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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. 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

  4. 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

  5. 40 CFR Table 3 to Subpart Ooo of... - Batch Process Vent Monitoring Requirements

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Batch Process Vent Monitoring... Resins Pt. 63, Subpt. OOO, Table 3 Table 3 to Subpart OOO of Part 63—Batch Process Vent Monitoring... the batch process vents or aggregate batch vent streams are not introduced with or used as the...

  6. Bacterial Lifestyle in a Deep-sea Hydrothermal Vent Chimney Revealed by the Genome Sequence of the Thermophilic Bacterium Deferribacter desulfuricans SSM1

    OpenAIRE

    Takaki, Yoshihiro; Shimamura, Shigeru; Nakagawa, Satoshi; Fukuhara, Yasuo; Horikawa, Hiroshi; Ankai, Akiho; Harada, Takeshi; Hosoyama, Akira; Oguchi, Akio; Fukui, Shigehiro; Fujita, Nobuyuki; Takami, Hideto; Takai, Ken

    2010-01-01

    The complete genome sequence of the thermophilic sulphur-reducing bacterium, Deferribacter desulfuricans SMM1, isolated from a hydrothermal vent chimney has been determined. The genome comprises a single circular chromosome of 2 234 389 bp and a megaplasmid of 308 544 bp. Many genes encoded in the genome are most similar to the genes of sulphur- or sulphate-reducing bacterial species within Deltaproteobacteria. The reconstructed central metabolisms showed a heterotrophic lifestyle primarily d...

  7. 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...

  8. 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.

    2016-01-01

    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

  9. 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...

  10. 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...

  11. 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

  12. Bacterial lifestyle in a deep-sea hydrothermal vent chimney revealed by the genome sequence of the thermophilic bacterium Deferribacter desulfuricans SSM1.

    Science.gov (United States)

    Takaki, Yoshihiro; Shimamura, Shigeru; Nakagawa, Satoshi; Fukuhara, Yasuo; Horikawa, Hiroshi; Ankai, Akiho; Harada, Takeshi; Hosoyama, Akira; Oguchi, Akio; Fukui, Shigehiro; Fujita, Nobuyuki; Takami, Hideto; Takai, Ken

    2010-06-01

    The complete genome sequence of the thermophilic sulphur-reducing bacterium, Deferribacter desulfuricans SMM1, isolated from a hydrothermal vent chimney has been determined. The genome comprises a single circular chromosome of 2,234,389 bp and a megaplasmid of 308,544 bp. Many genes encoded in the genome are most similar to the genes of sulphur- or sulphate-reducing bacterial species within Deltaproteobacteria. The reconstructed central metabolisms showed a heterotrophic lifestyle primarily driven by C1 to C3 organics, e.g. formate, acetate, and pyruvate, and also suggested that the inability of autotrophy via a reductive tricarboxylic acid cycle may be due to the lack of ATP-dependent citrate lyase. In addition, the genome encodes numerous genes for chemoreceptors, chemotaxis-like systems, and signal transduction machineries. These signalling networks may be linked to this bacterium's versatile energy metabolisms and may provide ecophysiological advantages for D. desulfuricans SSM1 thriving in the physically and chemically fluctuating environments near hydrothermal vents. This is the first genome sequence from the phylum Deferribacteres. PMID:20189949

  13. 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 each emission limit and work practice standard in the following table that applies to your...

  14. 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}

  15. Solar chimney

    International Nuclear Information System (INIS)

    Solar Chimney is an interesting unconventional method for production of electricity from the sun. It consists of a large greenhouse which purpose is to heat the air and create air flow directing it to the base of the chimney and then through the pressure-staged turbine array. Solar Chimney can be used for pick load operation. Australia plans 200 MW solar plant for the and of 2004, which will be the tallest man made structure in the world with a height of almost 1 km and greenhouse diameter reaching 7.5 km. It is a result of Australia's commitment to find alternative energy solutions in order to reduce the environmental impact of fossil and nuclear technologies for electric power production. (Author)

  16. 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... Process Vents, Storage Vessels, Transfer Operations, and Wastewater Pt. 63, Subpt. G, Table 4 Table 4...

  17. 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.

  18. 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.

  19. 40 CFR Table 5 to Subpart Ppp of... - Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process Vents From Batch Unit... Subpart PPP of Part 63—Process Vents From Batch Unit Operations—Monitoring, Recordkeeping, and Reporting... monitor was continuously operating during batch emission episodes selected for control and whether a...

  20. 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.

  1. Geochemistry and mineralogy of a silica chimney from an inactive seafloor hydrothermal field (East Pacific Rise, 18°S)

    OpenAIRE

    Dekov, V.M.; Lalonde, S.V.; Kamenov, G.D.; Bayon, G.; Shanks, W. C.; Fortin, D.; Fouquet, Y.; Moscati, R.J.

    2015-01-01

    An inactive vent field comprised of dead chimneys was discovered on the ultrafast East Pacific Rise (EPR) at 18 degrees S during the research campaign NAUDUR with the R/V Le Nadir in December 1993. One of these chimneys was sampled, studied and found to be largely composed of silica-mineralized bacterial-like filaments. The filaments are inferred to be the result of microbial activity leading to silica (+/- Fe-oxyhydroxide) precipitation. The chimney grew from the most external layer (precipi...

  2. A laboratory and theoretical study of the growth of ``black smoker'' chimneys

    Science.gov (United States)

    Turner, J. S.; Campbell, I. H.

    1987-03-01

    Observational evidence suggests that black smoker chimneys are formed by the precipitation of anhydrite from seawater producing a solid framework which is replaced successively by iron, zinc and copper sulfides. We have demonstrated the feasibility of this process using a laboratory model in which KNO 3 is first crystallized from a warm, nearly saturated solution round an inflowing plume of cold K 2CO 3. The chimney grows in length at a nearly constant rate and, at the same time, it thickens as heat conduction causes further crystallization. The dynamic replacement process has been modelled separately, with CuSO 4 passed through a previously formed chimney of KNO 3 and flowing out through the porous walls when the flow rate, and hence the pressure difference, is increased. The formation of chimneys at a line or slit source has also been investigated in the laboratory. It has been shown that, in this case, the slit is quickly blocked off by crystallization over most of its length and that the growth is concentrated at just a few points to form a small number of nearly axisymmetric chimneys. A theory has been developed which predicts both the diameter of the outlet vent and the sign of the pressure difference between the inside and the outside of an axisymmetric chimney of constant internal diameter for a specified flow rate and density difference. It suggests that changes in flow rate or in the internal diameter of the chimney can cause fluid to flow in or out through the porous wall, leading to changes in the position of mineral stability fields within the evolving chimney. The theory has been extended to describe the pressure distribution in tapering interior conduits and it leads to the conclusion that the direction of flow through a porous chimney can reverse along its length.

  3. 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.

  4. 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.

  5. Reproductive biology, sexual dimorphism, and population structure of the deep sea hydrothermal vent scale-worm, Branchiplynoee seepensis (Polychaeta : Polynoidae)

    OpenAIRE

    Jollivet, D.; Empis, A; Baker, Mc; Hourdez, S; Comtet, Thierry; Jouin-toulmond, C; Desbruyeres, Daniel; Tyler, PA

    2000-01-01

    The polychaete family Polynoidae (scale-worms) is well-represented at deep sea hydrothermal vents. Most species are free-living in a wide range of habitats: from high-temperature hydrothermal `chimney' walls to diffuse venting areas. Conversely, species of the genus Branchipolynoe live inside the mantle cavity of vent and seep mytilids. Specimens, morphologically close to Branchipolynoe seepensis, have been reported from all the known vent areas on the Mid-Atlantic Ridge (MAR), with varying i...

  6. Inclined solar chimney for power production

    International Nuclear Information System (INIS)

    Highlights: → Solar energy harnessing using inclined face of high mountains as solar chimney. → Solar chimneys with structural stability, ease of construction and lower cost. → Mathematical model developed, using complete (mechanical and thermal) energy balance. → Can harness wind power also, as wind velocities at mountain top add to power output. → Air temperature and velocity increase, as air rises in inclined chimney. - Abstract: The present concept of solar chimney is a tall vertical chimney constructed at the center of a large area, which is the collector. This creates questions about stability and economic viability of the chimney and also demands elaborate engineering techniques for constructing a tall chimney. We suggest geometry of 'Inclined Solar Chimney' (ISC), which is constructed along the face of a high rising mountain, on which maximum solar insolation is incident throughout the year. The chimney and the collector get merged here. This makes the structure stable, cost effective and easy for construction. A mathematical model has been developed considering the total energy balance. It predicts the temperature and velocity and kinetic power of the emerging air draft for some chosen values of other parameters. The model also shows the proportion in which absorbed solar energy is divided into different forms, and hence predicts the dependence of kinetic of emerging air draft upon dimensions of the chimney and properties of materials used. Further, it is shown that external winds enhance the kinetic power of the emerging air. Thus ISC can also harness the wind energy, available at the top of the mountain.

  7. 40 CFR Table 3 to Subpart G of... - Process Vents-Monitoring, Recordkeeping, and Reporting Requirements for Complying With 98 Weight...

    Science.gov (United States)

    2010-07-01

    ... combustion device other than a flare) (Continued) Scrubber liquid and gas flow rates 1. Continuous records of scrubber liquid flow rate.2. Record and report the scrubber liquid/gas ratio averaged over the full period... subpart. Scrubber for halogenated vent streams (Note: Controlled by a combustion device other than a...

  8. 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

  9. Seismic modelling of a masonry chimney

    OpenAIRE

    Pallarés Rubio, Francisco Javier; Ivorra Chorro, Salvador

    2007-01-01

    Different plastic/failure are applied to a masonry structure showing the difficulties to deal with masonry material and the results obtained for a masonry chimney under erathquake loading when two different criteria are used.

  10. 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.

  11. 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...

  12. RNA Oligomerization in Laboratory Analogues of Alkaline Hydrothermal Vent Systems.

    Science.gov (United States)

    Burcar, Bradley T; Barge, Laura M; Trail, Dustin; Watson, E Bruce; Russell, Michael J; McGown, Linda B

    2015-07-01

    Discovering pathways leading to long-chain RNA formation under feasible prebiotic conditions is an essential step toward demonstrating the viability of the RNA World hypothesis. Intensive research efforts have provided evidence of RNA oligomerization by using circular ribonucleotides, imidazole-activated ribonucleotides with montmorillonite catalyst, and ribonucleotides in the presence of lipids. Additionally, mineral surfaces such as borates, apatite, and calcite have been shown to catalyze the formation of small organic compounds from inorganic precursors (Cleaves, 2008 ), pointing to possible geological sites for the origins of life. Indeed, the catalytic properties of these particular minerals provide compelling evidence for alkaline hydrothermal vents as a potential site for the origins of life since, at these vents, large metal-rich chimney structures can form that have been shown to be energetically favorable to diverse forms of life. Here, we test the ability of iron- and sulfur-rich chimneys to support RNA oligomerization reactions using imidazole-activated and non-activated ribonucleotides. The chimneys were synthesized in the laboratory in aqueous "ocean" solutions under conditions consistent with current understanding of early Earth. Effects of elemental composition, pH, inclusion of catalytic montmorillonite clay, doping of chimneys with small organic compounds, and in situ ribonucleotide activation on RNA polymerization were investigated. These experiments, under certain conditions, showed successful dimerization by using unmodified ribonucleotides, with the generation of RNA oligomers up to 4 units in length when imidazole-activated ribonucleotides were used instead. Elemental analysis of the chimney precipitates and the reaction solutions showed that most of the metal cations that were determined were preferentially partitioned into the chimneys. PMID:26154881

  13. Apparatus for treating radioactive vent gas

    International Nuclear Information System (INIS)

    Object: To reduce radioactivity contained in gaseous waste discharged from the chimney of an atomic power plant. Structure: An air sponger and liquid level gauge are provided within a radioactive waste liquid tank. Every time the waste liquid flows into said tank air is supplied from a blower through an on-off valve into a sponger to agitate the waste liquid. On the other hand, air is always supplied from a blower to said liquid level gauge. These air streams pass through the waste liquid and flow through a vent duct together with radioactive gas and mist. The vent gas is heated by a heater for reduction of the relative humidity and then led to an active carbon adsorption layer for removing radioactive gas through adsorption, and they are then withdrawn through a surge tank by a blower. (Kamimura, M.)

  14. 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

  15. 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

  16. 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.

  17. Pendulum Dampers for Tall RC Chimney Subjected To Wind

    Directory of Open Access Journals (Sweden)

    Dr. B K Raghu Prasad,

    2014-10-01

    Full Text Available Chimneys are a part of industrial growth in any country. Most current chimney design standards require analysis of dynamic analysis of chimney for earthquake and wind induced loads. Because of variation in dimensions of chimney along its height structural analysis such as wind oscillations have become more critical. If ductility is an important consideration in earthquake resistant design, control of deflection become critical in wind induced vibrations. Pendulum dampers are of the devices to control the deflection. In the present work pendulum dampers of different natural frequencies have been tried. The one which has the largest equivalent logarithmic decrement is found to reduce the response significantly. The response is compared with that of chimney with a tip mass. The paper discusses the dynamic analysis of 150m high RCC chimney subjected to wind. Analysis has been carried out for fixed base case.

  18. 46 CFR 64.63 - Minimum emergency venting capacity.

    Science.gov (United States)

    2010-10-01

    ... AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.63 Minimum emergency venting capacity. (a) The total emergency venting capacity (Q) of the relief devices of an uninsulated MPT must be in accordance with Table 1 or the following formula based upon the pressure...

  19. 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.

  20. Solar Chimney Model Parameters to Enhance Cooling PV Panel Performance

    OpenAIRE

    Mohammed Sh Elden; K. Sopian; Fatah O. Alghoul; Abdelnasser Abouhnik; Ae. Muftah M.

    2013-01-01

    The concept of using the Solar Chimney plays an important role in a wide range of topics to improve cooling system efficiency such as drying process, and single and multi-story buildings ventilation against temperature rising. In this paper, study the effective solar cooling chimney parameter model to enhance the performance of photovoltaic (PV) cooling system. First, a brief description of theoretical performance predictions of the solar cooling chimney also discusses the effect of the ambie...

  1. Moytirra: Discovery of the first known deep-sea hydrothermal vent field on the slow-spreading Mid-Atlantic Ridge north of the Azores

    Science.gov (United States)

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

    2013-10-01

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

  2. 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).

  3. 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

  4. Simulation of a sloped solar chimney power plant in Lanzhou

    International Nuclear Information System (INIS)

    Research highlights: → A sloped solar chimney power plant in Lanzhou, China is investigated. → The configuration sizes are designed separately. → The system has high periodicity and stability but low efficiency. → The sloped solar chimney power system is of high value for Northwest China. -- Abstract: Solar chimney power system is one large-scale utilization style of solar energy, which has drawn high attentions worldwide. Though scholars all over the world have made many researches on the solar chimney power system, reports of sloped solar chimney power system are still few. A sloped solar chimney power plant, which is expected to provide electric power for remote villages in Northwest China, has been designed for Lanzhou City in this paper. The designed plant, in which the height and radius of the chimney are 252.2 m and 14 m respectively, the radius and angle of the solar collector are 607.2 m and 31o respectively, is designed to produce 5 MW electric power on a monthly average all year. The performances, such as the airflow temperature increase, pressure, the airflow speed, system efficiency and solar collector efficiency, of the built sloped solar chimney power plant are simulated and presented. Simulation results show that parameters of the sloped solar chimney power plant are symmetrical and stable; the power plant has better performances in spring and autumn days; the overall efficiency of the power plant is low. Considering the abundant solar radiation, environmental friendliness, easy management and low population density, the sloped solar chimney power system is of high value to Northwest China.

  5. Shallow submarine hydrothermal activity with significant contribution of magmatic water producing talc chimneys in the Wakamiko Crater of Kagoshima Bay, southern Kyushu, Japan

    Science.gov (United States)

    Yamanaka, Toshiro; Maeto, Kotaro; Akashi, Hironori; Ishibashi, Jun-Ichiro; Miyoshi, Youko; Okamura, Kei; Noguchi, Takuroh; Kuwahara, Yoshihiro; Toki, Tomohiro; Tsunogai, Urumu; Ura, Tamaki; Nakatani, Takeshi; Maki, Toshihiro; Kubokawa, Kaoru; Chiba, Hitoshi

    2013-05-01

    Active hydrothermal venting from shallow seafloor (200-m depth) with talc chimneys has been discovered at the Wakamiko Crater floor in the Aira Caldera, southern Kyushu, Japan. The major chemical composition of the fluids suggests that the fluids are supplied from a single reservoir. The fluid is characterized by a low chloride concentration, low δD value, and a high δ18O value, suggesting that the endmember hydrothermal fluid is a mixture of seawater and andesitic water and possibly contribution of meteoric water and/or phase separation. Such noticeable magmatic input may be supported by high helium isotopic ratio (6.77 RA) of fumarolic gas discharging from the crater. Silica and alkaline geothermometers indicate that the fluid-rock interaction in the reservoir occurs in the temperature range of 230 to 250 °C. The high alkalinity and high ammonium and dissolved organic matter concentrations in the fluid indicate interaction of the fluid with organic matter in sedimentary layers. At least three hydrothermal vents have been observed in the crater. Two of these have similar cone-shaped chimneys. The chimneys have a unique mineralogy and consist dominantly of talc (kerolite and hydrated talc) with lesser amounts of carbonate (dolomite and magnesite), anhydrite, amorphous silica, and stibnite. The precipitation temperature estimated from δ18O values of talc was almost consistent with the observed fluid temperature. Geochemical modeling calculations also support the formation of talc and carbonate upon mixing of the endmember hydrothermal fluid with seawater and suggest that the talc chimneys are currently growing from venting fluid.

  6. 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).

  7. 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

  8. First sighting of active fluid venting in the Gulf of Cadiz

    OpenAIRE

    Van Rooij, D.; Depreiter, D.; Bouimetarhan, I.; De Boever, E.; De Rycker, K.; Foubert, A.; Huvenne, V; Reveillaud, J.; Staelens, P.; Vercruysse, J.; Versteeg, W.; Henriet, J.-P.

    2005-01-01

    The Mercator mud volcano, located in the Gulf of Cadiz off the coasts of Spain, Portugal, and Morocco (Figure 1), may provide an accessible field laboratory for studying local active venting and its possible internal and external controls. The recent discovery of the first active deep ocean ‘brown smoker’ chimney in this area can possibly be linked with the disintegration of a gas hydrate layer between the seafloor and a subsurface level that is dependent on pressure and temperature. For more...

  9. A new picture of interstellar medium: chimney model

    International Nuclear Information System (INIS)

    Many observational facts which indicate a different picture of the interstellar medium from the McKee-Ostriker's three-phase model are accumulated in this decade. Based upon the sequential star formation model in molecular clouds the gigantic superbubbles are formed by sequential supernova explosions. Such superbubbles stand perpendicular to the disk like chimneys and the hot gas can go up to the halo like smoke in chimneys. About one thousand of chimneys smoke in a galaxy along, the spiral arms. At the interarm region the classical two-phase model is preferable. Here, several observational evidences for this picture are presented, and some implications to the evolution of galaxies are discussed

  10. 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.

  11. 24 CFR 3280.611 - Vents and venting.

    Science.gov (United States)

    2010-04-01

    ... DEVELOPMENT MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS Plumbing Systems § 3280.611 Vents and venting... required by structural conditions, vent piping may offset below the rim of the fixture at the maximum...

  12. A simple theoretical model of a solar chimney

    International Nuclear Information System (INIS)

    A simple theoretical model of a solar chimney to predict its performance under varying ambient and geometrical features was proposed. Steady state heat transfer equations were set up using a thermal resistance network and solved using matrix inversion. Surface temperatures of the heat absorbing wall and glass and induced air flow velocity in the chimney are predicted. An experiment model 2 m high x 0.45 m wide with air channel gaps of 0.1, to 0.3 m wide was constructed. Outdoor tests were performed by exposure to both direct and diffuse solar radiation. The effects of air channel gap and solar radiation intensity were investigated. Air velocities between 0.25 to 0.39 ms-1 at radiation intensities up to 650 W m-2 were obtained. No reserve air circulation was observed at the chimney exit. The model was found more suitable for solar chimney with large air gaps

  13. 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...

  14. 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.

  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. Experimental Investigations on Performance and Design Parameters of Solar Chimney

    Directory of Open Access Journals (Sweden)

    İbrahim ÜÇGÜL

    2010-03-01

    Full Text Available 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. Then, this model constituted the basis for developed computer programme and performance parameters of the system are obtained. The obtained findings showed that the solar chimney, which is suitable for climate conditions of Isparta and its surroundings, are sufficient for determining design and performance parameters. The results showed that electricity generation with solar chimney is suitable for areas which have high solar incident and long sunshine duration and similar climate conditions as such as Isparta and its surroundings. When the results are evaluated, it is seen that electricity generation power of solar chimney depends on the region solar data, the chimney height and the size of greenhouse area.

  17. 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

  18. A Retrievable Mineral Microcosm for Examining Microbial Colonization and Mineral Precipitation at Seafloor Hydrothermal Vents

    Science.gov (United States)

    Dunn, E. E.; Holloway, J. R.; Cary, S.; Voglesonger, K. M.; Ashbridge, D. A.; O'Day, P. A.

    2002-12-01

    Although seafloor hydrothermal vent environments are known to support thriving ecosystems, the microscale physical and chemical environment suitable for microbial colonization and the identity of pioneering organisms is unknown. Because of the fragility of young chimneys and their ephemeral nature, novel methods for sample retrieval and analysis are required. The mineral microcosm consists of four titanium mesh chambers containing crushed minerals mounted on a titanium base that allows for fluid flow through the chambers. The chambers can be filled with different minerals or mineral mixtures (or no minerals) to supply different substrates for microbial colonization and different local microenvironments as minerals react with the surrounding fluids. The device sets on top of an active hydrothermal vent for a period of days to weeks to allow colonization and mineral reaction. The mineral microcosm was deployed during the Atlantis/Alvin Extreme 2001 Cruise (Oct.- Nov.,2001) to 9° 50'N on the East Pacific Rise a total of three times, for ~ 24, ~ 96, and ~ 48 hours each. It was deployed in two different environments, twice in lower temperature (350°C).Seed minerals included sulfides, sulfates, magnetite, apatite, and quartz, both individually and in mixtures. In the first 24-hour deployment, dissolution of anhydrite but not sulfide minerals within the chambers indicated high temperatures in chamber interiors and rapid reaction rates. Temperatures measured on chamber exteriors before retrieval ranged from 4° -98°C. The 96-hour deployment on a hot vent (fluid ~370°C before deployment) resulted in extensive mineral precipitation and chimney growth inside the mineral chambers, on the outer surfaces of the chambers, and on the platform as a whole, creating micro-chimneys several centimeters tall. The young chimneys were mainly composed of pyrite with lesser amounts of chalcopyrite and sphalerite and with thin veneers of anhydrite on exterior surfaces in contact with

  19. 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 ...

  20. 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

  1. Discovery of new hydrothermal vent sites in Bransfield Strait, Antarctica

    Science.gov (United States)

    Klinkhammer, G. P.; Chin, C. S.; Keller, R. A.; Dählmann, A.; Sahling, H.; Sarthou, G.; Petersen, S.; Smith, F.; Wilson, C.

    2001-12-01

    We carried out a search for hydrothermal vents in the Central Basin of Bransfield Strait, Antarctica. The ZAPS (zero angle photon spectrometer) chemical sensor and instrument package (Oregon State University), OFOS (ocean-floor observation system) camera sled and TVG (TV-grab) (GEOMAR) were used to explore the water column and underlying seafloor. These operations were supplemented with a series of dredges. Hydrothermal plumes over Hook Ridge at the eastern end of the basin are confined to the E ridge crest and SE flank. The plumes are complex and sometimes contain two turbidity maxima one widespread feature centered at 1150 m and a smaller, more localized but broad maximum at 600-800 m. We traced the source of the shallower plume to a sunken crater near the ridge crest using sensors on the ZAPS instrument package. Subsequently two TV-grabs from the crater brought back hot, soupy sediment (42-49°C) overlain by hard, siliceous crusts and underlain by a thick layer of volcanic ash. We also recovered chimney fragments whose texture and mineralogy indicate venting temperatures in excess of 250°C. Native sulfur and Fe-sulfides occur in fractures and porous layers in sediment from throughout the area. Pore water data from the crater site are consistent with venting into a thin sediment layer and indicate phase separation of fluids beneath Hook Ridge. The source of the deeper plumes at Hook Ridge has yet to be located. We also explored a series of three parallel volcanic ridges west of Hook Ridge called Three Sisters. We detected water column anomalies indicative of venting with the ZAPS package and recovered hydrothermal barites and sulfides from Middle Sister. We spent considerable time photographing Middle Sister and Hook Ridge but did not identify classic vent fauna at either location. We either missed small areas with our photography or typical MOR vent fauna are absent at these sites.

  2. 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)

  3. The gas chimney formation during the steam explosion premixing phase

    International Nuclear Information System (INIS)

    The crucial part in isothermal premixing experiment simulation is the correct prediction of the gas chimney, which forms when the spheres penetrate into water. The first simulation results with the developed original combined multiphase model showed that the gas chimney starts to close at the wrong place at the top of the chimney and not in the middle, like it was observed in the experiments. To find the physical explanation for this identified weakness of our numerical model a comprehensive parametric analysis (mesh size, initial water-air surface thickness, water density, momentum coupling starting position) has been performed. It was established that the reason for the unphysical gas chimney closing at the top could be the gradual air-water density transition in the experiment model, since there is due to the finite differences description always a transition layer with intermediate phases density over the pure water phase. It was shown that this difference between our numerical model and the experiment can be somewhat compensated if the spheres interfacial drag coefficient at the upmost mesh plane of the unphysical air-water transition layer is artificially risen. On this way a more correct gas chimney formation can be obtained.(author)

  4. 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)

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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)

  10. 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

  11. 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.

  12. Experimental and numerical investigation on an innovative solar chimney

    International Nuclear Information System (INIS)

    Highlights: • Intensifiers were applied to increase heat flux. • Numerical and experimental data were compered. • We investigated the rotational pattern of the air inside the SC. • This chimney is equipped with a container, placed exactly beneath the collector. - Abstract: A novel small scale model of solar chimney was investigated experimentally and numerically. Air flow, heat transfer and flow characteristics were numerically calculated and compared with the experimental results in this paper. Two intensifiers were used to intensify the heat flux radiated by the sun all around the solar chimney in the experimental case. An air tank was located downside the system to increase the absorption of the solar radiation reflected by the intensifiers. RNG k–ε model was chosen to simulate the turbulence and the well-known SIMPLE algorithm was used to solve the coupled velocity and pressure equations. Results show that utilization of intensifiers caused an increase in velocity magnitude in the chimney and consequently more power was generated. The maximum velocity of 5.12 m/s was reached which is remarkable, considering the small size of the SC structure

  13. A NUMERICAL study of solar chimney power plants in Tunisia

    Science.gov (United States)

    Bahar F, Attig; S, Guellouz M.; M, Sahraoui; S, Kaddeche

    2015-04-01

    A 3D CFD (Computational fluid dynamics) model of a Solar Chimney Power Plant (SCPP) was developed and validated through comparison with the experimental data of the Manzanares plant. Then, it was employed to study the SCPP performance for locations throughout Tunisia.

  14. 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.

  15. 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.

  16. 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

  17. 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

  18. 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

  19. Vente directe et terroir

    OpenAIRE

    Delfosse, Claire; Bernard, Cécile

    2009-01-01

    Si, dans la relation de proximité qu’établit la vente directe, il semble qu’il ne soit pas nécessaire de revendiquer le lien au terroir, il apparaît qu’aujourd’hui les nouvelles formes de vente directe et les formes « traditionnelles » renouvelées le font de plus en plus. Cela peut prendre différentes formes : revendication de la proximité, de la provenance « campagne », voire création de marques collectives faisant référence à un terroir ou un pays… Il s’agira donc dans cette communication d...

  20. Simulation and optimization of geometric parameters of a solar chimney in Tehran

    International Nuclear Information System (INIS)

    Highlights: • A fundamental mathematical of solar chimney model was described. • The performance of solar chimney power plant was analytically simulated. • The results of predictions were compared with the experimental data. • The velocity magnitude can be raised 4–25% in different cases. - Abstract: An analytical and numerical study for geometrical optimizing of a solar chimney prototype at University of Tehran was performed. A fundamental mathematical model that describes the flow was presented, and the performance evaluation of solar chimney was simulated with operational and geometric configurations. The numerical predictions were validated through comparison with the experimental data of the solar chimney pilot which was constructed in height of 2 m and collector radius of 3 m. The results show that, the collector inlet of 6 cm, the chimney height of 3 m, and the chimney diameter of 10 cm were the best alternatives for the constructed solar chimney pilot. It is found that the velocity magnitude can be raised to 4–25% in different cases; also the analysis indicated that the height and diameter of the chimney are the most important physical variables for solar chimney design

  1. Numerical Study of a Solar Chimney Power Plant

    Directory of Open Access Journals (Sweden)

    A. Dhahri

    2014-11-01

    Full Text Available The aim of this study is to present a numerical analysis on the performance of a solar chimney power plant using steady state Navier-Stokes and energy equations in cylindrical coordinate system. The fluid flow inside the chimney is assumed to be turbulent and simulated with the k-ε turbulent model, using the FLUENT software package. Numerical simulations were performed using the Spanish prototype as reference. The computed results are in good agreement with experimental measurements of Manzanares power plant. Besides, a theoretical model was proposed taking into account the kinetic energy difference within the solar collector. The effects of the main geometrical parameters of the collector and the solar radiation intensity on the air mass flow rate and the temperature rise in the collector have been investigated. The fluid and ground temperature distributions were also presented and analyzed.

  2. 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.

  3. GPS FOM Chimney Analysis using Generalized Extreme Value Distribution

    Science.gov (United States)

    Ott, Rick; Frisbee, Joe; Saha, Kanan

    2004-01-01

    Many a time an objective of a statistical analysis is to estimate a limit value like 3-sigma 95% confidence upper limit from a data sample. The generalized Extreme Value Distribution method can be profitably employed in many situations for such an estimate. . .. It is well known that according to the Central Limit theorem the mean value of a large data set is normally distributed irrespective of the distribution of the data from which the mean value is derived. In a somewhat similar fashion it is observed that many times the extreme value of a data set has a distribution that can be formulated with a Generalized Distribution. In space shuttle entry with 3-string GPS navigation the Figure Of Merit (FOM) value gives a measure of GPS navigated state accuracy. A GPS navigated state with FOM of 6 or higher is deemed unacceptable and is said to form a FOM 6 or higher chimney. A FOM chimney is a period of time during which the FOM value stays higher than 5. A longer period of FOM of value 6 or higher causes navigated state to accumulate more error for a lack of state update. For an acceptable landing it is imperative that the state error remains low and hence at low altitude during entry GPS data of FOM greater than 5 must not last more than 138 seconds. I To test the GPS performAnce many entry test cases were simulated at the Avionics Development Laboratory. Only high value FoM chimneys are consequential. The extreme value statistical technique is applied to analyze high value FOM chimneys. The Maximum likelihood method is used to determine parameters that characterize the GEV distribution, and then the limit value statistics are estimated.

  4. D0 - Chimney Lead Quench Detection, Beta Solenoid

    International Nuclear Information System (INIS)

    The voltage drop across the superconducting chimney lead is sensed to detect a quench. The return sense lead is mounted outside the chimney. The return sense lead and the superconducting chimney wire form a loop with area A ∼ 1.7 m2 (information from R. Ru. cinski). Changing flux through area A will induce a voltage in the sense loop and could cause false quench detection. Assume that the field through A changes 1 kGauss (0.1 Wb/m2) in 10-3 sec. The induced voltage is then: e = d0/dt = dBA/dt and e = 0.1 x 1.7/10-3 = 170 V. This is probably a very pessimistic estimate, but it shows that we have to watch out. Changes of 100 Gauss in 100 msec (CDF experience?) are probably more likely and cause: e = 0.01 x 1.7/10-2 ∼ 1.7 V noise. This noise is still too high because trip levels are planned to sit at ∼50 mV? It is practically impossible to predict what the real noise values would be, but I expect them to be in the order of 1 to 10 V. This is more than we can handle and I would expect nuisance trips.

  5. Piping systems, containment pre-stressing and steel ventilation chimney

    International Nuclear Information System (INIS)

    Units 5 and 6 of NPP Kozloduy have been designed initially for seismic levels which are considered too low today. In the frame of an IAEA Coordinated Research Programme, a Swiss team has been commissioned by Natsionalna Elektricheska Kompania, Sofia, to analyse the relevant piping system, the containment prestressing and the steel ventilation chimney and to recommend upgrade measures for adequate seismic capacity where applicable. Seismic input had been specified by and agreed upon earlier by IAEA experts. The necessary investigations have been performed in 1995 and discussed with internationally recognized experts. The main results may be summarized as follows: Upgrades are necessary at different piping sy ports (additional snubbers or viscous dampers). These fixes can be done easily at low cost. The containment prestressing tendons are adequately designed for the specified load combinations. However, unfavourable construction features endanger the reliability. It is therefore strongly recommended to replace the tendons stepwise and to upgrade the existing monitoring system. Finally, the steel ventilation chimney may not withstand a seismic event, however the containment and diesel generator building will not be destroyed at possible impact by the chimney. On the other hand the roof of the main building has to be reinforced partially. It is recommended to continue the project for 1996 and 1997 to implement the upgrade measures mentioned above, to analyse the remaining piping systems and to consolidate all results obtained by different research groups of the IAEA programme with respect to piping systems including components and tanks

  6. Power generation from wind turbines in a solar chimney

    Directory of Open Access Journals (Sweden)

    Tudor Foote, Ramesh K. Agarwal

    2013-01-01

    Full Text Available 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 k – ε 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.

  7. 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.

  8. 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.

  9. 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

  10. Seismic decoupling of an explosion centered in a granite chimney rubble -- scaled experiment results. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Keller, C. [Science & Engineering Associates, Inc., Santa Fe, NM (United States); Miller, S.; Florence, A.; Fogle, M.; Kilb, D.

    1991-12-01

    This report describes the small scale evaluation of the feasibility of significant decoupling by siting an explosion in granite rubble. The chimney characteristics scaled to laboratory dimensions were those of the PILE DRIVER event. The scaled charges were of 1 KT and 8KT in the PILE DRIVER chimney. The measure of the effect was the velocity field history in the granite outside the chimney volume with the chimney rubble and with no rubble. A number of chimney sizes and shapes were studied. The explosion process was modeled via two-din=mensional, finite-difference methods used for prediction of velocity histories at the Nevada Test Site. The result was that both the spectral shape and the magnitude of the transmitted shock wave were drastically altered. The chimney geometry was as important as the rubble characteristics.

  11. EXPERIMENTAL ANALYSIS OF A VELOCITY FIELD USING VARIABLE CHIMNEY DIAMETER FOR SOLAR UPDRAFT TOWER

    Directory of Open Access Journals (Sweden)

    Neeraj Mehla,

    2011-04-01

    Full Text Available A solar updraft tower consists of an air collector 1.4 m in diameter and 80 cm tall chimney was set upin NIT Hamirpur, Himachal-Pradesh, India. The objective of the study was to investigate the variation of velocity with essential geometricparameter of the system. The solar updraft tower system consists of three essential elements- collector, chimney height and wind turbine. The output power of a system is depended on the input velocity to the wind turbine. Turbine inlet velocity (V is the function of five parameter of the solar updraft tower systems such as collector diameter (Dc, roof glass angle (β, entrance height (h, tower's height (Ht, tower's diameter (D, out of which variable roof angle and the chimney height is analysis. It was found that the solar chimney diameter of 8 cm is having the maximum velocity for the constructed setup, and the ratio of chimney diameter to chimney heightwas found to be 0.1.

  12. 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.

  13. 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...

  14. 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

  15. Natural convection enhancement in an asymmetrically heated channel-chimney system

    International Nuclear Information System (INIS)

    In this paper, a numerical study is performed in order to analyze the effect of adding a chimney to a vertical open channel. The channel is heated asymmetrically at uniform heat flux while the chimney is symmetric and wider than the channel. The thermal and dynamic aspects of the channel-chimney system (T chimney) are studied by varying the width and the height of the chimney while the aspect ratio of the channel is kept fixed. The main objective of this work is to determine the optimal geometric parameters of the chimney: the expansion ratio B (chimney width normalized by the channel width) and the extension ratio Er (chimney height normalized by the channel height), that maximize the mass flow rate (G) and the average Nusselt number (Nua). More than four hundred numerical simulations have been carried out at modified Rayleigh numbers ranging from 102 to 5x104 (laminar regime). The computations allowed the identification of three types of system responses. The flow structure and the pressure field were also analyzed to elucidate why the increase of the chimney width can improve or deteriorate the mass flow rate and the heat transfer. Finally, appropriate correlations have been proposed for determining the optimal configurations and the corresponding enhancement of the mass flow rate and the heat transfer coefficient. (authors)

  16. 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

  17. 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.

  18. Solar chimney power generation project - The case for Botswana

    International Nuclear Information System (INIS)

    Import of a huge proportion of electrical energy from the Southern African Power Pool, and the geographical location and population distribution of Botswana stimulated the need to consider renewable energy as an alternative to imported power. The paper describes a systematic experimental study on a mini-solar chimney system. Particular attention is given to measurements of air velocity, temperature and solar radiation. The results for the selected 5 and 6 clear days of October and November, respectively, are presented. These results enable the relationship between average insolation, temperature difference and velocity for selected clear days to be discussed. (author)

  19. 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.

  20. 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.

  1. 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.

  2. 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

    2016-02-01

    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.

  3. 29 CFR 1926.854 - Removal of walls, masonry sections, and chimneys.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 8 2010-07-01 2010-07-01 false Removal of walls, masonry sections, and chimneys. 1926.854....854 Removal of walls, masonry sections, and chimneys. (a) Masonry walls, or other sections of masonry... steel framing may be left in place during the demolition of masonry. Where this is done, all steel...

  4. Thermal management of a symmetrically heated channel-chimney system

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, A. [Universita degli Studi di Napoli Federico II, Dipt. di Energetica, Termofluidodinamica applicata e Condizionamenti ambientali, Napoli (Italy); Buonomo, B.; Manca, O. [Seconda Universita degli Studi di Napoli, Dipt. di Ingegneria Aerospaziale e Meccanica, (CE) (Italy)

    2009-03-15

    A parametric analysis of natural convection in air, in a channel-chimney system, symmetrically heated at uniform heat flux, obtained by means of a numerical simulation, is carried out. The analyzed regime is two-dimensional, laminar and steady-state. Results are presented in terms of wall temperature profiles in order to show the more thermally convenient configurations which correspond to the channel-chimney system with the lowest maximum wall temperature. For the considered Rayleigh number, the difference between the highest and the lowest maximum wall temperatures increases with increasing the channel aspect ratio. The optimal expansion ratio values depend strongly on the Rayleigh number and extension ratio values and slightly on the channel aspect ratio. Correlations for dimensionless mass flow rate, maximum wall temperature and average Nusselt number, in terms of Rayleigh number and dimensionless geometric parameters are presented in the ranges: 5{<=}Ra{sup *}{<=}2.0 x 10{sup 4}, 1.5{<=}L/L{sub h}{<=}4.0 and 1.0{<=}B/b{<=}4.0. (authors)

  5. Thermal management of a symmetrically heated channel-chimney system

    International Nuclear Information System (INIS)

    A parametric analysis of natural convection in air, in a channel-chimney system, symmetrically heated at uniform heat flux, obtained by means of a numerical simulation, is carried out. The analyzed regime is two-dimensional, laminar and steady-state. Results are presented in terms of wall temperature profiles in order to show the more thermally convenient configurations which correspond to the channel-chimney system with the lowest maximum wall temperature. For the considered Rayleigh number, the difference between the highest and the lowest maximum wall temperatures increases with increasing the channel aspect ratio. The optimal expansion ratio values depend strongly on the Rayleigh number and extension ratio values and slightly on the channel aspect ratio. Correlations for dimensionless mass flow rate, maximum wall temperature and average Nusselt number, in terms of Rayleigh number and dimensionless geometric parameters are presented in the ranges: 5≤Ra*≤2.0 x 104, 1.5≤L/Lh≤4.0 and 1.0≤B/b≤4.0. (authors)

  6. Parameterization Studies of Solar Chimneys in the Tropics

    Directory of Open Access Journals (Sweden)

    Alex Yong Kwang Tan

    2013-01-01

    Full Text Available The paper examines the effect of the solar chimney’s stack height, depth, width and inlet position on the interior performance (air temperature and speed at 1.20 m height above the ground as well as proposes an optimal tropical solar chimney design. Simulations show that the output air temperature remains constant while the solar chimney’s width is the most significant factor influencing output air speed. The solar chimney’s inlet position has limited influence on the output air speed although regions near the solar chimney’s inlet show an increase in air speed. Furthermore, a regression model is developed based on the solar chimney’s stack height, depth and width to predict the interior air speed. To optimize solar chimney in the tropics, the recommendation is to first maximize its width as the interior’s width, while allowing its stack height to be the building’s height. Lastly, the solar chimney’s depth is determined from the regression model by allocating the required interior air speed.

  7. Experimental study of temperature field in a solar chimney power setup

    International Nuclear Information System (INIS)

    A pilot experimental solar chimney power setup consisted of an air collector 10 m in diameter and an 8 m tall chimney has been built. The temperature distribution in the solar chimney power setup was measured. Temperature difference between the collector outlet and the ambient usually can reach 24.1 deg. C, which generates the driving force of airflow in the setup. This is the greenhouse effect produced in the solar collector. It is found that air temperature inversion appears in the latter chimney after sunrise both on a cool day and on a warm day. Air temperature inversion is formed by the increase of solar radiation from the minimum and clears up some time later when the absorber bed is heated to an enough high temperature to make airflow break through the temperature inversion layer and flow through the chimney outlet

  8. Experimental study of temperature field in a solar chimney power setup

    International Nuclear Information System (INIS)

    A pilot experimental solar chimney power setup consisted of an air collector 10 m in diameter and an 8 m tall chimney has been built. The temperature distribution in the solar chimney power setup was measured. Temperature difference between the collector outlet and the ambient usually can reach 24.1 C, which generates the driving force of airflow in the setup. This is the greenhouse effect produced in the solar collector. It is found that air temperature inversion appears in the latter chimney after sunrise both on a cool day and on a warm day. Air temperature inversion is formed by the increase of solar radiation from the minimum and clears up some time later when the absorber bed is heated to an enough high temperature to make airflow break through the temperature inversion layer and flow through the chimney outlet. (author)

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

    International Nuclear Information System (INIS)

    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

  10. 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.

  11. 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

  12. 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

  13. 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...

  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. 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.

  16. 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)

  17. Visual Observations and Geologic Settings of the Newly-Discovered Black Smoker Vent Sites Across the Galapagos Ridge-Hotspot Intersection

    Science.gov (United States)

    Anderson, P.; Haymon, R.; MacDonald, K.; White, S.

    2006-12-01

    Nearly one-fifth of the global mid-ocean ridge is hotspot-affected, yet very little is known about how hotspots affect quantity and distribution of high-temperature hydrothermal vents along the ridge. During the 2005-06 GalAPAGoS expedition, acoustic and plume sensor surveys were conducted across the Galapagos ridge- hotspot intersection, lon. 94.5ºW- lon. 89.5ºW, to map fine scale geologic features and locate hydrothermal plumes emanating from the ridge crest. Where significant plumes were detected, the Medea fiber-optic camera sled was used successfully to find and image high-temperature vents on the seafloor. With Medea we discovered and imaged the first active and recently extinct black smokers known along the entire Galapagos Spreading Center (GSC), and documented the geologic setting of these vents. The Medea survey imaged numerous inactive vents as well as 3 active high-temperature vent fields along the ridge at 94º 04.5'W (Navidad Site), 91º56.2'W (Iguanas Site) and 91º54.3'W (Pinguinos Site). Two recently extinct vent fields also were identified at 91º23.4'-23.7'W and 91º13.8'W. All of the high-temperature vent sites that we identified along the GSC are found above relatively shallow AMC reflectors and are located in the middle 20% of ridge segments. Without exception the vent sites are located along fissures atop constructional axial volcanic ridges (AVR's) composed of relatively young pillow basalts. In some cases, the vents were associated with collapses adjacent to the fissures. The fissures appear to be eruptive sources of the pillow lavas comprising the AVR's. Video images of the chimneys show mature, cylindrical structures, up to 14m high; little diffuse flow; few animals; and some worm casts and dead clam shells, suggesting prior habitation. We conclude that distribution of the vents is controlled by magmatic processes, (i.e., by locations of shallow AMC magma reservoirs and eruptive fissures above dike intrusions), and that there is

  18. 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.

  19. 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

  20. Numerical investigation on thermal and fluid dynamic behaviors of solar chimney building systems

    International Nuclear Information System (INIS)

    Full text: Buildings as big energy-consuming systems require large amount of energy to operate. Globally, buildings are responsible for approximately 40% of total world annual energy consumption. Sustainable buildings with renewable energy systems are trying to operate independently without consumption of conventional resources. Renewable energy is a significant approach to reduce resource consumption in sustainable building. A solar chimney is essentially divided into two parts, one - the solar air heater (collector) and second - the chimney. Two configurations of solar chimney are usually used: vertical solar chimney with vertical absorber geometry, and roof solar chimney. For vertical solar chimney, vertical glass is used to gain solar heat. Designing a solar chimney includes height, width and depth of cavity, type of glazing, type of absorber, and inclusion of insulation or thermal mass. Besides these system parameters, other factors such as the location, climate, and orientation can also affect its performance. In this paper a numerical investigation on a prototypal solar chimney system integrated in a south facade of a building is presented. The analysis is carried out on a three-dimensional model in air flow and the governing equations are given in terms of k-s turbulence model. Two geometrical configurations are investigated: 1) a channel with vertical parallel walls and 2) a channel with principal walls one vertical and the other inclined. The problem is solved by means of the commercial code Ansys-Fluent and the results are performed for a uniform wall heat flux on the vertical wall is equal to 300 and 600 W/m2. Results are given in terms of wall temperature distributions, air velocity and temperature fields and transversal profiles in order to evaluate the differences between the two base configurations and thermal and fluid dynamic behaviors. Further, the ground effect on thermal performances is examined. key words: mathematical modeling, solar chimney

  1. Numerical simulation of an innovated building cooling system with combination of solar chimney and water spraying system

    Science.gov (United States)

    Rabani, Ramin; Faghih, Ahmadreza K.; Rabani, Mehrdad; Rabani, Mehran

    2014-05-01

    In this study, passive cooling of a room using a solar chimney and water spraying system in the room inlet vents is simulated numerically in Yazd, Iran (a hot and arid city with very high solar radiation). The performance of this system has been investigated for the warmest day of the year (5 August) which depends on the variation of some parameters such as water flow rate, solar heat flux, and inlet air temperature. In order to get the best performance of the system for maximum air change and also absorb the highest solar heat flux by the absorber in the warmest time of the day, different directions (West, East, North and South) have been studied and the West direction has been selected as the best direction. The minimum amount of water used in spraying system to set the inside air averaged relative humidity <65 % is obtained using trial and error method. The simulation results show that this proposed system decreases the averaged air temperature in the middle of the room by 9-14 °C and increases the room relative humidity about 28-45 %.

  2. 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.

  3. Cloud Formation in the Plumes of Solar Chimney Power Generation Facilities: A Modeling Study

    Science.gov (United States)

    Vanreken, T. M.; Nenes, A.

    2006-12-01

    The mounting negative impacts of our dependence on fossil fuels make obvious the need for continued development of alternative power generation technologies. One promising technology is the solar chimney power plant, the concept of which is straightforward and consists of three main components: a solar air collector, the chimney itself, and a power turbine. The solar collector is a large, circular, greenhouse-like structure that gently slopes toward its center; air enters at the outer edge, and as the air parcel warms buoyancy causes it to move upward and toward the center of the collector. When the air has reached the center of the collector, its temperature has increased by an amount ΔT, at which point it enters the chimney. The chimney functions as the main thermal engine in the power plant; the available power for electrical conversion is a function of the maximum potential air velocity through the chimney, which depends primarily on its height and on ΔT. The actual air velocity is determined by the efficiency of the turbine, which is placed between the solar collector and the chimney. A pilot-scale solar chimney power plant has operated in Manzanares, Spain for two decades, and larger facilities have been proposed in China and Australia. As with all new technologies, it is important to consider the potential adverse impacts of solar chimney power generation facilities. This study considers one such impact- the potential for water vapor in solar chimney plumes to affect both the performance of the facility and the local meteorology. Using a cloud parcel model, the progress of a plume up through and out of a solar chimney was simulated for a range of conditions consistent with the proposed Australian facility. As might be expected, in the absence of any water vapor enhancement the plume demonstrated minimal cloud forming potential. However, our results indicate that in cases of moderate water vapor enhancement, cloud formation can occur after the plume exits

  4. Design and measured performance of a solar chimney for natural-circulation solar-energy dryers

    International Nuclear Information System (INIS)

    The design and construction of a solar chimney which was undertaken as part of a study on natural-circulation solar-energy dryers is reported. The experimental solar chimney consists of a 5.3m high and 1.64m diameter cylindrical polyethylene-clad vertical chamber, supported structurally by steel framework and draped internally with a selectively-absorbing surface. The performance of the chimney which was monitored extensively with and without the selective surface in place (to study the effectiveness of this design option) is also reported. (author). 14 refs, 7 figs

  5. Fluid flow rate, temperature and heat flux at Mohns Ridge vent fields: evidence from isosampler measurements for phase separated hydrothermal circulation along the arctic ridge system

    Science.gov (United States)

    Schultz, A.; Pedersen, R. B.; Thorseth, I. H.; Taylor, P.; Flynn, M.

    2005-12-01

    An expedition to the Mohns Ridge in the Norwegian-Greenland sea was carried out in July-August 2005 as part of BIODEEP, lead by University of Bergen (UoB). UoB had previously detected water column methane along this very slow spreading ridge. Previous ROV observations along the ridge (71 deg 18'N, 5 deg 47'W, 605 mbsl) near Jan Mayen had uncovered a broad area of ferric hydroxide-rich bacterial/mineral assemblages, comprising large populations of gallionella bacteria. This area was revisted in 2005. Characteristic of sections of this area ("Gallionella Garden") are chimney-like structures standing ~15 cm tall, often topped by a sea lily (heliometra glacialis). The interior of the structures comprised quasi-concentric bands with vertically-oriented channels. The Oregon State University/Cardiff University Isosampler sensor determined that some of these assemblages support fluid flow through their interior. The outflow from the chimney structures was typically +0.5 deg C, against background temperatures of -0.3 deg C. Flow anomalies were also identified atop extensive bacterial mats. Gallionella Gardens is several km in extent with active, albeit extremely low temperature hydrothermal flow. A field of active high temperature smoker chimney structures was located near Gallionella Garden at 540 mbsl. This field extends ~500 m along a scarp wall, with hydrothermal mounds extending along faults running perpendicular to the scarp, each of which has multiple smoker vents and areas of diffuse flow. There was evidence for phase separation, with a negatively buoyant fluid phase exiting some vent orifices and descending along the vent wall; and evidence for gas phase condensing after leaving some vent orifices. Gas bubble emissions were not uncommon. Isosampler sensors were available that were configured for lower temperature measurements at Gallionella Garden. While capable of detecting variations in effluent at the 4 millidegree level, the temperature ceiling for the sensor

  6. 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.)

  7. 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.

  8. Dynamic characteristic and seismic response analyses for installation of in-chimney bracket structures in HANARO

    International Nuclear Information System (INIS)

    The in-chimney bracket structures will be installed on the upper part of chimney, which holds the capsule extension pipes in upper one-third of length. For evaluating the seismic effects on the capsules and related reactor structures by installation of the in-chimney bracket, an ANSYS analysis model is developed, and the dynamic characteristics are analyzed. The seismic response analyses of in-chimney bracket and related reactor structures of HANARO under the design earthquake response spectrum loads of SSE(0.2g) are performed. The several candidated designs of the capsule extension pipes and support spring stiffness to meet the displacement limit of the flow tubes in core region are proposed

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

    International Nuclear Information System (INIS)

    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 m3/h, no active water ascends from the core to the pool through the chimney. The model results are analyzed and discussed. (orig.)

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

    International Nuclear Information System (INIS)

    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 m3/h, no radioactive water ascends from the core to the pool through the chimney. The model results are analyzed and discussed

  11. Numerical simulation and comparison of conventional and sloped solar chimney power plants: the case for Lanzhou.

    Science.gov (United States)

    Cao, Fei; Li, Huashan; Zhang, Yang; Zhao, Liang

    2013-01-01

    The solar chimney power plant (SCPP) generates updraft wind through the green house effect. In this paper, the performances of two SCPP styles, that is, the conventional solar chimney power plant (CSCPP) and the sloped solar chimney power plant (SSCPP), are compared through a numerical simulation. A simplified Computational Fluid Dynamics (CFD) model is built to predict the performances of the SCPP. The model is validated through a comparison with the reported results from the Manzanares prototype. The annual performances of the CSCPP and the SSCPP are compared by taking Lanzhou as a case study. Numerical results indicate that the SSCPP holds a higher efficiency and generates smoother power than those of the CSCPP, and the effective pressure in the SSCPP is relevant to both the chimney and the collector heights. PMID:24489515

  12. 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...

  13. 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.

  14. 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

  15. 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)

  16. 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.

  17. Effects of industrial chimney gases on the Nif Mountain vegetation

    Energy Technology Data Exchange (ETDEWEB)

    Cireli, B.

    1975-01-01

    This investigation has been carried out on vegetation in order to find out changes in the morphology, anatomy and ultrastructure of cells brought about by the chimney gases from the surrounding factories. Different dicots and monocots have been used as experimental material. Results obtained are summarized as follows: (A) In all the experimental plants affected by the pollutants, an inhibition of the elongation has been observed. (B) Anatomical studies revealed that the epidermis, palisade and spongy parenchymatic tissues and cells of pollutant-affected plants appeared to be different from those of control plants. (C) Along with the anatomical changes, ultrastructural modifications have also been observed between pollutant-affected and control plants. (D) In order to investigate the causes of loss of green color in pollutant-affected plants, spectrophotometric pigmentation determinations have been carried out. The results have indicated such a decrease in pigment contents of pollutant-affected plants. (E) Calcium, magnesium and sulphate contents of control and pollutant-affected plants have been determined with an atomic absorption spectrophotometer. Pollutant-affected plants appeared to contain less calcium and magnesium and more sulphate than control plants. (F) Comparative oil analyses of fruits of pollutant-affected and control Olea plants have been carried out. (G) It has been concluded that air pollutants, affecting the various metabolic activities of the cells, cause modifications in the cell ultrastructure and cell anatomy and consequently give rise to typical morphological changes manifested in the form of growth inhibition.

  18. Results from measurements on the PV-VENT systems at Lundebjerg[DENMARK

    Energy Technology Data Exchange (ETDEWEB)

    Oestergaard Jensen, S.

    2001-05-01

    The objective of the PV-VENT project was research, development, and tests in the following areas: 1. Develop and illustrate different ways of architectural integration of solar energy systems with combined PV power production and pre-heating of ventilation air in buildings, 2. Investigate the potential in pre-heating fresh air to the building by cooling the PV-panels with the fresh air and further to determine how much this cooling will increase the electrical performance of the PV-panels, 3. Develop and test air to air heat exchangers with an efficiency of 80% or above, 4. Develop and test fans and ventilation systems with an overall fan power demand of about 35 W, 5. Develop and test a direct coupling of the PV-panels to the fans in order to avoid the losses in an inverter, 6. Develop and test different ventilation systems utilizing the abovementioned features. Three different ways of integrating PV-panels with pre-heating of fresh air to the building have been demonstrated in Lundebjerg: a large PV-gable with amorphous PV-panels, a PV-facade with polycrystalline (c-Si) PV-panels and solar ventilation chimneys with polycrystalline (c-Si) PV-panels. Especially the latter feature, the solar ventilation chimney is a new and interesting concept as it allows for increased PV areas although the orientation of the building is not optimal for utilization of solar energy, as was the case in Lundebjerg. It is believed that the PV-VENT project has added important information and experience to the field of combining PV and ventilation systems. Information and experience that future systems of this type may benefit from. Several of the components from the project are believed to be able to contribute to set the standards for future PV and ventilation systems. Several of the components from the project is today commercial available and are used in ordinary building projects. (BA)

  19. Computational studies on the effect of geometric parameters on the performance of a solar chimney power plant

    International Nuclear Information System (INIS)

    Graphical abstract: This work is aimed at optimizing the geometry of the major components of a solar chimney power plant using ANSYS-CFX. The collector inlet opening, collector height, collector outlet diameter, the chimney throat diameter and the chimney divergence angle were varied for the same chimney height and collector diameter and the performance of the plant was studied in terms of the available power and an optimum configuration was obtained. The temperature and velocity variations in the collector and along the chimney height were also studied. - Highlights: • Geometry of the major components of a solar chimney power plant optimized using CFX. • Collector inlet opening, height, outlet diameter, chimney throat diameter, and the chimney divergence angle were varied. • Temperature and velocity variations and available power were obtained for different configurations. • Optimum values of collector outlet height and diameter and the divergence angle were obtained. - Abstract: A solar chimney power plant (SCPP) is a renewable-energy power plant that transforms solar energy into electricity. The SCPP consists of three essential elements – solar air collector, chimney tower, and wind turbine(s). The present work is aimed at optimizing the geometry of the major components of the SCPP using a computational fluid dynamics (CFD) software ANSYS-CFX to study and improve the flow characteristics inside the SCPP. The overall chimney height and the collector diameter of the SCPP were kept constant at 10 m and 8 m respectively. The collector inlet opening was varied from 0.05 m to 0.2 m. The collector outlet diameter was also varied from 0.6 m to 1 m. These modified collectors were tested with chimneys of different divergence angles (0°–3°) and also different chimney inlet openings of 0.6 m to 1 m. The diameter of the chimney was also varied from 0.25 m to 0.3 m. Based on the CFX computational results, the best configuration was achieved using the chimney

  20. 40 CFR Table 3 to Subpart Ffff of... - Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP Metals Emissions From...

    Science.gov (United States)

    2010-07-01

    ... Halogen HAP Emissions or HAP Metals Emissions From Process Vents 3 Table 3 to Subpart FFFF of Part 63... to Subpart FFFF of Part 63—Emission Limits for Hydrogen Halide and Halogen HAP Emissions or HAP... following table that applies to your process vents that contain hydrogen halide and halogen HAP emissions...

  1. 40 CFR Table 8 to Subpart Uuu of... - Organic HAP Emission Limits for Catalytic Cracking Units

    Science.gov (United States)

    2010-07-01

    ... limit for each catalyst regenerator vent . . . 1. Subject to the NSPS for carbon monoxide (CO) in 40 CFR... in 40 CFR 60.103 a. CO emissions from the catalyst regenerator vent or CO boiler serving the... Catalytic Cracking Units 8 Table 8 to Subpart UUU of Part 63 Protection of Environment...

  2. 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.

  3. Les Ventes-de-Bourse

    OpenAIRE

    Besnard, Michel; Noël, Jean-Yves; Nové-Josserand, Jacques; Fromont, Nicolas

    2013-01-01

    Date de l'opération : 2007 (EX) Inventeur(s) : Fromont Nicolas (INRAP) Le diagnostic archéologique mené au logis des Ventes aux Ventes-de-Bourse, commune du sud de l’Orne, a permis d’observer une surface d’un peu moins de 24 ha, située en rive gauche de la Vézone, affluent de la Sarthe. La topographie des parcelles concernées est relativement plane ; elles prennent place sur un aplat perché quelques mètres seulement au-dessus de ces rivières. En outre, le substratum, constitué d’assises argil...

  4. Vibration test for HANARO in-chimney bracket and instrumented fuel assembly

    International Nuclear Information System (INIS)

    The vibration characteristics and structural integrity of the instrumented fuel assembly and in-chimney bracket structures, which is recently installed in HANARO reactor chimney, are investigated. For this purpose, four acceleration data on the guide tube of the instrumented fuel assembly and in-chimney bracket structures subjected to fluid induced vibration are measured and analyzed. In time domain analysis, maximum amplitudes and RMS values of accelerations and displacements are obtained from the measured vibration signal. The frequency components of the vibration data are analyzed by using the frequency domain analysis. These analysis results show that the levels of the measured vibrations are within the allowable limit, and the low frequency component near 10 Hz is dominant in the vibration signal. For the evaluation of the structural integrity on the in-chimney bracket and related structures, the static analysis for ANSYS finite element model is carried out. The maximum displacements of the measured vibration signals are used as the load inputs. These analysis results show that the maximum stresses and within the allowable stresses of the ASME code, and the maximum displacement at the top of the flow tube is within the displacement limit. Therefore any damage on the structural integrity is not expected when the irradiation test is performed using the in-chimney bracket

  5. 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)

  6. 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.)

  7. Feasibility study on optimization of a typical solar chimney power plant

    Science.gov (United States)

    Najmi, Mohsen; Nazari, Ali; Mansouri, Hossein; Zahedi, Ghazzanfar

    2012-03-01

    The solar chimney which has been built in Kerman (Kerman city-Iran) is a small scale electrical power plant. The chimney of this unit has 60 m height and 3 m diameter. The collector of this unit is 40 m × 40 m square. To reach nominal power of this unit of power plant, parameters which are effective in optimization are studied. In this regard, we deliberate and propose suggestions to maximize usage of solar energy and kinetic energy. The calculation of maximum power is one of the objectives of this study, so the paper present economic analysis for Kerman solar chimney. A home code has been written for this modeling, in MATLAB.

  8. Research related to filtered venting system

    International Nuclear Information System (INIS)

    This paper describes how to write a manuscript of the 18th PES Proceedings. In the Fukushima Daiichi Nuclear Power Plant accident, a great deal of radioactive material was released to surrounding environment. After the accident, the Filtered Containment Venting System (FCVS) that can remove radioactive material from steam in containment vessel has attracted a great deal of attentions. However, there is few knowledge of filtered vent in Japan because almost filtered vent were developed in Europe after Chernobyl nuclear power plant accident. Therefore, our purpose is getting the knowledge of filtered vent through experiments that simulate various filter vents in Europe. Also using the knowledge gotten through experiment, we aim at developing high efficiency filtered containment venting system using zeolite. (author)

  9. Studies of the thermohydraulics of the Irradiation Research Facility (IRF) chimney using computational fluid dynamics

    International Nuclear Information System (INIS)

    AECL is developing a concept for a new Irradiation Research Facility (IRF) that will be used to support ongoing development of CANDU technology and advanced materials research after the NRU reactor shuts down. As part of the IRF Pre-Project Engineering Program, computational fluid dynamics (CFD) analyses of the flow patterns and heat transfer within four reactor components - the inlet plenum, reflector tank, chimney, and the pool - were done to support the design. This paper describes the results of the CFD analyses of the IRF chimney. (author)

  10. 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

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

    Energy Technology Data Exchange (ETDEWEB)

    Ryu, Jeong Soo; Cho, Yeong Garp; Lee, Jung Hee; Jung, Hoan Sung; Seo, Choon Gyo; Shin, Jin Won

    2007-12-15

    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 {approx} 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

  12. 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.

  13. Summary of performance test for filtered vent

    International Nuclear Information System (INIS)

    TOSHIBA has been carried tests to evaluate performance of the filtered vent system. In order to apply several parameters and functions, test facility is useful and has much flexibility. The filtered vent system has 2 functions, one is scrubbing in water and the other is metal filter. Test results show a good performance. We will introduce a outline of the filtered vent system examination. (author)

  14. Numerical study on mixed buoyancy-wind driving induced flow in a solar chimney for building ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, B.; Kaiser, A.S. [Dpto. Ingenieria Termica y de Fluidos, Universidad Politecnica de Cartagena, Doctor Fleming s/n, 30202 Cartagena (Spain)

    2010-09-15

    In a solar chimney, the buoyancy induced flow of air generates ventilation of the building where the chimney is attached. When atmospheric wind blows over the upper part of a solar chimney, a mixed buoyancy-wind driving induced flow appears, and then the thermal behaviour of the chimney changes drastically. Assuming that the chimney is devoid of any protective device at its upper part, numerical results for the pressure difference coefficients, average Nusselt number and the induced mass flow rate are obtained for values of Rayleigh number varying from 10{sup 7} to 10{sup 12} (symmetrically, isothermal heating condition) and 10{sup 11} to 10{sup 15} (symmetrically, uniform heat flux heating condition), with wind speeds from 0 to 10 m/s. A correlation for the non-dimensional mass flow rate is presented, which is valid for the complete range of relevant parameters regarded, with an average deviation about 6%. (author)

  15. 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.

  16. 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

  17. 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.

  18. 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.

  19. Genomic Reconstruction of an Uncultured Hydrothermal Vent Gammaproteobacterial Methanotroph (Family Methylothermaceae) Indicates Multiple Adaptations to Oxygen Limitation.

    Science.gov (United States)

    Skennerton, Connor T; Ward, Lewis M; Michel, Alice; Metcalfe, Kyle; Valiente, Chanel; Mullin, Sean; Chan, Ken Y; Gradinaru, Viviana; Orphan, Victoria J

    2015-01-01

    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. PMID:26779119

  20. 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.

  1. Influence of Chimney Flow Pattern on Natural Convection Heat Transfer of Open Channel Finned Plates

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Seung-Hyun; Chung, Bum-Jin [Kyung Hee University, Yongin (Korea, Republic of)

    2015-05-15

    The enhancement of the efficiency and effectiveness of the passive cooling system, have long been the topic of those studies. In this study, we investigated the heat transfer enhancement of finned plates, especially the chimney effect appeared in finned plates. The fin not only enlarges the heat transfer area but also draws fresh fluid from the open side of the channel composed of the base plate and fins, which further enhances the cooling capability of finned plate – a chimney flow pattern. This study aims at investigating the influence of the chimney flow pattern on the natural convection heat transfer of the finned plate. To analyze the phenomenological study, both experimental and numerical analyses were performed. Numerical analysis was performed for the natural convection heat transfer of a finned plate in an open channel. In order to investigate the influence of the chimney flow pattern the heat transfer, several fin height were simulated and compared. The temperature profiles varied drastically depending on the values of the Prandtl number. As the Prandtl number increases, the thermal boundary layer reduces.

  2. Influence of Chimney Flow Pattern on Natural Convection Heat Transfer of Open Channel Finned Plates

    International Nuclear Information System (INIS)

    The enhancement of the efficiency and effectiveness of the passive cooling system, have long been the topic of those studies. In this study, we investigated the heat transfer enhancement of finned plates, especially the chimney effect appeared in finned plates. The fin not only enlarges the heat transfer area but also draws fresh fluid from the open side of the channel composed of the base plate and fins, which further enhances the cooling capability of finned plate – a chimney flow pattern. This study aims at investigating the influence of the chimney flow pattern on the natural convection heat transfer of the finned plate. To analyze the phenomenological study, both experimental and numerical analyses were performed. Numerical analysis was performed for the natural convection heat transfer of a finned plate in an open channel. In order to investigate the influence of the chimney flow pattern the heat transfer, several fin height were simulated and compared. The temperature profiles varied drastically depending on the values of the Prandtl number. As the Prandtl number increases, the thermal boundary layer reduces

  3. 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

  4. DESIGN OF A SMALL – SCALE SOLAR CHIMNEY FOR SUSTAINABLE POWER

    Science.gov (United States)

    After several months of design and testing it has been determined that a small scale solar chimney can be built using nearly any local materials and simple hand tools without needing superior construction knowledge. The biggest obstacle to over come was the weather conditions....

  5. Analysis and feasibility of implementing solar chimney power plants in the Mediterranean region

    International Nuclear Information System (INIS)

    This paper analyzes the feasibility of solar chimney power plants as an environmentally acceptable energy source for small settlements and islands of countries in the Mediterranean region. For the purpose of these analyses, two characteristic geographic locations (Split and Dubrovnik) in Croatia were chosen and simplified model for calculation of produced electric power output is also developed. These locations possess typical characteristics of the Mediterranean climate. The solar characteristics of the chosen geographic locations are shown along with characteristic meteorological data. A solar chimney (SC) power plant with a chimney height of 550 m and a collector roof diameter of 1250 m would produce 2.8-6.2 MW of power. The average annual electric power production of this SC power plant would range between 4.9 and 8.9 GWh/year, but in reality from 5.0 to 6.0 GWh/year in average. An approximate costs analysis, which included a total investment estimate, was performed. The levelized electricity cost was also calculated. It is found that the price of produced electric energy by solar chimney power plant in Mediterranean region is considerably higher compared to the other power sources. (author)

  6. Numerical analysis on the performance of solar chimney power plant system

    International Nuclear Information System (INIS)

    Power generating technology based on renewable energy resources will definitely become a new trend of future energy utilization. Numerical simulations on air flow, heat transfer and power output characteristics of a solar chimney power plant model with energy storage layer and turbine similar to the Spanish prototype were carried out in this paper, and mathematical model of flow and heat transfer for the solar chimney power plant system was established. The influences of solar radiation and pressure drop across the turbine on the flow and heat transfer, output power and energy loss of the solar chimney power plant system were analyzed. The numerical simulation results reveal that: when the solar radiation and the turbine efficiency are 600 W/m2 and 80%, respectively, the output power of the system can reach 120 kW. In addition, large mass flow rate of air flowing through the chimney outlet become the main cause of energy loss in the system, and the collector canopy also results in large energy loss.

  7. 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.

  8. 78 FR 72060 - Chimney Rock National Monument Management Plan; San Juan National Forest; Colorado

    Science.gov (United States)

    2013-12-02

    .... Forest Service (USFS) planning regulations (36 CFR part 219) as allowed by the transition provision of the 2012 forest planning regulations. The 1982 planning regulations are available at http://www.fs.fed...; ] DEPARTMENT OF AGRICULTURE Forest Service Chimney Rock National Monument Management Plan; San Juan...

  9. Economic analysis of power generation from floating solar chimney power plant

    International Nuclear Information System (INIS)

    Solar chimney thermal power technology that has a long life span is a promising large-scale solar power generating technology. This paper performs economic analysis of power generation from floating solar chimney power plant (FSCPP) by analyzing cash flows during the whole service period of a 100 MW plant. Cash flows are influenced by many factors including investment, operation and maintenance cost, life span, payback period, inflation rate, minimum attractive rate of return, non-returnable subsidy rate, interest rate of loans, sale price of electricity, income tax rate and whether additional revenue generated by carbon credits is included or not. Financial incentives and additional revenue generated by carbon credits can accelerate the development of the FSCPP. Sensitivity analysis to examine the effects of the factors on cash flows of a 100 MW FSCPP is performed in detail. The results show that the minimum price for obtaining minimum attractive rate of return (MARR) of 8% reaches 0.83 yuan (kWh)-1 under financial incentives including loans at a low interest rate of 2% and free income tax. Comparisons of economics of the FSCPP and reinforced concrete solar chimney power plant or solar photovoltaic plant are also performed by analyzing their cash flows. It is concluded that FSCPP is in reality more economical than reinforced concrete solar chimney power plant (RCSCPP) or solar photovoltaic plant (SPVP) with the same power capacity. (author)

  10. 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

  11. A Table! (At the Table).

    Science.gov (United States)

    Terry, Robert M.

    A review of French dining habits and table manners outlines: elements of the place setting, courtesies used at the table, serving conventions, restaurant tipping, the size and content of the different meals of the day, subtle differences in common foods, restaurant types, menu types, general wine and cheese choices, waiter-client communication,…

  12. The vented pressure fed gas journal bearing

    International Nuclear Information System (INIS)

    Hydrodynamic-type gas journal bearings with stabilising venting slots are often operated hydrostatically during starting-up as a means of 'jacking'. A simplified mathematical treatment of the circumferential gas flows in a vented, pressure-fed journal bearing is used to predict the relationship between load capacity, bearing geometry and gas properties. (author)

  13. 46 CFR 98.25-70 - Venting.

    Science.gov (United States)

    2010-10-01

    ... the back pressure in relief valve discharge lines shall not be more than 10 percent of the safety relief valve setting. (d) Return bends and restrictive pipe fittings are prohibited. Vents and headers shall be so installed as to prevent stresses on safety relief valve mountings. (e) When vent...

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. A study on thermo-hydraulic instability of boiling natural circulation loop with a chimney. 4. An analytical consideration of the stability and thermo-hydraulic characteristics in the chimney in high pressure

    International Nuclear Information System (INIS)

    Thermo-hydraulic instabilities of a boiling natural circulation loop with a chimney under high pressure were investigated using linear stability analysis. Drift-flux model was used for two-phase flow model. The instability regions as well as the thermo-hydraulic characteristics in the chimney such as wavy feature were examined, which were compared with the characteristics in low pressure. Instability could occur when exit quality was relatively low, which was the same manner as the characteristics in low pressure. In high-pressure, void was generated near channel exit, and void wave propagated in the chimney. In low pressure, steam was generated only near the chimney exit due to gravity induced flashing, and single-phase enthalpy wave, that is, temperature wave propagated in single-phase flow region. Though flow could be very stable in the high pressure and high power condition, the decay ratio of higher mode could be larger than that of lower mode. (author)

  19. 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

  20. Sources of organic carbon for Rimicaris hybisae: Tracing individual fatty acids at two hydrothermal vent fields in the Mid-Cayman rise

    Science.gov (United States)

    Streit, Kathrin; Bennett, Sarah A.; Van Dover, Cindy L.; Coleman, Max

    2015-06-01

    Hydrothermal vents harbor ecosystems mostly decoupled from organic carbon synthesized with the energy of sunlight (photosynthetic carbon source) but fueled instead by oxidation of reduced compounds to generate a chemosynthetic carbon source. Our study aimed to disentangle photosynthetic and chemosynthetic organic carbon sources for the shrimp species Rimicaris hybisae, a primary consumer presumed to obtain its organic carbon mainly from ectosymbiotic chemoautotrophic bacteria living on its gill cover membrane. To provide ectosymbionts with ideal conditions for chemosynthesis, these shrimp live in dense clusters around vent chimneys; they are, however, also found sparsely distributed adjacent to diffuse vent flows, where they might depend on alternative food sources. Densely and sparsely distributed shrimp were sampled and dissected into abdominal tissue and gill cover membrane, covered with ectosymbiotic bacteria, at two hydrothermal vent fields in the Mid-Cayman rise that differ in vent chemistry. Fatty acids (FA) were extracted from shrimp tissues and their carbon isotopic compositions assessed. The FA data indicate that adult R. hybisae predominantly rely on bacteria for their organic carbon needs. Their FA composition is dominated by common bacterial FA of the n7 family (~41%). Bacterial FA of the n4 FA family are also abundant and found to constitute good biomarkers for gill ectosymbionts. Sparsely distributed shrimp contain fractions of n4 FA in gill cover membranes ~4% lower than densely packed ones (~18%) and much higher fractions of photosynthetic FA in abdominal tissues, ~4% more (compared with 1.6%), suggesting replacement of ectosymbionts along with exoskeletons (molt), while they take up alternative diets of partly photosynthetic organic carbon. Abdominal tissues also contain photosynthetic FA from a second source taken up presumably during an early dispersal phase and still present to c. 3% in adult shrimp. The contribution of photosynthetic carbon to

  1. 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....

  2. 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....

  3. 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.

  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. DESIGN NOTE: Ultrasonic velocity meter to evaluate the behaviour of a solar chimney

    Science.gov (United States)

    Olmos, P.

    2004-07-01

    The addition of solar chimneys represents a substantial improvement in the natural ventilation scheme of a building and is thus an important component of so-called passive cooling, mainly in warm climates. In order to evaluate and/or control its performance, an accurate measurement of the velocity and temperature of the air passing through the duct is needed. Normal commercial equipment, developed for other applications, does not suit this particular scenario very well. An ultrasonic velocity meter has been specially designed, manufactured and tested inside an actual chimney, proving that this approach is a reliable solution to the problem of measuring the ventilation parameters. Here a detailed description of the instrument is given, along with a presentation of its first operational tests.

  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. 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.

  8. Active reduction of the dominant clear tone component of the noise pollution from power plant chimneys

    International Nuclear Information System (INIS)

    An investigation of a system for active reduction of an irritating dominant clear tone emitted as a part of the noise pollution from a power plant chimney is described. Experiments were carried out on a scale model with diameters 3-4 times less than the actual chimney. Reduction of 25-30 decibels was achieved in relation to the clear tone in the frequency range in connection with which it could be expected that the noise-muffling system would work. The system was also seen to be able to follow the expected variation in the noise signals and to be stable during a longer period of time. The theories on which the experiment was based, the experimental setup and measurement methods and results are presented. (AB)

  9. 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.

  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. Lung function in woodsmoke-exposed Guatemalan children following a chimney stove intervention.

    OpenAIRE

    Heinzerling, AP; Guarnieri, MJ; Mann, JK; Diaz, JV; Thompson, LM; Diaz, A.; Bruce, NG; Smith, KR; Balmes, JR

    2016-01-01

    Household air pollution (HAP) from solid fuel combustion is a major contributor to the global burden of disease, with considerable impact from respiratory infections in children. The impact of HAP on lung function is unknown.The Childhood Exposure to Respirable Particulate Matter (CRECER) prospective cohort study followed Guatemalan children who participated in the Randomised Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) trial of a chimney stove intervention to determi...

  12. Uranium prospecting in alkaline mountain chimneys of Serra Negra and Salitre - Minas Gerais, Brasil

    International Nuclear Information System (INIS)

    The occurence of radioactive minerals such as apatite and pyrochlore, in the alkaline chimneys of Serra Negra and Salitre (Minas Gerais, Brazil), is discussed. Also mentioned are other minerals of interest associated with the alkaline magma such as columbite, fluorite, monazite, zircon, baddeleyite, etc, which in favourable conditions may occur in deposits of great economical value, and which may present high contents of rare earths, thorium and uranium

  13. Performance analysis of conventional and sloped solar chimney power plants in China

    International Nuclear Information System (INIS)

    The solar chimney power plant (SCPP) has been accepted as one of the most promising approaches for future large-scale solar energy applications. This paper reports on a heat transfer model that is used to compare the performance of a conventional solar chimney power plant (CSCPP) and two sloped solar chimney power plants (SSCPPs) with the collector oriented at 30° and 60°, respectively. The power generation from SCPPs at different latitudes in China is also analyzed. Results indicate that the larger solar collector angle leads to improved performance in winter but results in lower performance in summer. It is found that the optimal collector angle to achieve the maximum power in Lanzhou, China, is around 60°. Main factors that influence the performance of SCPPs also include the system height and the air thermophysical characteristics. The ground energy loss, reflected solar radiation, and kinetic loss at the chimney outlet are the main energy losses in SCPPs. The studies also show SSCPPs are more suitable for high latitude regions in Northwest China, but CSCPPs are suggested to be built in southeastern and eastern parts of China with the combination to the local agriculture. - Highlights: ► The optimum collector angle for maximum power generation is 60° in Lanzhou. ► Main parameters influencing performances are the system height and air property. ► Ground loss, reflected loss and outlet kinetic loss are the main energy losses. ► The sloped styles are suitable for Northwest China. ► The conventional styles are suitable for Southeast and East China.

  14. 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

  15. 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.

  16. Numerical investigation of a plume from a power generating solar chimney in an atmospheric cross flow

    Science.gov (United States)

    Zhou, Xinping; Yang, Jiakuan; Ochieng, Reccab M.; Li, Xiangmei; Xiao, Bo

    2009-01-01

    A plume in an atmospheric cross flow from a power generating solar chimney is investigated using a three-dimensional numerical simulation model. The simulation model is validated by comparing the data calculated using our model with the numerical simulated results for one-dimensional buoyancy-driven compressible flow in a proposed 1500 m high solar chimney. In this paper, the parametric performances including static pressure, static temperature, density, streamline, and relative humidity field of the flow at the symmetry plane, at the cross plane 2700 m high and at the cross plane 750 m high in the geometry are simulated. It is found that relative humidity of the plume is greatly increased due to the jet of a plume into the surroundings colder than the plume. In addition to a great amount of tiny granules in the plume originating from the ground as effective condensation nuclei of moisture, a condensation would occur, a cloud system and precipitation e.g. rainfall, snow and hail would be formed around the plume when vapor is supersaturated. It is also found that with an increase in chimney height or relative humidity of atmosphere, or a reduction in wind velocity, relative humidity is increased, and increases the probability of precipitation and the potential precipitation areas. Furthermore, the latent heat released from the condensation of supersaturated vapor can aid the plume to keep on rising.

  17. Heat transfer by convection, conduction and radiation in solar chimney systems for ventilation of dwellings

    International Nuclear Information System (INIS)

    Numerical study by conjugate heat transfer is carried out of solar chimney systems for heating and ventilation of dwellings. Conservation equations are solved by finite difference-control volume numerical method. The governing parameters were: the Rayleigh numbers from 5 x 108 to 1011, the Prandtl number, Pr = 0.7, constant for air, the chimney aspect ratio, A = H/L from 6 to 15, the air channel width l'/L = 0.2 to 0.5, the air entrance port size, h/L = 0.167-0.667, the wall thickness l/L = 0.25-0.4, the conductivity ratio kr from 5 to 50 and the surface emissivity, ε from 0 to 1. The Nusselt number, the dimensionless volume flow rate V. and radiation heat flux ratio qr/qtot are calculated as a function of the governing parameters, and streamlines and isotherms are produced. The results show that the surface radiation modifies the flow and temperature fields, affects the Nusselt number and the volume flow rate, both in a positive way, and improves the ventilation performance of the chimneys

  18. 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.

  19. A scaling investigation of the laminar convective flow in a solar chimney for natural ventilation

    International Nuclear Information System (INIS)

    Highlights: • Scaling investigation of a solar chimney for ventilation is carried out. • Three distinct flow regimes are identified depending on the Rayleigh number. • Scaling relations are proposed to describe the transient flow development and are verified by numerical data. -- Abstract: The flow behavior due to natural convection of air (with a Prandtl number less than 1) inside a solar chimney with an imposed heat flux on a vertical absorber wall is investigated by a scaling analysis and a corresponding numerical simulation. Three distinct flow regimes are identified, one with a distinct thermal boundary layer and the other two without a distinct thermal boundary layer, depending on the Rayleigh number. The two regimes without a distinct thermal boundary layer are further classified into low and medium Rayleigh number sub-regimes respectively. These sub-regimes are characterized by conduction dominance in which the thermal boundary layer grows to encompass the entire width of the channel before convection becomes important. Flow development in each of these flow regimes and sub-regimes is characterized through transient scaling, and scaling correlations are developed to describe the temperature, flow velocity and mass flow rate, which characterize the ventilation performance of the solar chimney. The scaling arguments are validated by the corresponding numerical data

  20. Liquid Carbon Dioxide Venting at the Champagne Hydrothermal Site, NW Eifuku Volcano, Mariana Arc

    Science.gov (United States)

    Lupton, J.; Lilley, M.; Butterfield, D.; Evans, L.; Embley, R.; Olson, E.; Proskurowski, G.; Resing, J.; Roe, K.; Greene, R.; Lebon, G.

    2004-12-01

    In March/April 2004, submersible dives with the remotely-operated vehicle ROPOS discovered an unusual CO2-rich hydrothermal system near the summit of NW Eifuku, a submarine volcano located at 21.49° N, 144.04° E in the northern Mariana Arc. Although several sites of hydrothermal discharge were located on NW Eifuku, the most intense venting was found at 1600-m depth at the Champagne site, slightly west of the volcano summit. The Champagne site was found to be discharging two distinct fluids into the ocean: a) several small white chimneys were emitting milky 103° C gas-rich hydrothermal fluid with at least millimolar levels of H2S and b) cold (grapes. The film coating the droplets was assumed to be CO2 hydrate (or clathrate) which is known to form whenever liquid CO2 contacts water under these P,T conditions. Samples of the 103° C hydrothermal fluids were collected in special gas-tight titanium sampling bottles that were able to withstand the high internal pressures created by the dissolved gases. The Champagne hydrothermal fluids contained a surprising 2.3 moles/kg of CO2, an order of magnitude higher than any CO2 values previously reported for submarine hydrothermal fluids. The overall gas composition was 87% CO2, yielded δ 13C = -1.75 ‰ , much heavier than the -6.0 ‰ typical for carbon in MOR vent fluids. The C/3He ratio was ~2.2 x 1010, an order of magnitude higher than the average value of 2 x 109 found in MOR vent fluids. The δ 13C and C/3He values suggest a substantial contribution to the carbon from subducted carbonates rather than mantle carbon. The Champagne site is only the second locality where liquid CO2 has been observed venting into the deep sea (the other reported location is in the Okinawa Trough, see Sakai et al., 1990). Because of the presence of liquid CO2 in proximity to hydrothermal organisms, the Champagne site may prove to be a valuable natural laboratory for studying the effects of high CO2 concentrations on marine ecosystems.

  1. Continuous In Situ Measurements of Near Bottom Chemistry and Sediment-Water Fluxes with the Chimney Sampler Array (CSA)

    Science.gov (United States)

    Martens, C. S.; Mendlovitz, H. P.; White, B. L.; Hoer, D.; Sleeper, K.; Chanton, J.; Wilson, R.; Lapham, L.

    2011-12-01

    The Chimney Sampler Array (CSA) was designed to measure in situ chemical and physical parameters within the benthic boundary layer plus methane and oxygen sediment-water chemical fluxes at upper slope sites in the northern Gulf of Mexico. The CSA can monitor temporal changes plus help to evaluate oceanographic and sub-seafloor processes that can influence the formation and stability of gas hydrates in underlying sediments. The CSA consists of vertical cylinders (chimneys) equipped with internal chemical sensors and with laboratory flume-calibrated washout rates. Chimney washout rates multiplied by chimney mean versus ambient concentrations allow calculation of net O2 and methane sediment-water fluxes. The CSA is emplaced on the seafloor by a ROVARD lander using a ROV for chimney deployments. The CSA presently includes two 30 cm diameter by 90 cm length cylinders that seal against the sediment with lead pellet beanbags; within each chimney cylinder are optode, conductivity and methane sensors. The CSA's data logger platform also includes pressure and turbidity sensors external to the chimneys along with an acoustic Doppler current meter to measure temporal variation in ambient current velocity and direction. The CSA was deployed aboard a ROVARD lander on 9/13/2010 in the northern Gulf of Mexico (Lat. 28 51.28440, Long. 088 29.39421) on biogeochemically active sediments within Block MC-118. A ROV was utilized for chimney deployment away from the ROVARD lander. The CSA monitored temporal changes in water column physical parameters, obtained near-bottom chemical data to compare with pore fluid and sediment core measurements and measured temporal variability in oxygen and methane sediment-water fluxes at two closely spaced stations at MC-118. A continuous, three-week data set was obtained that revealed daily cycles in chemical parameters and episodic flux events. Lower than ambient chimney dissolved O2 concentrations controlled by temporal variability in washout rates

  2. 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

  3. 14 CFR 23.975 - Fuel tank vents and carburetor vapor vents.

    Science.gov (United States)

    2010-01-01

    ... or level flight attitudes, unless drainage is provided. Any drain valve installed must be accessible... will constitute a fire hazard or from which fumes may enter personnel compartments; and (7) Vents must... venting capacity must allow the rapid relief of excessive differences of pressure between the interior...

  4. Visualization test of filtered vent and evaluation of source term

    International Nuclear Information System (INIS)

    In the Fukushima Daiichi Nuclear Power Plant accident, a great deal of radioactive material was released to surrounding environment. After the accident, the Filtered Containment Venting System (FCVS) that can remove radioactive material from steam in containment vessel has attracted a great deal of attentions. However, there is few knowledge of filtered vent in Japan because almost filtered vent were developed in Europe after Chernobyl nuclear power plant accident. Therefore, our purpose is getting the knowledge of filtered vent through experiments that simulate various filter vents in Europe. Also using the knowledge gotten through experiment, we aim at developing high efficiency filtered containment venting system using zeolite. (author)

  5. 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

  6. 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.

  7. Evaluation of the influence of soil thermal inertia on the performance of a solar chimney power plant

    International Nuclear Information System (INIS)

    Solar chimney power plants are a technology capable to generate electric energy through a wind turbine using the solar radiation as energy source; nevertheless, one of the objectives pursued since its invention is to achieve energy generation during day and night. Soil under the power plant plays an important role on the energy balance and heat transfer, due to its natural behavior as a heat storage system. The characteristics of the soil influence the ability of the solar chimney power plant to generate power continuously. Present work analyzes the thermodynamic behavior and the power output of a solar chimney power plant over a daily operation cycle taking into account the soil as a heat storage system, through a numerical modeling under non-steady conditions. The influence of the soil thermal inertia and the effects of soil compaction degree on the output power generation are studied. A sizeable increase of 10% in the output power is obtained when the soil compaction increases. -- Highlights: ► Solar chimney power plants are a technology capable to generate renewable energy from solar radiation. ► The ground under the solar chimney can act as a heat storage system. ► The soil thermal inertia plays a relevant role in a scenario where the plant operates continuously. ► A higher compaction of soil causes a relevant increase on total energy generation.

  8. 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

  9. 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%.

  10. 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 ...

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

    International Nuclear Information System (INIS)

    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

  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. 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.

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

    Science.gov (United States)

    Islamuddin, Azeemuddin; Al-Kayiem, Hussain H.; Gilani, Syed I.

    2013-06-01

    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.

  16. Experimental investigations of the sodium/air heat exchanger with natural draught chimney for the EFR

    International Nuclear Information System (INIS)

    In a first series of experiments in the new large sodium experimental plant ILONA, the post-shutdown heat removal system for the European Fast Breeder Reactor EFR developed by Interatom and working by natural convection was tested. The air-side flow in the heat exchanger and chimney was optimized in extensive model experiments and the results were taken into account in the construction of the Na/air heat exchanger in the ILONA. A considerable increase in output was achieved, compared to the design, based on the flow model experiments for the ILONA heat exchanger. (orig.)

  17. 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.

  18. Preoperational test report, vent building ventilation system

    International Nuclear Information System (INIS)

    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

  19. 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...

  20. 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....

  1. 40 CFR 63.1425 - Process vent control requirements.

    Science.gov (United States)

    2010-07-01

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

  2. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Science.gov (United States)

    2010-07-01

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

  3. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Science.gov (United States)

    2010-07-01

    ... from all aggregate batch vent streams in the compliance demonstration required for reactor batch... comply with the mass emission limit for reactor batch process vents. ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Aggregate batch vent stream...

  4. 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)

  5. Steam vent tube for BWR fuel assembly

    International Nuclear Information System (INIS)

    This patent describes an improvement in a fuel bundle for a boiling water reactor having: vertically aligned spaced apart fuel rods for forming a fuel rod group within the fuel bundle for generation of a fission reaction in the presence of water moderator, a lower tie plate for admitting water moderator through the lower tie plate to the interstitial volume between the fuel rods and supporting the vertically aligned and spaced apart fuel rods, an upper tie plate for permitting water and steam to be discharged from the top of the fuel bundle and maintaining the vertically aligned and spaced apart fuel rods in upstanding spaced apart side-by-side relation, a surrounding fuel channel for confining moderator flow along a path over the fuel rods and from the lower tie plate to the upper tie plate. The improvement comprises: a least one steam vent tube overlying at least one of the part length rods; means supporting the stem vent tube in the volume overlying the part length rod, the steam vent tube being supported in the volume of the fuel bundle between the end of the part length rod and the upper tie plate; the steam vent tube defining an opening disposed to the end of the part length rod for the receipt of steam moderator within the void overlying the part length rod; the steam vent tube further defining an opening disposed to the upper tie plant and away from the end of the part length rod for the discharge of steam moderator from the fuel bundle

  6. 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.

  7. Gas chimney detection based on improving the performance of combined multilayer perceptron and support vector classifier

    Directory of Open Access Journals (Sweden)

    H. Hashemi

    2008-11-01

    Full Text Available Seismic object detection is a relatively new field in which 3-D bodies are visualized and spatial relationships between objects of different origins are studied in order to extract geologic information. In this paper, we propose a method for finding an optimal classifier with the help of a statistical feature ranking technique and combining different classifiers. The method, which has general applicability, is demonstrated here on a gas chimney detection problem. First, we evaluate a set of input seismic attributes extracted at locations labeled by a human expert using regularized discriminant analysis (RDA. In order to find the RDA score for each seismic attribute, forward and backward search strategies are used. Subsequently, two non-linear classifiers: multilayer perceptron (MLP and support vector classifier (SVC are run on the ranked seismic attributes. Finally, to capitalize on the intrinsic differences between both classifiers, the MLP and SVC results are combined using logical rules of maximum, minimum and mean. The proposed method optimizes the ranked feature space size and yields the lowest classification error in the final combined result. We will show that the logical minimum reveals gas chimneys that exhibit both the softness of MLP and the resolution of SVC classifiers.

  8. 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.

  9. The use of a rubble chimney for denitrification of irrigation return waters

    International Nuclear Information System (INIS)

    Biological denitrification has been proposed as a means of removing nitrates from waste waters to control eutrophication in receiving waters. A potential use for this method is the treatment of irrigation return waters containing high concentrations of nitrate-nitrogen, since direct discharge of such wastes may cause objectionable algal growth in the receiving waters. For example, the process may be used to treat agricultural waste waters in the San Joaquin Valley in California, where an estimated 580,000 acre-feet/year of return waters, containing 20 mg/l of nitrate-nitrogen, will require disposal by A.D. 2020. Two methods of biological denitrification are presently under study for possible use in the San Joaquin Valley. In one method nitrates are reduced to nitrogen gas by bacterial action in deep ponds; in the other method bacterial denitrification takes place in biological filters. In biological filters, bacteria are grown on columns of submerged stones. A possible alternative to the conventional construction of these filters is the creation of a rubble chimney by a contained nuclear explosion. This paper presents the results of a preliminary investigation of the feasibility of using a rubble chimney as a biological filter for denitrification. (author)

  10. 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

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

    OpenAIRE

    Teske, Andreas; de Beer, Dirk; McKay, Luke J.; Margaret K. Tivey; 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 sediment...

  12. 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

  13. 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.

  14. Comparative Study of Vented vs. Unvented Crawlspaces

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-10-01

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

  15. On small disturbance ascent vent behavior

    Science.gov (United States)

    Woronowicz, M. S.

    2012-10-01

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

  16. The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats

    DEFF Research Database (Denmark)

    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. Antecedent and progress of the project on the treatment of chimney gases with electrons in Mexico

    International Nuclear Information System (INIS)

    After the realization of the chimney gases treatment seminar with electrons, organized jointly among the National Institute of Nuclear Research (ININ) and the International Atomic Energy Agency (IAEA), in August of 1990 and following one of the received recommendations, it was elaborated an economic technical feasibility study of this process in Mexico, using technical data of a thermoelectric power station of Federal Commission of Electricity, where is being consumed fuel oil. This study is good to know some technical parameters of a plant of this process, proposed to settle in Mexico, so as some economic estimates of installation and operation costs of this plant; also, it is traced about the construction of a demonstration plant of the process, with capacity of 20,000 m3N/h, using the same data of the thermoelectric power station considered previously, as the first step in the scaling of this process toward industrial level. (Author)

  18. 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.

  19. A First Approach to Natural Thermoventilation of Residential Buildings through Ventilation Chimneys Supplied by Solar Ponds

    Directory of Open Access Journals (Sweden)

    Ferdinando Salata

    2015-07-01

    Full Text Available The exploitation of natural ventilation is a good solution to improve buildings from an energetic point of view and to fulfill the requirements demanded by the thermohygrometric comfort and the air quality in enclosed spaces. Some past researches demonstrated how some devices, useful to this purpose, follow the principles of solar chimneys and are able to move air masses while exploiting the Archimedes thrust. The natural ventilation must be supplied by a flow moving upward, generated by a heat source performing at temperatures slightly higher than the one present in the environment. To have a minimum energetic effect, the heat can be extracted from solar ponds; solar ponds are able to collect and store solar energy in the geographical regions characterized by sufficient values of solar radiation. Thus it is possible, in summer, to provoke a nocturnal natural ventilation useful for the air change in indoor spaces (in those climatic areas where, during the night, there is a temperature gradient.

  20. 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.

  1. 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...

  2. VentPlan: a ventilator-management advisor.

    OpenAIRE

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

    1991-01-01

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

  3. 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

  4. Vented combustion of hydrogen-air mixtures in large volumes

    International Nuclear Information System (INIS)

    Vented combustion experiments with hydrogen-air mixtures were conducted in a 2.3-m-diameter sphere connected to a cylinder (volume, 10.3 m/sup 3/). The experiments were carried out over a concentration range of 6 to 42% hydrogen by volume and at near atmospheric temperatures and pressures. Vent sizes of 15 and 25 cm have been used. It was found that venting was effective in reducing the peak pressures at low hydrogen concentrations; at high hydrogen concentrations, because of short combustion times, venting was less effective

  5. 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

  6. Formation of carbonate chimneys in the Mediterranean Sea linked to deep-water oxygen depletion

    OpenAIRE

    Bayon, Germain; Dupre, Stephanie; Ponzevera, Emmanuel; Etoubleau, Joel; Cheron, Sandrine; Pierre, Catherine; Mascle, Jean; Boetius, Antje; De Lange, Gert J.

    2013-01-01

    Marine sediments at ocean margins vent substantial amounts of methane(1,2). Microbial oxidation of the methane released can trigger the precipitation of carbonate within sediments and support a broad diversity of seafloor ecosystems(3,4). The factors controlling microbial activity and carbonate precipitation associated with the seepage of submarine fluid over geological time remain poorly constrained. Here, we characterize the petrology and geochemistry of rocks sampled from metre-size build-...

  7. 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

  8. 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.

  9. The metallurgical integrity of the frit vent assembly diffusion bond

    International Nuclear Information System (INIS)

    Iridium alloy clad vent sets (CVSs) are now being made by Energy Systems at the Oak Ridge Y-12 Plant. These CVSs are being made for the US Department of Energy's (NE-53) General Purpose Heat Source- Radioisotope Thermoelectric Generator (GPHS-RTG) program, which is to supply electrical power for the National Aeronautics and Space Administration's Cassini mission to Saturn. A GPHS-RTG has 72 CVSs. Each CVS encapsulates one 238PuO2 fuel pellet. The helium gas produced from the alpha decay of the 238Pu is vented through a nominal 0.45-mm-diam hole in the vent cup of each CVS. A frit vent assembly that is electron beam welded over the vent hole allows helium gas to escape but prevents plutonia fines from exiting. The metallurgical integrity of frit vent assemblies produced by Martin Marietta Energy Systems, Inc. (Energy Systems) were compared with those produced earlier by EG ampersand G-Mound Applied Technology, Inc. (EG ampersand G-MAT). Scanning electron microscope (SEM) photographs were taken (at magnifications of from 126X to 1,000X) of the starting frit vent powder and the diffusion-bonded powder in finished frit vent assemblies produced by Energy Systems and EG ampersand G-MAT. Frit vent assemblies also were metallographically prepared and visually examined/photographed at magnifications of from 50X to 1,000X. The SEM and metallographic examinations of the particle-to-particle and particle-to-foil component diffusion bonds indicated that the Energy Systems-produced and EG ampersand G-MAT-produced frit vent assemblies have comparable metallurgical integrity. Statistical analysis of the Energy Systems production data shows that the frit vent manufacturing yield is 91%

  10. 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.

  11. 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.)

  12. 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.

  13. 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.

  14. Numerical analysis of flow and heat transfer characteristics in solar chimney power plants with energy storage layer

    International Nuclear Information System (INIS)

    Numerical simulations have been performed to analyze the characteristics of heat transfer and air flow in the solar chimney power plant system with an energy storage layer. Different mathematical models for the collector, the chimney and the energy storage layer have been established, and the effect of solar radiation on the heat storage characteristic of the energy storage layer has been analyzed. The numerical simulation results show that: (1) the heat storage ratio of the energy storage layer decreases firstly and then increases with the solar radiation increasing from 200 W/m2 to 800 W/m2; (2) the relative static pressure decreases while the velocity increases significantly inside the system with the increase of solar radiation; (3) the average temperature of the chimney outlet and the energy storage layer may increase significantly with the increase of solar radiation. In addition, the temperature gradient of the storage medium may increase, which results in an increase of energy loss from the bottom of the energy storage layer

  15. 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.

  16. 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.

  17. 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...

  18. 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...

  19. 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...

  20. 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...

  1. 46 CFR 56.50-85 - Tank-vent piping.

    Science.gov (United States)

    2010-10-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PIPING SYSTEMS AND... tanks, need be fitted with only one vent pipe, but tanks having a comparatively large surface shall be... position is not less than the inlet area of the vent pipe to which the valve is connected. (ii) A...

  2. 46 CFR 119.450 - Vent pipes for fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... fill pipe if the tank is filled under pressure. (c) The discharge ends of fuel tank vent pipes must... be fitted with a pipe connected to the highest point of the tank. (b) The minimum net cross sectional area of the vent pipe for diesel fuel tanks must be as follows: (1) Not less than the cross...

  3. 46 CFR 182.450 - Vent pipes for fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... fill pipe if the tank is filled under pressure. (d) The discharge ends of fuel tank vent pipes must... by reference; see 46 CFR 175.600), or 33 CFR 183, subpart J, or with diesel fuel tank vents built in accordance with ABYC H-33 (incorporated by reference; see 46 CFR 175.600), will be considered as meeting...

  4. Thermodynamic Vent System Test in a Low Earth Orbit Simulation

    Science.gov (United States)

    VanOverbeke, Thomas J.

    2004-01-01

    A thermodynamic vent system for a cryogenic nitrogen tank was tested in a vacuum chamber simulating oxygen storage in low earth orbit. The nitrogen tank was surrounded by a cryo-shroud at -40 F. The tank was insulated with two layers of multi-layer insulation. Heat transfer into cryogenic tanks causes phase change and increases tank pressure which must be controlled. A thermodynamic vent system was used to control pressure as the location of vapor is unknown in low gravity and direct venting would be wasteful. The thermodynamic vent system consists of a Joule-Thomson valve and heat exchanger installed on the inlet side of the tank mixer-pump. The combination is used to extract thermal energy from the tank fluid, reducing temperature and ullage pressure. The system was sized so that the tank mixer-pump operated a small fraction of the time to limit motor heating. Initially the mixer used sub-cooled liquid to cool the liquid-vapor interface inducing condensation and pressure reduction. Later, the thermodynamic vent system was used. Pressure cycles were performed until steady-state operation was demonstrated. Three test runs were conducted at tank fills of 97, 80, and 63 percent. Each test was begun with a boil-off test to determine heat transfer into the tank. The lower tank fills had time averaged vent rates very close to steady-state boil-off rates showing the thermodynamic vent system was nearly as efficient as direct venting in normal gravity.

  5. Integral valve provides automatic relief and remote venting

    Science.gov (United States)

    Gilmore, R. F.

    1969-01-01

    In-line, pilot-operated, differential area, poppet type valve provides both automatic relief of a tank at a precise over-pressure and remote control of tank venting. Relief and vent operations are separate functions incorporated in an integral valve package.

  6. 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.

  7. 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

  8. 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.

  9. 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...

  10. 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…

  11. Experimental investigation into heating and airflow in trombe walls and solar chimneys

    International Nuclear Information System (INIS)

    Trombe Walls and solar chimneys are examples of passive solar air heating systems. However, the airflow and thermal efficiency characteristics of this type of system are not well understood, and partly for this reason, they are not commonly utilised. This paper reports on an experimental investigation into buoyancy-driven convection in a test rig designed to simulate the operation of a passive solar collector. The test rig comprised a vertical open-ended channel, approximately 1a square, heated from one side. The channel depth could be varied from 20mm to 110mm, and heating inputs varied from 200W to 1000W. Temperatures and airflow rates were measured and recorded, to characterise both steady-state and transient performance. The principal findings are: 1. Time constants (for heating)ranged typically between 30 and 70 minutes. 2. Flow regimes were mainly laminar (Reynolds number varing from ∼500 to ∼4000, depending on heat input and channel depth. 3. The thermal efficiency (as a solar collector and the heat transfer coefficient were functions of heat input, and were not depended on the channel depth. 4. The mass flow rate through the channel increased bath as the heat input increased and as the channel depth increased. The paper presents these findings and discusses their implications in more detail.(Author)

  12. Hydrothermal pyrite chimneys from the Ballynoe baryte deposit, Silvermines, County Tipperary, Ireland

    Science.gov (United States)

    Larter, R. C. L.; Boyce, A. J.; Russell, M. J.

    1981-08-01

    We report the discovery of pyrite tubes 0.1 to 20mm in diameter in the Ballynoe sedimentary baryte deposit. Well developed tubes comprise concentric layers of pyrite of contrasting crystal sizes 0.05 to 1 mm thick. An outer rim of crystalline baryte ⪕ 10mm thick commonly coats the tubes where these are not touching. The central canals contain myriad pyrite framboids. These tubes have characteristics in common with the chimney spires found on the East Pacific Rise at 21°N from which metal bearing solutions issue at temperatures of up to 380±30°C. Their presence carries the implication that the baryte deposit was not a distal facies of the Silvermines sedimentary pyritic zinc and lead ore, but was produced from local hydrothermal exhalations, though in a shallower part of the basin than the coeval sulphide deposits which had their own feeders. Some epigenetic mineralization may be awaiting discovery beneath the feeder sites at Ballynoe.

  13. 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

  14. 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,...

  15. 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

  16. 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

  17. Soil venting at a California site

    International Nuclear Information System (INIS)

    The development and evaluation of soil treatment technologies is being driven by regulatory demands, which often require or suggest that residual total petroleum hydrocarbon (TPH) concentrations in soil be reduced below 1000 mg/kg. In some areas this limit is as low as 100 mg/kg TPH; lower concentrations are mandated for other specific compounds. In situ soil venting, or vacuum extraction, is the focus of this paper. Typical components include: vapor extraction (recovery) wells installed within the vadose (unsaturated) zone, blowers or vacuum pumps, and vapor treatment systems. By applying a vacuum at the vapor extraction well, contaminant vapors are removed, the natural rate of volatilization in the soil is enhanced, and residual hydrocarbon concentrations are reduced. More complex systems may utilize surface seals, horizontal wells, and forced or passive air injection wells

  18. Design experiments for a vented containment

    International Nuclear Information System (INIS)

    A filtered containment venting system, operable late in 1985, is currently under installation at the Barsebaeck twin nuclear power station in Sweden. The filter unit, which communicates with the containments of both reactor units, but is separated from them by rupture discs, consists of a concrete bed, 40 m high and 20 m in diameter, filled with gravel of grain size 25-35 mm. The performance of the gravel bed under such accident conditions which might lead to an activation of this safeguard system has been the subject for investigation within the FILTRA project. These investigations have shown that the gravel bed acts as: an expansion volume for decreasing gas pressure and increasing gas residence time, a heat sink for condensing steam, an excellent filter medium for removing aerosols and elemental iodine, and a sump volume for collecting radioactive condensate. The results from iodine retention studies in gravel beds are mainly considered

  19. 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.

  20. Mortality table construction

    Science.gov (United States)

    Sutawanir

    2015-12-01

    Mortality tables play important role in actuarial studies such as life annuities, premium determination, premium reserve, valuation pension plan, pension funding. Some known mortality tables are CSO mortality table, Indonesian Mortality Table, Bowers mortality table, Japan Mortality table. For actuary applications some tables are constructed with different environment such as single decrement, double decrement, and multiple decrement. There exist two approaches in mortality table construction : mathematics approach and statistical approach. Distribution model and estimation theory are the statistical concepts that are used in mortality table construction. This article aims to discuss the statistical approach in mortality table construction. The distributional assumptions are uniform death distribution (UDD) and constant force (exponential). Moment estimation and maximum likelihood are used to estimate the mortality parameter. Moment estimation methods are easier to manipulate compared to maximum likelihood estimation (mle). However, the complete mortality data are not used in moment estimation method. Maximum likelihood exploited all available information in mortality estimation. Some mle equations are complicated and solved using numerical methods. The article focus on single decrement estimation using moment and maximum likelihood estimation. Some extension to double decrement will introduced. Simple dataset will be used to illustrated the mortality estimation, and mortality table.

  1. 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;...

  2. 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

  3. 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

  4. 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

  5. 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.

  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. 40 CFR Table 12 to Subpart Uuu of... - Initial Compliance With Organic HAP Emission Limits for Catalytic Cracking Units

    Science.gov (United States)

    2010-07-01

    ... the NSPS for carbon monoxide (CO) in 40 CFR 60.103 CO emissions from your catalyst regenerator vent or... initial compliance. 2. Not subject to the NSPS for CO in 40 CFR 60.103 a. CO emissions from your catalyst... Emission Limits for Catalytic Cracking Units 12 Table 12 to Subpart UUU of Part 63 Protection...

  8. TABLE TENNIS CLUB

    CERN Multimedia

    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...

  9. 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

  10. 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

  11. 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

  12. Dissolved gases in hydrothermal plumes from Artic vent fields

    OpenAIRE

    Stensland, Anne

    2013-01-01

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

  13. Fluid and gas fluxes from the Logatchev hydrothermal vent area

    OpenAIRE

    Schmale, Oliver; Walter, Maren; Schneider von Deimling, Jens; Sültenfuß, Jürgen; Walker, Sharon; Rehder, Gregor; Keir, Robin

    2012-01-01

    The Logatchev hydrothermal field at 14°45′N on the MAR is characterized by gas plumes that are enriched in methane and helium compared to the oceanic background. We investigated CH4 concentration and δ13C together with δ3He in the water column of that region. These data and turbidity measurements indicate that apart from the known vent fields, another vent site exists northeast of the vent field Logatchev 1. The distribution of methane and 3He concentrations along two sections were used in co...

  14. 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.

  15. 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

  16. Mathematical modelling and validation of the drying process in a Chimney-Dependent Solar Crop Dryer

    International Nuclear Information System (INIS)

    Highlights: ► The simulation code predicts temperatures to within 1.5% of recorded data. ► The ventilation is predicted to within 5% accuracy. ► Effects of heat inertia cause the actual drying path to deviate from the simulated path. ► The two paths converge in the end with a final moisture content prediction to within 10%. ► The simulation code can be used to compare and refine the dryer designs for optimum drying performance. - Abstract: A simulation procedure describing the drying process within a Chimney-Dependent Solar Crop Dryer (CDSCD) has been developed. The simulation follows the authors’ experimental work on the effect of varying drying chamber roof inclination on the ventilation and drying processes, and their work on the development of simulation code to help optimise ventilation in such dryers. The current paper presents the modelling and subsequent validation of the drying process inside the dryer, to come out with a design tool for the CDSCD. The work considers the height of the crop shelf above the drying-chamber base, crop resistance to airflow and the shading on the drying-chamber base and their effects on the drying process. The under-load condition temperatures and velocities are predicted to within a relative difference of 1.5% and 10%, respectively of the observed values. Even though the heat inertia of the physical model causes deviation between the predicted drying path and the observed drying path, the two paths tend to converge at the end of each drying cycle, with a general prediction to within 10% relative difference of the observed crop moisture content. The validation results show that the simulation code can serve as an effective tool for comparing and refining the designs of the CDSCD for optimum drying performance

  17. A cost-benefit analysis of power generation from commercial reinforced concrete solar chimney power plant

    International Nuclear Information System (INIS)

    Highlights: • We develop an economic model different from related models. • We evaluate the initial investment cost of a plant built in northwest China. • We analyze the cost and benefit of a plant built in northwest China. • By the sensitivity analysis, we examine the sensitivity of TNPV to many parameters. - Abstract: This paper develops a model different from existing models to analyze the cost and benefit of a reinforced concrete solar chimney power plant (RCSCPP) built in northwest China. Based on the model and some assumptions for values of parameters, this work calculates total net present value (TNPV) and the minimum electricity price in each phase by dividing the whole service period into four phases. The results show that the minimum electricity price in the first phase is higher than the current market price of electricity, but the minimum prices in the other phases are far less than the current market price. The analysis indicates that huge advantages of the RCSCPP over coal-fired power plants can be embodied in phases 2–4. In addition, the sensitivity analysis performed in this paper discovers TNPV is very sensitive to changes in the solar electricity price and inflation rate, but responds only slightly to changes in carbon credits price, income tax rate and interest rate of loans. Our analysis predicts that RCSCPPs have very good application prospect. To encourage the development of RCSCPPs, the government should provide subsidy by setting higher electricity price in the first phase, then lower electricity price in the other phases

  18. 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)

  19. 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... venting to any combustion control device, and thus make the batch process vent, aggregate batch...

  20. 40 CFR 63.485 - Continuous front-end process vent provisions.

    Science.gov (United States)

    2010-07-01

    ....487(e)(2) for batch front-end process vents and aggregate batch vent streams. (p) If any gas stream... halogenated continuous front-end process vent stream was controlled by a combustion device prior to June 12... continuous front-end process vents at new and existing affected sources producing an elastomer using a...

  1. 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...

  2. 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...

  3. 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

  4. 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.

  5. 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…

  6. Table Tennis Club

    CERN Multimedia

    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

  7. 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

  8. 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

  9. 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

  10. Experimental Study and Optimization of Thermoelectricity-Driven Autonomous Sensors for the Chimney of a Biomass Power Plant

    Science.gov (United States)

    Rodríguez, A.; Astrain, D.; Martínez, A.; Aranguren, P.

    2014-06-01

    In the work discussed in this paper a thermoelectric generator was developed to harness waste heat from the exhaust gas of a boiler in a biomass power plant and thus generate electric power to operate a flowmeter installed in the chimney, to make it autonomous. The main objective was to conduct an experimental study to optimize a previous design obtained after computational work based on a simulation model for thermoelectric generators. First, several places inside and outside the chimney were considered as sites for the thermoelectricity-driven autonomous sensor. Second, the thermoelectric generator was built and tested to assess the effect of the cold-side heat exchanger on the electric power, power consumption by the flowmeter, and transmission frequency. These tests provided the best configuration for the heat exchanger, which met the transmission requirements for different working conditions. The final design is able to transmit every second and requires neither batteries nor electric wires. It is a promising application in the field of thermoelectric generation.

  11. SULZER containment venting filter verification experiments

    International Nuclear Information System (INIS)

    During the period 1988-1991 SULZER THERMTEC AG (Sulzer) developed an aerosol filter system to be used for the venting of the containment of a nuclear power plant in case of a severe accident as postulated in a light water reactor. This filter system should avoid containment failure and limit the activity release from the containment into the environment. A series of aerosol tests, to extend the initial developmental test program performed at Sulzer, was conducted at the Laboratory for Safety and Accident Research (LSU) at the Paul Scherrer Institut (PSI). The objectives of the PSI-Sulzer test program were to determine how radioactive aerosol particles, which were simulated by use of inactive tin dioxide particles, would be filtered under conditions more extreme than those expected to occur inside a light water reactor containment during a severe accident. The particles were generated using an evaporation and condensation technique. The tests were conducted under following range of boundary conditions: inlet pressure: 1.6 to 5 bar; inlet total gas flow: 140 to 583 kg/h; steam fraction: 43 to 54 % and aerosol concentration: 0.2 to 15.4 g/m3. The filter system was shown to achieve minimum decontamination factors between 46300 and 195000 depending on the filter configuration. A special test indicated that aerosol release from the filter system, due to resuspension from highly contaminated filter water, did not take place. The main conclusions of the program and the results of the tests conducted between September 1993 and August 1994 are presented. (author) 7 figs., 2 tabs., 1 ref

  12. SULZER containment venting filter verification experiments

    Energy Technology Data Exchange (ETDEWEB)

    Guentay, S.; Suckow, D.; Leute, H.; Knuchel, H.; Schuett, H.; Winkler, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1996-01-01

    During the period 1988-1991 SULZER THERMTEC AG (Sulzer) developed an aerosol filter system to be used for the venting of the containment of a nuclear power plant in case of a severe accident as postulated in a light water reactor. This filter system should avoid containment failure and limit the activity release from the containment into the environment. A series of aerosol tests, to extend the initial developmental test program performed at Sulzer, was conducted at the Laboratory for Safety and Accident Research (LSU) at the Paul Scherrer Institut (PSI). The objectives of the PSI-Sulzer test program were to determine how radioactive aerosol particles, which were simulated by use of inactive tin dioxide particles, would be filtered under conditions more extreme than those expected to occur inside a light water reactor containment during a severe accident. The particles were generated using an evaporation and condensation technique. The tests were conducted under following range of boundary conditions: inlet pressure: 1.6 to 5 bar; inlet total gas flow: 140 to 583 kg/h; steam fraction: 43 to 54 % and aerosol concentration: 0.2 to 15.4 g/m{sup 3}. The filter system was shown to achieve minimum decontamination factors between 46300 and 195000 depending on the filter configuration. A special test indicated that aerosol release from the filter system, due to resuspension from highly contaminated filter water, did not take place. The main conclusions of the program and the results of the tests conducted between September 1993 and August 1994 are presented. (author) 7 figs., 2 tabs., 1 ref.

  13. Comparison Of Vented And Absolute Pressure Transducers For Water-Level Monitoring In Hanford Site Central Plateau Wells

    International Nuclear Information System (INIS)

    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.

  14. 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.

  15. 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)).

  16. Tectonic context of fluid venting at the toe of the eastern Nankai accretionary prism: Evidence for a shallow detachment fault

    Science.gov (United States)

    Chamot-Rooke, N.; Lallemant, S. J.; Le Pichon, X.; Henry, P.; Sibuet, M.; Boulègue, J.; Foucher, J.-P.; Furuta, T.; Gamo, T.; Glaçon, G.; Kobayashi, K.; Kuramoto, S.; Ogawa, Y.; Schultheiss, P.; Segawa, J.; Takeuchi, A.; Tarits, P.; Tokuyama, H.

    1992-04-01

    During the Kaiko-Nankai diving cruise the peak of the venting activity was located near the top of the very first anticline. The most prominent morphological feature between the mid-slope (3870 m) and the apex of the fold (3770 m) is a 20 m high cliff cutting through subhorizontal massive mudstones affected by numerous joints. The trend of this scarp is oblique to the fold axis and structurally controlled along two sharply defined NNE-SSE and E-W directions. Fresh talus and blocks found locally suggest active tectonics and recent erosion. Intense deformation is evident from strongly tilted strata restricted to the base of the cliff that we interpret as an upslope thrust. At the scale of Seabeam mapping, this thrust can be followed eastward for more than 5 km along the 3820 m isobath. Two seismic lines recorded during one of the pre-site surveys show deformation at shallow depth, including small-scale folding and thrusting affecting only the wedge-shaped top sequence. Deeper layers can be traced continuously below this sequence. We conclude that the boundary between the "piggy-back" basin and the frontal fold turbidites acts as a shallow detachment fault, and interpret the base of the cliff as the outcrop of the fault. Dense colonies ofCalyptogena clams and strongly nonlinear thermal gradients locate the major peak of fluid activity at the edge of the plateau above the main cliff. Scattered biological colonies as well as white bacterial mats and cemented chimneys were also found in a narrow belt along the base of the cliff. Fluid activity is thus closely related to the shallow detachment fault, fluid being expelled both at the outcrop of the fault and above it through the overlying strata, possibly using the very dense joint network.

  17. 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

  18. Zero-Gravity Vortex Vent and PVT Gaging System

    Science.gov (United States)

    Downey, M. G.; Trevathan, J. T.

    1989-01-01

    Space Station and satellite reservicing will require the ability to vent gas on orbit from liquid supply or storage tanks and to gage liquid quantity under microgravity conditions. In zero gravity, (zero-g) the vortex vent is capable of venting gas from a tank of liquid containing gas randomly distributed as bubbles. The concept uses a spinning impeller to create centrifugal force inside a vortex tube within a tank. This creates a gas pocket and forces the liquid through a venturi and back into the tank. Gas is then vented from the gas pocket through a liquid detector and then out through an exhaust port. If the liquid detector senses liquid in the vent line, the fluid is directed to the low-pressure port on the venturi and is returned to the tank. The advantages of this system is that it has no rotating seals and is compatible with most corrosive and cryogenic fluids. A prototype was designed and built at the NASA Johnson Space Center and flown on the KC-135 zero-g aircraft. During these test flights, where microgravity conditions are obtained for up to 30 sec, the prototype demonstrated that less than 0.10 percent of the volume of fluid vented was liquid when the tank was half full of liquid. The pressure volume temperature (PVT) gaging system is used in conjunction with the vortex vent to calculate the amount of liquid remaining in a tank under microgravity conditions. The PVT gaging system is used in conjunction with the vortex vent to gage liquid quantity in zero or low gravity. The system consists of a gas compressor, accumulator, and temperature and pressure instrumentation. To measure the liquid in a tank a small amount of gas is vented from the tank to the compressor and compressed into the accumulator. Pressure and temperature in the tank and accumulator are measured before and after the gas transfer occurs. Knowing the total volume of the tank, the volume of the accumulator, the volume of the intermediate lines, and initial and final pressures and

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

    International Nuclear Information System (INIS)

    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.

  20. Steam chugging analysis in single-vent vapor injection

    Science.gov (United States)

    Lee, C. K. B.; Chan, C. K.

    1982-01-01

    A complete cycle of the periodic steam chugging phenomenon is analyed. Steam velocity and pressure variations in the vent are described by one-dimensional conservation equations. This is coupled either to the water slug model when water is in the vent, or, the infinite pool spherical bubble model at the vent exit during bubble growth. An isolated spherical bubble model is used for computing the collapse pressures. Comparisons of the model predictions with the UCLA 1/12-scale and the Japan 1/6-scale data indicate that the vent-pipe model predicts the vent-clearing times and the bubble growth times well. In addition, the predicted maximum chugging heights compared well with those measured in the Japan data. On bubble collapse pressures, the comparison with the spherical bubble model predictions is only fair. The model generally overpredicts the magnitude of the spikes. On examining the effects of pool subcooling and steam mass flux, general agreement is found between the predicted trends and those measured.

  1. 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)

  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. 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...

  5. Solar chimney for the natural ventilation of buildings: simulation and mediation; Chimenea solar para la ventilacion natural de edificios: simulacion y mediacion

    Energy Technology Data Exchange (ETDEWEB)

    Lanceta, D.; Llorente, J.

    2008-07-01

    In this article, the first part of a research project about the modelling of a solar chimney is presented. In this first part, the average ventilation flows measured in an experimental installation have been compared to the results obtained by CFD (Computational Fluid Dynamics) simulations. In order to do so, a solar chimney with a cross-section of 0.78 m x 0.156 m, height 3,6 m, has been constructed. The chimney consists of a glass surface oriented towards the south. The internal (absorber) surface is made of a copper plate, which has been painted black in order to increase the solar absorption. The chimney is connected to a room measuring 5 m x 2.5 m x 2.5 m, from where it extracts air. The comparison of the results obtained by measurements with those obtained by CFD simulations show that computational tools are accurate enough to predict the behaviour of natural buoyancy in this kind of installations. (Author)

  6. Examining potential benefits of combining a chimney with a salinity gradient solar pond for production of power in salt affected areas

    Energy Technology Data Exchange (ETDEWEB)

    Akbarzadeh, Aliakbar; Johnson, Peter; Singh, Randeep [Energy Conservation and Renewable Energy Group, School of Aerospace Mechanical and Manufacturing Engineering, RMIT University, P.O. Box 71, Bundoora 3083, Vic. (Australia)

    2009-08-15

    The concept of combining a salinity gradient solar pond with a chimney to produce power in salt affected areas is examined. Firstly the causes of salinity in salt affected areas of northern Victoria, Australia are discussed. Existing salinity mitigation schemes are introduced and the integration of solar ponds with those schemes is discussed. Later it is shown how a solar pond can be combined with a chimney incorporating an air turbine for the production of power. Following the introduction of this concept the preliminary design is presented for a demonstration power plant incorporating a solar pond of area 6 hectares and depth 3 m with a 200 m tall chimney of 10 m diameter. The performance, including output power and efficiency of the proposed plant operating in northern Victoria is analysed and the results are discussed. The paper also discusses the overall advantages of using a solar pond with a chimney for production of power including the use of the large thermal mass of a solar pond as a practical and efficient method of storing collected solar energy. (author)

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

    Science.gov (United States)

    Gollner, Sabine; Govenar, Breea; Arbizu, Pedro Martinez; Mills, Susan; Le Bris, Nadine; Weinbauer, Markus; Shank, Timothy M.; Bright, Monika

    2015-12-01

    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 this study, we monitor and compare the recovery of insular, highly productive vent communities and vent-proximate basalt communities following a volcanic eruption that destroyed almost all existing communities at the East Pacific Rise, 9°50‧N in 2006. To study the recovery patterns of the benthic communities, we placed settlement substrates at vent sites and their proximate basalt areas and measured the prokaryotic abundance and compared the meio- and macrofaunal species richness and composition at one, two and four years after the eruption. In addition, we collected samples from the overlying water column with a pelagic pump, at one and two years after the volcanic eruption, to determine the abundance of potential meiofauna colonisers. One year after eruption, mean meio- and macrofaunal abundances were not significantly different from pre-eruption values in vent habitats (meio: 8-1838 ind. 64 cm-2 in 2006; 3-6246 ind. 64 cm-2 in 2001/02; macro: 95-1600 ind. 64 cm-2 in 2006; 205-4577 ind. 64 cm-2 in 2001/02) and on non-vent basalt habitats (meio: 10-1922 ind. 64 cm-2 in 2006; 8-328 ind. 64 cm-2 in 2003/04; macro: 14-3351 ind. 64 cm-2 in 2006; 2-63 ind. 64 cm-2 in 2003/04), but species recovery patterns differed between the two habitat types. In the vent habitat, the initial community recovery was relatively quick but incomplete four years after eruption, which may be due to the good dispersal capabilities of vent endemic macrofauna and vent endemic dirivultid copepods. At vents, 42% of the pre-eruption meio- and 39% of macrofaunal species had returned. In addition, some new species not evident prior to the eruption were found. At the tubeworm site Tica, a total of 26

  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. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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

  14. 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.)

  15. 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

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 40 CFR 63.1104 - Process vents from continuous unit operations: applicability assessment procedures and methods.

    Science.gov (United States)

    2010-07-01

    ... vent. (iv) Design analysis based on accepted chemical engineering principles, measurable process...) Sampling site selection method. Method 1 or 1A of 40 CFR part 60, appendix A, as appropriate, shall be used... rates, halogenated process vent determinations, process vent TRE index values, and...

  1. 40 CFR 63.486 - Batch front-end process vent provisions.

    Science.gov (United States)

    2010-07-01

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

  2. 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...

  3. 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...

  4. 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...

  5. 40 CFR 63.645 - Test methods and procedures for miscellaneous process vents.

    Science.gov (United States)

    2010-07-01

    ..., gram per gram-mole. Qs=Vent stream flow rate, dry standard cubic meters per minute, at a temperature of... to express units of CTOC, gram per gram-mole. Qs=Vent stream flow rate, dry standard cubic meters per... process vent TOC mass flow rate is less than 33 kilograms per day for an existing source or less than...

  6. 40 CFR 63.487 - Batch front-end process vents-reference control technology.

    Science.gov (United States)

    2010-07-01

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

  7. 40 CFR 63.1407 - Non-reactor batch process vent provisions.

    Science.gov (United States)

    2010-07-01

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

  8. Periodic table of elements

    International Nuclear Information System (INIS)

    Following a recommendation by the International Union for Pure and Applied Chemistry (IUPAC), the groups of the periodic table shall be numbered from 1 to 18, instead of I to VIII as before. The recommendations has been approved of by the Committee on Nomenclature of the American Chemical Society. The new system abandons the distinction between main groups (a) and auxiliary groups (b), which in the past frequently has been the reason for misunderstandings between European and American chemists, due to different handling. The publishing house VCH Verlagsgesellschaft recently produced a new periodic table that shows the old and the new numbering system together at a glance, so that chemists will have time to get familiar with the new system. In addition the new periodic table represents an extensive data compilation arranged by elements. The front page lists the chemical properties of elements, the back page their physical properties. (orig./EF)

  9. 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.

  10. Combustion gas moisture generated by vent-free fireplaces

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, M. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Energy Technology Centre, Sustainable Buildings and Community Group

    2007-05-15

    Gas fireplaces are gaining in popularity for use in residential applications because they are clean burning and do not rely on wood delivery services. This article addressed the health and safety concerns regarding the use of vent-free fireplaces in increasingly more airtight homes. Vent-free units are appealing because they do not require vents, which can be a challenge to fit into urban homes. Although their use is allowed in the United States and Australia, Canadian standards do not permit vent-free gas-fired appliances because the combustion gases dissipate into the house. Alternatives to natural gas include new alcohol-fuelled fireplaces which are touted as being environmentally sound since the denatured alcohol fuel is produced by the fermentation of sugars from agricultural and forestry products. EcoSmart is an Australian-developed vent-free fireplace currently marketed in Canada. The combustion byproducts include heat, steam and carbon dioxide. The life of the fire depends on the amount of fuel placed into the burner box. Once it has burned, there is nothing to clean. The thermal input is 13,000 BTUs. The new product does not fit any standards that exist for gas, oil or wood burning appliances. Testing has focused on CO/CO{sub 2} fuel consumption ratios, flame stability, ignition safety, heat output, combustion characteristics and operational features. However, it was cautioned that not every house has an adequate amount of air exchange to provide basic ventilation to meet occupant needs for healthy indoor air quality, nor enough air change to deal with combustion moisture and other gases from a vent-free appliance. Integrated Energy Systems Laboratories conducted an analysis to determine the effect on indoor air quality when alcohol or gas is burned. The combustion products of several different fuels were analyzed. It was shown that 506 g of water is produced for every 10,000 BTU of fuel, which is equivalent to 0.5 litres of water per hour. In addition, if

  11. Filtered atmospheric venting of light water reactor containments

    International Nuclear Information System (INIS)

    The aim of filtered venting is to improve the function of the reactor containment in connection with very severe accidents. By equipping the containment with a safety valve for pressure relief and allowing the released gases to pass through an effective filter, it should be possible to achieve a considerable protective effect. The work has involved detailed studies of the core meltdown sequence, how the molten core material runs out of the reactor vessel, what effect it has on concrete and other structures and how final cooling of the molten core material takes place. On the basis of previous Swedish studies, the project has chosen to study a filter concept that consists of a gravel bed of large volume. This filter plant shall not only retain the radioactive particles that escape from the containment through the vent line, but shall also condense the accompanying steam. After the government decided in 1981 that Barsebaeck was to be equipped with filtered venting and issued specifications regarding its performance, the project aimed at obtaining results that could be used to design and verify a plant for filtered venting at the Barsebaeck nuclear power station. As far as the other Swedish nuclear power plants at Oskarshamn, Ringhals and Forsmark are concerned, the results are only applicable to a limited extent. Additional studies are required for these nuclear power plants before the value of filtered venting can be assessed. Based on the results of experiments and analyses, the project has made a safety analysis with Barsebaeck as a reference plant in order to study how the introduction of filtered venting affects the safety level at a station. In summary, the venting function appears to entail a not insignificant reduction of risks for boiling water reactors of the Barsebaeck type. For a number of types of such very severe core accident cases, the filter design studied ensures a substantial reduction of the releases. However it has not been possible within the

  12. Table des figures

    OpenAIRE

    2015-01-01

    Figure n° 1 : Nombre de traités sur la culture des arbres fruitiers publiés en français à l’époque moderne 30 Figure n° 2 : Un exemple de plagiat, la vraie fausse nouvelle instruction pour la culture des figuiers 33 Figure n° 3 : Nombre d’espèces fruitières sélectionnées dans les traités horticoles parisiens (xviie-xviiie siècles) 65 Figure n° 4 : Nombre d’espèces fruitières proposées à la vente dans les catalogues des pépiniéristes parisiens (xviiie-début xixe s.) 65 Figure n° 5 : Les ustens...

  13. Investigation of extractable organic compounds in deep-sea hydrothermal vent fluids along the Mid-Atlantic Ridge

    Science.gov (United States)

    McCollom, Thomas M.; Seewald, Jeffrey S.; German, Christopher R.

    2015-05-01

    The possibility that deep-sea hydrothermal vents may contain organic compounds produced by abiotic synthesis or by microbial communities living deep beneath the surface has led to numerous studies of the organic composition of vent fluids. Most of these studies have focused on methane and other light hydrocarbons, while the possible occurrence of more complex organic compounds in the fluids has remained largely unstudied. To address this issue, the presence of higher molecular weight organic compounds in deep-sea hydrothermal fluids was assessed at three sites along the Mid-Atlantic Ridge that span a range of temperatures (51 to >360 °C), fluid compositions, and host-rock lithologies (mafic to ultramafic). Samples were obtained at several sites within the Lucky Strike, Rainbow, and Lost City hydrothermal fields. Three methods were employed to extract organic compounds for analysis, including liquid:liquid extraction, cold trapping on the walls of a coil of titanium tubing, and pumping fluids through cartridges filled with solid phase extraction (SPE) sorbents. The only samples to consistently yield high amounts of extractable organic compounds were the warm (51-91 °C), highly alkaline fluids from Lost City, which contained elevated concentrations of C8, C10, and C12n-alkanoic acids and, in some cases, trithiolane, hexadecanol, squalene, and cholesterol. Collectively, the C8-C12 acids can account for about 15% of the total dissolved organic carbon in the Lost City fluids. The even-carbon-number predominance of the alkanoic acids indicates a biological origin, but it is unclear whether these compounds are derived from microbial activity occurring within the hydrothermal chimney proximal to the site of fluid discharge or are transported from deeper within the system. Hydrothermal fluids from the Lucky Strike and Rainbow fields were characterized by an overall scarcity of extractable dissolved organic compounds. Trace amounts of aromatic hydrocarbons including

  14. Climate change : transportation table

    International Nuclear Information System (INIS)

    The Kyoto Protocol sets greenhouse gas (GHG) reduction targets for the post-2000 period. If ratified, Canada will be committed to reduce emissions of GHGs by 6 per cent below 1990 levels during the period 2008-2012. A recommended national strategy is to establish 'issue tables' that will advise the Ministers of Energy and Environment on preferred options to reach the Kyoto target and to identify early actions that can be taken. The 'Transportation Table' which is the focus of this paper, is one of the 15 sectoral tables. The Transportation Table will identify by July 1999, specific measures to mitigate GHG emissions from Canada's transportation sector. Currently, GHG emissions from the transportation sector are predicted to be 27 per cent above 1990 levels by 2010. Fuel taxes, emissions trading, and research into improved vehicle technologies and automotive fuels are some of the recommended options which can help reduce emissions trading from the transportation sector. Studies are underway to deal with emissions from transport in two sub-groups, freight and passenger. 1 fig

  15. A Modern Periodic Table.

    Science.gov (United States)

    Herrenden-Harker, B. D.

    1997-01-01

    Presents a modern Periodic Table based on the electron distribution in the outermost shell and the order of filling of the sublevels within the shells. Enables a student to read off directly the electronic configuration of the element and the order in which filling occurs. (JRH)

  16. 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.…

  17. 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。

  18. 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 ...

  19. 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

  20. 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 ...

  1. 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).

  2. 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...

  3. 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

  4. Analysis of containment venting following a core damage at a BWR Mark I using THALES-2

    International Nuclear Information System (INIS)

    Analysis of containment venting following a core damage at a boiling water reactor (BWR) Mark I using THALES-2 was performed. In this analysis, the effect of various parameters, namely, the areas of the vent path, containment venting pressure, and accident sequences on the containment thermodynamic response, and radionuclide transport and release in the containment venting at a BWR was examined. The code THALES-2B developed by the Japan Atomic Energy Research Institute (JAERI) was used in this analysis. The model plant in this analysis was the Browns Ferry plant. From this analysis was found that the 4-inch pipe of containment venting flow path is sufficient to maintain the containment pressure in the specified range if the containment was pressurized by the decay heat power. The entrainment by the pool swelling as well as by the flashing was not occurred during the containment venting. The source terms are not sensitive to the variation of containment venting flow path area. The containment venting pressure operation setting point has important rule in the containment venting. In the containment venting, the source terms are not sensitive to the accident sequence, except for Sr source term. In order to get better understanding on the containment venting strategy, the following analyses are necessary. Analyses of accident sequence which has a high power such as anticipated transient without scram are necessary, as well as analyses of accident sequence which pressurize the containment before the core damage. (author)

  5. 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.

  6. 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.

  7. Aggregation Algorithms in Heterogeneous Tables

    OpenAIRE

    Titus Felix FURTUNA; Ivan, Ion; Marian DARDALA

    2006-01-01

    The heterogeneous tables are most used in the problem of aggregation. A solution for this problem is to standardize these tables of figures. In this paper, we proposed some methods of aggregation based on the hierarchical algorithms.

  8. 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.

  9. Design of lift positional table

    OpenAIRE

    Bartel, Jindřich

    2015-01-01

    This bachelor´s thesis describes the design of a lift positional table for overcome the height difference between the two roller tracks. Weight of the load is 550 kg and height difference of roller tracks is 2000 mm. The aim is to suggest the type of power lifting, power lifting functional calculation, functional calculation of the driver tray pallets and determining the main dimensions of the lifting table. The Appendix contains technical drawings of the lifting table and the table frame.

  10. 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 ...

  11. 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

  12. 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...

  13. 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...

  14. 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.

  15. 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

  16. Shuttle Gaseous Hydrogen Venting Risk from Flow Control Valve Failure

    Science.gov (United States)

    Drummond, J. Philip; Baurle, Robert A.; Gafney, Richard L.; Norris, Andrew T.; Pellett, Gerald L.; Rock, Kenneth E.

    2009-01-01

    This paper describes a series of studies to assess the potential risk associated with the failure of one of three gaseous hydrogen flow control valves in the orbiter's main propulsion system during the launch of Shuttle Endeavour (STS-126) in November 2008. The studies focused on critical issues associated with the possibility of combustion resulting from release of gaseous hydrogen from the external tank into the atmosphere during assent. The Shuttle Program currently assumes hydrogen venting from the external tank will result in a critical failure. The current effort was conducted to increase understanding of the risk associated with venting hydrogen given the flow control valve failure scenarios being considered in the Integrated In-Flight Anomaly Investigation being conducted by NASA.

  17. 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.

  18. Containment venting analysis for the Peach Bottom Atomic Power Station

    International Nuclear Information System (INIS)

    The extent to which containment venting is an effective means of preventing or mitigating the consequences of overpressurization during severe accidents was evaluated for the Peach Bottom Atomic Power Station Units 2 and 3 (boiling water reactors with Mark I containments). Detailed analyses were conducted on operator performance, equipment performance, and the physical phenomenology for three severe accident sequences currently identified as being important contributors to risk. The results indicate that containment venting can be effective in reducing risk for several classes of severe accidents but, based on procedures in draft form and equipment in place at the time of the analyses, has limited potential for further reducing the risk for severe accidents currently identified as being important contributors to the risk for Peach Bottom

  19. 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

  20. Numerical study of opposing mixed convection in a vented enclosure

    OpenAIRE

    Rahman, M M; Alim, M. A; M. A. H. Mamun; M. K. Chowdhury; A. K. M. S. Islam

    2007-01-01

    A numerical study has been performed on mixed convection in a vented enclosure by finite element method. An external fluid flow enters the enclosure through an opening in the left vertical wall and exits from another fixed opening in the right vertical wall. Various inlet port configurations are extensively studied with the change of governing parameters. For mixed convection, the significant parameters are Grashof number (Gr), Richardson number (Ri) and Reynolds number (Re) by which differen...

  1. 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.

  2. 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...

  3. 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.

  4. 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.

  5. Table Tennis Club

    CERN Multimedia

    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...

  6. 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.

  7. 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.

  8. Crystal Structure and Thermoelectric Properties of the Incommensurate Chimney-Ladder Compound VGeγ (γ ~1.82)

    Science.gov (United States)

    Hamada, Haruki; Kikuchi, Yuta; Hayashi, Kei; Miyazaki, Yuzuru

    2016-03-01

    A single-phase sample of a Nowotny chimney-ladder phase known as V17Ge31 has been prepared and its modulated crystal structure has been determined by means of a (3+1)-dimensional superspace approach. As in the case of higher manganese silicides (HMSs) MnSiγ, the compound consists of two tetragonal subsystems of [V] and [Ge] with an irrational c-axis ratio γ = c_{{V}}/c_{{Ge}} ˜ 1.82, and hence the structure formula is represented as VGe γ . As expected from the valence electron count estimated from the refined γ, the present germanide exhibits a metallic behavior with the electrical conductivity σ = 6.25 × 103 S/cm and the Seebeck coefficient S = 10.2 μV/K at 900 K. The resulting thermoelectric power factor of S^2σ = 6.56 × 10-5 W/mK2 and the dimensionless figure-of-merit, ZT, = 3.7 × 10-3 at 900 K demonstrate that the germanide is not a promising thermoelectric material. However, as the determined lattice thermal conductivity is comparable to that of HMSs, thermoelectric properties can be maximized through the partial substitution of V with group 6-8 elements to decrease hole carrier concentration.

  9. Thoracic aortic stent-graft placement combined with left subclavian artery 'chimney operation': therapeutic analysis of 15 cases with insufficient proximal anchor area

    International Nuclear Information System (INIS)

    Objective: To discuss the strategies for the management of insufficient proximal anchoring area during the performance of transluminal stent-graft placement (TSGP), and to evaluate the feasibility of intentional coverage of the left subclavian artery (LSA) together with left subclavian artery stent-graft placement by using 'chimney operation' technique. Methods: A total of 15 patients with thoracic aortic diseases complicated by insufficient proximal anchoring area, who were encountered in authors' hospital during the period from Dec. 2009 to April 2011, were enrolled in this study. The clinical data were retrospectively analyzed. The thoracic aortic diseases included aortic dissection (n=6), aortic pseudoaneurysm (n=1), aortic aneurysm (n=4) and penetrating ulcer (n=4). Of the 15 patients, the distance between the lesion and LSA anchoring site 15 mm in 2. TSGP was carried out. The ostium of LSA was intentionally and completely covered by thoracic aortic stent-graft and left subclavian artery stent-graft placement was subsequently performed. The patients were kept under observation for symptoms of cerebral and upper limb ischemia. The postoperative complications such as endoleak and the patency of LSA were assessed with angiography. Results: Thoracic aortic stent-graft placement was successfully carried out in all 15 patients. In addition, one 'chimney' stent was properly implanted in LSA in each patient. After the procedure, no complications of nervous system or severe ischemia of upper extremity occurred. Follow-up examinations performed between 5 days to 3 months after the treatment revealed that the aortic stent-graft remained in stable condition and no type Ⅰ endoleak occurred, meanwhile the blood flow in 'chimney' stent was unobstructed. Conclusion: Intentional LSA coverage with 'chimney operation' can expand the applicability of TSGP with high tolerability. It is especially useful for patients with left vertebral artery blood supply dominance or with

  10. 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

  11. 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

  12. 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.

  13. 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.

  14. Dynamics of hydrocarbon vents: Focus on primary porosity

    Science.gov (United States)

    Johansen, C.; Shedd, W.; Abichou, T.; Pineda-Garcia, O.; Silva, M.; MacDonald, I. R.

    2012-12-01

    This study investigated the dynamics of hydrocarbon release by monitoring activity of a single vent at a 1215m deep site in the Gulf of Mexico (GC600). An autonomous camera, deployed by the submersible ALVIN, was programmed to capture a close-up image every 4 seconds for approximately 3.5 hours. The images provided the ability to study the gas hydrate outcrop site (that measured 5.2x16.3cm3) in an undisturbed state. The outcrop included an array of 38 tube-like vents through which dark brown oil bubbles are released at a rate ranging from 8 bubbles per minute to 0 bubbles per minute. The average release of bubbles from all the separate vents was 59.5 bubbles per minute, equating the total volume released to 106.38cm per minute. The rate of bubble release decreased toward the end of the observation interval, which coincided approximately with the tidal minimum. Ice worms (Hesiocaeca methanicola, Desbruyères & Toulmond, 1998) were abundant at the vent site. The image sequence showed the ice-worms actively moving in and out of burrows in the mound. It has been speculated that Hesiocaeca methanicola contribute to gas hydrate decomposition by creating burrows and depressions in the gas hydrate matrix (Fisher et al, 2000). Ice worm burrows could generate pathways for the passage of oil and gas through the gas hydrate mound. Gas hydrates commonly occur along active and/or passive continental margins (Kennicutt et al, 1988a). The release of oil and gas at this particular hydrocarbon seep site is along a passive continental margin, and controlled primarily by active salt tectonics as opposed to the movement of continental tectonic plates (Salvador, 1987). We propose a descriptive model governing the release of gas and oil from deep sub-bottom reservoirs at depths of 3000-5000m (MacDonald, 1998), through consolidated and unconsolidated sediments, and finally through gas hydrate deposits at the sea floor. The oil and gas escape from the source rock and/or reservoir through

  15. Turning the Tables.

    Science.gov (United States)

    Wright, Karen; Schroeder, Doris

    2016-04-01

    In bioethics, the concept of vulnerability is applied almost exclusively to research participants and patients. We turn the tables and apply the concept to nurses caring for anorexia nervosa (AN) sufferers. In doing so, and using results from a qualitative research study undertaken in the UK, we show that AN nurses face a significant probability of incurring identifiable harms (inauthentic relationships and nonreciprocal relationships). Some recommendations on how these harms can be avoided or mitigated are given, but further research is needed. PMID:26957447

  16. 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.

  17. 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...

  18. 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...

  19. Upstream petroleum industry flaring and venting report : Industry performance for year ending December 31, 2003

    International Nuclear Information System (INIS)

    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

  20. Chemolithotrophic Sulfur-Oxidizing Bacteria from the Galapagos Rift Hydrothermal Vents

    OpenAIRE

    Ruby, E. G.; Wirsen, C.O. (C.); Jannasch, H W

    1981-01-01

    Three distinct physiological types of sulfur-oxidizing bacteria were enriched and isolated from samples collected at several deep-sea hydrothermal vents (2,550 m) of the Galapagos Rift ocean floor spreading center. Twelve strains of the obligately chemolithotrophic genus Thiomicrospira were obtained from venting water and from microbial mats covering surfaces in the immediate vicinity of the vents. From these and other sources two types of obligately heterotrophic sulfur oxidizers were repeat...

  1. 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

  2. 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

  3. 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

  4. Deep-sea hydrothermal vents: potential hot spots for natural products discovery?

    Science.gov (United States)

    Thornburg, Christopher C; Zabriskie, T Mark; McPhail, Kerry L

    2010-03-26

    Deep-sea hydrothermal vents are among the most extreme and dynamic environments on Earth. However, islands of highly dense and biologically diverse communities exist in the immediate vicinity of hydrothermal vent flows, in stark contrast to the surrounding bare seafloor. These communities comprise organisms with distinct metabolisms based on chemosynthesis and growth rates comparable to those from shallow water tropical environments, which have been rich sources of biologically active natural products. The geological setting and geochemical nature of deep-sea vents that impact the biogeography of vent organisms, chemosynthesis, and the known biological and metabolic diversity of Eukarya, Bacteria, and Archaea, including the handful of natural products isolated to date from deep-sea vent organisms, are considered here in an assessment of deep-sea hydrothermal vents as potential hot spots for natural products investigations. Of critical importance too are the logistics of collecting deep vent organisms, opportunities for re-collection considering the stability and longevity of vent sites, and the ability to culture natural product-producing deep vent organisms in the laboratory. New cost-effective technologies in deep-sea research and more advanced molecular techniques aimed at screening a more inclusive genetic assembly are poised to accelerate natural product discoveries from these microbial diversity hot spots. PMID:20099811

  5. 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

  6. 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

  7. 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)

  8. 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

  9. Radioactivity: additional tables

    International Nuclear Information System (INIS)

    The following additional tables are presented to the annual report on radioactive discharges from the major establishments in the U.K.: 1) Radioactive gaseous effluent, trends in annual emissions, by site, (civil and M.O.D.) 2) Radioactive liquid effluent (radionuclides specified by authorisations), trends in annual discharges to surface and coastal waters: by site. 3) Liquid effluent (radionuclides not subject to separate limits): annual discharges to surface and coastal waters by site. 4) Isotopic composition of liquid effluent from CEGB stations, 1984. 5) Trends in the amount of radioactivity in waste dumped in the north-east Atlantic. 6) Trends in volume of waste disposed of at Drigg (by source of waste). 7) Solid waste: trends in volume disposed of and level of activity at some other disposal sites. 8) Radioactivity in samples of fish and shellfish: trends in concentrations. (UK)

  10. 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

  11. 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...

  12. 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.)

  13. 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.

  14. 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)

  15. 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...

  16. 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...

  17. 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.

  18. 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.

  19. 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.

  20. 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…

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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).

  6. Anaerobic Respiration on Tellurate and Other Metalloids in Bacteria from Hydrothermal Vent Fields in the Eastern Pacific Ocean

    OpenAIRE

    Csotonyi, Julius T.; Stackebrandt, Erko; Yurkov, Vladimir

    2006-01-01

    This paper reports the discovery of anaerobic respiration on tellurate by bacteria isolated from deep ocean (1,543 to 1,791 m) hydrothermal vent worms. The first evidence for selenite- and vanadate-respiring bacteria from deep ocean hydrothermal vents is also presented. Enumeration of the anaerobic metal(loid)-resistant microbial community associated with hydrothermal vent animals indicates that a greater proportion of the bacterial community associated with certain vent fauna resists and red...

  7. 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...

  8. 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

  9. 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.

  10. 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...

  11. Testing Geyser Models using Down-vent Data

    Science.gov (United States)

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

    2013-12-01

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

  12. 46 CFR 38.20-1 - Venting-T/ALL.

    Science.gov (United States)

    2010-10-01

    ... § 38.20-1 Venting—T/ALL. (a) Each safety relief valve installed on a cargo tank shall be connected to a... branch or header as provided for in the Table 38.20-1(b), and upon the total safety relief valve... such that the back pressure in the relief valve discharge lines shall not be more than 10 percent...

  13. Automation of BESSY scanning tables

    International Nuclear Information System (INIS)

    A micro processor M6800 is used for the automation of scanning and premeasuring BESSY tables. The tasks achieved by the micro processor are: 1. control of spooling of the four asynchronous film winding devices and switching on and off the 4 projections lamps, 2. pre-processing of the data coming from a bi-polar coordinates measuring device, 3. bi-directional interchange of informations between the operator, the BESSY table and the DEC PDP 11/34 mini computer controling the scanning operations, 4. control of the magnification on the table by swapping the projection lenses of appropriate focal lengths and the associated light boxes (under development). In connection with point 4, study is being made for the use of BESSY tables for accurate measurements (+/-5 microns), by encoding the displacements of the projections lenses. (orig.)

  14. 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...

  15. 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...

  16. 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)

  17. The tables of the discipline

    Directory of Open Access Journals (Sweden)

    Doroshin B. A.

    2013-03-01

    Full Text Available This publication presents the training table, which presents the material on the theory of the origin of the state, causes and effects in the formation of the state in terms of socio-economic determinism, political, economic, social, environmental, law enforcement, national, cultural and external functions of the state. The tables can be used by teachers as a component of training materials provided to students for independent work, and to create presentations, students demonstrated in classroom learning.

  18. The Periodic Table in Croatia

    OpenAIRE

    Raos, N.

    2011-01-01

    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 enthusiasti...

  19. 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...

  20. Typologie des consommateurs en fonction de la proximité perçue en vente directe : exploration de trois formes de vente : AMAP, Points de vente collectifs et Marchés

    OpenAIRE

    Hérault-Fournier, Catherine; Prigent-Simonin, Anne-Hélène

    2012-01-01

    Cet article présente une analyse des scores de proximité perçue par des consommateurs dans trois modalités de vente directe : AMAP, Points de vente collectifs et marchés. Prenant appui sur échantillon de 579 individus ces travaux montrent 1- que les scores de proximité perçue par les consommateurs sont significativement différents d’une modalité de vente à une autre, 2- qu’il est possible de déterminer trois types de consommateurs en fonction des scores de proximité perçue : les intimes, les...

  1. 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

  2. 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

  3. STIL - Starlink Tables Infrastructure Library

    Science.gov (United States)

    Taylor, Mark

    STIL is a set of Java class libraries which allow input, manipulation and output of tabular data and metadata. Among its key features are support for many tabular formats (including VOTable, FITS, CDF, text-based formats and SQL databases) and support for dealing with very large tables in limited memory. As well as an abstract and format-independent definition of what constitutes a table, and an extensible framework for "pull-model" table processing, it provides a number of format-specific handlers which know how to serialize/deserialize tables. The framework for interaction between the core table manipulation facilities and the format-specific handlers is open and pluggable, so that handlers for new formats can easily be added, programmatically or at run-time. The VOTable handling in particular is provided by classes which perform efficient XML parsing and can read and write VOTables in any of the defined formats (TABLEDATA, BINARY or FITS). It supports table-aware SAX- or DOM-mode processing and may be used on its own for VOTable I/O without much reference to the format-independent parts of the library.

  4. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

  6. 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

  7. Discovery of Nascent Vents and Recent Colonization Associated with(Re)activated Hydrothermal Vent Fields by the GALREX 2011 Expedition on the Galápagos Rift

    Science.gov (United States)

    Shank, T. M.; Holden, J. F.; Herrera, S.; Munro, C.; Muric, T.; Lin, J.; Stuart, L.

    2011-12-01

    GALREX 2011 was a NOAA OER telepresence cruise that explored the diverse habitats and geologic settings of the deep Galápagos region. The expedition made12 Little Hercules ROV dives in July 2011.Abundant corals and a strong depth zonation of species (including deepwater coral communities) were found near 500 m depth on Paramount Seamount, likely influenced by past low sea level states, wave-cut terrace processes, and the historical presence of shallow reef structures. At fresh lava flows with associated (flocculent) hydrothermal venting near 88° W, now known as Uka Pacha and Pegasus Vent Fields, rocks were coated with white microbial mat and lacked sessile fauna, with few mobile fauna (e.g., bythograeid crabs, alvinocarid shrimp, polynoid worms, zoarcid fish, and dirivultid copepods). This suggests a recent creation of hydrothermal habitats through volcanic eruptions and/or diking events, which may have taken place over a 15 km span separating the two vent fields. The Rosebud vent field at 86°W was not observed and may have been covered with lava since last visited in 2005. A hydrothermal vent field near 86°W was discovered that is one of the largest vent fields known on the Rift (120m by 40m). Low-temperature vent habitats were colonized by low numbers of tubeworms including Riftia, Oasisia, and a potential Tevnia species (the latter not previously observed on the Galapagos Rift). Patches of tubeworms were observed with individuals less than 2cm in length, and the relatively few large Riftia had tube lengths near 70cm long. Large numbers of small (microbial communities were observed on the underside and vertical surfaces of basalt rock surfaces. There were at least 13 species of vent-endemic fauna. The active colonization was observed on relatively older basalt pillows and lobate lavas ringed by and amidst a large dead bed of Calyptogena clams (most with broken and dissolving shells greater than 25 cm in length, with a few of the same size living amongst the

  8. Modelling and Control of Blowing-Venting Operations in Manned Submarines

    CERN Document Server

    Font, Roberto; Murillo, Jose Alberto; Periago, Francisco

    2011-01-01

    Motivated by the study of the potential use of blowing and venting operations of ballast tanks in manned submarines as an alternative control system for manoeuvring, we first propose a mathematical model for these operations. This model extends previous works where only blowing is considered. Then, the model is applied to the control of an emergency manoeuvre by using only blowing and venting. To this end, we formulate a suitable constrained, nonlinear, optimal control problem where controls are linked to the variable aperture of blowing and venting valves of each of the tanks. The state law is composed of a system of nonlinear differential equations where the equations modelling blowing and venting processes are coupled with the Feldman, {\\it variable mass}, coefficient based hydrodynamic model for the equations of motion. In a second part, we carry out a rigorous mathematical analysis of the model: existence of a solution for both the state law and the optimal control problem is proved. Finally, we address ...

  9. Arsenic speciation in shrimp and mussel from the Mid-Atlantic hydrothermal vents

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Quetel, C. R.; Munoz, R.; FialaMedioni, A.; Donard, O. F. X.

    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...

  10. 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...

  11. Analysis of containment venting for the Peach Bottom Atomic Power Station

    International Nuclear Information System (INIS)

    The effectiveness of containment venting as a means of preventing or mitigating the consequences of severe accidents was evaluated for Peach Bottom Atomic Power Station Units 2 and 3 (BWR-4s with Mark I containments). Results from this evaluation indicate that the effectiveness of venting in preventing containment failure is highly dependent on the severe accident sequence. Containment venting can be effective for several classes of sequences, including loss-of-coolant accidents with breaks in the containment and transients with a failure of containment heat removal. However, based on draft procedures and equipment in place at the time of the evaluation, containment venting has limited potential for further reducing the risk associated with several sequences currently identified as significant contributors to risk. Means of improving the potential for risk reduction were identified, but their influence on risk was not analyzed

  12. Analysis of containment venting at the Peach Bottom Atomic Power Station

    International Nuclear Information System (INIS)

    An analysis of the extent to which containment venting would be effective in preventing or mitigating the consequences of severe accidents has been completed for the Peach Bottom Atomic Power Station, Units 2 and 3 (BWR-4s with Mark I containments). The analysis indicates that the effectiveness of venting in preventing containment overpressurization highly depends on the sequence of the severe accident. Containment venting can be effective for several classes of sequences, including transients with failure of long-term decay heat removal and loss-of-coolant accidents with breaks inside the containment. However, based on draft procedures and equipment in place at the time of the evaluation, containment venting has limited potential for further reducing the risk associated with three severe accident sequences currently identified as important risk contributors at Peach Bottom. Means of improving the potential for risk reduction is identified, but their influence on risk is not analyzed

  13. Analysis of containment venting at the Peach Bottom atomic power station

    International Nuclear Information System (INIS)

    An analysis of the extent to which containment venting would be effective in preventing or mitigating the consequences of severe accidents has been completed for the Peach Bottom Units 2 and 3 (BWR-4s with Mark I containments). The analysis indicates that the effectiveness of venting in preventing containment overpressurization highly depends on the sequence of the severe accident. Containment venting can be effective for several classes of sequences, including transients with failure of long-term decay heat removal and loss-of-coolant accidents with breaks inside the containment. However, based on draft procedures and equipment in place at the time of the evaluation, containment venting has limited potential for further reducing the risk associated with three severe accident sequences currently identified as important risk contributors at Peach Bottom. Means of improving the potential for risk reduction is identified, but their influence on risk is not analyzed. (orig./HP)

  14. Analysis of containment venting at the Peach Bottom atomic power station

    International Nuclear Information System (INIS)

    An analysis of the extent to which containment venting would be effective in preventing or mitigating the consequences of severe accidents has been completed for the Peach Bottom Atomic Power Station, Units 2 and 3 (BWR-4s with Mark I containments). The analysis indicates that the effectiveness of venting in preventing containment overpressurization highly depends on the sequence of the severe accident. Containment venting can be effective for several classes of sequences, including transients with failure of long-term decay heat removal and loss-of-coolant accidents with breaks inside the containment. However, based on draft procedures and equipment in place at the time of the evaluation, containment venting has limited potential for further reducing the risk associated with three severe accident sequences currently identified as important risk contributors at Peach Bottom. Means of improving the potential for risk reduction is identified, but their influence on risk is not analyzed

  15. 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.

  16. Direct Monte Carlo Simulations of Gas Flow from Enceladus’ Nozzle-like Vents

    Science.gov (United States)

    Tucker, Orenthal; Combi, M. R.; Tenishev, V.

    2013-10-01

    Collective observations by the Cassini spacecraft indicate that the gas plumes emanating from Enceladus’ south pole contain micrometer sized ice grains that travel at speeds 50-80% lower than the bulk gas speed (Kempf et al., 2008, Hedman et al., 2009, Teolis et al., 2010). Previous studies indicate the difference in velocity originates below the surface, and the gas flow to the surface occurs supersonically suggestive of nozzle like vents (Schmidt et al., 2008, Hansen et al., 2011). Here we use a 2D Direct Monte Carlo Simulation (DSMC) technique (Bird, 1994) to model gas flow and grain acceleration in nozzle like fissures for Enceladus’ vent geometries. First, we use the DSMC technique to model the transition of the gas flow from inside the highly collisional vent to a couple of meters above the surface where the gas flow becomes essentially collisionless. Then the DSMC results for gas density, temperature and velocity are used with an equation of motion for the drag force on a grain entrenched in a gas. The flow is tracked in both the vertical direction from the vent opening, and the radial direction from the vent axis. It is impossible to consider every type of vent geometry, but using Cassini data for grain sizes and velocities within the plumes we consider a few vent geometries of different width, length, and opening angle with respect to the surface. The Enceladus vents are not likely to be axially symmetric, but the simulations provide insight into possible vent geometries, and the effect of the vent wall geometry on gas flow and grain acceleration for suggested plume water production rates (0.5 - 1×1028 s-1) inferred using Cassini data (Tenishev et al., 2010). We obtain density and velocity distributions at the vent exit for the gas and grains that can serve as parameters for plume models and be used as comparisons for interpretation of various Cassini measurements. Kempf, S., et al., 2008, Icarus 193, 2. Hedman, M.M., et al., 2009, AJ 693. Teolis, B

  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. Modelling and Control of Blowing-Venting Operations in Manned Submarines

    OpenAIRE

    Font, Roberto; Garcia, Javier; Murillo, Jose Alberto; Periago, Francisco

    2011-01-01

    Motivated by the study of the potential use of blowing and venting operations of ballast tanks in manned submarines as a complementary or alternative control system for manoeuvring, we first propose a mathematical model for these operations. Then we consider the coupling of blowing and venting with the Feldman, variable mass, coefficient based hydrodynamic model for the equations of motion. The final complete model is composed of a system of twenty-four nonlinear ordinary differential equatio...

  19. 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 ...

  20. 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...

  1. 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.

  2. 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.

  3. 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 ...

  4. Cloaca-vent prolapsed in a Lutino fischer’s love bird (Agapornis fischeri

    Directory of Open Access Journals (Sweden)

    Dibyendu Biswas

    2014-02-01

    Full Text Available Cloacal-vent prolapse in a bird is often fatal if left untreated. A 10-month-old female love bird was brought to teaching veterinary hospital, Chittagong Veterinary and Animal Sciences University, Bangladesh, due to an everted cloaca through the vent. This condition was treated successfully by washing, massage, and icing. Calcium was supplemented orally for five days and the bird was cured completely after seven days.

  5. 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...

  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. Hydrothermal vents in Lake Tanganyika harbor spore-forming thermophiles with extremely rapid growth

    DEFF Research Database (Denmark)

    Elsgaard, Lars; Prieur, Daniel

    2010-01-01

    A thermophilic anaerobic bacterium was isolated from a sublacustrine hydrothermal vent site in Lake Tanganyika (East Africa) with recorded fluid temperatures of 66–103 °C and pH values of 7.7–8.9. The bacterium (strain TR10) was rod-shaped, about 1 by 5 μm in size, and readily formed distal...... organism to exploit the temporarily fluctuating growth conditions in the hydrothermal vent environments of Lake Tanganyika...

  9. 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.

  10. Cladorhizid sponges from hydrothermal vents and cold seeps in the NE Atlantic Ocean

    OpenAIRE

    Thomassen, Jon Hestetun

    2009-01-01

    Sponges are known to frequently contain a great number of symbiotic organisms. Symbiosis is also a characteristic trait of vent and seep animals worldwide. Sponges in the deep sea family Cladorhizidae, otherwise also known for their surprising ability to capture invertebrate prey, are among the most common sponges found in proximity to vents, and in one reported case methanotrophic symbiotic bacteria have been described in a cladorhizid species at a mud volcano. The phylogenetic relationships...

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

    OpenAIRE

    SayakaMino; HirokoMaikita; TomohiroToki; ShingoKato; HiromiWatanabe; ShigeakiKojima

    2013-01-01

    Deep-sea hydrothermal vent fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea vents. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal ecosystem around the world, little is known about their population structure ...

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

    OpenAIRE

    Mino, Sayaka; Makita, Hiroko; Toki, Tomohiro; Miyazaki, Junichi; Kato, Shingo; Watanabe, Hiromi; Imachi, Hiroyuki; Watsuji, Tomo-o; Nunoura, Takuro; Kojima, Shigeaki; Sawabe, Tomoo; Takai, Ken; Nakagawa, Satoshi

    2013-01-01

    Deep-sea hydrothermal vent fields are areas on the seafloor with high biological productivity fueled by microbial chemosynthesis. Members of the Aquificales genus Persephonella are obligately chemosynthetic bacteria, and appear to be key players in carbon, sulfur, and nitrogen cycles in high temperature habitats at deep-sea vents. Although this group of bacteria has cosmopolitan distribution in deep-sea hydrothermal ecosystem around the world, little is known about their population structure ...

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Validation testing of radioactive waste drum filter vents

    International Nuclear Information System (INIS)

    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

  18. 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.

  19. 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.

  20. 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

  1. 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.

  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. 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.

  4. 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

  5. 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

  6. Seabed morphology and gas venting features in the continental slope region of KrishnaeGodavari basin, Bay of Bengal: Implications in gas–hydrate exploration

    Digital Repository Service at National Institute of Oceanography (India)

    Dewangan, P.; Ramprasad, T.; Ramana, M.V.; Mazumdar, A.; Desa, M.; Badesab, F.K.

    prominent positive topographic features in the bathymetry data. These mounds show fluid/gas migration features such as acoustic voids, acoustic chimneys, and acoustic turbid layers. It is interesting to note that drilling/coring onboard JOIDES...

  7. Ken Thompson's 6-man Tables

    OpenAIRE

    Tamplin, John T; Haworth, Guy McCrossan

    2001-01-01

    Ken Thompson recently communicated some results mined from his set of 64 6-man endgame tables. These list some positions of interest, namely, mutual zugzwangs and those of maximum depth. The results have been analysed by the authors and found to be identical or compatible with the available or published findings of Karrer, Nalimov, Stiller and Wirth.

  8. Superconductivity and the periodic table

    International Nuclear Information System (INIS)

    Compiled data on superconducting transition temperature Tc for pure metals (including amorphous and high-pressure phases) from the first, second, and third long periods of the Periodic Table and for their analogous compounds show that a significant regularity exists in the relative values of Tc

  9. 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

  10. Sand and Water Table Play

    Science.gov (United States)

    Wallace, Ann H.; White, Mary J.; Stone, Ryan

    2010-01-01

    The authors observed preschoolers engaged at the sand and water table to determine if math could be found within their play. Wanting to understand how children interact with provided materials and what kinds of math ideas they explore during these interactions, the authors offer practical examples of how such play can promote mathematical…

  11. Liquid Oxygen Thermodynamic Vent System Testing with Helium Pressurization

    Science.gov (United States)

    VanDresar, Neil T.

    2014-01-01

    This report presents the results of several thermodynamic vent system (TVS) tests with liquid oxygen plus a test with liquid nitrogen. In all tests, the liquid was heated above its normal boiling point to 111 K for oxygen and 100 K for nitrogen. The elevated temperature was representative of tank conditions for a candidate lunar lander ascent stage. An initial test series was conducted with saturated oxygen liquid and vapor at 0.6 MPa. The initial series was followed by tests where the test tank was pressurized with gaseous helium to 1.4 to 1.6 MPa. For these tests, the helium mole fraction in the ullage was quite high, about 0.57 to 0.62. TVS behavior is different when helium is present than when helium is absent. The tank pressure becomes the sum of the vapor pressure and the partial pressure of helium. Therefore, tank pressure depends not only on temperature, as is the case for a pure liquid-vapor system, but also on helium density (i.e., the mass of helium divided by the ullage volume). Thus, properly controlling TVS operation is more challenging with helium pressurization than without helium pressurization. When helium was present, the liquid temperature would rise with each successive TVS cycle if tank pressure was kept within a constant control band. Alternatively, if the liquid temperature was maintained within a constant TVS control band, the tank pressure would drop with each TVS cycle. The final test series, which was conducted with liquid nitrogen pressurized with helium, demonstrated simultaneous pressure and temperature control during TVS operation. The simultaneous control was achieved by systematic injection of additional helium during each TVS cycle. Adding helium maintained the helium partial pressure as the liquid volume decreased because of TVS operation. The TVS demonstrations with liquid oxygen pressurized with helium were conducted with three different fluid-mixer configurations-a submerged axial jet mixer, a pair of spray hoops in the tank

  12. Non-Venting Thermal and Humidity Control for EVA Suits

    Science.gov (United States)

    Izenson, Mike; Chen, Weibo; Bue, Grant

    2011-01-01

    Future EVA suits need processes and systems to control internal temperature and humidity without venting water to the environment. This paper describes an absorption-based cooling and dehumidification system as well as laboratory demonstrations of the key processes. There are two main components in the system: an evaporation cooling and dehumidification garment (ECDG) that removes both sensible heat and latent heat from the pressure garment, and an absorber radiator that absorbs moisture and rejects heat to space by thermal radiation. This paper discusses the overall design of both components, and presents recent data demonstrating their operation. We developed a design and fabrication approach to produce prototypical heat/water absorbing elements for the ECDG, and demonstrated by test that these elements could absorb heat and moisture at a high flux. Proof-of-concept tests showed that an ECDG prototype absorbs heat and moisture at a rate of 85 W/ft under conditions that simulate operation in an EVA suit. The heat absorption was primarily due to direct absorption of water vapor. It is possible to construct large, flexible, durable cooling patches that can be incorporated into a cooling garment with this system. The proof-of-concept test data was scaled to calculate area needed for full metabolic loads, thus showing that it is feasible to use this technology in an EVA suit. Full-scale, lightweight absorber/radiator modules have also been built and tested. They can reject heat at a flux of 33 W/ft while maintaining ECDG operation at conditions that will provide a cool and dry environment inside the EVA suit.

  13. Highly isotopically depleted isoprenoids: Molecular markers for ancient methane venting

    Science.gov (United States)

    Thiel, Volker; Peckmann, Jörn; Seifert, Richard; Wehrung, Patrick; Reitner, Joachim; Michaelis, Walter

    1999-12-01

    We propose that organic compounds found in a Miocene limestone from Marmorito (Northern Italy) are source markers for organic matter present in ancient methane vent systems (cold seeps). The limestone contains high concentrations of the tail-to-tail linked, acyclic C 20 isoprenoid 2,6,11,15-tetramethylhexadecane (crocetane), a C 25 homolog 2,6,10,15,19-pentamethylicosane (PME), and a distinctive glycerol ether lipid containing 3,7,11,15-tetramethylhexadecyl (phytanyl-) moieties. The chemical structures of these biomarkers indicate a common origin from archaea. Their extremely 13C-depleted isotope compositions (δ 13C ≈ -108 to -115.6‰ PDB) suggest that the respective archaea have directly or indirectly introduced isotopically depleted, methane-derived carbon into their biomass. We postulate that a second major cluster of biomarkers showing heavier isotope values (δ 13C ≈ -88‰) is derived from sulfate-reducing bacteria (SRB). The observed biomarkers sustain the idea that methanogenic bacteria, in a syntrophic community with SRB, are responsible for the anaerobic oxidation of methane in marine sediments. Marmorito may thus represent a conceivable ancient scenario for methane consumption performed by a defined, two-membered bacterial consortium: (1) archaea that perform reversed methanogenesis by oxidizing methane and producing CO 2 and H 2; and (2) SRB that consume the resulting H 2. Furthermore, the respective organic molecules are, unlike other compounds, tightly bound to the crystalline carbonate phase. The Marmorito carbonates can thus be regarded as "cold seep microbialites" rather than mere "authigenic" carbonates.

  14. Hydrogen risk in the Containment Filtered Venting System

    International Nuclear Information System (INIS)

    It was observed that the thermal hydraulic conditions in the CFVS (Containment Filtered Venting System) vessel sharply changed markedly, especially the steam condensation in the early CFVS operation can affect the hydrogen behavior such as the combustion. This paper summarizes the calculated results on hydrogen concentration in the CFVS vessel, which was presented at The Ninth Korea-Japan Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS9) last year. The MELCOR computer code calculated the thermal-hydraulic conditions in the containment building of OPR 1000, and in the cylindrical CFVS vessel with 3 m in diameter and 6.5 m in height under an SBO. After the operation of the CFVS, the pressure and temperature in the containment building decreased, and those in the CFVS vessel jumped from the initial conditions of atmosphere pressure and room temperature. These big differences of thermal-hydraulic conditions can make the volumetric concentrations of steam and gas mixtures in the CFVS vessel to be changed in comparison with those in the containment building. The volumetric concentration of hydrogen increased from 6% in the containment to 14% in the CFVS vessel after the operation of the CFVS, while the concentration of steam decreased from 58% in the containment to 3% in the CFVS vessel. The increased volumetric concentration of hydrogen (14%) with the other concentrations of steam (3%) and air (60%) in the CFVS vessel exists within the region of the burn limit in the Shapiro diagram. This possibility of the hydrogen combustion can threaten the integrity of the CFVS

  15. Evaluation of Passive Vents in New Construction Multifamily Buildings

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, Sean [Steven Winter Associates, Inc., Norwalk, CT (United States); Berger, David [Steven Winter Associates, Inc., Norwalk, CT (United States); Zuluaga, Marc [Steven Winter Associates, Inc., Norwalk, CT (United States)

    2016-02-01

    Exhaust ventilation and corresponding outdoor air strategies are being implemented in high-performance new construction multifamily buildings to meet program or code requirements for improved indoor air quality, but a lack of clear design guidance is resulting in poor performance of these systems despite the best intentions of the programs or standards. CARB's 2014 'Evaluation of Ventilation Strategies in New Construction Multifamily Buildings' consistently demonstrated that commonly used outdoor air strategies are not performing as expected. Of the four strategies evaluated in 2014, the exhaust ventilation system that relied on outdoor air from a pressurized corridor was ruled out as a potential best practice due to its conflict with meeting requirements within most fire codes. Outdoor air that is ducted directly to the apartments was a strategy determined to have the highest likelihood of success, but with higher first costs and operating costs. Outdoor air through space conditioning systems was also determined to have good performance potential, with proper design and execution. The fourth strategy, passive systems, was identified as the least expensive option for providing outdoor air directly to apartments, with respect to both first costs and operating costs. However, little is known about how they actually perform in real-world conditions or how to implement them effectively. Based on the lack of data available on the performance of these low-cost systems and their frequent use in the high-performance building programs that require a provision for outdoor air, this research project sought to further evaluate the performance of passive vents.

  16. Causes and consequences of backdrafting of vented gas appliances.

    Science.gov (United States)

    Nagda, N L; Koontz, M D; Billick, I H; Leslie, N P; Behrens, D W

    1996-09-01

    House depressurization occurs when household equipment such as a kitchen or bathroom fan or a fireplace exhausts air from the house and lowers the pressure indoors with respect to the outside. The operation of air handlers for forced-air heating or cooling systems also can have a depressurization effect. This depressurization can hinder the natural draft from vented combustion appliances and lead to backdrafting, which in turn can result in combustion gases spilling into the indoor airspace. Extensive spillage can cause elevated indoor levels of combustion products such as carbon dioxide (CO2) and water vapor, as well as contaminants such as carbon monoxide (CO) and nitrogen dioxide (NO2). The focus of this paper is to review studies on depressurization-induced backdrafting and spillage from gas-fired, drafthood equipped furnaces and domestic hot water heaters. Qualitative and quantitative techniques that were used in depressurization and backdrafting studies conducted in Canada, Europe, and the United States are analyzed. These studies have shown that exhaust fans operated simultaneously with fireplaces depressurize houses by 3 to 8 Pa on average. The CO indoor concentrations due to spillage, as reported in these studies, generally have been lower than 5 ppm. However, such low CO concentrations do not necessarily imply that a potential problem associated with backdrafting does not exist. Other combustion products, such as NO2, rarely have been measured in prior backdrafting studies. It can be concluded from the literature review that causes of house depressurization are well understood. However, more comprehensive research is needed to better understand the frequency, duration, and severity of depressurization-induced spillage in a broad cross section of houses. Efforts in this direction have begun recently in the United States through a workshop to define research issues, pilot studies to develop comprehensive measurement protocols, and consensus standard

  17. Vibrio diabolicus challenge in Bathymodiolus azoricus populations from Menez Gwen and Lucky Strike hydrothermal vent sites.

    Science.gov (United States)

    Martins, Eva; Santos, Ricardo Serrão; Bettencourt, Raul

    2015-12-01

    Menez Gwen (MG) and Lucky Strike (LS) deep-sea hydrothermal vents are located at 850 m and 1730 m depths respectively and support chemosynthesis-based ecosystems partially differing in heavy metal concentration, temperature range, and faunistic composition. The successfully adapted deep-sea vent mussel Bathymodiolus azoricus is found at both vent locations. In such inhospitable environments survival strategies rely on the establishment of bacteria-vent animal symbiosis In spite of the toxic nature of deep-sea vents, the problem of microbial threat and the need for immunity exist in B. azoricus. This study aims at investigating the immune system of B. azoricus from MG and LS populations by comparing immune gene expressions profiles using the deep-sea vent-related Vibrio diabolicus. Expression of nineteen immune genes was analyzed from gill, digestive gland and mantle tissues upon 3 h, 12 h and 24 h V. diabolicus challenges. Based on quantitative-Polymerase Chain Reaction (qPCR) significant gene expression differences were found among MG and LS populations and challenge times MG mussels revealed that gill and digestive gland gene expression levels were remarkably higher than those from LS mussels. Expression of Carcinolectin, Serpin-2, SRCR, IRGs, RTK, TLR2, NF-κB, HSP70 and Ferritin genes was greater in MG than LS mussels. In contrast, mantle tissue from LS mussels revealed the highest peak of expression at 24 h for most genes analyzed. The activation of immune signaling pathways demonstrated that gene expression profiles are distinct between the two mussel populations. These differences may possibly ensue from intrinsic immune transcriptional activities upon which host responses are modulated in presence of V. diabolicus. mRNA transcript variations were assessed during 24 h acclimatization taking into account the partial depuration to which mussels were subjected to. Additionally, gene expression differences may reflect still accountable effects from the presence

  18. 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)

  19. Global Reference Tables for Management Information Systems.

    Data.gov (United States)

    Social Security Administration — This database is a collection of reference tables that store common information used throughout SSA. These tables standardize code structures and code usage of SSA...

  20. NNDSS - Table II. Lyme disease to Meningococcal

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Lyme disease to Meningococcal - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the...