Science.gov

Sample records for aggregate batch vent

  1. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  2. 40 CFR 63.1408 - Aggregate batch vent stream provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Aggregate batch vent stream provisions... § 63.1408 Aggregate batch vent stream provisions. (a) Emission standards. Owners or operators of aggregate batch vent streams at a new or existing affected source shall comply with either paragraph...

  3. 40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during carbon bed regeneration cycle measured during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  4. 40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during carbon bed regeneration cycle measured during the... firebox temperature measured during the performance test—NCS. c 3. Record the batch cycle daily...

  5. 40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during carbon bed regeneration cycle measured during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  6. 40 CFR Table 7 to Subpart Jjj of... - Group 1 Batch Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping, and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during carbon bed regeneration cycle measured during the... firebox temperature measured during the performance test—NCS. c 3. Record the batch cycle daily...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle.2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during carbon bed regeneration cycle measured during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  8. 40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during each carbon bed regeneration cycle during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  9. 40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during each carbon bed regeneration cycle during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  10. 40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during each carbon bed regeneration cycle during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  11. 40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... nitrogen flow, or pressure for each carbon bed regeneration cycle. 2. Record and report the total regeneration steam flow or nitrogen flow, or pressure during each carbon bed regeneration cycle during the... measured during the performance test—NCS. c 3. Record the batch cycle daily average firebox temperature...

  12. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false 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...

  13. 40 CFR 63.1406 - Reactor batch process vent provisions.

    Code of Federal Regulations, 2010 CFR

    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...

  14. 40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., readily accessible: (1) The annual mass emissions of halogen atoms in the batch process vent or aggregate... scrubber or other halogen reduction device following a combustion device to control halogenated batch... and halogens as determined under § 63.1325(d)(3) or the emission limit determined under §...

  15. 40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... records, as applicable, readily accessible: (1) The annual mass emissions of halogen atoms in the batch... aggregate batch vent streams; and (iv) For a scrubber or other halogen reduction device following a... streams, the percent reduction of total hydrogen halides and halogens, as determined under §...

  16. 40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... records, as applicable, readily accessible: (1) The annual mass emissions of halogen atoms in the batch... aggregate batch vent streams; and (iv) For a scrubber or other halogen reduction device following a... streams, the percent reduction of total hydrogen halides and halogens, as determined under §...

  17. 40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., readily accessible: (1) The annual mass emissions of halogen atoms in the batch process vent or aggregate... scrubber or other halogen reduction device following a combustion device to control halogenated batch... and halogens as determined under § 63.1325(d)(3) or the emission limit determined under §...

  18. 40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., readily accessible: (1) The annual mass emissions of halogen atoms in the batch process vent or aggregate... scrubber or other halogen reduction device following a combustion device to control halogenated batch... and halogens as determined under § 63.1325(d)(3) or the emission limit determined under §...

  19. 40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., readily accessible: (1) The annual mass emissions of halogen atoms in the batch process vent or aggregate... scrubber or other halogen reduction device following a combustion device to control halogenated batch... and halogens as determined under § 63.1325(d)(3) or the emission limit determined under §...

  20. 40 CFR 63.1326 - Batch process vents-recordkeeping provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., readily accessible: (1) The annual mass emissions of halogen atoms in the batch process vent or aggregate... scrubber or other halogen reduction device following a combustion device to control halogenated batch... and halogens as determined under § 63.1325(d)(3) or the emission limit determined under §...

  1. 40 CFR 63.1407 - Non-reactor batch process vent provisions.

    Code of Federal Regulations, 2010 CFR

    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...

  2. 40 CFR 63.1407 - Non-reactor batch process vent provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false 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...

  3. 40 CFR 63.492 - Batch front-end process vents-reporting requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... causes a Group 2 batch front-end process vent to become a Group 1 batch front-end process vent, the owner..., as defined in § 63.488(i)(1), is made that causes a Group 2 batch front-end process vent with annual... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Batch front-end process...

  4. 40 CFR 63.1322 - Batch process vents-reference control technology.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  5. 40 CFR 63.1322 - Batch process vents-reference control technology.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Batch process vents-reference control technology. 63.1322 Section 63.1322 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Batch process vents—reference control technology. (a) Batch process vents. The owner or operator of...

  6. 40 CFR 63.486 - Batch front-end process vent provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... technology requirements for Group 1 batch front-end process vents in § 63.487, the monitoring requirements in... Group 2 batch front-end process vents shall comply with the applicable reference control technology... National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins §...

  7. 40 CFR 63.1324 - Batch process vents-monitoring equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Batch process vents-monitoring... Batch process vents—monitoring equipment. (a) General requirements. Each owner or operator of a batch... § 63.1322(a) or § 63.1322(b), shall install the monitoring equipment specified in paragraph (c) of...

  8. 40 CFR 63.487 - Batch front-end process vents-reference control technology.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Batch front-end process vents-reference control technology. 63.487 Section 63.487 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 63.487 Batch front-end process vents—reference control technology. (a) Batch front-end process...

  9. 12. Interior view of cement and aggregate batch plant showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. Interior view of cement and aggregate batch plant showing storage bins. Photographer unknown, c. 1926. Source: Ralph Pleasant. - Waddell Dam, On Agua Fria River, 35 miles northwest of Phoenix, Phoenix, Maricopa County, AZ

  10. 40 CFR 63.489 - Batch front-end process vents-monitoring equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Batch front-end process vents-monitoring equipment. 63.489 Section 63.489 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... installed in the gas stream immediately before and after the catalyst bed. (2) Where a flare is used,...

  11. 40 CFR Table 2 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Batch Process Vents

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 14 2010-07-01 2010-07-01 false Emission Limits and Compliance Requirements for Batch Process Vents 2 Table 2 to Subpart VVVVVV of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR...

  12. 40 CFR Table 2 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Batch Process Vents

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 15 2012-07-01 2012-07-01 false Emission Limits and Compliance Requirements for Batch Process Vents 2 Table 2 to Subpart VVVVVV of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR...

  13. 40 CFR Table 2 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Batch Process Vents

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 15 2013-07-01 2013-07-01 false Emission Limits and Compliance Requirements for Batch Process Vents 2 Table 2 to Subpart VVVVVV of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR...

  14. 40 CFR Table 2 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Batch Process Vents

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 14 2011-07-01 2011-07-01 false Emission Limits and Compliance Requirements for Batch Process Vents 2 Table 2 to Subpart VVVVVV of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR...

  15. 40 CFR 63.487 - Batch front-end process vents-reference control technology.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins...) of this section. Compliance may be based on either organic HAP or TOC. (1) For each batch front-end process vent, reduce organic HAP emissions using a flare. (i) The owner or operator of the...

  16. 40 CFR 63.487 - Batch front-end process vents-reference control technology.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. (2) A halogen reduction device may be used to reduce the halogen atom mass emission rate to less than 3,750 kg/yr for batch front-end process vents...

  17. 40 CFR 63.487 - Batch front-end process vents-reference control technology.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. (2) A halogen reduction device may be used to reduce the halogen atom mass emission rate to less than 3,750 kg/yr for batch front-end process vents...

  18. 40 CFR 63.487 - Batch front-end process vents-reference control technology.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. (2) A halogen reduction device may be used to reduce the halogen atom mass emission rate to less than 3,750 kg/yr for batch front-end process vents...

  19. 40 CFR 63.488 - Methods and procedures for batch front-end process vent group determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Polymers and Resins § 63.488 Methods and procedures for batch front-end process vent group determination... be based on either organic HAP or TOC emissions. (1) The procedures specified in paragraphs (b... of product. (2) The annual uncontrolled organic HAP or TOC emissions and annual average batch...

  20. 40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 13 2014-07-01 2014-07-01 false Emission Limits and Work Practice... of Part 63—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...

  1. 40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 12 2011-07-01 2009-07-01 true Emission Limits and Work Practice...—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...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 13 2013-07-01 2012-07-01 true Emission Limits and Work Practice... of Part 63—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...

  3. 40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 12 2010-07-01 2010-07-01 true Emission Limits and Work Practice...—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...

  4. 40 CFR Table 5 to Subpart Ppp of... - Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 5 Table 5 to Subpart PPP of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

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

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 5 Table 5 to Subpart PPP of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

  6. 40 CFR Table 5 to Subpart Ppp of... - Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 5 Table 5 to Subpart PPP of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

  7. 40 CFR Table 5 to Subpart Ppp of... - Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements 5 Table 5 to Subpart PPP of Part 63 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS...

  8. 40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., and the total emissions associated with one batch cycle, as described in either paragraph (a)(2)(i) or... with § 63.487(a)(2), records documenting the batch cycle percent reduction as specified in § 63.490(c... place of continuous records. (ii) For carbon adsorbers, the records specified in Table 6 of this...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... halogenated continuous process vent, said emissions exiting the combustion device shall be ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. (2) A halogen reduction device may be used to reduce the halogen...

  10. 40 CFR 63.1322 - Batch process vents-reference control technology.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... halogenated continuous process vent, said emissions exiting the combustion device shall be ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. (2) A halogen reduction device may be used to reduce the halogen...

  11. 40 CFR 63.1322 - Batch process vents-reference control technology.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... halogenated continuous process vent, said emissions exiting the combustion device shall be ducted to a halogen reduction device that reduces overall emissions of hydrogen halides and halogens by at least 99 percent before discharge to the atmosphere. (2) A halogen reduction device may be used to reduce the halogen...

  12. 40 CFR 63.1324 - Batch process vents-monitoring equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... such as low leg drains, high point bleeds, analyzer vents, open-ended valves or lines, and pressure... recorder shall be located at the scrubber influent for liquid flow. Gas stream flow shall be determined... appropriate adjustments for pressure drop. (B) If the scrubber is subject to regulations in 40 CFR parts...

  13. Improvement of biohydrogen production from solid wastes by intermittent venting and gas flushing of batch reactors headspace.

    PubMed

    Valdez-Vazquez, Idania; Ríos-Leal, Elvira; Carmona-Martínez, Alessandro; Muñoz-Páez, Karla M; Poggi-Varaldo, Héctor M

    2006-05-15

    Headspace of batch minireactors was intermittently vented and gas flushed with N2 in order to enhance H2 production (PH) by anaerobic consortia degrading organic solid wastes. Type of inocula (meso and thermophilic), induction treatment (heat-shock pretreatment, HSP, and acetylene, Ac), and incubation temperature (37 and 55 degrees C) were studied by means of a factorial design. On average, it was found that mesophilic incubation had the most significant positive effect on PH followed by treatment with Ac, although the units with the best performance (high values of PH, initial hydrogen production rate, and short lag time) were those HSP-induced units incubated at 37 degrees C (type of inocula was not significant). In this way, after 720 h of incubation PH was inhibited in those units by H2 partial pressure (pH2) of 0.54 atm. Venting and gas flushing with N2 was efficient to eliminate that inhibition achieving additional hydrogen generation in subsequent incubation cycles although smaller than the first one. Thus, four cycles of PH were obtained from the same substrate with neither addition of inocula nor application of induction treatment obtaining an increment of 100% in the generated H2. In those subsequent cycles there was a positive correlation between PH and organic acids/solvent ratio; maximum values were found in the first cycle. Solventogenesis could be clearly distinguished in third and fourth production cycles, probably due to a metabolic shift originated by high organic acid concentrations.

  14. 40 CFR 63.491 - Batch front-end process vents-recordkeeping requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins... organic HAP emissions, determined at the exit from the batch unit operation before any emission control... (b)(2): (i) For an incinerator or non-combustion control device, the percent reduction of organic...

  15. 40 CFR 63.489 - Batch front-end process vents-monitoring equipment.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-monitoring equipment. 63.489 Section 63.489 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... § 63.489 Batch front-end process vents—monitoring equipment. (a) General requirements. Each owner or... comply with the requirements in § 63.487(a)(2) or § 63.487(b)(2) shall install the monitoring...

  16. Hydrothermal vent meiobenthos associated with mytilid mussel aggregations from the Mid-Atlantic Ridge and the East Pacific Rise

    NASA Astrophysics Data System (ADS)

    Zekely, J.; Van Dover, C. L.; Nemeschkal, H. L.; Bright, M.

    2006-08-01

    Deep-sea hydrothermal vents occur along the mid-ocean ridges and back-arc basins around the globe. There are very few community analyses of vent meiobenthos. The central objectives of this study were to identify and quantify for the first time the entire metazoan meiobenthic community associated with mussel aggregations of Bathymodiolus thermophilus Kenk and Wilson, 1985 from the EPR, 11°N and of Bathymodiolus puteoserpentis Cosel et al., 1994 from the Mid-Atlantic Ridge (MAR), 23°N. Using a quantitative sampling method, abundance, biomass, sex ratio, species richness, diversity, evenness, and trophic structure were studied based on three samples from each site. Meiobenthic abundance in each sample was unexpectedly low, but similar between sites. The community was composed of nematodes, copepods, ostracods, and mites, with a total of 24 species at EPR vents, and 15 species at MAR vents. While most copepod species were vent endemics within the family Dirivultidae, nematodes and harpacticoid copepods belonged to generalist genera, which occur at a variety of habitats and are not restricted to hydrothermal vents or the deep sea. The meiobenthos of hydrothermal-vent mussel beds constitutes a unique community unlike those of other sulfidic habitats, including the thiobios of shallow-water sediments and the meiobenthos of deep-sea, cold-seep sediments. The trophic structure was dominated by primary consumers, mainly deposit feeders, followed by parasites. Predatory meiofaunal species were absent.

  17. Pseudomonas aeruginosa PAO1 preferentially grows as aggregates in liquid batch cultures and disperses upon starvation.

    PubMed

    Schleheck, David; Barraud, Nicolas; Klebensberger, Janosch; Webb, Jeremy S; McDougald, Diane; Rice, Scott A; Kjelleberg, Staffan

    2009-01-01

    In both natural and artificial environments, bacteria predominantly grow in biofilms, and bacteria often disperse from biofilms as freely suspended single-cells. In the present study, the formation and dispersal of planktonic cellular aggregates, or 'suspended biofilms', by Pseudomonas aeruginosa in liquid batch cultures were closely examined, and compared to biofilm formation on a matrix of polyester (PE) fibers as solid surface in batch cultures. Plankton samples were analyzed by laser-diffraction particle-size scanning (LDA) and microscopy of aggregates. Interestingly, LDA indicated that up to 90% of the total planktonic biomass consisted of cellular aggregates in the size range of 10-400 microm in diameter during the growth phase, as opposed to individual cells. In cultures with PE surfaces, P. aeruginosa preferred to grow in biofilms, as opposed to planktonicly. However, upon carbon, nitrogen or oxygen limitation, the planktonic aggregates and PE-attached biofilms dispersed into single cells, resulting in an increase in optical density (OD) independent of cellular growth. During growth, planktonic aggregates and PE-attached biofilms contained densely packed viable cells and extracellular DNA (eDNA), and starvation resulted in a loss of viable cells, and an increase in dead cells and eDNA. Furthermore, a release of metabolites and infective bacteriophage into the culture supernatant, and a marked decrease in intracellular concentration of the second messenger cyclic di-GMP, was observed in dispersing cultures. Thus, what traditionally has been described as planktonic, individual cell cultures of P. aeruginosa, are in fact suspended biofilms, and such aggregates have behaviors and responses (e.g. dispersal) similar to surface associated biofilms. In addition, we suggest that this planktonic biofilm model system can provide the basis for a detailed analysis of the synchronized biofilm life cycle of P. aeruginosa.

  18. 40 CFR Table 6 to Subpart U of... - Group 1 Batch Front-End Process Vents and Aggregate Batch Vent Streams-Monitoring, Recordkeeping...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins Pt. 63, Subpt. U, Table 6 Table... alternative to the above) Concentration level or reading indicated by an organic monitoring device at the... collected as specified in § 63.506(e)(6)(iii)(C). f Alternatively, these devices may comply with the...

  19. Technical note: In vitro total gas and methane production measurements from closed or vented rumen batch culture systems.

    PubMed

    Cattani, M; Tagliapietra, F; Maccarana, L; Hansen, H H; Bailoni, L; Schiavon, S

    2014-03-01

    This study compared measured gas production (GP) and computed CH4 production values provided by closed or vented bottles connected to gas collection bags. Two forages and 3 concentrates were incubated. Two incubations were conducted, where the 5 feeds were tested in 3 replicates in closed or vented bottles, plus 4 blanks, for a total of 64 bottles. Half of the bottles were not vented, and the others were vented at a fixed pressure (6.8 kPa) and gas was collected into one gas collection bag connected to each bottle. Each bottle (317 mL) was filled with 0.4000 ± 0.0010 g of feed sample and 60 mL of buffered rumen fluid (headspace volume = 257 mL) and incubated at 39.0°C for 24 h. At 24 h, gas samples were collected from the headspace of closed bottles or from headspace and bags of vented bottles and analyzed for CH4 concentration. Volumes of GP at 24 h were corrected for the gas dissolved in the fermentation fluid, according to Henry's law of gas solubility. Methane concentration (mL/100mL of GP) was measured and CH4 production (mL/g of incubated DM) was computed using corrected or uncorrected GP values. Data were analyzed for the effect of venting technique (T), feed (F), interaction between venting technique and feed (T × F), and incubation run as a random factor. Closed bottles provided lower uncorrected GP (-18%) compared with vented bottles, especially for concentrates. Correction for dissolved gas reduced but did not remove differences between techniques, and closed bottles (+25 mL of gas/g of incubated DM) had a greater magnitude of variation than did vented bottles (+1 mL of gas/g of incubated DM). Feeds differed in uncorrected and corrected GP, but the ranking was the same for the 2 techniques. The T × F interaction influenced uncorrected GP values, but this effect disappeared after correction. Closed bottles provided uncorrected CH4 concentrations 23% greater than that of vented bottles. Correction reduced but did not remove this difference. Methane

  20. 40 CFR 63.490 - Batch front-end process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Pollutant Emissions: Group I Polymers and Resins § 63.490 Batch front-end process vents—performance test... may be based on either total organic HAP or TOC. For purposes of this paragraph (c), the term “batch... inlet sampling sites shall ensure the measurement of total organic HAP or TOC (minus methane and...

  1. Evaluating the inter and intra batch variability of protein aggregation behaviour using Taylor dispersion analysis and dynamic light scattering.

    PubMed

    Hulse, Wendy L; Gray, Jason; Forbes, Robert T

    2013-09-10

    Biosimilar pharmaceuticals are complex biological molecules that have similar physicochemical properties to the originator therapeutic protein. They are produced by complex multi-stage processes and are not truly equivalent. Therefore, for a biosimilar to be approved for market it is important to demonstrate that the biological product is highly similar to a reference product. This includes its primary and higher order structures and its aggregation behaviour. Representative lots of both the proposed biosimilar and the reference product are analysed to understand the lot-to-lot variability of both drug substances in the manufacturing processes. Whilst it is not easy to characterise every variation of a protein structure at present additional analytical technologies need to be utilised to ensure the safety and efficacy of any potential biosimilar product. We have explored the use of Taylor dispersion analysis (TDA) to analyse such batch to batch variations in the model protein, bovine serum albumin (BSA) and compared the results to that obtained by conventional dynamic light scattering analysis (DLS). Inter and intra batch differences were evident in all grades of BSA analysed. However, the reproducibility of the TDA measurements, enabled the stability and reversibility of BSA aggregates to be more readily monitored. This demonstrates that Taylor dispersion analysis is a very sensitive technique to study higher order protein states and aggregation. The results, here, also indicate a correlation between protein purity and the physical behaviour of the samples after heat shocking. Here, the protein with the highest quoted purity resulted in a reduced increase in the measured hydrodynamic radius after heat stressing, indicating that less unfolding/aggregation had occurred. Whilst DLS was also able to observe the presence of aggregates, its bias towards larger aggregates indicated a much larger increase in hydrodynamic radii and is less sensitive to small changes in

  2. 40 CFR 63.1325 - Batch process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... recovery device to comply with the percent reduction requirement in § 63.1322(a)(3) shall conduct... test, with or without adjustments, reliably demonstrate compliance despite process changes. Recovery... control device. An owner or operator shall determine the percent reduction for the batch cycle using...

  3. Prolonged ascent and episodic venting of discrete magma batches at the onset of the Huckleberry Ridge supereruption, Yellowstone

    NASA Astrophysics Data System (ADS)

    Myers, Madison L.; Wallace, Paul J.; Wilson, Colin J. N.; Morter, Beth K.; Swallow, Elliot J.

    2016-10-01

    geochemically distinct magma domains. The compositions of REs and obsidian pyroclasts, by comparison, show that by the onset of eruption, the quartz had been brought together into three discrete magma bodies, which we interpret to have been cupolas on the roof of the main magma body. These cupolas were erupted sequentially and episodically from separate vents to generate the fall deposits before escalating activity led to generation of voluminous pyroclastic flows, and this pattern of activity suggests that tectonic triggering may have destabilized multiple magma bodies. Supereruptions as large as the Huckleberry Ridge event may start hesitatingly if the parental magma bodies are not strongly overpressured, with small-scale episodic activity that is modulated by external controls that may leave no other geological evidence for their presence.

  4. Free-living bacterial communities associated with tubeworm (Ridgeia piscesae) aggregations in contrasting diffuse flow hydrothermal vent habitats at the Main Endeavour Field, Juan de Fuca Ridge.

    PubMed

    Forget, Nathalie L; Kim Juniper, S

    2013-04-01

    We systematically studied free-living bacterial diversity within aggregations of the vestimentiferan tubeworm Ridgeia piscesae sampled from two contrasting flow regimes (High Flow and Low Flow) in the Endeavour Hydrothermal Vents Marine Protected Area (MPA) on the Juan de Fuca Ridge (Northeast Pacific). Eight samples of particulate detritus were recovered from paired tubeworm grabs from four vent sites. Most sequences (454 tag and Sanger methods) were affiliated to the Epsilonproteobacteria, and the sulfur-oxidizing genus Sulfurovum was dominant in all samples. Gammaproteobacteria were also detected, mainly in Low Flow sequence libraries, and were affiliated with known methanotrophs and decomposers. The cooccurrence of sulfur reducers from the Deltaproteobacteria and the Epsilonproteobacteria suggests internal sulfur cycling within these habitats. Other phyla detected included Bacteroidetes, Actinobacteria, Chloroflexi, Firmicutes, Planctomycetes, Verrucomicrobia, and Deinococcus-Thermus. Statistically significant relationships between sequence library composition and habitat type suggest a predictable pattern for High Flow and Low Flow environments. Most sequences significantly more represented in High Flow libraries were related to sulfur and hydrogen oxidizers, while mainly heterotrophic groups were more represented in Low Flow libraries. Differences in temperature, available energy for metabolism, and stability between High Flow and Low Flow habitats potentially explain their distinct bacterial communities.

  5. Free-living bacterial communities associated with tubeworm (Ridgeia piscesae) aggregations in contrasting diffuse flow hydrothermal vent habitats at the Main Endeavour Field, Juan de Fuca Ridge

    PubMed Central

    Forget, Nathalie L; Kim Juniper, S

    2013-01-01

    We systematically studied free-living bacterial diversity within aggregations of the vestimentiferan tubeworm Ridgeia piscesae sampled from two contrasting flow regimes (High Flow and Low Flow) in the Endeavour Hydrothermal Vents Marine Protected Area (MPA) on the Juan de Fuca Ridge (Northeast Pacific). Eight samples of particulate detritus were recovered from paired tubeworm grabs from four vent sites. Most sequences (454 tag and Sanger methods) were affiliated to the Epsilonproteobacteria, and the sulfur-oxidizing genus Sulfurovum was dominant in all samples. Gammaproteobacteria were also detected, mainly in Low Flow sequence libraries, and were affiliated with known methanotrophs and decomposers. The cooccurrence of sulfur reducers from the Deltaproteobacteria and the Epsilonproteobacteria suggests internal sulfur cycling within these habitats. Other phyla detected included Bacteroidetes, Actinobacteria, Chloroflexi, Firmicutes, Planctomycetes, Verrucomicrobia, and Deinococcus–Thermus. Statistically significant relationships between sequence library composition and habitat type suggest a predictable pattern for High Flow and Low Flow environments. Most sequences significantly more represented in High Flow libraries were related to sulfur and hydrogen oxidizers, while mainly heterotrophic groups were more represented in Low Flow libraries. Differences in temperature, available energy for metabolism, and stability between High Flow and Low Flow habitats potentially explain their distinct bacterial communities. PMID:23401293

  6. Unfolding and aggregation of a glycosylated monoclonal antibody on a cation exchange column. Part I. Chromatographic elution and batch adsorption behavior.

    PubMed

    Guo, Jing; Zhang, Shaojie; Carta, Giorgio

    2014-08-22

    A glycosylated IgG2 monoclonal antibody exhibits a two-peak elution behavior when loaded on a strong cation exchange column and eluted with either a linear salt gradient or two salt steps at increasing salt concentrations. The two-peak behavior is more pronounced for conditions where the initial antibody binding is stronger, i.e. at lower pH and buffer concentration, where the hold time prior to elution is longer, where the protein mass load is lower, and where the load flow rate is higher. The effect is also dependent on the resin type, being prominent for the polymer-functionalized resin Fractogel EMD SO₃(-) and virtually absent for a macroporous resin with similar backbone but no grafted polymers. Size exclusion chromatography and dynamic light scattering show that the early eluting peak consists exclusively of the native monomeric species while the late eluting peak is a mixture of monomeric and aggregated species. Batch adsorption/desorption experiments show that the bound protein can be desorbed in two steps, with a fraction desorbed in 0.33 M NaCl, corresponding to native monomer, and a second fraction desorbed in 1M NaCl. The latter fraction decreases with protein mass load and becomes almost negligible when the resin is initially completely saturated with protein. Confocal laser scanning microscopy showed that the two-peak elution/desorption behavior is related to the unique kinetics of protein binding in the Fractogel resin. Following partial loading of the resin, the bound protein migrates toward the center of the particles during a hold step and is redistributed across the particle volume attaining low local bound protein concentrations. For these conditions the protein is apparently destabilized forming a strongly-bound unfolded intermediate that, in turn, generates aggregates upon elution in high salt.

  7. Vented Capacitor

    DOEpatents

    Brubaker, Michael Allen; Hosking, Terry Alan

    2006-04-11

    A technique of increasing the corona inception voltage (CIV), and thereby increasing the operating voltage, of film/foil capacitors is described. Intentional venting of the capacitor encapsulation improves the corona inception voltage by allowing internal voids to equilibrate with the ambient environment.

  8. Long-Term Aspect of 1980's Submersible-Observed Methane Venting on the Northern Gulf of Mexico Upper Continental Slope: Mapping of Areal Extent and Aggregation: R/V Okeanos Explorer EX1203

    NASA Astrophysics Data System (ADS)

    Carney, R. S.; Roberts, H. H.; Malik, M.

    2012-12-01

    Since the initial discovery of hydrocarbon seeps and associated communities on the upper Louisiana continental slope in 1984 there has been extensive and nearly continuous multidisciplinary exploration of these systems for scientific and regulatory purposes. Four sites within a 45km by 25km rectangle centered at 27° 41' 26.92"N, 91° 28' 4.26"W in the Green Canyon seafloor leasing area were the initial sites confirmed as seep systems by direct observation using the submersible Johnson SeaLink. Hydrocarbon gas venting at these sites ranged from small volume intermittent flow to continuous bubble plumes. The points of emergence ranged from consolidated sediment in mineral-prone environments to fluid muds and brine. The latter two fluid-prone environments represented an active and a quiescent expulsion features. The NOAA Okeanos Explorer Program 2012 expedition 1203 carried out multibeam mapping of this region 6-8 May using both a Konsberg EM 302 288 beam system and a Simrad EK60 scientific echo sounder. Returns from both systems were processed for water column signals. More than 75 indications of bubble plumes were observed representing one of the highest densities as well as magnitudes of individual plumes found to date in the Gulf of Mexico. The plumes were aggregated on the flanks of salt diapirs, ridges between salt-withdrawal basins and areas of multiple slope failures. Correlation with observations begun in the 1980's is good indicating long-term venting. Previous research on gas mix and isotopic content indicated a regionally complex pattern of biogenic and thermogenic methane sources.

  9. Battery Vent Mechanism And Method

    DOEpatents

    Ching, Larry K. W.

    2000-02-15

    Disclosed herein is a venting mechanism for a battery. The venting mechanism includes a battery vent structure which is located on the battery cover and may be integrally formed therewith. The venting mechanism includes an opening extending through the battery cover such that the opening communicates with a plurality of battery cells located within the battery case. The venting mechanism also includes a vent manifold which attaches to the battery vent structure. The vent manifold includes a first opening which communicates with the battery vent structure opening and second and third openings which allow the vent manifold to be connected to two separate conduits. In this manner, a plurality of batteries may be interconnected for venting purposes, thus eliminating the need to provide separate vent lines for each battery. The vent manifold may be attached to the battery vent structure by a spin-welding technique. To facilitate this technique, the vent manifold may be provided with a flange portion which fits into a corresponding groove portion on the battery vent structure. The vent manifold includes an internal chamber which is large enough to completely house a conventional battery flame arrester and overpressure safety valve. In this manner, the vent manifold, when installed, lessens the likelihood of tampering with the flame arrester and safety valve.

  10. Battery venting system and method

    DOEpatents

    Casale, Thomas J.; Ching, Larry K. W.; Baer, Jose T.; Swan, David H.

    1999-01-05

    Disclosed herein is a venting mechanism for a battery. The venting mechanism includes a battery vent structure which is located on the battery cover and may be integrally formed therewith. The venting mechanism includes an opening extending through the battery cover such that the opening communicates with a plurality of battery cells located within the battery case. The venting mechanism also includes a vent manifold which attaches to the battery vent structure. The vent manifold includes a first opening which communicates with the battery vent structure opening and second and third openings which allow the vent manifold to be connected to two separate conduits. In this manner, a plurality of batteries may be interconnected for venting purposes, thus eliminating the need to provide separate vent lines for each battery. The vent manifold may be attached to the battery vent structure by a spin-welding technique. To facilitate this technique, the vent manifold may be provided with a flange portion which fits into a corresponding groove portion on the battery vent structure. The vent manifold includes an internal chamber which is large enough to completely house a conventional battery flame arrester and overpressure safety valve. In this manner, the vent manifold, when installed, lessens the likelihood of tampering with the flame arrester and safety valve.

  11. Battery venting system and method

    DOEpatents

    Casale, T.J.; Ching, L.K.W.; Baer, J.T.; Swan, D.H.

    1999-01-05

    Disclosed herein is a venting mechanism for a battery. The venting mechanism includes a battery vent structure which is located on the battery cover and may be integrally formed therewith. The venting mechanism includes an opening extending through the battery cover such that the opening communicates with a plurality of battery cells located within the battery case. The venting mechanism also includes a vent manifold which attaches to the battery vent structure. The vent manifold includes a first opening which communicates with the battery vent structure opening and second and third openings which allow the vent manifold to be connected to two separate conduits. In this manner, a plurality of batteries may be interconnected for venting purposes, thus eliminating the need to provide separate vent lines for each battery. The vent manifold may be attached to the battery vent structure by a spin-welding technique. To facilitate this technique, the vent manifold may be provided with a flange portion which fits into a corresponding groove portion on the battery vent structure. The vent manifold includes an internal chamber which is large enough to completely house a conventional battery flame arrester and overpressure safety valve. In this manner, the vent manifold, when installed, lessens the likelihood of tampering with the flame arrester and safety valve. 8 figs.

  12. Coil spring venting arrangement

    DOEpatents

    McCugh, R.M.

    1975-10-21

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

  13. Evaluation of Soil Venting Application

    EPA Pesticide Factsheets

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

  14. Measure Guideline: Passive Vents

    SciTech Connect

    Berger, David; Neri, Robin

    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. Ash Aggregates in Proximal Settings

    NASA Astrophysics Data System (ADS)

    Porritt, L. A.; Russell, K.

    2012-12-01

    Ash aggregates are thought to have formed within and been deposited by the eruption column and plume and dilute density currents and their associated ash clouds. Moist, turbulent ash clouds are considered critical to ash aggregate formation by facilitating both collision and adhesion of particles. Consequently, they are most commonly found in distal deposits. Proximal deposits containing ash aggregates are less commonly observed but do occur. Here we describe two occurrences of vent proximal ash aggregate-rich deposits; the first within a kimberlite pipe where coated ash pellets and accretionary lapilli are found within the intra-vent sequence; and the second in a glaciovolcanic setting where cored pellets (armoured lapilli) occur within <1 km of the vent. The deposits within the A418 pipe, Diavik Diamond Mine, Canada, are the residual deposits within the conduit and vent of the volcano and are characterised by an abundance of ash aggregates. Coated ash pellets are dominant but are followed in abundance by ash pellets, accretionary lapilli and rare cored pellets. The coated ash pellets typically range from 1 - 5 mm in diameter and have core to rim ratios of approximately 10:1. The formation and preservation of these aggregates elucidates the style and nature of the explosive phase of kimberlite eruption at A418 (and other pipes?). First, these pyroclasts dictate the intensity of the kimberlite eruption; it must be energetic enough to cause intense fragmentation of the kimberlite to produce a substantial volume of very fine ash (<62 μm). Secondly, the ash aggregates indicate the involvement of moisture coupled with the presence of dilute expanded eruption clouds. The structure and distribution of these deposits throughout the kimberlite conduit demand that aggregation and deposition operate entirely within the confines of the vent; this indicates that aggregation is a rapid process. Ash aggregates within glaciovolcanic sequences are also rarely documented. The

  16. Airbag vent valve and system

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  17. Safe venting of hydrogen

    SciTech Connect

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

    1990-01-01

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

  18. Enhanced Emergency Smoke Venting

    DTIC Science & Technology

    1988-07-01

    Boeing Airworthiness Offices in both Renton and Everett. The search disclosed at least 26 letters between Boeing and the FAA on the subject of smoke...the ventilation airflow rates and utilizing the effect of the additional outflow valve. .-. 12 FAA Report No. DOT/ FAA /CT-86/41-I, " Aircraft ...lTr !r DOT/ FAA !CT-88/22 Enhanced Emergency FAA Technical Center Sm oke Atlantic City International Airport Venting N.J. 08405 T.DTIC, Q\\SEP 0 21988

  19. Tornado protection by venting

    SciTech Connect

    Cavanagh, C.A.

    1987-01-01

    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.

  20. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Case Iron Soil Pipe and Fittings, or, Silicone Rubber, Low and High Temperature and Tear Resistant... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Vents and venting. 3280.611 Section 3280.611 Housing and Urban Development Regulations Relating to Housing and Urban Development...

  1. 24 CFR 3280.611 - Vents and venting.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... this section and as otherwise required by this standard. (b) Materials—(1) Pipe. Vent piping shall be... listed materials. (2) Fittings. Appropriate fittings shall be used for all changes in direction or size and where pipes are joined. The material and design of vent fittings shall conform to the type...

  2. 40 CFR 63.1426 - Process vent requirements for determining organic HAP concentration, control efficiency, and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a....1426 Process vent requirements for determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a PMPU. (a) Use of a flare. When a flare is used to comply...

  3. 40 CFR 63.1426 - Process vent requirements for determining organic HAP concentration, control efficiency, and...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a... Production § 63.1426 Process vent requirements for determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a PMPU. (a) Use of a flare. When a flare is used...

  4. 40 CFR 63.1426 - Process vent requirements for determining organic HAP concentration, control efficiency, and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a....1426 Process vent requirements for determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a PMPU. (a) Use of a flare. When a flare is used to comply...

  5. 40 CFR 63.1426 - Process vent requirements for determining organic HAP concentration, control efficiency, and...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a....1426 Process vent requirements for determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a PMPU. (a) Use of a flare. When a flare is used to comply...

  6. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... vents must penetrate into tanks at the top of the vapor space, the following methods of venting and the... the vent shall terminate in a gooseneck bend and shall be located at a reasonable height above...

  7. Water vent design for Space Station Freedom

    NASA Astrophysics Data System (ADS)

    Miernik, Janie H.; Worden, Edson A.; Bedard, John E.; Lieu, Bing H.

    1992-07-01

    Space Stadon Freedom (SSF) will be required to vent water during non-quiescent periods. During Man Tended Configuration (MTC), before the Environmental Control and Life Support System (ECLSS) water loop is closed, humidity condensate will be periodically vented. At Permanently Manned Configuration (PMC), water will be vented on contingency if there is excess water on SSF. The thrust due to venting must be minimized to be considered non-propulsive. Also, ice formation and clogging of the vent nozzle must be avoided. Many aspects of the Space Shuttle water vent design were utilized in development of the preliminary SSF water vent design presented in this paper. Design modifications which improved the shuttle vent as well as those necessary for SSF are discussed. The exterior vent location, direction and environment on SSF are unique compared to previous space water vent designs. From data collected in the vent tests and analyses, a finalized SSF water vent design will be developed.

  8. EVALUATION OF SOIL VENTING APPLICATION

    EPA Science Inventory

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

  9. Bacterial Diets of Primary Consumers at Hydrothermal Vents

    NASA Astrophysics Data System (ADS)

    Govenar, B.; Shank, T. M.

    2008-12-01

    Chemical energy produced by mixing hydrothermal fluids and seawater supports dense biological communities on mid-ocean ridges. The base of the food web at deep-sea hydrothermal vents is formed by chemolithoautotrophic bacteria that use the energy from the oxidation of reduced chemicals to fix inorganic carbon into simple sugars. With the exception of a few species that have chemolithoautotropic bacterial symbionts, most of the vent-endemic macrofauna are heterotrophs that feed on free-living bacteria, protists, and other invertebrates. The most abundant and diverse group of primary consumers in hydrothermal vent communities belong to the Gastropoda, particularly the patellomorph limpets. Gastropod densities can be as high as 2000 individuals m-2, and there can be as many as 13 species of gastropods in a single aggregation of the siboglinid tubeworm Riftia pachyptila and more than 40 species along the East Pacific Rise. Some gastropods are ubiquitous and others are found in specific microhabitats, stages of succession, or associated with different foundation species. To determine the mechanisms of species coexistence (e.g. resource partitioning or competition) among hydrothermal vent primary consumers and to track the flow of energy in hydrothermal vent communities, we employed molecular genetic techniques to identify the gut contents of four species of co-occurring hydrothermal vent gastropods, Eulepetopsis vitrea, Lepetodrilus elevatus, Lepetodrilus ovalis and Lepetodrilus pustulosus, collected from a single diffuse-flow hydrothermal vent site on the East Pacific Rise. Unique haplotypes of the 16S gene that fell among the epsilon-proteobacteria were found in the guts of every species, and two species had gut contents that were similar only to epsilon-proteobacteria. Two species had gut contents that also included haplotypes that clustered with delta-proteobacteria, and one species had gut contents that clustered with alpha- proteobacteria. Differences in the diets

  10. Synthesis of silver nanoparticles using methanol and dichloromethane extracts of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts.

    PubMed

    Chitsazi, Mohammad Reza; Korbekandi, Hassan; Asghari, Gholamreza; Bahri Najafi, Rahim; Badii, Akbar; Iravani, Siavash

    2016-01-01

    The objectives were to study the potential of Pulicaria gnaphalodes (Vent.) Boiss. aerial parts in production of nanoparticles and the effect of the extraction solvent on the produced nanoparticles. Methanol and dichloromethane extracts were prepared by percolation of the plant powder. Both the extracts of P. gnaphalodes (Vent.) Boiss. successfully produced small and polydispersed nanoparticles with low aggregates in early hours of the biotransformation. Methanol extract produced spherical and many single nanoparticles, whereas dichloromethane produced porous polyhedral and more aggregated nanoparticles. Methanol extract of this plant seems to be quiet useful for industrial scale production of nanoparticles.

  11. Electricity generation from hydrothermal vents

    NASA Astrophysics Data System (ADS)

    Aryadi, Y.; Rizal, I. S.; Fadhli, M. N.

    2016-09-01

    Hydrothermal vent is a kind of manifestation of geothermal energy on seabed. It produces high temperature fluid through a hole which has a diameter in various range between several inches to tens of meters. Hydrothermal vent is mostly found over ocean ridges. There are some 67000 km of ocean ridges, 13000 of them have been already studied discovering more than 280 sites with geothermal vents. Some of them have a thermal power of up to 60 MWt. These big potential resources of energy, which are located over subsea, have a constraint related to environmental impact to the biotas live around when it becomes an object of exploitation. Organic Rankine Cycle (ORC) is a method of exploiting heat energy to become electricity using organic fluid. This paper presents a model of exploitation technology of hydrothermal vent using ORC method. With conservative calculation, it can give result of 15 MWe by exploiting a middle range diameter of hydrothermal vent in deep of 2000 meters below sea level. The technology provided here really has small impact to the environment. With an output energy as huge as mentioned before, the price of constructing this technology is low considering the empty of cost for drilling as what it should be in conventional exploitation. This paper also presents the comparison in several equipment which is more suitable to be installed over subsea.

  12. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, James K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell.

  13. Modeling of zero gravity venting

    NASA Technical Reports Server (NTRS)

    Merte, H., Jr.

    1984-01-01

    The venting of cylindrical containers partially filled with initially saturated liquids was conducted under zero gravity conditions and compared with an analytical model which determined the effect of interfacial mass transfer on the ullage pressure response during venting. A model is proposed to improve the estimation of the interfacial mass transfer. Duhammel's superposition integral is incorporated in this analysis to approximate the transient temperature response of the interface, treating the liquid as a semiinfinite solid with conduction heat transfer. This approach to estimating interfacial mass transfer gives improved response when compared to previous models. The model still predicts a pressure decrease greater than those in the experiments reported.

  14. Debiasing Crowdsourced Batches

    PubMed Central

    Zhuang, Honglei; Parameswaran, Aditya; Roth, Dan; Han, Jiawei

    2015-01-01

    Crowdsourcing is the de-facto standard for gathering annotated data. While, in theory, data annotation tasks are assumed to be attempted by workers independently, in practice, data annotation tasks are often grouped into batches to be presented and annotated by workers together, in order to save on the time or cost overhead of providing instructions or necessary background. Thus, even though independence is usually assumed between annotations on data items within the same batch, in most cases, a worker's judgment on a data item can still be affected by other data items within the batch, leading to additional errors in collected labels. In this paper, we study the data annotation bias when data items are presented as batches to be judged by workers simultaneously. We propose a novel worker model to characterize the annotating behavior on data batches, and present how to train the worker model on annotation data sets. We also present a debiasing technique to remove the effect of such annotation bias from adversely affecting the accuracy of labels obtained. Our experimental results on both synthetic data and real-world data demonstrate the effectiveness of our proposed method. PMID:26713175

  15. Fill and vent quick disconnect

    NASA Technical Reports Server (NTRS)

    Boerner, R. Y.; Hedrick, R. W.

    1972-01-01

    Hydraulic disconnect coupling on ground serving half of spacecraft refrigeration cooling system employs movable center stem for venting and closing nipple poppet. Self sealing poppet quickly connects cooling system to spacecraft without manual work. Recessed sealing surface insures open poppet when stem retracts.

  16. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Venting. 151.15-5 Section 151.15-5 Shipping COAST GUARD...) Pressure-vacuum venting. A normally closed venting system fitted with a device to automatically limit the pressure or vacuum in the tank to design limits. Pressure-vacuum relief valves shall comply with...

  17. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  18. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  19. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  20. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  1. 33 CFR 159.61 - Vents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Vents. 159.61 Section 159.61 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) POLLUTION MARINE SANITATION DEVICES Design, Construction, and Testing § 159.61 Vents. Vents must be designed and...

  2. 40 CFR 63.1426 - Process vent requirements for determining organic HAP concentration, control efficiency, and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... determining organic HAP concentration, control efficiency, and aggregated organic HAP emission reduction for a... Production § 63.1426 Process vent requirements for determining organic HAP concentration, control efficiency... demonstrate the control efficiency for the flare, if the owner or operator chooses to assume a 98...

  3. GIDEP Batching Tool

    NASA Technical Reports Server (NTRS)

    Fong, Danny; Odell,Dorice; Barry, Peter; Abrahamian, Tomik

    2008-01-01

    This software provides internal, automated search mechanics of GIDEP (Government- Industry Data Exchange Program) Alert data imported from the GIDEP government Web site. The batching tool allows the import of a single parts list in tab-delimited text format into the local JPL GIDEP database. Delimiters from every part number are removed. The original part numbers with delimiters are compared, as well as the newly generated list without the delimiters. The two lists run against the GIDEP imports, and output any matches. This feature only works with Netscape 2.0 or greater, or Internet Explorer 4.0 or greater. The user selects the browser button to choose a text file to import. When the submit button is pressed, this script will import alerts from the text file into the local JPL GIDEP database. This batch tool provides complete in-house control over exported material and data for automated batch match abilities. The batching tool has the ability to match capabilities of the parts list to tables, and yields results that aid further research and analysis. This provides more control over GIDEP information for metrics and reports information not provided by the government site. This software yields results quickly and gives more control over external data from the government site in order to generate other reports not available from the external source. There is enough space to store years of data. The program relates to risk identification and management with regard to projects and GIDEP alert information encompassing flight parts for space exploration.

  4. 40 CFR 63.1428 - Process vent requirements for group determination of PMPUs using a nonepoxide organic HAP to make...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... reduce epoxide emissions, this location shall be at the exit of the combustion, recovery, or recapture... the exit from the batch unit operation. For the purpose of these determinations, the primary condenser... vent procedures in the NESHAP for Group I Polymers and Resins (40 CFR part 63, subpart U), §...

  5. Reactor pressure vessel vented head

    DOEpatents

    Sawabe, J.K.

    1994-01-11

    A head for closing a nuclear reactor pressure vessel shell includes an arcuate dome having an integral head flange which includes a mating surface for sealingly mating with the shell upon assembly therewith. The head flange includes an internal passage extending therethrough with a first port being disposed on the head mating surface. A vent line includes a proximal end disposed in flow communication with the head internal passage, and a distal end disposed in flow communication with the inside of the dome for channeling a fluid therethrough. The vent line is fixedly joined to the dome and is carried therewith when the head is assembled to and disassembled from the shell. 6 figures.

  6. Construction aggregates

    USGS Publications Warehouse

    Tepordei, V.V.

    1995-01-01

    Part of the 1994 Industrial Minerals Review. The production, consumption, and applications of construction aggregates are reviewed. In 1994, the production of construction aggregates, which includes crushed stone and construction sand and gravel combined, increased 7.7 percent to 2.14 Gt compared with the previous year. These record production levels are mostly a result of funding for highway construction work provided by the Intermodal Surface Transportation Efficiency Act of 1991. Demand is expected to increase for construction aggregates in 1995.

  7. Modeling and simulation of fed-batch protein refolding process.

    PubMed

    Dong, Xiao-Yan; Shi, Guang-Quan; Li, Wei; Sun, Yan

    2004-01-01

    The simplified kinetic model that assumes competition between first-order folding and third-order aggregation was used to model the fed-batch refolding of denatured-reduced lysozyme. It was found that the model was able to describe the process at limited concentration ranges, i.e., 1-2 and 5-7 mg mL(-)(1), respectively, at extensive guanidinium chloride (GdmCl) concentrations and controlled concentrations of oxidizing and reducing agents. The folding or aggregation rate constant was different at the two protein concentration ranges and strongly dependent on the denaturant concentration. As a result, both rate constants at the two concentration ranges were expressed as functions of GdmCl concentration. The rate constants determined by fed-batch experiments could be employed for the prediction of the fed-batch process but were not able to be extended to a batch refolding by direct dilution. Computer simulations show that the denaturant concentration and fed-batch flow rate are important factors influencing the refolding yield. Prolonged fed-batch time is beneficial to keep the transient intermediate concentration at a low level and to increase the yield of correctly folded protein. This is of importance when the denaturant concentration in refolding buffer solution is low. Thus, at a low denaturant concentration, fed-batch time should be sufficiently long, whereas at an appropriately high GdmCl concentration, a short fed-batch time or a high feed rate of the denatured protein is effective to give a high refolding yield.

  8. Filtered-vented containment systems. [PWR; BWR

    SciTech Connect

    Benjamin, A S; Walling, H C; Cybulskis, P; DiSalvo, R

    1980-01-01

    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.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...: (1) An integral vent system listed or certified as part of the appliance. (2) A venting system... roof line or outside the wall line may be installed at the site. Sectional venting systems shall...

  11. 46 CFR 151.15-5 - Venting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...) Pressure-vacuum venting. A normally closed venting system fitted with a device to automatically limit the pressure or vacuum in the tank to design limits. Pressure-vacuum relief valves shall comply with the... devices in accordance with the requirements of § 54.15-13 of this chapter. (2) When a...

  12. Progressing batch hydrolysis process

    DOEpatents

    Wright, J.D.

    1985-01-10

    A progressive batch hydrolysis process is disclosed for producing sugar from a lignocellulosic feedstock. It comprises passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with feed stock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feed stock to glucose. The cooled dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, serially fed through a plurality of pre-hydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose. The dilute acid stream containing glucose is cooled after it exits the last prehydrolysis reactor.

  13. Progressing batch hydrolysis process

    DOEpatents

    Wright, John D.

    1986-01-01

    A progressive batch hydrolysis process for producing sugar from a lignocellulosic feedstock, comprising passing a stream of dilute acid serially through a plurality of percolation hydrolysis reactors charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the cellulose component of the feedstock to glucose; cooling said dilute acid stream containing glucose, after exiting the last percolation hydrolysis reactor, then feeding said dilute acid stream serially through a plurality of prehydrolysis percolation reactors, charged with said feedstock, at a flow rate, temperature and pressure sufficient to substantially convert all the hemicellulose component of said feedstock to glucose; and cooling the dilute acid stream containing glucose after it exits the last prehydrolysis reactor.

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

    PubMed

    Nye, Verity; Copley, Jonathan T; Tyler, Paul A

    2013-01-01

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

  15. Spatial Variation in the Population Structure and Reproductive Biology of Rimicaris hybisae (Caridea: Alvinocarididae) at Hydrothermal Vents on the Mid-Cayman Spreading Centre

    PubMed Central

    Nye, Verity; Copley, Jonathan T.; Tyler, Paul A.

    2013-01-01

    The dynamics and microdistribution of faunal assemblages at hydrothermal vents often reflect the fine-scale spatial and temporal heterogeneity of the vent environment. This study examined the reproductive development and population structure of the caridean shrimp Rimicaris hybisae at the Beebe and Von Damm Vent Fields (Mid-Cayman Spreading Centre, Caribbean) using spatially discrete samples collected in January 2012. Rimicaris hybisae is gonochoric and exhibits iteroparous reproduction. Oocyte size-frequency distributions (21-823 µm feret diameters) varied significantly among samples. Embryo development was asynchronous among females, which may result in asynchronous larval release for the populations. Specimens of R. hybisae from the Von Damm Vent Field (2294 m) were significantly larger than specimens from the Beebe Vent Field. Brooding females at Von Damm exhibited greater size-specific fecundity, possibly as a consequence of a non-linear relationship between fecundity and body size that was consistent across both vent fields. Samples collected from several locations at the Beebe Vent Field (4944–4972 m) revealed spatial variability in the sex ratios, population structure, size, and development of oocytes and embryos of this mobile species. Samples from the Von Damm Vent Field and sample J2-613-24 from Beebe Woods exhibited the highest frequencies of ovigerous females and significantly female-biased sex ratios. Environmental variables within shrimp aggregations may influence the distribution of ovigerous females, resulting in a spatially heterogeneous pattern of reproductive development in R. hybisae, as found in other vent taxa. PMID:23555955

  16. Venting of Pressure through Perforated Plates

    DTIC Science & Technology

    1978-09-01

    2623, May 1976. (AD #BO11616L) 4. W.A. Keenan and J.A. Tamareto, "Blaat Envirowaent from Fully and Partially Vented Exploaions in Cubicles". Civil...the scatter of experimental results obtained from vented structures and high explosives. In Reference 4, Keenan and Tamareto developed an equation to...May 1976. (AD #BO11616L) 4. W.A. Keenan and J.A. Tamareto, "Blast Environment from l’ullyand Partially Vented Explosions in Cubicles". Civil

  17. Monitoring arrangement for vented nuclear fuel elements

    DOEpatents

    Campana, Robert J.

    1981-01-01

    In a nuclear fuel reactor core, fuel elements are arranged in a closely packed hexagonal configuration, each fuel element having diametrically opposed vents permitting 180.degree. rotation of the fuel elements to counteract bowing. A grid plate engages the fuel elements and forms passages for communicating sets of three, four or six individual vents with respective monitor lines in order to communicate vented radioactive gases from the fuel elements to suitable monitor means in a manner readily permitting detection of leakage in individual fuel elements.

  18. 30 CFR 77.304 - Explosion release vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  19. 46 CFR 153.355 - PV venting systems.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false PV venting systems. 153.355 Section 153.355 Shipping... Systems § 153.355 PV venting systems. When Table 1 requires a PV venting system, the cargo tank must have a PV valve in its vent line. The PV valve must be located between the tank and any connection...

  20. 46 CFR 153.355 - PV venting systems.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false PV venting systems. 153.355 Section 153.355 Shipping... Systems § 153.355 PV venting systems. When Table 1 requires a PV venting system, the cargo tank must have a PV valve in its vent line. The PV valve must be located between the tank and any connection...

  1. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any vent system segment, including any PV or SR valve, must at no point be less than that of a pipe whose inside... 46 Shipping 5 2011-10-01 2011-10-01 false Venting system flow capacity. 153.358 Section...

  2. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  3. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air...

  4. External Tank GH2 Vent Arm

    NASA Technical Reports Server (NTRS)

    Reichle, G. E.; Glassburn, C. W.

    1985-01-01

    Because the venting of free hydrogen gas to the atmosphere presents an extremely hazardous situation, it was necessary to devise a means for safe, controlled venting of the shuttle external tank gaseous hydrogen during and after liquid hydrogen tank loading. Several design concepts that were considered initially were discarded as unfeasible because of vehicle weight restrictions, high cost, and because the proposed structure was itself deemed a hazard due to the vehicle's nonvertical launch trajectory. These design concepts are discussed. A design employing a support structure/access arm attached to the fixed service structure was finally selected. The various design problems resolved included vent arm disconnect/drop interference, minimizing refurbishment due to launch damage, disconnect reliability, vehicle movement tracking, minimizing vent line pressure drop, and the presence of other vehicle services at the same centralized supply area. Six launches have proven the system to be reliable, efficient, and of nearly zero refurbishment cost.

  5. The geochemical controls on vent fluids from the Lucky Strike vent field, Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Von Damm, K. L.; Bray, A. M.; Buttermore, L. G.; Oosting, S. E.

    1998-08-01

    Hydrothermal vent fluids were collected from the Lucky Strike site at 37°17'N on the Mid-Atlantic Ridge in both 1993 and 1996. Seven vents were sampled with the DSV Alvin in 1993 and six vents were sampled in 1996 using the ROV Jason during the LUSTRE '96 Cruise. As three of the vents were sampled in both 1993 and in 1996, a time series of vent fluid chemistry is also reported. Measured temperatures ranged from 202 to 333°C at the 1618-1726 m depth of the vent field, which is located on Lucky Strike Seamount. These fluids are either equal to or less than the local bottom seawater in chlorinity. While the range in fluid compositions at Lucky Strike is generally within that observed elsewhere, the unusual aspects of the fluid chemistries are the relatively high pH and low Fe, Mn, Li and Zn. We attribute this, as well as an usually low Sr/Ca ratio, to reaction with a highly altered substrate. The high Si and Cu contents suggest a deep, as well as hot, source for these fluids. The fluid compositions therefore suggest formation by super-critical phase separation at a depth not less than 1300 m below the seafloor, and reaction with a relatively oxic, and previously altered, substrate. There is temporal variability in some of the vent fluid compositions as Li, K, Ca and Fe concentrations have increased in some of the vents, as has the Fe/Mn (molar) ratio, although the chlorinities have remained essentially constant from 1993 to 1996. While there is not a simple relationship between vent fluid compositions (or temperatures) and distance from the lava lake at the summit of the seamount, the vent fluids from many of the vents can be shown to be related to others, often at distances >200 m. The most southeasterly vents (Eiffel Tower and the Marker/Mounds vents) are distinct in chlorinity and other chemical parameters from the rest of the vents, although closely related to each other within the southeastern area. Similarly all of the vents not in this one area, appear

  6. Construction aggregates

    USGS Publications Warehouse

    Nelson, T.I.; Bolen, W.P.

    2007-01-01

    Construction aggregates, primarily stone, sand and gravel, are recovered from widespread naturally occurring mineral deposits and processed for use primarily in the construction industry. They are mined, crushed, sorted by size and sold loose or combined with portland cement or asphaltic cement to make concrete products to build roads, houses, buildings, and other structures. Much smaller quantities are used in agriculture, cement manufacture, chemical and metallurgical processes, glass production and many other products.

  7. Construction aggregates

    USGS Publications Warehouse

    Tepordei, V.V.

    1996-01-01

    Part of the Annual Commodities Review 1995. Production of construction aggregates such as crushed stone and construction sand and gravel showed a marginal increase in 1995. Most of the 1995 increases were due to funding for highway construction work. The major areas of concern to the industry included issues relating to wetlands classification and the classification of crystalline silica as a probable human carcinogen. Despite this, an increase in demand is anticipated for 1996.

  8. The vent microbiome: patterns and drivers

    NASA Astrophysics Data System (ADS)

    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.

  9. Data-driven batch schuduling

    SciTech Connect

    Bent, John; Denehy, Tim; Arpaci - Dusseau, Remzi; Livny, Miron; Arpaci - Dusseau, Andrea C

    2009-01-01

    In this paper, we develop data-driven strategies for batch computing schedulers. Current CPU-centric batch schedulers ignore the data needs within workloads and execute them by linking them transparently and directly to their needed data. When scheduled on remote computational resources, this elegant solution of direct data access can incur an order of magnitude performance penalty for data-intensive workloads. Adding data-awareness to batch schedulers allows a careful coordination of data and CPU allocation thereby reducing the cost of remote execution. We offer here new techniques by which batch schedulers can become data-driven. Such systems can use our analytical predictive models to select one of the four data-driven scheduling policies that we have created. Through simulation, we demonstrate the accuracy of our predictive models and show how they can reduce time to completion for some workloads by as much as 80%.

  10. The importance of hydrothermal venting to water-column secondary production in the northeast Pacific

    NASA Astrophysics Data System (ADS)

    Burd, Brenda J.; Thomson, Richard E.

    2015-11-01

    The purpose of this study is to show that seafloor hydrothermal venting in the open northeast Pacific Ocean has a marked impact on secondary biomass and production within the overlying water column. Specifically, we use net tows and concurrently measured acoustic backscatter data collected over six summers to examine the effects of hydrothermal venting from the Endeavour Segment of Juan de Fuca Ridge on macro-zooplankton biomass and production throughout the entire 2000 m depth range. Previous research shows that ontogenetic diapausing migrators and their predators from the upper ocean aggregate above the neutrally buoyant plumes in summer and resume feeding on plume and bottom upwelled particles, resulting in increased zooplankton reproductive output to the upper ocean. Within the limitations of our sampling methodology, net tows reveal a statistically significant exponential decline in total water-column biomass with increasing lateral distance from the vent fields. The acoustic backscatter data show a similar decline, but only below 800 m depth. Near-surface biomass was highly variable throughout the region, but values near vents consistently ranged higher than summer values found elsewhere in the offshore northeast Pacific. Water-column biomass was similar in magnitude above and below 800 m depth throughout the region. Because epiplume biomass can be advected a considerable distance from vent fields, biomass enhancement of the water column from hydrothermal venting may extend considerable distances to the west and northwest of the vent sites, in the prevailing directions of the subsurface flow. Based on the extensive acoustic Doppler current profiler (ADCP) data collected, and the strong correlation between zooplankton production derived from net sample biomass and acoustic backscatter intensity, we estimate that daily macro-zooplankton production in the upper 400 m of the water column within 10 km of the vent fields averages approximately 16% of photosynthetic

  11. Batch compositions for cordierite ceramics

    DOEpatents

    Hickman, David L.

    1994-07-26

    Ceramic products consisting principally of cordierite and a method for making them are provided, the method employing batches comprising a mineral component and a chemical component, the mineral component comprising clay and talc and the chemical component consisting essentially of a combination of the powdered oxides, hydroxides, or hydrous oxides of magnesium, aluminum and silicon. Ceramics made by extrusion and firing of the batches can exhibit low porosity, high strength and low thermal expansion coefficients.

  12. 40 CFR 63.492 - Batch front-end process vents-reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... change within 180 days after the process change is made or with the next Periodic Report, whichever is... made or with the next Periodic Report, whichever is later. The following information shall be submitted... control device other than those specified in § 63.489(b) and listed in Table 6 of this subpart or...

  13. 40 CFR 63.492 - Batch front-end process vents-reporting requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... days after the process change is made or with the next Periodic Report, whichever is later. The owner... next Periodic Report, whichever is later. The following information shall be submitted: (1) A... than those specified in § 63.489(b) and listed in Table 6 of this subpart or requests approval...

  14. 40 CFR 63.1327 - Batch process vents-reporting requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... description of the process change within 180 days after the process change is made or with the next Periodic... with the next Periodic Report, whichever is later. The following information shall be submitted: (1) A... description of the process change within 180 days after the process change is made or with the next...

  15. 40 CFR 63.1324 - Batch process vents-monitoring equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... National Emission Standards for Hazardous Air Pollutant Emissions: Group IV Polymers and Resins § 63.1324...) through (c)(7) of this section, the owner or operator may install an organic monitoring device equipped... or the operating permit application as required in § 63.1335(e)(5) or § 63.1335(e)(8),...

  16. 40 CFR 63.489 - Batch front-end process vents-monitoring equipment.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutant Emissions: Group I Polymers and Resins... may install an organic monitoring device equipped with a continuous recorder. (c) Alternative... Status or the operating permit application as required in § 63.506(e)(5) or § 63.506(e)(8),...

  17. 40 CFR Table 3 to Subpart Ooo of... - Batch Process Vent Monitoring Requirements

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... (gauge or absolute) during carbon bed regeneration cycle(s), and Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. Temperature of the carbon bed... the carbon bed after each regeneration and within 15 minutes of completing any cooling...

  18. 40 CFR 63.1323 - Batch process vents-methods and procedures for group determination.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... K below the boiling point, then emissions from the heating of a vessel shall be calculated as the... section. (A) For the interval from the initial temperature to the temperature 50 K below the boiling point... boiling point. (B) For the interval from the temperature 50 K below the boiling point to the...

  19. 40 CFR 63.2460 - What requirements must I meet for batch process vents?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... temperature lower than the boiling point, you must use the procedures in § 63.1257(d)(2)(i)(C)(3). (2) To... condenser is used for any boiling operations, you must demonstrate that it is properly operated according to... must occur only during the boiling operation. The reference in § 63.1257(d)(3)(iii)(B) to...

  20. 40 CFR 63.2460 - What requirements must I meet for batch process vents?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... temperature lower than the boiling point, you must use the procedures in § 63.1257(d)(2)(i)(C)(3). (2) To... condenser is used for any boiling operations, you must demonstrate that it is properly operated according to... must occur only during the boiling operation. The reference in § 63.1257(d)(3)(iii)(B) to...

  1. 40 CFR 63.1323 - Batch process vents-methods and procedures for group determination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... K below the boiling point, then emissions from the heating of a vessel shall be calculated as the... section. (A) For the interval from the initial temperature to the temperature 50 K below the boiling point... boiling point. (B) For the interval from the temperature 50 K below the boiling point to the...

  2. 40 CFR 63.1323 - Batch process vents-methods and procedures for group determination.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... K below the boiling point, then emissions from the heating of a vessel shall be calculated as the... section. (A) For the interval from the initial temperature to the temperature 50 K below the boiling point... boiling point. (B) For the interval from the temperature 50 K below the boiling point to the...

  3. 40 CFR 63.2460 - What requirements must I meet for batch process vents?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... temperature lower than the boiling point, you must use the procedures in § 63.1257(d)(2)(i)(C)(3). (2) To... condenser is used for any boiling operations, you must demonstrate that it is properly operated according to... must occur only during the boiling operation. The reference in § 63.1257(d)(3)(iii)(B) to...

  4. 40 CFR 63.2460 - What requirements must I meet for batch process vents?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... temperature lower than the boiling point, you must use the procedures in § 63.1257(d)(2)(i)(C)(3). (2) To... condenser is used for any boiling operations, you must demonstrate that it is properly operated according to... must occur only during the boiling operation. The reference in § 63.1257(d)(3)(iii)(B) to...

  5. 40 CFR 63.1323 - Batch process vents-methods and procedures for group determination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... K below the boiling point, then emissions from the heating of a vessel shall be calculated as the... section. (A) For the interval from the initial temperature to the temperature 50 K below the boiling point... boiling point. (B) For the interval from the temperature 50 K below the boiling point to the...

  6. 40 CFR 63.2460 - What requirements must I meet for batch process vents?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... temperature lower than the boiling point, you must use the procedures in § 63.1257(d)(2)(i)(C)(3). (2) To... condenser is used for any boiling operations, you must demonstrate that it is properly operated according to... must occur only during the boiling operation. The reference in § 63.1257(d)(3)(iii)(B) to...

  7. 40 CFR 63.1323 - Batch process vents-methods and procedures for group determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... K below the boiling point, then emissions from the heating of a vessel shall be calculated as the... section. (A) For the interval from the initial temperature to the temperature 50 K below the boiling point... boiling point. (B) For the interval from the temperature 50 K below the boiling point to the...

  8. 40 CFR Table 3 to Subpart Ooo of... - Batch Process Vent Monitoring Requirements

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... specified in § 63.1416(d). a Carbon adsorber a Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. Temperature of the carbon...

  9. 40 CFR Table 3 to Subpart Ooo of... - Batch Process Vent Monitoring Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. Temperature of the carbon bed after regeneration and within 15 minutes of completing any cooling...

  10. 40 CFR 63.489 - Batch front-end process vents-monitoring equipment.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., nitrogen flow, or pressure monitoring device having an accuracy of ±10 percent of the flow rate, level, or pressure, or better, capable of recording the total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) for each regeneration cycle; and a carbon bed temperature monitoring device,...

  11. 40 CFR Table 3 to Subpart Ooo of... - Batch Process Vent Monitoring Requirements

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... specified in § 63.1416(d). a Carbon adsorber a Total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. Temperature of the carbon...

  12. 40 CFR Table 3 to Subpart Ooo of... - Batch Process Vent Monitoring Requirements

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... or nitrogen flow, or pressure (gauge or absolute) during carbon bed regeneration cycle(s), and Record the total regeneration steam flow or nitrogen flow, or pressure for each carbon bed regeneration cycle. Temperature of the carbon bed after regeneration and within 15 minutes of completing any cooling...

  13. 40 CFR 63.1324 - Batch process vents-monitoring equipment.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    .... (7) Where a carbon adsorber is used, an integrating regeneration steam flow or nitrogen flow, or... better, capable of recording the total regeneration steam flow or nitrogen flow, or pressure (gauge or absolute) for each regeneration cycle; and a carbon bed temperature monitoring device, capable of...

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

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank vents and carburetor vapor vents. 29.975 Section 29.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System §...

  15. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank vents and carburetor vapor vents. 29.975 Section 29.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System §...

  16. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel tank vents and carburetor vapor vents. 25.975 Section 25.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System §...

  17. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank vents and carburetor vapor vents. 25.975 Section 25.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System §...

  18. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel tank vents and carburetor vapor vents. 29.975 Section 29.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System §...

  19. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Fuel tank vents and carburetor vapor vents. 29.975 Section 29.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Powerplant Fuel System §...

  20. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Fuel tank vents and carburetor vapor vents. 25.975 Section 25.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System §...

  1. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Fuel tank vents and carburetor vapor vents. 25.975 Section 25.975 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Powerplant Fuel System §...

  2. 14 CFR 23.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... will constitute a fire hazard or from which fumes may enter personnel compartments; and (7) Vents must... a separate vent line to lead vapors back to the top of one of the fuel tanks. If there is more than... line must lead back to the fuel tank to be used first, unless the relative capacities of the tanks...

  3. 14 CFR 25.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... may end at any point— (i) Where the discharge of fuel from the vent outlet would constitute a fire... carburetor with vapor elimination connections must have a vent line to lead vapors back to one of the fuel... return line must lead back to the fuel tank used for takeoff and landing....

  4. 14 CFR 29.975 - Fuel tank vents and carburetor vapor vents.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... end at any point— (i) Where the discharge of fuel from the vent outlet would constitute a fire hazard... with vapor elimination connections must have a vent line to lead vapors back to one of the fuel tanks... line must lead back to the fuel tank used for takeoff and landing....

  5. ANALYSIS OF VENTING OF A RESIN SLURRY

    SciTech Connect

    Laurinat, J.; Hensel, S.

    2012-03-27

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

  6. Effects of Vent Asymmetry on Explosive Eruptions

    NASA Astrophysics Data System (ADS)

    Sim, S.; Ogden, D. E.

    2012-12-01

    Current computer models of volcanic eruptions are typically based on symmetric vent and conduit geometries. However, in natural settings, these features are rarely perfectly symmetric. For example, the May 18, 1980 eruption of Mount St Helens (MSH) took place through a highly asymmetrical crater due to the preceding landslide and subsequent vent erosion. In supersonic, high pressure eruptions, such as what may have occurred at MSH, vent and crater asymmetry can strongly affect the directionality of the gas-thrust region. These effects on eruption direction may have implications for the formation of lateral blasts and pyroclastic density currents (PDCs). Here, we present preliminary results from numerical simulations using CartaBlanca, a Java based simulation tool for non-linear physics as developed at Los Alamos National Laboratory. Using 2D time-dependent simulations of explosive volcanic eruptions, we study the effects of vent asymmetry on a variety of eruptive conditions. Preliminary results suggest that asymmetric vent shape may provide an additional mechanism for the formation of lateral blasts and PDCs.

  7. Medium Fidelity Simulation of Oxygen Tank Venting

    NASA Technical Reports Server (NTRS)

    Sweet, Adam; Kurien, James; Lau, Sonie (Technical Monitor)

    2001-01-01

    The item to he cleared is a medium-fidelity software simulation model of a vented cryogenic tank. Such tanks are commonly used to transport cryogenic liquids such as liquid oxygen via truck, and have appeared on liquid-fueled rockets for decades. This simulation model works with the HCC simulation system that was developed by Xerox PARC and NASA Ames Research Center. HCC has been previously cleared for distribution. When used with the HCC software, the model generates simulated readings for the tank pressure and temperature as the simulated cryogenic liquid boils off and is vented. Failures (such as a broken vent valve) can be injected into the simulation to produce readings corresponding to the failure. Release of this simulation will allow researchers to test their software diagnosis systems by attempting to diagnose the simulated failure from the simulated readings. This model does not contain any encryption software nor can it perform any control tasks that might be export controlled.

  8. Hydrothermal vent yields multitude of manganese

    NASA Astrophysics Data System (ADS)

    A rising plume of water from an active submarine hydrothermal spring discovered 500 km west of Newport, Ore., contains the highest concentrations of manganese yet reported, according to researchers at the U.S. Geological Survey in Menlo Park and at the University of Washington in Seattle. The vent, one of many submarine springs that have deposited large deposits of zinc- and silver-rich metals along the Juan de Fuca Ridge, may be a source of renewable minerals.‘The discovery of the active water discharge from the vent sites is particularly significant because it indicates that the polymetallic deposits are still being deposited and may represent a renewable mineral deposit,’ according to William R. Normark, a marine geologist with the USGS and chief scientist aboard the S. P. Lee, the USGS research ship that was used to collect water samples above the hydrothermal vent.

  9. Investigations Into Tank Venting for Propellant Resupply

    NASA Technical Reports Server (NTRS)

    Hearn, H. C.; Harrison, Robert A. (Technical Monitor)

    2002-01-01

    Models and simulations have been developed and applied to the evaluation of propellant tank ullage venting, which is integral to one approach for propellant resupply. The analytical effort was instrumental in identifying issues associated with resupply objectives, and it was used to help develop an operational procedure to accomplish the desired propellant transfer for a particular storable bipropellant system. Work on the project was not completed, and several topics have been identified as requiring further study; these include the potential for liquid entrainment during the low-g and thermal/freezing effects in the vent line and orifice. Verification of the feasibility of this propellant venting and resupply approach still requires additional analyses as well as testing to investigate the fluid and thermodynamic phenomena involved.

  10. Vented Cavity Radiant Barrier Assembly And Method

    DOEpatents

    Dinwoodie, Thomas L.; Jackaway, Adam D.

    2000-05-16

    A vented cavity radiant barrier assembly (2) includes a barrier (12), typically a PV module, having inner and outer surfaces (18, 22). A support assembly (14) is secured to the barrier and extends inwardly from the inner surface of the barrier to a building surface (14) creating a vented cavity (24) between the building surface and the barrier inner surface. A low emissivity element (20) is mounted at or between the building surface and the barrier inner surface. At least part of the cavity exit (30) is higher than the cavity entrance (28) to promote cooling air flow through the cavity.

  11. Hydrothermal vents and the origin of life.

    PubMed

    Martin, William; Baross, John; Kelley, Deborah; Russell, Michael J

    2008-11-01

    Submarine hydrothermal vents are geochemically reactive habitats that harbour rich microbial communities. There are striking parallels between the chemistry of the H(2)-CO(2) redox couple that is present in hydrothermal systems and the core energy metabolic reactions of some modern prokaryotic autotrophs. The biochemistry of these autotrophs might, in turn, harbour clues about the kinds of reactions that initiated the chemistry of life. Hydrothermal vents thus unite microbiology and geology to breathe new life into research into one of biology's most important questions - what is the origin of life?

  12. Quantifying diffuse and discrete venting at the Tour Eiffel vent site, Lucky Strike hydrothermal field

    NASA Astrophysics Data System (ADS)

    Mittelstaedt, Eric; EscartíN, Javier; Gracias, Nuno; Olive, Jean-Arthur; Barreyre, Thibaut; Davaille, Anne; Cannat, Mathilde; Garcia, Rafael

    2012-04-01

    The relative heat carried by diffuse versus discrete venting of hydrothermal fluids at mid-ocean ridges is poorly constrained and likely varies among vent sites. Estimates of the proportion of heat carried by diffuse flow range from 0% to 100% of the total axial heat flux. Here, we present an approach that integrates imagery, video, and temperature measurements to accurately estimate this partitioning at a single vent site, Tour Eiffel in the Lucky Strike hydrothermal field along the Mid-Atlantic Ridge. Fluid temperatures, photographic mosaics of the vent site, and video sequences of fluid flow were acquired during the Bathyluck'09 cruise (Fall, 2009) and the Momarsat'10 cruise (Summer, 2010) to the Lucky Strike hydrothermal field by the ROV Victor6000 aboard the French research vessel the "Pourquoi Pas"? (IFREMER, France). We use two optical methods to calculate the velocities of imaged hydrothermal fluids: (1) for diffuse venting, Diffuse Flow Velocimetry tracks the displacement of refractive index anomalies through time, and (2) for discrete jets, Particle Image Velocimetry tracks eddies by cross-correlation of pixel intensities between subsequent images. To circumvent video blurring associated with rapid velocities at vent orifices, exit velocities at discrete vents are calculated from the best fit of the observed velocity field to a model of a steady state turbulent plume where we vary the model vent radius and fluid exit velocity. Our results yield vertical velocities of diffuse effluent between 0.9 cm s-1 and 11.1 cm s-1 for fluid temperatures between 3°C and 33.5°C above that of ambient seawater, and exit velocities of discrete jets between 22 cm s-1 and 119 cm s-1 for fluid temperatures between 200°C and 301°C above ambient seawater. Using the calculated fluid velocities, temperature measurements, and photo mosaics of the actively venting areas, we calculate a heat flux due to diffuse venting from thin fractures of 3.15 ± 2.22 MW, discrete venting of

  13. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... relief valve and the vent outlets. (h) Provisions shall be made to drain condensate from the vent header piping. Special precautions shall insure that condensate does not accumulate at or near the relief...

  14. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... relief valve and the vent outlets. (h) Provisions shall be made to drain condensate from the vent header piping. Special precautions shall insure that condensate does not accumulate at or near the relief...

  15. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... relief valve and the vent outlets. (h) Provisions shall be made to drain condensate from the vent header piping. Special precautions shall insure that condensate does not accumulate at or near the relief...

  16. 40 CFR 63.690 - Standards: Process vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... process vent through a closed-vent system to a control device that meets the standards specified in § 63... a control device; however, a second condenser or other organic recovery device that is...

  17. Batching System for Superior Service

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Veridian's Portable Batch System (PBS) was the recipient of the 1997 NASA Space Act Award for outstanding software. A batch system is a set of processes for managing queues and jobs. Without a batch system, it is difficult to manage the workload of a computer system. By bundling the enterprise's computing resources, the PBS technology offers users a single coherent interface, resulting in efficient management of the batch services. Users choose which information to package into "containers" for system-wide use. PBS also provides detailed system usage data, a procedure not easily executed without this software. PBS operates on networked, multi-platform UNIX environments. Veridian's new version, PBS Pro,TM has additional features and enhancements, including support for additional operating systems. Veridian distributes the original version of PBS as Open Source software via the PBS website. Customers can register and download the software at no cost. PBS Pro is also available via the web and offers additional features such as increased stability, reliability, and fault tolerance.A company using PBS can expect a significant increase in the effective management of its computing resources. Tangible benefits include increased utilization of costly resources and enhanced understanding of computational requirements and user needs.

  18. Simulated Batch Production of Penicillin

    ERIC Educational Resources Information Center

    Whitaker, A.; Walker, J. D.

    1973-01-01

    Describes a program in applied biology in which the simulation of the production of penicillin in a batch fermentor is used as a teaching technique to give students experience before handling a genuine industrial fermentation process. Details are given for the calculation of minimum production cost. (JR)

  19. Physicochemical Characteristics of Transferon™ Batches.

    PubMed

    Medina-Rivero, Emilio; Vallejo-Castillo, Luis; Vázquez-Leyva, Said; Pérez-Sánchez, Gilberto; Favari, Liliana; Velasco-Velázquez, Marco; Estrada-Parra, Sergio; Pavón, Lenin; Pérez-Tapia, Sonia Mayra

    2016-01-01

    Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes.

  20. Physicochemical Characteristics of Transferon™ Batches

    PubMed Central

    Pérez-Sánchez, Gilberto; Favari, Liliana; Estrada-Parra, Sergio

    2016-01-01

    Transferon, a biotherapeutic agent that has been used for the past 2 decades for diseases with an inflammatory component, has been approved by regulatory authorities in Mexico (COFEPRIS) for the treatment of patients with herpes infection. The active pharmaceutical ingredient (API) of Transferon is based on polydispersion of peptides that have been extracted from lysed human leukocytes by a dialysis process and a subsequent ultrafiltration step to select molecules below 10 kDa. To physicochemically characterize the drug product, we developed chromatographic methods and an SDS-PAGE approach to analyze the composition and the overall variability of Transferon. Reversed-phase chromatographic profiles of peptide populations demonstrated batch-to-batch consistency from 10 representative batches that harbored 4 primary peaks with a relative standard deviation (RSD) of less than 7%. Aminogram profiles exhibited 17 proteinogenic amino acids and showed that glycine was the most abundant amino acid, with a relative content of approximately 18%. Further, based on their electrophoretic migration, the peptide populations exhibited a molecular mass of about 10 kDa. Finally, we determined the Transferon fingerprint using a mass spectrometry tool. Because each batch was produced from independent pooled buffy coat samples from healthy donors, supplied by a local blood bank, our results support the consistency of the production of Transferon and reveal its peptide identity with regard to its physicochemical attributes. PMID:27525277

  1. NDA BATCH 2002-02

    SciTech Connect

    Lawrence Livermore National Laboratory

    2009-12-09

    QC sample results (daily background checks, 20-gram and 100-gram SGS drum checks) were within acceptable criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on 5 drums with IDs LL85101099TRU, LL85801147TRU, LL85801109TRU, LL85300999TRU and LL85500979TRU. All replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. Note that the batch covered 5 weeks of SGS measurements from 23-Jan-2002 through 22-Feb-2002. Data packet for SGS Batch 2002-02 generated using gamma spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with established control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable. An Expert Review was performed on the data packet between 28-Feb-02 and 09-Jul-02 to check for potential U-235, Np-237 and Am-241 interferences and address drum cases where specific scan segments showed Se gamma ray transmissions for the 136-keV gamma to be below 0.1 %. Two drums in the batch showed Pu-238 at a relative mass ratio more than 2% of all the Pu isotopes.

  2. Formulation to obtain the most reliable aggregate mix with quantity and other constraints

    NASA Astrophysics Data System (ADS)

    Gehlot, Hemant; Chakroborty, Partha

    2016-09-01

    The aggregate batch mixing problem determines the proportion (or relative masses) in which aggregate batches with different gradations are to be blended so as to achieve a target mix with a given gradation. As shown in previous studies, the gradation of a batch is not homogeneous and should be considered stochastic. Also, when batches are blended in the field there are random variations in the masses or proportions of individual batches in the mix. Assuming batch gradation and blend masses as stochastic implies that the notion of a mix (blend) satisfying the gradation of a target mix becomes stochastic. In such a framework, every mix has a reliability with which it satisfies the definition of the target mix. In addition, a mix is also required to satisfy various restrictions. This article presents an optimization formulation to determine the most reliable mix while satisfying restrictions on available quantity, budget, etc.

  3. Batch manufacturing: Six strategic needs

    SciTech Connect

    Ash, R.H.; Chappell, D.A.

    1995-08-01

    Since the advent of industrial digital control systems in the mid-1970s, industry has had the promise of integrated, configurable digital batch control systems to replace the morass of electromechanical devices like relays and stepping switches, recorders, and indicators which comprised the components of previous generations of batch control systems - the {open_quotes}monolithic monsters{close_quotes} of the 1960s and earlier. To help fulfill that promise, there have been many wide-ranging proprietary automation solutions for batch control since 1975, many of them technically excellent. However, even the best examples suffered from the lack of a common language and unifying concept permitting separate systems to be interconnected and work together. Today, some 20 years after the digital revolution began, industry has microprocessors, memory chips, data highways, and other marvelous technology to help automate the control of discontinuous processes. They also are on the way to having an accepted standard for batch automation, ISA S88. Batching systems are at once conceptually simple but executionally complex. The notion of adding ingredients one at a time to a vat, mixing, and then processing into final form is as old as the stone age. Every homemaker on earth, male or female, is familiar with how to follow a recipe to create some sumptuous item of culinary delight. Food recipes, so familiar and ubiquitous, are really just microcosms of the S88 recipe standard. They contain the same components: (1) Header (name and description of item being prepared, sometimes serving size); (2) Formula (list and amount of ingredients); (3) Equipment requirements (pans, mixing and cooking equipment); (4) Procedure (description of order of ingredient addition, mixing and other processing steps, baking/cooling time, and other processing steps); and (5) Other information (safety, cautions, and other miscellaneous instructions).

  4. Flow fields of low pressure vent exhausts

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.

    1989-01-01

    The flow field produced by low pressure gas vents are described based on experimental data obtained from tests in a large vacuum chamber. The gas density, pressure, and flux at any location in the flow field are calculated based on the vent plume description and the knowledge of the flow rate and velocity of the venting gas. The same parameters and the column densities along a specified line of sight traversing the plume are also obtained and shown by a computer-generated graphical representation. The fields obtained with a radially scanning Pitot probe within the exhausting gas are described by a power of the cosine function, the mass rate and the distance from the exit port. The field measurements were made for gas at pressures ranging from 2 to 50 torr venting from pipe fittings with diameters of 3/16 inch to 1-1/2 inches I.D. (4.76 mm to 38.1 mm). The N(2) mass flow rates ranged from 2E-4 to 3.7E-1 g/s.

  5. Flow fields of low pressure vent exhausts

    NASA Technical Reports Server (NTRS)

    Scialdone, John J.

    1990-01-01

    The flow field produced by low pressure gas vents are described based on experimental data obtained from tests in a large vacuum chamber. The gas density, pressure, and flux at any location in the flow field are calculated based on the vent plume description and the knowledge of the flow rate and velocity of the venting gas. The same parameters and the column densities along a specified line of sight traversing the plume are also obtained and shown by a computer generated graphical representation. The fields obtained with a radically scanning Pitot probe within the exhausting gas are described by a power of the cosine function, the mass rate, and the distance from the exit port. The field measurements were made for gas at pressures ranging from 2 to 50 torr venting from pipe fittings with diameters to 3/16 to 1-1/2 inches I.D. (4.76 to 38.1 mm). The N2 mass flow rates ranged from 2E-4 to 3.7E-1 g/s.

  6. Electrochemical cell having improved pressure vent

    DOEpatents

    Dean, Kevin; Holland, Arthur; Fillmore, Donn

    1993-01-01

    The electrochemical cell of the instant invention includes a case having a gas outlet, one or more positive electrodes positioned within the case, one or more negative electrodes positioned within the case electrode separators positioned between the positive and negative electrodes, electrolyte positioned within the case, and a pressure vent for releasing internal pressure occurring in the case to the surrounding atmosphere. The pressure vent is affixed to the case covering the gas outlet, the pressure vent includes a vent housing having a hollow interior area in gaseous communication with the surrounding atmosphere and the interior of the case via the gas outlet, a pressure release piston positioned within the hollow interior area, the pressure release piston sized to surround the gas outlet and having a seal groove configured to encapsulate all but one surface of a seal mounted within the seal groove, leaving the non-encapsulated surface of the seal exposed, and a compression spring positioned to urge the pressure release piston to compress the seal in the seal groove and block the gas outlet in the case.

  7. Computer controlled vent and pressurization system

    NASA Technical Reports Server (NTRS)

    Cieslewicz, E. J.

    1975-01-01

    The Centaur space launch vehicle airborne computer, which was primarily used to perform guidance, navigation, and sequencing tasks, was further used to monitor and control inflight pressurization and venting of the cryogenic propellant tanks. Computer software flexibility also provided a failure detection and correction capability necessary to adopt and operate redundant hardware techniques and enhance the overall vehicle reliability.

  8. Preoperational test report, vent building ventilation system

    SciTech Connect

    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.

  9. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  10. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  11. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  12. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  13. 46 CFR 98.25-70 - Venting.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Venting. 98.25-70 Section 98.25-70 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS SPECIAL CONSTRUCTION, ARRANGEMENT, AND OTHER PROVISIONS FOR CERTAIN DANGEROUS CARGOES IN BULK Anhydrous Ammonia in Bulk §...

  14. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... ventilation shall be installed within a horizontal distance of not more than ten feet from the vertical...

  15. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... ventilation shall be installed within a horizontal distance of not more than ten feet from the vertical...

  16. 46 CFR 153.358 - Venting system flow capacity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Venting system flow capacity. 153.358 Section 153.358... CARRYING BULK LIQUID, LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Design and Equipment Cargo Venting Systems § 153.358 Venting system flow capacity. (a) The cross-sectional flow area of any...

  17. 46 CFR 182.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Vent pipes for fuel tanks. 182.450 Section 182.450... TONS) MACHINERY INSTALLATION Specific Machinery Requirements § 182.450 Vent pipes for fuel tanks. (a) Each unpressurized fuel tank must be fitted with a vent pipe connected to the highest point of the...

  18. 14 CFR 27.975 - Fuel tank vents.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Fuel tank vents. 27.975 Section 27.975... STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Fuel System § 27.975 Fuel tank vents. (a) Each fuel tank... system must be designed to minimize spillage of fuel through the vents to an ignition source in the...

  19. 33 CFR 183.520 - Fuel tank vent systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  20. 46 CFR 153.463 - Vent system discharges.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Vent system discharges. 153.463 Section 153.463 Shipping... Requirements for Flammable Or Combustible Cargoes § 153.463 Vent system discharges. The discharge of a venting system must be at least 10 m (approx. 32.8 ft) from an ignition source if: (a) The cargo tank is...

  1. 46 CFR 153.463 - Vent system discharges.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Vent system discharges. 153.463 Section 153.463 Shipping... Requirements for Flammable Or Combustible Cargoes § 153.463 Vent system discharges. The discharge of a venting system must be at least 10 m (approx. 32.8 ft) from an ignition source if: (a) The cargo tank is...

  2. 40 CFR 63.1429 - Process vent monitoring requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Process vent monitoring requirements....1429 Process vent monitoring requirements. (a) Monitoring equipment requirements. The owner or operator... vent control requirements in § 63.1425(b)(1), (b)(2), (c)(1), (c)(3), or (d) shall install...

  3. 40 CFR 63.1429 - Process vent monitoring requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 11 2010-07-01 2010-07-01 true Process vent monitoring requirements....1429 Process vent monitoring requirements. (a) Monitoring equipment requirements. The owner or operator... vent control requirements in § 63.1425(b)(1), (b)(2), (c)(1), (c)(3), or (d) shall install...

  4. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 25 2010-07-01 2010-07-01 false Standards: Process vents. 264.1032 Section 264.1032 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner...

  5. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 26 2011-07-01 2011-07-01 false Standards: Process vents. 264.1032 Section 264.1032 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner...

  6. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 27 2012-07-01 2012-07-01 false Standards: Process vents. 264.1032 Section 264.1032 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner...

  7. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 26 2014-07-01 2014-07-01 false Standards: Process vents. 264.1032 Section 264.1032 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner...

  8. 40 CFR 264.1032 - Standards: Process vents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 27 2013-07-01 2013-07-01 false Standards: Process vents. 264.1032 Section 264.1032 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) SOLID WASTES... Air Emission Standards for Process Vents § 264.1032 Standards: Process vents. (a) The owner...

  9. 33 CFR 183.520 - Fuel tank vent systems.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Fuel tank vent systems. 183.520...) BOATING SAFETY BOATS AND ASSOCIATED EQUIPMENT Fuel Systems Equipment Standards § 183.520 Fuel tank vent systems. (a) Each fuel tank must have a vent system that prevents pressure in the tank from exceeding...

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... turbine engine subject to the subpart. This paragraph is directed at the elimination of...

  11. 14 CFR 34.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... FUEL VENTING AND EXHAUST EMISSION REQUIREMENTS FOR TURBINE ENGINE POWERED AIRPLANES Engine Fuel Venting Emissions (New and In-Use Aircraft Gas Turbine Engines) § 34.11 Standard for fuel venting emissions. (a) No... turbine engine subject to the subpart. This paragraph is directed at the elimination of...

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

    NASA Astrophysics Data System (ADS)

    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

  13. Discovery of a black smoker vent field and vent fauna at the Arctic Mid-Ocean Ridge.

    PubMed

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

    2010-11-23

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

  14. Discovery of a black smoker vent field and vent fauna at the Arctic Mid-Ocean Ridge

    PubMed Central

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

    2010-01-01

    The Arctic Mid-Ocean Ridge (AMOR) represents one of the most slow-spreading ridge systems on Earth. Previous attempts to locate hydrothermal vent fields and unravel the nature of venting, as well as the provenance of vent fauna at this northern and insular termination of the global ridge system, have been unsuccessful. Here, we report the first discovery of a black smoker vent field at the AMOR. The field is located on the crest of an axial volcanic ridge (AVR) and is associated with an unusually large hydrothermal deposit, which documents that extensive venting and long-lived hydrothermal systems exist at ultraslow-spreading ridges, despite their strongly reduced volcanic activity. The vent field hosts a distinct vent fauna that differs from the fauna to the south along the Mid-Atlantic Ridge. The novel vent fauna seems to have developed by local specialization and by migration of fauna from cold seeps and the Pacific. PMID:21119639

  15. NDA Batch 2002-13

    SciTech Connect

    Hollister, R

    2009-09-17

    QC sample results (daily background check drum and 100-gram SGS check drum) were within acceptance criteria established by WIPP's Quality Assurance Objectives for TRU Waste Characterization. Replicate runs were performed on drum LL85501243TRU. Replicate measurement results are identical at the 95% confidence level as established by WIPP criteria. HWM NCAR No. 02-1000168 issued on 17-Oct-2002 regarding a partially dislodged Cd sheet filter on the HPGe coaxial detector. This physical geometry occurred on 01-Oct-2002 and was not corrected until 10-Oct-2002, during which period is inclusive of the present batch run of drums. Per discussions among the Independent Technical Reviewer, Expert Reviewer and the Technical QA Supervisor, as well as in consultation with John Fleissner, Technical Point of Contact from Canberra, the analytical results are technically reliable. All QC standard runs during this period were in control. Data packet for SGS Batch 2002-13 generated using passive gamma-ray spectroscopy with the Pu Facility SGS unit is technically reasonable. All QC samples are in compliance with establiShed control limits. The batch data packet has been reviewed for correctness, completeness, consistency and compliance with WIPP's Quality Assurance Objectives and determined to be acceptable.

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

    SciTech Connect

    Lutz, R.A.; Kennish, M.J. )

    1993-08-01

    The present article reviews studies of the past 15 years of active and inactive hydrothermal vents. The focus of the discussion is on the ecology of the biological communities inhabiting hydrothermal vents. These communities exhibit high densities and biomass, low species diversity, rapid growth rates, and high metabolic rates. The authors attempt to relate the biology of hydrothermal vent systems to geology. Future directions for hydrothermal vent research are suggested. Since many vent populations are dependent on hydrothermal fluids and are consequently unstable, both short- and long-term aspects of the ecology of the vent organisms and the influence of chemical and geological factors on the biology of vent systems need to be established. 200 refs., 28 figs.

  17. Inside the Vent of the 2011-2012 Cordón Caulle Eruption, Chile: The Nature of a Rhyolitic Ash Plume Source

    NASA Astrophysics Data System (ADS)

    Tuffen, H.; Castro, J. M.; Schipper, C. I.; Wadsworth, F. B.

    2014-12-01

    The 2011-2012 activity at Cordon Caulle has provided an unprecedented opportunity to observe a sustained explosive rhyolitic eruption. An initial 27 hour Plinian phase commenced on 4 June 2011, followed by ten months of hybrid explosive-effusive activity, which generated disruptive ≤6 km ash plumes. In January 2012 our close observations of the active vent[1] revealed how episodic release of gas and ash from several sub-vents on an incipient lava dome (Fig. 1b) merged to form a sustained ash plume. Sub-vents ranged from metric point sources to arcuate fractures (>10 m) in the dome carapace. We visited the vent in January 2014, and found two ~50 m-wide, rubble-strewn vent areas adjacent to pancake-like obsidian domes, all within a breached, ~100 m-high tuff cone. Vent areas consist of fractured obsidian lava strewn by loose, rotated lava blocks ≤5 m across. Prominent red fracture surfaces (Fig. 1 d,e) occur in both the in-situ lava and the blocky veneer; these closely correspond to the type of sub-vents observed in 2012[1]. They range from smooth, curviplanar surfaces extending over several m to complex smaller-scale surfaces that follow pre-existing cooling joints in the lava carapace. In-situ fracture surfaces display prominent, predominantly vertical grooves and impact marks, but negligible displacement. Surfaces are coated by μm-mm thick veneers of fine-grained ash, to which larger ash-coated clasts have adhered. Veneer thickness and sintering degree strongly decrease towards the upper carapace of the lava. SEM analysis of ash veneers reveals 1) a high proportion of sub-micron clasts, 2) strong clast sintering, 3) abundant ash aggregation textures spanning submicron-mm scales, and 4) local surface scouring and corrosion of glass and phenocrysts. During ash venting the smallest particles are preferentially trapped on fracture surfaces and rapidly sintered, encouraging sub-vent blockage. Extensive ash aggregation may have been electrostatically aided, with

  18. Provisions for containment venting in Germany

    SciTech Connect

    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.

  19. Sparger system for MMH-helium vents

    NASA Technical Reports Server (NTRS)

    Rakow, A.

    1983-01-01

    Based on a calculated vent flow rate and MMH concentration, a TI-59 program was run to determine total sparger hole area for a given sparger inlet pressure. Hole diameter is determined from a mass transfer analysis in the holding tank to achieve complete capture of MMH. In addition, based on oxidation kinetics and vapor pressure data, MMh atmospheric concentrations are determined 2 ft above the holding tank.

  20. Comparative Study of Vented vs. Unvented Crawlspaces

    SciTech Connect

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

    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.

  1. Effects of Vent Asymmetry on Steady and Unsteady Eruption Dynamics

    NASA Astrophysics Data System (ADS)

    Sim, S.; Ogden, D.

    2013-12-01

    Models of volcanic eruptions are typically based on symmetric vent and conduit geometries. However, in natural settings, these features are rarely perfectly symmetric. For example, the May 18, 1980 eruption of Mount St Helens (MSH) took place through a highly asymmetrical crater due to the preceding landslide and subsequent vent erosion. In supersonic, high-pressure eruptions, such as what may have occurred at MSH, vent and crater asymmetry can strongly affect the directionality of the eruption. Here we explore flow dynamics resulting from a supersonic, high-pressure eruption though an asymmetric volcanic vent and a symmetric vent using a both unsteady numerical simulations and semi-analytical steady-state models. Preliminary results from both methods suggest that asymmetric vent shape may provide a first-order effect on dynamics of the initial phases of explosive eruptions.

  2. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  3. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  4. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  5. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  6. 46 CFR 153.353 - High velocity vents.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false High velocity vents. 153.353 Section 153.353 Shipping... Systems § 153.353 High velocity vents. The discharge point of a B/3 or 4m venting system must be located..., unimpeded jet; (b) The jet has a minimum exit velocity of 30 m/sec (approx. 98.4 ft/sec); and (c) The...

  7. Characterization of large, autotrophic Beggiatoa spp. abundant at hydrothermal vents of the Guaymas Basin

    SciTech Connect

    Nelson, D.C. ); Wirsen, C.O.; Jannasch, H.W. )

    1989-11-01

    Filamentous bacteria, identified as members of the genus Beggiatoa by gliding motility and internal globules of elemental sulfur, occur in massive aggregations at the deep-sea hydrothermal vents of the Guaymas Basin, Gulf of California. Cell aggregates covering the surface of sulfide-emanating sediments and rock chimneys were collected by DS R/V Alvin and subjected to shipboard and laboratory experiments. Each sample collected contained one to three discrete width classes of this organism usually accompanied by a small number of flexibacteria (width, 1.5 to 4 {mu}m). The average widths of the Beggiatoa classes were 24 to 32, 40 to 42, and 116 to 122 {mu}m. As indicated by electron microscopy and cell volume/protein ratios, the dominant bacteria are hollow cells, i.e., a thin layer of cytoplasm surrounding a large central liquid vacuole. Activities of Calvin-cycle enzymes indicated that at least two of the classes collected possess autotrophic potential. Judging from temperature dependence of enzyme activities and whole-cell CO{sub 2} incorporation, the widest cells were mesophiles. The narrowest Beggiatoa sp. was either moderately thermophilic or mesophilic with unusually thermotolerant enzymes. This was consistent with its occurrence on the flanks of hot smoker chimneys with highly variable exit temperatures. In situ CO{sub 2} fixation rates, sulfide stimulation of incorporation, and autoradiographic studies suggest that these Beggiatoa spp. contribute significantly as lithoautrophic primary producers to the Guaymas Basin vent ecosystems.

  8. 33. BUILDING 1006, TYPICAL CEILING VENT REGISTER. Presidio of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    33. BUILDING 1006, TYPICAL CEILING VENT REGISTER. - Presidio of San Francisco, Letterman General Hospital, Building No. 27, Letterman Hospital Complex, Edie Road, San Francisco, San Francisco County, CA

  9. Scientists as stakeholders in conservation of hydrothermal vents.

    PubMed

    Godet, Laurent; Zelnio, Kevin A; VAN Dover, Cindy L

    2011-04-01

    Hydrothermal vents are deep-sea ecosystems that are almost exclusively known and explored by scientists rather than the general public. Continuing scientific discoveries arising from study of hydrothermal vents are concommitant with the increased number of scientific cruises visiting and sampling vent ecosystems. Through a bibliometric analysis, we assessed the scientific value of hydrothermal vents relative to two of the most well-studied marine ecosystems, coral reefs and seagrass beds. Scientific literature on hydrothermal vents is abundant, of high impact, international, and interdisciplinary and is comparable in these regards with literature on coral reefs and seagrass beds. Scientists may affect hydrothermal vents because their activities are intense and spatially and temporally concentrated in these small systems. The potential for undesirable effects from scientific enterprise motivated the creation of a code of conduct for environmentally and scientifically benign use of hydrothermal vents for research. We surveyed scientists worldwide engaged in deep-sea research and found that scientists were aware of the code of conduct and thought it was relevant to conservation, but they did not feel informed or confident about the respect other researchers have for the code. Although this code may serve as a reminder of scientists' environmental responsibilities, conservation of particular vents (e.g., closures to human activity, specific human management) may effectively ensure sustainable use of vent ecosystems for all stakeholders.

  10. Adding coal dust to coal batch

    SciTech Connect

    V.S. Shved; A.V.Berezin

    2009-05-15

    The granulometric composition of coke dust from the dry-slaking machine is determined. The influence of additions of 3-7% coke dust on the quality of industrial coking batch and the coke obtained by box coking is estimated. Adding 1% coke dust to coking batch does not markedly change the coke quality. Industrial equipment for the supply of dry-slaking dust to the batch is described.

  11. Plutonium immobilization feed batching system concept report

    SciTech Connect

    Erickson, S.

    2000-07-19

    The Plutonium Immobilization Facility will encapsulate plutonium in ceramic pucks and seal the pucks inside welded cans. Remote equipment will place these cans in magazines and the magazines in a Defense Waste Processing Facility (DWPF) canister. The DWPF will fill the canister with high level waste glass for permanent storage. Feed batching is one of the first process steps involved with first stage plutonium immobilization. It will blend plutonium oxide powder before it is combined with other materials to make pucks. This report discusses the Plutonium Immobilization feed batching process preliminary concept, batch splitting concepts, and includes a process block diagram, concept descriptions, a preliminary equipment list, and feed batching development areas.

  12. Thermodynamics of Protein Aggregation

    NASA Astrophysics Data System (ADS)

    Osborne, Kenneth L.; Barz, Bogdan; Bachmann, Michael; Strodel, Birgit

    Amyloid protein aggregation characterizes many neurodegenerative disorders, including Alzheimer's, Parkinson's, and Creutz- feldt-Jakob disease. Evidence suggests that amyloid aggregates may share similar aggregation pathways, implying simulation of full-length amyloid proteins is not necessary for understanding amyloid formation. In this study we simulate GNNQQNY, the N-terminal prion-determining domain of the yeast protein Sup35 to investigate the thermodynamics of structural transitions during aggregation. We use a coarse-grained model with replica-exchange molecular dynamics to investigate the association of 3-, 6-, and 12-chain GNNQQNY systems and we determine the aggregation pathway by studying aggregation states of GN- NQQNY. We find that the aggregation of the hydrophilic GNNQQNY sequence is mainly driven by H-bond formation, leading to the formation of /3-sheets from the very beginning of the assembly process. Condensation (aggregation) and ordering take place simultaneously, which is underpinned by the occurrence of a single heat capacity peak only.

  13. Response of key stress-related genes of the seagrass Posidonia oceanica in the vicinity of submarine volcanic vents

    NASA Astrophysics Data System (ADS)

    Lauritano, C.; Ruocco, M.; Dattolo, E.; Buia, M. C.; Silva, J.; Santos, R.; Olivé, I.; Costa, M. M.; Procaccini, G.

    2015-07-01

    Submarine volcanic vents are being used as natural laboratories to assess the effects of increased ocean acidity and carbon dioxide (CO2) concentration on marine organisms and communities. However, in the vicinity of volcanic vents other factors in addition to CO2, which is the main gaseous component of the emissions, may directly or indirectly confound the biota responses to high CO2. Here we used for the first time the expression of antioxidant and stress-related genes of the seagrass Posidonia oceanica to assess the stress levels of the species. Our hypothesis is that unknown factors are causing metabolic stress that may confound the putative effects attributed to CO2 enrichment only. We analyzed the expression of 35 antioxidant and stress-related genes of P. oceanica in the vicinity of submerged volcanic vents located in the islands of Ischia and Panarea, Italy, and compared them with those from control sites away from the influence of vents. Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was used to characterize gene expression patterns. Fifty-one percent of genes analyzed showed significant expression changes. Metal detoxification genes were mostly down-regulated in relation to controls at both Ischia and Panarea, indicating that P. oceanica does not increase the synthesis of heavy metal detoxification proteins in response to the environmental conditions present at the two vents. The up-regulation of genes involved in the free radical detoxification response (e.g., CAPX, SODCP and GR) indicates that, in contrast with Ischia, P. oceanica at the Panarea site faces stressors that result in the production of reactive oxygen species, triggering antioxidant responses. In addition, heat shock proteins were also activated at Panarea and not at Ischia. These proteins are activated to adjust stress-accumulated misfolded proteins and prevent their aggregation as a response to some stressors, not necessarily high temperature. This is the first

  14. Fluid dynamics in explosive volcanic vents and craters

    NASA Astrophysics Data System (ADS)

    Ogden, Darcy

    2011-12-01

    Explosive volcanic jets can transition to buoyant plumes or collapse to form pyroclastic density currents depending on their ability to entrain and heat the ambient air. Recent one-dimensional (1D) analysis shows that fluid acceleration through volcanic vents and craters changes the velocity and pressures within these jets sufficiently enough to be a first order control on plume dimensions and therefore air entrainment and column stability (Koyaguchi et al., 2010). These 1D studies are only applicable to craters and vents with angles of less than about 30° to vertical. Using analytical formulations and numerical simulations, this study describes 2D effects of shallowly dipping vents and craters on volcanic eruptions. The effect of vents on acceleration and expansion of eruptive mixtures of ash and gas is described as a force imparted on the fluid by the vent wall, the wall force ( Fw). This force is a measure of the momentum coupling between an eruption and the solid earth that takes place in the vent. Rapid divergence of supersonic eruptive fluid within shallowly dipping vents occurs via Prandtl-Meyer expansion, which results in different pressure and velocity fields than those predicted by 1D analysis. This expansion decreases Fw and the vertical acceleration experienced by the eruptive fluid in the vent. For jets predicted by 1D analysis to exit the vent at supersonic velocities and at atmospheric pressure, this decrease in Fw will cause an increase in the predicted plume area, decreasing column stability. The complex 2D shape of volcanic vents can change jet structure (presence and location of shock waves) and preclude the development of jets that exit the vent supersonically with no internal standing shock waves (i.e., perfectly expanded or pressure balanced jets). These significant complications in jet structure and increase in plume radius may result in changes to air entrainment, plume stability, and tephra distribution.

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

    NASA Astrophysics Data System (ADS)

    Ulrich, G. B.

    1994-06-01

    Iridium alloy clad vent sets (CVS's) are now being made by Energy Systems at the Oak Ridge Y-12 Plant. These CVS's 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 CVS'. Each CVS encapsulates one (238)PuO2 fuel pellet. The helium gas produced from the alpha decay of the (238)Pu 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&G-Mound Applied Technology, Inc. (EG&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&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&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%.

  16. Diffuse flow from hydrothermal vents. Doctoral thesis

    SciTech Connect

    Trivett, D.A.

    1991-08-01

    The effluent from a collection of diffuse hydrothermal vents was modelled to determine the fate of the source of flow under typical environmental conditions at seafloor spreading centers. A laboratory simulation was conducted to test an analytic model of diffuse plume rise. The results showed that diffuse plumes are likely to remain near the seafloor, with their maximum rise height scaled with the diameter of the source of diffuse flow. The entrainment of ambient seawater into these plumes is limited by the proximity to the seafloor, thus slowing the rate of dilution. The model of diffuse plume behaviour was used to guide the design and implementation of a scheme for monitoring the flow from diffuse hydrothermal vents in the ocean. A deployment of an array at the Southern Juan de Fuca Ridge yielded measurements of a variety of diffuse plume properties, including total heat output. Two distinct sources of hydrothermal flow were detected during the field deployment. The larger source was 1-1.5km north of the instrument array, and its energy output was 450 + or - 270MW. A smaller source was located 100m east of one instrument in the array. The energy output of the source was 12 + or - 8MW. The rise heights of the centerlines of these plumes were 45m and 10m, respectively.

  17. MAVEN Contamination Venting and Outgassing Analysis

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  18. 40 CFR Table 3 to Subpart Vvvvvv... - Emission Limits and Compliance Requirements for Continuous Process Vents

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... closed-vent system to a flare (except that a flare may not be used to control halogenated vent streams... therein i. As specified in § 63.11496(e). 2. Halogenated vent stream that is controlled through...

  19. On mean type aggregation.

    PubMed

    Yager, R R

    1996-01-01

    We introduce and define the concept of mean aggregation of a collection of n numbers. We point out that the lack of associativity of this operation compounds the problem of the extending mean of n numbers to n+1 numbers. The closely related concepts of self identity and the centering property are introduced as one imperative for extending mean aggregation operators. The problem of weighted mean aggregation is studied. A new concept of prioritized mean aggregation is then introduced. We next show that the technique of selecting an element based upon the performance of a random experiment can be considered as a mean aggregation operation.

  20. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Vaults: Sealing, venting, and ventilation. 192.187... Components § 192.187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed top pit... ventilating effect of a pipe 4 inches (102 millimeters) in diameter; (2) The ventilation must be enough...

  1. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Vaults: Sealing, venting, and ventilation. 192.187... Components § 192.187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed top pit... ventilating effect of a pipe 4 inches (102 millimeters) in diameter; (2) The ventilation must be enough...

  2. 40 CFR 63.983 - Closed vent systems.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 10 2010-07-01 2010-07-01 false Closed vent systems. 63.983 Section 63.983 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Emission Standards for Closed Vent Systems, Control Devices, Recovery Devices and Routing to a Fuel...

  3. 40 CFR 63.983 - Closed vent systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 10 2011-07-01 2011-07-01 false Closed vent systems. 63.983 Section 63.983 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED... Emission Standards for Closed Vent Systems, Control Devices, Recovery Devices and Routing to a Fuel...

  4. 40 CFR 65.143 - Closed vent systems.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 15 2011-07-01 2011-07-01 false Closed vent systems. 65.143 Section 65.143 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONSOLIDATED FEDERAL AIR RULE Closed Vent Systems, Control Devices, and Routing to a Fuel Gas System or...

  5. 49 CFR 192.187 - Vaults: Sealing, venting, and ventilation.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Vaults: Sealing, venting, and ventilation. 192.187... TRANSPORTATION OF NATURAL AND OTHER GAS BY PIPELINE: MINIMUM FEDERAL SAFETY STANDARDS Design of Pipeline Components § 192.187 Vaults: Sealing, venting, and ventilation. Each underground vault or closed top...

  6. Zero-G thermodynamic vent system for shuttle/Centaur

    NASA Technical Reports Server (NTRS)

    Niggemann, Richard E.

    1987-01-01

    Viewgraphs are presented showing drawings of Centaur configurations, the Thermodynamic Vent System (TVS), the mixer pump, and the hydrogen vent motor pump inverter. A cryogenic performance summary is given in chart form. The TVS liquid flow operation and vapor flow operation are diagrammed.

  7. Deep-sea primary production at the Galapagos hydrothermal vents

    SciTech Connect

    Karl, D.M.; Wirsen, C.O.; Jannasch, H.W.

    1980-03-21

    Dense animal populations surrounding recently discovered hydrothermal vents at the Galapagos Rift sea-floor spreading center, 2550 meters deep, are probably sustained by microbial primary production. Energy in the form of geothermically reduced sulfur compounds emitted from the vents is liberated during oxidation and used for the reduction of carbon dioxide to organic matter by chemosynthetic bacteria.

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

    PubMed

    Chown, Steven L

    2012-01-01

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

  9. 46 CFR 119.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Vent pipes for fuel tanks. 119.450 Section 119.450... Specific Machinery Requirements § 119.450 Vent pipes for fuel tanks. (a) Each unpressurized fuel tank must be fitted with a pipe connected to the highest point of the tank. (b) The minimum net cross...

  10. 46 CFR 119.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Vent pipes for fuel tanks. 119.450 Section 119.450... Specific Machinery Requirements § 119.450 Vent pipes for fuel tanks. (a) Each unpressurized fuel tank must be fitted with a pipe connected to the highest point of the tank. (b) The minimum net cross...

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

    NASA Astrophysics Data System (ADS)

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

    2013-11-01

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

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

    NASA Technical Reports Server (NTRS)

    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.

  13. 40 CFR 63.643 - Miscellaneous process vent provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Miscellaneous process vent provisions. (a) The owner or operator of a Group 1 miscellaneous process vent as defined in § 63.641 shall comply with the requirements of either paragraphs (a)(1) or (a)(2) of this section. (1) Reduce emissions of organic HAP's using a flare that meets the requirements of § 63.11(b)...

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

    NASA Technical Reports Server (NTRS)

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  16. 46 CFR 38.20-1 - Venting-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Venting-T/ALL. 38.20-1 Section 38.20-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-1 Venting—T/ALL. (a) Each safety relief valve installed on a cargo tank shall be connected to...

  17. 46 CFR 38.20-5 - Venting-T/ALL.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Venting-T/ALL. 38.20-5 Section 38.20-5 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS LIQUEFIED FLAMMABLE GASES Venting and Ventilation § 38.20-5 Venting—T/ALL. (a) Safety relief valves on cargo tanks in barges may be connected...

  18. Method and apparatus for melting glass batch

    DOEpatents

    Fassbender, Alexander G.; Walkup, Paul C.; Mudge, Lyle K.

    1988-01-01

    A glass melting system involving preheating, precalcining, and prefluxing of batch materials prior to injection into a glass furnace. The precursors are heated by convection rather than by radiation in present furnaces. Upon injection into the furnace, batch materials are intimately coated with molten flux so as to undergo or at least begin the process of dissolution reaction prior to entering the melt pool.

  19. Bathymodiolus growth dynamics in relation to environmental fluctuations in vent habitats

    NASA Astrophysics Data System (ADS)

    Nedoncelle, K.; Lartaud, F.; Contreira Pereira, L.; Yücel, M.; Thurnherr, A. M.; Mullineaux, L.; Le Bris, N.

    2015-12-01

    compared to long-term records of habitat temperature and oceanographic mooring data in the years following the eruption. Both shell growth and habitat temperature at V-vent varied over the spring-neap tidal cycle and over longer periods of c.a. 60 days. The correlation of growth rate with temperature and, for some individuals, with current velocities supports the idea that tidal forcing impacts growth. Its influence on habitat conditions includes the spring-neap cycle, which is not reflected in current velocities but influences the venting rate. Additionally, it is expected that mesoscale eddies periodically passing across the ridge imprint shell growth through the influence of bottom current on the decimeter-thick mixing interface where mussels thrive. We conclude that diurnal-semidiurnal tidal fluctuations exert major abiotic constraints on B. thermophilus mussels and that low-frequency fluctuations act as significant determinants on growth. Finally, we postulate that the modulation of tidal fluctuations by large-scale hydrodynamic forcing ultimately constrains the capacity of this mussel species to form high biomass aggregations. This study indeed shows that the absence of these strong hydrodynamic drivers would limit the alternance of oxic and sulfidic conditions and significantly affect the growth rate of this species over time.

  20. Staged venting of fuel cell system during rapid shutdown

    DOEpatents

    Clingerman, Bruce J.; Doan, Tien M.; Keskula, Donald H.

    2002-01-01

    A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

  1. Assessment of Literature Related to Combustion Appliance Venting Systems

    SciTech Connect

    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.

  2. Staged venting of fuel cell system during rapid shutdown

    DOEpatents

    Keskula, Donald H.; Doan, Tien M.; Clingerman, Bruce J.

    2004-09-14

    A venting methodology and system for rapid shutdown of a fuel cell apparatus of the type used in a vehicle propulsion system. H.sub.2 and air flows to the fuel cell stack are slowly bypassed to the combustor upon receipt of a rapid shutdown command. The bypass occurs over a period of time (for example one to five seconds) using conveniently-sized bypass valves. Upon receipt of the rapid shutdown command, the anode inlet of the fuel cell stack is instantaneously vented to a remote vent to remove all H.sub.2 from the stack. Airflow to the cathode inlet of the fuel cell stack gradually diminishes over the bypass period, and when the airflow bypass is complete the cathode inlet is also instantaneously vented to a remote vent to eliminate pressure differentials across the stack.

  3. Batch Scheduling a Fresh Approach

    NASA Technical Reports Server (NTRS)

    Cardo, Nicholas P.; Woodrow, Thomas (Technical Monitor)

    1994-01-01

    The Network Queueing System (NQS) was designed to schedule jobs based on limits within queues. As systems obtain more memory, the number of queues increased to take advantage of the added memory resource. The problem now becomes too many queues. Having a large number of queues provides users with the capability to gain an unfair advantage over other users by tailoring their job to fit in an empty queue. Additionally, the large number of queues becomes confusing to the user community. The High Speed Processors group at the Numerical Aerodynamics Simulation (NAS) Facility at NASA Ames Research Center developed a new approach to batch job scheduling. This new method reduces the number of queues required by eliminating the need for queues based on resource limits. The scheduler examines each request for necessary resources before initiating the job. Also additional user limits at the complex level were added to provide a fairness to all users. Additional tools which include user job reordering are under development to work with the new scheduler. This paper discusses the objectives, design and implementation results of this new scheduler

  4. Submarine radial vents on Mauna Loa Volcano, Hawai'i

    USGS Publications Warehouse

    Wanless, V. Dorsey; Garcia, M.O.; Trusdell, F.A.; Rhodes, J.M.; Norman, M.D.; Weis, Dominique; Fornari, D.J.; Kurz, M.D.; Guillou, Herve

    2006-01-01

    A 2002 multibeam sonar survey of Mauna Loa's western flank revealed ten submarine radial vents and three submarine lava flows. Only one submarine radial vent was known previously. The ages of these vents are constrained by eyewitness accounts, geologic relationships, Mn-Fe coatings, and geochemical stratigraphy; they range from 128 years B.P. to possibly 47 ka. Eight of the radial vents produced degassed lavas despite eruption in water depths sufficient to inhibit sulfur degassing. These vents formed truncated cones and short lava flows. Two vents produced undegassed lavas that created “irregular” cones and longer lava flows. Compositionally and isotopically, the submarine radial vent lavas are typical of Mauna Loa lavas, except two cones that erupted alkalic lavas. He-Sr isotopes for the radial vent lavas follow Mauna Loa's evolutionary trend. The compositional and isotopic heterogeneity of these lavas indicates most had distinct parental magmas. Bathymetry and acoustic backscatter results, along with photography and sampling during four JASON2 dives, are used to produce a detailed geologic map to evaluate Mauna Loa's submarine geologic history. The new map shows that the 1877 submarine eruption was much larger than previously thought, resulting in a 10% increase for recent volcanism. Furthermore, although alkalic lavas were found at two radial vents, there is no systematic increase in alkalinity among these or other Mauna Loa lavas as expected for a dying volcano. These results refute an interpretation that Mauna Loa's volcanism is waning. The submarine radial vents and flows cover 29 km2 of seafloor and comprise a total volume of ∼2×109 m3 of lava, reinforcing the idea that submarine lava eruptions are important in the growth of oceanic island volcanoes even after they emerged above sea level.

  5. 40 CFR 63.115 - Process vent provisions-methods and procedures for process vent group determination.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... vent stream is halogenated, the mass emission rate of halogen atoms contained in organic compounds shall be calculated. (A) The vent stream concentration of each organic compound containing halogen atoms... atoms: ER22AP94.204 where: E=mass of halogen atoms, dry basis, kilogram per hour. K2 = Constant,...

  6. Thermal Analysis of Waste Glass Batches: Effect of Batch Makeup on Gas-Evolving Reactions

    SciTech Connect

    Pierce, David A.; Hrma, Pavel R.; Marcial, Jose

    2013-01-21

    Batches made with a variety of precursors were subjected to thermo-gravimetric analysis. The baseline modifications included all-nitrate batch with sucrose addition, all-carbonate batch, and batches with different sources of alumina. All batches were formulated for a single glass composition (a vitrified simulated high-alumina high-level waste). Batch samples were heated from the ambient temperature to 1200°C at constant heating rates ranging from 1 K/min to 50 K/min. Major gas evolving reactions began at temperatures just above 100°C and were virtually complete by 650°C. Activation energies for major reactions were obtained with the Kissinger’s method. A rough model for the overall kinetics of the batch-conversion was developed to be eventually applied to a mathematical model of the cold cap.

  7. Deep-Sea Hydrothermal-Vent Sampler

    NASA Technical Reports Server (NTRS)

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

    2008-01-01

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

  8. Batch Proving and Proof Scripting in PVS

    NASA Technical Reports Server (NTRS)

    Munoz, Cesar A.

    2007-01-01

    The batch execution modes of PVS are powerful, but highly technical, features of the system that are mostly accessible to expert users. This paper presents a PVS tool, called ProofLite, that extends the theorem prover interface with a batch proving utility and a proof scripting notation. ProofLite enables a semi-literate proving style where specification and proof scripts reside in the same file. The goal of ProofLite is to provide batch proving and proof scripting capabilities to regular, non-expert, users of PVS.

  9. DETAIL VIEW OF BATCH CAR, BUILT BY ATLAS CAR & ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF BATCH CAR, BUILT BY ATLAS CAR & MANUFACTURING COMPANY. BATCH STORAGE SILOS IN BACKGROUND - Chambers Window Glass Company, Batch Plant, North of Drey (Nineteenth) Street, West of Constitution Boulevard, Arnold, Westmoreland County, PA

  10. Aggregate particles in the plumes of Enceladus

    NASA Astrophysics Data System (ADS)

    Gao, Peter; Kopparla, Pushkar; Zhang, Xi; Ingersoll, Andrew P.

    2016-01-01

    Estimates of the total particulate mass of the plumes of Enceladus are important to constrain theories of particle formation and transport at the surface and interior of the satellite. We revisit the calculations of Ingersoll and Ewald (Ingersoll, A.P., Ewald, S.P. [2011]. Icarus 216(2), 492-506), who estimated the particulate mass of the Enceladus plumes from strongly forward scattered light in Cassini ISS images. We model the plume as a combination of spherical particles and irregular aggregates resulting from the coagulation of spherical monomers, the latter of which allows for plumes of lower particulate mass. Though a continuum of solutions are permitted by the model, the best fits to the ISS data consist either of low mass plumes composed entirely of small aggregates or high mass plumes composed of mostly spheres. The high particulate mass plumes have total particulate masses of (166 ± 42) × 103 kg, consistent with the results of Ingersoll and Ewald (Ingersoll, A.P., Ewald, S.P. [2011]. Icarus 216(2), 492-506). The low particulate mass plumes have masses of (25 ± 4) × 103 kg, leading to a solid to vapor mass ratio of 0.07 ± 0.01 for the plume. If indeed the plumes are made of such aggregates, then a vapor-based origin for the plume particles cannot be ruled out. Finally, we show that the residence time of the monomers inside the plume vents is sufficiently long for Brownian coagulation to form the aggregates before they are ejected to space.

  11. Shipboard Aggregate Power Monitoring

    DTIC Science & Technology

    2009-06-01

    filters, valves , etc.) of a given system. Figure 1-1: Raw AC voltage and current measurements recorded during a motor start-up. (1) Figure...signal that opened a vent valve downstream of the exhaust fan for the propulsion turbine. Although the actuator signal is too small to see in the...low pressure air serves to operate various valves and provide pneumatic power for certain plant equipment. The compressor is an Ingersoll-Rand NAXI

  12. Biogeography of hydrothermal vent communities along seafloor spreading centers.

    PubMed

    Van Dover, C L

    1990-08-01

    Compared to terrestrial and shallow-water habitats, deep-sea hydrothermal vents are unique environments characterized by their local insularity, global distribution, individual ephemerality, collective geological longevity, geochemical homogeneity, and their physical and energetic isolation from the catastrophic events implicated in the extinction and speciation of terrestrial and shallow-water forms. Development of vent communities has thus occurred in novel biogeographical contexts that challenge our ability to understand evolutionary processes in the deep sea. Recent field work by French, Canadian, German, Japanese and American scientists has revealed intriguing patterns in the taxonomic composition and distribution of vent organisms at geographically disjunct study sites.

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

    NASA Astrophysics Data System (ADS)

    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

  14. Des Vents et des Jets Astrophysiques

    NASA Astrophysics Data System (ADS)

    Sauty, C.

    well expected result from the theory. Although, collimation may be conical, paraboloidal or cylindrical (Part 4), cylindrical collimation is the more likely to occur. The shape of outflows may then be used as a tool to predict physical conditions on the flows or on their source. L'éjection continue de plasma autour d'objets massifs est un phénomène largement répandu en astrophysique, que ce soit sous la forme du vent solaire, de vents stellaires, de jets d'étoiles en formation, de jets stellaires autour d'objets compacts ou de jets extra-galactiques. Cette zoologie diversifiée fait pourtant l'objet d'un commun effort de modélisation. Le but de cette revue est d'abord de présenter qualitativement le développement, depuis leur origine, des diverses théories de vents (Partie 1) et l'inter disciplinarité dans ce domaine. Il s'agit d'une énumération, plus ou moins exhaustive, des idées proposées pour expliquer l'accélération et la morphologie des vents et des jets, accompagnée d'une présentation sommaire des aspects observationnels. Cette partie s'abstient de tout aspect faisant appel au formalisme mathématique. Ces écoulements peuvent être décrits, au moins partiellement, en résolvant les équations magnétohydrodynamiques, axisymétriques et stationnaires. Ce formalisme, à la base de la plupart des théories, est exposé dans la Partie 2. Il permet d'introduire quantitativement les intégrales premières qu'un tel système possède. Ces dernières sont amenées à jouer un rôle important dans la compréhension des phénomènes d'accélération ou de collimation, en particulier le taux de perte de masse, le taux de perte de moment angulaire ou l'énergie du rotateur magnétique. La difficulté de modélisation réside dans l'existence de points critiques, propres aux équations non linéaires, qu'il faut franchir. La nature physique et la localisation de ces points critiques fait l'objet d'un débat important car ils sont la clef de voute de la r

  15. Intelligent real-time performance monitoring and quality prediction for batch/fed-batch cultivations.

    PubMed

    Undey, Cenk; Tatara, Eric; Cinar, Ali

    2004-02-19

    Supervision of batch bioprocess operations in real-time during the progress of a batch run offers many advantages over end-of-batch quality control. Multivariate statistical techniques such as multiway partial least squares (MPLS) provide an efficient modeling and supervision framework. A new type of MPLS modeling technique that is especially suitable for online real-time process monitoring and the multivariate monitoring charts are presented. This online process monitoring technique is also extended to include predictions of end-of-batch quality measurements during the progress of a batch run. Process monitoring, quality estimation and fault diagnosis activities are automated and supervised by embedding them into a real-time knowledge-based system (RTKBS). Interpretation of multivariate charts is also automated through a generic rule-base for efficient alarm handling. The integrated RTKBS and the implementation of MPLS-based process monitoring and quality control are illustrated using a fed-batch penicillin production benchmark process simulator.

  16. BatchQC: interactive software for evaluating sample and batch effects in genomic data.

    PubMed

    Manimaran, Solaiappan; Selby, Heather Marie; Okrah, Kwame; Ruberman, Claire; Leek, Jeffrey T; Quackenbush, John; Haibe-Kains, Benjamin; Bravo, Hector Corrada; Johnson, W Evan

    2016-12-15

    Sequencing and microarray samples often are collected or processed in multiple batches or at different times. This often produces technical biases that can lead to incorrect results in the downstream analysis. There are several existing batch adjustment tools for '-omics' data, but they do not indicate a priori whether adjustment needs to be conducted or how correction should be applied. We present a software pipeline, BatchQC, which addresses these issues using interactive visualizations and statistics that evaluate the impact of batch effects in a genomic dataset. BatchQC can also apply existing adjustment tools and allow users to evaluate their benefits interactively. We used the BatchQC pipeline on both simulated and real data to demonstrate the effectiveness of this software toolkit.

  17. Characterization of Aggregate Size in Taxus Suspension Cell Culture

    PubMed Central

    Kolewe, Martin E.; Henson, Michael A.; Roberts, Susan C.

    2015-01-01

    Plant cells grow as aggregates in suspension culture, but little is known about the dynamics of aggregation, and no routine methodology exists to measure aggregate size. In this study, we evaluate several different methods to characterize aggregate size in Taxus suspension cultures, in which aggregate diameters range from 50 μm to 2000 μm, including filtration and image analysis, and develop a novel method using a specially equipped Coulter counter system. We demonstrate the suitability of this technology to measure plant cell culture aggregates, and show that it can be reliably used to measure total biomass accumulation compared to standard methods such as dry weight. Furthermore, we demonstrate that all three methods can be used to measure an aggregate size distribution, but that the Coulter counter is more reliable and much faster, and also provides far better resolution. While absolute measurements of aggregate size differ based on the three evaluation techniques, we show that linear correlations are sufficient to account for these differences (R2 > 0.99). We then demonstrate the utility of the novel Coulter counter methodology by monitoring the dynamics of a batch process and find that the mean aggregate size increases by 55% during the exponential growth phase, but decreases during stationary phase. The results indicate that the Coulter counter method can be routinely used for advanced process characterization, particularly to study the relationship between aggregate size and secondary metabolite production, as well as a source of reliable experimental data for modeling aggregation dynamics in plant cell culture. PMID:20217417

  18. Aggregations in Flatworms.

    ERIC Educational Resources Information Center

    Liffen, C. L.; Hunter, M.

    1980-01-01

    Described is a school project to investigate aggregations in flatworms which may be influenced by light intensity, temperature, and some form of chemical stimulus released by already aggregating flatworms. Such investigations could be adopted to suit many educational levels of science laboratory activities. (DS)

  19. Unbonded Aggregate Surface Roads

    DTIC Science & Technology

    2006-12-01

    are sufficiently angular and rough in texture, thus ensuring mixture stability. A popular asphalt mixture design method called Superpave Level 1...would not pass either of the Superpave aggregate requirements. Table 18 Additional Characteristics for the Fine Fraction Abbreviated Common Name...CBR values when compacted wet of optimum. This is likely attributable to their relatively high permeabilities . For soaked CBR tests, the aggregates

  20. Erosion of dust aggregates

    NASA Astrophysics Data System (ADS)

    Seizinger, A.; Krijt, S.; Kley, W.

    2013-12-01

    Aims: The aim of this work is to gain a deeper insight into how much different aggregate types are affected by erosion. Especially, it is important to study the influence of the velocity of the impacting projectiles. We also want to provide models for dust growth in protoplanetary disks with simple recipes to account for erosion effects. Methods: To study the erosion of dust aggregates we employed a molecular dynamics approach that features a detailed micro-physical model of the interaction of spherical grains. For the first time, the model has been extended by introducing a new visco-elastic damping force, which requires a proper calibration. Afterwards, different sample generation methods were used to cover a wide range of aggregate types. Results: The visco-elastic damping force introduced in this work turns out to be crucial to reproduce results obtained from laboratory experiments. After proper calibration, we find that erosion occurs for impact velocities of 5 ms-1 and above. Though fractal aggregates as formed during the first growth phase are most susceptible to erosion, we observe erosion of aggregates with rather compact surfaces as well. Conclusions: We find that bombarding a larger target aggregate with small projectiles results in erosion for impact velocities as low as a few ms-1. More compact aggregates suffer less from erosion. With increasing projectile size the transition from accretion to erosion is shifted to higher velocities. This allows larger bodies to grow through high velocity collisions with smaller aggregates.

  1. 46 CFR 153.352 - B/3 and 4 m venting system outlets.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false B/3 and 4 m venting system outlets. 153.352 Section 153.352 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES... Cargo Venting Systems § 153.352 B/3 and 4 m venting system outlets. A B/3 or 4 m venting system...

  2. 46 CFR 153.352 - B/3 and 4 m venting system outlets.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false B/3 and 4 m venting system outlets. 153.352 Section 153.352 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CERTAIN BULK DANGEROUS CARGOES... Cargo Venting Systems § 153.352 B/3 and 4 m venting system outlets. A B/3 or 4 m venting system...

  3. 10. Launch control center vents, view towards west. Lyon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Launch control center vents, view towards west. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  4. 36. Launch Control Center, air vent above entrance. Lyon ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. Launch Control Center, air vent above entrance. Lyon - Whiteman Air Force Base, Oscar O-1 Minuteman Missile Alert Facility, Southeast corner of Twelfth & Vendenberg Avenues, Knob Noster, Johnson County, MO

  5. Detail of southeast side of Facility 283. Compare roof vents ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail of southeast side of Facility 283. Compare roof vents to those on Facility 226. - U.S. Naval Base, Pearl Harbor, Storehouse for Defense Battalion Type, Between Port Royal Street & Fuller Way, Pearl City, Honolulu County, HI

  6. 46 CFR 151.15-6 - Venting piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... LIQUID HAZARDOUS MATERIAL CARGOES Tanks § 151.15-6 Venting piping. (a) The back pressure in the relief valve discharge lines shall be taken into account when determining the flow capacity of the relief...

  7. 15. SANDSORTING BUILDING, SECOND FLOOR, VIEW OF DUST COLLECTION VENTS, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. SAND-SORTING BUILDING, SECOND FLOOR, VIEW OF DUST COLLECTION VENTS, LOOKING SOUTHWEST - Mill "C" Complex, Sand-Sorting Building, South of Dee Bennet Road, near Illinois River, Ottawa, La Salle County, IL

  8. DETAIL OF WEST END SLIDING DOOR AND EAVE VENTS ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF WEST END SLIDING DOOR AND EAVE VENTS ON THE SOUTH SIDE - Hickam Field, Practice Bomb Loading Shed, Bomb Storage Road near the intersection of Moffet and Kamakahi Streets, Honolulu, Honolulu County, HI

  9. Optical Detection of Organic Chemical Biosignatures at Hydrothermal Vents

    NASA Technical Reports Server (NTRS)

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

    2004-01-01

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

  10. 40 CFR 87.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... venting emissions shall be discharged into the atmosphere from any new or in-use aircraft gas turbine... the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and does...

  11. 40 CFR 87.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... fuel venting emissions shall be discharged into the atmosphere from any new or in-use aircraft gas... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...

  12. 14 CFR 34.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... fuel venting emissions shall be discharged into the atmosphere from any new or in-use aircraft gas... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...

  13. 40 CFR 87.11 - Standard for fuel venting emissions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... fuel venting emissions shall be discharged into the atmosphere from any new or in-use aircraft gas... discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down and...

  14. 46 CFR 119.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., or they must terminate in U-bends as high above the weather deck as practicable and as far as practicable from opening into any enclosed spaces. Vent pipes terminating on the hull exterior must...

  15. 46 CFR 182.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., or they must terminate in U-bends as high above the weather deck as practicable and as far as practicable from openings into any enclosed spaces. Vent pipes terminating on the hull exterior must...

  16. 46 CFR 119.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., or they must terminate in U-bends as high above the weather deck as practicable and as far as practicable from opening into any enclosed spaces. Vent pipes terminating on the hull exterior must...

  17. View of building 11070 showing vents and forced air system ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of building 11070 showing vents and forced air system on east side, looking southwest. - Naval Ordnance Test Station Inyokern, China Lake Pilot Plant, Maintenance Shop, C Street, China Lake, Kern County, CA

  18. 42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH VENTED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. VIEW EAST OF PLASTIC STACK (PROBABLY PVC) WHICH VENTED FUMES FROM THE DIPPING OPERATIONS IN BUILDING 49A; BUILDING 49 IS AT THE LEFT OF THE PHOTOGRAPH - Scovill Brass Works, 59 Mill Street, Waterbury, New Haven County, CT

  19. 14. SOUTHWEST CORNER OF BUILDING 28411 WITH MOBILE VENT TRUCK ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. SOUTHWEST CORNER OF BUILDING 28411 WITH MOBILE VENT TRUCK PLUGGED INTO SERVICE DUCTS (UPPER LEFT); VIEW TO NORTHEAST. - Cape Canaveral Air Station, Launch Complex 17, Facility 28501, East end of Lighthouse Road, Cape Canaveral, Brevard County, FL

  20. Building No. 902, detail of Mechanical Room door, including vent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Building No. 902, detail of Mechanical Room door, including vent and conduit - Presidio of San Francisco, Enlisted Men's Barracks Type, West end of Crissy Field, between Pearce & Maudlin Streets, San Francisco, San Francisco County, CA

  1. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  2. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  3. 40 CFR 63.1315 - Continuous process vents provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... requirements in § 63.1321. (d) Affected sources producing PET or polystyrene using a continuous process are..., select continuous process vents present at affected sources producing PET or polystyrene using...

  4. 40 CFR 63.1315 - Continuous process vents provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... requirements in § 63.1321. (d) Affected sources producing PET or polystyrene using a continuous process are..., select continuous process vents present at affected sources producing PET or polystyrene using...

  5. Looking North at Reactor Number One and Air Vent on ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Looking North at Reactor Number One and Air Vent on Fourth Floor of Oxide Building - Hematite Fuel Fabrication Facility, Oxide Building & Oxide Loading Dock, 3300 State Road P, Festus, Jefferson County, MO

  6. 7. Front of northern kiln group, looking north. Vents are ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Front of northern kiln group, looking north. Vents are visible in all kilns, in two rows above present grade. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  7. Vented Tank Resupply Experiment--Flight Test Results

    NASA Technical Reports Server (NTRS)

    Chato, David J.; Martin, Timothy A.

    1997-01-01

    This paper reports the results of the Vented Tank Resupply Experiment (VTRE) which was flown as a payload on STS 77. VTRE looks at the ability of vane Propellant Management Devices (PMD) to separate liquid and gas in low gravity. VTRE used two clear 0.8 cubic foot tanks one spherical and one with a short barrel section and transferred Refrigerant 113 between them as well as venting it to space. Tests included retention of liquid during transfer, liquid free venting, and recovery of liquid into the PMD after thruster firing. Liquid was retained successfully at the highest flow rate tested (2.73 gpm). Liquid free vents were achieved for both tanks, although at a higher flow rate (0.1591 cfm) for the spherical tank than the other (0.0400 cfm). Recovery from a thruster firing which moved the liquid to the opposite end of the tank from the PMD was achieved in 30 seconds.

  8. 22. STEEL ARCH SEGMENT AND VENT IN OFFICE, ROOM 2351, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. STEEL ARCH SEGMENT AND VENT IN OFFICE, ROOM 2351, SECOND FLOOR, NORTH SIDE. - Hughes Aircraft Company, Processing & Electronics Building, 6775 Centinela Avenue, Los Angeles, Los Angeles County, CA

  9. INTERIOR VIEW, DETAIL ORIGINAL VENTING AND WINDOW, FACING NORTHWEST. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, DETAIL ORIGINAL VENTING AND WINDOW, FACING NORTHWEST. - Southern Branch of the National Home for Disabled Volunteer Soldiers, Building 13, Harris Avenue at its intersection of Black Avenue and Woodfin Street, Hampton, Hampton, VA

  10. Potential biomass in deep-sea hydrothermal vent ecosystem

    NASA Astrophysics Data System (ADS)

    Nakamura, K.; Takai, K.

    2012-12-01

    Since the first discovery of black smoker vents hosting chemosynthetic macrofaunal communities (Spiess et al., 1980), submarine hydrothermal systems and associated biota have attracted interest of many researchers (e.g., Humphris et al., 1995; Van Dover, 2000; Wilcock et al., 2004). In the past couple of decades, particular attention has been paid to chemolithoautotrophic microorganisms that sustain the hydrothermal vent-endemic animal communities as the primary producer. This type of microorganisms obtains energy from inorganic substances (e.g., sulfur, hydrogen, and methane) derived from hydrothermal vent fluids, and is often considered as an important modern analogue to the early ecosystems of the Earth as well as the extraterrestrial life in other planets and moons (e.g., Jannasch and Mottl, 1985; Nealson et al., 2005; Takai et al., 2006). Even today, however, the size of this type of chemosynthetic deep-sea hydrothermal vent ecosystem is largely unknown. Here, we present geophysical and geochemical constraints on potential biomass in the deep-sea hydrothermal vent ecosystem. The estimation of the potential biomass in the deep-sea hydrothermal vent ecosystem is based on hydrothermal fluid flux calculated from heat flux (Elderfield and Schltz, 1996), maximum chemical energy available from metabolic reactions during mixing between hydrothermal vent fluids and seawater (McCollom, 2007), and maintenance energy requirements of the chemolithoautotrophic microorganisms (Hoehler, 2004). The result shows that the most of metabolic energy sustaining the deep-sea hydrothermal vent ecosystem is produced by oxidation reaction of reduced sulfur, although some parts of the energy are derived from hydrogenotrophic and methanotrophic reactions. The overall total of the potential biomass in deep-sea hydrothermal vent ecosystem is calculated to be much smaller than that in terrestrial ecosystems including terrestrial plants. The big difference in biomass between the

  11. 40 CFR Table 5 to Subpart Ppp of... - Process Vents From Batch Unit Operations-Monitoring, Recordkeeping, and Reporting Requirements

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... regeneration cycle(s), and 1. Record of total regeneration stream mass or volumetric flow for each carbon bed... carbon bed regeneration cycle during the performance test—NCS. c 3. Report all carbon bed regeneration... 15 minutes of completing any cooling cycle(s) 1. Record the temperature of the carbon bed after...

  12. 40 CFR 63.1325 - Batch process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    .... K=Constant, 2.494×10−6 (ppmv)−1 (gm-mole/scm) (kg/gm) (min/hr), where standard temperature is 20 °C. Cj=Average inlet or outlet concentration of TOC or sample organic HAP component j of the gas stream... component j of the gas stream, gm/gm-mole. AFR = Average inlet or outlet flow rate of gas stream for...

  13. 40 CFR Table 2 to Subpart Ffff of... - Emission Limits and Work Practice Standards for Batch Process Vents

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... to control organic HAP emissions a. Use a halogen reduction device after the combustion control device; or i. Reduce overall emissions of hydrogen halide and halogen HAP by ≥99 percent; orii. Reduce overall emissions of hydrogen halide and halogen HAP to ≤0.45 kg/hr; or iii. Reduce overall emissions...

  14. 40 CFR 63.1325 - Batch process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) or the emission limit specified in § 63.1322(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.1322(c)(1) or at the outlet of the halogen...

  15. 40 CFR 63.1325 - Batch process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) or the emission limit specified in § 63.1322(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.1322(c)(1) or at the outlet of the halogen...

  16. 40 CFR 63.490 - Batch front-end process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... specified in § 63.487(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.487(c)(1) or at the outlet of the halogen reduction device used to reduce...

  17. 40 CFR 63.490 - Batch front-end process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... specified in § 63.487(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.487(c)(1) or at the outlet of the halogen reduction device used to reduce...

  18. 40 CFR 63.490 - Batch front-end process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... specified in § 63.487(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.487(c)(1) or at the outlet of the halogen reduction device used to reduce...

  19. 40 CFR 63.490 - Batch front-end process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... specified in § 63.487(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.487(c)(1) or at the outlet of the halogen reduction device used to reduce...

  20. 40 CFR 63.1325 - Batch process vents-performance test methods and procedures to determine compliance.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) or the emission limit specified in § 63.1322(c)(2) for hydrogen halides and halogens. (1) Sampling sites shall be located at the inlet and outlet of the scrubber or other halogen reduction device used to reduce halogen emissions in complying with § 63.1322(c)(1) or at the outlet of the halogen...

  1. 40 CFR 63.488 - Methods and procedures for batch front-end process vent group determination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... temperature to which the vessel contents is heated is lower than 50 K below the boiling point of the HAP in... boiling point, then emissions from the heating of a vessel shall be calculated as the sum of the emissions... interval from the initial temperature to the temperature 50 K below the boiling point, emissions shall...

  2. 40 CFR 63.488 - Methods and procedures for batch front-end process vent group determination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... temperature to which the vessel contents is heated is lower than 50 K below the boiling point of the HAP in... boiling point, then emissions from the heating of a vessel shall be calculated as the sum of the emissions... interval from the initial temperature to the temperature 50 K below the boiling point, emissions shall...

  3. 40 CFR 63.488 - Methods and procedures for batch front-end process vent group determination.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... temperature to which the vessel contents is heated is lower than 50 K below the boiling point of the HAP in... boiling point, then emissions from the heating of a vessel shall be calculated as the sum of the emissions... interval from the initial temperature to the temperature 50 K below the boiling point, emissions shall...

  4. 40 CFR 63.488 - Methods and procedures for batch front-end process vent group determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... temperature to which the vessel contents is heated is lower than 50 K below the boiling point of the HAP in... boiling point, then emissions from the heating of a vessel shall be calculated as the sum of the emissions... interval from the initial temperature to the temperature 50 K below the boiling point, emissions shall...

  5. Explosion testing for the container venting system

    SciTech Connect

    Cashdollar, K.L.; Green, G.M.; Thomas, R.A.; Demiter, J.A.

    1993-09-30

    As part of the study of the hazards of inspecting nuclear waste stored at the Hanford Site, the US Department of Energy and Westinghouse Hanford Company have developed a container venting system to sample the gases that may be present in various metal drums and other containers. In support of this work, the US Bureau of Mines has studied the probability of ignition while drilling into drums and other containers that may contain flammable gas mixtures. The Westinghouse Hanford Company drilling procedure was simulated by tests conducted in the Bureau`s 8-liter chamber, using the same type of pneumatic drill that will be used at the Hanford Site. There were no ignitions of near-stoichiometric hydrogen-air or methane-air mixtures during the drilling tests. The temperatures of the drill bits and lids were measured by an infrared video camera during the drilling tests. These measured temperatures are significantly lower than the {approximately}500{degree}C autoignition temperature of uniformly heated hydrogen-air or the {approximately}600{degree}C autoignition temperature of uniformly heated methane-air. The temperatures are substantially lower than the 750{degree}C ignition temperature of hydrogen-air and 1,220{degree}C temperature of methane-air when heated by a 1-m-diameter wire.

  6. Antarctic Marine Biodiversity and Deep-Sea Hydrothermal Vents

    PubMed Central

    Chown, Steven L.

    2012-01-01

    The diversity of many marine benthic groups is unlike that of most other taxa. Rather than declining from the tropics to the poles, much of the benthos shows high diversity in the Southern Ocean. Moreover, many species are unique to the Antarctic region. Recent work has shown that this is also true of the communities of Antarctic deep-sea hydrothermal vents. Vent ecosystems have been documented from many sites across the globe, associated with the thermally and chemically variable habitats found around these, typically high temperature, streams that are rich in reduced compounds and polymetallic sulphides. The animal communities of the East Scotia Ridge vent ecosystems are very different to those elsewhere, though the microbiota, which form the basis of vent food webs, show less differentiation. Much of the biological significance of deep-sea hydrothermal vents lies in their biodiversity, the diverse biochemistry of their bacteria, the remarkable symbioses among many of the marine animals and these bacteria, and the prospects that investigations of these systems hold for understanding the conditions that may have led to the first appearance of life. The discovery of diverse and unusual Antarctic hydrothermal vent ecosystems provides opportunities for new understanding in these fields. Moreover, the Antarctic vents south of 60°S benefit from automatic conservation under the Convention on the Conservation of Antarctic Marine Living Resources and the Antarctic Treaty. Other deep-sea hydrothermal vents located in international waters are not protected and may be threatened by growing interests in deep-sea mining. PMID:22235192

  7. VentSim: a simulation model of cardiopulmonary physiology.

    PubMed

    Rutledge, G W

    1994-01-01

    VentSim is a quantitative model that predicts the effects of alternative ventilator settings on the cardiopulmonary physiology of critically ill patients. VentSim is an expanded version of the physiologic model in VentPlan, an application that provides ventilator-setting recommendations for patients in the intensive care unit. VentSim includes a ventilator component, an airway component, and a circulation component. The ventilator component predicts the pressures and airflows that are generated by a volume-cycled, constant-flow ventilator. The airway component has anatomic and physiologic deadspace compartments, and two alveolar compartments that participate in gas exchange with two pulmonary blood-flow compartments in the circulatory component. The circulatory component also has a shunt compartment that allows a fraction of blood flow to bypass gas exchange in the lungs, and a tissue compartment that consumes oxygen and generates carbon dioxide. The VentSim model is a set of linked first-order difference equations, with control variables that correspond to the ventilator settings, dependent variables that correspond to the physiologic state, and one independent variable, time. Because the model has no steady state solution, VentSim solves the equations by numeric integration, which is computation intensive. Simulation results demonstrate that VentSim predicts the effects of a variety of physiologic abnormalities that cannot be represented in less complex models such as the VentPlan model. For a ventilator-management application, the time-critical nature of ventilator-setting decisions limits the use of complex models. Advanced ventilator-management applications may include a mechanism to select patient-specific models that balance the trade-off of benefit of model detail and cost of computation delay.

  8. The stability of amino acids at submarine hydrothermal vent temperatures

    NASA Technical Reports Server (NTRS)

    Bada, Jeffrey L.; Miller, Stanley L.; Zhao, Meixun

    1995-01-01

    It has been postulated that amino acid stability at hydrothermal vent temperatures is controlled by a metastable thermodynamic equilibrium rather than by kinetics. Experiments reported here demonstrate that the amino acids are irreversibly destroyed by heating at 240 C and that quasi-equilibrium calculations give misleading descriptions of the experimental observations. Equilibrium thermodynamic calculations are not applicable to organic compounds under high-temperature submarine vent conditions.

  9. Gas generation results and venting study for transuranic waste drums

    SciTech Connect

    Kazanjian, A.R.; Arnold, P.M.; Simmons, W.C.; D'Amico, E.L.

    1985-09-23

    Sixteen waste drums, containing six categories of plutonium-contaminated waste, were monitored for venting and gas generation for six months. The venting devices tested appeared adequate to relieve pressure and prevent hydrogen accumulation. Most of the gas generation, primarily H2 and CO2, was due to radiolytic decomposition of the hydrogenous wastes. Comparison of the gas yields with those obtained previously in laboratory tests showed very reasonable agreement with few exceptions.

  10. Cryptic species of Archinome (Annelida: Amphinomida) from vents and seeps.

    PubMed

    Borda, Elizabeth; Kudenov, Jerry D; Chevaldonné, Pierre; Blake, James A; Desbruyères, Daniel; Fabri, Marie-Claire; Hourdez, Stéphane; Pleijel, Fredrik; Shank, Timothy M; Wilson, Nerida G; Schulze, Anja; Rouse, Greg W

    2013-11-07

    Since its description from the Galapagos Rift in the mid-1980s, Archinome rosacea has been recorded at hydrothermal vents in the Pacific, Atlantic and Indian Oceans. Only recently was a second species described from the Pacific Antarctic Ridge. We inferred the identities and evolutionary relationships of Archinome representatives sampled from across the hydrothermal vent range of the genus, which is now extended to cold methane seeps. Species delimitation using mitochondrial cytochrome c oxidase subunit I (COI) recovered up to six lineages, whereas concatenated datasets (COI, 16S, 28S and ITS1) supported only four or five of these as clades. Morphological approaches alone were inconclusive to verify the identities of species owing to the lack of discrete diagnostic characters. We recognize five Archinome species, with three that are new to science. The new species, designated based on molecular evidence alone, include: Archinome levinae n. sp., which occurs at both vents and seeps in the east Pacific, Archinome tethyana n. sp., which inhabits Atlantic vents and Archinome jasoni n. sp., also present in the Atlantic, and whose distribution extends to the Indian and southwest Pacific Oceans. Biogeographic connections between vents and seeps are highlighted, as are potential evolutionary links among populations from vent fields located in the east Pacific and Atlantic Oceans, and Atlantic and Indian Oceans; the latter presented for the first time.

  11. Design criteria and concepts for vented containment systems

    SciTech Connect

    Walling, H. C.; Benjamin, A. S.; Cybulskis, P.

    1980-01-01

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

  12. Payload bay atmospheric vent airflow testing at the Vibration and Acoustic Test Facility

    NASA Technical Reports Server (NTRS)

    Johnston, James D., Jr.

    1988-01-01

    Several concerns related to venting the Space Shuttle Orbiter payload bay during launch led to laboratory experiments with a flight-type vent box installed in the wall of a subsonic wind tunnel. This report describes the test setups and procedures used to acquire data for characterization of airflow through the vent box and acoustic tones radiated from the vent-box cavity. A flexible boundary-layer spoiler which reduced the vent-tone amplitude is described.

  13. Charged Dust Aggregate Interactions

    NASA Astrophysics Data System (ADS)

    Matthews, Lorin; Hyde, Truell

    2015-11-01

    A proper understanding of the behavior of dust particle aggregates immersed in a complex plasma first requires a knowledge of the basic properties of the system. Among the most important of these are the net electrostatic charge and higher multipole moments on the dust aggregate as well as the manner in which the aggregate interacts with the local electrostatic fields. The formation of elongated, fractal-like aggregates levitating in the sheath electric field of a weakly ionized RF generated plasma discharge has recently been observed experimentally. The resulting data has shown that as aggregates approach one another, they can both accelerate and rotate. At equilibrium, aggregates are observed to levitate with regular spacing, rotating about their long axis aligned parallel to the sheath electric field. Since gas drag tends to slow any such rotation, energy must be constantly fed into the system in order to sustain it. A numerical model designed to analyze this motion provides both the electrostatic charge and higher multipole moments of the aggregate while including the forces due to thermophoresis, neutral gas drag, and the ion wakefield. This model will be used to investigate the ambient conditions leading to the observed interactions. This research is funded by NSF Grant 1414523.

  14. Aggregate and the environment

    USGS Publications Warehouse

    Langer, William H.; Drew, Lawrence J.; Sachs, J.S.

    2004-01-01

    This book is designed to help you understand our aggregate resources-their importance, where they come from, how they are processed for our use, the environmental concerns related to their mining and processing, how those concerns are addressed, and the policies and regulations designed to safeguard workers, neighbors, and the environment from the negative impacts of aggregate mining. We hope this understanding will help prepare you to be involved in decisions that need to be made-individually and as a society-to be good stewards of our aggregate resources and our living planet.

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

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

  16. A Batch Feeder for Inhomogeneous Bulk Materials

    NASA Astrophysics Data System (ADS)

    Vislov, I. S.; Kladiev, S. N.; Slobodyan, S. M.; Bogdan, A. M.

    2016-04-01

    The work includes the mechanical analysis of mechanical feeders and batchers that find application in various technological processes and industrial fields. Feeders are usually classified according to their design features into two groups: conveyor-type feeders and non-conveyor feeders. Batchers are used to batch solid bulk materials. Less frequently, they are used for liquids. In terms of a batching method, they are divided into volumetric and weighting batchers. Weighting batchers do not provide for sufficient batching accuracy. Automatic weighting batchers include a mass controlling sensor and systems for automatic material feed and automatic mass discharge control. In terms of operating principle, batchers are divided into gravitational batchers and batchers with forced feed of material using conveyors and pumps. Improved consumption of raw materials, decreased loss of materials, ease of use in automatic control systems of industrial facilities allows increasing the quality of technological processes and improve labor conditions. The batch feeder suggested by the authors is a volumetric batcher that has no comparable counterparts among conveyor-type feeders and allows solving the problem of targeted feeding of bulk material batches increasing reliability and hermeticity of the device.

  17. [Repeated batch and fed-batch process for astaxanthin production by Phaffia rhodozyma].

    PubMed

    Xiao, Anfeng; Ni, Hui; Li, Lijun; Cai, Huinong

    2011-04-01

    A comparative study of batch and repeated batch process was carried out for astaxanthin fermentation of Phaffia rhodozyma to develop a more economical method for astaxanthin industrial production. In shaking flask fermentation, the change of biomass and astaxanthin production was studied to compare the five-day cycle with four-day cycle of repeated batch culture of P. rhodozyma. Astaxanthin production increased at first and then decreased subsequently in seven cycles, yet the yield of astaxanthin in the next six cycles remains higher than that of the first cycle. Comparing the average production of astaxanthin in the seven cycles, four-day cycle performed even better than five-day cycle. Subsequently, a repeated fed-batch process was used in a 5-1 bioreactor. The experimental data showed that biomass and astaxanthin production of the second batch could reach the level of the first batch, no matter that the carbon source was glucose or hydrolysis sugar of starch. This result showed that this strain had good stability, and thus repeated batch and fed-batch process could be applied in astaxanthin fermentation for economical purpose.

  18. Energy efficiency of batch and semi-batch (CCRO) reverse osmosis desalination.

    PubMed

    Warsinger, David M; Tow, Emily W; Nayar, Kishor G; Maswadeh, Laith A; Lienhard V, John H

    2016-12-01

    As reverse osmosis (RO) desalination capacity increases worldwide, the need to reduce its specific energy consumption becomes more urgent. In addition to the incremental changes attainable with improved components such as membranes and pumps, more significant reduction of energy consumption can be achieved through time-varying RO processes including semi-batch processes such as closed-circuit reverse osmosis (CCRO) and fully-batch processes that have not yet been commercialized or modelled in detail. In this study, numerical models of the energy consumption of batch RO (BRO), CCRO, and the standard continuous RO process are detailed. Two new energy-efficient configurations of batch RO are analyzed. Batch systems use significantly less energy than continuous RO over a wide range of recovery ratios and source water salinities. Relative to continuous RO, models predict that CCRO and batch RO demonstrate up to 37% and 64% energy savings, respectively, for brackish water desalination at high water recovery. For batch RO and CCRO, the primary reductions in energy use stem from atmospheric pressure brine discharge and reduced streamwise variation in driving pressure. Fully-batch systems further reduce energy consumption by not mixing streams of different concentrations, which CCRO does. These results demonstrate that time-varying processes can significantly raise RO energy efficiency.

  19. Kinetics of enzymatic hydrolysis of olive oil in batch and fed-batch systems.

    PubMed

    Cabral, Paloma Souza; Filho, Arion Zandoná; Voll, Fernando Augusto Pedersen; Corazza, Marcos Lúcio

    2014-07-01

    This work reports experimental data, kinetic modeling, and simulations of enzyme-catalyzed hydrolysis of olive oil. This reaction was performed in batch system and an ordered-sequential Bi Bi model was used to model the kinetic mechanism. A fed-batch system was proposed and experimental data were obtained and compared to the simulated values. The kinetic model used was able to correlate the experimental data, in which a satisfactory agreement between the experimental data and modeling results was obtained under different enzyme concentration and initial free water content. Therefore, the modeling allowed a better understanding of the reaction kinetics and affords a fed-batch simulation for this system. From the results obtained, it was observed that the fed-batch approach showed to be more advantageous when compared to the conventional batch system.

  20. Preliminary results on the reproduction of a deep-sea snailfish Careproctus rhodomelas around the active hydrothermal vent on the Hatoma Knoll, Okinawa, Japan.

    PubMed

    Takemura, A; Tamotsu, S; Miwa, T; Yamamoto, H

    2010-11-01

    Deep-sea snailfish Careproctus rhodomelas were collected from an active hydrothermal vent using a remotely operated vehicle (R.O.V. Hyper-dolphin) and a pressurized device (Deep-Aquarium). Careproctus rhodomelas exhibited a cystovarian-type ovary containing a small number of developing oocytes at different stages, suggesting that the fish is a batch-spawner that spawns large eggs (c. 6·0 mm) several times within its life span. In vitro culture of the oocytes in the presence of human chorionic gonadotropin showed that oestradiol-17β production fluctuated with oocyte development, suggesting that the oocytes were at the vitellogenic stage.

  1. Marine aggregate dynamics

    NASA Astrophysics Data System (ADS)

    The direction and scope of the Office of Naval Research's Marine Aggregate Dynamics Accelerated Research Initiative will be the topic of an open-house style meeting February 14, 7:30-10:00 P.M. in Ballroom D of the Hyatt Regency New Orleans at the Louisiana Superdome. This meeting is scheduled during the AGU/American Society of Limnology and Oceanography Ocean Sciences Meeting February 12-16 in New Orleans.The critical focus of the ARI is the measurement and modeling of the dynamics of the biological, physical, chemical and molecular processes that drive aggregation and produce aggregates. This new ARI will provide funding in Fiscal Years 1991-1995 to identify and quantify mechanisms that determine the distribution, abundance and size spectrum of aggregated particulate matter in the ocean.

  2. Protein Colloidal Aggregation Project

    NASA Technical Reports Server (NTRS)

    Oliva-Buisson, Yvette J. (Compiler)

    2014-01-01

    To investigate the pathways and kinetics of protein aggregation to allow accurate predictive modeling of the process and evaluation of potential inhibitors to prevalent diseases including cataract formation, chronic traumatic encephalopathy, Alzheimer's Disease, Parkinson's Disease and others.

  3. Aggregation and Averaging.

    ERIC Educational Resources Information Center

    Siegel, Irving H.

    The arithmetic processes of aggregation and averaging are basic to quantitative investigations of employment, unemployment, and related concepts. In explaining these concepts, this report stresses need for accuracy and consistency in measurements, and describes tools for analyzing alternative measures. (BH)

  4. Frozen Fractals All Around: Aggregate Particles in the Plumes of Enceladus

    NASA Astrophysics Data System (ADS)

    Gao, P.; Kopparla, P.; Zhang, X.; Ingersoll, A. P.

    2015-12-01

    Estimates of the total particulate mass of the plumes of Enceladus are important to constrain theories of particle formation and transport at the surface and interior of the satellite. We revisit the calculations of Ingersoll & Ewald (2011), who estimated the particulate mass of the Enceladus plumes from strongly forward scattered light in Cassini ISS images. We model the plume as a combination of spherical particles and irregular aggregates resulting from the coagulation of spherical monomers, the latter of which allows for plumes of lower particulate mass. Though a continuum of solutions are permitted by the model, the best fits to the ISS data consist either of low mass plumes composed entirely of small aggregates or high mass plumes composed of large aggregates and spheres. The high mass plumes can be divided into a population of large aggregates with total particulate mass of 116 ± 12 × 103 kg, and a mixed population of spheres and aggregates consisting of a few large monomers that has a total plume particulate mass of 166 ± 42 × 103 kg, consistent with the results of Ingersoll & Ewald (2011). Meanwhile, the low particulate mass aggregate plumes have masses of 25 ± 4 × 103 kg, leading to a solid to vapor mass ratio of 0.07 ± 0.01 for the plume. If indeed the plumes are made of such aggregates, then a vapor-based origin for the plume particles is possible. The process of aggregate formation by the coagulation of monomers, which depends on the bulk monomer number density inside the plume vents, requires a total plume vent cross sectional area of at most 1800 m2 to allow for the aggregates to form before the monomers are ejected into space. Differentiation between the high mass and low mass solutions may be possible if forward scattering observations are taken at scattering angles <2°, or else an independent plume particulate mass measurement becomes available.

  5. Detection of diffuse sea floor venting using structured light imaging

    NASA Astrophysics Data System (ADS)

    Inglis, G.; Smart, C.; Roman, C.; Carey, S.

    2011-12-01

    Efficiently identifying and localizing diffuse sea floor venting at hydrothermal and cold seep sites is often difficult. Actively venting fluids are usually identified by a temperature induced optical shimmering seen during direct visual inspections or in video data collected by vehicles working close to the sea floor. Relying on such direct methods complicates establishing spatial relations between areas within a survey covering a broad area. Our recent work with a structured light laser system has shown that venting can also be detected in the image data in an automated fashion. A structured light laser system consists of a camera and sheet laser projected at the sea floor. The camera and laser are fixed to a rigid calibrated mount such that the optical axis of the camera and the laser plane intersect at some distance away from the camera, typically 2 to 5 meters. The position of the laser line, visible on the sea floor in the image, can be extracted using standard computer vision techniques (Fig. 1) and used to determine the height of the bottom along the laser line. By collecting images in a survey pattern at a high frame rate, typically 20 to 30 Hz, a bathymetric map can be produced using the individual profiles. In the presence of venting, temperature anomalies refract the laser sheet such that it does not project a crisp and clear line on the sea floor. The laser will instead appear blurred and visible over a larger section of the image. By processing the images to segment out clear laser lines from refracted lines it is possible to identify areas of venting. Our initial approach uses calculated image moments relative to the peak intensity level detected in each column of the image matrix. In the presence of venting the calculated moments differ from those of the undistorted laser shining on the sea floor. Test results from the Kolumbo submarine volcano near Santorini, Greece demonstrate this approach and show the utility of the method for survey work. Test

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    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 combination with current measurements from lowered acoustic Doppler current profilers (LADCP) to calculate the horizontal plume fluxes of these gases. According to these examinations 0.02 μmol s-1 of 3He and 0.21 mol s-1 of methane are transported in a plume that flows into a southward direction in the central part of the valley. Based on 3He measurements of vent fluid (22 ± 6 pM), we estimate a total vent flux in this region of about 900 L s-1 and a total flux of CH4 of 3.2 mol s-1.

  7. A ubiquitous thermoacidophilic archaeon from deep-sea hydrothermal vents

    USGS Publications Warehouse

    Reysenbach, A.-L.; Liu, Yajing; Banta, A.B.; Beveridge, T.J.; Kirshtein, J.D.; Schouten, S.; Tivey, M.K.; Von Damm, Karen L.; Voytek, M.A.

    2006-01-01

    Deep-sea hydrothermal vents are important in global biogeochemical cycles, providing biological oases at the sea floor that are supported by the thermal and chemical flux from the Earth's interior. As hot, acidic and reduced hydrothermal fluids mix with cold, alkaline and oxygenated sea water, minerals precipitate to form porous sulphide-sulphate deposits. These structures provide microhabitats for a diversity of prokaryotes that exploit the geochemical and physical gradients in this dynamic ecosystem. It has been proposed that fluid pH in the actively venting sulphide structures is generally low (pH < 4.5), yet no extreme thermoacidophile has been isolated from vent deposits. Culture-independent surveys based on ribosomal RNA genes from deep-sea hydrothermal deposits have identified a widespread euryarchaeotal lineage, DHVE2 (deep-sea hydrothermal vent euryarchaeotic 2). Despite the ubiquity and apparent deep-sea endemism of DHVE2, cultivation of this group has been unsuccessful and thus its metabolism remains a mystery. Here we report the isolation and cultivation of a member of the DHVE2 group, which is an obligate thermoacidophilic sulphur- or iron-reducing heterotroph capable of growing from pH 3.3 to 5.8 and between 55 and 75??C. In addition, we demonstrate that this isolate constitutes up to 15% of the archaeal population, providing evidence that thermoacidophiles may be key players in the sulphur and iron cycling at deep-sea vents. ?? 2006 Nature Publishing Group.

  8. Steam chugging analysis in single-vent vapor injection

    NASA Technical Reports Server (NTRS)

    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.

  9. Instrumentation and measurement of airflow and temperature in attics fitted with ridge and soffit vents

    SciTech Connect

    Romero, M.I.; Brenner, R.J.

    1998-12-31

    This study established a research facility where airflow velocities, temperature, and differential pressures could be measured at the ridge of an attic. Following the construction of a test building, sensors were constructed, calibrated, and installed inside the attic. Paired tests were performed for three different ridge vent treatments; two were rolled type vents and one was a baffled vent. When both attics were fitted with the same ridge vent, the airspeed and differential pressure profiles at the ridge were very similar for both attics, indicating that any observed differences in airspeed and differential pressure were caused by the ridge vent treatment used. The baffled vent and rolled vents were then installed on the ridge of the west and east attics, respectively. The data demonstrated that the baffled ridge vent provided a minimum of twice the ridge airspeed of the rolled vents, when all wind conditions were considered. On the day selected to study the direction of the airflows at the ridge, the baffled vent had airflow speeds at the ridge similar to the rolled vent without fabric backing. The baffled vent allowed air to come out of the attic through both sides of the ridge (negative differential pressures on both sides), while the rolled vent without fabric backing caused air to enter through the south side of the ridge and exit through the north side (positive differential pressure on the south side and negative differential pressure on the north), in effect short-circuiting the vent. The fabric-backed rolled vent allowed attic air to come out of the attic through both sides of the ridge, as did the baffled vent, but the airspeed was slower. The baffled vent was the one with the highest airspeed at the ridge and also had both sides of the vent under negative differential pressure, providing the most effective ventilation.

  10. Fibronectin Aggregation and Assembly

    PubMed Central

    Ohashi, Tomoo; Erickson, Harold P.

    2011-01-01

    The mechanism of fibronectin (FN) assembly and the self-association sites are still unclear and contradictory, although the N-terminal 70-kDa region (I1–9) is commonly accepted as one of the assembly sites. We previously found that I1–9 binds to superfibronectin, which is an artificial FN aggregate induced by anastellin. In the present study, we found that I1–9 bound to the aggregate formed by anastellin and a small FN fragment, III1–2. An engineered disulfide bond in III2, which stabilizes folding, inhibited aggregation, but a disulfide bond in III1 did not. A gelatin precipitation assay showed that I1–9 did not interact with anastellin, III1, III2, III1–2, or several III1–2 mutants including III1–2KADA. (In contrast to previous studies, we found that the III1–2KADA mutant was identical in conformation to wild-type III1–2.) Because I1–9 only bound to the aggregate and the unfolding of III2 played a role in aggregation, we generated a III2 domain that was destabilized by deletion of the G strand. This mutant bound I1–9 as shown by the gelatin precipitation assay and fluorescence resonance energy transfer analysis, and it inhibited FN matrix assembly when added to cell culture. Next, we introduced disulfide mutations into full-length FN. Three disulfide locks in III2, III3, and III11 were required to dramatically reduce anastellin-induced aggregation. When we tested the disulfide mutants in cell culture, only the disulfide bond in III2 reduced the FN matrix. These results suggest that the unfolding of III2 is one of the key factors for FN aggregation and assembly. PMID:21949131

  11. Production of nattokinase by batch and fed-batch culture of Bacillus subtilis.

    PubMed

    Cho, Young-Han; Song, Jae Yong; Kim, Kyung Mi; Kim, Mi Kyoung; Lee, In Young; Kim, Sang Bum; Kim, Hyeon Shup; Han, Nam Soo; Lee, Bong Hee; Kim, Beom Soo

    2010-09-30

    Nattokinase was produced by batch and fed-batch culture of Bacillus subtilis in flask and fermentor. Effect of supplementing complex media (peptone, yeast extract, or tryptone) was investigated on the production of nattokinase. In flask culture, the highest cell growth and nattokinase activity were obtained with 50 g/L of peptone supplementation. In this condition, nattokinase activity was 630 unit/ml at 12 h. In batch culture of B. subtilis in fermentor, the highest nattokinase activity of 3400 unit/ml was obtained at 10h with 50 g/L of peptone supplementation. From the batch kinetics data, it was shown that nattokinase production was growth-associated and culture should be harvested before stationary phase for maximum nattokinase production. In fed-batch culture of B. subtilis using pH-stat feeding strategy, cell growth (optical density monitored at 600 nm) increased to ca. 100 at 22 h, which was 2.5 times higher than that in batch culture. The highest nattokinase activity was 7100 unit/ml at 19 h, which was also 2.1 times higher than that in batch culture.

  12. JOB BUILDER remote batch processing subsystem

    NASA Technical Reports Server (NTRS)

    Orlov, I. G.; Orlova, T. L.

    1980-01-01

    The functions of the JOB BUILDER remote batch processing subsystem are described. Instructions are given for using it as a component of a display system developed by personnel of the System Programming Laboratory, Institute of Space Research, USSR Academy of Sciences.

  13. Batch testing for noroviruses in frozen raspberries.

    PubMed

    De Keuckelaere, Ann; Li, Dan; Deliens, Bart; Stals, Ambroos; Uyttendaele, Mieke

    2015-01-02

    Berries, in particular raspberries, have been associated with multiple recalls due to norovirus contamination and were linked to a number of norovirus (NoV) outbreaks. In the present study a total of 130 samples of frozen raspberries were collected from 26 batches in four different raspberry processing companies. In two companies the samples consisted of bulk frozen raspberries serving as raw material for the production of raspberry puree (an intermediate food product in a business to business setting). In two other companies, the samples consisted of bulk individually quick frozen (IQF) raspberries serving as raw material for the production of frozen fruit mixes (as a final food product for consumer). Enumeration of Escherichia coli and coliforms was performed as well as real-time reverse transcription PCR (RT-qPCR) detection of GI and GII NoV (in 2 × 10 g). In addition, in cases where positive NoV GI or GII RT-qPCR signals were obtained, an attempt to sequence the amplicons was undertaken. Six out of 70 samples taken from the 14 batches of frozen raspberries serving raspberry puree production provided a NoV RT-qPCR signal confirmed by sequencing. Four of these six positive samples clustered in one batch whereas the other two positive samples clustered in another batch from the same company. All six positive samples showed NoV RT-qPCR signals above the limit of quantification of the RT-qPCR assay. These two positive batches of frozen raspberries can be classified as being of insufficient sanitary quality. The mean NoV level in 20 g of these raspberry samples was 4.3 log genomic copies NoV GI/20 g. The concern for public health is uncertain as NoV RT-qPCR detection is unable to discriminate between infectious and non-infectious virus particles. For the IQF raspberries, one batch out of 12 tested NoV positive, but only 1 out of the 5 samples analyzed in this batch showed a positive RT-qPCR GI NoV signal confirmed by sequencing. The RT-qPCR signal was below the

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

    NASA Astrophysics Data System (ADS)

    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

  15. The Prevention of Ice Formation on Gasoline Tank Vents

    NASA Technical Reports Server (NTRS)

    Theodorsen, Theodore; Clay, William C

    1931-01-01

    This investigation was conducted in the refrigerated wind tunnel at the Langley Memorial Aeronautical Laboratory, Langley Field, Va., to determine a suitable method for preventing the formation of ice on the vents of airplane gasoline tanks. Tests were made on a variety of vent forms arranged in a number of different orientations relative to the direction of the air stream. Both the size of the tube and its orientation were found to be of great importance. Small tubes, under equal circumstances, were found to freeze over far more rapidly than large ones. Tubes pointing downstream, or shielded in other ways, appear to be perfectly immune against this hazard. A tube 3/4 inch in diameter with the opening pointing downstream is finally recommended as being the safest choice of gas tank vent.

  16. Bus Vent Design Evolution for the Solar Dynamics Observatory

    NASA Technical Reports Server (NTRS)

    Woronowicz, Michael

    2010-01-01

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

  17. Science Requirements for Limits on Vent Tube Stray Light

    NASA Astrophysics Data System (ADS)

    Petro, L.

    2007-12-01

    The design of the WFC3 UVIS and IR detector vent tubes is intended to assure that the stray light on the science detectors from illumination by the bright Earth at the vent tube radiator openings is greatly attenuated. The limits on that stray light and the nominal attenuation required in order that the scientific quality of images is not significantly degraded are presented here. The stray light signal rate in the UVIS detector should be less than 5.0 electrons/sec/cm2, and less than 75 electrons/sec/cm2 for the IR detector. In order to meet these limits, the incident flux of the bright Earth on the vent tube opening must be attenuated at the detector by greater than 2×10^16 in the UVIS channel and 3-10^15 in the IR channel.

  18. Post-drilling hydrothermal vent and associated biological activities seen through artificial hydrothermal vents in the Iheya North field, Okinawa Trough

    NASA Astrophysics Data System (ADS)

    Takai, K.; Kawagucci, S.; Miyazaki, J.; Watsuji, T.; Ishibashi, J.; Yamamoto, H.; Nozaki, T.; Kashiwabara, T.; Shibuya, T.

    2012-12-01

    In 2010, IODP Expedition 331 was conducted in the Iheya North Field, the Okinawa Trough and drilled several sites in hydrothermally active subseafloor. In addition, during the IODP Expedition 331, four new hydrothermal vents were created. These post-drilling artificial hydrothermal vents provide excellent opportunities to investigate the physical, chemical and microbiological characteristics of the previously unexplored subseafloor hydrothermal fluid reservoirs, and to monitor and estimate how the anthropogenic drilling behaviors affect the deep-sea hydrothermal vent ecosystem. We were very much interested in the difference of hydrothermal fluid chemistry between the natural hydrothermal vents and the artificial hydrothermal vents. The IODP porewater chemistry of the cores pointed to the density-driven stratification of the phase-separated hydrothermal fluids and the natural vent fluids were likely derived only from the shallower vapor-enriched phases. However, the artificial hydrothermal vents had deeper fluid sources in the subseafloor hydrothermal fluid reservoirs composed of vapor-lost (Cl-enriched) phases. The fluids from the artificial hydrothermal vents were sampled by ROV at 5, 12 and 18 months after the IODP expedition. The artificial hydrothermal vent fluids were slightly enriched with Cl as compared to the natural hydrothermal vent fluids. Thus, the artificial hydrothermal vents successfully entrained the previously unexplored subseafloor hydrothermal fluids. The newly created hydrothermal vents also hosted the very quickly grown, enormous chimney structures, of which mineral compositions were highly variable among the vents. However, the quickly grown C0016B and C0016D vent chimneys were found to be typical Kuroko ore even though the chimney growth rates in the artificial vents were extremely faster than those in the natural vents. In addition, the IODP drilling operation not only created new hydrothermal vents by deep drilling but also induced the

  19. Hydrothermal Fluxes at the Turtle Pits Vent Site, southern MAR

    NASA Astrophysics Data System (ADS)

    Köhler, J.; Walter, M.; Mertens, C.; Sültenfuß, J.; Rhein, M.

    2009-04-01

    The Turtle Pits vent fields are located in a north-south orientated rift valley at the Mid-Atlantic Ridge (MAR) near 5oS. The site consists of three known hydrothermal fields: Turtle Pits, Comfortless Cove, and Red Lion. Data collected during a Meteor cruise in May 2006 and a L' Atalante cruise in January 2008 are used to calculate the total emission of volume, heat, and helium of the site. The data sets consist of vertical profiles and towed transsects of temperature, salinity, and turbidity, as well as direct velocity measurements with a lowered acoustic Doppler current profiler (LADCP) and water samples for Helium isotope analysis. Vent fluid samples for noble gas analysis where taken with an ROV. The particle plume is confined to the rift valley since the depth of the valley exceeds the rise height of the plume. Therefore the fluxes of heat and volume can be estimated from the helium fluxes at the vent sites in comparison with the horizontal helium transport in the valley. The comparison of the 3He concentration measured south of the hydrothermal vents with the 3He signal north of the hydrothermal vents suggests a rather strong northward flow. This is confirmed by the tide corrected velocities observed with the LADCP during the Meteor cruise. The northward volume transport has been calculated using the local bathymetry and tide corrected velocities from the Meteor cruise. In combination with the 3He concentrations and an average 3He end member concentration a flux of 900 l/s is estimated, which corresponds to a heat flux of 450 MW. The rise height of the particle plume estimated from the turbidity data combined with the known background stratification yields an estimate of the total flux of the hydrothermal vents which is one order of magnitude lower.

  20. Hydrothermal vents of Yellowstone Lake, Yellowstone National Park, Wyoming

    SciTech Connect

    Kaplinski, M.A.; Morgan, P. . Geology Dept.)

    1993-04-01

    Hydrothermal vent systems within Yellowstone Lake are located within the Yellowstone caldera in the northeastern and West Thumb sections of the lake. The vent systems lie within areas of extremely high geothermal gradients (< 1,000 C/km) in the lake sediments and occur as clusters of individual vents that expel both hydrothermal fluids and gas. Regions surrounding the vents are colonized by unique, chemotropic biologic communities and suggest that hydrothermal input plays an important role in the nutrient dynamics of the lake's ecosystem. The main concentration of hydrothermal activity occurs in the northeast region of the main lake body in a number of locations including: (1) along the shoreline from the southern edge of Sedge Bay to the inlet of Pelican Creek; (2) the central portion of the partially submerged Mary Bay phreatic explosion crater, within deep (30--50 m) fissures; (3) along the top of a 3 km long, steep-sided ridge that extends from the southern border of Mary Bay, south-southeast into the main lake basin; and (4) east of Stevenson Island along the lower portion of the slope (50--107 m) into the lake basin, within an anastomosing series of north to northwest trending, narrow troughs or fissures. Hydrothermal vents were also located within, and surrounding the West Thumb of Yellowstone Lake, with the main concentration occurring the offshore of the West Thumb and Potts Geyser Basin. Hydrothermal vents in Yellowstone Lake occur along fractures that have penetrated the lake sediments or along the tops of ridges and near shore areas. Underneath the lake, rising hydrothermal fluids encounter a semi-permeable cap of lake sediments. Upwardly convecting hydrothermal fluid flow may be diverted by the impermeable lake sediments along the buried, pre-existing topography. These fluids may continue to rise along topography until fractures are encountered, or the lake sediment cover is thinned sufficiently to allow egress of the fluids.

  1. A vented inverted fuel assembly design for an SFR

    SciTech Connect

    Vitillo, F.; Todreas, N. E.; Driscoll, M. J.

    2012-07-01

    The inverted geometry (fuel outside coolant tubes) has been previously investigated at MIT for application in gas-cooled fast reactors and pressurized water-cooled thermal reactors. Venting has also been studied for conventional fuel pins and was employed for those in the Dounreay Fast Reactor. In the present work the inverted fuel approach was adopted because it allows high fuel volume fraction, reduction of the coolant void reactivity, neutron leakage and enrichment, as well as lower pressure drop for the same channel length because grids and wire wraps are no longer necessary. Furthermore most results also apply to venting of conventional fuel pins. Physical and chemical behavior of volatile fission products in sodium was investigated to determine the maximum activity inventory which would eventually be released into the primary sodium. Results of this analysis show that the most troublesome radionuclides in terms of propensity to escape from the venting system are noble gases ({sup 85}Kr and {sup 133}Xe), and cesium ({sup 134}Cs and {sup 137}Cs). A final vented inverted fuel assembly design is proposed which meets all the design goals which have been set. Additionally purification systems were devised to reduce radionuclide activity of the coolant and the cover gas to tolerable levels. It is concluded that vented inverted (or vented conventional pin) fuel is a feasible concept and has sufficiently promising advantages - increasing fuel volume fraction to 50% and core outlet temperature by 20 deg. C, hence incrementing plant thermal efficiency by about 1% - to warrant serious consideration for future SFR designs. (authors)

  2. Zero Gravity Cryogenic Vent System Concepts for Upper Stages

    NASA Technical Reports Server (NTRS)

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

    1999-01-01

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

  3. Contamination of the space station environment by vented chemicals

    NASA Technical Reports Server (NTRS)

    Bernhardt, Paul A.

    1988-01-01

    Gaseous materials vented from materials and life science experiments on the Space Station may have noticeable effects on the optical or plasma environment. The magnitude of the effects depends on: (1) rarefied gas dynamics; (2) photochemical reactions; and (3) airglow excitation mechanisms. In general, the effects from atomic species can be mitigated, but the disturbances resulting from venting of molecules like SF6, CO2 and C2H2 can be significant. The interaction of molecules with ambient plasma at orbital velocities should be studied with laboratory or space experiments.

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

    USGS Publications Warehouse

    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

  5. Pressure Venting Tests of Phenolic Impregnated Carbon Ablator (PICA)

    NASA Technical Reports Server (NTRS)

    Blosser, Max L.; Knutson, Jeffrey R.

    2015-01-01

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

  6. Technology meets aggregate

    SciTech Connect

    Wilson, C.; Swan, C.

    2007-07-01

    New technology carried out at Tufts University and the University of Massachusetts on synthetic lightweight aggregate has created material from various qualities of fly ash from coal-fired power plants for use in different engineered applications. In pilot scale manufacturing tests an 'SLA' containing 80% fly ash and 20% mixed plastic waste from packaging was produced by 'dry blending' mixed plastic with high carbon fly ash. A trial run was completed to produce concrete masonry unit (CMU) blocks at a full-scale facility. It has been shown that SLA can be used as a partial substitution of a traditional stone aggregate in hot asphalt mix. 1 fig., 2 photos.

  7. Production of fructosyltransferase by Aureobasidium sp. ATCC 20524 in batch and two-step batch cultures.

    PubMed

    Salinas, Martín A; Perotti, Nora I

    2009-01-01

    A comparison of fructosyltransferase (EC 2.4.1.9) production by Aureobasidium sp. ATCC 20524 in batch and two step batch cultures was investigated in a 1-l stirred tank reactor using a sucrose supply of 200 g/l. Results showed that the innovative cultivation in two step of Aureobasidium sp. produced more fructosyltransferase (FFase) than the single batch culture at the same sucrose concentration with a maximal enzyme production of 523 U/ml, which was 80.5% higher than the one obtained in the batch culture. The production of fructooligosaccharides (FOSs) was also analyzed; their concentration reached a maximum value of 160 g/l the first day in the two-step culture and 127 g/l in the single-batch mode. The use of the two-step batch culture with Aureobasidium sp. ATCC 20524 in allowing the microorganism to grow up prior to the induction of sucrose (second step), proved to be a powerful method for producing fructosyltransferase and FOSs.

  8. Batch and fed-batch fermentation of Bacillus thuringiensis using starch industry wastewater as fermentation substrate.

    PubMed

    Vu, Khanh Dang; Tyagi, Rajeshwar Dayal; Valéro, José R; Surampalli, Rao Y

    2010-08-01

    Bacillus thuringiensis var. kurstaki biopesticide was produced in batch and fed-batch fermentation modes using starch industry wastewater as sole substrate. Fed-batch fermentation with two intermittent feeds (at 10 and 20 h) during the fermentation of 72 h gave the maximum delta-endotoxin concentration (1,672.6 mg/L) and entomotoxicity (Tx) (18.5 x 10(6) SBU/mL) in fermented broth which were significantly higher than maximum delta-endotoxin concentration (511.0 mg/L) and Tx (15.8 x 10(6) SBU/mL) obtained in batch process. However, fed-batch fermentation with three intermittent feeds (at 10, 20 and 34 h) of the fermentation resulted in the formation of asporogenous variant (Spo-) from 36 h to the end of fermentation (72 h) which resulted in a significant decrease in spore and delta-endotoxin concentration and finally the Tx value. Tx of suspended pellets (27.4 x 10(6) SBU/mL) obtained in fed-batch fermentation with two feeds was the highest value as compared to other cases.

  9. An overview of BWR Mark-I containment venting risk implications

    SciTech Connect

    Wagner, K.C.; Dallman, R.J.; Galyean, W.J.

    1988-11-01

    Venting of boiling water reactors with Mark-I containments has been suggested as a way to prevent catastrophic failure and/or mitigate the consequences resulting from a severe accident. Based on phenomenological, human factors, and risk considerations, the potential benefits and downsides of venting Mark-I containments were analyzed. Several generic venting systems and two proposed utility systems were reviewed. Based on generic considerations, the offsite consequences during risk dominant accidents were qualitatively assessed for four different vent systems. A quantitative risk study of an early venting strategy was performed, based on the existing Peach Bottom hardware and the draft NUREG-1150 results for Peach Bottom. Appendices are also included which contain reviews of the Pilgrim and Vermont Yankee venting submitals, a response to the seven questions from the NRC about the Pilgrim venting strategy, and a review of the venting strategy directed by Revision 4 of the Boiling Water Reactor Emergency Procedures Guidelines. 16 refs., 7 figs., 7 tabs.

  10. Special automation and regulation strategies for enhancing sequencing batch reactor (SBR) performances.

    PubMed

    Rönner-Holm, S G E; Holm, N C

    2009-01-01

    Dynamic simulation analyses of five different sequencing batch reactor (SBR) wastewater treatment plants (WWTPs) were used in order to optimise developed regulation strategies and to develop new strategies. The results were applied directly to 15 full-scale SBR plants. To do this, the cycle strategies were extended through the use of appropriate aggregates, or were anchored in the programmable logic controller (PLC) and process control system (PCS) with the help of online sensors. This enabled all regulation strategies to be introduced and automated without problems.

  11. Aggregates, broccoli and cauliflower

    NASA Astrophysics Data System (ADS)

    Grey, Francois; Kjems, Jørgen K.

    1989-09-01

    Naturally grown structures with fractal characters like broccoli and cauliflower are discussed and compared with DLA-type aggregates. It is suggested that the branching density can be used to characterize the growth process and an experimental method to determine this parameter is proposed.

  12. 3. INSIDE BATCH FURNACE BUILDING, VIEW LOOKING NORTH AT REGENERATIVE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. INSIDE BATCH FURNACE BUILDING, VIEW LOOKING NORTH AT REGENERATIVE BATCH FURNACES ON LEFT AND 5 TON CAPACITY CHARGING MACHINE ON RIGHT. - U.S. Steel Duquesne Works, 22-Inch Bar Mill, Along Monongahela River, Duquesne, Allegheny County, PA

  13. Using Forensics to Untangle Batch Effects in TCGA Data - TCGA

    Cancer.gov

    Rehan Akbani, Ph.D., and colleagues at the University of Texas MD Anderson Cancer Center developed a tool called MBatch to detect, diagnose, and correct batch effects in TCGA data. Read more about batch effects in this Case Study.

  14. Job Scheduling Under the Portable Batch System

    NASA Technical Reports Server (NTRS)

    Henderson, Robert L.; Woodrow, Thomas S. (Technical Monitor)

    1995-01-01

    The typical batch queuing system schedules jobs for execution by a set of queue controls. The controls determine from which queues jobs may be selected. Within the queue, jobs are ordered first-in, first-run. This limits the set of scheduling policies available to a site. The Portable Batch System removes this limitation by providing an external scheduling module. This separate program has full knowledge of the available queued jobs, running jobs, and system resource usage. Sites are able to implement any policy expressible in one of several procedural language. Policies may range from "bet fit" to "fair share" to purely political. Scheduling decisions can be made over the full set of jobs regardless of queue or order. The scheduling policy can be changed to fit a wide variety of computing environments and scheduling goals. This is demonstrated by the use of PBS on an IBM SP-2 system at NASA Ames.

  15. Capacitated max -Batching with Interval Graph Compatibilities

    NASA Astrophysics Data System (ADS)

    Nonner, Tim

    We consider the problem of partitioning interval graphs into cliques of bounded size. Each interval has a weight, and the weight of a clique is the maximum weight of any interval in the clique. This natural graph problem can be interpreted as a batch scheduling problem. Solving a long-standing open problem, we show NP-hardness, even if the bound on the clique sizes is constant. Moreover, we give a PTAS based on a novel dynamic programming technique for this case.

  16. PBF Cooling Tower. View of stairway to fan deck. Vents ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PBF Cooling Tower. View of stairway to fan deck. Vents are made of redwood. Camera facing southwest toward north side of Cooling Tower. Siding is corrugated asbestos concrete. Photographer: Kirsh. Date: June 6, 1969. INEEL negative no. 69-3463 - Idaho National Engineering Laboratory, SPERT-I & Power Burst Facility Area, Scoville, Butte County, ID

  17. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous wastes... engineering calculations or performance tests. If performance tests are used to determine vent emissions... performance tests must conform with the requirements of § 265.1034(c). (d) When an owner or operator and...

  18. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous wastes... engineering calculations or performance tests. If performance tests are used to determine vent emissions... performance tests must conform with the requirements of § 265.1034(c). (d) When an owner or operator and...

  19. 40 CFR 265.1032 - Standards: Process vents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-film evaporation, solvent extraction or -air or steam stripping operations man-aging haz-ard-ous wastes... engineering calculations or performance tests. If performance tests are used to determine vent emissions... performance tests must conform with the requirements of § 265.1034(c). (d) When an owner or operator and...

  20. DETAIL VIEW OF ET VENT VALVE ACTUATION PANEL, MAIN FLOOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL VIEW OF ET VENT VALVE ACTUATION PANEL, MAIN FLOOR LEVEL, PLATFORM E-NORTH, HB-3, FACING NORTH - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  1. Hydrocarbon flux from natural deepwater Gulf of Mexico vents

    NASA Astrophysics Data System (ADS)

    Flemings, P. B.; Smith, A. J.

    2012-12-01

    Natural vents that expel water and hydrocarbons are present on continental margins around the world. The expelled fluids support biological vent communities, escape to the ocean and atmosphere, and may contribute significantly to oceanic and atmospheric carbon budgets. We describe two vents in the northern Gulf of Mexico (GoM) at lease blocks MC852/853 and GB425 that have significant flow, high salinities, and elevated temperatures. We use a steady state multi-phase flow model and show that there is a unique water and hydrocarbon flux that simulates the observed salinity and temperature. We estimate the hydrocarbon flux at each vent to be 2.0-9.9x104 t yr-1 and 1.7-7.1x104 t yr-1, respectively. We extrapolate these results and estimate the hydrocarbon flux from the entire Gulf of Mexico to be 9.7-55x106 t yr-1. This flux is at least 50x greater than previous estimates11 and is 6-40% of the hydrocarbon flux from the Macondo oil spill. Large natural seepage may inoculate marine basins such as the Gulf of Mexico from oil spills like the 2010 Deepwater Horizon blowout by sustaining populations of hydrocarbon-degrading bacteria.

  2. CFD analysis of gas explosions vented through relief pipes.

    PubMed

    Ferrara, G; Di Benedetto, A; Salzano, E; Russo, G

    2006-09-21

    Vent devices for gas and dust explosions are often ducted to safe locations by means of relief pipes. However, the presence of the duct increases the severity of explosion if compared to simply vented vessels (i.e. compared to cases where no duct is present). Besides, the identification of the key phenomena controlling the violence of explosion has not yet been gained. Multidimensional models coupling, mass, momentum and energy conservation equations can be valuable tools for the analysis of such complex explosion phenomena. In this work, gas explosions vented through ducts have been modelled by a two-dimensional (2D) axi-symmetric computational fluid dynamic (CFD) model based on the unsteady Reynolds Averaged Navier Stokes (RANS) approach in which the laminar, flamelet and distributed combustion models have been implemented. Numerical test have been carried out by varying ignition position, duct diameter and length. Results have evidenced that the severity of ducted explosions is mainly driven by the vigorous secondary explosion occurring in the duct (burn-up) rather than by the duct flow resistance or acoustic enhancement. Moreover, it has been found out that the burn-up affects explosion severity due to the reduction of venting rate rather than to the burning rate enhancement through turbulization.

  3. 40 CFR 65.143 - Closed vent systems.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) CONSOLIDATED FEDERAL AIR RULE Closed Vent Systems, Control Devices, and Routing to a Fuel Gas System or a... bypass line. (ii) Secure the bypass line valve in the non-diverting position with a car-seal or a lock... procedures specified in Method 21 of appendix A of 40 CFR part 60. (v) Calibration gases shall be...

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... in the open position, will float up and close under the action of a submerging wave. The valve shall... submerging wave; or (iii) Another suitable device acceptable to the Commanding Officer, Marine Safety Center... internal unobstructed area of the required pipe. (9) Where vents are provided with flame screens,...

  5. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... in the open position, will float up and close under the action of a submerging wave. The valve shall... submerging wave; or (iii) Another suitable device acceptable to the Commanding Officer, Marine Safety Center... internal unobstructed area of the required pipe. (9) Where vents are provided with flame screens,...

  6. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... in the open position, will float up and close under the action of a submerging wave. The valve shall... submerging wave; or (iii) Another suitable device acceptable to the Commanding Officer, Marine Safety Center... internal unobstructed area of the required pipe. (9) Where vents are provided with flame screens,...

  7. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... in the open position, will float up and close under the action of a submerging wave. The valve shall... submerging wave; or (iii) Another suitable device acceptable to the Commanding Officer, Marine Safety Center... internal unobstructed area of the required pipe. (9) Where vents are provided with flame screens,...

  8. 46 CFR 56.50-85 - Tank-vent piping.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... in the open position, will float up and close under the action of a submerging wave. The valve shall... submerging wave; or (iii) Another suitable device acceptable to the Commanding Officer, Marine Safety Center... internal unobstructed area of the required pipe. (9) Where vents are provided with flame screens,...

  9. 40 CFR 63.1315 - Continuous process vents provisions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the combined vent stream shall be calculated at the exit of the last recovery device. The TRE shall be... measured at the sampling site described in paragraph (a)(14)(ii) of this section to determine the exit concentration. This exit concentration of total organic HAP or TOC shall then be used to perform...

  10. Variation in the diets of hydrothermal vent gastropods

    NASA Astrophysics Data System (ADS)

    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.

  11. Venting and High Vacuum Performance of Low Density Multilayer Insulation

    NASA Astrophysics Data System (ADS)

    Riesco, M. E.; McLean, C. H.; Mills, G. L.; Buerger, S.; Meyer, M. L.

    2010-04-01

    The NASA Exploration Program is currently studying the use liquid oxygen, liquid methane and liquid hydrogen for propulsion in future spacecraft for Exploration of the Moon and Mars. This will require the efficient long term, on-orbit storage of these cryogenic propellants. Multilayer Insulation (MLI) will be critical to achieving the required thermal performance since it has much lower heat transfer than any other insulation when used in a vacuum. MLI with a low density (⩽10 layers/cm) has been shown in previous work to be the most mass efficient. The size and mass constraints of these propulsion systems will not allow a structural shell to be used to provide vacuum for the MLI during ground hold and launch. The baseline approach is to purge the MLI during ground hold with an inert gas which is then vented during launch ascent and on-orbit. This paper presents the results on experimental tests and modeling performed by Ball Aerospace on low density, non-perforated MLI used to insulate a cryogenic tank simulating an Exploration cryogenic propellant storage vessel. These include measurements of the rate of venting and of the heat transfer of gas filled insulation, fully evacuated insulation and during the transition in between. Results of transient computer modeling of the MLI venting and heat transfer process are also presented. Previous work by some of the authors performed vent testing using MLI with perforations and slits and a slow pump down rate.

  12. Mineralization of Alvinella polychaete tubes at hydrothermal vents.

    PubMed

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-03-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs.

  13. Hydrothermal Vent Sampler: Does Life Exist in High Temperature Environments?

    NASA Technical Reports Server (NTRS)

    Rivadeneyra, Cesar R.

    2005-01-01

    The main purpose of this research is to search for the existence of biomass under extreme temperature and pressure conditions to determine the upper bounds of environments on which life can exist. Vents are, simply put, underwater volcano openings located at the bottom of the sea. The conditions at these locations are considerably extreme with pressures of up to 10,000 psi, and enormous temperature gradients. The temperature of the water near these vents is around 400 C, while that of the surrounding water is about 3 C. The extremity of these conditions makes it hard to estimate the existence of life in those environments. I n order to find whether such existence happens, we need to search for biomass inside these vents. The vent sampler is a device that has the purpose of safely and accurately collecting this biomass for examination. This sampler is constituted of a Series of filters of the order of 100-0.2 microns in size. Since this is a 3-year project, it has not concluded yet; however, during the time I contributed to this project, I worked with the mechanical design of this sampler device including the selection, assembly, and testing of the various subsystems and the design and construction of the electronics enclosure.

  14. 76 FR 44457 - Application of Regulations on Fuel Venting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-26

    ... atmosphere of fuel drained from fuel nozzle manifolds after engines are shut down. By its terms, the... first sentence of that section, that `` o fuel venting emissions shall be discharged into the atmosphere... intentional discharge to the atmosphere of fuel drained from fuel nozzle manifolds after engines are shut...

  15. Mineralization of Alvinella polychaete tubes at hydrothermal vents

    PubMed Central

    Georgieva, M N; Little, C T S; Ball, A D; Glover, A G

    2015-01-01

    Alvinellid polychaete worms form multilayered organic tubes in the hottest and most rapidly growing areas of deep-sea hydrothermal vent chimneys. Over short periods of time, these tubes can become entirely mineralized within this environment. Documenting the nature of this process in terms of the stages of mineralization, as well as the mineral textures and end products that result, is essential for our understanding of the fossilization of polychaetes at hydrothermal vents. Here, we report in detail the full mineralization of Alvinella spp. tubes collected from the East Pacific Rise, determined through the use of a wide range of imaging and analytical techniques. We propose a new model for tube mineralization, whereby mineralization begins as templating of tube layer and sublayer surfaces and results in fully mineralized tubes comprised of multiple concentric, colloform, pyrite bands. Silica appeared to preserve organic tube layers in some samples. Fine-scale features such as protein fibres, extracellular polymeric substances and two types of filamentous microbial colonies were also found to be well preserved within a subset of the tubes. The fully mineralized Alvinella spp. tubes do not closely resemble known ancient hydrothermal vent tube fossils, corroborating molecular evidence suggesting that the alvinellids are a relatively recent polychaete lineage. We also compare pyrite and silica preservation of organic tissues within hydrothermal vents to soft tissue preservation in sediments and hot springs. PMID:25556400

  16. Unsteady-state VOC transport in vented waste drums

    SciTech Connect

    Liekhus, K.J.; Gresham, G.L.; Peterson, E.S.; Rae, C.; Hotz, N.J.; Connolly, M.J.

    1993-08-01

    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.

  17. DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF THE LIQUID HYDROGEN AND LIQUID OXYGEN VENT VALVES, SIXTH LEVEL OF THE EXTERNAL TANK CHECK-OUT CELLS, HB-2, FACING NORTHEAST - Cape Canaveral Air Force Station, Launch Complex 39, Vehicle Assembly Building, VAB Road, East of Kennedy Parkway North, Cape Canaveral, Brevard County, FL

  18. Ephemerality of discrete methane vents in lake sediments

    USGS Publications Warehouse

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

    2016-01-01

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

  19. Iridium alloy Clad Vent Set manufacturing qualification studies

    NASA Astrophysics Data System (ADS)

    Ulrich, George B.

    Metallurgical qualification studies to demonstrate the manufacturing readiness of the iridium alloy Clad Vent Set (CVS) for the General Purpose Heat Source program at the Oak Ridge Y-12 Plant are described. Microstructural data for various materials/test conditions are presented.

  20. 46 CFR 64.63 - Minimum emergency venting capacity.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false Minimum emergency venting capacity. 64.63 Section 64.63 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.63...

  1. 46 CFR 64.63 - Minimum emergency venting capacity.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Minimum emergency venting capacity. 64.63 Section 64.63 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.63...

  2. 46 CFR 64.63 - Minimum emergency venting capacity.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false Minimum emergency venting capacity. 64.63 Section 64.63 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.63...

  3. 46 CFR 64.63 - Minimum emergency venting capacity.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false Minimum emergency venting capacity. 64.63 Section 64.63 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.63...

  4. 46 CFR 64.63 - Minimum emergency venting capacity.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Minimum emergency venting capacity. 64.63 Section 64.63 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.63...

  5. Ephemerality of discrete methane vents in lake sediments

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  6. Assembly room, bunkhouse first floor interior. Vent pipe for missing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Assembly room, bunkhouse first floor interior. Vent pipe for missing heating stove exited through opening into chimney, seen on the far wall. Walls are exposed studs and bracing with board and battan on the exterior and interior sides. - Sespe Ranch, Bunkhouse, 2896 Telegraph Road, Fillmore, Ventura County, CA

  7. 6. Front of northern kiln group, looking west. Vents, plugged ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Front of northern kiln group, looking west. Vents, plugged with loose bricks and clay, are distinguishable in the nearest and farthest kilns, slightly above current grade. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  8. 16. Control Area, Interconnecting Corridor, interior view showing highcapacity venting ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    16. Control Area, Interconnecting Corridor, interior view showing high-capacity venting system and black-out shades on south wall VIEW WEST - NIKE Missile Battery PR-79, Control Area, Tucker Hollow Road south of State Route 101, Foster, Providence County, RI

  9. 46 CFR 182.450 - Vent pipes for fuel tanks.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... installed or equipped to prevent the accidental contamination of the fuel by water under normal operating... reduction in the net cross sectional area of the vent pipe and permit cleaning or renewal of the flame... hose having high resistance to salt water, petroleum oils, heat and vibration, may be used. Such...

  10. Venting test analysis using Jacob`s approximation

    SciTech Connect

    Edwards, K.B.

    1996-03-01

    There are many sites contaminated by volatile organic compounds (VOCs) in the US and worldwide. Several technologies are available for remediation of these sites, including excavation, pump and treat, biological treatment, air sparging, steam injection, bioventing, and soil vapor extraction (SVE). SVE is also known as soil venting or vacuum extraction. Field venting tests were conducted in alluvial sands residing between the water table and a clay layer. Flow rate, barometric pressure, and well-pressure data were recorded using pressure transmitters and a personal computer. Data were logged as frequently as every second during periods of rapid change in pressure. Tests were conducted at various extraction rates. The data from several tests were analyzed concurrently by normalizing the well pressures with respect to extraction rate. The normalized pressures vary logarithmically with time and fall on one line allowing a single match of the Jacob approximation to all tests. Though the Jacob approximation was originally developed for hydraulic pump test analysis, it is now commonly used for venting test analysis. Only recently, however, has it been used to analyze several transient tests simultaneously. For the field venting tests conducted in the alluvial sands, the air permeability and effective porosity determined from the concurrent analysis are 8.2 {times} 10{sup {minus}7} cm{sup 2} and 20%, respectively.

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

    NASA Astrophysics Data System (ADS)

    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

  12. 40 CFR 63.11925 - What are my initial and continuous compliance requirements for process vents?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... vent must meet the emission limits in Table 1 or 2 to this subpart prior to the vent stream being exposed to the atmosphere. The emission limits in Table 1 or 2 to this subpart apply at all times. The emission limits in Table 1 or 2 to this subpart must not be met through dilution. (b) Closed vent...

  13. 40 CFR 63.11925 - What are my initial and continuous compliance requirements for process vents?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... vent must meet the emission limits in Table 1 or 2 to this subpart prior to the vent stream being exposed to the atmosphere. The emission limits in Table 1 or 2 to this subpart apply at all times. The emission limits in Table 1 or 2 to this subpart must not be met through dilution. (b) Closed vent...

  14. 40 CFR 61.349 - Standards: Closed-vent systems and control devices.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Emission Standard for Benzene Waste Operations § 61.349 Standards: Closed-vent systems and control devices... efficiency of 95 weight percent or greater, or shall recover or control the benzene emissions vented to it..., or shall recover or control the benzene emissions vented to it with an efficiency of 98...

  15. 40 CFR 61.349 - Standards: Closed-vent systems and control devices.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Emission Standard for Benzene Waste Operations § 61.349 Standards: Closed-vent systems and control devices... efficiency of 95 weight percent or greater, or shall recover or control the benzene emissions vented to it..., or shall recover or control the benzene emissions vented to it with an efficiency of 98...

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

    PubMed

    He, Tianliang; Zhang, Xiaobo

    2016-04-01

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

  17. 40 CFR 63.11930 - What requirements must I meet for closed vent systems?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... emission limits in Table 1 or 2 to this subpart to a control device, you must use a closed vent system and... process vent, and to route the collected vapors to a control device. (c) Bypass. For each closed vent... control device), you must not discharge to the atmosphere through the bypass. Any such release...

  18. 76 FR 33179 - Petition Requesting Safeguards for Glass Fronts of Gas Vented Fireplaces

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... COMMISSION 16 CFR 1460 Petition Requesting Safeguards for Glass Fronts of Gas Vented Fireplaces AGENCY: U.S... to require safeguards for glass fronts of gas vented fireplaces. We invite written comments... rulemaking to require safeguards for glass fronts of gas vented fireplaces. We are docketing this request...

  19. 40 CFR 61.349 - Standards: Closed-vent systems and control devices.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... management unit vented to the control device except when maintenance or repair of the waste management unit... Emission Standard for Benzene Waste Operations § 61.349 Standards: Closed-vent systems and control devices... process heater) shall meet one of the following conditions: (A) Reduce the organic emissions vented to...

  20. 30 CFR 250.1160 - When may I flare or vent gas?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Requirements Flaring, Venting, and Burning Hydrocarbons § 250.1160 When may I flare or vent gas? (a) You must...) When properly working equipment yields flash gas (natural gas released from liquid hydrocarbons as a... have avoided flaring or venting the gas, the hydrocarbons will be considered avoidably lost or...

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

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Requirements Flaring, Venting, and Burning Hydrocarbons § 250.1160 When may I flare or vent gas? (a) You must...) When properly working equipment yields flash gas (natural gas released from liquid hydrocarbons as a... have avoided flaring or venting the gas, the hydrocarbons will be considered avoidably lost or...

  2. 30 CFR 250.1160 - When may I flare or vent gas?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Requirements Flaring, Venting, and Burning Hydrocarbons § 250.1160 When may I flare or vent gas? (a) You must...) When properly working equipment yields flash gas (natural gas released from liquid hydrocarbons as a... have avoided flaring or venting the gas, the hydrocarbons will be considered avoidably lost or...

  3. 30 CFR 250.1160 - When may I flare or vent gas?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Venting, and Burning Hydrocarbons § 250.1160 When may I flare or vent gas? (a) You must request and...) When properly working equipment yields flash gas (natural gas released from liquid hydrocarbons as a... flaring or venting the gas, the hydrocarbons will be considered avoidably lost or wasted. You must...

  4. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

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

  5. 10 CFR 50.46a - Acceptance criteria for reactor coolant system venting systems.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Acceptance criteria for reactor coolant system venting... criteria for reactor coolant system venting systems. Each nuclear power reactor must be provided with high point vents for the reactor coolant system, for the reactor vessel head, and for other systems...

  6. 40 CFR 63.11930 - What requirements must I meet for closed vent systems?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... operate and maintain your closed vent system in vacuum service as defined in § 63.12005, you must meet the... systems in vacuum service. If you operate and maintain a closed vent system in vacuum service as defined... closed vent system designed to be in vacuum service is operating and not in vacuum service constitutes...

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

    EPA Science Inventory

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

  8. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 95.0 percent through process modifications, or a combination of process modifications and one or more..., shall connect the process vent to a control device or a combination of control devices through a closed... process vent to a control device or combination of control devices through a closed-vent system and...

  9. 40 CFR 63.765 - Glycol dehydration unit process vent standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... reduced by 95.0 percent through process modifications, or a combination of process modifications and one... the process vent to a control device or a combination of control devices through a closed-vent system....771(d). (ii) The owner or operator shall connect the process vent to a control device or...

  10. 40 CFR 63.462 - Batch cold cleaning machine standards.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 10 2012-07-01 2012-07-01 false Batch cold cleaning machine standards... National Emission Standards for Halogenated Solvent Cleaning § 63.462 Batch cold cleaning machine standards. (a) Each owner or operator of an immersion batch cold solvent cleaning machine shall comply with...

  11. 40 CFR 63.462 - Batch cold cleaning machine standards.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 9 2011-07-01 2011-07-01 false Batch cold cleaning machine standards... National Emission Standards for Halogenated Solvent Cleaning § 63.462 Batch cold cleaning machine standards. (a) Each owner or operator of an immersion batch cold solvent cleaning machine shall comply with...

  12. 40 CFR 63.462 - Batch cold cleaning machine standards.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 10 2013-07-01 2013-07-01 false Batch cold cleaning machine standards... National Emission Standards for Halogenated Solvent Cleaning § 63.462 Batch cold cleaning machine standards. (a) Each owner or operator of an immersion batch cold solvent cleaning machine shall comply with...

  13. 40 CFR 63.462 - Batch cold cleaning machine standards.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 9 2010-07-01 2010-07-01 false Batch cold cleaning machine standards... National Emission Standards for Halogenated Solvent Cleaning § 63.462 Batch cold cleaning machine standards. (a) Each owner or operator of an immersion batch cold solvent cleaning machine shall comply with...

  14. A Semi-Batch Reactor Experiment for the Undergraduate Laboratory

    ERIC Educational Resources Information Center

    Derevjanik, Mario; Badri, Solmaz; Barat, Robert

    2011-01-01

    This experiment and analysis offer an economic yet challenging semi-batch reactor experience. Household bleach is pumped at a controlled rate into a batch reactor containing pharmaceutical hydrogen peroxide solution. Batch temperature, product molecular oxygen, and the overall change in solution conductivity are metered. The reactor simulation…

  15. Transient seafloor venting from methane hydrate dissociation on continental slopes

    NASA Astrophysics Data System (ADS)

    Darnell, K.; Flemings, P. B.

    2014-12-01

    We present model results of hydrate dynamics that show the development of a gas chimney at three-phase equilibrium where gas flows through the marine hydrate stability zone and vents into the ocean during transient adjustment to imposed warming. Previous studies show venting occurs at the seaward retreating up-dip boundary of the hydrate stability zone during warming, whereas our results are the first to provide a mechanism for temporary gas venting vertically through the hydrate stability zone during warming. Transient behavior records the combined effect of hydrate dissociation from seafloor warming and secondary hydrate formation from gas produced by hydrate dissociation. We perform simulations of seafloor warming with a 1-d, unsteady, multiphase, fluid-flow model of methane hydrate dynamics. We assume an initial hydrate layer 6o meters thick with 10% pore volume saturation with seawater occupying the remaining domain above and below. We apply an instantaneous temperature increase at the seafloor. The temperature increase propagates downward through the deposit and initiates hydrate dissociation at the base of the deposit. Gas sourced from dissociation migrates upward and re-solidifies as hydrate to a maximum saturation set by a three-phase equilibrium salinity constraint. Additional gas migrates further upward to repeat the process. A chimney defined by dissociation at the bottom, secondary hydrate formation at the top, and maintained at three-phase equilibrium on the interior propagates to the seafloor in 10 kyr. Gas and salt then exit the system by venting into the ocean until dissociation stops producing new gas. Elevated salinities then diffuse to background seawater values. A shorter, shoaled hydrate deposit remains after ~100 kyr. This result shows that temporary venting can potentially occur anywhere along the hydrate stability zone during seafloor warming while retaining a hydrate deposit at steady state.

  16. Assessment of Literature Related to Combustion Appliance Venting Systems

    SciTech Connect

    Rapp, Vi H.; Singer, Brett C.; Stratton, Chris; Wray, Craig P.

    2012-06-01

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

  17. Zero Gravity Cryogenic Vent System Concepts for Upper Stages

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  18. Semiautomated, Reproducible Batch Processing of Soy

    NASA Technical Reports Server (NTRS)

    Thoerne, Mary; Byford, Ivan W.; Chastain, Jack W.; Swango, Beverly E.

    2005-01-01

    A computer-controlled apparatus processes batches of soybeans into one or more of a variety of food products, under conditions that can be chosen by the user and reproduced from batch to batch. Examples of products include soy milk, tofu, okara (an insoluble protein and fiber byproduct of soy milk), and whey. Most processing steps take place without intervention by the user. This apparatus was developed for use in research on processing of soy. It is also a prototype of other soy-processing apparatuses for research, industrial, and home use. Prior soy-processing equipment includes household devices that automatically produce soy milk but do not automatically produce tofu. The designs of prior soy-processing equipment require users to manually transfer intermediate solid soy products and to press them manually and, hence, under conditions that are not consistent from batch to batch. Prior designs do not afford choices of processing conditions: Users cannot use previously developed soy-processing equipment to investigate the effects of variations of techniques used to produce soy milk (e.g., cold grinding, hot grinding, and pre-cook blanching) and of such process parameters as cooking times and temperatures, grinding times, soaking times and temperatures, rinsing conditions, and sizes of particles generated by grinding. In contrast, the present apparatus is amenable to such investigations. The apparatus (see figure) includes a processing tank and a jacketed holding or coagulation tank. The processing tank can be capped by either of two different heads and can contain either of two different insertable mesh baskets. The first head includes a grinding blade and heating elements. The second head includes an automated press piston. One mesh basket, designated the okara basket, has oblong holes with a size equivalent to about 40 mesh [40 openings per inch (.16 openings per centimeter)]. The second mesh basket, designated the tofu basket, has holes of 70 mesh [70 openings

  19. A comparison of black smoker hydrothermal plume behavior at Monolith Vent and at Clam Acres Vent Field: Dependence on source configuration

    NASA Astrophysics Data System (ADS)

    Bemis, Karen G.; Rona, Peter A.; Jackson, Darrell; Jones, Christopher; Silver, Deborah; Mitsuzawa, Kyohiko

    Quantitative visualization of acoustic images is used to compare the properties and behavior of high temperature hydrothermal plumes at two sites with different source configurations, increasing our understanding of how plume behavior reflects source configuration. Acoustic imaging experiments were conducted at the Clam Acres area of the Southwest Vent Field, 21°N East Pacific Rise and at Monolith Vent, North Cleft segment, Juan de Fuca Ridge. At Clam Acres, black smokers discharge from two adjacent chimneys which act as point sources, whereas multiple vents at Monolith Vent define a distributed elliptical source. Both plumes exhibit consistent dilution patterns, reasonable fits to the expected power law increase in centerline dilution with height, and simple bending of plume centerlines in response to ambient currents. Our data suggest that point source vents are associated with ordered plume structure, normal entrainment rates, and initial expansion of isosurfaces while distributed source vents are associated with disorganized plume structure, variable entrainment rates, and initial contraction of isosurfaces.

  20. Production of manufactured aggregates from flue gas desulfurization by-products

    SciTech Connect

    Wu, M.M.; McCoy, D.C.; Fenger, M.L.; Scandrol, R.O.; Winschel, R.A.; Withum, J.A.; Statnick, R.M.

    1999-07-01

    CONSOL R and D has developed a disk pelletization process to produce manufactured aggregates from the by-products of various technologies designed to reduce sulfur emissions produced from coal utilization. Aggregates have been produced from the by-products of the Coolside and LIMB sorbent injection, the fluidized-bed combustion (FBC), spray dryer absorption (SDA), and lime and limestone wet flue gas desulfurization (FGD) processes. The aggregates produced meet the general specifications for use as road aggregate in road construction and for use as lightweight aggregate in concrete masonry units. Small field demonstrations with 1200 lb to 5000 lb of manufactured aggregates were conducted using aggregates produced from FBC ash and lime wet FGD sludge in road construction and using aggregates made from SDA ash and lime wet FGD sludge to manufacture concrete blocks. The aggregates for this work were produced with a bench-scale (200--400 lb batch) unit. In 1999, CONSOL R and D constructed and operated a 500 lb/hr integrated, continuous pilot plant. A variety of aggregate products were produced from lime wet FGD sludge. The pilot plant test successfully demonstrated the continuous, integrated operation of the process. The pilot plant demonstration was a major step toward commercialization of manufactured aggregate production from FGD by-products. In this paper, progress made in the production of aggregates from dry FGD (Coolside, LIMB, SDA) and FBC by-products, and lime wet FGD sludge is discussed. The discussion covers bench-scale and pilot plant aggregate production and aggregate field demonstrations.

  1. SLUDGE BATCH 5 SIMULANT FLOWSHEET STUDIES

    SciTech Connect

    Lambert, D; Michael Stone, M; Bradley Pickenheim, B; David Best, D; David Koopman, D

    2008-10-03

    The Defense Waste Processing Facility (DWPF) will transition from Sludge Batch 4 (SB4) processing to Sludge Batch 5 (SB5) processing in early fiscal year 2009. Tests were conducted using non-radioactive simulants of the expected SB5 composition to determine the impact of varying the acid stoichiometry during the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) processes. The work was conducted to meet the Technical Task Request (TTR) HLW/DWPF/TTR-2007-0007, Rev. 1 and followed the guidelines of a Task Technical and Quality Assurance Plan (TT&QAP). The flowsheet studies are performed to evaluate the potential chemical processing issues, hydrogen generation rates, and process slurry rheological properties as a function of acid stoichiometry. Initial SB5 flowsheet studies were conducted to guide decisions during the sludge batch preparation process. These studies were conducted with the estimated SB5 composition at the time of the study. The composition has changed slightly since these studies were completed due to changes in the washing plan to prepare SB5 and the estimated SB4 heel mass. Nine DWPF process simulations were completed in 4-L laboratory-scale equipment using both a batch simulant (Tank 51 simulant after washing is complete) and a blend simulant (Tank 40 simulant after Tank 51 transfer is complete). Each simulant had a set of four SRAT and SME simulations at varying acid stoichiometry levels (115%, 130%, 145% and 160%). One additional run was made using blend simulant at 130% acid that included additions of the Actinide Removal Process (ARP) waste prior to acid addition and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU) waste following SRAT dewatering. There are several parameters that are noteworthy concerning SB5 sludge: (1) This is the first batch DWPF will be processing that contains sludge that has had a significant fraction of aluminum removed through aluminum dissolution. (2) The sludge is high in mercury

  2. 40 CFR 63.115 - Process vent provisions-methods and procedures for process vent group determination.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... is halogenated, the mass emission rate of halogen atoms contained in organic compounds shall be calculated. (A) The vent stream concentration of each organic compound containing halogen atoms (parts per...) The following equation shall be used to calculate the mass emission rate of halogen atoms:...

  3. 40 CFR 63.115 - Process vent provisions-methods and procedures for process vent group determination.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... is halogenated, the mass emission rate of halogen atoms contained in organic compounds shall be calculated. (A) The vent stream concentration of each organic compound containing halogen atoms (parts per...) The following equation shall be used to calculate the mass emission rate of halogen atoms:...

  4. A deep sea Hydrothermal Vent Bio-sampler for large volume in-situ filtration of hydrothermal vent fluids

    NASA Technical Reports Server (NTRS)

    Behar, Alberto; Matthews, Jaret; Venkateswaran, Kasthuri; Bruckner, James; Basic, Goran; So, Edmond; Rivadeneyra, Cesar

    2005-01-01

    This paper provides a physical description of the current system, as well as a summary of the preliminary tests conducted in 2005: a pressure chamber test, a dive test in a 30 foot dive pool, and a dive operation at a hydrothermal vent off the northern coast of Iceland.

  5. 40 CFR 63.115 - Process vent provisions-methods and procedures for process vent group determination.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... is halogenated, the mass emission rate of halogen atoms contained in organic compounds shall be calculated. (A) The vent stream concentration of each organic compound containing halogen atoms (parts per...) The following equation shall be used to calculate the mass emission rate of halogen atoms:...

  6. BATCH-GE: Batch analysis of Next-Generation Sequencing data for genome editing assessment

    PubMed Central

    Boel, Annekatrien; Steyaert, Woutert; De Rocker, Nina; Menten, Björn; Callewaert, Bert; De Paepe, Anne; Coucke, Paul; Willaert, Andy

    2016-01-01

    Targeted mutagenesis by the CRISPR/Cas9 system is currently revolutionizing genetics. The ease of this technique has enabled genome engineering in-vitro and in a range of model organisms and has pushed experimental dimensions to unprecedented proportions. Due to its tremendous progress in terms of speed, read length, throughput and cost, Next-Generation Sequencing (NGS) has been increasingly used for the analysis of CRISPR/Cas9 genome editing experiments. However, the current tools for genome editing assessment lack flexibility and fall short in the analysis of large amounts of NGS data. Therefore, we designed BATCH-GE, an easy-to-use bioinformatics tool for batch analysis of NGS-generated genome editing data, available from https://github.com/WouterSteyaert/BATCH-GE.git. BATCH-GE detects and reports indel mutations and other precise genome editing events and calculates the corresponding mutagenesis efficiencies for a large number of samples in parallel. Furthermore, this new tool provides flexibility by allowing the user to adapt a number of input variables. The performance of BATCH-GE was evaluated in two genome editing experiments, aiming to generate knock-out and knock-in zebrafish mutants. This tool will not only contribute to the evaluation of CRISPR/Cas9-based experiments, but will be of use in any genome editing experiment and has the ability to analyze data from every organism with a sequenced genome. PMID:27461955

  7. BATCH-GE: Batch analysis of Next-Generation Sequencing data for genome editing assessment.

    PubMed

    Boel, Annekatrien; Steyaert, Woutert; De Rocker, Nina; Menten, Björn; Callewaert, Bert; De Paepe, Anne; Coucke, Paul; Willaert, Andy

    2016-07-27

    Targeted mutagenesis by the CRISPR/Cas9 system is currently revolutionizing genetics. The ease of this technique has enabled genome engineering in-vitro and in a range of model organisms and has pushed experimental dimensions to unprecedented proportions. Due to its tremendous progress in terms of speed, read length, throughput and cost, Next-Generation Sequencing (NGS) has been increasingly used for the analysis of CRISPR/Cas9 genome editing experiments. However, the current tools for genome editing assessment lack flexibility and fall short in the analysis of large amounts of NGS data. Therefore, we designed BATCH-GE, an easy-to-use bioinformatics tool for batch analysis of NGS-generated genome editing data, available from https://github.com/WouterSteyaert/BATCH-GE.git. BATCH-GE detects and reports indel mutations and other precise genome editing events and calculates the corresponding mutagenesis efficiencies for a large number of samples in parallel. Furthermore, this new tool provides flexibility by allowing the user to adapt a number of input variables. The performance of BATCH-GE was evaluated in two genome editing experiments, aiming to generate knock-out and knock-in zebrafish mutants. This tool will not only contribute to the evaluation of CRISPR/Cas9-based experiments, but will be of use in any genome editing experiment and has the ability to analyze data from every organism with a sequenced genome.

  8. Tracking protein aggregate interactions

    PubMed Central

    Bartz, Jason C; Nilsson, K Peter R

    2011-01-01

    Amyloid fibrils share a structural motif consisting of highly ordered β-sheets aligned perpendicular to the fibril axis.1, 2 At each fibril end, β-sheets provide a template for recruiting and converting monomers.3 Different amyloid fibrils often co-occur in the same individual, yet whether a protein aggregate aids or inhibits the assembly of a heterologous protein is unclear. In prion disease, diverse prion aggregate structures, known as strains, are thought to be the basis of disparate disease phenotypes in the same species expressing identical prion protein sequences.4–7 Here we explore the interactions reported to occur when two distinct prion strains occur together in the central nervous system. PMID:21597336

  9. Zooplankton Aggregations Near Sills

    DTIC Science & Technology

    2003-09-30

    frequency echo-sounder system. This data were supplemented with multi-net (BIONESS) trawls, bongo nets, and otter trawls (operated by D. Mackas and group...side. The general composition of the zooplankton aggregations can be deduced from the relative levels of the three echo-sounder frequencies; krill ...Nov. 20th, 2002. Krill layer is evident at 66 – 90 m, coincident with BIONESS trawl through the region. 3 Figure 2 shows a comparison between

  10. System for charging batch/cullet in a glass furnace

    SciTech Connect

    Argent, R.D.; Crouse, C.F.

    1992-06-23

    This patent describes a charger for feeding batch material and cullet to a glass melting furnace, the charger of the type having a support frame with a batch hopper therein and a reciprocable charger plate positioned under the hopper for receiving batch material therefrom. This patent describes improvement in: a cullet feed hopper mounted on the charger adjacent to the batch hopper and positioned between the batch hopper and a discharge end of the charger; heat exchange means associated with the cullet feed hopper for preheating the cullet therein: and duct means associated with the heat exchange means adapted to receive hot exhaust gases from the glass furnace for preheating the cullet.

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

    NASA Astrophysics Data System (ADS)

    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).

  12. Inhomogeneites dans le Vent des Etoiles Wolf-Rayet

    NASA Astrophysics Data System (ADS)

    Robert, Carmelle

    1992-01-01

    Des mesures spectroscopiques effectuees avec un haut rapport signal sur bruit et une bonne resolution ont demontre l'existence de regions perturbees en mouvement dans le vent d'etoiles Wolf-Rayet (WR). L'echantillon d'objets etudies ici comprend 9 etoiles WR couvrant differents sous-types WN et WC. De nombreuses petites structures variables superposees au profil des raies d'emission formees dans le vent stellaire signalent la presence des perturbations. L'etude des variations globales des raies et l'examen des micro-structures individuelles ont permis de decrire plusieurs caracteristiques des perturbations. Entre autres, on observe des correlations significatives entre le niveau de variabilite des raies et certains parametres des etoiles qui confirment que le phenomene de variabilite est intrinseque au vent stellaire. En comparant les changements des vitesses radiales et des largeurs equivalentes des differentes raies d'une meme etoile, on conclut que les regions perturbees ont une etendue finie par rapport a l'enveloppe des etoiles. On peut facilement suivre les structures individuelles sur une periode de temps couvrant ~eq8 heures (et peut etre meme 24 heures) avant qu'elles ne disparaissent. Durant ce temps les structures se deplacent en s'eloignant du centre de la raie. A partir des differents comportements notes lors de l'analyse des variations globales et lors de l'examen des structures individuelles, on propose de representer les perturbations par un modele d'inhomogeneites discretes en expansion dans le vent. On suppose simplement que les inhomogeneites emettent comme le vent global (et absorbent aussi si le vent global montre un profil P Cyg). La superposition du graphique de l'acceleration radiale moyenne des inhomogeneites de WR140 en fonction de leur vitesse radiale et du modele theorique d'inhomogeneites qui suivent la loi generale de vitesse donne un taux d'acceleration lent, avec beta >= 3 pour les inhomogeneites de cette etoile. On obtient, entre

  13. Degassing during magma ascent in the Mule Creek vent (USA)

    USGS Publications Warehouse

    Stasiuk, M.V.; Barclay, J.; Carroll, M.R.; Jaupart, Claude; Ratte, J.C.; Sparks, R.S.J.; Tait, S.R.

    1996-01-01

    The structures and textures of the rhyolite in the Mule Creek vent (New Mexico, USA) indicate mechanisms by which volatiles escape from silicic magma during eruption. The vent outcrop is a 300-m-high canyon wall comprising a section through the top of a feeder conduit, vent and the base of an extrusive lava dome. Field relations show that eruption began with an explosive phase and ended with lava extrusion. Analyses of glass inclusions in quartz phenocrysts from the lava indicate that the magma had a pre-eruptive dissolved water content of 2.5-3.0 wt% and, during eruption, the magma would have been water-saturated over the vertical extent of the present outcrop. However, the vesicularity of the rhyolite is substantially lower than that predicted from closed-system models of vesiculation under equilibrium conditions. At a given elevation in the vent, the volume fraction of primary vesicles in the rhyolite increases from zero close to the vent margin to values of 20-40 vol.% in the central part. In the centre the vesicularity increases upward from approximately 20 vol.% at 300 m below the canyon rim to approximately 40 vol.% at 200 m, above which it shows little increase. To account for the discrepancy between observed vesicularity and measured water content, we conclude that gas escaped during ascent, probably beginning at depths greater than exposed, by flow through the vesicular magma. Gas escape was most efficient near the vent margin, and we postulate that this is due both to the slow ascent of magma there, giving the most time for gas to escape, and to shear, favouring bubble coalescence. Such shear-related permeability in erupting magma is supported by the preserved distribution of textures and vesicularity in the rhyolite: Vesicles are flattened and overlapping near the dense margins and become progressively more isolated and less deformed toward the porous centre. Local zones have textures which suggest the coalescence of bubbles to form permeable

  14. Proteins aggregation and human diseases

    NASA Astrophysics Data System (ADS)

    Hu, Chin-Kun

    2015-04-01

    Many human diseases and the death of most supercentenarians are related to protein aggregation. Neurodegenerative diseases include Alzheimer's disease (AD), Huntington's disease (HD), Parkinson's disease (PD), frontotemporallobar degeneration, etc. Such diseases are due to progressive loss of structure or function of neurons caused by protein aggregation. For example, AD is considered to be related to aggregation of Aβ40 (peptide with 40 amino acids) and Aβ42 (peptide with 42 amino acids) and HD is considered to be related to aggregation of polyQ (polyglutamine) peptides. In this paper, we briefly review our recent discovery of key factors for protein aggregation. We used a lattice model to study the aggregation rates of proteins and found that the probability for a protein sequence to appear in the conformation of the aggregated state can be used to determine the temperature at which proteins can aggregate most quickly. We used molecular dynamics and simple models of polymer chains to study relaxation and aggregation of proteins under various conditions and found that when the bending-angle dependent and torsion-angle dependent interactions are zero or very small, then protein chains tend to aggregate at lower temperatures. All atom models were used to identify a key peptide chain for the aggregation of insulin chains and to find that two polyQ chains prefer anti-parallel conformation. It is pointed out that in many cases, protein aggregation does not result from protein mis-folding. A potential drug from Chinese medicine was found for Alzheimer's disease.

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

    PubMed Central

    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

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

    PubMed

    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.

  17. Individual hydrothermal vents at Axial Seamount harbor distinct subseafloor microbial communities.

    PubMed

    Opatkiewicz, Andrew D; Butterfield, David A; Baross, John A

    2009-12-01

    The microbial community structure of five geographically distinct hydrothermal vents located within the Axial Seamount caldera, Juan de Fuca Ridge, was examined over 6 years following the 1998 diking eruptive event. Terminal restriction fragment length polymorphism (TRFLP) and 16S rRNA gene sequence analyses were used to determine the bacterial and archaeal diversity, and the statistical software primer v6 was used to compare vent microbiology, temperature and fluid chemistry. Statistical analysis of vent fluid temperature and composition shows that there are significant differences between vents in any year, but that the fluid composition changes over time such that no vent maintains a chemical composition completely distinct from the others. In contrast, the subseafloor microbial communities associated with individual vents changed from year to year, but each location maintained a distinct community structure (based on TRFLP and 16S rRNA gene sequence analyses) that was significantly different from all other vents included in this study. Epsilonproteobacterial microdiversity is shown to be important in distinguishing vent communities, while archaeal microdiversity is less variable between sites. We propose that persistent venting at diffuse flow vents over time creates the potential to isolate and stabilize diverse microbial community structures between vents.

  18. [A new heat and moisture exchanger, Trach-Vent Plus, for patients with spontaneous respiration].

    PubMed

    Nishiyama, Tomoki; Hanaoka, Kazuo

    2003-04-01

    A new heat and moisture exchanger, Trach-Vent Plus is now available in Japan. A heat and moisture exchanger, Trach-Vent and oxygen-supplying tool, Oxy-Vent are made in one unit as a Trach-Vent Plus. This is smaller and lighter than the combination of Trach-Vent and Oxy-Vent. Oxygen supplying tube can be connected to the side of the filter. There is a silicon membrane with slits in the center of the tool, to which patients's airway opens directly. The membrane prevents patients from dust, but suction of sputa is easy through the slits. This new heat and moisture exchanger, Trach-Vent Plus is useful to administer oxygen to intubated patients breathing spontaneously, especially with tracheostomy.

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

    NASA Astrophysics Data System (ADS)

    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

  20. 30 CFR 250.1161 - When may I flare or vent gas for extended periods of time?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false When may I flare or vent gas for extended... Production Requirements Flaring, Venting, and Burning Hydrocarbons § 250.1161 When may I flare or vent gas... flare or vent gas for an extended period of time. The Regional Supervisor will specify the...

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

    NASA Technical Reports Server (NTRS)

    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.

  2. VOC transport in vented drums containing simulated waste sludge

    SciTech Connect

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

    1994-02-01

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

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

    SciTech Connect

    Hanson, D.J.; Blackman, H.S.; Nelson, W.R.; Wright, R.E.; Leonard, M.T.; DiSalvo, R.

    1986-12-01

    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.

  4. Device and method for remotely venting a container

    DOEpatents

    Vodila, James M.; Bergersen, Jeffrey A.

    1997-01-01

    A device for venting a container having a bung includes a saddle assembly curable to a container and having a support extending therefrom. A first arm is rotatably secured to the support, and the first arm extends in a first direction. A second arm has a first end portion drivingly engaged with the first arm, so that rotation of the first arm causes rotation of the second arm. A second end portion of the first arm is positionable proximate the bung of the container. A socket is operably associated and rotatable with the second end portion and is drivingly engageable with the bung, so that rotation of the socket causes corresponding rotation of the bung for thereby venting the container.

  5. Request for approval, vented container annual release fraction

    SciTech Connect

    HILL, J.S.

    1999-10-12

    In accordance with the approval conditions for Modification to the Central Waste Complex (CWC) Radioactive Air Emissions Notice of Construction (NOC). dated August 24,1998, a new release fraction has been developed for submittal to the Washington State Department of Health (WDOH). The proposed annual release fraction of 2.50 E-14 is proposed for use in future NOCs involving the storage and handling operations associated with vented containers on the Hanford Site. The proposed annual release fraction was the largest release fraction calculated from alpha measurements of the NucFil filters from 10 vented containers consisting of nine 55-gallon drums and one burial box with dimensions of 9.3 x 5.7 x 6.4 feet. An annual release fraction of 2.0 E-09 was used in the modification to the CWC radioactive air emissions NOC. This study confirmed that the release fraction used in the CWC radioactive air emissions NOC was conservative.

  6. Emergency relief venting of the infrared telescope liquid helium dewar

    NASA Technical Reports Server (NTRS)

    Urban, E. W.

    1980-01-01

    An analysis is made of the emergency relief venting of the liquid helium dewar of the Spacelab 2 infrared telescope experiment in the event of a massive failure of the dewar guard vacuum. Such a failure, resulting from a major accident, could cause rapid heating and pressurization of the liquid helium in the dewar and lead to relief venting through the emergency relief system. The heat input from an accident is estimated for various fluid conditions in the dewar and the relief process as it takes place through one or both of the emergency relief paths is considered. It is shown that under all reasonable circumstances the dewar will safely relieve itself, and the pressure will not exceed 85 percent of the proof pressure or 63 percent of the burst pressure.

  7. Optimization of contaminant removal for heterogeneous systems by soil venting

    SciTech Connect

    Walton, J.C.; Casey, D.; Anker, C.; LeMone, D.

    1996-12-31

    The efficiency of remediation of vadose zone organic compounds can be enhanced by refinement of methods for soil venting and bioventing in complex heterogeneous systems. This can be accomplished by (a) identification of physical and chemical conditions (e.g., soil temperature, moisture content, flow rates) required for rapid contaminant removal rates, (b) precise engineering control of identified parameters in the subsurface, and (c) development of knowledge-based operational strategies providing greater removal efficiencies at low cost. One method with promise is to moderately heat and humidify the input/replacement air during venting. Initial calculations indicate that this strategy may be quite effective in enhancing remediation of heterogeneous systems with diffusional control of cleanup time.

  8. The influence of erythrocyte aggregation on induced platelet aggregation.

    PubMed

    Ott, C; Lardi, E; Schulzki, T; Reinhart, W H

    2010-01-01

    Red blood cells (RBCs) affect platelet aggregation in flowing blood (primary hemostasis). We tested the hypothesis that RBC aggregation could influence platelet aggregation. RBC aggregation was altered in vitro by: (i) changing plasma aggregatory properties with 3.7 g% dextran 40 (D40), 3.0 g% dextran 70 (D70) or 1.55 g% dextran 500 (D500); (ii) changing RBC aggregatory properties by incubating RBCs in 50 mU/ml neuraminidase for 60 min (reduction of the surface sialic acid content, thus reducing electrostatic repulsion) and subsequent RBC resuspension in platelet rich plasma (PRP) containing 1 g% dextran 70. RBC aggregation was assessed with the sedimentation rate (ESR). Platelet aggregation was measured: (i) in flowing whole blood with a platelet function analyzer PFA-100(R), which simulates in vivo conditions with RBCs flowing in the center and platelets along the wall, where they adhere to collagen and aggregate; and (ii) in a Chrono-log 700 Aggregometer, which measures changes of impedance by platelet aggregation in whole blood or changes in light transmission in PRP. We found that RBC aggregation increased with increasing molecular weight of dextran (ESR: 4 +/- 3 mm/h, 34 +/- 14 mm/h and 89 +/- 23 mm/hfor D40, D70 and D500, respectively, p < 0.0001) and with neuraminidase-treated RBCs (76 +/- 27 mm/h vs 27 +/- 8 mm/h, respectively, p < 0.0001). Platelet aggregation measured in whole blood under flow conditions (PFA-100) and without flow (Chronolog Aggregometer) was not affected by RBC aggregation. Our data suggest that RBC aggregation does not affect platelet aggregation in vitro and plays no role in primary hemostasis.

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

    NASA Astrophysics Data System (ADS)

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

    2016-10-01

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

  10. Hydro-Thermal Vent Mapping with Multiple AUV’s

    DTIC Science & Technology

    2016-06-07

    Lisbon (IST) have a long standing memorandum of agreement dating back to 1994 for the exchange of scientific ideas, visits of faculty and students...and to perform collaborative work . In the past we have collaborated on joint papers, the shared supervision of doctoral work , and a shared effort on the...a scientific need to study the vents with more detail than possible using divers and cameras, this also presents a parallel to the mine field

  11. Chemistry of hydrothermal solutions from Pele's Vents, Loihi Seamount, Hawaii

    SciTech Connect

    Sedwick, P.N.; McMurtry, G.M. ); Macdougall, J.D. )

    1992-10-01

    Hydrothermal fluids were sampled from Pele's Vents on the summit of Loihi Seamount, an intraplate, hotspot volcano, on four occasions from February 1987 to September 1990. The warm ([le]31C) vent solutions are enriched in dissolved Si, CO[sub 2], H[sub 2]S, alkalinity, K[sup +], Li[sup +], Rb[sup +], Ca[sup 2+], Ba[sup 2+], Fe[sup 2+], Mn[sup 2+], NH[sup +][sub 4], and possibly Ni[sup 2+], and depleted in SO[sup 2-][sub 4], O[sub 2], Mg[sup 2+], [sup 87]Sr/[sup 86]Sr, NO[sup -][sub 3], and sometimes Cl[sup -] and Na[sup +] (calculated), relative to ambient seawater. Dissolved Si correlates linearly with sample temperature, suggesting that the solutions sampled from numerous vents in the [approximately]20 m diameter field have a common source and that Si can be used as a conservative tracer for mixing of the vent fluids with ambient seawater. These juvenile inputs likely reflect the shallow, hotspot setting of this hydrothermal system. A simple quantitative fluid-history model is considered and shown to be consistent with mass-balance constraints and saturation-state calculations, which suggest that the Si concentration of the fluids may be controlled by amorphous silica saturation at [approximately]31C. Observed temporal variations in fluid composition between expeditions - specifically, in Cl[sup -], A[sub T], C[sub T], Na[sup +] (calculated), Mg[sup 2+], Ca[sup 2+], Sr[sup 2+], [sup 87]Sr/[sup 86]Sr, Fe[sup 2+], Mn[sup 2+] and perhaps NH[sup +][sub 4], relative to Si - are, excepting Mg[sup 2+], [sup 87]Sr/[sup 86]Sr, and Mn[sup 2+], consistent with the effects of variable phase segregation at the proposed high-temperature endmember.

  12. Shaped Charge Jet/Propellant Interactions in a Vented Compartment.

    DTIC Science & Technology

    1979-12-01

    the vented ammunition compartment. One of these was the Susquehanna Instruments Model ST-4 tourmaline transducer, a nonresonant transducer capable of...S1-4 tourmaline gauges and those at positons 3 and 4 were Kistler Model 617A tourmaline gauges. Thin strips of metal were welded over the trans- ducers...two different types of piezoelectric transducers. One was a fast almost totally non- resonant though somewhat temperature sensitive Tourmaline bar gauge

  13. Halophilic Archaea determined from geothermal steam vent aerosols.

    PubMed

    Ellis, Dean G; Bizzoco, Richard W; Kelley, Scott T

    2008-06-01

    Hydrothermal vents, known as 'fumaroles', are ubiquitous features of geothermal areas. Although their geology has been extensively characterized, little is known about the subsurface microbial ecology of fumaroles largely because of the difficulty in collecting sufficient numbers of cells from boiling steam water for DNA extraction and culture isolation. Here we describe the first collection, molecular analysis and isolation of microbes from fumarole steam waters in Russia (Kamchatka) and the USA (Hawaii, New Mexico, California and Wyoming). Surprisingly, the steam vent waters from all the fumaroles contained halophilic Archaea closely related to the Haloarcula spp. found in non-geothermal salt mats, saline soils, brine pools and salt lakes around the world. Microscopic cell counting estimated the cell dispersal rate at approximately 1.6 x 10(9) cells year(-1) from a single fumarole. We also managed to enrich microbes in high-salt media from every vent sample, and to isolate Haloarcula from a Yellowstone vent in a 20% salt medium after a month-long incubation, demonstrating both salt tolerance and viability of cells collected from high-temperature steam. Laboratory tests determined that microbes enriched in salt media survived temperatures greater than 75 degrees C for between 5 and 30 min during the collection process. Hawaiian fumaroles proved to contain the greatest diversity of halophilic Archaea with four new lineages that may belong to uncultured haloarchaeal genera. This high diversity may have resulted from the leaching of salts and minerals through the highly porous volcanic rock, creating a chemically complex saline subsurface.

  14. Complete mitochondrial genome of hydrothermal vent clam Calyptogena magnifica.

    PubMed

    Liu, Helu; Cai, Shanya; Zhang, Haibin; Vrijenhoek, Robert C

    2016-11-01

    The mitochondrial genome of the hydrothermal vent clam Calyptogena magnifica (Bivalvia, Veneroida, Vesicomyidae) is reported for the first time in this study. The total length of its mitochondrial genome is 19 738 bp with overall GC content of 31.6%. The mitochondrial genome consists of 36 genes, including 13 protein-coding sequences, 2 rRNA and 21 tRNA genes. Two distinct repeat motifs are located between tRNA(Trp) and ND6.

  15. Phenomenology of a Water Venting in Low Earth Orbit

    DTIC Science & Technology

    1992-01-01

    the three electronic cameras, typical views aerochemical and dynamical effects (6], and con- of the particle clouds from which are reproduced in...same initial flow bursts), so that the initial expansion of this vapor is conditions as in space shuttle’s now-routine vent- collisional . This gas then... simulation chamber [91 Nb. The to%%ard the particle trail (refer to Table I and centing nozzle is about 5 m from the nearest segment of the Fig. 2(a

  16. TRANSPORT OF WASTE SIMULANTS IN PJM VENT LINES

    SciTech Connect

    Qureshi, Z

    2007-02-21

    The experimental work was conducted to determine whether there is a potential for waste simulant to transport or 'creep' up the air link line and contaminate the pulse jet vent system, and possibly cause long term restriction of the air link line. Additionally, if simulant creep occurred, establish operating parameters for washing down the line. The amount of the addition of flush fluids and mixer downtime must be quantified.

  17. Structure of Viral Aggregates

    NASA Astrophysics Data System (ADS)

    Barr, Stephen; Luijten, Erik

    2010-03-01

    The aggregation of virus particles is a particular form of colloidal self-assembly, since viruses of a give type are monodisperse and have identical, anisotropic surface charge distributions. In small-angle X-ray scattering experiments, the Qbeta virus was found to organize in different crystal structures in the presence of divalent salt and non-adsorbing polymer. Since a simple isotropic potential cannot explain the occurrence of all observed phases, we employ computer simulations to investigate how the surface charge distribution affects the virus interactions. Using a detailed model of the virus particle, we find an asymmetric ion distribution around the virus which gives rise to the different phases observed.

  18. Hydrocarbon flux from natural deepwater Gulf of Mexico vents

    NASA Astrophysics Data System (ADS)

    Smith, Andrew J.; Flemings, Peter B.; Fulton, Patrick M.

    2014-06-01

    High salinities and high temperatures at the seafloor record the upward flow of water and hydrocarbons from depth at natural vents in the deepwater Gulf of Mexico. We present a multiphase heat- and solute-transport model, in which water supplied from depth transports heat and salt, and hydrocarbon transports heat. We show that there is a unique water and hydrocarbon flux that simulates the observed salinity and temperature. We estimate the hydrocarbon flux to be 3.2-15×104 t yr and 1.8-8.0×104 t yr from two vents at lease blocks MC852/853 and GB425. These fluxes are 1-4 orders of magnitude greater than previous estimates from individual deepwater vents. If these results are extrapolated to the entire Gulf of Mexico, then we estimate the regional hydrocarbon flux to be at least 100× greater than previous estimates and 14-120% of the hydrocarbon flux from the Macondo oil spill. Large natural seepage may inoculate marine basins such as the Gulf of Mexico from oil spills like the 2010 Deepwater Horizon blowout by sustaining populations of hydrocarbon-degrading bacteria.

  19. Simulating the venting of radioactivity from a soviet nuclear test

    NASA Astrophysics Data System (ADS)

    Rodriguez, Daniel J.; Peterson, Kendall R.

    Fresh fission products were found in several routine air samples in Europe during the second and third weeks of March 1987. Initially, it was suspected that the radionuclides, principally 133Xe and 131I, had been accidentally released from a European facility handling nuclear materials. However, the announcement of an underground nuclear test at Semipalatinsk, U.S.S.R. on 26 February 1987 suggested that the elevated amounts of radioactivity may, instead, have been caused by a venting episode. Upon learning of these events, we simulated the transport and diffusion of 133Xe with our Hemispheric MEDIC and ADPIC models, assuming Semipalatinsk to be the source of the radioactive emissions. The correspondence between the calculated concentrations and the daily average 133Xe measurements made by the Federal Office for Civil Protection in F.R.G. was excellent. While this agreement does not, in itself, prove that an atmospheric venting of radioactive material occurred at Semipalatinsk, a body of circumstantial evidence exists which, when added together, strongly supports this conclusion. Our calculations suggested a total fission yield of about 40 kt, which is within the 20-150 kt range of tests acknowledged by the U.S.S.R. Finally, dose calculations indicated that no health or environmental impact occurred outside of the U.S.S.R. due to the suspected venting of 133Xe. However, the inhalation dose resulting from 133I, an unmodeled component of the radioactive cloud, represented a greater potential risk to public health.

  20. Constrained circulation at Endeavour ridge facilitates colonization by vent larvae.

    PubMed

    Thomson, Richard E; Mihály, Steven F; Rabinovich, Alexander B; McDuff, Russell E; Veirs, Scott R; Stahr, Frederick R

    2003-07-31

    Understanding how larvae from extant hydrothermal vent fields colonize neighbouring regions of the mid-ocean ridge system remains a major challenge in oceanic research. Among the factors considered important in the recruitment of deep-sea larvae are metabolic lifespan, the connectivity of the seafloor topography, and the characteristics of the currents. Here we use current velocity measurements from Endeavour ridge to examine the role of topographically constrained circulation on larval transport along-ridge. We show that the dominant tidal and wind-generated currents in the region are strongly attenuated within the rift valley that splits the ridge crest, and that hydrothermal plumes rising from vent fields in the valley drive a steady near-bottom inflow within the valley. Extrapolation of these findings suggests that the suppression of oscillatory currents within rift valleys of mid-ocean ridges shields larvae from cross-axis dispersal into the inhospitable deep ocean. This effect, augmented by plume-driven circulation within rift valleys having active hydrothermal venting, helps retain larvae near their source. Larvae are then exported preferentially down-ridge during regional flow events that intermittently over-ride the currents within the valley.

  1. Sulphur isotopic compositions of deep-sea hydrothermal vent animals

    NASA Technical Reports Server (NTRS)

    Fry, B.; Gest, H.; Hayes, J. M.

    1983-01-01

    The S-34/S-32 ratios of tissues from vestimentiferan worms, brachyuran crabs, and giant clams living around deep hydrothermal vents are reported. Clean tissues were dried, ground, suspended in 0.1 M LiCl, shaken twice at 37 C to remove seawater sulfates, dried at 60 C, combusted in O2 in a Parr bomb. Sulfur was recovered as BaSO4, and the isotopic abundances in SO2 generated by thermal decomposition of 5-30-mg samples were determined using an isotope-ratio mass spectrometer. The results are expressed as delta S-34 and compared with values measured in seawater sulfates and in normal marine fauna. The values ranged from -4.7 to 4.7 per thousand, comparable to vent sulfide minerals (1.3-4.1 per thousand) and distinct from seawater sulfates (20.1 per thousand) and normal marine fauna (about 13-20 per thousand). These results indicate that vent sulfur rather than seawater sulfur is utilized by these animals, a process probably mediated by chemoautotrophic bacteria which can use inorganic sulfur compounds as energy sources.

  2. Potential VOC Deflagrations in a Vented TRU Drum

    SciTech Connect

    Mukesh, GUPTA

    2005-04-07

    The objective of the analysis is to examine the potential for lid ejection from a vented transuranic (TRU) waste drum due to pressure buildup caused by the deflagration of hydrogen and volatile organic compounds (VOCs) inside the drum. In this analysis, the AICC pressure for a stoichiometric mixture of VOCs is calculated and then compared against the experimental peak pressure of stoichiometric combustion of propane and hexane in a combustion chamber. The experimental peak pressures of propane and hexane are about 12 percent lower than the calculated AICC pressure. Additional losses in the drum are calculated due to venting of the gases, drum bulging, waste compaction, and heat losses from the presence of waste in the drum. After accounting for these losses, the final pressures are compared to the minimum observed pressure that ejects the lid from a TRU drum. The ejection pressure of 105 psig is derived from data that was recorded for a series of tests where hydrogen-air mixtures were ignited inside sealed TRU drums. Since the calculated pressures are below the minimum lid ejection pressure, none of the VOCs and the hydrogen (up to 4 percent) mixtures present in the TRU waste drum is expected to cause lid ejection if ignited. The analysis of potential VOC deflagrations in a vented TRU drum can be applied across the DOE-Complex since TRU waste is stored in drums throughout the complex.

  3. Vented spikes improve delivery from intravenous bags with no air headspace.

    PubMed

    Galush, William J; Horst, Travis A

    2015-07-01

    Flexible plastic bags are the container of choice for most intravenous (i.v.) infusions. Under certain circumstances, however, the air-liquid interface present in these i.v. bags can lead to physical instability of protein biopharmaceuticals, resulting in product aggregation. In principle, the air headspace present in the bags can be removed to increase drug stability, but experiments described here show that this can result in incomplete draining of solution from the bag using gravity delivery, or generation of negative pressure in the bag when an infusion pump is used. It is expected that these issues could lead to incomplete delivery of medication to patients or pump-related problems, respectively. However, here it is shown that contrary to the standard pharmacy practice of using nonvented spikes with i.v. bags, the use of vented spikes with i.v. bags that lack air headspace allows complete delivery of the dose solution without impacting the physical stability of a protein-based drug.

  4. Vent sizing: analysis of the blowdown of a hybrid non tempered system.

    PubMed

    Véchot, Luc; Minko, Wilfried; Bigot, Jean-Pierre; Kazmierczak, Marc; Vicot, Patricia

    2011-07-15

    The runaway and blowdown of a non tempered hybrid chemical system (30% cumene hydroperoxide) exposed to an external heat input was investigated using a 0.1l scale tool. The maximum temperature and the maximum temperature rise rate were showed to be sensitive to the vent size. An Antoine type correlation between the maximum temperatures and pressures was observed. These resulted from the presence of vapour, mainly generated by the reaction products. Increasing the initial filling ratio resulted in an earlier vent opening but did not have a significant influence on the blow-down. Three types of mass venting behaviour were observed, when changing the vent area to volume ratio (A/V): • for large A/V, two-phase venting occurred from the vent opening until the end of the second pressure peak; • for medium A/V, two-phase venting occurred before and after the turnaround. The data seem to indicate that gas only venting occurred at turn-around; • for low A/V, two-phase venting was observed only after the second pressure peak. Two-phase venting after the second pressure peak probably results from the boiling of the hot reaction products at low pressure.

  5. A biogeographic network reveals evolutionary links between deep-sea hydrothermal vent and methane seep faunas.

    PubMed

    Kiel, Steffen

    2016-12-14

    Deep-sea hydrothermal vents and methane seeps are inhabited by members of the same higher taxa but share few species, thus scientists have long sought habitats or regions of intermediate character that would facilitate connectivity among these habitats. Here, a network analysis of 79 vent, seep, and whale-fall communities with 121 genus-level taxa identified sedimented vents as a main intermediate link between the two types of ecosystems. Sedimented vents share hot, metal-rich fluids with mid-ocean ridge-type vents and soft sediment with seeps. Such sites are common along the active continental margins of the Pacific Ocean, facilitating connectivity among vent/seep faunas in this region. By contrast, sedimented vents are rare in the Atlantic Ocean, offering an explanation for the greater distinction between its vent and seep faunas compared with those of the Pacific Ocean. The distribution of subduction zones and associated back-arc basins, where sedimented vents are common, likely plays a major role in the evolutionary and biogeographic connectivity of vent and seep faunas. The hypothesis that decaying whale carcasses are dispersal stepping stones linking these environments is not supported.

  6. Detailed dynamics and seasonal persistence of methane venting from lakes

    NASA Astrophysics Data System (ADS)

    Scandella, B. P.; Wood, H. G.; Ruppel, C. D.; Hemond, H.; Juanes, R.

    2012-12-01

    Lake-bottom sediments emit methane, a potent greenhouse gas, into the overlying water column and atmosphere. A large fraction of the methane is released as bubbles, but constraining the magnitude of this methane flux is challenging because ebullition is patchy in space and episodic in time. Extrapolating observations from individual methane seeps to a larger scale in time or space can result in severe over- or under-estimation of the methane flux, yet to date observations have not combined large, complete spatial coverage with multiple-season deployment periods. We present methane ebullition data from a fixed-location multibeam sonar, which observes a large area (420 m2) over a deployment period of over 6 months and with sufficient spatiotemporal resolution to detect individual bubbles. The large amount of data generated by the system presents a challenge to identify bubble signals that are infrequent, short in duration, and spatially compact. Addressing this challenge yields processed ebullition signals, which are compared against vents detected in the water column and near-surface sediment during geophysical surveys that utilize a commercial fishfinder sonar and a 4-24 kHz chirp seismic towfish. The ebullition signals are then used to develop conceptual models relating distributed methanogenesis to ebullition at localized sites. In particular, the spacing and persistence of vents implies potential mechanisms for their creation and maintenance, while the ebullitive response to hydrostatic pressure variations is used to validate a conduit dilation model of methane venting. Finally, the level of synchronicity in activity between distant venting sites suggests the relative importance of the external hydrostatic forcing over internal dynamics of methane generation. The mechanistic understanding provided by this work is critical to upscaling gas flow measurements from individual vents to infer lake-wide fluxes to the water column and atmosphere. Map of maximum sonar

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

    SciTech Connect

    Tiercelin, J.J.; Pflumio, C.; Castrec, M.

    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.

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

    NASA Astrophysics Data System (ADS)

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

    2002-12-01

    The euryhaline halophilic microorganisms grow in a wide salinity range from <3% NaCl (seawater equivalent) to >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

  9. Leaching assessment of concrete made of recycled coarse aggregate: physical and environmental characterisation of aggregates and hardened concrete.

    PubMed

    Galvín, A P; Agrela, F; Ayuso, J; Beltrán, M G; Barbudo, A

    2014-09-01

    Each year, millions of tonnes of waste are generated worldwide, partially through the construction and demolition of buildings. Recycling the resulting waste could reduce the amount of materials that need to be manufactured. Accordingly, the present work has analysed the potential reuse of construction waste in concrete manufacturing by replacing the natural aggregate with recycled concrete coarse aggregate. However, incorporating alternative materials in concrete manufacturing may increase the pollutant potential of the product, presenting an environmental risk via ground water contamination. The present work has tested two types of concrete batches that were manufactured with different replacement percentages. The experimental procedure analyses not only the effect of the portion of recycled aggregate on the physical properties of concrete but also on the leaching behaviour as indicative of the contamination degree. Thus, parameters such as slump, density, porosity and absorption of hardened concrete, were studied. Leaching behaviour was evaluated based on the availability test performed to three aggregates (raw materials of the concrete batches) and on the diffusion test performed to all concrete. From an environmental point of view, the question of whether the cumulative amount of heavy metals that are released by diffusion reaches the availability threshold was answered. The analysis of concentration levels allowed the establishment of different groups of metals according to the observed behaviour, the analysis of the role of pH and the identification of the main release mechanisms. Finally, through a statistical analysis, physical parameters and diffusion data were interrelated. It allowed estimating the relevance of porosity, density and absorption of hardened concrete on diffusion release of the metals in study.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. TANK 50 BATCH 0 SALTSTONE FORMULATION CONFIRMATION

    SciTech Connect

    Langton, C.

    2006-06-05

    Savannah River National Laboratory (SRNL) personnel were requested to confirm the Tank 50 Batch 0 grout formulation per Technical Task Request, SSF-TTR-2006-0001 (task 1 of 2) [1]. Earlier Batch 0 formulation testing used a Tank 50 sample collected in September 2005 and is described elsewhere [2]. The current testing was performed using a sample of Tank 50 waste collected in May 2006. This work was performed according to the Technical Task and Quality Assurance Plan (TT/QAP), WSRC-RP-2006-00594 [3]. The salt solution collected from Tank 50 in May 2006 contained approximately 3 weight percent more solids than the sample collected in September 2005. The insoluble solids took longer to settle in the new sample which was interpreted as indicating finer particles in the current sample. The saltstone formulation developed for the September 2005 Tank 50 Batch 0 sample was confirmed for the May 2006 sample with one minor exception. Saltstone prepared with the Tank 50 sample collected in May 2006 required 1.5 times more Daratard 17 set retarding admixture than the saltstone prepared with the September In addition, a sample prepared with lower shear mixing (stirring with a spatula) had a higher plastic viscosity (57 cP) than samples made with higher shear mixing in a blender (23cP). The static gel times of the saltstone slurries made with low shear mixing were also shorter ({approx}32 minutes) than those for comparable samples made in the blender ({approx}47 minutes). The addition of the various waste streams (ETP, HEU-HCAN, and GPE-HCAN) to Tank 50 from September 2005 to May 2006 has increased the amount of set retarder, Daratard 17, required for processing saltstone slurries through the Saltstone facility. If these streams are continued to be added to Tank 50, the quantity of admixtures required to maintain the same processing conditions for the Saltstone facility will probably change and additional testing is recommended to reconfirm the Tank 50 Saltstone formulation.

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

    PubMed

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

    2009-12-01

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

  13. Holographic characterization of protein aggregates

    NASA Astrophysics Data System (ADS)

    Wang, Chen; Zhong, Xiao; Ruffner, David; Stutt, Alexandra; Philips, Laura; Ward, Michael; Grier, David

    Holographic characterization directly measures the size distribution of subvisible protein aggregates in suspension and offers insights into their morphology. Based on holographic video microscopy, this analytical technique records and interprets holograms of individual aggregates in protein solutions as they flow down a microfluidic channel, without requiring labeling or other exceptional sample preparation. The hologram of an individual protein aggregate is analyzed in real time with the Lorenz-Mie theory of light scattering to measure that aggregate's size and optical properties. Detecting, counting and characterizing subvisible aggregates proceeds fast enough for time-resolved studies, and lends itself to tracking trends in protein aggregation arising from changing environmental factors. No other analytical technique provides such a wealth of particle-resolved characterization data in situ. Holographic characterization promises accelerated development of therapeutic protein formulations, improved process control during manufacturing, and streamlined quality assurance during storage and at the point of use. Mrsec and MRI program of the NSF, Spheryx Inc.

  14. Transfer of a three step mAb chromatography process from batch to continuous: Optimizing productivity to minimize consumable requirements.

    PubMed

    Gjoka, Xhorxhi; Gantier, Rene; Schofield, Mark

    2017-01-20

    The goal of this study was to adapt a batch mAb purification chromatography platform for continuous operation. The experiments and rationale used to convert from batch to continuous operation are described. Experimental data was used to design chromatography methods for continuous operation that would exceed the threshold for critical quality attributes and minimize the consumables required as compared to batch mode of operation. Four unit operations comprising of Protein A capture, viral inactivation, flow-through anion exchange (AEX), and mixed-mode cation exchange chromatography (MMCEX) were integrated across two Cadence BioSMB PD multi-column chromatography systems in order to process a 25L volume of harvested cell culture fluid (HCCF) in less than 12h. Transfer from batch to continuous resulted in an increase in productivity of the Protein A step from 13 to 50g/L/h and of the MMCEX step from 10 to 60g/L/h with no impact on the purification process performance in term of contaminant removal (4.5 log reduction of host cell proteins, 50% reduction in soluble product aggregates) and overall chromatography process yield of recovery (75%). The increase in productivity, combined with continuous operation, reduced the resin volume required for Protein A and MMCEX chromatography by more than 95% compared to batch. The volume of AEX membrane required for flow through operation was reduced by 74%. Moreover, the continuous process required 44% less buffer than an equivalent batch process. This significant reduction in consumables enables cost-effective, disposable, single-use manufacturing.

  15. Reactive Scheduling in Multipurpose Batch Plants

    NASA Astrophysics Data System (ADS)

    Narayani, A.; Shaik, Munawar A.

    2010-10-01

    Scheduling is an important operation in process industries for improving resource utilization resulting in direct economic benefits. It has a two-fold objective of fulfilling customer orders within the specified time as well as maximizing the plant profit. Unexpected disturbances such as machine breakdown, arrival of rush orders and cancellation of orders affect the schedule of the plant. Reactive scheduling is generation of a new schedule which has minimum deviation from the original schedule in spite of the occurrence of unexpected events in the plant operation. Recently, Shaik & Floudas (2009) proposed a novel unified model for short-term scheduling of multipurpose batch plants using unit-specific event-based continuous time representation. In this paper, we extend the model of Shaik & Floudas (2009) to handle reactive scheduling.

  16. Optimizing Resource Utilization in Grid Batch Systems

    NASA Astrophysics Data System (ADS)

    Gellrich, Andreas

    2012-12-01

    On Grid sites, the requirements of the computing tasks (jobs) to computing, storage, and network resources differ widely. For instance Monte Carlo production jobs are almost purely CPU-bound, whereas physics analysis jobs demand high data rates. In order to optimize the utilization of the compute node resources, jobs must be distributed intelligently over the nodes. Although the job resource requirements cannot be deduced directly, jobs are mapped to POSIX UID/GID according to the VO, VOMS group and role information contained in the VOMS proxy. The UID/GID then allows to distinguish jobs, if users are using VOMS proxies as planned by the VO management, e.g. ‘role=production’ for Monte Carlo jobs. It is possible to setup and configure batch systems (queuing system and scheduler) at Grid sites based on these considerations although scaling limits were observed with the scheduler MAUI. In tests these limitations could be overcome with a home-made scheduler.

  17. Batch sequential designs for computer experiments

    SciTech Connect

    Moore, Leslie M; Williams, Brian J; Loeppky, Jason L

    2009-01-01

    Computer models simulating a physical process are used in many areas of science. Due to the complex nature of these codes it is often necessary to approximate the code, which is typically done using a Gaussian process. In many situations the number of code runs available to build the Guassian process approximation is limited. When the initial design is small or the underlying response surface is complicated this can lead to poor approximations of the code output. In order to improve the fit of the model, sequential design strategies must be employed. In this paper we introduce two simple distance based metrics that can be used to augment an initial design in a batch sequential manner. In addition we propose a sequential updating strategy to an orthogonal array based Latin hypercube sample. We show via various real and simulated examples that the distance metrics and the extension of the orthogonal array based Latin hypercubes work well in practice.

  18. Reducing variance in batch partitioning measurements

    SciTech Connect

    Mariner, Paul E.

    2010-08-11

    The partitioning experiment is commonly performed with little or no attention to reducing measurement variance. Batch test procedures such as those used to measure K{sub d} values (e.g., ASTM D 4646 and EPA402 -R-99-004A) do not explain how to evaluate measurement uncertainty nor how to minimize measurement variance. In fact, ASTM D 4646 prescribes a sorbent:water ratio that prevents variance minimization. Consequently, the variance of a set of partitioning measurements can be extreme and even absurd. Such data sets, which are commonplace, hamper probabilistic modeling efforts. An error-savvy design requires adjustment of the solution:sorbent ratio so that approximately half of the sorbate partitions to the sorbent. Results of Monte Carlo simulations indicate that this simple step can markedly improve the precision and statistical characterization of partitioning uncertainty.

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

    NASA Astrophysics Data System (ADS)

    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

  20. Permeability of collapsed cakes formed by deposition of fractal aggregates upon membrane filtration.

    PubMed

    Park, Pyung-Kyu; Lee, Chung-Hak; Lee, Sangho

    2006-04-15

    We have investigated, theoretically, the physical properties of cake layers formed from aggregates to obtain a better understanding of membrane systems used in conjunction with coagulation/flocculation pretreatment. We developed a model based on fractal theory and incorporated a cake collapse effect to predict the porosity and permeability of the cake layers. The floc size, fractal dimension, and transmembrane pressure were main parameters that we used in these model calculations. We performed experiments using a batch cell device and a confocal laser-scanning microscope to verify the predicted specific cake resistances and porosities under various conditions. Based on the results of the model, the reduction in inter-aggregate porosity is more important than that in intra-aggregate porosity during the cake collapsing process. The specific cake resistance decreases upon increasing the aggregate size and decreasing the fractal dimensions. The modeled porosities and specific cake resistances of the collapsed cake layer agreed reasonably well with those obtained experimentally.