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Sample records for air-purifying particulate respirators

  1. 42 CFR 84.170 - Non-powered air-purifying particulate respirators; description.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... that contain adequate oxygen to support life. (b) Non-powered air-purifying particulate respirators are... includes oil-based liquid particulates. (c) Non-powered air-purifying particulate respirators...

  2. Nanoparticle filtration performance of NIOSH-certified particulate air-purifying filtering facepiece respirators: evaluation by light scattering photometric and particle number-based test methods.

    PubMed

    Rengasamy, Samy; Eimer, Benjamin C

    2012-01-01

    National Institute for Occupational Safety and Health (NIOSH) certification test methods employ charge neutralized NaCl or dioctyl phthalate (DOP) aerosols to measure filter penetration levels of air-purifying particulate respirators photometrically using a TSI 8130 automated filter tester at 85 L/min. A previous study in our laboratory found that widely different filter penetration levels were measured for nanoparticles depending on whether a particle number (count)-based detector or a photometric detector was used. The purpose of this study was to better understand the influence of key test parameters, including filter media type, challenge aerosol size range, and detector system. Initial penetration levels for 17 models of NIOSH-approved N-, R-, and P-series filtering facepiece respirators were measured using the TSI 8130 photometric method and compared with the particle number-based penetration (obtained using two ultrafine condensation particle counters) for the same challenge aerosols generated by the TSI 8130. In general, the penetration obtained by the photometric method was less than the penetration obtained with the number-based method. Filter penetration was also measured for ambient room aerosols. Penetration measured by the TSI 8130 photometric method was lower than the number-based ambient aerosol penetration values. Number-based monodisperse NaCl aerosol penetration measurements showed that the most penetrating particle size was in the 50 nm range for all respirator models tested, with the exception of one model at ~200 nm size. Respirator models containing electrostatic filter media also showed lower penetration values with the TSI 8130 photometric method than the number-based penetration obtained for the most penetrating monodisperse particles. Results suggest that to provide a more challenging respirator filter test method than what is currently used for respirators containing electrostatic media, the test method should utilize a sufficient number

  3. 42 CFR 84.254 - Powered air-purifying respirators; requirements and tests.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... air-purifying respirators prescribed in subpart L of this part are applicable to vinyl chloride... use with powered air-purifying respirators for entry into and escape from vinyl chloride atmospheres... of 25 ppm vinyl chloride monomer at a total flow rate of 115 liters per minute for...

  4. Using Air-Purifying Respirators. Module 9. Vocational Education Training in Environmental Health Sciences.

    ERIC Educational Resources Information Center

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on using air-purifying respirators. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) describing how air flows through an…

  5. Speech intelligibility while wearing full-facepiece air-purifying respirators.

    PubMed

    Coyne, Karen M; Barker, Daniel J

    2014-01-01

    Intelligible speech communication while wearing air-purifying respirators is critical for law enforcement officers, particularly when they are communicating with each other or the public. The National Institute for Occupational Safety and Health (NIOSH) requires a 70% overall performance rating to pass speech intelligibility certification for commercial chemical, biological, radiological, and nuclear air-purifying respirators. However, the speech intelligibility of certified respirators is not reported and the impact on operational performance is unknown. The objective of this effort was to assess the speech intelligibility of 12 certified air-purifying respirators and to predict their impact on operational performance. The NIOSH respirator certification standard testing procedures were followed. Regression equations were fit to data from studies that examined the impact of degraded speech intelligibility on operational performance of simple and complex missions. The impact of the tested respirators on operational performance was estimated from these equations. Performance ratings observed for each respirator were: MSA Millennium (90%), 3M FR-M40 (88%), MSA Ultra Elite (87%), Scott M110 (86%), North 5400 (85%), Scott M120 (85%), Avon C50 (84%), Avon FM12 (84%), Survivair Optifit (81%), Drager CDR 4500 (81%), Peltor-AOSafety M-TAC (79%), and 3M FR-7800B (78%). The Millennium and FR-M40 had statistically significantly higher scores than the FR-7800B. The Millennium also scored significantly higher than the M-TAC. All of the tested respirators were predicted to have little impact on simple and complex mission performance times and on simple mission success rate. However, the regression equations showed that 75% of missions that require complex communications would be completed while wearing the Millennium, FR-M40, or Ultra Elite but that only 60% would be completed successfully while wearing the FR-7800B. These results suggest that some certified respirators may have

  6. Workplace performance of a loose-fitting powered air purifying respirator during nanoparticle synthesis

    NASA Astrophysics Data System (ADS)

    Koivisto, Antti J.; Aromaa, Mikko; Koponen, Ismo K.; Fransman, Wouter; Jensen, Keld A.; Mäkelä, Jyrki M.; Hämeri, Kaarle J.

    2015-04-01

    Nanoparticle (particles with diameter ≤100 nm) exposure is recognized as a potentially harmful size fraction for pulmonary particle exposure. During nanoparticle synthesis, the number concentrations in the process room may exceed 10 × 106 cm-3. During such conditions, it is essential that the occupants in the room wear highly reliable high-performance respirators to prevent inhalation exposure. Here we have studied the in-use program protection factor (PPF) of loose-fitting powered air purifying respirators, while workers were coating components with TiO2 or Cu x O y nanoparticles under a hood using a liquid flame spray process. The PPF was measured using condensation particle counters, an electrical low pressure impactor, and diffusion chargers. The room particle concentrations varied from 4 × 106 to 40 × 106 cm-3, and the count median aerodynamic diameter ranged from 32 to 180 nm. Concentrations inside the respirator varied from 0.7 to 7.2 cm-3. However, on average, tidal breathing was assumed to increase the respirator concentration by 2.3 cm-3. The derived PPF exceeded 1.1 × 106, which is more than 40 × 103 times the respirator assigned protection factor. We were unable to measure clear differences in the PPF of respirators with old and new filters, among two male and one female user, or assess most penetrating particle size. This study shows that the loose-fitting powered air purifying respirator provides very efficient protection against nanoparticle inhalation exposure if used properly.

  7. Speech intelligibility assessment of protective facemasks and air-purifying respirators.

    PubMed

    Palmiero, Andrew J; Symons, Daniel; Morgan, Judge W; Shaffer, Ronald E

    2016-12-01

    Speech Intelligibility (SI) is the perceived quality of sound transmission. In healthcare settings, the ability to communicate clearly with coworkers, patients, etc., is crucial to quality patient care and safety. The objectives of this study were to: (1) assess the suitability of the Speech Transmission Index (STI) methods for testing reusable and disposable facial and respiratory personal protective equipment (protective facemasks [PF], N95 filtering facepiece respirators [N95 FFR], and elastomeric half-mask air-purifying respirators [EAPR]) commonly worn by healthcare workers; (2) quantify STI levels of these devices; and (3) contribute to the scientific body of knowledge in the area of SI. SI was assessed using the STI under two experimental conditions: (1) a modified version of the National Fire Protection Association 1981 Supplementary Voice Communications System Performance Test at a Signal to Noise Ratio (SNR) of -15 (66 dBA) and (2) STI measurements utilizing a range of modified pink noise levels (52.5 dBA (-2 SNR) - 72.5 dBA (+7 SNR)) in 5.0 dBA increments. The PF models (Kimberly Clark 49214 and 3 M 1818) had the least effect on SI interference, typically deviating from the STI baseline (no-mask condition) by 3% and 4% STI, respectively. The N95FFR (3 M 1870, 3 M 1860) had more effect on SI interference, typically differing from baseline by 13% and 17%, respectively, for models tested. The EAPR models (Scott Xcel and North 5500) had the most significant impact on SI, differing from baseline by 42% for models tested. This data offers insight into the performance of these apparatus with respect to STI and may serve as a reference point for future respirator design considerations, standards development, testing and certification activities.

  8. SPEECH INTELLIGIBILITY ASSESSMENT OF PROTECTIVE FACEMASKS AND AIR-PURIFYING RESPIRATORS

    PubMed Central

    Palmiero, Andrew J.; Symons, Daniel; Morgan, Judge W.; Shaffer, Ronald E.

    2016-01-01

    Speech Intelligibility (SI) is the perceived quality of sound transmission. In healthcare settings, the ability to communicate clearly with coworkers, patients, etc. is crucial to quality patient care and safety. The objectives of this study were to 1) assess the suitability of the Speech Transmission Index (STI) methods for testing reusable and disposable facial and respiratory personal protective equipment (protective facemasks [PF], N95 filtering facepiece respirators [N95 FFR], and elastomeric half-mask air-purifying respirators [EAPR]) commonly worn by healthcare workers, 2) quantify STI levels of these devices, and 3) contribute to the scientific body of knowledge in the area of SI. SI was assessed using the STI under two experimental conditions: 1) a modified version of the National Fire Protection Association 1981 Supplementary Voice Communications System Performance Test at a Signal to Noise Ratio (SNR) of −15 (66 dBA) and 2) STI measurements utilizing a range of modified pink noise levels (52.5 dBA (−2 SNR) − 72.5 dBA (+7 SNR)) in 5.0 dBA increments. The PF models (Kimberly Clark 49214 and 3M 1818) had the least effect on SI interference, typically deviating from the STI baseline (no-mask condition) by 3% and 4% STI, respectively. The N95FFR (3M 1870, 3M 1860) had more effect on SI interference, typically differing from baseline by 13% and 17%, respectively for models tested. The EAPR models (Scott Xcel and North 5500) had the most significant impact on SI, differing from baseline by 42% for models tested. This data offers insight into the performance of these apparatus with respect to STI and may serve as a reference point for future respirator design considerations, standards development, testing and certification activities. PMID:27362358

  9. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... sodium chloride or equivalent solid aerosol at 25 ±5 °C and relative humidity of 30 ±10 percent that has... further decrease in efficiency. (g) The sodium chloride test aerosol shall have a particle size...-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid...

  10. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... sodium chloride or equivalent solid aerosol at 25 ±5 °C and relative humidity of 30 ±10 percent that has... further decrease in efficiency. (g) The sodium chloride test aerosol shall have a particle size...-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid...

  11. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... sodium chloride or equivalent solid aerosol at 25 ±5 °C and relative humidity of 30 ±10 percent that has... further decrease in efficiency. (g) The sodium chloride test aerosol shall have a particle size...-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid...

  12. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... sodium chloride or equivalent solid aerosol at 25 ±5 °C and relative humidity of 30 ±10 percent that has... further decrease in efficiency. (g) The sodium chloride test aerosol shall have a particle size...-purifying particulate respirator model shall be tested for filter efficiency against: (1) A solid...

  13. Workplace protection factor measurements on powered air-purifying respirators at a secondary lead smelter--test protocol.

    PubMed

    Myers, W R; Peach, M J; Allender, J

    1984-04-01

    A study was conducted at a secondary smelter to evaluate the workplace performance of the 3M Model W-344 and Racal Model AH3 powered air-purifying respirators ( PAPR ) equipped with helmets and high efficiency filters. The research protocol developed for obtaining leakage measurements in the field provides for proper respirator fitting, use, wear, maintenance and worker supervision, all of which are problems commonly associated with data acquisition when field testing respirators. The protocol proved to be very workable, even though it required extensive worker and equipment monitoring. Based upon the successful implementation of this protocol, the performance of these PAPRs should be indicative of their best performance under the workplace conditions experienced in this study. This research protocol is proposed as a model for conducting field studies on other types of respirators as well as the basis on which to develop new and improved field test procedures. The results of one such study are presented in a comparison paper.

  14. Workplace protection factor measurements on powered air-purifying respirators at a secondary lead smelter - test protocol

    SciTech Connect

    Myers, W.R.; Peach, M.J. III; Alldender, J.

    1984-04-01

    A study was conducted at a secondary smelter to evaluate the workplace performance of the 3M Model W-344 and Racal Model AH3 powered air-purifying respirators (PAPR) equipped with helmets and high efficiency filters. The research protocol developed for obtaining leakage measurements in the field provides for proper respirator fitting, use, wear, maintenance and worker supervision, all of which are problems commonly associated with data acquisition when field testing respirators. The protocol proved to be very workable, even though it required extensive worker and equipment monitoring. Based upon the successful implementation of this protocol, the performance of these PAPRs should be indicative of their best performance under the workplace conditions experienced in this study. This research protocol is proposed as a model for conducting field studies on other types of respirators as well as the basis on which to develop new and improved field test procedures. The results of one such study are presented in a comparison paper.

  15. Recommended Test Methods and Pass/Fail Criteria for a Respirator Fit Capability Test of Half-Mask Air-Purifying Respirators.

    PubMed

    Zhuang, Ziqing; Bergman, Michael; Lei, Zhipeng; Niezgoda, George; Shaffer, Ronald

    2017-02-25

    This study assessed key test parameters and pass/fail criteria options for developing a respirator fit capability (RFC) test for half-mask air-purifying particulate respirators. Using a 25-subject test panel, benchmark RFC data were collected for 101 National Institute for Occupational Safety and Health-certified respirator models. These models were further grouped into 61 one-, two- or three-size families. Fit testing was done using a PortaCount® Plus with N95-Companion accessory and an Occupational Safety and Health Administration-accepted quantitative fit test protocol. Three repeated tests (donnings) per subject/respirator model combination were performed. The panel passing rate (PPR) (number or percentage of the 25-subject panel achieving acceptable fit) was determined for each model using five different alternative criteria for determining acceptable fit. When the 101 models are evaluated individually (i.e., not grouped by families), the percentages of models capable of fitting > 75% (19/25 subjects) of the panel were 29% and 32% for subjects achieving a fit factor ≥ 100 for at least one of the first two donnings and at least one of three donnings, respectively. When the models are evaluated grouped into families and using > 75% of panel subjects achieving a fit factor ≥ 100 for at least one of two donnings as the PPR pass/fail criterion, 48% of all models can pass. When > 50% (13/25 subjects) of panel subjects was the PPR criterion, the percentage of passing models increased to 70%. Testing respirators grouped into families and evaluating the first two donnings for each of two respirator sizes provided the best balance between meeting end user expectations and creating a performance bar for manufacturers. Specifying the test criterion for a subject obtaining acceptable fit as achieving a fit factor ≥ 100 on at least one out of the two donnings is reasonable because a majority of existing respirator families can achieve an PPR of > 50% using this

  16. Summary report, California Department of Forestry and Fire Protection evaluation of full-face air-purifying respirators for wildland fire fighting use

    SciTech Connect

    Beason, D.G.; Johnson, J.S.; Foote, K.L.; Weaver, W.A.

    1996-02-01

    Wildland fire suppression personnel employed by the CDF do not currently have the equipment to protect themselves from the short-term acute affects of smoke from wildland fires. In addition, no regulations exist that specify appropriate respiratory protection and the current air-purifying respirator technology and carbon monoxide monitoring has not been adapted to fit wildland fire suppression requirements. This three-year limited study evaluated the ability of wildland fire fighters to perform their normal job function while wearing full-face air-purifying respirators. In the first two years of this study we designed, developed and field tested a prototype ``smart`` air-purifying respirator which incorporated a real-time carbon monoxide monitor into a commercial full-face respirator.` Data on carbon monoxide exposure while fighting wildland fires was collected. During the third year of this study we evaluated eight different commercially available full-face air-purifying respirators equipped with a variety of cartridges. Apparatus to aid the fire fighter in carrying the respirator and carbon monoxide personal monitor was designed and fabricated. A smoke exposure test method was developed and a laboratory study on the penetration of smoke through respirator cartridges was conducted.

  17. Workplace protection factor measurements on powered air-purifying respirators at a secondary lead smelter: results and discussion.

    PubMed

    Myers, W R; Peach, M J; Cutright, K; Iskander, W

    1984-10-01

    A study was conducted at a secondary lead smelter to evaluate the workplace performance of the 3M W-344 and Racal AH3 powered air-purifying respirators equipped with helmets and high efficiency filters. The research protocol developed for the study has been described in a companion paper. The results of the study indicate that the mean lead concentrations, measured inside the facepiece of both PAPRs, were significantly less than the OSHA lead exposure limit of 50 micrograms/m3. The means of the workplace protection factor measurements on both PAPRs were significantly less than the PAPR selection guide protection factor classification of 1000. Correlation analysis of preshift quantitative fit factors and corresponding workplace protection factors indicated no linear association between these two measures of performance. This finding suggests that for PAPRs equipped with helmets and high efficiency filters quantitative fit factors as presently determined are not indicative of the workplace protection which the respirators provide. Since the PAPR protection factor classification of 1000 was originally based on quantitative fit factors, the lack of a demonstrated association between quantitative fit factors and workplace protection as found in this study may explain why their performance was significantly less than expected.

  18. Kinetic analysis of competition between aerosol particle removal and generation by ionization air purifiers.

    PubMed

    Alshawa, Ahmad; Russell, Ashley R; Nizkorodov, Sergey A

    2007-04-01

    Ionization air purifiers are increasingly used to remove aerosol particles from indoor air. However, certain ionization air purifiers also emit ozone. Reactions between the emitted ozone and unsaturated volatile organic compounds (VOC) commonly found in indoor air produce additional respirable aerosol particles in the ultrafine (<0.1 microm) and fine (<2.5 microm) size domains. A simple kinetic model is used to analyze the competition between the removal and generation of particulate matter by ionization air purifiers under conditions of a typical residential building. This model predicts that certain widely used ionization air purifiers may actually increase the mass concentration of fine and ultrafine particulates in the presence of common unsaturated VOC, such as limonene contained in many household cleaning products. This prediction is supported by an explicit observation of ultrafine particle nucleation events caused by the addition of D-limonene to a ventilated office room equipped with a common ionization air purifier.

  19. Effects of a powered air-purifying respirator intervention on indium exposure reduction and indium related biomarkers among ITO sputter target manufacturing workers.

    PubMed

    Liu, Hung-Hsin; Chen, Chang-Yuh; Lan, Cheng-Hang; Chang, Cheng-Ping; Peng, Chiung-Yu

    2016-01-01

    This study aimed to evaluate the efficacy of powered air-purifying respirators (PAPRs) worn by the workers, and to investigate the effect of this application on exposure and preclinical effects in terms of workplace measuring and biomarker monitoring in ITO sputter target manufacturing plants and workers, respectively. Fifty-four workers were recruited and investigated from 2010-2012, during which PAPRs were provided to on-site workers in September 2011. Each worker completed questionnaires and provided blood and urine samples for analysis of biomarkers of indium exposure and preclinical effects. Area and personal indium air samples were randomly collected from selected worksites and from participants. The penetration percentage of the respirator (concentration inside respirator divided by concentration outside respirator) was 6.6%. Some biomarkers, such as S-In, SOD, GPx, GST, MDA, and TMOM, reflected the decrease in exposure and showed lower levels, after implementation of PAPRs. This study is the first to investigate the efficacy of PAPRs for reducing indium exposure. The measurement results clearly showed that the implementation of PAPRs reduces levels of indium-related biomarkers. These findings have practical applications for minimizing occupational exposure to indium and for managing the health of workers exposed to indium.

  20. Performance of an improperly sized and stretched-out loose-fitting powered air-purifying respirator: Manikin-based study.

    PubMed

    Gao, Shuang; McKay, Roy T; Yermakov, Michael; Kim, Jinyong; Reponen, Tiina; He, Xinjian; Kimura, Kazushi; Grinshpun, Sergey A

    2016-01-01

    The objective of this study was to investigate the protection level offered by a Powered Air-Purifying Respirator (PAPR) equipped with an improperly sized or stretched-out loose-fitting facepiece using constant and cyclic flow conditions. Improperly sized PAPR facepieces of two models as well as a stretched-out facepiece were tested. These facepieces were examined in two versions: with and without exhaust holes. Loose-fitting facepieces (size "large") were donned on a small manikin headform and challenged with sodium chloride (NaCl) aerosol particles in an exposure chamber. Four cyclic flows with mean inspiratory flows (MIFs) of 30, 55, 85, and 135 L/min were applied using an electromechanical Breathing Recording and Simulation System (BRSS). The manikin Fit Factor (mFF) was determined as the ratio of aerosol concentrations outside (Cout) to inside (Cin) of the facepiece, measured with a P-Trak condensation particle counter (CPC). Results showed that the mFF decreased exponentially with increasing MIF. The mFF values of the stretched-out facepiece were significantly lower than those obtained for the undamaged ones. Facepiece type and MIF were found to significantly affect the performance of the loose-fitting PAPR. The effect of the exhaust holes was less pronounced and depended on the facepiece type. It was concluded that an improperly sized facepiece might potentially offer relatively low protection (mFF < 250) at high to strenuous workloads. The testing was also performed at a constant inhalation flow to explore the mechanism of the particle-facepiece interaction. Results obtained with cyclic flow pattern were consistent with the data generated when testing the loose-fitting PAPR under constant flow conditions. The time-weighted average values of mFF calculated from the measurements conducted under the constant flow regime were capable of predicting the protection under cyclic flow regime. The findings suggest that program administrators need to equip employees

  1. Natural Air Purifier

    NASA Technical Reports Server (NTRS)

    1993-01-01

    NASA environmental research has led to a plant-based air filtering system. Dr. B.C. Wolverton, a former NASA engineer who developed a biological filtering system for space life support, served as a consultant to Terra Firma Environmental. The company is marketing the BioFilter, a natural air purifier that combines activated carbon and other filter media with living plants and microorganisms. The filter material traps and holds indoor pollutants; plant roots and microorganisms then convert the pollutants into food for the plant. Most non-flowering house plants will work. After pollutants have been removed, the cleansed air is returned to the room through slits in the planter. Terra Firma is currently developing a filter that will also disinfect the air.

  2. 78 FR 69361 - Development of Inward Leakage Standards for Half-Mask Air-Purifying Particulate Respirators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-19

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HEALTH AND.... ADDRESSES: You may submit comments by either of the following methods: Federal eRulemaking Portal: http://www.regulations.gov . Follow the instructions for submitting comments. Mail: NIOSH Docket...

  3. 78 FR 54432 - Development of Inward Leakage Standards for Half-Mask Air-Purifying Particulate Respirators

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-04

    ... requirement were carefully considered by NIOSH leadership, researchers, standard and policy developers, and..., the sizing basis, and the representation of male and female test subjects. What pass/fail criteria...

  4. 42 CFR 84.174 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.174... Air-Purifying Particulate Respirators § 84.174 Respirator containers; minimum requirements. (a) Except..., durable container bearing markings which show the applicant's name, the type of respirator it...

  5. Home Air Purifiers Eradicate Harmful Pathogens

    NASA Technical Reports Server (NTRS)

    2014-01-01

    Marshall Space Flight Center funded the University of Madison-Wisconsin to develop ethylene scrubbers to keep produce fresh in space. Akida Holdings of Jacksonville, Florida, licensed the technology and developed Airocide, an air purifier that can kill airborne pathogens. Previously designed for industrial spaces, there is now a specially designed unit for home use.

  6. Identifying dominant sources of respirable suspended particulates in Guangzhou, China

    SciTech Connect

    Song, Y.; Dai, W.; Wang, X.S.; Cui, M.M.; Su, H.; Xie, S.D.; Zhang, Y.H.

    2008-09-15

    Respirable suspended particulates (RSP, i.e., particles with an aerodynamic diameter of 10 {mu} m or less) were measured in 2004 and 2005 at seven sites in the rapidly developing Guangzhou area of China. The average RSP concentration was 126 {mu} g m{sup -3}, a high level that could be very harmful to human health. The chemical species composition of the RSP, including organic and elemental carbon, water-soluble ions, and elemental compositions, was also analyzed. The organics and sulfate may be the major components of RSP mass concentrations. Positive matrix factorization (PMF) was used to identify the sources of RSP as secondary sulfates (32%), secondary nitrates (6%), biomass burning (15%), coal fly ash/cement (18%), sea salt (3%), crustal dust (5%), vehicle exhaust (6%), and coal-fired power plants (3%). Reducing coal combustion and controlling vehicle emissions would alleviate RSP pollution, as most of the precursors were components of coal burning emissions and vehicular exhaust.

  7. Impact assessment of respirable suspended particulate matter from diesel generator sets used for pumping station.

    PubMed

    Talwar, B; Pipalatkar, P; Gajghate, D G; Nema, P

    2010-10-01

    Prediction of respirable suspended particulate matter impacts of diesel generator sets used for pumping station has been made using meteorological data, information on stack characteristics and emission rate, baseline ambient particulate matter and Industrial Source Complex Short Term (ISCST-3) model. It is observed that particulate matter emission from pumping station-S workplace diesel generator sets ranged from 2.4 to 436.5 mg Nm⁻³ and while at pumping station-C, it ranged from 23.2 to 186.5 mg Nm⁻³. The predicted and ambient respirable suspended particulate matter concentrations are below the national air quality standard for respirable suspended particulate matter in a mixed industrial area. Metals contents in respirable suspended particulate matter indicate the origin of crustal and mobile sources. Therefore, the impact of diesel generator sets used for pumping of crude oil on local air quality would be acceptable.

  8. Respirator selection for clandestine methamphetamine laboratory investigation.

    PubMed

    Nelson, Gary O; Bronder, Gregory D; Larson, Scott A; Parker, Jay A; Metzler, Richard W

    2012-01-01

    First responders to illicit drug labs may not always have SCBA protection available. Air-purifying respirators using organic vapor cartridges with P-100 filters may not be sufficient. It would be better to use a NIOSH-approved CBRN respirator with its required multi-purpose cartridge system, which includes a P-100 filter. This would remove all the primary drug lab contaminants—organic vapors, acid gases, ammonia, phosphine, iodine, and airborne meth particulates. To assure the proper selection and use of a respirator, it is recommended that the contaminants present be identified and quantified and the OSHA 29 CFR 1910.134 respirator protection program requirements followed.

  9. An Experiment with Air Purifiers in Delhi during Winter 2015-2016.

    PubMed

    Vyas, Sangita; Srivastav, Nikhil; Spears, Dean

    2016-01-01

    Particulate pollution has important consequences for human health, and is an issue of global concern. Outdoor air pollution has become a cause for alarm in India in particular because recent data suggest that ambient pollution levels in Indian cities are some of the highest in the world. We study the number of particles between 0.5μm and 2.5μm indoors while using affordable air purifiers in the highly polluted city of Delhi. Though substantial reductions in indoor number concentrations are observed during air purifier use, indoor air quality while using an air purifier is frequently worse than in cities with moderate pollution, and often worse than levels observed even in polluted cities. When outdoor pollution levels are higher, on average, indoor pollution levels while using an air purifier are also higher. Moreover, the ratio of indoor air quality during air purifier use to two comparison measures of air quality without an air purifier are also positively correlated with outdoor pollution levels, suggesting that as ambient air quality worsens there are diminishing returns to improvements in indoor air quality during air purifier use. The findings of this study indicate that although the most affordable air purifiers currently available are associated with significant improvements in the indoor environment, they are not a replacement for public action in regions like Delhi. Although private solutions may serve as a stopgap, reducing ambient air pollution must be a public health and policy priority in any region where air pollution is as high as Delhi's during the winter.

  10. An Experiment with Air Purifiers in Delhi during Winter 2015-2016

    PubMed Central

    Vyas, Sangita

    2016-01-01

    Particulate pollution has important consequences for human health, and is an issue of global concern. Outdoor air pollution has become a cause for alarm in India in particular because recent data suggest that ambient pollution levels in Indian cities are some of the highest in the world. We study the number of particles between 0.5μm and 2.5μm indoors while using affordable air purifiers in the highly polluted city of Delhi. Though substantial reductions in indoor number concentrations are observed during air purifier use, indoor air quality while using an air purifier is frequently worse than in cities with moderate pollution, and often worse than levels observed even in polluted cities. When outdoor pollution levels are higher, on average, indoor pollution levels while using an air purifier are also higher. Moreover, the ratio of indoor air quality during air purifier use to two comparison measures of air quality without an air purifier are also positively correlated with outdoor pollution levels, suggesting that as ambient air quality worsens there are diminishing returns to improvements in indoor air quality during air purifier use. The findings of this study indicate that although the most affordable air purifiers currently available are associated with significant improvements in the indoor environment, they are not a replacement for public action in regions like Delhi. Although private solutions may serve as a stopgap, reducing ambient air pollution must be a public health and policy priority in any region where air pollution is as high as Delhi’s during the winter. PMID:27978542

  11. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Miscellaneous Devices § 880.6500 Medical ultraviolet air purifier. (a) Identification. A medical ultraviolet air purifier is a device intended for medical purposes that is used to destroy bacteria in the air by...

  12. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Miscellaneous Devices § 880.6500 Medical ultraviolet air purifier. (a) Identification. A medical ultraviolet air purifier is a device intended for medical purposes that is used to destroy bacteria in the air by...

  13. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Miscellaneous Devices § 880.6500 Medical ultraviolet air purifier. (a) Identification. A medical ultraviolet air purifier is a device intended for medical purposes that is used to destroy bacteria in the air by...

  14. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Miscellaneous Devices § 880.6500 Medical ultraviolet air purifier. (a) Identification. A medical ultraviolet air purifier is a device intended for medical purposes that is used to destroy bacteria in the air by...

  15. Air Purifiers Eliminate Pathogens, Preserve Food

    NASA Technical Reports Server (NTRS)

    2009-01-01

    NASA-funded researchers produced an ethylene reduction device for a plant growth unit. KES Science & Technology Inc., a Kennesaw, Georgia-based company specializing in sustaining perishable foods, licensed the ethylene scrubbing technology. KES partnered with Akida Holdings, of Jacksonville, Florida, which now markets the NASA-developed technology as AiroCide. According to the company, it is the only air purifier that completely destroys airborne bacteria, mold, fungi, mycotoxins, viruses, volatile organic compounds (like ethylene), and odors. What?s more, the devices have no filters that need changing and produce no harmful byproducts, such as the ozone created by some filtration systems.

  16. Exercise Limitation Imposed by an Approved Air Purifying Respirator (APR)

    DTIC Science & Technology

    2010-05-01

    mentioned that they did not have enough time to inhale, that inspiratory muscles were fatigued, that they got out of rhythm with their breathing and...frequency, tidal volume, respiratory duty cycle, mask pressure, resistive effort (WOB/VT), minute ventilation (VE), peak inspiratory flow (Vi peak), rate...and VO2 at end running endurance decreased 15 to 18%. Because required inspiratory pressures from laminar and turbulent flow were so high at the

  17. Ozone emissions from a "personal air purifier".

    PubMed

    Phillips, T J; Bloudoff, D P; Jenkins, P L; Stroud, K R

    1999-01-01

    Ozone emissions were measured above a "personal air purifier" (PAP) designed to be worn on a lapel, shirt pocket, or neck strap. The device is being marketed as a negative ion generator that purifies the air. However, it also produces ozone within the person's immediate breathing zone. In order to assess worst-case potential human exposure to ozone at the mouth and nose, we measured ozone concentrations in separate tests at 1, 3, 5, and 6 in. above each of two PAPs in a closed office. One PAP was new, and one had been used slightly for 3 months. Temperature, relative humidity, atmospheric pressure, room ozone concentration, and outdoor ozone concentration also were measured concurrently during the tests. Average ozone levels measured directly above the individual PAPs ranged from 65-71 ppb at 6 in. above the device to 268-389 ppb at 1 in. above the device. Ozone emission rates from the PAPs were estimated to be 1.7-1.9 microg/minute. When house dust was sprinkled on the top grid of the PAPs, one showed an initial peak of 522 ppb ozone at 1 in., and then returned to the 200-400 ppb range. Room ozone levels increased by only 0-5 ppb during the tests. Even when two PAPs were left operating over a weekend, room ozone levels did not noticeably increase beyond background room ozone levels. These results indicate that this "PAP," even without significant background ozone, can potentially elevate the user's exposures to ozone levels greater than the health-based air quality standards for outdoor air in California (0.09 ppm, 1-hour average) and the United States (0.08 ppm, 8-hour average).

  18. 21 CFR 880.6500 - Medical ultraviolet air purifier.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Medical ultraviolet air purifier. 880.6500 Section... (CONTINUED) MEDICAL DEVICES GENERAL HOSPITAL AND PERSONAL USE DEVICES General Hospital and Personal Use Miscellaneous Devices § 880.6500 Medical ultraviolet air purifier. (a) Identification. A medical ultraviolet...

  19. Cardiovascular Benefits of Wearing Particulate-Filtering Respirators: A Randomized Crossover Trial

    PubMed Central

    Shi, Jingjin; Lin, Zhijing; Chen, Renjie; Wang, Cuicui; Yang, Changyuan; Cai, Jing; Lin, Jingyu; Xu, Xiaohui; Ross, Jennifer A.; Zhao, Zhuohui; Kan, Haidong

    2016-01-01

    Background: Practical approaches to protect individuals from ambient particulate matter (PM) are urgently needed in developing countries. Evidence on the health benefits of wearing particulate-filtering respirators is limited. Objectives: We evaluated the short-term cardiovascular health effects of wearing respirators in China. Methods: A randomized crossover trial was performed in 24 healthy young adults in Shanghai, China in 2014. The subjects were randomized into two groups and wore particulate-filtering respirators for 48 hr alternating with a 3-week washout interval. Heart rate variability (HRV) and ambulatory blood pressure (BP) were continuously monitored during the 2nd 24 hr in each intervention. Circulating biomarkers were measured at the end of each intervention. Linear mixed-effect models were applied to evaluate the effects of wearing respirators on health outcomes. Results: During the intervention periods, the mean daily average concentration of PM with an aerodynamic diameter < 2.5 μm (PM2.5) was 74.2 μg/m3. Compared with the absence of respirators, wearing respirators was associated with a decrease of 2.7 mmHg [95% confidence interval (CI): 0.1, 5.2 mmHg] in systolic BP and increases of HRV parameters, including 12.5% (95% CI: 3.8%, 21.2%) in high frequency (HF) power, 10.9% (95% CI: 1.8%, 20.0%) in the root mean square of the successive differences, and 22.1% (95% CI: 3.6%, 40.7%) in the percentage of normal RR intervals with duration > 50 msec different from the previous normal RR interval (pNN50). The presence of respirators was also associated with a decrease of 7.8% (95% CI: 3.5%, 12.1%) in the ratio of low frequency (LF)/HF power. Conclusions: Short-term wearing of particulate-filtering respirators may produce cardiovascular benefits by improving autonomic nervous function and reducing BP. Citation: Shi J, Lin Z, Chen R, Wang C, Yang C, Cai J, Lin J, Xu X, Ross JA, Zhao Z, Kan H. 2017. Cardiovascular benefits of wearing particulate

  20. Efficiency of Respirator Filter Media against Diesel Particulate Matter: A Comparison Study Using Two Diesel Particulate Sources.

    PubMed

    Burton, Kerrie A; Whitelaw, Jane L; Jones, Alison L; Davies, Brian

    2016-07-01

    Diesel engines have been a mainstay within many industries since the early 1900s. Exposure to diesel particulate matter (DPM) is a major issue in many industrial workplaces given the potential for serious health impacts to exposed workers; including the potential for lung cancer and adverse irritant and cardiovascular effects. Personal respiratory protective devices are an accepted safety measure to mitigate worker exposure against the potentially damaging health impacts of DPM. To be protective, they need to act as effective filters against carbon and other particulates. In Australia, the filtering efficiency of respiratory protective devices is determined by challenging test filter media with aerosolised sodium chloride to determine penetration at designated flow rates. The methodology outlined in AS/NZS1716 (Standards Australia International Ltd and Standards New Zealand 2012. Respiratory protective devices. Sydney/Wellington: SAI Global Limited/Standards New Zealand) does not account for the differences between characteristics of workplace contaminants like DPM and sodium chloride such as structure, composition, and particle size. This study examined filtering efficiency for three commonly used AS/NZS certified respirator filter models, challenging them with two types of diesel emissions; those from a diesel generator and a diesel engine. Penetration through the filter media of elemental carbon (EC), total carbon (TC), and total suspended particulate (TSP) was calculated. Results indicate that filtering efficiency assumed by P2 certification in Australia was achieved for two of the three respirator models for DPM generated using the small diesel generator, whilst when the larger diesel engine was used, filtering efficiency requirements were met for all three filter models. These results suggest that the testing methodology specified for certification of personal respiratory protective devices by Standards Australia may not ensure adequate protection for

  1. Respirable particulate monitoring with remote sensors. (Public health ecology: Air pollution)

    NASA Technical Reports Server (NTRS)

    Severs, R. K.

    1974-01-01

    The feasibility of monitoring atmospheric aerosols in the respirable range from air or space platforms was studied. Secondary reflectance targets were located in the industrial area and near Galveston Bay. Multichannel remote sensor data were utilized to calculate the aerosol extinction coefficient and thus determine the aerosol size distribution. Houston Texas air sampling network high volume data were utilized to generate computer isopleth maps of suspended particulates and to establish the mass loading of the atmosphere. In addition, a five channel nephelometer and a multistage particulate air sampler were used to collect data. The extinction coefficient determined from remote sensor data proved more representative of wide areal phenomena than that calculated from on site measurements. It was also demonstrated that a significant reduction in the standard deviation of the extinction coefficient could be achieved by reducing the bandwidths used in remote sensor.

  2. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  3. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  4. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  5. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  6. Workplace field testing of the pressure drop of particulate respirators using welding fumes.

    PubMed

    Cho, Hyun-Woo; Yoon, Chung-Sik

    2012-10-01

    In a previous study, we concluded that respirator testing with a sodium chloride aerosol gave a conservative estimate of filter penetration for welding fume aerosols. A rapid increase in the pressure drop (PD) of some respirators was observed as fumes accumulated on the filters. The present study evaluated particulate respirator PD based on workplace field tests. A field PD tester was designed and validated using the TSI 8130 Automatic Filter Tester, designed in compliance with National Institute for Occupational and Safety and Health regulation 42 CFR part 84. Three models (two replaceable dual-type filters and one replaceable single-type filter) were evaluated against CO(2) gas arc welding on mild steel in confined booths in the workplace. Field tests were performed under four airborne concentrations (27.5, 15.4, 7.9, and 2.1 mg m(-3)). The mass concentration was measured by the gravimetric method, and number concentration was monitored using P-Trak (Model 8525, TSI, USA). Additionally, photos and scanning electron microscopy-energy dispersive X-ray spectroscopy were used to visualize and analyze the composition of welding fumes trapped in the filters. The field PD tester showed no significant difference compared with the TSI tester. There was no significant difference in the initial PD between laboratory and field results. The PD increased as a function of fume load on the respirator filters for all tested models. The increasing PD trend differed by models, and PD increased rapidly at high concentrations because greater amount of fumes accumulated on the filters in a given time. The increase in PD as a function of fume load on the filters showed a similar pattern as fume load varied for a particular model, but different patterns were observed for different models. Images and elemental analyses of fumes trapped on the respirator filters showed that most welding fumes were trapped within the first layer, outer web cover, and second layer, in order, while no fumes

  7. Pulmonary toxicity screening studies in male rats with M5 respirable fibers and particulates.

    PubMed

    Warheit, David B; Webb, Thomas R; Reed, Kenneth L

    2007-09-01

    M5 fiber is a high-strength, high-performance organic fiber type that is a rigid rod material and composed of heterocyclic polymer fibers of type PIPD. The aim of this study was to evaluate the acute lung toxicity of intratracheally instilled M5 respirable fibers and particulates in rats. Using a pulmonary bioassay and bridging methodology, the acute lung toxicity of intratracheally instilled M5 particulates and that of its fibers were compared with a positive control particle type, quartz, as well as a negative control particle type, carbonyl iron particles. Moreover, the results of these instillation studies were bridged with data previously generated from inhalation studies with quartz and carbonyl iron particles, using the quartz and iron particles as the inhalation/instillation bridge material. For the bioassay experimental design, in the bronchoalveolar lavage studies, the lungs of rats were intratracheally instilled with 0.5 or 0.75 mg/kg of M5 particulate or 1 or 5 mg/kg of the following control or particle types: (1) M5 long fiber preparation, (2) silica-quartz particles, and (3) carbonyl iron particles. Phosphate-buffered saline (PBS)-instilled rats served as additional controls. Following exposures, the lungs of PBS and particle-exposed rats were assessed using bronchoalveolar lavage (BAL) fluid biomarkers, cell proliferation methods, and histopathological evaluation of lung tissue at 24 h, 1 wk, 1 mo and 3 mo post instillation exposure. The bronchoalveolar lavage results demonstrated that lung exposures to quartz particles, at both concentrations but particularly at the higher dose, produced significant increases vs. controls in pulmonary inflammation and cytotoxicity indices. Exposures to M5 particulate and M5 long fiber preparation produced transient inflammatory and cell injury effects at 24 h postexposure (pe) as well as at 24 h and 1 wk pe, respectively, but these effects were not sustained when compared to quartz-silica effects. Exposures to

  8. [Importance of air purifiers in the prevention of respiratory allergy].

    PubMed

    Sabbah, A

    2000-06-01

    Prevention of respiratory allergy and thus diminution of its prevalence consists of the application not only of preventative measures on the allergens themselves, but also on atmospheric pollutants such as NO, CO and diesel particles. These modify the allergens and increase synthesis of allergen-specific IgE. Use of air purifiers, on condition that they have HEPA or ULPA filters may contribute to reduction of allergenicity linked to pollutants and are one of the not-negligible means of protection from respiratory allergy and asthma in particular.

  9. Comparison of pressure drop and filtration efficiency of particulate respirators using welding fumes and sodium chloride.

    PubMed

    Cho, Hyun-Woo; Yoon, Chung-Sik; Lee, Jin-Ho; Lee, Seung-Joo; Viner, Andrew; Johnson, Erik W

    2011-07-01

    Respirators are used to help reduce exposure to a variety of contaminants in workplaces. Test aerosols used for certification of particulate respirators (PRs) include sodium chloride (NaCl), dioctyl phthalate, and paraffin oil. These aerosols are generally assumed to be worst case surrogates for aerosols found in the workplace. No data have been published to date on the performance of PRs with welding fumes, a hazardous aerosol that exists in real workplace settings. The aim of this study was to compare the performance of respirators and filters against a NaCl aerosol and a welding fume aerosol and determine whether or not a correlation between the two could be made. Fifteen commercial PRs and filters (seven filtering facepiece, two replaceable single-type filters, and six replaceable dual-type filters) were chosen for investigation. Four of the filtering facepiece respirators, one of the single-type filters, and all of the dual-type filters contained carbon to help reduce exposure to ozone and other vapors generated during the welding process. For the NaCl test, a modified National Institute for Occupational Safety and Health protocol was adopted for use with the TSI Model 8130 automated filter tester. For the welding fume test, welding fumes from mild steel flux-cored arcs were generated and measured with a SIBATA filter tester (AP-634A, Japan) and a manometer in the upstream and downstream sections of the test chamber. Size distributions of the two aerosols were measured using a scanning mobility particle sizer. Penetration and pressure drop were measured over a period of aerosol loading onto the respirator or filter. Photos and scanning electron microscope images of clean and exposed respirators were taken. The count median diameter (CMD) and mass median diameter (MMD) for the NaCl aerosol were smaller than the welding fumes (CMD: 74 versus 216 nm; MMD: 198 versus 528 nm, respectively). Initial penetration and peak penetration were higher with the NaCl aerosol

  10. Measurement of Ozone Emission and Particle Removal Rates from Portable Air Purifiers

    ERIC Educational Resources Information Center

    Mang, Stephen A.; Walser, Maggie L.; Nizkorodov, Sergey A.; Laux, John M.

    2009-01-01

    Portable air purifiers are popular consumer items, especially in areas with poor air quality. Unfortunately, most users of these air purifiers have minimal understanding of the factors affecting their efficiency in typical indoor settings. Emission of the air pollutant ozone (O[subscript 3]) by certain air purifiers is of particular concern. In an…

  11. Life cycle assessment comparison of photocatalytic coating and air purifier.

    PubMed

    Tichá, Marie; Žilka, Miroslav; Stieberová, Barbora; Freiberg, František

    2016-07-01

    This article presents a comparison of 2 very different options for removal of undesirable microorganisms and airborne pollutants from the indoor environment of hospitals, schools, homes, and other enclosed spaces using air purifiers and photocatalytic coatings based on nano titanium dioxide (TiO2 ). Both products were assessed by life cycle assessment (LCA) methodology from cradle-to-grave. The assessment also includes comparison of 2 different nano TiO2 production technologies, one by continuous hydrothermal synthesis and the other by a sulfate process. Results of the study showed a relatively large contribution of photocatalytic coatings to reducing the effects of selected indices in comparison with an air purifier, regardless of which nano TiO2 production method is used. Although the impacts of the sulfate process are significantly lower compared to those of hydrothermal synthesis when viewed in terms of production alone, taken in the context of the entire product life cycle, the net difference becomes less significant. The study has been elaborated within the Sustainable Hydrothermal Manufacturing of Nanomaterials (SHYMAN) project, which aims to develop competitive and sustainable continuous nanoparticle (NP) production technology based on supercritical hydrothermal synthesis. Integr Environ Assess Manag 2016;12:478-485. © 2016 SETAC.

  12. Health Outcomes of Exposure to Biological and Chemical Components of Inhalable and Respirable Particulate Matter

    PubMed Central

    Morakinyo, Oyewale Mayowa; Mokgobu, Matlou Ingrid; Mukhola, Murembiwa Stanley; Hunter, Raymond Paul

    2016-01-01

    Particulate matter (PM) is a key indicator of air pollution and a significant risk factor for adverse health outcomes in humans. PM is not a self-contained pollutant but a mixture of different compounds including chemical and biological fractions. While several reviews have focused on the chemical components of PM and associated health effects, there is a dearth of review studies that holistically examine the role of biological and chemical components of inhalable and respirable PM in disease causation. A literature search using various search engines and (or) keywords was done. Articles selected for review were chosen following predefined criteria, to extract and analyze data. The results show that the biological and chemical components of inhalable and respirable PM play a significant role in the burden of health effects attributed to PM. These health outcomes include low birth weight, emergency room visit, hospital admission, respiratory and pulmonary diseases, cardiovascular disease, cancer, non-communicable diseases, and premature death, among others. This review justifies the importance of each or synergistic effects of the biological and chemical constituents of PM on health. It also provides information that informs policy on the establishment of exposure limits for PM composition metrics rather than the existing exposure limits of the total mass of PM. This will allow for more effective management strategies for improving outdoor air quality. PMID:27314370

  13. Production of potentially hazardous respirable silica airborne particulate from the burning of sugarcane

    NASA Astrophysics Data System (ADS)

    Le Blond, Jennifer S.; Williamson, Ben J.; Horwell, Claire J.; Monro, Alex K.; Kirk, Caroline A.; Oppenheimer, Clive

    In some areas of the world where agricultural burning is practised, the airborne particles produced have been linked to respiratory disease in humans. Here, we investigate the abundance and form of silica (SiO 2) minerals found within ash and aerosol produced by the experimental burning of sugarcane. Samples of sugarcane leaf were incinerated over a range of temperatures, time scales and airflow conditions, the latter to investigate the effects of wind and updrafts during natural fires. The silica content of the residual ash (from still air simulations) was measured using an improved wet chemical methodology, described here. This indicated that the release of silica from the plant material into the atmosphere increases with increasing temperature of combustion. Airborne particulate, sampled using air-pump-filter apparatus, was characterised using scanning electron microscopy (SEM) with automated image and elemental analysis. For airborne particulate formed at 1100 °C (with airflow), 17% of the particles are in the respirable size fraction (<4 μm in diameter) and contain silica. From X-ray diffraction (XRD) analysis, a component of this silica is present as the potentially toxic polymorph cristobalite. For the residual ash, samples produced with no additional airflow were found to contain cristobalite, however none could be identified in ash formed with an airflow. It is considered likely that this is due to release of cristobalite to the atmosphere (as sampled on filters). This pilot study shows that potentially toxic particles could be released during sugarcane burning and reinforces the need for further study into the emissions and re-suspension of ash from the burning of biomass.

  14. Removal efficiency of vapour/particulate phase PAHs by using alternative protective respirators in PAHs exposure workers.

    PubMed

    Chen, Hsiu-Ling; Yang, Chien-Hung; Lin, Ming-Hsiu

    2012-06-15

    Due to the high heat environment in foundry industries, it is difficult for foundry workers to wear masks during their workday. Thus, how to prevent inhaling vapour or the particulate phase of polycyclic aromatic hydrocarbons (PAHs) is important for occupational hazard management. The present study assesses the characteristics of PAHs emission in foundry and plastic industries to evaluate the removal efficiencies of PAHs while workers use alternative personal protective equipment. The highest 1-hydroxypyrene (1-OHP) level was found for workers who used a cotton-fabric face mask (1.19 μg/g creatinine) and activated-carbon face mask (1.16 μg/g creatinine), compared to a lower level in workers who wore a surgical face mask (0.27 μg/g creatinine) and a N95 respirator (0.51 μg/g creatinine). The urinary 1-OHP in end-of-shift samples correlated to the airborne vapour phase Bapeq, but not for the particulate phase Bapeq in the foundry industry. This is probably because workers wore personal protective equipment that only removed the particulate phase PAH. The current study suggests that future work focus on developing an appropriate and comfortable respirator with high removal efficiency for ultrafine particulates and vapour phase PAHs simultaneously in PAH work environments.

  15. Quantitative exposure matrix for asphalt fume, total particulate matter, and respirable crystalline silica among roofing and asphalt manufacturing workers.

    PubMed

    Fayerweather, William E; Trumbore, David C; Johnson, Kathleen A; Niebo, Ronald W; Maxim, L Daniel

    2011-09-01

    This paper summarizes available data on worker exposures to asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica (quartz) [hereinafter RCS] over a 30-year period in Owens Corning's asphalt production and roofing manufacturing plants. For the period 1977 through 2006, the air-monitoring database contains more than 1,400 personal samples for asphalt fume (soluble fraction), 2,400 personal samples for total particulate, and 1,300 personal samples for RCS. Unique process-job categories were identified for the asphalt production and roofing shingle manufacturing plants. Quantitative exposures were tabulated by agent, process-job, and calendar period to form an exposure matrix for use in subsequent epidemiologic studies of the respiratory health of these workers. Analysis of time trends in exposure data shows substantial and statistically significant exposure reductions for asphalt fume (soluble fraction), total particulate matter, and respirable crystalline silica at Owens Corning plants. Cumulative distribution plots for the most recent sampling period (2001-2006) show that 95% of the asphalt fume (soluble fraction) measurements were less than 0.25 mg/m3; 95% of the total particulate measurements were less than 2.2 mg/m3; and 95% of the RCS measurements were less than 0.05 mg/m3. Several recommendations are offered to improve the design of future monitoring efforts.

  16. Validation and Application of the Mass Balance Model To Determine the Effectiveness of Portable Air Purifiers in Removing Ultrafine and Submicrometer Particles in an Apartment.

    PubMed

    Lee, Wan-Chen; Catalano, Paul J; Yoo, Jun Young; Park, Chan Jung; Koutrakis, Petros

    2015-08-18

    We validated the use of the mass balance model to determine the effectiveness of portable air purifiers in removing ultrafine (<0.10 μm) and submicrometer particles (0.10-0.53 μm) in an apartment. We evaluated two identical portable air purifiers, equipped with high efficiency particulate air filters, for their performance under three different air flow settings and three target air exchange rates: 0.60, 0.90, and 1.20 h(-1). We subsequently used a mixed effects model to estimate the slope between the measured and modeled effectiveness by particle size. Our study showed that effectiveness was highly particle size-dependent. For example, at the lowest target air exchange rate, it ranged from 0.33 to 0.56, 0.51 to 0.75, and 0.60 to 0.81 for the three air purifier flow settings, respectively. Our findings suggested that filtration was the dominant removal mechanism for submicrometer particles, whereas deposition could play a more important role in ultrafine particle removal. We found reasonable agreement between measured and modeled effectiveness with size-resolved slopes ranging from 1.11 ± 0.06 to 1.25 ± 0.07 (mean ± SE), except for particles <35 nm. Our study design can be applied to investigate the performances of other portable air purifiers as well as the influences of various parameters on effectiveness in different residential settings.

  17. Evaluation of particulate filtering respirators using inward leakage (IL) or total inward leakage (TIL) testing--Korean experience.

    PubMed

    Han, Don-Hee; Lee, Jinheon

    2005-10-01

    Korean certification regulation for particulate filtering respirators requires inward leakage (IL) or total inward leakage (TIL) testing according to European Standard EN 13274-1, and the standard levels of compliance are similar to those of the European Standard. This study was conducted to evaluate particulate filtering respirators being commercially used in the Korean market using an IL or TIL test and the validity of standard level in Korea. Three half masks and 10 filtering facepieces (two top class, four 1st class and four 2nd class)-a total of 13 brand name respirators-were selected for the test with panels of 10 subjects. Each subject was classified with nine facial dimension grid squares in accordance with face length and lip length. IL or TIL testing was conducted at the laboratory of the 3M Innovation Center in which the experimental instruments and systems were established in compliance with European standards. The testing procedure followed EN 13274-1 (2001). As expected, leakages of half masks were less than those of filtering facepieces and the latter were significantly different among brands. TILs of the 1st class filtering facepieces were found to be much more than those of the 2nd class and the result may cause a wearer to get confused when selecting a mask. The main route leakage for filtering facepieces may not be the filter medium but the face seal. Therefore, it is necessary to develop well-fitting filtering facepieces for Koreans. Because leakages were significantly different for different facial dimensions, a defined test panel for IL or TIL testing according to country or race should be developed. A more precise method to demonstrate fit, for example, fit testing such as in the US regulations, will be needed before IL or TIL testing or when selecting a respirator. Another finding implies that geometric mean of five exercises for IL or TIL may be better than arithmetic mean to establish a standard individual subject mean.

  18. Improvements in powered air purifying respirator protection in an ABSL-3E facility

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The study of and experimentation with zoonotic pathogens such as highly pathogenic avian influenza (HPAI) requires risk mitigation strategies including laboratory engineering controls and safety equipment, personal protective equipment (PPE), and proper practices and techniques. Incidences of potent...

  19. Analysis of Air Purifying Respirator Cartridges and Filters as a Determination of Occupational Exposure

    DTIC Science & Technology

    1990-01-01

    0 CLCL1 C 0)X .1-0 --P-P) 4) NJ-ClOOVD CrN.- =3X X X *- D- ( in Z:E O.PZC occ L L .0l ON 101 C.\\ WULW Uj e fe - u0 fD (pOn C N0 0I 0 0-) M XL 4- - 1...C -P )4J 4.) ( EC L <C<( m )%+ )(InN - 4-) 4- o 1 C~iK* Q1 E EE IV J I fD + E - -0 to 10 - - +5 +-P* %N fO 3+3 -P:3 3f 3- 330 12 in U 10 U -u =r=eE

  20. Speech Intelligibility While Wearing Civilian Full-Facepiece Air-Purifying Respirators

    DTIC Science & Technology

    2010-06-01

    NIOSH score and the alternate average. Table 1 . Performance ratings by two methods Mask NIOSH Alternate FR-M40 87.84 88.00 C50 84.10 84.14 M TAC...49 95.1 FALSE 7/26/08 C50 241 245 49 1 48.8 50 97.6 FALSE 7/26/08 C50 242 245 49 1 48.8 50 97.6 FALSE 7/26/08 C50 243 245 45 3 44.4 48 92.5 FALSE 7...0188 Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing

  1. Aerosol penetration through filtering facepieces and respirator cartridges.

    PubMed

    Chen, C C; Lehtimäki, M; Willeke, K

    1992-09-01

    Air-purifying respirators must be certified following the National Institute for Occupational Safety and Health (NIOSH) filter test criteria (30 CFR 11). The criteria specify a range for the mean particle size and the measure of spread permissible for the test aerosol. The authors' experiments have shown that aerosol penetration as a function of particle size differs considerably among certified respirators of the same type. Filtering facepieces (disposable respirators) and cartridges of the dust-mist, dust-mist-fume, and high-efficiency particulate air type were tested. The respirators were sealed to mannequins in a test chamber. The aerosol concentrations inside and outside the respirator were measured by an aerodynamic particle sizer and a laser aerosol spectrometer over a particle size range of 0.1 to 15 microns. Five flow rates ranging from 5 to 100 L/min were used to study flow dependency. The aerosol penetration through the filters is presented as a function of particle size. Aerosol penetration and pressure drop are combined to express the performance of each filter in terms of "quality factor." Under the same test conditions, the quality factor of one respirator may be as much as 6.6 times more than that of another respirator of the same type. The filter quality factor has a greater aerosol size dependency as airflow and aerosol size increase. In general, cartridges have a larger surface area than filtering facepieces but not necessarily lower filter penetration or higher filter quality.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Cardiopulmonary Benefits of Reducing Indoor Particles of Outdoor Origin: a Randomized Double-Blind Crossover Trial of Air Purifiers

    PubMed Central

    Chen, Renjie; Zhao, Ang; Chen, Honglei; Zhao, Zhuohui; Cai, Jing; Wang, Cuicui; Yang, Changyuan; Li, Huichu; Xu, Xiaohui; Ha, Sandie; Li, Tiantian; Kan, Haidong

    2017-01-01

    Background Indoor exposure to fine particulate matter (PM2.5) from outdoor sources is a major health concern, especially in highly polluted developing countries, such as China. Few studies have evaluated the effectiveness of indoor air purification on the improvement of cardiopulmonary health in these areas. Objectives To evaluate whether a short-term indoor air purifier intervention improves cardiopulmonary health. Methods We conducted a randomized double-blind crossover trial among 35 healthy college students in Shanghai, China in 2014. These students lived in dormitories that were randomized into 2 groups and alternated the use of true or sham air purifiers for 48 h with a 2-week washout interval. We measured 14 circulating biomarkers of inflammation, coagulation and vasoconstriction, lung function, blood pressure (BP), and fractional exhaled nitric oxide (FeNO). We applied linear mixed-effect models to evaluate the effect of the intervention on health outcome variables. Results On average, air purification resulted in a 57% reduction in PM2.5 concentration from 96.2 to 41.3 μg/m3 within hours of operation. Air purification was significantly associated with decreases in geometric means of several circulating inflammatory and thrombogenic biomarkers, including 17.5% in monocyte chemoattractant protein-1, 68.1% in interleukin-1β, 32.8% in myeloperoxidase and 64.9% in soluble CD40 ligand. Further, systolic BP, diastolic BP, and FeNO were significantly decreased by 2.7%, 4.8%, and 17.0% in geometric mean, respectively. The impacts on lung function and vasoconstriction biomarkers were beneficial, but not statistically significant. Conclusion This intervention study demonstrated clear cardiopulmonary benefits of indoor air purification among young, healthy adults in a Chinese city with severe ambient particulate air pollution. (Intervention Study on the Health Impact of Air Filters in Chinese Adults; NCT02239744) PMID:26022815

  3. An Evaluation of Sharp Cut Cyclones for Sampling Diesel Particulate Matter Aerosol in the Presence of Respirable Dust

    PubMed Central

    Cauda, Emanuele; Sheehan, Maura; Gussman, Robert; Kenny, Lee; Volkwein, Jon

    2015-01-01

    Two prototype cyclones were the subjects of a comparative research campaign with a diesel particulate matter sampler (DPMS) that consists of a respirable cyclone combined with a downstream impactor. The DPMS is currently used in mining environments to separate dust from the diesel particulate matter and to avoid interferences in the analysis of integrated samples and direct-reading monitoring in occupational environments. The sampling characteristics of all three devices were compared using ammonium fluorescein, diesel, and coal dust aerosols. With solid spherical test aerosols at low particle loadings, the aerodynamic size-selection characteristics of all three devices were found to be similar, with 50% penetration efficiencies (d50) close to the design value of 0.8 µm, as required by the US Mine Safety and Health Administration for monitoring occupational exposure to diesel particulate matter in US mining operations. The prototype cyclones were shown to have ‘sharp cut’ size-selection characteristics that equaled or exceeded the sharpness of the DPMS. The penetration of diesel aerosols was optimal for all three samplers, while the results of the tests with coal dust induced the exclusion of one of the prototypes from subsequent testing. The sampling characteristics of the remaining prototype sharp cut cyclone (SCC) and the DPMS were tested with different loading of coal dust. While the characteristics of the SCC remained constant, the deposited respirable coal dust particles altered the size-selection performance of the currently used sampler. This study demonstrates that the SCC performed better overall than the DPMS. PMID:25060240

  4. Quantification of ozone levels in indoor environments generated by ionization and ozonolysis air purifiers.

    PubMed

    Britigan, Nicole; Alshawa, Ahmad; Nizkorodov, Sergey A

    2006-05-01

    Indoor air purifiers are advertised as safe household products for health-conscious individuals, especially for those suffering from allergies and asthma. However, certain air purifiers produce ozone (O3) during operation, either intentionally or as a byproduct of air ionization. This is a serious concern, because O3 is a criteria air pollutant regulated by health-related federal and state standards. Several types of air purifiers were tested for their ability to produce ozone in various indoor environments at 40-50% relative humidity, including office rooms, bathrooms, bedrooms, and cars. O3 levels generated by personal wearable air purifiers were also tested. In many cases, O3 concentrations were well in excess of public and/or industrial safety levels established by U.S. Environmental Protection Agency, California Air Resources Board, and Occupational Safety and Health Administration. Simple kinetic equations were obtained that can predict the steady-state level of O3 in a room from the O3 emission rate of the air purifier and the first-order decay rate of O3 in the room. The additivity of O3 levels generated by independent O3 generators was experimentally demonstrated.

  5. 42 CFR 84.1157 - Chemical cartridge respirators with particulate filters; performance requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., and mists of paints, lacquers, and enamels 50 70 20 1 Measured at end of service life specified in... specified in § 84.205. (c) Lacquer and enamel mist tests; general. (1) Three respirators with cartridges containing or having attached to them, filters for protection against mists of paints, lacquers, and...

  6. 42 CFR 84.1157 - Chemical cartridge respirators with particulate filters; performance requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air... respirator mounted on a test fixture with air flowing at a continuous rate of 85 liters per minute, both... rates (expressed in liters per minute (l.p.m.)) for 6 hours: Type of cartridge Airflow...

  7. Impact of Mining Waste on Airborne Respirable Particulates in Northeastern Oklahoma, United States

    EPA Science Inventory

    Atmospheric dispersion of particles from mine waste is potentially an important route of human exposure to metals in communities close to active and abandoned mining areas. In this study, we assessed sources of mass and metal concentrations in two size fractions of respirable pa...

  8. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... been neutralized to the Boltzmann equilibrium state shall be used. Each filter shall be challenged with... Boltzmann equilibrium state shall be used. Each filter shall be challenged with a concentration...

  9. Respirators: APR Issuer Self Study 33461

    SciTech Connect

    Chochoms, Michael

    2016-07-13

    Respirators: APR Issuer Self-Study (course 33461) is designed to introduce and familiarize employees selected as air-purifying respirator (APR) issuers at Los Alamos National Laboratory (LANL) with the responsibilities, limitations, procedures, and resources for issuing APRs at LANL. The goal is to enable these issuers to consistently provide proper, functioning APRs to authorized users

  10. Air purifiers that diffuse reactive oxygen species potentially cause DNA damage in the lung.

    PubMed

    Kawamoto, Kosuke; Sato, Itaru; Yoshida, Midori; Tsuda, Shuji

    2010-12-01

    Several appliance manufacturers have recently released new type air purifiers that can disinfect bacteria, fungi and viruses by diffusing reactive oxygen species (ROS) into the air. In this study, mice were exposed to the outlet air from each of 3 air purifiers from different manufacturers (A, B, C), and the lung was examined for DNA damage, lipid peroxidation and histopathology to confirm the safety of these air purifiers. Neither abnormal behavior during exposure nor gross abnormality at necropsy was observed. No histopathological changes were also observed in the lung. However, significant increase of DNA damage was detected by the comet assay in the lung immediately after the direct exposure for 48 hr to models A and B, and for 16 hr to model B. As for model B, DNA migration was also increased by 2 hr exposure in a 1 m(3) plastic chamber but not by 48 hr exposure in a room (12.6 m(3)). Model C did not cause DNA damage. Lipid peroxidation and 8-hydroxy deoxyguanosine (8-OH-dG) was not increased under the conditions DNA damage was detected by the comet assay. The present results revealed that some models of air purifiers that diffuse ROS potentially cause DNA damage in the lung although the mechanism was left unsolved.

  11. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying...

  12. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying...

  13. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying...

  14. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying...

  15. 42 CFR 84.1156 - Pesticide respirators; performance requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Pesticide respirators; performance requirements... DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1156 Pesticide respirators; performance requirements;...

  16. 42 CFR 84.1156 - Pesticide respirators; performance requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Pesticide respirators; performance requirements... DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1156 Pesticide respirators; performance requirements;...

  17. 42 CFR 84.1156 - Pesticide respirators; performance requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Pesticide respirators; performance requirements... DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1156 Pesticide respirators; performance requirements;...

  18. 42 CFR 84.1156 - Pesticide respirators; performance requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Pesticide respirators; performance requirements... DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1156 Pesticide respirators; performance requirements;...

  19. 42 CFR 84.1156 - Pesticide respirators; performance requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Pesticide respirators; performance requirements... DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators and Combination Gas Masks § 84.1156 Pesticide respirators; performance requirements;...

  20. Analysis of respirable particulate exposure and its effect to public health around lead smelter and e-waste processing industry in West Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Marselina, M.; Roosmini, D.; Salami, I. R. S.; Ayu A, M.; Cahyadi, W.

    2016-03-01

    Respirable particulate exposure strongly affects human health, especially for children who lived around industrial area. This study was conducted to evaluate the effect of respirable particulate exposure to lung capacity of children. Study location in this study was Parung Panjang District, area of lead smelter industry and also in Astana Anyar District, area of e-waste processing industry. Thirty children were involved in Astana Anyar District and also thirty children in Parung Panjang District. The control groups were also studied in both areas. Predicted average daily intake (ADD) of respirable particulate was estimated and lung or respiration condition of children was measured by using spirometer. The lung condition of respondents was estimated by FEV1.0 and FVC values. As the result, the predicted ADD of children in lead smelter area is 3 times higher than the predicted ADD of children in e-waste processing area. It was correlated positively with the higher PM2.5 concentration in Parung Panjang District than the PM2.5 concentration in Astana Anyar District. Metals concentration in Parung Panjang was also measured with X-Ray Fluorescence (XRF) in this study and it was clearly state that metals concentration in location study were higher than metals concentration in control area.

  1. Health and respirable particulate (PM10) air pollution: a causal or statistical association?

    PubMed Central

    Gamble, J F; Lewis, R J

    1996-01-01

    Numerous studies have reported weak but statistically significant acute health effects of particulate air pollution. The associations are observed at levels below the current U.S. standard of 150 micrograms/m3 (24 hr). Health effects include acute increased mortality from cardiopulmonary conditions and acute morbidity such as hospital admissions for related diseases. We reviewed recent epidemiology studies to evaluate whether criteria for causality are met, and we conclude that they are not. The weak associations are as likely to be due to confounding by weather, copollutants, or exposure misclassification as by ambient particulate matter (PM). The results from the same metropolitan areas are inconsistent, and PM explains such a small amount of the variability in mortality/morbidity that the association has little practical significance. Finally, experimental chamber studies of susceptible individuals exposed to PM concentrations well above 150 micrograms/m3 provide no evidence to support the morbidity/mortality findings. None of the criteria for establishing causality of the PM/mortality hypothesis are clearly met at ambient concentrations common in many U.S. cities. Images p838-a Figure 1. PMID:8875158

  2. Health effects of ambient levels of respirable particulate matter (PM) on healthy, young-adult population

    NASA Astrophysics Data System (ADS)

    Shaughnessy, William J.; Venigalla, Mohan M.; Trump, David

    2015-12-01

    There is an absence of studies that define the relationship between ambient particulate matter (PM) levels and adverse health outcomes among the young and healthy adult sub-group. In this research, the relationship between exposures to ambient levels of PM in the 10 micron (PM10) and 2.5 micron (PM2.5) size fractions and health outcomes in members of the healthy, young-adult subgroup who are 18-39 years of age was examined. Active duty military personnel populations at three strategically selected military bases in the United States were used as a surrogate to the control group. Health outcome data, which consists of the number of diagnoses for each of nine International Classification of Diseases, 9th Revision (ICD-9) categories related to respiratory illness, were derived from outpatient visits at each of the three military bases. Data on ambient concentrations of particulate matter, specifically PM10 and PM2.5, were obtained for these sites. The health outcome data were correlated and regressed with the PM10 and PM2.5 data, and other air quality and weather-related data on a daily and weekly basis for the period 1998 to 2004. Results indicate that at Fort Bliss, which is a US Environmental Protection Agency designated non-attainment area for PM10, a statistically significant association exists between the weekly-averaged number of adverse health effects in the young and healthy adult population and the corresponding weekly-average ambient PM10 concentration. A least squares regression analysis was performed on the Fort Bliss data sets indicated that the health outcome data is related to several environmental parameters in addition to PM10. Overall, the analysis estimates a .6% increase in the weekly rate of emergency room visits for upper respiratory infections for every 10 μg/m3 increase in the weekly-averaged PM10 concentration above the mean. The findings support the development of policy and guidance opportunities that can be developed to mitigate exposures

  3. Microbial respiration activities correlated to sequentially separated, particulate and water-soluble organic matter fractions from arable and forest topsoils

    NASA Astrophysics Data System (ADS)

    Kaiser, M.; Wirth, S.; Ellerbrock, R.; Sommer, M.

    2009-12-01

    Michael Kaiser1, Stephan Wirth2, Ruth H. Ellerbrock3, Michael Sommer3,4 1University of California Merced, Natural Science, 4225 N. Hospital Rd., Atwater, CA 95301 2,3 Leibniz-Center for Agricultural Research (ZALF) e. V. 2 Institute of Landscape Matter Dynamics 3 Institute of Soil Landscape Research Eberswalder Str. 84, D-15374 Muencheberg, Germany 4University of Potsdam, Institute of Geoecology, Karl-Liebknecht-Str. 24-25, 14476 Potsdam, Germany Microbial respiration activities correlated to sequentially separated, particulate and water-soluble organic matter fractions from arable and forest topsoils Microbial decomposition of soil organic matter (SOM) accounts for roughly half of CO2 evolution from vegetated soil surfaces and plays a crucial role in the ability of soil to mitigate the greenhouse effect. The separation and identification of labile (i.e., easily decomposable) organic matter (OM) fractions from bulk SOM is of particular importance for a mechanistic understanding of microbial decomposition processes and for predicting the response of SOM to changes in land use, management, and climate. This work aimed to reveal differences in the relevance of particulate as well as water-soluble organic matter (OM) fractions from topsoils to the easily biodegradable soil organic matter (SOM). We selected eight paired sites with quite different soil types (Udorthent, Paleudalf, Glossudalf, Aquept, Hapludalf, Aquert, Udert, Haplorthod) and soil properties (e.g., clay content: 28 to 564 g kg-1). For each of these sites, we took samples from adjacent arable and forest topsoils. Physically uncomplexed, macro-, and micro-aggregate-occluded organic particle, as well as water-soluble OM fractions were sequentially separated by a combination of electrostatic attraction, ultrasonic treatment, density separation, sieving, and water extraction. The easily biodegradable SOM of the topsoil samples was determined by measuring microbial respiration during a short-term incubation

  4. Effectiveness of dust control methods for crystalline silica and respirable suspended particulate matter exposure during manual concrete surface grinding.

    PubMed

    Akbar-Khanzadeh, Farhang; Milz, Sheryl A; Wagner, Cynthia D; Bisesi, Michael S; Ames, April L; Khuder, Sadik; Susi, Pam; Akbar-Khanzadeh, Mahboubeh

    2010-12-01

    Concrete grinding exposes workers to unacceptable levels of crystalline silica dust, known to cause diseases such as silicosis and possibly lung cancer. This study examined the influence of major factors of exposure and effectiveness of existing dust control methods by simulating field concrete grinding in an enclosed workplace laboratory. Air was monitored during 201 concrete grinding sessions while using a variety of grinders, accessories, and existing dust control methods, including general ventilation (GV), local exhaust ventilation (LEV), and wet grinding. Task-specific geometric mean (GM) of respirable crystalline silica dust concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled-grinding, while GV was off/on, were 0.17/0.09, 0.57/0.13, 1.11/0.44, and 23.1/6.80, respectively. Silica dust concentrations (mg/m³ using 100-125 mm (4-5 inch) and 180 mm (7 inch) grinding cups were 0.53/0.22 and 2.43/0.56, respectively. GM concentrations of silica dust were significantly lower for (1) GV on (66.0%) vs. off, and (2) LEV:HEPA- (99.0%), LEV:Shop-vac- (98.1%) or wet- (94.4%) vs. uncontrolled-grinding. Task-specific GM of respirable suspended particulate matter (RSP) concentrations (mg/m³ for LEV:HEPA-, LEV:Shop-vac-, wet-, and uncontrolled grinding, while GV was off/on, were 1.58/0.63, 7.20/1.15, 9.52/4.13, and 152/47.8, respectively. GM concentrations of RSP using 100-125 mm and 180 mm grinding cups were 4.78/1.62 and 22.2/5.06, respectively. GM concentrations of RSP were significantly lower for (1) GV on (70.2%) vs. off, and (2) LEV:HEPA- (98.9%), LEV:Shop-vac- (96.9%) or wet- (92.6%) vs. uncontrolled grinding. Silica dust and RSP were not significantly affected by (1) orientation of grinding surfaces (vertical vs. inclined); (2) water flow rates for wet grinding; (3) length of task-specific sampling time; or, (4) among cup sizes of 100, 115 or 125 mm. No combination of factors or control methods reduced an 8-hr exposure level to below the

  5. Identifying anthropogenic and natural influences on extreme pollution of respirable suspended particulates in Beijing using backward trajectory analysis.

    PubMed

    Song, Yu; Miao, Weijie; Liu, Bing; Dai, Wei; Cai, Xuhui

    2008-06-15

    In China, daily respirable suspended particulate (RSP, particles with aerodynamic diameters less than 10 microm) concentrations exceeding 420 microg m(-3) are considered "hazardous" to health. These can lead to the premature onset of certain diseases and premature death of sick and elderly people; even healthy people are warned to avoid outdoor activity when RSP concentrations are high. Such high pollution levels are defined as extreme RSP pollution events. Recent epidemiological studies have shown that a distinct difference exists between the health effects caused by natural sources and anthropogenic sources, mandating knowledge of the source of extreme RSP pollution. Twenty-six extreme RSP pollution events were recorded in Beijing from January 2003 to December 2006. The HYSPLIT4 (Hybrid Single Particle Lagrangian Integrated Trajectory) model (Version 4) was used to discriminate the sources of these extreme RSP pollution events. The model found that twelve events were caused from natural sources (dust storms), nine events from anthropogenic sources (e.g., vehicles and industrial activities, etc.) under quasi-quiescent weather, and five events were from mixed causes. Identifying such events will be valuable in epidemiological studies on air pollution in Beijing.

  6. Photocatalytic air purifiers for indoor air: European standard and pilot room experiments.

    PubMed

    Costarramone, N; Cantau, C; Desauziers, V; Pécheyran, C; Pigot, T; Lacombe, S

    2016-09-15

    At the European level (CEN/TC386), some efforts are currently devoted to new standards for comparing the efficiency of commercial photocatalytic material/devices in various application fields. Concerning prototype or commercial indoor photocatalytic air purifiers designed for volatile organic compounds (VOC) abatement, the methodology is based on a laboratory airtight chamber. The photocatalytic function is demonstrated by the mineralization of a mixture of five VOCs. Experimental data were obtained for four selected commercial devices and three commercial materials: drop of VOC concentration, but also identification of secondary species (with special attention to formaldehyde), mineralization rates, and Clean Air Delivery Rate (CADR). With two efficient air purifiers, these laboratory experiments were compared to the results in two experimental rooms (35-40 m(3)) where air pollution was introduced through wooden floor and furniture. The systems' ageing was also studied. The safety of the commercial products was also assessed by the determination of nanoparticle release. Standardized tests are useful to rank photocatalytic air purifiers and passive materials and to discard inefficient ones. A good correlation between the standard experiments and the experimental room experiments was found, even if in the latter case, the concentration of lower weight VOCs drops less quickly than that of heavier VOCs.

  7. 42 CFR 84.1130 - Respirators; description.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... respective vapors, or from the chemical reaction between their respective vapors and gases. (3) Air-purifying... reaction with sorbent material in the canister. (c) Pesticide respirators, including all completely...) Front-mounted or back-mounted gas masks; (2) Chin-style gas mask; (3) Chemical cartridge; (4)...

  8. 42 CFR 84.1130 - Respirators; description.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... respective vapors, or from the chemical reaction between their respective vapors and gases. (3) Air-purifying... reaction with sorbent material in the canister. (c) Pesticide respirators, including all completely...) Front-mounted or back-mounted gas masks; (2) Chin-style gas mask; (3) Chemical cartridge; (4)...

  9. 42 CFR 84.1130 - Respirators; description.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... respective vapors, or from the chemical reaction between their respective vapors and gases. (3) Air-purifying... reaction with sorbent material in the canister. (c) Pesticide respirators, including all completely...) Front-mounted or back-mounted gas masks; (2) Chin-style gas mask; (3) Chemical cartridge; (4)...

  10. 42 CFR 84.1130 - Respirators; description.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... respective vapors, or from the chemical reaction between their respective vapors and gases. (3) Air-purifying... reaction with sorbent material in the canister. (c) Pesticide respirators, including all completely...) Front-mounted or back-mounted gas masks; (2) Chin-style gas mask; (3) Chemical cartridge; (4)...

  11. 42 CFR 84.1130 - Respirators; description.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... respective vapors, or from the chemical reaction between their respective vapors and gases. (3) Air-purifying... reaction with sorbent material in the canister. (c) Pesticide respirators, including all completely...) Front-mounted or back-mounted gas masks; (2) Chin-style gas mask; (3) Chemical cartridge; (4)...

  12. Epidemiological-environmental study of diesel bus garage workers: acute effects of NO/sub 2/ and respirable particulate on the respiratory system

    SciTech Connect

    Gamble, J.; Jones, W.; Minshall, S.

    1987-02-01

    Personal samples of nitrogen dioxide (NO/sub 2/) and respirable particulate (RP) were collected over the shift on 232 workers in four diesel bus garages. Response was assessed by an acute respiratory questionnaire and before and after shift spirometry. Measures of exposure to NO/sub 2/ and RP were associated with work-related symptoms of cough; itching, burning, or watering eyes; difficult or labored breathing; chest tightness; and wheeze. The prevalence of burning eyes, headaches, difficult or labored breathing, nausea, and wheeze experienced at work were higher in the diesel bus garage workers than in a comparison population of battery workers, while the prevalence of headaches was reduced. Mean reductions in forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), peak flow, and flows at 50 and 75% of FVC were not obviously different from zero. There was no detectable association of exposure to NO/sub 2/ or respirable particulate and acute reductions in pulmonary function. Workers who often had respiratory work-related symptoms generally had a slightly greater mean acute reduction in FEV1 and FEF50 than did those who did not have these symptoms, but these differences were not statistically significant.

  13. Performance of an N95 filtering facepiece particulate respirator and a surgical mask during human breathing: two pathways for particle penetration.

    PubMed

    Grinshpun, Sergey A; Haruta, Hiroki; Eninger, Robert M; Reponen, Tiina; McKay, Roy T; Lee, Shu-An

    2009-10-01

    The protection level offered by filtering facepiece particulate respirators and face masks is defined by the percentage of ambient particles penetrating inside the protection device. There are two penetration pathways: (1) through the faceseal leakage, and the (2) filter medium. This study aimed at differentiating the contributions of these two pathways for particles in the size range of 0.03-1 microm under actual breathing conditions. One N95 filtering facepiece respirator and one surgical mask commonly used in health care environments were tested on 25 subjects (matching the latest National Institute for Occupational Safety and Health fit testing panel) as the subjects performed conventional fit test exercises. The respirator and the mask were also tested with breathing manikins that precisely mimicked the prerecorded breathing patterns of the tested subjects. The penetration data obtained in the human subject- and manikin-based tests were compared for different particle sizes and breathing patterns. Overall, 5250 particle size- and exercise-specific penetration values were determined. For each value, the faceseal leakage-to-filter ratio was calculated to quantify the relative contributions of the two penetration pathways. The number of particles penetrating through the faceseal leakage of the tested respirator/mask far exceeded the number of those penetrating through the filter medium. For the N95 respirator, the excess was (on average) by an order of magnitude and significantly increased with an increase in particle size (p < 0.001): approximately 7-fold greater for 0.04 microm, approximately 10-fold for 0.1 microm, and approximately 20-fold for 1 microm. For the surgical mask, the faceseal leakage-to-filter ratio ranged from 4.8 to 5.8 and was not significantly affected by the particle size for the tested submicrometer fraction. Facial/body movement had a pronounced effect on the relative contribution of the two penetration pathways. Breathing intensity and

  14. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL...

  15. Voluntary use of respirators.

    PubMed

    Feiner, Lynn

    2009-11-01

    Allowing voluntary use of respirators can provide workers with an added level of comfort and relief from nuisance levels of particulates, gases, or vapors. But misuse can result in illness or injury to the worker. Understanding and following OSHA's guidelines on voluntary use of respirators is one of the many ways you help provide a safe workplace and ensure your employees stay healthy.

  16. Halogenated flame-retardant concentrations in settled dust, respirable and inhalable particulates and polyurethane foam at gymnastic training facilities and residences.

    PubMed

    La Guardia, Mark J; Hale, Robert C

    2015-06-01

    Halogenated flame-retardants (FRs) are used in a wide array of polymer-containing products. Animal studies and structure-activity modeling exercises suggest that FR exposure may result in detrimental toxicological effects. Workers with extended contact with such polymers (e.g., electronic dismantlers, carpet installers and aircraft personnel) have previously been observed to exhibit elevated body burdens of FRs, e.g., polybrominated diphenyl ethers (PBDEs). Recently, elevated PBDE blood levels were also reported in a non-occupational exposure group, gymnasts. These levels were hypothesized to be related to the large volumes of FR-treated polyurethane foam in gymnastics facilities. To further our understanding of workers' potential exposure, we analyzed FR concentrations in indoor dust and size-fractionated air particulates (respirable (<4 μm) and inhalable (>4 μm)) from gymnastic studios. Values were compared to samples from the homes of coaches employed at these facilities. Polyurethane foam blocks (i.e., pit foam) were also analyzed to characterize potential FR sources. FRs examined included those used to flame-retard polyurethane foam: 8 PBDE congeners, two brominated components of Firemaster 550 (2-ethylhexyl 2, 3, 4, 5-tetrabromobenzoate (TBB) and bis(2-ethylhexyl) 3, 4, 5, 6-tetrabromophthalate (TBPH)) and three chlorinated organophosphates (tris(2-chloroethyl) phosphate (TCEP), tris(1-chloro-2-propyl) phosphate (TCPP) and tris(1,3-dichloro-2-propyl) phosphate (TDCPP)). Several additional FRs not used in polyurethane were also evaluated. These have also been detected in indoor dust and air and may also lead to adverse health effects. These include: BDE-183 and its replacement product (1, 2-bis(2, 4, 6-tribromophenoxy) ethane (BTBPE), two congeners of the deca-BDE formulation (BDE-206, -209) and their replacement decabromodiphenyl ethane (DBDPE) and hexabromocyclododecane (α-, β-, γ-HBCD), and tetrabromobisphenol-A (TBBPA)). Pit foam contained multiple

  17. 42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High..., airflow will be cycled through the respirator by a breathing machine at the rate of 24 respirations per minute with a minute volume of 40 liters; a breathing machine cam with a work rate of 622...

  18. 42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High..., airflow will be cycled through the respirator by a breathing machine at the rate of 24 respirations per minute with a minute volume of 40 liters; a breathing machine cam with a work rate of 622...

  19. 42 CFR 84.1145 - Silica dust test; non-powered single-use dust respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High..., airflow will be cycled through the respirator by a breathing machine at the rate of 24 respirations per minute with a minute volume of 40 liters; a breathing machine cam with a work rate of 622...

  20. Reducing Staphylococcus aureus bacterial counts in a dental clinic using an Ionic Breeze air purifier: a preliminary study.

    PubMed

    Hubar, J Sean; Pelon, William; Strother, Elizabeth A; Sicard, F Scott

    2009-01-01

    Aerosols and droplets generated by dental procedures are contaminated with blood and bacteria and represent a potential route for the transmission of disease. This study sought to determine if Ionic Breeze air purifiers are effective in collecting and destroying bacteria found in dental aerosols (such as Staphylococcus aureus). This study placed one Sharper Image Professional Series Ionic Breeze Quadra unit and one Ionic Breeze GP unit (with germicidal protection) in dental operatories within the Louisiana State University School of Dentistry. After six hours of operation, bacterial samples were collected and streaked over surfaces of petri dishes containing trypticase soy sucrose bacitracin agar that had been supplemented with 5% sheep blood. The samples were incubated at 37 degrees C for 48 hours; at that point, the microbial colonies were counted. Additional testing was performed on suspect colonies to identify S. aureus strains and to determine if any of those isolates were pathogenic with or without antibiotic resistance. The Ionic Breeze GP unit killed more than 99% of all bacteria on the stainless steel collecting blades. The non-germicidal Ionic Breeze Quadra air purifier collected numerous bacteria that were found to include some pathogenic strains of S. aureus; however, none of these were resistant to antibiotics.

  1. Pulmonary oxidative stress, inflammation and cancer: respirable particulate matter, fibrous dusts and ozone as major causes of lung carcinogenesis through reactive oxygen species mechanisms.

    PubMed

    Valavanidis, Athanasios; Vlachogianni, Thomais; Fiotakis, Konstantinos; Loridas, Spyridon

    2013-08-27

    Reactive oxygen or nitrogen species (ROS, RNS) and oxidative stress in the respiratory system increase the production of mediators of pulmonary inflammation and initiate or promote mechanisms of carcinogenesis. The lungs are exposed daily to oxidants generated either endogenously or exogenously (air pollutants, cigarette smoke, etc.). Cells in aerobic organisms are protected against oxidative damage by enzymatic and non-enzymatic antioxidant systems. Recent epidemiologic investigations have shown associations between increased incidence of respiratory diseases and lung cancer from exposure to low levels of various forms of respirable fibers and particulate matter (PM), at occupational or urban air polluting environments. Lung cancer increases substantially for tobacco smokers due to the synergistic effects in the generation of ROS, leading to oxidative stress and inflammation with high DNA damage potential. Physical and chemical characteristics of particles (size, transition metal content, speciation, stable free radicals, etc.) play an important role in oxidative stress. In turn, oxidative stress initiates the synthesis of mediators of pulmonary inflammation in lung epithelial cells and initiation of carcinogenic mechanisms. Inhalable quartz, metal powders, mineral asbestos fibers, ozone, soot from gasoline and diesel engines, tobacco smoke and PM from ambient air pollution (PM₁₀ and PM₂.₅) are involved in various oxidative stress mechanisms. Pulmonary cancer initiation and promotion has been linked to a series of biochemical pathways of oxidative stress, DNA oxidative damage, macrophage stimulation, telomere shortening, modulation of gene expression and activation of transcription factors with important role in carcinogenesis. In this review we are presenting the role of ROS and oxidative stress in the production of mediators of pulmonary inflammation and mechanisms of carcinogenesis.

  2. Double-blind study of suppression of indoor fungi and bacteria by the PuriDyne biogenic air purifier.

    PubMed

    Nelson, H S; Skufca, R M

    1991-03-01

    The PuriDyne Air Purification System was studied in a double-blind trial for its ability to reduce the prevalence of bacteria and fungi in residential units. Twelve apartments were studied employing an Andersen Sampler for airborne fungi and Rodac plates for surface bacteria. Following determination of baseline levels, PuriDyne units with active filters were installed in six apartments, and units with inactive filters in six others. Sampling continued weekly for 1 month while the Air Purifiers were in place and at the end of 2 weeks following their removal. There was no statistically significant difference in airborne fungal or surface bacterial levels between baseline and treatment periods for apartments with either active or inactive units, nor were there significant differences between the two groups at any time.

  3. An evaluation of respirator maintenance requirements.

    PubMed

    Brosseau, L M; Traubel, K

    1997-03-01

    A telephone survey was developed as part of a pilot study to evaluate the inspection, cleaning, maintenance, and storage aspects of respirator protection programs (RPP). Regulations and consensus standards such as those published by the Occupational Safety and Health Administration in the Code of Federal Regulations (CFR) or the American National Standards Institute (ANSI) require or recommend that RPP contain elements that ensure that the respirators provide proper protection. A great deal of research has been done to evaluate the effectiveness of new respirators; however, little research has been conducted to evaluate how respirators behave over time in real industrial settings Respirator inspection, cleaning, maintenance, and storage are significant factors in determining how well a respirator continues to perform. The telephone survey was developed by reviewing the requirements and recommendations of CFR 1910.134 and ANSI Z88.2-1980. Approximately 30 companies were selected based on their use of negative air-purifying respirators. Most of the companies represented the hardgoods manufacturing or service industries. Although the majority of companies were meeting requirements, responses indicated that the following improvements in RPP were necessary: (1) inspection of all respirator parts should be carried out before and after each use, (2) replacement parts should be made readily available on site, (3) regular cleaning should be performed, and (4) more hands-on practice with respirators and their maintenance should be incorporated into training sessions.

  4. Photocatalytic performance of electrospun CNT/TiO2 nanofibers in a simulated air purifier under visible light irradiation.

    PubMed

    Wongaree, Mathana; Chiarakorn, Siriluk; Chuangchote, Surawut; Sagawa, Takashi

    2016-11-01

    The photocatalytic treatment of gaseous benzene under visible light irradiation was developed using electrospun carbon nanotube/titanium dioxide (CNT/TiO2) nanofibers as visible light active photocatalysts. The CNT/TiO2 nanofibers were fabricated by electrospinning CNT/poly(vinyl pyrrolidone) (PVP) solution followed by the removal of PVP by calcination at 450 °C. The molar ratio of CNT/TiO2 was fixed at 0.05:1 by weight, and the quantity of CNT/TiO2 loaded in PVP solution varied between 30 and 60 % wt. CNT/TiO2 nanofibers have high specific surface area (116 m(2)/g), significantly higher than that of TiO2 nanofibers (44 m(2)/g). The photocatalytic performance of the CNT/TiO2 nanofibers was investigated by decolorization of 1 × 10(-5) M methylene blue (MB) dye (in water solution) and degradation of 100 ppm gaseous benzene under visible light irradiation. The 50-CNT/TiO2 nanofibers (calcined CNT/TiO2 nanofibers fabricated from a spinning solution of 50 % wt CNT/TiO2 based on PVP) had higher MB degradation efficiency (58 %) than did other CNT/TiO2 nanofibers and pristine TiO2 nanofibers (15 %) under visible light irradiation. The photocatalytic degradation of gaseous benzene under visible light irradiation on filters made of 50-CNT/TiO2 nanofibers was carried out in a simulated air purifier system. Similar to MB results, the degradation efficiency of gaseous benzene by 50-CNT/TiO2 nanofibers (52 %) was higher than by other CNT/TiO2 nanofibers and pristine TiO2 nanofibers (18 %). The synergistic effects of the larger surface area and lower band gap energy of CNT/TiO2 nanofibers were presented as strong adsorption ability and greater visible light adsorption. The CNT/TiO2 nanofiber prepared in this study has potential for use in air purifiers to improve air treatment efficiency with less energy.

  5. 42 CFR 84.1102 - Examination, inspection and testing of complete respirator assemblies; fees.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... particulate filter, including pesticide gas masks— (1) Single hazard—$1,100. (2) Type N—$4,100. (b) Dust,...

  6. 42 CFR 84.1102 - Examination, inspection and testing of complete respirator assemblies; fees.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... particulate filter, including pesticide gas masks— (1) Single hazard—$1,100. (2) Type N—$4,100. (b) Dust,...

  7. 42 CFR 84.1102 - Examination, inspection and testing of complete respirator assemblies; fees.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... particulate filter, including pesticide gas masks— (1) Single hazard—$1,100. (2) Type N—$4,100. (b) Dust,...

  8. 42 CFR 84.1102 - Examination, inspection and testing of complete respirator assemblies; fees.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... particulate filter, including pesticide gas masks— (1) Single hazard—$1,100. (2) Type N—$4,100. (b) Dust,...

  9. Positive and negative ions by air purifier have no effects on embryo-fetal development in rats.

    PubMed

    Yamamoto, Dai; Wako, Kiyoshi; Sato, Yukari; Fujishiro, Mayumi; Matsuura, Ikuo; Ohnishi, Yasuyuki

    2014-06-01

    Air purifiers, which release positive and negative ions generated by an electric discharge into the air, have been widely used in common households. In this study, the developmental toxicity potential of the ionized air containing positive and negative ions was evaluated in SD rats [Crl:CD(SD)] following whole-body inhalation to obtain preliminary information for the definitive study. Two groups of 10 pregnant female rats were exposed to the ionized air at concentrations of 0 and 7,000,000 ions/cm(3) for 6 hr per day from Days 6 to 19 of gestation. All dams underwent a cesarean section on Day 20 of gestation and their fetuses were examined externally, viscerally, and skeletally for morphological changes. The ionized air had no effects on dams in terms of clinical signs, body weight, food consumption, gravid uterine weights, corrected body weight by gravid uterine weight, or necropsy findings. In addition, there were no effects on the maintenance of pregnancy, including abortion or premature delivery. No exposure-related changes were detected in the number of corpora lutea, implantations, dead embryos, or live fetuses, implantation loss, live fetal weights, sex ratio, or placental weight or features. Fetal examination revealed no external, visceral, or skeletal anomalies or variations caused by the ionized air, nor were there any changes in degree of ossification. Although this study did not fully adhere to the current guidelines because of a smaller number of animals per group, it was suggested that the ionized air has no maternal toxicity or embryo-fetal toxicity in rats.

  10. Evaluation of a plant material-based air purifier for removing H2S, NH3 and swine manure odour.

    PubMed

    Zhou, Xuezhi; Zhang, Qiang; Huang, Anhong

    2012-12-01

    A plant material-based air purifier (PMAP) was evaluated for odour removal. Laboratory tests were performed using two identical chambers: one treated by PMAP, and one as the control. Swine manure, hydrogen sulphide (H2S) and ammonia (NH3) were tested as odour sources. The test was also conducted in a swine barn. Air samples were taken from test chambers and two rooms in the pig barn and analysed for H2S, NH3 and odour concentrations. When treated with PMAP, the H2S concentration in the sealed chamber was subject to exponential decay, with the decay constant ranging from 0.59 to 0.70 l/h. The H2S concentration was reduced from 20 to 3 ppm in 3 h and to 0.2 ppm in 7h for H2S produced by chemical reaction, and from 0.4 to 0.02 ppm in 3 h for swine manure as the odour source. When an equal amount of ammonia solution was placed in the two test chambers, the NH3 concentration reached a peak value of 25 ppm in the chamber treated by PMAP, and 43 ppm in the control. The NH3 concentration in the treated chamber was reduced to 5 ppm in 3.5 h but stayed at 37 ppm in the control. The PMAP reduced the NH3 concentration from 38 to 10 ppm when swine manure was used as the odour source. The PMAP was capable of reducing swine odour in both laboratory and in-barn conditions. The reduction rate was at least 50%. The results from this research indicate the plant-based materials provide an alternative, environmentally friendly way for odour control. It is also shown that the mode of odour reduction by the PMAP was the removal of odour compounds, in contrast to odour masking, which occurs for most plant materials that have been used for odour control.

  11. Noninvasive, quantitative respirator fit testing through dynamic pressure measurement.

    PubMed

    Carpenter, D R; Willeke, K

    1988-10-01

    A new method has been invented for the noninvasive and quantitative determination of fit for a respirator. The test takes a few seconds and requires less expensive instrumentation than presently used for invasive testing. In this test, the breath is held at a negative pressure for a few seconds, and the leak-induced pressure decay inside the respirator cavity is monitored. A dynamic pressure sensor is attached to a modified cartridge of an air-purifying respirator or built into the respirator body or into the air supply line of an air-supplied respirator. The method is noninvasive in that the modified cartridge can be mounted onto any air-purifying respirator. The pressure decay during testing quantifies the airflow entered through the leak site. An equation has been determined which gives the air leakage as a function of pressure decay slope, respirator volume and the pressure differential during actual wear--all of which are determined by the dynamic pressure sensor. Thus, the ratio of air inhaled through the filters or via the air supply line to the leak rate is a measure of respirator fit, independent of aerosol deposition in the lung and aerosol distribution in the respirator cavity as found for quantitative fit testing with aerosols. The new method is shown to be independent of leak and sensor locations. The concentration and distribution of aerosols entered through the leak site is dependent only on the physical dimensions of the leak site and the air velocity in it, which can be determined independently.(ABSTRACT TRUNCATED AT 250 WORDS)

  12. Respiration in the open ocean.

    PubMed

    del Giorgio, Paul A; Duarte, Carlos M

    2002-11-28

    A key question when trying to understand the global carbon cycle is whether the oceans are net sources or sinks of carbon. This will depend on the production of organic matter relative to the decomposition due to biological respiration. Estimates of respiration are available for the top layers, the mesopelagic layer, and the abyssal waters and sediments of various ocean regions. Although the total open ocean respiration is uncertain, it is probably substantially greater than most current estimates of particulate organic matter production. Nevertheless, whether the biota act as a net source or sink of carbon remains an open question.

  13. Genotoxicity of Polycyclic Aromatic Hydrocarbons and Nitro-Derived in Respirable Airborne Particulate Matter Collected from Urban Areas of Rio de Janeiro (Brazil)

    PubMed Central

    Ramos de Rainho, Claudia; Machado Corrêa, Sérgio; Luiz Mazzei, José; Alessandra Fortes Aiub, Claudia

    2013-01-01

    Air pollution toxic effects are mainly attributed to small inhalable particulates with an aerodynamic diameter of less than 2.5 µm (PM 2.5). Our objective was to investigate mutagenic and clastogenic activity in PM samples collected in Rio de Janeiro. Samples were collected using a high-volume sampler at three sites: with low traffic and (2) and (3) with a heavy traffic. Six polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography/mass spectrometry (GC/MS). Salmonella typhimurium TA98 and the derivative strains YG1021 and YG1024 were used in mutagenicity assays in the presence of organic extracts (10–50 µg/ plate) with and without exogenous metabolization. Allium cepa test was performed to evaluate possible cytotoxic and clastogenic activities. The highest PM 2.5 µm (132.73 µm/m3) and PAH values (1.22 ng/m3 for benzo(a)pyrene) were detected at site 3. High mutagenic frameshift responses in absence and presence of metabolic activation were detected at site 3. The participation of nitroarenes and dinitroarenes was detected in the total mutagenicity of the extracts studied. The cytotoxic effect and the abnormalities detected by Allium cepa test can be attributed to the PAH nitroderivatives in the organic extracts. Evaluation of the genotoxicity of urban airborne particulate matter is important as a basis for decision making by regulatory authorities. PMID:23738331

  14. The Diesel Exhaust in Miners Study: III. Interrelations between respirable elemental carbon and gaseous and particulate components of diesel exhaust derived from area sampling in underground non-metal mining facilities.

    PubMed

    Vermeulen, Roel; Coble, Joseph B; Yereb, Daniel; Lubin, Jay H; Blair, Aaron; Portengen, Lützen; Stewart, Patricia A; Attfield, Michael; Silverman, Debra T

    2010-10-01

    Diesel exhaust (DE) has been implicated as a potential lung carcinogen. However, the exact components of DE that might be involved have not been clearly identified. In the past, nitrogen oxides (NO(x)) and carbon oxides (CO(x)) were measured most frequently to estimate DE, but since the 1990s, the most commonly accepted surrogate for DE has been elemental carbon (EC). We developed quantitative estimates of historical exposure levels of respirable elemental carbon (REC) for an epidemiologic study of mortality, particularly lung cancer, among diesel-exposed miners by back-extrapolating 1998-2001 REC exposure levels using historical measurements of carbon monoxide (CO). The choice of CO was based on the availability of historical measurement data. Here, we evaluated the relationship of REC with CO and other current and historical components of DE from side-by-side area measurements taken in underground operations of seven non-metal mining facilities. The Pearson correlation coefficient of the natural log-transformed (Ln)REC measurements with the Ln(CO) measurements was 0.4. The correlation of REC with the other gaseous, organic carbon (OC), and particulate measurements ranged from 0.3 to 0.8. Factor analyses indicated that the gaseous components, including CO, together with REC, loaded most strongly on a presumed 'Diesel exhaust' factor, while the OC and particulate agents loaded predominantly on other factors. In addition, the relationship between Ln(REC) and Ln(CO) was approximately linear over a wide range of REC concentrations. The fact that CO correlated with REC, loaded on the same factor, and increased linearly in log-log space supported the use of CO in estimating historical exposure levels to DE.

  15. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... respirators meet the minimum requirement for § 721.63(a)(4): Air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  16. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... respirators meet the minimum requirement for § 721.63(a)(4): Air-purifying, tight-fitting full-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  17. 40 CFR 721.10171 - 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonic acid (1:1).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... with an APF of 10-25 meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face... Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting...

  18. 40 CFR 721.10171 - 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonic acid (1:1).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... with an APF of 10-25 meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face... Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting...

  19. 40 CFR 721.10171 - 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonic acid (1:1).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... with an APF of 10-25 meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face... Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting...

  20. 40 CFR 721.10171 - 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonic acid (1:1).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... with an APF of 10-25 meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face... Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting...

  1. 40 CFR 721.10171 - 1H-benz(e)indolium, 1,1,2,3-tetramethyl-, 4-methylbenzenesulfonic acid (1:1).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... with an APF of 10-25 meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face... Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting...

  2. Exposure to inhalable, respirable, and ultrafine particles in welding fume.

    PubMed

    Lehnert, Martin; Pesch, Beate; Lotz, Anne; Pelzer, Johannes; Kendzia, Benjamin; Gawrych, Katarzyna; Heinze, Evelyn; Van Gelder, Rainer; Punkenburg, Ewald; Weiss, Tobias; Mattenklott, Markus; Hahn, Jens-Uwe; Möhlmann, Carsten; Berges, Markus; Hartwig, Andrea; Brüning, Thomas

    2012-07-01

    This investigation aims to explore determinants of exposure to particle size-specific welding fume. Area sampling of ultrafine particles (UFP) was performed at 33 worksites in parallel with the collection of respirable particles. Personal sampling of respirable and inhalable particles was carried out in the breathing zone of 241 welders. Median mass concentrations were 2.48 mg m(-3) for inhalable and 1.29 mg m(-3) for respirable particles when excluding 26 users of powered air-purifying respirators (PAPRs). Mass concentrations were highest when flux-cored arc welding (FCAW) with gas was applied (median of inhalable particles: 11.6 mg m(-3)). Measurements of particles were frequently below the limit of detection (LOD), especially inside PAPRs or during tungsten inert gas welding (TIG). However, TIG generated a high number of small particles, including UFP. We imputed measurements respirable or inhalable fraction of the welding fume (expressed as their mass) remains challenging.

  3. Indoor-outdoor relationships of respirable sulfates and particles

    NASA Astrophysics Data System (ADS)

    Dockery, Douglas W.; Spengler, John D.

    Indoor and outdoor concentrations of respirable particulates and sulfates have been measured in 68 homes in six cities for at least 1 yr. A conservation of mass model was derived describing indoor concentrations in terms of outdoor concentrations, infiltration and indoor sources. The measured data were analysed to identify important building characteristics and to quantify their effect. The mean infiltration rate of outdoor fine particulates was found to be approximately 70%. Cigarette smoking was found to be the dominant indoor source of respirable particulates. Increased indoor concentrations of sulfates were found to be associated with smoking and also with gas stoves. The effect of full air conditioning of the building was to reduce infiltration of outdoor fine particulates by about one half, while preventing dilution and purging of internally generated pollutants. The model for indoor respirable particulate and sulfate levels was found to compare well with measurements.

  4. Immobilization of CO 2 by aqueous K 2CO 3 using microfibrous media entrapped small particulates for battery and fuel cell applications

    NASA Astrophysics Data System (ADS)

    Sathitsuksanoh, Noppadon; Yang, Hongyun; Cahela, Donald R.; Tatarchuk, Bruce J.

    This work focuses on developing a new adsorptive material and regenerable system for CO 2 sequestration to supply CO 2-free gas stream for low temperature and low carbon dioxide concentration applications, such as alkaline fuel cells, metal-air batteries, and portable air-purifying respirators. A novel microfibrous media has been introduced for carbon dioxide filtration from wet gas streams at room temperature. The use of microfibrous media in a composite bed maximizes the breakthrough capacity per unit volume and promotes high accessibility. The microfibrous media synergically combines the high contacting efficiency of the microfibrous matrix and the small internal mass transfer resistance of small particulates. The carbon dioxide adsorption capacity of the microfibrous media can be reversibly recovered. The incorporation of microfibrous media to the sodalime was observed. The result shows 120% improvement in the breakthrough capacity compared with the packed bed of the sodalime with the same volume. This approach can be applied to miniaturize the reactor and reduce thermal mass enhancing process intensification.

  5. Using CO2 to Determine Inhaled Contaminant Volumes and Blower Effectiveness in Several Types of Respirators

    PubMed Central

    Johnson, Arthur T.; Koh, Frank C.; Scott, William H.; Rehak, Timothy E.

    2011-01-01

    This experiment was conducted to determine how much contaminant could be expected to be inhaled when overbreathing several different types of respirators. These included several tight-fitting and loose-fitting powered air-purifying respirators (PAPRs) and one air-purifying respirator (APR). CO2 was used as a tracer gas in the ambient air, and several loose-and tight-fitting respirators were tested on the head form of a breathing machine. CO2 concentration in the exhaled breath was monitored as well as CO2 concentration in the ambient air. This concentration ratio was able to give a measurement of protection factor, not for the respirator necessarily, but for the wearer. Flow rates in the filter/blower inlet and breathing machine outlet were also monitored, so blower effectiveness (defined as the blower contribution to inhaled air) could also be determined. Wearer protection factors were found to range from 1.1 for the Racal AirMate loose-fitting PAPR to infinity for the 3M Hood, 3M Breath-Easy PAPR, and SE 400 breath-responsive PAPR. Inhaled contaminant volumes depended on tidal volume but ranged from 2.02 L to 0 L for the same respirators, respectively. Blower effectiveness was about 1.0 for tight-fitting APRs, 0.18 for the Racal, and greater than 1.0 for two of the loose-fitting PAPRs. With blower effectiveness greater than 1.0, some blower flow during the exhalation phase contributes to the subsequent inhalation. Results from this experiment point to different ways to measure respirator efficacy. PMID:21792358

  6. Using CO(2) to determine inhaled contaminant volumes and blower effectiveness in several types of respirators.

    PubMed

    Johnson, Arthur T; Koh, Frank C; Scott, William H; Rehak, Timothy E

    2011-01-01

    This experiment was conducted to determine how much contaminant could be expected to be inhaled when overbreathing several different types of respirators. These included several tight-fitting and loose-fitting powered air-purifying respirators (PAPRs) and one air-purifying respirator (APR). CO(2) was used as a tracer gas in the ambient air, and several loose-and tight-fitting respirators were tested on the head form of a breathing machine. CO(2) concentration in the exhaled breath was monitored as well as CO(2) concentration in the ambient air. This concentration ratio was able to give a measurement of protection factor, not for the respirator necessarily, but for the wearer. Flow rates in the filter/blower inlet and breathing machine outlet were also monitored, so blower effectiveness (defined as the blower contribution to inhaled air) could also be determined. Wearer protection factors were found to range from 1.1 for the Racal AirMate loose-fitting PAPR to infinity for the 3M Hood, 3M Breath-Easy PAPR, and SE 400 breath-responsive PAPR. Inhaled contaminant volumes depended on tidal volume but ranged from 2.02  L to 0  L for the same respirators, respectively. Blower effectiveness was about 1.0 for tight-fitting APRs, 0.18 for the Racal, and greater than 1.0 for two of the loose-fitting PAPRs. With blower effectiveness greater than 1.0, some blower flow during the exhalation phase contributes to the subsequent inhalation. Results from this experiment point to different ways to measure respirator efficacy.

  7. Effects of respirators on worker efficiency. Final report

    SciTech Connect

    Cardarelli, R.; Woldstad, J.; Slobodien, M.J.; Madison, J.M.

    1995-06-01

    The purpose of this study was to quantify the effect of full face piece air purifying respirator use on worker efficiency. With and without a respirator, twenty nuclear power plant workers performed a typical mechanical work task and 2 dexterity tests in an environmental chamber maintained at a temperature of 35{degrees}C (95{degrees}F) and a relative humidity of 65%. The subjects were trained for one day and tested on the following day. On test day, each subject performed each standardized task twice in full cotton protective clothing, once with a respirator and once without. The order in which subjects performed the task with and without a respirator was staggered. The standardized tasks consisted of a stud torquing procedure and two separate trials of a pegboard dexterity test (before and after the torquing procedure). All subject testing wa videotaped and the videotapes were time coded for evaluation by an independent reviewer who determined the times for task completion. The 95% confidence intervals for the mean percentage increase in time to complete the various tasks for trials using th respirator were: 1st Dexterity Test (Lower Limit -1.16%, Mean 3.05%, Upper Limit 7.27%); Stud Torquing (Lower Limit -0.99%, Mean 2.11%, Upper Limit 5.21%); 2nd Dexterity Test (Lower Limit -2.06%, Mean 1.62%, Upper Limit 5.30%). These small increases in completion times attributable to respirator use were not statistically significant. It was concluded that respirator use had no significant effect on the efficiency with which workers conducted the tasks in this study.

  8. Effects of respirators under heat/work conditions

    SciTech Connect

    James, R.; Dukes-Dobos, F.; Smith, R.

    1984-06-01

    Physiological responses and perceived strain of five unacclimatized male subjects were studied. The subjects were exposed to heat during an exercise task and were evaluated while wearing half and full facepiece, cartridge-type, air-purifying respirators, and without a respirator. The exercise consisted of walking on a treadmill for a period of 1 hour in a controlled environmental chamber at each of two different energy expenditure levels (200 and 400 kcal/hr)(approx. = 58 and 116 Watts) and two different heat exposures (air temperatures of 25/sup 0/C and 43.3./sup 0/C). The results indicated that wearing a full facepiece respirator imposed significant physiological strain added to that caused by the heat and workloads used in the study. Five of the six physiological measures show this increased physiological strain: (1) heart rate; (2) minute ventilation; (3) oxygen consumption; (4) energy expenditure; and (5) oral temperature. There was no detectable effect on sweat rate. Although subjective ratings indicated more discomfort with increasing physiological strain, the observed correlations between such measures were low (T/sub b/ < .60). The net consequence of the significant effects indicates that workers' tolerance to moderate or high levels of work under hot conditions while wearing a respirator is reduced. The reduction is more pronounced when wearing a full mask than when wearing a half mask. Changes in respirator design which minimize respiratory dead space are suggested to alleviate this problem. Otherwise, prevention of excessive physiological strain from respirator use when working at moderate or higher levels at hot job sites could necessitate more rest breaks or limiting work time under such conditions.

  9. 40 CFR 721.9719 - Tris carbamoyl triazine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... filter (N100 if oil aerosols are absent, R100, or P100); (B) Air purifying, tight-fitting full-face... the requirements for § 721.63(a)(4): (A) Air purifying, tight-fitting half-face respirator equipped... include a particulate filter (N100 if oil aerosols are absent, R100, or P100); (C) Powered...

  10. Nosepiece respiration monitor

    NASA Technical Reports Server (NTRS)

    Lavery, A. L.; Long, L. E.; Rice, N. E.

    1968-01-01

    Comfortable, inexpensive nosepiece respiration monitor produces rapid response signals to most conventional high impedance medical signal conditioners. The monitor measures respiration in a manner that produces a large signal with minimum delay.

  11. Respirator Fact Sheet

    MedlinePlus

    ... it last? That depends on how much filtering capacity the respirator has and the amount of hazard ... and it will vary by each respirator model's capacities. That's why your emergency plan must include some ...

  12. 174 Reduction in Allergic Rhinitis Index by Decreasing Aero-Allergens and Malodor Causing Volatile Organic Compounds by Luna Air Purifiers Using Photo-Catalytic Oxidation (PCO) Technology

    PubMed Central

    Ghosh, Nabarun; Aguaiza, Cristina; Guzman, Alicia; Chudasama, Jay; Bennert, Jeff; Das, A. B.

    2012-01-01

    Background The quality of the environment within buildings is a topic of major importance for public health. Breathing pure and clean air allows us to think more clearly, sleep more soundly, and stay healthier. Studies show that we receive 56% of our energy from the air we breathe, more than from water and food combined. On average we breathe 37 pounds of air a day. It has been established that the use of negative ions in a purification system is an effective means of eradicating aeroallergens in room air. Methods The wall-mount, Inducts and Mobile Sanifier air purification units of Luna are designed to sanitize air, to kill surface mold, bacteria, and viruses in areas up to 26,000 cubic feet. Samples were collected from the clinic rooms to analyze the VOC concentrations using the Luna air purifiers to detect the efficiency in reducing the VOCs in the indoor air. We analyzed the aroallergens and VOCs prevalent in the indoor air in the clinics at the Coulter Animal Hospital, Amarillo, Texas. The data were correlated to the inhalant allergy index before and after running air purifiers that use PCO technology. Results Samples from the clinic rooms to analyze the VOC concentrations using the Luna air purifiers to detect the efficiency in reducing the VOCs in the indoor air. The SKC Pocket Pump and thermal desorption tubes were used to obtain the samples from the indoor air. Pumps were set on 200 mL/min as air flow to estimate the concentration of Acetic acid, Isobutyric acid, Butyric acid, Isovaleric acid, Valeric acid, Hexanoic acid, Phenol, p-cresol, 4-ethyl, 2-amino, Indole, and Skatole. All desorption tube samples were analyzed using a Markes UNITY and Markes Ultra automated thermal desorber (ATD) and a Varian 3800/Saturn 2000 GC with a MS. Slides with double sticky tape were exposed to room air stained with 2% safranin and were observed using a BX-40 Olympus microscope with DP-70 and Image Pro Plus software. Conclusions The data were correlated with the

  13. Respiratory protection as a function of respirator fitting characteristics and fit-test accuracy.

    PubMed

    Campbell, D L; Coffey, C C; Lenhart, S W

    2001-01-01

    The fitting characteristics of particulate respirators are no longer assessed in the National Institute for Occupational Safety and Health respirator certification program. It is important for respirator program administrators to understand the implications of that change and the additional burden it may impose. To address that issue, a typical respirator fit-testing program is analyzed using a mathematical model that describes the effectiveness of a fit-testing program as a function of the fitting characteristics of the respirator and the accuracy of the fittesting method. The model is used to estimate (1) the respirator assignment error, the percentage of respirator wearers mistakenly assigned an ill-fitting respirator; (2) the number of fit-test trials necessary to qualify a group of workers for respirator use; and (3) the number of workers who will fail the fit-test with any candidate respirator model and thereby fail to qualify for respirator use. Using data from previous studies, the model predicts respirator assignment errors ranging from 0 to 20%, depending on the fitting characteristics of the respirator models selected and the fit-testing method used. This analysis indicates that when respirators do not necessarily have good fitting characteristics, respirator program administrators should exercise increased care in the selection of respirator models and increased care in fit-testing. Also presented are ways to assess the fitting characteristics of candidate respirator models by monitoring the first-time fit-testing results. The model demonstrates that significant public health and economic benefits can result when only respirators having good fitting characteristics are purchased and respirators are assigned to workers using highly accurate fit-testing methods.

  14. Speech and respiration.

    PubMed

    Conrad, B; Schönle, P

    1979-04-12

    This investigation deals with the temporal aspects of air volume changes during speech. Speech respiration differs fundamentally from resting respiration. In resting respiration the duration and velocity of inspiration (air flow or lung volume change) are in a range similar to that of expiration. In speech respiration the duration of inspiration decreases and its velocity increases; conversely, the duration of expiration increases and the volume of air flow decreases dramatically. The following questions arise: are these two respiration types different entities, or do they represent the end points of a continuum from resting to speech respiration? How does articulation without the generation of speech sound affect breathing? Does (verbalized?) thinking without articulation or speech modify the breathing pattern? The main test battery included four tasks (spontaneous speech, reading, serial speech, arithmetic) performed under three conditions (speaking aloud, articulating subvocally, quiet performance by tryping to exclusively 'think' the tasks). Respiratory movements were measured with a chest pneumograph and evaluated in comparison with a phonogram and the identified spoken text. For quiet performance the resulting respiratory time ratio (relation of duration of inspiration versus expiration) showed a gradual shift in the direction of speech respiration--the least for reading, the most for arithmetic. This change was even more apparent for the subvocal tasks. It is concluded that (a) there is a gradual automatic change from resting to speech respiration and (b) the degree of internal verbalization (activation of motor speech areas) defines the degree of activation of the speech respiratory pattern.

  15. Respiration in Aquatic Insects.

    ERIC Educational Resources Information Center

    MacFarland, John

    1985-01-01

    This article: (1) explains the respiratory patterns of several freshwater insects; (2) describes the differences and mechanisms of spiracular cutaneous, and gill respiration; and (3) discusses behavioral aspects of selected aquatic insects. (ML)

  16. SYSTEMIC TRANSLOCATION OF PARTICULATE MATTER-ASSOCIATED METALS FOLLOWING A SINGLE INTRATRACHEAL INSTILLATION IN RATS

    EPA Science Inventory

    Respirable ambient particulate matter (PM) exposure has been associated with an increased risk of cardiovascular disease. Direct translocation of PM associated metals from the lungs into systemic circulation may be partly responsible. We measured elemental content of lungs, pla...

  17. Testing of chemically treated adsorbent air purifiers

    SciTech Connect

    Kelly, T.J. . Dept. of Atmospheric Science and Applied Technology); Kinkead, D.A. )

    1993-07-01

    New highly sensitive continuous monitors permit testing of air filters at parts-per-billion contaminant concentrations. This article describes testing of air purification filters intended for use in the National Archives 2 building in College Park, Maryland, using a test procedure that simulates the actual conditions of use. This test demonstrates both the effectiveness of the adsorbers at low contaminant levels, and the capability of existing instruments for conducting such tests. ASHRAE TC 2.3 (Gaseous Air Contaminants and Gas Contaminant Removal Equipment) is currently sponsoring research projects (follow-on studies to ASHRAE Project RP-674) aimed at developing a standard that will test and rate the performance of different types of gas phase air purification equipment at low concentrations. The work detailed in this article represents a first of this type of testing and a technical benchmark that may aid in the further development of ASHRAE gas phase performance standards.

  18. 77 FR 68784 - Standard Test Procedures Approval Process for Respirators To Be Used in Wildland Fire-Fighting...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-16

    ... developed respiratory protection for this occupational setting, firefighters battling wild fires often... Respirators To Be Used in Wildland Fire-Fighting Operations; Standard Test Procedures for Composite Multi-Gas and Particulate Protection and Approval Process for Respirators To Be Used in Wildland...

  19. Protection of firefighters against combustion aerosol particles: simulated workplace protection factor of a half-mask respirator (pilot study).

    PubMed

    Dietrich, James; Yermakov, Michael; Reponen, Tiina; Kulkarni, Pramod; Qi, Chaolong; Grinshpun, Sergey A

    2015-01-01

    The present pilot study investigated the penetration of ultrafine particles originated by combustion of different materials into elastomeric half-mask respirators equipped with two P100 filters. We determined the Simulated Workplace Protection Factor (SWPF) for 11 firefighters wearing elastomeric half-mask respirators and performing activities simulating those conducted during fire overhaul operations. The tests were performed in a controlled laboratory setting. A newly-developed battery-operated Portable Aerosol Mobility Spectrometer (PAMS) was used to measure size-resolved aerosol particle concentrations outside (C(out)) and inside (Cin) of an air-purifying respirator donned on a firefighter, and the SWPF was calculated as C(out)/C(in). Based on the total aerosol concentration, the "total" SWPF ranged from 4,222 (minimum) to 35,534 (maximum) with values falling primarily in a range from 11,171 (25 percentile) to 26,604 (75 percentile) and a median value being ≈15,000. This is consistent with the recently reported fit factor (FF) data base.((1)) The size-resolved SWPF data revealed a dependency on the particle size. It was concluded that a portable device such as PAMS can be used on firefighters during overhaul operations (as well as on other workers wearing elastomeric half-mask respirators) to monitor the aerosol concentrations in real time and ultimately help prevent overexposure.

  20. Workplace Breathing Rates: Defining Anticipated Values and Ranges for Respirator Certification Testing

    DTIC Science & Technology

    2004-09-01

    performance tests most affected by airflow rate are filter gas-life capacity, particulate filter efficiency, and respirator breathing resistances...efficacy when tested under standard laboratory protocols. The relevance and adequacy of airflow rates used in respirator certification testing has been... airflow conditions. NIOSH-approved non-powered APR chemical cartridges and canisters (filter systems) are tested at a constant flow rate of 64 liters

  1. 40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...,2-dihydro- (PMNs P-06-1 and P-06-166; CAS No. 930-33-6) is subject to reporting under this section...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a...

  2. 40 CFR 721.10029 - Isocyanate compound, modified with methoxysilane (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... generically as isocyanate compound, modified with methoxysilane (PMN P-01-918) is subject to reporting under... absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters; supplied-air respirator operated in...

  3. 40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...,2-dihydro- (PMNs P-06-1 and P-06-166; CAS No. 930-33-6) is subject to reporting under this section...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a...

  4. 40 CFR 721.10029 - Isocyanate compound, modified with methoxysilane (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... generically as isocyanate compound, modified with methoxysilane (PMN P-01-918) is subject to reporting under... absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters; supplied-air respirator operated in...

  5. 40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...,2-dihydro- (PMNs P-06-1 and P-06-166; CAS No. 930-33-6) is subject to reporting under this section...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a...

  6. 40 CFR 721.10077 - 3H-1,2,4-Triazol-3-one, 1,2-dihydro-.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...,2-dihydro- (PMNs P-06-1 and P-06-166; CAS No. 930-33-6) is subject to reporting under this section...-fitting respirator equipped with N100 (if aerosols absent), R100, or P100 filters (either half- or full... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a...

  7. 40 CFR 721.10029 - Isocyanate compound, modified with methoxysilane (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... generically as isocyanate compound, modified with methoxysilane (PMN P-01-918) is subject to reporting under... absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters; supplied-air respirator operated in...

  8. 42 CFR 84.173 - Harnesses; installation and construction; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Harnesses; installation and construction; minimum... DEVICES Non-Powered Air-Purifying Particulate Respirators § 84.173 Harnesses; installation and... harness designed and constructed to hold the components of the respirator in position against the...

  9. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  10. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  11. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  12. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  13. 42 CFR 84.172 - Breathing tubes; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Breathing tubes; minimum requirements. 84.172... Air-Purifying Particulate Respirators § 84.172 Breathing tubes; minimum requirements. Flexible breathing tubes used in conjunction with respirators shall be designed and constructed to prevent:...

  14. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting... demand or continuous flow mode and equipped with a hood or helmet, or tight-fitting facepiece...

  15. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting... demand or continuous flow mode and equipped with a hood or helmet, or tight-fitting facepiece...

  16. 40 CFR 721.10199 - Substituted aliphatic amine (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., tight-fitting full-face respirator equipped with the appropriate combination cartridges, cartridges...-specific cartridge) and should include a particulate filter (N100 if oil aerosols are absent, R100, or P100); powered air-purifying respirator equipped with a tight-fitting facepiece (full-face) and the...

  17. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting... demand or continuous flow mode and equipped with a hood or helmet, or tight-fitting facepiece...

  18. 40 CFR 721.10101 - Copolymer of alkyl acrylate and ethyleneglycol dimethacrylate (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half... Efficiency Particulate Air (HEPA) filters; powered air-purifying respirator equipped with a tight-fitting... demand or continuous flow mode and equipped with a hood or helmet, or tight-fitting facepiece...

  19. THE ASSOCIATION OF EXPOSURE TO PARTICULATE MATTER AND RELATED AIR POLLUTANTS WITH SPECIFIC HEALTH EFFECTS IN HEALTHY HIGHWAY PATROL OFFICERS

    EPA Science Inventory

    Estimated exposures to ambient respirable particulate matter (PM) and related co-pollutants have been statistically associated with mortality and morbidity in epidemiological studies conducted throughout the world. Although some subpopulations (e.g., asthmatics; elderly, pulmonar...

  20. Respiratory protection against Mycobacterium tuberculosis: quantitative fit test outcomes for five type N95 filtering-facepiece respirators.

    PubMed

    Lee, Kiyoung; Slavcev, Andrea; Nicas, Mark

    2004-01-01

    respirator penetration (primarily due to faceseal leakage) of .04 and 0.3, respectively. The respirator with the highest overall pass rate (95%) reduced M. tb infection risk by 95%, while the respirator with the lowest pass rate (8%) reduced M. tb infection risk by only 70%. To promote the marketing of respirators that will successfully fit the highest proportion of wearers, and to increase protection for workers who might use respirators without the benefit of being fit tested, we recommend that fit testing be part of the NIOSH certification process for negative-pressure air-purifying respirators with tightly fitting facepieces. At a minimum, we recommend that respirator manufacturers generate and provide pass rate data to assist in selecting candidate respirators. In any event, program managers can initially select candidate respirators by comparing quantitative fit tests for a representative sample of their employee population.

  1. Plankton respiration in the Eastern Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Robinson, Carol; Serret, Pablo; Tilstone, Gavin; Teira, Eva; Zubkov, Mikhail V.; Rees, Andrew P.; Woodward, E. Malcolm S.

    2002-05-01

    Concurrent measurements of dark community respiration (DCR), gross production (GP), size fractionated primary production ( 14C PP), nitrogen uptake, nutrients, chlorophyll a concentration, and heterotrophic and autotrophic bacterial abundance were collected from the upper 200 m of a latitudinal (32°S-48°N) transect in the Eastern Atlantic Ocean during May/June 1998. The mean mixed layer respiration rate was 2.5±2.1 mmol O 2 m -3 d -1 ( n=119) for the whole transect, 2.2±1.1 mmol O 2 m -3 d -1 ( n=32) in areas where chlorophyll a was <0.5 mg m -3 and 1.5±0.7 mmol O 2 m -3 d -1 ( n=10) where chlorophyll a was <0.2 mg m -3. These values lie within the range of published data collected in comparable waters, they co-vary with indicators of heterotrophic and autotrophic biomass (heterotrophic bacterial abundance, chlorophyll a concentration, beam attenuation and particulate organic carbon concentration) and they can be reconciled with accepted estimates of total respiratory activity. The mean and median respiratory quotient (RQ), calculated as the ratio of dissolved inorganic carbon production to dissolved oxygen consumption, was 0.8 ( n=11). At the time of the study, plankton community respiration exceeded GP in the picoautotroph dominated oligotrophic regions (Eastern Tropical Atlantic [15.5°S-14.2°N] and North Atlantic Subtropical Gyre [21.5-42.5°N]), which amounted to 50% of the stations sampled along the 12,100 km transect. These regions also exhibited high heterotrophic: autotrophic biomass ratios, higher turnover rates of phytoplankton than of bacteria and low f ratios. However, the carbon supply mechanisms required to sustain the rates of respiration higher than GP could not be fully quantified. Future research should aim to determine the temporal balance of respiration and GP together with substrate supply mechanisms in these ocean regions.

  2. Organic fuels for respiration in tropical river systems

    NASA Astrophysics Data System (ADS)

    Ward, N.; Keil, R. G.; Richey, J. E.; Krusche, A. V.; Medeiros, P. M.

    2011-12-01

    Watershed-derived organic matter is thought to provide anywhere from 30-90% of the organic matter in rivers (e.g. Hernes et al 2008; Spencer et al 2010). The most abundant biochemicals on land are cellulose, hemicelluloses, and lignin. Combined, they represent as much as 80% of the biomass in a typical forest and as much as 60% of the biomass in a typical field (natural or crop)(Bose et al 2009; Bridgeman et al., 2007; Hu and Zu 2006; Martens et al 2004). They are often assumed to be refractory and hard to degrade, but this assumption is at odds with virtually all observations: soils and marine sediments are not accumulating vast amounts of these compounds (Hedges and Oades, 1997), and degradation experiments suggest that cellulose, hemicelluloses and lignin are reactive and likely to be important fuels for respiration (Benner, 1991; Haddad et al, 1992; Dittmar et al, 2001; Otto and Simpson, 2006). During several trips to the lower Amazon River, incubation experiments were performed in which the biological degradation of lignin phenols was observed in order to assess the contribution of microbial respiration of terrestrially-derived macromolecules to gross respiration and CO2 gas evasion rates. Both particulate and dissolved lignin concentrations decreased by ~40% after being incubated in the dark for 5-7 days, indicating a turnover time of the entire lignin pool of 12-18 days. These results shift the paradigm that lignocellulose derived OM is highly recalcitrant, and indicate that microbial respiration of lignocellulose may play a larger role in total respiration rates/CO2 outgassing than previously thought. A simple mass balance calculation was done to test whether microbial degradation alone could explain the lignin data observed in the field. First, a theoretical particulate lignin concentration for Macapa was calculated based on the observed data at Obidos. The measured rate of particulate lignin degradation was multiplied by the transit time of water from

  3. Hybrid respiration-signal conditioner

    NASA Technical Reports Server (NTRS)

    Rinard, G. A.; Steffen, D. A.; Sturm, R. E.

    1979-01-01

    Hybrid impedance-pneumograph and respiration-rate signal conditioner element of hand-held vital signs monitor measures changes in impedance of chest during breathing cycle and generates analog respiration signal as output along with synchronous square wave that can be monitored by breath-rate processor.

  4. 42 CFR 84.1140 - Dust, fume, and mist respirators; performance requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High...

  5. 42 CFR 84.1140 - Dust, fume, and mist respirators; performance requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High...

  6. 42 CFR 84.1140 - Dust, fume, and mist respirators; performance requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High...

  7. 42 CFR 84.1140 - Dust, fume, and mist respirators; performance requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High...

  8. Health effects of particulate air pollution: time for reassessment?

    PubMed Central

    Pope, C A; Bates, D V; Raizenne, M E

    1995-01-01

    Numerous studies have observed health effects of particulate air pollution. Compared to early studies that focused on severe air pollution episodes, recent studies are more relevant to understanding health effects of pollution at levels common to contemporary cities in the developed world. We review recent epidemiologic studies that evaluated health effects of particulate air pollution and conclude that respirable particulate air pollution is likely an important contributing factor to respiratory disease. Observed health effects include increased respiratory symptoms, decreased lung function, increased hospitalizations and other health care visits for respiratory and cardiovascular disease, increased respiratory morbidity as measured by absenteeism from work or school or other restrictions in activity, and increased cardiopulmonary disease mortality. These health effects are observed at levels common to many U.S. cities including levels below current U.S. National Ambient Air Quality Standards for particulate air pollution. Images Figure 1. PMID:7656877

  9. From breathing to respiration.

    PubMed

    Fitting, Jean-William

    2015-01-01

    The purpose of breathing remained an enigma for a long time. The Hippocratic school described breathing patterns but did not associate breathing with the lungs. Empedocles and Plato postulated that breathing was linked to the passage of air through pores of the skin. This was refuted by Aristotle who believed that the role of breathing was to cool the heart. In Alexandria, breakthroughs were accomplished in the anatomy and physiology of the respiratory system. Later, Galen proposed an accurate description of the respiratory muscles and the mechanics of breathing. However, his heart-lung model was hampered by the traditional view of two non-communicating vascular systems - veins and arteries. After a period of stagnation in the Middle Ages, knowledge progressed with the discovery of pulmonary circulation. The comprehension of the purpose of breathing progressed by steps thanks to Boyle and Mayow among others, and culminated with the contribution of Priestley and the discovery of oxygen by Lavoisier. Only then was breathing recognized as fulfilling the purpose of respiration, or gas exchange. A century later, a controversy emerged concerning the active or passive transfer of oxygen from alveoli to the blood. August and Marie Krogh settled the dispute, showing that passive diffusion was sufficient to meet the oxygen needs.

  10. 78 FR 18601 - Respirator Certification Fees; Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ... HUMAN SERVICES Centers for Disease Control and Prevention Respirator Certification Fees; Public Meeting... stakeholders to present information the impact of an increase on respirator fees on individual respirator... in respirator certification and approval fees on individual respirator manufacturers, the...

  11. Diesel particulate control

    SciTech Connect

    Bertelsen, F.I. )

    1988-01-01

    Diesel particulates, because of their chemical composition and extremely small size, have raised health and welfare issues. Health experts have expressed concern that they contribute to or aggravate chronic lung diseases such as asthma, bronchitis and emphysema, and there is the lingering issue about the potential cancer risk from exposure to diesel particulate. Diesel particulates impair visibility, soil buildings, contribute to structural damage through corrosion and give off a pungent odor. Diesel trucks, buses and cars together are such a significant and growing source of particulate emissions. Such vehicles emit 30 to 70 times more particulate matter than gasoline vehicles equipped with catalytic converters. Diesel engines currently power the majority of larger trucks and buses. EPA predicted that, if left uncontrolled, diesel particulate from motor vehicles would increase significantly. Diesel particulate emissions from motor vehicles are particularly troublesome because they frequently are emitted directly into the breathing zone where we work and recreate. The U.S. Congress recognized the risks posed by diesel particulate and as part of the 1977 Clean Air Act Amendments established specific, technology-forcing requirements for controlling these emissions. The U.S. Environmental Protection Agency (EPA) in 1980 established particulate standards for automobiles and light trucks and in 1985, heavy trucks and buses. California, concerned that EPA standards would not adequately protect its citizens, adopted its own set of standards for passenger cars and light trucks. This paper discusses emerging technologies proposed to address the problem.

  12. Particulate Air Pollution: The Particulars

    ERIC Educational Resources Information Center

    Murphy, James E.

    1973-01-01

    Describes some of the causes and consequences of particulate air pollution. Outlines the experimental procedures for measuring the amount of particulate materials that settles from the air and for observing the nature of particulate air pollution. (JR)

  13. Pitch based foam with particulate

    DOEpatents

    Klett, James W.

    2001-01-01

    A thermally conductive, pitch based foam composite having a particulate content. The particulate alters the mechanical characteristics of the foam without severely degrading the foam thermal conductivity. The composite is formed by mixing the particulate with pitch prior to foaming.

  14. Particulate matter fugitive dusts

    SciTech Connect

    Not Available

    1988-01-01

    Topics covered in this conference include: Review of EPA's cost/benefit analysis for additional regulation of surface coal mines; Particulate monitoring on the Kilauea East Rift, Hawaii, and The MEDUSA sampling system: case histories in the measurement of particulate matter with wide spectrum analysis.

  15. Airborne particulate discriminator

    DOEpatents

    Creek, Kathryn Louise; Castro, Alonso; Gray, Perry Clayton

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  16. Long-term measurements of respirable sulfates and particles inside and outside homes

    NASA Astrophysics Data System (ADS)

    Spengler, J. D.; Dockery, D. W.; Turner, W. A.; Wolfson, J. M.; Ferris, B. G.

    The results of extensive indoor and outdoor monitoring for respirable size particles and the sulfate fraction of these particles are reported. These air pollution measurements were obtained in conjunction with an epidemiologic study in six U.S. cities: Portage, Wisconsin; Topeka, Kansas; Kingston/Harriman, Tennessee; Watertown, Massachusetts; St. Louis, Missouri: and Steubenville, Ohio. The major source of indoor particulate matter is cigarette smoke, which contributes approximately 20 μm -3 to the indoor concentrations for each smoker. Even in homes without smokers, indoor particle concentrations equal or exceed outdoor levels. The indoor respirable sulfate concentrations are consistently lower than outdoor concentrations.

  17. Electrical stimulation to restore respiration.

    PubMed

    Creasey, G; Elefteriades, J; DiMarco, A; Talonen, P; Bijak, M; Girsch, W; Kantor, C

    1996-04-01

    Electrical stimulation has been used for over 25 years to restore breathing to patients with high quadriplegia causing respiratory paralysis and patients with central alveolar hypoventilation. Three groups have developed electrical pacing systems for long-term support of respiration in humans. These systems consist of electrodes implanted on the phrenic nerves, connected by leads to a stimulator implanted under the skin, and powered and controlled from a battery-powered transmitter outside the body. The systems differ principally in the electrode design and stimulation waveform. Approximately 1,000 people worldwide have received one of the three phrenic pacing devices, most with strongly positive results: reduced risk of tracheal problems and chronic infection, the ability to speak and smell more normally, reduced risk of accidental interruption of respiration, greater independence, and reduced costs and time for ventilatory care. For patients with partial lesions of the phrenic nerves, intercostal muscle stimulation may supplement respiration.

  18. [Dark respiration of terrestrial vegetations: a review].

    PubMed

    Sun, Jin-Wei; Yuan, Feng-Hui; Guan, De-Xin; Wu, Jia-Bing

    2013-06-01

    The source and sink effect of terrestrial plants is one of the hotspots in terrestrial ecosystem research under the background of global change. Dark respiration of terrestrial plants accounts for a large fraction of total net carbon balance, playing an important role in the research of carbon cycle under global climate change. However, there is little study on plant dark respiration. This paper summarized the physiological processes of plant dark respiration, measurement methods of the dark respiration, and the effects of plant biology and environmental factors on the dark respiration. The uncertainty of the dark respiration estimation was analyzed, and the future hotspots of related researches were pointed out.

  19. 40 CFR 721.10002 - 2-Thiazolidinone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    .... (1) The chemical substance identified as 2-thiazolidinone (PMN P-97-415; CAS No. 2682-49-7) is...- or full-face) equipped with N100 (if aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a loose-fitting hood or helmet and High Efficiency Particulate Air (HEPA)...

  20. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-dihydrazide (PMNs P-01-759 and P-05-555; CAS No. 4080-98-2) is subject to reporting under this section for the... equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  1. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-dihydrazide (PMNs P-01-759 and P-05-555; CAS No. 4080-98-2) is subject to reporting under this section for the... equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  2. 40 CFR 721.10002 - 2-Thiazolidinone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    .... (1) The chemical substance identified as 2-thiazolidinone (PMN P-97-415; CAS No. 2682-49-7) is...- or full-face) equipped with N100 (if aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a loose-fitting hood or helmet and High Efficiency Particulate Air (HEPA)...

  3. 40 CFR 721.10057 - Dodecanedioic acid, 1, 12-dihydrazide.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...-dihydrazide (PMNs P-01-759 and P-05-555; CAS No. 4080-98-2) is subject to reporting under this section for the... equipped with N100 (if oil aerosols absent), R100, or P100 filters; powered air-purifying respirator equipped with a tight-fitting full facepiece and High Efficiency Particulate Air (HEPA) filters;...

  4. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  5. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  6. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  7. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  8. 42 CFR 84.178 - Head harnesses; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Head harnesses; minimum requirements. 84.178... Air-Purifying Particulate Respirators § 84.178 Head harnesses; minimum requirements. (a) All facepieces shall be equipped with head harnesses designed and constructed to provide adequate tension...

  9. Soil Respiration - A Geochemist's Perspective

    NASA Astrophysics Data System (ADS)

    Van Cappellen, P.

    2015-12-01

    Soil biogeochemistry is largely driven by the decomposition of plant-derived organic matter by soil microorganisms. In addition to its effects on water quality and soil fertility, the decomposition of organic matter couples soil processes to climate, via the production and emission of greenhouse gases. In this presentation, I will review a number of key factors controlling the rate of decomposition of soil organic matter. In particular, I will discuss the importance of the spatial and temporal variations in redox conditions as drivers of soil respiration. The discussion will highlight the limitations of current soil respiration models based on partitioning soil organic matter in a finite number of pools of different degradability. In order to predict the sensitivity of soil respiration to anthropogenic pressures - including climate warming - it is crucial to relate the apparent degradability of soil organic matter to the geochemical and hydrological dynamics of the soil environment. Overall, there remains much scope for geochemists to help develop more robust, process-based, representations of soil respiration in global carbon models and climate predictions.

  10. Fluidizing device for solid particulates

    DOEpatents

    Diebold, J.P.; Scahill, J.W.

    A flexible whip suspended in a hopper is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

  11. Comparative inflammatory effects of differential particulate matter species in an OVA-sensitization and challenge model

    EPA Science Inventory

    Exposure to respirable ambient particulate matter (APM) provokes allergic immunity that may also occur on exposure to environmental diesel exhaust particles (eDEP) or emission source DEP (cDEP). Our hypothesis tested whether APM, eDEP or cDEP provide immune adjuvancy in an antige...

  12. Modeling of Particulate Emissions

    DTIC Science & Technology

    2011-12-01

    coagulation oxidation.... carbonization 14 Modeling Particulate Emissions Soot Formation Kinetics 2 1016 1 ]HC[kdt dS = Inception: Dimerization of...simulated with peak size for surface growth Sectional Conservation Equation 16 Modeling Particulate Emissions Soot Kinetics Based on OH, O2 and...and empirical tuning to NOx, CO emissionsFuel-spray shear layer Recirculation zones Quench zones Burn-out zones Full set of reaction kinetics and

  13. Reduction of respirable silica following the introduction of water spray applications in Indian stone crusher mills.

    PubMed

    Gottesfeld, Perry; Nicas, Mark; Kephart, John W; Balakrishnan, Kalpana; Rinehart, Richard

    2008-01-01

    Respirable crystalline silica dust generated during stone crushing operations has been linked to chronic lung disease and increased risk of tuberculosis. In India, most stone crushing mills operate without any dust control or containment systems. This investigation in the Khurda District of Orissa demonstrated a reduction in respirable particulate mass following the application of a fine mist of water. Average respirable quartz and cristobalite levels declined 82% and 69%, respectively, after water spray controls were installed. This finding suggests that relatively inexpensive modifications that are available in the local market can be effective at reducing silica exposures. Although average exposure levels, particularly during the dry season, may exceed the Permissible Exposure Limit for silica, the overall reductions observed were substantial. Widespread adoption of this simple control technology by stone crushers in India could have a positive public health impact.

  14. Airborne endotoxin concentrations in indoor and outdoor particulate matter and their predictors in an urban city.

    PubMed

    Yoda, Y; Tamura, K; Shima, M

    2017-02-04

    Endotoxins are an important biological component of particulate matter and have been associated with adverse effects on human health. There have been some recent studies on airborne endotoxin concentrations. We collected fine (PM2.5 ) and coarse (PM10-2.5 ) particulate matter twice on weekdays and weekends each for 48 hour, inside and outside 55 homes in an urban city in Japan. Endotoxin concentrations in both fractions were measured using the kinetic Limulus Amebocyte Lysate assay. The relationships between endotoxin concentrations and household characteristics were evaluated for each fraction. Both indoor and outdoor endotoxin concentrations were higher in PM2.5 than in PM10-2.5 . In both PM2.5 and PM10-2.5 , indoor endotoxin concentrations were higher than outdoor concentrations, and the indoor endotoxin concentrations significantly correlated with outdoor concentrations in each fraction (R(2) =0.458 and 0.198, respectively). Indoor endotoxin concentrations in PM2.5 were significantly higher in homes with tatami or carpet flooring and in homes with pets, and lower in homes that used air purifiers. Indoor endotoxin concentrations in PM10-2.5 were significantly higher in homes with two or more children and homes with tatami or carpet flooring. These results showed that the indoor endotoxin concentrations were associated with the household characteristics in addition to outdoor endotoxin concentrations.

  15. [Research advances in forest soil respiration].

    PubMed

    Luan, Junwei; Xiang, Chenghua; Luo, Zongshi; Gong, Yuanbo

    2006-12-01

    Among the methods of measuring forest soil respiration, infrared CO2 analysis is the optimal one so far. Comparing with empirical model, the process-based model in simulating the production and transportation of soil CO2 has the advantage of considering the biological and physical processes of soil respiration. Generally, soil respiration is positively correlated with soil temperature and moisture, but there are still many uncertainties about the relationships between soil respiration and forest management activities such as firing, cutting, and fertilization. The relationships of soil respiration with vegetation type and soil microbial biomass, as well as the spatial heterogeneity of soil respiration, are the hotspots in recent researches. Some issues and future development in forest soil respiration research were discussed in this paper.

  16. Mesoporous silica nanoparticles inhibit cellular respiration.

    PubMed

    Tao, Zhimin; Morrow, Matthew P; Asefa, Tewodros; Sharma, Krishna K; Duncan, Cole; Anan, Abhishek; Penefsky, Harvey S; Goodisman, Jerry; Souid, Abdul-Kader

    2008-05-01

    We studied the effect of two types of mesoporous silica nanoparticles, MCM-41 and SBA-15, on mitochondrial O 2 consumption (respiration) in HL-60 (myeloid) cells, Jurkat (lymphoid) cells, and isolated mitochondria. SBA-15 inhibited cellular respiration at 25-500 microg/mL; the inhibition was concentration-dependent and time-dependent. The cellular ATP profile paralleled that of respiration. MCM-41 had no noticeable effect on respiration rate. In cells depleted of metabolic fuels, 50 microg/mL SBA-15 delayed the onset of glucose-supported respiration by 12 min and 200 microg/mL SBA-15 by 34 min; MCM-41 also delayed the onset of glucose-supported respiration. Neither SBA-15 nor MCM-41 affected cellular glutathione. Both nanoparticles inhibited respiration of isolated mitochondria and submitochondrial particles.

  17. Natural organic matter as electron acceptor: experimental evidence for its important role in anaerobic respiration

    NASA Astrophysics Data System (ADS)

    Lau, Maximilian Peter; Sander, Michael; Gelbrecht, Jörg; Hupfer, Michael

    2014-05-01

    Microbial respiration is a key driver of element cycling in oxic and anoxic environments. Upon depletion of oxygen as terminal electron acceptor (TEA), a number of anaerobic bacteria can employ alternative TEA for intracellular energy generation. Redox active quinone moieties in dissolved organic matter (DOM) are well known electron acceptors for microbial respiration. However, it remains unclear whether quinones in adsorbed and particulate OM accept electrons in a same way. In our studies we aim to understand the importance of natural organic matter (NOM) as electron acceptors for microbial energy gain and its possible implications for methanogenesis. Using a novel electrochemical approach, mediated electrochemical reduction and -oxidation, we can directly quantify reduced hydroquinone and oxidized quionone moieties in dissolved and particulate NOM samples. In a mesocosm experiment, we rewetted sediment and peat soil and followed electron transfer to the inorganic and organic electron acceptors over time. We found that inorganic and organic electron acceptor pools were depleted over the same timescales. More importantly, we showed that organic, NOM-associated electron accepting moieties represent as much as 21 40% of total TEA inventories. These findings support earlier studies that propose that the reduction of quinone moieties in particulate organic matter competitively suppresses methanogenesis in wetland soils. Our results indicate that electron transfer to organic, particulate TEA in inundated ecosystems has to be accounted for when establishing carbon budgets in and projecting greenhouse gas emissions from these systems.

  18. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Stanley Miller; Rich Gebert; William Swanson

    1999-11-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the US Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in a manner that has not been done before. The AHPC concept consists of a combination of fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two collection methods, both in the particulate collection step and in the transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emission with conventional ESPs, and it solves the problem of reentrainment and collection of dust in conventional baghouses. The AHPC is currently being tested at the 2.7-MW scale at the Big Stone power station.

  19. Void/particulate detector

    DOEpatents

    Claytor, Thomas N.; Karplus, Henry B.

    1985-01-01

    Voids and particulates are detected in a flowing stream of fluid contained in a pipe by a detector which includes three transducers spaced about the pipe. A first transducer at a first location on the pipe transmits an ultrasonic signal into the stream. A second transducer detects the through-transmission of the signal at a second location and a third transducer at a third location upstream from the first location detects the back-scattering of the signal from any voids or particulates. To differentiate between voids and particulates a fourth transducer is positioned at a fourth location which is also upstream from the first location. The back-scattered signals are normalized with the through-transmission signal to minimize temperature fluctuations.

  20. Microwave regenerated particulate trap

    SciTech Connect

    McDonald, A.C. Jr.; Yonushonis, T.M.; Haberkamp, W.C.; Mako, F.; Len, L.K,; Silberglitt, R.; Ahmed, I.

    1997-12-31

    It has been demonstrated that a fibrous particulate filter can extract particulate matter from the diesel exhaust. However, additional engineering efforts remains to achieve the design target of 90%. It has also be shown that with minor modifications magnetrons produced for home ovens can endure a simulated diesel operating environment. Much work remains to develop a robust product ready to complete extensive engine testing and evaluation. These efforts include: (1) additional environmental testing of magnetrons; (2) vibration testing of the filter in the housing; (3) evaluating alternative methods/designs to seal the center bore; and (4) determining the optimum coating thickness that provides sufficient structural integrity while maintaining rapid heating rates.

  1. Ultrafine and respirable particle exposure during vehicle fire suppression.

    PubMed

    Evans, Douglas E; Fent, Kenneth W

    2015-10-01

    Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters' potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator's shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 10(7) particles per cm(3), 170 mg m(-3) respirable particle mass, 4700 μm(2) cm(-3) active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 10(4) particles per cm(3), 0.36 mg m(-3) respirable particle mass, 92 μm(2) cm(-3) active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 10(5) particles per cm(3), 2.7 mg m(-3) respirable particle mass, 320 μm(2) cm(-3) active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The

  2. Ultrafine and respirable particle exposure during vehicle fire suppression

    PubMed Central

    Fent, Kenneth W.

    2015-01-01

    Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters’ potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator’s shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 107 particles per cm3, 170 mg m−3 respirable particle mass, 4700 μm2 cm−3 active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 104 particles per cm3, 0.36 mg m−3 respirable particle mass, 92 μm2 cm−3 active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 105 particles per cm3, 2.7 mg m−3 respirable particle mass, 320 μm2 cm−3 active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The wind direction

  3. Fluidizing device for solid particulates

    DOEpatents

    Diebold, J.P.; Scahill, J.W.

    1984-06-27

    A flexible whip or a system of whips with novel attachments is suspended in a hopper and is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

  4. Fluidizing device for solid particulates

    DOEpatents

    Diebold, James P.; Scahill, John W.

    1986-01-01

    A flexible whip or a system of whips with novel attachments is suspended in a hopper and is caused to impact against fibrous and irregularly shaped particulates in the hopper to fluidize the particulates and facilitate the flow of the particulates through the hopper. The invention provides for the flow of particulates at a substantially constant mass flow rate and uses a minimum of energy.

  5. Analysis of microsize particulates

    NASA Technical Reports Server (NTRS)

    Blanchard, M. B.; Farlow, N. H.; Ferry, G. V.

    1972-01-01

    Unique methods for analyzing individual particles ranging in size from 0.01 to 1000 micrometers have been developed for investigation of nature of cosmic dust. Methods are applicable to particulate aerosols and contaminants characteristically encountered in studies of air pollution and in experiments designed to abate pollution.

  6. Validation of Respirator Filter Efficacy

    DTIC Science & Technology

    2007-11-02

    A 1980’ s unpublished ECBC report presented calculations of the required degree of filtration needed to protect a respirator wearer from a given...tested against three bioaerosols ranging in size from 0.69 – 0.88 µm aerodynamic diameter (Mycobacterium abscessus , staphylococcus epidermidis , and 10...and penetration beginning with 99.97% @ 0.3 µm for 10 cm/ s face velocity, a fiber diameter of 0.9 µm, a 0.07 solidity, a 0.3 mm media thickness, and

  7. Soil respiration under climate warming: differential response of heterotrophic and autotrophic respiration.

    PubMed

    Wang, Xin; Liu, Lingli; Piao, Shilong; Janssens, Ivan A; Tang, Jianwu; Liu, Weixing; Chi, Yonggang; Wang, Jing; Xu, Shan

    2014-10-01

    Despite decades of research, how climate warming alters the global flux of soil respiration is still poorly characterized. Here, we use meta-analysis to synthesize 202 soil respiration datasets from 50 ecosystem warming experiments across multiple terrestrial ecosystems. We found that, on average, warming by 2 °C increased soil respiration by 12% during the early warming years, but warming-induced drought partially offset this effect. More significantly, the two components of soil respiration, heterotrophic respiration and autotrophic respiration showed distinct responses. The warming effect on autotrophic respiration was not statistically detectable during the early warming years, but nonetheless decreased with treatment duration. In contrast, warming by 2 °C increased heterotrophic respiration by an average of 21%, and this stimulation remained stable over the warming duration. This result challenged the assumption that microbial activity would acclimate to the rising temperature. Together, our findings demonstrate that distinguishing heterotrophic respiration and autotrophic respiration would allow us better understand and predict the long-term response of soil respiration to warming. The dependence of soil respiration on soil moisture condition also underscores the importance of incorporating warming-induced soil hydrological changes when modeling soil respiration under climate change.

  8. Respirators: Supervisors Self-Study #43442

    SciTech Connect

    Chochoms, Michael

    2016-04-20

    This course, Respirators: Supervisors Self-Study (#43442), addresses training requirements for supervisors of respirator wearers as specified by the American National Standard Institute (ANSI) Standard for Respiratory Protection, ANSI Z88.2, and as incorporated by reference in the Department of Energy (DOE) Worker Health and Safety Rule, 10 Code of Federal Regulations (CFR) 851. This course also presents the responsibilities of supervisors of respirator wearers at Los Alamos National Laboratory (LANL).

  9. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The relative humidity in the...

  10. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The room temperature in the...

  11. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The room temperature in the...

  12. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The room temperature in the...

  13. 42 CFR 84.1147 - Silica mist test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The room temperature in the...

  14. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The relative humidity in the...

  15. 42 CFR 84.1146 - Lead fume test for dust, fume, and mist respirators; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High... minutes each at a continuous airflow rate of 32 liters per minute. (b) The relative humidity in the...

  16. Real-time non-invasive detection of inhalable particulates delivered into live mouse airways.

    PubMed

    Donnelley, Martin; Morgan, Kaye S; Fouras, Andreas; Skinner, William; Uesugi, Kentaro; Yagi, Naoto; Siu, Karen K W; Parsons, David W

    2009-07-01

    Fine non-biological particles small enough to be suspended in the air are continually inhaled as we breathe. These particles deposit on airway surfaces where they are either cleared by airway defences or can remain and affect lung health. Pollutant particles from vehicles, building processes and mineral and industrial dusts have the potential to cause both immediate and delayed health problems. Because of their small size, it has not been possible to non-invasively examine how individual particles deposit on live airways, or to consider how they behave on the airway surface after deposition. In this study, synchrotron phase-contrast X-ray imaging (PCXI) has been utilized to detect and monitor individual particle deposition. The in vitro detectability of a range of potentially respirable particulates was first determined. Of the particulates tested, only asbestos, quarry dust, fibreglass and galena (lead sulfate) were visible in vitro. These particulates were then examined after delivery into the nasal airway of live anaesthetized mice; all were detectable in vivo but each exhibited different surface appearances and behaviour along the airway surface. The two fibrous particulates appeared as agglomerations enveloped by fluid, while the non-fibrous particulates were present as individual particles. Synchrotron PCXI provides the unique ability to non-invasively detect and track deposition of individual particulates in live mouse airways. With further refinement of particulate sizing and delivery techniques, PCXI should provide a novel approach for live animal monitoring of airway particulates relevant to lung health.

  17. Characterization of airborne and bulk particulate from iron and steel manufacturing facilities.

    PubMed

    Machemer, Steven D

    2004-01-15

    Characterization of airborne and bulk particulate material from iron and steel manufacturing facilities, commonly referred to as kish, indicated graphite flakes and graphite flakes associated with spherical iron oxide particles were unique particle characteristics useful in identifying particle emissions from iron and steel manufacturing. Characterization of airborne particulate material collected in receptor areas was consistent with multiple atmospheric release events of kish particles from the local iron and steel facilities into neighboring residential areas. Kish particles deposited in nearby residential areas included an abundance of graphite flakes, tens of micrometers to millimeters in size, and spherical iron oxide particles, submicrometer to tens of micrometers in size. Bulk kish from local iron and steel facilities contained an abundance of similar particles. Approximately 60% of blast furnace kish by volume consisted of spherical iron oxide particles in the respirable size range. Basic oxygen furnace kish contained percent levels of strongly alkaline components such as calcium hydroxide. In addition, concentrations of respirable Mn in airborne particulate in residential areas and at local iron and steel facilities were approximately 1.6 and 53 times the inhalation reference concentration of 0.05 microg/m3 for chronic inhalation exposure of Mn, respectively. Thus, airborne release of kish may pose potential respirable particulate, corrosive, or toxic hazards for human health and/or a corrosive hazard for property and the environment.

  18. High diversity of fungi in air particulate matter

    PubMed Central

    Fröhlich-Nowoisky, Janine; Pickersgill, Daniel A.; Després, Viviane R.; Pöschl, Ulrich

    2009-01-01

    Fungal spores can account for large proportions of air particulate matter, and they may potentially influence the hydrological cycle and climate as nuclei for water droplets and ice crystals in clouds, fog, and precipitation. Moreover, some fungi are major pathogens and allergens. The diversity of airborne fungi is, however, not well-known. By DNA analysis we found pronounced differences in the relative abundance and seasonal cycles of various groups of fungi in coarse and fine particulate matter, with more plant pathogens in the coarse fraction and more human pathogens and allergens in the respirable fine particle fraction (<3 μm). Moreover, the ratio of Basidiomycota to Ascomycota was found to be much higher than previously assumed, which might also apply to the biosphere. PMID:19617562

  19. Ozone Air Purifiers: Can They Improve Asthma Symptoms?

    MedlinePlus

    ... Environmental Protection Agency. https://www.epa.gov/indoor-air-quality-iaq/ozone-generators-are-sold-air-cleaners#generators- ... Environmental Protection Agency. https://www.epa.gov/indoor-air-quality-iaq/residential-air-cleaners-second-edition-summary-available- ...

  20. Rigid particulate matter sensor

    SciTech Connect

    Hall, Matthew

    2011-02-22

    A sensor to detect particulate matter. The sensor includes a first rigid tube, a second rigid tube, a detection surface electrode, and a bias surface electrode. The second rigid tube is mounted substantially parallel to the first rigid tube. The detection surface electrode is disposed on an outer surface of the first rigid tube. The detection surface electrode is disposed to face the second rigid tube. The bias surface electrode is disposed on an outer surface of the second rigid tube. The bias surface electrode is disposed to face the detection surface electrode on the first rigid tube. An air gap exists between the detection surface electrode and the bias surface electrode to allow particulate matter within an exhaust stream to flow between the detection and bias surface electrodes.

  1. Regenerable particulate filter

    DOEpatents

    Stuecker, John N.; Cesarano, III, Joseph; Miller, James E.

    2009-05-05

    A method of making a three-dimensional lattice structure, such as a filter used to remove particulates from a gas stream, where the physical lattice structure is designed utilizing software simulation from pre-defined mass transfer and flow characteristics and the designed lattice structure is fabricated using a free-form fabrication manufacturing technique, where the periodic lattice structure is comprised of individual geometric elements.

  2. Pyrogenic effect of respirable road dust particles

    NASA Astrophysics Data System (ADS)

    Jayawardena, Umesh; Tollemark, Linda; Tagesson, Christer; Leanderson, Per

    2009-02-01

    Because pyrogenic (fever-inducing) compounds on ambient particles may play an important role for particle toxicity, simple methods to measure pyrogens on particles are needed. Here we have used a modified in vitro pyrogen test (IPT) to study the release of interleukin 1β (IL-1β) in whole human blood exposed to respirable road-dust particles (RRDP). Road dusts were collected from the roadside at six different streets in three Swedish cities and particles with a diameter less than 10 μm (RRDP) were prepared by a water sedimentation procedure followed by lyophilisation. RRDP (200 μl of 1 - 106 ng/ml) were mixed with 50 μl whole blood and incubated at 37 °C overnight before IL-1β was analysed with chemiluminescence ELISA in 384-well plates. Endotoxin (lipopolysaccharide from Salmonella minnesota), zymosan B and Curdlan (P-1,3-glucan) were used as positive controls. All RRDP samples had a pyrogenic effect and the most active sample produced 1.6 times more IL-1β than the least active. This formation was of the same magnitude as in samples with 10 ng LPS/ml and was larger than that evoked by zymosan B and Curdlan (by mass basis). The method was sensitive enough to determine formation of IL-1β in mixtures with 10 ng RRDP/ml or 0.01 ng LPS/ml. The endotoxin inhibitor, polymyxin B (10 μg/ml), strongly reduced the RRDP-induced formation of IL-1β at 1μg RRDP/ml (around 80 % inhibition), but had only marginal or no effects at higher RRDP-concentrations (10 and 100 μg /ml). In summary, all RRDP tested had a clear pyrogen effect in this in vitro model. Endotoxin on the particles but also other factors contributed to the pyrogenic effect. As opposed to the limulus amebocyte lysate (LAL) assay (which measures endotoxin alone), IPT measures a broad range of pyrogens that may be present on particulate matter. The IPT method thus affords a simple, sensitive and quantitative determination of the total pyrogenic potential of ambient particles.

  3. Mitochondrial respiration is sensitive to cytoarchitectural breakdown.

    PubMed

    Kandel, Judith; Angelin, Alessia A; Wallace, Douglas C; Eckmann, David M

    2016-11-07

    An abundance of research suggests that cellular mitochondrial and cytoskeletal disruption are related, but few studies have directly investigated causative connections between the two. We previously demonstrated that inhibiting microtubule and microfilament polymerization affects mitochondrial motility on the whole-cell level in fibroblasts. Since mitochondrial motility can be indicative of mitochondrial function, we now further characterize the effects of these cytoskeletal inhibitors on mitochondrial potential, morphology and respiration. We found that although they did not reduce mitochondrial inner membrane potential, cytoskeletal toxins induced significant decreases in basal mitochondrial respiration. In some cases, basal respiration was only affected after cells were pretreated with the calcium ionophore A23187 in order to stress mitochondrial function. In most cases, mitochondrial morphology remained unaffected, but extreme microfilament depolymerization or combined intermediate doses of microtubule and microfilament toxins resulted in decreased mitochondrial lengths. Interestingly, these two particular exposures did not affect mitochondrial respiration in cells not sensitized with A23187, indicating an interplay between mitochondrial morphology and respiration. In all cases, inducing maximal respiration diminished differences between control and experimental groups, suggesting that reduced basal respiration originates as a largely elective rather than pathological symptom of cytoskeletal impairment. However, viability experiments suggest that even this type of respiration decrease may be associated with cell death.

  4. Direct reading of electrocardiograms and respiration rates

    NASA Technical Reports Server (NTRS)

    Wise, J. P.

    1969-01-01

    Technique for reading heart and respiration rates is more accurate and direct than the previous method. Index of a plastic calibrated card is aligned with a point on the electrocardiogram. Complexes are counted as indicated on the card and heart or respiration rate is read directly from the appropriate scale.

  5. Photosynthesis and Respiration in a Jar.

    ERIC Educational Resources Information Center

    Buttner, Joseph K.

    2000-01-01

    Describes an activity that reduces the biosphere to a water-filled jar to simulate the relationship between cellular respiration, photosynthesis, and energy. Allows students in high school biology and related courses to explore quantitatively cellular respiration and photosynthesis in almost any laboratory setting. (ASK)

  6. Sleep and Respiration in Microgravity

    NASA Technical Reports Server (NTRS)

    West, John B.; Elliott, Ann R.; Prisk, G. Kim; Paiva, Manuel

    2003-01-01

    Sleep is often reported to be of poor quality in microgravity, and studies on the ground have shown a strong relationship between sleep-disordered breathing and sleep disruption. During the 16-day Neurolab mission, we studied the influence of possible changes in respiratory function on sleep by performing comprehensive sleep recordings on the payload crew on four nights during the mission. In addition, we measured the changes in the ventilatory response to low oxygen and high carbon dioxide in the same subjects during the day, hypothesizing that changes in ventilatory control might affect respiration during sleep. Microgravity caused a large reduction in the ventilatory response to reduced oxygen. This is likely the result of an increase in blood pressure at the peripheral chemoreceptors in the neck that occurs when the normally present hydrostatic pressure gradient between the heart and upper body is abolished. This reduction was similar to that seen when the subjects were placed acutely in the supine position in one-G. In sharp contrast to low oxygen, the ventilatory response to elevated carbon dioxide was unaltered by microgravity or the supine position. Because of the similarities of the findings in microgravity and the supine position, it is unlikely that changes in ventilatory control alter respiration during sleep in microgravity. During sleep on the ground, there were a small number of apneas (cessation of breathing) and hypopneas (reduced breathing) in these normal subjects. During sleep in microgravity, there was a reduction in the number of apneas and hypopneas per hour compared to preflight. Obstructive apneas virtually disappeared in microgravity, suggesting that the removal of gravity prevents the collapse of upper airways during sleep. Arousals from sleep were reduced in microgravity compared to preflight, and virtually all of this reduction was as a result of a reduction in the number of arousals from apneas and hypopneas. We conclude that any sleep

  7. Improving respiration measurements with gas exchange analyzers.

    PubMed

    Montero, R; Ribas-Carbó, M; Del Saz, N F; El Aou-Ouad, H; Berry, J A; Flexas, J; Bota, J

    2016-12-01

    Dark respiration measurements with open-flow gas exchange analyzers are often questioned for their low accuracy as their low values often reach the precision limit of the instrument. Respiration was measured in five species, two hypostomatous (Vitis Vinifera L. and Acanthus mollis) and three amphistomatous, one with similar amount of stomata in both sides (Eucalyptus citriodora) and two with different stomata density (Brassica oleracea and Vicia faba). CO2 differential (ΔCO2) increased two-fold with no change in apparent Rd, when the two leaves with higher stomatal density faced outside. These results showed a clear effect of the position of stomata on ΔCO2. Therefore, it can be concluded that leaf position is important to guarantee the improvement of respiration measurements increasing ΔCO2 without affecting the respiration results by leaf or mass units. This method will help to increase the accuracy of leaf respiration measurements using gas exchange analyzers.

  8. Ambient Air Quality Assessment with Particular Reference to Particulates in Jharia Coalfield, Eastern India.

    PubMed

    Singh, Gurdeep; Roy, Debananda; Sinha, Sweta

    2014-01-01

    Jharia Coalfield is the critically polluted area with the intense mining and associated industrial activities. There has been widespread concern of particulate pollution with the alarming levels of Suspended Particulate Matter (SPM) and Respirable Particulate Matter (PM10 & PM2.5). Coke oven plants, coal washing, thermal power stations and associated activities coupled with the transportation activities, give rise to critical air pollution levels in the region. This study envisages the assessment of air pollution of the region with particular reference to SPM, PM10 and PM2.5. Eighteen monitoring stations were selected considering various sources of pollution such as mining, industrial, commercial and residential areas apart from siting criteria as per IS: 5182 Part XIV. Air quality monitoring was carried out following standard methodologies and protocols as per Central Pollution Control Board (CPCB)/ National Ambient Air Quality Standard (NAAQS) norms using Respirable Dust Samplers (RDS) and Fine Particulate Samplers (PM2.5 Samplers). This study reveals considerable load of particulates (SPM, PM10, PM 2.5) which exceed not only the NAAQS but also the coal mining areas standards of Jharia coalfield, thus falling under the category of critically polluted area. Air Quality Indexing has also been developed which provides a clear map of the deterioration of air quality and also presenting comparative ranking of all the monitoring locations with respect to air quality status in the study area.

  9. The effect of gender and respirator brand on the association of respirator fit with facial dimensions.

    PubMed

    Oestenstad, R Kent; Elliott, Leshan J; Beasley, T Mark

    2007-12-01

    This study examined the association of facial dimensions with respirator fit considering the effect of gender and respirator brand. Forty-one subjects (20 white females and 21 white males) participated in the study. Each subject was measured for 12 facial dimensions using anthropometric sliding and spreading calipers and a steel measuring tape. Three quantitative fit tests were conducted with the same subject wearing one size of three different brands of half-mask respirators resulting in a total of nine fit tests. Linear mixed model analysis was used to model respirator fit as a function of gender and respirator brand while controlling for facial dimensions. Results indicated that the gender by respirator brand interaction was not statistically significant (p = 0.794), and there was no significant difference in respirator fit between males and females (p = 0.356). There was a significant difference in respirator fit among respirator brands (p < 0.001). Because correlations between facial dimensions and respirator fit differed across gender and respirator brand, six separate linear mixed models were fit to assess which facial dimensions most strongly relate to respirator fit using a "one variable at a step" backward elimination procedure. None of the 12 facial dimensions were significantly associated with respirator fit in all six models. However, bigonial breadth and menton-nasion length were significantly associated with respirator fit in five of the six models, and biectoorbitale breadth, bizygomatic breadth, and lip width were significantly associated with respirator fit in four of the six models. Although this study resulted in significant findings related to the correlation of respirator fit with menton-nasion length and lip width (the dimensions currently used to define the half-mask respirator test panel), other facial dimensions were also shown to be significantly associated with respirator fit. Based on these findings and findings from previous studies

  10. Depth-resolved particle-associated microbial respiration in the northeast Atlantic

    NASA Astrophysics Data System (ADS)

    Belcher, Anna; Iversen, Morten; Giering, Sarah; Riou, Virginie; Henson, Stephanie A.; Berline, Leo; Guilloux, Loic; Sanders, Richard

    2016-09-01

    Atmospheric levels of carbon dioxide are tightly linked to the depth at which sinking particulate organic carbon (POC) is remineralised in the ocean. Rapid attenuation of downward POC flux typically occurs in the upper mesopelagic (top few hundred metres of the water column), with much slower loss rates deeper in the ocean. Currently, we lack understanding of the processes that drive POC attenuation, resulting in large uncertainties in the mesopelagic carbon budget. Attempts to balance the POC supply to the mesopelagic with respiration by zooplankton and microbes rarely succeed. Where a balance has been found, depth-resolved estimates reveal large compensating imbalances in the upper and lower mesopelagic. In particular, it has been suggested that respiration by free-living microbes and zooplankton in the upper mesopelagic are too low to explain the observed flux attenuation of POC within this layer. We test the hypothesis that particle-associated microbes contribute significantly to community respiration in the mesopelagic, measuring particle-associated microbial respiration of POC in the northeast Atlantic through shipboard measurements on individual marine snow aggregates collected at depth (36-500 m). We find very low rates of both absolute and carbon-specific particle-associated microbial respiration (< 3 % d-1), suggesting that this term cannot solve imbalances in the upper mesopelagic POC budget. The relative importance of particle-associated microbial respiration increases with depth, accounting for up to 33 % of POC loss in the mid-mesopelagic (128-500 m). We suggest that POC attenuation in the upper mesopelagic (36-128 m) is driven by the transformation of large, fast-sinking particles to smaller, slow-sinking and suspended particles via processes such as zooplankton fragmentation and solubilisation, and that this shift to non-sinking POC may help to explain imbalances in the mesopelagic carbon budget.

  11. Effect of welding fume on heart rate variability among workers with respirators in a shipyard

    PubMed Central

    Han, Bor-Cheng; Liu, I-Jung; Chuang, Hsiao-Chi; Pan, Chih-Hong; Chuang, Kai-Jen

    2016-01-01

    Welding fume exposure is associated with heart rate variability (HRV) reduction. It is still unknown whether respirator can reduce effect of welding fume on HRV among welding workers in a shipyard. We recruited 68 welding workers with respirator and 52 welding workers without respirator to measure HRV indices, including standard deviation of normal-to-normal intervals (SDNN) and square root of the mean squared differences of successive intervals (r-MSSD) by ambulatory electrocardiographic (ECG). Personal exposure to particulate matter less than or equal to 2.5 μm in diameter (PM2.5) was measured by a dust monitor. The association between 5-minute mean PM2.5 and log10-transformed HRV indices was analyzed by mixed-effects models. We found 5-minute mean PM2.5 was associated with 8.9% and 10.3% decreases in SDNN and r-MSSD. Effect of PM2.5 on HRV indices was greatest among workers without respirator {SDNN: 12.4% (95% confidence interval = −18.8–−6.9); r-MSSD: 14.7% (95% confidence interval = −20.8–−8.6)}. Workers with respirator showed slight decreases in HRV indices {SDNN: 2.2% (95% confidence interval = −6.3–−1.9); r-MSSD: 4.0% (95% confidence interval = −6.4–−1.6)}. We conclude that respirator use reduces the effect of PM2.5 exposure on HRV among workers performing welding in a shipyard. PMID:27677526

  12. Nitrate respiration associated with detrital aggregates in aerobic bottom waters of the abyssal NE Pacific

    NASA Astrophysics Data System (ADS)

    Wolgast, D. M.; Carlucci, A. F.; Bauer, J. E.

    Rates of nitrate utilization in tube core respirometers (TCR) placed over aggregates on the seafloor at an abyssal site (Station M) in the eastern North Pacific Ocean increased at times of high particle flux. In the presence of aggregates, both oxygen and nitrate were used in respiration. The ratio of O 2 : NO 3 concentrations in ambient waters was 3.9, while O 2 : NO 3 utilization rates in TCR overlying and TCR aggregate pore waters were 2.6 and 0.6, respectively. We postulated that denitrification was occurring in microzones of the particle-rich oxygenated (135 μM) waters. To test this, nitrate respiration was measured aboard a ship in oxygen-minimum (˜26 μM) water supplemented with particulate matter collected by a surface net tow. Dissolved oxygen consumption occurred immediately, followed by nitrate utilization while oxygen was still present. Calculations from cell densities indicated 0.6 μM of the original 42 μM of nitrate was assimilated into bacterial biomass during 36 h of incubation, suggesting the major portion of the utilized nitrate was used in respiration. Nitrate utilization rates in the in situ incubation study and those of the shipboard experiment were 3.1 and 2.7 μM d -1, respectively. The results of the present studies suggest nitrate respiration occurs in microzones of aggregates in oxygenated bottom waters at times of high particle flux and causes some loss of fixed nitrogen.

  13. Clinical pulmonary function and industrial respirator wear

    SciTech Connect

    Raven, P.B.; Moss, R.F.; Page, K.; Garmon, R.; Skaggs, B.

    1981-12-01

    This investigation was the initial step in determining a clinical pulmonary test which could be used to evaluate workers as to their suitability to industrial respirator wear. Sixty subjects, 12 superior, 37 normal, and 11 moderately impaired with respect to lung function tests were evaluated with a battery of clinical pulmonary tests while wearing an industrial respirator. The respirator was a full-face mask (MSA-Ultravue) demand breathing type equipped with an inspiratory resistance of 85mm H/sub 2/O at 85 L/min air flow and an expiratory resistance of 25mm H/sub 2/O at 85 L/min air flow. Comparisons of these tests were made between the three groups of subjects both with and without a respirator. It appears that those lung tests which measure the flow characteristics of the lung especially those that are effort dependant are more susceptible to change as a result of respirator wear. Hence, the respirator affects the person with superior lung function to a greater degree than the moderately impaired person. It was suggested that the clinical test of 15 second maximum voluntary ventilations (MVV./sub 25/) may be the test of choice for determining worker capability in wearing an industrial respirator.

  14. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

    Aerosol threat detection requires the ability to discern between threat agents and ambient background particulate matter (PM) encountered in the environment. To date, Raman imaging technology has been demonstrated as an effective strategy for the assessment of threat agents in the presence of specific, complex backgrounds. Expanding our understanding of the composition of ambient particulate matter background will improve the overall performance of Raman Chemical Imaging (RCI) detection strategies for the autonomous detection of airborne chemical and biological hazards. Improving RCI detection performance is strategic due to its potential to become a widely exploited detection approach by several U.S. government agencies. To improve the understanding of the ambient PM background with subsequent improvement in Raman threat detection capability, ChemImage undertook the Airborne Particulate Threat Assessment (APTA) Project in 2005-2008 through a collaborative effort with the National Energy Technology Laboratory (NETL), under cooperative agreement number DE-FC26-05NT42594. During Phase 1 of the program, a novel PM classification based on molecular composition was developed based on a comprehensive review of the scientific literature. In addition, testing protocols were developed for ambient PM characterization. A signature database was developed based on a variety of microanalytical techniques, including scanning electron microscopy, FT-IR microspectroscopy, optical microscopy, fluorescence and Raman chemical imaging techniques. An automated particle integrated collector and detector (APICD) prototype was developed for automated collection, deposition and detection of biothreat agents in background PM. During Phase 2 of the program, ChemImage continued to refine the understanding of ambient background composition. Additionally, ChemImage enhanced the APICD to provide improved autonomy, sensitivity and specificity. Deliverables included a Final Report detailing our

  15. BOREAS TE-5 Soil Respiration Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Curd, Shelaine (Editor); Ehleriinger, Jim; Brooks, J. Renee; Flanagan, Larry

    2000-01-01

    The BOREAS TE-5 team collected measurements in the NSA and SSA on gas exchange, gas composition, and tree growth. Soil respiration data were collected from 26-May-94 to 07-Sep-94 in the BOREAS NSA and SSA to compare the soil respiration rates in different forest sites using a LI-COR 6200 soil respiration chamber (model 6299). The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distrobuted Activity Archive Center (DAAC).

  16. Respirable dust and silica exposure among World Trade Center cleanup workers.

    PubMed

    Pavilonis, Brian T; Mirer, Franklin E

    2017-03-01

    The cleanup effort following the destruction of the World Trade Center (WTC) was unprecedented and involved removal of 1.8 million tons of rubble over a nine-month period. Work at the site occurred 24 hr a day, 7 days a week and involved thousands of workers during the process. The Occupational Safety and Health Administration (OSHA) conducted personal and area exposure sampling during the cleanup of the site. Secondary data analysis was performed on OSHA air sampling data for respirable dust and silica from September 2001 to June 2002 at the WTC recovery site to characterize workers' exposure. Results for silica and respirable particulate were stratified by area and personal samples as well as job task for analysis. Of 1108 samples included in the analysis, 693 were personal and 415 were area. The mean result for personal silica samples was 42 μg/m(3) (Range: 4.2-1800 μg/m(3)). Workers identified as drillers had the highest mean silica exposure (72 μg/m(3); range: 5.8-800 μg/m(3)) followed by workers identified as dock builders (67 μg/m(3); range: 5.8-670 μg/m(3)). The mean result for personal samples for respirable particulate was 0.44 mg/m(3) (range: 0.00010-13 mg/m(3)). There were no discernable trends in personal respirable dust and silica concentrations with date.

  17. Respiration in Neonate Sea Turtles

    PubMed Central

    Paladino, Frank V.; Strohl, Kingman P.; Pilar Santidrián, T.; Klann, Kenneth; Spotila, James R.

    2007-01-01

    The pattern and control of respiration is virtually unknown in hatchling sea turtles. Using incubator-raised turtles, we measured oxygen consumption, frequency, tidal volume, and minute volume for leatherback (Dermochelys coriacea) and olive ridley (Lepidochelys olivacea) turtle hatchlings for the first six days after pipping. In addition, we tested the hatchlings’ response to hypercapnic, hyperoxic, and hypoxic challenges over this time period. Hatchling sea turtles generally showed resting ventilation characteristics that are similar to those of adults: a single breath followed by a long respiratory pause, slow frequency, and high metabolic rate. With hypercapnic challenge, both species responded primarily by elevating respiratory frequency via a decrease in the non-ventilatory period. Leatherback resting tidal volume increased with age but otherwise, neither species’ resting respiratory pattern nor response to gas challenge changed significantly over the first few days after hatching. At the time of nest emergence, sea turtles have achieved a respiratory pattern that is similar to that of actively diving adults. PMID:17258487

  18. Respiration in a changing environment.

    PubMed

    Perry, Steven F; Spinelli Oliveira, Elisabeth

    2010-08-31

    Multidisciplinary respiratory research highlighted in the present symposium uses existing and new models from all Kingdoms in both basic and applied research and bears upon molecular signaling processes that have been present from the beginning of life and have been maintained as an integral part of it. Many of these old mechanisms are still recognizable as ROS and oxygen-dependent pathways that probably were in place even before photosynthesis evolved. These processes are not only recognizable through relatively small molecules such as nucleotides and their derivatives. Also some DNA sequences such as the hypoxia response elements and pas gene family are ancient and have been co-opted in various functions. The products of pas genes, in addition to their function in regulating nuclear response to hypoxia as part of the hypoxia-inducible factor HIF, play key roles in development, phototransduction, and control of circadian rhythmicity. Also RuBisCO, an enzyme best known for incorporating CO(2) into organic substrates in plants also has an ancient oxygenase function, which plays a key role in regulating peroxide balance in cells. As life forms became more complex and aerobic metabolism became dominant in multicellular organisms, the signaling processes also took on new levels of complexity but many ancient elements remained. The way in which they are integrated into remodeling processes involved in tradeoffs between respiration and nutrition or in control of aging in complex organisms is an exciting field for future research.

  19. Light respiration by subtropical seaweeds.

    PubMed

    Carvalho, Matheus C; Eyre, Bradley D

    2017-03-20

    Here we report the first-ever measurements of light CO2 respiration rate (CRR) by seaweeds. We measured the influence of temperature (15 to 25°C) and light (irradiance from 60 to 670 μmol · m(-2) · s(-1) ) on the light CCR of two subtropical seaweed species, and measured the CRR of seven different seaweed species under the same light (150 μmol · m(-2) · s(-1) ) and temperature (25°C). There was little effect of irradiance on light CRR, but there was an effect of temperature. Across the seven species light CRR was similar to OCR (oxygen consumption rate in the dark), with the exception of a single species. The outlier species was a coralline alga, and the higher light CRR was probably driven by calcification. CRR could be estimated from OCR, as well as carbon photosynthetic rates from oxygen photosynthetic rates, which suggests that previous studies have probably provided good estimations of gross photosynthesis for seaweeds. This article is protected by copyright. All rights reserved.

  20. Respiration during sleep in kyphoscoliosis.

    PubMed Central

    Sawicka, E H; Branthwaite, M A

    1987-01-01

    Eleven subjects with non-paralytic and 10 with paralytic kyphoscoliosis and nine normal control subjects were studied during sleep. The Cobb angle of those with kyphoscoliosis varied from 60 degrees to 140 degrees (median 100 degrees) and the vital capacity varied from 17% to 56% (median 28%) of the value predicted on the basis of span. Recordings made during sleep included expired carbon dioxide tension at the nose, gas flow at the mouth, arterial oxygen saturation, chest wall movement, and the electroencephalogram, electro-oculogram, and electrocardiogram. In three subjects transcutaneous carbon dioxide tension was measured simultaneously. Patients with kyphoscoliosis hypoventilated during sleep, particularly in rapid eye movement sleep, resulting in a rise in end tidal and transcutaneous carbon dioxide tension, and a reduction in oxygen saturation to a degree not observed in normal subjects. Reduced chest wall movement was the major cause of these episodes, which were more frequent and occupied a greater proportion of sleep time in those with kyphoscoliosis than in normal subjects. Serious cardiac arrhythmias were rarely associated. It is concluded that disturbances of respiration during sleep occur in patients with kyphoscoliosis and that these may be important in the pathogenesis of cardiorespiratory failure. PMID:3424256

  1. Photosynthesis and Respiration in Leaf Slices.

    ERIC Educational Resources Information Center

    Brown, Simon

    1998-01-01

    Demonstrates how leaf slices provide an inexpensive material for illustrating several fundamental points about the biochemistry of photosynthesis and respiration. Presents experiments that illustrate the effects of photon flux density and herbicides and carbon dioxide concentration. (DDR)

  2. Apparatus for particulate matter analysis

    DOEpatents

    Gundel, Lara A.; Apte, Michael G.; Hansen, Anthony D.; Black, Douglas R.

    2007-01-30

    The apparatus described herein is a miniaturized system for particle exposure assessment (MSPEA) for the quantitative measurement and qualitative identification of particulate content in gases. The present invention utilizes a quartz crystal microbalance (QCM) or other mass-sensitive temperature compensated acoustic wave resonator for mass measurement. Detectors and probes and light sources are used in combination for the qualitative determination of particulate matter.

  3. Organohalide respiration: microbes breathing chlorinated molecules

    PubMed Central

    Leys, David; Adrian, Lorenz; Smidt, Hauke

    2013-01-01

    Bacterial respiration has taken advantage of almost every redox couple present in the environment. The reduction of organohalide compounds to release the reduced halide ion drives energy production in organohalide respiring bacteria. This process is centred around the reductive dehalogenases, an iron–sulfur and corrinoid containing family of enzymes. These enzymes, transcriptional regulators and the bacteria themselves have potential to contribute to future bioremediation solutions that address the pollution of the environment by halogenated organic compounds. PMID:23479746

  4. Telephone communications with several commercial respirators.

    PubMed

    Johnson, A T; Scott, W H; Coyne, K M; Koh, F C; Rebar, J E

    2001-01-01

    Previous work showed that telephone communications while wearing military respirators degraded both word comprehension and recognition speed. In addition, electronic amplification of the speech diaphragm signal had shown no advantage to the extra hardware. This experiment was performed to test effects of different configurations of commercially available respirators on telephone communications accuracy and speed. Twelve pairs of subjects were separated into different rooms and communicated by telephone. Modified rhyme-test words were presented by computer to the speaker, who transmitted the word by telephone to the listener. During the first replication, subjects were given no instruction about telephone communications procedure. During the second replication subjects followed a communications protocol that instructed them when to move the telephone handset from their ears to their mouths. Results showed that the protocol uniformly improved communications accuracy without incurring any extra time penalty. Word comprehension was still twice as fast without a respirator as with a respirator. Accuracy with the protocol nearly equaled the no respirator control value for most respirators tested.

  5. Mitochondrial respiration without ubiquinone biosynthesis

    PubMed Central

    Wang, Ying; Hekimi, Siegfried

    2013-01-01

    Ubiquinone (UQ), a.k.a. coenzyme Q, is a redox-active lipid that participates in several cellular processes, in particular mitochondrial electron transport. Primary UQ deficiency is a rare but severely debilitating condition. Mclk1 (a.k.a. Coq7) encodes a conserved mitochondrial enzyme that is necessary for UQ biosynthesis. We engineered conditional Mclk1 knockout models to study pathogenic effects of UQ deficiency and to assess potential therapeutic agents for the treatment of UQ deficiencies. We found that Mclk1 knockout cells are viable in the total absence of UQ. The UQ biosynthetic precursor DMQ9 accumulates in these cells and can sustain mitochondrial respiration, albeit inefficiently. We demonstrated that efficient rescue of the respiratory deficiency in UQ-deficient cells by UQ analogues is side chain length dependent, and that classical UQ analogues with alkyl side chains such as idebenone and decylUQ are inefficient in comparison with analogues with isoprenoid side chains. Furthermore, Vitamin K2, which has an isoprenoid side chain, and has been proposed to be a mitochondrial electron carrier, had no efficacy on UQ-deficient mouse cells. In our model with liver-specific loss of Mclk1, a large depletion of UQ in hepatocytes caused only a mild impairment of respiratory chain function and no gross abnormalities. In conjunction with previous findings, this surprisingly small effect of UQ depletion indicates a nonlinear dependence of mitochondrial respiratory capacity on UQ content. With this model, we also showed that diet-derived UQ10 is able to functionally rescue the electron transport deficit due to severe endogenous UQ deficiency in the liver, an organ capable of absorbing exogenous UQ. PMID:23847050

  6. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  7. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  8. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  9. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  10. 42 CFR 84.250 - Vinyl chloride respirators; description.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Vinyl chloride respirators; description. 84.250... Respirators § 84.250 Vinyl chloride respirators; description. Vinyl chloride respirators, including all... escape from vinyl chloride atmospheres containing adequate oxygen to support life, are...

  11. 42 CFR 84.197 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.197... Cartridge Respirators § 84.197 Respirator containers; minimum requirements. Respirators shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type...

  12. 42 CFR 84.134 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84.134... Respirators § 84.134 Respirator containers; minimum requirements. Supplied-air respirators shall be equipped with a substantial, durable container bearing markings which show the applicant's name, the type...

  13. 42 CFR 84.191 - Chemical cartridge respirators; required components.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the...

  14. 42 CFR 84.191 - Chemical cartridge respirators; required components.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the...

  15. 42 CFR 84.191 - Chemical cartridge respirators; required components.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the...

  16. 42 CFR 84.191 - Chemical cartridge respirators; required components.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the...

  17. 42 CFR 84.191 - Chemical cartridge respirators; required components.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Chemical cartridge respirators; required components... Chemical Cartridge Respirators § 84.191 Chemical cartridge respirators; required components. (a) Each chemical cartridge respirator described in § 84.190 shall, where its design requires, contain the...

  18. Particulate erosion mechanisms

    NASA Technical Reports Server (NTRS)

    Veerabhadrarao, P.; Buckley, D. H.

    1983-01-01

    Particulate damage and erosion of ductile metals are today plaguing design and field engineers in diverse fields of engineering and technology. It was found that too many models and theories were proposed leading to much speculation from debris analysis and failure mechanism postulations. Most theories of solid particle erosion are based on material removal models which do not fully represent the actual physical processes of material removal. The various mechanisms proposed thus far are: melting, low-cycle fatigue, extrusion, delamination, shear localization, adhesive material transfer, etc. The experimental data on different materials highlighting the observed failure modes of the deformation and cutting wear processes using optical and scanning electron microscopy are presented. The most important mechanisms proved from the experimental observations of the specimens exposed to both spherical and angular particles are addressed, and the validity of the earlier theories discussed. Both the initial stages of damage and advanced stages of erosion were studied to gain a fundamental understanding of the process.

  19. Pressure driven particulate flows

    SciTech Connect

    Ingher, M.S.; Mondy, L.A.

    1996-03-01

    Numerical simulations of pressure-driven particulate Stokes flows are performed in cylindrical and rectangular conduits using a parallel boundary element code. Spherical particles are randomly placed in the conduits and a pressure drop between the ends of the conduits is imposed by the boundary conditions to induce a Poiseuille-like flow field. The instantaneous velocities of the particles are then calculated, as well as the additional pressure drop necessary to maintain a constant flow rate. Because the results depend on the spatial distribution of the particles, several random configurations of particles are examined for each case. Depending on two different interpretations of the numerical results, the solid phase can be represented as either leading or lagging the fluid phase. Both of the analyses and interpretations are presented.

  20. Cell-mediated immunity to soluble and particulate inhaled antigens

    PubMed Central

    Hill, J. O.; Burrell, R.

    1979-01-01

    In order to determine the influence of an antigen's physical properties on the development of cell-mediated immunity (CMI) in the lung following aerosol immunization, human serum albumin (HSA) was prepared in either a soluble or a particulate form, the latter being coupled to respirable, carboxylated latex beads. Antigen was administered via an aerosol to groups of guinea-pigs, twice weekly for up to 4 weeks. Additional groups of animals served as unexposed and unconjugated latex controls. Lymphoid cells for CMI assays were isolated from the lung by bronchopulmonary lavage and from blood for use in mitogen- and antigen-induced lymphocyte transformation assays, as well as indirect macrophage migration inhibition tests. Particulate HSA-exposed animals yielded the highest numbers of free lung cells containing predominantly macrophages, with up to 33% lymphocytes. These were followed by the latex control, soluble HSA and unexposed control groups, respectively. Only the animals exposed to particulate HSA had evidence of antigen reactivation in the lung cell populations as measured by lymphocyte stimulation assays. In contrast, a response to polyclonal mitogens was found only in animals exposed to antigen in a soluble form. Data from macrophage depletion experiments suggest that the antigenicity of inhaled antigens may be due to the types and numbers of cells responding to the stimulus, and the subsequent role the alveolar macrophage may play in the modulation of cellular immunity. PMID:393444

  1. High Diversity of Fungi in Air Particulate Matter

    NASA Astrophysics Data System (ADS)

    Fröhlich-Nowoisky, J.; Despres, V. R.; Pöschl, U.

    2009-04-01

    Fungal spores account for large proportions of air particulate matter, and they influence the hydrological cycle and climate as nuclei for water droplets and ice crystals in clouds, fog and precipitation. Moreover, some fungi are major pathogens and allergens. The diversity of airborne fungi is, however, hardly known. By DNA analysis we found pronounced differences in the relative abundance and seasonal cycles of various groups of fungi in coarse and fine particulate matter, with more plant pathogens in the coarse and more human pathogens and allergens in the respirable fine particle fraction (< 3 µm). Moreover, the ratio of Basidiomycota to Ascomycota was found to be much higher than previously assumed, which might also apply to the biosphere. References: Després, V.R., J.F. Nowoisky, M. Klose, R. Conrad, M.O. Andreae, U. Pöschl, Characterization of primary biogenic aerosol particles in urban, rural, and high-alpine air by DNA sequence and restriction fragment analysis of ribosomal RNA genes, Biogeosciences, 4, 1127-1141, 2007. Elbert, W., P. E. Taylor, M. O. Andreae, U. Pöschl, Contribution of fungi to primary biogenic aerosols in the atmosphere: wet and dry discharged spores, carbohydrates, and inorganic ions, Atmospheric Chemistry and Physics, 7, 4569-4588, 2007. Fröhlich-Nowoisky, J. Despres, V.R., Pöschl, U.: High diversity of fungi in air particulate matter, Proceedings of the National Academy of Sciences, submitted, 2008.

  2. A comparison of facemask and respirator filtration test methods.

    PubMed

    Rengasamy, Samy; Shaffer, Ronald; Williams, Brandon; Smit, Sarah

    2017-02-01

    NIOSH published a Federal Register Notice to explore the possibility of incorporating FDA required filtration tests for surgical masks (SMs) in the 42 CFR Part 84 respirator certification process. There have been no published studies comparing the filtration efficiency test methods used for NIOSH certification of N95 filtering facepiece respirators (N95 FFRs) with those used by the FDA for clearance of SMs. To address this issue, filtration efficiencies of "N95 FFRs" including six N95 FFR models and three surgical N95 FFR models, and three SM models were measured using the NIOSH NaCl aerosol test method, and FDA required particulate filtration efficiency (PFE) and bacterial filtration efficiency (BFE) methods, and viral filtration efficiency (VFE) method. Five samples of each model were tested using each method. Both PFE and BFE tests were done using unneutralized particles as per FDA guidance document. PFE was measured using 0.1 µm size polystyrene latex particles and BFE with ∼3.0 µm size particles containing Staphylococcus aureus bacteria. VFE was obtained using ∼3.0 µm size particles containing phiX 174 as the challenge virus and Escherichia coli as the host. Results showed that the efficiencies measured by the NIOSH NaCl method for "N95 FFRs" were from 98.15-99.68% compared to 99.74-99.99% for PFE, 99.62-99.9% for BFE, and 99.8-99.9% for VFE methods. Efficiencies by the NIOSH NaCl method were significantly (p = <0.05) lower than the other methods. SMs showed lower efficiencies (54.72-88.40%) than "N95 FFRs" measured by the NIOSH NaCl method, while PFE, BFE, and VFE methods produced no significant difference. The above results show that the NIOSH NaCl method is relatively conservative and is able to identify poorly performing filtration devices. The higher efficiencies obtained using PFE, BFE and VFE methods show that adding these supplemental particle penetration methods will not improve respirator certification.

  3. Dynamics of the Particulate Organic Carbon in the southern Baltic Sea.

    NASA Astrophysics Data System (ADS)

    Dzierzbicka-Glowacka, L.; Maciejewska, A.; Kuliński, K.; Pempkowiak, J.

    2009-04-01

    This paper presents a one-dimensional Particulate Organic Carbon Dynamic Model 1D-POCD. The particulate organic carbon concentration is determined as the sum of phytoplankton, zooplankton and dead organic matter (detritus) concentrations. Mathematically, the pelagic variables of 1D-POCD model are described by a second-order partial differential equation of the diffusion type with biogeochemical sources and sinks. The temporal changes in the phytoplankton biomass are caused by primary production, respiration, mortality, grazing by zooplankton and sinking. The zooplankton biomass is affected by ingestion, excretion, respiration, fecal production, mortality, and carnivorous grazing. The changes in the pelagic detritus concentration are determined by input of: dead phytoplankton and zooplankton, natural mortality of predators, fecal pellets, and sinks: sedimentation, zooplankton grazing and decomposition. The 1D-POCD model was used to simulate the seasonal dynamics of particulate organic carbon fluxes in the southern Baltic Sea (Gdańsk Deep, Bornholm Deep and Gotland Deep). The results of the simulations were compared with the mean concentrations of particulate organic carbon recorded in situ at station situated at the Gdańsk Deep. Generally good agreement between the measured and modeled POC concentration was obtained.

  4. Magnetic characterization of airborne particulates

    NASA Astrophysics Data System (ADS)

    Kim, W.; Doh, S.; Yu, Y.

    2010-12-01

    Burning fossil fuels from vehicles, domestics, industries and power plants in the large urban or industrial areas emit significant quantity of anthropogenic particulates which become a potential threat to human health. Here, we present temporal variability of particulate pollution associated with compositional differences, using magnetic measurements and electron microscopic observations. Six different grain-sizes of airborne particulates have been collected by filtering from 10 precipitation events in Seoul, Korea from February 2009 to June 2009. Magnetic concentration proxies show relatively better (R2 >0.6) and poorer correlations (R2 <0.3) with the masses of samples filtered by >0.45 μm and <0.45 μm sizes, respectively, suggesting the usefulness of magnetic characterization for the >0.45 μm particulates. Temporally, magnetic concentrations are higher in the cold season than the warm season. In particular, a significant increase of magnetic concentration is observed in 3 μm and 1 μm filters after the Chinese wind-blown dust events, indicating additional influx of fine-grained anthropogenic particulates into Seoul. Microscopic observations identify that increase of magnetic concentration is highly linked with the frequent occurrence of combustion derived particulates (i.e., carbon and/or sulfur mixed particles) than natural alumino-silicates. Overall, the present study demonstrates that magnetic measurements efficiently reflect the concentration of particulates produced from fossil-fuel combustion among the airborne particles from various sources.

  5. Characterization of Carbon Particulates in the Exit Flow of a Plasma Pyrolysis Assembly (PPA) Reactor

    NASA Technical Reports Server (NTRS)

    Green, Robert D.; Meyer, Marit E.; Agui, Juan H.; Berger, Gordon M.; Vijayakumar, R.; Abney, Morgan B.; Greenwood, Zachary

    2015-01-01

    The ISS presently recovers oxygen from crew respiration via a Carbon Dioxide Reduction Assembly (CRA) that utilizes the Sabatier chemical process to reduce captured carbon dioxide to methane (CH4) and water. In order to recover more of the hydrogen from the methane and increase oxygen recovery, NASA Marshall Space Flight Center (MSFC) is investigating a technology, plasma pyrolysis, to convert the methane to acetylene. The Plasma Pyrolysis Assembly (or PPA), achieves 90% or greater conversion efficiency, but a small amount of solid carbon particulates are generated as a side product and must be filtered before the acetylene is removed and the hydrogen-rich gas stream is recycled back to the CRA. In this work, we present the experimental results of an initial characterization of the carbon particulates in the PPA exit gas stream. We also present several potential options to remove these carbon particulates via carbon traps and filters to minimize resupply mass and required downtime for regeneration.

  6. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be

  7. Sampling of respirable isocyanate particles.

    PubMed

    Gylestam, Daniel; Gustavsson, Marcus; Karlsson, Daniel; Dalene, Marianne; Skarping, Gunnar

    2014-04-01

    An advanced design of a denuder impactor (DI) sampler has been developed for characterization of possible airborne isocyanate exposure in different particle size fractions. The sampler is equipped with 12 different parallel denuder tubes, 4 impaction stages with the cut-off values (d50) of: 9.5, 4, 2.5 and 1 µm, and an end filter that collects particles < 1 µm. All collecting parts were impregnated with di-n-butylamine DBA as the reagent in a mixture with acetic acid. The performance of the DI sampler was studied on a standard atmosphere containing gas and particulate isocyanates. The isocyanate atmosphere was generated by liquid permeation of 2,4-, 2,6-Toluene Diisocyanate (TDI), 1,6-Hexamethylene Diisocyanate (HDI) and Isophorone Diisocyanate (IPDI). 4,4'-Methylene Diphenyl Diisocyanate (MDI) particles were generated by heating of technical MDI and condensing the mixture of gas and particle-borne MDI in an atmosphere containing mixed salt particles. The study was performed in a 0.85 m3 environmental chamber with stainless steel walls. With the advancement of the DI sampler it is now possible to collect isocyanate particle samples for up to 320 min. The performance of the DI sampler is essentially unaffected by the humidity. The DI sampler and the ASSET EZ4-NCO sampler (Sigma-Aldrich/Supelco, Bellefonte, PA, USA) gave similar results. Sample losses within the DI sampler are low. In the environmental chamber it was observed that the particle distribution may be affected by the humidity and ageing. A scanning mobility particle sizer (SMPS) was used to separate a flow of selected fractions containing MDI particles from mixed MDI and salt particles. The particle-size distribution had a maximum at about 300 nm, but later in the environmental chamber 1 µm dominated. The distribution was very different as compared to with only NaCl or MDI present. The biological relevance for studying isocyanate nano particles is significant as these have the possibility to reach the

  8. Respiration and Reproductive Effort in Xanthium canadense

    PubMed Central

    KINUGASA, TOSHIHIKO; HIKOSAKA, KOUKI; HIROSE, TADAKI

    2005-01-01

    • Background and Aims The proportion of resources devoted to reproduction in the plant is called the reproductive effort (RE), which is most commonly expressed as the proportion of reproductive biomass to total plant biomass production (REW). Reproductive yield is the outcome of photosynthates allocated to reproductive structures minus subsequent respiratory consumption for construction and maintenance of reproductive structures. Thus, REW can differ from RE in terms of photosynthates allocated to reproductive structures (REP). • Methods Dry mass growth and respiration of vegetative and reproductive organs were measured in Xanthium canadense and the amount of photosynthates and its partitioning to dry mass growth and respiratory consumption were determined. Differences between REW and REP were analysed in terms of growth and maintenance respiration. • Key Results The fraction of allocated photosynthates that was consumed by respiration was smaller in the reproductive organ than in the vegetative organs. Consequently, REP was smaller than REW. The smaller respiratory consumption in the reproductive organ resulted from its shorter period of existence and a seasonal decline in temperature, as well as a slower rate of maintenance respiration, although the fraction of photosynthates consumed by growth respiration was larger than in the vegetative organs. • Conclusions Reproductive effort in terms of photosynthates (REP) was smaller than that in terms of biomass (REW). This difference resulted from respiratory consumption for maintenance, which was far smaller in the reproductive organ than in vegetative organs. PMID:15837721

  9. Respirator Filter Efficiency Testing Against Particulate and Biological Aerosols Under Moderate to High Flow Rates

    DTIC Science & Technology

    2006-08-01

    stopped and the filter removed from the system for analysis. Polonium - 210 static eliminators were used to minimize particle loss during transport to...may provide a considerable overestimate of filter performance. Brosseau et al. (1990) compared the collection of silica and asbestos aerosols by DM...a half times as great as that measured under steady flow conditions, which is consistent with the results of Stafford et al. (1973). The asbestos

  10. 42 CFR 84.1157 - Chemical cartridge respirators with particulate filters; performance requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered...

  11. 42 CFR 84.1157 - Chemical cartridge respirators with particulate filters; performance requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered...

  12. 42 CFR 84.1157 - Chemical cartridge respirators with particulate filters; performance requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered...

  13. Development of emission factors for particulate matter in a school

    SciTech Connect

    Scheff, P.A.; Paulius, V.; Conroy, L.M.

    1999-07-01

    Schools have complex indoor environments which are influenced by many factors such as number of occupants, building design, office equipment, cleaning agents, and school activities. Like large office buildings, school environments may be adversely influenced by deficiencies in ventilation which may be due to improper operation of HVAC systems, attempts at energy efficiency that limit the supply of outdoor air, or remodeling of building components. Most importantly, children spend up to a third of their time in these structures, and thus it is desirable to better understand the environmental quality in these buildings. A middle school (grades 6 to 8) in a residential section of Springfield, IL was selected for this baseline indoor air quality survey. The school was characterized as having no health complaints, good maintenance schedules, and did not contain carpeting within the classrooms or hallways. The focus of this paper is on the measurements of air quality in the school. The development of emission factors for particulate matter is also discussed. Four indoor locations including the Cafeteria, a Science Classroom, an Art Classroom, and the Lobby outside of the main office, and one outdoor location were sampled for various environmental comfort and pollutant parameters for one week in February of 1997. Integrated samples (8 hour sampling time) for respirable and total particulate matter, and short-term measurements of bioaerosols (two minute samples, three times per day) on three consecutive days were collected at each of the indoor and outdoor sites. Continuous measurements of carbon dioxide, carbon monoxide, temperature and humidity were logged at all locations for five days. Continuous measurements of respirable particulate matter were also collected in the Lobby area. Detailed logs of occupant activity were also collected at each indoor monitoring location throughout the study. Total particle concentrations ranged from 29 to 177 {micro}g/m{sup 3} in the art

  14. Electrically heated particulate filter restart strategy

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-07-12

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a propagation module that estimates a propagation status of combustion of particulate matter in the particulate filter. A regeneration module controls current to the particulate filter to re-initiate regeneration based on the propagation status.

  15. Measurement of vehicle particulate emissions.

    PubMed Central

    Beltzer, M

    1975-01-01

    A constant volume sampler (CVS) compatible auto exhaust particulate sampling system has been built which samples exhaust isokinetically at constant temperature. This system yields internally consistent results and is capable of frequent and convenient operation. PMID:50931

  16. Soil respiration partition and its components in the total agro-ecosystem respiration

    NASA Astrophysics Data System (ADS)

    Delogu, Emilie; LeDantec, Valerie; Mordelet, Patrick; Buysse, Pauline; Aubinet, Marc; Pattey, Elizabeth; Mary, Bruno

    2013-04-01

    Close to 15% of the Earth's terrestrial surface is used for cropland. In the context of global warming, and acknowledged by the Kyoto Protocol, agricultural soils could be a significant sink for atmospheric CO2. Understanding the factors influencing carbon fluxes of agricultural soils is essential for implementing efficient mitigation practices. Most of the soil respiration modeling studies was carried out in forest ecosystems, but only a few was carried out in agricultural ecosystems. In the study, we evaluated simple formalisms to model soil respiration using wheat data from four contrasting geographical mi-latitude regions. Soil respiration were measured in three winter wheat fields at Lamasquère (43°49'N, 01°23'E, 2007) and Auradé (43°54'N, 01°10'E, 2008), South-West France and Lonzée (50°33'N, 4°44'E, 2007), Belgium, and in a spring wheat field at Ottawa (45°22'N, 75°43'W, 2007, 2011), Ontario, Canada. Manual closed chambers were used in the French sites. The Belgium and Canadian sites were equipped with automated closed chamber systems, which continuously collected 30-min soil respiration exchanges. All the sites were also equipped with eddy flux towers. When eddy flux data were collected over bare soil, the net ecosystem exchange (NEE) was equal to soil respiration exchange. These NEE data were used to validate the model. Different biotic and abiotic descriptors were used to model daily soil respiration and its heterotrophic and autotrophic components: soil temperature, soil relative humidity, Gross Primary Productivity (GPP), shoot biomass, crop height, with different formalisms. It was interesting to conclude that using biotic descriptors did not improve the performances of the model. In fact, a combination of abiotic descriptors (soil humidity and soil temperature) allowed significant model formalism to model soil respiration. The simple soil respiration model was used to calculate the heterotrophic and autotrophic source contributions to

  17. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    NASA Astrophysics Data System (ADS)

    Kiko, Rainer; Hauss, Helena; Buchholz, Friedrich; Melzner, Frank

    2016-04-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2, and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply could fuel bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean considerably. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a down-regulation of ammonium excretion. We exposed calanoid copepods from the Eastern Tropical North Atlantic (ETNA; Undinula vulgaris and Pleuromamma abdominalis) and euphausiids from the Eastern Tropical South Pacific (ETSP; Euphausia mucronata) and the ETNA (Euphausia gibboides) to different temperatures, carbon dioxide and oxygen levels to study their survival, respiration and excretion rates at these conditions. An increase in temperature by 10 °C led to an approximately 2-fold increase of the respiration and excretion rates of U. vulgaris (Q10, respiration = 1.4; Q10, NH4-excretion = 1.6), P. abdominalis (Q10, respiration = 2.0; Q10, NH4-excretion = 2.4) and

  18. BOREAS TE-2 Wood Respiration Data

    NASA Technical Reports Server (NTRS)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of wood respiration conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  19. BOREAS TE-2 Continuous Wood Respiration Data

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Papagno, Andrea (Editor); Ryan, Michael G.; Lavigne, Michael

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of wood respiration measured continuously (about once per hour) in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  20. BOREAS TE-2 Foliage Respiration Data

    NASA Technical Reports Server (NTRS)

    Ryan, Michael G.; Hall, Forrest G. (Editor); Lavigne, Michael; Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set contains measurements of foliar respiration conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  1. BOREAS TE-2 Root Respiration Data

    NASA Technical Reports Server (NTRS)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set includes means of tree root respiration measurements on roots having diameters ranging from 0 to 2 mm conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  2. Electrical diesel particulate filter (DPF) regeneration

    DOEpatents

    Gonze, Eugene V; Ament, Frank

    2013-12-31

    An exhaust system that processes exhaust generated by an engine includes a diesel particulate filter (DPF) that is disposed downstream of the engine and that filters particulates from the exhaust. An electrical heater is disposed upstream of the DPF and selectively heats the exhaust to initiate combustion of the particulates within the exhaust as it passes therethrough. Heat generated by combustion of the particulates induces combustion of particulates within the DPF.

  3. Changes in soil respiration components and their specific respiration along three successional forests in the subtropics

    DOE PAGES

    Han, Tianfeng; Liu, Juxiu; Wang, Gangsheng; ...

    2016-01-16

    1.Understanding how soil respiration components change with forest succession is critical for modelling and predicting soil carbon (C) processes and its sequestration below-ground. The specific respiration (a ratio of respiration to biomass) is increasingly being used as an indicator of forest succession conceptually based on Odum's theory of ecosystem development. However, the hypothesis that specific soil respiration declines with forest succession remains largely untested. 2.We used a trenching method to partition soil respiration into heterotrophic respiration and autotrophic respiration (RH and RA) and then evaluated the specific RH and specific RA in three successional forests in subtropical China. 3.Our resultsmore » showed a clear seasonality in the influence of forest succession on RH, with no significant differences among the three forests in the dry season but a higher value in the old-growth forest than the other two forests in the wet season. RA in the old-growth forest tended to be the highest among the three forests. Both the specific RH and specific RA decreased with the progressive maturity of three forests. 4.Lastly, our results highlight the importance of forest succession in determining the variation of RH in different seasons. With forest succession, soil microbes and plant roots become more efficient to conserve C resources, which would result in a greater proportion of C retained in soils.« less

  4. Respiration patterns of resting wasps (Vespula sp.).

    PubMed

    Käfer, Helmut; Kovac, Helmut; Stabentheiner, Anton

    2013-04-01

    We investigated the respiration patterns of wasps (Vespula sp.) in their viable temperature range (2.9-42.4°C) by measuring CO2 production and locomotor and endothermic activity. Wasps showed cycles of an interburst-burst type at low ambient temperatures (Ta<5°C) or typical discontinuous gas exchange patterns with closed, flutter and open phases. At high Ta of >31°C, CO2 emission became cyclic. With rising Ta they enhanced CO2-emission primarily by an exponential increase in respiration frequency, from 2.6 mHz at 4.7°C to 74 mHz at 39.7°C. In the same range of Ta CO2 release per cycle decreased from 38.9 to 26.4 μl g(-1)cycle(-1). A comparison of wasps with other insects showed that they are among the insects with a low respiratory frequency at a given resting metabolic rate (RMR), and a relatively flat increase of respiratory frequency with RMR. CO2 emission was always accompanied by abdominal respiration movements in all open phases and in 71.4% of the flutter phases, often accompanied by body movements. Results suggest that resting wasps gain their highly efficient gas exchange to a considerable extent via the length and type of respiration movements.

  5. 78 FR 18535 - Respirator Certification Fees

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-27

    ... HUMAN SERVICES 42 CFR Part 84 RIN 0920-AA42 Respirator Certification Fees AGENCY: Centers for Disease... and Human Services (HHS) proposes to revise the fee structure currently used by the National Institute... number). SUPPLEMENTARY INFORMATION: This proposed rule is designed to establish fees for the...

  6. Development of conformal respirator monitoring technology

    SciTech Connect

    Shonka, J.J.; Weismann, J.J.; Logan, R.J.

    1997-04-01

    This report summarizes the results of a Small Business Innovative Research Phase II project to develop a modular, surface conforming respirator monitor to improve upon the manual survey techniques presently used by the nuclear industry. Research was performed with plastic scintillator and gas proportional modules in an effort to find the most conducive geometry for a surface conformal, position sensitive monitor. The respirator monitor prototype developed is a computer controlled, position-sensitive detection system employing 56 modular proportional counters mounted in molds conforming to the inner and outer surfaces of a commonly used respirator (Scott Model 801450-40). The molds are housed in separate enclosures and hinged to create a {open_quotes}waffle-iron{close_quotes} effect so that the closed monitor will simultaneously survey both surfaces of the respirator. The proportional counter prototype was also designed to incorporate Shonka Research Associates previously developed charge-division electronics. This research provided valuable experience into pixellated position sensitive detection systems. The technology developed can be adapted to other monitoring applications where there is a need for deployment of many traditional radiation detectors.

  7. Electrophrenic respiration in patients with high quadriplegia.

    PubMed

    Sharkey, P C; Halter, J A; Nakajima, K

    1989-04-01

    After determining that 15 patients with high spinal cord injuries who were permanently apneic had viable phrenic nerves, electrophrenic respiration units were implanted. Thirteen of the patients (86%) achieved full-time respiration and two more achieved half-time respiration. Despite the loss of 8 patients to unrelated problems, 7 now use electrophrenic respiration continuously, one having done so for 16 years. The patient selection criteria, neurophysiological evaluation method, surgical procedure, postoperative care, and methods for diagnosis of system failures are presented. A comparison of the cervical and thoracic procedures is made. The cervical approach is preferred. Complications consisted primarily of equipment failures. For the external components there were several cases of antenna connection and battery connection failures. The implanted receivers failed in 6 cases with an average lifetime of 48 months, ranging from 24 to 108 months. In one case fibrosis around the electrode resulted in failure to stimulate the phrenic nerve effectively. In another case, infection required removal of the system which was reimplanted later and has continued to provide successful ventilation.

  8. Effects of cadmium on heart mitochondrial respiration

    SciTech Connect

    Kisling, G.M.; Kopp, S.J.; Paulson, D.J.; Tow, J.P.

    1986-03-01

    The purpose of this study was to determine the direct effect of cadmium on isolated heart mitochondrial respiration. Mitochondria were rapidly prepared by polytroning hearts from male Sprague-Dawley rats in a 0.25 M Sucrose, 4 mM Tris, 1 mM EGTA, 0.2% BSA buffer (pH 7.4), followed by a two-part differential centrifugation. Mitochondria were resuspended in this same Tris-sucrose-BSA buffer minus EGTA and mitochondrial respiration was assayed using a Clark oxygen electrode system at a concentration of 0.5 mg total mitochondrial protein/ml assay buffer. At 5 x 10/sup -6/ M cadmium, mitochondrial state 3 respiration (pyruvate plus malate) was reduced to a level 74.8% of the control value. A 50% reduction in state 3 respiratory rate was achieved at a cadmium concentration of 8.75 x 10/sup -6/ M. The respiratory control ratio did not change significantly but at higher cadmium concentrations (< greater than or equal to 1.25 x 10/sup -5/ M) the ADP/O ratio was increased. None of the cadmium concentrations tested, from 10/sup -8/ to 10/sup -4/ M, demonstrated an uncoupling response. These data suggest that cadmium acts strictly as an inhibitor of heart mitochondrial oxidative phosphorylation. These results contrast those of earlier work involving liver mitochondria in which cadmium was reported to uncouple mitochondrial respiration.

  9. Estimating Canopy Dark Respiration for Crop Models

    NASA Technical Reports Server (NTRS)

    Monje Mejia, Oscar Alberto

    2014-01-01

    Crop production is obtained from accurate estimates of daily carbon gain.Canopy gross photosynthesis (Pgross) can be estimated from biochemical models of photosynthesis using sun and shaded leaf portions and the amount of intercepted photosyntheticallyactive radiation (PAR).In turn, canopy daily net carbon gain can be estimated from canopy daily gross photosynthesis when canopy dark respiration (Rd) is known.

  10. Hydrocarbon-enhanced particulate filter regeneration via microwave ignition

    DOEpatents

    Gonze, Eugene V.; Brown, David B.

    2010-02-02

    A regeneration method for a particulate filter includes estimating a quantity of particulate matter trapped within the particulate filter, comparing the quantity of particulate matter to a predetermined quantity, heating at least a portion of the particulate filter to a combustion temperature of the particulate matter, and introducing hydrocarbon fuel to the particulate filter. The hydrocarbon fuel facilitates combustion of the particulate matter to regenerate the particulate filter.

  11. 40 CFR 721.10119 - Siloxane modified silica nanoparticles (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  12. 40 CFR 721.10119 - Siloxane modified silica nanoparticles (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  13. 40 CFR 721.10120 - Siloxane modified alumina nanoparticles (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  14. 40 CFR 721.10119 - Siloxane modified silica nanoparticles (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  15. 40 CFR 721.10120 - Siloxane modified alumina nanoparticles (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  16. 40 CFR 721.10119 - Siloxane modified silica nanoparticles (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  17. 40 CFR 721.10120 - Siloxane modified alumina nanoparticles (generic).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  18. 40 CFR 721.10120 - Siloxane modified alumina nanoparticles (generic).

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... meet the minimum requirements for § 721.63(a)(4): Air-purifying, tight-fitting respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters (either half- or full-face); powered air-purifying...; powered air-purifying respirator equipped with a tight-fitting facepiece (either half- or full-face)...

  19. [Endogenous respiration process analysis of heterotrophic biomass and autotrophic biomass based on respiration map ].

    PubMed

    Li, Zhi-hua; Bai, Xu-li; Zhang, Qin; Liu, Yi; He, Chun-bo

    2014-09-01

    The endogenous process is an important metabolic part of the activated sludge, and the understanding of this process is still unclear. Characteristics of endogenous respiration for heterotrophic bacteria and autotrophic nitrifiers were analyzed using respirogram. Results showed that both heterotrophic and autotrophic bacteria entered the stage of endogenous respiration at almost the same time, but heterotrophic bacteria first entered the stage of dormancy i. e. , they were easier to recover a higher proportion of biomass during the dormancy stage, indicating that heterotrophic bacteria exhibited strong environmental adaptability. Autotrophic bacteria were, however, quite different. This finding confirmed that autotrophic bacteria were more vulnerable from the viewpoint of endogenous respiration. In addition, the study also found that the increase of endogenous respiration rate ratio reflected the decreased sludge activity. And the proportion of endogenous respiration was an important parameter to characterize the activity of activated sludge, which can be used as a quantitative index for the health status of activated sludge. The findings further deepened the understanding of endogenous respiration process and provided a theoretical basis for the operation and management of wastewater treatment plants.

  20. 21 CFR 892.1970 - Radiographic ECG/respirator synchronizer.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiographic ECG/respirator synchronizer. 892.1970... (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1970 Radiographic ECG/respirator synchronizer. (a) Identification. A radiographic ECG/respirator synchronizer is a device intended to be used...

  1. 42 CFR 84.1134 - Respirator containers; minimum requirements.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Respirator containers; minimum requirements. 84... Combination Gas Masks § 84.1134 Respirator containers; minimum requirements. (a) Except as provided in paragraph (b) of this section each respirator shall be equipped with a substantial, durable...

  2. 42 CFR 84.190 - Chemical cartridge respirators: description.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Chemical cartridge respirators: description. 84.190... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.190 Chemical cartridge respirators: description. (a) Chemical...

  3. 42 CFR 84.190 - Chemical cartridge respirators: description.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Chemical cartridge respirators: description. 84.190... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.190 Chemical cartridge respirators: description. (a) Chemical...

  4. 42 CFR 84.190 - Chemical cartridge respirators: description.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Chemical cartridge respirators: description. 84.190... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.190 Chemical cartridge respirators: description. (a) Chemical...

  5. 42 CFR 84.190 - Chemical cartridge respirators: description.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Chemical cartridge respirators: description. 84.190... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.190 Chemical cartridge respirators: description. (a) Chemical...

  6. 42 CFR 84.190 - Chemical cartridge respirators: description.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Chemical cartridge respirators: description. 84.190... SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Chemical Cartridge Respirators § 84.190 Chemical cartridge respirators: description. (a) Chemical...

  7. PM 2.5 Airborne Particulates Near Frac Sand Operations.

    PubMed

    Walters, Kristin; Jacobson, Jeron; Kroening, Zachary; Pierce, Crispin

    2015-11-01

    The rapid growth of hydraulic fracturing for oil and gas extraction in the U.S. has led to 135 active "frac" sand mines, processing plants, and rail transfer stations in Wisconsin. Potential environmental health risks include increased truck traffic, noise, ecosystem loss, and groundwater, light, and air pollution. Emitted air contaminants include fine particulate matter (PM2.5) and respirable crystalline silica. Inhalation of fine dust particles causes increased mortality, cardiovascular disease, lung disease, and lung cancer. In the authors' pilot study, use of a filter-based ambient particulate monitor found PM2.5 levels of 5.82-50.8 µg/m3 in six 24-hour samples around frac sand mines and processing sites. Enforcement of the existing U.S. Environmental Protection Agency annual PM2.5 standard of 12 µg/m3 is likely to protect the public from silica exposure risks as well. PM2.5 monitoring around frac sand sites is needed to ensure regulatory compliance, inform nearby communities, and protect public health.

  8. PARTICULATE EMISSION MEASUREMENTS FROM CONTROLLED CONSTRUCTION ACTIVITIES

    EPA Science Inventory

    The report summarized the results of field testing of the effectiveness of control measures for sources of fugitive particulate emissions found at construction sites. The effectiveness of watering temporary, unpaved travel surfaces on emissions of particulate matter with aerodyna...

  9. [Contribution of wheat rhizosphere respiration to soil respiration under elevated atmospheric CO2 and nitrogen application].

    PubMed

    Kou, Tai-ji; Xu, Xiao-feng; Zhu, Jian-guo; Xie, Zu-bin; Guo, Da-yong; Miao, Yan-fang

    2011-10-01

    With the support of free-air carbon dioxide enrichment (FACE) system and by using isotope 13C technique, and through planting wheat (Triticum aestivum L., C3 crop) on a soil having been planted with maize (Zea mays L., C4 crop) for many years, this paper studied the effects of elevated atmospheric CO2 and nitrogen application on the delta 13C value of soil emitted CO2 and the wheat rhizosphere respiration. With the growth of wheat, the delta 13C value of soil emitted CO2 had a gradual decrease. Elevated atmospheric CO2 concentration (200 micromol mol(-1)) decreased the delta 13C value of emitted CO2 at booting and heading stages significantly when the nitrogen application rate was 250 kg hm(-2) (HN), and at jointing and booting stages significantly when the nitrogen application rate was 150 kg hm(-2) (LN). Nevertheless, the elevated atmospheric CO2 promoted the proportions of wheat rhizosphere respiration to soil respiration at booting and heading stages significantly. From jointing stage to maturing stage, the proportions of wheat rhizosphere respiration to soil respiration were 24%-48% (HN) and 21%-48% (LN) under elevated atmospheric CO2, and 20%-36% (HN) and 19%-32% (LN) under ambient atmospheric CO2. Under both elevated and ambient atmospheric CO2 concentrations, the delta 13C value of emitted CO2 and the rhizosphere respiration had different responses to the increased nitrogen application rate, and there was a significant interactive effect of atmospheric CO2 concentration and nitrogen application rate on the wheat rhizosphere respiration at jointing stage.

  10. Changes in soil respiration components and their specific respiration along three successional forests in the subtropics

    SciTech Connect

    Han, Tianfeng; Liu, Juxiu; Wang, Gangsheng; Huang, Wenjuan; Zhou, Guoyi

    2016-01-16

    1.Understanding how soil respiration components change with forest succession is critical for modelling and predicting soil carbon (C) processes and its sequestration below-ground. The specific respiration (a ratio of respiration to biomass) is increasingly being used as an indicator of forest succession conceptually based on Odum's theory of ecosystem development. However, the hypothesis that specific soil respiration declines with forest succession remains largely untested. 2.We used a trenching method to partition soil respiration into heterotrophic respiration and autotrophic respiration (RH and RA) and then evaluated the specific RH and specific RA in three successional forests in subtropical China. 3.Our results showed a clear seasonality in the influence of forest succession on RH, with no significant differences among the three forests in the dry season but a higher value in the old-growth forest than the other two forests in the wet season. RA in the old-growth forest tended to be the highest among the three forests. Both the specific RH and specific RA decreased with the progressive maturity of three forests. 4.Lastly, our results highlight the importance of forest succession in determining the variation of RH in different seasons. With forest succession, soil microbes and plant roots become more efficient to conserve C resources, which would result in a greater proportion of C retained in soils.

  11. A MEMS turbine prototype for respiration harvesting

    NASA Astrophysics Data System (ADS)

    Goreke, U.; Habibiabad, S.; Azgin, K.; Beyaz, M. I.

    2015-12-01

    The design, manufacturing, and performance characterization of a MEMS-scale turbine prototype is reported. The turbine is designed for integration into a respiration harvester that can convert normal human breathing into electrical power through electromagnetic induction. The device measures 10 mm in radius, and employs 12 blades located around the turbine periphery along with ball bearings around the center. Finite element simulations showed that an average torque of 3.07 μNm is induced at 12 lpm airflow rate, which lies in normal breathing levels. The turbine and a test package were manufactured using CNC milling on PMMA. Tests were performed at respiration flow rates between 5-25 lpm. The highest rotational speed was measured to be 9.84 krpm at 25 lpm, resulting in 8.96 mbar pressure drop across the device and 370 mW actuation power.

  12. Respirators, internal dose, and Oyster Creek

    SciTech Connect

    Michal, R.

    1996-06-01

    This article looks at the experience of Oyster Creek in relaxing the requirements for the use of respirators in all facets of plant maintenance, on the overall dose received by plant maintenance personnel. For Roger Shaw, director of radiological controls for three years at GPU Nuclear Corporation`s Oyster Creek nuclear plant the correct dose balance is determined on a job-by-job basis: Does the job require a respirator, which is an effective means of decreasing worker inhalation of airborne radioactive particles? Will wearing a respirator slow down a worker, consequently increasing whole body radiation exposure by prolonging the time spent in fields of high external radiation? How does respiratory protection affect worker safety and to what degree? While changes to the Nuclear Regulatory Commission`s 10CFR20 have updated the radiation protection requirements for the nuclear industry, certain of the revisions have been directed specifically at reducing worker dose, Shaw said. {open_quotes}It basically delineates that dose is dose,{close_quotes} Shaw said, {open_quotes}regardless of whether it is acquired externally or internally.{close_quotes} The revision of Part 20 changed the industry`s attitude toward internal dose, which had always been viewed negatively. {open_quotes}Internal dose was always seen as preventable by wearing respirators and by using engineering techniques such as ventilation control and decontamination,{close_quotes} Shaw said, {open_quotes}whereas external dose, although reduced where practical, was seen as a fact of the job.{close_quotes}

  13. Robust respiration detection from remote photoplethysmography

    PubMed Central

    van Gastel, Mark; Stuijk, Sander; de Haan, Gerard

    2016-01-01

    Continuous monitoring of respiration is essential for early detection of critical illness. Current methods require sensors attached to the body and/or are not robust to subject motion. Alternative camera-based solutions have been presented using motion vectors and remote photoplethysmography. In this work, we present a non-contact camera-based method to detect respiration, which can operate in both visible and dark lighting conditions by detecting the respiratory-induced colour differences of the skin. We make use of the close similarity between skin colour variations caused by the beating of the heart and those caused by respiration, leading to a much improved signal quality compared to single-channel approaches. Essentially, we propose to find the linear combination of colour channels which suppresses the distortions best in a frequency band including pulse rate, and subsequently we use this same linear combination to extract the respiratory signal in a lower frequency band. Evaluation results obtained from recordings on healthy subjects which perform challenging scenarios, including motion, show that respiration can be accurately detected over the entire range of respiratory frequencies, with a correlation coefficient of 0.96 in visible light and 0.98 in infrared, compared to 0.86 with the best-performing non-contact benchmark algorithm. Furthermore, evaluation on a set of videos recorded in a Neonatal Intensive Care Unit (NICU) shows that this technique looks promising as a future alternative to current contact-sensors showing a correlation coefficient of 0.87. PMID:28018717

  14. Radar sensitivity to human heartbeats and respiration

    NASA Astrophysics Data System (ADS)

    Aardal, Øyvind; Brovoll, Sverre; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre; Hamran, Svein-Erik

    2015-05-01

    Human heartbeats and respiration can be detected from a distance using radar. This can be used for medical applications and human being detection. It is useful to have a system independent measure of how detectable the vital signs are. In radar applications, the Radar Cross Section (RCS) is normally used to characterize the detectability of an object. Since the human vital signs are seen by the radar as movements of the torso, the modulations in the person RCS can be used as a system independent measure of the vital signs detectability. In this paper, measurements of persons seated in an anechoic chamber are presented. The measurements were calibrated using empty room and a metallic calibration sphere. A narrowband radar operating at frequencies from 500 MHz to 18 GHz in discrete steps was used. A turntable provided measurements at precise aspect angles all around the person under test. In an I & Q receiver, the heartbeat and respiration modulation is a combination of amplitude and phase mod- modulations. The measurements were filtered, leaving the modulations from the vital signs in the radar recordings. The procedure for RCS computation was applied to these filtered data, capturing the complex signatures. It was found that both the heartbeat and respiration detectability increase with increasing frequency. The heartbeat signatures are almost equal from the front and the back, while being almost undetectable from the sides of the person. The respiration signatures are slightly higher from the front than from the back, and smaller from the sides. The signature measurements presented in this paper provide an objective system independent measure of the detectability of human vital signs as a function of frequency and aspect angle. These measures are useful for example in system design and in assessing real measurement scenarios.

  15. Frost Induces Respiration and Accelerates Carbon Depletion in Trees

    PubMed Central

    Sperling, Or; Earles, J. Mason; Secchi, Francesca; Godfrey, Jessie; Zwieniecki, Maciej A.

    2015-01-01

    Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0°C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm-3 yr-1 on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics. PMID:26629819

  16. Frost Induces Respiration and Accelerates Carbon Depletion in Trees.

    PubMed

    Sperling, Or; Earles, J Mason; Secchi, Francesca; Godfrey, Jessie; Zwieniecki, Maciej A

    2015-01-01

    Cellular respiration depletes stored carbohydrates during extended periods of limited photosynthesis, e.g. winter dormancy or drought. As respiration rate is largely a function of temperature, the thermal conditions during such periods may affect non-structural carbohydrate (NSC) availability and, ultimately, recovery. Here, we surveyed stem responses to temperature changes in 15 woody species. For two species with divergent respirational response to frost, P. integerrima and P. trichocarpa, we also examined corresponding changes in NSC levels. Finally, we simulated respiration-induced NSC depletion using historical temperature data for the western US. We report a novel finding that tree stems significantly increase respiration in response to near freezing temperatures. We observed this excess respiration in 13 of 15 species, deviating 10% to 170% over values predicted by the Arrhenius equation. Excess respiration persisted at temperatures above 0 °C during warming and reoccurred over multiple frost-warming cycles. A large adjustment of NSCs accompanied excess respiration in P. integerrima, whereas P. trichocarpa neither excessively respired nor adjusted NSCs. Over the course of the years included in our model, frost-induced respiration accelerated stem NSC consumption by 8.4 mg (glucose eq.) cm(-3) yr(-1) on average in the western US, a level of depletion that may continue to significantly affect spring NSC availability. This novel finding revises the current paradigm of low temperature respiration kinetics.

  17. Organic speciation of size-segregated atmospheric particulate matter

    NASA Astrophysics Data System (ADS)

    Tremblay, Raphael

    Particle size and composition are key factors controlling the impacts of particulate matter (PM) on human health and the environment. A comprehensive method to characterize size-segregated PM organic content was developed, and evaluated during two field campaigns. Size-segregated particles were collected using a cascade impactor (Micro-Orifice Uniform Deposit Impactor) and a PM2.5 large volume sampler. A series of alkanes and polycyclic aromatic hydrocarbons (PAHs) were solvent extracted and quantified using a gas chromatograph coupled with a mass spectrometer (GC/MS). Large volume injections were performed using a programmable temperature vaporization (PTV) inlet to lower detection limits. The developed analysis method was evaluated during the 2001 and 2002 Intercomparison Exercise Program on Organic Contaminants in PM2.5 Air Particulate Matter led by the US National Institute of Standards and Technology (NIST). Ambient samples were collected in May 2002 as part of the Tampa Bay Regional Atmospheric Chemistry Experiment (BRACE) in Florida, USA and in July and August 2004 as part of the New England Air Quality Study - Intercontinental Transport and Chemical Transformation (NEAQS - ITCT) in New Hampshire, USA. Morphology of the collected particles was studied using scanning electron microscopy (SEM). Smaller particles (one micrometer or less) appeared to consist of solid cores surrounded by a liquid layer which is consistent with combustion particles and also possibly with particles formed and/or coated by secondary material like sulfate, nitrate and secondary organic aerosols. Source apportionment studies demonstrated the importance of stationary sources on the organic particulate matter observed at these two rural sites. Coal burning and biomass burning were found to be responsible for a large part of the observed PAHs during the field campaigns. Most of the measured PAHs were concentrated in particles smaller than one micrometer and linked to combustion sources

  18. Particulate matter and preterm birth

    EPA Science Inventory

    Particulate matter (PM) has been variably associated with preterm birth (PTB) (gestation <37 weeks), but the role played by specific chemical components of PM has been little studied. We examined the association between ambient PM <2.5 micrometers in aerodynamic diameter (PM2.S) ...

  19. Source Testing for Particulate Matter.

    ERIC Educational Resources Information Center

    DeVorkin, Howard

    Developed for presentation at the 12th Conference on Methods in Air Pollution and Industrial Hygiene Studies, University of Southern California, April, 1971, this outline covers procedures for the testing of particulate matter. These are: (1) basic requirements, (2) information required, (3) collection of samples, (4) processing of samples, (5)…

  20. MODELING PARTICULATE CHARGING IN ESPS

    EPA Science Inventory

    In electrostatic precipitators there is a strong interaction between the particulate space charge and the operating voltage and current of an electrical section. Calculating either the space charge or the operating point when the other is fixed is not difficult, but calculating b...

  1. Diffusion in biofilms respiring on electrodes

    SciTech Connect

    Renslow, Ryan S.; Babauta, Jerome T.; Majors, Paul D.; Beyenal, Haluk

    2012-11-15

    The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (De) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed for noninvasive, nondestructive, high spatial resolution in situ De measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensional De heat maps and surface-averaged relative effective diffusion coefficient (Drs) depth profiles. We found that (1) Drs decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; (2) Drs at a given location decreases with G. sulfurreducens biofilm age; (3) average De and Drs profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms—the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and (4) halting the respiration of a G. sulfurreducens biofilm decreases the De values. Density, reflected by De, plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms.

  2. Natural Niche for Organohalide-Respiring Chloroflexi

    PubMed Central

    Krzmarzick, Mark J.; Crary, Benjamin B.; Harding, Jevon J.; Oyerinde, Oyenike O.; Leri, Alessandra C.; Myneni, Satish C. B.

    2012-01-01

    The phylum Chloroflexi contains several isolated bacteria that have been found to respire a diverse array of halogenated anthropogenic chemicals. The distribution and role of these Chloroflexi in uncontaminated terrestrial environments, where abundant natural organohalogens could function as potential electron acceptors, have not been studied. Soil samples (116 total, including 6 sectioned cores) from a range of uncontaminated sites were analyzed for the number of Dehalococcoides-like Chloroflexi 16S rRNA genes present. Dehalococcoides-like Chloroflexi populations were detected in all but 13 samples. The concentrations of organochlorine ([organochlorine]), inorganic chloride, and total organic carbon (TOC) were obtained for 67 soil core sections. The number of Dehalococcoides-like Chloroflexi 16S rRNA genes positively correlated with [organochlorine]/TOC while the number of Bacteria 16S rRNA genes did not. Dehalococcoides-like Chloroflexi were also observed to increase in number with a concomitant accumulation of chloride when cultured with an enzymatically produced mixture of organochlorines. This research provides evidence that organohalide-respiring Chloroflexi are widely distributed as part of uncontaminated terrestrial ecosystems, they are correlated with the fraction of TOC present as organochlorines, and they increase in abundance while dechlorinating organochlorines. These findings suggest that organohalide-respiring Chloroflexi may play an integral role in the biogeochemical chlorine cycle. PMID:22101035

  3. Respirable coal mine dust sample processing

    SciTech Connect

    Raymond, L.D.; Tomb, T.F.; Parobeck, P.S.

    1987-01-01

    The Federal Coal Mine Health and Safety Act of 1969 established mandatory dust standards for coal mines. Regulatory requirements for complying with the provisions of the Act were prescribed in Title 30, Code of Federal Regulations, Parts 70 and 71, which were published in the Federal Register on April 3, 1970, and March 28, 1972, respectively. These standard and sampling requirements of coal mine operators, along with a description of the laboratory which was established to process respirable coal mine dust samples collected in accordance with these requirements, were published in MESA Informational Report (MESA, the acronym for the Mining Enforcement and Safety Administration, was changed to MSHA, the acronym for the Mine Safety and Health Administration, in 1977). These standards and regulatory requirements continued under the Federal Mine Safety and Health Act of 1977 until November 1980, when major regulatory revisions were made in the operator's dust sampling program. This paper describes the changes in the respirable coal mine dust sampling program and the equipment and procedures used by MSHA to process respirable coal mine dust samples collected in accordance with regulatory requirements. 10 figs., 1 tab.

  4. Continuous respirable mine dust monitor development

    SciTech Connect

    Cantrell, B.K.; Williams, K.L.; Stein, S.W.

    1996-12-31

    In June 1992, the Mine Safety and Health Administration (MSHA) published the Report of the Coal Mine Respirable Dust Task Group, Review of the Program to Control Respirable Coal Mine Dust in the United States. As one of its recommendations, the report called for the accelerated development of two mine dust monitors: (1) a fixed-site monitor capable of providing continuous information on dust levels to the miner, mine operator, and to MSHA, if necessary, and (2) a personal sampling device capable of providing both a short-term personal exposure measurement as well as a full-shift measurement. In response to this recommendation, the U.S. Bureau of Mines initiated the development of a fixed-site machine-mounted continuous respirable dust monitor. The technology chosen for monitor development is the Rupprecht and Patashnick Co., Inc. tapered element oscillating microbalance. Laboratory and in-mine tests have indicated that, with modification, this sensor can meet the humidity and vibration requirements for underground coal mine use. The U.S. Department of Energy Pittsburgh Research Center (DOE-PRC) is continuing that effort by developing prototypes of a continuous dust monitor based on this technology. These prototypes are being evaluated in underground coal mines as they become available. This effort, conducted as a joint venture with MSHA, is nearing completion with every promise of success.

  5. DIFFUSION IN BIOFILMS RESPIRING ON ELECTRODES

    PubMed Central

    Renslow, RS; Babauta, JT; Majors, PD; Beyenal, H

    2013-01-01

    The goal of this study was to measure spatially and temporally resolved effective diffusion coefficients (De) in biofilms respiring on electrodes. Two model electrochemically active biofilms, Geobacter sulfurreducens PCA and Shewanella oneidensis MR-1, were investigated. A novel nuclear magnetic resonance microimaging perfusion probe capable of simultaneous electrochemical and pulsed-field gradient nuclear magnetic resonance (PFG-NMR) techniques was used. PFG-NMR allowed noninvasive, nondestructive, high spatial resolution in situ De measurements in living biofilms respiring on electrodes. The electrodes were polarized so that they would act as the sole terminal electron acceptor for microbial metabolism. We present our results as both two-dimensional De heat maps and surface-averaged relative effective diffusion coefficient (Drs) depth profiles. We found that 1) Drs decreases with depth in G. sulfurreducens biofilms, following a sigmoid shape; 2) Drs at a given location decreases with G. sulfurreducens biofilm age; 3) average De and Drs profiles in G. sulfurreducens biofilms are lower than those in S. oneidensis biofilms—the G. sulfurreducens biofilms studied here were on average 10 times denser than the S. oneidensis biofilms; and 4) halting the respiration of a G. sulfurreducens biofilm decreases the De values. Density, reflected by De, plays a major role in the extracellular electron transfer strategies of electrochemically active biofilms. PMID:23420623

  6. Particulate emissions from concentrated animal feeding operations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Concentrated animal feeding operations (CAFOs), including open beef cattle feedlots, swine facilities, and poultry facilities, can emit large amounts of particulate matter, including TSP (total suspended particulates), PM10 (particulate matter with equivalent aerodynamic diameter of 10 mm or less) a...

  7. Technical Note: Particulate reactive oxygen species concentrations and their association with environmental conditions in an urban, subtropical climate

    NASA Astrophysics Data System (ADS)

    Khurshid, S. S.; Siegel, J. A.; Kinney, K. A.

    2014-02-01

    Reactions between hydrocarbons and ozone or hydroxyl radicals lead to the formation of oxidized species, including reactive oxygen species (ROS), and secondary organic aerosol (SOA) in the troposphere. ROS can be carried deep into the lungs by small aerodynamic particles where they can cause oxidative stress and cell damage. While environmental studies have focused on ROS in the gas-phase and rainwater, it is also important to determine concentrations of ROS on respirable particles. Samples of PM2.5 collected over 3 h at midday on 40 days during November 2011 and September 2012 show that the particulate ROS concentration in Austin, Texas ranged from a minimum value of 0.02 nmol H2O2 (m3 air)-1 in December to 3.81 nmol H2O2 (m3 air)-1 in September. Results from correlation tests and linear regression analysis on particulate ROS concentrations and environmental conditions (which included ozone and PM2.5 concentrations, temperature, relative humidity, precipitation and solar radiation) indicate that ambient particulate ROS is significantly influenced by the ambient ozone concentration, temperature and incident solar radiation. Particulate ROS concentrations measured in this study were in the range reported by other studies in the US, Taiwan and Singapore. This study is one of the first to assess seasonal variations in particulate ROS concentrations and helps explain the influence of environmental conditions on particulate ROS concentrations.

  8. Technical Note: Particulate reactive oxygen species concentrations and their association with environmental conditions in an urban, subtropical climate

    NASA Astrophysics Data System (ADS)

    Khurshid, S. S.; Siegel, J. A.; Kinney, K. A.

    2014-07-01

    Reactions between hydrocarbons and ozone or hydroxyl radicals lead to the formation of oxidized species, including reactive oxygen species (ROS), and secondary organic aerosol (SOA) in the troposphere. ROS can be carried deep into the lungs by small aerodynamic particles where they can cause oxidative stress and cell damage. While environmental studies have focused on ROS in the gas phase and rainwater, it is also important to determine concentrations of ROS on respirable particles. Samples of PM2.5 collected over 3 h at midday on 40 days during November 2011 and September 2012 show that the particulate ROS concentration in Austin, Texas, ranged from a minimum value of 0.02 nmoles H2O2 m-3 air in December to 3.81 nmoles H2O2 m-3 air in September. Results from correlation tests and linear regression analysis on particulate ROS concentrations and environmental conditions (which included ozone and PM2.5 concentrations, temperature, relative humidity, precipitation and solar radiation) indicate that ambient particulate ROS is significantly influenced by the ambient ozone concentration, temperature and incident solar radiation. Particulate ROS concentrations measured in this study were in the range reported by other studies in the US, Taiwan and Singapore. This study is one of the first to assess seasonal variations in particulate ROS concentrations and helps explain the influence of environmental conditions on particulate ROS concentrations.

  9. Fogging formulations for fixation of particulate contamination in ductwork and enclosures

    DOEpatents

    Maresca, Jr., Joseph W.; Kostelnik, Lori M.; Kriskivich, James R.; Demmer, Rick L.; Tripp, Julia L.

    2015-09-08

    A method and an apparatus using aqueous fixatives for fogging of ventilation ductwork, enclosures, or buildings containing dust, lint, and particulates that may be contaminated by radionuclides and other dangerous or unsafe particulate contaminants, which method and apparatus are capable of (1) obtaining full coverage within the ductwork and (2) penetrating and fixing the lint, dust and large particles present in the ductwork so that no airborne particles are released during or after the application of the fixative. New aqueous fogging solutions outperform conventional glycerin-based solutions. These aqueous solutions will fog using conventional methods of application and contain a surfactant to aid wetting and penetration of the lint and dust, a binder to stabilize loose or respirable particles, and an agent to aid in fogging and enhance adhesiveness. The solutions are safe and easy to use.

  10. Effects of photodynamic action on respiration in nonphosphorylating mitochondria.

    PubMed

    Salet, C; Moreno, G; Ricchelli, F

    1998-10-15

    We have studied the effects of singlet oxygen produced by photodynamic action on respiration in nonphosphorylating mitochondria (state 4). Isolated rat liver mitochondria were incubated with 3 microM hematoporphyrin and irradiated at 365 nm with a fluence rate of 25 W/m2. After short durations of irradiation, state 4 respiration with beta-hydroxybutyrate as substrate increases while respiration with succinate is negligibly affected. When mitochondria have been uncoupled with carbonylcyanide-p-trifluoromethoxyphenyl hydrazone before irradiation, no change occurs in beta-hydroxybutyrate-driven respiration, while succinate-driven respiration strongly decreases. Stimulation of state 4 NADH respiration cannot be explained by slippage of the NADH ubiquinone oxidoreductase because the stoichiometry of the redox pump was found insensitive to photodynamic action. In the light of the metabolite theory for linear enzymatic chains applied to state 4 respiration (Brand et al., Biochem. J. 255, 535-539, 1988), these results suggest that stimulation of NADH respiration is simply due to an increase of membrane leaks which occurs after irradiation. In the case of succinate-driven respiration, a strong inhibition of succinate dehydrogenase activity has been demonstrated after irradiation. It can be suggested that this inhibition introduces a negative control coefficient over state 4 respiration, counterbalancing the effects due to leakage.

  11. Mesozooplankton production, grazing and respiration in the Bay of Bengal: Implications for net heterotrophy

    NASA Astrophysics Data System (ADS)

    Fernandes, Veronica; Ramaiah, N.

    2016-03-01

    Mesozooplankton samples were collected from the mixed layer along a central (along 88°E) and a western transect in the Bay of Bengal during four seasons covered between 2001 and 2006 in order to investigate spatio-temporal variability in their biomass. At these stations, grazing and respiration rates were measured from live zooplankton hauled in from the surface during December 2005. Akin to the mesozooplankton "paradox" in the central and eastern Arabian Sea, biomass in the mixed layer was more or less invariant in the central and western Bay of Bengal, even as the chl a showed marginal temporal variation. By empirical equation, the mesozooplankton production rate calculated to be 70-246 mg C m- 2 d- 1 is on par with the Arabian Sea. Contrary to the conventional belief, mesozooplankton grazing impact was up to 83% on primary production (PP). Low PP coupled with very high zooplankton production (70% of PP) along with abundant bacterial production (50% of the PP; Ramaiah et al., 2009) is likely to render the Bay of Bengal net heterotrophic, especially during the spring intermonsoon. Greater estimates of fecal pellet-carbon egestion by mesozooplankton compared to the average particulate organic carbon flux in sediment traps, implies that much of the matter is recycled by heterotrophic communities in the mixed layer facilitating nutrient regeneration for phytoplankton growth. We also calculated that over a third of the primary production is channelized for basin-wide zooplankton respiration that accounts for ~ 52 Mt C annually. In the current scenario of global warming, if low (primary) productive warm pools like the Bay of Bengal continue to be net heterotrophic, negative implications like enhanced emission of CO2 to the atmosphere, increased particulate flux to the deeper waters and greater utilization of dissolved oxygen resulting in expansion of the existing oxygen minimum zone are imminent.

  12. 75 FR 35497 - Updated Guidance: Prevention Strategies for Seasonal Influenza in Healthcare Settings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-22

    ... respirators or powered air purifying respirators which would also protect against inhaling airborne particles...-pressure function of these rooms. Considering use of portable HEPA filtration units to further reduce the... respirator (i.e., N95 respirator) or higher level of protection (e.g., powered air purifying...

  13. Microbial respiration and root respiration follow divergent seasonal and diel temporal patterns in a temperate forest

    NASA Astrophysics Data System (ADS)

    Davidson, E. A.; Savage, K. E.; Tang, J.

    2010-12-01

    Soil respiration is often related to empirical measurements of soil temperature and water content, as if it were a single process that responds uniformly to these environmental drivers. However, we know that root and microbial processes both contribute to CO2 production within the soil, and the roots are connected to aboveground plant tissues, which may, in turn, be responding to other environmental cues. Trenched plots provide a method to separate these two processes, where only microbial respiration (Rm) occurs in the trenched plots that have had roots excluded, total soil respiration (Rt) occurs in untrenched reference plots, and root respiration (Rr) is inferred by the difference between the two treatments. Like all methods, this one has potential artifacts that may render the quantification of Rr uncertain, but the method is likely to demonstrate the phenology of Rr and its impact on diel and seasonal temporal patterns of Rt. We deployed three automated soil respiration chambers in both control and trenched plots at the Harvard Forest in central Massachusetts. Soil CO2 efflux was measured every half hour for each chamber from day-of-year 112 to 304, 2009 (with some data gaps in the intervening period due to equipment failure). For the combined measurement period, mean daily soil respiration and mean daily flux amplitude were significantly higher in the reference plots compared to the trenched plots. The peak flux also occurred about 2 hours later in the evening in the reference plots compared to the trenched plots. Breaking this period down into four seasonal windows (spring, early summer, late summer, and autumn), the mean daily flux was significantly higher in the reference plot for all seasons, the higher daily amplitude was significant only during the early summer, and the delay in peak emissions was significant during early and late summer. While roots were contributing to soil respiration in all measurement periods, their largest effect on daily mean

  14. Forest Soil Respiration: Identifying Sources and Controls

    NASA Astrophysics Data System (ADS)

    Högberg, P.

    2008-12-01

    Most of the respiration in forests comes from the soil. This flux is composed of two components, autotrophic and heterotrophic respiration. In a strict sense the former should be plant belowground respiration only, but the term is used here to denote respiration by roots, their mycorrhizal fungal symbionts and other closely associated organisms dependent on recent photosynthate. Heterotrophs are organisms using organic matter, chiefly above- and belowground litters, as substrate (i.e. substrates of in general much higher ecosystem age). Because of the complexity of the plant-soil system, the component fluxes are difficult to study. I will discuss results of different approaches to partition soil respiratory components and to study their controls. The focus will be on northern boreal forests. In these generally strongly nitrogen-limited forests, the autotrophic respiration equals or exceeds the heterotrophic component. The large autotrophic component reflects high plant allocation of C to roots and mycorrhizal fungi in response to the low N supply. A physiological manipulation, girdling, which stops the flow of photosynthates to roots, showed that autotrophic respiration could account for as much as 70% in N-limited forests, but only 40% in fertilized forests. Also using girdling, we could show that a shift to lower summertime temperature leads to a decrease in heterotrophic but not in autotrophic activity, suggesting substrate (photosynthate) limitation of the latter. Physiological manipulations like girdling and trenching cannot be used to reveal the finer details of soil C dynamics. Natural abundance stable isotope (13C) and 14C approaches also have their limitations if a high resolution in terms of time, space and organism is required. A very high resolution can, of course, be obtained in studies of laboratory micro- or mesocosms, but the possibility to extend the interpretation of their results to the field may be questioned. In the CANIFLEX (CArbon NItrogen

  15. Polarization signatures of airborne particulates

    NASA Astrophysics Data System (ADS)

    Raman, Prashant; Fuller, Kirk A.; Gregory, Don A.

    2013-07-01

    Exploratory research has been conducted with the aim of completely determining the polarization signatures of selected particulates as a function of wavelength. This may lead to a better understanding of the interaction between electromagnetic radiation and such materials, perhaps leading to the point detection of bio-aerosols present in the atmosphere. To this end, a polarimeter capable of measuring the complete Mueller matrix of highly scattering samples in transmission and reflection (with good spectral resolution from 300 to 1100 nm) has been developed. The polarization properties of Bacillus subtilis (surrogate for anthrax spore) are compared to ambient particulate matter species such as pollen, dust, and soot. Differentiating features in the polarization signatures of these samples have been identified, thus demonstrating the potential applicability of this technique for the detection of bio-aerosol in the ambient atmosphere.

  16. Material Instabilities in Particulate Systems

    NASA Technical Reports Server (NTRS)

    Goddard, J. D.

    1999-01-01

    Following is a brief summary of a theoretical investigation of material (or constitutive) instability associated with shear induced particle migration in dense particulate suspensions or granular media. It is shown that one can obtain a fairly general linear-stability analysis, including the effects of shear-induced anisotropy in the base flow as well as Reynolds dilatancy. A criterion is presented here for simple shearing instability in the absence of inertia and dilatancy.

  17. SOUTHERN FINE PARTICULATE MONITORING PROJECT

    SciTech Connect

    Ashley D. Williamson

    2001-07-01

    This is the third quarterly progress report of the ''Southern Fine Particulate Monitoring Project'', funded by the U.S. Department of Energy's National Energy Technology Laboratory under DOE Cooperative Agreement No. DE-FC26-00NT40770 to Southern Research Institute (SRI). In this two year project SRI will conduct detailed studies of ambient fine particulate matter in the Birmingham, AL metropolitan area. Project objectives include: Augment existing measurements of primary and secondary aerosols at an established urban southeastern monitoring site; Make a detailed database of near-continuous measurements of the time variation of fine particulate mass, composition, and key properties (including particle size distribution); Apply the measurements to source attribution, time/transport properties of fine PM, and implications for management strategies for PM{sub 2.5}; and Validate and compare key measurement methods used in this study for applicability within other PM{sub 2.5} research by DOE-FE, EPA, NARSTO, and others. During the third project quarter, the new SRI air monitoring shelter and additional instruments were installed at the site. Details include: Installation of Radiance Research M903 Nephelometer; Installation of SRI air monitoring shelter at North Birmingham Site; Relocation of instruments from SEARCH shelter to SRI shelter; Installation of Rupprecht & Patashnick 8400 Sulfate Monitor; Assembly and initial laboratory testing for particulate sulfate monitor of Harvard design; Efficiency testing of particle sizing instrument package at SRI lab; Preparation for the Eastern Supersite July measurement intensive program; and Continued monitoring with TEOM and particle sizing instruments.

  18. Tillage Effects on Soil Properties & Respiration

    NASA Astrophysics Data System (ADS)

    Rusu, Teodor; Bogdan, Ileana; Moraru, Paula; Pop, Adrian; Duda, Bogdan; Cacovean, Horea; Coste, Camelia

    2015-04-01

    Soil tillage systems can be able to influence soil compaction, water dynamics, soil temperature and soil structural condition. These processes can be expressed as changes of soil microbiological activity, soil respiration and sustainability of agriculture. Objectives of this study were: 1) to assess the effects of tillage systems (Conventional System-CS, Minimum Tillage-MT, No-Tillage-NT) on soil compaction, soil temperature, soil moisture and soil respiration and 2) to establish the relationship that exists in changing soil properties. Three treatments were installed: CS-plough + disc; MT-paraplow + rotary grape; NT-direct sowing. The study was conducted on an Argic-Stagnic Faeoziom. The MT and NT applications reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first year of application. The degree of compaction is directly related to soil type and its state of degradation. The state of soil compaction diminished over time, tending toward a specific type of soil density. Soil moisture was higher in NT and MT at the time of sowing and in the early stages of vegetation and differences diminished over time. Moisture determinations showed statistically significant differences. The MT and NT applications reduced the thermal amplitude in the first 15 cm of soil depth and increased the soil temperature by 0.5-2.20C. The determinations confirm the effect of soil tillage system on soil respiration; the daily average was lower at NT (315-1914 mmoli m-2s-1) and followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Comparing with CS, all the two conservation tillage measures decreased soil respiration, with the best effects of no-tillage. An exceeding amount of CO2 produced in the soil and released into the atmosphere, resulting from aerobic processes of mineralization of organic matter (excessive loosening) is considered to be not only a way of increasing the CO2 in the atmosphere, but also a loss of

  19. Particulate gravity currents on Venus

    NASA Astrophysics Data System (ADS)

    Waltham, Dave; Pickering, Kevin T.; Bray, Veronica J.

    2008-02-01

    Canali are moderately sinuous channels, typically a few kilometers wide and hundreds of kilometers long, that occur principally on the plains of Venus. Plausible hypotheses for their formation include the following: open channels cut by exotic, low-viscosity lavas; roofed-over basaltic lava channels; or water on a cooler, wetter ancient Venus. Although it is accepted that a fluid cut these channels, none of these hypotheses are entirely satisfactory. It is therefore prudent to investigate other explanations. A particulate gravity current is a rapidly moving, sediment-laden flow that moves downslope as a result of its high density compared to the ambient fluid. This high density is produced by suspension of dense particles in a lower-density fluid. As these flows are largely driven by slope, rather than by momentum, they are potentially capable of traveling great distances, producing extensive channel systems. We apply this process to Venus, exploring its channel-forming potential via mathematical modeling and morphological comparison of submarine channels on Earth to canali on Venus. Results of our modeling show that atmospheric particulate gravity currents are physically and geologically plausible on Venus. The potential of this process to form channels of great length is such that particulate gravity currents can be considered as an alternate explanation for canali genesis.

  20. What does respirator certification tell us about filtration of ultrafine particles?

    PubMed

    Eninger, Robert M; Honda, Takeshi; Reponen, Tiina; McKay, Roy; Grinshpun, Sergey A

    2008-05-01

    Recent interest in exposures to ultrafine particles (less than 100 nm) in both environmental and occupational settings led the authors to question whether the protocols used to certify respirator filters provide adequate attention to ultrafine aerosols. The authors reviewed the particle size distribution of challenge aerosols and evaluated the aerosol measurement method currently employed in the National Institute for Occupational Safety and Health (NIOSH) particulate respirator certification protocol for its ability to measure the contribution of ultrafine particles to filter penetration. Also considered were the differences between mechanical and electrically charged (electret) filters in light of the most penetrating particle size. It was found that the sodium chloride (NaCl) and dioctylphthalate (DOP) aerosols currently used in respirator certification tests contain a significant fraction of particles in the ultrafine region. However, the photometric method deployed in the certification test is not capable of adequately measuring light scatter of particles below approximately 100 nm in diameter. Specifically, 68% (by count) and 8% (by mass) of the challenge NaCl aerosol particles and 10% (by count) and 0.3% (by mass) of the DOP particles below 100 nm do not significantly contribute to the filter penetration measurement. In addition, the most penetrating particle size for electret filters likely occurs at 100 nm or less under test conditions similar to those used in filter certification. The authors conclude, therefore, that the existing NIOSH certification protocol may not represent a worst-case assessment for electret filters because it has limited ability to determine the contribution of ultrafine aerosols, which include the most penetrating particle size for electret filters. Possible strategies to assess ultrafine particle penetration in the certification protocol are discussed.

  1. ESTIMATING ROOT RESPIRATION IN SPRUCE AND BEECH: DECREASES IN SOIL RESPIRATION FOLLOWING GIRDLING

    EPA Science Inventory

    A study was undertaken to follow seasonal fluxes of CO2 from soil and to estimate the contribution of autotrophic (root + mycorrhizal) to total soil respiration (SR) in a mixed stand of European beech (Fagus sylvatica) and Norway spruce (Picea abies) near Freising, Germany. Matu...

  2. Soil respiration under different land uses in Eastern China.

    PubMed

    Fan, Li-Chao; Yang, Ming-Zhen; Han, Wen-Yan

    2015-01-01

    Land-use change has a crucial influence on soil respiration, which further affects soil nutrient availability and carbon stock. We monitored soil respiration rates under different land-use types (tea gardens with three production levels, adjacent woodland, and a vegetable field) in Eastern China at weekly intervals over a year using the dynamic closed chamber method. The relationship between soil respiration and environmental factors was also evaluated. The soil respiration rate exhibited a remarkable single peak that was highest in July/August and lowest in January. The annual cumulative respiration flux increased by 25.6% and 20.9% in the tea garden with high production (HP) and the vegetable field (VF), respectively, relative to woodland (WL). However, no significant differences were observed between tea gardens with medium production (MP), low production (LP), WL, and VF. Soil respiration rates were significantly and positively correlated with organic carbon, total nitrogen, and available phosphorous content. Each site displayed a significant exponential relationship between soil respiration and soil temperature measured at 5 cm depth, which explained 84-98% of the variation in soil respiration. The model with a combination of soil temperature and moisture was better at predicting the temporal variation of soil respiration rate than the single temperature model for all sites. Q10 was 2.40, 2.00, and 1.86-1.98 for VF, WL, and tea gardens, respectively, indicating that converting WL to VF increased and converting to tea gardens decreased the sensitivity of soil respiration to temperature. The equation of the multiple linear regression showed that identical factors, including soil organic carbon (SOC), soil water content (SWC), pH, and water soluble aluminum (WSAl), drove the changes in soil respiration and Q10 after conversion of land use. Temporal variations of soil respiration were mainly controlled by soil temperature, whereas spatial variations were

  3. Performance of the Volumetric Diffusive Respirator at Altitude

    DTIC Science & Technology

    2014-08-18

    AFRL-SA-WP-SR-2014-0020 Performance of the Volumetric Diffusive Respirator at Altitude Dario Rodriquez, MSc1; Tyler Britton, RRT2...the Volumetric Diffusive Respirator at Altitude 5a. CONTRACT NUMBER FA8650-12-2-6B012 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...volumetric diffusive respirator is a pneumatic ventilator used by the U.S. Army Burn Team and the U.S. Air Force Lung Team for patients with hypoxemic

  4. Ecosystem-level controls on root-rhizosphere respiration.

    PubMed

    Hopkins, Francesca; Gonzalez-Meler, Miquel A; Flower, Charles E; Lynch, Douglas J; Czimczik, Claudia; Tang, Jianwu; Subke, Jens-Arne

    2013-07-01

    Recent advances in the partitioning of autotrophic from heterotrophic respiration processes in soils in conjunction with new high temporal resolution soil respiration data sets offer insights into biotic and environmental controls of respiration. Besides temperature, many emerging controlling factors have not yet been incorporated into ecosystem-scale models. We synthesize recent research that has partitioned soil respiration into its process components to evaluate effects of nitrogen, temperature and photosynthesis on autotrophic flux from soils at the ecosystem level. Despite the widely used temperature dependence of root respiration, gross primary productivity (GPP) can explain most patterns of ecosystem root respiration (and to some extent heterotrophic respiration) at within-season time-scales. Specifically, heterotrophi crespiration is influenced by a seasonally variable supply of recent photosynthetic products in the rhizosphere. The contribution of stored root carbon (C) to root respiratory fluxes also varied seasonally, partially decoupling the proportion of photosynthetic C driving root respiration. In order to reflect recent insights, new hierarchical models, which incorporate root respiration as a primary function of GPP and which respond to environmental variables by modifying Callocation belowground, are needed for better prediction of future ecosystem C sequestration.

  5. Autotrophic and heterotrophic components of soil respiration in permafrost zone.

    NASA Astrophysics Data System (ADS)

    Udovenko, Maria; Goncharova, Olga

    2016-04-01

    Soil carbon dioxide emissions production is an important integral indicator of soil biological activity and it includes several components: the root respiration and microbial decomposition of organic matter. Separate determination of the components of soil respiration is necessary for studying the balance of carbon in the soil and to assessment its potential as a sink or source of carbon dioxide. The aim of this study was testing field methods of separate determination of root and microbial respiration in soils of north of West Siberia. The research took place near the town Nadym, Yamalo-Nenets Autonomous District (north of West Siberia).The study area was located in the northern taiga with sporadic permafrost. Investigations were carried out at two sites: in forest and in frozen peatland. 3 methods were tested for the separation of microbial and root respiration. 1) "Shading"; 2) "Clipping"(removing the above-ground green plant parts); 3)a modified method of roots exclusion (It is to compare the emission of soils of "peat spots", devoid of vegetation and roots, and soils located in close proximity to the spots on which there is herbaceous vegetation and moss). For the experiments on methods of "Shading" and "Clipping" in the forest and on the frozen peatland ware established 12 plots, 1 x 1 m (3 plots in the forest and at 9 plots on frozen peatland; 4 of them - control).The criterions for choosing location sites were the similarity of meso- and microrelief, the same depth of permafrost, the same vegetation. Measurement of carbon dioxide emissions (chamber method) was carried out once a day, in the evening, for a week. Separation the root and microbial respiration by "Shading" showed that in the forest the root respiration contribution is 5%, and microbial - 95%. On peatlands root respiration is 41%, 59% of the microbial. In the experiment "Clipping" in peatlands root respiration is 56%, the microbial respiration - 44%, in forest- root respiration is 17%, and

  6. Influences of environmental noise level and respiration rate on the accuracy of acoustic respiration rate monitoring.

    PubMed

    Yabuki, Shizuha; Toyama, Hiroaki; Takei, Yusuke; Wagatsuma, Toshihiro; Yabuki, Hiroshi; Yamauchi, Masanori

    2017-02-07

    We tested the hypothesis that the environmental noise generated by a forced-air warming system reduces the monitoring accuracy of acoustic respiration rate (RRa). Noise levels were adjusted to 45-55, 56-65, 66-75, and 76-85 dB. Healthy participants breathed at set respiration rates (RRset) of 6, 12, and 30/min. Under each noise level at each RRset, the respiration rates by manual counting (RRm) and RRa were recorded. Any appearance of the alarm display on the RRa monitor was also recorded. Each RRm of all participants agreed with each RRset at each noise level. At 45-55 dB noise, the RRa of 13, 17, and 17 participants agreed with RRset of 6, 12, and 30/min, respectively. The RRa of 14, 17, and 16 participants at 56-65 dB noise, agreed with RRset of 6, 12, and 30/min, respectively. At 66-75 dB noise, the RRa of 9, 15, and 16 participants agreed with RRset of 6, 12, and 30/min, respectively. The RRa of one, nine, and nine participants at 76-85 dB noise agreed with RRset of 6, 12, and 30/min, respectively, which was significantly less than the other noise levels (P < 0.05). Overall, 72.9% of alarm displays highlighted incorrect values of RRa. In a noisy situation involving the operation of a forced-air warming system, the acoustic respiration monitoring should be used carefully especially in patients with a low respiration rate.

  7. Bacterial respiration of arsenic and selenium

    USGS Publications Warehouse

    Stolz, J.F.; Oremland, R.S.

    1999-01-01

    Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichment culture suggest that they are widespread and metabolically active in nature. Although the bacterial species that have been isolated and characterized are still few in number, they are scattered throughout the bacterial domain and include Gram- positive bacteria, beta, gamma and epsilon Proteobacteria and the sole member of a deeply branching lineage of the bacteria, Chrysiogenes arsenatus. The oxidation of a number of organic substrates (i.e. acetate, lactate, pyruvate, glycerol, ethanol) or hydrogen can be coupled to the reduction of arsenate and selenate, but the actual donor used varies from species to species. Both periplasmic and membrane-associated arsenate and selenate reductases have been characterized. Although the number of subunits and molecular masses differs, they all contain molybdenum. The extent of the environmental impact on the transformation and mobilization of arsenic and selenium by microbial dissimilatory processes is only now being fully appreciated.

  8. Nitrogen controls spatial and temporal variability of substrate-induced respiration within seven years of bare fallow

    NASA Astrophysics Data System (ADS)

    Meyer, Nele; Bornemann, Ludger; Welp, Gerhard; Amelung, Wulf

    2015-04-01

    Bare fallow management goes along with lacking supply of new C sources; yet, little is known on the spatio-temporal controls of microbial adaptation processes. Here we hypothesized that microbial activity parameters decline upon bare fallow but that their spatial patterns are increasingly controlled by nutrient status as fallow management proceeds. To test these hypotheses, we investigated spatial and temporal patterns of substrate-induced respiration (SIR) and basal respiration curves in an arable field after 1, 3, and 7 years of bare fallow but with large within-field heterogeneity of physicochemical soil parameters. The analyses comprised the contents of SOC, mineral nitrogen (Nmin), particulate organic matter (POM), texture of the fine earth, and the proportion of rock fragments as well as basal respiration and several SIR fitting parameters (microbial biomass, microbial growth rates, peak respiration rates, cumulative CO2 release) each with and without additions of mineral N and P. We also repeated substrate (i.e. glucose) additions following the first SIR measurement. The results revealed that most respiration parameters like basal respiration, microbial biomass, and growth rates showed no or inconsistent responses to spatial and temporal patterns of basic soil properties like SOC, Nmin or texture. However, bare fallow changed the shape of the SIR curves; it developed two distinct microbial growth peaks at advanced stages of fallow, i.e. a delayed CO2 release. Likewise, the maximum respiration rate during the first growth phase declined during 7 years of fallow by 47% but its spatial distribution was always correlated with Nmin contents (r = 0.43 - 0.79). The nutrient additions suggested that these changes in SIR curves were caused by N deficiency; the first peak increased after N additions while the second growth phase diminished. Intriguingly, a repeated glucose addition had a similar effect on the SIR curves as the glucose+N addition. Thus, N deficiency

  9. Can we distinguish autotrophic respiration from heterotrophic respiration in a field site using high temporal resolution CO2 flux measurements?

    NASA Astrophysics Data System (ADS)

    Biro, Beatrice; Berger, Sina; Praetzel, Leandra; Blodau, Christian

    2016-04-01

    The processes behind C-cycling in peatlands are important to understand for assessing the vulnerability of peatlands as carbon sinks under changing climate conditions. Especially boreal peatlands are likely to underlie strong alterations in the future. It is expected that C-pools that are directly influenced by vegetation and water table fluctuations can be easily destabilized. The CO2 efflux through respiration underlies autotrophic and heterotrophic processes that show different feedbacks on changing environmental conditions. In order to understand the respiration fluxes better for more accurate modelling and prognoses, the determination of the relative importance of different respiration sources is necessary. Earlier studies used e.g. exfoliation experiments, incubation experiments or modelling approaches to estimate the different respiration sources for the total ecosystem respiration (Reco). To further the understanding in this topic, I want to distinguish autotrophic and heterotrophic respiration using high temporal resolution measurements. The study site was selected along a hydrological gradient in a peatland in southern Ontario (Canada) and measurements were conducted from May to September 2015 once per month. Environmental controls (water table, soil temperature and soil moisture) that effect the respiration sources were recorded. In my study I used a Li-COR 6400XT and a Los Gatos greenhouse gas analyzer (GGA). Reco was determined by chamber flux measurements with the GGA, while simultaneously CO2 respiration measurements on different vegetation compartments like roots, leaves and mosses were conducted using the Li-COR 6400XT. The difference between Reco and autotrophic respiration equals heterotrophic respiration. After the measurements, the vegetation plots were harvested and separated for all compartments (leaves, roots, mosses, soil organic matter), dried and weighed. The weighted respiration rates from all vegetation compartments sum up to

  10. Zone heated diesel particulate filter electrical connection

    DOEpatents

    Gonze, Eugene V.; Paratore, Jr., Michael J.

    2010-03-30

    An electrical connection system for a particulate filter is provided. The system includes: a particulate filter (PF) disposed within an outer shell wherein the PF is segmented into a plurality of heating zones; an outer mat disposed between the particulate filter and the outer shell; an electrical connector coupled to the outer shell of the PF; and a plurality of printed circuit connections that extend along the outer surface of the PF from the electrical connector to the plurality of heating zones.

  11. Diesel particulate filter with zoned resistive heater

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-03-08

    A diesel particulate filter assembly comprises a diesel particulate filter (DPF) and a heater assembly. The DPF filters a particulate from exhaust produced by an engine. The heater assembly has a first metallic layer that is applied to the DPF, a resistive layer that is applied to the first metallic layer, and a second metallic layer that is applied to the resistive layer. The second metallic layer is etched to form a plurality of zones.

  12. Observing Mean Annual Mediterranean Maquis Ecosystem Respiration

    NASA Astrophysics Data System (ADS)

    Marras, S.; Bellucco, V.; Mereu, S.; Sirca, C.; Spano, D.

    2014-12-01

    In semi arid ecosystems, extremely low Soil Water Content (SWC) values may limit ecosystem respiration (Reco) to the point of hiding the typical exponential response of respiration to temperature. This work is aimed to understand and model the Reco of an evergreen Mediterranean maquis ecosystem and to estimate the contribution of soil CO2 efflux to Reco. The selected site is located in the center of the Mediterranean sea in Sardinia (Italy). Mean annual precipitation is 588 mm and mean annual temperature is 15.9 °C. Vegetation cover is heterogeneous: 70% covered by shrubs and 30% of bare soil. Net Ecosystem Exchange (NEE) is monitored with an Eddy Covariance (EC) tower since April 2004. Soil collars were placed underneath the dominant species (Juniperus phoenicea and Pistacia lentiscus) and over the bare soil. Soil CO2 efflux was measured once a month since April 2012. Soil temperature and SWC were monitored continuously at 5 cm depth in 4 different positions close to the soil collars. Six years of EC measurements (2005-2010) and two years of soil CO2 efflux (2012-2013) measurements were analysed. Reco was estimated from the measured EC fluxes at night after filtering for adequate turbulence (u* > 1.5). Reco measurements were then binned into 1°C intervals and median values were first fitted using the Locally Estimated Scatterplot Smoothing (LOESS) method (to determine the dominant trend of the experimental curve) Reco shows an exponential increase with air and soil temperature, until SWC measured at 0.2 m depth remains above 19% vol. Secondly, the coefficients of the selected Lloyd and Taylor (1994) were estimated through the nonlinear least square (nls) method: Rref (ecosystem respiration rate at a reference temperature of 10 °C was equal to 1.65 μmol m-2 s-1 and E0 (activation energy parameter that determines the temperature sensitivity) was equal to 322.46. In addition, bare and drier soils show a reduced response of measured CO2 efflux to increasing

  13. Electrically heated particulate filter using catalyst striping

    DOEpatents

    Gonze, Eugene V; Paratore, Jr., Michael J; Ament, Frank

    2013-07-16

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating is applied to the PF that increases a temperature of the combustion of the particulates within the PF.

  14. Particulate residue separators for harvesting devices

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, John R.

    2010-06-29

    A particulate residue separator and a method for separating a particulate residue stream may include a plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams which are formed by the harvesting device and which travel, at least in part, along the plenum and in a direction of the second, exhaust end; and a baffle assembly which is located in partially occluding relation relative to the plenum, and which substantially separates the first and second particulate residue air streams.

  15. Methods of separating particulate residue streams

    DOEpatents

    Hoskinson, Reed L.; Kenney, Kevin L.; Wright, Christopher T.; Hess, J. Richard

    2011-04-05

    A particulate residue separator and a method for separating a particulate residue stream may include an air plenum borne by a harvesting device, and have a first, intake end and a second, exhaust end; first and second particulate residue air streams that are formed by the harvesting device and that travel, at least in part, along the air plenum and in a direction of the second, exhaust end; and a baffle assembly that is located in partially occluding relation relative to the air plenum and that substantially separates the first and second particulate residue air streams.

  16. Powder and particulate production of metallic alloys

    NASA Technical Reports Server (NTRS)

    Grant, N. J.

    1982-01-01

    Developments of particulate metallurgy of alloyed materials where the final products is a fully dense body are discussed. Particulates are defined as powders, flakes, foils, silvers, ribbons and strip. Because rapid solidification is an important factor in particulate metallurgy, all of the particulates must have at least one dimension which is very fine, sometimes as fine as 10 to 50 microns, but move typically up to several hundred microns, provided that the dimension permits a minimum solidification rate of at least 100 K/s.

  17. Electrically heated particulate filter embedded heater design

    DOEpatents

    Gonze, Eugene V.; Chapman, Mark R.

    2014-07-01

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine and wherein an upstream surface of the particulate filter includes machined grooves. A grid of electrically resistive material is inserted into the machined grooves of the exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF.

  18. Particulate Emissions from Gas Turbine Engines. Revision.

    DTIC Science & Technology

    1992-02-01

    with ferrocene additive) Particulate mass emissions from a J79-GE-IOB engine A-48 to A-64 Particulate mass emissions from a J52-P-6B engine A-65 to A...J79-CE-8D engine 4-9 1 with ferrocene additive (Summary of Files 34 through 45) 6 Particulate emissions from the ,J/7-G;E8f) engine 4 - 0l with... ferrocene additive (Summary of Files 46 and 47) 7 Particulate emissions from the J79-GE-8D engine 4-1i with ferrocene additive (Summary of Files 34 through

  19. Effects of MERV 16 filters and routine work practices on enclosed cabs for reducing respirable dust and DPM exposures in an underground limestone mine

    PubMed Central

    Noll, J.D.; Cecala, A.B.; J.A.Organiscak; Rider, J.P.

    2015-01-01

    An effective technique to minimize miners’ respirable dust and diesel exposure on mobile mining equipment is to place mine operators in enclosed cabs with designed filtration and pressurization systems. Many factors affect the performance of these enclosed cab systems, and one of the most significant factors is the effectiveness of the filtration system. High-efficiency particulate air (HEPA)-type filters are typically used because they are highly efficient at capturing all types and sizes of particles, including those in the submicron range such as diesel particulate matter (DPM). However, in laboratory tests, minimum efficiency reporting value (MERV) 16 filters have proven to be highly efficient for capturing DPM and respirable dust. Also, MERV 16 filters can be less restrictive to cab airflow and less expensive than HEPA filters. To verify their effectiveness in the field, MERV 16 filters were used in the enclosed cab filtration system on a face drill and roof bolting mining machine and tested at an underground limestone mine. Test results showed that DPM and respirable dust concentrations were reduced by more than 90% when the cabs were properly sealed. However, when the cab door was opened periodically throughout the shift, the reduction efficiency of the MERV 16 filters was reduced to 80% on average. PMID:26236044

  20. Combustor for fine particulate coal

    DOEpatents

    Carlson, L.W.

    1988-01-26

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

  1. Combustor for fine particulate coal

    DOEpatents

    Carlson, L.W.

    1988-11-08

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

  2. Combustor for fine particulate coal

    DOEpatents

    Carlson, Larry W.

    1988-01-01

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover.

  3. SIZE DISTRIBUTION AND RATE OF PRODUCTION OF AIRBORNE PARTICULATE MATTER GENERATED DURING METAL CUTTING

    SciTech Connect

    M.A. Ebadian, Ph.D.; S.K. Dua, Ph.D., C.H.P.; Hillol Guha, Ph.D.

    2001-01-01

    During deactivation and decommissioning activities, thermal cutting tools, such as plasma torch, laser, and gasoline torch, are used to cut metals. These activities generate fumes, smoke and particulates. These airborne species of matter, called aerosols, may be inhaled if suitable respiratory protection is not used. Inhalation of the airborne metallic aerosols has been reported to cause ill health effects, such as acute respiratory syndrome and chromosome damage in lymphocytes. In the nuclear industry, metals may be contaminated with radioactive materials. Cutting these metals, as in size reduction of gloveboxes and tanks, produces high concentrations of airborne transuranic particles. Particles of the respirable size range (size < 10 {micro}m) deposit in various compartments of the respiratory tract, the fraction and the site in the respiratory tract depending on the size of the particles. The dose delivered to the respiratory tract depends on the size distribution of the airborne particulates (aerosols) and their concentration and radioactivity/toxicity. The concentration of airborne particulate matter in an environment is dependent upon the rate of their production and the ventilation rate. Thus, measuring aerosol size distribution and generation rate is important for (1) the assessment of inhalation exposures of workers, (2) the selection of respiratory protection equipment, and (3) the design of appropriate filtration systems. Size distribution of the aerosols generated during cutting of different metals by plasma torch was measured. Cutting rates of different metals, rate of generation of respirable mass, as well as the fraction of the released kerf that become respirable were determined. This report presents results of these studies. Measurements of the particles generated during cutting of metal plates with a plasma arc torch revealed the presence of particles with mass median aerodynamic diameters of particles close to 0.2 {micro}m, arising from

  4. Cyanide-resistant Respiration in Freshly Cut Potato Slices.

    PubMed

    Rychter, A; Janes, H W; Frenkel, C

    1978-04-01

    Treating intact white potato (Solanum tuberosum L.) tuber with ethylene in air or O(2) made it possible to obtain freshly cut slices which exhibit cyanide-resistant respiration. The cyanide-resistant path requires induction in whole tubers. The data also indicate that high O(2) concentration is necessary for the full development of cyanide-resistant respiration.

  5. Respirator Speech Intelligibility Testing with an Experienced Speaker

    DTIC Science & Technology

    2015-05-01

    RESPIRATOR SPEECH INTELLIGIBILITY TESTING WITH AN EXPERIENCED...2. REPORT TYPE Final 3. DATES COVERED (From - To) Oct 2008 - Jun 2009 4. TITLE AND SUBTITLE Respirator Speech Intelligibility Testing with an...14. ABSTRACT The Modified Rhyme Test (MRT) is used by the National Institute for Occupational Safety and Health (NIOSH) to assess speech

  6. Respiration hastens maturation and lowers yield in rice.

    PubMed

    Sitaramam, V; Bhate, R; Kamalraj, P; Pachapurkar, S

    2008-07-01

    Role of respiration in plant growth remains an enigma. Growth of meristematic cells, which are not photosynthetic, is entirely driven by endogenous respiration. Does respiration determine growth and size or does it merely burn off the carbon depleting the biomass? We show here that respiration of the germinating rice seed, which is contributed largely by the meristematic cells of the embryo, quantitatively correlates with the dynamics of much of plant growth, starting with the time for germination to the time for flowering and yield. Seed respiration appears to define the quantitative phenotype that contributes to yield via growth dynamics that could be discerned even in commercial varieties, which are biased towards higher yield, despite considerable susceptibility of the dynamics to environmental perturbations. Intrinsic variation, irreducible despite stringent growth conditions, required independent validation of relevant physiological variables both by critical sampling design and by constructing dendrograms for the interrelationships between variables that yield high consensus. More importantly, seed respiration, by mediating the generation clock time via variable time for maturation as seen in rice, directly offers the plausible basis for the phenotypic variation, a major ecological stratagem in a variable environment with uncertain water availability. Faster respiring rice plants appear to complete growth dynamics sooner, mature faster, resulting in a smaller plant with lower yield. Counter to the common allometric views, respiration appears to determine size in the rice plant, and offers a valid physiological means, within the limits of intrinsic variation, to help parental selection in breeding.

  7. Soil Respiration and Student Inquiry: A Perfect Match

    ERIC Educational Resources Information Center

    Hoyt, Catherine Marie; Wallenstein, Matthew David

    2011-01-01

    This activity explores the cycling of carbon between the atmosphere (primarily as CO[subscript 2]) and biomass in plants, animals, and microscopic organisms. Students design soil respiration experiments using a protocol that resembles current practice in soil ecology. Three methods for measuring soil respiration are presented. Student-derived…

  8. 30 CFR 70.300 - Respiratory equipment; respirable dust.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respiratory equipment; respirable dust. 70.300... SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-UNDERGROUND COAL MINES Respiratory Equipment § 70.300 Respiratory equipment; respirable dust. Respiratory equipment approved by NIOSH under 42 CFR part 84 shall...

  9. Antibiotic efficacy is linked to bacterial cellular respiration.

    PubMed

    Lobritz, Michael A; Belenky, Peter; Porter, Caroline B M; Gutierrez, Arnaud; Yang, Jason H; Schwarz, Eric G; Dwyer, Daniel J; Khalil, Ahmad S; Collins, James J

    2015-07-07

    Bacteriostatic and bactericidal antibiotic treatments result in two fundamentally different phenotypic outcomes--the inhibition of bacterial growth or, alternatively, cell death. Most antibiotics inhibit processes that are major consumers of cellular energy output, suggesting that antibiotic treatment may have important downstream consequences on bacterial metabolism. We hypothesized that the specific metabolic effects of bacteriostatic and bactericidal antibiotics contribute to their overall efficacy. We leveraged the opposing phenotypes of bacteriostatic and bactericidal drugs in combination to investigate their activity. Growth inhibition from bacteriostatic antibiotics was associated with suppressed cellular respiration whereas cell death from most bactericidal antibiotics was associated with accelerated respiration. In combination, suppression of cellular respiration by the bacteriostatic antibiotic was the dominant effect, blocking bactericidal killing. Global metabolic profiling of bacteriostatic antibiotic treatment revealed that accumulation of metabolites involved in specific drug target activity was linked to the buildup of energy metabolites that feed the electron transport chain. Inhibition of cellular respiration by knockout of the cytochrome oxidases was sufficient to attenuate bactericidal lethality whereas acceleration of basal respiration by genetically uncoupling ATP synthesis from electron transport resulted in potentiation of the killing effect of bactericidal antibiotics. This work identifies a link between antibiotic-induced cellular respiration and bactericidal lethality and demonstrates that bactericidal activity can be arrested by attenuated respiration and potentiated by accelerated respiration. Our data collectively show that antibiotics perturb the metabolic state of bacteria and that the metabolic state of bacteria impacts antibiotic efficacy.

  10. 20 CFR 718.303 - Death from a respirable disease.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 20 Employees' Benefits 4 2013-04-01 2013-04-01 false Death from a respirable disease. 718.303... DISABILITY OR DEATH DUE TO PNEUMOCONIOSIS Presumptions Applicable to Eligibility Determinations § 718.303 Death from a respirable disease. (a)(1) If a deceased miner was employed for ten or more years in one...

  11. 20 CFR 718.303 - Death from a respirable disease.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 20 Employees' Benefits 3 2011-04-01 2011-04-01 false Death from a respirable disease. 718.303... DISABILITY OR DEATH DUE TO PNEUMOCONIOSIS Presumptions Applicable to Eligibility Determinations § 718.303 Death from a respirable disease. (a)(1) If a deceased miner was employed for ten or more years in one...

  12. 20 CFR 718.303 - Death from a respirable disease.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 20 Employees' Benefits 4 2012-04-01 2012-04-01 false Death from a respirable disease. 718.303... DISABILITY OR DEATH DUE TO PNEUMOCONIOSIS Presumptions Applicable to Eligibility Determinations § 718.303 Death from a respirable disease. (a)(1) If a deceased miner was employed for ten or more years in one...

  13. BACTERIAL RESPIRATION OF ARSENIC AND SELENIUM. (R826105)

    EPA Science Inventory

    Abstract

    Oxyanions of arsenic and selenium can be used in microbial anaerobic respiration as terminal electron acceptors. The detection of arsenate and selenate respiring bacteria in numerous pristine and contaminated environments and their rapid appearance in enrichme...

  14. Molecular AND logic gate based on bacterial anaerobic respiration.

    PubMed

    Arugula, Mary Anitha; Shroff, Namita; Katz, Evgeny; He, Zhen

    2012-10-21

    Enzyme coding genes that integrate information for anaerobic respiration in Shewanella oneidensis MR-1 were used as input for constructing an AND logic gate. The absence of one or both genes inhibited electrochemically-controlled anaerobic respiration, while wild type bacteria were capable of accepting electrons from an electrode for DMSO reduction.

  15. Waiting to inhale: HIF-1 modulates aerobic respiration.

    PubMed

    Boutin, Adam T; Johnson, Randall S

    2007-04-06

    The hypoxia-inducible factor HIF-1 is known to promote anaerobic respiration during low oxygen conditions (hypoxia). In this issue, Fukuda et al. (2007) expand the range of HIF-1's functions by showing that it modulates aerobic respiration as well.

  16. 78 FR 56273 - Occupational Exposure to Respirable Crystalline Silica

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-12

    ...The Occupational Safety and Health Administration (OSHA) proposes to amend its existing standards for occupational exposure to respirable crystalline silica. The basis for issuance of this proposal is a preliminary determination by the Assistant Secretary of Labor for Occupational Safety and Health that employees exposed to respirable crystalline silica face a significant risk to their health......

  17. 30 CFR 70.300 - Respiratory equipment; respirable dust.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Respiratory equipment; respirable dust. 70.300... SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-UNDERGROUND COAL MINES Respiratory Equipment § 70.300 Respiratory equipment; respirable dust. Respiratory equipment approved by NIOSH under 42 CFR part 84 shall...

  18. 30 CFR 72.700 - Respiratory equipment; respirable dust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Respiratory equipment; respirable dust. 72.700... SAFETY AND HEALTH HEALTH STANDARDS FOR COAL MINES Miscellaneous § 72.700 Respiratory equipment; respirable dust. (a) Respiratory equipment approved by NIOSH under 42 CFR part 84 shall be made available...

  19. 30 CFR 70.300 - Respiratory equipment; respirable dust.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Respiratory equipment; respirable dust. 70.300... SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-UNDERGROUND COAL MINES Respiratory Equipment § 70.300 Respiratory equipment; respirable dust. Respiratory equipment approved by NIOSH under 42 CFR part 84 shall...

  20. 30 CFR 70.300 - Respiratory equipment; respirable dust.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Respiratory equipment; respirable dust. 70.300... SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-UNDERGROUND COAL MINES Respiratory Equipment § 70.300 Respiratory equipment; respirable dust. Respiratory equipment approved by NIOSH under 42 CFR part 84 shall...

  1. 30 CFR 70.300 - Respiratory equipment; respirable dust.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Respiratory equipment; respirable dust. 70.300... SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-UNDERGROUND COAL MINES Respiratory Equipment § 70.300 Respiratory equipment; respirable dust. Respiratory equipment approved by NIOSH under 42 CFR part 84 shall...

  2. Study of contact characteristics between a respirator and a headform.

    PubMed

    Cai, Mang; Shen, Shengnan; Li, Hui; Zhang, Xiaotie; Ma, Yanzhao

    2016-01-01

    This article presents a computational study on contact characteristics of contact pressure and resultant deformation between an N95 filtering facepiece respirator and a newly developed digital headform. The geometry of the headform model is obtained based on computed tomography scanning of a volunteer. The segmentation and reconstruction of the headform model is performed by Mimics v16.0 (Materialise, Leuven, Belgium), which is a medical image processing software. The respirator model is obtained by scanning the surface of a 3M 8210 N95 respirator using a 3D digitizer and then the model is transformed by Geomagic Studio v12.0 (3D system, Rock Hill, SC), a reverse engineering software. The headform model contains a soft tissue layer, a skull layer, and a separate nose. The respirator model contains two layers (an inner face sealing layer and an outer layer) and a nose clip. Both the headform and respirator are modeled as solid elements and are deformable. The commercial software, LS-DYNA (LSTC, Livermore, CA), is used to simulate the contact between the respirator and headform. Contact pressures and resultant deformation of the headform are investigated. Effects of respirator stiffness on contact characteristics are also studied. A Matlab (MathWorks, Natick, MA) program is developed to calculate local gaps between the headform and respirator in the stable wearing state.

  3. Automatic patient respiration failure detection system with wireless transmission

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Pope, J. M.

    1968-01-01

    Automatic respiration failure detection system detects respiration failure in patients with a surgically implanted tracheostomy tube, and actuates an audible and/or visual alarm. The system incorporates a miniature radio transmitter so that the patient is unencumbered by wires yet can be monitored from a remote location.

  4. Theoretical description of RESPIRATION-CP

    NASA Astrophysics Data System (ADS)

    Nielsen, Anders B.; Tan, Kong Ooi; Shankar, Ravi; Penzel, Susanne; Cadalbert, Riccardo; Samoson, Ago; Meier, Beat H.; Ernst, Matthias

    2016-02-01

    We present a quintuple-mode operator-based Floquet approach to describe arbitrary amplitude modulated cross polarization experiments under magic-angle spinning (MAS). The description is used to analyze variants of the RESPIRATION approach (RESPIRATIONCP) where recoupling conditions and the corresponding first-order effective Hamiltonians are calculated, validated numerically and compared to experimental results for 15N-13C coherence transfer in uniformly 13C,15N-labeled alanine and in uniformly 2H,13C,15N-labeled (deuterated and 100% back-exchanged) ubiquitin at spinning frequencies of 16.7 and 90.9 kHz. Similarities and differences between different implementations of the RESPIRATIONCP sequence using either CW irradiation or small flip-angle pulses are discussed.

  5. Hot spots of soil respiration in an Asian tropical rainforest

    NASA Astrophysics Data System (ADS)

    Ohashi, Mizue; Kume, Tomonori; Yamane, Seiki; Suzuki, Masakazu

    2007-04-01

    Little is known about the variability in carbon dioxide (CO2) emissions from soil (soil respiration) in tropical rainforests. We studied temporal and spatial fluctuations of soil respiration in an intact Asian tropical rainforest. The values of soil respiration were distributed lognormally with mean and median values of 5.32 and 4.65 μmol m-2 s-1, respectively. Soil respiration varied little over time though highly in space. CO2 hot spots (>10 μmol m-2 s-1) were found with extremely high values (15-25 μmol m-2 s-1). Each CO2 hot spot occurred sporadically at different times and locations. It is hypothesized that animal activities are responsible for the hot spots. The impact of CO2 hot spots on total soil respiration was 10%, which is comparable to the estimation of net C balance in tropical rainforests.

  6. The biogeochemical reactivity of suspended particulate matter at nested sites in the Dee basin, NE Scotland.

    PubMed

    Dawson, J J C; Adhikari, Y R; Soulsby, C; Stutter, M I

    2012-09-15

    Variation in the organic matter content associated with suspended particulate matter (SPM) is an often overlooked component of carbon cycling within freshwater riverine systems. The potential biogeochemical reactivity of particulate organic carbon (POC) that affect its interactions and fate, i.e. respired and lost to the atmosphere along river continua or ultimately exported to estuarine and oceanic pools was assessed. Eleven contrasting sites draining nested catchments (5-1837 km(2)) in the River Dee basin, NE Scotland were sampled during summer 2008 to evaluate spatio-temporal variations in quantity and quality (biogeochemical reactivity) of SPM during relatively low flow conditions. Mean SPM concentrations increased from 0.21 to 1.22 mg L(-1) between the uppermost and lowest mainstem sites. Individually, POC concentrations ranged from 0.08 to 0.55 mg L(-1) and accounted for ca. 3-15% of total aqueous organic carbon transported. The POC content was partitioned into autotrophic (2.78-73.0 mg C g(-1) SPM) and detrital (119-388 mg C g(-1) SPM) biomass carbon content. The particulate respired CO(2)-C as a % of the total carbon associated with SPM, measured by MicroResp™ over 18 h, varied in recalcitrance from 0.49% at peat-dominated sites to 3.20% at the lowermost mainstem site. Significant (p<0.05) relationships were observed between SPM biogeochemical reactivity measures (% respired CO(2)-C; chlorophyll α; bioavailable-phosphorus) and arable and improved grassland area, associated with increasing biological productivity downstream. Compositional characteristics and in-stream processing of SPM appear to be related to contributory land use pressures, that influence SPM characteristics and biogeochemistry (C:N:P stoichiometry) of its surrounding aqueous environment. As moorland influences declined, nutrient inputs from arable and improved grasslands increasingly affected the biogeochemical content and reactivity of both dissolved and particulate matter. This

  7. Southern Fine Particulate Monitoring Project

    SciTech Connect

    Ashley Williamson

    2003-05-31

    This final project report presents experimental details, results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the October, 2001-September, 2002 study period.The host site for these measurement activities is the North Birmingham PM monitoring station by the Jefferson County Health Department in Birmingham, AL.The continuous data include PM{sub 2.5} mass concentrations measured by TEOM, particle sulfate using the R&P 8400S monitor, particle size distributions measured by SMPS and APS monitors, and PM{sub 2.5} light scattering extinction coefficient as measured by nephelometer. During the course of the project, measurement intercomparison data were developed for these instruments and several complementary measurements at the site. The report details the instrument set and operating procedures and describes the resulting data. Report subsections present an overview summary of the data, followed by detailed description of the systematic time behavior of PM{sub 2.5} and other specific particulate size fractions. Specific subsections are included for particle size distribution, light scattering, and particle sulfate data. The final subsection addresses application of the measurements to the practical questions of fine PM generation and transport, source attribution, and PM{sub 2.5} management strategies.

  8. PARTICULATE MATTER, OXIDATIVE STRESS AND ...

    EPA Pesticide Factsheets

    Particulate matter (PM), a component of air pollution has been epidemiologically associated with sudden deaths, cardiovascular and respiratory illnesses. The effects are more pronounced in patients with pre-existing conditions such as asthma, diabetes or obstructive pulmonary disorders. Clinical and experimental studies have historically focused on the cardiopulmonary effects of PM. However, since PM particles carry numerous biocontaminants that are capable of triggering free radical production and cytokine release, the possibility that PM may affect organs systems sensitive to oxidative stress must be considered. Four independent studies that summarize the neurochemical and neuropathological changes found in the brains of PM exposed animals are described here. These were recently presented at two 2007 symposia sponsored by the Society of Toxicology (Charlotte, NC) and the International Neurotoxicology Association (Monterey, CA). Particulates are covered with biocontaminants (e.g., endotoxins, mold, pollen) which convey free radical activity that can damage the lipids, nucleic acids, and proteins of target cells on contact and stimulate inflammatory cytokine release. Although, the historical focus of PM toxicity has been cardiopulmonary targets, it is now appreciated that inhaled nano-size (<100 nm) particles quickly exit the lungs and enter the circulation where they distribute to various organ systems (l.e., liver, kidneys, testes, lymph nodes) (Takenaka et aI

  9. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  10. Efficiency of different respiratory protective devices for removal of particulate and gaseous reactive oxygen species from welding fumes.

    PubMed

    Chen, Hsiu-Ling; Chung, Shih-Hsiang; Jhuo, Ming-Lin

    2013-01-01

    Ultraviolet (UV) light inherent to welding processes generates ozone (O(3)) with subsequent formation of reactive oxygen species (ROS) through photochemical reactions when UV light is present with O(3). This study aimed to determine the performance of filters used as respiratory protective devices by welding personnel to simultaneously mitigate particulate and gaseous inhalation hazards. Four respiratory protective devices were selected for this study, including a surgical facemask, a cotton-fabric facemask, an activated-carbon facemask, and an N95 respirator. The removal efficiencies for the particulates in welding fumes were all above 98%. For particulate-phase ROS, the removal efficiencies of the different respiratory protective devices ranged from 83.5% to 94.1%; however, the removal efficiencies for gaseous ROS were only 1.3% (active carbon facemask) to 21.1% (N95 respirator). The data indicated that the respiratory protective devices commercially available cannot block the passage of the gas-phase ROS found in welding fumes.

  11. 76 FR 3175 - Proposed Extension of Existing Information Collection; Respirator Program Records

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-19

    ... Safety and Health Administration Proposed Extension of Existing Information Collection; Respirator... miners against hazards. Where protective equipment or respirators are required because of exposure to... respirators is essential for ensuring that workers are properly and effectively using the equipment. Title...

  12. Advanced particulate matter control apparatus and methods

    DOEpatents

    Miller, Stanley J [Grand Forks, ND; Zhuang, Ye [Grand Forks, ND; Almlie, Jay C [East Grand Forks, MN

    2012-01-10

    Apparatus and methods for collection and removal of particulate matter, including fine particulate matter, from a gas stream, comprising a unique combination of high collection efficiency and ultralow pressure drop across the filter. The apparatus and method utilize simultaneous electrostatic precipitation and membrane filtration of a particular pore size, wherein electrostatic collection and filtration occur on the same surface.

  13. Air Quality Criteria for Particulate Matter.

    ERIC Educational Resources Information Center

    National Air Pollution Control Administration (DHEW), Washington, DC.

    To assist states in developing air quality standards, this book offers a review of literature related to atmospheric particulates and the development of criteria for air quality. It not only summarizes the current scientific knowledge of particulate air pollution, but points up the major deficiencies in that knowledge and the need for further…

  14. Y-12 Respirator Flow Cycle Time Reduction Project

    SciTech Connect

    Hawk, C.T.; Rogers, P.E.

    2000-12-01

    In mid-July 2000, a Cycle Time Reduction (CTR) project was initiated by senior management to improve the flow and overall efficiency of the respirator distribution process at Y-12. A cross-functional team was formed to evaluate the current process and to propose necessary changes for improvement. Specifically, the team was challenged to make improvements that would eliminate production work stoppages due to the unavailability of respirators in Y-12 Stores. Prior to the team initiation, plant back orders for a specific model respirator were averaging above 600 and have been as high as 750+. The Cycle Time Reduction team segmented the respirator flow into detailed steps, with the focus and emphasis primarily being on the movement of dirty respirators out of work areas, transportation to Oak Ridge National Laboratory (ORNL) Laundry, and return back to Y-12 Stores inventory. The team selected a popular model respirator, size large, to track improvements. Despite a 30 percent increase in respirator usage for the same period of time in the previous year, the team has reduced the back orders by 89% with a steady trend downward. Summary of accomplishments: A 47 percent reduction in the average cycle time for dirty respirators to be laundered and stocked for reuse at the Y-12 Complex; A 73 percent reduction in the average cycle time for dirty respirators to be laundered and stocked for reuse specifically for major users: Enriched Uranium Operations (EUO) and Facilities Maintenance Organization (FMO); Development of a performance measure for tracking back orders; An 89 percent reduction in the number of laundered respirators on back order; Implementation of a tracking method to account for respirator loss; Achievement of an annual cost savings/avoidance of $800K with a one-time cost of $20K; Implementation of a routine pick-up schedule for EUO (major user of respirators); Elimination of activities no longer determined to be needed; Elimination of routine complaint calls to

  15. Electrically heated particulate filter propagation support methods and systems

    DOEpatents

    Gonze, Eugene V [Pinckney, MI; Ament, Frank [Troy, MI

    2011-06-07

    A control system that controls regeneration of a particulate filter is provided. The system generally includes a regeneration module that controls current to the particulate filter to initiate combustion of particulate matter in the particulate filter. A propagation module estimates a propagation status of the combustion of the particulate matter based on a combustion temperature. A temperature adjustment module controls the combustion temperature by selectively increasing a temperature of exhaust that passes through the particulate filter.

  16. Advanced Fine Particulate Characterization Methods

    SciTech Connect

    Steven Benson; Lingbu Kong; Alexander Azenkeng; Jason Laumb; Robert Jensen; Edwin Olson; Jill MacKenzie; A.M. Rokanuzzaman

    2007-01-31

    The characterization and control of emissions from combustion sources are of significant importance in improving local and regional air quality. Such emissions include fine particulate matter, organic carbon compounds, and NO{sub x} and SO{sub 2} gases, along with mercury and other toxic metals. This project involved four activities including Further Development of Analytical Techniques for PM{sub 10} and PM{sub 2.5} Characterization and Source Apportionment and Management, Organic Carbonaceous Particulate and Metal Speciation for Source Apportionment Studies, Quantum Modeling, and High-Potassium Carbon Production with Biomass-Coal Blending. The key accomplishments included the development of improved automated methods to characterize the inorganic and organic components particulate matter. The methods involved the use of scanning electron microscopy and x-ray microanalysis for the inorganic fraction and a combination of extractive methods combined with near-edge x-ray absorption fine structure to characterize the organic fraction. These methods have direction application for source apportionment studies of PM because they provide detailed inorganic analysis along with total organic and elemental carbon (OC/EC) quantification. Quantum modeling using density functional theory (DFT) calculations was used to further elucidate a recently developed mechanistic model for mercury speciation in coal combustion systems and interactions on activated carbon. Reaction energies, enthalpies, free energies and binding energies of Hg species to the prototype molecules were derived from the data obtained in these calculations. Bimolecular rate constants for the various elementary steps in the mechanism have been estimated using the hard-sphere collision theory approximation, and the results seem to indicate that extremely fast kinetics could be involved in these surface reactions. Activated carbon was produced from a blend of lignite coal from the Center Mine in North Dakota and

  17. Molecular Characterization of Bacterial Respiration on Minerals

    SciTech Connect

    Blake, Robert C.

    2013-04-26

    The overall aim of this project was to contribute to our fundamental understanding of proteins and biological processes under extreme environmental conditions. We sought to define the biochemical and physiological mechanisms that underlie biodegradative and other cellular processes in normal, extreme, and engineered environments. Toward that end, we sought to understand the substrate oxidation pathways, the electron transport mechanisms, and the modes of energy conservation employed during respiration by bacteria on soluble iron and insoluble sulfide minerals. In accordance with these general aims, the specific aims were two-fold: To identify, separate, and characterize the extracellular biomolecules necessary for aerobic respiration on iron under strongly acidic conditions; and to elucidate the molecular principles whereby these bacteria recognize and adhere to their insoluble mineral substrates under harsh environmental conditions. The results of these studies were described in a total of nineteen manuscripts. Highlights include the following: 1. The complete genome of Acidithiobacillus ferrooxidans ATCC 23270 (type strain) was sequenced in collaboration with the DOE Joint Genome Institute; 2. Genomic and mass spectrometry-based proteomic methods were used to evaluate gene expression and in situ microbial activity in a low-complexity natural acid mine drainage microbial biofilm community. This was the first effort to successfully analyze a natural community using these techniques; 3. Detailed functional and structural studies were conducted on rusticyanin, an acid-stable electron transfer protein purified from cell-free extracts of At. ferrooxidans. The three-dimensional structure of reduced rusticyanin was determined from a combination of homonuclear proton and heteronuclear 15N- and 13C-edited NMR spectra. Concomitantly, the three-dimensional structure of oxidized rusticyanin was determined by X-ray crystallography to a resolution of 1.9 A by multiwavelength

  18. Soil Respiration Hotspots in Temperate Tidal Restored and Natural Wetlands

    NASA Astrophysics Data System (ADS)

    Scott, M.; Schafer, K. V.

    2015-12-01

    Whether a wetland is a carbon dioxide sink or source is dependent on the balance of photosynthesis and ecosystem respiration. As temperature is increasing, respiration may accelerate over photosynthesis, yet the dynamics in tidal temperate wetlands are not clear as the tidal influence impact respiration egress of the soil. Here, we investigated soil respiration of two different microsites in each a natural and a restored wetland over a range of temperature and water level conditions over the growing season. Soil respiration increased with incoming tide and was lowest under water-inundated conditions. Mudflat microsites tended to have higher soil respiration than vegetated areas, indicating sufficiently high carbon input into non-vegetated areas for high respiratory fluxes. Whereby Spartina alterniflora microsites exhibited on average lower soil respiration fluxes of about 13 micromol m-2 s-1, Spartina patens exhibited higher fluxes at about 38 micromol m2 s-1 with Phragmites australis intermediate soil respiratory fluxes. Largest spatial variation was observed for mudflat microsites.

  19. Soil Respiration in Semiarid Temperate Grasslands under Various Land Management.

    PubMed

    Wang, Zhen; Ji, Lei; Hou, Xiangyang; Schellenberg, Michael P

    2016-01-01

    Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures) on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17 μmol.m(-2).s(-1)) and clipping (2.06 μmol.m(-2).s(-1)) than under grazing (1.65 μmol.m-(2).s(-1)) over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP). Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP) and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content) and biotic (ANPP and BNPP) factors regulate soil respiration in the semiarid temperate grassland of northern China.

  20. Soil Respiration in Semiarid Temperate Grasslands under Various Land Management

    PubMed Central

    Hou, Xiangyang; Schellenberg, Michael P.

    2016-01-01

    Soil respiration, a major component of the global carbon cycle, is significantly influenced by land management practices. Grasslands are potentially a major sink for carbon, but can also be a source. Here, we investigated the potential effect of land management (grazing, clipping, and ungrazed enclosures) on soil respiration in the semiarid grassland of northern China. Our results showed the mean soil respiration was significantly higher under enclosures (2.17μmol.m−2.s−1) and clipping (2.06μmol.m−2.s−1) than under grazing (1.65μmol.m−2.s−1) over the three growing seasons. The high rates of soil respiration under enclosure and clipping were associated with the higher belowground net primary productivity (BNPP). Our analyses indicated that soil respiration was primarily related to BNPP under grazing, to soil water content under clipping. Using structural equation models, we found that soil water content, aboveground net primary productivity (ANPP) and BNPP regulated soil respiration, with soil water content as the predominant factor. Our findings highlight that management-induced changes in abiotic (soil temperature and soil water content) and biotic (ANPP and BNPP) factors regulate soil respiration in the semiarid temperate grassland of northern China. PMID:26808376

  1. Radiolytic hydrogen and microbial respiration in subsurface sediments.

    PubMed

    Blair, Carly C; D'Hondt, Steven; Spivack, Arthur J; Kingsley, Richard H

    2007-12-01

    Radiolysis of water may provide a continuous flux of an electron donor (molecular hydrogen) to subsurface microbial communities. We assessed the significance of this process in anoxic marine sediments by comparing calculated radiolytic H(2) production rates to estimates of net (organic-fueled) respiration at several Ocean Drilling Program (ODP) Leg 201 sites. Radiolytic H(2) yield calculations are based on abundances of radioactive elements (uranium, thorium, and potassium), porosity, grain density, and a model of water radiolysis. Net respiration estimates are based on fluxes of dissolved electron acceptors and their products. Comparison of radiolytic H(2) yields and respiration at multiple sites suggests that radiolysis gains importance as an electron donor source as net respiration and organic carbon content decrease. Our results suggest that radiolytic production of H(2) may fuel 10% of the metabolic respiration at the Leg 201 site where organic-fueled respiration is lowest (ODP Site 1231). In sediments with even lower rates of organic-fueled respiration, water radiolysis may be the principal source of electron donors. Marine sedimentary ecosystems may be useful models for non-photosynthetic ecosystems on early Earth and on other planets and moons, such as Mars and Europa.

  2. Alternative respiration and fumaric acid production of Rhizopus oryzae.

    PubMed

    Gu, Shuai; Xu, Qing; Huang, He; Li, Shuang

    2014-06-01

    Under the conditions of fumaric acid fermentation, Rhizopus oryzae ME-F14 possessed at least two respiratory systems. The respiration of mycelia was partially inhibited by the cytochrome respiration inhibitor antimycin A or the alternative respiration inhibitor salicylhydroxamic acid and was completely inhibited in the presence of both antimycin A and salicylhydroxamic acid. During fumaric acid fermentation process, the activity of alternative respiration had a great correlation with fumaric acid productivity; both of them reached peak at the same time. The alternative oxidase gene, which encoded the mitochondrial alternative oxidase responsible for alternative respiration in R. oryzae ME-F14, was cloned and characterized in Escherichia coli. The activity of alternative respiration, the alternative oxidase gene transcription level, as well as the fumaric acid titer were measured under different carbon sources and different carbon-nitrogen ratios. The activity of alternative respiration was found to be comparable to the transcription level of the alternative oxidase gene and the fumaric acid titer. These results indicated that the activity of the alternative oxidase was regulated at the transcription stage under the conditions tested for R. oryzae ME-F14.

  3. Respiration and sodium transport in rabbit urinary bladder.

    PubMed

    Silverthorn, S U; Eaton, D C

    1982-07-28

    Respiration of rabbit urinary bladder was measured in free-floating pieces and in short-circuited pieces mounted in an Ussing chamber. Ouabain, amiloride, and potassium-free saline inhibited respiration approx. 20%; sodium-free saline depressed respiration approx. 40-50%. The coupling ratio between respiration and transport in short-circuited tissues was about two sodium ions per molecule O2. Chloride-free saline depressed mean oxygen consumption 21% in free-floating tissue pieces; 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS) and furosemide had no effect. The effect of chloride-free saline in short-circuited tissues was variable; in tissues with low transport rates, respiration was stimulated about 21% while in tissue with high transport rates respiration was reduced about 24%. Nystatin and monensin, both of which markedly increase the conductance of cell membranes with a concomitant increase in sodium entry, stimulated respiration. These data indicate that 50-60% of the total oxygen consumption is not influenced by sodium, 20-25% is linked to (Na+ +K+)-ATPase transport, while the remaining 25-30% is sodium-dependent but not ouabain-inhibitable.

  4. Root Zone Respiration on Hydroponically Grown Wheat Plant Systems

    NASA Technical Reports Server (NTRS)

    Soler-Crespo, R. A.; Monje, O. A.

    2010-01-01

    Root respiration is a biological phenomenon that controls plant growth and physiological development during a plant's lifespan. This process is dependent on the availability of oxygen in the system where the plant is located. In hydroponic systems, where plants are submerged in a solution containing vital nutrients but no type of soil, the availability of oxygen arises from the dissolved oxygen concentration in the solution. This oxygen concentration is dependent on the , gas-liquid interface formed on the upper surface of the liquid, as given by Henry's Law, depending on pressure and temperature conditions. Respiration rates of the plants rise as biomass and root zone increase with age. The respiration rate of Apogee wheat plants (Triticum aestivum) was measured as a function of light intensity (catalytic for photosynthesis) and CO2 concentration to determine their effect on respiration rates. To determine their effects on respiration rate and plant growth microbial communities were introduced into the system, by Innoculum. Surfactants were introduced, simulating gray-water usage in space, as another factor to determine their effect on chemical oxygen demand of microbials and on respiration rates of the plants. It is expected to see small effects from changes in CO2 concentration or light levels, and to see root respiration decrease in an exponential manner with plant age and microbial activity.

  5. Radiant zone heated particulate filter

    DOEpatents

    Gonze, Eugene V [Pinckney, MI

    2011-12-27

    A system includes a particulate matter (PM) filter including an upstream end for receiving exhaust gas and a downstream end. A radiant zoned heater includes N zones, where N is an integer greater than one, wherein each of the N zones includes M sub-zones, where M is an integer greater than or equal to one. A control module selectively activates at least a selected one of the N zones to initiate regeneration in downstream portions of the PM filter from the one of the N zones, restricts exhaust gas flow in a portion of the PM filter that corresponds to the selected one of the N zones, and deactivates non-selected ones of the N zones.

  6. Methods for Coating Particulate Material

    NASA Technical Reports Server (NTRS)

    Littman, Howard (Inventor); Plawsky, Joel L. (Inventor); Paccione, John D. (Inventor)

    2013-01-01

    Methods and apparatus for coating particulate material are provided. The apparatus includes a vessel having a top and a bottom, a vertically extending conduit having an inlet in the vessel and an outlet outside of the vessel, a first fluid inlet in the bottom of the vessel for introducing a transfer fluid, a second fluid inlet in the bottom of the vessel for introducing a coating fluid, and a fluid outlet from the vessel. The method includes steps of agitating a material, contacting the material with a coating material, and drying the coating material to produce a coated material. The invention may be adapted to coat aerogel beads, among other materials. A coated aerogel bead and an aerogel-based insulation material are also disclosed.

  7. Ice particulates in the mesosphere

    NASA Technical Reports Server (NTRS)

    Chesworth, E. T.; Hale, L. C.

    1974-01-01

    The observations of noctilucent clouds, the measurements of hydrated and of large immobile ions, and the light-scattering layer detected by the OGO-6 satellite suggest the presence of particulates, probably ice, in the mesosphere. The correlation between temperature and positive ion conductivity where the vapor pressure over ice becomes greater than atmospheric pressure in the stratopause region indicates the presence of ice crystals throughout the mesosphere over a wide range of latitudes during all seasons. Between one and ten billion ice crystals per cubic meter of order 10 nanometers in diameter can dominate ionization loss processes in the mesosphere, and can explain a variety of experimental observations, including observed solar angle dependence and seasonal variability of electron density.

  8. The cytological implications of primary respiration.

    PubMed

    Crisera, P N

    2001-01-01

    Observing the macroscopic complexities of evolved species, the exceptional continuity that occurs among different cells, tissues and organs to respond coherently to the proper set of stimuli as a function of self/species survival is appreciable. Accordingly, it alludes to a central rhythm that resonates throughout the cell; nominated here as primary respiration (PR), which is capable of binding and synchronizing a diversity of physiological processes into a functional biological unity. Phylogenetically, it was conserved as an indispensable element in the makeup of the subkingdom Metazoa, since these species require a high degree of coordination among the different cells that form their body. However, it does not preclude the possibility of a basal rhythm to orchestrate the intricacies of cellular dynamics of both prokaryotic and eukaryotic cells. In all probability, PR emerges within the crucial organelles, with special emphasis on the DNA (5), and propagated and transduced within the infrastructure of the cytoskeleton as wave harmonics (49). Collectively, this equivalent vibration for the subphylum Vertebrata emanates as craniosacral respiration (CSR), though its expression is more elaborate depending on the development of the CNS. Furthermore, the author suggests that the phenomenon of PR or CSR be intimately associated to the basic rest/activity cycle (BRAC), generated by concentrically localized neurons that possess auto-oscillatory properties and assembled into a vital network (39). Historically, during Protochordate-Vertebrate transition, this area circumscribes an archaic region of the brain in which many vital biological rhythms have their source, called hindbrain rhombomeres. Bass and Baker (2) propose that pattern-generating circuits of more recent innovations, such as vocal, electromotor, extensor muscle tonicity, locomotion and the extraocular system, have their origin from the same Hox gene-specified compartments of the embryonic hindbrain (rhombomeres

  9. Influence of soil moisture on soil respiration

    NASA Astrophysics Data System (ADS)

    Fer, Miroslav; Kodesova, Radka; Nikodem, Antonin; Klement, Ales; Jelenova, Klara

    2015-04-01

    The aim of this work was to describe an impact of soil moisture on soil respiration. Study was performed on soil samples from morphologically diverse study site in loess region of Southern Moravia, Czech Republic. The original soil type is Haplic Chernozem, which was due to erosion changed into Regosol (steep parts) and Colluvial soil (base slope and the tributary valley). Soil samples were collected from topsoils at 5 points of the selected elevation transect and also from the parent material (loess). Grab soil samples, undisturbed soil samples (small - 100 cm3, and large - 713 cm3) and undisturbed soil blocks were taken. Basic soil properties were determined on grab soil samples. Small undisturbed soil samples were used to determine the soil water retention curves and the hydraulic conductivity functions using the multiple outflow tests in Tempe cells and a numerical inversion with HYDRUS 1-D. During experiments performed in greenhouse dry large undisturbed soil samples were wetted from below using a kaolin tank and cumulative water inflow due to capillary rise was measured. Simultaneously net CO2 exchange rate and net H2O exchange rate were measured using LCi-SD portable photosynthesis system with Soil Respiration Chamber. Numerical inversion of the measured cumulative capillary rise data using the HYDRUS-1D program was applied to modify selected soil hydraulic parameters for particular conditions and to simulate actual soil water distribution within each soil column in selected times. Undisturbed soil blocks were used to prepare thin soil sections to study soil-pore structure. Results for all soil samples showed that at the beginning of soil samples wetting the CO2 emission increased because of improving condition for microbes' activity. The maximum values were reached for soil column average soil water content between 0.10 and 0.15 cm3/cm3. Next CO2 emission decreased since the pore system starts filling by water (i.e. aggravated conditions for microbes

  10. Temperature response of soil respiration largely unaltered with experimental warming

    USGS Publications Warehouse

    Carey, Joanna C.; Tang, Jianwu; Templer, Pamela H.; Kroeger, Kevin D.; Crowther, Thomas W.; Burton, Andrew J.; Dukes, Jeffrey S.; Emmett, Bridget; Frey, Serita D.; Heskel, Mary A.; Jiang, Lifen; Machmuller, Megan B.; Mohan, Jacqueline; Panetta, Anne Marie; Reich, Peter B.; Reinsch, Sabine; Wang, Xin; Allison, Steven D.; Bamminger, Chris; Bridgham, Scott; Collins, Scott L.; de Dato, Giovanbattista; Eddy, William C.; Enquist, Brian J.; Estiarte, Marc; Harte, John; Henderson, Amanda; Johnson, Bart R.; Steenberg Larsen, Klaus; Luo, Yiqi; Marhan, Sven; Melillo, Jerry M.; Penuelas, Josep; Pfeifer-Meister, Laurel; Poll, Christian; Rastetter, Edward B.; Reinmann, Andrew B.; Reynolds, Lorien L.; Schmidt, Inger K.; Shaver, Gaius R.; Strong, Aaron L.; Suseela, Vidya; Tietema, Albert

    2016-01-01

    The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific attention in recent decades, the overall response of soil respiration to anticipated climatic warming remains unclear. We synthesize the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3,800 observations representing 27 temperature manipulation studies, spanning nine biomes and over 2 decades of warming. Our analysis reveals no significant differences in the temperature sensitivity of soil respiration between control and warmed plots in all biomes, with the exception of deserts and boreal forests. Thus, our data provide limited evidence of acclimation of soil respiration to experimental warming in several major biome types, contrary to the results from multiple single-site studies. Moreover, across all nondesert biomes, respiration rates with and without experimental warming follow a Gaussian response, increasing with soil temperature up to a threshold of ∼25 °C, above which respiration rates decrease with further increases in temperature. This consistent decrease in temperature sensitivity at higher temperatures demonstrates that rising global temperatures may result in regionally variable responses in soil respiration, with colder climates being considerably more responsive to increased ambient temperatures compared with warmer regions. Our analysis adds a unique cross-biome perspective on the temperature response of soil respiration, information critical to improving our mechanistic understanding of how soil carbon dynamics change with climatic warming.

  11. Temperature response of soil respiration largely unaltered with experimental warming.

    PubMed

    Carey, Joanna C; Tang, Jianwu; Templer, Pamela H; Kroeger, Kevin D; Crowther, Thomas W; Burton, Andrew J; Dukes, Jeffrey S; Emmett, Bridget; Frey, Serita D; Heskel, Mary A; Jiang, Lifen; Machmuller, Megan B; Mohan, Jacqueline; Panetta, Anne Marie; Reich, Peter B; Reinsch, Sabine; Wang, Xin; Allison, Steven D; Bamminger, Chris; Bridgham, Scott; Collins, Scott L; de Dato, Giovanbattista; Eddy, William C; Enquist, Brian J; Estiarte, Marc; Harte, John; Henderson, Amanda; Johnson, Bart R; Larsen, Klaus Steenberg; Luo, Yiqi; Marhan, Sven; Melillo, Jerry M; Peñuelas, Josep; Pfeifer-Meister, Laurel; Poll, Christian; Rastetter, Edward; Reinmann, Andrew B; Reynolds, Lorien L; Schmidt, Inger K; Shaver, Gaius R; Strong, Aaron L; Suseela, Vidya; Tietema, Albert

    2016-11-29

    The respiratory release of carbon dioxide (CO2) from soil is a major yet poorly understood flux in the global carbon cycle. Climatic warming is hypothesized to increase rates of soil respiration, potentially fueling further increases in global temperatures. However, despite considerable scientific attention in recent decades, the overall response of soil respiration to anticipated climatic warming remains unclear. We synthesize the largest global dataset to date of soil respiration, moisture, and temperature measurements, totaling >3,800 observations representing 27 temperature manipulation studies, spanning nine biomes and over 2 decades of warming. Our analysis reveals no significant differences in the temperature sensitivity of soil respiration between control and warmed plots in all biomes, with the exception of deserts and boreal forests. Thus, our data provide limited evidence of acclimation of soil respiration to experimental warming in several major biome types, contrary to the results from multiple single-site studies. Moreover, across all nondesert biomes, respiration rates with and without experimental warming follow a Gaussian response, increasing with soil temperature up to a threshold of ∼25 °C, above which respiration rates decrease with further increases in temperature. This consistent decrease in temperature sensitivity at higher temperatures demonstrates that rising global temperatures may result in regionally variable responses in soil respiration, with colder climates being considerably more responsive to increased ambient temperatures compared with warmer regions. Our analysis adds a unique cross-biome perspective on the temperature response of soil respiration, information critical to improving our mechanistic understanding of how soil carbon dynamics change with climatic warming.

  12. Time Scales in Particulate Systems

    NASA Astrophysics Data System (ADS)

    Zhang, Duan

    2013-06-01

    While there are many interests of studying interactions of individual particles, macroscopic collective behavior of particles are our main interest in many practical applications. In this talk, I will give a brief overview of the multiscale methods connecting the physics at individual particles to macroscopic quantities and averaged equations. The emphasis will be on dense dissipative particulate systems, such as powders. Unlike conservative particle systems, such as molecular systems, in a dissipative particle system the concept of thermodynamic equilibrium is not very useful unless in very special cases, because the only true thermodynamically equilibrium state in these systems is the state in which nothing moves. Other than idealized simple systems, mesoscale structures are common and important in many practical systems, especially in dissipative systems. Spatial correlations of these mesoscale structures, such as force chains in dense granular system, particle clusters and streamers in fluidized beds have received some recent attentions, partly because they can be visualized. This talk will emphasize the effects of time correlations related to the mesoscale structures. To consider time correlations and history information of the system, I will introduce the mathematical foundation of the Liouville equation, its applicability and limitations. I will derive the generalized Liouville equations for particulate systems with and without interstitial fluids, and then use them to study averaged transport equations and related closures. Interactions among the time scale of particle interactions, the time scale of the mesocale structures, and the time scale of the physical problem as represented by strain rate will be discussed. The effect of these interactions on the closure relations will be illustrated. I will also discuss possible numerical methods of solving the averaged equations, and multiscale numerical algorithms bridging the particle level calculations to

  13. Thia-arenes as source apportionment tracers for urban air particulate

    SciTech Connect

    McCarry, B.E.; Allan, L.M.; Mehta, S.; Marvin, C.H.

    1995-12-31

    Over sixty respirable air particulate samples were selected from a large number of filters collected in Hamilton, Ontario, Canada. Depending on the wind direction these sites were either predominantly upwind or predominantly downwind of the industrial sources. The sixty filters were extracted and analyzed using GC-MS for a range of PAH and sulfur-containing PAH (thia-arenes). Various reference standards (coal tar, diesel exhaust, urban air particulate) and source samples (coke oven condensate) were analyzed as well. A set of air particulate samples collected in another city alongside a highway provided an urban vehicular air sample. Unique thia-arene profiles were noted in the reference and source samples which provided the basis for this source apportionment work; two main approaches were used: (1) analysis of alkylated derivatives of thia-arenes with a molecular mass of 184 amu and (2) analysis of 234 amu isomers. The diesel exhaust and urban vehicular samples gave identical profiles while the coal tar and coke oven samples also had identical profiles but in different respects. The air samples collected at samplers located upwind of the coke ovens showed thia-arene profiles which were similar to the profile observed with a diesel exhaust reference material. However, air samples collected downwind of the coke ovens were heavily loaded samples and resembled the coal tar coke and oven condensate samples.

  14. Particulate matter pollution and population exposure assessment over mainland China in 2010 with remote sensing.

    PubMed

    Yao, Ling; Lu, Ning

    2014-05-14

    The public is increasingly concerned about particulate matter pollution caused by respirable suspended particles (PM10) and fine particles (PM2.5). In this paper, PM10 and PM2.5 concentration are estimated with remote sensing and individual air quality indexes of PM10 and PM2.5 (IPM10 and IPM2.5) over mainland China in 2010 are calculated. We find that China suffered more serious PM2.5 than PM10 pollution in 2010, and they presented a spatial differentiation. Consequently, a particulate-based air quality index (PAQI) based on a weighting method is proposed to provide a more objective assessment of the particulate pollution. The study demonstrates that, in 2010, most of mainland China faced a lightly polluted situation in PAQI case; there were three areas obviously under moderate pollution (Hubei, Sichuan-Chongqing border region and Ningxia-Inner Mongolia border region). Simultaneously, two indicators are calculated with the combination of population density gridded data to reveal Chinese population exposure to PM2.5. Comparing per capita PM2.5 concentration with population-weighted PM2.5 concentration, the former shows that the high-level regions are distributed in Guangdong, Shanghai, and Tianjin, while the latter are in Hebei, Chongqing, and Shandong. By comparison, the results demonstrate that population-weighted PM2.5 concentration is more in line with the actual situation.

  15. Quantitative respirator fit testing: dynamic pressure versus aerosol measurement.

    PubMed

    Carpenter, D R; Willeke, K

    1988-10-01

    A noninvasive, fast, inexpensive new fit testing method has been invented which relates the slope of the pressure decay inside a respirator during breath-holding to the fit of the respirator on the wearer's face. The dynamic pressure test has been compared with the conventional aerosol test at different leakage levels. The results of this comparison show that the sensitivity of the dynamic pressure test is similar to that of the aerosol test. The pressure test, however, is independent of leak site and probe location and can be performed on respirators before and after their use.

  16. Wood and foliar respiration of tropical wet forest environment

    NASA Astrophysics Data System (ADS)

    Asao, S.; Bedoya Arrieta, R.; Ryan, M. G.

    2011-12-01

    Wood and foliar respiration from tropical forests constitute major components of ecosystem respiration that may control their productivity and carbon storage. However, few estimates on tropical forests vary greatly. Furthermore, the trees in these forests respire great amounts of carbon, but impacts of individual tree species on respiration is not well known. We examined wood and foliar respiration in this environment in relation to individual tree species. The objectives of this study were to: 1) identify how respiration rates relate to scaling variables for wood and foliage, 2) examine the effects of individual tree species on these relationships, 3) extrapolate the rates to the annual fluxes of the whole stands, and 4) determine if tree species differed in these fluxes. Established on an abandoned pasture in 1988 at La Selva Biological Station in Costa Rica, the monodominant stands contained four native species in a complete randomized block design. Respiration rates based on tissue surface area ranged among dominant tree species from 0.6 to 1.0 μg C m^-2 s^-1 for small diameter wood (<10cm), 1.0 to 1.8 μg C m^-2 s^-1 for large diameter wood, and 0.7 to 0.8 μg C m^-2 s^-1 for foliage. Understory species had similar wood respiration rates, but foliage respiration rates were about half of those for canopy leaves. Among surface area, volume, or biomass, respiration rates scaled best with surface area for wood with small diameter, volume or biomass for large diameter wood, and leaf area for foliage. These relationships differed slightly among tree species and between canopy trees and understory species. Foliar respiration rate was generally related to leaf nitrogen content, and this relationship differed among dominant tree species. Temperature response of foliar respiration also differed among tree species and canopy class. However, daily and annual temperature fluctuations had less than 3% effect on annual flux. Annual respiratory fluxes from wood and foliage

  17. 40 CFR 721.10583 - Benzenamine, 4,4′-[1,3-phenylenebis(1-methylethylidene)]bis-.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-certified air-purifying, tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped... half-face or full-face) and HEPA filters. (E) NIOSH-certified supplied-air respirator operated...

  18. 40 CFR 721.10490 - HDI biuret, hydroxyethyl methacrylate prepolymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-purifying, tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil... air-purifying respirator equipped with a tight-fitting facepiece (either half-face or full-face)...

  19. 40 CFR 721.10581 - Brominated polyurethane prepolymers of methylene diphenyl diisocyanate (MDI) (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil...-certified powered air-purifying respirator equipped with a tight-fitting facepiece (either half-face or...

  20. 40 CFR 721.10607 - Aliphatic diisocyanate, homopolymer, alkanol-blocked (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...-purifying, tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil...-certified powered air-purifying respirator equipped with a tight-fitting facepiece (either half-face or...

  1. 40 CFR 721.10607 - Aliphatic diisocyanate, homopolymer, alkanol-blocked (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-purifying, tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil...-certified powered air-purifying respirator equipped with a tight-fitting facepiece (either half-face or...

  2. 40 CFR 721.10490 - HDI biuret, hydroxyethyl methacrylate prepolymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...-purifying, tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters; NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil... air-purifying respirator equipped with a tight-fitting facepiece (either half-face or full-face)...

  3. 40 CFR 721.10581 - Brominated polyurethane prepolymers of methylene diphenyl diisocyanate (MDI) (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., tight-fitting half-face respirator equipped with N100 (if oil aerosols absent), R100, or P100 filters. (B) NIOSH-certified air-purifying, tight-fitting full-face respirator equipped with N100 (if oil...-certified powered air-purifying respirator equipped with a tight-fitting facepiece (either half-face or...

  4. Arabidopsis alternative oxidase sustains Escherichia coli respiration.

    PubMed Central

    Kumar, A M; Söll, D

    1992-01-01

    Glutamyl-tRNA reductase, encoded by the hemA gene, is the first enzyme in porphyrin biosynthesis in many organisms. Hemes, important porphyrin derivatives, are essential components of redox enzymes, such as cytochromes. Thus a hemA Escherichia coli strain (SASX41B) is deficient in cytochrome-mediated aerobic respiration. Upon complementation of this strain with an Arabidopsis thaliana cDNA library, we isolated a clone which permitted the SASX41B strain to grow aerobically. The clone encodes the gene for Arabidopsis alternative oxidase, whose deduced amino acid sequence was found to have 71% identity with that of the enzyme from the voodoo lily, Sauromatum guttatum. The Arabidopsis protein is expressed as a 31-kDa protein in E. coli and confers on this organism cyanide-resistant growth, which in turn is sensitive to salicylhydroxamate. This implies that a single polypeptide is sufficient for alternative oxidase activity. Based on these observations we propose that a cyanide-insensitive respiratory pathway operates in the transformed E. coli hemA strain. Introduction of this pathway now opens the way to genetic/molecular biological investigations of alternative oxidase and its cofactor. Images PMID:1438286

  5. Salt stimulated respiration of Chlorella fusca.

    PubMed

    Löppert, H G

    1976-01-01

    ATP contents have been measured before and after addition of KCl (5 mM final concentration) to suspensions of Chlorella in distilled water under different conditions of energy supply. The levels decreased immediately after salt addition and returned to the original values under conditions both of oxidative phosphorylation and of cyclic photophosphorylation, but not under conditions of fermentation. It appears that this decrease in the ATP level is the cause for salt stimulated respiration (S.S.R.). Furthermore, it is shown that cycloheximide and EDTA, which interact with Rb+ uptake (active and ATP-driven) at low salt concentration, also reduce S.S.R. From this parallelism it is concluded that the ATPase involved in Rb+ uptake at low salt concentration is also responsible for S.S.R. at high salt concentration. As S.S.R. provides far more energy than is required for the small influx of ions it is suggested that the ATPase is decoupled by the salt from ion transport.

  6. Occupational Exposure to Respirable Dust, Respirable Crystalline Silica and Diesel Engine Exhaust Emissions in the London Tunnelling Environment.

    PubMed

    Galea, Karen S; Mair, Craig; Alexander, Carla; de Vocht, Frank; van Tongeren, Martie

    2016-03-01

    Personal 8-h shift exposure to respirable dust, diesel engine exhaust emissions (DEEE) (as respirable elemental carbon), and respirable crystalline silica of workers involved in constructing an underground metro railway tunnel was assessed. Black carbon (BC) concentrations were also assessed using a MicroAeth AE51. During sprayed concrete lining (SCL) activities in the tunnel, the geometric mean (GM) respirable dust exposure level was 0.91mg m(-3), with the highest exposure measured on a back-up sprayer (3.20mg m(-3)). The GM respirable crystalline silica concentration for SCL workers was 0.03mg m(-3), with the highest measurement also for the back-up sprayer (0.24mg m(-3)). During tunnel boring machine (TBM) activities, the GM respirable dust concentration was 0.54mg m(-3). The GM respirable elemental carbon concentration for all the TBM operators was 18 µg m(-3); with the highest concentration measured on a segment lifter. The BC concentrations were higher in the SCL environment in comparison to the TBM environment (daily GM 18-54 µg m(-3) versus 3-6 µg m(-3)). This small-scale monitoring campaign provides additional personal data on exposures experienced by underground tunnel construction workers.

  7. 42 CFR 84.1150 - Exhalation valve leakage test; minimum requirements.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  8. 42 CFR 84.1150 - Exhalation valve leakage test; minimum requirements.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  9. 42 CFR 84.1150 - Exhalation valve leakage test; minimum requirements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  10. 42 CFR 84.1150 - Exhalation valve leakage test; minimum requirements.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES APPROVAL OF RESPIRATORY PROTECTIVE DEVICES Dust, Fume, and Mist; Pesticide; Paint Spray; Powered Air-Purifying High Efficiency Respirators...

  11. Diesel particulate emission control without engine modifications

    SciTech Connect

    Filowitz, M.S.; Vataru, M.

    1989-01-01

    This paper describes an ashless, fuel supplement which was found to typically reduce diesel particulate emissions by over 30% while significantly improving fuel economy and power output without any modifications to existing diesel engines or fuels. The treating cost is an order of magnitude less than the estimated cost of reducing aromatic content at the refinery to achieve particulate reductions. The particulate reduction is virtually all from the carbon (soot) fraction. The reduced soot formation translates into less abrasives and less soot-loading stress on the engine oil. Diesel tests conducted are also discussed.

  12. Electrically heated particulate filter enhanced ignition strategy

    SciTech Connect

    Gonze, Eugene V; Paratore, Jr., Michael J

    2012-10-23

    An exhaust system that processes exhaust generated by an engine is provided. The system generally includes a particulate filter (PF) that filters particulates from the exhaust wherein an upstream end of the PF receives exhaust from the engine. A grid of electrically resistive material is applied to an exterior upstream surface of the PF and selectively heats exhaust passing through the grid to initiate combustion of particulates within the PF. A catalyst coating applied to at least one of the PF and the grid. A control module estimates a temperature of the grid and controls the engine to produce a desired exhaust product to increase the temperature of the grid.

  13. Particulate contamination spectrometer. Volume 1: Technical report

    NASA Technical Reports Server (NTRS)

    Schmitt, R. J.; Boyd, B. A.; Linford, R. M. F.

    1975-01-01

    A laser particulate spectrometer (LPS) system was developed to measure the size and speed distributions of particulate (dusts, aerosols, ice particles, etc.) contaminants. Detection of the particulates was achieved by means of light scattering and extinction effects using a single laser beam to cover a size range of 0.8 to 275 microns diameter and a speed range of 0.2 to 20 meter/second. The LPS system was designed to operate in the high vacuum environment of a space simulation chamber with cold shroud temperatures ranging from 77 to 300 K.

  14. Quantifying rhizosphere respiration for two cool-season perennial forages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the regulation of ecosystem carbon dioxide flux from forage production systems requires knowledge of component fluxes, including photosynthetic uptake and respiratory loss. Experimental separation of soil respiration into its heterotrophic (free-living soil organisms) and rhizosphere c...

  15. Effect of Pregnancy Upon Facial Anthropometrics and Respirator Fit Testing.

    PubMed

    Roberge, Raymond J; Kim, Jung-Hyun; Palmiero, Andrew; Powell, Jeffrey B

    2015-01-01

    Workers required to wear respirators must undergo additional respirator fit testing if a significant change in body weight occurs. Approximately 10% of working women of reproductive age will be pregnant and experience a significant change in weight, yet the effect of pregnancy-associated weight gain on respirator fit is unknown. Cephalo-facial anthropometric measurements and quantitative fit testing of N95 filtering facepiece respirators (N95 FFR) of 15 pregnant women and 15 matched, non-pregnant women were undertaken for comparisons between the groups. There were no significant differences between pregnant and non-pregnant women with respect to cephalo-facial anthropometric measurements or N95 FFR quantitative fit tests. Healthy pregnant workers, who adhere to the recommended weight gain limits of pregnancy, are unlikely to experience an increase in cephalo-facial dimensions that would mandate additional N95 FFR fit testing above that which is normally required on an annual basis.

  16. Respirator Use in a Hospital Setting: Establishing Surveillance Metrics.

    PubMed

    Yarbrough, Mary I; Ficken, Meredith E; Lehmann, Christoph U; Talbot, Thomas R; Swift, Melanie D; McGown, Paula W; Wheaton, Robert F; Bruer, Michele; Little, Steven W; Oke, Charles A

    Information that details use and supply of respirators in acute care hospitals is vital to prevent disease transmission, assure the safety of health care personnel, and inform national guidelines and regulations.

  17. Thoracic and respirable particle definitions for human health risk assessment

    EPA Science Inventory

    Provides estimates of the thoracic and respirable fractions, for adults and children during typical activities during both nasal and oral inhalation, that may be used in the design of experimental studies and interpretation of evidence of health effects.

  18. Replacement of filters for respirable quartz measurement in coal mine dust by infrared spectroscopy.

    PubMed

    Farcas, Daniel; Lee, Taekhee; Chisholm, William P; Soo, Jhy-Charm; Harper, Martin

    2016-01-01

    The objective of this article is to compare and characterize nylon, polypropylene (PP), and polyvinyl chloride (PVC) membrane filters that might be used to replace the vinyl/acrylic co-polymer (DM-450) filter currently used in the Mine Safety and Health Administration (MSHA) P-7 method (Quartz Analytical Method) and the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods 7603 method (QUARTZ in coal mine dust, by IR re-deposition). This effort is necessary because the DM-450 filters are no longer commercially available. There is an impending shortage of DM-450 filters. For example, the MSHA Pittsburgh laboratory alone analyzes annually approximately 15,000 samples according to the MSHA P-7 method that requires DM-450 filters. Membrane filters suitable for on-filter analysis should have high infrared (IR) transmittance in the spectral region 600-1000 cm(-1). Nylon (47 mm, 0.45 µm pore size), PP (47 mm, 0.45 µm pore size), and PVC (47 mm, 5 µm pore size) filters meet this specification. Limits of detection and limits of quantification were determined from Fourier transform infrared spectroscopy (FTIR) measurements of blank filters. The average measured quartz mass and coefficient of variation were determined from test filters spiked with respirable α-quartz following MSHA P-7 and NIOSH 7603 methods. Quartz was also quantified in samples of respirable coal dust on each test filter type using the MSHA and NIOSH analysis methods. The results indicate that PP and PVC filters may replace the DM-450 filters for quartz measurement in coal dust by FTIR. PVC filters of 5 µm pore size seemed to be suitable replacement although their ability to retain small particulates should be checked by further experiment.

  19. Replacement of filters for respirable quartz measurement in coal mine dust by infrared spectroscopy

    PubMed Central

    Farcas, Daniel; Lee, Taekhee; Chisholm, William P.; Soo, Jhy-Charm; Harper, Martin

    2015-01-01

    The objective of the present study is to compare and characterize nylon, polypropylene (PP), and polyvinyl chloride (PVC) membrane filters that might be used to replace the vinyl/acrylic co-polymer (DM-450) filter currently used in the Mine Safety and Health Administration (MSHA) P-7 method (Quartz Analytical Method) and the National Institute for Occupational Safety and Health (NIOSH) Manual of Analytical Methods 7603 method (QUARTZ in coal mine dust, by IR re-deposition). This effort is necessary because the DM-450 filters are no longer commercially available. For example, the MSHA Pittsburgh laboratory alone analyses annually approximately 15,000 samples according to the MSHA P-7 method that requires DM-450 filters. There is an impending shortage of DM-450 filters. Membrane filters suitable for on-filter analysis should have high infrared (IR) transmittance in the spectral region 600-1000 cm−1. Nylon (47 mm, 0.45 μm pore size), PP (47 mm, 0.45 μm pore size) and PVC (47 mm, 5 μm pore size) filters meet this specification. Limits of detection and limits of quantification were determined from Fourier transform infrared spectroscopy (FTIR) measurements of blank filters. The average measured quartz mass and coefficient of variation were determined from test filters spiked with respirable α-quartz following MSHA P-7 and NIOSH 7603 methods. Quartz was also quantified in samples of respirable coal dust on each test filter type using the MSHA and NIOSH analysis methods. The results indicate that PP and PVC filters may replace the DM-450 filters for quartz measurement in coal dust by FTIR. PVC filters of 5 μm pore size was seemed to be suitable replacement although their ability to retain small particulates should be checked by filter experiment. PMID:26375614

  20. Ammonium excretion and oxygen respiration of tropical copepods and euphausiids exposed to oxygen minimum zone conditions

    NASA Astrophysics Data System (ADS)

    Kiko, R.; Hauss, H.; Buchholz, F.; Melzner, F.

    2015-10-01

    Calanoid copepods and euphausiids are key components of marine zooplankton communities worldwide. Most euphausiids and several copepod species perform diel vertical migrations (DVMs) that contribute to the export of particulate and dissolved matter to midwater depths. In vast areas of the global ocean, and in particular in the eastern tropical Atlantic and Pacific, the daytime distribution depth of many migrating organisms corresponds to the core of the oxygen minimum zone (OMZ). At depth, the animals experience reduced temperature and oxygen partial pressure (pO2) and an increased carbon dioxide partial pressure (pCO2) compared to their near-surface nighttime habitat. Although it is well known that low oxygen levels can inhibit respiratory activity, the respiration response of tropical copepods and euphausiids to relevant pCO2, pO2 and temperature conditions remains poorly parameterized. Further, the regulation of ammonium excretion at OMZ conditions is generally not well understood. It was recently estimated that DVM-mediated ammonium supply considerably fuels bacterial anaerobic ammonium oxidation - a major loss process for fixed nitrogen in the ocean. These estimates were based on the implicit assumption that hypoxia or anoxia in combination with hypercapnia (elevated pCO2) does not result in a downregulation of ammonium excretion. Here we show that exposure to OMZ conditions can result in strong depression of respiration and ammonium excretion in calanoid copepods and euphausiids from the Eastern Tropical North Atlantic and the Eastern Tropical South Pacific. These physiological responses need to be taken into account when estimating DVM-mediated fluxes of carbon and nitrogen into OMZs.

  1. Tai Chi training reduced coupling between respiration and postural control

    PubMed Central

    Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

    2015-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body’s center-of-mass including those caused by spontaneous respiration. Both aging and disease increase “posturo-respiratory synchronization;” which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86±5yrs) or educational-control program (n=34, 85±6yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

  2. Stem respiration in a closed-canopy upland oak forest.

    PubMed

    Edwards, N T; Hanson, P J

    1996-04-01

    Stem respiration was measured throughout 1993 on 56 mature trees of three species (Quercus alba L., Quercus prinus L., and Acer rubrum L.) in Walker Branch Watershed, Oak Ridge, Tennessee. A subset of the trees was remeasured during 1994. Diameter increments, stem temperatures and soil water were also monitored. Respiration rates in the spring and summer of 1993 tracked growth rate increments, except during a drought when growth dropped to zero and respiration increased to its highest rate. During the dormant season, rates of total stem respiration (R(t)) tended to be greater in large trees with thick sapwood but no such trend was observed during the growing season. Before and after the growing season, respiration rates correlated well with stem temperatures. Estimated values of Q(10) were 2.4 for the two oak species and 1.7 for red maple. The Q(10) values were used along with baseline respiration measurements and stem temperatures to predict seasonal changes in maintenance respiration (R(m)). In red maple, annual total R(m) accounted for 56 and 60% of R(t) in 1993 and 1994, respectively. In chestnut oak, R(m) accounted for 65 and 58% of R(t) in 1993 and 1994, respectively. In white oak, R(m) accounted for 47 and 53% of R(t) in 1993 and 1994, respectively. Extrapolating these data to the stand level showed that woody tissue respiration accounted for 149 and 204 g C m(-2) soil surface year(-1) in 1993 and 1994, respectively.

  3. Tai Chi training reduced coupling between respiration and postural control.

    PubMed

    Holmes, Matthew L; Manor, Brad; Hsieh, Wan-hsin; Hu, Kun; Lipsitz, Lewis A; Li, Li

    2016-01-01

    In order to maintain stable upright stance, the postural control system must account for the continuous perturbations to the body's center-of-mass including those caused by spontaneous respiration. Both aging and disease increase "posturo-respiratory synchronization;" which reflects the degree to which respiration affects postural sway fluctuations over time. Tai Chi training emphasizes the coordination of respiration and bodily movements and may therefore optimize the functional interaction between these two systems. The purpose of the project was to examine the effect of Tai Chi training on the interaction between respiration and postural control in older adults. We hypothesized that Tai Chi training would improve the ability of the postural control system to compensate for respiratory perturbations and thus, reduce posturo-respiratory synchronization. Participants were recruited from supportive housing facilities and randomized to a 12-week Tai Chi intervention (n=28; 86 ± 5 yrs) or educational-control program (n=34, 85 ± 6 yrs). Standing postural sway and respiration were simultaneously recorded with a force plate and respiratory belt under eyes-open and eyes-closed conditions. Posturo-respiratory synchronization was determined by quantifying the variation of the phase relationship between the dominant oscillatory mode of respiration and corresponding oscillations within postural sway. Groups were similar in age, gender distribution, height, body mass, and intervention compliance. Neither intervention altered average sway speed, sway magnitude or respiratory rate. As compared to the education-control group, however, Tai Chi training reduced posturo-respiratory synchronization when standing with eyes open or closed (p<0.001). Tai Chi training did not affect traditional parameters of standing postural control or respiration, yet reduced the coupling between respiration and postural control. The beneficial effects of Tai Chi training may therefore stem in part

  4. Small ecosystem engineers as important regulators of lake's sediment respiration.

    NASA Astrophysics Data System (ADS)

    Baranov, Victor; Lewandowski, Joerg; Krause, Stefan; Romeijn, Paul

    2016-04-01

    Although shallow lakes are covering only about 1.5% of the land surface of the Earth, they are responsible for sequestration of carbon amounts similar or even larger than those sequestered in all marine sediments. One of the most important drivers of the carbon sequestration in lakes is sediment respiration. Especially in shallow lakes, bioturbation, i.e. the biogenic reworking of the sediment matrix and the transport of fluids within the sediment, severely impacts on sediment respiration. Widespread freshwater bioturbators such as chironomid larvae (Diptera, Chironomidae) are building tubes in the sediment and actively pump water through their burrows (ventilation). In the present work we study how different organism densities and temperatures (5-30°C) impact on respiration rates. In a microcosm experiment the bioreactive resazurin/resorufin smart tracer system was applied for quantifying the impacts of different densities of Chironomidae (Diptera) larvae (0, 1000, 2000 larvae/m2) on sediment respiration. Tracer transformation rates (and sediment respiration) were correlated with larval densities with highest transformation rates occurring in microcosms with highest larval densities. Respiration differences between defaunated sediment and sediment with 1000 and 2000 larvae per m2 was insignificant at 5 °C, and was progressively increasing with rising temperatures. At 30 °C respiration rates of sediment with 2000 larvae per m2 was 4.8 times higher than those of defaunated sediment. We interpret this as an effect of temperature on larval metabolic and locomotory activity. Furthermore, bacterial communities are benefiting from the combination of the high water temperatures and bioirrigation as bacterial community are able to maintain high metabolic rates due to oxygen supplied by bioirrigation. In the context of global climate change that means that chironomid ecosystem engineering activity will have a profound and increasing impact on lake sediment respiration

  5. Stimulation of respiration in rat thymocytes induced by ionizing radiation.

    PubMed

    Gudz, T I; Pandelova, I G; Novgorodov, S A

    1994-04-01

    The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La3+ and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation.

  6. Development of a Molecular System for Studying Microbial Arsenate Respiration

    NASA Astrophysics Data System (ADS)

    Saltikov, C. W.; Newman, D. K.

    2002-12-01

    The toxic element arsenic is a major contaminant of many groundwaters and surface waters throughout the world. Arsenic enrichment is primarily of geological origin resulting from weathering processes and geothermal activity. Not surprisingly, microorganisms inhabiting anoxic arsenic-contaminated environments have evolved to exploit arsenate during respiration. Numerous bacteria have been isolated that use arsenate as a terminal electron acceptor for respiratory growth. The diversity of this metabolism appears to be widespread throughout the microbial tree of life, suggesting respiratory arsenate reduction is ancient in origin. Yet little is known about the molecular mechanisms for how these organisms respire arsenate. We have developed a model system in Shewanella trabarsenatis, strain ANA-3, a facultative anaerobe that respires arsenate and tolerates high concentrations of arsenite (10 mM). Through loss-of-function studies, we have identified genes involved in both arsenic resistance and arsenate respiration. The genes that confer resistance to arsenic are homologous to the well-characterized ars operon of E. coli. However, the respiratory arsenate reductase is predicted to encode a novel protein that shares homologous regions (~ 40 % similarity) to molybdopterin anaerobic reductases specific for DMSO, thiosulfate, nitrate, and polysulfide. I will discuss our emerging model for how strain ANA-3 respires arsenate and the relationship between arsenite resistance and arsenate respiration. I will also highlight the relevance of this type of analysis for biogeochemical studies.

  7. Multi-Scale Modeling of Respiration: Linking External to Cellular Respiration during Exercise

    PubMed Central

    Zhou, Haiying; Lai, Nicola; Saidel, Gerald M.; Cabrera, Marco E.

    2014-01-01

    In human studies investigating factors that control cellular respiration in working skeletal muscle, pulmonary VO2 dynamics (VO2p) measured at the mouth by indirect calorimetry is typically used to represent muscle O2 consumption (UO2m). Furthermore, measurement of muscle oxygenation using near-infrared spectroscopy has provided information on the dynamic balance between oxygen delivery and oxygen consumption at the microvascular level. To relate these measurements and gain quantitative understanding of the regulation of VO2 at the cellular, tissue and whole-body level, a multiscale computational model of oxygen transport and metabolism during exercise was developed. The model incorporates mechanisms of oxygen transport from the airway opening to working muscle and other-organs cells, as well as the phosphagenic and oxidative pathways of ATP synthesis in these tissue cells. Model simulations of external (VO2p) and cellular (UO2m) respiration show that, during moderate exercise, their characteristic mean response times are similar even when a transit delay exists between tissue cells and the external environment for normal subjects. PMID:19457732

  8. Surfactants and the Mechanics of Respiration

    NASA Astrophysics Data System (ADS)

    Jbaily, Abdulrahman; Szeri, Andrew J.

    2016-11-01

    Alveoli are small sacs found at the end of terminal bronchioles in human lungs with a mean diameter of 200 μm. A thin layer of fluid (hypophase) coats the inner face of an alveolus and is in contact with the air in the lungs. The thickness of this layer varies among alveoli, but is in the range of 0.1 to 0.5 μm for many portions of the alveolar network. The interfacial tension σ at the air-hypophase interface tends to favor collapse of the alveolus, and resists its expansion during inhalation. Type II alveolar cells synthesize and secrete a mixture of phospholipids and proteins called pulmonary surfactant. These surfactant molecules adsorb to the interface causing σ of water at body temperature is 70 mN/m and falls to an equilibrium value of 25 mN/m when surfactants are present. Also, in a dynamic sense, it is known that σ is reduced to near 0 during exhalation when the surfactant film compresses. In this work, the authors develop a mechanical and transport model of the alveolus to study the effect of surfactants on various aspects of respiration. The model is composed of three principal parts: (i) air movement into and out of the alveolus; (ii) a balance of linear momentum across the two-layered membrane of the alveolus (hypophase and elastic wall); and (iii) a pulmonary surfactant transport problem in the hypophase. The goal is to evaluate the influence of pulmonary surfactant on respiratory mechanics.

  9. Characterization of particulate-bound PAHs in rural households using different types of domestic energy in Henan Province, China.

    PubMed

    Wu, Fuyong; Liu, Xueping; Wang, Wei; Man, Yu Bon; Chan, Chuen Yu; Liu, Wenxin; Tao, Shu; Wong, Ming Hung

    2015-12-01

    The concentrations and composition of sixteen PAHs adsorbed to respirable particulate matter (PM10≤10 μm) and inhalable particulate matter (PM2.5≤2.5 μm) were determined during autumn and winter in rural households of Henan Province, China, which used four types of domestic energy [crop residues, coal, liquid petroleum gas (LPG) and electricity] for cooking and heating. The present results show that there were significantly (p<0.05) seasonal variations of particulate-bound PAHs in the rural households. The daily mean concentrations of particulate-bound PAHs in the kitchens, sitting rooms and outdoors were apparently higher in winter than those in autumn, except those in the kitchens using coal. The present study also shows that there were obvious variations of particulate-bound PAHs among the four types of domestic energy used in the rural households. The households using LPG for cooking can, at least in some circumstances, have higher concentrations of PAHs in the kitchens than using crop residues or electricity. In addition, using coal in the sitting rooms seemed to result in apparently higher concentrations of particulate-bound PAHs than using the other three types of domestic energy during winter. The most severe contamination occurred in the kitchens using LPG in winter, where the daily mean concentrations of PM2.5-bound PAHs were up to 762.5±931.2 ng m(-3), indicating that there was serious health risk of inhalation exposure to PAHs in the rural households of Henan Province. Rural residents' exposure to PM2.5-bound PAHs in kitchens would be roughly reduced by 69.8% and 85.5% via replacing coal or crop residues with electricity in autumn. The pilot research would provide important supplementary information to the indoor air pollution studies in rural area.

  10. 40 CFR 60.422 - Standards for particulate matter.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for particulate matter. 60... Manufacture § 60.422 Standards for particulate matter. On or after the date on which the performance test... sulfate dryer, particulate matter at an emission rate exceeding 0.15 kilogram of particulate per...

  11. 40 CFR 60.422 - Standards for particulate matter.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Standards for particulate matter. 60... Manufacture § 60.422 Standards for particulate matter. On or after the date on which the performance test... sulfate dryer, particulate matter at an emission rate exceeding 0.15 kilogram of particulate per...

  12. 40 CFR 60.422 - Standards for particulate matter.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Standards for particulate matter. 60... Manufacture § 60.422 Standards for particulate matter. On or after the date on which the performance test... sulfate dryer, particulate matter at an emission rate exceeding 0.15 kilogram of particulate per...

  13. 30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Respirable dust control plan; approval by... WORK AREAS OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.301 Respirable dust control... control plans on a mine-by-mine basis. When approving respirable dust control plans, the District...

  14. 30 CFR 90.300 - Respirable dust control plan; filing requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Respirable dust control plan; filing... DEVELOPMENT OF PNEUMOCONIOSIS Respirable Dust Control Plans § 90.300 Respirable dust control plan; filing... part 90 miner, the operator shall submit a written respirable dust control plan for that part 90...

  15. 30 CFR 71.300 - Respirable dust control plan; filing requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Respirable dust control plan; filing... OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.300 Respirable dust control plan; filing... submit to the District Manager for approval a written respirable dust control plan applicable to the...

  16. 30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Respirable dust control plan; approval by... WORK AREAS OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.301 Respirable dust control... control plans on a mine-by-mine basis. When approving respirable dust control plans, the District...

  17. 30 CFR 90.300 - Respirable dust control plan; filing requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust control plan; filing... DEVELOPMENT OF PNEUMOCONIOSIS Respirable Dust Control Plans § 90.300 Respirable dust control plan; filing... part 90 miner, the operator shall submit a written respirable dust control plan for that part 90...

  18. 30 CFR 71.300 - Respirable dust control plan; filing requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Respirable dust control plan; filing... OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.300 Respirable dust control plan; filing... submit to the District Manager for approval a written respirable dust control plan applicable to the...

  19. 30 CFR 71.301 - Respirable dust control plan; approval by District Manager and posting.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust control plan; approval by... WORK AREAS OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.301 Respirable dust control... control plans on a mine-by-mine basis. When approving respirable dust control plans, the District...

  20. 30 CFR 90.300 - Respirable dust control plan; filing requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Respirable dust control plan; filing... DEVELOPMENT OF PNEUMOCONIOSIS Respirable Dust Control Plans § 90.300 Respirable dust control plan; filing... part 90 miner, the operator shall submit a written respirable dust control plan for that part 90...

  1. 30 CFR 71.300 - Respirable dust control plan; filing requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Respirable dust control plan; filing... OF UNDERGROUND COAL MINES Respirable Dust Control Plans § 71.300 Respirable dust control plan; filing... submit to the District Manager for approval a written respirable dust control plan applicable to the...

  2. 42 CFR 84.253 - Chemical-cartridge respirators; requirements and tests.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Chemical-cartridge respirators; requirements and... DEVICES Special Use Respirators § 84.253 Chemical-cartridge respirators; requirements and tests. (a... for chemical-cartridge respirators prescribed in Subpart L of this part are applicable to...

  3. 46 CFR Appendix E to Subpart C of... - Respirator Fit Tests

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Respirator Fit Tests E Appendix E to Subpart C of Part...—Respirator Fit Tests Procedures This appendix contains the procedures for properly fitting a respirator to... (QLFT), and the Quantitative Fit Test (QNFT). Note that respirators (negative pressure or...

  4. 46 CFR Appendix E to Subpart C of... - Respirator Fit Tests

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Respirator Fit Tests E Appendix E to Subpart C of Part...—Respirator Fit Tests Procedures This appendix contains the procedures for properly fitting a respirator to... (QLFT), and the Quantitative Fit Test (QNFT). Note that respirators (negative pressure or...

  5. 46 CFR Appendix E to Subpart C of... - Respirator Fit Tests

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Respirator Fit Tests E Appendix E to Subpart C of Part...—Respirator Fit Tests Procedures This appendix contains the procedures for properly fitting a respirator to... (QLFT), and the Quantitative Fit Test (QNFT). Note that respirators (negative pressure or...

  6. 46 CFR Appendix E to Subpart C to... - Respirator Fit Tests

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Respirator Fit Tests E Appendix E to Subpart C to Part...—Respirator Fit Tests Procedures This appendix contains the procedures for properly fitting a respirator to... (QLFT), and the Quantitative Fit Test (QNFT). Note that respirators (negative pressure or...

  7. PARTICULATE MATTER, OXIDATIVE STRESS AND NEUROTOXICITY

    EPA Science Inventory

    Particulate matter (PM), a component of air pollution has been epidemiologically associated with sudden deaths, cardiovascular and respiratory illnesses. The effects are more pronounced in patients with pre-existing conditions such as asthma, diabetes or obstructive pulmonary dis...

  8. Particulate matter, oxidative stress and neurotoxicity.

    EPA Science Inventory

    Particulate matter (PM), a component of air pollution has been epidemiologically associated with sudden deaths, cardiovascular and respiratory illnesses. The effects are more pronounced in patients with pre-existing conditions such as asthma, diabetes or obstructive pulmonary dis...

  9. OPEN PATH OPTICAL SENSING OF PARTICULATE MATTER

    EPA Science Inventory

    The paper discusses the concepts behind recent developments in optical remote sensing (ORS) and the results from experiments. Airborne fugitive and fine particulate matter (PM) from various sources contribute to exceedances of state and federal PM and visibility standards. Recent...

  10. Particulate Matter (Environmental Health Student Portal)

    MedlinePlus

    ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Videos Games Experiments For Teachers Home ... Pollutants Natural Disasters Drinking Water Waterborne Diseases & Illnesses Water Cycle Water Treatment Particulate Matter The Basics We’ve ...

  11. MTCI acoustic agglomeration particulate control

    SciTech Connect

    Chandran, R.R.; Mansour, M.N.; Scaroni, A.W.; Koopmann, G.H.; Loth, J.L.

    1994-10-01

    The overall objective of this project is to demonstrate pulse combination induced acoustic enhancement of coal ash agglomeration and sulfur capture at conditions typical of direct coal-fired turbines and PFBC hot gas cleanup. MTCI has developed an advanced compact pulse combustor island for direct coal-firing in combustion gas turbines. This combustor island comprises a coal-fired pulse combustor, a combined ash agglomeration and sulfur capture chamber (CAASCC), and a hot cyclone. In the MTCI proprietary approach, the pulse combustion-induced high intensity sound waves improve sulfur capture efficiency and ash agglomeration. The resulting agglomerates allow the use of commercial cyclones and achieve very high particulate collection efficiency. In the MTCI proprietary approach, sorbent particles are injected into a gas stream subjected to an intense acoustic field. The acoustic field serves to improve sulfur capture efficiency by enhancing both gas film and intra-particle mass transfer rates. In addition, the sorbent particles act as dynamic filter foci, providing a high density of stagnant agglomerating centers for trapping the finer entrained (in the oscillating flow field) fly ash fractions. A team has been formed with MTCI as the prime contractor and Penn State University and West Virginia University as subcontractors to MTCI. MTCI is focusing on hardware development and system demonstration, PSU is investigating and modeling acoustic agglomeration and sulfur capture, and WVU is studying aerovalve fluid dynamics. Results are presented from all three studies.

  12. The Particulate Air Pollution Controversy

    PubMed Central

    Phalen, Robert F.

    2004-01-01

    Scientists, regulators, legislators, and segments of industry and the lay public are attempting to understand and respond to epidemiology findings of associations between measures of modern particulate air pollutants (PM) and adverse health outcomes in urban dwellers. The associations have been interpreted to imply that tens of thousands of Americans are killed annually by small daily increments in PM. These epidemiology studies and their interpretations have been challenged, although it is accepted that high concentrations of air pollutants have claimed many lives in the past. Although reproducible and statistically significant, the relative risks associated with modern PM are very small and confounded by many factors. Neither toxicology studies nor human clinical investigations have identified the components and/or characteristics of PM that might be causing the health-effect associations. Currently, a massive worldwide research effort is under way in an attempt to identify whom might be harmed and by what substances and mechanisms. Finding the answers is important, because control measures have the potential not only to be costly but also to limit the availability of goods and services that are important to public health. PMID:19330148

  13. SOUTHERN FINE PARTICULATE MONITORING PROJECT

    SciTech Connect

    Unknown

    2002-04-01

    This quarterly report presents results and analysis of continuous onsite ambient fine particulate data at the North Birmingham sampling site during the January-March, 2002 study period. The continuous data include PM{sub 2.5} mass concentrations measured by TEOM, particle sulfate using the R&P 8400S monitor, particle size distributions measured by SMPS and APS monitors, and PM{sub 2.5} light scattering extinction coefficient as measured by nephelometer. Some instrumental issues were noted with the upgrade of the APS model 3320 are described in the report, as well as preliminary performance indications for the upgraded instrument. During the quarter preliminary data analysis and modeling studies were conducted to test the potential of the North Birmingham site data for source attribution analyses. Our initial assessment has continued to be optimistic in this regard due to the location of the site relative to several important classes of local and midrange emission sources. We anticipate that these analyses will provide good separations of the effects of major source classes and spatial source clusters, and will provide useful information relevant to PM{sub 2.5} implementation strategies.

  14. New ESP additive controls particulates

    SciTech Connect

    Durham, M.D.; Baldrey, K.E.; Bustard, C.J.; Martin, C.E.; Dharmarajan, N.N.

    1997-06-01

    This article reports that a conditioning agent enhanced precipitator performance after plant switched to low-sulfur coal. Firing low-sulfur coal at a power plant designed for medium- or high-sulfur coal will impact the downstream particulate control device. Since the performance of an electro-static precipitator (ESP) is a strong function of the sulfur content in the coal, switching to a low-sulfur coal will severely impact collection efficiency. Particle resistivity is the dominant parameter affecting the performance of an ESP. When the resistivity is too high, the ESP must be increased in size by a factor of two to three, resulting in proportionally increased capital and operating costs. Fly ash from low-sulfur coal is known to have a typical resistivity one or two orders of magnitude above that for ideal collection efficiency in a well-designed ESP. Therefore, when a utility burning a medium- or high-sulfur coal switches to a low-sulfur coal, the increase in particle resistivity resulting from the reduced SO{sub 3} concentration will lead to severe problems in the ESP. There have been many instances where utilities have switched from a high- to a low-sulfur coal, and the problems caused by the increased resistivity have had such a devastating effect on the performance of the ESP that emissions have increased by a factor of 10.

  15. [Differences in soil respiration between cropland and grassland ecosystems and factors influencing soil respiration on the Loess Plateau].

    PubMed

    Zhou, Xiao-Gang; Zhang, Yan-Jun; Nan, Ya-Fang; Liu, Qing-Fang; Guo, Sheng-Li

    2013-03-01

    Understanding the effect of land-use change on soil respiration rates becomes critical in predicting soil carbon cycling under conversion of arable into grassland on the Loess Plateau. From July 2010 to December 2011, CO2 efflux from the soil surface was measured between 08:00 to 10:00 am in clear days by a Licor-8100 closed chamber system (Li-COR, Lincoln, NE, US). Also, soil temperature and soil moisture at the 5-cm depth was measured using a Li-Cor thermocouple and a hand-held frequency-domain reflectometer (ML2x, Delta-T Devices Ltd, UK) at each PVC collar, respectively. We found marked differences (P < 0.05) in soil respiration related to different land-use: the mean cropland soil respiration [1.35 micromol x (m2 x s)(-1)] was 24% (P < 0.05) less than the paired grassland soil respiration [1.67 micromol x (m2 x s)(-1)] (P < 0.05) during the period of experiment and the cumulative CO2-C emissions in grassland (856 g x m(-2)) was 23% (P < 0.05) higher than that in cropland (694 g x m(-2)). Soil moisture from 0-5 cm depth was much drier in cropland and significantly different between cropland and grassland except for winter. However, there were no clear relationships between soil moisture and soil respiration. Soil temperature at 5-cm depth was 2.5 degress C higher in grassland during the period of experiment (P < 0.05). Regression of soil temperature vs. soil respiration indicated significant exponential relationships both in grassland and cropland. Besides, there were intrinsic differences in response of soil respiration to temperature between the cropland and grassland ecosystems: grassland and cropland respiration response was significantly different at the alpha = 0.05 level, also expressed by a higher temperature sensitivity of soil respiration (Q10) in cropland (2.30) relative to grassland (1.74). Soil temperature of cropland and grassland can explain 79% of the variation in the soil respiration in grassland, compared to 82% in cropland. Therefore, land

  16. Particulate matter in the Venus atmosphere

    NASA Technical Reports Server (NTRS)

    Ragent, B.; Esposito, L. W.; Tomasko, M. G.; Marov, M. IA.; Shari, V. P.

    1985-01-01

    The paper presents a summary of the data currently available (June 1984) describing the planet-enshrouding particulate matter in the Venus atmosphere. A description and discussion of the state of knowledge of the Venus clouds and hazes precedes the tables and plots. The tabular material includes a precis of upper haze and cloud-top properties, parameters for model-size distributions for particles and particulate layers, and columnar masses and mass loadings.

  17. Establishing aeolian particulate 'fingerprints' in an airport environment using magnetic measurements and SEM/EDAX

    NASA Astrophysics Data System (ADS)

    Jones, Sue; Hoon, Stephen R.; Richardson, Nigel; Bennett, Michael

    2016-04-01

    The significant increase in global air travel which has occurred during the last fifty years has generated growing concern regarding the potential impacts associated with increasing emissions of particulate matter (PM) from aviation activity on health and the environment. PM within the airport environment, in particular, may be derived from a wide range of potential sources including aircraft; vehicles; ground support equipment and buildings. In order to investigate and remediate potential problem sources, it is important to be able to identify characteristic particulate 'fingerprints' which would allow source attribution, particularly respirable particulates. To date the identification of such 'fingerprints' has remained elusive but remains a key research priority for the aviation industry (Webb et al, 2008). In previous PM studies, environmental magnetism has been used as a successful technique for discriminating between different emission types and particulate sources in both urban and industrial environments (e.g. Hunt et al 1984; Lecoanet et al 2003, Jones et al 2015). Environmental magnetism is a non-destructive and relatively rapid technique involving the use of non-directional, rock magnetic measurements to characterise the mineral magnetic properties of natural and anthropogenic materials. In other studies scanning electron microscopy (SEM) has also been used as an effective characterisation technique for the investigation of grain size and morphology of PM derived from vehicle emissions (e.g. Bucko et al 2010) and fossil fuel combustion sources (Kim et al 2009). In this study, environmental magnetic measurements and SEM/EDAX have been used to characterise dusts from specific aircraft sources including engines, brakes and tyres. Furthermore, these methods have also been applied to runway (both hard and grass covered surfaces), taxiway and apron dusts collected during extensive environmental sampling at Manchester International Airport, UK in order to

  18. Respirable particles and carcinogens in the air of delaware hospitality venues before and after a smoking ban.

    PubMed

    Repace, James

    2004-09-01

    How do the concentrations of indoor air pollutants known to increase risk of respiratory disease, cancer, heart disease, and stroke change after a smoke-free workplace law? Real-time measurements were made of respirable particle (RSP) air pollution and particulate polycyclic aromatic hydrocarbons (PPAH), in a casino, six bars, and a pool hall before and after a smoking ban. Secondhand smoke contributed 90% to 95% of the RSP air pollution during smoking, and 85% to 95% of the carcinogenic PPAH, greatly exceeding levels of these contaminants encountered on major truck highways and polluted city streets. This air-quality survey demonstrates conclusively that the health of hospitality workers and patrons is endangered by tobacco smoke pollution. Smoke-free workplace laws eliminate that hazard and provide health protection impossible to achieve through ventilation or air cleaning.

  19. Response of pinon and juniper respiration to drought and warming

    NASA Astrophysics Data System (ADS)

    Collins, A.; McDowell, N. G.

    2013-12-01

    Drought and temperature-induced tree mortality is believed to be occurring globally, though the physiological mechanisms underlying documented mortality events are not well understood. Understanding the controls on forest carbon cycling and their responses during drought and temperature stress is critical in informing vegetation models and thus predictions of forest response to climate change. Pinon pine (Pinus edulis) and oneseed juniper (Juniperus monosperma) are widespread species in forests of the Southwestern United States and known to be susceptible to mortality due to altered precipitation and temperature regimes. Respiration is a key component of the carbon budget and its response to abiotic stress is thought to play a role in mortality or survival. The ability of these species to acclimate respiration to altered temperature and/or precipitation is a key model parameter, but is currently not known. A careful examination of the response of pinon and juniper respiration to increased temperature and drought conditions is thus a necessary step in predicting their future distribution in a changing environment. We established a rainfall and temperature manipulation experiment in a pinon-juniper woodland near Los Alamos, NM. In-situ trees were exposed to one of five treatments: warming alone, drought alone, warming plus drought, ambient control, and chamber control. Respiration measurements were conducted on the bole of each tree once per month between June and November 2012. A polycarbonate gas-exchange chamber was temporarily sealed to the bole of each tree during the night of each measurement cycle. Air was circulated from the chamber to a closed-path infra-red gas analyzer and CO2 flux was measured hourly. Preliminary analysis of results shows marked differences between the two species. Heated pinon showed elevated respiration and an unchanging Q10 of respiration while all other pinon treatments were no different from ambient control in either parameter

  20. Oxygen utilization rate (OUR) underestimates ocean respiration: A model study

    NASA Astrophysics Data System (ADS)

    Koeve, W.; Kähler, P.

    2016-08-01

    We use a simple 1-D model representing an isolated density surface in the ocean and 3-D global ocean biogeochemical models to evaluate the concept of computing the subsurface oceanic oxygen utilization rate (OUR) from the changes of apparent oxygen utilization (AOU) and water age. The distribution of AOU in the ocean is not only the imprint of respiration in the ocean's interior but is strongly influenced by transport processes and eventually loss at the ocean surface. Since AOU and water age are subject to advection and diffusive mixing, it is only when they are affected both in the same way that OUR represents the correct rate of oxygen consumption. This is the case only when advection prevails or with uniform respiration rates, when the proportions of AOU and age are not changed by transport. In experiments with the 1-D tube model, OUR underestimates respiration when maximum respiration rates occur near the outcrops of isopycnals and overestimates when maxima occur far from the outcrops. Given the distribution of respiration in the ocean, i.e., elevated rates near high-latitude outcrops of isopycnals and low rates below the oligotrophic gyres, underestimates are the rule. Integrating these effects globally in three coupled ocean biogeochemical and circulation models, we find that AOU-over-age based calculations underestimate true model respiration by a factor of 3. Most of this difference is observed in the upper 1000 m of the ocean with the discrepancies increasing toward the surface where OUR underestimates respiration by as much as factor of 4.

  1. Seasonality of temperate forest photosynthesis and daytime respiration

    NASA Astrophysics Data System (ADS)

    Wehr, R.; Munger, J. W.; McManus, J. B.; Nelson, D. D.; Zahniser, M. S.; Davidson, E. A.; Wofsy, S. C.; Saleska, S. R.

    2016-06-01

    Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is therefore crucial to predicting climate change. Yet there is no way of directly measuring the photosynthesis or daytime respiration of a whole ecosystem of interacting organisms; instead, these fluxes are generally inferred from measurements of net ecosystem-atmosphere CO2 exchange (NEE), in a way that is based on assumed ecosystem-scale responses to the environment. The consequent view of temperate deciduous forests (an important CO2 sink) is that, first, ecosystem respiration is greater during the day than at night; and second, ecosystem photosynthetic light-use efficiency peaks after leaf expansion in spring and then declines, presumably because of leaf ageing or water stress. This view has underlain the development of terrestrial biosphere models used in climate prediction and of remote sensing indices of global biosphere productivity. Here, we use new isotopic instrumentation to determine ecosystem photosynthesis and daytime respiration in a temperate deciduous forest over a three-year period. We find that ecosystem respiration is lower during the day than at night—the first robust evidence of the inhibition of leaf respiration by light at the ecosystem scale. Because they do not capture this effect, standard approaches overestimate ecosystem photosynthesis and daytime respiration in the first half of the growing season at our site, and inaccurately portray ecosystem photosynthetic light-use efficiency. These findings revise our understanding of forest-atmosphere carbon exchange, and provide a basis for investigating how leaf-level physiological dynamics manifest at the canopy scale in other ecosystems.

  2. Seasonality of temperate forest photosynthesis and daytime respiration.

    PubMed

    Wehr, R; Munger, J W; McManus, J B; Nelson, D D; Zahniser, M S; Davidson, E A; Wofsy, S C; Saleska, S R

    2016-06-30

    Terrestrial ecosystems currently offset one-quarter of anthropogenic carbon dioxide (CO2) emissions because of a slight imbalance between global terrestrial photosynthesis and respiration. Understanding what controls these two biological fluxes is therefore crucial to predicting climate change. Yet there is no way of directly measuring the photosynthesis or daytime respiration of a whole ecosystem of interacting organisms; instead, these fluxes are generally inferred from measurements of net ecosystem-atmosphere CO2 exchange (NEE), in a way that is based on assumed ecosystem-scale responses to the environment. The consequent view of temperate deciduous forests (an important CO2 sink) is that, first, ecosystem respiration is greater during the day than at night; and second, ecosystem photosynthetic light-use efficiency peaks after leaf expansion in spring and then declines, presumably because of leaf ageing or water stress. This view has underlain the development of terrestrial biosphere models used in climate prediction and of remote sensing indices of global biosphere productivity. Here, we use new isotopic instrumentation to determine ecosystem photosynthesis and daytime respiration in a temperate deciduous forest over a three-year period. We find that ecosystem respiration is lower during the day than at night-the first robust evidence of the inhibition of leaf respiration by light at the ecosystem scale. Because they do not capture this effect, standard approaches overestimate ecosystem photosynthesis and daytime respiration in the first half of the growing season at our site, and inaccurately portray ecosystem photosynthetic light-use efficiency. These findings revise our understanding of forest-atmosphere carbon exchange, and provide a basis for investigating how leaf-level physiological dynamics manifest at the canopy scale in other ecosystems.

  3. Impact of Land Use on Soil Respiration in Southwestern Victoria

    NASA Astrophysics Data System (ADS)

    Teodosio, B.; Daly, E.; Pauwels, V. R. N.

    2015-12-01

    Land use management is one of the key contributors to the global environmental change. Considerable changes in landscapes have been experienced in Southwestern Victoria, Australia in the past two decades. Eucalyptus globulus (blue gum) plantations have expanded, resulting in possible changes in the water and carbon balances of catchments. The shift from pastures to plantations could have a significant impact on the local carbon balance with possible effects on atmospheric CO2 concentration and vegetation productivity. We present preliminary measurements from a field study comparing soil respiration in a plantation and a pasture. Adjacent catchments in Southwestern Victoria, near Gatum, were used as study areas; the prominent difference between the two catchments is the land use, with one catchment being used as a pasture for livestock grazing and the other catchment being mainly planted with blue gums. The variability of soil respiration in the pasture is governed by differences in soil moisture and substrate content due to local features of the topography and livestock grazing. Soil respiration measurements in the plantation were taken on mounds, access tracks, and open spaces. Most observations on mounds had higher soil respiration possibly due to root and mycorrhizal respiration. The measurements in open spaces had comparable values with mound measurements; this might be due to a less limited radiation. The soil respiration between trees had lower values, possibly because of radiation limitation due to the canopy cover. These preliminary measurements allow us to compare soil respiration variability across catchments with different land uses. This is important to estimate CO2 fluxes from soil to the atmosphere in large areas and will be valuable in estimating gross primary production from measurements of net ecosystem exchange.

  4. Airborne Particulate Matter and Health Condition in Brick Kiln Workers in Kathmandu Valley, Nepal.

    PubMed

    Sanjel, S; Khanal, S N; Thygerson, S M; Khanal, K; Pun, Z; Tamang, S; Joshi, S K

    2016-01-01

    Background Air quality monitoring in brick kilns indicates very high concentrations of airborne particulate matter. Air pollution from brick kilns poses an enhanced threat to the environment and to human health. Objective To evaluate airborne particulate matter concentration and health status of brick kiln workers. Method A cross-sectional comparative study was conducted in the Kathmandu valley targeting all brick industries and their workers during January - March 2015 and March - April 2016. A total of 16 brick kilns and 800 participants (400 brick workers as exposed and 400 grocery workers as referent) were selected for study. A direct-reading, Dusttrak model 8533 was used for air sampling. Nepali version questionnaire was applied to obtain epidemiological data. SPSS version 16 was used to perform statistical analysis. Median, mean, range and proportion were calculated and Mann-Whitney U test, Kruskal-Wallis test and chi square (c2) test were applied to test significance. Result Mean values of particulate matter concentrations for brickfields were as follows: Total Suspended Particulate Matter (TSPM): 5.179 mg/m3, PM10: 4.958 mg/m3, respirable suspended particulate matter (RSPM): 4.140 mg/m3, PM2.5: 3.965 mg/m3, and PM1: 3.954 mg/m3. The mean concentrations for grocery workers were; TSPM: 0.089 mg/ m3, PM10: 0.089 mg/m3, RSPM: 0.085 mg/m3, PM2.5: 0.082 mg/m3 and PM1: 0.082 mg/m3. Among brickfield workers, red and green brick loading zones had results that exceeded the ACGIH Threshold Limit Values for TSPM and RSPM. Workers complaints of injury were 52% and 44.2%, and illnesses were 88.5% and 82.2%, respectively among exposed and referent. The occurrence of injuries/illnesses during work showed significant association between exposed and the referent groups at 0.05 level. Conclusion The high level of airborne particulate matter in the brick fields requires action for the protection of workers. The availability of health services within brick industries needs to

  5. Particulate emissions from construction activities.

    PubMed

    Muleski, Gregory E; Cowherd, Chatten; Kinsey, John S

    2005-06-01

    Although it has long been recognized that road and building construction activity constitutes an important source of particulate matter (PM) emissions throughout the United States, until recently only limited research has been directed to its characterization. This paper presents the results of PM10 and PM2.5 (particles < or = 10 microm and < or = 2.5 microm in aerodynamic diameter, respectively) emission factor development from the onsite testing of component operations at actual construction sites during the period 1998-2001. Much of the testing effort was directed at earthmoving operations with scrapers, because earthmoving is the most important contributor of PM emissions across the construction industry. Other sources tested were truck loading and dumping of crushed rock and mud and dirt carryout from construction site access points onto adjacent public paved roads. Also tested were the effects of watering for control of scraper travel routes and the use of paved and graveled aprons at construction site access points for reducing mud and dirt carryout. The PM10 emissions from earthmoving were found to be up to an order of magnitude greater than predicted by AP-42 emission factors drawn from other industries. As expected, the observed PM2.5:PM10 emission factor ratios reflected the relative importance of the vehicle exhaust and the resuspended dust components of each type of construction activity. An unexpected finding was that PM2.5 emissions from mud and dirt carryout were much less than anticipated. Finally, the control efficiency of watering of scraper travel routes was found to closely follow a bilinear moisture model.

  6. Small-angle light scattering by airborne particulates: Environnement S.A. continuous particulate monitor

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Thaury, Claire; Mineau, Jean-Luc; Gaubicher, Bertrand

    2010-08-01

    Airborne particulate matter may have an effect on human health. It is therefore necessary to determine and control in real time the evolution of the concentration and mass of particulates in the ambient air. These parameters can be obtained using optical methods. We propose here a new instrument, 'CPM' (continuous particulate monitor), for the measurement of light scattered by ambient particulates at small angles. This geometry allows simultaneous and separate detections of PM10, PM2.5 and PM1 fractions of airborne particulate matter, with no influence of their chemical nature and without using theoretical calculations. The ambient air is collected through a standard sampling head (PM10 inlet according to EN 12341, PM2.5 inlet according to EN 14907; or PM1, TSP inlets, standard US EPA inlets). The analysis of the first measurements demonstrates that this new instrument can detect, for each of the seven defined size ranges, real-time variations of particulate content in the ambient air. The measured concentrations (expressed in number per liter) can be converted into total mass concentrations (expressed in micrograms per cubic meter) of all fractions of airborne particulate matters sampled by the system. Periodic comparison with a beta-attenuation mass monitor (MP101M Beta Gauge Analyzer from Environnement S.A. company) allows the calculation of a calibration factor as a function of the mean particulate density that is used for this conversion. It is then possible to provide real-time relative variations of aerosol mass concentration.

  7. Advanced Hybrid Particulate Collector Project Management Plan

    SciTech Connect

    Miller, S.J.

    1995-11-01

    As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the best method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting

  8. Automatic respiration tracking for radiotherapy using optical 3D camera

    NASA Astrophysics Data System (ADS)

    Li, Tuotuo; Geng, Jason; Li, Shidong

    2013-03-01

    Rapid optical three-dimensional (O3D) imaging systems provide accurate digitized 3D surface data in real-time, with no patient contact nor radiation. The accurate 3D surface images offer crucial information in image-guided radiation therapy (IGRT) treatments for accurate patient repositioning and respiration management. However, applications of O3D imaging techniques to image-guided radiotherapy have been clinically challenged by body deformation, pathological and anatomical variations among individual patients, extremely high dimensionality of the 3D surface data, and irregular respiration motion. In existing clinical radiation therapy (RT) procedures target displacements are caused by (1) inter-fractional anatomy changes due to weight, swell, food/water intake; (2) intra-fractional variations from anatomy changes within any treatment session due to voluntary/involuntary physiologic processes (e.g. respiration, muscle relaxation); (3) patient setup misalignment in daily reposition due to user errors; and (4) changes of marker or positioning device, etc. Presently, viable solution is lacking for in-vivo tracking of target motion and anatomy changes during the beam-on time without exposing patient with additional ionized radiation or high magnet field. Current O3D-guided radiotherapy systems relay on selected points or areas in the 3D surface to track surface motion. The configuration of the marks or areas may change with time that makes it inconsistent in quantifying and interpreting the respiration patterns. To meet the challenge of performing real-time respiration tracking using O3D imaging technology in IGRT, we propose a new approach to automatic respiration motion analysis based on linear dimensionality reduction technique based on PCA (principle component analysis). Optical 3D image sequence is decomposed with principle component analysis into a limited number of independent (orthogonal) motion patterns (a low dimension eigen-space span by eigen-vectors). New

  9. Respirable Silica Dust Suppression During Artificial Stone Countertop Cutting

    PubMed Central

    Cooper, Jared H.; Johnson, David L.; Phillips, Margaret L.

    2015-01-01

    Purpose: To assess the relative efficacy of three types of controls in reducing respirable silica exposure during artificial stone countertop cutting with a handheld circular saw. Approach: A handheld worm drive circular saw equipped with a diamond segmented blade was fitted with water supply to wet the blade as is typical. The normal wetted-blade condition was compared to (i) wetted-blade plus ‘water curtain’ spray and (ii) wetted-blade plus local exhaust ventilation (LEV). Four replicate 30-min trials of 6-mm deep, 3-mm wide cuts in artificial quartz countertop stone were conducted at each condition in a 24-m3 unventilated tent. One dry cutting trial was also conducted for comparison. Respirable cyclone breathing zone samples were collected on the saw operator and analyzed gravimetrically for respirable mass and by X-ray diffraction for respirable quartz mass. Results: Mean quartz content of the respirable dust was 58.5%. The ranges of 30-min mass and quartz task concentrations in mg m−3 were as follows—wet blade alone: 3.54–7.51 and 1.87–4.85; wet blade + curtain: 1.81–5.97 and 0.92–3.41; and wet blade + LEV: 0.20–0.69 and <0.12–0.20. Dry cutting task concentrations were 69.6mg m−3 mass and 44.6mg m−3 quartz. There was a statistically significant difference (α = 0.05) between the wet blade + LEV and wet blade only conditions, but not between the wet blade + curtain and wet blade only conditions, for both respirable dust and respirable silica. Conclusions: Sawing with a wetted blade plus LEV reduced mean respirable dust and quartz task exposures by a factor of 10 compared to the wet blade only condition. We were unable to show a statistically significant benefit of a water curtain in the ejection path, but the data suggested some respirable dust suppression. PMID:25326187

  10. Determination of toxic material penetrations for wildland respirator filters

    SciTech Connect

    Foote, Kenneth Lawrence

    1994-05-01

    Thousands of wildland firefighters are exposed to high levels of toxic materials every year. Carbon monoxide, formaldehyde and acrolein gases, along with high particulate concentrations, are the major toxics encountered. Currently, the only respiratory protection wildland firefighters use is a bandanna over the mouth and nose. In this study, a modem activated carbon cartridge with an electrostatic prefilter was compared to a typical bandanna for its ability to filter wildland smoke toxics such as formaldehyde and particulates. The results of the tests were disappointing; neither filter performed very well. The activated carbon cartridge and prefilter efficiently collected formaldehyde gas for up to 60 minutes; however, it only collected 85 percent of the challenge particulate. ]Me bandanna, as expected, was only partially effective at collecting smoke particulate and filtered no toxic gases.

  11. Identification of Anaerobic Selenate-Respiring Bacteria from Aquatic Sediments▿

    PubMed Central

    Narasingarao, Priya; Häggblom, Max M.

    2007-01-01

    The diversity population of microorganisms with the capability to use selenate as a terminal electron acceptor, reducing it to selenite and elemental selenium by the process known as dissimilatory selenate reduction, is largely unknown. The overall objective of this study was to gain an in-depth understanding of anaerobic biotransformation of selenium in the environment, particularly anaerobic respiration, and to characterize the microorganisms catalyzing this process. Here, we demonstrate the isolation and characterization of four novel anaerobic dissimilatory selenate-respiring bacteria enriched from a variety of sources, including sediments from three different water bodies in Chennai, India, and a tidal estuary in New Jersey. Strains S5 and S7 from India, strain KM from the Meadowlands, NJ, and strain pn1, categorized as a laboratory contaminant, were all phylogenetically distinct, belonging to various phyla in the bacterial domain. The 16S rRNA gene sequence shows that strain S5 constitutes a new genus belonging to Chrysiogenetes, while strain S7 belongs to the Deferribacteres, with greater than 98% 16S rRNA gene similarity to Geovibrio ferrireducens. Strain KM is related to Malonomonas rubra, Pelobacter acidigallici, and Desulfuromusa spp., with 96 to 97% 16S rRNA gene similarity. Strain pn1 is 99% similar to Pseudomonas stutzeri. Strains S5, S7, and KM are obligately anaerobic selenate-respiring microorganisms, while strain pn1 is facultatively anaerobic. Besides respiring selenate, all these strains also respire nitrate. PMID:17435005

  12. Cannabinoid-induced changes in respiration of brain mitochondria.

    PubMed

    Fišar, Zdeněk; Singh, Namrata; Hroudová, Jana

    2014-11-18

    Cannabinoids exert various biological effects that are either receptor-mediated or independent of receptor signaling. Mitochondrial effects of cannabinoids were interpreted either as non-receptor-mediated alteration of mitochondrial membranes, or as indirect consequences of activation of plasma membrane type 1 cannabinoid receptors (CB1). Recently, CB1 receptors were confirmed to be localized to the membranes of neuronal mitochondria, where their activation directly regulates respiration and energy production. Here, we performed in-depth analysis of cannabinoid-induced changes of mitochondrial respiration using both an antagonist/inverse agonist of CB1 receptors, AM251 and the cannabinoid receptor agonists, Δ(9)-tetrahydrocannabinol (THC), cannabidiol, anandamide, and WIN 55,212-2. Relationships were determined between cannabinoid concentration and respiratory rate driven by substrates of complex I, II or IV in pig brain mitochondria. Either full or partial inhibition of respiratory rate was found for the tested drugs, with an IC50 in the micromolar range, which verified the significant role of non-receptor-mediated mechanism in inhibiting mitochondrial respiration. Effect of stepwise application of THC and AM251 evidenced protective role of AM251 and corroborated the participation of CB1 receptor activation in the inhibition of mitochondrial respiration. We proposed a model, which includes both receptor- and non-receptor-mediated mechanisms of cannabinoid action on mitochondrial respiration. This model explains both the inhibitory effect of cannabinoids and the protective effect of the CB1 receptor inverse agonist.

  13. Breathing simulator of workers for respirator performance test.

    PubMed

    Yuasa, Hisashi; Kumita, Mikio; Honda, Takeshi; Kimura, Kazushi; Nozaki, Kosuke; Emi, Hitoshi; Otani, Yoshio

    2015-01-01

    Breathing machines are widely used to evaluate respirator performance but they are capable of generating only limited air flow patterns, such as, sine, triangular and square waves. In order to evaluate the respirator performance in practical use, it is desirable to test the respirator using the actual breathing patterns of wearers. However, it has been a difficult task for a breathing machine to generate such complicated flow patterns, since the human respiratory volume changes depending on the human activities and workload. In this study, we have developed an electromechanical breathing simulator and a respiration sampling device to record and reproduce worker's respiration. It is capable of generating various flow patterns by inputting breathing pattern signals recorded by a computer, as well as the fixed air flow patterns. The device is equipped with a self-control program to compensate the difference in inhalation and exhalation volume and the measurement errors on the breathing flow rate. The system was successfully applied to record the breathing patterns of workers engaging in welding and reproduced the breathing patterns.

  14. Isotopic Forced-Diffusion Technique for Soil Respiration Pathway Studies

    NASA Astrophysics Data System (ADS)

    Nickerson, Nick; Egan, Jocelyn; Risk, David; McArthur, Gordon; Cunningham, Kevin; Jacobson, Gloria; Saad, Nabil; Panetta, Robert

    2013-04-01

    Isotopic ratio measurements of soil-respired CO2 can provide a wealth of insight into soil-level carbon-cycle processes that is not available using bulk CO2 emissions measurements alone. Soil contains substantial amounts of carbon, and can contribute CO2to the atmosphere through various respiration pathways. Isotopic analysis can distinguish autotrophic root and rhizosphere respiration from heterotrophic respiration due to the catabolism of soil organic matter (SOM). Because of this, researchers have shifted their efforts toward the use of natural abundance and tracer isotopic techniques in ecosystem respiration studies. However, recent experimental and theoretical evidence indicates that these traditional techniques yield biased estimates of the soil isotopic flux, largely owing to disturbances to the soil's natural diffusive regime. To help eliminate theses biases, we have developed a new technique called Isotopic Forced-Diffusion (IsoFD). The Isotopic Forced-Diffusion technique integrates a Forced Diffusion dynamic chamber with a cavity ringdown spectrometer measuring δ13C-CO2, which are operated together as a closed, recycling system where the leakage and pressures through the system are properly managed. The system produces real-time, high temporal resolution isotopic soil efflux data. We will present the theory behind this technique and present preliminary laboratory and field data.

  15. Isotopic Forced-Diffusion Technique for Soil Respiration Studies

    NASA Astrophysics Data System (ADS)

    McArthur, G.; Nickerson, N. R.; Egan, J.; Risk, D. A.; Jacobson, G. A.; Cunningham, K. L.; Saad, N.

    2013-12-01

    Isotopic ratio measurements of soil-respired CO2 can provide a wealth of insight into soil-level carbon-cycle processes that is not available using bulk CO2 emission measurements alone. Soil contains substantial amounts of carbon, and can contribute CO2 to the atmosphere through various respiration pathways. Isotopic analysis can distinguish autotrophic root and rhizosphere respiration from heterotrophic respiration due to the catabolism of soil organic matter (SOM). Because of this, researchers have shifted their efforts toward the use of natural abundance and tracer isotopic techniques in ecosystem respiration studies. However, recent experimental and theoretical evidence indicates that these traditional techniques yield biased estimates of the soil isotopic flux, largely owing to disturbances to the soil's natural diffusive regime. To help eliminate these biases, we have developed a new technique called Isotopic Forced-Diffusion (IsoFD). The Isotopic Forced-Diffusion technique integrates a Forced Diffusion dynamic chamber with a cavity ringdown spectrometer measuring d13C-CO2, which are operated together as an integrated system. The system produces real-time, high temporal resolution isotopic soil efflux data. Here, we will present the theory behind this technique, present laboratory data demonstrating the accuracy and precision of the technique in controlled environments and finally field data from two campaigns, showing the ability of the Iso-FD chamber to detect natural diurnal changes in isotopic signature as well as differentiate sources in C3-C4 transitional systems.

  16. Assessment of respiration activity and ecotoxicity of composts containing biopolymers.

    PubMed

    Kopeć, Michał; Gondek, Krzysztof; Baran, Agnieszka

    2013-03-01

    The research was conducted to determine if introducing biodegradable polymer materials to the composting process would affect selected biological properties of mature compost. Determination of biological properties of composts composed of testing their respiration activity and toxicity. Respiration activity was measured in material from the composting process by means of OxiTop Control measuring system. The ecotoxicity of composts was estimated by means of a set of biotests composed of three microbiotests using five test organisms. Introduction of polymer materials caused a decrease in respiration activity of mature compost. Similar dependencies as in the case of mass loss were registered. Compost to which a biodegradable polymer with the highest content of starch was added revealed the smallest difference in comparison with organic material composted without polymers. Lower content of starch in a polymer caused lower respiration activity of composts, whereas microorganism vaccine might have accelerated maturing of composts, thus contributing to the smallest respiration of compost. In composts containing biopolymers the following were observed: an increase in germination inhibition--2.5 times, roots growth inhibition--1.8 times, growth inhibition of Heterocypris incongruens--four times and luminescence inhibition of Vibrio fischeri--1.6 times in comparison with the control (compost K1). Composts containing biopolymers were classified as toxicity class III, whereas the compost without polymer addition as class II.

  17. Respirable quartz exposure at silica flour producers, 1975-1986

    SciTech Connect

    Not Available

    1988-10-01

    A study was conducted on respirable quartz exposures at silica flour producers for the period 1975-1986. In 1979, evaluations were performed at two silica-flour facilities in Illinois for the purpose of determining worker exposure to respirable quartz. It was evident that workers at both sites had a high incidence of silicosis. Continuing with the effort, visits were made to 28 silica-flour producers between 1975 and 1986. A total of 2,175 respirable quartz samples were examined and 52% of these exceeded the Mining Safety and Health Act (MSHA) Permissible Exposure Level (PEL). In 1984, 1985, and 1986, the percentages of samples taken which exceeded the PEL were 44, 46, and 34, respectively. The Recommended Exposure Level (REL) as established in NIOSH for pure respirable quartz limits exposure to a 10-hour time-weighted average level of 0.05mg/m{sup 3}. The percentage of samples of respirable quartz which exceeded this REL for the same time period were 74, 76, and 69, respectively. According to the authors, while the figures since 1979 do show the exposures to be dropping, there were still far more overexposures in this industry than in most other metal and nonmetal commodities. Without greater efforts to meet the levels required, the new cases of silicosis will continue to occur among workers in this industry.

  18. NIOSH (National Institute for Occupational Safety and Health) certified equipment list as of October 1, 1987

    SciTech Connect

    Not Available

    1987-10-01

    Commercial personal protective devices and industrial-hazard measuring instruments certified by NIOSH as of October 1, 1986, were listed. The publication also contained information about the certified coal-mine-dust personal sampler units and respirators, updated the list of approval applications, and listed some of the more common cautions and limitations for specific respirator classes. Certification information was provided for self-contained breathing apparatus for entry into and escape and for escape only situations; for gas masks useful against ammonia, chlorine, sulfur dioxide, acid gases, organic vapors, carbon monoxide, pesticides and other gases and vapors; for various types of supplied air respirators; for particulate respirators involved in single use situations, dusts and mists, fumes, and high efficiency types; for chemical cartridges effective against ammonia, methylamines, chlorine, hydrogen chloride, sulfur dioxide, organic vapor, paints, lacquers, enamels, pesticides, vinyl chloride, and other gases and vapors; and powered air purifiers. The names and addresses of manufacturers and distributors were provided.

  19. Estimating daytime ecosystem respiration to improve estimates of gross primary production of a temperate forest.

    PubMed

    Sun, Jinwei; Wu, Jiabing; Guan, Dexin; Yao, Fuqi; Yuan, Fenghui; Wang, Anzhi; Jin, Changjie

    2014-01-01

    Leaf respiration is an important component of carbon exchange in terrestrial ecosystems, and estimates of leaf respiration directly affect the accuracy of ecosystem carbon budgets. Leaf respiration is inhibited by light; therefore, gross primary production (GPP) will be overestimated if the reduction in leaf respiration by light is ignored. However, few studies have quantified GPP overestimation with respect to the degree of light inhibition in forest ecosystems. To determine the effect of light inhibition of leaf respiration on GPP estimation, we assessed the variation in leaf respiration of seedlings of the dominant tree species in an old mixed temperate forest with different photosynthetically active radiation levels using the Laisk method. Canopy respiration was estimated by combining the effect of light inhibition on leaf respiration of these species with within-canopy radiation. Leaf respiration decreased exponentially with an increase in light intensity. Canopy respiration and GPP were overestimated by approximately 20.4% and 4.6%, respectively, when leaf respiration reduction in light was ignored compared with the values obtained when light inhibition of leaf respiration was considered. This study indicates that accurate estimates of daytime ecosystem respiration are needed for the accurate evaluation of carbon budgets in temperate forests. In addition, this study provides a valuable approach to accurately estimate GPP by considering leaf respiration reduction in light in other ecosystems.

  20. Growth and respiration of regenerating tissues of the axolotl tail.

    PubMed

    Vladimirova, I G

    1975-01-01

    Changes in the weight and oxygen consumption were studied during regeneration of the tail in adult axolotls and larvae. The curve of the increase in weight of the regenerating tail in both age groups is S-shaped. The intensity of respiration of the regenerating tail increases in adult axolotls and in larvae at the blastema stage; in adult axolotls there is also a second increase in the intensity of respiration of the regenerating tail during differentiation of the muscles. The relationship between weight and the rate of respiration was compared during regeneration of the tail in axolotl and the normal growth of the animals. Whereas growth of the animals was characterized by the relationship QO2 equals aPk with a constant value of k, during regeneration the various stages of this process have their own corresponding values of k.