Investigation of a systematic offset in the measurement of organic carbon with a semicontinuous analyzer.

PubMed

Offenberg, John H; Lewandowski, Michael; Edney, Edward O; Kleindienst, Tadeusz E; Jaoui, Mohammed

2007-05-01

Organic carbon (OC) was measured semicontinuously in laboratory experiments of steady-state secondary organic aerosol formed by hydrocarbon + nitrogen oxide irradiations. Examination of the mass of carbon measured on the filter for various sample volumes reveals a systematic offset that is not observed when performing an instrumental blank. These findings suggest that simple subtraction of instrumental blanks determined as the standard analysis without sample collection (i.e., by cycling the pump and valves yet filtering zero liters of air followed by routine chemical analysis) from measured concentrations may be inadequate. This may be especially true for samples collected through the filtration of small air volumes wherein the influence of the systematic offset is greatest. All of the experiments show that filtering a larger volume of air minimizes the influence of contributions from the systematic offset. Application of these results to measurements of ambient concentrations of carbonaceous aerosol suggests a need for collection of sufficient carbon mass to minimize the relative influence of the offset signal.

Atmospheric CO2 Records from Sites in the Main Geophysical Observatory Air Sampling Network (1983 - 1993)

DOE Data Explorer

Brounshtein, A. M. [Main Geophysical Observatory, St. Petersburg, Russia; Shaskov, A. A. [Main Geophysical Observatory, St. Petersburg, Russia; Paramonova, N. N. [Main Geophysical Observatory, St. Petersburg, Russia; Privalov, V. I. [Main Geophysical Observatory, St. Petersburg, Russia; Starodubtsev, Y. A. [Main Geophysical Observatory, St. Petersburg, Russia

1997-01-01

Air samples were collected from five sites in the Main Geophysical Observatory air sampling network to monitor the atmospheric CO2 from 1983 - 1993. Airwas collected generally four times per month in pairs of 1.5-L stainless steel electropolished flasks with one greaseless stainless steel stopcock. Sampling was performed by opening the stopcock of the flasks, which have been evacuated at the central laboratory at the Main Geophysical Observatory (MGO). The air was not dried during sample collection. Attempts were made to obtain samples when the wind speed was >5 m/s and the wind direction corresponded to the predetermined "clean air" sector. The period of record at Bering Island is too short to identify any long-term trends in atmospheric CO2 concentrations; however, the yearly mean atmospheric CO2 concentration at Bering Island rose from approximately 346 parts per million by volume (ppmv) in 1986 to 362.6 ppmv in 1993. Measurements from this station are considered indicative of maritime air masses. The period of record at Kotelny Island is too short to identify any long-term trends in atmospheric CO2 concentrations; however, the yearly mean atmospheric CO2 concentration at Kotelny Island rose from 356.08 parts per million by volume (ppmv) in 1988 to 358.8 ppmv in 1993. Because Kotelny Island is the northernmost Russian sampling site, measurements from this site serve as a useful comparison to other northern sites (e.g., Alert, Northwest Territories). In late 1989, air sampling began at the Russian site of Kyzylcha, located in the Republic of Uzbekistan. Unfortunately, the desert site at Kyzylcha has been out of operation since mid-1991 due to financial difficulties in Russia. The annual mean value of 359.02 parts per million by volume (ppmv) for 1990, the lone full year of operation, is higher than measurements from other monitoring programs at this latitude [e.g., Niwot Ridge (354.7 ppmv in 1990) and Tae-ahn Peninsula]. Station "C," an open ocean site, in the North Atlantic, east of Greenland, was established in 1968 and was operated in cooperation with NOAA's National Weather Service through 1973. The Main Geophysical Observatory collected flask samples at the site from January 1983 through October 1990. The yearly mean atmospheric CO concentration at Station "C" rose from 348.15 parts per million by volume (ppmv) in 1985 to 354.33 ppmv in 1989. The period of record at Teriberka Station is too short to identify any long-term trends in atmospheric CO2 concentrations; however, the yearly mean atmospheric CO2 concentration at Teriberka Station rose from 354.8 parts per million by volume (ppmv) in 1989 to 358.7 ppmv in 1993.

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Volume II of the Site Environmental Report for 2006 is provided by Ernest Orlando Lawrence Berkeley National Laboratory as a supplemental appendix to Volume I, which contains the body of the report. Volume II contains the environmental monitoring and sampling data used to generate summary results of routine and nonroutine activities at the Laboratory (except for groundwater sampling data, which may be found in the reports referred to in Chapter 4). Volume I summarizes the results from analyses of the data. The results from sample collections are more comprehensive in Volume II than in Volume I: For completeness, all resultsmore » from sample collections that began or ended in calendar year (CY) 2006 are included in this volume. However, the samples representing CY 2005 data have not been used in the summary results that are reported in Volume I. (For example, although ambient air samples collected on January 2, 2006, are presented in Volume II, they represent December 2005 data and are not included in Table 4-2 in Volume I.)« less

Development and testing of a portable wind sensitive directional air sampler

NASA Technical Reports Server (NTRS)

Deyo, J.; Toma, J.; King, R. B.

1975-01-01

A portable wind sensitive directional air sampler was developed as part of an air pollution source identification system. The system is designed to identify sources of air pollution based on the directional collection of field air samples and their analysis for TSP and trace element characteristics. Sources can be identified by analyzing the data on the basis of pattern recognition concepts. The unit, designated Air Scout, receives wind direction signals from an associated wind vane. Air samples are collected on filter slides using a standard high volume air sampler drawing air through a porting arrangement which tracks the wind direction and permits collection of discrete samples. A preset timer controls the length of time each filter is in the sampling position. At the conclusion of the sampling period a new filter is automatically moved into sampling position displacing the previous filter to a storage compartment. Thus the Air Scout may be set up at a field location, loaded with up to 12 filter slides, and left to acquire air samples automatically, according to the wind, at any timer interval desired from 1 to 30 hours.

Determination of formaldehyde by HPLC as the DNPH derivative following high-volume air sampling onto bisulfite-coated cellulose filters

NASA Astrophysics Data System (ADS)

de Andrade, Jailson B.; Tanner, Roger L.

A method is described for the specific collection of formaldehyde as hydroxymethanesulfonate on bisulfate-coated cellulose filters. Following extraction in aqueous acid and removal on unreacted bisulfite, the hydroxymethanesulfonate is decomposed by base, and HCHO is determined by DNPH (2,4-dinitrophenylhydrazine) derivatization and HPLC. Since the collection efficiency for formaldehyde is moderately high even when sampling ambient air at high-volume flow rates, a limit of detection of 0.2 ppbv is achieved with 30 min sampling times. Interference from acetaldehyde co-collected as 1-hydroxyethanesulfonate is <5% using this procedure. The technique shows promise for both short-term airborne sampling, and as a means of collecting mg-sized samples of HCHO on an inorganic matrix for carbon isotopic analyses.

[Determination of short-chain chlorinated paraffins in ambient air using high-volume sampling combined with high resolutimi gas chromatography-electron capture negative ion-low resolution mass spectrometry].

PubMed

Shi, Loimeng; Gao, Yuan; Hou, Xiaohong; Zhang, Haijun; Zhang, Yichi; Chen, Jiping

2016-02-01

An analytical method for quantifying short-chain chlorinated paraffins (SCCPs) in ambient air using high-volume sampling combined with high resolution gas chromatography-electron capture negative ion-low resolution mass spectrometry ( HRGC-ECNI-LRMS) was developed. An acidified silica gel column and a basic alumina column were used to optimize the cleanup procedures. The results showed a good linearity (R2>0. 99) between the total response factors and the degree of chlorination of SCCPs in the content range of 58. 1%-63. 3%. The limits of detection (S/N ≥3) and the limits of quantification (S/N ≥ 10) were 4. 2 and 12 µg, respectively. The method detection limit (MDL) for SCCPs was 0. 34 ng/m3 (n = 7). The recoveries of SCCPs in air samples were in the range of 81. 9% to 94. 2%. It is demonstrated that the method is suitable for the quantitative analysis of SCCPs in air samples.

Aircraft data summaries for the SURE intensives. Final report. [Sampling done July 1978 near Duncan Falls, Ohio and Scranton, Pennsylvania

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keifer, W.S.; Blumenthal, D.L.; Tommerdahl, J.B.

1981-09-01

As part of the EPRI sulfate regional experiment (SURE), Meteorology Research, Inc., (MRI) and Research Triangle Institute (RTI) conducted six air quality sampling programs in the eastern United States using instrumented aircraft. This volume includes the air quality and meteorological data obtained during the July 1978 Intensive when MRI sampled near the Duncan Falls, Ohio, SURE Station and RTI sampled near the Scranton, Pennsylvania, SURE Station. During the last part of the July 1978 sampling period, both MRI and RTI aircraft participated in a large regional-scale sampling program with Brookhaven National Laboratory (BNL) and Pacific Northwest Laboratory (PNL). Only themore » data obtained by the MRI and RTI aircraft during this regional-scale sapling program are included in this volume.« less

Recent Advances in Water Analysis with Gas Chromatograph Mass Spectrometers

NASA Technical Reports Server (NTRS)

MacAskill, John A.; Tsikata, Edem

2014-01-01

We report on progress made in developing a water sampling system for detection and analysis of volatile organic compounds in water with a gas chromatograph mass spectrometer (GCMS). Two approaches are described herein. The first approach uses a custom water pre-concentrator for performing trap and purge of VOCs from water. The second approach uses a custom micro-volume, split-splitless injector that is compatible with air and water. These water sampling systems will enable a single GC-based instrument to analyze air and water samples for VOC content. As reduced mass, volume, and power is crucial for long-duration, manned space-exploration, these water sampling systems will demonstrate the ability of a GCMS to monitor both air and water quality of the astronaut environment, thereby reducing the amount of required instrumentation for long duration habitation. Laboratory prototypes of these water sampling systems have been constructed and tested with a quadrupole ion trap mass spectrometer as well as a thermal conductivity detector. Presented herein are details of these water sampling system with preliminary test results.

Environmental assessment of a crude-oil heater using staged air lances for NOx reduction. Volume 1. Technical results. Final report June 1981-November 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeRosier, R.

1984-07-01

This volume of the report gives emission results from field tests of a crude-oil process heater burning a combination of oil and refinery gas. The heater had been modified by adding a system for injecting secondary air to reduce NOx emissions. One test was conducted with the staged air system (low NOx), and the other, without (baseline). Tests included continuous monitoring of flue gas emissions and source assessment sampling system (SASS) sampling of the flue gas with subsequent laboratory analysis of the samples utilizing gas chromatography (GC), infrared spectrometry (IR), gas chromatography/mass spectroscopy (GC/MS), and low resolution mass spectrometry (SSMS)more » for trace metals. LRMS analysis suggested the presence of eight compound categories in the organic emissions during the baseline test and four in the low-NOx test.« less

Microfluidics-based integrated airborne pathogen detection systems

NASA Astrophysics Data System (ADS)

Northrup, M. Allen; Alleman-Sposito, Jennifer; Austin, Todd; Devitt, Amy; Fong, Donna; Lin, Phil; Nakao, Brian; Pourahmadi, Farzad; Vinas, Mary; Yuan, Bob

2006-09-01

Microfluidic Systems is focused on building microfluidic platforms that interface front-end mesofluidics to handle real world sample volumes for optimal sensitivity coupled to microfluidic circuitry to process small liquid volumes for complex reagent metering, mixing, and biochemical analysis, particularly for pathogens. MFSI is the prime contractor on two programs for the US Department of Homeland Security: BAND (Bioagent Autonomous Networked Detector) and IBADS (Instantaneous Bio-Aerosol Detection System). The goal of BAND is to develop an autonomous system for monitoring the air for known biological agents. This consists of air collection, sample lysis, sample purification, detection of DNA, RNA, and toxins, and a networked interface to report the results. For IBADS, MFSI is developing the confirmatory device which must verify the presence of a pathogen with 5 minutes of an air collector/trigger sounding an alarm. Instrument designs and biological assay results from both BAND and IBADS will be presented.

Refinements of environmental assessment during an outbreak investigation of invasive aspergillosis in a leukemia and bone marrow transplant unit.

PubMed

Thio, C L; Smith, D; Merz, W G; Streifel, A J; Bova, G; Gay, L; Miller, C B; Perl, T M

2000-01-01

To investigate an outbreak of aspergillosis in a leukemia and bone marrow transplant (BMT) unit and to improve environmental assessment strategies to detect Aspergillus. Epidemiological investigation and detailed environmental assessment. A tertiary-care university hospital with a 37-bed leukemia and BMT unit Leukemic or BMT patients with invasive aspergillosis identified through prospective surveillance and confirmed by chart review. We verified the diagnosis of invasive fungal infection by reviewing medical charts of at-risk patients, performing a case-control study to determine risk factors for infection, instituting wet mopping to clean all floors, providing N95 masks to protect patients outside high-efficiency particulate air (HEPA)-filtered areas, altering traffic patterns into the unit, and performing molecular typing of selected Aspergillus flavus isolates. To assess the environment, we verified pressure relationships between the rooms and hallway and between buildings, and we compared the ability of large-volume (1,200 L) and small-volume (160 L) air samplers to detect Aspergillus spores. Of 29 potential invasive aspergillosis cases, 21 were confirmed by medical chart review. Risk factors for developing invasive aspergillosis included the length of time since malignancy was diagnosed (odds ratio [OR], 1.0; P=.05) and hospitalization in a patient room located near a stairwell door (OR, 3.7; P=.05). Two of five A. flavus patient isolates were identical to one of the environmental isolates. The pressure in most of the rooms was higher than in the corridors, but the pressure in the oncology unit was negative with respect to the physically adjacent hospital; consequently, the unit acted essentially as a vacuum that siphoned non-HEPA-filtered air from the main hospital. Of the 78 samples obtained with a small-volume air sampler, none grew an Aspergillus species, whereas 10 of 40 cultures obtained with a large-volume air sampler did. During active construction, Aspergillus spores may have entered the oncology unit from the physically adjacent hospital because the air pressure differed. Guidelines that establish the minimum acceptable pressures and specify which pressure relationships to test in healthcare settings are needed. Our data show that large-volume air samples are superior to small-volume samples to assess for Aspergillus in the healthcare environment.

40 CFR 86.521-90 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... apparatus. The methanol is vaporized and swept into the sample bag with a known volume of zero grade air....521-90 Section 86.521-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and basic operating adjustment using the appropriate FID fuel and zero-grade air. (2) Optimize on the...

40 CFR 86.1221-90 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... apparatus. The methanol is vaporized and swept into the sample bag with a known volume of zero grade air....1221-90 Section 86.1221-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... appropriate FID fuel and zero-grade air. (2) Optimize on the most common operating range. Introduce into the...

40 CFR 86.521-90 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apparatus. The methanol is vaporized and swept into the sample bag with a known volume of zero grade air....521-90 Section 86.521-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... and basic operating adjustment using the appropriate FID fuel and zero-grade air. (2) Optimize on the...

40 CFR 86.121-90 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... sample bag with a known volume of zero grade air measured by a gas flow meter meeting the performance....121-90 Section 86.121-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... operating adjustment using the appropriate FID fuel and zero-grade air. (2) Optimize on the most common...

40 CFR 86.121-90 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... sample bag with a known volume of zero grade air measured by a gas flow meter meeting the performance....121-90 Section 86.121-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... operating adjustment using the appropriate FID fuel and zero-grade air. (2) Optimize on the most common...

40 CFR 86.1221-90 - Hydrocarbon analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apparatus. The methanol is vaporized and swept into the sample bag with a known volume of zero grade air....1221-90 Section 86.1221-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR... appropriate FID fuel and zero-grade air. (2) Optimize on the most common operating range. Introduce into the...

Aircraft data summaries for the SURE intensives. Final report. [Sampling done August 1977 near Rockport, Indiana and Duncan Falls, Ohio

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blumenthal, D.L.; Tommerdahl, J.B.; McDonald, J.A.

1981-09-01

As part of the EPRI sulfate regional experiment (SURE), Meteorology Research, Inc., (MRI) and Research Triangle Institute (RTI) conducted six air quality sampling programs in the eastern United States using instrumented aircraft. This volume includes the air quality and meteorological data obtained during the August 1977 Intensive when MRI sampled near the Rockport, Indiana, SURE Station and RTI sampled near the Duncan Falls, Ohio, SURE Station. Sampling data are presented for all measured parameters.

Treatability Study in Support of Intrinsic Remediation for Site OT 24 at MacDill Air Force Base, Florida. Volume 2

DTIC Science & Technology

1997-01-01

Not Sampled f PJ)ll PARSONS SAA - Some As Above Y Water level drilled LF-JENGINEERING SCIENCE.INC. Denver, Colorado L:\\45021\\,DRAWINGS\\BORELOGS\\OT-24...Remnediotion TS TOC - Top of Cosing G - GRAB MacDill Air Force Base, Florida NS- Not Sampled .PARUONU SAA - Same As Above VWater level drilled L!LJ...GRAB MacDill Air Force Base. Florida NS - Not Sampled fj•--PAMMMNuI SAA - Some As Above Y Water level drilled *NIIN I N Denver. Colorado L:\\45021

Double-layer Tedlar bags: a means to limit humidity evolution of air samples and to dry humid air samples.

PubMed

Cariou, Stephane; Guillot, Jean-Michel

2006-01-01

Tedlar bags, which are widely used to collect air samples, especially VOCs and odorous atmospheres, can allow humidity to diffuse when relative humidity levels differ between the inside and outside. Starting with dry air inside the bag and humid air outside, we monitored equilibrium times under several conditions showing the evolution and influence of collected volumes and exposed surfaces. A double-film Tedlar bag was made, to limit the impact of external humidity on a sample at low humidity level. With the addition of a drying agent between both films, the evolution of humidity of a sample can be stopped for several hours. When a VOC mixture was monitored in a humid atmosphere, humidity was decreased but no significant evolution of VOC concentrations was observed.

SU-E-I-79: Source Geometry Dependence of Gamma Well-Counter Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, M; Belanger, A; Kijewski, M

Purpose: To determine the effect of liquid sample volume and geometry on counting efficiency in a gamma well-counter, and to assess the relative contributions of sample geometry and self-attenuation. Gamma wellcounters are standard equipment in clinical and preclinical studies, for measuring patient blood radioactivity and quantifying animal tissue uptake for tracer development and other purposes. Accurate measurements are crucial. Methods: Count rates were measured for aqueous solutions of 99m- Tc at four liquid volume values in a 1-cm-diam tube and at six volume values in a 2.2-cm-diam vial. Total activity was constant for all volumes, and data were corrected formore » decay. Count rates from a point source in air, supported by a filter paper, were measured at seven heights between 1.3 and 5.7 cm from the bottom of a tube. Results: Sample volume effects were larger for the tube than for the vial. For the tube, count efficiency relative to a 1-cc volume ranged from 1.05 at 0.05 cc to 0.84 at 3 cc. For the vial, relative count efficiency ranged from 1.02 at 0.05 cc to 0.87 at 15 cc. For the point source, count efficiency relative to 1.3 cm from the tube bottom ranged from 0.98 at 1.8 cm to 0.34 at 5.7 cm. The relative efficiency of a 3-cc liquid sample in a tube compared to a 1-cc sample is 0.84; the average relative efficiency for the solid sample in air between heights in the tube corresponding to the surfaces of those volumes (1.3 and 4.8 cm) is 0.81, implying that the major contribution to efficiency loss is geometry, rather than attenuation. Conclusion: Volume-dependent correction factors should be used for accurate quantitation radioactive of liquid samples. Solid samples should be positioned at the bottom of the tube for maximum count efficiency.« less

Air Sampling Filter

NASA Technical Reports Server (NTRS)

1980-01-01

General Metal Works' Accu-Vol is a high-volume air sampling system used by many government agencies to monitor air quality for pollution control purposes. Procedure prevents possible test-invalidating contamination from materials other than particulate pollutants, caused by manual handling or penetration of windblown matter during transit, a cassette was developed in which the filter is sealed within a metal frame and protected in transit by a snap-on aluminum cover, thus handled only under clean conditions in the laboratory.

Carbon and oxygen isotope ratios of ecosystem respiration along an Oregon conifer transect: preliminary observations based on small-flask sampling.

PubMed

Ehleringer, J. R.; Cook, C. S.

1998-01-01

Isotope ratio analyses of atmospheric CO(2) at natural abundance have significant potential for contributing to our understanding of photosynthetic and respiration processes in forest ecosystems. Recent advances in isotope ratio mass spectrometry allow for rapid, on-line analysis of small volumes of CO(2) in air, and open new research opportunities at the ecophysiological, whole-organism, and atmospheric levels. Among the immediate applications are the carbon and oxygen isotope ratio analyses of carbon dioxide in atmospheric air. Routine analysis of carbon dioxide in air volumes of approximately 50-300 &mgr;l is accomplished by linking a commercially available, trace gas condenser and gas chromatograph to an isotope ratio mass spectrometer operated in continuous-flow mode. Samples collected in the field are stored in either gas-tight syringes or 100-ml flasks. The small sample volume required makes it possible to subsample the air in flasks for CO(2) and then to sample the remaining air volume for the analysis of the isotopic composition of either methane or nitrous oxide. Reliable delta(13)C and delta(18)O values can be obtained from samples collected and stored for 1-3 days. Longer-term storage, on the order of weeks, is possible for delta(13)C measurements without drift in the isotope ratio signal, and should also be possible for delta(18)O measurements. When linked with an infrared gas analyzer, pump and flask sampling system, it is feasible to sample CO(2) extensively in remote forest locations. The air-sampling system was used to measure the isotope ratios of atmospheric CO(2) and to conduct a regression analysis of the relationship between these two parameters. From the regression, we calculated the delta(13)C of ecosystem respiration of four coniferous ecosystems along a precipitation gradient in central Oregon. The ecosystems along the coast-to-interior Oregon (OTTER) gradient are dominated by spruce-hemlock forests at the wet, coastal sites (> 200 cm precipitation annually) to juniper woodlands (20 cm precipitation) at the interior, dry end of the transect. The delta(13)C values of ecosystem respiration along this transect differed by only 1.3 per thousand (range of -25.2 to -23.9 per thousand ) during August at the peak of the summer drought. Following autumn rains in September, the delta(13)C of ecosystem respiration in the four stands decreased; overall the difference in the carbon isotope ratio of ecosystem respiration among sites increased to 3.9 per thousand (-26.8 to -22.9 per thousand ).

GAS CHROMATOGRAPHIC TECHNIQUES FOR THE MEASUREMENT OF ISOPRENE IN AIR

EPA Science Inventory

The chapter discusses gas chromatographic techniques for measuring isoprene in air. Such measurement basically consists of three parts: (1) collection of sufficient sample volume for representative and accurate quantitation, (2) separation (if necessary) of isoprene from interfer...

[Environmental investigation of ground water contamination at Wright-Patterson Air Force Base, Ohio]. Volume 5, Appendix A, Part 1, Field Investigation report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1992-03-01

This report presents information related to the sampling of ground water at the Wright-Patterson Air Force Base. It is part of an investigation into possible ground water contamination. Information concerns well drilling/construction; x-ray diffraction and sampling; soil boring logs; and chain-of-custody records.

Installation restoration program. Site investigation report, IRP sites No. 1, No. 2, and No. 3. 106th Civil Engineering Flight, New York Air National Guard, Roslyn Air National Guard Station, Roslyn, New York. Volume 3, Appendix H. Site Investigation report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-11-01

This report is a continuation of the Installation Restoration Program site investigation report for IRP Sites No. 1, No. 2 and No. 3 at the Air National Guard, Rosyln, New York. The Sample Delivery Group (SDG) narratives and quality assurance/quality control analytical results of eighteen samples are reported.

Field Sampling Plan/Quality Assurance Project Plan Volume I of III

EPA Pesticide Factsheets

This document contains procedures related to the collection and analysis of soil, sediment, groundwater, surface water, air and biota samples at GE’s Pittsfield, Massachusetts facility and at other areas.

Aircraft data summaries for the SURE intensives. Final report. [Sampling done October, 1978 near Duncan Falls, Ohio and Giles County, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keifer, W.S.; Blumenthal, D.L.; Tommerdahl, J.B.

1981-09-01

As part of the EPRI sulfate regional experiment (SURE), Meteorology Research, Inc., (MRI) and Research Triangle Institute (RTI) conducted six air quality sampling programs in the eastern United States using instrumented aircraft. This volume includes the air quality and meteorological data obtained during the October 1978 intensive when MRI sampled near the Giles County, Tennessee, SURE Station and RTI sampled near the Duncan Falls, Ohio, SURE Station. Sampling data are presented for all measured parameters.

Quality Control for Ambient Sampling of PCDD/PCDF from Open Combustion Sources

EPA Science Inventory

Both long duration (> 6 h) and high temperature (up to 139o C) sampling efforts were conducted using ambient air sampling methods to determine if either high volume throughput or higher than ambient sampling temperatures resulted in loss of target polychlorinated dibenzodioxins/d...

Passive air sampling theory for semivolatile organic compounds.

PubMed

Bartkow, Michael E; Booij, Kees; Kennedy, Karen E; Müller, Jochen F; Hawker, Darryl W

2005-07-01

The mathematical modelling underlying passive air sampling theory can be based on mass transfer coefficients or rate constants. Generally, these models have not been inter-related. Starting with basic models, the exchange of chemicals between the gaseous phase and the sampler is developed using mass transfer coefficients and rate constants. Importantly, the inter-relationships between the approaches are demonstrated by relating uptake rate constants and loss rate constants to mass transfer coefficients when either sampler-side or air-side resistance is dominating chemical exchange. The influence of sampler area and sampler volume on chemical exchange is discussed in general terms and as they relate to frequently used parameters such as sampling rates and time to equilibrium. Where air-side or sampler-side resistance dominates, an increase in the surface area of the sampler will increase sampling rates. Sampling rates are not related to the sampler/air partition coefficient (K(SV)) when air-side resistance dominates and increase with K(SV) when sampler-side resistance dominates.

CTEPP NC DATA SUPPLEMENTAL INFORMATION ON FIELD AND LABORATORY SAMPLES

EPA Science Inventory

This data set contains supplemental data related to the final core analytical results table. This includes sample collection data for example sample weight, air volume, creatinine, specific gravity etc.

The Children’s Total Exposure to Persistent Pesticides and Other Persistent...

Decreasing carbon monoxide in the diving air of artisanal fishermen in the Yucatán peninsula by separation of engine exhaust from compressor intake.

PubMed

Chin, Walter; Huchim-Lara, Oswaldo; Salas, Silvia

2016-01-01

Artisanal fishermen in the Yucatán Peninsula utilize hookah dive systems (HDS). The air compressors in these HDS are not filtered, and the intake is near the engine exhaust. This proximity allows carbon monoxide (CO) from the exhaust to directly enter the HDS volume tank and contaminate the fishermen diver's air supply. Conservative safety standards permit a diver's air supply to contain 10 parts per million (ppm) of CO. This study quantified the levels of CO in the diver's air supply both before and after physical separation of the engine exhaust from the compressor intake. CO levels in seven volume tanks were analyzed before and after a 1-inch hose was attached to the compressor intake and elevated 5 feet above the engine exhaust. The tanks were drained and refilled before collecting each set of pre- and post-intervention gas samples. Four CO measurements were collected before and after the intervention from each volume tank. A C-Squared© CO Analyzer (± 1 ppm), calibrated with a Praxair 70 ppm CON2 gas (± 5%), was used to analyze the gas samples. A paired samples t-test shows a statistically significant difference in average CO values before and after the intervention (t = 6.8674, df: 27; p⟨0.0001). The physical separation of the engine exhaust from the compressor intake reduced the CO contamination of the diver air supply by 72%. This intervention could be applied to the hookah systems in the rest of the fishing cooperative to reduce the divers' risk of CO poisoning. Copyright© Undersea and Hyperbaric Medical Society.

Venturi air-jet vacuum ejectors for high-volume atmospheric sampling on aircraft platforms

NASA Technical Reports Server (NTRS)

Hill, Gerald F.; Sachse, Glen W.; Young, Douglas C.; Wade, Larry O.; Burney, Lewis G.

1992-01-01

Documentation of the installation and use of venturi air-jet vacuum ejectors for high-volume atmospheric sampling on aircraft platforms is presented. Information on the types of venturis that are useful for meeting the pumping requirements of atmospheric-sampling experiments is also presented. A description of the configuration and installation of the venturi system vacuum line is included with details on the modifications that were made to adapt a venturi to the NASA Electra aircraft at GSFC, Wallops Flight Facility. Flight test results are given for several venturis with emphasis on applications to the Differential Absorption Carbon Monoxide Measurement (DACOM) system at LaRC. This is a source document for atmospheric scientists interested in using the venturi systems installed on the NASA Electra or adapting the technology to other aircraft.

A source of PCB contamination in modified high-volume air samplers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Basu, I.; O'Dell, J.M.; Arnold, K.

2000-02-01

Modified Anderson High Volume (Hi-Vol) air samplers are widely used for the collection of semi-volatile organic compounds (such as PCBs) from air. The foam gasket near the main air flow path in these samplers can become contaminated with PCBs if the sampler or the gasket is stored at a location with high indoor air PCB levels. Once the gasket is contaminated, it releases PCBs back into the air stream during sampling, and as a result, incorrectly high air PCB concentrations are measured. This paper presents data demonstrating this contamination problem using measurements from two Integrated Atmospheric Deposition Network sites: onemore » at Sleeping Bear Dunes on Lake Michigan and the other at Point Petre on Lake Ontario. The authors recommend that these gaskets be replaced by Teflon tape and that the storage history of each sampler be carefully tracked.« less

Multistage open-tube trap for enrichment of part-per-trillion trace components of low-pressure (below 27-kPa) air samples

NASA Technical Reports Server (NTRS)

Ohara, D.; Vo, T.; Vedder, J. F.

1985-01-01

A multistage open-tube trap for cryogenic collection of trace components in low-pressure air samples is described. The open-tube design allows higher volumetric flow rates than densely packed glass-bead traps commonly reported and is suitable for air samples at pressures below 27 kPa with liquid nitrogen as the cryogen. Gas blends containing 200 to 2500 parts per trillion by volume each of ethane and ethene were sampled and hydrocarbons were enriched with 100 + or - 4 percent trap efficiency. The multistage design is more efficient than equal-length open-tube traps under the conditions of the measurements.

Aircraft data summaries for the SURE intensives. Final report. [Data obtained during January/February 1978 near Duncan Falls, Ohio and Lewisburg, Virginia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Keifer, W.S.; Blumenthal, D.L.; Tommerdahl, J.B.

1981-09-01

As part of the EPRI sulfate regional experiment (SURE), Meteorology Research, Inc., (MRI) and Research Triangle Institute (RTI) conducted six air quality sampling programs in the eastern United States using instrumented aircraft. This volume includes the air quality and meteorological data obtained during the January/February 1978 Intensive when MRI sampled near the Duncan Falls, Ohio, SURE Station and RTI sampled near the Lewisburg, Virginia, SURE Station. Sampling data are presented for all measured parameters.

Ozone measurements

NASA Technical Reports Server (NTRS)

Randhawa, J.

1978-01-01

The chemiluminescent ozonesonde to be flown with the STRATCOM balloon flight consisted of two main parts: (1) A constant-volume sampling pump made from TEFLON was used for the intake of the air sample. Sample was drawn at a rate of 200 millimeters per minute. (2) Ozone was detected by the chemiluminescent process (Rhodamine - B). Ozone molecules in the air sample flowed over the detector and the photons produced by the destruction of ozone molecules on the chemiluminescent material were monitored by the photomultiplier tube, the output signal from which was transmitted to the ground receiver.

CTEPP-OH DATA SUPPLEMENTAL INFORMATION ON FIELD AND LABORATORY SAMPLES

EPA Science Inventory

This data set contains supplemental data related to the final core analytical results table for CTEPP-OH. This includes sample collection data for example sample weight, air volume, creatinine, specific gravity etc.

The Children’s Total Exposure to Persistent Pesticides and Oth...

Whole air canister sampling coupled with preconcentration GC/MS analysis of part-per-trillion levels of trimethylsilanol in semiconductor cleanroom air.

PubMed

Herrington, Jason S

2013-08-20

The costly damage airborne trimethylsilanol (TMS) exacts on optics in the semiconductor industry has resulted in the demand for accurate and reliable methods for measuring TMS at trace levels (i.e., parts per trillion, volume per volume of air [ppt(v)] [~ng/m(3)]). In this study I developed a whole air canister-based approach for field sampling trimethylsilanol in air, as well as a preconcentration gas chromatography/mass spectrometry laboratory method for analysis. The results demonstrate clean canister blanks (0.06 ppt(v) [0.24 ng/m(3)], which is below the detection limit), excellent linearity (a calibration relative response factor relative standard deviation [RSD] of 9.8%) over a wide dynamic mass range (1-100 ppt(v)), recovery/accuracy of 93%, a low selected ion monitoring method detection limit of 0.12 ppt(v) (0.48 ng/m(3)), replicate precision of 6.8% RSD, and stability (84% recovery) out to four days of storage at room temperature. Samples collected at two silicon wafer fabrication facilities ranged from 10.0 to 9120 ppt(v) TMS and appear to be associated with the use of hexamethyldisilazane priming agent. This method will enable semiconductor cleanroom managers to monitor and control for trace levels of trimethylsilanol.

Use of Whatman-41 filters in air quality sampling networks (with applications to elemental analysis)

NASA Technical Reports Server (NTRS)

Neustadter, H. E.; Sidik, S. M.; King, R. B.; Fordyce, J. S.; Burr, J. C.

1974-01-01

The operation of a 16-site parallel high volume air sampling network with glass fiber filters on one unit and Whatman-41 filters on the other is reported. The network data and data from several other experiments indicate that (1) Sampler-to-sampler and filter-to-filter variabilities are small; (2) hygroscopic affinity of Whatman-41 filters need not introduce errors; and (3) suspended particulate samples from glass fiber filters averaged slightly, but not statistically significantly, higher than from Whatman-41-filters. The results obtained demonstrate the practicability of Whatman-41 filters for air quality monitoring and elemental analysis.

Breakthrough during air sampling with polyurethane foam: What do PUF 2/PUF 1 ratios mean?

PubMed

Bidleman, Terry F; Tysklind, Mats

2018-02-01

Frontal chromatography theory is applied to describe movement of gaseous semivolatile organic compounds (SVOCs) through a column of polyurethane foam (PUF). Collected mass fractions (F C ) are predicted for sample volume/breakthrough volume ratios (τ = V S /V B ) up to 6.0 and PUF bed theoretical plate numbers (N) from 2 to 16. The predictions assume constant air concentrations and temperatures. Extension of the calculations is done to relate the collection efficiency of a 2-PUF train (F C1+2 ) to the PUF 2/PUF 1 ratio. F C1+2 exceeds 0.9 for PUF 2/PUF 1 ≤ 0.5 and lengths of PUF commonly used in air samplers. As the PUF 2/PUF 1 ratio approaches unity, confidence in these predictions is limited by the analytical ability to distinguish residues on the two PUFs. Field data should not be arbitrarily discarded because some analytes broke through to the backup PUF trap. The fractional collection efficiencies can be used to estimate air concentrations from quantities retained on the PUF trap when sampling is not quantitative. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analytical method validation for the determination of 2,3,3,3-tetrafluoropropene in air samples using gas chromatography with flame ionization detection.

PubMed

Mawn, Michael P; Kurtz, Kristine; Stahl, Deborah; Chalfant, Richard L; Koban, Mary E; Dawson, Barbara J

2013-01-01

A new low global warming refrigerant, 2,3,3,3-tetrafluoro propene, or HFO-1234yf, has been successfully evaluated for automotive air conditioning, and is also being evaluated for stationary refrigeration and air conditioning systems. Due to the advantageous environmental properties of HFO-1234yf versus HFC-134a, coupled with its similar physical properties and system performance, HFO-1234yf is also being evaluated to replace HFC-134a in refrigeration applications where neat HFC-134a is currently used. This study reports on the development and validation of a sampling and analytical method for the determination of HFO-1234yf in air. Different collection media were screened for desorption and simulated sampling efficiency with three-section (350/350/350 mg) Anasorb CSC showing the best results. Therefore, air samples were collected using two 3-section Anasorb CSC sorbent tubes in series at 0.02 L/min for up to 8 hr for sample volumes of up to 9.6 L. The sorbent tubes were extracted in methylene chloride, and analyzed by gas chromatography with flame ionization detection. The method was validated from 0.1× to 20× the target level of 0.5 ppm (2.3 mg/m(3)) for a 9.6 L air volume. Desorption efficiencies for HFO-1234yf were 88 to 109% for all replicates over the validation range with a mean overall recovery of 93%. Simulated sampling efficiencies ranged from 87 to 104% with a mean of 94%. No migration or breakthrough to the back tube was observed under the sampling conditions evaluated. HFO-1234yf samples showed acceptable storage stability on Anasorb CSC sorbent up to a period of 30 days when stored under ambient, refrigerated, or frozen temperature conditions.

Molecular detection of airborne Coccidioides in Tucson, Arizona

USGS Publications Warehouse

Chow, Nancy A.; Griffin, Dale W.; Barker, Bridget M.; Loparev, Vladimir N.; Litvintseva, Anastasia P.

2016-01-01

Environmental surveillance of the soil-dwelling fungus Coccidioides is essential for the prevention of Valley fever, a disease primarily caused by inhalation of the arthroconidia. Methods for collecting and detectingCoccidioides in soil samples are currently in use by several laboratories; however, a method utilizing current air sampling technologies has not been formally demonstrated for the capture of airborne arthroconidia. In this study, we collected air/dust samples at two sites (Site A and Site B) in the endemic region of Tucson, Arizona, and tested a variety of air samplers and membrane matrices. We then employed a single-tube nested qPCR assay for molecular detection. At both sites, numerous soil samples (n = 10 at Site A and n = 24 at Site B) were collected and Coccidioides was detected in two samples (20%) at Site A and in eight samples (33%) at Site B. Of the 25 air/dust samples collected at both sites using five different air sampling methods, we detected Coccidioides in three samples from site B. All three samples were collected using a high-volume sampler with glass-fiber filters. In this report, we describe these methods and propose the use of these air sampling and molecular detection strategies for environmental surveillance of Coccidioides.

Measurement of the resistivity of porous materials with an alternating air-flow method.

PubMed

Dragonetti, Raffaele; Ianniello, Carmine; Romano, Rosario A

2011-02-01

Air-flow resistivity is a main parameter governing the acoustic behavior of porous materials for sound absorption. The international standard ISO 9053 specifies two different methods to measure the air-flow resistivity, namely a steady-state air-flow method and an alternating air-flow method. The latter is realized by the measurement of the sound pressure at 2 Hz in a small rigid volume closed partially by the test sample. This cavity is excited with a known volume-velocity sound source implemented often with a motor-driven piston oscillating with prescribed area and displacement magnitude. Measurements at 2 Hz require special instrumentation and care. The authors suggest an alternating air-flow method based on the ratio of sound pressures measured at frequencies higher than 2 Hz inside two cavities coupled through a conventional loudspeaker. The basic method showed that the imaginary part of the sound pressure ratio is useful for the evaluation of the air-flow resistance. Criteria are discussed about the choice of a frequency range suitable to perform simplified calculations with respect to the basic method. These criteria depend on the sample thickness, its nonacoustic parameters, and the measurement apparatus as well. The proposed measurement method was tested successfully with various types of acoustic materials.

DICARBOXYLIC ACID CONCENTRATION TRENDS AND SAMPLING ARTIFACTS

EPA Science Inventory

Dicarboxylic acids associated with airborne particulate matter were measured during a summer period in Philadelphia that included multiple air pollution episodes. Samples were collected for two ten hour periods each day using a high volume sampler with two quartz fiber filters in...

Colorimetric-Solid Phase Extraction Technology for Water Quality Monitoring: Evaluation of C-SPE and Debubbling Methods in Microgravity

NASA Technical Reports Server (NTRS)

Hazen-Bosveld, April; Lipert, Robert J.; Nordling, John; Shih, Chien-Ju; Siperko, Lorraine; Porter, Marc D.; Gazda, Daniel B.; Rutz, Jeff A.; Straub, John E.; Schultz, John R.;

Nonmethane organic compound monitoring program. Final report 1988. Volume 2. Urban air toxics monitoring program

DOE Office of Scientific and Technical Information (OSTI.GOV)

McAllister, R.A.; Moore, W.H.; Rice, J.

1989-04-01

From October, 1987 to October, 1988 samples of ambient air were collected at 19 sites in the eastern part of the U.S. Every 12 days, air was integrated over 24-hour periods into passivated stainless steel canisters. Simultaneously, air was drawn through cartridges containing dinitrophenylhydrazine to collect carbonyl compounds. The samples were analyzed at a central laboratory for a total of 37 halogenated and aromatic hydrocarbons, formaldehyde, acetaldehyde, and other oxygenated species. The hydrocarbon species were analyzed by gas chromatography/multiple detectors and gas chromatography/mass spectrometry, while the carbonyl species were analyzed by liquid chromatography. An extensive quality assurance program was carriedmore » on to secure high quality data. Complete data for all the hydrocarbon samples are presented in the report.« less

Liquid Metering Centrifuge Sticks (LMCS): A Centrifugal Approach to Metering Known Sample Volumes for Colorimetric Solid Phase Extraction (C-SPE)

NASA Technical Reports Server (NTRS)

Gazda, Daniel B.; Schultz, John R.; Clarke, Mark S.

2007-01-01

Phase separation is one of the most significant obstacles encountered during the development of analytical methods for water quality monitoring in spacecraft environments. Removing air bubbles from water samples prior to analysis is a routine task on earth; however, in the absence of gravity, this routine task becomes extremely difficult. This paper details the development and initial ground testing of liquid metering centrifuge sticks (LMCS), devices designed to collect and meter a known volume of bubble-free water in microgravity. The LMCS uses centrifugal force to eliminate entrapped air and reproducibly meter liquid sample volumes for analysis with Colorimetric Solid Phase Extraction (C-SPE). C-SPE is a sorption-spectrophotometric platform that is being developed as a potential spacecraft water quality monitoring system. C-SPE utilizes solid phase extraction membranes impregnated with analyte-specific colorimetric reagents to concentrate and complex target analytes in spacecraft water samples. The mass of analyte extracted from the water sample is determined using diffuse reflectance (DR) data collected from the membrane surface and an analyte-specific calibration curve. The analyte concentration can then be calculated from the mass of extracted analyte and the volume of the sample analyzed. Previous flight experiments conducted in microgravity conditions aboard the NASA KC-135 aircraft demonstrated that the inability to collect and meter a known volume of water using a syringe was a limiting factor in the accuracy of C-SPE measurements. Herein, results obtained from ground based C-SPE experiments using ionic silver as a test analyte and either the LMCS or syringes for sample metering are compared to evaluate the performance of the LMCS. These results indicate very good agreement between the two sample metering methods and clearly illustrate the potential of utilizing centrifugal forces to achieve phase separation and metering of water samples in microgravity.

Target location after deep cerebral biopsies using low-volume air injection in 75 patients. Results and technical note.

PubMed

Poca, Maria A; Martínez-Ricarte, Francisco-Ramon; Gándara, Dario F; Coscojuela, Pilar; Martínez-Sáez, Elena; Sahuquillo, Juan

2017-10-01

Stereotactic biopsy is a minimally invasive technique that allows brain tissue samples to be obtained with low risk. Classically, different techniques have been used to identify the biopsy site after surgery. To describe a technique to identify the precise location of the target in the postoperative CT scan using the injection of a low volume of air into the biopsy cannula. Seventy-five biopsies were performed in 65 adults and 10 children (40 males and 35 females, median age 51 years). Frame-based biopsy was performed in 46 patients, while frameless biopsy was performed in the remaining 29 patients. In both systems, after brain specimens had been collected and with the biopsy needle tip in the center of the target, a small volume of air (median 0.7 cm 3 ) was injected into the site. A follow-up CT scan was performed in all patients. Intracranial air in the selected target was present in 69 patients (92%). No air was observed in two patients (air volume administered in these 2 cases was below 0.7 cm 3 ), while in the remaining four patients blood content was observed in the target. The diagnostic yield in this series was 97.3%. No complications were found to be associated with intracranial air injection in any of the 75 patients who underwent this procedure. The air-injection maneuver proposed for use in stereotactic biopsies of intracranial mass lesions is a safe and reliable technique that allows the exact biopsy site to be located without any related complications.

Legionnaires' Disease Bacteria in power plant cooling systems: downtime report. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.; Solomon, J.A.; Christensen, S.W.

1985-04-01

Legionnaires' Disease Bacteria (Legionella) are a normal part of the aquatic community that, when aerosolized, can be pathogenic to man. The downtime study was designed to determine the degree to which Legionella populations are aerosolized during cleaning and maintenance operations in a closed-cycle steam-electric power plant. Both high-volume and impinger air samples were collected prior to and during downtime operations. Emphasis was placed on sampling inside or adjacent to water boxes, condensers, and cooling towers. Control air samples were taken upwind from the plant site. Water and sludge samples were also collected at various locations. In the laboratory, the concentrationsmore » of Groups A, B, and C Legionella were determined using the direct fluorescent antibody method. All positive air samples, and other selected air samples, were injected into guinea pigs to detect infectious Legionella. Legionella could be detected in only 12 of the 126 air samples collected. These were predominantly Group A Legionella (L. pneumophila, serogroups 1 to 6). All 12 positive samples had been collected in the vicinity of water boxes, condensers, detention ponds, and cooling towers during downtime operations where aerosolization of Legionella populations would be expected. None of the air samples yielded infectious Legionella when injected into guinea pigs. Detection of Legionella in air samples taken during downtime was significantly more likely than detection during normal operating conditions (p <0.01). 13 refs., 4 figs., 10 tabs.« less

A Comparison Study of Sampling and Analyzing Volatile Organic Compounds in Air in Kuwait by Using Tedlar Bags/Canisters and GC-MS with a Cryogenic Trap

PubMed Central

Tang, Hongmao; Beg, Khaliq R.; Al-Otaiba, Yousef

2006-01-01

Kuwait experiences desert climatic weather. Due to the extreme hot and dry conditions in this country, some analytical phenomena have been discovered. Therefore, a systematic study of sampling and analyzing volatile organic compounds in air by using GC-MS with a cryogenic trap is reported in this paper. This study included comparisons of using different sample containers such as Tedlar bags and SUMMA canisters, and different cryogenic freezing-out air volumes in the trap. Calibration curves for different compounds and improvement of replicated analysis results were also reported here. The study found that using different sample containers produced different results. Analysis of ambient air samples collected in Tedlar bags obtained several volatile organic compounds with large concentrations compared to using SUMMA canisters. Therefore, to choose a sample container properly is a key element for successfully completing a project. Because GC-MS with a cryogenic trap often generates replicated results with poor agreement, an internal standard added to gas standards and air samples by using a gas syringe was tested. The study results proved that it helped to improve the replicated results. PMID:16699723

A comparison study of sampling and analyzing volatile organic compounds in air in Kuwait by using Tedlar bags/canisters and GC-MS with a cryogenic trap.

PubMed

Tang, Hongmao; Beg, Khaliq R; Al-Otaiba, Yousef

2006-05-12

Kuwait experiences desert climatic weather. Due to the extreme hot and dry conditions in this country, some analytical phenomena have been discovered. Therefore, a systematic study of sampling and analyzing volatile organic compounds in air by using GC-MS with a cryogenic trap is reported in this paper. This study included comparisons of using different sample containers such as Tedlar bags and SUMMA canisters, and different cryogenic freezing-out air volumes in the trap. Calibration curves for different compounds and improvement of replicated analysis results were also reported here. The study found that using different sample containers produced different results. Analysis of ambient air samples collected in Tedlar bags obtained several volatile organic compounds with large concentrations compared to using SUMMA canisters. Therefore, to choose a sample container properly is a key element for successfully completing a project. Because GC-MS with a cryogenic trap often generates replicated results with poor agreement, an internal standard added to gas standards and air samples by using a gas syringe was tested. The study results proved that it helped to improve the replicated results.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, R; Bai, W

Purpose: Because of statistical noise in Monte Carlo dose calculations, effective point doses may not be accurate. Volume spheres are useful for evaluating dose in Monte Carlo plans, which have an inherent statistical uncertainty.We use a user-defined sphere volume instead of a point, take sphere sampling around effective point make the dose statistics to decrease the stochastic errors. Methods: Direct dose measurements were made using a 0.125cc Semiflex ion chamber (IC) 31010 isocentrically placed in the center of a homogeneous Cylindric sliced RW3 phantom (PTW, Germany).In the scanned CT phantom series the sensitive volume length of the IC (6.5mm) weremore » delineated and defined the isocenter as the simulation effective points. All beams were simulated in Monaco in accordance to the measured model. In our simulation using 2mm voxels calculation grid spacing and choose calculate dose to medium and request the relative standard deviation ≤0.5%. Taking three different assigned IC over densities (air electron density(ED) as 0.01g/cm3 default CT scanned ED and Esophageal lumen ED 0.21g/cm3) were tested at different sampling sphere radius (2.5, 2, 1.5 and 1 mm) statistics dose were compared with the measured does. Results: The results show that in the Monaco TPS for the IC using Esophageal lumen ED 0.21g/cm3 and sampling sphere radius 1.5mm the statistical value is the best accordance with the measured value, the absolute average percentage deviation is 0.49%. And when the IC using air electron density(ED) as 0.01g/cm3 and default CT scanned EDthe recommented statistical sampling sphere radius is 2.5mm, the percentage deviation are 0.61% and 0.70%, respectivly. Conclusion: In Monaco treatment planning system for the ionization chamber 31010 recommend air cavity using ED 0.21g/cm3 and sampling 1.5mm sphere volume instead of a point dose to decrease the stochastic errors. Funding Support No.C201505006.« less

Can car air filters be useful as a sampling medium for air pollution monitoring purposes?

PubMed

Katsoyiannis, Athanasios; Birgul, Askin; Ratola, Nuno; Cincinelli, Alessandra; Sweetman, Andy J; Jones, Kevin C

2012-11-01

Urban air quality and real human exposure to chemical environmental stressors is an issue of high scientific and political interest. In an effort to find innovative and inexpensive means for air quality monitoring, the ability of car engine air filters (CAFs) to act as efficient samplers collecting street level air, to which people are exposed to, was tested. In particular, in the case of taxis, air filters are replaced after regular distances, the itineraries are almost exclusively urban, cruising mode is similar and, thus, knowledge of the air flow can provide with an integrated city air sample. The present pilot study focused on polycyclic aromatic hydrocarbons (PAHs), the most important category of organic pollutants associated with traffic emissions. Concentrations of ΣPAHs in CAFs ranged between 650 and 2900 μg CAF(-1), with benzo[b]fluoranthene, benzo[k]fluoranthene and indeno[123-cd]pyrene being the most abundant PAHs. Benzo[a]pyrene (BaP) ranged between 110 and 250 μg CAF(-1), accounting regularly for 5-15% of the total carcinogenic PAHs. The CAF PAH loads were used to derive road-level atmospheric PAH concentrations from a standard formula relating to the CAF air flow. Important parameters/assumptions for these estimates are the cruising speed and the exposure duration of each CAF. Based on information obtained from the garage experts, an average 'sampled air volume' of 48,750 m(3) per CAF was estimated, with uncertainty in this calculation estimated to be about a factor of 4 between the two extreme scenarios. Based on this air volume, ΣPAHs ranged between 13 and 56 ng m(-3) and BaP between 2.1 and 5.0 ng m(-3), suggesting that in-traffic BaP concentrations can be many times higher than the limit values set by the UK (0.25 ng m(-3)) and the European Union (1.0 ng m(-3)), or from active sampling stations normally cited on building roof tops or far from city centres. Notwithstanding the limitations of this approach, the very low cost, the continuous availability of very high amounts of "sample", and the "retroactivity" render it very useful and complementary to existing passive sampling techniques. This approach yields estimated air concentrations that reflect the pollutant concentrations to which taxi drivers, pedestrians, cyclists and road-related professionals are exposed. Copyright © 2012 Elsevier Ltd. All rights reserved.

Optimization of sampling parameters for collection and preconcentration of alveolar air by needle traps.

PubMed

Filipiak, Wojciech; Filipiak, Anna; Ager, Clemens; Wiesenhofer, Helmut; Amann, Anton

2012-06-01

The approach for breath-VOCs' collection and preconcentration by applying needle traps was developed and optimized. The alveolar air was collected from only a few exhalations under visual control of expired CO(2) into a large gas-tight glass syringe and then warmed up to 45 °C for a short time to avoid condensation. Subsequently, a specially constructed sampling device equipped with Bronkhorst® electronic flow controllers was used for automated adsorption. This sampling device allows time-saving collection of expired/inspired air in parallel onto three different needle traps as well as improvement of sensitivity and reproducibility of NT-GC-MS analysis by collection of relatively large (up to 150 ml) volume of exhaled breath. It was shown that the collection of alveolar air derived from only a few exhalations into a large syringe followed by automated adsorption on needle traps yields better results than manual sorption by up/down cycles with a 1 ml syringe, mostly due to avoided condensation and electronically controlled stable sample flow rate. The optimal profile and composition of needle traps consists of 2 cm Carbopack X and 1 cm Carboxen 1000, allowing highly efficient VOCs' enrichment, while injection by a fast expansive flow technique requires no modifications in instrumentation and fully automated GC-MS analysis can be performed with a commercially available autosampler. This optimized analytical procedure considerably facilitates the collection and enrichment of alveolar air, and is therefore suitable for application at the bedside of critically ill patients in an intensive care unit. Due to its simplicity it can replace the time-consuming sampling of sufficient breath volume by numerous up/down cycles with a 1 ml syringe.

Installation restoration program. Site investigation report, IRP sites No. 1, No. 2, and No. 3. 106th Civil Engineering Flight, New York Air National Guard, Roslyn Air National Guard Station, Roslyn, New York. Volume 4, appendices I-J. Site Investigation report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-11-01

This report is the continuation of the Installation Restoration Program Site Investigation report IRP Sites No. 1, No. 2, and No. 3 at the Air National Guard, Roslyn, New York. The chemical analyses results for soil and ground water samples is reported.

High Volume Air Sampling for Viral Aerosols: A Comparative Approach

DTIC Science & Technology

2010-03-01

Solid Impaction Aerosol Collection (Verreault, 2008. Reproduced with Permission from American Society of Microbiology ) Liquid collection...Reproduced with Permission from American Society of Microbiology ) Filter aerosol collection is often more efficient than other sampling...collected using a crude filter consisting of a glass tube packed with dry cotton. Sample analysis was conducted by inoculating chicken embryos with

Legionnaires' disease bacteria in power plant cooling systems: downtime report. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyndall, R.L.; Solomon, J.A.; Christensen, S.W.

1985-11-01

Legionnaires' disease bacteria (Legionella) are a normal part of the aquatic community that, when aerosolized, can be pathogenic to man. The downtime study was designed to determine the degree to which Legionella populations are aerosolized during cleaning and maintenance operations in a closed-cycle steam-electric power plant. Both high-volume and impinger air samples were collected prior to and during downtime operations. Emphasis was placed on sampling inside or adjacent to water boxes, condensers, and cooling towers. Control air samples were taken upwind from the plant site. Water and sludge samples were also collected at various locations. In the laboratory, the concentrationsmore » of Legionella were determined using the direct fluorescent antibody method. All positive air samples, and other selected air samples, were injected into guinea pigs to detect infectious Legionella. Legionella could be detected in only 12 of the 127 air samples collected. These were predominantly L. pneumophila, serogroups 1-6. In contrast to the air samples, most of the water and sludge samples were positive for Legionella, again predominantly L. pneumophila, serogroups 1-6. The highest Legionella concentrations were found in sludge samples associated with condenser tube cleaning. Among the water samples, the highest Legionella concentrations were found in cooling towers, immediately after the tower basins were cleaned and refilled, and in condenser tubes. Two of the three cooling tower water samples collected prior to downtime operations were infectious for guinea pigs. 16 refs., 4 figs., 11 tabs.« less

Personal exposure to aerosolized red tide toxins (brevetoxins).

PubMed

Cheng, Yung Sung; Zhou, Yue; Naar, Jerome; Irvin, C Mitch; Su, Wei-Chung; Fleming, Lora E; Kirkpatrick, Barbara; Pierce, Richard H; Backer, Lorraine C; Baden, Daniel G

2010-06-01

Florida red tides occur annually in the Gulf of Mexico from blooms of the marine dinoflagellate, Karenia brevis, which produces highly potent natural polyether toxins, brevetoxins. Several epidemiologic studies have demonstrated that human exposure to red tide aerosol could result in increased respiratory symptoms. Environmental monitoring of aerosolized brevetoxins was performed using a high-volume sampler taken hourly at fixed locations on Siesta Beach, Florida. Personal exposure was monitored using personal air samplers and taking nasal swab samples from the subjects who were instructed to spend 1 hr on Sarasota Beach during two sampling periods of an active Florida red tide event in March 2005, and in May 2008 when there was no red tide. Results showed that the aerosolized brevetoxins from the personal sampler were in modest agreement with the environmental concentration taken from a high-volume sampler. Analysis of nasal swab samples for brevetoxins demonstrated 68% positive samples in the March 2005 sampling period when air concentrations of brevetoxins were between 50 to 120 ng/m(3) measured with the high-volume sampler. No swab samples showed detectable levels of brevetoxins in the May 2008 study, when all personal samples were below the limit of detection. However, there were no statistical correlations between the amounts of brevetoxins detected in the swab samples with either the environmental or personal concentration. Results showed that the personal sample might provide an estimate of individual exposure level. Nasal swab samples showed that brevetoxins indeed were inhaled and deposited in the nasal passage during the March 2005 red tide event.

Method and apparatus for sampling atmospheric mercury

DOEpatents

Trujillo, Patricio E.; Campbell, Evan E.; Eutsler, Bernard C.

1976-01-20

A method of simultaneously sampling particulate mercury, organic mercurial vapors, and metallic mercury vapor in the working and occupational environment and determining the amount of mercury derived from each such source in the sampled air. A known volume of air is passed through a sampling tube containing a filter for particulate mercury collection, a first adsorber for the selective adsorption of organic mercurial vapors, and a second adsorber for the adsorption of metallic mercury vapor. Carbon black molecular sieves are particularly useful as the selective adsorber for organic mercurial vapors. The amount of mercury adsorbed or collected in each section of the sampling tube is readily quantitatively determined by flameless atomic absorption spectrophotometry.

Changes in the electro-physical properties of MCT epitaxial films affected by a plasma volume discharge induced by an avalanche beam in atmospheric-pressure air

NASA Astrophysics Data System (ADS)

Grigoryev, D. V.; Voitsekhovskii, A. V.; Lozovoy, K. A.; Tarasenko, V. F.; Shulepov, M. A.

2015-11-01

In this paper the influence of the plasma volume discharge of nanosecond duration formed in a non-uniform electric field at atmospheric pressure on samples of epitaxial films HgCdTe (MCT) films are discussed. The experimental data show that the action of pulses of nanosecond volume discharge in air at atmospheric pressure leads to changes in the electrophysical properties of MCT epitaxial films due to formation of a near-surface high- conductivity layer of the n-type conduction. The preliminary results show that it is possible to use such actions in the development of technologies for the controlled change of the properties of MCT.

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Alpha Air Sample Counting Efficiency Versus Dust Loading: Evaluation of a Large Data Set

DOE PAGES

Hogue, M. G.; Gause-Lott, S. M.; Owensby, B. N.; ...

2018-03-03

Dust loading on air sample filters is known to cause a loss of efficiency for direct counting of alpha activity on the filters, but the amount of dust loading and the correction factor needed to account for attenuated alpha particles is difficult to assess. In this paper, correction factors are developed by statistical analysis of a large database of air sample results for a uranium and plutonium processing facility at the Savannah River Site. As is typically the case, dust-loading data is not directly available, but sample volume is found to be a reasonable proxy measure; the amount of dustmore » loading is inferred by a combination of the derived correction factors and a Monte Carlo model. The technique compares the distribution of activity ratios [beta/(beta + alpha)] by volume and applies a range of correction factors on the raw alpha count rate. The best-fit results with this method are compared with MCNP modeling of activity uniformly deposited in the dust and analytical laboratory results of digested filters. Finally, a linear fit is proposed to evenly-deposited alpha activity collected on filters with dust loading over a range of about 2 mg cm -2 to 1,000 mg cm -2.« less

Effects of breathing pattern and inspired air conditions on breath condensate volume, pH, nitrite, and protein concentrations.

PubMed

McCafferty, J B; Bradshaw, T A; Tate, S; Greening, A P; Innes, J A

2004-08-01

The effects of breathing pattern and inspired air conditions on the volume and content of exhaled breath condensate (EBC) were investigated. Total exhaled water (TEW), EBC volume, pH, nitrite and protein concentrations were measured in three groups of 10 healthy subjects breathing into a condenser at different target minute ventilations (Vm), tidal volumes (Vt), and inspired air conditions. The volumes of both TEW and EBC increased significantly with Vm. For Vm 7.5, 15 and 22.5 l/min, mean (SD) EBC was 627 (258) microl, 1019 (313) microl, and 1358 (364) microl, respectively (p<0.001) and TEW was 1879 (378) microl, 2986 (496) microl, and 4679 (700) microl, respectively (p<0.001). TEW was significantly higher than EBC, reflecting a condenser efficiency of 40% at a target Vm of 7.5 l/min which reduced to 29% at Vm 22.5 l/min. Lower Vt gave less TEW than higher Vt (26.6 v 30.7 microl/l, mean difference 4.1 (95% CI 2.6 to 5.6), p<0.001) and a smaller EBC volume (4.3 v 7.6 microl/l, mean difference 3.4 (95% CI 2.3 to 4.5), p<0.001). Cooler and drier inspired air yielded less water vapour and less breath condensate than standard conditions (p<0.05). Changes in the breathing pattern had no effect on EBC protein and nitrite concentrations and pH. These results show that condensate volume can be increased by using high Vt and increased Vm without compromising the dilution of the sample.

Occurrence of pesticides in rain and air in urban and agricultural areas of Mississippi, April-September 1995.

PubMed

Coupe, R H; Manning, M A; Foreman, W T; Goolsby, D A; Majewski, M S

2000-04-05

In April 1995, the US Geological Survey began a study to determine the occurrence and temporal distribution of 49 pesticides and pesticide metabolites in air and rain samples from an urban and an agricultural sampling site in Mississippi. The study was a joint effort between the National Water-Quality Assessment and the Toxic Substances Programs and was part of a larger study examining the occurrence and temporal distribution of pesticides in air and rain in the Mississippi River basin. Concurrent high-volume air and wet-only deposition samples were collected weekly. The air samplers consisted of a glass-fiber filter to collect particles and tandem polyurethane foam plugs to collect gas-phase pesticides. Every rain and air sample collected from the urban and agricultural sites had detectable levels of multiple pesticides. The magnitude of the total concentration was 5-10 times higher at the agricultural site as compared to the urban site. The pesticide with the highest concentration in rain at both sites was methyl parathion. The pesticide with the highest concentration in the air samples from the agricultural site was also methyl parathion, but from the urban site the highest concentration was diazinon followed closely by chlorpyrifos. More than two decades since p,p'-DDT was banned from use in the United States, p,p'-DDE, a metabolite of p,p'-DDT, was detected in every air sample collected from the agricultural site and in more than half of the air samples from the urban site.

Occurrence of pesticides in rain and air in urban and agricultural areas of Mississippi, April-September 1995

USGS Publications Warehouse

Coupe, R.H.; Manning, M.A.; Foreman, W.T.; Goolsby, D.A.; Majewski, M.S.

2000-01-01

In April 1995, the US Geological Survey began a study to determine the occurrence and temporal distribution of 49 pesticides and pesticide metabolites in air and rain samples from an urban and an agricultural sampling site in Mississippi. The study was a joint effort between the National Water-Quality Assessment and the Toxic Substances Programs and was part of a larger study examining the occurrence and temporal distribution of pesticides in air and rain in the Mississippi River basin. Concurrent high-volume air and wet-only deposition samples were collected weekly. The air samplers consisted of a glass-fiber filter to collect particles and tandem polyurethane foam plugs to collect gas-phase pesticides. Every rain and air sample collected from the urban and agricultural sites had detectable levels of multiple pesticides. The magnitude of the total concentration was 5-10 times higher at the agricultural site as compared to the urban site. The pesticide with the highest concentration in rain at both sites was methyl parathion. The pesticide with the highest concentration in the air samples from the agricultural site was also methyl parathion, but from the urban site the highest concentration was diazinon followed closely by chlorpyrifos. More than two decades since p,p'-DDT was banned from use in the United States, p,p'-DDE, a metabolite of p,p'-DDT, was detected in every air sample collected from the agricultural site and in more than half of the air samples from the urban site. Copyright (C) 2000 Elsevier Science B.V.

Aerosol Sampling: Comparison of Two Rotating Impactors for Field Droplet Sizing and Volumetric Measurements

DTIC Science & Technology

2009-01-01

the rotating impactors were measured via spectroscopy and microscopy. The rotary impactors were colocated with an isokinetic air sampler for a total...diameter, and the 90% diameter (DV10 and DV90; ASTM 2004). For each replication, an isokinetic air sampler and rotary sampler operated simultaneously in the...working area of the dispersion tunnel. The isokinetic sampler (StaplexH Model TFIA High Volume Air Sampler, The Staplex Company, Brooklyn, NY) was

Meteorological and operational aspects of 46 clear air turbulent sampling missions with an instrumented B-57B aircraft. Volume 2, appendix C: Turbulence missions

NASA Technical Reports Server (NTRS)

Waco, D. E.

1979-01-01

The results of 46 clear air turbulence (CAT) probing missions conducted with an extensively instrumented B-57B aircraft are summarized from a meteorological viewpoint in a two-volume technical memorandum. The missions were part of the NASA Langley Research Center's MAT (Measurement of Atmospheric Turbulence) program, which was conducted between March 1974, and September 1975, at altitudes ranging up to 15 km. Turbulence samples were obtained under diverse conditions including mountain waves, jet streams, upper level fronts and troughs, and low altitude mechanical and thermal turbulence. CAT was encountered on 20 flights comprising 77 data runs. In all, approximately 4335 km were flown in light turbulence, 1415 km in moderate turbulence, and 255 km in severe turbulence during the program.

Sensitive indoor air monitoring of formaldehyde and other carbonyl compounds using the 2,4-dinitrophenylhydrazine method.

PubMed

Sandner, F; Dott, W; Hollender, J

2001-03-01

The toxic potential of formaldehyde and other aliphatic/aromatic carbonyl compounds requires the determination of even low amounts of these compounds in indoor air. The existing DFG-method for workplace monitoring using adsorption at 2,4-dinitrophenylhydrazine (DNPH)-coated sorbents followed by HPLC-UV/DAD analysis of the extract was modified in order to decrease detection limits. The improvement included an increase in volume and rate of the air sampling, testing applicability of different adsorption materials and a decrease of the extraction volume of the hydrazones. 13 DNPH-derivatives could be separated well on a RP18-column followed by UV/DAD-detection at 365 nm. Recovery rates of 70-100% were determined (apart from acetone with 19%) using dynamically produced artifical carbonyl atmospheres. Detection limits of 0.05-0.4 microgram/m3 were reached by this method which are sufficient for indoor air monitoring.

Penguin lungs and air sacs: implications for baroprotection, oxygen stores and buoyancy.

PubMed

Ponganis, P J; St Leger, J; Scadeng, M

2015-03-01

The anatomy and volume of the penguin respiratory system contribute significantly to pulmonary baroprotection, the body O2 store, buoyancy and hence the overall diving physiology of penguins. Therefore, three-dimensional reconstructions from computerized tomographic (CT) scans of live penguins were utilized to measure lung volumes, air sac volumes, tracheobronchial volumes and total body volumes at different inflation pressures in three species with different dive capacities [Adélie (Pygoscelis adeliae), king (Aptenodytes patagonicus) and emperor (A. forsteri) penguins]. Lung volumes scaled to body mass according to published avian allometrics. Air sac volumes at 30 cm H2O (2.94 kPa) inflation pressure, the assumed maximum volume possible prior to deep dives, were two to three times allometric air sac predictions and also two to three times previously determined end-of-dive total air volumes. Although it is unknown whether penguins inhale to such high volumes prior to dives, these values were supported by (a) body density/buoyancy calculations, (b) prior air volume measurements in free-diving ducks and (c) previous suggestions that penguins may exhale air prior to the final portions of deep dives. Based upon air capillary volumes, parabronchial volumes and tracheobronchial volumes estimated from the measured lung/airway volumes and the only available morphometry study of a penguin lung, the presumed maximum air sac volumes resulted in air sac volume to air capillary/parabronchial/tracheobronchial volume ratios that were not large enough to prevent barotrauma to the non-collapsing, rigid air capillaries during the deepest dives of all three species, and during many routine dives of king and emperor penguins. We conclude that volume reduction of airways and lung air spaces, via compression, constriction or blood engorgement, must occur to provide pulmonary baroprotection at depth. It is also possible that relative air capillary and parabronchial volumes are smaller in these deeper-diving species than in the spheniscid penguin of the morphometry study. If penguins do inhale to this maximum air sac volume prior to their deepest dives, the magnitude and distribution of the body O2 store would change considerably. In emperor penguins, total body O2 would increase by 75%, and the respiratory fraction would increase from 33% to 61%. We emphasize that the maximum pre-dive respiratory air volume is still unknown in penguins. However, even lesser increases in air sac volume prior to a dive would still significantly increase the O2 store. More refined evaluations of the respiratory O2 store and baroprotective mechanisms in penguins await further investigation of species-specific lung morphometry, start-of-dive air volumes and body buoyancy, and the possibility of air exhalation during dives. © 2015. Published by The Company of Biologists Ltd.

Sampling and analysis of quaternary ammonium compounds (QACs) traces in indoor atmosphere.

PubMed

Vincent, Guillaume; Kopferschmitt-Kubler, Marie Christine; Mirabel, Philippe; Pauli, Gabrielle; Millet, Maurice

2007-10-01

Quaternary Ammonium Compounds (QACs) are widely found in disinfectants used in hospitals. Benzalkonium chloride (BAC) and didecyldimethylammonium chloride (DDAC) predominate in the disinfecting formulations. These compounds are strong irritants and can play a role in the induction of Occupational Asthma among the professionals of health and cleaning. In order to evaluate the potential health effect of these quaternary ammonium compounds to hospital employers, the development of an analytical method for their quantification in indoor air was developed. DDAC aerosols are trapped by adsorption on XAD-2 resin SKC tube. The air in hospital buildings was sampled using a constant debit Gillian pump at a flow of 1.0 l/min (+/-5%). Ion Chromatography (IC) was chosen for the analysis of DDAC especially for its high sensitivity and specificity. The Limit of Detection (LOD) by IC for DDAC is 0.56 mug/ml. Therefore the LOD of atmospheric DDAC is 28 microg/m(3) with an air volume of 100 l and a desorption volume of 5 ml. All DDAC air samples were lower than the LOD of the analytical method by IC. Under the standard conditions of use of the disinfecting solutions (Surfanios, Ampholysine Plus and Amphospray 41), the insignificant volatility of DDAC would not seem to be able to contaminate the indoor hospital atmosphere during the disinfection process. However, the DDAC can contaminate working atmospheres if it is put in suspension by aerosolisation.

Atmospheric CO2 Records from Sites in the Umweltbundesamt (UBA) Air Sampling Network (1972 - 1997)

DOE Data Explorer

Fricke, W. [Umweltbundesamt, Offenbach/Main, Germany; Wallasch, M. [Umweltbundesamt, Offenbach/Main, Germany; Uhse, Karin [Umweltbundesamt, Offenbach/Main, Germany; Schmidt, Martina [University of Heidelberg, Heidelberg, Germany; Levin, Ingeborg [University of Heidelberg, Heidelberg, Germany

1998-01-01

Air samples for the purpose of monitoring atmospheric CO2 were collected from five sites in the UBA air sampling network. Annual atmospheric CO2 concentrations at Brotjacklriegel rose from 331.63 parts per million by volume (ppmv) in 1972 to 353.12 ppmv in 1988. Because of the site's forest location, the monthly atmospheric CO2 record from Brotjacklriegel exhibits very large seasonal amplitude. This amplitude reached almost 40 ppmv in 1985. Minimum mixing ratios are recorded at Brotjacklriegel during July-September; maximum values, during November-March. CO2 concentrations at Deuselbach rose from 340.82 parts per million by volume (ppmv) in 1972 to 363.76 ppmv in 1989. The monthly atmospheric CO2 record from Deuselbach is influenced by local agricultural activities and photosynthetic depletion but does not exhibit the large seasonal amplitude observed at other UBA monitoring sites. Minimum monthly atmospheric CO2 mixing ratios at Deuselbach are typically observed in August but may appear as early as June. Maximum values are seen in the record for November-March. Atmospheric CO2 concentrations at Schauinsland rose from ~328 parts per million by volume (ppmv) in 1972 to ~365 ppmv in 1997. This represents a growth rate of approximately 1.5 ppmv per year. The Schauinsland site is considered the least contaminated of the UBA sites. CO2 concentrations at Waldhof rose from 346.82 parts per million by volume (ppmv) in 1972 to 372.09 ppmv in 1993. The Waldhof site is subject to pollution sources; consequently, the monthly atmospheric CO2 record exhibits a large seasonal amplitude. Atmospheric CO2 concentrations at Westerland rose from ~329 parts per million by volume (ppmv) in 1973 to ~364 ppmv in 1997. The atmospheric CO2 record from Westerland shows a seasonal pattern similar to other UBA sites; minimum values are recorded during July-September; maximum mixing ratios during November-March.

Sensitive ion detection device and method for analysis of compounds as vapors in gases

DOEpatents

Denton, M. Bonner; Sperline, Roger P.

2015-09-15

An ion mobility spectrometer (IMS) for the detection of trace gaseous molecular compounds dissolved or suspended in a carrier gas, particularly in ambient air, without preconcentration or the trapping of analyte particles. The IMS of the invention comprises an ionization volume of greater than 5 cm.sup.3 and preferably greater than 100 cm.sup.3. The larger size ionizers of this invention enable analysis of trace (<1 ppb) of sample compounds in the gas phase. To facilitate efficient ion motion through the large volume ionization and reaction regions of the IMS, an electric field gradient can be provided in the ionization region or in both the ionization and reaction regions. The systems can be implemented with radioactive ionization sources, corona discharge ion sources or ions can be formed by photoionization. In specific embodiments, particularly when the sample gas is ambient air, the sample gas is heater prior to entry into the instrument, the instrument is run at temperatures above ambient, and the instrument can be heated by contact with heated sample gas exiting the instrument.

Sensitive ion detection device and method for analysis of compounds as vapors in gases

DOEpatents

Denton, M. Bonner; Sperline, Roger P

2014-02-18

An ion mobility spectrometer (IMS) for the detection of trace gaseous molecular compounds dissolved or suspended in a carrier gas, particularly in ambient air, without preconcentration or the trapping of analyte particles. The IMS of the invention comprises an ionization volume of greater than 5 cm.sup.3 and preferably greater than 100 cm.sup.3. The larger size ionizers of this invention enable analysis of trace (<1 ppb) of sample compounds in the gas phase. To facilitate efficient ion motion through the large volume ionization and reaction regions of the IMS, an electric field gradient can be provided in the ionization region or in both the ionization and reaction regions. The systems can be implemented with radioactive ionization sources, corona discharge ion sources or ions can be formed by photoionization. In specific embodiments, particularly when the sample gas is ambient air, the sample gas is heater prior to entry into the instrument, the instrument is run at temperatures above ambient, and the instrument can be heated by contact with heated sample gas exiting the instrument.

The mutagenicity of indoor air particles in a residential pilot field study: Application and evaluation of new methodologies

NASA Astrophysics Data System (ADS)

Lewtas, Joellen; Goto, Sumio; Williams, Katherine; Chuang, Jane C.; Petersen, Bruce A.; Wilson, Nancy K.

The mutagenicity of indoor air paniculate matter has been measured in a pilot field study of homes in Columbus, Ohio during the 1984 winter. The study was conducted in eight all natural-gas homes and two all electric homes. Paniculate matter and semi-volatile organic compounds were collected indoors using a medium volume sampler. A micro-forward mutation bioassay employing Salmonella typhimurium strain TM 677 was used to quantify the mutagenicity in solvent extracts of microgram quantities of indoor air particles. The mutagenicity was quantified in terms of both mutation frequency per mg of organic matter extracted and per cubic meter of air sampled. The combustion source variables explored in this study included woodburning in fireplaces and cigarette smoking. Homes in which cigarette smoking occurred had the highest concentrations of mutagenicity per cubic meter of air. The average indoor air mutagenicity per cubic meter was highly correlated with the number of cigarettes smoked. When the separate sampling periods in each room were compared, the mutagenicity in the kitchen samples was the most highly correlated with the number of cigarettes smoked.

A multiresidue method by high performance liquid chromatography-based fractionation and gas chromatographic determination of trace levels of pesticides in air and water.

PubMed

Seiber, J N; Glotfelty, D E; Lucas, A D; McChesney, M M; Sagebiel, J C; Wehner, T A

1990-01-01

A multiresidue analytical method is described for pesticides, transformation products, and related toxicants based upon high performance liquid chromatographic (HPLC) fractionation of extracted residue on a Partisil silica gel normal phase column followed by selective-detector gas chromatographic (GC) determination of components in each fraction. The HPLC mobile phase gradient (hexane to methyl t-butyl ether) gave good chromatographic efficiency, resolution, reproducibility and recovery for 61 test compounds, and allowed for collection in four fractions spanning polarities from low polarity organochlorine compounds (fraction 1) to polar N-methylcarbamates and organophosphorus oxons (fraction 4). The multiresidue method was developed for use with air samples collected on XAD-4 and related trapping agents, and water samples extracted with methylene chloride. Detection limits estimated from spiking experiments were generally 0.3-1 ng/m3 for high-volume air samples, and 0.01-0.1 microgram/L for one-liter water samples. Applications were made to determination of pesticides in fogwater and air samples.

Atmospheric Concentrations of Persistent Organic Pollutants in the Southern Ocean

NASA Astrophysics Data System (ADS)

Vlahos, P.; Edson, J.; Cifuentes, A.; McGillis, W. R.; Zappa, C.

2008-12-01

Long-range transport of persistent organic pollutant (POPs) is a global concern. Remote regions such as the Southern Ocean are greatly under-sampled though critical components in understanding POPs cycling. Over 20 high-volume air samples were collected in the Southern Ocean aboard the RV Brown during the GASEX III experiment between Mar 05 to April 9 2008. The relatively stationary platform (51S,38W) enabled the collection of a unique atmospheric time series at this open ocean station. Air sampling was also conducted across transects from Punto Arenas, Chile and to Montevideo, Uruguay. Samples were collected using glass sleeves packed with poly-urethane foam plugs and C-18 resin in order to collect target organic pollutants (per-fluorinated compounds, currently and historically used pesticides) in this under-sampled region. Here we present POPs concentrations and trends over the sampled period and compare variations with air parcel back trajectories to establish potential origins of their long-range transport.

Calibration of polyurethane foam (PUF) disk passive air samplers for quantitative measurement of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs): factors influencing sampling rates.

PubMed

Hazrati, Sadegh; Harrad, Stuart

2007-03-01

PUF disk passive air samplers are increasingly employed for monitoring of POPs in ambient air. In order to utilize them as quantitative sampling devices, a calibration experiment was conducted. Time integrated indoor air concentrations of PCBs and PBDEs were obtained from a low volume air sampler operated over a 50 d period alongside the PUF disk samplers in the same office microenvironment. Passive sampling rates for the fully-sheltered sampler design employed in our research were determined for the 51 PCB and 7 PBDE congeners detected in all calibration samples. These values varied from 0.57 to 1.55 m3 d(-1) for individual PCBs and from 1.1 to 1.9 m3 d(-1) for PBDEs. These values are appreciably lower than those reported elsewhere for different PUF disk sampler designs (e.g. partially sheltered) employed under different conditions (e.g. in outdoor air), and derived using different calibration experiment configurations. This suggests that sampling rates derived for a specific sampler configuration deployed under specific environmental conditions, should not be extrapolated to different sampler configurations. Furthermore, our observation of variable congener-specific sampling rates (consistent with other studies), implies that more research is required in order to understand fully the factors that influence sampling rates. Analysis of wipe samples taken from the inside of the sampler housing, revealed evidence that the housing surface scavenges particle bound PBDEs.

Effects of breathing pattern and inspired air conditions on breath condensate volume, pH, nitrite, and protein concentrations

PubMed Central

McCafferty, J; Bradshaw, T; Tate, S; Greening, A; Innes, J

2004-01-01

Background: The effects of breathing pattern and inspired air conditions on the volume and content of exhaled breath condensate (EBC) were investigated. Methods: Total exhaled water (TEW), EBC volume, pH, nitrite and protein concentrations were measured in three groups of 10 healthy subjects breathing into a condenser at different target minute ventilations (Vm), tidal volumes (Vt), and inspired air conditions. Results: The volumes of both TEW and EBC increased significantly with Vm. For Vm 7.5, 15 and 22.5 l/min, mean (SD) EBC was 627 (258) µl, 1019 (313) µl, and 1358 (364) µl, respectively (p<0.001) and TEW was 1879 (378) µl, 2986 (496) µl, and 4679 (700) µl, respectively (p<0.001). TEW was significantly higher than EBC, reflecting a condenser efficiency of 40% at a target Vm of 7.5 l/min which reduced to 29% at Vm 22.5 l/min. Lower Vt gave less TEW than higher Vt (26.6 v 30.7 µl/l, mean difference 4.1 (95% CI 2.6 to 5.6), p<0.001) and a smaller EBC volume (4.3 v 7.6 µl/l, mean difference 3.4 (95% CI 2.3 to 4.5), p<0.001). Cooler and drier inspired air yielded less water vapour and less breath condensate than standard conditions (p<0.05). Changes in the breathing pattern had no effect on EBC protein and nitrite concentrations and pH. Conclusion: These results show that condensate volume can be increased by using high Vt and increased Vm without compromising the dilution of the sample. PMID:15282391

United States Air Force 611th Air Support Group/Civil Engineering Squadron, Elmendorf AFB, Alaska. Remedial investigation and feasibility study: Oliktok Point Radar Installation, Alaska. Volume 1. (Includes appendices a - b)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-04-15

This report presents the findings of Remedial Investigations and Feasibility Studies at sites located at the Oliktok Point radar installation in northern Alaska. The sites were characterized based on sampling and analyses conducted during Remedial Investigation activities performed during August and September 1993.

Apparatus for Sampling Surface Contamination

NASA Technical Reports Server (NTRS)

Wells, Mark

2008-01-01

An apparatus denoted a swab device has been developed as a convenient means of acquiring samples of contaminants from surfaces and suspending the samples in liquids. (Thereafter, the liquids can be dispensed, in controlled volumes, into scientific instruments for analysis of the contaminants.) The swab device is designed so as not to introduce additional contamination and to facilitate, simplify, and systematize the dispensing of controlled volumes of liquid into analytical instruments. The swab device is a single apparatus into which are combined all the equipment and materials needed for sampling surface contamination. The swab device contains disposable components stacked together on a nondisposable dispensing head. One of the disposable components is a supply cartridge holding a sufficient volume of liquid for one complete set of samples. (The liquid could be clean water or another suitable solvent, depending on the application.) This supply of liquid is sealed by Luer valves. At the beginning of a sampling process, the user tears open a sealed bag containing the supply cartridge. A tip on the nondisposable dispensing head is engaged with a Luer valve on one end of the supply cartridge and rotated, locking the supply cartridge on the dispensing head and opening the valve. The swab tip includes a fabric swab that is wiped across the surface of interest to acquire a sample. A sealed bag containing a disposable dispensing tip is then opened, and the swab tip is pushed into the dispensing tip until seated. The dispensing head contains a piston that passes through a spring-loaded lip seal. The air volume displaced by this piston forces the liquid out of the supply cartridge, over the swab, and into the dispensing tip. The piston is manually cycled to enforce oscillation of the air volume and thereby to cause water to flow to wash contaminants from the swab and cause the resulting liquid suspension of contaminants to flow into the dispensing tip. After several cycles to ensure adequate mixing, liquid containing the suspended contaminant sample is dispensed. The disposable components are then removed from the dispensing head, which may then be reused with a fresh set of disposable components.

Assessment of fluid distribution and flow properties in two phase fluid flow using X-ray CT technology

NASA Astrophysics Data System (ADS)

Jiang, Lanlan; Wu, Bohao; Li, Xingbo; Wang, Sijia; Wang, Dayong; Zhou, Xinhuan; Zhang, Yi

2018-04-01

To study on microscale distribution of CO2 and brine during two-phase flow is crucial for understanding the trapping mechanisms of CO2 storage. In this study, CO2-brine flow experiments in porous media were conducted using X-ray computed tomography. The porous media were packed with glass beads. The pore structure (porosity/tortuosity) and flow properties at different flow rates and flow fractions were investigated. The results showed that porosity of the packed beads differed at different position as a result of heterogeneity. The CO2 saturation is higher at low injection flow rates and high CO2 fractions. CO2 distribution at the pore scale was also visualized. ∅ Porosity of porous media CT brine_ sat grey value of sample saturated with brine CT dry grey value of sample saturated with air CT brine grey value of pure brine CT air grey value of pure air CT flow grey values of sample with two fluids occupying the pore space {CT}_{CO_2_ sat} grey value of sample saturated with CO2 {f}_{CO_2}({S}_{CO_2}) CO2 fraction {q}_{CO_2} the volume flow rate for CO2 q brine the volume flow rate for brine L Thickness of the porous media, mm L e a bundle of capillaries of equal length, mm τ Tortuosity, calculated from L e / L.

Installation Restoration Program. Remedial Investigation Report. Volk Field Air National Guard, Camp Douglas, Wisconsin. Volume 1.

DTIC Science & Technology

1993-09-01

Surface Area Contacted Per Event SB soil boring Sb Antimony SD sediment sample SDG Sample Delivery Group SDWA Safe Drinking Water Act Se Selenium sec second...and were laid out using a Brunton compass and measuring tape. The station locations were gridded at intervals of 25 feet. Measurements indicating the

Irreversible sorption of trace concentrations of perfluorocarboxylic acids to fiber filters used for air sampling

NASA Astrophysics Data System (ADS)

Arp, Hans Peter H.; Goss, Kai-Uwe

Due to the apparent environmental omnipresence of perfluorocarboxylic acids (PFAs), an increasing number of researchers are investigating their ambient particle- and gas-phase concentrations. Typically this is done using a high-volume air sampler equipped with Quartz Fiber Filters (QFFs) or Glass Fiber Filters (GFFs) to sample the particle-bound PFAs and downstream sorbents to sample the gas-phase PFAs. This study reports that at trace, ambient concentrations gas-phase PFAs sorb to QFFs and GFFs irreversibly and hardly pass through these filters to the downstream sorbents. As a consequence, it is not possible to distinguish between particle- and gas-phase concentrations, or to distinguish concentrations on different particle size fractions, unless precautions are taken. Failure to take such precautions could have already caused reported data to be misinterpreted. Here it is also reported that deactivating QFFs and GFFs with a silylating agent renders them suitable for sampling PFAs. Based on the presented study, a series of recommendations for air-sampling PFAs are provided.

Near-infrared spectroscopy (NIRS) as a tool to monitor exhaust air from poultry operations.

PubMed

Druckenmüller, Katharina; Günther, Klaus; Elbers, Gereon

2018-07-15

Intensive poultry operation systems emit a considerable volume of inorganic and organic matter in the surrounding environment. Monitoring cleaning properties of exhaust air cleaning systems and to detect small but significant changes in emission characteristics during a fattening cycle is important for both emission and fattening process control. In the present study, we evaluated the potential of near-infrared spectroscopy (NIRS) combined with chemometric techniques as a monitoring tool of exhaust air from poultry operation systems. To generate a high-quality data set for evaluation, the exhaust air of two poultry houses was sampled by applying state-of-the-art filter sampling protocols. The two stables were identical except for one crucial difference, the presence or absence of an exhaust air cleaning system. In total, twenty-one exhaust air samples were collected at the two sites to monitor spectral differences caused by the cleaning device, and to follow changes in exhaust air characteristics during a fattening period. The total dust load was analyzed by gravimetric determination and included as a response variable in multivariate data analysis. The filter samples were directly measured with NIR spectroscopy. Principal component analysis (PCA), linear discriminant analysis (LDA), and factor analysis (FA) were effective in classifying the NIR exhaust air spectra according to fattening day and origin. The results indicate that the dust load and the composition of exhaust air (inorganic or organic matter) substantially influence the NIR spectral patterns. In conclusion, NIR spectroscopy as a tool is a promising and very rapid way to detect differences between exhaust air samples based on still not clearly defined circumstances triggered during a fattening period and the availability of an exhaust air cleaning system. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Measurement of formaldehyde in clean air

NASA Astrophysics Data System (ADS)

Neitzert, Volker; Seiler, Wolfgang

1981-01-01

A method for the measurement of small amounts of formaldehyde in air has been developed. The method is based on the derivatization of HCHO with 2.4-Dinitrophenylhydrazine, forming 2.4-Dinitrophenylhydrazone, measured with GC-ECD-technique. HCHO is preconcentrated using a cryogenic sampling technique. The detection limit is 0.05 ppbv for a sampling volume of 200 liter. The method has been applied for measurements in continental and marine air masses showing HCHO mixing ratios of 0.4 - 5.0 ppbv and 0.2 - 1.0 ppbv, respectively. HCHO mixing ratios show diurnal variations with maximum values during the early afternoon and minimum values during the early morning. In continental air, HCHO mixing ratios are positively correlated with CO and SO2, indicating anthropogenic HCHO sources which are estimated to be 6-11 × 1012g/year-1 on a global scale.

Cost-Effective, Ultra-Sensitive Groundwater Monitoring for Site Remediation and Management

DTIC Science & Technology

2015-08-01

Micrometer ml Milliliter MS Mass Spectrometry MW Molecular Weight MΩ Mega-ohm NAS Naval Air Station 6 NASNI Naval Air Station North Island...feasibility studies. ..........42 Table 5-2 Compounds screened in the laboratory for IS2 sampling ......................................44 Table 5-3 Mass ...concentration data is derived directly from the mass of analyte recovered from the sorbent cartridge and the known volume of water processed. This

Love Canal Emergency Declaration Area habitability study. Volume 2. Air assessment: indicator chemicals. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Environmental studies were conducted to provide data that could be used by the Commissioner of Health for the State of New York in determining whether the Emergency Declaration Area (EDA) surrounding the Love Canal hazardous-waste site is habitable. An air assessment was conducted for Love Canal Indicator Chemicals. Homes throughout the EDA were sampled using the Trace Atmospheric Gas Analyzer Model 6000E.

46 CFR Appendix D to Subpart C to... - Sampling and Analytical Methods for Benzene Monitoring-Measurement Procedures

Code of Federal Regulations, 2010 CFR

2010-10-01

... chromatograph. Detection limit: 0.04 ppm. Recommended air volume and sampling rate: 10 liter at 0.2 liter/min. 1... tube must be less than one inch of mercury at a flow rate of one liter per minute. 3.3. Gas... passed through any hose or tubing before entering the charcoal tube. 5.3.5. A sample size of 10 liters is...

46 CFR Appendix D to Subpart C to... - Sampling and Analytical Methods for Benzene Monitoring-Measurement Procedures

Code of Federal Regulations, 2011 CFR

2011-10-01

... chromatograph. Detection limit: 0.04 ppm. Recommended air volume and sampling rate: 10 liter at 0.2 liter/min. 1... tube must be less than one inch of mercury at a flow rate of one liter per minute. 3.3. Gas... passed through any hose or tubing before entering the charcoal tube. 5.3.5. A sample size of 10 liters is...

Evaluation of analytical methodology for hydrocarbons in high pressure air and nitrogen systems. [evaluation of methodology

NASA Technical Reports Server (NTRS)

1977-01-01

Samples of liquid oxygen, high pressure nitrogen, low pressure nitrogen, and missile grade air were studied to determine the hydrocarbon concentrations. Concentration of the samples was achieved by adsorption on a molecular sieve and activated charcoal. The trapped hydrocarbons were then desorbed and transferred to an analytical column in a gas chromatograph. The sensitivity of the method depends on the volume of gas passed through the adsorbent tubes. The value of the method was verified through recoverability and reproducibility studies. The use of this method enables LOX, GN2, and missile grade air systems to be routinely monitored to determine low level increases in specific hydrocarbon concentration that could lead to potentially hazardous conditions.

Ambient air concentrations of PCDDs, PCDFs, coplanar PCBs, and PAHs at the Mississippi Sandhill Crane National Wildlife Refuge, Jackson County, Mississippi

USGS Publications Warehouse

White, D.H.; Hardy, J.W.

1994-01-01

Our objective was to determine the levels of selected airborne contaminants in ambient air at the Mississippi Sandhill Crane National Wildlife Refuge, Mississippi, that might be affecting the health of endangered cranes living there. Two high-volume air samplers were operated at separate locations on the Refuge during May?September 1991. The sampling media were micro-quartz filters in combination with polyurethane foam plugs. Composite bimonthly samples from each station were analyzed for polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), coplanar polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). Overall, residue concentrations were low. The toxic PCDD isomer 2,3,7,8-tetra-CDD was not detected, nor was penta-CDD. There was no difference (P>0.05) in residue concentrations between stations or over time and meteorological parameters were not correlated with residue concentrations. Because contaminant levels and patterns may differ seasonally, we recommend that air samples collected during winter months also be analyzed for these same chemical groups.

Air quality during demolition and recovery activities in post-Katrina New Orleans.

PubMed

Ravikrishna, Raghunathan; Lee, Han-Woong; Mbuligwe, Stephen; Valsaraj, K T; Pardue, John H

2010-07-01

Air samples were collected during demolition and cleanup operations in the Lakeview district of New Orleans, Louisiana, USA, in late 2005 during the period immediately after Hurricane Katrina. Three different high-volume air samples were collected around waste collection areas that were created to temporarily hold the debris from the cleanup of residential properties in the area. Particulate concentrations were elevated and included crystalline fibers associated with asbestos. Metal concentrations on particulate matter resembled those measured in sediments deposited by floodwaters with the exception of Ba, which was elevated at all three locations. The highest organic contaminant concentration measured on particulates was the pesticide Ziram (Zinc, bis[diethylcarbamodithioato-S,S']-, [T-4]-) at 2,200 microg/g of particulate matter during sampling period 2. Ziram is used in latex paint, adhesives, caulking, and wallboard as a preservative. Fungal isolates developed from particulate air samples included species associated with disease including Aspergillus and Penicillium species. These data represent the most comprehensive assessment of demolition activities during the period immediately after Hurricane Katrina. Copyright (c) 2010 SETAC.

Detection of cocaine in cargo containers by high-volume vapor sampling: field test at Port of Miami

NASA Astrophysics Data System (ADS)

Neudorfl, Pavel; Hupe, Michael; Pilon, Pierre; Lawrence, Andre H.; Drolet, Gerry; Su, Chih-Wu; Rigdon, Stephen W.; Kunz, Terry D.; Ulwick, Syd; Hoglund, David E.; Wingo, Jeff J.; Demirgian, Jack C.; Shier, Patrick

1997-02-01

The use of marine containers is a well known smuggling method for large shipments of drugs. Such containers present an ideal method of smuggling as the examination method is time consuming, difficult and expensive for the importing community. At present, various methods are being studied for screening containers which would allow to rapidly distinguish between innocent and suspicious cargo. Air sampling is one such method. Air is withdrawn for the inside of containers and analyzed for telltale vapors uniquely associated with the drug. The attractive feature of the technique is that the containers could be sampled without destuffing and opening, since air could be conveniently withdrawn via ventilation ducts. In the present paper, the development of air sampling methodology for the detection of cocaine hydrochloride will be discussed, and the results from a recent field test will be presented. The results indicated that vapors of cocaine and its decomposition product, ecgonidine methyl ester, could serve as sensitive indicators of the presence of the drug in the containers.

Development of size-selective sampling of Bacillus anthracis surrogate spores from simulated building air intake mixtures for analysis via laser-induced breakdown spectroscopy.

PubMed

Gibb-Snyder, Emily; Gullett, Brian; Ryan, Shawn; Oudejans, Lukas; Touati, Abderrahmane

2006-08-01

Size-selective sampling of Bacillus anthracis surrogate spores from realistic, common aerosol mixtures was developed for analysis by laser-induced breakdown spectroscopy (LIBS). A two-stage impactor was found to be the preferential sampling technique for LIBS analysis because it was able to concentrate the spores in the mixtures while decreasing the collection of potentially interfering aerosols. Three common spore/aerosol scenarios were evaluated, diesel truck exhaust (to simulate a truck running outside of a building air intake), urban outdoor aerosol (to simulate common building air), and finally a protein aerosol (to simulate either an agent mixture (ricin/anthrax) or a contaminated anthrax sample). Two statistical methods, linear correlation and principal component analysis, were assessed for differentiation of surrogate spore spectra from other common aerosols. Criteria for determining percentages of false positives and false negatives via correlation analysis were evaluated. A single laser shot analysis of approximately 4 percent of the spores in a mixture of 0.75 m(3) urban outdoor air doped with approximately 1.1 x 10(5) spores resulted in a 0.04 proportion of false negatives. For that same sample volume of urban air without spores, the proportion of false positives was 0.08.

Atmospheric particulate measurements in Norfolk, Virginia

NASA Technical Reports Server (NTRS)

Storey, R. W., Jr.; Sentell, R. J.; Woods, D. C.; Smith, J. R.; Harris, F. S., Jr.

1975-01-01

Characterization of atmospheric particulates was conducted at a site near the center of Norfolk, Virginia. Air quality was measured in terms of atmospheric mass loading, particle size distribution, and particulate elemental composition for a period of 2 weeks. The objectives of this study were (1) to establish a mean level of air quality and deviations about this mean, (2) to ascertain diurnal changes or special events in air quality, and (3) to evaluate instrumentation and sampling schedules. Simultaneous measurements were made with the following instruments: a quartz crystal microbalance particulate monitor, a light-scattering multirange particle counter, a high-volume air sampler, and polycarbonate membrane filters. To assess the impact of meteorological conditions on air quality variations, continuous data on temperature, relative humidity, wind speed, and wind direction were recorded. Particulate elemental composition was obtained from neutron activation and scanning electron microscopy analyses of polycarbonate membrane filter samples. The measured average mass loading agrees reasonably well with the mass loadings determined by the Virginia State Air Pollution Control Board. There are consistent diurnal increases in atmospheric mass loading in the early morning and a sample time resolution of 1/2 hour seems necessary to detect most of the significant events.

Biomonitoring polycyclic aromatic hydrocarbons by Salix matsudana leaves: A comparison with the relevant air content and evaluation of environmental parameter effects

NASA Astrophysics Data System (ADS)

Zhao, Xiangai; He, Miao; Shang, Haibo; Yu, Hongling; Wang, Hao; Li, Huijie; Piao, Jingyi; Quinto, Maurizio; Li, Donghao

2018-05-01

Studies on seasonal distribution characteristics of polycyclic aromatic hydrocarbons (PAHs) in Salix matsudana leaves covering its annual life cycle were carried out in order to evaluate plant leaf response sensitivity to air pollution. Salix matsudana leaves were collected throughout different development phases of plant leaf inclusive of bud break to fallen leaves, covering from spring (May) to autumn (November). Simultaneously, particle and gas samples were collected using a high volume air sampler. Seven different PAHs were determined simultaneously in these samples. The temperature dependence of the partitioning of PAHs in air and plant leaves was investigated and the results were incorporated into a mathematical model. The measured plant/air partition coefficients have been found to be exponentially proportional to the reciprocal temperature, in agreement with theoretical expectations. Furthermore, in order to define the influence of different parameters on PAH adsorption on plant leaves, area and lipid leaf content were also measured. Results demonstrated that temperature plays a very important role in PAHs partitioning and that this value should be carefully considered during sampling, in order to obtain the best correlation between PAHs concentration in air and leaves.

Innovations in air sampling to detect plant pathogens

PubMed Central

West, JS; Kimber, RBE

2015-01-01

Many innovations in the development and use of air sampling devices have occurred in plant pathology since the first description of the Hirst spore trap. These include improvements in capture efficiency at relatively high air-volume collection rates, methods to enhance the ease of sample processing with downstream diagnostic methods and even full automation of sampling, diagnosis and wireless reporting of results. Other innovations have been to mount air samplers on mobile platforms such as UAVs and ground vehicles to allow sampling at different altitudes and locations in a short space of time to identify potential sources and population structure. Geographical Information Systems and the application to a network of samplers can allow a greater prediction of airborne inoculum and dispersal dynamics. This field of technology is now developing quickly as novel diagnostic methods allow increasingly rapid and accurate quantifications of airborne species and genetic traits. Sampling and interpretation of results, particularly action-thresholds, is improved by understanding components of air dispersal and dilution processes and can add greater precision in the application of crop protection products as part of integrated pest and disease management decisions. The applications of air samplers are likely to increase, with much greater adoption by growers or industry support workers to aid in crop protection decisions. The same devices are likely to improve information available for detection of allergens causing hay fever and asthma or provide valuable metadata for regional plant disease dynamics. PMID:25745191

Real-time and integrated measurement of potential human exposure to particle-bound polycyclic aromatic hydrocarbons (PAHs) from aircraft exhaust.

PubMed Central

Childers, J W; Witherspoon, C L; Smith, L B; Pleil, J D

2000-01-01

We used real-time monitors and low-volume air samplers to measure the potential human exposure to airborne polycyclic aromatic hydrocarbon (PAH) concentrations during various flight-related and ground-support activities of C-130H aircraft at an Air National Guard base. We used three types of photoelectric aerosol sensors (PASs) to measure real-time concentrations of particle-bound PAHs in a break room, downwind from a C-130H aircraft during a four-engine run-up test, in a maintenance hangar, in a C-130H aircraft cargo bay during cargo-drop training, downwind from aerospace ground equipment (AGE), and in a C-130H aircraft cargo bay during engine running on/off (ERO) loading and backup exercises. Two low-volume air samplers were collocated with the real-time monitors for all monitoring events except those in the break room and during in-flight activities. Total PAH concentrations in the integrated-air samples followed a general trend: downwind from two AGE units > ERO-loading exercise > four-engine run-up test > maintenance hangar during taxi and takeoff > background measurements in maintenance hangar. Each PAH profile was dominated by naphthalene, the alkyl-substituted naphthalenes, and other PAHs expected to be in the vapor phase. We also found particle-bound PAHs, such as fluoranthene, pyrene, and benzo[a]pyrene in some of the sample extracts. During flight-related exercises, total PAH concentrations in the integrated-air samples were 10-25 times higher than those commonly found in ambient air. Real-time monitor mean responses generally followed the integrated-air sample trends. These monitors provided a semiquantitative temporal profile of ambient PAH concentrations and showed that PAH concentrations can fluctuate rapidly from a baseline level < 20 to > 4,000 ng/m(3) during flight-related activities. Small handheld models of the PAS monitors exhibited potential for assessing incidental personal exposure to particle-bound PAHs in engine exhaust and for serving as a real-time dosimeter to indicate when respiratory protection is advisable. PMID:11017890

Improved aqueous scrubber for collection of soluble atmospheric trace gases

NASA Technical Reports Server (NTRS)

Cofer, W. R., III; Talbot, R. W.; Collins, V. G.

1985-01-01

A new concentration technique for the extraction and enrichment of water-soluble atmospheric trace gases has been developed. The gas scrubbing technique efficiently extracts soluble gases from a large volume flow rate of air sample into a small volume of refluxed trapping solution. The gas scrubber utilizes a small nebulizing nozzle that mixes the incoming air with an aqueous extracting solution to form an air/droplet mist. The mist provides excellent interfacial surface areas for mass transfer. The resulting mist sprays upward through the reaction chamber until it impinges upon a hydrophobic membrane that virtually blocks the passage of droplets but offers little resistance to the existing gas flow. Droplets containing the scrubbed gases coalesce on the membrane and drip back into the reservoir for further refluxing. After a suitable concentration period, the extracting solution containing the analyte can be withdrawn for analysis. The nebulization-reflex concentration technique is more efficient (maximum flow of gas through the minimum volume of extractant) than conventional bubbler/impinger gas extraction techniques and is offered as an alternative method.

Organic Nitrates: A Complex Family of Atmospheric Trace Constituents

NASA Astrophysics Data System (ADS)

Ballschmiter, K.; Fischer, R. G.; Grünert, A.; Kastler, J.; Schneider, M.; Woidich, S.

2003-04-01

Biogenic and geogenic hydrocarbons are the precursors of organic nitrates that are formed as tropospheric photo-oxidation products in the presence of NOx. Air chemistry leads to a very complex pattern of nitric acid esters: alkyl nitrates, aryl-alkyl nitrates, and bifunctional nitrates like alkyl dinitrates, hydroxy alkyl nitrates and carbonyl alkyl nitrates. We have analyzed the pattern of organic nitrates in air samples after adsorption/thermal desorption (low volume sampling-LVS) or adsorption/solvent desorption (high volume sampling-HVS) by capillary gas chromatography with electron capture (ECD) and mass spectrometric detection (MSD) using air aliquotes of 100 up to 3000 liters on column. The complexity of the organic nitrates found in air requires a group pre-separation by normal phase liquid chromatography. A detection limit per compound of 0.005 ppt(v) is achieved by our approach. We have synthesized a broad spectrum of organic nitrates as reference compounds. Air samples were taken from central Europe, the US West (Utah, Nevada, California), and the North- and South Atlantic including Antarctica. Levels and patterns of the regional and global occurrence of the various groups of C1-C12 organic nitrates including dinitrates and hydroxy nitrates and nitrates of isoprene (2-methylbutadiene) are presented. Werner G., J. Kastler, R. Looser, K. Ballschmiter: "Organic nitrates of isoprene as atmospheric trace compounds" Angewandte Chemie - International Edition (1999) 38: 1634-1637. Woidich S., O. Froescheis, O. Luxenhofer, K. Ballschmiter: "EI- and NCI-mass spectrometry of arylalkyl nitrates and their occurrence in urban air" Fresenius J. Anal. Chem. (1999) 364 : 91-99. Kastler, J; Jarman, W; Ballschmiter, K.: "Multifunctional organic nitrates as constituents in European and US urban photo-smog" Fresenius J. Anal. Chem. (2000) 368:244-249. Schneider M., K. Ballschmiter: "C3-C14 alkyl nitrates in remote South Atlantic air" Chemosphere (1999) 38: 233-244. Fischer, R G; Kastler, J; Ballschmiter, K.: "Levels and pattern of alkyl nitrates, multifunctional alkyl nitrates, and halocarbons in the air over the Atlantic Ocean" J. Geophys. Research (2000) 105:14473-14494. Fischer R.G. , R. Weller, H.-W. Jacobi, K. Ballschmiter: "Levels and patterns of volatile organic nitrates and halocarbons in the air at Neumayer Station (70°), Antarctic" Chemosphere (2002) 48:981-992

An air-pressure-free elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis

NASA Astrophysics Data System (ADS)

Jung, Wooseok; Barrett, Matthew; Brooks, Carla; Rivera, Andrew; Birdsell, Dawn N.; Wagner, David M.; Zenhausern, Frederic

2015-12-01

We present a new elastomeric valve for integrated nucleic acid analysis by capillary electrophoresis. The valve functions include metering to capture a designated volume of biological sample into a polymerase chain reaction (PCR) chamber, sealing to preserve the sample during PCR cycling, and transfer of the PCR-products and on-chip formamide post-processing for the analysis of DNA fragments by capillary gel electrophoresis. This new valve differs from prior art polydimethylsiloxane (PDMS) valves in that the valve is not actuated externally by air-pressure or vacuum so that it simplifies a DNA analysis system by eliminating the need for an air-pressure or vacuum source, and off-cartridge solenoid valves, control circuit boards and software. Instead, the new valve is actuated by a thermal cycling peltier assembly integrated within the hardware instrument that tightly comes in contact with a microfluidic cartridge for thermal activation during PCR, so that it spontaneously closes the valve without an additional actuator system. The valve has bumps in the designated locations so that it has a self-alignment that does not require precise alignment of a valve actuator. Moreover, the thickness of the new valve is around 600 μm with an additional bump height of 400 μm so that it is easy to handle and very feasible to fabricate by injection molding compared to other PDMS valves whose thicknesses are around 30-100 μm. The new valve provided over 95% of metering performance in filling the fixed volume of the PCR chamber, preserved over 97% of the sample volume during PCR, and showed very comparable capillary electrophoresis peak heights to the benchtop assay tube controls with very consistent transfer volume of the PCR-product and on-chip formamide. The new valve can perform a core function for integrated nucleic acid analysis by capillary electrophoresis.

Converting Constant Volume, Multizone Air Handling Systems to Energy Efficient Variable Air Volume Multizone Systems

DTIC Science & Technology

2017-10-26

1 FINAL REPORT Converting Constant Volume, Multizone Air Handling Systems to Energy Efficient Variable Air Volume Multizone...Systems Energy and Water Projects Project Number: EW-201152 ERDC-CERL 26 October 2017 2 TABLE OF CONTENTS ACKNOWLEDGEMENTS...16 3.2.1 Energy Usage (Quantitative

United States Air Force 611th Air Support Group/Civil Engineering Squadron Elmendorf AFB, Alaska. Remedial investigation and feasibility study. Barter Island Radar Installation, Alaska. Volume 1 (includes appendices a through c). Revision 1. Final report, January 1995-January 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karmi, S.; Madden, J.; Borsetti, R.

1996-01-05

This report presents the findings of Remedial Investigations and Feasibility Studies at sites located at the Barter Island radar installation in northern Alaska. The sites were characterized based on sampling and analyses conducted during Remedial Investigation activities performed during August and September 1993.

Modeling Airborne Beryllium Concentrations From Open Air Dynamic Testing

NASA Astrophysics Data System (ADS)

Becker, N. M.

2003-12-01

A heightened awareness of airborne beryllium contamination from industrial activities was reestablished during the late 1980's and early 1990's when it became recognized that Chronic Beryllium Disease (CBD) had not been eradicated, and that the Occupational Health and Safety Administration standards for occupational air exposure to beryllium may not be sufficiently protective. This was in response to the observed CBD increase in multiple industrial settings where beryllium was manufactured and/or machined, thus producing beryllium particulates which are then available for redistribution by airborne transport. Sampling and modeling design activities were expanded at Los Alamos National Laboratory in New Mexico to evaluate potential airborne beryllium exposure to workers who might be exposed during dynamic testing activities associated with nuclear weapons Stockpile Stewardship. Herein is presented the results of multiple types of collected air measurements that were designed to characterize the production and dispersion of beryllium used in components whose performance is evaluated during high explosive detonation at open air firing sites. Data from fallout, high volume air, medium volume air, adhesive film, particle size impactor, and fine-particulate counting techniques will be presented, integrated, and applied in dispersion modeling to assess potential onsite and offsite personal exposures resulting from dynamic testing activities involving beryllium.

USAF/SCEEE (United States Air Force/Southeastern Center for Electrical Engineering Education) Research Initiation Program Research Reports. Volume 1.

DTIC Science & Technology

1985-03-01

comparison of samples would be difficult. (5) A restrictive random sample allows the sample to be irregularly spaced throughout the auxiliary variable space ...looking or downward-looking probes and the very low background radiation from space contribute to high signal-to-noise ratio and allow the...sunshine and earthshine, chemiluminescent processes, and radiation to space , in addition to collisional processes, determine the vibrational

Technical Review of the Laboratory Biosphere Closed Ecological System Facility

NASA Astrophysics Data System (ADS)

Dempster, W.; van Thillo, M.; Alling, A.; Allen, J.; Silverstone, S.; Nelson, M.

The "Laboratory Biosphere", a new closed ecological system facility in Santa Fe, New Mexico (USA) has been constructed and became operational in May 2002. Built and operated by the Global Ecotechnics consortium (Biosphere Technologies and Biosphere Foundation with Biospheric Design Inc., and the Institute of Ecotechnics), the research apparatus for intensive crop growth, biogeochemical cycle dynamics and recycling of inedible crop biomass comprises a sealed cylindrical steel chamber and attached variable volume chamber (lung) to prevent pressures caused by the expansion and contraction of the contained air. The cylindrical growing chamber is 3.7m (12 feet) long and 3.7m (12 foot) diameter, giving an internal volume of 34 m3 (1200 ft 3 ). The two crop growth beds cover 5.5 m2, with a soil depth of 0.3m (12 inches), with 12 x 1000 watt high-pressure sodium lights capable of variable lighting of 40-70 mol per m2 per day. A small soil bed reactor in the chamber can be activated to help with metabolism of chamber trace gases. The volume of the attached variable volume chamber (lung) can range between 0-11 m3 (0-400 ft 3 ). Evapotranspired and soil leachate water are collected, combined and recycled to water the planting beds. Sampling ports enable testing of water quality of leachate, condensate and irrigation water. Visual inspection windows provide views of the entire interior and growing beds. The chamber is also outfitted with an airlock to minimize air exchange when people enter and work in the chamber. Continuous sensors include atmospheric CO2 and oxygen, temperature, humidity, soil moisture, light level and water levels in reservoirs. Both "sniffer" (air ports) and "sipper" (water ports) will enable collection of water or air samples for detailed analysis. This paper reports on the development of this new soil-based bioregenerative life support closed system apparatus and its technical challenges and capabilities.

Optimizing detection of noble gas emission at a former UNE site: sample strategy, collection, and analysis

NASA Astrophysics Data System (ADS)

Kirkham, R.; Olsen, K.; Hayes, J. C.; Emer, D. F.

2013-12-01

Underground nuclear tests may be first detected by seismic or air samplers operated by the CTBTO (Comprehensive Nuclear-Test-Ban Treaty Organization). After initial detection of a suspicious event, member nations may call for an On-Site Inspection (OSI) that in part, will sample for localized releases of radioactive noble gases and particles. Although much of the commercially available equipment and methods used for surface and subsurface environmental sampling of gases can be used for an OSI scenario, on-site sampling conditions, required sampling volumes and establishment of background concentrations of noble gases require development of specialized methodologies. To facilitate development of sampling equipment and methodologies that address OSI sampling volume and detection objectives, and to collect information required for model development, a field test site was created at a former underground nuclear explosion site located in welded volcanic tuff. A mixture of SF-6, Xe127 and Ar37 was metered into 4400 m3 of air as it was injected into the top region of the UNE cavity. These tracers were expected to move towards the surface primarily in response to barometric pumping or through delayed cavity pressurization (accelerated transport to minimize source decay time). Sampling approaches compared during the field exercise included sampling at the soil surface, inside surface fractures, and at soil vapor extraction points at depths down to 2 m. Effectiveness of various sampling approaches and the results of tracer gas measurements will be presented.

Atmospheric CO2 Records from Sites in the Atmospheric Environment Service Air Sampling Network (1975 and 1994)

DOE Data Explorer

Trivett, N. B.A. [Atmospheric Environment Service, Downsview, Ontario, Canada; Hudec, V. C. [Atmospheric Environment Service, Downsview, Ontario, Canada; Wong, C. S. [Marine Carbon Research Centre, Institute of Ocean Sciences, Sidney, British Columbia, Canada

1997-01-01

From the mid-1970s through the mid-1990s, air samples were collected for the purposes of monitoring atmospheric CO2 from four sites in the AES air sampling network. Air samples were collected approximately once per week, between 12:00 and 16:00 local time, in a pair of evacuated 2-L thick-wall borosilicate glass flasks. Samples were collected under preferred conditions of wind speed and direction (i.e., upwind of the main station and when winds are strong and steady). The flasks were evacuated to pressures of ~1 × 10-4 mbar or 0.01 Pa prior to being sent to the stations. The airwas not dried during sample collection. The flask data from Alert show an increase in the annual atmospheric CO2 concentration from 341.35 parts per million by volume (ppmv) in 1981 to 357.21 ppmv in 1991. For Cape St. James, Trivett and Higuchi (1989) reported that the mean annual rate of increase, obtained from the slope of a least-squares regression line through the annual averages, was 1.43 ppmv per year. In August 1992, the weather station at Cape St. James was automated; as a result, the flask sampling program was discontinued at this site. Estevan Point, on the West Coast of Vancouver Island, was chosen as a replacement station. Sampling at Estevan Point started in 1992; thus, the monthly and annual CO2record from Estevan Point is too short to show any long-term trends. The sampling site at Sable Island, off the coast of Nova Scotia, was established in 1975. The flask data from Sable Island show an increase in the annual atmospheric CO2 concentration from 334.49 parts per million by volume (ppmv) in 1977 (the first full year of data) to 356.02 ppmv in 1990. For Sable Island, Trivett and Higuchi (1989) reported that the mean annual rate of increase, obtained from the slope of a least-squares regression line through the annual averages, was 1.48 ppmv per year.

Evaluation of the release of dioxins and PCBs during kiln-firing of ball clay.

PubMed

Broadwater, Kendra; Meeker, John D; Luksemburg, William; Maier, Martha; Garabrant, David; Demond, Avery; Franzblau, Alfred

2014-01-01

Ball clay is known to be naturally contaminated with high levels of polychlorinated di-benzo-p-dioxins (PCDDs). This study evaluated the potential for PCDD, polychlorinated dibenzofuran (PCDF) and polychlorinated biphenyl (PCB) release during the kiln firing of ball clay in an art studio. Toxic equivalence (TEQ) were calculated using World Health Organization (WHO) 2005 toxic equivalence factors (TEF) and congener concentrations. Ten bags of commercial ball clay were found to have an average TEQ of 1,370 nanograms/kilogram (ng kg(-1)) dry weight (dw), almost exclusively due to PCDDs (99.98% of TEQ). After firing, none of the 29 dioxin-like analytes was measured above the limits of detection (LOD) in the clay samples. Air samples were taken during firings using both low-flow and high-flow air samplers. Few low-flow air samples contained measurable levels of dioxin congeners above the LOD. The mean TEQ in the high volume air samples ranged from 0.07 pg m(-3) to 0.21 pg m(-3) when firing ball clay, and was 0.11 pg m(-3) when no clay was fired. These concentrations are within the range measured in typical residences and well-controlled industrial settings. The congener profiles in the high-flow air samples differed from the unfired clay; the air samples had a considerable contribution to the TEQ from PCDFs and PCBs. Given that the TEQs of all air samples were very low and the profiles differed from the unfired clay, it is likely that the PCDDs in dry ball clay were destroyed during kiln firing. These results suggest that inhalation of volatilized dioxins during kiln firing of dry ball clay is an unlikely source of exposure for vocational and art ceramicists. Copyright © 2013 Elsevier Ltd. All rights reserved.

Stable Carbon Isotope Ratios in Atmospheric VOC across the Asian Summer Monsoon Anticyclone obtained during the OMO-ASIA campaign

NASA Astrophysics Data System (ADS)

Krebsbach, Marc; Koppmann, Ralf; Meisehen, Thomas

2017-04-01

The automated high volume air sampling system (MIRAH) has been deployed during the atmospheric measurement campaign OMO-ASIA (Oxidation Mechanism Observations) with the German High Altitude - Long-range research aircraft (HALO) in July and August 2015. The intensive measurement period with base stations in Paphos (Cyprus) and Gan (Maldives) focussed on oxidation processes and air pollution chemistry downwind of the South Asia summer monsoon anticyclone, a pivot area critical for air quality and climate change, both regionally and worldwide. The measurement region covered the Eastern Mediterranean region, the Arabian Peninsula, Egypt, and the Arabian Sea. In total 194 air samples were collected on 17 flights in a height region from 3 km up to 15 km. The air samples were analysed for stable carbon isotope ratios in VOC with GC-C-IRMS in the laboratory afterwards. We determined stable carbon isotope ratios and mixing ratios of several aldehydes, ketones, alcohols, and aromatics. The large extent of the investigated area allowed for encountering air masses with different origin, characteristic, and atmospheric processing, e.g. Mediterranean air masses, crossing of polluted filaments and remnants of the Asian monsoon outflow, split of the Asian monsoon anticyclone. In this presentation we will show first results and interpretations supported by HYSPLIT backward trajectories.

40 CFR 86.527-90 - Test procedures, overview.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 86.527-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... constant volume (variable dilution) sampler. (d) Except in cases of component malfunction or failure, all... emissions measurements are made. For exhaust testing, this requires sampling and analysis of the dilution...

Results from the Space Shuttle STS-95 Electronic Nose Experiment

NASA Technical Reports Server (NTRS)

Ryan, M. A.; Buehler, M. G.; Homer, M. L.; Mannatt, K. S.; Lau, B.; Jackson, S.; Zhou, H.

2000-01-01

A miniature electronic nose in which the sensing media are insulating polymers loaded with carbon black as a conductive medium has been designed and built at the Jet Propulsion Laboratory. The ENose has a volume of 1700 cc, weighs 1.4 kg including the operating computer, and uses 1.5 W average power (3 W peak power). This ENose was used in a demonstration experiment aboard STS-95 (October, 1998), in which the ENose was operated continuously for six days and recorded the sensors' response to the air in the middeck. The ENose was designed to detect ten common contaminants in space shuttle crew quarters air. The experiment was controlled by collecting air samples daily and analyzing them using standard analytical techniques after the flight. Changes in humidity were detected and quantified, neither the ENose nor the air samples detected any of the contaminants on the target list. The device is microgravity insensitive.

Evaluation of Sampling Methods for Bacillus Spore ...

EPA Pesticide Factsheets

Journal Article Following a wide area release of biological materials, mapping the extent of contamination is essential for orderly response and decontamination operations. HVAC filters process large volumes of air and therefore collect highly representative particulate samples in buildings. HVAC filter extraction may have great utility in rapidly estimating the extent of building contamination following a large-scale incident. However, until now, no studies have been conducted comparing the two most appropriate sampling approaches for HVAC filter materials: direct extraction and vacuum-based sampling.

Low concentrations of persistent organic pollutants (POPs) in air at Cape Verde.

PubMed

Nøst, Therese Haugdahl; Halse, Anne Karine; Schlabach, Martin; Bäcklund, Are; Eckhardt, Sabine; Breivik, Knut

2018-01-15

Ambient air is a core medium for monitoring of persistent organic pollutants (POPs) under the Stockholm Convention and is used in studies of global transports of POPs and their atmospheric sources and source regions. Still, data based on active air sampling remain scarce in many regions. The primary objectives of this study were to (i) monitor concentrations of selected POPs in air outside West Africa, and (ii) to evaluate potential atmospheric processes and source regions affecting measured concentrations. For this purpose, an active high-volume air sampler was installed on the Cape Verde Atmospheric Observatory at Cape Verde outside the coast of West Africa. Sampling commenced in May 2012 and 43 samples (24h sampling) were collected until June 2013. The samples were analyzed for selected polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hexachlorobenzene (HCB) and chlordanes. The concentrations of these POPs at Cape Verde were generally low and comparable to remote sites in the Arctic for several compounds. Seasonal trends varied between compounds and concentrations exhibited strong temperature dependence for chlordanes. Our results indicate net volatilization from the Atlantic Ocean north of Cape Verde as sources of these POPs. Air mass back trajectories demonstrated that air masses measured at Cape Verde were generally transported from the Atlantic Ocean or the North African continent. Overall, the low concentrations in air at Cape Verde were likely explained by absence of major emissions in areas from which the air masses originated combined with depletion during long-range atmospheric transport due to enhanced degradation under tropical conditions (high temperatures and concentrations of hydroxyl radicals). Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Field-based evaluation of semipermeable membrane devices (SPMDs) as passive air samplers of polyaromatic hydrocarbons (PAHs)

USGS Publications Warehouse

Bartkow, M.E.; Huckins, J.N.; Muller, J.F.

2004-01-01

Semipermeable membrane devices (SPMDs) have been used as passive air samplers of semivolatile organic compounds in a range of studies. However, due to a lack of calibration data for polyaromatic hydrocarbons (PAHs), SPMD data have not been used to estimate air concentrations of target PAHs. In this study, SPMDs were deployed for 32 days at two sites in a major metropolitan area in Australia. High-volume active sampling systems (HiVol) were co-deployed at both sites. Using the HiVol air concentration data from one site, SPMD sampling rates were measured for 12 US EPA Priority Pollutant PAHs and then these values were used to determine air concentrations at the second site from SPMD concentrations. Air concentrations were also measured at the second site with co-deployed HiVols to validate the SPMD results. PAHs mostly associated with the vapour phase (Fluorene to Pyrene) dominated both the HiVol and passive air samples. Reproducibility between replicate passive samplers was satisfactory (CV<20%) for the majority of compounds. Sampling rates ranged between 0.6 and 6.1 m3 d-1. SPMD-based air concentrations were calculated at the second site for each compound using these sampling rates and the differences between SPMD-derived air concentrations and those measured using a HiVol were, on average, within a factor of 1.5. The dominant processes for the uptake of PAHs by SPMDs were also assessed. Using the SPMD method described herein, estimates of particulate sorbed airborne PAHs with five rings or greater were within 1.8-fold of HiVol measured values. ?? 2004 Elsevier Ltd. All rights reserved.

Converting Constant Volume, Multizone Air Handling Systems to Energy Efficient Variable Air Volume Multizone Systems

DTIC Science & Technology

2017-10-26

30. Energy Information Agency Natural Gas Price Data ..................................................................................... 65 Figure...different market sectors (residential, commercial, and industrial). Figure 30. Energy Information Agency Natural Gas Price Data 7.2.3 AHU Size...1 FINAL REPORT Converting Constant Volume, Multizone Air Handling Systems to Energy Efficient Variable Air Volume Multizone

A simple novel device for air sampling by electrokinetic capture

DOE PAGES

Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; ...

2015-12-27

A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.« less

A simple novel device for air sampling by electrokinetic capture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra

A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrodemore » assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87%, with the reference filter taken as “gold standard.” Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. In conclusion, the performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.« less

A simple novel device for air sampling by electrokinetic capture.

PubMed

Gordon, Julian; Gandhi, Prasanthi; Shekhawat, Gajendra; Frazier, Angel; Hampton-Marcell, Jarrad; Gilbert, Jack A

2015-12-27

A variety of different sampling devices are currently available to acquire air samples for the study of the microbiome of the air. All have a degree of technical complexity that limits deployment. Here, we evaluate the use of a novel device, which has no technical complexity and is easily deployable. An air-cleaning device powered by electrokinetic propulsion has been adapted to provide a universal method for collecting samples of the aerobiome. Plasma-induced charge in aerosol particles causes propulsion to and capture on a counter-electrode. The flow of ions creates net bulk airflow, with no moving parts. A device and electrode assembly have been re-designed from air-cleaning technology to provide an average air flow of 120 lpm. This compares favorably with current air sampling devices based on physical air pumping. Capture efficiency was determined by comparison with a 0.4 μm polycarbonate reference filter, using fluorescent latex particles in a controlled environment chamber. Performance was compared with the same reference filter method in field studies in three different environments. For 23 common fungal species by quantitative polymerase chain reaction (qPCR), there was 100 % sensitivity and apparent specificity of 87 %, with the reference filter taken as "gold standard." Further, bacterial analysis of 16S RNA by amplicon sequencing showed equivalent community structure captured by the electrokinetic device and the reference filter. Unlike other current air sampling methods, capture of particles is determined by charge and so is not controlled by particle mass. We analyzed particle sizes captured from air, without regard to specific analyte by atomic force microscopy: particles at least as low as 100 nM could be captured from ambient air. This work introduces a very simple plug-and-play device that can sample air at a high-volume flow rate with no moving parts and collect particles down to the sub-micron range. The performance of the device is substantially equivalent to capture by pumping through a filter for microbiome analysis by quantitative PCR and amplicon sequencing.

Meteorological and operational aspects of 46 clear air turbulence sampling missions with an instrument B-57B aircraft. Volume 1: Program summary

NASA Technical Reports Server (NTRS)

Davis, R. E.; Champine, R. A.; Ehernberger, L. J.

1979-01-01

The results of 46 clear air turbulence (CAT) probing missions conducted with an extensively instrumented B-57B aircraft are summarized. Turbulence samples were obtained under diverse conditions including mountain waves, jet streams, upper level fronts and troughs, and low altitude mechanical and thermal turbulence. CAT was encouraged on 20 flights comprising 77 data runs. In all, approximately 4335 km were flown in light turbulence, 1415 km in moderate turbulence, and 255 km in severe turbulence during the program. The flight planning, operations, and turbulence forecasting aspects conducted with the B-57B aircraft are presented.

40 CFR 60.316 - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 60.316 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... for the measurement of VOC concentration. (3) Method 1 for sample and velocity traverses. (4) Method 2... smaller volumes, when necessitated by process variables or other factors, may be approved by the...

Installation Restoration Program Phase 2. Confirmation/Quantification. Stage 2. Volume 2. Tyndall Air Force Base, Florida

DTIC Science & Technology

1988-08-01

control data (lat tarK., lab spikes, and lab duplicates) in the report , as well as field quality control data. j. For those metiods which employ gas ...FORCE BASE, TEXAS 78235-5501 NOTICE This report has been prepared for the United States Air Force by Environmental Science and Engineering , Inc. (ESE...testing, field sampling, contamination assessment report preparation, and recommendations for remedial actions. U.S. Army Toxic and Hazardous Materials

In Situ Biological Treatment Test at Kelly Air Force Base. Volume 3. Appendices.

DTIC Science & Technology

1987-07-01

175 B-12 Results of Groundwater Acidity Monitoring. . . . . . . . 176 B-13 Results of Groundwater Alkalinity Monitoring . . . . . . 177 B- 14 ...Oichloroethylene 499 Vinyl chloride 850 1.2-cis dichloroethylene Pam jupe Table A-I. Results of 5/23/85 Groundwater Sampling (Continued) 14 aqualab inc. 9909...Sample No. : 08/134621 Matrix: NATURAL WATER Parameter Result Units CC SPECIAL SCAN 1400 ug/L Client I.D.: 14 ERG Sample No.: 08/134622 Matrix

Pollutant deposition via dew in urban and rural environment, Cracow, Poland

NASA Astrophysics Data System (ADS)

Muskała, Piotr; Sobik, Mieczysław; Błaś, Marek; Polkowska, Żaneta; Bokwa, Anita

2015-01-01

This study is a comparative analysis of dew in rural and urban environment. Dew samples were collected between May and October, 2009 in two reference stations in southern Poland: Cracow and Gaik-Brzezowa. The investigation included comparison of volume and chemistry of the collected samples. Due to its formation mechanisms, dew is a good indicator of air pollution. Following parameters were analyzed in 159 collected samples: pH, electric conductivity, concentration of formaldehyde and phenols, concentration of NH4+, Ca2 +, K+, Na+, and Mg2 + cations and NO2-, NO3-, SO42 -, Cl-, F-, and PO43 - anions. The frequency of dew was approximately the same, both in urban and rural conditions reaching 43% of the measurement period. Dew intensity, expressed by volume, was on average two times larger in rural environment than in urban conditions. Urban landuse was recognized as the main factor reducing dew intensity in the urban station in comparison to the rural. Furthermore, the intensity of dew depended on synoptic scale air circulation at both measurement sites. As expected, samples collected in Cracow were much more polluted than the ones from Gaik-Brzezowa. The average TIC (Total Ionic Content) parameter was approximately 50% higher at the urban station. The pH in the rural station was more acidic. NO3- anions and Ca2 + cations were predominant in both measurement sites, however the participation of Ca2 + in Cracow was higher. NO3- indicates pollutions emitted by transport and industrial sources. The concentration of the analytes in both stations, as the volume, depended on air circulation direction. For Gaik-Brzezowa the highest TIC was observed mainly within southern circulation, while for Cracow the highest TIC was noted within both northern and southern. In general the rural station represented background pollution for the whole region and the pollution in Cracow was more dependent on local urban sources as transport or industry.

CASTNet Air Toxics Monitoring Program (CATMP): VOC and carbonyl data for July, 1993 through March, 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harlos, D.P.; Edgerton, E.S.

1994-12-31

The US EPA has, under the auspices of the CASTNet program (Clean Air Status and Trends Network), initiated the CASTNet Air Toxics Monitoring Program (CATMP). Volatile Organic Compounds (VOC) and carbonyls and metals are sampled for 24-hour periods on a 12-day schedule using TO-14 samplers (SUMMA canisters) and dinitrophenylhydrazine-coated (dmph) sorbent cartridges and high volume particle samplers. Sampling was begun at most sites in July of 1993. The sites are operated by state and local air pollution control programs and all analysis is performed by Environmental Science and Engineering (ESE) in Gainesville, Florida. The network currently supports 15 VOC sites,more » of which 7 also sample carbonyls. Three sites sample metals only in Pinellas County, Florida. The limits of detection of 0.05 ppb for VOCs allow routine tracking of a wide range of pollutants including several greenhouse gases, transportation pollutants and photochemically-derived compounds. The sites range from major urban areas (Chicago, St. Louis) to a rural village (Waterbury, Vermont). Results of the first three quarters of VOC and carbonyl data collection are summarized in this presentation.« less

Determination of methyltetrahydrophthalic anhydride in air using gas chromatography with electron-capture detection.

PubMed

Johyama, Y; Yokota, K; Fujiki, Y; Takeshita, T; Morimoto, K

1999-10-01

Methyltetrahydrophthalic anhydride (MTHPA) stimulates the production of specific IgE antibodies which can cause occupational allergy even at extremely low levels of exposure (15-22 micrograms/m3). Safe use in industry demands control of the levels of exposure causing allergic diseases. Thus, the air monitoring of MTHPA is very important, and sensitive methods are required to measure low air concentrations or short-time peak exposures. This paper outlines the use of silica-gel tubes for sampling airborne MTHPA vapour, followed by analysis using gas chromatography with electron-capture detection. No breakthrough was observed at 113, 217, 673 and 830 micrograms/m3 (sampling volume 30, 60, 60 and 20 l, respectively; relative humidity 40-55%). Concentrations > 1.0 microgram/m3 could be quantified at 20-min sampling with a sampling rate of 1 l/min. The present method can also be applied to measurements of exposure to hexahydrophthalic and methylhexahydrophthalic anhydride. The risk of MTHPA exposure in two condenser plants was also assessed by determining MTHPA levels in air of the workplace. In conclusion, our method was found to be reliable and sensitive, and can be applied to the evaluation of MTHPA exposure.

Determination of regional lung air volume distribution at mid-tidal breathing from computed tomography: a retrospective study of normal variability and reproducibility

PubMed Central

2014-01-01

Background Determination of regional lung air volume has several clinical applications. This study investigates the use of mid-tidal breathing CT scans to provide regional lung volume data. Methods Low resolution CT scans of the thorax were obtained during tidal breathing in 11 healthy control male subjects, each on two separate occasions. A 3D map of air volume was derived, and total lung volume calculated. The regional distribution of air volume from centre to periphery of the lung was analysed using a radial transform and also using one dimensional profiles in three orthogonal directions. Results The total air volumes for the right and left lungs were 1035 +/− 280 ml and 864 +/− 315 ml, respectively (mean and SD). The corresponding fractional air volume concentrations (FAVC) were 0.680 +/− 0.044 and 0.658 +/− 0.062. All differences between the right and left lung were highly significant (p < 0.0001). The coefficients of variation of repeated measurement of right and left lung air volumes and FAVC were 6.5% and 6.9% and 2.5% and 3.6%, respectively. FAVC correlated significantly with lung space volume (r = 0.78) (p < 0.005). FAVC increased from the centre towards the periphery of the lung. Central to peripheral ratios were significantly higher for the right (0.100 +/− 0.007 SD) than the left (0.089 +/− 0.013 SD) (p < 0.0001). Conclusion A technique for measuring the distribution of air volume in the lung at mid-tidal breathing is described. Mean values and reproducibility are described for healthy male control subjects. Fractional air volume concentration is shown to increase with lung size. PMID:25063729

Saharan dust - A carrier of persistent organic pollutants, metals and microbes to the Caribbean?

USGS Publications Warehouse

Garrison, V.H.; Foreman, W.T.; Genualdi, S.; Griffin, Dale W.; Kellogg, C.A.; Majewski, M.S.; Mohammed, A.; Ramsubhag, A.; Shinn, E.A.; Simonich, S.L.; Smith, G.W.

2006-01-01

An international team of scientists from government agencies and universities in the United States, U.S. Virgin Islands (USVI), Trinidad & Tobago, the Republic of Cape Verde, and the Republic of Mali (West Africa) is working together to elucidate the role Saharan dust may play in the degradation of Caribbean ecosystems. The first step has been to identify and quantify the persistent organic pollutants (POPs), trace metals, and viable microorganisms in the atmosphere in dust source areas of West Africa, and in dust episodes at downwind sites in the eastern Atlantic (Cape Verde) and the Caribbean (USVI and Trinidad & Tobago). Preliminary findings show that air samples from Mali contain a greater number of pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs) and in higher concentrations than the Caribbean sites. Overall, POP concentrations were similar in USVI and Trinidad samples. Trace metal concentrations were found to be similar to crustal composition with slight enrichment of lead in Mali. To date, hundreds of cultureable micro-organisms have been identified from Mali, Cape Verde, USVI, and Trinidad air samples. The sea fan pathogen, Aspergillus sydowii, has been identified in soil from Mali and in air samples from dust events in the Caribbean. We have shown that air samples from a dust-source region contain orders of magnitude more cultureable micro-organisms per volume than air samples from dust events in the Caribbean, which in turn contain 3-to 4-fold more cultureable microbes than during non-dust conditions.

Water vapor weathering of Taurus-Littrow orange soil - A pore-structure analysis

NASA Technical Reports Server (NTRS)

Cadenhead, D. A.; Mikhail, R. S.

1975-01-01

A pore-volume analysis was performed on water vapor adsorption data previously obtained on a fresh sample of Taurus-Littrow orange soil, and the analysis was repeated on the same sample after its exposure to moist air for a period of approximately six months. The results indicate that exposure of an outgassed sample to high relative pressures of water vapor can result in the formation of substantial micropore structure, the precise amount being dependent on the sample pretreatment, particularly the outgassing temperature. Micropore formation is explained in terms of water penetration into surface defects. In contrast, long-term exposure to moist air at low relative pressures appears to reverse the process with the elimination of micropores and enlargement of mesopores possibly through surface diffusion of metastable adsorbent material. The results are considered with reference to the storage of lunar samples.

Radar volume reflectivity estimation using an array of ground-based rainfall drop size detectors

NASA Astrophysics Data System (ADS)

Lane, John; Merceret, Francis; Kasparis, Takis; Roy, D.; Muller, Brad; Jones, W. Linwood

2000-08-01

Rainfall drop size distribution (DSD) measurements made by single disdrometers at isolated ground sites have traditionally been used to estimate the transformation between weather radar reflectivity Z and rainfall rate R. Despite the immense disparity in sampling geometries, the resulting Z-R relation obtained by these single point measurements has historically been important in the study of applied radar meteorology. Simultaneous DSD measurements made at several ground sites within a microscale area may be used to improve the estimate of radar reflectivity in the air volume surrounding the disdrometer array. By applying the equations of motion for non-interacting hydrometers, a volume estimate of Z is obtained from the array of ground based disdrometers by first calculating a 3D drop size distribution. The 3D-DSD model assumes that only gravity and terminal velocity due to atmospheric drag within the sampling volume influence hydrometer dynamics. The sampling volume is characterized by wind velocities, which are input parameters to the 3D-DSD model, composed of vertical and horizontal components. Reflectivity data from four consecutive WSR-88D volume scans, acquired during a thunderstorm near Melbourne, FL on June 1, 1997, are compared to data processed using the 3D-DSD model and data form three ground based disdrometers of a microscale array.

Analytical modeling of operating characteristics of premixing-prevaporizing fuel-air mixing passages. Volume 2: User's manual

NASA Technical Reports Server (NTRS)

Anderson, O. L.; Chiappetta, L. M.; Edwards, D. E.; Mcvey, J. B.

1982-01-01

A user's manual describing the operation of three computer codes (ADD code, PTRAK code, and VAPDIF code) is presented. The general features of the computer codes, the input/output formats, run streams, and sample input cases are described.

Evaluation of Bio-VOC Sampler for Analysis of Volatile Organic Compounds in Exhaled Breath

PubMed Central

Kwak, Jae; Fan, Maomian; Harshman, Sean W.; Garrison, Catherine E.; Dershem, Victoria L.; Phillips, Jeffrey B.; Grigsby, Claude C.; Ott, Darrin K.

2014-01-01

Monitoring volatile organic compounds (VOCs) from exhaled breath has been used to determine exposures of humans to chemicals. Prior to analysis of VOCs, breath samples are often collected with canisters or bags and concentrated. The Bio-VOC breath sampler, a commercial sampling device, has been recently introduced to the market with growing use. The main advantage for this sampler is to collect the last portion of exhaled breath, which is more likely to represent the air deep in the lungs. However, information about the Bio-VOC sampler is somewhat limited. Therefore, we have thoroughly evaluated the sampler here. We determined the volume of the breath air collected in the sampler was approximately 88 mL. When sampling was repeated multiple times, with the succeeding exhalations applied to a single sorbent tube, we observed linear relationships between the normalized peak intensity and the number of repeated collections with the sampler in many of the breath VOCs detected. No moisture effect was observed on the Tenax sorbent tubes used. However, due to the limitation in the collection volume, the use of the Bio-VOC sampler is recommended only for detection of VOCs present at high concentrations unless repeated collections of breath samples on the sampler are conducted. PMID:25532709

Validation of Satellite AOD Data with the Ground PM10 Data over Islamabad Pakistan

NASA Astrophysics Data System (ADS)

Bulbul, Gufran; Shahid, Imran

2016-07-01

Introduction The issue of air pollution affects the entire globe, but the countries having huge urban growth and industries are specially confronted with high amounts of suspended particles in atmosphere. According to WHO, for the areas where air pollution is monitored in Pakistan, the air pollution is deteriorating the air quality as time is passing. Pakistan, during the last decade, has seen an extensive rise in population growth, urbanization, and industrialization, together with a great increase in motorization and energy use. As a result, rise has taken place in the emission of various air pollutants. However, due to the lack of air quality management, the country is suffering from deterioration of air quality. From the air quality point of view, spatial and temporal distribution of aerosols and its variations are very important. The variations in the atmospheric aerosol, land surface properties, greenhouse gases, solar radiations and climatic changes alter the energy balance of the earth's atmospheric system. The addition of aerosol particles to the atmosphere is not only dependent upon the anthropogenic sources but these are also formed by physical and chemical atmospheric processes. Aerosols are a mixture of particles and these are characterized by their shape, their size (from nanometers (nm) to micrometers (µm) in radius) and their chemical composition. PM10 is the designation for particulate matter in the atmosphere that has an aerodynamic diameter of 10µm or less. The sources of PM10 may be natural (volcanoes, dust, storms, forest and grassland fires, living vegetation, or anthropogenic (burning of fossil fuels in vehicles, power plants and industrialization). The current interest in atmospheric particulate matter (PM10) is mainly due to its effect on human health and its role in climate change. Therefore, the particulate matter must be monitored continuously to understand their likely impact on the atmosphere, environment and particularly human health. In this study, concentrations of PM10 will be monitored at different sites in H-12 sector and Kashmir Highway Islamabad using High volume air sampler and its chemical characterization will be done using Energy Dispersive XRF. The first application of satellite remote sensing for aerosol monitoring began in the mid-1970s to detect the desert particles above the ocean using data from Landsat, GOES, and AVHRR remote sensing satellites. Maps of Aerosol Optical Depth (AOD) over the ocean were produced using the 0.63 µm channel of Advanced Very High Resolution Radiometer (AVHRR) . Aerosols properties were retrieved using AVHRR. The useable range of wavelengths of spectrum (shorter wavelengths and the longer wavelengths) for the remote sensing of the aerosols particles is mostly restricted due to ozone and gaseous absorptions. The purpose of the study is to validate the satellite Aerosol Optical Depth (AOD) data for the regional and local scale for Pakistan Objectives • To quantify the concentration of PM10 • To investigate their elemental composition • To find out their possible sources • Validation with MODIS satellite AOD Methodology: PM10 concentration will be measured at different sites of NUST Islamabad, Pakistan using High volume air sampler an Air sampling equipment capable of sampling high volumes of air (typically 57,000 ft3 or 1,600 m3) at high flow rates (typically 1.13 m3/min or 40 ft3/min) over an extended sampling duration (typically 24 hrs). The sampling period will be of 24 hours. Particles in the PM10 size range are then collected on the filter(s) during the specified 24-h sampling period. Each sample filter will be weighed before and after sampling to determine the net weight (mass) gain of the collected PM10 sample (40 CFR Part 50, Appendix M, US EPA). Next step will be the chemical characterization. Element concentrations will be determined by energy dispersive X-ray fluorescence (ED-XRF) technique. The ED-XRF system uses an X-ray tube to excite the sample - which is located in a vacuum chamber - and a high-resolution semiconductor detector to measure the characteristic X-lines emitted by the sample. Comparison with Satellite AOD MODIS data The AOD data from Terra- MODIS was used to compare and generate a good relationship between ground PM10 data with satellite AOD data. The data of specific days (in accordance to ground sampling) from MODIS website was downloaded. The data was processed and mask by using Arc-GIS tool. All MODIS data were downloaded from the NASA Earth Observatory, NEO web site allowed queries of the spatial, temporal, spectral characteristics and conversion of the data to GeoTiFF format.

Methods of obtaining a uniform volume concentration of implanted ions

NASA Astrophysics Data System (ADS)

Reutov, V. F.

1998-05-01

Three simple practical methods of irradiation with high energy particles (>5 MeV/n), providing the conditions of obtaining a uniform volume concentration of the implanted ions in the massive samples are described in the present paper. Realization of the condition of two-sided irradiation of a plane sample during its rotation in the flux of the projectiles is the basis of the first method. The use of free air as a filter with varying absorbent ability due to the movement of the irradiated sample along ion beam brought to the atmosphere is at the basis of the second method of uniform ion alloying. The third method of obtaining a uniform volume concentration of the implanted ions in a massive sample consists of sample irradiation through the absorbent filter in the shape of a foil curved according to the parabolic law moving along its surface. The first method is the most effective for obtaining a great number of the samples, for mechanical tests, for example, the second one - for irradiation in different gaseous media, the third one - for obtaining high concentration of the implanted ions under controlled (regulated) thermal and deformation conditions.

Formaldehyde: a comparative evaluation of four monitoring methods

DOE Office of Scientific and Technical Information (OSTI.GOV)

Coyne, L.B.; Cook, R.E.; Mann, J.R.

1985-10-01

The performances of four formaldehyde monitoring devices were compared in a series of laboratory and field experiments. The devices evaluated included the DuPont C-60 formaldehyde badge, the SKC impregnated charcoal tube, an impinger/polarographic method and the MDA Lion formaldemeter. The major evaluation parameters included: concentration range, effects of humidity, sample storage, air velocity, accuracy, precision, interferences from methanol, styrene, 1,3-butadiene, sulfur dioxide and dimethylamine. Based on favorable performances in the laboratory and field, each device was useful for monitoring formaldehyde in the industrial work environment; however, these devices were not evaluated for residential exposure assessment. The impinger/polarographic method had amore » sensitivity of 0.06 ppm, based on a 20-liter air sample volume, and accurately determined the short-term excursion limit (STEL). It was useful for area monitoring but was not very practical for time-weighted average (TWA) personal monitoring measurements. The DuPont badge had a sensitivity of 2.8 ppm-hr and accurately and simply determined TWA exposures. It was not sensitive enough to measure STEL exposures, however, and positive interferences resulted if 1,3-butadiene was present. The SKC impregnated charcoal tube measured both TWA and STEL concentrations and had a sensitivity of 0.06 ppm based on a 25-liter air sample volume. Lightweight and simple to use, the MDA Lion formaldemeter had a sensitivity of 0.2 ppm. It had the advantage of giving an instantaneous reading in the field; however, it must be used with caution because it responded to many interferences. The method of choice depended on the type of sampling required, field conditions encountered during sampling and an understanding of the limitations of each monitoring device.« less

Mechanical Properties of Misers Bluff Sand.

DTIC Science & Technology

1986-09-01

in Chapter 4. 4 .7 Y~ e -~1 % CHAPTER 2 LABORATORY TESTS 2.1 CONVENTIONAL SOIL TESTS Samples of MB sand were split from the available supply of...air Va , and void ratio e (the ratio of void volume to solid volume). These composition data are listed in Table 2.1 for each test. 5 2.3 MECHANICAL...and diameter changes are made. The data can be plotted as principal stress difference versus axial strain, the slope of which is Young’s modulus E

Tank vapor characterization project. Headspace vapor characterization of Hanford waste tank 241-BY-108: Second comparison study results from samples collected on 3/28/96

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thomas, B.L.; Pool, K.H.; Evans, J.C.

1997-01-01

This report describes the analytical results of vapor samples taken from the headspace of waste storage tank 241-BY-108 (Tank BY-108) at the Hanford Site in Washington State. The results described in this report is the second in a series comparing vapor sampling of the tank headspace using the Vapor Sampling System (VSS) and In Situ Vapor Sampling (ISVS) system without high efficiency particulate air (HEPA) prefiltration. The results include air concentrations of water (H{sub 2}O) and ammonia (NH{sub 3}), permanent gases, total non-methane organic compounds (TO-12), and individual organic analytes collected in SUMMA{trademark} canisters and on triple sorbent traps (TSTs).more » Samples were collected by Westinghouse Hanford Company (WHC) and analyzed by Pacific Northwest National Laboratory (PNNL). Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Analyte concentrations were based on analytical results and, where appropriate, sample volume measurements provided by WHC.« less

Solid sorbent air sampling and analytical procedure for methyl-, dimethyl-, ethyl-, and diethylamine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elskamp, C.J.; Schultz, G.R.

1986-01-01

A sampling and analytical procedure for methyl-, dimethyl-, ethyl-, and diethylamine was developed in order to avoid problems typically encountered in the sampling and analysis of low molecular weight aliphatic amines. Samples are collected with adsorbent tubes containing Amberlite XAD-7 resin coated with the derivatizing reagent, NBD chloride (7-chloro-4-nitrobenzo-2-oxa-1,3-diazole). Analysis is performed by high performance liquid chromatography with the use of a fluorescence and/or UV/visible detector. All four amines can be monitored simultaneously, and neither collection nor storage is affected by humidity. Samples are stable at room temperature for at least two weeks. The methodology has been tested for eachmore » of the four amines at sample loadings equivalent to air concentration ranges of 0.5 to 30 ppm for a sample volume of 10 liters. The method shows promise for determining other airborne primary and secondary low molecular weight aliphatic amines.« less

40 CFR 53.56 - Test for effect of variations in ambient pressure.

Code of Federal Regulations, 2010 CFR

2010-07-01

... measurement accuracy. (iv) Coefficient of variability measurement accuracy. (v) Ambient pressure measurement... through the sample filter, measured in actual volume units at the temperature and pressure of the air as... volumetric flow rate corrections are made based on measurements of actual ambient temperature and pressure...

Design and Calibration of a High Volume Cascade Impactor

ERIC Educational Resources Information Center

Gussman, R. A.; And Others

1973-01-01

This study was to develop an air sampling device capable of classifying large quantities of airborne particulate matter into discrete size fractions. Such fractionation will facilitate chemical analysis of the various particulate pollutants and thereby provide a more realistic assessment of the effects of particulate matter on human beings. (BL)

Temporal soil bulk density following tillage

USDA-ARS?s Scientific Manuscript database

Soil is the medium for air, energy, water, and chemical transport between the atmosphere and the solid earth. Soil bulk density is a key variable impacting the rate at which this transport occurs. Typically, soil bulk density is measured by the gravimetric method, where a sample of known volume is t...

40 CFR 60.456 - Test methods and procedures.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Section 60.456 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... § 60.453. (2) Method 25 for the measurement of the VOC concentration in the gas stream vent. (3) Method... sampling times or smaller volumes, when necessitated by process variables or other factors, may be approved...

IDENTIFICATION AND EMISSION FACTORS OF MOLECULAR TRACERS IN ORGANIC AEROSOLS FROM BIOMASS BURNING PART 1. TEMPERATE CLIMATE CONIFERS. (R823990)

EPA Science Inventory

Smoke particulate matter from conifers subjected to controlled burning, both under smoldering and flaming conditions, was sampled by high volume air filtration on precleaned quartz fiber filters. The filtered particles were extracted with dichloromethane and the crude extracts...

IDENTIFICATION AND EMISSION FACTORS OF MOLECULAR TRACERS IN ORGANIC AEROSOLS FROM BIOMASS BURNING PART 2. DECIDUOUS TREES. (R823990)

EPA Science Inventory

Smoke particulate matter from deciduous trees (angiosperms) subjected to controlled burning, both under smoldering and flaming conditions, was sampled by high volume air filtration on precleaned quartz fiber filters. The filtered particles were extracted with dichloromethane a...

EFFECTS OF APPLIANCE TYPE AND OPERATING VARIABLES ON WOODSTOVE EMISSIONS: VOLUME II. APPENDICIES D-F.

EPA Science Inventory

The report gives results of a project, in support of the intergared Air Cancer Project (IACP), to provide data on the specific effects of appliance type and operating variables on woodstove emissions. samples of particulate material and volatile organic compounds (VOCs) were coll...

Risk for intracranial pressure increase related to enclosed air in post-craniotomy patients during air ambulance transport: a retrospective cohort study with simulation.

PubMed

Brändström, Helge; Sundelin, Anna; Hoseason, Daniela; Sundström, Nina; Birgander, Richard; Johansson, Göran; Winsö, Ola; Koskinen, Lars-Owe; Haney, Michael

2017-05-12

Post-craniotomy intracranial air can be present in patients scheduled for air ambulance transport to their home hospital. We aimed to assess risk for in-flight intracranial pressure (ICP) increases related to observed intracranial air volumes, hypothetical sea level pre-transport ICP, and different potential flight levels and cabin pressures. A cohort of consecutive subdural hematoma evacuation patients from one University Medical Centre was assessed with post-operative intracranial air volume measurements by computed tomography. Intracranial pressure changes related to estimated intracranial air volume effects of changing atmospheric pressure (simulating flight and cabin pressure changes up to 8000 ft) were simulated using an established model for intracranial pressure and volume relations. Approximately one third of the cohort had post-operative intracranial air. Of these, approximately one third had intracranial air volumes less than 11 ml. The simulation estimated that the expected changes in intracranial pressure during 'flight' would not result in intracranial hypertension. For intracranial air volumes above 11 ml, the simulation suggested that it was possible that intracranial hypertension could develop 'inflight' related to cabin pressure drop. Depending on the pre-flight intracranial pressure and air volume, this could occur quite early during the assent phase in the flight profile. DISCUSSION: These findings support the idea that there should be radiographic verification of the presence or absence of intracranial air after craniotomy for patients planned for long distance air transport. Very small amounts of air are clinically inconsequential. Otherwise, air transport with maintained ground-level cabin pressure should be a priority for these patients.

Effects of air vessel on water hammer in high-head pumping station

NASA Astrophysics Data System (ADS)

Wang, L.; Wang, F. J.; Zou, Z. C.; Li, X. N.; Zhang, J. C.

2013-12-01

Effects of air vessel on water hammer process in a pumping station with high-head were analyzed by using the characteristics method. The results show that the air vessel volume is the key parameter that determines the protective effect on water hammer pressure. The maximum pressure in the system declines with increasing air vessel volume. For a fixed volume of air vessel, the shape of air vessel and mounting style, such as horizontal or vertical mounting, have little effect on the water hammer. In order to obtain good protection effects, the position of air vessel should be close to the outlet of the pump. Generally, once the volume of air vessel is guaranteed, the water hammer of a entire pipeline is effectively controlled.

Installation Restoration Program (IRP) Site Investigation Report for IRP Site Number 4. Volume 3. Appendices D-I. 128th Air Refueling Wing, Wisconsin Air National Guard, General Billy Mitchell Field Air National Guard Base, Milwaukee, Wisconsin.

DTIC Science & Technology

1996-03-01

NATIONAL GUARD GENERAL BILLY MITCHELL FIELD AIR NATIONAL GUARD BASE MILWAUKEE, WISCONSIN MARCH 1996 ______ 19960509 134 HQ ANG/CEVR ANDREWS AFB...Report for IRP Site No. 4, Wisconsin Air National Guard, 128th Air Refueling Wing, General Billy Mitchell Field, Milwaukee, Wisconsin - Volume III...Wisconsin Air National Guard, 128th Air Refueling Wing, General Billy Mitchell Field, Milwaukee, Wisconsin, Volume III - Appendices D-I. This is the

Discussion on fresh air volume in Temperature and Humidity Independent Control of Air-conditioning System

NASA Astrophysics Data System (ADS)

Cheng, Xiaolong; Liu, Jinxiang; Wang, Yu; Yuan, Xiaolei; Jin, Hui

2018-05-01

The fresh air volume in Temperature and Humidity Independent Control of Air-conditioning System(THIC) of a typical office was comfirmed, under the premise of adopting the refrigeration dehumidifying fresh air unit(7°C/12°C). By detailed calculating the space moisture load and the fresh air volume required for dehumidification in 120 selected major cities in China, it can be inferred that the minimum fresh air volume required for dehumidification in THIC is mainly determined by the local outdoor air moisture and the outdoor wind speed; Then the mathematical fitting software Matlab was used to fit the three parameters, and a simplified formula for calculating the minimum per capita fresh air volume required for dehumidification was obtained; And the indoor relative humidity was simulated by the numerical software Airpak and the results by using the formula data and the data for hygiene were compared to verify the relibility of the simplified formula.

[Evaluation of measurement uncertainty of welding fume in welding workplace of a shipyard].

PubMed

Ren, Jie; Wang, Yanrang

2015-12-01

To evaluate the measurement uncertainty of welding fume in the air of the welding workplace of a shipyard, and to provide quality assurance for measurement. According to GBZ/T 192.1-2007 "Determination of dust in the air of workplace-Part 1: Total dust concentration" and JJF 1059-1999 "Evaluation and expression of measurement uncertainty", the uncertainty for determination of welding fume was evaluated and the measurement results were completely described. The concentration of welding fume was 3.3 mg/m(3), and the expanded uncertainty was 0.24 mg/m(3). The repeatability for determination of dust concentration introduced an uncertainty of 1.9%, the measurement using electronic balance introduced a standard uncertainty of 0.3%, and the measurement of sample quality introduced a standard uncertainty of 3.2%. During the determination of welding fume, the standard uncertainty introduced by the measurement of sample quality is the dominant uncertainty. In the process of sampling and measurement, quality control should be focused on the collection efficiency of dust, air humidity, sample volume, and measuring instruments.

Nickel and vanadium in air particulates at Dhahran (Saudi Arabia) during and after the Kuwait oil fires

NASA Astrophysics Data System (ADS)

Sadiq, M.; Mian, A. A.

Air particulates, both the total suspended (TSP) and inhalable (PM 10, smaller than 10 microns in size), were collected during and after the Kuwait oil fires (from March 1991 to July 1992) using Hi-Vol samplers. These samples were wet-digested at 120°C in an aqua regia and perchloric acids mixture for 3 h. Air particulate samples collected in 1982 at the same location were prepared similarly. Concentrations of nickel and vanadium were determined in the aliquot samples using an inductively coupled argon plasma analyser (ICAP). The monthly mean concentrations of nickel and vanadium, on volume basis, increased rapidly from March to June and decreased sharply during July-August in 1991. The minimum mean concentrations of these elements were found in the particulate samples collected in December 1991 which gradually increased through May 1992. Like 1991, nickel and vanadium concentrations in the air particulates spiked in June and decreased again in July 1992. This distribution pattern of nickel and vanadium concentrations was similar to that of the predominant wind from the north (Kuwait). In general, concentrations of these elements were higher in the air particulates collected during April-July 1991 as compared with those collected in 1992 during the same period. The TSPs contained higher concentrations of nickel and vanadium than those found in the PM 10 samples. However, this trend was reversed when concentrations of nickel and vanadium, on were expressed on particulate weight basis. The monthly mean concentrations of nickel and vanadium, on weight basis, decreased gradually through 1991 and increased slightly from March to July 1992. Concentrations of these elements were significantly higher in the air particulate samples collected in 1991 than those samples collected during 1982 at the same location. The data of this study suggest a contribution of the Kuwait oil fires in elevating nickel and vanadium concentrations in the air particulates at Dhahran during April-July 1991. Concentrations of these elements were largely below their proposed limits in the ambient air (for nickel-50 μg m -3, air; for vanadium—1 μg m -3 air). It is, therefore, anticipated that concentrations of nickel and vanadium in the air particulate samples were not a health concern during Kuwait oil fires at Dhahran, Saudi Arabia.

Methods, fluxes and sources of gas phase alkyl nitrates in the coastal air.

PubMed

Dirtu, Alin C; Buczyńska, Anna J; Godoi, Ana F L; Favoreto, Rodrigo; Bencs, László; Potgieter-Vermaak, Sanja S; Godoi, Ricardo H M; Van Grieken, René; Van Vaeck, Luc

2014-10-01

The daily and seasonal atmospheric concentrations, deposition fluxes and emission sources of a few C3-C9 gaseous alkyl nitrates (ANs) at the Belgian coast (De Haan) on the Southern North Sea were determined. An adapted sampler design for low- and high-volume air-sampling, optimized sample extraction and clean-up, as well as identification and quantification of ANs in air samples by means of gas chromatography mass spectrometry, are reported. The total concentrations of ANs ranged from 0.03 to 85 pptv and consisted primarily of the nitro-butane and nitro-pentane isomers. Air mass backward trajectories were calculated by the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model to determine the influence of main air masses on AN levels in the air. The shorter chain ANs have been the most abundant in the Atlantic/Channel/UK air masses, while longer chain ANs prevailed in continental air. The overall mean N fluxes of the ANs were slightly higher for summer than those for winter-spring, although their contributions to the total nitrogen flux were low. High correlations between AN and HNO₂ levels were observed during winter/spring. During summer, the shorter chain ANs correlated well with precipitation. Source apportionment by means of principal component analysis indicated that most of the gas phase ANs could be attributed to traffic/combustion, secondary photochemical formation and biomass burning, although marine sources may also have been present and a contributing factor.

Synchrotron imaging of the grasshopper tracheal system : morphological and physiological components of tracheal hypermetry.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greenlee, K. J.; Henry, J. R.; Kirkton, S. D.

2009-11-01

As grasshoppers increase in size during ontogeny, they have mass specifically greater whole body tracheal and tidal volumes and ventilation than predicted by an isometric relationship with body mass and body volume. However, the morphological and physiological bases to this respiratory hypermetry are unknown. In this study, we use synchrotron imaging to demonstrate that tracheal hypermetry in developing grasshoppers (Schistocerca americana) is due to increases in air sacs and tracheae and occurs in all three body segments, providing evidence against the hypothesis that hypermetry is due to gaining flight ability. We also assessed the scaling of air sac structure andmore » function by assessing volume changes of focal abdominal air sacs. Ventilatory frequencies increased in larger animals during hypoxia (5% O{sub 2}) but did not scale in normoxia. For grasshoppers in normoxia, inflated and deflated air sac volumes and ventilation scaled hypermetrically. During hypoxia (5% O{sub 2}), many grasshoppers compressed air sacs nearly completely regardless of body size, and air sac volumes scaled isometrically. Together, these results demonstrate that whole body tracheal hypermetry and enhanced ventilation in larger/older grasshoppers are primarily due to proportionally larger air sacs and higher ventilation frequencies in larger animals during hypoxia. Prior studies showed reduced whole body tracheal volumes and tidal volume in late-stage grasshoppers, suggesting that tissue growth compresses air sacs. In contrast, we found that inflated volumes, percent volume changes, and ventilation were identical in abdominal air sacs of late-stage fifth instar and early-stage animals, suggesting that decreasing volume of the tracheal system later in the instar occurs in other body regions that have harder exoskeleton.« less

Atmospheric ammonia mixing ratios at an open-air cattle feeding facility.

PubMed

Hiranuma, Naruki; Brooks, Sarah D; Thornton, Daniel C O; Auvermann, Brent W

2010-02-01

Mixing ratios of total and gaseous ammonia were measured at an open-air cattle feeding facility in the Texas Panhandle in the summers of 2007 and 2008. Samples were collected at the nominally upwind and downwind edges of the facility. In 2008, a series of far-field samples was also collected 3.5 km north of the facility. Ammonium concentrations were determined by two complementary laboratory methods, a novel application of visible spectrophotometry and standard ion chromatography (IC). Results of the two techniques agreed very well, and spectrophotometry is faster, easier, and cheaper than chromatography. Ammonia mixing ratios measured at the immediate downwind site were drastically higher (approximately 2900 parts per billion by volume [ppbv]) than thos measured at the upwind site (< or = 200 ppbv). In contrast, at 3.5 km away from the facility, ammonia mixing ratios were reduced to levels similar to the upwind site (< or = 200 ppbv). In addition, PM10 (particulate matter < 10 microm in optical diameter) concentrations obtained at each sampling location using Grimm portable aerosol spectrometers are reported. Time-averaged (1-hr) volume concentrations of PM10 approached 5 x 10(12) nm3 cm(-3). Emitted ammonia remained largely in the gas phase at the downwind and far-field locations. No clear correlation between concentrations of ammonia and particles was observed. Overall, this study provides a better understanding of ammonia emissions from open-air animal feeding operations, especially under the hot and dry conditions present during these measurements.

Trifluoromethyl Sulfur Pentafluoride (SF5CF3) and Sulfur Hexafluoride (SF6) from Dome Concordia (1965-1999)

DOE Data Explorer

Sturges, W. T. [School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom; Wallington, T. J. [Ford Motor Company, Dearborn, Michigan; Hurley, M. D. [Ford Motor Company, Dearborn, Michigan; Shine, K. P. [Department of Meteorology, University of Reading, Reading, United Kingdom; Sihra, K. [Department of Meteorology, University of Reading, Reading, United Kingdom; Engel, A. [Institute for Meteorology and Geophysics, Johann Wolfgang Goethe University of Frankfurt, Frankfurt, Germany; Oram, D. E. [School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom; Penkett, S. A. [School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom; Mulvaney, R. [British Antarctic Survey, Natural Environmental Research Council, Cambridge, United Kingdom; Brenninkmeijer, C A. M. [Atmospheric Chemistry Division, Max Planck Institute for Chemistry, Mainz, Germany

2000-10-01

The sampling and analytical methods are described more fully in Sturges et al. (2000). In summary, air samples were pumped from consolidated deep snow (firn) at Dome Concordia (eastern Antarctica) in December 1998 and January 1999, from the surface to a depth of approximately 100 m. Air samples were analyzed with a gas chromatograph - mass spectrometer, with a detection limit of about 0.001 parts per trillion (ppt). A diffusive transport model was used to calculate the age of samples as a function of depth. Measurements of SF6 were used to determine the mean age of the firn air by comparison with extrapolated measurements from Cape Grim, Tasmania combined with estimates from industrial emissions (Maiss and Brenninkmeijer 1998, adapted by Sturges et al. 2000). Dates for SF5CF3 are different than for SF6 due to the lower diffusivity of SF5CF3: the SF6 ages were multiplied by the ratio of the free-air diffusion coefficient of SF5CF3 to that of SF6 (1.18). Free-air diffusion coefficients were determined by a semi-empirical formula based on molecular volumes (Fuller et al. 1966). Note that mean ages represent a very wide distribution of probable ages spanning many years, with an increasing spread of ages at increasing depth

[Determination of polioksin B in the air environment and in washouts from skin of operators by HPLC].

PubMed

Volkova, V N; Mukhina, L P; Chistova, Zh A; Fedorova, S G

Polyoxin B being an effective inhibitor of synthesis of chitin of the cell wall of many phytopathogenic fungi, is recommended as a fungicide for control of phytopathogenic organisms that cause damage to crop. For the determination of the exposure of employees working with pesticides there was developed the method of the measurement of concentrations of polyoxin B in air of working area, atmospheric air of populated areas and washouts from the operators ’ integuments, based on high performance liquid chromatography with ultraviolet detector (detection wavelength of270 nm), including sampling air environment in the sorption tube ORBO-44, filled with sorbent XAD-2, extraction of the sorbent with polyoxin by a mixture of carbinol-water (in a ratio of 95:5,on volume), washout from the surface of the skin with ethyl alcohol by way of washing, concentrating, quantitative chromatographic analysis. Lower limits of the quantification ofpolyoxin B in the air ofworking area - 0.2 mg/m at the aspiration of 2 dm of air, atmospheric air - 0.016 mg/m at the aspiration of 25 dm of air, in washouts from the operators’ integuments - 0.4 pg/wash, the linear range of the defined concentrations accounted for of 0.2 - 2.4 pg/cm, the total error of measurement of the concentrations of polyoxin B in air is 17%; in washouts from the operators’ integuments - 16%. The developed method was approbated for the determination of polyoxin in samples of air of working zone, atmospheric air within the sanitary gap, washouts from the operators ’ integuments and air drift samples taken under processing of roses in the hothouse and in the monitoring of the phytosanitary condition of the plants every other day after treatment.

Comparison of coarse coal dust sampling techniques in a laboratory-simulated longwall section.

PubMed

Patts, Justin R; Barone, Teresa L

2017-05-01

Airborne coal dust generated during mining can deposit and accumulate on mine surfaces, presenting a dust explosion hazard. When assessing dust hazard mitigation strategies for airborne dust reduction, sampling is done in high-velocity ventilation air, which is used to purge the mining face and gallery tunnel. In this environment, the sampler inlet velocity should be matched to the air stream velocity (isokinetic sampling) to prevent oversampling of coarse dust at low sampler-to-air velocity ratios. Low velocity ratios are often encountered when using low flow rate, personal sampling pumps commonly used in underground mines. In this study, with a goal of employing mine-ready equipment, a personal sampler was adapted for area sampling of coarse coal dust in high-velocity ventilation air. This was done by adapting an isokinetic nozzle to the inlet of an Institute of Occupational Medicine (Edinburgh, Scotland) sampling cassette (IOM). Collected dust masses were compared for the modified IOM isokinetic sampler (IOM-MOD), the IOM without the isokinetic nozzle, and a conventional dust sampling cassette without the cyclone on the inlet. All samplers were operated at a flow rate typical of personal sampling pumps: 2 L/min. To ensure differences between collected masses that could be attributed to sampler design and were not influenced by artifacts from dust concentration gradients, relatively uniform and repeatable dust concentrations were demonstrated in the sampling zone of the National Institute for Occupational Safety and Health experimental mine gallery. Consistent with isokinetic theory, greater differences between isokinetic and non-isokinetic sampled masses were found for larger dust volume-size distributions and higher ventilation air velocities. Since isokinetic sampling is conventionally used to determine total dust concentration, and isokinetic sampling made a difference in collected masses, the results suggest when sampling for coarse coal dust the IOM-MOD may improve airborne coarse dust assessments over "off-the-shelf" sampling cassettes.

Comparison of coarse coal dust sampling techniques in a laboratory-simulated longwall section

PubMed Central

Patts, Justin R.; Barone, Teresa L.

2017-01-01

Airborne coal dust generated during mining can deposit and accumulate on mine surfaces, presenting a dust explosion hazard. When assessing dust hazard mitigation strategies for airborne dust reduction, sampling is done in high-velocity ventilation air, which is used to purge the mining face and gallery tunnel. In this environment, the sampler inlet velocity should be matched to the air stream velocity (isokinetic sampling) to prevent oversampling of coarse dust at low sampler-to-air velocity ratios. Low velocity ratios are often encountered when using low flow rate, personal sampling pumps commonly used in underground mines. In this study, with a goal of employing mine-ready equipment, a personal sampler was adapted for area sampling of coarse coal dust in high-velocity ventilation air. This was done by adapting an isokinetic nozzle to the inlet of an Institute of Occupational Medicine (Edinburgh, Scotland) sampling cassette (IOM). Collected dust masses were compared for the modified IOM isokinetic sampler (IOM-MOD), the IOM without the isokinetic nozzle, and a conventional dust sampling cassette without the cyclone on the inlet. All samplers were operated at a flow rate typical of personal sampling pumps: 2 L/min. To ensure differences between collected masses that could be attributed to sampler design and were not influenced by artifacts from dust concentration gradients, relatively uniform and repeatable dust concentrations were demonstrated in the sampling zone of the National Institute for Occupational Safety and Health experimental mine gallery. Consistent with isokinetic theory, greater differences between isokinetic and non-isokinetic sampled masses were found for larger dust volume-size distributions and higher ventilation air velocities. Since isokinetic sampling is conventionally used to determine total dust concentration, and isokinetic sampling made a difference in collected masses, the results suggest when sampling for coarse coal dust the IOM-MOD may improve airborne coarse dust assessments over “off-the-shelf” sampling cassettes. PMID:27792474

Legacy and currently used pesticides in the atmospheric environment of Lake Victoria, East Africa.

PubMed

Arinaitwe, Kenneth; Kiremire, Bernard T; Muir, Derek C G; Fellin, Phil; Li, Henrik; Teixeira, Camilla; Mubiru, Drake N

2016-02-01

The Lake Victoria watershed has extensive agricultural activity with a long history of pesticide use but there is limited information on historical use or on environmental levels. To address this data gap, high volume air samples were collected from two sites close to the northern shore of Lake Victoria; Kakira (KAK) and Entebbe (EBB). The samples, to be analyzed for pesticides, were collected over various periods between 1999 and 2004 inclusive (KAK 1999-2000, KAK 2003-2004, EBB 2003 and EBB 2004 sample sets) and from 2008 to 2010 inclusive (EBB 2008, EBB 2009 and EBB 2010 sample sets). The latter sample sets (which also included precipitation samples) were also analyzed for currently used pesticides (CUPs) including chlorpyrifos, chlorthalonil, metribuzin, trifluralin, malathion and dacthal. Chlorpyrifos was the predominant CUP in air samples with average concentrations of 93.5, 26.1 and 3.54 ng m(-3) for the EBB 2008, 2009, 2010 sample sets, respectively. Average concentrations of total endosulfan (ΣEndo), total DDT related compounds (ΣDDTs) and hexachlorocyclohexanes (ΣHCHs) ranged from 12.3-282, 22.8-130 and 3.72-81.8 pg m(-3), respectively, for all the sample sets. Atmospheric prevalence of residues of persistent organic pollutants (POPs) increased with fresh emissions of endosulfan, DDT and lindane. Hexachlorobenzene (HCB), pentachlorobenzene (PeCB) and dieldrin were also detected in air samples. Transformation products, pentachloroanisole, 3,4,5-trichloroveratrole and 3,4,5,6-tetrachloroveratrole, were also detected. The five most prevalent compounds in the precipitation samples were in the order chlorpyrifos>chlorothalonil>ΣEndo>ΣDDTs>ΣHCHs with average fluxes of 1123, 396, 130, 41.7 and 41.3 ng m(-2)sample(-1), respectively. PeCB exceeded HCB in precipitation samples. The reverse was true for air samples. Backward air trajectories suggested transboundary and local emission sources of the analytes. The results underscore the need for a concerted regional vigilance in management of chemicals. Copyright © 2015 Elsevier B.V. All rights reserved.

The active and passive sampling of benzene, toluene, ethyl benzene and xylenes compounds using the inside needle capillary adsorption trap device.

PubMed

Shojania, S; Oleschuk, R D; McComb, M E; Gesser, H D; Chow, A

1999-08-23

A new and simple method of solventless extraction of volatile organic compounds (VOCs) from air is presented. The sampling device has an adsorbing carbon coating on the interior surface of a hollow needle, and is called the inside needle capillary adsorption trap (INCAT). This paper describes a study of the reproducibility in the preparation and sampling of the INCAT device. In addition, this paper examines the effects of sample volume in active sampling and exposure time in passive sampling on the analyte adsorption. Analysis was achieved by sampling the air from an environmental chamber doped with benzene, toluene, ethyl benzene and xylenes (BTEX) compounds. Initial rates of adsorption were found to vary among the different compounds, but ranged from 0.0099 to 0.016 nmol h(-1) for passive sampling and from 2.2 to 10 nmol h(-1) for active sampling. Analysis was done by thermal desorption of the adsorbed compounds directly into a gas chromatograph injection port. Quantification of the analysis was done by comparison to actively sampled activated carbon solid phase extraction (SPE) measurements.

Permeability of gypsum samples dehydrated in air

NASA Astrophysics Data System (ADS)

Milsch, Harald; Priegnitz, Mike; Blöcher, Guido

2011-09-01

We report on changes in rock permeability induced by devolatilization reactions using gypsum as a reference analog material. Cylindrical samples of natural alabaster were dehydrated in air (dry) for up to 800 h at ambient pressure and temperatures between 378 and 423 K. Subsequently, the reaction kinetics, so induced changes in porosity, and the concurrent evolution of sample permeability were constrained. Weighing the heated samples in predefined time intervals yielded the reaction progress where the stoichiometric mass balance indicated an ultimate and complete dehydration to anhydrite regardless of temperature. Porosity showed to continuously increase with reaction progress from approximately 2% to 30%, whilst the initial bulk volume remained unchanged. Within these limits permeability significantly increased with porosity by almost three orders of magnitude from approximately 7 × 10-19 m2 to 3 × 10-16 m2. We show that - when mechanical and hydraulic feedbacks can be excluded - permeability, reaction progress, and porosity are related unequivocally.

Determination of decamethylcyclopentasiloxane in air using commercial solid phase extraction cartridges.

PubMed

Kierkegaard, Amelie; McLachlan, Michael S

2010-05-21

Decamethylcyclopentasiloxane (D(5)), a high production volume chemical used in personal care products, has been designated for regulation in Canada and is under review in the EU because of concerns about its persistence and potential for bioaccumulation in the environment. D(5) is a volatile compound expected to be found primarily in air, but there is little information on atmospheric concentrations due to the lack of sensitive analytical methods. Here a simple and sensitive method to determine D(5) in ambient air is presented. The challenge in the environmental analysis of D(5) is avoiding contamination. Our method is based on the high trapping efficiency of the sorbent Isolute ENV+, combined with a comparably high sampling rate. A small amount of sorbent (10 mg) is eluted in a small volume of n-hexane (0.1-0.6 mL), which is injected onto a GC/MS system without further processing. The simplicity of the method enables the use of a field blank for every sample to trace contamination. The method provides low limits of quantification (approximately 0.3 ng/m(3)), good repeatability and limited breakthrough (approximately 1%). By lowering the limit of quantification compared to published work by almost two orders of magnitude, it became possible to quantify D(5) in ambient air at locations remote from strong point sources. The concentrations at a rural Swedish site ranged from 0.7 to 8 ng/m(3) over a period of 4 months. 2010 Elsevier B.V. All rights reserved.

A general multiblock Euler code for propulsion integration. Volume 3: User guide for the Euler code

NASA Technical Reports Server (NTRS)

Chen, H. C.; Su, T. Y.; Kao, T. J.

1991-01-01

This manual explains the procedures for using the general multiblock Euler (GMBE) code developed under NASA contract NAS1-18703. The code was developed for the aerodynamic analysis of geometrically complex configurations in either free air or wind tunnel environments (vol. 1). The complete flow field is divided into a number of topologically simple blocks within each of which surface fitted grids and efficient flow solution algorithms can easily be constructed. The multiblock field grid is generated with the BCON procedure described in volume 2. The GMBE utilizes a finite volume formulation with an explicit time stepping scheme to solve the Euler equations. A multiblock version of the multigrid method was developed to accelerate the convergence of the calculations. This user guide provides information on the GMBE code, including input data preparations with sample input files and a sample Unix script for program execution in the UNICOS environment.

27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

Code of Federal Regulations, 2012 CFR

2012-04-01

... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

Code of Federal Regulations, 2010 CFR

2010-04-01

... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

Code of Federal Regulations, 2011 CFR

2011-04-01

... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

Code of Federal Regulations, 2013 CFR

2013-04-01

... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

27 CFR 30.66 - Table 6, showing respective volumes of alcohol and water and the specific gravity in both air and...

Code of Federal Regulations, 2014 CFR

2014-04-01

... respective volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor... volumes of alcohol and water and the specific gravity in both air and vacuum of spirituous liquor. This... gallon of water in air by the specific gravity in air of the spirits—8.32823 by 0.88862—the product (7...

Metals Emissions from the Open Detonation Treatment of Energetic Wastes

DTIC Science & Technology

2004-10-01

CPIA Publication 477, Vol. I, March 1988. p. 139. 12. Naval Air Warfare Center Weapons Division. "Fragment Breakup Testing of BLU-97 Bomblets with PBXN ...volume at the time the particulate sample was collected was approximately 106 m3. For unknown reasons, the Army did not convert the detonation plume

EFFECTS OF APPLIANCE TYPE AND OPERATING VARIABLES ON WOODSTOVE EMISSIONS: VOLUME I. REPORT AND APPENDICIES A-C.

EPA Science Inventory

The report gives results of a project, in support of the intergrated Air Canver Project (IACP) to provide data on the specific effects of appliance type and operating variales on woodstove emissions. Samples of particulate material and volatile organic compounds (VOCs) were colle...

Novel sampling methods for atmospheric semi-volatile organic compounds (SOCs) in a high altitude alpine environment.

PubMed

Offenthaler, I; Jakobi, G; Kaiser, A; Kirchner, M; Kräuchi, N; Niedermoser, B; Schramm, K-W; Sedivy, I; Staudinger, M; Thanner, G; Weiss, P; Moche, W

2009-12-01

High- and low-volume active air samplers as well as bulk deposition samplers were developed to sample atmospheric SOCs under the adverse conditions of a mountain environment. Active sampling employed separate filters for different European source regions. Filters were switched depending on daily trajectory forecasts, whose accuracy was evaluated post hoc. The sampling continued on three alpine summits over five periods of four months. The prevailing trajectories varied stronger between sampling periods than between stations. The sampling equipment (active and bulk deposition) proved dependable for operation in a mountain environment, with idle times being mainly due to non-routine manipulations and connectivity.

Determination of a wide range of volatile organic compounds in ambient air using multisorbent adsorption/thermal desorption and gas chromatography/mass spectrometry

USGS Publications Warehouse

Pankow, J.F.; Luo, W.; Isabelle, L.M.; Bender, D.A.; Baker, R.J.

1998-01-01

Adsorption/thermal desorption with multisorbent air-sampling cartridges was developed for the determination of 87 method analytes including halogenated alkanes, halogenated alkenes, ethers, alcohols, nitriles, esters, ketones, aromatics, a disulfide, and a furan. The volatilities of the compounds ranged from that of dichlorofluoromethane (CFC12) to that of 1,2,3- trichlorobenzene. The eight most volatile compounds were determined using a 1.5-L air sample and a sample cartridge containing 50 mg of Carbotrap B and 280 mg of Carboxen 1000; the remaining 79 compounds were determined using a 5-L air sample and a cartridge containing 180 mg of Carbotrap B and 70 mg of Carboxen 1000. Analysis and detection were by gas chromatography/mass spectrometry. The minimum detectable level (MDL) concentration values ranged from 0.01 parts per billion by volume (ppbv) for chlorobenzene to 0.4 ppbv for bromomethane; most of the MDL values were in the range 0.02-0.06 ppbv. No breakthrough was detected with the prescribed sample volumes. Analyte stability on the cartridges was very good. Excellent recoveries were obtained with independent check standards. Travel spike recoveries ranged from 90 to 110% for 72 of the 87 compounds. The recoveries were less than 70% for bromomethane and chloroethene and for a few compounds such as methyl acetate that are subject to losses by hydrolysis; the lowest travel spike recovery was obtained for bromomethane (62%). Blank values for all compounds were either below detection or very low. Ambient atmospheric sampling was conducted in New Jersey from April to December, 1997. Three sites characterized by low, moderate, and high densities of urbanization/traffic were sampled. The median detected concentrations of the compounds were either similar at all three sites (as with the chlorofluorocarbon compounds) or increased with the density of urbanization/traffic (as with dichloromethane, MTBE, benzene, and toluene). For toluene, the median detected concentrations were 0.23, 0.42, and 0.70 ppbv at the three sites. Analytical precision was measured using duplicate sampling. As expected, the precision deteriorated with decreasing concentration. At concentrations greater than 0.2 ppbv, most duplicates differed by less than 20%; below the MDL values, the differences between the duplicates were larger, but they were still typically less than 40%.

Pollution level and distribution of PCDD/PCDF congeners between vapor phase and particulate phase in winter air of Dalian, China.

PubMed

Wang, Wei; Qin, Songtao; Song, Yu; Xu, Qian; Ni, Yuwen; Chen, Jiping; Zhang, Xueping; Mu, Jim; Zhu, Xiuhua

2011-06-01

In December 2009, ambient air was sampled with active high-volume air samplers at two sites: on the roof of the No. l building of Dalian Jiaotong University and on the roof of the building of Dalian Meteorological Observatory. The concentrations and the congeners between vapor phase and particulate phase of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the air were measured. Sample analysis results showed that the concentrations of PCDD/Fs in particulate phase was higher than that in gaseous phase. The ratio of PCDD to PCDF in gaseous phase and particulate phase was lower than 0.4 in all samples. The total I-TEQ value in gaseous phase and particulate phase was 5.5 and 453.8 fg/m(3) at Dalian Jiaotong University, 16.6 and 462.1 fg/m(3) at Dalian Meteorological Observatory, respectively. The I-TEQ value of Dalian atmosphere was 5.5-462.1 fg/m(3) which was lower than international standard, the atmospheric quality in Dalian is better. Copyright © 2011 The Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.

3D quantification of microclimate volume in layered clothing for the prediction of clothing insulation.

PubMed

Lee, Yejin; Hong, Kyunghi; Hong, Sung-Ae

2007-05-01

Garment fit and resultant air volume is a crucial factor in thermal insulation, and yet, it has been difficult to quantify the air volume of clothing microclimate and relate it to the thermal insulation value just using the information on the size of clothing pattern without actual 3D volume measurement in wear condition. As earlier methods for the computation of air volume in clothing microclimate, vacuum over suit and circumference model have been used. However, these methods have inevitable disadvantages in terms of cost or accuracy due to the limitations of measurement equipment. In this paper, the phase-shifting moiré topography was introduced as one of the 3D scanning tools to measure the air volume of clothing microclimate quantitatively. The purpose of this research is to adopt a non-contact image scanning technology, phase-shifting moiré topography, to ascertain relationship between air volume and insulation value of layered clothing systems in wear situations where the 2D fabric creates new conditions in 3D spaces. The insulation of vests over shirts as a layered clothing system was measured with a thermal manikin in the environmental condition of 20 degrees C, 65% RH and air velocity of 0.79 m/s. As the pattern size increased, the insulation of the clothing system was increased. But beyond a certain limit, the insulation started to decrease due to convection and ventilation, which is more apparent when only the vest was worn over the torso of manikin. The relationship between clothing air volume and insulation was difficult to predict with a single vest due to the extreme openings which induced active ventilation. But when the vest was worn over the shirt, the effects of thickness of the fabrics on insulation were less pronounced compared with that of air volume. In conclusion, phase-shifting moiré topography was one of the efficient and accurate ways of quantifying air volume and its distribution across the clothing microclimate. It is also noted that air volume becomes more crucial factor in predicting thermal insulation when clothing is layered.

Installation Restoration Program (IRP). Aircraft Parking Apron Area. Volume 1. 152nd Reconnaissance Group, Nevada Air National Guard, Reno-Cannon International Airport, Reno, Nevada

DTIC Science & Technology

1994-06-01

Loeltz, 1964, Evaluation of Hydroeeology and Hydrochemistry of the Truckee Meadow Area. Washoe County. Nevada. U. S. Geological Survey, Water I Supply...was detected in water samples collected from all monitoring wells. A concentration of I 0.055 ppm for the water sample collected from monitoring well...MWO8 during the first round of sampling (MW08-(1)), exceeded the federal drinking water standard of 0.05 ppm. The I background concentration for lead

Air sampling unit for breath analyzers

NASA Astrophysics Data System (ADS)

Szabra, Dariusz; Prokopiuk, Artur; Mikołajczyk, Janusz; Ligor, Tomasz; Buszewski, Bogusław; Bielecki, Zbigniew

2017-11-01

The paper presents a portable breath sampling unit (BSU) for human breath analyzers. The developed unit can be used to probe air from the upper airway and alveolar for clinical and science studies. The BSU is able to operate as a patient interface device for most types of breath analyzers. Its main task is to separate and to collect the selected phases of the exhaled air. To monitor the so-called I, II, or III phase and to identify the airflow from the upper and lower parts of the human respiratory system, the unit performs measurements of the exhaled CO2 (ECO2) in the concentration range of 0%-20% (0-150 mm Hg). It can work in both on-line and off-line modes according to American Thoracic Society/European Respiratory Society standards. A Tedlar bag with a volume of 5 dm3 is mounted as a BSU sample container. This volume allows us to collect ca. 1-25 selected breath phases. At the user panel, each step of the unit operation is visualized by LED indicators. This helps us to regulate the natural breathing cycle of the patient. There is also an operator's panel to ensure monitoring and configuration setup of the unit parameters. The operation of the breath sampling unit was preliminarily verified using the gas chromatography/mass spectrometry (GC/MS) laboratory setup. At this setup, volatile organic compounds were extracted by solid phase microextraction. The tests were performed by the comparison of GC/MS signals from both exhaled nitric oxide and isoprene analyses for three breath phases. The functionality of the unit was proven because there was an observed increase in the signal level in the case of the III phase (approximately 40%). The described work made it possible to construct a prototype of a very efficient breath sampling unit dedicated to breath sample analyzers.

Installation Restoration Program Stage 2-1 Remedial Investigation. Beale Air Force Base, Marysville, California. Volume 1. Text and Plates

DTIC Science & Technology

1991-03-29

laboratory. In addition, weather conditions (i.e., cloud cover, pre- cipitation, air temperature, and wind speed and direction), water clarity, and...carried over a 25-foot grid in this area. The weather at the time of emissions screening was mostly sunny with high clouds . The wind was 3 to 5 knots...TRIBUTARY TO HUTCHINSON CREEK SOIL GOMMIG ANGLED 300 FROM VERTICAL Ae o * SOL. 90011GM VERTICAL 0 100, o SURFACE SOIL SAMPLE AU. VALUES ARE IN mg/Kg MONITORIG

Final Quality Assurance Project Plan, Installation Restoration Program Remedial Investigation/Feasibility Study, Kotzebue Long Range Radar Station, Alaska. Volume 2

DTIC Science & Technology

1994-10-01

right side door. To minimize retinal exposure to UV, use UV protective eyeglasses and use the offset dental mirror to read the micrometer 6.7.4.3 To...States Air Force) Volatiles Analysis by GC/MS Method 8260 - (United States Air Force) Organochlorine Pesticides and PCBs by GC/ECD Method 8081...decreasing throughout the three or four exposures . The RSD will sometimes be higher than normal in these cases. Samples that are affected by possible carry

A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices.

PubMed

Jebrail, Mais J; Renzi, Ronald F; Sinha, Anupama; Van De Vreugde, Jim; Gondhalekar, Carmen; Ambriz, Cesar; Meagher, Robert J; Branda, Steven S

2015-01-07

Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate that this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4-95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. This simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.

A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jebrail, Mais J.; Renzi, Ronald F.; Sinha, Anupama

Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate thatmore » this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4–95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. As a result, this simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.« less

A solvent replenishment solution for managing evaporation of biochemical reactions in air-matrix digital microfluidics devices

DOE PAGES

Jebrail, Mais J.; Renzi, Ronald F.; Sinha, Anupama; ...

2014-10-01

Digital microfluidics (DMF) is a powerful technique for sample preparation and analysis for a broad range of biological and chemical applications. In many cases, it is desirable to carry out DMF on an open surface, such that the matrix surrounding the droplets is ambient air. However, the utility of the air-matrix DMF format has been severely limited by problems with droplet evaporation, especially when the droplet-based biochemical reactions require high temperatures for long periods of time. We present a simple solution for managing evaporation in air-matrix DMF: just-in-time replenishment of the reaction volume using droplets of solvent. We demonstrate thatmore » this solution enables DMF-mediated execution of several different biochemical reactions (RNA fragmentation, first-strand cDNA synthesis, and PCR) over a range of temperatures (4–95 °C) and incubation times (up to 1 h or more) without use of oil, humidifying chambers, or off-chip heating modules. Reaction volumes and temperatures were maintained roughly constant over the course of each experiment, such that the reaction kinetics and products generated by the air-matrix DMF device were comparable to those of conventional benchscale reactions. As a result, this simple yet effective solution for evaporation management is an important advance in developing air-matrix DMF for a wide variety of new, high-impact applications, particularly in the biomedical sciences.« less

Seasonal variation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa Island, Japan

NASA Astrophysics Data System (ADS)

Handa, D.; Nakajima, H.; Nakaema, F.; Arakaki, T.; Tanahara, A.

2008-12-01

The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the air pollution transported from Asian continent has gained a special attention in Japan. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asian atmospheric aerosols because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. In 2005, Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) was established by the National Institute for Environmental Studies (NIES) at the northern tip of Okinawa Island, Japan to monitor the air quality of Asia. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon in the bulk aerosols collected at the CHAAMS, using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions.

Microfluidic device for robust generation of two-component liquid-in-air slugs with individually controlled composition

PubMed Central

Liu, Kan; Chen, Yi-Chun; Tseng, Hsian-Rong

2010-01-01

Using liquid slugs as microreactors and microvessels enable precise control over the conditions of their contents on short-time scales for a wide variety of applications. Particularly for screening applications, there is a need for control of slug parameters such as size and composition. We describe a new microfluidic approach for creating slugs in air, each comprising a size and composition that can be selected individually for each slug. Two-component slugs are formed by first metering the desired volume of each reagent, merging the two volumes into an end-to-end slug, and propelling the slug to induce mixing. Volume control is achieved by a novel mechanism: two closed chambers on the chip are initially filled with air, and a valve in each is briefly opened to admit one of the reagents. The pressure of each reagent can be individually selected and determines the amount of air compression, and thus the amount of liquid that is admitted into each chamber. We describe the theory of operation, characterize the slug generation chip, and demonstrate the creation of slugs of different compositions. The use of microvalves in this approach enables robust operation with different liquids, and also enables one to work with extremely small samples, even down to a few slug volumes. The latter is important for applications involving precious reagents such as optimizing the reaction conditions for radiolabeling biological molecules as tracers for positron emission tomography. Electronic supplementary material The online version of this article (doi:10.1007/s10404-010-0617-0) contains supplementary material, which is available to authorized users. PMID:20930933

Life on rock. Scaling down biological weathering in a new experimental design at Biosphere-2

NASA Astrophysics Data System (ADS)

Zaharescu, D. G.; Dontsova, K.; Burghelea, C. I.; Chorover, J.; Maier, R.; Perdrial, J. N.

2012-12-01

Biological colonization and weathering of bedrock on Earth is a major driver of landscape and ecosystem development, its effects reaching out into other major systems such climate and geochemical cycles of elements. In order to understand how microbe-plant-mycorrhizae communities interact with bedrock in the first phases of mineral weathering we developed a novel experimental design in the Desert Biome at Biosphere-2, University of Arizona (U.S.A). This presentation will focus on the development of the experimental setup. Briefly, six enclosed modules were designed to hold 288 experimental columns that will accommodate 4 rock types and 6 biological treatments. Each module is developed on 3 levels. A lower volume, able to withstand the weight of both, rock material and the rest of the structure, accommodates the sampling elements. A middle volume, houses the experimental columns in a dark chamber. A clear, upper section forms the habitat exposed to sunlight. This volume is completely sealed form exterior and it allows a complete control of its air and water parameters. All modules are connected in parallel with a double air purification system that delivers a permanent air flow. This setup is expected to provide a model experiment, able to test important processes in the interaction rock-life at grain-to- molecular scale.

Detection of airborne Stachybotrys chartarum macrocyclic trichothecene mycotoxins in the indoor environment.

PubMed

Brasel, T L; Martin, J M; Carriker, C G; Wilson, S C; Straus, D C

2005-11-01

The existence of airborne mycotoxins in mold-contaminated buildings has long been hypothesized to be a potential occupant health risk. However, little work has been done to demonstrate the presence of these compounds in such environments. The presence of airborne macrocyclic trichothecene mycotoxins in indoor environments with known Stachybotrys chartarum contamination was therefore investigated. In seven buildings, air was collected using a high-volume liquid impaction bioaerosol sampler (SpinCon PAS 450-10) under static or disturbed conditions. An additional building was sampled using an Andersen GPS-1 PUF sampler modified to separate and collect particulates smaller than conidia. Four control buildings (i.e., no detectable S. chartarum growth or history of water damage) and outdoor air were also tested. Samples were analyzed using a macrocyclic trichothecene-specific enzyme-linked immunosorbent assay (ELISA). ELISA specificity was tested using phosphate-buffered saline extracts of the fungal genera Aspergillus, Chaetomium, Cladosporium, Fusarium, Memnoniella, Penicillium, Rhizopus, and Trichoderma, five Stachybotrys strains, and the indoor air allergens Can f 1, Der p 1, and Fel d 1. For test buildings, the results showed that detectable toxin concentrations increased with the sampling time and short periods of air disturbance. Trichothecene values ranged from <10 to >1,300 pg/m3 of sampled air. The control environments demonstrated statistically significantly (P < 0.001) lower levels of airborne trichothecenes. ELISA specificity experiments demonstrated a high specificity for the trichothecene-producing strain of S. chartarum. Our data indicate that airborne macrocyclic trichothecenes can exist in Stachybotrys-contaminated buildings, and this should be taken into consideration in future indoor air quality investigations.

Effects of equipment performance on data quality from the National Atmospheric Deposition Program/National Trends Network and the Mercury Deposition Network

USGS Publications Warehouse

Wetherbee, Gregory A.; Rhodes, Mark F.

2013-01-01

The U.S. Geological Survey Branch of Quality Systems operates the Precipitation Chemistry Quality Assurance project (PCQA) to provide independent, external quality-assurance for the National Atmospheric Deposition Program (NADP). NADP is composed of five monitoring networks that measure the chemical composition of precipitation and ambient air. PCQA and the NADP Program Office completed five short-term studies to investigate the effects of equipment performance with respect to the National Trends Network (NTN) and Mercury Deposition Network (MDN) data quality: sample evaporation from NTN collectors; sample volume and mercury loss from MDN collectors; mercury adsorption to MDN collector glassware, grid-type precipitation sensors for precipitation collectors, and the effects of an NTN collector wind shield on sample catch efficiency. Sample-volume evaporation from an NTN Aerochem Metrics (ACM) collector ranged between 1.1–33 percent with a median of 4.7 percent. The results suggest that weekly NTN sample evaporation is small relative to sample volume. MDN sample evaporation occurs predominantly in western and southern regions of the United States (U.S.) and more frequently with modified ACM collectors than with N-CON Systems Inc. collectors due to differences in airflow through the collectors. Variations in mercury concentrations, measured to be as high as 47.5 percent per week with a median of 5 percent, are associated with MDN sample-volume loss. Small amounts of mercury are also lost from MDN samples by adsorption to collector glassware irrespective of collector type. MDN 11-grid sensors were found to open collectors sooner, keep them open longer, and cause fewer lid cycles than NTN 7-grid sensors. Wind shielding an NTN ACM collector resulted in collection of larger quantities of precipitation while also preserving sample integrity.

In Situ Biological Treatment Test at Kelly Air Force Base. Volume 2. Field Test Results and Cost Model

DTIC Science & Technology

1987-07-01

Groundwater." Developments in Industrial Microbiology, Volume 24, pp. 225-234. Society of Industrial Microbiology, Arlington, Virginia. 18. Product ...ESL-TR-85-52 cv) VOLUME II CN IN SITU BIOLOGICAL TREATMENT TEST AT KELLY AIR FORCE BASE, VOLUME !1: FIELD TEST RESULTS AND COST MODEL R.S. WETZEL...Kelly Air Force Base, Volume II: Field Test Results and Cost Model (UNCLASSIFIED) 12 PERSONAL AUTHOR(S) Roger S. Wetzel, Connie M. Durst, Donald H

Toxicological Assessment of ISS Air Quality: Contingency Sampling - February 2013

NASA Technical Reports Server (NTRS)

Meyers, Valerie

2013-01-01

Two grab sample containers (GSCs) were collected by crew members onboard ISS in response to a vinegar-like odor in the US Lab. On February 5, the first sample was collected approximately 1 hour after the odor was noted by the crew in the forward portion of the Lab. The second sample was collected on February 22 when a similar odor was noted and localized to the end ports of the microgravity science glovebox (MSG). The crewmember removed a glove from the MSG and collected the GSC inside the glovebox volume. Both samples were returned on SpaceX-2 for ground analysis.

Combined dispersive solid-phase extraction-dispersive liquid-liquid microextraction-derivatization for gas chromatography-mass spectrometric determination of aliphatic amines on atmospheric fine particles.

PubMed

Majedi, Seyed Mohammad; Lee, Hian Kee

2017-02-24

Short-chain aliphatic amines are ubiquitous in the atmospheric environment. They play an important role in the formation and growth of atmospheric particles. As such, there is a pressing need to monitor these particle-bound compounds present at trace quantities. The present work describes an efficient, one-step microextraction technique for the preconcentration and detection of trace levels of 10 aliphatic amines on fine particles (particulate matter of 2.5μm or less (PM 2.5 )) in the atmosphere. After extraction of amines from particles in acidified water samples, carbon-based sorbents (in dispersive solid-phase extraction mode), and vortex agitation were utilized for simultaneous derivatization-extraction and dispersive liquid-liquid microextraction. The approach significantly increased the recoveries and enrichment of the amine derivatives. This one-step, combined technique is proposed for the first time. Several influential factors including type and concentration of derivatization reagent (for gas chromatographic separation), type of buffer, sample pH, types and volumes of extraction and disperser solvents, type and amount of sorbent, vortex time and temperature, desorption solvent type and volume, and salt content were investigated and optimized. Under the optimum conditions, high enrichment factors (in the range of between 307 and 382) and good reproducibility (relative standard deviations, below 7.0%, n=5) were achieved. The linearity ranged from 0.1μg/L-100μg/L, and from 0.5μg/L-100μg/L, depending on the analytes. The limits of detection were between 0.02μg/L (corresponding to ∼0.01ng/m 3 in air) and 0.09μg/L (corresponding to ∼0.04ng/m 3 in air). The developed method was successfully applied to the analysis of PM 2.5 samples collected by air sampling through polytetrafluoroethylene filters. The concentration levels of amines ranged from 1.04 to 4.16ng/m 3 in the air sampled. Copyright © 2016 Elsevier B.V. All rights reserved.

Aerodynamic size distribution of suspended particulate matter in the ambient air in the city of Cleveland, Ohio

NASA Technical Reports Server (NTRS)

Leibecki, H. F.; King, R. B.; Fordyce, J. S.

1974-01-01

The City of Cleveland Division of Air Pollution Control and NASA jointly investigated the chemical and physical characteristics of the suspended particulate matter in Cleveland, and as part of the program, measurements of the particle size distribution of ambient air samples at five urban locations during August and September 1972 were made using high-volume cascade impactions. The distributions were evaluated for lognormality, and the mass median diameters were compared between locations and as a function of resultant wind direction. Junge-type distributions were consistent with dirty continental aerosols. About two-thirds of the suspended particulate matter observed in Cleveland is less than 7 microns in diameter.

Effects of particulate air pollution on the respiratory health of subjects who live in three areas in Kanpur, India.

PubMed

Sharma, Mukesh; Kumar, V Narendra; Katiyar, Subodh K; Sharma, Richa; Shukla, Bhanu P; Sengupta, Babu

2004-07-01

In this study, the authors assessed the relationship between daily changes in respiratory health and particulate levels with diameters of (a) less than 10 microm (PM10) and (b) less than 2.5 microm (PM2.5) in Kanpur, India. The subjects (N = 91) were recruited from 3 areas in Kanpur: (1) Indian Institute of Technology (Kanpur), which was a relatively clean area; (b) Vikas Nagar, a typical commercial area; and (c) finally, the residential area of Juhilal Colony. All subjects resided near to air quality monitoring sites. Air quality and peak expiratory flow rate samplings were conducted for 39 d. Once during the sampling period, lung-function tests (i.e., forced expiratory volume in 1 s, forced vital capacity) were performed on each subject. Subjects who resided at the clean site performed at predicted (i.e., acceptable) values more often than did subjects who lived at the remaining 2 sites. Subjects who lived at all 3 sites demonstrated a substantial average deficit in baseline forced vital capacity and forced expiratory volume in 1 s values. The authors used a statistical model to estimate that an increase of 100 microg/m3 of the pollutant PM10 could reduce the mean peak expiratory flow rate of an individual by approximately 3.2 l/min.

Department of Defense Survey of Living Conditions Overseas, 1984. Volume 1. Management Report.

DTIC Science & Technology

1985-07-01

Spouse Nationality, and Sex ............................. 1 Household Composition..............................................1I Spouse Employment and...Nationality, and Sex Army Air Force Only service members who had Germany 2770 United Kingdom 1996 dependents qualified to be sampled. Italy 710 Germany...number/ availability for teens and preteens , convenience to playgrounds - and youth centers; - Immediate physical-psychological surroundings, including

76 FR 15974 - Office of Research and Development; Ambient Air Monitoring Reference and Equivalent Methods...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-22

... on a particle filter. Because this new measurement approach is being approved for NAAQS compliance... Lead (Pb) on TSP High-Volume Filters.'' A sample of total suspended particulate matter (TSP) is collected on a glass fiber filter, using the sampler and procedure of the EPA Reference Method for the...

A Literature Review of Concentrations and Size Distributions of Ambient Airborne Pb-Containing Particulate Matter

EPA Science Inventory

The final 2008 lead (Pb) national ambient air quality standards (NAAQS) revision maintains Pb in total suspended particulate matter as the indicator. However, the final rule permits the use of low-volume PM₁₀ (particulate matter sampled with a 50% cut-point of 10 μm) F...

Social media as a sensor of air quality and public response in China.

PubMed

Wang, Shiliang; Paul, Michael J; Dredze, Mark

2015-03-26

Recent studies have demonstrated the utility of social media data sources for a wide range of public health goals, including disease surveillance, mental health trends, and health perceptions and sentiment. Most such research has focused on English-language social media for the task of disease surveillance. We investigated the value of Chinese social media for monitoring air quality trends and related public perceptions and response. The goal was to determine if this data is suitable for learning actionable information about pollution levels and public response. We mined a collection of 93 million messages from Sina Weibo, China's largest microblogging service. We experimented with different filters to identify messages relevant to air quality, based on keyword matching and topic modeling. We evaluated the reliability of the data filters by comparing message volume per city to air particle pollution rates obtained from the Chinese government for 74 cities. Additionally, we performed a qualitative study of the content of pollution-related messages by coding a sample of 170 messages for relevance to air quality, and whether the message included details such as a reactive behavior or a health concern. The volume of pollution-related messages is highly correlated with particle pollution levels, with Pearson correlation values up to .718 (n=74, P<.001). Our qualitative results found that 67.1% (114/170) of messages were relevant to air quality and of those, 78.9% (90/114) were a firsthand report. Of firsthand reports, 28% (32/90) indicated a reactive behavior and 19% (17/90) expressed a health concern. Additionally, 3 messages of 170 requested that action be taken to improve quality. We have found quantitatively that message volume in Sina Weibo is indicative of true particle pollution levels, and we have found qualitatively that messages contain rich details including perceptions, behaviors, and self-reported health effects. Social media data can augment existing air pollution surveillance data, especially perception and health-related data that traditionally requires expensive surveys or interviews.

Innovative flow controller for time integrated passive sampling using SUMMA canisters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simon, P.; Farant, J.P.; Cole, H.

1996-12-31

To restrict the entry of gaseous contaminants inside evacuated vessels such as SUMMA canisters, mechanical flow controllers are used to collect integrated atmospheric samples. From the passive force generated by the pressure gradient, the motion of gas can be controlled to obtain a constant flow rate. Presently, devices based on the principle of critical orifices are used and they are all limited to an upper integrated sampling time. A novel flow controller which can be designed to achieve any desired sampling time when used on evacuated vessels was recently developed. It can extend the sampling time for hours, days, weeksmore » or even months for the benefits of environmental, engineering and toxicological professionals. The design of the controller is obtained from computer simulations done with an original set of equations derived from fluid mechanic and gas kinetic laws. To date, the experimental results have shown excellent agreement, with predictions obtained from the mathematical model. This new controller has already found numerous applications. Units able to deliver a constant sampling rate between vacuum and approximately -10 inches Hg during continuous long term duration have been used with SUMMA canisters of different volumes (500 ml, 1 litre and 61). Essentially, any combination of sampling time and sampler volume is possible. The innovative flow controller has contributed to an air quality assessment around a sanitary landfill (indoor/outdoor), and inside domestic wastewater and pulpmill sludge treatment facilities. It is presently being used as an alternative methodology for atmospheric sampling in the Russian orbital station Mir. This device affords true long term passive monitoring of selected gaseous air pollutants for environmental studies. 14 refs., 3 figs.« less

Efficiencies of Tritium (3H) bubbling systems.

PubMed

Duda, Jean-Marie; Le Goff, Pierre; Leblois, Yoan; Ponsard, Samuel

2018-09-01

Bubbling systems are among the devices most used by nuclear operators to measure atmospheric tritium activity in their facilities or the neighbouring environment. However, information about trapping efficiency and bubbling system oxidation is not accessible and/or, at best, only minimally supported by demonstrations in actual operating conditions. In order to evaluate easily these parameters and thereby meet actual normative and regulatory requirements, a statistical study was carried out over 2000 monitoring records from the CEA Valduc site. From this data collection obtained over recent years of monitoring the CEA Valduc facilities and environment, a direct relation was highlighted between the 3H-samplers trapping efficiency of tritium as tritiated water and the sampling time and conditions of use: temperature and atmospheric moisture. It was thus demonstrated that this efficiency originated from two sources. The first one is intrinsic to the bubbling system operating parameters and the sampling time. That part applies equally to all four bubblers. The second part, however, is specific to the first bubbler. In essence, it depends on the sampling time and the sampled air characteristics. It was also highlighted that the water volume variation in the first bubbler, between the beginning and the end of the sampling process, is directly related to the average water concentration of the sampled air. In this way, it was possible to model the variations in trapping efficiency of the 3H-samplers relative to the sampling time and the water volume variation in the first bubbler. This model makes it possible to obtain the quantities required to comply with the current standards governing the monitoring of radionuclides in the environment and to associate an uncertainty concerning the measurements as well as the sampling parameters. Copyright © 2018 Elsevier Ltd. All rights reserved.

A multi-residue method for characterization and determination of atmospheric pesticides measured at two French urban and rural sampling sites.

PubMed

Baraud, Laurent; Tessier, Didier; Aaron, Jean-Jacques; Quisefit, Jean-Paul; Pinart, Johann

2003-12-01

The extensive use of pesticides to protect agricultural crops can result in the transfer of these compounds into the atmosphere and their diffusion towards urban areas. Precise evaluation of the geographic impact of this type of pollution is important environmentally. In this paper, analytical methods for the sampling, characterization, and determination of agricultural pesticides in air were developed; the methods were then applied in the Paris and Champagne regions. Sixteen pesticides belonging to nine chemical families were monitored. Sampling was carried out in urban (Paris) and rural (Aube district) sites, utilizing either a high-volume pump (12.5 m3 h(-1)) (urban site) or a low-volume pump (2.3 m3 h(-1)) for the rural site. Quartz filters and polyurethane foams (PUF) were used for sampling in all cases. After extracting the samples and concentrating the recovered solutions, high-performance liquid chromatography (HPLC) analysis with UV detection was performed. Identification of the pesticides was confirmed by applying to the HPLC measurements a novel UV-detection procedure based on the normalized absorbance variation with wavelength (Noravawa procedure). The presence of metsulfuron methyl, isoproturon, linuron, deltamethrin (and/or malathion), and chlorophenoxy acids (2,4-D and MCPP) was found at the urban sampling site at levels ranging from about 1 to 1130 ng m(-3) of air, depending on the compound and sampling period. On the rural sampling site residues of isoproturon, deltamethrin (and/or malathion), MCPP, and 2,4-D were generally detected at higher levels (19-5130 ng m(-3)) than on the urban site, as expected. The effects of the weather conditions and agricultural activity on the atmospheric concentrations of pesticides are discussed, as are long-range atmospheric transfer processes for these pesticides.

Conditions for superconductivity in the electron-doped copper-oxide system, (Nd 1-xCe x) 2CuO 4+δ

NASA Astrophysics Data System (ADS)

Tanaka, Y.; Motohashi, T.; Karppinen, M.; Yamauchi, H.

2008-02-01

We report systematic studies on the relations among the Ce IV-for-Nd III substitution level ( x), oxygen-partial pressure ( P), oxygen content (4+ δ), lattice parameters ( a, c) and superconductivity characteristics ( Tc, volume fraction) in the (Nd 1-xCe x) 2Cu 1-yO 4+δ system which includes electron-doped superconductors. Independent of the Ce-doping level x, samples synthesized in air are found oxygen deficient, i.e. δ<0. Nevertheless, reductive annealing is needed to induce superconductivity in the air-synthesized samples. At the same time, the amount of oxygen removed upon the annealing is found very small (e.g. 0.004 oxygen atoms per formula unit at x=0.075), and consequently the effect of the annealing on the valence of copper (and thereby also on the electron doping level) is insignificant. Rather, the main function of the reductive annealing is likely to repair the Cu vacancies believed to exist in tiny concentrations ( y) in the air-synthesized samples.

Measurement of toxic volatile organic compounds in indoor air of semiconductor foundries using multisorbent adsorption/thermal desorption coupled with gas chromatography-mass spectrometry.

PubMed

Wu, Chien-Hou; Lin, Ming-Nan; Feng, Chien-Tai; Yang, Kuang-Ling; Lo, Yu-Shiu; Lo, Jiunn-Guang

2003-05-09

A method for the qualitative and quantitative analysis of volatile organic compounds (VOCs) in the air of class-100 clean rooms at semiconductor fabrication facilities was developed. Air samples from two semiconductor factories were collected each hour on multisorbent tubes (including Carbopack B, Carbopack C, and Carbosieve SIII) with a 24-h automatic active sampling system and analyzed using adsorption/thermal desorption coupled with gas chromatography-mass spectrometry. Experimental parameters, including thermal desorption temperature, desorption time, and cryofocusing temperature, were optimized. The average recoveries and the method detection limits for the target compounds were in the range 94-101% and 0.31-0.89 ppb, respectively, under the conditions of a 1 L sampling volume and 80% relative humidity. VOCs such as acetone, isopropyl alcohol, 2-heptanone, and toluene, which are commonly used in the semiconductor and electronics industries, were detected and accurately quantified with the established method. Temporal variations of the analyte concentrations observed were attributed to the improper use of organic solvents during operation.

Characterization of polyurethane foam (PUF) and sorbent impregnated PUF (SIP) disk passive air samplers for measuring organophosphate flame retardants.

PubMed

Abdollahi, Atousa; Eng, Anita; Jantunen, Liisa M; Ahrens, Lutz; Shoeib, Mahiba; Parnis, J Mark; Harner, Tom

2017-01-01

This study aimed to characterize the uptake of organophosphate esters (OPEs) by polyurethane foam (PUF) and sorbent-impregnated polyurethane foam (SIP) disk passive air samplers (PAS). Atmospheric OPE concentrations were monitored with high-volume active air samplers (HV-AAS) that were co-deployed with passive air samplers. Samples were analyzed for tris(2-chloroisopropyl) phosphate (TCIPP), tri(phenyl) phosphate (TPhP), tris(2-chloroethyl) phosphate (TCEP), and tris(2,3-dichloropropyl) phosphate (TDCIPP). The mean concentration of ∑OPEs in air was 2650 pg/m 3 for the HV-AAS. Sampling rates and the passive sampler medium (PSM)-air partition coefficient (K PSM-Air ) were calculated for individual OPEs. The average calculated sampling rates (R) for the four OPEs were 3.6 ± 1.2 and 4.2 ± 2.0 m 3 /day for the PUF and SIP disks, respectively, and within the range of the recommended default value of 4 ± 2 m 3 /day. Since most of the OPEs remained in the linear uptake phase during the study, COSMO-RS solvation theory and an oligomer-based model were used to estimate K PUF-Air for the OPEs. The estimated values of log K PUF-Air were 7.45 (TCIPP), 9.35 (TPhP), 8.44 (TCEP), and 9.67 (TDCIPP). Finally, four configurations of the PUF and SIP disks were tested by adjusting the distance of the gap opening between the upper and lower domes of the sampler housing: i.e. 2 cm, 1 cm, no gap and 1 cm overlap. The sampling rate did not differ significantly between these four configurations (p < 0.05). Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

The Development of the improved equipment for the measurement radionuclides of xenon in atmospheric air

NASA Astrophysics Data System (ADS)

Pakhomov, S. A.; Dubasov, Y. V.

2009-04-01

The Radium Khlopin Institute have developed the mobile (vehicle based) equipment attended for the providing of the monitoring of radioactive xenon isotopes in atmospheric air on territories, neighboring with NPP. This equipment comprises the improved sampling installation with sample-processing unit and specialized spectrometer of β-γ-coincidences. The principal specificity of sampling installation is the using of the gas-cooling machine attended for the reaching of the cryogenic temperatures, which works without helium, using for cooling the processed air itself. The capacity of sampling reaches 20 cubic meters per hour with the xenon extraction factor of 75%. The duration of the sampling cycle forms 3 - 7 hours depending of the xenon volume requirements. The sample-processing unit is designed on preparative gas chromatograph scheme. Duration of sample-processing procedure does not exceed one and half hour. The volume of the prepared sample is around half liter, it contains 3 - 7 cubic centimeters of the xenon, depending of sampling cycle time. For measurements of xenon radioisotopes containing in obtained sample, was developed a β-γ-coincidences spectrometer on the base of the "ORTEC" HP Ge detector equipped with scintillation β-detector designed as Marinelli chamber of 700 cm3 volume. This spectrometer allows to reduce the ambient background more than in 20 times, with γ-channel efficiency reduction not more than in 1.5 times. The minimum detectable activity of 133Хе (MDA), evaluated by Currie formula for probability 95 % is 0.05 Bq at the exposition of 20 hours. Spectrometer is also intended for determination of the stable krypton and xenon concentrations in β-chamber by X-ray-fluorescent method. Therefore, in a shield of the spectrometer collimating pinhole is made and 241Am source is installed. To improve the sensitivity of the analysis beryllium window is made in β-chamber wall, adjoining to the HPGe detector. X-ray-fluorescent analysis allows to surely define Xe volumetric concentration of 0.05% in β-cell, that is equivalent less then 0,5 cm3 of Xe. The first approbation of described equipment was fulfilled in St. Petersburg at autumn of 2007 year and have shown that the spectrometer allows to measure 133Xe concentration at the level of 2 mBq/m3, and this value is in a good agreement with the results of other measurements. Described equipment was practically approbated in field conditions on 2008 year during the expeditionary work carryout in Sosnovyi Bor, Udomlya and Polyarnie Zori - the cities of North-West of Russia, which are located in close neighboring with acting NPP.

Induced Environment Contamination Monitor (IECM), air sampler - Results from the Space Transport System (STS-2) flight

NASA Technical Reports Server (NTRS)

Peters, P. N.; Hester, H. B.; Bertsch, W.; Mayfield, H.; Zatko, D.

1983-01-01

An investigation involving sampling the rapidly changing environment of the Shuttle cargo bay is considered. Four time-integrated samples and one rapid acquisition sample were collected to determine the types and quantities of contaminants present during ascent and descent of the Shuttle. The sampling times for the various bottles were controlled by valves operated by the Data Acquisition and Control System (DACS) of the IECM. Many of the observed species were found to be common solvents used in cleaning surfaces. When the actual volume sampled is taken into account, the relative mass of organics sampled during descent is about 20 percent less than during ascent.

Calibration of two passive air samplers for monitoring phthalates and brominated flame-retardants in indoor air.

PubMed

Saini, Amandeep; Okeme, Joseph O; Goosey, Emma; Diamond, Miriam L

2015-10-01

Two passive air samplers (PAS), polyurethane foam (PUF) disks and Sorbent Impregnated PUF (SIP) disks, were characterized for uptake of phthalates and brominated flame-retardants (BFRs) indoors using fully and partially sheltered housings. Based on calibration against an active low-volume air sampler for gas- and particle-phase compounds, we recommend generic sampling rates of 3.5±0.9 and 1.0±0.4 m(3)/day for partially and fully sheltered housing, respectively, which applies to gas-phase phthalates and BFRs as well as particle-phase DEHP (the later for the partially sheltered PAS). For phthalates, partially sheltered SIPs are recommended. Further, we recommend the use of partially sheltered PAS indoors and a deployment period of one month. The sampling rate for the partially sheltered PUF and SIP of 3.5±0.9 m(3)/day is indistinguishable from that reported for fully sheltered PAS deployed outdoors, indicating the role of the housing outdoors to minimize the effect of variable wind velocities on chemical uptake, versus the partially sheltered PAS deployed indoors to maximize chemical uptake where air flow rates are low. Copyright © 2015. Published by Elsevier Ltd.

The relationship between air layers and evaporative resistance of male Chinese ethnic clothing.

PubMed

Wang, Faming; Peng, Hui; Shi, Wen

2016-09-01

In this study, the air layer distribution and evaporative resistances of 39 sets of male Chinese ethnic clothing were investigated using a sweating thermal manikin and the three-dimensional (3D) body scanning technique. Relationships between the evaporative resistance and air layers (i.e., air gap thickness and air volume) were explored. The results demonstrated that the clothing total evaporative resistance increases with the increasing air gap size/air volume, but the rate of increase gradually decreases as the mean air gap size or the total air volume becomes larger. The clothing total evaporative resistance reaches its maximum when the average air gap size and the total air volume are 41.6 mm and 69.9 dm(3), respectively. Similar general trends were also found between local mean air gap size and clothing local evaporative resistance at different body parts. However, different body parts show varied rates of increase and decrease in the local evaporative resistance. The research findings provide a comprehensive database for predicting overall and local human thermal comfort while wearing male Chinese ethnic clothing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical characterization of ambient aerosol collected during the southwest monsoon and intermonsoon seasons over the Arabian Sea: Labile-Fe(II) and other trace metals

NASA Astrophysics Data System (ADS)

Siefert, Ronald L.; Johansen, Anne M.; Hoffmann, Michael R.

1999-02-01

Atmospheric deposition of iron (Fe) to certain regions of the oceans is an important nutrient source of Fe to the biota, and the ability of the biota to uptake Fe is dependent on the speciation of the Fe. Therefore understanding the speciation of Fe in the atmosphere is critical to understanding the role of Fe as a nutrient source in surface ocean waters. Labile ferrous iron (Fe(II)) concentrations as well as total concentrations for Fe and other important trace metals, cations, and anions were determined over the Arabian Sea for two nonconsecutive months during 1995. Ambient aerosol samples were collected during the Indian Ocean intermonsoon and southwest monsoon seasons over the Arabian Sea. Sampling took place aboard the German research vessel Meteor in the months of May (leg M32/3; intermonsoon) and July/August (leg M32/5; southwest monsoon). Both cruise tracks followed the 65th east meridian, traveling for 30 days each (from north to south during leg M32/3 and from south to north during leg M32/5). A high-volume dichotomous virtual impactor with an aerodynamic cutoff size of 3 μm was used to collect the fine and coarse aerosol fractions for metal analysis. A low volume collector was used to collect aerosol samples for anion and cation analysis. The analysis for labile-Fe(II) was done immediately after sample collection to minimize any possible Fe redox reactions which might occur during sample storage. The analytical procedure involved filter extraction in a formate/formic acid buffered solution at pH 4.2 followed by colorimetric quantification of soluble Fe(II). Metals, anions, and cations were analyzed after the cruise. Total atmospheric aqueous-labile-Fe(II) concentrations during the intermonsoon were between 4.75 and <0.4 ng m-3, of which most (>80%) was present in the fine fraction (<3.0 μm). During the southwest monsoon, atmospheric aqueous-labile-Fe(II) concentrations were consistently below the detection limit (<0.34 to <0.089 ng m-3, depending on the volume of air sampled). Air mass back trajectories (5 day, three dimensional) showed that air masses sampled during the southwest monsoon had advected over the open Indian Ocean, while air masses sampled during the intermonsoon had advected over northeast Africa, the Saudi Arabian peninsula, and southern Asia. These calculations were consistent with the results of the statistical analysis performed on the data set which showed that the variance due to crustal species during the intermonsoon samples was greater than the variance due to crustal species during the southwest monsoon. The factor scores for the crustal components were also greater when the back trajectories had advected over the nearby continental masses. Principal component analysis was also performed with the intermonsoon samples where aqueous labile Fe(II) was above the detection limit. Aqueous labile Fe(II) did not correlate well with other species indicating possible atmospheric processing of the iron during advection.

Semivolatile Endocrine-Disrupting Compounds in Paired Indoor and Outdoor Air in Two Northern California Communities

PubMed Central

2010-01-01

Interest in the health effects of potential endocrine-disrupting compounds (EDCs) that are high production volume chemicals used in consumer products has made exposure assessment and source identification a priority. We collected paired indoor and outdoor air samples in 40 nonsmoking homes in urban, industrial Richmond, CA, and 10 in rural Bolinas, CA. Samples were analyzed by GC-MS for 104 analytes, including phthalates (11), alkylphenols (3), parabens (3), polybrominated diphenyl ether (PBDE) flame retardants (3), polychlorinated biphenyls (PCBs) (3), polycyclic aromatic hydrocarbons (PAHs) (24), pesticides (38), and phenolic compounds (19). We detected 39 analytes in outdoor air and 63 in indoor air. For many of the phenolic compounds, alkylphenols, phthalates, and PBDEs, these represent some of the first outdoor measures and the first analysis of the relative importance of indoor and outdoor sources in paired samples. Data demonstrate higher indoor concentrations for 32 analytes, suggesting primarily indoor sources, as compared with only 2 that were higher outdoors. Outdoor air concentrations were higher in Richmond than Bolinas for 3 phthalates, 10 PAHs, and o-phenylphenol, while indoor air levels were more similar between communities, except that differences observed outdoors were also seen indoors. Indoor concentrations of the most ubiquitous chemicals were generally correlated with each other (4-t-butylphenol, o-phenylphenol, nonylphenol, several phthalates, and methyl phenanthrenes; Kendall correlation coefficients 0.2−0.6, p < 0.05), indicating possible shared sources and highlighting the importance of considering mixtures in health studies. PMID:20681565

US EPA's National Dioxin Air Monitoring Network: Analytical ...

EPA Pesticide Factsheets

The U.S. EPA has established a National Dioxin Air Monitoring Network (NDAMN) to determine the temporal and geographical variability of atmospheric chlorinated dibenzo-p-dioxins (CDDs), furans (CDFs), and coplanar polychlorinated biphenyls (PCBs) at rural and non-impacted locations throughout the United States. Currently operating at 32 sampling stations, NDAMN has three primary purposes: (1) to determine the atmospheric levels and occurrences of dioxin-like compounds in rural and agricultural areas where livestock, poultry, and animal feed crops are grown; (2) to provide measurements of atmospheric levels in different geographic regions of the U.S.; and (3) to provide information regarding the long-range transport of dioxin-like compounds in air over the U.S. Designed in 1997, NDAMN has been implemented in phases, with the first phase consisting of 9 monitoring stations and is achieving congener-specific detection lmits of 0.1 fg/m3 for 2,3,7,8-TCDD and 10 fg/m3 for OCDD. With respect to coplanar PCBs, the detection limits are generally higher due to the presence of background levels in the air during the preparation and processing of the samples. Achieving these extremely low levels of detection present a host of analytical issues. Among these issues are the methods used to establish ultra-trace detection limits, measures to ensure against and monitor for breakthrough of native analytes when sampling large volumes of air, and procedures for handling and e

Evaluation of the particle infiltration efficiency of three passive samplers and the PS-1 active air sampler

NASA Astrophysics Data System (ADS)

Markovic, Milos Z.; Prokop, Sebastian; Staebler, Ralf M.; Liggio, John; Harner, Tom

2015-07-01

The particle infiltration efficiencies (PIE) of three passive and one active air samplers were evaluated under field conditions. A wide-range particle spectrometer operating in the 250-4140 nm range was used to acquire highly temporally resolved particle-number and size distributions for the different samplers compared to ambient air. Overall, three of the four evaluated samplers were able to acquire a representative sample of ambient particles with PIEs of 91.5 ± 13.7% for the GAPS Network sampler, 103 ± 15.5% for the Lancaster University sampler, and 89.6 ± 13.4% for a conventional PS-1 high-volume active air sampler (Hi-Vol). Significantly (p = 0.05) lower PIE of 54 ± 8.0% was acquired for the passive sampler used under the MONET program. These findings inform the comparability and use of passive and active samplers for measuring particle-associated priority chemicals in air.

Inactivation of RNA Viruses by Gamma Irradiation: A Study on Mitigating Factors

PubMed Central

Hume, Adam J.; Ames, Joshua; Rennick, Linda J.; Duprex, W. Paul; Marzi, Andrea; Tonkiss, John; Mühlberger, Elke

2016-01-01

Effective inactivation of biosafety level 4 (BSL-4) pathogens is vital in order to study these agents safely. Gamma irradiation is a commonly used method for the inactivation of BSL-4 viruses, which among other advantages, facilitates the study of inactivated yet morphologically intact virions. The reported values for susceptibility of viruses to inactivation by gamma irradiation are sometimes inconsistent, likely due to differences in experimental protocols. We analyzed the effects of common sample attributes on the inactivation of a recombinant vesicular stomatitis virus expressing the Zaire ebolavirus glycoprotein and green fluorescent protein. Using this surrogate virus, we found that sample volume and protein content of the sample modulated viral inactivation by gamma irradiation but that air volume within the sample container and the addition of external disinfectant surrounding the sample did not. These data identify several factors which alter viral susceptibility to inactivation and highlight the usefulness of lower biosafety level surrogate viruses for such studies. Our results underscore the need to validate inactivation protocols of BSL-4 pathogens using “worst-case scenario” procedures to ensure complete sample inactivation. PMID:27455307

Chemical characterization and toxicity of particulate matter emissions from roadside trash combustion in urban India

NASA Astrophysics Data System (ADS)

Vreeland, Heidi; Schauer, James J.; Russell, Armistead G.; Marshall, Julian D.; Fushimi, Akihiro; Jain, Grishma; Sethuraman, Karthik; Verma, Vishal; Tripathi, Sachi N.; Bergin, Michael H.

2016-12-01

Roadside trash burning is largely unexamined as a factor that influences air quality, radiative forcing, and human health even though it is ubiquitously practiced across many global regions, including throughout India. The objective of this research is to examine characteristics and redox activity of fine particulate matter (PM2.5) associated with roadside trash burning in Bangalore, India. Emissions from smoldering and flaming roadside trash piles (n = 24) were analyzed for organic and elemental carbon (OC/EC), brown carbon (BrC), and toxicity (i.e. redox activity, measured via the dithiothreitol "DTT" assay). A subset of samples (n = 8) were further assessed for toxicity by a cellular assay (macrophage assay) and also analyzed for trace organic compounds. Results show high variability of chemical composition and toxicity between trash-burning emissions, and characteristic differences from ambient samples. OC/EC ratios for trash-burning emissions range from 0.8 to 1500, while ambient OC/EC ratios were observed at 5.4 ± 1.8. Trace organic compound analyses indicate that emissions from trash-burning piles were frequently composed of aromatic di-acids (likely from burning plastics) and levoglucosan (an indicator of biomass burning), while the ambient sample showed high response from alkanes indicating notable representation from vehicular exhaust. Volume-normalized DTT results (i.e., redox activity normalized by the volume of air pulled through the filter during sampling) were, unsurprisingly, extremely elevated in all trash-burning samples. Interestingly, DTT results suggest that on a per-mass basis, fresh trash-burning emissions are an order of magnitude less redox-active than ambient air (13.4 ± 14.8 pmol/min/μgOC for trash burning; 107 ± 25 pmol/min/μgOC for ambient). However, overall results indicate that near trash-burning sources, exposure to redox-active PM can be extremely high.

High tidal volume ventilation induces NOS2 and impairs cAMP- dependent air space fluid clearance.

PubMed

Frank, James A; Pittet, Jean-Francois; Lee, Hyon; Godzich, Micaela; Matthay, Michael A

2003-05-01

Tidal volume reduction during mechanical ventilation reduces mortality in patients with acute lung injury and the acute respiratory distress syndrome. To determine the mechanisms underlying the protective effect of low tidal volume ventilation, we studied the time course and reversibility of ventilator-induced changes in permeability and distal air space edema fluid clearance in a rat model of ventilator-induced lung injury. Anesthetized rats were ventilated with a high tidal volume (30 ml/kg) or with a high tidal volume followed by ventilation with a low tidal volume of 6 ml/kg. Endothelial and epithelial protein permeability were significantly increased after high tidal volume ventilation but returned to baseline levels when tidal volume was reduced. The basal distal air space fluid clearance (AFC) rate decreased by 43% (P < 0.05) after 1 h of high tidal volume but returned to the preventilation rate 2 h after tidal volume was reduced. Not all of the effects of high tidal volume ventilation were reversible. The cAMP-dependent AFC rate after 1 h of 30 ml/kg ventilation was significantly reduced and was not restored when tidal volume was reduced. High tidal volume ventilation also increased lung inducible nitric oxide synthase (NOS2) expression and air space total nitrite at 3 h. Inhibition of NOS2 activity preserved cAMP-dependent AFC. Because air space edema fluid inactivates surfactant and reduces ventilated lung volume, the reduction of cAMP-dependent AFC by reactive nitrogen species may be an important mechanism of clinical ventilator-associated lung injury.

Unvented kerosene-heater emissions in mobile homes: Studies on indoor air particles, semivolatile organics, carbon monoxide, and mutagenicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumford, J.L.; Lewtas, J.; Burton, R.M.

1990-01-01

The study was conducted to assess human exposure to air pollutants resulting from the use of kerosene heaters in mobile homes. It has been estimated that 15-17 million unvented kerosene heaters have been sold in the United States, and 33% of these heaters have been sold to mobile home residents. The emissions from kerosene heaters can result in high pollutants levels in mobile homes that have a small air volume and low ventilation rate. Indoor air exchange rate, temperature, and humidity were measured. Chemical analyses, including polycyclic aromatic hydrocarbon (PAH) and nitro PAH, also were performed on the indoor airmore » samples from a selected home with the kerosene heater on and off. Increases in CO and organic concentrations resulting from the use of kerosene heaters were found in most homes monitored. Chemical analysis data also suggested the presence of evaporated, unburned kerosene fuel present in semivolatile organics collected in the XAD samples. When kerosene heaters were on, 56% of the sampling days (in all homes) showed dose-response mutagenic activity and 19% showed mutagenic activity on the heater-off days. In comparison with the U.S. national ambient air standards, four out of the eight heaters investigated in this study emitted pollutants that exceeded the ambient air standards some days. These data suggested that emissions from unvented kerosene heaters can significantly impact indoor air quality in mobile homes and that these emissions contain carcinogenic compounds and can be potentially carcinogenic in humans.« less

Using Isotope Ratio Infrared Spectrometer to determine δ13C and δ18O of carbonate samples

NASA Astrophysics Data System (ADS)

Smajgl, Danijela; Stöbener, Nils; Mandic, Magda

2017-04-01

The isotopic composition of calcifying organisms is a key tool for reconstruction past seawater temperature and water chemistry. Therefore stable carbon and oxygen isotopes (δ13C and δ18O) in carbonates have been widely used for reconstruction of paleoenvironments. Precise and accurate determination of isotopic composition of carbon (13C) and oxygen (18O) from carbonate sample with proper referencing and data evaluation algorithm presents a challenge for scientists. Mass spectrometry was the only widely used technique for this kind of analysis, but recent advances make laser based spectroscopy a viable alternative. The Thermo Scientific Delta Ray Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect is one of those alternatives and with TELEDYNE Cetac ASX-7100 autosampler extends the traditional offerings with a system of high precision and throughput of samples. To establish precision and accuracy of measurements and also to develop optimal sample preparation method for measurements with Delta Ray IRIS and URI Connect, IAEA reference materials were used. Preparation is similar to a Gas Bench II method. Carbonate material is added into the vials, flushed with CO2 free synthetic air and acidified with few droplets of 104% H3PO4. Sample amount used for analysis can be as low as 200 μg. Samples are measured after acidification and equilibration time of one hour at 70°C. The CO2 gas generated by reaction is flushed into the variable volume inside the URI Connect through the Nafion based built-in water trap. For this step, carrier gas (CO2 free air) is used to flush the gas from the vial into the variable volume with a maximum volume of 100 ml. A small amount of the sample is then used for automatic concentration determination present in the variable volume. The Thermo Scientific Qtegra Software automatically adjusts any additional dilution of the sample to achieve the desired concentration (usually 400 ppm) in the analyzer. As part of the workflow, reference gas measurements are regularly measured at the same concentration as the sample to allow for automatic drift and linearity correction. With described sample preparation and measurement method, samples are measured with standard deviation less than 0.1‰ δ13C and δ18O, respectively and accuracy of <0.01‰. The system can measure up to 100 samples per day. Equivalent of about 80 µg of pure CO2 gas is needed to complete an analysis. Due to it's small weight and robustness, sample analysis can be performed in the field. Applying new technology of Isotope Ratio Infrared Spectrometers in environmental and paleoenvironmental research can extend the knowledge of complex seawater history and CO2 cycle.

Survey of polyfluorinated chemicals (PFCs) in the atmosphere over the northeast Atlantic Ocean

NASA Astrophysics Data System (ADS)

Shoeib, Mahiba; Vlahos, Penny; Harner, Tom; Peters, Andrew; Graustein, Margaret; Narayan, Julie

2010-08-01

High volume air sampling in Bermuda, Sable Island (Nova Scotia) and along a cruise track from the Gulf of Mexico to northeast coast of the USA, was carried out to assess air concentrations, particle-gas partitioning and transport of polyfluorinated chemicals (PFCs) in this region. Samples were collected in the summer of 2007. Targeted compounds included the neutral PFCs: fluorotelomer alcohols (FTOHs), perfluoroalkyl sulfonamides (FOSAs) and perfluoroalkyl sulfonamido ethanols (FOSEs). Among the FTOHs, 8:2 FTOH was dominant in all samples. Sum of the concentration of FTOHs (gas+particle phase) were higher in Bermuda (mean, 34 pg m -3) compared to Sable Island (mean, 16 pg m -3). In cruise samples, sum of FTOHs were highly variable (mean, 81 pg m -3) reflecting contributions from land-based sources in the northeast USA with concentrations reaching as high as 156 pg m -3. Among the FOSAs and FOSEs, MeFOSE was dominant in all samples. In Bermuda, levels of MeFOSE were exceptionally high (mean, 62 pg m -3), exceeding the FTOHs. Sable Island samples also exhibited the dominance of MeFOSE but at a lower concentration (mean, 15 pg m -3). MeFOSE air concentrations (pg m -3) in cruise samples ranged from 1.6 to 73 and were not linked to land-based sources. In fact high concentrations of MeFOSE observed in Bermuda were associated with air masses that originated over the Atlantic Ocean. The partitioning to particles for 8:2 FTOH, 10:2 FTOH, MeFOSE and EtFOSE ranged from as high as 15 to 42% for cruise samples to 0.9 to 14% in Bermuda. This study provides key information for validating and developing partitioning and transport models for the PFCs.

Evaluation of a Dust Control for a Small Slab-Riding Dowel Drill for Concrete Pavement

PubMed Central

Echt, Alan; Mead, Kenneth

2016-01-01

Purpose To assess the effectiveness of local exhaust ventilation to control respirable crystalline silica exposures to acceptable levels during concrete dowel drilling. Approach Personal breathing zone samples for respirable dust and crystalline silica were collected while laborers drilled holes 3.5 cm diameter by 36 cm deep in a concrete slab using a single-drill slab-riding dowel drill equipped with local exhaust ventilation. Data were collected on air flow, weather, and productivity. Results All respirable dust samples were below the 90 µg detection limit which, when combined with the largest sample volume, resulted in a minimum detectable concentration of 0.31 mg m−3. This occurred in a 32-min sample collected when 27 holes were drilled. Quartz was only detected in one air sample; 0.09 mg m−3 of quartz was found on an 8-min sample collected during a drill maintenance task. The minimum detectable concentration for quartz in personal air samples collected while drilling was performed was 0.02 mg m−3. The average number of holes drilled during each drilling sample was 23. Over the course of the 2-day study, air flow measured at the dust collector decreased from 2.2 to 1.7 m3 s−1. Conclusions The dust control performed well under the conditions of this test. The initial duct velocity with a clean filter was sufficient to prevent settling, but gradually fell below the recommended value to prevent dust from settling in the duct. The practice of raising the drill between each hole may have prevented the dust from settling in the duct. A slightly higher flow rate and an improved duct design would prevent settling without regard to the position of the drill. PMID:26826033

Evaluation of a Dust Control for a Small Slab-Riding Dowel Drill for Concrete Pavement.

PubMed

Echt, Alan; Mead, Kenneth

2016-05-01

To assess the effectiveness of local exhaust ventilation to control respirable crystalline silica exposures to acceptable levels during concrete dowel drilling. Personal breathing zone samples for respirable dust and crystalline silica were collected while laborers drilled holes 3.5 cm diameter by 36 cm deep in a concrete slab using a single-drill slab-riding dowel drill equipped with local exhaust ventilation. Data were collected on air flow, weather, and productivity. All respirable dust samples were below the 90 µg detection limit which, when combined with the largest sample volume, resulted in a minimum detectable concentration of 0.31 mg m(-3). This occurred in a 32-min sample collected when 27 holes were drilled. Quartz was only detected in one air sample; 0.09 mg m(-3) of quartz was found on an 8-min sample collected during a drill maintenance task. The minimum detectable concentration for quartz in personal air samples collected while drilling was performed was 0.02 mg m(-3). The average number of holes drilled during each drilling sample was 23. Over the course of the 2-day study, air flow measured at the dust collector decreased from 2.2 to 1.7 m(3) s(-1). The dust control performed well under the conditions of this test. The initial duct velocity with a clean filter was sufficient to prevent settling, but gradually fell below the recommended value to prevent dust from settling in the duct. The practice of raising the drill between each hole may have prevented the dust from settling in the duct. A slightly higher flow rate and an improved duct design would prevent settling without regard to the position of the drill. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2016.

Asleep Deep Brain Stimulation Reduces Incidence of Intracranial Air during Electrode Implantation.

PubMed

Ko, Andrew L; Magown, Philippe; Ozpinar, Alp; Hamzaoglu, Vural; Burchiel, Kim J

2018-05-30

Asleep deep brain stimulation (aDBS) implantation replaces microelectrode recording for image-guided implantation, shortening the operative time and reducing cerebrospinal fluid egress. This may decrease pneumocephalus, thus decreasing brain shift during implantation. To compare the incidence and volume of pneumocephalus during awake (wkDBS) and aDBS procedures. A retrospective review of bilateral DBS cases performed at Oregon Health & Science University from 2009 to 2017 was undertaken. Postimplantation imaging was reviewed to determine the presence and volume of intracranial air and measure cortical brain shift. Among 371 patients, pneumocephalus was noted in 66% of wkDBS and 15.6% of aDBS. The average volume of air was significantly higher in wkDBS than aDBS (8.0 vs. 1.8 mL). Volumes of air greater than 7 mL, which have previously been linked to brain shift, occurred significantly more frequently in wkDBS than aDBS (34 vs 5.6%). wkDBS resulted in significantly larger cortical brain shifts (5.8 vs. 1.2 mm). We show that aDBS reduces the incidence of intracranial air, larger air volumes, and cortical brain shift. Large volumes of intracranial air have been correlated to shifting of brain structures during DBS procedures, a variable that could impact accuracy of electrode placement. © 2018 S. Karger AG, Basel.

USAF Summer Research Program - 1993 Graduate Student Research Program Final Reports, Volume 8, Phillips Laboratory

DTIC Science & Technology

1994-12-01

Research Program Phillips Laboratory Kirtland Air Force Base Albuquerque, New Mexico Sponsored by: Air ...Summer Research Program Phillips Laboratory Sponsored by. Air Force Office of Scientific Research Kirtland Air Force Base, Albuquerque, New Mexico...UNITED STATES AIR FORCE SUMMER RESEARCH PROGRAM -- 1993 SUMMER RESEARCH PROGRAM FINAL REPORTS VOLUME 8

Urine Monitoring System

NASA Technical Reports Server (NTRS)

Feedback, Daniel L.; Cibuzar, Branelle R.

2009-01-01

The Urine Monitoring System (UMS) is a system designed to collect an individual crewmember's void, gently separate urine from air, accurately measure void volume, allow for void sample acquisition, and discharge remaining urine into the Waste Collector Subsystem (WCS) onboard the International Space Station. The Urine Monitoring System (UMS) is a successor design to the existing Space Shuttle system and will resolve anomalies such as: liquid carry-over, inaccurate void volume measurements, and cross contamination in void samples. The crew will perform an evaluation of airflow at the ISS UMS urinal hose interface, a calibration evaluation, and a full user interface evaluation. o The UMS can be used to facilitate non-invasive methods for monitoring crew health, evaluation of countermeasures, and implementation of a variety of biomedical research protocols on future exploration missions.

Water content dependence of trapped air in two soils

USGS Publications Warehouse

Stonestrom, David A.; Rubin, Jacob

1989-01-01

An improved air pycnometer method was used to examine the water content dependence of trapped-air volumes in two repacked, nonswelling soils. Trapped-air volumes were determined at a series of hydrostatic equilibrium stages which were attained during water pressure-controlled wetting and drying cycles over a range of 0 to −10 kPa for a sand and 0 to −20 kPa for a loam. Small pressure perturbations, between 0.2 and 0.6 kPa, were used in the air pycnometer method. Volumes of trapped air obtained at each hydrostatic equilibrium stage were independent of perturbation level and remained relatively constant over the time required to make repeated determinations. In contrast with most of the results obtained in previous studies, which often showed irregular relations, in this study the volume fraction of trapped air was found to be a regular, monotonically increasing (though possibly hysteretic) function of water content. For the soils studied, the function definitely exceeded zero only at water contents greater than 70% of saturation. However, during the initial drying from complete water saturation, the volume fraction of trapped air was virtually zero. Air trapping influenced the water retention curves significantly only at water contents higher than about 60% of saturation. Except at zero water pressure, however, not all of the differences between the initial and the other drying retention curves were accounted for by observed differences in trapped-air volumes. Air trapping was not required for the onset of hysteresis in the water retention relation for the cases studied, i.e., when drying-to-wetting reversals were imposed at about 27% and 40% of saturation for the sand and loam soils, respectively.

Installation Restoration Program. Remedial Investigation Report. Minnesota Air National Guard Base Duluth International Airport, Duluth, Minnesota. Volume 5

DTIC Science & Technology

1990-01-01

1-20 1-6 Sites Defined and Ranked During IRP Phase I Study. 1-29 1-7 Aerial Photograph of Site 2, April 1988. 1-32 1-8 Site 2 Sampling Locations...Utilized During Phase II Investigations. 1-35 1-9 Aerial Photograph of Site 3, April 1988. 1-38 1-10 Site 3 Sampling Locations Utilized During Phase II...Investigations. 1-47 1-11 Aerial Photograph of Site 4, April 1988. 1-54 1-12 Site 4 Sampling Locations Utilized During Phase II Investigations. 1-57 1-13

Analytical procedure for the determination of very volatile organic compounds (C3-C6) in indoor air.

PubMed

Schieweck, Alexandra; Gunschera, Jan; Varol, Deniz; Salthammer, Tunga

2018-05-01

The substance group of very volatile organic compounds (VVOCs) is moving into the focus of indoor air analysis, facing ongoing regulations at international and European levels targeting on indoor air quality and human health. However, there exists at present no validated analysis for the identification and quantification of VVOCs in indoor air. Therefore, the present study targeted on the development of an analytical method in order to sample the maximum possible quantity of VVOCs in indoor air on solid sorbents with subsequent analysis by thermal desorption and coupled gas chromatography/mass spectrometry (TDS-GC/MS). For this purpose, it was necessary to investigate the performance of available sorbents and to optimize the parameters of GC/MS analysis. Stainless steel tubes filled with Carbograph 5TD were applied successfully for low-volume sampling (2-4 l) with minimal breakthrough (< 1%). With the developed method, VVOCs between C 3 and C 6 of different volatility and polarity  can be detected even in trace quantities with low limits of quantitation (LOQ; 1-3 μg m -3 ). Limitations occur for low molecular weight compounds ≤C 3 , especially for polar substances, such as carboxylic acids and for some aldehydes and alcohols. Consequently, established methods for the quantification of these compounds in indoor air cannot be fully substituted yet. At least three different analytical techniques are needed to cover the large spectrum of relevant VVOCs in indoor air. In addition, unexpected reaction products might occur and need to be taken into account to avoid misinterpretation of chromatographic signals. Graphical abstract Solid sorbent sampling of VVOCs (C 3 -C 6 ) in indoor air with subsequent TDS-GC/MS analysis.

Magnetic particles as liquid carriers in the microfluidic lab-in-tube approach to detect phase change.

PubMed

Blumenschein, Nicholas A; Han, Daewoo; Caggioni, Marco; Steckl, Andrew J

2014-06-11

Magnetic beads (MBs) with ∼1.9 μm average diameter were used to transport specific microliter-scale volumes of liquids between adjacent reservoirs within a closed tube under the influence of a magnetic field. The tube's inner surface is coated with a hydrophobic layer, enabling the formation of a surface tension valve by inserting an air gap between reservoirs. This transfer process was implemented by keeping the MBs stationary with a fixed external magnet while the liquid reservoirs were translated by a computer-controlled syringe pump system. The magnet induces the aggregation of MBs in a loosely packed cluster (void volume ∼90-95%) against the tube's inner wall. The liquid trapped in the MB cluster is transported across the air gap between reservoirs. Fluorescence intensity from a dye placed in one reservoir is used to measure the volume of liquid transferred between reservoirs. The carry-over liquid volume is controlled by the mass of the MBs within the device. The typical volume of liquid carried by the MB cluster is ∼2 to 3 μL/mg of beads, allowing the use of small samples. This technique can be used to study the effect of small compositional variation on the properties of fluid mixtures. The feasibility of this "lab-in-tube" approach for binary phase diagram determination in a water-surfactant (C12E5) system was demonstrated.

Registration-based assessment of regional lung function via volumetric CT images of normal subjects vs. severe asthmatics

PubMed Central

Choi, Sanghun; Hoffman, Eric A.; Wenzel, Sally E.; Tawhai, Merryn H.; Yin, Youbing; Castro, Mario

2013-01-01

The purpose of this work was to explore the use of image registration-derived variables associated with computed tomographic (CT) imaging of the lung acquired at multiple volumes. As an evaluation of the utility of such an imaging approach, we explored two groups at the extremes of population ranging from normal subjects to severe asthmatics. A mass-preserving image registration technique was employed to match CT images at total lung capacity (TLC) and functional residual capacity (FRC) for assessment of regional air volume change and lung deformation between the two states. Fourteen normal subjects and thirty severe asthmatics were analyzed via image registration-derived metrics together with their pulmonary function test (PFT) and CT-based air-trapping. Relative to the normal group, the severely asthmatic group demonstrated reduced air volume change (consistent with air trapping) and more isotropic deformation in the basal lung regions while demonstrating increased air volume change associated with increased anisotropic deformation in the apical lung regions. These differences were found despite the fact that both PFT-derived TLC and FRC in the two groups were nearly 100% of predicted values. Data suggest that reduced basal-lung air volume change in severe asthmatics was compensated by increased apical-lung air volume change and that relative increase in apical-lung air volume change in severe asthmatics was accompanied by enhanced anisotropic deformation. These data suggest that CT-based deformation, assessed via inspiration vs. expiration scans, provides a tool for distinguishing differences in lung mechanics when applied to the extreme ends of a population range. PMID:23743399

Comparison of air space measurement imaged by CT, small-animal CT, and hyperpolarized Xe MRI

NASA Astrophysics Data System (ADS)

Madani, Aniseh; White, Steven; Santyr, Giles; Cunningham, Ian

2005-04-01

Lung disease is the third leading cause of death in the western world. Lung air volume measurements are thought to be early indicators of lung disease and markers in pharmaceutical research. The purpose of this work is to develop a lung phantom for assessing and comparing the quantitative accuracy of hyperpolarized xenon 129 magnetic resonance imaging (HP 129Xe MRI), conventional computed tomography (HRCT), and highresolution small-animal CT (μCT) in measuring lung gas volumes. We developed a lung phantom consisting of solid cellulose acetate spheres (1, 2, 3, 4 and 5 mm diameter) uniformly packed in circulated air or HP 129Xe gas. Air volume is estimated based on simple thresholding algorithm. Truth is calculated from the sphere diameters and validated using μCT. While this phantom is not anthropomorphic, it enables us to directly measure air space volume and compare these imaging methods as a function of sphere diameter for the first time. HP 129Xe MRI requires partial volume analysis to distinguish regions with and without 129Xe gas and results are within %5 of truth but settling of the heavy 129Xe gas complicates this analysis. Conventional CT demonstrated partial-volume artifacts for the 1mm spheres. μCT gives the most accurate air-volume results. Conventional CT and HP 129Xe MRI give similar results although non-uniform densities of 129Xe require more sophisticated algorithms than simple thresholding. The threshold required to give the true air volume in both HRCT and μCT, varies with sphere diameters calling into question the validity of thresholding method.

Determining Atmospheric Pressure with a Eudiometer and Glycerol

ERIC Educational Resources Information Center

Brody, Jed; Rohald, Kate; Sutton, Atasha

2010-01-01

We consider a volume of air trapped over a glycerol column in a eudiometer. We demonstrate that there is an approximately linear relationship between the volume of trapped air and the height of the glycerol column. Simply by moving the eudiometer up and down, we cause the glycerol-column height and trapped-air volume to vary. The plot of volume…

SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS RECOVERY BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

EPA Science Inventory

Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

SOURCE SAMPLING FINE PARTICULATE MATTER: A KRAFT PROCESS HOGGED FUEL BOILER AT A PULP AND PAPER FACILITY, VOLUMES 1 AND 2

EPA Science Inventory

Fine particulate matter of aerodynamic diameter 2.5 m or less (PM-2.5) has been found harmful to human health, and a National Ambient Air Quality Standard for PM-2.5 was promulgated by the U.S. Environmental Protection Agency in July 1997. A national network of ambient monitorin...

Indoor air quality in public buildings. Volume 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheldon, L.; Zelon, H.; Sickles, J.

Two separate but closely related studies of exposures to volatile organic compounds (VOCs) in buildings where people spend long periods of time were conducted. This report summarizes results obtained in six buildings: a new hospital, office and nursing home and another office, office/school, and nursing home. At each building sampling was performed at three indoor locations and a single outdoor location.

Optimizing laboratory-based radon flux measurements for sediments.

PubMed

Chanyotha, Supitcha; Kranrod, Chutima; Kritsananuwat, Rawiwan; Lane-Smith, Derek; Burnett, William C

2016-07-01

Radon flux via diffusion from sediments and other materials may be determined in the laboratory by circulating air through the sample and a radon detector in a closed loop. However, this approach is complicated by the necessity of having to determine the total air volume in the system and accounting for any small air leaks that can arise if using extended measurement periods. We designed a simple open-loop configuration that includes a measured mass of wet sediment and water inside a gas-tight reaction flask connected to a drying system and a radon-in-air analyzer. Ambient air flows through two charcoal columns before entering the reaction vessel to eliminate incoming radon. After traveling through the reaction flask, the air passes the drier and the radon analyzer and is then vented. After some time, the radon activity will reach a steady state depending upon the airflow rate. With this approach, the radon flux via diffusion is simply the product of the steady-state radon activity (Bq/m(3)) multiplied by the airflow rate (mL/min). We demonstrated that this setup could produce good results for materials that produce relatively high radon fluxes. We also show that a modified closed system approach, including radon removal of the incoming air by charcoal filtration in a bypass, can produce very good results including samples with very low emission rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement and estimated health risks of semivolatile organic compounds (PCBs, PAHs, pesticides, and phthalates) in ambient air at the Hanford Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patton, G.W.; Cooper, A.T.; Blanton, M.L.

1997-09-01

Air samples for polychlorinated biphenyls (PCBs), chlorinated pesticides, phthalate plasticizers, and polycyclic aromatic hydrocarbons (PAHs) were collected at three Hanford Site locations (300-Area South Gate, southeast of 200-East Area, and a background location near Rattlesnake Springs). Samples were collected using high-volume air samplers equipped with a glass fiber filter and polyurethane foam plug sampling train. Target compounds were extracted from the sampling trains and analyzed using capillary gas chromatography with either electron capture detection or mass selective detection. Twenty of the 28 PCB congeners analyzed were found above the detection limits, with 8 of the congeners accounting for over 80%more » of the average PCB concentrations. The average sum of all individual PCB congeners ranged from 500-740 pg/m{sup 3}, with little apparent difference between the sampling locations. Twenty of the 25 pesticides analyzed were found above the detection limits, with endosulfan I, endosulfan II, and methoxychlor having the highest average concentrations. With the exception of the endosulfans, all other average pesticide concentrations were below 100 pg/m{sup 3}. There was little apparent difference between the air concentrations of pesticides measured at each location. Sixteen of the 18 PAHs analyzed were found above the detection limit. Phenanthrene, fluoranthene, pyrene, fluorene, chrysene, benzo(b)fluoranthene, and naphthalene were the only PAHs with average concentrations above 100 pg/m{sup 3}. Overall, the 300 Area had higher average PAH concentrations compared to the 200-East Area and the background location at Rattlesnake Springs; however, the air concentrations at the 300-Area also are influenced by sources on the Hanford Site and from nearby communities.« less

An adaptive maneuvering logic computer program for the simulation of one-on-one air-to-air combat. Volume 1: General description

NASA Technical Reports Server (NTRS)

Burgin, G. H.; Fogel, L. J.; Phelps, J. P.

1975-01-01

A technique for computer simulation of air combat is described. Volume 1 decribes the computer program and its development in general terms. Two versions of the program exist. Both incorporate a logic for selecting and executing air combat maneuvers with performance models of specific fighter aircraft. In the batch processing version the flight paths of two aircraft engaged in interactive aerial combat and controlled by the same logic are computed. The realtime version permits human pilots to fly air-to-air combat against the adaptive maneuvering logic (AML) in Langley Differential Maneuvering Simulator (DMS). Volume 2 consists of a detailed description of the computer programs.

Synthesis and Mass Spectrometric Characterization of Organic Nitrates

NASA Astrophysics Data System (ADS)

Grünert, A.; Woidich, S.; Ballschmiter, K.

2003-04-01

Organic nitrates, as trace constituents in urban air, can be analyzed by adsorptive low volume sampling (LVS) as well as by adsorptive high volume sampling (HVS). Air samples ranging from 25 L to 100 L for the LVS and 100 m3 to 500 m3 for the (HVS) were collected, respectively. Analysis is performed by thermodesorption (LVS) or solvent elution combined with group separation (HVS) using normal-phase HPLC and high resolution capillary gas chromatography with electron capture detection (HRGC-ECD) and mass selective detection (HRGC-MSD). For identification and quantification available reference compounds are required for both methods (1;2). Following numbers of congeners of organic nitrate have been synthesized: 77 monoalkyl nitrates (C1-C16), 43 dialkyl nitrates (C2-C10), 37 hydroxy alkyl nitrates (C2-C8) and 41 carbonyl alkyl nitrates (C3-C12). Alkanes, alkenes, alcohols, ketones and halocarbons have been used as precursors. Characterisation of the reference compounds by retention-data and mass-spectra was performed by high resolution capillary gas chromatography with mass selective detection in the EI- and the NCI (CH4) mode (1-3). EI-ionization leads to the dominating indicator ion NO2+ for organic nitrates with m/z = 46 u. The characteristic fragments with NCI (CH4) show ions at m/z = 46 u and m/z = 62 u, corresponding to NO2- and NO3-. The use of flame ionisation detection (HRGC-FID) and the principle of the molar response for carbon allows the quantitation of reference solutions as the final tool for the determination of the levels and patterns of organic nitrates in urban air samples. (1) J. Kastler: "Analytik, Massenspektrometrie und Vorkommen multifunktioneller Alkylnitrate in belasteter und unbelasteter Atmosphäre" Dr.rer.nat.-Thesis, University of Ulm (1999) (2) G. Werner, J. Kastler, R. Looser, K. Ballschmiter: "Organic Nitrates of Isoprenes as Atmospheric Trace Compounds" Angew. Chem. Int. Ed. (1999) 38(11): 1634-1637 (3) S.Woidich, O. Froscheis, O. Luxenhofer, K. Ballschmiter: "EI- and NCI-mass spectrometry of aryl-alkyl nitrates and their occurrence in urban air" Fresenius J Anal Chem (1999) 364: 91-99

EVALUATION OF THE REAL-TIME AIR-QUALITY MODEL USING THE RAPS (REGIONAL AIR POLLUTION STUDY) DATA BASE. VOLUME 1. OVERVIEW

EPA Science Inventory

The theory and programming of statistical tests for evaluating the Real-Time Air-Quality Model (RAM) using the Regional Air Pollution Study (RAPS) data base are fully documented in four report volumes. Moreover, the tests are generally applicable to other model evaluation problem...

The Analysis for Energy Consumption of Marine Air Conditioning System Based on VAV and VWV

NASA Astrophysics Data System (ADS)

Xu, Sai Feng; Yang, Xing Lin; Le, Zou Ying

2018-06-01

For ocean-going vessels sailing in different areas on the sea, the change of external environment factors will cause frequent changes in load, traditional ship air-conditioning system is usually designed with a fixed cooling capacity, this design method causes serious waste of resources. A new type of sea-based air conditioning system is proposed in this paper, which uses the sea-based source heat pump system, combined with variable air volume, variable water technology. The multifunctional cabins' dynamic loads for a ship navigating in a typical Eurasian route were calculated based on Simulink. The model can predict changes in full voyage load. Based on the simulation model, the effects of variable air volume and variable water volume on the energy consumption of the air-conditioning system are analyzed. The results show that: When the VAV is coupled with the VWV, the energy saving rate is 23.2%. Therefore, the application of variable air volume and variable water technology to marine air conditioning systems can achieve economical and energy saving advantages.

Solid phase microextraction Arrow for the sampling of volatile amines in wastewater and atmosphere.

PubMed

Helin, Aku; Rönkkö, Tuukka; Parshintsev, Jevgeni; Hartonen, Kari; Schilling, Beat; Läubli, Thomas; Riekkola, Marja-Liisa

2015-12-24

A new method is introduced for the sampling of volatile low molecular weight alkylamines in ambient air and wastewater by utilizing a novel SPME Arrow system, which contains a larger volume of sorbent compared to a standard SPME fiber. Parameters affecting the extraction, such as coating material, need for preconcentration, sample volume, pH, stirring rate, salt addition, extraction time and temperature were carefully optimized. In addition, analysis conditions, including desorption temperature and time as well as gas chromatographic parameters, were optimized. Compared to conventional SPME fiber, the SPME Arrow had better robustness and sensitivity. Average intermediate reproducibility of the method expressed as relative standard deviation was 12% for dimethylamine and 14% for trimethylamine, and their limit of quantification 10μg/L and 0.13μg/L respectively. Working range was from limits of quantification to 500μg/L for dimethylamine and to 130μg/L for trimethylamine. Several alkylamines were qualitatively analyzed in real samples, while target compounds dimethyl- and trimethylamines were quantified. The concentrations in influent and effluent wastewater samples were almost the same (∼80μg/L for dimethylamine, 120μg/L for trimethylamine) meaning that amines pass the water purification process unchanged or they are produced at the same rate as they are removed. For the air samples, preconcentration with phosphoric acid coated denuder was required and the concentration of trimethylamine was found to be around 1ng/m(3). The developed method was compared with optimized method based on conventional SPME and advantages and disadvantages of both approaches are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Ambient concentrations of total suspended particulate matter and its elemental constituents at the wider area of the mining facilities of TVX Hellas in Chalkidiki, Greece.

PubMed

Gaidajis, George

2003-01-01

To assess ambient air quality at the wider area of TVX Hellas mining facilities, the Total Suspended Particulate matter (TSP) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn are being monitored for more than thirty months as part of the established Environmental Monitoring Program. High Volume air samplers equipped with Tissue Quartz filters were employed for the collection of TSP. Analyses were effected after digestion of the suspended particulate with an HNO3-HCl solution and determination of elemental concentrations with an Atomic Absorption Spectroscopy equipped with graphite furnace. The sampling stations were selected to record representatively the existing ambient air quality in the vicinity of the facilities and at remote sites not affected from industrial activities. Monitoring data indicated that the background TSP concentrations ranged from 5-60 microg/m3. Recorded TSP concentrations at the residential sites close to the facilities ranged between 20-100 microg/m3, indicating only a minimal influence from the mining and milling activities. Similar spatial variation was observed for the TSP constituents and specifically for Pb and Zn. To validate the monitoring procedures, a parallel sampling campaign took place with different High Volume samplers at days where low TSP concentrations were expected. The satisfactory agreement (+/- 11%) at low concentrations (50-100 microg/m3) clearly supported the reproducibility of the techniques employed specifically at the critical range of lower concentrations.

Long-term observation of water-soluble chemical components in the bulk atmospheric aerosols collected at Okinawa, Japan

NASA Astrophysics Data System (ADS)

Handa, Daishi; Somada, Yuka; Ijyu, Moriaki; Azechi, Sotaro; Nakaema, Fumiya; Arakaki, Takemitsu; Tanahara, Akira

2010-05-01

The economic development and population growth in recent Asia spread air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. The study of the long-range transported air pollution from Asian continent has gained a special attention in Japan because of increase in photochemical oxidants in relatively remote islands. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location in Asia is well suited for studying long-range transport of air pollutants in East Asia because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background and can be compared with continental air masses which have been affected by anthropogenic activities. Bulk aerosol samples were collected on quartz filters by using a high volume air sampler. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations and dissolved organic carbon (DOC) in the bulk aerosols collected at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS) using ion chromatography, atomic absorption spectrometry, and total organic carbon analyzer, respectively. We will report water-soluble chemical components data of anions, cations and DOC in bulk atmospheric aerosols collected at CHAAMS during August, 2005 to April, 2010. Seasonal variation of water-soluble chemical components showed that the concentrations were relatively low in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian Continent, the concentrations of water-soluble chemical components were much higher compared to the other directions. In addition, we calculated background concentration of water-soluble chemical components at Okinawa, Japan.

Food animal transport: a potential source of community exposures to health hazards from industrial farming (CAFOs).

PubMed

Rule, Ana M; Evans, Sean L; Silbergeld, Ellen K

2008-01-01

Use of antimicrobial feed additives in food animal production is associated with selection for drug resistance in bacterial pathogens, which can then be released into the environment through occupational exposures, high volume ventilation of animal houses, and land application of animal wastes. We tested the hypothesis that current methods of transporting food animals from farms to slaughterhouses may result in pathogen releases and potential exposures of persons in vehicles traveling on the same road. Air and surface samples were taken from cars driving behind poultry trucks for 17 miles. Air conditioners and fans were turned off and windows fully opened. Background and blank samples were used for quality control. Samples were analyzed for susceptible and drug-resistant strains. Results indicate an increase in the number of total aerobic bacteria including both susceptible and drug-resistant enterococci isolated from air and surface samples, and suggest that food animal transport in open crates introduces a novel route of exposure to harmful microorganisms and may disseminate these pathogens into the general environment. These findings support the need for further exposure characterization, and attention to improving methods of food animal transport, especially in highly trafficked regions of high density farming such as the Delmarva Peninsula.

Dynamic planar solid phase microextraction-ion mobility spectrometry for rapid field air sampling and analysis of illicit drugs and explosives.

PubMed

Guerra-Diaz, Patricia; Gura, Sigalit; Almirall, José R

2010-04-01

A preconcentration device that targets the volatile chemical signatures associated with illicit drugs and explosives (high and low) has been designed to fit in the inlet of an ion mobility spectrometer (IMS). This is the first reporting of a fast and sensitive method for dynamic sampling of large volumes of air using planar solid phase microextraction (PSPME) incorporating a high surface area for absorption of analytes onto a sol-gel polydimethylsiloxane (PDMS) coating for direct thermal desorption into an IMS. This device affords high extraction efficiencies due to strong retention properties at ambient temperature, resulting in the detection of analyte concentrations in the parts per trillion range when as low as 3.5 L of air are sampled over the course of 10 s (absolute mass detection of less than a nanogram). Dynamic PSPME was used to sample the headspace over the following: 3,4-methylenedioxymethamphetamine (MDMA) tablets resulting in the detection of 12-40 ng of piperonal, high explosives (Pentolite) resulting in the detection of 0.6 ng of 2,4,6-trinitrotoluene (TNT), and low explosives (several smokeless powders) resulting in the detection of 26-35 ng of 2,4-dinitrotoluene (2,4-DNT) and 11-74 ng of diphenylamine (DPA).

Development of analysis of volatile polyfluorinated alkyl substances in indoor air using thermal desorption-gas chromatography-mass spectrometry.

PubMed

Wu, Yaoxing; Chang, Victor W-C

2012-05-18

The study attempts to utilize thermal desorption (TD) coupled with gas chromatography-mass spectrometry (GC-MS) for determination of indoor airborne volatile polyfluorinated alkyl substances (PFASs), including four fluorinated alcohols (FTOHs), two fluorooctane sulfonamides (FOSAs), and two fluorooctane sulfonamidoethanols (FOSEs). Standard stainless steel tubes of Tenax/Carbograph 1 TD were employed for low-volume sampling and exhibited minimal breakthrough of target analytes in sample collection. The method recoveries were in the range of 88-119% for FTOHs, 86-138% for FOSAs, exhibiting significant improvement compared with other existing air sampling methods. However, the widely reported high method recoveries of FOSEs were also observed (139-210%), which was probably due to the structural differences between FOSEs and internal standards. Method detection limit, repeatability, linearity, and accuracy were reported as well. The approach has been successfully applied to routine quantification of targeted PFASs in indoor environment of Singapore. The significantly shorter sampling time enabled the observation of variations of concentrations of targeted PFASs within different periods of a day, with higher concentration levels at night while ventilation systems were shut off. This indicated the existence of indoor sources and the importance of building ventilation and air conditioning system. Copyright © 2012 Elsevier B.V. All rights reserved.

Deformability measurement of red blood cells using a microfluidic channel array and an air cavity in a driving syringe with high throughput and precise detection of subpopulations.

PubMed

Kang, Yang Jun; Ha, Young-Ran; Lee, Sang-Joon

2016-01-07

Red blood cell (RBC) deformability has been considered a potential biomarker for monitoring pathological disorders. High throughput and detection of subpopulations in RBCs are essential in the measurement of RBC deformability. In this paper, we propose a new method to measure RBC deformability by evaluating temporal variations in the average velocity of blood flow and image intensity of successively clogged RBCs in the microfluidic channel array for specific time durations. In addition, to effectively detect differences in subpopulations of RBCs, an air compliance effect is employed by adding an air cavity into a disposable syringe. The syringe was equally filled with a blood sample (V(blood) = 0.3 mL, hematocrit = 50%) and air (V(air) = 0.3 mL). Owing to the air compliance effect, blood flow in the microfluidic device behaved transiently depending on the fluidic resistance in the microfluidic device. Based on the transient behaviors of blood flows, the deformability of RBCs is quantified by evaluating three representative parameters, namely, minimum value of the average velocity of blood flow, clogging index, and delivered blood volume. The proposed method was applied to measure the deformability of blood samples consisting of homogeneous RBCs fixed with four different concentrations of glutaraldehyde solution (0%-0.23%). The proposed method was also employed to evaluate the deformability of blood samples partially mixed with normal RBCs and hardened RBCs. Thereafter, the deformability of RBCs infected by human malaria parasite Plasmodium falciparum was measured. As a result, the three parameters significantly varied, depending on the degree of deformability. In addition, the deformability measurement of blood samples was successfully completed in a short time (∼10 min). Therefore, the proposed method has significant potential in deformability measurement of blood samples containing hematological diseases with high throughput and precise detection of subpopulations in RBCs.

Evaluation and guidelines for using polyurethane foam (PUF) passive air samplers in double-dome chambers to assess semi-volatile organic compounds (SVOCs) in non-industrial indoor environments.

PubMed

Bohlin, Pernilla; Audy, Ondřej; Škrdlíková, Lenka; Kukučka, Petr; Vojta, Šimon; Přibylová, Petra; Prokeš, Roman; Čupr, Pavel; Klánová, Jana

2014-11-01

Indoor air pollution has been recognized as an important risk factor for human health, especially in areas where people tend to spend most of their time indoors. Many semi-volatile organic compounds (SVOCs) have primarily indoor sources and are present in orders of magnitude higher concentrations indoors than outdoors. Despite this, awareness of SVOCs in indoor air and assessment of the link between indoor concentrations and human health have lagged behind those of outdoor air. This is partially related to challenges associated with indoor sampling of SVOCs. Passive air samplers (PASs), which are widely accepted in established outdoor air monitoring networks, have been used to fill the knowledge gaps on indoor SVOCs distribution. However, their applicability for indoor environments and the assessment of human health risks lack sufficient experimental data. To address this issue, we performed an indoor calibration study of polyurethane foam (PUF) PAS deployed in a double-dome chamber, covering both legacy and new SVOC classes. PUF-PAS and a continuous low-volume active air sampler (AAS) were co-deployed for a calibration period of twelve weeks. Based on the results from this evaluation, PUF-PAS in a double-bowl chamber is recommended for indoor sampling and health risk assessment of gas phase SVOCs, including novel brominated flame retardants (nBFR) providing sufficient exposure time is applied. Data for particle associated SVOCs suffered from significant uncertainties caused by low level of detection and low precision in this study. A more open chamber design for indoor studies may allow for higher sampling rates (RS) and better performance for the particle associated SVOCs.

Development of an Atmospheric Dispersion Model for Heavier-Than-Air Gas Mixtures. Volume 1.

DTIC Science & Technology

1985-05-01

aspirated concentration sensor used a balanced Wheatstone bridge to measure the heat loss from a sensing element placed in the sample stream. Shaded...a semipermeable membrane and electrochemical cell. A fast response sensor (10 Hz) basically aspirated a sample past the cell membrane. Reported...ramp function around the freezing point of water by X11., X= vap for T 273.15 K vap fus 263.15 for 263.15 <T < 273.15 Xvap +x fus for T < 263.15 (A-4

Compliance Testing of Grissom AFB Central Heating Plant Coal-Fired Boilers 3, 4, and 5, Grissom AFB, Indiana

DTIC Science & Technology

1989-06-01

to a common breeching and can be routed to the wet -scrubber or to a bypass stack. The scrubber is a double-alkali flue - gas desulfurization system...the ambient air Bw. = proportion by volume of water vapor in F, = a factor representing a ratio of the vol. the stack gas . ume of wet flue gases...Scrubbers and Bypass Stacks 4 3 Flue Gas Flow Diagram 5 4 ORSAT Sampling Train 8 5 ORSAT Apparatus 8 6 Particulate Sampling Train 9 Table 1 Emission

United States Air Force Summer Research Program -- 1993. Volume 8. Phillips Laboratory

DTIC Science & Technology

1993-12-01

Research Program Phillips Laboratory Kirtland Air Force Base Albuquerque. New Mexico Sponsored by...Best Available Copy UNITED STATES AIR FORCE SUMMER RESEARCH PROGRAM -- 1993 SUMMER RESEARCH PROGRAM FINAL REPORTS VOLUME 8 PHILLIPS LABORATORY ...Alabama Box 870344 Tuscaloosa, AL 35487-0344 Final Report for: Graduate Student Research Program Phillips Laboratory , Hanscom AFB Sponsored by: Air

EVALUATION OF THE REAL-TIME AIR-QUALITY MODEL USING THE RAPS (REGIONAL AIR POLLUTION STUDY) DATA BASE. VOLUME 3. PROGRAM USER'S GUIDE

EPA Science Inventory

The theory and programming of statistical tests for evaluating the Real-Time Air-Quality Model (RAM) using the Regional Air Pollution Study (RAPS) data base are fully documented in four volumes. Moreover, the tests are generally applicable to other model evaluation problems. Volu...

EVALUATION OF THE REAL-TIME AIR-QUALITY MODEL USING THE RAPS (REGIONAL AIR POLLUTION STUDY) DATA BASE. VOLUME 4. EVALUATION GUIDE

EPA Science Inventory

The theory and programming of statistical tests for evaluating the Real-Time Air-Quality Model (RAM) using the Regional Air Pollution Study (RAPS) data base are fully documented in four volumes. Moreover, the tests are generally applicable to other model evaluation problems. Volu...

78 FR 15114 - Group Lotus plc; Grant of Petition for a Temporary Exemption From an Advanced Air Bag Requirement...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-08

... went into effect, low volume manufacturers now have access to advanced air bag technology. Accordingly, NHTSA has concluded that the expense of advanced air bag technology is not now sufficient, in and of... into effect, low volume manufacturers now have access to advanced air bag technology.\\14\\ Accordingly...

Solar powered dehumidifier apparatus

DOEpatents

Jebens, Robert W.

1980-12-30

A thermally insulated light transmitting housing forms a chamber containing a desiccant and having a first gas port open to the ambient and a second gas port connected by a two way valve to a volume to be dried. Solar energy transmitted through the housing heats and dries the desiccant. The increased air pressure due to the heating of the volume to be dried causes the air from the volume to be expelled through the valve into the chamber. The desiccant is then cooled by shielding it from solar energy before the volume cools thereby increasing its moisture absorbing capacity. Then the volume is allowed to cool drawing dehumidified air through the desiccant and the valve into the volume to be dried. This cycle is then repeated.

Installation Restoration Program. Site Investigation Report. Volume 1. 152nd Tactical Reconnaissance Group, Nevada Air National Guard, Reno Cannon International Airport, Reno, Nevada

DTIC Science & Technology

1994-04-01

measure RRI - Rapid Response Initiative RT - retention time s - seconds SDG - sample delivery group I SI - site investigation SMCLS - secondary maximum...tape and a compass and each grid node was marked with a wooden stake or fluorescent orange paint. At least one point on the grid was surveyed so the

Cavitation Inception in Separated Flows.

DTIC Science & Technology

1981-12-01

measured data. Keller (1972, 1973) determined the nuclei population by using a single particle light scattering device (the sample volume was... computations of the average pressure coefficient. The amount of air dissolved in the water varied from 10 to 11 ppm ( molar ) and was measured with a Van Slyke...fluctuating pressures were also measured. .-The conditions for cavitation inception and desinence were determined and several holograms were recorded

A positive chemical ionization GC/MS method for the determination of airborne ethylene glycol and propylene glycols in non-occupational environments.

PubMed

Zhu, Jiping; Feng, Yong-Lai; Aikawa, Bio

2004-11-01

An analytical method for ethylene glycol and propylene glycols has been developed for measuring airborne levels of these chemicals in non-occupational environments such as residences and office buildings. The analytes were collected on charcoal tubes, solvent extracted, and analyzed by gas chromatography-mass spectrometry using a positive chemical ionization technique. The method had a method detection limit of 0.07 microg m(-3) for ethylene glycol and 0.03 microg m(-3) for 1,2- and 1,3-propylene glycols, respectively, based on a 1.44 m3 sampling volume. Indoor air samples of several residential homes and other indoor environments have been analyzed. The median concentrations of ethylene glycol and 1,2-propylene glycol in nine residential indoor air samples were 53 microg m(-3) and 13 microg m(-3) respectively with maximum values of 223 microg m(-3) and 25 microg m(-3) detected for ethylene glycol and 1,2-propylene glycol respectively. The concentrations of these two chemicals in one office and two laboratories were at low microg m(-3) levels. The maximum concentration of 1,3-propylene glycol detected in indoor air was 0.1 microg m(-3).

Software for Experimental Air-Ground Data Link Volume I : Functional Description and Flowcharts.

DOT National Transportation Integrated Search

1975-10-01

Experimental Data Link System which was implemented for flight test during the Air-Ground Data Link Development Program (FAA-TSC Project Number FA-13). : The software development is presented in three volumes as follows: : Volume I: -- Functional Des...

Dielectric properties of lung tissue as a function of air content.

PubMed

Nopp, P; Rapp, E; Pfützner, H; Nakesch, H; Ruhsam, C

1993-06-01

Dielectric measurements were made on lung samples with different electrode systems in the frequency range 5 kHz-100 kHz. In the case of plate electrodes and spot electrodes, the effects of electrode polarization were partly corrected. An air filling factor F is defined, which is determined from the mass and volume of the sample. The results indicate that the electrical properties of lung tissue are highly dependent on the condition of the tissue. Furthermore they show that the conductivity sigma as well as the relative permittivity epsilon r decreases with increasing F. This is discussed using histological material. Using a simple theoretical model, the decrease of sigma and epsilon r is explained by the thinning of the alveolar walls as well as by the deformation of the epithelial cells and blood vessels through the expansion of the alveoli.

Thermocouple psychrometry

USGS Publications Warehouse

Andraski, Brian J.; Scanlon, Bridget R.; Dane, Jacob H.; Topp, G. Clarke

2002-01-01

Thermocouple psychrometry is a technique that infers the water potential of the liquid phase of a sample from measurements within the vapor phase that is in equilibrium with the sample. The theoretical relation between water potential of the liquid phase and relative humidity of the vapor phase is given by the Kelvin equation Ψ = energy/volume = (RT/Vw) ln(p/po) [3.2.3–1]where ψ is water potential (sum of matric and osmotic potential, MPa), R is the universal gas constant (8.314 × 10-6 MJ mol-1 K-1), T is temperature (K), Vw is molar volume of water (1.8 × 10-5 m3 mol-1), and p/po is relative humidity expressed as a fraction where p is actual vapor pressure of air in equilibrium with the liquid phase (MPa) and po is saturation vapor pressure (MPa) at T.

Improved particle impactor assembly for size selective high volume air sampler

DOEpatents

Langer, G.

1987-03-23

Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented apertures of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind, the relatively larger particles and passes through two elongate apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. By appropriate selection of dimensions and the number of inlet apertures air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the inlet apertures, to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks. 6 figs.

Testing of high-volume sampler inlets for the sampling of atmospheric radionuclides.

PubMed

Irshad, Hammad; Su, Wei-Chung; Cheng, Yung S; Medici, Fausto

2006-09-01

Sampling of air for radioactive particles is one of the most important techniques used to determine the nuclear debris from a nuclear weapon test in the Earth's atmosphere or those particles vented from underground or underwater tests. Massive-flow air samplers are used to sample air for any indication of radionuclides that are a signature of nuclear tests. The International Monitoring System of the Comprehensive Nuclear Test Ban Treaty Organization includes seismic, hydroacoustic, infrasound, and gaseous xenon isotopes sampling technologies, in addition to radionuclide sampling, to monitor for any violation of the treaty. Lovelace Respiratory Research Institute has developed a large wind tunnel to test the outdoor radionuclide samplers for the International Monitoring System. The inlets for these samplers are tested for their collection efficiencies for different particle sizes at various wind speeds. This paper describes the results from the testing of two radionuclide sampling units used in the International Monitoring System. The possible areas of depositional wall losses are identified and the losses in these areas are determined. Sampling inlet type 1 was tested at 2.2 m s wind speed for 5, 10, and 20-microm aerodynamic diameter particles. The global collection efficiency was about 87.6% for 10-microm particles for sampling inlet type 1. Sampling inlet type 2 was tested for three wind speeds at 0.56, 2.2, and 6.6 m s for 5, 10, and 20-microm aerodynamic diameter particles in two different configurations (sampling head lowered and raised). The global collection efficiencies for these configurations for 10-microm particles at 2.2 m s wind speed were 77.4% and 82.5%, respectively. The sampling flow rate was 600 m h for both sampling inlets.

Indoor air in schools and lung function of Austrian school children.

PubMed

Wallner, Peter; Kundi, Michael; Moshammer, Hanns; Piegler, Kathrin; Hohenblum, Philipp; Scharf, Sigrid; Fröhlich, Marina; Damberger, Bernhard; Tappler, Peter; Hutter, Hans-Peter

2012-07-01

The Children's Environment and Health Action Plan for Europe (CEHAPE) of WHO focuses (inter alia) on improving indoor environments where children spend most of their time. At present, only little is known about air pollution in schools and its effect on the lung function of school children. Our project was set up as an Austrian contribution to CEHAPE. In a cross-sectional approach, differences in indoor pollution in nine elementary all-day schools were assessed and 34 of these pollutants were analyzed for a relationship with respiratory health determined by spirometry using a linear regression model. Overall 596 children (aged 6-10 years) were eligible for the study. Spirometry was performed in 433 children. Socio-economic status, area of living (urban/rural), and smoking at home were included in the model as potential confounders with school-related average concentration of air pollutants as the variable of primary interest. A negative association with flow volumes (MEF(75)) was found for formaldehyde in air samples, benzylbutylphthalate and the sum of polybrominated diphenylethers in school dust. FVC and FEV(1) were negatively associated with ethylbenzene and xylenes in air samples and tris(1,3-dichlor-2-propyl)-phosphate on particulates. Although, in general, the quality of school indoor air was not worse than that reported for homes, effects on the respiratory health of children cannot be excluded. A multi-faceted strategy to improve the school environment is needed.

Reduce oil and grease content in wastewater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capps, R.W.; Matelli, G.N.; Bradford, M.L.

Poor water quality is often blamed on biological oxidation unit malfunction. However, poorly treated water entering the bio-unit is more often the problem. At the microscopic level, oil/water-separation dynamics are influenced by pH, fluid velocity, temperature, and unit volumes. Oily water's physical and chemical properties affect pretreatment systems such as API separators, corrugated plate interception (CPI) separators, air flotation and equalization systems. A better understanding of pretreatment systems' limits and efficiencies can improve wastewater quality before it upsets the biological oxidation (BIOX). Oil contamination in refinery wastewater originates from desalting, steam stripping, product treating, tank drains, sample drains and equipmentmore » washdown. The largest volumetric contributors are cooling tower blowdowns and contaminated stormwater. The paper describes the BIOX process; oil/water separation; oil/water emulsions and colloidal solutions; air flotation; surfactants; DAF (dissolved air flotation) process; IAF (induced air flotation) process; equalization; load factors; salts; and system design.« less

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.

Laser-induced incandescence calibration via gravimetric sampling

NASA Technical Reports Server (NTRS)

Choi, M. Y.; Vander Wal, R. L.; Zhou, Z.

1996-01-01

Absolute calibration of laser-induced incandescence (LII) is demonstrated via comparison of LII signal intensities with gravimetrically determined soot volume fractions. This calibration technique does not rely upon calculated or measured optical characteristics of soot. The variation of the LII signal with gravimetrically measured soot volume fractions ranging from 0.078 to 1.1 ppm established the linearly of the calibration. With the high spatial and temporal resolution capabilities of laser-induced incandescence (LII), the spatial and temporal fluctuations of the soot field within a gravimetric chimney were characterized. Radial uniformity of the soot volume fraction, f(sub v) was demonstrated with sufficient averaging of the single laser-shot LII images of the soot field thus confirming the validity of the calibration method for imaging applications. As illustration, instantaneous soot volume fractions within a Re = 5000 ethylene/air diffusion flame measured via planar LII were established quantitatively with this calibration.

Reversibility of trapped air on chest computed tomography in cystic fibrosis patients.

PubMed

Loeve, Martine; Rosenow, Tim; Gorbunova, Vladlena; Hop, Wim C J; Tiddens, Harm A W M; de Bruijne, Marleen

2015-06-01

To investigate changes in trapped air volume and distribution over time and compare computed tomography (CT) with pulmonary function tests for determining trapped air. Thirty children contributed two CTs and pulmonary function tests over 2 years. Localized changes in trapped air on CT were assessed using image analysis software, by deforming the CT at timepoint 2 to match timepoint 1, and measuring the volume of stable (TAstable), disappeared (TAdisappeared) and new (TAnew) trapped air as a proportion of total lung volume. We used the difference between total lung capacity measured by plethysmography and helium dilution, residual volume to total lung capacity ratio, forced expiratory flow at 75% of vital capacity, and maximum mid-expiratory flow as pulmonary function test markers of trapped air. Statistical analysis included Wilcoxon's signed rank test and Spearman correlation coefficients. Median (range) age at baseline was 11.9 (5-17) years. Median (range) of trapped air was 9.5 (2-33)% at timepoint 1 and 9.0 (0-25)% at timepoint 2 (p=0.49). Median (range) TAstable, TAdisappeared and TAnew were respectively 3.0 (0-12)%, 5.0 (1-22)% and 7.0 (0-20)%. Trapped air on CT correlated statistically significantly with all pulmonary function measures (p<0.01), other than residual volume to total lung capacity ratio (p=0.37). Trapped air on CT did not significantly progress over 2 years, may have a substantial stable component, and is significantly correlated with pulmonary function markers. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 7. System Cost.

DOT National Transportation Integrated Search

1973-02-01

The volume presents estimates of the federal government and user costs for the Satellite-Based Advanced Air Traffic Management System and the supporting rationale. The system configuration is that presented in volumes II and III. The cost estimates a...

Micropyrolyzer for chemical analysis of liquid and solid samples

DOEpatents

Mowry, Curtis D.; Morgan, Catherine H.; Manginell, Ronald P.; Frye-Mason, Gregory C.

2006-07-18

A micropyrolyzer has applications to pyrolysis, heated chemistry, and thermal desorption from liquid or solid samples. The micropyrolyzer can be fabricated from semiconductor materials and metals using standard integrated circuit technologies. The micropyrolyzer enables very small volume samples of less than 3 microliters and high sample heating rates of greater than 20.degree. C. per millisecond. A portable analyzer for the field analysis of liquid and solid samples can be realized when the micropyrolyzer is combined with a chemical preconcentrator, chemical separator, and chemical detector. Such a portable analyzer can be used in a variety of government and industrial applications, such as non-proliferation monitoring, chemical and biological warfare detection, industrial process control, water and air quality monitoring, and industrial hygiene.

Roles of air stored in burrows of the mudskipper Boleophthalmus pectinirostris for adult respiration and embryonic development.

PubMed

Toba, A; Ishimatsu, A

2014-03-01

Air was stored in 90% of Boleophthalmus pectinirostris burrows in summer breeding months when fish were active on the mudflat surface during low tide but only in 50% of burrows in overwintering months when the fish confined themselves to burrows. The volume of gas recovered from the burrows ranged from 30 to > 400 ml. The partial pressure of oxygen (PO₂) of the gas varied from 5 to 20 kPa and was inversely related to the partial pressure of carbon dioxide (PCO₂) in all but the wintering periods. Sampling in July demonstrated that gas was stored in both male and female burrows with no difference in volume, PO₂ or PCO₂ between them. Adult fish were able to survive total submersion in hypoxic (PO₂ = 1.96 kPa) water for 8 h, but no embryos survived to hatch in the hypoxic aquatic environment. Thus, the deposited air appears to be a crucial source of oxygen for the embryos developing in the egg chamber of the burrow, but may play only a subsidiary role for adult respiration during presumed high-tide confinement. © 2014 The Fisheries Society of the British Isles.

High-pressure swing system for measurements of radioactive fission gases in air samples

NASA Astrophysics Data System (ADS)

Schell, W. R.; Vives-Battle, J.; Yoon, S. R.; Tobin, M. J.

1999-01-01

Radionuclides emitted from nuclear reactors, fuel reprocessing facilities and nuclear weapons tests are distributed widely in the atmosphere but have very low concentrations. As part of the Comprehensive Test Ban Treaty (CTBT), identification and verification of the emission of radionuclides from such sources are fundamental in maintaining nuclear security. To detect underground and underwater nuclear weapons tests, only the gaseous components need to be analyzed. Equipment has now been developed that can be used to collect large volumes of air, separate and concentrate the radioactive gas constituents, such as xenon and krypton, and measure them quantitatively. By measuring xenon isotopes with different half-lives, the time since the fission event can be determined. Developments in high-pressure (3500 kPa) swing chromatography using molecular sieve adsorbents have provided the means to collect and purify trace quantities of the gases from large volumes of air automatically. New scintillation detectors, together with timing and pulse shaping electronics, have provided the low-background levels essential in identifying the gamma ray, X-ray, and electron energy spectra of specific radionuclides. System miniaturization and portability with remote control could be designed for a field-deployable production model.

High air volume to low liquid volume aerosol collector

DOEpatents

Masquelier, Donald A.; Milanovich, Fred P.; Willeke, Klaus

2003-01-01

A high air volume to low liquid volume aerosol collector. A high volume flow of aerosol particles is drawn into an annular, centripetal slot in a collector which directs the aerosol flow into a small volume of liquid pool contained is a lower center section of the collector. The annular jet of air impinges into the liquid, imbedding initially airborne particles in the liquid. The liquid in the pool continuously circulates in the lower section of the collector by moving to the center line, then upwardly, and through assistance by a rotating deflector plate passes back into the liquid at the outer area adjacent the impinging air jet which passes upwardly through the liquid pool and through a hollow center of the collector, and is discharged via a side outlet opening. Any liquid droplets escaping with the effluent air are captured by a rotating mist eliminator and moved back toward the liquid pool. The collector includes a sensor assembly for determining, controlling, and maintaining the level of the liquid pool, and includes a lower centrally located valve assembly connected to a liquid reservoir and to an analyzer for analyzing the particles which are impinged into the liquid pool.

Elemental composition and size distribution of particulates in Cleveland, Ohio

NASA Technical Reports Server (NTRS)

King, R. B.; Fordyce, J. S.; Neustadter, H. E.; Leibecki, H. F.

1975-01-01

Measurements were made of the elemental particle size distribution at five contrasting urban environments with different source-type distributions in Cleveland, Ohio. Air quality conditions ranged from normal to air pollution alert levels. A parallel network of high-volume cascade impactors (5-state) were used for simultaneous sampling on glass fiber surfaces for mass determinations and on Whatman-41 surfaces for elemental analysis by neutron activation for 25 elements. The elemental data are assessed in terms of distribution functions and interrelationships and are compared between locations as a function of resultant wind direction in an attempt to relate the findings to sources.

Elemental composition and size distribution of particulates in Cleveland, Ohio

NASA Technical Reports Server (NTRS)

Leibecki, H. F.; King, R. B.; Fordyce, J. S.; Neustadter, H. E.

1975-01-01

Measurements have been made of the elemental particle size distribution at five contrasting urban environments with different source-type distributions in Cleveland, Ohio. Air quality conditions ranged from normal to air pollution alert levels. A parallel network of high-volume cascade impactors (5-stage) were used for simultaneous sampling on glass fiber surfaces for mass determinations and on Whatman-41 surfaces for elemental analysis by neutron activation for 25 elements. The elemental data are assessed in terms of distribution functions and interrelationships and are compared between locations as a function of resultant wind direction in an attempt to relate the findings to sources.

Measurement of polyurethane foam - air partition coefficients for semivolatile organic compounds as a function of temperature: Application to passive air sampler monitoring.

PubMed

Francisco, Ana Paula; Harner, Tom; Eng, Anita

2017-05-01

Polyurethane foam - air partition coefficients (K PUF-air ) for 9 polycyclic aromatic hydrocarbons (PAHs), 10 alkyl-substituted PAHs, 4 organochlorine pesticides (OCPs) and dibenzothiophene were measured as a function of temperature over the range 5 °C-35 °C, using a generator column approach. Enthalpies of PUF-to-air transfer (ΔH PUF-air , kJ/mol) were determined from the slopes of log K PUF-air versus 1000/T (K), and have an average value of 81.2 ± 7.03 kJ/mol. The log K PUF-air values at 22 °C ranged from 4.99 to 7.25. A relationship for log K PUF-air versus log K OA was shown to agree with a previous relationship based on only polychlorinated biphenyls (PCBs) and derived from long-term indoor uptake study experiments. The results also confirm that the existing K OA -based model for predicting log K PUF-air values is accurate. This new information is important in the derivation of uptake profiles and effective air sampling volumes for PUF disk samplers so that results can be reported in units of concentration in air. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Air Occupation: Asking the Right Questions

DTIC Science & Technology

1997-03-01

Darrel D. Whitcomb, “Air Power and the Ho Chi Minh Trail,” Airpower and Campaign Planning, Air Command and Staff College Coursebook , Volume 8, March 1997...measure of benevolence.14 Some form of physical repression may be necessary, but focusing on the cultural aspects to exploit the population’s existing...Campaign Planning, Air Command and Staff College Coursebook , Volume 8, March 1997. Widnall, Honorable Sheila E., Secretary of the Air Force, Fiscal Years

Survival suit volume reduction associated with immersion: implications for buoyancy estimation in offshore workers of different size.

PubMed

Stewart, Arthur; Ledingham, Robert; Furnace, Graham; Williams, Hector; Coleshaw, Susan

2017-06-01

It is currently unknown how body size affects buoyancy in submerged helicopter escape. Eight healthy males aged 39.6 ± 12.6 year (mean ± SD) with BMI 22.0-40.0 kg m -2 wearing a standard survival ('dry') suit undertook a normal venting manoeuvre and underwent 3D scanning to assess body volume (wearing the suit) before and after immersion in a swimming pool. Immersion-induced volume loss averaged 14.4 ± 5.4 l, decreased with increasing dry density (mass volume -1 ) and theoretical buoyant force in 588 UK offshore workers was found to be 264 ± 46 and 232 ± 60 N using linear and power functions, respectively. Both approaches revealed heavier workers to have greater buoyant force. While a larger sample may yield a more accurate buoyancy prediction, this study shows heavier workers are likely to have greater buoyancy. Without free-swimming capability to overcome such buoyancy, some individuals may possibly exceed the safe limit to enable escape from a submerged helicopter. Practitioner Summary: Air expulsion reduced total body volume of survival-suited volunteers following immersion by an amount inversely proportional to body size. When applied to 588 offshore workers, the predicted air loss suggested buoyant force to be greatest in the heaviest individuals, which may impede their ability to exit a submerged helicopter.

Self- and Air-Broadened Line Shape Parameters of (12)CH(4) : 4500-4620 cm(-1)

NASA Astrophysics Data System (ADS)

Devi, V. Malathy; Benner, D. Chris; Sung, K.; Brown, L. R.; Crawford, T. J.; Smith, M. A. H.; Mantz, A. W.; Predoi-Cross, A.

2014-06-01

Accurate knowledge of spectral line shape parameters is important for infrared transmission and radiance calculations in the terrestrial atmosphere. We report the self and air-broadened Lorentz widths, shifts and line mixing coefficients along with their temperature dependencies for methane absorption lines in the 2.2 µm spectral region. For this, we obtained a series of high-resolution, high S/N spectra of 99.99% 12C-enriched samples of pure methane and its dilute mixtures in dry air at cold temperatures down to 150 K using the Bruker IFS 125HR Fourier transform spectrometer at JPL. The coolable absorption cell had an optical path of 20.38 cm and was specially built to reside inside the sample compartment of the Bruker FTS1. The 13 spectra used in the analysis consisted of seven pure 12CH4 spectra at pressures from 4.5 to 169 Torr and six air-broadened spectra with total sample pressures of 113-300 Torr and methane volume mixing ratios between 4 and 9.7%. These 13 spectra were fit simultaneously using the multispectrum least-squares fitting technique2. The results will be compared to existing values reported in the literature3. as part of the GNU EPrints system , and is freely redistributable under the GPL .

Air Pollution Translations: A Bibliography with Abstracts - Volume 4.

ERIC Educational Resources Information Center

Environmental Protection Agency, Research Triangle Park, NC. Air Pollution Technical Information Center.

This volume is the fourth in a series of compilations presenting abstracts and indexes of translations of technical air pollution literature. The entries are grouped into 12 subject categories: Emission Sources, Control Methods, Measurement Methods, Air Quality Measurements, Atmospheric Interaction, Basic Science and Technology, Effects--Human…

Atmospheric organochlorine pollutants and air-sea exchange of hexachlorocyclohexane in the Bering and Chukchi Seas

USGS Publications Warehouse

Hinckley, D.A.; Bidleman, T.F.; Rice, C.P.

1991-01-01

Organochlorine pesticides have been found in Arctic fish, marine mammals, birds, and plankton for some time. The lack of local sources and remoteness of the region imply long-range transport and deposition of contaminants into the Arctic from sources to the south. While on the third Soviet-American Joint Ecological Expedition to the Bering and Chukchi Seas (August 1988), high-volume air samples were taken and analyzed for organochlorine pesticides. Hexachlorocyclohexane (HCH), hexachlorobenzene, polychlorinated camphenes, and chlordane (listed in order of abundance, highest to lowest) were quantified. The air-sea gas exchange of HCH was estimated at 18 stations during the cruise. Average alpha-HCH concentrations in concurrent atmosphere and surface water samples were 250 pg m-3 and 2.4 ng L-1, respectively, and average gamma-HCH concentrations were 68 pg m-3 in the atmosphere and 0.6 ng L-1 in surface water. Calculations based on experimentally derived Henry's law constants showed that the surface water was undersaturated with respect to the atmosphere at most stations (alpha-HCH, average 79% saturation; gamma-HCH, average 28% saturation). The flux for alpha-HCH ranged from -47 ng m-2 day-1 (sea to air) to 122 ng m-2 d-1 (air to sea) and averaged 25 ng m-2 d-1 air to sea. All fluxes of gamma-HCH were from air to sea, ranged from 17 to 54 ng m-2 d-1, and averaged 31 ng m-2 d-1.

Sampling and physical characterization of diesel exhaust aerosols. SAE Paper 770720

DOE Office of Scientific and Technical Information (OSTI.GOV)

Verrant, J.A.; Kittelson, D.A.

Diesel exhaust aerosols are highly dynamic and therefore, difficult to sample without introducing falsification. This paper describes a study of these aerosols using a rapid dilution sampling system and an electrical aerosol analyzer. An Onan single cylinder indirect injection engine was used as an exhaust source. The sampler diluted the exhaust with clean air in ratios of 400:1 to 600:1 in order to prevent sample falsification by condensation and coagulation. The electrical aerosol analyzer was used to determine particle size and concentration. Volume concentration in the exhaust ranged from 2000 to 50,000 ..mu.. m/sup 3/ cm/sup -3/ which correspond tomore » mass loadings of 2.0 to 50 mg m/sup -3/ (assuming a density of 1 gm cm/sup -3/). Volume geometric mean diameters ranged from 0.12 to 0.19 ..mu..m. Evaporation and coagulation effects on diesel aerosols were observed by aging in a Teflon holding bag. A simple evaporation model was fit to the decrease of aerosol volume concentration with time. The fit revealed that the aerosols evaporated as if they were composed of normal paraffins in the 350 to 500 molecular weight range. Although the sample dilution system used in this study may alter the sample somewhat, it is probably analogous to what happens at the tailpipe of a vehicle. Measurements taken on a test track in the exhaust plume of a Peugeot 504 diesel showed aerosol size distributions very similar to those measured in our laboratory studies.« less

THE NEW YORK CITY URBAN DISPERSION PROGRAM MARCH 2005 FIELD STUDY: TRACER METHODS AND RESULTS.

DOE Office of Scientific and Technical Information (OSTI.GOV)

WATSON, T.B.; HEISER, J.; KALB, P.

The Urban Dispersion Program March 2005 Field Study tracer releases, sampling, and analytical methods are described in detail. There were two days where tracer releases and sampling were conducted. A total of 16.0 g of six tracers were released during the first test day or Intensive Observation Period (IOP) 1 and 15.7 g during IOP 2. Three types of sampling instruments were used in this study. Sequential air samplers, or SAS, collected six-minute samples, while Brookhaven atmospheric tracer samplers (BATS) and personal air samplers (PAS) collected thirty-minute samples. There were a total of 1300 samples resulting from the two IOPs.more » Confidence limits in the sampling and analysis method were 20% as determined from 100 duplicate samples. The sample recovery rate was 84%. The integrally averaged 6-minute samples were compared to the 30-minute samples. The agreement was found to be good in most cases. The validity of using a background tracer to calculate sample volumes was examined and also found to have a confidence level of 20%. Methods for improving sampling and analysis are discussed. The data described in this report are available as Excel files. An additional Excel file of quality assured tracer data for use in model validation efforts is also available. The file consists of extensively quality assured BATS tracer data with background concentrations subtracted.« less

Day and night variation in chemical composition and toxicological responses of size segregated urban air PM samples in a high air pollution situation

NASA Astrophysics Data System (ADS)

Jalava, P. I.; Wang, Q.; Kuuspalo, K.; Ruusunen, J.; Hao, L.; Fang, D.; Väisänen, O.; Ruuskanen, A.; Sippula, O.; Happo, M. S.; Uski, O.; Kasurinen, S.; Torvela, T.; Koponen, H.; Lehtinen, K. E. J.; Komppula, M.; Gu, C.; Jokiniemi, J.; Hirvonen, M.-R.

2015-11-01

Urban air particulate pollution is a known cause for adverse human health effects worldwide. China has encountered air quality problems in recent years due to rapid industrialization. Toxicological effects induced by particulate air pollution vary with particle sizes and season. However, it is not known how distinctively different photochemical activity and different emission sources during the day and the night affect the chemical composition of the PM size ranges and subsequently how it is reflected to the toxicological properties of the PM exposures. The particulate matter (PM) samples were collected in four different size ranges (PM10-2.5; PM2.5-1; PM1-0.2 and PM0.2) with a high volume cascade impactor. The PM samples were extracted with methanol, dried and thereafter used in the chemical and toxicological analyses. RAW264.7 macrophages were exposed to the particulate samples in four different doses for 24 h. Cytotoxicity, inflammatory parameters, cell cycle and genotoxicity were measured after exposure of the cells to particulate samples. Particles were characterized for their chemical composition, including ions, element and PAH compounds, and transmission electron microscopy (TEM) was used to take images of the PM samples. Chemical composition and the induced toxicological responses of the size segregated PM samples showed considerable size dependent differences as well as day to night variation. The PM10-2.5 and the PM0.2 samples had the highest inflammatory potency among the size ranges. Instead, almost all the PM samples were equally cytotoxic and only minor differences were seen in genotoxicity and cell cycle effects. Overall, the PM0.2 samples had the highest toxic potential among the different size ranges in many parameters. PAH compounds in the samples and were generally more abundant during the night than the day, indicating possible photo-oxidation of the PAH compounds due to solar radiation. This was reflected to different toxicity in the PM samples. Some of the day to night difference may have been caused also by differing wind directions transporting air masses from different emission sources during the day and the night. The present findings indicate the important role of the local particle sources and atmospheric processes on the health related toxicological properties of the PM. The varying toxicological responses evoked by the PM samples showed the importance of examining various particle sizes. Especially the detected considerable toxicological activity by PM0.2 size range suggests they're attributable to combustion sources, new particle formation and atmospheric processes.

Control of particle size by coagulation of novel condensation aerosols in reservoir chambers.

PubMed

Hong, John N; Hindle, Michael; Byron, Peter R

2002-01-01

The coagulation growth behavior of capillary aerosol generator (CAG) condensation aerosols was investigated in a series of reservoir chambers. Aerosols consisted of a condensed system of 0.7% w/w benzil (model drug) in propylene glycol (vehicle). These were generated into 250-, 500-, 1,000-, and 2,000-mL reservoirs in both flowing air-stream and static air experiments. Changes in drug and total aerosol particle size were measured by a MOUDI cascade impactor. In both series of experiments the CAG aerosols grew in size. Growth in flowing air-stream experiments was attributed to the amount of accumulation aerosols experienced in reservoirs during sampling and increased with increasing reservoir volume. Mean (SD) MMAD's for the total mass distribution measured for the 250- and 2,000-mL reservoirs were 0.70 (0.02) and 0.87 (0.03) microm, respectively. For the benzil mass distribution, they were 0.64 (0.02) and 0.87 (0.06) microm, respectively. Growth in static air experiments was dependent on the volume aerosol boluses were restricted to and increased with decreasing reservoir volume. Mean (SD) initial MMAD's for the benzil mass distribution for the 250- and 2,000-mL reservoirs were 1.44 (0.03) and 1.24 (0.08) microm, respectively. Holding aerosols for up to 60 sec further increased their size. Mean (SD) MMAD's for benzil after holding for 60 sec in these reservoirs were 2.28 (0.04) and 1.67 (0.09) microm, respectively. The coagulation behavior and therefore particle size of CAG aerosols may be modified and controlled by reservoir chambers for drug targeting within the respiratory tract.

Molecular marker study of extractable organic matter in aerosols from urban areas of China

NASA Astrophysics Data System (ADS)

Simoneit, Bernd R. T.; Sheng, Guoying; Chen, Xiaojing; Fu, Jiamo; Zhang, Jian; Xu, Yuping

The solvent-extractable compounds (lipids) of aerosol samples, which were collected from a western suburb of Beijing, in the city of Guiyang and on the outskirts of Guangzhou, P.R. China, using a standard high volume air sampler, were investigated to determine the distributions of homologous compounds and biomarkers. These preliminary results show that all samples contain aliphatic hydrocarbons including n-alkanes, steranes and triterpanes, derived from both biogenic sources (vascular plant wax input) and fossil fuel contamination (coal, crude oil, etc.). Polynuclear aromatic hydrocarbons, which are considered to be combustion products from fossil fuels such as petroleum and, especially in this case, coal burning, are also widely distributed in all samples. Oxygenated compounds (e.g. alkanoic acids, alkanones and alkanols) are present as major fractions and are derived from mainly natural sources. Furthermore, some compositional differences are observed for the organic compounds in samples from different heights above ground. This is interpreted to be due to dilution at higher levels of locally generated aerosol with upper air aerosol transported over longer distances.

Development of a new aerosol monitoring system and its application in Fukushima nuclear accident related aerosol radioactivity measurement at the CTBT radionuclide station in Sidney of Canada.

PubMed

Zhang, Weihua; Bean, Marc; Benotto, Mike; Cheung, Jeff; Ungar, Kurt; Ahier, Brian

2011-12-01

A high volume aerosol sampler ("Grey Owl") has been designed and developed at the Radiation Protection Bureau, Health Canada. Its design guidance is based on the need for a low operational cost and reliable sampler to provide daily aerosol monitoring samples that can be used as reference samples for radiological studies. It has been developed to provide a constant air flow rate at low pressure drops (∼3 kPa for a day sampling) with variations of less than ±1% of the full scale flow rate. Its energy consumption is only about 1.5 kW for a filter sampling over 22,000 standard cubic meter of air. It has been demonstrated in this Fukushima nuclear accident related aerosol radioactivity monitoring study at Sidney station, B.C. that the sampler is robust and reliable. The results provided by the new monitoring system have been used to support decision-making in Canada during an emergency response. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spectrometric Analysis for Pulse Jet Mixer Testing

DOE Office of Scientific and Technical Information (OSTI.GOV)

ZEIGLER, KRISTINE

2004-07-12

The Analytical Development Section (ADS) was tasked with providing support for a Hanford River Protection Program-Waste Treatment Program (RPP-WTP) project test involving absorption analysis for non-Newtonian pulse jet mixer testing for small scale (PJM) and prototype (CRV) tanks with sparging. Tanks filled with clay were mixed with various amounts of powdered dye as a tracer. The objective of the entire project was to determine the best mixing protocol (nozzle velocity, number of spargers used, total air flow, etc.) by determining the percent mixed volume through the use of an ultraviolet-visible (UV-Vis) spectrometer. The dye concentration within the sample could bemore » correlated to the volume fraction mixed in the tank. Samples were received in vials, a series of dilutions were generated from the clay, allowed to equilibrate, then centrifuged and siphoned for the supernate liquid to analyze by absorption spectroscopy. Equilibration of the samples and thorough mixing of the samples were a continuous issue with dilution curves being difficult to obtain. Despite these technical issues, useful data was obtained for evaluation of various mix conditions.« less

Surface Environmental Surveillance Project: Locations Manual Volume 1 – Air and Water Volume 2 – Farm Products, Soil & Vegetation, and Wildlife

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fritz, Brad G.; Patton, Gregory W.; Stegen, Amanda

2009-01-01

This report describes all environmental monitoring locations associated with the Surface Environmental Surveillance Project. Environmental surveillance of the Hanford site and surrounding areas is conducted by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE). Sampling is conducted to evaluate levels of radioactive and nonradioactive pollutants in the Hanford environs, as required in DOE Order 450.1, Environmental Protection Program, and DOE Order 5400.5, Radiation Protection of the Public and the Environment. The environmental surveillance sampling design is described in the Hanford Site Environmental Monitoring Plan, United States Department of Energy, Richland Operation Office (DOE/RL-91-50). This documentmore » contains the locations of sites used to collect samples for the Surface Environmental Surveillance Project (SESP). Each section includes directions, maps, and pictures of the locations. A general knowledge of roads and highways on and around the Hanford Site is necessary to successfully use this manual. Supplemental information (Maps, Gazetteer, etc.) may be necessary if user is unfamiliar with local routes. The SESP is a multimedia environmental surveillance effort to measure the concentrations of radionuclides and chemicals in environmental media to demonstrate compliance with applicable environmental quality standards and public exposure limits, and assessing environmental impacts. Project personnel annually collect selected samples of ambient air, surface water, agricultural products, fish, wildlife, and sediments. Soil and vegetation samples are collected approximately every 5 years. Analytical capabilities include the measurement of radionuclides at very low environmental concentrations and, in selected media, nonradiological chemicals including metals, anions, volatile organic compounds, and total organic carbon.« less

Air Quality Criteria for Ozone and Related Photochemical Oxidants (Second External Review Draft)

EPA Science Inventory

This second external review draft of the Air Quality Criteria for Ozone and Related Photochemical Oxidants, Volumes I-III (Ozone Criteria Document) is being released for public comment and for review by EPA's Clean Air Scientific Advisory Committee (CASAC) r...

Automation Applications in an Advance Air Traffic Management System : Volume IIB : Functional Analysis of Air Traffic Management (Cont'd)

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

40 CFR 52.70 - Identification of plan.

Code of Federal Regulations, 2011 CFR

2011-07-01

... nonattainment areas submitted by the Governor of Alaska on January 18, 1980 as follows: Volume II. Analysis of...: Volume II. Analysis of Problems, Control Actions Section V. Ambient Air Monitoring A. Purpose C. Air Monitoring Network E. Annual Review (9) Provisions of a State Air Quality Control Plan submitted by the...

40 CFR 52.70 - Identification of plan.

Code of Federal Regulations, 2012 CFR

2012-07-01

... nonattainment areas submitted by the Governor of Alaska on January 18, 1980 as follows: Volume II. Analysis of...: Volume II. Analysis of Problems, Control Actions Section V. Ambient Air Monitoring A. Purpose C. Air Monitoring Network E. Annual Review (9) Provisions of a State Air Quality Control Plan submitted by the...

Automated Applications in an Advanced Air Traffic Management System : Volume 2B. Functional Analysis of Air Traffic Management (Cont'd.)

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

Automation Applications in an Advanced Air Traffic Management System : Volume 2A. Functional Analysis of Air Traffic Management.

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

Automation Applications in an Advanced Air Traffic Management System : Volume 2C. Functional Analysis of Air Traffic Management (Cont.'d)

DOT National Transportation Integrated Search

1974-08-01

Volume 2 contains the analysis and description of air traffic management activities at three levels of detail - functions, subfunctions, and tasks. A total of 265 tasks are identified and described, and the flow of information inputs and outputs amon...

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.

Surface crystallization of supercooled water in clouds

PubMed Central

Tabazadeh, A.; Djikaev, Y. S.; Reiss, H.

2002-01-01

The process by which liquid cloud droplets homogeneously crystallize into ice is still not well understood. The ice nucleation process based on the standard and classical theory of homogeneous freezing initiates within the interior volume of a cloud droplet. Current experimental data on homogeneous freezing rates of ice in droplets of supercooled water, both in air and emulsion oil samples, show considerable scatter. For example, at −33°C, the reported volume-based freezing rates of ice in supercooled water vary by as many as 5 orders of magnitude, which is well outside the range of measurement uncertainties. Here, we show that the process of ice nucleus formation at the air (or oil)-liquid water interface may help to explain why experimental results on ice nucleation rates yield different results in different ambient phases. Our results also suggest that surface crystallization of ice in cloud droplets can explain why low amounts of supercooled water have been observed in the atmosphere near −40°C. PMID:12456877

United States Air Force Summer Research Program -- 1992 High School Apprenticeship Program (HSAP) Reports. Volume 13. Phillips Laboratory

DTIC Science & Technology

1992-01-01

Research Program Phillips Laboratory I4oJ A*6Iv4 Sponsored by: Air Force Office of Scientific Research Kirtland Air ...UNITED STATES AIR FORCE SUMMER RESEARCH PROGki"A -- 1992 HIGH SCHOOL APPRENTICESHIP PROGRAM (HSAP) REPORTS VOLUME 13 (t PHILLIPS LABORATORY . RESEARCH ...Arlington High School Final Report for: Summer Research Program Geophysics Directorate Phillips Laboratory

Specific gravity variation in robusta eucalyptus grown in Hawaii

Treesearch

Roger G. Skolmen

1972-01-01

The specific gravity (air-dry volume, ovendry weight) of Eucalyptus robusta wood was tested within and between trees from 10 stands. Mean specific gravity was 0.603, but the range in individual samples for 50 trees was 0.331 to 0.869, and was 0.357 to 0.755 within one cross section. A consistent increase was recorded in all trees from pith to cambium and from butt to...

Remedial Investigation Addendum Report Data Item A009. Volume 1: Report Test

DTIC Science & Technology

1993-12-01

depending on chemical form and oxidation state. Environmentally, chromium exists primarily as trivalent and hexavalent compounds. Hexavalent forms are...intracellularly (Goyer, 1991). Hexavalent chromium compounds are found to predominate in air, surface waters, and groundwaters, while the trivalent forms dominate...in sediments and soils (USEPA, 1984b). Chromium in biological samples and foods exists almost exclusively in the trivalent state because of the rapid

Pharmaceutical dust exposure at pharmacies using automatic dispensing machines: a preliminary study.

PubMed

Fent, Kenneth W; Durgam, Srinivas; Mueller, Charles

2014-01-01

Automatic dispensing machines (ADMs) used in pharmacies concentrate and dispense large volumes of pharmaceuticals, including uncoated tablets that can shed dust. We evaluated 43 employees' exposures to pharmaceutical dust at three pharmacies where ADMs were used. We used an optical particle counter to identify tasks that generated pharmaceutical dust. We collected 72 inhalable dust air samples in or near the employees' breathing zones. In addition to gravimetric analysis, our contract laboratory used internal methods involving liquid chromatography to analyze these samples for active pharmaceutical ingredients (APIs) and/or lactose, an inactive filler in tablets. We had to choose samples for these additional analyses because many methods used different extraction solvents. We selected 57 samples for analysis of lactose. We used real-time particle monitoring results, observations, and information from employees on the dustiness of pharmaceuticals to select 28 samples (including 13 samples that were analyzed for lactose) for analysis of specific APIs. Pharmaceutical dust was generated during a variety of tasks like emptying and refilling of ADM canisters. Using compressed air to clean canisters and manual count machines produced the overall highest peak number concentrations (19,000-580,000 particles/L) of smallest particles (count median aerodynamic diameter ≤ 2 μm). Employees who refilled, cleaned, or repaired ADM canisters, or hand filled prescriptions were exposed to higher median air concentrations of lactose (5.0-12 μg/m(3)) than employees who did other jobs (0.04-1.3 μg/m(3)), such as administrative/office work, labeling/packaging, and verifying prescriptions. We detected 10 APIs in air, including lisinopril, a drug prescribed for high blood pressure, levothyroxine, a drug prescribed for hypothyroidism, and methotrexate, a hazardous drug prescribed for cancer and other disorders. Three air concentrations of lisinopril (1.8-2.7 μg/m(3)) exceeded the lower bound of the manufacturer's hazard control band (1-10 μg/m(3)). All other API air concentrations were below applicable occupational exposure limits. Our findings indicate that some pharmacy employees are exposed to multiple APIs and that measures are needed to control those exposures.

Reactive nitrogen budget during the NASA SONEX Mission

NASA Astrophysics Data System (ADS)

Talbot, R. W.; Dibb, J. E.; Scheuer, E. M.; Kondo, Y.; Koike, M.; Singh, H. B.; Salas, L. B.; Fukui, Y.; Ballenthin, J. O.; Meads, R. F.; Miller, T. M.; Hunton, D. E.; Viggiano, A. A.; Blake, D. R.; Blake, N. J.; Atlas, E.; Flocke, F.; Jacob, D. J.; Jaegle, L.

The SASS Ozone and Nitrogen Oxides Experiment (SONEX) over the North Atlantic during October/November 1997 offered an excellent opportunity to examine the budget of reactive nitrogen in the upper troposphere (8-12 km altitude). The median measured total reactive nitrogen (NOy) mixing ratio was 425 parts per trillion by volume (pptv). A data set merged to the HNO3 measurement time resolution was used to calculate NOy (NOy sum) by summing the reactive nitrogen species (a combination of measured plus modeled results) and comparing it to measured NOy (NOy meas.). Comparisons were done for tropospheric air (O3 <100 parts per billion by volume (ppbv)) and stratospherically influenced air (O3 > 100 ppbv) with both showing good agreement between NOy sum and NOy meas. (slope >0.9 and r² ≈ 0.9). The total reactive nitrogen budget in the upper troposphere over the North Atlantic appears to be dominated by a mixture of NOx (NO + NO2), HNO3, and PAN. In tropospheric air median values of NOx/NOy were ≈ 0.25, HNO3/NOy ≈ 0.35 and PAN/NOy ≈ 0.17. Particulate NO3- and alkyl nitrates together composed <10% of NOy, while model estimated HNO4 averaged 12%. For the air parcels sampled during SONEX, there does not appear to be a large reservoir of unidentified NOy compounds.

Cargo Logistics Airlift Systems Study (CLASS). Volume 1: Analysis of current air cargo system

NASA Technical Reports Server (NTRS)

Burby, R. J.; Kuhlman, W. H.

1978-01-01

The material presented in this volume is classified into the following sections; (1) analysis of current routes; (2) air eligibility criteria; (3) current direct support infrastructure; (4) comparative mode analysis; (5) political and economic factors; and (6) future potential market areas. An effort was made to keep the observations and findings relating to the current systems as objective as possible in order not to bias the analysis of future air cargo operations reported in Volume 3 of the CLASS final report.

Size distributions of ambient air particles and enrichment factor analyses of metallic elements at Taichung Harbor near the Taiwan Strait

NASA Astrophysics Data System (ADS)

Fang, Guor-Cheng; Wu, Yuh-Shen; Chang, Shih-Yu; Huang, Shih-Han; Rau, Jui-Yeh

2006-10-01

This work attempts to characterize metallic elements associated with atmospheric particulate matter on a dry deposition plate, a TE-PUF high-volume air sampler and a universal air sampler. Dry deposition fluxes of particulates and concentrations of total suspended particulate, fine (PM 2.5) and coarse (PM 2.5-10) particulate matters were collected at Taichung harbor sampling sites from August 2004 to January 2005. Chemical analyses of metallic elements were made using a flame atomic absorption spectrophotometer coupled with hollow cathode lamps. Concentrations of metal elements in the forms of coarse particles and fine particles as well as the coarse/fine particulate ratios were presented. Statistical methods such as correlation analysis, principal component analysis and enrichment factor analysis were performed to compare the chemical components and identify possible emission sources at the sampling sites. Metallic elements of Cu, Zn, Pb, Cr, Ni and Mg had higher EF crust ratios in winter and spring than in summer and autumn. Diurnal and nocturnal variations of metallic element concentrations in fine and coarse particles were also discussed.

Microbial volatile organic compounds in moldy interiors: a long-term climate chamber study.

PubMed

Schuchardt, Sven; Strube, Andrea

2013-06-01

The present study simulated large-scale indoor mold damage in order to test the efficiency of air sampling for the detection of microbial volatile organic compounds (MVOCs). To do this, a wallpaper damaged by condensation was stored in a climate chamber (representing a hypothetical test room of 40 m(3) volume) and was inoculated with 14 typical indoor fungal strains. The chamber ventilation conditions were adjusted to common values found in moldy homes, and the mold growth was allowed to continue to higher than average values. The MVOC content of the chamber air was analyzed daily for a period of 105 days using coupled gas chromatography/mass spectrometry (GC-MS). This procedure guarantees MVOC profiling without external factors such as outdoor air, building materials, furniture, and occupants. However, only nine MVOCs could be detected during the sampling period, which indicates that the very low concentrated MVOCs are hardly accessible, even under these favorable conditions. Furthermore, most of the MVOCs that were detected cannot be considered as reliable indicators of mold growth in indoor environments. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Spectrophotometric probe

DOEpatents

Prather, W.S.; O'Rourke, P.E.

1994-08-02

A support structure is described bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe. 3 figs.

Spectrophotometric probe

DOEpatents

Prather, William S.; O'Rourke, Patrick E.

1994-01-01

A support structure bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe.

Nonflammable Hydraulic Power System for Tactical Aircraft. Volume 2. Equipment and Systems Test and Evaluation.

DTIC Science & Technology

1991-04-01

hold large quantities of air in solution at high pressures and at 8000 psi CTFE holds 500 times its volume of standard atmospheric air. Since air...cart bleeding can be expected to reduce dissolved air to about 1.5 times the amount held at atmospheric pressure. This is more than adequate for...aircraft hydraulic systems while circulating fluid through the cart reservoir which is vented to atmosphere . After open loop air bleeding, the aircraft

40 CFR 52.74 - Original identification of plan section.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Governor of Alaska on January 18, 1980 as follows: Volume II. Analysis of Problems, Control Actions Section... requirements of Air Quality Monitoring, 40 CFR part 58, subpart C, § 58.20, as follows: Volume II. Analysis of Problems, Control Actions Section V. Ambient Air Monitoring A. Purpose C. Air Monitoring Network E. Annual...

40 CFR 52.70 - Identification of plan.

Code of Federal Regulations, 2013 CFR

2013-07-01

... submitted by the Governor of Alaska on January 18, 1980 as follows: Volume II. Analysis of Problems, Control... requirements of Air Quality Monitoring, 40 CFR part 58, subpart C, § 58.20, as follows: Volume II. Analysis of Problems, Control Actions Section V. Ambient Air Monitoring A. Purpose C. Air Monitoring Network E. Annual...

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 6. Development and Transition Plans.

DOT National Transportation Integrated Search

1974-02-01

The volume presents the plans for implementing the Satellite-Based Advanced Air Traffic Management System (SAATMS) described in Volumes II, III, and IV. Two plans are presented: an RDT&E plan and a transition plan. The RDT&E plan is presented as a se...

USAF (United States Air Force) bioenvironmental noise data handbook. Volume 2: Index

NASA Astrophysics Data System (ADS)

Cole, J. N.; Peachey, N. J.

1983-03-01

This report is an index which identifies the individual volumes published during the 1975-1982 period by the Air Force Aerospace Medical Research Laboratory (AFAMRL) as a multi-volume report, ""USAF Bioenvironmental Noise Data Handbook'', AMRL-TR-75-50 and lists those aircraft, ground equipment and other systems reported there in.

Modifications of highway air pollution models for complex geometries, volume II : wind tunnel test program.

DOT National Transportation Integrated Search

2002-09-01

This is volume I1 of a two-volume report of a study to increase the scope and clarity of air pollution models for : depressed highway and street canyon sites. It presents the atmospheric wind tunnel program conducted to increase the : data base and i...

Stratospheric measurements of ozone-depleting substances and greenhouse gases using AirCores

NASA Astrophysics Data System (ADS)

Laube, Johannes; Leedham Elvidge, Emma; Kaiser, Jan; Sturges, Bill; Heikkinen, Pauli; Laurila, Tuomas; Hatakka, Juha; Kivi, Rigel; Chen, Huilin; Fraser, Paul; van der Veen, Carina; Röckmann, Thomas

2017-04-01

Retrieving air samples from the stratosphere has previously required aircraft or large balloons, both of which are expensive to operate. The novel "AirCore" technique (Karion et al., 2010) enables stratospheric sampling using weather balloons, which is much more cost effective. AirCores are long (up to 200 m) stainless steel tubes which are placed as a payload on a small balloon, can ascend to over 30 km and fill upon descent, collecting a vertical profile of the atmosphere. Retrieved volumes are much smaller though, which presents a challenge for trace gas analysis. To date, only the more abundant trace gases such as carnon dioxide (CO2) and methane (CH4) have been quantified in AirCores. Halogenated trace gases are also important greenhouse gases and many also deplete stratospheric ozone. Their concentrations are however much lower i.e. typically in the part per trillion (ppt) molar range. We here present the first stratospheric measurements of halocarbons in AirCores obtained using UEA's highly sensitive (detection limits of 0.01-0.1 ppt in 10 ml of air) gas chromatography mass spectrometry system. The analysed air originates from a Stratospheric Air Sub-sampler (Mrozek et al., 2016) which collects AirCore segments after the non-destructive CO2 and CH4 analysis. Successfully measured species include CFC-11, CFC-12, CFC-113, CFC-115, H-1211, H-1301, HCFC-22, HCFC-141b, HCFC-142b, HCFC-133a, and sulphur hexafluoride (SF6). We compare the observed mixing ratios and precisions with data obtained from samples collected during various high-altitude aircraft campaigns between 2009 and 2016 as well as with southern hemisphere tropospheric long-term trends. As part of the ERC-funded EXC3ITE (EXploring stratospheric Composition, Chemistry and Circulation with Innovative Techniques) project more than 40 AirCore flights are planned in the next 3 years with an expanded range of up to 30 gases in order to explore seasonal and interannual variability in the stratosphere. References Karion et al., J. Atmos. Ocean. Technol., 27(11), 1839-1853, 2010 Mrozek et al., Atmos. Meas. Tech., 9, 5607-5620, 2016

The Impact of Multiple Freeze-Thaw Cycles on the Microstructure of Aggregates from a Soddy-Podzolic Soil: A Microtomographic Analysis

NASA Astrophysics Data System (ADS)

Skvortsova, E. B.; Shein, E. V.; Abrosimov, K. N.; Romanenko, K. A.; Yudina, A. V.; Klyueva, V. V.; Khaidapova, D. D.; Rogov, V. V.

2018-02-01

With the help of computed X-ray microtomography with a resolution of 2.75 μm, changes in the microstructure and pore space of aggregates of 3 mm in diameter from the virgin soddy-podzolic soil (Glossic Retisol (Loamic)) in the air-dry, capillary-moistened, and frozen states after five freeze-thaw cycles were studied in a laboratory experiment. The freezing of the samples was performed at their capillary moistening. It was shown that capillary moistening of initially air-dry samples from the humus (AY), eluvial (EL), and illuvial (BT1) horizons at room temperature resulted in the development of the platy, fine vesicular, and angular blocky microstructure, respectively. The total volume of tomographically visible pores >10 μm increased by 1.3, 2.2, and 3.4 times, respectively. After freeze-thaw cycles, frozen aggregates partly preserved the structural arrangement formed during the capillary moistening. At the same time, in the frozen aggregate from the AY horizon, the total tomographic porosity decreased to the initial level of the air-dry soil. In the frozen aggregate from the EL horizon, large vesicular pores were formed, owing to which the total pore volume retained its increased values. The resistance of aggregate shape to the action of freeze-thaw cycles differed. The aggregate from the EL horizon completely lost its original configuration by the end of the experiment. The aggregate from the AY horizon displayed definite features of sagging after five freeze-thaw cycles, whereas the aggregate from the BT1 horizon preserved its original configuration.

Near-roadway monitoring of vehicle emissions as a function of mode of operation for light-duty vehicles.

PubMed

Wen, Dongqi; Zhai, Wenjuan; Xiang, Sheng; Hu, Zhice; Wei, Tongchuan; Noll, Kenneth E

2017-11-01

Determination of the effect of vehicle emissions on air quality near roadways is important because vehicles are a major source of air pollution. A near-roadway monitoring program was undertaken in Chicago between August 4 and October 30, 2014, to measure ultrafine particles, carbon dioxide, carbon monoxide, traffic volume and speed, and wind direction and speed. The objective of this study was to develop a method to relate short-term changes in traffic mode of operation to air quality near roadways using data averaged over 5-min intervals to provide a better understanding of the processes controlling air pollution concentrations near roadways. Three different types of data analysis are provided to demonstrate the type of results that can be obtained from a near-roadway sampling program based on 5-min measurements: (1) development of vehicle emission factors (EFs) for ultrafine particles as a function of vehicle mode of operation, (2) comparison of measured and modeled CO 2 concentrations, and (3) application of dispersion models to determine concentrations near roadways. EFs for ultrafine particles are developed that are a function of traffic volume and mode of operation (free flow and congestion) for light-duty vehicles (LDVs) under real-world conditions. Two air quality models-CALINE4 (California Line Source Dispersion Model, version 4) and AERMOD (American Meteorological Society/U.S. Environmental Protection Agency Regulatory Model)-are used to predict the ultrafine particulate concentrations near roadways for comparison with measured concentrations. When using CALINE4 to predict air quality levels in the mixing cell, changes in surface roughness and stability class have no effect on the predicted concentrations. However, when using AERMOD to predict air quality in the mixing cell, changes in surface roughness have a significant impact on the predicted concentrations. The paper provides emission factors (EFs) that are a function of traffic volume and mode of operation (free flow and congestion) for LDVs under real-world conditions. The good agreement between monitoring and modeling results indicates that high-resolution, simultaneous measurements of air quality and meteorological and traffic conditions can be used to determine real-world, fleet-wide vehicle EFs as a function of vehicle mode of operation under actual driving conditions.

Singing with reduced air sac volume causes uniform decrease in airflow and sound amplitude in the zebra finch.

PubMed

Plummer, Emily Megan; Goller, Franz

2008-01-01

Song of the zebra finch (Taeniopygia guttata) is a complex temporal sequence generated by a drastic change to the regular oscillations of the normal respiratory pattern. It is not known how respiratory functions, such as supply of air volume and gas exchange, are controlled during song. To understand the integration between respiration and song, we manipulated respiration during song by injecting inert dental medium into the air sacs. Increased respiratory rate after injections indicates that the reduction of air affected quiet respiration and that birds compensated for the reduced air volume. During song, air sac pressure, tracheal airflow and sound amplitude decreased substantially with each injection. This decrease was consistently present during each expiratory pulse of the song motif irrespective of the air volume used. Few changes to the temporal pattern of song were noted, such as the increased duration of a minibreath in one bird and the decrease in duration of a long syllable in another bird. Despite the drastic reduction in air sac pressure, airflow and sound amplitude, no increase in abdominal muscle activity was seen. This suggests that during song, birds do not compensate for the reduced physiological or acoustic parameters. Neither somatosensory nor auditory feedback mechanisms appear to effect a correction in expiratory effort to compensate for reduced air sac pressure and sound amplitude.

Organochlorine pesticides and PCBs in air of southern Mexico (2002-2004)

NASA Astrophysics Data System (ADS)

Alegria, Henry A.; Wong, Fiona; Jantunen, Liisa M.; Bidleman, Terry F.; Figueroa, Miguel Salvador; Bouchot, Gerardo Gold; Moreno, Victor Ceja; Waliszewski, Stefan M.; Infanzon, Raul

Air samples were collected in southern Mexico in 2002-2004 to determine the extent of contamination with organochlorine (OC) pesticides and polychlorinated biphenyls (PCBs). The ΣDDTs ranged from 239 to 2360 pg m -3. Other prominent OC pesticides were endosulfans, toxaphene and lindane. Pesticides detected in lower concentrations include chlordanes, dieldrin, and heptachlor. Proportions of DDT compounds suggested fresh use of DDT in some locations and a mix of fresh and aged residues at others. Ratios of trans-chlordane/ cis-chlordane were consistent with fresh chlordane usage or emission of residues from former termiticide applications. The ΣPCBs was relatively low at all sites. Concentrations of OC pesticides measured with passive samplers agreed well with those measured using high-volume samplers. Air back trajectory analysis suggests a complex pattern of regional atmospheric transport.

Multicapillary Gas Chromatography-Temperature Modulated Metal Oxide Semiconductor Sensors Array Detector for Monitoring of Volatile Organic Compounds in Closed Atmosphere Using Gaussian Apodization Factor Analysis.

PubMed

Alinoori, Amir Hossein; Masoum, Saeed

2018-05-22

A unique metal oxide semiconductor sensor (MOS) array detector with eight sensors was designed and fabricated in a PTFE chamber as an interface for coupling with multicapillary gas chromatography. This design consists of eight transfer lines with equal length between the multicapillary columns (MCC) and sensors. The deactivated capillary columns were passed through each transfer line and homemade flow splitter to distribute the same gas flow on each sensor. Using the eight ports flow splitter design helps us to equal the length of carrier gas path and flow for each sensor, minimizing the dead volume of the sensor's chamber and increasing chromatographic resolution. In addition to coupling of MCC to MOS array detector and other considerations in hardware design, modulation of MOS temperature was used to increase sensitivity and selectivity, and data analysis was enhanced with adapted Gaussian apodization factor analysis (GAFA) as a multivariate curve resolution algorithm. Continues air sampling and injecting system (CASI) design provides a fast and easily applied method for continues injection of air sample with no additional sample preparation. The analysis cycle time required for each run is less than 300 s. The high sample load and sharp injection with the fast separation by MCC decrease the peak widths and improve detection limits. This homemade customized instrument is an alternative to other time-consuming and expensive technologies for continuous monitoring of outgassing in air samples.

Airborne protein concentration: a key metric for type 1 allergy risk assessment-in home measurement challenges and considerations.

PubMed

Tulum, Liz; Deag, Zoë; Brown, Matthew; Furniss, Annette; Meech, Lynn; Lalljie, Anja; Cochrane, Stella

2018-01-01

Exposure to airborne proteins can be associated with the development of immediate, IgE-mediated respiratory allergies, with genetic, epigenetic and environmental factors also playing a role in determining the likelihood that sensitisation will be induced. The main objective of this study was to determine whether airborne concentrations of selected common aeroallergens could be quantified in the air of homes using easily deployable, commercially available equipment and analytical methods, at low levels relevant to risk assessment of the potential to develop respiratory allergies. Additionally, air and dust sampling were compared and the influence of factors such as different filter types on allergen quantification explored. Low volume air sampling pumps and DUSTREAM ® dust samplers were used to sample 20 homes and allergen levels were quantified using a MARIA ® immunoassay. It proved possible to detect a range of common aeroallergens in the home with sufficient sensitivity to quantify airborne concentrations in ranges relevant to risk assessment (Limits of Detection of 0.005-0.03 ng/m 3 ). The methodology discriminates between homes related to pet ownership and there were clear advantages to sampling air over dust which are described in this paper. Furthermore, in an adsorption-extraction study, PTFE (polytetrafluoroethylene) filters gave higher and more consistent recovery values than glass fibre (grade A) filters for the range of aeroallergens studied. Very low airborne concentrations of allergenic proteins in home settings can be successfully quantified using commercially available pumps and immunoassays. Considering the greater relevance of air sampling to human exposure of the respiratory tract and its other advantages, wider use of standardised, sensitive techniques to measure low airborne protein concentrations and how they influence development of allergic sensitisation and symptoms could accelerate our understanding of human dose-response relationships and refine our knowledge of thresholds of allergic sensitisation and elicitation via the respiratory tract.

Wave energy devices with compressible volumes.

PubMed

Kurniawan, Adi; Greaves, Deborah; Chaplin, John

2014-12-08

We present an analysis of wave energy devices with air-filled compressible submerged volumes, where variability of volume is achieved by means of a horizontal surface free to move up and down relative to the body. An analysis of bodies without power take-off (PTO) systems is first presented to demonstrate the positive effects a compressible volume could have on the body response. Subsequently, two compressible device variations are analysed. In the first variation, the compressible volume is connected to a fixed volume via an air turbine for PTO. In the second variation, a water column separates the compressible volume from another volume, which is fitted with an air turbine open to the atmosphere. Both floating and bottom-fixed, axisymmetric, configurations are considered, and linear analysis is employed throughout. Advantages and disadvantages of each device are examined in detail. Some configurations with displaced volumes less than 2000 m 3 and with constant turbine coefficients are shown to be capable of achieving 80% of the theoretical maximum absorbed power over a wave period range of about 4 s.

Wave energy devices with compressible volumes

PubMed Central

Kurniawan, Adi; Greaves, Deborah; Chaplin, John

2014-01-01

We present an analysis of wave energy devices with air-filled compressible submerged volumes, where variability of volume is achieved by means of a horizontal surface free to move up and down relative to the body. An analysis of bodies without power take-off (PTO) systems is first presented to demonstrate the positive effects a compressible volume could have on the body response. Subsequently, two compressible device variations are analysed. In the first variation, the compressible volume is connected to a fixed volume via an air turbine for PTO. In the second variation, a water column separates the compressible volume from another volume, which is fitted with an air turbine open to the atmosphere. Both floating and bottom-fixed, axisymmetric, configurations are considered, and linear analysis is employed throughout. Advantages and disadvantages of each device are examined in detail. Some configurations with displaced volumes less than 2000 m3 and with constant turbine coefficients are shown to be capable of achieving 80% of the theoretical maximum absorbed power over a wave period range of about 4 s. PMID:25484609

Biomimetic air sampling for detection of low concentrations of molecules and bioagents : LDRD 52744 final report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hughes, Robert Clark

2003-12-01

Present methods of air sampling for low concentrations of chemicals like explosives and bioagents involve noisy and power hungry collectors with mechanical parts for moving large volumes of air. However there are biological systems that are capable of detecting very low concentrations of molecules with no mechanical moving parts. An example is the silkworm moth antenna which is a highly branched structure where each of 100 branches contains about 200 sensory 'hairs' which have dimensions of 2 microns wide by 100 microns long. The hairs contain about 3000 pores which is where the gas phase molecules enter the aqueous (lymph)more » phase for detection. Simulations of diffusion of molecules indicate that this 'forest' of hairs is 'designed' to maximize the extraction of the vapor phase molecules. Since typical molecules lose about 4 decades in diffusion constant upon entering the liquid phase, it is important to allow air diffusion to bring the molecule as close to the 'sensor' as possible. The moth acts on concentrations as low as 1000 molecules per cubic cm. (one part in 1e16). A 3-D collection system of these dimensions could be fabricated by micromachining techniques available at Sandia. This LDRD addresses the issues involved with extracting molecules from air onto micromachined structures and then delivering those molecules to microsensors for detection.« less

Collaborative Multidisciplinary Sciences for Analysis and Design of Aerospace Vehicles. Volume 1

DTIC Science & Technology

2017-05-01

AEROSPACE VEHICLES Volume 1 5a. CONTRACT NUMBER FA8650-09-2-3938 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62201F 6. AUTHOR(S) Raymond M...S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBERDesign and Analysis Branch (AFRL/RQVC) Aerospace Vehicles Division Air Force Research...Laboratory, Aerospace Systems Directorate Wright-Patterson Air Force Base, OH 45433-7542 Air Force Materiel Command, United States Air Force Virginia

Air pollution assessment of Salé's city (Morocco)

NASA Astrophysics Data System (ADS)

Bounakhla, M.; Fatah, A.; Embarch, K.; Ibn Majah, M.; Azami, R.; Sabir, A.; Nejjar, A.; Cherkaoui, R.; Gaudry, A.

2003-05-01

Four sites were selected in Sale's city in Morocco in order to contribute in air pollution level assessment and determination of its effects on public health. The sites were selected so that they are close to the most important industrialized areas, they have a very high demographic density and they cover a heavy traffic. Two approaches of air sampling and subsequent analysis methods of elements in atmospheric aerosols have been performed. The first is a classical approach, which consists in sampling total airborne materials with a High Volume Sampler and analysing the samples using Atomic Absorption Spectroscopy (AAS). The second is having its interest for studies relating effects of particles on human health. It consists in employing a Dichotomous Sampler to collect inhalable particles and the X-ray Fluorescence (XRF) for elemental analysis. With such system, it was possible to collect separately respirable and inhalable aerosols. The ED-XRF analysis method used is appropriate for monitoring airborne polluants in living and working areas with advantage of simple preparation, nondestructive nature, rapidity and suitable limits of detection. Using this method, it was possible to identify and quantify S, Ca, CI, Fe, Cu, and Pb. With Atomic Absorption Spectroscopy Analysis Method, we quantified Cd. This study have been completed by measuring NOx SO2 and solid suspended particles or airborne particulate matter (APM).

ARM Airborne Continuous carbon dioxide measurements

DOE Data Explorer

Biraud, Sebastien

2013-03-26

The heart of the AOS CO2 Airborne Rack Mounted Analyzer System is the AOS Manifold. The AOS Manifold is a nickel coated aluminum analyzer and gas processor designed around two identical nickel-plated gas cells, one for reference gas and one for sample gas. The sample and reference cells are uniquely designed to provide optimal flushing efficiency. These cells are situated between a black-body radiation source and a photo-diode detection system. The AOS manifold also houses flow meters, pressure sensors and control valves. The exhaust from the analyzer flows into a buffer volume which allows for precise pressure control of the analyzer. The final piece of the analyzer is the demodulator board which is used to convert the DC signal generated by the analyzer into an AC response. The resulting output from the demodulator board is an averaged count of CO2 over a specified hertz cycle reported in volts and a corresponding temperature reading. The system computer is responsible for the input of commands and therefore works to control the unit functions such as flow rate, pressure, and valve control.The remainder of the system consists of compressors, reference gases, air drier, electrical cables, and the necessary connecting plumbing to provide a dry sample air stream and reference air streams to the AOS manifold.

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

Code of Federal Regulations, 2013 CFR

2013-07-01

... Chloride and Copolymers Production Testing and Compliance Requirements § 63.11930 What requirements must I...) Zero air (less than 10 parts per million by volume hydrocarbon in air). (B) Mixtures of methane in air at a concentration less than 10,000 parts per million by volume. A calibration gas other than methane...

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

Code of Federal Regulations, 2012 CFR

2012-07-01

... Chloride and Copolymers Production Testing and Compliance Requirements § 63.11930 What requirements must I...) Zero air (less than 10 parts per million by volume hydrocarbon in air). (B) Mixtures of methane in air at a concentration less than 10,000 parts per million by volume. A calibration gas other than methane...

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 8. Operational Logic Flow Diagrams for a Generic Advanced Air Traffic Management system

DOT National Transportation Integrated Search

1974-02-01

The volume presents a description of the services a generic Advanced Air Traffic Management System (AATMS) should provide to the useres of the system to facilitate the safe, efficient flow of traffic. It provides a definition of the functions which t...

High-Collection-Efficiency Fluorescence Detection Cell

NASA Technical Reports Server (NTRS)

Hanisco, Thomas; Cazorla, Maria; Swanson, Andrew

2013-01-01

A new fluorescence cell has been developed for the laser induced fluorescence (LIF) detection of formaldehyde. The cell is used to sample a flow of air that contains trace concentrations of formaldehyde. The cell provides a hermetically sealed volume in which a flow of air containing formaldehyde can be illuminated by a laser. The cell includes the optics for transmitting the laser beam that is used to excite the formaldehyde and for collecting the resulting fluorescence. The novelty of the cell is its small size and simple design that provides a more robust and cheaper alternative to the state of the art. Despite its simplicity, the cell provides the same sensitivity to detection as larger, more complicated cells.

Characterization of outdoor air particles as source of impurities in supply air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pasanen, P.; Kalliokoski, P.; Tuomainen, A.

1997-12-31

Odor emission of supply air filters has proved to be a major source of stuffy odor of supply air. In this study, the odor emission characteristics of outdoor air particles and odor emissions of coarse prefilters and fine filters were studied. The outdoor air samples were collected by the aid of high volume impactor. Odor emissions of the size fractions, < 2.1 {micro}m , 2.1--10 {micro}m and >10 {micro}m were studied separately in laboratory with a trained olf panel: The odor emissions of the ventilation filters in real use were evaluated five times during the 14 month study period. Aftermore » the field evaluation the emissions of carbonyl compounds and other volatile organic compounds. The odor emissions of outdoor air particles were the highest during the heating season and lowest in the summer. The particles in the coarsest fraction had the most abundant emissions (1,200 olf/g) while the emissions from fine particles were lowest (100 olf/g). The odor emissions evaluated from the coarse and fine ventilation filters supported the finding that particles collected on coarse prefilter had the most abundant odor emission.« less

40 CFR Appendix B to Part 50 - Reference Method for the Determination of Suspended Particulate Matter in the Atmosphere (High...

Code of Federal Regulations, 2010 CFR

2010-07-01

... conditions (25 °C, 760 mm Hg [101 kPa]), is determined from the measured flow rate and the sampling time. The... conveniently. c. Preclude leaks that would cause error in the measurement of the air volume passing through the... through the filter. b. Be rectangular in shape with a gabled roof, similar to the design shown in Figure 1...

40 CFR Appendix B to Part 50 - Reference Method for the Determination of Suspended Particulate Matter in the Atmosphere (High...

Code of Federal Regulations, 2011 CFR

2011-07-01

... conditions (25 °C, 760 mm Hg [101 kPa]), is determined from the measured flow rate and the sampling time. The... conveniently. c. Preclude leaks that would cause error in the measurement of the air volume passing through the... through the filter. b. Be rectangular in shape with a gabled roof, similar to the design shown in Figure 1...

Analysis of problems and failures in the measurement of soil-gas radon concentration.

PubMed

Neznal, Martin; Neznal, Matěj

2014-07-01

Long-term experience in the field of soil-gas radon concentration measurements allows to describe and explain the most frequent causes of failures, which can appear in practice when various types of measurement methods and soil-gas sampling techniques are used. The concept of minimal sampling depth, which depends on the volume of the soil-gas sample and on the soil properties, is shown in detail. Consideration of minimal sampling depth at the time of measurement planning allows to avoid the most common mistakes. The ways how to identify influencing parameters, how to avoid a dilution of soil-gas samples by the atmospheric air, as well as how to recognise inappropriate sampling methods are discussed. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Pressure and volume changes of tracheal tube cuff following inflation with various inflating agents during nitrous oxide anesthesia.

PubMed

Bajaj, Pramila; Nanda, Rajan; Goyal, Pradeep KR

2004-10-01

The study was designed to investigate the changes in pressure and volume of a tracheal tube-cuff inflated with air, mixture of N2O + O2, saline and 4% lidocaine during nitrous oxide anesthesia. This study was conducted in 80 patients (33 male & 47 female). The pressure and volume of a tracheal tube cuff increased with air, decreased with mixture of N2O + O2 and almost remained the same with saline and 4% lidocaine. The complications were more in the air group.

[Spirograph for small laboratory animals].

PubMed

Daniiarov, S B; Lanskiĭ, Iu M; Bebinov, E M

1986-10-01

A design of dry spirograph is described. It is characterized by greater precision, lack of inertia, high reliability, absence of respiration resistance, adequate form of recording, rapid resetting to any respiratory rate. The device consists of two similar injection syringes, photoelectric sensor for the identification of the initial moments of respiration stages, electromagnetic valves, two photoelectric converters of the air volume into the impulse signal, vacuum micro-pump, microcompressor and a system of air-driving tubes. In the initial position of pistons and valves the microcompressor pumps air into the inhalation cylinder and lifts the piston to the upper extreme position. With the signal marking the beginning of inspiration, the valves switch over and the piston lowers, pushing out the air, which moves into the animals' respiratory organs. Simultaneously, the signals of the inhaled air volume from the photoelectric transducer reach the recorder. During expiration the air pushes the piston down into the second cylinder and photoelectric transducer gives the information on the volume of the expired air.

Apparatus and method for maintaining an article at a temperature that is less than the temperature of the ambient air

DOE Office of Scientific and Technical Information (OSTI.GOV)

Klett, James; Klett, Lynn

An apparatus for maintaining the temperature of an article at a temperature that is below the ambient air temperature includes an enclosure having an outer wall that defines an interior chamber for holding a volume of sealed air. An insert is disposed inside of the chamber and has a body that is made of a porous graphite foam material. A vacuum pump penetrates the outer wall and fluidly connects the sealed air in the interior chamber with the ambient air outside of the enclosure. The temperatures of the insert and article is maintained at temperatures that are below the ambientmore » air temperature when a volume of a liquid is wicked into the pores of the porous insert and the vacuum pump is activated to reduce the pressure of a volume of sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid.« less

Air Quality measurements near the Gulf of Mexico Deep Water Horizon Oil Spill site in July 2010

NASA Astrophysics Data System (ADS)

Schade, G. W.; Rasmussen, R.; Conlee, D.; Seroka, G.; Delao, D.

2010-12-01

Eight whole air samples were acquired within several kilometers of the Deepwater Horizon well head location between 5 and 13 July 2010. A Teflon coated pump was used to pressurize 0.8 L volume stainless steel canisters to approximately 2 bar. Various amounts of oil were visible on the water surface during most sampling times, and some samples were accompanied by strong hydrocarbon smells. The air samples were analyzed over the next two months using high sensitivity GC-FID and GC-MS methods for C1-C30 hydrocarbons and selected hetero-atomic compounds. Highest concentrations reached several ppm for total hydrocarbons, comparable to concentrations in highway road tunnels. None of the samples showed elevated concentrations suggestive of hazardous concentrations, or near OSHA PEL or NIOSH REL levels. Consistent with studies of seawater methane concentrations at different depths, atmospheric methane mixing ratios were close to background abundances at 1.75-1.78 ppm, suggesting that the spill’s methane emissions had not reached the surface at that time. Non-methane hydrocarbons presented a highly complex mixture (100+ species) of dominantly alkanes, as expected. Linear alkanes were detected at elevated mixing ratios from C4 up to C30, and were dominated by nonane (C9). Aromatic hydrocarbons showed a pattern suggestive of a significant retention by seawater of benzene and toluene, the compounds with the highest water solubilities. While benzene was hardly and toluene only slightly elevated, lower solubility compounds such as the xylenes and naphthalene were clearly elevated. Data will be presented relative to an upwind sample taken on 5 July.

Particle Streak Anemometry: A New Method for Proximal Flow Sensing from Aircraft

NASA Astrophysics Data System (ADS)

Nichols, T. W.

Accurate sensing of relative air flow direction from fixed-wing small unmanned aircraft (sUAS) is challenging with existing multi-hole pitot-static and vane systems. Sub-degree direction accuracy is generally not available on such systems and disturbances to the local flow field, induced by the airframe, introduce an additional error source. An optical imaging approach to make a relative air velocity measurement with high-directional accuracy is presented. Optical methods offer the capability to make a proximal measurement in undisturbed air outside of the local flow field without the need to place sensors on vulnerable probes extended ahead of the aircraft. Current imaging flow analysis techniques for laboratory use rely on relatively thin imaged volumes and sophisticated hardware and intensity thresholding in low-background conditions. A new method is derived and assessed using a particle streak imaging technique that can be implemented with low-cost commercial cameras and illumination systems, and can function in imaged volumes of arbitrary depth with complex background signal. The new technique, referred to as particle streak anemometry (PSA) (to differentiate from particle streak velocimetry which makes a field measurement rather than a single bulk flow measurement) utilizes a modified Canny Edge detection algorithm with a connected component analysis and principle component analysis to detect streak ends in complex imaging conditions. A linear solution for the air velocity direction is then implemented with a random sample consensus (RANSAC) solution approach. A single DOF non-linear, non-convex optimization problem is then solved for the air speed through an iterative approach. The technique was tested through simulation and wind tunnel tests yielding angular accuracies under 0.2 degrees, superior to the performance of existing commercial systems. Air speed error standard deviations varied from 1.6 to 2.2 m/s depending on the techniques of implementation. While air speed sensing is secondary to accurate flow direction measurement, the air speed results were in line with commercial pitot static systems at low speeds.

Mechanisms and kinetics of granulated sewage sludge combustion.

PubMed

Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

2015-12-01

This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of meteorological parameters on air quality

NASA Astrophysics Data System (ADS)

Gioda, Adriana; Ventura, Luciana; Lima, Igor; Luna, Aderval

2013-04-01

The physical characterization representative of ambient air particle concentrations is becoming a topic of great interest for urban air quality monitoring and human exposure assessment. Human exposure to particulate matter of less than 2.5 µm in diameter (PM2.5) can result in a variety of adverse health impacts, including reduced lung function and premature mortality. Numerous studies have shown that fine airborne inhalable particulate matter particles (PM2.5) are more dangerous to human health than coarse particles, e.g. PM10. This study investigates meteorological parameter impacts on PM2.5 concentrations in the atmosphere of Rio de Janeiro, Brazil. Samples were collected during 24 h every six days using a high-volume sampler from six sites in the metropolitan area of Rio de Janeiro from January to December 2011. The particles mass was determined by Gravimetry. Meteorological parameters were obtained from automatic stations near the sampling sites. The average PM2.5 concentrations ranged from 9 to 32 µg/m3 for all sites, exceeding the suggested annual limit of WHO (10 µg/m3). The relationship between the effects of temperature, relative humidity, wind speed and direction and particle concentration was examined using a Principal Component Analysis (PCA) for the different sites and seasons. The results for each sampling point and season presented different principal component numbers, varying from 2 to 4, and extremely different relationships with the parameters. This clearly shows that changes in meteorological conditions exert a marked influence on air quality.

Effect of fiber material on ozone removal and carbonyl production from carpets

NASA Astrophysics Data System (ADS)

Abbass, Omed A.; Sailor, David J.; Gall, Elliott T.

2017-01-01

Indoor air quality is affected by indoor materials such as carpets that may act as sources and/or sinks of gas-phase air pollutants. Heterogeneous reactions of ozone with carpets may result in potentially harmful products. In this study, indoor residential carpets of varying fiber types were tested to evaluate their ability to remove ozone, and to assess their role in the production of carbonyls when exposed to elevated levels of ozone. Tests were conducted with six types of new unused carpets. Two sets of experiments were conducted, the first measured ozone removal and ozone deposition velocities, and the second measured primary carbonyl production and secondary production as a result of exposure to ozone. The tests were conducted using glass chambers with volume of 52 L each. Air exchange rates for all tests were 3 h-1. The ozone removal tests show that, for the conditions tested, the polyester carpet sample had the lowest ozone removal (40%), while wool carpet had the greatest ozone removal (65%). Most carpet samples showed higher secondary than primary carbonyl emissions, with carpets containing polypropylene fibers being a notable exception. Carpets with polyester fibers had both the highest primary and secondary emissions of formaldehyde among all samples tested. While it is difficult to make blanket conclusions about the relative air quality merits of various carpet fiber options, it is clear that ozone removal percentages and emissions of volatile organic compounds can vary drastically as a function of fiber type.

Physical-chemical characterization of the textile dye Azo Ab52 degradation by corona plasma

NASA Astrophysics Data System (ADS)

Gómez, A.; Torres-Arenas, A. J.; Vergara-Sánchez, J.; Torres, C.; Reyes, P. G.; Martínez, H.; Saldarriaga-Noreña, Hugo

2017-10-01

This work characterizes the degradation of the textile dye azo Acid Black 52 by measuring several physical and chemical parameters. A corona plasma was created at atmospheric pressure and applied on the liquid-air interface of water samples containing the dye. 1.0 mM of ferrous sulfate (FeSO4) was added to 1.0 mM dye solution, for a total volume of 250 mL. For each treatment, a number of parameters were quantified. These were voltage, current, temperature, loss of volume, pH, electrical conductivity, concentration, optical mission spectra, chemical oxygen demand (COD), total organic carbon (TOC), and the removal ratio. Because of the increase in the sample temperature, the volume lost by evaporation was explored. The results show that the efficiency of the dye degradation by plasma is a function of treatment time. Moreover, the reactive concentration of FeSO4 and the exposition time of the plasma were varied at a constant volume, leading to the determination of the concentrations and optimal times. Considering the degradation and removal parameters, at the maximum treated time of 80 min, it found that COD was of 96.36%, TOC of 93.93%, and the removal ratio of 97.47%.

Pollen Characterization in Size Segregated Atmospheric Aerosol

NASA Astrophysics Data System (ADS)

Kolpakova, Anna; Hovorka, Jan; Klán, Miroslav

2017-12-01

The first stage of a High Volumetric Cascade Impactor - HiVol (BGI-900), used for sampling of aerosol particles larger than 10 micrometres in aerodynamic diameter, was tested for bioaerosol sampling. Low air flow-rate and low pressure-drop at the jets of the first stage and high air volume are advantageous parameters, which would favour the use of the first stage for bioaerosol sampling. The sampling went in urban, rural and background localities, Prague, Brezno and Laz respectively in the Czech Republic, in summer and autumn. Pollen was separated from the impaction substrate, polyurethane foam, into homogeneous deposit on Nylon filter. The homogeneity of the deposit varied within 4%. Representative portion of the deposit was analysed by a scanning electron microscopy - SEM. There were taken 485 SEM images from 12 samples in 3 localities. Pollen grains were identified in 295 SEM images and determined into 9 genus and 4 families. Median pollen grain concentrations/deformities were 9m-3/24%, 3m-3/18%, 8m-3/50% for Prague, Brezno and Láz localities respectively. The pollen grains of the Poaceae family were found with the highest frequency in all localities. Number of pollen increased with total aerosol mass in Prague locality only. There were also identified brochosomes, rather unique insect secretion products, in the samples from the Láz locality.

Measurement of absolute regional lung air volumes from near-field x-ray speckles.

PubMed

Leong, Andrew F T; Paganin, David M; Hooper, Stuart B; Siew, Melissa L; Kitchen, Marcus J

2013-11-18

Propagation-based phase contrast x-ray (PBX) imaging yields high contrast images of the lung where airways that overlap in projection coherently scatter the x-rays, giving rise to a speckled intensity due to interference effects. Our previous works have shown that total and regional changes in lung air volumes can be accurately measured from two-dimensional (2D) absorption or phase contrast images when the subject is immersed in a water-filled container. In this paper we demonstrate how the phase contrast speckle patterns can be used to directly measure absolute regional lung air volumes from 2D PBX images without the need for a water-filled container. We justify this technique analytically and via simulation using the transport-of-intensity equation and calibrate the technique using our existing methods for measuring lung air volume. Finally, we show the full capabilities of this technique for measuring regional differences in lung aeration.

The performance of the progressive resolution optimizer (PRO) for RapidArc planning in targets with low-density media.

PubMed

Kan, Monica W K; Leung, Lucullus H T; Yu, Peter K N

2013-11-04

A new version of progressive resolution optimizer (PRO) with an option of air cavity correction has been implemented for RapidArc volumetric-modulated arc therapy (RA). The purpose of this study was to compare the performance of this new PRO with the use of air cavity correction option (PRO10_air) against the one without the use of the air cavity correction option (PRO10_no-air) for RapidArc planning in targets with low-density media of different sizes and complexities. The performance of PRO10_no-air and PRO10_air was initially compared using single-arc plans created for four different simple heterogeneous phantoms with virtual targets and organs at risk. Multiple-arc planning of 12 real patients having nasopharyngeal carcinomas (NPC) and ten patients having non-small cell lung cancer (NSCLC) were then performed using the above two options for further comparison. Dose calculations were performed using both the Acuros XB (AXB) algorithm with the dose to medium option and the analytical anisotropic algorithm (AAA). The effect of using intermediate dose option after the first optimization cycle in PRO10_air and PRO10_no-air was also investigated and compared. Plans were evaluated and compared using target dose coverage, critical organ sparing, conformity index, and dose homogeneity index. For NSCLC cases or cases for which large volumes of low-density media were present in or adjacent to the target volume, the use of the air cavity correction option in PRO10 was shown to be beneficial. For NPC cases or cases for which small volumes of both low- and high-density media existed in the target volume, the use of air cavity correction in PRO10 did not improve the plan quality. Based on the AXB dose calculation results, the use of PRO10_air could produce up to 18% less coverage to the bony structures of the planning target volumes for NPC cases. When the intermediate dose option in PRO10 was used, there was negligible difference observed in plan quality between optimizations with and without using the air cavity correction option.

Water content contribution in calculus phantom ablation during Q-switched Tm:YAG laser lithotripsy.

PubMed

Zhang, Jian J; Rajabhandharaks, Danop; Xuan, Jason Rongwei; Wang, Hui; Chia, Ray W J; Hasenberg, Tom; Kang, Hyun Wook

2015-01-01

Q-switched (QS) Tm:YAG laser ablation mechanisms on urinary calculi are still unclear to researchers. Here, dependence of water content in calculus phantom on calculus ablation performance was investigated. White gypsum cement was used as a calculus phantom model. The calculus phantoms were ablated by a total 3-J laser pulse exposure (20 mJ, 100 Hz, 1.5 s) and contact mode with N=15 sample size. Ablation volume was obtained on average 0.079, 0.122, and 0.391  mm3 in dry calculus in air, wet calculus in air, and wet calculus in-water groups, respectively. There were three proposed ablation mechanisms that could explain the effect of water content in calculus phantom on calculus ablation performance, including shock wave due to laser pulse injection and bubble collapse, spallation, and microexplosion. Increased absorption coefficient of wet calculus can cause stronger spallation process compared with that caused by dry calculus; as a result, higher calculus ablation was observed in both wet calculus in air and wet calculus in water. The test result also indicates that the shock waves generated by short laser pulse under the in-water condition have great impact on the ablation volume by Tm:YAG QS laser.

Biofiltration of methanol vapor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shareefdeen, Z.; Baltzis, B.C.; Oh, Youngsook

1993-03-05

Biofiltration of solvent and fuel vapors may offer a cost-effective way to comply with increasingly strict air emission standards. An important step in the development of this technology is to derive and validate mathematical models of the biofiltration process for predictive and scaleup calculations. For the study of methanol vapor biofiltration, an 8-membered bacterial consortium was obtained from methanol-exposed soil. The bacteria were immobilized on solid support and packed into a 5-cm diameter, 60-cm-high column provided with appropriate flowmeters and sampling ports. The solid support was prepared by mixing two volumes of peat with three volumes of perlite particles. Twomore » series of experiments were performed. In the first, the inlet methanol concentration was kept constant while the superficial air velocity was varied from run to run. In the second series, the air flow rate (velocity) was kept constant while the inlet methanol concentration was varied. The unit proved effective in removing methanol at rates up to 112.8 g h[sup [minus]1] m[sup [minus]3] packing. A mathematical model has been derived and validated. The model described and predicted experimental results closely. Both experimental data and model predictions suggest that the methanol biofiltration process was limited by oxygen diffusion and methanol degradation kinetics.« less

Shrinkage and porosity evolution during air-drying of non-cellular food systems: Experimental data versus mathematical modelling.

PubMed

Nguyen, Thanh Khuong; Khalloufi, Seddik; Mondor, Martin; Ratti, Cristina

2018-01-01

In the present work, the impact of glass transition on shrinkage of non-cellular food systems (NCFS) during air-drying will be assessed from experimental data and the interpretation of a 'shrinkage' function involved in a mathematical model. Two NCFS made from a mixture of water/maltodextrin/agar (w/w/w: 1/0.15/0.015) were created out of maltodextrins with dextrose equivalent 19 (MD19) or 36 (MD36). The NCFS made with MD19 had 30°C higher Tg than those with MD36. This information indicated that, during drying, the NCFS with MD19 would pass from rubbery to glassy state sooner than NCFS MD36, for which glass transition only happens close to the end of drying. For the two NCFS, porosity and volume reduction as a function of moisture content were captured with high accuracy when represented by the mathematical models previously developed. No significant differences in porosity and in maximum shrinkage between both samples during drying were observed. As well, no change in the slope of the shrinkage curve as a function of moisture content was perceived. These results indicate that glass transition alone is not a determinant factor in changes of porosity or volume during air-drying. Copyright © 2017 Elsevier Ltd. All rights reserved.

Validation of two-dimensional and three-dimensional measurements of subpleural alveolar size parameters by optical coherence tomography

PubMed Central

Warger, William C.; Hostens, Jeroen; Namati, Eman; Birngruber, Reginald; Bouma, Brett E.; Tearney, Guillermo J.

2012-01-01

Abstract. Optical coherence tomography (OCT) has been increasingly used for imaging pulmonary alveoli. Only a few studies, however, have quantified individual alveolar areas, and the validity of alveolar volumes represented within OCT images has not been shown. To validate quantitative measurements of alveoli from OCT images, we compared the cross-sectional area, perimeter, volume, and surface area of matched subpleural alveoli from microcomputed tomography (micro-CT) and OCT images of fixed air-filled swine samples. The relative change in size between different alveoli was extremely well correlated (r>0.9, P<0.0001), but OCT images underestimated absolute sizes compared to micro-CT by 27% (area), 7% (perimeter), 46% (volume), and 25% (surface area) on average. We hypothesized that the differences resulted from refraction at the tissue–air interfaces and developed a ray-tracing model that approximates the reconstructed alveolar size within OCT images. Using this model and OCT measurements of the refractive index for lung tissue (1.41 for fresh, 1.53 for fixed), we derived equations to obtain absolute size measurements of superellipse and circular alveoli with the use of predictive correction factors. These methods and results should enable the quantification of alveolar sizes from OCT images in vivo. PMID:23235834

Validation of two-dimensional and three-dimensional measurements of subpleural alveolar size parameters by optical coherence tomography

NASA Astrophysics Data System (ADS)

Unglert, Carolin I.; Warger, William C.; Hostens, Jeroen; Namati, Eman; Birngruber, Reginald; Bouma, Brett E.; Tearney, Guillermo J.

2012-12-01

Optical coherence tomography (OCT) has been increasingly used for imaging pulmonary alveoli. Only a few studies, however, have quantified individual alveolar areas, and the validity of alveolar volumes represented within OCT images has not been shown. To validate quantitative measurements of alveoli from OCT images, we compared the cross-sectional area, perimeter, volume, and surface area of matched subpleural alveoli from microcomputed tomography (micro-CT) and OCT images of fixed air-filled swine samples. The relative change in size between different alveoli was extremely well correlated (r>0.9, P<0.0001), but OCT images underestimated absolute sizes compared to micro-CT by 27% (area), 7% (perimeter), 46% (volume), and 25% (surface area) on average. We hypothesized that the differences resulted from refraction at the tissue-air interfaces and developed a ray-tracing model that approximates the reconstructed alveolar size within OCT images. Using this model and OCT measurements of the refractive index for lung tissue (1.41 for fresh, 1.53 for fixed), we derived equations to obtain absolute size measurements of superellipse and circular alveoli with the use of predictive correction factors. These methods and results should enable the quantification of alveolar sizes from OCT images in vivo.

Quantitative computed tomography versus spirometry in predicting air leak duration after major lung resection for cancer.

PubMed

Ueda, Kazuhiro; Kaneda, Yoshikazu; Sudo, Manabu; Mitsutaka, Jinbo; Li, Tao-Sheng; Suga, Kazuyoshi; Tanaka, Nobuyuki; Hamano, Kimikazu

2005-11-01

Emphysema is a well-known risk factor for developing air leak or persistent air leak after pulmonary resection. Although quantitative computed tomography (CT) and spirometry are used to diagnose emphysema, it remains controversial whether these tests are predictive of the duration of postoperative air leak. Sixty-two consecutive patients who were scheduled to undergo major lung resection for cancer were enrolled in this prospective study to define the best predictor of postoperative air leak duration. Preoperative factors analyzed included spirometric variables and area of emphysema (proportion of the low-attenuation area) that was quantified in a three-dimensional CT lung model. Chest tubes were removed the day after disappearance of the air leak, regardless of pleural drainage. Univariate and multivariate proportional hazards analyses were used to determine the influence of preoperative factors on chest tube time (air leak duration). By univariate analysis, site of resection (upper, lower), forced expiratory volume in 1 second, predicted postoperative forced expiratory volume in 1 second, and area of emphysema (< 1%, 1% to 10%, > 10%) were significant predictors of air leak duration. By multivariate analysis, site of resection and area of emphysema were the best independent determinants of air leak duration. The results were similar for patients with a smoking history (n = 40), but neither forced expiratory volume in 1 second nor predicted postoperative forced expiratory volume in 1 second were predictive of air leak duration. Quantitative CT is superior to spirometry in predicting air leak duration after major lung resection for cancer. Quantitative CT may aid in the identification of patients, particularly among those with a smoking history, requiring additional preventive procedures against air leak.

Exposure to Severe Urban Air Pollution Influences Cognitive Outcomes, Brain Volume and Systemic Inflammation in Clinically Healthy Children

ERIC Educational Resources Information Center

Calderon-Garciduenas, Lilian; Engle, Randall; Mora-Tiscareno, Antonieta; Styner, Martin; Gomez-Garza, Gilberto; Zhu, Hongtu; Jewells, Valerie; Torres-Jardon, Ricardo; Romero, Lina; Monroy-Acosta, Maria E.; Bryant, Christopher; Gonzalez-Gonzalez, Luis Oscar; Medina-Cortina, Humberto; D'Angiulli, Amedeo

2011-01-01

Exposure to severe air pollution produces neuroinflammation and structural brain alterations in children. We tested whether patterns of brain growth, cognitive deficits and white matter hyperintensities (WMH) are associated with exposures to severe air pollution. Baseline and 1 year follow-up measurements of global and regional brain MRI volumes,…

Main rotor free wake geometry effects on blade air loads and response for helicopters in steady maneuvers. Volume 2: Program listings

NASA Technical Reports Server (NTRS)

Sadler, S. G.

1972-01-01

A mathematical model and computer program was implemented to study the main rotor free wake geometry effects on helicopter rotor blade air loads and response in steady maneuvers. Volume 1 (NASA CR-2110) contains the theoretical formulation and analysis of results. Volume 2 contains the computer program listing.

Crude oil contaminated soil washing in air sparging assisted stirred tank reactor using biosurfactants.

PubMed

Urum, Kingsley; Pekdemir, Turgay; Ross, David; Grigson, Steve

2005-07-01

This study investigated the removal of crude oil from soil using air sparging assisted stirred tank reactors. Two surfactants (rhamnolipid and sodium dodecyl sulfate, SDS) were tested and the effects of different parameters (i.e. temperature, surfactant concentrations, washing time, volume/mass ratio) were investigated under varying washing modes namely, stirring only, air sparging only and the combination of stirring and air sparging. The results showed that SDS removed more than 80% crude oil from non-weathered soil samples, whilst rhamnolipid showed similar oil removal at the third and fourth levels of the parameters tested. The oil removal ability of the seawater prepared solutions were better than those of the distilled water solutions at the first and second levels of temperature and concentration of surfactant solutions. This approach of soil washing was noted to be effective in reducing the amount of oil in soil. Therefore we suggested that a field scale test be conducted to assess the efficiency of these surfactants.

Increasing the Air Charge and Scavenging the Clearance Volume of a Compression-Ignition Engine

NASA Technical Reports Server (NTRS)

Spanogle, J A; Hicks, C W; Foster, H H

1934-01-01

The object of the investigation presented in this report was to determine the effects of increasing the air charge and scavenging the clearance volume of a 4-stroke-cycle compression-ignition engine having a vertical-disk form combustion chamber. Boosting the inlet-air pressure with normal valve timing increased the indicated engine power in proportion to the additional air inducted and resulted in smoother engine operation with less combustion shock. Scavenging the clearance volume by using a valve overlap of 145 degrees and an inlet-air boost pressure of approximately 2 1/2 inches of mercury produced a net increase in performance for clear exhaust operation of 33 percent over that obtained with normal valve timing and the same boost pressure. The improved combustion characteristics result in lower specific fuel consumption, and a clearer exhaust.

Volume measuring system

NASA Technical Reports Server (NTRS)

Oele, J. S.

1975-01-01

Chamber is designed to be airtight; it includes face mask for person to breathe outside air so that he does not disturb chamber environment. Chamber includes piston to vary air volume inside. Also included are two microphone transducers which record pressure information inside chamber.

Air pressure changes in the creation and bursting of the type-1 big bubble in deep anterior lamellar keratoplasty: an ex vivo study.

PubMed

AlTaan, S L; Mohammed, I; Said, D G; Dua, H S

2018-01-01

PurposeTo measure the pressure and volume of air required to create a big bubble (BB) in simulated deep anterior lamellar keratoplasty (DALK) in donor eyes and ascertain the bursting pressure of the BB.Patients and methodsTwenty-two human sclera-corneal discs were used. Air was injected into the corneal stroma to create a BB and the pressure measured by means of a pressure converter attached to the system via a side port. A special clamp was designed to prevent air leak from the periphery of the discs. The pressure at which air emerged in the corneal tissue; the bursting pressure measured after advancing the needle into the bubble cavity and injecting more air; the volume of air required to create a BB and the volume of the BB were ascertained.ResultsType-1 BB were achieved in 19 and type-2 BB in 3 eyes. The maximum pressure reached to create a BB was 96.25+/- 21.61 kpa; the mean type-1 intrabubble pressure was 10.16 +/- 3.65 kpa. The mean bursting pressure of a type-1 BB was 66.65 +/- 18.65 kpa, while that of a type-2 BB was 14.77 +/- 2.44 kpa. The volume of air required to create a type-1 BB was 0.54 ml and the volume of a type-1 BB was consistently 0.1 ml.ConclusionsDua's layer baring DALK can withstand high intraoperative pressures compared to Descemet's membrane baring DALK. The study suggests that it could be safe to undertake procedures such as DALK-triple with a type-1 BB but not with a type-2 BB.

Effect of body position on respiratory system volumes in anesthetized red-tailed hawks (Buteo jamaicensis) as measured via computed tomography.

PubMed

Malka, Shachar; Hawkins, Michelle G; Jones, James H; Pascoe, Peter J; Kass, Philip H; Wisner, Erik R

2009-09-01

To determine the effects of body position on lung and air-sac volumes in anesthetized and spontaneously breathing red-tailed hawks (Buteo jamaicensis). 6 adult red-tailed hawks (sex unknown). A crossover study design was used for quantitative estimation of lung and air-sac volumes in anesthetized hawks in 3 body positions: dorsal, right lateral, and sternal recumbency. Lung volume, lung density, and air-sac volume were calculated from helical computed tomographic (CT) images by use of software designed for volumetric analysis of CT data. Effects of body position were compared by use of repeated-measures ANOVA and a paired Student t test. Results for all pairs of body positions were significantly different from each other. Mean +/- SD lung density was lowest when hawks were in sternal recumbency (-677 +/- 28 CT units), followed by right lateral (-647 +/- 23 CT units) and dorsal (-630 +/- 19 CT units) recumbency. Mean lung volume was largest in sternal recumbency (28.6 +/- 1.5 mL), followed by right lateral (27.6 +/- 1.7 mL) and dorsal (27.0 +/- 1.5 mL) recumbency. Mean partial air-sac volume was largest in sternal recumbency (27.0 +/- 19.3 mL), followed by right lateral (21.9 +/- 16.1 mL) and dorsal (19.3 +/- 16.9 mL) recumbency. In anesthetized red-tailed hawks, positioning in sternal recumbency resulted in the greatest lung and air-sac volumes and lowest lung density, compared with positioning in right lateral and dorsal recumbency. Additional studies are necessary to determine the physiologic effects of body position on the avian respiratory system.

Human exposures to volatile halogenated organic chemicals in indoor and outdoor air.

PubMed Central

Andelman, J B

1985-01-01

Volatile halogenated organic chemicals are found in indoor and outdoor air, often at concentrations substantially above those in remote, unpopulated areas. The outdoor ambient concentrations vary considerably among sampling stations throughout the United States, as well as diurnally and daily. The vapor pressures and air-water equilibrium (Henry's Law) constants of these chemicals influence considerably the likely relative human exposures for the air and water routes. Volatilization of chemicals from indoor uses of water can be a substantial source of exposure, as shown for radon-222. Measurements of air concentrations of trichloroethylene (TCE) in showers using TCE contaminated groundwater show increases with time to as high as one-third of occupational threshold limit values. Using a scaled down experimental shower, such volatilization and subsequent decay in air was also demonstrated. Using a simplified indoor air model and assuming complete volatilization from a full range of typical water uses within the home, calculations indicate that the expected air inhalation exposures can be substantially higher than those from ingestion of these chemicals in drinking water. Although the regulation of toxic chemicals in potable water supplies has focused traditionally on direct ingestion, the volatilization and inhalation from other much greater volume indoor uses of water should be considered as well. PMID:4085436

Airborne desert dust and aeromicrobiology over the Turkish Mediterranean coastline

USGS Publications Warehouse

Griffin, Dale W.; Kubilay, Nilgün; Kocak, Mustafa; Gray, Mike A.; Borden, Timothy C.; Shinn, Eugene A.

2007-01-01

Between 18 March and 27 October 2002, 220 air samples were collected on 209 of 224 calendar days, on top of a coastal atmospheric research tower in Erdemli, Turkey. The volume of air filtered for each sample was 340 liters. Two hundred fifty-seven bacterial and 2598 fungal colony forming units (CFU) were enumerated from the samples using a low-nutrient agar. Ground-based dust measurements demonstrated that the region is routinely impacted by dust generated regionally and from North Africa and that the highest combined percent recovery of total CFU and African dust deposition occurred in the month of April (93.4% of CFU recovery and 91.1% of dust deposition occurred during African dust days versus no African dust present, for that month). A statistically significant correlation was observed (peak regional African dust months of March, April and May; rs=0.576, P=0.000) between an increase in the prevalence of microorganisms recovered from atmospheric samples on dust days (regional and African as determined by ground-based dust measurements), versus that observed on non-dust days. Given the prevalence of atmospherically suspended desert dust and microorganisms observed in this study, and that culture-based studies typically only recover a small fraction (

[Method of fused sample preparation after nitrify-determination of primary and minor elements in manganese ore by X-ray fluorescence spectrometry].

PubMed

Song, Yi; Guo, Fen; Gu, Song-hai

2007-02-01

Eight components, i. e. Mn, SiO2, Fe, P, Al2O3, CaO, MgO and S, in manganese ore were determined by X-ray fluorescence spectrometer. Because manganese ore sample releases a lot of air bubbles during fusion which effect accuracy and reproducibility of determination, nitric acid was added to the sample to destroy organic matter before fusion by the mixture flux at 1000 degrees C. This method solved the problem that the flux splashed during fusion because organic matter volatilized brought out a lot of air bubbles, eliminated particle size effects and mineral effect, while solved the problem of volatilization of sulfur during fusion. The experiments for the selection of the sample preparation conditions, i. e. fusion flux, fusion time and volume of HNO3, were carried out. The matrix effects on absorption and enhancement were corrected by variable theoretical alpha coefficient to expand the range of determination. Moreover, the precision and accuracy experiments were performed. In comparison with chemical analysis method, the quantitative analytical results for each component are satisfactory. The method has proven rapid, precise and simple.

The Conference Proceedings of the 1998 Air Transport Research Group (ATRG) of the WCTR Society. Volume 1

NASA Technical Reports Server (NTRS)

Oum, Tae Hoon (Editor); Bowen, Brent D. (Editor)

1998-01-01

This report (Volume 1) is comprised of 5 sessions of the Air Transport Research Group (ATRG) Conference held in Antwerp, Belgium, July 1998. The sessions contain 3-4 papers (presentations) each. The session numbers and their respective headings are: (1) Airline alliances; (2) Airline Competition and Market Structure; (4) Liberalization, Open Skies, and Policy Issues; (5) Yield Management and Other Models; and (11) Air Traffic Control (ATC) and Air Navigational Systems (ANS).

Comprehensive Monitoring Program: Air Quality Data Assessment Report for FY90. Volume 2. Version 3.1

DTIC Science & Technology

1991-09-01

91311R01 If VERSION 3.10) VOLUME II Comm 2ND COPY COMPREHENSIVE MONITORING PROGRAM Contract Number DAAAI5-87-0095 AIR QUALITY DATA ASSESSMENT REPORT...MONITORING PROGRAM. FINAL AIR QUALITY DATA ASSESSMENT REPORT FOR FY90, VERSION 3.1 NONE 6. AUTHOR(S) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRES.S(S) 8...RELEASE; DISTRIBUTION IS UNLIMITED 13. ABSTRACT (Maximum 200 words) THE OBJECTIVE OF THIS CMP IS TO: VERIFY AND EVALUATE POTENTIAL AIR QUALITY HEALTH

Purge water management system

DOEpatents

Cardoso-Neto, J.E.; Williams, D.W.

1995-01-01

A purge water management system is described for effectively eliminating the production of purge water when obtaining a groundwater sample from a monitoring well. In its preferred embodiment, the purge water management system comprises an expandable container, a transportation system, and a return system. The purge water management system is connected to a wellhead sampling configuration, typically permanently installed at the well site. A pump, positioned with the monitoring well, pumps groundwater through the transportation system into the expandable container, which expands in direct proportion with volume of groundwater introduced, usually three or four well volumes, yet prevents the groundwater from coming into contact with the oxygen in the air. After this quantity of groundwater has been removed from the well, a sample is taken from a sampling port, after which the groundwater in the expandable container can be returned to the monitoring well through the return system. The purge water management system prevents the purge water from coming in contact with the outside environment, especially oxygen, which might cause the constituents of the groundwater to oxidize. Therefore, by introducing the purge water back into the monitoring well, the necessity of dealing with the purge water as a hazardous waste under the Resource Conservation and Recovery Act is eliminated.

Purge water management system

DOEpatents

Cardoso-Neto, Joao E.; Williams, Daniel W.

1996-01-01

A purge water management system for effectively eliminating the production of purge water when obtaining a groundwater sample from a monitoring well. In its preferred embodiment, the purge water management system comprises an expandable container, a transportation system, and a return system. The purge water management system is connected to a wellhead sampling configuration, typically permanently installed at the well site. A pump, positioned with the monitoring well, pumps groundwater through the transportation system into the expandable container, which expands in direct proportion with volume of groundwater introduced, usually three or four well volumes, yet prevents the groundwater from coming into contact with the oxygen in the air. After this quantity of groundwater has been removed from the well, a sample is taken from a sampling port, after which the groundwater in the expandable container can be returned to the monitoring well through the return system. The purge water management system prevents the purge water from coming in contact with the outside environment, especially oxygen, which might cause the constituents of the groundwater to oxidize. Therefore, by introducing the purge water back into the monitoring well, the necessity of dealing with the purge water as a hazardous waste under the Resource Conservation and Recovery Act is eliminated.

US Fish and Wildlife Service biomonitoring operations manual, Appendices A--K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gianotto, D.F.; Rope, R.C.; Mondecar, M.

1993-04-01

Volume 2 contains Appendices and Summary Sheets for the following areas: A-Legislative Background and Key to Relevant Legislation, B- Biomonitoring Operations Workbook, C-Air Monitoring, D-Introduction to the Flora and Fauna for Biomonitoring, E-Decontamination Guidance Reference Field Methods, F-Documentation Guidance, Sample Handling, and Quality Assurance/Quality Control Standard Operating Procedures, G-Field Instrument Measurements Reference Field Methods, H-Ground Water Sampling Reference Field Methods, I-Sediment Sampling Reference Field Methods, J-Soil Sampling Reference Field Methods, K-Surface Water Reference Field Methods. Appendix B explains how to set up strategy to enter information on the ``disk workbook``. Appendix B is enhanced by DE97006389, an on-line workbook formore » users to be able to make revisions to their own biomonitoring data.« less

Long-term observation of water-soluble chemical components and acid-digested metals in the total suspended particles collected at Okinawa, Japan

NASA Astrophysics Data System (ADS)

Handa, D.; Okada, K.; Kuroki, Y.; Nakama, Y.; Nakajima, H.; Somada, Y.; Ijyu, M.; Azechi, S.; Oshiro, Y.; Nakaema, F.; Miyagi, Y.; Arakaki, T.; Tanahara, A.

2011-12-01

The economic growth and population increase in recent Asia have been increasing air pollution. Emission rate of air pollutants from Asia, in particular oxides of nitrogen, surpassed those from North America and Europe and should continue to exceed them for decades. Okinawa Island is situated approximately 1500 km south of Tokyo, Japan, 2000 km southeast of Beijing, China, and 1000 km south of South Korea. Its location is ideal in observing East Asia's air quality because maritime air mass prevails during summer, while continental air mass dominates during fall, winter, and spring. The maritime air mass data can be seen as background clean air and can be compared with continental air masses which have been affected by anthropogenic activities. We collected total suspended particles (TSP) on quartz filters by using a high volume air sampler at the Cape Hedo Atmosphere and Aerosol Monitoring Station (CHAAMS), Okinawa, Japan during August 2005 and August 2010. Sampling duration was one week for each sample. We determined the concentrations of water-soluble anions, cations, water-soluble organic carbon (WSOC) and acid-digested metals in TSP samples using ion chromatography, atomic absorption spectrometry, total organic carbon analyzer and Inductively Coupled Plasma Mass spectrometry (ICP-MS), respectively. Seasonal variation of water-soluble chemical components and acid-digested metals showed that the concentrations were the lowest in summer, higher in fall and winter, and the highest in spring. When air mass came from Asian continent, the concentrations of water-soluble chemical components and acid-digested metals were much higher compared to the other directions, suggesting long-range transport of air pollutants from Asian continent. Also, when the air mass came from Asian continent (75-100% dominant), the mean concentrations of non-sea salt sulfate and nitrate increased ca. 1.8 times and ca. 3.7 times, respectively between 2005 and 2010, and the ratio of nitrate to non-sea salt sulfate increased ca. 50% which suggested that automobile exhaust emission increased. In addition, the concentration of soil-originated components such as iron and aluminum increased ca. 2.6 times and ca. 3.0 times, suggesting a probable desertification. We also report the calculated background concentrations of water-soluble chemical components and acid-digested metals at Okinawa, Japan.

Source identification of combustion-related air pollution during an episode and afterwards in winter-time in Istanbul.

PubMed

Kuzu, S Levent

2016-10-11

Conventional air pollutants (PM 10 , CO, NO x ) gradually increased from fall to winter during 2015 in Istanbul. Several air pollution episodes were observed during this period. This study was made in order to determine polycyclic aromatic hydrocarbon (PAH) levels, identify the sources of air pollution, and make toxicity assessment based on Benzo(a)pyrene equivalent concentrations. The sampling took 14 sequential days during winter. High-pressure weather conditions prevailed at the start of the sampling. The conditions were then changed to low-pressure condition towards the end of the sampling. Strong inversion was effective on the onset of the sampling. Strong inversion was effective at the onset of the sampling. A high-volume sampler was used to collect gas and particle phase samples. Total suspended particle concentrations were between 27 and 252 μg m -3 . Sixteen PAH species were investigated. Total (gas + particle) PAH concentrations were between 76.4 and 1280.3 ng m -3 , with an average of 301.4 ng m -3 . Individual PAH concentrations were between not detected (n.d.) and 99.2 ng m -3 in the gaseous phase, and between n.d. and 11.5 ng m -3 in the particle phase. Phenanthrene had the highest share among 16 PAH compounds. Benzo(a)pyrene was not detected in 8 days. On the remaining days, its concentration ranged between 5.5 and 14.8 ng m -3 with an average of 3.7 ng m -3 . Low-molecular-weight PAHs dominated gaseous phase; inversely, high-molecular-weight PAHs dominated particle phase. Possible sources were identified by diagnostic ratios. These ratios suggested that coal combustion and diesel vehicle exhaust emissions had a substantial impact on ambient air quality. Benzo(a)pyrene equivalencies were calculated for each PAH compound in order to make toxicity assessment. Total benzo(a)pyrene equivalencies ranged between 0.4 and 30.0 ng m -3 with an average of 7.2 ng m -3 .

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 3. Subsystem Functional Description.

DOT National Transportation Integrated Search

1974-02-01

The volume presents a detailed description of the subsystems that comprise the Satellite-Based Advanced Air Traffic Management System. Described in detail are the surveillance, navigation, communications, data processing, and airport subsystems. The ...

Automation Applications in an Advanced Air Traffic Management System : Volume 4A. Automation Requirements.

DOT National Transportation Integrated Search

1974-08-01

Volume 4 describes the automation requirements. A presentation of automation requirements is made for an advanced air traffic management system in terms of controller work force, computer resources, controller productivity, system manning, failure ef...

Supplementary Computer Generated Cueing to Enhance Air Traffic Controller Efficiency

DTIC Science & Technology

2013-03-01

assess the complexity of air traffic control (Mogford, Guttman, Morrow, & Kopardekar, 1995; Laudeman, Shelden, Branstrom, & Brasil , 1998). Controllers...Behaviorial Sciences: Volume 1: Methodological Issues Volume 2: Statistical Issues, 1, 257. Laudeman, I. V., Shelden, S. G., Branstrom, R., & Brasil

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 10. Subsystem Performance Requirements.

DOT National Transportation Integrated Search

1974-02-01

The volume presents the results of the subsystem performance requirements study for an Advanced Air Traffic Management System (AATMS). The study determined surveillance and navigation subsystem requirements for terminal and enroute area operations. I...

In Situ Biological Treatment Test at Kelly Air Force Base. Volume 2. Field Test Results and Cost Model.

DTIC Science & Technology

1987-07-01

degradation of organic contaminants. In situ treatment affects contaminants sorbed to soil as well as dissolved in groundwater. It is potentially ...indigenous soil micro - organisms to multiply and degrade the waste material. Exxon’s Baytown refinery has been disposing of oily wastes by land farming...Group (ERG). Chemical analyses performed on soil samples included priority pollutant volatile and metal compounds, total hydrocarbons (alkanes), oil and

United States Air Force Summer Faculty Research Program (1987). Program Technical Report. Volume 2.

DTIC Science & Technology

1987-12-01

the area of statistical inference, distribution theory and stochastic * •processes. I have taught courses in random processes and sample % j .functions...controlled phase separation of isotropic, binary mixtures, the theory of spinodal decomposition has been developed by Cahn and Hilliard.5 ,6 This theory is...peak and its initial rate of growth at a given temperature are predicted by the spinodal theory . The angle of maximum intensity is then determined by

Spacecraft Maximum Allowable Concentrations (SMACs) for C3 to C8 Aliphatic Saturated Aldehydes

NASA Technical Reports Server (NTRS)

Langford, Shannon D.

2007-01-01

Spacecraft maximum allowable concentrations (SMACs) for C3 to C8, straight-chain, aliphatic aldehydes have been previously assessed and have been documented in volume 4 of Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants (James, 2000). These aldehydes as well as associated physical properties are shown in Table 1. The C3 to C8 aliphatic aldehydes can enter the habitable compartments and contaminate breathing air of spacecraft by several routes including incomplete oxidation of alcohols in the Environmental Control and Life Support System (ECLSS) air revitalization subsystem, as a byproduct of human metabolism, through materials off-gassing, or during food preparation. These aldehydes have been detected in the atmosphere of manned space vehicles in the past. Analysis performed by NASA of crew cabin air samples from the Russian Mir Space Station revealed the presence of C3 to C8 aldehydes at concentrations peaking at approximately 0.1 mg/cu m.

International Space Station Urine Monitoring System Functional Integration and Science Testing

NASA Technical Reports Server (NTRS)

Rodriquez, Branelle R.; Broyan, James Lee, Jr.

2011-01-01

Exposure to microgravity during human spaceflight needs to be better understood as the human exploration of space requires longer duration missions. It is known that long term exposure to microgravity causes bone loss. Measuring the calcium and other metabolic byproducts in a crew member s urine can evaluate the effectiveness of bone loss countermeasures. The International Space Station (ISS) Urine Monitoring System (UMS) is an automated urine collection device designed to collect urine, separate the urine and air, measure the void volume, and allow for syringe sampling. Accurate measuring and minimal cross-contamination is essential to determine bone loss and the effectiveness of countermeasures. The ISS UMS provides minimal cross-contamination (<0.7 mL urine) and has volume accuracy of 2% between 100 to 1000 mL urine voids. Designed to provide a non-invasive means to collect urine samples from crew members, the ISS UMS operates in-line with the Node 3 Waste and Hygiene Compartment (WHC). The ISS UMS has undergone modifications required to interface with the WHC, including material changes, science algorithm improvements, and software platform revisions. Integrated functional testing was performed to determine the pressure drop, air flow rate, and the maximum amount of fluid capable of being discharged from the UMS to the WHC. This paper will detail the results of the science and the functional integration tests.

Geochemistry of aerosols from an urban site, Varanasi, in the Eastern Indo-Gangetic Plain

NASA Astrophysics Data System (ADS)

Ram, Kirpa; Norra, Stefan; Zirzov, Felix; Singh, Sunita; Mehra, Manisha; Nanad Tripathi, Sachichida

2016-04-01

PM2.5 aerosol samples were collected from an urban site, Varanasi, in the eastern Indo-Gangetic Plain on weekly basis during 19 March to 29 May 2015 (n=12), along with daily samples (n=8) during 11 to 18 March 2015 to study the geochemical and morphological features of aerosols. Samples were collected with a low volume sampler (Leckel GmbH, Germany) on the terrace of the Institute of Environment and Sustainable Development building, located in the Banaras Hindu University campus in the southern part of the city. Samples were analyzed for element concentration by Inductively Coupled Plasma Mass Spectrometry and particle morphology by Scanning Electron Microscope. PM2.5 concentration ranged between 22.3 and 70.5 μgm-3 in daily samples, whereas those varied between 52.0 and 106 μgm-3 in weekly samples. Lead, potassium, aluminum, zinc and iron have conspicuously higher concentrations with Pb concentration exceeding above the annual limit of 50 ngm-3 in four samples. First results show a trend of corresponding concentrations of chemical elements originated from anthropogenic and geogenic sources. The biogenic particles are a minor fraction of the total particulate aerosols. The Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back trajectory analysis of air parcels indicate that the air mass for the low loaded days originate from eastern directions including the region of the gulf of Bengal, where as high aerosols concentrations in cases of air masses arriving from north-western direction transporting the air pollutants from the Gangetic Plain towards Varanasi. Black carbon (BC) concentration, measured using an microaethalometer (AE-51), exhibit a strong variability (4.4 to 8.4 μg m-3) in the University campus which are ˜20-40% lower than those measured in the Varanasi city. The carbon content was found to be high with soot particles constituting the largest part in these samples and exist as single particle as well as attachment to other particles. The Cluster analysis shows a mixture of geogenic and anthropogenic emission sources, though their contribution could not be quantified in the present study. Thus further investigations are started with continuous aerosol sampling in Varanasi.

FAA Rotorcraft Research, Engineering, and Development Bibliography, 1962-1988. Supplement

DTIC Science & Technology

1989-03-01

fires, the aircraft engine was the major fire origin for twin- and single- engine air - craft. Only in single- engine aircraft was the instrument panel a...Certification Issues. The topics of Operational Requirements, Procedures, Air - worthiness and Engineering Capabilities are discussed. Volume II presents the...Issues. The topics of Operational Requirements, Procedures, Air - worthiness and Engineering Capabilities are discussed. Volume II presents the operator

Keeping the Edge. Air Force Materiel Command Cold War Context (1945-1991). Volume 3: Index

DTIC Science & Technology

2003-08-01

485 The Architects Collaborative (Harvard University) see Gropius , Walter , under Architects and Engineers, across the Department of Defense The...Sons (Newark, New Jersey) Volume II: 250 Graham, Anderson, Probst & White (Chicago) Volume II: 392, 455, 460, 461,475 Gropius , Walter ...models for Air Force research and development centers Gropius , Walter (The Architects Collaborative) see Architects and Engineers, across the

Numerical simulation of seismic wave propagation from land-excited large volume air-gun source

NASA Astrophysics Data System (ADS)

Cao, W.; Zhang, W.

2017-12-01

The land-excited large volume air-gun source can be used to study regional underground structures and to detect temporal velocity changes. The air-gun source is characterized by rich low frequency energy (from bubble oscillation, 2-8Hz) and high repeatability. It can be excited in rivers, reservoirs or man-made pool. Numerical simulation of the seismic wave propagation from the air-gun source helps to understand the energy partitioning and characteristics of the waveform records at stations. However, the effective energy recorded at a distance station is from the process of bubble oscillation, which can not be approximated by a single point source. We propose a method to simulate the seismic wave propagation from the land-excited large volume air-gun source by finite difference method. The process can be divided into three parts: bubble oscillation and source coupling, solid-fluid coupling and the propagation in the solid medium. For the first part, the wavelet of the bubble oscillation can be simulated by bubble model. We use wave injection method combining the bubble wavelet with elastic wave equation to achieve the source coupling. Then, the solid-fluid boundary condition is implemented along the water bottom. And the last part is the seismic wave propagation in the solid medium, which can be readily implemented by the finite difference method. Our method can get accuracy waveform of land-excited large volume air-gun source. Based on the above forward modeling technology, we analysis the effect of the excited P wave and the energy of converted S wave due to different water shapes. We study two land-excited large volume air-gun fields, one is Binchuan in Yunnan, and the other is Hutubi in Xinjiang. The station in Binchuan, Yunnan is located in a large irregular reservoir, the waveform records have a clear S wave. Nevertheless, the station in Hutubi, Xinjiang is located in a small man-made pool, the waveform records have very weak S wave. Better understanding of the characteristics of land-excited large volume air-gun can help to better use of the air-gun source.

Development of wear resistant NFSS-HA novel biocomposites and study of their tribological properties for orthopaedic applications.

PubMed

Younesi, M; Bahrololoom, M E; Fooladfar, H

2010-02-01

Implants made of nickel free austenitic stainless steel can reduce the toxic effect of released nickel ion and compounds from the conventional stainless steels. On the other hand, hydroxyapatite is a ceramic which has been used in orthopaedic applications due to its good osteoconductivity, biocompatibility and bioactivity. However, there is no evidence in the literature up to now on producing composites based on nickel free stainless steel and hydroxyapatite and study of their tribology. The aim of this work was to produce novel biocomposites made up of nickel free stainless steel with hydroxyapatite (prepared by heat treating bone ash) and studying their tribology under various loads in air and in Ringer's physiological solution. Different amounts of hydroxyapatite powder (10, 20, 30 and 40% Vol.) were added to this nickel free stainless steel powder to get the biocomposites. Variation of their density, hardness, wear resistance and friction with the ceramic (hydroxyapatite) content and wear load were investigated in air and in Ringer's solution. The density of the composites was decreased by increasing the volume percentage of the hydroxyapatite, while wear resistance of the composites was increased. The wear mechanism of these composites was changed by increasing the wear load and consequently the volume loss was enhanced dramatically. Furthermore, by increasing the sliding distance, the rate of volume loss was decreased slightly. The friction coefficient of the composites was also decreased by increasing the weight percentage of hydroxyapatite. Effect of the physiological Ringer's solution on wear resistance and friction coefficient of the composites was nearly negligible. The wear mechanisms of the samples were identified by studying the SEM images of the worn surfaces of the tested samples in different wear loads and HA contents. Copyright 2009 Elsevier Ltd. All rights reserved.

Experimental Determination of Air Density Using a 1 kg Mass Comparator in Vacuum

NASA Astrophysics Data System (ADS)

Gläser, M.; Schwartz, R.; Mecke, M.

1991-01-01

The density of ambient air has been determined by a straightforward experimental method. The apparent masses of two artefacts having about the same mass and surface, but different well-known volumes, have been compared by using a 1 kg balance in vacuum and in air. The differences of apparent masses and volumes yield the air density with a relative uncertainty (1σ) of 5 × 10-5. From measurements made using a third artefact, surface sorption effects caused by the change between vacuum and air conditions gave a coefficient of about 0,2 μg cm-2.

Radon in the Exhaled Air of Patients in Radon Therapy.

PubMed

Lettner, Herbert; Hubmer, Alexander; Hofmann, Werner; Landrichinger, Julia; Gaisberger, Martin; Winkler-Heil, Renate

2017-11-01

In the Gastein valley, numerous facilities use radon for the treatment of various diseases either by exposure to radon in air or in radon rich thermal water. In this study, six test persons were exposed to radon thermal water in a bathtub and the time-dependent radon activity concentration in the exhaled air was recorded. At temperatures between 38°C and 40°C, the radon activity concentration in the water was about 900 kBq/m3 in a total volume of 600 l, where the patients were exposed for 20 min, while continuously sampling the exhaled air during the bathing and 20 min thereafter. After entering the bath, the exhaled radon activity concentration rapidly increased, reaching some kind of saturation after 20 min exposure. The radon activity concentration in the exhaled air was about 8000 Bq/m3 at the maximum, with higher concentrations for male test persons. The total radon transfer from water to the exhaled air was between 480 and 1000 Bq, which is equivalent to 0.08% and 0.2% of the radon in the water. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Residues of 2, 4-D in air samples from Saskatchewan: 1966-1975.

PubMed

Grover, R; Kerr, L A; Wallace, K; Yoshida, K; Maybank, J

1976-01-01

Residues of 2,4-D (2,4-dichlorophenoxyacetic acid) in air samples from several sampling sites in central and southern Saskatchewan during the spraying seasons in the 1966-68 and 1970-75 periods were determined by gas-liquid chromatographic techniques. Initially, individual esters of 2,4-D were characterized by retention times and confirmed further by co-injection and dual column procedures. Since 1973, however, only total 2,4-D acid levels in air samples have been determined after esterification to the methyl ester and confirmed by gc/ms techniques whenever possible. Up to 50% of the daily samples collected during the spraying season at any of the locations and during any given year contained 2,4-D, with butyl esters being found most frequently. The daily 24-hr mean atmospheric concentrations of 2,4-D ranged from 0.01 to 1.22 mug/m3, 0.01 to 13.50 mug/m3, and 0.05 to 0.59 mug/m3 for the iso-propyl, mixed butyl and iso-octyl esters, respectively. Even when the samples were analysed for the total 2,4-D content, i.e. from 1973 onwards, the maximum level of the total acid reached only 23.14 mug/m3. In any given year and at any of the sampling sites, about 30% of the samples contained less than 0.01 mug/m3 of 2,4-D. In another 40% of the samples, the levels of 2,4-D ranged from 0.01 to 0.099 mug/m3. Only about 30% of the samples contained 2,4-D concentrations higher than 0.1 mug/m3, with only 10% or less exceeding 1 mug/m3. None of the samples, obtained with the high volume particulate sampler, showed any detectable levels of 2,4-D, indicating little or no transport of 2,4-D adsorbed on dust particles or as crystals of amine salts.

Breathing simulator of workers for respirator performance test

PubMed Central

YUASA, Hisashi; KUMITA, Mikio; HONDA, Takeshi; KIMURA, Kazushi; NOZAKI, Kosuke; EMI, Hitoshi; OTANI, Yoshio

2014-01-01

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. PMID:25382381

Thermodynamic correction of particle concentrations measured by underwing probes on fast-flying aircraft

NASA Astrophysics Data System (ADS)

Weigel, Ralf; Spichtinger, Peter; Mahnke, Christoph; Klingebiel, Marcus; Afchine, Armin; Petzold, Andreas; Krämer, Martina; Costa, Anja; Molleker, Sergej; Reutter, Philipp; Szakáll, Miklós; Port, Max; Grulich, Lucas; Jurkat, Tina; Minikin, Andreas; Borrmann, Stephan

2016-10-01

Particle concentration measurements with underwing probes on aircraft are impacted by air compression upstream of the instrument body as a function of flight velocity. In particular, for fast-flying aircraft the necessity arises to account for compression of the air sample volume. Hence, a correction procedure is needed to invert measured particle number concentrations to ambient conditions that is commonly applicable to different instruments to gain comparable results. In the compression region where the detection of particles occurs (i.e. under factual measurement conditions), pressure and temperature of the air sample are increased compared to ambient (undisturbed) conditions in certain distance away from the aircraft. Conventional procedures for scaling the measured number densities to ambient conditions presume that the air volume probed per time interval is determined by the aircraft speed (true air speed, TAS). However, particle imaging instruments equipped with pitot tubes measuring the probe air speed (PAS) of each underwing probe reveal PAS values systematically below those of the TAS. We conclude that the deviation between PAS and TAS is mainly caused by the compression of the probed air sample. From measurements during two missions in 2014 with the German Gulfstream G-550 (HALO - High Altitude LOng range) research aircraft we develop a procedure to correct the measured particle concentration to ambient conditions using a thermodynamic approach. With the provided equation, the corresponding concentration correction factor ξ is applicable to the high-frequency measurements of the underwing probes, each of which is equipped with its own air speed sensor (e.g. a pitot tube). ξ values of 1 to 0.85 are calculated for air speeds (i.e. TAS) between 60 and 250 m s-1. For different instruments at individual wing position the calculated ξ values exhibit strong consistency, which allows for a parameterisation of ξ as a function of TAS for the current HALO underwing probe configuration. The ability of cloud particles to adopt changes of air speed between ambient and measurement conditions depends on the cloud particles' inertia as a function of particle size (diameter Dp). The suggested inertia correction factor μ (Dp) for liquid cloud drops ranges between 1 (for Dp < 70 µm) and 0.8 (for 100 µm < Dp < 225 µm) but it needs to be applied carefully with respect to the particles' phase and nature. The correction of measured concentration by both factors, ξ and μ (Dp), yields higher ambient particle concentration by about 10-25 % compared to conventional procedures - an improvement which can be considered as significant for many research applications. The calculated ξ values are specifically related to the considered HALO underwing probe arrangement and may differ for other aircraft. Moreover, suggested corrections may not cover all impacts originating from high flight velocities and from interferences between the instruments and e.g. the aircraft wings and/or fuselage. Consequently, it is important that PAS (as a function of TAS) is individually measured by each probe deployed underneath the wings of a fast-flying aircraft.

Air elimination capability in rapid infusion systems.

PubMed

Zoremba, N; Gruenewald, C; Zoremba, M; Rossaint, R; Schaelte, G

2011-11-01

Pressure infusion devices are used in clinical practice to apply large volumes of fluid over a short period of time. Although air infusion is a major complication, they have limited capability to detect and remove air during pressure infusion. In this investigation, we tested the air elimination capabilities of the Fluido(®) (The Surgical Company), Level 1(®) (Level 1 Technologies Inc.) and Ranger(®) (Augustine Medical GmbH) pressure infusion devices. Measurements were undertaken with a crystalloid solution during an infusion flow of 100, 200, 400 and 800 ml.min(-1). Four different volumes of air (25, 50, 100 and 200 ml) were injected as boluses in one experimental setting, or infused continuously over the time needed to perfuse 2 l saline in the other setting. The perfusion fluid was collected in an airtight infusion bag and the amount of air obtained in the bag was measured. The delivered air volume was negligible and would not cause any significant air embolism in all experiments. In our experimental setting, we found, during high flow, an increased amount of uneliminated air in all used devices compared with lower perfusion flows. All tested devices had a good air elimination capability. The use of ultrasonic air detection coupled with an automatic shutoff is a significant safety improvement and can reliably prevent accidental air embolism at rapid flows. © 2011 The Authors. Anaesthesia © 2011 The Association of Anaesthetists of Great Britain and Ireland.

Installation Restoration Program. Phase 2. Confirmation/Quantification. Stage 1. Air Force Plant 4, Fort Worth, Texas. Volume 5. Appendix A-2.

DTIC Science & Technology

1987-12-01

Limit Spiked Samale Samole ISailced C" auod R sIus’lt (SSR) esult. (SR) A-dded ( .SA) Iels: I. I 1. A.luminum 75-125 - I Z. Antimony - 3. Arsenic " I...UntKtarix *s %Control Limit Spiked Samale Sample SieiCm.,ound _ _R R esult (SSR) Re t,.- (SR) Added (SA) Z,10 1. AUlunu m 7 I I I 2. Antimonyj ____ 3...No. DATE Lab Sample) ;S4 No Katrix waot, " . n ...Central L imi Spiked Samale Samale Spiked Comnpound M Rsult: (SSR) Result (SR) jAdded (SA) XR

Evaluation of active sampling strategies for the determination of 1,3-butadiene in air

NASA Astrophysics Data System (ADS)

Vallecillos, Laura; Maceira, Alba; Marcé, Rosa Maria; Borrull, Francesc

2018-03-01

Two analytical methods for determining levels of 1,3-butadiene in urban and industrial atmospheres were evaluated in this study. Both methods are extensively used for determining the concentration of volatile organic compounds in the atmosphere and involve collecting samples by active adsorptive enrichment on solid sorbents. The first method uses activated charcoal as the sorbent and involves liquid desorption with carbon disulfide. The second involves the use of a multi-sorbent bed with two graphitised carbons and a carbon molecular sieve as the sorbent, with thermal desorption. Special attention was paid to the optimization of the sampling procedure through the study of sample volume, the stability of 1,3-butadiene once inside the sampling tube and the humidity effect. In the end, the thermal desorption method showed better repeatability and limits of detection and quantification for 1,3-butadiene than the liquid desorption method, which makes the thermal desorption method more suitable for analysing air samples from both industrial and urban atmospheres. However, sampling must be performed with a pre-tube filled with a drying agent to prevent the loss of the adsorption capacity of the solid adsorbent caused by water vapour. The thermal desorption method has successfully been applied to determine of 1,3-butadiene inside a 1,3-butadiene production plant and at three locations in the vicinity of the same plant.

Mobile automatic metabolic analyzer

NASA Technical Reports Server (NTRS)

Bynum, B. G.; Currie, J. R.

1975-01-01

Two flexible pipes, attached to face mask, are connected to spirometers in mobile cart. Inhaled air volume is measured as it is drawn from one spirometer, and exhaled air volume is measured as it is breathed into second spirometer. Sensor is used to monitor heartbeat rate.

Automation Applications in an Advanced Air Traffic Management System : Volume 4B. Automation Requirements (Concluded)

DOT National Transportation Integrated Search

1974-08-01

Volume 4 describes the automation requirements. A presentation of automation requirements is made for an advanced air traffic management system in terms of controller work for-e, computer resources, controller productivity, system manning, failure ef...

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 5. System Performance.

DOT National Transportation Integrated Search

1974-02-01

The volume presents the results of the performance evaluation of the Satellite-Based Advanced Air Traffic Management System (SAATMS). The evaluation established the capacity, safety, and delay performance of the system for the Los Angeles Basin termi...

Control of gill ventilation and air-breathing in the bowfin amia calva

PubMed

Hedrick; Jones

1999-01-01

The purpose of this study was to investigate the roles of branchial and gas bladder reflex pathways in the control of gill ventilation and air-breathing in the bowfin Amia calva. We have previously determined that bowfin use two distinct air-breathing mechanisms to ventilate the gas bladder: type I air breaths are characterized by exhalation followed by inhalation, are stimulated by aquatic or aerial hypoxia and appear to regulate O2 gas exchange; type II air breaths are characterized by inhalation alone and possibly regulate gas bladder volume and buoyancy. In the present study, we test the hypotheses (1) that gill ventilation and type I air breaths are controlled by O2-sensitive chemoreceptors located in the branchial region, and (2) that type II air breaths are controlled by gas bladder mechanosensitive stretch receptors. Hypothesis 1 was tested by examining the effects of partial or complete branchial denervation of cranial nerves IX and X to the gill arches on gill ventilation frequency (fg) and the proportion of type I air breaths during normoxia and hypoxia; hypothesis II was tested by gas bladder inflation and deflation. Following complete bilateral branchial denervation, fg did not differ from that of sham-operated control fish; in addition, fg was not significantly affected by aquatic hypoxia in sham-operated or denervated fish. In sham-operated fish, aquatic hypoxia significantly increased overall air-breathing frequency (fab) and the percentage of type I breaths. In fish with complete IX-X branchial denervation, fab was also significantly increased during aquatic hypoxia, but there were equal percentages of type I and type II air breaths. Branchial denervation did not affect the frequency of type I air breaths during aquatic hypoxia. Gas bladder deflation via an indwelling catheter resulted in type II breaths almost exclusively; furthermore, fab was significantly correlated with the volume removed from the gas bladder, suggesting a volume-regulating function for type II air breaths. These results indicate that chronic (3-4 weeks) branchial denervation does not significantly affect fg or type I air-breathing responses to aquatic hypoxia. Because type I air-breathing responses to aquatic hypoxia persist after IX-X cranial nerve denervation, O2-sensitive chemoreceptors that regulate air-breathing may be carried in other afferent pathways, such as the pseudobranch. Gas bladder deflation reflexly stimulates type II breaths, suggesting that gas bladder volume-sensitive stretch receptors control this particular air-breathing mechanism. It is likely that type II air breaths function to regulate buoyancy when gas bladder volume declines during the inter-breath interval.

Method for monitoring stack gases for uranium activity

DOEpatents

Beverly, C.R.; Ernstberger, E.G.

1985-07-03

A method for monitoring the stack gases of a purge cascade of gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases. 1 fig.

Method for monitoring stack gases for uranium activity

DOEpatents

Beverly, Claude R.; Ernstberger, Harold G.

1988-01-01

A method for monitoring the stack gases of a purge cascade of a gaseous diffusion plant for uranium activity. A sample stream is taken from the stack gases and contacted with a volume of moisture-laden air for converting trace levels of uranium hexafluoride, if any, in the stack gases into particulate uranyl fluoride. A continuous strip of filter paper from a supply roll is passed through this sampling stream to intercept and gather any uranyl fluoride in the sampling stream. This filter paper is then passed by an alpha scintillation counting device where any radioactivity on the filter paper is sensed so as to provide a continuous monitoring of the gas stream for activity indicative of the uranium content in the stack gases.

Autologous fibrin sealant reduces the incidence of prolonged air leak and duration of chest tube drainage after lung volume reduction surgery: a prospective randomized blinded study.

PubMed

Moser, C; Opitz, I; Zhai, W; Rousson, V; Russi, E W; Weder, W; Lardinois, D

2008-10-01

Prolonged air leak is reported in up to 50% of patients after lung volume reduction surgery. The effect of an autologous fibrin sealant on the intensity and duration of air leak and on the time to chest drain removal after lung volume reduction surgery was investigated in a randomized prospective clinical trial. Twenty-five patients underwent bilateral thoracoscopic lung volume reduction surgery. In each patient, an autologous fibrin sealant was applied along the staple lines on one side, whereas no additional measure was taken on the other side. Randomization of treatment was performed at the end of the resection on the first side. Air leak was assessed semiquantitatively by use of a severity score (0 = no leak; 4 = continuous severe leak) by two investigators blinded to the treatment. Mean value of the total severity scores for the first 48 hours postoperative was significantly lower in the treated group (4.7 +/- 7.7) than in the control group (16.0 +/- 10.1) (P < .001), independently of the length of the resection. Prolonged air leak and mean duration of drainage were also significantly reduced after application of the sealant (4.5% and 2.8 +/- 1.9 days versus 31.8% and 5.9 +/- 2.9 days) (P = .03 and P < .001). Autologous fibrin sealant for reinforcement of the staple lines after lung volume reduction surgery significantly reduces prolonged air leak and duration of chest tube drainage.

Development of a syringe pump assisted dynamic headspace sampling technique for needle trap device.

PubMed

Eom, In-Yong; Niri, Vadoud H; Pawliszyn, Janusz

2008-07-04

This paper describes a new approach that combines needle trap devices (NTDs) with a dynamic headspace sampling technique (purge and trap) using a bidirectional syringe pump. The needle trap device is a 22-G stainless steel needle 3.5-in. long packed with divinylbenzene sorbent particles. The same sized needle, without packing, was used for purging purposes. We chose an aqueous mixture of benzene, toluene, ethylbenzene, and p-xylene (BTEX) and developed a sequential purge and trap (SPNT) method, in which sampling (trapping) and purging cycles were performed sequentially by the use of syringe pump with different distribution channels. In this technique, a certain volume (1 mL) of headspace was sequentially sampled using the needle trap; afterwards, the same volume of air was purged into the solution at a high flow rate. The proposed technique showed an effective extraction compared to the continuous purge and trap technique, with a minimal dilution effect. Method evaluation was also performed by obtaining the calibration graphs for aqueous BTEX solutions in the concentration range of 1-250 ng/mL. The developed technique was compared to the headspace solid-phase microextraction method for the analysis of aqueous BTEX samples. Detection limits as low as 1 ng/mL were obtained for BTEX by NTD-SPNT.

A study of optimum cowl shapes and flow port locations for minimum drag with effective engine cooling, volume 2

NASA Technical Reports Server (NTRS)

Fox, S. R.; Smetana, F. O.

1980-01-01

The listings, user's instructions, sample inputs, and sample outputs of two computer programs which are especially useful in obtaining an approximate solution of the viscous flow over an arbitrary nonlifting three dimensional body are provided. The first program performs a potential flow solution by a well known panel method and readjusts this initial solution to account for the effects of the boundary layer displacement thickness, a nonuniform but unidirectional onset flow field, and the presence of air intakes and exhausts. The second program is effectually a geometry package which allows the user to change or refine the shape of a body to satisfy particular needs without a significant amount of human intervention. An effort to reduce the cruise drag of light aircraft through an analytical study of the contributions to the drag arising from the engine cowl shape and the foward fuselage area and also that resulting from the cooling air mass flowing through intake and exhaust sites on the nacelle is presented. The programs may be effectively used to determine the appropriate body modifications or flow port locations to reduce the cruise drag as well as to provide sufficient air flow for cooling the engine.

Establishing a method to measure bone structure using spectral CT

NASA Astrophysics Data System (ADS)

Ramyar, M.; Leary, C.; Raja, A.; Butler, A. P. H.; Woodfield, T. B. F.; Anderson, N. G.

2017-03-01

Combining bone structure and density measurement in 3D is required to assess site-specific fracture risk. Spectral molecular imaging can measure bone structure in relation to bone density by measuring macro and microstructure of bone in 3D. This study aimed to optimize spectral CT methodology to measure bone structure in excised bone samples. MARS CT with CdTe Medipix3RX detector was used in multiple energy bins to calibrate bone structure measurements. To calibrate thickness measurement, eight different thicknesses of Aluminium (Al) sheets were scanned one in air and the other around a falcon tube and then analysed. To test if trabecular thickness measurements differed depending on scan plane, a bone sample from sheep proximal tibia was scanned in two orthogonal directions. To assess the effect of air on thickness measurement, two parts of the same human femoral head were scanned in two conditions (in the air and in PBS). The results showed that the MARS scanner (with 90μm voxel size) is able to accurately measure the Al (in air) thicknesses over 200μm but it underestimates the thicknesses below 200μm because of partial volume effect in Al-air interface. The Al thickness measured in the highest energy bin is overestimated at Al-falcon tube interface. Bone scanning in two orthogonal directions gives the same trabecular thickness and air in the bone structure reduced measurement accuracy. We have established a bone structure assessment protocol on MARS scanner. The next step is to combine this with bone densitometry to assess bone strength.

A multi-residue method for characterization of endocrine disruptors in gaseous and particulate phases of ambient air

NASA Astrophysics Data System (ADS)

Alliot, Fabrice; Moreau-Guigon, Elodie; Bourges, Catherine; Desportes, Annie; Teil, Marie-Jeanne; Blanchard, Martine; Chevreuil, Marc

2014-08-01

A number of semi-volatile compounds occur in indoor air most of them being considered as potent endocrine disruptors and thus, exerting a possible impact upon health. To assess their concentration levels in indoor air, we developed and validated a method for sampling and multi-residue analysis of 58 compounds including phthalates, polycyclic aromatic hydrocarbons (PAHs), polybromodiphenylethers (PBDEs), polychlorobiphenyls (PCBs), parabens, bisphenol A (BPA) and tetrabromobisphenol A (TBBPA) in gaseous and particulate phases of air. We validated each step of procedures from extraction until analysis. Matrice spiking were performed at extraction, fractionation and purification stages. The more volatile compounds were analyzed with a gas chromatography system coupled with a mass spectrometer (GC/MS) or with a tandem mass spectrometer (GC/MS/MS). The less volatile compounds were analyzed with a liquid chromatography system coupled with a tandem mass spectrometer (LC/MS/MS). Labeled internal standard method was used ensuring high quantification accuracy. The instrumental detection limits were under 1 pg for all compounds and therefore, a limit of quantification averaging 1 pg m-3 for the gaseous and the particulate phases and a volume of 150 m3, except for phthalates, phenol compounds and BDE-209. Satisfactory recoveries were found except for phenol compounds. That method was successfully applied to several indoor air samples (office, apartment and day nursery) and most of the targeted compounds were quantified, mainly occurring in the gaseous phase. The most abundant were phthalates (up to 918 ng m-3 in total air), followed by PCBs > parabens > BPA > PAHs > PBDEs.

Neuston Trawl and Whole Water Samples: A Comparison of Microplastic Sampling Techniques in The Gulf of Maine and Their Application to Citizen-Driven Science

NASA Astrophysics Data System (ADS)

Kautz, M.

2016-12-01

Microplastic research in aquatic environments has quickly evolved over the last decade. To have meaningful inter-study comparisons, it is necessary to define methodological criteria for both the sampling and sorting of microplastics. The most common sampling method used for sea surface samples has traditionally been a neuston net (NN) tow. Originally designed for plankton collection, neuston tows allow for a large volume of water to be sampled and can be coupled with phytoplankton monitoring. The widespread use of surface nets allows for easy comparison between data sets, but the units of measurement for calculating microplastic concentration vary, from surface area m2 and Km2, to volume of water sampled, m3. Contamination by the air, equipment, or sampler is a constant concern in microplastic research. Significant in-field contamination concerns for neuston tow sampling include air exposure time, microplastics in rinse water, sampler contact, and plastic net material. Seeking to overcome the lack of contamination control and the intrinsic instrumental size limitation associated with surface tow nets, we developed an alternative sampling method. The whole water (WW) method is a one-liter grab sample of surface water adapted from College of the Atlantic and Sea Education Association (SEA) student, Marina Garland. This is the only WW method that we are aware of being used to sample microplastic. The method addresses the increasing need to explore smaller size domains, to reduce potential contamination and to incorporate citizen scientists into data collection. Less water is analyzed using the WW method, but it allows for targeted sampling of point-source pollution, intertidal, and shallow areas. The WW methodology can easily be integrated into long-term or citizen science monitoring initiatives due to its simplicity and low equipment demands. The aim of our study was to demonstrate a practical and economically feasible method for sampling microplastic abundance at the micro (10-6m) and nano (10-8m) scale that can be used in a wide variety of environments, and for assessing spatial and temporal distributions. The method has been employed in a multi-year citizen science collaboration with Adventurers and Scientists for Conservation to study microplastic worldwide.

Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study.

PubMed

Choi, Sanghun; Hoffman, Eric A; Wenzel, Sally E; Castro, Mario; Lin, Ching-Long

2014-09-15

Lung air trapping is estimated via quantitative computed tomography (CT) using density threshold-based measures on an expiration scan. However, the effects of scanner differences and imaging protocol adherence on quantitative assessment are known to be problematic. This study investigates the effects of protocol differences, such as using different CT scanners and breath-hold coaches in a multicenter asthmatic study, and proposes new methods that can adjust intersite and intersubject variations. CT images of 50 healthy subjects and 42 nonsevere and 52 severe asthmatics at total lung capacity (TLC) and functional residual capacity (FRC) were acquired using three different scanners and two different coaching methods at three institutions. A fraction threshold-based approach based on the corrected Hounsfield unit of air with tracheal density was applied to quantify air trapping at FRC. The new air-trapping method was enhanced by adding a lung-shaped metric at TLC and the lobar ratio of air-volume change between TLC and FRC. The fraction-based air-trapping method is able to collapse air-trapping data of respective populations into distinct regression lines. Relative to a constant value-based clustering scheme, the slope-based clustering scheme shows the improved performance and reduced misclassification rate of healthy subjects. Furthermore, both lung shape and air-volume change are found to be discriminant variables for differentiating among three populations of healthy subjects and nonsevere and severe asthmatics. In conjunction with the lung shape and air-volume change, the fraction-based measure of air trapping enables differentiation of severe asthmatics from nonsevere asthmatics and nonsevere asthmatics from healthy subjects, critical for the development and evaluation of new therapeutic interventions. Copyright © 2014 the American Physiological Society.

Improved CT-based estimate of pulmonary gas trapping accounting for scanner and lung-volume variations in a multicenter asthmatic study

PubMed Central

Choi, Sanghun; Hoffman, Eric A.; Wenzel, Sally E.; Castro, Mario

2014-01-01

Lung air trapping is estimated via quantitative computed tomography (CT) using density threshold-based measures on an expiration scan. However, the effects of scanner differences and imaging protocol adherence on quantitative assessment are known to be problematic. This study investigates the effects of protocol differences, such as using different CT scanners and breath-hold coaches in a multicenter asthmatic study, and proposes new methods that can adjust intersite and intersubject variations. CT images of 50 healthy subjects and 42 nonsevere and 52 severe asthmatics at total lung capacity (TLC) and functional residual capacity (FRC) were acquired using three different scanners and two different coaching methods at three institutions. A fraction threshold-based approach based on the corrected Hounsfield unit of air with tracheal density was applied to quantify air trapping at FRC. The new air-trapping method was enhanced by adding a lung-shaped metric at TLC and the lobar ratio of air-volume change between TLC and FRC. The fraction-based air-trapping method is able to collapse air-trapping data of respective populations into distinct regression lines. Relative to a constant value-based clustering scheme, the slope-based clustering scheme shows the improved performance and reduced misclassification rate of healthy subjects. Furthermore, both lung shape and air-volume change are found to be discriminant variables for differentiating among three populations of healthy subjects and nonsevere and severe asthmatics. In conjunction with the lung shape and air-volume change, the fraction-based measure of air trapping enables differentiation of severe asthmatics from nonsevere asthmatics and nonsevere asthmatics from healthy subjects, critical for the development and evaluation of new therapeutic interventions. PMID:25103972

AutoGNI, the Robot Under the Aircraft Floor: An Automated System for Sampling Giant Aerosol Particles by Impaction in the Free Airstream Outside a Research Aircraft

NASA Astrophysics Data System (ADS)

Jensen, J. B.; Schwenz, K.; Aquino, J.; Carnes, J.; Webster, C.; Munnerlyn, J.; Wissman, T.; Lugger, T.

2017-12-01

Giant sea-salt aerosol particles, also called Giant Cloud Condensation Nuclei (GCCN), have been proposed as a means of rapidly forming precipitation sized drizzle drops in warm marine clouds (e.g., Jensen and Nugent, 2017). Such rare particles are best sampled from aircraft in air below cloud base, where normal laser optical instruments have too low sample volume to give statistically significant samples of the large particle tail. An automated sampling system (the AutoGNI) has been built to operate from inside a pressurized aircraft. Under the aircraft floor, a pressurized vessel contains 32 custom-built polycarbonate microscope slides. Using robotics with 5 motor drives and 18 positioning switches, the AutoGNI can take slides from their holding cassettes, pass them onto a caddy in an airfoil that extends 200 mm outside the aircraft, where they are exposed in the free airstream, thus avoiding the usual problems with large particle losses in air intakes. Slides are typically exposed for 10-30 s in the marine boundary layer, giving sample volumes of about 100-300 L or more. Subsequently the slides are retracted into the pressure vessel, stored and transported for laboratory microscope image analysis, in order to derive size-distribution histograms. While the aircraft is flying, the AutoGNI system is remotely controlled from a laptop on the ground, using an encrypted commercial satellite connection to the NSF/NCAR GV research aircraft's main server, and onto the AutoGNI microprocessor. The sampling of such GCCN is becoming increasingly important in order to provide complete input data for model calculations of aerosol-cloud interactions and their feedbacks in climate prediction. The AutoGNI has so far been sampling sea-salt GCCN in the Magellan Straight during the 2016 ORCAS project and over the NW Pacific during the 2017 ARISTO project, both from the NSF/NCAR GV research aircraft. Sea-salt particle sizes of 1.4 - 32 μm dry diameter have been observed.

Robust tissue-air volume segmentation of MR images based on the statistics of phase and magnitude: Its applications in the display of susceptibility-weighted imaging of the brain.

PubMed

Du, Yiping P; Jin, Zhaoyang

2009-10-01

To develop a robust algorithm for tissue-air segmentation in magnetic resonance imaging (MRI) using the statistics of phase and magnitude of the images. A multivariate measure based on the statistics of phase and magnitude was constructed for tissue-air volume segmentation. The standard deviation of first-order phase difference and the standard deviation of magnitude were calculated in a 3 x 3 x 3 kernel in the image domain. To improve differentiation accuracy, the uniformity of phase distribution in the kernel was also calculated and linear background phase introduced by field inhomogeneity was corrected. The effectiveness of the proposed volume segmentation technique was compared to a conventional approach that uses the magnitude data alone. The proposed algorithm was shown to be more effective and robust in volume segmentation in both synthetic phantom and susceptibility-weighted images of human brain. Using our proposed volume segmentation method, veins in the peripheral regions of the brain were well depicted in the minimum-intensity projection of the susceptibility-weighted images. Using the additional statistics of phase, tissue-air volume segmentation can be substantially improved compared to that using the statistics of magnitude data alone. (c) 2009 Wiley-Liss, Inc.

Automation Applications in an Advanced Air Traffic Management System : Volume 5A. DELTA Simulation Model - User's Guide

DOT National Transportation Integrated Search

1974-08-01

Volume 4 describes the automation requirements. A presentation of automation requirements is made for an advanced air traffic management system in terms of controller work for-e, computer resources, controller productivity, system manning, failure ef...

Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 2. System Functional Description and System Specification.

DOT National Transportation Integrated Search

1973-02-01

The volume provides a functional description and specification for the Satellite-Based Advanced Air Traffic Management System. The system description is presented in terms of the surveillance, navigation, and communications functions along with the a...

AIR QUALITY CRITERIA FOR PARTICULATE MATTER, VOLUMES I-III

EPA Science Inventory

There is no abstract available for these documents. If further information is requested, please refer to the bibliographic citation and contact the Technical Information Staff at the number listed below.

• Air Quality Criteria for Particulate Matter, Volume I - EP...

• Software for an experimental air-ground data link : volume 1. functional description and flowcharts.

  DOT National Transportation Integrated Search

  1975-10-01

  This report documents the complete software system developed for the Experimental Data Link System which was implementd for flight test during the Air-Ground Data Link Development Program. The software development is presented in three volumes as fol...

• Concept for a Satellite-Based Advanced Air Traffic Management System : Volume 4. Operational Description and Qualitative Assessment.

  DOT National Transportation Integrated Search

  1974-02-01

  The volume presents a description of how the Satellite-Based Advanced Air Traffic Management System (SAATMS) operates and a qualitative assessment of the system. The operational description includes the services, functions, and tasks performed by the...

• International system of units traceable results of Hg mass concentration at saturation in air from a newly developed measurement procedure.

  PubMed

  Quétel, Christophe R; Zampella, Mariavittoria; Brown, Richard J C; Ent, Hugo; Horvat, Milena; Paredes, Eduardo; Tunc, Murat

  2014-08-05

  Data most commonly used at present to calibrate measurements of mercury vapor concentrations in air come from a relationship known as the "Dumarey equation". It uses a fitting relationship to experimental results obtained nearly 30 years ago. The way these results relate to the international system of units (SI) is not known. This has caused difficulties for the specification and enforcement of limit values for mercury concentrations in air and in emissions to air as part of national or international legislation. Furthermore, there is a significant discrepancy (around 7% at room temperature) between the Dumarey data and data calculated from results of mercury vapor pressure measurements in the presence of only liquid mercury. As an attempt to solve some of these problems, a new measurement procedure is described for SI traceable results of gaseous Hg concentrations at saturation in milliliter samples of air. The aim was to propose a scheme as immune as possible to analytical biases. It was based on isotope dilution (ID) in the liquid phase with the (202)Hg enriched certified reference material ERM-AE640 and measurements of the mercury isotope ratios in ID blends, subsequent to a cold vapor generation step, by inductively coupled plasma mass spectrometry. The process developed involved a combination of interconnected valves and syringes operated by computer controlled pumps and ensured continuity under closed circuit conditions from the air sampling stage onward. Quantitative trapping of the gaseous mercury in the liquid phase was achieved with 11.5 μM KMnO4 in 2% HNO3. Mass concentrations at saturation found from five measurements under room temperature conditions were significantly higher (5.8% on average) than data calculated from the Dumarey equation, but in agreement (-1.2% lower on average) with data based on mercury vapor pressure measurement results. Relative expanded combined uncertainties were estimated following a model based approach. They ranged from 2.2% to 2.8% (k = 2). The volume of air samples was traceable to the kilogram via weighing of water for the calibration of the sampling syringe. Procedural blanks represented on average less than 0.1% of the mass of Hg present in 7.4 cm(3) of air, and correcting for these blanks was not an important source of uncertainty.

• Detection and volume estimation of embolic air in the middle cerebral artery using transcranial Doppler sonography.

  PubMed

  Bunegin, L; Wahl, D; Albin, M S

  1994-03-01

  Cerebral embolism has been implicated in the development of cognitive and neurological deficits following bypass surgery. This study proposes methodology for estimating cerebral air embolus volume using transcranial Doppler sonography. Transcranial Doppler audio signals of air bubbles in the middle cerebral artery obtained from in vivo experiments were subjected to a fast-Fourier transform analysis. Audio segments when no air was present as well as artifact resulting from electrocautery and sensor movement were also subjected to fast-Fourier transform analysis. Spectra were compared, and frequency and power differences were noted and used for development of audio band-pass filters for isolation of frequencies associated with air emboli. In a bench model of the middle cerebral artery circulation, repetitive injections of various air volumes between 0.5 and 500 microL were made. Transcranial Doppler audio output was band-pass filtered, acquired digitally, then subjected to a fast-Fourier transform power spectrum analysis and power spectrum integration. A linear least-squares correlation was performed on the data. Fast-Fourier transform analysis of audio segments indicated that frequencies between 250 and 500 Hz are consistently dominant in the spectrum when air emboli are present. Background frequencies appear to be below 240 Hz, and artifact resulting from sensor movement and electrocautery appears to be below 300 Hz. Data from the middle cerebral artery model filtered through a 307- to 450-Hz band-pass filter yielded a linear relation between emboli volume and the integrated value of the power spectrum near 40 microL. Detection of emboli less than 0.5 microL was inconsistent, and embolus volumes greater than 40 microL were indistinguishable from one another. The preliminary technique described in this study may represent a starting point from which automated detection and volume estimation of cerebral emboli might be approached.

• Evaluation and application of a passive air sampler for polycylic aromatic hydrocarbons (PAHs).

  PubMed

  Esen, Fatma; Evci, Yildiz M; Tasdemir, Yucel

  2017-08-24

  Sampling of 15 PAHs by the use of both passive air sampler developed (D-PAS) in our research group and PAS (C-PAS) having widespread use in the literature was conducted to compare the performances of the samplers. Sampling was carried out for 1-year period (February 2013-February 2014), in different sampling periods by employing D-PAS and C-PAS. D-PAS and C-PAS were run in parallel for 10, 20, 30, 40 and 60 days. Sampling rates were calculated for both PASs by the use of concentration values obtained from a high-volume air sampler (HVAS). It was determined that calculated sampling values are different from each other by definition of design of C-PAS and D-PAS and difference in environment as velocity of wind and temperature are having different effects upon sampling rates. Collected σ 15 PAHs amounts of 10-day periods in spring, summer, autumn and winter were obtained as 576 ± 333, 209 ± 29, 2402 ± 910 and 664 ± 246 ng for D-PAS and 1070 ± 522, 318 ± 292, 6062 ± 1501 and 6089 ± 4018 ng for C-PAS, respectively. In addition, according to seasons, when collected PAHs in two different samplers were considered, similar results were obtained for the summer time in which no combustion takes place with the aim of domestic heating, while there were differences determined for the seasons with combustion in need of domestic heating. Gas-phase σ 15 PAHs' concentrations were reported depending on seasons in the spring, summer, autumn and winter sequences as 46 ± 32, 9 ± 3, 367 ± 207 and 127 ± 93 ng m -3 for HVAS, respectively.

• Characterization and validation of sampling and analytical methods for mycotoxins in workplace air.

  PubMed

  Jargot, Danièle; Melin, Sandrine

  2013-03-01

  Mycotoxins are produced by certain plant or foodstuff moulds under growing, transport or storage conditions. They are toxic for humans and animals, some are carcinogenic. Methods to monitor occupational exposure to seven of the most frequently occurring airborne mycotoxins have been characterized and validated. Experimental aerosols have been generated from naturally contaminated particles for sampler evaluation. Air samples were collected on foam pads, using the CIP 10 personal aerosol sampler with its inhalable health-related aerosol fraction selector. The samples were subsequently solvent extracted from the sampling media, cleaned using immunoaffinity (IA) columns and analyzed by liquid chromatography with fluorescence detection. Ochratoxin A (OTA) or fumonisin and aflatoxin derivatives were detected and quantified. The quantification limits were 0.015 ng m(-3) OTA, 1 ng m(-3) fumonisins or 0.5 pg m(-3) aflatoxins, with a minimum dust concentration level of 1 mg m(-3) and a 4800 L air volume sampling. The methods were successfully applied to field measurements, which confirmed that workers could be exposed when handling contaminated materials. It was observed that airborne particles may be more contaminated than the bulk material itself. The validated methods have measuring ranges fully adapted to the concentrations found in the workplace. Their performance meets the general requirements laid down for chemical agent measurement procedures, with an expanded uncertainty less than 50% for most mycotoxins. The analytical uncertainty, comprised between 14 and 24%, was quite satisfactory given the low mycotoxin amounts, when compared to the food benchmarks. The methods are now user-friendly enough to be adopted for personal workplace sampling. They will later allow for mycotoxin occupational risk assessment, as only very few quantitative data have been available till now.

• The performance of the progressive resolution optimizer (PRO) for RapidArc planning in targets with low‐density media

  PubMed Central

  Leung, Lucullus H.T.; Yu, Peter K.N.

  2013-01-01

  A new version of progressive resolution optimizer (PRO) with an option of air cavity correction has been implemented for RapidArc volumetric‐modulated arc therapy (RA). The purpose of this study was to compare the performance of this new PRO with the use of air cavity correction option (PRO10_air) against the one without the use of the air cavity correction option (PRO10_no‐air) for RapidArc planning in targets with low‐density media of different sizes and complexities. The performance of PRO10_no‐air and PRO10_air was initially compared using single‐arc plans created for four different simple heterogeneous phantoms with virtual targets and organs at risk. Multiple‐arc planning of 12 real patients having nasopharyngeal carcinomas (NPC) and ten patients having non‐small cell lung cancer (NSCLC) were then performed using the above two options for further comparison. Dose calculations were performed using both the Acuros XB (AXB) algorithm with the dose to medium option and the analytical anisotropic algorithm (AAA). The effect of using intermediate dose option after the first optimization cycle in PRO10_air and PRO10_no‐air was also investigated and compared. Plans were evaluated and compared using target dose coverage, critical organ sparing, conformity index, and dose homogeneity index. For NSCLC cases or cases for which large volumes of low‐density media were present in or adjacent to the target volume, the use of the air cavity correction option in PROIO was shown to be beneficial. For NPC cases or cases for which small volumes of both low‐ and high‐density media existed in the target volume, the use of air cavity correction in PRO10 did not improve the plan quality. Based on the AXB dose calculation results, the use of PRO10_air could produce up to 18% less coverage to the bony structures of the planning target volumes for NPC cases. When the intermediate dose option in PRO10 was used, there was negligible difference observed in plan quality between optimizations with and without using the air cavity correction option. PACS number: 87.55.D‐, 87.55.de, 87.56.N‐

• Single Particle Analysis by Combined Chemical Imaging to Study Episodic Air Pollution Events in Vienna

  NASA Astrophysics Data System (ADS)

  Ofner, Johannes; Eitenberger, Elisabeth; Friedbacher, Gernot; Brenner, Florian; Hutter, Herbert; Schauer, Gerhard; Kistler, Magdalena; Greilinger, Marion; Lohninger, Hans; Lendl, Bernhard; Kasper-Giebl, Anne

  2017-04-01

  The aerosol composition of a city like Vienna is characterized by a complex interaction of local emissions and atmospheric input on a regional and continental scale. The identification of major aerosol constituents for basic source appointment and air quality issues needs a high analytical effort. Exceptional episodic air pollution events strongly change the typical aerosol composition of a city like Vienna on a time-scale of few hours to several days. Analyzing the chemistry of particulate matter from these events is often hampered by the sampling time and related sample amount necessary to apply the full range of bulk analytical methods needed for chemical characterization. Additionally, morphological and single particle features are hardly accessible. Chemical Imaging evolved to a powerful tool for image-based chemical analysis of complex samples. As a complementary technique to bulk analytical methods, chemical imaging can address a new access to study air pollution events by obtaining major aerosol constituents with single particle features at high temporal resolutions and small sample volumes. The analysis of the chemical imaging datasets is assisted by multivariate statistics with the benefit of image-based chemical structure determination for direct aerosol source appointment. A novel approach in chemical imaging is combined chemical imaging or so-called multisensor hyperspectral imaging, involving elemental imaging (electron microscopy-based energy dispersive X-ray imaging), vibrational imaging (Raman micro-spectroscopy) and mass spectrometric imaging (Time-of-Flight Secondary Ion Mass Spectrometry) with subsequent combined multivariate analytics. Combined chemical imaging of precipitated aerosol particles will be demonstrated by the following examples of air pollution events in Vienna: Exceptional episodic events like the transformation of Saharan dust by the impact of the city of Vienna will be discussed and compared to samples obtained at a high alpine background site (Sonnblick Observatory, Saharan Dust Event from April 2016). Further, chemical imaging of biological aerosol constituents of an autumnal pollen breakout in Vienna, with background samples from nearby locations from November 2016 will demonstrate the advantages of the chemical imaging approach. Additionally, the chemical fingerprint of an exceptional air pollution event from a local emission source, caused by the pull down process of a building in Vienna will unravel the needs for multisensor imaging, especially the combinational access. Obtained chemical images will be correlated to bulk analytical results. Benefits of the overall methodical access by combining bulk analytics and combined chemical imaging of exceptional episodic air pollution events will be discussed.

• Particle impactor assembly for size selective high volume air sampler

  DOEpatents

  Langer, Gerhard

  1988-08-16

  Air containing entrained particulate matter is directed through a plurality of parallel, narrow, vertically oriented impactor slots of an inlet element toward an adjacently located, relatively large, dust impaction surface preferably covered with an adhesive material. The air flow turns over the impaction surface, leaving behind the relatively larger particles according to the human thoracic separation system and passes through two elongate exhaust apertures defining the outer bounds of the impaction collection surface to pass through divergent passages which slow down and distribute the air flow, with entrained smaller particles, over a fine filter element that separates the fine particles from the air. The elongate exhaust apertures defining the impaction collection surface are spaced apart by a distance greater than the lengths of elongate impactor slots in the inlet element and are oriented to be normal thereto. By appropriate selection of dimensions and the number of impactor slots air flow through the inlet element is provided a nonuniform velocity distribution with the lower velocities being obtained near the center of the impactor slots, in order to separate out particles larger than a certain predetermined size on the impaction collection surface. The impaction collection surface, even in a moderately sized apparatus, is thus relatively large and permits the prolonged sampling of air for periods extending to four weeks.

• Atmospheric PCB congeners across Chicago

  NASA Astrophysics Data System (ADS)

  Hu, Dingfei; Lehmler, Hans-Joachim; Martinez, Andres; Wang, Kai; Hornbuckle, Keri C.

  2010-04-01

  We have measured PCBs in 184 air samples collected at 37 sites in the city of Chicago using an innovative system of high-volume air samplers mounted on two health clinic vans. Here we describe results of sampling conducted from November 2006 to November 2007. The samples were analyzed for all 209 PCB congeners using a gas chromatograph with tandem mass spectrometry (GC-MS/MS). The ΣPCBs (sum of 169 peaks) in Chicago ranged from 75 pg m -3 to 5500 pg m -3 and primarily varied as a function of temperature. The congener patterns are surprisingly similar throughout the city even though the temperature-corrected concentrations vary by more than an order of magnitude. The average profile resembles a mixture of Aroclor 1242 and Aroclor 1254, and includes many congeners that have been identified as being aryl hydrocarbon receptor (AhR) agonists (dioxin-like) and/or neurotoxins. The toxic equivalence (TEQ) and neurotoxic equivalence (NEQ) in air were calculated and investigated for their spatial distribution throughout the urban-industrial complex of Chicago. The NEQ concentrations are linearly correlated with ΣPCBs while the TEQ concentrations are not predictable. The findings of this study suggest that airborne PCBs in Chicago are widely present and elevated in residential communities; there are multiple sources rather than one or a few locations of very high emissions; the emission includes congeners associated with dioxin-like or neurotoxic effects and congeners associated with unidentified sources.

• FAA Air Traffic Control Operations Concepts. Volume 7. ATCT (Airport Traffic Control Towers) Tower Controllers

  DTIC Science & Technology

  1989-04-21

  kift rIn FAA AIR TRAFFIC CONTROL OPERATIONS CONCEPTS V olum e V iI:.................... ATCT Tower Controllers AmELECTE JUL 2 11989 21 April 1989 A...01 022.3013209-87-B 11 a FAA AIR TRAFFIC CONTROL OPERATIONS CONCEPTS VOLUME VII: ATCT TOWER CONTROLLERS CDRL Bl 12, VOL. VII CONTRACT DTF-AO1-85-Y...INCORPORATED 7150 Campus Drive, Suite 100 Colorado Springs, CO 80920 (719) 590-5100 DOT/FAA/AP-87-0i (VOL#7) 21 April 1989 FAA AIR TRAFFIC CONTROL OPERATIONS

• Cost Model/Data Base Catalog Non-DoD/Academic Survey. Volume 1. Project Summary

  DTIC Science & Technology

  1988-10-30

  presented in two volumes: Volume 1- Project Summary, and L .JD Volume 2- Final Data Base. J Accesion - For NTIS C R A& Disiji( .. . U, L)~ .6I...218 47I I I I I I I I Exhibit 111-3. COMPLETE CATALOG BREAKOUT I MANAGEMENT CONSULTING & RESEARCH, INC. j 111-6 I IE-I Iu 0 HE-4 X C.) E- Ix UI.n 111...College/EDCCAir University Maxwell Air Force Base, AL 36112 2. AD (Armament Division) Department of the Air Force Armament Division/(subdiv code

• Resonant photoacoustic detection of NO2 traces with a Q-switched green laser

  NASA Astrophysics Data System (ADS)

  Slezak, Verónica; Codnia, Jorge; Peuriot, Alejandro L.; Santiago, Guillermo

  2003-01-01

  Resonant photoacoustic detection of NO2 traces by means of a high repetition pulsed green laser is presented. The resonator is a cylindrical Pyrex glass cell with a measured Q factor 380 for the first radial mode in air at atmospheric pressure. The system is calibrated with known mixtures in dry air and a minimum detectable volume concentration of 50 parts in 109 is obtained (S/N=1). Its sensitivity allows one to detect and quantify NO2 traces in the exhaust gases of cars. Previously, the analysis of gas adsorption and desorption on the walls and of changes in the sample composition is carried out in order to minimize errors in the determination of NO2 content upon application of the extractive method. The efficiency of catalytic converters of several models of automobiles is studied and the NO2 concentration in samples from exhausts of different types of engine (gasoline, diesel, and methane gas) at idling operation are measured.

Simple, miniaturized blood plasma extraction method.

PubMed

Kim, Jin-Hee; Woenker, Timothy; Adamec, Jiri; Regnier, Fred E

2013-12-03

A rapid plasma extraction technology that collects a 2.5 μL aliquot of plasma within three minutes from a finger-stick derived drop of blood was evaluated. The utility of the plasma extraction cards used was that a paper collection disc bearing plasma was produced that could be air-dried in fifteen minutes and placed in a mailing envelop for transport to an analytical laboratory. This circumvents the need for venipuncture and blood collection in specialized vials by a phlebotomist along with centrifugation and refrigerated storage. Plasma extraction was achieved by applying a blood drop to a membrane stack through which plasma was drawn by capillary action. During the course of plasma migration to a collection disc at the bottom of the membrane stack blood cells were removed by a combination of adsorption and filtration. After the collection disc filled with an aliquot of plasma the upper membranes were stripped from the collection card and the collection disc was air-dried. Intercard differences in the volume of plasma collected varied approximately 1% while volume variations of less than 2% were seen with hematocrit levels ranging from 20% to 71%. Dried samples bearing metabolites and proteins were then extracted from the disc and analyzed. 25-Hydroxy vitamin D was quantified by LC-MS/MS analysis following derivatization with a secosteroid signal enhancing tag that imparted a permanent positive charge to the vitamin and reduced the limit of quantification (LOQ) to 1 pg of collected vitamin on the disc; comparable to values observed with liquid-liquid extraction (LLE) of a venipuncture sample. A similar study using conventional proteomics methods and spectral counting for quantification was conducted with yeast enolase added to serum as an internal standard. The LOQ with extracted serum samples for enolase was 1 μM, linear from 1 to 40 μM, the highest concentration examined. In all respects protein quantification with extracted serum samples was comparable to that observed with serum samples obtained by venipuncture.

Graph-cut Based Interactive Segmentation of 3D Materials-Science Images

DTIC Science & Technology

2014-04-26

which is available to authorized users. J . Waggoner · Y. Zhou · S. Wang (B) University of South Carolina, Columbia, USA e-mail: songwang@cec.sc.edu... J . Waggoner e-mail: waggonej@email.sc.edu J . Simmons Materials and Manufacturing Directorate, Air Force Research Labs, Dayton, USA M. De Graef...sample slices 123 Author’s personal copy J . Waggoner et al. Fig. 1 Two adjacent slices of a titanium image volume [40]. Image intensity inverted for

Proceedings of the 1980 Tri-Service Conference on Corrosion, 5-7 November 1980, US Air Force Academy, Colorado. Volume 2

DTIC Science & Technology

1980-11-01

the potential fiield vacialions at a plane parallel to the sample surface. The signals can also be recorded on a storage oscilloscope and photographed... storage , and overhaul is performed at the J jappropriate depot(s). If a program requires intensive management, a project manager is dcsignated and...the program include the conduct of a Triennial inspection of DARCOM facilities, thc establishment of a Materiel Deterioration Information Certer, the

Preliminary Assessment/Site Investigation: Tooele Army Depot, Utah. Volume 1. North Area and Facilities at Hill Air Force Base

DTIC Science & Technology

1988-12-12

groundwater , and/or surface water to determine existance af contamination, if any, and to evaluate potential for offsite migration; and (5) identify off... water source, was found to be contaminated with explosives. A shallow perched groundwater zone, created by effluent sdepage through the base was also...Evidence of groundwater contamination from past activities at the OB/OD Grounds was not indicated as a result of sampling and analysis of two water

Installation Restoration Program. Phase 2. Confirmation/Quantification Stage 2, Moody Air Force Base, Georgia. Appendices. Volume 1

DTIC Science & Technology

1988-11-01

Light gray NB, clayey (kaolin). Poetv al - quartz mad to fine sand, mod. (0 Locking Cap plastic , saturated. 3 COMPILED BY B. Painter (EWM) t DATE 11-21...Painter (EUM) -SAMPLE PNTAINSOIL DESCRIIPTION COMMENTS ZTEST NAME. GRADATION OR PLASTICITY ,. DEPTH Of CASING, W ~ 1NPARTICLE SIZE DISTRIBUTION. COLOR...L. Grayish orange 10 YR 7/4. quart. RNDEVAI: very tine Sandy clay, dense, DIAMETER: 2-inrh Srhe So PVC moderately plastics dry. DEPTH: 2 - fenot[ 1

Double window viewing chamber assembly

NASA Technical Reports Server (NTRS)

Keller, V. W. (Inventor); Owen, R. B. (Inventor); Elkins, B. R. (Inventor); White, W. T. (Inventor)

1986-01-01

A viewing chamber which permits observation of a sample retained therein includes a pair of double window assemblies mounted in opposed openings in the walls thereof so that a light beam can directly enter and exit from the chamber. A flexible mounting arrangement for the outer windows of the window assemblies enables the windows to be brought into proper alignment. An electrical heating arrangement prevents fogging of the outer windows whereas desiccated air in the volume between the outer and inner windows prevents fogging of the latter.

Wyoming Low-Volume Roads Traffic Volume Estimation

DOT National Transportation Integrated Search

2015-10-01

Low-volume roads are excluded from regular traffic counts except on a need to know basis. But needs for traffic volume data on low-volume roads in road infrastructure management, safety, and air quality analysis have necessitated regular traffic volu...

Spray distribution evaluation of different settings of a hand-held-trolley sprayer used in greenhouse tomato crops.

PubMed

Llop, Jordi; Gil, Emilio; Gallart, Montserrat; Contador, Felipe; Ercilla, Mireia

2016-03-01

Hand-held-trolley sprayers have recently been promoted to improve spray application techniques in greenhouses in south-eastern Spain. However, certain aspects remain to be improved. A modified hand-held-trolley sprayer was evaluated under two different canopy conditions (high and low canopy density) and with several sprayer settings (nozzle type, air assistance and spray volume). In this study, the deposition, coverage and uniformity of distribution of the spray on the canopy have been assessed. The deposition on leaves was significantly higher when flat-fan nozzles and air assistance were used at both high and low spray volumes. No differences were detected between the reference system at a high spray volume and the modified trolley at a low spray volume. Flat-fan nozzles with air assistance increased penetrability into the canopy. Air assistance and flat-fan nozzles allow volume rates to be reduced while maintaining or improving spray quality distribution. The working parameters of hand-held sprayers must be considered to reduce environmental risk and increase the efficacy of the spraying process. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Air Force Civil Engineer, Volume 12, Number 2, 2004

DTIC Science & Technology

2004-01-01

Volume 12 • No. 2 • 2004 CIVIL ENGINEERAir Force Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection...Section: USAF Facility Energy Management Program. (Air Force Civil Engineer, Volume 12 , Number 02, 2004) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c...AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12 . DISTRIBUTION/AVAILABILITY STATEMENT

Air Force Civil Engineer, Volume 12, Number 1, 2004

DTIC Science & Technology

2004-01-01

Building the ARRK Volume 12 • No. 1 • 2004 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of...Air Force Civil Engineer, Volume 12 , Number 01, 2004) 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT...MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12 . DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release; distribution

Comparison between Hydrogen, Methane and Ethylene Fuels in a 3-D Scramjet at Mach 8

DTIC Science & Technology

2016-06-24

characteristics in air. The disadvantage of hydrogen is its low density, which is a particular problem for small vehicles with significant internal...characteristics in air. The disadvantage of hydrogen is its low density, which is a particular problem for small vehicles with significant internal volume...The low energy per unit volume of gaseous hydrogen, however, is a significant problem for small vehicles with internal volume constraints, in addition

Effect of air temperature and relative humidity at various fuel-air ratios on exhaust emissions on a per-mode basis of an Avco Lycoming 0-320 DIAD light aircraft engine. Volume 2: Individual data points

NASA Technical Reports Server (NTRS)

Skorobatckyi, M.; Cosgrove, D. V.; Meng, P. R.; Kempke, E. R.

1976-01-01

A carbureted four cylinder air cooled 0-320 DIAD Lycoming aircraft engine was tested to establish the effects of air temperature and humidity at various fuel-air ratios on the exhaust emissions on a per-mode basis. The test conditions included carburetor lean-out at air temperatures of 50, 59, 80, and 100 F at relative humidities of 0, 30, 60, and 80 percent. Temperature-humidity effects at the higher values of air temperature and relative humidity tested indicated that the HC and CO emissions increased significantly, while the NOx emissions decreased. Even at a fixed fuel-air ratio, the HC emissions increase and the NOx emissions decrease at the higher values of air temperature and humidity. Volume II contains the data taken at each of the individual test points.

Method and apparatus for sampling low-yield wells

DOEpatents

Last, George V.; Lanigan, David C.

2003-04-15

An apparatus and method for collecting a sample from a low-yield well or perched aquifer includes a pump and a controller responsive to water level sensors for filling a sample reservoir. The controller activates the pump to fill the reservoir when the water level in the well reaches a high level as indicated by the sensor. The controller deactivates the pump when the water level reaches a lower level as indicated by the sensors. The pump continuously activates and deactivates the pump until the sample reservoir is filled with a desired volume, as indicated by a reservoir sensor. At the beginning of each activation cycle, the controller optionally can select to purge an initial quantity of water prior to filling the sample reservoir. The reservoir can be substantially devoid of air and the pump is a low volumetric flow rate pump. Both the pump and the reservoir can be located either inside or outside the well.

Indoor air pollutants from unvented kerosene-heater emissions in mobile homes: Studies on particles, semivolatile organics, carbon monoxide, and mutagenicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mumford, J.L.; Williams, R.W.; Walsh, D.B.

1991-01-01

The study was conducted to assess human exposure to air pollutants resulting from the use of kerosene heaters in mobile homes. It has been estimated that 15-17 million unvented kerosene heaters have been sold in the United States, and 33% of these heaters have been sold to mobile home residents. The emissions from kerosene heaters can result in high pollutants levels in mobile homes that have a small air volume and low ventilation rate. Eight totally electric mobile homes with no smokers living in the homes were monitored for indoor air particles < 10 micrometer (PM10), semivolatile organics, carbon monoxidemore » (CO), and mutagenicity of semivolatile and particle-phase organics in Salmonella typhimurium TA98 without S9 using a microsuspension reverse-mutation assay. Each home was monitored for an average of 6.5 h/day, 3 days/week, for 4 weeks (2 weeks with the heater on and 2 weeks with the heater off) during the heating season of 1989. Indoor air exchange rate, temperature, and humidity were measured. Chemical analyses, including polycyclic aromatic hydrocarbon (PAH) and nitro PAH, also were performed on the indoor air samples from a selected home with the kerosene heater on and off. Increases in CO and organic concentrations resulting from the use of kerosene heaters were found in most homes monitored. Chemical analysis data also suggested the presence of evaporated, unburned kerosene fuel present in semivolatile organics collected in the XAD samples. In comparison with the U.S. national ambient air standards, four out of the eight heaters investigated in the study emitted pollutants that exceeded the ambient air standards some days. These data suggested that emissions from unvented kerosene heaters can significantly impact indoor air quality in mobile homes and that these emissions contain carcinogenic compounds and can be potentially carcinogenic in humans.« less

Methods of sampling airborne fungi in working environments of waste treatment facilities.

PubMed

Černá, Kristýna; Wittlingerová, Zdeňka; Zimová, Magdaléna; Janovský, Zdeněk

2016-01-01

The objective of the present study was to evaluate and compare the efficiency of a filter based sampling method and a high volume sampling method for sampling airborne culturable fungi present in waste sorting facilities. Membrane filters method was compared with surface air system method. The selected sampling methods were modified and tested in 2 plastic waste sorting facilities. The total number of colony-forming units (CFU)/m3 of airborne fungi was dependent on the type of sampling device, on the time of sampling, which was carried out every hour from the beginning of the work shift, and on the type of cultivation medium (p < 0.001). Detected concentrations of airborne fungi ranged 2×102-1.7×106 CFU/m3 when using the membrane filters (MF) method, and 3×102-6.4×104 CFU/m3 when using the surface air system (SAS) method. Both methods showed comparable sensitivity to the fluctuations of the concentrations of airborne fungi during the work shifts. The SAS method is adequate for a fast indicative determination of concentration of airborne fungi. The MF method is suitable for thorough assessment of working environment contamination by airborne fungi. Therefore we recommend the MF method for the implementation of a uniform standard methodology of airborne fungi sampling in working environments of waste treatment facilities. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.

40 CFR 63.461 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... solvent/air interface, the maximum volume of parts that can be cleaned at one time. In most cases, the cleaning capacity is equal to the volume (length times width times height) of the cleaning chamber. Cold... designed to be easily opened and closed without disturbing the vapor zone. Air disturbances include, but...

Air Pollution Translations: A Bibliography with Abstracts - Volume 2.

ERIC Educational Resources Information Center

National Air Pollution Control Administration (DHEW), Raleigh, NC.

This volume is the second in a series of compilations presenting abstracts and indexes of translations of technical air pollution literature. The 444 entries are grouped into 12 subject categories: General; Emission Sources; Atmospheric Interaction; Measurement Methods; Control Methods; Effects--Human Health; Effects--Plants and Livestock;…

INTEGRATED AIR POLLUTION CONTROL SYSTEM VERSION 5.0 - VOLUME 2: TECHNICAL DOCUMENTATION

EPA Science Inventory

The three volume report and two diskettes document the Integrated Air Pollution Control System (IAPCS), developed for the U.S. EPA to estimate costs and performance for emission control systems applied to coal-fired utility boilers. The model can project a material balance, an eq...

INTEGRATED AIR POLLUTION CONTROL SYSTEM VERSION 5.0 - VOLUME 3: PROGRAMMER'S MAINTENANCE MANUAL

EPA Science Inventory

The three volume report and two diskettes document the Integrated Air Pollution Control System (IAPCS), developed for the U.S. EPA to estimate costs and performance for emission control systems applied to coal-fired utility boilers. The model can project a material balance, an eq...

INTEGRATED AIR POLLUTION CONTROL SYSTEM VERSION 5.0 - VOLUME 1: USER'S GUIDE

EPA Science Inventory

The three volume report and two diskettes document the Integrated Air Pollution Control System (IAPCS), developed for the U.S. EPA to estimate costs and performance for emission control systems applied to coal-fired utility boilers. The model can project a material balance, an eq...

Air Pollution. Part A: Analysis.

ERIC Educational Resources Information Center

Ledbetter, Joe O.

Two facets of the engineering control of air pollution (the analysis of possible problems and the application of effective controls) are covered in this two-volume text. Part A covers Analysis, and Part B, Prevention and Control. (This review is concerned with Part A only.) This volume deals with the terminology, methodology, and symptomatology…

40 CFR 86.1823-08 - Durability demonstration procedures for exhaust emissions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... § 86.1801. Eligible small volume manufacturers or small volume test groups may optionally meet the...

40 CFR 86.1823-08 - Durability demonstration procedures for exhaust emissions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES (CONTINUED) General Compliance Provisions for Control of Air Pollution From New and In... § 86.1801. Eligible small volume manufacturers or small volume test groups may optionally meet the...

AIR QUALITY CRITERIA FOR PARTICULATE MATTER, VOLUMES I-III, (EXTERNAL REVIEW DRAFT, 1995)

EPA Science Inventory

There is no abstract available for these documents.

If further information is requested, please refer to the bibliographic citation and contact the Technical Information Staff at the number listed above.

• Air Quality Criteria for Particulate Matter, Volume I, Extern...

• Synthesis, structural and electrical studies of Ba1-xSrxCe0.65Zr0.25Pr0.1O3-δ electrolyte materials for solid oxide fuel cells

  NASA Astrophysics Data System (ADS)

  Madhuri Sailaja, J.; Murali, N.; Margarette, S. J.; Mammo, Tulu Wegayehu; Veeraiah, V.

  2018-03-01

  This paper is discussed Sr doping effect on the microstructure, chemical stability and conductivity of Ba1-xSrxCe0.65Zr0.25Pr0.1O3-δ (0 ≤ x ≤ 0.2) electrolyte prepared by sol-gel method. The lattice constants and unit cell volumes are found to decrease as Sr atomic percentage increased in accordance with the Vegard law, confirming the formation of solid solution with orthorhombic structure. Among them all the synthesized samples are showed a conductivity with different atmosphere values at 500 °C. Ba0.92Sr0.08Ce0.65Zr0.25Pr0.1O3-δ recorded highest conductivity with a value of 3.3 × 10-6 S/cm (dry air) & 3.41 × 10-6 S/cm (wet air with 3% relative humidity) at 500 °C due to its smaller lattice volume, larger grain size and lower activation energy that led to excessive increase in conductivity. All pellets exhibited good chemical stability when exposed to air and H2O atmospheres. This study elucidates that the composition will be a promising electrolyte material for use as SOFC at intermediate temperatures if Sr doping is limited to small amounts.

• Size and Velocity Characteristics of Droplets Generated by Thin Steel Slab Continuous Casting Secondary Cooling Air-Mist Nozzles

  NASA Astrophysics Data System (ADS)

  Minchaca M, J. I.; Castillejos E, A. H.; Acosta G, F. A.

  2011-06-01

  Direct spray impingement of high temperature surfaces, 1473 K to 973 K (1200 °C to 700 °C), plays a critical role in the secondary cooling of continuously cast thin steel slabs. It is known that the spray parameters affecting the local heat flux are the water impact flux w as well as the droplet velocity and size. However, few works have been done to characterize the last two parameters in the case of dense mists ( i.e., mists with w in the range of 2 to 90 L/m2s). This makes it difficult to rationalize how the nozzle type and its operating conditions must be selected to control the cooling process. In the present study, particle/droplet image analysis was used to determine the droplet size and velocity distributions simultaneously at various locations along the major axis of the mist cross section at a distance where the steel strand would stand. The measurements were carried out at room temperature for two standard commercial air-assisted nozzles of fan-discharge type operating over a broad range of conditions of practical interest. To achieve statistically meaningful samples, at least 6000 drops were analyzed at each location. Measuring the droplet size revealed that the number and volume frequency distributions were fitted satisfactorily by the respective log-normal and Nukiyama-Tanasawa distributions. The correlation of the parameters of the distribution functions with the water- and air-nozzle pressures allowed for reasonable estimation of the mean values of the size of the droplets generated. The ensemble of measurements across the mist axis showed that the relationship between the droplet velocity and the diameter exhibited a weak positive correlation. Additionally, increasing the water flow rate at constant air pressure caused a decrease in the proportion of the water volume made of finer droplets, whereas the volume proportion of faster droplets augmented until the water flow reached a certain value, after which it decreased. Diminishing the air-to-water flow rates ratio, particularly below 10, resulted in mists of bigger and slower droplets with low impinging Weber numbers. However, increasing the air pressure maintaining a constant water flow rate caused a greater proportion of finer and faster drops with Weber numbers greater than 80, which suggests an increased probability of wet drop contact with a hot surface that would intensify heat extraction.

• Characterization of Dust on Solar Devices in Southern Nevada =

  NASA Astrophysics Data System (ADS)

  Sylva, Jason R.

  Dust can impact the efficiency of solar energy collection devices, and in some arid environments, dust can reduce solar energy efficiency up to 30%. Reducing the impact of dust is therefore critical in the expansion of solar technology throughout regions where solar energy is utilized. Characterization of suspended and settled particulate matter can assist in developing strategies for dust mitigation. With the characterization of suspended and settled particulate in remote, rural, and urban environments, more informed decisions can be made regarding the selection of coating material on solar panels as well as developing cleaning and maintenance procedures. Particulate matter that deposits on a solar surface can potentially interact with solar radiation, precipitation, or even directly with the surface material itself. These interactions could lead to the formation of coatings that reduce/block radiation and/or degrade the integrity of the surface. When you extrapolate these possibilities to a larger scale preliminary characterization of dust will play a vital role when planning the construction of a solar energy facility. A variety of sampling techniques were employed to obtain particulate matter for characterization. These included direct collection of particulates from solar surfaces: via vacuum and wipe sample collection on panels, tacky dot adhesive slides and plain slides that were exposed at different intervals, desert vugs that are natural particulate collectors, as well as high volume air sampling for collection of suspended particulates. High volume air sampling was performed using glass fiber filters and 2 micron stainless steel screens. Direct collection of settled particulates was performed by sampling from solar surfaces, vugs, and by collection on exposed glass surfaces. Collection onto glass surfaces was achieved by setting up a plain microscope slide, tacky dot slides, and panes of glass. The sampling methodology allowed for the collection of samples for analyses using various analytical methods that included Raman microspectroscopy, pyrolysis gas chromatography mass spectrometry, ion chromatography and inductively coupled plasma mass spectrometry. These various methods allow for identification of organic and inorganic components as well the mineral distribution of suspended and settled particulate material. None None None None None

• SpaceX Dragon Air Circulation System

  NASA Technical Reports Server (NTRS)

  Hernandez, Brenda; Piatrovich, Siarhei; Prina, Mauro

  2011-01-01

  The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

• Velocity and temperature field characteristics of water and air during natural convection heating in cans.

  PubMed

  Erdogdu, Ferruh; Tutar, Mustafa

  2011-01-01

  Presence of headspace during canning is required since an adequate amount allows forming vacuum during the process. Sealing technology may not totally eliminate all entrapped gases, and headspace might affect heat transfer. Not much attention has been given to solve this problem in computational studies, and cans, for example, were mostly assumed to be fully filled with product. Therefore, the objective of this study was to determine velocity and temperature evolution of water and air in cans during heating to evaluate the relevance of headspace in the transport mechanism. For this purpose, canned water samples with a certain headspace were used, and required governing continuity, energy, and momentum equations were solved using a finite volume approach coupled with a volume of fluid element model. Simulation results correlated well with experimental results validating faster heating effects of headspace rather than insulation effects as reported in the literature. The organized velocity motions along the air-water interface were also shown. Practical Application: Canning is a universal and economic method for processing of food products, and presence of adequate headspace is required to form vacuum during sealing of the cans. Since sealing technology may not totally eliminate the entrapped gases, mainly air, headspace might affect heating rates in cans. This study demonstrated the increased heating rates in the presence of headspace in contrast with some studies in the literature. By applying the effect of headspace, required processing time for thermally processed foods can be reduced leading to more rapid processes and lower energy consumptions.

• Average rainwater pH, concepts of atmospheric acidity, and buffering in open systems

  NASA Astrophysics Data System (ADS)

  Liljestrand, Howard M.

  The system of water equilibrated with a constant partial pressure of CO 2, as a reference point for pH acidity-alkalinity relationships, has nonvolatile acidity and alkalinity components as conservative quantities, but not [H +]. Simple algorithms are presented for the determination of the average pH for combinations of samples both above and below pH 5.6. Averaging the nonconservative quantity [H +] yields erroneously low mean pH values. To extend the open CO 2 system to include other volatile atmospheric acids and bases distributed among the gas, liquid and particulate matter phases, a theoretical framework for atmospheric acidity is presented. Within certain oxidation-reduction limitations, the total atmospheric acidity (but not free acidity) is a conservative quantity. The concept of atmospheric acidity is applied to air-water systems approximating aerosols, fogwater, cloudwater and rainwater. The buffer intensity in hydrometeors is described as a function of net strong acidity, partial pressures of acid and base gases and the water to air ratio. For high liquid to air volume ratios, the equilibrium partial pressures of trace acid and base gases are set by the pH or net acidity controlled by the nonvolatile acid and base concentrations. For low water to air volume ratios as well as stationary state systems such as precipitation scavenging with continuous emissions, the partial pressures of trace gases (NH 3, HCl, HNO 3, SO 2 and CH 3COOH) appear to be of greater or equal importance as carbonate species as buffers in the aqueous phase.

• Wind measurement system

  NASA Technical Reports Server (NTRS)

  Cliff, W. C.; Huffaker, R. M.; Dahm, W. K.; Thomson, J. A. L.; Lawrence, T. R.; Krause, M. C.; Wilson, D. J. (Inventor)

  1976-01-01

  A system for remotely measuring vertical and horizontal winds present in discrete volumes of air at selected locations above the ground is described. A laser beam is optically focused in range by a telescope, and the output beam is conically scanned at an angle about a vertical axis. The backscatter, or reflected light, from the ambient particulates in a volume of air, the focal volume, is detected for shifts in wavelength, and from these, horizontal and vertical wind components are computed.

• A proposed rationale and test methodology for establishment of acceptance criteria for vacuum integrity testing of pharmaceutical freeze dryers.

  PubMed

  Hardwick, Lisa M; Nail, Steven L; Jarman, James; Hasler, Kai; Hense, Thomas

  2013-10-01

  A scientific rationale is proposed for the establishment of acceptance criteria for leak rates in pharmaceutical freeze dryers. A method was developed to determine the quantity of air that could leak into any lyophilizer from the outside while still maintaining Class 100/Grade A microbial conditions. A lyophilizing product is assumed most vulnerable to microbial contamination during secondary drying, when mass transfer of water vapor from product to condenser is minimal. Using the void volume of the dryer, calculated from change in internal pressure when a known volume of air is introduced, and the potential maximum bioburden of the leaked air (based on measured values), calculations can determine the allowable leaked volume of air, the flow rate required to admit that volume in a given time frame, and the pressure rise that would result from the leak over a given testing period. For the dryers in this study, using worst-case air quality conditions, it was determined that a leak resulting in a pressure rise of 0.027 mbar over a 30 min period would allow the dryers to remain in secondary drying conditions for 62 h before the established action level of one colony forming unit for each cubic meter of air space would be reached. Copyright © 2013 Elsevier B.V. All rights reserved.

• Tritium and 14C concentrations in unsaturated-zone gases at test hole UZB-2, Amargosa Desert Research Site, 1994-98: A section in U.S. Geological Survey Toxic Substances Hydrology Program: Proceedings of the technical meeting, Charleston, South Carolina, March 8-12, 1999: Volume 3 (Part C) (WRI 99-4018C)>

  USGS Publications Warehouse

  Prudic, David E.; Striegl, Robert G.; Healy, Richard W.; Michel, Robert L.; Haas, Herbert; Morganwalp, David W.; Buxton, Herbert T.

  1999-01-01

  Tritium concentrations have been determined yearly since April 1994 from water-vapor samples collected at test hole UZB-2. The hole was drilled about 100 m (meters) south of the southwest corner of a commercial burial site for low-level radioactive wastes in September 1993. UZB-2 is equipped with ten 2.5-cm (centimeters) diameter air ports permanently installed in the unsaturated zone between the depths of 5.5 and 108.8 m below land surface. Depth to ground water is about 110 m. Additional sampling ports were driven by hand to depths of 0.5, 1.0 and 1.5 m in May 1997. Initial samples of water vapor collected in April 1994 showed elevated tritium concentrations of more than 100 TU (tritium units) from all 10 air ports, with a maximum concentration of 762±10 TU from an air port at a depth of 24.1 m. Subsequent tritium concentrations increased in all air ports, although tritium concentrations at depths of less than 34.1 m have remained relatively constant since July 1995. The largest observed increase in tritium has been at a depth of 47.9 m. There, tritium concentration has increased from 198±5 TU in April 1994 to 2,570±30 TU in June 1998. Large increases also have been measured in samples collected from air ports at depths of 106.4 and 108.8 m, just above the water table.During September and October 1998, carbon dioxide samples were collected from all ten air ports in UZB-2 and at a depth of 1.5 m, and analyzed for radioactive carbon-14 (14C). 14C concentrations are highest in air ports at depths less than 6 m where they exceed 2,000 pmc (percent modern carbon). Concentrations decrease rapidly in air ports at depth and are about 20 pmc below 94.2 m. However, at 47.9 meters, the 14C concentration is 205±1 pmc, which is 2 to 4 times higher than concentrations in air ports immediately above and below. This depth corresponds to the largest tritium increase in UZB-2. Concentrations of both tritium and 14C are greater than what could be expected from atmospheric fallout. The distribution of tritium and 14C likely represent a complex pattern of lateral and vertical transport through the unsaturated zone from buried wastes to UZB-2.

• Two stroke homogenous charge compression ignition engine with pulsed air supplier

  DOEpatents

  Clarke, John M.

  2003-08-05

  A two stroke homogenous charge compression ignition engine includes a volume pulsed air supplier, such as a piston driven pump, for efficient scavenging. The usage of a homogenous charge tends to decrease emissions. The use of a volume pulsed air supplier in conjunction with conventional poppet type intake and exhaust valves results in a relatively efficient scavenging mode for the engine. The engine preferably includes features that permit valving event timing, air pulse event timing and injection event timing to be varied relative to engine crankshaft angle. The principle use of the invention lies in improving diesel engines.

• Properties of mixed molybdenum oxide iridium oxide thin films synthesized by spray pyrolysis

  NASA Astrophysics Data System (ADS)

  Patil, P. S.; Kawar, R. K.; Sadale, S. B.; Inamdar, A. I.; Deshmukh, H. P.

  2006-09-01

  Molybdenum-doped iridium oxide thin films have been deposited onto corning glass- and fluorine-doped tin oxide coated corning glass substrates at 350 °C by using a pneumatic spray pyrolysis technique. An aqueous solution of 0.01 M ammonium molybdate was mixed with 0.01 M iridium trichloride solution in different volume proportions and the resultant solution was used as a precursor solution for spraying. The as-deposited samples were annealed at 600 °C in air medium for 1 h. The structural, electrical and optical properties of as-deposited and annealed Mo-doped iridium oxide were studied and values of room temperature electrical resistivity, and thermoelectric power were estimated. The as-deposited samples with 2% Mo doping exhibit more pronounced electrochromism than other samples, including pristine Ir oxide.

• Equivalent Air Spring Suspension Model for Quarter-Passive Model of Passenger Vehicles.

  PubMed

  Abid, Haider J; Chen, Jie; Nassar, Ameen A

  2015-01-01

  This paper investigates the GENSIS air spring suspension system equivalence to a passive suspension system. The SIMULINK simulation together with the OptiY optimization is used to obtain the air spring suspension model equivalent to passive suspension system, where the car body response difference from both systems with the same road profile inputs is used as the objective function for optimization (OptiY program). The parameters of air spring system such as initial pressure, volume of bag, length of surge pipe, diameter of surge pipe, and volume of reservoir are obtained from optimization. The simulation results show that the air spring suspension equivalent system can produce responses very close to the passive suspension system.

• A Finite-Volume "Shaving" Method for Interfacing NASA/DAO''s Physical Space Statistical Analysis System to the Finite-Volume GCM with a Lagrangian Control-Volume Vertical Coordinate

  NASA Technical Reports Server (NTRS)

  Lin, Shian-Jiann; DaSilva, Arlindo; Atlas, Robert (Technical Monitor)

  2001-01-01

  Toward the development of a finite-volume Data Assimilation System (fvDAS), a consistent finite-volume methodology is developed for interfacing the NASA/DAO's Physical Space Statistical Analysis System (PSAS) to the joint NASA/NCAR finite volume CCM3 (fvCCM3). To take advantage of the Lagrangian control-volume vertical coordinate of the fvCCM3, a novel "shaving" method is applied to the lowest few model layers to reflect the surface pressure changes as implied by the final analysis. Analysis increments (from PSAS) to the upper air variables are then consistently put onto the Lagrangian layers as adjustments to the volume-mean quantities during the analysis cycle. This approach is demonstrated to be superior to the conventional method of using independently computed "tendency terms" for surface pressure and upper air prognostic variables.

• High-efficiency headspace sampling of volatile organic compounds in explosives using capillary microextraction of volatiles (CMV) coupled to gas chromatography-mass spectrometry (GC-MS).

  PubMed

  Fan, Wen; Almirall, José

  2014-03-01

  A novel geometry configuration based on sorbent-coated glass microfibers packed within a glass capillary is used to sample volatile organic compounds, dynamically, in the headspace of an open system or in a partially open system to achieve quantitative extraction of the available volatiles of explosives with negligible breakthrough. Air is sampled through the newly developed sorbent-packed 2 cm long, 2 mm diameter capillary microextraction of volatiles (CMV) and subsequently introduced into a commercially available thermal desorption probe fitted directly into a GC injection port. A sorbent coating surface area of ∼5 × 10(-2) m(2) or 5,000 times greater than that of a single solid-phase microextraction (SPME) fiber allows for fast (30 s), flow-through sampling of relatively large volumes using sampling flow rates of ∼1.5 L/min. A direct comparison of the new CMV extraction to a static (equilibrium) SPME extraction of the same headspace sample yields a 30 times improvement in sensitivity for the CMV when sampling nitroglycerine (NG), 2,4-dinitrotoluene (2,4-DNT), and diphenylamine (DPA) in a mixture containing a total mass of 500 ng of each analyte, when spiked into a liter-volume container. Calibration curves were established for all compounds studied, and the recovery was determined to be ∼1 % or better after only 1 min of sampling time. Quantitative analysis is also possible using this extraction technique when the sampling temperature, flow rate, and time are kept constant between calibration curves and the sample.

• Field Operations and Enforcement Manual for Air Pollution Control. Volume III: Inspection Procedures for Specific Industries.

  ERIC Educational Resources Information Center

  Weisburd, Melvin I.

  The Field Operations and Enforcement Manual for Air Pollution Control, Volume III, explains in detail the following: inspection procedures for specific sources, kraft pulp mills, animal rendering, steel mill furnaces, coking operations, petroleum refineries, chemical plants, non-ferrous smelting and refining, foundries, cement plants, aluminum…

• 40 CFR 86.1838-01 - Small-volume manufacturer certification procedures.

  Code of Federal Regulations, 2014 CFR

  2014-07-01

  ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE HIGHWAY VEHICLES AND ENGINES General Compliance Provisions for Control of Air Pollution From New and In-Use Light-Duty Vehicles, Light-Duty Trucks, and Complete Otto-Cycle Heavy-Duty Vehicles § 86.1838-01 Small-volume manufacturer...

Guide for SDEC Set up

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bibby, R; Guthrie, E

2009-01-30

The instrument has four collection vials that must be filled with ethylene glycol before operation. Each of the four vials should be labeled 1 through 4 and the empty weights recorded. Fill each vial with 80 mL of ethylene glycol and record the weight again. In order for the instrument to operate properly, the collection vials should always have less than 160 mL of total liquid in them. After completing a sample run, remove the collection vials, use a transfer pipette to remove any liquid that might still be on the air paddler, wipe off any condensation from the exteriormore » of the collection vial and record weight. From the instrument, record the ending volume and the time of operation. The solution mixed in the scintillation vial will be 2 ml of a 95% to 50% ethylene glycol to water mixture. To determine the efficiency of counting at all of these concentrations, a series of vials should be set up that consist of 18 ml of Ultima Gold LLT cocktail mixed with standard, regular deionized water and ethylene glycol. The efficiency curve should be counted in the 'Low Level' count mode with the Luminescence Correction ON and the Color Quench Correction ON. Once the tSIE values are determined, chart the cpm against the tSIE numbers and find the best fit for the data. The resulting equation is to be used to converting tSIE values from the collection vials to efficiency. To determine the background cpm value of the ethylene glycol, count a 2 ml sample of ethylene glycol with 18 ml of Ultima Gold for 100 minutes. To determine the total activity of the sample, take two 2 ml aliquots of sample from the first vial and place in separate scintillation vials. Record the weight of each aliquot. Determine the percentage of total sample each aliquot represents by dividing the aliquot weight by the total solution weight from the vial. Also, determine the percentage of ethylene glycol in the sample by dividing the initial solution weight by the final solution weight and multiplying by 100. Add 18 ml of Ultima Gold to each vial and proceed to count for 100 minutes in a 'Low Level' count mode. Before performing a calculation on the dpm value of each aliquot, a subtraction should be made for the background count rate of the ethylene glycol. Based on the background cpm, multiply the background cpm value by the percentage of ethylene glycol in the collection vial. Once the background value is subtracted, calculate the dpm value of the sample based on the tSIE conversion to efficiency. This will produce a dpm value. To convert this to a total activity of the sample, divide the aliquot dpm value by the decimal percentage of total sample the aliquot represents. This gives the total activity of the sample solution. Take the average of both aliquots as a final result. To convert the total activity from the solution in vial one to activity in air, an empirical formula is used to convert activity/gram from vial one to total activity introduced into the system. After calculation the final result for the vial, divide the total by the mass of the sample in vial one. This gives dpm/g (labeled C{sub m}). To convert this to total dpm measured, C = (128.59 * Cm + 10.837)/V Where: C = Tritium concentration in air (dpm/m{sup 3}) C{sub m} = measured tritium concentration from vial 1 (dpm/g) V = Volume of air sampled through instrument (m{sup 3}). C is the final value of tritium concentration in air.« less

Granulometric and magnetic properties of deposited particles in the Beijing subway and the implications for air quality management.

PubMed

Cui, Guipeng; Zhou, Liping; Dearing, John

2016-10-15

The subway system is an important traffic facility in Beijing and its internal air quality is an environmental issue that could potentially affect millions of people every day. Due to the intrinsic nature of rail abrasion in subway tunnels, iron-containing particles can be generated and become suspended in the subway environment. While some studies (e.g. Li et al., 2006) have monitored the in-train levels of PM2.5 (particles<2.5μm), there is a lack of systematic assessment of the concentration and characteristics of iron-containing particles in the Beijing subway system. Here we report results of a study on the granulometric and magnetic properties of deposited particle samples collected at different localities of the Beijing subway system. Our results show that the subway samples are characterized by the presence of fine particles. Volume proportions of 6.1±1.3% for particles<2.5μm and 27.5±6.1% for particles<10μm are found in the bulk subway samples. These samples exhibit a strong magnetic signal, which is approximately two orders of magnitude higher than that in naturally deposited particles collected in Beijing. Fine grained ferromagnetic and ferrimagnetic minerals (e.g. iron and magnetite, respectively) are identified from mineral magnetic measurements and scanning electric microscopy. The samples collected from the Beijing stations with platform screen doors are found to be magnetically stronger and finer than those without them, suggesting that platform screen doors have failed to block the fine iron-containing particles released from the rail tunnel. Given the potential health consequences of fine suspended iron-containing particles, our results have important implications for air quality management in the Beijing subway system. Copyright © 2016 Elsevier B.V. All rights reserved.

Current use pesticides in Arctic media; 2000-2007.

PubMed

Hoferkamp, Lisa; Hermanson, Mark H; Muir, Derek C G

2010-07-01

This review will summarize the levels of selected current use pesticides (CUPs) that have been identified and reported in Arctic media (i.e. air, water, sediment, and biota) since the year 2000. Almost all of the 10 CUPs (chlorothalonil, chlorpyrifos, dacthal, diazinon, dicofol, lindane, methoxychlor, pentachloronitrobenzene (PCNB), pentachlorophenol, and trifluralin) examined in the review currently are, or have been, high production volume chemicals i.e. >1M lbs/y in USA or >1000 t/y globally. Characteristic travel distances for the 10 chemicals range from 55 km (methoxychlor) to 12,100 km (PCNB). Surveys and long-term monitoring studies have demonstrated the presence of 9 of the 10 CUPs included in this review in the Arctic environment. Only dicofol has not been reported. The presence of these chemicals has mainly been reported in high volume air samples and in snow from Arctic ice caps and lake catchments. There are many other CUPs registered for use which have not been determined in Arctic environments. The discovery of the CUPs currently measured in the Arctic has been mainly serendipitous, a result of analyzing some samples using the same suite of analytes as used for studies in mid-latitude locations. A more systematic approach is needed to assess whether other CUPs might be accumulating in the arctic and ultimately to assess whether their presence has any significance biologically or results in risks for human consumers. Copyright 2009 Elsevier B.V. All rights reserved.

International Space Station Urine Monitoring System Functional Integration and Science Testing

NASA Technical Reports Server (NTRS)

Rodriguez, Branelle R.; Broyan, James Lee, Jr.

2008-01-01

Exposure to microgravity during human spaceflight is required to be defined and understood as the human exploration of space requires longer duration missions. It is known that long term exposure to microgravity causes bone loss. Urine voids are capable of measuring the calcium and other metabolic byproducts in a constituent s urine. The International Space Station (ISS) Urine Monitoring System (UMS) is an automated urine collection device designed to collect urine, separate the urine and air, measure the void volume, and allow for syringe sampling. Accurate measuring and minimal cross contamination is essential to determine bone loss and the effectiveness of countermeasures. The ISS UMS provides minimal cross contamination (<0.7 ml urine) and has volume accuracy of +/-2% between 100 to 1000 ml urine voids.

International Space Station Urine Monitoring System Functional Integration and Science Testing

NASA Technical Reports Server (NTRS)

Cibuzar, Branelle R.; Broyan, James Lee, Jr.

2009-01-01

Exposure to microgravity during human spaceflight is required to be defined and understood as the human exploration of space requires longer duration missions. It is known that long term exposure to microgravity causes bone loss. Urine voids are capable of measuring the calcium and other metabolic byproducts in a constituent s urine. The International Space Station (ISS) Urine Monitoring System (UMS) is an automated urine collection device designed to collect urine, separate the urine and air, measure the void volume, and allow for syringe sampling. Accurate measuring and minimal cross contamination is essential to determine bone loss and the effectiveness of countermeasures. The ISS UMS provides minimal cross contamination (<0.7 ml urine) and has volume accuracy of +/-2% between 100 to 1000 ml urine voids.

Absorbance and fluorometric sensing with capillary wells microplates.

PubMed

Tan, Han Yen; Cheong, Brandon Huey-Ping; Neild, Adrian; Liew, Oi Wah; Ng, Tuck Wah

2010-12-01

Detection and readout from small volume assays in microplates are a challenge. The capillary wells microplate approach [Ng et al., Appl. Phys. Lett. 93, 174105 (2008)] offers strong advantages in small liquid volume management. An adapted design is described and shown here to be able to detect, in a nonimaging manner, fluorescence and absorbance assays minus the error often associated with meniscus forming at the air-liquid interface. The presence of bubbles in liquid samples residing in microplate wells can cause inaccuracies. Pipetting errors, if not adequately managed, can result in misleading data and wrong interpretations of assay results; particularly in the context of high throughput screening. We show that the adapted design is also able to detect for bubbles and pipetting errors during actual assay runs to ensure accuracy in screening.

Reduction of secondhand tobacco smoke in public places following national smoke-free legislation in Uruguay.

PubMed

Blanco-Marquizo, Adriana; Goja, Beatriz; Peruga, Armando; Jones, Miranda R; Yuan, Jie; Samet, Jonathan M; Breysse, Patrick N; Navas-Acien, Ana

2010-06-01

Smoke-free legislation eliminating tobacco smoke in all indoor public places and workplaces is the international standard to protect all people from exposure to secondhand smoke. Uruguay was the first country in the Americas and the first middle-income country in the world to enact a comprehensive smoke-free national legislation in March 2006. To compare air nicotine concentrations measured in indoor public places and workplaces in Montevideo, Uruguay before (November 2002) and after (July 2007) the implementation of the national legislation. Air nicotine concentrations were measured for 7-14 days using the same protocol in schools, a hospital, a local government building, an airport and restaurants and bars. A total of 100 and 103 nicotine samples were available in 2002 and 2007, respectively. Median (IQR) air nicotine concentrations in the study samples were 0.75 (0.2-1.54) microg/m(3) in 2002 compared to 0.07 (0.0-0.20) microg/m(3) in 2007. The overall nicotine reduction comparing locations sampled in 2007 to those sampled in 2002 was 91% (95% CI 85% to 94%) after adjustment for differences in room volume and ventilation. The greatest nicotine reduction was observed in schools (97% reduction), followed by the airport (94% reduction), the hospital (89% reduction), the local government building (86% reduction) and restaurants/bars (81% reduction). Exposure to secondhand smoke has decreased greatly in indoor public places and workplaces in Montevideo, Uruguay, after the implementation of a comprehensive national smoke-free legislation. These findings suggest that it is possible to successfully implement smoke-free legislations in low and middle-income countries.

Micro-injector for capillary electrophoresis.

PubMed

Sáiz, Jorge; Koenka, Israel Joel; García-Ruiz, Carmen; Müller, Beat; Chwalek, Thomas; Hauser, Peter C

2015-08-01

A novel micro-injector for capillary electrophoresis for the handling of samples with volumes down to as little as 300 nL was designed and built in our laboratory for analyses in which the available volume is a limitation. The sample is placed into a small cavity located directly in front of the separation capillary, and the injection is then carried out automatically by controlled pressurization of the chamber with compressed air. The system also allows automated flushing of the injection chamber as well as of the capillary. In a trial with a capillary electrophoresis system with contactless conductivity detector, employing a capillary of 25 μm diameter, the results showed good stability of migration times and peak areas. To illustrate the technique, the fast separation of five inorganic cations (Na(+) , K(+) , NH4 (+) , Ca(2+) , and Mg(2+) ) was set up. This could be achieved in less than 3 min, with good limits of detection (10 μM) and linear ranges (between about 10 and 1000 μM). The system was demonstrated for the determination of the inorganic cations in porewater samples of a lake sediment core. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The mathematical model of radon-222 accumulation in underground mines

NASA Astrophysics Data System (ADS)

Klimshin, A.

2012-04-01

Necessity to control underground mine air radon level arises during building and operating mines as well as auto and railway tunnels including those for metros. Calculation of underground mine air radon level can be fulfilled for estimation of potential radon danger of area for underground structure building. In this work the new mathematical model of radon accumulation in underground mines has been suggested. It takes into consideration underground mine dimensions, air exchange factor and soils ability to emanate radon. The following assumptions have been taken for model development. It is assumed that underground mine is a cylinder of length L and of base area S. Due to ventilation atmosphere air of volume activity Catm, is coming in through one cylinder base and is going out of volume activity Cind from underground mine. Diffusion radon flux is coming in through side surfaces of underground mine. The sources of this flux are radium-226 atoms distributed evenly in rock. For simplification of the task it considered possible to disregard radon emanation by loosened rock and underground waters. As a result of solution of the radon diffusion equation the following expression for calculation of radon volume activity in underground space air has been got: 2·r0 ·λv ·Catm-·l·K0(r0/l)-+D-·K1(r0/l)·C0- Cind = 2·(λ+ λv)·r0 ·l·K0 (r0/l)+ D ·K1(r0/l) . The following designations are used in this expression: Kν(r) - the second genus modified Bessel's function, C0 - equilibrium radon volume activity in soil air, l - diffusion radon length in soil, D - radon diffusion factor, r0 - radius of underground tunnel, λv - factor of air exchange. Expression found may be used for calculation of the minimum factor of necessary air exchange for ensuring safe radon levels in underground spaces. With this worked out model expected levels of radon volume activity were calculated for air in the second metro line underground spaces in the city of Yekaterinburg, Russia.

The effect of undissolved air on isochoric freezing.

PubMed

Perez, Pedro A; Preciado, Jessica; Carlson, Gary; DeLonzor, Russ; Rubinsky, Boris

2016-06-01

This study evaluates the effect of undissolved air on isochoric freezing of aqueous solutions. Isochoric freezing is concerned with freezing in a constant volume thermodynamic system. A possible advantage of the process is that it substantially reduces the percentage of ice in the system at every subzero temperature, relative to atmospheric freezing. At the pressures generated by isochoric freezing, or high pressure isobaric freezing, air cannot be considered an incompressible substance and the presence of undissolved air substantially increases the amount of ice that forms at any subfreezing temperature. This effect is measurable at air volumes as low as 1%. Therefore eliminating the undissolved air, or any separate gaseous phase, from the system is essential for retaining the properties of isochoric freezing. Copyright © 2016. Published by Elsevier Inc.

[Measurement of air leak volume after lung surgery using web-camera].

PubMed

Onuki, Takamasa; Matsumoto, T

2005-05-01

Persistent air leak from the lung is one of the major complications after lung operations, especially in the latest thoracic surgery, where a shorter hospital stay tends to be necessary. However, air leak volume has been rarely measured clinically because accustomed tools of gas flow meter were types which needed contact measure, and those were unstable in long-term use and high cost. We tried to measure air leak volume as follows: (1) Bubble was made in the water seal part of a drain bag. (2) The movement of bubbles was recorded with a web-camera. (3) The data from the movie was analyzed by Linux computer on-line. We believe this method is clinically applicable as a routine work after lung surgery because of non-contact type of measurements, its stableness in long-term, easiness to be handled, and reasonable in cost.

The Conference Proceedings of the 2003 Air Transport Research Society (ATRS) World Conference, Volume 3

NASA Technical Reports Server (NTRS)

Bowen, Brent (Editor); Gudmundsson, Sveinn (Editor); Oum, Tae (Editor)

2003-01-01

Volume 3 of the 2003 Air Transport Reserch Society (ATRS) World Conference includes papers on topics relevant to airline operations worldwide. Specific topics include: European Union and civil aviation regimens;simulating decision making in airline operations, passenger points of view on convenient airports; route monopolies and nonlinear pricing; cooperation among airports in Europe; fleet modernizaiton in Brazil;the effects of deregulation on the growth of air transportation in Europe and the United States.

High Frontier: The Journal for Space and Missile Professionals. Volume 7, Number 3, May 2011

DTIC Science & Technology

2011-05-01

The Journal for Space & Missile Professionals. Volume 7, Number 3, May 2011 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6...AUTHOR(S) 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Air Force Space Command (AFSPC...Ingols . . . . . . . . . . . . . . 9 Winning in Cyberspace: Air Force Space Command’s Approach to Defending the Air Force Network Ms. Jill Baker

Large volume flow-through scintillating detector

DOEpatents

Gritzo, Russ E.; Fowler, Malcolm M.

1995-01-01

A large volume flow through radiation detector for use in large air flow situations such as incinerator stacks or building air systems comprises a plurality of flat plates made of a scintillating material arranged parallel to the air flow. Each scintillating plate has a light guide attached which transfers light generated inside the scintillating plate to an associated photomultiplier tube. The output of the photomultiplier tubes are connected to electronics which can record any radiation and provide an alarm if appropriate for the application.

Software OT&E Guidelines. Volume 3. Software Maintainability Evaluator’s Handbook

DTIC Science & Technology

1980-04-01

SOFTWARE OT&E " 1 GUIDELINES . VOLUME III SOFTWARE MAINTAINABILITY EVALUATOR’S HANDBOOK APRIL 1980 AIR FORCE TEST AND EVALUATION CENTER KIRTLAND AIR...FORCE BASE NEW MEXICO 87117 C-, -j AfTECP 800-3 AF’r...........3 ...... UNCLASSIFIED SECURITY CLASSIFICATION OF THIS PAGE (When D.. Entered) RE:PORT...c -. 5 TY!aJ0. PERIOD COVERED SOFTWARE OT& . GUIDELINES, Volume III .of five). -1 softare-R.aintainability Evaluator’s P-IEFnook’ 4ina. i 1980

Intercomparison of OH Radical Measurements by Long-Path Absorption and Laser Induced Fluorescence in the Atmosphere Simulation Chamber SAPHIR

NASA Astrophysics Data System (ADS)

Dorn, H.-P.; Brauers, T.; Greif, J.; Häseler, R.; Hofzumahaus, A.; Holland, F.; Rupp, L.

2003-04-01

A striking advantage of the SAPHIR chamber is the availability of two spectroscopic detection instruments for OH radicals: Laser-Induced Fluorescence Spectroscopy (LIF) and Long-Path Differential Optical Laser Absorption Spectroscopy (DOAS). Both instruments have already been compared in 1994 during the field measurement campaign POPCORN. They agreed well with a correlation coefficient of r=0.90 and a weighted linear fit with a slope of 1.09 +- 0.12. However, OH measurements in the simulation chamber differ significantly from measurements in ambient air. While DOAS measures OH as an integral value along the central longitudinal axis of SAPHIR, LIF samples the air locally and close (2 cm) to the floor of the chamber. Thus, the LIF measurements might be possibly affected by local concentration gradients caused by insufficient mixing of the chamber air or by deposition to the wall. On the other hand, if turbulent mixing of the chamber air is weak and high concentrations of ozone are used in experiments, the DOAS instrument might be subject to artificial formation of OH radicals in the air volume which is illuminated by the detection laser. This interference results from laser induced photolysis of ozone and the subsequent reaction of water vapor with the excited oxygen atoms formed. Thus it is of decisive importance to compare OH measurements from both instruments in order to investigate potential disturbing effects due to the specific sampling properties of both instruments within SAPHIR. We report on OH measurements accomplished simultaneously with both instruments using different trace gas compositions and experimental conditions.

Cost characteristics of tilt-rotor, conventional air and high speed rail short-haul intercity passenger service

NASA Technical Reports Server (NTRS)

Schoendorfer, David L.; Morlok, Edward K.

1985-01-01

The cost analysis done to support an assessment of the potential for a small tilt-rotor aircraft to operate in short-haul intercity passenger service is described in detail. Anticipated costs of tilt-rotor air service were compared to the costs of two alternatives: conventional air and high speed rail (HSR). Costs were developed for corridor service, varying key market characteristics including distance, passenger volumes, and minimum frequency standards. The resulting cost vs output information can then be used to compare modal costs for essentially identical service quality and passenger volume or for different service levels and volumes for each mode, as appropriate. Extensive sensitivity analyses are performed. The cost-output features of these technologies are compared. Tilt-rotor is very attractive compared to HSR in terms of costs over the entire range of volume. It also has costs not dramatically different from conventional air, but tilt-rotor costs are generally higher. Thus some of its other advantages, such as the VTOL capability, must offset the cost disadvantage for it to be a preferred or competitive mode in any given market. These issues are addressed in the companion report which considers strategies for tilt-rotor development in commercial air service.

Effectiveness of Needleless Vial Adaptors and Blunt Cannulas for Drug Administration in a Microgravity Environment

NASA Technical Reports Server (NTRS)

Hailey, M.; Bayuse, T.

2010-01-01

Fluid Isolation in the medication vial: Air/ fluid isolation maneuvers were used to move the medication to the septum end of vial. This isolation may be achieved in multiple ways based on the experience of the astronaut with fluid management in microgravity. If vial adaptors/blunt cannula or syringe assembly is inserted into the to vial before fluid isolation commences, the stability of this assembly should be considered in an effort to limit the risk of "slinging off" of the vial during isolation. Alternatively, fluid isolation can be performed prior to attaching the syringe/vial adaptor assembly. Terrestrial practices for medication withdrawal from a nonvented vial require injection of an equivalent amount of air as the expected medication volume prior to withdrawing liquid. In microgravity, this action is still valid, however the injection of additional air into the vial creates a multitude of micro bubbles and increases the volume of medication mixed with air that then must be withdrawn to achieve the desired drug volume in syringe. This practice is more likely to be required when using vials >30ml in size and injection volumes >10mL. It is felt that based on the microgravity flight, the practice of air injection is more of a hindrance than help.

Volume requirements for aerated mud drilling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, B.; Rajtar, J.M.

1995-09-01

Aerated mud drilling has been recognized as having many advantages over conventional mud drilling, such ass higher penetration rate, less formation damage, minimized lost circulation, and lower drilling cost. In some areas, the use of aerated mud as a circulating medium for drilling oil and gas wells is becoming an attractive practice. Maintaining an optimum combination of liquid and air flow rates is important in aerated drilling operations. However, most drilling operators are unclear on what constitutes the ``optimum combination of the liquid and air flow rates.`` Guo et al. presented a mathematical approach to determining the flowing bottomhole pressuremore » (BHP) for aerated mud drilling. This paper addresses the use of Guo et al.`s mathematical model to determine liquid and air volume requirements considering wellbore stability, pipe sticking, and formation damage as well as the cuttings-carry capacity of the aerated mud. For a formation-damage-prevention point of view, the liquid fraction in the fluid stream should e as low as possible. However, a sufficient mud flow rate is always required to make the hole stable and to maintain the cuttings-carrying capacity of the aerated mud without injecting much air volume. This paper provides a simple approach to determining the liquid and air volume requirements for aerated mud drilling.« less

Air Versus Sulfur Hexafluoride Gas Tamponade in Descemet Membrane Endothelial Keratoplasty: A Fellow Eye Comparison.

PubMed

von Marchtaler, Philipp V; Weller, Julia M; Kruse, Friedrich E; Tourtas, Theofilos

2018-01-01

To perform a fellow eye comparison of outcomes and complications when using air or sulfur hexafluoride (SF6) gas as a tamponade in Descemet membrane endothelial keratoplasty (DMEK). One hundred thirty-six eyes of 68 consecutive patients who underwent uneventful DMEK in both eyes for Fuchs endothelial corneal dystrophy were included in this retrospective study. Inclusion criteria were air tamponade (80% of the anterior chamber volume) in the first eye and 20% SF6 gas tamponade (80% of the anterior chamber volume) in the second eye; and same donor tissue culture condition in both eyes. All eyes received laser iridotomy on the day before DMEK. Main outcome measures included preoperative and postoperative best-corrected visual acuity, endothelial cell density, corneal volume, rebubbling rate, and rate of postoperative pupillary block caused by the air/gas bubble. Thirteen of 68 eyes (19.1%) with an air tamponade needed rebubbling compared with 4 of 68 eyes (5.9%) with an SF6 gas tamponade (P = 0.036). Postoperative pupillary block necessitating partial release of air/gas occurred in 1 eye (1.5%) with an air tamponade and 3 eyes (4.4%) with an SF6 gas tamponade (P = 0.301). There were no significant differences in preoperative and postoperative best-corrected visual acuity, endothelial cell density, and corneal volume within 3-month follow-up. Our results confirm the previously reported better graft adhesion when using an SF6 gas tamponade in DMEK without increased endothelial cell toxicity. The rate of pupillary block in eyes with an SF6 gas tamponade was comparable to that with an air tamponade. As a consequence, we recommend using SF6 gas as the tamponade in DMEK.