°C for the surface sediment and 0°C for the white microbial mats, just above the ambient bottom seawater temperature of -0.8°C. The microbial mats were sampled using a remote operating vehicle (ROV) equipped with a hydraulic sampling cylinder (biosyringe) and the chimneys using an aluminum scuffle box. Black colored interior flow channels surrounded by white outer sections of nearly pure barite, were observed. Scanning electron microscopy (SEM) of mats showed numerous microbial cells and large amounts of extracellular thread-like material with attached barite crystals. Inside the chimneys microbial cells are partially embedded in barite, and individual crystals are also frequently covered by extracellular material. The microbial activity could thus have an important influence on the nucleation and growth of the barite crystals and thus on the formation of the chimneys. To reveal the microbial community structure, 16S rRNA gene sequence tag-encoded pyrosequencing (1.1 x 104 - 3.5 x 104 amplicons per library) followed by taxonomic classification of the reads using the MEGAN software, were performed. Organisms assigned to a genus of sulfide oxidizers (Sulfurimonas) within the e-Proteobacteria were abundant in each chimney structure; the white microbial mats (86-96% of the reads), the white barite (36% of total reads); the black flow channel (9.9%). The second most dominating taxon in the white chimney barite, including 26% of the reads, was anaerobic methanotrophs (ANME) of the ANME-1 clade, indicating anaerobic methane oxidation (AOM) as a major microbial process. Furthermore, the novel AOM associated clade

  9. Microbial Primary Productivity in Hydrothermal Vent Chimneys at Middle Valley, Juan de Fuca Ridge

    Science.gov (United States)

    Olins, H. C.; Rogers, D.; Frank, K. L.; Girguis, P. R.; Vidoudez, C.

    2012-12-01

    Chemosynthetic primary productivity supports hydrothermal vent ecosystems, but the extent of that productivity has not been well measured. To examine the role that environmental temperature plays in controlling carbon fixation rates, and to assess the degree to which microbial community composition, in situ geochemistry, and mineralogy influence carbon fixation, we conducted a series of shipboard incubations across a range of temperatures (4, 25, 50 and 90°C) and at environmentally relevant geochemical conditions using material recovered from three hydrothermal vent chimneys in the Middle Valley hydrothermal vent field (Juan de Fuca Ridge). Net rates of carbon fixation (CFX) were greatest at lower temperatures, and were similar among structures. Rates did not correlate with the mineralogy or the geochemical composition of the high temperature fluids at each chimney. No obvious patterns of association were observed between carbon fixation rates and microbial community composition. Abundance of selected functional genes related to different carbon fixation pathway exhibited striking differences among the three study sites, but did not correlate with rates. Natural carbon isotope ratios implicate the Calvin Benson Bassham Cycle as the dominant mechanism of primary production in these systems, despite the abundance of genes related to other pathways (and presumably some degree of activity). Together these data reveal that primary productivity by endolithic communities does not exhibit much variation among these chimneys, and further reveal that microbial activity cannot easily be related to mineralogical and geochemical assessments that are made at a coarser scale. Indeed, the relationships between carbon fixation rates and community composition/functional gene abundance were also likely obfuscated by differences in scale at which these measurements were made. Regardless, these data reveal the degree to which endolithic, anaerobic carbon fixation contributes to

  10. Biosignatures in chimney structures and sediment from the Loki's Castle low-temperature hydrothermal vent field at the Arctic Mid-Ocean Ridge.

    Science.gov (United States)

    Jaeschke, Andrea; Eickmann, Benjamin; Lang, Susan Q; Bernasconi, Stefano M; Strauss, Harald; Früh-Green, Gretchen L

    2014-05-01

    We investigated microbial life preserved in a hydrothermally inactive silica–barite chimney in comparison with an active barite chimney and sediment from the Loki's Castle low-temperature venting area at the Arctic Mid-Ocean Ridge (AMOR) using lipid biomarkers. Carbon and sulfur isotopes were used to constrain possible metabolic pathways. Multiple sulfur (dδ34S, Δ33S) isotopes on barite over a cross section of the extinct chimney range between 21.1 and 22.5 % in δ34S, and between 0.020 and 0.034 % in Δ33S, indicating direct precipitation from seawater. Biomarker distributions within two discrete zones of this silica–barite chimney indicate a considerable difference in abundance and diversity of microorganisms from the chimney exterior to the interior. Lipids in the active and inactive chimney barite and sediment were dominated by a range of 13C-depleted unsaturated and branched fatty acids with δ13C values between -39.7 and -26.7 %, indicating the presence of sulfur-oxidizing and sulfate-reducing bacteria. The majority of lipids (99.5 %) in the extinct chimney interior that experienced high temperatures were of archaeal origin. Unusual glycerol monoalkyl glycerol tetraethers (GMGT) with 0–4 rings were the dominant compounds suggesting the presence of mainly (hyper-) thermophilic archaea. Isoprenoid hydrocarbons with δ13C values as low as -46 % also indicated the presence of methanogens and possibly methanotrophs.

  11. Impact of the Colonization by Paralvinella sulfincola on the Microbial Diversity Associated with a Deep-Sea Hydrothermal Vent Sulfide Chimney (Axial Seamount, Juan de Fuca Ridge)

    Science.gov (United States)

    Page, A.; Juniper, K.; Olagnon, M.; Alain, K.; Desrosiers, G.; Querellou, J.; Cambon-Bonavita, M.

    2002-12-01

    In the early stages of high temperature deep-sea hydrothermal vent chimneys growth, the walls remain porous and allow the escape of hydrothermal fluids as well as an inflow of seawater. This gradual mixing creates sharp thermal and geochemical gradients and provides potential habitats for physiologically diverse microorganisms. The annelid polychaete Paralvinella sulfincola colonizes the external surfaces of these structures, covering them with layered mucous tubes that locally alter the mixing of discharged hydrothermal fluids and surrounding seawater. Modifications of the physical and chemical conditions combined with an accumulation of elemental sulfur (S0) in P. sulfincola mucous tube are thought to be responsible for the deposition of a thin marcassite (FeS2) crust on outer surfaces of anhydrite chimneys (Juniper et al. 1992). This marcassite deposition could partly be induced by a shift in the composition of microbial communities that would to be locally associated with the presence of P. sulfincola. To test this hypothesis, we evaluated the impact of the colonization by P. sulfincola on the microbial communities present at the surface of an active sulfide chimney. Bacterial and archaeal 16S rRNA genes were amplified from DNA extracted from a P. sulfincola tube and from a chimney mineral sample. Using the statistical analysis demonstrated by Singleton et al. (2001), both clone libraries from the chimney sample have been shown to be significantly different from those of the P. sulfincola tube sample, even though the major phylogenetic groups of these libraries were similar. As it has been observed at other deep-sea hydrothermal vent sites, the Epsilon-Proteobacteria and the Deep-sea Hydrothermal Vent Euryarchaeotic Group 1 were the dominant components of both bacterial and archaeal clone libraries. These results seem to indicate that P. sulfincola affect the microbial community composition on high temperature chimneys.

  12. 40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and Reporting Requirements 7 Table 7 to Subpart JJJ... Table 7 to Subpart JJJ of Part 63—Group 1 Batch Process Vents and Aggregate Batch Vent...

  13. Novel barite chimneys at the Loki´s Castle Vent Field shed light on key factors shaping microbial communities and functions in hydrothermal systems

    Directory of Open Access Journals (Sweden)

    Ida Helene eSteen

    2016-01-01

    Full Text Available In order to fully understand the cycling of elements in hydrothermal systems it is critical to understand intra-field variations in geochemical and microbiological processes in both focused, high-temperature and diffuse, low-temperature areas. To reveal important causes and effects of this variation, we performed an extensive chemical and microbiological characterization of a low-temperature venting area in the Loki’s Castle Vent Field (LCVF. This area, located at the flank of the large sulfide mound, is characterized by numerous chimney-like barite (BaSO4 structures (≤ 1m high covered with white cotton-like microbial mats. Results from geochemical analyses, microscopy (FISH, SEM, 16S rRNA gene amplicon-sequencing and metatranscriptomics were compared to results from previous analyses of biofilms growing on black smoker chimneys at LCVF. Based on our results, we constructed a conceptual model involving the geochemistry and microbiology in the LCVF. The model suggests that CH4 and H2S are important electron donors for microorganisms in both high-temperature and low-temperature areas, whereas the utilization of H2 seems restricted to high-temperature areas. This further implies that sub-seafloor processes can affect energy-landscapes, elemental cycling, and the metabolic activity of primary producers on the seafloor. In the cotton-like microbial mats on top of the active barite chimneys, a unique network of single cells of Epsilonproteobacteria interconnected by threads of extracellular polymeric substances (EPS was seen, differing significantly from the long filamentous Sulfurovum filaments observed in biofilms on the black smokers. This network also induced nucleation of barite crystals and is suggested to play an essential role in the formation of the microbial mats and the chimneys. Furthermore, it illustrates variations in how different genera of Epsilonproteobacteria colonize and position cells in different vent fluid mixing zones within

  14. Novel Barite Chimneys at the Loki's Castle Vent Field Shed Light on Key Factors Shaping Microbial Communities and Functions in Hydrothermal Systems.

    Science.gov (United States)

    Steen, Ida H; Dahle, Håkon; Stokke, Runar; Roalkvam, Irene; Daae, Frida-Lise; Rapp, Hans Tore; Pedersen, Rolf B; Thorseth, Ingunn H

    2015-01-01

    In order to fully understand the cycling of elements in hydrothermal systems it is critical to understand intra-field variations in geochemical and microbiological processes in both focused, high-temperature and diffuse, low-temperature areas. To reveal important causes and effects of this variation, we performed an extensive chemical and microbiological characterization of a low-temperature venting area in the Loki's Castle Vent Field (LCVF). This area, located at the flank of the large sulfide mound, is characterized by numerous chimney-like barite (BaSO4) structures (≤ 1 m high) covered with white cotton-like microbial mats. Results from geochemical analyses, microscopy (FISH, SEM), 16S rRNA gene amplicon-sequencing and metatranscriptomics were compared to results from previous analyses of biofilms growing on black smoker chimneys at LCVF. Based on our results, we constructed a conceptual model involving the geochemistry and microbiology in the LCVF. The model suggests that CH4 and H2S are important electron donors for microorganisms in both high-temperature and low-temperature areas, whereas the utilization of H2 seems restricted to high-temperature areas. This further implies that sub-seafloor processes can affect energy-landscapes, elemental cycling, and the metabolic activity of primary producers on the seafloor. In the cotton-like microbial mats on top of the active barite chimneys, a unique network of single cells of Epsilonproteobacteria interconnected by threads of extracellular polymeric substances (EPS) was seen, differing significantly from the long filamentous Sulfurovum filaments observed in biofilms on the black smokers. This network also induced nucleation of barite crystals and is suggested to play an essential role in the formation of the microbial mats and the chimneys. Furthermore, it illustrates variations in how different genera of Epsilonproteobacteria colonize and position cells in different vent fluid mixing zones within a vent field

  15. 40 CFR Table 3 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Continuous Process Vents

    Science.gov (United States)

    2010-07-01

    ... Requirements for Continuous Process Vents 3 Table 3 to Subpart VVVVVV of Part 63 Protection of Environment... of Part 63—Emission Limits and Compliance Requirements for Continuous Process Vents As required in § 63.11496, you must comply with the requirements for continuous process vents as shown in...

  16. 40 CFR Table 2 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Batch Process Vents

    Science.gov (United States)

    2010-07-01

    ... Requirements for Batch Process Vents 2 Table 2 to Subpart VVVVVV of Part 63 Protection of Environment... of Part 63—Emission Limits and Compliance Requirements for Batch Process Vents As required in § 63.11496, you must comply with the requirements for batch process vents as shown in the following...

  17. 40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and Reporting Requirements 6 Table 6 to... 6 to Subpart U of Part 63—Group 1 Batch Front-End Process Vents and Aggregate Batch Vent...

  18. Magnetite formation from ferrihydrite by hyperthermophilic archaea from Endeavour Segment, Juan de Fuca Ridge hydrothermal vent chimneys.

    Science.gov (United States)

    Lin, T Jennifer; Breves, E A; Dyar, M D; Ver Eecke, H C; Jamieson, J W; Holden, J F

    2014-05-01

    Hyperthermophilic iron reducers are common in hydrothermal chimneys found along the Endeavour Segment in the northeastern Pacific Ocean based on culture-dependent estimates. However, information on the availability of Fe(III) (oxyhydr) oxides within these chimneys, the types of Fe(III) (oxyhydr) oxides utilized by the organisms, rates and environmental constraints of hyperthermophilic iron reduction, and mineral end products is needed to determine their biogeochemical significance and are addressed in this study. Thin-section petrography on the interior of a hydrothermal chimney from the Dante edifice at Endeavour showed a thin coat of Fe(III) (oxyhydr) oxide associated with amorphous silica on the exposed outer surfaces of pyrrhotite, sphalerite, and chalcopyrite in pore spaces, along with anhydrite precipitation in the pores that is indicative of seawater ingress. The iron sulfide minerals were likely oxidized to Fe(III) (oxyhydr) oxide with increasing pH and Eh due to cooling and seawater exposure, providing reactants for bioreduction. Culture-dependent estimates of hyperthermophilic iron reducer abundances in this sample were 1740 and 10 cells per gram (dry weight) of material from the outer surface and the marcasite-sphalerite-rich interior, respectively. Two hyperthermophilic iron reducers, Hyperthermus sp. Ro04 and Pyrodictium sp. Su06, were isolated from other active hydrothermal chimneys on the Endeavour Segment. Strain Ro04 is a neutrophilic (pH opt 7-8) heterotroph, while strain Su06 is a mildly acidophilic (pH opt 5), hydrogenotrophic autotroph, both with optimal growth temperatures of 90-92 °C. Mössbauer spectroscopy of the iron oxides before and after growth demonstrated that both organisms form nanophase (hydrothermal systems that are mildly acidic where mineral weathering at increased temperatures occurs. PMID:24612368

  19. 40 CFR Table 1 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for Existing Source Nonhalogenated and Halogenated Vent Streams 1 Table 1 to Subpart... for Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table...

  20. 40 CFR Table 1 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Continuous Process Vents

    Science.gov (United States)

    2010-07-01

    ... Standards for Continuous Process Vents 1 Table 1 to Subpart FFFF of Part 63 Protection of Environment...—Emission Limits and Work Practice Standards for Continuous Process Vents As required in § 63.2455, you must... continuous process vents: For each . . . For which . . . Then you must . . . 1. Group 1 continuous...

  1. 40 CFR Table 4 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Metal HAP Process Vents

    Science.gov (United States)

    2010-07-01

    ... 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...

  2. 40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

    Science.gov (United States)

    2010-07-01

    ... Standards for Batch Process Vents 2 Table 2 to Subpart FFFF of Part 63 Protection of Environment...—Emission Limits and Work Practice Standards for Batch Process Vents As required in § 63.2460, you must meet... process vents: For each . . . Then you must . . . And you must . . . 1. Process with Group 1 batch...

  3. 40 CFR Table 2 to Subpart G of... - Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Process Vents-Coefficients for Total Resource Effectiveness for New Source Nonhalogenated and Halogenated Vent Streams 2 Table 2 to Subpart G of... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 2 Table 2...

  4. Development of the lined masonry chimney oil appliance

    Energy Technology Data Exchange (ETDEWEB)

    Krajewski, R.; Strasser, J. [Brookhaven National Lab., Upton, NY (United States)

    1996-07-01

    This paper describes the development of the lined masonry chimney venting tables form the output of the Oil Heat Analysis Program 9OHVAP. These new tables are different from the prior format, offered in the Proceedings of the 1995 Oil Heat Technology Conference and Workshop, paper No. 95-4. Issues expressed by representatives of the oil heat industry at last years conference during the Venting Technology Workshop resulted in subsequent discussions. A full day meeting was held, co-sponsored by BNL and the Oilheat Manufacturers Association (OMA), to address revision of the format of the venting tables prior to submission to the National Fire Protection Association (NFPA) Standard 31 Technical Committee. The resulting tables and text were submitted to NFPA during the first week of October, 1995. Since then minor changes were made reflecting the addition of data obtained by including intermediate firing rates (0.4, 0.65, and 0.85 gph) not included in the original tables which were developed in increments of 0.25 gph. The new tables address the specific question; {open_quotes}If remediation is required, what is the recommendation for the sizing of a metal liner and the appropriate firing rate range to be used with that liner?{close_quotes}

  5. Sulfurovum aggregans sp. nov., a hydrogen-oxidizing, thiosulfate-reducing chemolithoautotroph within the Epsilonproteobacteria isolated from a deep-sea hydrothermal vent chimney, and an emended description of the genus Sulfurovum.

    Science.gov (United States)

    Mino, Sayaka; Kudo, Hideaki; Arai, Takayuki; Sawabe, Tomoo; Takai, Ken; Nakagawa, Satoshi

    2014-09-01

    A novel mesophilic, strictly hydrogen-oxidizing, sulfur-, nitrate- and thiosulfate-reducing bacterium, designated strain Monchim33(T), was isolated from a deep-sea hydrothermal vent chimney at the Central Indian Ridge. The non-motile, rod-shaped cells were Gram-stain-negative and non-sporulating. Growth was observed between 15 and 37 °C (optimum 33 °C; 3.2 h doubling time) and between pH 5.4 and 8.6 (optimum pH 6.0). The isolate was a strictly anaerobic chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. The G+C content of the genomic DNA was 42.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the novel isolate belonged to the genus Sulfurovum and was closely related to Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum 42BK(T) (95.6 and 95.4 % similarity, respectively). DNA-DNA hybridization demonstrated that the novel isolate could be differentiated genotypically from Sulfurovum sp. NBC37-1 and Sulfurovum lithotrophicum. On the basis of the molecular and physiological traits of the new isolate, the name Sulfurovum aggregans sp. nov. is proposed, with the type strain Monchim33(T) ( = JCM 19824(T) = DSM 27205(T)).

  6. Linkages between mineralogy, fluid chemistry, and microbial communities within hydrothermal chimneys from the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

    Lin, T. J.; Ver Eecke, H. C.; Breves, E. A.; Dyar, M. D.; Jamieson, J. W.; Hannington, M. D.; Dahle, H.; Bishop, J. L.; Lane, M. D.; Butterfield, D. A.; Kelley, D. S.; Lilley, M. D.; Baross, J. A.; Holden, J. F.

    2016-02-01

    Rock and fluid samples were collected from three hydrothermal chimneys at the Endeavour Segment, Juan de Fuca Ridge to evaluate linkages among mineralogy, fluid chemistry, and microbial community composition within the chimneys. Mössbauer, midinfrared thermal emission, and visible-near infrared spectroscopies were utilized for the first time to characterize vent mineralogy, in addition to thin-section petrography, X-ray diffraction, and elemental analyses. A 282°C venting chimney from the Bastille edifice was composed primarily of sulfide minerals such as chalcopyrite, marcasite, and sphalerite. In contrast, samples from a 300°C venting chimney from the Dante edifice and a 321°C venting chimney from the Hot Harold edifice contained a high abundance of the sulfate mineral anhydrite. Geochemical modeling of mixed vent fluids suggested the oxic-anoxic transition zone was above 100°C at all three vents, and that the thermodynamic energy available for autotrophic microbial redox reactions favored aerobic sulfide and methane oxidation. As predicted, microbes within the Dante and Hot Harold chimneys were most closely related to mesophilic and thermophilic aerobes of the Betaproteobacteria and Gammaproteobacteria and sulfide-oxidizing autotrophic Epsilonproteobacteria. However, most of the microbes within the Bastille chimney were most closely related to mesophilic and thermophilic anaerobes of the Deltaproteobacteria, especially sulfate reducers, and anaerobic hyperthermophilic archaea. The predominance of anaerobes in the Bastille chimney indicated that other environmental factors promote anoxic conditions. Possibilities include the maturity or fluid flow characteristics of the chimney, abiotic Fe2+ and S2- oxidation in the vent fluids, or O2 depletion by aerobic respiration on the chimney outer wall.

  7. Metagenome reveals potential microbial degradation of hydrocarbon coupled with sulfate reduction in an oil-immersed chimney from Guaymas Basin

    Directory of Open Access Journals (Sweden)

    Ying eHe

    2013-06-01

    Full Text Available Deep-sea hydrothermal vent chimneys contain a high diversity of microorganisms, yet the metabolic activity and the ecological functions of the microbial communities remain largely unexplored. In this study, a metagenomic approach was applied to characterize the metabolic potential in a Guaymas hydrothermal vent chimney and to conduct comparative genomic analysis among a variety of environments with sequenced metagenomes. Complete clustering of functional gene categories with a comparative metagenomic approach showed that this Guaymas chimney metagenome was clustered most closely with a chimney metagenome from Juan de Fuca. All chimney samples were enriched with genes involved in recombination and repair, chemotaxis and flagellar assembly, highlighting their roles in coping with the fluctuating extreme deep-sea environments. A high proportion of transposases was observed in all the metagenomes from deep-sea chimneys, supporting the previous hypothesis that horizontal gene transfer may be common in the deep-sea vent chimney biosphere. In the Guaymas chimney metagenome, thermophilic sulfate reducing microorganisms including bacteria and archaea were found predominant, and genes coding for the degradation of refractory organic compounds such as cellulose, lipid, pullullan, as well as a few hydrocarbons including toluene, ethylbenzene and o-xylene were identified. Therefore, this oil-immersed chimney supported a thermophilic microbial community capable of oxidizing a range of hydrocarbons that served as electron donors for sulphate reduction under anaerobic conditions.

  8. Fairy chimneys in Peru

    CERN Document Server

    Sparavigna, Amelia Carolina

    2011-01-01

    Erosion creates beautiful landscapes. A large part of them is known just by the local population. Google Maps can help in locating the places, study them and start any project for preservation. An interesting example is given by a landscape of fairy chimneys in Peru, near San Pedro de Larcay. It is remarkable the fact that some of them have been adapted as dwelling places.

  9. Toward a Heat Recovery Chimney

    Directory of Open Access Journals (Sweden)

    Min Pan

    2011-11-01

    Full Text Available The worldwide population increase and subsequent surge in energy demand leads electricity producers to increase supply in an attempt to generate larger profit margins. However, with Global Climate Change becoming a greater focus in engineering, it is critical for energy to be converted in as environmentally benign a way as possible. There are different sustainable methods to meet the energy demand. However, the focus of this research is in the area of Waste Heat Recovery. The waste heat stored in the exiting condenser cooling water is delivered to the air flow through a water-air cross flow heat exchanger. A converging thermal chimney structure is then applied to increase the velocity of the airflow. The accelerated air can be used to turn on the turbine-generator installed on the top the thermal chimney so that electricity can be generated. This system is effective in generating electricity from otherwise wasted heat.

  10. 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)

    1997-09-01

    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.

  11. Psychology and photography: chimneys dreaming and chimneys warriors

    Directory of Open Access Journals (Sweden)

    Tilde Giani Gallino

    2013-02-01

    Full Text Available The article covers two aspects related to Psychology and Art. The first aspect concerns the similarities found between photography and various Schools of experimental psychology. For instance, the scientists of Psychology of ethological theory, and Non-verbal communication (NVC, observe with particular methodologies the non-verbal messages that animals and humans transmit to their peers through expressions, posture, gestures. The same is done by photographers (those who use the “camera” with a good knowledge of the medium and a “photographic  eye” when they look around, careful to catch an expression, any unusual attitude, or a gesture of friendship. Another School of psychology, the Gestalpsychologie (Gestalt: form, figure, configuration, attributes a decisive value to the perception of space, the foreground and the background, the perspective and vanishing points, the contrast between black and white. All aspects that effectively interest psychologists just as much as photographers. Finally, the second aspect relates to the art of Antony Gaudì and makes some hypothesis about the personality and behavior of the great architect, with regard to the construction of two houses, "Casa Batllo" and "Casa Mila": particularly because of the configuration or Gestalt of the "chimneys" that dominate the two buildings. In this study, cooperate each other psychological analysis and the art of photography. The last enables us to study also the details of the work of Gaudì, as can be seen in the pictures of this essay.

  12. Evaluation of corrosion attack of chimney liners

    OpenAIRE

    Blahetová M.; Horák J.; Kubesa P.; Lasek S.; Ochodek T.

    2016-01-01

    The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241) was particularly high content of halides (chlorides and fluorides), which caused a severe pitting corrosion, w...

  13. Evidence for Hydrothermal Vents as "Biogeobatteries" (Invited)

    Science.gov (United States)

    Nielsen, M. E.; Girguis, P. R.

    2010-12-01

    Hydrothermal vents are unique systems that play an important role in oceanic biogeochemical cycles. As chemically reduced hydrothermal fluid mixes with cold oxic seawater, minerals precipitate out of solution resulting in chimney structures composed largely of metal sulfides and anhydrite. Pyrite, which is a natural semi-conductor, is the primary sulfide mineral, but other minerals within chimneys are also conductive (e.g. chalcopyrite, wurtzite, and some iron oxides). Sulfide chimneys are also known to host an extensive endolithic microbial community. Accordingly, submarine hydrothermal systems appear to be examples of biogeobatteries, wherein conductive mineral assemblages span naturally occuring redox gradients and enable anaerobic microbes to access oxygen as an oxidant via extracellular electron transfer (or EET). To test this hypothesis, we ran a series of electrochemical laboratory experiments in which pyrite was used as an anode (in a vessel flushed with hydrothermal-like fluid). When placed in continuity with a carbon fiber cathode, pyrite was found to accept and conduct electrons from both abiotic and biological processes (microbial EET). Specifically, electrical current increased 4-fold (5 nA/m2 to 20 nA/m2) in response to inoculation with a slurry prepared from a hydrothermal vent sample. Inspection of the pyrite anode with SEM revealed ubiquitous coverage by microbes. DNA was extracted from the anodes and the inoculum, and was subjected to pyrosequencing to examine prokaryotic diversity. These data suggest that key microbial phylotypes were enriched upon the pyrite, implicating them in EET. In addition, we deployed an in situ experiment based on microbial fuel cell architecture with a graphite anode inserted into a vent wall coupled to a carbon fiber cathode outside the vent. We observed current production over the course of one year, implying microbial EET in situ. Via pyrosequencing, we observed that the microbial community on the anode was

  14. Toy models for the falling chimney

    CERN Document Server

    Varieschi, G U; Varieschi, Gabriele; Kamiya, Kaoru

    2003-01-01

    In this paper we review the theory of the ``falling chimney'', which deals with the breaking in mid-air of tall structures, when they fall to the ground. We show that these ruptures can be caused by either shear forces, typically developing near the base, or by the bending of the structure, which is caused primarily by the internal bending moment. In the latter case the breaking is more likely to occur between one third and one half of the height of the chimney. Small scale toy models are used to reproduce the dynamics of the falling chimney. By examining photos taken during the fall of these models we test the adequacy of the outlined theory. This type of experiment, easy to perform and conceptually challenging, can become part of a rotational mechanics lab for undergraduate students.

  15. Geology, sulfide geochemistry and supercritical venting at the Beebe Hydrothermal Vent Field, Cayman Trough

    Science.gov (United States)

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

    2015-09-01

    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.

  16. Rapid growth of mineral deposits at artificial seafloor hydrothermal vents.

    Science.gov (United States)

    Nozaki, Tatsuo; Ishibashi, Jun-Ichiro; Shimada, Kazuhiko; Nagase, Toshiro; Takaya, Yutaro; Kato, Yasuhiro; Kawagucci, Shinsuke; Watsuji, Tomoo; Shibuya, Takazo; Yamada, Ryoichi; Saruhashi, Tomokazu; Kyo, Masanori; Takai, Ken

    2016-01-01

    Seafloor massive sulphide deposits are potential resources for base and precious metals (Cu-Pb-Zn ± Ag ± Au), but difficulties in estimating precise reserves and assessing environmental impacts hinder exploration and commercial mining. Here, we report petrological and geochemical properties of sulphide chimneys less than 2 years old that formed where scientific boreholes vented hydrothermal fluids in the Iheya-North field, Okinawa Trough, in East China Sea. One of these infant chimneys, dominated by Cu-Pb-Zn-rich sulphide minerals, grew a height of 15 m within 25 months. Portions of infant chimneys are dominated by sulphate minerals. Some infant chimneys are sulphide-rich similar to high-grade Cu-Pb-Zn bodies on land, albeit with relatively low As and Sb concentrations. The high growth rate reaching the 15 m height within 25 months is attributed to the large hydrothermal vent more than 50 cm in diameter created by the borehole, which induced slow mixing with the ambient seawater and enhanced efficiency of sulphide deposition. These observations suggest the possibility of cultivating seafloor sulphide deposits and even controlling their growth and grades through manipulations of how to mix and quench hydrothermal fluids with the ambient seawater. PMID:26911272

  17. Catalytic Diversity in Alkaline Hydrothermal Vent Systems on Ocean Worlds

    Science.gov (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

    2016-10-01

    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

  18. Biogeochemical insights into microbe-mineral-fluid interactions in hydrothermal chimneys using enrichment culture.

    Science.gov (United States)

    Callac, Nolwenn; Rouxel, Olivier; Lesongeur, Françoise; Liorzou, Céline; Bollinger, Claire; Pignet, Patricia; Chéron, Sandrine; Fouquet, Yves; Rommevaux-Jestin, Céline; Godfroy, Anne

    2015-05-01

    Active hydrothermal chimneys host diverse microbial communities exhibiting various metabolisms including those involved in various biogeochemical cycles. To investigate microbe-mineral-fluid interactions in hydrothermal chimney and the driver of microbial diversity, a cultural approach using a gas-lift bioreactor was chosen. An enrichment culture was performed using crushed active chimney sample as inoculum and diluted hydrothermal fluid from the same vent as culture medium. Daily sampling provided time-series access to active microbial diversity and medium composition. Active archaeal and bacterial communities consisted mainly of sulfur, sulfate and iron reducers and hydrogen oxidizers with the detection of Thermococcus, Archaeoglobus, Geoglobus, Sulfurimonas and Thermotoga sequences. The simultaneous presence of active Geoglobus sp. and Archaeoglobus sp. argues against competition for available carbon sources and electron donors between sulfate and iron reducers at high temperature. This approach allowed the cultivation of microbial populations that were under-represented in the initial environmental sample. The microbial communities are heterogeneously distributed within the gas-lift bioreactor; it is unlikely that bulk mineralogy or fluid chemistry is the drivers of microbial community structure. Instead, we propose that micro-environmental niche characteristics, created by the interaction between the mineral grains and the fluid chemistry, are the main drivers of microbial diversity in natural systems.

  19. Optical Detection of Organic Chemical Biosignatures at Hydrothermal Vents

    Science.gov (United States)

    Conrad, P. G.; Lane, A. L.; Bhartia, R.; Hug, W. H.

    2004-01-01

    We have developed a non-contact, optical life detection instrument that can detect organic chemical biosignatures in a number of different environments, including dry land, shallow aqueous, deep marine or in ice. Hence, the instrument is appropriate as a biosignature survey tool both for Mars exploration or in situ experiments in an ice-covered ocean such as one might wish to explore on Europa. Here, we report the results we obtained on an expedition aboard the Russian oceanographic vessel Akademik Mstislav Keldysh to hydrothermal vent sites in the Pacific Ocean using our life detection instrument MCDUVE, a multichannel, deep ultraviolet excitation fluorescence detector. MCDUVE detected organic material distribution on rocks near the vent, as well as direct detection of organisms, both microbial and microscopic. We also were able to detect organic material issuing directly from vent chimneys, measure the organic signature of the water column as we ascended, and passively observe the emission of light directly from some vents.

  20. Biogeochemistry of Hydrothermal Chimney Environments: Continuous-Flow Experiments at in situ Temperature and Pressure

    Science.gov (United States)

    Houghton, J.; Seyfried, W.; Reysenbach, A.; Banta, A.; von Damm, K.

    2002-12-01

    Recent interest in the existence of a subsurface microbial biosphere at hydrothermal vents has resulted in a plethora of new questions that might best be answered using interdisciplinary techniques that combine geochemistry, microbial ecology, and molecular biology. Ideally, such studies will quantitatively address issues concerning what organisms exist in the subsurface, what metabolisms are sustained in the hydrothermal environment, and what effects these active organisms might have on the nearby fluid and rock. We present a new experimental approach to studying these questions that enables monitoring of an active hydrothermal community of microbes in the presence of chimney material at in situ temperature and pressure. This apparatus is designed as a continuous-flow reactor from which fluid samples can be extracted during the course of the experiment to measure chemistry and biomass, and at the termination of an experiment solids can be extracted for analysis of mineralogical changes and microbial identification. Results of a series of experiments conducted using hydrothermal chimney material (solids and microbial community) collected from 21° N and 9° N East Pacific Rise are presented. At 70° C, a seawater-based fluid with additional NO3-, CO2(aq), and H2(aq) was reacted with chimney material from L vent, 9° N EPR. The fluid lost significant NO3-, PO43-, and gained SO42- even after accounting for the contribution from anhydrite dissolution. No significant sulfide or iron was observed in the fluid. Analysis of the DNA extracted from the solids at the termination of the experiment using partial 16S-rRNA sequence data revealed that the dominant bacteria were S-oxidizing tube worm endosymbionts, a S/NO3- reducing member of the Deferribacter genus, and a H2-oxidizing/NO3- reducing strain of Aquifex. Mineral analysis from before and after the experiment indicates the loss of pyrrhotite (FeS) and anhydrite (CaSO4), and the gain of an Fe-oxide phase tentatively

  1. 40 CFR Table 4 to Subpart G of... - Process Vents-Monitoring, Recordkeeping, and Reporting Requirements For Maintaining a TRE Index...

    Science.gov (United States)

    2010-07-01

    ..., and Reporting Requirements For Maintaining a TRE Index Value >1.0 and. â¤4.0 4 Table 4 to Subpart G of... TRE Index Value >1.0 and. ≤4.0 Final recovery device Parameters to be monitored a Recordkeeping and... for Organic Hazardous Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry...

  2. U-Th systematics and 230Th ages of carbonate chimneys at the Lost City Hydrothermal Field

    Science.gov (United States)

    Ludwig, Kristin A.; Shen, Chuan-Chou; Kelley, Deborah S.; Cheng, Hai; Edwards, R. Lawrence

    2011-04-01

    The Lost City Hydrothermal Field (LCHF) is a serpentinite-hosted vent field located 15 km west of the spreading axis of the Mid-Atlantic Ridge. In this study, uranium-thorium (U-Th) geochronological techniques have been used to examine the U-Th systematics of hydrothermal fluids and the 230Th ages of hydrothermally-precipitated carbonate chimneys at the LCHF. Fluid sample analyses indicate that endmember fluids likely contain only 0.0073 ng/g U or less compared to 3.28 ± 0.03 ng/g of U in ambient seawater. For fluid samples containing only 2-21% ambient seawater (1.1-11 mmol/kg Mg), Th concentration is 0.11-0.13 pg/g and surrounding seawater concentrations average 0.133 ± 0.016 pg/g. The 230Th/ 232Th atomic ratios of the vent fluids range from 1 (±10) × 10 -6 to 11 (±5) × 10 -6, are less than those of seawater, and indicate that the vent fluids may contribute a minor amount of non-radiogenic 230Th to the LCHF carbonate chimney deposits. Chimney 238U concentrations range from 1 to 10 μg/g and the average chimney corrected initial δ 234U is 147.2 ± 0.8, which is not significantly different from the ambient seawater value of 146.5 ± 0.6. Carbonate 232Th concentrations range broadly from 0.0038 ± 0.0003 to 125 ± 16 ng/g and 230Th/ 232Th atomic ratios vary from near seawater values of 43 (±8) × 10 -6 up to 530 (±25) × 10 -3. Chimney ages, corrected for initial 230Th, range from 17 ± 6 yrs to 120 ± 13 kyrs. The youngest chimneys are at the intersection of two active, steeply-dipping normal faults that cut the Atlantis Massif; the oldest chimneys are located in the southwest portion of the field. Vent deposits on a steep, fault-bounded wall on the east side of the field are all <4 kyrs old, indicating that mass wasting in this region is relatively recent. Comparison of results to prior age-dating investigations of submarine hydrothermal systems shows that the LCHF is the most long-lived hydrothermal system known to date. It is likely that seismic

  3. Evaluation of corrosion attack of chimney liners

    Directory of Open Access Journals (Sweden)

    Blahetová M.

    2016-06-01

    Full Text Available The case study of chimney liner corrosion addresses three specific cases of damage of chimney systems from of stainless steels. These systems were used for flue of gas arising from the combustion of brown coal in small automatic boilers, which are used for heating. Detailed analyzes implied that the cause of devastating corrosion of the steel AISI 316 and 304 steel (CSN 17349, 17241 was particularly high content of halides (chlorides and fluorides, which caused a severe pitting corrosion, which led up to the perforation of the liner material. Simultaneous reduction of the thickness of the used sheets was due to by the general corrosion, which was caused by the sulfur in the solid fuel. The condensation then led to acid environment and therefore the corrosion below the dew point of the sulfuric acid has occurred. All is documented by metallographic analysis and microanalysis of the corrosion products.

  4. Volcano Vents

    Science.gov (United States)

    2003-01-01

    [figure removed for brevity, see original site] Released 5 May 2003This low-relief shield volcano imaged with the THEMIS visible camera has two large vents which have erupted several individual lava flows. The positions of the origins of many of the flows indicate that it is probable that the vents are secondary structures that formed only after the shield was built up by eruptions from a central caldera.Image information: VIS instrument. Latitude 17.6, Longitude 243.6 East (116.4 West). 19 meter/pixel resolution.Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  5. Mackinawite and greigite in ancient alkaline hydrothermal chimneys: Identifying potential key catalysts for emergent life

    Science.gov (United States)

    White, Lauren M.; Bhartia, Rohit; Stucky, Galen D.; Kanik, Isik; Russell, Michael J.

    2015-11-01

    One model for the emergence of life posits that ancient, low temperature, submarine alkaline hydrothermal vents, partly composed of iron-sulfides, were capable of catalyzing the synthesis of prebiotic organic molecules from CO2, H2 and CH4. Specifically, hydrothermal mackinawite (FeIIS) and greigite (FeIIFeIII2S4) have been highlighted in previous studies as analogs of the active centers of hydrogenase, ferredoxin, acetyl coenzyme-A synthase and carbon monoxide dehydrogenase featured in the biochemistry of certain autotrophic prokaryotes that occupy the base of the evolutionary tree. Despite the proposed importance of iron sulfide minerals and clusters in the synthesis of abiotic organic molecules, the mechanisms for the formation of these sulfides from solution and their preservation under the anoxic and low temperature (below 100 °C) conditions expected in off-axis submarine alkaline vent systems is not well understood (Bourdoiseau et al., 2011; Rickard and Luther, 2007). To rectify this, single hydrothermal chimneys were precipitated using a unique apparatus to simulate growth at hydrothermal vents of moderate temperature under supposed Hadean ocean-bottom conditions. Iron sulfide phases were observed through Raman spectroscopy at growth temperatures ranging from 40° to 80 °C. Fe(III)-containing mackinawite is confirmed to be present with mackinawite and greigite, supporting an FeIII-mackinawite intermediate mechanism for the transformation of mackinawite to greigite below 100 °C. Raman spectroscopy of the chimneys revealed a maximum yield of greigite at 75 °C. These results suggest abiotic production of catalytically active mackinawite and greigite are possible under early Earth hydrothermal conditions as well as on other wet, rocky worlds geochemically similar to the Earth.

  6. Metagenome and Metatranscriptome Revealed a Highly Active and Intensive Sulfur Cycle in an Oil-Immersed Hydrothermal Chimney in Guaymas Basin.

    Science.gov (United States)

    He, Ying; Feng, Xiaoyuan; Fang, Jing; Zhang, Yu; Xiao, Xiang

    2015-01-01

    The hydrothermal vent system is a typical chemosynthetic ecosystem in which microorganisms play essential roles in the geobiochemical cycling. Although it has been well-recognized that the inorganic sulfur compounds are abundant and actively converted through chemosynthetic pathways, the sulfur budget in a hydrothermal vent is poorly characterized due to the complexity of microbial sulfur cycling resulting from the numerous parties involved in the processes. In this study, we performed an integrated metagenomic and metatranscriptomic analysis on a chimney sample from Guaymas Basin to achieve a comprehensive study of each sulfur metabolic pathway and its hosting microorganisms and constructed the microbial sulfur cycle that occurs in the site. Our results clearly illustrated the stratified sulfur oxidation and sulfate reduction at the chimney wall. Besides, sulfur metabolizing is closely interacting with carbon cycles, especially the hydrocarbon degradation process in Guaymas Basin. This work supports that the internal sulfur cycling is intensive and the net sulfur budget is low in the hydrothermal ecosystem.

  7. Abundances of Hyperthermophilic Autotrophic Fe(III) Oxide Reducers and Heterotrophs in Hydrothermal Sulfide Chimneys of the Northeastern Pacific Ocean ▿ †

    OpenAIRE

    Ver Eecke, Helene C.; Kelley, Deborah S.; Holden, James F.

    2008-01-01

    The abundances of hyperthermophilic heterotrophs, methanogens, and autotrophic reducers of amorphous Fe(III) oxide in 18 samples of deep-sea hydrothermal vent sulfide chimneys of the Endeavour Segment were measured. The results indicate that conditions favor the growth of iron reducers toward the interiors of these deposits and that of heterotrophs toward the outer surfaces near high-temperature polychaete worms (Paralvinella sulfincola).

  8. Abundances of Hyperthermophilic Autotrophic Fe(III) Oxide Reducers and Heterotrophs in Hydrothermal Sulfide Chimneys of the Northeastern Pacific Ocean ▿ †

    Science.gov (United States)

    Ver Eecke, Helene C.; Kelley, Deborah S.; Holden, James F.

    2009-01-01

    The abundances of hyperthermophilic heterotrophs, methanogens, and autotrophic reducers of amorphous Fe(III) oxide in 18 samples of deep-sea hydrothermal vent sulfide chimneys of the Endeavour Segment were measured. The results indicate that conditions favor the growth of iron reducers toward the interiors of these deposits and that of heterotrophs toward the outer surfaces near high-temperature polychaete worms (Paralvinella sulfincola). PMID:18978076

  9. Design manual for HANARO in-chimney bracket

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Cho, Y. G.; Whang, S. Y.; Wu, J. S.; Jun, B. J

    2000-06-01

    As a supplementary structure supporting the irradiation facilities, the in-chimney bracket holds guide tubes whose holding position in CT or IR is the middle part of the instrumented facility between the hole spider and the robot arm already provided in the reactor pool liner. Also, the bracket grips the upper part of the guide tubes when it is applied to hold the instrumented facility loaded in OR sites. The irradiation test will be successfully conducted since this bracket reduces the flow-induced vibration (FIV) and the dynamic response to seismic load. The installation position of the bracket is 60 cm below the top of the chimney, i.e., thermo siphoning hole position. To evaluate the structural integrity on the in-chimney bracket and the related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response analyses were performed for the in-chimney bracket and the related reactor structures of HANARO under the design earthquake response spectrum loads of OBE and SSE. The analysis results show that the stress values in main points of reactor structures and in-chimney bracket for the seismic loads are also within the ASME code limits. It is also confirmed that the fatigue usage factor is much less than 1.0. Therefore any damage on structural integrity is not expected when the in-chimney bracket is installed at the upper part of the reactor chimney. This bracket had been designed and manufactured based on the dimensions of the as-built chimney. In the process of design and preliminary installation, chimney measurement tools, dummy chimney, and installation tools were developed and the installation procedure was prepared and verified through the installation rehearsal.

  10. 40 CFR 63.2455 - What requirements must I meet for continuous process vents?

    Science.gov (United States)

    2010-07-01

    ... continuous process vents? 63.2455 Section 63.2455 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... must I meet for continuous process vents? (a) You must meet each emission limit in Table 1 to this subpart that applies to your continuous process vents, and you must meet each applicable...

  11. Numerical simulation and exergetic analysis of building ventilation solar chimneys

    International Nuclear Information System (INIS)

    Highlights: • Exergetic analysis of a building ventilation solar chimney. • Numerical CFD model developed, validated and employed to study the flow. • Analysis of the solar chimney energy and exergy efficiencies. • Mechanical and thermal exergy distributions have been analysed. • Crucial points in the chimney identified to improve its performance. - Abstract: The solar chimneys used in buildings are passive solar devices which improve natural ventilation. A detailed exergetic analysis has been developed in this work, both for general balance and specific variables. To apply this analysis, a three-dimensional CFD model has been built and validated with bibliographic experimental data. The values of the variables have been examined both inside and at the exit of the solar chimney, resulting in a detailed description of the inner phenomena and parameters influencing the exergetic efficiency. The results of this study offer new tools: a numerical methodology and an exergetic analysis, to improve the design of building ventilation solar chimneys. It also affords a deeper understanding of the thermal and fluid-dynamic behaviour, and suggests some qualitative improvements. However, the numerical data obtained from the case studied, show that solar chimneys as natural ventilation systems offer quite a small efficiency and will remain within the sphere of architectural decisions

  12. Free-standing inflatable solar chimney: experiment and theory

    Science.gov (United States)

    Vorobieff, Peter; Mammoli, Andrea; Fathi, Nima; Putkaradze, Vakhtang

    2014-11-01

    Solar chimneys (or solar updraft towers) offer an attractive way to use solar energy for production of baseload power. In a power plant of this type, sunshine heats the air under a wide greenhouse-like roofed collector surrounding the central base of a tall chimney. The heated air drives an updraft flow through the tower, whose energy is harvested with turbines. For a sufficiently large plant of this type, the thermal mass of the heated ground under the collector is sufficient to drive the flow even when the sun is down. The primary challenge in building the solar chimney power plant is the construction of the chimney that generates the updraft, which must be very tall (hundreds of meters for a commercial-sized plant). Here we present a study of an inflatable chimney which is a self-supporting, deformable, free-standing stack of gas-filled tori. The structure is stabilized via a combination of shape, overpressure, and buoyancy. Theoretical considerations suggest that filling the tori with air rather than with a light gas may be advantageous for stability. The chimney shape is optimized for deformation under wind loading. A prototype chimney has demonstrated the viability of the concept, with experimental results in good agreement with theoretical predictions. This research is partially supported by the UNM Research Allocations Comittee (RAC) and UNM Center for Emerging Energy Technologies (CEET).

  13. Replacive sulfide formation in anhydrite chimneys from the Pacmanus hydrothermal field, Papua New Guinea

    Science.gov (United States)

    Los, Catharina; Bach, Wolfgang; Plümper, Oliver

    2016-04-01

    chimney conduit started anhydrite corrosion, perhaps because they were undergoing cooling and became anhydrite undersaturated. From these fluids, sulfides precipitated in the newly formed pores. Compared to more evolved hydrothermal systems like TAG, the Pacmanus vent field shows only the beginning of sulfide formation. However, this early stage is the key to understand how replacement is going on, and how sulfidization can lead to a massive sulfide deposit.

  14. Experimental Investigations on Performance and Design Parameters of Solar Chimney

    OpenAIRE

    İbrahim ÜÇGÜL; KOYUN, Arif

    2010-01-01

    In this study, a solar chimney system, which is suitable for climate conditions of Isparta and its surroundings, is designed theoretically. With the aim of studying experimentally as based on that design, a prototype solar chimney has been constructed in the university campus area of Süleyman Demirel University-RACRER (Research and Application Center for Renewable Energy Resources). Additionally, after the experimental studies, the system is modelled theoretically with depending on the design...

  15. Seismic response Analyses of Hanaro in-chimney bracket structures

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jae Han; Ryu, J.S.; Cho, Y.G.; Lee, H.Y.; Kim, J.B

    1999-05-01

    The in-chimney bracket will be installed in the upper part of chimney, which holds the capsule extension pipes in upper one-third of length. For evaluating the effects on the capsules and related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response anlayses of in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of OBE (0.1 g) and SSE (0.2 g) are performed. The maximum horizontal displacements of the flow tubes are within the minimum half gaps between close flow tubes, it is expected that these displacement will not produce any contact between neighbor flow tubes. The stress values in main points of reactor structures and in-chimney bracket for the seismic loads are also within the ASME Code limits. It is also confirmed that the fatigue usage factor is muchless than 1.0. So, any damage on structural integrity is not expected when an in-chimney bracket is installed to upper part of the reactor chimney. (author). 12 refs., 24 tabs., 37 figs.

  16. Arsenic speciation in food chains from mid-Atlantic hydrothermal vents

    Science.gov (United States)

    Taylor, Vivien F.; Jackson, Brian P.; Siegfried, Matthew R.; Navratilova, Jana; Francesconi, Kevin A.; Kirshtein, Julie; Voytek, Mary

    2012-01-01

    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.

  17. In situ ore formation experiment: Amino acids and amino sugars trapped in artificial chimneys on deep-sea hydrothermal systems at Suiyo Seamount, Izu-Bonin Arc, Pacific Ocean

    CERN Document Server

    Takano,; Marumo,; K.,; Ebashi,; T.,; Gupta,; P., L; Kawahata,; H.,; Kobayashi,; K.,; Yamagishi,; A.,; Kuwabara,; T,

    2013-01-01

    The present study reports on the bio-organic composition of a deep-sea venting hydrothermal system originating from arc volcanism; the origin of the particulates in hydrothermal fluids from the Suiyo Seamount in the southern Izu-Bonin (Ogasawara) Arc is discussed with regard to amino compounds. Chimney samples on deep-sea hydrothermal systems and core samples at Suiyo Seamount were determined for amino acids, and occasionally amino sugars. Two types of chimney samples were obtained from active hydrothermal systems by submersible vehicles: one was natural chimney (NC) on a hydrothermal natural vent; the other was artificial chimneys (AC), mainly formed by the growth and deposition of sulfide-rich particulate components in a Kuwabara-type in situ incubator (KI incubator). Total hydrolyzed amino acids (THAA) and hydrolyzed hexosamines (HA) in AC ranged from 10.7 nmol/g to 64.0 nmol/g and from 0 nmol/g to 8.1 nmol/g, respectively, while THAA in hydrothermally altered core samples ranged from 26.0 nmol/g to 107.4 ...

  18. From Geochemistry to Biochemistry: Simulating Prebiotic Chemistry Driven by Geochemical Gradients in Alkaline Hydrothermal Vents

    Science.gov (United States)

    Barge, Laurie

    2016-07-01

    Planetary water-rock interfaces generate energy in the form of redox, pH, and thermal gradients, and these disequilibria are particularly focused in hydrothermal vent systems where the reducing, heated hydrothermal fluid feeds back into the more oxidizing ocean. Alkaline hydrothermal vents have been proposed as a likely location for the origin of life on the early Earth due to various factors: including the hydrothermal pH / Eh gradients that resemble the ubiquitous electrical / proton gradients in biology, the catalytic hydrothermal precipitates that resemble inorganic catalysts in enzymes, and the presence of electron donors and acceptors in hydrothermal systems (e.g. H2 + CH4 and CO2) that are thought to have been utilized in the earliest metabolisms. Of particular importance for the emergence of metabolism are the mineral "chimneys" that precipitate at the vent fluid / seawater interface. Hydrothermal chimneys are flow-through chemical reactors that form porous and permeable inorganic membranes transecting geochemical gradients; in some ways similar to biological membranes that transect proton / ion gradients and harness these disequilibria to drive metabolism. These emergent chimney structures in the far-from-equilibrium system of the alkaline vent have many properties of interest to the origin of life that can be simulated in the laboratory: for example, they can generate electrical energy and drive redox reactions, and produce catalytic minerals (in particular the metal sulfides and iron oxyhydroxides - "green rust") that can facilitate chemical reactions towards proto-metabolic cycles and biosynthesis. Many of the factors prompting interest in alkaline hydrothermal vents on Earth may also have been present on early Mars, or even presently within icy worlds such as Europa or Enceladus - thus, understanding the disequilibria and resulting prebiotic chemistry in these systems can be of great use in assessing the potential for other environments in the Solar

  19. Experimental study for natural ventilation on a solar chimney

    Energy Technology Data Exchange (ETDEWEB)

    Arce, J. [Centro de Investigacion en Energia (CIE-UNAM), Termociencias, Priv. Xochicalco S/N Col. Centro, Temixco, Morelos, CP 62580 (Mexico); Jimenez, M.J.; Guzman, J.D.; Heras, M.R. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Av. Complutense, 22, E-28040 Madrid (Spain); Alvarez, G.; Xaman, J. [Centro Nacional de Investigacion y Desarrollo Tecnologico (CENIDET-DGEST-SEP), Prol. Av. Palmira S/N. Col. Palmira, Cuernavaca, Morelos, CP 62490 (Mexico)

    2009-12-15

    Thermal performance of a solar chimney for natural ventilation was experimentally investigated. The experimental model was implemented on full scale and real meteorological conditions, so that experimental results will be compared with the simulation results. The results show that for a maximum irradiance of 604 W/m{sup 2}, occurring around 13:00 h on September 15th, 2007, a maximum air temperature increment of 7 C was obtained through the solar chimney. Also, a volumetric air flow rate ranging from 50 to 374 m{sup 3}/h was measured on that day. Thus, an average air flow rate of 177 m{sup 3}/h was achieved from 0:00 h to 24:00 h. The experimental solar chimney discharge coefficient, C{sub d}, was 0.52. This coefficient is useful to determine the mass flow rate in the solar chimney design. It was observed that the air flow rate through the solar chimney is influenced by a pressure difference between input and output, caused by thermal gradients and wind velocity, mainly. (author)

  20. Experimental investigations of a chimney-dependent solar crop dryer

    Energy Technology Data Exchange (ETDEWEB)

    Afriyie, J.K.; Nazha, M.A.A.; Rajakaruna, H. [School of Engineering and Technology, De Montfort University, Queens Building, The Gateway, Leicester LE1 9BH (United Kingdom); Forson, F.K. [Department of Mechanical Engineering, Kwame Nkrumah University of Science and Technology, Kumasi (Ghana)

    2009-01-15

    An experimental investigation into the performance of a solar crop dryer with solar chimney and no air preheating is described. Tests were first performed on the cabinet dryer, using a normal chimney. The trials were repeated with a solar chimney. Still with the solar chimney, further trials were carried out with the roof of the drying chamber inclined further to form a tent dryer. The described tests include no-load tests for airflow rate measurements and drying tests, with cassava as the crop. Air velocities, temperatures, ambient relative humidity and the drop in crop moisture contents at different stages of the drying process are also presented. The effects of the various configurations described above on the drying process are deduced and discussed while comparing the experimental results with one another. In addition, the performance of the dryer in relation to other natural convection dryers is discussed. The results show that the solar chimney can increase the airflow rate of a direct-mode dryer especially when it is well designed with the appropriate angle of drying-chamber roof. However, the increase in flow rate only increases the drying rate when the relative humidity (RH) of the ambient air is below a certain mark (60% for cassava). (author)

  1. The experimental design of solar heating thermoelectric generator with wind cooling chimney

    International Nuclear Information System (INIS)

    Highlights: • We model an experimental design of thermal electrical generator. • Electrical parameters were collected under the solar radiation. • All the calculated values were obtained from collected data. • Generated power and electrical efficiency were changed by thermal gradient. - Abstract: In this paper we present an experimental design of new solar based thermoelectric generator with wind chimney. Presented generator mainly consists of four parts: a heat pipe with solar collector tube for solar heating, a wind chimney for cooling, a thermoelectric (TE) module for electricity generation and measurement devices-sensors. Presented generator based on experimental design. Aim of this experimental design is to show an alternative way for cheap and efficiently renewable energy producing. The most important features of presented generator are uncomplicated structure, efficiently and cheapness. This experimental design can be improved and used for domestic and commercial application. For this reason, main parts of system can be enhanced and system can be improved. To evaluate of presented generator we collected some experimental data on designed system. Then maximum output power, electrical efficiency and Seebeck coefficient are calculated from obtained data. Results of the measurement are displayed in the form of graphs and tables. Our experiment was carried out on 16th and 21th August, in Samsun, on the north coast of Turkey with the exact location 41°14′N 36°26′E with sea level. Collection of the data was performed from 8:30 a.m. to 4 p.m

  2. Metal sources of black smoker chimneys, Endeavour Segment, Juan de Fuca Ridge: Pb isotope constraints

    Energy Technology Data Exchange (ETDEWEB)

    Yao Huiqiang, E-mail: hqyao11@yahoo.com [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China); National Key Lab of Marine Geology, Tongji University, Shanghai 200092 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Zhou Huaiyang, E-mail: zhouhy@tongji.edu.cn [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China); National Key Lab of Marine Geology, Tongji University, Shanghai 200092 (China); Peng Xiaotong [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China); National Key Lab of Marine Geology, Tongji University, Shanghai 200092 (China); Bao Shenxu [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China); National Key Lab of Marine Geology, Tongji University, Shanghai 200092 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Wu Zijun; Li Jiangtao [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China); National Key Lab of Marine Geology, Tongji University, Shanghai 200092 (China); Sun Zhilei; Chen Zhiqiang; Li Jiwei [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China); National Key Lab of Marine Geology, Tongji University, Shanghai 200092 (China); Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Chen Guangqian [Guangzhou Institute of Geochemistry Chinese Academy of Science, Guangzhou 510640 (China)

    2009-10-15

    Hydrothermal chimney sulfides, vent cap chimney samples, Fe-oxide and basalts from sediment-starving Juan de Fuca Ridge, in the Endeavour segment, exhibit a range of Pb isotope ratios ({sup 206}Pb/{sup 204}Pb = 18.658-18.769; {sup 207}Pb/{sup 204}Pb = 15.457-15.566; {sup 208}Pb/{sup 204}Pb = 37.810-38.276). The data array is not parallel to the northern hemisphere mantle reservoirs indicating a possible sediment component within the sulfides. By assuming that the potential end-member sediment component has a {sup 207}Pb/{sup 204}Pb (15.70) similar to Middle Valley sediment, it is suggested the potential end-member sediment component may have {sup 206}Pb/{sup 204}Pb = 18.90; {sup 208}Pb/{sup 204}Pb = 38.82. Basalt-derived Pb for the Endeavour segment hydrothermal system involves about 50/50 leaching of E-MORB and T2-MORB. Detailed observations show the Mothra field derives more Pb from T2-MORB than the Main Endeavour field does. According to the binary mixing model, the results show little Pb (<1.5%) or no Pb derivation from sedimentary sources. However, the high NH{sub 4}{sup +}, CH{sub 4} and Br/Cl ratios in hydrothermal fluids are consistent with a sediment component within the segment. Reconciling the Pb isotope data with the chemistry data of hydrothermal fluids, it is suggested that the sediment component may be located in a lower temperature recharge zone where Pb could not be mobilized from the sediment.

  3. Understanding vented gas explosions

    Energy Technology Data Exchange (ETDEWEB)

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

    1997-12-31

    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.

  4. Corrosion at system chimneys made of CrNi-steels

    Energy Technology Data Exchange (ETDEWEB)

    Pajonk, Gunther [Institute of Materials Testing of Northrhine-Westfalia, D-44285 Dortmund (Germany)

    2004-07-01

    Names like 'chimney' und 'funnel' usually identify flue gas devices made of bricks. Much less known is the fact that chimney elements are still manufactured from alloys. The following article describes the particular demands ruled by legislation on building pro-ducts, just as the consequences resulting from corrosion loads by flue gas condensates. Difficulties caused by manufacturing and construction are primarily discussed. Furthermore a test procedure is introduced that allows to catch and correlate corrosion loads and technical designs systematically to corrosion behaviour and service life of flue gas devices. For the first time a tool for active quality assurance has been given by this test rig allowing to recognize construction errors systematically. This way, manufacturers of system chimneys and flue liners are enabled to optimize their products applications going ahead to the respective requests of the market. (authors)

  5. Macrofauna of shallow hydrothermal vents on the Arctic Mid-Ocean Ridge at 71N

    Science.gov (United States)

    Schander, C.; Rapp, H. T.; Pedersen, R. B.

    2007-12-01

    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. Specialized vent fauna includes various animal phyla, but the most conspicuous and well known are annelids, mollusks and crustaceans. We have investigated the fauna collected around newly discovered hydrothermal vents on the Mohns Ridge north of Jan Mayen. The venting fields are located at 71°N and the venting takes place within two main areas separated by 5 km. The shallowest vent area is at 500-550 m water depth and is located at the base of a normal fault. This vent field stretches approximately 1 km along the strike of the fault, and it is composed of 10-20 major vent sites each with multiple chimney constructions discharging up to 260°C hot fluids. A large area of diffuse, low- temperature venting occurs in the area surrounding the high-temperature field. Here, partly microbial mediated iron-oxide-hydroxide deposits are abundant. The hydrothermal vent sites do not show any high abundance of specialized hydrothermal vent fauna. Single groups (i.e. Porifera and Mollusca) have a few representatives but groups otherwise common in hydrothermal vent areas (e.g. vestimentifera, Alvinellid worms, mussels, clams, galathaeid and brachyuran crabs) are absent. Up until now slightly more than 200 species have been identified from the vent area. The macrofauna found in the vent area is, with few exceptions, an assortment of bathyal species known in the area. One endemic, yet undescribed, species of mollusc has been found so far, an gastropod related to Alvania incognita Warén, 1996 and A. angularis Warén, 1996 (Rissoidae), two species originally described from pieces of sunken wood north and south of Iceland. It is by far the most numerous mollusc species at the vents and was found on smokers, in the bacterial mats, and on the ferric deposits. A single specimen of an undescribed tanaidacean has also

  6. Microbial and Mineral Descriptions of the Interior Habitable Zones of Active Hydrothermal Chimneys from the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

    Holden, J. F.; Lin, T.; Ver Eecke, H. C.; Breves, E.; Dyar, M. D.; Jamieson, J. W.; Hannington, M. D.; Butterfield, D. A.; Bishop, J. L.; Lane, M. D.

    2013-12-01

    Actively venting hydrothermal chimneys and their associated hydrothermal fluids were collected from the Endeavour Segment, Juan de Fuca Ridge to determine the mineralogy, chemistry and microbial community composition of their interiors. To characterize the mineralogy, Mössbauer, FTIR, VNIR and thermal emission spectroscopies were used for the first time on this type of sample in addition to thin-section petrography, x-ray diffraction and elemental analyses. A chimney from the Bastille edifice was Fe-sulfide rich and composed primarily of chalcopyrite, marcasite-sphalerite, and pyrrhotite while chimneys from the Dante and Hot Harold edifices were Fe-sulfide poor and composed primarily of anhydrite. The bulk emissivity and reflectance spectroscopies corroborated well with the petrography and XRD analyses. The microbial community in the interior of Bastille was most closely related to mesophilic-to-thermophilic anaerobes of the deltaproteobacteria and hyperthermophilic archaea while those in the interiors of Dante and Hot Harold were most closely related to mesophilic-to-thermophilic aerobes of the beta-, gamma- and epsilonproteobacteria. The fluid temperatures (282-321°C) and chemistries of the three chimneys were very similar suggesting that differences in mineralogy and microbial community compositions were more dependent on fluid flow characteristics and paragenesis within the chimney. Thin-section petrography of the interior of another hydrothermal chimney collected from the Dante edifice (emitting 336°C fluid) shows a thin coat of Fe3+ oxide associated with amorphous silica on the exposed outer surfaces of pyrrhotite, sphalerite and chalcopyrite in pore spaces, along with anhydrite precipitation in the pores that is indicative of seawater ingress. The Fe-sulfide minerals were likely oxidized to ferrihydrite with increasing pH and Eh due to cooling and seawater exposure, providing reactants for bioreduction. Culture-based most-probable-number estimates of

  7. Hydrothermal carbonate chimneys from a continental rift (Afar Rift): Mineralogy, geochemistry, and mode of formation

    OpenAIRE

    Dekov, V. M.; Egueh, N. M.; Kamenov, G.D.; Bayon, G.; Lalonde, S. V.; Schmidt, Mark; Liebetrau, Volker; Munnik, F.; Fouquet, Y.; Tanimizu, M.; Awaleh, M. O.; Guirreh, I.; Le Gall, B.

    2014-01-01

    International audience Carbonate chimney-like deposits up to 60 m high are scattered or arranged in rows at the shores of a desiccating hypersaline and alkaline lake from a continental rift setting (Lake Abhé, Afar Rift, Djibouti). The chimneys formed sub-aqueously in the lake water body at a higher water level than observed today. Alternating calcite and low-Mg calcite + silica concentric layers compose the chimney structures. Mineralogical and geochemical investigations of the chimneys, ...

  8. The contribution of trace elements from seawater to chimneys: a case study of the native sulfur chimneys in the sea area off Kueishantao, northeast of Taiwan Island

    Institute of Scientific and Technical Information of China (English)

    LIU Changhua; WANG Xiaomei; JIN Xindi; ZENG Zhigang; CHEN Chentung A.

    2009-01-01

    Hydrothermal fluid containing abundant matter erupts from seafloor, meets ambient cold seawater and forms chimneys. So the main matter origins of chimneys are seawater and matter which are taken by hydrothermal fluid from deep reservoir. However, because of seawater's little contribution to the forming of chimneys, it is usually covered by the abundant matter which is taken by hydrothermal fluid. Therefore, chimneys formed in ordinary deep seawater hydrothermal activity, containing complex elements, cannot be used to study the seawater's contribution to their formation. While the native sulfur chimneys, formed by hydrothermal activity near the sea area off Kueishantao, are single sulfur composition (over 99%), and within chimneys distinct layers are seen. Different layers were sampled for trace element determination, with Inductively Coupled Plasma Mass Spectrometry (ICP-MS). By analyzing the data, we consider C-layer (secondary inner-layer) as the framework layer of the chimney which formed early (Fig.4), and its trace elements derive from hydrothermal fluid. While the trace elements within A, B, D layers have undergone later alteration. A, B layers are affected by seawater and D layer by hydrothermal fluid. The increase of trace elements of A and B layers was calculated using C layer as background. Based on the known typical volume of chimneys of the near sea area off Kueishantao, we calculated the volume of seawater that contributed trace element to chimneys formation to be about 6.37×104 L. This simple quantified estimate may help us better understand the seafloor hydrothermal activity and chimneys.

  9. 24 CFR 3280.611 - Vents and venting.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Vents and venting. 3280.611 Section... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Plumbing Systems § 3280.611 Vents and venting... air circulation shall be ensured throughout all parts of the drainage system by means of...

  10. A performance analysis of solar chimney thermal power systems

    Directory of Open Access Journals (Sweden)

    Al-Dabbas Awwad Mohammed

    2011-01-01

    Full Text Available The objective of this study was to evaluate the solar chimney performance theoretically (techno-economic. A mathematical model was developed to estimate the following parameter: Power output, Pressure drop across the turbine, the max chimney height, Airflow temperature, and the overall efficiency of solar chimney. The mathematical model was validated with experimental data from the prototype in Manzanares power. It can be concluded that the differential pressure of collector-chimney transition section in the system, is increase with the increase of solar radiation intensity. The specific system costs are between 2000 Eur/kW and 5000 Eur/kW depending on the system size, system concept and storage size. Hence, a 50 MWe solar thermal power plant will cost 100-250 Eur million. At very good sites, today’s solar thermal power plants can generate electricity in the range of 0.15 Eur/kWh, and series production could soon bring down these costs below 0.10 Eur /kWh.

  11. Safety Injection System Filling Using Dynamic Venting

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung Je; Kim, Wong Bae; Huh, Jin; Lee, Joo Hee; Im, In Young; Kim, Eun kee [KEPCO Engineering and Construction Company, Daejeon (Korea, Republic of)

    2015-05-15

    In the APR+, the water-level elevation of the in-containment refueling water storage tank (IRWST) is lower than the highest piping of the SIS. Since the gravity filling of water from IRWST cannot fill all SIS piping, an SIP or an SCP test line is newly provided in order to allow the dynamic venting of the SIS. NEI 09-10 Revision 1a-A has concluded that use of dynamic venting is an effective means to remove gas from local high points and traps in piping when correctly based on the dynamic flow rate, void volume, Floude number, and the system water volume. In this study, feasibility of the dynamic vent is investigated. The work presented in this study evaluates the SIS and the SCS filling using the dynamic venting which is supposed to be applied to the APR+. The main ideas are as follows; 1. Dynamic venting using SIPs for the APR+ is not appropriate on the basis of 12 inches in diameter and with the flow rate, 1,460 gpm. 2. Because the high point of the SIS and the SCS is located at the piping that the two systems are sharing, the accumulated gas at the highest point can be removed by using the SCPs, and the dimension of the new piping will be determined by its length of them and the number of elbows. The calculated results are shown in Table 2. 3. The applicability of the dynamic venting methods using the SCPs that are mentioned above should be evaluated in the aspect of the system operation after the piping arrangements are settled in the APR+. The assessments to determine the pump operation time are also required.

  12. The impact of the combined chimney outlet size and extended solar wall-roof chimney on airflow patterns using numerical simulation

    Energy Technology Data Exchange (ETDEWEB)

    AboulNaga, M.M.; Alteraifi, A.M.

    1999-07-01

    This paper investigates airflow patterns and behavior of combined roof and extended solar wall-roof chimney incorporated into a typical room with an inlet and outlet. Numerical simulations using the Fluid Dynamics software Package, FIDAP, are exploited to describe and analyze the airflow patterns inside the room, and in the extended solar wall-roof chimneys. FIDAP simulation analyses and results of the airflow streamline, velocity vectors, and temperature distributions are presented. Maximum velocity vector, temperatures, and smooth streamlines were found for better performance at separation of 0.25m. At 0.25m separation, in both wall and roof solar chimneys, the maximum chimney outlet flow rate and smooth streamline were found when the wall chimney is 2.00m high, which corresponds to a wall chimney inlet of 1.60m. Results show that the maximum relative speed in the combined chimneys is higher than the solar roof chimney alone. These findings suggest that the exploitation of an extended solar roof-wall chimney could enhance nighttime natural ventilation and the cooling of buildings. The system is limited to cool low-rise buildings in hot-arid regions such as Al-Ain City, UAE, where energy use is enormous.

  13. Microbial diversity in deep-sea sediments from the Menez Gwen hydrothermal vent system of the Mid-Atlantic Ridge.

    Science.gov (United States)

    Cerqueira, Teresa; Pinho, Diogo; Egas, Conceição; Froufe, Hugo; Altermark, Bjørn; Candeias, Carla; Santos, Ricardo S; Bettencourt, Raul

    2015-12-01

    Deep-sea hydrothermal sediments are known to support remarkably diverse microbial consortia. Cultureindependent sequence-based technologies have extensively been used to disclose the associated microbial diversity as most of the microorganisms inhabiting these ecosystems remain uncultured. Here we provide the first description of the microbial community diversity found on sediments from Menez Gwen vent system. We compared hydrothermally influenced sediments, retrieved from an active vent chimney at 812 m depth, with non-hydrothermally influenced sediments, from a 1400 m depth bathyal plain. Considering the enriched methane and sulfur composition of Menez Gwen vent fluids, and the sediment physicochemical properties in each sampled area, we hypothesized that the site-associated microbes would be different. To address this question, taxonomic profiles of bacterial, archaeal and micro-eukaryotic representatives were studied by rRNA gene tag pyrosequencing. Communities were shown to be significantly different and segregated by sediment geographical area. Specific mesophilic, thermophilic and hyperthermophilic archaeal (e.g., Archaeoglobus, ANME-1) and bacterial (e.g., Caldithrix, Thermodesulfobacteria) taxa were highly abundant near the vent chimney. In contrast, bathyal-associated members affiliated to more ubiquitous phylogroups from deep-ocean sediments (e.g., Thaumarchaeota MGI, Gamma- and Alphaproteobacteria). This study provides a broader picture of the biological diversity and microbial biogeography, and represents a preliminary approach to the microbial ecology associated with the deep-sea sediments from the Menez Gwen hydrothermal vent field.

  14. Microbial diversity of a sulfide black smoker in main endeavour hydrothermal vent field, Juan de Fuca Ridge.

    Science.gov (United States)

    Zhou, Huaiyang; Li, Jiangtao; Peng, Xiaotong; Meng, Jun; Wang, Fengping; Ai, Yuncan

    2009-06-01

    Submarine hydrothermal vents are among the least-understood habitats on Earth but have been the intense focus of research in the past 30 years. An active hydrothermal sulfide chimney collected from the Dudley site in the Main Endeavour vent Field (MEF) of Juan de Fuca Ridge was investigated using mineralogical and molecular approaches. Mineral analysis indicated that the chimney was composed mainly of Fe-, Zn-and Cu-rich sulfides. According to phylogenetic analysis, within the Crenarchaeota, clones of the order Desulfurococcales predominated, comprising nearly 50% of archaeal clones. Euryarchaeota were composed mainly of clones belonging to Thermococcales and deep-sea hydrothermal vent Euryarchaeota (DHVE), each of which accounted for about 20% of all clones. Thermophilic or hyperthermophilic physiologies were common to the predominant archaeal groups. More than half of bacterial clones belonged to epsilon-Proteobacteria, which confirmed their prevalence in hydrothermal vent environments. Clones of Proteobacteria (gamma-, delta-, beta-), Cytophaga-Flavobacterium-Bacteroides (CFB) and Deinococcus-Thermus occurred as well. It was remarkable that methanogens and methanotrophs were not detected in our 16S rRNA gene library. Our results indicated that sulfur-related metabolism, which included sulfur-reducing activity carried out by thermophilic archaea and sulfur-oxidizing by mesophilic bacteria, was common and crucial to the vent ecosystem in Dudley hydrothermal site. PMID:19557339

  15. Detection of active hydrothermal vent fields in the Pescadero Basin and on the Alarcon Rise using AUV multibeam and CTD data

    Science.gov (United States)

    Caress, D. W.; Troni, G.; Clague, D. A.; Paduan, J. B.; Martin, J. F.; Thomas, H. J.; Thompson, D.; Conlin, D.; Martin, E. J.; meneses-Quiroz, E.; Nieves-Cardoso, C.; Angel Santa Rosa del Rio, M.

    2015-12-01

    The MBARI AUV D. Allan B. collected high resolution bathymetry, sidescan, and subbottom profiles along the neovolcanic zone of the Alarcon Rise and across the southern Pescadero Basin during 2012 and 2015 MBARI expeditions to the Gulf of California (GOC). The combination of high resolution multibeam bathymetry and seawater temperature data has proven effective in identifying active high temperature vent fields, as validated by inspection and sampling during ROV dives. The AUV carries a 200 kHz multibeam sonar, 110 kHz chirp sidescan sonar, a 1-6 kHz chirp subbottom profiler, and a conductivity, temperature and depth (CTD) sensor for ~17-hour duration missions. Flying at 5.4 km/hr at 50 m altitude, the processed AUV bathymetry has a 0.1 m vertical precision and a 1 m lateral resolution. Chimneys taller than 1.5 m are sufficiently distinctive to allow provisional identification. The CTD temperature data have a nominal 0.002°C accuracy. Following calculation of potential temperature and correcting for average local variation of potential temperature with depth, anomalies greater than 0.05 °C can be reliably identified using a spike detection filter. MBARI AUV mapping surveys are typically planned using a 150 m survey line spacing, so the CTD data may be collected as much as 75 m away from any vent plume source. Five active high temperature vent fields were discovered in the southern GOC, with the Auka Field in the southern Pescadero Basin, and the Ja Sít, Pericú, Meyibó, and Tzab-ek Fields along the Alarcon Rise. In all five cases, hydrothermal vent chimneys are readily identifiable in the multibeam bathymetry, and temperature anomalies are observed above background variability. Other apparent hydrothermal chimneys were observed in the bathmetry that did not exhibit water temperature anomalies; most of these were visited during ROV dives and confirmed to be inactive sites. The maximum water column anomalies are 0.13°C observed above the Meyibó field and 0.25

  16. Phylogenetic diversity of nitrogen-utilizing genes in hydrothermal chimneys from 3 middle ocean ridges.

    Science.gov (United States)

    Cao, Huiluo; Shao, Zongze; Li, Jiangtao; Zhang, Weipeng; Qian, Pei-Yuan

    2015-11-01

    Nitrogen-metabolizing genes, including nitrogenase (nifH), periplasmic nitrate reductase (napA), and cytochrome cd 1-type nitrite reductase (nirS), were collected from hydrothermal chimney sulfides on 3 middle ocean ridges and compared for the first time. There was a clear phylogenetic distinction of these nifH genes between different hydrothermal ecosystems, which supported the colonization and potential adaptation by different nitrogen fixing microbes in those sulfides. In particular, in sulfides from low-temperature hydrothermal vents of the Southwest Indian Ocean Ridge, the prevalence of nifH genes appears to be attributed to sulfate-reducing bacteria, suggesting their ecological significance. Phylogenetic analysis of nitrate/nitrite reductase genes indicated that nitrate was a critical electron acceptor for sulfur- or metal-oxidizing bacteria in these hydrothermal ecosystems. Our results provided information about the compositions and diversity of the 3 important genes involved in nitrogen fixation and nitrate/nitrite reduction processes in hydrothermal ecosystems and is the first comprehensive genetic repertoire of genes related to potential nitrogen fixation and denitrification processes in various hydrothermal environments.

  17. The computational optimization of heat exchange efficiency in stack chimneys

    Energy Technology Data Exchange (ETDEWEB)

    Van Goch, T.A.J.

    2012-02-15

    For many industrial processes, the chimney is the final step before hot fumes, with high thermal energy content, are discharged into the atmosphere. Tapping into this energy and utilizing it for heating or cooling applications, could improve sustainability, efficiency and/or reduce operational costs. Alternatively, an unused chimney, like the monumental chimney at the Eindhoven University of Technology, could serve as an 'energy channeler' once more; it can enhance free cooling by exploiting the stack effect. This study aims to identify design parameters that influence annual heat exchange in such stack chimney applications and optimize these parameters for specific scenarios to maximize the performance. Performance is defined by annual heat exchange, system efficiency and costs. The energy required for the water pump as compared to the energy exchanged, defines the system efficiency, which is expressed in an efficiency coefficient (EC). This study is an example of applying building performance simulation (BPS) tools for decision support in the early phase of the design process. In this study, BPS tools are used to provide design guidance, performance evaluation and optimization. A general method for optimization of simulation models will be studied, and applied in two case studies with different applications (heating/cooling), namely; (1) CERES case: 'Eindhoven University of Technology monumental stack chimney equipped with a heat exchanger, rejects heat to load the cold source of the aquifer system on the campus of the university and/or provides free cooling to the CERES building'; and (2) Industrial case: 'Heat exchanger in an industrial stack chimney, which recoups heat for use in e.g. absorption cooling'. The main research question, addressing the concerns of both cases, is expressed as follows: 'what is the optimal set of design parameters so heat exchange in stack chimneys is optimized annually for the cases in which a

  18. Composition of hydrothermal fluids and mineralogy of associated chimney material on the East Scotia Ridge back-arc spreading centre

    Science.gov (United States)

    James, Rachael H.; Green, Darryl R. H.; Stock, Michael J.; Alker, Belinda J.; Banerjee, Neil R.; Cole, Catherine; German, Christopher R.; Huvenne, Veerle A. I.; Powell, Alexandra M.; Connelly, Douglas P.

    2014-08-01

    The East Scotia Ridge is an active back-arc spreading centre located to the west of the South Sandwich island arc in the Southern Ocean. Initial exploration of the ridge by deep-tow surveys provided the first evidence for hydrothermal activity in a back-arc setting outside of the western Pacific, and we returned in 2010 with a remotely operated vehicle to precisely locate and sample hydrothermal sites along ridge segments E2 and E9. Here we report the chemical and isotopic composition of high- and low-temperature vent fluids, and the mineralogy of associated high-temperature chimney material, for two sites at E2 (Dog’s Head and Sepia), and four sites at E9 (Black & White, Ivory Tower, Pagoda and Launch Pad). The chemistry of the fluids is highly variable between the ridge segments. Fluid temperatures were ∼350 °C at all vent sites except Black & White, which was significantly hotter (383 °C). End-member chloride concentrations in E2 fluids (532-536 mM) were close to background seawater (540 mM), whereas Cl in E9 fluids was much lower (98-220 mM) indicating that these fluids are affected by phase separation. Concentrations of the alkali elements (Na, Li, K and Cs) and the alkaline earth elements (Ca, Sr and Ba) co-vary with Cl, due to charge balance constraints. Similarly, concentrations of Mn and Zn are highest in the high Cl fluids but, by contrast, Fe/Cl ratios are higher in E9 fluids (3.8-8.1 × 10-3) than they are in E2 fluids (1.5-2.4 × 10-3) and fluids with lowest Cl have highest Cu. Although both ridge segments are magmatically inflated, there is no compelling evidence for input of magmatic gases to the vent fluids. Fluid δD values range from 0.2‰ to 1.5‰, pH values (3.02-3.42) are not especially low, and F concentrations (34.6-54.4 μM) are lower than bottom seawater (62.8 μM). The uppermost sections of conjugate chimney material from E2, and from Ivory Tower and Pagoda at E9, typically exhibit inner zones of massive chalcopyrite enclosed

  19. Coil spring venting arrangement

    Science.gov (United States)

    McCugh, R.M.

    1975-10-21

    A simple venting device for trapped gas pockets in hydraulic systems is inserted through a small access passages, operated remotely, and removed completely. The device comprises a small diameter, closely wound coil spring which is pushed through a guide temporarily inserted in the access passage. The guide has a central passageway which directs the coil spring radially upward into the pocket, so that, with the guide properly positioned for depth and properly oriented, the coil spring can be pushed up into the top of the pocket to vent it. By positioning a seal around the free end of the guide, the spring and guide are removed and the passage is sealed.

  20. Formation of Chimneys in Mushy Layers: Experiment and Simulation

    CERN Document Server

    Anderson, Anthony M; Worster, Grae

    2011-01-01

    In this fluid dyanmics video, we show experimental images and simulations of chimney formation in mushy layers. A directional solidification apparatus was used to freeze 25 wt % aqueous ammonium chloride solutions at controlled rates in a narrow Hele-Shaw cell (1mm gap). The convective motion is imaged with schlieren. We demonstrate the ability to numerically simulate mushy layer growth for direct comparison with experiments.

  1. Power generation from wind turbines in a solar chimney

    Energy Technology Data Exchange (ETDEWEB)

    Foote, Tudor [Graduate Student, Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States); Agarwal, Ramesh K. [William Palm Professor, Department of Mechanical Engineering and Materials Science, Washington University in St. Louis, Jolley Hall, Campus Box 1185, One Brookings Drive, St. Louis, Missouri, 63130 (United States)

    2013-07-01

    Recent studies have shown that shrouded wind turbines can generate greater power compared to bare turbines. A solar chimney generates an upward draft of wind inside a tower and a shroud around the wind turbine. There are numerous empty silos on farms in the U.S. that can be converted to solar chimneys with minor modifications at modest cost. The objective of this study is to determine the potential of these silos/chimneys for generating wind power. The study is conducted through analytical/computational approach by employing the commercial Computational Fluid Dynamics (CFD) software. Computations are performed for five different geometric configurations consisting of a turbine, a cylindrical silo, and/or a venturi and/or a diffuser using the dimensions of typical silos and assuming Class 3 wind velocity. The incompressible Navier-Stokes equations with the Boussinesq approximation and a two equation realizable {kappa}-{epsilon} model are employed in the calculations, and the turbine is modeled as an actuator disk. The power coefficient (Cp) and generated power are calculated for the five cases. Consistent with recent literature, it was found that the silos with diffusers increase the Cp beyond Betz’s limit significantly and thus the generated power. It should be noted that Cp is calculated by normalizing it by the turbine area swept by the wind. This study shows the potential of using abandoned silos in the mid-west and other parts of the country for localized wind power generation.

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

    Science.gov (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.

    2010-12-01

    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

  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)

    2016-02-05

    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. Vent Relief Valve Test

    Science.gov (United States)

    2008-01-01

    Shown is the disassembly, examination, refurbishment and testing of the LH2 ( liquid hydrogen) and LOX (liquid oxygen) vent and relief valves for the S-IVB-211 engine stage in support of the Constellation/Ares project. This image is extracted from high definition video and is the highest resolution available.

  5. GEOCHEMICAL CHARACTERISTICS OF STABLE ISOTOPES FROM HYDROTHERMAL CHIMNEYS IN THE MARIANA TROUGH, WEST PACIFIC OCEAN

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The determination of the stable isotopes, δD, δ18O and δ30Si, values from hydrothermal chimneys in the Mariana Trough, the West Pacific, indicated that the pure siliceous chimneys with gentle data variation were formed in low temperature environment. It reflects that the sea-floor hydrothermal activity of the Mariana Trough is primarily low-to-medium temperature hydrothermal eruption, and those chimneys with strong data variation and containing pyrite were formed in higher temperature environment.

  6. Improvement of the Vertical Dispersion of Pollutants Resulting From Chimneys by Thermosiphon Effect

    OpenAIRE

    A. O.M. Mahmoud; J. Zinoubi; R.B. Maad; A. Belghith

    2006-01-01

    The dispersion of pollutants, resulting from industrial chimneys, in the surrounding atmosphere made the interest in realizing emitting conditions appears. It also encourages the vertical dispersion of these pollutants. At a given wind velocity, the height of this dispersion is essentially a function of the thermal power and the flow rate at the chimney exit. To improve these qualities, we propose a system that could be integrated to the industrial chimney exit. An open-ended vertical cylinde...

  7. Solar chimney design: Investigating natural ventilation and cooling in offices with the aid of computer simulation

    Science.gov (United States)

    Angelis, Nikolaos

    Solar chimney design is investigated as a means of improving natural ventilation and passive cooling in office buildings. Existing scientific research and built precedents are generally limited literature review findings on various features of solar chimneys were categorised and used to develop a building simulation strategy. Using UK climatic data, simulations were performed on several computer models in order to investigate solar chimney performance during a single day period and an entire cooling season. Passive cooling with a solar chimney is possible but actual reduction in temperatures in most cases examined could be negligible. Cooling potential is increased on still, warm days, while the prospects for night cooling are further improved. A solar chimney may help reduce considerably the occurrence of resultant temperatures at or above the 25 C and 28 C thresholds. Solar chimney width, height, apertures and integral use of thermal mass are the most significant parameters for cooling. Simulation results showed that a solar chimney can increase significantly natural ventilation rates. Total ventilation rates may be increased by at least 22%. During still days a solar chimney can enhance ventilation rates by 36% or more. Stack ventilation through a solar chimney is typically 20% of cross ventilation during night time this may increase to at least 40-45% and on still days it may reach 100% of typical cross ventilation rates. Solar chimney induced stack ventilation and cross ventilation are interrelated. Resultant air flow patterns may have an important effect on convective heat transfers and thermal comfort. Climate and microclimate conditions should be an integral part of solar chimney design. Key aspects and recommendations regarding solar chimneys, passive cooling and natural ventilation are provided for design guidance and feedback in further research.

  8. Neotectonic activity at the Giant Gjallar Vent (Norwegian Sea) indicates a future phase of active fluid venting

    Science.gov (United States)

    Dumke, Ines; Berndt, Christian; Crutchley, Gareth; Couillard, Mélanie; Gay, Aurélien

    2013-04-01

    seal to upward fluid migration. This probably results in the build-up of overpressure and may explain subsequent deformation of the overlying strata. A small chimney-like feature that extends from the unconformity to just below the seafloor, c. 800 m NE of the northern pipe, shows that the BLPU seal has been penetrated in at least one location. We propose that further loading and gas ascent will lead to a new phase of venting at the GGV in the future.

  9. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents and carburetor vapor vents... Fuel tank vents and carburetor vapor vents. (a) Fuel tank vents. Each fuel tank must be vented from the... addition— (1) Each vent must be arranged to avoid stoppage by dirt or ice formation; (2) The...

  10. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents and carburetor vapor vents... Fuel tank vents and carburetor vapor vents. (a) Fuel tank vents. Each fuel tank must be vented from the... addition— (1) The vents must be arranged to avoid stoppage by dirt or ice formation; (2) The...

  11. Microbial Diversity Associated with High Temperature Sulfide Deposits Along the East Pacific Rise Deep-Sea Hydrothermal Vents

    Science.gov (United States)

    Brooks, D.; Hoek, J.; Banta, A. B.; von Damm, K.; Reysenbach, A.

    2002-12-01

    In January 2002, hydrothermal chimneys were collected using DSV Alvin from active vents from 9° 17N to 9° 50N and 20° 49N to 20° 50N. Hydrothermal fluids were collected for end member chemistry prior to collecting the sulfide deposits. Chimney samples were sub-sectioned, separating surface and associated biofilm samples from inner chimney samples. Microbial diversity of sub-samples was assessed using culture-dependent and culturing-independent small subunit (16S) ribosomal RNA-based techniques. Initial bacterial diversity assessments using denaturing gradient gel electrophoresis (DGGE) support the global prevalence of epsilon Proteobacteria associated with deep-sea sulfide structures. These are closely related to the sulfur-reducing isolate Nautilia lithotrophica. The biofilm communities varied in complexity with one sample containing several 16S rRNA sequences (phylotypes, OTU's) of alpha, epsilon, and gamma Proteobacteria while others contained a single phylotype of epsilon Proteobacteria. One proteobacterial phylotype was present in all but one of the surface samples, and this sample contained unique alpha and epsilon proteobacterial sequences. The inner chimney samples lacked the most common epsilon proteobacterial 16S rRNA sequences. Enrichment culturing was restricted to selecting for thermophilic chemolithoautotrophic hydrogen-oxidizing Bacteria. The widespread distribution of Persephonella spp. was confirmed, and novel enrichments of a sheathed and as yet unidentified chemolithotroph were obtained.

  12. Growth history of hydrothermal chimneys at EPR 9―10°N: A structural and mineralogical study

    Institute of Scientific and Technical Information of China (English)

    PENG Xiaotong; ZHOU Huaiyang

    2005-01-01

    Based on structural and mineralogical characteristics of four hydrothermal chimney samples collected by submersible Alvin, growth history and formation environment of hydrothermal chimney at EPR 9―10°N are established. It is shown that there occur two types of hydrothermal chimney with different deposition environments at EPR 9―10°N according to differences in their shape, structure and mineral assemblage: type I chimney forms in an environment with high temperature, low pH and strong reducing hydrothermal focus flow and type II chimney forms in a relatively low temperature, high pH and rich Zn hydrothermal environment. Growth of type I chimney begins with the formation of anhydrite. Subsequently deposition of Cu-Fe-Zn sulphide in various directions of chimneys decides the final structure of this type of chimney. According to observation and analysis of mineral assemblages, the formation process of type I chimney could be divided into three stages from early, middle to late. Changes of temperature and major chemical reaction type in the process of hydrothermal chimney formation are also deduced. Different from type I chimney, quenching crystalline of pyrite and/or crystalline of sphalerite provide the growth foundation of type II chimney in the early stage of chimney formation.

  13. Filtered-vented containment systems

    International Nuclear Information System (INIS)

    The potential benefits of filtered-vented containment systems as a means for mitigating the effects of severe accidents are analyzed. Studies so far have focused upon two operating reactor plants in the United States, a large-containment pressurized water reactor and a Mark I containment boiling water reactor. Design options that could be retrofitted to these plants are described including single-component once-through venting systems, multiple-component systems with vent and recirculation capabilities, and totally contained venting systems. A variety of venting strategies are also described which include simple low-volume containment pressure relief strategies and more complicated, high-volume venting strategies that require anticipatory actions. The latter type of strategy is intended for accidents that produce containment-threatening pressure spikes

  14. Solar ventilation: The use of solar chimneys for natural ventilation of buildings

    NARCIS (Netherlands)

    Macquoy, B.

    2011-01-01

    This paper is written for the TIDO-course AR0532 Smart & Bioclimatic Design Theory. A very old principle is the system of the solar chimney for ventilation, which in recent years has regained interests. This essay will explore the potentials of solar chimneys in a modern application.

  15. Methane seepage in the Shenhu area of the northern South China Sea: constraints from carbonate chimneys

    Science.gov (United States)

    Guan, Hongxiang; Zhang, Mei; Mao, Shengyi; Wu, Nengyou; Lu, Hongfeng; Chen, Duofu

    2016-06-01

    Two authigenic carbonate chimneys were recovered from the Shenhu area in the northern South China Sea at approximately 400 m water depth. The chimneys' mineralogy, isotopic composition, and lipid biomarkers were studied to examine the biogeochemical process that induced the formation of the chimneys. The two chimneys are composed mostly of dolomite, whereas the internal conduits and semi-consolidated surrounding sediments are dominated by aragonite and calcite. The specific biomarker patterns (distribution of lipids and their depleted δ13C values) indicate the low occurrence of methanotrophic archaea ANME-1 responsible for the chimneys' formation via anaerobic oxidation of methane. A significant input of bacteria/planktonic algae and cyanobacteria to the carbon pool during the precipitation of the carbonate chimneys is suggested by the high contributions of short-chain n-alkanes (69% of total hydrocarbons) and long-chain n-alcohols (on average 56% of total alcohols). The oxygen isotopic compositions of the carbonate mixtures vary from 3.1‰ to 4.4‰ in the dolomite-rich chimneys, and from 2.1‰ to 2.5‰ in the internal conduits, which indicates that they were precipitated from seawater-derived pore waters during a long period covering the last glacial and interglacial cycles. In addition, the mixture of methane and bottom seawater dissolved inorganic carbon could be the carbon sources of the carbonate chimneys.

  16. 46 CFR 154.805 - Vent masts.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vent masts. 154.805 Section 154.805 Shipping COAST GUARD...-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Cargo Vent Systems § 154.805 Vent masts. Relief valves or common vent headers from relief valves must discharge to a vent...

  17. Hydrothermal vents near a mantle hot spot: the Lucky Strike vent field at 37°N on the Mid-Atlantic Ridge

    Science.gov (United States)

    Langmuir, C.; Humphris, S.; Fornari, D.; Van Dover, C.; Von Damm, K.; Tivey, M. K.; Colodner, D.; Charlou, J.-L.; Desonie, D.; Wilson, C.; Fouquet, Y.; Klinkhammer, G.; Bougault, H.

    1997-04-01

    The Lucky Strike hydrothermal field occurs in the summit basin of a large seamount that forms the shallow center of a 65 km long ridge segment near 37°N on the Mid-Atlantic Ridge. The depth and chemistry of the ridge segment are influenced by the Azores hot spot, and this hydrothermal field is the first Atlantic site found on crust that is dominated by a hot spot signature. Multiple hydrothermal vents occur over an area of at least 300 m by 700 m. Vent morphologies range from flanges and chimneys with temperatures of 200-212°C, to black smoker chimneys with temperatures up to 333°C. Cooler fluids from northern vents have higher chlorinities and lower gas volumes, while hotter, southern fluids have chlorinities 20% below seawater with higher gas volumes, suggesting phase separation has influenced their compositions. All gas volumes in fluids are higher than those at TAG and Snake Pit hydrothermal fields. Black smokers exhibit their typical mineralogy, except that barite is a major mineral, particularly at lower-temperature sites, which contrasts with previously investigated Atlantic sites. The fluid chemistry, distribution of the relict sulfide deposits on the seamount summit in the areas investigated using DSV Alvin, and contact relationships between active vent sites and surrounding basaltic and sulfide substrate suggest that the hydrothermal system has a long history and may have recently been rejuvenated. Fauna at the Lucky Strike vent sites are dominated by a new species of mussel, and include the first reported sea urchins. The Lucky Strike biological community differs considerably from other vent fauna at the species level and appears to be a new biogeographic province. The Lucky Strike field helps to constrain how variations in the basaltic substrate influence the composition of hydrothermal fluids and solids, because basalt compositions at Lucky Strike are 10-30 times enriched in incompatible elements compared to other Atlantic hydrothermal sites such as

  18. Biogeography of bacteriophages at four hydrothermal vent sites in the Antarctic based on g23 sequence diversity.

    Science.gov (United States)

    Millard, Andrew D; Pearce, David; Zwirglmaier, Katrin

    2016-04-01

    In this study, which was carried out within the ChEsSO consortium project (Chemosynthetically driven ecosystems south of the Polar Front), we sampled two hydrothermal vent sites on the East Scotia Ridge, Scotia Sea, one in the Kemp Caldera, South Sandwich Arc and one in the Bransfield Strait, north-west of the Antarctic Peninsula, which exhibit strong differences in their chemical characteristics. We compared a subset of their bacteriophage population by Sanger- and 454-sequencing of g23, which codes for the major capsid protein of T4likeviruses. We found that the sites differ vastly in their bacteriophage diversity, which reflects the differences in the chemical conditions and therefore putatively the differences in microbial hosts living at these sites. Comparing phage diversity in the vent samples to other aquatic samples, the vent samples formed a distinct separate cluster, which also included the non-vent control samples that were taken several hundred meters above the vent chimneys. This indicates that the influence of the vents on the microbial population and therefore also the bacteriophage population extends much further than anticipated.

  19. Biogeography of bacteriophages at four hydrothermal vent sites in the Antarctic based on g23 sequence diversity.

    Science.gov (United States)

    Millard, Andrew D; Pearce, David; Zwirglmaier, Katrin

    2016-04-01

    In this study, which was carried out within the ChEsSO consortium project (Chemosynthetically driven ecosystems south of the Polar Front), we sampled two hydrothermal vent sites on the East Scotia Ridge, Scotia Sea, one in the Kemp Caldera, South Sandwich Arc and one in the Bransfield Strait, north-west of the Antarctic Peninsula, which exhibit strong differences in their chemical characteristics. We compared a subset of their bacteriophage population by Sanger- and 454-sequencing of g23, which codes for the major capsid protein of T4likeviruses. We found that the sites differ vastly in their bacteriophage diversity, which reflects the differences in the chemical conditions and therefore putatively the differences in microbial hosts living at these sites. Comparing phage diversity in the vent samples to other aquatic samples, the vent samples formed a distinct separate cluster, which also included the non-vent control samples that were taken several hundred meters above the vent chimneys. This indicates that the influence of the vents on the microbial population and therefore also the bacteriophage population extends much further than anticipated. PMID:26903011

  20. Tree cavity use by Chimney Swifts: implications for forestry and population recovery

    Directory of Open Access Journals (Sweden)

    Carolyn Zanchetta

    2014-12-01

    Full Text Available The Chimney Swift (Chaetura pelagica is an aerial insectivore and a cavity-nesting/roosting specialist designated as threatened in several jurisdictions. As the occurrence of suitable chimneys declines, Chimney Swifts may increasingly nest and roost in tree cavities. It is therefore important to identify characteristics of suitable nest or roost trees and assess their frequency of occurrence. We reviewed 59 historic and modern records of trees used by Chimney Swifts to understand characteristics of suitable nest or roost trees. Chimney Swifts used at least 13 different deciduous and coniferous tree species. All of the trees were greater than 0.5 m diameter at breast height (DBH and were described as hollow or having cavities. Nest or roost tree height was 12.7 ± 7.0 m (mean ± SD; range: 3.6-28.0 m; n = 25 and DBH was 1.0 m ± 0.5 m (range 0.5-2.1 m; n = 21. According to our description of used trees, the number of suitably hollow Chimney Swift nest or roost trees may be two to three times higher, although still rare, in most unlogged compared to logged hardwood forests. Whether the current total supply of suitable nest or roost trees is sufficient to carry the anticipated increase in use by Chimney Swifts as chimney habitat is modified or deteriorates is unknown. Monitoring the frequency of use of tree cavities by nesting and roosting Chimney Swifts over time, and more robustly quantifying the availability of suitable tree cavities in different forest types for nesting and roosting Chimney Swifts, particularly in unlogged versus logged forests, are fruitful areas for future research.

  1. 14 CFR 23.975 - Fuel tank vents and carburetor vapor vents.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents and carburetor vapor vents... Powerplant Fuel System § 23.975 Fuel tank vents and carburetor vapor vents. (a) Each fuel tank must be vented from the top part of the expansion space. In addition— (1) Each vent outlet must be located...

  2. Tornado protection by venting

    International Nuclear Information System (INIS)

    The purpose of this paper is to demonstrate the ability to protect a modern nuclear power plant from the effects of a tornado by the use of a system of venting in all safety-related structures outside of the containment. The paper demonstrates this by presenting a method of analysis and of equipment selection that fully complies with the intent and the letter of applicable federal regulatory guides. A report of an actual tornado in the City of Kalamazoo, Michigan, suggests that the concept of sealing a plant during a tornado may not always be applicable

  3. EVALUATION OF SOIL VENTING APPLICATION

    Science.gov (United States)

    The ability of soil venting to inexpensively remove large amounts of volatile organic compounds (VOCs) from contaminated soils is well established. However, the time required using venting to remediate soils to low contaminant levels often required by state and federal regulators...

  4. Hydrothermal vents is Lake Tanganyika, East African Rift system

    Energy Technology Data Exchange (ETDEWEB)

    Tiercelin, J.J. [Universite de Bretagne Occidentale, Brest (France); Pflumio, C.; Castrec, M. [Universite Paris VI, Paris (France)] [and others

    1993-06-01

    Sublacustrine hydrothermal vents with associated massive sulfides were discovered during April 1987 at Pemba and Cape Banza on the Zaire side of the northern basin of Lake Tanganyika, East African Rift system. New investigations by a team of ten scuba divers during the multinational (France, Zaire, Germany, and Burundi) TANGANYDRO expedition (August-October 1991) found hydrothermal vents down to a depth of 46 m along north-trending active faults bounding the Tanganyika rift on the western side. Temperatures from 53 to 103 {degrees}C were measured in hydrothermal fluids and sediments. Veins of massive sulfides 1-10 cm thick (pyrite and marcasite banding) were found associated with vents at the Pemba site. At Cape Banza, active vents are characterized by 1-70-cm-high aragonite chimneys, and there are microcrystalline pyrite coatings on the walls of hydrothermal pipes. Hydrothermal fluid end members show distinctive compositions at the two sites. The Pemba end member is a NaHCO{sub 3}-enriched fluid similar to the NaHCO{sub 3} thermal fluids form lakes Magadi and Bogoria in the eastern branch of the rift. The Cape Banza end member is a solution enriched in NaCl. Such brines may have a deep-seated basement origin, as do the Uvinza NaCl brines on the eastern flank of the Tanganyika basin. Geothermometric calculations have yielded temperatures of fluid-rock interaction of 219 and 179 {degrees}C in the Pemba and Cape Banza systems, respectively. Abundant white or reddish-brown microbial colonies resembling Beggiatoa mats were found surrounding the active vents. Thermal fluid circulation is permitted by opening of cracks related to 130{degrees}N normal-dextral faults that intersect the north-south major rift trend. The sources of heat for such hydrothermal systems may relate to the existence of magmatic bodies under the rift, which is suggested by the isotopic composition of carbon dioxide released at Pemba and Cape Banza. 21 refs., 2 figs.

  5. Effect of solar chimney inclination angle on space flow pattern and ventilation rate

    Energy Technology Data Exchange (ETDEWEB)

    Bassiouny, Ramadan; Korah, Nader S.A. [Department of Mechanical Power Engineering and Energy, Minia University, Minia 61111 (Egypt)

    2009-02-15

    The solar chimney is a simple and practical idea that is applied to enhance space natural ventilation. The chimney could be vertical or inclined. The chimney inclination angle is an important parameter that greatly affects space flow pattern and ventilation rate. In the present study, the effect of chimney inclination angle on air change per hour and indoor flow pattern was numerically and analytically investigated. A numerical simulation using Ansys, a FEM-based code, was used to predict flow pattern. Then the results were compared with published experimental measurements. A FORTRAN program was developed to iteratively solve the mathematical model that was obtained through an overall energy balance on the solar chimney. The analytical results showed that an optimum air flow rate value was achieved when the chimney inclination is between 45 and 70 for latitude of 28.4 . The numerically predicted flow pattern inside the space supports this finding. Moreover, in the present study a correlation to predict the air change per hour was developed. The correlation was tested within a solar intensity greater than or equal to 500 W/m{sup 2}, and chimney width from 0.1 m to 0.35 m for different inclination angles with acceptable values. (author)

  6. Full scale monitoring of the twin chimneys of the rovinari power plant

    Directory of Open Access Journals (Sweden)

    Bayati I.

    2015-01-01

    Full Text Available The presented paper deals with the structural identification and monitoring of two twin chimneys in very close arrangement. Due to twin arrangement, important interference effects are expected to modify the chimney response to wind action, causing vortex shedding and state-dependent excitation associated to the oscillatory motion of the leeward chimney, in and out of the windward chimney wake. The complexity of the physics of this problem is increased by the dependency of the aerodynamics of circular cylinders on Reynolds number; however, there is a weakness of literature about cylinders behaviour at critical and super-critical range of Reynolds number, due to experimental limitations. Also the International Committee on Industrial Chimneys (CICIND does not provide, at present, any specific technical guideline about twin chimneys whose interaxis distance is less or equal two times the diameter, as in this case. For this reason a Tuned Mass Damper (TMD has been installed in order to increase the damping of the chimney, as merely suggested. This work aims at assessing the effectiveness of the installed TMD and characterizing the tower dynamic behaviour itself due to the wind excitation, as well as providing full scale measurements for twin cylinders configuration at high Reynolds numbers.

  7. ChEVAS: Combining Suprarenal EVAS with Chimney Technique

    Energy Technology Data Exchange (ETDEWEB)

    Torella, Francesco, E-mail: f.torella@liverpool.ac.uk [Royal Liverpool University Hospital, Liverpool Vascular & Endovascular Service (United Kingdom); Chan, Tze Y., E-mail: tze.chan@rlbuht.nhs.uk; Shaikh, Usman, E-mail: usman.shaikh@rlbuht.nhs.uk [Royal Liverpool University Hospital, Department of Radiology (United Kingdom); England, Andrew, E-mail: a.england@salford.ac.uk [University of Salford, Department of Radiography (United Kingdom); Fisher, Robert K., E-mail: robert.fisher@rlbuht.nhs.uk [Royal Liverpool University Hospital, Liverpool Vascular & Endovascular Service (United Kingdom); McWilliams, Richard G., E-mail: richard.mcwilliams@rlbuht.nhs.uk [Royal Liverpool University Hospital, Department of Radiology (United Kingdom)

    2015-10-15

    Endovascular sealing with the Nellix{sup ®} endoprosthesis (EVAS) is a new technique to treat infrarenal abdominal aortic aneurysms. We describe the use of endovascular sealing in conjunction with chimney stents for the renal arteries (chEVAS) in two patients, one with a refractory type Ia endoleak and an expanding aneurysm, and one with a large juxtarenal aneurysm unsuitable for fenestrated endovascular repair (EVAR). Both aneurysms were successfully excluded. Our report confirms the utility of chEVAS in challenging cases, where suprarenal seal is necessary. We suggest that, due to lack of knowledge on its durability, chEVAS should only been considered when more conventional treatment modalities (open repair and fenestrated EVAR) are deemed difficult or unfeasible.

  8. Chimney Effect Assessment of the Double-skin Facade

    Institute of Scientific and Technical Information of China (English)

    QIU Zhong-zhu; LI Peng; CHOW Tin-tai; REN Jian-xing; WANG Wen-huan

    2009-01-01

    The mathematic model of heat transfer through ventihted double glazing was verified with themeasured data,which were from a test chamber equipped with glass face temperature,solar radiation,ambient temperature,and wind speed measurement facility.Mter the model validation,the double-skin facade assess-ment was carried out through simulation with ESP-r software integrating thermal simulation and air low net work module.The air flow situation in the air gap was analyzed on the basis of the hourly air velocity simulation data within typical winter week,summer week,spring week and autumn week.The differences of chimney ef-fect in different seasons were discussed,and the thermal loads resulted from the ventilated and unventihted dou-ble skin facade were presented.

  9. ChEVAS: Combining Suprarenal EVAS with Chimney Technique

    International Nuclear Information System (INIS)

    Endovascular sealing with the Nellix® endoprosthesis (EVAS) is a new technique to treat infrarenal abdominal aortic aneurysms. We describe the use of endovascular sealing in conjunction with chimney stents for the renal arteries (chEVAS) in two patients, one with a refractory type Ia endoleak and an expanding aneurysm, and one with a large juxtarenal aneurysm unsuitable for fenestrated endovascular repair (EVAR). Both aneurysms were successfully excluded. Our report confirms the utility of chEVAS in challenging cases, where suprarenal seal is necessary. We suggest that, due to lack of knowledge on its durability, chEVAS should only been considered when more conventional treatment modalities (open repair and fenestrated EVAR) are deemed difficult or unfeasible

  10. Marketable solar chimney passive solar system components: research and development

    Energy Technology Data Exchange (ETDEWEB)

    De Pascali, P.; Andreotti, P.; Scudo, G.; Silingardi, A.; Gabbi, L.; Grasselli, C.; Cattivelli, F.; Farruggia, S.; Giannotti, A.M. (Ist. Cooperativo per l' Innovazione, Rome (Italy); Milan Politecnico (Italy); Coopsette scrl, Castelnovo Sotto (Italy))

    1989-02-01

    The report describes research to develop a marketable passive solar system incorporating a solar chimney in which heated air rises and produces a natural convection air flow within a double envelope construction. The equipment consists of a heat capturing element, another element to distribute and accumulate heat and a control system. Research activities involved: the study of feasible configurations and performance requirements; the design of a selected configuration; a computerized simulation of the system; and the development of two prototype modules to be lab tested at a facility equipped with real time data acquisition systems. The coordinated effort strove to obtain a multi-use system capable of providing summer cooling, as well as, winter heating and a system which would be accepted by both the construction industry and potential home buyers.

  11. Upstream petroleum industry flaring and venting report : industry performance for year ending December 31, 2001

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-07-01

    Solution gas, gas from oil and bitumen batteries, is the largest source of flaring and venting in Alberta. A summary of solution gas conserved, flared and vented in Alberta during the year ending December 31, 2001 was presented along with flared volumes for the various oil and gas industry sectors such as gas plants, gas gathering systems, well tests and oil, bitumen and gas batteries. The report identifies the sources of flaring and venting in Alberta and monitors the progress the industry has made in reducing the volume of solution gas flared since 1996. Operators were ranked provincially, as well as within each field centre of the Alberta Energy and Utilities Board, based on solution gas flared, vented, total solution gas produced, and total oil from crude oil and bitumen batteries. The report demonstrates the significant progress industry has made towards reducing solution flare gas and vent volumes in the province. In 2001, the industry decreased overall flared and vented volumes by 16 per cent compared to year 2000 from all sources. Two new tables in this year's report indicate the top 25 solution gas producers in Alberta and the top 25 companies venting solution gas. The table provides information regarding each company's conservation performance and production volumes as a percentage of the provincial total.

  12. Finite Element Analysis and Linear Regression of Maximum Temperature for Inner Wall of Chimney Foundation

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The uniform design method was adopted and the twenty-four groups of different geometric and physical parameters were chosen. The finite element model was built. Comparisons between the simulation results and the test results prove that the simulation results are correct. The distribution of the temperature field of the chimney foundation was analyzed. The multivariate linear regression of the hightest tomperature was performed on the inner wall of the chimney foundation by the numerical calculated results. The fitting property of the highest temperature with six influence factors was obtained. A simple method for the calculation of the temperature field of the chimney foundation was provided.

  13. Hydrothermal Vents at 5000m on the Mid-Cayman Rise: The Deepest and Hottest Hydrothermal Systems Yet Discovered!

    Science.gov (United States)

    Murton, B. J.; Connelly, D. P.; Copley, J. T.; Stansfield, K. L.; Tyler, P. A.; Cruise Jc044 Sceintific Party

    2010-12-01

    This contribution describes the geological setting of hydrothermal activity within the Mid- Cayman Rise (MCR) using data acquired during cruise JC044 (MAR-APR 2010) from the deep-towed sidescan sonar TOBI, AUV Autosub6000 and the ROTV HyBIS. The 110 km-long Mid- Cayman Rise (MCR), located within Caribbean Sea, is the deepest spreading centre known, reaching over 6000m. Hence it poses an end-member of extreme depth for hydrothermal circulation. Accretion of new volcanic crust is focused within two ridge segments, to the north and south of a centrally located massif of peridotite and gabbro. Following earlier indications of hydrothermal plumes (German et al., in 2009), we discovered two high-temperature hydrothermal system: one at a depth of 5000m in the neovolcanic zone of the northern segment, and another at 2300m on the flanks of the MCR. These sites show contrasting styles of fluid venting, mineralisation, geological setting and host rock interaction. At 5000m-depth, the ultra-deep vent site forms the deepest hydrothermal system known. Venting is focused at the western side of a 100m diameter, 30m high mound, while inactive sulphides extend eastwards for at least 800m. Fluids discharge from clusters of chimneys whose location is related to basement faults. Changes in salinity in the venting fluids indicate discharge of a low salinity phase and a brine phase. At 500bar, this is definitive evidence for supercritical fluid emission. We also found the sulphide mineralization to be copper-rich, giving a characteristic green hue to many of the deposits, probably a result of the super-critical state of the vent fluids. A prominent axial volcanic ridge nearby indicates a robust magma supply to the northern MCR segment. Thus it is likely the ultra-deep vent site derives its thermal energy from magmatic sources, similar to those thought to underlie other slow-spreading ridge volcanic-hosted vent sites (e.g. Broken Spur: MAR). The shallower (2300m) MCR hydrothermal vent

  14. Adaptations to Hydrothermal Vent Life in Kiwa tyleri, a New Species of Yeti Crab from the East Scotia Ridge, Antarctica.

    Directory of Open Access Journals (Sweden)

    Sven Thatje

    Full Text Available Hydrothermal vents in the Southern Ocean are the physiologically most isolated chemosynthetic environments known. Here, we describe Kiwa tyleri sp. nov., the first species of yeti crab known from the Southern Ocean. Kiwa tyleri belongs to the family Kiwaidae and is the visually dominant macrofauna of two known vent sites situated on the northern and southern segments of the East Scotia Ridge (ESR. The species is known to depend on primary productivity by chemosynthetic bacteria and resides at the warm-eurythermal vent environment for most of its life; its short-range distribution away from vents (few metres is physiologically constrained by the stable, cold waters of the surrounding Southern Ocean. Kiwa tylerihas been shown to present differential life history adaptations in response to this contrasting thermal environment. Morphological adaptations specific to life in warm-eurythermal waters, as found on - or in close proximity of - vent chimneys, are discussed in comparison with adaptations seen in the other two known members of the family (K. hirsuta, K. puravida, which show a preference for low temperature chemosynthetic environments.

  15. Analytical study of the closure flow inside the ETRR-2 core chimney

    Energy Technology Data Exchange (ETDEWEB)

    El-Din El-Morshdy, S. [Atomic Energy Authority, Cairo (Egypt). Reactors Dept.

    2006-12-15

    The present work is carried out in order to study the closure flow inside the core chimney of the Egypt second research reactor (ETRR-2). Based on the finite difference technique, a two dimensional model is developed to simulate the coolant flow inside the chimney. The model is verified by FEHT finite element program. Then a study of different closure flow values inside the chimney was made using the developed model where a flow map is plotted showing the stagnation depth for each closure flow. The flow map shows that for a closure flow greater than 0.16 m{sup 3}/h, no active water ascends from the core to the pool through the chimney. The model results are analyzed and discussed. (orig.)

  16. Analytical study of the closure flow inside the ETRR-2 core chimney

    Energy Technology Data Exchange (ETDEWEB)

    El-Morshdy, Salah El-Din [Reactors Department, Atomic Energy Authority, Cairo (Egypt)]. E-mail: selmorshedy@etrr2-aea.org.eg

    2007-03-15

    The present work is carried out in order to study the closure flow inside the core chimney of the Egypt second research reactor (ETRR-2). Based on the finite difference technique, a two dimensional model is developed to simulate the coolant flow inside the chimney. The model is verified by FEHT finite element program. Then a study of different closure flow values inside the chimney was made using the developed model where a flow maps is plotted showing the stagnation depth for each closure flow. The flow maps shows that for a closure flow greater than 0.16 m{sup 3}/h, no radioactive water ascends from the core to the pool through the chimney. The model results are analyzed and discussed.

  17. Modelling and simulation of condensation phenomena of acid gases in an industrial chimney

    OpenAIRE

    Serris, Eric; Cournil, Michel; Peultier, Jérôme

    2007-01-01

    Coal power stations as well as waste incinerators produce humid acid gases which condensate in industrial chimneys. These condensates may cause corrosion of the internal cladding made of stainless steels, nickel base alloys or non metallic materials. In the aim of polluting emission reduction and material optimal choice, it is necessary to determine all the phenomena which occur throughout the chimney such as condensation and dissolution of acid gases (in this particular case, sulphur dioxide...

  18. Basement Kind Effects on Air Temperature of a Solar Chimney in Baghdad - Iraq Weather

    OpenAIRE

    Miqdam Tariq Chaichan

    2011-01-01

    A solar updraft tower power plant (solar tower) is a solar thermal power plant that utilizes a combination of solar air collector and central updraft tube to generate an induced convective flow which drives pressure staged turbines to generate electricity. This paper presents practical results of a prototype of a solar chimney with thermal mass, where the glass surface is replaced by transparence plastic cover. The study focused on chimney's basements kind effect on collected air temperatur...

  19. Cement penetration after patella venting.

    Science.gov (United States)

    Jones, Christopher W; Lam, Li-On; Butler, Adam; Wood, David J; Walsh, William R

    2009-01-01

    There is a high rate of patellofemoral complications following total knee arthroplasty. Optimization of the cement-bone interface by venting and suction of the tibial plateau has been shown to improve cement penetration. Our study was designed to investigate if venting the patella prior to cementing improved cement penetration. Ten paired cadaver patellae were allocated prior to resurfacing to be vented or non-vented. Bone mineral density (BMD) was measured by DEXA scanning. In vented specimens, a 1.6 mm Kirschner wire was used to breach the anterior cortex at the center. Specimens were resurfaced with standard Profix instrumentation and Versabond bone cement (Smith and Nephew PLC, UK). Cement penetration was assessed from Faxitron and sectioned images by a digital image software package (ImageJ V1.38, NIH, USA). Wilcoxon rank sum test was used to assess the difference in cement penetration between groups. The relationship between BMD and cement penetration was analyzed by Pearson correlation coefficient. There was a strong negative correlation between peak BMD and cement penetration when analyzed independent of experimental grouping (r(2)=-0.812, p=0.004). Wilcoxon rank sum testing demonstrated no significant difference (rank sum statistic W=27, p=0.579) in cement penetration between vented (10.53%+/-4.66; mean+/-std dev) and non-vented patellae (11.51%+/-6.23; mean+/-std dev). Venting the patella using a Kirschner wire does not have a significant effect on the amount of cement penetration achieved in vitro using Profix instrumentation and Versabond cement. PMID:19010682

  20. The Balkan Theme in The Secret of Chimneys

    Directory of Open Access Journals (Sweden)

    Graham St. John Stott

    2016-06-01

    Full Text Available In The Secret of Chimneys (1925 Agatha Christie uses the all too familiar Balkan stereotypes of backwardness and brigandage, but not – as was usually the case at the time – as an Other to illustrate British virtue, but as a mirror to British vice. It is Britain, not the fictional Herzoslovakia, that is a nation of brigands. Herzoslovakia remains relatively unknown, as none of the novel’s scenes take place there, but it is described by disinterested observers as democratic and prosperous. In London, however, the Foreign Office plans to overthrow its government to secure oil rights promised by a royal heir-in-exile to a London-based financial consortium. Keywords: Christie, Balkans, Romania, oil, brigandsAgatha Christie’s The Secret of Chimneys (1925 has been faulted for being on the one hand a frothy mix of Anthony Hope and P. G. Wodehouse (Thompson 143 and on the other a mishmash of popular ethnic, national and regional stereotypes – including those of the Balkans (Todorova 122. It is, however, a far more subtle work than such accounts suggest. Though the influence of Hope and Wodehouse can certainly be seen in the novel’s story of princes in disguise (reminiscent of The Prisoner of Zenda and a country house setting that would have reminded readers of Blandings, its main plot addresses an important theme –and in exploring it Christie takes the Balkans very seriously. Oil has been found in the Republic of Herzoslovakia and the Foreign Office, represented by George Lomax, has secured the pledge of the exiled Prince Michael Obolovitch “to grant certain oil concessions” to a consortium led by Herman Isaacstein if the Obolovitchs are restored to power. In other words: to secure those concessions the British Government has committed itself to the overthrow of Herzoslovakia’s government. The Foreign Office’s interest in the Balkans might not have surprised Christie’s readers. The Anglo-Iranian Oil Company had held a monopoly on

  1. Effect of cold inflow on chimney height of natural draft cooling towers

    International Nuclear Information System (INIS)

    Highlights: ► Natural convection data were obtained from an air-cooled heat exchanger model. ► The extent of cold inflow was quantified to relate to the decrease in effective chimney height. ► Installation of wire mesh screen on chimney outlet blocked off cold inflow to improve the chimney efficiency. ► Evidence of existence of effective plume-chimney for when cold inflow was blocked off warrants further work. - Abstract: Temperature and pressure drop data obtained from an air-cooled heat exchanger model with cross-sectional flow areas of 0.56 m2, 1.00 m2 and 2.25 m2 operating under natural convection are presented that indicate significant cold inflow, resulting in the reduction of effective chimney height. Cold inflows encountered in actual applications where the Froude number is typically 0.2, may not be as severe as described in this paper, which was of the order of 10−6–10−4. Additional tests on smaller scale models appeared to favor the explanation that the occurrence of cold inflow in the air-cooled heat exchanger model was primarily due to the relative ease in either drawing cold air from inlet or from outlet, and to a lesser extent the Froude number of the chimney or the critical velocity estimated by formula. A CFD study will bring much understanding of the phenomenon for the different situations.

  2. Modeling and characteristics analysis of hybrid cooling-tower-solar-chimney system

    International Nuclear Information System (INIS)

    Highlights: • A 3-D model for hybrid cooling-tower-solar-chimney system is developed. • The inclusion of heat exchangers into solar chimney boosts the power output. • The huge jump in power output is at the expense of heat dissipation capacity. • The heat exchanger as second heat source has greater impact on system performance. - Abstract: The hybrid cooling-tower-solar-chimney system (HCTSC), combining solar chimney with natural draft dry cooling tower, generates electricity and dissipates waste heat for the coupled geothermal power plant simultaneously. Based on a developed 3-D model, performance comparisons between the HCTSC system, solar chimney and natural draft dry cooling tower were performed in terms of power output of turbine and heat dissipation capacity. Results show that compared to the traditional solar chimney with similar geometric dimensions, HCTSC system can achieve over 20 times increase in the power output of turbine. However, this huge jump in power output is at the expense of heat dissipation capacity, which may lead to the malfunction of the coupled thermal power plant. By increasing the heat transfer area of the heat exchanger, the HCTSC system can manage to recover its heat dissipation capacity

  3. Experimental study of the resulting flow of plume-thermosiphon interaction: application to chimney problems

    Energy Technology Data Exchange (ETDEWEB)

    Zinoubi, J.; Maad, R.B.; Belghith, A. [Faculte des Sciences de Tunis, Tunis (Tunisia). Departement de Physique, Laboratoire d' Energetique et des Transferts de Chaleur et de Masse

    2005-03-01

    The quality of the surrounding air depends on the various dismissals of the combustion gases (exhaust cars, smokes of chimneys, ...), their scattering in the environment. Urban development around industrial zones and overexploitation of lands near factories triggered responsible interest in the problem of pollution. In order to decrease the impact of air pollution, several chimneys have been constructed in the different industrial facilities. So the improvement of the industrial chimney range became one of the current research problems. In order to improve the industrial chimney efficiency and to increase the vertical scattering of combustion products, we studied a system that could be integrated to the industrial chimney exit. This system is essentially constituted of an open-ended vertical cylinder of larger diameter. Thermal radiance emitted by smoke heats the internal cylinder wall. The heating of the fluid at the cylinder-inlet is the cause of the thermosiphon effect around the thermal plume. To study the problem in the laboratory we simulated the plume exiting of a chimney by a disk heated uniformly by the Joule effect at constant temperature. Different configurations were studied, while acting, on the source-cylinder spacing and the cylinder height. The study of the average fields permits, in a first stage, to get better information about the mechanism of the resulting flow development, and in a second stage, to determine the spacing of the source-cylinder and cylinder height optima, for which a clean increase of fluid flow rate is obtained. (author)

  4. Vente d'artisanat

    CERN Multimedia

    Staff Associaiton

    2014-01-01

      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...

  5. Beautiful heat: a master chimney sweep talks about burning issues

    Energy Technology Data Exchange (ETDEWEB)

    Hederich, M.P.

    2001-07-01

    Fire has played a major role in mankind's life from the beginning. Used for heating and cooking, its various uses have evolved to include controlled explosions shortly after the development of gunpowder, and the generation of electricity made other uses possible. The author, a certified solid fuel technician and chimney sweep, as well as a licensed technician for natural gas and propane, has written this book to enable the reader to enjoy safe and dependable wood fires year round by taking the necessary steps. The first recommendation made is against the homeowner installing himself/herself any solid fuel system. It is a job better left to the professionals, considering the substantial product and regulation knowledge and experience required. Specific information related to solid fuel burning technology is included in this book, to be used as a guide. Part 1 of the book deals with the fuel, touching on issues such as energy and the environment, wood combustion and air pollution, buying firewood, wood ashes, cleaning your heating system and others. Part 2 is devoted to the heating system. It introduces topics ranging from the systems advisor to the location and installation of the system, the principles of space heating, high efficiency wood burning, inspections, to name just a few. 22 refs., tabs., figs.

  6. Experimental Study Using the Passive Solar Chimney for Evaporative Cooling With PCM and CFM as a Thermal Energy Storage

    Directory of Open Access Journals (Sweden)

    Talib K. Murtadha

    2016-09-01

    Full Text Available In this work, a test room was built in Baghdad city, with (2*1.5*1.5 m3 in dimensions, while the solar chimneys (SC were designed with aspect ratio (ar bigger than 12. Test room was supplied by many solar collectors; vertical single side of air pass with ar equals 25, and tilted 45o double side of air passes with ar equals 50 for each pass, both collectors consist of flat thermal energy storage box collector (TESB that covered by transparent clear acrylic sheet, third type of collector is array of evacuated tubular collectors with thermosyphon in 45o instelled in the bottom of TESB of vertical SC. The TESB was made from metallic iron sheets as a shell and fuelled by paraffin wax as phase change material (PCM. The PCM supported by copper foam matrix (CFM to enhance thermal conductivity of wax. When heat is released from TESB to the air, a buoyancy force will be generated in chimney gaps. Then a difference in pressure between inside and outside test room leads to induce the air flow to test room through wet corrugated cellulose pad, where evaporative cooling (EC occurs. Results of experimental work, that achieved in June, for 12 to24 hour in the test day, refer to effectiveness using EC to decrease the room temperature comparing. The system reduces test room temperature of up to 8.5~9.2 oC in 11:00 am to 3:00 pm and at highest effectiveness of EC, while minimum reduces in temperature of up to 3.5 oC in 8:00pm to 3:00 am. Also, the results showed the affectivity to using the TESB, during the night time for ventilation and EC, with lower effectiveness than from day time. The range of EC effectiveness equals 30.5-37.5 with a natural vent, while The maximum air change per hour (ACH equals (3.8-6.187, and the maximum mass flow rate is equal to (36.651 kg.hr-1 at experimental evaluation of the system’s discharge coefficient value 0.371.

  7. Iron-Oxidizing Bacteria Found at Slow-Spreading Ridge: a Case Study of Capelinhos Hydrothermal Vent (Lucky Strike, MAR 37°N)

    Science.gov (United States)

    Henri, P. A.; Rommevaux, C.; Lesongeur, F.; Emerson, D.; Leleu, T.; Chavagnac, V.

    2015-12-01

    Iron-oxidizing bacteria becomes increasingly described in different geological settings from volcanically active seamounts, coastal waters, to diffuse hydrothermal vents near seafloor spreading centers [Emerson et al., 2010]. They have been mostly identified and described in Pacific Ocean, and have been only recently found in hydrothermal systems associated to slow spreading center of the Mid-Atlantic Ridge (MAR) [Scott et al., 2015]. During the MoMARSAT'13 cruise at Lucky Strike hydrothermal field (MAR), a new hydrothermal site was discovered at about 1.5 km eastward from the lava lake and from the main hydrothermal vents. This active venting site, named Capelinhos, is therefore the most distant from the volcano, features many chimneys, both focused and diffuses. The hydrothermal end-member fluids from Capelinhos are different from those of the other sites of Lucky Strike, showing the highest content of iron (Fe/Mn≈3.96) and the lowest chlorinity (270 mmol/l) [Leleu et al., 2015]. Most of the chimneys exhibit rust-color surfaces and bacterial mats near diffuse flows. During the MoMARSAT'15 cruise, an active chimney, a small inactive one, and rust-color bacterial mat near diffuse flow were sampled at Capelinhos. Observations by SEM of the hydrothermal samples revealed the presence of iron oxides in an assemblage of tubular "sheaths", assembled "stalks", helical "stalks" and amorphous aggregates. These features are similar to those described from the Loihi iron-mats deposits and argue for the occurrence of iron-oxidizing bacteria. Cultures under micro-aerobic and neutral pH conditions allowed us to isolate strains from the small inactive chimney. Pyrosequencing of the 16S rRNA gene of the isolates and environmental samples will soon be performed, which should confirm the presence of iron-oxidizing bacteria and reveal the organization of bacterial communities in this original and newly discovered hydrothermal site of the slow spreading Mid-Atlantic Ridge. Emerson

  8. Functional interactions among filamentous Epsilonproteobacteria and Bacteroidetes in a deep-sea hydrothermal vent biofilm.

    Science.gov (United States)

    Stokke, Runar; Dahle, Håkon; Roalkvam, Irene; Wissuwa, Juliane; Daae, Frida Lise; Tooming-Klunderud, Ave; Thorseth, Ingunn H; Pedersen, Rolf B; Steen, Ida Helene

    2015-10-01

    Little is known about how lithoautotrophic primary production is connected to microbial organotrophic consumption in hydrothermal systems. Using a multifaceted approach, we analysed the structure and metabolic capabilities within a biofilm growing on the surface of a black smoker chimney in the Loki's Castle vent field. Imaging revealed the presence of rod-shaped Bacteroidetes growing as ectobionts on long, sheathed microbial filaments (> 100 μm) affiliated with the Sulfurovum genus within Epsilonproteobacteria. The filaments were composed of a thick (> 200 nm) stable polysaccharide, representing a substantial fraction of organic carbon produced by primary production. An integrated -omics approach enabled us to assess the metabolic potential and in situ metabolism of individual taxonomic and morphological groups identified by imaging. Specifically, we provide evidence that organotrophic Bacteroidetes attach to and glide along the surface of Sulfurovum filaments utilizing organic polymers produced by the lithoautotrophic Sulfurovum. Furthermore, in situ expression of acetyl-CoA synthetase by Sulfurovum suggested the ability to assimilate acetate, indicating recycling of organic matter in the biofilm. This study expands our understanding of the lifestyles of Epsilonproteobacteria in hydrothermal vents, their metabolic properties and co-operative interactions in deep-sea hydrothermal vent food webs.

  9. Mineralization of a Proterozoic Sulfide Black Smoker Chimney and Thermophilous Microorganisms in Eastern Hebei, China

    Institute of Scientific and Technical Information of China (English)

    XIA Xuehui; LIAN Wei; YUAN Congjian; YAN Fei; YUAN Jiazhong

    2008-01-01

    A sulfide black smoker chimney exists in the Gaobanhe seabed exhalation massive sulfidedeposit in the Xinglong-Kuancheng secondary fault basin of the Proterozoic Yanliao rift trough inHebei Province, taking the shape of mounds, individually about 2-3 cm high. Abundant fossils ofthermophilous bacteria and algae in perfect preservation are found in the ore surrounding the blacksmoker chimney. Scanning electron microscopy (SEM) and molecular biomarker studies on themicroorganismal ore fabric show that the microorganism in the sulfide ore is in fact a sedimentaryproduct of probiotic bacteria and algae. In the special food chain based on black smoker chimney atancient seabed- thermophilous bacteria, the thermophilons bacteria and algae reproduce in largequantity. Intermittently erupting of fluid from the chimney creats conditions for formation of sulfidedeposit. In the process of exhalation action of hot fluid, thermophilous bacteria and algae grow andreproduce around the sulfide black smoker chimney, absorbing mineralizing substances brought bythe fluid. Massive sulfide deposits are formed in this process of absorption of seabed black smokerchimney exhalation-mineralizing fluid puisation.thermophilous microorganism.

  10. An analytical and numerical study of solar chimney use for room natural ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Bassiouny, Ramadan; Koura, Nader S.A. [Department of Mechanical Power Engineering and Energy, Minia University, Minia 61111 (Egypt)

    2008-07-01

    The solar chimney concept used for improving room natural ventilation was analytically and numerically studied. The study considered some geometrical parameters such as chimney inlet size and width, which are believed to have a significant effect on space ventilation. The numerical analysis was intended to predict the flow pattern in the room as well as in the chimney. This would help optimizing design parameters. The results were compared with available published experimental and theoretical data. There was an acceptable trend match between the present analytical results and the published data for the room air change per hour, ACH. Further, it was noticed that the chimney width has a more significant effect on ACH compared to the chimney inlet size. The results showed that the absorber average temperature could be correlated to the intensity as: (T{sub w} = 3.51I{sup 0.461}) with an accepted range of approximation error. In addition the average air exit velocity was found to vary with the intensity as ({nu}{sub ex} = 0.013I{sup 0.4}). (author)

  11. Numerical simulation of turbulent flow mixing inside a square chimney structure of a research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, S.; Bhatnagar, A. [Bhabha Atomic Research Centre, Mumbai (India). Research Reactor Design and Projects Div.; Vijayan, P.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Engineering Div.; Singh, R.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Safety Div.; Raina, V.K. [Bhabha Atomic Research Centre, Mumbai (India). Reactor Group

    2013-11-15

    Numerical simulation was performed to study the turbulent mixing behavior of two opposing flows inside a square chimney structure of a research reactor. The chimney design facilitates drawing pool water in the downward direction and thereby suppresses the upward flow of radioactive water jet to limit the radiation field at the reactor pool top. Analyses were carried out considering a mass flow rate of 750 kg/s for the upward flowing hot water from the core, which corresponds to Reynolds number of 3 x 10{sup 6}. Mass flow ratios of the downward flow and the upward flow were 0.0, 0.05, 0.1 and 0.15. The effects of mass flow ratio, chimney height on the velocity and temperature distribution inside three-dimensional chimney structure was evaluated using CFD code PHOENICS. The effect of temperature difference between the opposing flows on velocity was also analysed. It is observed that increase in downward flow causes the jet height to decrease due to the opposing momentum of downward flow against the upward jet. The effects of chimney height and temperature difference on the jet height are found to be marginal because of dominating inertial force over buoyancy force for the study. (orig.)

  12. Safety Testing of Left Ventricular Vent Valves

    OpenAIRE

    Gavin, Caroline; Coblentz, John; Acsell, Jeffrey R.; Shackelford, Anthony G.; Sistino, Joseph J.

    2015-01-01

    Vent vacuum relief valves (VRVs) are used to limit the negative pressure at the ventricular vent catheter tip as well as prevent reversal of blood flow and prevention of air embolism. The purpose of this study was to evaluate the performance of three commercially available ventricular vent valves. The negative pressure at which the vent valve opened was measured at the valve inlet using high-fidelity pressure transducers. Also, the flow rate at which air entrainment occurred due to valve open...

  13. Venting of gas deflagrations through relief pipes

    OpenAIRE

    Ferrara, Gabriele

    2006-01-01

    Vent devices for gas and dust explosions are often ducted to safety locations by means of relief pipes for the discharge of hot combustion products or blast waves (NFPA 68, 2002). The presence of the duct is likely to increase the severity of the explosion with respect to simply vented vessels posing a problem for the proper design of this venting configuration. The phenomenology of the vented explosion is complicated as the interaction of combustion in the duct with primary combustion in...

  14. 40 CFR 63.7885 - What are the general standards I must meet for my affected process vents?

    Science.gov (United States)

    2010-07-01

    ... vent is also subject to another subpart under 40 CFR part 61 or 40 CFR part 63, you control emissions... conditions (as defined in 40 CFR 63.2); or (ii) The process vent stream flow rate is less than 6.0 m3/min at standard conditions (as defined in 40 CFR 63.2) and the total concentration of HAP listed in Table 1...

  15. New energy from an old chimney; Nieuwe energie uit een oude schoorsteen

    Energy Technology Data Exchange (ETDEWEB)

    Van Goch, T.A.J. [BAM Techniek, Benningbroek (Netherlands)

    2013-07-15

    A new purpose has been found for the unused monumental stack chimney at the Eindhoven University of Technology. The idea is to use the chimney to provide free cooling. Using advanced simulation and analysis methods, the feasibility of the concept was studied. The results show that it is indeed possible to use the chimney effectively to provide free cooling to the neighbouring Ceres (Central Energy and Control Station) building [Dutch] De ongebruikte monumentale schoorsteen van de Universiteit Eindhoven is nieuw leven ingeblazen door hem in te zetten voor vrije koeling. Een studie naar de haalbaarheid hiervan is uitgevoerd met behulp vangeavanceerde simulatie en analysetechnieken. Het is gebleken dat de schoorsteen inderdaad effectief kan worden ingezet voor het leveren van koeling aan het naastgelegen Ceres (Centraal Energie en Regelstation) gebouw.

  16. Fenestrated and Chimney Technique for Juxtarenal Aortic Aneurysm: A Systematic Review and Pooled Data Analysis

    Science.gov (United States)

    Li, Yue; Hu, Zhongzhou; Bai, Chujie; Liu, Jie; Zhang, Tao; Ge, Yangyang; Luan, Shaoliang; Guo, Wei

    2016-01-01

    Juxtarenal aortic aneurysms (JAA) account for approximately 15% of abdominal aortic aneurysms. Fenestrated endovascular aneurysm repair (FEVAR) and chimney endovascular aneurysm repair (CH-EVAR) are both effective methods to treat JAAs, but the comparative effectiveness of these treatment modalities is unclear. We searched the PubMed, Medline, Embase, and Cochrane databases to identify English language articles published between January 2005 and September 2013 on management of JAA with fenestrated and chimney techniques to conduct a systematic review to compare outcomes of patients with juxtarenal aortic aneurysm (JAA) treated with the two techniques. We compared nine F-EVAR cohort studies including 542 JAA patients and 8 CH-EVAR cohorts with 158 JAA patients regarding techniques success rates, 30-day mortality, late mortality, endoleak events and secondary intervention rates. The results of this systematic review indicate that both fenestrated and chimney techniques are attractive options for JAAs treatment with encouraging early and mid-term outcomes. PMID:26869488

  17. 33 CFR 159.61 - Vents.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  18. A Semi-Empirical Model for Tilted-Gun Planar Magnetron Sputtering Accounting for Chimney Shadowing

    Science.gov (United States)

    Bunn, J. K.; Metting, C. J.; Hattrick-Simpers, J.

    2015-01-01

    Integrated computational materials engineering (ICME) approaches to composition and thickness profiles of sputtered thin-film samples are the key to expediting materials exploration for these materials. Here, an ICME-based semi-empirical approach to modeling the thickness of thin-film samples deposited via magnetron sputtering is developed. Using Yamamura's dimensionless differential angular sputtering yield and a measured deposition rate at a point in space for a single experimental condition, the model predicts the deposition profile from planar DC sputtering sources. The model includes corrections for off-center, tilted gun geometries as well as shadowing effects from gun chimneys used in most state-of-the-art sputtering systems. The modeling algorithm was validated by comparing its results with experimental deposition rates obtained from a sputtering system utilizing sources with a multi-piece chimney assembly that consists of a lower ground shield and a removable gas chimney. Simulations were performed for gun-tilts ranging from 0° to 31.3° from the vertical with and without the gas chimney installed. The results for the predicted and experimental angular dependence of the sputtering deposition rate were found to have an average magnitude of relative error of for a 0°-31.3° gun-tilt range without the gas chimney, and for a 17.7°-31.3° gun-tilt range with the gas chimney. The continuum nature of the model renders this approach reverse-optimizable, providing a rapid tool for assisting in the understanding of the synthesis-composition-property space of novel materials.

  19. Chimney and periscope technique for emergent treatment of spontaneous aortic rupture.

    Science.gov (United States)

    Trellopoulos, George; Georgakarakos, Efstratios; Pelekas, Dimitrios; Papachristodoulou, Athanasia; Argyriou, Christos; Georgiadis, George S

    2014-07-01

    Aortic rupture comprises a potentially fatal condition necessitating emergent treatment. Endovascular sealing of the rupture site is often combined with the use of chimney- and periscope stent placement to preserve perfusion of aortic branches. We present a case of successful endovascular management of contained aortic rupture in a 78-year-old patient. The left brachial access facilitated stenting of the celiac and superior mesenteric arteries, whereas the left femoral route served stenting of the renal artery. One-month follow-up confirmed complete sealing, stent patency, and absence of endograft migration. The combined periscope and chimney technique is feasible and effective in the emergency setting. PMID:24517987

  20. Structural Integrity Evaluation of an New In-Chimney Bracket Structures for HANARO

    International Nuclear Information System (INIS)

    In HANARO are there provided three hexagonal irradiation holes (CT, IR1 and IR2) in the central region of the core while four circular irradiation holes (OR3 ∼ OR6) in the outer core. There exist two types of irradiation facilities: uninstrumented or instrumented. The uninstrumented irradiation facility is little influenced by the coolant flow. But the dynamic behavior by the flow-induced vibration (FIV) and seismic loads is expected to largely occur in case of the instrumented test facility due to the long guide tube to protect the instrumentation cables. To suppress this dynamic behavior of the facility, the in-chimney bracket was designed. As a supplementary supporting structure for irradiation facility, this bracket will hold guide tubes whose holding position of the instrumented facility in CT or IR is the middle part of the instrumented facility between the hole spider and the robot arm already provided in the reactor pool liner. On the while, the bracket will grip the upper part of the guide tube when it is applied to hold the instrumented facility loaded in OR sites. Therefore it is believed that the irradiation test can be successfully conducted since this bracket can reduce the FIV and dynamic response to seismic load as well. In new in-chimney bracket, IR1 is reserved for IPS(In-Pile Section) so only CT/IR2 guide tubes are supported by CT/IR clamp units and the shape of In-chimney bracket is redesigned. For evaluating the structural integrity on the new in-chimney bracket and related reactor structures, ANSYS finite element analysis model is developed and the dynamic characteristics are analyzed. The seismic response analyses of new in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of OBE(0.1g) and SSE(0.2g) are performed. The response shows that the stress values for main points on the reactor structures and the new in-chimney bracket for seismic loads are within the ASME Code limits. It is

  1. Numerical analysis of the hemodynamics of an abdominal aortic aneurysm repaired using the endovascular chimney technique.

    Science.gov (United States)

    Ben Gur, Hila; Kosa, Gabor; Brand, Moshe

    2015-08-01

    This paper presents a numerical analysis of the hemodynamics in an abdominal aorta (AA) with an aneurysm repaired by a stent graft (SG) system using the chimney technique. Computational fluid dynamics (CFD) simulations were conducted in a model of an AA repaired with a chimney stent graft (CSG) inserted into a renal artery parallel to an aortic SG and a model of a healthy AA. Comparing the simulation results of these two cases suggests that the presence of the CSG in the AA causes changes in average wall shear stress (WSS), potentially damaging recirculation zones, and additional changes in flow patterns. PMID:26736427

  2. On the form of the power equation for modeling solar chimney power plant systems

    CERN Document Server

    Fathi, Nima; Vorobieff, Peter

    2015-01-01

    Recently several mathematical models of a solar chimney power plant were derived, studied for a variety of boundary conditions, and compared against CFD calculations. The importance of these analyses is about the accuracy of the derived pressure drop and output power equation for solar chimney power plant systems (SCPPS). We examine the assumptions underlying the derivation and present reasons to believe that some of the derived equations, specifically the power equation in this model, may require a correction to be applicable in more realistic conditions. The analytical resutls are compared against the available experimental data from the Manzanares power plant.

  3. First Active Hydrothermal Vent Fields Discovered at the Equatorial Southern East Pacific Rise

    Science.gov (United States)

    Tao, C.; Lin, J.; Wu, G.; German, C. R.; Yoerger, D. R.; Chen, Y. J.; Guo, S.; Zeng, Z.; Han, X.; Zhou, N.; Li, J.; Xia, S.; Wang, H.; Ding, T.; Gao, S.; Qian, X.; Cui, R.; Zhou, J.; Ye, D.; Zhang8, Y.; Zhang, D.; Li, L.; Zhang, X.; Li, Y.; Wu, X.; Li, S.; He, Y.; Huang, W.; Wang, Y.; Wang, T.; Li, X.; Wang, K.; Gai, Y.; Science Party, D.; Baker, E. T.; Nakamura14, K.

    2008-12-01

    The third leg of the 2008 Chinese DY115-20 expedition on board R/V Dayangyihao has successfully discovered, for the first time, active hydrothermal vent fields on the fast-spreading Southern East Pacific Rise (SEPR) near the equator. This expedition follows the work of a 2005 expedition by R/V Dayangyihao, during which water column turbidity anomalies were measured in the region. The newly discovered vent fields are located along a 22-km-long ridge segment of the SEPR at 102.655°W/2.22°S, 102.646°W/2.152°S, 102.619°W/2.078°S, and 102.62°W/2.02°S, respectively, as well as on an off-axial volcano near 102.456°W/1.369°S. A significant portion of the activity appears to be concentrated along the edges of a seafloor fissure system. Furthermore, water column turbidity anomalies were observed over off-axis volcanoes near 102.827°W/2.084°S and 102.58°W/2.019°S. Video footage of the vent fields and water column turbidity, temperature, and methane anomalies were recorded by a deep-towed integrated system consisting of video, still camera, CTD, and ADCP, and MAPR and METS sensors. Two active hydrothermal fields at 2.217°S and 2.023°S were then extensively photographed and surveyed using the autonomous underwater vehicle ABE of the Woods Hole Oceanographic Institution (WHOI). Four samples of hydrothermal chimneys were successfully obtained by a TV-guided grab in three locations, showing evidence of high-temperature hydrothermal venting.

  4. Nonlinear mushy-layer convection with chimneys: stability and optimal solute fluxes

    CERN Document Server

    Wells, Andrew J; Orszag, Steven A

    2012-01-01

    We model buoyancy-driven convection with chimneys -- channels of zero solid fraction -- in a mushy layer formed during directional solidification of a binary alloy in two-dimensions. A large suite of numerical simulations is combined with scaling analysis in order to study the parametric dependence of the flow. Stability boundaries are calculated for states of finite-amplitude convection with chimneys, which for a narrow domain can be interpreted in terms of a modified Rayleigh number criterion based on the domain width and mushy-layer permeability. For solidification in a wide domain with multiple chimneys, it has previously been hypothesised that the chimney spacing will adjust to optimise the rate of removal of potential energy from the system. For a wide variety of initial liquid concentration conditions, we consider the detailed flow structure in this optimal state and derive scaling laws for how the flow evolves as the strength of convection increases. For moderate mushy-layer Rayleigh numbers these flo...

  5. Annual performance analysis of the solar chimney power plant in Sinkiang, China

    International Nuclear Information System (INIS)

    Highlights: • A theoretical model was developed concerning hourly variation of solar radiation. • A limitation on maximum collector radius of an SCPP with a given chimney exists. • Annual performance of a 100 MW SCPP was predicted in hourly interval. • The Hami region is considered suitable for the construction of SCPP. - Abstract: To obtain more accurate prediction of the annual performance of solar chimney power plants (SCPPs), a comprehensive theoretical model is developed by taking into account the hourly variation of solar radiation. The effects of the collector and chimney radii on the power output of the SCPP are analyzed, and the results reveal that a limitation on the maximum collector radius exists for the maximum attainable power output of the SCPP. Then four designs of 100 MW SCPPs with different combinations of collector and chimney radii are proposed and the most cost effective one is chosen from among the four SCPPs. The annual power output of the chosen SCPP in the Hami region is estimated at an interval of 1 h for a whole year. The results indicate that the power generation of SCPP presents obvious seasonal variation. Furthermore, the use of 14% of the unused land in the Hami region for the installation of SCPPs would satisfy the annual power requirement for the whole of the Sinkiang region

  6. Endovascular Aneurysm Sealing for Juxtarenal Aneurysm Using the Nellix Device and Chimney Covered Stents

    NARCIS (Netherlands)

    Dijkstra, Martijn L.; Lardenoye, Jan Willem; van Oostayen, Jacques A.; Zeebregts, Clark J.; Reijnen, Michel M. P. J.

    2014-01-01

    Purpose: To show the feasibility of the Nellix device in conjunction with a chimney technique for treating juxtarenal aneurysms in two patients who were deemed unsuitable for fenestrated endovascular aneurysm repair or open surgery. Case Reports: Two men aged 83 and 81 years were referred with a jux

  7. Upward-migrating methane induced seismic chimney formation in the Nordland Group, Southern Viking Graben

    Science.gov (United States)

    Kempka, Thomas; Unger, Victoria; Kühn, Michael

    2016-04-01

    The Nordland Group in the Southern Viking Graben hosts seismic chimneys, represented by anomalies in seismic data and determined by residual methane accumulations. These seismic chimneys are generally interpreted as focused fluid flow structures, and thus pose the risk of potential fluid leakage in geological subsurface utilization. The aim of the present study was to assess two popular scientific hypotheses on seismic chimney formation in the Nordland Group. The first one assumes excess pore pressure to result from buoyancy effects caused by upward-migrating methane and the development of a gas column with a thickness of several hundred meters, whereas the second one considers the load of the Fennoscandian ice sheet to be responsible for occurrence of hydraulic fracturing. In this context, we applied coupled hydromechanical simulations to determine the mechanism inducing the formation of these potential leakage pathways. Our simulation results demonstrate that hydraulic fracturing in the Nordland Group already occurs before the maximum methane column heights develop below. Consequently, the load of the Fennoscandian ice sheet is not initiating seismic chimneys formation.

  8. A Cost Effective Desalination Plant Using a Solar Chimney with Recycled Aluminum Can Collector

    Directory of Open Access Journals (Sweden)

    Singuru Rajesh

    2016-01-01

    Full Text Available The main objective of the work was to use solar energy for desalination of water. A solar chimney desalination system, which includes the solar chimney, solar collector, evaporation system, and passive condenser, was designed and built. The air enters into collector and gets heated and released at the bottom of chimney. Due to draught effect dry air goes upward. The air is humidified by spraying salt water into the hot air stream using a mistifier at the middle of chimney. Then, the partial vapours contained in the air are condensed to give desalinated water. The performance of the integrated system including power and potable water production was estimated and the results were discussed. With a 3.4 m height setup, experimental test rig was capable of evaporating 3.77 L water daily condensing 2.3 L water. It is compact in nature as it is easy to assemble and dissemble. It can be used for purifying rain water in summer under rain water harvesting. Because of using country wood, recycled Al cans, and GI sheet in fabrication, it is lower in cost.

  9. Geochemical processes and fluxes at a methane gas chimney on the Hikurangi Margin (New Zealand)

    Science.gov (United States)

    Dale, A.; Haffert, L.; Hütten, E.; Crutchley, G.; Greinert, J.; de Haas, H.; de Stigter, H.; Bialas, J.

    2012-04-01

    The initial results presented in this study focus on the pore water geochemistry of Takahe methane seep located at 1050 m water depth on the Hikurangi Margin. The main objectives are to characterize and quantify the geochemical processes occurring in the upper meters of sediment. Parasound images of the study site showed a well-defined seismic blanking zone of around 230 m in diameter that is likely generated by trapped methane gas. At the northern edge of this seismic gas chimney bubble release has been observed by using hydroacoustic methods (singlebeam and multibeam echosounders). At the seafloor the more northern part of the chimney area showed white Beggiatoa bacterial mats and in places dark sediment patches due to geochemically reduced environments. No other "seep specific" fauna as tube worms or clams as well as no massive chemoherm carbonate where found in the area. This points towards a rather young seepage history. Geochemical data measured in 8 gravity cores across the gas chimney support this notion and gas hydrate layers several cm thick were observed in several cores. Sulphate and total alkalinity concentrations varied little from seawater values in the upper 50 to 100 cm towards the southerly end of the seismic gas chimney area; a feature attributed to irrigation by escaping methane gas bubbles. At these stations, the pore fluids were highly enriched in biogenic methane. However, the dissolved methane was mostly consumed anaerobically by sulphate, resulting in steep gradients of sulphate, methane, total alkalinity and hydrogen sulphide. Geochemical gradients at reference site immediately outside the chimney area were essentially vertical, indicating very little upwards transport and dissolution of methane. The geochemical data are applied to a numerical reaction-transport model to quantify the total upward flux of methane at each station and, ultimately, for the entire gas chimney. Temperature measurements of thermistor probes attached to the barrel

  10. Origin of a native sulfur chimney in the Kueishantao hydrothermal field, offshore northeast Taiwan

    Institute of Scientific and Technical Information of China (English)

    ZENG; ZhiGang; LIU; ChangHua; CHEN; ChenTung; A; YIN; XueBo; CHEN; DaiGeng; WANG; XiaoYuan; WANG; XiaoMei; ZHANG; GuoLiang

    2007-01-01

    Analyses of rare earth and trace element concentrations of native sulfur samples from the Kueishantao hydrothermal field were performed at the Seafloor Hydrothermal Activity Laboratory of the Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences.Using an Elan DRC II ICP-MS,and combining the sulfur isotopic compositions of native sulfur samples,we studied the sources and formation of a native sulfur chimney.The results show,when comparing them with native sulfur from crater lakes and other volcanic areas,that the native sulfur content of this chimney is very high (99.96%),the rare earth element (REE) and trace element constituents of the chimney are very low (ΣREE<21×10-9),and the chondrite-normalized REE patterns of the native sulfur samples are similar to those of the Kueishantao andesite,implying that the interaction of subseafloor fluid-andesite at the Kueishantao hydrothermal field was of short duration.The sulfur isotopic compositions of the native sulfur samples reveal that the sulfur of the chimney,from H2S and SO2,originated by magmatic degassing and that the REEs and trace elements are mostly from the Kueishantao andesite and partly from seawater.Combining these results with an analysis of the thermodynamics,it is clear that from the relatively low temperature (<116℃),the oxygenated and acidic environment is favorable for formation of this native sulfur chimney in the Kueishantao hydrothermal field.

  11. Experimental and numerical characterization of wind-induced pressure coefficients on nuclear buildings and chimney exhausts

    Energy Technology Data Exchange (ETDEWEB)

    Ricciardi, Laurent, E-mail: laurent.ricciardi@irsn.fr; Gélain, Thomas; Soares, Sandrine

    2015-10-15

    Highlights: • Experiments on scale models of nuclear buildings and chimney exhausts were performed. • Pressure coefficient fields on buildings are shown for various wind directions. • Evolution of pressure coefficient vs U/W ratio is given for various chimney exhausts. • RANS simulations using SST k–ω turbulence model were performed on most studied cases. • A good agreement is overall observed, with Root Mean Square Deviation lower than 0.15. - Abstract: Wind creates pressure effects on different surfaces of buildings according to their exposure to the wind, in particular at external communications. In nuclear facilities, these effects can change contamination transfers inside the building and can even lead to contamination release into the environment, especially in damaged (ventilation stopped) or accidental situations. The diversity of geometries of facilities requires the use of a validated code for predicting pressure coefficients, which characterize the wind effect on the building walls and the interaction between the wind and chimney exhaust. The first aim of a research program launched by the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN), was therefore to acquire experimental data of the mean pressure coefficients for different geometries of buildings and chimneys through wind tunnel tests and then to validate a CFD code (ANSYS CFX) from these experimental results. The simulations were performed using a steady RANS approach and a two-equation SST k–ω turbulence model. After a mesh sensitivity study for one configuration of building and chimney, a comparison was carried out between the numerical and experimental values for other studied configurations. This comparison was generally satisfactory, averaged over all measurement points, with values of Root Mean Square Deviations lower than 0.15 for most cases.

  12. Experimental and numerical characterization of wind-induced pressure coefficients on nuclear buildings and chimney exhausts

    International Nuclear Information System (INIS)

    Highlights: • Experiments on scale models of nuclear buildings and chimney exhausts were performed. • Pressure coefficient fields on buildings are shown for various wind directions. • Evolution of pressure coefficient vs U/W ratio is given for various chimney exhausts. • RANS simulations using SST k–ω turbulence model were performed on most studied cases. • A good agreement is overall observed, with Root Mean Square Deviation lower than 0.15. - Abstract: Wind creates pressure effects on different surfaces of buildings according to their exposure to the wind, in particular at external communications. In nuclear facilities, these effects can change contamination transfers inside the building and can even lead to contamination release into the environment, especially in damaged (ventilation stopped) or accidental situations. The diversity of geometries of facilities requires the use of a validated code for predicting pressure coefficients, which characterize the wind effect on the building walls and the interaction between the wind and chimney exhaust. The first aim of a research program launched by the French Institut de Radioprotection et de Sûreté Nucléaire (IRSN), was therefore to acquire experimental data of the mean pressure coefficients for different geometries of buildings and chimneys through wind tunnel tests and then to validate a CFD code (ANSYS CFX) from these experimental results. The simulations were performed using a steady RANS approach and a two-equation SST k–ω turbulence model. After a mesh sensitivity study for one configuration of building and chimney, a comparison was carried out between the numerical and experimental values for other studied configurations. This comparison was generally satisfactory, averaged over all measurement points, with values of Root Mean Square Deviations lower than 0.15 for most cases

  13. S-33 constraints on the seawater sulfate contribution in modern seafloor hydrothermal vent sulfides

    Science.gov (United States)

    Ono, Shuhei; Shanks, Wayne C.; Rouxel, O.J.; Rumble, D.

    2007-01-01

    Sulfide sulfur in mid-oceanic ridge hydrothermal vents is derived from leaching of basaltic-sulfide and seawater-derived sulfate that is reduced during high temperature water rock interaction. Conventional sulfur isotope studies, however, are inconclusive about the mass-balance between the two sources because 34S/32S ratios of vent fluid H2S and chimney sulfide minerals may reflect not only the mixing ratio but also isotope exchange between sulfate and sulfide. Here, we show that high-precision analysis of S-33 can provide a unique constraint because isotope mixing and isotope exchange result in different ??33S (?????33S-0.515 ??34S) values of up to 0.04??? even if ??34S values are identical. Detection of such small ??33S differences is technically feasible by using the SF6 dual-inlet mass-spectrometry protocol that has been improved to achieve a precision as good as 0.006??? (2??). Sulfide minerals (marcasite, pyrite, chalcopyrite, and sphalerite) and vent H2S collected from four active seafloor hydrothermal vent sites, East Pacific Rise (EPR) 9-10??N, 13??N, and 21??S and Mid-Atlantic Ridge (MAR) 37??N yield ??33S values ranging from -0.002 to 0.033 and ??34S from -0.5??? to 5.3???. The combined ??34S and ??33S systematics reveal that 73 to 89% of vent sulfides are derived from leaching from basaltic sulfide and only 11 to 27% from seawater-derived sulfate. Pyrite from EPR 13??N and marcasite from MAR 37??N are in isotope disequilibrium not only in ??34S but also in ??33S with respect to associated sphalerite and chalcopyrite, suggesting non-equilibrium sulfur isotope exchange between seawater sulfate and sulfide during pyrite precipitation. Seafloor hydrothermal vent sulfides are characterized by low ??33S values compared with biogenic sulfides, suggesting little or no contribution of sulfide from microbial sulfate reduction into hydrothermal sulfides at sediment-free mid-oceanic ridge systems. We conclude that 33S is an effective new tracer for interplay among

  14. Precipitation and growth of barite within hydrothermal vent deposits from the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

    Jamieson, John William; Hannington, Mark D.; Tivey, Margaret K.; Hansteen, Thor; Williamson, Nicole M.-B.; Stewart, Margaret; Fietzke, Jan; Butterfield, David; Frische, Matthias; Allen, Leigh; Cousens, Brian; Langer, Julia

    2016-01-01

    Hydrothermal vent deposits form on the seafloor as a result of cooling and mixing of hot hydrothermal fluids with cold seawater. Amongst the major sulfide and sulfate minerals that are preserved at vent sites, barite (BaSO4) is unique because it requires the direct mixing of Ba-rich hydrothermal fluid with sulfate-rich seawater in order for precipitation to occur. Because of its extremely low solubility, barite crystals preserve geochemical fingerprints associated with conditions of formation. Here, we present data from petrographic and geochemical analyses of hydrothermal barite from the Endeavour Segment of the Juan de Fuca Ridge, northeast Pacific Ocean, in order to determine the physical and chemical conditions under which barite precipitates within seafloor hydrothermal vent systems. Petrographic analyses of 22 barite-rich samples show a range of barite crystal morphologies: dendritic and acicular barite forms near the exterior vent walls, whereas larger bladed and tabular crystals occur within the interior of chimneys. A two component mixing model based on Sr concentrations and 87Sr/86Sr of both seawater and hydrothermal fluid, combined with 87Sr/86Sr data from whole rock and laser-ablation ICP-MS analyses of barite crystals indicate that barite precipitates from mixtures containing as low as 17% and as high as 88% hydrothermal fluid component, relative to seawater. Geochemical modelling of the relationship between aqueous species concentrations and degree of fluid mixing indicates that Ba2+ availability is the dominant control on mineral saturation. Observations combined with model results support that dendritic barite forms from fluids of less than 40% hydrothermal component and with a saturation index greater than ∼0.6, whereas more euhedral crystals form at lower levels of supersaturation associated with greater contributions of hydrothermal fluid. Fluid inclusions within barite indicate formation temperatures of between ∼120 °C and 240 °C during

  15. Development of assemblages associated with alvinellid colonies on the walls of high-temperature vents at the East Pacific Rise

    Science.gov (United States)

    Pradillon, F.; Zbinden, M.; Le Bris, N.; Hourdez, S.; Barnay, A.-S.; Gaill, F.

    2009-09-01

    Several species of the polychaete family Alvinellidae may be considered as 'ecosystem engineer' because, by building their tubes, they modify the architecture of the hydrothermal fluid-seawater interface on the walls of vent chimneys. This affects the thermal and chemical gradients, and creates a mosaic of micro-niches, which could enable colonization by a variety of less-tolerant species. On high temperature vents of the Juan de Fuca Ridge, Alvinellid-dominated communities colonizing first mineral surfaces are followed by a succession of communities with different species composition. On the East Pacific Rise (EPR), tubes of Alvinella spp, may seal the mineral surface on which they grow and decrease fluid seepage, or tubes may become encrusted in mineral precipitations. An alvinellid colony may therefore persist for only a restricted time period at a given place. Here we investigated the development of alvinellid colonies on the EPR vent sites in order to detect whether a succession of new species less tolerant would follow colonization by Alvinella spp. or if different assemblages are forming depending on local conditions. Using a specially designed device called TRAC (titanium ring for alvinellid colonization), we described the evolution of newly formed colonies. Fifteen experiments were conducted on several chimneys of the 9°N and 13°N vent fields of the EPR, over durations ranging from 5 days up to 5 months. Through video analysis, different types of colonies were identified, characterized by increasing thickness of the Alvinella coverage, decreasing fluid flow bathing the colony, and decreasing surface temperatures. We showed that the assemblage formed by minerals, tubes, and organisms is produced at a very high rate. While animals may colonize the new surface in less than a week, and tubes are also quickly produced ( Alvinella species may grow their tube up to 1 cm day -1 during the early stages of colonization), mineral precipitation progressively

  16. First hydrothermal active vent discovered on the Galapagos Microplate

    Science.gov (United States)

    Tao, C.; Li, H.; Wu, G.; Su, X.; Zhang, G.; Chinese DY115-21 Leg 3 Scientific Party

    2011-12-01

    The Galapagos Microplate (GM) lies on the western Gaplapagos Spreading Center (GSC), representing one of the classic Ridge-Ridge-Ridge (R-R-R) plate boundaries of the Nazca, Cocos, and Pacific plates. The presence of the 'black smoke' and hydrothermal vent community were firstly confirmed on the GSC. Lots of hydrothermal fields were discovered on the center and eastern GSC, while the western GSC has not been well investigated. During 17th Oct. to 9th Nov. 2009, the 3rd leg of Chinese DY115-21 cruise with R/V Dayangyihao has been launched along 2°N-5°S near equatorial East Pacific Rise (EPR). Two new hydrothermal fields were confirmed. One is named 'Precious Stone Mountain', which is the first hydrothermal field on the GM. The other is found at 101.47°W, 0.84°S EPR. The 'Precious Stone Mountain' hydrothermal field (at 101.49°W, 1.22°N) is located at an off-axial seamount on the southern GM boundary, with a depth from 1,450 to 1,700m. Hydrothermal fluids emitting from the fissures and hydrothermal fauna were captured by deep-tow video. Few mineral clasts of pyrite and chalcopyrite were separated from one sediment sample, but no sulfide chimney was found yet. Hydrothermal fauna such as alive mussels, crabs, shrimps, tubeworms, giant clams, as well as rock samples were collected by TV-Grab. The study of the seafloor classification with Simrad EM120 multi-beam echosounder has been conducted on the 'Precious Stone Mountain' hydrothermal field. The result indicates that seafloor materials around the hydrothermal field can be characterized into three types, such as the fresh lava, hydrothermal sediment, and altered rock.

  17. Genomic reconstruction of an uncultured hydrothermal vent gammaproteobacterial methanotroph (family Methylothermaceae indicates multiple adaptations to oxygen limitation

    Directory of Open Access Journals (Sweden)

    Connor Tobias Skennerton

    2015-12-01

    Full Text Available Hydrothermal vents are an important contributor to marine biogeochemistry, producing large volumes of reduced fluids, gasses, and metals and housing unique, productive microbial and animal communities fueled by chemosynthesis. Methane is a common constituent of hydrothermal vent fluid and is frequently consumed at vent sites by methanotrophic bacteria that serve to control escape of this greenhouse gas into the atmosphere. Despite their ecological and geochemical importance, little is known about the ecophysiology of uncultured hydrothermal vent-associated methanotrophic bacteria. Using metagenomic binning techniques, we recovered and analyzed a near-complete genome from a novel gammaproteobacterial methanotroph (B42 associated with a white smoker chimney in the Southern Lau basin. B42 was the dominant methanotroph in the community, at ~80x coverage, with only four others detected in the metagenome, all on low coverage contigs (7x - 12x. Phylogenetic placement of B42 showed it is a member of the Methylothermaceae, a family currently represented by only one sequenced genome. Metabolic inferences based on the presence of known pathways in the genome showed that B42 possesses a branched respiratory chain with A- and B-family heme copper oxidases, cytochrome bd oxidase and a partial denitrification pathway. These genes could allow B42 to respire over a wide range of oxygen concentrations within the highly dynamic vent environment. Phylogenies of the denitrification genes revealed they are the result of separate horizontal gene transfer from other proteobacteria and suggest that denitrification is a selective advantage in conditions where extremely low oxygen concentrations require all oxygen to be used for methane activation.

  18. Characteristics of the cultivable bacteria from sediments associated with two deep-sea hydrothermal vents in Okinawa Trough.

    Science.gov (United States)

    Sun, Qing-lei; Wang, Ming-qing; Sun, Li

    2015-12-01

    In this study, different culture-dependent methods were used to examine the cultivable heterotrophic bacteria in the sediments associated with two deep-sea hydrothermal vents (named HV1 and HV2) located at Iheya Ridge and Iheya North in Okinawa Trough. The two vents differed in morphology, with HV1 exhibiting diffuse flows while HV2 being a black smoker with a chimney-like structure. A total of 213 isolates were identified by near full-length 16S rRNA gene sequence analysis. Of these isolates, 128 were from HV1 and 85 were from HV2. The bacterial community structures were, in large parts, similar between HV1 and HV2. Nevertheless, differences between HV1 and HV2 were observed in one phylum, one class, 4 orders, 10 families, and 20 genera. Bioactivity analysis revealed that 25 isolates belonging to 9 different genera exhibited extracellular protease activities, 21 isolates from 11 genera exhibited extracellular lipase activities, and 13 isolates of 8 genera displayed antimicrobial activities. This is the first observation of a large population of bacteria with extracellular bioactivities existing in deep-sea hydrothermal vents. Taken together, the results of this study provide new insights into the characteristics of the cultivable heterotrophic bacteria in deep-sea hydrothermal ecosystems.

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

    Science.gov (United States)

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

    2014-07-01

    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

  20. Explosive Volcanic Eruptions from Linear Vents on Earth, Venus and Mars: Comparisons with Circular Vent Eruptions

    Science.gov (United States)

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

    2010-01-01

    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.

  1. Iron-sulfide-bearing chimneys as potential catalytic energy traps at life's emergence.

    Science.gov (United States)

    Mielke, Randall E; Robinson, Kirtland J; White, Lauren M; McGlynn, Shawn E; McEachern, Kavan; Bhartia, Rohit; Kanik, Isik; Russell, Michael J

    2011-12-01

    The concept that life emerged where alkaline hydrogen-bearing submarine hot springs exhaled into the most ancient acidulous ocean was used as a working hypothesis to investigate the nature of precipitate membranes. Alkaline solutions at 25-70°C and pH between 8 and 12, bearing HS(-)±silicate, were injected slowly into visi-jars containing ferrous chloride to partially simulate the early ocean on this or any other wet and icy, geologically active rocky world. Dependent on pH and sulfide content, fine tubular chimneys and geodal bubbles were generated with semipermeable walls 4-100 μm thick that comprised radial platelets of nanometric mackinawite [FeS]±ferrous hydroxide [∼Fe(OH)(2)], accompanied by silica and, at the higher temperature, greigite [Fe(3)S(4)]. Within the chimney walls, these platelets define a myriad of micropores. The interior walls of the chimneys host iron sulfide framboids, while, in cases where the alkaline solution has a pH>11 or relatively low sulfide content, their exteriors exhibit radial flanges with a spacing of ∼4 μm that comprise microdendrites of ferrous hydroxide. We speculate that this pattern results from outward and inward radial flow through the chimney walls. The outer Fe(OH)(2) flanges perhaps precipitate where the highly alkaline flow meets the ambient ferrous iron-bearing fluid, while the intervening troughs signal where the acidulous iron-bearing solutions could gain access to the sulfidic and alkaline interior of the chimneys, thereby leading to the precipitation of the framboids. Addition of soluble pentameric peptides enhances membrane durability and accentuates the crenulations on the chimney exteriors. These dynamic patterns may have implications for acid-base catalysis and the natural proton motive force acting through the matrix of the porous inorganic membrane. Thus, within such membranes, steep redox and pH gradients would bear across the nanometric platelets and separate the two counter-flowing solutions

  2. Near-bottom water column anomalies associated with active hydrothermal venting at Aeolian arc volcanoes, Tyrrhenian Sea, Italy

    Science.gov (United States)

    Walker, S. L.; Carey, S.; Bell, K. L.; Baker, E. T.; Faure, K.; Rosi, M.; Marani, M.; Nomikou, P.

    2012-12-01

    Hydrothermal deposits such as metalliferous sediments, Fe-Mn crusts, and massive sulfides are common on the submarine volcanoes of the Aeolian arc (Tyrrhenian Sea, Italy), but the extent and style of active hydrothermal venting is less well known. A systematic water column survey in 2007 found helium isotope ratios indicative of active venting at 6 of the 9 submarine volcanoes surveyed plus the Marsili back-arc spreading center (Lupton et al., 2011). Other plume indicators, such as turbidity and temperature anomalies were weak or not detected. In September 2011, we conducted five ROV Hercules dives at Eolo, Enarete, and Palinuro volcanoes during an E/V Nautilus expedition. Additionally, two dives explored the Casoni seamount on the southern flank of Stromboli where a dredge returned apparently warm lava in 2002 (Gamberi, 2006). Four PMEL MAPRs, with temperature, optical backscatter (particles), and oxidation-reduction potential (ORP) sensors, were arrayed along the lowermost 50 m of the Hercules/Argus cable during the dives to assess the relationship between seafloor observations and water column anomalies. Active venting was observed at each of the volcanoes visited. Particle anomalies were weak or absent, consistent with the 2007 CTD surveys, but ORP anomalies were common. Venting at Eolo volcano was characterized by small, localized patches of yellow-orange bacteria; living tubeworms were observed at one location. ORP anomalies (-1 to -22 mv) were measured at several locations, primarily along the walls of the crescent-shaped collapse area (or possible caldera) east of the Eolo summit. At Enarete volcano, we found venting fluids with temperatures up to 5°C above ambient as well as small, fragile iron-oxide chimneys. The most intense ORP anomaly (-140 mv) occurred at a depth of about 495 m on the southeast side of the volcano, with smaller anomalies (-10 to -20 mv) more common as the ROV moved upslope to the summit. At Palinuro volcano, multiple dives located

  3. Solar chimney: A sustainable approach for ventilation and building space conditioning

    Directory of Open Access Journals (Sweden)

    Lal, S.,

    2013-03-01

    Full Text Available The residential and commercial buildings demand increase with rapidly growing population. It leads to the vertical growth of the buildings and needs proper ventilation and day-lighting. The natural air ventilation system is not significantly works in conventional structure, so fans and air conditioners are mandatory to meet the proper ventilation and space conditioning. Globally building sector consumed largest energy and utmost consumed in heating, ventilation and space conditioning. This load can be reduced by application of solar chimney and integrated approaches in buildings for heating, ventilation and space conditioning. It is a sustainable approach for these applications in buildings. The authors are reviewed the concept, various method of evaluation, modelings and performance of solar chimney variables, applications and integrated approaches.

  4. Barometric pressure transient testing applications at the Nevada Test Site. Nuclear chimney analysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, J.M.

    1985-12-01

    Investigations of barometric pressure testing of NTS nuclear chimneys were reviewed. This review includes the models used in the interpretation, methods of analysis, and results. Analytic and semi-analytic models were presented and applied to both historical data and new data taken for this current project. An interpretation technique based on non-linear least squares methods was used to analyze this data in terms of historic and more recent chimney models. Finally, a detailed discussion of radioactive gas transport due to surface barometric pressure fluctuations was presented. This mechanism of transport, referred to as ''barometric pumping,'' is presented in terms of conditions likely to be encountered at the NTS. The report concludes with a discussion of the current understanding of gas flow properties in the alluvial and volcanic areas of the NTS, and suggestions for future efforts directed toward increasing this understanding are presented.

  5. Scientific and Cost Effective Monitoring: The Case of an Aerial Insectivore, the Chimney Swift

    Directory of Open Access Journals (Sweden)

    Sébastien Rioux

    2010-12-01

    Full Text Available The increased pace of species listing worldwide, coupled with the scarcity of conservation funding, promote the use of targeted monitoring. We applied the recommendations of Nichols and Williams (Trends in Ecology and Evolution 2006 24:668-673 to optimize the Québec Chimney Swift Monitoring Program, an ongoing volunteer-based monitoring initiative launched in 1998. Past objectives of the program were to fill knowledge gaps about occupancy patterns at roosts sites, determine spatial and temporal distribution of Chimney Swifts (Chaetura pelagica across the province, locate active nest sites, and monitor temporal fluctuations of the population. By applying an adaptive management framework, we modified the current monitoring scheme into a more focused initiative testing newly developed hypotheses about the state of the system. This new approach yielded significant scientific gains as well as annual savings of 19.6%. It may prove pertinent to current and future swift monitoring initiatives and to other aerial insectivore species.

  6. Barometric pressure transient testing applications at the Nevada Test Site. Nuclear chimney analysis. Final report

    International Nuclear Information System (INIS)

    Investigations of barometric pressure testing of NTS nuclear chimneys were reviewed. This review includes the models used in the interpretation, methods of analysis, and results. Analytic and semi-analytic models were presented and applied to both historical data and new data taken for this current project. An interpretation technique based on non-linear least squares methods was used to analyze this data in terms of historic and more recent chimney models. Finally, a detailed discussion of radioactive gas transport due to surface barometric pressure fluctuations was presented. This mechanism of transport, referred to as ''barometric pumping,'' is presented in terms of conditions likely to be encountered at the NTS. The report concludes with a discussion of the current understanding of gas flow properties in the alluvial and volcanic areas of the NTS, and suggestions for future efforts directed toward increasing this understanding are presented

  7. Review of containment vent filter technology

    International Nuclear Information System (INIS)

    The technology applied for the design and construction of containment vent filters is compiled and reviewed. The national positions leading to the selection of venting or method of filtration are extracted from position papers. Several areas of further information needs are identified

  8. Energy and Carbon Flow: Comparing ultramafic- and basalt-hosted vents

    Science.gov (United States)

    Perner, M.; Bach, W.; Seifert, R.; Strauss, H.; Laroche, J.

    2010-12-01

    -hosted vents or that elevated sulfide consumption rates and biomass syntheses are significantly elevated in emissions from basalt-hosted over those from ultramafic-hosted vents. Yet, PCR-amplification from environmental samples demonstrated that the richness of uptake hydrogenases is significantly higher in the tested ultramafic-hosted (n = 4) than in the basalt-hosted (n = 3) vents. The sequence-based screening of metagenomic libraries constructed from basalt-hosted sites resulted in finding only 1 recognizable sqr-gene, but no genes encoding uptake hydrogenases or key enzymes of the CBB or rTCA cycles. Pyrosequencing of a diffuse fluid and a vent chimney (both basalt-hosted) has currently not lead to a great diversity of genes encoding enzymes associated with sulfur oxidizing mechanisms, but have displayed some genes encoding enzymes required for the maturation of uptake hydrogenases. Geochemical constraints appear to effect metabolic diversity and activity differently. [1] Amend, J., et al. (2010) AbSciCon. Texas, USA: p. 5134 [2] McCollom, T.M. (2007) Astrobiol. 7(6): p. 933-950

  9. Mapping the Piccard Hydrothermal Field - The World's Deepest Known Vent Area

    Science.gov (United States)

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

    2012-12-01

    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

  10. Scientific and Cost Effective Monitoring: The Case of an Aerial Insectivore, the Chimney Swift

    OpenAIRE

    Sébastien Rioux; Savard, Jean-Pierre L.; François Shaffer

    2010-01-01

    The increased pace of species listing worldwide, coupled with the scarcity of conservation funding, promote the use of targeted monitoring. We applied the recommendations of Nichols and Williams (Trends in Ecology and Evolution 2006 24:668-673) to optimize the Québec Chimney Swift Monitoring Program, an ongoing volunteer-based monitoring initiative launched in 1998. Past objectives of the program were to fill knowledge gaps about occupancy patterns at roosts sites, determine spatial and tempo...

  11. Basement Kind Effects on Air Temperature of a Solar Chimney in Baghdad - Iraq Weather

    Directory of Open Access Journals (Sweden)

    Miqdam Tariq Chaichan

    2011-01-01

    Full Text Available A solar updraft tower power plant (solar tower is a solar thermal power plant that utilizes a combination of solar air collector and central updraft tube to generate an induced convective flow which drives pressure staged turbines to generate electricity. This paper presents practical results of a prototype of a solar chimney with thermal mass, where the glass surface is replaced by transparence plastic cover. The study focused on chimney's basements kind effect on collected air temperatures. Three basements were used: concrete, black concrete and black pebbles basements. The study was conducted in Baghdad from August to November 2009. The results show that the best chimney efficiency attained was 49.7% for pebbles base. The highest collected air temperature reached was 49ºC when using the black pebbles basement also.also, the maximum basement temperature measured was 59ºC for black pebbles. High increaments in collected air temperatures were achieved in comparison with the ambient air temperatures for the three basement kinds. The highest temperature difference reached was 22ºC with the pebble ground.

  12. A parametric study on the feasibility of solar chimney power plants in North Cyprus conditions

    International Nuclear Information System (INIS)

    Highlights: • A parametric for solar chimney power plants (SCPPs) feasibility approach is proposed. • We found the annual electricity production of a 30 MW SCPP to be 94.5 GW h. • We compare this production with the same capacity fossil fuel thermal power plant. • We assess the effect of varying some parameters on economic viability of the SCPP. • Capital expenditure plays a critical role in assessing SCPP economic feasibility. - Abstract: The present work investigates the feasibility of installing a solar chimney power plant (SCPP) under North Cyprus (NC) conditions. The method utilized for the simulations of electricity production was compared and verified by the experimental recordings of the prototype in Manzanares, Spain, before carrying out performance predictions for different plant sizes, collector diameters and chimney heights. The annual electricity production of a 30 MW hypothetical SCPP system is estimated to be 94.5 GW h, which can cater for annual electricity needs of over 22,128 residences without any CO2, NOx and SOx emissions. For an installation cost of €145 million, it was estimated that the savings-to-investment ratio (SIR) would be 1.14, indicating a marginal economic feasibility. It is important to find ways of reducing the installation cost in order to strengthen the economic viability of the system. Considering that, at present, fuel oil no. 6 is being used in NC to produce electricity; the SCPP would cause avoidance of 24,840 tonnes of CO2 delivered into the atmosphere annually, if it replaced an equivalently-sized conventional power unit. To identify the most feasible cost option for the installation of the SCPP, a parametric cost analysis is carried out by varying the parameters such as; capital investment costs, carbon dioxide emission trading system price, chimney height, collector diameter and SCPP plant capacity. In all cases, the effect of these parameters on the economic feasibility indicators, such as SIR, net present

  13. 30 CFR 77.304 - Explosion release vents.

    Science.gov (United States)

    2010-07-01

    ... 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:...

  14. 40 CFR 264.1032 - Standards: Process vents.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Process vents. 264.1032... Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner or operator of a facility with process vents associated with distillation, fractionation,...

  15. 46 CFR 153.353 - High velocity vents.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located... velocity vent has been approved by Commandant (CG-522)....

  16. 40 CFR 265.1032 - Standards: Process vents.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Process vents. 265.1032... DISPOSAL FACILITIES Air Emission Standards for Process Vents § 265.1032 Standards: Process vents. (a) The owner or operator of a fa-cil-ity with process vents associated with distillation, fractionation,...

  17. 14 CFR 125.159 - Vent and drain lines.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Vent and drain lines. 125.159 Section 125... Requirements § 125.159 Vent and drain lines. All vent and drain lines, and their fittings, that are located in... Administrator finds that the rupture or breakage of any vent or drain line may result in a fire hazard....

  18. 46 CFR 153.362 - Venting system drain.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Venting system drain. 153.362 Section 153.362 Shipping... Systems § 153.362 Venting system drain. Unless a cargo vent system at every point is level or slopes back... system must have a drain valve at each low point (trap) in the vent line....

  19. Efficient Vent Unloading of Air Compressors

    Science.gov (United States)

    Muhonen, Alvin J.

    1987-01-01

    Method for unloading one-and two-stage reciprocating air compressors increases energy efficiency and inhibits deterioration of components. In new unloader configuration, compressor vented to atmosphere on downstream side. Method implemented expeditiously as modification of existing systems.

  20. Tellurium-bearing minerals in zoned sulfide chimneys from Cu-Zn massive sulfide deposits of the Urals, Russia

    Science.gov (United States)

    Maslennikov, V. V.; Maslennikova, S. P.; Large, R. R.; Danyushevsky, L. V.; Herrington, R. J.; Stanley, C. J.

    2013-02-01

    Tellurium-bearing minerals are generally rare in chimney material from mafic and bimodal felsic volcanic hosted massive sulfide (VMS) deposits, but are abundant in chimneys of the Urals VMS deposits located within Silurian and Devonian bimodal mafic sequences. High physicochemical gradients during chimney growth result in a wide range of telluride and sulfoarsenide assemblages including a variety of Cu-Ag-Te-S and Ag-Pb-Bi-Te solid solution series and tellurium sulfosalts. A change in chimney types from Fe-Cu to Cu-Zn-Fe to Zn-Cu is accompanied by gradual replacement of abundant Fe-, Co, Bi-, and Pb- tellurides by Hg, Ag, Au-Ag telluride and galena-fahlore with native gold assemblages. Decreasing amounts of pyrite, both colloform and pseudomorphic after pyrrhotite, isocubanite ISS and chalcopyrite in the chimneys is coupled with increasing amounts of sphalerite, quatz, barite or talc contents. This trend represents a transition from low- to high sulphidation conditions, and it is observed across a range of the Urals deposits from bimodal mafic- to bimodal felsic-hosted types: Yaman-Kasy → Molodezhnoye → Uzelga → Valentorskoye → Oktyabrskoye → Alexandrinskoye → Tash-Tau → Jusa.

  1. Safe venting of ''red oil'' runaway reactions

    International Nuclear Information System (INIS)

    Calorimetry testing of Tri-n-butyl phosphate (TBP) saturated with strong nitric acid was performed to determine the relationship between vent size and pressure buildup in the event of a runaway reaction. These experiments show that runaway can occur in an open system, but that even when runaway is induced in the TBP/HN03 system, dangerous pressure buildup will be prevented with practical vent size

  2. Zero-gravity venting of three refrigerants

    Science.gov (United States)

    Labus, T. L.; Aydelott, J. C.; Amling, G. E.

    1974-01-01

    An experimental investigation of venting cylindrical containers partially filled with initially saturated liquids under zero-gravity conditions was conducted in the NASA Lewis Research Center 5-second zero-gravity facility. The effect of interfacial mass transfer on the ullage pressure response during venting was analytically determined, based on a conduction analysis applied to an infinitely planer (flat) liquid-vapor interface. This pressure response was compared with both the experimental results and an adiabatic decompression computation.

  3. Vent Your Spleen, Live Longer

    Institute of Scientific and Technical Information of China (English)

    Randy; Dotinga; 石屏

    2004-01-01

    本文的标题是否能译成:发怒者长寿。此标题揭示了一项研究的结论:those who failed to vent their spleens(排泄怒气)were twice as likely to die(不排泄怒气者的死亡的可能性是善于排泄怒气者的两倍)文章有许多精彩表达,不可不咀嚼一番。如:with the greatest tendency to keep negative emotions bottled up-those who"sit and stew"中的bottle up和"sit and stew"(其含义相当于汉语的"闭门思过"),文中最精彩的要算连用四个定语从句的句子: …the husband yelling at the mother who yells at the kid who kicks the dogwho bites the cat who claws the mouse remains a classical American coping strat-egy(策略)

  4. The vent microbiome: patterns and drivers

    Science.gov (United States)

    Pachiadaki, M.

    2015-12-01

    Microbial processes within deep-sea hydrothermal vents affect the global biogeochemical cycles. Still, there are significant gaps in our understanding of the microbiology and the biogeochemistry of deep-sea hydrothermal systems. Vents differ in temperature, host rock composition and fluid chemistry; factors that are hypothesized to shape the distribution of the microbial communities, their metabolic capabilities and their activities. Using large-scale single cell genomics, we obtained insights into the genomic content of several linkages of a diffuse flow vent. The genomes show high metabolic versatility. Sulfur oxidation appears to be predominant but there is the potential of using a variety of e- donors and acceptors to obtain energy. To further assess the ecological importance of the vent auto- and heterotrophs, the global biogeography of the analyzed lineages will be investigated by fragment recruitment of metagenomes produced from the same site as well as other hydrothermal systems. Metatranscriptomic and metaproteomic data will be integrated to examine the expression of the predominant metabolic pathways and thus the main energy sources driving chemoautotrophic production. The comparative analysis of the key players and associated pathways among various vent sites that differ in physicochemical characteristics is anticipated to decipher the patterns and drivers of the global dispersion and the local diversification of the vent microbiome.

  5. 40 CFR Table 35 to Subpart G of... - Control Requirements for Items of Equipment That Meet the Criteria of § 63.149 of Subpart G

    Science.gov (United States)

    2010-07-01

    ... Air Pollutants From the Synthetic Organic Chemical Manufacturing Industry for Process Vents, Storage... organic hazardous air pollutants vapors to other process equipment or a fuel gas system, or a closed vent... Equipment That Meet the Criteria of § 63.149 of Subpart G 35 Table 35 to Subpart G of Part 63 Protection...

  6. Improvement of the Vertical Dispersion of Pollutants Resulting From Chimneys by Thermosiphon Effect

    Directory of Open Access Journals (Sweden)

    A. O.M. Mahmoud

    2006-01-01

    Full Text Available The dispersion of pollutants, resulting from industrial chimneys, in the surrounding atmosphere made the interest in realizing emitting conditions appears. It also encourages the vertical dispersion of these pollutants. At a given wind velocity, the height of this dispersion is essentially a function of the thermal power and the flow rate at the chimney exit. To improve these qualities, we propose a system that could be integrated to the industrial chimney exit. An open-ended vertical cylinder of larger diameter essentially constitutes this system. In order to determine the characteristics of the resulting flow, we simulated the problem in the laboratory while studying the evolution of a free thermal plume generated by a disk heated uniformly by the Joule effect at a constant temperature. The thermal plume expands in a quiet environment of isotherm temperature. To study the thermosiphon effect, we surrounded the plume source by a vertical cylinder opened at the extremities. Thermal radiation emitted by the hot disk heats the cylinder wall. The pressure drop due to the acceleration of the flow at the cylinder inlet causes the appearance of thermosiphon effect around the thermal plume. The analysis of the average fields of velocity and temperature shows that the thermosiphon effect entails a good homogenization of the flow at the system exit. Furthermore, the comparison of the results obtained at the exit of the two studied systems shows a relative increase of the flow rate and the thermal power absorbed by the air of the order of 50% under the thermosiphon effect. This result is expressed by a gain in the plume rise of the order of 40%.

  7. Design and simulation of a geothermal–solar combined chimney power plant

    International Nuclear Information System (INIS)

    Highlights: • A geothermal–solar chimney power plant (GSCPP) is designed and analyzed. • Three different models, viz. full solar model, full geothermal model and geothermal–solar mode are compared. • Power generation under GSM is larger than the sum of FSM and FGM. • GSCPP can effectively solve the continuous operation problem of the SCPP. - Abstract: The solar chimney power plant (SCPP) is dominated by the solar radiation, and therefore its discontinuous operation is an unavoidable problem. In this paper, low temperature geothermal water is introduced into the SCPP for overcoming this problem. Based on a developed transient model, theoretical analyses are carried out to investigate the performance of the geothermal–solar chimney power plant (GSCPP) with main dimensions the same as the Manzanares prototype in Spain. Three operation models, viz. the full solar model, the full geothermal model and the geothermal–solar combined model are compared in typical summer and winter days and throughout the year. It is found that the GSCPP can attractively run in the GSM to deliver power continuously. Due to the ambient-dependant geothermal water outlet temperature, introducing the geothermal water makes greater contribution in winter days than in summer days, in the night than in the daytime. Power generation under GSM is larger than the sum of FSM and FGM. GSM is not the simple superposition of FSM and FGM, but makes better utilization of solar and geothermal energy. In addition, introducing high temperature and mass flow rate geothermal water can doubled and redoubled improve the GSCPP’s power capacity

  8. Preliminary Phenomena Identification and Ranking Tables (PIRT) for SBWR start-up stability

    International Nuclear Information System (INIS)

    Phenomena Identification and Ranking Tables (PIRT) have been developed for start-up transient for SBWP. The information used for PIRT came from RAMONA-4B and TRACG analyses of the transient and from related small scale tests. The transient was divided into four distinct phases, namely, Subcooled Core Heat-up, Subcooled Chimney, Saturated Chimney and Power Ascension. The assessment criterion selected was Minimum Critical Power Ratio. The SBWR system was divided into ten components. A total of 33 distinct phenomena among the components were identified. The Phase I has 28 ranked phenomena with 17 low, 6 medium and 5 high ranking. The Phase II has 39 ranked phenomena with 18 low, 13 median and 8 high ranking. The Phase III has 47 ranked phenomena with 22 low, 10 medium and 15 high ranking. The Phase IV has 46 ranked phenomena with 16 low, 12 medium and 18 high ranking. 12 refs., 22 figs., 21 tabs

  9. Vallitalea pronyensis sp nova, isolated from a marine alkaline hydrothermal chimney

    OpenAIRE

    Ben Aissa, F.; Postec, A.; Erauso, G.; Payri, Claude; Pelletier, Bernard; Hamdi, M.; Ollivier, Bernard; Fardeau, Marie-Laure

    2014-01-01

    A novel thermotolerant, anaerobic, Gram-stain-positive, spore-forming bacterium was isolated from a hydrothermal chimney in Prony Bay, New Caledonia. This strain, designated FatNl3(T), grew at 15-55 degrees C (optimum 30 degrees C) and at pH 5.8-8.9 (optimum 7.7). It was slightly halophilic, requiring at least 0.5% NaCl for growth (optimum 2.5-3.0 %), and was able to grow at up to 6% NaCl. Sulfate, thiosulfate, elemental sulfur, sulfite, nitrate and nitrite were not used as terminal electron ...

  10. Early Results of Chimney Technique for Type B Aortic Dissections Extending to the Aortic Arch

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chen [Affiliated Hospital of Nantong University, Department of General Surgery (China); Tang, Hanfei; Qiao, Tong; Liu, Changjian; Zhou, Min, E-mail: 813477618@qq.com [The Affiliated Hospital of Nanjing University Medical School, Department of Vascular Surgery, Nanjing Drum Tower Hospital (China)

    2016-01-15

    ObjectiveTo summarize our early experience gained from the chimney technique for type B aortic dissection (TBAD) extending to the aortic arch and to evaluate the aortic remodeling in the follow-up period.MethodsFrom September 2011 to July 2014, 27 consecutive TBAD patients without adequate proximal landing zones were retrograde analyzed. Chimney stent-grafts were deployed parallel to the main endografts to reserve flow to branch vessels while extending the landing zones. In the follow-up period, aortic remodeling was observed with computed tomography angiography.ResultsThe technical success rate was 100 %, and endografts were deployed in zone 0 (n = 3, 11.1 %), zone 1 (n = 18, 66.7 %), and zone 2 (n = 6, 22.2 %). Immediately, proximal endoleaks were detected in 5 patients (18.5 %). During a mean follow-up period of 17.6 months, computed tomography angiography showed all the aortic stent-grafts and chimney grafts to be patent. Favorable remodeling was observed at the level of maximum descending aorta and left subclavian artery with expansion of true lumen (from 18.4 ± 4.8 to 25 ± 0.86 mm, p < 0.001 and 27.1 ± 0.62 to 28.5 ± 0.37 mm, p < 0.001) and depressurization of false lumen (from 23.7 ± 2.7 to 8.7 ± 3.8 mm, p < 0.001, from 5.3 ± 1.2 to 2.1 ± 2.1 mm, p < 0.001). While at the level of maximum abdominal aorta, suboptimal remodeling of the total aorta (from 24.1 ± 0.4 to 23.6 ± 1.5 mm, p = 0.06) and true lumen (from 13.8 ± 0.6 to 14.5 ± 0.4 mm, p = 0.08) was observed.ConclusionBased on our limited experience, the chimney technique with thoracic endovascular repair is demonstrated to be promising for TBAD extending to the arch with favorable aortic remodeling.

  11. Authigenic carbonate crusts and chimneys along the North Anatolian Fault in the Sea of Marmara, Turkey

    Science.gov (United States)

    Yıldız, Güliz; Namık Çaǧatay, M.

    2016-04-01

    The Sea of Marmara is located on the North Anatolian Fault (NAF) fault zone that is a major continental transform plate boundary. It has ca. 1250 m-deep Tekirdag, Central and Cinarcik basins that are separated by two NE-SW trending Central and Western Highs. Extensive cold seeps occur along the active fault segments of the NAF in the deep basins and highs, which are associated with authigenic carbonate crusts, carbonate chimneys and mounds, black sulphidic sediments, and local gas hydrates and oil seepage. The cold seep sites were observed and sampled during the Nautile submersible and Victor 6000 Remotely Operated Vehicle (ROV) dives carried out during MARNAUT and MARSITE cruises in 2007 and 2014, respectively. Here, we report the mineralogical and stable isotopic composition of the authigenic carbonates and discuss their environmental conditions and mechanisms of formation. The carbonate crusts range up to 5 cm in thickness and the chimneys and mounds are up to 2 m high. Some chimneys are active emitting fresh to brackish water at ambient bottom water temperatures (˜ 14° C). The carbonate crusts occur as a pavements, and are commonly covered with black sulphidic sediments and bacterial mats that accommodate a rich chemosynthetic community of bivalves, sea urchins and marine annelid worms (Polychaeta). The authigenic carbonates commonly consist mainly of aragonite, but in a few instances contain subequal amounts of aragonite and calcite. High Mg-calcite is usually a minor to trace component, except in one sample in which it is present as a cement of mudstone. In the active methane emission zones, the sulphate/methane boundary occurs at or close to the seafloor, whereas elsewhere in the Sea of Marmara, the same boundary is located at 2-5 m below the seafloor. This, together with very light stable carbon isotope values (δ13C=-29.8 to - 46.3 ‰ V-PDB), indicates that the anaerobic oxidation of high methane flux emitted from the active faults is the major process

  12. Simulation of solar chimney power plant with an external heat source

    International Nuclear Information System (INIS)

    Solar chimney power plant is a sustainable source of power production. The key parameter to increase the system power output is to increase its size but the plant cannot operate during night hours. This study deals with simulation work to validate results of pilot plant at Manzanares and include the effects of waste heat from a gas turbine power plant in the system. The effects show continuous night operation, a 38.8 percent increase in power at 1000 W/m2 global solar irradiation at daytime and 1.14 percent increase in overall efficiency.

  13. Retrieval columns of SO2 in industrial chimneys using DOAS passive in traverse

    Science.gov (United States)

    Galicia Mejía, Rubén; de la Rosa Vázquez, José Manuel; Sosa Iglesias, Gustavo

    2011-10-01

    The optical Differential Optical Absorption Spectroscopy (DOAS) is a technique to measure pollutant emissions like SO2, from point sources and total fluxes in the atmosphere. Passive DOAS systems use sunlight like source. Measurements with such systems can be made in situ and in real time. The goal of this work is to report the implementation of hardware and software of a portable system to evaluate the pollutants emitted in the atmosphere by industrial chimneys. We show SO2 measurements obtained around PEMEX refinerys in Tula Hidalgo that enables the identification of their pollution degree with the knowledge of speed wind.

  14. Endovascular Aortic Aneurysm Repair with Chimney and Snorkel Grafts: Indications, Techniques and Results

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Rakesh P., E-mail: rpatel9@nhs.net [Northwick Park Hospital, Department of Vascular Radiology (United Kingdom); Katsargyris, Athanasios, E-mail: kthanassos@yahoo.com; Verhoeven, Eric L. G., E-mail: Eric.Verhoeven@klinikum-nuernberg.de [Klinikum Nuernberg, Department of Vascular and Endovascular Surgery (Germany); Adam, Donald J., E-mail: donald.adam@tiscali.co.uk [Heartlands Hospital, Department of Vascular Surgery (United Kingdom); Hardman, John A., E-mail: johnhardman@doctors.org.uk [Royal United Hospital Bath, Department of Vascular Radiology (United Kingdom)

    2013-12-15

    The chimney technique in endovascular aortic aneurysm repair (Ch-EVAR) involves placement of a stent or stent-graft parallel to the main aortic stent-graft to extend the proximal or distal sealing zone while maintaining side branch patency. Ch-EVAR can facilitate endovascular repair of juxtarenal and aortic arch pathology using available standard aortic stent-grafts, therefore, eliminating the manufacturing delays required for customised fenestrated and branched stent-grafts. Several case series have demonstrated the feasibility of Ch-EVAR both in acute and elective cases with good early results. This review discusses indications, technique, and the current available clinical data on Ch-EVAR.

  15. ANALYSIS OF VENTING OF A RESIN SLURRY

    Energy Technology Data Exchange (ETDEWEB)

    Laurinat, J.; Hensel, S.

    2012-03-27

    A resin slurry venting analysis was conducted to address safety issues associated with overpressurization of ion exchange columns used in the Purex process at the Savannah River Site (SRS). If flow to these columns were inadvertently interrupted, an exothermic runaway reaction could occur between the ion exchange resin and the nitric acid used in the feed stream. The nitric acid-resin reaction generates significant quantities of noncondensable gases, which would pressurize the column. To prevent the column from rupturing during such events, rupture disks are installed on the column vent lines. The venting analysis models accelerating rate calorimeter (ARC) tests and data from tests that were performed in a vented test vessel with a rupture disk. The tests showed that the pressure inside the test vessel continued to increase after the rupture disk opened, though at a slower rate than prior to the rupture. Calculated maximum discharge rates for the resin venting tests exceeded the measured rates of gas generation, so the vent size was sufficient to relieve the pressure in the test vessel if the vent flow rate was constant. The increase in the vessel pressure is modeled as a transient phenomenon associated with expansion of the resin slurry/gas mixture upon rupture of the disk. It is postulated that the maximum pressure at the end of this expansion is limited by energy minimization to approximately 1.5 times the rupture disk burst pressure. The magnitude of this pressure increase is consistent with the measured pressure transients. The results of this analysis demonstrate the need to allow for a margin between the design pressure and the rupture disk burst pressure in similar applications.

  16. Thermal Analyses of Combined Utilization Process of Seawater by Solar Chimney

    Institute of Scientific and Technical Information of China (English)

    WANG Yiping; FANG Zhenlei; ZHU Li

    2009-01-01

    It is promising to simultaneously develop multiple products through the combined utilization of sea-water by solar chimney technology. A small scale experimental system was set up. The collector temperature, the seawater temperature, and the temperature and humidity of the airflow under the collector were measured. Thermal network analysis of the system was carried out. The results show that the airflow is nearly saturated at the entrance of the chimney, and the mean dry-bulb and wet-bulb temperatures of the airflow have increased by 8.4℃ and 9.6℃ respectively. The radiation heat transfer between the collector and the sky is the biggest heat loss in the system, which is up to 29.1% on average of the solar energy. However, the water evaporation heat is about 23.6% on average of the solar energy. To reduce the heat loss and enhance the water evaporation, it is necessary to reduce the emissivity and thermal conductivity of the collector and increase the evaporation areas.

  17. A novel large filamentous deltaproteobacterium on hydrothermally inactive sulfide chimneys of the Southern Mariana Trough

    Science.gov (United States)

    Kato, Shingo; Yamagishi, Akihiko

    2016-04-01

    Unusual large filamentous bacteria (LFB) have been found on the deep seafloor environments. They play a significant role in geochemical cycling in the dark environments. However, our knowledge of the spatial distribution and phylogenetic diversity of the LFB on the deep seafloor are still limited due to the inaccessibility to these environments. Here, we report the discovery of a novel LFB on a hydrothermally inactive sulfide chimney in a deep-sea hydrothermal field of the Southern Mariana Trough. Light and electron microscopic observation showed that the width and total length of the LFB were >8 μm and >100 μm, respectively, of which morphology was similar to that of other known LFB such as "cable bacteria" of the Desulfobulbaceae. Analyses of a 16S rRNA gene clone library and fluorescence in situ hybridization revealed that this LFB belongs to the Desulfobulbaceae. The 16S rRNA gene of the LFB showed 94% similarity to those of the reported cable bacteria and cultured deltaproteobacterial species, suggesting that the LFB is a novel cable bacterium of the Desulfobulbaceae. The novel LFB potentially play a role in sulfur cycling on sulfide chimneys at the hydrothermally ceasing or even ceased deep-sea hydrothermal fields.

  18. Fluid composition of the sediment-influenced Loki's Castle vent field at the ultra-slow spreading Arctic Mid-Ocean Ridge

    Science.gov (United States)

    Baumberger, Tamara; Früh-Green, Gretchen L.; Thorseth, Ingunn H.; Lilley, Marvin D.; Hamelin, Cédric; Bernasconi, Stefano M.; Okland, Ingeborg E.; Pedersen, Rolf B.

    2016-08-01

    The hydrothermal vent field Loki's Castle is located in the Mohns-Knipovich bend (73°N) of the ultraslow spreading Arctic Mid-Ocean Ridge (AMOR) close to the Bear Island sediment fan. The hydrothermal field is venting up to 320° C hot black smoker fluids near the summit of an axial volcanic ridge. Even though the active chimneys have grown on a basaltic ridge, geochemical fluid data show a strong sedimentary influence into the hydrothermal circulation at Loki's Castle. Compelling evidence for a sediment input is given by high alkalinity, high concentrations of NH4+, H2, CH4, C2+ hydrocarbons as well as low Mn and Fe contents. The low δ13C values of CO2 and CH4 and the thermogenic isotopic pattern of the C2+ hydrocarbons in the high-temperature vent fluids clearly point to thermal degradation of sedimentary organic matter and illustrate diminution of the natural carbon sequestration in sediments by hydrothermal circulation. Thus, carbon-release to the hydrosphere in Arctic regions is especially relevant in areas where the active Arctic Mid-Ocean Ridge system is in contact with the organic matter rich detrital sediment fans.

  19. Vents et nuages la physique du ciel

    CERN Document Server

    2013-01-01

    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 !

  20. Computational fluid dynamics for modeling the turbulent natural convection in a double air-channel solar chimney system

    Science.gov (United States)

    Zavala-Guillén, I.; Xamán, J.; Álvarez, G.; Arce, J.; Hernández-Pérez, I.; Gijón-Rivera, M.

    2016-03-01

    This study reports the modeling of the turbulent natural convection in a double air-channel solar chimney (SC-DC) and its comparison with a single air-channel solar chimney (SC-C). Prediction of the mass flow and the thermal behavior of the SC-DC were obtained under three different climates of Mexico during one summer day. The climates correspond to: tropical savannah (Mérida), arid desert (Hermosillo) and temperate with warm summer (Mexico City). A code based on the Finite Volume Method was developed and a k-ω turbulence model has been used to model air turbulence in the solar chimney (SC). The code was validated against experimental data. The results indicate that during the day the SC-DC extracts about 50% more mass flow than the SC-C. When the SC-DC is located in Mérida, Hermosillo and Mexico City, the air-changes extracted along the day were 60, 63 and 52, respectively. The air temperature at the outlet of the chimney increased up to 33%, 38% and 61% with respect to the temperature it has at the inlet for Mérida, Hermosillo and Mexico City, respectively.

  1. Thermodynamic analysis of a low-temperature waste heat recovery system based on the concept of solar chimney

    International Nuclear Information System (INIS)

    Highlights: • A low grade waste heat recovery system based on the concept of solar chimney is proposed. • The effects of three key factors on the system performance are examined. • Thermodynamics analysis is to find a better way to utilize low grade heat source efficiently. - Abstract: The utilization of low-temperature waste heat draws more and more attention due to serious energy crisis nowadays. This paper proposes a low-temperature waste heat recovery system based on the concept of solar chimney. In the system, low-temperature waste heat is used to heat air to produce an air updraft in the chimney tower. The air updraft propels a turbine fixed at the base of the chimney tower to convert waste heat into electricity. The mathematical model of the system is established based on first law and second law of thermodynamics. Hot water is selected as the representative of low-temperature waste heat sources for researching. The heat source temperature, ambient air temperature and area of heat transfer are examined to evaluate their effects on the system performance such as velocity of updraft, mass flow rate of air, power output, conversion efficiency, and exergy efficiency. The velocity of air demonstrates a better stability than the mass flow rate of air and the pressure difference when temperature of heat source, ambient air temperature or area of heat transfer changes

  2. Prototype implementation and experimental analysis of water heating using recovered waste heat of chimneys

    Directory of Open Access Journals (Sweden)

    Mahmoud Khaled

    2015-03-01

    Full Text Available This work discusses a waste heat recovery system (WHRS applied to chimneys for heating water in residential buildings. A prototype illustrating the suggested system is implemented and tested. Different waste heat scenarios by varying the quantity of burned firewood (heat input are experimented. The temperature at different parts of the WHRS and the gas flow rates of the exhaust pipes are measured. Measurements showed that the temperature of 95 L tank of water can be increased by 68 °C within one hour. Obtained results show that the convection and radiation exchanges at the bottom surface of the tank have a considerable impact on the total heat transfer rate of the water (as high as 70%.

  3. Efficiency enhancement of wood stove integrated with catalytic combustor and modified chimney

    Directory of Open Access Journals (Sweden)

    G. Murali

    2014-12-01

    Full Text Available Domestic wood combustion produces smoke that is harmful to human health and increases fine particle level in the atmosphere. Some necessary changes in the design are essential in the domestic wood stove in order to improve the performance and scale down the emission. In this work, an improved wood stove integrated with the catalytic combustor and modified chimney that uses wood as fuel has been experimentally evaluated. Water boiling test, cooking test and emission test have been conducted to evaluate the performance of the stove. It was observed that emission has been considerably controlled because of the incorporation of catalytic combustor. The heat losses through the walls of stove decresed by providing ceramic insulation. The thermal efficiency value of an improved wood stove obtained was 41.18% and this is 31.52% higher than traditional stove. The improved wood stove results better performance than a traditional wood stove.

  4. 46 CFR 56.50-85 - Tank-vent piping.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Tank-vent piping. 56.50-85 Section 56.50-85 Shipping... APPURTENANCES Design Requirements Pertaining to Specific Systems § 56.50-85 Tank-vent piping. (a) This section applies to vents for all independent, fixed, non-pressure tanks or containers or for spaces in...

  5. 33 CFR 183.520 - Fuel tank vent systems.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Fuel tank vent systems. 183.520...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.520 Fuel tank vent systems. (a) Each fuel tank must have a vent system that prevents pressure in the tank from exceeding...

  6. 40 CFR 63.1321 - Batch process vents provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents provisions. 63.1321... Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1321 Batch process vents provisions. (a) Batch process vents. Except as specified in paragraphs (b) through (d) of this...

  7. 14 CFR 27.975 - Fuel tank vents.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Fuel tank vents. 27.975 Section 27.975... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.975 Fuel tank vents. (a) Each fuel tank... flight conditions. Each vent must minimize the probability of stoppage by dirt or ice. (b) The...

  8. 40 CFR 63.690 - Standards: Process vents.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Standards: Process vents. 63.690....690 Standards: Process vents. (a) The provisions of this section apply to the control of air emissions from process vents for which § 63.683(c)(1)(i) of this subpart references the use of this section...

  9. 14 CFR 121.261 - Vent and drain lines.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Vent and drain lines. 121.261 Section 121... drain lines. All vent and drain lines and their fittings, that are located in a designated fire zone... the rupture or breakage of any vent or drain line may result in a fire hazard....

  10. 14 CFR 34.11 - Standard for fuel venting emissions.

    Science.gov (United States)

    2010-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...

  11. 40 CFR 63.983 - Closed vent systems.

    Science.gov (United States)

    2010-07-01

    ... inspections for visible, audible, or olfactory indications of leaks. (ii) If the closed vent system is... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Closed vent systems. 63.983 Section 63... Emission Standards for Closed Vent Systems, Control Devices, Recovery Devices and Routing to a Fuel...

  12. Origin of pockmarks and chimney structures on the flanks of the Storegga Slide, offshore Norway

    Science.gov (United States)

    Paull, C.K.; Ussler, W., III; Holbrook, W.S.; Hill, T.M.; Keaten, R.; Mienert, J.; Haflidason, H.; Johnson, J.E.; Winters, W.J.; Lorenson, T.D.

    2008-01-01

    Seafloor pockmarks and subsurface chimney structures are common on the Norwegian continental margin north of the Storegga Slide scar. Such features are generally inferred to be associated with fluid expulsion, and imply overpressures in the subsurface. Six long gravity and piston cores taken from the interior of three pockmarks were compared with four other cores taken from the same area but outside the pockmarks, in order to elucidate the origins and stratigraphy of these features and their possible association with the Storegga Slide event. Sulfate gradients in cores from within pockmarks are less steep than those in cores from outside the pockmarks, which indicates that the flux of methane to the seafloor is presently smaller within the pockmarks than in the adjacent undisturbed sediments. This suggests that these subsurface chimneys are not fluid flow conduits lined with gas hydrate. Methane-derived authigenic carbonates and Bathymodiolus shells obtained from a pockmark at >6.3 m below the seafloor indicate that methane was previously available to support a chemosynthetic community within the pockmark. AMS 14C measurements of planktonic Foraminifera overlying and interlayered with the shell-bearing sediment indicate that methane was present on the seafloor within the pockmark prior to 14 ka 14C years B.P., i.e., well before the last major Storegga Slide event (7.2 ka 14C years B.P., or 8.2 ka calendar years B.P.). These observations provide evidence that overpressured fluids existed within the continental margin sediments off Norway during the last major advance of Pleistocene glaciation. ?? Springer-Verlag 2007.

  13. 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...

  14. Preoperational test report, vent building ventilation system

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, F.T.

    1997-11-04

    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.

  15. Filtered atmospheric venting of LWR containments

    International Nuclear Information System (INIS)

    The FILTRA project is a cooperative Swedish programme which started in February 1980. It is aimed at investigating the possibility of reducing the risk for a large release of radioactivity, assuming a severe reactor accident. The project has been focused on filtered venting of the reactor containment. The first stage of the project has dealt with two types of severe accident sequences, namely core meltdown as a result of the complete loss of water supplies to the reactor pressure vessel and insufficient cooling of the reactor containment. Some important conclusion are the following. The applicability of computer models used to describe various phenomena in the accident sequence must be scrutinized. The details of the design of the containment are important and must be taken into consideration in a more accurate manner than in previous analyses. A pressure relief area of less than 1 m2 appears to be adequate. The following principles should guide the technical design of filtered venting systems, namely reduction of the risk for the release of those radioactive substances which could cause long term land contamination, provision for a passive function of the vent filter system during the first 24 hours and achievement of filtering capabilities which make leakages in severe accidents comparable to the leakages of radioactive substances in less severe accidents, which do not necessarily actuate the pressure relief system. Nothing indicates that a system for filtered venting of a BWR containment would have a significant negative effect on the safety within the framework of the design basis. Efforts should be directed towards designing a filtered venting system for a BWR such as Barsebaeck. (authors)

  16. Determining real temperature of steel chimney surface using thermograpy method. (Polish Title: Wyznaczenie rzeczywistej temperatury powierzchni kominów stalowych metodą termograficzną)

    Science.gov (United States)

    Wróbel, Anna; Wróbel, Andrzej

    2013-12-01

    Assembly and technical evaluation of a steel chimney both require determining shape of its axis. Because permissible deflection of the top of a steel chimney shaft relative to the base according to the PN-B-06200 norm is: 30 mm when height 50 m, geodetic measurements should be performed with high accuracy. Additionally, the measurements should be performed when deflection of the chimney is not influenced by sun and wind. Deflection measured in a sunny weather is influenced by elastic deflection caused by uneven temperature distribution in the chimney shaft. In practice, the measurements should be done before the sunrise or on a cloudy day. However, during chimney assembly it is often not possible to choose conditions of measurement. For steel chimneys of cylindrical shape without thermal insulation inside, the direction of elastic deflection is not very different from the direction of sun's rays, and its value can be calculated from dimensions of the chimney and temperature differences on its circumference. The problem discussed in this article is measuring the real temperature of the outer surface of a chimney in a possibly fast and accurate way. Thermography allows acquiring the surface temperature distribution quickly (in a few minutes). The accuracy of the measured values is influenced by: emissivity coefficient of the chimney surface, air temperature and humidity and background temperature. The biggest problem is determining background temperature if the surroundings consist of a few objects with different temperatures. The equivalent background temperature was determined from thermo graphic and contact temperature measurements of a specially prepared sample. The sample was produced from the same material as the steel chimney, covered with the same paint and the measurements were performed near the chimney, so the surroundings were similar to the surroundings of the chimney. Conducted experiment shows that on a sunny day the background temperature cannot be

  17. Previously unsuspected dietary habits of hydrothermal vent fauna: the bactivorous shrimp Rimicaris hybisae can be carnivorous or even cannibalistic

    Science.gov (United States)

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

    2014-05-01

    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

  18. Endovascular Aneurysm Repair Using a Reverse Chimney Technique in a Patient With Marfan Syndrome and Contained Ruptured Chronic Type B Dissection

    International Nuclear Information System (INIS)

    We report endovascular thoracic and abdominal aneurysm repair (EVAR) with reverse chimney technique in a patient with contained ruptured type B dissection. EVAR seems feasible as a bailout option in Marfan patients with acute life-threatening disease.

  19. 40 CFR Table 1 of Subpart Bbbbbbb... - Emission Reduction and PM Concentration Requirements

    Science.gov (United States)

    2010-07-01

    ... Concentration Requirements 1 Table 1 of Subpart BBBBBBB of Part 63 Protection of Environment ENVIRONMENTAL... Reduction and PM Concentration Requirements For each * * * You must * * * Using * * * 1. Process Vent Stream... percent reduction efficiency of 95 percent (98 percent for new sources), or b. An outlet concentration...

  20. Provisions for containment venting in Germany

    Energy Technology Data Exchange (ETDEWEB)

    Wilhelm, J.G.

    1997-08-01

    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.

  1. Experiments of chimney flows for the validation of the behaviour of passive autocatalytic recombiners; Experimente zur Validierung eines Kaminmodells fuer die Simulation des Betriebsverhaltens eines Wasserstoffrekombinators

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Berno [RWTH Aachen Univ. (Germany). Lehrstuhl fuer Reaktorsicherheit und -technik (LRST)

    2013-10-15

    For the validation of the computational code REKO-DIREKT simulating the operational behaviour of passive autocatalytic recombiners in severe accidents, experiments on chimney flows were performed in cooperation between RWTH Aachen and Forschungszentrum Juelich. This compact describes the experimental setup and shows the correlation between the H{sub 2} concentration, the catalyst temperature and the inlet velocity at various recombiner chimney heights. (orig.)

  2. Soil-Structure Interaction Analysis of Tall Reinforced Concrete Chimney with Piled Raft and Annular Raft under Along-Wind Load

    Directory of Open Access Journals (Sweden)

    B. R. Jayalekshmi

    2013-01-01

    Full Text Available A three-dimensional (3D soil-structure interaction (SSI analysis of 300 m high reinforced concrete chimneys having piled annular raft and annular raft foundations subjected to along-wind load is carried out in the present study. To understand the significance of SSI, four types of soils were considered based on their flexibility. The effect of stiffness of the raft was evaluated using three different ratios of external diameter to thickness of the annular raft. The along-wind load was computed according to IS:4998 (Part 1-1992. The integrated chimney-foundation-soil system was analysed by commercial finite element (FE software ANSYS, based on direct method of SSI assuming linear elastic behaviour. FE analyses were carried out for two cases of SSI (I chimney with annular raft foundation and (II chimney with piled raft foundation. The responses in chimney such as tip deflection, bending moments, and base moment and responses in raft such as bending moments and settlements were evaluated for both cases and compared to that obtained from the conventional method of analysis. It is found that the responses in chimney and raft depend on the flexibility of the underlying soil and thickness of the raft.

  3. Ecology of deep-sea hydrothermal vent communities: A review

    Science.gov (United States)

    Lutz, Richard A.; Kennish, Michael J.

    1993-08-01

    Studies of the many active and inactive hydrothermal vents found during the past 15 years have radically altered views of biological and geological processes in the deep sea. The biological communities occupying the vast and relatively stable soft bottom habitats of the deep sea are characterized by low population densities, high species diversity, and low biomass. In contrast, those inhabiting the generally unstable conditions of hydrothermal vent environments exhibit high densities and biomass, low species diversity, rapid growth rates, and high metabolic rates. Biological processes, such as rates of metabolism and growth, in vent organisms are comparable to those observed in organisms from shallow-water ecosystems. An abundant energy source is provided by chemosynthetic bacteria that constitute the primary producers sustaining the lush communities at the hydrothermal sites. Fluxes in vent flow and fluid chemistry cause changes in growth rates, reproduction, mortality, and/or colonization of vent fauna, leading to temporal and spatial variation of the vent communities. Vent populations that cannot adapt to modified flow rates are adversely affected, as is evidenced by high mortality or lower rates of colonization, growth, or reproduction. Substantial changes in biota have been witnessed at several vents, and successional cycles have been proposed for the Galapagos vent fields. Dramatic temporal and spatial variations in vent community structure may also relate to variations in larval dispersal and chance recruitment, as well as biotic interactions.

  4. The Inventory Of High Objects Applying Laser Scanning, Focus On The Cataloguing A Reinforced Concrete Industrial Chimney

    Science.gov (United States)

    Gawałkiewicz, Rafał

    2015-12-01

    There are many surveying methods to measure the inclination of a chimney with the use of classical protractor instruments (Theo 010A/B, T2 Wild), electronic theodolites (TC2002 Wild-Leica), electronic total stations, including mirrorless ones, allowing to define indirectly the course of the construction's axis on the selected observation levels. The methods are the following: indentations, direct projection, double-edged method, polar method with the option of mirrorless measurement. At the moment a very practical and quick measurement technology, significantly eliminating the influence of human errors on the observation results, is laser scanning. The article presents the results of the scanning of 120-metres high reinforced concrete industrial chimney of the Cement Plant "Ożarów", with the application of modern scanning total station VX Spatial Station by Trimble, as an alternative to the methods applied so far. The advantage of scanning is the possibility to obtain a point cloud, which, apart from the information on the course of the chimney axis in the space, provides detail information on the real shape and deformations of the coating of the object's core.

  5. Dioxin emissions from coal combustion in domestic stove: Formation in the chimney and coal chlorine content influence

    Directory of Open Access Journals (Sweden)

    Paradiz Bostjan

    2015-01-01

    Full Text Available Combustion experiments conducted in domestic stove burning hard coal demonstrated a predominant influence of the coal chlorine content on the PCDD/F emissions, together with a pronounced effect of the flue gas temperature. PCDD/F concentrations of over 100 ng TEQ/m3, three orders of magnitude higher than in a modern waste incinerator, were measured in the flue gases of a domestic stove when combusting high chlorine coal (0.31 %. The PCDD/F concentrations in the flue gases dropped below 0,5 ng TEQ/m3, when low chlorine coal (0.07 % was used. When low chlorine coal was impregnated with NaCl to obtain 0.38 % chlorine content, the emission of the PCDD/Fs increased by two orders of magnitude. Pronounced nonlinearity of the PCDD/F concentrations related to chlorine content in the coal was observed. The combustion of the high chlorine coal yielded PCDD/F concentrations in flue gases one order of magnitude lower in a fan cooled chimney when compared to an insulated one, thus indicating formation in the chimney. The influence of flue gas temperature on the PCDD/F emissions was less pronounced when burning low chlorine coal. The predominant pathway of the PCDD/F emissions is via flue gases, 99 % of the TEQ in the case of the high chlorine coal for insulated chimney.

  6. Free release waste characterisation during the decommissioning of windscale Pile 2 Chimney

    Energy Technology Data Exchange (ETDEWEB)

    Frith, A.J. [NIRAS (United Kingdom); Dickson, E.D.; Hewetson, J.A.; McCormick, K. [BNFL (United Kingdom)

    2003-07-01

    The decommissioning of windscale Pile 2 Chimney resulted in the removal of one of most historically significant and prominent features of the Sellafield site. The project was the first large scale concrete ''free release'' operation to be undertaken on the Sellafield nuclear site, producing 4500 tons of concrete of which 3000 tons was demonstrated to be ''free release''. The paper describes the radiometric techniques employed in the characterisation and segregation of the concrete into low level waste (LLW), very low level waste (VLLW) and free release categories. It examines the robust solutions that were developed to meet the technical and regulatory challenges of the project, which included the definition of free release, the selection of averaging volumes, the testing and validation of the monitoring systems employed for ton quantities of concrete and the identification and removal of small numbers of fuel particles from the free release waste stream. As a result of interest shown by other BNFL and UKAEA decommissioning projects at Sellafield, the paper finishes by discussing ways in which the system may be developed to assay other waste streams. (orig.)

  7. Clostridium tepidiprofundi sp. nov., a moderately thermophilic bacterium from a deep-sea hydrothermal vent.

    Science.gov (United States)

    Slobodkina, G B; Kolganova, T V; Tourova, T P; Kostrikina, N A; Jeanthon, C; Bonch-Osmolovskaya, E A; Slobodkin, A I

    2008-04-01

    A moderately thermophilic, anaerobic bacterium (strain SG 508T) was isolated from a hydrothermal vent chimney located at 1 degrees N on the East Pacific Rise at a depth of 2650 m. Cells of strain SG 508T were straight to slightly curved rods, 0.4-0.6 microm in diameter and 2.0-3.0 microm in length. Spore formation was observed only below pH 5.5. The temperature range for growth was 22-60 degrees C, with optimum growth at 50 degrees C. The pH range for growth was 4.0-8.5, with optimum growth at pH 6.0-6.8. Growth of strain SG 508T was observed at NaCl concentrations ranging from 1.0 to 6.0 % (w/v), with optimum growth at 2.5 % (w/v). Substrates utilized by strain SG 508T included casein, peptone, tryptone, yeast extract, beef extract, starch, maltose and glucose. The products of glucose fermentation were ethanol, acetate, H2, formate and CO2. Strain SG 508T was able to reduce elemental sulfur to hydrogen sulfide. The DNA G+C content of strain SG 508T was 30.9 mol%. 16S rRNA gene sequence analysis revealed that the isolated organism belonged to cluster I of the genus Clostridium. On the basis of its physiological properties and data from phylogenetic analyses, strain SG 508T is considered to represent a novel species of the genus Clostridium, for which the name Clostridium tepidiprofundi sp. nov. is proposed. The type strain is SG 508T (=DSM 19306T =VKM B-2459T).

  8. Development of an ecotoxicological protocol for the deep-sea fauna using the hydrothermal vent shrimp Rimicaris exoculata.

    Science.gov (United States)

    Auguste, M; Mestre, N C; Rocha, T L; Cardoso, C; Cueff-Gauchard, V; Le Bloa, S; Cambon-Bonavita, M A; Shillito, B; Zbinden, M; Ravaux, J; Bebianno, M J

    2016-06-01

    In light of deep-sea mining industry development, particularly interested in massive-sulphide deposits enriched in metals with high commercial value, efforts are increasing to better understand potential environmental impacts to local fauna. The aim of this study was to assess the natural background levels of biomarkers in the hydrothermal vent shrimp Rimicaris exoculata and their responses to copper exposure at in situ pressure (30MPa) as well as the effects of depressurization and pressurization of the high-pressure aquarium IPOCAMP. R. exoculata were collected from the chimney walls of the hydrothermal vent site TAG (Mid Atlantic Ridge) at 3630m depth during the BICOSE cruise in 2014. Tissue metal accumulation was quantified in different tissues (gills, hepatopancreas and muscle) and a battery of biomarkers was measured: metal exposure (metallothioneins), oxidative stress (catalase, superoxide dismutase, glutathione-S-transferase and glutathione peroxidase) and oxidative damage (lipid peroxidation). Data show a higher concentration of Cu in the hepatopancreas and a slight increase in the gills after incubations (for both exposed groups). Significant induction of metallothioneins was observed in the gills of shrimps exposed to 4μM of Cu compared to the control group. Moreover, activities of enzymes were detected for the in situ group, showing a background protection against metal toxicity. Results suggest that the proposed method, including a physiologically critical step of pressurizing and depressurizing the test chamber to enable the seawater exchange during exposure to contaminants, is not affecting metal accumulation and biomarkers response and may prove a useful method to assess toxicity of contaminants in deep-sea species. PMID:27101410

  9. Novel insights into methane cycling, lateral gene transfer, and the rare biosphere within carbonate chimneys of the Lost City Hydrothermal Field (Invited)

    Science.gov (United States)

    Brazelton, W. J.; Ludwig, K. A.; Schrenk, M. O.; Kelley, D. S.; Sogin, M. L.; Baross, J. A.

    2010-12-01

    The Lost City Hydrothermal Field, an ultramafic-hosted system located 15 km west of the Mid-Atlantic Ridge, has experienced at least 30,000 years of hydrothermal activity. Previous studies have shown that its carbonate chimneys form by mixing of ~90°C, pH 9-11 hydrothermal fluids and cold seawater. Flow of methane and hydrogen-rich hydrothermal fluids through the carbonate chimneys supports dense microbial biofilm communities. This presentation will describe recent studies using new techniques that have provided greater insight into the microbial ecology and biogeochemistry of Lost City chimneys. We have investigated the archaeal and bacterial communities of Lost City carbonate chimneys that vary in age between ~30 and ~1200 years, as determined by U-Th isotope systematics. Using next-generation pyrosequencing technology, we collected >200,000 sequences of the V6 region of 16S rRNA genes. This extremely deep sequencing effort enabled detection of very rare organisms as well as abundant organisms detected by previous studies. The taxonomic composition of the archaeal and bacterial communities clearly differed in chimneys of different ages, and many of the rare sequences in young chimneys were more abundant in older chimneys, indicating that members of the rare biosphere can become dominant members of the ecosystem when environmental conditions change. These results suggest that a long history of selection over many cycles of chimney growth has resulted in numerous closely related species at Lost City, each of which is pre-adapted to a particular set of re-occurring environmental conditions. In this model, the rare biosphere can be considered a repository for genes that are not currently advantageous but have been in the past and may be again in the future. Interestingly, metagenomic sequencing at Lost City has indicated the potential for frequent lateral gene transfer among organisms inhabiting the chimney biofilms. Specifically, the Lost City metagenomic dataset

  10. Hydrogen behaviour in the filtra filtered-vented containment system

    International Nuclear Information System (INIS)

    Hydrogen behaviour in gravel beds has been studied experimentally to obtain design data for vent filter systems with gravel condensers. Filtered atmospheric venting of Light Water Reactors is considered as a means of reducing the risk of extensive land contamination in connection with Class 9 accidents. The purpose of the FILTRA project is to provide the technical basis for an evaluation of the feasibility, effectiveness, and cost of some vent filter design concepts

  11. Experimental investigation of external explosion in the venting process

    Institute of Scientific and Technical Information of China (English)

    DU Zhi-min; JIN Xin-qiao; UI Dong-ming; YE Jing-fang

    2005-01-01

    Experimental investigations were conducted on the process of combustion and explosion vent in a 200 mm (diameter)×400 mm (length) vertical cylindrical vessel. When CH4-air mixture gases were used and the vent diameter was 55 mm,conditions of φ (equivalent ratio)=0.8, φ=1.0 and φ=1.3 and two ignition positions (at the cylinder center and bottom) were selected. The venting processes and the correlated factors are discussed in this paper.

  12. Morphology and dynamics of explosive vents through cohesive rock formations

    OpenAIRE

    O. Galland; G. R. Gisler; Øystein Thorden Haug

    2014-01-01

    Shallow explosive volcanic processes, such as kimberlite volcanism and phreatomagmatic and phreatic activity, produce volcanic vents exhibiting a wide variety of morphologies, including vertical pipes and V-shaped vents. In this study we report on experimental and numerical models designed to capture a range of vent morphologies in an eruptive system. Using dimensional analysis, we identified key governing dimensionless parameters, in particular the gravitational stress-to-fluid pressure rati...

  13. Pension Insurance Data Tables

    Data.gov (United States)

    Pension Benefit Guaranty Corporation — Find out about retirement trends in PBGC's data tables. The tables include statistics on the people and pensions that PBGC protects, including how many Americans...

  14. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2015.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  15. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2016.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  16. NNDSS - Table IV. Tuberculosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table IV. Tuberculosis - 2014.This Table includes total number of cases reported in the United States, by region and by states, in accordance with the...

  17. Tabled Execution in Scheme

    Energy Technology Data Exchange (ETDEWEB)

    Willcock, J J; Lumsdaine, A; Quinlan, D J

    2008-08-19

    Tabled execution is a generalization of memorization developed by the logic programming community. It not only saves results from tabled predicates, but also stores the set of currently active calls to them; tabled execution can thus provide meaningful semantics for programs that seemingly contain infinite recursions with the same arguments. In logic programming, tabled execution is used for many purposes, both for improving the efficiency of programs, and making tasks simpler and more direct to express than with normal logic programs. However, tabled execution is only infrequently applied in mainstream functional languages such as Scheme. We demonstrate an elegant implementation of tabled execution in Scheme, using a mix of continuation-passing style and mutable data. We also show the use of tabled execution in Scheme for a problem in formal language and automata theory, demonstrating that tabled execution can be a valuable tool for Scheme users.

  18. Experimental investigation on influence of smoke venting velocity and vent height on mechanical smoke exhaust efficiency.

    Science.gov (United States)

    Jie, Ji; Kaiyuan, Li; Wei, Zhong; Ran, Huo

    2010-05-15

    A set of burning experiments were conducted to investigate the influence of smoke vent height and exhausting velocity on mechanical smoke exhausting efficiency. Results have shown that the smoke exhausting process becomes more efficient due to the increased smoke vent height and the decreased exhausting velocity, which eliminate the plug-holing issue with fewer disturbances on the smoke layer interface. For each certain exhausting velocity, there is a critical value of distance between the vent and the bottom of the smoke layer. When the distance is less than the critical value, the smoke exhausting is inefficient, and the efficiency decreases sharply as the distance decreases. Contrarily, when the distance is greater than the critical value, a good efficiency can be acquired and the exhausted smoke increased relatively slowly as the distance increases. A critical Froude number, proposed by Hinkley to predict the onset of plug-holing effect in gravity venting systems, was validated in the experiments. However, the experimental results indicate that in the tests without the plug-holing, the fresh air entrained due to smoke exhausting is up to 48% of the mechanical exhausting rate. PMID:20042292

  19. Exposition-vente - French version only

    CERN Multimedia

    2004-01-01

    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 http://www.suisseniger.com hama@suisseniger.com Compte de chèques postaux : 70-395231-8

  20. Physico-chemical gradients within the hydrothermal chimney Roane define sharp boundaries for microbial community ecology

    Science.gov (United States)

    Frank, K. L.; Kelley, D. S.; Girguis, P. R.

    2011-12-01

    The unique physico-chemical gradients characteristic of hydrothermal vents provide diverse niches for prokaryotic communities. To date, our knowledge of environmental constraints on microbial colonization and metabolic activity within active sulfide structures has been limited by the lack of co-registered in situ chemistry and appropriate, taxonomic and metabolic genetic markers. Here we characterize de novo endolithic microbial colonization using a sulfide microbial incubator within the hydrothermal vent Roane during a one-year deployment, with co-registered temperature, fluid chemistry and mineralogy. Taxanomic assessment of phylogenetic diversity via 16S rDNA extracted from the outer (40-70°C) and middle (150-240°C) chambers of the incubator revealed patterns of distribution comparable to previously published observations. However, quantitative and statistical analyses of 16S rDNA sequences from two chambers revealed very distinct communities, with less than 5% of the identified operational taxonomic units common to both chambers. Analyses of metagenomic data suggest an elevated potential for motility and select biosynthetic pathways in the outer chamber community. In contrast, the middle chamber community exhibits a greater potential for quorum sensing, biofilm formation and archaeal lipid biosynthesis. Striking differences in metabolic potential were also apparent. These data suggest that the distribution, abundance and physiological capacity of these communities is strongly governed by chemical and physical variability of the environment.

  1. Table Tennis Club

    CERN Multimedia

    Table Tennis Club

    2013-01-01

    Apparently table tennis plays an important role in physics, not so much because physicists are interested in the theory of table tennis ball scattering, but probably because it provides useful breaks from their deep intellectual occupation. It seems that many of the greatest physicists took table tennis very seriously. For instance, Heisenberg could not even bear to lose a game of table tennis, Otto Frisch played a lot of table tennis, and had a table set up in his library, and Niels Bohr apparently beat everybody at table tennis. Therefore, as the CERN Table Tennis Club advertises on a poster for the next CERN Table Tennis Tournament: “if you want to be a great physicist, perhaps you should play table tennis”. Outdoor table at restaurant n° 1 For this reason, and also as part of the campaign launched by the CERN medical service “Move! & Eat better”, to encourage everyone at CERN to take regular exercise, the CERN Table Tennis Club, with the supp...

  2. Periodic Table of Students.

    Science.gov (United States)

    Johnson, Mike

    1998-01-01

    Presents an exercise in which an eighth-grade science teacher decorated the classroom with a periodic table of students. Student photographs were arranged according to similarities into vertical columns. Students were each assigned an atomic number according to their placement in the table. The table is then used to teach students about…

  3. Microbial carbon cycling in Lost City hydrothermal chimneys and other serpentinite-hosted ecosystems (Invited)

    Science.gov (United States)

    Brazelton, W. J.; Lang, S. Q.; Morrill, P. L.; Twing, K. I.; Crespo-Medina, M.; Morgan-Smith, D.; Früh-Green, G. L.; Schrenk, M. O.

    2013-12-01

    Ultramafic rocks formed in the Earth's mantle and uplifted into the crust represent an immense but poorly described reservoir of carbon. The biological availability of this rock-hosted carbon reservoir is unknown, but the set of geochemical reactions known as serpentinization can mobilize carbon from the subsurface and trigger the growth of dense microbial communities. Serpentinite-hosted ecosystems such as the chimney biofilms of the Lost City hydrothermal field can support dense populations of bacteria and archaea fueled by the copious quantities of H2 and methane (CH4) released by serpentinization (1-5). The metabolic pathways involved, however, remain unknown, and conventional interpretations of genomic and experimental data are complicated by the unusual carbon speciation in these environments. Carbon dioxide is scarce due to the highly reducing, high pH conditions. Instead, the predominant forms of carbon are CH4 and formate (5). Despite its natural abundance, however, direct evidence for CH4-derived biomass is lacking (1,4,5), and the role of formate is potentially significant but largely unexplored (1,5). To gain a more generalized perspective of carbon cycling in serpentinite-hosted ecosystems, we have recently investigated fluids and rocks collected from serpentinizing ophiolites in California, Canada, and Italy. Our results point to potentially H2-utilizing, autotrophic Betaproteobacteria thriving in shallow, oxic-anoxic transition zones and anaerobic Clostridia inhabiting anoxic, subsurface zones (1,6). The carbon sources utilized by the Clostridia are unknown, but preliminary metagenomic evidence is consistent with a fermentation-style metabolic strategy that may be conducive to an oxidant-limited, subsurface environment. Curiously, despite the abundance of H2 and CH4 in these continental springs, none of the geochemical, genomic, or experimental results obtained thus far contain any evidence for biological methanogenesis (1,6). This is in stark

  4. Application of Solar Chimney Concept to Solve Potential Safety Issues of Nuclear Power Plants

    International Nuclear Information System (INIS)

    In this paper two main events and their causes have been investigated and a potential alternative supporting system will be provided. The first event to be addressed is the Station Blackout (SBO) caused by the inherent unreliability of the Emergency Diesel Generators (EDGs) and Alternative AC (AAC) power sources. Different parameters affect The EDG unreliability; for instance, mechanical, operational, maintenance and surveillance. Those parameters will be analyzed and linked to plant safety and Core Damage Frequency (CDF). Also the AACs, the SBO diesel generators, will be studied and their operational requirements similarity with the EDGs will be discussed. The second event to be addressed is the Loss of Ultimate Heat Sink (LUHS) caused by the degradation of heat exchange effectiveness, that is, the poor heat transfer to the Ultimate Heat Sink (UHS). Different causes to such case were observed; intake lines blockages due to ice and foreign biological matters formation and oil spill near the heat sink causing the oil leakage to the heat exchangers tubes. The later cause, oil spill, has been given a special attention here due its potential effects for different nuclear power plants (NPPs) around the world; for example, Finland and the United Arab Emirates (UAE). For the Finnish case, the Finnish nuclear regulator (STUK) took already countermeasures for such scenario by introducing alternative heat sink, cooling towers, for the primary used heat sink, sea water, for one of its nuclear power plants. The abundance of the solar irradiation in the UAE region provides a perfect condition for the implementation of solar power applications. Utilizing this unique characteristic of that region may provide promising alternative and diverse options for solving potential safety related issues of their NPPs. The Solar Chimney Power Plant (SCPP) could be employed to serve as a supporting system to provide emergency power, in the case of SBO, and emergency cooling, in the case of

  5. Application of Solar Chimney Concept to Solve Potential Safety Issues of Nuclear Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Khasawneh, Khalid; PARK, Youn Won [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    In this paper two main events and their causes have been investigated and a potential alternative supporting system will be provided. The first event to be addressed is the Station Blackout (SBO) caused by the inherent unreliability of the Emergency Diesel Generators (EDGs) and Alternative AC (AAC) power sources. Different parameters affect The EDG unreliability; for instance, mechanical, operational, maintenance and surveillance. Those parameters will be analyzed and linked to plant safety and Core Damage Frequency (CDF). Also the AACs, the SBO diesel generators, will be studied and their operational requirements similarity with the EDGs will be discussed. The second event to be addressed is the Loss of Ultimate Heat Sink (LUHS) caused by the degradation of heat exchange effectiveness, that is, the poor heat transfer to the Ultimate Heat Sink (UHS). Different causes to such case were observed; intake lines blockages due to ice and foreign biological matters formation and oil spill near the heat sink causing the oil leakage to the heat exchangers tubes. The later cause, oil spill, has been given a special attention here due its potential effects for different nuclear power plants (NPPs) around the world; for example, Finland and the United Arab Emirates (UAE). For the Finnish case, the Finnish nuclear regulator (STUK) took already countermeasures for such scenario by introducing alternative heat sink, cooling towers, for the primary used heat sink, sea water, for one of its nuclear power plants. The abundance of the solar irradiation in the UAE region provides a perfect condition for the implementation of solar power applications. Utilizing this unique characteristic of that region may provide promising alternative and diverse options for solving potential safety related issues of their NPPs. The Solar Chimney Power Plant (SCPP) could be employed to serve as a supporting system to provide emergency power, in the case of SBO, and emergency cooling, in the case of

  6. Metagenome and Metatranscriptome Revealed a Highly Active Sulfur Cycle in an Oil-Immersed Hydrothermal Chimney in Guaymas Basin

    OpenAIRE

    Ying eHe; Xiaoyuan eFeng; Jing eFang; Yu eZhang; Xiang eXiao

    2015-01-01

    The hydrothermal vent system is a typical chemosynthetic ecosystem in which microorganisms play essential roles in the geobiochemical cycling. Although it has been well recognized that the inorganic sulfur compounds are abundant and actively converted through chemosynthetic pathways, the sulfur budget in a hydrothermal vent is poorly characterized due to the complexity of microbial sulfur cycling resulting from the numerous parties involved in the processes. In this study, we performed an int...

  7. Vallitalea pronyensis sp. nov., isolated from a marine alkaline hydrothermal chimney.

    Science.gov (United States)

    Ben Aissa, Fatma; Postec, Anne; Erauso, Gaël; Payri, Claude; Pelletier, Bernard; Hamdi, Moktar; Ollivier, Bernard; Fardeau, Marie-Laure

    2014-04-01

    A novel thermotolerant, anaerobic, Gram-stain-positive, spore-forming bacterium was isolated from a hydrothermal chimney in Prony Bay, New Caledonia. This strain, designated FatNI3(T), grew at 15-55 °C (optimum 30 °C) and at pH 5.8-8.9 (optimum 7.7). It was slightly halophilic, requiring at least 0.5 % NaCl for growth (optimum 2.5-3.0 %), and was able to grow at up to 6 % NaCl. Sulfate, thiosulfate, elemental sulfur, sulfite, nitrate and nitrite were not used as terminal electron acceptors. Growth of strain FatNI3(T) was inhibited in the presence of sulfite (2 mM) or nitrite (2 mM). Strain FatNI3(T) fermented cellobiose, glucose, mannose, maltose, sucrose, galactose, lactose, ribose, fructose, rhamnose, raffinose, xylose, yeast extract, peptone and biotrypticase. The main fermentation products from glucose metabolism were acetate, ethanol, H2 and CO2. The predominant cellular fatty acids were iso-C15 : 0 and anteiso-C15 : 0. The main polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, and unknown glycolipids and phospholipids. The G+C content of the genomic DNA was 36.6 mol%. On the basis of phylogenetic and physiological properties, strain FatNI3(T) ( = DSM 25904 = JCM 18391) belonging to the phylum Firmicutes, class Clostridia, order Clostridiales, is proposed as the type strain of a novel species of the genus Vallitalea, for which the name Vallitalea pronyensis sp. nov. is proposed. PMID:24408522

  8. Accumulative Landings System Code Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Code Tables Used In Landings System. These tables assign meanings to the codes that appear in the data tables. Code tables exist for species, gear, state, county,...

  9. Venting processes: Effects on the vicinity

    International Nuclear Information System (INIS)

    In the case of venting as a protective measure against explosions a dangerous pressure wave and a large flame must be expected in the neighbourhood of the vent. Moreover the recoil force which is exerted on the protected vessel can be the cause for the destruction of the plant. Therefore experiments have been made on the dependence of the pressure wave and the recoil force from well-known or easily determinable parameters. The results of the investigations allow the estimation of the maximum overpressure which must be expected at a given point outside the vessel, if the reduced explosion pressure which will be reached in the interior of the vessel is known. Beyond that it could be shown that the maximum recoil force is nearly always considerably smaller than the value given by theory. Only very rarely the theoretical value is reached. Therefore it is totally sufficient for practical purposes when the maximum recoil to be expected is calculated from the theoretical equation. (orig.)

  10. Venting processes: Effects on the vicinity

    Energy Technology Data Exchange (ETDEWEB)

    Hattwig, M.

    1980-01-01

    In the case of venting as a protective measure against explosions a dangerous pressure wave and a large flame must be expected in the neighbourhood of the vent. Moreover the recoil force which is exerted on the protected vessel can be the cause for the destruction of the plant. Therefore experiments have been made on the dependence of the pressure wave and the recoil force from well-known or easily determinable parameters. The results of the investigations allow the estimation of the maximum overpressure which must be expected at a given point outside the vessel, if the reduced explosion pressure which will be reached in the interior of the vessel is known. Beyond that it could be shown that the maximum recoil force is nearly always considerably smaller than the value given by theory. Only very rarely the theoretical value is reached. Therefore it is totally sufficient for practical purposes when the maximum recoil to be expected is calculated from the theoretical equation.

  11. Geochemical studies on the biodiversity and hydrothermal activity; mineralogy, chemistry, and age determination of hydrothermal chimney collected from Suiyo seamount, Izu-Bonin arc

    Science.gov (United States)

    Noguchi, T.; Oomori, T.; Taira, N.; Takada, J.; Urabe, T.

    2004-12-01

    Hydrothermal chimney structure has the steep environmental gradients of temperature, redox potential, pH and chemical concentration, which will provide diverse microhabitats for microbial communities (K.Takai et al. 2001, Hermie J.M. Harmsen et al. 1997). It is important for detailed understanding of the biodiversity to determine the chimney structural environment. Suiyo seamount is located 28.57° N, 140.66° E, where is suitable to compare with the Mid-ocean ridge hydrothermal field, because of few influence of terrestrial sediment. It was reported that the magma chamber below the seamount was very shallow ( ˜1 km), and high temperature hydrothermal fluid chamber was underlying just below the seafloor sealed with anhydrite and barite. Chimney samples used in this study were collected by Dive 1222-1225 of SHINKAI 2000 (JAMSTEC) in 2000. We measured the chemical composition with neutron activation analysis (NAA) and X-ray fluorescence analysis (XRF), mineral composition with X-ray diffraction analysis (XRD), and the precipitation age measurements ( ˜200 years) of these chimneys with γ -ray spectrometry (210Pb/Pb method, 228Th/228Ra method, and 210Pb/226Ra method). The mineral composition of the Suiyo seamount chimney were contained barite (BaSO4), sphalerite ((Zn,Fe)S), pyrite (FeS2), and chalcopyrite (CuFeS2) as a major mineral constituents. The chemical composition shows that gold contents in the chimney collected from Suiyo seamount were much higher (maximum 166 ppm) than other hydrothermal field. The chronological study showed that the precipitation ages of sulfide chimney samples (ranged in 37.2-79.6 years before 2002 by 210Pb/Pb method) were older than barite chimney ((ranged in 2.9-8.2 years before 2002 by 228Th/228Ra method). We will discuss about the process of chimney formation, the temporal variation of the past hydrothermal activity and the difference from other submarine hydrothermal fields (EPR, MAR, Okinawa trough, Loihi seamount).

  12. Numerical investigation on the enhancement capability of annular chimney towards natural convective heat transfer in the interior zone of scaled down FBR core catcher

    International Nuclear Information System (INIS)

    Full text of publication follows: A numerical study has been carried out to determine the influence of annular cylindrical chimney on buoyancy-induced flow in the dished end cavity of scaled down Fast Breeder Reactor. Results are presented for (i) cylindrical chimney configuration and (ii) annular chimney configuration occupying the center of the circular plate. Two dimensional laminar simulations are obtained by solving the fully elliptical governing equations of flow and energy. The fluid is Newtonian and incompressible and satisfies the Boussinesq approximation. Results for the upward facing isothermal circular plate with chimney configurations in confined enclosure are analyzed. The velocity fields and isotherms are studied extensively to assess the impact of both geometries on the flow structure, dynamics and overall heat transfer characteristics in the cavity, towards enhancement of natural convective heat transfer. The predicted results for the cylindrical chimney are compared with known experimental results. The results are of interest to post accident heat removal in fast breeder reactors (FBR). (authors)

  13. High levels of natural radioactivity in biota from deep sea hydrothermal vents

    International Nuclear Information System (INIS)

    Hydrothermal vent ecosystems are associated with areas of tectonic activities throughout the deep sea and are thus enriched in natural primitive radionuclides characterizing the magma source i.e. uranium-thorium series. However, the amount of data on radionuclide content in hydrothermal vent biota is very scarce. Here we present data from various archived biological samples collected on several hydrothermal vent site. Samples were collected by manned or unmanned submersibles on the East Pacific Rise (EPR) in 1996 and 2002 and on the Mid Atlantic Ridge (MAR) in 2001. Their concentrations in uranium and thorium isotopes were determined by isotope dilution mass spectrometry. Measurements were performed with a Sector field ICP-MS, the Axiom single collector from VG Elemental (Winsford, Cheshire, UK). 210Po was determined through alpha spectrometry. Results in Table II underline that high levels in uranium isotopes are found in polychaetes from the East Pacific Rise. The highest contents characterize their tubes plus mucus samples. On the contrary, the deep-sea amphipod sample (Orchomenella) collected outside hydrothermal vent areas exhibits the lowest values though direct comparison is difficult due to variability between species. 238U contents in coastal marine organisms are generally in the range 1 to 5 Bq kg-1 dry weight. Comparison between sites (Atlantic vs Pacific) is not obvious since different species have been sampled on MAR and EPR but the highest levels characterize the samples from EPR. Some samples demonstrate 234U/238U ratios very close to the mean value for seawater (1.1 - 1.2) but four present lower ratios (i.e. one sample of Bathymodiolus, Paralvinella, Riftia and Orchomenella). This is certainly to be linked to an uptake of particulate uranium. 210Po contents are very high in polychaetes tubes and mucus and are almost entirely supported by 210Pb. This in agreement with what has been reported by Cherry et al. (1992) for polychaetes (Alvinella and

  14. CERN Table Tennis Club

    CERN Multimedia

    CERN Table Tennis Club

    2014-01-01

    CERN Table Tennis Club Announcing CERN 60th Anniversary Table Tennis Tournament to take place at CERN, from July 1 to July 15, 2014   The CERN Table Tennis Club, reborn in 2008, is encouraging people at CERN to take more regular exercise. This is why the Club, thanks to the strong support of the CERN Staff Association, installed last season a first outdoor table on the terrace of restaurant # 1, and will install another one this season on the terrace of Restaurant # 2. Table tennis provides both physical exercise and friendly social interactions. The CERN Table Tennis club is happy to use the unique opportunity of the 60th CERN anniversary to promote table tennis at CERN, as it is a game that everybody can easily play, regardless of level. Table tennis is particularly well suited for CERN, as many great physicists play table tennis, as you might already know: “Heisenberg could not even bear to lose a game of table tennis”; “Otto Frisch played a lot of table tennis;...

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

    Science.gov (United States)

    Chown, Steven L

    2012-01-01

    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. 40 CFR 63.1254 - Standards: Process vents.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Standards: Process vents. 63.1254... Standards for Pharmaceuticals Production § 63.1254 Standards: Process vents. (a) Existing sources. For each...-based emission reduction requirement. (i) Uncontrolled HAP emissions from the sum of all process...

  17. An authoritative global database for active submarine hydrothermal vent fields

    Science.gov (United States)

    Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.; Maffei, Andrew

    2013-11-01

    The InterRidge Vents Database is available online as the authoritative reference for locations of active submarine hydrothermal vent fields. Here we describe the revision of the database to an open source content management system and conduct a meta-analysis of the global distribution of known active vent fields. The number of known active vent fields has almost doubled in the past decade (521 as of year 2009), with about half visually confirmed and others inferred active from physical and chemical clues. Although previously known mainly from mid-ocean ridges (MORs), active vent fields at MORs now comprise only half of the total known, with about a quarter each now known at volcanic arcs and back-arc spreading centers. Discoveries in arc and back-arc settings resulted in an increase in known vent fields within exclusive economic zones, consequently reducing the proportion known in high seas to one third. The increase in known vent fields reflects a number of factors, including increased national and commercial interests in seafloor hydrothermal deposits as mineral resources. The purpose of the database now extends beyond academic research and education and into marine policy and management, with at least 18% of known vent fields in areas granted or pending applications for mineral prospecting and 8% in marine protected areas.

  18. Where are the undiscovered hydrothermal vents on oceanic spreading ridges?

    Science.gov (United States)

    Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.

    2015-11-01

    In nearly four decades since the discovery of deep-sea vents, one-third of the length of global oceanic spreading ridges has been surveyed for hydrothermal activity. Active submarine vent fields are now known along the boundaries of 46 out of 52 recognized tectonic plates. Hydrothermal survey efforts over the most recent decade were sparked by national and commercial interests in the mineral resource potential of seafloor hydrothermal deposits, as well as by academic research. Here we incorporate recent data for back-arc spreading centers and ultraslow- and slow-spreading mid-ocean ridges (MORs) to revise a linear equation relating the frequency of vent fields along oceanic spreading ridges to spreading rate. We apply this equation globally to predict a total number of vent fields on spreading ridges, which suggests that ~900 vent fields remain to be discovered. Almost half of these undiscovered vent fields (comparable to the total of all vent fields discovered during 35 years of research) are likely to occur at MORs with full spreading rates less than 60 mm/yr. We then apply the equation regionally to predict where these hydrothermal vents may be discovered with respect to plate boundaries and national jurisdiction, with the majority expected to occur outside of states' exclusive economic zones. We hope that these predictions will prove useful to the community in the future, in helping to shape continuing ridge-crest exploration.

  19. Hydrogen Vent Ground Umbilical Quick Disconnect - Flight Seal Advanced Development

    Science.gov (United States)

    Girard, Doug; Jankowski, Fred; Minich, Mark C.; Yu, Weiping

    2012-01-01

    This project is a team effort between NASA Engineering (NE) and Team QNA Engineering personnel to provide support for the Umbilical Systems Development project which is funded by Advanced Exploration Systems (AES) and 21st Century Launch Complex. Specifically, this project seeks to develop a new interface between the PPBE baselined Legacy SSP LH2 Vent Arm QD probe and SLS vent seal.

  20. 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.

    2015-02-01

    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.

  1. Lipid biomarkers of deep-sea hydrothermal vent polychaetes— Alvinella pompejana, A. caudata, Paralvinella grasslei and Hesiolyra bergii

    Science.gov (United States)

    Phleger, Charles F.; Nelson, Matthew M.; Groce, Ami K.; Craig Cary, S.; Coyne, Kathryn; Gibson, John A. E.; Nichols, Peter D.

    2005-12-01

    The lipid composition was determined for 5 species of polychaete annelids collected by the Deep Submergence Vehicle ALVIN from high temperature chimneys at the 2500 m depth hydrothermal vent field of the East Pacific Rise. These are the first lipid biomarker analyses reported for these hydrothermal vent polychaetes. Lipid content was low in all samples (1.6-35.9 mg g -1 wet mass) and was dominated by polar lipid (78-90% of total lipid) with 8-19% sterol (ST), and very low storage lipid (triacylglycerol and wax ester). Total polyunsaturated fatty acids (PUFA) were moderately high (22-31% of total fatty acids (FA)) with extremely low or no docosahexaenoic acid (DHA, 22:6(n-3)). Eicosapentaenoic acid (EPA, 20:5(n-3)) levels were 5-6% in Alvinella pompejana and A. caudata and 10.3-13.7% in an errantiate polychaete (likely Hesionidae) and Hesiolyra bergii. There were greater PUFA and a greater EPA/AA (AA is arachidonic acid, 20:4(n-6)) ratio in the anterior versus the posterior half of A. pompejana, which may correlate to the strong temperature gradient reported in its tube. Total nonmethylene interrupted diunsaturated fatty acids (NMID) were 4-9% of total FA for most polychaete species and included several 20:2 and 22:2 components. The principal monounsaturated fatty acids (MUFA) included 18:1(n-7)c (14-19%), 16:1(n-7)c (2.6-10%) and 20:1(n-11)c (3-7% of total FA). These polychaete species may desaturate and elongate the bacterial-derived 18:1(n-7)c to obtain the essential FA EPA and AA. The major ST in the polychaetes is cholesterol (89-98% of total ST) with less cholesterol in the gut contents of A. pompejana. Other ST included 24-ethylcholesterol (1.5-5% of total ST) with lesser amounts of 24-methylenecholesterol, desmosterol, lathosterol, 24-methylcholesterol, 24-ethylcholesterol, and the stanols dehydrocholestanol and cholestanol. The high ST levels could play a role in thermal adaptation of membranes at the hydrothermal vent environment. Differences in the FA

  2. Endovascular Treatment of a Symptomatic Thoracoabdominal Aortic Aneurysm by Chimney and Periscope Techniques for Total Visceral and Renal Artery Revascularization

    Energy Technology Data Exchange (ETDEWEB)

    Cariati, Maurizio, E-mail: cariati.maurizio@sancarlo.mi.it [San Carlo Borromeo Hospital, Department of Diagnostic Sciences (Italy); Mingazzini, Pietro; Dallatana, Raffaello [San Carlo Borromeo Hospital, Department of Vascular Surgery (Italy); Rossi, Umberto G. [San Carlo Borromeo Hospital, Department of Diagnostic Sciences (Italy); Settembrini, Alberto [San Carlo Borromeo Hospital, Università degli Studi di Milano (Italy); Santuari, Davide [San Carlo Borromeo Hospital, Department of Vascular Surgery (Italy)

    2013-05-02

    Conventional endovascular therapy of thoracoabdominal aortic aneurysm with involving visceral and renal arteries is limited by the absence of a landing zone for the aortic endograft. Solutions have been proposed to overcome the problem of no landing zone; however, most of them are not feasible in urgent and high-risk patients. We describe a case that was successfully treated by total endovascular technique with a two-by-two chimney-and-periscope approach in a patient with acute symptomatic type IV thoracoabdominal aortic aneurysm with supra-anastomotic aneurysm formation involving the renal and visceral arteries and a pseduaneurismatic sac localized in the left ileopsoas muscle.

  3. Acetoanaerobium pronyense sp. nov., an anaerobic alkaliphilic bacterium isolated from a carbonate chimney of the Prony Hydrothermal Field (New Caledonia)

    OpenAIRE

    Bes, M. (Marta); Merrouch, M.; Joseph, Manon; Quéméneur, Marianne; Payri, Claude; Pelletier, Bernard; Ollivier, Bernard; Fardeau, Marie-Laure; Erausol, G.; A. Postec

    2015-01-01

    A novel anaerobic bacterial strain, ST07-YET, was isolated from a carbonate chimney of the Prony Hydrothermal Field (PHF) in New Caledonia. Cells were Gram-stain-positive, straight rods (0.7-0.8 x 3.0-5.0 mu m) and motile by means of lateral flagella. Strain ST07-YET was mesophilic (optimum 35 degrees C), moderately alkaliphilic and halotolerant (optimum pH 8.7 and 5 gr l(-1) NaCl). Elemental sulfur, sulfate, thiosulfate, sulfite, nitrate and nitrite were not used as terminal electron accepto...

  4. 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.

    2015-01-01

    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 th

  5. TABLE TENNIS CLUB

    CERN Document Server

    TABLE TENNIS CLUB

    2010-01-01

    2010 CERN Table Tennis Tournament The CERN Table Tennis Club organizes its traditional CERN Table Tennis Tournament, at the Meyrin club, 2 rue de livron, in Meyrin, Saturday August 21st, in the afternoon. The tournament is open to all CERN staff, users, visitors and families, including of course summer students. See below for details. In order to register, simply send an E-mail to Jean-Pierre Revol (jean-pierre.revol@cern.ch). You can also download the registration form from the Club Web page (http://www.cern.ch/tabletennis), and send it via internal mail. Photo taken on August 22, 2009 showing some of the participants in the 2nd CERN Table Tennis tournament. INFORMATION ON CERN TABLE TENNIS CLUB CERN used to have a tradition of table tennis activities at CERN. For some reason, at the beginning of the 1980’s, the CERN Table Tennis club merged with the Meyrin Table Tennis club, a member of the Association Genevoise de Tennis de Table (AGTT). Therefore, if you want to practice table tennis, you...

  6. Validation experiments of the chimney model for the operational simulation of hydrogen recombiners; Experimente zur Validierung eines Kaminmodells fuer die Simulation des Betriebsverhaltens eines Wasserstoffrekombinators

    Energy Technology Data Exchange (ETDEWEB)

    Simon, Berno [RWTH Aachen Univ. (Germany). Lehrstuhl fuer Reaktorsicherheit und -technik (LRST)

    2013-07-01

    The calculation program REKO-DIREKT allows the simulation of the operational behavior of a hydrogen recombiner during accidents with hydrogen release. The interest is focused on the interaction between the catalyst insertion and the chimney that influences the natural ventilation and thus the throughput through the recombiner significantly. For validation experiments were performed with a small-scale recombiner model in the test facility REKO-4. The results show the correlation between the hydrogen concentration at the recombiner entrance, the temperature on catalyst sheets and the entrance velocity using different chimney heights. The entrance velocity increases with the heights of the installed chimney that influences the natural ventilation significantly. The results allow the generation of a wide data base for validation of the computer code REKO-DIREKT.

  7. Deep-Sea Hydrothermal-Vent Sampler

    Science.gov (United States)

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

    2008-01-01

    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

  8. Evolutionary origins of hydrothermal vents metazoans

    Directory of Open Access Journals (Sweden)

    Samadi Sarah

    2015-01-01

    Full Text Available The discovery of the oases associated with hydrothermal vents in the deep sea, is probably the most fascinating discovery of oceanography of the last century. In this habitat, contrary to all expectations, a thriving development of unknown organisms was observed. At that time the knowledge about the deep sea organisms was very scarce and the accepted hypotheses about their evolutionary origins, their physiology or their ecology were very speculative. Almost forty years later, exploration of the deep-sea realm, but also of paleontological data together with the improvements in the phylogenetic methods, allowed the rejection of the hypothesis of an evolutionary history cut off the rest of the marine realm.

  9. Containment venting sliding pressure venting process for PWR and BWR plants

    International Nuclear Information System (INIS)

    In order to reduce the residual risk associated with hypothetical severe nuclear accidents, nuclear power plants in Germany as well as in certain other European countries have been or will be backfitted with a system for filtered containment venting. During venting system process design, particular importance is attached to the requirements regarding, for example, high aerosol loading capability, provision for decay heat removal from the scrubber unit, the aerosol spectrum to be retained and entirely passive functioning of the scrubber unit. The aerosol spectrum relevant for process design and testing varies depending on aerosol concentrations, the time at which venting is commenced and whether there is an upstream wetwell, etc. Because of this the Reactor Safety Commission in Germany has specified that SnO2 with a mass mean diameter of approximately 0.5 μm should be used as an enveloping test aerosol. To meet the above-mentioned requirements, a combined venturi scrubber system was developed which comprises a venturi section and a filter demister section and is operated in the sliding pressure mode. This scrubber system was tested using a full-scale model and has now been installed in 14 PWR and BWR plants in Germany and Finland

  10. Severe compression of a bailout self-expanding chimney stent for rescuing the miscoverage of left common carotid artery during TEVAR of a type B aortic dissection.

    Science.gov (United States)

    Wang, Lixin; Guo, Daqiao; Jiang, Junhao; Shi, Zhenyu; Fu, Weiguo; Wang, Yuqi

    2014-04-01

    A 54-year-old man who suffered from paraplegia due to type B aortic dissection was treated with a Valiant stent-graft. However, attempts to gain secure proximal sealing resulted in an inadvertent coverage of the left common carotid artery by the endograft. The blood flow in the left common carotid artery was restored by a transcarotid Smart Control stent in a chimney fashion. At 6- and 18-month follow-up, computed tomography scan showed that the chimney stent was severely compressed by the stent graft, although the patient remained neurologically asymptomatic. PMID:24309751

  11. High-resolution 3D seismic investigations of hydrate-bearing fluid-escape chimneys in the Nyegga region of the Voring Plateau, Norway

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, G.; Exley, R. [Birmingham Univ., Birmingham (United Kingdom). School of Geography, Earth and Environmental Sciences; Minshull, T.; Jose, T. [National Oceanography Centre, Southampton (United Kingdom); Nouze, H.; Ker, S. [French Research Inst. for Exploitation of the Sea (France). Dept. of Geosciences; Gailler, A. [Birmingham Univ., Birmingham (United Kingdom). School of Geography, Earth and Environmental Sciences]|[French Research Inst. for Exploitation of the Sea (France). Dept. of Geosciences; Plaza, A. [Tromso Univ., Tromso (Norway). Inst. for Geology]|[French Research Inst. for Exploitation of the Sea (France). Dept. of Geosciences

    2008-07-01

    Seismic surveys in the southeast part of the Voring plateau on the Norwegian continental shelf have revealed hundreds of pockmarks and mounds which appear to be the seabed terminations of chimney-like structures. The seismic characteristics are very similar to chimneys in the accretionary complex off Vancouver Island, Canada. The pockmarks are sites of methane seeps colonized by chemosynthetic biota. There is extensive development of authigenic carbonate within the pockmarks. There are many indicators that free gas exists beneath the base of the gas hydrate stability zone (GHSZ). The observed thinning of the time intervals between reflectors in the flanks of chimneys could be caused by the presence of higher velocity material such as hydrate or authigenic carbonate. Evidence for the presence of hydrate was obtained from cores at 5 locations during a seismic survey conducted in 2006. Two of these pockmarks, each about 300-m wide with active seeps within them, were the sites of high-resolution seismic experiments using Ocean-Bottom Seismic recorders with 100-m separation to investigate the 3-D variation in their structure and properties. Travel-time tomography was used to detail the variation in Vp and Vs within and around the chimneys. It was concluded that the material within the CNE03 chimney that gave a higher seismic velocity could be carbonate or hydrate. Coring of hydrate from this feature favours the presence of hydrate. It was suggested that on average, hydrate may occupy up to 35 per cent of the pore space. The bending of strata in the flanks is partly deformational in origin, implying that the chimney was created by some forceful process, and now acts as a pathway for methane-rich fluid flow. The strata in the flanks of the G11 pockmark do not bend upwards. The pockmarks are underlain by a zone of locally higher content of free gas, approximately 5 km across. The chimneys beneath the pockmarks penetrate this zone. Many other smaller chimney-like structures

  12. Numerical Study of Severe Accidents on Containment Venting Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Na Rae; Bang, Young Suk; Park, Tong Kyu; Lee, Doo Yong [FNC Technology Co., Yongin (Korea, Republic of); Choi, Yu Jung; Lee, Sang Won; Kim, Hyeong Taek [KHNP-CRI, Daejeon (Korea, Republic of)

    2014-10-15

    Under severe accident, the containment integrity can be challenged due to over-pressurization by steam and non-condensable gas generation. According to Seismic Probabilistic Safety Assessment (PSA) result, the late containment failure by over-pressurization has been identified as the most probable containment failure mode. In addition, the analyses of Fukushima nuclear power plant accident reveal the necessity of the proper containment depressurization to prevent the large release of the radionuclide to environment. Containment venting has been considered as an effective approach to maintain the containment integrity from over-pressurization. Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. To ensure the containment integrity under over-pressure conditions, it is crucial to conduct the containment vent in a timely manner with a sufficient discharge flow rate. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. The purpose of this study is to identify the effective venting conditions for preventing the containment over-pressurization and investigate the vent flow characteristics to minimize the consequence of the containment ventilation.. In order that, thermodynamic behavior of the containment and the discharged flow depending on different vent strategies are analyzed and compared. The representative accident scenarios are identified by reviewing the Level 2 PSA result and the sensitivity analyses with varying conditions (i.e. vent line size and vent initiation pressure) are conducted. MAAP5 model for the OPR1000 Korea nuclear power plant has been used for severe accident simulations. Containment venting can be an effective strategy to prevent the significant failure of the containment due to over-pressurization. However, it should be carefully conducted because the vented

  13. Numerical Study of Severe Accidents on Containment Venting Conditions

    International Nuclear Information System (INIS)

    Under severe accident, the containment integrity can be challenged due to over-pressurization by steam and non-condensable gas generation. According to Seismic Probabilistic Safety Assessment (PSA) result, the late containment failure by over-pressurization has been identified as the most probable containment failure mode. In addition, the analyses of Fukushima nuclear power plant accident reveal the necessity of the proper containment depressurization to prevent the large release of the radionuclide to environment. Containment venting has been considered as an effective approach to maintain the containment integrity from over-pressurization. Basic idea of containment venting is to relieve the pressure inside of the containment by establishing a flow path to the external environment. To ensure the containment integrity under over-pressure conditions, it is crucial to conduct the containment vent in a timely manner with a sufficient discharge flow rate. It is also important to optimize the vent line size to prevent additional risk of leakage and to install at the site with limited space availability. The purpose of this study is to identify the effective venting conditions for preventing the containment over-pressurization and investigate the vent flow characteristics to minimize the consequence of the containment ventilation.. In order that, thermodynamic behavior of the containment and the discharged flow depending on different vent strategies are analyzed and compared. The representative accident scenarios are identified by reviewing the Level 2 PSA result and the sensitivity analyses with varying conditions (i.e. vent line size and vent initiation pressure) are conducted. MAAP5 model for the OPR1000 Korea nuclear power plant has been used for severe accident simulations. Containment venting can be an effective strategy to prevent the significant failure of the containment due to over-pressurization. However, it should be carefully conducted because the vented

  14. Measurement of the velocity field behind the automotive vent

    Directory of Open Access Journals (Sweden)

    Jedelský Jan

    2012-04-01

    Full Text Available Passenger comfort in a personal vehicle cabin strongly depends on the appropriate function of the cabin ventilation system. Great attention is therefore paid to the effective functioning of the automotive vents. Various techniques can be employed to evaluate the proper formation of the flow behind the ventilation outlet. Constant Temperature Anemometry (CTA was used in our case for accurate measurement of the velocity field and consequent assessment of jet boundaries and jet axis. A novel methodology has been developed for the simulation of realistic conditions when using just a single vent under laboratory conditions instead of the complete vehicle ventilation system. A special technique has also been developed for determination of the terminal inclination angles of vent vanes for the particular vent type, which can be completely closed by the adjustable horizontal vanes. A two wire CTA probe was used for measurement of the actual velocity over predefined planes, which were specified according to smoke visualization. Mean velocities and the turbulence intensity were evaluated on the basis of the obtained data and are presented in a form of charts. Both jet boundary and orientation of the jet for a given setup of the vent are important characteristics of particular vent type. Effectiveness of different vents could be compared using our methodology and hence contribute to development of advanced ventilation system.

  15. Measurement of the velocity field behind the automotive vent

    Science.gov (United States)

    Ležovič, Tomáš; Lízal, František; Jedelský, Jan; Jícha, Miroslav

    2012-04-01

    Passenger comfort in a personal vehicle cabin strongly depends on the appropriate function of the cabin ventilation system. Great attention is therefore paid to the effective functioning of the automotive vents. Various techniques can be employed to evaluate the proper formation of the flow behind the ventilation outlet. Constant Temperature Anemometry (CTA) was used in our case for accurate measurement of the velocity field and consequent assessment of jet boundaries and jet axis. A novel methodology has been developed for the simulation of realistic conditions when using just a single vent under laboratory conditions instead of the complete vehicle ventilation system. A special technique has also been developed for determination of the terminal inclination angles of vent vanes for the particular vent type, which can be completely closed by the adjustable horizontal vanes. A two wire CTA probe was used for measurement of the actual velocity over predefined planes, which were specified according to smoke visualization. Mean velocities and the turbulence intensity were evaluated on the basis of the obtained data and are presented in a form of charts. Both jet boundary and orientation of the jet for a given setup of the vent are important characteristics of particular vent type. Effectiveness of different vents could be compared using our methodology and hence contribute to development of advanced ventilation system.

  16. REE and Sr-Nd isotope characteristics of hydrothermal chimney at Jade area in the Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    LIU Yanguang; MENG Xianwei; FU Yunxia

    2004-01-01

    Hydrothermal chimney is a product of hydrothermal activity on the seabed. Chimney samples dredged from Jade hydrothermal area in Izena depression of the Okinawa Trough, are characterized by relatively enriched light rare earth elements (LREE) and strongly positive Eu anomalies. 87Sr/86Sr and 143Nd/144Nd of these samples are exactly between those of seawater and of acidic pumice, averaged at 0.708928 and 0.512292, respectively. These characteristics imply that the main source of hydrothermal sulfide at Jade area is possibly the undersurface acidic rocks. The mineralizing mechanism can be summarized as follows: Large amount of mineralized material would be leached out and LREEenriched hydrothermal solution would be subsequently produced as a result of thermo-chemical exchange reaction between acidic volcanic rocks and heated seawater that penetrated in advance from upper water mass. The spurting out from the seabed and quickly crystallizing in the seawater of hydrothermal solution are responsible for the formation of Cu-Zn sulfide and barite-amorphous SiO2 minerals that are characterized by enriched LREE and positively strong Eu anomalies.

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

    Science.gov (United States)

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

    2015-05-01

    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.

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

    Directory of Open Access Journals (Sweden)

    Pech Ondrej

    2015-01-01

    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.

  19. 40 CFR 63.7892 - What are my inspection and monitoring requirements for process vents?

    Science.gov (United States)

    2010-07-01

    ... requirements for process vents? 63.7892 Section 63.7892 Protection of Environment ENVIRONMENTAL PROTECTION... Process Vents § 63.7892 What are my inspection and monitoring requirements for process vents? For each closed vent system and control device you use to comply with § 63.7890(b), you must monitor and...

  20. 40 CFR 63.450 - Standards for enclosures and closed-vent systems.

    Science.gov (United States)

    2010-07-01

    ...-vent systems. 63.450 Section 63.450 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Standards for enclosures and closed-vent systems. (a) Each enclosure and closed-vent system specified in §§ 63.443(c), 63.444(b), and 63.445(b) for capturing and transporting vent streams that contain...

  1. 30 CFR 250.1160 - When may I flare or vent gas?

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may I flare or vent gas? 250.1160 Section..., Venting, and Burning Hydrocarbons § 250.1160 When may I flare or vent gas? (a) You must request and receive approval from the Regional Supervisor to flare or vent natural gas at your facility, except in...

  2. 40 CFR 63.172 - Standards: Closed-vent systems and control devices.

    Science.gov (United States)

    2010-07-01

    ... olfactory indications of leaks. (2) If the vapor collection system or closed-vent system is constructed of... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Standards: Closed-vent systems and... Standards: Closed-vent systems and control devices. (a) Owners or operators of closed-vent systems...

  3. The Living Periodic Table

    Science.gov (United States)

    Nahlik, Mary Schrodt

    2005-01-01

    To help make the abstract world of chemistry more concrete eighth-grade students, the author has them create a living periodic table that can be displayed in the classroom or hallway. This display includes information about the elements arranged in the traditional periodic table format, but also includes visual real-world representations of the…

  4. Table Tennis Club

    CERN Document Server

    Table Tennis Club

    2011-01-01

    CERN Table Tennis Tournament Saturday 20th August 2011 at 13.30 at the CERN/Meyrin TT club (underneath the Piscine de Livron, rue de Livron 2, 1217 Meyrin) Details: http://cern.ch/club-TableTennis Registration: jean-pierre.revol@cern.ch Open to all CERN staff, visitors, summer students, and families

  5. Deposition of talc - kerolite-smectite - smectite at seafloor hydrothermal vent fields: Evidence from mineralogical, geochemical and oxygen isotope studies

    Science.gov (United States)

    Dekov, V.M.; Cuadros, J.; Shanks, Wayne C.; Koski, R.A.

    2008-01-01

    controls on the precipitation of this sequence are the silica activity and Mg/Al ratio (i.e. the degree of mixing of seawater with hydrothermal fluid). Higher silica activity favors the formation of talc relative to tri-octahedral smectite. Vent structures and sedimentary cover preclude complete mixing of hydrothermal fluid and ambient seawater, resulting in lower Mg/Al ratios in the interior parts of the chimneys and deeper in the sediment which leads to the precipitation of phyllosilicates with lower Mg contents. Talc and kerolite-smectite have very low trace- and rare earth element contents. Some exhibit a negative or flat Eu anomaly, which suggests Eu depletion in the original hydrothermal fluid. Such Eu depletion could be caused by precipitation of anhydrite or barite (sinks for Eu2+) deeper in the system. REE abundances and distribution patterns indicate that chlorite and chlorite-smectite are hydrothermal alteration products of the background turbiditic sediment. ?? 2007 Elsevier B.V. All rights reserved.

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

    Directory of Open Access Journals (Sweden)

    Steven L Chown

    2012-01-01

    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.

  7. Manipulating liquid plugs in microchannel with controllable air vents

    OpenAIRE

    Liu, Hao-Bing; Ting, Eng Kiat; Gong, Hai-Qing

    2012-01-01

    An air venting element on microchannel, which can be controlled externally and automatically, was demonstrated for manipulating liquid plugs in microfluidic systems. The element’s open and closed statuses correspond to the positioning and movement of a liquid plug in the microchannel. Positioning of multiple liquid plugs at an air venting element enabled the merging and mixing of the plugs. Besides these basic functions, other modes of liquid plug manipulations including plug partitioning, mu...

  8. THE DIVERSITY AND DISTRIBUTION OF ARCHAEA IN GUAYMAS DEEP-SEA HYDROTHERMAL VENT%瓜伊马斯深海热液口古菌分布及多样性研究

    Institute of Scientific and Technical Information of China (English)

    鲁书林; 何莹; 王风平

    2013-01-01

    Due to the dramatic gradients of temperature (up to above 400℃ ) ,pH and chemicals, deep-sea hydrothermal vents have been the focus for studies of the origin and evolution of life on earth and the subseafloor hydrothermal living system is ideal for exploring the origin and evolution of deep-sea life. In this study, the diversity of archaea was investigated at high temperature sediments and chimney from Guaymas hydrothermal vent using cultured-independent technique. Environmental total DNA were directly extracted and used for the quantification and construction of archaea 16S rRNA gene libraries. A total of 79 and 80 clean sequences were obtained from the sediment and chimney samples. Quantitative PCR analysis revealed that the amounts of archaea present in the sediment and chimney were about 1.47×109 copies/g ( wet weight) and 5. 29 × 108 copies/g ( wet weight), respectively. All the clone libraries had the coverage C value more than 80%, the archaea diversity of sediment sample was higher than the chimney. The compositions of archaea community were different between two samples, yet most of archaea belonged to the thermophilic/hyperthermophilic microorganism because of the high temperature environment. In the sediments, most of archaea came from Crenarchaeota domain and the two most dominant groups were the Miscellaneous Crenarchaeota Group ( MCG,43. 04% )and Hot Water Crenarchaeota Group Ⅰ ( HWCG Ⅰ , 20. 25% ) confirmed by archaeal 16S rRNA gene components. The remaining sequences from the sediment sample were related to members of Thermoprotei ( 7. 59%) , Korarchaeota ( 1. 26%) , Methanosarcinales (1. 26%) , Marine Benthic Group D/Deep Hydrothermal Vent Euryarchaeota ( MBGD/DHVE 1, 8. 86%) , DHVE 9 ( 5. 06%) , Miscellaneous Euryarchaeota Group ( MEG, 2. 53%). While the Euryarchaeota domain dominated the chimney sample, in which Thermococcales (47.5%), Marine Benthic Group D ( MBGD )/Deep Hydrothermal Vent Euryarchaeota 1 ( DHVE 1) ( MBGD/DHVE 1

  9. Numerical Modeling of Two-Phase Flow at the Main Endeavour Field, Juan de Fuca Ridge: Quasi-Steady State and Thermal Decline of the Vent Field

    Science.gov (United States)

    Singh, S.; Lowell, R. P.; Lewis, K. C.

    2012-12-01

    The Main Endeavour Field (MEF) on the Juan de Fuca Ridge consists of a large number of chimney structures occupying an area approximately 400 m x 150 m along the ridge axis. For nearly a decade, the MEF exhibited quasi-steady north-south trending spatial gradients of both temperature and salinity. We have constructed 2-D across-axis numerical models of two-phase flow using the code FISHES to investigate possible causes for this variation. We considered the effect of bottom boundary temperature and both a homogeneous permeability structure and a geometry incorporating a more-permeable layer 2A. From these model results we argue that such a trend is more likely to be the result of heterogeneous permeability structure of the shallow oceanic crust than a result of bottom boundary temperature variations. After a magmatic event in 1999, this trend was disrupted; and thermal data using the Autonomous Benthic Explorer (ABE) indicates that there has been a significant decline in the heat output from a value of approximately 450 MW in 2000 to approximately 300 MW in 2004. In the southern part of the vent field, vent salinities have also increased from values well below those of seawater to values close to seawater. We therefore extend our investigation to include the effect of a temporally-decaying basal heat flow, which may result from cooling, crystallizing magma chamber, on the system. Our aim is to determine whether such a phenomenon could cause the observed rapid decline of heat flow and changes in vent salinity at the MEF. We find that the thermal inertia in the system is such that changes in basal heat flow would be difficult to detect in the given time frame, if magma replenishment ceased following the 1999 magmatic event. The time delay between changes in bottom conditions and the observed decay in observed heat output suggests that the 1999 event represented a small replenishment event and that the AMC may have begun cooling some time before that. Moreover, because

  10. Geomicrobiology of Deep-Sea Hydrothermal Vents

    Science.gov (United States)

    Jannasch, Holger W.; Mottl, Michael J.

    1985-08-01

    During the cycling of seawater through the earth's crust along the midocean ridge system, geothermal energy is transferred into chemical energy in the form of reduced inorganic compounds. These compounds are derived from the reaction of seawater with crustal rocks at high temperatures and are emitted from warm (bacteria use these reduced chemical species as sources of energy for the reduction of carbon dioxide (assimilation) to organic carbon. These bacteria form the base of the food chain, which permits copious populations of certain specifically adapted invertebrates to grow in the immediate vicinity of the vents. Such highly prolific, although narrowly localized, deep-sea communities are thus maintained primarily by terrestrial rather than by solar energy. Reduced sulfur compounds appear to represent the major electron donors for aerobic microbial metabolism, but methane-, hydrogen-, iron-, and manganese-oxidizing bacteria have also been found. Methanogenic, sulfur-respiring, and extremely thermophilic isolates carry out anaerobic chemosynthesis. Bacteria grow most abundantly in the shallow crust where upwelling hot, reducing hydrothermal fluid mixes with downwelling cold, oxygenated seawater. The predominant production of biomass, however, is the result of symbiotic associations between chemolithotrophic bacteria and certain invertebrates, which have also been found as fossils in Cretaceous sulfide ores of ophiolite deposits.

  11. Design criteria and concepts for vented containment systems

    International Nuclear Information System (INIS)

    Accident sequences from WASH-1400 were selected and analyzed with the MARCH/CORRAL code to provide an envelope of design conditions. The time-dependent pressures and temperatures in containment were calculated as were the concentrations of steam, noncondensible gases, and airborne fission products in the containment atmosphere. The phenomenon found to be most challenging to containment integrity was a pressure spike resulting from rapid steam generation and/or hydrogen burning. The peak pressures in some sequences exceed the likely failure pressure. Conceptual designs were developed for preserving containment integrity. These include containment pressure relief or depressurization with various venting rates. Anticipatory venting, venting to the atmosphere, venting to a separate building, and venting followed by recirculation back into containment are considered. The effects of these schemes on the important system parameters were identified. The advantages and disadvantages of alternative schemes and their implications for the design of filtration equipment are discussed. For each venting strategy several levels of filtering effectiveness were considered. The simplest option developed is a once-through gravel-filled suppression pool. More sophisticated options involved sand filters, molecular sieves, charcoal adsorbers and HEPA filters. Results of accident consequence calculations using the CRAC code indicate the relatively simple options can provide substantial reductions in consequences of certain accident sequences. 12 figures

  12. Experimental Study of Effect of Vents in Thermal Ventilation

    Institute of Scientific and Technical Information of China (English)

    LIU Dong; LIU Xiao-yu; ZHUANG Jiang-ting; SHEN Hui

    2009-01-01

    The effects of vents on thermal ventilation to save energy in the cold roUing workshop of Baosteel were investigated.According to the scale modeling theory,a small chamber was established.The details about construction of experiment On thermal ventilation and the preparation and arrangement of apparatus were dis-cussed,and then the effects of vents on thermal ventilation were studied through experiments,which includes the temperature distribution,the volume of ventilation,the temperature difference between inlets and outlets,the neutral plane,and the effective thermal coefficient of thermal natural ventilation.Based on this,the effects of natural ventilation based on varied area of inlets and oudets and those of vents on one side and on different sides were compared.According to the experiments,the area of inlet vents and outlet vents affect the tempera-ture distribution in chamber, and their effects on ventilation volume are difierent,but the effects of vents in sin-gle side or different sides aare the same under the condition that only thermal ventilation is considered.

  13. Hydrogen is an energy source for hydrothermal vent symbioses.

    Science.gov (United States)

    Petersen, Jillian M; Zielinski, Frank U; Pape, Thomas; Seifert, Richard; Moraru, Cristina; Amann, Rudolf; Hourdez, Stephane; Girguis, Peter R; Wankel, Scott D; Barbe, Valerie; Pelletier, Eric; Fink, Dennis; Borowski, Christian; Bach, Wolfgang; Dubilier, Nicole

    2011-08-11

    The discovery of deep-sea hydrothermal vents in 1977 revolutionized our understanding of the energy sources that fuel primary productivity on Earth. Hydrothermal vent ecosystems are dominated by animals that live in symbiosis with chemosynthetic bacteria. So far, only two energy sources have been shown to power chemosynthetic symbioses: reduced sulphur compounds and methane. Using metagenome sequencing, single-gene fluorescence in situ hybridization, immunohistochemistry, shipboard incubations and in situ mass spectrometry, we show here that the symbionts of the hydrothermal vent mussel Bathymodiolus from the Mid-Atlantic Ridge use hydrogen to power primary production. In addition, we show that the symbionts of Bathymodiolus mussels from Pacific vents have hupL, the key gene for hydrogen oxidation. Furthermore, the symbionts of other vent animals such as the tubeworm Riftia pachyptila and the shrimp Rimicaris exoculata also have hupL. We propose that the ability to use hydrogen as an energy source is widespread in hydrothermal vent symbioses, particularly at sites where hydrogen is abundant. PMID:21833083

  14. Decision table languages and systems

    CERN Document Server

    Metzner, John R

    1977-01-01

    ACM Monograph Series: Decision Table Languages and Systems focuses on linguistic examination of decision tables and survey of the features of existing decision table languages and systems. The book first offers information on semiotics, programming language features, and generalization. Discussions focus on semantic broadening, outer language enrichments, generalization of syntax, limitations, implementation improvements, syntactic and semantic features, decision table syntax, semantics of decision table languages, and decision table programming languages. The text then elaborates on design im

  15. Elementary Statistics Tables

    CERN Document Server

    Neave, Henry R

    2012-01-01

    This book, designed for students taking a basic introductory course in statistical analysis, is far more than just a book of tables. Each table is accompanied by a careful but concise explanation and useful worked examples. Requiring little mathematical background, Elementary Statistics Tables is thus not just a reference book but a positive and user-friendly teaching and learning aid. The new edition contains a new and comprehensive "teach-yourself" section on a simple but powerful approach, now well-known in parts of industry but less so in academia, to analysing and interpreting process dat

  16. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation.

    Science.gov (United States)

    Teske, Andreas; de Beer, Dirk; McKay, Luke J; Tivey, Margaret K; Biddle, Jennifer F; Hoer, Daniel; Lloyd, Karen G; Lever, Mark A; Røy, Hans; Albert, Daniel B; Mendlovitz, Howard P; MacGregor, Barbara J

    2016-01-01

    The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these hydrothermal features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region.

  17. Chimney-Graft as a Bail-Out Procedure for Endovascular Treatment of an Inflammatory Juxtarenal Abdominal Aortic Aneurysm

    Directory of Open Access Journals (Sweden)

    Francesca Fratesi

    2015-01-01

    Full Text Available Inflammatory and juxtarenal Abdominal Aortic Aneurysm (j-iAAA represents a technical challenge for open repair (OR due to the peculiar anatomy, extensive perianeurysmal fibrosis, and dense adhesion to the surrounding tissues. A 68-year-old man with an 11 cm asymptomatic j-iAAA was successfully treated with elective EVAR and chimney-graft (ch-EVAR without postprocedural complications. Target vessel patency and normal renal function are present at 24-month follow-up. The treatment of j-iAAA can be technically challenging. ch-EVAR is a feasible and safe bail-out method for elective j-iAAA with challenging anatomy.

  18. COMPARISON OF VENTED AND ABSOLUTE PRESSURE TRANSDUCERS FOR WATER-LEVEL MONITORING IN HANFORD SITE CENTRAL PLATEAU WELLS

    Energy Technology Data Exchange (ETDEWEB)

    MCDONALD JP

    2011-09-08

    disequilibrium is likely limited to wells screened across the water table (i.e., open to the deep vadose zone) where the depth to water is large or a low-permeability layer occurs in the vadose zone. Such wells are a pathway for air movement between the deep vadose zone and land surface and this sustains the pressure disequilibrium between the well bore and the atmosphere for longer time periods. Barometric over-response was not observed with the absolute pressure transducers because barometric compensation was achieved by directly measuring the air pressure within the well. Users of vented pressure transducers should be aware of the over-response issue in certain Hanford Site wells and ascertain if it will affect the use of the data. Pressure disequilibrium between the well and the atmosphere can be identified by substantial air movement through the wellbore. In wells exhibiting pressure disequilibrium, it is recommended that absolute pressure transducers be used rather than vented transducers for applications that require precise automated determinations of well water-level changes in response to barometric pressure fluctuations.

  19. Thermococcus thioreducens sp. nov., a Novel Hyperthermophilic, Obligately Sulfur-Reducing Archaeon from a Deep-Sea Hydrothermal Vent

    Science.gov (United States)

    Pikuta, Elena V.; Marsic, Damien; Itoh, Takashi; Bej, Asim K.; Tang, Jane; Whitman, William B.; Ng, Joseph D.; Garriott, Owen K.; Hoover, Richard B.

    2007-01-01

    A hyperthermophilic, sulfur-reducing, organo-heterotrophic archaeon, strain OGL-20P(sup T), was isolated from 'black smoker' chimney material from the Rainbow hydrothermal vent site on the Mid-Atlantic Ridge (36.2degN, 33.9degW). The cells of strain OGL-20P(T) have an irregular coccoid shape and are motile with a single flagellum. Growth was observed within a pH range of 5.0-8.5 (optimum pH 7.0), an NaCl concentration range of 1-5%(w/v) (optimum 3%)and a temperature range of 55-94 C (optimum 83-85 C). The novel isolate is strictly anaerobic and obligately dependent upon elemental sulfur as an electron acceptor, but it does not reduce sulfate, sulfite, thiosulfate, Fe(III) or nitrate. Proteolysis products (peptone, bacto-tryptone, Casamino acids and yeast extract) are utilized as substrates during sulfur reduction. Strain OGL-20P(sup T) is resistant to ampicillin, chloram phenicol, kanamycin and gentamicin, but sensitive to tetracycline and rifampicin. The G + C content of the DNA is 52.9 mol% The 16S rRNA gene sequence analysis revealed that strain OGL-20P(sup T) is closely related to Thermococcus coalescens and related species, but no significant homology by DNA-DNA hybridization was observed between those species and the new isolate. On the basis of physiological and molecular properties of the new isolate, we conclude that strain OGL-20P(sup T) represents a new separate species within the genus Thermococcus, for which we propose the name Thermococcus thioreducens sp. nov. The type strain is OGL-20P(sup T) (=JCM 12859(exp T) = DSM 14981(exp T)=ATCC BAA-394(exp T)).

  20. Hydrogen and thiosulfate limits for growth of a thermophilic, autotrophic Desulfurobacterium species from a deep-sea hydrothermal vent.

    Science.gov (United States)

    Stewart, Lucy C; Llewellyn, James G; Butterfield, David A; Lilley, Marvin D; Holden, James F

    2016-04-01

    Hydrothermal fluids (341°C and 19°C) were collected < 1 m apart from a black smoker chimney and a tubeworm mound on the Boardwalk edifice at the Endeavour Segment in the northeastern Pacific Ocean to study anaerobic microbial growth in hydrothermal mineral deposits. Geochemical modelling of mixed vent fluid and seawater suggests the mixture was anoxic above 55°C and that low H2 concentrations (79 μmol kg(-1) in end-member hydrothermal fluid) limit anaerobic hydrogenotrophic growth above this temperature. A thermophilic, hydrogenotrophic sulfur reducer, Desulfurobacterium strain HR11, was isolated from the 19°C fluid raising questions about its H2 -dependent growth kinetics. Strain HR11 grew at 40-77°C (Topt 72-75°C), pH 5-8.5 (pHopt 6-7) and 1-5% (wt vol(-1) ) NaCl (NaClopt 3-4%). The highest growth rates occurred when S2 O3 (2-) and S° were reduced to H2 S. Modest growth occurred by NO3 (-) reduction. Monod constants for its growth were Ks of 30 μM for H2 and Ks of 20 μM for S2 O3 (2-) with a μmax of 2.0 h(-1) . The minimum H2 and S2 O3 (2-) concentrations for growth were 3 μM and 5 μM respectively. Possible sources of S2 O3 (2-) and S° are from abiotic dissolved sulfide and pyrite oxidation by O2 .

  1. VMS forms Output Tables

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These output tables contain parsed and format validated data from the various VMS forms that are sent from any given vessel, while at sea, from the VMS devices on...

  2. Setting the Periodic Table.

    Science.gov (United States)

    Saturnelli, Annette

    1985-01-01

    Examines problems resulting from different forms of the periodic table, indicating that New York State schools use a form reflecting the International Union of Pure and Applied Chemistry's 1984 recommendations. Other formats used and reasons for standardization are discussed. (DH)

  3. The Periodic Table CD.

    Science.gov (United States)

    Banks, Alton J.; Holmes, Jon L.

    1995-01-01

    Describes the characteristics of the digitized version of The Periodic Table Videodisc. Provides details about the organization of information and access to the data via Macintosh and Windows computers. (DDR)

  4. Permit.LOA table

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This table includes the effective dates by vessel and permit number for each issued letter of authorization (LOA) by the Permit Office (APSD)

  5. Building Materials Property Table

    Energy Technology Data Exchange (ETDEWEB)

    None

    2010-04-16

    This information sheet describes a table of some of the key technical properties of many of the most common building materials taken from ASHRAE Fundamentals - 2001, Moisture Control in Buildings, CMHC, NRC/IRC, IEA Annex 24, and manufacturer data.

  6. Upstream petroleum industry flaring and venting report : industry performance for year ending December 31, 2008

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-06-15

    The Energy Resources Conservation Board (ERCB) has developed recommendations for a flaring and venting management framework for the province of Alberta. This report fulfilled the ERCB's information mandate regarding flaring and venting as part of a commitment made in Directive 060 for upstream petroleum industry flaring, incineration, and venting to make flaring and venting data more accessible. It included data on upstream petroleum industry flaring and venting with particular reference to solution gas conserved, flared and vented, from 1996 to 2008; solution gas flaring and venting performance; flaring from all upstream oil and gas sources, from 2000 to 2008; venting from all upstream oil and gas sources, from 2000 to 2008; solution gas flaring and venting maps; and solution gas emissions ranking of operators for 2007. The report also provided a summary of flaring and venting from various oil and gas industry sources, such as well tests, gas plants, gas gathering systems, transmission lines, and batteries. Ranking of companies was established based on solution gas flared plus vented; solution gas flared; and solution gas vented from crude oil and bitumen batteries. The data used in the preparation of this report was submitted by companies. The report revealed that considerable progress has been made in the reduction of flaring and venting volumes for all upstream oil and gas sources. The reduction can be attributed to the decline in new conventional oil production. It can also be correlated to the decline in volumes of solution gas formerly being flared, and now being vented. Solution gas vented in 2008 was 40.7 per cent less than the 2000 venting baseline. However, in 2008, there was a 25.9 per cent increase in venting from crude bitumen batteries which can be correlated to the increase in crude bitumen production. The ERCB is continuing to work with the Clean Air Strategic Alliance to examine options to further address solution gas venting. tabs., figs.

  7. Physiological and genomic features of a novel sulfur-oxidizing gammaproteobacterium belonging to a previously uncultivated symbiotic lineage isolated from a hydrothermal vent.

    Science.gov (United States)

    Nunoura, Takuro; Takaki, Yoshihiro; Kazama, Hiromi; Kakuta, Jungo; Shimamura, Shigeru; Makita, Hiroko; Hirai, Miho; Miyazaki, Masayuki; Takai, Ken

    2014-01-01

    Strain Hiromi 1, a sulfur-oxidizing gammaproteobacterium was isolated from a hydrothermal vent chimney in the Okinawa Trough and represents a novel genus that may include a phylogenetic group found as endosymbionts of deep-sea gastropods. The SSU rRNA gene sequence similarity between strain Hiromi 1 and the gastropod endosymbionts was approximately 97%. The strain was shown to grow both chemolithoautotrophically and chemolithoheterotrophically with an energy metabolism of sulfur oxidation and O2 or nitrate reduction. Under chemolithoheterotrophic growth conditions, the strain utilized organic acids and proteinaceous compounds as the carbon and/or nitrogen sources but not the energy source. Various sugars did not support growth as a sole carbon source. The observation of chemolithoheterotrophy in this strain is in line with metagenomic analyses of endosymbionts suggesting the occurrence of chemolithoheterotrophy in gammaproteobacterial symbionts. Chemolithoheterotrophy and the presence of homologous genes for virulence- and quorum sensing-related functions suggest that the sulfur-oxidizing chomolithotrophic microbes seek animal bodies and microbial biofilm formation to obtain supplemental organic carbons in hydrothermal ecosystems.

  8. Vents Pattern Analysis at Etna volcano (Sicily, Italy).

    Science.gov (United States)

    Brancato, Alfonso; Tusa, Giuseppina; Coltelli, Mauro; Proietti, Cristina; Branca, Stefano

    2014-05-01

    Mount Etna is a composite stratovolcano located along the Ionian coast of eastern Sicily. It is characterized by basaltic eruptions, both effusive and explosive, occurred during a complex eruptive history over the last 500 ka. Flank eruptions occur at an interval of decades, mostly concentrated along the NE, S and W rift zones. A vent clustering at various scales is a common feature in many volcanic settings. In order to identify the clusters within the studied area, a spatial point pattern analysis is undertaken using vent positions, both known and reconstructed. It reveals both clustering and spatial regularity in the Etna region at different distances. The visual inspection of the vent spatial distribution suggests a clustering on the rift zones of Etna volcano. To confirm this evidence, a coarse analysis is performed by the application of Ξ2- and t-test simple statistics. Then, a refined analysis is performed by using the Ripley K-function (Ripley, 1976), whose estimator K(d), knowing the area of the study region and the number of vents, allow us to calculate the distance among two different location of events. The above estimator can be easier transformed by using the Besag L-function (Besag, 1977); the peaks of positive L(d)=[K(d)/π]1/2 -d values indicate clustering while troughs of negative values stand for regularity for their corresponding distances d (L(d)=0 indicates complete spatial randomness). Spatial pattern of flank vents is investigated in order to model the spatial distribution of likely eruptive vents for the next event, basically in terms of relative probabilities. For this, a Gaussian kernel technique is used, and the L(d) function is adopted to generate an optimal smoothing bandwidth based on the clustering behaviour of the Etna volcano. A total of 154 vents (among which 36 are reconstructed), related to Etna flank activity of the last 4.0 ka, is used to model future vent opening. The investigated region covers an area of 850 km2, divided

  9. Bus Vent Design Evolution for the Solar Dynamics Observatory

    Science.gov (United States)

    Woronowicz, Michael

    2010-01-01

    As a spacecraft undergoes ascent in a launch vehicle, its pressure environment transitions from one atmosphere to high vacuum in a matter of minutes. Venting of internal cavities is necessary to prevent the buildup of pressure differentials across cavity walls. Opposing the need to vent these volumes freely into space are thermal, optical, and electrostatic requirements for limiting or prohibiting the intrusion of unwanted energy into the same cavities. Bus vent design evolution is discussed for the Solar Dynamics Observatory. Design changes were influenced by a number of factors and concerns, such as contamination control, electrostatic discharge, changes in bus material, and driving fairing ascent pressure for a launch vehicle that was just entering service as this satellite project had gotten underway.

  10. Naked in toxic fluids: A nudibranch mollusc from hydrothermal vents

    Science.gov (United States)

    Valdés, Ángel; Bouchet, Philippe

    1998-01-01

    A new species of the nudibranch genus Dendronotus (Mollusca, Opisthobranchia) is reported from a hydrothermal vent at the Lucky Strike area, on the Mid-Atlantic Ridge. This is the first species of nudibranch recorded with certainty from a vent site. Other species of Dendronotus are distributed in temperate waters on the continental shelf of the northern hemisphere. Two factors that probably account for the occurrence of a nudibranch in this hydrothermal field are that the Lucky Strike area presents potential hydroid prey, and that nudibranchs apparently inhabit a lower activity area. It is hypothesized that the new species, which lacks eyes, is a permanent resident of vent fields on the Mid-Atlantic Ridge, but is probably not restricted to that environment.

  11. Vent Control as a Means of Enhancing Airbag Performance

    Directory of Open Access Journals (Sweden)

    Richard E. Zimmermann

    2002-01-01

    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.

  12. 燃煤电厂脱硫烟囱防腐技术创新和应用探讨%Discussion on technology innovation of coal -fired power plant desulfurization chimney corrosion and its application

    Institute of Scientific and Technical Information of China (English)

    张庆虎; 吴金土

    2015-01-01

    Through the analysis of the existing coal-fired power plant desulfurization chimney corrosion technolo-gy, summed up the basic reason desulfurization chimney corrosion failures, technological innovation ideas pro-posed chimney desulfurization corrosion.And briefly describes the use of self-vulcanized butyl rubber anti-corrosion lining for coal-fired power plant desulfurization chimney antiseptic feasibility and success stories.%通过对现行燃煤电厂脱硫烟囱防腐技术分析,总结了脱硫烟囱防腐失效的原因,提出了脱硫烟囱防腐的技术创新思路。简要介绍了采用自硫化丁基橡胶防腐衬里对燃煤电厂脱硫烟囱进行防腐的可行性和成功案例。

  13. Numerical Study on Pressure Drop Factor in the Vent-Cap of CDQ Shaft

    Institute of Scientific and Technical Information of China (English)

    Bo Song; Yanhui Feng; Xinxin Zhang

    2008-01-01

    In CDQ (Coke Dry Quenching) shaft, the vent-cap with complex structure is installed in the cone-shaped funnel under the cooling chamber. It acts to introduce cooling gas and support the descending coke in the chamber. The designing and installation of vent-cap aim to get relatively uniform gas distribution, to reduce the temperature fluctuation of cokes at outlet and realize stable operation of CDQ apparatus. In this paper, the turbulent flow of gas in vent-cap of 1:7 scale CDQ experimental shaft is numerically simulated by using CFD (Computational Fluid Dynamics) software, CFX. The velocity field, the outlet flux distribution and the pressure drop factor of each outlet under three kinds of vent-cap (called high vent-cap, low vent-cap and elliptic vent-cap) are analysed and compared. The results turn out that the pressure drop factor of elliptic vent-cap is larger than the other two vent-caps, and that the pressure drop factors of high vent-cap and low vent-cap almost have the same value.While for a specified vent-cap, the pressure drop factor with pressing brick is larger than that without pressing brick. The work in this paper is valuable for the designing of vent-cap for large-acale CDQ shaft.

  14. NASA/JPL hydrothermal vent bio-sampler

    Science.gov (United States)

    Jonsson, J.; Behar, A.; Bruckner, J.; Matthews, J.

    pagestyle empty begin document On the bottom of the oceans with volcanic activity present hydrothermal vents can be found which spew out mineral rich superheated water from the porous seafloor crust Some of these vents are situated several thousands of meters below the surface where the sunlight never reaches Yet life thrives here on the minerals and chemical compounds that the vent water brings up with it This chemosynthetic microbial community forms the basis of some of the most interesting ecosystems on our planet and could possibly also be found on other water rich planets and moons in the solar system Perhaps under the icy surface of the moon Europa there exist hydrothermal vents with such biota thriving independently of the solar energy The Hydrothermal Vent Bio-sampler HVB is a system which will be used to collect pristine samples of the water emanating from hydrothermal vents An array of temperature and flow sensors will monitor the sampling conditions This will allow for the samples to be collected from defined locations within the plume and the diversity and distribution of the chemosynthetic communities that might live there can be accurately described The samples will have to be taken without any contamination from the surrounding water thus the pristine requirement Monitoring the flow will assure that enough water has been sampled to account for the low biomass of these environments The system will be using a series of filters down to 0 2 mu m in pore size and the samples can be directly collected from the system for both culture-

  15. Multiple-vent programme to test the pressure suppression system

    International Nuclear Information System (INIS)

    Three pre-tests with a multiple vent configuration have been performed at the GKSS pressure suppression test facility. First test results indicate significant chugging events with occur periodically with 0.4 to 0.2 Hz. These events appear simultaneously in less than 10 ms at the exit of the three vent pipes and cause pressure pulses in the range of 3 bar. This report gives a short description of the test facility and presents the boundary conditions of the test facility and presents the boundary conditions of the three pre-tests, test results and a first valuation of the experimental informations. (orig.)

  16. Analysis on Venting Time of Rarefaction Wave Gun

    Institute of Scientific and Technical Information of China (English)

    WANG Ying-ze; ZHANG Xiao-bing; YUAN Yax-iong

    2008-01-01

    Based on the operation principle of rarefaction wave gun, the selection and calculation methods for venting opportune moment are invastigated. Considering property of the rarefaction wave, taking the center of muzzle section as initial calculation point, supposing that at the moment projectile arrives to the muzzle, the rarefaction wave arrives to the base of projectile, the rarefaction wave velocity along the barrel can be obtained by fitting calculation of the interior ballis-tic data of the same closed gun and reverse deduction. And then, the optimal venting time can be found out correctly based on the rarefaction wave velocity.

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

    Directory of Open Access Journals (Sweden)

    Lisa Ann Levin

    2016-05-01

    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

  18. Hydrothermal vents and methane seeps: Rethinking the sphere of influence

    Science.gov (United States)

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

    2016-01-01

    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

  19. Table Tennis Club

    CERN Multimedia

    Table Tennis Club

    2012-01-01

    The CERN Table Tennis club and the Meyrin CTT are organizing two Table Tennis workshops from 2 to 6 July and from 20 to 24 August 2012 inclusive in Meyrin. A professional would be with your children from 14.00 pm to 18.00 pm: an instructor J + S category A. Training courses with specific themes, individual courses would be given depending on the level of the child’s game, “discoveries –table tennis games” courses and games with the robot. Other activities (stretching, relaxation). Afternoons (from 18 to 20 children): 40 CHF per workshop and per child. Evenings (from 18 to 20 adults): 60 CHF per workshop and per adult. For further information, please contact Mr. Monteil : Mobile: (+33) 06 61 31 70 47 E-mail: wilfried.monteil@free.fr.

  20. Growth of gas hydrate mounds and gas chimneys of the eastern margin of Japan Sea as revealed by MBES, SSS and SBP of AUV

    Science.gov (United States)

    Matsumoto, R.; Satoh, M.; Hiromatsu, M.; Tomaru, H.; Machiyama, H.

    2010-12-01

    A series of PC, ROV and SCS surveys to study the origin and evolution of gas hydrate systems along the eastern margin of Japan Sea have identified a number of shallow GH accumulations on the mounds, 300m to 500m in diameter and 30m to 40m high, on the Umitaka spur and Joetsu knoll in Joetsu basin with the WD of 880m to 1200m (Matsumoto et al., 2005; 2009). All of the hydrate mounds develop on gas chimneys as recognized by seismic profiles, and some are associated with gigantic methane plumes, 600m to 700m high. Multi Beam Echo Sounder (MBES), Side Scan Sonar (SSS) and Sub-Bottom Profiler (SBP) of AUV Urashima have revealed ultra-high resolution topographic features and subsurface structures of the mounds and adjacent areas during the JAMSTEC YK10-08 cruise, July 2010. AUV Urashima ran over the spur and knoll at 50m to 80m above seafloor at a cruising speed of 2.4 knots. MBES and SSS mosaics demonstrate two types of mounds. One is a low swell with smooth surface and weak reflectance, while the other is characterized by rough and uneven topographic features with strong SSS images due to incrustation by methane-induced carbonate concretions and gas hydrates. SBP provides clear stratigraphic and structural relations down to 50mbsf to 80mbsf and recognizes three stratigraphic units as I: upper massive unit (5-10m thick), II: middle evenly bedded unit (15-25m thick) and III: lower slightly bedded unit (> 15-25m thick). Gas chimneys grow up toward the seafloor through Units III, II, and I. When the ceiling of gas chimney stays within Unit III or II, the mound above the chimney is either low swell or nearly flat, while the swell grows up higher when the ceiling reaches to Unit I or the seafloor. Eventually, the ceiling breaks through the seafloor and protrudes to form GH mound up to 40m to 50m high, and then start to decay probably due to mechanical collapse and chemical dissolution of gas hydrates. The ceiling of gas chimneys is often represented by high amplitude, uneven

  1. Use of Oriented Spray Nozzles to Set the Vapor-Air Flow in Rotary Motion in the Superspray Space of the Evaporative Chimney-Type Tower

    Science.gov (United States)

    Dobrego, K. V.; Davydenko, V. F.; Koznacheev, I. A.

    2016-01-01

    The present paper considers the problem of upgrading the thermal efficiency of chimney-type evaporative cooling towers due to the rotary motion of the vapor-air flow in the superspray space. To set the vapor-air flow in rotary motion, we propose to use the momentum of the sprayed water. It has been shown that the existing parameters of spray nozzles permit setting up to 30% of the water flow momentum in translatory motion, which is enough for changing considerably the aerodynamics of the vapor-air flow in the superspray space and improving the operation of the cooling tower. The optimal angle of axial inclination of the spray cone has been estimated. Recommendations are given and problems have been posed for engineering realization of the proposed technologies in a chimney-type cooling tower.

  2. Fermentative hydrogen production by a new alkaliphilic Clostridium sp (strain PROH2) isolated from a shallow submarine hydrothermal chimney in Prony Bay, New Caledonia

    OpenAIRE

    MEI, N.; Zergane, N.; Postec, A.; Erauso, G.; Oilier, A.; Payri, Claude; Pelletier, Bernard; Fardeau, Marie-Laure; Ollivier, Bernard; Quéméneur, Marianne

    2014-01-01

    The hydrogen-producing strain PROH2 pertaining to the genus Clostridium was successfully isolated from a shallow submarine hydrothermal chimney (Prony Bay, New Caledonia) driven by serpentinization processes. Cell biomass and hydrogen production performances during fermentation by strain PROH2 were studied in a series of batch experiments under various conditions of pH, temperature, NaCl and glucose concentrations. The highest hydrogen yield, 2.71 mol H-2/mol glucose, was observed at initial ...

  3. Personal child and mother carbon monoxide exposures and kitchen levels: Methods and results from a randomized trial of woodfired chimney cookstoves in Guatemala (RESPIRE)

    OpenAIRE

    Smith, Kirk R.; McCracken, John P; Thompson, Lisa; Edwards, Rufus; SHIELDS, KYRA N.; Canuz, Eduardo; Bruce, Nigel

    2009-01-01

    During the first randomized intervention trial (RESPIRE: Randomized Exposure Study of Pollution Indoors and Respiratory Effects) in air pollution epidemiology, we pioneered application of passive carbon monoxide (CO) diffusion tubes to measure long-term personal exposures to woodsmoke. Here we report on the protocols and validations of the method, trends in personal exposure for mothers and their young children, and the efficacy of the introduced improved chimney stove in reducing personal ex...

  4. Electricity production with low grade heat in thermal power plants by design improvement of a hybrid dry cooling tower and a solar chimney concept

    International Nuclear Information System (INIS)

    Highlights: • A system of a dry cooling tower and a solar chimney are recombined. • The hot flue gas is injected in the hybrid tower to maximize the power output. • Effects of the angle of the tower walls (convergent or divergent) are studied. • Effects of the collector roof slope and base ground slope are studied. • The thermal efficiency of a 250 MW power plant is increased more than 0.5%. - Abstract: In this study, an improved concept design is presented to increase the thermal efficiency of the Rankine cycle of a typical steam power plant by combining a solar chimney and a dry cooling tower. The sources of the wind energy generation, include: the rejected heat from condenser to the air entering dry cooling tower, solar radiation and the airlift pumping effect on the air flow created by the stack hot flue gas which is injected into the hybrid tower as a novel change. This research primarily focuses on the Shahid Rajaee 250 MW steam power plant to determine the velocity of generated flow at the turbine inlet; a numerical finite volume code was employed for a dry cooling tower having a base diameter and a chimney height of 250 and 200 m, respectively. Calculations have been iterated for different angles of chimney walls, slopes of collectors and the base ground to find their effects on the output power. A range of 360 kW to more than 4.4 MW power is captured by the wind turbine by changing the hybrid tower geometrical parameters. Obtained results reveal a maximum of 0.538% increase for the thermal efficiency of the fossil fuel power plant

  5. Complete Genome Sequence of the Hyperthermophilic Archaeon Pyrococcus sp. Strain ST04, Isolated from a Deep-Sea Hydrothermal Sulfide Chimney on the Juan de Fuca Ridge

    OpenAIRE

    Jung, Jong-Hyun; Lee, Ju-Hoon; Holden, James F.; Seo, Dong-Ho; Shin, Hakdong; Kim, Hae-Yeong; Kim, Wooki; Ryu, Sangryeol; Park, Cheon-Seok

    2012-01-01

    Pyrococcus sp. strain ST04 is a hyperthermophilic, anaerobic, and heterotrophic archaeon isolated from a deep-sea hydrothermal sulfide chimney on the Endeavour Segment of the Juan de Fuca Ridge in the northeastern Pacific Ocean. To further understand the distinct characteristics of this archaeon at the genome level (polysaccharide utilization at high temperature and ATP generation by a Na+ gradient), the genome of strain ST04 was completely sequenced and analyzed. Here, we present the complet...

  6. Characterization of Bacterial Communities in Deep-Sea Hydrothermal Vents from Three Oceanic Regions.

    Science.gov (United States)

    He, Tianliang; Zhang, Xiaobo

    2016-04-01

    Deep-sea hydrothermal vents are considered to be one of the most spectacular ecosystems on Earth. Microorganisms form the basis of the food chain in vents controlling the vent communities. However, the diversity of bacterial communities in deep-sea hydrothermal vents from different oceans remains largely unknown. In this study, the pyrosequencing of 16S rRNA gene was used to characterize the bacterial communities of the venting sulfide, seawater, and tubeworm trophosome from East Pacific Rise, South Atlantic Ridge, and Southwest Indian Ridge, respectively. A total of 23,767 operational taxonomic units (OTUs) were assigned into 42 different phyla. Although Proteobacteria, Actinobacteria, and Bacteroidetes were the predominant phyla in all vents, differences of bacterial diversity were observed among different vents from three oceanic regions. The sulfides of East Pacific Rise possessed the most diverse bacterial communities. The bacterial diversities of venting seawater were much lower than those of vent sulfides. The symbiotic bacteria of tubeworm Ridgeia piscesae were included in the bacterial community of vent sulfides, suggesting their significant ecological functions as the primary producers in the deep-sea hydrothermal vent ecosystems. Therefore, our study presented a comprehensive view of bacterial communities in deep-sea hydrothermal vents from different oceans. PMID:26626941

  7. 40 CFR 63.107 - Identification of process vents subject to this subpart.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Identification of process vents subject... Chemical Manufacturing Industry § 63.107 Identification of process vents subject to this subpart. (a) The... process vents associated with an air oxidation reactor, distillation unit, or reactor that is in a...

  8. 40 CFR 63.492 - Batch front-end process vents-reporting requirements.

    Science.gov (United States)

    2010-07-01

    ... 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 process vent or aggregate batch vent stream at an affected source shall submit the information...

  9. 40 CFR 63.1322 - Batch process vents-reference control technology.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents-reference control... Batch process vents—reference control technology. (a) Batch process vents. The owner or operator of a Group 1 batch process vent, as determined using the procedures in § 63.1323, shall comply with...

  10. 40 CFR 63.1327 - Batch process vents-reporting requirements.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents-reporting... Batch process vents—reporting requirements. (a) The owner or operator of a batch process vent or aggregate batch vent stream at an affected source shall submit the information specified in paragraphs...

  11. OPERATING PARAMETERS TO MINIMIZE EMISSIONS DURING ROTARY KILN EMERGENCY SAFETY VENT OPENINGS

    Science.gov (United States)

    Certain designs of hazardous waste incinerator systems include emergency safety vents (ESVs). ESVs (also called dump stacks, vent stacks, emergency by-pass stacks, thermal relief valves, and pressure relief valves) are regarded as true emergency devices. Their purpose is to vent ...

  12. 40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch process vents-recordkeeping... Batch process vents—recordkeeping provisions. (a) Group determination records for batch process vents... batch process vent subject to the group determination procedures of § 63.1323. Except for paragraph...

  13. Characterization of Bacterial Communities in Deep-Sea Hydrothermal Vents from Three Oceanic Regions.

    Science.gov (United States)

    He, Tianliang; Zhang, Xiaobo

    2016-04-01

    Deep-sea hydrothermal vents are considered to be one of the most spectacular ecosystems on Earth. Microorganisms form the basis of the food chain in vents controlling the vent communities. However, the diversity of bacterial communities in deep-sea hydrothermal vents from different oceans remains largely unknown. In this study, the pyrosequencing of 16S rRNA gene was used to characterize the bacterial communities of the venting sulfide, seawater, and tubeworm trophosome from East Pacific Rise, South Atlantic Ridge, and Southwest Indian Ridge, respectively. A total of 23,767 operational taxonomic units (OTUs) were assigned into 42 different phyla. Although Proteobacteria, Actinobacteria, and Bacteroidetes were the predominant phyla in all vents, differences of bacterial diversity were observed among different vents from three oceanic regions. The sulfides of East Pacific Rise possessed the most diverse bacterial communities. The bacterial diversities of venting seawater were much lower than those of vent sulfides. The symbiotic bacteria of tubeworm Ridgeia piscesae were included in the bacterial community of vent sulfides, suggesting their significant ecological functions as the primary producers in the deep-sea hydrothermal vent ecosystems. Therefore, our study presented a comprehensive view of bacterial communities in deep-sea hydrothermal vents from different oceans.

  14. 40 CFR 60.482-10 - Standards: Closed vent systems and control devices.

    Science.gov (United States)

    2010-07-01

    ..., audible, or olfactory indications of leaks. (2) If the vapor collection system or closed vent system is... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards: Closed vent systems and..., 2006 § 60.482-10 Standards: Closed vent systems and control devices. (a) Owners or operators of...

  15. À Table! Improving Temporal Navigation in Soccer Ranking Tables

    OpenAIRE

    Perin, Charles; Vuillemot, Romain; Fekete, Jean-Daniel

    2014-01-01

    International audience This article introduces A Table!, an enhanced soccer ranking table providing temporal navigation by combining two novel interaction techniques. Ranking tables order soccer teams represented as rows, according to values of columns containing attributes e.g., accumulated points, or number of scored goals. Because they represent a snapshot of a championship at a time t, tables are regularly updated with new results. Such updates usually change the rows order, which make...

  16. The Aerodynamic Plane Table

    Science.gov (United States)

    Zahm, A F

    1924-01-01

    This report gives the description and the use of a specially designed aerodynamic plane table. For the accurate and expeditious geometrical measurement of models in an aerodynamic laboratory, and for miscellaneous truing operations, there is frequent need for a specially equipped plan table. For example, one may have to measure truly to 0.001 inch the offsets of an airfoil at many parts of its surface. Or the offsets of a strut, airship hull, or other carefully formed figure may require exact calipering. Again, a complete airplane model may have to be adjusted for correct incidence at all parts of its surfaces or verified in those parts for conformance to specifications. Such work, if but occasional, may be done on a planing or milling machine; but if frequent, justifies the provision of a special table. For this reason it was found desirable in 1918 to make the table described in this report and to equip it with such gauges and measures as the work should require.

  17. LOCKE Detailed Specification Tables

    CERN Document Server

    Menezo, Lucia G; Gregorio, Jose-Angel

    2012-01-01

    This document shows the detailed specification of LOCKE coherence protocol for each cache controller, using a table-based technique. This representation provides clear, concise visual information yet includes sufficient detail (e.g., transient states) arguably lacking in the traditional, graphical form of state diagrams.

  18. The MSSA consequence tables

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, I.J.

    1988-01-01

    The Master Safeguards and Security Agreement (MSSA) is the mechanism through which the U.S. Department of Energy is implementing a policy of graded safeguards. Under this concept, the level of protection provided to a target is proportional to the ''cost'' of the loss of the target. Cost is measured by use of the conditional risk equation in which the protection system ineffectiveness is multiplied by the consequence to society of a successful adversary attempt. The consequences which are used in the MSSA process were developed in the summer of the 1986 by a consensus of DOE personnel and contractors. There are separate consequence tables for theft of SNM, radiological sabotage. The consequence values in the tables were deliberately not cross-normalized. The consequence values in each table correspond to a societal or DOE cost, for example, the consequence values for SNM theft compared to a normalized estimate of the expected number of fatalities from a successful use of the stolen material times an estimate of the likelihood of successfully using the material. Consequence values for radiological sabotage correspond very roughly to a similar expected fatality level. Values for industrial sabotage are an estimate of the impact on DOE weapons production or impact on the nuclear weapons stockpile. Problems have arisen in the use of these tables and are discussed in the paper.

  19. The Dynamic Force Table

    Science.gov (United States)

    Geddes, John B.; Black, Kelly

    2008-01-01

    We examine an experimental apparatus that is used to motivate the connections between the basic properties of vectors, potential functions, systems of nonlinear equations, and Newton's method for nonlinear systems of equations. The apparatus is an adaptation of a force table where we remove the center-pin and allow the center-ring to move freely.…

  20. Carbon fluxes from hydrothermal vents off Milos, Aegean Volcanic Arc, and the influence of venting on the surrounding ecosystem.

    Science.gov (United States)

    Dando, Paul; Aliani, Stefano; Bianchi, Nike; Kennedy, Hilary; Linke, Peter; Morri, Carla

    2014-05-01

    The island of Milos, in the Aegean Sea, has extensive hydrothermal fields to the east and southeast of the island with additional venting areas near the entrance to and within the central caldera. A calculation of the total area of the vent fields, based on ship and aerial surveys, suggested that the hydrothermal fields occupy 70 km2, twice the area previously estimated. The vents ranged in water depth from the intertidal to 300 m. As a result of the low depths there was abundant free gas release: in places water boiled on the seabed. The stream of gas bubbles rising through the sandy seabed drove a shallow re-circulation of bottom seawater. The majority of the water released with the gas, with a mean pH of 5.5, was re-circulated bottom water that had become acidified in contact with CO2 gas and was often diluted by admixture with the vapour phase from the deeper fluids. The major component of the free gas, 80%, was CO2, with an estimated total flux of 1.5-7.5 x 1012 g a-1. The methane flux, by comparison, was of the order of 1010 g a.-1 Using methane as a tracer it was shown that the major gas export from the vents was below the thermocline towards the southwest, in agreement with the prevailing currents. Areas of hydrothermal brine seepage occurred between the gas vents and occasional brine pools were observed in seabed depressions. Under relatively calm conditions, many of the brine seeps were covered by thick minero-bacterial mats consisting of silica and sulphur and surrounded by mats of diatoms and cyanobacteria. The minerals were not deposited in the absence of bacteria. Storms disrupted the mats, leading to an export of material to the surrounding area. Stable isotope data from sediments and sediment trap material suggested that exported POM was processed by zooplankton. The combined effects of the geothermal heating of the seabed, the large gas flux, variation in the venting and the effect of the brine seeps had a dramatic effect on the surrounding

  1. Unsteady-state VOC transport in vented waste drums

    International Nuclear Information System (INIS)

    A model of unsteady-state volatile organic compound (VOC) transport in a vented waste drum has been developed. Model predictions of the VOC concentration in the innermost layer of confinement and the drum headspace are compared to measurements in lab-scale simulated waste drums

  2. Ephemerality of discrete methane vents in lake sediments

    Science.gov (United States)

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

    2016-05-01

    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. Ending emissions: Industry targets venting, while flaring progress lauded

    Energy Technology Data Exchange (ETDEWEB)

    Lea, N.

    2003-06-01

    The progress achieved by the multi-stakeholder solution gas flaring reduction program in Alberta is discussed. The program was initiated in 1999 by the Alberta Energy and Utilities Board (EUB); within the first three years upstream flaring of solution gas was reduced by 53 per cent. Progress has also been made in reducing volumes of solution gas venting: between 1996 and 2001, there has been a 32 per cent reduction in combined flared and vented volumes of solution gas. Well test flaring has also been reduced by reduced test durations and volumes, to wit: there has been a 3 per cent reduction in flaring volumes while well tests have increased by 23 per cent. At gas plants, the decrease in flaring and venting amounted to 19 per cent, attributed mostly to industry response to the EUB's Guide 60, which incorporates many of the recommendations of the 2002 report and recommendations of the Flaring/Venting Project Team of the Clean Air Strategic Alliance (CASA).

  4. TRACB04 study on suppression pool swelling during containment venting

    International Nuclear Information System (INIS)

    Following postulated loss-of-decay-heat removal accidents in a boiling water reactor (BWR), continued steam generation in the core could lead to containment overpressurization. The Emergency Procedure Guidelines (EPG), developed jointly by the BWR Owners Group and General Electric Company, recommend operator action to vent the primary containment, as the last resort, to avoid adverse consequence to the containment or potentially to the core. The EPGs provide recommendations to be used by individual utilities in development of their plant's unique emergency operating procedures (EOPs). In formulation of the EOPs for containment venting, a number of factors must be assessed to assure that the operator actions are taken at the proper time and that the minimum consequence of venting results. Among these factors, induced pool-swell loads on containment were postulated due to such events as downcomer clearing and bulk nucleation. This paper presents the results of a study, using computer code TRACB04 of pool swelling induced by venting the containment at high pressure. TRACB04, an enhanced version of TRAC, is a best-estimate computer code for the analysis of BWR transients

  5. 46 CFR 119.450 - Vent pipes for fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... flame arresters. The flame screens must consist of a single screen of corrosion resistant wire of at least 30×30 mesh. The flame screens or flame arresters must be of such size and design as to prevent... screens or arrester elements. (e) Where a flexible vent pipe section is necessary, suitable...

  6. The filtered venting system under construction at barseback

    International Nuclear Information System (INIS)

    A filter venting containment system, bearing the acronym FILTRA will be installed at the Swedish nuclear power plant Barseback. The Barseback Power Plant is owned by the Southern Sweden Power Supply (Sydkraft AB) and has two 1700-MW boiling water reactors. The reactors are of ASEA-ATOM design with pressure suppression containments (Mark IItype). The installation of the filter venting system is a condition set by the Swedish government for a continued operating license after September 1, 1986. The construction work for the FILTRA plant, the first of its kind ever planned, will be completed at the end of 1985. The FILTRA is designed so that 99.9% of the core inventory of radioactivity, excluding inert gases, is retained in the reactor containment and filter system in the event of containment venting. Another design guideline is to achieve passive functioning of the FILTRA plant during the first 24 h of an accident. The FILTRA plant is common to the two reactors on the site and consists mainly of two systems, a venting system (pressure relief system) and a filtering system. The total cost is approximately U.S. $15 million

  7. Variation in the diets of hydrothermal vent gastropods

    Science.gov (United States)

    Govenar, Breea; Fisher, Charles R.; Shank, Timothy M.

    2015-11-01

    A prevailing paradigm of hydrothermal vent ecology is that primary consumers feed on chemoautotrophic bacteria. However, for the purposes of reconstructing vent food webs and for tracking energy flow from the generation of rock and fluid chemistry through primary/ secondary productivity and consumption to the overlying water column, it remains unclear which consumers feed on which bacteria. In paired analyses of carbon and nitrogen tissue stable isotope values with unique 16S rRNA sequences from the stomach contents, we determined that two species of gastropod grazers appear to feed on epsilon-proteobacteria, while two other species have more diverse diets, including one species that consumes alpha-proteobacteria, planctomycetes, and non-green sulfur bacteria. Different carbon fixation pathways used by epsilon- and alpha-proteobacteria may account for the variation in the carbon stable isotope values among the consumers. Furthermore, our results indicate that trophic specialization and niche partitioning may contribute to the distribution and abundance of vent-endemic gastropods and support the hypothesis that consumers in the warmer habitats commonly feed on epsilon-proteobacteria that use the rTCA cycle, while in the cooler habitats they feed on additional bacteria that use the CBB cycle. These results suggest that the phylogenetic and metabolic diversity of free-living bacteria may play an important and previously overlooked role in facilitating species coexistence among primary consumers at hydrothermal vents and other chemosynthesis-based ecosystems.

  8. Ephemerality of discrete methane vents in lake sediments

    Science.gov (United States)

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

    2016-01-01

    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.

  9. Framework for the Energetic Assessment of South and South-East Asia Fixed Chimney Bull’s Trench Kiln

    Directory of Open Access Journals (Sweden)

    Brun Niccolò Le

    2016-01-01

    Full Text Available One of the major sources of fuel consumption and greenhouse gas emission in South and South-East Asia is brick manufacturing. One of the most commonly implemented technologies for brick manufacturing in this region is the fixed chimney Bull’s trench kiln (FCBTK. This type of technology largely depends on manual labour and is very inefficient when compared to more modern technologies. Because the adoption of more advanced technologies is hindered by the socio-economical background, the much needed innovations in the brick sector are necessarily related to improving/modifying the FCBTK already operational. However, few scientific studies have been conducted on FCBTK probably due to the basic level of technological development. Such studies are however important to systematically and methodologically assess the challenges and solutions in FCBTK. In this study we develop a thermo-energetic model to evaluate the importance of the parameters pertained to FCBTK construction and operation. The prospective of this study is to build an initial thermo-energetic framework that will serve as a basis to investigate possible energetic improvements.

  10. Geophysical Signatures of cold vents on the northern Cascadia margin

    Science.gov (United States)

    Riedel, M.; Paull, C. K.; Spence, G.; Hyndman, R. D.; Caress, D. W.; Thomas, H.; Lundsten, E.; Ussler, W.; Schwalenberg, K.

    2009-12-01

    The accretionary prism of the northern Cascadia margin is a classic gas hydrate research area. Ocean Drilling Program Leg 146 and Integrated Ocean Drilling Program (IODP) Expedition 311 documented that gas hydrate is widely distributed across the margin. In recent years an increased research focus has been on cold vents, where methane gas is actively released. Two recent expeditions funded by the Monterey Bay Aquarium Research Institute (MBARI) were conducted in the area of IODP Sites U1327 and U1328. An autonomous underwater vehicle (AUV) was used to map the seafloor bathymetry followed by dives with the ROV Doc Ricketts for ground truth information of various seafloor morphological features identified. The two cruises revealed many new seafloor features indicative of methane venting that were previously unknown. Bullseye Vent (BV) has been extensively studied using seismic imaging, piston coring, heat-flow, controlled-source EM, and deep drilling. BV is seismically defined by a circular wipe-out zone but the new AUV data show that BV is rather an elongated depression. BV is associated with a shoaling in the BSR, but lacks evidence for the existence of an underlying fault in the previous data. Although a massive gas-hydrate plug was encountered within the top 40 mbsf in the IODP holes, the ROV observations only revealed some platy methane derived carbonate outcrops at the outer-most rim of the depressions, a few beds of Vesicomya clams, and no observed gas vents, which together do not indicate that BV is especially active now. Further northeast of BV, but along the same trend, active gas venting was found associated with seafloor blistering and bacterial mats suggesting that there is an underlying fault system providing a fluid flow conduit. The newly discovered vent area has few seismic line crossings; however the available seismic data surprisingly are not associated with wipe-out zones. Another prominent fault-related gas vent also was investigated during the

  11. Global Reference Tables Services Architecture

    Data.gov (United States)

    Social Security Administration — This database stores the reference and transactional data used to provide a data-driven service access method to certain Global Reference Table (GRT) service tables.

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

    OpenAIRE

    Connelly, D. P.; Copley, J.T.; Murton, B.J.; Stansfield, K.; Tyler, P. A.; German, C.R.; Van Dover, C.L.; Amon, D.; Furlong, M.; Grindlay, N.; Hayman, N; Huhnerbach, V.; Judge, M; Le Bas, T; McPhail, S

    2012-01-01

    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 ...

  13. Vent rate of superconducting magnets during quench in the Mirror Fusion Test Facility

    International Nuclear Information System (INIS)

    When a superconducting magnet goes normal, resistive heating in the conductor evaporates surrounding LHe, which must be vented. The nature and speed at which the magnet goes normal and He is vented are not subject to rigorous analysis. This paper presents vent data from an existing magnet. An approximate mathematical model is derived and fitted to the data to permit scaling of vent requirements to larger size magnets. The worst case models of the vent employed in Mirror Fusion Test Facility (MFTF) cryogenic system design are also presented

  14. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre

    OpenAIRE

    Connelly, Douglas P.; Copley, Jaonathan T.; Murton, Bramley J.; Stansfield, Kate; Tyler, Paul A.; German, Cristopher R.; Van Dover, Cindy L.; Amon, Diva; Furlong, Maaten; Grindlay, Nancy; Hayman, Nicholas; Hühnerbach, Veit; Judge, Maria; Le Bas, Tim; McPhail, Stephen

    2012-01-01

    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 ...

  15. Heat flux measured acoustically at Grotto Vent, a hydrothermal vent cluster on the Endeavour Segment, Juan de Fuca Ridge

    Science.gov (United States)

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

    2013-12-01

    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, https://sites.google.com/a/uw.edu/covis/) is currently connected to the Endeavour node of the NEPTUNE Canada observatory network (http://www.neptunecanada.ca) 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).

  16. Tissot's table of logarithms (ca. 1880)

    OpenAIRE

    Roegel, Denis

    2011-01-01

    Tissot's table, only in manuscript form, is a table of powers, subdividing the interval from 1 to 10 in 100000 intervals. It is supplemented by the sines, overlayed on the same table. This composed table is reconstructed here.

  17. Biophenols in table olives.

    Science.gov (United States)

    Blekas, Georgios; Vassilakis, Constantinos; Harizanis, Constantinos; Tsimidou, Maria; Boskou, Dimitrios G

    2002-06-19

    Unprocessed olives are well-known sources of phenolic antioxidants with important biological properties. Processing methods to prepare table olives may cause a reduction of valuable phenols and may deprive the food of precious biological functions. The present work was undertaken to evaluate table olives produced in Greece as sources of biophenols. Commercially available olives were analyzed for their total phenol content by using the Folin-Ciocalteu reagent and for individual phenols by RP-HPLC. Samples were Spanish-style green olives in brine, Greek-style naturally black olives in brine, and Kalamata olives in brine. Most of the types of olives analyzed were found to be good sources of phenols. Hydroxytyrosol, tyrosol, and luteolin were the prevailing phenols in almost all of the samples examined. High levels of hydroxytyrosol were determined mainly in Kalamata olives and Spanish-style green olives, cultivar Chalkidiki (250-760 mg/kg). PMID:12059143

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

    Science.gov (United States)

    Chan, Benny Kwok Kan; Wang, Teng-Wei; Chen, Pin-Chen; Lin, Chia-Wei; Chan, Tin-Yam; Tsang, Ling Ming

    2016-01-01

    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. PMID:26849440

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Discovery and Distribution of Black Smokers on the Western Galapagos Spreading Center: Implications for Spatial and Temporal Controls on High Temperature Venting at Ridge/Hotspot Intersections

    Science.gov (United States)

    Haymon, R. M.; Anderson, P. G.; Baker, E. T.; Resing, J. A.; White, S. M.; MacDonald, K. C.

    2006-12-01

    flows of visually-similar ages (estimated to be tens-to-hundreds of years old). Possibly a volcanic pulse may have activated the hotspot- affected western GSC, and powered contemporaneous hydrothermal vents that now are waning. It may be that hotspots produce episodes of near-synchronous, extensive ridge volcanism and hydrothermal activity, followed by periods of quiescence. This idea is consistent with: the episodic eruption histories of Hawaii and Iceland; variably anomalous hydrothermal plume incidence (low on RR, SEIR, GSC; high on Mid-Atlantic Ridge near Azores hotspot); models of episodic melt extraction from mantle plumes; and evidence for magma propagation along hotspot-influenced ridges. Our hypothesis potentially can be tested by studies of gene flow between animal communities located on either side of the Galapagos hotspot, and by dating of GSC hydrothermal chimneys and the lava flows on which they are constructed.

  1. Table Tennis Club

    CERN Document Server

    Table Tennis Club

    2012-01-01

    2012 CERN Table Tennis Tournament As the campaign launched by the CERN medical service “Move! & Eat better” is designed in particular to encourage people at CERN to take more regular exercise, the CERN Table Tennis Club, with its traditional CERN Table Tennis Tournament is providing an excellent opportunity to practice moving. The tournament will take place at the Meyrin CTT, 2 rue de Livron, Saturday August 25, 2012, in the afternoon (starting at 13:30). It is open to all CERN staff, users, visitors and families, including of course summer students, who are strongly encouraged to participate. In order to register, simply send an E-mail to Jean-Pierre Revol (jean-pierre.revol@cern.ch). You may also find useful information on the Club Web page http://www.cern.ch/tabletennis CERN 2011 champion Savitha Flaecher, between the finalist Bertrand Mouches on her left, the winner of the consolation draw on her right (Sudarshan Paramesvaran), and far left, Denis Moriaud (semi-finalist a...

  2. Sulfur Isotope Geochemistry of the Lost City Hydrothermal Vent Fluids

    Science.gov (United States)

    Frueh-Green, G. L.; Bernasconi, S. M.; Butterfield, D. A.; Kelley, D. S.

    2004-12-01

    At the Lost City Hydrothermal Vent Field (Mid-Atlantic Ridge, 30° N), reactions between seawater and ultramafic rocks produce high alkaline (pH 9 to 11) fluids that are venting at temperatures of 40 to 90° C and result in the formation of up to 60m tall carbonate-brucite structures. The fluids are enriched in hydrogen, methane and other hydrocarbons, and support dense microbial communities. We present sulfur isotope data of dissolved sulfate and coexisting sulfide in the fluids venting at Lost City, which together with C-isotope data provide constraints on the links between chemical and biological processes associated with serpentinization. The sulfur isotope composition of sulfate increases from seawater values of +21‰ (VCDT) in fluids with sulfate concentrations of 28 mM to values of up to +30‰ in the low sulfate-, high pH end-member hydrothermal fluids. Sulfide concentrations range between 50 and 2780 micromolar. Sulfur isotope compositions of the sulfides lie in a narrow range of +34 to +37‰ (VCDT) and show no clear correlation with concentrations. The isotopic compositions of dissolved inorganic carbon vary between -0.5‰ (VPDB) in the high sulfate samples and -18‰ in the low sulfate samples. This covariance indicates active sulfate reduction in the vent structures and/or in the shallow serpentinite subsurface. Sulfate reduction likely contributes to the variability of carbon isotope compositions observed in both the dissolved inorganic carbon and the carbonate minerals forming the structures. These data, together with C- and O-isotope data of the vent structures, provide evidence that methane oxidation coupled with sulfate reduction during mixing of the more pristine, hydrogen and methane-rich hydrothermal end-member fluids with seawater is an important process in hydrothermal carbonate precipitation at Lost City. Our results are consistent with previous microbiological and organic geochemical studies, which indicate a close association of methane

  3. Quantitative spatiotemporal characterization of methane venting from lake sediments

    Science.gov (United States)

    Scandella, B.; Pillsbury, L.; Weber, T.; Ruppel, C. D.; Hemond, H.; Juanes, R.

    2014-12-01

    Methane is a potent greenhouse gas, and the production and emission of methane from sediments in inland waters and shallow oceans both contributes to and may be exacerbated by climate change. In some of these shallow-water settings, methane fluxes are often controlled by episodic free-gas venting. The fraction of the methane released from the sediments that bypasses dissolution in the water column and reaches the atmosphere impacts the magnitude of the climate forcing, and this fraction depends critically on the mode and spatiotemporal characteristics of the bubble releases. The spacing and persistence of the gas vents may be determined by the heterogeneity of the methane source, but within regions of uniform methanogenesis they arise from the competition between mechanisms driving lateral and vertical transport of methane in the sediments. Here, we present measurements of the spacing, persistence and variability in intensity of methane vents within a wide area of lake sediments (~400 m2) and over a multi-month period. The measurements were made using a fixed-location Imagenex DeltaT 837B multibeam sonar, which was calibrated to quantify gas fluxes with unprecedented spatial and temporal resolution (~0.5 m, 6 Hz). Drops in hydrostatic pressure were a characteristic trigger for the sonar-detected ebullition events, and the episodicity of the fluxes is reproduced with a mechanistic numerical model of methane venting through dynamic conduits that dilate in response to hydrostatic unloading. The spatial characteristics of the sonar-detected vents inform conceptual and mathematical models of methane transport and release from deformable sediments, as well as the uncertainty associated with upscaling. Taken together, these results point towards a better understanding of the microscale processes controlling methane venting from deformable sediments, as well as their impact on large-scale methane fluxes from shallow-water bodies. Figure: Top: time series of daily sonar

  4. Interactive Conversion of Web Tables

    Science.gov (United States)

    Padmanabhan, Raghav Krishna; Jandhyala, Ramana Chakradhar; Krishnamoorthy, Mukkai; Nagy, George; Seth, Sharad; Silversmith, William

    Two hundred web tables from ten sites were imported into Excel. The tables were edited as needed, then converted into layout independent Wang Notation using the Table Abstraction Tool (TAT). The output generated by TAT consists of XML files to be used for constructing narrow-domain ontologies. On an average each table required 104 seconds for editing. Augmentations like aggregates, footnotes, table titles, captions, units and notes were also extracted in an average time of 93 seconds. Every user intervention was logged and audited. The logged interactions were analyzed to determine the relative influence of factors like table size, number of categories and various types of augmentations on the processing time. The analysis suggests which aspects of interactive table processing can be automated in the near term, and how much time such automation would save. The correlation coefficient between predicted and actual processing time was 0.66.

  5. The influence of vent fluid chemistry on trophic structure at two deep-sea hydrothermal vent fields on the Mid-Cayman Rise

    Science.gov (United States)

    Bennett, Sarah; Van Dover, Cindy; Coleman, Max

    2014-05-01

    The two known deep-sea hydrothermal vent fields along the Mid-Cayman Rise are separated by a distance of only 21 km, yet their chemistry and faunal diversity are distinct. The deeper of the two vent fields, Piccard (with active venting from Beebe Vents, Beebe Woods and Beebe Sea), at 4980 m is basalt hosted. The shallower vent field, Von Damm, at 2300 m appears to have an ultramafic influence. The Von Damm vent field can be separated into two sites: The Spire and The Tubeworm Field. The dominant vent fluids at the Tubeworm Field are distinct from those at the Spire, as a result of fluid modification in the sub-surface. Von Damm and Piccard vent fields support abundant invertebrates, sharing the same biomass-dominant shrimp species, Rimicaris hybisae. Although there are some other shared species (squat lobsters (Munidopsis sp.) and gastropods (Provanna sp. and Iheyaspira sp.)) between the vent fields, they are much more abundant at one site than the other. In this study we have examined the bulk carbon, nitrogen and sulfur isotope composition of microbes and fauna at each vent field. With these data we have deduced the trophic structure of the communities and the influence of vent fluid chemistry. From stable isotope data and end-member vent fluid chemistry, we infer that the basis of the trophic structure at Piccard is dominated by sulfur, iron, and hydrogen-oxidizing microbial communities. In comparison, the basis of the Von Damm trophic structure is dominated by microbial communities of sulfur and hydrogen oxidizers, sulfate reducers and methanotrophs. This microbial diversity at the base of the trophic structure is a result of chemical variations in vent fluids and processes in the sub-surface that alter the vent fluid chemistry. These differences influence higher trophic levels and can be used to explain some of the variability as well as similarity in fauna at the vent sites. Part of this work was performed at the Jet Propulsion Laboratory, California

  6. Metagenome and Metatranscriptome Revealed a Highly Active and Intensive Sulfur Cycle in an Oil-Immersed Hydrothermal Chimney in Guaymas Basin

    OpenAIRE

    He, Ying; Feng, Xiaoyuan; Fang, Jing; Zhang, Yu; Xiao, Xiang

    2015-01-01

    The hydrothermal vent system is a typical chemosynthetic ecosystem in which microorganisms play essential roles in the geobiochemical cycling. Although it has been well-recognized that the inorganic sulfur compounds are abundant and actively converted through chemosynthetic pathways, the sulfur budget in a hydrothermal vent is poorly characterized due to the complexity of microbial sulfur cycling resulting from the numerous parties involved in the processes. In this study, we performed an int...

  7. Acetoanaerobium pronyense sp. nov., an anaerobic alkaliphilic bacterium isolated from a carbonate chimney of the Prony Hydrothermal Field (New Caledonia).

    Science.gov (United States)

    Bes, Méline; Merrouch, Mériem; Joseph, Manon; Quéméneur, Marianne; Payri, Claude; Pelletier, Bernard; Ollivier, Bernard; Fardeau, Marie-Laure; Erauso, Gaël; Postec, Anne

    2015-08-01

    A novel anaerobic bacterial strain, ST07-YET, was isolated from a carbonate chimney of the Prony Hydrothermal Field (PHF) in New Caledonia. Cells were Gram-stain-positive, straight rods (0.7-0.8 × 3.0-5.0 μm) and motile by means of lateral flagella. Strain ST07-YET was mesophilic (optimum 35 °C), moderately alkaliphilic and halotolerant (optimum pH 8.7 and 5 g l- 1 NaCl). Elemental sulfur, sulfate, thiosulfate, sulfite, nitrate and nitrite were not used as terminal electron acceptors. Yeast extract, peptone, tryptone, Casamino acids, crotonate, pyruvate, galactose, maltose, sucrose, ribose, trehalose and glucose were used as carbon sources. Glucose fermentation led to acetate, H2 and CO2 formation. Arginine, serine, histidine, lysine, methionine and cysteine improved growth, but the Stickland reaction was negative for the combinations of amino acids tested. The major metabolic products from yeast extract fermentation were H2, CO2, acetate, butyrate, isobutyrate, isovalerate and propionate. The predominant cellular fatty acids were C16  :  0, C16  :  1cis9, C14  :  0 and C16  :  1cis7 (>5 % of total fatty acids). The G+C content of the genomic DNA was 32.9 mol%. Phylogenetic analysis revealed that strain ST07-YET was most closely related to Clostridium sticklandii DSM 519T and Acetoanaerobium noterae NOT-3T (96.7 % and 96.8 % 16S rRNA gene sequence similarity, respectively). On the basis of phylogenetic, chemotaxonomic and physiological properties, strain ST07-YET is proposed to represent a novel species of the genus Acetoanaerobium (order Clostridiales, phylum Firmicutes) with the name Acetoanaerobium pronyense sp. nov. The type strain is ST07-YET ( = DSM 27512T = JCM 19400T). PMID:25948619

  8. Earthquakes increase hydrothermal venting and nutrient inputs into the Aegean

    Science.gov (United States)

    Dando, P. R.; Hughes, J. A.; Leahy, Y.; Taylor, L. J.; Zivanovic, S.

    1995-05-01

    Areas of submarine gas and water venting around the island of Milos, in the Hellenic volcanic island arc, were mapped. Water samples were collected from five stations in the geothermally active Paleohori Bay on 15 March 1992. Seismic events, of M s 5.0 and 4.4, occurred south of the Bay on 20 March and the sampling was repeated after these. Phosphate and manganese in the water column increased by 360% after the seismic activity. Analysis of water samples collected from gas and water seeps and of interstitial water from sediment cores showed that the hot sediment in the Bay was enriched in phosphate, to a mean concentration of 65 μmol l -1 in the interstitial water. The number of geothermally active areas in the Aegean, together with the extent of venting and the frequency of earthquakes suggests that the hydrothermal areas may be an important source of phosphate in this oligotrophic Sea.

  9. Hydrothermal vent flow and turbulence measurements with acoustic scintillation instrumentation

    Science.gov (United States)

    di Iorio, D.; Xu, G.

    2009-12-01

    Acoustically derived measurements of hydrothermal vent flow and turbulence were obtained from the active black smoker Dante in the Main Endeavour vent field, using scintillation analysis from one-way transmissions. The scintillation transmitter and receiver array formed a 93 m acoustic path through the buoyant plume 20 m above the structure. The acoustic path was parallel to the valley sidewall where the M2 tidal currents are approximately aligned along ridge due to topographic steering by the valley walls and hence most of the plume displacement is expected to occur along the acoustic path. On one deployment, data were collected for 6.5 weeks and vertical velocities range from 0.1 to 0.2 m/s showing a strong dependence on the spring/neap tidal cycle. The refractive index fluctuations which can be paramaterized in terms of the root-mean-square temperature fluctuations also shows a strong tidal modulation during spring tide.

  10. Free energy distribution and hydrothermal mineral precipitation in Hadean submarine alkaline vent systems: Importance of iron redox reactions under anoxic conditions

    Science.gov (United States)

    Shibuya, Takazo; Russell, Michael J.; Takai, Ken

    2016-02-01

    Thermodynamic calculations of mixing between hypothetical seawater and hydrothermal fluid in the Hadean deep ocean were carried out to predict saturation states of mineral precipitates and redox reactions that could occur in Hadean submarine alkaline hydrothermal systems associated with the serpentinization of ultramafic rocks. In the calculations, the seawater was assumed to be weakly acidic (pH = 5.5) and to include carbon dioxide, ferrous iron and silica, with or without nitrate, while the Hadean hydrothermal fluid was assumed to be highly alkaline (pH = 11) and to contain abundant molecular hydrogen, methane and bisulfide, based on the Archean geologic record, the modern low-temperature alkaline hydrothermal vent fluid (Lost City field), and experimental and theoretical considerations. The modeling indicates that potential mineral precipitates in the mixing zone (hydrothermal chimney structures) could consist mainly of iron sulfides but also of ferrous serpentine and brucite, siderite, and ferric iron-bearing minerals such as goethite, hematite and/or magnetite as minor phases. The precipitation of ferric iron-bearing minerals suggests that chemical iron oxidation would be made possible by pH shift even under anoxic condition. In the mixing zone, comprising an inorganic barrier precipitated at the interface of the two contrasting solutions, various redox reactions release free energy with the potential to drive endergonic reactions, assuming the involvement of coupling inorganic protoenzymes. Hydrogenotrophic methanogenesis and acetogenesis - long considered the most ancient forms of biological energy metabolisms - are able to achieve higher maximum energy yield (>0.5 kJ/kg hydrothermal fluid) than those in the modern serpentinization-associated seafloor hydrothermal systems (e.g., Kairei field). Furthermore, the recently proposed methanotrophic acetogenesis pathway was also thermodynamically investigated. It is known that methanotrophic acetogenesis would

  11. CFD simulation of vented explosion and turbulent flame propagation

    Directory of Open Access Journals (Sweden)

    Tulach Aleš

    2015-01-01

    Full Text Available Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.

  12. CFD simulation of vented explosion and turbulent flame propagation

    OpenAIRE

    Tulach Aleš; Mynarz Miroslav; Kozubková Milada

    2015-01-01

    Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments...

  13. CFD simulation of vented explosion and turbulent flame propagation

    Science.gov (United States)

    Tulach, Aleš; Mynarz, Miroslav; Kozubková, Milada

    2015-05-01

    Very rapid physical and chemical processes during the explosion require both quality and quantity of detection devices. CFD numerical simulations are suitable instruments for more detailed determination of explosion parameters. The paper deals with mathematical modelling of vented explosion and turbulent flame spread with use of ANSYS Fluent software. The paper is focused on verification of preciseness of calculations comparing calculated data with the results obtained in realised experiments in the explosion chamber.

  14. Regional Venting in the Manus Basin, New Britain Back Arc

    Science.gov (United States)

    Massoth, G. J.; Puzic, J.; Crowhurst, P.; White, M.; Nakamura, K.; Walker, S. L.; Baker, E. T.

    2008-12-01

    During June 2008 we conducted a systematic reconnaissance for hydrothermal venting along 1540 km of back-arc features located throughout the Manus back-arc basin. Our search was guided by high-resolution bathymetric and side scan back scatter data obtained during historical and immediately preceding geophysical surveys. Using real-time plume mapping protocols to discern anomalies in light scattering, temperature, and oxidation-reduction potential, we detected ~45 venting sites, ~34 of which are believed new. On average, the venting site density was about 3 sites per 100 km of back-arc feature, comparable to that for surveyed fast-spreading MORs in the eastern Pacific (3.2, Baker and German, AGU Geophysical Monograph 148, 2004) and about twice the global mean for MORs (1.6, Baker et al., JGR 2008). By virtue of being basin-scale, our assessment of venting into the Bismarck Sea revealed several mid-depth plumes that are widespread within the region. In the eastern Manus basin (Southeast Ridges, Djaul Transform, Southern Rifts, and Manus Spreading Center regions) the mean plume depth was 1825 m (range: 1080-2625 m), compared to generally more shallow discharge (mean plume depth 1155 m, range: 725-2080 m) in the western basin (Manus Extensional Transform and the Willaumez Transform and Ridge regions). While extreme anomaly intensities were observed in both the eastern and western portions of the Manus basin, most plumes were more characteristic of MOR and back arc plumes displaying a range of weak-to-moderate plume signals. Subsequent seafloor reconnaissance by ROV has located massive sulfides coincident to several plumes.

  15. TURBULENCE,VORTEX AND EXTERNAL EXPLOSION INDUCED BY VENTING

    Institute of Scientific and Technical Information of China (English)

    姜孝海; 范宝春; 叶经方

    2004-01-01

    The process of explosion venting to air in a cylindrical vent vessel connected to a duct, filling with a stoichiometric methane-oxygen gas mixture, was simulated numerically by using a colocated grid SIMPLE scheme based on k-epsilon turbulent model and Eddydissipation combustion model. The characteristics of the combustible cloud, flame and pressure distribution in the external flow field during venting were analyzed in terms of the predicted results. The results show that the external explosion is generated due to violent turbulent combustion in the high pressure region within the external combustible cloud ignited by a jet flame. And the turbulence and vortex in the external flow field were also discussed in detail. After the jet flame penetrating into the external combustible cloud, the turbulent intensity is greater in the regions with greater average kinetic energy gradient, rather than in the flame front; and the vortex in the external flow field is generated primarily due to the baroclinic effect, which is greater in the regions where the pressure and density gradients are nearly perpendicular.

  16. New digestive symbiosis in the hydrothermal vent amphipoda Ventiella sulfuris.

    Science.gov (United States)

    Corbari, Laure; Durand, Lucile; Cambon-Bonavita, Marie-Anne; Gaill, Françoise; Compère, Philippe

    2012-02-01

    Ventiella sulfuris Barnard and Ingram, 1990 is the most abundant amphipod species inhabiting the Eastern Pacific Rise (EPR 9°N) vent fields. This vent-endemic species is frequently encountered near colonies of Pompeii worms Alvinella pompejana. V. sulfuris specimens were collected during the oceanographic cruise LADDER II at the Bio9 (9°50.3'N, 2508m depth) hydrothermal vent site. Main objectives were to highlight the occurrence of bacterial symbiosis in V. sulfuris and to hypothesise their implications in nutrition. Observations in light and electron microscopy (SEM, TEM) showed that the outer body surface and appendages are free of microorganisms. In contrast, the digestive system revealed two major microbial communities settled in the midgut and in the hindgut. Gut contents showed bacterial traces together with abundant fragments of Alvinellid cuticle and setae, from A. pompejana, suggesting that V. sulfuris could directly feed on Alvinellids and/or on their bacterial epibionts. Molecular analyses based on the 16S rRNA genes revealed the diversity of bacterial communities in the digestive system, of which, the Epsilonproteobacteria phylum, could be considered as one of the major bacterial group. Hypotheses were proposed on their symbiotic features and their implications in V. sulfuris nutrition.

  17. CFD simulation of hydrogen deflagration in a vented room

    Science.gov (United States)

    Tolias, I. C.; Venetsanos, A. G.; Markatos, N. C.; Kiranoudis, C. T.

    2015-09-01

    In the present work, CFD simulations of hydrogen deflagration in a real scale vented room are performed. Two ignition points were simulated: at the wall opposite to the vent (back ignition) and at the center of the chamber (center ignition). The overpressure time series and flame front velocities are compared with the experimental results. The combustion model is based on the turbulent flame speed concept. The turbulent flame speed is calculated based on a modification of Yakhot's equation, in order to account for all the main physical mechanisms which appear in hydrogen deflagrations. Special attention is given to the simulation of Rayleigh-Taylor instability. This instability occurs at the vent area and results in sudden explosion of the mixture that has been pushed outside the chamber at the initial stage of the explosion. The importance of this external explosion to the generated overpressures inside the chamber is highlighted. The agreement between experimental and computational results is satisfactory in both back ignition and center ignition cases.

  18. Upstream petroleum industry flaring and venting report : industry performance for year ending December 31, 2005

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-10-15

    This report provided statistical data concerning solution gas flaring and venting in the upstream petroleum industry in Alberta. In their 2003 Upstream Petroleum Industry Flaring and Venting Report, the Alberta Energy and Utilities Board (EUB) made commitments to identify and implement a number of conservation measures aimed at reducing the volumes of solution gas vented from crude bitumen operations. As a result of the measures, venting from crude bitumen batteries decreased by 18.9 per cent in 2005. Solution gas conservation for 2005 was 96.3 per cent, the highest conservation level achieved to date. Solution gas flaring for 2005 was 71.9 per cent less than the 1996 baseline. A slight increase in solution gas flaring was attributed to crude bitumen operations. Solution gas venting for 2005 was 58.6 per cent less than the 2000 venting baseline. An analysis of the data suggested that significant progress has been made in reducing solution gas flaring in Alberta, and that venting reductions realized in 2005 continue the trend of significant reductions since 2000. Although the downward trend in the reduction of venting since 2000 is encouraging, the EUB continues to be concerned about solution gas venting associated with crude bitumen projects. It was concluded that the EUB will continue to work with all stakeholders to identify additional venting reduction strategies. 5 tabs., 3 figs.

  19. Geologic, geophysical, and in-situ stress investigations in the vicinity of the Dining Car chimney, Dining Car/Hybla Gold Drifts, Nevada Test Site

    International Nuclear Information System (INIS)

    The Hybla Gold event, detonated on Nov. 1, 1977, was conducted in the U12e.20 drifts of the E-tunnel complex beneath the surface of Rainier Mesa at the Nevada Test Site. Though the proximity of the Hybla Gold working point to the chimney of the Dining Car event was important to the experiment, the observable geologic effects from Dining Car on the Hybla Gold site were minor. Overburden above the working point is approximately 385 m (1263 ft). The pre-Tertiary surface, probably quartzite, lies approximately 254 m (833 ft) below the working point. This report comprises three chapters detailing the geologic, geophysical, and in situ stress data gathered in the period January through June 1977, in the course of mining and drilling in the Hybla Gold/Dining Car region. These investigations confirm several observations reported previously for the Rainier event, i.e., a zone of microfailure observable in thin-section and in physical properties exists adjacent to the chimney. In addition, however, a number of investigations add new information to our understanding of effects near the detonation point. Shear waves were found to be highly diagnostic in the microcracked zone near the chimney as well as zones of failure at greater range not discernible as well as zones of failure at greater range not discernible by other techniques. Extensive in situ stress measurements made by the hydrofracture and overcore techniques indicate changes in the orientation and magnitude of the pre-Dining Car stress field. The hydrofracture technique further suggests pronounced gradients in minimum stress magnitudes over short distances at some locations in the postshot stress regime

  20. A Tiled-Table Convention for Compressing FITS Binary Tables

    CERN Document Server

    Pence, William; White, Richard L

    2012-01-01

    This document describes a convention for compressing FITS binary tables that is modeled after the FITS tiled-image compression method (White et al. 2009) that has been in use for about a decade. The input table is first optionally subdivided into tiles, each containing an equal number of rows, then every column of data within each tile is compressed and stored as a variable-length array of bytes in the output FITS binary table. All the header keywords from the input table are copied to the header of the output table and remain uncompressed for efficient access. The output compressed table contains the same number and order of columns as in the input uncompressed binary table. There is one row in the output table corresponding to each tile of rows in the input table. In principle, each column of data can be compressed using a different algorithm that is optimized for the type of data within that column, however in the prototype implementation described here, the gzip algorithm is used to compress every column.

  1. Characterization of Alkaliphilus hydrothermalis sp nov., a novel alkaliphilic anaerobic bacterium, isolated from a carbonaceous chimney of the Prony hydrothermal field, New Caledonia

    OpenAIRE

    Ben Aissa, F.; Postec, A.; Erauso, G.; Payri, Claude; Pelletier, Bernard; Hamdi, M.; Fardeau, Marie-Laure; Ollivier, Bernard

    2015-01-01

    A novel anaerobic, alkaliphilic, Gram-positive staining bacterium was isolated from a hydrothermal chimney in the Prony Bay, New Caledonia. This strain designated FatMR1(T) grew at temperatures from 20 to 55 A degrees C (optimum 37 A degrees C) and at pH between 7.5 and 10.5 (optimum 8.8-9). NaCl is not required for growth (optimum 0.2-0.5 %), but is tolerated up to 3 %. Sulfate, thiosulfate, elemental sulfur, sulfite, nitrate and nitrite are not used as terminal electron acceptors. Strain Fa...

  2. Additional income with open chimneys and stove. Nostalgia, romanticism and thermal comfort; Zusatzgeschaeft mit Oefen und Kaminen. Nostalgisch-romantische Gefuehle und behagliche Waerme

    Energy Technology Data Exchange (ETDEWEB)

    Boehm, G. [Buderus Heiztechnik GmbH, Wetzlar (Germany)

    2004-01-01

    Stoves and open fireplaces are coming into fashion again with the trend towards nostalgia and design awareness. Further, wood-fuelled chimneys and stoves are viewed as romantic, and they also provide high thermal comfort. Heating systems experts can get additional income from this trend. (orig.) [German] Kamine und Oefen sind bei vielen Hausbesitzern und Bauherrn wieder in Mode. Dieser Trend ist zum einen Teil eines gestiegenen Nostalgie- und Designbewusstseins. Zum anderen gelten vor allem holzbefeuerte Kamine und Oefen als romantisch und ihre Waerme aufgrund des hohen Strahlungsanteils als behaglich. Fuer den aktiven Heizungsfachhandwerker laesst sich aus dieser Modestroemung ein lukratives Zusatzgeschaeft ableiten. (orig.)

  3. Euryhaline Halophilic Microorganisms From the Suiyo Seamount Hydrothermal Vents.

    Science.gov (United States)

    Okamoto, T.; Kimura, H.; Maruyama, A.; Naganuma, T.

    2002-12-01

    The euryhaline halophilic microorganisms grow in a wide salinity range from 15% NaCl or to even saturation (about 30% NaCl). A number of euryhaline halophiles have been found in a wide range of habitats from oceanic and terrestrial regimes, from deep-sea vents and seeps, and from Antarctic sea ice and terrains. We have isolated the euryhaline strains independently from a Mid-Atlantic Ridge vent fluids and Antarctic terrains are closely related species of the genus Halomonas. Some euryhaline halophiles maintain intracellular osmotic balance by controlling the concentration of compatible solute such as ectoine. This compatible solute not only stabilizes the proteins from denaturation caused by high salt concentration but also serves as a protectant against stresses such as heating, freezing and drying. The sub-seafloor structure of a hydrothermal vent is highly complicated with mosaic heterogeneity of physicochemical parameters such as temperature and salinity. This premise led us to the hypothesis that some euryhaline halophiles including Halomonas species well adapt to a wide salinity-ranged habitat in the sub-vent. To test this hypothesis, isolation and characterization of euryhaline halophiles from the Suiyo Seamount hydrothermal vents were conducted the drill-cored rock samples from the sites APSK-02, 03, and 07 and the filter-trapped fluid particle samples from the sites APSK-01 and 05 were used. For initial cultivation, a heterotrophic bacterial medium of 15% NaCl was used. The samples was added to the medium and incubated under both aerobic and anaerobic conditions at room temperature. A total of 5 euryhaline halophilic strains were obtained and phylogenetically characterized: two strains (both related to Marinobacter) from APSK-02 core section 2; one strain (related to H. meridiana) from APSK-07 core section 3; and two strains (related to H. meridiana and H. variabilis) from APSK-01 trapped particles. In addition, some thermophilic halophiles that grow at 20

  4. Behavioral filter vent blocking on the first cigarette of the day predicts which smokers of light cigarettes will increase smoke exposure from blocked vents.

    Science.gov (United States)

    Strasser, Andrew A; Tang, Kathy Z; Sanborn, Paul M; Zhou, Jon Y; Kozlowski, Lynn T

    2009-12-01

    Filter vent blocking on best-selling light cigarettes increases smoke yield during standard machine testing but not in clinical investigations of smokers. The purpose of the study was to investigate the effect of (a) manipulating cigarette filter vent blocking and (b) blocking status of first cigarette of the day on carbon monoxide (CO) boost. Participants (n = 25; Marlboro Lights nonmenthol cigarette smokers, age range 21-60 years, minimum 15 daily cigarettes, and daily smoking for a minimum 5 years) completed the laboratory-based, within-subject, double-blind, cross-over design of 2 smoking sessions, one utilizing a smoking topography device, one without. Each session consisted of smoking 4 cigarettes; 2 with filter vents blocked and 2 with filter vents unblocked. Spent first daily cigarette filters collected between sessions were scored for evidence of filter vent blocking. Smoking cigarettes with blocked filter vents significantly increased CO boost in both laboratory sessions (p < .001). Those who blocked their first cigarette of the day (n = 10) had significantly greater CO boost when smoking a blocked cigarette, in relation to smoking an unblocked cigarette and in comparison with nonblockers (p = .04). Total puff volume was a significant predictor of CO boost when smoking unblocked and blocked cigarettes (ps < .04). Blocking filter vents significantly increased smoke exposure in relation to when filter vents are not blocked, particularly for those who block filter vents on their first cigarette of the day. Total puff volume predicted CO boost, and results suggest that smokers adjust their smoking behavior by cigarette blocking status. Those smokers who block filter vents may be increasing their exposure by 30%. PMID:19968405

  5. How many vent fields? New estimates of vent field populations on ocean ridges from precise mapping of hydrothermal discharge locations

    Science.gov (United States)

    Baker, Edward T.; Resing, Joseph A.; Haymon, Rachel M.; Tunnicliffe, Verena; Lavelle, J. William; Martinez, Fernando; Ferrini, Vicki; Walker, Sharon L.; Nakamura, Koichi

    2016-09-01

    Decades of exploration for venting sites along spreading ridge crests have produced global datasets that yield estimated mean site spacings of ∼ 12- 220 km. This conclusion demands that sites where hydrothermal fluid leaks from the seafloor are improbably rare along the 66 000 km global ridge system, despite the high bulk permeability of ridge crest axes. However, to date, exploration methods have neither reliably detected plumes from isolated low-temperature, particle-poor, diffuse sources, nor differentiated individual, closely spaced (clustered within a few kilometers) sites of any kind. Here we describe a much lower mean discharge spacing of 3-20 km, revealed by towing real-time oxidation-reduction-potential and optical sensors continuously along four fast- and intermediate-rate (>55 mm/yr) spreading ridge sections totaling 1470 km length. This closer spacing reflects both discovery of isolated sites discharging particle-poor plumes (25% of all sites) and improved discrimination (at a spatial resolution of ∼1 km) among clustered discrete and diffuse sources. Consequently, the number of active vent sites on fast- and intermediate-rate spreading ridges may be at least a factor of 3-6 higher than now presumed. This increase provides new quantitative constraints for models of seafloor processes such as dispersal of fauna among seafloor and crustal chemosynthetic habitats, biogeochemical impacts of diffuse venting, and spatial patterns of hydrothermal discharge.

  6. Microbial Response to High Temperature Hydrothermal Forcing: AISICS Vent (Lucky Strike, 37°N, MAR) and Prokaryote Community as Example.

    Science.gov (United States)

    Henri, P. A.; Rommevaux, C.; Chavagnac, V.; Degboe, J.; Destrigneville, C.; Boulart, C.; Lesongeur, F.; Castillo, A.; Goodfroy, A.

    2015-12-01

    To study the hydrothermal forcing on microbial colonization, and impacts on the oceanic crust alteration, an integrated study was led at the Tour Eiffel hydrothermal site (Lucky Strike hydrothermal field, 37°N, MAR). We benefited from an annual survey between 2009 and 2011 of temperatures, along with sampling of focused and diffused fluids for chemical analysis, and chimney sampling and samples from microbial colonization experiments analyzed for prokaryotic composition and rock alteration study. The chemical composition of the fluids show an important increase in the CO2 concentration at the Eiffel Tower site between 2009 and 2010 followed by a decrease between 2010 and 2011. In 2011, several fluid samples show an important depletion in Si, suggesting that some Si was removed by interaction with the stockwork before emission. Our observations, regarding the previous studies of chemical fluid affected by a magmatic event lead us to suppose that a magmatic/tectonic event occurred under the Lucky Strike hydrothermal field between 2009 and 2010. The results of the prokaryotic communities' analysis show that a shift occurred in the dominant microbial metabolisms present in the colonizer retrieved in 2010 and the one retrieved in 2011. Archaeal communities shifted from chemolithoautotropic sulfite/thiosulfate reducers-dominated in 2010 to ammonia oxidizers-dominated in 2011. The bacterial communities also undergo a shift, from a community with diversified metabolisms in 2010 to a community strongly dominated by chemolithoautotrophic sulfide or hydrogen oxidation in 2011. Moreover, in terms of ecological preferendum, the Archaeal communities shifted from thermophilic-dominated to mesophilic-dominated. The present study underline the influence of modifications in gases compositions of hydrothermal fluids subsequently to a degassing of the magma chamber and their impact on the microbial communities living in the vicinity of hydrothermal vents at the Eiffel Tower site.

  7. Upstream petroleum industry flaring and venting report : Industry performance for year ending December 31, 2004

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-08-01

    Since 1938, the Alberta Energy and Utilities Board (EUB) has made the reduction of routine flaring and venting of solution gas a priority. The EUB has been acknowledged internationally for its achievements in reducing flaring and venting. The EUB's goal is to eliminate the routine flaring and venting of solution gas in order to address energy conservation and public safety. This report describes how the EUB fulfills its information mandate regarding flaring and venting. It is published in response to a commitment made by the EUB to make flaring and venting data more accessible. The EUB and the Clean Air Strategic Alliance have established baselines for flaring and venting. Regulations, enforcement and industry cooperation have resulted in major reductions in the amount of solution gas flared and vented. This report provides a summary of flared and vented volumes for the different oil and gas industry sources, such as well tests, gas plants, gas gathering systems, transmission lines, and batteries. It also contains detailed information on solution gas conserved, flared, and vented during 2003. Ranking of companies was established based on solution gas flared plus vented, solution gas flared, and solution gas vented, from crude oil and bitumen batteries. The data used in the preparation of this report was submitted by companies. The data demonstrates that considerable progress has been made in the reduction of flaring and venting volumes for all upstream oil and gas sources. Solution gas conservation for 2004 was 96.0 per cent, the highest conservation level achieved to date. Solution gas flaring for 2004 was 72.2 per cent less than the 1996 flaring baseline, compared to 70.0 per cent less than the baseline in 2003. tabs., figs.

  8. Upstream petroleum industry flaring and venting report : Industry performance for year ending December 31, 2003

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-05-01

    Solution gas is the largest source of flaring and venting in Alberta. The Alberta Energy and Utilities Board (EUB) has been acknowledged internationally for its success in reducing flaring and venting. The EUB's target is to eliminate the routine flaring and venting of solution gas to address conservation and public safety. This report describes how the EUB fulfills its information mandate regarding flaring and venting. It is published in response to a commitment made by the EUB to make flaring and venting data more accessible. The EUB and the Clean Air Strategic Alliance have established baselines for flaring and venting. Regulations, enforcement and industry cooperation have resulted in major reductions in the amount of solution gas flared and vented. This report provides a summary of flared and vented volumes for the different oil and gas industry sources, such as well tests, gas plants, gas gathering systems, transmission lines, and batteries. It also contains detailed information on solution gas conserved, flared, and vented during 2003. Ranking of companies was established based on solution gas flared plus vented, solution gas flared, and solution gas vented, from crude oil and bitumen batteries. The data used in the preparation of this report was submitted by companies. The data demonstrates that considerable progress has been made in the reduction of flaring and venting volumes for all upstream oil and gas sources. Solution gas conservation for 2003 was 95.4 per cent, the highest conservation level achieved to date. Solution gas flaring for 2003 was 70 per cent less than the 1996 flaring baseline. tabs., figs.

  9. Vacuolate-attached filaments: highly productive Ridgeia piscesae epibionts at the Juan de Fuca hydrothermal vents

    OpenAIRE

    Kalanetra, Karen M.; Nelson, Douglas C.

    2010-01-01

    Vacuolate sulfur bacteria with high morphological similarity to vacuolate-attached filaments previously described from shallow hydrothermal vents (White Point, CA) were found at deep-sea hydrothermal vents. These filamentous bacteria grow in dense mats that cover surfaces and potentially provide a significant source of organic carbon where they occur. Vacuolate-attached filaments were collected near vents at the Clam Bed site of the Endeavour Segment of the Juan de Fuca Ridge and from the sed...

  10. Hybrid Solar Chimney and Evaporative Cooling System Used in Xinjiang%新疆地区太阳能烟囱复合蒸发冷却通风降温系统

    Institute of Scientific and Technical Information of China (English)

    宣永梅; 马柱柱; 黄翔

    2013-01-01

    提出了太阳能烟囱复合蒸发冷却系统,对复合系统模型进行了理论分析及计算,得出通风量与烟囱高度、宽度及太阳辐射强度之间的关系。结果表明,太阳能烟囱的自然通风量随太阳能辐射强度及烟囱高度的增加而增加;在计算条件下,当宽度取1m 时通风量取得最大值。在此基础上分析得到太阳辐射照度400W/m2、烟囱高度3m、宽度1m 时,太阳能烟囱复合蒸发冷却系统应用于乌鲁木齐建筑时烟囱的理论通风量为0.21kg/s,该通风量基本满足乌鲁木齐夏季通风设计工况下,蒸发冷却降温时所需动力(0.23kg/s),且室内通风换气次数达到10次/h 以上,是一种节能环保的自然通风降温技术。%A hybrid system of solar chimney and evaporative cooling was proposed.The model of this hybrid system was studied by theoritical analysis and calculation.The relationships between air flow rate with chimney height,width and solar radiation were obtained.The calculation results indicated that the air flow rate of solar chimney increases with solar radiation and chimney height.Under design conditions,the air flow rate of solar chimney reaches its maximum value at solar chimney width of 1m. When applied to actual buildings in Urumqi,the obtained air mass flow rate (0.21kg/s)of solar chimney under optimum condi-tions (at chimney height of 3m,width of 1m,solar radiation of 400W/m2 )can approximately meet the ventilation requirements of evaporative cooling (0.23kg/s),and air changes more than 10 times per hour.The proposed hybrid system is an environmental friendly and energy efficient natural ventilation and free cooling technology.

  11. Functional and hierarchical interactions among zebrafish vox/vent homeobox genes.

    Science.gov (United States)

    Gilardelli, Claudio N; Pozzoli, Ombretta; Sordino, Paolo; Matassi, Giorgio; Cotelli, Franco

    2004-07-01

    The vertebrate Vox/Vent family of transcription factors plays a crucial role in the establishment of the dorsoventral (DV) axis, by repressing organizer genes such as bozozok/dharma, goosecoid, and chordino. In Danio rerio (zebrafish), members of the vox/vent gene family (vox/vega1, vent/vega2, and ved) are thought to share expression patterns and functional properties. Bringing novel insights in the differential activity of the zebrafish vox/vent genes, we propose a critical role for the ved gene in DV patterning of vertebrate embryos. ved is not only expressed as a maternal gene, but it also appears to function as a repressor of dorsal factors involved in organizer formation. At early- and mid-gastrula stage, ved appears to be finely controlled by antagonist crosstalks in a complex regulatory network, involving gradients of bone morphogenetic protein (BMP) activity, dorsal factors, and vox/vent family members. We show that ved transcripts are ventrally restricted by BMP factors such as bmp2b, bmp7, smad5, and alk8, and by dorsal factors (chd and gsc). Alteration of ved expression in both vox and vent deletion mutants and vox and vent mRNAs-injected embryos, suggests that vox and vent function downstream of BMP signaling to negatively regulate ved expression. This inhibitory role is emphasized by a vox and vent redundant activity, compared with single gene effects. PMID:15188434

  12. Functional and hierarchical interactions among zebrafish vox/vent homeobox genes.

    Science.gov (United States)

    Gilardelli, Claudio N; Pozzoli, Ombretta; Sordino, Paolo; Matassi, Giorgio; Cotelli, Franco

    2004-07-01

    The vertebrate Vox/Vent family of transcription factors plays a crucial role in the establishment of the dorsoventral (DV) axis, by repressing organizer genes such as bozozok/dharma, goosecoid, and chordino. In Danio rerio (zebrafish), members of the vox/vent gene family (vox/vega1, vent/vega2, and ved) are thought to share expression patterns and functional properties. Bringing novel insights in the differential activity of the zebrafish vox/vent genes, we propose a critical role for the ved gene in DV patterning of vertebrate embryos. ved is not only expressed as a maternal gene, but it also appears to function as a repressor of dorsal factors involved in organizer formation. At early- and mid-gastrula stage, ved appears to be finely controlled by antagonist crosstalks in a complex regulatory network, involving gradients of bone morphogenetic protein (BMP) activity, dorsal factors, and vox/vent family members. We show that ved transcripts are ventrally restricted by BMP factors such as bmp2b, bmp7, smad5, and alk8, and by dorsal factors (chd and gsc). Alteration of ved expression in both vox and vent deletion mutants and vox and vent mRNAs-injected embryos, suggests that vox and vent function downstream of BMP signaling to negatively regulate ved expression. This inhibitory role is emphasized by a vox and vent redundant activity, compared with single gene effects.

  13. Brief Communication: The effect of submerged vents on probabilistic hazard assessment for tephra fallout

    Directory of Open Access Journals (Sweden)

    R. Tonini

    2014-11-01

    Full Text Available Many volcanic systems are partially or entirely submerged, implying that vents may open underwater. The effect of submerged vents on probabilistic volcanic hazard assessment (PVHA for tephra fallout has always been neglected, introducing potentially uncontrolled biases. We present a strategy to quantify the effect of submerged vents on PVHA for tephra fallout, based on a simplified empirical model where the efficiency of tephra production decreases as a function of the water depth above the eruptive vent. The method is then applied to Campi Flegrei caldera, comparing its results to those of two reference end-member models and their statistical mixing.

  14. Upstream petroleum industry flaring and venting report : Industry performance for year ending December 31, 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-09-01

    The largest source of flaring and venting in Alberta is solution gas, accounting for 66 per cent of total emissions in 2002. A summary of flared and vented volumes for the different oil and gas industry sources, such as well tests, gas plants, gas gathering systems, transmission lines, and batteries was presented in this report. It also contained detailed information on solution gas conserved, flared, and vented during 2002. Rankings of companies was established based on solution gas flared plus vented, solution gas flared, and solution gas vented, from crude oil and bitumen batteries. The ranking is provincial and also by the Energy Utilities Board (EUB) Field Centre area. The data used in the preparation of this report is submitted by companies. Considerable progress was made in the reduction of flaring and venting volumes for all upstream oil and gas sources, as demonstrated by the data. A reduction of 62 per cent from the 1996 flaring baseline was achieved. A reduction of 29 per cent was achieved for the venting of solution gas from the 2000 venting baseline. There was a 44 per cent reduction in the volume of solution gas flared and vented from the 1996 volume. tabs., figs.

  15. Pressure suppression pool hydrodynamic studies for horizontal vent exit of Indian PHWR containment

    International Nuclear Information System (INIS)

    The standard Indian PHWR incorporates a pressure suppression type of containment system with a suppression pool.The design of KAPS (Kakrapar Atomic Power Station) suppression pool system adopts a modified system of downcomers having horizontal vents as compared to vertical vents of NAPS (Narora Atomic Power Station). Hydrodynamic studies for vertical vents have been reported earlier. This paper presents hydrodynamic studies for horizontal type vent system during LOCA. These studies include the phenomenon of vent clearing (where the water slug standing in downcomer initially is injected to wetwell due to rapid pressurization of drywell) followed by pool swell (elevation of pool water due to formation of bubbles due to air mass entering pool at the exit of horizontal vents from drywell). The analysis performed for vent clearing and pool swell is based on rigorous thermal hydraulic calculation consisting of conservation of air-steam mixture mass, momentum and thermal energy and mass of air. Horizontal vent of downcomer is modelled in such a way that during steam-air flow, variation of flow area due to oscillating water surface in downcomer could be considered. Calculation predicts that the vent gets cleared in about 1.0 second and the corresponding downward slug velocity in the downcomer is 4.61 m/sec. The maximum pool swell for a conservative lateral expansion is calculated to be 0.56 m. (author). 3 refs., 12 figs

  16. Hydrothermal vent fields and chemosynthetic biota on the world's deepest seafloor spreading centre.

    Science.gov (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

    2012-01-01

    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

  17. Treating patients with abdominal aortic aneurysm with endovascular repair and the crossover chimney technique in the internal iliac artery to protect the unilateral internal iliac artery

    Science.gov (United States)

    Guo, Xi; Li, Peng; Liu, Guang-Rui; Huang, Xiao-Yong; Huang, Lian-Jun

    2015-01-01

    This study aims to explore the treatment methods for patients with abdominal aortic aneurysms (AAAs) that required occlusion of the openings of the bilateral internal iliac arteries (IIAs) in endovascular aneurysm repair (EVAR) and to evaluate the efficacy of these treatments. Four patients with AAA were treated with endovascular aneurysm repair (EVAR) and the crossover chimney technique in the bilateral internal iliac arteries (IIAs). We inserted and released the abdominal aortic stent as usual and implanted the bypass stent graft simultaneously. The intraoperative immediate angiography showed complete isolation of the AAA and patency of the bypass. One month after surgery, it showed contrast engorgement in the bypass stent in three patients. The IIA on the bypass side and its branches had good developing. Another case in which we utilized a COOK stent, occlusion started at the opening of the bypass stent, with no occurrence of other complications. For patients in whom AAAs involve bilateral iliac arteries and the openings of the bilateral IIAs need to be occluded, EVAR and a crossover chimney technique can protect the unilateral IIA. PMID:26885136

  18. Enhanced bilateral somatostatin receptor expression in mediastinal lymph nodes (''chimney sign'') in occult metastatic medullary thyroid cancer: a typical site of tumour manifestation?

    International Nuclear Information System (INIS)

    In medullary thyroid cancer (MTC), post-surgically elevated plasma calcitonin and/or carcinoembryonic antigen levels frequently indicate persisting metastatic disease, although conventional diagnostic procedures fail to localize the responsible lesions (occult disease). Somatostatin analogues have been used successfully in disease localization, but recently concerns have been raised that increased thoracic uptake of indium-111 pentetreotide in patients with previous external beam irradiation may represent a false-positive finding, caused by post-irradiation pulmonary fibrosis. We recently examined seven patients with metastatic MTC by somatostatin receptor scintigraphy (six with occult and one with established disease). In four patients, all of whom had stable or slowly rising tumour marker levels over several years, a chimney-like bilateral mediastinal uptake of indium-111 pentetreotide was found. In two patients with persisting hypercalcitonaemia immediately after primary surgery, supraclavicular lymph node metastases were identified as the responsible lesions. None of these seven patients had prior external beam radiation therapy. In two cases, histological confirmation was obtained. In one patient, disease progression could be shown during follow-up. These data suggest that bilateral mediastinal lymph node involvement is a typical site of disease in slowly progressing occult metastatic MTC; the ''chimney sign'' may represent a typical finding with somatostatin analogues in such cases. Therefore, we believe that even in the case of prior external beam irradiation, mediastinal uptake of octreotide might represent metastatic MTC rather than radiation fibrosis. (orig.). With 2 figs., 1 tab

  19. Research on Design Technique of FRP-liners of Wet Chimney%湿烟囱玻璃钢内简结构设计技术研究

    Institute of Scientific and Technical Information of China (English)

    杨小兵; 田树桐; 阮明山; 马申

    2011-01-01

    The wet chimney with high-performance FRP( Fiberglass Reinforced Plastic) liners is effective scheme to solve the corrosion problem, however, the design technique need to be improved by virtue of less study and practice.In this paper, through analysis and calculation, such topics as failure mode of FRP material, safety factors and supporting style of liners was studied exhaustively on base of the service conditions of wet chimney and the design standards home and abroad. Then reasonable suggestions were pointed out. It can be referred for engineers in design and construction .%采用高性能玻璃钢内筒是解决环保燃煤电厂湿烟囱腐蚀问题的有效途径,但目前国内对玻璃钢烟囱结构设计研究较少,有关技术问题亟待解决.文章基于国内外玻璃钢结构设计规范和湿烟囱的使用条件,通过分析计算,对玻璃钢烟囱结构设计中材料失效模式、安全系数取值、内筒支承方式等技术问题进行了深入探讨,提出了合理的建议,可供有关工程技术人员参考.

  20. On isomorphisms of integral table algebras

    Institute of Scientific and Technical Information of China (English)

    FAN; Yun(樊恽); SUN; Daying(孙大英)

    2002-01-01

    For integral table algebras with integral table basis T, we can consider integral R-algebra RT over a subring R of the ring of the algebraic integers. It is proved that an R-algebra isomorphism between two integral table algebras must be an integral table algebra isomorphism if it is compatible with the so-called normalizings of the integral table algebras.

  1. Analysis on the optimization geometry of the solar chimney power plant systems%太阳能热气流发电流道优化分析

    Institute of Scientific and Technical Information of China (English)

    职更辰; 陈威

    2013-01-01

    以西班牙太阳能热气流电站为原型进行数值模拟,得出了太阳能烟囱内的速度场、压力场和温度场分布;研究了集热棚坡度、分流板高度和弧度等因素对系统发电性能及涡轮机位置的影响.研究结果表明:集热棚坡度增加时,烟囱的抽吸作用增强,空气流速增加,有利于提高太阳能热气流发电的输出功率;当集热棚坡度约为0.5°时,其作用最为明显,对于提高系统发电性能最为有利;增加分流板有利于气流发电站的优化,当分流板高度略微高于集热棚高度时,优化效果较好;分流板弧度越小,越有利于系统的优化;集热棚坡度对涡轮机位置有影响,改变分流板的几何因素对涡轮机位置没有影响.%An Spanish solar chimney power plant was considered as a prototype to establish a numerical simulation in this paper, and the distribution of velocity, pressure and temperature fields in the solar chimney were derived; Thereby the impact of changing of geometric factors, which included the slope of the collector shed, the height and radians of the shunt board and so on, on the system power performance and the location of turbine were studied. Research results showed that, as the slope of the collector shed beginning to increase, the drawing action of the chimney increased and the velocity of air enhanced, which would help to improve the generator output of solar chimney; When the collector shed gradient increased to about 0.5 degrees, the strengthening of chimney drawing was the most obvious, which was the most advantageous for improving the system's power generation performance; The airflow power station performed better while increasing the number of manifold; When the manifold height was slightly higher than that of the collector shed, the system performed well; The slighter the curvature of manifold, the better the system presented. The slope of the collector shed affects location of the turbine, but the turbine

  2. The Origin of Life in Alkaline Hydrothermal Vents.

    Science.gov (United States)

    Sojo, Victor; Herschy, Barry; Whicher, Alexandra; Camprubí, Eloi; Lane, Nick

    2016-02-01

    Over the last 70 years, prebiotic chemists have been very successful in synthesizing the molecules of life, from amino acids to nucleotides. Yet there is strikingly little resemblance between much of this chemistry and the metabolic pathways of cells, in terms of substrates, catalysts, and synthetic pathways. In contrast, alkaline hydrothermal vents offer conditions similar to those harnessed by modern autotrophs, but there has been limited experimental evidence that such conditions could drive prebiotic chemistry. In the Hadean, in the absence of oxygen, alkaline vents are proposed to have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with relatively acidic ocean waters rich in CO2, through a labyrinth of interconnected micropores with thin inorganic walls containing catalytic Fe(Ni)S minerals. The difference in pH across these thin barriers produced natural proton gradients with equivalent magnitude and polarity to the proton-motive force required for carbon fixation in extant bacteria and archaea. How such gradients could have powered carbon reduction or energy flux before the advent of organic protocells with genes and proteins is unknown. Work over the last decade suggests several possible hypotheses that are currently being tested in laboratory experiments, field observations, and phylogenetic reconstructions of ancestral metabolism. We analyze the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria to propose a possible ancestral mechanism of CO2 reduction in alkaline hydrothermal vents. Based on this mechanism, we show that the evolution of active ion pumping could have driven the deep divergence of bacteria and archaea.

  3. The Origin of Life in Alkaline Hydrothermal Vents.

    Science.gov (United States)

    Sojo, Victor; Herschy, Barry; Whicher, Alexandra; Camprubí, Eloi; Lane, Nick

    2016-02-01

    Over the last 70 years, prebiotic chemists have been very successful in synthesizing the molecules of life, from amino acids to nucleotides. Yet there is strikingly little resemblance between much of this chemistry and the metabolic pathways of cells, in terms of substrates, catalysts, and synthetic pathways. In contrast, alkaline hydrothermal vents offer conditions similar to those harnessed by modern autotrophs, but there has been limited experimental evidence that such conditions could drive prebiotic chemistry. In the Hadean, in the absence of oxygen, alkaline vents are proposed to have acted as electrochemical flow reactors, in which alkaline fluids saturated in H2 mixed with relatively acidic ocean waters rich in CO2, through a labyrinth of interconnected micropores with thin inorganic walls containing catalytic Fe(Ni)S minerals. The difference in pH across these thin barriers produced natural proton gradients with equivalent magnitude and polarity to the proton-motive force required for carbon fixation in extant bacteria and archaea. How such gradients could have powered carbon reduction or energy flux before the advent of organic protocells with genes and proteins is unknown. Work over the last decade suggests several possible hypotheses that are currently being tested in laboratory experiments, field observations, and phylogenetic reconstructions of ancestral metabolism. We analyze the perplexing differences in carbon and energy metabolism in methanogenic archaea and acetogenic bacteria to propose a possible ancestral mechanism of CO2 reduction in alkaline hydrothermal vents. Based on this mechanism, we show that the evolution of active ion pumping could have driven the deep divergence of bacteria and archaea. PMID:26841066

  4. Drainage vent systems: investigation and analysis of air pressure regime

    Energy Technology Data Exchange (ETDEWEB)

    Swaffield, J.A.; Jack, L.B. [Heriot-Watt University, Edinburgh (United Kingdom). Dept. of Building Engineering and Surveying

    1998-12-31

    Knowledge of the performance of building drainage vent systems and associated appliance trap seal loss and retention has developed in recent years due to extensive research into the generation and propagation of air pressure transients within drainage networks. This paper demonstrates how data gathered from experimental testing of several single stack systems, considering the influence of a wide range of parameters including stack diameter, roughness, height and applied water flow rate, can be used to provide generally applicable mathematical expressions which assist in determining the pressure regime present at critical points within such systems. (author)

  5. Let Us Make the Table Periodic.

    Science.gov (United States)

    Campbell, J. Arthur

    1989-01-01

    An approach to teaching the properties of the elements and their arrangement in the periodic table is suggested. Discussed are symbols for the elements, format of the table, and coding the properties of the elements on the table. (CW)

  6. Table1_GADP_NOSSmoothSheets.csv

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This comma-separated value (.csv) table, "Table1_GADP_NOSSmoothSheets.csv," is a derivative table of the information in shapefile "GADP_NOSSeafloorCharacter.zip"...

  7. The homeobox genes vox and vent are redundant repressors of dorsal fates in zebrafish.

    Science.gov (United States)

    Imai, Y; Gates, M A; Melby, A E; Kimelman, D; Schier, A F; Talbot, W S

    2001-06-01

    Ventralizing transcriptional repressors in the Vox/Vent family have been proposed to be important regulators of dorsoventral patterning in the early embryo. While the zebrafish genes vox (vega1) and vent (vega2) both have ventralizing activity in overexpression assays, loss-of-function studies are needed to determine whether these genes have distinct or redundant functions in dorsoventral patterning and to provide critical tests of the proposed regulatory interactions among vox, vent and other genes that act to establish the dorsoventral axis. We show that vox and vent are redundant repressors of dorsal fates in zebrafish. Mutants that lack vox function have little or no dorsoventral patterning defect, and inactivation of either vox or vent by injection of antisense morpholino oligonucleotides has little or no effect on the embryo. In contrast, embryos that lack both vox and vent function have a dorsalized phenotype. Expression of dorsal mesodermal genes, including chordin, goosecoid and bozozok, is strongly expanded in embryos that lack vox and vent function, indicating that the redundant action of vox and vent is required to restrict dorsal genes to their appropriate territories. Our genetic analysis indicates that the dorsalizing transcription factor Bozozok promotes dorsal fates indirectly, by antagonizing the expression of vox and vent. In turn, vox and vent repress chordin expression, restricting its function as an antagonist of ventral fates to the dorsal side of the embryo. Our results support a model in which BMP signaling induces the expression of ventral genes, while vox and vent act redundantly to prevent the expression of chordin, goosecoid and other dorsal genes in the lateral and ventral mesendoderm. PMID:11493559

  8. MCNPX Model/Table Comparison

    CERN Document Server

    Hendricks, J S

    2003-01-01

    MCNPX is a Monte Carlo N-Particle radiation transport code extending the capabilities of MCNP4C. As with MCNP, MCNPX uses nuclear data tables to transport neutrons, photons, and electrons. Unlike MCNP, MCNPX also uses (1) nuclear data tables to transport protons; (2) physics models to transport 30 additional particle types (deuterons, tritons, alphas, pions, muons, etc.); and (3) physics models to transport neutrons and protons when no tabular data are available or when the data are above the energy range (20 to 150 MeV) where the data tables end. MCNPX can mix and match data tables and physics models throughout a problem. For example, MCNPX can model neutron transport in a bismuth germinate (BGO) particle detector by using data tables for bismuth and oxygen and using physics models for germanium. Also, MCNPX can model neutron transport in UO sub 2 , making the best use of physics models and data tables: below 20 MeV, data tables are used; above 150 MeV, physics models are used; between 20 and 150 MeV, data t...

  9. 太阳能烟囱强化自然通风的研究现状%Research Status on Solar Chimney for Natural Ventilation Enhancement

    Institute of Scientific and Technical Information of China (English)

    苏亚欣; 柳仲宝

    2011-01-01

    Natural ventilation is an energy efficient passive cooling technology and it uses wind or thermal buoyancy to deliver fresh air into the buildings in order to maintain a good indoor air quality. Comparing with mechanical ventilation, natural ventilation has obvious energy-saving advantages. Solar Chimney (SC) is a vertical or inclined channel that utilizes solar radiation to cause a temperature rise and density drop for the air flowing through the chimney, therefore enhances the natural ventilation. First, two types of typical solar chimney, namely, Trombe wall-type and inclined roof-type solar chimney, and their basic principle to enhance natural ventilation are briefly introduced. Then, the parameters that influence the performance of natural ventilation of the solar chimney are discussed in detail. The major methods and result are listed based on the review of the research works on solar chimney by different authors. The height and depth (the distance between the glass cover and absorber wall) of SC influence the natural convection flow process and the temperature rise of air in the SC channel and furthermore influence the ventilation rate of the SC strongly. The ventilation air I.e. The air flow rate increases with the increase of SC depth. The air flow rate decreases when the SC depth exceeds an optimal value. A reverse flow appears near the top of the SC channel when the ratio of SC depth to height is larger than 2.5 and the increase of natural ventilation rate is limited. The effect of the SC structure and its inclined angle on ventilation is related to the geographical location and climate conditions. The modeling of SC ventilation includes the mathematical modeling that is based on the energy conservation analysis on the heat transfer process of the air on the wall surfaces and the numerical simulation of the flow process that is based on Computational Fluid Dynamics (CFD) method. Based on the literature review, the issues that need to be improved in solar

  10. The Periodic Table in Croatia

    Directory of Open Access Journals (Sweden)

    Raos, N.

    2011-12-01

    Full Text Available The Croatian (Yugoslav Academy of Sciences and Arts was the first academy to elect D. I. Mendeleev as its honorary member (1882, whereas the periodic table of the elements has been taught regularly at the Zagreb University since 1888. The early interest of Croatian chemists in the periodic table should be attributed primarily to their pan-Slavic attitude, particularly as proof that Slavic people were able to produce "their own Newtons" (M. V. Lomonosov and D. I. Mendeleev. Such enthusiastic views, however, did not help in analyzing the contribution of Mendeleev and other scientists to the discovery and development of the periodic table of the elements.

  11. The effect of internals vent valves on reflood following a hypothetical PWR LOCA

    International Nuclear Information System (INIS)

    This paper presents an analysis of the effect of internals vent valves in alleviating the potential for core steam binding and reducing the conventional loss coefficient for the venting pipework during reflood following a hypothetical PWE LOCA. The RAP code was used to construct response surfaces for the time to quench at six-foot elevation for systems with and without the valves. (author)

  12. 40 CFR 63.114 - Process vent provisions-monitoring requirements.

    Science.gov (United States)

    2010-07-01

    ... accurately. Monitoring is not required for process vents with TRE index values greater than 4.0 as specified...) Maintains a TRE greater than 1.0 but less than or equal to 4.0 without a recovery device or with a recovery... Manufacturing Industry for Process Vents, Storage Vessels, Transfer Operations, and Wastewater § 63.114...

  13. 缸体铸件的排气方法%Venting Method of Cylinder Block Casting

    Institute of Scientific and Technical Information of China (English)

    王公昱; 惠彦芳; 侯润平

    2012-01-01

    Several venting methods used for cylinder block casting were introduced. The design principle of the venting system used for the cylinder block was pointed out as that the gas of mould cavity and the gas of the cores should be vented separately; the vents setting directly on the casting surface should be avoided as possible; Venting locations should be rationally distributed; Setting venting filters on those locations where venting is necessary but no boss existing is a economic and effective venting method; Controlling permeability of the core sand of the water jacket core could prevent the blowhole caused due to the gas evolution of the jacket core.%介绍了缸体铸件的几种排气方法.指出:设计排气系统时,应以型腔气体与砂芯气体分开排出为原则,要尽量避免在缸体铸件本体直接排气;要合理布局排气部位,在必须排气而无凸台的部位放置排气过滤片,是经济有效的排气方法;控制水套砂芯的透气性可以预防因其发气引起的气孔缺陷.

  14. Living with the Heat. Submarine Ring of Fire--Grades 5-6. Hydrothermal Vent Ecology.

    Science.gov (United States)

    National Oceanic and Atmospheric Administration (DOC), Rockville, MD.

    This activity is designed to teach about hydrothermal vent ecology. Students are expected to describe how hydrothermal vents are formed and characterize the physical conditions at these sites, explain chemosynthesis and contrast this process with photosynthesis, identify autotrophic bacteria as the basis for food webs in hydrothermal vent…

  15. 40 CFR 270.24 - Specific part B information requirements for process vents.

    Science.gov (United States)

    2010-07-01

    ... cannot install a closed-vent system and control device to comply with the provisions of 40 CFR 264 subpart AA on the effective date that the facility becomes subject to the provisions of 40 CFR 264 or 265... requirements for process vents. 270.24 Section 270.24 Protection of Environment ENVIRONMENTAL PROTECTION...

  16. Spatial and Alignment Analyses for a field of Small Volcanic Vents South of Pavonis Mons Mars

    Science.gov (United States)

    Bleacher, J. E.; Glaze, L. S.; Greeley, R.; Hauber, E.; Baloga, S. M.; Sakimoto, S. E. H.; Williams, D. A.; Glotch, T. D.

    2008-01-01

    The Tharsis province of Mars displays a variety of small volcanic vent (10s krn in diameter) morphologies. These features were identified in Mariner and Viking images [1-4], and Mars Orbiter Laser Altimeter (MOLA) data show them to be more abundant than originally observed [5,6]. Recent studies are classifying their diverse morphologies [7-9]. Building on this work, we are mapping the location of small volcanic vents (small-vents) in the Tharsis province using MOLA, Thermal Emission Imaging System, and High Resolution Stereo Camera data [10]. Here we report on a preliminary study of the spatial and alignment relationships between small-vents south of Pavonis Mons, as determined by nearest neighbor and two-point azimuth statistical analyses. Terrestrial monogenetic volcanic fields display four fundamental characteristics: 1) recurrence rates of eruptions,2 ) vent abundance, 3) vent distribution, and 4) tectonic relationships [11]. While understanding recurrence rates typically requires field measurements, insight into vent abundance, distribution, and tectonic relationships can be established by mapping of remotely sensed data, and subsequent application of spatial statistical studies [11,12], the goal of which is to link the distribution of vents to causal processes.

  17. 49 CFR 179.300-13 - Venting, loading and unloading valves.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Venting, loading and unloading valves. 179.300-13... Venting, loading and unloading valves. (a) Valves shall be of approved type, made of metal not subject to rapid deterioration by lading, and shall withstand tank test pressure without leakage. The valves...

  18. Technology Solutions Case Study: Evaluation of Passive Vents in New-Construction Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    S. Puttagunta, S. Maxwell, D. Berger, and M. Zuluaga

    2015-10-01

    The Consortium for Advanced Residential Buildings (CARB) conducted research to gain more insight into passive vents. Because passive vents are meant to operate in a general environment of negative apartment pressure, the research assessed whether these negative pressures prevail through a variety of environmental conditions.

  19. 14 CFR 29.653 - Pressure venting and drainage of rotor blades.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pressure venting and drainage of rotor... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Design and Construction Rotors § 29.653 Pressure venting and drainage of rotor blades. (a) For each rotor blade— (1) There must...

  20. 14 CFR 27.653 - Pressure venting and drainage of rotor blades.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Pressure venting and drainage of rotor... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Design and Construction Rotors § 27.653 Pressure venting and drainage of rotor blades. (a) For each rotor blade— (1) There must be...

  1. 40 CFR 63.644 - Monitoring provisions for miscellaneous process vents.

    Science.gov (United States)

    2010-07-01

    ... detecting the presence of a pilot flame is required. (3) Any boiler or process heater with a design heat input capacity greater than or equal to 44 megawatt or any boiler or process heater in which all vent... less than 44 megawatts design heat capacity where the vent stream is not introduced into the flame...

  2. Comparative study of vent and seep macrofaunal communities in the Guaymas Basin

    Science.gov (United States)

    Portail, M.; Olu, K.; Escobar-Briones, E.; Caprais, J. C.; Menot, L.; Waeles, M.; Cruaud, P.; Sarradin, P. M.; Godfroy, A.; Sarrazin, J.

    2015-09-01

    Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico), the presence of seeps and vents in the absence of a biogeographic barrier, and comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem-specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep- and vent-common abiotic factors including methane and hydrogen sulfide concentrations, whereas vent environmental specificities (higher temperature, higher metal concentrations and lower pH) were not significant. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. At the family level, seep and vent similarity reached at least 58 %. All vent families were found at seeps and each seep-specific family displayed low relative abundances (< 5 %). Moreover, 85 % of the identified species among dominant families were shared between seep and vent ecosystems. This study provides further support to the hypothesis of continuity among deep-sea seep and vent ecosystems.

  3. DEVELOPMENT OF RECOMMENDATIONS AND METHODS TO SUPPORT ASSESSMENT OF SOIL VENTING PERFORMANCE AND CLOSURE: PUBLISHED REPORT

    Science.gov (United States)

    The purpose of this document is to improve the current "state of the art" and "state of the science" of soil venting application. A strategy is proposed for venting closure. A vadose zone paradigm is developed to dynamically link the performance of ground-water remediation to va...

  4. Survey of genome size in 28 hydrothermal vent species covering 10 families.

    Science.gov (United States)

    Bonnivard, Eric; Catrice, Olivier; Ravaux, Juliette; Brown, Spencer C; Higuet, Dominique

    2009-06-01

    Knowledge of genome size is a useful and necessary prerequisite for the development of many genomic resources. To better understand the origins and effects of DNA gains and losses among species, it is important to collect data from a broad taxonomic base, but also from particular ecosystems. Oceanic thermal vents are an interesting model to investigate genome size in very unstable environments. Here we provide data estimated by flow cytometry for 28 vent-living species among the most representative from different hydrothermal vents. We also report the genome size of closely related coastal decapods. Haploid C-values were compared with those previously reported for species from corresponding orders or infraorders. This is the first broad survey of 2C values in vent organisms. Contrary to expectations, it shows that certain hydrothermal vent species have particularly large genomes. The vent squat lobster Munidopsis recta has the largest genome yet reported for any anomuran: 2C=31.1 pg=30.4x10(9) bp. In several groups, such as Brachyura, Phyllodocida, and Veneroida, vent species have genomes that clearly rank at the high end of published values for each group. We also describe the highest DNA content yet recorded for the Brachyura (coastal crabs Xantho pilipes and Necora puber). Finally, analysis of genome size variation across populations revealed unexpected intraspecific variation in the vent shrimp Mirocaris fortunata that could not be attributed simply to ploidy changes.

  5. Characterization of On-Orbit U.S. Lab Condensate Vacuum Venting

    Science.gov (United States)

    Schmidl, W. D.; Alred, J. A.; Mikatarian, R.; Soares, C.; Miles, E.

    2002-01-01

    The venting of liquid streams into a vacuum has been studied extensively for many years. An experiment was performed aboard the International Space Station (ISS) to video tape the U.S. Lab's condensate venting event with cameras located on the Space Station Remote Manipulator System (SSRMS). Images of the vent plume were acquired close to both the port and starboard vent nozzles. The imaging started with a wider view and then zoomed in closer before the shutdown phase of the vent event occurred. The objective of this experiment was to extend our understanding of the properties of venting liquids into space. Data from the video images were analyzed to obtain the approximate cone angle encompassing the core of the vent plume. The condensate vent plume was characterized as having three phases, a startup phase, a nominal phase, and a shutdown phase. The startup phase consisted of the initial period when the vent first started and the liquid first entered the heated line. The nominal phase was the period when the majority of the liquid was vented. The shutdown phase occurs close to the end of the vent event. The shutdown phase was further divided into two parts, the shutdown initial phase, and a later shutdown sputtering phase. The shutdown initial phase occurs when gas becomes entrained in the condensate liquid being vented. The sputtering phase occurred after the vent valve was closed, and the liquid/ice in the line was removed by continuing to heat the line to bake it out. It was determined that the ice particles were ejected at higher angles, but lower velocities, during the startup and shutdown phases. The number and velocities of ice particles ejected outside of the core region, during the startup, initial shutdown and shutdown sputtering phases were determined. The core of liquid ejected during the startup and shutdown phases was contained within a half cone angle of less than 60 degrees. The startup phase took approximately 36 seconds, the shutdown initial phase

  6. Endemic hydrothermal vent species identified in the open ocean seed bank.

    Science.gov (United States)

    Gonnella, Giorgio; Böhnke, Stefanie; Indenbirken, Daniela; Garbe-Schönberg, Dieter; Seifert, Richard; Mertens, Christian; Kurtz, Stefan; Perner, Mirjam

    2016-01-01

    Hydrothermal vent systems host microbial communities among which several microorganisms have been considered endemic to this type of habitat. It is still unclear how these organisms colonize geographically distant hydrothermal environments. Based on 16S rRNA gene sequences, we compare the bacterial communities of sixteen Atlantic hydrothermal vent samples with our own and publicly available global open ocean samples. Analysing sequences obtained from 63 million 16S rRNA genes, the genera we could identify in the open ocean waters contained 99.9% of the vent reads. This suggests that previously observed vent exclusiveness is, in most cases, probably an artefact of lower sequencing depth. These findings are a further step towards elucidating the role of the open ocean as a seed bank. They can explain the predicament of how species expected to be endemic to vent systems are able to colonize geographically distant hydrothermal habitats and contribute to our understanding of whether 'everything is really everywhere'. PMID:27573109

  7. Endemic hydrothermal vent species identified in the open ocean seed bank.

    Science.gov (United States)

    Gonnella, Giorgio; Böhnke, Stefanie; Indenbirken, Daniela; Garbe-Schönberg, Dieter; Seifert, Richard; Mertens, Christian; Kurtz, Stefan; Perner, Mirjam

    2016-06-13

    Hydrothermal vent systems host microbial communities among which several microorganisms have been considered endemic to this type of habitat. It is still unclear how these organisms colonize geographically distant hydrothermal environments. Based on 16S rRNA gene sequences, we compare the bacterial communities of sixteen Atlantic hydrothermal vent samples with our own and publicly available global open ocean samples. Analysing sequences obtained from 63 million 16S rRNA genes, the genera we could identify in the open ocean waters contained 99.9% of the vent reads. This suggests that previously observed vent exclusiveness is, in most cases, probably an artefact of lower sequencing depth. These findings are a further step towards elucidating the role of the open ocean as a seed bank. They can explain the predicament of how species expected to be endemic to vent systems are able to colonize geographically distant hydrothermal habitats and contribute to our understanding of whether 'everything is really everywhere'.

  8. OECD/NEA/CSNI Status Report on Filtered Containment Venting

    International Nuclear Information System (INIS)

    This Status Report provides a comprehensive description of safety requirements associated with Filtered Containment Venting Systems (FCVSs) (Chapter 3) and of the status of FCVS implementation (Chapter 4) as provided by the various contributing countries. The different level of detail describing the accident management situation in different countries in relation to FCVS reflects in part the reality of the different levels of the current regulatory and/or technological appraisal of FCVS internationally. Further, the safety requirements differ in various countries being more-or-less prescriptive with FCVS not necessarily explicitly mandated or not considered as the primary measure to prevent containment over-pressurization. The following requirements may be prescribed for FCVS depending on venting strategies and objectives: vent capacity, vent opening and closing pressures, vent timing, venting system design requirements, consideration of possible hydrogen loads, radiological objectives, FCVS decontamination factors (DFs) for radioactive aerosols, for molecular iodine, etc. These are all discussed in detail in the report. A description of the FCV strategies for emergency operating procedures (EOPs) and SAM domains is provided in Chapter 5. FCVS are considered to be an additional system to protect the containment integrity. FCVSs are typically to be used in SAs as part of the overall applied SAM strategy for PWRs and BWRs, while they are also used in DBA for some PHWRs (CANDUs). Operation of a FCVS is also considered in some countries and for some reactor designs for accident management other than countering the long-term over-pressurization of the containment, e.g., for BWRs in the case of loss of heat sink to remove decay heat or to reduce the hydrogen inventory in the containment. Chapter 6 presents the well-known existing filtration technologies e.g., scrubbers, deep-bed filtration and different sorption systems. Details of systems for which information was

  9. Using Tables to Teach Mathematics.

    Science.gov (United States)

    Keller, Clifton

    1978-01-01

    The construction of tables of numbers is discussed as a learning activity that involves work in such things as reciprocals, calculators, formulas, patterns, discovery, prime numbers, and other types of numbers. (MP)

  10. The redoubtable ecological periodic table

    Science.gov (United States)

    Ecological periodic tables are repositories of reliable information on quantitative, predictably recurring (periodic) habitat–community patterns and their uncertainty, scaling and transferability. Their reliability derives from their grounding in sound ecological principle...

  11. The Table Mountain Field Site

    Data.gov (United States)

    Federal Laboratory Consortium — The Table Mountain Field Site, located north of Boulder, Colorado, is designated as an area where the magnitude of strong, external signals is restricted (by State...

  12. Investigating Late Amazonian Volcanotectonic Activity on Olympus Mons, Mars using Flank Vents and Arcuate Graben

    Science.gov (United States)

    Peters, S.; Christensen, P. R.

    2015-12-01

    Volcanism, a fundamental process in shaping the Martian surface, is crucial to understanding its evolution. Olympus Mons, the largest volcano on Mars, is one of several large shield volcanoes. Previous studies were technologically limited to large features associated with these constructs. With the advent of high resolution datasets, we are now able to investigate smaller features, such as flank vents and arcuate graben. Flank vents, common on polygenetic volcanoes, indicate that magma has propagated away from the main conduit and/or magma chamber. Vent morphology allows for the characterization of magma properties and eruption rates. Graben indicate extensional deformation. The distribution of graben provides information on stresses that acted on the volcano. In lieu of geophysical, spectral and in-situ data, morphology, morphometry and spatial relationships are powerful tools. We utilized high resolution image data (CTX, HiRISE and THEMIS IR) and topographic data (HRSC DTM, MOLA) to identify and characterize flank vents and graben. We observed 60 flank vents and 84 arcuate graben on Olympus Mons. Flank vents display varying morphologies and morphometries, suggesting different eruption styles and variable magma volatility. Vents occur primarily on the lower flank. This suggests magma has propagated substantial distances from the magma chamber. Observed clustering of vents may also indicate shallow magma sources. Similarly, graben are observed on the lower flank crosscutting young lava flows that have mantled portions of the escarpment. This indicates either gravitational spreading of Olympus Mons or flexure of the lithosphere in response to the load of the edifice. Collectively, the distribution of flank vents and arcuate graben suggests a similar development to that proposed for Ascraeus Mons. Based on superposition relationships and dates from previous studies, the flank vents and graben formed in the Late Amazonian (≤500 Ma).

  13. Bayesian analysis of contingency tables

    OpenAIRE

    Gómez Villegas, Miguel A.; González Pérez, Beatriz

    2005-01-01

    The display of the data by means of contingency tables is used in different approaches to statistical inference, for example, to broach the test of homogeneity of independent multinomial distributions. We develop a Bayesian procedure to test simple null hypotheses versus bilateral alternatives in contingency tables. Given independent samples of two binomial distributions and taking a mixed prior distribution, we calculate the posterior probability that the proportion of successes in the first...

  14. 30 CFR 250.1163 - How must I measure gas flaring or venting volumes and liquid hydrocarbon burning volumes, and...

    Science.gov (United States)

    2010-07-01

    ..., and Burning Hydrocarbons § 250.1163 How must I measure gas flaring or venting volumes and liquid... vented, and liquid hydrocarbons burned, to Minerals Revenue Management on Form MMS-4054 (Oil and Gas... gas flaring, gas venting, and liquid hydrocarbon burning for each facility for 6 years. (1) You...

  15. 40 CFR 63.7890 - What emissions limitations and work practice standards must I meet for process vents?

    Science.gov (United States)

    2010-07-01

    ... practice standards must I meet for process vents? 63.7890 Section 63.7890 Protection of Environment... Pollutants: Site Remediation Process Vents § 63.7890 What emissions limitations and work practice standards must I meet for process vents? (a) You must control HAP emissions from each new and existing...

  16. A Case of Successful Coil Embolization for a Late-Onset Type Ia Endoleak after Endovascular Aneurysm Repair with the Chimney Technique

    Directory of Open Access Journals (Sweden)

    Kimihiro Igari

    2016-01-01

    Full Text Available Juxtarenal aortic aneurysms (JRAAs are challenging to treat by endovascular aneurysm repair (EVAR procedures. The chimney technique with EVAR (Ch-EVAR is one of the feasible and less invasive treatments for JRAAs. However, the main concern of Ch-EVAR is the potential risk of “gutters,” which can lead to type Ia endoleak (EL. Most type Ia ELs after Ch-EVAR procedures occurred intraoperatively, and these ELs could be treated using an endovascular technique. However, late-onset type Ia ELs could be extremely rare, which might have a fear of conservative treatment. Type Ia ELs are associated with an increased risk of aneurysm rupture; therefore reintervention is recommended as soon as possible, and we should be aware of the occurrence of type Ia ELs after the Ch-EVAR procedure.

  17. 焦炉烟囱 NO x排放控制刍议%Comment on control of NOx emission from chimney of coke oven battery

    Institute of Scientific and Technical Information of China (English)

    蔡承祐

    2013-01-01

    The new national standard“ Emission standard of pollutants for coking chemical industry”regulates the requirement for control of NO x emission from chimney of coke oven battery .The techni-cal measures on design of heating system of coke oven battery and treatment of oven flue gas after it is discharged from the battery for control of NO x emission are expounded in this paper .The author also makes brief description of technology on denitrification of flue gas by using SCR process and sug -gests that in order to meet the requirement of the national standard for control of NO x emission from chimney of coke oven battery located in the “special region”, flue gas discharged from the coke oven battery should be further treated by using SCR denitrification technology with learning experience of Tokyo Gas gained from test of pilot plant and engineering .%新的国家标准《炼焦化学工业污染物排放标准》提出了焦炉烟囱的NOx 排放控制要求。本文从焦炉加热系统的设计和对焦炉烟道废气的后处理2个层面论述了焦炉烟囱NOx 排放控制的技术措施,简要介绍了SCR烟气脱硝技术,提出了借鉴日本东京煤气公司的中试与工程经验,采用SCR脱硝技术对焦炉烟道废气进行后处理,以达到国家标准对“特别地区”焦炉烟囱的NOx排放控制要求。

  18. Commissioning of filtered containment venting test loop Java plus

    Energy Technology Data Exchange (ETDEWEB)

    Beiseigel, A.; El-Rharbaoui, F.; Wich, M.

    2013-07-01

    AREVA GmbH operates a unique Thermal-hydraulic platform in Germany, France and USA. It is recognized as a test body according to ISO 17025. The Deutsche Akkreditierungsstelle GmbH (DAkkS - German Society for Accreditation) has also certified the Thermal-hydraulic platform as an independent inspection body Type C according to ISO 17020. A part of this platform is the Component Laboratory located in Karlstein, Germany which is in operation for more than 50 years. The testing activities cover a wide range as: Critical Heat Flux Tests, Valve Testing and LOCA Qualification of safety related components. Since 2012 the component Qualification Karlstein reactivated their testing scope for Filtered Containment Venting System (FCVS) Tests which is to our knowledge the largest (mass flow and volume) dedicated FCVS test facility.

  19. La mousson, pluie des agriculteurs et vent des marins

    OpenAIRE

    Aubaile-Sallenave, Françoise

    2014-01-01

    La mousson, c’est un mot arabe ayant une origine et une histoire propre. Ce sont aussi des vents et des courants marins qui vont de l’océan Indien aux mers de Chine et du Japon. C’est une zone de mouvements intenses mettant en contact des populations très diverses.La mousson a facilité depuis fort longtemps les voyages est - ouest (Chine vers Asie du sud-est et Inde) et ouest-est (Arabie vers Inde, Asie du sud-est et Chine), voyages qui donnent accès aux îles et presqu’îles de l’Asie du sud-e...

  20. Sperm ultrastructure of the hydrothermal vent octopod Vulcanoctopus hydrothermalis.

    Science.gov (United States)

    Roura, A; Guerra, A; González, A F; Pascual, S

    2010-08-01

    Sperm ultrastructure of the deep-sea hydrothermal vent octopod Vulcanoctopus hydrothermalis has been carried out by transmission electron microscopy. Spermatozoa of this species have the shortest head observed so far in octopodids. The acrosome possesses a helix with six gyres. The rod-shaped nucleus is short and wide in relation with other octopodids. Noteworthy features along the nucleus are the regularly disposed dense bands of cytoplasm, which have not been observed before in octopodids. The nuclear fossa is very short and wavy. Mitochondrial sheath has 10 elongated mitochondria running parallel to the axoneme-coarse fibers complex. Sperm morphology of V. hydrothermalis resembles that of Enteroctopus dofleini, suggesting a close phylogenetic relationship. PMID:20623654

  1. Lipid Adaptation of Shrimp Rimicaris exoculata in Hydrothermal Vent.

    Science.gov (United States)

    Zhu, Si; Ye, Mengwei; Yan, Xiaojun; Zhou, Yadong; Wang, Chunsheng; Xu, Jilin

    2015-12-01

    The shrimp Rimicaris exoculata is the most abundant species in hydrothermal vents. Lipids, the component of membranes, play an important role in maintaining their function normally in such extreme environments. In order to understand the lipid adaptation of R. exoculata (HV shrimp) to hydrothermal vents, we compared its lipid profile with the coastal shrimp Litopenaeus vannamei (EZ shrimp) which lives in the euphotic zone, using ultra performance liquid chromatography electrospray ionization-quadrupole time-of-flight mass spectrometry. As a result, the following lipid adaptation can be observed. (1) The proportion of 16:1 and 18:1, and non-methylene interrupted fatty acid (48.9 and 6.2 %) in HV shrimp was higher than that in EZ shrimp (12.7 and 0 %). While highly-unsaturated fatty acids were only present in the EZ shrimp. (2) Ceramide and sphingomyelin in the HV shrimp were enriched in d14:1 long chain base (96.5 and 100 %) and unsaturated fatty acids (67.1 and 57.7 %). While in the EZ shrimp, ceramide and sphingomyelin had the tendency to contain d16:1 long chain base (68.7 and 75 %) and saturated fatty acids (100 and 100 %). (3) Triacylglycerol content (1.998 ± 0.005 nmol/mg) in the HV shrimp was higher than that in the EZ shrimp (0.092 ± 0.005 nmol/mg). (4) Phosphatidylinositol and diacylglycerol containing highly-unsaturated fatty acids were absent from the HV shrimp. (5) Lysophosphatidylcholine and lysophosphatidylethanolamine were rarely detected in the HV shrimp. A possible reason for such differences was the result of food resources and inhabiting environments. Therefore, these lipid classes mentioned above may be the biomarkers to compare the organisms from different environments, which will be benefit for the further exploitation of the hydrothermal environment.

  2. Round table presentation

    International Nuclear Information System (INIS)

    Full text: This Round Table deals with the main problems in the operational implementation of radiation safety standards. I will not reiterate previous comments that were made in the other sessions and round tables but I will make a very wide and open presentation in this regard. Since we are discussing problems, I will present this from a general perspective and not just from a national one. So, in my experience problems result from two main causes: problems at the organization level and those due to unsolved or pending technical aspects. The first group concerns organizational problems. In my view, according to my experience, and not only in Argentina, the basic problems are usually related to ineffectual regulatory performance. Second, non-appropriate technical competence in radiation protection and safety matters at all levels; that means at worker, employer and regulatory levels. However, legal competence is a necessary condition but not a sufficient one. The basic point here is knowledge - knowledge and experience - and we can have a very formal and appropriate background of real competence, real instruments, but if we don't have real technical competence the results will not be very satisfactory. Another topic concerns the inadequate discharge of managerial responsibilities at the operational level and following on from this, a weak safety culture and a lack of an effective quality system. The operational implementation of radiation protection standards is often more formalistic than realistic. So in this type of case, for any given country, a commitment at a very high political level is a necessity. The second set of factors associated with such problems are unsolved or pending technical factors and in my view the issue with the complex system of exemption, clearance and action levels, particularly in the case of commodities, is to establish an adequate set of activity concentration levels for specific radionuclides, either natural or artificial, for

  3. Decline of a Hydrothermal Vent Field - Escanaba Trough 12 Years Later

    Science.gov (United States)

    Zierenberg, R. A.; Clague, D. A.; Davis, A. S.; Lilley, M. D.; McClain, J. S.; Olson, E. S.; Ross, S. L.; Von Damm, K. L.

    2001-12-01

    Hydrothermal venting was discovered in Escanaba Trough, the southern sediment-covered portion of the Gorda Ridge, in 1988. Large pyrrhotite-rich massive sulfide mounds are abundant at each of the volcanic/intrusive centers that have been investigated in Escanaba Trough, but the only area of known hydrothermal venting is the NESCA site along the ridge axis at 41\\deg N. Hydrothermal fluids venting at 217\\deg C and 108\\deg C were sampled in 1988 on two sulfide mounds separated by about 275 m. The end-member fluid compositions were indistinguishable within analytical errors. Several sulfide mounds were observed in 1988 which had diffusely venting low temperature (holes were drilled in the NESCA area in 1996 on ODP Leg 169, including Hole 1036I that penetrated to basaltic basement at 405 m below sea floor (mbsf). Surveys of the area using the drill string camera located only one area of active venting at the same mound where 217\\deg C vent fluids were sampled from two active vents in 1988. Drill hole 1036A was spudded between the two active vents on this sulfide mound (approximately 4 and 8 m away) and penetrated to 115 mbsf. The NESCA site was revisited in 2000 using MBARI's R/V Western Flyer and ROV Tiburon. The hydrothermal vents appeared essentially identical to observations made from the drill string camera in 1996 despite the presence of a drill hole within meters of the two vents. The maximum vent temperature measured in 2000 was 212\\deg C. Fluid samples have major element and isotopic compositions very similar to those collected in 1988. The vent fluids have higher methane ( ~19 mmol/kg) than those from the geologically similar Middle Valley vent field, but lower values than those at Guaymas Basin. Drill hole 1036A was weakly venting, but the diffuse hydrothermal fluids could not be sampled with the equipment available. The walls of the drill hole were colonized by palm worms, limpets, and snails. Four other drill holes showed no hydrothermal flow nor

  4. Quantifying dispersal from hydrothermal vent fields in the western Pacific Ocean.

    Science.gov (United States)

    Mitarai, Satoshi; Watanabe, Hiromi; Nakajima, Yuichi; Shchepetkin, Alexander F; McWilliams, James C

    2016-03-15

    Hydrothermal vent fields in the western Pacific Ocean are mostly distributed along spreading centers in submarine basins behind convergent plate boundaries. Larval dispersal resulting from deep-ocean circulations is one of the major factors influencing gene flow, diversity, and distributions of vent animals. By combining a biophysical model and deep-profiling float experiments, we quantify potential larval dispersal of vent species via ocean circulation in the western Pacific Ocean. We demonstrate that vent fields within back-arc basins could be well connected without particular directionality, whereas basin-to-basin dispersal is expected to occur infrequently, once in tens to hundreds of thousands of years, with clear dispersal barriers and directionality associated with ocean currents. The southwest Pacific vent complex, spanning more than 4,000 km, may be connected by the South Equatorial Current for species with a longer-than-average larval development time. Depending on larval dispersal depth, a strong western boundary current, the Kuroshio Current, could bridge vent fields from the Okinawa Trough to the Izu-Bonin Arc, which are 1,200 km apart. Outcomes of this study should help marine ecologists estimate gene flow among vent populations and design optimal marine conservation plans to protect one of the most unusual ecosystems on Earth.

  5. Quantifying dispersal from hydrothermal vent fields in the western Pacific Ocean.

    Science.gov (United States)

    Mitarai, Satoshi; Watanabe, Hiromi; Nakajima, Yuichi; Shchepetkin, Alexander F; McWilliams, James C

    2016-03-15

    Hydrothermal vent fields in the western Pacific Ocean are mostly distributed along spreading centers in submarine basins behind convergent plate boundaries. Larval dispersal resulting from deep-ocean circulations is one of the major factors influencing gene flow, diversity, and distributions of vent animals. By combining a biophysical model and deep-profiling float experiments, we quantify potential larval dispersal of vent species via ocean circulation in the western Pacific Ocean. We demonstrate that vent fields within back-arc basins could be well connected without particular directionality, whereas basin-to-basin dispersal is expected to occur infrequently, once in tens to hundreds of thousands of years, with clear dispersal barriers and directionality associated with ocean currents. The southwest Pacific vent complex, spanning more than 4,000 km, may be connected by the South Equatorial Current for species with a longer-than-average larval development time. Depending on larval dispersal depth, a strong western boundary current, the Kuroshio Current, could bridge vent fields from the Okinawa Trough to the Izu-Bonin Arc, which are 1,200 km apart. Outcomes of this study should help marine ecologists estimate gene flow among vent populations and design optimal marine conservation plans to protect one of the most unusual ecosystems on Earth. PMID:26929376

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

    Directory of Open Access Journals (Sweden)

    Church D

    2011-08-01

    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

  7. Shallow Water Hydrothermal Vents in the Gulf of California: Natural Laboratories for Multidisciplinary Research

    Science.gov (United States)

    Forrest, M.; Hilton, D. R.; Price, R. E.; Kulongoski, J. T.

    2015-12-01

    Modern and fossil examples of shallow water submarine hydrothermal vents occur throughout the Gulf of California. These sites offer important information about the processes involved in the extensional tectonics that created the Gulf of California and continue to shape the region to this day. Due to their accessibility, shallow water marine hydrothermal vents are far easier to access and study than their deeper analogs, and these settings can provide natural laboratories to study biogeochemical processes. Certain biogeochemical and biomineralizing processes occurring at shallow vents are very similar to those observed around deep-sea hydrothermal vents. In some cases, authigenic carbonates form around shallow vents. However, the hydrothermal precipitates are generally composed of Fe-oxyhydroxides, Mn-oxides, opal, calcite, pyrite and cinnabar, and their textural and morphological characteristics suggest microbial mediation for mineral deposition. Modern shallow-water hydrothermal vents also support complex biotic communities, characterized by the coexistence of chemosynthetic and photosynthetic organisms. These shallow vents are highly productive and provide valuable resources to local fishermen. Extant shallow water hydrothermal activity has been studied in Bahía Concepción, San Felipe, Punta Estrella, El Coloradito, Puertecitos, and around the Islas Encantadas. Discrete streams of gas bubbles are often discharged along with hot liquids at shallow water vents. The vent liquids generally exhibit lower salinities than seawater, and their isotopic compositions indicate that they contain meteoric water mixed with seawater. The composition of the shallow vent gas is primarily made up of CO2, but may also be enriched in N2, H2S, CH4, and other higher hydrocarbons. The geochemistry of these gases can be informative in determining the sources and processes involved in their generation. In particular, 3He/4He ratios may provide valuable information about the origin of

  8. An abyssal mobilome: viruses, plasmids and vesicles from deep-sea hydrothermal vents.

    Science.gov (United States)

    Lossouarn, Julien; Dupont, Samuel; Gorlas, Aurore; Mercier, Coraline; Bienvenu, Nadege; Marguet, Evelyne; Forterre, Patrick; Geslin, Claire

    2015-12-01

    Mobile genetic elements (MGEs) such as viruses, plasmids, vesicles, gene transfer agents (GTAs), transposons and transpovirions, which collectively represent the mobilome, interact with cellular organisms from all three domains of life, including those thriving in the most extreme environments. While efforts have been made to better understand deep-sea vent microbial ecology, our knowledge of the mobilome associated with prokaryotes inhabiting deep-sea hydrothermal vents remains limited. Here we focus on the abyssal mobilome by reviewing accumulating data on viruses, plasmids and vesicles associated with thermophilic and hyperthermophilic Bacteria and Archaea present in deep-sea hydrothermal vents.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-10-01

    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.

  10. Influence of wind effects on collapsing process of a chimney in blasting%爆破拆除烟囱倒塌过程中风效应影响研究

    Institute of Scientific and Technical Information of China (English)

    张宪堂; 王兆东; 王洪立; 王来

    2013-01-01

    在烟囱爆破拆除倒塌过程中,不同形式的风可使烟囱产生顺风向效应及横风向效应.横风向效应又包括横风向旋涡脱落及共振效应、横风向空气动力失稳.烟囱在风的长期作用下会发生失稳倾斜.揭示了爆破拆除过程中烟囱由于风振影响而发生倾斜、失稳的机理,分析了不同风向的三类风效应对爆破拆除时烟囱倒塌方向发生偏移的影响.根据分析计算结果可得,纵向风振影响最为显著,静力风效应影响相对较小,横向风振产生影响随机性较强.同时作者得出了爆破拆除烟囱时考虑风效应影响需采取的相应技术手段和措施.%In blasting demolition process of a chimney,along wind effect and across wind one are produced on the chimney under wind loads.The effect of across wind includes horizontal wind direction swirl,resonance effect and air dynamic destabilizing in horizontal wind direction.The long time action of wind load on a chimney during blasting demolition leads to sloping and destabilizing.The mechanism of sloping and destabilizing of a chimney due to windinduced vibration in its blasting demolition process was presented,and the deviations of the chimney collapsing direction during blasting demolition as results of three kinds of wind effect in different directions were analyzed.It was shown from the calculation results that the influence of along wind resonance is significant,the static wind effect is relatively small,and the influence of across wind resonance has a little stronger randomness.Also,the relevant technological measures needed considering the effect of wind in blasting demolition process of a chimney were obtained.

  11. The Alfonsine tables of Toledo

    CERN Document Server

    Chabás, José

    2003-01-01

    The Alfonsine Tables of Toledo is for historians working in the fields of astronomy, science, the Middle Ages, Spanish and other Romance languages. It is also of interest to scholars interested in the history of Castile, in Castilian-French relations in the Middle Ages and in the history of patronage. It explores the Castilian canons of the Alfonsine Tables and offers a study of their context, language, astronomical content, and diffusion. The Alfonsine Tables of Toledo is unique in that it: includes an edition of a crucial text in history of science; provides an explanation of astronomy as it was practiced in the Middle Ages; presents abundant material on early scientific language in Castilian; presents new material on the diffusion of Alfonsine astronomy in Europe; describes the role of royal patronage of science in a medieval context.

  12. General purpose steam table library :

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, John H.; Belcourt, Kenneth Noel; Nourgaliev, Robert

    2013-08-01

    Completion of the CASL L3 milestone THM.CFD.P7.04 provides a general purpose tabular interpolation library for material properties to support, in particular, standardized models for steam properties. The software consists of three parts, implementations of analytic steam models, a code to generate tables from those models, and an interpolation package to interface the tables to CFD codes such as Hydra-TH. Verification of the standard model is maintained through the entire train of routines. The performance of interpolation package exceeds that of freely available analytic implementation of the steam properties by over an order of magnitude.

  13. Volcanic carbon dioxide vents show ecosystem effects of ocean acidification.

    Science.gov (United States)

    Hall-Spencer, Jason M; Rodolfo-Metalpa, Riccardo; Martin, Sophie; Ransome, Emma; Fine, Maoz; Turner, Suzanne M; Rowley, Sonia J; Tedesco, Dario; Buia, Maria-Cristina

    2008-07-01

    The atmospheric partial pressure of carbon dioxide (p(CO(2))) will almost certainly be double that of pre-industrial levels by 2100 and will be considerably higher than at any time during the past few million years. The oceans are a principal sink for anthropogenic CO(2) where it is estimated to have caused a 30% increase in the concentration of H(+) in ocean surface waters since the early 1900s and may lead to a drop in seawater pH of up to 0.5 units by 2100 (refs 2, 3). Our understanding of how increased ocean acidity may affect marine ecosystems is at present very limited as almost all studies have been in vitro, short-term, rapid perturbation experiments on isolated elements of the ecosystem. Here we show the effects of acidification on benthic ecosystems at shallow coastal sites where volcanic CO(2) vents lower the pH of the water column. Along gradients of normal pH (8.1-8.2) to lowered pH (mean 7.8-7.9, minimum 7.4-7.5), typical rocky shore communities with abundant calcareous organisms shifted to communities lacking scleractinian corals with significant reductions in sea urchin and coralline algal abundance. To our knowledge, this is the first ecosystem-scale validation of predictions that these important groups of organisms are susceptible to elevated amounts of p(CO(2)). Sea-grass production was highest in an area at mean pH 7.6 (1,827 (mu)atm p(CO(2))) where coralline algal biomass was significantly reduced and gastropod shells were dissolving due to periods of carbonate sub-saturation. The species populating the vent sites comprise a suite of organisms that are resilient to naturally high concentrations of p(CO(2)) and indicate that ocean acidification may benefit highly invasive non-native algal species. Our results provide the first in situ insights into how shallow water marine communities might change when susceptible organisms are removed owing to ocean acidification.

  14. Overview of Vent Fluid Chemistry From the Marianas Volcanic Arc

    Science.gov (United States)

    Butterfield, D. A.; Roe, K. K.; Bolton, S. A.; Baross, J. A.; Lupton, J. E.; Lilley, M. D.; Embley, R. W.; Chadwick, W. W.; Resing, J. A.

    2004-12-01

    In March and April 2004, a research expedition on the R.V.T.G. Thompason with the ROV ROPOS investigated and sampled hydrothermal systems on six submarine volcanoes of the Marianas volcanic arc between 14.3 and 21.5 degrees N. In this two-year project sponsored by NOAA Ocean Exploration, dive targets were selected based on bathymetric and hydrothermal plume mapping conducted in 2003. Hydrothermal plume intesity and chemistry was used with success to target and sample a remarkable variety of volcanic and hydrothermal features. At NW Rota-1 submarine volcano, there is clear evidence of ongoing eruptive activity producing clouds of particulate and molten sulfur as well as mm to cm-size glassy volcanic ejecta. Fluids (34 deg C) sampled directly from an eruptive pit crater has pH of 2.0, with a high content of particulated sulfur, excess sulfate relative to seawater, and very low H2s content. Fluids percolating through volcaniclastic sand adjacent to the pit reached 100 deg C and had higher silica, slightly higher pH, and millimolar levels of H2s. The chemistry of both types of fluids is indicative of input of volcanic SO2 and disproportionation into sulfate and H2s (in volcaniclastic sands) and elemental sulfur (in the pit crater). Molten sulfur droplets indicate a high-temperature source at the base of the pit crater that rapidly mixes with seawater, while fluids venting through the sand remain hotter and react with volcanic glass. DNA was collected by in-situ filtration and both archaea and bacteria were amplified by PCR. Bacterial clone libraries were dominated by epsilon Proteobacteria with a high degree of relatedness to microaerophilic sulfur-, sulfide-, and hydrogen oxidizers belonging to the genera Sulfurimonas and Calderomonas. At East Diamante submarine volcano, several hydrothermal areas were found on resurgent domes within the large caldera. One of these sites hosted the only high-temperature deposits. The high volatile content of the volcanic arc

  15. Vented target elements for use in an isotope-production reactor. [LMFBR

    Science.gov (United States)

    Cawley, W.E.; Omberg, R.P.

    1982-08-19

    A method is described for producing tritium gas in a fast breeder reactor cooled with liquid metal. Lithium target material is placed in pins equipped with vents, and tritium gas is recovered from the coolant.

  16. Reactor pressure vessel head vents and methods of using the same

    Science.gov (United States)

    Gels, John L; Keck, David J; Deaver, Gerald A

    2014-10-28

    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.

  17. Arsenic speciation in shrimp and mussel from the Mid-Atlantic hydrothermal vents

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Quetel, C. R.; Munoz, R.;

    1997-01-01

    Specimens of shrimp (Rimicaris exoculata) and mussel (Bathymodiolus puteoserpentis) were collected 3500 m below the ocean surface at the hydrothermal vents of the mid-Atlantic Ridge (TAG and Snake Pit sites, respectively). Arsenic, a potentially toxic element, is among the substances emitted...... by the hydrothermal vents. The hydrothermal vent shrimp, which are known to be a primary consumer of the primary producing chemolithoautotrophic bacteria, contained arsenic at 13 mu g g(-1) almost exclusively as arsenobetaine (AsB). Arsenic was present in the soft:issues of the mussel at 40 mu g g(-1) and the major...... of arsenic species found in the shrimp and mussel species in the deep-sea is similar to that found in their counterparts from the ocean surface. It is concluded that the autotrophic bacteria of the hydrothermal vent ecosystem and the symbiotic bacteria harboured in the mussel species are responsible...

  18. Partitioning Between Plume and Diffuse Flow at the Grotto Vent Cluster, Main Endeavour Vent Field, Juan de Fuca Ridge: Past and Present

    Science.gov (United States)

    Rona, P. A.; Bemis, K. G.; Jones, C.; Jackson, D. R.; Mitsuzawa, K.; Palmer, D. R.

    2010-12-01

    Seafloor hydrothermal systems discharge as plumes from discrete vents and as diffuse flow from surrounding areas that transfer heat and chemicals from the lithosphere into the ocean in quantitatively significant amounts. Our VIP (Vent Imaging Pacific) July 2000 experiment was designed to acoustically image and quantify these flows at vent clusters in the Main Endeavour field using a sonar system (Simrad SM 2000) mounted on ROV Jason from fixed positions on the seafloor using three methods that we developed. Buoyant plumes are reconstructed applying visualization techniques to volume backscatter from suspended particulates and density discontinuities in plumes. A Doppler algorithm is used to measure mean vertical velocity through plume cross sections and to calculate volume flux at different altitudes in a plume. Acoustic Scintillation Thermography (AST) is used to image irregular areas of diffuse flow. Results from a sulfide edifice (north tower of Grotto Vent cluster; height 12 m; diameter 10 m; sonar range 12 m) supplemented by additional AST measurements and in situ measurements of flow rate and temperature are tabulatd below: The higher diffuse than plume heat flux is consistent with prior studies at other sites. However, the ratio of diffuse to plume heat flux (range 23-353) is exceptionally large suggesting an overestimation of diffuse flow area at the high end and/or underestimation of plume flux. We are scheduled this fall to connect our next generation sonar system (COVIS=Cable Operated Vent Imaging Sonar) to the NEPTUNE Canada cabled observatory at the Grotto vent cluster. COVIS is designed to image plume and diffuse flow in space and in time, which will contribute to interpreting our past observations and to provide new insights on how partitioning may vary with time.

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

    Science.gov (United States)

    Inskeep, William P; Jay, Zackary J; Macur, Richard E; Clingenpeel, Scott; Tenney, Aaron; Lovalvo, David; Beam, Jacob P; Kozubal, Mark A; Shanks, W C; Morgan, Lisa A; Kan, Jinjun; Gorby, Yuri; Yooseph, Shibu; Nealson, Kenneth

    2015-01-01

    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 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°C) 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. PMID:26579074

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

    OpenAIRE

    Inskeep, William P.; Jay, Zackary J.; Macur, Richard E.; Clingenpeel, Scott; Tenney, Aaron; Lovalvo, David; Beam, Jacob P; Mark A Kozubal; Shanks, W. C.; Lisa A Morgan; Kan, Jinjun; Gorby, Yuri; Yooseph, Shibu; Nealson, Kenneth

    2015-01-01

    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 using 16S rRNA gene and random metagenome sequencing, and to determine how geochemical attributes of vent waters influence the distribution of specific ...

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

    OpenAIRE

    Inskeep, William P.

    2015-01-01

    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 distri...

  2. 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

    2015-10-01

    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.

  3. Technology Solutions Case Study: Design Guidance for Passive Vents in New Construction, Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-02-12

    In an effort to improve indoor air quality in high-performance, new construction, multifamily buildings, dedicated sources of outdoor air are being implemented. Passive vents are being selected by some design teams over other strategies because of their lower first costs and operating costs. The U.S. Department of Energy’s Building America research team Consortium for Advanced Residential Buildings constructed eight steps, which outline the design and commissioning required for these passive vents to perform as intended.

  4. Comparative Composition, Diversity and Trophic Ecology of Sediment Macrofauna at Vents, Seeps and Organic Falls

    OpenAIRE

    Bernardino, Angelo F.; Levin, Lisa A; Thurber, Andrew R; Smith, Craig R.

    2012-01-01

    Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but there has yet to be a systematic comparison of the community-level attributes of sediment macrobenthos in various reducing ecosystems. Here we review key s...

  5. Novel Forms of Structural Integration between Microbes and a Hydrothermal Vent Gastropod from the Indian Ocean

    OpenAIRE

    Goffredi, Shana K.; Warén, Anders; Orphan, Victoria J; Van Dover, Cindy L.; Vrijenhoek, Robert C

    2004-01-01

    Here we describe novel forms of structural integration between endo- and episymbiotic microbes and an unusual new species of snail from hydrothermal vents in the Indian Ocean. The snail houses a dense population of {gamma}-proteobacteria within the cells of its greatly enlarged esophageal gland. This tissue setting differs from that of all other vent mollusks, which harbor sulfur-oxidizing endosymbionts in their gills. The significantly reduced digestive tract, the isotopic signatures of the ...

  6. Temporal and spatial variation in temperature experienced by macrofauna at main endeavour Hydrothermal vent field

    OpenAIRE

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

    2015-01-01

    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...

  7. Hydrogen-limited growth of hyperthermophilic methanogens at deep-sea hydrothermal vents

    OpenAIRE

    Ver Eecke, Helene C.; David A Butterfield; Julie A. Huber; Lilley, Marvin D.; Olson, Eric J.; Roe, Kevin K.; Evans, Leigh J.; Merkel, Alexandr Y.; Cantin, Holly V.; Holden, James F.

    2012-01-01

    Microbial productivity at hydrothermal vents is among the highest found anywhere in the deep ocean, but constraints on microbial growth and metabolism at vents are lacking. We used a combination of cultivation, molecular, and geochemical tools to verify pure culture H2 threshold measurements for hyperthermophilic methanogenesis in low-temperature hydrothermal fluids from Axial Volcano and Endeavour Segment in the northeastern Pacific Ocean. Two Methanocaldococcus strains from Axial and Methan...

  8. Preliminary Modeling of Two-Phase Flow at the Main Endeavour Vent Field

    Science.gov (United States)

    Singh, S.; Lowell, R. P.

    2011-12-01

    The high temperature hydrothermal vents of Main Endeavour Field (MEF), Juan de Fuca ridge exhibited quasi-steady North-South trending spatial gradients of both temperature and salinity for more than a decade before a magmatic event changed the vent characteristics. In order to explain these observations, we construct two-dimensional numerical models of two-phase hydrothermal flow of the MEF. We consider both along-axis and across-axis simulations, taking into account the vent field geometry and incorporating various parameters, such as different basal temperature distributions and permeability structures that might affect the vent fluid temperature and chemistry. Preliminary results from across-axis models, in which the basal temperature decreases linearly away from the ridge axis and results in a single high-temperature plume, indicate that basal temperature alone does not affect steady-state vent temperature and salinity of the vents. Simulations that include the presence of a high-permeability extrusive layer 2A atop the spreading ridge results in a zone of narrower and lower temperature venting. The effect of a low permeability zone of anhydrite would tend to mitigate the decrease in temperature, however. Along-axis simulations performed to date, with an extended uniform high temperature basal boundary, produce multiple plumes; but the plumes do not exhibit a strong along-axis gradient in vent salinity or temperature as observed at the MEF. These preliminary results suggest that the observed N-S gradient in temperature and salinity at MEF reflects interplay between heat source and either near the surface or deep-seated heterogeneous permeability structures. Three-dimensional simulations might ultimately be required to understand hydrothermal circulation at the MEF.

  9. 40 CFR 63.115 - Process vent provisions-methods and procedures for process vent group determination.

    Science.gov (United States)

    2010-07-01

    ... provided in table 2 of subpart F of this part. (4) Where Method 25A of 40 CFR part 60, appendix A is used... engineering assessment and the TRE equation in paragraph (d)(3) of this section is greater than 4.0, then the... paragraph (d)(3) of this section is less than or equal to 4.0, then the owner or operator is required...

  10. table tennis的来历

    Institute of Scientific and Technical Information of China (English)

    王淑清

    2006-01-01

    乒乓球运动在运动史上是一项年轻的体育运动,只有100多年的历史,乒乓球的英文名称有table tennis和ping-pong两种。Table tennis出现不久,便成了一种风靡一时的热门运动。20世纪初,美国开始成套地生产乒乓球的比赛用具。最初,table tennis有其他名称 ,如Indoor tennis。后来,一位美国制造商以乒乓球撞击时所发出的声音创造出ping-pong这个新词,作为他们制造的“乒乓球”专利注册商标。Ping-pong后来成了table tennis的另一个正式名。当它传到中国后,人们又创造出“乒乓球”这个新的词语。

  11. Putting food on the table

    NARCIS (Netherlands)

    Candel, J.J.L.

    2016-01-01

    Putting food on the table: the European Union governance of the wicked problem of food security Jeroen Candel Food security concerns and arguments have made a revival in European Union (EU) governance since the 2007-8 and 2010 global food price crises. This renaissa

  12. A conduit dilation model of methane venting from lake sediments

    Science.gov (United States)

    Scandella, B.P.; Varadharajan, C.; Hemond, Harold F.; Ruppel, C.; Juanes, R.

    2011-01-01

    Methane is a potent greenhouse gas, but its effects on Earth's climate remain poorly constrained, in part due to uncertainties in global methane fluxes to the atmosphere. An important source of atmospheric methane is the methane generated in organic-rich sediments underlying surface water bodies, including lakes, wetlands, and the ocean. The fraction of the methane that reaches the atmosphere depends critically on the mode and spatiotemporal characteristics of free-gas venting from the underlying sediments. Here we propose that methane transport in lake sediments is controlled by dynamic conduits, which dilate and release gas as the falling hydrostatic pressure reduces the effective stress below the tensile strength of the sediments. We test our model against a four-month record of hydrostatic load and methane flux in Upper Mystic Lake, Mass., USA, and show that it captures the complex episodicity of methane ebullition. Our quantitative conceptualization opens the door to integrated modeling of methane transport to constrain global methane release from lakes and other shallow-water, organic-rich sediment systems, and to assess its climate feedbacks.

  13. 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)

    1997-08-01

    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.

  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)

    1997-08-01

    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. Acoustic communication in the Red-vented Bulbul Pycnonotus cafer

    Directory of Open Access Journals (Sweden)

    Kumar Anil

    2004-01-01

    Full Text Available This paper deals with acoustic communication in the Red-vented Bulbul Pycnonotus cafer. This species emits a high variety of vocal signals that can be classified on the basis of their acoustical features and context of production. Individuals sang throughout the year and most songs were discrete and stereotyped. The songs were composed of strophes (phrases with minor structural variations of elements that were preceded and followed by a temporal gap (3 to 12s. Most strophes were composed of 2 to 6 elements that were often dissimilar in structure and ranging from 0.98 to 4.5 kHz. The biological function of the song appeared to be to maintain pair bonds and to synchronize breeding activities. Different types of context-specific calls were identified. Individuals produced Type-I alarm calls (fast and wide-band, 1.03 to 6.36 kHz under low predation pressure andType-II calls (narrowfrequency range, 1.37 to 3.39 kHz under high predation pressure. Roosting calls were fast and wide-band signals phonetically similar to Type-I alarm calls. Three types of begging/contact calls were recorded in nestlings/fledglings. Greeting calls and flight calls were composed of complex phrases, like song, but were short and used for proximate functions.

  16. Patterning the early zebrafish by the opposing actions of bozozok and vox/vent.

    Science.gov (United States)

    Melby, A E; Beach, C; Mullins, M; Kimelman, D

    2000-08-15

    Fish and frog embryos are patterned along the dorsal-ventral axis during the gastrula stage by opposing gradients of Bmps and Bmp inhibitory proteins. Three transcriptional repressors with partially overlapping expression domains have been proposed to be important mediators of Bmp function in Xenopus. We find that two related factors are expressed in the early zebrafish embryo. Although these factors are considerably divergent from the related Xenopus genes, they are expressed in domains similar to those of their Xenopus relatives throughout embryogenesis. Both of the zebrafish genes, which we have named vox and vent, are potent ventralizing factors in both zebrafish and Xenopus embryos. Using mutants in the Bmp pathway, we find that there are Bmp-dependent and Bmp-independent domains of vox expression, whereas vent is mostly dependent upon Bmp signaling. We show that ectopic vox or vent negatively regulates expression of the early dorsal gene bozozok (boz) and that ectopic boz eliminates vox and vent expression. Moreover, the normal exclusion of vox and vent from the organizer region is lost in boz mutant embryos. Our results show that boz and vox/vent are mutually antagonistic and indicate that the early establishment of the size of the organizer domain is dependent on an interplay between these early expressed transcriptional repressors. PMID:10926766

  17. Spatial distribution pattern of seafloor hydrothermal vents to the southeastern Kueishan Tao offshore Taiwan Island

    Institute of Scientific and Technical Information of China (English)

    HAN Chenhua; YE Ying; PAN Yiwen; QIN Huawei; WU Guanghai; CHEN Chen-Tung Arthur

    2014-01-01

    Investigations of the diffusion activities both within and outside the seafloor hydrothermal vents, as well as related mineral genesis, have been one of the key focuses of ocean biogeochemistry studies. Many hy-drothermal vents are distributed close to the southern Okinawa Trough on the less-than-30-m deep shal-low seafloor off Kueishan Tao, northeast of Taiwan Island. Investigations of temperature, pH and Eh at four depths of hydrothermal plume were carried out near Kueishan Tao at the white (24.83°N, 121.96°E) and yellow (24.83°N, 121.96°E) vents. An 87 h of temperature time series observation-undertaken near the white vent showed that tide is the main factor affecting the background environment. Based on the observed data, 3-dimensional sliced diffusion fields were obtained and analyzed. It was concluded that the plume diffused mainly from north to south due to ebb tide. The yellow vent’s plume could effect as far as the white vent surface. From the temperature diffusion field, the vortices of the plume were observed. The Eh negative abnormality was a better indicator to search for hydrothermal plumes and locate hydrothermal vents than high temperature and low pH abnormalities.

  18. Characterizing the distribution and rates of microbial sulfate reduction at Middle Valley hydrothermal vents.

    Science.gov (United States)

    Frank, Kiana L; Rogers, Daniel R; Olins, Heather C; Vidoudez, Charles; Girguis, Peter R

    2013-07-01

    Few studies have directly measured sulfate reduction at hydrothermal vents, and relatively little is known about how environmental or ecological factors influence rates of sulfate reduction in vent environments. A better understanding of microbially mediated sulfate reduction in hydrothermal vent ecosystems may be achieved by integrating ecological and geochemical data with metabolic rate measurements. Here we present rates of microbially mediated sulfate reduction from three distinct hydrothermal vents in the Middle Valley vent field along the Juan de Fuca Ridge, as well as assessments of bacterial and archaeal diversity, estimates of total biomass and the abundance of functional genes related to sulfate reduction, and in situ geochemistry. Maximum rates of sulfate reduction occurred at 90 °C in all three deposits. Pyrosequencing and functional gene abundance data revealed differences in both biomass and community composition among sites, including differences in the abundance of known sulfate-reducing bacteria. The abundance of sequences for Thermodesulfovibro-like organisms and higher sulfate reduction rates at elevated temperatures suggests that Thermodesulfovibro-like organisms may have a role in sulfate reduction in warmer environments. The rates of sulfate reduction presented here suggest that--within anaerobic niches of hydrothermal deposits--heterotrophic sulfate reduction may be quite common and might contribute substantially to secondary productivity, underscoring the potential role of this process in both sulfur and carbon cycling at vents.

  19. Community Structure Comparisons of Hydrothermal Vent Microbial Mats Along the Mariana Arc and Back-arc

    Science.gov (United States)

    Hager, K. W.; Fullerton, H.; Moyer, C. L.

    2015-12-01

    Hydrothermal vents along the Mariana Arc and back-arc represent a hotspot of microbial diversity that has not yet been fully recognized. The Mariana Arc and back-arc contain hydrothermal vents with varied vent effluent chemistry and temperature, which translates to diverse community composition. We have focused on iron-rich sites where the dominant primary producers are iron oxidizing bacteria. Because microbes from these environments have proven elusive in culturing efforts, we performed culture independent analysis among different microbial communities found at these hydrothermal vents. Terminal-restriction fragment length polymorphism (T-RFLP) and Illumina sequencing of small subunit ribosomal gene amplicons were used to characterize community members and identify samples for shotgun metagenomics. Used in combination, these methods will better elucidate the composition and characteristics of the bacterial communities at these hydrothermal vent systems. The overarching goal of this study is to evaluate and compare taxonomic and metabolic diversity among different communities of microbial mats. We compared communities collected on a fine scale to analyze the bacterial community based on gross mat morphology, geography, and nearby vent effluent chemistry. Taxa richness and evenness are compared with rarefaction curves to visualize diversity. As well as providing a survey of diversity this study also presents a juxtaposition of three methods in which ribosomal small subunit diversity is compared with T-RFLP, next generation amplicon sequencing, and metagenomic shotgun sequencing.

  20. Comparative study of vent and seep macrofaunal communities in the Guaymas Basin

    Directory of Open Access Journals (Sweden)

    M. Portail

    2015-06-01

    Full Text Available Understanding the ecological processes and connectivity of chemosynthetic deep-sea ecosystems requires comparative studies. In the Guaymas Basin (Gulf of California, Mexico, the presence of seeps and vents in the absence of biogeographic barrier, comparable sedimentary settings and depths offers a unique opportunity to assess the role of ecosystem specific environmental conditions on macrofaunal communities. Six seep and four vent assemblages were studied, three of which were characterised by common major foundation taxa: vesicomyid bivalves, siboglinid tubeworms and microbial mats. Macrofaunal community structure at the family level showed that density, diversity and composition patterns were primarily shaped by seep and vent common abiotic factors including methane and hydrogen sulphide concentrations. The type of substratum and the heterogeneity provided by foundation species were identified as additional structuring factors and their roles were found to vary according to fluid regimes. Surprisingly, the presence of vent environmental specificities, with higher temperature, higher metal concentrations and lower pH was not significant in explaining community patterns. Moreover, Guaymas seep and vent shared an important number of common species suggesting frequent connections between the two ecosystems. Finally, this study provides further support for the hypothesis of continuity among deep-sea seep and vent ecosystems.

  1. Mark III confirmatory test program: one third scale, three vent air tests

    International Nuclear Information System (INIS)

    A series of air blowdown tests was run to evaluate pool swell phenomena for the Mark III pressure suppression containment concept. The tests were performed at the Pressure Suppression Test Facility which consists of an integrated system of drywell, vent system, and suppression pool. The volumetric scale factor used for facility design was nominally 1:130, based on the BWR 6/251 series Mark III containment design. The pool and vent system both represented one-third scale mockups of an 8-degree sector of the Mark III containment, including a vertical row of three 157/8 in. (403 mm)-diameter horizontal vents. Test parameters changed were blowdown flow restrictor size and top vent centerline submergence. The transient responses of the pressurizer, drywell, vent system, suppression pool, and wetwell air space were measured and analyzed for use in formulating and/or further confirming the analytical models used for predicting loss-of-coolant accident transients. Results supported previously reported conclusions. Air blowdown tests with comparable drywell pressure transients were shown to have somewhat higher pool swell velocities than previously reported steam tests. The air tests provided additional evidence that bubble breakthrough elevation is not dependent upon charging rate but is determined almost exclusively by initial vent submergence. Total impulse values on the pool ceiling for the air tests were found to be lower than comparable steam tests

  2. Experimental investigation on No-Vent Fill (NVF) process using liquid Nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Young Cheol; Seo, Man Su; Yoo, Dong Gyu; Jeong, Sang Kwon [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of)

    2014-12-15

    For a long-term space mission, filling process of cryogenic liquid propellant is operated on a space vehicle in space. A vent process during transfer and filling of cryogenic propellant is needed to maintain the fuel tank pressure at a safe level due to its volatile characteristic. It is possible that both liquid and vapor phases of the cryogenic propellant are released simultaneously to outer space when the vent process occurs under low gravity environment. As a result, the existing filling process with venting not only accompanies wasting liquid propellant, but also consumes extra fuel to compensate for the unexpected momentum originated from the vent process. No-Vent Fill (NVF) method, a filling procedure without a venting process of cryogenic liquid propellant, is an attractive technology to perform a long-term space mission. In this paper, the preliminary experimental results of the NVF process are described. The experimental set-up consists of a 9-liter cryogenic liquid receiver tank and a supply tank. Liquid nitrogen (LN2) is used to simulate the behavior of cryogenic propellant. The whole situation in the receiver tank during NVF is monitored. The major experimental parameter in the experiment is the mass flow rate of the liquid nitrogen. The experimental results demonstrate that as the mass flow rate is increased, NVF process is conducted successfully. The quality and the inlet temperature of the injected LN2 are affected by the mass flow rate. These parameters determine success of NVF.

  3. Heat flux estimates from the Gakkel Ridge 85E vent field from the AGAVE 2007 expedition

    Science.gov (United States)

    Stranne, C.; Winsor, P.; Sohn, R. A.; Liljebladh, B.

    2009-04-01

    During the Arctic Gakkel Vents Expedition (AGAVE) 2007, abundant hydrothermal venting was discovered on the Gakkel Ridge at 85E. Hydrothermal vents on the sea floor give rise to buoyant plumes which, when reaching neutral buoyancy, spreads horizontally over areas with length scales on the order of several kilometres and are therefore easily detected with a CTD rosette. The detected anomalies are consistent with the findings 6 years earlier during the Arctic Mid-Ocean Ridge Expedition (AMORE) 2001. The horizontal and vertical distribution of the anomalies is considered in order to establish the number of individual plumes detected. The objective of this paper is to estimate the minimum heat input required to reproduce the observed plumes, using a turbulent entrainment model. The model was run with a large number of combinations of boundary conditions (nozzle area, vertical velocity and temperature) in order to see which combinations that give rise to the observed plume characteristics (level of neutral buoyancy and temperature anomaly). For each individual plume, we estimate the minimum heat flux required to obtain the observed temperature anomaly. Adding the minimum heat flux from each vent together, the total heat flux for the vent field is estimated to be ~ 2 GW. The estimated value is comparable or larger than any other known vent field.

  4. 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

    2012-01-01

    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

  5. Water-table contours of Nevada

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set consists of water-table contours for Nevada. These data were created as part of an effort to provide statewide information on water table and depth to...

  6. NNDSS - Table II. Shiga toxin to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Shiga toxin to Shigellosis - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the...

  7. NNDSS - Table II. Chlamydia to Coccidioidomycosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  8. NNDSS - Table II. Mumps to Rabies, animal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Mumps to Rabies, animal - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  9. NNDSS - Table II. Ehrlichiosis/Anaplasmosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Ehrlichiosis/Anaplasmosis - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the...

  10. NNDSS - Table II. Mumps to Rabies, animal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Mumps to Rabies, animal - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000 cases but...

  11. NNDSS - Table II. Ehrlichiosis/Anaplasmosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Ehrlichiosis/Anaplasmosis - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000 cases but...

  12. NNDSS - Table II. Shiga toxin to Shigellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Shiga toxin to Shigellosis - 2015. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  13. NNDSS - Table II. Babesiosis to Campylobacteriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Campylobacteriosis - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the...

  14. NNDSS - Table II. Babesiosis to Campylobacteriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Babesiosis to Campylobacteriosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...

  15. NNDSS - Table II. Rubella to Salmonellosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Rubella to Salmonellosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  16. NNDSS - Table II. Ehrlichiosis/Anaplasmosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Ehrlichiosis/Anaplasmosis - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding...

  17. NNDSS - Table II. Chlamydia to Coccidioidomycosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Chlamydia to Coccidioidomycosis - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the...

  18. NNDSS - Table II. Tetanus to Vibriosis

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Tetanus to Vibriosis - 2016. In this Table, provisional* cases of selected†notifiable diseases (≥1,000 cases reported during the preceding...

  19. New algebraic tables of SU(2) quantities

    International Nuclear Information System (INIS)

    Formulas for Clebsch-Gordan Coefficients, 6-j symbols and 9-j symbols of SU(2) are presented in a ready-to-program way for obtaining algebraic tables. An excerpt of the complete tables are also presented. (Author)

  20. Solar Cell Efficiency Tables (Version 48)

    Energy Technology Data Exchange (ETDEWEB)

    Green, Martin A.; Emery, Keith; Hishikawa, Yoshihiro; Warta, Wilhelm; Dunlop, Ewan D.

    2016-07-01

    Consolidated tables showing an extensive listing of the highest independently confirmed efficiencies for solar cells and modules are presented. Guidelines for inclusion of results into these tables are outlined, and new entries since January 2016 are reviewed.