Science.gov

Sample records for 1-hour ozone maintenance

  1. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  2. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  3. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  4. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  5. 77 FR 64036 - Determination of Attainment of the 1-Hour Ozone National Ambient Air Quality Standards in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-18

    ...EPA is determining that the Sacramento Metro 1-hour ozone nonattainment area (Sacramento Metro Area) has attained the revoked National Ambient Air Quality Standard (1-hour ozone NAAQS or standard), and to exclude certain 2008 data caused by wildfire exceptional events. These air quality determinations were proposed in conjunction with a proposed determination to terminate the State of......

  6. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hour standards are codified in 40 CFR part 81. (c) EPA's authority under paragraph (b) of this section... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level...

  7. 40 CFR 52.975 - Redesignations and maintenance plans; ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...; ozone. 52.975 Section 52.975 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and maintenance plans; ozone. (a) Approval. The Louisiana Department of Environmental Quality (LDEQ... supplemental ozone redesignation requests and revised maintenance plans. These supplemental submittals...

  8. 40 CFR 52.975 - Redesignations and maintenance plans; ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...; ozone. 52.975 Section 52.975 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and maintenance plans; ozone. (a) Approval. The Louisiana Department of Environmental Quality (LDEQ... supplemental ozone redesignation requests and revised maintenance plans. These supplemental submittals...

  9. 40 CFR 52.975 - Redesignations and maintenance plans; ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; ozone. 52.975 Section 52.975 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and maintenance plans; ozone. (a) Approval. The Louisiana Department of Environmental Quality (LDEQ... supplemental ozone redesignation requests and revised maintenance plans. These supplemental submittals...

  10. 40 CFR 52.975 - Redesignations and maintenance plans; ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...; ozone. 52.975 Section 52.975 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and maintenance plans; ozone. (a) Approval. The Louisiana Department of Environmental Quality (LDEQ... supplemental ozone redesignation requests and revised maintenance plans. These supplemental submittals...

  11. 75 FR 10420 - Approval and Promulgation of Implementation Plans: 1-Hour Ozone Extreme Area Plan for San Joaquin...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-08

    ... of Proposed Actions On July 14, 2009 at 74 FR 33933, EPA proposed to approve in part and disapprove...-hour ozone standard). 69 FR 20550 (April 15, 2004). Although we established a new 8-hour ozone standard...\\ See 62 FR 38856 (July 18, 1997). In 2008 we lowered the 8- hour ozone standard to 0.075 ppm. See 73...

  12. 40 CFR 52.975 - Redesignations and maintenance plans; ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; ozone. 52.975 Section 52.975 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and maintenance plans; ozone. Link to an amendment published at 78 FR 27062, May 9, 2013. (a) Approval..., however. The LDEQ addressed these approvability issues in supplemental ozone redesignation requests...

  13. 76 FR 28195 - Approval and Promulgation of Air Quality Implementation Plans; New Mexico; Sunland Park 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... attainment of the 8-hour ozone National Ambient Air Quality Standard (NAAQS) through the year 2014. The... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; New Mexico; Sunland Park 1-Hour Ozone Maintenance Plan AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed...

  14. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  15. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  16. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  17. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  18. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... waiver of the ozone monitoring requirement would be handled under provisions of 40 CFR, part 58. Some... year unless the appropriate Regional Administrator has granted a waiver under the provisions of 40 CFR... and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection...

  19. 77 FR 21512 - Approval, Disapproval and Promulgation of Air Quality Implementation Plan; Utah; Maintenance Plan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... SIP for the 1-hour ozone standard for the Salt Lake County and Davis County nonattainment area (49 FR... Analysis of the Revisions to the Maintenance Plan for the 1-Hour Ozone Standard for Salt Lake County and... ozone, averaged over 1 hour. This new NAAQS replaced the oxidant standard of 0.08 ppm. See 44 FR...

  20. 40 CFR 52.2043 - Control strategy for maintenance plans: ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...: ozone. 52.2043 Section 52.2043 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... Control strategy for maintenance plans: ozone. (a) As of December 26, 2013, EPA approves the following... (VOCs) for the Lancaster 1997 8-Hour Ozone Maintenance Area submitted by the Secretary of...

  1. 75 FR 6570 - Approval and Promulgation of Air Quality Implementation Plans; Louisiana; Baton Rouge 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... and the 1-hour ozone rulemakings cited therein. See 70 FR 71612 (November 29, 2005) and in the cases... its interpretation and practice with respect to the 1-hour ozone standard. See Phase 2 Rule, 70 FR... rulemakings cited in the Phase 2 8-Hour Ozone Implementation Rule, 70 FR 71644-71646 (November 29, 2005)....

  2. 77 FR 35873 - Approval, Disapproval and Promulgation of Air Quality Implementation Plan; Utah; Maintenance Plan...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ... revisions updated the State of Utah's maintenance plan for the 1-hour ozone standard for Salt Lake County... Ozone Standard for Salt Lake County and Davis County III. Response to Comments IV. Final Action V..., averaged over 1 hour. This new NAAQS replaced the oxidant standard of 0.08 ppm. See 44 FR 8202 (February...

  3. 77 FR 34810 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ...EPA is issuing two separate and independent final determinations related to the Baltimore 1-hour ozone nonattainment area. First, EPA is determining that the Baltimore area previously failed to attain the 1-hour ozone National Ambient Air Quality Standard (NAAQS) by its applicable attainment deadline of November 15, 2005 (based on complete, quality-assured and certified ozone monitoring data......

  4. Ozone

    MedlinePlus

    ... Earth's surface. It shields us from the sun's ultraviolet rays. Part of the good ozone layer is ... enough good ozone, people may get too much ultraviolet radiation. This may increase the risk of skin ...

  5. Ozone

    MedlinePlus

    ... reactive form of oxygen. In the upper atmosphere, ozone forms a protective layer that shields us from the sun’s ultraviolet rays. At ground level, ozone is a harmful air pollutant and a primary ...

  6. Ozone

    MedlinePlus

    Ozone is a gas. It can be good or bad, depending on where it is. "Good" ozone occurs naturally about 10 to 30 miles above ... the sun's ultraviolet rays. Part of the good ozone layer is gone. Man-made chemicals have destroyed ...

  7. Ozone

    SciTech Connect

    Not Available

    1988-06-01

    The author discusses the debate over whether concern about a hole in the ozone layer in Antarctic is real or science fiction. There is a growing consensus that efforts must be taken to protect the ozone layer. The issue now is not whether chlorofluorocarbons (CFCs) should be controlled and regulated but how much and how soon. The United States has urged that the production of dangerous CFCs, and any other chemicals that affect the ozone layer, be restricted immediately to current levels and that their use be reduced 95 percent over the next decade. The American position was too strong for many European nations and the Japanese. Negotiations at an international conference on the matter broke down. The breakdown is due in part to a more acute concern for environmental matters in the United States than exists in many countries. Meanwhile CFCs are linked to another environmental problem that equally threatens the world - the Greenhouse Effect. The earth is in a natural warming period, but man could be causing it to become even warmer. The Greenhouse Effect could have a catastrophic impact on mankind, although nothing has been proven yet.

  8. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  9. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  10. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  11. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air... determined that the Baton Rouge 8-hour ozone nonattainment area has attained the 1997 8-hour ozone National Ambient Air Quality Standard (NAAQS). Under the provisions of 40 CFR 51.918 this determination...

  12. 40 CFR 52.977 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Control strategy and regulations: Ozone... and regulations: Ozone. Determination of Attainment. Effective March 12, 2010 EPA has determined the Baton Rouge 1-hour ozone nonattainment area has attained the 1-hour ozone National Ambient Air...

  13. 76 FR 61098 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ...Notice is hereby given that the EPA has posted its draft non- binding guidance titled, ``Guidance for 1-Hour SO2 NAAQS SIP Submissions'' on its Web site. The EPA invites public comments on this guidance document during the comment period specified below, and plans to issue an updated version of the guidance after reviewing timely submitted...

  14. Clean Cities ozone air quality attainment and maintenance strategies that employ alternative fuel vehicles, with special emphasis on natural gas and propane

    SciTech Connect

    Santini, D.J.; Saricks, C.L.

    1998-08-04

    -fueled for gasoline-fueled heavy-duty vehicles. Finally, it raises and expands on the relevance of AFVs and their deployment to some other provisions embedded in EPA`s current guidance for implementing 1-hour NAAQS--standards which currently remain in effect--as tools to provide immediate reductions in ozone, without waiting for promised future clean technologies.

  15. 76 FR 28661 - Interim Final Determination To Defer Sanctions, Sacramento Metro 1-Hour Ozone Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ...,'' ``us'' and ``our'' refer to EPA. I. Background On January 5, 2010 (75 FR 232), we published a finding....S.C. 553(d)(1)). Note that today's action has no impact on the January 5, 2010 (75 FR 232) findings... Executive Order 12866 (58 FR 51735, October 4, 1993), this action is not a ``significant regulatory...

  16. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... National Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 1997 8... requirement to submit a maintenance plan for purposes of paragraph (a)(3)(iii) of this section. 40 CFR part 81.... Control obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by...

  17. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... National Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 1997 8... requirement to submit a maintenance plan for purposes of paragraph (a)(3)(iii) of this section. 40 CFR part 81.... Control obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by...

  18. 40 CFR 52.350 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Ozone. 52.350 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.350 Control strategy: Ozone. (a) Revisions to the Colorado State Implementation Plan, 1-hour ozone NAAQS Redesignation Request and...

  19. 40 CFR 52.350 - Control strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Ozone. 52.350 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.350 Control strategy: Ozone. (a) Revisions to the Colorado State Implementation Plan, 1-hour ozone NAAQS Redesignation Request and...

  20. 40 CFR 52.350 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Ozone. 52.350 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.350 Control strategy: Ozone. (a) Revisions to the Colorado State Implementation Plan, 1-hour ozone NAAQS Redesignation Request and...

  1. 40 CFR 52.350 - Control strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 3 2011-07-01 2011-07-01 false Control strategy: Ozone. 52.350 Section...) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Colorado § 52.350 Control strategy: Ozone. (a) Revisions to the Colorado State Implementation Plan, 1-hour ozone NAAQS Redesignation Request and...

  2. 75 FR 232 - Finding of Failure To Submit Certain State Implementation Plans Required for the 1-Hour Ozone NAAQS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... Area and EPA approved that submission on August 26, 2003, at 68 FR 51184. Therefore, the Sacramento... because it would divert agency resources from the critical substantive review of complete SIPs. See 58 FR 51270, 51272, n.17 (Oct. 1, 1993); 59 FR 39832, 39853 (Aug. 4, 1994). B. Effective Date Under...

  3. 78 FR 37 - Approval and Promulgation of Air Quality Implementation Plans; Utah; Maintenance Plan for the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-02

    .... This new NAAQS replaced the oxidant standard of 0.08 ppm. See 44 FR 8202 (February 8, 1979). Areas... for the 1- hour ozone standard for the Salt Lake County and Davis County nonattainment area (49 FR... found to be attaining the 1-hour ozone standard (60 FR 36723). On July 17, 1997, EPA approved the...

  4. 40 CFR 52.1683 - Control strategy: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... of EPA's ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable... Polystyrene Resins. (b)-(e) (f) Attainment Determination. (1) EPA is determining that the 1-hour...

  5. 40 CFR 52.1683 - Control strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... of EPA's ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable... Polystyrene Resins. (b)-(e) (f) Attainment Determination. (1) EPA is determining that the 1-hour...

  6. 40 CFR 52.1683 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... of EPA's ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable... Polystyrene Resins. (b)-(e) (f) Attainment Determination. (1) EPA is determining that the 1-hour...

  7. Generation and delivery device for ozone gas

    NASA Technical Reports Server (NTRS)

    Andrews, Craig C. (Inventor); Murphy, Oliver J. (Inventor)

    2002-01-01

    The present invention provides an ozone generation and delivery system that lends itself to small scale applications and requires very low maintenance. The system preferably includes an anode reservoir and a cathode phase separator each having a hydrophobic membrane to allow phase separation of produced gases from water. The hydrogen gas, ozone gas and water containing ozone may be delivered under pressure.

  8. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure

    PubMed Central

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2010-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide. Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  9. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  10. 75 FR 47746 - Determination of Nonattainment and Reclassification of the Dallas/Fort Worth 1997 8-hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-09

    ... is more protective than the previous 1-hour ozone standard (62 FR 38855) that was established by EPA in 1979. We revoked the 1-hour ozone standard effective June 15, 2005. See 40 CFR 50.9(b) and 69 FR...). See 69 FR 23857 (April 30, 2004).\\1\\ Ambient air quality monitoring data for the 3-year period...

  11. 77 FR 8197 - Implementation of the 2008 National Ambient Air Quality Standards for Ozone: Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... set at a more stringent level. \\1\\ See 73 FR 16436. \\2\\ The secondary ozone standard, designed to... 1-hour ozone NAAQS, see 56 FR 56694. \\8\\ See 40 CFR Appendix I. \\9\\ Referred to as the Phase 1 Rule... the 1997 ozone NAAQS. (See 69 FR 23954). The Phase 1 rule also established comprehensive...

  12. Generation and delivery device for ozone gas and ozone dissolved in water

    NASA Technical Reports Server (NTRS)

    Andrews, Craig C. (Inventor); Murphy, Oliver J. (Inventor)

    2004-01-01

    The present invention provides an ozone generation and delivery system that lends itself to small scale applications and requires very low maintenance. The system preferably includes an anode reservoir and a cathode phase separator each having a hydrophobic membrane to allow phase separation of produced gases from water. The hydrogen gas, ozone gas and water containing ozone may be delivered under pressure.

  13. Multi-instrument overview of the 1-hour pulsations in Saturn's magnetosphere and auroral emissions (invited)

    NASA Astrophysics Data System (ADS)

    Palmaerts, Benjamin; Roussos, Elias; Radioti, Aikaterini; Krupp, Norbert; Grodent, Denis; Kurth, William S.; Yates, Japheth N.

    2016-04-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes which differ from the rotation period. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 hour in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emission brightness. We made a 10-year survey of the quasi-periodic 1-hour energetic electron injections observed in the Saturn's outer magnetosphere by the Low-Energy Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini. The signature of these injections is pulsations in the electron fluxes at energies between a hundred keV up to several MeV. We investigated the topology and the morphology of these pulsations, as well as the signatures of the electron injections in the radio emissions and the magnetic field, respectively, measured by the Radio and Plasma Wave Science (RPWS) instrument and the magnetometer (MAG) on board Cassini. The morphology of the pulsations (interpulse period, number of pulsations per event, growth and decay time) shows a weak local time dependence, which suggests a high-latitude source for the pulsed energetic electrons. This suggestion is reinforced by the observation of strong radio bursts in the auroral hiss coincident with the electron pulsations and by the higher growth rate and decay rate magnitudes at high latitudes. Moreover, since the morphological properties of the pulsations are similar at the various locations where the electron injections are observed, the acceleration mechanism of the electrons is likely common for all the events and may be directly or indirectly involving magnetic reconnection. The auroral emissions, which display the ionospheric response to magnetospheric dynamics, exhibit some quasi-periodic 1-hour pulsations as well. Some pulsed auroral brightenings are observed while Cassini detects several electron

  14. Setting Spacecraft Maximum Allowable Concentrations for 1 hour or 24 hour contingency exposures to airborne chemicals

    NASA Technical Reports Server (NTRS)

    Garcia, Hector D.; Limero, Thomas F.; James, John T.

    1992-01-01

    Since the early years of the manned space program, NASA has developed and used exposure limits called Spacecraft Maximum Allowable Concentrations (SMACs) to help protect astronauts from airborne toxicants. Most of these SMACS are based on an exposure duration of 7 days, since this is the duration of a 'typical' mission. A set of 'contingency SMACs' is also being developed for scenarios involving brief (1-hour or 24- hour) exposures to relatively high levels of airborne toxicants from event-related 'contingency' releases of contaminants. The emergency nature of contingency exposures dictates the use of different criteria for setting exposure limits. The NASA JSC Toxicology Group recently began a program to document the rationales used to set new SMACs and plans to review the older, 7-day SMACs. In cooperation with the National Research Council's Committee on Toxicology, a standard procedure has been developed for researching, setting, and documenting SMAC values.

  15. Effect of a 1-hour single bout of moderate-intensity exercise on fat oxidation kinetics.

    PubMed

    Chenevière, Xavier; Borrani, Fabio; Ebenegger, Vincent; Gojanovic, Boris; Malatesta, Davide

    2009-12-01

    The present study aimed to examine the effects of a prior 1-hour continuous exercise bout (CONT) at an intensity (Fat(max)) that elicits the maximal fat oxidation (MFO) on the fat oxidation kinetics during a subsequent submaximal incremental test (IncrC). Twenty moderately trained subjects (9 men and 11 women) performed a graded test on a treadmill (Incr), with 3-minute stages and 1-km.h(-1) increments. Fat oxidation was measured using indirect calorimetry and plotted as a function of exercise intensity. A mathematical model (SIN) including 3 independent variables (dilatation, symmetry, and translation) was used to characterize the shape of fat oxidation kinetics and to determine Fat(max) and MFO. On a second visit, the subjects performed CONT at Fat(max) followed by IncrC. After CONT performed at 57% +/- 3% (means +/- SE) maximal oxygen uptake (Vo(2max)), the respiratory exchange ratio during IncrC was lower at every stage compared with Incr (P < .05). Fat(max) (56.4% +/- 2.3% vs 51.5% +/- 2.4% Vo(2max), P = .013), MFO (0.50 +/- 0.03 vs 0.40 +/- 0.03 g.min(-1), P < .001), and fat oxidation rates from 35% to 70% Vo(2max) (P < .05) were significantly greater during IncrC compared with Incr. However, dilatation and translation were not significantly different (P > .05), whereas symmetry tended to be greater in IncrC (P = .096). This study showed that the prior 1-hour continuous moderate-intensity exercise bout increased Fat(max), MFO, and fat oxidation rates over a wide range of intensities during the postexercise incremental test. Moreover, the shape of the postexercise fat oxidation kinetics tended to have a rightward asymmetry. PMID:19632694

  16. Validation of 1-hour post-thyroidectomy parathyroid hormone level in predicting hypocalcemia

    PubMed Central

    2014-01-01

    Background Prior work by our group suggested that a single one hour post-thyroidectomy parathyroid hormone (1 hr PTH) level could accurately stratify patients into high and low risk groups for the development of hypocalcemia. This study looks to validate the safety and efficacy of a protocol based on a 1 hr PTH threshold of 12 pg/ml. Study design Retrospective analysis of consecutive cohort treated with standardized protocol. Methods One hundred and twenty five consecutive patients underwent total or completion thyroidectomy and their PTH level was drawn 1-hour post operatively. Based on our previous work, patients were stratified into either a low risk group (PTH < 12 pg/ml) or a high risk group (PTH ≥ 12 pg/ml). Patients in the high risk group were immediately started on prophylactic calcium carbonate (5–10 g/d) and calcitriol (0.5-1.0 mcg/d). The outcomes were then reviewed focusing mainly on how many low risk patients developed hypocalcemia (false negative rate), and how many high risk patients failed prophylactic therapy. Results Thirty one patients (25%) were stratified as high risk, and 94 (75%) as low risk. Five (16%) of the high risk patients became hypocalcemic despite prophylactic therapy. Two of the low risk group became hypocalcemic, (negative predictive value = 98%). None of the hypocalcemic patients had anything more than mild symptoms. Conclusions A single 1-hour post-thyroidectomy PTH level is a very useful way to stratify thyroidectomy patients into high and low risk groups for development of hypocalcemia. Early implementation of oral prophylactic calcium and vitamin D in the high risk patients is a very effective way to prevent serious hypocalcemia. Complex protocols requiring multiple calcium and PTH measurements are not required to guide post-thyroidectomy management. PMID:24476535

  17. Ozone Treatment For Cooling Towers

    NASA Technical Reports Server (NTRS)

    Blackwelder, Rick; Baldwin, Leroy V.; Feeney, Ellen S.

    1990-01-01

    Report presents results of study of cooling tower in which water treated with ozone instead of usual chemical agents. Bacteria and scale reduced without pollution and at low cost. Operating and maintenance costs with treatment about 30 percent of those of treatment by other chemicals. Corrosion rates no greater than with other chemicals. Advantage of ozone, even though poisonous, quickly detected by smell in very low concentrations.

  18. Mars Ozone Mapping with MAVEN IUVS

    NASA Astrophysics Data System (ADS)

    Lefèvre, F.; Montmessin, F.; Schneider, N. M.; Deighan, J.; Jain, S.; Stewart, I. F.; Stiepen, A.; Chaffin, M.; McClintock, W. E.; Lo, D.; Clarke, J. T.; Holsclaw, G.; Jakosky, B. M.

    2015-12-01

    Ozone (O3) on Mars is a product of the CO2 photolysis by ultraviolet radiation. It is destroyed with a timescale of less than ~1 hour during the day by the H, OH, and HO2 radicals. This tight coupling between O3 and HOx species makes ozone a sensitive tracer of the odd hydrogen chemistry that stabilizes the CO2 atmosphere of Mars, and ozone measurements offer a powerful constraint for photochemical models. Ozone is also expected to be anti-correlated to water vapour, the source of hydrogen radicals HOx. At high latitudes in winter, the absence of H2O prevents the production of HOx and the chemical lifetime of ozone may increase up to several days. In these conditions, the ozone column abundance usually reaches its largest values of the Martian year and ozone turns into a measurable tracer of the polar vortex dynamics. The Imaging Ultraviolet Spectrograph (IUVS) is one of nine science instruments aboard the Mars Atmosphere and Volatile and Evolution (MAVEN) spacecraft. In the apoapse imaging phase, the spacecraft motion carries the IUVS lines-of-sight across the Martian disk while the scan mirror is used to make transverse swaths. This observation mode allows mapping the ozone vertically-integrated column from its signature in the solar ultraviolet flux backscattered by the surface and the atmosphere. This paper will present an overview of the first year of ozone mapping by IUVS. We will describe in particular the last Mars northern winter (2015) when the largest ozone columns have been observed since the beginning of the MAVEN mission. The data will be compared to prior Earth-based observations and to the SPICAM and MARCI ozone datasets. We will also test our quantitative understanding of the Martian ozone by comparing the IUVS observations to our three-dimensional model with photochemistry.

  19. Internal Oblique and Transversus Abdominis Muscle Fatigue Induced by Slumped Sitting Posture after 1 Hour of Sitting in Office Workers

    PubMed Central

    Waongenngarm, Pooriput; Rajaratnam, Bala S.; Janwantanakul, Prawit

    2015-01-01

    Background Prolonged sitting leads to low back discomfort and lumbopelvic muscle fatigue. This study examined the characteristics of body perceived discomfort and trunk muscle fatigue during 1 hour of sitting in three postures in office workers. Methods Thirty workers sat for 1 hour in one of three sitting postures (i.e., upright, slumped, and forward leaning postures). Body discomfort was assessed using the Body Perceived Discomfort scale at the beginning and after 1 hour of sitting. Electromyographic (EMG) signals were recorded from superficial lumbar multifidus, iliocostalis lumborum pars thoracis, internal oblique (IO)/transversus abdominis (TrA), and rectus abdominis muscles during 1 hour of sitting. The median frequency (MDF) of the EMG power spectrum was calculated. Results Regardless of the sitting posture, the Body Perceived Discomfort scores in the neck, shoulder, upper back, low back, and buttock significantly increased after 1 hour of sitting compared with baseline values (t(9) = −11.97 to −2.69, p < 0.05). The MDF value of the EMG signal of rectus abdominis, iliocostalis lumborum pars thoracis, and multifidus muscles was unchanged over time in all three sitting postures. Only the right and left IO/TrA in the slumped sitting posture was significantly associated with decreased MDF over time (p = 0.019 to 0.041). Conclusion Prolonged sitting led to increased body discomfort in the neck, shoulder, upper back, low back, and buttock. No sign of trunk muscle fatigue was detected over 1 hour of sitting in the upright and forward leaning postures. Prolonged slumped sitting may relate to IO/TrA muscle fatigue, which may compromise the stability of the spine, making it susceptible to injury. PMID:27014491

  20. Ozone trends in California`s South Coast Air Basin, 1976--1996

    SciTech Connect

    Cohanim, S.; Cassmassi, J.; Bassett, M.

    1998-12-31

    The South Coast Air Basin (Basin) of Southern California exhibits the worst air quality in the nation, as measured by the annual number of days exceeding the 1-hour National Ambient Air Quality Standard (NAAQS) for ozone. Hourly pollutant concentration data collected by the South Coast Air Quality Management District`s air monitoring network are compared to the existing 1-hour and new 8-hour federal ozone ambient air quality standards to depict ozone trends and compliance in the Basin. Results of trend analyses for the different areas of the Basin are presented for the 1-hour and 8-hour standards, and the relative stringency of the existing and new federal standards is examined. Based on an analysis of the effect of the recently adopted federal standard on ozone compliance in the Basin, ozone concentrations exceed the new federal 8-hour standard level more often than the existing 1-hour standard in most locations. However, examination of the trends in design values for the 1-hour and 8-hour ozone standards suggests that for most locations in the Basin the new standard probably should not be significantly more difficult to attain than the existing standard. The weather-adjusted ozone trend analysis in the Basin confirms the fact that the downtrends in ozone concentrations and number of days exceeding standards are real and independent of annual variation in weather. An analysis of weekday/weekend differences in exceedances for the existing 1-hour and new 8-hour ozone standards show a higher number of days exceeding both standards on weekends for most locations in the Basin, with differences being more evident in the 1990s than in the late 1970s and 1980s

  1. Chlorophyll fluorescence quenching during ozone exposure of leaves of Phaseolus vulgaris (pinto)

    SciTech Connect

    Guralnick, L.J. ); Miller, R.; Heath, R.L. )

    1990-05-01

    During ozone exposure, observations have noted an initial decrease in CO{sub 2} uptake followed by a decrease in stomatal conductance. We examined this response utilizing the technique of fluorescence quenching. Fourteen day old plants were exposed to 0.3 ul/l ozone for 1 hour. Fluorescence quenching was monitored using the Hanstech modulated fluorescence system. This enabled us to measure changes in photochemical quenching (qQ) and non-photochemical quenching (qE) in control and ozone treated plants. Results have indicated no differences in qQ and qE between ozone treated and control plants. We are initiating further studies utilizing different ozone levels.

  2. Polar ozone

    NASA Technical Reports Server (NTRS)

    Solomon, S.; Grose, W. L.; Jones, R. L.; Mccormick, M. P.; Molina, Mario J.; Oneill, A.; Poole, L. R.; Shine, K. P.; Plumb, R. A.; Pope, V.

    1990-01-01

    The observation and interpretation of a large, unexpected ozone depletion over Antarctica has changed the international scientific view of stratospheric chemistry. The observations which show the veracity, seasonal nature, and vertical structure of the Antarctic ozone hole are presented. Evidence for Arctic and midlatitude ozone loss is also discussed. The chemical theory for Antarctic ozone depletion centers around the occurrence of polar stratospheric clouds (PSCs) in Antarctic winter and spring; the climatology and radiative properties of these clouds are presented. Lab studies of the physical properties of PSCs and the chemical processes that subsequently influence ozone depletion are discussed. Observations and interpretation of the chemical composition of the Antarctic stratosphere are described. It is shown that the observed, greatly enhanced abundances of chlorine monoxide in the lower stratosphere are sufficient to explain much if not all of the ozone decrease. The dynamic meteorology of both polar regions is given, interannual and interhemispheric variations in dynamical processes are outlined, and their likely roles in ozone loss are discussed.

  3. Ozone decomposition

    PubMed Central

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho

    2014-01-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  4. Ozone decomposition.

    PubMed

    Batakliev, Todor; Georgiev, Vladimir; Anachkov, Metody; Rakovsky, Slavcho; Zaikov, Gennadi E

    2014-06-01

    Catalytic ozone decomposition is of great significance because ozone is a toxic substance commonly found or generated in human environments (aircraft cabins, offices with photocopiers, laser printers, sterilizers). Considerable work has been done on ozone decomposition reported in the literature. This review provides a comprehensive summary of the literature, concentrating on analysis of the physico-chemical properties, synthesis and catalytic decomposition of ozone. This is supplemented by a review on kinetics and catalyst characterization which ties together the previously reported results. Noble metals and oxides of transition metals have been found to be the most active substances for ozone decomposition. The high price of precious metals stimulated the use of metal oxide catalysts and particularly the catalysts based on manganese oxide. It has been determined that the kinetics of ozone decomposition is of first order importance. A mechanism of the reaction of catalytic ozone decomposition is discussed, based on detailed spectroscopic investigations of the catalytic surface, showing the existence of peroxide and superoxide surface intermediates. PMID:26109880

  5. 40 CFR 52.1683 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... of EPA's ozone implementation rule (see 40 CFR 51.918), this determination suspends the reasonable.... Editorial Note: For Federal Register citations affecting § 52.1683, see the List of CFR Sections Affected... Polystyrene Resins. (b)-(e) (f) Attainment Determination. (1) EPA is determining that the 1-hour...

  6. Ozone variability

    NASA Astrophysics Data System (ADS)

    Duetsch, H. U.

    1983-09-01

    The annual and long-term variations in the atmospheric ozone layer were examined on the basis of 55 yr of data taken at Aroya, Switzerland and 25 yr of data gathered by the global ozone network. Attention was given to annual and biennial variations, which showed that the midlatitude peak concentration was affected by a quasi-biennial variation of the tropical stratospheric circulation. Smaller scale circulation patterns were dominant in the lower stratosphere, although an observed negative trend of the total ozone was equally distributed between the troposphere and 24 km altitude. The global ozone increase detected in the 1960s was possible due to general circulation alterations, but may also have been influenced by injection of NO(x) into the atmosphere during atomic bomb testing.

  7. 1-Hour OGTT Plasma Glucose as a Marker of Progressive Deterioration of Insulin Secretion and Action in Pregnant Women.

    PubMed

    Ghio, Alessandra; Seghieri, Giuseppe; Lencioni, Cristina; Anichini, Roberto; Bertolotto, Alessandra; De Bellis, Alessandra; Resi, Veronica; Lacaria, Emilia; Del Prato, Stefano; Di Cianni, Graziano

    2012-01-01

    Considering old GDM diagnostic criteria, alterations in insulin secretion and action are present in women with GDM as well as in women with one abnormal value (OAV) during OGTT. Our aim is to assess if changes in insulin action and secretion during pregnancy are related to 1-hour plasma glucose concentration during OGTT. We evaluated 3 h/100 g OGTT in 4,053 pregnant women, dividing our population on the basis of 20 mg/dL increment of plasma glucose concentration at 1 h OGTT generating 5 groups (<120 mg/dL, n = 661; 120-139 mg/dL, n = 710; 140-159 mg/dL, n = 912; 160-179 mg/dL, n = 885; and ≥180 mg/dL, n = 996). We calculated incremental area under glucose (AUC(gluc)) and insulin curves (AUC(ins)), indexes of insulin secretion (HOMA-B), and insulin sensitivity (HOMA-R), AUC(ins)/AUC(gluc). AUC(gluc) and AUC(ins) progressively increased according to 1-hour plasma glucose concentrations (both P < 0.0001 for trend). HOMA-B progressively declined (P < 0.001), and HOMA-R progressively increased across the five groups. AUC(ins)/AUC(gluc) decreased in a linear manner across the 5 groups (P < 0.001). Analysing the groups with 1-hour value <180 mg/dL, defects in insulin secretion (HOMA-B: -29.7%) and sensitivity (HOMA-R: +15%) indexes were still apparent (all P < 0.001). Progressive increase in 1-hour OGTT is associated with deterioration of glucose tolerance and alterations in indexes of insulin action and secretion. PMID:22567007

  8. Ozone, Tropospheric

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1995-01-01

    In the early part of the 20th century, ground-based and balloon-borne measurements discovered that most of atmosphere's ozone is located in the stratosphere with highest concentrations located between 15 and 30 km (9,3 and 18.6 miles). For a long time, it was believed that tropospheric ozone originated from the stratosphere and that most of it was destroyed by contact with the earth's surface. Ozone, O3, was known to be produced by the photo-dissociation of molecular oxygen, O2, a process that can only occur at wavelengths shorter than 242 nm. Because such short-wave-length radiation is present only in the stratosphere, no tropospheric ozone production is possible by this mechanism. In the 1940s, however, it became obvious that production of ozone was also taking place in the troposphere. The overall reaction mechanism was eventually identified by Arie Haagen-Smit of the California Institute of Technology, in highly polluted southern California. The copious emissions from the numerous cars driven there as a result of the mass migration to Los Angeles after World War 2 created the new unpleasant phenomenon of photochemical smog, the primary component of which is ozone. These high levels of ozone were injuring vegetable crops, causing women's nylons to run, and generating increasing respiratory and eye-irritation problems for the populace. Our knowledge of tropospheric ozone increased dramatically in the early 1950s as monitoring stations and search centers were established throughout southern California to see what could be done to combat this threat to human health and the environment.

  9. 77 FR 4940 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    ...) (44 FR 8202, February 8, 1979). For ease of communication, we may informally report ozone... FR 8962 at 9001, March ] 3, 1978.\\1\\ Under the 1990 Amendments to the CAA, the CAA designated ``by... final rule (44 FR 8202 at 8220). The control requirements and date by which attainment is to be...

  10. Ozone/Ultraviolet-Photo-Oxidation Reactor

    NASA Technical Reports Server (NTRS)

    Swartz, Ari Ben; Agthe, Richard E.

    1989-01-01

    Experimental chemical-processing system destroys waste hydrazine in water by use of ozone in ultraviolet-photo-oxidation reactor. New process reduces concentrations of hydrazines and intermediate decomposition products in effluent liquid and gas to below limit of detectability. Liquid sprayed in reaction chamber past ultraviolet lamps, against flow of oxygen and ozone. Hydrazines and intermediate decomposition products oxidized to harmless substances. Effectiveness and speed of process depends on maintenance of circulating liquid at correct pH, determines lower limit of oxidation by ozone.

  11. OZONE AND ULTRAVIOLET RADIATION DISINFECTION FOR SMALL COMMUNITY WATER SYSTEMS

    EPA Science Inventory

    Ozone and ultraviolet radiation were used as alternatives to chlorine for disinfection in several small existing community water systems. Both ozone and ultraviolet light were found to be inferior to chlorination from the standpoint of operation and maintenance requirements and m...

  12. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... satisfies 40 CFR 58.20(f) which requires the State to provide for the establishment and maintenance of... area has attaining data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR... 40 Protection of Environment 3 2012-07-01 2012-07-01 false Control strategy: Ozone. 52.582...

  13. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... satisfies 40 CFR 58.20(f) which requires the State to provide for the establishment and maintenance of... area has attaining data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR... 40 Protection of Environment 3 2013-07-01 2013-07-01 false Control strategy: Ozone. 52.582...

  14. 40 CFR 52.582 - Control strategy: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... satisfies 40 CFR 58.20(f) which requires the State to provide for the establishment and maintenance of... area has attaining data for the 1997 8-hour ozone NAAQS. This determination, in accordance with 40 CFR... 40 Protection of Environment 3 2014-07-01 2014-07-01 false Control strategy: Ozone. 52.582...

  15. TROP OZONE

    EPA Science Inventory

    Activity Area (F01) The NRMRL tropospheric ozone research program is both coordinated with the research efforts of others and planned to achieve the most important unmet research needs that draw upon its unique expertise. For example, NRMRL emissions research in this area is co...

  16. 40 CFR 60.2943 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How do I convert my 1-hour arithmetic... SOURCES Operator Training and Qualification Monitoring § 60.2943 How do I convert my 1-hour arithmetic... emissions at 7 percent oxygen. (b) Use Equation 2 in § 60.2975 to calculate the 12-hour rolling averages...

  17. 40 CFR 60.3042 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How do I convert my 1-hour arithmetic... Construction On or Before December 9, 2004 Model Rule-Monitoring § 60.3042 How do I convert my 1-hour... calculate emissions at 7 percent oxygen. (b) Use Equation 2 in § 60.3076 to calculate the 12-hour...

  18. The Antarctic Ozone Hole

    ERIC Educational Resources Information Center

    Jones, Anna E.

    2008-01-01

    Since the mid 1970s, the ozone layer over Antarctica has experienced massive destruction during every spring. In this article, we will consider the atmosphere, and what ozone and the ozone layer actually are. We explore the chemistry responsible for the ozone destruction, and learn about why conditions favour ozone destruction over Antarctica. For…

  19. Ozone and aircraft operations

    NASA Technical Reports Server (NTRS)

    Perkins, P. J.

    1981-01-01

    The cabin ozone problem is discussed. Cabin ozone in terms of health effects, the characteristics of ozone encounters by aircraft, a brief history of studies to define the problem, corrective actions taken, and possible future courses of action are examined. It is suggested that such actions include avoiding high ozone concentrations by applying ozone forecasting in flight planning procedures.

  20. Earth's Endangered Ozone

    ERIC Educational Resources Information Center

    Panofsky, Hans A.

    1978-01-01

    Included are (1) a discussion of ozone chemistry; (2) the effects of nitrogen fertilizers, fluorocarbons, and high level aircraft on the ozone layer; and (3) the possible results of a decreasing ozone layer. (MR)

  1. Ozone crisis

    SciTech Connect

    Roan, S.

    1989-01-01

    The author presents an account of the depletion of the atmosphere's ozone layer since the discovery of the phenomenon 15 years ago. The book recounts the flight to ban chlorofluorocarbons (CFC's) and describes the science, the people, and the politics involved, up to the March 1988 international treaty restricting CFC production. It surveys the media's coverage, describes the struggle for remedies, and offers a prognosis for the future.

  2. Generation and delivery device for ozone gas and ozone dissolved in water

    NASA Technical Reports Server (NTRS)

    Andrews, Craig C. (Inventor); Rogers, Thomas D. (Inventor); Murphy, Oliver J. (Inventor)

    1999-01-01

    The present invention provides an ozone generation and delivery system that lends itself to small scale applications and requires very low maintenance. The system includes an anode reservoir and a cathode phase separator each having a hydrophobic membrane to allow phase separation of produced gases from water. The system may be configured to operate passively with no moving parts or in a self-pressurizing manner with the inclusion of a pressure controlling device or valve in the gas outlet of the anode reservoir. The hydrogen gas, ozone gas and water containing ozone may be delivered under pressure.

  3. Generation and delivery device for ozone gas and ozone dissolved in water

    NASA Technical Reports Server (NTRS)

    Andrews, Craig C. (Inventor); Murphy, Oliver J. (Inventor)

    2006-01-01

    The present invention provides an ozone generation and delivery system that lends itself to small scale applications and requires very low maintenance. The system includes an anode reservoir and a cathode phase separator each having a hydrophobic membrane to allow phase separation of produced gases from water. The system may be configured to operate passively with no moving parts or in a self-pressurizing manner with the inclusion of a pressure controlling device or valve in the gas outlet of the anode reservoir. The hydrogen gas, ozone gas and water containing ozone may be delivered under pressure.

  4. Statistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in Saturn's outer magnetosphere

    NASA Astrophysics Data System (ADS)

    Palmaerts, B.; Roussos, E.; Krupp, N.; Kurth, W. S.; Mitchell, D. G.; Dougherty, M. K.

    2015-10-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 hour in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emissions brightness. The Low- Energy Magnetospheric Measurement System detector of the Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini regularly detects 1-hour quasi-periodic enhancements in the intensities of electrons with an energy range from a hundred keV to several MeV. We extend an earlier survey of these relativistic electron injections, using 10 years of LEMMS observations in addition to context measurements by several other Cassini magnetospheric experiments. During this period, we identified 720 pulsed events in the outer magnetosphere over a wide range of latitudes and local times, revealing that this phenomenon is common and frequent in Saturn's magnetosphere. However, the distribution of the injection events presents a strong local time asymmetry with ten times more events in the duskside than in the dawnside. In addition to the study of their topology, we present a first statistical analysis of these pulsed events to investigate their properties. This analysis reveals that the mean interpulse period is 68 ± 10 minutes and that the events are made up of less than 9 pulses in general, but they can include up to 19 pulses. The most common shape of these pulses is a fast rise followed by a slow decay. Moreover, the ratio between the rise rate and the decay rate increases with the energy. We have also investigated the signatures of each electron injection event in the observations acquired by the Radio and Plasma Wave Science (RPWS) instrument and the magnetometer (MAG). Correlated pulsed signatures are observed in the plasma wave emissions, especially in the auroral hiss, for 12% of the

  5. Maintenance Budgeting.

    ERIC Educational Resources Information Center

    Smith, J. McCree

    Three methods for the preparation of maintenance budgets are discussed--(1) a traditional method, inconclusive and obsolete, based on gross square footage, (2) the formula approach method based on building classification (wood-frame, masonry-wood, masonry-concrete) with maintenance cost factors for each type plus custodial service rates by type of…

  6. Preventative Maintenance.

    ERIC Educational Resources Information Center

    Migliorino, James

    Boards of education must be convinced that spending money up front for preventive maintenance will, in the long run, save districts' tax dollars. A good program of preventive maintenance can minimize disruption of service; reduce repair costs, energy consumption, and overtime; improve labor productivity and system equipment reliability; handle…

  7. Software Maintenance.

    ERIC Educational Resources Information Center

    Cannon, Glenn; Jobe, Holly

    Proper cleaning and storage of audiovisual aids is outlined in this brief guide. Materials and equipment needed for first line maintenance are listed, as well as maintenance procedures for records, audio and video tape, film, filmstrips, slides, realia, models, prints, graphics, maps, and overhead transparencies. A 15-item quiz on software…

  8. Maintenance Downtime

    Atmospheric Science Data Center

    2013-07-10

    ... will be unavailable March 5, 2013 8:00 am to 5:00 pm due to database maintenance. Date(s):  Tuesday, March 5, 2013 ... will be unavailable March 5, 2013 8:00 am to 5:00 pm due to database maintenance. ...

  9. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis

    2015-01-01

    Using satellite-based methods that provide accurate 0-1 hour convective initiation (CI) nowcasts, and rely on proven success coupling satellite and radar fields in the Corridor Integrated Weather System (CIWS; operated and developed at MIT-Lincoln Laboratory), to subsequently monitor for first-flash lightning initiation (LI) and later period lightning trends as storms evolve. Enhance IR-based methods within the GOES-R CI Algorithm (that must meet specific thresholds for a given cumulus cloud before the cloud is considered to have an increased likelihood of producing lightning next 90 min) that forecast LI. Integrate GOES-R CI and LI fields with radar thresholds (e.g., first greater than or equal to 40 dBZ echo at the -10 C altitude) and NWP model data within the WDSS-II system for LI-events from new convective storms. Track ongoing lightning using Lightning Mapping Array (LMA) and pseudo-Geostationary Lightning Mapper (GLM) data to assess per-storm lightning trends (e.g., as tied to lightning jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "lightning threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.

  10. Engineering considerations for the economic design, installation and operation of ozonation equipment for cooling water treatment

    SciTech Connect

    Rice, R.G.

    1994-12-31

    Once it has been decided to install ozone for the treatment of cooling water, the next step is to assure that the equipment is sized and designed for the most reliable and economical operation. Design principles are presented which have proved to be effective for ozonation systems which have been treating municipal water and wastewaters so as to maximize the reliability of equipment performance, constancy of ozone output in a fail-safe mode, minimizing power expenditures, while providing for preventive maintenance. For example, rather than purchase a single ozone generator with a second for standby, the purchaser of ozone equipment might install three ozone generators, each of which is capable of producing 50% of the required quantity of ozone. Two of these are on-line continuously, with the third off-line, allowing for planned maintenance downtime. For periods of unusually high ozone demand, on-site liquid oxygen can be made available to double the output of ozone over that available from dried air. Advantages of generating ozone from oxygen will be discussed, and finally, a novel Japanese method of generating ozone from high purity oxygen, adsorption of ozone onto silica gel or molecular sieves, recycling of the oxygen, and intermittent application of the adsorbed ozone to flowing cooling water will be described.

  11. Ozone Hole Over Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These images from the Total Ozone Mapping Spectrometer (TOMS) show the progressive depletion of ozone over Antarctica from 1979 to 1999. This 'ozone hole' has extended to cover an area as large as 10.5 million square miles in September 1998. The previous record of 10.0 million square miles was set in 1996. The Antarctic ozone hole develops each year between late August and early October. Regions with higher levels of ozone are shown in red. NASA and NOAA instruments have been measuring Antarctic ozone levels since the early 1970s. Large regions of depleted ozone began to develop over Antarctica in the early 1980s. Ozone holes of substantial size and depth are likely to continue to form during the next few years, scientists hope to see a reduction in ozone loss as levels of ozone-destroying CFCs (chlorofluorocarbons) are gradually reduced. Credit: Images by Greg Shirah, NASA Goddard Space Flight Center Scientific Visualization Studio

  12. GOES Infrared and Reflectance 0-1 hour Lightning Initiation Indicators: Development and Initial Testing within a Convective Nowcasting System

    NASA Astrophysics Data System (ADS)

    Mecikalski, J. R.; Harris, R.; MacKenzie, W.; Durkee, P. A.; Iskenderian, H.; Bickmeier, L.; Nielsen, K. E.

    2010-12-01

    Within cumulus cloud fields that develop in conditionally unstable air masses, only a fraction of the cumuli may eventually develop into deep convection. Identifying which of these convective clouds most likely to generate lightning often starts with little more than a qualitative visual satellite analysis. The goal of this study is to identify the observed satellite infrared (IR) signatures associated with growing cumulus clouds prior to the first lightning strike, so-called lightning initiation (LI). This study quantifies the behavior of ten Geostationary Operational Environmental Satellite (GOES-12) IR interest fields in the 1-hour in advance of LI. A total of 172 lightning-producing storms that occurred during the 2009 convective season are manually tracked and studied over four regions: Northern Alabama, Central Oklahoma, the Kennedy Space Center and Washington D.C. Four-dimensional and cloud-to-ground lightning array data provide a total cloud lightning picture (in-cloud, cloud-to-cloud, cloud-to-air, cloud-to-ground) and thus precise LI points for each storm in both time and space. Statistical significance tests are conducted on observed trends for each of the ten LI fields to determine the unique information each field provides in terms of behavior prior to LI. Eight out of ten LI fields exhibited useful information at least 15 min in advance of LI, with 35 min being the average. Statistical tests on these eight fields are compared for separate large geographical areas. IR temperature thresholds are then determined as an outcome, which may be valuable when implementing a LI prediction algorithm into real-time satellite-based systems. The key LI indicators from GOES IR data (as well as 3.9 μm reflectance) will be presented. Beginning in 2010, the feasibility of using the satellite-based LI indicators found in the above analysis to forecast first lightning will be assessed within the Federal Aviation Administration’s (FAA) CoSPA nowcasting system. The goal

  13. Statistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in Saturn's outer magnetosphere

    NASA Astrophysics Data System (ADS)

    Palmaerts, B.; Roussos, E.; Krupp, N.; Kurth, W. S.; Mitchell, D. G.; Yates, J. N.

    2016-06-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 h in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emissions brightness. The Low-Energy Magnetospheric Measurement System detector of the Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini regularly detects 1-hour quasi-periodic enhancements in the intensities of electrons with an energy range from a hundred keV to several MeV. We extend an earlier survey of these relativistic electron injections using 10 years of LEMMS observations in addition to context measurements by several other Cassini magnetospheric experiments. The one-year extension of the data and a different method of detection of the injections do not lead to a discrepancy with the results of the previous survey, indicating an absence of a long-term temporal evolution of this phenomenon. We identified 720 pulsed events in the outer magnetosphere over a wide range of latitudes and local times, revealing that this phenomenon is common and frequent in Saturn's magnetosphere. However, the distribution of the injection events presents a strong local time asymmetry with ten times more events in the duskside than in the dawnside. In addition to the study of their topology, we present a first statistical analysis of the pulsed events properties. The morphology of the pulsations shows a weak local time dependence which could imply a high-latitude acceleration source. We provide some clues that the electron population associated with this pulsed phenomenon is distinct from the field-aligned electron beams previously observed in Saturn's magnetosphere, but both populations can be mixed. We have also investigated the signatures of each electron injection event in the observations acquired by the Radio

  14. 78 FR 65877 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-04

    ... Georgia's ROP plan for the 1-hour ozone NAAQS for the Atlanta Area on April 26, 1999. See 64 FR 20196. \\3..., Paulding, and Rockdale. See 56 FR 56694, November 6, 1991. \\4\\ Seven additional ``ring'' counties were.... These additional counties are: Barrow, Bartow, Carroll, Hall, Newton, Spalding, and Walton. See 69...

  15. 78 FR 32135 - Approval and Promulgation of Implementation Plans; Atlanta, Georgia 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... the 1-hour ozone NAAQS for the Atlanta Area on April 26, 1999. See 64 FR 20196. \\3\\ The 13-County.... See 56 FR 56694, November 6, 1991. \\4\\ Seven additional ``ring'' counties were added to the original 1... counties include: Barrow, Bartow, Carroll, Hall, Newton, Spalding, and Walton. See 69 FR 23857, April...

  16. 40 CFR 52.2037 - Control strategy plans for attainment and rate-of-progress: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... area for so long as the area does not monitor any violations of the 1-hour ozone standard of 40 CFR 50... 19, 2008. (q) Determination of attainment—In accordance with 40 CFR 51.918, EPA has determined that... accordance with 40 CFR 51.918, suspends the requirements for this area to submit an attainment...

  17. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey

    2015-01-01

    Lightning one of the most dangerous weather-related phenomena, especially as many jobs and activities occur outdoors, presenting risk from a lightning strike. Cloud-to-ground (CG) lightning represents a considerable safety threat to people at airfields, marinas, and outdoor facilities-from airfield personnel, to people attending outdoor stadium events, on beaches and golf courses, to mariners, as well as emergency personnel. Holle et al. (2005) show that 90% of lightning deaths occurred outdoors, while 10% occurred indoors despite the perception of safety when inside buildings. Curran et al. (2000) found that nearly half of fatalities due to weather were related to convective weather in the 1992-1994 timeframe, with lightning causing a large component of the fatalities, in addition to tornadoes and flash flooding. Related to the aviation industry, CG lightning represents a considerable hazard to baggage-handlers, aircraft refuelers, food caterers, and emergency personnel, who all become exposed to the risk of being struck within short time periods while convective storm clouds develop. Airport safety protocols require that ramp operations be modified or discontinued when lightning is in the vicinity (typically 16 km), which becomes very costly and disruptive to flight operations. Therefore, much focus has been paid to nowcasting the first-time initiation and extent of lightning, both of CG and of any lightning (e.g, in-cloud, cloud-to-cloud). For this project three lightning nowcasting methodologies will be combined: (1) a GOESbased 0-1 hour lightning initiation (LI) product (Harris et al. 2010; Iskenderian et al. 2012), (2) a High Resolution Rapid Refresh (HRRR) lightning probability and forecasted lightning flash density product, such that a quantitative amount of lightning (QL) can be assigned to a location of expected LI, and (3) an algorithm that relates Pseudo-GLM data (Stano et al. 2012, 2014) to the so-called "lightning jump" (LJ) methodology (Shultz et al

  18. Antarctic Ozone Hole, 2000

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Each spring the ozone layer over Antarctica nearly disappears, forming a 'hole' over the entire continent. The hole is created by the interaction of some man-made chemicals-freon, for example-with Antarctica's unique weather patterns and extremely cold temperatures. Ozone in the stratosphere absorbs ultraviolet radiation from the sun, thereby protecting living things. Since the ozone hole was discovered many of the chemicals that destroy ozone have been banned, but they will remain in the atmosphere for decades. In 2000, the ozone hole grew quicker than usual and exceptionally large. By the first week in September the hole was the largest ever-11.4 million square miles. The top image shows the average total column ozone values over Antarctica for September 2000. (Total column ozone is the amount of ozone from the ground to the top of the atmosphere. A relatively typical measurement of 300 Dobson Units is equivalent to a layer of ozone 0.12 inches thick on the Earth's surface. Levels below 220 Dobson Units are considered to be significant ozone depletion.) The record-breaking hole is likely the result of lower than average ozone levels during the Antarctic fall and winter, and exceptionally cold temperatures. In October, however (bottom image), the hole shrank dramatically, much more quickly than usual. By the end of October, the hole was only one-third of it's previous size. In a typical year, the ozone hole does not collapse until the end of November. NASA scientists were surprised by this early shrinking and speculate it is related to the region's weather. Global ozone levels are measured by the Total Ozone Mapping Spectrometer (TOMS). For more information about ozone, read the Earth Observatory's ozone fact sheet, view global ozone data and see these ozone images. Images by Greg Shirah, NASA GSFC Scientific Visualization Studio.

  19. [Effect of coal tar on cignolin erythema--1 hour treatment of psoriasis with high-dose cignolin with and without tar].

    PubMed

    Schauder, S; Mahrle, G

    1985-06-01

    Coal tar applied simultaneously showed a suppressive effect on anthralin erythema. This effect was demonstrated by an epicutaneous test 24 hours (27 patients) and 1 hour (46 patients) after application of various concentrations of anthralin combined with tar 3%. In a clinical study on 9 patients, anthralin 3% alone or combined with tar 10% were administered in a right and left comparison on symmetrical chronic psoriatic lesions for 1 hour daily. Anthralin plus tar exhibited a stronger anti-psoriatic effect than anthralin alone did. Tar reduced the anthralin erythema in the perilesional skin. These findings favor the combination of coal tar and anthralin in the 1-hour treatment schedule of psoriasis. PMID:3160177

  20. Privatizing Maintenance.

    ERIC Educational Resources Information Center

    Hounsell, Dan

    1996-01-01

    Schools and other government facilities want to see whether privatization of maintenance can provide services as efficiently and at less cost than inhouse workers. Privatization proponents say that everyone will benefit the most if the bidding process involves competition. Offers examples from the Memphis City Schools and the Union Public Schools…

  1. Ozone in the free atmosphere

    NASA Technical Reports Server (NTRS)

    Whitten, R. C. (Editor); Prasad, S. S. (Editor)

    1985-01-01

    The present book provides a summary of the state of scientific knowledge of stratospheric and free tropospheric ozone as it exists at the beginning of 1983. Ozone photochemistry in the stratosphere is discussed, taking into account fundamental molecular properties, the absorption spectrum of ozone, photodissociation, ozone formation and destruction in the upper atmosphere, the photochemistry of odd-hydrogen, the photochemistry of odd-nitrogen, the photochemistry of odd-chlorine, and photochemistry-temperature coupling. The observed distribution of atmospheric ozone and its variations are considered along with ozone transport, ozone in the troposphere, stratospheric ozone perturbations, and climatic and biological effects. Attention is given to the techniques of observing atmospheric ozone, horizontal-vertical ozone transport and conservative quantities, measurements of tropospheric ozone, the tropospheric ozone budget, ozone models, natural ozone variations, and anthropogenic ozone perturbations.

  2. Ozone Trend Detectability

    NASA Technical Reports Server (NTRS)

    Campbell, J. W. (Editor)

    1981-01-01

    The detection of anthropogenic disturbances in the Earth's ozone layer was studied. Two topics were addressed: (1) the level at which a trend in total ozoning is detected by existing data sources; and (2) empirical evidence in the prediction of the depletion in total ozone. Error sources are identified. The predictability of climatological series, whether empirical models can be trusted, and how errors in the Dobson total ozone data impact trend detectability, are discussed.

  3. Ozone Layer Observations

    NASA Technical Reports Server (NTRS)

    McPeters, Richard; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    The US National Aeronautics and Space Administration (NASA) has been monitoring the ozone layer from space using optical remote sensing techniques since 1970. With concern over catalytic destruction of ozone (mid-1970s) and the development of the Antarctic ozone hole (mid-1980s), long term ozone monitoring has become the primary focus of NASA's series of ozone measuring instruments. A series of TOMS (Total Ozone Mapping Spectrometer) and SBUV (Solar Backscatter Ultraviolet) instruments has produced a nearly continuous record of global ozone from 1979 to the present. These instruments infer ozone by measuring sunlight backscattered from the atmosphere in the ultraviolet through differential absorption. These measurements have documented a 15 Dobson Unit drop in global average ozone since 1980, and the declines in ozone in the antarctic each October have been far more dramatic. Instruments that measure the ozone vertical distribution, the SBUV and SAGE (Stratospheric Aerosol and Gas Experiment) instruments for example, show that the largest changes are occurring in the lower stratosphere and upper troposphere. The goal of ozone measurement in the next decades will be to document the predicted recovery of the ozone layer as CFC (chlorofluorocarbon) levels decline. This will require a continuation of global measurements of total column ozone on a global basis, but using data from successor instruments to TOMS. Hyperspectral instruments capable of measuring in the UV will be needed for this purpose. Establishing the relative roles of chemistry and dynamics will require instruments to measure ozone in the troposphere and in the stratosphere with good vertical resolution. Instruments that can measure other chemicals important to ozone formation and destruction will also be needed.

  4. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS...)(3)(iii) of this section. 40 CFR part 81, subpart C identifies the boundaries of areas and the area... obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the State only...

  5. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS...)(3)(iii) of this section. 40 CFR part 81, subpart C identifies the boundaries of areas and the area... obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the State only...

  6. 2001 OZONE DESIGN VALUE

    EPA Science Inventory

    Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the atmosphere when air is stagnant and temperatures are high to form ozone. Ozone is known to cause adverse health eff...

  7. 2020 OZONE DESIGN VALUE

    EPA Science Inventory

    Ozone is generated by a complex atmoshperic chemical process. Industrial and automobile pollutants in the form of oxides of nitrogen and hydrocarbons react in the atmosphere when air is stagnant and temperatures are high to form ozone. Ozone is known to cause adverse health eff...

  8. OZONE BYPRODUCT FORMATION

    EPA Science Inventory

    The use of ozone for water treatment has been increasing as ozone has great potential for degrading water pollutants and inactivating viruses, Giardia cysts, and Cryptosporidium oocysts. Although it appears that ozone generates less undesirable disinfection by-products (DBPs) th...

  9. Ozone Antimicrobial Efficacy

    EPA Science Inventory

    Ozone is a potent germicide that has been used extensively for water purification. In Europe, 90 percent of the municipal water systems are treated with ozone, and in France, ozone has been used to treat drinking water since 1903. However, there is limited information on the bioc...

  10. The origin of ozone

    NASA Astrophysics Data System (ADS)

    Grewe, V.

    2006-05-01

    Highest atmospheric ozone production rates can be found at around 30 km in the tropical stratosphere, leading to ozone mixing ratios of about 10 ppmv. Those stratospheric air masses are then transported to extra-tropical latitudes via the Brewer-Dobson circulation. This is considered the main mechanism to generate mid- and high latitude ozone. By applying the climate-chemistry models E39/C and MAECHAM4/CHEM, this view is investigated in more detail. The origin of ozone in the troposphere and stratosphere is analysed, by incorporating a diagnostics ("marked ozone origin tracers") into the models, which allows to identify the origin of ozone. In most regions the simulated local ozone concentration is dominated by local ozone production, i.e. less than 50% of the ozone at higher latitudes of the stratosphere is produced in the tropics, which conflicts with the idea that the tropics are the global source for stratospheric ozone. Although episodic stratospheric intrusions occur basically everywhere, the main ozone stratosphere-to-troposphere exchange is connected to exchange processes at the sub-tropical jet-stream. The simulated tropospheric influx of ozone amounts to 420 Tg per year, and originates in the Northern Hemisphere from the extra-tropical stratosphere, whereas in the Southern Hemisphere a re-circulation of tropical tropospheric ozone contributes most to the influx of ozone into the troposphere. In the model E39/C, the upper troposphere of both hemispheres is clearly dominated by tropical tropospheric ozone (40%-50%) except for northern summer hemisphere, where the tropospheric contribution (from the tropics as well as from the Northern Hemisphere) does not exceed 20%.

  11. Periodontal maintenance.

    PubMed

    Tan, A E S

    2009-09-01

    The main goal of periodontal therapy is to establish an oral environment compatible with periodontal health by the physical disruption of the plaque biofilm and adjunctive chemical means if required. Implicit in this objective is the ongoing requirement of detection and interception of new and recurrent disease, which continues at selected intervals for the life of the dentition after the initial ("active") phase of periodontal treatment. This concept of ongoing periodontal maintenance therapy has been embraced as the mandatory requirement for favourable periodontal outcomes based on institutional clinical trials and in practice-based studies in various parts of the world. This review examines the ramifications of periodontal maintenance therapy based upon a multi-level assessment of logistic issues and risk factors at three levels: (1) The patient level - treatment time; patient attendance compliance; and homecare measures, antiseptics/antibiotics and smoking. (2) The level of the individual tooth - tooth loss; and evaluation of success versus survival. (3) The level of each tooth surface ("site") - probing depth, loss of attachment and bleeding on probing; and changes in clinical attachment levels. In spite of the diversity of studies conducted, there is agreement on the efficacy of periodontal maintenance therapy when compared with studies on untreated populations and in treated cases that were not maintained. PMID:19737263

  12. Ifluence of outer electrode material on ozone production in coaxial negative corona discharge fed by oxygen

    NASA Astrophysics Data System (ADS)

    Orszagh, J.; Skalny, J. D.; Mason, N. J.

    2008-07-01

    The "electric odour", observed by Van Marum when oxygen was passing trough electric spark in 1785, has been later (1839), identified by Ch. F. Schonbeim as a new chemical compound named ozone (Stolarski 1999). Almost from those times ozone is widely used chemical compound. The effect of outer electrode material on the ozone production in negative corona discharge have been studied. Two electrodes with the same dimensions were used in the experiment. One was made of stainless steel other one of brass. First the outer electrode was mechanically cleaned to remove the layer of oxides. The reactor have been filled by pure oxygen and closed. Then the measurement (1 hour measurement of discharge current at the constant voltage and time dependence of ozone concentration in the reactor) was repeated 5 times without cleaning the surface to see the ageing effects. Especially the influence of electrode oxidation on ozone concentration was studied. The experiments have been carried out at atmospheric pressure and ambient temperature. The ozone concentration was measured by UV spectroscopy method directly in the discharge reactor. As one can expect the brass surface was oxidizing faster. After five measurements the electrode surface was covered by layer of greenish oxides. On the other hand the steel electrode surface had no visible oxides layer. The oxidation of the outer electrode had little systematic effect on the ozone concentration but in case of brass electrode the results were scattered in the range from 8000 ppm to 15000 ppm of ozone. It seems that the more oxides are created on the surface the less ozone is produced or the faster the ozone decomposition processes are (see Fig. 1). On the other hand in case of stainless steel electrode the ozone concentrations were comparable in all 5 measurements. Overall ozone concentration was higher in steel electrode. Figure 1: Time dependence of ozone concentration.

  13. Overview of ozone bleaching

    SciTech Connect

    Sonnenberg, L.B.

    1995-12-31

    The potential impact of the pulp and paper industry on the environment may be reduced by replacing chlorine-based bleaching reagents with ozone. The reactivity of ozone coupled with the heterogeneity of pulp allows many types of reactions to occur during pulp bleaching. Ozone cleaves the aromatic rings and side chain double bonds in lignin in Criegee-type mechanisms. Activated carbon-hydrogen bonds are fragmented in lignin side chains, as well as Cl carbons of {beta}-glycosides, by way of a 1,3 dipolar insertion forming a hydrotrioxide intermediate. Ozone also attacks carbohydrates at acetal oxygens, depolymerizing at the glycosidic bond. Unsaturated sites are ozonated before aliphatic sites resulting in a predominance of lignin reactions over carbohydrate reactions until lignin is substantially removed from the pulp. Important factors in the successful application of ozone bleaching include minimizing ozone decomposition and other secondary reactions, reducing exposure of cellulose to high concentrations of ozone and radicals, and promoting uniform exposure of ozone to lignin. The quantity of chlorinated organic compounds in effluents can be drastically reduced by replacing chlorine-based bleaching reagents with ozone; less organochlorine is formed and there can be greater recycle of bleach plant wastes back to the recovery cycle. Recycling of bleach plant waste also reduces total organic loading in the effluent. The toxicity of ozone filtrates is variable compared to conventional filtrates and depends on several parameters including bleaching conditions, biological treatment, and target organisms.

  14. Approval and promulgation of Michigan State Implementation Plan (SIP). carbon monoxide and ozone

    SciTech Connect

    Not Available

    1980-06-02

    These two US Environmental Protection Agency notices approve the revised Michigan SIP for ozone control strategy for the Flint, Lansing, Grand Rapids, and other rural nonattainment areas; ozone, carbon monoxide control, and vehicle inspection/maintenance programs fr the Detroit urban areas; and transportation control plans for all these areas. These final rules are effective as of 5/23/80.

  15. Ozone and the stratosphere

    NASA Technical Reports Server (NTRS)

    Shimazaki, Tatsuo

    1987-01-01

    It is shown that the stratospheric ozone is effective in absorbing almost all radiation below 300 nm at heights below 300 km. The distribution of global ozone in the troposphere and the lower stratosphere, and the latitudinal variations of the total ozone column over four seasons are considered. The theory of the ozone layer production is discussed together with catalytic reactions for ozone loss and the mechanisms of ozone transport. Special attention is given to the anthropogenic perturbations, such as SST exhaust gases and freon gas from aerosol cans and refrigerators, that may cause an extensive destruction of the stratospheric ozone layer and thus have a profound impact on the world climate and on life.

  16. Spring polar ozone behavior

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1992-01-01

    Understanding of the springtime behavior of polar stratospheric ozone as of mid 1990 is summarized. Heterogeneous reactions on polar stratospheric clouds as hypothesis for ozone loss are considered and a simplified description of the behavior of Antarctic ozone in winter and spring is given. Evidence that the situation is more complicated than described by the theory is produced. Many unresolved scientific issues remain and some of the most important problems are identified. Ozone changes each spring since 1979 have clearly established for the first time that man made chlorine compounds influence stratospheric ozone. Long before important advances in satellite and in situ investigations, it was Dobson's decision to place a total ozone measuring spectrometer at Halley Bay in Antarctica during the International Geophysical Year and subsequent continuous monitoring which led to the discovery that ozone was being destroyed each spring by chlorine processed by polar stratospheric clouds.

  17. New Directions: Ozone-initiated reaction products indoors may be more harmful than ozone itself

    NASA Astrophysics Data System (ADS)

    Weschler, Charles J.

    2004-10-01

    Epidemiological studies have found associations between ozone concentrations measured at outdoor monitoring stations and certain adverse health outcomes. As a recent example, Gent et al. (2003, Journal of the American Medical Association 290, 1859-1867) have observed an association between ozone levels and respiratory symptoms as well as the use of maintenance medication by 271 asthmatic children living in Connecticut and the Springfield area of Massachusetts. In another example, Gilliland et al. (2001, Epidemiology 12, 43-54) detected an association between short-term increases in ozone levels and increased absences among 4th grade students from 12 southern California communities during the period from January to June 1996. Although children may spend a significant amount of time outdoors, especially during periods when ozone levels are elevated, they spend a much larger fraction of their time indoors. I hypothesize that exposure to the products of ozone-initiated indoor chemistry is more directly responsible for the health effects observed in the cited epidemiological studies than is exposure to outdoor ozone itself.

  18. Probabilistic aspects of meteorological and ozone regional ensemble forecasts

    SciTech Connect

    Monache, L D; Hacker, J; Zhou, Y; Deng, X; Stull, R

    2006-03-20

    This study investigates whether probabilistic ozone forecasts from an ensemble can be made with skill; i.e., high verification resolution and reliability. Twenty-eight ozone forecasts were generated over the Lower Fraser Valley, British Columbia, Canada, for the 5-day period 11-15 August 2004, and compared with 1-hour averaged measurements of ozone concentrations at five stations. The forecasts were obtained by driving the CMAQ model with four meteorological forecasts and seven emission scenarios: a control run, {+-} 50% NO{sub x}, {+-} 50% VOC, and {+-} 50% NO{sub x} combined with VOC. Probabilistic forecast quality is verified using relative operating characteristic curves, Talagrand diagrams, and a new reliability index. Results show that both meteorology and emission perturbations are needed to have a skillful probabilistic forecast system--the meteorology perturbation is important to capture the ozone temporal and spatial distribution, and the emission perturbation is needed to span the range of ozone-concentration magnitudes. Emission perturbations are more important than meteorology perturbations for capturing the likelihood of high ozone concentrations. Perturbations involving NO{sub x} resulted in a more skillful probabilistic forecast for the episode analyzed, and therefore the 50% perturbation values appears to span much of the emission uncertainty for this case. All of the ensembles analyzed show a high ozone concentration bias in the Talagrand diagrams, even when the biases from the unperturbed emissions forecasts are removed from all ensemble members. This result indicates nonlinearity in the ensemble, which arises from both ozone chemistry and its interaction with input from particular meteorological models.

  19. Ozone trends: A review

    NASA Astrophysics Data System (ADS)

    Staehelin, J.; Harris, N. R. P.; Appenzeller, C.; Eberhard, J.

    2001-05-01

    Ozone plays a very important role in our atmosphere because it protects any living organisms at the Earth's surface against the harmful solar UVB and UVC radiation. In the stratosphere, ozone plays a critical role in the energy budget because it absorbs both solar UV and terrestrial IR radiation. Further, ozone in the tropopause acts as a strong greenhouse gas, and increasing ozone trends at these altitudes contribute to climate change. This review contains a short description of the various techniques that provided atmospheric ozone measurements valuable for long-term trend analysis. The anthropogenic emissions of substances that deplete ozone (chlorine- and bromine-containing volatile gases) have increased from the 1950s until the second half of the 1980s. The most severe consequence of the anthropogenic release of ozone-depleting substances is the "Antarctic ozone hole." Long-term observations indicate that stratospheric ozone depletion in the southern winter-spring season over Antarctica started in the late 1970s, leading to a strong decrease in October total ozone means. Present values are only approximately half of those observed prior to 1970. In the Arctic, large ozone depletion was observed in winter and spring in some recent years. Satellite and ground-based measurements show no significant trends in the tropics but significant long-term decreasing trends in the northern and southern midlatitudes (of the order of 2-4% per decade in the period from 1970 to 1996 and an acceleration in trends in the 1980s). Ozone at northern midlatitudes decreased by -7.4±2% per decade at 40 km above mean sea level, while ozone loss was small at 30 km. Large trends were found in the lower stratosphere, -5.1±1.8% at 20 km and -7.3±4.6% at 15 km, where the bulk of the ozone resides. The possibility of a reduction in the observed trends has been discussed recently, but it is very hard to distinguish this from the natural variability. As a consequence of the Montreal Protocol

  20. A study of interferences in ambient ozone monitors

    SciTech Connect

    Kleindienst, T.E.; McIver, C.D.; Ollison, W.M.

    1997-12-31

    Recently proposed EPA revisions to the ozone ambient air quality standards change allowable ozone levels from 120 ppbv (1-hour average) to 70-90 ppbv (8-hour average). Accordingly, the relative importance of potential interferences in currently deployed ethylene-chemiluminescence and ultraviolet (UV) absorption monitors may be increased. UV absorption monitors predominate US monitoring networks and operate in a dual channel mode, requiring a scrubber to selectively remove ozone from other UV absorbing species. However, these scrubbers may also remove aromatic species with UV absorption coefficients at 254 run comparable to ozone that could constitute potential interferants. The interference potential for only a few of these compounds has been determined. Additional representative organic precursor species likely to be present under polluted conditions (e.g., C{sub 8}-C{sub 9} aromatic hydrocarbons and their nitroaromatic and phenolic derivatives) have been tested as UV interferants in this study. The removal and reentrainment of aromatic pollutants on ozone scrubbers used in UV monitors is highly dependent on the relative humidity in the system. Raising the temperature of the scrubber does not improve its interferant transmission under dry conditions and increases the retention of potential interferants under humid conditions. Reduced sulfur compounds such as CS{sub 2} do not appear to be interferants for the chemiluminescence monitor.

  1. Rebound of Antarctic ozone

    NASA Astrophysics Data System (ADS)

    Salby, Murry; Titova, Evgenia; Deschamps, Lilia

    2011-05-01

    Restrictions on CFCs have led to a gradual decline of Equivalent Effective Stratospheric Chlorine (EESC). A rebound of Antarctic ozone, however, has remained elusive, masked by large interannual changes that dominate its current evolution. A positive response of ozone is not expected to emerge for at least 1-2 decades, possibly not for half a century. We show that interannual changes of the Antarctic ozone hole are accounted for almost perfectly by changes in dynamical forcing of the stratosphere. The close relationship enables dynamically-induced changes of ozone to be removed, unmasking the climate signal associated with CFCs. The component independent of dynamically-induced changes exhibits a clear upward trend over the last decade - the first signature of a rebound in Antarctic ozone. It enables ozone to be tracked relative to CFCs and other changes of climate.

  2. Ozone therapy in periodontics

    PubMed Central

    Gupta, G; Mansi, B

    2012-01-01

    Gingival and Periodontal diseases represent a major concern both in dentistry and medicine. The majority of the contributing factors and causes in the etiology of these diseases are reduced or treated with ozone in all its application forms (gas, water, oil). The beneficial biological effects of ozone, its anti-microbial activity, oxidation of bio-molecules precursors and microbial toxins implicated in periodontal diseases and its healing and tissue regeneration properties, make the use of ozone well indicated in all stages of gingival and periodontal diseases. The primary objective of this article is to provide a general review about the clinical applications of ozone in periodontics. The secondary objective is to summarize the available in vitro and in vivo studies in Periodontics in which ozone has been used. This objective would be of importance to future researchers in terms of what has been tried and what the potentials are for the clinical application of ozone in Periodontics. PMID:22574088

  3. Ozone flow visualization techniques

    NASA Technical Reports Server (NTRS)

    Dickerson, R. R.; Stedman, D. H.

    1981-01-01

    Flow visualization techniques using ozone for tracing gas flows are proposed whereby ozone is detected through its strong absorption of ultraviolet light, which is easily made visible with fluorescent materials, or through its reaction with nitric oxide to form excited nitrogen dioxide, which in relaxing emits detectable light. It is shown that response speeds in the kHz range are possible with an ultraviolet detection system for initial ozone concentrations of about 1%.

  4. The Antarctic ozone hole

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.

    1988-01-01

    Processes that may be responsible for the thinning in the ozone layer above the South Pole are described. The chlorine catalytic cycle which destroys ozone is described, as are the major types of reactions that are believed to interfere with this cycle by forming chlorine reservoirs. The suspected contributions of polar stratospheric clouds to these processes are examined. Finally, the possibility that the ozone hole may be due more to a shift in atmospheric dynamics than to chemical destruction is addressed.

  5. An automated ozone photometer

    NASA Technical Reports Server (NTRS)

    Lavelle, Joseph R.

    1988-01-01

    A photometer capable of automatically measuring ozone concentration data to very high resolution during scientific research flights in the earth's atmosphere was developed at the NASA Ames Research Center. This instrument was recently deployed to study the ozone hole over Antarctica. Ozone is detected by absorbing 253.7-nm radiation from an ultraviolet lamp which shines through the sample of air and impinges on a vacuum phototube. A lower output from the phototube indicates more ozone present in the air sample. The photometer employs a CMOS 280 control, data collection, and storage.

  6. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    .... Control obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the... NAAQS maintenance area, the State may request that obligations under the applicable requirements of § 51... requirement to submit a maintenance plan for purposes of paragraph (a)(3)(iii) of this section. 40 CFR part...

  7. 40 CFR 52.282 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... in 1990, and 40 CFR 51.905(a)(4). Elements of the section 110(a)(1) maintenance plan for ozone... Air Act section 110(a)(1) and 40 CFR 51.905(a)(4) and is approved as a revision to the California... (see 40 CFR 51.918), this determination suspends the reasonable further progress and...

  8. 40 CFR 52.282 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... in 1990, and 40 CFR 51.905(a)(4). Elements of the section 110(a)(1) maintenance plan for ozone... Air Act section 110(a)(1) and 40 CFR 51.905(a)(4) and is approved as a revision to the California... (see 40 CFR 51.918), this determination suspends the reasonable further progress and...

  9. 40 CFR 52.282 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... in 1990, and 40 CFR 51.905(a)(4). Elements of the section 110(a)(1) maintenance plan for ozone... Air Act section 110(a)(1) and 40 CFR 51.905(a)(4) and is approved as a revision to the California... (see 40 CFR 51.918), this determination suspends the reasonable further progress and...

  10. 40 CFR 52.282 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... in 1990, and 40 CFR 51.905(a)(4). Elements of the section 110(a)(1) maintenance plan for ozone... Air Act section 110(a)(1) and 40 CFR 51.905(a)(4) and is approved as a revision to the California... (see 40 CFR 51.918), this determination suspends the reasonable further progress and...

  11. 40 CFR 52.282 - Control strategy and regulations: Ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... in 1990, and 40 CFR 51.905(a)(4). Elements of the section 110(a)(1) maintenance plan for ozone... Air Act section 110(a)(1) and 40 CFR 51.905(a)(4) and is approved as a revision to the California... (see 40 CFR 51.918), this determination suspends the reasonable further progress and...

  12. Ozone Quenching Properties of Isoprene and Its Antioxidant Role in Leaves1

    PubMed Central

    Loreto, Francesco; Mannozzi, Michela; Maris, Christophe; Nascetti, Pamela; Ferranti, Francesco; Pasqualini, Stefania

    2001-01-01

    Isoprene is formed in and emitted by plants and the reason for this apparent carbon waste is still unclear. It has been proposed that isoprene stabilizes cell and particularly chloroplast thylakoid membranes. We tested if membrane stabilization or isoprene reactivity with ozone induces protection against acute ozone exposures. The reduction of visible, physiological, anatomical, and ultrastructural (chloroplast) damage shows that clones of plants sensitive to ozone and unable to emit isoprene become resistant to acute and short exposure to ozone if they are fumigated with exogenous isoprene, and that isoprene-emitting plants that are sensitive to ozone do not suffer damage when exposed to ozone. Isoprene-induced ozone resistance is associated with the maintenance of photochemical efficiency and with a low energy dissipation, as indicated by fluorescence quenching. This suggests that isoprene effectively stabilizes thylakoid membranes. However, when isoprene reacts with ozone within the leaves or in a humid atmosphere, it quenches the ozone concentration to levels that are less or non-toxic for plants. Thus, protection from ozone in plants fumigated with isoprene may be due to a direct ozone quenching rather than to an induced resistance at membrane level. Irrespective of the mechanism, isoprene is one of the most effective antioxidants in plants. PMID:11457950

  13. Implant Maintenance: A Clinical Update

    PubMed Central

    Gulati, Minkle; Govila, Vivek; Anand, Vishal; Anand, Bhargavi

    2014-01-01

    Introduction. The differences in the supporting structure of the implant make them more susceptible to inflammation and bone loss when plaque accumulates as compared to the teeth. Therefore, a comprehensive maintenance protocol should be followed to ensure the longevity of the implant. Material and Method. A research to provide scientific evidence supporting the feasibility of various implant care methods was carried out using various online resources to retrieve relevant studies published since 1985. Results. The electronic search yielded 708 titles, out of which a total of 42 articles were considered appropriate and finally included for the preparation of this review article. Discussion. A typical maintenance visit for patients with dental implants should last 1 hour and should be scheduled every 3 months to evaluate any changes in their oral and general history. It is essential to have a proper instrument selection to prevent damage to the implant surface and trauma to the peri-implant tissues. Conclusion. As the number of patients opting for dental implants is increasing, it becomes increasingly essential to know the differences between natural teeth and implant care and accept the challenges of maintaining these restorations. PMID:27437506

  14. Prospective validation of a 1-hour algorithm to rule-out and rule-in acute myocardial infarction using a high-sensitivity cardiac troponin T assay

    PubMed Central

    Reichlin, Tobias; Twerenbold, Raphael; Wildi, Karin; Gimenez, Maria Rubini; Bergsma, Nathalie; Haaf, Philip; Druey, Sophie; Puelacher, Christian; Moehring, Berit; Freese, Michael; Stelzig, Claudia; Krivoshei, Lian; Hillinger, Petra; Jäger, Cedric; Herrmann, Thomas; Kreutzinger, Philip; Radosavac, Milos; Weidmann, Zoraida Moreno; Pershyna, Kateryna; Honegger, Ursina; Wagener, Max; Vuillomenet, Thierry; Campodarve, Isabel; Bingisser, Roland; Miró, Òscar; Rentsch, Katharina; Bassetti, Stefano; Osswald, Stefan; Mueller, Christian

    2015-01-01

    Background: We aimed to prospectively validate a novel 1-hour algorithm using high-sensitivity cardiac troponin T measurement for early rule-out and rule-in of acute myocardial infarction (MI). Methods: In a multicentre study, we enrolled 1320 patients presenting to the emergency department with suspected acute MI. The high-sensitivity cardiac troponin T 1-hour algorithm, incorporating baseline values as well as absolute changes within the first hour, was validated against the final diagnosis. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data and serial measurements of high-sensitivity cardiac troponin T levels. Results: Acute MI was the final diagnosis in 17.3% of patients. With application of the high-sensitivity cardiac troponin T 1-hour algorithm, 786 (59.5%) patients were classified as “rule-out,” 216 (16.4%) were classified as “rule-in” and 318 (24.1%) were classified to the “observational zone.” The sensitivity and the negative predictive value for acute MI in the rule-out zone were 99.6% (95% confidence interval [CI] 97.6%–99.9%) and 99.9% (95% CI 99.3%–100%), respectively. The specificity and the positive predictive value for acute MI in the rule-in zone were 95.7% (95% CI 94.3%–96.8%) and 78.2% (95% CI 72.1%–83.6%), respectively. The 1-hour algorithm provided higher negative and positive predictive values than the standard interpretation of highsensitivity cardiac troponin T using a single cut-off level (both p < 0.05). Cumulative 30-day mortality was 0.0%, 1.6% and 1.9% in patients classified in the rule-out, observational and rule-in groups, respectively (p = 0.001). Interpretation: This rapid strategy incorporating high-sensitivity cardiac troponin T baseline values and absolute changes within the first hour substantially accelerated the management of suspected acute MI by allowing safe rule-out as well as accurate

  15. Polar Ozone Workshop. Abstracts

    NASA Technical Reports Server (NTRS)

    Aikin, Arthur C.

    1988-01-01

    Results of the proceedings of the Polar Ozone Workshop held in Snowmass, CO, on May 9 to 13, 1988 are given. Topics covered include ozone depletion, ozonometry, polar meteorology, polar stratospheric clouds, remote sensing of trace gases, atmospheric chemistry and dynamical simulations.

  16. The Antarctic Ozone Hole.

    ERIC Educational Resources Information Center

    Stolarski, Richard S.

    1988-01-01

    Discusses the Airborne Antarctic Ozone Experiment (1987) and the findings of the British Antarctic Survey (1985). Proposes two theories for the appearance of the hole in the ozone layer over Antarctica which appears each spring; air pollution and natural atmospheric shifts. Illustrates the mechanics of both. Supports worldwide chlorofluorocarbon…

  17. Surface Ozone in Kiev

    NASA Astrophysics Data System (ADS)

    Shavrina, A. V.; Mikulskaya, I. A.; Kiforenko, S. I.; Blum, O. B.; Sheminova, V. A.; Veles, A. A.

    The study of total ozone over Kiev and its concentration changes with height in the troposphere has been made on the base of ground-based observations with the infrared Fourier-spectrometer in the Main Astronomical Observatory of National Academy of Sciences of Ukraine (MAO NASU) as part of ESA-NIVR-KNMI project no 2907 "OMI validation by ground based remote sensing: ozone columns and atmospheric profiles "(2005-2008) [1,2,4]. Ground-level ozone in Kiev for an episode of its high concentrations in August 2000 was also simulated with the model of urban air pollution UAM-V [5,6]. In 2008 the satellite data Aura-OMI on profiles of ozone in the atmosphere OMO3PR became available (http://disc.sci.gsfc.nasa.gov/ Aura/data-holdings/OMI/ omo3pr_v003.shtml). They include ozone content in the lower layer of the atmosphere, beginning from 2005, which can be used to evaluate the ground-level ozone in all cities of Ukraine. The comparison of the data of ozone air pollution in Kiev (ozone - the pollutant of the first class of danger) and medical statistics data of of respiratory system (RS) diseases of the city population was carried out with the package "Statistica". A regression analysis, prognostic regression modelling, and retrospective prognosis of the epidemiological situation with respect to RS pathologies in Kiev in 2000-2006 were performed.

  18. Ozone and temperature trends

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.; Fioletov, Vitali; Bishop, Lane; Godin, Sophie; Bojkov, Rumen D.; Kirchhoff, Volker; Chanin, Marie-Lise; Zawodny, Joseph M.; Zerefos, Christos S.; Chu, William

    1991-01-01

    An update of the extensive reviews of the state of knowledge of measured ozone trends published in the Report of the International Ozone Trends Panel is presented. The update contains a review of progress since these reports, including reviewing of the ozone records, in most cases through March 1991. Also included are some new, unpublished reanalyses of these records including a complete reevaluation of 29 stations located in the former Soviet Union. The major new advance in knowledge of the measured ozone trend is the existence of independently calibrated satellite data records from the Total Ozone Mapping Spectrometer (TOMS) and Stratospheric Aerosol and Gas Experiment (SAG) instruments. These confirm many of the findings, originally derived from the Dobson record, concerning northern mid-latitude changes in ozone. We now have results from several instruments, whereas the previously reported changes were dependent on the calibration of a single instrument. This update will compare the ozone records from many different instruments to determine whether or not they provide a consistent picture of the ozone change that has occurred in the atmosphere. The update also briefly considers the problem of stratospheric temperature change. As in previous reports, this problem received significantly less attention, and the report is not nearly as complete. This area needs more attention in the future.

  19. Saving Our Ozone Shield.

    ERIC Educational Resources Information Center

    Lacoste, Beatrice

    1992-01-01

    Discusses the introduction and continued use of chlorofluorocarbons (CFCs) as related to stratospheric ozone depletion. Presents the characteristics of CFCs conducive to the chemical reaction with ozone, the history of CFC use and detection of related environmental problems, health hazards, and alternatives to CFC use. (MCO)

  20. Observing trends in total ozone and extreme ozone events

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2014-05-01

    The ozone layer in the stratosphere has been recovering since the 1989 Montreal Protocol reduced the use of ozone-destroying chlorofluorocarbons. Fitzka et al. observed trends in total ozone levels and the vertical distribution of ozone at Hoher Sonnblick, a mountain in Austria, from 1994 to 2011.

  1. The Hole in the Ozone Layer.

    ERIC Educational Resources Information Center

    Hamers, Jeanne S.; Jacob, Anthony T.

    This document contains information on the hole in the ozone layer. Topics discussed include properties of ozone, ozone in the atmosphere, chlorofluorocarbons, stratospheric ozone depletion, effects of ozone depletion on life, regulation of substances that deplete the ozone layer, alternatives to CFCs and Halons, and the future of the ozone layer.…

  2. The Two Faces of Ozone.

    ERIC Educational Resources Information Center

    Monastersky, Richard

    1989-01-01

    Provides answers to questions regarding the ozone problem: (1) nature of ozone in the troposphere and stratosphere; (2) possibility of sending the excess ozone at ground level to the stratosphere; (3) possibility of producing pure ozone and carrying it to the stratosphere; and (4) banning chlorofluorocarbons. (YP)

  3. Fundamentals of ISCO Using Ozone

    EPA Science Inventory

    In situ chemical oxidation (ISCO) using ozone involves the introduction of ozone gas (O3) into the subsurface to degrade organic contaminants of concern. Ozone is tri-molecular oxygen (O2) that is a gas under atmospheric conditions and is a strong oxidant. Ozone may react with ...

  4. Maintenance Business Plans.

    ERIC Educational Resources Information Center

    Adams, Matt

    2002-01-01

    Discusses maintenance business plans, statements which provide accountability for facilities maintenance organizations' considerable budgets. Discusses the plan's components: statement of plan objectives, macro and detailed description of the facility assets, maintenance function descriptions, description of key performance indicators, milestone…

  5. Stratospheric ozone depletion

    PubMed Central

    Rowland, F. Sherwood

    2006-01-01

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290–320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime—the ‘Antarctic ozone hole’. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  6. Stratospheric ozone depletion.

    PubMed

    Rowland, F Sherwood

    2006-05-29

    Solar ultraviolet radiation creates an ozone layer in the atmosphere which in turn completely absorbs the most energetic fraction of this radiation. This process both warms the air, creating the stratosphere between 15 and 50 km altitude, and protects the biological activities at the Earth's surface from this damaging radiation. In the last half-century, the chemical mechanisms operating within the ozone layer have been shown to include very efficient catalytic chain reactions involving the chemical species HO, HO2, NO, NO2, Cl and ClO. The NOX and ClOX chains involve the emission at Earth's surface of stable molecules in very low concentration (N2O, CCl2F2, CCl3F, etc.) which wander in the atmosphere for as long as a century before absorbing ultraviolet radiation and decomposing to create NO and Cl in the middle of the stratospheric ozone layer. The growing emissions of synthetic chlorofluorocarbon molecules cause a significant diminution in the ozone content of the stratosphere, with the result that more solar ultraviolet-B radiation (290-320 nm wavelength) reaches the surface. This ozone loss occurs in the temperate zone latitudes in all seasons, and especially drastically since the early 1980s in the south polar springtime-the 'Antarctic ozone hole'. The chemical reactions causing this ozone depletion are primarily based on atomic Cl and ClO, the product of its reaction with ozone. The further manufacture of chlorofluorocarbons has been banned by the 1992 revisions of the 1987 Montreal Protocol of the United Nations. Atmospheric measurements have confirmed that the Protocol has been very successful in reducing further emissions of these molecules. Recovery of the stratosphere to the ozone conditions of the 1950s will occur slowly over the rest of the twenty-first century because of the long lifetime of the precursor molecules. PMID:16627294

  7. A Total Ozone Dependent Ozone Profile Climatology Based on Ozone-Sondes and Aura MLS Data

    NASA Astrophysics Data System (ADS)

    Labow, G. J.; McPeters, R. D.; Ziemke, J. R.

    2014-12-01

    A new total ozone-based ozone profile climatology has been created for use in satellite and/or ground based ozone retrievals. This climatology was formed by combining data from the Microwave Limb Sounder (MLS) with data from balloon sondes and binned by zone and total ozone. Because profile shape varies with total column ozone, this climatology better captures the ozone variations than the previously used seasonal climatologies, especially near the tropopause. This is significantly different than ozone climatologies used in the past as there is no time component. The MLS instrument on Aura has excellent latitude coverage and measures ozone profiles daily from the upper troposphere to the lower mesosphere at ~3.5 km resolution. Almost a million individual MLS ozone measurements are merged with data from over 55,000 ozonesondes which are then binned as a function of total ozone. The climatology consists of average ozone profiles as a function of total ozone for six 30 degree latitude bands covering altitudes from 0-75 km (in Z* pressure altitude coordinates). This new climatology better represents the profile shape as a function of total ozone than previous climatologies and shows some remarkable and somewhat unexpected correlations between total ozone and ozone in the lower altitudes, particularly in the lower and middle troposphere. These data can also be used to infer biases and errors in either the MLS retrievals or ozone sondes.

  8. Ozone - plant surface reactions an important ozone loss term?

    NASA Astrophysics Data System (ADS)

    Hansel, Armin; Jud, Werner; Fischer, Lukas; Canaval, Eva; Wohlfahrt, Georg; Tissier, Alain

    2015-04-01

    Elevated tropospheric ozone concentrations are considered a toxic threat to plants responsible for global crop losses with associated economic costs of several billions dollar per year. Plant injuries have been related to the uptake of ozone through stomatal pores and oxidative effects damaging the internal leaf tissue. But a striking question remains: How much ozone enters the plant through open stomata and how much ozone is lost by chemical reactions at the plant surface? Until now surface losses are estimated from measured total ozone deposition fluxes and calculated stomatal conductance values. While stomatal conductance of CO2 and H2O is well understood and extensively used in describing plant atmosphere gas exchange, stomatal conductance of ozone is not well known. Here we use different Nicotiana tabacum varieties and find that surface reactions of ozone with diterpenoids synthesized by glandular trichomes reduce ozone flux through open stomata. Our measurements reveal that fast ozone loss at the plant surface is accompanied with prompt release of oxygenated volatile compounds. In the ozone fumigation experiments of different Nicotiana tabacum varieties the release of specific volatile oxy-VOCs allowed to identify the semi volatile precursor compounds at the plant surface. Ozone fumigation experiments with Norway spruce (Picea abies) and Scots Pine (Pinus sylvestris), two common species in the Northern Hemisphere, show also a significant ozone loss at the plant surface for Picea abies. Fluid dynamic calculations of ozone transport in the diffusive leaf boundary layer reveal a vertical but no horizontal ozone gradient thus reducing ozone fluxes through the pores in case of efficient ozone scavenging plant surfaces. We explain this efficient ozone protection mechanism by the porous surface architecture of plants in combination with unsaturated semi-volatile compounds deposited at the plant surface. These results show that unsaturated semi-volatile compounds at

  9. The impact of meteorology on ozone in Houston

    SciTech Connect

    Eder, B.K.; Davis, J.M.; Nychka, D.

    1997-12-31

    This paper compares the results from both a one-stage hierarchical clustering technique (average linkage) and a two-stage technique (average linkage then k-means) as part of an objective meteorological Classification scheme designed to better elucidate ozone`s dependence on meteorology in the Houston, Texas, area. When applied to twelve years of meteorological data (1981-1992), each technique identified seven statistically distinct meteorological regimes, the majority of which exhibited significantly different daily 1-hour maximum ozone (O{sub 3}) concentrations. While both clustering approaches proved successful, the two-stage approach did appear superior in terms of better segregation of the mean O{sub 3}, concentrations. Both approaches indicated that the largest mean daily one-hour maximum concentrations are associated with migrating anticyclones and not with the quasi-permanent Bermuda High that often dominates the southeastern United States during the summer. As a result, maximum ozone concentrations are just as likely during the months of April, May, September and October as they are during the summer months. These findings support and help explain the unique O{sub 3}, climatology experienced by the Houston area.

  10. Low density solid ozone

    SciTech Connect

    Teolis, B. D.; Fama, M.; Baragiola, R. A.

    2007-08-21

    We report a very low density ({approx}0.5 g/cm{sup 3}) structure of solid ozone. It is produced by irradiation of solid oxygen with 100 keV protons at 20 K followed by heating to sublime unconverted oxygen. Upon heating to 47 K the porous ozone compacts to a density of {approx}1.6 g/cm{sup 3} and crystallizes. We use a detailed analysis of the main infrared absorption band of the porous ozone to interpret previous research, where solid oxygen was irradiated by UV light and keV electrons.

  11. Arctic ozone loss

    SciTech Connect

    Zurer, P.S.

    1989-03-06

    Scientists have returned from the first comprehensive probe of the Arctic stratosphere with unexpectedly dire results: The winter atmosphere in the north polar region is loaded with the same destructive chlorine compounds that cause the Antarctic ozone hole. Atmospheric researchers who only a few weeks ago were comforted by the thought that the warmer Northern Hemisphere is strongly protected from the processes that lead to massive losses of ozone during spring in Antarctica now see very little standing in the way of an Arctic ozone hole.

  12. Amazon basin ozone and aerosol: Wet season observations

    SciTech Connect

    Gregory, G.L.; Browell, E.V.; Warren, L.S.; Hudgins, C.H. )

    1990-09-20

    The tropical environment is recognized as having a major impact on global tropospheric chemistry. The data show that the wet season Amazon Basin is an effective sink for ozone and a net source for aerosols. Mixed layer ozone at 150-m altitude averaged 8.5 ppbv compared to about 18 ppbv at 3-km altitude. In addition, a negative ozone gradient (decreasing value to the surface) was observed within the mixed layer. The averaged wet season mixed layer ozone was about 7 ppbv lower than observed during the dry season. This is attributed to the enhanced convective activity associated with the wet season and the change in mixed layer photochemistry from net ozone production (dry season) to a net destruction (wet season). The net sink characteristics of the wet season mixed layer are seen throughout the troposphere of the Amazon Basin in that ozone (3- to 4-km altitude) is typically 15-25 ppbv as compared to dry season values of 30-35 ppbv. In terms of the aerosol source characteristics of the Amazon Basin, mixed layer aerosols (0.1- to 0.4-{mu}m diameter) are a factor of 5-10 higher than observed in the troposphere with mixed layer values of 100-200 aerosols/cm{sup 3}. Analyses of both tropospheric and mixed layer aerosol samples show aerosols which are multisource. Tropospheric samples have size distributions which are trimodal and show modes at aerosol diameters which suggest the aerosols are (1) of lifetimes <1 hour, (2) of lifetimes of days, and (3) mechanically generated elements (e.g., wind-blow dust). Mixed layer data show two of the three modes with no mode which represent aerosols with lifetimes of days.

  13. Ozone Therapy in Dentistry

    PubMed Central

    Domb, William C

    2014-01-01

    Summary The 21st century dental practice is quite dynamic. New treatment protocols and new materials are being developed at a rapid pace. Ozone dental therapy falls into the category of new treatment protocols in dentistry, yet ozone is not new at all. Ozone therapy is already a major treatment modality in Europe, South America and a number of other countries. What is provided here will not be an exhaustive scientific treatise so much as a brief general introduction into what dentists are now doing with ozone therapies and the numerous oral/systemic links that make this subject so important for physicians so that, ultimately, they may serve their patients more effectively and productively. PMID:25363268

  14. The ozone backlash

    SciTech Connect

    Taubes, G.

    1993-06-11

    While evidence for the role of chlorofluorocarbons in ozone depletion grows stronger, researchers have recently been subjected to vocal public criticism of their theories-and their motives. Their understanding of the mechanisms of ozone destruction-especially the annual ozone hole that appears in the Antarctic-has grown stronger, yet everywhere they go these days, they seem to be confronted by critics attacking their theories as baseless. For instance, Rush Limbaugh, the conservative political talk-show host and now-best-selling author of The Way Things Ought to Be, regularly insists that the theory of ozone depletion by CFCs is a hoax: bladerdash and poppycock. Zoologist Dixy Lee Ray, former governor of the state of Washington and former head of the Atomic Energy Commission, makes the same argument in her book, Trashing the Planet. The Wall Street Journal and National Review have run commentaries by S. Fred Singer, a former chief scientists for the Department of Transportation, purporting to shoot holes in the theory of ozone depletion. Even the June issue of Omni, a magazine with a circulation of more than 1 million that publishes a mixture of science and science fiction, printed a feature article claiming to expose ozone research as a politically motivated scam.

  15. Cryogenics maintenance strategy

    NASA Astrophysics Data System (ADS)

    Cruzat, Fabiola

    2012-09-01

    ALMA is an interferometer composed of 66 independent systems, with specific maintenance requirements for each subsystem. To optimize the observation time and reduce downtime maintenance, requirements are very demanding. One subsystem with high maintenance efforts is cryogenics and vacuum. To organize the maintenance, the Cryogenic and Vacuum department is using and implementing different tools. These are monitoring and problem reporting systems and CMMS. This leads to different maintenance approaches: Preventive Maintenance, Corrective Maintenance and Condition Based Maintenance. In order to coordinate activities with other departments the preventive maintenance schedule is kept as flexible as systems allow. To cope with unavoidable failures, the team has to be prepared to work under any condition with the spares on time. Computerized maintenance management system (CMMS) will help to manage inventory control for reliable spare part handling, the correct record of work orders and traceability of maintenance activities. For an optimized approach the department is currently evaluating where preventive or condition based maintenance applies to comply with the individual system demand. Considering the change from maintenance contracts to in-house maintenance will help to minimize costs and increase availability of parts. Due to increased number of system and tasks the cryo team needs to grow. Training of all staff members is mandatory, in depth knowledge must be built up by doing complex maintenance activities in the Cryo group, use of advanced computerized metrology systems.

  16. MULTIPOLLUTANT METHODS - METHODS FOR OZONE AND OZONE PRECURSORS

    EPA Science Inventory

    This task involves the development and testing of methods for monitoring ozone and compounds associated with the atmospheric chemistry of ozone production both as precursors and reaction products. Although atmospheric gases are the primary interest, separation of gas and particl...

  17. Ozone Depletion by Hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    Hurwitz, M.; Fleming, E. L.; Newman, P. A.; Li, F.; Mlawer, E. J.; Cady-Pereira, K. E.; Bailey, R.

    2015-12-01

    Hydrofluorocarbons (HFCs) are second-generation replacements for the chlorofluorocarbons (CFCs), halons and other substances that caused the 'ozone hole'. Atmospheric concentrations of HFCs are projected to increase dramatically in the coming decades. Coupled chemistry-climate simulations forced by these projections show that HFCs will impact the global atmosphere in 2050. As strong radiative forcers, HFCs modulate atmospheric temperature, thereby changing ozone-destroying catalytic cycles and enhancing the stratospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Sensitivity simulations with the NASA Goddard Space Flight Center (GSFC) 2D model show that HFC-125 is the most important contributor to atmospheric change in 2050, as compared with HFC-23, HFC-32, HFC-134a and HFC-143a. Incorporating the interactions between chemistry, radiation and dynamics, for a likely 2050 climate, ozone depletion potentials (ODPs) for HFCs range from 4.3x10-4 to 3.5x10-2; previously HFCs were assumed to have negligible ODPs since these species lack chlorine or bromine atoms. The ozone impacts of HFCs are further investigated with the Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). The GEOSCCM is a three-dimensional, fully coupled ocean-atmosphere model with interactive stratospheric chemistry. Sensitivity simulations in which CO2, CFC-11 and HCFC-22 are enhanced individually are used as proxies for the atmospheric response to the HFC concentrations expected by the mid-21st century. Sensitivity simulations provide quantitative estimates of the impacts of these greenhouse gases on global total ozone, and can be used to assess their effects on the recovery of Antarctic ozone.

  18. Ozonation of Canadian Athabasca asphaltene

    NASA Astrophysics Data System (ADS)

    Cha, Zhixiong

    Application of ozonation in the petrochemical industry for heavy hydrocarbon upgrading has not been sufficiently explored. Among heavy hydrocarbons, asphaltenes are the heaviest and the most difficult fractions for analysis and treatment. Therefore, ozonation of asphaltenes presents an interesting application in the petrochemical industry. Commercial application of ozonation in the petrochemical industry has three obstacles: availability of an ozone-resistant and environmentally friendly solvent, the precipitation of ozonation intermediates during reaction, and recovery of the solvent and separation of the ozonation products. Preliminary ozonation of Athabasca oil sands asphaltene in nonparticipating solvents encountered serious precipitation of the ozonation intermediates. The precipitated intermediates could be polymeric ozonides and intermolecular ozonides or polymeric peroxides. Because the inhomogeneous reaction medium caused low ozone efficiency, various participating solvents such as methanol and acetic acid were added to form more soluble hydroperoxides. The mass balance results showed that on average, one asphaltene molecule reacted with 12 ozone molecules through the electrophilic reaction and the subsequent decomposition of ozonation intermediates generated acetone extractable products. GC/MS analysis of these compounds indicated that the free radical reactions could be important for generation of volatile products. The extensively ozonated asphaltene in the presence of participating solvents were refluxed with methanol to generate more volatile products. GC/MS analysis of the methanol-esterified ozonation products indicated that most volatile products were aliphatic carboxylic acid esters generated through cleavage of substituents. Reaction kinetics study showed that asphaltene ozonation was initially a diffusion rate-controlled reaction and later developed to a chemical reaction rate-controlled reaction after depletion of the reactive aromatic sites

  19. Alternative Electrochemical Systems for Ozonation of Water

    NASA Technical Reports Server (NTRS)

    Andrews, Craig C.; Murphy, Oliver J.

    2003-01-01

    Electrochemical systems that are especially well suited for the small-scale generation of ozone and ozonated water for local use have been invented. These systems can operate with very little maintenance, and the only inputs needed during operation are electric power and water. Ozonated water produced by these systems can be used in diverse industrial applications: A few examples include sterilization in the brewing industry, general disinfection, and treatment of sewage and recycled water. The basic principle of operation admits of several alternative system configurations. The heart of the system is a stack of electrolytic cells, each containing a proton-exchange membrane (which serves as a solid electrolyte) sandwiched between a catalytic anode and a catalytic cathode. Preferably, the proton-exchange membrane is made of a perfluorinated sulfonic acid polymer. During electrolysis, a mixture of O2 and O3 gases is generated at the anode and H2 is generated at the cathode. Some of the O3 generated at the anode becomes dissolved in the water. The proportion of O3 in the O2/O3 mixture can be maximized by the selection of suitable electrode materials and the use of a high overpotential. Although the proton-exchange membrane conducts protons, it does not conduct electrons. It is also impermeable by gases; consequently, it maintains separation between the O2/O3 mixture evolved at the anode and the H2 evolved at the cathode.

  20. Ozone Contamination in Aircraft Cabins. Appendix A: Ozone toxicity

    NASA Technical Reports Server (NTRS)

    Melton, C. E.

    1979-01-01

    The recommendation that at various altitudes the amount of air with which ozone has mixed changes, thus changing the volume per volume relationship is discussed. The biological effects of ozone on human health and the amount of ozone necessary to produce symptoms were investigated.

  1. Children's Models of the Ozone Layer and Ozone Depletion.

    ERIC Educational Resources Information Center

    Christidou, Vasilia; Koulaidis, Vasilis

    1996-01-01

    The views of 40 primary students on ozone and its depletion were recorded through individual, semi-structured interviews. The data analysis resulted in the formation of a limited number of models concerning the distribution and role of ozone in the atmosphere, the depletion process, and the consequences of ozone depletion. Identifies five target…

  2. CONTRIBUTION TO INDOOR OZONE LEVELS OF AN OZONE GENERATOR

    EPA Science Inventory

    This report gives results of a study of a commonly used commercially available ozone generator, undertaken to determine its impact on indoor ozone levels. xperiment were conducted in a typical mechanically ventilated office and in a test house. he generated ozone and the in-room ...

  3. Ozone Minimums, 1979 to 2013

    NASA Video Gallery

    Minimum concentration of ozone in the southern hemisphere for each year from 1979-2013 (there is no data from 1995). Each image is the day of the year with the lowest concentration of ozone. A grap...

  4. "OZONE SOURCE APPORTIONMENT IN CMAQ'

    EPA Science Inventory

    Ozone source attribution has been used to support various policy purposes including interstate transport (Cross State Air Pollution Rule) by U.S. EPA and ozone nonattainment area designations by State agencies. Common scientific applications include tracking intercontinental tran...

  5. An automated ozone photometer

    NASA Technical Reports Server (NTRS)

    Lavelle, Joseph R.

    1988-01-01

    A photometer capable of automatically measuring ozone concentration data to very high resolution during scientific research flights in the Earth's atmosphere was developed at NASA Ames Research Center. This instrument was recently deployed to study the ozone hole over Antarctica. Ozone is detected by absorbing 253.7-nm radiation from an ultraviolet lamp which shines through the sample of air and impinges on a vacuum phototube. A lower output from the phototube indicates more ozone present in the air sample. The photometer employs a CMOS Z80 microprocessor with an STD bus system for experiment control, data collection, and storage. Data are collected and stored in nonvolatile memory for experiments lasting up to 8 hr. Data are downloaded to a portable ground-support computer and processed after the aircraft lands. An independent single-board computer in the STD bus also calculates ozone concentration in real time with less resolution than the CMOS Z80 system, and sends this value to a cockpit meter to aid the pilot in navigation.

  6. Ames ER-2 ozone measurements

    NASA Technical Reports Server (NTRS)

    Pearson, R., Jr.; Vedder, James F.; Starr, W. L.

    1990-01-01

    The objective of this research is to study ozone (O3) in the stratosphere. Measurements of the ozone mixing ratio at 1 s intervals are obtained with an ultraviolet photometer which flies on the ER-2 aircraft. The photometer determines the amount of ozone in air by measuring the transmission of ultraviolet light through a fixed path with and without ambient O3 present.

  7. Ozone depletion by hydrofluorocarbons

    NASA Astrophysics Data System (ADS)

    Hurwitz, Margaret M.; Fleming, Eric L.; Newman, Paul A.; Li, Feng; Mlawer, Eli; Cady-Pereira, Karen; Bailey, Roshelle

    2015-10-01

    Atmospheric concentrations of hydrofluorocarbons (HFCs) are projected to increase considerably in the coming decades. Chemistry climate model simulations forced by current projections show that HFCs will impact the global atmosphere increasingly through 2050. As strong radiative forcers, HFCs increase tropospheric and stratospheric temperatures, thereby enhancing ozone-destroying catalytic cycles and modifying the atmospheric circulation. These changes lead to a weak depletion of stratospheric ozone. Simulations with the NASA Goddard Space Flight Center 2-D model show that HFC-125 is the most important contributor to HFC-related atmospheric change in 2050; its effects are comparable to the combined impacts of HFC-23, HFC-32, HFC-134a, and HFC-143a. Incorporating the interactions between chemistry, radiation, and dynamics, ozone depletion potentials (ODPs) for HFCs range from 0.39 × 10-3 to 30.0 × 10-3, approximately 100 times larger than previous ODP estimates which were based solely on chemical effects.

  8. SAGE II Ozone Analysis

    NASA Technical Reports Server (NTRS)

    Cunnold, Derek; Wang, Ray

    2002-01-01

    Publications from 1999-2002 describing research funded by the SAGE II contract to Dr. Cunnold and Dr. Wang are listed below. Our most recent accomplishments include a detailed analysis of the quality of SAGE II, v6.1, ozone measurements below 20 km altitude (Wang et al., 2002 and Kar et al., 2002) and an analysis of the consistency between SAGE upper stratospheric ozone trends and model predictions with emphasis on hemispheric asymmetry (Li et al., 2001). Abstracts of the 11 papers are attached.

  9. Facilities maintenance handbook

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This handbook is a guide for facilities maintenance managers. Its objective is to set minimum facilities maintenance standards. It also provides recommendations on how to meet the standards to ensure that NASA maintains its facilities in a manner that protects and preserves its investment in the facilities in a cost-effective manner while safely and efficiently performing its mission. This handbook implements NMI 8831.1, which states NASA facilities maintenance policy and assigns organizational responsibilities for the management of facilities maintenance activities on all properties under NASA jurisdiction. It is a reference for facilities maintenance managers, not a step-by-step procedural manual. Because of the differences in NASA Field Installation organizations, this handbook does not assume or recommend a typical facilities maintenance organization. Instead, it uses a systems approach to describe the functions that should be included in any facilities maintenance management system, regardless of its organizational structure. For documents referenced in the handbook, the most recent version of the documents is applicable. This handbook is divided into three parts: Part 1 specifies common definitions and facilities maintenance requirements and amplifies the policy requirements contained in NMI 8831. 1; Part 2 provides guidance on how to meet the requirements of Part 1, containing recommendations only; Part 3 contains general facilities maintenance information. One objective of this handbook is to fix commonality of facilities maintenance definitions among the Centers. This will permit the application of uniform measures of facilities conditions, of the relationship between current replacement value and maintenance resources required, and of the backlog of deferred facilities maintenance. The utilization of facilities maintenance system functions will allow the Centers to quantitatively define maintenance objectives in common terms, prepare work plans, and

  10. Light Vehicle Preventive Maintenance.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to instruct students in the performance of preventive maintenance on motor vehicles. Instructional materials are presented in three chapters as follows: (1) Major Maintenance Areas (maintenance system, tires, batteries, cooling systems, and vehicle lubrication; (2)…

  11. Asphalt in Pavement Maintenance.

    ERIC Educational Resources Information Center

    Asphalt Inst., College Park, MD.

    Maintenance methods that can be used equally well in all regions of the country have been developed for the use of asphalt in pavement maintenance. Specific information covering methods, equipment and terminology that applies to the use of asphalt in the maintenance of all types of pavement structures, including shoulders, is provided. In many…

  12. Defer Maintenance, Invite Disaster

    ERIC Educational Resources Information Center

    Bowman, William W.

    1977-01-01

    An AGB- and NACUBO-sponsored survey showed that "wish lists" are accumulating overdue major maintenance projects because energy costs are consuming physical plant budgets. Problem areas are discussed: budget "guesstimation," preventive maintenance, deferred maintenance inventory, the APPA accounting format, resource allocation, and inflation.…

  13. Tropospheric ozone in the vicinity of the ozone hole - 1987 Airborne Antarctic Ozone Experiment

    NASA Technical Reports Server (NTRS)

    Gregory, Gerald L.; Warren, Linda S.; Hypes, Warren D.; Tuck, Adrian F.; Kelly, Kenneth K.; Krueger, Arlin J.

    1989-01-01

    Results are presented on ozone measurements in the upper troposphere/lower stratosphere over Antarctica, obtained by NASA DC-8 aircraft during the August/September 1987 Airborne Antarctic Ozone Experiment. The ozone mixing ratios as high as several hundred ppbv were measured, but in all cases these ratios were observed in pockets of upper atmospheric air, both in the vicinity of and away from the location of the ozone hole. The background ozone values in the surrounding troposphere were typically in the range of 20-50 ppbv. Correlation of tropospheric ozone observations with the boundaries of the ozone hole differed in the course of the experiment. During the August 28 - September 2 flights, encounters with ozone-rich air were limited, and the background tropospheric ozone appeared to decrease beneath the hole. For the later flights, and as the ozone hole deepened, the ozone-rich air was frequently observed in the vicinity of the hole, and the average ozone values at the flight altitude were frequently higher than the background values.

  14. Precision ozone vapor pressure measurements

    NASA Technical Reports Server (NTRS)

    Hanson, D.; Mauersberger, K.

    1985-01-01

    The vapor pressure above liquid ozone has been measured with a high accuracy over a temperature range of 85 to 95 K. At the boiling point of liquid argon (87.3 K) an ozone vapor pressure of 0.0403 Torr was obtained with an accuracy of + or - 0.7 percent. A least square fit of the data provided the Clausius-Clapeyron equation for liquid ozone; a latent heat of 82.7 cal/g was calculated. High-precision vapor pressure data are expected to aid research in atmospheric ozone measurements and in many laboratory ozone studies such as measurements of cross sections and reaction rates.

  15. Karlson ozone sterilizer. Final report

    SciTech Connect

    Karlson, E.

    1984-05-07

    The authors have a functional sterilization system employing ozone as a sterilization agent. This final report covers the work that led to the first medical sterilizer using ozone as the sterilizing agent. The specifications and the final design were set by hospital operating room personnel and public safety standards. Work on kill tests using bacteria, viruses and fungi determined the necessary time and concentration of ozone necessary for sterilization. These data were used in the Karlson Ozone Sterilizer to determine the length of the steps of the operating cycle and the concentration of ozone to be used. 27 references.

  16. Total Ozone Prediction: Stratospheric Dynamics

    NASA Technical Reports Server (NTRS)

    Jackman, Charles H.; Kawa, S. Ramdy; Douglass, Anne R.

    2003-01-01

    The correct prediction of total ozone as a function of latitude and season is extremely important for global models. This exercise tests the ability of a particular model to simulate ozone. The ozone production (P) and loss (L) will be specified from a well- established global model and will be used in all GCMs for subsequent prediction of ozone. This is the "B-3 Constrained Run" from M&MII. The exercise mostly tests a model stratospheric dynamics in the prediction of total ozone. The GCM predictions will be compared and contrasted with TOMS measurements.

  17. Assimilation of Satellite Ozone Observations

    NASA Technical Reports Server (NTRS)

    Stajner, I.; Winslow, N.; Wargan, K.; Hayashi, H.; Pawson, S.; Rood, R.

    2003-01-01

    This talk will discuss assimilation of ozone data from satellite-borne instruments. Satellite observations of ozone total columns and profiles have been measured by a series of Total Ozone Mapping Spectrometer (TOMS), Solar Backscatter Ultraviolet (SBUV) instruments, and more recently by the Global Ozone Monitoring Experiment. Additional profile data are provided by instruments on NASA's Upper Atmosphere Research Satellite and by occultation instruments on other platforms. Instruments on Envisat' and future EOS Aura satellite will supply even more comprehensive data about the ozone distribution. Satellite data contain a wealth of information, but they do not provide synoptic global maps of ozone fields. These maps can be obtained through assimilation of satellite data into global chemistry and transport models. In the ozone system at NASA's Data Assimilation Office (DAO) any combination of TOMS, SBUV, and Microwave Limb sounder (MLS) data can be assimilated. We found that the addition of MLS to SBUV and TOMS data in the system helps to constrain the ozone distribution, especially in the polar night region and in the tropics. The assimilated ozone distribution in the troposphere and lower stratosphere is sensitive also to finer changes in the SBUV and TOMS data selection and to changes in error covariance models. All results are established by comparisons of assimilated ozone with independent profiles from ozone sondes and occultation instruments.

  18. The Ozone Show.

    ERIC Educational Resources Information Center

    Mathieu, Aaron

    2000-01-01

    Uses a talk show activity for a final assessment tool for students to debate about the ozone hole. Students are assessed on five areas: (1) cooperative learning; (2) the written component; (3) content; (4) self-evaluation; and (5) peer evaluation. (SAH)

  19. Ozone decomposing filter

    DOEpatents

    Simandl, Ronald F.; Brown, John D.; Whinnery, Jr., LeRoy L.

    1999-01-01

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  20. Ozone and temperature trends

    NASA Technical Reports Server (NTRS)

    Labitzke, K.; Miller, A. J.; Angell, J.; Deluisi, J.; Frederick, J.; Logan, J.; Mateer, C.; Naujokat, B.; Reinsel, G.; Tiao, G.

    1985-01-01

    The measurement of temporal changes in ozone and temperature are discussed. The data are examined within the context of natural atmospheric variability and data problems. The results are compared to numerical model calculations. The major issues are defined in terms of goal achievement. Each parameter is considered in terms of instrument type, long term effects, and altitude.

  1. Ozone decomposing filter

    SciTech Connect

    Simandl, R.F.; Brown, J.D.; Whinnery, L.L. Jr.

    1999-11-02

    In an improved ozone decomposing air filter carbon fibers are held together with a carbonized binder in a perforated structure. The structure is made by combining rayon fibers with gelatin, forming the mixture in a mold, freeze-drying, and vacuum baking.

  2. Ozone Layer Educator's Guide.

    ERIC Educational Resources Information Center

    Environmental Protection Agency, Washington, DC.

    This guide has been developed through a collaborative effort involving the U.S. Environmental Protection Agency (EPA), the National Oceanic and Atmospheric Administration (NOAA), and the National Aeronautics and Space Administration (NASA). It is part of an ongoing commitment to ensure that the results of scientific research on ozone depletion are…

  3. Dobson ozone spectrophotometer modification.

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Grass, R. D.

    1972-01-01

    Description of a modified version of the Dobson ozone spectrophotometer in which several outdated electronic design features have been replaced by circuitry embodying more modern design concepts. The resulting improvement in performance characteristics has been obtained without changing the principle of operation of the original instrument.

  4. Revisiting Antarctic Ozone Depletion

    NASA Astrophysics Data System (ADS)

    Grooß, Jens-Uwe; Tritscher, Ines; Müller, Rolf

    2015-04-01

    Antarctic ozone depletion is known for almost three decades and it has been well settled that it is caused by chlorine catalysed ozone depletion inside the polar vortex. However, there are still some details, which need to be clarified. In particular, there is a current debate on the relative importance of liquid aerosol and crystalline NAT and ice particles for chlorine activation. Particles have a threefold impact on polar chlorine chemistry, temporary removal of HNO3 from the gas-phase (uptake), permanent removal of HNO3 from the atmosphere (denitrification), and chlorine activation through heterogeneous reactions. We have performed simulations with the Chemical Lagrangian Model of the Stratosphere (CLaMS) employing a recently developed algorithm for saturation-dependent NAT nucleation for the Antarctic winters 2011 and 2012. The simulation results are compared with different satellite observations. With the help of these simulations, we investigate the role of the different processes responsible for chlorine activation and ozone depletion. Especially the sensitivity with respect to the particle type has been investigated. If temperatures are artificially forced to only allow cold binary liquid aerosol, the simulation still shows significant chlorine activation and ozone depletion. The results of the 3-D Chemical Transport Model CLaMS simulations differ from purely Lagrangian longtime trajectory box model simulations which indicates the importance of mixing processes.

  5. Chemical and Meteorological Characteristics Leading to the Major Ozone Exceedences (>150 ppb) Observed in Houston, TX During TEXAQS 2000

    NASA Astrophysics Data System (ADS)

    Perkins, K. K.; Ryerson, T. B.; Trainer, M.; Nicks, D. K.; Neuman, J. A.; Holloway, J. S.; Jakoubek, R. O.; Parrish, D. D.; Sueper, D. T.; Frost, G. J.; Kuster, W. C.; Goldan, P. D.; Dissly, R. W.; Hubler, G.; Angevine, W. M.; Fehsenfeld, F. C.; Donnelly, S. G.; Schauffler, S.; Stroud, V.; Atlas, E. L.; Weinheimer, A. J.; Flocke, F.; Wert, B. P.; Potter, W. T.; Fried, A.; Wiedinmyer, C.; Senff, C. J.; Banta, R. M.; Darby, L. S.; Alvarez, R. J.

    2002-12-01

    During summer, the Houston urban area routinely experiences elevated levels of ozone exceeding the EPA air quality limits for ozone of 120 ppbv for 1 hour. These ozone exceedences may reach levels over 200 ppbv and are typically localized plumes rather than large events covering the entire urban area. Airborne measurements obtained in the Houston-Galveston metropolitan area during the TEXAQS 2000 field campaign captured four days in which localized ozone levels of near 200 ppbv were observed. Analysis of individual petrochemical industrial sources near Houston has shown that these facilities can emit large amounts of highly reactive hydrocarbons and NOx to the atmosphere resulting in rapid and efficient ozone formation downwind. Simultaneous, in situ observations of CO, CO2, NO, NO2, NOy, HNO3, O3, SO2, HCHO, and reactive hydrocarbons along with meteorological data suggest that the major ozone exceedences are (1) consistently associated with the VOC and NOx emissions from the large density of petrochemical industrial sources located along the Houston ship channel, (2) observed under a variety of meteorological conditions, and (3) not consistently captured by the network of ground-based ozone monitors in the Houston area.

  6. Tropospheric ozone in the vicinity of the ozone hole: 1987 Airborne Antarctic Ozone Experiment

    SciTech Connect

    Gregory, G.L.; Warren, L.S. ); Hypes, W.D. ); Tuck, A.F.; Kelly, K.K. ); Krueger, A.J. )

    1989-11-30

    Tropospheric ozone measurements over Antarctica aboard the NASA DC-8 aircraft are summarized. As part of the August/September 1987 Airborne Antarctic Ozone Experiment, the aircraft flew 13 missions covering a latitude of 53{degree}-90{degree}S, at altitudes to 13 km. Ozone mixing ratios as high as several hundred parts per billion by volume (ppbv) were measured, but in all cases these ratios were observed in pockets or patches of upper atmospheric air. These pockets were observed both in the vicinity of and away from the location of the ozone hole. At times, and as a result of these pockets, the ozone levels at the flight altitude of the aircraft, as averaged beneath the boundaries of the stratospheric ozone hole, were 2-3 times higher than background tropospheric values. The data suggest that the ozone-rich air seldom penetrated below about 9-km altitude. Background ozone values in the surrounding troposphere were typically in the range of 20-50 ppbv. Correlation of tropospheric ozone observations with the boundaries of the ozone hole differed during the experiment. During the early flights (August 28 through September 2), encounters with ozone-rich air were limited and background tropospheric ozone (at the flight altitude) appeared to decrease beneath the hole. For many of the later flights, and as the hole deepened, the reverse was noted, in that ozone-rich air was frequently observed in the vicinity of the hole and, as noted earlier, average ozone at the flight altitude was frequently higher than background values.

  7. 16 CFR 260.11 - Ozone-safe and ozone-friendly claims.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... friendly to, the ozone layer or the atmosphere. Example 1: A product is labeled “ozone-friendly.” The claim... 16 Commercial Practices 1 2013-01-01 2013-01-01 false Ozone-safe and ozone-friendly claims. 260.11... THE USE OF ENVIRONMENTAL MARKETING CLAIMS § 260.11 Ozone-safe and ozone-friendly claims. It...

  8. 16 CFR 260.11 - Ozone-safe and ozone-friendly claims.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... friendly to, the ozone layer or the atmosphere. Example 1: A product is labeled “ozone-friendly.” The claim... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Ozone-safe and ozone-friendly claims. 260.11... THE USE OF ENVIRONMENTAL MARKETING CLAIMS § 260.11 Ozone-safe and ozone-friendly claims. It...

  9. Solving the Tulsa ozone problem

    SciTech Connect

    Wagner, K.K.; Wilson, J.D.; Gibeau, E.

    1998-12-31

    Local governments and interested parties in Tulsa, Oklahoma are planning actions to keep Tulsa in compliance with the ozone ambient air quality standard. Based on recent data Tulsa exceeds the new eight hour average national ambient air quality standard for ozone and occasionally exceeds the previous one hour standard. Currently, Tulsa is in attainment of the former one-hour ozone standard. The first planning step is to integrate the existing information about Tulsa`s ozone problem. Prior studies of Tulsa ozone are reviewed. Tulsa`s recent air quality and meteorological monitoring are evaluated. Emission inventory estimates are assessed. Factors identified with Tulsa`s ozone problem are the transport of ozone and precursor gases, a possible role for biogenic emissions, and a simplistic ozone forecasting method. The integration of information found that current air quality and meteorological monitoring is meager. Observations of volatile organic compounds and NO{sub y} are absent. Prior intensive studies in 1977 and 1985 are more than ten years old and lack relevance to today`s problem. Emission inventory estimates are scarce and uncertain. The current knowledge base was judged inadequate to properly characterize the present ozone problem. Actions are recommended to enlarge the information base to address Tulsa`s ozone problem.

  10. CFCS and the ozone layer.

    PubMed

    Hayman, G D

    1997-05-01

    Ozone is an important constituent of the atmosphere. Ozone forms a distinct layer in the lower stratosphere known as the ozone layer. The ozone layer acts as a fragile shield because it protects man and other life forms from exposure to harmful short-wavelength ultraviolet (UV) radiation. The agents, particularly chemical, which affect the amount of ozone present in the atmosphere have been a source of concern for more than 20 years. This has been reinforced by the dramatic decline of stratospheric ozone levels first measured in Antarctica and now apparent worldwide. The combination of routine measurements of ozone depletion, careful laboratory studies and mathematical modelling of ozone in the atmosphere, has demonstrated that the reactive fragments produced when chlorofluorocarbons (CFCs), halons and other halogenated compounds break down in the stratosphere are responsible for the ozone loss. As CFCs have widespread and sometimes apparently essential uses in modern society, there has been an intense effort to develop safe, effective replacements which have a negligible or much smaller impact on the environment. The Montreal Protocol, signed by over 140 nations, has been implemented to control and phase out the chemical compounds responsible for ozone loss. PMID:9519506

  11. Precision ozone calibration system based on vapor pressures of ozone

    NASA Technical Reports Server (NTRS)

    Mauersberger, K.; Hanson, D.; Morton, J.

    1987-01-01

    A precision ozone calibration system for stratospheric research has been developed and evaluated. Vapor pressures above solid ozone are mixed with a carrier gas (N2) to produce stratospheric ozone mixing ratios at total pressures of 1 to cover 20 torr. The uncertainty in the ozone mixing ratios is approximately + or - 1.5 percent, the stability of ozone is + or - 0.3 percent. Experiments to be calibrated may sample the gas mixture over a wide range of flow rates; the maximum throughput of gas with corrections of less than 1 percent to ozone is about 200 torr 1/min. A mass spectrometer system continuously monitors the purity and stability of the N2-O3 gas mixture.

  12. Innovation for maintenance technology improvements

    NASA Technical Reports Server (NTRS)

    Shives, T. R. (Editor); Willard, W. A. (Editor)

    1982-01-01

    A group of 34 submitted entries (32 papers and 2 abstracts) from the 33rd meeting of the Mechanical Failures Prevention Group whose subject was maintenance technology improvement through innovation. Areas of special emphasis included maintenance concepts, maintenance analysis systems, improved maintenance processes, innovative maintenance diagnostics and maintenance indicators, and technology improvements for power plant applications.

  13. Balloonborne ozone and aerosol measurements in the antarctic ozone hole

    SciTech Connect

    Hofmann, D.J.; Harder, J.W.; Rolf, S.R.; Rosen, J.M. )

    1987-01-01

    The National Ozone Expedition (NOZE) was mounted in 1986 using winter fly-in flights to McMurdo Station in August, which is approximately the time the ozone reduction begins. The University of Wyoming Atmospheric Physics group participated in this expedition through balloonborne measurements of the vertical distribution of ozone and aerosol particles. Between 24 August and 6 November, 33 ozone soundings, 6 aerosol sounding, and 3 condensation nuclei soundings were conducted using polyethylene balloons which were able to penetrate the cold (< {minus}80C) antarctic stratosphere. The authors summarize these results here.

  14. Ozone and ozone byproducts in the cabins of commercial aircraft.

    PubMed

    Weisel, Clifford; Weschler, Charles J; Mohan, Kris; Vallarino, Jose; Spengler, John D

    2013-05-01

    The aircraft cabin represents a unique indoor environment due to its high surface-to-volume ratio, high occupant density, and the potential for high ozone concentrations at cruising altitudes. Ozone was continuously measured and air was sampled on sorbent traps, targeting carbonyl compounds, on 52 transcontinental U.S. or international flights between 2008 and 2010. The sampling was predominantly on planes that did not have ozone scrubbers (catalytic converters). Peak ozone levels on aircraft without catalytic convertors exceeded 100 ppb, with some flights having periods of more than an hour when the ozone levels were >75 ppb. Ozone was greatly reduced on relatively new aircraft with catalytic convertors, but ozone levels on two flights whose aircraft had older convertors were similar to those on planes without catalytic convertors. Hexanal, heptanal, octanal, nonanal, decanal, and 6-methyl-5-hepten-2-one (6-MHO) were detected in the aircraft cabin at sub- to low ppb levels. Linear regression models that included the log transformed mean ozone concentration, percent occupancy, and plane type were statistically significant and explained between 18 and 25% of the variance in the mixing ratio of these carbonyls. Occupancy was also a significant factor for 6-MHO, but not the linear aldehydes, consistent with 6-MHO's formation from the reaction between ozone and squalene, which is present in human skin oils. PMID:23517299

  15. Ozone Risk Assessment Utilities

    1999-08-10

    ORAMUS is a user-friendly, menu-driven software system that calculates and displays user-selected risk estimates for health effects attributable to short-term exposure to tropospheric ozone. Inputs to the risk assessment are estimates of exposure to ozone and exposure-response relationships to produce overall risk estimates in the form of probability distributions. Three fundamental models are included: headcount risk, benchmark risk, and hospital admissions. Exposure-response relationships are based on results of controlled human exposure studies. Exposure estimates aremore » based on the EPA''s probabilistic national ambient air quality standards (NAAQS) exposure model, pNEM/Osub3, which simulates air quality associated with attainment of alternative NAAQS. Using ORAMUS, risk results for 27 air quality scenarios, air quality in 9 urban areas, 33 health endpoints, and 4 chronic health endpoints can be calculated.« less

  16. The Antarctic ozone hole

    SciTech Connect

    Stolarski, R.S.

    1988-01-01

    Because the effects are so serious, many investigators have been racing to determine the causes of the hole which develops each southern spring within the polar vortex, an isolated air mass that circulates around the South Pole during a large part of the year. This paper reviews two of the foremost theories for this ozone hole. Mechanisms of the pollution theory, which proposes that the cause is chlorofluorocarbons and nitrogen oxides in the atmosphere, are reviewed. The second theory proposes a natural shift in the air movements that transport ozone-rich air into the polar stratosphere during the southern spring as the cause. Current data suggest both theories are correct, but data are considered inconclusive.

  17. Industrial Maintenance Strategies

    SciTech Connect

    Sajjad Akbar

    2006-07-01

    Industrial plants have become more complex due to technological advancement. This has made the task of maintenance more difficult. The maintenance costs in terms of resources and downtime loss are so high that maintenance function has become a critical factor in a plant's profitability. Industry should devote as much forethought to the management of maintenance function as to production. Maintenance has grown from an art to a precise, technical engineering science. Planning, organizing scheduling and control of maintenance using modern techniques pays dividends in the form of reduced costs and increased reliability. The magnitude and the dimension of maintenance have multiplied due to development in the engineering technologies. Production cost and capacities are directly affected by the breakdown time. Total operating cost including the maintenance cost plays an important role in replacement dimension. The integrated system approach would bring forth the desired results of high maintenance standards. The standards once achieved and sustained, would add to the reliability of the plan and relieve heavy stresses and strains on the engineering logistic support. (author)

  18. Ozonated olive oils and the troubles.

    PubMed

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  19. Ozone, Air Quality, and Asthma (For Parents)

    MedlinePlus

    ... found in both the Earth's upper and lower atmospheres. The protective ozone in the upper atmosphere is very different from the harmful ozone in the lower atmosphere. Ozone that exists naturally 10 to 30 miles ( ...

  20. Ozonated olive oils and the troubles

    PubMed Central

    Uysal, Bulent

    2014-01-01

    One of the commonly used methods for ozone therapy is ozonated oils. Most prominent type of used oils is extra virgin olive oil. But still, each type of unsaturated oils may be used for ozonation. There are a lot of wrong knowledge on the internet about ozonated oils and its use as well. Just like other ozone therapy studies, also the studies about ozone oils are inadequate to avoid incorrect knowledge. Current data about ozone oil and its benefits are produced by supplier who oversees financial interests and make misinformation. Despite the rapidly increasing ozone oil sales through the internet, its quality and efficacy is still controversial. Dozens of companies and web sites may be easily found to buy ozonated oil. But, very few of these products are reliable, and contain sufficiently ozonated oil. This article aimed to introduce the troubles about ozonated oils and so to inform ozonated oil users. PMID:26401346

  1. Protecting beans from ozone

    SciTech Connect

    Pierce, R.

    1983-03-01

    A chemical treatment to protect navy beans from ozone damage increased yields by an average of more than 20% in 3 years of tests. An experimental antioxidant chemical, EDU, made by the DuPont company was tested as soil applications and sprays on several varieties and under a variety of soil and planting conditions. The average yield increases were between 16 and 24%. Chemical treatment also increased snap bean pod production by 12%.

  2. Ozone attainment: A different perspective

    SciTech Connect

    Beck, W.B. )

    1988-01-01

    Recent attention on the ozone non-attainment issue has been focused on Washington. Both Congress and the EPA have made efforts at addressing the post-1987 crisis in the many non-attainment areas. In contrast to the political activity, this paper presents some interesting technical perspectives on ozone attainment for many areas of the U.S.. Issues such as transport, climate and natural ozone sources are discussed in the context of exceedance frequency for several geographical areas of the country.

  3. Another deep Antarctic ozone hole

    SciTech Connect

    Kerr, R.A.

    1990-10-19

    Again in 1990, drastic depletion of stratospheric ozone over the South Pole has been measured, in August 140 Dobson units, far below the 220 Dobson units typically seen over Antarctica. This extensive destruction of ozone is determined to be brought about by sunshine acting in combination with the chlorine released from chlorofluorohydrocarbons (CFCs) by icy stratospheric clouds. It is concluded that CFC concentrations have now reached a level that will almost totally destroy the ozone in the lower stratosphere in most years.

  4. Ozone transport commission developments

    SciTech Connect

    Joyce, K.M.

    1995-08-01

    On September 27, 1994, the states of the Ozone Transport Commission (OTC) signed an important memorandum of understanding (MOU) agreeing to develop a regional strategy for controlling stationary sources of nitrogen oxide emissions. Specifically, the states of the Ozone Transport Region, OTR, agreed to propose regulations for the control of NOx emissions from boilers and other indirect heat exchangers with a maximum gross heat input rate of at least 250 million BTU per hour. The Ozone Transport Region was divided into Inner, Outer and Northern Zones. States in the Outer Zone agreed to reduce NOx emissions by 55%. States in the Inner Zone agreed to reduce NOx emissions 65%. Facilities in both zones have the option to emit NOx at a rate no greater than 0.2 pounds per million Btu by May 1, 1999. This option provides fairness for the gas-fired plants which already have relatively low NOx emissions. Additionally, States in the Inner and Outer Zones agreed to reduce their NOx emissions by 75% or to emit NOx at a rate no greater than 0.15 pounds per million BTU by May 1, 2003. The Northern Zone States agree to reduce their rate of NOx emissions by 55% from base year levels by May 1, 2003, or to emit NOx at a rate no greater than 0.2 pounds per million BTU. As part of this MOU, States also agreed to develop a regionwide trading mechanism to provide a cost-effective mechanism for implementing the reductions.

  5. Ozone measurement systems improvements studies

    NASA Technical Reports Server (NTRS)

    Thomas, R. W.; Guard, K.; Holland, A. C.; Spurling, J. F.

    1974-01-01

    Results are summarized of an initial study of techniques for measuring atmospheric ozone, carried out as the first phase of a program to improve ozone measurement techniques. The study concentrated on two measurement systems, the electro chemical cell (ECC) ozonesonde and the Dobson ozone spectrophotometer, and consisted of two tasks. The first task consisted of error modeling and system error analysis of the two measurement systems. Under the second task a Monte-Carlo model of the Dobson ozone measurement technique was developed and programmed for computer operation.

  6. Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China.

    PubMed

    Zhao, Heng; Wang, Shanshan; Wang, Wenxin; Liu, Rui; Zhou, Bin

    2015-01-01

    Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations. PMID:26121146

  7. Investigation of Ground-Level Ozone and High-Pollution Episodes in a Megacity of Eastern China

    PubMed Central

    Zhao, Heng; Wang, Shanshan; Wang, Wenxin; Liu, Rui; Zhou, Bin

    2015-01-01

    Differential Optical Absorption Spectroscopy (DOAS) was used for the long-term observation of ground-level ozone (O3) from March 2010 to March 2013 over Shanghai, China. The 1-hour average concentration of O3 was 27.2 ± 17.0 ppbv. O3 level increased during spring, reached the peak in late spring and early summer, and then decreased in autumn and finally dropped to the bottom in winter. The highest monthly average O3 concentration in June (41.1 ppbv) was nearly three times as high as the lowest level recorded in December (15.2 ppbv). In terms of pollution episodes, 56 hourly samples (on 14 separate days) in 2010 exceeded the 1-hour ozone limit of 200 μg/m3 specified by the Grade II of the Chinese Ambient Air Quality Standards (CAAQS, revised GB 3095-2012). Utilizing the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, the primary contribution to high ozone days (HODs) was identified as the regional transportation of volatile organic compounds (VOC) and high concentrations of O3 from the chemical industrial zone in the Jinshan district of Shanghai. HODs showed higher concentrations of HONO and NO2 than non-episode conditions, implying that HONO at high concentration during HODs was capable of increasing the O3 concentration. The photolysis rate of HONO was estimated, suggesting that the larger number of OH radicals resulting from high concentrations of HONO have a considerable impact on ozone concentrations. PMID:26121146

  8. New ozone standard in the U.S.A. applied to Mexico City metropolitan air quality

    SciTech Connect

    Bravo A, H. Sosa E, R.; Sanchez A, P.; Jaimes P, M.

    1998-12-31

    The air quality of the Mexico City Metropolitan Zone (MCMZ) is recognized as one of the worst air pollution problems in the world. At the present, ozone is the most critical atmospheric pollutant in the area. According to the air quality data of the monitoring station at the University of Mexico, the ozone problem started in 1986. Mexican Ozone Air Quality Standard (MOAQS) specifies that a concentration of 0.11 ppm must not be exceeded more than one hour a day, one day a year in the term of three years. The Official Air Quality Data (RAMA) from 19 monitoring stations in the MCMZ coincides with the University station`s data, presenting the same atmospheric pollution problem. In the most critical sites the MOAQS is exceeded more than 1,300 hours in a year. Now, the Environmental Protection Agency of the United States (EPA) is working to establish the new ozone standard. EPA is setting the standard at 0.08 ppm on an average of 8 hours, considering the 3 year average of the annual 4th highest daily maximum 8 hour ozone concentration. The purpose of this paper is to present the tendency and comparison between two standards (1 hour and 8 hours) of the ozone concentrations in the MCMZ, since 1986 to 1996. Although Mexico does not yet have the 8 hour standard for ozone, it is very important to analyze the existing air quality data with this new standard. In this way the aim is to protect the health of more than 20 million inhabitants in the MCMZ.

  9. The Impact of Climate Change on Ozone-Related Mortality in Sydney

    PubMed Central

    Physick, William; Cope, Martin; Lee, Sunhee

    2014-01-01

    Coupled global, regional and chemical transport models are now being used with relative-risk functions to determine the impact of climate change on human health. Studies have been carried out for global and regional scales, and in our paper we examine the impact of climate change on ozone-related mortality at the local scale across an urban metropolis (Sydney, Australia). Using three coupled models, with a grid spacing of 3 km for the chemical transport model (CTM), and a mortality relative risk function of 1.0006 per 1 ppb increase in daily maximum 1-hour ozone concentration, we evaluated the change in ozone concentrations and mortality between decades 1996–2005 and 2051–2060. The global model was run with the A2 emissions scenario. As there is currently uncertainty regarding a threshold concentration below which ozone does not impact on mortality, we calculated mortality estimates for the three daily maximum 1-hr ozone concentration thresholds of 0, 25 and 40 ppb. The mortality increase for 2051–2060 ranges from 2.3% for a 0 ppb threshold to 27.3% for a 40 ppb threshold, although the numerical increases differ little. Our modeling approach is able to identify the variation in ozone-related mortality changes at a suburban scale, estimating that climate change could lead to an additional 55 to 65 deaths across Sydney in the decade 2051–2060. Interestingly, the largest increases do not correspond spatially to the largest ozone increases or the densest population centres. The distribution pattern of changes does not seem to vary with threshold value, while the magnitude only varies slightly. PMID:24419047

  10. The impact of climate change on ozone-related mortality in Sydney.

    PubMed

    Physick, William; Cope, Martin; Lee, Sunhee

    2014-01-01

    Coupled global, regional and chemical transport models are now being used with relative-risk functions to determine the impact of climate change on human health. Studies have been carried out for global and regional scales, and in our paper we examine the impact of climate change on ozone-related mortality at the local scale across an urban metropolis (Sydney, Australia). Using three coupled models, with a grid spacing of 3 km for the chemical transport model (CTM), and a mortality relative risk function of 1.0006 per 1 ppb increase in daily maximum 1-hour ozone concentration, we evaluated the change in ozone concentrations and mortality between decades 1996-2005 and 2051-2060. The global model was run with the A2 emissions scenario. As there is currently uncertainty regarding a threshold concentration below which ozone does not impact on mortality, we calculated mortality estimates for the three daily maximum 1-hr ozone concentration thresholds of 0, 25 and 40 ppb. The mortality increase for 2051-2060 ranges from 2.3% for a 0 ppb threshold to 27.3% for a 40 ppb threshold, although the numerical increases differ little. Our modeling approach is able to identify the variation in ozone-related mortality changes at a suburban scale, estimating that climate change could lead to an additional 55 to 65 deaths across Sydney in the decade 2051-2060. Interestingly, the largest increases do not correspond spatially to the largest ozone increases or the densest population centres. The distribution pattern of changes does not seem to vary with threshold value, while the magnitude only varies slightly. PMID:24419047

  11. Halt Runaway Maintenance Costs.

    ERIC Educational Resources Information Center

    Trotter, Andrew

    1988-01-01

    To keep expensive computer software and hardware functioning requires good housekeeping, some protective equipment, ground rules, and supervision. Schools can arrange microcomputer maintenance through service agreements with computer manufacturers, pay-as-you-go service from local computer stores, or setting up their own maintenance and repair…

  12. Fixing Maintenance Productivity.

    ERIC Educational Resources Information Center

    Fickes, Michael

    2003-01-01

    Describes how one university's facility managers use Nextel communications technology in conjunction with a Famis Software maintenance management system to improve the productivity of its maintenance technicians. The system uses a wireless Internet connection to automate the flow of work order information to and from technicians. The key to these…

  13. Maintenance of School Gymnasiums.

    ERIC Educational Resources Information Center

    Finchum, R. N.

    1965-01-01

    Procedures are suggested that may be helpful to those responsible for the operation and maintenance of school buildings and gymnasiums. Most schools with gymnasiums utilize them for both instructional and sports purposes. Maintenance of the multipurpose gym are discussed under four subject areas--(1) floors, (2) lighting, (3) sanitation, and (4)…

  14. Maintenance Trades Guidelines

    ERIC Educational Resources Information Center

    Weidner, Theodore J.

    2008-01-01

    In 2002, APPA published "Maintenance Staffing Guidelines for Educational Facilities," the first building maintenance trades staffing guideline designed to assist educational facilities professionals with their staffing needs. addresses how facilities professionals can determine the appropriate size and mix of their organization. Contents include…

  15. Maximizing Hard Floor Maintenance.

    ERIC Educational Resources Information Center

    Steger, Michael

    2000-01-01

    Explains the maintenance options available for hardwood flooring that can help ensure long life cycles and provide inviting spaces. Developing a maintenance system, knowing the type of traffic that the floor must endure, using entrance matting, and adhering to manufacturers guidelines are discussed. Daily, monthly or quarterly, and long-term…

  16. Observations of the Temperature Dependent Response of Ozone to NOx Reductions in an Urban Plume

    SciTech Connect

    LaFranchi, B W; Goldstein, A H; Cohen, R C

    2011-01-25

    Observations of NO{sub x} in the Sacramento, CA region show that mixing ratios decreased by 30% between 2001 and 2008. Here we use an observation-based method to quantify net ozone production rates in the outflow from the Sacramento metropolitan region and examine the O{sub 3} decrease resulting from reductions in NO{sub x} emissions. This observational method does not rely on assumptions about detailed chemistry of ozone production, rather it is an independent means to verify and test these assumptions. We use an instantaneous steady-state model as well as a detailed 1-D plume model to aid in interpretation of the ozone production inferred from observations. In agreement with the models, the observations show that early in the plume, the NO{sub x} dependence for O{sub x} (O{sub x} = O{sub 3}+NO{sub 2}) production is strongly coupled with temperature, suggesting that temperature dependent biogenic VOC emissions can drive O{sub x} production between NO{sub x}-limited and NO{sub x}-suppressed regimes. As a result, NO{sub x} reductions were found to be most effective at higher temperatures over the 7 year period. We show that violations of the California 1-hour O{sub 3} standard (90 ppb) in the region have been decreasing linearly with decreases in NO{sub x} (at a given temperature) and predict that reductions of NO{sub x} concentrations (and presumably emissions) by an additional 30% (relative to 2007 levels) will eliminate violations of the state 1 hour standard in the region. If current trends continue, a 30% decrease in NO{sub x} is expected by 2012, and an end to violations of the 1 hour standard in the Sacramento region appears to be imminent.

  17. Comparison of satellite measurements of ozone and ozone trends

    SciTech Connect

    Rusch, D.W.; Clancy, R.T.; Bhartia, P.K. |

    1994-10-01

    Measurements of ozone retrieved from satellite instruments over the 1979-1991 period are compared. The instruments used are the total ozone mapping spectrometer (TOMS), the solar backscattered ultraviolet experiment (SBUV), and stratospheric aerosol and gas experiments (SAGE) I and II. Although there is good agreement between the absolute densities of ozone as measured by the various instruments, the long-term changes (1979-1990) disagree sharply as a function of pressure and in the integrated ozone amount. In the upper stratosphere, SBUV trends are negative with maximum values of about -1.5%/year at high latitudes. Combined SAGE I and II trends are slightly positive in this region and peak near 0.5%/year at equatorial latitudes. In the lower stratosphere, SBUV trends reflect small decreases in ozone, generally less than -0.4%/year except at high southern latitudes where the trends rearch values of approximately -1.5%/year. SAGE ozone trends exhibit large decreases particularly in the equatorial regions where decreases of 3-6%/year are seen at pressures between 60 and 90 mbar. At higher latitudes, SAGE trends are more comparable to SBUV trends in the lower stratosphere. Total ozone trends from TOMS and SBUV agree within their uncertainties. Near-zero trends are indicated at low latitudes, and larger, negative trends (approximately -0.5%/year) are indicated near the poles. The SAGE column ozone trends depend upon the base level altitude of integration but do not exhibit a strong latitude dependence.

  18. Table Mountain ozone intercomparison: Brewer ozone spectrophotometer Umkehr observations

    SciTech Connect

    McElroy, C.T.; Kerr, J.B.

    1995-05-20

    The authors present the result of ozone column measurements, and vertical profiles, derived from Brewer ozone spectrophotometer measurements, in conjunction with the Umkehr technique. The Umkehr results agreed within 15% with the average measurments of this campaign between 20 and 40 km altitude. When restricted to the altitude range of 24 to 40 km the agreement was within about 5%.

  19. Ultraviolet Radiation and Stratospheric Ozone

    NASA Technical Reports Server (NTRS)

    Stolarski, R.

    2003-01-01

    Ultraviolet radiation from the sun produces ozone in the stratosphere and it participates in the destruction of ozone. Absorption of solar ultraviolet radiation by ozone is the primary heating mechanism leading to the maximum in temperature at the stratopause. Variations of solar ultraviolet radiation on both the 27-day solar rotation period and the 11-year solar cycle affect ozone by several mechanisms. The temperature and ozone in the upper stratosphere respond to solar uv variations as a coupled system. An increase in uv leads to an increase in the production of ozone through the photolysis of molecular oxygen. An increase in uv leads to an increase in temperature through the heating by ozone photolysis. The increase in temperature leads to a partially-offsetting decrease in ozone through temperature-dependent reaction rate coefficients. The ozone variation modulates the heating by ozone photolysis. The increase in ozone at solar maximum enhances the uv heating. The processes are understood and supported by long-term data sets. Variation in the upper stratospheric temperatures will lead to a change in the behavior of waves propagating upward from the troposphere. Changes in the pattern of wave dissipation will lead to acceleration or deceleration of the mean flow and changes in the residual or transport circulation. This mechanism could lead to the propagation of the solar cycle uv variation from the upper stratosphere downward to the lower stratosphere. This process is not well-understood and has been the subject of an increasing number of model studies. I will review the data analyses for solar cycle and their comparison to model results.

  20. Comparative Effects of Gamma Irradiation and Ozone Treatment on Hygienic Quality of Korean Red Ginseng Powder

    NASA Astrophysics Data System (ADS)

    Byun, Myung-Woo; Yook, Hong-Sun; Kang, Il-Jun; Chung, Cha-Kwon; Kwon, Joong-Ho; Choi, Kang-Ju

    1998-06-01

    For the purpose of improving hygienic quality of Korean red ginseng powder, the comparative effects of gamma irradiation and ozone treatment on the microbial and physicochemical properties were investigated. Gamma irradiation at 7.5 kGy resulted in sterilization of total aerobic bacteria, molds and coliforms below detective levels, while ozone treatment for 8 hours up to 18 ppm did not sufficiently eliminate the microorganisms of the red ginseng powder. Physicochemical properties including compositions of the red ginseng saponin (ginsenosides) and fatty acids, pH and hydrogen doanting activity were not significantly changed by gamma irradiation, whereas, ozone treatment caused significant changes in fatty acid compositions, TBA value, pH, acidity and hydrogen donating activity. The results from this study led us to conclude that gamma irradiation was more effective than ozone treatment both for the improvement of hygienic quality and for the maintenance of physicochemical quality of red ginseng powder.

  1. Unequivocal detection of ozone recovery in the Antarctic Ozone Hole through significant increases in atmospheric layers with minimum ozone

    NASA Astrophysics Data System (ADS)

    de Laat, Jos; van Weele, Michiel; van der A, Ronald

    2015-04-01

    An important new landmark in present day ozone research is presented through MLS satellite observations of significant ozone increases during the ozone hole season that are attributed unequivocally to declining ozone depleting substances. For many decades the Antarctic ozone hole has been the prime example of both the detrimental effects of human activities on our environment as well as how to construct effective and successful environmental policies. Nowadays atmospheric concentrations of ozone depleting substances are on the decline and first signs of recovery of stratospheric ozone and ozone in the Antarctic ozone hole have been observed. The claimed detection of significant recovery, however, is still subject of debate. In this talk we will discuss first current uncertainties in the assessment of ozone recovery in the Antarctic ozone hole by using multi-variate regression methods, and, secondly present an alternative approach to identify ozone hole recovery unequivocally. Even though multi-variate regression methods help to reduce uncertainties in estimates of ozone recovery, great care has to be taken in their application due to the existence of uncertainties and degrees of freedom in the choice of independent variables. We show that taking all uncertainties into account in the regressions the formal recovery of ozone in the Antarctic ozone hole cannot be established yet, though is likely before the end of the decade (before 2020). Rather than focusing on time and area averages of total ozone columns or ozone profiles, we argue that the time evolution of the probability distribution of vertically resolved ozone in the Antarctic ozone hole contains a better fingerprint for the detection of ozone recovery in the Antarctic ozone hole. The advantages of this method over more tradition methods of trend analyses based on spatio-temporal average ozone are discussed. The 10-year record of MLS satellite measurements of ozone in the Antarctic ozone hole shows a

  2. Exposure to ozone reduces postharvest quality loss in red and green chilli peppers.

    PubMed

    Glowacz, Marcin; Rees, Deborah

    2016-11-01

    The effect of continuous exposure to ozone at 0.45, 0.9 and 2μmolmol(-1) on quality changes during the storage of red and green chilli peppers at 10°C was investigated. Ozone at 0.45 and 0.9μmolmol(-1) reduced disease incidence in red peppers, with no further benefits at 2μmolmol(-1). Ozone at 0.9μmolmol(-1) reduced weight loss during storage and improved firmness maintenance. Skin colour was bleached in red peppers exposed to ozone at 2μmolmol(-1), and in green ones at all tested doses. Total phenolic content was not affected by ozone but antioxidant activity was reduced in green chilli peppers exposed to ozone at 2μmolmol(-1), due to lower ascorbic acid content in those samples. Ozone at 0.9μmolmol(-1) extended the shelf-life of chilli peppers. PMID:27211651

  3. IMPACT OF OZONE ON VEGETATION

    EPA Science Inventory

    Visible injury on vegetation is one of the earliest and most obvious manifestations of ozone injury. However, ozone effects are not limited to visible injury; impacts range from reduced plant growth, decreased yield, changes in crop quality and alterations in susceptibility to ab...

  4. Rocket ozone sounding network data

    NASA Technical Reports Server (NTRS)

    Wright, D. U.; Krueger, A. J.; Foster, G. M.

    1978-01-01

    During the period December 1976 through February 1977, three regular monthly ozone profiles were measured at Wallops Flight Center, two special soundings were taken at Antigua, West Indies, and at the Churchill Research Range, monthly activities were initiated to establish stratospheric ozone climatology. This report presents the data results and flight profiles for the period covered.

  5. IMPROVED TECHNIQUES FOR RESIDUAL OZONE

    EPA Science Inventory

    Eight analytical methods for the determination of residual ozone in water are evaluated. Four are iodometric methods based on the reduction of ozone by iodide ion: the iodometric method, the amperometric method, the arsenic (III) back titration method, and the N, N-diethyl-p-phen...

  6. Simplified ozone detection by chemiluminescence

    NASA Technical Reports Server (NTRS)

    Conway, E. J.; Rogowski, R. S.; Richards, R. R.

    1977-01-01

    Ozone is detected by film coated with solid, such as rubrene, that reacts with ozone to degree proportional to concentration in sample gas. Gas flow is stopped, and film is heated to produce light (chemiluminescence) in proportion to amount of reacted material on sensor.

  7. Plant responses to tropospheric ozone

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tropospheric ozone is the second most abundant air pollutant and an important component of the global climate change. Over five decades of research on the phytotoxicity of ozone in model plants systems, crop plants and forest trees have provided some insight into the physiological, biochemical and m...

  8. OZONE MULTI-YEAR PLAN

    EPA Science Inventory

    The tropospheric ozone research program addresses not only ozone, but other criteria pollutants such as SO2, nitrogen dioxide, carbon monoxide, and lead. It focuses on developing tools to help with implementation of National Ambient Air Quality Standards (NAAQS), such as improvin...

  9. Ozone Modeling Using Neural Networks.

    NASA Astrophysics Data System (ADS)

    Narasimhan, Ramesh; Keller, Joleen; Subramaniam, Ganesh; Raasch, Eric; Croley, Brandon; Duncan, Kathleen; Potter, William T.

    2000-03-01

    Ozone models for the city of Tulsa were developed using neural network modeling techniques. The neural models were developed using meteorological data from the Oklahoma Mesonet and ozone, nitric oxide, and nitrogen dioxide (NO2) data from Environmental Protection Agency monitoring sites in the Tulsa area. An initial model trained with only eight surface meteorological input variables and NO2 was able to simulate ozone concentrations with a correlation coefficient of 0.77. The trained model was then used to evaluate the sensitivity to the primary variables that affect ozone concentrations. The most important variables (NO2, temperature, solar radiation, and relative humidity) showed response curves with strong nonlinear codependencies. Incorporation of ozone concentrations from the previous 3 days into the model increased the correlation coefficient to 0.82. As expected, the ozone concentrations correlated best with the most recent (1-day previous) values. The model's correlation coefficient was increased to 0.88 by the incorporation of upper-air data from the National Weather Service's Nested Grid Model. Sensitivity analysis for the upper-air variables indicated unusual positive correlations between ozone and the relative humidity from 500 hPa to the tropopause in addition to the other expected correlations with upper-air temperatures, vertical wind velocity, and 1000-500-hPa layer thickness. The neural model results are encouraging for the further use of these systems to evaluate complex parameter cosensitivities, and for the use of these systems in automated ozone forecast systems.

  10. Rocket ozone sounding network data

    NASA Technical Reports Server (NTRS)

    Wright, D. U.; Krueger, A. J.; Foster, G. M.

    1979-01-01

    During the period March 1977 through May 1977, three regular monthly ozone profiles were measured at Wallops Flight Center and three regular monthly ozone profiles were measured at the Churchill Research Range. One additional flight was conducted at Wallops Flight Center in support of Nimbus 4 SBUV. Data results and flight profiles for the period covered are presented.

  11. Nonaqueous ozonation of vulcanized rubber

    DOEpatents

    Serkiz, Steven M.

    1999-01-01

    A process and resulting product is provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  12. Nonaqueous ozonation of vulcanized rubber

    SciTech Connect

    Serkiz, S.M.

    1999-12-07

    A process and resulting product are provided in which a solid particulate, such as vulcanized crumb rubber, has the surface functional groups oxidized by ozonation using a nonpolar solvent. The ozonation process renders the treated crumb rubber more suitable for use in new rubber formulations. As a result, larger loading levels of the treated crumb rubber can be used in new rubber mixtures.

  13. Scientific basis of the national ambient air quality standards for ozone: How do new discoveries and other concerns modify public health risks and expected benefits?

    SciTech Connect

    Vostal, J.J.; Heuss, J.M.; Paul, R.T.; Pezda, S.A.; Ball, J.C.; Wimette, H.J.

    1999-07-01

    The US EPA, in their recent review of the ozone NAAQS, acknowledged that substantial uncertainties exist with respect to the determination of public health risks due to ambient ozone. In particular, the uncertainties focus on considerable differences of opinion among scientists for the possible health effects at ozone levels near the new 8-hr. ozone National Air Quality Standard (NAAQS) of 0.08 ppm. Information on health or vegetation effects of low ambient ozone levels has been scarce, or extrapolated from studies using levels that are substantially above the new standard level. Uncertainties fall into three categories: (1) the extent of the adversity of public health endpoints; (2) the probability of adverse exposures; and (3) the impact of background levels on the achievability of the new standard. More specifically: (A) Public health effects of low ozone levels have thus far depended primarily on compromised pulmonary function as the biological endpoint of the greatest clinical significance. However, research data published after the standard was promulgated show that the ozone-induced effects represent more a physiological defense mechanism than an adverse effect of low ambient ozone concentrations. In light of these new findings, the alleged ozone action represents only a decline in pulmonary function test performance and not in the vital function of the lungs. This new interpretation not only eliminates the adverse character of pulmonary function decrements, but also largely modifies the proposed estimates of public health risks. (B) Public health risk assessments have indicated that even with compliance of the 1-hour ozone standard, the chances for US populations to encounter an adverse ozone exposure have been practically eliminated.

  14. Source attribution of tropospheric ozone

    NASA Astrophysics Data System (ADS)

    Butler, T. M.

    2015-12-01

    Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both

  15. Clathrate hydrates for ozone preservation.

    PubMed

    Muromachi, Sanehiro; Ohmura, Ryo; Takeya, Satoshi; Mori, Yasuhiko H

    2010-09-01

    We report the experimental evidence for the preservation of ozone (O(3)) encaged in a clathrate hydrate. Although ozone is an unstable substance and is apt to decay to oxygen (O(2)), it may be preserved for a prolonged time if it is encaged in hydrate cavities in the form of isolated molecules. This possibility was assessed using a hydrate formed from an ozone + oxygen gas mixture coexisting with carbon tetrachloride or xenon. Each hydrate sample was stored in an air-filled container at atmospheric pressure and a constant temperature in the range between -20 and 2 degrees C and was continually subjected to iodometric measurements of its fractional ozone content. Such chronological measurements and structure analysis using powder X-ray diffraction have revealed that ozone can be preserved in a hydrate-lattice structure for more than 20 days at a concentration on the order of 0.1% (hydrate-mass basis). PMID:20707330

  16. Ozone adsorption on carbon nanoparticles

    NASA Astrophysics Data System (ADS)

    Chassard, Guillaume; Gosselin, Sylvie; Visez, Nicolas; Petitprez, Denis

    2014-05-01

    Carbonaceous particles produced by incomplete combustion or thermal decomposition of hydrocarbons are ubiquitous in the atmosphere. On these particles are adsorbed hundreds of chemical species. Those of great concern to health are polycyclic aromatic hydrocarbons (PAHs). During atmospheric transport, particulate PAHs react with gaseous oxidants. The induced chemical transformations may change toxicity and hygroscopicity of these potentially inhalable particles. The interaction between ozone and carbon particles has been extensively investigated in literature. However ozone adsorption and surface reaction mechanisms are still ambiguous. Some studies described a fast catalytic decomposition of ozone initiated by an atomic oxygen chemisorption followed by a molecular oxygen release [1-3]. Others suggested a reversible ozone adsorption according to Langmuir-type behaviour [4,5]. The aim of this present study is a better understanding of ozone interaction with carbon surfaces. An aerosol of carbon nanoparticles was generated by flowing synthetic air in a glass tube containing pure carbon (primary particles < 50 nm), under magnetic stirring. The aerosol was then mixed with ozone in an aerosol flow tube. Ozone uptake experiments were performed with different particles concentrations with a fixed ozone concentration. The influence of several factors on kinetics was examined: initial ozone concentration, particle size (50 nm ≤ Dp ≤ 200 nm) and competitive adsorption (with probe molecule and water). The effect of initial ozone concentration was first studied. Accordingly to literature, it has been observed that the number of gas-phase ozone molecules lost per unit particle surface area tends towards a plateau for high ozone concentration suggesting a reversible ozone adsorption according to a Langmuir mechanism. We calculated the initial reaction probability between O3 and carbon particles.An initial uptake coefficient of 1.10-4 was obtained. Similar experiments were

  17. Powerful drivers for maintenance.

    PubMed

    Mason, Steve

    2013-10-01

    A UPS system is the central building block of a Power Continuity Plan in medical facilities, but such equipment requires careful maintenance to continue fulfilling its vital role in delivering power resilience, and avoid catastrophic downtime, and potentially tens of thousands of pounds in costs to rectify the issues caused by poor maintenance. In our latest technical guidance article, Steve Mason, MD at Bender UK, one of the leading providers of isolated power supplies, theatre control panels, UPS systems, and Steris surgical products, and a turnkey provider of solutions for safe handling of electrical power and advanced provision of critical care products, examines some of the issue surrounding UPS maintenance. PMID:24341105

  18. 35 state ozone transport region (OTAG) & ozone & PM NAAQS & regional HAZE FACA

    SciTech Connect

    Mathur, B.

    1996-11-01

    The activities of the 35 state ozone transport regions (OTAG) are summarized. Topics discussed include: the Chicago 15 percent plan; federal measures; VOC reduction goals; daily maximum ozone concentrations; ozone attainment demonstration policy; OTAG`s progress to date; significant upcoming activities; ozone transport assessment; model sensitivity analysis; FACA processes; and ozone, particulate matter, and regional haze implementation programs.

  19. Maintenance of Automated Library Systems.

    ERIC Educational Resources Information Center

    Epstein, Susan Baerg

    1983-01-01

    Discussion of the maintenance of both the software and hardware in an automated library system highlights maintenance by the vendor, contracts and costs, the maintenance log, downtime, and planning for trouble. (EJS)

  20. Options to accelerate ozone recovery: ozone and climate benefits

    NASA Astrophysics Data System (ADS)

    Daniel, J. S.; Fleming, E. L.; Portmann, R. W.; Velders, G. J. M.; Jackman, C. H.; Ravishankara, A. R.

    2010-08-01

    Hypothetical reductions in future emissions of ozone-depleting substances (ODSs) and N2O are evaluated in terms of effects on equivalent effective stratospheric chlorine (EESC), globally-averaged total column ozone, and radiative forcing through 2100. Due to the established success of the Montreal Protocol, these actions can have only a fraction of the impact on ozone depletion that regulations already in force have had. If all anthropogenic ODS and N2O emissions were halted beginning in 2011, ozone is calculated to be higher by about 1-2% during the period 2030-2100 compared to a case of no additional restrictions. Direct radiative forcing by 2100 would be about 0.23 W/m2 lower from the elimination of anthropogenic N2O emissions and about 0.005 W/m2 lower from the destruction of the chlorofluorocarbon (CFC) bank. Due to the potential impact of N2O on future ozone levels, we provide an approach to incorporate it into the EESC formulation, which is used extensively in ozone depletion analyses. The ability of EESC to describe total ozone changes arising from additional ODS and N2O controls is also quantified.

  1. Nitroaromatic hydrocarbon ozonation in water. 1: Single ozonation

    SciTech Connect

    Beltran, F.J.; Encinar, J.M.; Alonso, M.A.

    1998-01-01

    Single ozonation of two nitroaromatic hydrocarbons (nitrobenzene and 2,6-dinitrotoluene) under different experimental conditions (ozone feed rate, pH, temperature, hydroxyl radical scavengers) has been studied. The absence of hydroxyl radical scavengers, pHs 7--9, and temperatures below 30 C are optimum conditions for nitroaromatic removal. Due to the importance of hydroxyl radical reactions, removal rates in natural water are much lower than those observed in laboratory ultrapure water. Rate constants of the direct reaction between ozone and nitroaromatic hydrocarbons at 20 C have been found to be lower than 6 M{sup {minus}1} s{sup {minus}1}. More than 99% of nitroaromatic removal is due to hydroxyl radical oxidation. Single ozonation of nitroaromatics can then be classified as a real advanced oxidation technology. Nitrophenols, compounds very reactive toward ozone and hydroxyl radicals, and 2,6-dinitrobenzaldehyde, identified in the single ozonation of nitrobenzene and 2,6-dinitrotoluene, respectively, are some of the first intermediates of single ozonation.

  2. Total ozone changes in the 1987 Antarctic ozone hole

    NASA Technical Reports Server (NTRS)

    Krueger, Arlin J.; Schoeberl, Mark R.; Doiron, Scott D.; Sechrist, Frank; Galimore, Reginald

    1988-01-01

    The development of the Antarctic ozone minimum was observed in 1987 with the Nimbus 7 Total Ozone Mapping Spectrometer (TOMS) instrument. In the first half of August the near-polar (60 and 70 deg S) ozone levels were similar to those of recent years. By September, however, the ozone at 70 and 80 deg S was clearly lower than any previous year including 1985, the prior record low year. The levels continued to decrease throughout September until October 5 when a new record low of 109 DU was established at a point near the South Pole. This value is 29 DU less than the lowest observed in 1985 and 48 DU less than the 1986 low. The zonal mean total ozone at 60 deg S remained constant throughout the time of ozone hole formation. The ozone decline was punctuated by local minima formed away from the polar night boundary at about 75 deg S. The first of these, on August 15 to 17, formed just east of the Palmer Peninsula and appears to be a mountain wave. The second major minimum formed on September 5 to 7 again downwind of the Palmer Peninsula. This event was larger in scale than the August minimum and initiated the decline of ozone across the polar region. The 1987 ozone hole was nearly circular and pole centered for its entire life. In previous years the hole was perturbed by intrusions of the circumpolar maximum into the polar regions, thus causing the hole to be elliptical. The 1987 hole also remained in place until the end of November, a few days longer than in 1985, and this persistence resulted in the latest time for recovery to normal values yet observed.

  3. Is the Ozone Hole over Your Classroom?

    ERIC Educational Resources Information Center

    Cordero, Eugene C.

    2002-01-01

    Reports on a survey of first year university science students regarding their understanding of the ozone layer, ozone depletion, and the effect of ozone depletion on Australia. Suggests that better teaching resources for environmental issues such as ozone depletion and global warming are needed before improvements in student understanding can be…

  4. [Medical Equipment Maintenance Methods].

    PubMed

    Liu, Hongbin

    2015-09-01

    Due to the high technology and the complexity of medical equipment, as well as to the safety and effectiveness, it determines the high requirements of the medical equipment maintenance work. This paper introduces some basic methods of medical instrument maintenance, including fault tree analysis, node method and exclusive method which are the three important methods in the medical equipment maintenance, through using these three methods for the instruments that have circuit drawings, hardware breakdown maintenance can be done easily. And this paper introduces the processing methods of some special fault conditions, in order to reduce little detours in meeting the same problems. Learning is very important for stuff just engaged in this area. PMID:26904890

  5. Getting into Motorcycle Maintenance

    ERIC Educational Resources Information Center

    Mosher, Lynn

    1978-01-01

    This article tells how to start a high school course in motorcycle maintenance and includes names and addresses of some motorcycle manufacturers and a list of needed tools, equipment, and materials. (MF)

  6. Computerized Fleet Maintenance.

    ERIC Educational Resources Information Center

    Cataldo, John J.

    1985-01-01

    The Computerized Fleet Maintenance (CFM) program of a New York school district has major component areas of garage operation, vehicle replacement, and fuel consumption. CFM detects high expenditures and provides the rationale for bus replacement. (MLF)

  7. Carpet Maintenance Guide.

    ERIC Educational Resources Information Center

    Griffin, William R.

    1999-01-01

    Discusses ways to make carpet maintenance in schools easier and effective for keeping carpeted areas in schools attractive and long lasting. Covers cleaning tips for basic spills, ideas for staying on top of stains, and suggestions for eliminating odors. (GR)

  8. Automating Preventive Maintenance.

    ERIC Educational Resources Information Center

    Oshier, Michael J.

    1984-01-01

    Describes the following aspects of the State University of New York-Brockport's preventive maintenance computerization project: (1) software selection, (2) project implementation; and (3) problems and benefits of the system. (MCG)

  9. Care and Maintenance.

    ERIC Educational Resources Information Center

    Hampton, Carolyn H.; Hampton, Carol D.

    1979-01-01

    The classroom care and maintenance of terrestrial isopods is described. Includes illustrations of isopod external anatomy, a potato trap for collecting isopods, and a constructed habitat for raising isopods. (MA)

  10. Lunar robotic maintenance module

    NASA Technical Reports Server (NTRS)

    Ayres, Michael L.

    1988-01-01

    A design for a robotic maintenance module that will assist a mobile 100-meter lunar drill is introduced. The design considers the following areas of interest: the atmospheric conditions, actuator systems, power supply, material selection, weight, cooling system and operation.

  11. Woodwind Instrument Maintenance.

    ERIC Educational Resources Information Center

    Sperl, Gary

    1980-01-01

    The author presents a simple maintenance program for woodwind instruments which includes the care of tendon corks, the need for oiling keys, and methods of preventing cracks in woodwind instruments. (KC)

  12. Corona discharge influences ozone concentrations near rats.

    PubMed

    Goheen, Steven C; Gaither, Kari; Anantatmula, Shantha M; Mong, Gary M; Sasser, Lyle B; Lessor, Delbert

    2004-02-01

    Ozone can be produced by corona discharge either in dry air or when one electrode is submerged in water. Since ozone is toxic, we examined whether ozone production by corona near laboratory animals could reach levels of concern. Male rats were exposed to a corona discharge and the concentration of ozone produced was measured. The resulting concentration of ozone ranged from ambient levels to 250 ppb when animals were located 1 cm from a 10 kV source. Similar ozone concentrations were observed when a grounded water source was present. Possible explanations for, as well as concerns regarding, ozone production under these conditions are discussed. PMID:14735560

  13. When will Antarctic ozone begin to recover?

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-01-01

    Emissions of ozone-depleting substances have declined over recent decades, but it takes time for the ozone layer to recover. Regular measurements of ozone levels above the South Pole now stretch back 25 years. Hassler et al. analyzed these recorded ozone data to assess changes in ozone loss rates. Consistent with previous studies, they found that ozone loss rates have been stable over the past 15 years, neither increasing nor decreasing. However, they predict that, assuming future atmospheric dynamics are similar to today's, ozone loss rates will begin to decline noticeably between 2017 and 2021. (Journal of Geophysical Research-Atmospheres, doi:10.1029/2011JD016353, 2011)

  14. Unprecedented Arctic ozone loss in 2011.

    PubMed

    Manney, Gloria L; Santee, Michelle L; Rex, Markus; Livesey, Nathaniel J; Pitts, Michael C; Veefkind, Pepijn; Nash, Eric R; Wohltmann, Ingo; Lehmann, Ralph; Froidevaux, Lucien; Poole, Lamont R; Schoeberl, Mark R; Haffner, David P; Davies, Jonathan; Dorokhov, Valery; Gernandt, Hartwig; Johnson, Bryan; Kivi, Rigel; Kyrö, Esko; Larsen, Niels; Levelt, Pieternel F; Makshtas, Alexander; McElroy, C Thomas; Nakajima, Hideaki; Parrondo, Maria Concepción; Tarasick, David W; von der Gathen, Peter; Walker, Kaley A; Zinoviev, Nikita S

    2011-10-27

    Chemical ozone destruction occurs over both polar regions in local winter-spring. In the Antarctic, essentially complete removal of lower-stratospheric ozone currently results in an ozone hole every year, whereas in the Arctic, ozone loss is highly variable and has until now been much more limited. Here we demonstrate that chemical ozone destruction over the Arctic in early 2011 was--for the first time in the observational record--comparable to that in the Antarctic ozone hole. Unusually long-lasting cold conditions in the Arctic lower stratosphere led to persistent enhancement in ozone-destroying forms of chlorine and to unprecedented ozone loss, which exceeded 80 per cent over 18-20 kilometres altitude. Our results show that Arctic ozone holes are possible even with temperatures much milder than those in the Antarctic. We cannot at present predict when such severe Arctic ozone depletion may be matched or exceeded. PMID:21964337

  15. Brewer Umkehr ozone profile retrievals

    NASA Astrophysics Data System (ADS)

    Petropavlovskikh, I. V.; Disterhoft, P.; Lantz, K. O.; Bhartia, P. K.; McPeters, R. D.; Flynn, L. E.; Oltmans, S. J.; Johnson, B. J.; Stanek, M.

    2011-12-01

    The Dobson Umkehr network has been a key data set for stratospheric ozone trend calculations (WMO Ozone assessments) and has earned its place as a benchmark network for stratospheric ozone profile observations. The Umkehr data has also been used to provide a long-term reference to the merging of the satellite ozone records (MOD), estimate the seasonal influence of an 11-year solar signal in the vertical distribution of stratospheric ozone, and to assess the ability of several remote and in-situ sensing systems in capturing ozone variability. It was found that Dobson Umkehr measurement errors were often comparable to errors derived for satellite and ozone-sounding methods. The Umkehr measurements are also available from the Brewer spectrophotometers [McElroy et al., 1995]. In 2005, the Dobson Umkehr algorithm (UMK04) was modified to retrieve ozone profile data from Brewer Umkehr measurements taken at two spectral channels [Petropavlovskikh et al, 2011]. The PC version of the Brewer algorithm was developed by M. Stanek (IOC, Canada and Czech Republic Meteorological Institute) in close collaboration with I. Petropavlovskikh. It was implemented at the NEUBrew network for operational processing of Umkehr data retrieved daily for all operational sites. The most recently developed Brewer ozone retrieval algorithm (MSBU) utilizes measurements that are currently available from the operational Brewer instruments. Umkehr measurements at multiple wavelength channels (similar to the satellite BUV method) and significantly reduced range of solar zenith angle are used for the twice a day operational ozone profile retrievals. Intercomparisons against ozone climatology, sounding, satellite overpasses and Dobson ozone datasets for NOASA/Goddard, Boulder, CO and MLO, HI sites are presented in this paper. The MSBU algorithm reduces noise in the intra-annual variability of the Brewer retrieved ozone as compared to the single pair ozone retrieval. Tropospheric ozone retrievals also

  16. Ozone is mutagenic in Salmonella

    SciTech Connect

    Dillon, D.; Combes, R.; McConville, M.; Zeiger, E. )

    1992-01-01

    Ozone is a highly reactive gas that has been tested for genotoxicity in a number of systems. Induced genetic damage resulting from ozone treatment may not be readily observed because of the high toxicity of the chemical and difficulties in generating and administering controlled concentrations. The mutagenicity of ozone was investigated in Salmonella typhimurium using a plate test protocol designed for reactive vapours and gases. Ozone, at two to three consecutive doses, induced weak, albeit statistically significant, mutagenic responses in tester strain TA102 with and without Aroclor-induced rat liver S9 (lowest effective mean concentration of 0.019 ppm; 35 min total exposure). However, dose-related responses were not always obtained. No mutagenicity was detected in strains TA98, TA100, or TA1535, with or without S9. In strain TA104, ozone induced a weak response only at a single dose with S9; this response was not reproducible. Mutagenicity was dependent on the ozone flow rate and total exposure time, with variations in the optimum dose-time regimen leading to toxicity or complete inactivity. The data show that ozone is a very weak bacterial mutagen and only when tested under narrowly prescribed, subtoxic dosing conditions.

  17. Total ozone trend over Cairo

    NASA Technical Reports Server (NTRS)

    Hassan, G. K. Y.

    1994-01-01

    A world wide interest in protecting ozone layer against manmade effects is now increasing. Assessment of the ozone depletion due to these activities depends on how successfully we can separate the natural variabilities from the data. The monthly mean values of total ozone over Cairo (30 05N) for the period 1968-1988, have been analyzed using the power spectral analysis technique. The technique used in this analysis does not depend on a pre-understanding of the natural fluctuations in the ozone data. The method depends on increasing the resolution of the spectral peaks in order to obtain the more accurate sinusoidal fluctuations with wavelength equal to or less than record length. Also it handles the possible sinusoidal fluctuations with wavelength equal to or less than record length. The results show that it is possible to detect some of the well known national fluctuations in the ozone record such as annual, semiannual, quasi-biennial and quasi-quadrennial oscillations. After separating the natural fluctuations from the ozone record, the trend analysis of total ozone over Cairo showed that a decrease of about -1.2% per decade has occurred since 1979.

  18. Trends in ozone profile measurements

    NASA Technical Reports Server (NTRS)

    Johnston, H.; Aikin, A.; Barnes, R.; Chandra, S.; Cunnold, D.; Deluisi, J.; Gille, J. C.; Hudson, R.; Mccormick, M. P.; Mcmaster, L.

    1989-01-01

    From an examination of the agreements and differences between different satellite instruments, it is difficult to believe that existing satellite instruments determine upper stratospheric ozone much better than 4 pct.; by extension, it probably would require at least a 4 pct. change to be reliably detected as a change. The best estimates of the vertical profiles of ozone change in the upper stratosphere between 1979 and 1986 are judged to be those given by the two SAGE satellite instruments. SAGE-2 minus SAGE-1 gives a much lower ozone reduction than that given by the archived Solar Backscatter UV data. The average SAGE profiles of ozone changes between 20 and 50 degs north and between 20 and 50 degs south are given. The SAGE-1 and SAGE-2 comparison gives an ozone reduction of about 4 pct. at 25 km over temperate latitudes. Five ground based Umkehr stations between 36 and 52 degs north, corrected for the effects of volcanic aerosols, report an ozone reduction between 1979 and 1987 at Umkehr layer 8 of 9 + or - 5 pct. The central estimate of upper stratospheric ozone reduction given by SAGE at 40 km is less than the central value estimated by the Umkehr method at layer 8.

  19. Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

    NASA Astrophysics Data System (ADS)

    Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

    2014-04-01

    There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor of troposphere ozone photolysis rate, defined as the percentage changes in surface ozone photolysis rate for 1% increase in stratospheric ozone column, shows significant seasonal variation but is always negative with absolute value larger than one. The expected stratospheric ozone recovery is found to affect the tropospheric ozone destruction rates much more than the ozone production rates. Significant decreases in surface ozone photolysis rates due to stratospheric ozone recovery are simulated. The global average tropospheric OH decreases by 1.7%, and the global average lifetime of tropospheric ozone increases by 1.5%. The perturbations to tropospheric ozone and surface ozone show large seasonal and spatial variations. General increases in surface ozone are calculated for each season, with increases by up to 0.8 ppbv in the remote areas. Increases in ozone lifetime by up to 13% are found in the troposphere. The increased lifetimes of tropospheric ozone in response to stratospheric ozone recovery enhance the intercontinental transport of ozone and global pollution, in particular for the summertime. The global background ozone attributable to Asian emissions is calculated to increase by up to 15% or 0.3 ppbv in the Northern Hemisphere in response to the projected stratospheric ozone recovery.

  20. The National Ozone Expedition, 1986

    SciTech Connect

    Solomon, S. )

    1987-01-01

    Eighteen scientists from four separate institutions came to McMurdo Station during the period from August to November, 1986, to carry out an intensive stratospheric measurement program aimed at obtaining further data on the antarctic ozone hole. The results from the composite of experiments strongly suggest that chemistry (specifically, the chemistry of anthropogenically produced halocarbon species) probably plays an important role in the development of the antarctic ozone hole. If the antarctic ozone hole is due to mankind's use of chlorofluorocarbons, then it represents the first time that the environment has been shown to be sensitive to man's activities on a global scale.

  1. Ozone and ozonated oils in skin diseases: a review.

    PubMed

    Travagli, V; Zanardi, I; Valacchi, G; Bocci, V

    2010-01-01

    Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics. PMID:20671923

  2. Ozone and Ozonated Oils in Skin Diseases: A Review

    PubMed Central

    Travagli, V.; Zanardi, I.; Valacchi, G.; Bocci, V.

    2010-01-01

    Although orthodox medicine has provided a variety of topical anti-infective agents, some of them have become scarcely effective owing to antibiotic- and chemotherapeutic-resistant pathogens. For more than a century, ozone has been known to be an excellent disinfectant that nevertheless had to be used with caution for its oxidizing properties. Only during the last decade it has been learned how to tame its great reactivity by precisely dosing its concentration and permanently incorporating the gas into triglycerides where gaseous ozone chemically reacts with unsaturated substrates leading to therapeutically active ozonated derivatives. Today the stability and efficacy of the ozonated oils have been already demonstrated, but owing to a plethora of commercial products, the present paper aims to analyze these derivatives suggesting the strategy to obtain products with the best characteristics. PMID:20671923

  3. Dobson spectrophotometer ozone measurements during international ozone rocketsonde intercomparison

    NASA Technical Reports Server (NTRS)

    Parsons, C. L.

    1980-01-01

    Measurements of the total ozone content of the atmosphere, made with seven ground based instruments at a site near Wallops Island, Virginia, are discussed in terms for serving as control values with which the rocketborne sensor data products can be compared. These products are profiles of O3 concentration with altitude. By integrating over the range of altitudes from the surface to the rocket apogee and by appropriately estimating the residual ozone amount from apogee to the top of the atmosphere, a total ozone amount can be computed from the profiles that can be directly compared with the ground based instrumentation results. Dobson spectrophotometers were used for two of the ground-based instruments. Preliminary data collected during the IORI from Dobson spectrophotometers 72 and 38 are presented. The agreement between the two and the variability of total ozone overburden through the experiment period are discussed.

  4. Analysis of error in TOMS total ozone as a function of orbit and attitude parameters

    NASA Technical Reports Server (NTRS)

    Gregg, W. W.; Ardanuy, P. E.; Braun, W. C.; Vallette, B. J.; Bhartia, P. K.; Ray, S. N.

    1991-01-01

    Computer simulations of orbital scenarios were performed to examine the effects of orbital altitude, equator crossing time, attitude uncertainty, and orbital eccentricity on ozone observations by future satellites. These effects were assessed by determining changes in solar and viewing geometry and earth daytime coverage loss. The importance of these changes on ozone retrieval was determined by simulating uncertainties in the TOMS ozone retrieval algorithm. The major findings are as follows: (1) Drift of equator crossing time from local noon would have the largest effect on the quality of ozone derived from TOMS. The most significant effect of this drift is the loss of earth daytime coverage in the winter hemisphere. The loss in coverage increases from 1 degree latitude for + or - 1 hour from noon, 6 degrees for + or - 3 hours from noon, to 53 degrees for + or - 6 hours from noon. An additional effect is the increase in ozone retrieval errors due to high solar zenith angles. (2) To maintain contiguous earth coverage, the maximum scan angle of the sensor must be increased with decreasing orbital altitude. The maximum scan angle required for full coverage at the equator varies from 60 degrees at 600 km altitude to 45 degrees at 1200 km. This produces an increase in spacecraft zenith angle, theta, which decreases the ozone retrieval accuracy. The range in theta was approximately 72 degrees for 600 km to approximately 57 degrees at 1200 km. (3) The effect of elliptical orbits is to create gaps in coverage along the subsatellite track. An elliptical orbit with a 200 km perigee and 1200 km apogee produced a maximum earth coverage gap of about 45 km at the perigee at nadir. (4) An attitude uncertainty of 0.1 degree in each axis (pitch, roll, yaw) produced a maximum scan angle to view the pole, and maximum solar zenith angle).

  5. Inhibitory effect of hydrogen sulfide on ozone-induced airway inflammation, oxidative stress, and bronchial hyperresponsiveness.

    PubMed

    Zhang, Pengyu; Li, Feng; Wiegman, Coen H; Zhang, Min; Hong, Yan; Gong, Jicheng; Chang, Yan; Zhang, Junfeng Jim; Adcock, Ian; Chung, Kian Fan; Zhou, Xin

    2015-01-01

    Exposure to ozone has been associated with airway inflammation, oxidative stress, and bronchial hyperresponsiveness. The goal of this study was to examine whether these adverse effects of ozone could be prevented or reversed by hydrogen sulfide (H2S) as a reducing agent. The H2S donor sodium (NaHS) (2 mg/kg) or vehicle (PBS) was intraperitoneally injected into mice 1 hour before and after 3-hour ozone (2.5 ppm) or air exposure, and the mice were studied 24 hours later. Preventive and therapeutic treatment with NaHS reduced the ozone-induced increases in the total cells, including neutrophils and macrophages; this treatment also reduced levels of cytokines, including TNF-α, chemokine (C-X-C motif) ligand 1, IL-6, and IL-1β levels in bronchial alveolar lavage fluid; inhibited bronchial hyperresponsiveness; and attenuated ozone-induced increases in total malondialdehyde in bronchoalveolar lavage fluid and decreases in the ratio of reduced glutathione/oxidized glutathione in the lung. Ozone exposure led to decreases in the H2S production rate and in mRNA and protein levels of cystathionine-β-synthetase and cystathionine-γ-lyase in the lung. These effects were prevented and reversed by NaHS treatment. Furthermore, NaHS prevented and reversed the phosphorylation of p38 mitogen-activated protein kinase and heat shock protein 27. H2S may have preventive and therapeutic value in the treatment of airway diseases that have an oxidative stress basis. PMID:25010831

  6. 76 FR 5078 - Approval and Promulgation of Air Quality Implementation Plans: Tennessee; Approval of Section 110...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-28

    ... rulemaking to approve Tennessee's August 3, 2010, SIP revision under parallel processing. 75 FR 62354... nonattainment for the 1-hour ozone NAAQS on November 6, 1991, 56 FR 56694 (effective January 6, 1992, 60 FR 7124... to attainment for the 1-hour ozone NAAQS (61 FR 55903). The maintenance plan for the Area...

  7. Sensitivity Studies for Assimilated Ozone Profiles

    NASA Technical Reports Server (NTRS)

    Stajner, Ivanka; Winslow, Nathan; Wargan, Krzysztof; Rood, Richard; Pawson, Steven

    2002-01-01

    An ozone data assimilation system at the NASA/Goddard Data Assimilation Office (DAO) produces three-dimensional global ozone fields. They are obtained by assimilating ozone retrieved from the Solar Backscatter UltraViolet/2 (SBUV/2) instrument and the Earth Probe Total Ozone Mapping Spectrometer (EP TOMS) measurements into an off-line parameterized chemistry and transport model. In this talk we focus on the quality of lower stratospheric assimilated ozone profiles. Ozone in the lower stratosphere plays a key role in the forcing of climate. A biased ozone field in this region will adversely impact calculations of the stratosphere-troposphere exchange and, when used as a first guess in retrievals, the values determined from satellite observations. The SBUV/2 ozone data have a coarse vertical resolution with increased uncertainty below the ozone maximum, and TOMS provides only total ozone columns. Thus, the assimilated ozone profiles in the lower stratosphere are only weakly constrained by the incoming SBUV and TOMS data. Consequently, the assimilated ozone distribution should be sensitive to changes in inputs to the statistical analysis scheme. We investigate the sensitivity of assimilated ozone profiles to changes in a variety of system inputs: TOMS and SBUV/2 data selection, forecast and observations error covariance models, inclusion or omission of a parameterized chemistry model, and different versions of DAO assimilated wind fields used to drive the transport model. Comparisons of assimilated ozone fields with independent observations, primarily ozone sondes, are used to determine the impact of each of these changes.

  8. Ozone Monitoring Instrument

    NASA Astrophysics Data System (ADS)

    de Vries, Johan

    The Ozone Monitoring Instrument is a trace gas monitoring instrument in the line of GOME (ERS-2) and Sciamachy (ENVISAT). Following these instruments, OMI provides UV-visible spectroscopy with a resolution sufficient to separate out the various absorbing trace gases (using DOAS or `Full' retrieval), but shaped as an imaging spectrometer. This means that a two dimensional detector is used where one dimension records the spectrum and the other images the swath. The scanning mechanism from the GOME and Sciamachy is not required anymore and there are considerable advantages with respect to simultaneous measurement of swath pixels, polarisation and obtainable swath width. The OMI consortium for a phase B is formed by Fokker Space & Systems and TPD in the Netherlands and VTT in Finland. In the presentation UV-visible atmospheric remote sensing will be placed in perspective and the OMI will be explaned.

  9. Overview of ozone human exposure and health risk analyses used in the U.S. EPA's review of the ozone air quality standard.

    SciTech Connect

    Whitfield, R. G.

    1999-03-04

    This paper presents an overview of the ozone human exposure and health risk analyses developed under sponsorship of the U.S. Environmental Protection Agency (EPA). These analyses are being used in the current review of the national ambient air quality standards (NAAQS) for ozone. The analyses consist of three principal steps: (1) estimating short-term ozone exposure for particular populations (exposure model); (2) estimating population response to exposures or concentrations (exposure-response or concentration-response models); and (3) integrating concentrations or exposure with concentration-response or exposure-response models to produce overall risk estimates (risk model). The exposure model, called the probabilistic NAAQS exposure model for ozone (pNEM/03), incorporates the following factors: hourly ambient ozone concentrations; spatial distribution of concentrations; ventilation state of individuals at time of exposure; and movement of people through various microenvironments (e.g., outdoors, indoors, inside a vehicle) of varying air quality. Exposure estimates are represented by probability distributions. Exposure-response relationships have been developed for several respiratory symptom and lung function health effects, based on the results of controlled human exposure studies. These relationships also are probabilistic and reflect uncertainties associated with sample size and variability of response among subjects. The analyses also provide estimates of excess hospital admissions in the New York City area based on results from an epidemiology study. Overall risk results for selected health endpoints and recently analyzed air quality scenarios associated with alternative 8-hour NAAQS and the current 1-hour standard for outdoor children are used to illustrate application of the methodology.

  10. UV/Ozone treatment to decontaminate tritium contaminated surfaces

    SciTech Connect

    Krasznai, J.P.; Mowat, R.

    1995-10-01

    Tritium contamination on surfaces is often encountered during operation and maintenance of equipment at the Darlington Tritium Removal Facility and likely at other tritium handling facilities. The use of efficient decontamination techniques that produce little or no secondary wastes is desirable. At Ontario Hydro Technologies (OHT) we have been developing a process utilizing a combination of ultraviolet (UV) radiation and ozone gas to remove tritium surface contamination from materials often used in tritium service. This paper summarizes the performance of the technique. The results are encouraging because the technique is very effective, simple in terms of equipment requirements and concentrates tritium in an easily managed waste form. 7 refs., 3 figs., 2 tabs.

  11. The photolysis of ozone

    NASA Technical Reports Server (NTRS)

    Lissi, E.; Heicklen, J.

    1972-01-01

    Ozone was photolyzed at 25 C with steady illumination at several wavelengths from 2288 to 2850 A, at O3 pressures from 0.1 to 2.7 torr, and at absorbed intensities from 0.15 to 65 microns/min. Experiments were done in pure dry O3, and in the presence of He, CO2, N2, H2O, H2, N2O, He-CO2, He-H2O, CO2-H2O, O2-N2O, CO2-O2, and N2O5-O2-CO2 mixtures. The results show that in the absence of added gases or in the presence of He, the quantum yield of O3 consumption is 5.5 independent of conditions, except at pressures below 0.4 torr. In the presence of CO2 or N2, ozone consumption falls toward 4.0. The primary photolytic act produces O(1 D) and siglet O2, presumably O2(1 delta), at all wavelengths below 3000 A. Relative quenching constants O(1 D) removal by various gases were measured at 2288, 2537, and 2800 A. For O3, CO2, and N2, the relative rates are 1.0/0.4 to 0.5/0.08 to 0.11 at all wavelengths. For H2O the constant at 2537 A is 1.5 relative to that for O3. With N2O, a noticeable wavelength effect is observed and the relative rate constants are 1.5, 2 to 3, 4.0 for O3 compared to N2O at 2800, 2537, and 2288 A, respectively.

  12. Maintenance strategies for greater availability

    SciTech Connect

    Pradhan, S. )

    1994-01-01

    Benchmark studies have confirmed there is a very wide gap in perceived world-class versus actual maintenance performance. To bridge this gap, companies will have to quickly adopt appropriate preventive and predictive maintenance practices and implement total productive maintenance (TPM) and reliability centered maintenance (RCM) practices. In process plants the whole approach to maintenance is slipshod, with a jumble of acronyms like PM/RM/CPM/flexing/multi-skilling, etc., giving a false sense of progress. North American maintenance benchmarks and British maintenance best practice give a very clear picture of current maintenance practices. Both of these studies indicate that breakdown maintenance is the dominant mode of maintenance in the progress industries. There are several key steps to be followed in establishing a strategy for maintenance improvements: (1) Recognize maintenance as an executive function; (2) Establish a solid maintenance performance database; (3) Review the existing plant maintenance practices; (4) Review and understand world-class maintenance practices; and (5) Design a master plan for a world-class system: Define the plant and maintenance resources; Define multi-skilling strategy; Define training and education levels for each job grouping; and Apply, and don't just talk about TPM and RCM.

  13. Ozonation of cooling tower waters

    NASA Technical Reports Server (NTRS)

    Humphrey, M. F.; French, K. R.; Howe, R. D. (Inventor)

    1979-01-01

    Continuous ozone injection into water circulating between a cooling tower and heat exchanger with heavy scale deposits inhibits formation of further deposits, promotes flaking of existing deposits, inhibits chemical corrosion and controls algae and bacteria.

  14. Air Quality Guide for Ozone

    MedlinePlus

    ... is one of our nation’s most common air pollutants. Use the chart below to help reduce your ... human health. Ozone forms when two types of pollutants (VOCs and NOx) react in sunlight. These pollutants ...

  15. A search For Artic ozone

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    Four atmospheric scientists took off with their instruments for Greenland last week, where they will try to see if depletion of stratospheric ozone in the Arctic can be detected as it has been in Antarctica since 1985.Members of the scientific team include Susan Solomon and George Mount of the Aeronomy Laboratory at the National Atmospheric and Oceanic Administration (NOAA) in Boulder, Colo., and Ryan Sanders and Roger Jakoubec of the Cooperative Institute for Research in Environmental Science in Norman, Okla. These four participated in previous National Ozone Expedition (NOZE) investigations at McMurdo Station in Antarctica that helped document the ozone “hole,” decreases of up to 50% in ozone during the early austral spring in September and October of the last 2 years (1986-1987).

  16. Ozone - Current Air Quality Index

    MedlinePlus

    ... reducing exposure to extremely high levels of particle pollution is available here . Fires: Current Conditions Click to ... Air Quality Basics Air Quality Index | Ozone | Particle Pollution | Smoke from fires | What You Can Do Health ...

  17. Monsoon circulation and atmospheric ozone

    NASA Astrophysics Data System (ADS)

    Khrgian, A. Kh.; Nguyen, Van Thang

    1991-01-01

    The effect of the Indonesian-Australian winter monsoon, proceeding from the Asian continent to the south, on the atmospheric ozone is examined. It is shown that large-scale atmospheric circulation phenomena caused by monsoons in the tropical regions of Australia and in south-eastern Asia can cause significant falls in atmospheric ozone concentrations. The common occurrence of such phenomena might explain the higher-than-average incidence of skin cancer in Australia.

  18. Method of sterilization using ozone

    NASA Technical Reports Server (NTRS)

    Murphy, Oliver J. (Inventor); Hitchens, G. Duncan (Inventor)

    2002-01-01

    Methods of using ozone have been developed which sterilize instruments and medical wastes, oxidize, organics found in wastewater, clean laundry, break down contaminants in soil into a form more readily digested by microbes, kill microorganisms present in food products, and destroy toxins present in food products. The preferred methods for killing microorganism and destroying toxins use pressurized, humidified, and concentrated ozone produced by an electrochemical cell.

  19. Reliability Centered Maintenance - Methodologies

    NASA Technical Reports Server (NTRS)

    Kammerer, Catherine C.

    2009-01-01

    Journal article about Reliability Centered Maintenance (RCM) methodologies used by United Space Alliance, LLC (USA) in support of the Space Shuttle Program at Kennedy Space Center. The USA Reliability Centered Maintenance program differs from traditional RCM programs because various methodologies are utilized to take advantage of their respective strengths for each application. Based on operational experience, USA has customized the traditional RCM methodology into a streamlined lean logic path and has implemented the use of statistical tools to drive the process. USA RCM has integrated many of the L6S tools into both RCM methodologies. The tools utilized in the Measure, Analyze, and Improve phases of a Lean Six Sigma project lend themselves to application in the RCM process. All USA RCM methodologies meet the requirements defined in SAE JA 1011, Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes. The proposed article explores these methodologies.

  20. Antimicrobials in periodontal maintenance.

    PubMed

    Jorgensen, M G; Slots, J

    2001-01-01

    Mechanical and chemical antimicrobial intervention is the mainstay of preventive periodontal therapy. Successful periodontal maintenance care depends upon the ability of oral health care professionals to combat periodontal infections, and patient compliance with prescribed follow-up care. Since tooth brushing, flossing, and oral rinsing do not reach pathogens present in furcations and at the depths of deep periodontal pockets, adequate oral hygiene should include subgingival treatment with home irrigators or other appropriate self-care remedies in patients with these conditions. Povidone-iodine for professional use and diluted bleach for self-care are inexpensive and valuable antimicrobial agents in periodontal maintenance. The present article outlines the prudent use of antimicrobial therapy in periodontal maintenance. PMID:11603305

  1. Using ozone to treat cooling tower water

    SciTech Connect

    Webster, L.

    1995-07-01

    Ozone is a controversial but promising alternative to chemicals for treating water in cooling towers. A powerful disinfectant, ozone can prevent biofouling of heat exchange surfaces, and may mitigate scale and corrosion. Ozone treatment of cooling towers can cut costs for energy, water, sewage, and regulatory compliance. Ozone treatment is an electrotechnology, but ozone equipment represents only a small electric load. Although ozone has provided excellent results in some cooling tower applications, its effectiveness has not been proven conclusively. Less than 1,000 cooling towers use ozone water treatment in the United States. Acceptance of this technology is increasing, however, as indicated by its use by such large firms as IBM, AT and T, DuPont, and Xerox, and by its adoption by some chemical water treatment suppliers. The energy efficiency implications of ozone treatment are being researched. Southern California Edison found that in some systems, ozone treatment improved chiller efficiency up to 20 percent due to cleaner heat exchange surfaces.

  2. Corona Discharge Influences Ozone Concentrations Near Rats

    SciTech Connect

    Goheen, Steven C.; Gaither, Kari A.; Anantatmula, Shantha M.; Mong, Gary M.; Sasser, Lyle B.; Lessor, Delbert L.

    2004-02-26

    Ozone is produced by corona discharge in air. Its production is enhanced near grounded water. Whether grounded animals behave like grounded water, producing more ozone was investigated. Rats were exposed to corona discharge in a plastic cage. The concentration of ozone in the gas phase was monitored. The ozone concentration exceeded ambient levels only in the presence of corona discharge and either rats or water. When water or rats were exposed to corona discharge, ozone levels were more than 10 times higher than controls. Ozone levels increased rapidly with applied voltage. There was also a correlation between the distance of the corona needle to the rats and the amount of ozone produced. As the distance increased, ozone production decreased. These results are discussed in relation to the potential exposure of mammals to ozone in the vicinity of corona discharge and electric fields.

  3. Ground-level ozone in Alberta

    SciTech Connect

    Sandhu, H.S.

    1999-11-01

    This literature review on ground-level ozone in Alberta begins with introductory sections on the precursors and products of ozone formation, the chemistry and meteorology of ozone, and atmospheric ozone models. The subsequent section reviews ozone data from ambient air quality monitoring stations in Alberta. The final section discusses trends in ozone concentrations in urban and rural areas of Alberta, human and environmental health effects of ozone, proposed national ambient objectives and Canada-wide standards for ground-level ozone, and options for an ozone concentration standard for Alberta. Appendices include an outline of air pollutant monitoring methods used in Alberta, lists of monitoring stations, and tables of monitoring results for nitrogen oxides, total hydrocarbons, and volatile organic compounds at Calgary and Edmonton sites.

  4. Ground-level ozone in Alberta

    SciTech Connect

    Sandhu, H.S.

    1999-01-01

    This literature review on ground-level ozone in Alberta begins with introductory sections on the precursors and products of ozone formation, the chemistry and meteorology of ozone, and atmospheric ozone models. The subsequent section reviews ozone data from ambient air quality monitoring stations in Alberta. The final section discusses trends in ozone concentrations in urban and rural areas of Alberta, human and environmental health effects of ozone, proposed national ambient objectives and Canada-wide standards for ground-level ozone, and options for an ozone concentration standard for Alberta. Appendices include an outline of air pollutant monitoring methods used in Alberta, lists of monitoring stations, and tables of monitoring results for nitrogen oxides, total hydrocarbons, and volatile organic compounds at Calgary and Edmonton sites.

  5. The 2002 Antarctic Ozone Hole

    NASA Technical Reports Server (NTRS)

    Newman, P. A.; Nash, E. R.; Douglass, A. R.; Kawa, S. R.

    2003-01-01

    Since 1979, the ozone hole has grown from near zero size to over 24 Million km2. This area is most strongly controlled by levels of inorganic chlorine and bromine oncentrations. In addition, dynamical variations modulate the size of the ozone hole by either cooling or warming the polar vortex collar region. We will review the size observations, the size trends, and the interannual variability of the size. Using a simple trajectory model, we will demonstrate the sensitivity of the ozone hole to dynamical forcing, and we will use these observations to discuss the size of the ozone hole during the 2002 Austral spring. We will further show how the Cly decreases in the stratosphere will cause the ozone hole to decrease by 1-1.5% per year. We will also show results from a 3-D chemical transport model (CTM) that has been continuously run since 1999. These CTM results directly show how strong dynamics acts to reduce the size of the ozone hole.

  6. Wave-Like Ozone Movements

    NASA Astrophysics Data System (ADS)

    Roldugin, V. C.; Nikulin, G. N.; Henriksen, K.

    The wave-like character of the total ozone variations is examined from the Aral Sea and Karaganda observatories in Middle Asia, and from Tromsø and Murmansk in the Arctic. The waves have a period of 10-20 days and an amplitude of about 20-50 DU. They are seen practically every year when the ozone data do not contain too many gaps. In Middle Asia waves with the same periods are found in geopotential height and tropopause pressure variations. The ozone waves are caused by dynamic meteorological disturbances near the tropopause. The passing of a wave crest in the pressure field causes the convergence of ozone poor air under the tropopause and the divergence of ozone rich air above the tropopause giving rise to a total ozone content decrease. The passing of a wave trough stimulates the opposite process. By crosscorrelation analysis the wave-like movement was determined as eastward for both pairs of stations with a velocity of 11-15 °/day.

  7. Ozone Conference II: Abstract Proceedings

    SciTech Connect

    1999-11-01

    Ozone Conference II: Pre- and Post-Harvest Applications Two Years After Gras, was held September 27-28, 1999 in Tulare, California. This conference, sponsored by EPRI's Agricultural Technology Alliance and Southern California Edison's AgTAC facility, was coordinated and organized by the on-site ATA-AgTAC Regional Center. Approximately 175 people attended the day-and-a-half conference at AgTAC. During the Conference twenty-two presentations were given on ozone food processing and agricultural applications. Included in the presentations were topics on: (1) Ozone fumigation; (2) Ozone generation techniques; (3) System and design applications; (4) Prewater treatment requirements; (5) Poultry water reuse; (6) Soil treatments with ozone gas; and (7) Post-harvest aqueous and gaseous ozone research results. A live videoconference between Tulare and Washington, D.C. was held to discuss the regulators' view from inside the beltway. Attendees participated in two Roundtable Question and Answer sessions and visited fifteen exhibits and demonstrations. The attendees included university and governmental researchers, regulators, consultants and industry experts, technology developers and providers, and corporate and individual end-users. This report is comprised of the Abstracts of each presentation, biographical sketches for each speaker and a registration/attendees list.

  8. The use of ozone to extend the shelf-life and maintain quality of fresh produce.

    PubMed

    Glowacz, Marcin; Colgan, Richard; Rees, Deborah

    2015-03-15

    Fresh produce has been recognised as a healthy food, thus there is increasing consumer demand for fresh fruit and vegetables. The shelf-life of fresh produce, however, is relatively short and is limited by microbial contamination or visual, textural and nutritional quality loss. There are many methods to reduce/eliminate microorganisms present in food and ozone treatment is one of them. The use of ozone by the fresh produce industry is a good alternative to chemical treatments, e.g. the use of chlorine. The effectiveness of ozone as an antimicrobial agent has previously been reviewed and has been updated here, with the latest findings. The main focus of this review is on the effects of ozone on the fresh produce quality, defined by maintenance of texture, visual quality, taste and aroma, and nutritional content. Furthermore, ozone has been found to be efficient in reducing pesticide residues from the produce. The treatments that have the ability to reduce microbial contamination of the product without having an adverse effect on its visual, textural and nutritional quality can be recommended and subsequently incorporated into the supply chain. A good understanding of all the benefits and limitations related to the use of ozone is needed, and relevant information has been reviewed in this paper. PMID:24913013

  9. Maintenance simulation: Software issues

    SciTech Connect

    Luk, C.H.; Jette, M.A.

    1995-07-01

    The maintenance of a distributed software system in a production environment involves: (1) maintaining software integrity, (2) maintaining and database integrity, (3) adding new features, and (4) adding new systems. These issues will be discussed in general: what they are and how they are handled. This paper will present our experience with a distributed resource management system that accounts for resources consumed, in real-time, on a network of heterogenous computers. The simulated environments to maintain this system will be presented relate to the four maintenance areas.

  10. New dynamic NNORSY ozone profile climatology

    NASA Astrophysics Data System (ADS)

    Kaifel, A. K.; Felder, M.; Declercq, C.; Lambert, J.-C.

    2012-01-01

    Climatological ozone profile data are widely used as a-priori information for total ozone using DOAS type retrievals as well as for ozone profile retrieval using optimal estimation, for data assimilation or evaluation of 3-D chemistry-transport models and a lot of other applications in atmospheric sciences and remote sensing. For most applications it is important that the climatology represents not only long term mean values but also the links between ozone and dynamic input parameters. These dynamic input parameters should be easily accessible from auxiliary datasets or easily measureable, and obviously should have a high correlation with ozone. For ozone profile these parameters are mainly total ozone column and temperature profile data. This was the outcome of a user consultation carried out in the framework of developing a new, dynamic ozone profile climatology. The new ozone profile climatology is based on the Neural Network Ozone Retrieval System (NNORSY) widely used for ozone profile retrieval from UV and IR satellite sounder data. NNORSY allows implicit modelling of any non-linear correspondence between input parameters (predictors) and ozone profile target vector. This paper presents the approach, setup and validation of a new family of ozone profile climatologies with static as well as dynamic input parameters (total ozone and temperature profile). The neural network training relies on ozone profile measurement data of well known quality provided by ground based (ozonesondes) and satellite based (SAGE II, HALOE, and POAM-III) measurements over the years 1995-2007. In total, four different combinations (modes) for input parameters (date, geolocation, total ozone column and temperature profile) are available. The geophysical validation spans from pole to pole using independent ozonesonde, lidar and satellite data (ACE-FTS, AURA-MLS) for individual and time series comparisons as well as for analysing the vertical and meridian structure of different modes of

  11. Seasonal variability of surface ozone in Korea

    NASA Astrophysics Data System (ADS)

    Wie, J.; Moon, B. K.; Choi, H.

    2015-12-01

    Tropospheric ozone around East Asia include Korea impacts on air quality and climate, and has been increased with rapid economic growth. To better understanding, we analyzed seasonal variability of tropospheric ozone simulated by using GEOS-Chem. Surface ozone concentration in Korea has double peaks in April and September. Tropospheric ozone increases primarily associated with westerly wind anomaly in spring, with warming in summer and autumn, and with cloud depletion in winter. Surface ozone in spring elevated after mature-phase El Niño winters. Key words: surface ozone, seasonal variability, Korea, East Asia Acknowledgements This work was supported by Korea Ministry of Environment as "Climate Change Correspondence Program."

  12. Scientific assessment of ozone depletion: 1991

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Over the past few years, there have been highly significant advances in the understanding of the impact of human activities on the Earth's stratospheric ozone layer and the influence of changes in chemical composition of the radiative balance of the climate system. Specifically, since the last international scientific review (1989), there have been five major advances: (1) global ozone decreases; (2) polar ozone; (3) ozone and industrial halocarbons; (4) ozone and climate relations; and (5) ozone depletion potentials (ODP's) and global warming potentials (GWP's). These topics and others are discussed.

  13. The 1991 Antarctic ozone hole - TOMS observations

    NASA Technical Reports Server (NTRS)

    Krueger, Arlin; Schoeberl, Mark; Newman, Paul; Stolarski, Richard

    1992-01-01

    The 1991 Antarctic springtime ozone decline, as measured by the Total Ozone Mapping Spectrometer (TOMS), was similar to those of earlier deep ozone hole years, 1987, 1989, and 1990. The minimum total ozone value was recorded on October 5, 1991 at 108 Dobson units near the South Pole. This was 8 DU lower than in any of the earlier years. Four of the last five years have exhibited an extensive, deep ozone hole. The area of the hole was about the same as in 1987, 1989, and 1990. The recovery of the low total ozone values occurred in mid-November as the polar vortex broke up.

  14. Tropospheric Ozone Over North America

    NASA Astrophysics Data System (ADS)

    Oltmans, S. J.; Thompson, A. M.; Cooper, O. R.; Merrill, J. T.; Tarasick, D. W.; Newchurch, M. J.

    2007-05-01

    Ozone in the troposphere plays a significant role as an absorber of infrared radiation (greenhouse gas), in the cleansing capacity of the atmosphere as a precursor of hydroxol radical formation, and a regulated air pollutant capable of deleterious health and ecosystem effects. Knowledge of the ozone budget in the troposphere over North America (NA) is required to properly understand the various mechanisms that contribute to the measured distribution and to develop and test models capable of simulating and predicting this key player in atmospheric chemical and physical processes. Recent field campaigns including the 2004 and 2006 INTEX Ozone Network Studies (IONS) http:croc.gsfc.nasa.gov/intexb/ions06.html that have included intensive ozone profile measurements from ozonesondes provide a unique data set for describing tropospheric ozone over a significant portion of the North American continent. These campaigns have focused on the spring and summer seasons when tropospheric ozone over NA is particularly influenced by long-range transport processes, significant photochemical ozone production resulting from both anthropogenic and natural (lightning) precursor emissions, and exchange with the stratosphere. This study uses ozone profiles measured over NA in the latitude band from approximately 12-60N, extending from the tropics to the high mid latitudes, to describe the seasonal behavior of tropospheric ozone over NA with an emphasis on the spring and summer. This includes the variability within seasons at a particular site as well as the contrasts between the seasons. Emphasis is placed on the variations among the sites including latitudinal and longitudinal gradients and how these differ through the seasons and with altitude in the troposphere. Regional differences are most pronounced during the summer season likely reflecting the influence of a wider variation in processes influencing the tropospheric ozone distribution including lightning NOX production in the upper

  15. Historical trends and ozone forecasting for urban regions of South Texas using statistical and heuristic techniques

    NASA Astrophysics Data System (ADS)

    Brown, Ronald K.

    . Ideally, the models should be developed using an optimum quantity of data and input parameters. Findings from this study indicate that only two years of data would be sufficient to develop a model instead of using large quantities of data. The analyses of trends in observed data is important to understand the ozone formation and identify the periods of high ozone concentrations in a region. Statistical Regression Analysis and Artificial Neural Networks models were developed to forecast high ozone episodes of Corpus Christi, San Antonio and Victoria. The predictive capabilities of these models were compared to determine their accuracy in forecasting daily maximum eight-hour ozone and peak one-hour ozone concentration by different model evaluation statistics. Results of the study indicated that both models were able to capture trends in ozone time series, but they were unable to accurately forecast peak ozone values. Between the two models, the performance of the Statistical Analysis model LR - RMSE averages ranged from 13.55 to 15.96 and the Artificial Neural Networks model MLP - RMSE averages ranged from 12.56 to 14.96, there seems to be very little difference in the forecasting capabilities. Also, it should be noted that according to forecasting skill proficiency, the 8-hour ozone standard provided the highest probability of detection of a high ozone forecast than did the 1-hour standard. There is still a degree of uncertainty associated with the result of the findings concerning the models ability to make accurate forecast. Previous studies have also noted that the difference in the performance superiority of one modeling technique over the other is suspect. Where the skill proficiency of one model fails the other may succeed and vice versa.

  16. Home Maintenance Manual.

    ERIC Educational Resources Information Center

    Richmond, Jim; And Others

    This manual, written especially for the Navajo and Hopi Indian Relocation Commission, is a simply worded, step-by-step guide to home maintenance for new homeowners. It can be used for self-study or it can serve as instructional material for a training class on home ownership. The manual is organized in nine sections that cover the following…

  17. CH Packaging Maintenance Manual

    SciTech Connect

    Washington TRU Solutions

    2002-01-02

    This procedure provides instructions for performing inner containment vessel (ICV) and outer containment vessel (OCV) maintenance and periodic leakage rate testing on the following packaging seals and corresponding seal surfaces using a nondestructive helium (He) leak test. In addition, this procedure provides instructions for performing ICV and OCV structural pressure tests.

  18. Floors: Care and Maintenance.

    ERIC Educational Resources Information Center

    Post Office Dept., Washington, DC.

    Guidelines, methods and policies regarding the care and maintenance of post office building floors are overviewed in this handbook. Procedures outlined are concerned with maintaining a required level of appearance without wasting manpower. Flooring types and characteristics and the particular cleaning requirements of each type are given along with…

  19. Diesel Vehicle Maintenance Competencies.

    ERIC Educational Resources Information Center

    Braswell, Robert; And Others

    Designed to provide a model set of competencies, this manual presents tasks which were identified by employers, employees, and teachers as important in a postsecondary diesel vehicle maintenance curriculum. The tasks are divided into seven major component areas of instruction: chassis and suspension, diesel engines, diesel fuel, electrical,…

  20. Operations and maintenance philosophy

    SciTech Connect

    DUNCAN, G.P.

    1999-10-28

    This Operations and Maintenance (O&M) Philosophy document is intended to establish a future O&M vision, with an increased focus on minimizing worker exposure, ensuring uninterrupted retrieval operations, and minimizing operation life-cycle cost. It is intended that this document would incorporate O&M lessons learned into on-going and future project upgrades.

  1. Maintenance Crisis vs Solutions.

    ERIC Educational Resources Information Center

    Haggard, Susie

    Industrial maintenance in Northeast Georgia is facing an acute crisis. Contributing factors are economic development that is depleting the work force, aging of the population, downsizing of the military, and lack of technical school graduates. Solutions to the crisis fall into three categories: short-term, mid-term, and long-term. For short-term…

  2. Floors: Selection and Maintenance.

    ERIC Educational Resources Information Center

    Berkeley, Bernard

    Flooring for institutional, commercial, and industrial use is described with regard to its selection, care, and maintenance. The following flooring and subflooring material categories are discussed--(1) resilient floor coverings, (2) carpeting, (3) masonry floors, (4) wood floors, and (5) "formed-in-place floors". The properties, problems,…

  3. Industrial Mechanical Maintenance.

    ERIC Educational Resources Information Center

    Hendrix, Laborn J.

    This manual was developed to assist teachers in Oklahoma in preparing students for industrial mechanical maintenance. The materials in this teacher's guide are organized in 14 units of instruction covering the following four areas: receiving and setting equipment; equipment hookup and operation; equipment layout, anchoring, and setup; and…

  4. Electrical Maintenance Technician.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This document contains 30 units to consider for use in a tech prep competency profile for the occupation of electrical maintenance technician. All the units listed will not necessarily apply to every situation or tech prep consortium, nor will all the competencies within each unit be appropriate. Several units appear within each specific…

  5. Care and Maintenance.

    ERIC Educational Resources Information Center

    Hampton, Carol D.; Hampton, Carolyn H.

    1980-01-01

    Described is a method for bringing the sea into the classroom by setting up a saltwater aquarium. Included is selection of an aquarium, filtering systems, water (whether natural salt or synthetic sea salts), bottom materials, setting up an aquarium, system stabilization, stocking an aquarium, and maintenance of the aquarium. (DS)

  6. Computerized Fleet Maintenance.

    ERIC Educational Resources Information Center

    Cataldo, John J.

    The computerization of school bus maintenance records by the Niskayuna (New York) Central School District enabled the district's transportation department to engage in management practices resulting in significant savings. The district obtains computer analyses of the work performed on all vehicles, including time spent, parts, labor, costs,…

  7. Summer Roof Maintenance.

    ERIC Educational Resources Information Center

    Liscum, Curtis L.

    1999-01-01

    Presents the items to review in roofing maintenance to prepare for the impact of summer, including checking drainage, roof-field surface and membrane, flashings, sheet metal, and rooftop equipment, such as skylights and penthouses. A list of roofing facts facility managers should know are highlighted. (GR)

  8. School Maintenance Needs

    ERIC Educational Resources Information Center

    Erickson, Paul W.

    2011-01-01

    The United States is full of schools built in the 1950s and 60s that supported the boomer school-age enrollment increase. These schools, once beacons of the neighborhood, are 50 to 60 years old and susceptible to becoming the community "eyesore." Budgeting for maintenance was fairly systematic for school districts for the first 10 to 20 years…

  9. Global tropospheric ozone investigations

    NASA Technical Reports Server (NTRS)

    Browell, Edward V.

    1998-01-01

    Ozone (O3) is one of the most important trace gases in the troposphere, and it is responsible for influencing many critical chemical and radiative processes. Ozone contributes to the formation of the hydroxyl radical (OH), which is central to most chemical reactions in the lower atmosphere, and it absorbs UV, visible, and infrared radiation which affects the energy budget and atmospheric temperatures. In addition, O3 can be used as a tracer of atmospheric pollution and stratosphere troposphere exchange. At elevated concentrations, O3 can also produce detrimental biological and human health effects. The US National Research Council (NRC) Board on Sustainable Development reviewed the US Global Change Research Program (USGCRP) [NRC, 1995], and it identified tropospheric chemistry as one of the high priority areas for the USGCRP in the next decade. The NRC identified the following specific challenges in tropospheric chemistry. Although we understand the reason for the high levels of 03 over several regions of the world, we need to better establish the distribution of O3 in the troposphere in order to document and understand the changes in the abundance of global tropospheric O3. This information is needed to quantify the contribution of O3 to the Earth' s radiative balance and to understand potential impacts on the health of the biosphere. Having recognized the importance of particles in the chemistry of the stratosphere, we must determine how aerosols and clouds affect the chemical processes in the troposphere. This understanding is essential to predict the chemical composition of the atmosphere and to assess the resulting forcing effects in the climate system. We must determine if the self-cleansing chemistry of the atmosphere is changing as a result of human activities. This information is required to predict the rate at which pollutants are removed from the atmosphere. Over nearly two decades, airborne Differential Absorption Lidar (DIAL) systems have been used in

  10. Issues in Stratospheric Ozone Depletion.

    NASA Astrophysics Data System (ADS)

    Lloyd, Steven Andrew

    Following the announcement of the discovery of the Antarctic ozone hole in 1985 there have arisen a multitude of questions pertaining to the nature and consequences of polar ozone depletion. This thesis addresses several of these specific questions, using both computer models of chemical kinetics and the Earth's radiation field as well as laboratory kinetic experiments. A coupled chemical kinetic-radiative numerical model was developed to assist in the analysis of in situ field measurements of several radical and neutral species in the polar and mid-latitude lower stratosphere. Modeling was used in the analysis of enhanced polar ClO, mid-latitude diurnal variation of ClO, and simultaneous measurements of OH, HO_2, H_2 O and O_3. Most importantly, such modeling was instrumental in establishing the link between the observed ClO and BrO concentrations in the Antarctic polar vortex and the observed rate of ozone depletion. The principal medical concern of stratospheric ozone depletion is that ozone loss will lead to the enhancement of ground-level UV-B radiation. Global ozone climatology (40^circS to 50^ circN latitude) was incorporated into a radiation field model to calculate the biologically accumulated dosage (BAD) of UV-B radiation, integrated over days, months, and years. The slope of the annual BAD as a function of latitude was found to correspond to epidemiological data for non-melanoma skin cancers for 30^circ -50^circN. Various ozone loss scenarios were investigated. It was found that a small ozone loss in the tropics can provide as much additional biologically effective UV-B as a much larger ozone loss at higher latitudes. Also, for ozone depletions of > 5%, the BAD of UV-B increases exponentially with decreasing ozone levels. An important key player in determining whether polar ozone depletion can propagate into the populated mid-latitudes is chlorine nitrate, ClONO_2 . As yet this molecule is only indirectly accounted for in computer models and field

  11. Distribution of total ozone and stratospheric ozone in the tropics - Implications for the distribution of tropospheric ozone

    NASA Technical Reports Server (NTRS)

    Fishman, Jack; Larsen, Jack C.

    1987-01-01

    Climatologies of total columnar ozone and integrated stratospheric ozone amounts at low latitudes (15 deg N to 15 deg S), derived from satellite observations, are presented. A significant longitudinal variability in total ozone is present, with highest values generally located between 60 deg W and 60 deg E. The integrated stratospheric component of total ozone, on the other hand, does not exhibit a longitudinal preference for high values. Therefore it is hypothesized that the climatological longitudinal distribution of total ozone reflects the variability of the abundance of tropospheric ozone at low latitudes. Furthermore, it is speculated that in situ photochemical production of ozone resulting from biomass burning may be responsible for the observed enhancement of total ozone at these longitudes.

  12. Assimilation of MLS and OMI Ozone Data

    NASA Technical Reports Server (NTRS)

    Stajner, I.; Wargan, K.; Chang, L.-P.; Hayashi, H.; Pawson, S.; Froidevaux, L.; Livesey, N.

    2005-01-01

    Ozone data from Aura Microwave Limb Sounder (MLS) and Ozone Monitoring Instrument (OMI) were assimilated into the ozone model at NASA's Global Modeling and Assimilation Office (GMAO). This assimilation produces ozone fields that are superior to those from the operational GMAO assimilation of Solar Backscatter Ultraviolet (SBUV/2) instrument data. Assimilation of Aura data improves the representation of the "ozone hole" and the agreement with independent Stratospheric Aerosol and Gas Experiment (SAGE) III and ozone sonde data. Ozone in the lower stratosphere is captured better: mean state, vertical gradients, spatial and temporal variability are all improved. Inclusion of OMI and MLS data together, or separately, in the assimilation system provides a way of checking how consistent OMI and MLS data are with each other, and with the ozone model. We found that differences between OMI total ozone column data and model forecasts decrease after MLS data are assimilated. This indicates that MLS stratospheric ozone profiles are consistent with OMI total ozone columns. The evaluation of error characteristics of OMI and MLS ozone will continue as data from newer versions of retrievals becomes available. We report on the initial step in obtaining global assimilated ozone fields that combine measurements from different Aura instruments, the ozone model at the GMAO, and their respective error characteristics. We plan to use assimilated ozone fields in estimation of tropospheric ozone. We also plan to investigate impacts of assimilated ozone fields on numerical weather prediction through their use in radiative models and in the assimilation of infrared nadir radiance data from NASA's Advanced Infrared Sounder (AIRS).

  13. A Study on Generation Ice Containing Ozone

    NASA Astrophysics Data System (ADS)

    Yoshimura, Kenji; Koyama, Shigeru; Yamamoto, Hiromi

    Ozone has the capability of sterilization and deodorization due to high oxidation power. It is also effective for the conservation of perishable foods and purification of water. However, ozone has a disadvantage, that is, conservation of ozone is difficult because it changes back into oxygen. Recently, ice containing ozone is taken attention for the purpose of its conservation. The use of ice containing ozone seems to keep food fresher when we conserve and transport perishable foods due to effects of cooling and sterilization of ice containing ozone. In the present study, we investigated the influence of temperatures of water dissolving ozone on the timewise attenuations of ozone concentration in water. We also investigated the influence of cooling temperature, ice diameter, initial temperatures of water dissolving ozone and container internal pressure of the water dissolving ozone on ozone concentration in the ice. In addition, we investigated the influence of the ice diameter on the timewise attenuations of ozone concentration in the ice. It was confirmed that the solidification experimental data can be adjusted by a correlation between ozone concentration in the ice and solidification time.

  14. Record Arctic ozone depletion could occur again

    NASA Astrophysics Data System (ADS)

    Balcerak, Ernie

    2012-02-01

    In the winter of 2010-2011, ozone levels above the Arctic declined to record lows, creating the first Arctic ozone hole, similar to the well-known Antarctic ozone hole. Scientists believe the ozone depletion was due partly to unusually cold temperatures in the stratosphere above the Arctic, as colder stratospheric temperatures make ozone-destroying chemicals such as chlorine more active. As global climate change continues, the Arctic stratosphere is expected to get colder, but levels of ozone-destroying chemicals should decline, as emissions of these chemicals were banned by the Montreal Protocol. To try to learn more about Arctic ozone dynamics and determine whether the Arctic ozone hole is likely to recur, Sinnhuber et al. looked at satellite observations of temperature, ozone, water vapor, and chemicals that affect ozone in the Arctic atmosphere. They also used a model to determine how sensitive ozone levels are to stratospheric temperatures and chemistry. They found that their model accurately reproduced measured conditions. Their model suggests that stratospheric temperatures 1°C lower than in the 2010-2011 winter would result in locally nearly complete ozone depletion in the Arctic lower stratosphere with current levels of chemicals. A 10% reduction in ozone-depleting chemicals would be offset by a 1°C decrease in stratospheric temperatures.

  15. Spatial observation of the ozone layer

    NASA Astrophysics Data System (ADS)

    Godin-Beekmann, Sophie

    2010-04-01

    This article provides an overview of the various satellite instruments, which have been used to observe stratospheric ozone and other chemical compounds playing a key role in stratospheric chemistry. It describes the various instruments that have been launched since the late 1970s for the measurement of total ozone column and ozone vertical profile, as well as the major satellite missions designed for the study of stratospheric chemistry. Since the discovery of the ozone hole in the early 1980s, spatial ozone measurements have been widely used to evaluate and quantify the spatial extension of polar ozone depletion and global ozone decreasing trends as a function of latitude and height. Validation and evaluation of satellite ozone data have been the subject of intense scientific activity, which was reported in the various ozone assessments of the state of the ozone layer published after the signature of the Montreal protocol. Major results, based on satellite observations for the study of ozone depletion at the global scale and chemical polar ozone loss, are provided. The use of satellite observations for the validation of chemistry climate models that simulate the recovery of the ozone layer and in data assimilation is also described.

  16. Observing Tropospheric Ozone From Space

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    2000-01-01

    The importance of tropospheric ozone embraces a spectrum of relevant scientific issues ranging from local environmental concerns, such as damage to the biosphere and human health, to those that impact global change questions, Such is climate warming. From an observational perspective, the challenge is to determine the tropospheric ozone global distribution. Because its lifetime is short compared with other important greenhouse gases that have been monitored over the past several decades, the distribution of tropospheric ozone cannot be inferred from a relatively small set of monitoring stations. Therefore, the best way to obtain a true global picture is from the use of space-based instrumentation where important spatial gradients over vast ocean expanses and other uninhabited areas can be properly characterized. In this paper, the development of the capability to measure tropospheric ozone from space over the past 15 years is summarized. Research in the late 1980s successfully led to the determination of the climatology of tropospheric ozone as a function of season; more recently, the methodology has improved to the extent where regional air pollution episodes can be characterized. The most recent modifications now provide quasi-global (50 N) to 50 S) maps on a daily basis. Such a data set would allow for the study of long-range (intercontinental) transport of air pollution and the quantification of how regional emissions feed into the global tropospheric ozone budget. Future measurement capabilities within this decade promise to offer the ability to provide Concurrent maps of the precursors to the in situ formation of tropospheric ozone from which the scientific community will gain unprecedented insight into the processes that control global tropospheric chemistry

  17. 78 FR 34965 - Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8-Hour Ozone...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-11

    ... From the Federal Register Online via the Government Publishing Office ENVIRONMENTAL PROTECTION AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; Ohio; Lima 1997 8... the request by Ohio to revise the Lima, Ohio 1997 8-hour ozone maintenance air quality...

  18. Application of ozonated dry ice (AligalTM Blue Ice) for packaging and transport in the food industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of ozone contained in dry ice pellets (ALIGALTM Blue Ice; ABI) was investigated for microbial reduction in air, and on food contact surfaces and meat products. Dry ice is used by meat and poultry processors for temperature reduction during processing and for temperature maintenance durin...

  19. Application of ozonated dry ice (ALIGAL TM Blue Ice) for packaging and transport in the food industry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effect of ozone contained in dry ice pellets (ALIGALTM Blue Ice) was investigated for microbial reduction in air and on glass surfaces and meat products. Dry ice is used by meat and poultry processors for temperature reduction during processing and temperature maintenance during transportation. ...

  20. Abiotic Buildup of Ozone

    NASA Astrophysics Data System (ADS)

    Domagal-Goldman, S. D.; Meadows, V. S.

    2010-10-01

    Two of the best biosignature gases for remote detection of life on extrasolar planets are oxygen (O2) and its photochemical byproduct, ozone (O3). The main reason for their prominence as biosignatures is that large abiotic fluxes of O2 and O3 are not considered sustainable on geological and astronomical timescales. We show here how buildup of O3 can occur on planets orbiting M stars, even in the absence of the large biological fluxes. This is possible because the destruction of O2 and O3 is driven by UV photochemistry. This chemistry is much slower on planets around these stars, due to the smaller incident UV flux. Because the destruction of these gases is slower, O3 can build up to detectable levels even if the O3 source is small. We will present atmospheric profiles of these gases for planets around AD Leo (an M dwarf) as well as spectra that show the implications for missions such as Darwin and the Terrestrial Planet Finder (TPF).

  1. Potential Source Regions for Elevated Ozone Events in Denmark

    NASA Astrophysics Data System (ADS)

    Mahura, Alexander; Nuterman, Roman; Petrova, Irina

    2010-05-01

    In our study, three Danish measurement sites having the longest time-series of ozone measurements (with a time resolution of 1 hour and starting in early 1990s) records were selected - Ulborg (DK31; 56.28°N, 8.43°E) and Frederiksborg (DK32; 55.97°N, 12.33°E) and Lille Valby (DK41; 55.69°N, 12.13°E) located on Jutland Peninsula and Zealand Island of Denmark, respectively. The measurements with high ozone level (threshold as 150 µg/m3) were selected accounting in total for more than 500 cases for these 3 locations. Note, that among these, 42 (for DK41) and 59 (for DK31 and DK32) cases showed very high ozone concentrations (i.e. above 180 µg/m3). For all these cases, at first, the trajectory modelling approach was applied in order to estimate atmospheric transport pathway of air mass arrival at the measurement sites and potential source regions from where the elevated ozone level can be associated. In our study the Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT) model using REANALYSIS meteorological dataset (global, 1948-present) was run to calculate a set of backward trajectories (in with duration of 5 day backward in time and arriving at altitude of 100 m) and divide into groups with respect to potential source regions and dominating atmospheric transport pathways using cluster analysis technique. Analyzing distribution of trajectories (associated with elevated ozone concentrations measured at the Danish sites) as a function of the sector and pathway for the atmospheric transport, the percentage of trajectories had varied among 3 locations and ranged between 11-18% (from the eastern sector), 6-13% (from SW), 10-22% (S), 7-22% (SE), 25-39% (NW), 7-13% (N); with some trajectories having no clear identification. Among trajectories there are those passing through inland (i.e. through the Baltic States, Russia, Poland, Germany, France, Benelux and Scandinavian countries) as well water areas (i.e. transport from the Atlantic Ocean, Baltic

  2. [Ozone decline and UV increase].

    PubMed

    Winkler, P; Trepte, S

    2004-02-01

    The following results have been obtained from long-term observations on the ozone layer and UV at the Meteorological Observatory Hohenpeigenberg:The seasonally varying decline of the ozone layer determines the maximum exposure to UV. Since ozone decline shows the highest rates in the spring months the UV exposure has most strongly increased in this time of the year. This is especially important because in spring the human skin is not adapted to UV exposure. Weather changes from day to day can induce rapid ozone reductions in spring about -30% which in turn is followed by an increase in UV of about 40%. Clouds, especially the transparent cirrus clouds (high clouds consisting of ice particles) have increased in frequency during spring and fall while a decrease is observed in summer. This change in cloudiness reduces the daily UV dose in spring and fall while it is enhanced in summer. With increasing height above sea level UV rises by roughly 10% per 1000 m (rule of thumb). Snow reflects the UV-radiation by up to 80% enhancing the UV-doses at relevant conditions. Strong volcano eruptions destroy ozone in the stratosphere additionally during 1-2 years after the eruption. Therafter the ozone layer recovers. In April 1993, after the eruption of Mt. Pinatubo (1991), the UV burden was still 40% higher than average. Miniholes and streamers can appear unexpected on a short-time scale and cross over Central Europe within 1-2 days, thus enhancing UV irradiation. The human skin reacts to UV exposure depending on the type of skin. The campaign "Sonne(n) mit Verstand" of the Bavarian Ministries for Environment, for Health and for Education informs about the danger of UV radiation (see www.sonne-mit-ver-stand.de). The German Weather Service informs the public on present developments of the ozone layer and relevant topics byits ozone bulletin, which is also available via internet under (www.dwd.de/deFundE/Observator/MOHp/hp2/ozon/bulletin.htm). PMID:14770335

  3. INTERACTION OF OZONE AND HERBICIDES IN SOYBEANS

    EPA Science Inventory

    The purpose of this investigation was to identify potentially damaging herbicide-ozone interactions on soybean so that injury could be reduced by judicious selection of herbicides and tolerant cultivars. The involvement of herbicide influence on stomatal aperture affecting ozone ...

  4. Polar stratospheric clouds and ozone depletion

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Turco, Richard P.

    1991-01-01

    A review is presented of investigations into the correlation between the depletion of ozone and the formation of polar stratospheric clouds (PSCs). Satellite measurements from Nimbus 7 showed that over the years the depletion from austral spring to austral spring has generally worsened. Approximately 70 percent of the ozone above Antarctica, which equals about 3 percent of the earth's ozone, is lost during September and October. Various hypotheses for ozone depletion are discussed including the theory suggesting that chlorine compounds might be responsible for the ozone hole, whereby chlorine enters the atmosphere as a component of chlorofluorocarbons produced by humans. The three types of PSCs, nitric acid trihydrate, slowly cooling water-ice, and rapidly cooling water-ice clouds act as important components of the Antarctic ozone depletion. It is indicated that destruction of the ozone will be more severe each year for the next few decades, leading to a doubling in area of the Antarctic ozone hole.

  5. Calculations of Polar Ozone Loss Rates

    NASA Technical Reports Server (NTRS)

    Dessler, A. E.; Wu, J.

    1999-01-01

    We calculate vortex-averaged ozone loss rates at 465-K potential temperature during the Aug.-Sept. time period in the southern hemisphere and Feb.-Mar. time period in the northern hemisphere. Ozone loss rates are calculated two ways. First, from the time series of measurements of 03. Second, from measurements of ClO, from which ozone loss is inferred based on our theories of Cl-catalyzed ozone destruction. Both measurement sets are from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) instrument. We find good agreement between vortex-averaged ozone loss rates calculated from these methods. Our analysis provides no support for recent work suggesting that current theories of Cl-catalyzed ozone loss underestimate the observed decrease in polar ozone during the ozone "hole" period.

  6. When Will the Antarctic Ozone Hole Recover?

    NASA Technical Reports Server (NTRS)

    Newman, Paul A.; Nash, Eric R.; Kawa, S. Randolph; Montzka, Stephen A.; Schauffler, Sue

    2006-01-01

    The Antarctic ozone hole demonstrates large-scale, man-made affects on our atmosphere. Surface observations now show that human produced ozone depleting substances (ODSs) are declining. The ozone hole should soon start to diminish because of this decline. Herein we demonstrate an ozone hole parametric model. This model is based upon: 1) a new algorithm for estimating C1 and Br levels over Antarctica and 2) late-spring Antarctic stratospheric temperatures. This parametric model explains 95% of the ozone hole area s variance. We use future ODS levels to predict ozone hole recovery. Full recovery to 1980 levels will occur in approximately 2068. The ozone hole area will very slowly decline over the next 2 decades. Detection of a statistically significant decrease of area will not occur until approximately 2024. We further show that nominal Antarctic stratospheric greenhouse gas forced temperature change should have a small impact on the ozone hole.

  7. NASA satellite helps airliners avoid ozone concentrations

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Results from a test to determine the effectiveness of satellite data for helping airlines avoid heavy concentrations of ozone are reported. Information from the Total Ozone Mapping Spectrometer, aboard the Nimbus-7 was transmitted, for use in meteorological forecast activities. The results show: (1) Total Ozone Mapping Spectrometer profile of total ozone in the atmosphere accurately represents upper air patterns and can be used to locate meteorological activity; (2) route forecasting of highly concentrated ozone is feasible; (3) five research aircraft flights were flown in jet stream regions located by the Total Ozone Mapping Spectrometer to determine winds, temperatures, and air composition. It is shown that the jet stream is coincides with the area of highest total ozone gradient, and low total ozone amounts are found where tropospheric air has been carried along above the tropopause on the anticyclonic side of the subtropical jet stream.

  8. DEVELOPMENT OF PERSONAL OZONE SAMPLERS: THREE APPROACHES

    EPA Science Inventory

    The investigators funded under the HEI ozone sampler program, Drs. Hackney, Yanagisawa, and Koutrakis, and their collaborators used different approaches to develop personal ozone samples that would be sensitive, accurate, and amenable to use in epidemiological studies.

  9. OZONE GENERATORS IN INDOOR AIR SETTINGS

    EPA Science Inventory

    The report gives information on home/office ozone generators. It discusses their current uses as amelioratives for environmental tobacco smoke, biocontaminants, volatile organic compounds, and odors and details the advantages and disadvantages of each. Ozone appears to work well ...

  10. When Will the Antarctic Ozone Hole Recover?

    NASA Technical Reports Server (NTRS)

    Newman, Paul A.

    2006-01-01

    The Antarctic ozone hole demonstrates large-scale, man-made affects on our atmosphere. Surface observations now show that human produced ozone depleting substances (ODSs) are declining. The ozone hole should soon start to diminish because of this decline. In this talk we will demonstrate an ozone hole parametric model. This model is based upon: 1) a new algorithm for estimating 61 and Br levels over Antarctica and 2) late-spring Antarctic stratospheric temperatures. This parametric model explains 95% of the ozone hole area's variance. We use future ODS levels to predict ozone hole recovery. Full recovery to 1980 levels will occur in approximately 2068. The ozone hole area will very slowly decline over the next 2 decades. Detection of a statistically significant decrease of area will not occur until approximately 2024. We further show that nominal Antarctic stratospheric greenhouse gas forced temperature change should have a small impact on the ozone hole.

  11. Ozone concentration in the cabin of a Gates Learjet measured simultaneously with atmospheric ozone concentrations

    NASA Technical Reports Server (NTRS)

    Briehl, D.; Perkins, P. J.

    1978-01-01

    A Gates Learjet Model 23 was instrumented with monitors to measure simultaneously the atmospheric and the cabin concentrations of ozone at altitudes up to 13 kilometers. Six data flights were made in February 1978. Results indicated that only a small amount of the atmospheric ozone is destroyed in the cabin pressurization system. Ozone concentrations measured in the cabin near the conditioned-air outlets were only slightly lower than the atmospheric ozone concentration. For the two cabin configurations tested, the ozone retention in the cabin was 63 and 41 percent of the atmospheric ozone concentration. Maximum cabin ozone concentration measured during these flights was 410 parts per billion by volume.

  12. Total ozone, ozone vertical distributions, and stratospheric temperatures at South Pole, Antarctica, in 1986 and 1987

    NASA Technical Reports Server (NTRS)

    Komhyr, W. D.; Grass, R. D.; Reitelbach, P. J.; Franchois, P. R.; Kuester, S. E.

    1988-01-01

    Seventy-six electrochemical cell (ECC) ozonesondes were flown at South Pole, Antarctica, during 1987 in a continuing program to document year-round changes in Antarctica ozone that are dynamically and photochemically induced. Dobson spectrophotometer total ozone observations were also made. For the twilight months of March and September when Dobson instrument observations cannot be made at South Pole, total ozone amounts were deduced from the ECC ozonesonde soundings. ECC sonde total ozone data obtained during the polar night (April to August), supplemented the sparse total ozone data obtained from Dobson instrument moon observations. Similar ozone profile and total ozone observations were made at South Pole in 1986.

  13. Associations between ozone and morbidity using the Spatial Synoptic Classification system

    PubMed Central

    2011-01-01

    Background Synoptic circulation patterns (large-scale tropospheric motion systems) affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses) on the association between ozone and hospital admissions for asthma and myocardial infarction (MI) among adults in North Carolina. Methods Daily surface meteorology data (including precipitation, wind speed, and dew point) for five selected cities in North Carolina were obtained from the U.S. EPA Air Quality System (AQS), which were in turn based on data from the National Climatic Data Center of the National Oceanic and Atmospheric Administration. We used the Spatial Synoptic Classification system to classify each day of the 9-year period from 1996 through 2004 into one of seven different air mass types: dry polar, dry moderate, dry tropical, moist polar, moist moderate, moist tropical, or transitional. Daily 24-hour maximum 1-hour ambient concentrations of ozone were obtained from the AQS. Asthma and MI hospital admissions data for the 9-year period were obtained from the North Carolina Department of Health and Human Services. Generalized linear models were used to assess the association of the hospitalizations with ozone concentrations and specific air mass types, using pollutant lags of 0 to 5 days. We examined the effect across cities on days with the same air mass type. In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions. Results Ozone was associated with asthma under dry tropical (1- to 5-day lags), transitional (3- and 4-day lags), and extreme moist tropical (0-day lag) air masses. Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses. Conclusions Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass. Certain synoptic

  14. Tropospheric Ozone from the TOMS TDOT (TOMS-Direct-Ozone-in-Troposphere) Technique During SAFARI-2000

    NASA Technical Reports Server (NTRS)

    Stone, J. B.; Thompson, A. M.; Frolov, A. D.; Hudson, R. D.; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    There are a number of published residual-type methods for deriving tropospheric ozone from TOMS (Total Ozone Mapping Spectrometer). The basic concept of these methods is that within a zone of constant stratospheric ozone, the tropospheric ozone column can be computed by subtracting stratospheric ozone from the TOMS Level 2 total ozone column, We used the modified-residual method for retrieving tropospheric ozone during SAFARI-2000 and found disagreements with in-situ ozone data over Africa in September 2000. Using the newly developed TDOT (TOMS-Direct-Ozone-in-Troposphere) method that uses TOMS radiances and a modified lookup table based on actual profiles during high ozone pollution periods, new maps were prepared and found to compare better to soundings over Lusaka, Zambia (15.5 S, 28 E), Nairobi and several African cities where MOZAIC aircraft operated in September 2000. The TDOT technique and comparisons are described in detail.

  15. Ozone exposure : Areas of potential ozone risk for selected tree species in Austria.

    PubMed

    Loibl, W; Smidt, S

    1996-12-01

    Increased tropospheric ozone concentrations cause damage to both human health and the environment. To assess the exposure of forest areas and selected tree species to ozone, it is necessary to calculate the ozone exposure distribution. The present article describes the application of an ozone interpolation model to the calculation of the ozone exposure distribution in combination with forest inventory data.The exposure of forest regions to ozone was assessed by means of an AOT40 map (accumulated ozone exposure over a threshold of 40 ppb). The calculation was performed by hourly running of the model during the summer term and accumulation of the patterns that exceeded 40 ppb.The exposure of the primary Austrian tree species to ozone can be assessed due to the spatial relation of ozone exposure and tree species patterns. This spatial relation also allows the verification of assumptions concerning ozone-related tree damage. PMID:24233419

  16. Comparison of the effects of formaldehyde and gaseous ozone on HBV-contaminated hospital quilts

    PubMed Central

    Guo, Dan; Li, Ziqiong; Jia, Bei; Che, Xiaoqiong; Song, Tianshuang; Huang, Wenxiang

    2015-01-01

    Background: Besides being highly infectious, Hepatitis B virus (HBV) is a major cause of liver disease worldwide. In hospital settings, it is easy for the environment and quilts to be contaminated by HBV patient blood and body fluids. Therefore, HBV can be transmitted to other patients via contaminated environmental surfaces or quilts, resulting in an HBV nosocomial infection. Formaldehyde and ozone are commonly used disinfectants that may influence this infectious situation. Objective: To investigate the clinical effectiveness of formaldehyde and gaseous ozone for the terminal cleaning of hospital quilts contaminated by HBV. Methods: Thin cloth and thick cotton soaked with the serum from high HBV copy number patients were prepared and disinfected using formaldehyde fumigation and gaseous ozone at different times. The copy numbers of HBV DNA in the HBV-contaminated cloth and cotton samples were measured quantitatively with fluorescent quantitative polymerase chain reaction (PCR). Results: When gaseous ozone was used to disinfect HBV-contaminated quilts for 23 minutes (min), 36 min, 49 min, and 90 min, the HBV DNA copy number displayed no significant decrease compared with the copy number before disinfection (P > 0.05). In comparison, the copy number of the HBV DNA in the cloth group decreased significantly (P < 0.05) after formaldehyde fumigation disinfection for 1 hour (h), and there was no difference when longer times and increased concentrations were used. In the thick cotton group, there was also a significant decrease (P < 0.05) of the HBV DNA copy numbers, but the decrease was not as dramatic. In addition, in this group, the disinfection effect observed at 4 h was the strongest. Conclusions: The application of ozone to disinfect HBV-contaminated hospital quilts possibly has no effect, whereas, formaldehyde oxide fumigation effectively reduced HBV copy numbers. PMID:26770591

  17. Ozone Exposure of Macrophages Induces an Alveolar Epithelial Chemokine Response through IL-1α

    PubMed Central

    Manzer, Rizwan; Dinarello, Charles A.; McConville, Glen; Mason, Robert J.

    2008-01-01

    Ozone is known to produce an acute influx of neutrophils, and alveolar epithelial cells can secrete chemokines and modulate inflammatory processes. However, direct exposure of alveolar epithelial cells and macrophages to ozone (O3) produces little chemokine response. To determine if cell–cell interactions might be responsible, we investigated the effect of alveolar macrophage–conditioned media after ozone exposure (MO3CM) on alveolar epithelial cell chemokine production. Serum-free media were conditioned by exposing a rat alveolar macrophage cell line NR8383 to ozone for 1 hour. Ozone stimulated secretion of IL-1α, IL-1β, and IL-18 from NR8383 cells, but there was no secretion of chemokines or TNF-α. Freshly isolated type II cells were cultured, so as to express the biological markers of type I cells, and these cells are referred to as type I–like cells. Type I–like cells were exposed to diluted MO3CM for 24 hours, and this conditioned medium stimulated secretion of cytokine-induced neutrophil chemattractant-1 (CXCL1) and monocyte chemoattractant protein-1 (CCL2). Secretion of these chemokines was inhibited by the IL-1 receptor antagonist. Although both recombinant IL-1α and IL-1β stimulated alveolar epithelial cells to secrete chemokines, recombinant IL-1α was 100-fold more potent than IL-1β. Furthermore, neutralizing anti-rat IL-1α antibodies inhibited the secretion of chemokines by alveolar epithelial cells, whereas neutralizing anti-rat IL-1β antibodies had no effect. These observations indicate that secretion of IL-1α from macrophages stimulates alveolar epithelial cells to secrete chemokines that can elicit an inflammatory response. PMID:17901407

  18. Ozone autohemotherapy induces long-term cerebral metabolic changes in multiple sclerosis patients.

    PubMed

    Molinari, F; Simonetti, V; Franzini, M; Pandolfi, S; Vaiano, F; Valdenassi, L; Liboni, W

    2014-01-01

    Ozone autohemotherapy is an emerging therapeutic technique that is gaining increasing importance in treating neurological disorders. A validated and standard methodology to assess the effect of such therapy on brain metabolism and circulation is however still lacking. We used a near-infrared spectroscopy (NIRS) system to monitor the cerebral metabolism and a transcranial Doppler (TCD) to monitor the blood flow velocity in the middle cerebral arteries. Fifty-four subjects (32 neurological patients and 22 controls) were tested before, during, and after ozone autohemotherapy. We monitored the concentration changes in the level of oxygenated and deoxygenated haemoglobin, and in the level of the Cytochrome-c-oxidase (CYT-c). As a primary endpoint of the work, we showed the changes in the brain metabolism and circulation of the entire population. The concentration of oxygenated haemoglobin increased after the reinjection of the ozoned blood and remained higher than the beginning for another 1.5 hours. The concentration of the deoxygenated haemoglobin decreased during the therapy and the CYT-c concentration markedly increased about 1 hour after the reinjection. No significant changes were observed on the blood flow velocity. As secondary endpoint, we compared the NIRS metabolic pattern of 20 remitting-relapsing multiple sclerosis (MS) patients against 20 controls. We showed that by using only 7 NIRS variables it was possible to characterize the metabolic brain pattern of the two groups of subjects. The MS subjects showed a marked increase of the CYT-c activity and concentration about 40 minutes after the end of the autohemotherapy, possibly revealing a reduction of the chronic oxidative stress level typical of MS sufferers. From a technical point of view, this preliminary study showed that NIRS could be useful to show the effects of ozone autohemotherapy at cerebral level, in a long-term monitoring. The clinical result of this study is the quantitative measurement of the

  19. Terminal automation system maintenance

    SciTech Connect

    Coffelt, D.; Hewitt, J.

    1997-01-01

    Nothing has improved petroleum product loading in recent years more than terminal automation systems. The presence of terminal automation systems (TAS) at loading racks has increased operational efficiency and safety and enhanced their accounting and management capabilities. However, like all finite systems, they occasionally malfunction or fail. Proper servicing and maintenance can minimize this. And in the unlikely event a TAS breakdown does occur, prompt and effective troubleshooting can reduce its impact on terminal productivity. To accommodate around-the-clock loading at racks, increasingly unattended by terminal personnel, TAS maintenance, servicing and troubleshooting has become increasingly demanding. It has also become increasingly important. After 15 years of trial and error at petroleum and petrochemical storage and transfer terminals, a number of successful troubleshooting programs have been developed. These include 24-hour {open_quotes}help hotlines,{close_quotes} internal (terminal company) and external (supplier) support staff, and {open_quotes}layered{close_quotes} support. These programs are described.

  20. Tropospheric Ozone and Photochemical Smog

    NASA Astrophysics Data System (ADS)

    Sillman, S.

    2003-12-01

    The question of air quality in polluted regions represents one of the issues of geochemistry with direct implications for human well-being. Human health and well-being, along with the well-being of plants, animals, and agricultural crops, are dependent on the quality of air we breathe. Since the start of the industrial era, air quality has become a matter of major importance, especially in large cities or urbanized regions with heavy automobile traffic and industrial activity.Concern over air quality existed as far back as the 1600s. Originally, polluted air in cities resulted from the burning of wood or coal, largely as a source of heat. The industrial revolution in England saw a great increase in the use of coal in rapidly growing cities, both for industrial use and domestic heating. London suffered from devastating pollution events during the late 1800s and early 1900s, with thousands of excess deaths attributed to air pollution (Brimblecombe, 1987). With increasing use of coal, other instances also occurred in continental Europe and the USA. These events were caused by directly emitted pollutants (primary pollutants), including sulfur dioxide (SO2), carbon monoxide (CO), and particulates. They were especially acute in cities with northerly locations during fall and winter when sunlight is at a minimum. These original pollution events gave rise to the term "smog" (a combination of smoke and fog). Events of this type have become much less severe since the 1950s in Western Europe and the US, as natural gas replaced coal as the primary source of home heating, industrial smokestacks were designed to emit at higher altitudes (where dispersion is more rapid), and industries were required to install pollution control equipment.Beginning in the 1950s, a new type of pollution, photochemical smog, became a major concern. Photochemical smog consists of ozone (O3) and other closely related species ("secondary pollutants") that are produced photochemically from directly

  1. Maintenance of hydrostatic transmissions

    NASA Astrophysics Data System (ADS)

    Esposito, A.

    1981-10-01

    Problems in hydrostatic transmission maintenance are identified and ways of overcoming them are suggested. It is found that problems arise from lack of lubrication, impurities in the oil, and cavitation at the pump and at the motor. It is under suggested that under nonsevere operating conditions, oil and filter should be changed every year, or every 1500 to 2000 hr running time. Under severe operating conditions or in dusty environments, the interval should be every 6 months or 1000 hr.

  2. Flight Crew Health Maintenance

    NASA Technical Reports Server (NTRS)

    Gullett, C. C.

    1970-01-01

    The health maintenance program for commercial flight crew personnel includes diet, weight control, and exercise to prevent heart disease development and disability grounding. The very high correlation between hypertension and overweight in cardiovascular diseases significantly influences the prognosis for a coronary prone individual and results in a high rejection rate of active military pilots applying for civilian jobs. In addition to physical fitness the major items stressed in pilot selection are: emotional maturity, glucose tolerance, and family health history.

  3. Proposed SOLCOST maintenance activities

    SciTech Connect

    1980-01-01

    This document provides a short description of work that has been accomplished to date and work in progress. A discussion of the program status as it is currently configured follows and finally proposed work by Solar Environmental Engineering Company (SEEC) in its most recently signed contract with the Department of Energy (DOE) is given. Early statements are designed to give the reader a good background so that the suggested SOLCOST maintenance activities will be more easily understood.

  4. A Chemiluminescence Detector for Ozone Measurement.

    ERIC Educational Resources Information Center

    Carroll, H.; And Others

    An ozone detector was built and evaluated for its applicability in smog chamber studies. The detection method is based on reaction of ozone with ethylene and measurement of resultant chemiluminescence. In the first phase of evaluation, the detector's response to ozone was studied as a function of several instrument parameters, and optimum…

  5. KINETICS MODEL AND OZONE ISOPLETH PLOTTING PACKAGE

    EPA Science Inventory

    The Kinetics Model and Ozone Isopleth Plotting Package (OZIPP) computer program can be used to simulate ozone formation in urban atmospheres. OZIPP calculates maximum one-hour average ozone concentrations given a set of input assumptions about initial precursor concentrations, li...

  6. IDENTIFICATION OF BROMOHYDRINS IN OZONATED WATERS

    EPA Science Inventory

    Because ozonation is becoming a popular alternative to chlorination for disinfection of drinking water and because little is known about the potential adverse effects of ozonation disinfection by-products (DBPs), we have sought to identify ozone DBPs, particularly brominated orga...

  7. Ozone, Climate, and Global Atmospheric Change.

    ERIC Educational Resources Information Center

    Levine, Joel S.

    1992-01-01

    Presents an overview of global atmospheric problems relating to ozone depletion and global warming. Provides background information on the composition of the earth's atmosphere and origin of atmospheric ozone. Describes causes, effects, and evidence of ozone depletion and the greenhouse effect. A vignette provides a summary of a 1991 assessment of…

  8. AUTOMOTIVE DIESEL MAINTENANCE. PROGRAM OUTLINE.

    ERIC Educational Resources Information Center

    Human Engineering Inst., Cleveland, OH.

    INFORMATIONAL TOPICS COVERED IN THE TEXT MATERIALS AND SELF-INSTRUCTIONAL BRANCH PROGRAMED TRAINING FILMS FOR A 2-YEAR, 55 MODULE PROGRAM IN AUTOMOTIVE DIESEL MAINTENANCE ARE GIVEN. THE 30 MODULES FOR "AUTOMOTIVE DIESEL MAINTENANCE 1" ARE AVAILABLE AS VT 005 655 - VT 005 684, AND THE 25 MODULES FOR "AUTOMOTIVE DIESEL MAINTENANCE 2" ARE AVAILABLE…

  9. PREVENTIVE MAINTENANCE. HONEYWELL PLANNING GUIDE.

    ERIC Educational Resources Information Center

    Honeywell, Inc., Minneapolis, Minn.

    THIS HONEYWELL PAMPHLET DISCUSSES SOME ASPECTS OF PREVENTIVE MAINTENANCE OF AUTOMATIC CONTROLS, HEATING, VENTILATING, AND AIR CONDITIONING, AND COMPARES IN-PLANT WITH CONTRACT SERVICE, CONCLUDING THAT CONTRACT SERVICE IS PREFERABLE AND DESCRIBING A NUMBER OF MAINTENANCE PLANS WHICH THEY FURNISH. PREVENTIVE MAINTENANCE PROVIDES--(1) MORE EFFICIENT…

  10. Designing with Maintenance in Mind.

    ERIC Educational Resources Information Center

    Hoffman, Kisty

    2002-01-01

    When planning for a new facility, consideration of maintenance needs is crucial to successful design. Designing for maintenance needs involves considering such factors as the durability of materials used, the cost and lifecycle of the materials, and the flexibility of the maintenance staff. Stresses the importance of including key members of the…

  11. Antarctic Ozone: Theory and Observation.

    NASA Astrophysics Data System (ADS)

    Salawitch, Ross Jay

    The amount of ozone observed in October over Antarctica has fallen steadily and precipitously in the last decade. Observational data describing the phenomenology of the Antarctic ozone reduction are reviewed, followed by the presentation of theories that seek to account for the observed ozone reductions while satisfying other available constraints. We begin with a discussion of the thermodynamic properties of solid phases containing HCl and HNO_3. The presence of clouds in the Antarctic stratosphere, caused be extremely low temperatures during spring, leads to condensation and precipitation of HNO_3, and condensation and reaction of HCl. Both processes lead to the conversion of unreactive forms of chlorine to chlorine oxides, which participate in a sequence of chemical reactions that consume ozone. A chemical model that incorporates the influence of cloud catalyzed heterogeneous reactions is compared in detail to the interferometric measurements of HCl, ClNO_3, HNO_3 , NO_2, and NO obtained over Antarctica during the spring of 1986 (Farmer et al., 1987). Model results are consistent with observed temporal trends of these species and with trends for total column ozone reported by Stolarski et al. (1986). Loss of ozone is attributed to the catalytic influence of chlorine and bromine radicals, in cycles suggested by McElroy et al. (1986b) and Molina and Molina (1987). Constraints are then placed on the abundance of stratospheric bromine by analysis of observations of OClO over Antarctica during the spring of 1986 (Solomon et al., 1987a). The diurnal variation of OClO is consistent with 16 +/- 4 ppt of stratospheric bromine if a fraction of the overall ClO + BrO reaction proceeds through a channel resulting in the production of BrCl. Bromine levels in this range would contribute approximately 20% of the total ozone loss. Finally, it is shown that the production of reactive chlorine oxides by heterogeneous processes depends on the initial concentration of HCl relative

  12. Options to accelerate ozone recovery:ozone and climate benefits

    NASA Astrophysics Data System (ADS)

    Daniel, J. S.; Fleming, E. L.; Portmann, R. W.; Velders, G. J. M.; Jackman, C. H.; Ravishankara, A. R.

    2010-04-01

    Hypothetical reductions in future emissions of ozone-depleting substances (ODSs), including N2O, are evaluated in terms of effects on equivalent effective stratospheric chlorine (EESC), globally-averaged total column ozone, and radiative forcing through 2100. Due to the established success of the Montreal Protocol, these actions can have only a fraction of the impact that regulations already in force have had. If all anthropogenic ODS emissions were halted beginning in 2011, ozone is calculated to be higher by about 1-2{%} during the period 2030-2100 compared to a case of no additional ODS restrictions. Radiative forcing by 2100 would be about 0.23 W/m2 lower due to the elimination of N2O emissions and about 0.005 W/m2 lower due to destruction of the chlorofluorocarbon (CFC) bank. The ability of EESC to be a suitable metric for total ozone is also quantified. Responding to the recent suggestion that N2O should be considered an ODS, we provide an approach to incorporate N2O into the EESC formulation.

  13. Options to Accelerate Ozone Recovery: Ozone and Climate Benefits

    NASA Technical Reports Server (NTRS)

    Fleming, E. L.; Daniel, J. S.; Portmann, R. W.; Velders, G. J. M.; Jackman, C. H.; Ravishankara, A. R.

    2010-01-01

    The humankind or anthropogenic influence on ozone primarily originated from the chlorofluorocarbons and halons (chlorine and bromine). Representatives from governments have met periodically over the years to establish international regulations starting with the Montreal Protocol in 1987, which greatly limited the release of these ozone-depleting substances (DDSs). Two global models have been used to investigate the impact of hypothetical reductions in future emissions of ODSs on total column ozone. The investigations primarily focused on chlorine- and bromine-containing gases, but some computations also included nitrous oxide (N2O). The Montreal Protocol with ODS controls have been so successful that further regulations of chlorine- and bromine-containing gases could have only a fraction of the impact that regulations already in force have had. if all anthropogenic ODS emissions were halted beginning in 2011, ozone is calculated to be higher by about 1-2% during the period 2030-2100 compared to a case of no additional ODS restrictions. Chlorine- and bromine-containing gases and nitrous oxide are also greenhouse gases and lead to warming of the troposphere. Elimination of N 20 emissions would result in a reduction of radiative forcing of 0.23 W/sq m in 2100 than presently computed and destruction of the CFC bank would produce a reduction in radiative forcing of 0.005 W/sq m in 2100. This paper provides a quantitative way to consider future regulations of the CFC bank and N 20 emissions

  14. Ozone heating in the Martian atmosphere

    NASA Technical Reports Server (NTRS)

    Lindner, Bernhard L.

    1991-01-01

    In addition to establishing that ozone constitutes a nonnegligible but only minor heat source in the Martian atmosphere, it is presently shown that the ozone abundance's hemispherical asymmetry is an improbable factor in the establishment of the polar caps' observed hemispherical asymmetry, since ozone absorbs less than 1 percent of the total solar flux incident on the polar caps. In the remaining hypothesized roles for Martian atmospheric ozone considered, namely those of cloud formation and snowfall, ozone heating remains nonnegligible but appears overstated by previous studies.

  15. SSTs, nitrogen fertiliser and stratospheric ozone

    NASA Technical Reports Server (NTRS)

    Turco, R. P.; Whitten, R. C.; Poppoff, I. G.; Capone, L. A.

    1978-01-01

    A recently revised model of the stratosphere is used to show that a substantial enhancement in the ozone layer could accompany worldwide SST fleet operations and that water vapor may be an important factor in SST assessments. Revised rate coefficients for various ozone-destroying reactions are employed in calculations which indicate a slight increase in the total content of stratospheric ozone for modest-sized fleets of SSTs flying below about 25 km. It is found that water-vapor chemical reactions can negate in large part the NOx-induced ozone gains computed below 25 km and that increased use of nitrogen fertilizer might also enhance the ozone layer.

  16. General aviation avionics equipment maintenance

    NASA Technical Reports Server (NTRS)

    Parker, C. D.; Tommerdahl, J. B.

    1978-01-01

    Maintenance of general aviation avionics equipment was investigated with emphasis on single engine and light twin engine general aviation aircraft. Factors considered include the regulatory agencies, avionics manufacturers, avionics repair stations, the statistical character of the general aviation community, and owners and operators. The maintenance, environment, and performance, repair costs, and reliability of avionics were defined. It is concluded that a significant economic stratification is reflected in the maintenance problems encountered, that careful attention to installations and use practices can have a very positive impact on maintenance problems, and that new technologies and a general growth in general aviation will impact maintenance.

  17. Tropospheric Enhancement of Ozone over the UAE

    NASA Astrophysics Data System (ADS)

    Abbasi, Naveed Ali; Majeed, Tariq; Iqbal, Mazhar; Kaminski, Jacek; Struzewska, Joanna; Durka, Pawel; Tarasick, David; Davies, Jonathan

    2015-04-01

    We use the Global Environmental Multiscale - Air Quality (GEM-AQ) model to interpret the vertical profiles of ozone acquired with ozone sounding experiments at the meteorological site located at the Abu Dhabi airport. The purpose of this study is to gain insight into the chemical and dynamical structures in the atmosphere of this unique subtropical location (latitude 24.45N; longitude 54.22E). Ozone observations for years 2012 - 2013 reveal elevated ozone abundances in the range from 70 ppbv to 120 ppbv near 500-400 hPa during summer. The ozone abundances in other seasons are much lower than these values. The preliminary results indicate that summertime enhancement in ozone is associated with the Arabian anticyclones centered over the Zagros Mountains in Iran and the Asir and Hijaz Mountain ranges in Saudi Arabia, and is consistent with TES observations of deuterated water. The model also shows considerable seasonal variation in the tropospheric ozone which is transported from the stratosphere by dynamical processes. The domestic production of ozone in the middle troposphere is estimated and compared GEM-AQ model. It is estimated that about 40-50% of ozone in the UAE is transported from the neighbouring petrochemical industries in the Gulf region. We will present ozone sounding data and GEM-AQ results including a discussion on the high levels of the tropospheric ozone responsible for contaminating the air quality in the UAE. This work is supported by National Research Foundation, UAE.

  18. Ozone Reductions Using Residential Building Envelopes

    SciTech Connect

    Walker, Iain S.; Sherman, Max; Nazaroff, William W.

    2009-02-01

    Ozone is an air pollutant with that can have significant health effects and a significant source of ozone in some regions of California is outdoor air. Because people spend the vast majority of their time indoors, reduction in indoor levels of ozone could lead to improved health for many California residents. Ozone is removed from indoor air by surface reactions and can also be filtered by building envelopes. The magnitude of the envelope impact depends on the specific building materials that the air flows over and the geometry of the air flow paths through the envelope that can be changes by mechanical ventilation operation. The 2008 Residential Building Standards in California include minimum requirements for mechanical ventilation by referencing ASHRAE Standard 62.2. This study examines the changes in indoor ozone depending on the mechanical ventilation system selected to meet these requirements. This study used detailed simulations of ventilation in a house to examine the impacts of different ventilation systems on indoor ozone concentrations. The simulation results showed that staying indoors reduces exposure to ozone by 80percent to 90percent, that exhaust ventilation systems lead to lower indoor ozone concentrations, that opening of windows should be avoided at times of high outdoor ozone, and that changing the time at which mechanical ventilation occurs has the ability to halve exposure to ozone. Future work should focus on the products of ozone reactions in the building envelope and the fate of these products with respect to indoor exposures.

  19. Trends in total column ozone measurements

    NASA Technical Reports Server (NTRS)

    Rowland, F. S.; Angell, J.; Attmannspacher, W.; Bloomfield, P.; Bojkov, R. D.; Harris, N.; Komhyr, W.; Mcfarland, M.; Mcpeters, R.; Stolarski, R. S.

    1989-01-01

    It is important to ensure the best available data are used in any determination of possible trends in total ozone in order to have the most accurate estimates of any trends and the associated uncertainties. Accordingly, the existing total ozone records were examined in considerable detail. Once the best data set has been produced, the statistical analysis must examine the data for any effects that might indicate changes in the behavior of global total ozone. The changes at any individual measuring station could be local in nature, and herein, particular attention was paid to the seasonal and latitudinal variations of total ozone, because two dimensional photochemical models indicate that any changes in total ozone would be most pronounced at high latitudes during the winter months. The conclusions derived from this detailed examination of available total ozone can be split into two categories, one concerning the quality and the other the statistical analysis of the total ozone record.

  20. Ozone Depletion, UVB and Atmospheric Chemistry

    NASA Technical Reports Server (NTRS)

    Stolarski, Richard S.

    1999-01-01

    The primary constituents of the Earth's atmosphere are molecular nitrogen and molecular oxygen. Ozone is created when ultraviolet light from the sun photodissociates molecular oxygen into two oxygen atoms. The oxygen atoms undergo many collisions but eventually combine with a molecular oxygen to form ozone (O3). The ozone molecules absorb ultraviolet solar radiation, primarily in the wavelength region between 200 and 300 nanometers, resulting in the dissociation of ozone back into atomic oxygen and molecular oxygen. The oxygen atom reattaches to an O2 molecule, reforming ozone which can then absorb another ultraviolet photon. This sequence goes back and forth between atomic oxygen and ozone, each time absorbing a uv photon, until the oxygen atom collides with and ozone molecule to reform two oxygen molecules.

  1. Natural hydrocarbons, urbanization, and urban ozone

    NASA Technical Reports Server (NTRS)

    Cardelino, C. A.; Chameides, W. L.

    1990-01-01

    The combined effects of emission control and urbanization, with its concomitant intensification of the urban heat island, on urban ozone concentrations are studied. The effect of temperature on ozone is considered, and attention is given to the temperature effect on ozone photochemistry. Model calculations suggest that ozone concentration enhancements are caused by the effect of temperature on the atmospheric chemistry of peroxyacetyl nitrate, as well as the temperature dependence of natural and anthropogenic hydrocarbon emissions. It is pointed out that, because of the sensitivity of urban ozone to local climatic conditions and the ability of trees to moderate summertime temperatures, the inadvertent removal of trees from urbanization can have an adverse effect on urban ozone concentration, while a temperature increase in the urban heat island caused by urbanization can essentially cancel out the ozone-reducing benefits obtained from a 50-percent reduction in anthropogenic hydrocarbon emissions.

  2. Guideline for developing an ozone forecasting program

    SciTech Connect

    Dye, T.S.; MacDonald, C.P.; Anderson, C.B.

    1999-07-01

    The purpose of this document is to provide guidance to help air quality agencies develop, operate, and evaluate ozone forecasting programs. This guidance document provides: Background information about ozone and the weather`s effect on ozone; A list of how ozone forecasts are currently used; A summary and evaluation of methods currently used to forecast ozone; and Steps you can follow to develop and operate an ozone forecasting program. The intended audience of this document is project managers, meteorologists, air quality analysts, and data analysts. Project managers can learn about the level of effort needed to set up and operate a forecasting program. Meteorologists can learn about the various methods to predict ozone and the steps needed to create a program.

  3. Formation of the 1988 Antarctic ozone hole

    SciTech Connect

    Krueger, A.J.; Stolarski, R.S.; Schoeberl, M.R. )

    1989-05-01

    The 1988 Antarctic ozone hole, as observed with the Nimbus 7 TOMS instrument, formed in August but failed to deepen significantly during September. The structure of the surrounding total ozone maxima also differed from the prior year. The 1987 total ozone pattern was pole centered and symmetrical. During 1988 a persistent strong wavenumber 1 perturbation in total ozone developed in August which resulted in displacement of the polar ozone minimum to the base of the Antarctic Peninsula. Subsequently, a series of transient events diminished and a larger scale decrease in polar total ozone began. The decrease lasted less than two weeks, resulting in a net change of only 25 DU compared with the nearly 100 DU decline observed during the same period in 1987. The minimum values remained roughly constant until October 19, 1988 and then increased rapidly. The 1988 Antarctic ozone hole subsequently drifted off the Antarctic continent in late October and dissipated in mid-November.

  4. The Recovery of the Antarctic Ozone Hole

    NASA Technical Reports Server (NTRS)

    Newman, Paul A.

    2004-01-01

    The ozone hole is a massive loss of ozone that annually occurs over Antarctica during the Austral spring (August-November). Man-made chlorine and bromine compounds cause the ozone hole. As opposed to local urban pollution, the hole illustrates how man-made chemicals can affect the atmosphere over enormous regions remote from their release point. These chlorine and bromine gases have long lifetimes in the atmosphere; hence, the ozone hole will slowly recover into the next few decades. In this talk I will briefly cover some of the history of the Antarctic ozone hole and the theory behind the phenomena. I will then discuss the recovery of ozone over Antarctica. State-of-the-art computer models project the recovery of the ozone hole to 1980 levels by about 2050. However, this recovery may be affected by greenhouse warming.

  5. Height resolved ozone hole structure as observed by the Global Ozone Monitoring Experiment-2

    NASA Astrophysics Data System (ADS)

    van Peet, J. C. A.; van der A, R. J.; de Laat, A. T. J.; Tuinder, O. N. E.; König-Langlo, G.; Wittig, J.

    2009-06-01

    We present Global Ozone Monitoring Experiment-2 (GOME-2) ozone profiles that were operationally retrieved with the KNMI Ozone ProfilE Retrieval Algorithm (OPERA) algorithm for the period September-December 2008. It is shown that it is possible to accurately measure the vertical distribution of stratospheric ozone for Antarctic ozone hole conditions from spectra measured at ultraviolet wavelengths from a nadir viewing instrument. Comparisons with ozone sonde observations from the Neumayer station at the Antarctic coast show a good agreement for various ozone profile shapes representing different phases of the annual recurring ozone hole cycle. A preliminary analysis of the three-dimensional structure of the ozone hole shows for example that at the vortex edges ozone rich mid-latitude middle and upper stratospheric layers can be found over ozone depleted lower stratospheric ‘ozone hole’ layers. These Antarctic ozone profile observations combined with the daily global coverage of GOME-2 enables the monitoring of the three-dimensional structure of the ozone hole on a daily basis.

  6. A total ozone-dependent ozone profile climatology based on ozonesondes and Aura MLS data

    NASA Astrophysics Data System (ADS)

    Labow, Gordon J.; Ziemke, Jerald R.; McPeters, Richard D.; Haffner, David P.; Bhartia, Pawan K.

    2015-03-01

    Ozone profiles measured with the Aura Microwave Limb Sounder (MLS) and ozonesondes are used to create a new ozone climatology that can be used for satellite retrievals and radiative transfer studies. The climatology is binned according to total column ozone amount and latitude rather than with season. Because of high correlation between ozone profile shape and total ozone, the ozone profiles in this climatology capture ozone variations well, especially near the tropopause. This climatology has been constructed from nearly a million individual MLS ozone profile measurements taken between 2004 and 2013 as well as over 55,000 ozonesonde measurements from 1988 to 2011. The MLS profiles were sorted by total column ozone as measured by Ozone Monitoring Instrument in observations that were coincident with the MLS measurements. The data from the sondes were used in the troposphere and lower stratosphere and MLS in the middle and upper stratosphere. These two data sets were blended together between 13 and 17 km (~159-88 hPa). This climatology consists of average ozone profiles as a function of total ozone for six 30° latitude bands covering altitudes between 0 and 75 km (in Z* pressure altitude coordinates) as well as the corresponding standard deviations for each layer. There is no seasonal component. This new climatology shows some remarkable and somewhat unexpected correlations between the total column ozone and the ozone amount at some layers, particularly in the lower and middle troposphere in some latitude bands.

  7. Arctic stratospheric ozone depletion and increased UVB radiation: potential impacts to human health.

    PubMed

    De Fabo, Edward C

    2005-12-01

    Contrary to popular belief, stratospheric ozone depletion, and the resultant increase in solar UV-B (280-320 nm), are unlikely to fully recover soon. Notwithstanding the success of the Montreal Protocol in reducing the amount of ozone destroying chemicals into the stratosphere, the life-times of these compounds are such that even with full compliance with the Protocol by all countries, it will be decades before stratospheric ozone could return to pre-1980 levels. This raises the question, therefore, of what will happen to biological processes essential to the maintenance of life on earth which are sensitive to damage by increased UV-B radiation, particularly those involved with human health? The polar regions, because of the vagaries of climate and weather, are the bellwether for stratospheric ozone depletion and will, therefore, be the first to experience impacts due to increases in solar UV-B radiation. The impacts of these are incompletely understood and cannot be predicted with certainty. While some UV-B impacts on human health are recognized, much is unknown, unclear and uncertain. Thus, this paper attempts, as a first approximation, to point out potential impacts to the health and welfare of human inhabitants of the Arctic due to increased solar UV-B radiation associated with stratospheric ozone depletion. As will be seen, much more data is critically needed before adequate risk assessment can occur. PMID:16440613

  8. Ozone NAAQS Review: Policy Assessment

    EPA Science Inventory

    Ozone is one of the six major air pollutants for which EPA has issued air quality criteria and established national ambient air quality standards (NAAQS) based on those criteria. The Clean Air Act (CAA) requires EPA to periodically review and revise, as appropriate, existing air...

  9. Ozone depletion, paradigms, and politics

    SciTech Connect

    Iman, R.L.

    1993-10-01

    The destruction of the Earth`s protective ozone layer is a prime environmental concern. Industry has responded to this environmental problem by: implementing conservation techniques to reduce the emission of ozone-depleting chemicals (ODCs); using alternative cleaning solvents that have lower ozone depletion potentials (ODPs); developing new, non-ozone-depleting solvents, such as terpenes; and developing low-residue soldering processes. This paper presents an overview of a joint testing program at Sandia and Motorola to evaluate a low-residue (no-clean) soldering process for printed wiring boards (PWBs). Such processes are in widespread use in commercial applications because they eliminate the cleaning operation. The goal of this testing program was to develop a data base that could be used to support changes in the mil-specs. In addition, a joint task force involving industry and the military has been formed to conduct a follow-up evaluation of low-residue processes that encompass the concerns of the tri-services. The goal of the task force is to gain final approval of the low-residue technology for use in military applications.

  10. Atmospheric chemistry: Ethanol and ozone

    NASA Astrophysics Data System (ADS)

    Madronich, Sasha

    2014-06-01

    Ethanol has been heralded as a cleaner fuel for cars than gasoline. An analysis of air quality data suggests that a switch from ethanol to gasoline use in São Paulo in response to changing prices led unexpectedly to lower local levels of ozone pollution.

  11. EVALUATION OF OZONE CALIBRATION PROCEDURES

    EPA Science Inventory

    In October of 1976, the U.S. Environmental Protection Agency announced that the calibration procedure then currently in use for reference methods for the measurement of ozone in the atmosphere -- the neutral buffered potassium iodide procedure -- had been found variable and in so...

  12. Biomedical consequences of ozone depletion

    NASA Astrophysics Data System (ADS)

    Coohill, Thomas P.

    1994-07-01

    It is widely agreed that a portion of the earth's protective stratospheric ozone layer is being depleted. The major effect of this ozone loss will be an increase in the amount of ultraviolet radiation (UV reaching the biosphere. This increase will be completely contained within the UVB (290nm - 320nm). It is imperative that assessments be made of the effects of this additional UVB on living organisms. This requires a detailed knowledge of the UVB photobiology of these life forms. One analytical technique to aid in the approximations is the construction of UV action spectra for such important biological end-points as human skin cancer, cataracts, immune suppression; plant photosynthesis and crop yields; and aquatic organism responses to UVB, especially the phytoplankton. Combining these action spectra with the known solar spectrum (and estimates for various ozone depletion scenarios) can give rise to a series of effectiveness spectra for these parameters. This manuscript gives a first approximation, rough estimate, for the effectiveness spectra for some of these bioresponses, and a series of crude temporary values for how a 10% ozone loss would affect the above end-points. These are not intended to masquerade as final answers, but rather, to serve as beginning attempts for a process which should be continually refined. It is hoped that these estimates will be of some limited use to agencies, such as government and industry, that have to plan now for changes in human activities that might alter future atmospheric chemistry in a beneficial manner.

  13. Ozone: Does It Affect Me?

    ERIC Educational Resources Information Center

    Wilson, Karla G.

    This curriculum unit on the ozone is intended for high school students and contains sections on environmental science and chemistry. It has been structured according to a learning cycle model and contains numerous activities, some of which are in a cooperative learning format. Skills emphasized include laboratory procedures, experimental design,…

  14. Ozone Depletion from Nearby Supernovae

    NASA Technical Reports Server (NTRS)

    Gehrels, Neil; Laird, Claude M.; Jackman, Charles H.; Cannizzo, John K.; Mattson, Barbara J.; Chen, Wan; Bhartia, P. K. (Technical Monitor)

    2002-01-01

    Estimates made in the 1970's indicated that a supernova occurring within tens of parsecs of Earth could have significant effects on the ozone layer. Since that time improved tools for detailed modeling of atmospheric chemistry have been developed to calculate ozone depletion, and advances have been made also in theoretical modeling of supernovae and of the resultant gamma ray spectra. In addition, one now has better knowledge of the occurrence rate of supernovae in the galaxy, and of the spatial distribution of progenitors to core-collapse supernovae. We report here the results of two-dimensional atmospheric model calculations that take as input the spectral energy distribution of a supernova, adopting various distances from Earth and various latitude impact angles. In separate simulations we calculate the ozone depletion due to both gamma rays and cosmic rays. We find that for the combined ozone depletion from these effects roughly to double the 'biologically active' UV flux received at the surface of the Earth, the supernova must occur at approximately or less than 8 parsecs.

  15. Paranal maintenance and CMMS experience

    NASA Astrophysics Data System (ADS)

    Montano, Nelson

    2004-10-01

    During the last four years of operations, low technical downtime has been one of the relevant records of the Paranal Observatory. From the beginning of the Very Large Telescope (VLT) project, European Southern Observatory (ESO) has considered the implementation of a proper maintenance strategy a fundamental point in order to ensure low technical down time and preserve the Observatory's assets. The implementation of the maintenance strategy was based on the following aspects: - Strong maintenance sense during the design stage. Line Replacement Unit (LRU) concept, standardization and modularity of the Observatory equipment - Creation of a dedicated team for Maintenance - The implementation of a Computerized Maintenance Management System After four operational years, the result of these aspects has exceeded the expectations; the Observatory has been operating with high availability under a sustainable strategy. The strengths of the maintenance strategy have been based on modern maintenance concepts applied by regular production companies, where any minute of down time involves high cost. The operation of the actual Paranal Maintenance System is based mainly on proactive activities, such as regular inspections, preventive maintenance (PM) and predictive maintenance (PdM) plans. Nevertheless, it has been necessary to implement a strong plan for corrective maintenance (CM). The Spare Parts Strategy has also been an important point linked to the Maintenance Strategy and CMMS implementation. At present, almost 4,000 items related to the Observatory spare parts are loaded into the CMMS database. Currently, we are studying the implementation of a Reliability Centered Maintenance (RCM) project in one of our critical systems The following document presents the actual status of the Paranal Maintenance Strategy and which have been the motivations to implement the established strategy.

  16. GROMOS-C, a novel ground based microwave radiometer for ozone measurement campaigns

    NASA Astrophysics Data System (ADS)

    Fernandez, S.; Murk, A.; Kämpfer, N.

    2015-03-01

    Stratospheric ozone is of major interest as it absorbs most of harmful UV radiation from the sun, allowing life on Earth. Ground based microwave remote sensing is the only method that allows to measure ozone profiles up to the mesopause, 24 h and under different weather conditions with high time resolution. In this paper a novel ground based microwave radiometer is presented. It is called GROMOS-C (GRound based Ozone MOnitoring System for Campaigns), and it has been designed to measure the vertical profile of ozone distribution in the middle atmosphere, by observing ozone emission spectra at a frequency of 110.836 GHz. The instrument is designed in a compact way which makes it transportable and suitable for outdoor use in campaigns, an advantageous feature that is lacking in present day ozone radiometers. It is operated through remote control. GROMOS-C is a total power radiometer which uses a preamplified heterodyne receiver, and a digital Fast Fourier Transform spectrometer for the spectral analysis. Among its main new features stands out the incorporation of different calibration loads, including a noise diode and a new type of blackbody target specifically designed for this instrument, based on Peltier elements. The calibration scheme does not depend on the use of liquid nitrogen, therefore GROMOS-C can be operated at remote places with no maintenance requirements. In addition the instrument can be switched in frequency to observe the CO line at 115 GHz. A description of the main characteristics of GROMOS-C is included in this paper, as well as the results of a first campaign at the High Altitude Research Station in Jungfraujoch (HFSJ), Switzerland. The validation is performed by comparison of the retrieved profiles against equivalent profiles from MLS satellite data, ECMWF model data, as well as our nearby NDACC ozone radiometer measuring at Bern.

  17. GROMOS-C, a novel ground-based microwave radiometer for ozone measurement campaigns

    NASA Astrophysics Data System (ADS)

    Fernandez, S.; Murk, A.; Kämpfer, N.

    2015-07-01

    Stratospheric ozone is of major interest as it absorbs most harmful UV radiation from the sun, allowing life on Earth. Ground-based microwave remote sensing is the only method that allows for the measurement of ozone profiles up to the mesopause, over 24 hours and under different weather conditions with high time resolution. In this paper a novel ground-based microwave radiometer is presented. It is called GROMOS-C (GRound based Ozone MOnitoring System for Campaigns), and it has been designed to measure the vertical profile of ozone distribution in the middle atmosphere by observing ozone emission spectra at a frequency of 110.836 GHz. The instrument is designed in a compact way which makes it transportable and suitable for outdoor use in campaigns, an advantageous feature that is lacking in present day ozone radiometers. It is operated through remote control. GROMOS-C is a total power radiometer which uses a pre-amplified heterodyne receiver, and a digital fast Fourier transform spectrometer for the spectral analysis. Among its main new features, the incorporation of different calibration loads stands out; this includes a noise diode and a new type of blackbody target specifically designed for this instrument, based on Peltier elements. The calibration scheme does not depend on the use of liquid nitrogen; therefore GROMOS-C can be operated at remote places with no maintenance requirements. In addition, the instrument can be switched in frequency to observe the CO line at 115 GHz. A description of the main characteristics of GROMOS-C is included in this paper, as well as the results of a first campaign at the High Altitude Research Station at Jungfraujoch (HFSJ), Switzerland. The validation is performed by comparison of the retrieved profiles against equivalent profiles from MLS (Microwave Limb Sounding) satellite data, ECMWF (European Centre for Medium-Range Weather Forecast) model data, as well as our nearby NDACC (Network for the Detection of Atmospheric

  18. Computer model predictions of the local effects of large, solid-fuel rocket motors on stratospheric ozone. Technical report

    SciTech Connect

    Zittel, P.F.

    1994-09-10

    The solid-fuel rocket motors of large space launch vehicles release gases and particles that may significantly affect stratospheric ozone densities along the vehicle's path. In this study, standard rocket nozzle and flowfield computer codes have been used to characterize the exhaust gases and particles through the afterburning region of the solid-fuel motors of the Titan IV launch vehicle. The models predict that a large fraction of the HCl gas exhausted by the motors is converted to Cl and Cl2 in the plume afterburning region. Estimates of the subsequent chemistry suggest that on expansion into the ambient daytime stratosphere, the highly reactive chlorine may significantly deplete ozone in a cylinder around the vehicle track that ranges from 1 to 5 km in diameter over the altitude range of 15 to 40 km. The initial ozone depletion is estimated to occur on a time scale of less than 1 hour. After the initial effects, the dominant chemistry of the problem changes, and new models are needed to follow the further expansion, or closure, of the ozone hole on a longer time scale.

  19. Recent Results of Ambient Ozone Monitoring in Southern Sierra Nevada and White Mountains, California

    NASA Astrophysics Data System (ADS)

    Burley, J. D.; Bytnerowicz, A.; Cisneros, R.; Schweizer, D.

    2014-12-01

    Ambient ozone has been monitored in the southern Sierra Nevada and White Mountains of California as 2-week average concentrations with Ogawa passive samplers and as 1-hour average concentrations with 2B Technologies UV absorption monitors. Our summer season investigations have included: (1) an elevational transect (1,237 to 4,342 masl) consisting of 5 sites in the White Mountains (2009 -2014); (2) a west to east southern Sierra Nevada transect consisting of 9 sites at elevations between 510 and 3,490 masl (2012 and 2013); and (3) two sites at the Devils Postpile National Monument at 2,130 masl (2007 - 2014). In the White Mountains average ozone concentrations increased with elevation, reaching the highest values at White Mountain Summit. A strongly pronounced diurnal distribution of ozone was observed at the low elevation site in Bishop (OVS), with low values at night and in the early morning and highest concentrations during mid-day. High elevation sites (Crooked Creek, Barcroft Station and Summit) were characterized by flat ozone curves with similar concentrations during daytime and nighttime, typically around 50 ppb. During the 2013 summer season, two-week averages from passive samplers ranged from 32 to 60 ppb for all White Mountains sites with the highest values at the Summit and the lowest at OVS. Along the southern Sierra Nevada transect, average concentrations in summer 2013 ranged from 36.5 to 54.0 ppb with the highest value recorded at the highest elevation eastern site, Piute Pass, and the lowest at low-elevation and western Shaver Lake site. Prather, Mountain Rest and Shaver Lake sites had the most exceedances of 8 h federal health standard of 75 ppb and the California health standard of 70 ppb. The Devils Postpile site was characterized by low ozone concentrations at night and in the early morning, and late afternoon maxima. In 2007 and 2008 the ozone values measured at Devils Postpile occasionally exceeded the federal health standard, with more

  20. Development of algorithms for using satellite meteorological data sets to study global transport of stratospheric aerosols and ozone

    NASA Technical Reports Server (NTRS)

    Want, P. H.; Deepak, A.

    1985-01-01

    The utilization of stratospheric aerosol and ozone measurements obtained from the NASA developed SAM II and SAGE satellite instruments were investigated for their global scale transports. The stratospheric aerosols showed that during the stratospheric warming of the winter 1978 to 1979, the distribution of the zonal mean aerosol extinction ratio in the northern high latitude exhibited distinct changes. Dynamic processes might have played an important role in maintenance role in maintenance of this zonal mean distribution. As to the stratospheric ozone, large poleward ozone transports are shown to occur in the altitude region from 24 km to 38 km near 55N during this warming. This altitude region is shown to be a transition region of the phase relationship between ozone and temperature waves from an in-phase one above 38 km. It is shown that the ozone solar heating in the upper stratosphere might lead to enhancement of the damping rate of the planetary waves due to infrared radiation alone in agreement with theoretical analyses and an earlier observational study.

  1. A new ozone standard - The vapor pressure of ozone at liquid argon temperatures

    NASA Technical Reports Server (NTRS)

    Mauersberger, K.; Hanson, D.; Morton, J.

    1985-01-01

    The vapor pressure of ozone has been measured at liquid argon temperatures. At the normal boiling point of argon (-185.9 C) an ozone pressure of 0.0405 torr was obtained with an accuracy of + or - 1.5 percent. Increases and decreases in liquid argon temperatures raised and lowered the ozone vapor pressure, respectively. During the vapor pressure measurements the purity of ozone was monitored with a mass spectrometer. The proposed ozone standard will considerably improve the calibration of experiments for atmospheric research, the determination of absorption cross sections and other laboratory ozone studies.

  2. Estimation of ozone with total ozone portable spectroradiometer instruments. I. Theoretical model and error analysis

    NASA Astrophysics Data System (ADS)

    Flynn, Lawrence E.; Labow, Gordon J.; Beach, Robert A.; Rawlins, Michael A.; Flittner, David E.

    1996-10-01

    Inexpensive devices to measure solar UV irradiance are available to monitor atmospheric ozone, for example, total ozone portable spectroradiometers (TOPS instruments). A procedure to convert these measurements into ozone estimates is examined. For well-characterized filters with 7-nm FWHM bandpasses, the method provides ozone values (from 304- and 310-nm channels) with less than 0.4 error attributable to inversion of the theoretical model. Analysis of sensitivity to model assumptions and parameters yields estimates of 3 bias in total ozone results with dependence on total ozone and path length. Unmodeled effects of atmospheric constituents and instrument components can result in additional 2 errors.

  3. Towards automated traceability maintenance.

    PubMed

    Mäder, Patrick; Gotel, Orlena

    2012-10-01

    Traceability relations support stakeholders in understanding the dependencies between artifacts created during the development of a software system and thus enable many development-related tasks. To ensure that the anticipated benefits of these tasks can be realized, it is necessary to have an up-to-date set of traceability relations between the established artifacts. This goal requires the creation of traceability relations during the initial development process. Furthermore, the goal also requires the maintenance of traceability relations over time as the software system evolves in order to prevent their decay. In this paper, an approach is discussed that supports the (semi-) automated update of traceability relations between requirements, analysis and design models of software systems expressed in the UML. This is made possible by analyzing change events that have been captured while working within a third-party UML modeling tool. Within the captured flow of events, development activities comprised of several events are recognized. These are matched with predefined rules that direct the update of impacted traceability relations. The overall approach is supported by a prototype tool and empirical results on the effectiveness of tool-supported traceability maintenance are provided. PMID:23471308

  4. Towards automated traceability maintenance

    PubMed Central

    Mäder, Patrick; Gotel, Orlena

    2012-01-01

    Traceability relations support stakeholders in understanding the dependencies between artifacts created during the development of a software system and thus enable many development-related tasks. To ensure that the anticipated benefits of these tasks can be realized, it is necessary to have an up-to-date set of traceability relations between the established artifacts. This goal requires the creation of traceability relations during the initial development process. Furthermore, the goal also requires the maintenance of traceability relations over time as the software system evolves in order to prevent their decay. In this paper, an approach is discussed that supports the (semi-) automated update of traceability relations between requirements, analysis and design models of software systems expressed in the UML. This is made possible by analyzing change events that have been captured while working within a third-party UML modeling tool. Within the captured flow of events, development activities comprised of several events are recognized. These are matched with predefined rules that direct the update of impacted traceability relations. The overall approach is supported by a prototype tool and empirical results on the effectiveness of tool-supported traceability maintenance are provided. PMID:23471308

  5. Maintenance and supply options

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The object of the Maintenance and Supply Option was to develop a high level operational philosophy related to maintenance and supply operations and incorporate these concepts into the Lunar Base Study. Specific products to be generated during this task were three trade studies and a conceptual design of the Logistic Supply Module. The crew size study was performed to evaluate crew sizes from the baseline size of four to a crew size of eight and determine the preferred crew size. The second trade study was to determine the impact of extending surface stay times and recommend a preferred duration of stay time as a function of crew, consumables, and equipment support capabilities. The third trade study was an evaluation of packaging and storage methods to determine the preferred logistics approach to support the lunar base. A modified scenario was developed and served as the basis of the individual trade studies. Assumptions and guidelines were also developed from experience with Apollo programs, Space Shuttle operations, and Space Station studies. With this information, the trade studies were performed and a conceptual design for the Logistic Supply Module was developed.

  6. Remote maintenance monitoring system

    NASA Technical Reports Server (NTRS)

    Simpkins, Lorenz G. (Inventor); Owens, Richard C. (Inventor); Rochette, Donn A. (Inventor)

    1992-01-01

    A remote maintenance monitoring system retrofits to a given hardware device with a sensor implant which gathers and captures failure data from the hardware device, without interfering with its operation. Failure data is continuously obtained from predetermined critical points within the hardware device, and is analyzed with a diagnostic expert system, which isolates failure origin to a particular component within the hardware device. For example, monitoring of a computer-based device may include monitoring of parity error data therefrom, as well as monitoring power supply fluctuations therein, so that parity error and power supply anomaly data may be used to trace the failure origin to a particular plane or power supply within the computer-based device. A plurality of sensor implants may be rerofit to corresponding plural devices comprising a distributed large-scale system. Transparent interface of the sensors to the devices precludes operative interference with the distributed network. Retrofit capability of the sensors permits monitoring of even older devices having no built-in testing technology. Continuous real time monitoring of a distributed network of such devices, coupled with diagnostic expert system analysis thereof, permits capture and analysis of even intermittent failures, thereby facilitating maintenance of the monitored large-scale system.

  7. Ozone in the Atmosphere: II. The Lower Atmosphere.

    ERIC Educational Resources Information Center

    Phillips, Paul; Pickering, Pam

    1991-01-01

    Described are the problems caused by the increased concentration of ozone in the lower atmosphere. Photochemical pollution, mechanisms of ozone production, ozone levels in the troposphere, effects of ozone on human health and vegetation, ozone standards, and control measures are discussed. (KR)

  8. Catching our breath: Next steps for reducing urban ozone

    SciTech Connect

    Not Available

    1989-07-01

    Contents include: summary; ozone and the Clean Air Act; health effects of ozone; effects of ozone on crops and forests; lowering ozone; effect of controlling volatile organic compounds and nitrogen oxides; controlling emissions of volatile organic compounds; new opportunities for controlling ozone; and policy options.

  9. 22 CFR 120.38 - Maintenance levels.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... § 120.38 Maintenance levels. (a) Organizational-level maintenance (or basic-level maintenance) is the first level of maintenance that can be performed “on-equipment” (directly on the defense article or... defense article. (b) Intermediate-level maintenance is second-level maintenance performed...

  10. Trends analyses of 30 years of ambient 8 hour ozone and precursor monitoring data in the South Central U.S.: progress and challenges.

    PubMed

    Sather, Mark E; Cavender, Kevin

    2016-07-13

    In the last 30 years ambient ozone concentrations have notably decreased in the South Central U.S. Yet, current ambient ozone concentrations measured over the past three years 2013-2015 in this area of the U.S. are not meeting the U.S. 2015 8 hour ozone standard of 70 parts per billion (ppb). This paper provides an update on long-term trends analyses of ambient 8 hour ozone and ozone precursor monitoring data collected over the past 30 years (1986-2015) in four South Central U.S. cities, following up on two previously published reviews of 20 and 25 year trends for these cities. All four cities have benefitted from national ozone precursor controls put in place during the 1990s and 2000s involving cleaner vehicles (vehicle fleet turnover/replacement over time), cleaner fuels, cleaner gasoline and diesel engines, and improved inspection/maintenance programs for existing vehicles. Additional ozone precursor emission controls specific to each city are detailed in this paper. The controls have resulted in impressive ambient ozone and ambient ozone precursor concentration reductions in the four South Central U.S. cities over the past 30 years, including 31-70% ambient nitrogen oxides (NOx) concentration declines from historical peaks to the present, 43-72% volatile organic compound (VOC) concentration declines from historical peaks to the present, a related 45-76% VOC reactivity decline for a subset of VOC species from historical peaks to the present, and an 18-38 ppb reduction in city 8 hour ozone design value concentrations. A new challenge for each of the four South Central U.S. cities will be meeting the U.S. 2015 8 hour ozone standard of 70 ppb. PMID:27282109

  11. Improved monitoring of surface ozone by joint assimilation of geostationary satellite observations of ozone and CO

    NASA Astrophysics Data System (ADS)

    Zoogman, Peter; Jacob, Daniel J.; Chance, Kelly; Worden, Helen M.; Edwards, David P.; Zhang, Lin

    2014-02-01

    Future geostationary satellite observations of tropospheric ozone aim to improve monitoring of surface ozone air quality. However, ozone retrievals from space have limited sensitivity in the lower troposphere (boundary layer). Data assimilation in a chemical transport model can propagate the information from the satellite observations to provide useful constraints on surface ozone. This may be aided by correlated satellite observations of carbon monoxide (CO), for which boundary layer sensitivity is easier to achieve. We examine the potential of concurrent geostationary observations of ozone and CO to improve constraints on surface ozone air quality through exploitation of ozone-CO model error correlations in a joint data assimilation framework. The hypothesis is that model transport errors diagnosed for CO provide information on corresponding errors in ozone. A paired-model analysis of ozone-CO error correlations in the boundary layer over North America in summer indicates positive error correlations in continental outflow but negative regional-scale error correlations over land, the latter reflecting opposite sensitivities of ozone and CO to boundary layer depth. Aircraft observations from the ICARTT campaign are consistent with this pattern but also indicate strong positive error correlations in fine-scale pollution plumes. We develop a joint ozone-CO data assimilation system and apply it to a regional-scale Observing System Simulation Experiment (OSSE) of the planned NASA GEO-CAPE geostationary mission over North America. We find substantial benefit from joint ozone-CO data assimilation in informing US ozone air quality if the instrument sensitivity for CO in the boundary layer is greater than that for ozone. A high-quality geostationary measurement of CO could potentially relax the requirements for boundary layer sensitivity of the ozone measurement. This is contingent on accurate characterization of ozone-CO error correlations. A finer-resolution data

  12. Ozone kinetics in low-pressure discharges

    NASA Astrophysics Data System (ADS)

    Guerra, Vasco; Marinov, Daniil; Guaitella, Olivier; Rousseau, Antoine

    2012-10-01

    Ozone kinetics is quite well established at atmospheric pressure, due to the importance of ozone in atmospheric chemistry and to the development of industrial ozone reactors. However, as the pressure is decreased and the dominant three-body reactions lose importance, the main mechanisms involved in the creation and destruction of ozone are still surrounded by important uncertainties. In this work we develop a self-consistent model for a pulsed discharge and its afterglow operating in a Pyrex reactor with inner radius 1 cm, at pressures in the range 1-5 Torr and discharge currents of 40-120 mA. The model couples the electron Boltzmann equation with a system of equations for the time evolution of the heavy particles. The calculations are compared with time-dependent measurements of ozone and atomic oxygen. Parametric studies are performed in order to clarify the role of vibrationally excited ozone in the overall kinetics and to establish the conditions where ozone production on the surface may become important. It is shown that vibrationally excited ozone does play a significant role, by increasing the time constants of ozone formation. Moreover, an upper limit for the ozone formation at the wall in these conditions is set at 10(-4).

  13. Quantitative characterization of the Antarctic ozone hole

    NASA Technical Reports Server (NTRS)

    Ito, T.; Sakoda, Y.; Matsubara, K.; Takao, T.; Akagi, K.; Watanabe, Y.; Shibata, S.; Naganuma, H.

    1994-01-01

    The long-term evolution of the Antarctic ozone hole is studied based on the TOMS data and the JMA data-set of stratospheric temperature in relation with the possible role of polar stratospheric clouds (PSC's). The effective mass of depleted ozone in the ozone hole at its annual mature stage reached a historical maximum of 55 Mt in 1991, 4.3 times larger than in 1981. The ozone depletion rate during 30 days before the mature ozone hole does not show any appreciable long-term trend but the interannual fluctuations do, ranging from 0.169 to 0.689 Mt/day with the average of 0.419 Mt/day for the period of 1979 - 1991. The depleted ozone mass has the highest correlation with the region below 195 K on the 30 mb surface in June, whereas the ozone depletion rate correlates most strongly with that in August. The present result strongly suggests that the long-term evolution of the mature ozone hole is caused both by the interannual change of the latitudinal coverage of the early PSC's, which may control the latitude and date of initiation of ozone decrease, and by that of the spatial coverage of the mature PSC's which may control the ozone depletion rate in the Antarctic spring.

  14. Ozonized oils: a qualitative and quantitative analysis.

    PubMed

    Guinesi, Adriana Simionatto; Andolfatto, Carolina; Bonetti Filho, Idomeo; Cardoso, Arnaldo Alves; Passaretti Filho, Juliano; Farac, Roberta Vieira

    2011-01-01

    Most of the problems of endodontic origin have a bacterial etiological agent. Thus, there is a continued interest in seeking more effective chemical substances that can replace the camphorated paramonochiorophenol or antibiotics as intracanal medicaments. Among the possible substances, ozone has some interesting biological characteristics: bactericidal action, debriding effect, angiogenesis stimulation capacity and high oxidizing power. The purpose of this study was to chemically evaluate the presence of ozone in sunflower, castor, olive and almond oil, as well as in propylene glycol and byproducts of ozonation, such as formaldehyde. These compounds were ozonized, inserted into empty and sterile vials, and analyzed by testing the reaction between ozone and indigo, for determining the presence of ozone, and subjected to the chromotropic acid test for determining the presence of formaldehyde. It was observed complete absence of ozone in all samples tested and presence of formaldehyde. The bactericidal and healing action of ozonized oils could be attributed to products formed by the ozonation of mineral oils, such as formaldehyde, not to the ozone itself. PMID:21519646

  15. Sterilization of Microorganisms by Ozone and Ultrasound

    NASA Astrophysics Data System (ADS)

    Krasnyj, V. V.; Klosovskij, A. V.; Panasko, T. A.; Shvets, O. M.; Semenova, O. T.; Taran, V. S.; Tereshin, V. I.

    2008-03-01

    The results of recent experimental methods of sterilization of microorganisms with the use of ozone and ultrasound are presented. The main aim was to optimize the process of sterilization in water solution taking into account the ozone concentration, the power of ultrasonic emitter and the temperature of water. In the present work, the ultrasonic cavitation with simultaneous ozone generation has been used. The high ozone concentration in water solution was achieved by two-barrier glow discharge generated at atmospheric pressure and a cooling thermo-electric module. Such a sterilizer consists of ozone generator in a shape of flat electrodes covered with dielectric material and a high-voltage pulsed power supply of 250 W. The sterilization camera was equipped with ultrasonic source operated at 100 W. The experiments on the inactivation of bacteria of the Bacillus Cereus type were carried out in the distilled water saturated by ozone. The ozone concentration in the aqueous solution was 10 mg/1, whereas the ozone concentration at the output of ozone generator was 30 mg/1. The complete inactivation of spores took 15 min. Selection of the temperature of water, the ozone concentrations and ultrasonic power allowed to determine the time necessary for destroying the row of microorganisms.

  16. Ozone inactivation of cell-associated viruses.

    PubMed Central

    Emerson, M A; Sproul, O J; Buck, C E

    1982-01-01

    The inactivation of HEp-2 cell-associated poliovirus (Sabin 1) and coxsackievirus A9 was investigated in three experimental systems, using ozone as a disinfectant. The cell-associated viral samples were adjusted to a turbidity of 5 nephelometric turbidity units. The cell-associated poliovirus and coxsackievirus samples demonstrated survival in a continuous-flow ozonation system at applied ozone dosages of 4.06 and 4.68 mg/liter, respectively, for 30 s. Unassociated viral controls were inactivated by the application of 0.081 mg of ozone per liter for 10 s. Ultrasonic treatment of cell-associated enteric viruses did not increase inactivation of the cell-associated viruses. The batch reactor with a declining ozone residual did not effect total inactivation of either cell-associated enteric virus. These cell-associated viruses were completely inactivated after exposure to ozone in a batch reactor using continuous ozonation. Inactivation of cell-associated poliovirus required a 2-min contact period with an applied ozone dosage of 6.82 mg/liter and a residual ozone concentration of 4.70 mg/liter, whereas the coxsackievirus was completely inactivated after a 5-min exposure to an applied ozone dosage of 4.81 mg/liter with an ozone residual of 2.18 mg/liter. These data indicate that viruses associated with cells or cell fragments are protected from inactivation by ozone concentrations that readily inactivate purified virus. The cell-associated viral samples used in this research contained particles that were 10 to 15 microns in size. Use of a filtration system before ozonation would remove these particles, thereby facilitating inactivation of any remaining viruses associated with cellular fragments. PMID:6280611

  17. CANOZE measurements of the Arctic ozone hole

    NASA Technical Reports Server (NTRS)

    Evans, W. F. J.; Kerr, J. B.; Fast, H.

    1988-01-01

    In CANOZE 1 (Canadian Ozone Experiment), a series of 20 ozone profile measurements were made in April, 1986 from Alert at 82.5 N. CANOZE is the Canadian program for study of the Arctic winter ozone layer. In CANOZE 2, ozone profile measurements were made at Saskatoon, Edmonton, Churchill and Resolute during February and March, 1987 with ECC ozonesondes. Ground based measurements of column ozone, nitrogen dioxide and hydrochloric acid were conducted at Saskatoon. Two STRATOPROBE balloon flights were conducted on February 26 and March 19, 1987. Two aerosol flights were conducted by the University of Wyoming. The overall results of this study will be reported and compared with the NOZE findings. The results from CANOZE 3 in 1988, are also discussed. In 1988, as part of CANOZE 3, STRATOPROBE balloon flights were conducted from Saskatchewan on January 27 and February 13. A new lightweight infrared instrument was developed and test flown. A science flight was successfully conducted from Alert (82.5 N) on March 9, 1988 when the vortex was close to Alert; a good measurement of the profile of nitric acid was obtained. Overall, the Arctic spring ozone layer exhibits many of the features of the Antarctic ozone phenomenon, although there is obviously not a hole present every year. The Arctic ozone field in March, 1986 demonstrated many similarities to the Antarctic ozone hole. The TOMS imagery showed a crater structure in the ozone field similar to the Antarctic crater in October. Depleted layers of ozone were found in the profiles around 15 km, very similar to those reported from McMurdo. Enhanced levels of nitric acid were measured in air which had earlier been in the vortex. The TOMS imagery for March 1987 did not show an ozone crater, but will be examined for an ozone crater in February and March, 1988, the target date for the CANOZE 3 project.

  18. Ozone depletion: Can global action rescue the deteriorating ozone layer

    SciTech Connect

    Cooper, M.H.

    1992-04-03

    Until recently, severe depletion of the Earth's protective ozone layer - which blocks harmful solar radiation - was thought to be confined to a [open quotes]hole[close quotes] over Antarctica. But in February NASA scientists raised new concerns when they reported that the 25-mile-wide layer apparently is thinning over the Northern Hemisphere and other populated areas. Findings to be released this month may even show that a second hole has opened over northern New England, Canada, northern Europe, Russia and China. Led by the US, once complacent governments are now scrambling to accelerate the elimination of chlorofluorocarbons (CFCs) and other chemicals that destroy ozone. Their response to this global threat could provide a model for international cooperation in combating similar environmental dangers.

  19. Risk-based maintenance modeling. Prioritization of maintenance importances and quantification of maintenance effectiveness

    SciTech Connect

    Vesely, W.E.; Rezos, J.T.

    1995-09-01

    This report describes methods for prioritizing the risk importances of maintenances using a Probabilistic Risk Assessment (PRA). Approaches then are described for quantifying their reliability and risk effects. Two different PRA importance measures, minimal cutset importances and risk reduction importances, were used to prioritize maintenances; the findings show that both give similar results if appropriate criteria are used. The justifications for the particular importance measures also are developed. The methods developed to quantify the reliability and risk effects of maintenance actions are extensions of the usual reliability models now used in PRAs. These extended models consider degraded states of the component, and quantify the benefits of maintenance in correcting degradations and preventing failures. The negative effects of maintenance, including downtimes, also are included. These models are specific types of Markov models. The data for these models can be obtained from plant maintenance logs and from the Nuclear Plant Reliability Data System (NPRDS). To explore the potential usefulness of these models, the authors analyzed a range of postulated values of input data. These models were used to examine maintenance effects on a components reliability and performance for various maintenance programs and component data. Maintenance schedules were analyzed to optimize the component`s availability. In specific cases, the effects of maintenance were found to be large.

  20. Insect maintenance and transmission.

    PubMed

    Kingdom, Heather

    2013-01-01

    Phytoplasmas are plant pathogens of huge economic importance due to responsibility for crop yield losses worldwide. Institutions around the world are trying to understand and control this yield loss at a time when food security is high on government agendas. In order to fully understand the mechanisms of phytoplasma infection and spread, more insect vector and phytoplasma colonies will need to be established for research worldwide. Rearing and study of these colonies is essential in the research and development of phytoplasma control measures. This chapter highlights general materials and methods for raising insect vector colonies and maintenance of phytoplasmas. Specific methods of rearing the maize leafhopper and maize bushy stunt phytoplasma and the aster leafhopper and aster yellows phytoplasma strain witches' broom are also included. PMID:22987405

  1. DCSP hardware maintenance system

    SciTech Connect

    Pazmino, M.

    1995-11-01

    This paper discusses the necessary changes to be implemented on the hardware side of the DCSP database. DCSP is currently tracking hardware maintenance costs in six separate databases. The goal is to develop a system that combines all data and works off a single database. Some of the tasks that will be discussed in this paper include adding the capability for report generation, creating a help package and preparing a users guide, testing the executable file, and populating the new database with data taken from the old database. A brief description of the basic process used in developing the system will also be discussed. Conclusions about the future of the database and the delivery of the final product are then addressed, based on research and the desired use of the system.

  2. Maintenance of certification.

    PubMed

    Rhodes, Robert S

    2007-02-01

    Maintenance of Certification (MOC) is the most recent stage in the evolution of specialty board certification. Driven by increasing concerns over the quality and safety of medical care, MOC represents a change in the frequency and the nature of the requirements of existing recertification. Under MOC, the every 10-year snapshot of professionalism, participation in continuing medical education, and medical expertise that are part of current recertification will become a more continuous process. MOC adds the assessment of practice performance to these measures and represents a philosophical change as well as a requirement change. The focus of these assessments is for improvement rather than judgment. The extent to which MOC succeeds will reflect surgeons' ability to improve the quality of care through voluntary efforts. PMID:17305290

  3. TCMS operations and maintenance philosophy

    NASA Technical Reports Server (NTRS)

    Buehler, David P.; Griffin, Rock E.

    1992-01-01

    The purpose is to describe the basic philosophies of operating and maintaining the Test, Control, and Monitor System (TCMS) equipment. TCMS is a complex and sophisticated checkout system. Operations and maintenance processes developed to support it will be based upon current experience, but will be focused on the specific needs of TCMS in support of Space Station Freedom Program (SSFP) and related activities. An overview of the operations and maintenance goals and philosophies are presented. The assumptions, roles and responsibilities, concepts and interfaces for operation, on-line maintenance, off-line support, and Operations and Maintenance (O&M) personnel training on all TCMS equipment located at KSC are described.

  4. Ozone, ozone production rates and NO observations on the outskirts of Quito, Ecuador

    NASA Astrophysics Data System (ADS)

    Cazorla, M.

    2014-12-01

    Air quality measurements of ambient ozone, ozone production rates and nitrogen oxides, in addition to baseline meterology observations, are being taken at a recently built roof-top facility on the campus of Universidad San Francisco de Quito, in Ecuador. The measurement site is located in Cumbayá, a densely populated valley adjacent to the city of Quito. Time series of ozone and NO are being obtained with commercial air quality monitors. Rush-hour peaks of NO, above 100 ppb, have been observed, while daytime ozone levels are low. In addition, ozone production rates are being measured with the Ecuadorian version of the MOPS, Measurement of Ozone Production Sensor, originally built at Penn State University in 2010. NO and ozone observations and test results of measured ozone production rates will be presented.

  5. Ozone Contamination in Aircraft Cabins: Appendix B: Overview papers. Ozone destruction techniques

    NASA Technical Reports Server (NTRS)

    Wilder, R.

    1979-01-01

    Ozone filter test program and ozone instrumentation are presented. Tables on the flight tests, samll scale lab tests, and full scale lab tests were reviewed. Design verification, flammability, vibration, accelerated contamination, life cycle, and cabin air quality are described.

  6. The 1990 Antarctica ozone hole as observed by TOMS. [Total Ozone Mapping Spectrometer

    NASA Technical Reports Server (NTRS)

    Newman, Paul; Stolarski, Richard; Schoeberl, Mark; Mcpeters, Richard; Krueger, Arlin

    1991-01-01

    The 1990 Antarctic ozone hole matched the record 1987 ozone hole in depth, duration, and area. During the formation phase of the hole (August), total ozone values were the lowest yet recorded. The decline rate approximately matched the record 1987 decline and reached a minimum of 125 Dobson Units on October 4, 1990. October total ozone averages were marginally higher that 1987. As during 1987, the 1990 total ozone values within the hole slowly and steadily increased during the mid-October through November period. The ozone hole breakup was the latest yet recorded (early December), with low ozone values persisting over the pole through December, setting a record low for December average polar ozone. Temperatures were near average during the early spring, but were below normal for the late spring. Temperatures in the early spring of 1990 were substantially warmer than those observed in the early spring of 1987.

  7. The 1990 Antarctic ozone hole as observed by TOMS. [Total Ozone Mapping Spectrometer

    SciTech Connect

    Newman, P.; Stolarski, R.; Schoeberl, M.; McPeters, R.; Krueger, A.

    1991-04-01

    The 1990 Antarctic ozone hole matched the record 1987 ozone hole in depth, duration, and area. During the formation phase of the hole (August), total ozone values were the lowest yet recorded. The decline rate approximately matched the record 1987 decline, and reached a minimum of 125 Dobson Units on October 4, 1990. October total ozone averages were marginally higher than 1987. As during 1987, the 1990 total ozone values within the hole slowly and steadily increased during the mid-October through November period. The ozone hole breakup was the latest yet recorded (early December), with low ozone values persisting over the pole through December, setting a record low for December average polar ozone. Temperatures were near average during the early spring, but were below normal for the late-spring. Temperatures in the early spring of 1990 were substantially warmer than those observed in the early spring of 1987.

  8. Ozone dynamics and snow-atmosphere exchanges during ozone depletion events at Barrow, Alaska

    NASA Astrophysics Data System (ADS)

    Helmig, Detlev; Boylan, Patrick; Johnson, Bryan; Oltmans, Sam; Fairall, Chris; Staebler, Ralf; Weinheimer, Andrew; Orlando, John; Knapp, David J.; Montzka, Denise D.; Flocke, Frank; Frieß, Udo; Sihler, Holger; Shepson, Paul B.

    2012-10-01

    The behavior of lower atmospheric ozone and ozone exchanges at the snow surface were studied using a suite of platforms during the Ocean-Atmosphere-Sea Ice-Snow (OASIS) Spring 2009 experiment at an inland, coastal site east of Barrow, Alaska. A major objective was to investigate if and how much chemistry at the snow surface at the site contributes to springtime ozone depletion events (ODEs). Between March 8 and April 16, seven ODEs, with atmospheric ozone dropping below 1.0 ppbv, were observed. The depth of the ozone-depleted layer was variable, extending from the surface to ˜200-800 m. ODEs most commonly occurred during low wind speed conditions with flow coming from the Arctic Ocean. Two high-sensitivity ozone chemiluminescence instruments were used to accurately define the remaining sub-ppbv ozone levels during ODEs. These measurements showed variable residual ODE ozone levels ranging between 0.010 and 0.100 ppbv. During the most extended ODE, when ozone remained below 1.0 ppbv for over 78 h, these measurements showed a modest ozone recovery or production in the early afternoon hours, resulting in increases in the ozone mixing ratio of 0.100 to 0.800 ppbv. The comparison between high-sensitivity ozone measurements and BrO measured by longpath differential absorption spectroscopy (DOAS) during ODEs indicated that at low ozone levels formation of BrO is controlled by the amount of available ozone. Measurements of ozone in air drawn from below the snow surface showed depleted ozone in the snowpack, with levels consistently remaining <6 ppbv independent of above-surface ambient air concentrations. The snowpack was always a sink of ozone. Ozone deposition velocities determined from ozone surface flux measurements by eddy covariance were on the order of 0.01 cm s-1, which is of similar magnitude as ozone uptake rates found over snow at other polar sites that are not subjected to ODEs. The results from these multiple platform measurements unequivocally show that snow

  9. Space shuttle maintenance program planning document

    NASA Technical Reports Server (NTRS)

    Brown, D. V.

    1972-01-01

    A means for developing a space shuttle maintenance program which will be acceptable to the development centers, the operators (KSC and AF), and the manufacturer is presented. The general organization and decision processes for determining the essential scheduled maintenance requirements for the space shuttle orbiter are outlined. The development of initial scheduled maintenance programs is discussed. The remaining maintenance, that is non-scheduled or non-routine maintenance, is directed by the findings of the scheduled maintenance program and the normal operation of the shuttle. The remaining maintenance consists of maintenance actions to correct discrepancies noted during scheduled maintenance tasks, nonscheduled maintenance, normal operation, or condition monitoring.

  10. Illinois Occupational Skill Standards: Industrial Maintenance General Maintenance Cluster.

    ERIC Educational Resources Information Center

    Illinois Occupational Skill Standards and Credentialing Council, Carbondale.

    These skill standards for the industrial maintenance general maintenance cluster are intended to be a guide to workforce preparation program providers in defining content for their programs and to employers to establish the skills and standards necessary for job acquisition. An introduction provides the Illinois perspective; Illinois Occupational…

  11. IMIS: Integrated Maintenance Information System. A maintenance information delivery concept

    NASA Technical Reports Server (NTRS)

    Vonholle, Joseph C.

    1987-01-01

    The Integrated Maintenance Information System (IMIS) will optimize the use of available manpower, enhance technical performance, improve training, and reduce the support equipment and documentation needed for deployment. It will serve as the technician's single, integrated source of all the technical information required to perform modern aircraft maintenance.

  12. Bioassaying for ozone with pollen systems

    SciTech Connect

    Feder, W.A.

    1981-01-01

    Sensitivity to ozone of pollen germinating in vitro is closely correlated with ozone sensitivity of the pollen parent. Ozone-sensitive and tolerant pollen populations have been identified in tobacco, petunia, and tomato cultivars. The rate of tube elongation can be reversibly slowed or stopped by exposure to low concentrations of ozone. The performance of selected pollen populations can then be used to bioassay ozone in ambient air by introducing the air sample into a growth chamber where ozone-sensitive pollen in growing. Year-round pollen producion can be achieved in the greenhouse. Harvested pollen can be tested, packaged, and transported to user facilities without loss of vigor. Pollen populations are inexpensive to produce, respond reliably, and are simple to use as a bioassay for air quality.

  13. Ozone damage detection in cantaloupe plants

    NASA Technical Reports Server (NTRS)

    Gausman, H. W.; Escobar, D. E.; Rodriguez, R. R.; Thomas, C. E.; Bowen, R. L.

    1978-01-01

    Ozone causes up to 90 percent of air pollution injury to vegetation in the United States; excess ozone affects plant growth and development and can cause undetected decrease in yields. Laboratory and field reflectance measurements showed that ozone-damaged cantaloupe (Cucumis melo L.) leaves had lower water contents and higher reflectance than did nondamaged leaves. Cantaloupe plants which were lightly, severely, and very severely ozone-damaged were distinguishable from nondamaged plants by reflectance measurements in the 1.35- to 2.5 micron near-infrared water absorption waveband. Ozone-damaged leaf areas were detected photographically 16 h before the damage was visible. Sensors are available for use with aircraft and spacecraft that possibly could be used routinely to detect ozone-damaged crops.

  14. Stratospheric Ozone: Transport, Photochemical Production and Loss

    NASA Technical Reports Server (NTRS)

    Douglass, A. R.; Kawa, S. R.; Jackman, C. H.

    2003-01-01

    Observations from various satellite instruments (e.g., Total Ozone Mapping Spectrometer (TOMS), Halogen Occultation Experiment (HALOE), Microwave Limb Sounder (MLS)) specify the latitude and seasonal variations of total ozone and ozone as a function of altitude. These seasonal variations change with latitude and altitude partly due to seasonal variation in transport and temperature, partly due to differences in the balance between photochemical production and loss processes, and partly due to differences in the relative importance of the various ozone loss processes. Comparisons of modeled seasonal ozone behavior with observations test the following: the seasonal dependence of dynamical processes where these dominate the ozone tendency; the seasonal dependence of photochemical processes in the upper stratosphere; and the seasonal change in the balance between photochemical and dynamical processes.

  15. Intercomparison of ozone measurements over Antarctica

    NASA Technical Reports Server (NTRS)

    Margitan, J. J.; Farmer, C. B.; Toon, G. C.; Brothers, G. A.; Browell, E. V.; Gregory, G. L.; Hypes, W.; Larsen, J. C.; Mccormick, M. P.; Krueger, A. J.

    1989-01-01

    Measurements of the abundances of ozone over Antarctica in August and September 1987 obtained during the Airborne Antarctic Ozone Experiment are intercompared. These measurements of ozone concentrations and total column abundance were obtained by three satellite instruments, two IR and one UV column-measuring instruments aboard the DC-8, one in situ DC-8, and two in situ ER-2 instruments, an upward looking lidar aboard the DC-8, and ozone sondes from four sites in Antarctica. This paper presents a summary of the ozone data, using the data and accuracies given by the individual investigators in the individual papers in this issue, without any attempt to critically review or evaluate the data. In general, very good agreement (within about 10-20 percent, limited by natural variability) among the various techniques was found, with no systematic biases detected. These observations confirm the low ozone amounts reported in the Antarctic stratosphere.

  16. Changing ozone: Evidence for a perturbed atmosphere

    SciTech Connect

    Penkett, S.A. )

    1991-04-01

    There is much legitimate concern about the dramatic loss of ozone that is observed in the stratosphere over Antarctica in the Austral spring. There should be even more concern about the increasing losses of ozone observed recently in polar and midlatitude regions of the stratosphere in the northern hemisphere. In addition to the ozone losses occurring in the stratosphere, there is now compelling evidence that the ozone concentration in large parts of the northern hemisphere troposphere is increasing steadily. This is almost certainly caused by emissions of hydrocarbons, carbon monoxide, and nitrogen oxides from combustion processes of many kinds, but principally transport and biomass burning. It is hoped that these extensive studies of ozone in the background troposphere materialize and allow us to develop a clear quantitative link between emissions of pollutants and their effects. The changes already observed in the ozone concentrations throughout the atmosphere clearly demonstrate the capacity for human activity to influence the fundamental workings of the atmosphere.

  17. Ozone decomposition in aqueous acetate solutions

    SciTech Connect

    Sehested, K.; Holcman, J.; Bjergbakke, E.; Hart, E.J.

    1987-01-01

    The acetate radical ion reacts with ozone with a rate constant of k = (1.5 +/- 0.5) x 10Z dmT mol s . The products from this reaction are CO2, HCHO, and O2 . By subsequent reaction of the peroxy radical with ozone the acetate radical ion is regenerated through the OH radical. A chain decomposition of ozone takes place. It terminates when the acetate radical ion reacts with oxygen forming the unreactive peroxy acetate radical. The chain is rather short as oxygen is developed, as a result of the ozone consumption. The inhibiting effect of acetate on the ozone decay is rationalized by OH scavenging by acetate and successive reaction of the acetate radical ion with oxygen. Some products from the bimolecular disappearance of the peroxy acetate radicals, however, react further with ozone, reducing the effectiveness of the stabilization.

  18. Laboratory studies of heavy ozone

    NASA Technical Reports Server (NTRS)

    Morton, J.; Barnes, J.; Schueler, B.; Mauersberger, K.

    1990-01-01

    Dissociation of ozone in the Chappuis bands has been used as an O atom source to study isotope effects occurring in the O(3P) + O2(3 Sigma g) recombination reaction. The ozone produced was found to be enriched in both of its heavy isotopes. The pressure dependence (5-1000 torr) and temperature dependence (127-360 K) of this isotope effect have been investigated. The enrichment is approximately constant from 5 torr to 100 torr and decreases at higher pressures. It increases with temperature, with O3-50 showing a slightly faster rate of increase than O3-45. The results of this experiment have clearly isolated the source of the isotope effect to the gas phase O(3P) + O2(3 Sigma g) recombination reaction.

  19. Discharge cell for ozone generator

    SciTech Connect

    Nakatsuka, Suguru

    2000-01-01

    A discharge cell for use in an ozone generator is provided which can suppress a time-related reduction in ozone concentration without adding a catalytic gas such as nitrogen gas to oxygen gas as a raw material gas. The discharge cell includes a pair of electrodes disposed in an opposed spaced relation with a discharge space therebetween, and a dielectric layer of a three-layer structure consisting of three ceramic dielectric layers successively stacked on at least one of the electrodes, wherein a first dielectric layer of the dielectric layer contacting the one electrode contains no titanium dioxide, wherein a second dielectric layer of the dielectric layer exposed to the discharge space contains titanium dioxide in a metal element ratio of not lower than 10 wt %.

  20. 40 CFR 52.2332 - Control Strategy: Ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...: Ozone. Determinations—EPA is determining that, as of July 18, 1995, the Salt Lake and Davis Counties... the ozone NAAQS is monitored in the Salt Lake and Davis Counties ozone nonattainment area,...

  1. Report of the International Ozone Trends Panel 1988, volume 1

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Chapters on the following topics are presented: spacecraft instrument calibration and stability; information content of ozone retrieval algorithms; trends in total column ozone measurements; and trends in ozone profile measurement.

  2. CONTROL OF OZONE DISINFECTION BY EXHAUST GAS MONITORING

    EPA Science Inventory

    In this paper it was demonstrated empirically that disinfection with ozone can be controlled by monitoring the exhaust gas ozone concentration exiting the contactor. This method is more reliable than measuring dissolved ozone because of the inherent difficulties and inadequacies ...

  3. Ozone in the Atmosphere: I. The Upper Atmosphere.

    ERIC Educational Resources Information Center

    Phillips, Paul S.

    1990-01-01

    Research concerning the role of stratospheric ozone and the effect of chlorofluorocarbons on stratospheric ozone are discussed. The consequences of global ozone depletion are projected. The Montreal Protocol is reviewed. (CW)

  4. SCISAT to study ozone depletion

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    The Canadian Space Agency's SCISAT satellite began its mission to study the depletion of the ozone layer, following a successful launch on 12 August.The goal for the atmospheric chemistry experiment, which is SCISAT's mission, is to improve the scientific understanding of the complex chemical changes occurring in the upper atmosphere, particularly in the far north, according to Canada's Minister of Industry, Allan Rock.

  5. Ozone bleaching of recycled paper

    SciTech Connect

    Muguet, M.; Kogan, J. )

    1993-11-01

    Chlorinated bleaching chemicals, notably chlorine and hypochlorite, are still being used to bleach deinked, woodfree pulps. Increasing environmental concern about the use of these chemicals--coupled with the industry's efforts to increase the use of recycled fibers--highlight the need to develop better techniques for producing high-quality deinked pulp. Results presented in this report suggest that deinked fibers can be treated with ozone followed by a peroxide bleaching stage to produce a high-quality pulp.

  6. Tropospheric Ozone and Biomass Burning

    NASA Technical Reports Server (NTRS)

    Chandra, Sushil; Ziemke, J. R.; Bhartia, P. K.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    This paper studies the significance of pyrogenic (e.g., biomass burning) emissions in the production of tropospheric ozone in the tropics associated with the forest and savanna fires in the African, South American, and Indonesian regions. Using aerosol index (Al) and tropospheric column ozone (TCO) time series from 1979 to 2000 derived from the Nimbus-7 and Earth Probe TOMS measurements, our study shows significant differences in the seasonal and spatial characteristics of pyrogenic emissions north and south of the equator in the African region and Brazil in South America. In general, they are not related to the seasonal and spatial characteristics of tropospheric ozone in these regions. In the Indonesian region, the most significant increase in TCO occurred during September and October 1997, following large-scale forest and savanna fires associated with the El Nino-induced dry season. However, the increase in TCO extended over most of the western Pacific well outside the burning region and was accompanied by a decrease in the eastern Pacific resembling a west-to-east dipole about the date-line. The net increase in TCO integrated over the tropical region between 15 deg N and 15 deg S was about 6-8 Tg (1 Tg = 10(exp 12) gm) over the mean climatological value of about 72 Tg. This increase is well within the range of interannual variability of TCO in the tropical region and does not necessarily suggest a photochemical source related to biomass burning. The interannual variability in TCO appears to be out of phase with the interannual variability of stratospheric column ozone (SCO). These variabilities seem to be manifestations of solar cycle and quasibiennial oscillations.

  7. Ozone Uncertainties Study Algorithm (OUSA)

    NASA Technical Reports Server (NTRS)

    Bahethi, O. P.

    1982-01-01

    An algorithm to carry out sensitivities, uncertainties and overall imprecision studies to a set of input parameters for a one dimensional steady ozone photochemistry model is described. This algorithm can be used to evaluate steady state perturbations due to point source or distributed ejection of H2O, CLX, and NOx, besides, varying the incident solar flux. This algorithm is operational on IBM OS/360-91 computer at NASA/Goddard Space Flight Center's Science and Applications Computer Center (SACC).

  8. Ozone Uncertainties Study Algorithm (OUSA)

    NASA Astrophysics Data System (ADS)

    Bahethi, O. P.

    An algorithm to carry out sensitivities, uncertainties and overall imprecision studies to a set of input parameters for a one dimensional steady ozone photochemistry model is described. This algorithm can be used to evaluate steady state perturbations due to point source or distributed ejection of H2O, CLX, and NOx, besides, varying the incident solar flux. This algorithm is operational on IBM OS/360-91 computer at NASA/Goddard Space Flight Center's Science and Applications Computer Center (SACC).

  9. Residual ozone determination by flow injection analysis

    SciTech Connect

    Straka, M.R.; Pacey, G.E.; Gordon, G.

    1984-09-01

    It has been proposed that ozone be used to replace free chlorine for the disinfection of drinking water and waste water. For the use of ozone in this capacity, it would be necessary to have a fast accurate and precise method to analyze for the presence of residuals. An automated method for ozone determination based on the indigo reagent method is presented. This method is based on the advantages of flow injection analysis (FIA) techniques. 19 references, 3 tables, 2 figures.

  10. 21 CFR 173.368 - Ozone.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ozone. 173.368 Section 173.368 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) SECONDARY DIRECT FOOD ADDITIVES PERMITTED IN FOOD FOR HUMAN CONSUMPTION Specific Usage Additives § 173.368 Ozone. Ozone (CAS Reg. No. 10028-15-6) may be safely used in...

  11. Ozone pollution and ozone biomonitoring in European cities Part II. Ozone-induced plant injury and its relationship with descriptors of ozone pollution

    NASA Astrophysics Data System (ADS)

    Klumpp, Andreas; Ansel, Wolfgang; Klumpp, Gabriele; Vergne, Phillippe; Sifakis, Nicolas; Sanz, María José; Rasmussen, Stine; Ro-Poulsen, Helge; Ribas, Àngela; Peñuelas, Josep; Kambezidis, Harry; He, Shang; Garrec, Jean Pierre; Calatayud, Vicent

    Within the scope of a biomonitoring study conducted in twelve urban agglomerations in eight European countries, the ozone-sensitive bioindicator plant Nicotiana tabacum cv. Bel-W3 was employed in order to assess the occurrence of phytotoxic ozone effects at urban, suburban, rural and traffic-exposed sites. The tobacco plants were exposed to ambient air for biweekly periods at up to 100 biomonitoring sites from 2000 to 2002. Special emphasis was placed upon methodological standardisation of plant cultivation, field exposure and injury assessment. Ozone-induced leaf injury showed a clearly increasing gradient from northern and northwestern Europe to central and southern European locations. The strongest ozone impact occurred at the exposure sites in Lyon and Barcelona, while in Edinburgh, Sheffield, Copenhagen and Düsseldorf only weak to moderate ozone effects were registered. Between-site differences within local networks were relatively small, but seasonal and inter-annual differences were strong due to the variability of meteorological conditions and related ozone concentrations. The 2001 data revealed a significant relationship between foliar injury degree and various descriptors of ozone pollution such as mean value, AOT20 and AOT40. Examining individual sites of the local monitoring networks separately, however, yielded noticeable differences. Some sites showed no association between ozone pollution and ozone-induced effects, whereas others featured almost linear relationships. This is because the actual ozone flux into the leaf, which is modified by various environmental factors, rather than ambient ozone concentration determines the effects on plants. The advantage of sensitive bioindicators like tobacco Bel-W3 is that the impact of the effectively absorbed ozone dose can directly be measured.

  12. Polar stratospheric clouds and ozone depletion

    SciTech Connect

    Toon, O.B. ); Turco, R.P. )

    1991-06-01

    During the Antarctic winter, strange and often invisible clouds form in the stratosphere over the pole. These clouds of ice and frozen nitric acid play a crucial role in the chemical cycle responsible for the recent appearance of the annual ozone hole. Their chemistry removes compounds that would normally trap ozone-destroying free chlorine produced by the breakdown of CFCs. The paper describes these clouds, their formation, and the mechanisms by which these clouds help chlorine destroy ozone.

  13. National Ozone Expedition: Microwave radiometer measurements

    SciTech Connect

    de Zafra, R.; Solomon, P. )

    1987-09-01

    To measure vertical profiles of chlorine monoxide, nitrous oxide, hydrogen cyanide, and ozone, the authors will use a millimeter-wave spectrometer. Of these measurements the levels of chlorine monoxide should help to describe potential causes of the cause of the ozone hole. If the ozone depletion is chlorine related, abundances of chlorine monoxide, taken approximately 12 miles (20 kilometers) above the Earth's surface, could be 100 times greater than normal.

  14. Ozone climatology series. Volume 1: Atlas of total ozone, April 1970 - December 1976

    NASA Technical Reports Server (NTRS)

    Heath, D. F.; Fleig, A. J.; Miller, A. J.; Rogers, T. G.; Nagatani, R. M.; Bowman, H. D., II; Kaveeshwar, V. G.; Klenk, K. F.; Bhartia, P. K.; Lee, K. D.

    1982-01-01

    Contours and gridded values are given for seven years of monthly mean total ozone data derived from observations with the Backscattered Ultraviolet instrument on Nimbus-4 for the Northern and Southern Hemispheres. The instrument, algorithm, uncertainties in derived ozone and systematic changes in the bias with respect to the international groundbased ozone network of Dobson instruments, are discussed.

  15. Uncertainties in total ozone amounts inferred from zenith sky observations: Implications for ozone trend analyses

    SciTech Connect

    Stamnes, K.; Pegau, S. ); Frederick, J. )

    1990-09-20

    A preliminary study involving radiative transfer calculations has been conducted to simulate ozone inference fro Dobson spectrophotometer observations. By using a comprehensive radiative transfer algorithm, a model atmosphere, and a suitable set of ozone absorption cross sections, the authors have simulated, for a specific ozone profile and an ozone amount of about 350 Dobson units, the effects of cloud optical depth, cloud altitude, vertical distribution of ozone, temperature profile, and surface albedo on the total amount of ozone inferred byd the Dobson procedure from zenith sky observations. These simulations indicate that significant uncertainties may arise in determining ozone amounts from measurements of zenith sky intensity. The implications of these uncertainties for ozone trend analyses are described, showing, for example, that an appreciable error could arise in deduced ozone trend should tropospheric ozone double in the foreseeable future but not be taken into account in total ozone data processing. The radiative transfer algorithm may, furthermore, be employed to construct charts for use at each Dobson instrument site in processing zenith sky ozone observations. The theoretically derived charts would, however, need on-site correcting to account for instrumental effects. Construction and use of synthetic correction tables for any particular station may alleviate difficulties encountered in the creation of empirical correction tables, since it avoids problems related to (1) time lapse between measurements and (2) diffuse radiation from forward scattering in clouds influencing the direct Sun measurements.

  16. Efficient ozone generator for ozone layer enrichment from high altitude balloon

    NASA Technical Reports Server (NTRS)

    Filiouguine, Igor V.; Kostiouchenko, Sergey V.; Koudriavtsev, Nikolay N.; Starikovskaya, Svetlana M.

    1994-01-01

    The possibilities of ozone production at low gas pressures by nanosecond high voltage discharge has been investigated. The measurements of ozone synthesis in N2-O2 mixtures have been performed. The explanation of experimental results is suggested. The possible ways of ozone yield growth are analyzed.

  17. OZONE MONITORING, MAPPING, AND PUBLIC OUTREACH: DELIVERING REAL-TIME OZONE INFORMATION TO YOUR COMMUNITY

    EPA Science Inventory

    The U.S. EPA had developed a handbook to help state and local government officials implement ozone monitoring, mapping, and outreach programs. The handbook, called Ozone Monitoring, Mapping, and Public Outreach: Delivering Real-Time Ozone Information to Your Community, provides ...

  18. Ozone mapper survives Soviet coup

    SciTech Connect

    Not Available

    1991-09-06

    NASA's latest satellite-borne monitor of the Earth's protective ozone layer went operational a little earlier than planned last month. The unprecedented launch - on a Soviet weather satellite - of the Total Ozone Mapping Spectrometer (TOMS) took place on 15 August. Three days later so did the coup that has shaken the Soviet Union to its foundations. So, instead of waiting weeks to let the instrument adjust to space conditions, NASA engineers, who were in Moscow to monitor the launch, turned TOMS on before going home - just 5 days post-launch. No problems resulted, and the orbiting instrument, which for the first 2 months of its 2-year mission will track the formation of this year's Antarctic ozone hole, is now returning data to both US and Soviet ground stations. The launch of a new TOMS was an urgent imperative for US atmospheric researchers. The old one, now approaching its 13th year in orbit on the NASA satellite Nimbus-7, was showing its age and threatened to quit working. Because of the tight launch schedules following the Challenger disaster, NASA sought outside help to get TOMS off the ground. The Soviet Union turned out to be the best partner: it is developing a new network of Meteor meteorology satellites, and the 1987 US/USSR space cooperation agreement allowed the Soviet Cyclone booster to become the Americans' savior.

  19. Ozone observations in the Northeast

    NASA Astrophysics Data System (ADS)

    Austin, S. A.; Johnson, L. P.; Johnson, R. O.; Skeete, D.; Culpepper, J.; Cumberbatch, S.; Deceus, G.; Guerrero, J.; Reid, J.; Smith, P.; Rios, J.

    2008-12-01

    This presentation describes the results of NASA and NSF-funded investigations of tropospheric and stratospheric ozone in upstate New York, northern Vermont andthe NWS/NYC sounding facility in Brookhaven, New York conducted completely by undergraduate and high school students in the summer of 2008. The poster describes the lab and flight preparation for the ozone observations as well as modifications and enhancements for data retrieval including a reduced cost technique for using GPS receivers. The poster also describe the profiles obtained over the summer, and compares and contrasts the observed ozone in the troposphere in varying atmospheric conditions together with the forward and backward trajectories to analyze the flow at different atmospheric levels. The student authors also share insights on how the project has motivated and stimulated interest in atmospheric-science related careers particularly among minority students from urban areas. This summer research opportunity was supported by an NSF Geoscience Diversity Award (NSF GEO-0703585), the NASA New York State Space Grant Consortium and the NASA New York City Research Initiative.

  20. Ozone therapy: A clinical review

    PubMed Central

    Elvis, A. M.; Ekta, J. S.

    2011-01-01

    Ozone (O3) gas discovered in the mid-nineteenth century is a molecule consisting of three atoms of oxygen in a dynamically unstable structure due to the presence of mesomeric states. Although O3 has dangerous effects, yet researchers believe it has many therapeutic effects. Ozone therapy has been utilized and heavily studied for more than a century. Its effects are proven, consistent, safe and with minimal and preventable side effects. Medical O3 is used to disinfect and treat disease. Mechanism of actions is by inactivation of bacteria, viruses, fungi, yeast and protozoa, stimulation of oxygen metabolism, activation of the immune system. Medication forms in a gaseous state are somewhat unusual, and it is for this reason that special application techniques have had to be developed for the safe use of O3. In local applications as in the treatment of external wounds, its application in the form of a transcutaneous O3 gas bath has established itself as being the most practical and useful method, for example at low (sub-atmospheric) pressure in a closed system guaranteeing no escape of O3 into the surrounding air. Ozonized water, whose use is particularly known in dental medicine, is optimally applied as a spray or compress. Diseases treated are infected wounds, circulatory disorders, geriatric conditions, macular degeneration, viral diseases, rheumatism/arthritis, cancer, SARS and AIDS. PMID:22470237

  1. Ozone therapy: A clinical review.

    PubMed

    Elvis, A M; Ekta, J S

    2011-01-01

    Ozone (O(3)) gas discovered in the mid-nineteenth century is a molecule consisting of three atoms of oxygen in a dynamically unstable structure due to the presence of mesomeric states. Although O(3) has dangerous effects, yet researchers believe it has many therapeutic effects. Ozone therapy has been utilized and heavily studied for more than a century. Its effects are proven, consistent, safe and with minimal and preventable side effects. Medical O(3) is used to disinfect and treat disease. Mechanism of actions is by inactivation of bacteria, viruses, fungi, yeast and protozoa, stimulation of oxygen metabolism, activation of the immune system. Medication forms in a gaseous state are somewhat unusual, and it is for this reason that special application techniques have had to be developed for the safe use of O(3). In local applications as in the treatment of external wounds, its application in the form of a transcutaneous O(3) gas bath has established itself as being the most practical and useful method, for example at low (sub-atmospheric) pressure in a closed system guaranteeing no escape of O(3) into the surrounding air. Ozonized water, whose use is particularly known in dental medicine, is optimally applied as a spray or compress. Diseases treated are infected wounds, circulatory disorders, geriatric conditions, macular degeneration, viral diseases, rheumatism/arthritis, cancer, SARS and AIDS. PMID:22470237

  2. Y-12 Plant Stratospheric Ozone Protection plan

    SciTech Connect

    1995-09-01

    The Y-12 Plant staff is required by Lockheed Martin Energy Systems (Energy Systems) (formerly Martin Marietta Energy Systems) standard ESS-EP-129 to develop and implement a Stratospheric Ozone Protection Program which will minimize emissions of ozone-depleting substances to the environment and maximize the use of ozone-safe alternatives in order to comply with Title VI of the 1990 Clean Air Act (CAA) Amendments and the implementing regulations promulgated by the Environmental Protection Agency (EPA). This plan describes the requirements, initiatives, and accomplishments of the Y-12 Plant Stratospheric Ozone Protection Program.

  3. Monthly mean distribution of ozone and temperature

    NASA Technical Reports Server (NTRS)

    Labitzke, K.; Angell, J. K.; Barnett, J. J.; Bowman, P.; Corney, M.; Keating, G. M.; Krueger, A. J.; Miller, A. J.; Nagatani, R. M.

    1985-01-01

    Global monthly mean charts for both hemispheres are given for four mid-season months, and for the pressure levels 30, 10, 1, and 0.1 mbar for temperature and 0.4 mbar for ozone. Charts of total ozone are provided separately. This set of charts shows clearly the very close coupling between the temperature and ozone distributions and demonstrates the influence of the large-scale planetary waves which give rise to very large longitudinal variations. The regular and interannual variability of temperature and ozone are discussed.

  4. Mesospheric ozone measurements by SAGE II

    NASA Astrophysics Data System (ADS)

    Chu, D. A.; Cunnold, D. M.

    1994-04-01

    SAGE II observations of ozone at sunrise and sunset (solar zenith angle = 90 deg) at approximately the same tropical latitude and on the same day exhibit larger concentrations at sunrise than at sunset between 55 and 65 km. Because of the rapid conversion between atomic oxygen and ozone, the onion-peeling scheme used in SAGE II retrievals, which is based on an assumption of constant ozone, is invalid. A one-dimensional photochemical model is used to simulate the diurnal variation of ozone particularly within the solar zenith angle of 80 deg - 100 deg. This model indicates that the retrieved SAGE II sunrise and sunset ozone values are both overestimated. The Chapman reactions produce an adequate simulation of the ozone sunrise/sunset ratio only below 60 km, while above 60 km this ratio is highly affected by the odd oxygen loss due to odd hydrogen reactions, particularly OH. The SAGE II ozone measurements are in excellent agreement with model results to which an onion peeling procedure is applied. The SAGE II ozone observations provide information on the mesospheric chemistry not only through the ozone profile averages but also from the sunrise/sunset ratio.

  5. Mesospheric ozone measurements by SAGE II

    NASA Technical Reports Server (NTRS)

    Chu, D. A.; Cunnold, D. M.

    1994-01-01

    SAGE II observations of ozone at sunrise and sunset (solar zenith angle = 90 deg) at approximately the same tropical latitude and on the same day exhibit larger concentrations at sunrise than at sunset between 55 and 65 km. Because of the rapid conversion between atomic oxygen and ozone, the onion-peeling scheme used in SAGE II retrievals, which is based on an assumption of constant ozone, is invalid. A one-dimensional photochemical model is used to simulate the diurnal variation of ozone particularly within the solar zenith angle of 80 deg - 100 deg. This model indicates that the retrieved SAGE II sunrise and sunset ozone values are both overestimated. The Chapman reactions produce an adequate simulation of the ozone sunrise/sunset ratio only below 60 km, while above 60 km this ratio is highly affected by the odd oxygen loss due to odd hydrogen reactions, particularly OH. The SAGE II ozone measurements are in excellent agreement with model results to which an onion peeling procedure is applied. The SAGE II ozone observations provide information on the mesospheric chemistry not only through the ozone profile averages but also from the sunrise/sunset ratio.

  6. The new ozone monitor. Final report

    SciTech Connect

    Karlson, E.L.

    1994-09-20

    This report describes the development of an invention for measuring the concentration of ozone by measuring the heat evolved when the ozone is catalyzed and converted back to oxygen. This ozone monitor evolved through a number of prototype as described in the final report. The final instrument is accurate, reliable and can be installed as a part of a control system. This instrument can be built and calibrated for any necessary specific ozone concentration range. This instrument uses inexpensive parts and would be simple to maintain. the manufacturing cost is less than any equally reliable and accurate ozone monitor presently available. The advantage this system has is that the ozone is directly measured as the temperature of the catalyst. It does not need UV lamps (which continually degrade in use and have a variable life) or use any chemistry where a material is continuously used up. This new ozone monitor directly measures the heat that is generated from the ozone as it converts back into oxygen as the gas mixture flows through the catalyst. The catalyst has theocratically an infinite life. It can clog if the system it is installed in, is dusty. But in systems that produce ozone, it is important that the gas is clean. Under normal clean gas conditions this instrument will give long term service free monitoring.

  7. Correlation between cosmic rays and ozone depletion.

    PubMed

    Lu, Q-B

    2009-03-20

    This Letter reports reliable satellite data in the period of 1980-2007 covering two full 11-yr cosmic ray (CR) cycles, clearly showing the correlation between CRs and ozone depletion, especially the polar ozone loss (hole) over Antarctica. The results provide strong evidence of the physical mechanism that the CR-driven electron-induced reaction of halogenated molecules plays the dominant role in causing the ozone hole. Moreover, this mechanism predicts one of the severest ozone losses in 2008-2009 and probably another large hole around 2019-2020, according to the 11-yr CR cycle. PMID:19392251

  8. Long-term ozone monitoring from space

    NASA Astrophysics Data System (ADS)

    Ahmad, S.; Johnson, J.; Serafino, G.; McPeters, R.

    Global monitoring of ozone is important since ozone shields the biosphere from the harmful effects of solar radiation by absorbing the ultraviolet radiation below 320 nanometers (UV-B wavelength regions). By absorbing UV, visible, and infrared radiation, ozone also heats the stratosphere and affects the circulation of air masses and dynamics of the upper atmosphere. Ozone also plays an important role in the chemical cycles of the other trace gases. In the last two decades a number of sensors have been flown on satellites to monitor ozone from space. Daily global ozone maps of total column ozone were obtained from the Total Ozone Mapping Spectrometer (TOMS) instruments flown on the Nimbus-7, Meteor-3, Advanced Earth Observing Satellite (ADEOS) and Earth Probe (EP) satellites, and from the Global Ozone Monitoring experiment (GOME) onboard the second European Remote Sensing Satellite (ERS-2). The high quality measurements of the first TOMS instrument (flown on Nimbus-7 in 1978) played an instrumental role in the detection of a small but steady ozone decline since the early 1980s. This has led to investigation of the cause of ozone depletion in an effort to quantify how much of this could be attributed to human made processes as opposed to natural processes. The significance of this issue was underscored by the signing of the Montreal Protocol in 1987 restricting the production of ozone destroying chemicals. Furthermore, in September 1991, the Upper Atmosphere Research Satellite (UARS) was launched containing a comprehensive suite of instruments designed to collectively determine the impact of chemical, dynamic and energy input processes on ozone creation and destruction. The continuity of ozone, other trace species, and solar UV measurements will be provided with the launch of the Aura spacecraft in early 2004. Standard ozone products from a series of TOMS missions, UARS sensors, Nimbus-4 Backscatter Ultraviolet Spectrometer (BUV), and Nimbus-7 Solar Backscatter

  9. Long-term Ozone monitoring from space

    NASA Astrophysics Data System (ADS)

    Ahmad, S.; Johnson, J.; Serafino, G.; McPeters, R.

    Global monitoring of ozone is important since ozone shields the biosphere from the harmful effects of solar radiation by absorbing the ultraviolet radiation below 320 nanometers (UV-B wavelength regions). By absorbing UV, visible, and infrared radiation, ozone also heats the stratosphere and affects the circulation of air masses and dynamics of the upper atmosphere. Ozone also plays an important role in the chemical cycles of the other trace gases. In the last two decades a number of sensors have been flown on satellites to monitor ozone from space. Daily global ozone maps of total column ozone were obtained from the Total Ozone Mapping Spectrometer (TOMS) instruments flown on the Nimbus-7, Meteor-3, Advanced Earth Observing Satellite (ADEOS) and Earth Probe (EP) satellites, and from the Global Ozone Monitoring experiment (GOME) onboard the second European Remote Sensing Satellite (ERS-2). The high quality measurements of the first TOMS instrument (flown on Nimbus-7 in 1978) played an instrumental role in the detection of a small but steady ozone decline since the early 1980s. This has led to investigation of the cause of ozone depletion in an effort to quantify how much of this could be attributed to human made processes as opposed to natural processes. The significance of this issue was underscored by the signing of the Montreal Protocol in 1987 restricting the production of ozone destroying chemicals. Furthermore, in September 1991, the Upper Atmosphere Research Satellite (UARS) was launched containing a comprehensive suite of instruments designed to collectively determine the impact of chemical, dynamic and energy input processes on ozone creation and destruction. The continuity of ozone, other trace species, and solar UV measurements will be provided with the launch of the Aura spacecraft in early 2004. Standard ozone products from a series of TOMS missions, UARS sensors, Nimbus-4 Backscatter Ultraviolet Spectrometer (BUV), and Nimbus-7 Solar Backscatter

  10. Treatment of soft drink process wastewater by ozonation, ozonation-H₂O₂ and ozonation-coagulation processes.

    PubMed

    García-Morales, M A; Roa-Morales, G; Barrera-Díaz, C; Balderas-Hernández, P

    2012-01-01

    In this research, we studied the treatment of wastewater from the soft drink process using oxidation with ozone. A scheme composed of sequential ozonation-peroxide, ozonation-coagulation and coagulation-ozonation treatments to reduce the organic matter from the soft drink process was also used. The samples were taken from the conventional activated sludge treatment of the soft drink process, and the experiments using chemical oxidation with ozone were performed in a laboratory using a reactor through a porous plate glass diffuser with air as a feedstock for the generation of ozone. Once the sample was ozonated, the treatments were evaluated by considering the contact time, leading to greater efficiency in removing colour, turbidity and chemical oxygen demand (COD). The effect of ozonation and coagulant coupled with treatment efficiency was assessed under optimal conditions, and substantial colour and turbidity removal were found (90.52% and 93.33%, respectively). This was accompanied by a 16.78% reduction in COD (initial COD was 3410 mg/L). The absorbance spectra of the oxidised products were compared using UV-VIS spectroscopy to indicate the level of oxidation of the wastewater. We also determined the kinetics of decolouration and the removal of turbidity with the best treatment. The same treatment was applied to the sample taken from the final effluent of the activated sludge system, and a COD removal efficiency of 100% during the first minute of the reaction with ozone was achieved. As a general conclusion, we believe that the coagulant polyaluminum chloride - ozone (PAC- ozone) treatment of wastewater from the manufacturing of soft drinks is the most efficient for removing turbidity and colour and represents an advantageous option to remove these contaminants because their removal was performed in minutes compared to the duration of traditional physical, chemical and biological processes that require hours or days. PMID:22217079

  11. Cognitive Load and Maintenance Rehearsal.

    ERIC Educational Resources Information Center

    Naveh-Benjamin, Moshe; and Jonides, John

    1984-01-01

    Studies the much-debated issue of the role of rote, repetitive rehearsal (maintenance rehearsal) on the establishment of memory traces that outlast the rehearsal process itself. Results show that there is an effect of maintenance rehearsal on long-term recognition performance and that this effect depends on the mental resources devoted to the…

  12. Landscaping With Maintenance in Mind.

    ERIC Educational Resources Information Center

    Sorensen, Randy

    2000-01-01

    Examines school ground landscape design that enhances attractive of the school and provides for easier maintenance. Landscape design issues discussed include choice of grass, trees, and shrubs; irrigation; and safety and access. Other considerations for lessening maintenance problems for facility managers are also highlighted. (GR)

  13. Automotive Engine Maintenance and Repair.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide students with an understanding of automotive engine maintenance and repair. The course contains six study units covering automotive engine maintenance and repair; design classification; engine malfunction, diagnosis, and repair; engine disassembly; engine…

  14. Chemistry and Dynamics of the Unusual 2015 Antarctic Ozone Hole

    NASA Astrophysics Data System (ADS)

    Braathen, Geir O.

    2016-04-01

    The Global Atmosphere Watch of the World Meteorological Organization includes several stations in Antarctica that keep a close eye on the ozone layer during the ozone hole season. Observations made during the unusually large ozone hole of 2015 will be compared to ozone holes from 2003 to 2014 and interpreted in light of the meteorological conditions. Satellite observations will be used to get a more general picture of the size and depth of the ozone hole and will also be used to calculate various metrics for ozone hole severity. In 2003, 2005 and 2006, the ozone hole was relatively large with more ozone loss than normal. This is in particular the case for 2006, which by most ozone hole metrics was the most severe ozone hole on record. On the other hand, the ozone holes of 2004, 2007, 2010 and 2012, 2013 and 2014 were less severe than normal, and only the very special ozone hole of 2002 had less ozone depletion when one regards the ozone holes of the last decade. The South Polar vortex of 2015 was unusually stable and long-lived, so ozone depletion lasted longer than seen in recent years. The ozone hole area, i.e. the area where total ozone is less that 220 DU, averaged over the worst 60 consecutive days was larger in 2015 than in any other year since the beginning of the ozone hole era in the early 1980s.

  15. Space Telescope maintenance and refurbishment

    NASA Technical Reports Server (NTRS)

    Trucks, H. F.

    1983-01-01

    The Space Telescope (ST) represents a new concept regarding spaceborne astronomical observatories. Maintenance crews will be brought to the orbital worksite to make repairs and replace scientific instruments. For major overhauls the telescope can be temporarily returned to earth with the aid of the Shuttle. It will, thus, be possible to conduct astronomical studies with the ST for two decades or more. The five first-generation scientific instruments used with the ST include a wide field/planetary camera, a faint object camera, a faint object spectrograph, a high resolution spectrograph, and a high speed photometer. Attention is given to the optical telescope assembly, the support systems module, aspects of mission and science operations, unscheduled maintenance, contingency orbital maintenance, planned on-orbit maintenance, ground maintenance, ground refurbishment, and ground logistics.

  16. Ozone uptake by citrus trees exposed to a range of ozone concentrations

    NASA Astrophysics Data System (ADS)

    Fares, Silvano; Park, Jeong-Hoo; Ormeno, Elena; Gentner, Drew R.; McKay, Megan; Loreto, Francesco; Karlik, John; Goldstein, Allen H.

    2010-09-01

    The Citrus genus includes a large number of species and varieties widely cultivated in the Central Valley of California and in many other countries having similar Mediterranean climates. In the summer, orchards in California experience high levels of tropospheric ozone, formed by reactions of volatile organic compounds (VOC) with oxides of nitrogen (NO x). Citrus trees may improve air quality in the orchard environment by taking up ozone through stomatal and non-stomatal mechanisms, but they may ultimately be detrimental to regional air quality by emitting biogenic VOC (BVOC) that oxidize to form ozone and secondary organic aerosol downwind of the site of emission. BVOC also play a key role in removing ozone through gas-phase chemical reactions in the intercellular spaces of the leaves and in ambient air outside the plants. Ozone is known to oxidize leaf tissues after entering stomata, resulting in decreased carbon assimilation and crop yield. To characterize ozone deposition and BVOC emissions for lemon ( Citrus limon), mandarin ( Citrus reticulata), and orange ( Citrus sinensis), we designed branch enclosures that allowed direct measurement of fluxes under different physiological conditions in a controlled greenhouse environment. Average ozone uptake was up to 11 nmol s -1 m -2 of leaf. At low concentrations of ozone (40 ppb), measured ozone deposition was higher than expected ozone deposition modeled on the basis of stomatal aperture and ozone concentration. Our results were in better agreement with modeled values when we included non-stomatal ozone loss by reaction with gas-phase BVOC emitted from the citrus plants. At high ozone concentrations (160 ppb), the measured ozone deposition was lower than modeled, and we speculate that this indicates ozone accumulation in the leaf mesophyll.

  17. Reconciliation of Halogen-Induced Ozone Loss with the Total-Column Ozone Record

    NASA Technical Reports Server (NTRS)

    Shepherd, T. G.; Plummer, D. A.; Scinocca, J. F.; Hegglin, M. I.; Fioletov, V. E.; Reader, M. C.; Remsberg, E.; von Clarmann, T.; Wang, H. J.

    2014-01-01

    The observed depletion of the ozone layer from the 1980s onwards is attributed to halogen source gases emitted by human activities. However, the precision of this attribution is complicated by year-to-year variations in meteorology, that is, dynamical variability, and by changes in tropospheric ozone concentrations. As such, key aspects of the total-column ozone record, which combines changes in both tropospheric and stratospheric ozone, remain unexplained, such as the apparent absence of a decline in total-column ozone levels before 1980, and of any long-term decline in total-column ozone levels in the tropics. Here we use a chemistry-climate model to estimate changes in halogen-induced ozone loss between 1960 and 2010; the model is constrained by observed meteorology to remove the eects of dynamical variability, and driven by emissions of tropospheric ozone precursors to separate out changes in tropospheric ozone. We show that halogen-induced ozone loss closely followed stratospheric halogen loading over the studied period. Pronounced enhancements in ozone loss were apparent in both hemispheres following the volcanic eruptions of El Chichon and, in particular, Mount Pinatubo, which significantly enhanced stratospheric aerosol loads. We further show that approximately 40% of the long-term non-volcanic ozone loss occurred before 1980, and that long-term ozone loss also occurred in the tropical stratosphere. Finally, we show that halogeninduced ozone loss has declined by over 10% since stratospheric halogen loading peaked in the late 1990s, indicating that the recovery of the ozone layer is well underway.

  18. Reconciliation of halogen-induced ozone loss with the total-column ozone record

    NASA Astrophysics Data System (ADS)

    Shepherd, T. G.; Plummer, D. A.; Scinocca, J. F.; Hegglin, M. I.; Fioletov, V. E.; Reader, M. C.; Remsberg, E.; von Clarmann, T.; Wang, H. J.

    2014-06-01

    The observed depletion of the ozone layer from the 1980s onwards is attributed to halogen source gases emitted by human activities. However, the precision of this attribution is complicated by year-to-year variations in meteorology, that is, dynamical variability, and by changes in tropospheric ozone concentrations. As such, key aspects of the total-column ozone record, which combines changes in both tropospheric and stratospheric ozone, remain unexplained, such as the apparent absence of a decline in total-column ozone levels before 1980, and of any long-term decline in total-column ozone levels in the tropics. Here we use a chemistry-climate model to estimate changes in halogen-induced ozone loss between 1960 and 2010; the model is constrained by observed meteorology to remove the effects of dynamical variability, and driven by emissions of tropospheric ozone precursors to separate out changes in tropospheric ozone. We show that halogen-induced ozone loss closely followed stratospheric halogen loading over the studied period. Pronounced enhancements in ozone loss were apparent in both hemispheres following the volcanic eruptions of El Chichon and, in particular, Mount Pinatubo, which significantly enhanced stratospheric aerosol loads. We further show that approximately 40% of the long-term non-volcanic ozone loss occurred before 1980, and that long-term ozone loss also occurred in the tropical stratosphere. Finally, we show that halogen-induced ozone loss has declined by over 10% since stratospheric halogen loading peaked in the late 1990s, indicating that the recovery of the ozone layer is well underway.

  19. Robots for Aircraft Maintenance

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Marshall Space Flight Center charged USBI (now Pratt & Whitney) with the task of developing an advanced stripping system based on hydroblasting to strip paint and thermal protection material from Space Shuttle solid rocket boosters. A robot, mounted on a transportable platform, controls the waterjet angle, water pressure and flow rate. This technology, now known as ARMS, has found commercial applications in the removal of coatings from jet engine components. The system is significantly faster than manual procedures and uses only minimal labor. Because the amount of "substrate" lost is minimal, the life of the component is extended. The need for toxic chemicals is reduced, as is waste disposal and human protection equipment. Users of the ARMS work cell include Delta Air Lines and the Air Force, which later contracted with USBI for development of a Large Aircraft Paint Stripping system (LARPS). LARPS' advantages are similar to ARMS, and it has enormous potential in military and civil aircraft maintenance. The technology may also be adapted to aircraft painting, aircraft inspection techniques and paint stripping of large objects like ships and railcars.

  20. Symbolic Constraint Maintenance Grid

    NASA Technical Reports Server (NTRS)

    James, Mark

    2006-01-01

    Version 3.1 of Symbolic Constraint Maintenance Grid (SCMG) is a software system that provides a general conceptual framework for utilizing pre-existing programming techniques to perform symbolic transformations of data. SCMG also provides a language (and an associated communication method and protocol) for representing constraints on the original non-symbolic data. SCMG provides a facility for exchanging information between numeric and symbolic components without knowing the details of the components themselves. In essence, it integrates symbolic software tools (for diagnosis, prognosis, and planning) with non-artificial-intelligence software. SCMG executes a process of symbolic summarization and monitoring of continuous time series data that are being abstractly represented as symbolic templates of information exchange. This summarization process enables such symbolic- reasoning computing systems as artificial- intelligence planning systems to evaluate the significance and effects of channels of data more efficiently than would otherwise be possible. As a result of the increased efficiency in representation, reasoning software can monitor more channels and is thus able to perform monitoring and control functions more effectively.

  1. Cell Maintenance Systems

    NASA Technical Reports Server (NTRS)

    Morrison, D. R.

    1985-01-01

    Living human cells require attachment to a suitable surface and special culture conditions in order to grow. These requirements are modified and amplified when cells are taken into a weightless environment. Special handling and maintenance systems are required for routine laboratory procedures conducted in the Orbiter and in the Spacelab. Methods were developed to maintain cells in special incubators designed for the Orbiter middeck, however, electrophoresis and other experiments require cells to be harvested off of the culture substrate before they can be processed or used. The cell transport assembly (CTA) was flown on STS-8, and results show that improvements are required to maintain adequate numbers of cells in this device longer than 48 hours. The life sciences middeck centrifuge probably can be used, but modifications will be required to transfer cells from the CTA and keep the cells sterile. Automated systems such as the Skylab SO-15 flight hardware and crew operated systems are being evaluated for use on the Space Shuttle, Spacelab, and Space Station research modules.

  2. ADVANCED OXIDATION: OXALATE DECOMPOSITION TESTING WITH OZONE

    SciTech Connect

    Ketusky, E.; Subramanian, K.

    2012-02-29

    dissolution equilibrium, and then decomposed to {le} 100 Parts per Million (ppm) oxalate. Since AOP technology largely originated on using ultraviolet (UV) light as a primary catalyst, decomposition of the spent oxalic acid, well exposed to a medium pressure mercury vapor light was considered the benchmark. However, with multi-valent metals already contained in the feed, and maintenance of the UV light a concern; testing was conducted to evaluate the impact from removing the UV light. Using current AOP terminology, the test without the UV light would likely be considered an ozone based, dark, ferrioxalate type, decomposition process. Specifically, as part of the testing, the impacts from the following were investigated: (1) Importance of the UV light on the decomposition rates when decomposing 1 wt% spent oxalic acid; (2) Impact of increasing the oxalic acid strength from 1 to 2.5 wt% on the decomposition rates; and (3) For F-area testing, the advantage of increasing the spent oxalic acid flowrate from 40 L/min (liters/minute) to 50 L/min during decomposition of the 2.5 wt% spent oxalic acid. The results showed that removal of the UV light (from 1 wt% testing) slowed the decomposition rates in both the F & H testing. Specifically, for F-Area Strike 1, the time increased from about 6 hours to 8 hours. In H-Area, the impact was not as significant, with the time required for Strike 1 to be decomposed to less than 100 ppm increasing slightly, from 5.4 to 6.4 hours. For the spent 2.5 wt% oxalic acid decomposition tests (all) without the UV light, the F-area decompositions required approx. 10 to 13 hours, while the corresponding required H-Area decompositions times ranged from 10 to 21 hours. For the 2.5 wt% F-Area sludge, the increased availability of iron likely caused the increased decomposition rates compared to the 1 wt% oxalic acid based tests. In addition, for the F-testing, increasing the recirculation flow rates from 40 liter/minute to 50 liter/minute resulted in an

  3. Largest-ever Ozone Hole over Antarctica

    NASA Technical Reports Server (NTRS)

    2002-01-01

    A NASA instrument has detected an Antarctic ozone 'hole' (what scientists call an 'ozone depletion area') that is three times larger than the entire land mass of the United States-the largest such area ever observed. The 'hole' expanded to a record size of approximately 11 million square miles (28.3 million square kilometers) on Sept. 3, 2000. The previous record was approximately 10.5 million square miles (27.2 million square km) on Sept. 19, 1998. The ozone hole's size currently has stabilized, but the low levels in its interior continue to fall. The lowest readings in the ozone hole are typically observed in late September or early October each year. 'These observations reinforce concerns about the frailty of Earth's ozone layer. Although production of ozone-destroying gases has been curtailed under international agreements, concentrations of the gases in the stratosphere are only now reaching their peak. Due to their long persistence in the atmosphere, it will be many decades before the ozone hole is no longer an annual occurrence,' said Dr. Michael J. Kurylo, manager of the Upper Atmosphere Research Program, NASA Headquarters, Washington, DC. Ozone molecules, made up of three atoms of oxygen, comprise a thin layer of the atmosphere that absorbs harmful ultraviolet radiation from the Sun. Most atmospheric ozone is found between approximately six miles (9.5 km) and 18 miles (29 km) above the Earth's surface. Scientists continuing to investigate this enormous hole are somewhat surprised by its size. The reasons behind the dimensions involve both early-spring conditions, and an extremely intense Antarctic vortex. The Antarctic vortex is an upper-altitude stratospheric air current that sweeps around the Antarctic continent, confining the Antarctic ozone hole. 'Variations in the size of the ozone hole and of ozone depletion accompanying it from one year to the next are not unexpected,' said Dr. Jack Kaye, Office of Earth Sciences Research Director, NASA Headquarters

  4. Colorado Front Range Surface Ozone Analysis

    NASA Astrophysics Data System (ADS)

    McClure-Begley, A.; Petropavlovskikh, I. V.; Oltmans, S. J.; Kofler, J.; Petron, G.; Cothrel, H.

    2014-12-01

    The Colorado Front Range is a unique geographical region for air quality studies, including research of surface level ozone. Not only does surface ozone play a critical role in regulating the oxidation capacity of the atmosphere, but is a primary contributor to local smog and leads to public health complications and altered ecosystem functioning. The high frequency of sunny days, increasing population and pollution, and Mountain/Valley air dynamics of this region provide atmospheric conditions suitable for production and accumulation of ozone at the surface. This region of Colorado is currently in an ozone non-attainment status due to an assortment of contributing factors. Precursor emissions from pollution, wild-fires, and gas and oil production; along with stratosphere-troposphere exchange, can all result in high ozone episodes over the Colorado Front Range. To understand the dynamics of ozone accumulation in this region, Thermo-Scientific ozone monitors have been continuously sampling ozone from 4 different altitudes since the early 2000s. Analysis of ozone data in relation to Nitrogen Oxides (NOx), Methane (CH4), Carbon Monoxide (CO), wind-conditions and back-trajectory air mass origins help to address local ozone precursor emissions and resulting high ozone episodes. Increased ozone episodes are scrutinized with regards to dominant wind direction to determine main precursor emission sources. Analysis of this data reveals a strong influence of precursor emissions from the North-East wind sector, with roughly 50% of ozone exceedances originating from winds prevailing from this direction. Further, correlation with methane is enhanced when prevailing winds are from the North-East; indicative of influence from natural gas processes and feedlot activity. Similar analysis is completed for the North-West wind sector exceedances, with strong correlation to carbon monoxide; likely related to emissions from biomass burning events and forest fires. In depth analysis of

  5. Ozone loss hits us where we live

    SciTech Connect

    Appenzeller, T.

    1991-11-01

    The news about Earth's ozone layer just keeps getting worse. Three weeks ago, NASA researchers reported that the ozone hole over the Antarctic hit a record depth this year. Now comes the United Nations Environment Program, together with the World Meteorological Organization, with an even more distressing assessment of the state of the ozone layer. For the first time, the 80-member UN panel said, measurements show the ozone shield is eroding over temperate latitudes in summer, exposing crops and people to a larger dose of ultraviolet light just when they are most vulnerable. For a small group of atmospheric modelers, though, the bad news is bittersweet. Four months ago researchers predicted summertime ozone losses of just the magnitude the UN panel has now reported: about 3% over the past decade for northern temperate latitudes. Ozone modelers are encouraged by the agreement, particularly because other models are now yielding the same result. The modeling effort was spurred by earlier measurements showing a serious erosion of ozone at midlatitudes, mainly in winter. In 1988, an analysis of data collected from the ground showed that ozone levels at the latitude of the US were dropping by about 1% to 3% per decade; last April, an analysis of measurements from the satellite-borne Total Ozone Mapping Spectrometer boosted that figure to between 4% and 5%. Those findings raised the question: What mechanisms could be driving the midlatitude losses The fact that the losses seemed to be concentrated in winter suggested one possibility. The winter ozone losses at the poles are driven by chemical reactions taking place on the surface of ice crystals in polar stratospheric clouds. Such clouds don't form at temperate latitudes. But some researchers suggested that masses of air already depleted in ozone or enriched in reactive chlorine by the chemistry in the polar clouds might be escaping to temperate latitudes during the winter.

  6. Compact Ozone Lidar for Atmospheric Ozone and Aerosol Measurements

    NASA Technical Reports Server (NTRS)

    Marcia, Joel; DeYoung, Russell J.

    2007-01-01

    A small compact ozone differential absorption lidar capable of being deployed on a small aircraft or unpiloted atmospheric vehicle (UAV) has been tested. The Ce:LiCAF tunable UV laser is pumped by a quadrupled Nd:YLF laser. Test results on the laser transmitter demonstrated 1.4 W in the IR and 240 mW in the green at 1000 Hz. The receiver consists of three photon-counting channels, which are a far field PMT, a near field UV PMT, and a green PMT. Each channel was tested for their saturation characteristics.

  7. Tropospheric ozone production regions and the intercontinental origins of surface ozone over Europe

    NASA Astrophysics Data System (ADS)

    Derwent, Richard G.; Utembe, Steven R.; Jenkin, Michael E.; Shallcross, Dudley E.

    2015-07-01

    Ozone tagged labelling schemes have been implemented in a global Lagrangian chemistry-transport model to identify the intercontinental origins of surface ozone in Europe. Stratosphere-troposphere exchange gave rise to between 3 and 5 ppb across Europe, whereas the mid-latitudes of the Middle East, Asia and the Pacific Ocean region contributed 6-8 ppb. Surface ozone levels of 10-16 ppb were associated with the mid-latitudes of North America and the North Atlantic Ocean regions. Appreciable intercontinental ozone production occurred downwind of continental regions and above the surface layer. Intercontinental ozone formation and transport from tropical regions contributed about 4 ppb and was much less efficient compared with that from mid-latitudes. There were approaching 60 chemical processes driving intercontinental ozone formation, of which the HO2 + NO, CH3O2 + NO and CH3COO2 + NO reactions were the most important. Ozone production appeared to be driven by OH oxidation of secondary reaction products rather than the oxidation of primary emitted VOCs. The largest intercontinental ozone contributions amounted to about 20 ppb from North America to European baseline stations, 14 ppb from Asia to North American baseline stations and 10 ppb from Asia to European baseline stations. It is possible that changing intercontinental ozone production and transport could have led to seasonal ozone trends and shifts in seasonal cycles at northern hemisphere mid-latitude baseline ozone monitoring stations.

  8. Sensitivity Modeling Study for an Ozone Occurrence during the 1996 Paso Del Norte Ozone Campaign

    PubMed Central

    Lu, Duanjun; Reddy, Remata S.; Fitzgerald, Rosa; Stockwell, William R.; Williams, Quinton L.; Tchounwou, Paul B.

    2008-01-01

    Surface ozone pollution has been a persistent environmental problem in the US and Europe as well as the developing countries. A key prerequisite to find effective alternatives to meeting an ozone air quality standard is to understand the importance of local anthropogenic emissions, the significance of biogenic emissions, and the contribution of long-range transport. In this study, an air quality modeling system that includes chemistry and transport, CMAQ, an emission processing model, SMOKE, and a mesoscale numerical meteorological model, WRF, has been applied to investigate an ozone event occurring during the period of the 1996 Paso del Norte Ozone Campaign. The results show that the modeling system exhibits the capability to simulate this high ozone occurrence by providing a comparable temporal variation of surface ozone concentration at one station and to capture the spatial evolution of the event. Several sensitivity tests were also conducted to identify the contributions to high surface ozone concentration from eight VOC subspecies, biogenic VOCs, anthropogenic VOCs and long-range transportation of ozone and its precursors. It is found that the reductions of ETH, ISOP, PAR, OLE and FORM help to mitigate the surface ozone concentration, and like anthropogenic VOCs, biogenic VOC plays a nonnegligible role in ozone formation. But for this case, long-range transport of ozone and its precursors appears to produce an insignificant contribution. PMID:19190351

  9. Recent Stratospheric Ozone Measurements over Ankara-Turkey and Evaluation of Ozone Profiles

    NASA Astrophysics Data System (ADS)

    Ozkizilkaya, O.; Incecik, S.; Kahya, C.

    2009-04-01

    Satellite, spectrophotometer and ozonesonde measurement systems are widely used to determine total column of ozone and its properties in troposphere and stratosphere. The differences between these measurement systems are the main research areas in terms of their techniques and results. The present study deals with to compare of satellite total ozone measurements from OMI and SEVIRI instruments, Brewer MKIII spectrophotometer and ECC ozonesonde total ozone measurements and to make an assessment of the ozone in troposphere and stratosphere using ECC and Brewer ozone profiles over Ankara (39o55´N; 32o55´E) located at the centre of Anatolia. In this study, Brewer MKIII, OMI and SEVIRI total ozone data of Ankara for the period January -December 2007 were used to make an intercomparison of monthly average total ozone measurements. The percentage differences between the data sets were calculated. It is aimed to define which remote sensing measurement techniques give the most accurate and reliable results. In order to verify the data obtained by remote sensing methods, 21 daily ECC total ozone measurements for the same period were used. Brewer, OMI and SEVIRI measurements available for the corresponding days were taken into account. Furthermore, in order to understand atmospheric ozone content, a total ozone retrieval algorithm from ECC sounding was applied to both troposphere and stratosphere to determine the ozone contents. According to the comparisons, it was found that Brewer and OMI monthly average total ozone measurements show good agreement but SEVIRI overestimates; maximum differences between the measurements occur mostly between July and October. Maximum percentage differences between Brewer and OMI, SEVIRI and Brewer, SEVIRI and OMI were found -7.3%, 17% and 17% respectively. The mean absolute differences between Brewer and OMI were calculated as 2.4%; on the other hand SEVIRI has 10.4% mean absolute difference from Brewer and OMI. The results of the comparison

  10. Neural network scheme for the retrieval of total ozone from Global Ozone Monitoring Experiment data.

    PubMed

    Müller, Martin D; Kaifel, Anton; Weber, Mark; Burrows, John P

    2002-08-20

    A novel approach to retrieving total ozone columns from the ERS2 GOME (Global Ozone Monitoring Experiment) spectral data has been developed. With selected GOME wavelength regions, from clear and cloudy pixels alike plus orbital and instrument data as input, a feed-forward neural network was trained to determine total ozone in a one-step inverse retrieval procedure. To achieve this training, ground-based total ozone measurements from the World Ozone and Ultraviolet Data Center (WOUDC) for the years 1996-2000, supplemented with Dobson-corrected Total Ozone Mapping Spectrometer (TOMS) data to provide global coverage, were collocated with GOME ground pixels into a training data set. Validation of the neural-network-retrieved ozone values relative to independent ground stations yielded a rms error of better than 11 Dobson units. Comparisons performed on the basis of operationally available TOMS and GOME level-3 maps exhibit good agreement in general, with a latitude-dependent offset. PMID:12206215

  11. Tropospheric Ozone Near-Nadir-Viewing IR Spectral Sensitivity and Ozone Measurements from NAST-I

    NASA Technical Reports Server (NTRS)

    Zhou, Daniel K.; Smith, William L.; Larar, Allen M.

    2001-01-01

    Infrared ozone spectra from near nadir observations have provided atmospheric ozone information from the sensor to the Earth's surface. Simulations of the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I) from the NASA ER-2 aircraft (approximately 20 km altitude) with a spectral resolution of 0.25/cm were used for sensitivity analysis. The spectral sensitivity of ozone retrievals to uncertainties in atmospheric temperature and water vapor is assessed in order to understand the relationship between the IR emissions and the atmospheric state. In addition, ozone spectral radiance sensitivity to its ozone layer densities and radiance weighting functions reveals the limit of the ozone profile retrieval accuracy from NAST-I measurements. Statistical retrievals of ozone with temperature and moisture retrievals from NAST-I spectra have been investigated and the preliminary results from NAST-I field campaigns are presented.

  12. An Ozone Increase in the Antarctic Summer Stratosphere: A Dynamical Response to the Ozone Hole

    NASA Technical Reports Server (NTRS)

    Stolarski, R. S.; Douglass, A. R.; Gupta, M.; Newman, P. A.; Pawson, S.; Schoeberl, M. R.; Nielsen, J. E.

    2007-01-01

    Profiles of ozone concentration retrieved from the SBUV series of satellites show an increase between 1979 and 1997 in the summertime Antarctic middle stratosphere (approx. 25-10 hPa). Data over the South Pole from ozone sondes confirm the increase. A similar ozone increase is produced in a chemistry climate model that allows feedback between constituent changes and the stratospheric circulation through radiative heating. A simulation that excludes the radiative coupling between predicted ozone and the circulation does not capture this ozone increase. We show that the ozone increase in our model simulations is caused by a dynamical feedback in response to the changes in the stratospheric wind fields forced by the radiative perturbation associated with the Antarctic ozone hole.

  13. Health maintenance in women.

    PubMed

    Riley, Margaret; Dobson, Margaret; Jones, Elizabeth; Kirst, Nell

    2013-01-01

    The health maintenance examination is an opportunity to focus on disease prevention and health promotion. The patient history should include screening for tobacco use, alcohol misuse, intimate partner violence, and depression. Premenopausal women should receive preconception counseling and contraception as needed, and all women planning or capable of pregnancy should take 400 to 800 mcg of folic acid per day. High-risk sexually active women should be counseled on reducing the risk of sexually transmitted infections, and screened for chlamydia, gonorrhea, and syphilis. All women should be screened for human immunodeficiency virus. Adults should be screened for obesity and elevated blood pressure. Women 20 years and older should be screened for dyslipidemia if they are at increased risk of coronary heart disease. Those with sustained blood pressure greater than 135/80 mm Hg should be screened for type 2 diabetes mellitus. Women 55 to 79 years of age should take 75 mg of aspirin per day when the benefits of stroke reduction outweigh the increased risk of gastrointestinal hemorrhage. Women should begin cervical cancer screening by Papanicolaou test at 21 years of age, and if results have been normal, screening may be discontinued at 65 years of age or after total hysterectomy. Breast cancer screening with mammography may be considered in women 40 to 49 years of age based on patients' values, and potential benefits and harms. Mammography is recommended biennially in women 50 to 74 years of age. Women should be screened for colorectal cancer from 50 to 75 years of age. Osteoporosis screening is recommended in women 65 years and older, and in younger women with a similar risk of fracture. Adults should be immunized at recommended intervals according to guidelines from the Centers for Disease Control and Prevention. PMID:23317023

  14. [Maintenance therapy for colorectal cancer].

    PubMed

    Yamaguchi, Shigeo; Kato, Shunsuke

    2014-08-01

    Some trials have demonstrated the benefits of maintenance chemotherapy for advanced colorectal cancer. In chemotherapeutic strategies for advanced colorectal cancer, chemotherapy-related toxicity prevention and quality of life(QOL)maintenance are more important than the introduction of a strong regimen, especially when additional surgery is not possible. In Japan, the combination of a folinic acid/5-fluorouracil/oxaliplatin(FOLFOX)regimen and bevacizumab is a popular first-line chemotherapy regimen. However, despite its effectiveness, neuropathy or hand-foot syndrome after 5 or 6 cycles tends to lead to chemotherapy withdrawal. CAIRO3 trial reported the effectiveness of capecitabine and bevacizumab as a maintenance chemotherapy regimen. Additionally, the ML18147 trial demonstrated that bevacizumab beyond progression(BBP)prolonged overall survival(OS)and progression free survival(PFS)in patients with advanced colorectal cancer. Although those trials demonstrated the effectiveness of continuous or maintenance bevacizumab administration, no trials have compared the effectiveness of cytotoxic drugs with bevacizumab as maintenance therapies. Moreover, controversy exists regarding the selection of drugs as a maintenance therapy and the identification of patients who would benefit from maintenance therapy. PMID:25132024

  15. Operational Interventions to Maintenance Error

    NASA Technical Reports Server (NTRS)

    Kanki, Barbara G.; Walter, Diane; Dulchinos, VIcki

    1997-01-01

    A significant proportion of aviation accidents and incidents are known to be tied to human error. However, research of flight operational errors has shown that so-called pilot error often involves a variety of human factors issues and not a simple lack of individual technical skills. In aircraft maintenance operations, there is similar concern that maintenance errors which may lead to incidents and accidents are related to a large variety of human factors issues. Although maintenance error data and research are limited, industry initiatives involving human factors training in maintenance have become increasingly accepted as one type of maintenance error intervention. Conscientious efforts have been made in re-inventing the team7 concept for maintenance operations and in tailoring programs to fit the needs of technical opeRAtions. Nevertheless, there remains a dual challenge: 1) to develop human factors interventions which are directly supported by reliable human error data, and 2) to integrate human factors concepts into the procedures and practices of everyday technical tasks. In this paper, we describe several varieties of human factors interventions and focus on two specific alternatives which target problems related to procedures and practices; namely, 1) structured on-the-job training and 2) procedure re-design. We hope to demonstrate that the key to leveraging the impact of these solutions comes from focused interventions; that is, interventions which are derived from a clear understanding of specific maintenance errors, their operational context and human factors components.

  16. Ozone fluxes from Citrus species exposed to different levels of atmospheric ozone concentration

    NASA Astrophysics Data System (ADS)

    Fares, S.; Ormeño, E.; Park, J.; Gentner, D. R.; McKay, M.; Karlik, J. F.; Goldstein, A. H.

    2009-12-01

    Citrus includes a large number of species and varieties widely cultivated in the Central Valley of California and in many other countries having Mediterranean climates. Orchards in California often experience high levels of tropospheric ozone, formed from reactions of VOC and NOx. On one hand, citrus trees may contribute to cleaning the air when the ozone is deposited on the canopies through stomatal and non-stomatal mechanisms, but on the other hand ozone is known to oxidize leaf tissues after entering stomata, resulting in a decrease of carbon assimilation and decrease in crop yield. To characterize ozone deposition for lemon (Citrus limon), mandarin (Citrus reticulata), and orange (Citrus sinensis), we designed branch enclosures which allowed a direct measurement of ozone uptake under different physiological conditions obtained in a greenhouse-controlled environment. A second aim of this study was to test the capability of Citrus species to emit volatile organic compounds which may play a key role in locally removing ozone through chemical reactions in the intercellular spaces and in the gas phase or forming more ozone on the regional scale through reactions with NO¬x. Ozone uptake was quantified to be in the range of 5-12 nmol m-2 s-1 under the highest conditions of physiological activity. Under high levels of ozone concentration, measured ozone deposition was lower than modeled ozone deposition based on the level of stomatal aperture. Our study evaluates the possible role of VOC in scavenging ozone through gas-phase reactions, but the results instead lead to the hypothesis of an accumulation of ozone in the intercellular spaces resulting in a decrease of ozone fluxes for the citrus species studied.

  17. Looking at Ozone From a New Angle: Shuttle Ozone Limb Sounding Experiment-2 (SOLSE-2)

    NASA Technical Reports Server (NTRS)

    McPeters, Richard; Hilsenrath, Ernest; Janz, Scott; Brown, Tammy (Technical Monitor)

    2002-01-01

    The ozone layer above Earth is our planet's fragile sunscreen, protecting people, vegetation, and wildlife. NASA has been measuring ozone for more than 20 years by looking down, but SOLSE-2 will show that more information is available by looking at ozone from the side, at Earth's limb or atmospheric boundary. When the ozone layer is compromised, increased ultraviolet (UV) levels from the sun cause health problems ranging from severe sunburns to skin cancer and cataracts. A concerted global effort has been made to reduce or eliminate the production of chemicals that deplete ozone, but the ozone layer is not expected to recover for many decades because these chemicals can remain active in the atmosphere for up to 100 years. We know now that ozone monitoring needs to be focused in the lower stratosphere. The discovery of the ozone hole in 1985 demonstrated that very large changes in ozone were occurring in the lower stratosphere near 20 km, instead of the upper stratosphere as first expected, and where current ozone instruments are focused. Measuring ozone from a tangential perspective that is centered at the limb provides ozone profiles concentrated in the lower stratosphere. The first flight of SOLSE proved that this technique achieves the accuracy and coverage of traditional measurements, and surpasses the altitude resolution and depth of retrieval of conventional techniques. Results from the first flight convinced the science community to design the next generation ozone monitoring satellite based on SOLSE. The Ozone Mapping and Profiling Suite (OMPS) is currently being built for the NPOESS satellite. The primary objective of SOLSE-2 is to confirm the promising results of the first flight over a wider range of viewing conditions and spectral wavelengths. Sometimes a really hard problem can be solved when you look at it from a different angle! While scientists conduct research, protect yourself by observing the UV index and spend less unprotected time outdoors.

  18. The changing oxidizing environment in London - trends in ozone precursors and their contribution to ozone production

    NASA Astrophysics Data System (ADS)

    von Schneidemesser, E.; Vieno, M.; Monks, P. S.

    2014-01-01

    Ground-level ozone is recognized to be a threat to human health (WHO, 2003), have a deleterious impact on vegetation (Fowler et al., 2009), is also an important greenhouse gas (IPCC, 2007) and key to the oxidative ability of the atmosphere (Monks et al., 2009). Owing to its harmful effect on health, much policy and mitigation effort has been put into reducing its precursors - the nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs). The non-linear chemistry of tropospheric ozone formation, dependent mainly on NOx and NMVOC concentrations in the atmosphere, makes controlling tropospheric ozone complex. Furthermore, the concentration of ozone at any given point is a complex superimposition of in-situ produced or destroyed ozone and transported ozone on the regional and hemispheric-scale. In order to effectively address ozone, a more detailed understanding of its origins is needed. Here we show that roughly half (5 μg m-3) of the observed increase in urban (London) ozone (10 μg m-3) in the UK from 1998 to 2008 is owing to factors of local origin, in particular, the change in NO : NO2 ratio, NMVOC : NOx balance, NMVOC speciation, and emission reductions (including NOx titration). In areas with previously higher large concentrations of nitrogen oxides, ozone that was previously suppressed by high concentrations of NO has now been "unmasked", as in London and other urban areas of the UK. The remaining half (approximately 5 μg m-3) of the observed ozone increase is attributed to non-local factors such as long-term transport of ozone, changes in background ozone, and meteorological variability. These results show that a two-pronged approach, local action and regional-to-hemispheric cooperation, is needed to reduce ozone and thereby population exposure, which is especially important for urban ozone.

  19. INTERSUBJECT VARIABILITY IN HUMAN ACUTE OZONE RESPONSIVENESS

    EPA Science Inventory

    Individuals exposed to ozone experience a wide range in the magnitudes of lung function decrements and symptoms produced. hese intersubject differences in response are reproducible over periods of time of at least one year, suggesting that responsiveness to ozone is a characteris...

  20. UNDERSTANDING ECOSYSTEM RESPONSE TO OZONE STRESS

    EPA Science Inventory

    Ecological risk assessment of ozone impact requires consideration of many factors that, perhaps, are not of concern in human health risk assessment. The episodic nature of ozone exposure, functional complexity of species, and broad spatial and temporal scales characteristic of n...

  1. Recovery of the Antarctic Ozone Hole

    NASA Technical Reports Server (NTRS)

    Newman, Paul A.; Nash, Eric R.; Kawa, S. Randolph; Montzka, Steve; Schauffler, Sue; Stolarski, Richard S.; Douglass, Anne R.; Pawson, Steven; Nielsen, J. Eric

    2006-01-01

    The Antarctic ozone hole develops each year and culminates by early Spring. Antarctic ozone values have been monitored since 1979 using satellite observations from the TOMS and OMI instruments. The severity of the hole has been assessed using the minimum total ozone value from the October monthly mean (depth of the hole), the average size during the September-October period, and the ozone mass deficit. Ozone is mainly destroyed by halogen catalytic cycles, and these losses are modulated by temperature variations in the collar of the polar lower stratospheric vortex. In this presentation, we show the relationships of halogens and temperature to both the size and depth of the hole. Because atmospheric halogen levels are responding to international agreements that limit or phase out production, the amount of halogens in the stratosphere should decrease over the next few decades. We use two methods to estimate ozone hole recovery. First, we use projections of halogen levels combined with age-of-air estimates in a parametric model. Second, we use a coupled chemistry climate model to assess recovery. We find that the ozone hole is recovering at an extremely slow rate and that large ozone holes will regularly recur over the next 2 decades. Furthermore, full recovery to 1980 levels will not occur until approximately 2068. We will also show some error estimates of these dates and the impact of climate change on the recovery.

  2. College Students' Understanding of Atmospheric Ozone Formation

    ERIC Educational Resources Information Center

    Howard, Kristen E.; Brown, Shane A.; Chung, Serena H.; Jobson, B. Thomas; VanReken, Timothy M.

    2013-01-01

    Research has shown that high school and college students have a lack of conceptual understanding of global warming, ozone, and the greenhouse effect. Most research in this area used survey methodologies and did not include concepts of atmospheric chemistry and ozone formation. This study investigates college students' understandings of atmospheric…

  3. Processes Affecting Tropospheric Ozone over Africa

    NASA Technical Reports Server (NTRS)

    Diab, Roseanne D.; Thompson, Anne M.

    2004-01-01

    This is a Workshop Report prepared for Eos, the weekly AGU magazine, The workshop took place between 26-28 January 2004 at the University of KwaZulu-Natal in Durban, South Africa and was attended by 26 participants (http//www.geography.und.ac.za). Considerable progress has been made in ozone observations except for northern Africa (large data gaps) and west Africa (to be covered by the French-sponsored AMMA program). The present-day ozone findings were evaluated and reviewed by speakers using Aircraft data (MOZAIC program), NASA satellites (MOPITT, TRMM, TOMS) and ozone soundings (SHADOZ). Besides some ozone gaps, there are challenges posed by the need to assess the relative strengths of photochemical and dynamic influences on the tropospheric ozone budget. Biogenic, biofuels, biomass burning sources of ozone precursors remain highly uncertain. Recent findings (by NASA's Chatfield and Thompson, using satellite and sounding data) show significant impact of Indian Ocean pollution on African ozone. European research on pollutants over the Mediterranean and the middle east, that suggests that ozone may be exported to Africa from these areas, also needs to be considered.

  4. Global Warming: Lessons from Ozone Depletion

    ERIC Educational Resources Information Center

    Hobson, Art

    2010-01-01

    My teaching and textbook have always covered many physics-related social issues, including stratospheric ozone depletion and global warming. The ozone saga is an inspiring good-news story that's instructive for solving the similar but bigger problem of global warming. Thus, as soon as students in my physics literacy course at the University of…

  5. ECONOMIC EFFECTS OF OZONE ON AGRICULTURE

    EPA Science Inventory

    Past attempts to assess the monetary impacts of ozone or other air pollutants on agriculture have had only sparse plant science information on which to base an assessment. This paper reports on an economic assessment of the effects of simulated changes in ambient ozone on U.S. ag...

  6. When Will the Antarctic Ozone Hole Recover?

    NASA Technical Reports Server (NTRS)

    Newman, Paul A.

    2006-01-01

    The Antarctic ozone hole develops each year and culminates by early spring (late September - early October). Antarctic ozone values have been monitored since 1979 using satellite observations from the TOMS instrument. The severity of the hole has been assessed from TOMS using the minimum total ozone value from the October monthly mean (depth of the hole) and by calculating the average area coverage during this September-October period. Ozone is mainly destroyed by halogen (chlorine and bromine) catalytic cycles, and these losses are modulated by temperature variations in the collar of the polar lower stratospheric vortex. In this talk, I will show the relationships of halogens and temperature to both the size and depth of the hole. Because atmospheric halogen levels are responding to international agreements that limit or phase out production, the amount of halogens in the stratosphere should decrease over the next few decades. Using projections of halogen levels combined with age-of-air estimates, we find that the ozone hole is recovering at an extremely slow rate and that large ozone holes will regularly recur over the next 2 decades. The ozone hole will begin to show first signs of recovery in about 2023, and the hole will fully recover to pre-1980 levels in approximately 2070. This 2070 recovery is 20 years later than recent projections. I will also discuss current assessments of mid-latitude ozone recovery.

  7. Stable ozone layer in Norway and USSR

    NASA Technical Reports Server (NTRS)

    Henriksen, K.; Svenoe, T.; Terez, E. I.; Terez, G. A.; Roldugin, V.; Larsen, S. H. H.

    1994-01-01

    Long-term column ozone density measurements have been carried out in Norway and USSR. Data from Tromso and two meridional chains in USSR are analyzed, and most of the stations show that no significant decreasing trend in ozone has occurred during the last two decades.

  8. Fires, atmospheric chemistry, and the ozone layer

    SciTech Connect

    Cicerone, R.J. )

    1994-03-04

    During biomass burning, large amounts of methyl bromide are produced. Free bromine atoms can catalyze the destruction of ozone through reactions with oxygen and chlorin. This article examines the role of methyl bromide in ozone destruction, and the amounts of natural and anthropogenic methyl bromide production.

  9. Absorption of ozone by porous particles

    SciTech Connect

    Afanas'ev, V.P.; Dorofeev, S.B.; Sinitsyn, V.I.; Smirnov, B.M.

    1981-11-01

    The absorption of ozone by porous zeolite, silica gel, and activated carbon particles has been studied experimentally. It was shown that in addition to absorption, dissociation of ozone on the surface plays an important and sometimes decisive role. The results obtained were used to analyze the nature of ball lightning.

  10. Ozone and SIRT3: an unexplored paradigm.

    PubMed

    Syed, Deeba N; Mukhtar, Hasan

    2013-06-01

    Exposure to environmentally relevant doses of ozone induces oxidative stress and is associated with adverse effects at tissue level. Delineating the role of sirtuin3, involved in cellular energy homoeostasis, in the response of skin to ozone can be a step towards developing prevention strategies against cutaneous pathologies. PMID:23711063

  11. Ozone processing of foods and beverages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ozone has a long history of use as a disinfectant in food and beverage processing. In the United States, the application of ozone to disinfect bottled water was approved as Generally Recognized As Safe (GRAS) in 1982. Later it was approved as a sanitizing agent for bottled water treatment lines. Ozo...

  12. Validation of UARS MLS Ozone Measurements

    NASA Technical Reports Server (NTRS)

    Froidevaux, L.; Read, W. G.; Lungu, T. A; Cofield, R. E.; Fishbein, E. F.; Flower, D. A.; Jarnot, R. f.; Ridenoure, B. P.; Shippony, Z.; Waters, J. W.; Margitan, J. J.; Stachnik, I. S.; Peckham, G. E.; Braathen, G.; Deshler, T.; Fishman, J.; Hofmann, D. J.; Oltmans, S. J.; McDermid, R. A.

    1994-01-01

    This paper describes the validation of ozone data from the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS). The MLS ozone retrievals are obtained from the calibrated microwave radiances (emission spectra) in two separate bands, at frequencies near 205 and 183 GHz.

  13. HUMAN EXPOSURE SYSTEM FOR CONTROLLED OZONE ATMOSPHERES

    EPA Science Inventory

    An experimental exposure system for health effects research in environmental pollutants that permits the introduction and control of ozone (O3) to an acrylic plastic chamber in which a human subject actively resides is described. Ozone is introduced into the chamber air intake an...

  14. Antarctic ozone hole hits record depth

    SciTech Connect

    Not Available

    1991-10-18

    A bad year for the ozone over Antarctica looked like a good bet this year. For the past 2 years, stratospheric ozone destruction has equaled the record set in 1987. Now things look even worse, with a record-setting ozone hole. In 1987, 1989, and 1990, the minimum amount of ozone over Antarctica early each October was 120 to 125 Dobson units compared to the typical level of 220 that prevailed before manmade Chlorofluorocarbons (CFCs) began eating into the ozone layer. The depletion allowed as much as twice the usual amount of biologically damaging ultraviolet light to reach the earth's surface. But researchers took some comfort in the fact that the hole seemed to have hit a barrier to further losses. Now that barrier may have been breached. On 6 October, the satellite-borne Total Ozone Mapping Spectrometer detected an ozone minimum of 110 Dobson units. The region of the lower stratosphere where icy cloud particles and the chlorine of CFCs combine to destroy ozone - between 14 and 24 kilometers - looks much the same as it did in 1987.

  15. Ozone profiles above Palmer Station, Antarctica

    NASA Technical Reports Server (NTRS)

    Torres, Arnold L.; Brothers, George

    1988-01-01

    NASA's Goddard Space Flight Center/Wallops Flight Facility conducted a series of 52 balloon-borne measurements of vertical ozone profiles over the National Science Foundation (NSF) research facility at Palmer Station, Antarctica (64 deg 46 S, 64 deg 3 W) between August 9 and October 24, 1987. High resolution measurements were made from ground level to an average of 10 mb. While much variation was seen in the profile amounts of ozone, it is clear that a progressive depletion of ozone occurred during the measurement period, with maximum depletion taking place in the 17 to 19 km altitude region. Ozone partial pressures dropped by about 95 percent in this region. Shown here are plotted time dependences of ozone amounts observed at 17 km and at arbitrarily selected altitudes below (13 km) and above (24 km) the region of maximum depletion. Ozone partial pressure at 17 km is about 150nb in early August, and has decreased to less than 10nb in the minimums in October. The loss rate is of the order of 1.5 percent/day. In summary, a progressive depletion in stratospheric ozone over Palmer Station was observed from August to October, 1987. Maximum depletion occurred in the 17 to 19 km range, and amounted to 95 percent. Total ozone overburden decreased by up to 50 percent during the same period.

  16. The economics of satellite maintenance

    NASA Technical Reports Server (NTRS)

    Derocher, W. L., Jr.; Sosnay, R. G.

    1975-01-01

    The primary goal of the space transportation system - to reduce the cost of space programs while satisfying their mission requirements - can be enhanced by the proper choice of a satellite-maintenance concept. This paper develops the life-cycle costs of performing an automated satellite program during the shuttle era in three competitive modes: expendable, ground-refurbishable, and in-orbit maintainable. In-orbit maintenance is shown to be the most economic maintenance mode for both low- and high-earth orbits.

  17. The Case of Ozone Depletion

    NASA Technical Reports Server (NTRS)

    Lambright, W. Henry

    2005-01-01

    While the National Aeronautics and Space Administration (NASA) is widely perceived as a space agency, since its inception NASA has had a mission dedicated to the home planet. Initially, this mission involved using space to better observe and predict weather and to enable worldwide communication. Meteorological and communication satellites showed the value of space for earthly endeavors in the 1960s. In 1972, NASA launched Landsat, and the era of earth-resource monitoring began. At the same time, in the late 1960s and early 1970s, the environmental movement swept throughout the United States and most industrialized countries. The first Earth Day event took place in 1970, and the government generally began to pay much more attention to issues of environmental quality. Mitigating pollution became an overriding objective for many agencies. NASA's existing mission to observe planet Earth was augmented in these years and directed more toward environmental quality. In the 1980s, NASA sought to plan and establish a new environmental effort that eventuated in the 1990s with the Earth Observing System (EOS). The Agency was able to make its initial mark via atmospheric monitoring, specifically ozone depletion. An important policy stimulus in many respects, ozone depletion spawned the Montreal Protocol of 1987 (the most significant international environmental treaty then in existence). It also was an issue critical to NASA's history that served as a bridge linking NASA's weather and land-resource satellites to NASA s concern for the global changes affecting the home planet. Significantly, as a global environmental problem, ozone depletion underscored the importance of NASA's ability to observe Earth from space. Moreover, the NASA management team's ability to apply large-scale research efforts and mobilize the talents of other agencies and the private sector illuminated its role as a lead agency capable of crossing organizational boundaries as well as the science-policy divide.

  18. Ozone Gardens for the Citizen Scientist

    NASA Technical Reports Server (NTRS)

    Pippin, Margaret; Reilly, Gay; Rodjom, Abbey; Malick, Emily

    2016-01-01

    NASA Langley partnered with the Virginia Living Museum and two schools to create ozone bio-indicator gardens for citizen scientists of all ages. The garden at the Marshall Learning Center is part of a community vegetable garden designed to teach young children where food comes from and pollution in their area, since most of the children have asthma. The Mt. Carmel garden is located at a K-8 school. Different ozone sensitive and ozone tolerant species are growing and being monitored for leaf injury. In addition, CairClip ozone monitors were placed in the gardens and data are compared to ozone levels at the NASA Langley Chemistry and Physics Atmospheric Boundary Layer Experiment (CAPABLE) site in Hampton, VA. Leaf observations and plant measurements are made two to three times a week throughout the growing season.

  19. Copenhagen delegates advance phaseout of ozone depleters

    SciTech Connect

    Kirschner, E.

    1992-12-09

    As expected, delegates at the United Nations Ozone Layer Conference in Copenhagen sped up ozone depleter phaseouts from the 1987 Montreal Protocol and the 1990 London amendments. The changes bring the worldwide production phaseout of chlorofluorocarbons (CFCs) and other ozone depleters in developed countries in line with U.S. and European plans announced earlier this year. Adjustments to the protocol, which are binding on the signatories, change the phaseout for CFC, carbon tetrachloride, and methyl chloroform production and consumption to January 1, 1996 from 2000. The 75% reduction of 1986 levels from CFCs by January 1, 1994 is a compromise between European pressure for an 85% cut and the US goal of 70%. Halon production is to end January 1, 1994, as anticipated. Developing countries continue to have a 10-year grace period. Friends of the Earth ozone campaign director Liz Cook counters that the phaseout dates were scheduled with concern for the chemical industry, not for the ozone layer.

  20. Improved reference models for middle atmosphere ozone

    NASA Technical Reports Server (NTRS)

    Keating, G. M.; Pitts, M. C.; Chen, C.

    1990-01-01

    This paper describes the improvements introduced into the original version of ozone reference model of Keating and Young (1985, 1987) which is to be incorporated in the next COSPAR International Reference Atmosphere (CIRA). The ozone reference model will provide information on the global ozone distribution (including the ozone vertical structure as a function of month and latitude from 25 to 90 km) combining data from five recent satellite experiments: the Nimbus 7 LIMS, Nimbus 7 SBUV, AE-2 Stratospheric Aerosol Gas Experiment (SAGE), Solar Mesosphere Explorer (SME) UV Spectrometer, and SME 1.27 Micron Airglow. The improved version of the reference model uses reprocessed AE-2 SAGE data (sunset) and extends the use of SAGE data from 1981 to the 1981-1983 time period. Comparisons are presented between the results of this ozone model and various nonsatellite measurements at different levels in the middle atmosphere.