43 CFR 3430.4-4 - Environmental costs.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and analyzing baseline data on surface water quality and quantity (collecting and analyzing samples...). (2) Groundwater—costs of collecting and analyzing baseline data on groundwater quality and quantity... analyzing baseline air quality data (purchasing rain, air direction, and wind guages and air samplers and...

43 CFR 3430.4-4 - Environmental costs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and analyzing baseline data on surface water quality and quantity (collecting and analyzing samples...). (2) Groundwater—costs of collecting and analyzing baseline data on groundwater quality and quantity... analyzing baseline air quality data (purchasing rain, air direction, and wind guages and air samplers and...

43 CFR 3430.4-4 - Environmental costs.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and analyzing baseline data on surface water quality and quantity (collecting and analyzing samples...). (2) Groundwater—costs of collecting and analyzing baseline data on groundwater quality and quantity... analyzing baseline air quality data (purchasing rain, air direction, and wind guages and air samplers and...

Study on Aerosol Penetration Through Clothing and Individual Protective Equipment

DTIC Science & Technology

2009-05-01

8.4X10-3 mg.m-3 (2.57X105 particles per cubic meter of air) over a 30 minute period. This scenario represents a very high end threat with a large... Isokinetic air sampling was applied and the effect of aerosol losses in sampling lines and other parts of the test rig were incorporated in analysis...eliminate any “memory” effect. The aerosol sampling (airflow direction control, start of sampling) was operated manually. Isokinetic sampling conditions

Increased levels of ethane, a non-invasive, quantitative, direct marker of n-3 lipid peroxidation, in the breath of patients with schizophrenia.

PubMed

Puri, Basant K; Ross, Brian M; Treasaden, Ian H

2008-04-01

This study directly assessed whether there was a change in the level of exhaled ethane, which provides a non-invasive, quantitative, direct measure of n-3 lipid peroxidation, in the breath of patients with schizophrenia. Samples of alveolar air were obtained from 20 subjects with schizophrenia and 23 age- and sex-matched healthy control subjects. The air samples were analyzed for ethane using mass spectrometry. The mean level of ethane in the schizophrenia sample [5.15 (S.E. 0.56) ppb] was significantly higher than that of the healthy controls [2.63 (S.E. 0.31) ppb; p<0.0005]. A further sub-analysis showed that nicotine dependence was unlikely to be the cause of this difference. These results suggest that the measurement of exhaled ethane levels may offer a non-invasive direct biomarker of increased n-3 lipid peroxidation in schizophrenia.

A new device for dynamic sampling of radon in air

NASA Astrophysics Data System (ADS)

Lozano, J. C.; Escobar, V. Gómez; Tomé, F. Vera

2000-08-01

A new system is proposed for the active sampling of radon in air, based on the well-known property of activated charcoal to retain radon. Two identical carbon-activated cartridges arranged in series remove the radon from the air being sampled. The air passes first through a desiccant cell and then the carbon cartridges for short sampling times using a low-flow pump. The alpha activity for each cartridge is determined by a liquid scintillation counting system. The cartridge is placed in a holder into a vial that also contains the appropriate amount of scintillation cocktail, in a way that avoids direct contact between cocktail and charcoal. Once dynamic equilibrium between the phases has been reached, the vials can be counted. Optimum sampling conditions concerning flow rates and sampling times are determined. Using those conditions, the method was applied to environmental samples, straightforwardly providing good results for very different levels of activity.

A metagenomic framework for the study of airborne microbial communities.

PubMed

Yooseph, Shibu; Andrews-Pfannkoch, Cynthia; Tenney, Aaron; McQuaid, Jeff; Williamson, Shannon; Thiagarajan, Mathangi; Brami, Daniel; Zeigler-Allen, Lisa; Hoffman, Jeff; Goll, Johannes B; Fadrosh, Douglas; Glass, John; Adams, Mark D; Friedman, Robert; Venter, J Craig

2013-01-01

Understanding the microbial content of the air has important scientific, health, and economic implications. While studies have primarily characterized the taxonomic content of air samples by sequencing the 16S or 18S ribosomal RNA gene, direct analysis of the genomic content of airborne microorganisms has not been possible due to the extremely low density of biological material in airborne environments. We developed sampling and amplification methods to enable adequate DNA recovery to allow metagenomic profiling of air samples collected from indoor and outdoor environments. Air samples were collected from a large urban building, a medical center, a house, and a pier. Analyses of metagenomic data generated from these samples reveal airborne communities with a high degree of diversity and different genera abundance profiles. The identities of many of the taxonomic groups and protein families also allows for the identification of the likely sources of the sampled airborne bacteria.

A Metagenomic Framework for the Study of Airborne Microbial Communities

PubMed Central

Tenney, Aaron; McQuaid, Jeff; Williamson, Shannon; Thiagarajan, Mathangi; Brami, Daniel; Zeigler-Allen, Lisa; Hoffman, Jeff; Goll, Johannes B.; Fadrosh, Douglas; Glass, John; Adams, Mark D.; Friedman, Robert; Venter, J. Craig

2013-01-01

Understanding the microbial content of the air has important scientific, health, and economic implications. While studies have primarily characterized the taxonomic content of air samples by sequencing the 16S or 18S ribosomal RNA gene, direct analysis of the genomic content of airborne microorganisms has not been possible due to the extremely low density of biological material in airborne environments. We developed sampling and amplification methods to enable adequate DNA recovery to allow metagenomic profiling of air samples collected from indoor and outdoor environments. Air samples were collected from a large urban building, a medical center, a house, and a pier. Analyses of metagenomic data generated from these samples reveal airborne communities with a high degree of diversity and different genera abundance profiles. The identities of many of the taxonomic groups and protein families also allows for the identification of the likely sources of the sampled airborne bacteria. PMID:24349140

Biobriefcase electrostatic aerosol collector

DOEpatents

Bell, Perry M [Tracy, CA; Christian, Allen T [Madison, WI; Bailey, Christopher G [Pleasanton, CA; Willis, Ladona [Manteca, CA; Masquelier, Donald A [Tracy, CA; Nasarabadi, Shanavaz L [Livermore, CA

2009-03-17

A system for sampling air and collecting particles entrained in the air comprising a receiving surface, a liquid input that directs liquid to the receiving surface and produces a liquid surface, an air input that directs the air so that the air with particles entrained in the air impact the liquid surface, and an electrostatic contact connected to the liquid that imparts an electric charge to the liquid. The particles potentially including bioagents become captured in the liquid by the air with particles entrained in the air impacting the liquid surface. Collection efficiency is improved by the electrostatic contact electrically charging the liquid. The effects of impaction and adhesion due to electrically charging the liquid allows a unique combination in a particle capture medium that has a low fluid consumption rate while maintaining high efficiency.

Chemical trends in background air quality and the ionic composition of precipitation for the period 1980-2004 from samples collected at Valentia Observatory, Co. Kerry, Ireland.

PubMed

Bashir, Wasim; McGovern, Frank; O'Brien, Phillip; Ryan, Margaret; Burke, Liam; Paull, Brett

2008-06-01

A major Irish study, based upon more than 8000 samples collected over the measurement period of 22 years, for sulfur dioxide (SO2-S), sulfate (SO4-S) and nitrogen dioxide (NO2-N) concentrations (microg m(-3)) within air, and the ionic composition of precipitation samples based on sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), chloride (Cl-), sulfate (SO4-S), non-sea salt sulfate (nssSO4-S), ammonium (NH4-N), and nitrate (NO3-N) weighted mean concentrations (mg l(-1)), has been completed. For the air samples, the sulfur dioxide and sulfate concentrations decreased over the sampling period (1980-2004) by 75% and 45%, respectively, whereas no significant trend was observed for nitrogen dioxide. The highest concentrations for sulfur dioxide, sulfate and nitrogen dioxide were associated with wind originating from the easterly and northeasterly directions i.e. those influenced by Irish and European sources. The lowest concentrations were associated with the westerly directions i.e. for air masses originating in the North Atlantic region. This was further verified with the use of backward (back) trajectory analysis, which allowed tracing the movement of air parcels using the European Centre for Medium range Weather Forecasting (ECMWF) ERA-40 re-analysis data. High non-sea salt sulfate levels were being associated with air masses originating from Europe (easterlies) with lower levels from the Atlantic (westerlies). With the precipitation data, analysis of the non-sea salt sulfate concentrations showed a decrease by 47% since the measurements commenced.

Automation of a Large Analytical Chemistry Laboratory

DTIC Science & Technology

1990-12-01

Division Brooks Air Force Base , Texas 78235-5501 NOTICES When Government drawings, specifications, or other data are used for any purpose other than a...been reviewed and is approved for publication. Air Force installations may direct requests for copies of this report to: Air Force Occupational and...remaining for the analyses. Our laboratory serves worldwide Air Force installations and therefore comes up against these sample holding time requirements

Automatic electrochemical ambient air monitor for chloride and chlorine

DOEpatents

Mueller, Theodore R.

1976-07-13

An electrochemical monitoring system has been provided for determining chloride and chlorine in air at levels of from about 10-1000 parts per billion. The chloride is determined by oxidation to chlorine followed by reduction to chloride in a closed system. Chlorine is determined by direct reduction at a platinum electrode in 6 M H.sub.2 SO.sub.4 electrolyte. A fully automated system is utilized to (1) acquire and store a value corresponding to electrolyte-containing impurities, (2) subtract this value from that obtained in the presence of air, (3) generate coulometrically a standard sample of chlorine mixed with air sample, and determine it as chlorine and/or chloride, and (4) calculate, display, and store for permanent record the ratio of the signal obtained from the air sample and that obtained with the standard.

Detection of Mycoplasma hyopneumoniae by Air Sampling with a Nested PCR Assay

PubMed Central

Stärk, Katharina D. C.; Nicolet, Jacques; Frey, Joachim

1998-01-01

This article describes the first successful detection of airborne Mycoplasma hyopneumoniae under experimental and field conditions with a new nested PCR assay. Air was sampled with polyethersulfone membranes (pore size, 0.2 μm) mounted in filter holders. Filters were processed by dissolution and direct extraction of DNA for PCR analysis. For the PCR, two nested pairs of oligonucleotide primers were designed by using an M. hyopneumoniae-specific DNA sequence of a repeated gene segment. A nested PCR assay was developed and used to analyze samples collected in eight pig houses where respiratory problems had been common. Air was also sampled from a mycoplasma-free herd. The nested PCR was highly specific and 104 times as sensitive as a one-step PCR. Under field conditions, the sampling system was able to detect airborne M. hyopneumoniae on 80% of farms where acute respiratory disease was present. No airborne M. hyopneumoniae was detected on infected farms without acute cases. The chance of successful detection was increased if air was sampled at several locations within a room and at a lower air humidity. PMID:9464391

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

The atmosphere can be a source of certain water soluble volatile organic compounds in urban streams

USGS Publications Warehouse

Kenner, Scott J.; Bender, David A.; Zogorski, John S.; ,; James F. Pankow,

2014-01-01

Surface water and air volatile organic compound (VOC) data from 10 U.S. Geological Survey monitoring sites were used to evaluate the potential for direct transport of VOCs from the atmosphere to urban streams. Analytical results of 87 VOC compounds were screened by evaluating the occurrence and detection levels in both water and air, and equilibrium concentrations in water (Cws) based on the measured air concentrations. Four compounds (acetone, methyl tertiary butyl ether, toluene, and m- & p-xylene) were detected in more than 20% of water samples, in more than 10% of air samples, and more than 10% of detections in air were greater than long-term method detection levels (LTMDL) in water. Benzene was detected in more than 20% of water samples and in more than 10% of air samples. Two percent of benzene detections in air were greater than one-half the LTMDL in water. Six compounds (chloroform, p-isopropyltoluene, methylene chloride, perchloroethene, 1,1,1-trichloroethane, and trichloroethene) were detected in more than 20% of water samples and in more than 10% of air samples. Five VOCs, toluene, m- & p-xylene, methyl tert-butyl ether (MTBE), acetone, and benzene were identified as having sufficiently high concentrations in the atmosphere to be a source to urban streams. MTBE, acetone, and benzene exhibited behavior that was consistent with equilibrium concentrations in the atmosphere.

Personal exposure to volatile organic compounds. I. Direct measurements in breathing-zone air, drinking water, food, and exhaled breath

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

Wallace, L.A.; Pellizzari, E.; Hartwell, T.

A pilot study to test methods of estimating personal exposures to toxic substances and corresponding body burdens was carried out between July and December 1980. Individual exposures to about a dozen volatile organic compounds in air and drinking water were measured for volunteers in New Jersey and North Carolina. Breath samples were also collected from all subjects. About 230 personal air samples, 170 drinking water samples, 66 breath samples, and 4 food samples (16 composites) were analyzed for the target chemicals. Ten compounds were present in air and eight were transmitted mainly through that medium. Chloroform and bromodichloromethane were predominantlymore » transmitted through water and beverages. Food appeared to be a miner route of exposure, except possibly for trichloroethylene in margarine. Seven compounds were present in more than half of the breath samples. Diurnal and seasonal variations were noted in air and water concentrations of some compounds. Some, but not all, of the potentially occupationally exposed individuals had significantly higher workplace exposures to several chemicals. Distributions of air exposures were closer to log normal than normal for most chemicals. Several chemicals were highly correlated with each other in personal air samples, indicating possible common sources of exposures. Compounds detected included benzene, chlorinated aromatic hydrocarbons, chlorinated aliphatic hydrocarbons, halogens and vinyl chloride.« less

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

Subtask 3.9 - Direct Coal Liquefaction Process Development

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

Aulich, Ted; Sharma, Ramesh

The Energy and Environmental Research Center (EERC), in partnership with the U.S. Department of Energy (DOE) and Accelergy Corporation, an advanced fuels developer with technologies exclusively licensed from ExxonMobil, undertook Subtask 3.9 to design, build, and preliminarily operate a bench-scale direct coal liquefaction (DCL) system capable of converting 45 pounds/hour of pulverized, dried coal to a liquid suitable for upgrading to fuels and/or chemicals. Fabrication and installation of the DCL system and an accompanying distillation system for off-line fractionation of raw coal liquids into 1) a naphtha middle distillate stream for upgrading and 2) a recycle stream was completed inmore » May 2012. Shakedown of the system was initiated in July 2012. In addition to completing fabrication of the DCL system, the project also produced a 500-milliliter sample of jet fuel derived in part from direct liquefaction of Illinois No. 6 coal, and submitted the sample to the Air Force Research Laboratory (AFRL) at Wright Patterson Air Force Base, Dayton, Ohio, for evaluation. The sample was confirmed by AFRL to be in compliance with all U.S. Air Force-prescribed alternative aviation fuel initial screening criteria.« less

Modeling 3D conjugate heat and mass transfer for turbulent air drying of Chilean papaya in a direct contact dryer

NASA Astrophysics Data System (ADS)

Lemus-Mondaca, Roberto A.; Vega-Gálvez, Antonio; Zambra, Carlos E.; Moraga, Nelson O.

2017-01-01

A 3D model considering heat and mass transfer for food dehydration inside a direct contact dryer is studied. The k- ɛ model is used to describe turbulent air flow. The samples thermophysical properties as density, specific heat, and thermal conductivity are assumed to vary non-linearly with temperature. FVM, SIMPLE algorithm based on a FORTRAN code are used. Results unsteady velocity, temperature, moisture, kinetic energy and dissipation rate for the air flow are presented, whilst temperature and moisture values for the food also are presented. The validation procedure includes a comparison with experimental and numerical temperature and moisture content results obtained from experimental data, reaching a deviation 7-10 %. In addition, this turbulent k- ɛ model provided a better understanding of the transport phenomenon inside the dryer and sample.

Formation of halogenated acetones in the lower troposphere

NASA Astrophysics Data System (ADS)

Sattler, Tobias; Wittmer, Julian; Krause, Torsten; Schöler, Heinz Friedrich; Kamilli, Katharina; Held, Andreas; Zetzsch, Cornelius; Ofner, Johannes; Atlas, Elliot

2015-04-01

Western Australia is a semi-/arid region that is heavily influenced by climate change and agricultural land use. The area is known for its saline lakes with a wide range of hydrogeochemical parameters and consists of ephemeral saline and saline groundwater fed lakes with a pH range from 2.5 to 7.1. In 2012 a novel PTFE-chamber was setup directly on the lakes. The 1.5 m³ cubic chamber was made of UV transparent PTFE foil to permit photochemistry while preventing dilution of the air due to lateral wind transport. This experimental setup allows linking measured data directly to the chemistry of and above the salt lakes. Air samples were taken using stainless steel canisters and measured by GC-MS/ECD. Sediment, crust and water samples were taken for investigation of potential VOC and VOX emissions in the laboratory using GC-MS. Several lakes were investigated and canister samples were taken over the day to see diurnal variations. The first samples were collected at 6 a.m. and from this time every 2 hours a canister was filled with chamber air. Concentrations of chloroacetone up to 15 ppb and of bromoacetone up to 40 ppb in the air samples were detected. The concentrations vary over the day and display their highest values around noon. Soil and water samples showed a variety of highly volatile and semi-volatile VOC/VOX but no halogenated acetones. An abiotic formation of these VOC/VOX seems conclusive due to iron-catalysed reactions below the salt crust [1]. The salt crust is the interface through which VOC/VOX pass from soil/groundwater to the atmosphere where they were photochemically altered. This explains the finding of halo acetones only in the air samples and not in water and soil samples measured in the laboratory. The main forming pathway for these haloacetones is the direct halogenation due to atomic chlorine and bromine above the salt lakes [2]. A minor pathway is the atmospheric degradation of chloropropane and bromopropane [3]. These halopropanes were found in minor concentrations in soil and water samples (maximum of 8.8 ng/g in soil and 0,012 ng/ml in water). [1] Huber et al., 2009, Environ.Sci.Technol., 43 (13), 4934-4939 [2] Wittmer et al., 2014, J. Phys. Chem. A, DOI: 10.1021/jp508006s [3] Burkholder et al., 2002, Geophysical Research Letters, 29 (17)

Three field tests of a gas filter correlation radiometer

NASA Technical Reports Server (NTRS)

Campbell, S. A.; Casas, J. C.; Condon, E. P.

1977-01-01

Test flights to remotely measure nonurban carbon monoxide (CO) concentrations by gas filter correlation radiometry are discussed. The inferred CO concentrations obtained through use of the Gas Filter Correlation Radiometer (GFCR) agreed with independent measurements obtained by gas chromatography air sample bottle analysis to within 20 percent. The equipment flown on board the aircraft, the flight test procedure, the gas chromatograph direct air sampling procedure, and the GFCR data analysis procedure are reported.

Tests of a High Temperature Sample Conditioner for the Waste Treatment Plant LV-S2, LV-S3, HV-S3A and HV-S3B Exhaust Systems

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

Flaherty, Julia E.; Glissmeyer, John A.

2015-03-18

Tests were performed to evaluate a sample conditioning unit for stack monitoring at Hanford Tank Waste Treatment and Immobilization Plant (WTP) exhaust stacks with elevated air temperatures. The LV-S2, LV-S3, HV-S3A and HV-S3B exhaust stacks are expected to have elevated air temperature and dew point. At these emission points, exhaust temperatures are too high to deliver the air sample directly to the required stack monitoring equipment. As a result, a sample conditioning system is considered to cool and dry the air prior to its delivery to the stack monitoring system. The method proposed for the sample conditioning is a dilutionmore » system that will introduce cooler, dry air to the air sample stream. This method of sample conditioning is meant to reduce the sample temperature while avoiding condensation of moisture in the sample stream. An additional constraint is that the ANSI/HPS N13.1-1999 standard states that at least 50% of the 10 μm aerodynamic diameter (AD) particles present in the stack free stream must be delivered to the sample collector. In other words, depositional loss of particles should be limited to 50% in the sampling, transport, and conditioning systems. Based on estimates of particle penetration through the LV-S3 sampling system, the diluter should perform with about 80% penetration or better to ensure that the total sampling system passes the 50% or greater penetration criterion.« less

Microbiota and Particulate Matter Assessment in Portuguese Optical Shops Providing Contact Lens Services

PubMed Central

Viegas, Carla; Faria, Tiago; Pacífico, Cátia; Dos Santos, Mateus; Monteiro, Ana; Lança, Carla; Carolino, Elisabete; Viegas, Susana; Cabo Verde, Sandra

2017-01-01

The aim of this work was to assess the microbiota (fungi and bacteria) and particulate matter in optical shops, contributing to a specific protocol to ensure a proper assessment. Air samples were collected through an impaction method. Surface and equipment swab samples were also collected side-by-side. Measurements of particulate matter were performed using portable direct-reading equipment. A walkthrough survey and checklist was also applied in each shop. Regarding air sampling, eight of the 13 shops analysed were above the legal requirement and 10 from the 26 surfaces samples were overloaded. In three out of the 13 shops fungal contamination in the analysed equipment was not detected. The bacteria air load was above the threshold in one of the 13 analysed shops. However, bacterial counts were detected in all sampled equipment. Fungi and bacteria air load suggested to be influencing all of the other surface and equipment samples. These results reinforce the need to improve air quality, not only to comply with the legal requirements, but also to ensure proper hygienic conditions. Public health intervention is needed to assure the quality and safety of the rooms and equipment in optical shops that perform health interventions in patients. PMID:28505144

Aerosol Sampling with Low Wind Sensitivity.

NASA Astrophysics Data System (ADS)

Kalatoor, Suresh

Occupational exposure to airborne particles is generally evaluated by wearing a personal sampler that collects aerosol particles from the worker's breathing zone during the work cycle. The overall sampling efficiency of most currently available samplers is sensitive to wind velocity and direction. In addition, most samplers have internal losses due to gravitational settling, electrostatic interactions, and internal turbulence. A new sampling technique has been developed, theoretically and experimentally evaluated, and compared to existing techniques. The overall sampling efficiency of the protoype sampler was compared to that of a commonly used sampler, 25 mm closed-face cassette. Uranine was used as the challange aerosol with particle physical diameters 13.5, 20 and 30 mum. The wind velocity ranged from 100 to 300 cm s^ {-1}. It was found to have less internal losses and less dependence on wind velocity and direction. It also yielded better uniformity in the distribution of large particles on the filter surface, an advantage for several types of analysis. A new general equation for sharp-edged inlets was developed that predicts the sampling efficiency of sharp-edged (or thin-walled) inlets in most occupational environments that are weakly disturbed with air motions that cannot be strictly classified as calm-air or fast -moving air. Computational analysis was carried out using the new general equation and was applied to situations when the wind velocity vector is not steady, but fluctuates around predominant average values of its magnitude and orientation. Two sampling environments, horizontal aerosol flow (ambient atmosphere) and vertical aerosol flow (industrial stacks) have been considered. It was found, that even for small fluctuations in wind direction the sampling efficiency may be significantly less than that obtained for the mean wind direction. Time variations in wind magnitude at a fixed wind direction were found to affect the sampling efficiency to a lesser degree. This led to the development of a new sampling technique that significantly improved the sampling characteristics of the inlet. The newly-developed inlet has a curved surface with evenly spaced sampling orifices. Visualization of the streamlines over the sampler and limiting-streamline quantitative analysis showed negligible turbulence effects due to the sampler inlet's geometry. The overall sampling efficiency was found to be superior over the commonly used 25-mm closed-face cassette.

Comparison and harmonization of measuring methods for air contaminants in the working environment.

PubMed

Leichnitz, K

1998-09-01

The objective of this work was to demonstrate that the measurement of air contaminants in the workplace requires a special approach. Decisive in carrying out the measuring task is the quality of the sampling strategy, including selection of the appropriate measuring method. Methods developed at a national level may be more suitable for this purpose than methods described in international standards. Measurements of air contaminants in the workplace should always be the basis for the prevention and control of occupational hazards. Such measurements, therefore, are also an essential element of risk assessment. Industrial processes and chemical agents are myriad. Each manufacturing stage may apply different conditions (e.g., batch production or continuous process, temperature, pressure) and agents (e.g. a wide variety of chemical substances): In each of these stages, different job functions may be necessary and may be subject to different exposure conditions. Distance from emission sources and physical parameters, such as rates of release, air current, meteorological variations, also have a profound influence. The measuring task in the workplace is quite different in comparison to many others (e.g., blood or soil sample analysis). Firstly, the selection of sampling time and sampling location are crucial steps in air analysis. Transportation and storage of the samples, may however, also influence measuring results; interlaboratory tests show the existing problems. Generally, in analytics, the substance to be determined remains "well covered" in its matrix during sampling, transportation and storage. In air analysis, however, the contaminant is usually "torn" from its surrounding matrix (the air) and "forced" into the sorbent, where it finds a completely new environment; reactions yielding artefacts may take place. Several international organizations have issued guidelines and standards on measuring methods for air contaminants in the working environment, such as the World Health Organization (WHO), the International Union of Pure and Applied Chemistry (IUPAC), and the International Organization for Standardization (ISO). Most of these international documents are substance-related and mainly cover the analytical steps, which constitute only part of the whole measuring process. The approach of the Commission of the European Union is useful in solving the task of air testing in the workplace. This body has issued an EU Directive which includes general requirements for measuring methods. In the Directive it is also stated that persons who carry out measurements must possess the necessary expertise. The Directive, in addition, refers to the European Committee for Standardization (CEN), and that to general requirements for measuring procedures. The advantage of the EU/CEN approach is its aspect of general requirements. This allows the development of new or improved methods without any restricting effect on existing substance-related standards.

Design and laboratory testing of a new flow-through directional passive air sampler for ambient particulate matter.

PubMed

Lin, Chun; Solera Garcia, Maria Angeles; Timmis, Roger; Jones, Kevin C

2011-03-01

A new type of directional passive air sampler (DPAS) is described for collecting particulate matter (PM) in ambient air. The prototype sampler has a non-rotating circular sampling tray that is divided into covered angular channels, whose ends are open to winds from sectors covering the surrounding 360°. Wind-blown PM from different directions enters relevant wind-facing channels, and is retained there in collecting pools containing various sampling media. Information on source direction and type can be obtained by examining the distribution of PM between channels. Wind tunnel tests show that external wind velocities are at least halved over an extended area of the collecting pools, encouraging PM to settle from the air stream. Internal and external wind velocities are well-correlated over an external velocity range of 2.0-10.0 m s⁻¹, which suggests it may be possible to relate collected amounts of PM simply to ambient concentrations and wind velocities. Measurements of internal wind velocities in different channels show that velocities decrease from the upwind channel round to the downwind channel, so that the sampler effectively resolves wind directions. Computational fluid dynamics (CFD) analyses were performed on a computer-generated model of the sampler for a range of external wind velocities; the results of these analyses were consistent with those from the wind tunnel. Further wind tunnel tests were undertaken using different artificial particulates in order to assess the collection performance of the sampler in practice. These tests confirmed that the sampler can resolve the directions of sources, by collecting particulates preferentially in source-facing channels.

Pesticides in Mississippi air and rain: A comparison between 1995 and 2007

USGS Publications Warehouse

Majewski, Michael S; Coupe, Richard H.; Foreman, William T.; Capel, Paul D.

2014-01-01

A variety of current-use pesticides were determined in weekly composite air and rain samples collected during the 1995 and 2007 growing seasons in the Mississippi Delta (MS, USA) agricultural region. Similar sampling and analytical methods allowed for direct comparison of results. Decreased overall pesticide use in 2007 relative to 1995 generally resulted in decreased detection frequencies in air and rain; observed concentration ranges were similar between years, however, even though the 1995 sampling site was 500 m from active fields whereas the 2007 sampling site was within 3 m of a field. Mean concentrations of detections were sometimes greater in 2007 than in 1995, but the median values were often lower. Seven compounds in 1995 and 5 in 2007 were detected in ≥50% of both air and rain samples. Atrazine, metolachlor, and propanil were detected in ≥50% of the air and rain samples in both years. Glyphosate and its degradation product, aminomethyl-phosphonic acid (AMPA), were detected in ≥75% of air and rain samples in 2007 but were not measured in 1995. The 1995 seasonal wet depositional flux was dominated by methyl parathion (88%) and was >4.5 times the 2007 flux. Total herbicide flux in 2007 was slightly greater than in 1995 and was dominated by glyphosate. Malathion, methyl parathion, and degradation products made up most of the 2007 nonherbicide flux.

Pesticides in Mississippi air and rain: a comparison between 1995 and 2007.

PubMed

Majewski, Michael S; Coupe, Richard H; Foreman, William T; Capel, Paul D

2014-06-01

A variety of current-use pesticides were determined in weekly composite air and rain samples collected during the 1995 and 2007 growing seasons in the Mississippi Delta (MS, USA) agricultural region. Similar sampling and analytical methods allowed for direct comparison of results. Decreased overall pesticide use in 2007 relative to 1995 generally resulted in decreased detection frequencies in air and rain; observed concentration ranges were similar between years, however, even though the 1995 sampling site was 500 m from active fields whereas the 2007 sampling site was within 3 m of a field. Mean concentrations of detections were sometimes greater in 2007 than in 1995, but the median values were often lower. Seven compounds in 1995 and 5 in 2007 were detected in ≥50% of both air and rain samples. Atrazine, metolachlor, and propanil were detected in ≥50% of the air and rain samples in both years. Glyphosate and its degradation product, aminomethyl-phosphonic acid (AMPA), were detected in ≥75% of air and rain samples in 2007 but were not measured in 1995. The 1995 seasonal wet depositional flux was dominated by methyl parathion (88%) and was >4.5 times the 2007 flux. Total herbicide flux in 2007 was slightly greater than in 1995 and was dominated by glyphosate. Malathion, methyl parathion, and degradation products made up most of the 2007 nonherbicide flux. © 2014 SETAC.

ASSESSMENT OF VAPOR INTRUSION USING INDOOR AND SUB-SLAB AIR SAMPLING

EPA Science Inventory

The objective of this investigation was to develop a method for evaluating vapor intrusion using indoor and sub-slab air measurement and at the same time directly assist EPA’s New England Regional Office in evaluating vapor intrusion in 15 homes and one business near the former R...

Novel sample preparation technique with needle-type micro-extraction device for volatile organic compounds in indoor air samples.

PubMed

Ueta, Ikuo; Mizuguchi, Ayako; Fujimura, Koji; Kawakubo, Susumu; Saito, Yoshihiro

2012-10-09

A novel needle-type sample preparation device was developed for the effective preconcentration of volatile organic compounds (VOCs) in indoor air before gas chromatography-mass spectrometry (GC-MS) analysis. To develop a device for extracting a wide range of VOCs typically found in indoor air, several types of particulate sorbents were tested as the extraction medium in the needle-type extraction device. To determine the content of these VOCs, air samples were collected for 30min with the packed sorbent(s) in the extraction needle, and the extracted VOCs were thermally desorbed in a GC injection port by the direct insertion of the needle. A double-bed sorbent consisting of a needle packed with divinylbenzene and activated carbon particles exhibited excellent extraction and desorption performance and adequate extraction capacity for all the investigated VOCs. The results also clearly demonstrated that the proposed sample preparation method is a more rapid, simpler extraction/desorption technique than traditional sample preparation methods. Copyright © 2012 Elsevier B.V. All rights reserved.

Indoor air quality investigation and health risk assessment at correctional institutions.

PubMed

Ofungwu, Joseph

2005-04-01

A comprehensive indoor air-quality (IAQ) investigation was conducted at a state correctional facility in New Jersey, USA with a lengthy history of IAQ problems. The IAQ investigation comprised preliminary indoor air screening using direct readout instrumentation, indoor air/surface wipe sampling and laboratory analysis, as well as a heating, ventilation, and air-conditioning system evaluation, and a building envelope survey. In addition to air sampling, a human health risk assessment was performed to evaluate the potential for exposure to site-related air contaminants with respect to the inmate and worker populations. The risk assessment results for the prison facility indicated the potential for significant health risks for the inmate population, possibly reflecting the effects of their confinement and extended exposure to indoor air contaminants, as compared to the prison guard and worker population. Based on the results of the risk assessment, several mitigation measures are recommended to minimize prison population health risks and improve indoor air quality at prison facilities.

Contribution of Vegetation to the Microbial Composition of Nearby Outdoor Air

PubMed Central

Adams, Rachel I.

2016-01-01

ABSTRACT Given that epiphytic microbes are often found in large population sizes on plants, we tested the hypothesis that plants are quantitatively important local sources of airborne microorganisms. The abundance of microbial communities, determined by quantifying bacterial 16S RNA genes and the fungal internal transcribed spacer (ITS) region, in air collected directly above vegetation was 2- to 10-fold higher than that in air collected simultaneously in an adjacent nonvegetated area 50 m upwind. Nonmetric multidimensional scaling revealed that the composition of airborne bacteria in upwind air samples grouped separately from that of downwind air samples, while communities on plants and downwind air could not be distinguished. In contrast, fungal taxa in air samples were more similar to each other than to the fungal epiphytes. A source-tracking algorithm revealed that up to 50% of airborne bacteria in downwind air samples were presumably of local plant origin. The difference in the proportional abundances of a given operational taxonomic unit (OTU) between downwind and upwind air when regressed against the proportional representation of this OTU on the plant yielded a positive slope for both bacteria and fungi, indicating that those taxa that were most abundant on plants proportionally contributed more to downwind air. Epiphytic fungi were less of a determinant of the microbiological distinctiveness of downwind air and upwind air than epiphytic bacteria. Emigration of epiphytic bacteria and, to a lesser extent, fungi, from plants can thus influence the microbial composition of nearby air, a finding that has important implications for surrounding ecosystems, including the built environment into which outdoor air can penetrate. IMPORTANCE This paper addresses the poorly understood role of bacterial and fungal epiphytes, the inhabitants of the aboveground plant parts, in the composition of airborne microbes in outdoor air. It is widely held that epiphytes contribute to atmospheric microbial assemblages, but much of what we know is limited to qualitative assessments. Elucidating the sources of microbes in outdoor air can inform basic biological processes seen in airborne communities (e.g., dispersal and biogeographical patterns). Furthermore, given the considerable contribution of outdoor air to microbial communities found within indoor environments, the understanding of plants as sources of airborne microbes in outdoor air might contribute to our understanding of indoor air quality. With an experimental design developed to minimize the likelihood of other-than-local plant sources contributing to the composition of airborne microbes, we provide direct evidence that plants are quantitatively important local sources of airborne microorganisms, with implications for the surrounding ecosystems. PMID:27107117

Contribution of Vegetation to the Microbial Composition of Nearby Outdoor Air.

PubMed

Lymperopoulou, Despoina S; Adams, Rachel I; Lindow, Steven E

2016-07-01

Given that epiphytic microbes are often found in large population sizes on plants, we tested the hypothesis that plants are quantitatively important local sources of airborne microorganisms. The abundance of microbial communities, determined by quantifying bacterial 16S RNA genes and the fungal internal transcribed spacer (ITS) region, in air collected directly above vegetation was 2- to 10-fold higher than that in air collected simultaneously in an adjacent nonvegetated area 50 m upwind. Nonmetric multidimensional scaling revealed that the composition of airborne bacteria in upwind air samples grouped separately from that of downwind air samples, while communities on plants and downwind air could not be distinguished. In contrast, fungal taxa in air samples were more similar to each other than to the fungal epiphytes. A source-tracking algorithm revealed that up to 50% of airborne bacteria in downwind air samples were presumably of local plant origin. The difference in the proportional abundances of a given operational taxonomic unit (OTU) between downwind and upwind air when regressed against the proportional representation of this OTU on the plant yielded a positive slope for both bacteria and fungi, indicating that those taxa that were most abundant on plants proportionally contributed more to downwind air. Epiphytic fungi were less of a determinant of the microbiological distinctiveness of downwind air and upwind air than epiphytic bacteria. Emigration of epiphytic bacteria and, to a lesser extent, fungi, from plants can thus influence the microbial composition of nearby air, a finding that has important implications for surrounding ecosystems, including the built environment into which outdoor air can penetrate. This paper addresses the poorly understood role of bacterial and fungal epiphytes, the inhabitants of the aboveground plant parts, in the composition of airborne microbes in outdoor air. It is widely held that epiphytes contribute to atmospheric microbial assemblages, but much of what we know is limited to qualitative assessments. Elucidating the sources of microbes in outdoor air can inform basic biological processes seen in airborne communities (e.g., dispersal and biogeographical patterns). Furthermore, given the considerable contribution of outdoor air to microbial communities found within indoor environments, the understanding of plants as sources of airborne microbes in outdoor air might contribute to our understanding of indoor air quality. With an experimental design developed to minimize the likelihood of other-than-local plant sources contributing to the composition of airborne microbes, we provide direct evidence that plants are quantitatively important local sources of airborne microorganisms, with implications for the surrounding ecosystems. Copyright © 2016 Lymperopoulou et al.

Environmental survey to assess viral contamination of air and surfaces in hospital settings.

PubMed

Carducci, A; Verani, M; Lombardi, R; Casini, B; Privitera, G

2011-03-01

The presence of pathogenic viruses in healthcare settings represents a serious risk for both staff and patients. Direct viral detection in the environment poses significant technical problems and the indirect indicators currently in use suffer from serious limitations. The aim of this study was to monitor surfaces and air in hospital settings to reveal the presence of hepatitis C virus, human adenovirus, norovirus, human rotavirus and torque teno virus by nucleic acid assays, in parallel with measurements of total bacterial count and haemoglobin presence. In total, 114 surface and 62 air samples were collected. Bacterial contamination was very low (<1 cfu/cm(2)) on surfaces, whereas the 'medium' detected value in air was 282 cfu/m(3). Overall, 19 (16.7%) surface samples tested positive for viral nucleic acids: one for norovirus, one for human adenovirus and 17 (14.9%) for torque teno virus (TTV). Only this latter virus was directly detected in 10 air samples (16.1%). Haemoglobin was found on two surfaces. No relationship was found between viral, biochemical or bacterial indicators. The data obtained confirm the difficulty of assessing viral contamination using bacterial indicators. The frequent detection of TTV suggests its possible use as an indicator for general viral contamination of the environment. Copyright © 2010 The Hospital Infection Society. Published by Elsevier Ltd. All rights reserved.

Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

PubMed

Lee, Kil Yong; Burnett, William C

A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H 2 O and BigBottle RAD-H 2 O. The results have shown good agreement between this method and the standard methods.

Phytoforensics—Using trees to find contamination

USGS Publications Warehouse

Wilson, Jordan L.

2017-09-28

The water we drink, air we breathe, and soil we come into contact with have the potential to adversely affect our health because of contaminants in the environment. Environmental samples can characterize the extent of potential contamination, but traditional methods for collecting water, air, and soil samples below the ground (for example, well drilling or direct-push soil sampling) are expensive and time consuming. Trees are closely connected to the subsurface and sampling tree trunks can indicate subsurface pollutants, a process called phytoforensics. Scientists at the Missouri Water Science Center were among the first to use phytoforensics to screen sites for contamination before using traditional sampling methods, to guide additional sampling, and to show the large cost savings associated with tree sampling compared to traditional methods. 

Use Of The Operational Air Quality Monitor (AQM) For In-Flight Water Testing Project

NASA Technical Reports Server (NTRS)

Macatangay, Ariel

2014-01-01

A primary requirement for manned spaceflight is Environmental Health which ensures air and water contaminants, acoustic profiles, microbial flora, and radiation exposures within the cabin are maintained to levels needed for crew health and for vehicle system functionality. The reliance on ground analyses of returned samples is a limitation in the current environmental monitoring strategy that will prevent future Exploration missions beyond low-Earth orbit. This proposal attempts to address this shortcoming by advancing in-flight analyses of water and air. Ground analysis of in-flight, air and water samples typically employ vapor-phase analysis by gas chromatography-mass spectrometry (GC-MS) to identify and quantify organic compounds present in the samples. We envision the use of newly-developed direct ionization approaches as the most viable avenue leading towards an integrated analytical platform for the monitoring of water, air, and, potentially bio-samples in the cabin environment. Development of an in-flight instrument capable of analyzing air and water samples would be the logical next step to meeting the environmental monitoring needs of Exploration missions. Currently, the Air Quality Monitor (AQM) on-board ISS provides this specific information for a number of target compounds in the air. However, there is a significant subset of common target compounds between air and water. Naturally, the following question arises, "Can the AQM be used for both air and water quality monitoring?" Previous directorate-level IR&D funding led to the development of a water sample introduction method for mass spectrometry using electrothermal vaporization (ETV). This project will focus on the integration of the ETV with a ground-based AQM. The capabilities of this integrated platform will be evaluated using a subset of toxicologically important compounds.

Environmental continuous air monitor inlet with combined preseparator and virtual impactor

DOEpatents

Rodgers, John C [Santa Fe, NM

2007-06-19

An inlet for an environmental air monitor is described wherein a pre-separator interfaces with ambient environment air and removes debris and insects commonly associated with high wind outdoors and a deflector plate in communication with incoming air from the pre-separator stage, that directs the air radially and downward uniformly into a plurality of accelerator jets located in a manifold of a virtual impactor, the manifold being cylindrical and having a top, a base, and a wall, with the plurality of accelerator jets being located in the top of the manifold and receiving the directed air and accelerating directed air, thereby creating jets of air penetrating into the manifold, where a major flow is deflected to the walls of the manifold and extracted through ports in the walls. A plurality of receiver nozzles are located in the base of the manifold coaxial with the accelerator jets, and a plurality of matching flow restrictor elements are located in the plurality of receiver nozzles for balancing and equalizing the total minor flow among all the plurality of receiver nozzles, through which a lower, fractional flow extracts large particle constituents of the air for collection on a sample filter after passing through the plurality of receiver nozzles and the plurality of matching flow restrictor elements.

Air filtration systems and restrictive access conditions improve indoor air quality in clinical units: Penicillium as a general indicator of hospital indoor fungal levels.

PubMed

Araujo, Ricardo; Cabral, João Paulo; Rodrigues, Acácio Gonçalves

2008-03-01

High-efficiency particulate air (HEPA) filters do not completely prevent nosocomial fungal infections. The first aim of this study was to evaluate the impact of different filters and access conditions upon airborne fungi in hospital facilities. Additionally, this study identified fungal indicators of indoor air concentrations. Eighteen rooms and wards equipped with different air filter systems, and access conditions were sampled weekly, during 16 weeks. Tap water samples were simultaneously collected. The overall mean concentration of atmospheric fungi for all wards was 100 colony forming units/m(3). We found a direct proportionality between the levels of the different fungi in the studied atmospheres. Wards with HEPA filters at positive air flow yielded lower fungal levels. Also, the existence of an anteroom and the use of protective clothes were associated to the lowest fungal levels. Principal component analysis showed that penicillia afforded the best separation between wards' air fungal levels. Fungal strains were rarely recovered from tap water samples. In addition to air filtration systems, some access conditions to hospital units, like presence of anteroom and use of protective clothes, may prevent high fungal air load. Penicillia can be used as a general indicator of indoor air fungal levels at Hospital S. João.

Assessment of depleted uranium in South-Western Iran.

PubMed

Yousefi, Hossein; Najafi, Abdullah

2013-10-01

Depleted uranium (DU) has been used in a number of conflicts most notably during the Gulf War in Iraq and existence of it has been reported in Kuwait by IAEA experts. Due to heavy sand storms prevailing into the direction to South West of Iran transporting sand originating from Iraq, the probability that DU could be moved is considered high. Therefore it was decided to take some air and soil samples near border line and some nearest cities. The study was focused on finding DU in air and soil of these south-west provinces. 22 air samples and 20 soil samples were collected and analyzed on their contents of uranium isotopes by alpha, beta and gamma spectrometry. The air and soil samples have been measured by use of an alpha-beta counter and by a gamma spectrometer, respectively. Results showed that there is no radiation impact from DU and so no DU has been transported via sand storms since all results were obtained below the detection limit. Copyright © 2013 Elsevier Ltd. All rights reserved.

Air Quality and Road Emission Results for Fort Stewart, Georgia

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

Kirkham, Randy R.; Driver, Crystal J.; Chamness, Mickie A.

2004-02-02

The Directorate of Public Works Environmental & Natural Resources Division (Fort Stewart /Hunter Army Airfield) contracted with the Pacific Northwest National Laboratory (PNNL) to monitor particulate matter (PM) concentrations on Fort Stewart, Georgia. The purpose of this investigation was to establish a PM sampling network using monitoring equipment typically used in U.S. Environmental Protection Agency (EPA) ''saturation sampling'', to determine air quality on the installation. In this initial study, the emphasis was on training-generated PM, not receptor PM loading. The majority of PM samples were 24-hr filter-based samples with sampling frequency ranging from every other day, to once every sixmore » days synchronized with the EPA 6th day national sampling schedule. Eight measurement sites were established and used to determine spatial variability in PM concentrations and evaluate whether fluctuations in PM appear to result from training activities and forest management practices on the installation. Data collected to date indicate the average installation PM2.5 concentration is lower than that of nearby urban Savannah, Georgia. At three sites near the installation perimeter, analyses to segregate PM concentrations by direction of air flow across the installation boundary indicate that air (below 80 ft) leaving the installation contains less PM2.5 than that entering the installation. This is reinforced by the observation that air near the ground is cleaner on average than the air at the top of the canopy.« less

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.

Collection and Analysis of Firn Air from the South Pole, 2001

NASA Astrophysics Data System (ADS)

Butler, J. H.; Montzka, S. A.; Battle, M.; Clarke, A. D.; Mondeel, D. J.; Lind, J. A.; Hall, B. D.; Elkins, J. W.

2001-12-01

In January 2001, we collected an archive of 20th century air from the firn (snowpack) at the South Pole. Samples were collected into separate pairs of 3L glass flasks for measurements of O2/N2 (Bowdoin/Princeton) and carbon cycle gases (CMDL); individual 3L stainless steel and glass flasks for measurements of halocarbons, N2O, SF6, and COS; large (33L) stainless steel canisters for maintaining an archive of air for future analyses; and a few canisters each for measurement of 14CH4 (NIWA/CSIRO) and very low-level analyses of SF6 (SIO). Although it was hoped to obtain air dating back to the turn of the century, the analyses suggest that the earliest date was 1925 for CO2 and the mid- to late teens for heavier gases such as methyl bromide or methyl chloride. This talk will compare the analyses of halocarbons in these recently collected samples to those of air in flasks sampled at the South Pole in 1995. We also will present some results for compounds not measured in the 1995 South Pole samples owing to a paucity of air. Measurements made of the same gases in the firn air at both ends of this six-year interval, along with real-time atmospheric measurements of the same gases, are useful in evaluating assumptions about diffusion in the firn and may allow for the direct calculation of diffusion coefficients at low temperatures. This, in turn, would improve age estimates for firn air samples. New measurements will add to our existing histories established for the 20th century from analyses of firn air samples collected in both Greenland and Antarctica.

Spatial and seasonal distributions of polychlorinated dibenzo-p-dioxins and dibenzofurans and polychlorinated biphenyls around a municipal solid waste incinerator, determined using polyurethane foam passive air samplers.

PubMed

Gao, Lirong; Zhang, Qin; Liu, Lidan; Li, Changliang; Wang, Yiwen

2014-11-01

Twenty-six ambient air samples were collected around a municipal solid waste incinerator (MSWI) in the summer and winter using polyurethane foam passive air samplers, and analyzed to assess the spatial and seasonal distributions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). Three stack gas samples were also collected and analyzed to determine PCDD/F (971 pg m(-3) in average) and PCB (2,671 pg m(-3) in average) emissions from the MSWI and to help identify the sources of the pollutants in the ambient air. The total PCDD/F concentrations in the ambient air samples were lower in the summer (472-1,223 fg m(-3)) than the winter (561-3913 fg m(-3)). In contrast, the atmospheric total PCB concentrations were higher in the summer (716-4,902 fg m(-3)) than the winter (489-2,298 fg m(-3)). Principal component analysis showed that, besides emissions from the MSWI, the domestic burning of coal and wood also contributed to the presence of PCDD/Fs and PCBs in the ambient air. The PCDD/F and PCB spatial distributions were analyzed using ordinary Kriging Interpolation and limited effect was found to be caused by emissions from the MSWI. Higher PCDD/F and PCB concentrations were observed downwind of the MSWI than in the other directions, but the highest concentrations were not to be found in the direction with the greatest wind frequency which might be caused by emissions from domestic coal and wood burning. We used a systemic method including sampling and data analysis method which can provide pioneering information for characterizing risks and assessing uncertainty of PCDD/Fs and PCBs in the ambient air around MSWIs in China. Copyright © 2014 Elsevier Ltd. All rights reserved.

An Inexpensive Autosampler to Maximize Throughput for an Ion Source that Samples Surfaces in Open Air

EPA Science Inventory

An autosampler was built to pull cotton swab heads mounted into a 3-foot long, square Al rod in ambient air through the He ionizing beam of a Direct Analysis in Real Time (DART) ion source interfaced to an orthogonal acceleration, time-of-flight mass spectrometer. The cost of th...

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

Quantitative filter forensics for indoor particle sampling.

PubMed

Haaland, D; Siegel, J A

2017-03-01

Filter forensics is a promising indoor air investigation technique involving the analysis of dust which has collected on filters in central forced-air heating, ventilation, and air conditioning (HVAC) or portable systems to determine the presence of indoor particle-bound contaminants. In this study, we summarize past filter forensics research to explore what it reveals about the sampling technique and the indoor environment. There are 60 investigations in the literature that have used this sampling technique for a variety of biotic and abiotic contaminants. Many studies identified differences between contaminant concentrations in different buildings using this technique. Based on this literature review, we identified a lack of quantification as a gap in the past literature. Accordingly, we propose an approach to quantitatively link contaminants extracted from HVAC filter dust to time-averaged integrated air concentrations. This quantitative filter forensics approach has great potential to measure indoor air concentrations of a wide variety of particle-bound contaminants. Future studies directly comparing quantitative filter forensics to alternative sampling techniques are required to fully assess this approach, but analysis of past research suggests the enormous possibility of this approach. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Longitudinal Study of the Contamination of Air and of Soil Surfaces in the Vicinity of Pig Barns by Livestock-Associated Methicillin-Resistant Staphylococcus aureus

PubMed Central

Friese, Anika; Klees, Sylvia; Tenhagen, Bernd A.; Fetsch, Alexandra; Rösler, Uwe; Hartung, Jörg

2012-01-01

During 1 year, samples were taken on 4 days, one sample in each season, from pigs, the floor, and the air inside pig barns and from the ambient air and soil at different distances outside six commercial livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA)-positive pig barns in the north and east of Germany. LA-MRSA was isolated from animals, floor, and air samples in the barn, showing a range of airborne LA-MRSA between 6 and 3,619 CFU/m3 (median, 151 CFU/m3). Downwind of the barns, LA-MRSA was detected in low concentrations (11 to 14 CFU/m3) at distances of 50 and 150 m; all upwind air samples were negative. In contrast, LA-MRSA was found on soil surfaces at distances of 50, 150, and 300 m downwind from all barns, but no statistical differences could be observed between the proportions of positive soil surface samples at the three different distances. Upwind of the barns, positive soil surface samples were found only sporadically. Significantly more positive LA-MRSA samples were found in summer than in the other seasons both in air and soil samples upwind and downwind of the pig barns. spa typing was used to confirm the identity of LA-MRSA types found inside and outside the barns. The results show that there is regular airborne LA-MRSA transmission and deposition, which are strongly influenced by wind direction and season, of up to at least 300 m around positive pig barns. The described boot sampling method seems suitable to characterize the contamination of the vicinity of LA-MRSA-positive pig barns by the airborne route. PMID:22685139

Longitudinal study of the contamination of air and of soil surfaces in the vicinity of pig barns by livestock-associated methicillin-resistant Staphylococcus aureus.

PubMed

Schulz, Jochen; Friese, Anika; Klees, Sylvia; Tenhagen, Bernd A; Fetsch, Alexandra; Rösler, Uwe; Hartung, Jörg

2012-08-01

During 1 year, samples were taken on 4 days, one sample in each season, from pigs, the floor, and the air inside pig barns and from the ambient air and soil at different distances outside six commercial livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA)-positive pig barns in the north and east of Germany. LA-MRSA was isolated from animals, floor, and air samples in the barn, showing a range of airborne LA-MRSA between 6 and 3,619 CFU/m(3) (median, 151 CFU/m(3)). Downwind of the barns, LA-MRSA was detected in low concentrations (11 to 14 CFU/m(3)) at distances of 50 and 150 m; all upwind air samples were negative. In contrast, LA-MRSA was found on soil surfaces at distances of 50, 150, and 300 m downwind from all barns, but no statistical differences could be observed between the proportions of positive soil surface samples at the three different distances. Upwind of the barns, positive soil surface samples were found only sporadically. Significantly more positive LA-MRSA samples were found in summer than in the other seasons both in air and soil samples upwind and downwind of the pig barns. spa typing was used to confirm the identity of LA-MRSA types found inside and outside the barns. The results show that there is regular airborne LA-MRSA transmission and deposition, which are strongly influenced by wind direction and season, of up to at least 300 m around positive pig barns. The described boot sampling method seems suitable to characterize the contamination of the vicinity of LA-MRSA-positive pig barns by the airborne route.

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.

Effects of packaging environments on free radicals in gamma-irradiated UHMWPE resin powder blend with vitamin E.

PubMed

Ridley, M D; Jahan, M S

2009-03-15

Ultra-high molecular weight polyethylene (UHMWPE) powder (GUR 1020) was blended with high concentration (20%) of vitamin E (alpha-Tocopherol (alpha-T)) for direct detection of alpha-T radicals in presence of PE radicals. Samples were gamma-irradiated in sealed packages filled with N(2), or in open air. Free radicals were measured in open air environment for 71 days using electron spin resonance (ESR) technique. When irradiated in air, both alpha-T and alpha-T-resin produced identical ESR signals characteristics of tochopheroxyl radicals (alpha-T-O(*)), suggesting that PE radicals are quenched by alpha-T. There was no indication of growth of oxygen-induced radicals (OIR) either. However, when alpha-T-resin was irradiated in N(2), presence of both PE and alpha-T radicals were evident in the ESR spectra. And, OIR were produced by the same samples when they were subsequently exposed to air (for 71 days). Oxidation data recorded 85 days after postirradiation aging in air using Fourier transform infra-red (FTIR) spectroscopy, however, did not show any measurable difference between samples irradiated in N(2) and air.

Detection limits of Legionella pneumophila in environmental samples after co-culture with Acanthamoeba polyphaga

PubMed Central

2013-01-01

Background The efficiency of recovery and the detection limit of Legionella after co-culture with Acanthamoeba polyphaga are not known and so far no investigations have been carried out to determine the efficiency of the recovery of Legionella spp. by co-culture and compare it with that of conventional culturing methods. This study aimed to assess the detection limits of co-culture compared to culture for Legionella pneumophila in compost and air samples. Compost and air samples were spiked with known concentrations of L. pneumophila. Direct culturing and co-culture with amoebae were used in parallel to isolate L. pneumophila and recovery standard curves for both methods were produced for each sample. Results The co-culture proved to be more sensitive than the reference method, detecting 102-103 L. pneumophila cells in 1 g of spiked compost or 1 m3 of spiked air, as compared to 105-106 cells in 1 g of spiked compost and 1 m3 of spiked air. Conclusions Co-culture with amoebae is a useful, sensitive and reliable technique to enrich L. pneumophila in environmental samples that contain only low amounts of bacterial cells. PMID:23442526

Different Types of Heater-Cooler Units and Their Risk of Transmission of Mycobacterium chimaera During Open-Heart Surgery: Clues From Device Design.

PubMed

Kuehl, Richard; Banderet, Florian; Egli, Adrian; Keller, Peter M; Frei, Reno; Döbele, Thomas; Eckstein, Friedrich; Widmer, Andreas F

2018-05-28

OBJECTIVEWorldwide, Mycobacterium chimaera infections have been linked to contaminated aerosols from heater-cooler units (HCUs) during open-heart surgery. These infections have mainly been associated with the 3T HCU (LivaNova, formerly Sorin). The reasons for this and the risk of transmission from other HCUs have not been systematically assessed.DESIGNProspective observational study.SETTINGUniversity Hospital Basel, Switzerland.METHODSContinuous microbiological surveillance of 3 types of HCUs in use (3T from LivaNova/Sorin and HCU30 and HCU40 from Maquet) was initiated in June 2014, coupled with an epidemiologic workup. Monthly water and air samples were taken. Construction design was analyzed, and exhausted airflow was measured.RESULTS Mycobacterium chimaera grew in 8 of 12 water samples (66%) and 22 of 24 air samples (91%) of initial 3T HCUs in use, and in 2 of 83 water samples (2%) and 0 of 41 (0%) air samples of new replacement 3T HCUs. Moreover, 7 of 12 water samples (58%) and 0 of 4 (0%) air samples from the HCU30 were positive, and 0 of 64 (0%) water samples and 0 of 50 (0%) air samples from the HCU40 were positive. We identified 4 relevant differences in HCU design compared to the 3T: air flow direction, location of cooling ventilators, continuous cooling of the water tank at 4°C, and an electronic alarm in the HCU40 reminding the user of the next disinfection cycle.CONCLUSIONSAll infected patients were associated with a 3T HCU. The individual HCU design may explain the different risk of disseminating M. chimaera into the air of the operating room. These observations can help the construction of improved devices to ensure patient safety during cardiac surgery.Infect Control Hosp Epidemiol 2018;1-7.

Measurements of dermal uptake of nicotine directly from air and clothing.

PubMed

Bekö, G; Morrison, G; Weschler, C J; Koch, H M; Pälmke, C; Salthammer, T; Schripp, T; Toftum, J; Clausen, G

2017-03-01

In this preliminary study, we have investigated whether dermal uptake of nicotine directly from air or indirectly from clothing can be a meaningful exposure pathway. Two participants wearing only shorts and a third participant wearing clean cotton clothes were exposed to environmental tobacco smoke (ETS), generated by mechanically "smoking" cigarettes, for three hours in a chamber while breathing clean air from head-enveloping hoods. The average nicotine concentration (420 μg/m 3 ) was comparable to the highest levels reported for smoking sections of pubs. Urine samples were collected immediately before exposure and 60 hour post-exposure for bare-skinned participants. For the clothed participant, post-exposure urine samples were collected for 24 hour. This participant then entered the chamber for another three-hour exposure wearing a hood and clothes, including a shirt that had been exposed for five days to elevated nicotine levels. The urine samples were analyzed for nicotine and two metabolites-cotinine and 3OH-cotinine. Peak urinary cotinine and 3OH-cotinine concentrations for the bare-skinned participants were comparable to levels measured among non-smokers in hospitality environments before smoking bans. The amount of dermally absorbed nicotine for each bare-skinned participant was conservatively estimated at 570 μg, but may have been larger. For the participant wearing clean clothes, uptake was ~20 μg, and while wearing a shirt previously exposed to nicotine, uptake was ~80 μg. This study demonstrates meaningful dermal uptake of nicotine directly from air or from nicotine-exposed clothes. The findings are especially relevant for children in homes with smoking or vaping. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Model-measurement comparison of ammonia bi-directional air-surface exchange fluxes over agricultural fields

EPA Science Inventory

Modeling of the bi-directional fluxes (BDFs) of ammonia (NH3) over fertilized soybean and corn canopies was evaluated for three intensive sampling periods: the first, during the summer of 2002 in Warsaw, North Carolina (NC), USA; and the second and third during the summer of 2007...

Quantification and spread of Pneumocystis jirovecii in the surrounding air of patients with Pneumocystis pneumonia.

PubMed

Choukri, Firas; Menotti, Jean; Sarfati, Claudine; Lucet, Jean-Christophe; Nevez, Gilles; Garin, Yves J F; Derouin, Francis; Totet, Anne

2010-08-01

Airborne transmission of Pneumocystis has been demonstrated in animal models and is highly probable in humans. However, information concerning burdens of Pneumocystis jirovecii (human-derived Pneumocystis) in exhaled air from infected patients is lacking. Our objective is to evaluate P. jirovecii air diffusion in patients with Pneumocystis pneumonia. Patients admitted with Pneumocystis pneumonia were prospectively enrolled from 9 January 2008 to 21 July 2009. Air samples (1.5 m(3)) were collected on liquid medium with a commercial sampler at 1-, 3-, 5-, and 8-m distances from patients' heads. Air control samples were collected away from Pneumocystis pneumonia patient wards and outdoors. Samples were examined for P. jirovecii detection and quantification using a real-time polymerase chain reaction assay targeting the mitochondrial large subunit ribosomal RNA gene. Forty patients were diagnosed as having Pneumocystis pneumonia. Air sampling was performed in the environment for 19 of them. At a 1-m distance from patients' heads, P. jirovecii DNA was detected in 15 (79.8%) of 19 patients, with fungal burdens ranging from 7.5 X 10³ to 4.5 X 10⁶ gene copies/m(3). These levels decreased with distance from the patients (P < .002). Nevertheless, 4 (33.3%) of the 12 samples taken at 8 m, in the corridor adjacent to their room, were still positive. Forty control samples were collected and remained negative. This study provides the first quantitative data on the spread of P. jirovecii in exhaled air from infected patients. It sustains the risk of P. jirovecii direct transmission in close contact with patients with Pneumocystis pneumonia and leads the way for initiating a quantitative risk assessment for airborne transmission of P. jirovecii.

Immunological techniques as tools to characterize the subsurface microbial community at a trichloroethylene contaminated site

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

Fliermans, C.B.; Dougherty, J.M.; Franck, M.M.

Effective in situ bioremediation strategies require an understanding of the effects pollutants and remediation techniques have on subsurface microbial communities. Therefore, detailed characterization of a site`s microbial communities is important. Subsurface sediment borings and water samples were collected from a trichloroethylene (TCE) contaminated site, before and after horizontal well in situ air stripping and bioventing, as well as during methane injection for stimulation of methane-utilizing microorganisms. Subsamples were processed for heterotrophic plate counts, acridine orange direct counts (AODC), community diversity, direct fluorescent antibodies (DFA) enumeration for several nitrogen-transforming bacteria, and Biolog {reg_sign} evaluation of enzyme activity in collected water samples.more » Plate counts were higher in near-surface depths than in the vadose zone sediment samples. During the in situ air stripping and bioventing, counts increased at or near the saturated zone, remained elevated throughout the aquifer, but did not change significantly after the air stripping. Sporadic increases in plate counts at different depths as well as increased diversity appeared to be linked to differing lithologies. AODCs were orders of magnitude higher than plate counts and remained relatively constant with depth except for slight increases near the surface depths and the capillary fringe. Nitrogen-transforming bacteria, as measured by serospecific DFA, were greatly affected both by the in situ air stripping and the methane injection. Biolog{reg_sign} activity appeared to increase with subsurface stimulation both by air and methane. The complexity of subsurface systems makes the use of selective monitoring tools imperative.« less

Experimental measurement and Monte Carlo assessment of Argon-41 production in a PET cyclotron facility.

PubMed

Infantino, Angelo; Valtieri, Lorenzo; Cicoria, Gianfranco; Pancaldi, Davide; Mostacci, Domiziano; Marengo, Mario

2015-12-01

In a medical cyclotron facility, (41)Ar (t1/2 = 109.34 m) is produced by the activation of air due to the neutron flux during irradiation, according to the (40)Ar(n,γ)(41)Ar reaction; this is particularly relevant in widely diffused high beam current cyclotrons for the production of PET radionuclides. While theoretical estimations of the (41)Ar production have been published, no data are available on direct experimental measurements for a biomedical cyclotron. In this work, we describe a sampling methodology and report the results of an extensive measurement campaign. Furthermore, the experimental results are compared with Monte Carlo simulations performed with the FLUKA code. To measure (41)Ar activity, air samples were taken inside the cyclotron bunker in sealed Marinelli beakers, during the routine production of (18)F with a 16.5 MeV GE-PETtrace cyclotron; this sampling thus reproduces a situation of absence of air changes. Samples analysis was performed in a gamma-ray spectrometry system equipped with HPGe detector. Monte Carlo assessment of the (41)Ar saturation yield was performed directly using the standard FLUKA score RESNUCLE, and off-line by the convolution of neutron fluence with cross section data. The average (41)Ar saturation yield per one liter of air of (41)Ar, measured in gamma-ray spectrometry, resulted to be 3.0 ± 0.6 Bq/µA*dm(3) while simulations gave a result of 6.9 ± 0.3 Bq/µA*dm(3) in the direct assessment and 6.92 ± 0.22 Bq/µA*dm(3) by the convolution neutron fluence-to-cross section. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

High-throughput liquid-absorption air-sampling apparatus and methods

DOEpatents

Zaromb, Solomon

2000-01-01

A portable high-throughput liquid-absorption air sampler [PHTLAAS] has an asymmetric air inlet through which air is drawn upward by a small and light-weight centrifugal fan driven by a direct current motor that can be powered by a battery. The air inlet is so configured as to impart both rotational and downward components of motion to the sampled air near said inlet. The PHTLAAS comprises a glass tube of relatively small size through which air passes at a high rate in a swirling, highly turbulent motion, which facilitates rapid transfer of vapors and particulates to a liquid film covering the inner walls of the tube. The pressure drop through the glass tube is <10 cm of water, usually <5 cm of water. The sampler's collection efficiency is usually >20% for vapors or airborne particulates in the 2-3.mu. range and >50% for particles larger than 4.mu.. In conjunction with various analyzers, the PHTLAAS can serve to monitor a variety of hazardous or illicit airborne substances, such as lead-containing particulates, tritiated water vapor, biological aerosols, or traces of concealed drugs or explosives.

Insights from two industrial hygiene pilot e-cigarette passive vaping studies.

PubMed

Maloney, John C; Thompson, Michael K; Oldham, Michael J; Stiff, Charles L; Lilly, Patrick D; Patskan, George J; Shafer, Kenneth H; Sarkar, Mohamadi A

2016-01-01

While several reports have been published using research methods of estimating exposure risk to e-cigarette vapors in nonusers, only two have directly measured indoor air concentrations from vaping using validated industrial hygiene sampling methodology. Our first study was designed to measure indoor air concentrations of nicotine, menthol, propylene glycol, glycerol, and total particulates during the use of multiple e-cigarettes in a well-characterized room over a period of time. Our second study was a repeat of the first study, and it also evaluated levels of formaldehyde. Measurements were collected using active sampling, near real-time and direct measurement techniques. Air sampling incorporated industrial hygiene sampling methodology using analytical methods established by the National Institute of Occupational Safety and Health and the Occupational Safety and Health Administration. Active samples were collected over a 12-hr period, for 4 days. Background measurements were taken in the same room the day before and the day after vaping. Panelists (n = 185 Study 1; n = 145 Study 2) used menthol and non-menthol MarkTen prototype e-cigarettes. Vaping sessions (six, 1-hr) included 3 prototypes, with total number of puffs ranging from 36-216 per session. Results of the active samples were below the limit of quantitation of the analytical methods. Near real-time data were below the lowest concentration on the established calibration curves. Data from this study indicate that the majority of chemical constituents sampled were below quantifiable levels. Formaldehyde was detected at consistent levels during all sampling periods. These two studies found that indoor vaping of MarkTen prototype e-cigarette does not produce chemical constituents at quantifiable levels or background levels using standard industrial hygiene collection techniques and analytical methods.

Occurrence of Staphylococcus aureus in swine and swine workplace environments on industrial and antibiotic-free hog operations in North Carolina, USA: A One Health pilot study.

PubMed

Davis, Meghan F; Pisanic, Nora; Rhodes, Sarah M; Brown, Alexis; Keller, Haley; Nadimpalli, Maya; Christ, Andrea; Ludwig, Shanna; Ordak, Carly; Spicer, Kristoffer; Love, David C; Larsen, Jesper; Wright, Asher; Blacklin, Sarah; Flowers, Billy; Stewart, Jill; Sexton, Kenneth G; Rule, Ana M; Heaney, Christopher D

2018-05-01

Occupational exposure to swine has been associated with increased Staphylococcus aureus carriage, including antimicrobial-resistant strains, and increased risk of infections. To characterize animal and environmental routes of worker exposure, we optimized methods to identify S. aureus on operations that raise swine in confinement with antibiotics (industrial hog operation: IHO) versus on pasture without antibiotics (antibiotic-free hog operation: AFHO). We associated findings from tested swine and environmental samples with those from personal inhalable air samplers on worker surrogates at one IHO and three AFHOs in North Carolina using a new One Health approach. We determined swine S. aureus carriage status by collecting swab samples from multiple anatomical sites, and we determined environmental positivity for airborne bioaerosols with inhalable and impinger samplers and a single-stage impactor (ambient air) cross-sectionally. All samples were analyzed for S. aureus, and isolates were tested for antimicrobial susceptibility, absence of scn (livestock marker), and spa type. Seventeen of twenty (85%) swine sampled at the one IHO carried S. aureus at >1 anatomical sites compared to none of 30 (0%) swine sampled at the three AFHOs. All S. aureus isolates recovered from IHO swine and air samples were scn negative and spa type t337; almost all isolates (62/63) were multidrug resistant. S. aureus was recovered from eight of 14 (67%) ambient air and two (100%) worker surrogate personal air samples at the one IHO, whereas no S. aureus isolates were recovered from 19 ambient and six personal air samples at the three AFHOs. Personal worker surrogate inhalable sample findings were consistent with both swine and ambient air data, indicating the potential for workplace exposure. IHO swine and the one IHO environment could be a source of potential pathogen exposure to workers, as supported by the detection of multidrug-resistant S. aureus (MDRSA) with livestock-associated spa type t337 among swine, worker surrogate personal air samplers and environmental air samples at the one IHO but none of the three AFHOs sampled in this study. Concurrent sampling of swine, personal swine worker surrogate air, and ambient airborne dust demonstrated that IHO workers may be exposed through both direct (animal contact) and indirect (airborne) routes of transmission. Investigation of the effectiveness of contact and respiratory protections is warranted to prevent IHO worker exposure to multidrug-resistant livestock-associated S. aureus and other pathogens. Copyright © 2017 Elsevier Inc. All rights reserved.

[Hygienic evaluation of the total mutagenic activity of snow samples from Magnitogorsk].

PubMed

Legostaeva, T B; Ingel', F I; Antipanova, N A; Iurchenko, V V; Iuretseva, N A; Kotliar, N N

2010-01-01

The paper gives the results of 4-year monitoring of the total mutagenic activity of snow samples from different Magnitogork areas in a test for induction of dominant lethal mutations (DLM) in the gametes of Drosophila melanogaster. An association was first found between the rate of DLM and the content of some chemical compounds in the ambient air and snow samples; moreover all the substances present in the samples, which had found genotoxic effects, showed a positive correlation with the rate of DLM. Furthermore, direct correlations were first established between the rate of DLM and the air pollution index and morbidity rates in 5-7-year-old children residing in the areas under study. The findings allow the test for induction of dominant lethal mutations (DLM) in the gametes of Drosophila melanogaster to be recommended due to its unique informative and prognostic value for monitoring ambient air pollution and for extensive use in the risk assessment system.

Seasonal and spatial variation of the bacterial mutagenicity of fine organic aerosol in southern california.

PubMed Central

Hannigan, M P; Cass, G R; Lafleur, A L; Busby, W F; Thilly, W G

1996-01-01

The bacterial mutagenicity of a set of 1993 urban particulate air pollution samples is examined using the Salmonella typhimurium TM677 forward mutation assay. Amibent fine particulate samples were collected for 24 hr every sixth day throughout 1993 at four urban sites, including Long Beach, central Los Angeles, Azusa, and Rubidoux, California, and at an upwind background site on San Nicolas Island. Long Beach and central Los Angeles are congested urban areas where air quality is dominated by fresh emissions from air pollution sources; Azuasa and Rubidoux are located farther downwind and receive transported air pollutants plus increased quantities of the products of atmospheric chemical reactions. Fine aerosol samples from Long Beach and Los Angeles show a pronounced seasonal variation in bacterial mutagenicity per cubic meter of- ambient air, with maximum in the winter and a minimum in the summer. The down-wind smog receptor site at Rubidoux shows peak mutagenicity (with postmitochondrial supernatant but no peak without postmitochondrial supernatant) during the September-October periods when direct transport from upwind sources can be expected. At most sites the mutagenicity per microgram of organic carbon from the aerosol is not obviously higher during the summer photochemical smog period than during the colder months. Significant spatial variation in bacterial mutagenicity is observed: mutagenicity per cubic meter of ambient air, on average, is more than an order of magnitude lower at San Nicolas Island than within the urban area. The highest mutagenicity values per microgram of organics supplied to the assay are found at the most congested urban sites at central Los Angeles and Long Beach. The highest annual average values of mutagenicity per cubic meter of air sampled occur at central Los Angeles. These findings stress the importance of proximity to sources of direct emissions of bacterial mutagens and imply that if important mutagen-forming atmospheric reactions occur, they likely occur in the winter and spring seasons as well as the photochemically more active summer and early fall periods. Images Figure 1. Figure 2. Figure 2. Figure 2. Figure 2. Figure 3. Figure 3. Figure 4. Figure 5. Figure 6. PMID:8732954

Evaluation of the radiation hazard for ion-beam analysis with MeV external proton beams (X-IBA)

NASA Astrophysics Data System (ADS)

Hofsäss, Hans

2018-07-01

MeV ion beams which are extracted into air or He atmosphere are used in many labs for proton-induced X-ray emission (PIXE), proton induced gamma ray emission (PIGE) or Rutherford backscattering (RBS) to analyze samples which are difficult or impossible to handle in vacuum. When MeV proton beams are extracted into air through thin Kapton foils or nowadays thin silicon nitride membranes, the protons will interact with air, as well as elements present in the analyzed samples. Typically the range of MeV protons in air is several cm, in Helium atmosphere several 10 cm and in human skin around 100 μm. Besides the severe radiation hazard in case of a direct exposure of skin with protons, there are a manifold of nuclear reactions or inelastic proton scattering processes which may cause activation of air and target materials but also prompt radiation. The radiation hazard associated with the direct and scattered beam, nuclear reaction products and radionuclide production in air have been discussed in a publication by Doyle et al. in 1991 which was used as a reference in several later publications. I have reevaluated the radiation hazards for external proton beams with up to 4.5 MeV using proton reaction cross sections taken from the JANIS book of proton induced cross sections. The radionuclide production in air is about 3 orders of magnitude lower compared to values given in the 1991 publication. Radionuclide production as well as generation of prompt alpha, gamma and neutron radiation in target materials for elements up to molybdenum is also evaluated.

Air-soil exchange of PCBs: levels and temporal variations at two sites in Turkey.

PubMed

Yolsal, Didem; Salihoglu, Güray; Tasdemir, Yücel

2014-03-01

Seasonal distribution of polychlorinated biphenyls (PCBs) at the air-soil intersection was determined for two regions: one with urban characteristics where traffic is dense (BUTAL) and the other representing the coastal zone (Mudanya). Fifty-one air and soil samples were simultaneously collected. Total PCB (Σ82 PCB) levels in the soil samples collected during a 1-year period ranged between 105 and 7,060 pg/g dry matter (dm) (BUTAL) and 110 and 2,320 pg/g dm (Mudanya). Total PCB levels in the gaseous phase were measured to be between 100 and 910 pg/m(3) (BUTAL) and 75 and 1,025 pg/m(3) (Mudanya). Variations in the concentrations were observed depending on the season. Though the PCB concentrations measured in the atmospheres of both regions in the summer months were high, they were found to be lower in winter. However, while soil PCB levels were measured to be high at BUTAL during summer months, they were found to be high during winter months in Mudanya. The direction and amount of the PCB movement were determined by calculating the gaseous phase change fluxes at air-soil intersection. While a general PCB movement from soil to air was found for BUTAL, the PCB movement from air to soil was calculated for the Mudanya region in most of the sampling events. During the warmer seasons PCB movement towards the atmosphere was observed due to evaporation from the soil. With decreases in the temperature, both decreases in the number of PCB congeners occurring in the air and a change in the direction of some congeners were observed, possibly caused by deposition from the atmosphere to the soil. 3-CB and 4-CB congeners were found to be dominant in the atmosphere, and 4-, 5-, and 6-CBs were found to dominate in the surface soils.

Effects of wind direction on coarse and fine particulate matter concentrations in southeast Kansas.

PubMed

Guerra, Sergio A; Lane, Dennis D; Marotz, Glen A; Carter, Ray E; Hohl, Carrie M; Baldauf, Richard W

2006-11-01

Field data for coarse particulate matter ([PM] PM10) and fine particulate matter (PM2.5) were collected at selected sites in Southeast Kansas from March 1999 to October 2000, using portable MiniVol particulate samplers. The purpose was to assess the influence on air quality of four industrial facilities that burn hazardous waste in the area located in the communities of Chanute, Independence, Fredonia, and Coffeyville. Both spatial and temporal variation were observed in the data. Variation because of sampling site was found to be statistically significant for PM10 but not for PM2.5. PM10 concentrations were typically slightly higher at sites located within the four study communities than at background sites. Sampling sites were located north and south of the four targeted sources to provide upwind and downwind monitoring pairs. No statistically significant differences were found between upwind and downwind samples for either PM10 or PM2.5, indicating that the targeted sources did not contribute significantly to PM concentrations. Wind direction can frequently contribute to temporal variation in air pollutant concentrations and was investigated in this study. Sampling days were divided into four classifications: predominantly south winds, predominantly north winds, calm/variable winds, and winds from other directions. The effect of wind direction was found to be statistically significant for both PM10 and PM2.5. For both size ranges, PM concentrations were typically highest on days with predominantly south winds; days with calm/variable winds generally produced higher concentrations than did those with predominantly north winds or those with winds from "other" directions. The significant effect of wind direction suggests that regional sources may exert a large influence on PM concentrations in the area.

Comparison of modern pollen distribution between the northern and southern parts of the South China Sea.

PubMed

Luo, Chuanxiu; Chen, Muhong; Xiang, Rong; Liu, Jianguo; Zhang, Lanlan; Lu, Jun

2015-04-01

The authors conducted a palynological analysis based on different number of air pollen samples for the northern and southern parts of the South China Sea, respectively, in order to give a reference to reconstruct the paleoclimate of the area. (1) Fifteen air pollen samples were collected from the northern part of the South China Sea from August to September 2011, and 13 air pollen samples were collected from the southern part of the South China Sea in December 2011. The pollen types were more abundant in the north than in the south. The total pollen number and concentration in the north was 10 times more than that in the south, which may be because of the sampling season. Airborne pollen types and concentrations have a close relationship with wind direction and distance from the sampling point to the continent. (2) Seventy-four samples were collected from surface sediments in the northern part of the South China Sea in the autumn. Thirty-three samples were collected from surface sediments in the southern part of the South China Sea in the winter. Pollen concentrations in the north were nearly 10 times higher than that in the south. This is because trilete spores are transported by rivers from Hainan Island to the sea and also by the summer monsoon-forced marine current. (3) Ten air pollen samples and 10 surface sediments samples were selected for comparison. The pollen and spores in the air were mainly herbaceous and woody pollen, excluding fern spores, having seasonal pollen characteristics. Pollen in the surface sediments were mainly trilete, Pinus, and herbaceous, and may also show a combination of annual pollen characteristics.

Laser-based measurements of δ13 C and δ2 H methane isotope signatures: precisions competitive with mass spectrometry methods

NASA Astrophysics Data System (ADS)

Yacovitch, Tara; Shorter, Joanne; Nelson, David; Herndon, Scott; Agnese, Mike; McManus, Barry; Zahniser, Mark

2017-04-01

In order to understand how and why methane (CH4 ) concentrations change over time, it is necessary to understand their sources and sinks. Stable isotope measurements of 13 CH4 :12 CH4 and CH3 D:12 CH4 ratios constrain the inventory of these sinks and sources. Current measurements often depend on Isotope Ratio Mass Spectrometry (IRMS), which requires extensive sample preparation including cryogenic separation of methane from air and subsequent conversion to either CO2 or H2 . Here, we detail improvements to a direct-absorption laser spectrometer that enable fast and precise measurements of methane isotope ratios (δ13 C and δ2 H ) of ambient air samples, without such sample preparation. The measurement system consists of a laser-based direct absorption spectrometer configured with a sample manifold for measurement of discrete samples (as opposed to flow-through measurements). Samples are trapped in the instrument using a rapid sample switching technique that compares each flask sample against a monitor tank sample. This approach reduces instrument drift and results in excellent precision. Precisions of 0.054 o/oo for δ13 C and 1.4 o/oo for δ2 H have been achieved (Allan-Werle deviations). These results are obtained in 20 minutes using 4 replicate comparisons to a monitor tank.

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.

The radiocarbon hydroxyl technique

NASA Technical Reports Server (NTRS)

Campbell, Malcolm J.; Sheppard, John C.

1994-01-01

The Radiocarbon Technique depends upon measuring the rate of oxidation of CO in an essentially unperturbed sample of air. The airborne technique is slightly different. Hydroxyl concentrations can be calculated directly; peroxyl concentrations can be obtained by NO doping.

Air contamination measurements for the evaluation of internal dose to workers in nuclear medicine departments

NASA Astrophysics Data System (ADS)

De Massimi, B.; Bianchini, D.; Sarnelli, A.; D'Errico, V.; Marcocci, F.; Mezzenga, E.; Mostacci, D.

2017-11-01

Radionuclides handled in nuclear medicine departments are often characterized by high volatility and short half-life. It is generally difficult to monitor directly the intake of these short-lived radionuclides in hospital staff: this makes measuring air contamination of utmost interest. The aim of the present work is to provide a method for the evaluation of internal doses to workers in nuclear medicine, by means of an air activity sampling detector, to ensure that the limits prescribed by the relevant legislation are respected. A continuous air sampling system measures isotope concentration with a Nal(TI) detector. Energy efficiency of the system was assessed with GEANT4 and with known activities of 18F. Air is sampled in a number of areas of the nuclear medicine department of the IRST-IRCCS hospital (Meldola- Italy). To evaluate committed doses to hospital staff involved (doctors, technicians, nurses) different exposure situations (rooms, times, radionuclides etc) were considered. After estimating the intake, the committed effective dose has been evaluated, for the different radionuclides, using the dose coefficients mandated by the Italian legislation. Error propagation for the estimated intake and personal dose has been evaluated, starting from measurement statistics.

Establishing Lagrangian connections between observations within air masses crossing the Atlantic during the International Consortium for Atmospheric Research on Transport and Transformation experiment

NASA Astrophysics Data System (ADS)

Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D. D.; Reeves, C. E.; Schlager, H.; Atlas, E.; Blake, D. R.; Coe, H.; Crosier, J.; Flocke, F. M.; Holloway, J. S.; Hopkins, J. R.; McQuaid, J.; Purvis, R.; Rappenglück, B.; Singh, H. B.; Watson, N. M.; Whalley, L. K.; Williams, P. I.

2006-12-01

The ITCT-Lagrangian-2K4 (Intercontinental Transport and Chemical Transformation) experiment was conceived with an aim to quantify the effects of photochemistry and mixing on the transformation of air masses in the free troposphere away from emissions. To this end, attempts were made to intercept and sample air masses several times during their journey across the North Atlantic using four aircraft based in New Hampshire (USA), Faial (Azores) and Creil (France). This article begins by describing forecasts from two Lagrangian models that were used to direct the aircraft into target air masses. A novel technique then identifies Lagrangian matches between flight segments. Two independent searches are conducted: for Lagrangian model matches and for pairs of whole air samples with matching hydrocarbon fingerprints. The information is filtered further by searching for matching hydrocarbon samples that are linked by matching trajectories. The quality of these "coincident matches" is assessed using temperature, humidity and tracer observations. The technique pulls out five clear Lagrangian cases covering a variety of situations and these are examined in detail. The matching trajectories and hydrocarbon fingerprints are shown, and the downwind minus upwind differences in tracers are discussed.

Establishing Lagrangian Connections between Observations within Air Masses Crossing the Atlantic during the ICARTT Experiment

NASA Technical Reports Server (NTRS)

Methven, J.; Arnold, S. R.; Stohl, A.; Evans, M. J.; Avery, M.; Law, K.; Lewis, A. C.; Monks, P. S.; Parrish, D.; Reeves, C.;

Fungal burden exposure assessment in podiatry clinics from Ireland.

PubMed

Viegas, Carla; Coggins, Ann Marie; Faria, Tiago; Caetano, Liliana Aranha; Gomes, Anita Quintal; Sabino, Raquel; Verissimo, Cristina; Roberts, Nigel; Watterson, David; MacGilchrist, Claire; Fleming, Gerard T A

2018-03-26

Fungi are amongst the bioaerosols of most importance, as indicated by the growing interest in this field of research. The aim was to characterize the exposure to fungal burden in podiatry clinics using culture-based and molecular methods. Airborne fungi were collected using an impaction air sampler and surface samples were also performed. Fourteen air samples were collected for direct detection of fungal DNA from filamentous fungi and dermatophytes. Overall, 63.6 % of the evening samples and 46 % of the morning samples surpassed the threshold values (150 CFU/m 3 ). Molecular detection, by real time PCR, of the target fungal species/strains (Aspergillus and Stachybotrys species) was negative for all samples collected. Trichophyton rubrum was detected by PCR analysis in one DNA sample collected on day six. Results suggest the use of both culture-based and molecular methodologies are desirable for a complete evaluation of fungal burden in this particular health care setting.

The lung cancer breath signature: a comparative analysis of exhaled breath and air sampled from inside the lungs

NASA Astrophysics Data System (ADS)

Capuano, Rosamaria; Santonico, Marco; Pennazza, Giorgio; Ghezzi, Silvia; Martinelli, Eugenio; Roscioni, Claudio; Lucantoni, Gabriele; Galluccio, Giovanni; Paolesse, Roberto; di Natale, Corrado; D'Amico, Arnaldo

2015-11-01

Results collected in more than 20 years of studies suggest a relationship between the volatile organic compounds exhaled in breath and lung cancer. However, the origin of these compounds is still not completely elucidated. In spite of the simplistic vision that cancerous tissues in lungs directly emit the volatile metabolites into the airways, some papers point out that metabolites are collected by the blood and then exchanged at the air-blood interface in the lung. To shed light on this subject we performed an experiment collecting both the breath and the air inside both the lungs with a modified bronchoscopic probe. The samples were measured with a gas chromatography-mass spectrometer (GC-MS) and an electronic nose. We found that the diagnostic capability of the electronic nose does not depend on the presence of cancer in the sampled lung, reaching in both cases an above 90% correct classification rate between cancer and non-cancer samples. On the other hand, multivariate analysis of GC-MS achieved a correct classification rate between the two lungs of only 76%. GC-MS analysis of breath and air sampled from the lungs demonstrates a substantial preservation of the VOCs pattern from inside the lung to the exhaled breath.

Towards a novel continuous sublimation extraction/laser spectroscopy method for greenhouse gas measurements in the oldest ice

NASA Astrophysics Data System (ADS)

Bereiter, Bernhard; Maechler, Lars; Schmitt, Jochen; Walther, Remo; Tuzson, Béla; Scheidegger, Philipp; Emmenegger, Lukas; Fischer, Hubertus

2017-04-01

Ice cores are unique archives of ancient air providing the only direct record of past greenhouse gases - key in reconstructing the roles of greenhouse gases in past climate changes. The European Partnership in Ice Core Sciences (EuroPICS) plans to drill an ice core extending over 1.5 Ma, nearly doubling the time span of the existing greenhouse record and covering the time period of the Mid Pleistocene Transition. The ice covering the time interval from 1-1.5 Ma is expected to be close to the bedrock and, due to glacial flow, extremely thinned. A 10,000 yr glacial/interglacial transition can be compressed in 1 m of ice. The targeted 100 yr resolution therefore constrains the sample size to 15-30 g containing only 1-2ml STP air. Within the deepSlice project we aim to unlock such atmospheric archives in extremely thinned ice by developing a novel coupled semi-continuous sublimation extraction/laser spectroscopy system. Vacuum sublimation, with an infrared source, has been chosen as extraction method as it allows 100% gas extraction of all gas species from ice without changing the isotopic composition of CO2. In order to reduce ice waste and accelerate sample throughput, we are building a sublimation extraction system that is able to continuously sublimate an ice-core section and subsequently collect discrete full air samples. For the gas analytics, we develop a custom-made mid-infrared laser spectrometer allowing simultaneous measurement of the CO2, CH4 and N2O concentrations as well as the isotopic composition of CO2 on air samples of only 1-2 ml STP. The two systems will be coupled via cryo-trapping of the sample air in dip tubes, followed by expansion of the sample air into the laser spectrometer. Due to the nondestructive laser technique, the air sample can be recollected and reused for further analytics.

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.

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

AirCore-HR: a high-resolution column sampling to enhance the vertical description of CH4 and CO2

NASA Astrophysics Data System (ADS)

Membrive, Olivier; Crevoisier, Cyril; Sweeney, Colm; Danis, François; Hertzog, Albert; Engel, Andreas; Bönisch, Harald; Picon, Laurence

2017-06-01

An original and innovative sampling system called AirCore was presented by NOAA in 2010 Karion et al.(2010). It consists of a long ( > 100 m) and narrow ( < 1 cm) stainless steel tube that can retain a profile of atmospheric air. The captured air sample has then to be analyzed with a gas analyzer for trace mole fraction. In this study, we introduce a new AirCore aiming to improve resolution along the vertical with the objectives to (i) better capture the vertical distribution of CO2 and CH4, (ii) provide a tool to compare AirCores and validate the estimated vertical resolution achieved by AirCores. This (high-resolution) AirCore-HR consists of a 300 m tube, combining 200 m of 0.125 in. (3.175 mm) tube and a 100 m of 0.25 in. (6.35 mm) tube. This new configuration allows us to achieve a vertical resolution of 300 m up to 15 km and better than 500 m up to 22 km (if analysis of the retained sample is performed within 3 h). The AirCore-HR was flown for the first time during the annual StratoScience campaign from CNES in August 2014 from Timmins (Ontario, Canada). High-resolution vertical profiles of CO2 and CH4 up to 25 km were successfully retrieved. These profiles revealed well-defined transport structures in the troposphere (also seen in CAMS-ECMWF high-resolution forecasts of CO2 and CH4 profiles) and captured the decrease of CO2 and CH4 in the stratosphere. The multi-instrument gondola also carried two other low-resolution AirCore-GUF that allowed us to perform direct comparisons and study the underlying processing method used to convert the sample of air to greenhouse gases vertical profiles. In particular, degrading the AirCore-HR derived profiles to the low resolution of AirCore-GUF yields an excellent match between both sets of CH4 profiles and shows a good consistency in terms of vertical structures. This fully validates the theoretical vertical resolution achievable by AirCores. Concerning CO2 although a good agreement is found in terms of vertical structure, the comparison between the various AirCores yields a large and variable bias (up to almost 3 ppm in some parts of the profiles). The reasons of this bias, possibly related to the drying agent used to dry the air, are still being investigated. Finally, the uncertainties associated with the measurements are assessed, yielding an average uncertainty below 3 ppb for CH4 and 0.25 ppm for CO2 with the major source of uncertainty coming from the potential loss of air sample on the ground and the choice of the starting and ending point of the collected air sample inside the tube. In an ideal case where the sample would be fully retained, it would be possible to know precisely the pressure at which air was sampled last and thus to improve the overall uncertainty to about 0.1 ppm for CO2 and 2 ppb for CH4.

Chemical reactivities of ambient air samples in three Southern California communities

PubMed Central

Eiguren-Fernandez, Arantza; Di Stefano, Emma; Schmitz, Debra A.; Guarieiro, Aline Lefol Nani; Salinas, Erika M.; Nasser, Elina; Froines, John R.; Cho, Arthur K.

2015-01-01

The potential adverse health effects of PM2.5 and vapor samples from three communities that neighbor railyards, Commerce (CM), Long Beach (LB), and San Bernardino (SB), were assessed by determination of chemical reactivities attributed to the induction of oxidative stress by air pollutants. The assays used were dithiothreitol (DTT) and dihydrobenzoic acid (DHBA) based procedures for prooxidant content and a glyceraldehyde-3-phosphate dehydrogenase (GAPDH) assay for electrophiles. Prooxidants and electrophiles have been proposed as the reactive chemical species responsible for the induction of oxidative stress by air pollution mixtures. The PM2.5 samples from CM and LB sites showed seasonal differences in reactivities with higher levels in the winter whereas the SB sample differences were reversed. The reactivities in the vapor samples were all very similar, except for the summer SB samples, which contained higher levels of both prooxidants and electrophiles. The results suggest the observed reactivities reflect general geographical differences rather than direct effects of the railyards. Distributional differences in reactivities were also observed with PM2.5 fractions containing most of the prooxidants (74–81%) and the vapor phase most of the electrophiles (82–96%). The high levels of the vapor phase electrophiles and their potential for adverse biological effects point out the importance of the vapor phase in assessing the potential health effects of ambient air. PMID:25947123

Simultaneous determination of hydroquinone, resorcinol, phenol, m-cresol and p-cresol in untreated air samples using spectrofluorimetry and a custom multiple linear regression-successive projection algorithm.

PubMed

Pistonesi, Marcelo F; Di Nezio, María S; Centurión, María E; Lista, Adriana G; Fragoso, Wallace D; Pontes, Márcio J C; Araújo, Mário C U; Band, Beatriz S Fernández

2010-12-15

In this study, a novel, simple, and efficient spectrofluorimetric method to determine directly and simultaneously five phenolic compounds (hydroquinone, resorcinol, phenol, m-cresol and p-cresol) in air samples is presented. For this purpose, variable selection by the successive projections algorithm (SPA) is used in order to obtain simple multiple linear regression (MLR) models based on a small subset of wavelengths. For comparison, partial least square (PLS) regression is also employed in full-spectrum. The concentrations of the calibration matrix ranged from 0.02 to 0.2 mg L(-1) for hydroquinone, from 0.05 to 0.6 mg L(-1) for resorcinol, and from 0.05 to 0.4 mg L(-1) for phenol, m-cresol and p-cresol; incidentally, such ranges are in accordance with the Argentinean environmental legislation. To verify the accuracy of the proposed method a recovery study on real air samples of smoking environment was carried out with satisfactory results (94-104%). The advantage of the proposed method is that it requires only spectrofluorimetric measurements of samples and chemometric modeling for simultaneous determination of five phenols. With it, air is simply sampled and no pre-treatment sample is needed (i.e., separation steps and derivatization reagents are avoided) that means a great saving of time. Copyright © 2010 Elsevier B.V. All rights reserved.

Direct determination of total sulfur in wine using a continuum-source atomic-absorption spectrometer and an air-acetylene flame.

PubMed

Huang, Mao Dong; Becker-Ross, Helmut; Florek, Stefan; Heitmann, Uwe; Okruss, Michael

2005-08-01

Determination of sulfur in wine is an important analytical task, particularly with regard to food safety legislation, wine trade, and oenology. Hitherto existing methods for sulfur determination all have specific drawbacks, for example high cost and time consumption, poor precision or selectivity, or matrix effects. In this paper a new method, with low running costs, is introduced for direct, reliable, rapid, and accurate determination of the total sulfur content of wine samples. The method is based on measurement of the molecular absorption of carbon monosulfide (CS) in an ordinary air-acetylene flame by using a high-resolution continuum-source atomic-absorption spectrometer including a novel high-intensity short-arc xenon lamp. First results for total sulfur concentrations in different wine samples were compared with data from comparative ICP-MS measurements. Very good agreement within a few percent was obtained.

Soil- and groundwater-quality data for petroleum hydrocarbon compounds within Fuels Area C, Ellsworth Air Force Base, South Dakota, 2014

USGS Publications Warehouse

Bender, David A.; Rowe, Barbara L.

2015-01-01

Ellsworth Air Force Base is an Air Combat Command located approximately 10 miles northeast of Rapid City, South Dakota. Ellsworth Air Force Base occupies about 6,000 acres within Meade and Pennington Counties, and includes runways, airfield operations, industrial areas, housing, and recreational facilities. Fuels Area C within Ellsworth Air Force Base is a fuels storage area that is used to support the mission of the base. In fall of 2013, the U.S. Geological Survey began a study in cooperation with the U.S. Air Force, Ellsworth Air Force Base, to estimate groundwater-flow direction, select locations for permanent monitoring wells, and install and sample monitoring wells for petroleum hydrocarbon compounds within Fuels Area C. Nine monitoring wells were installed for the study within Fuels Area C during November 4–7, 2014. Soil core samples were collected during installation of eight of the monitoring wells and analyzed for benzene, toluene, ethylbenzene, total xylenes, naphthalene,m- and p-xylene, o-xylene, and gasoline- and diesel-range organic compounds. Groundwater samples were collected from seven of the nine wells (two of the monitoring wells did not contain enough water to sample or were dry) during November 19–21, 2014, and analyzed for select physical properties, benzene, toluene, ethylbenzene, total xylenes, naphthalene, m- and p-xylene, o-xylene, and gasoline- and diesel-range organic compounds. This report describes the nine monitoring well locations and presents the soil- and groundwater-quality data collected in 2014 for this study.

A review of polychlorinated biphenyls (PCBs) pollution in indoor air environment.

PubMed

Dai, Qizhou; Min, Xia; Weng, Mili

2016-10-01

Polychlorinated biphenyls (PCBs) were widely used in industrial production due to the unique physical and chemical properties. As a kind of persistent organic pollutants, the PCBs would lead to environment pollution and cause serious problems for human health. Thus, they have been banned since the 1980s due to the environment pollution in the past years. Indoor air is the most direct and important environment medium to human beings; thus, the PCBs pollution research in indoor air is important for the protection of human health. This paper introduces the industrial application and potential harm of PCBs, summarizes the sampling, extracting, and analytical methods of environment monitoring, and compares the indoor air levels of urban areas with those of industrial areas in different countries according to various reports. This paper can provide a basic summary for PCBs pollution control in the indoor air environment. The review of PCBs pollution in indoor air in China is still limited. In this paper, we introduce the industrial application and potential harm of PCBs, summarize the sampling, extracting, and analytical methods of environment monitoring, and compare the indoor air levels of urban areas with industrial areas in different countries according to various reports.

Properties and cellular effects of particulate matter from direct emissions and ambient sources.

PubMed

Jin, Wenjie; Su, Shu; Wang, Bin; Zhu, Xi; Chen, Yilin; Shen, Guofeng; Liu, Junfeng; Cheng, Hefa; Wang, Xilong; Wu, Shuiping; Zeng, Eddy; Xing, Baoshan; Tao, Shu

2016-10-14

The pollution of particulate matter (PM) is of great concern in China and many other developing countries. It is generally recognized that the toxicity of PM is source and property dependent. However, the relationship between PM properties and toxicity is still not well understood. In this study, PM samples from direct emissions of wood, straw, coal, diesel combustion, cigarette smoking and ambient air were collected and characterized for their physicochemical properties. Their expression of intracellular reactive oxygen species (ROS) and levels of inflammatory cytokines (i.e., tumor necrosis factor-α (TNF-α)) was measured using a RAW264.7 cell model. Our results demonstrated that the properties of the samples from different origins exhibited remarkable differences. Significant increases in ROS were observed when the cells were exposed to PMs from biomass origins, including wood, straw and cigarettes, while increases in TNF-α were found for all the samples, particularly those from ambient air. The most important factor associated with ROS generation was the presence of water-soluble organic carbon, which was extremely abundant in the samples that directly resulted from biomass combustion. Metals, endotoxins and PM size were the most important properties associated with increases in TNF-α expression levels. The association of the origins of PM particles and physicochemical properties with cytotoxic properties is illustrated using a cluster analysis.

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.

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.

A fast infrared scanning technique for nondestructive testing

NASA Astrophysics Data System (ADS)

Hartikainen, Jari

1989-04-01

A simple and fast thermal NDT measurement system is described and its usefulness is demonstrated using a honeycomb structure as a test sample. The sample is heated with a hot air jet and the surface temperature differences due to subsurface defects are detected with a single HgCdTe detector. An image of the sample is formed by scanning over the sample surface with a deflection mirror in the y direction while moving the sample in the x direction. The measurement time is typically 6 s per image and several images are averaged to improve signal to noise ratio. The main advantages of this system compared to conventional infrared camera techniques are considerably reduced cost and the ease with which the system can be modified to various applications.

Legionella spp. in Puerto Rico cooling towers

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

Negron-Alvira, A.; Perez-Suarez, I.; Hazen, T.C.

1988-10-01

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, P.R., were assayed for various Legionella spp. and serogroups by using direct immunofluorescence. Several water quality parameters were also measured for each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila serogroups 1 to 6, L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species; its density reached 10{sup 5} cells per ml, which is within themore » range that is considered potentially pathogenic to humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (acridine orange direct count) were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems and that, without continuous biocide treatment, they may reach densities that present a health risk.« less

Impacts of roadway emissions on urban particulate matter concentrations in sub-Saharan Africa: new evidence from Nairobi, Kenya

NASA Astrophysics Data System (ADS)

van Vliet, E. D. S.; Kinney, P. L.

2007-10-01

Air quality is a serious and worsening problem in the rapidly growing cities of sub-Saharan Africa (SSA). However, the lack of ambient monitoring data, and particularly urban roadside concentrations for particulate matter in SSA cities severely hinders our ability to describe temporal and spatial patterns of concentrations, characterize exposure response relationships for key health outcomes, estimate disease burdens, and promote policy initiatives to address air quality. As part of a collaborative transportation planning exercise between Columbia University and the University of Nairobi, air monitoring was carried out in February 2006 in Nairobi, Kenya. The objective of the monitoring was to collect pilot data on air concentrations (PM2.5 and black carbon) encountered while driving in the Nairobi metropolitan area, and to compare those data to simultaneous 'urban background' concentrations measured in Nairobi but away from roadways. For both the background and roadway monitoring, we used portable air sampling systems that collect integrated filter samples. Results from this pilot study found that roadway concentrations of PM2.5 were approximately 20-fold higher than those from the urban background site, whereas black carbon concentrations differed by 10-fold. If confirmed by more extensive sampling, these data would underscore the need for air quality and transportation planning and management directed at mitigating roadway pollution.

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.

Interrelationships among Grain Size, Surface Composition, Air Stability, and Interfacial Resistance of Al-Substituted Li7La3Zr2O12 Solid Electrolytes.

PubMed

Cheng, Lei; Wu, Cheng Hao; Jarry, Angelique; Chen, Wei; Ye, Yifan; Zhu, Junfa; Kostecki, Robert; Persson, Kristin; Guo, Jinghua; Salmeron, Miquel; Chen, Guoying; Doeff, Marca

2015-08-19

The interfacial resistances of symmetrical lithium cells containing Al-substituted Li7La3Zr2O12 (LLZO) solid electrolytes are sensitive to their microstructures and histories of exposure to air. Air exposure of LLZO samples with large grain sizes (∼150 μm) results in dramatically increased interfacial impedances in cells containing them, compared to those with pristine large-grained samples. In contrast, a much smaller difference is seen between cells with small-grained (∼20 μm) pristine and air-exposed LLZO samples. A combination of soft X-ray absorption (sXAS) and Raman spectroscopy, with probing depths ranging from nanometer to micrometer scales, revealed that the small-grained LLZO pellets are more air-stable than large-grained ones, forming far less surface Li2CO3 under both short- and long-term exposure conditions. Surface sensitive X-ray photoelectron spectroscopy (XPS) indicates that the better chemical stability of the small-grained LLZO is related to differences in the distribution of Al and Li at sample surfaces. Density functional theory calculations show that LLZO can react via two different pathways to form Li2CO3. The first, more rapid, pathway involves a reaction with moisture in air to form LiOH, which subsequently absorbs CO2 to form Li2CO3. The second, slower, pathway involves direct reaction with CO2 and is favored when surface lithium contents are lower, as with the small-grained samples. These observations have important implications for the operation of solid-state lithium batteries containing LLZO because the results suggest that the interfacial impedances of these devices is critically dependent upon specific characteristics of the solid electrolyte and how it is prepared.

Determination of methyl bromide in air samples by headspace gas chromatography

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

Woodrow, J.E.; McChesney, M.M.; Seiber, J.N.

1988-03-01

Methyl bromide is extensively used in agriculture (4 x 10/sup 6/ kg for 1985 in California alone as a fumigant to control nematodes, weeds, and fungi in soil and insect pests in harvested grains and nuts. Given its low boiling point (3.8/sup 0/C) and high vapor pressure (approx. 1400 Torr at 20/sup 0/C), methyl bromide will readily diffuse if not rigorously contained. Methods for determining methyl bromide and other halocarbons in air vary widely. A common practice is to trap the material from air on an adsorbent, such as polymeric resins, followed by thermal desorption either directly into the analyticalmore » instrumentation or after intermediary cryofocusing. While in some cases analytical detection limits were reasonable (parts per million range), many of the published methods were labor intensive and required special handling techniques that precluded high sample throughput. They describe here a method for the sampling and analysis of airborne methyl bromide that was designed to handle large numbers of samples through automating some critical steps of the analysis. The result was a method that allowed around-the-clock operation with a minimum of operator attention. Furthermore, the method was not specific to methyl bromide and could be used to determine other halocarbons in air.« less

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.

Estimating the change of porosity in the saturated zone during air sparging.

PubMed

Tsai, Yih-jin; Kuo, Yu-chia; Chen, Tsu-chi; Chou, Feng-chih

2006-01-01

Air sparging is a remedial method for groundwater. The remedial region is similar to the air flow region in the saturated zone. If soil particles are transported during air sparging, the porosity distributions in the saturated zone change, which may alter the flow path of the air. To understand better the particle movement, this study performed a sandbox test to estimate the soil porosity change during air sparging. A clear fracture was formed and the phenomenon of particle movement was observed when the air injection was started. The moved sand filled the porous around the fracture and the reparked sand filled the fracture, reducing the porosity around the fracture. The results obtained from the photographs of the sandbox, the current measurements and the direct sand sample measurements were close to each other and are credible. Therefore, air injection during air sparging causes sand particle movement of sand, altering the characteristic of the sand matrix and the air distribution.

Comparison of direct and indirect methods of measuring airborne chrysotile fibre concentration.

PubMed

Eypert-Blaison, Celine; Veissiere, Sylvie; Rastoix, Olivier; Kauffer, Edmond

2010-01-01

Transmission electron microscopy observations most frequently form a basis for estimating asbestos fibre concentration in the environment and in buildings with asbestos-containing materials. Sampled fibres can be transferred to microscope grids by applying either a direct [ISO (1995) Draft International ISO/DIS 10312. Ambient air. Determination of asbestos fibres. Direct transfer transmission electron microscopy procedure. Geneva, Switzerland: International Standardization Organization] or an indirect [AFNOR (1996) Détermination de la concentration en fibres d'amiante par microscopie électronique à transmission-Méthode indirecte. Cedex, France: AFNOR, p. 42; ISO (1997) Draft International ISO/DIS 13794. Ambient air. Determination of asbestos fibres. Indirect-transfer transmission electron microscopy procedure. Geneva, Switzerland: International Standardization Organization] method. In the latter case, ISO Standard 13794 recommends filtering calcination residues either on a polycarbonate (PC) filter (PC indirect method) or on a cellulose ester (CE) membrane (CE indirect method). The PC indirect method requires that fibres deposited on a PC filter be covered by a carbon layer, whereas in the CE indirect method, the CE membrane has to be directly processed using a method described in ISO Standard 10312. The purpose of this study was to compare results obtained using, on the one hand, direct preparation methods and, on the other hand, PC indirect or CE indirect methods, for counting asbestos fibres deposited on filters as a result of liquid filtration or air sampling. In direct method-based preparation, we observed that an etching time of 6-14 min does not affect the measured densities, except for fibres <1 microm deposited by liquid filtration. Moreover, in all cases, the direct method gives higher densities than the PC indirect method because of possible fibre disappearance when using the carbon evaporator implemented in the PC indirect method. The CE membrane used for sample preparation in the CE indirect method is collapsed prior to passing it through the carbon evaporator, so the fibres are less likely to disappear at this stage. We then note that the resulting fibre densities for chrysotile-loaded filters prepared using the direct method are close to those obtained with filters prepared using the CE indirect method. Our study therefore shows that, under the implemented experimental conditions, the PC and CE indirect preparation methods described in ISO Standard 13794 are not equivalent.

Assessment of human exposure to polychlorinated dibenzofurans and dioxins.

PubMed Central

Rappe, C; Nygren, M; Marklund, S; Keller, L O; Bergqvist, P A; Hansson, M

1985-01-01

Fires, explosions and other accidents in polychlorinated biphenyl (PCB)-filled equipment can result in possible exposure of firemen, cleaning personnel and regular workers. Inhalation, dermal exposure and ingestion are the possible routes of exposure. An indirect assessment of the exposure can be made by analyses of wipes, air and water samples and clothes. A direct assessment of exposure can be made by analyses of blood samples, adipose and other tissue samples, feces and bile. PMID:4029099

Analytical instrument with apparatus and method for sample concentrating

DOEpatents

Zaromb, S.

1986-08-04

A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Analytical instrument with apparatus for sample concentrating

DOEpatents

Zaromb, Solomon

1989-01-01

A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

Method for preconcentrating a sample for subsequent analysis

DOEpatents

Zaromb, Solomon

1990-01-01

A system for analysis of trace concentration of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

THE DETERMINATION OF MERCURY SPECIES AND MULTIPLE METALS IN COAL COMBUSTION EMISSIONS USING IODINE-BASED IMPINGERS AND DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

EPA Science Inventory

Mercury (Hg) emissions from coal utilities are difficult to control. Hg eludes capture by most air pollution control devices (APCDs). To determine the gaseous Hg species in stack gases, U.S. EPA Method 5 type sampling is used. In this type of sampling a hole is drilled into th...

Method optimization for non-equilibrium solid phase microextraction sampling of HAPs for GC/MS analysis

NASA Astrophysics Data System (ADS)

Zawadowicz, M. A.; Del Negro, L. A.

2010-12-01

Hazardous air pollutants (HAPs) are usually present in the atmosphere at pptv-level, requiring measurements with high sensitivity and minimal contamination. Commonly used evacuated canister methods require an overhead in space, money and time that often is prohibitive to primarily-undergraduate institutions. This study optimized an analytical method based on solid-phase microextraction (SPME) of ambient gaseous matrix, which is a cost-effective technique of selective VOC extraction, accessible to an unskilled undergraduate. Several approaches to SPME extraction and sample analysis were characterized and several extraction parameters optimized. Extraction time, temperature and laminar air flow velocity around the fiber were optimized to give highest signal and efficiency. Direct, dynamic extraction of benzene from a moving air stream produced better precision (±10%) than sampling of stagnant air collected in a polymeric bag (±24%). Using a low-polarity chromatographic column in place of a standard (5%-Phenyl)-methylpolysiloxane phase decreased the benzene detection limit from 2 ppbv to 100 pptv. The developed method is simple and fast, requiring 15-20 minutes per extraction and analysis. It will be field-validated and used as a field laboratory component of various undergraduate Chemistry and Environmental Studies courses.

Atmospheric CO2 Concentrations--The Canadian Background Air Pollution Monitoring Network (1993) (NDP-034)

DOE Data Explorer

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

1993-01-01

Flask air samples collected at roughly weekly intervals at three Canadian sites [Alert, Northwest Territories (July 1975 through July 1992); Sable Island, Nova Scotia (March 1975 through July 1992); and Cape St. James, British Columbia (May 1979 through July 1992)] were analyzed for CO2 concentration with the measurements directly traceable to the WMO primary CO2 standards. Each record includes the date, atmospheric CO2 concentration, and flask classification code. They provide an accurate record of CO2 concentration levels in Canada during the past two decades. Because these data are directly traceable to WMO standards, this record may be compared with records from other Background Air Pollution Monitoring Network (BAPMoN) stations. The data are in three files (one for each of the monitoring stations) ranging in size from 9.4 to 20.1 kB.

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

Monroy, G.J. Keene, F.E.

A study to address Ambos (Both) Nogales' air quality concerns was conducted by the Arizona Department of Environmental Quality (ADEQ), in conjunction with Mexico's Secretaria de Medio Ambiente, Recursos Naturales y Pesca (SEMARNAP), from 1994 to 1998. The study, which is part of the US-Mexico Border XXI Program, consisted of the following tasks: (1) air sampling/monitoring; (2) emissions inventory; (3) meteorological modeling; and, (4) health risk assessment. The following types of samples were collected: particulate matter (PM); volatile organic compounds; semi-volatile organic compounds; and aldehydes. All samples were collected for a 24-hour period; every sixth day during the warm monthsmore » (April--September), and every third day during the cold months (October--March). There were a total of six sampling stations; three on each side of the border. PM samples were collected at all six sites, while samples for Hazardous Air Pollutants (HAPs) were collected at four of those sites. Sample analyses were performed at the Desert Research Institute (DRI) in Reno, Nevada. Furthermore, four of the sites were outfitted with meteorological equipment, in order to gather data on wind speed and direction. PM and meteorological data are still being collected at two sampling sites, one in Arizona and one in Sonora. An emissions inventory of point, mobile and area sources for the Ambos Nogales area (12 x 19 km. domain), was developed following completion of the sampling effort. In order to accomplish this task, ADEQ contracted the services of RADIAN International and Powers Engineering; which in turn enlisted the services of Heuristica Ambiental of Hermosillo, Sonora. This task was completed in July, 1997. Vehicular emissions were found to be one of the main contributors of air emissions in the Ambos Nogales area. The third task of this project consisted developing meteorological models of the study area.« less

Time-Lapse Micro-Tomography Measurements and Determination of Effective Transport Properties of Snow Metamorphism Under Advective Conditions

NASA Astrophysics Data System (ADS)

Ebner, P. P.; Grimm, S.; Steen-Larsen, H. C.; Schneebeli, M.; Steinfeld, A.

2014-12-01

The metamorphism of snow under advective air flow, with and without temperature gradient, was never experimentally investigated. We developed a new sample holder where metamorphism under advective conditions can be observed and measured using time-lapse micro-tomography [1]. Long-term experiments were performed and direct pore-level simulation (DPLS) [2,3] was directly applied on the extracted 3D digital geometry of the snow to calculate the effective transport properties by solving the governing fluid flow equations. The results showed no effect of isothermal advection, compared to rates typical for isothermal metamorphism. Appling a temperature gradient, the results showed increased snow metamorphism compared to rates typical for temperature gradient metamorphism. However, for both cases a change in the isotopic composition in the air as well as in the snow sample could be observed. These measurements could be influential to better understand snow-air exchange processes relevant for atmospheric chemistry and isotopic composition. REFERENCES[1] Ebner P. P., Grimm S., Schneebeli M., and Steinfeld A.: An instrumented sample holder for time-lapse micro-tomography measurements of snow under advective airflow. Geoscientific Instrumentation, Methods and Data Systems 4(2014), 353-373. [2] Zermatten E., Haussener S., Schneebeli M., and Steinfeld A.: Tomography-based determination of permeability and Dupuit-Forchheimer coefficient of characteristic snow samples. Journal of Glaciology 57(2011), 811-816. [3] Zermatten E., Schneebeli M., Arakawa H., and Steinfeld A.: Tomography-based determination of porosity, specific area and permeability of snow and comparison with measurements. Cold Regions Science and Technology 97 (2014), 33-40. Fig. 1: 3-D surface rendering of a refrozen wet snow sample with fluid flow streamline.

Ambient air quality at the wider area of an industrial mining facility at Stratoni, Chalkidiki, Greece.

PubMed

Gaidajis, Georgios; Angelakoglou, Komninos; Gazea, Emmy

2012-01-01

To assess ambient air quality at the wider area of a mining-industrial facility in Chalkidiki, Greece, the particulate matter with an aerodynamic diameter of 10 μm (PM(10)) and its content in characteristic elements, i.e., As, Cd, Cu, Fe, Mn, Pb, Zn were monitored for a period of three years (2008-2010). Gravimetric air samplers were employed for the particulate matter sampling at three sampling stations located in the immediate vicinity of the industrial facility and at a neighbouring residential site. Monitoring data indicated that the 3-year median PM(10) concentrations were 23.3 μg/m(3) at the residential site close to the facility and 28.7 μg/m(3) at the site within the facility indicating a minimal influence from the industrial activities to the air quality of the neighbouring residential area. Both annual average and median PM(10) concentration levels were below the indicative European standards, whereas similar spatial and temporal variation was observed for the PM(10) constituents. The average Pb concentrations measured for the three sampling sites were 0.2, 0.146 and 0.174 μg/m(3) respectively, well below the indicative limit of 0.5 μg/m(3). The quantitative and qualitative comparison of PM(10) concentrations and its elemental constituent for the three sampling stations did not indicate any direct influence of the mining-industrial activities to the air quality of the Stratoni residential area.

Photochemical ozone budget during the BIBLE A and B campaigns

NASA Astrophysics Data System (ADS)

Ko, Malcolm; Hu, Wenjie; Rodríguez, José M.; Kondo, Yutaka; Koike, Makoto; Kita, Kazuyuki; Kawakami, Shuji; Blake, Donald; Liu, Shaw; Ogawa, Toshihiro

2003-02-01

Using the measured concentrations of NO, O3, H2O, CO, CH4, and NMHCs along the flight tracks, a photochemical box model is used to calculate the concentrations of the Ox radicals, the HOx radicals, and the nitrogen species at the sampling points. The calculations make use of the measurements from radiometers to scale clear sky photolysis rates to account for cloud cover and ground albedo at the sampling time/point. The concentrations of the nitrogen species in each of the sampled air parcels are computed assuming they are in instantaneous equilibrium with the measured NO and O3. The diurnally varying species concentrations are next calculated using the box model and used to estimate the diurnally averaged production and removal rates of ozone for the sampled air parcels. Clear sky photolysis rates are used in the diurnal calculations. The campaign also provided measured concentration of NOy. The observed NO/NOy ratio is usually larger than the model calculated equilibrium value. There are several possible explanations. It could be a result of recent injection of NO into the air parcel, recent removal of HNO3 from the parcel, recent rapid transport of an air parcel from another location, or a combination of all processes. Our analyses suggest that the local production rate of O3 can be used as another indicator of recent NO injection. However, more direct studies using air trajectory analyses and other collaborative evidences are needed to ascertain the roles played by individual process.

Photochemical ozone budget during the BIBLE A and B campaigns

NASA Astrophysics Data System (ADS)

Ko, Malcolm; Hu, Wenjie; RodríGuez, José M.; Kondo, Yutaka; Koike, Makoto; Kita, Kazuyuki; Kawakami, Shuji; Blake, Donald; Liu, Shaw; Ogawa, Toshihiro

2002-02-01

Using the measured concentrations of NO, O3, H2O, CO, CH4, and NMHCs along the flight tracks, a photochemical box model is used to calculate the concentrations of the Ox radicals, the HOx radicals, and the nitrogen species at the sampling points. The calculations make use of the measurements from radiometers to scale clear sky photolysis rates to account for cloud cover and ground albedo at the sampling time/point. The concentrations of the nitrogen species in each of the sampled air parcels are computed assuming they are in instantaneous equilibrium with the measured NO and O3. The diurnally varying species concentrations are next calculated using the box model and used to estimate the diurnally averaged production and removal rates of ozone for the sampled air parcels. Clear sky photolysis rates are used in the diurnal calculations. The campaign also provided measured concentration of NOy. The observed NO/NOy ratio is usually larger than the model calculated equilibrium value. There are several possible explanations. It could be a result of recent injection of NO into the air parcel, recent removal of HNO3 from the parcel, recent rapid transport of an air parcel from another location, or a combination of all processes. Our analyses suggest that the local production rate of O3 can be used as another indicator of recent NO injection. However, more direct studies using air trajectory analyses and other collaborative evidences are needed to ascertain the roles played by individual process.

Criteria pollutant and acid aerosol characterization study, Catano, Puerto Rico

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

Edgerton, E.S.; Harlos, D.P.; Sune, J.M.

1995-07-01

The primary objective of the Catano Criteria Pollutant and Acid Aerosol Characterization Study (CPAACS) was to measure criteria pollutant concentrations and acid aerosol concentrations in and around the Ward of Catano, Puerto Rico, during the summer of 1994. Continuous air sampling for criteria pollutants was performed at three fixed stations and one moobile station that was deployed to four locations. Air samples for acid aerosol analyses and particulate matter measurements were collected at three sites. Semicontinuous sulfate analysis was performed at the primary site. Continuous measurements of wind speed, wind direction, temperature, and relative humidity were also made at eachmore » site. The study was conducted from June 1 through September 30, 1994.« less

Measurement of volatile organic compounds emitted in libraries and archives: an inferential indicator of paper decay?

PubMed Central

2012-01-01

Background A sampling campaign of indoor air was conducted to assess the typical concentration of indoor air pollutants in 8 National Libraries and Archives across the U.K. and Ireland. At each site, two locations were chosen that contained various objects in the collection (paper, parchment, microfilm, photographic material etc.) and one location was chosen to act as a sampling reference location (placed in a corridor or entrance hallway). Results Of the locations surveyed, no measurable levels of sulfur dioxide were detected and low formaldehyde vapour (< 18 μg m-3) was measured throughout. Acetic and formic acids were measured in all locations with, for the most part, higher acetic acid levels in areas with objects compared to reference locations. A large variety of volatile organic compounds (VOCs) was measured in all locations, in variable concentrations, however furfural was the only VOC to be identified consistently at higher concentration in locations with paper-based collections, compared to those locations without objects. To cross-reference the sampling data with VOCs emitted directly from books, further studies were conducted to assess emissions from paper using solid phase microextraction (SPME) fibres and a newly developed method of analysis; collection of VOCs onto a polydimethylsiloxane (PDMS) elastomer strip. Conclusions In this study acetic acid and furfural levels were consistently higher in concentration when measured in locations which contained paper-based items. It is therefore suggested that both acetic acid and furfural (possibly also trimethylbenzenes, ethyltoluene, decane and camphor) may be present in the indoor atmosphere as a result of cellulose degradation and together may act as an inferential non-invasive marker for the deterioration of paper. Direct VOC sampling was successfully achieved using SPME fibres and analytes found in the indoor air were also identified as emissive by-products from paper. Finally a new non-invasive, method of VOC collection using PDMS strips was shown to be an effective, economical and efficient way of examining VOC emissions directly from the pages of a book and confirmed that toluene, furfural, benzaldehyde, ethylhexanol, nonanal and decanal were the most concentrated VOCs emitted directly from paper measured in this study. PMID:22587759

Coatings for directional eutectics

NASA Technical Reports Server (NTRS)

Rairden, J. R.; Jackson, M. R.

1976-01-01

Coatings developed to provide oxidation protection for the directionally-solidified eutectic alloy NiTaC-B (4.4 weight percent Cr) were evaluated. Of seven Co-, Fe- and Ni-base coatings that were initially investigated, best resistance to cyclic oxidation was demonstrated by duplex coatings fabricated by depositing a layer of NiCrAl(Y) by vacuum evaporation from an electron beam source followed by deposition of an Al overlayer using the pack cementation process. It was found that addition of carbon to the coating alloy substantially eliminated the problem of fiber denudation in TaC-type eutectic alloys. Burner rig cycled NiTaC-B samples coated with Ni-20Cr-5Al-0.1C-0.1Y+Al and rupture-tested at 1100 deg C performed as well as or better than uncoated, vacuum cycled and air-tested NiTaC-13; however, a slight degradation with respect to uncoated material was noted in air-stress rupture tests at 870 deg C for both cycled and uncycled samples.

Solubility testing of actinides on breathing-zone and area air samples

NASA Astrophysics Data System (ADS)

Metzger, Robert Lawrence

The solubility of inhaled radionuclides in the human lung is an important characteristic of the compounds needed to perform internal dosimetry assessments for exposed workers. A solubility testing method for uranium and several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALSsp°ler ) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of Usb3Osb8. This makes it possible to characterize solubility profiles in every section of operating facilities where airborne nuclides are found using common breathing zone air samples. The new method was evaluated by analyzing uranium compounds from two uranium mills whose product had been previously analyzed by in vitro solubility testing in the laboratory and in vivo solubility testing in rodents. The new technique compared well with the in vivo rodent solubility profiles. The method was then used to evaluate the solubility profiles in all process sections of an operating in situ uranium plant using breathing zone and area air samples collected during routine plant operations. The solubility profiles developed from this work showed excellent agreement with the results of the worker urine bioassay program at the plant and identified a significant error in existing internal dose assessments at this facility.

Compressed-air power tools in orthopaedic surgery: exhaust air is a potential source of contamination.

PubMed

Sagi, H C; DiPasquale, Thomas; Sanders, Roy; Herscovici, Dolfi

2002-01-01

To determine if the exhaust from surgical compressed-air power tools contains bacteria and if the exhaust leads to contamination of sterile surfaces. Bacteriologic study of orthopaedic power tools. Level I trauma center operative theater. None. Part I. Exhaust from two sterile compact air drills was sampled directly at the exhaust port. Part II. Exhaust from the drills was directed at sterile agar plates from varying distances. The agar plates represented sterile surfaces within the operative field. Part III. Control cultures. A battery-powered drill was operated over open agar plates in similar fashion as the compressed-air drills. Agar plates left open in the operative theater served as controls to rule out atmospheric contamination. Random cultures were taken from agar plates, gloves, drills, and hoses. Incidence of positive cultures. In Part I, all filters from both compressed-air drill exhausts were culture negative ( = 0.008). In Part II, the incidence of positive cultures for air drills number one and number two was 73% and 82%, respectively. The most commonly encountered organisms were, coagulase-negative Staphylococcus, and Micrococcus species. All control cultures from agar plates, battery-powered drill, gloves, and hoses were negative ( < 0.01). Exhaust from compressed-air power tools in orthopaedic surgery may contribute to the dissemination of bacteria onto the surgical field. We do not recommend the use of compressed-air power tools that do not have a contained exhaust.

Assessing genetic structure and diversity of airborne bacterial communities by DNA fingerprinting and 16S rDNA clone library

NASA Astrophysics Data System (ADS)

Maron, Pierre-Alain; Lejon, David P. H.; Carvalho, Esmeralda; Bizet, Karine; Lemanceau, Philippe; Ranjard, Lionel; Mougel, Christophe

The density, genetic structure and diversity of airborne bacterial communities were assessed in the outdoor atmosphere. Two air samples were collected on the same location (north of France) at two dates (March 2003 (sample1) and May 2003 (sample 2)). Molecular culture -independent methods were used to characterise airborne bacterial communities regardless of the cell culturability. The automated-ribosomal intergenic spacer analysis (A-RISA) was performed to characterise the community structure in each sample. For both sampling dates, complex A-RISA patterns were observed suggesting a highly diverse community structure, comparable to those found in soil, water or sediment environments. Furthermore, differences in the genetic structure of airborne bacterial communities were observed between samples 1 and 2 suggesting an important variability in time. A clone library of 16S rDNA directly amplified from air DNA of sample 1 was constructed and sequenced to analyse the community composition and diversity. The Proteobacteria group had the greatest representation (60%), with bacteria belonging to the different subdivisions α- (19%), β-(21%), γ-(12%) and δ-(8%). Firmicute and Actinobacteria were also well represented with 14% and 12%, respectively. Most of the identified bacteria are known to be commonly associated with soil or plant environments suggesting that the atmosphere is mainly colonised transiently by microorganisms from local sources, depending on air fluxes.

Detection of Methyl Salicylate Transforted by Honeybees (Apis mellifera) Using Solid Phase Microextration (SPME) Fibers

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

BENDER, SUSAN FAE ANN; RODACY, PHILIP J.; BARNETT, JAMES L.

The ultimate goal of many environmental measurements is to determine the risk posed to humans or ecosystems by various contaminants. Conventional environmental monitoring typically requires extensive sampling grids covering several media including air, water, soil and vegetation. A far more efficient, innovative and inexpensive tactic has been found using honeybees as sampling mechanisms. Members from a single bee colony forage over large areas ({approx}2 x 10{sup 6} m{sup 2}), making tens of thousands of trips per day, and return to a fixed location where sampling can be conveniently conducted. The bees are in direct contact with the air, water, soilmore » and vegetation where they encounter and collect any contaminants that are present in gaseous, liquid and particulate form. The monitoring of honeybees when they return to the hive provides a rapid method to assess chemical distributions and impacts (1). The primary goal of this technology is to evaluate the efficiency of the transport mechanism (honeybees) to the hive using preconcentrators to collect samples. Once the extent and nature of the contaminant exposure has been characterized, resources can be distributed and environmental monitoring designs efficiently directed to the most appropriate locations. Methyl salicylate, a chemical agent surrogate was used as the target compound in this study.« less

Sampling of atmospheric carbonyl compounds for determination by liquid chromatography after 2,4-dinitrophenylhydrazine labelling

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

Vairavamurthy, A.; Roberts, J.M.; Newman, L.

1991-06-01

Carbonyl compounds are both primary (directly emitted) and secondary (formed in situ) atmospheric species, which play a major role in tropospheric photochemistry. Because of trace concentrations (parts-per-billion and lower), ambient air measurements of carbonyls pose serious analytical problems. Generally, chromatographic approaches combined with chemical derivatization have been used to enhance sensitivity and selectivity in analysis. Currently, the liquid chromatographic method coupled to 2,4-dinitrophenylhydrazine derivatization (DNPH-LC) is in widespread use. Interferences arising from similar compounds are greatly minimized by chromatographic separation; however, those in the air sampling step, especially with ozone, continue to be problematic and remain to be resolved. Wemore » discuss here the different sampling techniques used for time-integrated collection of carbonyls in the DNPH-LC methods. Emphasis is placed on addressing: (1) the principles, advantages, and limitations of sampling techniques; (2) problems associated with reagent blank and sampling instrument; and (3) effects of atmospheric co-pollutants, especially ozone. 58 refs., 8 figs., 3 tabs.« less

Brominated flame retardants in the surrounding soil of two manufacturing plants in China: Occurrence, composition profiles and spatial distribution.

PubMed

Li, Wen-Long; Liu, Li-Yan; Zhang, Zi-Feng; Song, Wei-Wei; Huo, Chun-Yan; Qiao, Li-Na; Ma, Wan-Li; Li, Yi-Fan

2016-06-01

Surface soil samples were collected surrounding two brominated flame retardants (BFRs) manufacturing plants in China in August 2014 and analyzed for 23 polybrominated diphenyl ethers (PBDEs) and 8 novel brominated flame retardants (NBFRs). BDE209 and decabromodiphenylethane (DBDPE) were the predominant compounds in soil with the median levels of 1600 and 560 ng/g dw, respectively. The PBDEs profiles in soil samples were consistent with that of commercial product (comDecaBDE). The percentage contributions to total PBDEs decreased from higher to lower brominated homologues. Lower concentrations of NBFRs (excluding DBDPE) were detected in soil surrounding the two plants, suggesting they are byproducts or degradation products of the manufacturing activities. The concentrations of most BFRs dropped exponentially within 3-5 km of the manufacturing plants, suggesting recent deposition of these compounds to the soil. Directional distribution indicated that PBDEs and DBDPE concentrations were highest in the north direction of Plants 1. Three-day air parcel forward trajectories confirmed that the air parcel was responsible for the higher concentration of BFRs in the soil of north direction of the plant. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ammonia release from heated 'street' cannabis leaf and its potential toxic effects on cannabis users.

PubMed

Bloor, Roger N; Wang, Tianshu S; Spanel, Patrik; Smith, David

2008-10-01

To use selected ion flow tube mass spectrometry (SIFT-MS) to analyse the molecular species emitted by heated 'street' cannabis plant material, especially targeting ammonia. Samples of 'street' cannabis leaf, held under a UK Home Office licence, were prepared by finely chopping and mixing the material. The samples were then heated in commercially available devices. The air containing the released gaseous compounds was sampled into the SIFT-MS instrument for analysis. Smoke from standard 3% National Institute on Drug Abuse (NIDA) cannabis cigarettes was also analysed. For 'street' cannabis, ammonia was present in the air samples from the devices at levels approaching 200 parts per million (p.p.m.). This is compared with peak levels of 10 p.p.m. using NIDA samples of known provenance and tetrahydrocannabinol content (3%). Several other compounds were present at lower levels, including acetaldehyde, methanol, acetone, acetic acid and uncharacterized terpenes. Awareness of the risks of inhaling the smoke directly from burning cannabis has led to the development of a number of alternative methods of delivery, which are claimed to be safer than direct smoking. Ammonia at toxic levels is produced from heating 'street' cannabis in these commercially available devices. Thus, the use of these devices to deliver 'street' cannabis is now open to question and further research is needed to investigate their safety.

Elemental analysis of size-fractionated particulate matter sampled in Göteborg, Sweden

NASA Astrophysics Data System (ADS)

Wagner, Annemarie; Boman, Johan; Gatari, Michael J.

2008-12-01

The aim of the study was to investigate the mass distribution of trace elements in aerosol samples collected in the urban area of Göteborg, Sweden, with special focus on the impact of different air masses and anthropogenic activities. Three measurement campaigns were conducted during December 2006 and January 2007. A PIXE cascade impactor was used to collect particulate matter in 9 size fractions ranging from 16 to 0.06 µm aerodynamic diameter. Polished quartz carriers were chosen as collection substrates for the subsequent direct analysis by TXRF. To investigate the sources of the analyzed air masses, backward trajectories were calculated. Our results showed that diurnal sampling was sufficient to investigate the mass distribution for Br, Ca, Cl, Cu, Fe, K, Sr and Zn, whereas a 5-day sampling period resulted in additional information on mass distribution for Cr and S. Unimodal mass distributions were found in the study area for the elements Ca, Cl, Fe and Zn, whereas the distributions for Br, Cu, Cr, K, Ni and S were bimodal, indicating high temperature processes as source of the submicron particle components. The measurement period including the New Year firework activities showed both an extensive increase in concentrations as well as a shift to the submicron range for K and Sr, elements that are typically found in fireworks. Further research is required to validate the quantification of trace elements directly collected on sample carriers.

Evaluation of airborne asbestos exposure from routine handling of asbestos-containing wire gauze pads in the research laboratory.

PubMed

Garcia, Ediberto; Newfang, Daniel; Coyle, Jayme P; Blake, Charles L; Spencer, John W; Burrelli, Leonard G; Johnson, Giffe T; Harbison, Raymond D

2018-07-01

Three independently conducted asbestos exposure evaluations were conducted using wire gauze pads similar to standard practice in the laboratory setting. All testing occurred in a controlled atmosphere inside an enclosed chamber simulating a laboratory setting. Separate teams consisting of a laboratory technician, or technician and assistant simulated common tasks involving wire gauze pads, including heating and direct wire gauze manipulation. Area and personal air samples were collected and evaluated for asbestos consistent with the National Institute of Occupational Safety Health method 7400 and 7402, and the Asbestos Hazard Emergency Response Act (AHERA) method. Bulk gauze pad samples were analyzed by Polarized Light Microscopy and Transmission Electron Microscopy to determine asbestos content. Among air samples, chrysotile asbestos was the only fiber found in the first and third experiments, and tremolite asbestos for the second experiment. None of the air samples contained asbestos in concentrations above the current permissible regulatory levels promulgated by OSHA. These findings indicate that the level of asbestos exposure when working with wire gauze pads in the laboratory setting is much lower than levels associated with asbestosis or asbestos-related lung cancer and mesothelioma. Copyright © 2018. Published by Elsevier Inc.

Microbial Air and Surface Monitoring Results from International Space Station Samples

NASA Technical Reports Server (NTRS)

Ott, C. Mark; Bruce, Rebekah J.; Castro, Victoria A.; Novikova, Natalia D.; Pierson, D. L.

2005-01-01

Over the course of long-duration spaceflight, spacecraft develop a microbial ecology that directly interacts with the crew of the vehicle. While most microorganisms are harmless or beneficial to the inhabitants of the vehicle, the presence of medically significant organisms appearing in this semi-closed environment could adversely affect crew health and performance. The risk of exposure of the crew to medically significant organisms during a mission is estimated using information gathered during nominal and contingency environmental monitoring. Analysis of the air and surface microbiota in the habitable compartments of the International Space Station (ISS) over the last four years indicate a high presence of Staphylococcus species reflecting the human inhabitants of the vehicle. Generally, air and surface microbial concentrations are below system design specifications, suggesting a lower risk of contact infection or biodegradation. An evaluation of sample frequency indicates a decrease in the identification of new species, suggesting a lower potential for unknown microorganisms to be identified. However, the opportunistic pathogen, Staphylococcus aureus, has been identified in 3 of the last 5 air samples and 5 of the last 9 surface samples. In addition, 47% of the coagulase negative Staphylococcus species that were isolated from the crew, ISS, and its hardware were found to be methicillin resistance. In combination, these observations suggest the potential of methicillin resistant infectious agents over time.

A Novel Method making direct use of AIRS and IASI Calibrated Radiances for Measuring Trends in Surface Temperatures

NASA Astrophysics Data System (ADS)

Aumann, H. H.; Ruzmaikin, A.

2014-12-01

Making unbiased measurements of trends in the surface temperatures, particularly on a gobal scale, is challenging: While the non-frozen oceans temperature measurements are plentiful and accurate, land and polar areas are much less accurately or fairly sampled. Surface temperature deduced from infrared radiometers on polar orbiting satellites (e.g. the Atmospheric Infrared Sounder (AIRS) at 1:30PM, the Interferometer Atmosphere Sounding Interferometer (IASI) at 9:30 AM and the MODerate resolution Imaging Spectro-radiometer (MODIS) at 1:30PM), can produce what appear to be well sampled data, but dealing with clouds either by cloud filtering (MODIS, IASI) or cloud-clearing (AIRS) can create sampling bias. We use a novel method: Random Nadir Sampling (RNS) combined with Probability Density Function (PDF) analysis. We analyze the trend in the PDF of st1231, the water vapor absorption corrected brightness temperatures measured in the 1231 cm-1 atmospheric window channel. The advantage of this method is that trends can be directly traced to the known, less than 3 mK/yr trend for AIRS, in st1231. For this study we created PDFs from 22,000 daily RNS from the AIRS and IASI data. We characterized the PDFs by its daily 90%tile value, st1231p90, and analysed the statistical properties of the this time series between 2002 and 2014. The method was validated using the daily NOAA SST (RTGSST) from the non-frozen oceans: The mean, seasonal variability and anomaly trend of st1231p90 agree with the corrsponding values from the RTGSST and the anomaly correlation is larger than 0.9. Preliminary results (August 2014) confirm the global hiatus in the increase of the globally averaged surface temperatures between 2002 and 2014, with a change of less than 10 mK/yr. This uncertainty is dominated by the large interannual variability related to El Niño events. Further insite is gained by analyzing land/ocean, day/night, artic and antarctic trends. We observe a massive warming trend in the Artic between 2002 and 2007, which has since level off, but no significant trend in the Antarctic. The AIRS results since 2002 are confirmed by IASI data since 2007. This work was supported by the Jet Propulsion Laboratory of the California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Relationship Between Precipitation Chemistry and Meteorological Parameters at a Urban Site in the North of Queretaro State

NASA Astrophysics Data System (ADS)

García Martínez, R.; Hernández, G.; Solis, S.; Torres, M. D.; Padilla, H.; Báez, A.

2010-12-01

A total of 50 wet precipitation samples were collected per event at the Juriquilla site from mid-May 2009 to the end of May 2010. The Juriquilla sampling site was located on the roof of the Geoscience Building, Universidad Nacional Autónoma de México, at the Juriquilla Campus in the city of Querétaro located at 20°41'58"N and 100°27'28" W, at 1920 meters above sea level (masl). Sampling was done in passive collectors that consisted of a high density polyethylene funnel connected to a 2-liter polyethylene bottle, supported by a rod 1.5 m above the roof. One of the collectors was used to take samples for trace metals. The analysis was done in soluble and insoluble fractions. Al, Ag, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V and Zn were analyzed by atomic absorption spectroscopy with a graphite furnace accessory. The other collector was used to measure pH and major ions (SO4-2, Cl-, NO3-, Ca2+, Mg2+, Na+, K+ and NH4+) in the soluble fractions, because it was assumed that these ions are completely soluble in rainwater. The major ions SO4-2, Cl-, and NO3-, were analyzed by a Varian Model 2010 ion chromatograph; Ca2+, Mg2+, Na+ and K+ were determined by flame atomic absorption spectrometry and NH4+ by a UV spectrophotometer. In this study, synoptic maps were used to analyze the transport of air masses before rainfall, enabling back trajectories to be used to estimate the source region of pollutants. To understand the variety of synoptic weather conditions, data were associated with the corresponding air mass back trajectories calculated by the NOAA HYSPLIT model (Hybrid Single-Particle Lagrangian Integrated Trajectory Model). Back trajectory models have very simple advection schemes to calculate the previous position of an air parcel by using estimated wind speed and direction for the time period prior to arrival at the selected site. In this study, the origin of the air mass for an event was evaluated by a three-day back-trajectory before arrival to Queretaro. Mass back trajectories were calculated for 1000 and 2000 meters above ground level (MAGL), because winds at these levels should be a good approximation to the mean transport wind, since this pressure level frequently lies near the center of the transport layer. Finally, trajectories were classified by eight different directions according to the directions of the air masses before rainfall.

Direct synthesis of BiCuChO-type oxychalcogenides by mechanical alloying

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

Pele, Vincent; Barreteau, Celine; CNRS, Orsay F-91405

2013-07-15

We report on the direct synthesis of BiCuChO based materials by mechanical alloying (Ch=Se, Te). We show that contrary to the synthesis paths used in the previous reports dealing with this family of materials, which use costly annealings in closed silica tubes under controlled atmosphere, this new synthesis route enables the synthesis of pure phase materials at room temperature under air, with reasonable milling time. This synthesis procedure is easily scalable for large scale applications. - Highlights: • Phase pure BiCuSeO doped and undoped prepared by mechanical alloying. • Synthesis performed under air at room temperature. • Electrical properties similarmore » to that of samples synthesized by a classical path.« less

Density assessment and mapping of microorganisms around a biocomposting plant in Sanandaj, Iran.

PubMed

Rashidi, Sanaz; Shahmoradi, B; Maleki, Afshin; Sharafi, Kiomars; Darvishi, Ebrahim

2017-05-01

Exposure to microorganisms can cause various diseases or exacerbate the excitatory responses, inflammation, dry cough and shortness of breath, reduced lung function, chronic obstructive pulmonary disease, and allergic response or allergic immune. The aim of the present study was to investigate the density of microorganisms around the air of processing facilities of a biocomposting plant. Each experiment was carried out according to ASTM E884-82 (2001) method. The samples were collected from inhaled air in four locations of the plant, which had a high traffic of workers and employees, including screen, conveyor belt, aerated compost pile, and static compost pile. The sampling was repeated five times for each location selected. The wind speed and its direction were measured using an anemometer. Temperature and humidity were also recorded at the time of sampling. The multistage impactor used for sampling was equipped with a solidified medium (agar) and a pump (with a flow rate of 28.3 l/m) for passing air through the media. It was found that the mean density of total bacteria was >1.7 × 10 3  cfu/m 3 in the study area. Moreover, the mean densities of fungi, intestinal bacteria (Klebsiella), and Staphylococcus aureus were 5.9 × 10 3 , 3.3 × 10 3 , and 4.1 × 10 3  cfu/m 3 , respectively. In conclusion, according to the findings, the density of bacteria and fungi per cubic meter of air in the samples collected around the processing facilities of the biocomposting plant in Sanandaj City was higher than the microbial standard for inhaled air.

Airborne asbestos in public buildings

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

Chesson, J.; Hatfield, J.; Schultz, B.

The U.S. Environmental Protection Agency sampled air in 49 government-owned buildings (six buildings with no asbestos-containing material, six buildings with asbestos-containing material in generally good condition, and 37 buildings with damaged asbestos-containing material). This is the most comprehensive study to date of airborne asbestos levels in U.S. public buildings during normal building activities. The air outside each building was also sampled. Air samples were analyzed by transmission electron microscopy using a direct transfer preparation technique. The results show an increasing trend in average airborne asbestos levels; outdoor levels are lowest and levels in buildings with damaged asbestos-containing material are highest.more » However, the measured levels and the differences between indoors and outdoors and between building categories are small in absolute magnitude. Comparable studies from Canada and the UK, although differing in their estimated concentrations, also conclude that while airborne asbestos levels may be elevated in buildings that contain asbestos, levels are generally low. This conclusion does not eliminate the possibility of higher airborne asbestos levels during maintenance or renovation that disturbs the asbestos-containing material.« less

Vertical profile of elemental concentrations in aerosol particles in the Bermuda area during GCE/CASE/WATOX

NASA Astrophysics Data System (ADS)

Ennis, G.; Sievering, H.

1990-06-01

During the 1988 Global Change Expedition/Coordinated Air-Sea Experiment/Western Atlantic Ocean Experiment (GCE/CASE/WATOX) joint effort, research was conducted to determine elemental concentrations in atmospheric aerosol particles near Bermuda, to construct a three-level (15, 150, and 2600 m ASL) vertical profile of these concentrations, and to ascertain the source of the particles. Samples were collected by the NOAA King Air aircraft and NOAA ship Mt. Mitchell on July 24-28, 1988. Concentration determinations were made for 16 elements through the use of an X ray fluorescence instrument designed for analysis of small-mass samples. A layering effect was found; concentrations of several elements at 150 m were more than twice their respective concentrations at 15 m and 2600 m. Enrichment factors, V/Mn ratio, and correlations between concentrations suggest a Saharan mineral source, despite air mass back trajectories that show no direct continental input for up to 10 days prior to sample collection. Estimated total mineral aerosol concentrations at 15 m, 150 m, and 2600 m are 1.5, 4.1, and 2.1 μg m-3.

A single-blind controlled study of electrocautery and ultrasonic scalpel smoke plumes in laparoscopic surgery.

PubMed

Fitzgerald, J Edward F; Malik, Momin; Ahmed, Irfan

2012-02-01

Surgical smoke containing potentially carcinogenic and irritant chemicals is an inevitable consequence of intraoperative energized dissection. Different energized dissection methods have not been compared directly in human laparoscopic surgery or against commonly encountered pollutants. This study undertook an analysis of carcinogenic and irritant volatile hydrocarbon concentrations in electrocautery and ultrasonic scalpel plumes compared with cigarette smoke and urban city air control samples. Once ethical approval was obtained, gas samples were aspirated from the peritoneal cavity after human laparoscopic intraabdominal surgery solely using either electrocautery or ultrasonic scalpels. All were adsorbed in Tenax tubes and concentrations of carcinogenic or irritant volatile hydrocarbons measured by gas chromatography. The results were compared with cigarette smoke and urban city air control samples. The analyzing laboratory was blinded to sample origin. A total of 10 patients consented to intraoperative gas sampling in which only one method of energized dissection was used. Six carcinogenic or irritant hydrocarbons (benzene, ethylbenzene, styrene, toluene, heptene, and methylpropene) were identified in one or more samples. With the exception of styrene (P = 0.016), a nonsignificant trend toward lower hydrocarbon concentrations was observed with ultrasonic scalpel use. Ultrasonic scalpel plumes had significantly lower hydrocarbon concentrations than cigarette smoke, with the exception of methylpropene (P = 0.332). No significant difference was observed with city air. Electrocautery samples contained significantly lower hydrocarbon concentrations than cigarette smoke, with the exception of toluene (P = 0.117) and methyl propene (P = 0.914). Except for toluene (P = 0.028), city air showed no significant difference. Both electrocautery and ultrasonic dissection are associated with significantly lower concentrations of the most commonly detected carcinogenic and irritant hydrocarbons than cigarette smoke. A nonsignificant trend toward lower hydrocarbon concentrations was seen with ultrasonic scalpel dissection compared with diathermy. The contamination levels in city air were largely comparable with those seen after ultrasonic scalpel use. Although hydrocarbon concentrations are low, cumulative exposures may increase health risks. Where concerns arise, ultrasonic scalpel dissection may be preferable.

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.

Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms.

PubMed

Marinozzi, Franco; Bini, Fabiano; Marinozzi, Andrea; Zuppante, Francesca; De Paolis, Annalisa; Pecci, Raffaella; Bedini, Rossella

2013-01-01

Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a) gray levels produced by the bone x-ray absorption, b) the portions of the image occupied by air and c) voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

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.

Seasonal changes in ground-water quality and ground-water levels and directions of ground-water movement in southern Elmore County, southwestern Idaho, including Mountain Home Air Force Base, 1990-1991

USGS Publications Warehouse

Young, H.W.; Parliman, D.J.; Jones, Michael L.

1992-01-01

The study area is located in southern Elmore County, southwestern Idaho, and includes the Mountain Home Air Force Base located approximately 10 mi southwest of the city of Mountain Home. Chemical analyzes have been made periodically since the late 1940's on water samples from supply wells on the Air Force Base. These analyses indicate increases in specific conductance and in concentrations of nitrogen compounds, chloride, and sulfate. The purposes of this report, which was prepared in cooperation with the Department of the Air Force, are to describe the seasonal changes in water quality and water levels and to depict the directions of ground-water movement in the regional aquifer system and perched-water zones. Although data presented in this report are from both the regional ground-water system and perched-water zones, the focus is on the regional system. A previous study by the U.S. Geological Survey (Parliman and Young, 1990) describes the areal changes in water quality and water levels during the fall of 1989. During March, July, and October 1990, 141 wells were inventoried and depth to water was measured. Continuous water-level recorders were installed on 5 of the wells and monthly measurements of depth to water were made in 17 of the wells during March 1990 through February 1991. Water samples from 33 wells and 1 spring were collected during the spring and fall of 1990 for chemical analyses. Samples also were collected monthly from 11 of those wells during April to September 1990 (table 1). Selected well-construction and water-use data and measurements of depth to water for 141 wells are given in table 2 (separated sheets in envelope). Directions of ground-water movement and selected hydrographs showing seasonal fluctuations of water levels in the regional ground-water system and perched-water zones are shown on sheet 2. Changes in water levels in the regional ground-water system during March to October 1990 are shown on sheet 2.

Spectral analysis of meteorites ablated in a wind tunnel

NASA Astrophysics Data System (ADS)

Drouard, A.; Vernazza, P.; Loehle, S.; Gattacceca, J.; Zander, T.; Eberhart, M.; Meindl, A.; Oefele, R.; Vaubaillon, J.; Colas, F.

2017-09-01

Recently and for the very first time, experiments simulating vaporization of a meteorite sample were performed in a wind tunnel near Stuttgart with the specific aim to record emission spectra of the vaporized material. Using a high enthalpy air plasma flow for modeling an equivalent air friction of an entry speed of about 10 km/s, three meteorite types (H, CM and HED) and two meteoritical analogues (basalt and argillite) were ablated and high resolution spectra were recorded simultaneously. After the identification of all atomic lines, we per- formed a detailed study of our spectra using two approaches: (i) by direct comparison of multiplet in- tensities between the samples and (ii) by computation of a synthetic spectrum to constrain some physical parameters (temperature, elemental abundance). Finally, we compared our results to the elemental composition of our samples and we determined how much compositional information can be retrieved for a given meteor using visible sectroscopy.

MO-D-213-07: RadShield: Semi- Automated Calculation of Air Kerma Rate and Barrier Thickness

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

DeLorenzo, M; Wu, D; Rutel, I

2015-06-15

Purpose: To develop the first Java-based semi-automated calculation program intended to aid professional radiation shielding design. Air-kerma rate and barrier thickness calculations are performed by implementing NCRP Report 147 formalism into a Graphical User Interface (GUI). The ultimate aim of this newly created software package is to reduce errors and improve radiographic and fluoroscopic room designs over manual approaches. Methods: Floor plans are first imported as images into the RadShield software program. These plans serve as templates for drawing barriers, occupied regions and x-ray tube locations. We have implemented sub-GUIs that allow the specification in regions and equipment for occupancymore » factors, design goals, number of patients, primary beam directions, source-to-patient distances and workload distributions. Once the user enters the above parameters, the program automatically calculates air-kerma rate at sampled points beyond all barriers. For each sample point, a corresponding minimum barrier thickness is calculated to meet the design goal. RadShield allows control over preshielding, sample point location and material types. Results: A functional GUI package was developed and tested. Examination of sample walls and source distributions yields a maximum percent difference of less than 0.1% between hand-calculated air-kerma rates and RadShield. Conclusion: The initial results demonstrated that RadShield calculates air-kerma rates and required barrier thicknesses with reliable accuracy and can be used to make radiation shielding design more efficient and accurate. This newly developed approach differs from conventional calculation methods in that it finds air-kerma rates and thickness requirements for many points outside the barriers, stores the information and selects the largest value needed to comply with NCRP Report 147 design goals. Floor plans, parameters, designs and reports can be saved and accessed later for modification and recalculation. We have confirmed that this software accurately calculates air-kerma rates and required barrier thicknesses for diagnostic radiography and fluoroscopic rooms.« less

Investigation of molecular metabolites in expired air of healthy man in condition of long-term isolation in hermetical confined environment

NASA Astrophysics Data System (ADS)

Tsarkov, Dmitriy; Mardanov, Robert; Markin, Andrey; Moukhamedieva, Lana

Investigation of intermediary metabolites, produced in cells, in expired air of healthy man is directed on determination of molecular markers which are reflecting normal physiological pro-cesses in an organism, as well as on determination and validation of biomarkers for objective screening and non-invasive prenosological diagnostics of disorders in metabolic processes caused by negative effect of live environment. Investigation of influence of long-term isolation in her-metical confined environment on composition of healthy human expired air was made during experiment with 105 days isolation in condition of controlled environment and standard food ra-tion. Expired air samples were analyzed on gas chromatograph associated with the quadrupole mass spectrometer. The investigation results show that at rest hydroxy ketones, mostly 1-hydroxy-prorapanone-2 (acetol), aldehydes (decenal, benzaldehyde), acetophenone, phenol and fatty acids were determined. After physical performance (oxidative stress) the content of ke-tones (heptanone-2, heptanone-3), phenol, determined aldehydes (decenal, octadecenal) and acetol in expired air of volunteers decreased. It can be concerned with prevailing of alternative -methylglyoxalic metabolic pathway and caused by oxidative stress. Analysis of expired air samples taken on 30, 60 and 90 day of isolation showed that in conditions of long-term iso-lation concentration of heptanone-2, heptanone-3, 2,3-butadione, acetol, furanones, aldehydes (decenal, benzaldehyde) and acetophenone is increasing while concentration of phenol and fatty acids is decreasing as compared to samples taken before isolation. It was shown that dynamics of concentration of saturated hydrocarbons in expired air can be informative marker for estima-tion of organism response to oxidative stress, while the level of acetol can be used as indicator of man's training status, validity of exercise load and as a marker of hypoxic state.

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.

Fungal monitoring of the indoor air of the Museo de La Plata Herbarium, Argentina.

PubMed

Mallo, Andrea C; Elíades, Lorena A; Nitiu, Daniela S; Saparrat, Mario C N

Biological agents, such as fungal spores in the air in places where scientific collections are stored, can attack and deteriorate them. The aim of this study was to gather information on the indoor air quality of the Herbarium of Vascular Plants of the Museo de Ciencias Naturales de La Plata, Argentina, in relation to fungal propagules and inert particles. This study was made using a volumetric system and two complementary sampling methods: (1) a non-viable method for direct evaluation, and (2) a viable method by culture for viable fungal propagules. The non-viable method led to ten spore morphotypes being found from related fungal sources. A total of 4401.88spores/m 3 and 32135.18 inert suspended particles/m 3 were recorded. The viable method led to the finding of nine fungal taxa as viable spores that mostly belonged to anamorphic forms of Ascomycota, although the pigmented yeast Rhodotorula F.C. Harrison (Basidiomycota) was also found. A total count of 40,500fungal CFU/m 3 air was estimated for all the sites sampled. Both the non-viable and viable sampling methods were necessary to monitor the bio-aerosol load in the La Plata Herbarium. The indoor air of this institution seems to be reasonably adequate for the conservation of vascular plants due to the low indoor/outdoor index, low concentrations of air spores, and/or lack of indicators of moisture problems. Copyright © 2016 Asociación Española de Micología. Publicado por Elsevier España, S.L.U. All rights reserved.

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

Characterization of marine aerosol for assessment of human exposure to brevetoxins.

PubMed

Cheng, Yung Sung; Zhou, Yue; Irvin, Clinton M; Pierce, Richard H; Naar, Jerome; Backer, Lorraine C; Fleming, Lora E; Kirkpatrick, Barbara; Baden, Dan G

2005-05-01

Red tides in the Gulf of Mexico are commonly formed by the fish-killing dinoflagellate Karenia brevis, which produces nine potent polyether brevetoxins (PbTxs). Brevetoxins can be transferred from water to air in wind-powered white-capped waves. Inhalation exposure to marine aerosol containing brevetoxins causes respiratory symptoms. We describe detailed characterization of aerosols during an epidemiologic study of occupational exposure to Florida red tide aerosol in terms of its concentration, toxin profile, and particle size distribution. This information is essential in understanding its source, assessing exposure to people, and estimating dose of inhaled aerosols. Environmental sampling confirmed the presence of brevetoxins in water and air during a red tide exposure period (September 2001) and lack of significant toxin levels in the water and air during an unexposed period (May 2002). Water samples collected during a red tide bloom in 2001 showed moderate-to-high concentrations of K. brevis cells and PbTxs. The daily mean PbTx concentration in water samples ranged from 8 to 28 microg/L from 7 to 11 September 2001; the daily mean PbTx concentration in air samples ranged from 1.3 to 27 ng/m(3). The daily aerosol concentration on the beach can be related to PbTx concentration in water, wind speed, and wind direction. Personal samples confirmed human exposure to red tide aerosols. The particle size distribution showed a mean aerodynamic diameter in the size range of 6-12 microm, with deposits mainly in the upper airways. The deposition pattern correlated with the observed increase of upper airway symptoms in healthy lifeguards during the exposure periods.

SCANNING VOLTA POTENTIALS MEASUREMENTS OF METALS IN IRRADIATED AIR.

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

ISAACS, H.S.; ADZIC, G.; AND ENERGY SCIENCES AND TECHNOLOGY DEPARTMENT

2000-10-22

A method for direct dc measurement of the Volta potential is presented. High intensity synchrotron x-ray beams were used to locally irradiate the atmosphere adjacent to the metal surface and produce a conducting path between a sample and a reference probe. The direct measurements of potential in the ionized air could be made at probe heights of around 1 mm compared to less than 0.1 mm for the Kelvin probe. The measurements were similar to traditional Kelvin probe measurements, but had a poorer spatial resolution. In contrast to the Kelvin probe methods, the approach described allows observation of the currentmore » as a function of impressed voltage. Methods to improve the special resolution of the technique and applications to corrosion under coating will be presented.« less

Analytical results from ground-water sampling using a direct-push technique at the Dover National Test Site, Dover Air Force Base, Delaware, June-July 2001

USGS Publications Warehouse

Guertal, William R.; Stewart, Marie; Barbaro, Jeffrey R.; McHale, Timthoy J.

2004-01-01

A joint study by the Dover National Test Site and the U.S. Geological Survey was conducted from June 27 through July 18, 2001 to determine the spatial distribution of the gasoline oxygenate additive methyl tert-butyl ether and selected water-quality constituents in the surficial aquifer underlying the Dover National Test Site at Dover Air Force Base, Delaware. The study was conducted to support a planned enhanced bio-remediation demonstration and to assist the Dover National Test Site in identifying possible locations for future methyl tert-butyl ether remediation demonstrations. This report presents the analytical results from ground-water samples collected during the direct-push ground-water sampling study. A direct-push drill rig was used to quickly collect 115 ground-water samples over a large area at varying depths. The ground-water samples and associated quality-control samples were analyzed for volatile organic compounds and methyl tert-butyl ether by the Dover National Test Site analytical laboratory. Volatile organic compounds were above the method reporting limits in 59 of the 115 ground-water samples. The concentrations ranged from below detection limits to maximum values of 12.4 micrograms per liter of cis-1,2-dichloroethene, 1.14 micrograms per liter of trichloroethene, 2.65 micrograms per liter of tetrachloroethene, 1,070 micrograms per liter of methyl tert-butyl ether, 4.36 micrograms per liter of benzene, and 1.8 micrograms per liter of toluene. Vinyl chloride, ethylbenzene, p,m-xylene, and o-xylene were not detected in any of the samples collected during this investigation. Methyl tert-butyl ether was detected in 47 of the 115 ground-water samples. The highest methyl tert-butyl ether concentrations were found in the surficial aquifer from -4.6 to 6.4 feet mean sea level, however, methyl tert-butyl ether was detected as deep as -9.5 feet mean sea level. Increased methane concentrations and decreased dissolved oxygen concentrations were found in samples that contained methyl tert-butyl ether.

Firn-air Properties and Influences at the West Antarctic Ice Sheet Divide

NASA Astrophysics Data System (ADS)

Battle, M. O.; Severinghaus, J. P.; Montzka, S. A.; Sofen, E. D.; Tans, P. P.

2007-12-01

In December 2005, we collected samples of firn air from a pair of dedicated boreholes drilled at the West Antarctic Ice Sheet Divide (WAIS-D), immediately adjacent to the WAIS-D deep ice coring effort currently underway at 79° 28'S, 112° 7'W at an elevation of ~1800m. The site is characterized by moderate temperatures (annual mean of -31°C) and moderate accumulation (24 cm/yr ice-equivalent). These samples were analyzed for a wide variety of atmospheric species by laboratories at the Scripps Institution of Oceanography, NOAA-ESRL, University of Colorado/INSTAAR, UC Irvine and Penn. State University. In this presentation, we focus on general properties of the firn air at this site and the influences on its composition, as inferred from concentration data for CO2, CH4, and a range of halogenated species, as well as the stable isotope ratios of N2 and several noble gases. Preliminary analyses indicate the presence of a shallow convective zone (a few meters or less), a diffusive region extending down to roughly 65m and a lock-in zone from 65m to the firn-ice transition at 76.5m. There is also evidence of a thermally-driven seasonal cycle in composition in the upper 25m of the firn. Modeling studies indicate that the accumulation rate at this site is low enough that the downward advection of air accompanying firn compression has a very small influence on the firn air profile. Air at the bottom of the diffusive column has a CO2-based age of 10-15 years (depending on the definition of "mean age"), while the air at the firn-ice transition is ~38 years old. Concentrations of halogenated species in the samples collected imply atmospheric histories that are generally consistent with those derived from direct atmospheric measurements and from firn air collected at other sites. Additional properties of the air, and their controlling processes will also be presented.

Atmospheric pressure resistive barrier air plasma jet induced bacterial inactivation in aqueous environment

NASA Astrophysics Data System (ADS)

Thiyagarajan, Magesh; Sarani, Abdollah; Gonzales, Xavier

2013-03-01

An atmospheric pressure resistive barrier air plasma jet is designed to inactivate bacteria in aqueous media in direct and indirect exposure modes of treatment. The resistive barrier plasma jet is designed to operate at both dc and standard 50-60 Hz low frequency ac power input and the ambient air at 50% humidity level was used as the operating gas. The voltage-current characteristics of the plasma jet were analyzed and the operating frequency of the discharge was measured to be 20 kHz and the plasma power was measured to be 26 W. The plasma jet rotational temperatures (Trot) are obtained from the optical emission spectra, from the N2C-B(2+) transitions by matching the experimental spectrum results with the Spectra Air (SPECAIR) simulation spectra. The reactive oxygen and nitrogen species were measured using optical emission spectroscopy and gas analyzers, for direct and indirect treatment modes. The nitric oxides (NO) were observed to be the predominant long lived reactive nitrogen species produced by the plasma. Three different bacteria including Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), and Neisseria meningitidis (Gram-negative) were suspended in an aqueous media and treated by the resistive barrier air plasma jet in direct and indirect exposure modes. The results show that a near complete bacterial inactivation was achieved within 120 s for both direct and indirect plasma treatment of S. aureus and E. coli bacteria. Conversely, a partial inactivation of N. meningitidis was observed by 120 s direct plasma exposure and insignificant inactivation was observed for the indirect plasma exposure treatment. Plasma induced shifts in N. meningitidis gene expression was analyzed using pilC gene expression as a representative gene and the results showed a reduction in the expression of the pilC gene compared to untreated samples suggesting that the observed protection against NO may be regulated by other genes.

The advantages and disadvantages of centralized control of air power at operational level

NASA Astrophysics Data System (ADS)

Arisoy, Uǧur

2014-05-01

People do not want to see and hear a war. In today's world, if war is inevitable, the use of air power is seen as the preferable means of conducting operations instead of financially burdensome land battles which are more likely to cause heavy loss of life. The use of Air Power has gained importance in NATO operations in the Post-Cold War era. For example, air power has undertaken a decisive role from the beginning to the end of the operation in Libya. From this point of view, the most important issue to consider is how to direct air power more effectively at operational level. NATO's Core JFAC (Joint Force Air Command) was established in 2012 to control joint air power at operational level from a single center. US had experienced JFAC aproach in the Operation Desert Storm in 1991. UK, France, Germany, Italy and Spain are also directing their air power from their JFAC structures. Joint air power can be directed from a single center at operational level by means of JFAC. JFAC aproach provides complex planning progress of Air Power to be controled faster in a single center. An Air Power with a large number of aircrafts, long range missiles of cutting-edge technology may have difficulties in achieving results unless directed effectively. In this article, directing air power more effectively at operational level has been studied in the framework of directing air power from a single center carried out by SWOT analysis technique. "Directing Air Power at operational level from a single center similar to JFAC-like structure" is compared with "Directing Air Power at operational level from two centers similar to AC (Air Command) + CAOC (Combined Air Operations Center) structure" As a result of this study, it is assessed that directing air power at operational level from a single center would bring effectiveness to the air campaign. The study examines directing air power at operational level. Developments at political, strategic and tactical levels have been ignored.

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.

Fluidics platform and method for sample preparation and analysis

DOEpatents

Benner, W. Henry; Dzenitis, John M.; Bennet, William J.; Baker, Brian R.

2014-08-19

Herein provided are fluidics platform and method for sample preparation and analysis. The fluidics platform is capable of analyzing DNA from blood samples using amplification assays such as polymerase-chain-reaction assays and loop-mediated-isothermal-amplification assays. The fluidics platform can also be used for other types of assays and analyzes. In some embodiments, a sample in a sealed tube can be inserted directly. The following isolation, detection, and analyzes can be performed without a user's intervention. The disclosed platform may also comprises a sample preparation system with a magnetic actuator, a heater, and an air-drying mechanism, and fluid manipulation processes for extraction, washing, elution, assay assembly, assay detection, and cleaning after reactions and between samples.

The method for on-site determination of trace concentrations of methyl mercaptan and dimethyl sulfide in air using a mobile mass spectrometer with atmospheric pressure chemical ionization, combined with a fast enrichment/separation system.

PubMed

Kudryavtsev, Andrey S; Makas, Alexey L; Troshkov, Mikhail L; Grachev, Mikhail А; Pod'yachev, Sergey P

2014-06-01

A method for fast simultaneous on-site determination of methyl mercaptan and dimethyl sulfide in air was developed. The target compounds were actively collected on silica gel, followed by direct flash thermal desorption, fast separation on a short chromatographic column and detection by means of mass spectrometer with atmospheric pressure chemical ionization. During the sampling of ambient air, water vapor was removed with a Nafion selective membrane. A compact mass spectrometer prototype, which was designed earlier at Trofimuk Institute of Petroleum Geology and Geophysics, was used. The minimization of gas load of the atmospheric pressure ion source allowed reducing the power requirements and size of the vacuum system and increasing its ruggedness. The measurement cycle is about 3 min. Detection limits in a 0.6 L sample are 1 ppb for methyl mercaptan and 0.2 ppb for dimethyl sulfide. Copyright © 2014 Elsevier B.V. All rights reserved.

Robust and Rapid Air-Borne Odor Tracking without Casting1,2,3

PubMed Central

Bhattacharyya, Urvashi

2015-01-01

Abstract Casting behavior (zigzagging across an odor stream) is common in air/liquid-borne odor tracking in open fields; however, terrestrial odor localization often involves path selection in a familiar environment. To study this, we trained rats to run toward an odor source in a multi-choice olfactory arena with near-laminar airflow. We find that rather than casting, rats run directly toward an odor port, and if this is incorrect, they serially sample other sources. This behavior is consistent and accurate in the presence of perturbations, such as novel odors, background odor, unilateral nostril stitching, and turbulence. We developed a model that predicts that this run-and-scan tracking of air-borne odors is faster than casting, provided there are a small number of targets at known locations. Thus, the combination of best-guess target selection with fallback serial sampling provides a rapid and robust strategy for finding odor sources in familiar surroundings. PMID:26665165

Molecular composition of boreal forest aerosol from Hyytiälä, Finland, using ultrahigh resolution mass spectrometry.

PubMed

Kourtchev, Ivan; Fuller, Stephen; Aalto, Juho; Ruuskanen, Taina M; McLeod, Matthew W; Maenhaut, Willy; Jones, Rod; Kulmala, Markku; Kalberer, Markus

2013-05-07

Organic compounds are important constituents of fine particulate matter (PM) in the troposphere. In this study, we applied direct infusion nanoelectrospray (nanoESI) ultrahigh resolution mass spectrometry (UHR-MS) and liquid chromatography LC/ESI-UHR-MS for the analysis of the organic fraction of PM1 aerosol samples collected over a two week period at a boreal forest site (Hyytiälä), southern Finland. Elemental formulas (460-730 in total) were identified with nanoESI-UHR-MS in the negative ionization mode and attributed to organic compounds with a molecular weight below 400. Kendrick Mass Defect and Van Krevelen approaches were used to identify compound classes and mass distributions of the detected species. The molecular composition of the aerosols strongly varied between samples with different air mass histories. An increased number of nitrogen, sulfur, and highly oxygenated organic compounds was observed during the days associated with continental air masses. However, the samples with Atlantic air mass history were marked by a presence of homologous series of unsaturated and saturated C12-C20 fatty acids suggesting their marine origin. To our knowledge, we show for the first time that the highly detailed chemical composition obtained from UHR-MS analyses can be clearly linked to meteorological parameters and trace gases concentrations that are relevant to atmospheric oxidation processes. The additional LC/ESI-UHR-MS analysis revealed 29 species, which were mainly attributed to oxidation products of biogenic volatile compounds BVOCs (i.e., α,β-pinene, Δ3-carene, limonene, and isoprene) supporting the results from the direct infusion analysis.

Quantification of fluorine traces in solid samples using CaF molecular emission bands in atmospheric air Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Alvarez-Llamas, C.; Pisonero, J.; Bordel, N.

2016-09-01

Direct solid determination of trace amounts of fluorine using Laser-Induced Breakdown Spectroscopy (LIBS) is a challenging task due to the low excitation efficiency of this element. Several strategies have been developed to improve the detection capabilities, including the use of LIBS in a He atmosphere to enhance the signal to background ratios of F atomic emission lines. An alternative method is based on the detection of the molecular compounds that are formed with fluorine in the LIBS plasma. In this work, the detection of CaF molecular emission bands is investigated to improve the analytical capabilities of atmospheric air LIBS for the determination of fluorine traces in solid samples. In particular, Cu matrix samples containing different fluorine concentration (between 50 and 600 μg/g), and variable amounts of Ca, are used to demonstrate the linear relationships between CaF emission signal and F concentration. Limits of detection for fluorine are improved by more than 1 order of magnitude using CaF emission bands versus F atomic lines, in atmospheric-air LIBS. Furthermore, a toothpaste powder sample is used to validate this analytical method. Good agreement is observed between the nominal and the predicted fluorine mass-content.

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).

Air breathing direct methanol fuel cell

DOEpatents

Ren, Xiaoming

2002-01-01

An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source.

Slaughterhouses Fungal Burden Assessment: A Contribution for the Pursuit of a Better Assessment Strategy

PubMed Central

Viegas, Carla; Faria, Tiago; dos Santos, Mateus; Carolino, Elisabete; Sabino, Raquel; Quintal Gomes, Anita; Viegas, Susana

2016-01-01

In slaughterhouses, the biological risk is present not only from the direct or indirect contact with animal matter, but also from the exposure to bioaerosols. Fungal contamination was already reported from the floors and walls of slaughterhouses. This study intends to assess fungal contamination by cultural and molecular methods in poultry, swine/bovine and large animal slaughterhouses. Air samples were collected through an impaction method, while surface samples were collected by the swabbing method and subjected to further macro- and micro-scopic observations. In addition, we collected air samples using the impinger method in order to perform real-time quantitative PCR (qPCR) amplification of genes from specific fungal species, namely A. flavus, A. fumigatus and A. ochraceus complexes. Poultry and swine/bovine slaughterhouses presented each two sampling sites that surpass the guideline of 150 CFU/m3. Scopulariopsis candida was the most frequently isolated (59.5%) in poultry slaughterhouse air; Cladosporium sp. (45.7%) in the swine/bovine slaughterhouse; and Penicillium sp. (80.8%) in the large animal slaughterhouse. Molecular tools successfully amplified DNA from the A. fumigatus complex in six sampling sites where the presence of this fungal species was not identified by conventional methods. This study besides suggesting the indicators that are representative of harmful fungal contamination, also indicates a strategy as a protocol to ensure a proper characterization of fungal occupational exposure. PMID:27005642

Human sensory response to acetone/air mixtures.

PubMed

Salthammer, T; Schulz, N; Stolte, R; Uhde, E

2016-10-01

The release of organic compounds from building products may influence the perceived air quality in the indoor environment. Consequently, building products are assessed for chemical emissions and for the acceptability of emitted odors. A procedure for odor evaluations in test chambers is described by the standard ISO 16000-28. A panel of eight or more trained subjects directly determines the perceived intensity Π (unit pi) of an air sample via diffusers. For the training of the panelists, a comparative Π-scale is applied. The panelists can use acetone/air mixtures in a concentration range between 20 mg/m(3) (0 pi) and 320 mg/m(3) (15 pi) as reference. However, the training and calibration procedure itself can substantially contribute to the method uncertainty. This concerns the assumed odor threshold of acetone, the variability of panelist responses, and the analytical determination of acetone concentrations in air with online methods as well as the influence of the diffuser geometry and the airflow profile. © 2015 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Particulate Matter Levels in Ambient Air Adjacent to Industrial Area

NASA Astrophysics Data System (ADS)

Mohamed, R. M. S. R.; Nizam, N. M. S.; Al-Gheethi, A. A.; Lajis, A.; Kassim, A. H. M.

2016-07-01

Air quality in the residential areas adjacent to the industrial regions is of great concern due to the association with human health risks. In this work, the concentrations of particulate matter (PM10) in the ambient air of UTHM campus was investigated tostudy the air qualityand their compliance to the Malaysian Ambient Air Quality Guidelines (AAQG). The PM10 samples were taken over 24 hours from the most significant area at UTHM including Stadium, KolejKediamanTunDr. Ismail (KKTDI) and MakmalBahan. The meteorological parameters; temperature, relative humidity, wind speed and wind direction as well as particulate matterwere estimated by using E-Sampler Particulate Matter (PM10) Collector. The highest concentrations of PM10 (55.56 µg/m3) was recorded at MakmalBahan during the working and weekend days. However, these concentrations are less than 150 pg/m3. It can be concluded that although UTHM is surrounded by the industrial area, the air quality in the campus still within the standards limits.

Comparison of culture media for the recovery of airborne yeast in wineries.

PubMed

Ocón, E; Garijo, P; Santamaría, P; López, R; Olarte, C; Gutiérrez, A R; Sanz, S

2013-09-01

The direct air sampling impaction method on agar was evaluated using aerobiocollectors for the recovery of yeasts present in the winery air. Three culture media with different composition and specificity were studied. In addition, a resuscitation phase was included before the culture in the specificity medium [in the case of the Dekkera-Brettanomyces Differential Medium (DBDM) medium]. Sampling was conducted at different times of the year and in different parts of the wineries, which were different in age and design. Both the Chloramphenicol Glucose Agar (CGA) and Agar Lysine AL media recovered yeasts from the air without any prior resuscitation phase. CGA was able to recover a higher number of colony-forming units of yeasts than the other media. Consequently, to estimate the number of yeasts present in winery air, the best choice of medium would be CGA. The AL medium permitted the growth of the greatest range of genera and species. If the aim is to study the diversity of yeasts present in the air, the most suitable medium is AL. Neither CGA nor AL proved suitable for recovering yeasts of the Brettanomyces genus. The DBDM medium was the only one which provided sufficient specificity for their recovery and identification from the air, although their special characteristics made a prior protocol of resuscitation necessary. © 2013 The Society for Applied Microbiology.

Appraising city-scale pollution monitoring capabilities of multi-satellite datasets using portable pollutant monitors

NASA Astrophysics Data System (ADS)

Aliyu, Yahaya A.; Botai, Joel O.

2018-04-01

The retrieval characteristics for a city-scale satellite experiment was explored over a Nigerian city. The study evaluated carbon monoxide and aerosol contents in the city atmosphere. We utilized the MSA Altair 5× gas detector and CW-HAT200 particulate counter to investigate the city-scale monitoring capabilities of satellite pollution observing instruments; atmospheric infrared sounder (AIRS), measurement of pollution in the troposphere (MOPITT), moderate resolution imaging spectroradiometer (MODIS), multi-angle imaging spectroradiometer (MISR) and ozone monitoring instrument (OMI). To achieve this, we employed the Kriging interpolation technique to collocate the satellite pollutant estimations over 19 ground sample sites for the period of 2015-2016. The portable pollutant devices were validated using the WHO air filter sampling model. To determine the city-scale performance of the satellite datasets, performance indicators: correlation coefficient, model efficiency, reliability index and root mean square error, were adopted as measures. The comparative analysis revealed that MOPITT carbon monoxide (CO) and MODIS aerosol optical depth (AOD) estimates are the appropriate satellite measurements for ground equivalents in Zaria, Nigeria. Our findings were within the acceptable limits of similar studies that utilized reference stations. In conclusion, this study offers direction to Nigeria's air quality policy organizers about available alternative air pollution measurements for mitigating air quality effects within its limited resource environment.

Air Pollution Source/receptor Relationships in South Coast Air Basin, CA

NASA Astrophysics Data System (ADS)

Gao, Ning

This research project includes the application of some existing receptor models to study the air pollution source/receptor relationships in the South Coast Air Basin (SoCAB) of southern California, the development of a new receptor model and the testing and the modifications of some existing models. These existing receptor models used include principal component factor analysis (PCA), potential source contribution function (PSCF) analysis, Kohonen's neural network combined with Prim's minimal spanning tree (TREE-MAP), and direct trilinear decomposition followed by a matrix reconstruction. The ambient concentration measurements used in this study are a subset of the data collected during the 1987 field exercise of Southern California Air Quality Study (SCAQS). It consists of a number of gaseous and particulate pollutants analyzed from samples collected by SCAQS samplers at eight sampling sites, Anaheim, Azusa, Burbank, Claremont, Downtown Los Angeles, Hawthorne, Long Beach, and Rubidoux. Based on the information of emission inventories, meteorology and ambient concentrations, this receptor modeling study has revealed mechanisms that influence the air quality in SoCAB. Some of the mechanisms affecting the air quality in SoCAB that were revealed during this study include the following aspects. The SO_2 collected at sampling sites is mainly contributed by refineries in the coastal area and the ships equipped with oil-fired boilers off shore. Combustion of fossil fuel by automobiles dominates the emission of NO_{rm x} that is subsequently transformed and collected at sampling sites. Electric power plants also contribute HNO_3 to the sampling sites. A large feedlot in the eastern region of SoCAB has been identified as the major source of NH_3. Possible contributions from other industrial sources such as smelters and incinerators were also revealed. The results of this study also suggest the possibility of DMS (dimethylsulfide) and NH_3 emissions from off-shore sediments that have been contaminated by waste sludge disposal. The study also discovered that non-anthropogenic sources account for the observation of many chemical components being brought to the sampling sites, such as seasalt particles, soil particles, and Cl emission from Mojave Desert. The potential and limitation of the receptor models have been evaluated and some modifications have been made to improve the value of the models. A source apportionment method has been developed based on the application results of the potential source contribution function (PSCF) analysis.

Gaseous exchange of polycyclic aromatic hydrocarbons across the air-water interface of lower Chesapeake Bay

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

Gustafson, K.E.; Dickhut, R.M.

1995-12-31

The gaseous exchange fluxes of polycyclic aromatic hydrocarbons (PAHs) across the air-water interface of lower Chesapeake Bay were determined using a modified two-film exchange model. Sampling covered the period January 1994 to June 1995 for five sites on lower Chesapeake Bay ranging from rural to urban and highly industrialized. Simultaneous air and water samples were collected and the atmospheric gas phase and water column dissolved phase analyzed via GC/MS for 17 PAHs. The direction and magnitude of flux for each PAH was calculated using Henry`s law constants, hydrological and meteorological parameters, Temperature was observed to be an important environmental factormore » in determining both the direction and magnitude of PAH gas exchange. Nonetheless, wind speed significantly impacts mass transfer coefficients, and therefore was found to control the magnitude of flux. Spatial and temporal variation of PAH gaseous exchange fluxes were examined. Fluxes were determined to be both into and out of Chesapeake Bay. The range of gas exchange fluxes ({minus}560 to 600{micro}g/M{sup 2}*Mo) is of the same order to 10X greater than atmospheric wet and dry depositional fluxes to lower Chesapeake Bay. The results of this study support the hypothesis that gas exchange is a major transport process affecting the net loadings of PAHs in lower Chesapeake Bay.« less

Concentrations of trace elements and PCDD/Fs around a municipal solid waste incinerator in Girona (Catalonia, Spain). Human health risks for the population living in the neighborhood.

PubMed

Rovira, Joaquim; Nadal, Martí; Schuhmacher, Marta; Domingo, José L

2018-07-15

Previously to the modernization of the municipal solid waste incinerator (MSWI) of Campdorà (Girona, Catalonia, Spain) two sampling campaigns (2015 and 2016) were conducted. In each campaign, 8 soil and 4 air samples (PM 10 and total particle phase and gas phase) were collected. The levels of As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Sn, Tl and V, and PCDD/Fs were analysed at different distances and wind directions around the MSWI. Environmental levels of trace elements and PCDD/Fs were used to assess exposure and health risks (carcinogenic and non-carcinogenic) for the population living around the facility. In soils, no significant differences were observed for trace elements and PCDD/Fs between both campaigns. In air, significant higher levels of As, Cd, Co, Mn, Ni, Pb, Tl and V were detected in 2016. Regarding soil levels, only Cd (distances) and As, Cu, Mn, and Ni (wind directions) showed significant differences. No differences were noted in the concentrations of trace elements and PCDD/Fs in air levels with respect to distances and directions to the MSWI. No differences were registered in air levels (elements and PCDD/Fs) between points influenced by MSWI emissions and background point. However some differences in congener profile were noted regarding from where back-trajectories come from (HYSPLIT model results), pointing some influence of Barcelona metropolitan area. The concentrations of trace elements and PCDD/Fs were similar -or even lower- than those reported around other MSWIs in Catalonia and various countries. Non-carcinogenic risks were below the safety limit (HQ<1). In turn, carcinogenic risks due to exposure to trace elements and PCDD/Fs were in acceptable ranges, according to national and international standard regulations. Copyright © 2018 Elsevier B.V. All rights reserved.

Planning for rotorcraft and commuter air transportationn

NASA Technical Reports Server (NTRS)

Stockwell, W. L.; Stowers, J.

1981-01-01

Community planning needs, criteria, and other considerations such as intermodal coordination and regulatory requirements, for rotorcraft and fixed wing commuter air transportation were identified. A broad range of community planning guidelines, issues, and information which can be used to: (1) direct anticipated aircraft technological improvements; (2) assist planners in identifying and evaluating the opportunities and tradeoffs presented by rotorcraft and commuter aircraft options relative to other modes; and (3) increase communication between aircraft technologists and planners for the purpose of on going support in capitalizing on rotorcraft and commuter air opportunities are provided. The primary tool for identifying and analyzing planning requirements was a detailed questionnaire administered to a selected sample of 55 community planners and other involved in planning for helicopters and commuter aviation.

Laser surface texturing of 316L stainless steel in air and water: A method for increasing hydrophilicity via direct creation of microstructures

NASA Astrophysics Data System (ADS)

Razi, Sepehr; Madanipour, Khosro; Mollabashi, Mahmoud

2016-06-01

Laser processing of materials in water contact is sometimes employed for improving the machining, cutting or welding quality. Here, we demonstrate surface patterning of stainless steel grade 316L by nano-second laser processing in air and water. Suitable adjustments of laser parameters offer a variety of surface patterns on the treated targets. Furthermore alterations of different surface features such as surface chemistry and wettability are investigated in various processing circumstances. More than surface morphology, remarkable differences are observed in the surface oxygen content and wettability of the samples treated in air and water at the same laser processing conditions. Mechanisms of the changes are discussed extensively.

14 CFR 380.34a - Substitution of direct air carrier's security or depository agreement.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Substitution of direct air carrier's... Applicable to Charter Operators § 380.34a Substitution of direct air carrier's security or depository agreement. (a) A direct air carrier may substitute its own security agreement and/or depository arrangements...

14 CFR 380.34a - Substitution of direct air carrier's security or depository agreement.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Substitution of direct air carrier's... Applicable to Charter Operators § 380.34a Substitution of direct air carrier's security or depository agreement. (a) A direct air carrier may substitute its own security agreement and/or depository arrangements...

14 CFR 380.34a - Substitution of direct air carrier's security or depository agreement.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Substitution of direct air carrier's... Applicable to Charter Operators § 380.34a Substitution of direct air carrier's security or depository agreement. (a) A direct air carrier may substitute its own security agreement and/or depository arrangements...

14 CFR 380.34a - Substitution of direct air carrier's security or depository agreement.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Substitution of direct air carrier's... Applicable to Charter Operators § 380.34a Substitution of direct air carrier's security or depository agreement. (a) A direct air carrier may substitute its own security agreement and/or depository arrangements...

14 CFR 380.34a - Substitution of direct air carrier's security or depository agreement.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Substitution of direct air carrier's... Applicable to Charter Operators § 380.34a Substitution of direct air carrier's security or depository agreement. (a) A direct air carrier may substitute its own security agreement and/or depository arrangements...

Traffic flow and microbial air contamination in operating rooms at a major teaching hospital in Ghana.

PubMed

Stauning, M T; Bediako-Bowan, A; Andersen, L P; Opintan, J A; Labi, A-K; Kurtzhals, J A L; Bjerrum, S

2018-07-01

Current literature examining the relationship between door-opening rate, number of people present, and microbial air contamination in the operating room is limited. Studies are especially needed from low- and middle-income countries, where the risk of surgical site infections is high. To assess microbial air contamination in operating rooms at a Ghanaian teaching hospital and the association with door-openings and number of people present. Moreover, we aimed to document reasons for door-opening. We conducted active air-sampling using an MAS 100 ® portable impactor during 124 clean or clean-contaminated elective surgical procedures. The number of people present, door-opening rate and the reasons for each door-opening were recorded by direct observation using pretested structured observation forms. During surgery, the mean number of colony-forming units (cfu) was 328 cfu/m 3 air, and 429 (84%) of 510 samples exceeded a recommended level of 180 cfu/m 3 . Of 6717 door-openings recorded, 77% were considered unnecessary. Levels of cfu/m 3 were strongly correlated with the number of people present (P = 0.001) and with the number of door-openings/h (P = 0.02). In empty operating rooms, the mean cfu count was 39 cfu/m 3 after 1 h of uninterrupted ventilation and 52 (51%) of 102 samples exceeded a recommended level of 35 cfu/m 3 . The study revealed high values of intraoperative airborne cfu exceeding recommended levels. Minimizing the number of door-openings and people present during surgery could be an effective strategy to reduce microbial air contamination in low- and middle-income settings. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

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.

Influence of tap water quality and household water use activities on indoor air and internal dose levels of trihalomethanes.

PubMed

Nuckols, John R; Ashley, David L; Lyu, Christopher; Gordon, Sydney M; Hinckley, Alison F; Singer, Philip

2005-07-01

Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre-water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and post-activity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities.

Influence of Tap Water Quality and Household Water Use Activities on Indoor Air and Internal Dose Levels of Trihalomethanes

PubMed Central

Nuckols, John R.; Ashley, David L.; Lyu, Christopher; Gordon, Sydney M.; Hinckley, Alison F.; Singer, Philip

2005-01-01

Individual exposure to trihalomethanes (THMs) in tap water can occur through ingestion, inhalation, or dermal exposure. Studies indicate that activities associated with inhaled or dermal exposure routes result in a greater increase in blood THM concentration than does ingestion. We measured blood and exhaled air concentrations of THM as biomarkers of exposure to participants conducting 14 common household water use activities, including ingestion of hot and cold tap water beverages, showering, clothes washing, hand washing, bathing, dish washing, and indirect shower exposure. We conducted our study at a single residence in each of two water utility service areas, one with relatively high and the other low total THM in the residence tap water. To maintain a consistent exposure environment for seven participants, we controlled water use activities, exposure time, air exchange, water flow and temperature, and nonstudy THM sources to the indoor air. We collected reference samples for water supply and air (pre–water use activity), as well as tap water and ambient air samples. We collected blood samples before and after each activity and exhaled breath samples at baseline and postactivity. All hot water use activities yielded a 2-fold increase in blood or breath THM concentrations for at least one individual. The greatest observed increase in blood and exhaled breath THM concentration in any participant was due to showering (direct and indirect), bathing, and hand dishwashing. Average increase in blood THM concentration ranged from 57 to 358 pg/mL due to these activities. More research is needed to determine whether acute and frequent exposures to THM at these concentrations have public health implications. Further research is also needed in designing epidemiologic studies that minimize data collection burden yet maximize accuracy in classification of dermal and inhalation THM exposure during hot water use activities. PMID:16002374

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.

n-Aldehydes (C6-C10) in snow samples collected at the high alpine research station Jungfraujoch during CLACE 5

NASA Astrophysics Data System (ADS)

Sieg, K.; Starokozhev, E.; Fries, E.; Sala, S.; Püttmann, W.

2009-03-01

Samples of freshly fallen snow were collected at the high alpine research station Jungfraujoch, Switzerland, during the Cloud and Aerosol Characterization Experiments (CLACE) 5 in February and March 2006. Sampling was carried out on the Sphinx platform. Headspace-solid-phase-dynamic extraction (HS-SPDE) combined with gas chromatography/mass spectrometry (GC/MS) was used to quantify C6-C10 n-aldehydes in the snow samples. The most abundant n-aldehyde was n-hexanal (median concentration 1.324 μg L-1) followed by n-nonanal, n-decanal, n-octanal and n-heptanal (median concentrations 1.239, 0.863, 0.460, and 0.304 μg L-1, respectively). A wide range of concentrations was found among individual snow samples, even for samples taken at the same time. Higher median concentrations of all n-aldehydes were observed when air masses reached Jungfraujoch from the north-northwest in comparison to air masses arriving from the southeast-southwest. Results suggest that the n-aldehydes detected most likely are of direct and indirect biogenic origin, and that they entered the snow through the particle phase.

Developing a Vacuum Electrospray Source To Implement Efficient Atmospheric Sampling for Miniature Ion Trap Mass Spectrometer.

PubMed

Yu, Quan; Zhang, Qian; Lu, Xinqiong; Qian, Xiang; Ni, Kai; Wang, Xiaohao

2017-12-05

The performance of a miniature mass spectrometer in atmospheric analysis is closely related to the design of its sampling system. In this study, a simplified vacuum electrospray ionization (VESI) source was developed based on a combination of several techniques, including the discontinuous atmospheric pressure interface, direct capillary sampling, and pneumatic-assisted electrospray. Pulsed air was used as a vital factor to facilitate the operation of electrospray ionization in the vacuum chamber. This VESI device can be used as an efficient atmospheric sampling interface when coupled with a miniature rectilinear ion trap (RIT) mass spectrometer. The developed VESI-RIT instrument enables regular ESI analysis of liquid, and its qualitative and quantitative capabilities have been characterized by using various solution samples. A limit of detection of 8 ppb could be attained for arginine in a methanol solution. In addition, extractive electrospray ionization of organic compounds can be implemented by using the same VESI device, as long as the gas analytes are injected with the pulsed auxiliary air. This methodology can extend the use of the proposed VESI technique to rapid and online analysis of gaseous and volatile samples.

In situ Carbon 13 and Oxygen 18 Ratios of Atmospheric CO2 from Cape Grim\\, Tasmania\\, Australia,1982-1993 (DB1014)

DOE Data Explorer

Francey, R. J. [CSIRO Division of Atmospheric Research, Mordialloc, Victoria, Australia; Allison, C. E. [CSIRO Division of Atmospheric Research, Mordialloc, Victoria, Australia

1998-01-01

Since 1982, a continuous program of sampling atmospheric CO2 to determine stable isotope ratios has been maintained at the Australian Baseline Air Pollution Station, Cape Grim, Tasmania (40°, 40'56"S, 144°, 41'18"E). The process of in situ extraction of CO2 from air, the preponderance of samples collected in conditions of strong wind from the marine boundary layer of the Southern Ocean, and the determination of all isotope ratios relative to a common high purity CO2 reference gas with isotopic δ13C close to atmospheric values, are a unique combination of factors with respect to obtaining a globally representative signal from a surface site. Air samples are collected during baseline condition episodes at a frequency of around one sample per week. Baseline conditions are characterized by wind direction in the sector 190°-280°, condensation nucleus concentration below 600 per cm-3, and steady continuous CO2 concentrations (variation ± 0.2 ppmv per hour). A vacuum pump draws air from either the 10 m or 70 m intakes and sampling alternates between the two intakes. The air from the intake is dried with a trap immersed in an alcohol bath at about -80°C. Mass spectrometer analyses for δ13C and δ18O are carried out by CSIRO's Division of Atmospheric Research in Aspendale, usually one to three weeks following collection. This record is possibly the most accurate representation of global atmospheric 13C behavior over the last decade and may be used to partition the uptake of fossil-fuel carbon emissions between ocean and terrestrial plant reservoirs. Using these data, Francey et al. (1995) observed a gradual decrease in δ13C from 1982 to 1993, but with a pronounced flattening from 1988 to 1990; a trend that appears to involve the terrestrial carbon cycle.

Quantification of Hydroxyl Radical reactivity in the urban environment using the Comparative Reactivity Method (CRM)

NASA Astrophysics Data System (ADS)

Panchal, Rikesh; Monks, Paul

2015-04-01

Hydroxyl (OH) radicals play an important role in 'cleansing' the atmosphere of many pollutants such as, NOx, CH4 and various VOCs, through oxidation. To measure the reactivity of OH, both the sinks and sources of OH need to be quantified, and currently the overall sinks of OH seem not to be fully constrained. In order to measure the total rate loss of OH in an ambient air sample, all OH reactive species must be considered and their concentrations and reaction rate coefficients with OH known. Using the method pioneered by Sinha and Williams at the Max Plank Institute Mainz, the Comparative Reactivity Method (CRM) which directly quantifies total OH reactivity in ambient air without the need to consider the concentrations of individual species within the sample that can react with OH, has been developed and applied in a urban setting. The CRM measures the concentration of a reactive species that is present only in low concentrations in ambient air, in this case pyrrole, flowing through a reaction vessel and detected using Proton Transfer Reaction - Mass Spectrometry (PTR-MS). The poster will show a newly developed and tested PTR-TOF-MS system for CRM. The correction regime will be detailed to account for the influence of the varying humidity between ambient air and clean air on the pyrrole signal. Further, examination of the sensitivity dependence of the PTR-MS as a function of relative humidity and H3O+(H2O) (m/z=37) cluster ion allows the correction for the humidity variation, between the clean humid air entering the reaction vessel and ambient air will be shown. NO, present within ambient air, is also a potential interference and can cause recycling of OH, resulting in an overestimation of OH reactivity. Tests have been conducted on the effects of varying NO concentrations on OH reactivity and a correction factor determined for application to data when sampling ambient air. Finally, field tests in the urban environment at the University of Leicester will be shown coupled to an examination of trends in OH reactivity and other air quality markers such NOx and black carbon.

Urinary polycyclic aromatic hydrocarbons as a biomarker of exposure to PAHs in air: a pilot study among pregnant women.

PubMed

Nethery, Elizabeth; Wheeler, Amanda J; Fisher, Mandy; Sjödin, Andreas; Li, Zheng; Romanoff, Lovisa C; Foster, Warren; Arbuckle, Tye E

2012-01-01

Recent studies have linked increased polycyclic aromatic hydrocarbons (PAHs) in air and adverse fetal health outcomes. Urinary PAH metabolites are of interest for exposure assessment if they can predict PAHs in air. We investigated exposure to PAHs by collecting air and urine samples among pregnant women pre-selected as living in "high" (downtown and close to steel mills, n=9) and "low" (suburban, n=10) exposure areas. We analyzed first-morning urine voids from all 3 trimesters of pregnancy for urinary PAH metabolites and compared these to personal air PAH/PM(2.5)/NO(2)/NO(X) samples collected in the 3rd trimester. We also evaluated activities and home characteristics, geographic indicators and outdoor central site PM(2.5)/NO(2)/NO(X) (all trimesters). Personal air exposures to the lighter molecular weight (MW) PAHs were linked to indoor sources (candles and incense), whereas the heavier PAHs were related to outdoor sources. Geometric means of all personal air measurements were higher in the "high" exposure group. We suggest that centrally monitored heavier MW PAHs could be used to predict personal exposures for heavier PAHs only. Urine metabolites were only directly correlated with their parent air PAHs for phenanthrene (Pearson's r=0.31-0.45) and fluorene (r=0.37-0.58). Predictive models suggest that specific metabolites (3-hydroyxyfluorene and 3-hydroxyphenanthrene) may be related to their parent air PAH exposures. The metabolite 2-hydroxynaphthalene was linked to smoking and the metabolite 1-hydroxypyrene was linked to dietary exposures. For researchers interested in predicting exposure to airborne lighter MW PAHs using urinary PAH metabolites, we propose that hydroxyfluorene and hydroxyphenanthrene metabolites be considered.

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.

Protocol Improvements for Low Concentration DNA-Based Bioaerosol Sampling and Analysis

PubMed Central

Ng, Chun Kiat; Miller, Dana; Cao, Bin

2015-01-01

Introduction As bioaerosol research attracts increasing attention, there is a need for additional efforts that focus on method development to deal with different environmental samples. Bioaerosol environmental samples typically have very low biomass concentrations in the air, which often leaves researchers with limited options in choosing the downstream analysis steps, especially when culture-independent methods are intended. Objectives This study investigates the impacts of three important factors that can influence the performance of culture-independent DNA-based analysis in dealing with bioaerosol environmental samples engaged in this study. The factors are: 1) enhanced high temperature sonication during DNA extraction; 2) effect of sampling duration on DNA recoverability; and 3) an alternative method for concentrating composite samples. In this study, DNA extracted from samples was analysed using the Qubit fluorometer (for direct total DNA measurement) and quantitative polymerase chain reaction (qPCR). Results and Findings The findings suggest that additional lysis from high temperature sonication is crucial: DNA yields from both high and low biomass samples increased up to 600% when the protocol included 30-min sonication at 65°C. Long air sampling duration on a filter media was shown to have a negative impact on DNA recoverability with up to 98% of DNA lost over a 20-h sampling period. Pooling DNA from separate samples during extraction was proven to be feasible with margins of error below 30%. PMID:26619279

Changes in airborne fungi from the outdoors to indoor air; large HVAC systems in nonproblem buildings in two different climates.

PubMed

Kemp, P C; Neumeister-Kemp, H G; Esposito, B; Lysek, G; Murray, F

2003-01-01

Little is known about the changes in occurrence and distribution of airborne fungi as they are transported in the airstream from the outdoor air through the heating, ventilation, and air conditioning (HVAC) system to the indoor air. To better understand this, airborne fungi were analyzed in the HVAC systems of two large office buildings in different climate zones. Fungal samples were taken in each of the walk-in chambers of the HVAC systems using a six-stage Andersen Sampler with malt extract agar. Results showed that fungal species changed with different locations in the HVAC systems. The outdoor air intake produced the greatest filtration effect for both the counts and species of outdoor air fungi. The colony forming unit (CFU) counts and species diversity was further reduced in the air directly after the filters. The cooling coils also had a substantial filtration effect. However, in room air the CFU counts were double and the mixture of fungal species was different from the air leaving the HVAC system at the supply air outlet in most locations. Diffusion of outdoor air fungi to the indoors did not explain the changes in the mixture of airborne fungi from the outdoor air to the indoor air, and some of the fungi present in the indoor air did not appear to be transported indoors by the HVAC systems.

Oxidation of mercury by bromine in the subtropical Pacific free troposphere

NASA Astrophysics Data System (ADS)

Gratz, L. E.; Ambrose, J. L.; Jaffe, D. A.; Shah, V.; Jaeglé, L.; Stutz, J.; Festa, J.; Spolaor, M.; Tsai, C.; Selin, N. E.; Song, S.; Zhou, X.; Weinheimer, A. J.; Knapp, D. J.; Montzka, D. D.; Flocke, F. M.; Campos, T. L.; Apel, E.; Hornbrook, R.; Blake, N. J.; Hall, S.; Tyndall, G. S.; Reeves, M.; Stechman, D.; Stell, M.

2015-12-01

Mercury is a global toxin that can be introduced to ecosystems through atmospheric deposition. Mercury oxidation is thought to occur in the free troposphere by bromine radicals, but direct observational evidence for this process is currently unavailable. During the 2013 Nitrogen, Oxidants, Mercury and Aerosol Distributions, Sources and Sinks campaign, we measured enhanced oxidized mercury and bromine monoxide in a free tropospheric air mass over Texas. We use trace gas measurements, air mass back trajectories, and a chemical box model to confirm the origin and chemical history of the sampled air mass. We find the presence of elevated oxidized mercury to be consistent with oxidation of elemental mercury by bromine atoms in this subsiding upper tropospheric air mass within the subtropical Pacific High, where dry atmospheric conditions are conducive to oxidized mercury accumulation. Our results support the role of bromine as the dominant oxidant of mercury in the upper troposphere.

ATP as a biomarker of viable microorganisms in clean-room facilities

NASA Technical Reports Server (NTRS)

Venkateswaran, Kasthuri; Hattori, Noriaki; La Duc, Myron T.; Kern, Roger

2003-01-01

A new firefly luciferase bioluminescence assay method that differentiates free extracellular ATP (dead cells, etc.) from intracellular ATP (viable microbes) was used to determine the viable microbial cleanliness of various clean-room facilities. For comparison, samples were taken from both clean-rooms, where the air was filtered to remove particles >0.5 microm, and ordinary rooms with unfiltered air. The intracellular ATP was determined after enzymatically degrading the sample's free ATP. Also for comparison, cultivable microbial populations were counted on nutrient-rich trypticase soy agar (TSA) plates. Both the cultivable and ATP-based determinations indicate that the microbial burden was lower in clean-room facilities than in ordinary rooms. However, there was no direct correlation between the two sets of measurements because the two assays measured very different populations. A large fraction of the samples yielded no colony formers on TSA, but were positive for intracellular ATP. Subsequently, genomic DNA was isolated directly from selected samples and 16S rDNA fragments were cloned and sequenced, identifying nearest neighbors, many of which are known to be noncultivable in the media employed. It was concluded that viable microbial contamination can be reliably monitored by measurement of intracellular ATP, and that this method may be considered superior to cultivable colony counts due to its speed and its ability to report the presence of viable but noncultivable organisms. When the detection of nonviable microbes is of interest, the ATP assay can be supplemented with DNA analysis.

ATP as a biomarker of viable microorganisms in clean-room facilities.

PubMed

Venkateswaran, Kasthuri; Hattori, Noriaki; La Duc, Myron T; Kern, Roger

2003-03-01

A new firefly luciferase bioluminescence assay method that differentiates free extracellular ATP (dead cells, etc.) from intracellular ATP (viable microbes) was used to determine the viable microbial cleanliness of various clean-room facilities. For comparison, samples were taken from both clean-rooms, where the air was filtered to remove particles >0.5 microm, and ordinary rooms with unfiltered air. The intracellular ATP was determined after enzymatically degrading the sample's free ATP. Also for comparison, cultivable microbial populations were counted on nutrient-rich trypticase soy agar (TSA) plates. Both the cultivable and ATP-based determinations indicate that the microbial burden was lower in clean-room facilities than in ordinary rooms. However, there was no direct correlation between the two sets of measurements because the two assays measured very different populations. A large fraction of the samples yielded no colony formers on TSA, but were positive for intracellular ATP. Subsequently, genomic DNA was isolated directly from selected samples and 16S rDNA fragments were cloned and sequenced, identifying nearest neighbors, many of which are known to be noncultivable in the media employed. It was concluded that viable microbial contamination can be reliably monitored by measurement of intracellular ATP, and that this method may be considered superior to cultivable colony counts due to its speed and its ability to report the presence of viable but noncultivable organisms. When the detection of nonviable microbes is of interest, the ATP assay can be supplemented with DNA analysis.

Air conditioning system and component therefore distributing air flow from opposite directions

NASA Technical Reports Server (NTRS)

Obler, H. D.; Bauer, H. B. (Inventor)

1974-01-01

The air conditioning system comprises a plurality of separate air conditioning units coupled to a common supply duct such that air may be introduced into the supply duct in two opposite flow directions. A plurality of outlets such as registers or auxiliary or branch ducts communicate with the supply duct and valve means are disposed in the supply duct at at least some of the outlets for automatically channelling a controllable amount of air from the supply duct to the associated outlet regardless of the direction of air flow within the supply duct. The valve means comprises an automatic air volume control apparatus for distribution within the air supply duct into which air may be introduced from two opposite directions. The apparatus incorporates a freely swinging movable vane in the supply duct to automatically channel into the associated outlet only the deflected air flow which has the higher relative pressure.

Radon Concentrations in Drinking Water in Beijing City, China and Contribution to Radiation Dose

PubMed Central

Wu, Yun-Yun; Ma, Yong-Zhong; Cui, Hong-Xing; Liu, Jian-Xiang; Sun, Ya-Ru; Shang, Bing; Su, Xu

2014-01-01

222Rn concentrations in drinking water samples from Beijing City, China, were determined based on a simple method for the continuous monitoring of radon using a radon-in-air monitor coupled to an air-water exchanger. A total of 89 water samples were sampled and analyzed for their 222Rn content. The observed radon levels ranged from detection limit up to 49 Bq/L. The calculated arithmetic and geometric means of radon concentrations in all measured samples were equal to 5.87 and 4.63 Bq/L, respectively. The average annual effective dose from ingestion of radon in drinking water was 2.78 μSv, and that of inhalation of water-borne radon was 28.5 μSv. It is concluded that it is not the ingestion of waterborne radon, but inhalation of the radon escaping from water that is a substantial part of the radiological hazard. Radon in water is a big concern for public health, especially for consumers who directly use well water with very high radon concentration. PMID:25350007

Non-contact evaluation of milk-based products using air-coupled ultrasound

NASA Astrophysics Data System (ADS)

Meyer, S.; Hindle, S. A.; Sandoz, J.-P.; Gan, T. H.; Hutchins, D. A.

2006-07-01

An air-coupled ultrasonic technique has been developed and used to detect physicochemical changes of liquid beverages within a glass container. This made use of two wide-bandwidth capacitive transducers, combined with pulse-compression techniques. The use of a glass container to house samples enabled visual inspection, helping to verify the results of some of the ultrasonic measurements. The non-contact pulse-compression system was used to evaluate agglomeration processes in milk-based products. It is shown that the amplitude of the signal varied with time after the samples had been treated with lactic acid, thus promoting sample destabilization. Non-contact imaging was also performed to follow destabilization of samples by scanning in various directions across the container. The obtained ultrasonic images were also compared to those from a digital camera. Coagulation with glucono-delta-lactone of skim milk poured into this container could be monitored within a precision of a pH of 0.15. This rapid, non-contact and non-destructive technique has shown itself to be a feasible method for investigating the quality of milk-based beverages, and possibly other food products.

Legionella in Puerto Rico cooling towers

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

Negron-Alviro, A.; Perez-Suarez, I.; Hazen, T.C.

1988-12-31

Water samples from air conditioning cooling towers receiving different treatment protocols on five large municipal buildings in San Juan, Puerto Rico were assayed for various species and serogroups of Legionella spp. using direct immunofluorescence. Several water quality parameters were also measured with each sample. Guinea pigs were inoculated with water samples to confirm pathogenicity and recover viable organisms. Legionella pneumophila (1-6), L. bozemanii, L. micdadei, L. dumoffii, and L. gormanii were observed in at least one of the cooling towers. L. pneumophila was the most abundant species, reaching 10{sup 5} cells/ml, within the range that is considered potentially pathogenic tomore » humans. A significantly higher density of L. pneumophila was observed in the cooling tower water that was not being treated with biocides. Percent respiration (INT) and total cell activity (AODC), were inversely correlated with bacterial density. This study demonstrates that Legionella spp. are present in tropical air-conditioning cooling systems, and without continuous biocide treatment may reach densities that present a health risk.« less

Air plasma effect on dental disinfection

NASA Astrophysics Data System (ADS)

Duarte, S.; Kuo, S. P.; Murata, R. M.; Chen, C. Y.; Saxena, D.; Huang, K. J.; Popovic, S.

2011-07-01

A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formation was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.

Air plasma effect on dental disinfection

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

Duarte, S.; Murata, R. M.; Saxena, D.

2011-07-15

A nonthermal low temperature air plasma jet is characterized and applied to study the plasma effects on oral pathogens and biofilms. Experiments were performed on samples of six defined microorganisms' cultures, including those of gram-positive bacteria and fungi, and on a cultivating biofilm sample of Streptococcus mutans UA159. The results show that the plasma jet creates a zone of microbial growth inhibition in each treated sample; the zone increases with the plasma treatment time and expands beyond the entire region directly exposed to the plasma jet. With 30s plasma treatment twice daily during 5 days of biofilm cultivation, its formationmore » was inhibited. The viability of S. mutans cells in the treated biofilms dropped to below the measurable level and the killed bacterial cells concentrated to local regions as manifested by the fluorescence microscopy via the environmental scanning electron microscope. The emission spectroscopy of the jet indicates that its plasma effluent carries an abundance of reactive atomic oxygen, providing catalyst for the observed plasma effect.« less

Fast detection of air contaminants using immunobiological methods

NASA Astrophysics Data System (ADS)

Schmitt, Katrin; Bolwien, Carsten; Sulz, Gerd; Koch, Wolfgang; Dunkhorst, Wilhelm; Lödding, Hubert; Schwarz, Katharina; Holländer, Andreas; Klockenbring, Torsten; Barth, Stefan; Seidel, Björn; Hofbauer, Wolfgang; Rennebarth, Torsten; Renzl, Anna

2009-05-01

The fast and direct identification of possibly pathogenic microorganisms in air is gaining increasing interest due to their threat for public health, e.g. in clinical environments or in clean rooms of food or pharmaceutical industries. We present a new detection method allowing the direct recognition of relevant germs or bacteria via fluorescence-labeled antibodies within less than one hour. In detail, an air-sampling unit passes particles in the relevant size range to a substrate which contains antibodies with fluorescence labels for the detection of a specific microorganism. After the removal of the excess antibodies the optical detection unit comprising reflected-light and epifluorescence microscopy can identify the microorganisms by fast image processing on a single-particle level. First measurements with the system to identify various test particles as well as interfering influences have been performed, in particular with respect to autofluorescence of dust particles. Specific antibodies for the detection of Aspergillus fumigatus spores have been established. The biological test system consists of protein A-coated polymer particles which are detected by a fluorescence-labeled IgG. Furthermore the influence of interfering particles such as dust or debris is discussed.

78 FR 9785 - Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-02-12

... Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances AGENCY: Federal Aviation Administration... airworthiness directive (AD) for certain Lindstrand Hot Air Balloons Ltd female ACME threaded hose connectors...., Washington, DC 20590. For service information identified in this AD, contact Lindstrand Hot Air Balloons Ltd...

77 FR 64763 - Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

... Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances AGENCY: Federal Aviation Administration... propose to adopt a new airworthiness directive (AD) for certain Lindstrand Hot Air Balloons Ltd female... identified in this proposed AD, contact Lindstrand Hot Air Balloons Ltd., Maesbury Road, Oswestry, Shropshire...

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.

Microbiological contamination of compressed air used in dentistry: an investigation.

PubMed

Conte, M; Lynch, R M; Robson, M G

2001-11-01

The purpose of this preliminary investigation was twofold: 1) to examine the possibility of cross-contamination between a dental-evacuation system and the compressed air used in dental operatories and 2) to capture and identify the most common microflora in the compressed-air supply. The investigation used swab, water, and air sampling that was designed to track microorganisms from the evacuation system, through the air of the mechanical room, into the compressed-air system, and back to the patient. Samples taken in the vacuum system, the air space in the mechanical room, and the compressed-air storage tank had significantly higher total concentrations of bacteria than the outside air sampled. Samples of the compressed air returning to the operatory were found to match the outside air sample in total bacteria. It was concluded that the air dryer may have played a significant role in the elimination of microorganisms from the dental compressed-air supply.

Absolute dosimetry on a dynamically scanned sample for synchrotron radiotherapy using graphite calorimetry and ionization chambers

NASA Astrophysics Data System (ADS)

Lye, J. E.; Harty, P. D.; Butler, D. J.; Crosbie, J. C.; Livingstone, J.; Poole, C. M.; Ramanathan, G.; Wright, T.; Stevenson, A. W.

2016-06-01

The absolute dose delivered to a dynamically scanned sample in the Imaging and Medical Beamline (IMBL) on the Australian Synchrotron was measured with a graphite calorimeter anticipated to be established as a primary standard for synchrotron dosimetry. The calorimetry was compared to measurements using a free-air chamber (FAC), a PTW 31 014 Pinpoint ionization chamber, and a PTW 34 001 Roos ionization chamber. The IMBL beam height is limited to approximately 2 mm. To produce clinically useful beams of a few centimetres the beam must be scanned in the vertical direction. In practice it is the patient/detector that is scanned and the scanning velocity defines the dose that is delivered. The calorimeter, FAC, and Roos chamber measure the dose area product which is then converted to central axis dose with the scanned beam area derived from Monte Carlo (MC) simulations and film measurements. The Pinpoint chamber measures the central axis dose directly and does not require beam area measurements. The calorimeter and FAC measure dose from first principles. The calorimetry requires conversion of the measured absorbed dose to graphite to absorbed dose to water using MC calculations with the EGSnrc code. Air kerma measurements from the free air chamber were converted to absorbed dose to water using the AAPM TG-61 protocol. The two ionization chambers are secondary standards requiring calibration with kilovoltage x-ray tubes. The Roos and Pinpoint chambers were calibrated against the Australian primary standard for air kerma at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA). Agreement of order 2% or better was obtained between the calorimetry and ionization chambers. The FAC measured a dose 3-5% higher than the calorimetry, within the stated uncertainties.

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

Air breathing direct methanol fuel cell

DOEpatents

Ren, Xiaoming; Gottesfeld, Shimshon

2002-01-01

An air breathing direct methanol fuel cell is provided with a membrane electrode assembly, a conductive anode assembly that is permeable to air and directly open to atmospheric air, and a conductive cathode assembly that is permeable to methanol and directly contacting a liquid methanol source. Water loss from the cell is minimized by making the conductive cathode assembly hydrophobic and the conductive anode assembly hydrophilic.

Atmospheric transport of pesticides in the Sacramento, California, metropolitan area, 1996-1997

USGS Publications Warehouse

Majewski, Michael S.; Baston, David S.

2002-01-01

Weekly composite, bulk air was sampled with respect to wind speed and direction from January 1996 through December 1997 in one urban and two agricultural locations in Sacramento County, California. The sampling sites were located along a north-south transect, the dominant directions of the prevailing winds. The samples were analyzed for a variety of current-use pesticides, including dormant orchard spray insecticides and rice herbicides. A variety of pesticides were detected throughout the year, predominantly chlorpyrifos, diazinon, and trifluralin. The data obtained during the winter and spring suggest that some pesticides used in agricultural areas become airborne and may be transported into the urban area. Confirmation of this drift is difficult, however, because these three predominant pesticides, as well as other detected pesticides, also are heavily used in the urban environment. The spring data clearly show that molinate and thiobencarb, two herbicides used only in rice production, do drift into the urban environment.

Snowpack Chemistry of Reactive Gases at Station Concordia, Antarctica

NASA Astrophysics Data System (ADS)

Helmig, Detlev; Mass, Alex; Hueber, Jacques; Fain, Xavier; Dommergue, Aurelien; Barbero, Albane; Savarino, Joel

2013-04-01

During December 2012 a new experiment for the study of snow photochemical processes and surface gas exchange was installed at Dome Concordia, Antarctica. The experiment consists of two sampling manifolds ('snow tower') which facilitate the withdrawal of interstitial firn air from four depths in the snowpack and from above the surface. One of these snow towers can be shaded for investigation of the dependency of snow chemistry on solar radiation. A nearby 12 m meteorological tower facilitates above surface turbulence and trace gas gradient measurements. Temperature profiles and UV and IR light penetration are monitored in the snowpack. Air samples are directed through sampling lines to a nearby underground laboratory that houses the experiment control system and gas monitors. The system is fully automated, sampling gases from the array of inlet ports sequentially, and is intended to be operated continuously for a full annual cycle. The computerized control system can be accessed remotely for data retrieval and quality control and for configuring experimental details. Continuous gas measurements include ozone, nitrogen oxides, methane, carbon monoxide, and gaseous elemental mercury. Whole air samples were sampled on four occasions for volatile organic compound analysis. The objective of this research is the study of the year-round snowpack gas chemistry and its dependency on snowpack and above surface physical and environmental conditions. A particular emphasis will be the investigation of the effects of increased UV radiation during the occurrence of the stratospheric ozone hole. We will present the conceptual design of the experiment and data examples from the first three months of the experiment.

Diagnosing AIRS Sampling with CloudSat Cloud Classes

NASA Technical Reports Server (NTRS)

Fetzer, Eric; Yue, Qing; Guillaume, Alexandre; Kahn, Brian

2011-01-01

AIRS yield and sampling vary with cloud state. Careful utilization of collocated multiple satellite sensors is necessary. Profile differences between AIRS and ECMWF model analyses indicate that AIRS has high sampling and excellent accuracy for certain meteorological conditions. Cloud-dependent sampling biases may have large impact on AIRS L2 and L3 data in climate research. MBL clouds / lower tropospheric stability relationship is one example. AIRS and CloudSat reveal a reasonable climatology in the MBL cloud regime despite limited sampling in stratocumulus. Thermodynamic parameters such as EIS derived from AIRS data map these cloud conditions successfully. We are working on characterizing AIRS scenes with mixed cloud types.

Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study.

PubMed

Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D'Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

2017-06-22

Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis ® μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis ® μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis ® μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis ® μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations.

Evaluation of Legionella Air Contamination in Healthcare Facilities by Different Sampling Methods: An Italian Multicenter Study

PubMed Central

Montagna, Maria Teresa; De Giglio, Osvalda; Cristina, Maria Luisa; Napoli, Christian; Pacifico, Claudia; Agodi, Antonella; Baldovin, Tatjana; Casini, Beatrice; Coniglio, Maria Anna; D’Errico, Marcello Mario; Delia, Santi Antonino; Deriu, Maria Grazia; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Moro, Matteo; Mura, Ida; Pennino, Francesca; Privitera, Gaetano; Romano Spica, Vincenzo; Sembeni, Silvia; Spagnolo, Anna Maria; Tardivo, Stefano; Torre, Ida; Valeriani, Federica; Albertini, Roberto; Pasquarella, Cesira

2017-01-01

Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis®μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis®μ were also analyzed by real-time PCR. Legionella presence in the air and water was then compared by sequence-based typing (SBT) methods. Air contamination was found in four HF (36.4%) by at least one of the culturable methods. The culturable investigation by Coriolis®μ did not yield Legionella in any enrolled HF. However, molecular investigation using Coriolis®μ resulted in eight HF testing positive for Legionella in the air. Comparison of Legionella air and water contamination indicated that Legionella water concentration could be predictive of its presence in the air. Furthermore, a molecular study of 12 L. pneumophila strains confirmed a match between the Legionella strains from air and water samples by SBT for three out of four HF that tested positive for Legionella by at least one of the culturable methods. Overall, our study shows that Legionella air detection cannot replace water sampling because the absence of microorganisms from the air does not necessarily represent their absence from water; nevertheless, air sampling may provide useful information for risk assessment. The liquid impingement technique appears to have the greatest capacity for collecting airborne Legionella if combined with molecular investigations. PMID:28640202

A prospective survey of air and surface fungal contamination in a medical mycology laboratory at a tertiary care university hospital.

PubMed

Sautour, Marc; Dalle, Frédéric; Olivieri, Claire; L'ollivier, Coralie; Enderlin, Emilie; Salome, Elsa; Chovelon, Isabelle; Vagner, Odile; Sixt, Nathalie; Fricker-Pap, Véronique; Aho, Serge; Fontaneau, Olivier; Cachia, Claire; Bonnin, Alain

2009-04-01

Invasive filamentous fungi infections resulting from inhalation of mold conidia pose a major threat in immunocompromised patients. The diagnosis is based on direct smears, cultural symptoms, and culturing fungi. Airborne conidia present in the laboratory environment may cause contamination of cultures, resulting in false-positive diagnosis. Baseline values of fungal contamination in a clinical mycology laboratory have not been determined to date. A 1-year prospective survey of air and surface contamination was conducted in a clinical mycology laboratory during a period when large construction projects were being conducted in the hospital. Air was sampled with a portable air system impactor, and surfaces were sampled with contact Sabouraud agar plates. The collected data allowed the elaboration of Shewhart graphic charts. Mean fungal loads ranged from 2.27 to 4.36 colony forming units (cfu)/m(3) in air and from 0.61 to 1.69 cfu/plate on surfaces. Strict control procedures may limit the level of fungal contamination in a clinical mycology laboratory even in the context of large construction projects at the hospital site. Our data and the resulting Shewhart graphic charts provide baseline values to use when monitoring for inappropriate variations of the fungal contamination in a mycology laboratory as part of a quality assurance program. This is critical to the appropriate management of the fungal risk in hematology, cancer and transplantation patients.

Method for Measuring Thermal Conductivity of Small Samples Having Very Low Thermal Conductivity

NASA Technical Reports Server (NTRS)

Miller, Robert A.; Kuczmarski, Maria a.

2009-01-01

This paper describes the development of a hot plate method capable of using air as a standard reference material for the steady-state measurement of the thermal conductivity of very small test samples having thermal conductivity on the order of air. As with other approaches, care is taken to ensure that the heat flow through the test sample is essentially one-dimensional. However, unlike other approaches, no attempt is made to use heated guards to block the flow of heat from the hot plate to the surroundings. It is argued that since large correction factors must be applied to account for guard imperfections when sample dimensions are small, it may be preferable to simply measure and correct for the heat that flows from the heater disc to directions other than into the sample. Experimental measurements taken in a prototype apparatus, combined with extensive computational modeling of the heat transfer in the apparatus, show that sufficiently accurate measurements can be obtained to allow determination of the thermal conductivity of low thermal conductivity materials. Suggestions are made for further improvements in the method based on results from regression analyses of the generated data.

Octafluoropropane Concentration Dynamics on Board the International Space Station

NASA Technical Reports Server (NTRS)

Perry, J. L.

2003-01-01

Since activating the International Space Station s (IS9 Service Module in November 2000, archival air quality samples have shown highly variable concentrations of octafluoropropane in the cabin. This variability has been directly linked to leakage from air conditioning systems on board the Service Module, Zvezda. While octafluoro- propane is not highly toxic, it presents a significant chal- lenge to the trace contaminant control systems. A discussion of octafluoropropane concentration dynamics is presented and the ability of on board trace contami- nant control systems to effectively remove octafluoropro- pane from the cabin atmosphere is assessed. Consideration is given to operational and logistics issues that may arise from octafluoropropane and other halo- carbon challenges to the contamination control systems as well as the potential for effecting cabin air quality.

AN ION CORRELATION PROGRAM FOR DECONVOLUTING COMPOSITE MASS SPECTRA ACQUIRED USING A DIRECT SURFACE IONIZATION SOURCE INTERFACED TO A TIME-OF-FLIGHT MASS SPECTROMETER

EPA Science Inventory

The rapid sampling provided by the DART in ambient air will allow rapid delineation of areas of dispersed chemicals after natural or man-made disasters. Exact masses and RIAs of dimer, precursor, and product ions measured by the oa-TOFMS entered dinto the Ion Correlation Program...

Simple, Efficient, and Rapid Methods to Determine the Potential for Vapor Intrusion into the Home: Temporal Trends, Vapor Intrusion Forecasting, Sampling Strategies, and Contaminant Migration Routes

EPA Science Inventory

Current practice for evaluating the vapor intrusion pathway involves a multiple line of evidence approach based on direct measurements of volatile organic compound (VOC) concentrations in groundwater, external soil gas, subslab soil gas, and/or indoor air. No single line of evide...

Direct real-time detection of vapors from explosive compounds.

PubMed

Ewing, Robert G; Clowers, Brian H; Atkinson, David A

2013-11-19

The real-time detection of vapors from low volatility explosives including PETN, tetryl, RDX, and nitroglycerine along with various compositions containing these substances was demonstrated. This was accomplished with an atmospheric flow tube (AFT) using a nonradioactive ionization source coupled to a mass spectrometer. Direct vapor detection was accomplished in less than 5 s at ambient temperature without sample preconcentration. The several seconds of residence time of analytes in the AFT provided a significant opportunity for reactant ions to interact with analyte vapors to achieve ionization. This extended reaction time, combined with the selective ionization using the nitrate reactant ions (NO3(-) and NO3(-)·HNO3), enabled highly sensitive explosives detection from explosive vapors present in ambient laboratory air. Observed signals from diluted explosive vapors indicated detection limits below 10 ppqv using selected ion monitoring (SIM) of the explosive-nitrate adduct at m/z 349, 378, 284, and 289 for tetryl, PETN, RDX, and NG, respectively. Also provided is a demonstration of the vapor detection from 10 different energetic formulations sampled in ambient laboratory air, including double base propellants, plastic explosives, and commercial blasting explosives using SIM for the NG, PETN, and RDX product ions.

A Novel UAS Rapid Deployment Platform for Targeted Gas Sampling and Meteorological Soundings at Altitudes up to 2,700 masl

NASA Astrophysics Data System (ADS)

Thomas, Rick M.; Greatwood, Colin; Richardson, Tom; Freer, Jim; MacKenzie, Rob; Brownlow, Rebecca; Lowry, David; Fisher, Rebecca E.; France, James; Nisbet, Euan G.

2015-04-01

This research project has developed Unmanned Aerial System (UAS) technologies for intelligent targeting and collection of atmospheric gas samples to investigate the so-called Southern Tropical Methane Anomaly, for which it is necessary to sample air below and above the trade-wind inversion. Air parcels above and below the South Atlantic trade-wind inversion can have markedly different trajectories and, hence, encounter very different methane source regions. The system is intelligent in that high resolution temperature and humidity sensors linked to the ground station characterise the atmospheric profile on the upward flight to ensure the platform targets the appropriate sample elevations on the downward trajectory. This capability has been proven to an altitude of 2,700 metres above sea level (masl; ca. 700 mb) at Ascension Island in the South Atlantic and shown that rapid and repeat deployment and sample collection is achievable. Three novel eight motor multirotor UAS (or octocopter) platforms were developed at Bristol Robotics Laboratory (BRL) using primarily off -the-shelf components with a custom-built main fuselage. Gas sampling and atmospheric sensor systems were designed by the University of Birmingham. Our paper explores the capability of this UAS and provides some initial results from the air sampling campaign conducted in September 2014. Thirty-eight sampling flights were conducted over 12 days and the resulting 47 samples analysed for their CH4 concentration using the high-precision Picarro Cavity Ring Down Spectrometer already installed at Ascension Island. A subset of samples were sent for δ13CCH4 analysis in Egham, UK. The flights were conducted up to an altitude of 2,700m with 2,000m being typical. There were no major incidents although variable zero and high wind situations above the trade wind inversion (typically at 1,800m) both presented unique challenges and required careful flight planning strategies and in flight trajectory changes. As a result algorithms were developed to estimate in-flight wind speed and direction from aircraft attitude data. The results from the meteorological samples compared favourably with modelled data from the local Met Office station and we also show comparisons with wind speed and direction as well as insights gained from the CH4 analysis. Finally, system improvements and further measurements planned for our return to the island in mid-2015 are presented. Acknowledgement This work is supported by the Natural Environment Research Council Grant NE/K005979/1.

Airsheds, Isotopes and Ecosystem Metabolism in Mountainous Terrain

NASA Astrophysics Data System (ADS)

Sulzman, E.; Barnard, H.; Bond, B. J.; Czarnomski, N. M.; Hauck, M.; Kayler, Z.; Mix, A. C.; Pypker, T.; Rugh, W.; Unsworth, M.

2005-12-01

At least 20% of the terrestrial surface of the earth is covered by mountains, which contain many of the world's most productive ecosystems. Interactions between vegetation and the physical environment are often very different in mountains than on flat land. However, few studies have addressed these unique interactions, and many of the tools used to measure and monitor ecosystem metabolism are difficult or impossible to use in complex, mountainous terrain. In a project we call the "Andrews Airshed study" located in western Oregon Cascades, we aim to identify and explore sources of variation in the isotopic composition of ecosystem respiration (δ13CR-eco) and airflow patterns in cold-air drainage, with the eventual aim of "inverting" this understanding so that we can use δ13CR-eco to monitor intra- and inter-annual variations in ecosystem metabolism on a basin scale. We are measuring patterns of airflow, quantifying the CO2 concentration in the flow, and measuring the carbon isotope composition of ecosystem-respired CO2 as well as soil-respired CO2 (δ13CR-soil), which accounts for more than half of δ13CR-eco. We have designed an automated air sampling device that we programmed to sample air at 10 ppm intervals from 30 m above the stream in our 100 ha, deeply-incised watershed. Samples are collected via Valco valves into stainless steel tubing that can be connected directly to an isotope ratio mass spectrometer. We also designed and installed soil gas sampling probes, which are located in five 10 m2 sampling plots from ridge top to valley floor to the opposite ridge top. Weekly samples (May-Sept, 2005) of air from soil and the nocturnal air flow show seasonal variation in δ13CR-eco over a 2 per mil range, with more enriched values corresponding to lower soil moisture. Soil-respired CO2 also reveal seasonality and are isotopically enriched compared with above-ground air. δ13CR-soil values from north- and south-facing slopes of the watershed differ by 1 per mil, with south-facing values consistently enriched relative to those of the north-facing slope. We are concurrently conducting studies to determine the appropriate footprint of respired CO2 in the nocturnal airstream, which will allow us to overlay the data properly.

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.

Photothermal method for in situ microanalysis of the chemical composition of coal samples

DOEpatents

Amer, Nabil M.

1986-01-01

Successive minute regions (13) along a scan path on a coal sample (11) are individually analyzed, at a series of different depths if desired, to determine chemical composition including the locations, sizes and distributions of different maceral inclusions (12). A sequence of infrared light pulses (17) of progressively changing wavelengths is directed into each minute region (13) and a probe light beam (22) is directed along the sample surface (21) adjacent the region (13). Infrared wavelengths at which strong absorption occurs in the region (13) are identified by detecting the resulting deflections (.phi.) of the probe beam (22) caused by thermally induced index of refraction changes in the air or other medium (19) adjacent the region (13). The detected peak absorption wavelengths are correlated with known characteristic peak absorption wavelengths of specific coal constituents to identify the composition of each such minute region (13) of the sample (11). The method enables rapid, convenient and non-destructive analyses of coal specimens to facilitate mining, processing and utilization of coals.

Photothermal method for in situ microanalysis of the chemical composition of coal samples

DOEpatents

Amer, N.M.

1983-10-25

Successive minute regions along a scan path on a coal sample are individually analyzed, at a series of different depths if desired, to determine chemical composition including the locations, sizes and distributions of different maceral inclusions. A sequence of infrared light pulses of progressively changing wavelengths is directed into each minute region and a probe light beam is directed along the sample surface adjacent the region. Infrared wavelengths at which strong absorption occurs in the region are identified by detecting the resulting deflections of the probe beam caused by thermally induced index of refraction changes in the air or other medium adjacent the region. The detected peak absorption wavelengths are correlated with known characteristic peak absorption wavelengths of specific coal constituents to identify the composition of each such minute region of the sample. The method enables rapid, convenient and non-destructive analyses of coal specimens to facilitate mining, processing and utilization of coals. 2 figures.

Direct analysis of organic priority pollutants by IMS

NASA Technical Reports Server (NTRS)

Giam, C. S.; Reed, G. E.; Holliday, T. L.; Chang, L.; Rhodes, B. J.

1995-01-01

Many routine methods for monitoring of trace amounts of atmospheric organic pollutants consist of several steps. Typical steps are: (1) collection of the air sample; (2) trapping of organics from the sample; (3) extraction of the trapped organics; and (4) identification of the organics in the extract by GC (gas chromatography), HPLC (High Performance Liquid Chromatography), or MS (Mass Spectrometry). These methods are often cumbersome and time consuming. A simple and fast method for monitoring atmospheric organics using an IMS (Ion Mobility Spectrometer) is proposed. This method has a short sampling time and does not require extraction of the organics since the sample is placed directly in the IMS. The purpose of this study was to determine the responses in the IMS to organic 'priority pollutants'. Priority pollutants including representative polycyclic aromatic hydrocarbons (PAHs), phthalates, phenols, chlorinated pesticides, and polychlorinated biphenyls (PCB's) were analyzed in both the positive and negative detection mode at ambient atmospheric pressure. Detection mode and amount detected are presented.

Fiber Orientation Effects in Fused Filament Fabrication of Air-Cooled Heat Exchangers

NASA Astrophysics Data System (ADS)

Mulholland, T.; Goris, S.; Boxleitner, J.; Osswald, T. A.; Rudolph, N.

2018-03-01

Fused filament fabrication (FFF) is a type of additive manufacturing based on material extrusion that has long been considered a prototyping technology. However, the right application of material, process, and product can be used for manufacturing of end-use products, such as air-cooled heat exchangers made by adding fillers to the base polymer, enhancing the thermal conductivity. Fiber fillers lead to anisotropic thermal conductivity, which is governed by the process-induced fiber orientation. This article presents an experimental study on the microstructure-property relationship for carbon fiber-filled polyamide used in FFF. The fiber orientation is measured by micro-computed tomography, and the thermal conductivity of manufactured samples is measured. Although the thermal conductivity is raised by more than three times in the fiber orientation direction at a load of only 12 vol.%, the enhancement is low in the other directions, and this anisotropy, along with certain manufacturing restrictions, influences the final part performance.

The relationships among cloud microphysics, chemistry, and precipitation rate in cold mountain clouds

NASA Astrophysics Data System (ADS)

Borys, Randolph D.; Lowenthal, Douglas H.; Mitchell, David L.

A study was conducted to examine the relationships among air pollutant loadings, cloud microphysics, and snowfall rates in cold mountain clouds. It was hypothesized that variations in pollutant loadings would be reflected in shifts in the cloud droplet size distribution. A field program was conducted at Storm Peak Laboratory (SPL) at an elevation of 3210 m MSL in northwestern Colorado. Cold precipitating clouds were sampled during January, 1995. Cloud water was collected and analyzed for major ion and trace element chemistry. Cloud droplet concentrations and size were measured continuously using a PMS FSSP-100. The results indicate a direct relationship between clear-air equivalent (CAE) sulfate concentrations in cloud water and cloud droplet concentrations, an indirect relationship between droplet number and droplet size, a direct relationship between droplet size and snowfall rate, and an indirect relationship between CAE sulfate concentration and snowfall rate.

14 CFR 380.11 - Payment to direct air carrier(s).

Code of Federal Regulations, 2010 CFR

2010-01-01

... carrier(s). Except for air taxi operators and commuter air carriers (which are governed by 14 CFR 298.38) and Canadian charter air taxi operators (which are governed by 14 CFR 294.32), the direct air carrier...

14 CFR 380.11 - Payment to direct air carrier(s).

Code of Federal Regulations, 2011 CFR

2011-01-01

... carrier(s). Except for air taxi operators and commuter air carriers (which are governed by 14 CFR 298.38) and Canadian charter air taxi operators (which are governed by 14 CFR 294.32), the direct air carrier...

Environmental Perception and Citizen Response: a Denver, Colorado Air Pollution Case Study.

NASA Astrophysics Data System (ADS)

Naomi, Leaura M.

Denver, a high altitude city, suffers from air pollution. Automobile emissions, as well as wood and coal burning contribute to Denver's air pollution. In order to reduce its air pollution, Denver hosted a no-drive campaign, The Better Air Campaign. This study examined how Denver -area citizens perceived their air pollution, responded to their air pollution, and responded to their no-drive campaign. First, I conducted personal interviews of twenty Denver air pollution decision-makers to ascertain their perceptions and definitions of Denver's air pollution problem. Second, I created a theoretical model of environmental perception and behavioral response to air pollution. Third, I conducted a telephone survey of 500 Denver-area residents to examine the usefulness of the model. By segmenting a sample of 500 Denver-area residents via a modified values and lifestyles (VALS) technique included in a telephone survey, the perceptions and behaviors of residents fell into a clear pattern. This values and lifestyles pattern coincided with a conventional innovation-adoption pattern, including innovators, the bandwagon, and laggards. Thus, the research determined the population's perceptions and behavioral responses to their air pollution. The research also pointed a direction for Denver's air pollution decision-makers to follow in order to reduce use of the gasoline-powered automobile. And, for those interested in encouraging public acceptance of ecological sustainability, it suggested application of the VALS technique for reaching the public.

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.

The humidity dependence of ozone deposition onto a variety of building surfaces

NASA Astrophysics Data System (ADS)

Grøntoft, Terje; Henriksen, Jan F.; Seip, Hans M.

Measurements of the dry deposition velocity of O 3 to material samples of calcareous stone, concrete and wood at varying humidity of the air, were performed in a deposition chamber. Equilibrium surface deposition velocities were found for various humidity values by fitting a model to the time-dependent deposition data. A deposition velocity-humidity model was derived giving three separate rate constants for the surface deposition velocities, i.e. on the dry surface, on the first mono-layer of adsorbed water and on additional surface water. The variation in the dry air equilibrium surface deposition velocities among the samples correlated with variations in effective areas, with larger effective areas giving higher measured deposition velocities. A minimum for the equilibrium surface deposition velocity was generally measured at an intermediate humidity close to the humidity found to correspond to one mono-layer of water molecules on the surfaces. At low air humidity the equilibrium surface deposition velocity of O 3 was found to decrease as more adsorbed water prevented direct contact of the O 3 molecules with the surface. This was partly compensated by an increase as more adsorbed water became available for reaction with O 3. At high air humidity the equilibrium surface deposition velocity was found to increase as the mass of water on the surface increased. The deposition velocity on bulk de-ionised water at RH=90% was an order of magnitude lower than on the sample surfaces.

75 FR 56487 - Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-16

...-0909; Directorate Identifier 2010-SW-026-AD] RIN 2120-AA64 Airworthiness Directives; Erickson Air-Crane... rulemaking (NPRM). SUMMARY: This document proposes adopting a new airworthiness directive (AD) for Erickson Air-Crane Incorporated (Erickson Air-Crane) Model S- 64F helicopters. The AD would require, at...

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.

Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter in Venice air.

PubMed

Gregoris, Elena; Barbaro, Elena; Morabito, Elisa; Toscano, Giuseppa; Donateo, Antonio; Cesari, Daniela; Contini, Daniele; Gambaro, Andrea

2016-04-01

Harbours are important hubs for economic growth in both tourism and commercial activities. They are also an environmental burden being a source of atmospheric pollution often localized near cities and industrial complexes. The aim of this study is to quantify the relative contribution of maritime traffic and harbour activities to atmospheric pollutant concentration in the Venice lagoon. The impact of ship traffic was quantified on various pollutants that are not directly included in the current European legislation for shipping emission reduction: (i) gaseous and particulate PAHs; (ii) metals in PM10; and (iii) PM10 and PM2.5. All contributions were correlated with the tonnage of ships during the sampling periods and results were used to evaluate the impact of the European Directive 2005/33/EC on air quality in Venice comparing measurements taken before and after the application of the Directive (year 2010). The outcomes suggest that legislation on ship traffic, which focused on the issue of the emissions of sulphur oxides, could be an efficient method also to reduce the impact of shipping on primary particulate matter concentration; on the other hand, we did not observe a significant reduction in the contribution of ship traffic and harbour activities to particulate PAHs and metals. Graphical abstract Impact of maritime traffic on polycyclic aromatic hydrocarbons, metals and particulate matter and evaluation of the effect of an European Directive on air quality in Venice.

Analysis of volatile organic compounds. [trace amounts of organic volatiles in gas samples

NASA Technical Reports Server (NTRS)

Zlatkis, A. (Inventor)

1977-01-01

An apparatus and method are described for reproducibly analyzing trace amounts of a large number of organic volatiles existing in a gas sample. Direct injection of the trapped volatiles into a cryogenic percolum provides a sharply defined plug. Applications of the method include: (1) analyzing the headspace gas of body fluids and comparing a profile of the organic volatiles with standard profiles for the detection and monitoring of disease; (2) analyzing the headspace gas of foods and beverages and comparing the profile with standard profiles to monitor and control flavor and aroma; and (3) analyses for determining the organic pollutants in air or water samples.

Assessment of ambient air quality in Eskişehir, Turkey.

PubMed

Ozden, O; Döğeroğlu, T; Kara, S

2008-07-01

This paper presents an assessment of air quality of the city Eskişehir, located 230 km southwest to the capital of Turkey. Only five of the major air pollutants, most studied worldwide and available for the region, were considered for the assessment. Available sulphur dioxide (SO(2)), particulate matter (PM), nitrogen dioxide (NO(2)), ozone (O(3)), and non-methane volatile organic carbons (NMVOCs) data from local emission inventory studies provided relative source contributions of the selected pollutants to the region. The contributions of these typical pollution parameters, selected for characterizing such an urban atmosphere, were compared with the data established for other cities in the nation and world countries. Additionally, regional ambient SO(2) and PM concentrations, determined by semi-automatic monitoring at two sites, were gathered from the National Ambient Air Monitoring Network (NAAMN). Regional data for ambient NO(2) (as a precursor of ozone as VOCs) and ozone concentrations, through the application of the passive sampling method, were provided by the still ongoing local air quality monitoring studies conducted at six different sites, as representatives of either the traffic-dense-, or coal/natural gas burning residential-, or industrial/rural-localities of the city. Passively sampled ozone data at a single rural site were also verified with the data from a continuous automatic ozone monitoring system located at that site. Effects of variations in seasonal-activities, newly established railway system, and switching to natural gas usage on the temporal changes of air quality were all considered for the assessment. Based on the comparisons with the national [AQCR (Air Quality Control Regulation). Ministry of Environment (MOE), Ankara. Official Newspaper 19269; 1986.] and a number of international [WHO (World Health Organization). Guidelines for Air Quality. Geneva; 2000. Downloaded in January 2006, website: http://www.who.int/peh/; EU (European Union). Council Directive 1999/30/EC relating to limit values for sulfur dioxide, nitrogen dioxide and lead in ambient air. Of J Eur Communities L 163: 14-30; 29.6.1999; EU (European Union). Council Directive 2002/3/EC relating to ozone in ambient air. Of J Eur Communities. L 67: 14-30; 9.3.2002.; USEPA (U.S. Environmental Protection Agency). National Ambient Air Quality Standards (NAAQS). Downloaded in January 2006, website: http://www.epa.gov/ttn/naaqs/] ambient air standards, among all the pollutants studied, only the annual average SO(2) concentration was found to exceed one specific limit value (EU limit for protection of the ecosystem). A part of the data (VOC/NO(x) ratio), for determining the effects of photochemical interactions, indicated that VOC-limited regime was prevailing throughout the city.

Adaptive Sampling for Urban Air Quality through Participatory Sensing

PubMed Central

Zeng, Yuanyuan; Xiang, Kai

2017-01-01

Air pollution is one of the major problems of the modern world. The popularization and powerful functions of smartphone applications enable people to participate in urban sensing to better know about the air problems surrounding them. Data sampling is one of the most important problems that affect the sensing performance. In this paper, we propose an Adaptive Sampling Scheme for Urban Air Quality (AS-air) through participatory sensing. Firstly, we propose to find the pattern rules of air quality according to the historical data contributed by participants based on Apriori algorithm. Based on it, we predict the on-line air quality and use it to accelerate the learning process to choose and adapt the sampling parameter based on Q-learning. The evaluation results show that AS-air provides an energy-efficient sampling strategy, which is adaptive toward the varied outside air environment with good sampling efficiency. PMID:29099766

Imaging graphite in air by scanning tunneling microscopy - Role of the tip

NASA Technical Reports Server (NTRS)

Colton, R. J.; Baker, S. M.; Driscoll, R. J.; Youngquist, M. G.; Baldeschwieler, J. D.; Kaiser, W. J.

1988-01-01

Atomically resolved images of highly oriented pyrolytic graphite (HOPG) in air at point contact have been obtained. Direct contact between tip and sample or contact through a contamination layer provides a conduction mechanism in addition to the exponential tunneling mechanism responsible for scanning tunneling microscopy (STM) imaging. Current-voltage (I-V) spectra were obtained while scanning in the current imaging mode with the feedback circuit interrupted in order to study the graphite imaging mechanism. Multiple tunneling tips are probably responsible for images without the expected hexagonal or trigonal symmetry. The observations indicate that the use of HOPG for testing and calibration of STM instrumentation may be misleading.

Optical detection of radon decay in air

PubMed Central

Sand, Johan; Ihantola, Sakari; Peräjärvi, Kari; Toivonen, Harri; Toivonen, Juha

2016-01-01

An optical radon detection method is presented. Radon decay is directly measured by observing the secondary radiolumines cence light that alpha particles excite in air, and the selectivity of coincident photon detection is further enhanced with online pulse-shape analysis. The sensitivity of a demonstration device was 6.5 cps/Bq/l and the minimum detectable concentration was 12 Bq/m3 with a 1 h integration time. The presented technique paves the way for optical approaches in rapid radon detec tion, and it can be applied beyond radon to the analysis of any alpha-active sample which can be placed in the measurement chamber. PMID:26867800

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.

[Characteristics of mercury exchange flux between soil and atmosphere under the snow retention and snow melting control].

PubMed

Zhang, Gang; Wang, Ning; Ai, Jian-Chao; Zhang, Lei; Yang, Jing; Liu, Zi-Qi

2013-02-01

Jiapigou gold mine, located in the upper Songhua River, was once the largest mine in China due to gold output, where gold extraction with algamation was widely applied to extract gold resulting in severe mercury pollution to ambient environmental medium. In order to study the characteristics of mercury exchange flux between soil (snow) and atmosphere under the snow retention and snow melting control, sampling sites were selected in equal distances along the slope which is situated in the typical hill-valley terrain unit. Mercury exchange flux between soil (snow) and atmosphere was determined with the method of dynamic flux chamber and in all sampling sites the atmosphere concentration from 0 to 150 cm near to the earth in the vertical direction was measured. Furthermore, the impact factors including synchronous meteorology, the surface characteristics under the snow retention and snow melting control and the mercury concentration in vertical direction were also investigated. The results are as follows: During the period of snow retention and melting the air mercury tends to gather towards valley bottom along the slope and an obvious deposit tendency process was found from air to the earth's surface under the control of thermal inversion due to the underlying surface of cold source (snow surface). However, during the period of snow melting, mercury exchange flux between the soil and atmosphere on the surface of the earth with the snow being melted demonstrates alternative deposit and release processes. As for the earth with snow covered, the deposit level of mercury exchange flux between soil and atmosphere is lower than that during the period of snow retention. The relationship between mercury exchange flux and impact factors shows that in snow retention there is a remarkable negative linear correlation between mercury exchange flux and air mercury concentration as well as between the former and the air temperature. In addition, in snow melting mercury exchange flux is remarkably negatively linearly correlated to air mercury concentration and positively linearly correlated to air temperature. Furthermore, there is a general positive linear correlation between mercury exchange flux and soil temperature on the surface of earth after snow melting.

Airborne fibre and asbestos concentrations in system built schools

NASA Astrophysics Data System (ADS)

Burdett, Garry; Cottrell, Steve; Taylor, Catherine

2009-02-01

This paper summarises the airborne fibre concentration data measured in system built schools that contained asbestos insulation board (AIB) enclosed in the support columns by a protective steel casing. The particular focus of this work was the CLASP (Consortium of Local Authorities Special Programme) system buildings. A variety of air monitoring tests were carried out to assess the potential for fibres to be released into the classroom. A peak release testing protocol was adopted that involved static sampling, while simulating direct impact disturbances to selected columns. This was carried out before remediation, after sealing gaps and holes in and around the casing visible in the room (i.e. below ceiling level) and additionally round the tops of the columns, which extended into the suspended ceiling void. Simulated and actual measurements of worker exposures were also undertaken, while sealing columns, carrying out cleaning and maintenance work in the ceiling voids. Routine analysis of these air samples was carried out by phase contrast microscopy (PCM) with a limited amount of analytical transmission electron microscopy (TEM) analysis to confirm whether the fibres visible by PCM were asbestos or non-asbestos. The PCM fibre concentrations data from the peak release tests showed that while direct releases of fibres to the room air can occur from gaps and holes in and around the column casings, sealing is an effective way of minimising releases to below the limit of quantification (0.01 f/ml) of the PCM method for some 95% of the tests carried out. Sealing with silicone filler and taping any gaps and seams visible on the column casing in the room, also gave concentrations below the limit of quantification (LOQ) of the PCM method for 95% of the tests carried out. The data available did not show any significant difference between the PCM fibre concentrations in the room air for columns that had or had not been sealed in the ceiling void, as well as in the room. Occupant exposures during normal classroom teaching activities in areas that had undergone remediation were also monitored with much greater use of TEM analysis to determine the asbestos fibre concentration. No asbestos fibres were found in the TEM analysis of samples of classroom air from seven schools, after remediation had taken place. Occupant exposures in one school and one office building have been monitored before remediation and only one asbestos fibre was found in each set of samples analysed. The average monitored occupant exposures to asbestos in CLASP buildings was <0.00005 f/ml, an order of magnitude lower than previous measurements in UK buildings.

The CHRONOS mission: capability for sub-hourly synoptic observations of carbon monoxide and methane to quantify emissions and transport of air pollution

NASA Astrophysics Data System (ADS)

Edwards, David P.; Worden, Helen M.; Neil, Doreen; Francis, Gene; Valle, Tim; Arellano, Avelino F., Jr.

2018-02-01

The CHRONOS space mission concept provides time-resolved abundance for emissions and transport studies of the highly variable and highly uncertain air pollutants carbon monoxide and methane, with sub-hourly revisit rate at fine (˜ 4 km) horizontal spatial resolution across a North American domain. CHRONOS can provide complete synoptic air pollution maps (snapshots) of the continental domain with less than 10 min of observations. This rapid mapping enables visualization of air pollution transport simultaneously across the entire continent and enables a sentinel-like capability for monitoring evolving, or unanticipated, air pollution sources in multiple locations at the same time with high temporal resolution. CHRONOS uses a compact imaging gas filter correlation radiometer for these observations, with heritage from more than 17 years of scientific data and algorithm advances by the science teams for the Measurements of Pollution in the Troposphere (MOPITT) instrument on NASA's Terra spacecraft in low Earth orbit. To achieve continental-scale sub-hourly sampling, the CHRONOS mission would be conducted from geostationary orbit, with the instrument hosted on a communications or meteorological platform. CHRONOS observations would contribute to an integrated observing system for atmospheric composition using surface, suborbital and satellite data with atmospheric chemistry models, as defined by the Committee on Earth Observing Satellites. Addressing the U.S. National Academy's 2007 decadal survey direction to characterize diurnal changes in tropospheric composition, CHRONOS observations would find direct societal applications for air quality management and forecasting to protect public health.

Occurrence and impact of polychlorinated dibenzo-p-dioxins/dibenzofurans in the air and soil around a municipal solid waste incinerator.

PubMed

Zhou, Zhiguang; Ren, Yue; Chu, Jiazhi; Li, Nan; Zhen, Sen; Zhao, Hu; Fan, Shuang; Zhang, Hui; Xu, Pengjun; Qi, Li; Liang, Shuting; Zhao, Bin

2016-06-01

To assess the influence of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) on the environment in the vicinity of municipal solid waste incinerators (MSWIs), we determined the levels of PCDD/Fs in air and soil samples collected around a MSWI, which is the largest in China. The International Toxicity Equivalency Quantity (I-TEQ) concentrations of PCDD/Fs in air samples were from 0.0300 to 1.03pgI-TEQ/m(3) (0.445-13.6pg/m(3)), with an average of 0.237pgI-TEQ/m(3), while in soil samples they ranged from 0.520 to 3.40pgI-TEQ/g (2.41-88.7pg/g) with an average of 1.49pgI-TEQ/g. The concentrations of PCDD/Fs in air and soil samples were comparable to other areas, and PeCDFs were the dominant contributors, which was different from stack gas homologue patterns. Multivariate statistical analysis showed that PCDD/Fs emission from the MSWI did not directly affect the profiles of PCDD/Fs in air and soils, so that vehicles and unidentified emission sources should be considered. The daily inhalation levels of PCDD/Fs for children (0.0110 to 0.392pgI-TEQ/(kg·day) and adults (0.00600 to 0.221pgI-TEQ/(kg·day) near the MSWI were lower than the tolerable daily intake of 1.00 to 4.00pg WHO-TEQ/(kg·day), but in winter the values were higher than in summer. These results can be used as basic data for assessing the risk of PCDD/Fs exposure in residents living around this MSWI, and more monitoring programs and studies should be carried out around MSWIs. Copyright © 2016. Published by Elsevier B.V.

14 CFR 380.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

...: Certificated air carrier means a U.S. direct air carrier holding a certificate issued under the statute. Charter flight means a flight operated under the terms of a charter contract between a direct air carrier and its customer. It does not include scheduled air transportation, scheduled foreign air...

14 CFR 380.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

...: Certificated air carrier means a U.S. direct air carrier holding a certificate issued under the statute. Charter flight means a flight operated under the terms of a charter contract between a direct air carrier and its customer. It does not include scheduled air transportation, scheduled foreign air...

14 CFR 380.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

...: Certificated air carrier means a U.S. direct air carrier holding a certificate issued under the statute. Charter flight means a flight operated under the terms of a charter contract between a direct air carrier and its customer. It does not include scheduled air transportation, scheduled foreign air...

Eight Year Climatologies from Observational (AIRS) and Model (MERRA) Data

NASA Technical Reports Server (NTRS)

Hearty, Thomas; Savtchenko, Andrey; Won, Young-In; Theobalk, Mike; Vollmer, Bruce; Manning, Evan; Smith, Peter; Ostrenga, Dana; Leptoukh, Greg

2010-01-01

We examine climatologies derived from eight years of temperature, water vapor, cloud, and trace gas observations made by the Atmospheric Infrared Sounder (AIRS) instrument flying on the Aqua satellite and compare them to similar climatologies constructed with data from a global assimilation model, the Modern Era Retrospective-Analysis for Research and Applications (MERRA). We use the AIRS climatologies to examine anomalies and trends in the AIRS data record. Since sampling can be an issue for infrared satellites in low earth orbit, we also use the MERRA data to examine the AIRS sampling biases. By sampling the MERRA data at the AIRS space-time locations both with and without the AIRS quality control we estimate the sampling bias of the AIRS climatology and the atmospheric conditions where AIRS has a lower sampling rate. While the AIRS temperature and water vapor sampling biases are small at low latitudes, they can be more than a few degrees in temperature or 10 percent in water vapor at higher latitudes. The largest sampling biases are over desert. The AIRS and MERRA data are available from the Goddard Earth Sciences Data and Information Services Center (GES DISC). The AIRS climatologies we used are available for analysis with the GIOVANNI data exploration tool. (see, http://disc.gsfc.nasa.gov).

Aerosols and Particulates Workshop Sampling Procedures and Venues Working Group Summary

NASA Technical Reports Server (NTRS)

Pachlhofer, Peter; Howard, Robert

1999-01-01

The Sampling Procedures and Venues Workgroup discussed the potential venues available and issues associated with obtaining measurements. Some of the issues included Incoming Air Quality, Sampling Locations, Probes and Sample Systems. The following is a summary of the discussion of the issues and venues. The influence of inlet air to the measurement of exhaust species, especially trace chemical species, must be considered. Analysis procedures for current engine exhaust emissions regulatory measurements require adjustments for air inlet humidity. As a matter of course in scientific investigations, it is recommended that "background" measurements for any species, particulate or chemical, be performed during inlet air flow before initiation of combustion, if possible, and during the engine test period as feasible and practical. For current regulatory measurements, this would be equivalent to setting the "zero" level for conventional gas analyzers. As a minimum, it is recommended that measurements of the humidity and particulates in the incoming air be taken at the start and end of each test run. Additional measurement points taken during the run are desirable if they can be practically obtained. It was felt that the presence of trace gases in the incoming air is not a significant problem. However, investigators should consider the ambient levels and influences of local air pollution for species of interest. Desired measurement locations depend upon the investigation requirements. A complete investigation of phenomenology of particulate formation and growth requires measurements at a number of locations both within the engine and in the exhaust field downstream of the nozzle exit plane. Desirable locations for both extractive and in situ measurements include: (1) Combustion Zone (Multiple axial locations); (2) Combustor Exit (Multiple radial locations for annular combustors); (3) Turbine Stage (Inlet and exit of the stage); (4) Exit Nozzle (Multiple axial locations downstream of the nozzle). Actual locations with potential for extractive or non-intrusive measurements depend upon the test article and test configuration. Committee members expressed the importance of making investigators aware of various ports that could allow access to various stages of the existing engines. Port locations are engine si)ecific and might allow extractive sampling or innovative hybrid optical-probe access. The turbine stage region was one the most desirable locations for obtaining samples and might be accessed through boroscope ports available in some engine designs. Discussions of probes and sampling systems quickly identified issues dependent on particular measurement quantities. With general consensus, the group recommends SAE procedures for measurements and data analyses of currently regulated exhaust species (CO2, CO, THC, NO(x),) using conventional gas sampling techniques. Special procedures following sound scientific practices must be developed as required for species and/or measurement conditions not covered by SAE standards. Several issues arose concerning short lived radicals and highly reactive species. For conventional sampling, there are concerns of perturbing the sample during extraction, line losses, line-wall reactions, and chemical reactions during the sample transport to the analyzers. Sample lines coated with quartz.or other materials should be investigated for minimization of such effects. The group advocates the development of innovative probe techniques and non-intrusive optical techniques for measurement of short lived radicals and highly reactive species that cannot be sampled accurately otherwise. Two innovative probe concepts were discussed. One concept uses specially designed probes to transfer optical beams to and from a region of flow inaccessible by traditional ports or windows. The probe can perturb the flow field but must have a negligible impact on the region to be optically sampled. Such probes are referred to as hybrid probes and are under development at AEDC for measurement in the high pressure, high temperature of a combustor under development for power generation. The other concept consists of coupling an instrument directly to the probe. The probe would isolate a representative sample stream, freeze chemical reactions and direct the sample into the analyzer portion of the probe. Thus, the measurement would be performed in situ without sample line losses due either to reactions or binding at the wall surfaces. This concept was used to develop a fast, in situ, time-of-flight mass spectrometer measurement system for temporal quantification of NO in the IMPULSE facility at AEDC. Additional work is required in this area to determine the best probe and sampling technique for each species measurement requirement identified by the Trace Chemistry Working Group. A partial list of Venues was used as a baseline for discussion. Additional venues were added to the list and the list was broken out into the following categories: (1)Engines (a) Sea Level Test Stands (b) Altitude Chambers; (2) Annular Combustor Test Stands, (3) Sector Flametube Test Stands, (4) Fundamentals Rigs/Experiments.

Statistics of Storm Updraft Velocities from TWP-ICE Including Verification with Profiling Measurements

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

Collis, Scott; Protat, Alain; May, Peter T.

2013-08-01

Comparisons between direct measurements and modeled values of vertical air motions in precipitating systems are complicated by differences in temporal and spatial scales. On one hand, vertically profiling radars more directly measure the vertical air motion but do not adequately capture full storm dynamics. On the other hand, vertical air motions retrieved from two or more scanning Doppler radars capture the full storm dynamics but require model constraints that may not capture all updraft features because of inadequate sampling, resolution, numerical constraints, and the fact that the storm is evolving as it is scanned by the radars. To investigate themore » veracity of radar-based retrievals, which can be used to verify numerically modeled vertical air motions, this article presents several case studies from storm events around Darwin, Northern Territory, Australia, in which measurements from a dual-frequency radar profiler system and volumetric radar-based wind retrievals are compared. While a direct comparison was not possible because of instrumentation location, an indirect comparison shows promising results, with volume retrievals comparing well to those obtained from the profiling system. This prompted a statistical analysis of an extended period of an active monsoon period during the Tropical Warm Pool International Cloud Experiment (TWP-ICE). Results show less vigorous deep convective cores with maximum updraft velocities occurring at lower heights than some cloudresolving modeling studies suggest. 1. Introduction The regionalization of global climate models has been a driver of demand for more complex convective parameterization schemes. A key readjustment of the modeled atmosphere« less

Physicochemical and toxicological characteristics of urban aerosols during a recent Indonesian biomass burning episode.

PubMed

Pavagadhi, Shruti; Betha, Raghu; Venkatesan, Shriram; Balasubramanian, Rajasekhar; Hande, Manoor Prakash

2013-04-01

Air particulate matter (PM) samples were collected in Singapore from 21 to 29 October 2010. During this time period, a severe regional smoke haze episode lasted for a few days (21-23 October). Physicochemical and toxicological characteristics of both haze and non-haze aerosols were evaluated. The average mass concentration of PM2.5 (PM with aerodynamic diameter of ≤2.5 μm) increased by a factor of 4 during the smoke haze period (107.2 μg/m(3)) as compared to that during the non-smoke haze period (27.0 μg/m(3)). The PM2.5 samples were analyzed for 16 priority polycyclic aromatic hydrocarbons (PAHs) listed by the United States Environmental Protection Agency and 10 transition metals. Out of the seven PAHs known as potential or suspected carcinogens, five were found in significantly higher levels in smoke haze aerosols as compared to those in the background air. Metal concentrations were also found to be higher in haze aerosols. Additionally, the toxicological profile of the PM2.5 samples was evaluated using a human epithelial lung cell line (A549). Cell viability and death counts were measured after a direct exposure of PM2.5 samples to A459 cells for a period of 48 h. The percentage of metabolically active cells decreased significantly following a direct exposure to PM samples collected during the haze period. To provide further insights into the toxicological characteristics of the aerosol particles, glutathione levels, as an indirect measure of oxidative stress and caspase-3/7 levels as a measure of apoptotic death, were also evaluated.

MULTI-SITE EVALUATIONS OF CANDIDATE METHODOLOGIES FOR DETERMINING COARSE PARTICULATE (PM 10-2.5) CONCENTRATIONS: AUGUST 2005 UPDATED REPORT REGARDING SECOND-GENERATION AND NEW PM 10-2.5 SAMPLERS

EPA Science Inventory

Multi-site field studies were conducted to evaluate the performance of sampling methods for measuring the coarse fraction of PM10 (PM10 2.5) in ambient air. The field studies involved the use of both time-integrated filter-based and direct continuous methods. Despite operationa...

Generator and Setup for Emulating Exposures of Biological Samples to Lightning Strokes.

PubMed

Rebersek, Matej; Marjanovic, Igor; Begus, Samo; Pillet, Flavien; Rols, Marie-Pierre; Miklavcic, Damijan; Kotnik, Tadej

2015-10-01

We aimed to develop a system for controlled exposure of biological samples to conditions they experience when lightning strikes their habitats. We based the generator on a capacitor charged via a bridge rectifier and a dc-dc converter, and discharged via a relay, delivering arcs similar to natural lightning strokes in electric current waveform and similarly accompanied by acoustic shock waves. We coupled the generator to our exposure chamber described previously, measured electrical and acoustic properties of arc discharges delivered, and assessed their ability to inactivate bacterial spores. Submicrosecond discharges descended vertically from the conical emitting electrode across the air gap, entering the sample centrally and dissipating radially toward the ring-shaped receiving electrode. In contrast, longer discharges tended to short-circuit the electrodes. Recording at 341 000 FPS with Vision Research Phantom v2010 camera revealed that initial arc descent was still vertical, but became accompanied by arcs leaning increasingly sideways; after 8-12 μs, as the first of these arcs formed direct contact with the receiving electrode, it evolved into a channel of plasmified air and short-circuited the electrodes. We eliminated this artefact by incorporating an insulating cylinder concentrically between the electrodes, precluding short-circuiting between them. While bacterial spores are highly resistant to electric pulses delivered through direct contact, we showed that with arc discharges accompanied by an acoustic shock wave, spore inactivation is readily obtained. The presented system allows scientific investigation of effects of arc discharges on biological samples. This system will allow realistic experimental studies of lightning-triggered horizontal gene transfer and assessment of its role in evolution.

Mercury contamination of aquatic ecosystems

USGS Publications Warehouse

Krabbenhoft, David P.; Rickert, David A.

1995-01-01

Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emissions from human-related activities. Human health concerns arise when fish and wildlife from these ecosystems are consumed by humans. During the past decade, a new trend has emerged with regard to mercury pollution. Investigations initiated in the late 1980's in the northern-tier states of the U.S., Canada, and Nordic countries found that fish, mainly from nutrient-poor lakes and often in very remote areas, commonly have high levels of mercury. More recent fish sampling surveys in other regions of the U.S. have shown widespread mercury contamination in streams, wet-lands, reservoirs, and lakes. To date, 33 states have issued fish consumption advisories because of mercury contamination. These continental to global scale occurrences of mercury contamination cannot be linked to individual emissions of mercury, but instead are due to widespread air pollution. When scientists measure mercury levels in air and surface water, however, the observed levels are extraordinarily low. In fact, scientists have to take extreme precautions to avoid direct contact with water samples or sample containers, to avert sample contamination (Fig 3). Herein lies an apparent discrepancy: Why do fish from some remote areas have elevated mercury concentrations, when contamination levels in the environment are so low?

Method and apparatus for duct sealing using a clog-resistant insertable injector

DOEpatents

Wang, Duo; Modera, Mark P.

2010-12-14

A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

Environmental and individual PAH exposures near rural natural gas extraction.

PubMed

Paulik, L Blair; Hobbie, Kevin A; Rohlman, Diana; Smith, Brian W; Scott, Richard P; Kincl, Laurel; Haynes, Erin N; Anderson, Kim A

2018-05-29

Natural gas extraction (NGE) has expanded rapidly in the United States in recent years. Despite concerns, there is little information about the effects of NGE on air quality or personal exposures of people living or working nearby. Recent research suggests NGE emits polycyclic aromatic hydrocarbons (PAHs) into air. This study used low-density polyethylene passive samplers to measure concentrations of PAHs in air near active (n = 3) and proposed (n = 2) NGE sites. At each site, two concentric rings of air samplers were placed around the active or proposed well pad location. Silicone wristbands were used to assess personal PAH exposures of participants (n = 19) living or working near the sampling sites. All samples were analyzed for 62 PAHs using GC-MS/MS, and point sources were estimated using the fluoranthene/pyrene isomer ratio. ∑PAH was significantly higher in air at active NGE sites (Wilcoxon rank sum test, p < 0.01). PAHs in air were also more petrogenic (petroleum-derived) at active NGE sites. This suggests that PAH mixtures at active NGE sites may have been affected by direct emissions from petroleum sources at these sites. ∑PAH was also significantly higher in wristbands from participants who had active NGE wells on their properties than from participants who did not (Wilcoxon rank sum test, p < 0.005). There was a significant positive correlation between ∑PAH in participants' wristbands and ∑PAH in air measured closest to participants' homes or workplaces (simple linear regression, p < 0.0001). These findings suggest that living or working near an active NGE well may increase personal PAH exposure. This work also supports the utility of the silicone wristband to assess personal PAH exposure. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

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

High-precision diode-laser-based temperature measurement for air refractive index compensation.

PubMed

Hieta, Tuomas; Merimaa, Mikko; Vainio, Markku; Seppä, Jeremias; Lassila, Antti

2011-11-01

We present a laser-based system to measure the refractive index of air over a long path length. In optical distance measurements, it is essential to know the refractive index of air with high accuracy. Commonly, the refractive index of air is calculated from the properties of the ambient air using either Ciddor or Edlén equations, where the dominant uncertainty component is in most cases the air temperature. The method developed in this work utilizes direct absorption spectroscopy of oxygen to measure the average temperature of air and of water vapor to measure relative humidity. The method allows measurement of temperature and humidity over the same beam path as in optical distance measurement, providing spatially well-matching data. Indoor and outdoor measurements demonstrate the effectiveness of the method. In particular, we demonstrate an effective compensation of the refractive index of air in an interferometric length measurement at a time-variant and spatially nonhomogeneous temperature over a long time period. Further, we were able to demonstrate 7 mK RMS noise over a 67 m path length using a 120 s sample time. To our knowledge, this is the best temperature precision reported for a spectroscopic temperature measurement. © 2011 Optical Society of America

Turboprop engine and method of operating the same

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

Klees, G.W.; Johnson, P.E.

1986-02-11

This patent describes a turboprop engine consisting of: 1.) A compressor; 2.) A turbine; 3.) A combustion section; 4.) A variable pitch propeller; 5.) A speed reducing transmission; 6.) An air inlet; 7.) An air inlet bypass; 8.) An air outlet bypass duct; 9.) A flow control operatively positioned to receive air flow from the air inlet bypass and air flow from the low pressure compressor component. To direct the air flow to the air outlet bypass duct, and the air flow to the high pressure compressor component, the flow control has a first position where the air flow ismore » from. The high and low pressure compressor components and is directed to the air outlet bypass duct. The flow control has a second position for the air flow from the air inlet bypass duct to the air outlet bypass duct and air from the low pressure compressor component is directed to the high pressure compressor component. A method of operating a turboprop engine.« less

Screening portal, system and method of using same

DOEpatents

Linker, Kevin L.; Hunter, John A.; Brusseau, Charles A.

2013-04-30

A portal, system and method for screening an object for a target substance is provided. The portal includes an inflatable bladder expandable to form a test space for receiving the object and a plurality of nozzles positioned about the inflatable bladder. The nozzles are in fluid communication with a fluid source for directing air over the object whereby samples are removed from the object for examination. A collector is operatively connected to the inflatable bladder for collecting the samples removed from the object. A detector is operatively connected to the collector for examining the removed samples for the presence of the target substance. At least one preconcentrator may be operatively connected to the collector for concentrating the samples collected thereby.

Application of ion chromatography for the determination of inorganic ions, especially thiocyanates, in human semen samples as biomarkers of environmental tobacco smoke exposure.

PubMed

Demkowska, Ilona; Polkowska, Żaneta; Kiełbratowska, Bogumiła; Namieśnik, Jacek

2010-11-01

Tobacco smoking constitutes a significant source of indoor air pollution. Various chemical compounds that are emitted during tobacco smoking can have a direct cytotoxic effect on spermatozoa by damaging DNA. There is some evidence that tobacco smoking in men could affect male fertility. The goals of this study were to find relationships between thiocyanates (as biomarkers of environmental tobacco smoke exposure) and other inorganic ions in human semen samples and present the effectiveness of the proposed sample preparation procedure combined with ion chromatography technique for the determination of inorganic ions, especially thiocyanates, in human semen samples collected from heavy, moderate, and passive smokers, as well as nonsmoking individuals.

Extensive severe fever with thrombocytopenia syndrome virus contamination in surrounding environment in patient rooms.

PubMed

Ryu, B-H; Kim, J Y; Kim, T; Kim, M-C; Kim, M J; Chong, Y-P; Lee, S-O; Choi, S-H; Kim, Y S; Woo, J H; Kim, S-H

2018-01-31

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease in Korea and China. Although there is previous evidence of person-to-person transmission via direct contact with body fluids, the role of environmental contamination by SFTS virus (SFTSV) in healthcare settings has not been established. We therefore investigated the contamination of the healthcare environment by SFTSV. We investigated the possible contamination of hospital air and surfaces with SFTSV transmission by collecting air and swabbing environmental surface samples in two hospitals treating six SFTS patients between March and September 2017. The samples were tested using real-time RT-PCR for SFTS M and S segments. Of the six SFTS patients, four received mechanical ventilation and three died. Five rooms were occupied by those using mechanical ventilation or total plasma exchange therapy in isolation rooms without negative pressure and one room was occupied by a patient bedridden due to SFTS. SFTSV was detected in 14 (21%) of 67 swab samples. Five of 24 swab samples were obtained from fomites including stethoscopes, and 9 of 43 were obtained from fixed structures including doorknobs and bed guardrails. Some samples from fixed structures such as television monitors and sink tables were obtained in areas remote from the patients. SFTSV RNA was not detected in five air samples from three patients' rooms. Our data suggest that SFTSV contamination was extensive in surrounding environments in SFTS patients' rooms. Therefore, more strict isolation methods and disinfecting procedures should be considered when managing SFTS patients. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Integration of biomonitoring and instrumental techniques to assess the air quality in an industrial area located in the coastal of central Asturias, Spain.

PubMed

Almeida, Susana Marta; Lage, Joana; Freitas, Maria do Carmo; Pedro, Ana Isabel; Ribeiro, Tiago; Silva, Alexandra Viana; Canha, Nuno; Almeida-Silva, Marina; Sitoe, Timóteo; Dionisio, Isabel; Garcia, Sílvia; Domingues, Gonçalo; de Faria, Julia Perim; Fernández, Beatriz González; Ciaparra, Diane; Wolterbeek, Hubert T

2012-01-01

Throughout the world, epidemiological studies were established to examine the relationship between air pollution and mortality rates and adverse respiratory health effects. However, despite the years of discussion the correlation between adverse health effects and atmospheric pollution remains controversial, partly because these studies are frequently restricted to small and well-monitored areas. Monitoring air pollution is complex due to the large spatial and temporal variations of pollution phenomena, the high costs of recording instruments, and the low sampling density of a purely instrumental approach. Therefore, together with the traditional instrumental monitoring, bioindication techniques allow for the mapping of pollution effects over wide areas with a high sampling density. In this study, instrumental and biomonitoring techniques were integrated to support an epidemiological study that will be developed in an industrial area located in Gijon in the coastal of central Asturias, Spain. Three main objectives were proposed to (i) analyze temporal patterns of PM₁₀ concentrations in order to apportion emissions sources, (ii) investigate spatial patterns of lichen conductivity to identify the impact of the studied industrial area in air quality, and (iii) establish relationships amongst lichen conductivity with some site-specific characteristics. Samples of the epiphytic lichen Parmelia sulcata were transplanted in a grid of 18 by 20 km with an industrial area in the center. Lichens were exposed for a 5-mo period starting in April 2010. After exposure, lichen samples were soaked in 18-MΩ water aimed at determination of water electrical conductivity and, consequently, lichen vitality and cell damage. A marked decreasing gradient of lichens conductivity relative to distance from the emitting sources was observed. Transplants from a sampling site proximal to the industrial area reached values 10-fold higher than levels far from it. This finding showed that lichens reacted physiologically in the polluted industrial area as evidenced by increased conductivity correlated to contamination level. The integration of temporal PM₁₀ measurements and analysis of wind direction corroborated the importance of this industrialized region for air quality measurements and identified the relevance of traffic for the urban area.

Air bubbles and hemolysis of blood samples during transport by pneumatic tube systems.

PubMed

Mullins, Garrett R; Bruns, David E

2017-10-01

Transport of blood samples through pneumatic tube systems (PTSs) generates air bubbles in transported blood samples and, with increasing duration of transport, the appearance of hemolysis. We investigated the role of air-bubble formation in PTS-induced hemolysis. Air was introduced into blood samples for 0, 1, 3 or 5min to form air bubbles. Hemolysis in the blood was assessed by (H)-index, lactate dehydrogenase (LD) and potassium in plasma. In an effort to prevent PTS-induced hemolysis, blood sample tubes were completely filled, to prevent air bubble formation, and compared with partially filled samples after PTS transport. We also compared hemolysis in anticoagulated vs clotted blood subjected to PTS transport. As with transport through PTSs, the duration of air bubble formation in blood by a gentle stream of air predicted the extent of hemolysis as measured by H-index (p<0.01), LD (p<0.01), and potassium (p<0.02) in plasma. Removing air space in a blood sample prevented bubble formation and fully protected the blood from PTS-induced hemolysis (p<0.02 vs conventionally filled collection tube). Clotted blood developed less foaming during PTS transport and was partially protected from hemolysis vs anticoagulated blood as indicated by lower LD (p<0.03) in serum than in plasma after PTS sample transport. Prevention of air bubble formation in blood samples during PTS transport protects samples from hemolysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Uncertainties in monitoring of SVOCs in air caused by within-sampler degradation during active and passive air sampling

NASA Astrophysics Data System (ADS)

Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Prokeš, Roman; Kukučka, Petr; Přibylová, Petra; Vojta, Šimon; Kohoutek, Jiří; Lammel, Gerhard; Klánová, Jana

2017-10-01

Degradation of semivolatile organic compounds (SVOCs) occurs naturally in ambient air due to reactions with reactive trace gases (e.g., ozone, NOx). During air sampling there is also the possibility for degradation of SVOCs within the air sampler, leading to underestimates of ambient air concentrations. We investigated the possibility of this sampling artifact in commonly used active and passive air samplers for seven classes of SVOCs, including persistent organic pollutants (POPs) typically covered by air monitoring programs, as well as SVOCs of emerging concern. Two active air samplers were used, one equipped with an ozone denuder and one without, to compare relative differences in mass of collected compounds. Two sets of passive samplers were also deployed to determine the influence of degradation during longer deployment times in passive sampling. In active air samplers, comparison of the two sampling configurations suggested degradation of particle-bound polycyclic aromatic hydrocarbons (PAHs), with concentrations up to 2× higher in the denuder-equipped sampler, while halogenated POPs did not have clear evidence of degradation. In contrast, more polar, reactive compounds (e.g., organophosphate esters and current use pesticides) had evidence of losses in the sampler with denuder. This may be caused by the denuder itself, suggesting sampling bias for these compounds can be created when typical air sampling apparatuses are adapted to limit degradation. Passive air samplers recorded up to 4× higher concentrations when deployed for shorter consecutive sampling periods, suggesting that within-sampler degradation may also be relevant in passive air monitoring programs.

Aerosol Sampling Experiment on the International Space Station

NASA Technical Reports Server (NTRS)

Meyer, Marit E.

2017-01-01

The International Space Station (ISS) is a unique indoor environment which serves as both home and workplace to the astronaut crew. There is currently no particulate monitoring, although particulate matter requirements exist. An experiment to collect particles in the ISS cabin was conducted recently. Two different aerosol samplers were used for redundancy and to collect particles in two size ranges spanning from 10 nm to hundreds of micrometers. The Active Sampler is a battery operated thermophoretic sampler with an internal pump which draws in air and collects particles directly on a transmission electron microscope grid. This commercial-off-the-shelf device was modified for operation in low gravity. The Passive Sampler has five sampling surfaces which were exposed to air for different durations in order to collect at least one sample with an optimal quantity of particles for microscopy. These samples were returned to Earth for analysis with a variety of techniques to obtain long-term average concentrations and identify particle emission sources. Results are compared with the inventory of ISS aerosols which was created based on sparse data and the literature. The goal of the experiment is to obtain data on indoor aerosols on ISS for future particulate monitor design and development.

Multiple-element semiquantitative analysis of one-milligram geochemical samples by D.C. arc emission spectrography

USGS Publications Warehouse

Rait, N.

1981-01-01

A modified method is described for a 1-mg sample multi-element semiquantitative spectrographic analysis. This method uses a direct-current arc source, carbon instead of graphite electrodes, and an 80% argon-20% oxygen atmosphere instead of air. Although this is a destructive method, an analysis can be made for 68 elements in all mineral and geochemical samples. Carbon electrodes have been an aid in improving the detection limits of many elements. The carbon has a greater resistance to heat conductance and develops a better tip, facilitating sample volatilization and counter balancing the cooling effect of a flow of the argon-oxygen mixture around the anode. Where such an argon-oxygen atmosphere is used instead of air, the cyanogen band lines are greatly diminished in intensity, and thus more spectral lines of analysis elements are available for use; the spectral background is also lower. The main advantage of using the carbon electrode and the 80% argon-20% oxygen atmosphere is the improved detection limits of 36 out of 68 elements. The detection limits remain the same for 23 elements, and are not as good for only nine elements. ?? 1981.

A method to estimate spatiotemporal air quality in an urban traffic corridor.

PubMed

Singh, Nongthombam Premananda; Gokhale, Sharad

2015-12-15

Air quality exposure assessment using personal exposure sampling or direct measurement of spatiotemporal air pollutant concentrations has difficulty and limitations. Most statistical methods used for estimating spatiotemporal air quality do not account for the source characteristics (e.g. emissions). In this study, a prediction method, based on the lognormal probability distribution of hourly-average-spatial concentrations of carbon monoxide (CO) obtained by a CALINE4 model, has been developed and validated in an urban traffic corridor. The data on CO concentrations were collected at three locations and traffic and meteorology within the urban traffic corridor.(1) The method has been developed with the data of one location and validated at other two locations. The method estimated the CO concentrations reasonably well (correlation coefficient, r≥0.96). Later, the method has been applied to estimate the probability of occurrence [P(C≥Cstd] of the spatial CO concentrations in the corridor. The results have been promising and, therefore, may be useful to quantifying spatiotemporal air quality within an urban area. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of delta9-tetrahydrocannabinol in indoor air as an indicator of marijuana cigarette smoking using adsorbent sampling and in-injector thermal desorption gas chromatography-mass spectrometry.

PubMed

Chou, Su-Lien; Ling, Yong-Chien; Yang, Mo-Hsiung; Pai, Chung-Yen

2007-08-13

The marijuana leaves are usually mixed with tobaccos and smoked at amusement places in Taiwan. Recently, for investigation-legal purposes, the police asked if we can identify the marijuana smoke in a KTV stateroom (a private room at the entertainment spot for singing, smoking, alcohol drinking, etc.) without marijuana residues. A personal air-sampler pump fitted with the GC liner-tube packed with Tenax-TA adsorbent was used for air sampling. The GC-adsorbent tube was placed in the GC injector port and desorbed directly, followed by GC-MS analysis for the determination of delta9-tetrahydrocannabinol (delta9-THC) in indoor air. The average desorption efficiency and limit of detection for delta9-THC were 89% and 0.1 microg m(-3), respectively, approximately needing 1.09 mg of marijuana leaves smoked in an unventilated closed room (3.0 m x 2.4 m x 2.7 m) to reach this level. The mean delta9-THC contained in the 15 marijuana plants seized from diverse locations was measured to be 0.32%. The delta9-THC in room air can be successfully identified from mock marijuana cigarettes, mixtures of marijuana and tobacco, and an actual case. The characteristic delta9-THC peak in chromatogram can serve as the indicator of marijuana. Positive result suggests marijuana smoking at the specific scene in the recent past, facilitating the formulation of further investigation.

Field-testing a new directional passive air sampler for fugitive dust in a complex industrial source environment.

PubMed

Ferranti, E J S; Fryer, M; Sweetman, A J; Garcia, M A Solera; Timmis, R J

2014-01-01

Quantifying the sources of fugitive dusts on complex industrial sites is essential for regulation and effective dust management. This study applied two recently-patented Directional Passive Air Samplers (DPAS) to measure the fugitive dust contribution from a Metal Recovery Plant (MRP) located on the periphery of a major steelworks site. The DPAS can collect separate samples for winds from different directions (12 × 30° sectors), and the collected dust may be quantified using several different measurement methods. The DPASs were located up and down-prevailing-wind of the MRP processing area to (i) identify and measure the contribution made by the MRP processing operation; (ii) monitor this contribution during the processing of a particularly dusty material; and (iii) detect any changes to this contribution following new dust-control measures. Sampling took place over a 12-month period and the amount of dust was quantified using photographic, magnetic and mass-loading measurement methods. The DPASs are able to effectively resolve the incoming dust signal from the wider steelworks complex, and also different sources of fugitive dust from the MRP processing area. There was no confirmable increase in the dust contribution from the MRP during the processing of a particularly dusty material, but dust levels significantly reduced following the introduction of new dust-control measures. This research was undertaken in a regulatory context, and the results provide a unique evidence-base for current and future operational or regulatory decisions.

Real time analysis of brain tissue by direct combination of ultrasonic surgical aspiration and sonic spray mass spectrometry.

PubMed

Schäfer, Karl-Christian; Balog, Júlia; Szaniszló, Tamás; Szalay, Dániel; Mezey, Géza; Dénes, Júlia; Bognár, László; Oertel, Matthias; Takáts, Zoltán

2011-10-15

Direct combination of cavitron ultrasonic surgical aspirator (CUSA) and sonic spray ionization mass spectrometry is presented. A commercially available ultrasonic surgical device was coupled to a Venturi easy ambient sonic-spray ionization (V-EASI) source by directly introducing liquified tissue debris into the Venturi air jet pump. The Venturi air jet pump was found to efficiently nebulize the suspended tissue material for gas phase ion production. The ionization mechanism involving solely pneumatic spraying was associated with that of sonic spray ionization. Positive and negative ionization spectra were obtained from brain and liver samples reflecting the primary application areas of the surgical device. Mass spectra were found to feature predominantly complex lipid-type constituents of tissues in both ion polarity modes. Multiply charged peptide anions were also detected. The influence of instrumental settings was characterized in detail. Venturi pump geometry and flow parameters were found to be critically important in ionization efficiency. Standard solutions of phospholipids and peptides were analyzed in order to test the dynamic range, sensitivity, and suppression effects. The spectra of the intact tissue specimens were found to be highly specific to the histological tissue type. The principal component analysis (PCA) and linear discriminant analysis (LDA) based data analysis method was developed for real-time tissue identification in a surgical environment. The method has been successfully tested on post-mortem and ex vivo human samples including astrocytomas, meningeomas, metastatic brain tumors, and healthy brain tissue. © 2011 American Chemical Society

Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air

NASA Astrophysics Data System (ADS)

Lee, Jo Jo; Ghosh, Tushar K.; Loyalka, Sudarshan K.

2018-03-01

The oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deeper oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.

76 FR 66617 - Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-27

... Airworthiness Directives; Erickson Air-Crane Incorporated Model S-64F Helicopters AGENCY: Federal Aviation... the Erickson Air-Crane (Erickson Air-Crane) Model S-64F helicopters. The amendment requires, at..., contact Erickson Air-Crane Incorporated, 3100 Willow Springs Road, P.O. Box 3247, Central Point, OR 97502...

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

Kleinheinz, G.T.; St. John, W.P.

A study was conducted to develop a rapid and reliable method for the collection and incorporation of biofiltration air samples containing volatile organic compounds (VOCs) into the Microtox toxicity testing system. To date, no method exists for this type of assay. A constant stream of VOCs was generated by air stripping compounds from a complex mixture of petroleum hydrocarbons (PHCs). Samples were collected on coconut charcoal ORBO tubes and the VOCs extracted with methylene chloride. The compounds extracted were then solvent exchanged into dimethyl sulfoxide (DMSO) under gaseous nitrogen. The resulting DMSO extract was directly incorporated into the Microtox toxicitymore » testing system. In order to determine the efficiency of the solvent exchange, the VOCs in the DMSO extract were then extracted into hexane and subsequently analyzed using gas chromatography (GC) with a flame ionization detector (FID). It was determined that all but the most volatile VOCs could be effectively transferred from the ORBO tubes to DMSO for Microtox testing. Potential trace amounts of residual methylene chloride in the DMSO extracts showed no adverse effects in the Microtox system when compared to control samples.« less

Methods for Integrated Air Sampling and DNA Analysis for Detection of Airborne Fungal Spores

PubMed Central

Williams, Roger H.; Ward, Elaine; McCartney, H. Alastair

2001-01-01

Integrated air sampling and PCR-based methods for detecting airborne fungal spores, using Penicillium roqueforti as a model fungus, are described. P. roqueforti spores were collected directly into Eppendorf tubes using a miniature cyclone-type air sampler. They were then suspended in 0.1% Nonidet P-40, and counted using microscopy. Serial dilutions of the spores were made. Three methods were used to produce DNA for PCR tests: adding untreated spores to PCRs, disrupting spores (fracturing of spore walls to release the contents) using Ballotini beads, and disrupting spores followed by DNA purification. Three P. roqueforti-specific assays were tested: single-step PCR, nested PCR, and PCR followed by Southern blotting and probing. Disrupting the spores was found to be essential for achieving maximum sensitivity of the assay. Adding untreated spores to the PCR did allow the detection of P. roqueforti, but this was never achieved when fewer than 1,000 spores were added to the PCR. By disrupting the spores, with or without subsequent DNA purification, it was possible to detect DNA from a single spore. When known quantities of P. roqueforti spores were added to air samples consisting of high concentrations of unidentified fungal spores, pollen, and dust, detection sensitivity was reduced. P. roqueforti DNA could not be detected using untreated or disrupted spore suspensions added to the PCRs. However, using purified DNA, it was possible to detect 10 P. roqueforti spores in a background of 4,500 other spores. For all DNA extraction methods, nested PCR was more sensitive than single-step PCR or PCR followed by Southern blotting. PMID:11375150

Summertime tropospheric ozone distributions over central and eastern Canada

NASA Technical Reports Server (NTRS)

Anderson, B. E.; Gregory, G. L.; Barrick, J. D.; Collins, J. E., Jr.; Sachse, G. W.; Shipham, M. C.; Hudgins, C. H.

1994-01-01

Ozone measurements were obtained between the surface and the 6-km altitude on aircraft flights over central and eastern Canada during the summer 1990 NASA Global Tropospheric Experiment Arctic Boundary Layer Expedition (GTE/ABLE 3B). Tropospheric O3 budgets for these regions were observed to be highly variable and significantly impacted by long-range transport and regional scale air mass modification processes. For example, integrated O3 abundance below 5-km altitude averaged 40% and 30% greater in air masses influenced by anthropogenic sources and biomass burning, respectively, than in background (polar) air. Conversely, aged air transported from subtropical areas of the Pacific at times reduced O3 abundance in this height interval by up to 20%. Though intrusion of anthropogenic air was infrequent during the experiment period, the influence of biomass-burning emissions was particularly notable as two thirds of the flights sampled air influenced by plumes from fires burning in Alaska and western Canada. The impinging pollution, both natural and anthropogenic, not only elevated O3 levels directly but also was a source of reactive nitrogen (and nonmethane hydrocarbons) which generally increases the tropospheric lifetime of O3 via moderation of photochemical destruction rates.

The occurrence of fungi, yeasts and bacteria in the air of a Spanish winery during vintage.

PubMed

Garijo, Patrocinio; Santamaría, Pilar; López, Rosa; Sanz, Susana; Olarte, Carmen; Gutiérrez, Ana Rosa

2008-07-15

This research studies the presence of microorganisms of enological interest (yeasts, bacteria and molds) and their evolution in the air of a wine cellar. The samples were taken throughout the winemaking campaign (September-December) in a winery of the D.O.Ca. Rioja, Spain. They were collected using an airIDEAL atmosphere sampler from Biomerieux. For the isolation, specific selective media were used for each group of microorganisms. The results obtained indicate that the presence in the winery air of the various different microorganisms studied is directly related to the winemaking processes that are taking place in the winery. Thus, the number of molds present decreases once grapes have ceased to be brought into the winery. The maximum number of yeasts in the air is found when all the vats in the cellar are fermenting, while the lactic bacteria are not detected until the first malolactic fermentation begins. The species of yeasts and molds identified are also related to the winemaking processes. The coincidence of strains of Saccharomyces cerevisiae among those present in the vats during alcoholic fermentation and those isolated from the air, confirms the role of the latter as a transmitter of microorganisms.

Elemental composition of airborne particulates and source identification - An extensive one year survey. [in Cleveland, OH

NASA Technical Reports Server (NTRS)

King, R. B.; Fordyce, J. S.; Antoine, A. C.; Leibecki, H. F.; Neustadter, H. E.; Sidik, S. M.

1976-01-01

Concentrations of 60 chemical elements in the airborne particulate matter were measured at 16 sites in Cleveland, OH over a 1 year period during 1971 and 1972 (45 to 50 sampling days). Analytical methods used included instrumental neutron activation, emission spectroscopy, and combustion techniques. Uncertainties in the concentrations associated with the sampling procedures, the analytical methods, the use of several analytical facilities, and samples with concentrations below the detection limits are evaluated in detail. The data are discussed in relation to other studies and source origins. The trace constituent concentrations as a function of wind direction are used to suggest a practical method for air pollution source identification.

77 FR 73265 - Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters

Federal Register 2010, 2011, 2012, 2013, 2014

2012-12-10

... Airworthiness Directives; Erickson Air-Crane Incorporated Helicopters AGENCY: Federal Aviation Administration... Erickson Air-Crane Incorporated (Erickson) Model S-64F helicopters. This AD requires inspecting for... service information identified in this AD, contact Erickson Air-Crane Incorporated, ATTN: Chris Erickson...

Effect of air velocity and direction for indirect evaporative cooling in tropical area

NASA Astrophysics Data System (ADS)

Ayodha Ajiwiguna, Tri; Nugraha Rismi, Fadhlin; Ramdlan Kirom, Mukhammad

2017-06-01

In this research, experimental study of heat absorption rate caused by indirect evaporative cooling is performed by varying the velocity and direction of air. The ambient is at average temperature and relative humidity of 28.7 °C and 78% respectively. The experiment is conducted by attaching wet medium on the top of material reference plate with the dimension of 14 x 8 cm with 5 mm thickness. To get evaporative cooling effect, the air flow is directed to the wet medium with velocity from 1.6 m/s to 3.4 m/s with the increment of 0.2 m/s. The direction of air is set 0° (parallel), 45° (inclined), and 90° (perpendicular) to the wet medium surface. While the experiment is being performed, the air temperature, top and bottom of plate temperature are measured simultaneously after steady state condition is established. Based on the measurement result, heat absorption is calculated by analysing the heat conduction on the material reference. The result shows that the heat absorption rate is increased by higher velocity. Perpendicular direction of air flow results the highest cooling capacity compared with other direction. The maximum heat absorption rate is achieved at 13.9 Watt with 3.4 m/s velocity and perpendicular direction of air.

Direct and Indirect Predictors of Social Competence in United States Army Junior Commissioned Officers

DTIC Science & Technology

2005-11-01

colleagues, Professors Eric Heggestad and Charlie Reeve, for making their graduate students available to us for data collection and test scoring...Purdue University, respectively, with little difficulty. We sincerely thank the I/O graduate students and consultants who served as data collectors and...scales in both Air Force enlistee and university undergraduate samples. Justification of Hypothesized Link between General Cognitive Ability and Social

Prevalence of Posttraumatic Stress Disorder in Remotely Piloted Aircraft Operators in the United States Air Force

DTIC Science & Technology

2016-05-24

common feature of the depressive and anxiety disorders: a test of the revised integrative hierarchical model in a national sample. J Abnorm Psychol...proliferation of this unique form of warfare, concerns have been raised regarding the psychological impact such operations have on RPA operators directly...and clinical interviews utilizing the Clinician Administered Psychological Survey to determine the nature of the respondents’ stressful military

Prototypes of Cognitive Measures for Air Force Officers: Test Development and Item Banking

DTIC Science & Technology

1990-05-01

with the complexity of the relationship. Relationships may be in terms of shape, size, dimensionality, area of embeddedness , rotation, blank/shaded...administration were used. Test directions were read from the booklet. Demographics and test responses were recorded on a machine-scannable answer sheet...as demographic information would be needed to determine whether sample characteristics accounted for the differences in mean scores for NC, FA, and WD

AFM Structural Characterization of Drinking Water Biofilm ...

EPA Pesticide Factsheets

Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air and aqueous solution. Operating parameters were optimized to improve imaging of structural details for a mature biofilm in liquid. By using a soft cantilever (0.03 N/m) and slow scan rate (0.5 Hz), biofilm and individual bacterial cell’s structural topography were resolved and continuously imaged in liquid without loss of spatial resolution or sample damage. The developed methodology will allow future in situ investigations to temporally monitor mixed culture drinking water biofilm structural changes during disinfection treatments. Due to the complexity of mixed culture drinking water biofilm, direct visual observation under in situ conditions has been challenging. In this study, atomic force microscopy (AFM) revealed the three dimensional morphology and arrangement of drinking water relevant biofilm in air and aqueous solution. Operating parameters were optimized to improve imaging of structural details for a mature biofilm in liquid. By using a soft cantilever (0.03 N/m) and slow scan rate (0.5 Hz), biofilm and individual bacterial cell’s structural topography were resolved and continuously imaged in liquid without loss of spatial resolution or sample damage. The developed methodo

Annual air pollution caused by the Hungry Ghost Festival.

PubMed

Khezri, B; Chan, Y Y; Tiong, L Y D; Webster, R D

2015-09-01

Burning of joss paper and incense is still a very common traditional custom in countries with a majority Chinese population. The Hungry Ghost Festival which is celebrated in the 7 month of the Chinese calendar is one of the events where joss paper and incense are burned as offerings. This study investigates the impact of the Ghost Month Festival (open burning event) on air quality by analysis of the chemical composition of particulate matter (PM) and rainwater samples collected during this event, compared with data collected throughout the year, as well as bottom ash samples from burning the original joss paper and incense. The results showed that the change in the chemical composition of the rainwater and PM2.5 (PM ≤ 2.5 μm) atmospheric samples could be correlated directly with burning events during this festival, with many elements increasing between 18% and 60% during August and September compared to the yearly mean concentrations. The order of percentage increase in elemental composition (in rain water and PM2.5) during the Hungry Ghost Festival is as follows: Zn > Ca > K > Mg > Fe > Al > Na ∼ Mn ∼ Ti ∼ V > Cu > As > Ni > Co > Cd > Cr > Pb. The chemical composition of the original source materials (joss paper and incense for combustion) and their associated bottom ash were analysed to explain the impact of burning on air quality.

Development and performance assessment of a luminex xMAP® direct hybridization assay for the detection and identification of indoor air fungal contamination.

PubMed

Libert, Xavier; Packeu, Ann; Bureau, Fabrice; Roosens, Nancy H; De Keersmaecker, Sigrid C J

2017-01-01

Considered as a public health problem, indoor fungal contamination is generally monitored using classical protocols based on culturing. However, this culture dependency could influence the representativeness of the fungal population detected in an analyzed sample as this includes the dead and uncultivable fraction. Moreover, culture-based protocols are often time-consuming. In this context, molecular tools are a powerful alternative, especially those allowing multiplexing. In this study a Luminex xMAP® assay was developed for the simultaneous detection of 10 fungal species which are most frequently in indoor air and that may cause health problems. This xMAP® assay was found to be sensitive, i.e. its limit of detection is ranging between 0.05 and 0.01 ng of gDNA. The assay was subsequently tested with environmental air samples which were also analyzed with a classical protocol. All the species identified with the classical method were also detected with the xMAP® assay, however in a shorter time frame. These results demonstrate that the Luminex xMAP® fungal assay developed in this study could contribute to the improvement of public health and specifically to the indoor fungal contamination treatment.

40 CFR 61.34 - Air sampling.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Air sampling. 61.34 Section 61.34... sampling. (a) Stationary sources subject to § 61.32(b) shall locate air sampling sites in accordance with a... concentrations calculated within 30 days after filters are collected. Records of concentrations at all sampling...

NHEXAS PHASE I ARIZONA STUDY--METALS IN AIR ANALYTICAL RESULTS

EPA Science Inventory

The Metals in Air data set contains analytical results for measurements of up to 11 metals in 369 air samples over 175 households. Samples were taken by pumping standardized air volumes through filters at indoor and outdoor sites around each household being sampled. The primary...

Lean direct wall fuel injection method and devices

NASA Technical Reports Server (NTRS)

Choi, Kyung J. (Inventor); Tacina, Robert (Inventor)

2000-01-01

A fuel combustion chamber, and a method of and a nozzle for mixing liquid fuel and air in the fuel combustion chamber in lean direct injection combustion for advanced gas turbine engines, including aircraft engines. Liquid fuel in a form of jet is injected directly into a cylindrical combustion chamber from the combustion chamber wall surface in a direction opposite to the direction of the swirling air at an angle of from about 50.degree. to about 60.degree. with respect to a tangential line of the cylindrical combustion chamber and at a fuel-lean condition, with a liquid droplet momentum to air momentum ratio in the range of from about 0.05 to about 0.12. Advanced gas turbines benefit from lean direct wall injection combustion. The lean direct wall injection technique of the present invention provides fast, uniform, well-stirred mixing of fuel and air. In addition, in order to further improve combustion, the fuel can be injected at a venturi located in the combustion chamber at a point adjacent the air swirler.

Lipid biomarker analysis for the quantitative analysis of airborne microorganisms

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

Macnaughton, S.J.; Jenkins, T.L.; Cormier, M.R.

1997-08-01

There is an ever increasing concern regarding the presence of airborne microbial contaminants within indoor air environments. Exposure to such biocontaminants can give rise to large numbers of different health effects including infectious diseases, allergenic responses and respiratory problems, Biocontaminants typically round in indoor air environments include bacteria, fungi, algae, protozoa and dust mites. Mycotoxins, endotoxins, pollens and residues of organisms are also known to cause adverse health effects. A quantitative detection/identification technique independent of culturability that assays both culturable and non culturable biomass including endotoxin is critical in defining risks from indoor air biocontamination. Traditionally, methods employed for themore » monitoring of microorganism numbers in indoor air environments involve classical culture based techniques and/or direct microscopic counting. It has been repeatedly documented that viable microorganism counts only account for between 0.1-10% of the total community detectable by direct counting. The classic viable microbiologic approach doe`s not provide accurate estimates of microbial fragments or other indoor air components that can act as antigens and induce or potentiate allergic responses. Although bioaerosol samplers are designed to damage the microbes as little as possible, microbial stress has been shown to result from air sampling, aerosolization and microbial collection. Higher collection efficiency results in greater cell damage while less cell damage often results in lower collection efficiency. Filtration can collect particulates at almost 100% efficiency, but captured microorganisms may become dehydrated and damaged resulting in non-culturability, however, the lipid biomarker assays described herein do not rely on cell culture. Lipids are components that are universally distributed throughout cells providing a means to assess independent of culturability.« less

An air pollution episode and its formation mechanism during the tropical cyclone Nuri's landfall in a coastal city of south China

NASA Astrophysics Data System (ADS)

Yang, John Xun; Lau, Alexis Kai Hon; Fung, Jimmy Chi Hung; Zhou, Wen; Wenig, Mark

2012-07-01

In this work we investigated an air pollution episode during the landfall process of a tropical cyclone (TC) in Hong Kong. TCs affect air condition and account for most air pollution episodes in summer of this region. In August 2008, TC Nuri made direct landfall in Hong Kong. Before its landfall, an air pollution episode occurred, where major pollutants like SO2 and PM10 increased eight and six times higher respectively. Rather than using single measurement method, we combined ground air sampling, lidar, sunphotometer and satellite lidar CALIPSO with focus on aerosol to study the episode mechanism, and some new phenomena were found. During the episode, it was found that heavy inland aerosol plumes existed in areas larger than urbanized regions and were elevated vertically and transported southward. During episode, planetary boundary layer (PBL) expansion and height increase were observed, which is different from previous reported PBL compression and height decrease. While vertical subsidence and horizontal stagnation and consequently local aerosol accumulation were attributed as the main episode cause in previous cases, our observation showed that transported aerosols dominated in this TC landfall event. This can be further confirmed by examining aerosol chemical composition, size distribution and single scattering albedo, where transported related species showed significantly change and local indicators remained relatively stable. Invigorated cloud droplets were found on the boundary layer top upon aerosol elevation. The results indicate that site difference and TC tracks should be considered for analyzing episode formation mechanism. They can cause difference in the strength of vertical subsidence and horizontal advection and affect pollution flow direction, which subsequently results in different pollution formation processes.

Use of dust fall filters as passive samplers for metal concentrations in air for communities near contaminated mine tailings

PubMed Central

Beamer, P.I.; Sugeng, A. J.; Kelly, M.D.; Lothrop, N.; Klimecki, W.; Wilkinson, S.T.; Loh, M.

2014-01-01

Mine tailings are a source of metal exposures in many rural communities. Multiple air samples are necessary to assess the extent of exposures and factors contributing to these exposures. However, air sampling equipment is costly and requires trained personnel to obtain measurements, limiting the number of samples that can be collected. Simple, low-cost methods are needed to allow for increased sample collection. The objective of our study was to assess if dust fall filters can serve as passive air samplers and be used to characterize potential exposures in a community near contaminated mine tailings. We placed filters in cylinders, concurrently with active indoor air samplers, in 10 occupied homes. We calculated an estimated flow rate by dividing the mass on each dust fall filter by the bulk air concentration and the sampling duration. The mean estimated flow rate for dust fall filters was significantly different during sampling periods with precipitation. The estimated flow rate was used to estimate metal concentration in the air of these homes, as well as in 31 additional homes in another rural community impacted by contaminated mine tailings. The estimated air concentrations had a significant linear association with the measured air concentrations for beryllium, manganese and arsenic (p<0.05), whose primary source in indoor air is resuspended soil from outdoors. In the second rural community, our estimated metal concentrations in air were comparable to active air sampling measurements taken previously. This passive air sampler is a simple low-cost method to assess potential exposures near contaminated mining sites. PMID:24469149

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.

Exploring prenatal outdoor air pollution, birth outcomes and neonatal health care utilization in a nationally representative sample

PubMed Central

Trasande, Leonardo; Wong, Kendrew; Roy, Angkana; Savitz, David A.; Thurston, George

2015-01-01

The impact of air pollution on fetal growth remains controversial, in part, because studies have been limited to sub-regions of the United States with limited variability. No study has examined air pollution impacts on neonatal health care utilization. We performed descriptive, univariate and multivariable analyses on administrative hospital record data from 222,359 births in the 2000, 2003 and 2006 Kids Inpatient Database linked to air pollution data drawn from the US Environmental Protection Agency’s Aerometric Information Retrieval System. In this study, air pollution exposure during the birth month was estimated based on birth hospital address. Although air pollutants were not individually associated with mean birth weight, a three-pollutant model controlling for hospital characteristics, demographics, and birth month identified 9.3% and 7.2% increases in odds of low birth weight and very low birth weight for each µg/m3 increase in PM2.5 (both P<0.0001). PM2.5 and NO2 were associated with −3.0% odds/p.p.m. and +2.5% odds/p.p.b. of preterm birth, respectively (both P<0.0001). A four-pollutant multivariable model indicated a 0.05 days/p.p.m. NO2 decrease in length of the birth hospitalization (P=0.0061) and a 0.13 days increase/p.p.m. CO (P=0.0416). A $1166 increase in per child costs was estimated for the birth hospitalization per p.p.m. CO (P=0.0002) and $964 per unit increase in O3 (P=0.0448). A reduction from the 75th to the 25th percentile in the highest CO quartile for births predicts annual savings of $134.7 million in direct health care costs. In a national, predominantly urban, sample, air pollutant exposures during the month of birth are associated with increased low birth weight and neonatal health care utilization. Further study of this database, with enhanced control for confounding, improved exposure assessment, examination of exposures across multiple time windows in pregnancy, and in the entire national sample, is supported by these initial investigations. PMID:23340702

Spot Radiative Ignition and Subsequent Three Dimensional Flame Spread Over Thin Cellulose Fuels

NASA Technical Reports Server (NTRS)

Olson, Sandra L.; Kashiwagi, T.; Kikuchi, M.; Fujita, O.; Ito, K.

1999-01-01

Spontaneous radiative ignition and transition to flame spread over thin cellulose fuel samples was studied aboard the USMP-3 STS-75 Space Shuttle mission, and in three test series in the 10 second Japan Microgravity Center (JAMIC). A focused beam from a tungsten/halogen lamp was used to ignite the center of the fuel sample while an external air flow was varied from 0 to 10 cm/s. Non-piloted radiative ignition of the paper was found to occur more easily in microgravity than in normal gravity. Ignition of the sample was achieved under all conditions studied (shuttle cabin air, 21%-50% O2 in JAMIC), with transition to flame spread occurring for all but the lowest oxygen and flow conditions. While radiative ignition in a quiescent atmosphere was achieved, the flame quickly extinguished in air. The ignition delay time was proportional to the gas-phase mixing time, which is estimated using the inverse flow rate. The ignition delay was a much stronger function of flow at lower oxygen concentrations. After ignition, the flame initially spread only upstream, in a fan-shaped pattern. The fan angle increased with increasing external flow and oxygen concentration from zero angle (tunneling flame spread) at the limiting 0.5 cm/s external air flow, to 90 degrees (semicircular flame spread) for external flows at and above 5 cm/s, and higher oxygen concentrations. The fan angle was shown to be directly related to the limiting air flow velocity. Despite the convective heating from the upstream flame, the downstream flame was inhibited due to the 'oxygen shadow' of the upstream flame for the air flow conditions studied. Downstream flame spread rates in air, measured after upstream flame spread was complete and extinguished, were slower than upstream flame spread rates at the same flow. The quench regime for the transition to flame spread was skewed toward the downstream, due to the augmenting role of diffusion for opposed flow flame spread, versus the canceling effect of diffusion at very low cocurrent flows.

Filter for on-line air monitor unaffected by radon progeny and method of using same

DOEpatents

Phillips, Terrance D.; Edwards, Howard D.

1999-01-01

An apparatus for testing air having contaminants and radon progeny therein. The apparatus includes a sampling box having an inlet for receiving the air and an outlet for discharging the air. The sampling box includes a filter made of a plate of sintered stainless steel. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough. A method of testing air having contaminants and radon progeny therein. The method includes providing a testing apparatus that has a sampling box with an inlet for receiving the air and an outlet for discharging the air, and has a sintered stainless steel filter disposed within said sampling box; drawing air from a source into the sampling box using a vacuum pump; passing the air through the filter; monitoring the contaminants trapped by the filter; and providing an alarm when a selected level of contaminants is reached. The filter traps the contaminants, yet allows at least a portion of the radon progeny to pass therethrough.

Airborne detection and quantification of swine influenza a virus in air samples collected inside, outside and downwind from swine barns.

PubMed

Corzo, Cesar A; Culhane, Marie; Dee, Scott; Morrison, Robert B; Torremorell, Montserrat

2013-01-01

Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m³ of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m³ of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m³. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions.

Airborne Detection and Quantification of Swine Influenza A Virus in Air Samples Collected Inside, Outside and Downwind from Swine Barns

PubMed Central

Corzo, Cesar A.; Culhane, Marie; Dee, Scott; Morrison, Robert B.; Torremorell, Montserrat

2013-01-01

Airborne transmission of influenza A virus (IAV) in swine is speculated to be an important route of virus dissemination, but data are scarce. This study attempted to detect and quantify airborne IAV by virus isolation and RRT-PCR in air samples collected under field conditions. This was accomplished by collecting air samples from four acutely infected pig farms and locating air samplers inside the barns, at the external exhaust fans and downwind from the farms at distances up to 2.1 km. IAV was detected in air samples collected in 3 out of 4 farms included in the study. Isolation of IAV was possible from air samples collected inside the barn at two of the farms and in one farm from the exhausted air. Between 13% and 100% of samples collected inside the barns tested RRT-PCR positive with an average viral load of 3.20E+05 IAV RNA copies/m3 of air. Percentage of exhaust positive air samples also ranged between 13% and 100% with an average viral load of 1.79E+04 RNA copies/m3 of air. Influenza virus RNA was detected in air samples collected between 1.5 and 2.1 Km away from the farms with viral levels significantly lower at 4.65E+03 RNA copies/m3. H1N1, H1N2 and H3N2 subtypes were detected in the air samples and the hemagglutinin gene sequences identified in the swine samples matched those in aerosols providing evidence that the viruses detected in the aerosols originated from the pigs in the farms under study. Overall our results indicate that pigs can be a source of IAV infectious aerosols and that these aerosols can be exhausted from pig barns and be transported downwind. The results from this study provide evidence of the risk of aerosol transmission in pigs under field conditions. PMID:23951164

Field Test Evaluation of Conservation Retrofits of Low-Income, Single-Family Buildings in Wisconsin: Blower-Door-Directed Infiltration Reduction Procedure, Field Test Implementation and Results

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

Gettings, M.B.

A blower-door-directed infiltration retrofit procedure was field tested on 18 homes in south central Wisconsin. The procedure, developed by the Wisconsin Energy Conservation Corporation, includes recommended retrofit techniques as well as criteria for estimating the amount of cost-effective work to be performed on a house. A recommended expenditure level and target air leakage reduction, in air changes per hour at 50 Pascal (ACH50), are determined from the initial leakage rate measured. The procedure produced an average 16% reduction in air leakage rate. For the 7 houses recommended for retrofit, 89% of the targeted reductions were accomplished with 76% of themore » recommended expenditures. The average cost of retrofits per house was reduced by a factor of four compared with previous programs. The average payback period for recommended retrofits was 4.4 years, based on predicted energy savings computed from achieved air leakage reductions. Although exceptions occurred, the procedure's 8 ACH50 minimum initial leakage rate for advising retrofits to be performed appeared a good choice, based on cost-effective air leakage reduction. Houses with initial rates of 7 ACH50 or below consistently required substantially higher costs to achieve significant air leakage reductions. No statistically significant average annual energy savings was detected as a result of the infiltration retrofits. Average measured savings were -27 therm per year, indicating an increase in energy use, with a 90% confidence interval of 36 therm. Measured savings for individual houses varied widely in both positive and negative directions, indicating that factors not considered affected the results. Large individual confidence intervals indicate a need to increase the accuracy of such measurements as well as understand the factors which may cause such disparity. Recommendations for the procedure include more extensive training of retrofit crews, checks for minimum air exchange rates to insure air quality, and addition of the basic cost of determining the initial leakage rate to the recommended expenditure level. Recommendations for the field test of the procedure include increasing the number of houses in the sample, more timely examination of metered data to detect anomalies, and the monitoring of indoor air temperature. Though not appropriate in a field test of a procedure, further investigation into the effects of air leakage rate reductions on heating loads needs to be performed.« less

78 FR 18533 - Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-27

... Airworthiness Directives; Lindstrand Hot Air Balloons Ltd Appliances AGENCY: Federal Aviation Administration... Hot Air Balloons Ltd female ACME threaded hose connectors, part numbers HS6139 and HS6144, installed... follows: * * * * * (c) Applicability This AD applies to Lindstrand Hot Air Balloons Ltd female ACME...

U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--METALS IN AIR ANALYTICAL RESULTS

EPA Science Inventory

The Metals in Air data set contains analytical results for measurements of up to 11 metals in 344 air samples over 86 households. Samples were taken by pumping standardized air volumes through filters at indoor and outdoor sites around each household being sampled. The primary ...

Steady state fractionation of heavy noble gas isotopes in a deep unsaturated zone

USGS Publications Warehouse

Seltzer, Alan M.; Severinghaus, Jeffrey P.; Andraski, Brian J.; Stonestrom, David A.

2017-01-01

To explore steady state fractionation processes in the unsaturated zone (UZ), we measured argon, krypton, and xenon isotope ratios throughout a ∼110 m deep UZ at the United States Geological Survey (USGS) Amargosa Desert Research Site (ADRS) in Nevada, USA. Prior work has suggested that gravitational settling should create a nearly linear increase in heavy-to-light isotope ratios toward the bottom of stagnant air columns in porous media. Our high-precision measurements revealed a binary mixture between (1) expected steady state isotopic compositions and (2) unfractionated atmospheric air. We hypothesize that the presence of an unsealed pipe connecting the surface to the water table allowed for direct inflow of surface air in response to extensive UZ gas sampling prior to our first (2015) measurements. Observed isotopic resettling in deep UZ samples collected a year later, after sealing the pipe, supports this interpretation. Data and modeling each suggest that the strong influence of gravitational settling and weaker influences of thermal diffusion and fluxes of CO2 and water vapor accurately describe steady state isotopic fractionation of argon, krypton, and xenon within the UZ. The data confirm that heavy noble gas isotopes are sensitive indicators of UZ depth. Based on this finding, we outline a potential inverse approach to quantify past water table depths from noble gas isotope measurements in paleogroundwater, after accounting for fractionation during dissolution of UZ air and bubbles.

Effect of Air Swirler Configuration on Lean Direct Injector Flow Structure and Combustion Performance with a 7-Point Lean Direct Injector Array

NASA Technical Reports Server (NTRS)

Hicks, Yolanda R.; Tacina, Kathleen M.; Anderson, Robert C.

2017-01-01

This paper examines the fundamentals of fuel-air mixing in a lean direct injection concept. Results are presented to investigate the effects of air swirler angle, element spacing, and center element offset on recirculation zone formation, flame stability and gaseous emissions.

Air Force Chaplains' Perceived Effectiveness on Service Member's Resilience and Satisfaction.

PubMed

Cafferky, Bryan; Norton, Aaron; Travis, Wendy J

2017-01-01

This study examined how 3,777 active duty male United States Air Force service members' (SMs) rank and residence location moderated the associations between perceived chaplain effectiveness, SMs' resilience, family coping, marital satisfaction, and satisfaction with the Air Force (AF). A multiple-sample structural equation model was conducted with four subgroups of SMs who had received chaplain support: enlisted members living on base, enlisted members living off base, officers living on base, and officers living off base. Chaplain effectiveness was significantly related, both directly and indirectly, to SM's spirituality, resilience, family coping, marital satisfaction, and AF satisfaction. Resilience was significantly associated with increased AF satisfaction for all SMs, except for those living on base. However, living on base was found to strengthen the protective factor between family coping and relationship satisfaction. Rank was found to moderate the link between resilience and family coping. Family coping was significantly related to increased relationship satisfaction.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR PREPARATION OF FILTERS AND PUF FOR FIELD COLLECTION OF METALS AND PESTICIDES IN AIR (BCO-L-2.0)

EPA Science Inventory

The purpose of this SOP is to describe the procedures for pre-cleaning filters and polyurethane foam (PUF) plug prior to air sampling with these media. The sampling media are used for sampling indoor air, outdoor air, and personal air. This procedure was followed to ensure consi...

Probing Emissions of Military Cargo Aircraft: Description of a Joint Field Measurement Program

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

Cheng, Mengdawn; Corporan, E.; DeWitt, M.

2008-01-01

Direct emissions of NOx, volatile organic compounds, and particulate matter (PM) by aircraft contribute to the pollutant levels found in the atmosphere. Aircraft emissions can be injected at the ground level or directly at the high altitude in flight. Conversion of the precursor gases into secondary PM is one of the pathways for the increased atmospheric PM. Atmospheric PM interacts with solar radiation altering atmospheric radiation balance and potentially contributing to global and regional climate changes. Also, direct emissions of air toxics, ozone precursors and PM from aircraft in and around civilian airports and military air bases can worsen localmore » air quality in non-attainment and/or maintenance areas. These emissions need to be quantified. However, the current EPA methods for particle emission measurements from such sources, modified Method 5 and Conditional Test Method 039, are gravimetric-based, and it is anticipated that these methods will not be suitable for current and future generations of aircraft turbine engines, whose particle mass emissions are low. To evaluate measurement approaches for military aircraft emissions, two complementary projects were initiated in 2005. A joint field campaign between these two programs was executed during the first week of October 2005 at the Kentucky Air National Guard (KYANG) base in Louisville, KY. This campaign represented the first in a series of field studies for each program funded by the DoD Strategic Environmental Research and Development Program (SERDP) and provided the basis for cross-comparison of the sampling approaches and measurement techniques employed by the respective program teams. This paper describes the overall programmatic of the multi-year SERDP aircraft emissions research and presents a summary of the results from the joint field campaign.« less

An automated atmospheric sampling system operating on 747 airliners

NASA Technical Reports Server (NTRS)

Perkins, P.; Gustafsson, U. R. C.

1975-01-01

An air sampling system that automatically measures the temporal and spatial distribution of selected particulate and gaseous constituents of the atmosphere has been installed on a number of commercial airliners and is collecting data on commercial air routes covering the world. Measurements of constituents related to aircraft engine emissions and other pollutants are made in the upper troposphere and lower stratosphere (6 to 12 km) in support of the Global Air Sampling Program (GASP). Aircraft operated by different airlines sample air at latitudes from the Arctic to Australia. This system includes specialized instrumentation for measuring carbon monoxide, ozone, water vapor, and particulates, a special air inlet probe for sampling outside air, a computerized automatic control, and a data acquisition system. Air constituents and related flight data are tape recorded in flight for later computer processing on the ground.

Optimization of collision/reaction gases for determination of 90Sr in atmospheric particulate matter by inductively coupled plasma tandem mass spectrometry after direct introduction of air via a gas-exchange device

NASA Astrophysics Data System (ADS)

Suzuki, Yoshinari; Ohara, Ryota; Matsunaga, Kirara

2017-09-01

Nuclear power plant accidents release radioactive strontium 90 (90Sr) into the environment. Monitoring of 90Sr, although important, is difficult and time consuming because it emits only beta radiation. We have developed a new analytical system that enables real-time analysis of 90Sr in atmospheric particulate matter with an analytical run time of only 10 min. Briefly, after passage of an air sample through an impactor, a small fraction of the sample is introduced into a gas-exchange device, where the air is replaced by Ar. Then the sample is directly introduced into an inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) system equipped with a collision/reaction cell to eliminate isobaric interferences on 90Sr from 90Zr+, 89Y1H+, and 90Y+. Experiments with various reaction gas conditions revealed that these interferences could be minimized under the following optimized conditions: 1.0 mL min- 1 O2, 10.0 mL min- 1 H2, and 1.0 mL min- 1 NH3. The estimated background equivalent concentration and estimated detection limit of the system were 9.7 × 10- 4 and 3.6 × 10- 4 ng m- 3, respectively, which are equivalent to 4.9 × 10- 6 and 1.8 × 10- 6 Bq cm- 3. Recoveries of Sr in PM2.5 measured by real-time analysis compared to those obtained by simultaneously collection on filter was 53 ± 23%, and using this recovery, the detection limit as PM2.5 was estimated to be 3.4 ± 1.5 × 10- 6 Bq cm- 3. That is, this system enabled detection of 90Sr at concentrations < 5 × 10- 6 Bq cm- 3 even considering the insufficient fusion/vaporization/ionization efficiency of Sr in PM2.5.

HIGH VOLUME INJECTION FOR GCMS ANALYSIS OF PARTICULATE ORGANIC SPECIES IN AMBIENT AIR

EPA Science Inventory

Detection of organic species in ambient particulate matter typically requires large air sample volumes, frequently achieved by grouping samples into monthly composites. Decreasing the volume of air sample required would allow shorter collection times and more convenient sample c...

Temporal variability of air-sea CO2 exchange in a low-emission estuary

NASA Astrophysics Data System (ADS)

Mørk, Eva Thorborg; Sejr, Mikael Kristian; Stæhr, Peter Anton; Sørensen, Lise Lotte

2016-07-01

There is the need for further study of whether global estimates of air-sea CO2 exchange in estuarine systems capture the relevant temporal variability and, as such, the temporal variability of bulk parameterized and directly measured CO2 fluxes was investigated in the Danish estuary, Roskilde Fjord. The air-sea CO2 fluxes showed large temporal variability across seasons and between days and that more than 30% of the net CO2 emission in 2013 was a result of two large fall and winter storms. The diurnal variability of ΔpCO2 was up to 400 during summer changing the estuary from a source to a sink of CO2 within the day. Across seasons the system was suggested to change from a sink of atmospheric CO2 during spring to near neutral during summer and later to a source of atmospheric CO2 during fall. Results indicated that Roskilde Fjord was an annual low-emission estuary, with an estimated bulk parameterized release of 3.9 ± 8.7 mol CO2 m-2 y-1 during 2012-2013. It was suggested that the production-respiration balance leading to the low annual emission in Roskilde Fjord, was caused by the shallow depth, long residence time and high water quality in the estuary. In the data analysis the eddy covariance CO2 flux samples were filtered according to the H2Osbnd CO2 cross-sensitivity assessment suggested by Landwehr et al. (2014). This filtering reduced episodes of contradicting directions between measured and bulk parameterized air-sea CO2 exchanges and changed the net air-sea CO2 exchange from an uptake to a release. The CO2 gas transfer velocity was calculated from directly measured CO2 fluxes and ΔpCO2 and agreed to previous observations and parameterizations.

Comparison of Gravity Wave Temperature Variances from Ray-Based Spectral Parameterization of Convective Gravity Wave Drag with AIRS Observations

NASA Technical Reports Server (NTRS)

Choi, Hyun-Joo; Chun, Hye-Yeong; Gong, Jie; Wu, Dong L.

2012-01-01

The realism of ray-based spectral parameterization of convective gravity wave drag, which considers the updated moving speed of the convective source and multiple wave propagation directions, is tested against the Atmospheric Infrared Sounder (AIRS) onboard the Aqua satellite. Offline parameterization calculations are performed using the global reanalysis data for January and July 2005, and gravity wave temperature variances (GWTVs) are calculated at z = 2.5 hPa (unfiltered GWTV). AIRS-filtered GWTV, which is directly compared with AIRS, is calculated by applying the AIRS visibility function to the unfiltered GWTV. A comparison between the parameterization calculations and AIRS observations shows that the spatial distribution of the AIRS-filtered GWTV agrees well with that of the AIRS GWTV. However, the magnitude of the AIRS-filtered GWTV is smaller than that of the AIRS GWTV. When an additional cloud top gravity wave momentum flux spectrum with longer horizontal wavelength components that were obtained from the mesoscale simulations is included in the parameterization, both the magnitude and spatial distribution of the AIRS-filtered GWTVs from the parameterization are in good agreement with those of the AIRS GWTVs. The AIRS GWTV can be reproduced reasonably well by the parameterization not only with multiple wave propagation directions but also with two wave propagation directions of 45 degrees (northeast-southwest) and 135 degrees (northwest-southeast), which are optimally chosen for computational efficiency.

Annual radiological environmental operating report, Browns Ferry Nuclear Plant, 1991

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

Not Available

1992-04-01

This report describes the environmental radiological monitoring program conducted by TVA in the vicinity of Browns Ferry Nuclear Plant in 1991. The program includes the collection of samples from the environment and the determination of the concentrations of radioactive materials in the samples. Samples are taken from stations in the general area of the plant and from areas not influenced by plant operations. Station locations are selected after careful consideration of the weather patterns and projected radiation doses to the various areas around the plant. Material sampled includes air, water, milk, foods, vegetation, soil, fish, sediment, and direct radiation levels.more » Results from stations near the plant are compared with concentrations from control stations and with preoperational measurements to determine potential impacts of plant operations.« less

Monitoring airborne fungal spores in an experimental indoor environment to evaluate sampling methods and the effects of human activity on air sampling.

PubMed Central

Buttner, M P; Stetzenbach, L D

1993-01-01

Aerobiological monitoring was conducted in an experimental room to aid in the development of standardized sampling protocols for airborne microorganisms in the indoor environment. The objectives of this research were to evaluate the relative efficiencies of selected sampling methods for the retrieval of airborne fungal spores and to determine the effect of human activity on air sampling. Dry aerosols containing known concentrations of Penicillium chrysogenum spores were generated, and air samples were taken by using Andersen six-stage, Surface Air System, Burkard, and depositional samplers. The Andersen and Burkard samplers retrieved the highest numbers of spores compared with the measurement standard, an aerodynamic particle sizer located inside the room. Data from paired samplers demonstrated that the Andersen sampler had the highest levels of sensitivity and repeatability. With a carpet as the source of P. chrysogenum spores, the effects of human activity (walking or vacuuming near the sampling site) on air sampling were also examined. Air samples were taken under undisturbed conditions and after human activity in the room. Human activity resulted in retrieval of significantly higher concentrations of airborne spores. Surface sampling of the carpet revealed moderate to heavy contamination despite relatively low airborne counts. Therefore, in certain situations, air sampling without concomitant surface sampling may not adequately reflect the level of microbial contamination in indoor environments. PMID:8439150

Assessment of trace metal air pollution in Paris using slurry-TXRF analysis on cemetery mosses.

PubMed

Natali, Marco; Zanella, Augusto; Rankovic, Aleksandar; Banas, Damien; Cantaluppi, Chiara; Abbadie, Luc; Lata, Jean -Christophe

2016-12-01

Mosses are useful, ubiquitous accumulation biomonitors and as such can be used for biomonitoring surveys. However, the biomonitoring of atmospheric pollution can be compromised in urban contexts if the targeted biomonitors are regularly disturbed, irregularly distributed, or are difficult to access. Here, we test the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled mosses growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. We focused on Grimmia pulvinata (Hedwig) Smith, a species abundantly found in all studied cemeteries and very common in Europe. The concentration of Al, As, Br, Ca, Ce, Cl, Cr, Cu, Fe, K, Mn, Ni, V, P, Pb, Rb, S, Sr, Ti, and Zn was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method (slurry-TXRF). This method avoids a digestion step, reduces the risk of sample contamination, and works even at low sample quantities. Elemental markers of road traffic indicated that the highest polluted cemeteries were located near the highly frequented Parisian ring road and under the influence of prevailing winds. The sites with the lowest pollution were found not only in the peri-urban cemeteries, adjoining forest or farming landscapes, but also in the large and relatively wooded cemeteries located in the center of Paris. Our results suggest that (1) slurry-TXRF might be successfully used with moss material, (2) G. pulvinata might be a good biomonitor of trace metals air pollution in urban context, and (3) cemetery moss sampling could be a useful complement for monitoring urban areas. Graphical abstract We tested the hypothesis that cemeteries are appropriate moss sampling sites for the evaluation of air pollution in urban areas. We sampled 110 moss cushions (Grimmia pulvinata) growing on gravestones in 21 urban and peri-urban cemeteries in the Paris metropolitan area. The concentration of 20 elements in mosses was determined by a total reflection X-ray fluorescence technique coupled with a slurry sampling method. Statistical analysis revealed that: - Urbanized Parisian areas crossed by traffic roads have the highest polluted cemeteries with a strong influence of main wind direction on the distribution of air pollutants - As expected, small cemeteries with low tree density were heavily polluted - Less obvious, large green spaces such as large cemeteries (Père Lachaise, Montmartre, Montparnasse) in the center of a dense metropolis like Paris present the same level of atmospheric trace metal pollution as cemeteries in less urbanized areas or nearing a very large forest. This suggests that even in densely urbanized areas, there is more spatial variability in pollution distribution than usually assumed and that large urban areas with low traffic and green filters such as trees are likely to intercept air pollutants.

Unanticipated potential cancer risk near metal recycling facilities

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

Raun, Loren, E-mail: raun@rice.edu; Pepple, Karl, E-mail: pepple.karl@epa.gov; Hoyt, Daniel, E-mail: hoyt.daniel@epa.gov

2013-07-15

Metal recycling is an important growing industry. Prior to this study, area sources consisting of metal recycling facilities fell in a category of limited regulatory scrutiny because of assumed low levels of annual emissions. Initiating with community complaints of nuisance from smoke, dust and odor, the Houston Department of Health and Human Services (HDHHS) began a monitoring program outside metal recycler facilities and found metal particulates in outdoor ambient air at levels which could pose a carcinogenic human health risk. In a study of five similar metal recycler facilities which used a torch cutting process, air downwind and outside themore » facility was sampled for eight hours between 6 and 10 times each over 18 months using a mobile laboratory. Ten background locations were also sampled. Iron, manganese, copper, chromium, nickel, lead, cobalt, cadmium and mercury were detected downwind of the metal recyclers at frequencies ranging from 100% of the time for iron to 2% of the time for mercury. Of these metals, chromium, nickel, lead, cobalt, cadmium and mercury were not detected in any sample in the background. Two pairs of samples were analyzed for total chromium and hexavalent chromium to establish a ratio of the fraction of hexavalent chromium in total chromium. This fraction was used to estimate hexavalent chromium at all locations. The carcinogenic risk posed to a residential receptor from metal particulate matter concentrations in the ambient air attributed to the metal recyclers was estimated from each of the five facilities in an effort to rank the importance of this source and inform the need for further investigation. The total risk from these area sources ranged from an increased cancer risk of 1 in 1,000,000 to 6 in 10,000 using the 95th upper confidence limit of the mean of the carcinogenic metal particulate matter concentration, assuming the point of the exposure is the sample location for a residential receptor after accounting for wind direction and the number of shifts that could operate a year. Further study is warranted to better understand the metal air pollution levels in the community and if necessary, to evaluate the feasibility of emission controls and identify operational improvements and best management practices for this industry. This research adds two new aspects to the literature: identification of types and magnitude of metal particulate matter air pollutants associated with a previously unrecognized area source, metal recyclers and their potential risk to health. -- Highlights: • Air monitoring study in response to community complaints found metal contamination. • Metal recyclers found to potentially pose cancer from metal particulates • Chromium, nickel, cobalt and cadmium samples were detected in five metal recyclers. • These metals were not detected in background air samples. • Estimated increased cancer risk ranges from 1 in 1,000,000 to 8 in 10,000.« less

Size distribution and clothing-air partitioning of polycyclic aromatic hydrocarbons generated by barbecue.

PubMed

Lao, Jia-Yong; Wu, Chen-Chou; Bao, Lian-Jun; Liu, Liang-Ying; Shi, Lei; Zeng, Eddy Y

2018-10-15

Barbecue (BBQ) is one of the most popular cooking activities with charcoal worldwide and produces abundant polycyclic aromatic hydrocarbons (PAHs) and particulate matter. Size distribution and clothing-air partitioning of particle-bound PAHs are significant for assessing potential health hazards to humans due to exposure to BBQ fumes, but have not been examined adequately. To address this issue, particle and gaseous samples were collected at 2-m and 10-m distances from a cluster of four BBQ stoves. Personal samplers and cotton clothes were carried by volunteers sitting near the BBQ stoves. Particle-bound PAHs (especially 4-6 rings) derived from BBQ fumes were mostly affiliated with fine particles in the size range of 0.18-1.8 μm. High molecular-weight PAHs were mostly unimodal peaking in fine particles and consequently had small geometric mean diameters and standard deviations. Source diagnostics indicated that particle-bound PAHs in BBQ fumes were generated primarily by combustion of charcoal, fat content in food, and oil. The influences of BBQ fumes on the occurrence of particle-bound PAHs decreased with increasing distance from BBQ stoves, due to increased impacts of ambient sources, especially by petrogenic sources and to a lesser extent by wind speed and direction. Octanol-air and clothing-air partition coefficients of PAHs obtained from personal air samples were significantly correlated to each other. High molecular-weight PAHs had higher area-normalized clothing-air partition coefficients in cotton clothes, i.e., cotton fabrics may be a significant reservoir of higher molecular-weight PAHs. Particle-bound PAHs from barbecue fumes are generated largely from charcoal combustion and food-charred emissions and mainly affiliated with fine particles. Copyright © 2018. Published by Elsevier B.V.

Evaluation of background soil and air polychlorinated biphenyl (PCB) concentrations on a hill at the outskirts of a metropolitan city.

PubMed

Kuzu, S Levent; Saral, Arslan; Güneş, Gülten; Karadeniz, Aykut

2016-07-01

Air and soil sampling was conducted inside a forested area for 22 months. The sampling location is situated to the north of a metropolitan city. Average atmospheric gas and particle concentrations were found to be 180 and 28 pg m(-3) respectively, while that of soil phase was detected to be 3.2 ng g(-1) on dry matter, The congener pairs of PCB#4-10 had the highest contribution to each medium. TEQ concentration was 0.10 pg m(-3), 0.07 pg m(-3), 21.92 pg g(-1), for gas, particle and soil phases, respectively. PCB#126 and PCB#169 contributed to over 99% of the entire TEQ concentrations for each medium. Local sources were investigated by conditional probability function (CPF) and soil/air fugacity. Landfilling area and medical waste incinerator, located to the 8 km northeast, contributed to ambient concentrations, especially in terms of dioxin-like congeners. The industrial settlement (called Dilovasi being to the east southeast of 60 km distant) contributed from southeast direction. Further sources were identified by potential source contribution function (PSCF). Sources at close proximity had high contribution. Air mass transportation from Aliaga industrial region (being to the southwest of 300 km distant) moderately contributed to ambient concentrations. Low molecular weight congeners were released from soil body. 5-CBs and 6-CBs were close to equilibrium state between soil/air interfaces. PCB#171 was close to equilibrium and PCB#180 was likely to evaporate from soil, which constitute 7-CBs. PCB#199, representing 8-CBs deposited to soil. 9-CB (PCB#207) was in equilibrium between soil and air phases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Carter Carburetor Weekly Air Monitoring & Sampling Report - March 7, 2013 - March 13, 2016

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Method and apparatus for reducing cold-phase emissions by utilizing oxygen-enriched intake air

DOEpatents

Poola, Ramesh B.; Sekar, Ramanujam R.; Stork, Kevin C.

1997-01-01

An oxygen-enriched air intake control system for an internal combustion engine includes air directing apparatus to control the air flow into the intake of the engine. During normal operation of the engine, ambient air flowing from an air filter of the engine flows through the air directing apparatus into the intake of the engine. In order to decrease the amount of carbon monoxide (CO) and hydrocarbon (HC) emissions that tend to be produced by the engine during a short period of time after the engine is started, the air directing apparatus diverts for a short period of time following the start up of the engine at least a portion of the ambient air from the air filter through a secondary path. The secondary path includes a selectively permeable membrane through which the diverted portion of the ambient air flows. The selectively permeable membrane separates nitrogen and oxygen from the diverted air so that oxygen enriched air containing from about 23% to 25% oxygen by volume is supplied to the intake of the engine.

Air sampling workshop: October 24-25, 1978

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

Not Available

1979-06-01

A two-day workshop was held in October 1978 on air sampling strategies for the occupational environment. Strategies comprise the elements of implementing an air sampling program including deciding on the extent of sampling, selecting appropriate types of measurement, placing sampling instruments properly, and interpreting sample results correctly. All of these elements are vital in the reliable assessment of occupational exposures yet their coverage in the industrial hygiene literature is meager. Although keyed to a few introductory topics, the agenda was sufficiently informal to accommodate extemporaneous discussion on any subject related to sampling strategies. Questions raised during the workshop mirror themore » status of air sampling strategy as much as the factual information that was presented. It may be concluded from the discussion and questions that air sampling strategy is an elementary state and urgently needs concerted attention from the industrial hygiene profession.« less

An automated atmospheric sampling system operating on 747 airliners

NASA Technical Reports Server (NTRS)

Perkins, P. J.; Gustafsson, U. R. C.

1976-01-01

An air sampling system that automatically measures the temporal and spatial distribution of particulate and gaseous constituents of the atmosphere is collecting data on commercial air routes covering the world. Measurements are made in the upper troposphere and lower stratosphere (6 to 12 km) of constituents related to aircraft engine emissions and other pollutants. Aircraft operated by different airlines sample air at latitudes from the Arctic to Australia. This unique system includes specialized instrumentation, a special air inlet probe for sampling outside air, a computerized automatic control, and a data acquisition system. Air constituent and related flight data are tape recorded in flight for later computer processing on the ground.

Biases in Total Precipitable Water Vapor Climatologies from Atmospheric Infrared Sounder and Advanced Microwave Scanning Radiometer

NASA Technical Reports Server (NTRS)

Fetzer, Eric J.; Lambrigtsen, Bjorn H.; Eldering, Annmarie; Aumann, Hartmut H.; Chahine, Moustafa T.

2006-01-01

We examine differences in total precipitable water vapor (PWV) from the Atmospheric Infrared Sounder (AIRS) and the Advanced Microwave Scanning Radiometer (AMSR-E) experiments sharing the Aqua spacecraft platform. Both systems provide estimates of PWV over water surfaces. We compare AIRS and AMSR-E PWV to constrain AIRS retrieval uncertainties as functions of AIRS retrieved infrared cloud fraction. PWV differences between the two instruments vary only weakly with infrared cloud fraction up to about 70%. Maps of AIRS-AMSR-E PWV differences vary with location and season. Observational biases, when both instruments observe identical scenes, are generally less than 5%. Exceptions are in cold air outbreaks where AIRS is biased moist by 10-20% or 10-60% (depending on retrieval processing) and at high latitudes in winter where AIRS is dry by 5-10%. Sampling biases, from different sampling characteristics of AIRS and AMSR-E, vary in sign and magnitude. AIRS sampling is dry by up to 30% in most high-latitude regions but moist by 5-15% in subtropical stratus cloud belts. Over the northwest Pacific, AIRS samples conditions more moist than AMSR-E by a much as 60%. We hypothesize that both wet and dry sampling biases are due to the effects of clouds on the AIRS retrieval methodology. The sign and magnitude of these biases depend upon the types of cloud present and on the relationship between clouds and PWV. These results for PWV imply that climatologies of height-resolved water vapor from AIRS must take into consideration local meteorological processes affecting AIRS sampling.

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers... Engineers will assign numbers to Real Estate Directives issued by Air Force Regional Civil Engineers. The...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2014 CFR

2014-07-01

... “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol... start “transient” exhaust and dilution air bag samples to the analytical system and process the samples... Section 86.537-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2012 CFR

2012-07-01

... “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol... start “transient” exhaust and dilution air bag samples to the analytical system and process the samples... Section 86.537-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

40 CFR 86.537-90 - Dynamometer test runs.

Code of Federal Regulations, 2013 CFR

2013-07-01

... “transient” formaldehyde exhaust sample, the “transient” dilution air sample bag, the “transient” methanol... start “transient” exhaust and dilution air bag samples to the analytical system and process the samples... Section 86.537-90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS...

The Influence of Directed Air Flow on Combustion in Spark-Ignition Engine

NASA Technical Reports Server (NTRS)

Rothrock, A M; Spencer, R C

1939-01-01

The air movement within the cylinder of the NACA combustion apparatus was regulated by using shrouded inlet valves and by fairing the inlet passage. Rates of combustion were determined at different inlet-air velocities with the engine speed maintained constant and at different engine speeds with the inlet-air velocity maintained approximately constant. The rate of combustion increased when the engine speed was doubled without changing the inlet-air velocity; the observed increase was about the same as the increase in the rate of combustion obtained by doubling the inlet-air velocity without changing the engine speed. Certain types of directed air movement gave great improvement in the reproducibility of the explosions from cycle to cycle, provided that other variables were controlled. Directing the inlet air past the injection valve during injection increased the rate of burning.

Turbomachine rotor with improved cooling

DOEpatents

Hultgren, Kent Goran; McLaurin, Leroy Dixon; Bertsch, Oran Leroy; Lowe, Perry Eugene

1998-01-01

A gas turbine rotor has an essentially closed loop cooling air scheme in which cooling air drawn from the compressor discharge air that is supplied to the combustion chamber is further compressed, cooled, and then directed to the aft end of the turbine rotor. Downstream seal rings attached to the downstream face of each rotor disc direct the cooling air over the downstream disc face, thereby cooling it, and then to cooling air passages formed in the rotating blades. Upstream seal rings attached to the upstream face of each disc direct the heated cooling air away from the blade root while keeping the disc thermally isolated from the heated cooling air. From each upstream seal ring, the heated cooling air flows through passages in the upstream discs and is then combined and returned to the combustion chamber from which it was drawn.

Turbomachine rotor with improved cooling

DOEpatents

Hultgren, K.G.; McLaurin, L.D.; Bertsch, O.L.; Lowe, P.E.

1998-05-26

A gas turbine rotor has an essentially closed loop cooling air scheme in which cooling air drawn from the compressor discharge air that is supplied to the combustion chamber is further compressed, cooled, and then directed to the aft end of the turbine rotor. Downstream seal rings attached to the downstream face of each rotor disc direct the cooling air over the downstream disc face, thereby cooling it, and then to cooling air passages formed in the rotating blades. Upstream seal rings attached to the upstream face of each disc direct the heated cooling air away from the blade root while keeping the disc thermally isolated from the heated cooling air. From each upstream seal ring, the heated cooling air flows through passages in the upstream discs and is then combined and returned to the combustion chamber from which it was drawn. 5 figs.

Novel insights into the dynamics of cold-air drainage and pooling on a gentle slope from fiber-optic distributed temperature sensing

NASA Astrophysics Data System (ADS)

Pfister, Lena; Sigmund, Armin; Olesch, Johannes; Thomas, Christoph

2016-04-01

Urban climate can benefit from cold-air drainage as it may help alleviate the urban heat island. In contrast, stable cold-air pools can damage plants especially in rural areas. In this study, we examined the dynamics of cold-air drainage and pooling in a peri-urban setting over a period of 47 days along a 170 m long slope with an inclination of 1.3° located in the Ecological Botany Gardens of the University of Bayreuth. Air and soil temperatures were measured using distributed temperature sensing of an 2-dimensional fiber-optic array at six heights (-2 cm to 100 cm) along the slope sampling every 1 min and every 1 m. Ancillary measurements of winds, turbulence intensity and momentum exchange were collected using two ultrasonic anemometers installed at 0.1 m and 17 m height at the center of the transect. We hypothesized that cold-air drainage, here defined as a gravity-driven density flow near the bottom originating from local radiative cooling of the surface, is decoupled from non-local flows and can thus be predicted from the local topography. The nocturnal data were stratified by classes of longwave radiation balance, wind speed, and wind direction at 0.1 m agl. The four most abundant classes were tested further for decoupling of wind velocities and directions between 17 and 0.1 m. We further computed the vertical and horizontal temperature perturbations of the fiber-optic array as evaluated for these cases, as well as subject the temperature data to a multiresolution decomposition to investigate the spatial two-point correlation coefficient along the transect. Finally, the cold pool intensity was calculated. The results revealed none of the four most abundant classes followed classical textbook knowledge of locally produced cold-air drainage. Instead, we found that the near-surface flow was strongly forced by two possibly competing non-local flow modes. The first mode caused weak (< 0.4 ms-1) near-surface winds directed perpendicular to the local slope and showed strong vertical decoupling of wind velocities and directions. The vertical and horizontal perturbation of the temperature as well as the cold-pool intensity was high and the two-point correlation coefficient decorrelated fast with increasing distance. In contrast, for the second mode the wind was aligned with the local slope and the wind velocities and directions agreed vertically. However, momentum exchange was much enhanced leading to intense shear-generated mixing and almost vanishing temperature perturbations, higher spatial coherence indicated by slower spatial decorrelations, and a cold-pool intensity of close to zero. In conclusion, the first mode was interpreted as a relatively weak non-local valley-scale cold-air drainage modulating the close to stationary cold-air pool filling the shallow depression the Botanical Gardens are located in. Here, the deeper cold-air drainage causes only weak local movements at the surface as both layers are largely decoupled. The second mode is possibly caused by a recirculation of a stronger valley-scale flow with sufficient synoptic forcing. Our findings challenge the common practice to predict cold-air dynamics solely based on micro-topographic analysis.

Quantification and source identification of the Total Elgin gas leak, UK - North Sea, by aircraft sampling

NASA Astrophysics Data System (ADS)

Lee, J. D.; Bauguitte, S.; Wellpott, A.; Lowry, D.; Fisher, R. E.; Lewis, A. C.; Hopkins, J.; Allen, G.; O'Shea, S.; Lanoiselle, M.; France, J.; Lidster, R.; Punjabi, S.; Manning, A. J.; Ryerson, T. B.; Mobbs, S.; Gallagher, M. W.; Coe, H.; Pyle, J. A.; Nisbet, E. G.

2012-12-01

Aircraft measurement and air sampling have been used to quantify the source and magnitude of the North Sea Total Elgin wellhead platform gas leak in March/April 2012. Isotopic techniques were used to characterise the geological source formation from which the gas came. Initially on 30 March 2012 the leak was in the range 1.6 - 0.7 kg s-1, reducing to less than half that rate by 3 April 2012. Keeling plot analysis of methane in air samples showed that the gas had δ13CCH4 -43‰, implying that the gas source was not the main high-pressure high-temperature Elgin gas field (5.5 km deep, at 190oC) but more probably the overlying Hod Formation. The evidence in the air plume for release of very volatile NMHCs confirmed media reports that the gas leak was on the production platform, above the sea level. This contrasts with the early situation in the BP Deepwater Horizon event, where release was underwater and volatile NMHC species were taken up in the water column. Non-methane hydrocarbons (NMHC) and other volatile organic compounds in the plumes were determined from flask samples by offline analysis. NMHC content was dominated by light alkanes ranging from >20 ppb ethane to <1 ppb benzene and <0.1 ppb higher monoaromatics. The methodology developed in this work is widely applicable to future emissions of environmental concern in circumstances where direct access is difficult or dangerous, and permits unbiased regulatory assessment of potential impact, independent of the emitting party.

Hand-held portable desorption atmospheric pressure chemical ionization ion source for in situ analysis of nitroaromatic explosives.

PubMed

Jjunju, Fred P M; Maher, Simon; Li, Anyin; Syed, Sarfaraz U; Smith, Barry; Heeren, Ron M A; Taylor, Stephen; Cooks, R Graham

2015-10-06

A novel, lightweight (0.6 kg), solvent- and gas-cylinder-free, hand-held ion source based on desorption atmospheric pressure chemical ionization has been developed and deployed for the analysis of nitroaromatic explosives on surfaces in open air, offering portability for in-field analysis. A small, inexpensive, rechargeable lithium polymer battery was used to power the custom-designed circuitry within the device, which generates up to ±5 kV dc voltage to ignite a corona discharge plasma in air for up to 12 h of continuous operation, and allowing positive- and negative-ion mass spectrometry. The generated plasma is pneumatically transported to the surface to be interrogated by ambient air at a rate of 1-3.5 L/min, compressed using a small on-board diaphragm pump. The plasma source allows liquid or solid samples to be examined almost instantaneously without any sample preparation in the open environment. The advantages of low carrier gas and low power consumption (<6 W), as well as zero solvent usage, have aided in developing the field-ready, hand-held device for trigger-based, "near-real-time" sampling/ionization. Individual nitroaromatic explosives (such as 2,4,6-trinitrotoluene) can be easily detected in amounts as low as 5.8 pg with a linear dynamic range of at least 10 (10-100 pg), a relative standard deviation of ca. 7%, and an R(2) value of 0.9986. Direct detection of several nitroaromatic compounds in a complex mixture without prior sample preparation is demonstrated, and their identities are confirmed by tandem mass spectrometry fragmentation patterns.

A survey of recent results in passive sampling of water and air by semipermeable membrane devices

USGS Publications Warehouse

Prest, Harry F.; Huckins, James N.; Petty, Jimmie D.; Herve, Sirpa; Paasivirta, Jaakko; Heinonen, Pertti

1995-01-01

A survey is presented of some recent results for passive sampling of water and air for trace organic contaminants using lipid-filled semipermeable membrane devices (SPMDs). Results of water sampling for trace organochlorine compounds using simultaneously exposed SPMDs and the most universally applied biomonitor (bivalves) are discussed. In general, the total amounts of accumulated analytes available for analysis in bivalves and SPMDs were comparable. However, SPMD controls typically had negligible levels of contamination, which was not always the case for transplanted bivalves, even after prolonged depuration prior to exposure. In surveys of the spatial trends of organochlorines at a series of sites, data from bivalves and SPMDs provided the same picture of contaminant distribution and severity. An exception was ionizable contaminants such as the chlorinated phenolic compounds and their transformation products found in pulp mill effluents. In these cases the two monitoring approaches compliment each other, i.e. what is not found in bivalves appears in SPMDs and vice versa. SPMDs have also been applied in environments where biomonitoring is not feasible. SPMDs have shown their utility in studies of trace levels of polyaromatic hydrocarbons by locating and characterizing point sources. An example is given of their application to the calculation of contaminant half-lives from aqueous SPMD residues, a direct measurement of the persistence of contaminants in an environmental compartment. Similarly, results of air sampling with SPMDs in a relatively pristine coastal location are cited which reveal a tremendous enhancement in p,p′-DDE relative to open ocean values.

40 CFR 61.34 - Air sampling.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 9 2012-07-01 2012-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air...

40 CFR 61.34 - Air sampling.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 9 2013-07-01 2013-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34 Air...

Carter Carburetor Weekly Air Monitoring & Sampling Report - November 30, 2015 – December 6, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - October 26, 2015 – November 1, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - February 15, 2016 – February 21, 2016

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - October 12, 2015 – October 18, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - November 23, 2015 – November 29, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - October 5, 2015 – October 11, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - February 1, 2016 – February 7, 2016

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - September 28, 2015 – October 4, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - November 16, 2015 – November 22, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - November 9, 2015 – November 15, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - October 19, 2015 – October 25, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

Carter Carburetor Weekly Air Monitoring & Sampling Report - November 2, 2015 – November 8, 2015

EPA Pesticide Factsheets

Carter Carburetor Daily Weather Conditions, Dairly Work Activities, Daily Air Monitoring and Samplying Results, Air Monitoring/Samplying Results –Station 2 Linc 126, Air Monitoring/Sampling Results- Sation 3 Linc 123, Air Monitoring/Samplying Results-Stati

New Generation Flask Sampling Technology Final Report

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

Smith, James R.

Scientists are turning their focus to the Arctic, site of one of the strongest climate change signals. A new generation of technologies is required to function within that harsh environment, chart evolution of its trace gases and provide new kinds of information for models of the atmosphere. Our response to the solicitation tracks how global atmospheric monitoring was launched more than a half century ago; namely, acquisition of discrete samples of air by flask and subsequent analysis in the laboratory. AOS is proposing to develop a new generation of flask sampling technology. It will enable the new Arctic programs tomore » begin with objective high density sampling of the atmosphere by UAS. The Phase I program will build the prototype flask technology and show that it can acquire and store mol fractions of CH4 and CO2 and value of δ13C with good fidelity. A CAD model will be produced for the entire platform including a package with 100 flasks and the airframe with auto-pilot, electronic propulsion and ground-to-air communications. A mobile flask analysis station will be prototyped in Phase I and designed to final form in Phase II. It expends very small sample per analysis and will interface directly to the flask package integrated permanently into the UAS fuselage. Commercial Applications and Other Benefits: • The New Generation Flask Sampling Technology able to provide a hundred or more samples of air per UAS mission. • A mobile analysis station expending far less sample than the existing ones and small enough to be stationed at the remote sites of Arctic operations. • A new form of validation for continuous trace gas observations from all platforms including the small UAS. • Further demonstration to potential customers of the AOS capabilities to invent, build, deploy and exploit entire platforms for observations of Earth’s atmosphere and ocean. Key Words: Flask Sampler, Mobile Analysis Station, Trace Gas, CO2, CH4, δC13, UAS, Baseline Airborne Observatory, Arctic, Climate Change. Summary for Members of Congress: The air, land and sea of the Arctic combine to produce a large climate change signal. AOS is proposing to develop unmanned airborne technologies able to begin prompt, objective observations of the signal’s atmospheric component.« less

30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved sampling devices; operation; air... LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate...

Analysis of EPA and DOE WIPP Air Sampling Data

EPA Pesticide Factsheets

During the April 2014 EPA visit to WIPP, EPA co-located four ambient air samplers with existing Department of Energy (DOE) ambient air samplers to independently corroborate DOE's reported air sampling results.

Associations Between Caregiver Health Literacy and Preschool Children’s Secondhand Smoke Exposure

PubMed Central

Welkom, Josie S.; Riekert, Kristin A.; Rand, Cynthia S.

2016-01-01

Objective Examine the associations between caregiver health literacy (HL) and smoking-related outcome expectancies, implementation of home/car smoking bans (H/CSBs), and child secondhand smoke exposure (SHSe). Methods Caregivers of Head Start children residing with a smoker(s) completed measures assessing HL, outcome expectancies, and H/CSB implementation. Biomarkers of child SHSe included home air nicotine monitors and child salivary cotinine. Results Caregivers with lower HL had higher levels of home air nicotine and child salivary cotinine in the full sample and among smokers. After controlling for child age and number of smokers in the home, lower HL was associated with higher endorsement of negative smoking expectancies in the full sample and in smokers. HL was not associated with H/CSB implementation across groups. Conclusions Caregiver HL is associated with child SHSe and is important in shaping smoking-related beliefs. HL is not directly related to adoption of SHSe-reduction behaviors such as H/CSBs. PMID:26330535

Staged fuel and air injection in combustion systems of gas turbines

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

Hughes, Michael John; Berry, Jonathan Dwight

A gas turbine that includes a working fluid flowpath extending aftward from a forward injector in a combustor. The combustor may include an inner radial wall, an outer radial wall, and, therebetween, a flow annulus. A staged injector may intersect the flow annulus so to attain an injection point within the working fluid flowpath by which aftward and forward annulus sections are defined. Air directing structure may include an aftward intake section that corresponds to the aftward annulus section and a forward intake section that corresponds to the forward annulus section. The air directing structure may be configured to: directmore » air entering through the aftward intake section through the aftward annulus section in a forward direction to the staged injector; and direct air entering through the forward intake section through the forward annulus section in a forward direction to the forward injector.« less

Staged fuel and air injection in combustion systems of gas turbines

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

Hughes, Michael John; Berry, Jonathan Dwight

A gas turbine that includes a working fluid flowpath extending aftward from a forward injector in a combustor. The combustor may include an inner radial wall, an outer radial wall, and, therebetween, a flow annulus. A staged injector may intersect the flow annulus so to attain an injection point within the working fluid flowpath by which aftward and forward annulus sections are defined. Air directing structure may include an aftward intake section that corresponds to the aftward annulus section and a forward intake section that corresponds to the forward annulus section. The air directing structure may be configured to: directmore » air entering through the aftward intake section through the aftward annulus section in a forward direction to the staged injector; and direct air entering through the forward intake section through the forward annulus section in an aftward direction to the staged injector.« less

Air and surface contamination patterns of meticillin-resistant Staphylococcus aureus on eight acute hospital wards.

PubMed

Creamer, E; Shore, A C; Deasy, E C; Galvin, S; Dolan, A; Walley, N; McHugh, S; Fitzgerald-Hughes, D; Sullivan, D J; Cunney, R; Coleman, D C; Humphreys, H

2014-03-01

Meticillin-resistant Staphylococcus aureus (MRSA) can be recovered from hospital air and from environmental surfaces. This poses a potential risk of transmission to patients. To investigate associations between MRSA isolates recovered from air and environmental surfaces with those from patients when undertaking extensive patient and environmental sampling. This was a prospective observational study of patients and their environment in eight wards of a 700-bed tertiary care hospital during 2010 and 2011. Sampling of patients, air and surfaces was carried out on all ward bays, with more extended environmental sampling in ward high-dependency bays and at particular times of the day. The genetic relatedness of isolates was determined by DNA microarray profiling and spa typing. MRSA was recovered from 30/706 (4.3%) patients and from 19/132 (14.4%) air samples. On 9/132 (6.8%) occasions both patient and air samples yielded MRSA. In 32 high-dependency bays, MRSA was recovered from 12/161 (7.4%) patients, 8/32 (25%) air samples, and 21/644 (3.3%) environmental surface samples. On 10/132 (7.6%) occasions, MRSA was isolated from air in the absence of MRSA-positive patients. Patient demographic data combined with spa typing and DNA microarray profiling revealed four likely transmission clusters, where patient and environmental isolates were deemed to be very closely related. Air sampling yielded MRSA on frequent occasions, especially in high-dependency bays. Environmental and air sampling combined with patient demographic data, spa typing and DNA microarray profiling indicated the presence of clusters that were not otherwise apparent. Copyright © 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.

Gas turbine topping combustor

DOEpatents

Beer, Janos; Dowdy, Thomas E.; Bachovchin, Dennis M.

1997-01-01

A combustor for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone.

Microbial air quality in mass transport buses and work-related illness among bus drivers of Bangkok Mass Transit Authority.

PubMed

Luksamijarulkul, Pipat; Sundhiyodhin, Viboonsri; Luksamijarulkul, Soavalug; Kaewboonchoo, Orawan

2004-06-01

The air quality in mass transport buses, especially air-conditioned buses may affect bus drivers who work full time. Bus numbers 16, 63, 67 and 166 of the Seventh Bus Zone of Bangkok Mass Transit Authority were randomly selected to investigate for microbial air quality. Nine air-conditioned buses and 2-4 open-air buses for each number of the bus (36 air-conditioned buses and 12 open-air buses) were included. Five points of in-bus air samples in each studied bus were collected by using the Millipore A ir Tester Totally, 180 and 60 air samples collected from air-conditioned buses and open-air buses were cultured for bacterial and fungal counts. The bus drivers who drove the studied buses were interviewed towards histories of work-related illness while working. The results revealed that the mean +/- SD of bacterial counts in the studied open-air buses ranged from 358.50 +/- 146.66 CFU/m3 to 506 +/- 137.62 CFU/m3; bus number 16 had the highest level. As well as the mean +/- SD of fungal counts which ranged from 93.33 +/- 44.83 CFU/m3 to 302 +/- 294.65 CFU/m3; bus number 166 had the highest level. Whereas, the mean +/- SD of bacterial counts in the studied air-conditioned buses ranged from 115.24 +/- 136.01 CFU/m3 to 244.69 +/- 234.85 CFU/m3; bus numbers 16 and 67 had the highest level. As well as the mean +/- SD of fungal counts which rangedfrom 18.84 +/- 39.42 CFU/m3 to 96.13 +/- 234.76 CFU/m3; bus number 166 had the highest level. When 180 and 60 studied air samples were analyzed in detail, it was found that 33.33% of the air samples from open-air buses and 6.11% of air samples from air-conditioned buses had a high level of bacterial counts (> 500 CFU/m3) while 6.67% of air samples from open-air buses and 2.78% of air samples from air-conditioned buses had a high level of fungal counts (> 500 CFU/m3). Data from the history of work-related illnesses among the studied bus drivers showed that 91.67% of open-air bus drivers and 57.28% of air-conditioned bus drivers had symptoms of work-related illnesses, p = 0.0185.

Simultaneous determination of ozone and carbonyls using trans-1,2-bis(4-pyridyl)ethylene as an ozone scrubber for 2,4-dinitrophenylhydrazine-impregnated silica cartridge.

PubMed

Uchiyama, Shigehisa; Otsubo, Yasufumi

2008-05-01

A new method for the simultaneous determination of ozone and carbonyls in air using a two-bed cartridge system has been developed. Each bed consists of reagent-impregnated silica particles. The first contains trans-1,2-bis-(4-pyridyl) ethylene (BPE) while the second contains 2,4-dinitrophenylhydrazine (DNPH). Air samples are drawn through the cartridge first through the BPE and then through the DNPH. Ozone in the air sample is trapped in the first bed by the BPE-coated silica particles and produce pyridine-4-aldehyde. Airborne carbonyls pass unimpeded thorough the BPE and are trapped in the second bed by the DNPH-coated silica particles. They produce carbonyl 2,4-DNPhydrazones. DNPH and carbonyl 2,4-DNPhydrazones are not influenced by ozone because of effective trapping by the BPE. Extraction is performed in the direction reverse to air sampling. When solvent is eluted through the BEP/DNPH cartridge, excess DNPH is washed into the BPE bed where it reacted with pyridine-4-aldehyde and forms the corresponding hydrazone derivative. All of the hydrazones derived from airborne carbonyls and pyridine-4-aldehyde (derived from ozone) are completely separated and measured using high-performance liquid chromatography. An Ascentis RP-Amide column is used, and the mobile phase is 40% aqueous acetonitrile containing 2 mmol/L ammonium acetate. The use of a BPE/DNPH cartridge has made possible the simultaneous determination of ozone and carbonyls. A separate ozone scrubber is not necessary with the BPE/DNPH cartridge because the BPE portion of the sampler serves this function.

Ambient air quality status in Raniganj-Asansol area, India.

PubMed

Reddy, G S; Ruj, Biswajit

2003-12-01

This investigation presents the assessment of ambient air quality with respect to suspended particulate matter (SPM), sulphur dioxide (SO2) and oxides of nitrogen (NOx) at four sites (RGC, SRS, BBC and BCC) in the Raniganj-Asansol area in West Bengal, India. Ambient air was monitored with a sampling frequency of twenty four hours (3 x 8 hours) at each site on every alternate day (3 days a week) covering a period of one year. A total of 429 samples were collected from RGC, 429 from SRS and 435 each from the BBC and BCC sites. Meteorological parameters such as temperature, relative humidity, wind-speed and wind-direction were also recorded simultaneously during the sampling period. Monthly and seasonal variation of these pollutants have been observed and recorded. The annual average and range values have also been calculated. Results of the investigation indicates that the 95th percentile values of SPM levels exceed the limits (200 microg m(-3)) at RGC, SRS and BBC sites and is within the limit of 500 microg m(-3) at the BCC sites. The 95th percentile values of SO2 levels did not exceed the reference level at any of the monitoring stations. The 95th percentile values of NOx are found to be exceeding the limit (80 microg m(-3)) at RGC, SRS and BBC sites but is within the prescribed limit of 120 microg m(-3) at the BCC site. Further, it has been observed that the concentrations of the pollutants are high in winter in comparison to the summer or the monsoon seasons. Results of the investigation indicates that industrial activities, indiscriminate open air burning of coal by the local inhabitants for cooking as well as coking purposes, vehicular traffic, etc. are responsible for the high concentration of pollutants in this area.

SEM/EDS Characterization of Ambient PM during Agricultural Burns

NASA Astrophysics Data System (ADS)

Wagner, J.; Wall, S.

2010-12-01

Ambient particulate matter (PM) samples were collected with UNC passive samplers during agricultural burns in Imperial Valley, California. Four Bermuda grass field burn events were sampled at 3-8 locations surrounding each burn. Sampling began at the start of each burn (30-60 min) and continued for 24-120 hours. During 3 of the 4 burn events, winds were calm and plumes were observed to travel straight up to the inversion layer. In one event, winds created a ground-level plume that enveloped two UNC samplers mounted on telephone poles very close to the field (0.2-0.3 miles away). Computer-controlled scanning electron microscopy / energy-dispersive x-ray spectroscopy (CCSEM/EDS) was used to measure particle sizes and elemental composition, from which mass concentrations and size distributions were calculated. The median PM2.5 and PM10 levels measured in this study were 3.4 and 20 ug/m3, respectively. To determine quantitative accuracy, UNC sampler PM2.5 results (PM< 2.5 um) were compared to PM2.5 results from four co-located, continuous-reading beta-attenuation monitors (EBAMs). The median agreement (EBAM - UNC) was 3.8 ug/m3. Manual SEM/EDS detected various distinctive species in these samples, including sea salt, spores, plant fragments, and large soot agglomerates. During the ‘plume event’, 24-hour PM2.5 exposures downwind were up to 17 times higher than that measured upwind. Numerous submicron combustion particles with carbon and oxygen only were directly observed by manual SEM/EDS in the two plume-impacted samples, along with larger ash particles enriched in potassium, sulfur, chlorine, calcium, sodium, and phosphorus. CCSEM/EDS data from this event was grouped into 5 particle classes to generate size-fraction-specific pie charts. Burn-related particle types contributed 95% of the PM2.5 in the location directly impacted by the ground-level plume, compared to only 12% in the upwind location. A sample of Imperial County Bermuda grass analyzed in bulk and partially-burned states was found to contain similar inorganic elements as the air samples impacted by the burn plume, as well as mold spores found at trace levels in various air samples.

Use of direct versus indirect preparation data for assessing risk associated with airborne exposures at asbestos-contaminated sites.

PubMed

Goldade, Mary Patricia; O'Brien, Wendy Pott

2014-01-01

At asbestos-contaminated sites, exposure assessment requires measurement of airborne asbestos concentrations; however, the choice of preparation steps employed in the analysis has been debated vigorously among members of the asbestos exposure and risk assessment communities for many years. This study finds that the choice of preparation technique used in estimating airborne amphibole asbestos exposures for risk assessment is generally not a significant source of uncertainty. Conventionally, the indirect preparation method has been less preferred by some because it is purported to result in false elevations in airborne asbestos concentrations, when compared to direct analysis of air filters. However, airborne asbestos sampling in non-occupational settings is challenging because non-asbestos particles can interfere with the asbestos measurements, sometimes necessitating analysis via indirect preparation. To evaluate whether exposure concentrations derived from direct versus indirect preparation techniques differed significantly, paired measurements of airborne Libby-type amphibole, prepared using both techniques, were compared. For the evaluation, 31 paired direct and indirect preparations originating from the same air filters were analyzed for Libby-type amphibole using transmission electron microscopy. On average, the total Libby-type amphibole airborne exposure concentration was 3.3 times higher for indirect preparation analysis than for its paired direct preparation analysis (standard deviation = 4.1), a difference which is not statistically significant (p = 0.12, two-tailed, Wilcoxon signed rank test). The results suggest that the magnitude of the difference may be larger for shorter particles. Overall, neither preparation technique (direct or indirect) preferentially generates more precise and unbiased data for airborne Libby-type amphibole concentration estimates. The indirect preparation method is reasonable for estimating Libby-type amphibole exposure and may be necessary given the challenges of sampling in environmental settings. Relative to the larger context of uncertainties inherent in the risk assessment process, uncertainties associated with the use of airborne Libby-type amphibole exposure measurements derived from indirect preparation analysis are low. Use of exposure measurements generated by either direct or indirect preparation analyses is reasonable to estimate Libby-type Amphibole exposures in a risk assessment.

Rethink potential risks of toxic emissions from natural gas and oil mining.

PubMed

Meng, Qingmin

2018-09-01

Studies have showed the increasing environmental and public health risks of toxic emissions from natural gas and oil mining, which have become even worse as fracking is becoming a dominant approach in current natural gas extraction. However, governments and communities often overlook the serious air pollutants from oil and gas mining, which are often quantified lower than the significant levels of adverse health effects. Therefore, we are facing a challenging dilemma: how could we clearly understand the potential risks of air toxics from natural gas and oil mining. This short study aims at the design and application of simple and robust methods to enhance and improve current understanding of the becoming worse toxic air emissions from natural gas and oil mining as fracking is becoming the major approach. Two simple ratios, the min-to-national-average and the max-to-national-average, are designed and applied to each type of air pollutants in a natural gas and oil mining region. The two ratios directly indicate how significantly high a type of air pollutant could be due to natural gas and oil mining by comparing it to the national average records, although it may not reach the significant risks of adverse health effects according to current risk screening methods. The min-to-national-average and the max-to-national-average ratios can be used as a direct and powerful method to describe the significance of air pollution by comparing it to the national average. The two ratios are easy to use for governments, stakeholders, and the public to pay enough attention on the air pollutants from natural gas and oil mining. The two ratios can also be thematically mapped at sampled sites for spatial monitoring, but spatial mitigation and analysis of environmental and health risks need other measurements of environmental and demographic characteristics across a natural gas and oil mining area. Copyright © 2018 Elsevier Ltd. All rights reserved.

A new technique for preliminary estimates of TRU activity on air sample filters and radiological smears.

PubMed

Hayes, Robert

2004-10-01

In most nuclear facilities, fixed air samplers and sometimes portable air samplers are used where some probability of a release exists but is not expected, and so the added expense and effort of using a continuous air monitor is not deemed justified. When a release is suspected, naturally occurring radioactive material buildup on the filter typically prevents any quantitative measurements within the first day or so. Likewise, outdoor air measurements suffer from the same limitations (such as those taken during the Los Alamos fires) and so any rapid quantifiable measurements of fixed air sampler/portable air sampler filters which are technically defendable (even though conservative) are of use. The technique presented here is only intended for use in routine health physics survey applications and does not presently appear to be appropriate for sub pico Curie activity determinations. This study evaluates the utility of using a portable continuous air monitor as an alpha spectrometer to make transuranic activity determinations of samples using both the built in algorithm for air monitoring and a simple region of interest analysis. All samples evaluated were from air sample filters taken using a portable air sampler. Samples were taken over many months to quantify effects from natural variation in radon progeny activity distributions.

Activated carbon derived from chitosan as air cathode catalyst for high performance in microbial fuel cells

NASA Astrophysics Data System (ADS)

Liu, Yi; Zhao, Yong; Li, Kexun; Wang, Zhong; Tian, Pei; Liu, Di; Yang, Tingting; Wang, Junjie

2018-02-01

Chitosan with rich of nitrogen is used as carbon precursor to synthesis activated carbon through directly heating method in this study. The obtained carbon is activated by different amount of KOH at different temperatures, and then prepared as air cathodes for microbial fuel cells. Carbon sample treated with double amount of KOH at 850 °C exhibits maximum power density (1435 ± 46 mW m-2), 1.01 times improved, which ascribes to the highest total surface area, moderate micropore and mesoporous structure and the introduction of nitrogen. The electrochemical impedance spectroscopy and powder resistivity state that carbon treated with double amount of KOH at 850 °C possesses lower resistance. The other electrochemical measurements demonstrate that the best kinetic activity make the above treated sample to show the best oxygen reduction reaction activity. Besides, the degree of graphitization of samples increases with the activated temperature increasing, which is tested by Raman. According to elemental analysis and X-ray photoelectron spectroscopy, all chitosan samples are nitrogen-doped carbon, and high content nitrogen (pyridinic-N) improves the electrochemical activity of carbon treated with KOH at 850 °C. Thus, carbon materials derived from chitosan would be an optimized catalyst for oxygen reduction reaction in microbial fuel cell.

Two stage indirect evaporative cooling system

DOEpatents

Bourne, Richard C.; Lee, Brian E.; Callaway, Duncan

2005-08-23

A two stage indirect evaporative cooler that moves air from a blower mounted above the unit, vertically downward into dry air passages in an indirect stage and turns the air flow horizontally before leaving the indirect stage. After leaving the dry passages, a major air portion travels into the direct stage and the remainder of the air is induced by a pressure drop in the direct stage to turn 180.degree. and returns horizontally through wet passages in the indirect stage and out of the unit as exhaust air.

Quantifying Fugitive Methane Emissions from Natural Gas Production with Mobile Technology

NASA Astrophysics Data System (ADS)

Tsai, T.; Rella, C.; Crosson, E.

2013-12-01

Quantification of fugitive methane (CH4) emissions to determine the environmental impact of natural gas production is challenging with current methods. We present a new mobile method known as the Plume Scanner that can quickly quantify CH4 emissions of point sources. The Plume Scanner is a direct measurement technique which utilizes a mobile Picarro cavity ring-down spectrometer and a gas sampling system based on AirCore technology [1]. As the Plume Scanner vehicle drives through the plume, the air is simultaneously sampled at four different heights, and therefore, the spatial CH4 distribution can be captured (Fig. 1). The flux of the plume is then determined by multiplying the spatial CH4 distribution data with the anemometer measurements. In this way, fugitive emission rates of highly localized sources such as natural gas production pads can be made quickly (~7 min). Verification with controlled CH4 releases demonstrate that under stable atmospheric conditions (Pasquill stability class is C or greater), the Plume Scanner measurements have an error of 2% and a repeatability of 15% [2]. Under unstable atmospheric conditions (Class A or B), the error is 6%, and the repeatability increases to 70% due to the variability of wind conditions. Over two weeks, 275 facilities in the Barnett Shale were surveyed from public roads by sampling the air for elevations in CH4 concentration, and 77% were found leaking. Emissions from 52 sites have been quantified with the Plume Scanner (Fig. 2), and the total emission is 4,900 liters per min (lpm) or 39,000 metric tons/yr CO2e. 1. Karion, A., C. Sweeney, P. Tans, and T. Newberger (2010), AirCore: An innovative atmospheric sampling system, J. Atmos. Oceanic Tech, 27, 1839-1853. 2. F. Pasquill (1961), The estimation of the dispersion of wind borne material, Meterol. Mag., 90(1063), 33-49 Figure 1. Plume Scanner Cartoon Figure 2. Distribution of methane fugitive emissions with error bars associated with the Pasquill stability classes drawn for reference.

Historical Carbon Dioxide Record from the Vostok Ice Core (417,160 - 2,342 years BP)

DOE Data Explorer

Barnola, J. M. [CNRS, Saint Martin d'Heres Cedex, France; Raynaud, D. [CNRS, Saint Martin d'Heres Cedex, France; Lorius, C. [CNRS, Saint Martin d'Heres Cedex, France; Barkov, N. I.

2003-01-01

In January 1998, the collaborative ice-drilling project between Russia, the United States, and France at the Russian Vostok station in East Antarctica yielded the deepest ice core ever recovered, reaching a depth of 3,623 m (Petit et al. 1997, 1999). Ice cores are unique with their entrapped air inclusions enabling direct records of past changes in atmospheric trace-gas composition. Preliminary data indicate the Vostok ice-core record extends through four climate cycles, with ice slightly older than 400 kyr (Petit et al. 1997, 1999). Because air bubbles do not close at the surface of the ice sheet but only near the firn-ice transition (that is, at ~90 m below the surface at Vostok), the air extracted from the ice is younger than the surrounding ice (Barnola et al. 1991). Using semiempirical models of densification applied to past Vostok climate conditions, Barnola et al. (1991) reported that the age difference between air and ice may be ~6000 years during the coldest periods instead of ~4000 years, as previously assumed. Ice samples were cut with a bandsaw in a cold room (at about -15°C) as close as possible to the center of the core in order to avoid surface contamination (Barnola et al. 1983). Gas extraction and measurements were performed with the "Grenoble analytical setup," which involved crushing the ice sample (~40 g) under vacuum in a stainless steel container without melting it, expanding the gas released during the crushing in a pre-evacuated sampling loop, and analyzing the CO2 concentrations by gas chromatography (Barnola et al. 1983). The analytical system, except for the stainless steel container in which the ice was crushed, was calibrated for each ice sample measurement with a standard mixture of CO2 in nitrogen and oxygen. For further details on the experimental procedures and the dating of the successive ice layers at Vostok, see Barnola et al. (1987, 1991), Lorius et al. (1985), and Petit et al. (1999).

Measurement of radioactivity concentration in blood by using newly developed ToT LuAG-APD based small animal PET tomograph.

PubMed

Malik, Azhar H; Shimazoe, Kenji; Takahashi, Hiroyuki

2013-01-01

In order to obtain plasma time activity curve (PTAC), input function for almost all quantitative PET studies, patient blood is sampled manually from the artery or vein which has various drawbacks. Recently a novel compact Time over Threshold (ToT) based Pr:LuAG-APD animal PET tomograph is developed in our laboratory which has 10% energy resolution, 4.2 ns time resolution and 1.76 mm spatial resolution. The measured value of spatial resolution shows much promise for imaging the blood vascular, i.e; artery of diameter 2.3-2.4mm, and hence, to measure PTAC for quantitative PET studies. To find the measurement time required to obtain reasonable counts for image reconstruction, the most important parameter is the sensitivity of the system. Usually small animal PET systems are characterized by using a point source in air. We used Electron Gamma Shower 5 (EGS5) code to simulate a point source at different positions inside the sensitive volume of tomograph and the axial and radial variations in the sensitivity are studied in air and phantom equivalent water cylinder. An average sensitivity difference of 34% in axial direction and 24.6% in radial direction is observed when point source is displaced inside water cylinder instead of air.

Fatigue crack growth rates in a pressure vessel steel under various conditions of loading and the environment

NASA Astrophysics Data System (ADS)

Hicks, P. D.; Robinson, F. P. A.

1986-10-01

Corrosion fatigue (CF) tests have been carried out on SA508 Cl 3 pressure vessel steel, in simulated P.W.R. environments. The test variables investigated included air and P.W.R. water environments, frequency variation over the range 1 Hz to 10 Hz, transverse and longitudinal crack growth directions, temperatures of 20 °C and 50 °C, and R-ratios of 0.2 and 0.7. It was found that decreasing the test frequency increased fatigue crack growth rates (FCGR) in P.W.R. environments, P.W.R. environment testing gave enhanced crack growth (vs air tests), FCGRs were greater for cracks growing in the longitudinal direction, slight increases in temperature gave noticeable accelerations in FCGR, and several air tests gave FCGR greater than those predicted by the existing ASME codes. Fractographic evidence indicates that FCGRs were accelerated by a hydrogen embrittlement mechanism. The presence of elongated MnS inclusions aided both mechanical fatigue and hydrogen embrittlement processes, thus producing synergistically fast FCGRs. Both anodic dissolution and hydrogen embrittlement mechanisms have been proposed for the environmental enhancement of crack growth rates. Electrochemical potential measurements and potentiostatic tests have shown that sample isolation of the test specimens from the clevises in the apparatus is not essential during low temperature corrosion fatigue testing.

[Legionella spp. contamination in indoor air: preliminary results of an Italian multicenter study].

PubMed

Montagna, Maria Teresa; De Giglio, Osvalda; Napoli, Christian; Cannova, Lucia; Cristina, Maria Luisa; Deriu, Maria Grazia; Delia, Santi Antonino; Giuliano, Ada; Guida, Marco; Laganà, Pasqualina; Liguori, Giorgio; Mura, Ida; Pennino, Francesca; Rossini, Angelo; Tardivo, Stefano; Torre, Ida; Torregrossa, Maria Valeria; Villafrate, Maria Rosaria; Albertini, Roberto; Pasquarella, Cesira

2014-01-01

To propose a standardized protocol for the evaluation of Legionella contamination in air. A bathroom having a Legionella contamination in water >1,000 cfu/l was selected in 10 different healthcare facilities. Air contamination was assessed by active (Surface Air System, SAS) and passive (Index of Microbial Air, IMA) sampling for 8 hours, about 1 m away from the floor and 50 cm from the tap water. Two hundred liters of air were sampled by SAS every 12 min, after flushing water for 2 min. The IMA value was calculated as the mean value of colony forming units/16 plates exposed during sampling (2 plates/hour). Water contamination was evaluated at T0, after 4 and 8 hours, according to the standard methods. Air contamination by Legionella was found in three healthcare facilities (one with active and two with passive sampling), showing a concomitant tap water contamination (median=40,000; range 1,100-43,000 cfu/l). The remaining seven hospitals isolated Legionella spp. exclusively from water samples (median=8,000; range 1,200-70,000 cfu/l). Our data suggest that environmental Legionella contamination cannot be assessed only through the air sampling, even in the presence of an important water contamination.

Effects of process parameters on solid self-microemulsifying particles in a laboratory scale fluid bed.

PubMed

Mukherjee, Tusharmouli; Plakogiannis, Fotios M

2012-01-01

The purpose of this study was to select the critical process parameters of the fluid bed processes impacting the quality attribute of a solid self-microemulsifying (SME) system of albendazole (ABZ). A fractional factorial design (2(4-1)) with four parameters (spray rate, inlet air temperature, inlet air flow, and atomization air pressure) was created by MINITAB software. Batches were manufactured in a laboratory top-spray fluid bed at 625-g scale. Loss on drying (LOD) samples were taken throughout each batch to build the entire moisture profiles. All dried granulation were sieved using mesh 20 and analyzed for particle size distribution (PSD), morphology, density, and flow. It was found that as spray rate increased, sauter-mean diameter (D(s)) also increased. The effect of inlet air temperature on the peak moisture which is directly related to the mean particle size was found to be significant. There were two-way interactions between studied process parameters. The main effects of inlet air flow rate and atomization air pressure could not be found as the data were inconclusive. The partial least square (PLS) regression model was found significant (P < 0.01) and predictive for optimization. This study established a design space for the parameters for solid SME manufacturing process.

Spring Melt and the Redistribution of Organochlorine Pesticides in the Sea-Ice Environment: A Comparative Study between Arctic and Antarctic Regions.

PubMed

Bigot, Marie; Hawker, Darryl W; Cropp, Roger; Muir, Derek Cg; Jensen, Bjarne; Bossi, Rossana; Bengtson Nash, Susan M

2017-08-15

Complementary sampling of air, snow, sea-ice, and seawater for a range of organochlorine pesticides (OCPs) was undertaken through the early stages of respective spring sea-ice melting at coastal sites in northeast Greenland and eastern Antarctica to investigate OCP concentrations and redistribution during this time. Mean concentrations in seawater, sea-ice and snow were generally greater at the Arctic site. For example, α-HCH was found to have the largest concentrations of all analytes in Arctic seawater and sea-ice meltwater samples (224-253 and 34.7-48.2 pg·L -1 respectively compared to 1.0-1.3 and <0.63 pg·L -1 respectively for Antarctic samples). Differences in atmospheric samples were generally not as pronounced however. Findings suggest that sea-ice OCP burdens originate from both snow and seawater. The distribution profile between seawater and sea-ice showed a compound-dependency for Arctic samples not evident with those from the Antarctic, possibly due to full submersion of sea-ice at the former. Seasonal sea-ice melt processes may alter the exchange rates of selected OCPs between air and seawater, but are not expected to reverse their direction, which fugacity modeling indicates is volatilisation in the Arctic and net deposition in the Antarctic. These predictions are consistent with the limited current observations.

Rotor and stator assembly configured as an aspirating face seal

NASA Technical Reports Server (NTRS)

Turnquist, Norman Arnold (Inventor); Bagepalli, Bharat Sampathkumaran (Inventor); Reluzco, George (Inventor); Tseng, Wu-Yang (Inventor)

1999-01-01

A rotor and stator assembly having a rotor and a stator with opposing surfaces defining an air bearing and an air dam of an aspirating face seal. In a first embodiment, the air bearing and the air dam are axially offset. In a second embodiment, the rotor has an axially extending protuberance located radially between the air bearing and the air dam. The axial offset and the protuberance each act to divert the air flow (e.g., compressed gas or combustion gases in a gas turbine or steam in a steam turbine) in a direction transverse to the air flow direction through the air bearing and the air dam, thus isolating the air flows from the air bearing and the air dam which improves seal performance.

Technical note: Air compared to nitrogen as nebulizing and drying gases for electrospray ionization mass spectrometry.

PubMed

Mielczarek, P; Silberring, J; Smoluch, M

In the present study we tested the application of compressed air instead of pure nitrogen as the nebulizing and drying gas, and its influence on the quality of electrospray ionization (ESI) mass spectra. The intensities of the signals corresponding to protonated molecules were significantly (twice) higher when air was used. Inspection of signal-to-noise (S/N) ratios revealed that, in both cases, sensitivity was comparable. A higher ion abundance after the application of compressed air was followed by a higher background. Another potential risk of using air in the ESI source is the possibility for sample oxidation due to the presence of oxygen. To test this, we selected five easily oxidizing compounds to verify their susceptibility to oxidation. In particular, the presence of methionine was of interest. For all the compounds studied, no oxidation was observed. Amodiaquine oxidizes spontaneously in water solutions and its oxidized form can be detected a few hours after preparation. Direct comparison of the spectra where nitrogen was used with the corresponding spectra obtained when air was applied did not show significant differences. The only distinction was slightly different patterns of adducts when air was used. The difference concerns acetonitrile, which forms higher signals when air is the nebulizing gas. It is also important that the replacement of nitrogen with air does not affect quantitative data. The prepared calibration curves also visualize an intensity twice as high (independent of concentration within tested range) of the signal where air was applied. We have used our system continuously for three months with air as the nebulizing and drying gas and have not noticed any unexpected signal deterioration caused by additional source contamination from the air. Moreover, compressed air is much cheaper and easily available using oil-free compressors or pumps.

Sorbent-based sampling methods for volatile and semi-volatile organic compounds in air Part 1: Sorbent-based air monitoring options.

PubMed

Woolfenden, Elizabeth

2010-04-16

Sorbent tubes/traps are widely used in combination with gas chromatographic (GC) analytical methods to monitor the vapour-phase fraction of organic compounds in air. Target compounds range in volatility from acetylene and freons to phthalates and PCBs and include apolar, polar and reactive species. Airborne vapour concentrations will vary depending on the nature of the location, nearby pollution sources, weather conditions, etc. Levels can range from low percent concentrations in stack and vent emissions to low part per trillion (ppt) levels in ultra-clean outdoor locations. Hundreds, even thousands of different compounds may be present in any given atmosphere. GC is commonly used in combination with mass spectrometry (MS) detection especially for environmental monitoring or for screening uncharacterised workplace atmospheres. Given the complexity and variability of organic vapours in air, no one sampling approach suits every monitoring scenario. A variety of different sampling strategies and sorbent media have been developed to address specific applications. Key sorbent-based examples include: active (pumped) sampling onto tubes packed with one or more sorbents held at ambient temperature; diffusive (passive) sampling onto sorbent tubes/cartridges; on-line sampling of air/gas streams into cooled sorbent traps; and transfer of air samples from containers (canisters, Tedlar) bags, etc.) into cooled sorbent focusing traps. Whichever sampling approach is selected, subsequent analysis almost always involves either solvent extraction or thermal desorption (TD) prior to GC(/MS) analysis. The overall performance of the air monitoring method will depend heavily on appropriate selection of key sampling and analytical parameters. This comprehensive review of air monitoring using sorbent tubes/traps is divided into 2 parts. (1) Sorbent-based air sampling option. (2) Sorbent selection and other aspects of optimizing sorbent-based air monitoring methods. The paper presents current state-of-the-art and recent developments in relevant areas such as sorbent research, sampler design, enhanced approaches to analytical quality assurance and on-tube derivatisation. Copyright 2009 Elsevier B.V. All rights reserved.

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.

The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

PubMed

Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

2011-09-01

Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration.

Assessment of Air Quality in the Shuttle and International Space Station (ISS) Based on Samples Returned by STS-104 at the Conclusion of 7A

NASA Technical Reports Server (NTRS)

James, John T.

2001-01-01

The toxicological assessment of air samples returned at the end of the STS-l04 (7 A) flight to the ISS is reported. ISS air samples were taken in June and July 2001 from the Service Module, FGB, and U.S. Laboratory using grab sample canisters (GSCs) and/or formaldehyde badges. Preflight and end-of-mission samples were obtained from Atlantis using GSCs. Solid sorbent air sampler (SSAS) samples were obtained from the ISS in April, June, and July. Analytical methods have not changed from earlier reports, and all quality control measures were met.

Radial lean direct injection burner

DOEpatents

Khan, Abdul Rafey; Kraemer, Gilbert Otto; Stevenson, Christian Xavier

2012-09-04

A burner for use in a gas turbine engine includes a burner tube having an inlet end and an outlet end; a plurality of air passages extending axially in the burner tube configured to convey air flows from the inlet end to the outlet end; a plurality of fuel passages extending axially along the burner tube and spaced around the plurality of air passage configured to convey fuel from the inlet end to the outlet end; and a radial air swirler provided at the outlet end configured to direct the air flows radially toward the outlet end and impart swirl to the air flows. The radial air swirler includes a plurality of vanes to direct and swirl the air flows and an end plate. The end plate includes a plurality of fuel injection holes to inject the fuel radially into the swirling air flows. A method of mixing air and fuel in a burner of a gas turbine is also provided. The burner includes a burner tube including an inlet end, an outlet end, a plurality of axial air passages, and a plurality of axial fuel passages. The method includes introducing an air flow into the air passages at the inlet end; introducing a fuel into fuel passages; swirling the air flow at the outlet end; and radially injecting the fuel into the swirling air flow.

Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air

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

Lee, Jo Jo; Ghosh, Tushar K.; Loyalka, Sudarshan K.

In this paper, the oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deepermore » oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Finally, kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.« less

Comparison of NBG-18, NBG-17, IG-110 and IG-11 oxidation kinetics in air

DOE PAGES

Lee, Jo Jo; Ghosh, Tushar K.; Loyalka, Sudarshan K.

2017-12-14

In this paper, the oxidation rates of several nuclear-grade graphites, NBG-18, NBG-17, IG-110 and IG-11, were measured in air using thermogravimetry. Kinetic parameters and oxidation behavior for each grade were compared by coke type, filler grain size and microstructure. The thickness of the oxidized layer for each grade was determined by layer peeling and direct density measurements. The results for NBG-17 and IG-11 were compared with those available in the literature and our recently reported results for NBG-18 and IG-110 oxidation in air. The finer-grained graphites IG-110 and IG-11 were more oxidized than medium-grained NBG-18 and NBG-17 because of deepermore » oxidant penetration, higher porosity and higher probability of available active sites. Variation in experimental conditions also had a marked effect on the reported kinetic parameters by several studies. Finally, kinetic parameters such as activation energy and transition temperature were sensitive to air flow rates as well as sample size and geometry.« less

Passive Sampling for Indoor and Outdoor Exposures to Chlorpyrifos, Azinphos-Methyl, and Oxygen Analogs in a Rural Agricultural Community.

PubMed

Gibbs, Jenna L; Yost, Michael G; Negrete, Maria; Fenske, Richard A

2017-03-01

Recent studies have highlighted the increased potency of oxygen analogs of organophosphorus pesticides. These pesticides and oxygen analogs have previously been identified in the atmosphere following spray applications in the states of California and Washington. We used two passive sampling methods to measure levels of the ollowing organophosphorus pesticides: chlorpyrifos, azinphos-methyl, and their oxygen analogs at 14 farmworker and 9 non-farmworker households in an agricultural region of central Washington State in 2011. The passive methods included polyurethane foam passive air samplers deployed outdoors and indoors and polypropylene deposition plates deployed indoors. We collected cumulative monthly samples during the pesticide application seasons and during the winter season as a control. Monthly outdoor air concentrations ranged from 9.2 to 199 ng/m 3 for chlorpyrifos, 0.03 to 20 ng/m 3 for chlorpyrifos-oxon, < LOD (limit of detection) to 7.3 ng/m 3 for azinphos-methyl, and < LOD to 0.8 ng/m 3 for azinphos-methyl-oxon. Samples from proximal households (≤ 250 m) had significantly higher outdoor air concentrations of chlorpyrifos, chlorpyrifos-oxon, and azinphos-methyl than did samples from nonproximal households ( p ≤ 0.02). Overall, indoor air concentrations were lower than outdoors. For example, all outdoor air samples for chlorpyrifos and 97% of samples for azinphos-methyl were > LOD. Indoors, only 78% of air samples for chlorpyrifos and 35% of samples for azinphos-methyl were > LOD. Samples from farmworker households had higher indoor air concentrations of both pesticides than did samples from non-farmworker households. Mean indoor and outdoor air concentration ratios for chlorpyrifos and azinphos-methyl were 0.17 and 0.44, respectively. We identified higher levels in air and on surfaces at both proximal and farmworker households. Our findings further confirm the presence of pesticides and their oxygen analogs in air and highlight their potential for infiltration of indoor living environments. Citation: Gibbs JL, Yost MG, Negrete M, Fenske RA. 2017. Passive sampling for indoor and outdoor exposures to chlorpyrifos, azinphos-methyl, and oxygen analogs in a rural agricultural community. Environ Health Perspect 125:333-341; http://dx.doi.org/10.1289/EHP425.

Breathing zone air sampler

DOEpatents

Tobin, John

1989-01-01

A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

Tritium Concentrations in Environmental Samples and Transpiration Rates from the Vicinity of Mary's Branch Creek and Background Areas, Barnwell, South Carolina, 2007-2009

USGS Publications Warehouse

Vroblesky, Don A.; Canova, Judy L.; Bradley, Paul M.; Landmeyer, James E.

2009-01-01

Tritium in groundwater from a low-level radioactive waste disposal facility near Barnwell, South Carolina, is discharging to Mary's Branch Creek. The U.S. Geological Survey conducted an investigation from 2007 to 2009 to examine the tritium concentration in trees and air samples near the creek and in background areas, in groundwater near the creek, and in surface water from the creek. Tritium was found in trees near the creek, but not in trees from background areas or from sites unlikely to be in direct root contact with tritium-contaminated groundwater. Tritium was found in groundwater near the creek and in the surface water of the creek. Analysis of tree material has the potential to be a useful tool in locating shallow tritium-contaminated groundwater. A tritium concentration of 1.4 million picocuries per liter was measured in shallow groundwater collected near a tulip poplar located in an area of tritium-contaminated groundwater discharge. Evapotranspiration rates from the tree and tritium concentrations in water extracted from tree cores indicate that during the summer, this tulip poplar may remove more than 17.1 million picocuries of tritium per day from the groundwater that otherwise would discharge to Mary's Branch Creek. Analysis of air samples near the tree showed no evidence that the transpirative release of tritium to the air created a vapor hazard in the forest.

Determination of hexavalent chromium in exhaled breath condensate and environmental air among chrome plating workers.

PubMed

Goldoni, Matteo; Caglieri, Andrea; Poli, Diana; Vettori, Maria Vittoria; Corradi, Massimo; Apostoli, Pietro; Mutti, Antonio

2006-03-15

Chromium speciation has attracted attention because of the different toxicity of Cr(III), which is considered relatively non-toxic, and Cr(VI), which can cross cell membranes mainly as a chromate anion and has been classified as a class I human carcinogen. The aims of the present study were to measure soluble Cr(VI) levels in environmental samples, to develop a simple method of quantifying Cr(VI) in exhaled breath condensate (EBC), and to follow the kinetics of EBC Cr(VI) in chrome plating workers.Personal air samples were collected from 10 chrome platers; EBC was collected from the same workers immediately after the work shift on Tuesday and before the work shift on the following Wednesday. Environmental and EBC Cr(VI) levels were determined by means of colorimetry and electrothermal absorption atomic spectrometry, respectively.The method of detecting Cr(VI) in environmental air was based on the extraction of the Cr(VI)-diphenylcarbazide (Cr(VI)-DPC) complex in 1-butanol, whereas EBC Cr(VI) was determined using a solvent extraction of Cr(VI) as an ion pair with tetrabutylammonium ion, and subsequent direct determination of the complex (Cr(VI)-DPC) in EBC.Kinetic data showed that airborne Cr(VI) was reduced by 50% in airway lining fluid sampled at the end of exposure and that there was a further 50% reduction after about 15 h. The persistence of Cr(VI) in EBC supports the use of EBC in assessing target tissue levels of Cr(VI).

A Summary of Research and Progress on Carbon Monoxide Exposure Control Solutions on Houseboats

PubMed Central

Hall, Ronald M.; Earnest, G. Scott; Hammond, Duane R.; Dunn, Kevin H.; Garcia, Alberto

2015-01-01

Investigations of carbon monoxide (CO-related poisonings and deaths on houseboats were conducted by the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. These investigations measured hazardous CO concentrations on and around houseboats that utilize gasoline-powered generators. Engineering control devices were developed and tested to mitigate this deadly hazard. CO emissions were measured using various sampling techniques which included exhaust emission analyzers, detector tubes, evacuated containers (grab air samples analyzed by a gas chromatograph), and direct-reading CO monitors. CO results on houseboats equipped with gasoline-powered generators without emission controls indicated hazardous CO concentrations exceeding immediately dangerous to life and health (IDLH) levels in potentially occupied areas of the houseboat. Air sample results on houseboats that were equipped with engineering controls to remove the hazard were highly effective and reduced CO levels by over 98% in potentially occupied areas. The engineering control devices used to reduce the hazardous CO emissions from gasoline-powered generators on houseboats were extremely effective at reducing CO concentrations to safe levels in potentially occupied areas on the houseboats and are now beginning to be widely used. PMID:24568306

Haloacetates in fog and rain.

PubMed

Römpp, A; Klemm, O; Fricke, W; Frank, H

2001-04-01

Atmospheric haloacetates can arise from photochemical degradation of halogenated hydrocarbons and from direct anthropogenic emissions. Furthermore, there is also evidence of natural sources although these are quantitatively uncertain. As haloacetates are highly soluble in water, hydrometeors are most significant for their deposition. Fogwater (96 samples) and rainwater samples (over 100 samples) were collected from July 1998 to March 1999 at an ecological research site in northeastern Bavaria, Germany. They were analyzed for monofluoroacetate (MFA), difluoroacetate (DFA), trifluoroacetate (TFA), monochloroacetate (MCA), dichloroacetate (DCA), trichloroacetate (TCA), monobromoacetate (MBA), and dibromoacetate (DBA). The major inorganic ions were also determined. High concentrations of up to 11 microg/L MCA, 5 microg/L DCA, 2 microg/L TCA, and 2 microg/L TFA were found in fogwater associated with westerly winds. Backward trajectories were calculated to determine the origin of the air masses. MBA and DBA have highest concentrations in fogwater advected with air originating from the Atlantic, suggesting the marine origin of these two compounds. All analyzed substances show higher average concentrations in fog than in rain. Estimates of the deposition of haloacetates suggest that the contribution of fog may be more important than rain for the total burden of a forest ecosystem.

A summary of research and progress on carbon monoxide exposure control solutions on houseboats.

PubMed

Hall, Ronald M; Earnest, G Scott; Hammond, Duane R; Dunn, Kevin H; Garcia, Alberto

2014-01-01

Investigations of carbon monoxide (CO-related poisonings and deaths on houseboats were conducted by the Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health. These investigations measured hazardous CO concentrations on and around houseboats that utilize gasoline-powered generators. Engineering control devices were developed and tested to mitigate this deadly hazard. CO emissions were measured using various sampling techniques which included exhaust emission analyzers, detector tubes, evacuated containers (grab air samples analyzed by a gas chromatograph), and direct-reading CO monitors. CO results on houseboats equipped with gasoline-powered generators without emission controls indicated hazardous CO concentrations exceeding immediately dangerous to life and health (IDLH) levels in potentially occupied areas of the houseboat. Air sample results on houseboats that were equipped with engineering controls to remove the hazard were highly effective and reduced CO levels by over 98% in potentially occupied areas. The engineering control devices used to reduce the hazardous CO emissions from gasoline-powered generators on houseboats were extremely effective at reducing CO concentrations to safe levels in potentially occupied areas on the houseboats and are now beginning to be widely used.

Magnetic biomonitoring of industrial air pollution in SW Finland

NASA Astrophysics Data System (ADS)

Salo, Hanna; Mäkinen, Joni

2015-04-01

Moss bags made of Sphagnum papillosum were exposed along 8 km transects near Harjavalta Industrial Park in SW Finland. Previous studies have identified Cu-Ni smelter's pipe as the main source of air pollution. Our research hypothesis is that nowadays the local pollution load of airborne particulate matter from Industrial Park is mainly caused by other emission sources than the smelter's pipe. To identify possible magnetic fingerprints, industrial samples (fiberglass filters from the smokestacks of Cu-Ni smelter and Ni-dryer, final Cu-slag, granulated Ni-slag, Cu-concentrates, Ni-concentrates) were investigated. Mass-specific susceptibility and heavy metal levels were significantly higher near Industrial Park and showed a decreasing trend with increasing distance from the source. The magnetic mineralogy of moss bags, smelter's filter and Cu-slag was dominated by a low-coercivity magnetite while high-coercivity minerals were observed in dryer's filter, Ni-slag and majority of concentrates including all Ni-concentrates. Angular and sharp-edged particles prevailed in moss bags and industrial samples, except for smelter's filter and granulated Ni-slag in which spherical particles dominated. Seven air pollution impact zones were distinguished around Industrial Park on the basis of magnetic susceptibility and previous studies. Overall, industrial area's influence is observable up to 4 km and even further distances in SE and NW along prevailing wind directions and Kokemäenjoki River valley. The heaviest anthropogenic air pollution load is deposited at 0.5-1 km distances. Particle morphology and magnetic data of the moss bags indicate that the particulate matter in the hot spot area, which spatial emphasis is in S-SW-W-NW in the upwind from the smelter, originate mainly from the dust emissions from other sources rather than the smelter's pipe. The industrial activities in and nearby hot spot area include handling and moving of concentrates and slags as well as heavy traffic. This study shows that air pollution from various dust-providing sources outweighs the fly-ash load from the Cu-Ni smelter's pipe especially at short distances. Furthermore, active magnetic monitoring by moss bags is spatially detailed sampling method for the identification of air pollutants and emission sources.

Direct Monitoring of Trace Atmospheric Species via Ion Trap Mass Spectrometry

NASA Technical Reports Server (NTRS)

Palmer, P. T.; Pearson, Richard; Saimonson, Jay D.; Wong, Carla M.; Lawless, James G. (Technical Monitor)

1994-01-01

There is an ever-increasing emphasis on the part of government agencies, academia, and industry on enhancing our understanding of atmospheric processes and assessing the impact of human activities on these processes. While issues such as the ozone hole and rising levels of greenhouse gases have received major attention. relatively little is known about the types, concentrations, sources, and sinks of hydrocarbons in the troposphere and stratosphere. Such information would be of tremendous utility in assessing the roles of various anthropogenic and biogenic processes on global carbon cycles. An ion trap mass spectrometer has been developed for monitoring trace levels of hydrocarbons in the atmosphere on NASA's DC-8 "flying laboratory". This aircraft is used to provide measurements in support of a number of "Mission to Planet Earth" activities and tropospheric chemistry experiments. In past missions, specific compounds have been monitored via highly specialized instrumentation, fast GO, or collection of whole air samples for subsequent ground-based analysis. The ion trap has several features. including small size. excellent sensitivity, and broad applicability, which make it highly atttrat:ive for atmospheric monitoring. The design of this instrument, its air sampling interface. and the various complications associated with aircraft-deployment will be described. Data showing the sensitivity of the instrument for detecting hydrocarbons at mixing ratios below one part-per-billion, and the use of MS/MS for direct, on-line, real-time monitoring will be presented.

Analysis of snow-cap pollution for air quality assessment in the vicinity of an oil refinery.

PubMed

Krastinyte, Viktorija; Baltrenaite, Edita; Lietuvninkas, Arvydas

2013-01-01

Snow-cap can be used as a simple and effective indicator of industrial air pollution. In this study snow-cap samples were collected from 11 sites located in the vicinity of an oil refinery in Mazeikiai, a region in the north-west of Lithuania, in the winter of 2011. Analysis of snowmelt water and snow-dust was used to determine anthropogenic pollutants such as: sulphates and chlorides, nitrites, nitrates, ammonium nitrogen, total carbon, total nitrogen; heavy metals: lead (Pb), copper (Cu), chromium (Cr), cadmium (Cd). Concentrations of heavy metals in snow-dust were detected thousands of times higher than those in the snowmelt water. In this study, analysis of heavy metal concentration was conducted considering different distances and the wind direction within the impact zone of the oil refinery. The sequence of heavy metals according to their mean concentrations in the snow-dust samples was the following: Pb > Cr > Cu > Cd. Heavy metals highly correlated among each other. The load of snow-dust was evaluated to determine the pollution level in the study area. The highest daily load of snow-dust was 45.81 +/- 12.35 mg/m2 in the north-western direction from the oil refinery. According to classification of the daily load of snow-dust a lower than medium-risk level of pollution was determined in the vicinity of the oil refinery.

Sequential air sampler system : its use by the Virginia Department of Highways & Transportation.

DOT National Transportation Integrated Search

1975-01-01

The Department of Highways & Transportation needs an economical and efficient air quality sampling system for meeting requirements on air monitoring for proposed projects located In critical areas. Two sequential air sampling systems, the ERAI and th...

Identification of Chemicals of Interest to the Department of Defense and U.S. Air Force Among the U.S. Environmental Protection Agency’s Integrated Risk Information System Chemicals that are Due for Reassessment of their Toxicity Values

DTIC Science & Technology

2010-03-16

Exceeded at ERP Soil and Groundwater Sites 86 A-2a. Identification of IRIS Chemicals of Interest on the ATSDR CERCLA Priority List of Hazardous...the Number (Bold Font) of Air Force ERP Samples in Which They Were Detected 317 A-4d. Air Force ERP Soil Samples: IRIS Chemicals of Interest...Ranked by the Number (Bold Font) of Air Force ERP Soil Samples in Which They Were Detected 333 A-4e. Air Force ERP Groundwater Samples: IRIS Chemicals of

Presence of pathogenic microorganisms in power-plant cooling waters. Final report, October 1, 1981-June 30, 1983

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

Tyndall, R.L.

1983-07-01

Air was sampled at the point of discharge and at short distances downwind and upwind from industrial and power-plant cooling towers. Both high-volume electrostatic and impinger type samplers were used. Concentrates of the air samples were analyzed for Legionnaires' Disease Bacteria (LDB). In some cases, the samples were also tested for the presence of free-living amoebae. The concentrations of LDB in the air samples were well below the minimal infectious dose for guinea pigs and precluded testing of the samples for infectious LDB. Results of LDB analysis were related to the meteorological conditions at the time of sampling. Generally, themore » concentrations of LDB in the air at the discharge of the cooling towers were 1 x 10/sup -6/ to 1 x 10/sup -7/ of that found in comparable volumes of tower basin water. During periods of high humidity and wind speed, LDB was detected in a few downwind samples and one upwind sample. One site with extensive construction and excavation activity had higher LDB concentrations in air samples relative to other sites. Nonpathogenic Naegleria were present in one of two air samples taken in the mist at the base of a natural-draft cooling tower.« less

Miniature open channel scrubbers for gas collection.

PubMed

Toda, Kei; Koga, Tomoko; Tanaka, Toshinori; Ohira, Shin-Ichi; Berg, Jordan M; Dasgupta, Purnendu K

2010-10-15

An open channel scrubber is proposed as a miniature fieldable gas collector. The device is 100mm in length, 26 mm in width and 22 mm in thickness. The channel bottom is rendered hydrophilic and liquid flows as a thin layer on the bottom. Air sample flows atop the appropriately chosen flowing liquid film and analyte molecules are absorbed into the liquid. There is no membrane at the air-liquid interface: they contact directly each other. Analyte species collected over a 10 min interval are determined by fluorometric flow analysis or ion chromatography. A calculation algorithm was developed to estimate the collection efficiency a priori; experimental and simulated results agreed well. The characteristics of the open channel scrubber are discussed in this paper from both theoretical and experimental points of view. In addition to superior collection efficiencies at relatively high sample air flow rates, this geometry is particularly attractive that there is no change in collection performance due to membrane fouling. We demonstrate field use for analysis of ambient SO(2) near an active volcano. This is basic investigation of membraneless miniature scrubber and is expected to lead development of an excellent micro-gas analysis system integrated with a detector for continuous measurements. Copyright © 2010 Elsevier B.V. All rights reserved.

Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow.

PubMed

Teng, Tun-Ping; Hung, Yi-Hsuan; Teng, Tun-Chien; Chen, Jyun-Hong

2011-08-09

This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study measured the thermal conductivity and viscosity of nanofluid with weight fractions and sample temperatures (20-60°C), and then used the nanofluid in an actual air-cooled heat exchanger to assess its heat exchange capacity and pressure drop under laminar flow. Experimental results show that the nanofluid has a higher heat exchange capacity than water, and a higher concentration of nanoparticles provides an even better ratio of the heat exchange. The maximum enhanced ratio of heat exchange and pressure drop for all the experimental parameters in this study was about 39% and 5.6%, respectively. In addition to nanoparticle concentration, the temperature and mass flow rates of the working fluid can affect the enhanced ratio of heat exchange and pressure drop of nanofluid. The cross-section aspect ratio of tube in the heat exchanger is another important factor to be taken into consideration.

Influence of Atmosphere on Electrochemical Performance of LiNi0.8Co0.1Mn0.1O2 Electrodes for Li-Ion Batteries

NASA Astrophysics Data System (ADS)

Wang, Ran; Wang, Jing; Chen, Shi; Gao, Ang; Su, Yuefeng; Wu, Feng

2018-01-01

Ni-rich layered materials have been regarded as competitive candidates for advanced lithium-ion batteries due to their high energy density, relatively low cost and environmentally-friendly nature. However, they suffer from serious degradation of cycling performance after exposing to air during their storage. Here we selected LiNi0.8Co0.1Mn0.1O2 as a typical Ni-rich positive material to study the influence upon exposure to ambient air on surface chemical composition and electrochemical performance. TEM confirms the existence of amorphous surface layer after contacting with atmosphere and the thickness is about 3-4 nm. The fresh LiNi0.8Co0.1Mn0.1O2 sample has capacity retention of 94.6% and 93.3% after 50 cycles at 0.2C and 1C, respectively, comparing to the 91.7% and 82.4% of the exposed sample. The charge-discharge curves and electrochemical impedance spectra indicate that exposure to air lead to increased impedance and polarization, which seriously affects LiNi0.8Co0.1Mn0.1O2 cycling properties. So, it is very important for Ni-rich cathode materials without contacting with atmosphere directly.

Performance evaluation on an air-cooled heat exchanger for alumina nanofluid under laminar flow

PubMed Central

2011-01-01

This study analyzes the characteristics of alumina (Al2O3)/water nanofluid to determine the feasibility of its application in an air-cooled heat exchanger for heat dissipation for PEMFC or electronic chip cooling. The experimental sample was Al2O3/water nanofluid produced by the direct synthesis method at three different concentrations (0.5, 1.0, and 1.5 wt.%). The experiments in this study measured the thermal conductivity and viscosity of nanofluid with weight fractions and sample temperatures (20-60°C), and then used the nanofluid in an actual air-cooled heat exchanger to assess its heat exchange capacity and pressure drop under laminar flow. Experimental results show that the nanofluid has a higher heat exchange capacity than water, and a higher concentration of nanoparticles provides an even better ratio of the heat exchange. The maximum enhanced ratio of heat exchange and pressure drop for all the experimental parameters in this study was about 39% and 5.6%, respectively. In addition to nanoparticle concentration, the temperature and mass flow rates of the working fluid can affect the enhanced ratio of heat exchange and pressure drop of nanofluid. The cross-section aspect ratio of tube in the heat exchanger is another important factor to be taken into consideration. PMID:21827644

Superfund record of decision (EPA Region 10): Mountain Home Air Force Base, Site 8, Fire Training Area 8, Operable Unit 4, Elmore County, Mountain Home, ID. (First remedial action), June 1992. Final report

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

Not Available

1992-06-16

The 7-acre Mountain Home Air Force Base (AFB) site was a fire department training area located in Mountain Home, Elmore County, Idaho. From 1962 to 1975, the Mountain Home Air Force Base used the site for fire department training exercises. Each exercise began by saturating the bermed training area with water, followed directly by applying 250 to 500 gallons of fuel. The flames were extinguished with Aqueous Film Forming Foam (AFFF), or prior to 1972, with a water-based protein foam. The training session was completed with a post-exercise ignition of the residual fuel in a bermed area. The USAF investigationsmore » identified solvents and petroleum, oil, lubricant (POL) wastes in the soil. Under the Installation Restoration Program (IRP), the USAF conducted a record search, drilling, and sampling of soil borings to bedrock, the installation of monitoring wells, and hand auger samples. The ROD provided a final remedy for onsite soil as OU4. Because contaminants were found at such low concentrations, the soil was covered by crushed asphalt and has little potential to impact ecological receptors. The soil posed low risks for humans at the site and no remediation was necessary.« less

The role of the subelytral spiracles in respiration in the flightless dung beetle Circellium bacchus.

PubMed

Byrne, Marcus J; Duncan, Frances D

2003-04-01

The role of the subelytral cavity in flightless beetle species as an adaptation to water saving in arid habitats is still in dispute. We found that relatively little CO(2) was released from the subelytral cavity of a large apterous beetle Circellium bacchus during simultaneous measurements of CO(2) emission from the anterior mesothoracic spiracles and posterior body, which included the subelytral spiracles. However, when we sampled air directly from inside the subelytral cavity, we discovered that this pattern was reversed. A discontinuous gas exchange cycle (DGC) was recorded from the posterior body half, revealing a flutter phase that had been absent from the anterior mesothoracic DGC. The anterior mesothoracic and posterior subelytral spiracles act in synchrony to maintain high CO(2) and water vapour levels inside the subelytral cavity. In addition, the O(2) concentration of the air within the subelytral cavity is lower than the air around the elytral case, irrespective of the time of sampling. These findings lead us to conclude that the subelytral spiracles work in a coordinated fashion with the anterior spiracles to create a DGC, which allows us to extend the hypothesis of the function of the subelytral cavity as a respiratory water-saving device.

Small-size mass spectrometer for determining gases and volatile compounds in air during breathing

NASA Astrophysics Data System (ADS)

Kogan, V. T.; Kozlenok, A. V.; Chichagov, Yu. V.; Antonov, A. S.; Lebedev, D. S.; Bogdanov, A. A.; Moroshkin, V. S.; Berezina, A. V.; Viktorova-Leclerc, O. S.; Vlasov, S. A.; Tubol'tsev, Yu. V.

2015-10-01

We describe an automated mass spectrometer for diagnostics of deceases from the composition of exhaled air. It includes a capillary system, which performs a rapid direct feeding of the sample to the instrument without changing substantially its composition and serves for studying the dynamics of variation of the ratio between various components of exhaled air. The membrane system for introducing the sample is intended for determining low concentrations of volatile organic compounds which are biomarkers of pathologies. It is characterized by selective transmittance and ensures the detection limits of target compounds at the parts per million-parts per billion (ppm-ppb) level. A static mass analyzer operating on permanent magnets possesses advantages important for mobile devices as compared to its dynamic analogs: it is more reliable in operation, has a larger dynamic range, and can be used for determining the concentration of components in the mixture one-by-one or simultaneously. The curvilinear output boundary of the magnetic lens of the mass analyzer makes it possible to reduce its weight and size by 2.5 times without deteriorating the mass resolution. We report on the results of testing of the instrument and consider the possibility of its application for early detection of deceases of respiratory and blood circulation system, gastrointestinal tract, and endocrine system.

Characterization of air contaminants formed by the interaction of lava and sea water.

PubMed

Kullman, G J; Jones, W G; Cornwell, R J; Parker, J E

1994-05-01

We made environmental measurements to characterize contaminants generated when basaltic lava from Hawaii's Kilauea volcano enters sea water. This interaction of lava with sea water produces large clouds of mist (LAZE). Island winds occasionally directed the LAZE toward the adjacent village of Kalapana and the Hawaii Volcanos National Park, creating health concerns. Environmental samples were taken to measure airborne concentrations of respirable dust, crystalline silica and other mineral compounds, fibers, trace metals, inorganic acids, and organic and inorganic gases. The LAZE contained quantifiable concentrations of hydrochloric acid (HCl) and hydrofluoric acid (HF); HCl was predominant. HCl and HF concentrations were highest in dense plumes of LAZE near the sea. The HCl concentration at this sampling location averaged 7.1 ppm; this exceeds the current occupational exposure ceiling of 5 ppm. HF was detected in nearly half the samples, but all concentrations were <1 ppm Sulfur dioxide was detected in one of four short-term indicator tube samples at approximately 1.5 ppm. Airborne particulates were composed largely of chloride salts (predominantly sodium chloride). Crystalline silica concentrations were below detectable limits, less than approximately 0.03 mg/m3 of air. Settled dust samples showed a predominance of glass flakes and glass fibers. Airborne fibers were detected at quantifiable levels in 1 of 11 samples. These fibers were composed largely of hydrated calcium sulfate. These findings suggest that individuals should avoid concentrated plumes of LAZE near its origin to prevent over exposure to inorganic acids, specifically HCl.

Air sampling results in relation to extent of fungal colonization of building materials in some water-damaged buildings.

PubMed

Miller, J D; Haisley, P D; Reinhardt, J H

2000-09-01

We studied the extent and nature of fungal colonization of building materials in 58 naturally ventilated apartments that had suffered various kinds of water damage in relation to air sampling done before the physical inspections. The results of air samples from each apartment were compared by rank order of species with pooled data from outdoor air. Approximately 90% of the apartments that had significant amounts of fungi in wall cavities were identified by air sampling. There was no difference in the average fungal colony forming unit values per m3 between the 15 apartments with the most fungal contamination and the 15 with the least. In contrast, the prevalence of samples with fungal species significantly different than the pooled outdoor air between the more contaminated versus the less contaminated apartments was approximately 10-fold. We provide information on methods to document fungal contamination in buildings.

Detection of the urban release of a bacillus anthracis simulant by air sampling.

PubMed

Garza, Alexander G; Van Cuyk, Sheila M; Brown, Michael J; Omberg, Kristin M

2014-01-01

In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques.

Noble Gas Signatures in Groundwater and Rainwater on the Island of Maui, Hawaii - Developing a New Noble Gas Application in Fractured, Volcanic Systems

NASA Astrophysics Data System (ADS)

Castro, M. C.; Niu, Y.; Warrier, R. B.; Hall, C. M.; Gingerich, S. B.; Scholl, M. A.; Bouvier, L.

2014-12-01

Recent work in the Galapagos Islands suggests that noble gas temperatures (NGTs) in fractured groundwater systems reflect the temperature of the ground surface at the time of infiltration rather than the mean annual air temperature (MAAT) value as commonly assumed in sedimentary systems where NGTs are typically used as indicators of past climate. This suggests that noble gases in fractured areas may record seasonality, and thus, provide information about timing of recharge in addition to location. Calculation of NGTs assumes that rain-derived recharge at the water table is in equilibrium with ground air. Lack of noble gas equilibration with respect to surface conditions, however, was observed in high-altitude springs in the Galapagos Islands and in a rainwater pilot study in Michigan, supporting the NGT seasonality hypothesis. Developing this new NGT application will lead to a better understanding of fractured groundwater flow systems and will contribute to improved water resource management plans. This study, carried out on Maui, Hawaii, is meant to test these hypotheses while improving knowledge of this island's groundwater flow system where limited hydrologic data are available. Here, we present the first results of noble gas analyses from samples collected in springs, groundwater wells and rainwater on northeast Maui. Results show that like most Michigan rainwater samples, rainwater from Maui is in disequilibrium with surface conditions and follows a mass-dependent pattern. Spring samples follow a similar pattern to that of rainwater and suggest that spring water originates directly from rainfall. These findings further support the hypothesis of NGT seasonality. However, while the atmospheric composition of noble gases points to direct supply from rainfall to spring aquifer systems, a direct connection between spring water and deeper aquifer levels or the mantle is apparent from He isotopic ratios which display an almost pure He mantle component in some springs.

Human Occupancy as a Source of Indoor Airborne Bacteria

PubMed Central

Hospodsky, Denina; Qian, Jing; Nazaroff, William W.; Yamamoto, Naomichi; Bibby, Kyle; Rismani-Yazdi, Hamid; Peccia, Jordan

2012-01-01

Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM10 and PM2.5 size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM10. On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments. PMID:22529946

[Transport and differentiation of polycyclic aromatic hydrocarbons in air from Dashiwei karst Sinkholes in Guangxi, China].

PubMed

Kong, Xiang-Sheng; Qi, Shi-Hua; Sun, Qian; Huang, Bao-Jian

2012-12-01

The typical karst Dashiwei Sinkholes located in Leye County, Guangxi were chosen as the study object. The air samples from the opening of Dashiwei Sinkholes to the underground river profiles were collected by polyurethane foam passive samplers (PUF-PAS), and the meteorological parameters were observed. The 16 PAHs were analyzed using GC-MS. The results showed that the total PAHs concentration in air in Dashiwei Sinkholes ranged from 33.76 ng x d(-1) to 150.86 ng x d(-1), with an average of 80.36 ng x d(-1). The mean concentrations in the cliff, the bottom and the underground river profiles were 67.17, 85.36 and 101.67 ng x d(-1), respectively. The 2-3 rings PAHs (including phenanthrene, anthracene, napnthalene and fluorene) accounted for 87.97% of the total of PAHs. The transport and accumulation processes of PAHs in air in Dashiwei Sinkholes were: the ground to the cliff section to the bottom section and then to the underground river, and the total PAHs concentrations showed an obvious increasing tendency with the decrease in altitude or increase in the length of the underground river. Low molecular weight PAHs compounds (including phenanthrene, anthracene, flourene and fluoranthene) in air went through differentiation at the bottom of the west peak, the bottom of the sinkhole and the underground river. The primary sources of PAHs were pyrogenic sources with atmosphere transport. Ambient temperature was the predominating factor influencing the transport and accumulation of gas phase PAHs in Dashiwei Sinkholes, following by wind speed, wind direction and relative humidity. Relative humidity and the temperature were the predominating factors influencing the differentiation, following by wind speed and wind direction. As a whole, a "cold trapping effect" of POPs was showed obviously in Dashiwei Sinkholes.

Gas turbine topping combustor

DOEpatents

Beer, J.; Dowdy, T.E.; Bachovchin, D.M.

1997-06-10

A combustor is described for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone. 14 figs.

Microbial structure and chemical components of aerosols caused by rotating brushes in a wastewater treatment plant.

PubMed

Han, Yunping; Li, Lin; Liu, Junxin; Zhang, Mengzhu

2012-11-01

Bacterial community structure and the chemical components in aerosols caused by rotating brushes in an Orbal oxidation ditch were assessed in a Beijing municipal wastewater treatment plant. Air samples were collected at different distances from the aerosol-generating rotating brushes. Molecular culture-independent methods were used to characterize the community structure of the airborne bacteria in each sample regardless of cell culturability. A clone library of 16S rDNA directly amplified from air DNA of each sample was constructed and sequenced to analyze the community composition and diversity. Insoluble particles and water-soluble ions emitted with microorganisms in aerosols were analysis by a scanning electron microscope together with energy dispersive X-ray spectroscopy and ion chromatogram analyzer. In total, most of the identified bacteria were Proteobacteria. The majority of sequences near the rotating brushes (the main source of the bioaerosols) were Proteobacteria (62.97 %) with β-(18.52 %) and γ-(44.45 %) subgroups and Bacteroidetes (29.63 %). Complex patterns were observed for each sampling location, suggesting a highly diverse community structure, comparable to that found in water in the Orbal oxidation ditch. Accompany with microorganisms, 46.36 μg/m(3) of SO (4) (2-) , 29.35 μg/m(3) of Cl(-), 21.51 μg/m(3) of NO (3) (-) , 19.76 μg/m(3) of NH (4) (+) , 11.42 μg/m(3) of PO (4) (3-) , 6.18 μg/m(3) of NO (2) (-) , and elements of Mg, Cl, K, Na, Fe, S, and P were detected from the air near the aerosols source. Differences in the structure of the bacterial communities and chemical components in the aerosols observed between sampling sites indicated important site-related variability. The composition of microorganisms in water was one of the most important sources of bacterial communities in bioaerosols. Chemical components in bioaerosols may provide a media for airborne microorganism attachment, as well as a suitable microenvironment for their growth and survival in the air. This study will be benefit for the formulation of pollution standards, especially for aerosols, that take into account plant workers' health.

[Microbial air monitoring in operating theatre: active and passive samplings].

PubMed

Pasquarella, C; Masia, M D; Nnanga, Nga; Sansebastiano, G E; Savino, A; Signorelli, C; Veronesi, L

2004-01-01

Microbial air contamination was evaluated in 11 operating theatres using active and passive samplings. SAS (Surface Air System) air sampling was used to evaluate cfu/m3 and settle plates were used to measure the index of microbial air contamination (IMA). Samplings were performed at the same time on three different days, at three different times (before, during and after the surgical activity). Two points were monitored (patient area and perimeter of the operating theatre). Moreover, the cfu/m3 were evaluated at the air inlet of the conditioner system. 74.7% of samplings performed at the air inlet and 66.7% of the samplings performed at the patient area before the beginning of the surgical activity (at rest) exceeded the 35 cfu/m3 used as threshold value. 100% of IMA values exceeded the threshold value of 5. Using both active and passive sampling, the microbial contamination was shown to increase significantly during activity. The cfu values were higher at the patient area than at the perimeter of the operating theatre. Mean values of the cfu/m3 during activity at the patient area ranged from a minimum of 61+/-41 cfu/m3 to a maximum of 242+/-136 cfu/m3; IMA values ranged from a minimum of 19+/-10 to a maximum of 129+/-60. 15.2% of samplings performed at the patient area using SAS and 75.8% of samplings performed using settle plates exceeded the threshold values of 180 cfu/m3 and 25 respectively, with a significant difference of the percentages. The highest values were found in the operating theatre with inadequate structural and managerial conditions. These findings confirm that the microbiological quality of air may be considered a mirror of the hygienic conditions of the operating theatre. Settle plates proved to be more sensitive in detecting the increase of microbial air contamination related to conditions that could compromise the quality of the air in operating theatres.

Comparison of indoor air sampling and dust collection methods for fungal exposure assessment using quantitative PCR.

PubMed

Cox, Jennie; Indugula, Reshmi; Vesper, Stephen; Zhu, Zheng; Jandarov, Roman; Reponen, Tiina

2017-10-18

Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample collected with a Button™ inhalable aerosol sampler and four types of dust samples: a vacuumed floor dust sample, newly settled dust collected for four weeks onto two types of electrostatic dust cloths (EDCs) in trays, and a wipe sample of dust from above floor surfaces. The samples were obtained in the bedrooms of asthmatic children (n = 14). Quantitative polymerase chain reaction (qPCR) was used to analyze the dust and air samples for the 36 fungal species that make up the Environmental Relative Moldiness Index (ERMI). The results from the samples were compared by four matrices: total concentration of fungal cells, concentration of fungal species associated with indoor environments, concentration of fungal species associated with outdoor environments, and ERMI values (or ERMI-like values for air samples). The ERMI values for the dust samples and the ERMI-like values for the 48 hour air samples were not significantly different. The total cell concentrations of the 36 species obtained with the four dust collection methods correlated significantly (r = 0.64-0.79, p < 0.05), with the exception of the vacuumed floor dust and newly settled dust. In addition, fungal cell concentrations of indoor associated species correlated well between all four dust sampling methods (r = 0.68-0.86, p < 0.01). No correlation was found between the fungal concentrations in the air and dust samples primarily because of differences in concentrations of Cladosporium cladosporioides Type 1 and Epicoccum nigrum. A representative type of dust sample and a 48 hour air sample might both provide useful information about fungal exposures.

Permeation-solid adsorbent sampling and GC analysis of formaldehyde.

PubMed

Muntuta-Kinyanta, C; Hardy, J K

1991-12-01

A passive method with membrane permeation sampling for the determination of time-weighted-average (TWA) concentration of formaldehyde in air is described. The sampling device was constructed by affixing an unbacked dimethyl silicone membrane to the base of a glass tube and by sealing the top with a rubber stopper. Formaldehyde permeates the membrane and reacts with 2-(hydroxymethyl)piperidine (2-HMP) coated on the surface of XAD-2. Sampling times from 15 min to 8 hr have been used. The formaldehyde-oxazolidine produced is thermally desorbed and determined by a packed column gas chromatograph equipped with a flame ionization detector (FID). The response of the monitor is directly proportional to the external concentration of formaldehyde over the concentration range 0.050-100 ppm. The permeation constant (the slope of the permeation curve) of the membrane is 0.333 mug ppm(-1). hr, and the detection limit of the method is 0.03 ppm for an 8-hr sampling period. Relative humidity (RH) (35-94%), temperature (0-82 degrees ) and storage period (0-25 days) do not affect the permeation process for sample collection. Moreover, potential chemical interferences, 10 ppm acetone or acrolein, respectively, have no detectable effect on the process. The method gives TWA concentration directly from the measurements, and the equipment is economical and convenient for personal or multi-location sample collections.

Preliminary assessment of using tree-tissue analysis and passive-diffusion samplers to evaluate trichloroethene contamination of ground water at Site SS-34N, McChord Air Force Base, Washington, 2001

USGS Publications Warehouse

Cox, S.E.

2002-01-01

Two low-cost innovative sampling procedures for characterizing trichloroethene (TCE) contamination in ground water were evaluated for use at McChord Air Force Base (AFB) by the U.S. Geological Survey, in cooperation with the U.S. Air Force McChord Air Force Base Installation Restoration Program, in 2001. Previous attempts to characterize the source of ground-water contamination in the heterogeneous glacial outwash aquifer at McChord site SS-34N using soil-gas surveys, direct-push exploration, and more than a dozen ground-water monitoring wells have had limited success. The procedures assessed in this study involved analysis of tree-tissue samples to map underlying ground-water contamination and deploying passive-diffusion samplers to measure TCE concentrations in existing monitoring wells. These procedures have been used successfully at other U.S. Department of Defense sites and have resulted in cost avoidance and accelerated site characterization. Despite the presence of TCE in ground water at site SS-34N, TCE was not detected in any of the 20 trees sampled at the site during either early spring or late summer sampling. The reason the tree tissue procedure was not successful at the McChord AFB site SS-34N may have been due to an inability of tree roots to extract moisture from a water table 30 feet below the land surface, or that concentrations of TCE in ground water were not large enough to be detectable in the tree tissue at the sampling point. Passive-diffusion samplers were placed near the top, middle, and bottom of screened intervals in three monitoring wells and TCE was observed in all samplers. Concentrations of TCE from the passive-diffusion samplers were generally similar to concentrations found in samples collected in the same wells using conventional pumping methods. In contrast to conventional pumping methods, the collection of ground-water samples using the passive-diffusion samples did not generate waste purge water that would require hazardous-waste disposal. In addition, the results from the passive-diffusion samples may show that TCE concentrations are stratified across some screened intervals. The overall results of the limited test of passive-diffusion samplers at site SS-34N were similar to more detailed tests conducted at other contaminated sites across the country and indicate that further evaluation of the use of passive-diffusion samplers at McChord site SS-34N is warranted.

Isokinetic air sampler

DOEpatents

Sehmel, George A.

1979-01-01

An isokinetic air sampler includes a filter, a holder for the filter, an air pump for drawing air through the filter at a fixed, predetermined rate, an inlet assembly for the sampler having an inlet opening therein of a size such that isokinetic air sampling is obtained at a particular wind speed, a closure for the inlet opening and means for simultaneously opening the closure and turning on the air pump when the wind speed is such that isokinetic air sampling is obtained. A system incorporating a plurality of such samplers provided with air pumps set to draw air through the filter at the same fixed, predetermined rate and having different inlet opening sizes for use at different wind speeds is included within the ambit of the present invention as is a method of sampling air to measure airborne concentrations of particulate pollutants as a function of wind speed.

A system for high-quality CO2 isotope analyses of air samples collected by the CARIBIC Airbus A340-600.

PubMed

Assonov, S; Taylor, P; Brenninkmeijer, C A M

2009-05-01

In 2007, JRC-IRMM began a series of atmospheric CO2 isotope measurements, with the focus on understanding instrumental effects, corrections as well as metrological aspects. The calibration approach at JRC-IRMM is based on use of a plain CO2 sample (working reference CO2) as a calibration carrier and CO2-air mixtures (in high-pressure cylinders) to determine the method-related correction under actual analytical conditions (another calibration carrier, in the same form as the samples). Although this approach differs from that in other laboratories, it does give a direct link to the primary reference NBS-19-CO2. It also helps to investigate the magnitude and nature for each of the instrumental corrections and allows for the quantification of the uncertainty introduced. Critical tests were focused on the instrumental corrections. It was confirmed that the use of non-symmetrical capillary crimping (an approach used here to deal with small samples) systematically modifies delta13C(CO2) and delta18O(CO2), with a clear dependence on the amount of extracted CO2. However, the calibration of CO2-air mixtures required the use of the symmetrical dual-inlet mode. As a proof of our approach, we found that delta13C(CO2) on extracts from mixtures agreed (within 0.010 per thousand) with values obtained from the 'mother' CO2 used for the mixtures. It was further found that very low levels of hydrocarbons in the pumping systems and the isotope ratio mass spectrometry (IRMS) instrument itself were critical. The m/z 46 values (consequently the calculated delta18O(CO2) values) are affected by several other effects with traces of air co-trapped with frozen CO2 being the most critical. A careful cryo-distillation of the extracted CO2 is recommended. After extensive testing, optimisation, and routine automated use, the system was found to give precise data on air samples that can be traced with confidence to the primary standards. The typical total combined uncertainty in delta13C(CO2) and delta18O(CO2) on the VPDB-CO2 scale, estimated on runs of CO2-air mixtures, is +/-0.040 per thousand and 0.060 per thousand (2-sigma values). Inter-comparison with MPI-BGC resulted in a scale discrepancy of a similar magnitude. Although the reason(s) for this discrepancy still need to be understood, this basically confirms the approach of using specifically prepared CO2-air mixtures as a calibration carrier, in order to achieve scale unification among laboratories. As important practical application and as a critical test, JRC-IRMM took part in the passenger aircraft-based global monitoring project CARIBIC (http://www.caribic-atmospheric.com). In this way, reliable CO2 isotope data for the tropopause region and the free troposphere were obtained. From June 2007 to January 2009, approximately 500 CARIBIC air samples have been analysed. Some flights demonstrated a compact correlation of both delta13C(CO2) and delta18O(CO2) with respect to CO2 concentration, demonstrating mixing of tropospheric and stratospheric air masses. These excellent correlations provide an independent, realistic data quality check. Copyright (c) 2009 John Wiley & Sons, Ltd.

Infrequent air contamination with Acinetobacter baumannii of air surrounding known colonized or infected patients.

PubMed

Rock, Clare; Harris, Anthony D; Johnson, J Kristie; Bischoff, Werner E; Thom, Kerri A

2015-07-01

Using a validated air sampling method we found Acinetobacter baumannii in the air surrounding only 1 of 12 patients known to be colonized or infected with A. baumannii. Patients' closed-circuit ventilator status, frequent air exchanges in patient rooms, and short sampling time may have contributed to this low burden.

Molecular comparison of the sampling efficiency of four types of airborne bacterial samplers.

PubMed

Li, Kejun

2011-11-15

In the present study, indoor and outdoor air samples were collected using four types of air samplers often used for airborne bacterial sampling. These air samplers included two solid impactors (BioStage and RCS), one liquid impinger (BioSampler), and one filter sampler with two kinds of filters (a gelatin and a cellulose acetate filter). The collected air samples were further processed to analyze the diversity and abundance of culturable bacteria and total bacteria through standard culture techniques, denaturing gradient gel electrophoresis (DGGE) fingerprinting and quantitative polymerase chain reaction (qPCR) analysis. The DGGE analysis indicated that the air samples collected using the BioStage and RCS samplers have higher culturable bacterial diversity, whereas the samples collected using the BioSampler and the cellulose acetate filter sampler have higher total bacterial diversity. To obtain more information on the sampled bacteria, some gel bands were excised and sequenced. In terms of sampling efficiency, results from the qPCR tests indicated that the collected total bacterial concentration was higher in samples collected using the BioSampler and the cellulose acetate filter sampler. In conclusion, the sampling bias and efficiency of four kinds of air sampling systems were compared in the present study and the two solid impactors were concluded to be comparatively efficient for culturable bacterial sampling, whereas the liquid impactor and the cellulose acetate filter sampler were efficient for total bacterial sampling. Copyright © 2011 Elsevier B.V. All rights reserved.

Air Sampling Logbook of Region 4 Yellow Bluff Air Study Wilcox County, Alabama SESD Project Identification Number:11-0068

EPA Pesticide Factsheets

Contains the Air Sampling Logbook between 1-24-2011 thru 1-28-2011 from the Region 4 Yellow Bluff Air Study Wilcox County, Alabama SESD Project Identification Number:11-0068 November 2010-December 2010

Air Sample Conditioner Helps the Waste Treatment Plant Meet Emissions Standards

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

Glissmeyer, John A.; Flaherty, Julia E.; Pekour, Mikhail S.

2014-12-02

The air in three of the Hanford Site Waste Treatment and Immobilization Plant (WTP) melter off-gas discharge stacks will be hot and humid after passing through the train of emission abatement equipment. The off-gas temperature and humidity levels will be incompatible with the airborne emissions monitoring equipment required for this type of stack. To facilitate sampling from these facilities, an air sample conditioner system will be installed to introduce cool, dry air into the sample stream to reduce the temperature and dew point. This will avoid thermal damage to the instrumentation and problematic condensation. The complete sample transport system mustmore » also deliver at least 50% of the particles in the sample airstream to the sample collection and on-line analysis equipment. The primary components of the sample conditioning system were tested in a laboratory setting. The sample conditioner itself is based on a commercially-available porous tube filter design. It consists of a porous sintered metal tube inside a coaxial metal jacket. The hot gas sample stream passes axially through the porous tube, and the dry, cool air is injected into the jacket and through the porous wall of the inner tube, creating an effective sample diluter. The dilution and sample air mix along the entire length of the porous tube, thereby simultaneously reducing the dew point and temperature of the mixed sample stream. Furthermore, because the dilution air enters through the porous tube wall, the sample stream does not come in contact with the porous wall and particle deposition is reduced in this part of the sampling system. Tests were performed with an environmental chamber to supply air with the temperature and humidity needed to simulate the off-gas conditions. Air from the chamber was passed through the conditioning system to test its ability to reduce the temperature and dew point of the sample stream. To measure particle deposition, oil droplets in the range of 9 to 11 micrometer aerodynamic diameter were injected into the environmental chamber and drawn through the conditioning system, which included a filter to capture droplets that passed through the conditioner. The droplets were tagged with a fluorescent dye which allowed quantification of droplet deposition on each component of the system. The tests demonstrated the required reductions in temperature and moisture, with no condensation forming when heat tracing was added on the upstream end of the sample conditioner. Additionally, tests indicated that the system, operating at several flow rates and in both vertical and horizontal orientations, delivers nearly all of the sampled particles for analysis. Typical aerosol penetration values were between 98 and 99%. PNNL, Bechtel National Inc., and the instrument vendor are working to implement the sample conditioner into the air monitoring systems used for the melter off-gas exhaust streams. Similar technology may be useful for processes in other facilities with air exhaust streams with elevated temperature and/or humidity.« less

Health hazard evaluation report No. HHE-80-233-793, Davis Bessie Nuclear Power Station, Toledo Edison Company, United Engineers and Contractors Company (UE and C), Oak Harbor, Ohio

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

Cone, J.; Hartle, R.

1981-01-01

Personal air samples were analyzed and employees were given medical evaluations at Davis Bessie Nuclear Power Station (SIC-4911) in Oak Harbor, Ohio. Requests for evaluation were made by a union representative of the United Engineers and Contractors and a union representative of employees of Toledo Edison Company, working on site at the power station, to evaluate employee skin and scalp problems due to exposure to ceramic wood fibers. Preliminary surveys were conducted on September 24 and 25, 1980 and a follow-up survey was performed on October 16, 1980. Environmental evaluation consisted of gravimetric analyses of personal air samples for airbornemore » ceramic wool fibers. A total of 400 production and maintenance workers and varying numbers of construction workers were exposed to the fibers during installation of insulation which was completed at the time of the survey. The three personal air samples showed no accumulation of particulates and fibers detected were nonrespirable. Medical evaluations were conducted in 52 workers and scalp scrapings were obtained from 43 workers. Thirty seven workers had histories suggestive of irritant dermatitis of the scalp; 24 workers had physical findings consistent with the diagnosis. Of the 43 scalp samples, 18 were contaminated with organisms of the gut, perineum, skin or respiratory tract. Dermatitis was directly related to the history of dust exposure. The authors conclude that a potential health hazard exists for employees from exposure to ceramic wool fiber. Recommendations include provision of handwashing facilities and protective clothing for employees, and installation of an impermeable covering for the ceramic wool fiber.« less

Ozone reactivity of biogenic volatile organic compound (BVOC) emissions during the Southeast Oxidant and Aerosol Study (SOAS)

NASA Astrophysics Data System (ADS)

Park, J.; Guenther, A. B.; Helmig, D.

2013-12-01

Recent studies on atmospheric chemistry in the forest environment showed that the total reactivity by biogenic volatile organic compound (BVOC) emission is still not well understood. During summer 2013, an intensive field campaign (Southeast Oxidant and Aerosol Study - SOAS) took place in Alabama, U.S.A. In this study, an ozone reactivity measurement system (ORMS) was deployed for the direct determination of the reactivity of foliage emissions. The ORMS is a newly developed measurement approach, in which a known amount of ozone is added to the ozone-free air sample stream, with the ORMS measuring ozone concentration difference between before and after a glass flask flow tube reaction vessel (2-3 minutes of residence time). Emissions were also collected onto adsorbent cartridges to investigate the discrepancy between total ozone reactivity observation and reactivity calculated from identified BVOC. Leaf and canopy level experiments were conducted by deploying branch enclosures on the three dominant tree species at the site (i.e. liquidambar, white oak, loblolly pine) and by sampling ambient air above the forest canopy. For the branch enclosure experiments, BVOC emissions were sampled from a 70 L Teflon bag enclosure, purged with air scrubbed for ozone, nitrogen oxides. Each branch experiment was performed for 3-5 days to collect at least two full diurnal cycle data. In addition, BVOCs were sampled using glass tube cartridges for 2 hours during daytime and 3 - 4 hours at night. During the last week of campaign, the inlet for the ORMS was installed on the top of scaffolding tower (~30m height). The ozone loss in the reactor showed distinct diurnal cycle for all three tree species investigated, and ozone reactivity followed patterns of temperature and light intensity.

14CO2 dispersion around two PWR nuclear power plants in Brazil.

PubMed

Dias, Cíntia Melazo; Stenström, Kristina; Bacelar Leão, Igor Luiz; Santos, Roberto Ventura; Nícoli, Iêda Gomes; Skog, Göran; Ekström, Peter; da Silveira Corrêa, Rosangela

2009-07-01

Atmospheric air samples were taken within 3 km from power plants encompassing five different distances and wind directions. Samples were taken between 2002 and 2005 aiming to evaluate the environmental (14)C enrichment due to the operation of Brazilian nuclear power plants. The sampling system consisted of a pump connected to a trapping column filled with a 3M NaOH solution. The trapped CO(2) was analyzed for (14)C by using a single stage accelerator mass spectrometry (SSAMS). All sampling sites revealed measurable (14)C excess values. The maximum excesses were of 15 and 14 mBq/m(3) for sampling sites placed at NE of the power plants, which is the main wind direction in the area. The mean excesses values were 12 mBq/m(3) to the NE direction, 8 mBq/m(3) to the E, 10 mBq/m(3) to the N, 8 mBq/m(3) to the WNW and 7 mBq/m(3) to the W direction (increasing distances from NE to W). Compared to other Light Water Reactors (LWR) data, these means' values are significantly higher than the average worldwide reported value of 3 mBq/m(3). Available data indicate that the observed values are not related to (14)C emission by the power plants vent stack. Other factors, such as topography, seem to have an important role because it affects wind dispersion thus favoring (14)C accumulation in the sampled area. Moreover, the high elevations around the power plants enhance the chances to measure high values of (14)C since the plume can be intercepted before it is drawn to the ground. Modeling of the plume has shown that its dispersion does not follow a Gaussian model and that agreement between atmospheric CO(2) and vegetation (14)C activities occurs only for sampling sites placed at NE of the power plants.

Fuel-Air Injection Effects on Combustion in Cavity-Based Flameholders in a Supersonic Flow

DTIC Science & Technology

2005-03-01

both fuel and air provided additional capability to tune the cavity such that a more stable decentralized flame results. The addition of air...Mark Gruber of AFRL/PRAS and Mr. Mark Hsu of Innovative Scientific Solutions Inc. for both the support and latitude provided to me in this endeavor...addition of direct air injection to cavity combustion. Direct injection of both fuel and air provided additional capability to tune the cavity such that a

Optical second harmonic generation from V-shaped chromium nanohole arrays

NASA Astrophysics Data System (ADS)

Khoa Quang, Ngo; Miyauchi, Yoshihiro; Mizutani, Goro; Charlton, Martin D.; Chen, Ruiqi; Boden, Stuart; Rutt, Harvey

2014-02-01

We observed rotational anisotropy of optical second harmonic generation (SHG) from an array of V-shaped chromium nanoholes fabricated by electron beam lithography. Phenomenological analysis indicated that the effective nonlinear susceptibility element \\chi _{313}^{(2)} had a characteristic contribution to the observed anisotropic SHG intensity patterns. Here, coordinate 1 is in the direction of the tip of V shapes in the substrate plane, and 3 indicates the direction perpendicular to the sample surface. The SHG intensity for the S-polarized output light was very weak, probably owing to the cancellation effect of the image dipoles generated at the metal-air boundary. The possible origin of the observed nonlinearity is discussed in terms of the susceptibility elements obtained.

Fungal Communities Including Plant Pathogens in Near Surface Air Are Similar across Northwestern Europe.

PubMed

Nicolaisen, Mogens; West, Jonathan S; Sapkota, Rumakanta; Canning, Gail G M; Schoen, Cor; Justesen, Annemarie F

2017-01-01

Information on the diversity of fungal spores in air is limited, and also the content of airborne spores of fungal plant pathogens is understudied. In the present study, a total of 152 air samples were taken from rooftops at urban settings in Slagelse, DK, Wageningen NL, and Rothamsted, UK together with 41 samples from above oilseed rape fields in Rothamsted. Samples were taken during 10-day periods in spring and autumn, each sample representing 1 day of sampling. The fungal content of samples was analyzed by metabarcoding of the fungal internal transcribed sequence 1 (ITS1) and by qPCR for specific fungi. The metabarcoding results demonstrated that season had significant effects on airborne fungal communities. In contrast, location did not have strong effects on the communities, even though locations were separated by up to 900 km. Also, a number of plant pathogens had strikingly similar patterns of abundance at the three locations. Rooftop samples were more diverse than samples taken above fields, probably reflecting greater mixing of air from a range of microenvironments for the rooftop sites. Pathogens that were known to be present in the crop were also found in air samples taken above the field. This paper is one of the first detailed studies of fungal composition in air with the focus on plant pathogens and shows that it is possible to detect a range of pathogens in rooftop air samplers using metabarcoding.

14 CFR 212.7 - Direct sales.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

14 CFR 212.7 - Direct sales.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 4 2012-01-01 2012-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

14 CFR 212.7 - Direct sales.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

14 CFR 212.7 - Direct sales.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

14 CFR 212.7 - Direct sales.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Direct sales. 212.7 Section 212.7... REGULATIONS CHARTER RULES FOR U.S. AND FOREIGN DIRECT AIR CARRIERS § 212.7 Direct sales. (a) Certificated and foreign air carriers may sell or offer for sale, and operate, as principal, Public Charter flights under...

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.

Using Arduinos and 3D-printers to Build Research-grade Weather Stations and Environmental Sensors

NASA Astrophysics Data System (ADS)

Ham, J. M.

2013-12-01

Many plant, soil, and surface-boundary-layer processes in the geosphere are governed by the microclimate at the land-air interface. Environmental monitoring is needed at smaller scales and higher frequencies than provided by existing weather monitoring networks. The objective of this project was to design, prototype, and test a research-grade weather station that is based on open-source hardware/software and off-the-shelf components. The idea is that anyone could make these systems with only elementary skills in fabrication and electronics. The first prototypes included measurements of air temperature, humidity, pressure, global irradiance, wind speed, and wind direction. The best approach for measuring precipitation is still being investigated. The data acquisition system was deigned around the Arduino microcontroller and included an LCD-based user interface, SD card data storage, and solar power. Sensors were sampled at 5 s intervals and means, standard deviations, and maximum/minimums were stored at user-defined intervals (5, 30, or 60 min). Several of the sensor components were printed in plastic using a hobby-grade 3D printer (e.g., RepRap Project). Both passive and aspirated radiation shields for measuring air temperature were printed in white Acrylonitrile Butadiene Styrene (ABS). A housing for measuring solar irradiance using a photodiode-based pyranometer was printed in opaque ABS. The prototype weather station was co-deployed with commercial research-grade instruments at an agriculture research unit near Fort Collins, Colorado, USA. Excellent agreement was found between Arduino-based system and commercial weather instruments. The technology was also used to support air quality research and automated air sampling. The next step is to incorporate remote access and station-to-station networking using Wi-Fi, cellular phone, and radio communications (e.g., Xbee).

Determination of heavy metals concentrations in airborne particulates matter (APM) from Manjung district, Perak using energy dispersive X-ray fluorescence (EDXRF) spectrometer

NASA Astrophysics Data System (ADS)

Arshad, Nursyairah; Hamzah, Zaini; Wood, Ab. Khalik; Saat, Ahmad; Alias, Masitah

2015-04-01

Airborne particulates trace metals are considered as public health concern as it can enter human lungs through respiratory system. Generally, any substance that has been introduced to the atmosphere that can cause severe effects to living things and the environment is considered air pollution. Manjung, Perak is one of the development districts that is active with industrial activities. There are many industrial activities surrounding Manjung District area such as coal fired power plant, quarries and iron smelting which may contribute to the air pollution into the environment. This study was done to measure the concentrations of Hg, U, Th, K, Cu, Fe, Cr, Zn, As, Se, Pb and Cd in the Airborne Particulate Matter (APM) collected at nine locations in Manjung District area within 15 km radius towards three directions (North, North-East and South-East) in 5 km intervals. The samples were collected using mini volume air sampler with cellulose filter through total suspended particulate (TSP). The sampler was set up for eight hours with the flow rate of 5 L/min. The filter was weighed before and after sample collection using microbalance, to get the amount of APM and kept in desiccator before analyzing. The measurement was done using calibrated Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer. The air particulate concentrations were found below the Malaysia Air Quality Guidelines for TSP (260 µg/m3). All of the metals concentrations were also lower than the guidelines set by World Health Organization (WHO), Ontario Ministry of the Environment and Argonne National Laboratory, USA NCRP (1975). From the concentrations, the enrichment factor were calculated.

Air sampling with solid phase microextraction

NASA Astrophysics Data System (ADS)

Martos, Perry Anthony

There is an increasing need for simple yet accurate air sampling methods. The acceptance of new air sampling methods requires compatibility with conventional chromatographic equipment, and the new methods have to be environmentally friendly, simple to use, yet with equal, or better, detection limits, accuracy and precision than standard methods. Solid phase microextraction (SPME) satisfies the conditions for new air sampling methods. Analyte detection limits, accuracy and precision of analysis with SPME are typically better than with any conventional air sampling methods. Yet, air sampling with SPME requires no pumps, solvents, is re-usable, extremely simple to use, is completely compatible with current chromatographic equipment, and requires a small capital investment. The first SPME fiber coating used in this study was poly(dimethylsiloxane) (PDMS), a hydrophobic liquid film, to sample a large range of airborne hydrocarbons such as benzene and octane. Quantification without an external calibration procedure is possible with this coating. Well understood are the physical and chemical properties of this coating, which are quite similar to those of the siloxane stationary phase used in capillary columns. The log of analyte distribution coefficients for PDMS are linearly related to chromatographic retention indices and to the inverse of temperature. Therefore, the actual chromatogram from the analysis of the PDMS air sampler will yield the calibration parameters which are used to quantify unknown airborne analyte concentrations (ppb v to ppm v range). The second fiber coating used in this study was PDMS/divinyl benzene (PDMS/DVB) onto which o-(2,3,4,5,6- pentafluorobenzyl) hydroxylamine (PFBHA) was adsorbed for the on-fiber derivatization of gaseous formaldehyde (ppb v range), with and without external calibration. The oxime formed from the reaction can be detected with conventional gas chromatographic detectors. Typical grab sampling times were as small as 5 seconds. With 300 seconds sampling, the formaldehyde detection limit was 2.1 ppbv, better than any other 5 minute sampling device for formaldehyde. The first-order rate constant for product formation was used to quantify formaldehyde concentrations without a calibration curve. This spot sampler was used to sample the headspace of hair gel, particle board, plant material and coffee grounds for formaldehyde, and other carbonyl compounds, with extremely promising results. The SPME sampling devices were also used for time- weighted average sampling (30 minutes to 16 hours). Finally, the four new SPME air sampling methods were field tested with side-by-side comparisons to standard air sampling methods, showing a tremendous use of SPME as an air sampler.

Air, hand wipe, and surface wipe sampling for Bisphenol A (BPA) among workers in industries that manufacture and use BPA in the United States.

PubMed

Hines, Cynthia J; Jackson, Matthew V; Christianson, Annette L; Clark, John C; Arnold, James E; Pretty, Jack R; Deddens, James A

2017-11-01

For decades, bisphenol A (BPA) has been used in making polycarbonate, epoxy, and phenolic resins and certain investment casting waxes, yet published exposure data are lacking for U.S. manufacturing workers. In 2013-2014, BPA air and hand exposures were quantified for 78 workers at six U.S. companies making BPA or BPA-based products. Exposure measures included an inhalable-fraction personal air sample on each of two consecutive work days (n = 146), pre- and end-shift hand wipe samples on the second day (n = 74 each), and surface wipe samples (n = 88). Potential determinants of BPA air and end-shift hand exposures (after natural log transformation) were assessed in univariate and multiple regression mixed models. The geometric mean (GM) BPA air concentration was 4.0 µg/m 3 (maximum 920 µg/m 3 ). The end-shift GM BPA hand level (26 µg/sample) was 10-times higher than the pre-shift level (2.6 µg/sample). BPA air and hand exposures differed significantly by industry and job. BPA air concentrations and end-shift hand levels were highest in the BPA-filled wax manufacturing/reclaim industry (GM Air = 48 µg/m 3 , GM Hand-End = 130 µg/sample) and in the job of working with molten BPA-filled wax (GM Air = 43 µg/m 3 , GM Hand-End = 180 µg/sample), and lowest in the phenolic resins industry (GM Air = 0.85 µg/m 3 , GM Hand-End = 0.43 µg/sample) and in the job of flaking phenolic resins (GM AIR = 0.62 µg/m 3 , GM Hand-End = 0.38 µg/sample). Determinants of increased BPA air concentration were industry, handling BPA containers, spilling BPA, and spending ≥50% of the shift in production areas; increasing age was associated with lower air concentrations. BPA hand exposure determinants were influenced by high values for two workers; for all other workers, tasks involving contact with BPA-containing materials and spending ≥50% of the shift in production areas were associated with increased BPA hand levels. Surface wipe BPA levels were significantly lower in eating/office areas (GM = 9.3 µg/100 cm 2 ) than in production areas (GM = 140 µg/100 cm 2 ). In conclusion, worker BPA exposure was associated with tasks and conditions affecting both inhalation and dermal exposure. The potential for BPA-related health effects among these workers is unknown.

A BATTERY-OPERATED AIR SAMPLER FOR REMOTE AREAS

EPA Science Inventory

An air sampling system developed to evaluate air quality in biosphere reserves or in other remote areas is described. The equipment consists of a Dupont P-4000 pump and a specially designed battery pack containing Gates batteries. This air sampling system was tested in Southern U...

Direct measurement of air kerma rate in air from CDCS J-type caesium-137 therapy sources using a Farmer ionization chamber.

PubMed

Poynter, A J

2000-04-01

A simple method for directly measuring the reference air kerma rate from J-type 137Cs sources using a Farmer 2571 chamber has been evaluated. The method is useful as an independent means of verifying manufacturers' test data.

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2012 CFR

2012-07-01

... vested in the Real Property Division, Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers may issue Real Estate Directives for acquisitions not... Air Force Regional Civil Engineers. The numbers will be in a consecutive series for each Division and...

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2014 CFR

2014-07-01

... vested in the Real Property Division, Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers may issue Real Estate Directives for acquisitions not... Air Force Regional Civil Engineers. The numbers will be in a consecutive series for each Division and...

32 CFR 644.27 - Authority to issue Real Estate Directives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... vested in the Real Property Division, Directorate of Engineering and Services, HQ, USAF. Major Air Commands and Air Force Regional Civil Engineers may issue Real Estate Directives for acquisitions not... Air Force Regional Civil Engineers. The numbers will be in a consecutive series for each Division and...

30 CFR 75.341 - Direct-fired intake air heaters.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 75.341 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY SAFETY STANDARDS-UNDERGROUND COAL MINES Ventilation § 75.341 Direct-fired intake air heaters. (a) If any system used to heat intake air malfunctions, the heaters affected shall switch...

Occurrence and Spatial and Temporal Variations of Disinfection By-Products in the Water and Air of Two Indoor Swimming Pools

PubMed Central

Catto, Cyril; Sabrina, Simard; Ginette, Charest-Tardif; Manuel, Rodriguez; Robert, Tardif

2012-01-01

In order to improve disinfection by-product (DBP) exposure assessment, this study was designed to document both water and air levels of these chemical contaminants in two indoor swimming pools and to analyze their within-day and day-to-day variations in both of them. Intensive sampling was carried out during two one-week campaigns to measure trihalomethanes (THMs) and chloramines (CAMs) in water and air, and haloacetic acids (HAAs) in water several times daily. Water samples were systematically collected at three locations in each pool and air samples were collected at various heights around the pool and in other rooms (e.g., changing room) in the buildings. In addition, the ability of various models to predict air concentrations from water was tested using this database. No clear trends, but actual variations of contamination levels, appeared for both water and air according to the sampling locations and times. Likewise, the available models resulted in realistic but imprecise estimates of air contamination levels from water. This study supports the recommendation that suitable minimal air and water sampling should be carried out in swimming pools to assess exposure to DBPs. PMID:23066383

Passive Sampling for Indoor and Outdoor Exposures to Chlorpyrifos, Azinphos-Methyl, and Oxygen Analogs in a Rural Agricultural Community

PubMed Central

Gibbs, Jenna L.; Yost, Michael G.; Negrete, Maria; Fenske, Richard A.

2016-01-01

Background: Recent studies have highlighted the increased potency of oxygen analogs of organophosphorus pesticides. These pesticides and oxygen analogs have previously been identified in the atmosphere following spray applications in the states of California and Washington. Objectives: We used two passive sampling methods to measure levels of the ollowing organophosphorus pesticides: chlorpyrifos, azinphos-methyl, and their oxygen analogs at 14 farmworker and 9 non-farmworker households in an agricultural region of central Washington State in 2011. Methods: The passive methods included polyurethane foam passive air samplers deployed outdoors and indoors and polypropylene deposition plates deployed indoors. We collected cumulative monthly samples during the pesticide application seasons and during the winter season as a control. Results: Monthly outdoor air concentrations ranged from 9.2 to 199 ng/m3 for chlorpyrifos, 0.03 to 20 ng/m3 for chlorpyrifos-oxon, < LOD (limit of detection) to 7.3 ng/m3 for azinphos-methyl, and < LOD to 0.8 ng/m3 for azinphos-methyl-oxon. Samples from proximal households (≤ 250 m) had significantly higher outdoor air concentrations of chlorpyrifos, chlorpyrifos-oxon, and azinphos-methyl than did samples from nonproximal households (p ≤ 0.02). Overall, indoor air concentrations were lower than outdoors. For example, all outdoor air samples for chlorpyrifos and 97% of samples for azinphos-methyl were > LOD. Indoors, only 78% of air samples for chlorpyrifos and 35% of samples for azinphos-methyl were > LOD. Samples from farmworker households had higher indoor air concentrations of both pesticides than did samples from non-farmworker households. Mean indoor and outdoor air concentration ratios for chlorpyrifos and azinphos-methyl were 0.17 and 0.44, respectively. Conclusions: We identified higher levels in air and on surfaces at both proximal and farmworker households. Our findings further confirm the presence of pesticides and their oxygen analogs in air and highlight their potential for infiltration of indoor living environments. Citation: Gibbs JL, Yost MG, Negrete M, Fenske RA. 2017. Passive sampling for indoor and outdoor exposures to chlorpyrifos, azinphos-methyl, and oxygen analogs in a rural agricultural community. Environ Health Perspect 125:333–341; http://dx.doi.org/10.1289/EHP425 PMID:27517732

Influential role of black carbon in the soil-air partitioning of polychlorinated biphenyls (PCBs) in the Indus River Basin, Pakistan.

PubMed

Ali, Usman; Syed, Jabir Hussain; Mahmood, Adeel; Li, Jun; Zhang, Gan; Jones, Kevin C; Malik, Riffat Naseem

2015-09-01

Levels of polychlorinated biphenyls (PCBs) were assessed in surface soils and passive air samples from the Indus River Basin, and the influential role of black carbon (BC) in the soil-air partitioning process was examined. ∑26-PCBs ranged between 0.002-3.03 pg m(-3) and 0.26-1.89 ng g(-1) for passive air and soil samples, respectively. Lower chlorinated (tri- and tetra-) PCBs were abundant in both air (83.9%) and soil (92.1%) samples. Soil-air partitioning of PCBs was investigated through octanol-air partition coefficients (KOA) and black carbon-air partition coefficients (KBC-A). The results of the paired-t test revealed that both models showed statistically significant agreement between measured and predicted model values for the PCB congeners. Ratios of fBCKBC-AδOCT/fOMKOA>5 explicitly suggested the influential role of black carbon in the retention and soil-air partitioning of PCBs. Lower chlorinated PCBs were strongly adsorbed and retained by black carbon during soil-air partitioning because of their dominance at the sampling sites and planarity effect. Copyright © 2015 Elsevier Ltd. All rights reserved.

Partitioned airs at microscale and nanoscale: thermal diffusivity in ultrahigh porosity solids of nanocellulose

PubMed Central

Sakai, Koh; Kobayashi, Yuri; Saito, Tsuguyuki; Isogai, Akira

2016-01-01

High porosity solids, such as plastic foams and aerogels, are thermally insulating. Their insulation performance strongly depends on their pore structure, which dictates the heat transfer process in the material. Understanding such a relationship is essential to realizing highly efficient thermal insulators. Herein, we compare the heat transfer properties of foams and aerogels that have very high porosities (97.3–99.7%) and an identical composition (nanocellulose). The foams feature rather closed, microscale pores formed with a thin film-like solid phase, whereas the aerogels feature nanoscale open pores formed with a nanofibrous network-like solid skeleton. Unlike the aerogel samples, the thermal diffusivity of the foam decreases considerably with a slight increase in the solid fraction. The results indicate that for suppressing the thermal diffusion of air within high porosity solids, creating microscale spaces with distinct partitions is more effective than directly blocking the free path of air molecules at the nanoscale. PMID:26830144

Project management plan for asbestos control at Randolph Air Force Base

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

Broers, G.J.

1988-02-01

The United States Air Force Air Training Command (ATC) Headquarters requested assistance from the Idaho National Engineering Laboratory (INEL) in February, 1987 to develop processes and procedures and provide program management to minimize and control asbestos hazard at its thirteen bases. This effort was requested by the ATC to comply with Executive Order 12088 under which the USAF is directed to meet all applicable federal, state, and local environmental regulations. In response to that request the efforts identified within this document provide the ATC with a thorough base-wide Asbestos Survey Report, an Asbestos Management Plan and an Operations and Maintenancemore » Plan for Randolph AFB which, when implemented, will comply with current and anticipated federal laws and provide the base with accurate information needed for long range asbestos management. The other twelve bases will be surveyed and sampled in the four years to follow with appropriate asbestos management plans developed for each. 6 figs.« less

Production and Optimization of Direct Coal Liquefaction derived Low Carbon-Footprint Transportation Fuels

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

Steven Markovich

This report summarizes works conducted under DOE Contract No. DE-FC26-05NT42448. The work scope was divided into two categories - (a) experimental program to pretreat and refine a coal derived syncrude sample to meet transportation fuels requirements; (b) system analysis of a commercial scale direct coal liquefaction facility. The coal syncrude was derived from a bituminous coal by Headwaters CTL, while the refining study was carried out under a subcontract to Axens North America. The system analysis included H{sub 2} production cost via six different options, conceptual process design, utilities requirements, CO{sub 2} emission and overall plant economy. As part ofmore » the system analysis, impact of various H{sub 2} production options was evaluated. For consistence the comparison was carried out using the DOE H2A model. However, assumptions in the model were updated using Headwaters database. Results of Tier 2 jet fuel specifications evaluation by the Fuels & Energy Branch, US Air Force Research Laboratory (AFRL/RZPF) located at Wright Patterson Air Force Base (Ohio) are also discussed in this report.« less

Department of Defense Dictionary of Military and Associated Terms

DTIC Science & Technology

2016-02-15

05) active air defense — Direct defensive action taken to destroy, nullify, or reduce the effectiveness of hostile air and missile threats against...JP 3-60) air and missile defense — Direct [active and passive] defensive actions taken to destroy, nullify, or reduce the effectiveness of...troops especially trained to effect , following transport by air, an assault debarkation, either by parachuting or touchdown. 2. In relation to

Underground anemotactic orientation in leaf-cutting ants: perception of airflow and experience-dependent choice of airflow direction during digging

NASA Astrophysics Data System (ADS)

Halboth, Florian; Roces, Flavio

2017-10-01

Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.

Underground anemotactic orientation in leaf-cutting ants: perception of airflow and experience-dependent choice of airflow direction during digging.

PubMed

Halboth, Florian; Roces, Flavio

2017-09-19

Air exchange between the large nests of Atta vollenweideri leaf-cutting ants and the environment strongly relies on a passive, wind-induced ventilation mechanism. Air moves through nest tunnels and airflow direction depends on the location of the tunnel openings on the nest mound. We hypothesized that ants might use the direction of airflow along nest tunnels as orientation cue in the context of climate control, as digging workers might prefer to broaden or to close tunnels with inflowing or outflowing air in order to regulate nest ventilation. To investigate anemotactic orientation in Atta vollenweideri, we first tested the ants' ability to perceive air movements by confronting single workers with airflow stimuli in the range 0 to 20 cm/s. Workers responded to airflow velocities ≥ 2 cm/s, and the number of ants reacting to the stimulus increased with increasing airflow speed. Second, we asked whether digging workers use airflow direction as an orientation cue. Workers were exposed to either inflow or outflow of air while digging in the nest and could subsequently choose between two digging sites providing either inflow or outflow of air, respectively. Workers significantly chose the side with the same airflow direction they experienced before. When no airflow was present during initial digging, workers showed no preference for airflow directions. Workers developed preferences for airflow direction only after previous exposure to a given airflow direction. We suggest that experience-modified anemotaxis might help leaf-cutting ants spatially organize their digging activity inside the nest during tasks related to climate control.

O-Chlorobenzylidene Malononitrile (CS Riot Control Agent) Exposures and Associated Acute Respiratory Illnesses in a United States Army Basic Combat Training Cohort

DTIC Science & Technology

2014-03-14

Biometrika 52:591-611 66. Shmunes E, Taylor J. 1973. Industrial Contact Dermatitis . Arch Dermatol 107:212-6 67. Sivathasn N. 2010. Educating on CS...including those associated with ARI) have been shown to spread via direct and indirect contact and to commonly 1 occur following chemical irritation...advises that when a chemical bears a skin notation, 39 measures should be taken to prevent dermal contact because air sampling does not account for

Development, Validation, and Deployment of a Revised Air Traffic Control Color Vision Test: Incorporating Advanced Technologies and Oceanic Procedures and En Route Automation Modernization Systems

DTIC Science & Technology

2013-09-01

through direct sampling of form and content of critical display data. Evidence of construct validity is provided by correlation with the Colour ...measured by the Colour Assessment and Diagnosis (CAD; ARTS Background Colors STARS Background Colors ERAM Background Colors Figure 3...Gelade, G. (1980). A feature-integration theory of attention. Cognitive Psychology , 12, 97–136. Xing, J. & Schroeder, D.J. (2006). Reexamination of

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.

A Synoptic Climatology of the Elevated Mixed Layer Inversion Over the Southern Great Plains in Spring

DTIC Science & Technology

1991-08-01

offshore PBL flow along Texas coast at initial time (1200 UTC 4 April). Tick marks along the trajectory are used to denote the simulation hour; the...are taken at tornado Gulf Coast event time at closest upper- air station in an upstream direction with respect to mean low-level flow ). All rain... system starts (subdivided by time of day). A sample day was also discussed. 9 break and thermal inversion layer appears. Above the inversion layer

Low coke fuel injector for a gas turbine engine

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

Taylor, J.R.

This patent describes a gas turbine carbureting device for disposal in a down-stream flowing compressor discharge air flow. It comprises: a spin chamber defined by a generally annular housing including a closed forward end having a continuous unobstructed inner surface and an open aft end wherein the forward end is upstream of the aft end with respect tot he compressor discharge airflow; at least one exhaust tube having an inlet disposed within the spin chamber wherein the exhaust tube is radially spaced apart from the annular housing and which together with the annular housing forms at least in part amore » first annular air passage leading to the forward end; the housing having a fuel entrance and a swirling air entrance to the first annular air passage and spaced axially apart from each other, and wherein the swirling air entrance and fuel entrance are downstream of the closer forward end with respect to the compressor discharge flow; and wherein the first air passage is formed for flowing swirling air from the swirling air passage to the aft end in an upstream direction with respect to the compressor discharge flow and the exhaust tube inlet is disposed within the swirl chamber so as to reverse the axial direction of the swirling air off the forward end from an upstream direction to a downstream direction through the exhaust tube.« less

Comparison of Passive and Active Air Sampling (PAAS) Methods for PCBs – A Pilot Study in New York City Schools

EPA Science Inventory

PCBs were used extensively in school building materials (caulk and lighting fixture ballasts) during the approximate period of 1950-1978. Most of the schools built nationwide during this period have not had indoor air sampling conducted for PCBs. Passive air sampling holds promi...

CTEPP STANDARD OPERATING PROCEDURE FOR COLLECTION OF FIXED SITE INDOOR AND OUTDOOR AIR SAMPLES FOR PERSISTENT ORGANIC POLLUTANTS (SOP-2.12)

EPA Science Inventory

This SOP describes the procedures to set up, calibrate, initiate and terminate air sampling for persistent organic pollutants. This method is used to sample air, indoors and outdoors, at homes and at day care centers over a 48-hr period.

24-HOUR DIFFUSIVE SAMPLING OF TOXIC VOCS IN AIR ONTO CARBOPACK X SOLID ADSORBENT FOLLOWED BY THERMAL DESORPTION/GC/MS ANALYSIS - LABORATORY STUDIES

EPA Science Inventory

Diffusive sampling of a mixture of 42 volatile organic compounds (VOCs) in humidified, purified air onto the solid adsorbent Carbopack X was evaluated under controlled laboratory conditions. The evaluation included variations in sample air temperature, relative humidity, and ozon...

NHEXAS PHASE I MARYLAND STUDY--PAHS IN AIR ANALYTICAL RESULTS

EPA Science Inventory

The PAHs in Air data set contains analytical results for measurements of up to 11 PAHs in 127 air samples over 51 households. Twenty-four-hour samples were taken over a one-week period using a continuous pump and solenoid apparatus pumping a standardized air volume through an UR...

NHEXAS PHASE I MARYLAND STUDY--METALS IN AIR ANALYTICAL RESULTS

EPA Science Inventory

The Metals in Air data set contains analytical results for measurements of up to 4 metals in 458 air samples over 79 households. Twenty-four-hour samples were taken over a one-week period using a continuous pump and solenoid apparatus by pumping a standardized air volume through...

NHEXAS PHASE I MARYLAND STUDY--PESTICIDES IN AIR ANALYTICAL RESULTS

EPA Science Inventory

The Pesticides in Air data set contains analytical results for measurements of up to 9 pesticides in 127 air samples over 51 households. Samples were taken by pumping standardized air volumes through URG impactors with a 10 um cutpoint and polyurethane foam (PUF) filters at indo...

Effect of Air and Vacuum Storage on the Tensile Properties of X-Ray Exposed Aluminized-FEP

NASA Technical Reports Server (NTRS)

deGroh, Kim K.; Gummow, Jonathan D.

2000-01-01

Metallized Teflon(Registered Trademark) FEP (fluorinated ethylene propylene), a common spacecraft thermal control material, from the exterior layer of the Hubble Space Telescope (HST) has become embrittled and suffers from extensive cracking. Teflon samples retrieved during Hubble servicing missions and from the Long Duration Exposure Facility (LDEF) indicate that there may be continued degradation in tensile properties over time. An investigation has been conducted to evaluate the effect of air and vacuum storage on the mechanical properties of x-ray exposed FEP. Aluminized-FEP (Al-FEP) tensile samples were irradiated with 15.3 kV Cu x-rays and stored in air or under vacuum for various time periods. Tensile data indicate that samples stored in air display larger decreases in tensile properties than for samples stored under vacuum. Air-stored samples developed a hazy appearance, which corresponded to a roughening of the aluminized surface. Optical property changes were also characterized. These findings indicate that air exposure plays a role in the degradation of irradiated FEP, therefore proper sample handling and storage is necessary with materials retrieved from space.

Transboundary Air-Pollution Transport in the Czech-Polish Border Region between the Cities of Ostrava and Katowice.

PubMed

Černikovský, Libor; Krejčí, Blanka; Blažek, Zdeněk; Volná, Vladimíra

2016-12-01

The Czech Hydrometeorological Institute (CHMI) estimated the transboundary transport of air pollution between the Czech Republic and Poland by assessing relationships between weather conditions and air pollution in the area as part of the "Air Quality Information System in the Polish-Czech border of the Silesian and Moravian-Silesian region" project (http://www.air-silesia.eu). Estimation of cross-border transport of pollutants is important for Czech-Polish negotiations and targeted measures for improving air quality. Direct measurement of PM 10 and sulphur dioxide (SO 2 ) concentrations and the direction and wind speed from measuring stations in the vicinity of the Czech-Polish state border in 2006-2012. Taking into account all the inaccuracies, simplifications and uncertainties, by which all of the measurements are affected, it is possible to state that the PM 10 transboundary transport was greater from the direction of Poland to the Czech Republic, rather than the other way around. Nevertheless, the highest share of the overall PM 10 concentration load was recorded on days with a vaguely estimated airflow direction. This usually included days with changing wind direction or days with a distinct wind change throughout the given day. A changeable wind is most common during low wind speeds. It can be assumed that during such days with an ambiguous daily airflow, the polluted air saturated with sources on both sides of the border moves from one country to the other. Therefore, we could roughly ascribe an equal level of these concentrations to both the Czech and Polish side. PM 10 transboundary transport was higher from Poland to the Czech Republic than from the opposite direction, despite the predominant air flow from the Czech Republic to Poland. Copyright© by the National Institute of Public Health, Prague 2016

Meteorology drives ambient air quality in a valley: a case of Sukinda chromite mine, one among the ten most polluted areas in the world.

PubMed

Mishra, Soumya Ranjan; Pradhan, Rudra Pratap; Prusty, B Anjan Kumar; Sahu, Sanjat Kumar

2016-07-01

The ambient air quality (AAQ) assessment was undertaken in Sukinda Valley, the chromite hub of India. The possible correlations of meteorological variables with different air quality parameters (PM10, PM2.5, SO2, NO2 and CO) were examined. Being the fourth most polluted area in the globe, Sukinda Valley has always been under attention of researchers, for hexavalent chromium contamination of water. The monitoring was carried out from December 2013 through May 2014 at six strategic locations in the residential and commercial areas around the mining cluster of Sukinda Valley considering the guidelines of Central Pollution Control Board (CPCB). In addition, meteorological parameters viz., temperature, relative humidity, wind speed, wind direction and rainfall, were also monitored. The air quality data were subjected to a general linear model (GLM) coupled with one-way analysis of variance (ANOVA) test for testing the significant difference in the concentration of various parameters among seasons and stations. Further, a two-tailed Pearson's correlation test helped in understanding the influence of meteorological parameters on dispersion of pollutants in the area. All the monitored air quality parameters varied significantly among the monitoring stations suggesting (i) the distance of sampling location to the mine site and other allied activities, (ii) landscape features and topography and (iii) meteorological parameters to be the forcing functions. The area was highly polluted with particulate matters, and in most of the cases, the PM level exceeded the National Ambient Air Quality Standards (NAAQS). The meteorological parameters seemed to play a major role in the dispersion of pollutants around the mine clusters. The role of wind direction, wind speed and temperature was apparent in dispersion of the particulate matters from their source of generation to the surrounding residential and commercial areas of the mine.

Hydrodebridement of wounds: effectiveness in reducing wound bacterial contamination and potential for air bacterial contamination.

PubMed

Bowling, Frank L; Stickings, Daryl S; Edwards-Jones, Valerie; Armstrong, David G; Boulton, Andrew Jm

2009-05-08

The purpose of this study was to assess the level of air contamination with bacteria after surgical hydrodebridement and to determine the effectiveness of hydro surgery on bacterial reduction of a simulated infected wound. Four porcine samples were scored then infected with a broth culture containing a variety of organisms and incubated at 37 degrees C for 24 hours. The infected samples were then debrided with the hydro surgery tool (Versajet, Smith and Nephew, Largo, Florida, USA). Samples were taken for microbiology, histology and scanning electron microscopy pre-infection, post infection and post debridement. Air bacterial contamination was evaluated before, during and after debridement by using active and passive methods; for active sampling the SAS-Super 90 air sampler was used, for passive sampling settle plates were located at set distances around the clinic room. There was no statistically significant reduction in bacterial contamination of the porcine samples post hydrodebridement. Analysis of the passive sampling showed a significant (p < 0.001) increase in microbial counts post hydrodebridement. Levels ranging from 950 colony forming units per meter cubed (CFUs/m3) to 16780 CFUs/m3 were observed with active sampling of the air whilst using hydro surgery equipment compared with a basal count of 582 CFUs/m3. During removal of the wound dressing, a significant increase was observed relative to basal counts (p < 0.05). Microbial load of the air samples was still significantly raised 1 hour post-therapy. The results suggest a significant increase in bacterial air contamination both by active sampling and passive sampling. We believe that action might be taken to mitigate fallout in the settings in which this technique is used.

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.

14 CFR 205.2 - Applicability.

Code of Federal Regulations, 2011 CFR

2011-01-01

... air carriers, including commuter air carriers and air taxi operators as defined in § 298.2 of this chapter, and foreign direct air carriers, including Canadian charter air taxi operators as defined in...

14 CFR 205.2 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... air carriers, including commuter air carriers and air taxi operators as defined in § 298.2 of this chapter, and foreign direct air carriers, including Canadian charter air taxi operators as defined in...

Directions for combustion engine aerosol measurement in the 21st century.

PubMed

Maricq, M Matti; Maldonado, Hector

2010-10-01

The Coordinating Research Council convened two Real-Time PM Measurement Workshops in December 2008 and March 2009 to take an intensive look at the current status and future directions of combustion aerosol measurement. The purpose was to examine the implications of parallel rapid developments over the past decade in ambient aerosol science, engine aftertreatment technology, and aerosol measurement methodology, which provide benefits and challenges to the stakeholders in air quality management. The workshops were organized into sessions targeting key issues in ambient and source combustion particulate matter (PM). These include (1) metrics to characterize and quantify PM, (2) the need to reconcile ambient and source measurements, (3) the role of atmospheric transformations on modeling emissions and exposures, (4) the impact of sampling conditions on PM measurement, and (5) the potential benefits of novel PM instrumentation. This paper distills the material presented by subject experts and the insights derived from the in-depth discussions that formed the core of each session. The paper's objectives are to identify areas of consensus that allow wider practical application of the past decade's advances in combustion aerosol measurement to improve emissions and air quality modeling, develop emissions reduction strategies, and to recommend directions for progress on issues in which uncertainties remain.

Fogwater Chemistry and Air Quality in the Texas-Louisiana Gulf Coast Corridor

NASA Astrophysics Data System (ADS)

Kommalapati, R. R.; Raja, S.; Ravikrishna, R.; Murugesan, K.; Collett, J. L.; Valsaraj, K.

2007-05-01

The presence of fog water in polluted atmosphere can influence atmospheric chemistry and air quality. The study of interactions between fog water and atmospheric gases and aerosols are very important in understanding the atmospheric fate of the pollutants. In this Study several air samples and fogwater samples were collected in the heavily industrialized area of Gulf Coast corridor( Houston, TX and Baton Rouge, LA). A total of 32 fogwater samples were collected, comprising of nine fog events in Baton Rouge (Nov 2004 to Feb 2005) and two fog events in Houston (Feb, 2006), during the fog sampling campaigns. These samples were analyzed for pH, total and dissolved carbon, major inorganic ions, organic acids, and aromatics, aldehydes, VOCs, and linear alkanes organic compounds. Fogwater samples collected in Houston show clear influence of marine and anthropogenic environment, while Baton Rouge samples reveal a relatively less polluted environment. Also, a time series observation of air samples indicated that fog event at the monitoring site impacted the air concentrations of the pollutants. This is attributed to presence of surface active organic matter in fog water.

Water- and air-quality and surficial bed-sediment monitoring of the Sweetwater Reservoir watershed, San Diego County, California, 2003-09

USGS Publications Warehouse

Mendez, Gregory O.; Majewski, Michael S.; Foreman, William T.; Morita, Andrew Y.

2015-01-01

Sampling results show concentrations of the gasoline oxygenate methyl tert-butyl ether in water and air samples declined after it was phased out by the State of California in January 2004. The largest concentrations of gasoline hydrocarbons benzene and toluene in water were detected at or near the surface of the SWR. Isophorone and phenol were the two most frequently detected BNA compounds in water. Diuron, prometon, and simazine were the most frequently detected pesticide compounds in water. Concentrations of benzene and toluene in air samples were highest during the cooler months and had a consistent seasonal pattern over time. Ten PAH compounds were detected frequently in air samples. Twelve pesticide compounds were also detected in air samples. Surficial bed-sediment samples were analyzed for 53 PAHs; 22 of the compounds had one or more detections. Surficial bed-sediment samples were analyzed for 22 organic compounds; only 6 compounds had one or more detections. Surficial bed-sediment samples were analyzed for 37 metals.

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.

Determination of sub-part-per-million levels of formaldehyde in air using active or passive sampling on 2,4-dinitrophenylhydrazine-coated glass fiber filters and high-performance liquid chromatography

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

Levin, J.O.; Andersson, K.; Lindahl, R.

1985-05-01

Formaldehyde is sampled from air with the use of a standard miniature glass fiber filter impregnated with 2,4-dinitrophenylhydrazine and phosphoric acid. The formaldehyde hydrazone is desorbed from the filter with acetonitrile and determined by high-performance liquid chromatography using UV detection at 365 nm. Recovery of gas-phase-generated formaldehyde as hydrazone from a 13-mm impregnated filter is 80-100% in the range 0.3-30 ..mu..g of formaldehyde. This corresponds to 0.1-10 mg/m/sup 3/ in a 3-L air sample. When the filter sampling system is used in the active mode, air can be sampled at a rate of up to 1 L/min, affording an overallmore » sensitivity of about 1 ..mu..g/m/sup 3/ based on a 60-L air sample. Results are given from measurements of formaldehyde in indoor air. The DNP-coated filters were also evaluated for passive sampling. In this case 37-mm standard glass fibers were used and the sampling rate was 55-65 mL/min in two types of dosimeters. The diffusion samplers are especially useful for personal exposure monitoring in the work environment. 24 references, 2 figures, 4 tables.« less

Laser Spectroscopy Monitoring of 13C18O16O and 12C17O16O of Atmospheric Carbon Dioxide

NASA Astrophysics Data System (ADS)

Shorter, J. H.; Nelson, D. D.; Ono, S.; McManus, J. B.; Zahniser, M. S.

2017-12-01

One of the main challenges to making accurate predictions of future changes in CO2 concentration is the capability to determine what fraction of human produced CO2 remains in the atmosphere. We present our progress in the application of Tunable Infrared Laser Direct Absorption Spectroscopy (TILDAS) to the measurement of the primary clumped (13C18O16O) as well as 17O (12C17O16O) isotopologues of atmospheric CO2, as a tracer of its sources and sinks. We expect unique isotopologue signals in CO2 from high-temperature combustion sources, plants, soils, and air-sea exchange processes. High sampling frequency (a few minutes for each sample vs. reference cycle) achieved by a TILDAS instrument is expected to enable us to document local heterogeneous sources and temporal variations. The TILDAS is equipped with a newly developed 400-meter absorption cell. We designed a dual pressure measurement technique in which the clumped isotopologue, 13C18O16O, and 13C16O16O are first measured at 30 torr cell pressure. This is followed by measurement of 12C17O16O, 12C18O16O and 12C16O16O at lower ( 5 torr) cell pressure. Isotopologue ratios are compared between reference and sample gases. Preliminary tests demonstrated a precision approaching 0.03 ‰ for the ratio 13C18O16O/13C16O16O and 0.08‰ for Δ13C18O16O value (1σ repeatability for 4 min sample vs. reference cycle). Sample size for a single analysis is approximately 100 mL of air (1.6μmol of CO2). Given the previously observed range of variations for Δ13C18O16O and Δ17O values as large as 0.6 to 0.3 ‰, respectively, TILDAS offers a novel approach for real time monitoring of atmospheric CO2 isotopologues. It was found that achieving better than 0.1‰ requires careful matching of CO2 mixing ratios between reference and sample air. A primary cause of pressure and mixing ratio dependence is inaccurate baseline fitting (analogous to abundance sensitivity or pressure baseline for IRMS). Given that mixing ratios of atmospheric CO2 can vary as much as 50% or more, a dynamic dilution scheme, where sample air is diluted by CO2 free air to match the reference mixing ratio, is being developed. An in-line calibration source of hot, equilibrated CO2 isotopologues is also being tested. We will discuss the current instrument performance, areas for improvement, and project future applications.

Primary VOC emissions from Commercial Aircraft Jet Engines

NASA Astrophysics Data System (ADS)

Kilic, Dogushan; Huang, Rujin; Slowik, Jay; Brem, Benjamin; Durdina, Lukas; Rindlisbacher, Theo; Baltensperger, Urs; Prevot, Andre

2014-05-01

Air traffic is growing continuously [1]. The increasing number of airplanes leads to an increase of aviation emissions giving rise to environmental concerns globally by high altitude emissions and, locally on air quality at the ground level [2]. The overall impact of aviation emissions on the environment is likely to increase when the growing air transportation trend [2] is considered. The Aviation Particle Regulatory Instrumentation Demonstration Experiment (APRIDE)-5 campaign took place at Zurich Airport in 2013. In this campaign, aircraft exhaust is sampled during engine acceptance tests after engine overhaul at the facilities of SR Technics. Direct sampling from the engine core is made possible due to the unique fixed installation of a retractable sampling probe and the use of a standardized sampling system designed for the new particulate matter regulation in development for aircraft engines. Many of the gas-phase aircraft emissions, e.g. CO2, NOX, CO, SO2, hydrocarbons, and volatile organic compounds (VOC) were detected by the instruments in use. This study, part of the APRIDE-5 campaign, focuses on the primary VOC emissions in order to produce emission factors of VOC species for varying engine operating conditions which are the surrogates for the flight cycles. Previously, aircraft plumes were sampled in order to quantify VOCs by a proton transfer reaction quadrupole mass spectrometer (PTR-MS) [3]. This earlier study provided a preliminary knowledge on the emission of species such as methanol, acetaldehyde, acetone, benzene and toluene by varying engine thrust levels. The new setup was (i) designed to sample from the diluted engine exhaust and the new tool and (ii) used a high resolution time of flight PTR-MS with higher accuracy for many new species, therefore providing a more detailed and accurate inventory. We will present the emission factors for species that were quantified previously, as well as for many additional VOCs detected during the campaign. References 1."Annual Review 2013", International Air Transport Association (IATA) 2014, Page 8, available on: http://www.iata.org/about/Documents/iata-annual-review-2013-en.pdf. 2."Summary for Policymakers: IPCC Special Report Aviation and the Global Atmosphere", 1999, pp. 5-10. 3."Hydrocarbon emissions from in-use commercial aircraft during airport operations", Herndon S.C., Rogers T., Dunlea E.J., Jayne J.T., Miake-Lye R., Knighton B., Environ Sci. Technol. 2006 Jul 15;40(14):4406-13.

Cyclic deformations in the Opalinus clay: a laboratory experiment

NASA Astrophysics Data System (ADS)

Huber, Emanuel; Huggenberger, Peter; Möri, Andreas; Meier, Edi

2015-04-01

The influence of tunnel climate on deformation cycles of joint openings and closings is often observed immediately after excavation. At the EZ-B niche in the Mt. Terri rock laboratory (Switzerland), a cyclic deformation of the shaly Opalinus clay has been monitored for several years. The deformation cycles of the joints parallel to the clay bedding planes correlate with seasonal variations in relative humidity of the air in the niche. In winter, when the relative humidity is the lowest (down to 65%), the joints open as the clay volume decreases, whereas they tend to close in the summer when the relative humidity reaches up to 100%. Furthermore, in situ measurements have shown the trend of an increasingly smaller aperture of joints with time. A laboratory experiment was carried out to reproduce the observed cyclic deformation in a climate chamber using a core sample of Opalinus clay. The main goal of the experiment was to investigate the influence of the relative humidity on the deformation of the Opalinus clay while excluding the in situ effects (e.g. confining stress). The core sample of Opalinus clay was put into a closed ended PVC tube and the space between the sample and the tube was filled with resin. Then, the sample (size: 28 cm × 14 cm × 6.5 cm) was cut in half lengthways and the open end was cut, so that the half-core sample could move in one direction. The mounted sample was exposed to wetting and drying cycles in a climate chamber. Air temperature, air humidity and sample weight were continuously recorded. Photographs taken at regular time intervals by a webcam allowed the formation/deformation of cracks on the surface of the sample to be monitored. A crackmeter consisting of a double-plate capacitor attached to the core sample was developed to measure the dynamics of the crack opening and closing. Preliminary results show that: - Deformation movements during different climate cycles can be visualized with the webcam - The crackmeter signal gives a relatively precise response for relative humidity below 80% - The sample weight variations are clearly related to the climatic conditions (temperature and relative humidity) and associated with deformation of the sample (widening and narrowing of the cracks) - The control of the relative humidity in the climate chamber turned out to be difficult in a laboratory without climate conditioning, especially during summer time

Day and night profiles of tropospheric nitrous oxide

NASA Technical Reports Server (NTRS)

Cofer, Wesley R., III; Connors, Vickie S.; Levine, Joel S.; Edahl, Robert A., Jr.

1986-01-01

Daytime and nighttime vertical profiles of the tropospheric trace gas N2O were determined from grab sample collections off the Atlantic and Gulf coasts of Florida. The grab samples were collected during the week of October 7-13, 1984, from a Lear jet during descent spirals over an altitude range of 12.5-0.3 km in approximately 1.2-km intervals. During this period there were two distinct airflow regimes sampled: (1) the surface boundary layer (less than 2 km), in which the wind direction was typically easterly; and (2) the regime above the boundary layer, which was predominantly characterized by westerly flow. N2O mixing ratios, normalized to dry air, were determined from 148 daytime and nighttime samplings. N2O was found to be uniformly mixed at all altitudes at 301.9 + or - 2.4 parts per billion by volume.

Selected papers in the hydrologic sciences 1984; July 1984

USGS Publications Warehouse

Meyer, Eric L.

1984-01-01

The rapid, accurate measurement of the oxygen content of soil gas in the unsaturated zone or dissolved oxygen in soil water in the saturated zone can be useful in wetland vegetation studies. A method has been devised and tested in the Great Dismal Swamp, a wetland with fine silt-clay and organic soils, that appears to provide good results. A 60-milliliter sample of soil gas or water is withdrawn from permanently installed chambers at various depths in the soil profile. The oxygen concentration of air samples is measured with a specially constructed analyzer cell fitted to the polarographic oxygen electrode of a portable oxygen meter. The dissolved oxygen concentration of water samples is measured directly with the oxygen electrode while stirring the sample in a 32-milliliter glass bottle with a portable magnetic stirrer. Field tests with duplicate chamber installations showed that consistent results are obtained for soil gas and water.

Recommended operating procedure No. 51: Glass source assessment sampling system (glass SASS). Final report, Jul 90-Jan 91

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

Grote, R.A.

1991-05-01

The report is a recommended operating procedure (ROP), prepared for use in research activities conducted by EPA's Air and Energy Engineering Research Laboratory (AEERL). The method described is applicable to the stack sampling of flue gas from a rotary kiln and to associated equipment of AEERL's Combustion Research Branch. It has been the standard method of sampling kiln flue gas due to the transient nature of the puff development and its capability to sample the maximum volume over the shortest time period. ROPs describe non-routine or experimental research operations where some judgment in application may be warranted. ROPs may notmore » be applicable to activities conducted by other research groups, and should not be used in place of standard operating procedures. Use of ROPs must be accompanied by an understanding of the purpose and scope. Questions should be directed to the author.« less

Fast determination of 3-ethenylpyridine as a marker of environmental tobacco smoke at trace level using direct atmospheric pressure chemical ionization tandem mass spectrometry

NASA Astrophysics Data System (ADS)

Jiang, Cheng-Yong; Sun, Shi-Hao; Zhang, Qi-Dong; Liu, Jun-Hui; Zhang, Jian-Xun; Zong, Yong-Li; Xie, Jian-Ping

2013-03-01

A method with atmospheric pressure chemical ionization tandem mass spectrometry (APCI-MS/MS) was developed and applied to direct analysis of Environmental Tobacco Smoke (ETS), using 3-ethenylpyridine (3-EP) as a vapour-phase marker. In this study, the ion source of APCI-MS/MS was modified and direct analysis of gas sample was achieved by the modified instrument. ETS samples were directly introduced, via an atmospheric pressure inlet, into the APCI source. Ionization was carried out in positive-ion APCI mode and 3-EP was identified by both full scan mode and daughter scan mode. Quantification of 3-EP was performed by multiple reaction monitoring (MRM) mode. The calibration curve was obtained in the range of 1-250 ng L-1 with a satisfactory regression coefficient of 0.999. The limit of detection (LOD) and the limit of quantification (LOQ) were 0.5 ng L-1 and 1.6 ng L-1, respectively. The precision of the method, calculated as relative standard deviation (RSD), was characterized by repeatability (RSD 3.92%) and reproducibility (RSD 4.81%), respectively. In real-world ETS samples analysis, compared with the conventional GC-MS method, the direct APCI-MS/MS has shown better reliability and practicability in the determination of 3-EP at trace level. The developed method is simple, fast, sensitive and repeatable; furthermore, it could provide an alternative way for the determination of other volatile pollutants in ambient air at low levels.

FRC Compression Heating Experiment (FRCHX) at AFRL

DTIC Science & Technology

2007-06-01

Air Force Research Laboratory ( AFRL ) and Los Alamos National Laboratory (LANL) have been... Air Force Research Laboratory , Directed Energy Directorate, 3550 Aberdeen Avenue SE Kirtland AFB, NM 87117-5776 USA 8. PERFORMING ORGANIZATION REPORT...Matt Domonkos, Don Gale, Bernard Martinez, Jerry Parker, Dale Ralph, Ed Ruden, and Wayne Sommars Air Force Research Laboratory , Directed

76 FR 23876 - Clarifications to Indian Tribes' Clean Air Act Regulatory Requirements; Direct Final Amendments

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-29

... Clarifications to Indian Tribes' Clean Air Act Regulatory Requirements; Direct Final Amendments AGENCY... to amend certain Clean Air Act regulations pertaining to Indian tribes. This action changes the title... Subpart L, which includes provisions specific to implementation plans for tribes located in EPA Region IX...

Air pollution and climate response to aerosol direct radiative effects: A modeling study of decadal trends across the northern hemisphere

EPA Science Inventory

Decadal hemispheric Weather Research and Forecast-Community Multiscale Air Quality simulations from 1990 to 2010 were conducted to examine the meteorology and air quality responses to the aerosol direct radiative effects. The model's performance for the simulation of hourly surfa...

14 CFR 119.21 - Commercial operators engaged in intrastate common carriage and direct air carriers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Commercial operators engaged in intrastate common carriage and direct air carriers. 119.21 Section 119.21 Aeronautics and Space FEDERAL AVIATION...: CERTIFICATION AND OPERATIONS CERTIFICATION: AIR CARRIERS AND COMMERCIAL OPERATORS Applicability of Operating...

14 CFR 119.21 - Commercial operators engaged in intrastate common carriage and direct air carriers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Commercial operators engaged in intrastate common carriage and direct air carriers. 119.21 Section 119.21 Aeronautics and Space FEDERAL AVIATION...: CERTIFICATION AND OPERATIONS CERTIFICATION: AIR CARRIERS AND COMMERCIAL OPERATORS Applicability of Operating...

14 CFR 119.21 - Commercial operators engaged in intrastate common carriage and direct air carriers.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Commercial operators engaged in intrastate common carriage and direct air carriers. 119.21 Section 119.21 Aeronautics and Space FEDERAL AVIATION...: CERTIFICATION AND OPERATIONS CERTIFICATION: AIR CARRIERS AND COMMERCIAL OPERATORS Applicability of Operating...

14 CFR 119.21 - Commercial operators engaged in intrastate common carriage and direct air carriers.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Commercial operators engaged in intrastate common carriage and direct air carriers. 119.21 Section 119.21 Aeronautics and Space FEDERAL AVIATION...: CERTIFICATION AND OPERATIONS CERTIFICATION: AIR CARRIERS AND COMMERCIAL OPERATORS Applicability of Operating...

14 CFR 119.21 - Commercial operators engaged in intrastate common carriage and direct air carriers.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Commercial operators engaged in intrastate common carriage and direct air carriers. 119.21 Section 119.21 Aeronautics and Space FEDERAL AVIATION...: CERTIFICATION AND OPERATIONS CERTIFICATION: AIR CARRIERS AND COMMERCIAL OPERATORS Applicability of Operating...