Science.gov

Sample records for airborne molecular contamination

  1. Airborne molecular contamination: quality criterion for laser and optical components

    NASA Astrophysics Data System (ADS)

    Otto, Michael

    2015-02-01

    Airborne molecular contaminations (AMCs) have been recognized as a major problem in semiconductor fabrication. Enormous technical and financial efforts are made to remove or at least reduce these contaminations in production environments to increase yield and process stability. It can be shown that AMCs from various sources in laser devices have a negative impact on quality and lifetime of lasers and optical systems. Outgassing of organic compounds, especially condensable compounds were identified as the main source for deterioration of optics. These compounds can lead to hazing on surfaces of optics, degradation of coating, reducing the signal transmission or the laser signal itself and can enhance the probability of laser failure and damage. Sources of organic outgassing can be molding materials, resins, seals, circuit boards, cable insulation, coatings, paints and others. Critical compounds are siloxanes, aromatic amines and high boiling aromatic hydrocarbons like phthalates which are used as softeners in plastic materials. Nowadays all sensitive assembly steps are performed in controlled cleanroom environments to reduce risks of contamination. We will demonstrate a high efficient air filter concept to remove AMCs for production environments with special AMC filters and methods for the qualification and monitoring of these environments. Additionally, we show modern techniques and examples for the pre-qualification of materials. For assembled components, we provide sampling concepts for a routine measurement for process, component and product qualification. A careful selection of previously tested and certified materials and components is essential to guarantee the quality of lasers and optical devices.

  2. Low pressure drop filtration of airborne molecular organic contaminants using open-channel networks

    NASA Astrophysics Data System (ADS)

    Dallas, Andrew J.; Joriman, Jon; Ding, Lefei; Weineck, Gerald; Seguin, Kevin

    2007-03-01

    Airborne molecular contamination (AMC) continues to play a very decisive role in the performance of many microelectronic devices and manufacturing processes. Besides airborne acids and bases, airborne organic contaminants such as 1-methyl-2-pyrrolidinone (NMP), hexamethyldisiloxane (HMDSO), trimethylsilanol (TMS), perfluoroalkylamines and condensables are of primary concern in these applications. Currently, the state of the filtration industry is such that optimum filter life and removal efficiency for organics is offered by granular carbon filter beds. However, the attributes that make packed beds of activated carbon extremely efficient also impart issues related to elevated filter weight and pressure drop. Most of the lower pressure drop AMC filters currently offered are quite expensive and are simply pleated combinations of various adsorptive and reactive media. On the other hand, low pressure drop filters, such as those designed as open-channel networks (OCN's), offer good filter life and removal efficiency with the additional benefits of significant reductions in overall filter weight and pressure drop. Equally important for many applications, the OCN filters can reconstruct the airflow so as to enhance the operation of a tool or process. For tool mount assemblies and fan filter units (FFUs) this can result in reduced fan and blower speeds, which subsequently can provide reduced vibration and energy costs. Additionally, these low pressure drop designs can provide a cost effective way of effectively removing AMC in full fab (or HVAC) filtration applications without significantly affecting air-handling requirements. Herein, we will present a new generation of low pressure drop OCN filters designed for the removal of airborne organics in a wide range of applications.

  3. Low pressure drop airborne molecular contaminant filtration using open-channel networks

    NASA Astrophysics Data System (ADS)

    Dallas, Andrew J.; Ding, Lefei; Joriman, Jon; Zastera, Dustin; Seguin, Kevin; Empson, James

    2006-03-01

    Airborne molecular contamination (AMC) continues to play a very decisive role in the performance of many microelectronic devices and manufacturing processes. Currently, the state of the filtration industry is such that optimum filter life and removal efficiency for AMC is offered by granular filter beds. However, the attributes that make packed beds of adsorbents extremely efficient also impart issues related to elevated filter weight and pressure drop. Most of the low pressure drop AMC filters currently offered tend to be quiet costly and contaminant nonspecific. Many of these low pressure drop filters are simply pleated combinations of various adsorptive and reactive media. On the other hand, low pressure drop filters, such as those designed as open-channel networks (OCNs), can still offer good filter life and removal efficiency, with the additional benefits of significant reductions in overall filter weight and pressure drop. Equally important for many applications, the OCN filters can reconstruct the airflow so as to enhance the operation of a tool or process. For tool mount assemblies and full fan unit filters this can result in reduced fan and blower speeds, which subsequently can provide reduced vibration and energy costs. Additionally, these low pressure drop designs can provide a cost effective way of effectively removing AMC in full fab (or HVAC) filtration applications without significantly affecting air-handling requirements. Herein, we will present a new generation of low pressure drop OCN filters designed for AMC removal in a wide range of applications.

  4. Soft X-ray-assisted detection method for airborne molecular contaminations (AMCs)

    NASA Astrophysics Data System (ADS)

    Kim, Changhyuk; Zuo, Zhili; Finger, Hartmut; Haep, Stefan; Asbach, Christof; Fissan, Heinz; Pui, David Y. H.

    2015-03-01

    Airborne molecular contaminations (AMCs) represent a wide range of gaseous contaminants in cleanrooms. Due to the unintentional nanoparticle or haze formation as well as doping caused by AMCs, improved monitoring and controlling methods for AMCs are urgent in the semiconductor industry. However, measuring ultra-low concentrations of AMCs in cleanrooms is difficult, especially, behind a gas filter. In this study, a novel detection method for AMCs, which is on-line, economical, and applicable for diverse AMCs, was developed by employing gas-to-particle conversion with soft X-ray, and then measuring the generated nanoparticles. Feasibility study of this method was conducted through the evaluations of granular-activated carbons (GACs), which are widely used AMC filter media. Sulfur dioxide (SO2) was used as an AMC for the feasibility study. Using this method, the ultra-low concentrations of SO2 behind GACs were determined in terms of concentrations of generated sulfuric acid (H2SO4) nanoparticles. By calculating SO2 concentrations from the nanoparticle concentrations using empirical correlation equations between them, remarkable sensitivity of this method to SO2 was shown, down to parts-per-trillions, which are too low to detect using commercial gas sensors. Also, the calculated SO2 concentrations showed good agreement with those measured simultaneously by a commercial SO2 monitor at parts-per-billions.

  5. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT RESEARCH PLAN

    EPA Science Inventory

    The goal of the Western Airborne Contaminants Assessment Project (WACAP) is to assess the deposition of airborne contaminants in Western National Parks, providing regional and local information on exposure, accumulation, impacts, and probable sources. This project is being desig...

  6. Monitoring airborne molecular contamination: a quantitative and qualitative comparison of real-time and grab-sampling techniques

    NASA Astrophysics Data System (ADS)

    Shupp, Aaron M.; Rodier, Dan; Rowley, Steven

    2007-03-01

    Monitoring and controlling Airborne Molecular Contamination (AMC) has become essential in deep ultraviolet (DUV) photolithography for both optimizing yields and protecting tool optics. A variety of technologies have been employed for both real-time and grab-sample monitoring. Real-time monitoring has the advantage of quickly identifying "spikes" and upset conditions, while 2 - 24 hour plus grab sampling allows for extremely low detection limits by concentrating the mass of the target contaminant over a period of time. Employing a combination of both monitoring techniques affords the highest degree of control, lowest detection limits, and the most detailed data possible in terms of speciation. As happens with many technologies, there can be concern regarding the accuracy and agreement between real-time and grab-sample methods. This study utilizes side by side comparisons of two different real-time monitors operating in parallel with both liquid impingers and dry sorbent tubes to measure NIST traceable gas standards as well as real world samples. By measuring in parallel, a truly valid comparison is made between methods while verifying the results against a certified standard. The final outcome for this investigation is that a dry sorbent tube grab-sample technique produced results that agreed in terms of accuracy with NIST traceable standards as well as the two real-time techniques Ion Mobility Spectrometry (IMS) and Pulsed Fluorescence Detection (PFD) while a traditional liquid impinger technique showed discrepancies.

  7. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

    A method of estimation of inhalation exposure to airborne soil contaminants is presented. this method is derived from studies of airborne soil particles with radioactive tags. The concentration of contaminants in air (g/m{sup 3}) can be derived from the product of M, the suspended respirable dust mass concentration (g/m{sup 3}), S, the concentration of contaminant in the soil (g/g), and E{sub f}, an enhancement factor. Typical measurement methods and values of M, and E{sub f} are given along with highlights of experiences with this method.

  8. Monitoring airborne alpha-emitter contamination

    SciTech Connect

    Kerr, P.L.; Koster, J.E.; Conaway, J.G.; Bounds, J.A.; Whitley, C.W.; Steadman, P.A.

    1998-02-01

    Facilities that may produce airborne alpha emitter contamination require a continuous air monitoring (CAM) system. However, these traditional CAMs have difficulty in environments with large quantities of non-radioactive particulates such as dust and salt. Los Alamos has developed an airborne plutonium sensor (APS) for the REBOUND experiment at the Nevada Test Site which detects alpha contamination directly in the air, and so is less vulnerable to the problems associated with counting activity on a filter. In addition, radon compensation is built into the detector by the use of two measurement chambers.

  9. Spacecraft Maximum Allowable Concentrations for Airborne Contaminants

    NASA Technical Reports Server (NTRS)

    James, John T.

    2008-01-01

    The enclosed table lists official spacecraft maximum allowable concentrations (SMACs), which are guideline values set by the NASA/JSC Toxicology Group in cooperation with the National Research Council Committee on Toxicology (NRCCOT). These values should not be used for situations other than human space flight without careful consideration of the criteria used to set each value. The SMACs take into account a number of unique factors such as the effect of space-flight stress on human physiology, the uniform good health of the astronauts, and the absence of pregnant or very young individuals. Documentation of the values is given in a 5 volume series of books entitled "Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants" published by the National Academy Press, Washington, D.C. These books can be viewed electronically at http://books.nap.edu/openbook.php?record_id=9786&page=3. Short-term (1 and 24 hour) SMACs are set to manage accidental releases aboard a spacecraft and permit risk of minor, reversible effects such as mild mucosal irritation. In contrast, the long-term SMACs are set to fully protect healthy crewmembers from adverse effects resulting from continuous exposure to specific air pollutants for up to 1000 days. Crewmembers with allergies or unusual sensitivity to trace pollutants may not be afforded complete protection, even when long-term SMACs are not exceeded. Crewmember exposures involve a mixture of contaminants, each at a specific concentration (C(sub n)). These contaminants could interact to elicit symptoms of toxicity even though individual contaminants do not exceed their respective SMACs. The air quality is considered acceptable when the toxicity index (T(sub grp)) for each toxicological group of compounds is less than 1, where T(sub grp), is calculated as follows: T(sub grp) = C(sub 1)/SMAC(sub 1) + C(sub 2/SMAC(sub 2) + ...+C(sub n)/SMAC(sub n).

  10. The Western Airborne Contaminant Assessment Project (WACAP): An interdisciplinary evaluation of the impacts of airborne contaminants in Western U.S. National Parks

    EPA Science Inventory

    The Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 by the National Park Service to determine if airborne contaminants were having an impact on remote western ecosystems. Multiple sample media (snow, water, sediment, fish and terrestrial vegetation...

  11. Airborne soil particulates as vehicles for Salmonella contamination of tomatoes.

    PubMed

    Kumar, Govindaraj Dev; Williams, Robert C; Al Qublan, Hamzeh M; Sriranganathan, Nammalwar; Boyer, Renee R; Eifert, Joseph D

    2017-02-21

    The presence of dust is ubiquitous in the produce growing environment and its deposition on edible crops could occur. The potential of wind-distributed soil particulate to serve as a vehicle for S. Newport transfer to tomato blossoms and consequently, to fruits, was explored. Blossoms were challenged with previously autoclaved soil containing S. Newport (9.39log CFU/g) by brushing and airborne transfer. One hundred percent of blossoms brushed with S. Newport-contaminated soil tested positive for presence of the pathogen one week after contact (P<0.0001). Compressed air was used to simulate wind currents and direct soil particulates towards blossoms. Airborne soil particulates resulted in contamination of 29% of the blossoms with S. Newport one week after contact. Biophotonic imaging of blossoms post-contact with bioluminescent S. Newport-contaminated airborne soil particulates revealed transfer of the pathogen on petal, stamen and pedicel structures. Both fruits and calyxes that developed from blossoms contaminated with airborne soil particulates were positive for presence of S. Newport in both fruit (66.6%) and calyx (77.7%). Presence of S. Newport in surface-sterilized fruit and calyx tissue tested indicated internalization of the pathogen. These results show that airborne soil particulates could serve as a vehicle for Salmonella. Hence, Salmonella contaminated dust and soil particulate dispersion could contribute to pathogen contamination of fruit, indicating an omnipresent yet relatively unexplored contamination route.

  12. Airborne trace organic contaminant removal using thermally regenerable multi-media layered sorbents

    NASA Technical Reports Server (NTRS)

    Atwater, James E.; Holtsnider, John T.

    1991-01-01

    A cyclic two-step process is described which forms the basis for a simple and highly efficient air purification technology. Low molecular weight organic vapors are removed from contaminated airstreams by passage through an optimized sequence of sorbent media layers. The contaminant loaded sorbents are subsequently regenerated by thermal desorption into a low volume inert gas environment. A mixture of airborne organic contaminants consisting of acetone, 2-butanone, ethyl acetate, Freon-113 and methyl chloroform has been quantitatively removed from breathing quality air using this technique. The airborne concentrations of all contaminants have been reduced from initial Spacecraft Maximum Allowable Concentration (SMAC) levels to below the analytical limits of detection. No change in sorption efficiency was observed through multiple cycles of contaminant loading and sorbent regeneration via thermal desorption.

  13. AIRBORNE CONTAMINANTS IN WESTERN NORTH AMERICAN NATIONAL PARKS--WHAT WE KNOW AND WANT TO LEARN

    EPA Science Inventory

    The National Park Service initiated the Western Airborne Contaminants Assessment Project (WACAP) in 2002 to determine if airborne contaminants from regional or distant sources have an impact on remote (typically high elevation) western ecosystems, including Alaska. Eight Nationa...

  14. ARE AIRBORNE CONTAMINANTS A RISK FACTOR TO AQUATIC ECOSYSTEMS IN REMOTE WESTERN NATIONAL PARKS (USA)

    EPA Science Inventory

    The Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 by the National Park Service to determine if airborne contaminants were having an impact on remote western ecosystems. Multiple sample media (snow, water, sediment, fish and terrestrial vegetation...

  15. WHICH AIRBORNE CONTAMINANTS POSE THE GREATEST RISK TO WESTERN NATIONAL PARKS (USA)?

    EPA Science Inventory

    The Western Airborne Contaminants Assessment Project (WACAP) was initiated in 2002 by the National Park Service to determine if airborne contaminants where having an impact on remote western ecosystems. Multiple sample media (snow, water, sediment, fish and terrestrial vegetatio...

  16. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Air Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... Workroom Air Adopted by ACGIH for 1973,” pages 1 through 54, which are hereby incorporated by reference...

  17. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Air Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... Workroom Air Adopted by ACGIH for 1973,” pages 1 through 54, which are hereby incorporated by reference...

  18. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Air Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... Workroom Air Adopted by ACGIH for 1973,” pages 1 through 54, which are hereby incorporated by reference...

  19. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Air Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... Workroom Air Adopted by ACGIH for 1973,” pages 1 through 54, which are hereby incorporated by reference...

  20. 30 CFR 56.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... AND NONMETAL MINE SAFETY AND HEALTH SAFETY AND HEALTH STANDARDS-SURFACE METAL AND NONMETAL MINES Air Quality and Physical Agents Air Quality § 56.5001 Exposure limits for airborne contaminants. Except as... Workroom Air Adopted by ACGIH for 1973,” pages 1 through 54, which are hereby incorporated by reference...

  1. 30 CFR 56.5005 - Control of exposure to airborne contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Control of exposure to airborne contaminants... Air Quality and Physical Agents Air Quality § 56.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful airborne contaminants shall be, insofar as feasible, by...

  2. Airborne myxomycete spores: detection using molecular techniques

    NASA Astrophysics Data System (ADS)

    Kamono, Akiko; Kojima, Hisaya; Matsumoto, Jun; Kawamura, Kimitaka; Fukui, Manabu

    2009-01-01

    Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.

  3. Comprehensive analysis of airborne contaminants from recent Spacelab missions

    NASA Technical Reports Server (NTRS)

    Matney, M. L.; Boyd, J. F.; Covington, P. A.; Leano, H. J.; Pierson, D. L.; Limero, T. F.; James, J. T.

    1993-01-01

    The Shuttle experiences unique air contamination problems because of microgravity and the closed environment. Contaminant build-up in the closed atmosphere and the lack of a gravitational settling mechanism have produced some concern in previous missions about the amount of solid and volatile airborne contaminants in the Orbiter and Spacelab. Degradation of air quality in the Orbiter/Spacelab environment, through processes such as chemical contamination, high solid-particulate levels, and high microbial levels, may affect crew performance and health. A comprehensive assessment of the Shuttle air quality was undertaken during STS-40 and STS-42 missions, in which a variety of air sampling and monitoring techniques were employed to determine the contaminant load by characterizing and quantitating airborne contaminants. Data were collected on the airborne concentrations of volatile organic compounds, microorganisms, and particulate matter collected on Orbiter/Spacelab air filters. The results showed that STS-40/42 Orbiter/Spacelab air was toxicologically safe to breathe, except during STS-40 when the Orbiter Refrigerator/Freezer unit was releasing noxious gases in the middeck. On STS-40, the levels of airborne bacteria appeared to increase as the mission progressed; however, this trend was not observed for the STS-42 mission. Particulate matter in the Orbiter/Spacelab air filters was chemically analyzed in order to determine the source of particles. Only small amounts of rat hair and food bar (STS-40) and traces of soiless medium (STS-42) were detected in the Spacelab air filters, indicating that containment for Spacelab experiments was effective.

  4. Airborne trace contaminants of possible interest in CELSS

    NASA Technical Reports Server (NTRS)

    Garavelli, J. S.

    1986-01-01

    One design goal of Closed Ecological Life Support Systems (CELSS) for long duration space missions is to maintain an atmosphere which is healthy for all the desirable biological species and not deleterious to any of the mechanical components in that atmosphere. CELESS design must take into account the interactions of at least six major components; (1) humans and animals, (2) higher plants, (3) microalgae, (4) bacteria and fungi, (5) the waste processing system, and (6) other mechanical systems. Each of these major components can be both a source and a target of airborne trace contaminants in a CELSS. A range of possible airborne trace contaminants is discussed within a chemical classification scheme. These contaminants are analyzed with respect to their probable sources among the six major components and their potential effects on those components. Data on airborne chemical contaminants detected in shuttle missions is presented along with this analysis. The observed concentrations of several classes of compounds, including hydrocarbons, halocarbons, halosilanes, amines and nitrogen oxides, are considered with respect to the problems which they present to CELSS.

  5. Assessment of indoor airborne contamination in a wastewater treatment plant.

    PubMed

    Teixeira, Juliana V; Miranda, Sandra; Monteiro, Ricardo A R; Lopes, Filipe V S; Madureira, Joana; Silva, Gabriela V; Pestana, Nazaré; Pinto, Eugénia; Vilar, Vítor J P; Boaventura, Rui A R

    2013-01-01

    The main objective of this work was to quantify and characterize the major indoor air contaminants present in different stages of a municipal WWTP, including microorganisms (bacteria and fungi), carbon dioxide, carbon monoxide, hydrogen sulfide ammonia, formaldehyde, and volatile organic compounds (VOCs). In general, the total bacteria concentration was found to vary from 60 to >52,560 colony-forming units (CFU)/m(3), and the total fungi concentration ranged from 369 to 14,068 CFU/m(3). Generally, Gram-positive bacteria were observed in higher number than Gram-negative bacteria. CO(2) concentration ranged from 251 to 9,710 ppm, and CO concentration was either not detected or presented a level of 1 ppm. H(2)S concentration ranged from 0.1 to 6.0 ppm. NH(3) concentration was <2 ppm in most samples. Formaldehyde was <0.01 ppm at all sampling sites. The total VOC concentration ranged from 36 to 1,724 μg/m(3). Among the VOCs, toluene presented the highest concentration. Results point to indoor/outdoor ratios higher than one. In general, the highest levels of airborne contaminants were detected at the primary treatment (SEDIPAC 3D), secondary sedimentation, and sludge dehydration. At most sampling sites, the concentrations of airborne contaminants were below the occupational exposure limits (OELs) for all the campaigns. However, a few contaminants were above OELs in some sampling sites.

  6. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants. Volume 2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Aeronautics and Space Administration (NASA) is aware of the potential toxicological hazards to humans that might be associated with prolonged spacecraft missions. Despite major engineering advances in controlling the atmosphere within spacecraft, some contamination of the air appears inevitable. NASA has measured numerous airborne contaminants during space missions. As the missions increase in duration and complexity, ensuring the health and well-being of astronauts traveling and working in this unique environment becomes increasingly difficult. As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMACs) for contaminants, and to review SMACs for various space-craft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to NASA's request, the NRC organized the Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants within the Committee On Toxicology (COT). In the first phase of its work, the subcommittee developed the criteria and methods for preparing SMACs for spacecraft contaminants. The subcommittee's report, entitled Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants, was published in 1992. The executive summary of that report is reprinted as Appendix A of this volume. In the second phase of the study, the Subcommittee on Spacecraft Maximum Allowable Concentrations reviewed reports prepared by NASA scientists and contractors recommending SMACs for approximately 35 spacecraft contaminants. The subcommittee sought to determine whether the SMAC reports were consistent with the 1992 guidelines. Appendix B of this volume contains the SMAC reports for 12 chemical contaminants that have been reviewed for

  7. Airborne Contaminants in the TE Lab: How to Reduce Your Exposure.

    ERIC Educational Resources Information Center

    Zeimet, Denis E.; Merrell, Wayne L.

    1995-01-01

    Details the dangers from airborne contaminants in technology education laboratories and ways to protect students from them, including ventilation, acceptable limits, and guidelines for using respirators. (SK)

  8. Molecular contamination modeling with CTSP

    NASA Astrophysics Data System (ADS)

    Brieda, Lubos

    2016-11-01

    Spacecraft instruments and thermal control surfaces are generally highly sensitive to molecular and particulate contamination. Despite best efforts taken during assembly, integration, and test, it is impossible to completely eliminate all sources of contaminants. Contamination transport analysis then becomes of critical importance. It can be used to predict the end of life accumulation on critical surfaces from prescribed source rates. Conversely, given allowable deposition levels, contamination modeling can be used to determine the cleanliness requirements to be met prior to launch. This paper describes a recently developed code for modeling contamination transport. Unlike other tools used by the community, CTSP concurrently traces many simulation particles through small time steps. This allows the code to visualize contaminant partial pressures, and to also include aerodynamic, gravitation, or electrostatic forces. The code is demonstrated by simulating an outgassing characterization test in a bell jar.

  9. 30 CFR 57.5005 - Control of exposure to airborne contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Control of exposure to airborne contaminants... Underground § 57.5005 Control of exposure to airborne contaminants. Control of employee exposure to harmful... ventilation, or by dilution with uncontaminated air. However, where accepted engineering control measures...

  10. Occupational exposure to airborne contaminants during offshore oil drilling.

    PubMed

    Kirkhus, Niels E; Thomassen, Yngvar; Ulvestad, Bente; Woldbæk, Torill; Ellingsen, Dag G

    2015-07-01

    The aim was to study exposure to airborne contaminants in oil drillers during ordinary work. Personal samples were collected among 65 drill floor workers on four stationary and six moveable rigs in the Norwegian offshore sector. Air concentrations of drilling mud were determined based on measurements of the non-volatile mud components Ca and Fe. The median air concentration of mud was 140 μg m(-3). Median air concentrations of oil mist (180 μg m(-3)), oil vapour (14 mg m(-3)) and organic carbon (46 μg m(-3)) were also measured. All contaminants were detected in all work areas (drill floor, shaker area, mud pits, pump room, other areas). The highest air concentrations were measured in the shaker area, but the differences in air concentrations between working areas were moderate. Oil mist and oil vapour concentrations were statistically higher on moveable rigs than on stationary rigs, but after adjusting for differences in mud temperature the differences between rig types were no longer of statistical significance. Statistically significant positive associations were found between mud temperature and the concentrations of oil mist (Spearman's R = 0.46) and oil vapour (0.39), and between viscosity of base oil and oil mist concentrations. Use of pressure washers was associated with higher air concentrations of mud. A series of 18 parallel stationary samples showed a high and statistically significant association between concentrations of organic carbon and oil mist (r = 0.98). This study shows that workers are exposed to airborne non-volatilized mud components. Air concentrations of volatile mud components like oil mist and oil vapour were low, but were present in all the studied working areas.

  11. Movement of airborne contaminants in a hospital isolation room

    PubMed Central

    Eames, I.; Shoaib, D.; Klettner, C. A.; Taban, V.

    2009-01-01

    We analyse the characteristics of a force-ventilated isolation room, and the contributions to transport caused by the movement of people and doors opening/closing. The spread of fine droplets and particles can be understood, to leading order, by considering the movement of passive contaminants. A scaled (1:10) model of an isolation room (with water instead of air) was used to analyse the dilution of a passive contaminant (food dye), released either instantaneously or at a constant rate. The high level of turbulence, typical of isolation rooms, ensures that the dye concentration is uniform within the model room and mixing is perfect, and the measured mean concentration can be predicted theoretically. In a second series of experiments, the exchange generated by a door opening/closing is measured for different opening angles. A dipolar vortex is generated at the tip of the door which moves into the centre of the room, with a large coherent structure moving along the wall. The exchange volume is comparable to the swept volume of the door. Larger droplets and particles do not move passively. Their movement within a turbulent flow is studied by combining a Lagrangian model of particle movement with a kinematic simulation of a pseudo turbulent flow. The results show that while the mean fall velocity of particles is largely unchanged, turbulence significantly enhances horizontal and vertical dispersion. The horizontal spread as a function of the level of turbulence and droplet properties is estimated. The conclusions from both studies are brought together and discussed in the context of the airborne spread of contaminants within a general hospital room. PMID:19815576

  12. Anthropogenic microfibres pollution in marine biota. A new and simple methodology to minimize airborne contamination.

    PubMed

    Torre, Michele; Digka, Nikoletta; Anastasopoulou, Aikaterini; Tsangaris, Catherine; Mytilineou, Chryssi

    2016-12-15

    Research studies on the effects of microlitter on marine biota have become more and more frequent the last few years. However, there is strong evidence that scientific results based on microlitter analyses can be biased by contamination from air transported fibres. This study demonstrates a low cost and easy to apply methodology to minimize the background contamination and thus to increase results validity. The contamination during the gastrointestinal content analysis of 400 fishes was tested for several sample processing steps of high risk airborne contamination (e.g. dissection, stereomicroscopic analysis, and chemical digestion treatment for microlitter extraction). It was demonstrated that, using our methodology based on hermetic enclosure devices, isolating the working areas during the various processing steps, airborne contamination reduced by 95.3%. The simplicity and low cost of this methodology provide the benefit that it could be applied not only to laboratory but also to field or on board work.

  13. [Bacterial contamination of salvaged blood in open heart surgery: is that an airborne contamination or a normal skin flora contamination?].

    PubMed

    Ishida, T; Nakano, S; Nakatani, H; Gomi, A; Sato, T; Saegusa, N; Ito, A; Okada, A; Tazawa, Y

    2001-08-01

    We investigated sources of bacterial contamination of intraoperative salvaged blood producted by autologous transfusions device (CS; CELL SAVER 5, Heamonetics Corp., Braintree, MA). Eleven patients undergone open heart surgeries including 2 emergency operations with a median sternotomy enrolled in this study. Blood samples were drawn from salvaged blood bags. Airborne contaminants (AB) were collected by a blood agar plate put besides the operation bed for 30 minutes. The median wounds samples were collected by a swab. Bacterial growth was detected in 81.8% of salvaged blood samples. Twenty-nine bacterium were isolated from CS, 72.4% of those were Staphylococci. 9.1% of sample was positive in wound swabs. Forty bacterium were isolated from plate cultures. 65% of them were Staphylococci. Staphylococcus epidermidis and coagulase negative Staphylococcus isolated both CS and AB in the 2 cases had the same identify codes, and incubated from several AB cultures. Corynebacterium sp. is also isolated from both CS and AB cultures in other 2 same cases. In 7 out of 8 cases (87.5%), from which Staphylococci isolated in CS, the Staphylococci were cultured from AB in not the same but the other cases. In conclusion, highly incidence of the identification in identical code of Staphylococci indicated that the main source of CS contamination was highly suspected to AB.

  14. WESTERN AIRBORNE CONTAMINANTS ASSESSMENT PROJECT (WACAP): ASSESSING DEPOSITION AND IMPACTS OF PERSISTENT ORGANIC POLLUTANTS AND METALS IN SEVEN NATIONAL PARKS IN THE WESTERN UNITED STATES

    EPA Science Inventory

    Airborne contaminants, especially those that biomagnify in the food chain, can pose serious health threats to wildlife and humans. Biological effects of airborne contaminants include impacts on reproductive success, growth, behavior, disease, and survival. In response to concer...

  15. Importance of airborne contamination during dressing of beef and lamb carcasses.

    PubMed

    Burfoot, Dean; Whyte, Robin; Tinker, David; Howell, Mary; Hall, Karen; Holah, John; Smith, Debra; White, Rodger; Baker, David; McIntosh, Jane

    2006-12-01

    Carcasses along slaughter lines were exposed to normal slaughterhouse air or ultraclean air provided from a unit fitted with a HEPA filter. In cattle slaughterhouses, aerobic viable counts were measured by sponging the brisket at the end of the line to determine whether the slaughterhouse air had led to contamination of the carcasses. Furthermore, a replica cattle carcass with settle plates attached was exposed to similar conditions. The greatest contamination of the plates occurred at the hide puller (P < 0.01). The use of ultraclean air reduced the deposition of organisms onto settle plates (P < 0.01). The airborne route contributed to contamination in cattle slaughterhouses, but other vectors were more important. Further study of contamination of the brisket, at the time that it was first exposed, showed that knives transfer contamination from the hide. The use of ultraclean air at this position showed that the airborne route was a contributor to contamination (P < 0.1), but it was not the greatest vector. In lamb slaughterhouses, the highest counts on settle plates were found at the fleece puller (P < 0.05). The highest counts on the lamb carcasses were found on the brisket exposed from the start of the line to just after the fleece puller (P < 0.05). There was no clear relationship between the measured counts and the concentration of organisms in the air, indicating that the airborne route in lamb slaughterhouses contributes less to carcass contamination than do the surface contacts.

  16. Forced-air warming: a source of airborne contamination in the operating room?

    PubMed

    Albrecht, Mark; Gauthier, Robert; Leaper, David

    2009-10-10

    Forced-air-warming (FAW) is an effective and widely used means for maintaining surgical normothermia, but FAW also has the potential to generate and mobilize airborne contamination in the operating room.We measured the emission of viable and non-viable forms of airborne contamination from an arbitrary selection of FAW blowers (n=25) in the operating room. A laser particle counter measured particulate concentrations of the air near the intake filter and in the distal hose airstream. Filtration efficiency was calculated as the reduction in particulate concentration in the distal hose airstream relative to that of the intake. Microbial colonization of the FAW blower's internal hose surfaces was assessed by culturing the microorganisms recovered through swabbing (n=17) and rinsing (n=9) techniques.Particle counting revealed that 24% of FAW blowers were emitting significant levels of internally generated airborne contamination in the 0.5 to 5.0 µm size range, evidenced by a steep decrease in FAW blower filtration efficiency for particles 0.5 to 5.0 µm in size. The particle size-range-specific reduction in efficiency could not be explained by the filtration properties of the intake filter. Instead, the reduction was found to be caused by size-range-specific particle generation within the FAW blowers. Microorganisms were detected on the internal air path surfaces of 94% of FAW blowers.The design of FAW blowers was found to be questionable for preventing the build-up of internal contamination and the emission of airborne contamination into the operating room. Although we did not evaluate the link between FAW and surgical site infection rates, a significant percentage of FAW blowers with positive microbial cultures were emitting internally generated airborne contamination within the size range of free floating bacteria and fungi (<4 µm) that could, conceivably, settle onto the surgical site.

  17. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... full-shift airborne concentration of 0.1 fiber per cubic centimeter of air (f/cc). (ii) Excursion limit... cubic centimeter of air (f/cc) as averaged over a sampling period of 30 minutes. (3) Measurement of... exposure exceeding the 0.1 f/cc full-shift limit or the 1 f/cc excursion limit. When PCM results indicate...

  18. Spacecraft external molecular contamination analysis

    NASA Technical Reports Server (NTRS)

    Ehlers, H. K. F.

    1990-01-01

    Control of contamination on and around spacecraft is required to avoid adverse effects on the performance of instruments and spacecraft systems. Recent work in this area is reviewed and discussed. Specific issues and limitations to be considered as part of the effort to predict contamination effects using modeling techniques are addressed. Significant results of Space Shuttle missions in the field of molecule/surface interactions as well as their implications for space station design and operation are reviewed.

  19. Assessment of SRS radiological liquid and airborne contaminants and pathways

    SciTech Connect

    Jannik, G.T.

    1997-04-01

    This report compiles and documents the radiological critical-contaminant/critical-pathway analysis performed for SRS. The analysis covers radiological releases to the atmosphere and to surface water, which are the principal media that carry contaminants off site. During routine operations at SRS, limited amounts of radionuclides are released to the environment through atmospheric and/or liquid pathways. These releases potentially result in exposure to offsite people. Though the groundwater beneath an estimated 5 to 10 percent of SRS has been contaminated by radionuclides, there is no evidence that groundwater contaminated with these constituents has migrated offsite (Arnett, 1996). Therefore, with the notable exception of radiological source terms originating from shallow surface water migration into site streams, onsite groundwater was not considered as a potential exposure pathway to offsite people.

  20. Spacecraft maximum allowable concentrations for selected airborne contaminants, volume 1

    NASA Technical Reports Server (NTRS)

    1994-01-01

    As part of its efforts to promote safe conditions aboard spacecraft, NASA requested the National Research Council (NRC) to develop guidelines for establishing spacecraft maximum allowable concentrations (SMAC's) for contaminants, and to review SMAC's for various spacecraft contaminants to determine whether NASA's recommended exposure limits are consistent with the guidelines recommended by the subcommittee. In response to NASA's request, the NRC organized the Subcommittee on Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants within the Committee on Toxicology (COT). In the first phase of its work, the subcommittee developed the criteria and methods for preparing SMAC's for spacecraft contaminants. The subcommittee's report, entitled Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants, was published in 1992. The executive summary of that report is reprinted as Appendix A of this volume. In the second phase of the study, the Subcommittee on Spacecraft Maximum Allowable Concentrations reviewed reports prepared by NASA scientists and contractors recommending SMAC's for 35 spacecraft contaminants. The subcommittee sought to determine whether the SMAC reports were consistent with the 1992 guidelines. Appendix B of this volume contains the first 11 SMAC reports that have been reviewed for their application of the guidelines developed in the first phase of this activity and approved by the subcommittee.

  1. A new technique for processing airborne gamma ray spectrometry data for mapping low level contaminations.

    PubMed

    Aage, H K; Korsbech, U; Bargholz, K; Hovgaard, J

    1999-12-01

    A new technique for processing airborne gamma ray spectrometry data has been developed. It is based on the noise adjusted singular value decomposition method introduced by Hovgaard in 1997. The new technique opens for mapping of very low contamination levels. It is tested with data from Latvia where the remaining contamination from the 1986 Chernobyl accident together with fallout from the atmospheric nuclear weapon tests includes 137Cs at levels often well below 1 kBq/m2 equivalent surface contamination. The limiting factors for obtaining reliable results are radon in the air, spectrum stability and accurate altitude measurements.

  2. Comparison of different hand-drying methods: the potential for airborne microbe dispersal and contamination.

    PubMed

    Best, E L; Redway, K

    2015-03-01

    Efficient washing and drying of hands is important in prevention of the transfer of micro-organisms. However, knowledge surrounding the potential for microbial contamination according to hand-drying methods is limited. This study assessed the potential for airborne microbe dispersal during hand drying by four methods (paper towels, roller towel, warm air and jet air dryer) using three different models. The jet air dryer dispersed liquid from users' hands further and over a greater range (up to 1.5m) than the other drying methods (up to 0.75 m), demonstrating the differing potential risks for airborne microbe dissemination, particularly if handwashing is suboptimal.

  3. Molecular contamination math model support

    NASA Technical Reports Server (NTRS)

    Wells, R.

    1983-01-01

    The operation and features of a preprocessor for the Shuttle/Payload Contamination Evaluation Program Version 2) are described. A preliminary preprocessor for SPACE 2 is developed. Further refinements and enhancements of the preprocessor to insure complete user friendly operation, are recommended.

  4. Catalytically Active Regenerative Sorbent beds (CARS) for airborne contaminants.

    PubMed

    Akse, J R; Thompson, J O

    1995-01-01

    The Pd on Al2O3 catalyst used in the projected Space Station's Trace Contaminant Control System (TCCS) catalytic oxidizer can be poisoned by volatile halogen-, sulfur-, and nitrogen-containing organic species. Catalytically Active Regenerable Sorbents (CARS) eliminate these problematic contaminants and the large carbon bed used for their elimination in a three-step process. Contaminants are conventionally adsorbed by the CARS bed. After saturation, the bed is connected to an off-line recirculation loop, filled with hydrogen, and then heated. At temperature, contaminants are hydrogenated on catalytic sites within the bed, forming simple alkanes and acid gases that are efficiently converted to innocuous salts in an in-line alkaline bed. The CARS bed is regenerated by this cycle and alkane gases are released to be safely oxidized in the catalytic oxidizer. A challenge mixture containing Freon-113, thiophene, trichloroethylene, Halon-1301, and dichloromethane at 1670, 75, 81, 68, and 83 mg/m3 was successfully treated using this technology, demonstrating the CARS feasibility.

  5. Effect of manual feeding on the level of farmer's exposure to airborne contaminants in the confinement nursery pig house.

    PubMed

    Kim, Ki-Youn; Ko, Han-Jong; Kim, Hyeon-Tae; Kim, Chi-Nyon; Kim, Yoon-Shin; Roh, Young-Man

    2008-04-01

    The objective of the study is to demonstrate an effect of manual feeding on the level of farmer's exposure to airborne contaminants in the confinement nursery pig house. The levels of all the airborne contaminants besides respirable dust, total airborne fungi and ammonia were significantly higher in the treated nursery pig house with feeding than the control nursery pig house without feeding. Although there is no significant difference in respirable dust and total airborne fungi between the treatment and the control, their concentrations in the treated nursery pig house were also higher than the control nursery pig house. The result that the level of ammonia in the treated nursery pig house is lower than the control nursery pig house would be reasoned by the mechanism of ammonia generation in the pig house and adsorption property of ammonia to dust particles. In conclusion, manual feeding by farmer increased the exposure level of airborne contaminants compared to no feeding activity.

  6. Airborne bacterial contaminations in typical Chinese wet market with live poultry trade.

    PubMed

    Gao, Xin-Lei; Shao, Ming-Fei; Luo, Yi; Dong, Yu-Fang; Ouyang, Feng; Dong, Wen-Yi; Li, Ji

    2016-12-01

    Chinese wet markets with live poultry trade have been considered as major sources of pathogen dissemination, and sites for horizontal transfer of bacterial and viral pathogens. In this study, the pathogenic bacteria and antibiotic resistant genes (ARGs) in air samples collected at a typical Chinese wet market had been analysis and quantified. Corynebacterium minutissimum and other pathogenic bacteria accounted for 0.81-8.02% of the whole microbial community in different air samples. The four ARGs quantified in this study showed a comparable relative concentration (copies/ng_DNA) with municipal wastewater. Poultry manures were demonstrated to be important microbial contamination source in wet market, which was supported by both microbial composition based source tracking and the quantification of airborne microbial density. A series of Firmicutes and Bacteroidetes indicators of poultry area contamination were successfully screened, which will be useful for the more convenient monitoring of airborne poultry area contamination. Our results indicate bioaerosols acted as important route for the transmissions of pathogens and ARGs. Continued surveillance of airborne microbial contamination is required in poultry trade wet market.

  7. Radiation dose implications of airborne contaminant deposition to humans.

    PubMed

    Andersson, K G; Fogh, C L; Byrne, M A; Roed, J; Goddard, A J H; Hotchkiss, S A M

    2002-02-01

    In nuclear accident consequence assessment, dose contributions from radionuclide deposition on the human body have in the past generally been either ignored or estimated on the basis of rather simple models. Recent experimental work has improved the state of knowledge of relevant processes and parameter ranges. The results presented in this paper represent a first approach to a detailed assessment of doses from radiopollutant deposition on the human body, based on contaminant-specific data. Both the dose to skin from beta-emitters and the whole-body dose from gamma-emitters on body surfaces were found to give potentially significant contributions to dose. Further, skin penetration of some contaminants could lead to significant internal doses.

  8. Spacecraft Maximum Allowable Concentrations for Selected Airborne Contaminants. Volume 5

    NASA Technical Reports Server (NTRS)

    2008-01-01

    To protect space crews from air contaminants, NASA requested that the National Research Council (NRC) provide guidance for developing spacecraft maximum allowable concentrations (SMACs) and review NASA's development of exposure guidelines for specific chemicals. The NRC convened the Committee on Spacecraft Exposure Guidelines to address this task. The committee published Guidelines for Developing Spacecraft Maximum Allowable Concentrations for Space Station Contaminants (NRC 1992). The reason for the review of chemicals in Volume 5 is that many of them have not been examined for more than 10 years, and new research necessitates examining the documents to ensure that they reflect current knowledge. New knowledge can be in the form of toxicologic data or in the application of new approaches for analysis of available data. In addition, because NASA anticipates longer space missions beyond low Earth orbit, SMACs for 1,000-d exposures have also been developed.

  9. Elimination of Airborne Lead Contamination from Caliber .22 Ammunition.

    DTIC Science & Technology

    1987-06-01

    composition is comprised of the toxic heavy metals: lead and barium . The barium , however, is considered a minor contributor to the contamination...lead styphnate priming mixture and 2.9 grains of Winchester (WC371) propellant. This propellant quantity resulted in near the maximum recommended...standard lead styphnate primer mixture to four times the volume of the lead styphnate primer mixture. The amount of new primer mixture which produced

  10. Overview of the risk of respiratory cancer from airborne contaminants

    SciTech Connect

    Speizer, F.E.

    1986-12-01

    This overview on defining risk of respiratory cancer from airborne pollutants summarizes broad issues related to a number of the environmental agents that are discussed in the articles that follow. Lung cancer kills more than 100,000 people annually and is the major form of cancer in both sexes in middle age. Cigarette smoking is the major cause of respiratory cancer and must be taken into account in any study of the effect of an environmental agent on the risk of respiratory cancer, particularly at relatively low levels of excess risk. The agents considered in this series all have the potential for widespread community exposures, either because there is widespread long-term exposure (passive smoking), the agents are direct byproducts of energy consumption (organic particles), have ubiquitous production and use patterns (formaldehyde and fibers), or occur widely in natural settings (radon). Several issues--measurement of exposure, latency, confounding factors and bias, extrapolation from animals to humans, population at risk, and attributable risk--must be considered for each agent. A further issue related to exposure estimates is the relationship of exposure to actual dose. Understanding exposure some 25 to 40 years in the past is important because of the prolonged latency period in the development of respiratory cancers. To the degree that these agents act synergistically with smoking, the reduction of smoking or of exposure to these agents may have greater public health consequences than would be anticipated from the directly measured attributable risk of each of these agents separately.

  11. Molecular contamination and the calibration of AXAF

    NASA Technical Reports Server (NTRS)

    Elsner, R. F.; O'Dell, S. L.; Weisskopf, M. C.

    1993-01-01

    By the end of this decade, the two missions comprising the Advanced X-ray Astrophysics Facility (AXAF) will become the X-ray component of NASA's Great Observatories. In order to meet some of the ambitious scientific objectives, the AXAF team plans to calibrate the telescopes and instruments to an accuracy of a few percent. Particulate and molecular contamination potentially limit this precision, because they would likely change between ground calibration and orbital operation. To avoid this requires careful control over procedures affecting the coated optical surfaces, to ensure that neither particulate nor molecular contamination compromise the calibration. In particular, the fractional areal coverage by particulates or condensed droplets must be less than 0.005 projected onto the aperture plane; the thickness of any molecular film must be less than a few tens of angstrom.

  12. Molecular detection of airborne Coccidioides in Tucson, Arizona.

    PubMed

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

    2016-08-01

    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 detecting Coccidioides 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.

  13. 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.

  14. Fate of Airborne Contaminants in Okefenokee National Wildlife Refuge

    USGS Publications Warehouse

    Winger, P.V.; Lasier, P.J.

    1997-01-01

    weight in liver and kidney, and raccoons (Procyon lotor) >16 ?g/g dry weight in the liver and kidney. Lead averaged 1 ?g/L in rainfall, 6.6 ?g/L in surface water, 9.8 ?g/L in pore water, 12.3 ?g/g in floc and 12.5 ?g/g in sediments. Lead in fish muscle was ~0.1 ?g/g and >1.2 ?g/g in bone, alligator kidney had 1.5 ?g/g lead and liver had 3.8 ?g/g; raccoon kidney and liver averaged about 1 ?g/g. Historical patterns of mercury deposition based on 210Pb aging of the core sample showed mercury increased from pre-1800 concentrations of 500 ng/g in the 1950s, with a subsequent decline to current levels. Lead concentrations in the core sample followed a similar pattern as that of mercury. Okefenokee Swamp serves as a sump for the cations and anions deposited through rainfall. Although mercury and lead levels in the biota are not currently acutely hazardous, concentrations are high enough to cause adverse chronic effects on behavioral, physiological or reproductive functions of resident biota, especially piscivorous species. To protect trust resources associated with the Refuge, activities and developments in the airshed that have the potential to increase atmospheric contamination, especially for lead and mercury, should be curtailed.

  15. Long-term airborne contamination studied by attic dust in an industrial area: Ajka, Hungary

    NASA Astrophysics Data System (ADS)

    Völgyesi, P.; Jordan, G.; Szabo, Cs.

    2012-04-01

    Heavy industrial activities such as mining, metal industry, coal fired power plants have produced large amount of by-products and wide-spread pollution, particularly in the period of centrally dictated economy after WWII, in Hungary. Several studies suggest that significant amount of these pollutants have been deposited in the urban environment. Nowadays, more than half of the world's population is living in urban areas and people spend almost 80% of their lives indoors in developed countries increasing human health risk due to contamination present in urban dwellings. Attic dust sampling was applied to determine the long-term airborne contamination load in the industrial town of Ajka (Hungary). There has been a high industrial activity in Ajka since the end of the 19th century. In addition to aluminum and alumina industry, coal mining, coal fired power plant and glass industry sites, generated numerous waste heaps which act as multi-contamination sources in the area. In October 2010 the Ajka red mud tailings pond failed and caused an accidental regional contamination of international significance. The major objective of this research was to study and map the spatial distribution of heavy metal contamination in airborne attic dust samples. At 27 sampling sites 30 attic dust samples were collected. Sampling strategy followed a grid-based stratified random sampling design. In each cell a house for attic dust sample collection was selected that was located the closest to a randomly generated point in the grid cell. The project area covers a 8x8 grid of 1x1 km cells with a total area of 64 km2. In order to represent long-term industrial pollution, houses with attics kept intact for at least 30-40 years were selected for sampling. Sampling included the collection of background samples remotely placed from the industrialized urban area. The concentration of the major and toxic elements (Al, Ca, Fe, K, Mg, Mn, Na, P, S, and As, Ba, Cd, Co, Cr, Cu, Li, Mo, Ni, Pb, Se, Sn

  16. Molecular Contamination Investigation Facility (MCIF) Capabilities

    NASA Technical Reports Server (NTRS)

    Soules, David M.

    2013-01-01

    This facility was used to guide the development of ASTM E 1559 center dot Multiple Quartz Crystal Microbalances (QCMs), large sample and spectral effects capability center dot Several instrumented, high vacuum chamber systems are used to evaluate the molecular outgassing characteristics of materials, flight components and other sensitive surfaces. Test materials for spacecraft/instrument selection center.Test flight components for acceptable molecular outgas levels center dot Determine time/temperature vacuum bake-out requirements center. Data used to set limits for use of materials and specific components center. Provide Input Data to Contamination Transport Models -Applied to numerous flight projects over the past 20 years.

  17. Computerized Mathematical Models of Spray Washout of Airborne Contaminants (Radioactivity) in Containment Vessels.

    SciTech Connect

    TAM, P. S.

    2003-05-23

    Version 01 Distribution is restricted to the United States Only. SPIRT predicts the washout of airborne contaminants in containment vessels under postulated loss-of-coolant accident (LOCA) conditions. SPIRT calculates iodine removal constants (lambdas) for post-LOCA containment spray systems. It evaluates the effect of the spectrum of drop sizes emitted by the spray nozzles, the effect of drop coalescence, and the precise solution of the time-dependent diffusion equation. STEAM-67 routines are included for calculating the properties of steam and water according to the 1967 ASME Steam Tables.

  18. Effect of airborne contaminants on the wettability of supported graphene and graphite

    NASA Astrophysics Data System (ADS)

    Li, Zhiting; Wang, Yongjin; Kozbial, Andrew; Shenoy, Ganesh; Zhou, Feng; McGinley, Rebecca; Ireland, Patrick; Morganstein, Brittni; Kunkel, Alyssa; Surwade, Sumedh P.; Li, Lei; Liu, Haitao

    2013-10-01

    It is generally accepted that supported graphene is hydrophobic and that its water contact angle is similar to that of graphite. Here, we show that the water contact angles of freshly prepared supported graphene and graphite surfaces increase when they are exposed to ambient air. By using infrared spectroscopy and X-ray photoelectron spectroscopy we demonstrate that airborne hydrocarbons adsorb on graphitic surfaces, and that a concurrent decrease in the water contact angle occurs when these contaminants are partially removed by both thermal annealing and controlled ultraviolet-O3 treatment. Our findings indicate that graphitic surfaces are more hydrophilic than previously believed, and suggest that previously reported data on the wettability of graphitic surfaces may have been affected by unintentional hydrocarbon contamination from ambient air.

  19. Comparison of Air Impaction and Electrostatic Dust Collector Sampling Methods to Assess Airborne Fungal Contamination in Public Buildings.

    PubMed

    Normand, Anne-Cécile; Ranque, Stéphane; Cassagne, Carole; Gaudart, Jean; Sallah, Kankoé; Charpin, Denis-André; Piarroux, Renaud

    2016-03-01

    Many ailments can be linked to exposure to indoor airborne fungus. However, obtaining a precise measurement of airborne fungal levels is complicated partly due to indoor air fluctuations and non-standardized techniques. Electrostatic dust collector (EDC) sampling devices have been used to measure a wide range of airborne analytes, including endotoxins, allergens, β-glucans, and microbial DNA in various indoor environments. In contrast, viable mold contamination has only been assessed in highly contaminated environments such as farms and archive buildings. This study aimed to assess the use of EDCs, compared with repeated air-impactor measurements, to assess airborne viable fungal flora in moderately contaminated indoor environments. Indoor airborne fungal flora was cultured from EDCs and daily air-impaction samples collected in an office building and a daycare center. The quantitative fungal measurements obtained using a single EDC significantly correlated with the cumulative measurement of nine daily air impactions. Both methods enabled the assessment of fungal exposure, although a few differences were observed between the detected fungal species and the relative quantity of each species. EDCs were also used over a 32-month period to monitor indoor airborne fungal flora in a hospital office building, which enabled us to assess the impact of outdoor events (e.g. ground excavations) on the fungal flora levels on the indoor environment. In conclusion, EDC-based measurements provided a relatively accurate profile of the viable airborne flora present during a sampling period. In particular, EDCs provided a more representative assessment of fungal levels compared with single air-impactor sampling. The EDC technique is also simpler than performing repetitive air-impaction measures over the course of several consecutive days. EDC is a versatile tool for collecting airborne samples and was efficient for measuring mold levels in indoor environments.

  20. Destruction of problematic airborne contaminants by hydrogen reduction using a Catalytically Active, Regenerable Sorbent (CARS)

    NASA Technical Reports Server (NTRS)

    Thompson, John O.; Akse, James R.

    1993-01-01

    Thermally regenerable sorbent beds were demonstrated to be a highly efficient means for removal of toxic airborne trace organic contaminants aboard spacecraft. The utilization of the intrinsic weight savings available through this technology was not realized since many of the contaminants desorbed during thermal regeneration are poisons to the catalytic oxidizer or form highly toxic oxidation by-products in the Trace Contaminant Control System (TCCS). Included in this class of compounds are nitrogen, sulfur, silicon, and halogen containing organics. The catalytic reduction of these problematic contaminants using hydrogen at low temperatures (200-300 C) offers an attractive route for their destruction since the by-products of such reactions, hydrocarbons and inorganic gases, are easily removed by existing technology. In addition, the catalytic oxidizer can be operated more efficiently due to the absence of potential poisons, and any posttreatment beds can be reduced in size. The incorporation of the catalyst within the sorbent bed further improves the system's efficiency. The demonstration of this technology provides the basis for an efficient regenerable TCCS for future NASA missions and can be used in more conventional settings to efficiently remove environmental pollutants.

  1. FIELD ACTIVITIES AND PRELIMINARY RESULTS FROM THE INVESTIGATION OF WESTERN AIRBORNE CONTAMINANTS IN TWO HIGH ELEVATION WATERSHEDS OF ROCKY MOUNTAIN NATIONAL PARK

    EPA Science Inventory

    The National Park Service initiated the Western Airborne Contaminants Assessment Project (WACAP) in 2002 to determine if airborne contaminants from long-range transport and/or regional sources are having an impact on remote western ecosystems, including AK. Rocky Mountain Nation...

  2. Presence of airborne contaminants in the wildlife of northern Québec.

    PubMed

    Langlois, C; Langis, R

    1995-01-15

    As part of the environmental impact studies of the Great Whale and the Nottaway-Broadback-Rupert (NBR) hydroelectric projects, Hydro-Québec collected data on the occurrence and levels of several contaminants present in wildlife from both regions between 1989 and 1991. The analyses performed included metals (mercury, arsenic, selenium, cadmium, lead, nickel and copper), polychlorinated biphenyls (PCBs as arochlors or the sum of 20-40 congeners) and organochlorine pesticides such as hexachlorobenzene (HCB), DDT, DDE, hexachlorocyclohexane (HCH), chlordane, mirex and dieldrin. Species sampled included fish (freshwater and marine), birds (waterfowl, gull and ptarmigan), terrestrial mammals (marten, mink and hare) and marine mammals (freshwater and marine seals, belugas). Most laboratory analyses were carried out on both muscle and liver tissues, but some were conducted on other tissues as well: feathers, eggs and blubber. The results indicate that numerous airborne contaminants were present in the wildlife of both the Great Whale and the NBR study areas and that their level of contamination was similar to that of other northern environments. Total mercury in muscle was high in piscivorous fish, birds and mammals (terrestrial and marine). We observed significant levels of cadmium and lead in the livers of some herbivorous terrestrial animals, such as ptarmigans and hares. Among the organochlorine contaminants analyzed, levels of PCBs and DDE in piscivorous birds (mergansers and loons) and in marine mammals (seals and belugas) were high. For some contaminants, such as mercury, cadmium, lead, PCBs and DDE, the levels observed in some species or tissues could be considered worrisome with regard to public health, if those species or tissues constitute an important part of traditional native diets.

  3. Metal and Metalloid Contaminants in Airborne Dust Associated with Mining Operations

    NASA Astrophysics Data System (ADS)

    Betterton, E. A.; Csavina, J. L.; Field, J. P.; Landázuri, A. C.; Felix Villar, O.; Rine, K. P.; Sáez, A.; Pence, J.; Shayan, H.; Russell, M.

    2011-12-01

    Mining operations are potential sources of airborne metal and metalloid contaminants through both direct smelter emissions and wind erosion of mine tailings. The warmer, drier conditions predicted for the Southwestern US by climate models may make contaminated atmospheric dust and aerosols increasingly important, with potential deleterious effects on human health and ecology. In this work, we report the size-resolved chemical characterization of atmospheric aerosols sampled near an inactive Superfund site and at an active mining and smelting site in Arizona. Aerosols were characterized with 10-stage (0.054 to 18 μm aerodynamic diameter) multiple orifice uniform deposit impactors (MOUDI), Dustrack monitors, and total suspended particulate (TSP) collectors. The MOUDI results show that arsenic and lead concentrations follow a bimodal distribution, with maxima centered at approximately 0.3 and 7.0 μm aerodynamic diameter. We hypothesize that the sub-micron arsenic and lead are the product of condensation and coagulation of smelting vapors. In the coarse size, contaminants are thought to originate as aeolian dust from mine tailings and other sources.

  4. Deposition and accumulation of airborne organic contaminants in Yosemite National Park, Calfornia

    USGS Publications Warehouse

    Mast, Alisa M.; Alvarez, David A.; Zaugg, Steven D.

    2012-01-01

    Deposition and accumulation of airborne organic contaminants in Yosemite National Park were examined by sampling atmospheric deposition, lichen, zooplankton, and lake sediment at different elevations. Passive samplers were deployed in high-elevation lakes to estimate surface-water concentrations. Detected compounds included current-use pesticides chlorpyrifos, dacthal, and endosulfans and legacy compounds chlordane, dichlorodiphenyltrichloroethane-related compounds, dieldrin, hexachlorobenzene, and polychlorinated biphenyls. Concentrations in snow were similar among sites and showed little variation with elevation. Endosulfan concentrations in summer rain appeared to coincide with application rates in the San Joaquin Valley. More than 70% of annual pesticide inputs from atmospheric deposition occurred during the winter, largely because most precipitation falls as snow. Endosulfan and chlordane concentrations in lichen increased with elevation, indicating that mountain cold-trapping might be an important control on accumulation of these compounds. By contrast, chlorpyrifos concentrations were inversely correlated with elevation, indicating that distance from source areas was the dominant control. Sediment concentrations were inversely correlated with elevation, possibly because of the organic carbon content of sediments but also perhaps the greater mobility of organic contaminants at lower elevations. Surface-water concentrations inferred from passive samplers were at sub-parts-per-trillion concentrations, indicating minimal exposure to aquatic organisms from the water column. Concentrations in sediment generally were low, except for dichlorodiphenyldichloroethane in Tenaya Lake, which exceeded sediment guidelines for protection of benthic organisms.

  5. Modeling breathing-zone concentrations of airborne contaminants generated during compressed air spray painting.

    PubMed

    Flynn, M R; Gatano, B L; McKernan, J L; Dunn, K H; Blazicko, B A; Carlton, G N

    1999-01-01

    This paper presents a mathematical model to predict breathing-zone concentrations of airborne contaminants generated during compressed air spray painting in cross-flow ventilated booths. The model focuses on characterizing the generation and transport of overspray mist. It extends previous work on conventional spray guns to include exposures generated by HVLP guns. Dimensional analysis and scale model wind-tunnel studies are employed using non-volatile oils, instead of paint, to produce empirical equations for estimating exposure to total mass. Results indicate that a dimensionless breathing zone concentration is a nonlinear function of the ratio of momentum flux of air from the spray gun to the momentum flux of air passing through the projected area of the worker's body. The orientation of the spraying operation within the booth is also very significant. The exposure model requires an estimate of the contaminant generation rate, which is approximated by a simple impactor model. The results represent an initial step in the construction of more realistic models capable of predicting exposure as a mathematical function of the governing parameters.

  6. Evaluation of bioaerosol components, generation factors, and airborne transport associated with lime treatment of contaminated sediment.

    PubMed

    Barth, Edwin F; Reponen, Tiina; Succop, Paul

    2009-05-01

    Lime treatment has been used in contaminated sediment management activities for many purposes such as dewatering, improvement of physical properties, and reducing contaminant mobility. Exothermic volatilization of volatile organic compounds from lime-treated sediment is well known, but potential aerosolization of bioaerosol components has not been evaluated. A physical model of a contaminated sediment treatment and airborne transport process and an experimental protocol were developed to identify specific bioaerosol components (bacteria, fungi, cell structural components, and particles) that may be aerosolized and transported. Key reaction variables (amount of lime addition, rate of lime addition, mixing energy supplied) that may affect the aerosolization of bioaerosol components were evaluated. Lime treatment of a sediment contaminated with heavy metals, petroleum-based organics, and microorganisms increased the sediment pH and solids content. Lime treatment reduced the number of water-extractable bacteria and fungi in the sediment from approximately 10(6) colony-forming units (CFU) x mL(-1) to less than the detection limit of 10(3) CFU x mL(-1). This reduction was seen immediately for bacteria and within 21 days for fungi. Lime treatment immediately reduced the amount of endotoxin in the sediment, but the effects of lime treatment on beta-D-glucan could not be determined. The temperature of the treated sediment was linearly related to the amount of lime added within the range of 0-25%. Bacteria were aerosolized during the treatment trials, but there was no culturable evidence of aerosolization of fungi, most likely because of either their particular growth stage or relatively larger particle size that reduced their aerosolization potential and their collection into the impingers. Nonbiological particles, endotoxin, and beta-D-glucan were not detected in air samples during the treatment trials. The amount of lime added to the reaction beaker and the relative

  7. The bedding of laboratory animals as a source of airborne contaminants.

    PubMed

    Kaliste, E; Linnainmaa, M; Meklin, T; Torvinen, E; Nevalainen, A

    2004-01-01

    In work environments with laboratory animals, the bedding of animals binds the excreta as well as other compounds originating from the animals and their environment. These may be generated into the ambient air when the personnel handle bedding in different procedures. This study compares the dustiness of different types of six clean and four soiled beddings from rat or mouse cages. The dust generation of clean bedding varied from <1 to 25 mg/m(3). When used in the cages of rats or mice for 4 days, the dust concentration of the beddings decreased, increased or stayed the same, depending on the type of bedding and animal species. A decrease in dustiness was, however, more common. The levels in the soiled beddings varied from <1 to 8.6 mg/m(3). In the case of the aspen chip bedding, the contents of bedding used in mouse, rat or rabbit cages were analysed for mesophilic bacteria and fungi, mycobacteria and endotoxins. All of these contaminants were variably found in the bedding samples, the maximal concentrations for bacteria were >6 500 000 colony-forming units (cfu)/g, for fungi 212 000 cfu/g, and for endotoxins 6500 ng/g (81 000 EU/g). The results showed that the bedding of laboratory animals may contain biologically effective compounds, and that these may be distributed into the ambient air depending on the characteristics of the bedding material. The dustiness of different bedding types is an important factor affecting the amount and quality of the occupational exposure of the personnel to airborne contaminants.

  8. Occupational airborne contamination in south Brazil: 1. Oxidative stress detected in the blood of coal miners.

    PubMed

    Avila Júnior, S; Possamai, F P; Budni, P; Backes, P; Parisotto, E B; Rizelio, V M; Torres, M A; Colepicolo, P; Wilhelm Filho, D

    2009-11-01

    Reactive oxygen species and nitrogen species have been implicated in the pathogenesis of coal dust-induced toxicity. The present study investigated several oxidative stress biomarkers (Contents of lipoperoxidation = TBARS, reduced = GSH, oxidized = GSSG and total glutathione = TG, alpha-tocopherol, and the activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in the blood of three different groups (n = 20 each) exposed to airborne contamination associated with coal mining activities: underground workers directly exposed, surface workers indirectly exposed, residents indirectly exposed (subjects living near the mines), and controls (non-exposed subjects). Plasma TBARS were increased and whole blood TG and GSH levels were decreased in all groups compared to controls. Plasma alpha-tocopherol contents showed approximately half the values in underground workers compared to controls. GST activity was induced in workers and also in residents at the vicinity of the mining plant, whilst CAT activity was induced only in mine workers. SOD activity was decreased in all groups examined, while GPx activity showed decreased values only in underground miners, and GR did not show any differences among the groups. The results showed that subjects directly and indirectly exposed to coal dusts face an oxidative stress condition. They also indicate that people living in the vicinity of the mine plant are in health risk regarding coal mining-related diseases.

  9. Determination of molecular contamination performance for space chamber tests

    NASA Technical Reports Server (NTRS)

    Scialdone, J. J.

    1973-01-01

    The limitations of chamber tests with regard to the molecular contamination of a spacecraft undergoing vacuum test were examined. The molecular flow conditions existing in the chamber and the parameters dictating the degree of contamination were analyzed. Equations and graphs were developed to show the fraction of molecules returning to the spacecraft out of those emitted and to show other chamber flow parameters as a function of chamber and spacecraft surface molecular pumping and geometric configuration. Type and location of instruments required to measure the outgassing, the degree of contamination, and the returning flows are also discussed.

  10. Molecular contamination study by interaction of a molecular beam with a platinum surface

    NASA Technical Reports Server (NTRS)

    Nuss, H. E.

    1976-01-01

    The capability of molecular beam scattering from a solid surface is analyzed for identification of molecular contamination of the surface. The design and setup of the molecular beam source and the measuring setup for the application of a phase sensitive measuring technique for the determination of the scattered beam intensity are described. The scattering distributions of helium and nitrogen molecular beams interacting with a platinum surface were measured for different amounts of contamination from diffusion pump oil for surface temperatures ranging from 30 to 400 C. The results indicate the scattering of molecular beams from a platinum surface is a very sensitive method for detecting surface contamination.

  11. Monitoring personal, indoor, and outdoor exposures to metals in airborne particulate matter: Risk of contamination during sampling, handling and analysis

    NASA Astrophysics Data System (ADS)

    Rasmussen, Pat E.; Wheeler, Amanda J.; Hassan, Nouri M.; Filiatreault, Alain; Lanouette, Monique

    Rigorous sampling and quality assurance protocols are required for the reliable measurement of personal, indoor and outdoor exposures to metals in fine particulate matter (PM 2.5). Testing of five co-located replicate air samplers assisted in identifying and quantifying sources of contamination of filters in the laboratory and in the field. A field pilot study was conducted in Windsor, Ont., Canada to ascertain the actual range of metal content that may be obtained on filter samples using low-flow (4 L min -1) 24-h monitoring of personal, indoor and outdoor air. Laboratory filter blanks and NIST certified reference materials were used to assess contamination, instrument performance, accuracy and precision of the metals determination. The results show that there is a high risk of introducing metal contamination during all stages of sampling, handling and analysis, and that sources and magnitude of contamination vary widely from element to element. Due to the very small particle masses collected on low-flow 24-h filter samples (median 0.107 mg for a sample volume of approximately 6 m 3) the contribution of metals from contamination commonly exceeds the content of the airborne particles being sampled. Thus, the use of field blanks to ascertain the magnitude and variability of contamination is critical to determine whether or not a given element should be reported. The results of this study were incorporated into standard operating procedures for a large multiyear personal, indoor and outdoor air monitoring campaign in Windsor.

  12. Importance of subaerial biofilms and airborne microflora in the deterioration of stonework: a molecular study.

    PubMed

    Polo, Andrea; Gulotta, Davide; Santo, Nadia; Di Benedetto, Cristiano; Fascio, Umberto; Toniolo, Lucia; Villa, Federica; Cappitelli, Francesca

    2012-01-01

    The study characterized the sessile microbial communities on mortar and stone in Milan University's Richini's Courtyard and investigated the relationship between airborne and surface-associated microbial communities. Active colonization was found in three locations: green and black patinas were present on mortar and black spots on stone. Confocal laser scanning microscopy, scanning electron microscopy and culture-independent molecular methods revealed that the biofilm causing deterioration was dominated by green algae and black fungi. The mortar used for restoration contained acrylic and siloxane resins that could be used by microorganisms as carbon and energy sources thereby causing proliferation of the biofilm. Epifluorescence microscopy and culture-based methods highlighted a variety of airborne microflora. Bacterial and fungal counts were quantitatively similar to those reported in other investigations of urban areas, the exception being fungi during summer (1-2 orders of magnitude higher). For the first time in the cultural heritage field, culture-independent molecular methods were used to resolve the structure of airborne communities near discoloured surfaces, and to investigate the relationship between such communities and surface-associated biofilms.

  13. Optical Characterization of Molecular Contaminant Films

    NASA Technical Reports Server (NTRS)

    Visentine, James T.

    2007-01-01

    A semi-empirical method of optical characterization of thin contaminant films on surfaces of optical components has been conceived. The method was originally intended for application to films that become photochemically deposited on such optical components as science windows, lenses, prisms, thinfilm radiators, and glass solar-cell covers aboard spacecraft and satellites in orbit. The method should also be applicable, with suitable modifications, to thin optical films (whether deposited deliberately or formed as contaminants) on optical components used on Earth in the computer microchip laser communications and thin-film industries. The method is expected to satisfy the need for a means of understanding and predicting the reductions in spectral transmittance caused by contaminant films and the consequent deterioration of performances of sensitive optical systems. After further development, this method could become part of the basis of a method of designing optical systems to minimize or compensate for the deleterious effects of contaminant films. In the original outer-space application, these deleterious effects are especially pronounced because after photochemical deposition, the films become darkened by further exposure to solar vacuum ultraviolet (VUV) radiation. In this method, thin contaminant films are theoretically modeled as thin optical films, characterized by known or assumed values of thickness, index of refraction, and absorption coefficient, that form on the outer surfaces of the original antireflection coating on affected optical components. The assumed values are adjusted as needed to make actual spectral transmittance values approximate observed ones as closely as possible and to correlate these values with amounts of VUV radiation to which the optical components have been exposed. In an initial study, the method was applied in correlating measured changes in transmittance of high-purity fused silica photochemically coated with silicone films of

  14. Analysis of Molecular Contamination on Genesis Collectors Through Spectroscopic Ellipsometry

    NASA Technical Reports Server (NTRS)

    McNamara, K. M.; Stansbery, Eileen K.

    2005-01-01

    Before the spacecraft returned to Earth in September, the Genesis mission had a preliminary assessment plan in place for the purpose of providing information on the condition and availability of collector materials to the science community as a basis for allocation requests. One important component of that plan was the evaluation of collector surfaces for molecular contamination. Sources of molecular contamination might be the on-orbit outgassing of spacecraft and science canister components, the condensation of thruster by-products during spacecraft maneuvers, or the condensation of volatile species associated with reentry. Although the non-nominal return of the Genesis spacecraft introduced particulate contamination to the collectors, such as dust and heatshield carbon-carbon, it is unlikely to have caused any molecular deposition. The contingency team's quick action in returning the damaged payload the UTTR cleanroom by 6 PM the evening of recovery help to ensure that exposure to weather conditions and the environment were kept to a minimum.

  15. EVALUATION OF BIOAEROSOL COMPONENTS, GENERATION FACTORS, AND AIRBORNE TRANSPORT ASSOCIATED WITH LIME TREATMENT OF CONTAMINATED SEDIMENT

    EPA Science Inventory

    Lime treatment has been used in contaminated sediment management activities for many purposes such as dewatering, improvement of physical properties, and reducing contaminant mobility. Exothermic volatilization of volatile organic compounds from lime-treated sediment is well kno...

  16. Molecular detection of bacterial contamination in gnotobiotic rodent units

    PubMed Central

    Packey, Christopher D; Shanahan, Michael T; Manick, Sayeed; Bower, Maureen A; Ellermann, Melissa; Tonkonogy, Susan L; Carroll, Ian M; Sartor, R Balfour

    2013-01-01

    Gnotobiotic rodents provide an important technique to study the functional roles of commensal bacteria in host physiology and pathophysiology. To ensure sterility, these animals must be screened frequently for contamination. The traditional screening approaches of culturing and Gram staining feces have inherent limitations, as many bacteria are uncultivable and fecal Gram stains are difficult to interpret. Thus, we developed and validated molecular methods to definitively detect and identify contamination in germ-free (GF) and selectively colonized animals. Fresh fecal pellets were collected from rodents housed in GF isolators, spontaneously contaminated ex-GF isolators, selectively colonized isolators and specific pathogen-free (SPF) conditions. DNA isolated from mouse and rat fecal samples was amplified by polymerase chain reaction (PCR) and subjected to quantitative PCR (qPCR) using universal primers that amplify the 16S rRNA gene from all bacterial groups. PCR products were sequenced to identify contaminating bacterial species. Random amplification of polymorphic DNA (RAPD) PCR profiles verified bacterial inoculation of selectively colonized animals. These PCR techniques more accurately detected and identified GF isolator contamination than current standard approaches. These molecular techniques can be utilized to more definitively screen GF and selectively colonized animals for bacterial contamination when Gram stain and/or culture results are un-interpretable or inconsistent. PMID:23887190

  17. Geltape method for measurement of work related surface contamination with cobalt containing dust: correlation between surface contamination and airborne exposure.

    PubMed Central

    Poulsen, O M; Olsen, E; Christensen, J M; Vinzent, P; Petersen, O H

    1995-01-01

    OBJECTIVES--The geltape method is a new method for optical measurement of total amount of dust on surfaces. The objectives were to study the potential applicability of this method to measurements of work related cobalt exposure during painting of plates with cobalt dye. METHODS--Consecutive series of work related geltape prints were taken from surfaces inside and outside the ventilation cabins of two plate painters during two full working days. The amount of dust picked up by the geltapes was measured optically with a field monitor. Also, personal air samples were collected on filters at the different work processes. In the laboratory the contents of cobalt on the geltape prints and the filters were measured with inductive coupled plasma atomic emission spectroscopy. RESULTS--The key results were: (a) when the geltape prints were taken from surfaces inside the cabins the optically measured area of the geltapes covered with total dust (area (%)) correlated well with the chemically measured amount of cobalt present on the geltapes. Linear correlation coefficient (R2) was 0.91 for geltape prints taken on the floor and 0.94 for prints taken on the ceiling; (b) the cumulative airborne cobalt exposure, calculated from data on work related exposure by personal sampling, correlated with the area (%) of geltape prints taken from the ceiling of the cabin (R2 = 0.98); (c) the geltape method could be used to distinguish both between work processes with different levels of cobalt exposure, and between plate painters subjected to significant differences in airborne cobalt exposure. CONCLUSION--The geltape method could produce measures of the work related exposures as well as whole day exposure for cobalt. The geltape results correlated with measurements of personal airborne cobalt exposure. In this industry the profile of exposure is well-defined in time, and it seems reasonable to apply this fast and low cost method in routine exposure surveillance to obtain a more detailed

  18. Statistical Evaluation of Molecular Contamination During Spacecraft Thermal Vacuum Test

    NASA Technical Reports Server (NTRS)

    Chen, Philip; Hedgeland, Randy; Montoya, Alex; Roman-Velazquez, Juan; Dunn, Jamie; Colony, Joe; Petitto, Joseph

    1998-01-01

    The purpose of this paper is to evaluate the statistical molecular contamination data with a goal to improve spacecraft contamination control. The statistical data was generated in typical thermal vacuum tests at the National Aeronautics and Space Administration, Goddard Space Flight Center (GSFC). The magnitude of material outgassing was measured using a Quartz Crystal Microbalance (QCM) device during the test. A solvent rinse sample was taken at the conclusion of each test. Then detailed qualitative and quantitative measurements were obtained through chemical analyses. All data used in this study encompassed numerous spacecraft tests in recent years.

  19. Statistical Evaluation of Molecular Contamination During Spacecraft Thermal Vacuum Test

    NASA Technical Reports Server (NTRS)

    Chen, Philip; Hedgeland, Randy; Montoya, Alex; Roman-Velazquez, Juan; Dunn, Jamie; Colony, Joe; Petitto, Joseph

    1997-01-01

    The purpose of this paper is to evaluate the statistical molecular contamination data with a goal to improve spacecraft contamination control. The statistical data was generated in typical thermal vacuum tests at the National Aeronautics and Space Administration, Goddard Space Flight Center (GSFC). The magnitude of material outgassing was measured using a Quartz Crystal Microbalance (QCM) device during the test. A solvent rinse sample was taken at the conclusion of the each test. Then detailed qualitative and quantitative measurements were obtained through chemical analyses. All data used in this study encompassed numerous spacecraft tests in recent years.

  20. Statistical Evaluation of Molecular Contamination During Spacecraft Thermal Vacuum Test

    NASA Technical Reports Server (NTRS)

    Chen, Philip; Hedgeland, Randy; Montoya, Alex; Roman-Velazquez, Juan; Dunn, Jamie; Colony, Joe; Petitto, Joseph

    1999-01-01

    The purpose of this paper is to evaluate the statistical molecular contamination data with a goal to improve spacecraft contamination control. The statistical data was generated in typical thermal vacuum tests at the National Aeronautics and Space Administration, Goddard Space Flight Center (GSFC). The magnitude of material outgassing was measured using a Quartz Crystal Microbalance (QCNO device during the test. A solvent rinse sample was taken at the conclusion of each test. Then detailed qualitative and quantitative measurements were obtained through chemical analyses. All data used in this study encompassed numerous spacecraft tests in recent years.

  1. Effect of Ventilation on Occupational Exposure to Airborne Biological Contaminants in an Isolation Room

    PubMed Central

    Jafari, Mohammad Javad; Omidi, Leila; Jafari, Mina; Tabarsi, Payam; Salehpour, Soussan; Amiri, Zohre

    2015-01-01

    Background: Airborne pathogens play an important role in a hospital air quality. Respiratory infections are the most common occupational disease among the health care staff. The aim of this study was to determine the effect of ventilation system parameters and patient bed arrangements on concentration of airborne pathogens in indoor air of an isolation room. Materials and Methods: A single-bed room was considered in which a patient diagnosed with tuberculosis had been admitted. Five different ventilation types, each at four different capacities were installed in the room while two different locations for the patient’s bed were assessed. A direct-impact sampling method (blood agar plate) was used in order to determine the intensity of the bio-aerosols in indoor air of the isolation room. Results: The results showed that when the air was supplied through a circular vent located on the northern wall and the vented air was exhausted via a linear vent located on the southern wall, the average concentration of the bio-aerosols in the air, (with 12 air changes per hour) was reduced to 25 colonies per cubic meter (cfu/m3) (in the range of 25–88 cfu/m3 and a 95 percent confidence interval). In accordance with the analysis applied upon the two different locations of the bed, no significant difference was observed (P>0.05). Conclusion: Installation of ventilation systems as determined by the study is recommended for tuberculosis isolation rooms. PMID:26528369

  2. Air-borne microbial contamination of surfaces in a UK dental clinic.

    PubMed

    Decraene, Valérie; Ready, Derren; Pratten, Jonathan; Wilson, Michael

    2008-08-01

    Little is known about the number, type, or antibiotic resistance profiles, of air-borne microbes present in hospital settings yet such information is important in designing effective measures to reduce cross-infection. In this study settle plates were used to identify and quantify the air-borne microbes present in a dental clinic. All isolates were identified to species level using partial 16S ribosomal RNA gene sequencing and their susceptibility to ampicillin, chloramphenicol, erythromycin, gentamicin, penicillin, tetracycline or vancomycin was performed. The mean numbers of viable bacteria detected for each sampling occasion during periods of clinical activity and in the absence of such activity were 21.9 x 10(2 )cfu/m2/h and 2.3 x 10(2 )cfu/m2/h respectively. One hundred ninety-three distinct colony morphotypes, comprising 73 species, were isolated during the study and 48% of these were resistant to at least one antibiotic. The mean numbers of different morphotypes detected per sampling occasion were 14.3 and 5 during periods of clinical activity and inactivity respectively. Propionibacterium acnes, Micrococcus luteus and Staphylococcus epidermidis were frequently isolated regardless of whether any clinical activities were taking place. These findings highlight the importance of preventing surfaces from becoming reservoirs of antibiotic-resistant bacteria and thereby contributing to cross-infection in the dental clinic.

  3. Airborne concentrations of trivalent and hexavalent chromium from contaminated soils at unpaved and partially paved commercial/industrial sites

    SciTech Connect

    Falerios, M.; Schild, K. ); Sheehan, P.; Paustenbach, D.J. )

    1992-01-01

    This method described was used to quantify airborne Cr(VI) levels at both indoor and outdoor locations at 21 sites in Hudson County, New Jersey which have soils containing chromite ore processing residue. Of the 21 sites evaluated, nine were unpaved or partially paved industrial/commercial sites or roadways with a moderate to high level of heavy truck traffic. Most of the remainder were commercial facilities with partially paved or unpaved parking lots and only light vehicle traffic. In addition, 15 residential sites in the area which do not have contaminated soil were sampled to characterized background levels of Cr(VI). The overall arithmetic mean values for indoor and outdoor Cr(VI) in total suspended particulates at the 12 industrial sites were 3.0 ng/m{sup 3} and 9.9ng/m{sup 3}, respectively. The indoor Cr(VI) concentrations measured at the 15 residential sites ranged from 0.38 to 3.3 ng/m{sup 3}. Airborne Cr(VI) levels outdoors at sites with chromite ore residue appear to be primarily influenced by the level of local vehicle traffic. Measured outdoor concentrations at sites with light vehicle traffic were generally low, within the range of levels measured indoors at the residential sites, and not strongly influenced by Cr(VI) concentrations in surface soils. At sites with a high rate of vehicle traffic, outdoor Cr(VI) concentrations exceeded background levels only on days when surface soils were dry. The average concentrations measured at these sites were more than 5,000-times lower than the current occupational exposure limit for Cr(VI) (TLV = 0.05 mg/m{sup 3}).

  4. DISTRIBUTIONS OF AIRBORNE AGRICULTURAL CONTAMINANTS RELATIVE TO AMPHIBIAN POPULATIONS IN THE SOUTHERN SIERRA NEVADA, CA

    EPA Science Inventory

    The Sierra Nevada mountain range lies adjacent to one of the heaviest pesticide use areas in the USA, the Central Valley of California. Because of this proximity, concern has arisen that agricultural pesticides, in addition to other contaminants, are adversely affecting the natur...

  5. [A new application for the human whole blood test: development of an assay to assess the health risk of air-borne microbial contaminations].

    PubMed

    Fennrich, S; Zucker, B; Hartung, T

    2001-01-01

    The pathogenic properties of environmental microorganisms as well as pyrogens as fragments of those bacteria (especially endotoxins) for humans is increasingly recognised. Various clinical syndromes are described after contact with airborne microbial contaminants via the respiratory tract: Sick-building-syndrome, humidifier lung (a form of hypersensitive pneumonitis), "Monday sickness" etc. Air-conditioning and ventilation systems intensify this problem as well as storage of compost within the household which represents a considerable source of airborne pollutants. In 1995 a new method for the detection of pyrogenic (fever-inducing) hazardous substances was described by Hartung and Wendel. This whole blood assay utilises the natural reaction of the immune system in order to detect a broad spectrum of pyrogens very sensitively in the relevant species. Injectable drugs are the main area of application in which this innovative test has already proven effective and is currently validated for inclusion into European Pharmacopoeia. In co-operation with the FU Berlin we could demonstrate in ventilation systems in animal stables that the whole blood pyrogen test can also detect airborne environmental microorganisms very sensitively. The filtration technique for collection of these germs is an established method for air-conditioning and ventilation systems. In co-operation with the FU Berlin (Institut für Tier-und Umwelthygiene) and the filter producer Sartorius this method is currently developed for the detection of airborne contaminations.

  6. Airborne PCB as a contamination risk on freeze-drying of sediment.

    PubMed

    Söderström, Maria; Nylund, Kerstin; Järnberg, Ulf; Alsberg, Tomas; Asplund, Lillemor

    2005-01-01

    In a study of polychlorinated biphenyls (PCB) in freeze-dried sediments from Swedish lakes, the samples were found to contain unexpectedly high concentrations of PCBs. In one of the lakes (Björken), e.g. the concentration of PCB-28 was found to be 189 ng/g dw after freeze-drying compared to 7 ng/g dw after air-drying of the sediment and therefore our hypothesis was that the contamination had occurred during the freeze-drying procedure. Hence, a dry reference sediment (RS) was used in order to identify potential sources of PCB contamination. The investigation included freeze-drying of the dry RS in five different laboratories, exposure to the air in the freeze-drying room, storage at room temperature and air-drying in a certain fume hood and in a laminar flow clean bench. The pattern and concentrations of PCBs detected in the exposed RS were strongly influenced by low chlorinated PCB congeners under all of these conditions with exception for air-drying in the fume hood. Storage in the laboratory air resulted in a slight elevation in the concentrations of low chlorinated PCB congeners, whereas higher concentrations of all PCB congeners were observed after freeze-drying. In all experiments the contamination appeared to be due to adsorption of PCB from the laboratory air. On the basis of these findings we recommend that reference material be subjected to the entire procedure, including sample preparation, in order to monitor contamination and that a procedure involving solvent extraction of wet sediment samples is used, whenever possible, instead of procedures involving dry samples.

  7. Loading and unloading of freeze-dryers: airborne contamination risks for aseptically manufactured sterile drug products.

    PubMed

    Ljungqvist, Bengt; Reinmüller, Berit

    2007-01-01

    In pharmaceutical manufacturing, freeze-drying processes can be adversely affected by temperature differences relative to the surrounding air. Loading and unloading of freeze-dryers are performed either without or with temperature differences between the cleanroom and the chamber of the freeze-dryer. This operation can cause a flow of room air through the opening, creating a contamination risk, especially when manual handling of material is performed in this area. To minimize this risk, a high-efficiency particulate air (HEPA) filter unit should be installed above the opening to provide clean air and protect the opening. Here the theoretical relationships are discussed and design criteria are presented.

  8. TRACKING FECAL CONTAMINATION WITH BACTEROIDALES MOLECULAR MARKERS: AN ANALYSIS OF THE DYNAMICS OF FECAL CONTAMINATION IN THE TILLAMOOK BASIN, OREGON

    EPA Science Inventory

    Although amplification of source-specific molecular markers from Bacteroidales fecal bacteria can identify several different kinds of fecal contamination in water, it remains unclear how this technique relates to fecal indicator measurements in natural waters. The objectives of t...

  9. Evaluation of airborne geophysical surveys for large-scale mapping of contaminated mine pools: draft final report

    SciTech Connect

    Hammack, R. W.

    2006-12-28

    Decades of underground coal mining has left about 5,000 square miles of abandoned mine workings that are rapidly filling with water. The water quality of mine pools is often poor; environmental regulatory agencies are concerned because water from mine pools could contaminate diminishing surface and groundwater supplies. Mine pools are also a threat to the safety of current mining operations. Conversely, mine pools are a large, untapped water resource that, with treatment, could be used for a variety of industrial purposes. Others have proposed using mine pools in conjunction with heat pumps as a source of heating and cooling for large industrial facilities. The management or use of mine pool water requires accurate maps of mine pools. West Virginia University has predicted the likely location and volume of mine pools in the Pittsburgh Coalbed using existing mine maps, structure contour maps, and measured mine pool elevations. Unfortunately, mine maps only reflect conditions at the time of mining, are not available for all mines, and do not always denote the maximum extent of mining. Since 1999, the National Energy Technology Laboratory (NETL) has been evaluating helicopter-borne, electromagnetic sensing technologies for the detection and mapping of mine pools. Frequency domain electromagnetic sensors are able to detect shallow mine pools (depth < 50 m) if there is sufficient contrast between the conductance of the mine pool and the conductance of the overburden. The mine pools (conductors) most confidently detected by this technology are overlain by thick, resistive sandstone layers. In 2003, a helicopter time domain electromagnetic sensor was applied to mined areas in southwestern Virginia in an attempt to increase the depth of mine pool detection. This study failed because the mine pool targets were thin and not very conductive. Also, large areas of the surveys were degraded or made unusable by excessive amounts of cultural electromagnetic noise that obscured the

  10. Growth of desferrioxamine-deficient Streptomyces mutants through xenosiderophore piracy of airborne fungal contaminations.

    PubMed

    Arias, Anthony Argüelles; Lambert, Stéphany; Martinet, Loïc; Adam, Delphine; Tenconi, Elodie; Hayette, Marie-Pierre; Ongena, Marc; Rigali, Sébastien

    2015-07-01

    Due to the necessity of iron for housekeeping functions, nutrition, morphogenesis and secondary metabolite production, siderophore piracy could be a key strategy in soil and substrate colonization by microorganisms. Here we report that mutants of bacterium Streptomyces coelicolor unable to produce desferrioxamine siderophores could recover growth when the plates were contaminated by indoor air spores of a Penicillium species and Engyodontium album. UPLC-ESI-MS analysis revealed that the HPLC fractions with the extracellular 'resuscitation' factors of the Penicillium isolate were only those that contained siderophores, i.e. Fe-dimerum acid, ferrichrome, fusarinine C and coprogen. The restored growth of the Streptomyces mutants devoid of desferrioxamine is most likely mediated through xenosiderophore uptake as the cultivability depends on the gene encoding the ABC-transporter-associated DesE siderophore-binding protein. That a filamentous fungus allows the growth of desferrioxamine non-producing Streptomyces in cocultures confirms that xenosiderophore piracy plays a vital role in nutritional interactions between these taxonomically unrelated filamentous microorganisms.

  11. Evaluation of the area factor used in the RESRAD code for the estimation of airborne contaminant concentrations of finite area sources

    SciTech Connect

    Chang, Y.S.; Yu, C.; Wang, S.K.

    1998-07-01

    The area factor is used in the RESRAD code to estimate the airborne contaminant concentrations for a finite area of contaminated soils. The area factor model used in RESRAD version 5.70 and earlier (referred to as the old area factor) was a simple, but conservative, mixing model that tended to overestimate the airborne concentrations of radionuclide contaminants. An improved and more realistic model for the area factor (referred to here as the new area factor) is described in this report. The new area factor model is designed to reflect site-specific soil characteristics and meteorological conditions. The site-specific parameters considered include the size of the source area, average particle diameter, and average wind speed. Other site-specific parameters (particle density, atmospheric stability, raindrop diameter, and annual precipitation rate) were assumed to be constant. The model uses the Gaussian plume model combined with contaminant removal processes, such as dry and wet deposition of particulates. Area factors estimated with the new model are compared with old area factors that were based on the simple mixing model. In addition, sensitivity analyses are conducted for parameters assumed to be constant. The new area factor model has been incorporated into RESRAD version 5.75 and later.

  12. Sick building syndrome: Acute illness among office workers--the role of building ventilation, airborne contaminants and work stress

    SciTech Connect

    Letz, G.A. )

    1990-05-01

    Outbreaks of acute illness among office workers have been reported with increasing frequency during the past 10-15 years. In the majority of cases, hazardous levels of airborne contaminants have not been found. Generally, health complaints have involved mucous membrane and respiratory tract irritation and nonspecific symptoms such as headache and fatigue. Except for rare examples of hypersensitivity pneumonitis related to microbiologic antigens, there have been no reports of serious morbidity or permanent sequelae. However, the anxiety, lost work time, decreased productivity and resources spent in investigating complaints has been substantial. NIOSH has reported on 446 Health Hazards Evaluations that were done in response to indoor air complaints. This data base is the source of most of the published accounts of building-related illness. Their results are summarized here with a discussion of common pollutants (tobacco smoke, formaldehyde, other organic volatiles), and the limitations of the available industrial hygiene and epidemiologic data. There has been one large scale epidemiologic survey of symptoms among office workers. The results associate risk of symptoms to building design and characteristics of the heating/air-conditioning systems, consistent with the NIOSH experience. Building construction since the 1970s has utilized energy conservation measures such as improved insulation, reduced air exchange, and construction without opening windows. These buildings are considered airtight and are commonly involved in episodes of building-associated illness in which no specific etiologic agent can be identified. After increasing the percentage of air exchange or correcting specific deficiencies found in the heating/air-conditioning systems, the health complaints often resolve, hence, the term tight building syndrome or sick building syndrome.

  13. The impact of flood and post-flood cleaning on airborne microbiological and particle contamination in residential houses.

    PubMed

    He, Congrong; Salonen, Heidi; Ling, Xuan; Crilley, Leigh; Jayasundara, Nadeesha; Cheung, Hing Cho; Hargreaves, Megan; Huygens, Flavia; Knibbs, Luke D; Ayoko, Godwin A; Morawska, Lidia

    2014-08-01

    In January 2011, Brisbane, Australia, experienced a major river flooding event. We aimed to investigate its effects on air quality and assess the role of prompt cleaning activities in reducing the airborne exposure risk. A comprehensive, multi-parameter indoor and outdoor measurement campaign was conducted in 41 residential houses, 2 and 6 months after the flood. The median indoor air concentrations of supermicrometer particle number (PN), PM10, fungi and bacteria 2 months after the flood were comparable to those previously measured in Brisbane. These were 2.88 p cm(-3), 15 μg m(-3), 804 cf um(-3) and 177 cf um(-3) for flood-affected houses (AFH), and 2.74 p cm(-3), 15 μg m(-3), 547 cf um(-3) and 167 cf um(-3) for non-affected houses (NFH), respectively. The I/O (indoor/outdoor) ratios of these pollutants were 1.08, 1.38, 0.74 and 1.76 for AFH and 1.03, 1.32, 0.83 and 2.17 for NFH, respectively. The average of total elements (together with transition metals) in indoor dust was 2296 ± 1328 μg m(-2) for AFH and 1454 ± 678 μg m(-2) for NFH, respectively. In general, the differences between AFH and NFH were not statistically significant, implying the absence of a measureable effect on air quality from the flood. We postulate that this was due to the very swift and effective cleaning of the flooded houses by 60,000 volunteers. Among the various cleaning methods, the use of both detergent and bleach was the most efficient at controlling indoor bacteria. All cleaning methods were equally effective for indoor fungi. This study provides quantitative evidence of the significant impact of immediate post-flood cleaning on mitigating the effects of flooding on indoor bioaerosol contamination and other pollutants.

  14. Antioxidant therapy attenuates oxidative stress in the blood of subjects exposed to occupational airborne contamination from coal mining extraction and incineration of hospital residues.

    PubMed

    Wilhelm Filho, D; Avila, S; Possamai, F P; Parisotto, E B; Moratelli, A M; Garlet, T R; Inácio, D B; Torres, M A; Colepicolo, P; Dal-Pizzol, F

    2010-10-01

    Coal mining and incineration of solid residues of health services (SRHS) generate several contaminants that are delivered into the environment, such as heavy metals and dioxins. These xenobiotics can lead to oxidative stress overgeneration in organisms and cause different kinds of pathologies, including cancer. In the present study the concentrations of heavy metals such as lead, copper, iron, manganese and zinc in the urine, as well as several enzymatic and non-enzymatic biomarkers of oxidative stress in the blood (contents of lipoperoxidation = TBARS, protein carbonyls = PC, protein thiols = PT, α-tocopherol = AT, reduced glutathione = GSH, and the activities of glutathione S-transferase = GST, glutathione reductase = GR, glutathione peroxidase = GPx, catalase = CAT and superoxide dismutase = SOD), in the blood of six different groups (n = 20 each) of subjects exposed to airborne contamination related to coal mining as well as incineration of solid residues of health services (SRHS) after vitamin E (800 mg/day) and vitamin C (500 mg/day) supplementation during 6 months, which were compared to the situation before the antioxidant intervention (Ávila et al., Ecotoxicology 18:1150-1157, 2009; Possamai et al., Ecotoxicology 18:1158-1164, 2009). Except for the decreased manganese contents, heavy metal concentrations were elevated in all groups exposed to both sources of airborne contamination when compared to controls. TBARS and PC concentrations, which were elevated before the antioxidant intervention decreased after the antioxidant supplementation. Similarly, the contents of PC, AT and GSH, which were decreased before the antioxidant intervention, reached values near those found in controls, GPx activity was reestablished in underground miners, and SOD, CAT and GST activities were reestablished in all groups. The results showed that the oxidative stress condition detected previously to the antioxidant supplementation in both directly and indirectly subjects

  15. Effect of proximity to a cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens and evaluation of the potential for airborne transmission.

    PubMed

    Berry, Elaine D; Wells, James E; Bono, James L; Woodbury, Bryan L; Kalchayanand, Norasak; Norman, Keri N; Suslow, Trevor V; López-Velasco, Gabriela; Millner, Patricia D

    2015-02-01

    The impact of proximity to a beef cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens was examined. In each of 2 years, leafy greens were planted in nine plots located 60, 120, and 180 m from a cattle feedlot (3 plots at each distance). Leafy greens (270) and feedlot manure samples (100) were collected six different times from June to September in each year. Both E. coli O157:H7 and total E. coli bacteria were recovered from leafy greens at all plot distances. E. coli O157:H7 was recovered from 3.5% of leafy green samples per plot at 60 m, which was higher (P < 0.05) than the 1.8% of positive samples per plot at 180 m, indicating a decrease in contamination as distance from the feedlot was increased. Although E. coli O157:H7 was not recovered from air samples at any distance, total E. coli was recovered from air samples at the feedlot edge and all plot distances, indicating that airborne transport of the pathogen can occur. Results suggest that risk for airborne transport of E. coli O157:H7 from cattle production is increased when cattle pen surfaces are very dry and when this situation is combined with cattle management or cattle behaviors that generate airborne dust. Current leafy green field distance guidelines of 120 m (400 feet) may not be adequate to limit the transmission of E. coli O157:H7 to produce crops planted near concentrated animal feeding operations. Additional research is needed to determine safe set-back distances between cattle feedlots and crop production that will reduce fresh produce contamination.

  16. Effect of Proximity to a Cattle Feedlot on Escherichia coli O157:H7 Contamination of Leafy Greens and Evaluation of the Potential for Airborne Transmission

    PubMed Central

    Wells, James E.; Bono, James L.; Woodbury, Bryan L.; Kalchayanand, Norasak; Norman, Keri N.; Suslow, Trevor V.; López-Velasco, Gabriela; Millner, Patricia D.

    2014-01-01

    The impact of proximity to a beef cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens was examined. In each of 2 years, leafy greens were planted in nine plots located 60, 120, and 180 m from a cattle feedlot (3 plots at each distance). Leafy greens (270) and feedlot manure samples (100) were collected six different times from June to September in each year. Both E. coli O157:H7 and total E. coli bacteria were recovered from leafy greens at all plot distances. E. coli O157:H7 was recovered from 3.5% of leafy green samples per plot at 60 m, which was higher (P < 0.05) than the 1.8% of positive samples per plot at 180 m, indicating a decrease in contamination as distance from the feedlot was increased. Although E. coli O157:H7 was not recovered from air samples at any distance, total E. coli was recovered from air samples at the feedlot edge and all plot distances, indicating that airborne transport of the pathogen can occur. Results suggest that risk for airborne transport of E. coli O157:H7 from cattle production is increased when cattle pen surfaces are very dry and when this situation is combined with cattle management or cattle behaviors that generate airborne dust. Current leafy green field distance guidelines of 120 m (400 feet) may not be adequate to limit the transmission of E. coli O157:H7 to produce crops planted near concentrated animal feeding operations. Additional research is needed to determine safe set-back distances between cattle feedlots and crop production that will reduce fresh produce contamination. PMID:25452286

  17. Direct Analysis of Low-Volatile Molecular Marker Extract from Airborne Particulate Matter Using Sensitivity Correction Method

    PubMed Central

    Irei, Satoshi

    2016-01-01

    Molecular marker analysis of environmental samples often requires time consuming preseparation steps. Here, analysis of low-volatile nonpolar molecular markers (5-6 ring polycyclic aromatic hydrocarbons or PAHs, hopanoids, and n-alkanes) without the preseparation procedure is presented. Analysis of artificial sample extracts was directly conducted by gas chromatography-mass spectrometry (GC-MS). After every sample injection, a standard mixture was also analyzed to make a correction on the variation of instrumental sensitivity caused by the unfavorable matrix contained in the extract. The method was further validated for the PAHs using the NIST standard reference materials (SRMs) and then applied to airborne particulate matter samples. Tests with the SRMs showed that overall our methodology was validated with the uncertainty of ~30%. The measurement results of airborne particulate matter (PM) filter samples showed a strong correlation between the PAHs, implying the contributions from the same emission source. Analysis of size-segregated PM filter samples showed that their size distributions were found to be in the PM smaller than 0.4 μm aerodynamic diameter. The observations were consistent with our expectation of their possible sources. Thus, the method was found to be useful for molecular marker studies. PMID:27127511

  18. Modeling Ellipsometry Measurements of Molecular Thin-Film Contamination on Genesis Array Samples

    NASA Technical Reports Server (NTRS)

    Calaway, Michael J.; Stansbery, E. K.; McNamara, K. M.

    2006-01-01

    The discovery of a molecular thin-film contamination on Genesis flown array samples changed the course of preliminary assessment strategies. Analytical techniques developed to measure solar wind elemental abundances must now compensate for a thin-film contamination. Currently, this is done either by experimental cleaning before analyses or by depth-profiling techniques that bypass the surface contamination. Inside Johnson Space Center s Genesis dedicated ISO Class 4 (Class 10) cleanroom laboratory, the selection of collector array fragments allocated for solar wind analyses are based on the documentation of overall surface quality, visible surface particle contamination greater than 1 m, and the amount of thin film contamination measured by spectroscopic ellipsometry. Documenting the exact thickness, surface topography, and chemical composition of these contaminates is also critical for developing accurate cleaning methods. However, the first step in characterization of the molecular film is to develop accurate ellipsometry models that will determine an accurate thickness measurement of the contamination film.

  19. Temporal and Spatial Patterns of Airborne Contaminants Relative to Amphibian Population in Sequoia and Kings Canyon National Parks, California

    EPA Science Inventory

    Airborne agricultural pesticides are being transported many tens of kilometers to remote locations in mountain areas, and they have been implicated as a cause for recent, dramatic population declines of several amphibian species in such areas. The strongest case is for the mount...

  20. Short path thermal desorption GC/MS for screening of molecular contamination in laser systems

    NASA Astrophysics Data System (ADS)

    Canham, John S.

    2005-02-01

    In high intensity laser systems, molecular contamination represents a risk to the optics. In most situations, molecular contamination is somewhat of a wild card. It is known that it is not required that the contaminant be condensible to initiate damage within a laser system. It is also known that in many cases materials that pass ASTM E-595, are known to precipitate laser optic damage. What has not been known is why. Methods have been developed for the identification, and potential quantitation of trace material emissions that initiate laser optic damage.

  1. Z306 molecular contamination ad hoc committee results

    NASA Technical Reports Server (NTRS)

    Golden, Johnny L.

    1992-01-01

    LDEF external surfaces which did not receive significant amounts of atomic oxygen were observed to be coated with a brown contamination, apparently the result of a condensed organic residue darkened due to UV radiation exposure. During the initial Materials Special Investigation Group (MSIG) Meeting after LDEF deintegration, held in Seattle - July 1990, this organic contamination was the subject of much discussion. The amount of contamination was thought to be significant and its source was immediately believed to be the Z306 black thermal control coating used to coat the entire inner surface of LDEF. Due to the size of the structure, it was not feasible to bake-out the coating. However, initial data on the contamination film was confusing in that significant amounts of silicon was observed by several different researchers. Silicon (from silicone) was not expected to be a potential outgassing product of the Z306 polyurethane coating. To investigate the connection between external contamination and the interior paint, a MSIG ad hoc committee was formed.

  2. Exploring Surface Analysis Techniques for the Detection of Molecular Contaminants on Spacecraft

    NASA Technical Reports Server (NTRS)

    Rutherford, Gugu N.; Seasly, Elaine; Thornblom, Mark; Baughman, James

    2016-01-01

    Molecular contamination is a known area of concern for spacecraft. To mitigate this risk, projects involving space flight hardware set requirements in a contamination control plan that establishes an allocation budget for the exposure of non-volatile residues (NVR) onto critical surfaces. The purpose of this work will focus on non-contact surface analysis and in situ monitoring to mitigate molecular contamination on space flight hardware. By using Scanning Electron Microscopy and Energy Dispersive Spectroscopy (SEM-EDS) with Raman Spectroscopy, an unlikely contaminant was identified on space flight hardware. Using traditional and surface analysis methods provided the broader view of the contamination sources allowing for best fit solutions to prevent any future exposure.

  3. [Molecular Identification and Toxicity of Pufferfish Juveniles Contaminating Whitebait Products].

    PubMed

    Kiriake, Aya; Ohta, Akira; Okayama, Sakurako; Matsuura, Keiichi; Ishizaki, Shoichiro; Nagashima, Yuji

    2016-01-01

    Catches of whitebait, sardine fry, sometimes contains other marine animals, including fishes, mollusks, and crustaceans, and therefore boiled and dried whitebait products may contain these marine animals if sorting is incomplete. In September 2014, contamination of boiled and dried whitebait products with pufferfish juveniles became a serious food safety concern, as tiger pufferfish Takifugu rubripes juveniles are toxic and contain tetrodotoxin (TTX). The toxicity of the juveniles of other pufferfish species, however, is unclear. To evaluate the food safety of whitebait products contaminated with pufferfish juveniles, we identified the species and toxicity of pufferfish juveniles contaminating whitebait products processed between July and September, 2014. Nucleotide sequence analysis of 16S rRNA or cytochrome b gene fragments of the mitochondrial DNA indicated that partial sequences of the polymerase chain reaction products of 15 specimens were identical with those of Lagocephalus spadiceus, and partial sequence from 2 specimens were identical with those of Takifugu vermicularis. We analyzed TTX by liquid chromatography-tandem mass spectrometry. TTX was not detected in the L. spadiceus specimens and was below the quantification limits (30 ng/g) in a T. vermicularis specimen. Based on whitebait product manufacturer's research, 795 individuals and 27.2 g of pufferfish juveniles were detected in 8,245 kg whitebait product. Thus, the ratio of pufferfish to whitebait product was estimated to be 0.096 individual/kg whitebait product and 0.0033 g/kg whitebait product, respectively.

  4. Application of computer-assisted molecular modeling (CAMM) for immunoassay of low molecular weight food contaminants: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Immunoassay for low molecular weight food contaminants, such as pesticides, veterinary drugs, and mycotoxins is now a well-established technique which meets the demands for a rapid, reliable, and cost-effective analytical method. However, due to limited understanding of the fundamental aspects of i...

  5. Field Analysis of Microbial Contamination Using Three Molecular Methods in Parallel

    NASA Technical Reports Server (NTRS)

    Morris, H.; Stimpson, E.; Schenk, A.; Kish, A.; Damon, M.; Monaco, L.; Wainwright, N.; Steele, A.

    2010-01-01

    Advanced technologies with the capability of detecting microbial contamination remain an integral tool for the next stage of space agency proposed exploration missions. To maintain a clean, operational spacecraft environment with minimal potential for forward contamination, such technology is a necessity, particularly, the ability to analyze samples near the point of collection and in real-time both for conducting biological scientific experiments and for performing routine monitoring operations. Multiple molecular methods for detecting microbial contamination are available, but many are either too large or not validated for use on spacecraft. Two methods, the adenosine- triphosphate (ATP) and Limulus Amebocyte Lysate (LAL) assays have been approved by the NASA Planetary Protection Office for the assessment of microbial contamination on spacecraft surfaces. We present the first parallel field analysis of microbial contamination pre- and post-cleaning using these two methods as well as universal primer-based polymerase chain reaction (PCR).

  6. Vacuum Ultraviolet Radiation Desorption of Molecular Contaminants Deposited on Quartz Crystal Microbalances

    NASA Technical Reports Server (NTRS)

    Albyn, Keith; Burns, Dewitt

    2006-01-01

    Recent quartz crystal microbalance measurements made in the Marshall Space Flight Center, Photo-Deposition Facility, for several materials, recorded a significant loss of deposited contaminants when the deposition surface of the microbalance was illuminated by a deuterium lamp. These measurements differ from observations made by other investigators in which the rate of deposition increased significantly when the deposition surface was illuminated with vacuum ultraviolet radiation. These observations suggest that the accelerated deposition of molecular contaminants on optically sensitive surfaces is dependant upon the contaminant being deposited and must be addressed during the materials selection process by common material screening techniques.

  7. Drilling Fluid Contamination during Riser Drilling Quantified by Chemical and Molecular Tracers

    NASA Astrophysics Data System (ADS)

    Inagaki, F.; Lever, M. A.; Morono, Y.; Hoshino, T.

    2012-12-01

    Stringent contamination controls are essential to any type of microbiological investigation, and are particularly challenging in ocean drilling, where samples are retrieved from hundreds of meters below the seafloor. In summer 2012, Integrated Ocean Drilling Expedition 337 aboard the Japanese vessel Chikyu pioneered the use of chemical tracers in riser drilling while exploring the microbial ecosystem of coalbeds 2 km below the seafloor off Shimokita, Japan. Contamination tests involving a perfluorocarbon tracer that had been successfully used during past riserless drilling expeditions were complemented by DNA-based contamination tests. In the latter, likely microbial contaminants were targeted via quantitative polymerase chain reaction assays using newly designed, group-specific primers. Target groups included potential indicators of (a) drilling mud viscosifiers (Xanthomonas, Halomonas), (b) anthropogenic wastewater (Bifidobacterium, Blautia, Methanobrevibacter), and (c) surface seawater (SAR 11, Marine Group I Archaea). These target groups were selected based on past evidence suggesting viscosifiers, wastewater, and seawater as the main sources of microbial contamination in cores retrieved by ocean drilling. Analyses of chemical and molecular tracers are in good agreement, and indicate microorganisms associated with mud viscosifiers as the main contaminants during riser drilling. These same molecular analyses are then extended to subseafloor samples obtained during riserless drilling operations. General strategies to further reduce the risk of microbial contamination during riser and riserless drilling operations are discussed.

  8. Flight Testing of the TWiLiTE Airborne Molecular Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce; McGill, Matthew; Machan, Roman; Reed, Daniel; Cargo, Ryan; Wilkens, David J.; Hart, William; Yorks, John; Scott, Stan; Wake, Shane; Hardesty, Michael; Brewer, Alan

    2010-01-01

    In September, 2009 the TWiLiTE (Tropospheric Wind Lidar Technology Experiment) direct detection Doppler lidar was integrated for engineering flight testing on the NASA ER-2 high altitude aircraft. The TWiI,iTE Doppler lidar measures vertical profiles of wind by transmitting a short ultraviolet (355 nm) laser pulse into the atmosphere, collecting the laser light scattered back to the lidar by air molecules and measuring the Doppler shifted frequency of that light. The magnitude of the Doppler shift is proportional to the wind speed of the air in the parcel scattering the laser light. TWiLiTE was developed with funding from the NASA Earth Science Technology Office (ESTO) Instrument Incubator Program (11P). The primary objectives of the TWiLiTE program are twofold: 1) to advance the development of key technologies and subsystems critical for a future space based Global 3-1) Wind Mission, as recommended by the National Research Council in the recent Decadal Survey for Earth Science [1] and 2) to develop, for the first time, a fully autonomous airborne Doppler lidar and to demonstrate tropospheric wind profile measurements from a high altitude downward looking, moving platform to simulate spaceborne measurements. In this paper we will briefly describe the instrument followed by a discussion of the results from the 2009 engineering test flights

  9. Melting Himalayan glaciers contaminated by legacy atmospheric depositions are important sources of PCBs and high-molecular-weight PAHs for the Ganges floodplain during dry periods.

    PubMed

    Sharma, Brij Mohan; Nizzetto, Luca; Bharat, Girija K; Tayal, Shresth; Melymuk, Lisa; Sáňka, Ondřej; Přibylová, Petra; Audy, Ondřej; Larssen, Thorjørn

    2015-11-01

    Melting glaciers are natural redistributors of legacy airborne pollutants, affecting exposure of pristine proglacial environments. Our data shows that melting Himalayan glaciers can be major contributors of polychlorinated biphenyls (PCBs) and high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) for surface water in the Gangetic Plain during the dry season. Glacial emissions can exceed in some cases inputs from diffuse sources within the catchment. We analyzed air, deposition and river water in several sections along the Ganges River and its major headwaters. The predominant glacial origin of these contaminants in the Himalayan reach was demonstrated using air-water fugacity ratios and mass balance analysis. The proportion of meltwater emissions compared to pollutant discharge at downstream sections in the central part of the Gangetic Plain was between 2 and 200%. By remobilizing legacy pollutants from melting glaciers, climate change can enhance exposure levels over large and already heavily impacted regions of Northern India.

  10. Molecular line contamination in the SCUBA-2 450 and 850 μm continuum data

    NASA Astrophysics Data System (ADS)

    Drabek, E.; Hatchell, J.; Friberg, P.; Richer, J.; Graves, S.; Buckle, J. V.; Nutter, D.; Johnstone, D.; Di Francesco, J.

    2012-10-01

    Observations of the dust emission using millimetre/submillimetre bolometer arrays can be contaminated by molecular line flux, such as flux from 12CO. As the brightest molecular line in the submillimetre, it is important to quantify the contribution of CO flux to the dust continuum bands. Conversion factors were used to convert molecular line integrated intensities to flux detected by bolometer arrays in mJy beam-1. These factors were calculated for 12CO line integrated intensities to the SCUBA-2 850 and 450 μm bands. The conversion factors were then applied to HARP 12CO 3-2 maps of NGC 1333 in the Perseus complex and NGC 2071 and NGC 2024 in the Orion B molecular cloud complex to quantify the respective 12CO flux contribution to the 850 μm dust continuum emission. Sources with high molecular line contamination were analysed in further detail for molecular outflows and heating by nearby stars to determine the cause of the 12CO contribution. The majority of sources had a 12CO 3-2 flux contribution under 20 per cent. However, in regions of molecular outflows, the 12CO can dominate the source dust continuum (up to 79 per cent contamination) with 12CO fluxes reaching ˜68 mJy beam-1.

  11. Documenting the Effectiveness of Cosorption of Airborne Contaminants by a Field-Installed Active Desiccant System: Final Report - Phase 2D

    SciTech Connect

    Fischer, J

    2003-01-23

    The final report for Phase 1 of this research effort (ORNL/SUB/94-SV004/1) concluded that a significant market opportunity would exist for active desiccant systems if it could be demonstrated that they can remove a significant proportion of common airborne contaminants while simultaneously performing the primary function of dehumidifying a stream of outdoor air or recirculated building air. If the engineering community begins to follow the intent of ASHRAE Standard 62, now part of all major building codes, the outdoor air in many major cities may need to be pre-cleaned before it is introduced into occupied spaces. Common air contaminant cosorption capability would provide a solution to three important aspects of the ASHRAE 62-89 standard that have yet to be effectively addressed by heating, ventilation, and air-conditioning (HVAC) equipment manufacturers: (1) The ASHRAE standard defines acceptable outdoor air quality. If the outdoor air contains unacceptable levels of certain common outdoor air contaminants (e.g., sulfur dioxide, ozone), then the standard requires that these contaminants be removed from the outdoor air stream to reach compliance with the acceptable outdoor air quality guidelines. (2) Some engineers prefer to apply a filtration or prescriptive approach rather than a ventilation approach to solving indoor air quality problems. The ASHRAE standard recognizes this approach provided that the filtration technology exists to remove the gaseous contaminants encountered. The performance of current gaseous filtration technologies is not well documented, and they can be costly to maintain because the life of the filter is limited and the cost is high. Moreover, it is not easy to determine when the filters need changing. In such applications, an additional advantage provided by the active desiccant system would be that the same piece of equipment could control space humidity and provide filtration, even during unoccupied periods, if the active desiccant system

  12. Assessment of Personal Airborne Exposures and Surface Contamination from X-ray Vaporization of Beryllium Targets at the National Ignition Facility.

    PubMed

    Paik, Samuel Y; Epperson, Patrick M; Kasper, Kenneth M

    2017-02-28

    This study presents air and surface sampling data collected over the first two years since beryllium was introduced as a target material at the National Ignition Facility. Over this time, 101 experiments with beryllium-containing targets were executed. The data provides an assessment of current conditions in the facility and a baseline for future impacts as new, reduced regulatory limits for beryllium are being proposed by both the Occupational Safety and Health Administration and Department of Energy. This study also investigates how beryllium deposits onto exposed surfaces as a result of x-ray vaporization and the effectiveness of simple decontamination measures in reducing the amount of removable beryllium from a surface. Based on 1,961 surface wipe samples collected from entrant components (equipment directly exposed to target debris) and their surrounding work areas during routine reconfiguration activities, only one result was above the beryllium release limit of 0.2 μg/100 cm(2) and 27 results were above the analytical reporting limit of 0.01 μg/100 cm(2), for a beryllium detection rate of 1.4%. Surface wipe samples collected from the internal walls of the NIF target chamber, however, showed higher levels of beryllium, with beryllium detected on 73% and 87% of the samples during the first and second target chamber entries (performed annually), respectively, with 23% of the samples above the beryllium release limit during the second target chamber entry. The analysis of a target chamber wall panel exposed during the first 30 beryllium-containing experiments (cumulatively) indicated that 87% of the beryllium contamination remains fixed onto the surface after wet wiping the surface and 92% of the non-fixed contamination was removed by decontaminating the surface using a dry wipe followed by a wet wipe. Personal airborne exposures assessed during access to entrant components and during target chamber entry indicated that airborne beryllium was not present

  13. Thermal Catalytic Oxidation of Airborne Contaminants by a Reactor Using Ultra-Short Channel Length, Monolithic Catalyst Substrates

    NASA Technical Reports Server (NTRS)

    Perry, J. L.; Tomes, K. M.; Tatara, J. D.

    2005-01-01

    Contaminated air, whether in a crewed spacecraft cabin or terrestrial work and living spaces, is a pervasive problem affecting human health, performance, and well being. The need for highly effective, economical air quality processes spans a wide range of terrestrial and space flight applications. Typically, air quality control processes rely on absorption-based processes. Most industrial packed-bed adsorption processes use activated carbon. Once saturated, the carbon is either dumped or regenerated. In either case, the dumped carbon and concentrated waste streams constitute a hazardous waste that must be handled safely while minimizing environmental impact. Thermal catalytic oxidation processes designed to address waste handling issues are moving to the forefront of cleaner air quality control and process gas decontamination processes. Careful consideration in designing the catalyst substrate and reactor can lead to more complete contaminant destruction and poisoning resistance. Maintenance improvements leading to reduced waste handling and process downtime can also be realized. Performance of a prototype thermal catalytic reaction based on ultra-short waste channel, monolith catalyst substrate design, under a variety of process flow and contaminant loading conditions, is discussed.

  14. Removing external DNA contamination from arthropod predators destined for molecular gut-content analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Field and laboratory experiments have demonstrated that mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, can lead to contamination of fed pred...

  15. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

    The heating, ventilating, and air conditioning (HVAC) systems in older buildings often do not adequately handle air-borne contaminants. Outlines a three-stage Indoor Air Quality (IAQ) assessment and describes a case in point at a Pittsburgh, Pennsylvania, school. (MLF)

  16. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  17. Long-Term Oil Contamination Alters the Molecular Ecological Networks of Soil Microbial Functional Genes

    PubMed Central

    Liang, Yuting; Zhao, Huihui; Deng, Ye; Zhou, Jizhong; Li, Guanghe; Sun, Bo

    2016-01-01

    With knowledge on microbial composition and diversity, investigation of within-community interactions is a further step to elucidate microbial ecological functions, such as the biodegradation of hazardous contaminants. In this work, microbial functional molecular ecological networks were studied in both contaminated and uncontaminated soils to determine the possible influences of oil contamination on microbial interactions and potential functions. Soil samples were obtained from an oil-exploring site located in South China, and the microbial functional genes were analyzed with GeoChip, a high-throughput functional microarray. By building random networks based on null model, we demonstrated that overall network structures and properties were significantly different between contaminated and uncontaminated soils (P < 0.001). Network connectivity, module numbers, and modularity were all reduced with contamination. Moreover, the topological roles of the genes (module hub and connectors) were altered with oil contamination. Subnetworks of genes involved in alkane and polycyclic aromatic hydrocarbon degradation were also constructed. Negative co-occurrence patterns prevailed among functional genes, thereby indicating probable competition relationships. The potential “keystone” genes, defined as either “hubs” or genes with highest connectivities in the network, were further identified. The network constructed in this study predicted the potential effects of anthropogenic contamination on microbial community co-occurrence interactions. PMID:26870020

  18. The potential of elemental and isotopic analysis of tree bark for discriminating sources of airborne lead contamination in the UK.

    PubMed

    Bellis, D; McLeod, C W; Satake, K

    2001-02-01

    Samples of tree bark, which accumulate airborne material, were collected from seven locations in the UK to provide an indication of the magnitude and source of lead pollution. Measurement of the Pb content and 206/207Pb stable isotope ratio by inductively coupled plasma mass spectrometry revealed significant differences between the sites. The concentration of Pb varied over almost four orders of magnitude from 7.2 to 9,600 micrograms g-1, the maximum values being found near a 'secondary' Pb smelter. The 206/207Pb isotope ratios varied from 1.108 +/- 0.002 to 1.169 +/- 0.001. The lowest Pb concentrations and highest isotope ratios were detected in bark samples from the Scilly Isles, reflecting the low-level of industry and road traffic. In contrast, samples obtained from a city centre (Sheffield) and near a motorway (M1) contained 25-46 micrograms g-1 Pb and recorded the lowest 206/207Pb ratios. Higher concentrations in the vicinity of a coal-fired power station recorded a 206/207Pb ratio of 1.14, suggesting a significant contribution from fly-ash. The relative contribution of lead from petrol (206/207Pb = 1.08) and other sources such as coal (206/207Pb = 1.18) were thus estimated using mass balance equations. Tree bark near the lead smelter recorded an intermediate 206/207Pb ratio of 1.13 reflecting the processing of material of mixed origin.

  19. Allergy arising from exposure to airborne contaminants in an insect rearing facility: Health effects and exposure control

    SciTech Connect

    Wolff, D.

    1994-06-01

    In agricultural crop improvement, yield under various stress conditions and limiting factors is assessed experimentally. Of the stresses on plants which affect yield are those due to insects. Ostrinia nubilalis, the European corn borer (corn borer) is a major pest in sweet and field corn in the U.S. There are many ways to fight crop pests such as the corn borer, including (1) application of chemical insecticides, (2) application of natural predators and, (3) improving crop resistance through plant genetics programs. Randomized field trials are used to determine the effectiveness of pest management programs. These trials frequently consist of randomly selected crop plots to which well-defined input regimes are instituted. For example, corn borers might be released onto crop plots in several densities at various stages of crop development, then sprayed with different levels of pesticide. These experiments are duplicated across regions and, in some cases across the country, to determine, in this instance for example, the best pesticide application rate for a given pest density and crop development stage. In order to release these pests onto crop plots, one must have an adequate supply of the insect pest. In winter months studies are carried out in the laboratory to examine chemical and natural pesticide effectiveness, as well as such things as the role of pheromones in moth behavior. The advantage in field trials is that yield data can be garnered directly. In this country, insects are raised for crop research primarily through the US Department of Agriculture, in cooperation with public Land Grant Universities and, by the private sector agricultural concerns - seed companies and others. This study quantifies the airborne allergen exposure of persons working in a Land Grant University entomology lab were allergy to European corn borer was suspected.

  20. Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning.

    PubMed

    Seidl, M; Da, G; Ausset, P; Haenn, S; Géhin, E; Moulin, L

    2016-04-01

    Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure.

  1. Molecular and stable carbon isotopic characterization of PAH contaminants at McMurdo Station, Antarctica.

    PubMed

    Kim, Moonkoo; Kennicutt, Mahlon C; Qian, Yaorong

    2006-12-01

    The molecular and stable carbon isotopic compositions of contaminant polycyclic aromatic hydrocarbons (PAHs) at McMurdo Station, Antarctica were analyzed in samples collected from land and sub-tidal area. PAHs in the study areas were characterized by high amounts of naphthalene and alkylated naphthalenes from petroleum products introduced by human activities in the area. Principal component analysis (PCA) of PAH composition data identified multiple sources of PAH contamination in the study area. Compositional assignments of origins were confirmed using compound specific stable carbon isotopic analysis.

  2. Molecular-Level Processes Governing the Interaction of Contaminants with Iron and Manganese Oxides - Final Report

    SciTech Connect

    Brown Jr., G. E.; Chambers, S. A.

    1999-10-31

    Many of the inorganic and organic contaminants present in sediments at DOE sites can be altered or destroyed by reduction and oxidation (redox) reactions occurring at mineral surfaces. A fundamental understanding of such redox processes provided by molecular-level studies on structurally and compositionally well-defined mineral surfaces will lead to: (i) improved models of contaminant fate and transport in geochemical systems, and (ii) optimized manipulation of these processes for remediation purposes. To contribute to this understanding, we will study, both experimentally and theoretically, redox processes involving three important contaminants - chromate ion, carbon tetrachloride, and trichloroethene TCE, on the following iron and manganese oxides - hematite, magnetite, maghemite, and pyrolusite. These oxides and their hydroxylated analogs commonly occur as coatings on minerals or as interfaces in the subsurface environment. Single-crystal surfaces of these oxides will be synthesized in carefully controlled fashion by molecular beam epitaxy. These surfaces, as well as high surface are powdered samples of these oxides, will be used in spectroscopic and kinetic experiments in both aqueous and gas phases. Our goal is to identify products and to determine the kinetics and mechanisms of surface-catalyzed redox reaction of Cr(VI) and CR(III), and the reductive dechlorination of carbon tetrachloride and TCE. The combination of theory and experiment will provide the base information needed to scale from the molecular level to the microscopic grain level minerals.

  3. Molecular responses of European flounder (Platichthys flesus) chronically exposed to contaminated estuarine sediments.

    PubMed

    Williams, Tim D; Davies, Ian M; Wu, Huifeng; Diab, Amer M; Webster, Lynda; Viant, Mark R; Chipman, J Kevin; Leaver, Michael J; George, Stephen G; Moffat, Colin F; Robinson, Craig D

    2014-08-01

    Molecular responses to acute toxicant exposure can be effective biomarkers, however responses to chronic exposure are less well characterised. The aim of this study was to determine chronic molecular responses to environmental mixtures in a controlled laboratory setting, free from the additional variability encountered with environmental sampling of wild organisms. Flounder fish were exposed in mesocosms for seven months to a contaminated estuarine sediment made by mixing material from the Forth (high organics) and Tyne (high metals and tributyltin) estuaries (FT) or a reference sediment from the Ythan estuary (Y). Chemical analyses demonstrated that FT sediment contained significantly higher concentrations of key environmental pollutants (including polycyclic aromatic hydrocarbons (PAHs), chlorinated biphenyls and heavy metals) than Y sediment, but that chronically exposed flounder showed a lack of differential accumulation of contaminants, including heavy metals. Biliary 1-hydroxypyrene concentration and erythrocyte DNA damage increased in FT-exposed fish. Transcriptomic and (1)H NMR metabolomic analyses of liver tissues detected small but statistically significant alterations between fish exposed to different sediments. These highlighted perturbance of immune response and apoptotic pathways, but there was a lack of response from traditional biomarker genes. Gene-chemical association annotation enrichment analyses suggested that polycyclic aromatic hydrocarbons were a major class of toxicants affecting the molecular responses of the exposed fish. This demonstrated that molecular responses of sentinel organisms can be detected after chronic mixed toxicant exposure and that these can be informative of key components of the mixture.

  4. MOLECULAR EVALUATION OF CHANGES IN PLANKTONIC BACTERIAL POPULATIONS RESULTING FROM EQUINE FECAL CONTAMINATION IN A SUB-WATERSHED

    EPA Science Inventory

    Considerable emphasis has been placed on developing watershed-based strategies with the potential to reduce non-point-source fecal contamination. Molecular methods applied used 16S-ribosomal-deoxyribonucleic-acid (rDNA) to try to determine sources of fecal contamination. Objectiv...

  5. Molecular conductivity indices for modelling toxicities of Great Lakes contaminants to Daphnia pulex

    USGS Publications Warehouse

    Hickey, James P.; Passino, Dora R.M.; Frank, Anthony M.

    1988-01-01

    Hazard assessment of hundreds of observed and potential contaminants in fish, sediment, and water of the Great Lakes is necessary to determine impact on fishery sources and other aquatic biota. The hundreds of new compunds introduced each year have few measured properties. Mathematical models based on quantitative structure-activity relationships (QSARs) provide rapid, inexpensive estimates of physical properties and toxicites. These models are useful when the contaminants are not commercially available for testing. To develop these predicitive models, acute bioassay results (48-hr EC50 of Daphnia pulex) of 62 compounds were regressed against several modes of molecular connectivity indices. The compunds were selected from the more hazardous classes in a list of 476 compunds tentatively identified by GC/MS in Great Lakes fish.

  6. The Effect of Molecular Contamination on the Emissivity Spectral Index in Orion A

    NASA Astrophysics Data System (ADS)

    Coudé, Simon; Bastien, Pierre; Drabek, Emily; Johnstone, Doug; Hatchell, Jennifer

    2013-07-01

    The emissivity spectral index is a critical component in the study of the physical properties of dust grains in cold and optically thin interstellar star forming regions. Since submillimeter astronomy is an ideal tool to measure the thermal emission of those dust grains, it can be used to characterize this important parameter. We present the SCUBA-2 shared risks observations at 450 μm and 850 μm of the Orion A molecular cloud obtained at the James-Clerk-Maxwell telescope. Previous studies showed that molecular emission lines can also contribute significantly to the measured fluxes in those continuum bands. We use HARP 12CO 3-2 maps to evaluate the total molecular line contamination in the SCUBA-2 maps and its effect on the determination of the spectral index in highly contaminated areas. With the corrected fluxes, we have obtained new spectral index maps for different regions of the well-known integral-shaped filament. This work is part of an ongoing effort to characterize the properties of star forming regions in the Gould belt with the new instruments available at the JCMT.

  7. The Atmospheric Distribution of Molecular Hydrogen (H2) and Related Species During HIPPO and Other Recent Airborne Missions

    NASA Astrophysics Data System (ADS)

    Hintsa, E. J.; Moore, F. L.; Dutton, G. S.; Hall, B. D.; Nance, J. D.; Hurst, D. F.; Novelli, P. C.; Elkins, J. W.; Daube, B.; Kort, E. A.; Pittman, J. V.; Santoni, G. W.; Wofsy, S. C.; Jaegle, L.

    2012-12-01

    The goal of the HIAPER Pole-to-Pole Observations (HIPPO) of Carbon Cycle and Greenhouse Gases Study was to measure a large set of trace gases and aerosols as a function of altitude and latitude in different seasons in order to better understand their sources, sinks, and atmospheric transport, and to use these measurements to compare with a variety of chemical transport models, ultimately leading to improvements in the models. The NSF/NCAR Gulfstream V (GV) aircraft (formerly known as HIAPER) was equipped with instruments for trace gases, aerosols, and meteorological parameters, and flew a set of five transects in 2009-2011 from Colorado, to Anchorage, AK, to near the North Pole, then south to Christchurch, NZ, toward the edge of Antarctica, and back to the northern hemisphere high latitudes, with intermediate stops at different locations in the Pacific Ocean. On each leg of the journey, the GV carried out a series of profiles from the marine (or continental) boundary layer to the stratosphere, generating a set of altitude/latitude slices of the atmosphere in different seasons (January 2009, October-November 2009, March-April 2010, June-July 2011, and August-September 2011). While HIPPO was in progress, data were also obtained at higher altitudes in the stratosphere over the Pacific Ocean from the NASA Global Hawk aircraft during the GloPac (Global Hawk Pacific; March-April 2010) and ATTREX (Airborne Tropical Tropopause Experiment; October-November 2011) missions, respectively. In this presentation, results are shown that were obtained from the UCATS and PANTHER instruments and other sensors on board the GV and the Global Hawk. UCATS (the UAS Chromatograph for Atmospheric Trace Species) flew on both platforms and was configured to measure N2O, SF6, H2, CH4, CO, water vapor, and ozone. PANTHER (PAN and other Trace Hydrohalocarbon ExpeRiment) measures an even larger set of trace gases with gas chromatography and a mass spectrometer, and flew on every leg of HIPPO. The

  8. Molecular Contamination on Anodized Aluminum Components of the Genesis Science Canister

    NASA Technical Reports Server (NTRS)

    Burnett, D. S.; McNamara, K. M.; Jurewicz, A.; Woolum, D.

    2005-01-01

    Inspection of the interior of the Genesis science canister after recovery in Utah, and subsequently at JSC, revealed a darkening on the aluminum canister shield and other canister components. There has been no such observation of film contamination on the collector surfaces, and preliminary spectroscopic ellipsometry measurements support the theory that the films observed on the anodized aluminum components do not appear on the collectors to any significant extent. The Genesis Science Team has made an effort to characterize the thickness and composition of the brown stain and to determine if it is associated with molecular outgassing.Detailed examination of the surfaces within the Genesis science canister reveals that the brown contamination is observed to varying degrees, but only on surfaces exposed in space to the Sun and solar wind hydrogen. In addition, the materials affected are primarily composed of anodized aluminum. A sharp line separating the sun and shaded portion of the thermal closeout panel is shown. This piece was removed from a location near the gold foil collector within the canister. Future plans include a reassembly of the canister components to look for large-scale patterns of contamination within the canister to aid in revealing the root cause.

  9. Contamination and UV lasers: lessons learned

    NASA Astrophysics Data System (ADS)

    Daly, John G.

    2015-09-01

    Laser induced damage to optical elements has been a subject of significant research, development, and improvement, since the first lasers were built over the last 50 years. Better materials, with less absorption, impurities, and defects are available, as well as surface coatings with higher laser damage resistance. However, the presence of contamination (particles, surface deposition films, or airborne) can reduce the threshold for damage by several orders of magnitude. A brief review of the anticipated laser energy levels for damage free operation is presented as a lead into the problems associated with contamination for ultraviolet (UV) laser systems. As UV lasers become more common in applications especially in areas such as lithography, these problems have limited reliability and added to costs. This has been characterized as Airborne Molecular Contamination (AMC) in many published reports. Normal engineering guidelines such as screening materials within the optical compartment for low outgassing levels is the first step. The use of the NASA outgassing database (or similar test methods) with low Total Mass Loss (TML) and Condensed Collected Volatiles Collected Mass (CVCM) is a good baseline. Energetic UV photons are capable of chemical bond scission and interaction with surface contaminant or airborne materials results in deposition of obscuring film laser footprints that continue to degrade laser system performance. Laser systems with average powers less than 5 mW have been shown to exhibit aggressive degradation. Lessons learned over the past 15 years with UV laser contamination and steps to reduce risk will be presented.

  10. Understanding molecular mechanisms for improving phytoremediation of heavy metal-contaminated soils.

    PubMed

    Hong-Bo, Shao; Li-Ye, Chu; Cheng-Jiang, Ruan; Hua, Li; Dong-Gang, Guo; Wei-Xiang, Li

    2010-03-01

    Heavy metal pollution of soil is a significant environmental problem with a negative potential impact on human health and agriculture. Rhizosphere, as an important interface of soil and plants, plays a significant role in phytoremediation of contaminated soil by heavy metals, in which, microbial populations are known to affect heavy metal mobility and availability to the plant through release of chelating agents, acidification, phosphate solubilization and redox changes, and therefore, have potential to enhance phytoremediation processes. Phytoremediation strategies with appropriate heavy metal-adapted rhizobacteria or mycorrhizas have received more and more attention. In addition, some plants possess a range of potential mechanisms that may be involved in the detoxification of heavy metals, and they manage to survive under metal stresses. High tolerance to heavy metal toxicity could rely either on reduced uptake or increased plant internal sequestration, which is manifested by an interaction between a genotype and its environment.A coordinated network of molecular processes provides plants with multiple metal-detoxifying mechanisms and repair capabilities. The growing application of molecular genetic technologies has led to an increased understanding of mechanisms of heavy metal tolerance/accumulation in plants and, subsequently, many transgenic plants with increased heavy metal resistance, as well as increased uptake of heavy metals, have been developed for the purpose of phytoremediation. This article reviews advantages, possible mechanisms, current status and future direction of phytoremediation for heavy-metal-contaminated soils.

  11. Identification of molecular markers to follow up the bioremediation of sites contaminated with chlorinated compounds.

    PubMed

    Marzorati, Massimo; Balloi, Annalisa; De Ferra, Francesca; Daffonchio, Daniele

    2010-01-01

    The use of microorganisms to clean up xenobiotics from polluted ecosystems (soil and water) represents an ecosustainable and powerful alternative to traditional remediation processes. Recent developments in molecular-biology-based techniques have led to rapid and sensitive strategies for monitoring and identifying bacteria and catabolic genes involved in the degradation of xenobiotics. This chapter provides a description of recently developed molecular-biology-based techniques, such as PCR with degenerate primers set, real-time quantitative PCR (qPCR), reverse transcription PCR (RT-PCR), southern blot hybridization, and long-range PCR, used to give a picture of the catabolically relevant microorganisms and of the functional genes present in a polluted system. By using a case study of a groundwater aquifer contaminated with 1,2-dichloroethane (1,2-DCA), we describe the identification of microorganisms potentially involved in the 1,2-DCA dehalorespiration (Dehalobacter sp. and Desulfitobacterium sp.) and a complete new gene cluster encoding for a 1,2-DCA reductive dehalogenase. The application of these techniques to bioremediation can improve our understanding of the inner mechanisms to evaluate the feasibility of a given treatment and provide us with a method to follow up bacteria and catabolic genes involved in the degradation of contaminants during the activities in situ.

  12. Risk for molecular contamination of tissue samples evaluated for targeted anti-cancer therapy

    PubMed Central

    Simon, Einav; Fahoum, Ibrahim; Sabo, Edmond; Ben-Izhak, Ofer; Hershkovitz, Dov

    2017-01-01

    With the increasing usage of sensitive PCR technology for pharmacogenetics, cross contamination becomes a significant concern. Researchers employed techniques which basically include replacing laboratory equipment after each sample preparation; however, there are no recommended guidelines. In the present work we wanted to evaluate the risk of cross contamination during tissue processing using the routine precaution measures. Twenty-one surgical samples of lung adenocarcinoma were used, of which 7 contained EGFR exon 19 mutation, 7 contained EGFR exon 21 mutation (p.L858R) and 7 were EGFR wild-type. The samples were ordered by alternating the mutation group to maximize the potential for cross contamination and underwent tissue sectioning and de-paraffinization. The entire process was performed using the same tools. Following DNA extraction all samples underwent PCR amplification and were scrutinized for small fractions of EGFR mutation using deep sequencing with the Ion torrent PGM technology. Twenty samples yielded results. The fraction of mutated copies was 41 ± 23% (range 11–66) for the cases with known exon 19 mutation and 48±24% (range 0–65) for the cases with known exon 21 mutations. No in-frame exon 19 deletion mutations were identified in the wild-type (WT) and exon 21 groups. The fraction of EGFR exon 21 (codon 858) mutations was 0.018±0.014% (range 0–0.05%) in the WT and exon 19 groups, which was not statistically different than the background sequencing artifact noise for the same base-pair alteration (p = 0.21). Our results suggest that standard precautions are sufficient for molecular pathology diagnosis of surgical samples and are not associated with increased risk of cross contamination. PMID:28288198

  13. Molecular Shocks Associated with Massive Young Stars: CO Line Images with a New Far-Infrared Spectroscopic Camera on the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Watson, Dan M.

    1997-01-01

    Under the terms of our contract with NASA Ames Research Center, the University of Rochester (UR) offers the following final technical report on grant NAG 2-958, Molecular shocks associated with massive young stars: CO line images with a new far-infrared spectroscopic camera, given for implementation of the UR Far-Infrared Spectroscopic Camera (FISC) on the Kuiper Airborne Observatory (KAO), and use of this camera for observations of star-formation regions 1. Two KAO flights in FY 1995, the final year of KAO operations, were awarded to this program, conditional upon a technical readiness confirmation which was given in January 1995. The funding period covered in this report is 1 October 1994 - 30 September 1996. The project was supported with $30,000, and no funds remained at the conclusion of the project.

  14. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The focus of the workshop was on how the airborne community can assist in achieving the goals of the Global Change Research Program. The many activities that employ airborne platforms and sensors were discussed: platforms and instrument development; airborne oceanography; lidar research; SAR measurements; Doppler radar; laser measurements; cloud physics; airborne experiments; airborne microwave measurements; and airborne data collection.

  15. Culture and molecular identification of fungal contaminants in edible bird nests.

    PubMed

    Chen, Jennifer Xiao Jing; Wong, Shew Fung; Lim, Patricia Kim Chooi; Mak, Joon Wah

    2015-01-01

    Widespread food poisoning due to microbial contamination has been a major concern for the food industry, consumers and governing authorities. This study is designed to determine the levels of fungal contamination in edible bird nests (EBNs) using culture and molecular techniques. Raw EBNs were collected from five house farms, and commercial EBNs were purchased from five Chinese traditional medicine shops (companies A-E) in Peninsular Malaysia. The fungal contents in the raw and commercial EBNs, and boiled and unboiled EBNs were determined. Culturable fungi were isolated and identified. In this study, the use of these methods revealed that all EBNs had fungal colony-forming units (CFUs) that exceeded the limit set by Standards and Industrial Research Institute of Malaysia (SIRIM) for yeast and moulds in EBNs. There was a significant difference (p < 0.05) in the number of types of fungi isolated from raw and commercial EBNs, but no significant difference in the reduction of the number of types of fungi after boiling the EBNs (p > 0.05). The types of fungi isolated from the unboiled raw EBNs were mainly soil, plant and environmental fungi, while the types of fungi isolated from the boiled raw EBNs, unboiled and boiled commercial EBNs were mainly environmental fungi. Aspergillus sp., Candida sp., Cladosporium sp., Neurospora sp. and Penicillum sp. were the most common fungi isolated from the unboiled and boiled raw and commercial EBNs. Some of these fungi are mycotoxin producers and cause opportunistic infections in humans. Further studies to determine the mycotoxin levels and methods to prevent or remove these contaminations from EBNs for safe consumption are necessary. The establishment and implementation of stringent regulations for the standards of EBNs should be regularly updated and monitored to improve the quality of the EBNs and consumer safety.

  16. Biochemical and Molecular Characterization of Obesumbacterium proteus, a Common Contaminant of Brewing Yeasts

    PubMed Central

    Prest, Andrew G.; Hammond, John R. M.; Stewart, Gordon S. A. B.

    1994-01-01

    We have evaluated the effectiveness of API 20E, Biolog testing, plasmid profiling, ribotyping, and enteric repetitive intergenic consensus (ERIC)-PCR to characterize, classify, and differentiate nine bacterial isolates of the common brewery contaminant Obesumbacterium proteus. Of the five typing techniques, Biolog testing, plasmid profiling, and ERIC-PCR provided the most differentiation, and API 20E testing and ribotyping were relatively indiscriminate. The molecular biology approach of ERIC-PCR offered the ideal combination of speed, simplicity, and discrimination in this study. Overall, the results are supportive of the view that O. proteus can be subdivided into two biogroups, biogroup 1, which has considerable biochemical and genetic homology to Hafnia alvei, and biogroup 2, which is relatively heterogeneous. Images PMID:16349260

  17. Molecular Characterization of Microbial Communities in a JP-5 Fuel Contaminated Soil

    SciTech Connect

    Barcelona, M.J.; Chang, Y.-J.; Gan, Y.D.; Macnaughton, S.J.; Peacock, A.; Stephen, J.R.; White, D.C.

    1999-04-19

    In this study, lipid biomarker characterization of the bacterial and eukaryotic communities was combined with PCR-DGGE analysis of the eubacterial community to evaluate correlation between JP-4 fuel concentration and community structure shifts. Vadose, capillary fringe and saturated-soils were taken from cores within, up- and down-gradient of the contaminant plume. Significant differences in biomass and proportion of Gram negative bacteria were found inside and outside the plume. Sequence analysis of DGGE bands from within the spill site suggested dominance by a limited number of phylogenetically diverse bacteria. Used in tandem with pollutant quantification, these molecular techniques should facilitate significant improvements over current assessment procedures for determination of remediation end points.

  18. Airborne Particles.

    ERIC Educational Resources Information Center

    Ojala, Carl F.; Ojala, Eric J.

    1987-01-01

    Describes an activity in which students collect airborne particles using a common vacuum cleaner. Suggests ways for the students to convert their data into information related to air pollution and human health. Urges consideration of weather patterns when analyzing the results of the investigation. (TW)

  19. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

    ATM (Airborne Thematic Mapper) was developed for NSTL (National Space Technology Companies) by Daedalus Company. It offers expanded capabilities for timely, accurate and cost effective identification of areas with prospecting potential. A related system is TIMS, Thermal Infrared Multispectral Scanner. Originating from Landsat 4, it is also used for agricultural studies, etc.

  20. Using a temperature-controlled quartz crystal microbalance in a space equipment cleanroom to monitor molecular contamination

    NASA Technical Reports Server (NTRS)

    Mitchell, William J.

    1994-01-01

    There is a need for continuous monitoring for molecular contamination in clean rooms where spaceflight equipment is assembled, integrated, and tested to insure that contamination budgets are met. The TQCM (temperature-controlled quartz crystal microbalance) can be used to provide both a real time warning and a cumulative measurement of molecular contamination. It has advantages over the other measurement methods such as witness mirrors, NVR (non-volatile residue) plates, and gas analyzers. A comparison of the TQCM sensitivity and ease of operations is made with the other methods. The surface acoustic wave microbalance (SAW), a newly developed instrument similar to TQCM, is considered in the comparison. An example is provided of TQCM use at Goddard Space Flight Center when the Wide Field Planetary Camera 2(WFPC-2) and the Corrective Optics Space Telescope Axial Replacement (COSTAR) were undergoing integrated testing prior to their installation in the Hubble Space Telescope on its first servicing mission. Areas for further investigation are presented.

  1. The JCMT Gould Belt Survey: the effect of molecular contamination in SCUBA-2 observations of Orion A

    NASA Astrophysics Data System (ADS)

    Coudé, S.; Bastien, P.; Kirk, H.; Johnstone, D.; Drabek-Maunder, E.; Graves, S.; Hatchell, J.; Chapin, E. L.; Gibb, A. G.; Matthews, B.; JCMT Gould Belt Survey Team

    2016-04-01

    Thermal emission from cold dust grains in giant molecular clouds can be used to probe the physical properties, such as density, temperature and emissivity in star-forming regions. We present the Submillimetre Common-User Bolometer Array (SCUBA-2) shared-risk observations at 450 and 850 μm of the Orion A molecular cloud complex taken at the James Clerk Maxwell Telescope (JCMT). Previous studies showed that molecular emission lines can contribute significantly to the measured fluxes in those continuum bands. We use the Heterodyne Array Receiver Programme 12CO J = 3-2 integrated intensity map for Orion A in order to evaluate the molecular line contamination and its effects on the SCUBA-2 maps. With the corrected fluxes, we have obtained a new spectral index α map for the thermal emission of dust in the well-known integral-shaped filament. Furthermore, we compare a sample of 33 sources, selected over the Orion A molecular cloud complex for their high 12CO J = 3-2 line contamination, to 27 previously identified clumps in OMC 4. This allows us to quantify the effect of line contamination on the ratio of 850-450 μm flux densities and how it modifies the deduced spectral index of emissivity β for the dust grains. We also show that at least one Spitzer-identified protostellar core in OMC 5 has a 12CO J = 3-2 contamination level of 16 per cent. Furthermore, we find the strongest contamination level (44 per cent) towards a young star with disc near OMC 2. This work is part of the JCMT Gould Belt Legacy Survey.

  2. Bacterial diversity in a contaminated Alpine glacier as determined by culture-based and molecular approaches.

    PubMed

    Cappa, Fabrizio; Suciu, Nicoleta; Trevisan, Marco; Ferrari, Susanna; Puglisi, Edoardo; Cocconcelli, Pier Sandro

    2014-11-01

    Glaciers are important ecosystems, hosting bacterial communities that are adapted to cold conditions and scarcity of available nutrients. Several works focused on the composition of bacterial communities in glaciers and on the long-range atmospheric deposition of pollutants in glaciers, but it is not clear yet if ski resorts can represent a source of point pollution in near-by glaciers, and if these pollutants can influence the residing bacterial communities. To test these hypotheses, 12 samples were analyzed in Madaccio Glacier, in a 3200 ma.s.l. from two areas, one undisturbed and one close to a summer ski resort that is active since the 1930s. Chemical analyses found concentrations up to 43 ng L(-1) for PCBs and up to 168 μg L(-1) for PAHs in the contaminated area: these values are significantly higher than the ones found in undisturbed glaciers because of long-range atmospheric deposition events, and can be explained as being related to the near-by ski resort activities. Isolation of strains on rich medium plates and PCR-DGGE analyses followed by sequencing of bands allowed the identification of a bacterial community with phylogenetic patterns close to other glacier environments, with Proteobacteria and Actinobacteria the mostly abundant phyla, with Acidobacteria, Firmicutes and Cyanobacteria also represented in the culture-independent analyses. A number of isolates were identified by molecular and biochemical methods as phylogenetic related to known xenobiotic-degrading strains: glaciers subjected to chemical contamination can be important reservoirs of bacterial strains with potential applications in bioremediation.

  3. Molecular diagnostics and chemical analysis for assessing biodegradation of polychlorinated biphenyls in contaminated soils.

    PubMed

    Layton, A C; Lajoie, C A; Easter, J P; Jernigan, R; Sanseverino, J; Sayler, G S

    1994-11-01

    The microbial populations in PCB-contaminated electric power substation capacitor bank soil (TVA soil) and from another PCB-contaminated site (New England soil) were compared to determine their potential to degrade PCB. Known biphenyl operon genes were used as gene probes in colony hybridizations and in dot blots of DNA extracted from the soil to monitor the presence of PCB-degrading organisms in the soils. The microbial populations in the two soils differed in that the population in New England soil was enriched by the addition of 1000 p.p.m. 2-chlorobiphenyl (2-CB) whereas the population in the TVA capacitor bank soil was not affected. PCB degradative activity in the New England soil was indicated by a 50% PCB disappearance (gas chromatography), accumulation of chlorobenzoates (HPLC), and 14CO2 evolution from 14C-2CB. The PCB-degrading bacteria in the New England soil could be identified by their positive hybridization to the bph gene probes, their ability to produce the yellow meta-cleavage product from 2,3-dihydroxybiphenyl (2,3-DHB), and the degradation of specific PCB congeners by individual isolates in resting cell assays. Although the TVA capacitor bank soil lacked effective PCB-degrading populations, addition of a PCB-degrading organism and 10,000 p.p.m. biphenyl resulted in a > 50% reduction of PCB levels. Molecular characterization of soil microbial populations in laboratory scale treatments is expected to be valuable in the design of process monitoring and performance verification approaches for full scale bioremediation.

  4. Effect of proximity to a cattle feedlot on Escherichia coli O157:H7 contamination of leafy greens and evaluation of the potential for airborne transmission

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The impact of proximity to a beef cattle feedlot on E. coli O157:H7 contamination of leafy greens was examined. In each of two years, leafy greens were planted to nine plots located 60, 120, and 180 meters from a cattle feedlot (3 plots each distance). Leafy greens, feedlot manure, and bioaerosol ...

  5. Evaluation of the ultraviolet/ozone technique for on-orbit removal of photolyzed molecular contamination from optical surfaces

    NASA Astrophysics Data System (ADS)

    Frink, Mark E.; Folkman, Mark A.; Darnton, Lane A.

    1992-12-01

    Molecular species outgassed from spacecraft materials adhere tenaciously to and darken spacecraft surfaces when exposed to solar ultraviolet (UV) radiation. Such deposits severely degrade the performance of optical systems operating at UV and visible wavelengths. Data is presented which demonstrates the feasibility of a UV/Ozone cleaning technique in removing such deposits in a space-compatible configuration without damage to the optical surface. The technique involves the UV irradiation of the optical surface in the presence of low pressure molecular oxygen, resulting in the photolytic formation of ozone (O3) and subsequent photochemical removal of the contamination.

  6. Experience with airborne detection of radioactive pollution (ENMOS, IRIS).

    PubMed

    Pavlik, Bohuslav; Engelsmann, Jan

    2004-01-01

    This paper discusses the advantages of airborne monitoring of radioactive pollution and shows example maps indicating manmade pollution from different sources. The sensitivity of airborne radioactive detection is discussed. Comparisons of airborne and different ground measurements are presented. New instrumentation for airborne or ground moving vehicles is briefly described. Airborne footprinting provides rapid, well-defined spatial images of natural and manmade radioactive contamination. Data acquisition integrated with GPS navigation provides consistent data and guarantees proper data location. Real-time airborne measurements are re-calculated, with the use of special algorithms, into absolute units for individual radioactive nuclei contamination of the ground together with dose calculation. Raw records and calculated data are provided after enhanced post-flight processing. Dose rates and detection of different radioactive elements are presented. (ENMOS is a product of Picodas Group Inc. and IRIS is the product of Pico Envirotec Inc.)

  7. UV photofixation of molecular contamination: simulation of in-flight data

    NASA Astrophysics Data System (ADS)

    Vanhove, Emilie; Roussel, Jean-François; Inguimbert, Virginie; Chardon, Jean-Pierre

    2016-09-01

    Growing evidence was accumulated on the deleterious effects of the photofixation of contaminants on solar arrays power and on the optical properties of coatings. UV irradiation indeed promotes contamination accretion, even on surfaces on which condensation would not occur and strongly degrades the optical properties of contamination layers. Recent research conducted at ONERA enabled to implement a photofixation model in the numerical tool COMOVA. Present work aims at assessing the ability of this model to reproduce in-orbit cases and at estimating the sensitivity of the results to input parameters. Simulation results are reasonably close to the in-orbit degradations.

  8. Decontamination of airborne bacteria in meat processing plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of reactive oxygen species (ROS) generating AirOcare equipment on the reduction of airborne bacteria in a meat processing environment was determined. Bacterial strains found in ground beef were used to artificially contaminate the air using a 6-jet Collison nebulizer. Airborne bact...

  9. Molecular-level processes governing the interaction of contaminants with iron and manganese oxides. 1997 annual progress report

    SciTech Connect

    Chambers, S.A.; Brown, G.

    1997-06-01

    'The central tenet of this proposal is that a fundamental understanding of specific mineral surface-site reactivities will substantially improve reactive transport models of contaminants in geologic systems, and will allow more effective remediation schemes to be devised. Most large-scale, macroscopic models employ global chemical reaction kinetics and thermochemistry. However, such models do not incorporate molecular-level input critical to the detailed prediction of how contaminants interact with minerals in the subsurface. A first step leading to the incorporation of molecular-level processes in large-scale macroscopic models is the ability to understand which molecular-level processes will dominate the chemistry at the microscopic grain level of minerals. To this end, the research focuses on the fundamental mechanisms of redox chemistry at mineral surfaces. As much of this chemistry in sediments involves the Fe(III)/Fe(II) and Mn(IV)/Mn(II) couples, the authors focus on mineral phases containing these species. Of particular interest is the effect of the local coordination environment of Fe and Mn atoms on their reactivity toward contaminant species. Studies of the impact of local atomic structure on reactivity in combination with knowledge about the types and amounts of various surfaces on natural grain- size minerals provide the data for statistical models. These models in turn form the basis of the larger-scale macroscopic descriptions of reactivity that are needed for reactive transport models. A molecular-level understanding of these mechanisms will enhance the ability to design much greater performance efficiency, cost effectiveness, and remediation strategies that have minimal negative impact on the local environment. For instance, a comprehensive understanding of how minerals that contain Fe(II) reduce oxyanions and chlorinated organics should enable the design of other Fe(II)-containing remediation materials in a way that is synergistic with existing

  10. Molecular tools to understand the bioremediation effect of plants and earthworms on contaminated marine sediments.

    PubMed

    Moreno, Beatriz; Cañizares, Rosa; Macci, Cristina; Doni, Serena; Masciandaro, Grazia; Benitez, Emilio

    2015-12-30

    A meso-scale pilot plant was set up to test the efficiency of a bioremediation scheme applied to marine sediments contaminated by heavy metals and hydrocarbons. The experiment was implemented for three years in two stages using two remediation agents: plants (Paspalum vaginatum and Tamarix gallica) and earthworms (Eisenia fetida). DNA and RNA-based methodologies were applied to elucidate the dynamics of the bacterial population and were related to improving biological and chemical conditions of the sediments. Bioremediation strategies were successful in removing pollutants from the contaminated sediments and specialization within the bacterial community related to the type of contamination present was detected in the different stages of the process. The highest response of Gram-positive PAH-degraders to the contamination was detected at the beginning and after the first stage of the experiment, corresponding to the uppermost values of degradation.

  11. Results from a 'small box' realtime molecular contamination monitor on STS-3

    NASA Technical Reports Server (NTRS)

    Triolo, J.; Kruger, R.; Mcintosh, R.; Maag, C.

    1983-01-01

    On the basis of early estimates of the Shuttle induced environment, Scialdone (1979) concluded that in the vicinity of the cargo, the cargo would have the largest influence on the environment. As a contamination control device, realtime monitors can indicate safe operational periods for sensitive attached payloads. It was, therefore, decided to develop the OSS-1/Contamination Monitor Package (CMP) experiment which was seen as a forerunner of an operational monitor. A description of the CMP is provided, taking into account four actively temperature controlled quartz crystal microbalances (TQCM). The TQCM temperatures could be varied from -60 C to +80 C. The sensor consisted of a matched pair of quartz crystals. The crystals were designated as a sensor and reference crystal. Results obtained during the STS-3 mission are discussed. These results show the feasibility and advantages of a small real-time contamination monitor.

  12. Elimination and molecular identification of endophytic bacterial contaminants during in vitro propagation of Bambusa balcooa.

    PubMed

    Ray, Syandan Sinha; Ali, Md Nasim; Mukherjee, Shibasis; Chatterjee, Gautam; Banerjee, Maitreyi

    2017-02-01

    Bambusa balcooa is an economically important, multipurpose bamboo species, decidedly used in construction industry. Availability of natural bamboo is depleting very rapidly due to accelerated deforestation and its unrestrained use. The large number and timely supply of saplings are the need of the hour for the restoration of bamboo stands. Micropropagation, being the potent alternative for season independent rapid regeneration, is restricted in bamboo because of endophytic contamination. An in vitro attempt has been taken to overcome the endophytic contamination by using broad spectrum antibiotics as surface sterilant as well as a media component. Ampicillin sodium salt (5 mg/ml for 30 min) as a surface sterilant was found as the best treatment for high bud breaking (80%) coupled with high branching and low contamination (20%) but it was found ineffective to control the contamination during multiplication stage. Then, two endophytes were isolated and minimum inhibitory concentration was determined through antibiotic susceptibility test for successful eradication at multiplication stage. Finally, contamination free cultures were obtained when streptocycline (100 μg/ml) and gentamicin sulphate (75 μg/ml) were added into the medium. The two isolated endophytes, BB1 and BB2, were identified through 16S rDNA techniques and NCBI-BLAST algorithm with 99% sequence similarity with those of Janibacter sp. (KX423734) and Serratia marcescens strain (KX423735). To our knowledge, this is the first report for B. balcooa where antibiotics were used as surface sterilant as well as medium component, to control endophytic bacterial contaminants, followed by their identification.

  13. Nosocomial infections from contaminated endoscopes: a flawed automated endoscope washer. An investigation using molecular epidemiology.

    PubMed

    Alvarado, C J; Stolz, S M; Maki, D G

    1991-09-16

    Approximately 1 year after purchase of one manufacturer's automated endoscope washing machine, we began to detect heavy contamination of upper gastrointestinal (UGI) endoscopes cultured after cleaning and disinfection in the washer. During the first 6 months of 1988, 77% of surveillance cultures (20-mL flush through the biopsy channel) were positive for gram-negative bacilli (median concentration, 10(5) cfu/mL), most frequently Pseudomonas aeruginosa serotype 10. During the first 19 months of use of the washer, nosocomial post-UGI endoscopy colonization or infections with P. aeruginosa increased 36%. Investigations show that endoscope contamination derives from a flaw in the design of the EW-10 washer: the detergent holding tank, inlet water hose, and air vents cannot be reliably disinfected and contain heavy biofilms that recontaminate the machine after it has been disinfected, as specified by the manufacturer, with glutaraldehyde. Only by rinsing machine-cleansed endoscopes with 70% alcohol followed by forced air drying has reliable disinfection been achieved. Since adaptation of terminal alcohol treatment and drying, post-UGI endoscopy colonization or infection by P. aeruginosa has declined threefold (p less than 0.001). Testing in other centers using the manufacturer's EW-10 or EW-20 washer has shown similar contamination. In three centers, including our own, postendoscopy infections by machine-associated type 10 P. aeruginosa have been confirmed by demonstrating concordance between isolates from contaminated machines or endoscopes and from infected patients by immunoblot of whole cell lysates and by pulsed-field electrophoresis of DraI endonuclease-digested genomic DNA. This problem reaffirms the vulnerability to microbial contamination of water-containing apparatus and equipment in patient care and points up the critical importance of engineering design to prevent contamination.

  14. [Applications of molecular biology techniques for the control of aflatoxin contamination].

    PubMed

    Sanchis, V

    1993-02-01

    Aflatoxins are mycotoxins produced by species of Aspergillus flavus group. These toxins have received increased attention from the food industry and the general public because they shown a high toxicity against humans and animal. Different methods are applying to control the aflatoxin contamination. But these conventional methods do not seem to resolve the problem. So, new methods using techniques in biotechnology are now being developed: a) Inhibit the biosynthetic and secretory process responsible for aflatoxin contamination. b) Using biocompetitive agents that replace aflatoxigenic strains with non aflatoxigenic strains in the field. c) Using genetic engineering techniques to incorporate antifungal genes into specific plant species.

  15. Urban Airborne Lead: X-Ray Absorption Spectroscopy Establishes Soil as Dominant Source

    PubMed Central

    Pingitore, Nicholas E.; Clague, Juan W.; Amaya, Maria A.; Maciejewska, Beata; Reynoso, Jesús J.

    2009-01-01

    Background Despite the dramatic decrease in airborne lead over the past three decades, there are calls for regulatory limits on this potent pediatric neurotoxin lower even than the new (2008) US Environmental Protection Agency standard. To achieve further decreases in airborne lead, what sources would need to be decreased and what costs would ensue? Our aim was to identify and, if possible, quantify the major species (compounds) of lead in recent ambient airborne particulate matter collected in El Paso, TX, USA. Methodology/Principal Findings We used synchrotron-based XAFS (x-ray absorption fine structure) to identify and quantify the major Pb species. XAFS provides molecular-level structural information about a specific element in a bulk sample. Pb-humate is the dominant form of lead in contemporary El Paso air. Pb-humate is a stable, sorbed complex produced exclusively in the humus fraction of Pb-contaminated soils; it also is the major lead species in El Paso soils. Thus such soil must be the dominant source, and its resuspension into the air, the transfer process, providing lead particles to the local air. Conclusions/Significance Current industrial and commercial activity apparently is not a major source of airborne lead in El Paso, and presumably other locales that have eliminated such traditional sources as leaded gasoline. Instead, local contaminated soil, legacy of earlier anthropogenic Pb releases, serves as a long-term reservoir that gradually leaks particulate lead to the atmosphere. Given the difficulty and expense of large-scale soil remediation or removal, fugitive soil likely constrains a lower limit for airborne lead levels in many urban settings. PMID:19340295

  16. Endotoxins in baled cottons and airborne dusts in textile mills in the People's Republic of China.

    PubMed Central

    Olenchock, S A; Christiani, D C; Mull, J C; Ye, T T; Lu, P L

    1983-01-01

    Bulk cotton samples and airborne vertical elutriated cotton dusts were obtained from textile mills in Shanghai, People's Republic of China. Analysis of endotoxin contents revealed that baled cottons which were grown in different countries varied in endotoxin contamination. The two textile mills, which operated at similar overall airborne dust levels, differed markedly in the levels of airborne endotoxins. The data suggest that the biological activity or "toxicity" of airborne cotton dusts may not be correlated directly with gravimetric dust levels. PMID:6639029

  17. MIR Solar Array Return Experiment: Power Performance Measurements and Molecular Contamination Analysis Results

    NASA Technical Reports Server (NTRS)

    Visentine, James; Kinard, William; Brinker, David; Scheiman, David; Banks, Bruce; Albyn, Keith; Hornung, Steve; See, Thomas

    2001-01-01

    A solar array segment was recently removed from the Mir core module and returned for ground-based analysis. The segment, which is similar to the ones the Russians have provided for the FGB and Service Modules, was microscopically examined and disassembled by US and Russian science teams. Laboratory analyses have shown the segment to he heavily contaminated by an organic silicone coating, which was converted to an organic silicate film by reactions with atomic oxygen within the. orbital flight environment. The source of the contaminant was a silicone polymer used by the Russians as an adhesive and bonding agent during segment construction. During its life cycle, the array experienced a reduction in power performance from approx. 12%, when it was new and first deployed, to approx. 5%, when it was taken out of service. However, current-voltage measurements of three contaminated cells and three pristine, Russian standard cells have shown that very little degradation in solar array performance was due to the silicate contaminants on the solar cell surfaces. The primary sources of performance degradation is attributed to "thermal hot-spotting" or electrical arcing; orbital debris and micrometeoroid impacts; and possibly to the degradation of the solar cells and interconnects caused by radiation damage from high energy protons and electrons.

  18. MOLECULAR ANALYSIS OF MICROBIAL COMMUNITY STRUCTURES IN PRISTINE AND CONTAMINATED AQUIFERS: FIELD AND LABORATORY MICROCOSM EXPERIMENTS

    EPA Science Inventory

    This study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (FC) or aerobic and noncontaminted (NC) and (ii) examine alterations in micro...

  19. MOLECULAR TRACKING FECAL CONTAMINATION IN SURFACE WATERS: 16S RDNA VERSUS METAGENOMICS APPROACHES

    EPA Science Inventory

    Microbial source tracking methods need to be sensitive and exhibit temporal and geographic stability in order to provide meaningful data in field studies. The objective of this study was to use a combination of PCR-based methods to track cow fecal contamination in two watersheds....

  20. Molecular characterization of chicken infectious anemia virus from contaminated live-virus vaccines.

    PubMed

    Li, Yang; Hu, Yan; Cui, Shuai; Fu, Jiayuan; Wang, Yixin; Cui, Zhizhong; Fang, Lichun; Chang, Shuang; Zhao, Peng

    2016-11-02

    The aim of this study was to investigate possible causes of the pervasiveness of chicken infectious anemia virus ( CIAV: ) infection in chickens in recent years in China. A total of 14 batches of live-virus vaccines were examined using PCR to detect CIAV contamination, of which only 2 samples (a Newcastle disease vaccine and a fowl pox vaccine) tested positive for CIAV. These Newcastle and fowl pox vaccines were then inoculated into 1-day-old specific-pathogen-free chickens. Serum samples were collected from chickens infected with the PCR-positive vaccines, and these tested positive for CIAV-specific antibodies as tested using ELISA. In addition, DNA samples isolated from the serum samples also tested positive by PCR. The results indicated that the samples were contaminated with CIAV and identified 2 exogenous CIAV strains, designated CIAV-N22 and CIAV-F10, in the respective samples. The full genome sequences of these novel CIAV strains were sequenced and analyzed. Phylogenetic tree analysis indicated that the CIAV-F10 strain might represent a recombinant viral strain arising from the parental CIAV strains JQ690762 and KJ728816. Overall, the results suggested that vaccination with CIAV-contaminated vaccines contributed to the prevalence and spread of CIAV infection in chickens. Furthermore, the CIAV contaminant was likely subsequently transmitted to commercial chickens through congenital transmission. Our findings therefore highlight the need for more extensive screening of live-virus vaccines for poultry in China to reduce the threat of contamination with exogenous viruses.

  1. Prevention of optics and resist contamination in 300-mm lithography: improvements in chemical air filtration

    NASA Astrophysics Data System (ADS)

    Kinkead, Devon A.; Grayfer, Anatoly; Kishkovich, Oleg P.

    2001-08-01

    Atmospheric pressure deep UV lithography using fast chemically amplified photoresists will be the mainstay of semiconductor production into the foreseeable future. Airborne molecular contamination (AMC) in the form of bases and condensable organic and inorganic materials however, threaten both sensitive optics and modern resists thereby creating a host of yield limiting contamination issues. Past work by Kunz at MIT has described photo-induced organic contamination of lithographic optics as a significant concern in leading-edge lithography. Moreover, Kinkead and Ercken, and Kishkovich and Dean have published work on the impact of base contamination on CD uniformity in modern photoresists. Herein, the authors discuss solutions to control both optics and resist contamination in a single compact filter system for advanced lithography. The results of this work suggest that resist and optics contamination can be controlled as we enter the era of low K1 factor <150nm/300mm-device production.

  2. 1H NMR Metabolomics: A New Molecular Level Tool for Assessment of Organic Contaminant Bioavailability to Earthworms in Soil

    NASA Astrophysics Data System (ADS)

    McKelvie, J. R.; Wolfe, D. M.; Celejewski, M. A.; Simpson, A. J.; Simpson, M. J.

    2009-05-01

    At contaminated field sites, the complete removal of polycyclic aromatic hydrocarbons (PAHs) is rarely achieved since a portion of these compounds remain tightly bound to the soil matrix. The concentration of PAHs in soil typically decreases until a plateau is reached, at which point the remaining contaminant is considered non- bioavailable. Numerous soil extraction techniques, including cyclodextrin extraction, have been developed to estimate contaminant bioavailability. However, these are indirect methods that do not directly measure the response of organisms to chemical exposure in soil. Earthworm metabolomics offers a promising new way to directly evaluate the bioavailability and toxicity of contaminants in soil. Metabolomics involves the measurement of changes in small-molecule metabolites, including sugars and amino acids, in living organisms due to an external stress, such as contaminant exposure. The objective of this study was to compare cyclodextrin extraction of soil (a bioavailability proxy) and 1H NMR metabolomic analysis of aqueous earthworm tissue extracts as indicators of contaminant bioavailability. A 30 day laboratory experiment was conducted using phenanthrene-spiked sphagnum peat soil and the OECD recommended earthworm species for toxicity testing, Eisenia fetida. The initial phenanthrene concentration in the soil was 320 mg/kg. Rapid biodegradation of phenanthrene occurred and concentrations decreased to 16 mg/kg within 15 days. After 15 days, phenanthrene biodegradation slowed and cyclodextrin extraction of the soil suggested that phenanthrene was no longer bioavailable. Multivariate statistical analysis of the 1H NMR spectra for E. fetida tissue extracts indicated that the metabolic profile of phenanthrene exposed earthworms differed from control earthworms throughout the 30 day experiment. This suggests that the residual phenanthrene remaining in the soil after 15 days continued to elicit a metabolic response, even though it was not

  3. Molecular diversity of arbuscular mycorrhizal fungi in relation to soil chemical properties and heavy metal contamination.

    PubMed

    Zarei, Mehdi; Hempel, Stefan; Wubet, Tesfaye; Schäfer, Tina; Savaghebi, Gholamreza; Jouzani, Gholamreza Salehi; Nekouei, Mojtaba Khayam; Buscot, François

    2010-08-01

    Abundance and diversity of arbuscular mycorrhizal fungi (AMF) associated with dominant plant species were studied along a transect from highly lead (Pb) and zinc (Zn) polluted to non-polluted soil at the Anguran open pit mine in Iran. Using an established primer set for AMF in the internal transcribed spacer (ITS) region of rDNA, nine different AMF sequence types were distinguished after phylogenetic analyses, showing remarkable differences in their distribution patterns along the transect. With decreasing Pb and Zn concentration, the number of AMF sequence types increased, however one sequence type was only found in the highly contaminated area. Multivariate statistical analysis revealed that further factors than HM soil concentration affect the AMF community at contaminated sites. Specifically, the soils' calcium carbonate equivalent and available P proved to be of importance, which illustrates that field studies on AMF distribution should also consider important environmental factors and their possible interactions.

  4. Biological monitoring of airborne pollution

    SciTech Connect

    Ditz, D.W. )

    1990-01-01

    Common plants such as grasses, mosses, and even goldenrod may turn out to have a new high-tech role as monitors of airborne pollution from solid waste incinerators. Certain plants that respond to specific pollutants can provide continuous surveillance of air quality over long periods of time: they are bio-indicators. Other species accumulate pollutants and can serve as sensitive indicators of pollutants and of food-chain contamination: they are bio-accumulators. Through creative use of these properties, biological monitoring can provide information that cannot be obtained by current methods such as stack testing.

  5. Macroscopic and molecular-scale assessment of soil lead contamination impacted by seasonal dove hunting activities

    SciTech Connect

    Arai, Y.; Tappero, R.; Rick, A.R.; Saylor, T.; Faas, E. & Lanzirotti, A.

    2011-05-24

    Environmental contamination of lead (Pb) in soils and sediments poses serious threats to human and ecological health. The objective of this study is to investigate the effect of seasonal dove sports hunting activities on Pb contamination in acid forest soils. A grid sampling method was used to investigate the spatial distribution of Pb contamination in surface soils. Soils were analyzed for total metal(loid) concentration and characterized for physicochemical properties and mineralogy. Adsorption isotherm experiments were also conducted to understand the reactivity and retention capacity of Pb(II) in soils. Finally, synchrotron-based X-ray microprobe and X-ray absorption spectroscopy were used to understand the chemical speciation of Pb that controls the retention/release mechanisms of Pb in soils. There was no excessive accumulation of Pb at the site. However, the concentration of Pb in surface soils was greater than the background level (<16 mg kg{sup -1}). The contamination level of Pb was as high as 67 mg kg{sup -1} near a patch of corn field where lime was frequently applied. A microfocused X-ray microprobe analysis showed the presence of Pb pellet fragments that predominantly contain oxidized Pb(II), suggesting that oxidative dissolution was occurring in soils. Dissolved Pb(II) can be readily retained in soils up to {approx}3,600 mg kg{sup -1} via inner-sphere and outer-sphere surface complexation on carbon and aluminol functional groups of soil components, suggesting that partitioning reactions control the concentration of Pb in soil solution. The fate of Pb is likely to be controlled by (1) oxidative dissolution process of Pb(0) pellets and (2) the release of outer-sphere and/or inner-sphere Pb surface complexes in humic substances and aluminosilicate/Al oxyhydroxides. Although no remedial actions are immediately required, the long-term accumulation of Pb in soils should be carefully monitored in protecting ecosystem and water quality at the dove hunting

  6. {sup 26}Al AND THE FORMATION OF THE SOLAR SYSTEM FROM A MOLECULAR CLOUD CONTAMINATED BY WOLF-RAYET WINDS

    SciTech Connect

    Gaidos, Eric; Krot, Alexander N.; Williams, Jonathan P.; Raymond, Sean N. E-mail: sasha@higp.hawaii.edu E-mail: sean.raymond@colorado.edu

    2009-05-10

    In agreement with previous work, we show that the presence of the short-lived radionuclide (SLR) {sup 26}Al in the early solar system was unlikely (less than 2% a priori probability) to be the result of direct introduction of supernova (SN) ejecta into the gaseous disk during the Class II stage of protosolar evolution. We also show that Bondi-Hoyle accretion of any contaminated residual gas from the Sun's natal star cluster contributed negligible {sup 26}Al to the primordial solar system. Our calculations are consistent with the absence of the oxygen isotopic signature expected with any late introduction of SN ejecta into the protoplanetary disk. Instead, the presence of {sup 26}Al in the oldest solar system solids (calcium-aluminum-rich inclusions (CAIs)) and its apparent uniform distribution with the inferred canonical {sup 26}Al/{sup 27}Al ratio of (4.5-5) x 10{sup -5} support the inheritance of {sup 26}Al from the Sun's parent giant molecular cloud. We propose that this radionuclide originated in a prior generation of massive stars that formed in the same molecular cloud and contaminated that cloud by Wolf-Rayet winds. We calculated the Galactic distribution of {sup 26}Al/{sup 27}Al ratios that arise from such contamination using the established embedded cluster mass and stellar initial mass functions, published nucleosynthetic yields from the winds of massive stars, and by assuming rapid and uniform mixing into the cloud. Although our model predicts that the majority of stellar systems contain no {sup 26}Al from massive stars, and that the a priori probability that the {sup 26}Al/{sup 27}Al ratio will reach or exceed the canonical solar system value is only {approx}6%, the maximum in the distribution of nonzero values is close to the canonical {sup 26}Al/{sup 27}Al ratio. We find that the Sun most likely formed 4-5 million years (Myr) after the massive stars that were the source of {sup 26}Al. Furthermore, our model can explain the initial solar system

  7. LMWOA (low molecular weight organic acid) exudation by salt marsh plants: Natural variation and response to Cu contamination

    NASA Astrophysics Data System (ADS)

    Mucha, Ana P.; Almeida, C. Marisa R.; Bordalo, Adriano A.; Vasconcelos, M. Teresa S. D.

    2010-06-01

    This work aimed to evaluate, in vitro, the capability of roots of two salt marsh plants to release low molecular weight organic acids (LMWOAs) and to ascertain whether Cu contamination would stimulate or not organic acids exudation. The sea rush Juncus maritimus and the sea-club rush Scirpus maritimus, both from the lower Douro river estuary (NW Portugal), were used. Plants were collected seasonally, four times a year in 2004, during low tide. After sampling, plant roots were washed for removal of adherent particles and immersed for 2 h in a solution that matched salinity (3) and pH (7.5) of the pore water from the same location to obtain plant exudates. In one of the seasons, similar experiments were carried out but spiking the solution with different amounts of Cu in order to embrace the range between 0 and 1600 nM. In the final solutions as well as in sediment pore water LMWOAs were determined by high performance liquid chromatography. Plants were able to release, in a short period of time, relatively high amounts of LMWOAs (oxalate, citrate, malate, malonate, and succinate). In the sediment pore water oxalate, succinate and acetate were also detected. Therefore, plant roots probably contributed to the presence of some of these organic compounds in pore water. Exudation differed between the plant species and also showed some seasonally variation, particularly for S. maritimus. The release of oxalate by J. maritimus increased with Cu increase in the media. However, exudation of the other LMWOAs did not seem to be stimulated by Cu contamination in the media. This fact is compatible with the existence of alternative internal mechanisms for Cu detoxification, as denoted by the fact that in media contaminated with Cu both plant species accumulated relatively high amounts (29-83%) of the initially dissolved Cu. This study expands our knowledge on the contribution of globally dominant salt marsh plants to the release of LMWOAs into the environment.

  8. Efficiency of nanoscale zero-valent iron on the enhanced low molecular weight organic acid removal Pb from contaminated soil.

    PubMed

    Wang, Guiyin; Zhang, Shirong; Xu, Xiaoxun; Li, Ting; Li, Yun; Deng, Ouping; Gong, Guoshu

    2014-12-01

    The Pb removal efficiencies from contaminated soils by low molecular weight organic acid (LMWOA) and nanoscale zero-valent iron (nZVI) were investigated through batch soil washing experiments. Results showed that significant promotion on Pb-removal with the mixed solutions of LMWOA and nZVI (p < 0.05). The Pb removal efficiencies reached 64% and 83% for mine and farmland soil by addition of 0.2 M citric acid and 2.0 g L−1 nZVI, respectively. They decreased with increasing pH from 3 to 9. The mixed solutions of LMWOA and nZVI induced Pb(II) releases processes including a rapid desorption within 4 h and a slow desorption in the following hours. The second-order model was the most appropriate for describing the kinetic processes of Pb(II) desorption. The main fractions of Pb removal were exchangeable and reducible. Compared with LMWOA, the loss rates of nitrogen, phosphorus and potassium decreased after washing with the mixed solutions. Our study suggests that combining of LMWOA and nZVI would be a promising alternative approach for remediation Pb-contaminated soils.

  9. Molecular biomarkers to assess health risks due to environmental contaminants exposure.

    PubMed

    Poblete-Naredo, Irais; Albores, Arnulfo

    2016-06-03

    Biomarkers, or bioindicators, are metric tools that, when compared with reference values, allow specialists to perform risk assessments and provide objective information to decision makers to design effective strategies to solve health or environmental problems by efficiently using the resources assigned. Health risk assessment is a multidisciplinary exercise, and molecular biology is a discipline that greatly contributes to these evaluations because the genome, transcriptome, proteome and metabolome could be affected by xenobiotics causing measurable changes that might be useful biomarkers. Such changes may greatly depend on individual genetic background; therefore, the polymorphic distribution of exposed populations becomes an essential feature for adequate data interpretation. The aim of this paper is to offer an up-to-date review of the role of different molecular biomarkers in health risk assessments.

  10. Western Airborne Contaminants Assessment Project Database

    EPA Science Inventory

    WACAP has received considerable recognition from the media with over 200 local, national and international media outlets. At present count, 10 peer-reviewed papers have been published. In response to the WACAP results, the NPS convened multi-agency workshops with WACAP PIs and l...

  11. Nondestructive testing using air-borne ultrasound.

    PubMed

    Hsu, David K

    2006-12-22

    Over the last two decades, more efficient transducers were developed for the generation and reception of air-borne ultrasound, thus enabling the non-contact, non-contaminating inspection of composite laminates and honeycomb structures widely used in the aerospace industry. This paper presents the fundamentals of making air-borne ultrasonic measurement, and point out special considerations unique to propagating ultrasound in air and through solids. Transducer beam profile characterization, thickness dependence and resonance effects in the transmission of air-coupled ultrasound through plates, and the detection and imaging of defects and damage in solid laminates and honeycomb sandwich will be discussed and illustrated with examples. Finally, a manual scan system developed for implementing air-borne ultrasonic imaging in the field and on aircraft will be introduced.

  12. Airborne Microalgae: Insights, Opportunities, and Challenges

    PubMed Central

    Skjøth, Carsten Ambelas; Šantl-Temkiv, Tina; Löndahl, Jakob

    2016-01-01

    Airborne dispersal of microalgae has largely been a blind spot in environmental biological studies because of their low concentration in the atmosphere and the technical limitations in investigating microalgae from air samples. Recent studies show that airborne microalgae can survive air transportation and interact with the environment, possibly influencing their deposition rates. This minireview presents a summary of these studies and traces the possible route, step by step, from established ecosystems to new habitats through air transportation over a variety of geographic scales. Emission, transportation, deposition, and adaptation to atmospheric stress are discussed, as well as the consequences of their dispersal on health and the environment and state-of-the-art techniques to detect and model airborne microalga dispersal. More-detailed studies on the microalga atmospheric cycle, including, for instance, ice nucleation activity and transport simulations, are crucial for improving our understanding of microalga ecology, identifying microalga interactions with the environment, and preventing unwanted contamination events or invasions. PMID:26801574

  13. Molecular Analysis of Microbial Community Structures in Pristine and Contaminated Aquifers: Field and Laboratory Microcosm Experiments

    PubMed Central

    Shi, Y.; Zwolinski, M. D.; Schreiber, M. E.; Bahr, J. M.; Sewell, G. W.; Hickey, W. J.

    1999-01-01

    This study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (FC) or aerobic and noncontaminated (NC) and (ii) examine alterations in microbial community structures resulting from exposure to toluene and/or electron acceptor supplementation (nitrate). The latter objective was addressed by using the NC and FC aquifer materials for anaerobic microcosm studies in which phylogenetic probe analysis was complemented by microbial activity assays. Domain probe analysis of the aquifer samples showed that the communities were predominantly Bacteria; Eucarya and Archaea were not detectable. At the phylum and subclass levels, the FC and NC aquifer material had similar relative abundance distributions of 43 to 65% β- and γ-Proteobacteria (B+G), 31 to 35% α-Proteobacteria (ALF), 15 to 18% sulfate-reducing bacteria, and 5 to 10% high G+C gram positive bacteria. Compared to that of the NC region, the community structure of the FC material differed mainly in an increased abundance of B+G relative to that of ALF. The microcosm communities were like those of the field samples in that they were predominantly Bacteria (83 to 101%) and lacked detectable Archaea but differed in that a small fraction (2 to 8%) of Eucarya was detected regardless of the treatment applied. The latter result was hypothesized to reflect enrichment of anaerobic protozoa. Addition of nitrate and/or toluene stimulated microbial activity in the microcosms, but only supplementation of toluene alone significantly altered community structures. For the NC material, the dominant subclass shifted from B+G to ALF, while in the FC microcosms 55 to 65% of the Bacteria community was no longer identifiable by the phylum or subclass probes used. The latter result suggested that toluene exposure fostered the proliferation of phylotype(s) that were otherwise minor constituents of the

  14. The geochemical evolution of low-molecular-weight organic acids derived from the degradation of petroleum contaminants in groundwater

    USGS Publications Warehouse

    Cozzarelli, I.M.; Baedecker, M.J.; Eganhouse, R.P.; Goerlitz, D.F.

    1994-01-01

    The geochemical evolution of low-molecular-weight organic acids in groundwater downgradient from a crude-oil spill near Bemidji, Minnesota, was studied over a five year period (1986-1990). The organic acids are metabolic intermediates of the degradation of components of the crude oil and are structurally related to hydrocarbon precursors. The concentrations of organic acids, particularly aliphatic acids, increase as the microbial alteration of hydrocarbons progresses. The organic-acid pool changes in composition and concentration over time and in space as the degradation processes shift from Fe(III) reduction to methanogenesis. Over time, the aquifer system evolves into one in which the groundwater contains more oxidized products of hydrocarbon degradation and the reduced forms of iron, manganese, and nitrogen. Laboratory microcosm experiments with aquifer material support the hypothesis that organic acids observed in the groundwater originate from the microbial degradation of aromatic hydrocarbons under anoxic conditions. The geochemistry of two other shallow aquifers in coastal plain sediments, one contaminated with creosote waste and the other with gasoline, were compared to the Bemidji site. The geochemical evolution of the low-molecular-weight organic acid pool in these systems is controlled, in part, by the presence of electron acceptors available for microbially mediated electron-transfer reactions. The depletion of electron acceptors in aquifers leads to the accumulation of aliphatic organic acids in anoxic groundwater. ?? 1994.

  15. Molecular analysis of phosphate limitation in Geobacteraceae during the bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    N'Guessan, A. Lucie; Elifantz, H.; Nevin, Kelly P.; Mouser, Paula; Methe, Barbara; Woodard, Trevor L.; Manley, Kimberley; Williams, Kenneth H.; Wilkins, Michael J.; Larsen, Joern T.; Long, Philip E.; Lovley, Derek R.

    2010-01-10

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphatelimitation were identified by microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high-affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU upregulated the most. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium-bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve because of the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  16. Molecular analysis of phosphate limitation in Geobacteraceae during the bioremediation of a uranium-contaminated aquifer

    SciTech Connect

    N'Guessan, L.A.; Elifantz, H.; Nevin, K.P.; Mouser, P.J.; Methe, B.; Woodard, T. L.; Manley, K.; Williams, K. H.; Wilkins, M. J.; Larsen, J.T.; Long, P. E.; Lovley, D. R.

    2009-09-01

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  17. Molecular Analysis of Phosphate Limitation in Geobacteraceae During the Bioremediation of a Uranium-Contaminated Aquifer

    SciTech Connect

    N'Guessan, A. Lucie; Elifantz, H.; Nevin, Kelly P.; Mouser, Paula; Methe, Barbara; Woodard, Trevor L.; Manley, Kimberley; Williams, Kenneth H.; Wilkins, Michael J.; Larsen, Joern T.; Long, Philip E.; Lovley, Derek R.

    2010-02-01

    Nutrient limitation is an environmental stress that may reduce the effectiveness of bioremediation strategies, especially when the contaminants are organic compounds or when organic compounds are added to promote microbial activities such as metal reduction. Genes indicative of phosphate-limitation were identified via microarray analysis of chemostat cultures of Geobacter sulfureducens. This analysis revealed that genes in the pst-pho operon, which is associated with a high affinity phosphate uptake system in other microorganisms, had significantly higher transcript abundance under phosphate-limiting conditions, with the genes pstB and phoU the most up-regulated. Quantitative PCR analysis of pstB and phoU transcript levels in G. sulfurreducens grown in chemostats demonstrated that the expression of these genes increased when phosphate was removed from the culture medium. Transcripts of pstB and phoU within the subsurface Geobacter species predominating during an in situ uranium bioremediation field experiment were more abundant than in chemostat cultures of G. sulfurreducens that were not limited for phosphate. Addition of phosphate to incubations of subsurface sediments did not stimulate dissimilatory metal reduction. The added phosphate was rapidly adsorbed onto the sediments. The results demonstrate that Geobacter species can effectively reduce U(VI) even when experiencing suboptimal phosphate concentrations and that increasing phosphate availability with phosphate additions is difficult to achieve due to the high reactivity of this compound. This transcript-based approach developed for diagnosing phosphate limitation should be applicable to assessing the potential need for additional phosphate in other bioremediation processes.

  18. Selective removal of diclofenac from contaminated water using molecularly imprinted polymer microspheres.

    PubMed

    Dai, Chao-Meng; Geissen, Sven-Uwe; Zhang, Ya-Lei; Zhang, Yong-Jun; Zhou, Xue-Fei

    2011-06-01

    A molecularly imprinted polymer (MIP) was synthesized by precipitation polymerization using diclofenac (DFC) as a template. Binding characteristics of the MIP were evaluated using equilibrium binding experiments. Compared to the non-imprinted polymer (NIP), the MIP showed an outstanding affinity towards DFC in an aqueous solution with a binding site capacity (Q(max)) of 324.8 mg/g and a dissociation constant (K(d)) of 3.99 mg/L. The feasibility of removing DFC from natural water by the MIP was demonstrated by using river water spiked with DFC. Effects of pH and humic acid on the selectivity and adsorption capacity of MIP were evaluated in detail. MIP had better selectivity and higher adsorption efficiency for DFC as compared to that of powdered activated carbon (PAC). In addition, MIP reusability was demonstrated for at least 12 repeated cycles without significant loss in performance, which is a definite advantage over single-use activated carbon.

  19. Molecular typing of the Legionella pneumophila population isolated from several locations in a contaminated water network.

    PubMed

    Lepeuple, A S; Jovic, M; de Roubin, M R

    2004-01-01

    The RAPD (random amplified polymorphic DNA) technique has been developed for the molecular typing of Legionella in order to characterise the populations of hot water systems. During this study, 22 primers were tested and the four most informative ones were selected. The optimisation of the PCR conditions allowed the setting up of a powerful discriminative genotyping method. Moreover, the definition of a quality management method allowed definition of the key steps and the number of replicates to ensure reproducibility of the RAPD pattern. The RAPD was used to study the hot water network of a building. Legionella colonies (91) were isolated from seven locations and genotyped. The diversity of the population in one sample could vary from one to seven different strains. The study of the traceability showed that, in most of the cases, different populations could be present at different locations of the same network.

  20. Contamination study

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry; Herren, Kenneth A.

    1990-01-01

    The time dependence of the angular reflectance from molecularly contaminated optical surfaces in the Vacuum Ultraviolet (VUV) is measured. The light scattering measurements are accomplished in situ on optical surfaces in real time during deposition of molecular contaminants. The measurements are taken using non-coherent VUV sources with the predominant wavelengths being the Krypton resonance lines at 1236 and 1600 A. Detection of the scattered light is accomplished using a set of three solar blind VUV photomultipliers. An in-plane VUV BRDF (Bidirectional Reflectance Distribution Functions) experiment is described and details of the ongoing program to characterize optical materials exposed to the space environment is reported.

  1. Understanding star formation in molecular clouds. I. Effects of line-of-sight contamination on the column density structure

    NASA Astrophysics Data System (ADS)

    Schneider, N.; Ossenkopf, V.; Csengeri, T.; Klessen, R. S.; Federrath, C.; Tremblin, P.; Girichidis, P.; Bontemps, S.; André, Ph.

    2015-03-01

    Column-density maps of molecular clouds are one of the most important observables in the context of molecular cloud- and star-formation (SF) studies. With the Herschel satellite it is now possible to precisely determine the column density from dust emission, which is the best tracer of the bulk of material in molecular clouds. However, line-of-sight (LOS) contamination from fore- or background clouds can lead to overestimating the dust emission of molecular clouds, in particular for distant clouds. This implies values that are too high for column density and mass, which can potentially lead to an incorrect physical interpretation of the column density probability distribution function (PDF). In this paper, we use observations and simulations to demonstrate how LOS contamination affects the PDF. We apply a first-order approximation (removing a constant level) to the molecular clouds of Auriga and Maddalena (low-mass star-forming), and Carina and NGC 3603 (both high-mass SF regions). In perfect agreement with the simulations, we find that the PDFs become broader, the peak shifts to lower column densities, and the power-law tail of the PDF for higher column densities flattens after correction. All corrected PDFs have a lognormal part for low column densities with a peak at Av ~ 2 mag, a deviation point (DP) from the lognormal at Av(DP) ~ 4-5 mag, and a power-law tail for higher column densities. Assuming an equivalent spherical density distribution ρ ∝ r- α, the slopes of the power-law tails correspond to αPDF = 1.8, 1.75, and 2.5 for Auriga, Carina, and NGC 3603. These numbers agree within the uncertainties with the values of α ≈ 1.5,1.8, and 2.5 determined from the slope γ (with α = 1-γ) obtained from the radial column density profiles (N ∝ rγ). While α ~ 1.5-2 is consistent with a structure dominated by collapse (local free-fall collapse of individual cores and clumps and global collapse), the higher value of α > 2 for NGC 3603 requires a physical

  2. Airborne influenza virus detection with four aerosol samplers using molecular and infectivity assays: considerations for a new infectious virus aerosol sampler

    PubMed Central

    Fabian, P.; McDevitt, J. J.; Houseman, E. A.; Milton, D. K.

    2013-01-01

    As a first step in conducting studies of airborne influenza transmission, we compared the collection performance of an SKC Biosampler, a compact cascade impactor (CCI), Teflon filters, and gelatin filters by collecting aerosolized influenza virus in a one-pass aerosol chamber. Influenza virus infectivity was determined using a fluorescent focus assay and influenza virus nucleic acid (originating from viable and non-viable viruses) was measured using quantitative PCR. The results showed that the SKC Biosampler recovered and preserved influenza virus infectivity much better than the other samplers – the CCI, Teflon, and gelatin filters recovered only 7–22% of infectious viruses compared with the Biosampler. Total virus collection was not significantly different among the SKC Biosampler, the gelatin, and Teflon filters, but was significantly lower in the CCI. Results from this study show that a new sampler is needed for virus aerosol sampling, as commercially available samplers do not efficiently collect and conserve virus infectivity. Applications for a new sampler include studies of airborne disease transmission and bioterrorism monitoring. Design parameters for a new sampler include high collection efficiency for fine particles and liquid sampling media to preserve infectivity. PMID:19689447

  3. Molecular analysis of microbial community structures in pristine and contaminated aquifers--Field and laboratory microcosm experiments

    USGS Publications Warehouse

    Shi, Y.; Zwolinski, M.D.; Schreiber, M.E.; Bahr, J.M.; Sewell, G.W.; Hickey, W.J.

    1999-01-01

    Molecular Analysis of Microbial Community Structures in Pristine and Contaminated Aquifers: Field and Laboratory Microcosm Experimentsvar callbackToken='531E8ACDB6C8511'; var subCode='asmjournal_sub'; var OAS_sitepage = 'aem.asm.org'; This study used phylogenetic probes in hybridization analysis to (i) determine in situ microbial community structures in regions of a shallow sand aquifer that were oxygen depleted and fuel contaminated (FC) or aerobic and noncontaminated (NC) and (ii) examine alterations in microbial community structures resulting from exposure to toluene and/or electron acceptor supplementation (nitrate). The latter objective was addressed by using the NC and FC aquifer materials for anaerobic microcosm studies in which phylogenetic probe analysis was complemented by microbial activity assays. Domain probe analysis of the aquifer samples showed that the communities were predominantlyBacteria; Eucarya and Archaea were not detectable. At the phylum and subclass levels, the FC and NC aquifer material had similar relative abundance distributions of 43 to 65% β- and γ-Proteobacteria (B+G), 31 to 35% α-Proteobacteria (ALF), 15 to 18% sulfate-reducing bacteria, and 5 to 10% high G+C gram positive bacteria. Compared to that of the NC region, the community structure of the FC material differed mainly in an increased abundance of B+G relative to that of ALF. The microcosm communities were like those of the field samples in that they were predominantly Bacteria (83 to 101%) and lacked detectable Archaea but differed in that a small fraction (2 to 8%) of Eucarya was detected regardless of the treatment applied. The latter result was hypothesized to reflect enrichment of anaerobic protozoa. Addition of nitrate and/or toluene stimulated microbial activity in the microcosms, but only supplementation of toluene alone significantly altered community structures. For the NC material, the dominant subclass shifted from B+G to ALF, while in the FC microcosms 55 to 65

  4. Molecular detection of Giardia contamination in water bodies in a zoo.

    PubMed

    Lim, Yvonne A L; Lai, Monica M; Mahdy, Mohammed A K; Mat Naim, H R; Smith, Huw V

    2009-10-01

    We used a combined microscopy-molecular approach to determine the occurrence and identities of waterborne Giardia sp. cysts isolated from 18 separate, 10l grab samples collected from a Malaysian zoo. Microscopy revealed that 17 of 18 samples were Giardia cyst positive with concentrations ranging from 1 to 120 cysts/l. Nine (52.9%) of the 17 cyst positive samples produced amplicons of which 7 (77.8%) could be sequenced. Giardia duodenalis assemblage A (6 of 7) and assemblage B (1 of 7), both infectious to humans, were identified at all sampling sites at the zoo. The presence of human infectious cysts raises public health issues, and their occurrence, abundance and sources should be investigated further. In this zoo setting, our data highlight the importance of incorporating environmental sampling (monitoring) in addition to routine faecal examinations to determine veterinary and public health risks, and water monitoring should be considered for inclusion as a separate element in hazard analysis, as it often has a historical (accumulative) connotation.

  5. Removal of probable human carcinogenic polycyclic aromatic hydrocarbons from contaminated water using molecularly imprinted polymer.

    PubMed

    Krupadam, Reddithota J; Khan, Muntazir S; Wate, Satish R

    2010-02-01

    A molecularly imprinted polymer (MIP) adsorbent for carcinogenic polycyclic aromatic hydrocarbons (PAHs) was prepared using a non-covalent templating technique. MIP particles sized from 2 to 5 microm were synthesized in acetonitrile by using six PAHs mix as a template, methacrylic acid as the functional monomer, and ethylene glycol dimethacrylate as the cross-linker. When compared with the non-imprinted polymer (NIP), the MIP showed an excellent affinity towards PAHs in aqueous solution with binding capacity (B(max)) of 687 microg g(-1)MIP, imprinting effect of 6, and a dissociation constant of 24 microM. The MIP exhibited significant binding affinity towards PAHs even in the presence of environmental parameters such as dissolved organic matter (COD) and total dissolved inorganic solids (TDS), suggesting that this material may be appropriate for removal of carcinogenic PAHs. The feasibility of removing PAHs from water by the MIP demonstrated using groundwater spiked with PAHs. In addition, the MIP reusability without any deterioration in performance was demonstrated at least ten repeated cycles.

  6. Sampling for Airborne Radioactivity

    DTIC Science & Technology

    2007-10-01

    compared to betas, gammas and neutrons. For an airborne radioactivity detection system, it is most important to be able to detect alpha particles and... Airborne radioactive particles may emit alpha, beta, gamma or neutron radiation, depending on which radioisotope is present. From a health perspective...

  7. Advanced sample preparation for the molecular quantification of Staphylococcus aureus in artificially and naturally contaminated milk.

    PubMed

    Aprodu, Iuliana; Walcher, Georg; Schelin, Jenny; Hein, Ingeborg; Norling, Börje; Rådström, Peter; Nicolau, Anca; Wagner, Martin

    2011-03-01

    Sample treatment is an essential element when using real-time PCR for quantification of pathogens directly on food samples. This study comparatively evaluated three different principles of sample treatment, i.e. immunomagnetic separation based on phage-derived cell wall binding molecules, matrix solubilization and flotation, in order to establish their suitability for quantifying low numbers of Staphylococcus aureus in milk. All three procedures succeeded to remove S. aureus from the milk matrix, either raw or pasteurized, and, as a result of the concentration of the target cells, minimized the effect of milk associated PCR inhibitors. Sample preparation based on immunomagnetic separation albeit of being user friendly, specific and rapid, failed to allow quantification of low and medium numbers (<10(4)CFU) of S. aureus. In a mastitic milk model cell wall binding domain (CBD)-based target cell extraction revealed results most closely matching those derived from culture-based quantification. Both matrix lysis and flotation allowed quantification of S. aureus at a level of 1-10 cells per ml. Both methods resulted in higher numbers of bacterial cell equivalents (bce) than plating could reveal. Since both methods harvest cells that have been subjected to either mechanical and chemical stresses before quantification, we concluded that the higher bce numbers resulted from a disaggregation of S. aureus clusters initially present in the inoculum. Conclusively, since likely each S. aureus cell of a toxigenic strain contributes to enterotoxin production, molecular quantification could provide an even more realistic impact assessment in outbreak investigations than plating does.

  8. Combined effects of low-molecular-weight organic acids on mobilization of arsenic and lead from multi-contaminated soils.

    PubMed

    Onireti, Olaronke O; Lin, Chuxia; Qin, Junhao

    2017-03-01

    A batch experiment was conducted to examine the combined effects of three common low-molecular-weight organic acids (LMWOAs) on the mobilization of arsenic and lead in different types of multi-contaminated soils. The capacity of individual LMWOAs (at a same molar concentration) to mobilize soil-borne As and Pb varied significantly. The combination of the organic acids did not make a marked "additive" effect on the mobilization of the investigated three elements. An "antagonistic" effect on element mobilization was clear in the treatments involving oxalic acid for some soils. The acid strength of a LMWOA did not play an important role in controlling the mobilization of elements. While the mobilization of As and Pb was closely associated with the dissolution of soil-borne Fe, soil properties such as original soil pH, organic matter contents and the total amount of the element relative to the total Fe markedly complicated the mobility of that element. Aging led to continual consumption of proton introduced from addition of LMWOAs and consequently caused dramatic changes in solution-borne Fe, which in turn resulted in change in As and Pb in the soil solution though different elements behaved differently.

  9. Molecular Characterization of Salmonella Serovars Anatum and Ealing Associated with Two Historical Outbreaks, Linked to Contaminated Powdered Infant Formula

    PubMed Central

    Gunn, Lynda; Finn, Sarah; Hurley, Daniel; Bai, Li; Wall, Ellen; Iversen, Carol; Threlfall, John E.; Fanning, Séamus

    2016-01-01

    Powdered infant formula (PIF) is not intended to be produced as a sterile product unless explicitly stated and on occasion may become contaminated during production with pathogens such as Salmonella enterica. This retrospective study focused on two historically reported salmonellosis outbreaks associated with PIF from the United Kingdom and France, in 1985 and 1996/1997. In this paper, the molecular characterization of the two outbreaks associated Salmonella serovars Anatum and Ealing is reported. Initially the isolates were analyzed using pulsed-field gel electrophoresis (PFGE), which revealed the clonal nature of the two outbreaks. Following from this two representative isolates, one from each serovar was selected for whole genome sequencing (WGS), wherein analysis focused on the Salmonella pathogenicity islands. Furthermore, the ability of these isolates to survive the host intercellular environment was determined using an ex vivo gentamicin protection assay. Results suggest a high level of genetic diversity that may have contributed to survival and virulence of isolates from these outbreaks. PMID:27818652

  10. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

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

  11. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

    After 20 years of development efforts, the airborne gravity survey has finally become a practical exploration method. Besides gravity data, the airborne survey can also collect simultaneous, continuous records of high-precision magneticfield data as well as terrain clearance; these provide a topographic contour map useful in calculating terrain conditions and in subsequent planning and engineering. Compared with a seismic survey, the airborne gravity method can cover the same area much more quickly and cheaply; a seismograph could then detail the interesting spots.

  12. Different low-molecular-mass organic acids specifically control leaching of arsenic and lead from contaminated soil.

    PubMed

    Ash, Christopher; Tejnecký, Václav; Borůvka, Luboš; Drábek, Ondřej

    2016-04-01

    Low-molecular-mass organic acids (LMMOA) are of key importance for mobilisation and fate of metals in soil, by functioning as ligands that increase the amount of dissolved metal in solution or by dissociation of metal binding minerals. Column leaching experiments were performed on soil polluted with As and Pb, in order to determine the specificity of LMMOA related release for individual elements, at varying organic acid concentrations. Acetic, citric and oxalic acids were applied in 12h leaching experiments over a concentration range (0.5-25 mM) to soil samples that represent organic and mineral horizons. The leaching of As followed the order: oxalic>citric>acetic acid in both soils. Arsenic leaching was attributed primarily to ligand-enhanced dissolution of mineral oxides followed by As released into solution, as shown by significant correlation between oxalic and citric acids and content of Al and Fe in leaching solutions. Results suggest that subsurface mineral soil layers are more vulnerable to As toxicity. Leaching of Pb from both soils followed the order: citric>oxalic>acetic acid. Mineral soil samples were shown to be more susceptible to leaching of Pb than samples characterised by a high content of organic matter. The leaching efficiency of citric acid was attributed to formation of stable complexes with Pb ions, which other acids are not capable of. Results obtained in the study are evidence that the extent of As and Pb leaching in contaminated surface and subsurface soil depends significantly on the types of carboxylic acid involved. The implications of the type of acid and the specific element that can be mobilised become increasingly significant where LMMOA concentrations are highest, such as in rhizosphere soil.

  13. A molecular-based approach for examining responses of eukaryotes in microcosms to contaminant-spiked estuarine sediments.

    PubMed

    Chariton, Anthony A; Ho, Kay T; Proestou, Dina; Bik, Holly; Simpson, Stuart L; Portis, Lisa M; Cantwell, Mark G; Baguley, Jeffrey G; Burgess, Robert M; Pelletier, Marguerite M; Perron, Monique; Gunsch, Claudia; Matthews, Robin A

    2014-02-01

    Ecotoxicological information for most contaminants is limited to a small number of taxa, and these are generally restricted to comparatively hardy organisms that are readily extractable from test media and easily identifiable. Advances in DNA sequencing can now provide a comprehensive view of benthic invertebrate diversity. The authors applied 454 pyrosequencing to examine the responses of benthic communities in microcosms exposed to sediments with elevated concentrations of triclosan, the endpoint being eukaryl communities that have successfully vertically migrated through the manipulated sediments. The biological communities associated with the 3 treatments (control triclosan, low triclosan [14 mg/kg], and high triclosan [180 mg/kg]) clustered into 3 groups: control/low (n = 6 controls and 4 low), moderate (n = 2 low), and high (n = 5 high). One sample was discarded as an outlier. The most pronounced change as a response to triclosan was the loss of number of metazoan operational taxonomic units (OTUs), indicative of the control/low and moderate groups, with this being most evident in the range of taxa associated with the classes Chromadorea and Bivalvia and the phylum Kinorhyncha. The authors also describe a range of other taxa that aided discrimination between the groups; compare findings with traditionally obtained meio- and macrofaunal communities obtained from the same experiment; and illustrate some of the advantages and limitations associated with both the molecular and traditional approaches. The described approach illustrates the capacity for amplicon sequencing to provide ecologically relevant information that can be used to strengthen an understanding of how sedimentary communities respond to a range of environmental stressors.

  14. Different low-molecular-mass organic acids specifically control leaching of arsenic and lead from contaminated soil

    NASA Astrophysics Data System (ADS)

    Ash, Christopher; Tejnecký, Václav; Borůvka, Luboš; Drábek, Ondřej

    2016-04-01

    Low-molecular-mass organic acids (LMMOA) are of key importance for mobilisation and fate of metals in soil, by functioning as ligands that increase the amount of dissolved metal in solution or by dissociation of metal binding minerals. Column leaching experiments were performed on soil polluted with As and Pb, in order to determine the specificity of LMMOA related release for individual elements, at varying organic acid concentrations. Acetic, citric and oxalic acids were applied in 12 h leaching experiments over a concentration range (0.5-25 mM) to soil samples that represent organic and mineral horizons. The leaching of As followed the order: oxalic > citric > acetic acid in both soils. Arsenic leaching was attributed primarily to ligand-enhanced dissolution of mineral oxides followed by As released into solution, as shown by significant correlation between oxalic and citric acids and content of Al and Fe in leaching solutions. Results suggest that subsurface mineral soil layers are more vulnerable to As toxicity. Leaching of Pb from both soils followed the order: citric > oxalic > acetic acid. Mineral soil samples were shown to be more susceptible to leaching of Pb than samples characterised by a high content of organic matter. The leaching efficiency of citric acid was attributed to formation of stable complexes with Pb ions, which other acids are not capable of. Results obtained in the study are evidence that the extent of As and Pb leaching in contaminated surface and subsurface soil depends significantly on the types of carboxylic acid involved. The implications of the type of acid and the specific element that can be mobilised become increasingly significant where LMMOA concentrations are highest, such as in rhizosphere soil.

  15. Unnecessary roughness? Testing the hypothesis that predators destined for molecular gut-content analysis must be hand-collected to avoid cross-contamination.

    PubMed

    Greenstone, Matthew H; Weber, Donald C; Coudron, Thomas C; Payton, Mark E

    2011-03-01

    Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Mass-collection methods, such as sweep-netting, vacuum sampling and foliage beating, could lead to regurgitation or rupturing of predators along with uneaten prey, thereby contaminating specimens and compromising resultant gut-content data. Proponents of this 'cross-contamination hypothesis' advocate hand-collection as the best way to avoid cross-contamination. However, hand-collection is inefficient when large samples are needed, as with most ecological research. We tested the cross-contamination hypothesis by setting out onto potato plants immature Coleomegilla maculata and Podisus maculiventris that had been fed larvae of either Leptinotarsa decemlineata or Leptinotarsa juncta, or unfed individuals of these predator species along with L. decemlineata larvae. The animals were then immediately re-collected, either by knocking them vigorously off the plants onto a beat cloth and capturing them en masse with an aspirator ('rough' treatment) or by hand-searching and collection with a brush ('best practice'). Collected predators were transferred in the field to individual vials of chilled ethanol and subsequently assayed by PCR for fragments of cytochrome oxidase I of L. decemlineata and L. juncta. Ten to 39 per cent of re-collected fed predators tested positive by PCR for DNA of both Leptinotarsa species, and 14-38% of re-collected unfed predators contained L. decemlineata DNA. Overall levels of cross-contamination in the rough (31%) and best-practice (11%) samples were statistically different and supported the cross-contamination hypothesis. A pilot study on eliminating external DNA contamination with bleach prior to DNA extraction and amplification gave promising results.

  16. Occurrence and suitability of pharmaceuticals and personal care products as molecular markers for raw wastewater contamination in surface water and groundwater.

    PubMed

    Tran, Ngoc Han; Li, Jinhua; Hu, Jiangyong; Ong, Say Leong

    2014-03-01

    This study aimed to provide the first and comprehensive data on the occurrence of 17 target pharmaceuticals and personal care products (PPCPs) in urban water environment in Singapore. Meanwhile, this study also verified the suitability of these PPCPs as specific markers of raw wastewater contamination in receiving water bodies in highly urbanized areas where both surface water and groundwater are not impacted by the discharge of treated wastewater effluents. Analytical results of wastewater showed that among 17 target PPCPs examined, only 5 PPCPs were detected in 100 % of raw wastewater samples, including acetaminophen (ACT), carbamazepine (CBZ), caffeine (CF), diethyltoluamide (DEET), and salicylic acid (SA). Similarly, these PPCPs were found in most surface water and groundwater. Interestingly, the three PPCPs (ACT, CBZ, and SA) were only detected in surface water and groundwater in the sampling sites close to relatively older sewer systems, while they were absent in background samples that were collected from the catchment with no known wastewater sources. This suggests that ACT, CBZ, and SA can be used as specific molecular markers of raw wastewater in surface water and groundwater. This study also confirmed that CF and DEET were not really associated with wastewater sources, thus cannot serve well as specific molecular markers of wastewater contamination in receiving water bodies. To the best knowledge of the authors, the use of ACT and SA as specific molecular markers of raw wastewater contamination in urban surface waters and groundwater was first reported. Further studies on the use of ACT, CBZ, and SA along with other chemical/microbial markers are recommended to identify and differentiate contamination sources of surface waters/groundwater.

  17. Airborne Next: Rethinking Airborne Organization and Applying New Concepts

    DTIC Science & Technology

    2015-06-01

    structures since its employment on a large scale during World War II. It is puzzling to consider how little airborne organizational structures and employment...future potential of airborne concepts by rethinking traditional airborne organizational structures and employment concepts. Using a holistic approach in... structures of airborne forces to model a “small and many” approach over a “large and few” approach, while incorporating a “swarming” concept. Utilizing

  18. The use of the Molecular Adsorber Coating technology to mitigate vacuum chamber contamination during Pathfinder testing for the James Webb Space Telescope

    NASA Astrophysics Data System (ADS)

    Abraham, Nithin S.; Hasegawa, Mark M.; Wooldridge, Eve M.; Henderson-Nelson, Kelly A.

    2016-09-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground based space applications, in particular, for vacuum chamber environments. This paper describes the recent use of the MAC technology during Pathfinder testing of the Optical Ground Support Equipment (OGSE) for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap persistent outgassed contaminants, specifically silicone based diffusion pump oil, from within JSC's cryogenic optical vacuum chamber test facility called Chamber A. This paper summarizes the sample fabrication, installation, laboratory testing, post-test chemical analysis results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination.

  19. The Use of the Molecular Adsorber Coating Technology to Mitigate Vacuum Chamber Contamination During Pathfinder Testing for the James Webb Space Telescope

    NASA Technical Reports Server (NTRS)

    Abraham, Nithin S.; Hasegawa, Mark M.; Wooldridge, Eve M.; Henderson-Nelson, Kelly A.

    2016-01-01

    As a coating made of highly porous zeolite materials, the Molecular Adsorber Coating (MAC) was developed to capture outgassed molecular contaminants, such as hydrocarbons and silicones. For spaceflight applications, the adsorptive capabilities of the coating can alleviate on-orbit outgassing concerns on or near sensitive surfaces and instruments within the spacecraft. Similarly, this sprayable paint technology has proven to be significantly beneficial for ground based space applications, in particular, for vacuum chamber environments. This paper describes the recent use of the MAC technology during Pathfinder testing of the Optical Ground Support Equipment (OGSE) for the James Webb Space Telescope (JWST) at NASA Johnson Space Center (JSC). The coating was used as a mitigation tool to entrap persistent outgassed contaminants, specifically silicone based diffusion pump oil, from within JSC's cryogenic optical vacuum chamber test facility called Chamber A. This paper summarizes the sample fabrication, installation, laboratory testing, post-test chemical analysis results, and future plans for the MAC technology, which was effectively used to protect the JWST test equipment from vacuum chamber contamination.

  20. Biochemical analysis of cultured chorionic villi for the prenatal diagnosis of peroxisomal disorders: biochemical thresholds and molecular sensitivity for maternal cell contamination detection

    PubMed Central

    Steinberg, S; Katsanis, S; Moser, A; Cutting, G

    2005-01-01

    Objectives: The prenatal diagnosis of peroxisomal disorders is most often performed by biochemical analysis of cultured chorionic villus sample (CVS) or amniocytes. We aimed to (a) highlight the risk of maternal cell contamination (MCC) in biochemical prenatal diagnosis, (b) establish the threshold of these biochemical assays to MCC, and (c) document the sensitivity of PCR based genotyping of microsatellites for the detection of MCC in prenatal diagnosis of inborn errors by biochemical analysis. Methods: The threshold of each biochemical assay was assessed by co-cultivating fibroblasts from known affected and normal individuals. Genotypes for three polymorphic loci were determined by PCR and GeneScan analysis. The sensitivity of the molecular test was determined by DNA mixing experiments and isolation of DNA from co-cultivated fibroblasts. Results: MCC was detected in 2.5% of at risk CVS cultures (n = 79). Co-cultivation of defective and normal fibroblasts demonstrated that the peroxisomal biochemical assays were accurate at 25% contamination. Very low level DNA or cell contamination (1–5%) was detectable by genotyping, but an allele did not yield a definitive peak based on morphology until ∼10% contamination. Furthermore, we demonstrated that other inborn errors of metabolism might be more susceptible to diagnostic error by low level MCC. Conclusion: The sensitivity of the microsatellite analysis (⩾10%) is well within the threshold of peroxisomal biochemical assays. Although peroxisomal biochemical assays would not be predicted to introduce a false positive or negative result if MCC <10% were present but not recognised by molecular analysis, the same may not be true for other inborn errors of metabolism. PMID:15635073

  1. First acyclic diene metathesis polymerization under biphasic conditions using a dicationic ruthenium alkylidene: access to high-molecular-weight polymers with very low ruthenium contamination.

    PubMed

    Zhao, Jing; Wang, Dongren; Autenrieth, Benjamin; Buchmeiser, Michael R

    2015-01-01

    The acyclic diene metathesis (ADMET) polymerization of 6-hydroxy-1,10-undecadiene (M1) and 6-acetoxy-1,10-undecadiene (M2) by the action of two different catalysts, i.e., the second-generation Grubbs-Hoveyda system ([RuCl2(IMesH2)(CH-2-(2-PrO-C6H4)]) (1) and the dicationic ruthenium alkylidene [Ru(DMF)3(IMesH2)(CH-2-(2-PrO-C6H4)] (2, IMesH2 = 1,3-dimesitylimidazolin-2-ylidene) is reported. Biphasic conditions using 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([BDMIM(+)BF4(-)]) and 1,2,4-trichlorobenzene (TCB) are applied. Under the chosen conditions (T = 75 °C, 20 mbar), the use of catalyst 1 results only in the formation of low-molecular-weight polymers (Mn ≤ 10,000 g mol(-1)), while catalyst 2 allows for the high yield synthesis of high-molecular-weight polymers (Mn ≤ 40,000 g mol(-1), yields ≤ 99%). Irrespective of the catalyst used, all polymers display a high trans-content (>95%). Notably, Ru-contamination of the target polymers without any additional purification is as low as 1.2 ppm with catalyst 2. Together with the high yields and high molecular weights, the low Ru-contaminations clearly illustrate the advantages of the biphasic setup.

  2. Impact of assembly, testing and launch operations on the airborne bacterial diversity within a spacecraft assembly facility clean-room

    NASA Astrophysics Data System (ADS)

    Newcombe, David A.; La Duc, Myron T.; Vaishampayan, Parag; Venkateswaran, Kasthuri

    2008-10-01

    In an effort to minimize the probability of forward contamination of pristine extraterrestrial environments, the National Aeronautics and Space Administration requires that all US robotic spacecraft undergo assembly, testing and launch operations (ATLO) in controlled clean-room environments. This study examines the impact of ATLO activity on the microbial diversity and overall bioburden contained within the air of the clean-room facility in which the Mars Exploration Rovers (MERs) underwent final preparations for launch. Air samples were collected from several facility locations and traditional culture-based and molecular methodologies were used to measure microbial burden and diversity. Surprisingly, the greatest estimates of airborne bioburden, as derived from ATP content and cultivation assays, were observed prior to the commencement of MER ATLO activities. Furthermore, airborne microbial diversity gradually declined from the initiation of ATLO on through to launch. Proteobacterial sequences were common in 16S rDNA clone libraries. Conspicuously absent were members of the Firmicutes phylum, which includes the genus Bacillus. In previous studies, species of this genus were repeatedly isolated from the surfaces of spacecraft and clean-room assembly facilities. Increased cleaning and maintenance initiated immediately prior to the start of ATLO activity could explain the observed declines in both airborne bioburden and microbial diversity.

  3. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

    Mogi, Toru; Ito, Hisatoshi; Kaieda, Hideshi; Kusunoki, Kenichiro; Saltus, Richard W.; Fitterman, David V.; Okuma, Shigeo; Nakatsuka, Tadashi

    2006-05-01

    Airborne geophysics can be defined as the measurement of Earth properties from sensors in the sky. The airborne measurement platform is usually a traditional fixed-wing airplane or helicopter, but could also include lighter-than-air craft, unmanned drones, or other specialty craft. The earliest history of airborne geophysics includes kite and hot-air balloon experiments. However, modern airborne geophysics dates from the mid-1940s when military submarine-hunting magnetometers were first used to map variations in the Earth's magnetic field. The current gamut of airborne geophysical techniques spans a broad range, including potential fields (both gravity and magnetics), electromagnetics (EM), radiometrics, spectral imaging, and thermal imaging.

  4. Airborne Remote Sensing

    NASA Technical Reports Server (NTRS)

    1992-01-01

    NASA imaging technology has provided the basis for a commercial agricultural reconnaissance service. AG-RECON furnishes information from airborne sensors, aerial photographs and satellite and ground databases to farmers, foresters, geologists, etc. This service produces color "maps" of Earth conditions, which enable clients to detect crop color changes or temperature changes that may indicate fire damage or pest stress problems.

  5. Airborne asbestos in buildings.

    PubMed

    Lee, R J; Van Orden, D R

    2008-03-01

    The concentration of airborne asbestos in buildings nationwide is reported in this study. A total of 3978 indoor samples from 752 buildings, representing nearly 32 man-years of sampling, have been analyzed by transmission electron microscopy. The buildings that were surveyed were the subject of litigation related to suits alleging the general building occupants were exposed to a potential health hazard as a result the presence of asbestos-containing materials (ACM). The average concentration of all airborne asbestos structures was 0.01structures/ml (s/ml) and the average concentration of airborne asbestos > or = 5microm long was 0.00012fibers/ml (f/ml). For all samples, 99.9% of the samples were <0.01 f/ml for fibers longer than 5microm; no building averaged above 0.004f/ml for fibers longer than 5microm. No asbestos was detected in 27% of the buildings and in 90% of the buildings no asbestos was detected that would have been seen optically (> or = 5microm long and > or = 0.25microm wide). Background outdoor concentrations have been reported at 0.0003f/ml > or = 5microm. These results indicate that in-place ACM does not result in elevated airborne asbestos in building atmospheres approaching regulatory levels and that it does not result in a significantly increased risk to building occupants.

  6. Airborne exposure patterns from a passenger source in aircraft cabins.

    PubMed

    Bennett, James S; Jones, Byron W; Hosni, Mohammad H; Zhang, Yuanhui; Topmiller, Jennifer L; Dietrich, Watts L

    2013-01-01

    Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins.

  7. Airborne exposure patterns from a passenger source in aircraft cabins

    PubMed Central

    Bennett, James S.; Jones, Byron W.; Hosni, Mohammad H.; Zhang, Yuanhui; Topmiller, Jennifer L.; Dietrich, Watts L.

    2015-01-01

    Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins. PMID:26526769

  8. Photoreactivation in Airborne Mycobacterium parafortuitum

    PubMed Central

    Peccia, Jordan; Hernandez, Mark

    2001-01-01

    Photoreactivation was observed in airborne Mycobacterium parafortuitum exposed concurrently to UV radiation (254 nm) and visible light. Photoreactivation rates of airborne cells increased with increasing relative humidity (RH) and decreased with increasing UV dose. Under a constant UV dose with visible light absent, the UV inactivation rate of airborne M. parafortuitum cells decreased by a factor of 4 as RH increased from 40 to 95%; however, under identical conditions with visible light present, the UV inactivation rate of airborne cells decreased only by a factor of 2. When irradiated in the absence of visible light, cellular cyclobutane thymine dimer content of UV-irradiated airborne M. parafortuitum and Serratia marcescens increased in response to RH increases. Results suggest that, unlike in waterborne bacteria, cyclobutane thymine dimers are not the most significant form of UV-induced DNA damage incurred by airborne bacteria and that the distribution of DNA photoproducts incorporated into UV-irradiated airborne cells is a function of RH. PMID:11526027

  9. MOLECULAR EVALUATION OF CHANGES IN PLANKTONIC BACTERIAL POPULATION RESULTING FROM EQUINE FECAL CONTAMINATION IN A SUB-WATERSHED

    EPA Science Inventory

    Contamination of watersheds by fecal bacteria is a frequent cause for surface waters to be placed on the national impaired waters list. However, since the presence of fecal bacteria does not always indicate human fecal input, it is necessary to distinguish between fecal sources. ...

  10. A Molecular-Based Approach for Examining Responses of Eukaryotes in Microcosms to Contaminant-Spiked Estuarine Sediments

    EPA Science Inventory

    Ecotoxicological information for most contaminants is limited to a small number of taxa, and these are generally restricted to comparatively hardy organisms that are readily extractable from test media and easily identifiable. Advances in DNA sequencing can now provide a comprehe...

  11. Molecular composition and size distribution of sugars, sugar-alcohols and carboxylic acids in airborne particles during a severe urban haze event caused by wheat straw burning

    NASA Astrophysics Data System (ADS)

    Wang, Gehui; Chen, Chunlei; Li, Jianjun; Zhou, Bianhong; Xie, Mingjie; Hu, Shuyuan; Kawamura, Kimitaka; Chen, Yan

    2011-05-01

    Molecular compositions and size distributions of water-soluble organic compounds (WSOC, i.e., sugars, sugar-alcohols and carboxylic acids) in particles from urban air of Nanjing, China during a severe haze event caused by field burning of wheat straw were characterized and compared with those in the summer and autumn non-haze periods. During the haze event levoglucosan (4030 ng m -3) was the most abundant compound among the measured WSOC, followed by succinic acid, malic acid, glycerol, arabitol and glucose, being different from those in the non-haze samples, in which sucrose or azelaic acid showed a second highest concentration, although levoglucosan was the highest. The measured WSOC in the haze event were 2-20 times more than those in the non-hazy days. Size distribution results showed that there was no significant change in the compound peaks in coarse mode (>2.1 μm) with respect to the haze and non-haze samples, but a large difference in the fine fraction (<2.1 μm) was found with a sharp increase during the hazy days mostly due to the increased emissions of wheat straw burning. Molecular compositions of organic compounds in the fresh smoke particles from wheat straw burning demonstrate that sharply increased concentrations of glycerol and succinic and malic acids in the fine particles during the haze event were mainly derived from the field burning of wheat straw, although the sources of glucose and related sugar-alcohols whose concentrations significantly increased in the fine haze samples are unclear. Compared to that in the fresh smoke particles of wheat straw burning an increase in relative abundance of succinic acid to levoglucosan during the haze event suggests a significant production of secondary organic aerosols during transport of the smoke plumes.

  12. Methods for Sampling of Airborne Viruses

    PubMed Central

    Verreault, Daniel; Moineau, Sylvain; Duchaine, Caroline

    2008-01-01

    Summary: To better understand the underlying mechanisms of aerovirology, accurate sampling of airborne viruses is fundamental. The sampling instruments commonly used in aerobiology have also been used to recover viruses suspended in the air. We reviewed over 100 papers to evaluate the methods currently used for viral aerosol sampling. Differentiating infections caused by direct contact from those caused by airborne dissemination can be a very demanding task given the wide variety of sources of viral aerosols. While epidemiological data can help to determine the source of the contamination, direct data obtained from air samples can provide very useful information for risk assessment purposes. Many types of samplers have been used over the years, including liquid impingers, solid impactors, filters, electrostatic precipitators, and many others. The efficiencies of these samplers depend on a variety of environmental and methodological factors that can affect the integrity of the virus structure. The aerodynamic size distribution of the aerosol also has a direct effect on sampler efficiency. Viral aerosols can be studied under controlled laboratory conditions, using biological or nonbiological tracers and surrogate viruses, which are also discussed in this review. Lastly, general recommendations are made regarding future studies on the sampling of airborne viruses. PMID:18772283

  13. Application of molecularly imprinted and non-imprinted polymers for removal of emerging contaminants in water and wastewater treatment: a review.

    PubMed

    Murray, Audrey; Ormeci, Banu

    2012-11-01

    Over the past decade, several studies have reported trace levels of endocrine disrupting compounds, pharmaceuticals, and personal care products in surface waters, drinking water, and wastewater effluents. There has also been an increased concern about the ecological and human health impact of these contaminants, and their removal from water and wastewater has become a priority. Traditional treatment processes are limited in their ability to remove emerging contaminants from water, and there is a need for new technologies that are effective and feasible. This paper presents a review on recent research results on molecularly imprinted (MIP) and non-imprinted (NIP) polymers and evaluates their potential as a treatment method for the removal of emerging contaminants from water and wastewater. It also discusses the relative benefits and limitations of using MIP or NIP for water and wastewater treatment. MIP, and in particular NIP, offer promising applications for wastewater treatment, but their toxicity and possible health effects should be carefully studied before they are considered for drinking water treatment. More research is also required to determine how best to incorporate MIP and NIP in treatment plants.

  14. A SURVEY OF INDOOR AIR CONTAMINATES USING SEMIPERMEABLE MEMBRANE DEVICES

    EPA Science Inventory

    Semipermeable membrane devices (SPMDs) were deployed in indoor areas in approximately 50 residences along the border between Arizona and Mexico to measure airborne contaminants. The results of the primary analyses and gas chromatographic/mass spectrometric confirmation for org...

  15. Theoretical study on the effect of the design of small (milli-Newton) thruster jets on molecular contamination for the space station

    NASA Technical Reports Server (NTRS)

    Riley, B. R.

    1986-01-01

    The self-induced molecular contamination around the space station could have adverse effects on space station components (for example solar panels) as well as scientific experiments that might be done on or near the space station. Aerospace engineers need to design a space station (SS) propulsion system that keeps the SS in a stable orbit and at the same time does not allow the propellant gases to interfere with the experiments of the user. One scenario that might accomplish the above requirements is to use an electrothermal propulsion system, resistojet, that will thrust continuously in the hundreds of milli-Newton range which will provide a constant altitude for the SS with a low g environment. As a first attempt to understand the contamination from such a propulsion system, a point source model was developed. The numerical results of the point source model are given. Number column densities for CO2 are presented as a function of direction of observation (line of sight), temperature of the exit gas, and mean exit velocity. All the results are for a constant exhaust rate of 5,000 kg/year. In addition, a mathematical model to study the effect of nozzle design on the induced molecular environment around the space station produced by simple gas propellants is described. The mathematical model would allow one to follow the expansion of the gas from the throat of a nozzle to the nozzle exit plane and then into the space external to the nozzle.

  16. [Inhibition of Low Molecular Organic Acids on the Activity of Acidithiobacillus Species and Its Effect on the Removal of Heavy Metals from Contaminated Soil].

    PubMed

    Song, Yong-wei; Wang, He-rul; Cao, Yan-xiao; Li, Fei; Cui, Chun-hong; Zhou, Li

    2016-05-15

    Application of organic fertilizer can reduce the solubility and bioavailability of heavy metals in contaminated soil, but in the flooded anaerobic environment, organic fertilizer will be decomposed to produce a large number of low molecular organic acids, which can inhibit the biological activity of Acidithiobacillus species. Batch cultures studies showed that the monocarboxylic organic acids including formic acid, acetic acid, propionic acid, and butyric acid exhibited a marked toxicity to Acidithiobacillus species, as indicated by that 90% of inhibitory rate for Fe2 and So oxidation in 72 h were achieved at extremely low concentrations of 41.2 mg · L⁻¹, 78.3 mg · L⁻¹, 43.2 mg · L⁻¹, 123.4 mg · L⁻¹ and 81.9 mg 230. 4 mg · L⁻¹, 170.1 mg · L⁻¹, 123.4 mg · L⁻¹ respectively. Of these organic acids, formic acid was the most toxic one as indicated by that Fe2 and So oxidation was almost entirely inhibited at a low concentration. In addition, it was found that Acidithiobacillus ferrooxidans was more sensitive to low molecular organic acids than Acidithiobacillus thiooxidans. What's more, there was little effect on biological acidification process of heavy metal contaminated soil when organic acids were added at initial stage (Oh), but it was completely inhibited when these acids were added after 12 h of conventional biological acidification, thus decreasing the efficiency of heavy metals dissolution from soil.

  17. Absolute airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Baumann, Henri

    This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem we had to resolve were to reduce the influence of the non-gravitational accelerations included in the measurements. We studied two different approaches to resolve it: direct mechanical filtering, and post-processing digital compensation. The first part of the work describes in detail the different mechanical passive filters of vibrations, which were studied and tested in the laboratory and later in a small truck in movement. For these tests as well as for the airborne measurements an absolute gravimeter FG5-L from Micro-G Ltd was used together with an Inertial navigation system Litton-200, a vertical accelerometer EpiSensor, and GPS receivers for positioning. These tests showed that only the use of an optical table gives acceptable results. However, it is unable to compensate for the effects of the accelerations of the drag free chamber. The second part describes the strategy of the data processing. It is based on modeling the perturbing accelerations by means of GPS, EpiSensor and INS data. In the third part the airborne experiment is described in detail, from the mounting in the aircraft and data processing to the different problems encountered during the evaluation of the quality and accuracy of the results. In the part of data processing the different steps conducted from the raw apparent gravity data and the trajectories to the estimation of the true gravity are explained. A comparison between the estimated airborne data and those obtained by ground upward continuation at flight altitude allows to state that airborne absolute gravimetry is feasible and

  18. Facile synthesis of N-F codoped and molecularly imprinted TiO2 for enhancing photocatalytic degradation of target contaminants

    NASA Astrophysics Data System (ADS)

    Wu, Yanyan; Dong, Yuming; Xia, Xiaofeng; Liu, Xiang; Li, Hexing

    2016-02-01

    N-F codoped and molecularly imprinted TiO2 (MIP-NFTs) were successfully prepared by simple ethanol-water solvothermal method using 2-nitrophenol (2NP) and 4-nitrophenol (4NP) as template molecules (target contaminants), respectively. The surface structure and properties of the catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption/desorption measurements (BET), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectra (UV-vis DRS). In comparison with non-imprinted N-F codoped TiO2 nanocomposites (NIP-NFTs), MIP-NFTs show a higher adsorption, good selectivity and preferable degradation capacity toward the target contaminants. The adsorption amounts of 2NP and 4NP over the corresponding MIP-NFTs are about 1.78 and 2.21 times of that over NIP-NFTs, respectively. MIP-NFTs show a much higher adsorption capacity and selectivity for target contaminants in the mixed solution. Degradation selectivity experiments demonstrate that the selectivity coefficient (R) of degradation of 2NP relative to 4NP over 2NP/MIP-NFTs and 4NP relative to 2NP over 4NP/MIP-NFTs are 1.93 and 1.61, respectively. The enhancement about adsorption capacity and selectivity can be attributed to the chemical interaction and size matching between target contaminants and imprinted cavities. The apparent rate constants for the photodegradation of 2NP and 4NP over the corresponding MIP-NFTs are 0.05233 min-1 and 0.03734 min-1, being 267% and 198% of that over NIP-NFTs under simulated solar light. Moreover, MIP-NFTs exhibit excellent reusability due to their inorganic framework.

  19. Molecular characterization of the diversity of Clostridium chauvoei isolates collected from two bovine slaughterhouses: analysis of cross-contamination.

    PubMed

    Sathish, S; Swaminathan, K

    2008-06-01

    Clostridium chauvoei is the etiologic agent of blackleg, a high mortality rate disease affecting mainly cattle and sheep. Carcasses of animals affected by the disease are the chief source of soil infection and considered as an ever-present threat to livestock health. A study was undertaken to examine the cross-contamination of C. chauvoei in two different bovine slaughterhouses using restriction endonuclease analysis (REA) and protein analysis. Samples from various sites of two different bovine slaughterhouses were screened and 34 isolates were identified by conventional techniques and 16S rRNA gene (rrs) sequencing. C. chauvoei were isolated from carcass, soil, and sewage from slaughterhouses examined. The isolates were differentiated using REA and whole-cell and excretory protein pattern analysis combined with numerical analysis and cluster formation. The alpha and beta toxins produced by the strains were characterized. Our preliminary results suggest that REA combined with numerical analysis provides additional criteria and characteristic banding patterns for the study of the cross-contamination and characterization of C. chauvoei. The effects of temperature, oxygen tension, and enzymes on C. chauvoei hemolysin activity were also discussed. These microorganisms may be a potential contaminant of carcasses and widespread in soil of abattoir environments. The information of area-specific distribution of C. chauvoei strains and its toxin characteristics may give an efficient program in protecting cattle and other ruminants.

  20. Contamination control during shipping, handling, and storage of reticles

    NASA Astrophysics Data System (ADS)

    Zhu, Sheng-Bai

    2000-06-01

    This paper discusses state-of-the-art technology for controlling contamination and defects during shipping, handling, or storage of reticles. Reticles are used for printing IC patterns onto semiconductor wafers. In lithography process, defects in images are converted to wafers after each exposure, leading to classic failures such as short circuits or opens. Since a large batch of wafers might be processed before the defects are detected, high quality pattern images are very important for yield enhancement. Pattern defects can be created through particle deposition or damage of chrome lines due to Electrostatic Discharge (ESD) events. Airborne Molecular Contamination (AMC) may cause problems such as T- topping of photoresists or optics hazing which reduces image homogeneity and energy transmission. As the critical dimensions shrink to deep submicron regime, the susceptibility of reticle patterns to contaminant continuously increases. To meet increasingly stringent requirements of patterning technology, Reticle SMIF Pods (RSP) are developed. Reticles are encapsulated in the sealed pod to avoid particulate contamination in storage, as well as in manual or automatic transport. Constructed exclusively with static dissipative materials, the RSP provides effective protection for reticles from ESD-induced damage. Molecular contamination is minimized by carefully selecting construction materials. Equipped with an electronic data tracking/controlling device, the RSP can be integrated into OEM tools for automatic reticle management. With optional purge capability, the reticle environment is protected by chemically clean inert gas, which offers additional contamination control. These technologies are extensively discussed in this paper. Design principles and experimental data that support performance evaluations of RSP are presented.

  1. Airborne Intercept Monitoring

    DTIC Science & Technology

    2006-04-01

    Primary mirror of Zerodur with Pilkington 747 coating • FOV = 0.104 degrees Airborne Intercept Monitoring RTO-MP-SET-105 16 - 3 UNCLASSIFIED...Pointing System (SPS). The STS is a 0.75 meter aperture Mersenne Cassegrain telescope and the SAT is a 0.34 meter aperture 3- mirror anastigmat telescope...UNLIMITED UNCLASSIFIED/UNLIMITED • Air Flow to Mitigate Thermal “Seeing” Effects • Light weighted primary mirror to reduce mass The SAT

  2. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

    The research relating to airborne fire fighting systems is reviewed to provide NASA/Langley Research Center with current information on the use of aircraft in forest fire operations, and to identify research requirements for future operations. A literature survey, interview of forest fire service personnel, analysis and synthesis of data from research reports and independent conclusions, and recommendations for future NASA-LRC programs are included.

  3. Airborne Infrared Astronomical Telescopes

    NASA Astrophysics Data System (ADS)

    Erickson, Edwin F.

    2017-01-01

    A unique program of infrared astronomical observations from aircraft evolved at NASA’s Ames Research Center, beginning in the 1960s. Telescopes were flown on a Convair 990, a Lear Jet, and a Lockheed C-141 - the Kuiper Airborne Observatory (KAO) - leading to the planning and development of SOFIA: a 2.7 m telescope now flying on a Boeing 747SP. The poster describes these telescopes and highlights of some of the scientific results obtained from them.

  4. Airborne wireless communication systems, airborne communication methods, and communication methods

    DOEpatents

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

    An airborne wireless communication system includes circuitry configured to access information describing a configuration of a terrestrial wireless communication base station that has become disabled. The terrestrial base station is configured to implement wireless communication between wireless devices located within a geographical area and a network when the terrestrial base station is not disabled. The circuitry is further configured, based on the information, to configure the airborne station to have the configuration of the terrestrial base station. An airborne communication method includes answering a 911 call from a terrestrial cellular wireless phone using an airborne wireless communication system.

  5. Airborne field strength monitoring

    NASA Astrophysics Data System (ADS)

    Bredemeyer, J.; Kleine-Ostmann, T.; Schrader, T.; Münter, K.; Ritter, J.

    2007-06-01

    In civil and military aviation, ground based navigation aids (NAVAIDS) are still crucial for flight guidance even though the acceptance of satellite based systems (GNSS) increases. Part of the calibration process for NAVAIDS (ILS, DME, VOR) is to perform a flight inspection according to specified methods as stated in a document (DOC8071, 2000) by the International Civil Aviation Organization (ICAO). One major task is to determine the coverage, or, in other words, the true signal-in-space field strength of a ground transmitter. This has always been a challenge to flight inspection up to now, since, especially in the L-band (DME, 1GHz), the antenna installed performance was known with an uncertainty of 10 dB or even more. In order to meet ICAO's required accuracy of ±3 dB it is necessary to have a precise 3-D antenna factor of the receiving antenna operating on the airborne platform including all losses and impedance mismatching. Introducing precise, effective antenna factors to flight inspection to achieve the required accuracy is new and not published in relevant papers yet. The authors try to establish a new balanced procedure between simulation and validation by airborne and ground measurements. This involves the interpretation of measured scattering parameters gained both on the ground and airborne in comparison with numerical results obtained by the multilevel fast multipole algorithm (MLFMA) accelerated method of moments (MoM) using a complex geometric model of the aircraft. First results will be presented in this paper.

  6. Airborne Submillimeter Spectroscopy

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    1998-01-01

    This is the final technical report for NASA-Ames grant NAG2-1068 to Caltech, entitled "Airborne Submillimeter Spectroscopy", which extended over the period May 1, 1996 through January 31, 1998. The grant was funded by the NASA airborne astronomy program, during a period of time after the Kuiper Airborne Observatory was no longer operational. Instead. this funding program was intended to help develop instrument concepts and technology for the upcoming SOFIA (Stratospheric Observatory for Infrared Astronomy) project. SOFIA, which is funded by NASA and is now being carried out by a consortium lead by USRA (Universities Space Research Association), will be a 747 aircraft carrying a 2.5 meter diameter telescope. The purpose of our grant was to fund the ongoing development of sensitive heterodyne receivers for the submillimeter band (500-1200 GHz), using sensitive superconducting (SIS) detectors. In 1997 July we submitted a proposal to USRA to construct a heterodyne instrument for SOFIA. Our proposal was successful [1], and we are now continuing our airborne astronomy effort with funding from USRA. A secondary purpose of the NAG2-1068 grant was to continue the anaIN'sis of astronomical data collected with an earlier instrument which was flown on the NASA Kuiper Airborne Observatory (KAO). The KAO instrument and the astronomical studies which were carried out with it were supported primarily under another grant, NAG2-744, which extended over October 1, 1991 through Januarv 31, 1997. For a complete description of the astronomical data and its anailysis, we refer the reader to the final technical report for NAG2-744, which was submitted to NASA on December 1. 1997. Here we report on the SIS detector development effort for SOFIA carried out under NAG2-1068. The main result of this effort has been the demonstration of SIS mixers using a new superconducting material niobium titanium nitride (NbTiN), which promises to deliver dramatic improvements in sensitivity in the 700

  7. Molecular characterization of conjugative plasmids in pesticide tolerant and multi-resistant bacterial isolates from contaminated alluvial soil.

    PubMed

    Anjum, Reshma; Grohmann, Elisabeth; Malik, Abdul

    2011-06-01

    A total of 35 bacteria from contaminated soil (cultivated fields) near pesticide industry from Chinhat, Lucknow, (India) were isolated and tested for their tolerance/resistance to pesticides, heavy metals and antibiotics. Bacterial isolates were identified by 16S rDNA sequencing. Gas Chromatography analysis of the soil samples revealed the presence of lindane at a concentration of 547 ng g(-1) and α-endosulfan and β-endosulfan of 422 ng g(-1) and 421 ng g(-1) respectively. Atomic Absorption Spectrophotometry analysis of the test sample was done and Cr, Zn, Ni, Fe, Cu and Cd were detected at concentrations of 36.2, 42.5, 43.2, 241, 13.3 and 11.20 mg kg(-1) respectively. Minimum inhibitory concentrations of all the isolates were determined for pesticides and heavy metals. All the multi-resistant/tolerant bacterial isolates were also tested for the presence of incompatibility (Inc) group IncP, IncN, IncW, IncQ plasmids and for rolling circle plasmids of the pMV158-family by PCR. Total community DNA was extracted from pesticide contaminated soil. PCR amplification of the bacterial isolates and soil DNA revealed the presence of IncP-specific sequences (trfA2 and oriT) which was confirmed by dot blot hybridization with RP4-derived DIG-labelled probes. Plasmids belonging to IncN, IncW and IncQ group were neither detected in the bacterial isolates nor in total soil DNA. The presence of conjugative or mobilizable IncP plasmids in the isolates indicate that these bacteria have gene transfer capacity with implications for dissemination of heavy metal and antibiotic resistance genes. We propose that IncP plasmids are mainly responsible for the spread of multi-resistant bacteria in the contaminated soils.

  8. Molecular detection of marine bacterial populations on beaches contaminated by the Nakhodka tanker oil-spill accident.

    PubMed

    Kasai, Y; Kishira, H; Syutsubo, K; Harayama, S

    2001-04-01

    In January 1997, the tanker Nakhodka sank in the Japan Sea, and more than 5000 tons of heavy oil leaked. The released oil contaminated more than 500 km of the coastline, and some still remained even by June 1999. To investigate the long-term influence of the Nakhodka oil spill on marine bacterial populations, sea water and residual oil were sampled from the oil-contaminated zones 10, 18, 22 and 29 months after the accident, and the bacterial populations in these samples were analysed by denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rDNA fragments. The dominant DGGE bands were sequenced, and the sequences were compared with those in DNA sequence libraries. Most of the bacteria in the sea water samples were classified as the Cytophaga-Flavobacterium-Bacteroides phylum, alpha-Proteobacteria or cyanobacteria. The bacteria detected in the oil paste samples were different from those detected in the sea water samples; they were types related to hydrocarbon degraders, exemplified by strains closely related to Sphingomonas subarctica and Alcanivorax borkumensis. The sizes of the major bacterial populations in the oil paste samples ranged from 3.4 x 10(5) to 1.6 x 10(6) bacteria per gram of oil paste, these low numbers explaining the slow rate of natural attenuation.

  9. Molecular identification of isolated fungi, microbial and heavy metal contamination of canned meat products sold in Riyadh, Saudi Arabia

    PubMed Central

    Nasser, Laila A.

    2014-01-01

    Several studies have shown that canned meat products may be contaminated with fungal elements, bacteria and even heavy metals which may occur during the transportation, storage and handling processes. We conducted this study to determine the fungal, microbial and heavy metal contents of canned meats in Saudi Arabia. Of the 13 canned meat samples studied, Aspergillus and Penicillium were found in more than 70% of the total samples. Sequences of Penicillium species isolated from meat samples generated a phylogenetic tree which shows that the studied isolates were clustered in four groups. No bacterial contamination was noted in all of the samples. Nine of the 13 samples had iron concentrations above the permissible limit. All samples had zinc and copper levels below the maximum permissible limit. Four samples had cadmium levels above the maximum permissible level. All samples had levels of lead above the maximum permissible levels. These results indicate that fungal elements and higher levels of heavy metals such as lead and cadmium can be found in canned meat products. This may pose as a real danger to consumers, since canned meat products are readily accessible and convenient in Saudi Arabia. PMID:26288552

  10. Molecular characterization of bacterial populations in petroleum-contaminated groundwater discharged from underground crude oil storage cavities.

    PubMed

    Watanabe, K; Watanabe, K; Kodama, Y; Syutsubo, K; Harayama, S

    2000-11-01

    Petroleum-contaminated groundwater discharged from underground crude oil storage cavities (cavity groundwater) harbored more than 10(6) microorganisms ml(-1), a density 100 times higher than the densities in groundwater around the cavities (control groundwater). To characterize bacterial populations growing in the cavity groundwater, 46 PCR-amplified almost full-length 16S ribosomal DNA (rDNA) fragments were cloned and sequenced, and 28 different sequences were obtained. All of the sequences were affiliated with the Proteobacteria; 25 sequences (43 clones) were affiliated with the epsilon subclass, 2 were affiliated with the beta subclass, and 1 was affiliated with the delta subclass. Two major clusters (designated clusters 1 and 2) were found for the epsilon subclass proteobacterial clones; cluster 1 (25 clones) was most closely related to Thiomicrospira denitrificans (88% identical in nucleotide sequence), while cluster 2 (11 clones) was closely related to Arcobacter spp. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified partial 16S rDNA fragments showed that one band was detected most strongly in cavity groundwater profiles independent of storage oil type and season. The sequence of this major band was identical to the sequences of most of the cluster 1 clones. Fluorescence in situ hybridization (FISH) indicated that the cluster 1 population accounted for 12 to 24% of the total bacterial population. This phylotype was not detected in the control groundwater by DGGE and FISH analyses. These results indicate that the novel members of the epsilon subclass of the Proteobacteria grow as major populations in the petroleum-contaminated cavity groundwater.

  11. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

    Bressel, C.; Itzkan, I.; Nunes, J. E.; Hoge, F.

    1977-01-01

    The Airborne Oceanographic Lidar (AOL), a spatially scanning range-gated device installed on board a NASA C-54 aircraft, is described. The AOL system is capable of measuring topographical relief or water depth (bathymetry) with a range resolution of plus or minus 0.3 m in the vertical dimension. The system may also be used to measure fluorescent spectral signatures from 3500 to 8000 A with a resolution of 100 A. Potential applications of the AOL, including sea state measurements, water transparency assessments, oil spill identification, effluent identification and crop cover assessment are also mentioned.

  12. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

    Food allergy to peanut is a significant health problem, and there are reported allergic reactions to peanuts despite not eating or having physical contact with peanuts. It is presumed that an allergic reaction may have occurred from inhalation of airborne peanut allergens. The purpose of this study was to detect the possible concentrations of airborne peanut proteins for various preparations and during specific activities. Separate Ara h 1 and Ara h 2 monoclonal enzyme-linked immunosorbent assays and a polyclonal sandwich enzyme immunoassay for peanuts were used to detect the amount of airborne peanut protein collected using a Spincon Omni 3000 air collector (Sceptor Industries, Inc., Kansas City, MO) under different peanut preparation methods and situations. Air samples were measured for multiple peanut preparations and scenarios. Detectable amounts of airborne peanut protein were measured using a whole peanut immunoassay when removing the shells of roasted peanut. No airborne peanut allergen (Ara h 1 or Ara h 2) or whole peanut protein above the LLD was measured in any of the other peanut preparation collections. Ara h 1, Ara h 2, and polyclonal peanut proteins were detected from water used to boil peanuts. Small amounts of airborne peanut protein were detected in the scenario of removing shells from roasted peanuts; however, Ara h 1 and Ara h 2 proteins were unable to be consistently detected. Although airborne peanut proteins were detected, the concentration of airborne peanut protein that is necessary to elicit a clinical allergic reaction is unknown.

  13. Abundance and diversity of n-alkane-degrading bacteria in a forest soil co-contaminated with hydrocarbons and metals: a molecular study on alkB homologous genes.

    PubMed

    Pérez-de-Mora, Alfredo; Engel, Marion; Schloter, Michael

    2011-11-01

    Unraveling functional genes related to biodegradation of organic compounds has profoundly improved our understanding of biological remediation processes, yet the ecology of such genes is only poorly understood. We used a culture-independent approach to assess the abundance and diversity of bacteria catalyzing the degradation of n-alkanes with a chain length between C(5) and C(16) at a forest site co-contaminated with mineral oil hydrocarbons and metals for nearly 60 years. The alkB gene coding for a rubredoxin-dependent alkane monooxygenase enzyme involved in the initial activation step of aerobic aliphatic hydrocarbon metabolism was used as biomarker. Within the area of study, four different zones were evaluated: one highly contaminated, two intermediately contaminated, and a noncontaminated zone. Contaminant concentrations, hydrocarbon profiles, and soil microbial respiration and biomass were studied. Abundance of n-alkane-degrading bacteria was quantified via real-time PCR of alkB, whereas genetic diversity was examined using molecular fingerprints (T-RFLP) and clone libraries. Along the contamination plume, hydrocarbon profiles and increased respiration rates suggested on-going natural attenuation at the site. Gene copy numbers of alkB were similar in contaminated and control areas. However, T-RFLP-based fingerprints suggested lower diversity and evenness of the n-alkane-degrading bacterial community in the highly contaminated zone compared to the other areas; both diversity and evenness were negatively correlated with metal and hydrocarbon concentrations. Phylogenetic analysis of alkB denoted a shift of the hydrocarbon-degrading bacterial community from Gram-positive bacteria in the control zone (most similar to Mycobacterium and Nocardia types) to Gram-negative genotypes in the contaminated zones (Acinetobacter and alkB sequences with little similarity to those of known bacteria). Our results underscore a qualitative rather than a quantitative response of

  14. Molecular and Stable Isotope Investigation of Nitrite Respiring Bacterial Communities Capable of Anaerobic Ammonium Oxidation (ANAMMOX) and Denitrifying Anaerobic Methane Oxidation (DAMO) in Nitrogen Contaminated Groundwater

    NASA Astrophysics Data System (ADS)

    Song, B.; Hirsch, M.; Taylor, J.; Smith, R. L.; Repert, D.; Tobias, C. R.

    2010-12-01

    Anaerobic ammonium oxidation (ANAMMOX) and denitrifying anaerobic methane oxidation (DAMO) are two recently discovered N2 production pathways in the microbial nitrogen cycle. ANAMMOX has been relatively well investigated in various aquatic ecosystems, while DAMO has been examined only in freshwater wetlands. However, neither ANAMMOX nor DAMO have been studied in groundwater ecosystems as microbial N removal processes where they could compliment or compete with denitrification to remediate N contaminated aquifers. Thus, we conducted molecular and stable isotope analyses to detect and measure ANAMMOX and DAMO in a nitrogen contaminated aquifer on Cape Cod, Massachusetts. The study site has a plume of nitrogen contaminated groundwater as a result of continuous discharge of treated wastewater over 60 years. Groundwater was collected from multiport sampling devices installed at two sites, near the waste-water disposal location (A) and more than 3 km down gradient (B) along the contamination plume. Biomass was collected from water samples for DNA extraction and 15N tracer incubation experiments. PCR with specific 16S rRNA gene primers detected the presence of ANAMMOX and DAMO bacteria at both sites. Phylogenetic analysis of 16S rRNA genes revealed that the ANAMMOX community at site A was most associated with Kuenenia spp. while site B had a community more closely related to Brocadia spp. The DAMO communities at the two sites were quite different based on 16S rRNA gene analysis. The communities at site B are closely associated with Candidatus “Methylomirabilis oxyfera”, which is the first enriched DAMO culture. Most of the 16S rRNA sequences detected in site A were related to those found in other DAMO enrichment cultures established from a eutrophic ditch sediment. In order to determine active members of ANAMMOX communities, the transcriptional expression of hydrazine oxidase (hzo) and hydrazine hydrolase (hh) genes was examined at both sites. In addition, 15N tracer

  15. The New Airborne Disease

    PubMed Central

    Goldsmith, John R.

    1970-01-01

    Community air pollution is the new airborne disease of our generation's communities. It is caused by the increasing use of fuel, associated with both affluence and careless waste. Photochemical air pollution of the California type involves newly defined atmospheric reactions, is due mostly to motor vehicle exhaust, is oxidizing, and produces ozone, plant damage, impairment of visibility and eye and respiratory symptoms. Aggravation of asthma, impairment of lung function among persons with chronic respiratory disease and a possible causal role, along with cigarette smoking in emphysema and chronic bronchitis, are some of the effects of photochemical pollution. More subtle effects of pollution include impairment of oxygen transport by the blood due to carbon monoxide and interference with porphyrin metabolism due to lead. Carbon monoxide exposures may affect survival of patients who are in hospitals because of myocardial infarction. While many uncertainties in pollution-health reactions need to be resolved, a large number of people in California have health impairment due to airborne disease of this new type. PMID:5485227

  16. Molecular characterization of antibiotic-resistant bacteria in contaminated chicken meat sold at supermarkets in Bangkok, Thailand.

    PubMed

    Chaisatit, Chaiyaporn; Tribuddharat, Chanwit; Pulsrikarn, Chaiwat; Dejsirilert, Surang

    2012-01-01

    We assessed contamination by antibiotic-resistant bacteria in chicken meat obtained from supermarkets in Bangkok, Thailand. The prevalence of Salmonella enterica and Escherichia coli was 18.7% (14/75) and 53% (106/200), respectively. Most probable number (MPN) analysis showed that 56.7% of the samples (34/60) were in violation of the limit of allowable coliform bacteria in chicken meat, for which the maximum is 46,000 MPN/g. Multidrug-resistant phenotypes of both S. enterica and E. coli were found. The presence of class 1 integrons was demonstrated by polymerase chain reaction (PCR) and dot-blot hybridization. PCR showed that class 1 integrons were present in 42.9% (6/14) and 37.7% (40/106) of S. enterica and E. coli isolates, respectively. Resistance genes identified in this study were aadA2, aadA4, aadA22, and aadA23 (for aminoglycoside resistance); dfrA5 (for trimethoprim resistance), and lnuF (for lincosamide resistance). Four S. enterica isolates underwent multilocus sequence typing and the results were sequence type (ST) 50, ST 96, ST 1543, and ST 1549, which matched well with strains from many countries and reflected an international spread. Our study revealed that class 1 integrons have spread into community sources and might play an important role in horizontal antibiotic resistance gene transfer.

  17. Processor architecture for airborne SAR systems

    NASA Technical Reports Server (NTRS)

    Glass, C. M.

    1983-01-01

    Digital processors for spaceborne imaging radars and application of the technology developed for airborne SAR systems are considered. Transferring algorithms and implementation techniques from airborne to spaceborne SAR processors offers obvious advantages. The following topics are discussed: (1) a quantification of the differences in processing algorithms for airborne and spaceborne SARs; and (2) an overview of three processors for airborne SAR systems.

  18. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

    Hildebrand, P. H.; Mueller, C. K.

    1984-01-01

    This paper will discuss the capabilities of airborne Doppler radar for atmospheric sciences research. The evaluation is based on airborne and ground based Doppler radar observations of convective storms. The capability of airborne Doppler radar to measure horizontal and vertical air motions is evaluated. Airborne Doppler radar is shown to be a viable tool for atmospheric sciences research.

  19. Molecular Gene Profiling of Clostridium botulinum Group III and Its Detection in Naturally Contaminated Samples Originating from Various European Countries

    PubMed Central

    Woudstra, Cedric; Le Maréchal, Caroline; Souillard, Rozenn; Bayon-Auboyer, Marie-Hélène; Anniballi, Fabrizio; Auricchio, Bruna; De Medici, Dario; Bano, Luca; Koene, Miriam; Sansonetti, Marie-Hélène; Desoutter, Denise; Hansbauer, Eva-Maria; Dorner, Martin B.; Dorner, Brigitte G.

    2015-01-01

    We report the development of real-time PCR assays for genotyping Clostridium botulinum group III targeting the newly defined C. novyi sensu lato group; the nontoxic nonhemagglutinin (NTNH)-encoding gene ntnh; the botulinum neurotoxin (BoNT)-encoding genes bont/C, bont/C/D, bont/D, and bont/D/C; and the flagellin (fliC) gene. The genetic diversity of fliC among C. botulinum group III strains resulted in the definition of five major subgroups named fliC-I to fliC-V. Investigation of fliC subtypes in 560 samples, with various European origins, showed that fliC-I was predominant and found exclusively in samples contaminated by C. botulinum type C/D, fliC-II was rarely detected, no sample was recorded as fliC-III or fliC-V, and only C. botulinum type D/C samples tested positive for fliC-IV. The lack of genetic diversity of the flagellin gene of C. botulinum type C/D would support a clonal spread of type C/D strains in different geographical areas. fliC-I to fliC-III are genetically related (87% to 92% sequence identity), whereas fliC-IV from C. botulinum type D/C is more genetically distant from the other fliC types (with only 50% sequence identity). These findings suggest fliC-I to fliC-III have evolved in a common environment and support a different genetic evolution for fliC-IV. A combination of the C. novyi sensu lato, ntnh, bont, and fliC PCR assays developed in this study allowed better characterization of C. botulinum group III and showed the group to be less genetically diverse than C. botulinum groups I and II, supporting a slow genetic evolution of the strains belonging to C. botulinum group III. PMID:25636839

  20. Molecular gene profiling of Clostridium botulinum group III and its detection in naturally contaminated samples originating from various European countries.

    PubMed

    Woudstra, Cedric; Le Maréchal, Caroline; Souillard, Rozenn; Bayon-Auboyer, Marie-Hélène; Anniballi, Fabrizio; Auricchio, Bruna; De Medici, Dario; Bano, Luca; Koene, Miriam; Sansonetti, Marie-Hélène; Desoutter, Denise; Hansbauer, Eva-Maria; Dorner, Martin B; Dorner, Brigitte G; Fach, Patrick

    2015-04-01

    We report the development of real-time PCR assays for genotyping Clostridium botulinum group III targeting the newly defined C. novyi sensu lato group; the nontoxic nonhemagglutinin (NTNH)-encoding gene ntnh; the botulinum neurotoxin (BoNT)-encoding genes bont/C, bont/C/D, bont/D, and bont/D/C; and the flagellin (fliC) gene. The genetic diversity of fliC among C. botulinum group III strains resulted in the definition of five major subgroups named fliC-I to fliC-V. Investigation of fliC subtypes in 560 samples, with various European origins, showed that fliC-I was predominant and found exclusively in samples contaminated by C. botulinum type C/D, fliC-II was rarely detected, no sample was recorded as fliC-III or fliC-V, and only C. botulinum type D/C samples tested positive for fliC-IV. The lack of genetic diversity of the flagellin gene of C. botulinum type C/D would support a clonal spread of type C/D strains in different geographical areas. fliC-I to fliC-III are genetically related (87% to 92% sequence identity), whereas fliC-IV from C. botulinum type D/C is more genetically distant from the other fliC types (with only 50% sequence identity). These findings suggest fliC-I to fliC-III have evolved in a common environment and support a different genetic evolution for fliC-IV. A combination of the C. novyi sensu lato, ntnh, bont, and fliC PCR assays developed in this study allowed better characterization of C. botulinum group III and showed the group to be less genetically diverse than C. botulinum groups I and II, supporting a slow genetic evolution of the strains belonging to C. botulinum group III.

  1. Subsurface Contamination Control

    SciTech Connect

    Y. Yuan

    2001-12-12

    table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.

  2. Subsurface Contamination Control

    SciTech Connect

    Y. Yuan

    2001-11-16

    table of derived LRCL for nuclides of radiological importance; (3) Provides an as low as is reasonably achievable (ALARA) evaluation of the derived LRCL by comparing potential onsite and offsite doses to documented ALARA requirements; (4) Provides a method for estimating potential releases from a defective WP; (5) Provides an evaluation of potential radioactive releases from a defective WP that may become airborne and result in contamination of the subsurface facility; and (6) Provides a preliminary analysis of the detectability of a potential WP leak to support the design of an airborne release monitoring system.

  3. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

    Hardman, Sean; Freeborn, Dana; Crichton, Dan; Law, Emily; Kay-Im, Liz

    2011-01-01

    Airborne Cloud Computing Environment (ACCE) is JPL's internal investment to improve the return on airborne missions. Improve development performance of the data system. Improve return on the captured science data. The investment is to develop a common science data system capability for airborne instruments that encompasses the end-to-end lifecycle covering planning, provisioning of data system capabilities, and support for scientific analysis in order to improve the quality, cost effectiveness, and capabilities to enable new scientific discovery and research in earth observation.

  4. Airborne Wind Turbine

    SciTech Connect

    2010-09-01

    Broad Funding Opportunity Announcement Project: Makani Power is developing an Airborne Wind Turbine (AWT) that eliminates 90% of the mass of a conventional wind turbine and accesses a stronger, more consistent wind at altitudes of near 1,000 feet. At these altitudes, 85% of the country can offer viable wind resources compared to only 15% accessible with current technology. Additionally, the Makani Power wing can be economically deployed in deep offshore waters, opening up a resource which is 4 times greater than the entire U.S. electrical generation capacity. Makani Power has demonstrated the core technology, including autonomous launch, land, and power generation with an 8 meter wingspan, 20 kW prototype. At commercial scale, Makani Power aims to develop a 600 kW, 28 meter wingspan product capable of delivering energy at an unsubsidized cost competitive with coal, the current benchmark for low-cost power.

  5. Screening and degrading characteristics and community structure of a high molecular weight polycyclic aromatic hydrocarbon-degrading bacterial consortium from contaminated soil.

    PubMed

    Sun, Run; Jin, Jinghua; Sun, Guangdong; Liu, Ying; Liu, Zhipei

    2010-01-01

    Inoculation with efficient microbes had been proved to be the most important way for the bioremediation of polluted environments. For the treatment of abandoned site of Beijing Coking Chemical Plant contaminated with high level of high-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), a bacterial consortium capable of degrading HMW-PAHs, designated 1-18-1, was enriched and screened from HMW-PAHs contaminated soil. Its degrading ability was analyzed by high performance liquid chromatography (HPLC), and the community structure was investigated by construction and analyses of the 16S rRNA gene clone libraries (A, B and F) at different transfers. The results indicated that 1-18-1 was able to utilize pyrene, fluoranthene and benzo[a]pyrene as sole carbon and energy source for growth. The degradation rate of pyrene and fluoranthene reached 82.8% and 96.2% after incubation for 8 days at 30 degrees C, respectively; while the degradation rate of benzo[a]pyrene was only 65.1% after incubation for 28 days at 30 degrees C. Totally, 108, 100 and 100 valid clones were randomly selected and sequenced from the libraries A, B, and F. Phylogenetic analyses showed that all the clones could be divided into 5 groups, Bacteroidetes, alpha-Proteobacteria, Actinobacteria, beta-Proteobacteria and gamma-Proteobacteria. Sequence similarity analyses showed total 39 operational taxonomic units (OTUs) in the libraries. The predominant bacterial groups were alpha-Proteobacteria (19 OTUs, 48.7%), gamma-Proteobacteria (9 OTUs, 23.1%) and beta-Proteobacteria (8 OTUs, 20.5%). During the transfer process, the proportions of alpha-Proteobacteria and beta-Proteobacteria increased greatly (from 47% to 93%), while gamma-Proteobacteria decreased from 32% (library A) to 6% (library F); and Bacteroidetes group disappeared in libraries B and F.

  6. UNDERWATER COATINGS FOR CONTAMINATION CONTROL

    SciTech Connect

    Julia L. Tripp; Kip Archibald; Ann Marie Phillips; Joseph Campbell

    2004-02-01

    The Idaho National Laboratory (INL) deactivated several aging nuclear fuel storage basins. Planners for this effort were greatly concerned that radioactive contamination present on the basin walls could become airborne as the sides of the basins became exposed during deactivation and allowed to dry after water removal. One way to control this airborne contamination was to fix the contamination in place while the pool walls were still submerged. There are many underwater coatings available on the market for marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives were easily applied and adhered well to the substrates (pool wall materials) found in INL fuel pools. Lab-scale experiments were conducted by applying fourteen different commercial underwater coatings to four substrate materials representative of the storage basin construction materials, and evaluating their performance. The coupons included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The evaluation criteria included ease of application, adherence to the four surfaces of interest, no change on water clarity or chemistry, non-hazardous in final applied form and be proven in underwater applications. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected from the underwater coatings tested for application to all four pools. Divers scrubbed loose contamination off the basin walls and floors using a ship hull scrubber and vacuumed up the sludge. The divers then applied the coating using a special powered roller with two separate heated hoses that allowed the epoxy to mix at the roller surface was used to eliminate pot time concerns. The walls were successfully coated and water was removed from the pools with no detectable airborne contamination releases.

  7. Molecular monitoring of spoilage yeasts during the production of candied fruit nougats to determine food contamination sources.

    PubMed

    Martorell, Patricia; Fernández-Espinar, M Teresa; Querol, Amparo

    2005-06-15

    In the present work, we have analysed the yeast microbiota present in a manufacturing plant of candied fruits and nougats. Four yeasts species (Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Sporobolomyces roseus, and Debaryomyces hansenii) and a filamentous fungi (Nectria mauriiticola) were identified according to restriction analysis of 5.8S-ITS rDNA. These identifications were subsequently confirmed by sequencing the D1/D2 domain of the 26S rRNA gene. Z. rouxii and Z. bailii were isolated at high frequency along the whole manufacturing process. Since food alteration by Z. bailii and Z. rouxii is the cause of important economic losses for the food industry, there is a need for differentiating yeasts at the strain level as an essential part of quality control programs in this industry. For this purpose, we have tested the performance of three molecular techniques (RFLP mtDNA, RAPD-PCR, and microsatellite with (GAC)5 and (GTG)5 primers) to differentiate strains belonging to these two Zygosaccharomyces species. Those techniques with the best discriminatory power were applied to differentiate Zygosaccharomyces species isolates. The results of this analysis indicate that one strain of Z. bailii and two strains of Z. rouxii were involved in the spoilage of candied fruits. Moreover, the Z. bailii strain was also present in the spoiled nougat, hence being responsible of this alteration.

  8. Measurement of airborne particle concentrations near the Sunset Crater volcano, Arizona.

    PubMed

    Benke, Roland R; Hooper, Donald M; Durham, James S; Bannon, Donald R; Compton, Keith L; Necsoiu, Marius; McGinnis, Ronald N

    2009-02-01

    Direct measurements of airborne particle mass concentrations or mass loads are often used to estimate health effects from the inhalation of resuspended contaminated soil. Airborne particle mass concentrations were measured using a personal sampler under a variety of surface-disturbing activities within different depositional environments at both volcanic and nonvolcanic sites near the Sunset Crater volcano in northern Arizona. Focused field investigations were performed at this analog site to improve the understanding of natural and human-induced processes at Yucca Mountain, Nevada. The level of surface-disturbing activity was found to be the most influential factor affecting the measured airborne particle concentrations, which increased over three orders of magnitude relative to ambient conditions. As the surface-disturbing activity level increased, the particle size distribution and the majority of airborne particle mass shifted from particles with aerodynamic diameters less than 10 mum (0.00039 in) to particles with aerodynamic diameters greater than 10 mum (0.00039 in). Under ambient conditions, above average wind speeds tended to increase airborne particle concentrations. In contrast, stronger winds tended to decrease airborne particle concentrations in the breathing zone during light and heavy surface-disturbing conditions. A slight increase in the average airborne particle concentration during ambient conditions was found above older nonvolcanic deposits, which tended to be finer grained than the Sunset Crater tephra deposits. An increased airborne particle concentration was realized when walking on an extremely fine-grained deposit, but the sensitivity of airborne particle concentrations to the resuspendible fraction of near-surface grain mass was not conclusive in the field setting when human activities disturbed the bulk of near-surface material. Although the limited sample size precluded detailed statistical analysis, the differences in airborne particle

  9. Quantitative molecular diagnostic assays of grain washes for Claviceps purpurea are correlated with visual determinations of ergot contamination

    PubMed Central

    Comte, Alexia; Gräfenhan, Tom; Links, Matthew G.; Hemmingsen, Sean M.

    2017-01-01

    We examined the epiphytic microbiome of cereal grain using the universal barcode chaperonin-60 (cpn60). Microbial community profiling of seed washes containing DNA extracts prepared from field-grown cereal grain detected sequences from a fungus identified only to Class Sordariomycetes. To identify the fungal sequence and to improve the reference database, we determined cpn60 sequences from field-collected and reference strains of the ergot fungus, Claviceps purpurea. These data allowed us to identify this fungal sequence as deriving from C. purpurea, and suggested that C. purpurea DNA is readily detectable on agricultural commodities, including those for which ergot was not identified as a grading factor. To get a sense of the prevalence and level of C. purpurea DNA in cereal grains, we developed a quantitative PCR assay based on the fungal internal transcribed spacer (ITS) and applied it to 137 samples from the 2014 crop year. The amount of Claviceps DNA quantified correlated strongly with the proportion of ergot sclerotia identified in each grain lot, although there was evidence that non-target organisms were responsible for some false positives with the ITS-based assay. We therefore developed a cpn60-targeted loop-mediated isothermal amplification assay and applied it to the same grain wash samples. The time to positive displayed a significant, inverse correlation to ergot levels determined by visual ratings. These results indicate that both laboratory-based and field-adaptable molecular diagnostic assays can be used to detect and quantify pathogen load in bulk commodities using cereal grain washes. PMID:28257512

  10. Polymer composite adsorbents using particles of molecularly imprinted polymers or aluminium oxide nanoparticles for treatment of arsenic contaminated waters.

    PubMed

    Önnby, L; Pakade, V; Mattiasson, B; Kirsebom, H

    2012-09-01

    Removal of As(V) by adsorption from water solutions was studied using three different synthetic adsorbents. The adsorbents, (a) aluminium nanoparticles (Alu-NPs, <50 nm) incorporated in amine rich cryogels (Alu-cryo), (b) molecular imprinted polymers (<38 μm) in polyacrylamide cryogels (MIP-cryo) and (c) thiol functionalised cryogels (SH-cryo) were evaluated regarding material characteristics and arsenic removal in batch test and continuous mode. Results revealed that a composite design with particles incorporated in cryogels was a successful means for applying small particles (nano- and micro- scale) in water solutions with maintained adsorption capacity and kinetics. Low capacity was obtained from SH-cryo and this adsorbent was hence excluded from the study. The adsorption capacities for the composites were 20.3 ± 0.8 mg/g adsorbent (Alu-cryo) and 7.9 ± 0.7 mg/g adsorbent (MIP-cryo) respectively. From SEM images it was seen that particles were homogeneously distributed in Alu-cryo and heterogeneously distributed in MIP-cryo. The particle incorporation increased the mechanical stability and the polymer backbones of pure polyacrylamide (MIP-cryo) were of better stability than the amine containing polymer backbone (Alu-cryo). Both composites worked well in the studied pH range of pH 2-8. Adsorption tested in real wastewater spiked with arsenic showed that co-ions (nitrate, sulphate and phosphate) affected arsenic removal for Alu-cryo more than for MIP-cryo. Both composites still adsorbed well in the presence of counter-ions (copper and zinc) present at low concentrations (μg/l). The unchanged and selective adsorption in realistic water observed for MIP-cryo was concluded to be due to a successful imprinting, here controlled using a non-imprinted polymer (NIP). A development of MIP-cryo is needed, considering its low adsorption capacity.

  11. Analysis of Membrane Lipids of Airborne Micro-Organisms

    NASA Technical Reports Server (NTRS)

    MacNaughton, Sarah

    2006-01-01

    A method of characterization of airborne micro-organisms in a given location involves (1) large-volume filtration of air onto glass-fiber filters; (2) accelerated extraction of membrane lipids of the collected micro-organisms by use of pressurized hot liquid; and (3) identification and quantitation of the lipids by use of gas chromatography and mass spectrometry. This method is suitable for use in both outdoor and indoor environments; for example, it can be used to measure airborne microbial contamination in buildings ("sick-building syndrome"). The classical approach to analysis of airborne micro-organisms is based on the growth of cultureable micro-organisms and does not provide an account of viable but noncultureable micro-organisms, which typically amount to more than 90 percent of the micro-organisms present. In contrast, the present method provides an account of all micro-organisms, including cultureable, noncultureable, aerobic, and anaerobic ones. The analysis of lipids according to this method makes it possible to estimate the number of viable airborne micro-organisms present in the sampled air and to obtain a quantitative profile of the general types of micro-organisms present along with some information about their physiological statuses.

  12. Polychlorinated Biphenyl (PCB) carcinogenicity with special emphasis on airborne PCBs

    PubMed Central

    Robertson, Larry W.; Ludewig, Gabriele

    2011-01-01

    Polychlorinated biphenyls (PCBs) are industrial chemicals used in various applications requiring chemical stabilityand have now become widely dispersed. Their characteristics of persistence, low water/higher lipid solubility, contribute to their ability to bioconcentrate and bioaccumulate. Traditionally PCBs have been regulated as food contaminants and the general population is primarily exposed by that route. PCBs in foodstuffs are generally higher chlorinated, resistant to metabolic breakdown, and elicit toxic changes that are thought to be predominantly receptor/parent PCB-driven. But for certain occupational exposures, and for those persons residing or working in contaminated buildings, and in large cities, an inhalation route of exposure may predominate. Airborne PCBs are, in contrast to foodborne PCBs, lower chlorinated, more volatile, and subject to metabolic attack. In this review, we have explored (geno-) toxic manifestations of PCBs typical of those found in air. Here metabolic conversion of the parent PCB to hydroxylated and other metabolic progeny appear to play a dominant role, especially in genotoxicity. We should be cognizant of the impact of exposures to airborne PCBs for those individuals who are occupationally exposed, for persons living near contaminated sites, for those who work or go to school in contaminated buildings, and especially cognizant of the young, the socio-economically disadvantaged and medically-underserved or nutritionally-deficient populations. PMID:21686028

  13. Molecular profiling of microbial communities from contaminated sources: Use of substractive cloning methods and rDNA spacer sequences. 1997 annual progress report

    SciTech Connect

    1997-12-01

    'This project is to develop molecular methods for rapid characterization of microbial communities in contaminated ecosystems. The authors are exploring the use of {sup 16}s ribosomal DNA intergenic spacer regions (ISRs) to profile community composition. The choice proves to be a good one: there are 200--550 bases of 1 to 3 variable regions from which to choose species-specific probes, as well as 2--4 stretches of conserved sequence from which to develop universal PCR (polymerase chain reaction) primers. Preliminary community characterization is complete, and several types of arrays are under development to determine the types of bacteria present and the status of the ground water. Profiling the community composition of polluted groundwater will impact the broad field of microbial ecology as well as mixed-waste bioremediation. Results The samples the authors have been analysing were provided by Dr. Fred Brockman from Pacific Northwest Laboratory, and were collected at the US DOE Hanford site, Washington state. The samples were microbial filtrates from ground water polluted with 2 mg/L carbon tetrachloride and 250 mg/L nitrate and subjected to enrichment (acetate + nitrate) and recirculation. This project is described in some detail in PNNL-11113, Accelerated In Situ Bioremediation of Groundwater, by M.J. Truex, B.S. Hooker, and D.B. Anderson, July 1996.'

  14. International Space Station External Contamination Status

    NASA Technical Reports Server (NTRS)

    Mikatarian, Ron; Soares, Carlos

    2000-01-01

    PResentation slides examine external contamination requirements; International Space Station (ISS) external contamination sources; ISS external contamination sensitive surfaces; external contamination control; external contamination control for pre-launch verification; flight experiments and observations; the Space Shuttle Orbiter waste water dump, materials outgassing, active vacuum vents; example of molecular column density profile, modeling and analysis tools; sources of outgassing induced contamination analyzed to date, quiescent sources, observations on optical degradation due to induced external contamination in LEO; examples of typical contaminant and depth profiles; and status of the ISS system, material outgassing, thruster plumes, and optical degradation.

  15. Airborne rescue system

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1991-01-01

    The airborne rescue system includes a boom with telescoping members for extending a line and collar to a rescue victim. The boom extends beyond the tip of the helicopter rotor so that the victim may avoid the rotor downwash. The rescue line is played out and reeled in by winch. The line is temporarily retained under the boom. When the boom is extended, the rescue line passes through clips. When the victim dons the collar and the tension in the line reaches a predetermined level, the clips open and release the line from the boom. Then the rescue line can form a straight line between the victim and the winch, and the victim can be lifted to the helicopter. A translator is utilized to push out or pull in the telescoping members. The translator comprises a tape and a rope. Inside the telescoping members the tape is curled around the rope and the tape has a tube-like configuration. The tape and rope are provided from supply spools.

  16. Airborne 2-Micron Double Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurement

    NASA Technical Reports Server (NTRS)

    Yu, Jirong; Petros, Mulugeta; Refaat, Tamer F.; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan; Murchison, Luke

    2015-01-01

    An airborne 2-micron double-pulsed Integrated Path Differential Absorption (IPDA) lidar has been developed for atmospheric CO2 measurements. This new 2-miron pulsed IPDA lidar has been flown in spring of 2014 for total ten flights with 27 flight hours. It provides high precision measurement capability by unambiguously eliminating contamination from aerosols and clouds that can bias the IPDA measurement.

  17. Savannah River Site Ingestion Pathway Methodology Manual for Airborne Radioactive Releases

    SciTech Connect

    Vincent, A.W. III

    2001-01-03

    This manual documents a recommended methodology for determining the ingestion pathway consequences of hypothetical accidental airborne radiological releases from facilities at the Savannah River Site. Both particulate and tritiated radioactive contaminants are addressed. Other approaches should be applied for evaluation of routine releases.

  18. Airborne 2-Micron Double Pulsed Direct Detection IPDA Lidar for Atmospheric CO2 Measurement

    NASA Astrophysics Data System (ADS)

    Yu, Jirong; Petros, Mulugeta; Refaat, Tamer; Reithmaier, Karl; Remus, Ruben; Singh, Upendra; Johnson, Will; Boyer, Charlie; Fay, James; Johnston, Susan; Murchison, Luke

    2016-06-01

    An airborne 2-micron double-pulsed Integrated Path Differential Absorption (IPDA) lidar has been developed for atmospheric CO2 measurements. This new instrument has been flown in spring of 2014 for a total of ten flights with 27 flight hours. This IPDA lidar provides high precision measurement capability by unambiguously eliminating contamination from aerosols and clouds that can bias the results.

  19. Curved PVDF airborne transducer.

    PubMed

    Wang, H; Toda, M

    1999-01-01

    In the application of airborne ultrasonic ranging measurement, a partially cylindrical (curved) PVDF transducer can effectively couple ultrasound into the air and generate strong sound pressure. Because of its geometrical features, the ultrasound beam angles of a curved PVDF transducer can be unsymmetrical (i.e., broad horizontally and narrow vertically). This feature is desired in some applications. In this work, a curved PVDF air transducer is investigated both theoretically and experimentally. Two resonances were observed in this transducer. They are length extensional mode and flexural bending mode. Surface vibration profiles of these two modes were measured by a laser vibrometer. It was found from the experiment that the surface vibration was not uniform along the curvature direction for both vibration modes. Theoretical calculations based on a model developed in this work confirmed the experimental results. Two displacement peaks were found in the piezoelectric active direction of PVDF film for the length extensional mode; three peaks were found for the flexural bending mode. The observed peak positions were in good agreement with the calculation results. Transient surface displacement measurements revealed that vibration peaks were in phase for the length extensional mode and out of phase for the flexural bending mode. Therefore, the length extensional mode can generate a stronger ultrasound wave than the flexural bending mode. The resonance frequencies and vibration amplitudes of the two modes strongly depend on the structure parameters as well as the material properties. For the transducer design, the theoretical model developed in this work can be used to optimize the ultrasound performance.

  20. Airborne Crowd Density Estimation

    NASA Astrophysics Data System (ADS)

    Meynberg, O.; Kuschk, G.

    2013-10-01

    This paper proposes a new method for estimating human crowd densities from aerial imagery. Applications benefiting from an accurate crowd monitoring system are mainly found in the security sector. Normally crowd density estimation is done through in-situ camera systems mounted on high locations although this is not appropriate in case of very large crowds with thousands of people. Using airborne camera systems in these scenarios is a new research topic. Our method uses a preliminary filtering of the whole image space by suitable and fast interest point detection resulting in a number of image regions, possibly containing human crowds. Validation of these candidates is done by transforming the corresponding image patches into a low-dimensional and discriminative feature space and classifying the results using a support vector machine (SVM). The feature space is spanned by texture features computed by applying a Gabor filter bank with varying scale and orientation to the image patches. For evaluation, we use 5 different image datasets acquired by the 3K+ aerial camera system of the German Aerospace Center during real mass events like concerts or football games. To evaluate the robustness and generality of our method, these datasets are taken from different flight heights between 800 m and 1500 m above ground (keeping a fixed focal length) and varying daylight and shadow conditions. The results of our crowd density estimation are evaluated against a reference data set obtained by manually labeling tens of thousands individual persons in the corresponding datasets and show that our method is able to estimate human crowd densities in challenging realistic scenarios.

  1. Contaminated Sediment

    EPA Pesticide Factsheets

    Contaminated sediments are a significant problem in the Great Lakes basin. Persistent high concentrations of contaminants in the bottom sediments of rivers and harbors pose risks to aquatic organisms, wildlife, and humans.

  2. Determination of natural versus laboratory human infection with Mayaro virus by molecular analysis.

    PubMed

    Junt, T; Heraud, J M; Lelarge, J; Labeau, B; Talarmin, A

    1999-12-01

    A laboratory worker developed clinical signs of infection with Mayaro virus (Togaviridae), an arbovirus of South and Central America, 6 days after preparation of Mayaro viral antigen and 10 days after a trip to a rain forest. There was no evidence of skin lesions during the antigen preparation, and level 3 containment safety measures were followed. Therefore, molecular characterization of the virus was undertaken to identify the source of infection. RT-PCR and DNA sequence comparisons proved the infection was with the laboratory strain. Airborne Mayaro virus contamination is thus a hazard to laboratory personnel.

  3. An airborne isothermal haze chamber

    NASA Technical Reports Server (NTRS)

    Hindman, E. E.

    1981-01-01

    Thermal gradient diffusion cloud chambers (TGDCC) are used to determine the concentrations of cloud condensation nuclei (CCN) with critical supersaturations greater than or equal to about 0.2%. The CCN concentrations measured with the airborne IHC were lower than theoretically predicted by factors ranging between 7.9 and 9.0. The CCN concentrations measured with the airborne IHC were lower than the concentrations measured with the larger laboratory IHC's by factors ranging between 3.9 and 7.5. The bounds of the supersaturation ranges of the airborne IHC and the CSU-Mee TGDCC do not overlap. Nevertheless, the slopes of the interpolated data between the bounds agree favorably with the theoretical slopes.

  4. Airborne transmission of Bordetella pertussis.

    PubMed

    Warfel, Jason M; Beren, Joel; Merkel, Tod J

    2012-09-15

    Pertussis is a contagious, acute respiratory illness caused by the bacterial pathogen Bordetella pertussis. Although it is widely believed that transmission of B. pertussis occurs via aerosolized respiratory droplets, no controlled study has ever documented airborne transmission of pertussis. We set out to determine if airborne transmission occurs between infected and naive animals, utilizing the baboon model of pertussis. Our results showed that 100% of exposed naive animals became infected even when physical contact was prevented, demonstrating that pertussis transmission occurs via aerosolized respiratory droplets.

  5. Monitoring radioactive plumes by airborne gamma-ray spectrometry

    SciTech Connect

    Grasty, R.L.; Hovgaard, J.; Multala, J.

    1996-06-01

    Airborne gamma-ray spectrometer surveys using large volume sodium-iodide detectors are routinely flown throughout the world for mineral exploration and geological mapping. Techniques have now been developed to detect and map man-made sources of radiation. In Canada, airborne gamma-rays surveys have been flown around nuclear reactors to map {sup 41}Ar plumes from nuclear reactors and to calculate the dose rate at ground level. In May 1986, the Finnish Geological survey aircraft flew through a radioactive plume from the Chernobyl nuclear accident. As the aircraft flew through the plume, the aircraft became increasingly contaminated. By measuring the final aircraft contamination, the activity of the plume could be separated from the contamination due to the aircraft. Within 1 h of encountering the plume, the aircraft activity was comparable to the maximum levels found in the plume. From an analysis of the gamma-ray spectra, the concentration of {sup 131}I and {sup 140}La within the plume were calculated as a function of time.

  6. Effect of microclimate on particulate matter, airborne bacteria, and odorous compounds in swine nursery houses.

    PubMed

    Yao, H Q; Choi, H L; Lee, J H; Suresh, A; Zhu, K

    2010-11-01

    Nursery pigs are vulnerable to environmental risks associated with the microclimate and aerial contaminants. This study was carried out to assess the effect of microclimate (i.e., temperature, relative humidity, and air speed) on the quantity of particulate matter (PM), airborne bacteria, and odorants in nursery houses. Data were collected from 15 farms in different locations throughout South Korea during 4 seasons; daily sampling times were from 1000 to 1100 h in the morning. A nonparametric correlation analysis revealed correlations between microclimate variables and airborne contaminants in different seasons. Over the entire year, negative correlations were observed between temperature, air speed, and some odorous compounds (P < 0.05). Furthermore, negative correlations were observed between temperature, air speed, and relatively large airborne particulates, such as PM(10) (PM mean aerodynamic diameter ≤10 μm), PM(7) (PM mean aerodynamic diameter ≤7 μm), and total suspended particles (P < 0.05). A possible reason for these negative correlations is that increased ventilation at an increased room temperature could transfer most airborne particulates that are carried with odorous compounds out of the nursery houses. On the other hand, because of the sensitivity of coliform bacteria to temperature, positive correlations were observed between temperature and total coliform and Escherichia coli counts (P < 0.01). Because it is a challenging task to control the quantity of aerial contaminants in nursery houses, the relationships between the microclimate and airborne contaminants established in this study could be used to reduce those contaminants by controlling microclimate variables. The correlations established in the current study could also be helpful in establishing guidelines for good management practices in nursery houses.

  7. Airborne Electromagnetic Mapping of Subsurface Permafrost

    NASA Astrophysics Data System (ADS)

    Abraham, J. D.; Minsley, B. J.; Cannia, J. C.; Smith, B. D.; Walvoord, M. A.; Voss, C. I.; Jorgenson, T. T.; Wylie, B. K.; Anderson, L.

    2011-12-01

    Concerns over the impacts of climate change have recently energized research on the potential impacts thawing permafrost may have on groundwater flow, infrastructure, forest health, ecosystems, energy production, CO2 release, and contaminant transport. There is typically little knowledge about subsurface permafrost distributions, such as thickness and where groundwater-surface-water connections may occur through taliks. In June of 2010, the U.S. Geological Survey undertook an airborne electromagnetic (AEM) survey in the area of Fort Yukon, Alaska in order to map the 3-D distribution of permafrost and provide information for the development of groundwater models within the Yukon River Basin. Prior to the development of these models, information on areas of groundwater-surface water interaction was extremely limited. Lithology determined from a borehole drilled in Fort Yukon in 1994 agrees well with the resistivity depth sections inferred from the airborne survey. In addition to lithology, there a thermal imprint appears on the subsurface resistivity values. In the upper 20-50 m, the sections show continuous areas of high electrical resistivity, consistent with alluvial gravel deposits that are likely frozen. At depth, unfrozen gravel deposits have intermediate-to-high resistivity; frozen silts have intermediate resistivity; and unfrozen silts have low resistivity. Under the Yukon River and lakes where the subsurface is not frozen, zones of moderate resistivity intermix with areas of low resistivity. The areas of loess hills on the margins of the Yukon Flats have very-high electrical resistivity, indicating higher ice content, and are associated with the some of the greatest thickness of permafrost in the survey area. This work provides the first look into the 3-D distribution of permafrost in the areas around Fort Yukon and is a demonstration of the application of AEM to permafrost mapping. The AEM survey provides unprecedented 3-D images of subsurface electrical

  8. EVIDENCE OF AIRBORNE CONTAMINATION OF WESTERN NORTH AMERICAN MOUNTAIN ECOSYSTEMS

    EPA Science Inventory

    There is emerging evidence that mountain ecosystems in the western USA are receiving deposition of persistent bioaccumulative toxicants with origins in North America and elsewhere in the Northern Hemisphere. The toxic materials include metals and organic compounds. Of particula...

  9. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter Air Quality-Surface and... publication, entitled “TLV's Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH... 1330 Kemper Meadow Drive, Attn: Customer Service, Cincinnati, OH 45240, http://www.acgih.org, or may...

  10. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter Air Quality-Surface and... publication, entitled “TLV's Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH... 1330 Kemper Meadow Drive, Attn: Customer Service, Cincinnati, OH 45240, http://www.acgih.org, or may...

  11. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter Air Quality-Surface and... publication, entitled “TLV's Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH... 1330 Kemper Meadow Drive, Attn: Customer Service, Cincinnati, OH 45240, http://www.acgih.org, or may...

  12. 30 CFR 57.5001 - Exposure limits for airborne contaminants.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Air Quality, Radiation, Physical Agents, and Diesel Particulate Matter Air Quality-Surface and... publication, entitled “TLV's Threshold Limit Values for Chemical Substances in Workroom Air Adopted by ACGIH... 1330 Kemper Meadow Drive, Attn: Customer Service, Cincinnati, OH 45240, http://www.acgih.org, or may...

  13. Detection of airborne Legionella while showering using liquid impingement and fluorescent in situ hybridization (FISH).

    PubMed

    Deloge-Abarkan, Magali; Ha, Thi-Lan; Robine, Enric; Zmirou-Navier, Denis; Mathieu, Laurence

    2007-01-01

    Aerosols of water contaminated with Legionella bacteria constitute the only mode of exposure for humans. However, the prevention strategy against this pathogenic bacteria risk is managed through the survey of water contamination. No relationship linked the Legionella bacteria water concentration and their airborne abundance. Therefore, new approaches in the field of the metrological aspects of Legionella bioaerosols are required. This study was aimed at testing the main principles for bioaerosol collection (solid impaction, liquid impingement and filtration) and the in situ hybridization (FISH) method, both in laboratory and field assays, with the intention of applying such methodologies for airborne Legionella bacteria detection while showering. An aerosolization chamber was developed to generate controlled and reproducible L. pneumophila aerosols. This tool allowed the identification of the liquid impingement method as the most appropriate one for collecting airborne Legionella bacteria. The culturable fraction of airborne L. pneumophila recovered with the liquid impingement principle was 4 and 700 times higher compared to the impaction and filtration techniques, respectively. Moreover, the concentrations of airborne L. pneumophila in the impinger fluid were on average 7.0 x 10(5) FISH-cells m(-3) air with the fluorescent in situ hybridization (FISH) method versus 9.0 x 10(4) CFU m(-3) air with the culture method. These results, recorded under well-controlled conditions, were confirmed during the field experiments performed on aerosols generated by hot water showers in health institutions. This new approach may provide a more accurate characterization of aerobiocontamination by Legionella bacteria.

  14. Airborne cow allergen, ammonia and particulate matter at homes vary with distance to industrial scale dairy operations: an exposure assessment

    PubMed Central

    2011-01-01

    Background Community exposures to environmental contaminants from industrial scale dairy operations are poorly understood. The purpose of this study was to evaluate the impact of dairy operations on nearby communities by assessing airborne contaminants (particulate matter, ammonia, and cow allergen, Bos d 2) associated with dairy operations inside and outside homes. Methods The study was conducted in 40 homes in the Yakima Valley, Washington State where over 61 dairies operate. Results A concentration gradient was observed showing that airborne contaminants are significantly greater at homes within one-quarter mile (0.4 km) of dairy facilities, outdoor Bos d 2, ammonia, and TD were 60, eight, and two times higher as compared to homes greater than three miles (4.8 km) away. In addition median indoor airborne Bos d 2 and ammonia concentrations were approximately 10 and two times higher in homes within one-quarter mile (0.4 km) compared to homes greater than three miles (4.8 km) away. Conclusions These findings demonstrate that dairy operations increase community exposures to agents with known human health effects. This study also provides evidence that airborne biological contaminants (i.e. cow allergen) associated with airborne particulate matter are statistically elevated at distances up to three miles (4.8 km) from dairy operations. PMID:21838896

  15. Endotoxin exposure assessment in wood-processing industry: airborne versus settled dust levels.

    PubMed

    Pipinić, Ivana Sabolić; Varnai, Veda Marija; Lucić, Ruzica Beljo; Cavlović, Ankica; Prester, Ljerka; Orct, Tatjana; Macan, Jelena

    2010-06-01

    Wood processing is usually performed in environments with large amounts of endotoxin-rich bioaerosols that are associated with a variety of health effects. The aim of this preliminary study was to assess the relation between endotoxin levels in settled and airborne dust in wood-processing industry. Ten pairs of airborne and settled dust samples were collected in a sawmill and parquet manufacture of two wood-processing plants in Croatia. Endotoxin was assayed with a chromogenic end-point LAL (Limulus amebocyte lysate) method. The results showed that endotoxin levels in airborne respirable dust were above the proposed occupational exposure limit of 125 EU m(-3) and could be considered hazardous for the respiratory system. In settled dust they ranged between 229.7 EU mg(-1) and 604.3 EU mg(-1) and in airborne dust between 166.8 EU mg(-1) and 671.6 EU m(-3), but there was no significant correlation between them (Spearman's rho=0.358, P=0.310). This study points to sawmill settled dust as endotoxin reservoir and suggests that it may add to already high exposure to airborne endotoxins associated with wood processing. Investigations of the relation between settled and airborne endotoxin levels should be continued to better understand the sources and sites of endotoxin contamination in wood-processing industry.

  16. Airborne asbestos in public buildings

    SciTech Connect

    Chesson, J.; Hatfield, J.; Schultz, B.; Dutrow, E.; Blake, J. )

    1990-02-01

    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. 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.

  17. Tropospheric and Airborne Emission Spectrometers

    NASA Technical Reports Server (NTRS)

    Glavich, Thomas; Beer, Reinhard

    1996-01-01

    X This paper describes the development of two related instruments, the Tropospheric Emission Spectrometer (TES) and the Airborne Emission Spectrometer (AES). Both instruments are infrared imaging Fourier Transform Spectrometers, used for measuring the state of the lower atmosphere, and in particular the measurement of ozone and ozone sources and sinks.

  18. Airborne Imagery Collections Barrow 2013

    DOE Data Explorer

    Cherry, Jessica; Crowder, Kerri

    2015-07-20

    The data here are orthomosaics, digital surface models (DSMs), and individual frames captured during low altitude airborne flights in 2013 at the Barrow Environmental Observatory. The orthomosaics, thermal IR mosaics, and DSMs were generated from the individual frames using Structure from Motion techniques.

  19. AARD - Autonomous Airborne Refueling Demonstration

    NASA Technical Reports Server (NTRS)

    Ewers, Dick

    2007-01-01

    This viewgraph document reviews the Autonomous Airborne Refueling Demonstration program, and NASA Dryden's work in the program. The primary goal of the program is to make one fully automatic probe-to-drogue engagement using the AARD system. There are pictures of the aircraft approaching to the docking.

  20. What's New in the Site Characterization Tool Box: Molecular Biological Tools to Identify Microorganisms that Degrade Contaminants and Contaminant-Specific Isotope Analysis to Identify Sources and Document Degradation

    EPA Science Inventory

    In the past, it was necessary to conduct intensive sampling and monitoring of concentrations of contaminants in ground water to trace plumes back to their true source. Now it is possible to determine the ratio of stable isotopes of carbon, hydrogen or chlorine in the contaminan...

  1. Routing architecture and security for airborne networks

    NASA Astrophysics Data System (ADS)

    Deng, Hongmei; Xie, Peng; Li, Jason; Xu, Roger; Levy, Renato

    2009-05-01

    Airborne networks are envisioned to provide interconnectivity for terrestial and space networks by interconnecting highly mobile airborne platforms. A number of military applications are expected to be used by the operator, and all these applications require proper routing security support to establish correct route between communicating platforms in a timely manner. As airborne networks somewhat different from traditional wired and wireless networks (e.g., Internet, LAN, WLAN, MANET, etc), security aspects valid in these networks are not fully applicable to airborne networks. Designing an efficient security scheme to protect airborne networks is confronted with new requirements. In this paper, we first identify a candidate routing architecture, which works as an underlying structure for our proposed security scheme. And then we investigate the vulnerabilities and attack models against routing protocols in airborne networks. Based on these studies, we propose an integrated security solution to address routing security issues in airborne networks.

  2. The Use of Molecular and Genomic Techniques Applied to Microbial Diversity, Community Structure, and Activities at DNAPL and Metal Contaminated Sites

    EPA Science Inventory

    A wide variety of in situ subsurface remediation strategies have been developed to mitigate contamination by chlorinated solvent dense non-aqueous phase liquids (DNAPLS) and metals. Geochemical methods include: zerovalent iron emplacement, various electrolytic applications, elec...

  3. Can airborne ultrasound monitor bubble size in chocolate?

    NASA Astrophysics Data System (ADS)

    Watson, N.; Hazlehurst, T.; Povey, M.; Vieira, J.; Sundara, R.; Sandoz, J.-P.

    2014-04-01

    Aerated chocolate products consist of solid chocolate with the inclusion of bubbles and are a popular consumer product in many countries. The volume fraction and size distribution of the bubbles has an effect on their sensory properties and manufacturing cost. For these reasons it is important to have an online real time process monitoring system capable of measuring their bubble size distribution. As these products are eaten by consumers it is desirable that the monitoring system is non contact to avoid food contaminations. In this work we assess the feasibility of using an airborne ultrasound system to monitor the bubble size distribution in aerated chocolate bars. The experimental results from the airborne acoustic experiments were compared with theoretical results for known bubble size distributions using COMSOL Multiphysics. This combined experimental and theoretical approach is used to develop a greater understanding of how ultrasound propagates through aerated chocolate and to assess the feasibility of using airborne ultrasound to monitor bubble size distribution in these systems. The results indicated that a smaller bubble size distribution would result in an increase in attenuation through the product.

  4. Environmental contaminants

    USGS Publications Warehouse

    Custer, T.W.; Kushlna, J.A.; Hafner, H.

    2000-01-01

    Throughout the world, individuals and populations of herons are affected by environmental contaminants, leading to direct mortality, decreased reproductive success, or degradation of feeding habitat. Contaminants suspected or known to affect herons include organochlorine compounds, organophosphorus insecticides, trace elements, and petroleum (Parnell et al. 1988).General reviews on the effects of pesticides on birds (Risebrough 1986, 1991) and colonial water birds (Nisbet 1980) are presented elsewhere. The objective of this chapter is to review toxic effects of contaminants on herons. Unless otherwise noted, contaminant concentrations are presented as parts per million (ppm) on a wet weight (ww) basis.

  5. DEVELOPMENT OF SEPARATION SYSTEMS FOR POLYNUCLEAR AROMATIC HYDROCARBON ENVIRONMENTAL CONTAMINANTS USING MICELLAR ELECTROKINETIC CHROMATOGRAPHY WITH MOLECULAR MICELLES AND FREE ZONE ELECTROPHORESIS

    EPA Science Inventory

    Of four systems available from the literature, based on cyclodextrins, dioctylsulfosuccinate, bile salts, and molecular micelles consisting of oligomers of undecylenic acid, the most successful separation system in our hands is based on the molecular micelles, oligomers of sodiu...

  6. Apparatus Removes Organic Contaminants From Water

    NASA Technical Reports Server (NTRS)

    Akse, James R.; Thompson, John

    1994-01-01

    Catalytic-oxidation apparatus removes low-molecular-weight, polar, nonionizable organic contaminants from wastewater. Wastewater stream, previously treated by multifiltration process, pumped through apparatus for removal of trace organic contaminants. After injection of oxygen, flow preheated and enters catalytic reactor, where organic contaminants broken down into carbon dioxide and water. Carbon dioxide and unused oxygen removed in degasser.

  7. Space-Wise approach for airborne gravity data modelling

    NASA Astrophysics Data System (ADS)

    Sampietro, D.; Capponi, M.; Mansi, A. H.; Gatti, A.; Marchetti, P.; Sansò, F.

    2016-12-01

    Regional gravity field modelling by means of remove-compute-restore procedure is nowadays widely applied in different contexts: it is the most used technique for regional gravimetric geoid determination, and it is also used in exploration geophysics to predict grids of gravity anomalies (Bouguer, free-air, isostatic, etc.), which are useful to understand and map geological structures in a specific region. Considering this last application, due to the required accuracy and resolution, airborne gravity observations are usually adopted. However, due to the relatively high acquisition velocity, presence of atmospheric turbulence, aircraft vibration, instrumental drift, etc., airborne data are usually contaminated by a very high observation error. For this reason, a proper procedure to filter the raw observations in both the low and high frequencies should be applied to recover valuable information. In this work, a software to filter and grid raw airborne observations is presented: the proposed solution consists in a combination of an along-track Wiener filter and a classical Least Squares Collocation technique. Basically, the proposed procedure is an adaptation to airborne gravimetry of the Space-Wise approach, developed by Politecnico di Milano to process data coming from the ESA satellite mission GOCE. Among the main differences with respect to the satellite application of this approach, there is the fact that, while in processing GOCE data the stochastic characteristics of the observation error can be considered a-priori well known, in airborne gravimetry, due to the complex environment in which the observations are acquired, these characteristics are unknown and should be retrieved from the dataset itself. The presented solution is suited for airborne data analysis in order to be able to quickly filter and grid gravity observations in an easy way. Some innovative theoretical aspects focusing in particular on the theoretical covariance modelling are presented too

  8. Fixation of Radiological Contamination; International Collaborative Development

    SciTech Connect

    Rick Demmer

    2013-03-01

    A cooperative international project was conducted by the Idaho National Laboratory (INL) and the United Kingdom’s National Nuclear Laboratory (NNL) to integrate a capture coating with a high performance atomizing process. The initial results were promising, and lead to further trials. The somewhat longer testing and optimization process has resulted in a product that could be demonstrated in the field to reduce airborne radiological dust and contamination.

  9. Underwater Coatings for Contamination Control

    SciTech Connect

    Julia L. Tripp; Kip Archibald; Ann-Marie Phillips; Joseph Campbell

    2004-02-01

    The Idaho National Engineering and Environmental Laboratory (INEEL) is deactivating several fuel storage basins. Airborne contamination is a concern when the sides of the basins are exposed and allowed to dry during water removal. One way of controlling this airborne contamination is to fix the contamination in place while the pool walls are still submerged. There are many underwater coatings available on the market that are used in marine, naval and other applications. A series of tests were run to determine whether the candidate underwater fixatives are easily applied and adhere well to the substrates (pool wall materials) found in INEEL fuel pools. The four pools considered included 1) Test Area North (TAN-607) with epoxy painted concrete walls; 2) Idaho Nuclear Technology and Engineering Center (INTEC) (CPP-603) with bare concrete walls; 3) Materials Test Reactor (MTR) Canal with stainless steel lined concrete walls; and 4) Power Burst Facility (PBF-620) with stainless steel lined concrete walls on the bottom and epoxy painted carbon steel lined walls on the upper portions. Therefore, the four materials chosen for testing included bare concrete, epoxy painted concrete, epoxy painted carbon steel, and stainless steel. The typical water temperature of the pools varies from 55oF to 80oF dependent on the pool and the season. These tests were done at room temperature. The following criteria were used during this evaluation. The underwater coating must: · Be easy to apply · Adhere well to the four surfaces of interest · Not change or have a negative impact on water chemistry or clarity · Not be hazardous in final applied form · Be proven in other underwater applications. In addition, it is desirable for the coating to have a high pigment or high cross-link density to prevent radiation from penetrating. This paper will detail the testing completed and the test results. A proprietary two-part, underwater epoxy owned by S. G. Pinney and Associates was selected to

  10. Evaluation of principal cannabinoids in airborne particulates.

    PubMed

    Balducci, C; Nervegna, G; Cecinato, A

    2009-05-08

    The determination of delta(9)-tetrahydrocannabinol (Delta9-THC), cannabidiol (CND) and cannabinol (CNB), primary active components in cannabis preparation, was carried out on airborne particulates by applying a specific procedure consisting of soot extraction by ultrasonic bath, purification by solvent partitioning, derivatization with N-(t-butyldimethylsilyl)-N-methyl-trifluoroacetamide, and separation/detection through gas chromatography coupled with tandem mass spectrometry. The optimized procedure was found suitable for measuring the three psychotropic substances at concentrations ranging from ca. 0.001 to ca. 5.0 ng cm(-3) of air, with recoveries always higher than 82%, accuracy >7.3% and precision >90%. Application of the procedure performed on field in Rome and Bari, Italy, demonstrated that all three compounds contaminate the air in Italian cities whereas in Algiers, Algeria, only cannabinol, the most stable in the atmosphere, exceeded the limit of quantification of the method. The relative percentages of the three cannabinoids in general reproduced those typical of the Cannabis sativa plant and were very different from those found in human blood, urine and sweat.

  11. Generation of airborne Listeria innocua from model floor drains.

    PubMed

    Berrang, Mark E; Frank, Joseph F

    2012-07-01

    Listeria monocytogenes can colonize floor drains in poultry processing and further processing facilities, remaining present even after cleaning and disinfection. Therefore, during wash down, workers exercise caution to avoid spraying hoses directly into drains in an effort to prevent the escape and transfer of drain microflora to food contact surfaces. The objective of this study was to examine the extent to which an inadvertent water spray into a colonized floor drain can cause the spread of airborne Listeria. Listeria innocua was used to inoculate a polyvinyl chloride model floor drain, resulting in approximately 10(8) cells per ml of phosphate-buffered saline and 10(4) attached cells per square centimeter of inner surface. Each model drain was subjected to a 2-s spray of tap water at 68.9 kPa from a distance of 1 m. Drains were sprayed while filled and again after emptying. Airborne cells were collected by using sedimentation plates containing Listeria selective agar which were placed on the floor and walls of a contained room at incremental horizontal and vertical distances of 0.6, 1.2, 2.4, or 4.0 m from the drain. Sedimentation plates were exposed for 10 min. A mechanical sampler was used to also collect air by impaction on the surface of Listeria selective agar to determine the number of cells per liter of air. The experiment was conducted in triplicate rooms for each of four replications. L. innocua was detected on sedimentation plates on the floor as far as 4.0 m from the drain and on walls as high as 2.4 m above the floor and 4 m from the drain. A 2-s spray with a water hose into a contaminated drain can cause airborne spread of Listeria, resulting in the potential for cross-contamination of food contact surfaces, equipment, and exposed product.

  12. Detection of airborne polyoma virus.

    PubMed Central

    McGarrity, G. J.; Dion, A. S.

    1978-01-01

    Polyoma virus was recovered from the air of an animal laboratory housing mice infected with the virus. Air samples were obtained by means of a high volume air sampler and further concentrated by high speed centrifugation. Total concentration of the air samples was 7.5 x 10(7). Assay for polyoma virus was by mouse antibody production tests. Airborne polyoma virus was detected in four of six samples. PMID:211163

  13. The Future of Airborne Reconnaissance

    DTIC Science & Technology

    1996-01-01

    biplanes to the worldwide Cold War missions of the U - 2 and SR-71, airborne reconnaissance has become an indispensable tool to the intelligence community...Reconnaissance Operations (SRO) procedures, such as the U - 2 , RC- 135, and the EP-3, and traditional theater/fleet tactical reconnaissance systems like...upgraded sensor package on the U -2.14 The Army Staffs argument centers around command and control of the asset. The Army agreed that the U - 2 ’s

  14. Controlling Beryllium Contaminated Material And Equipment For The Building 9201-5 Legacy Material Disposition Project

    SciTech Connect

    Reynolds, T. D.; Easterling, S. D.

    2010-10-01

    This position paper addresses the management of beryllium contamination on legacy waste. The goal of the beryllium management program is to protect human health and the environment by preventing the release of beryllium through controlling surface contamination. Studies have shown by controlling beryllium surface contamination, potential airborne contamination is reduced or eliminated. Although there are areas in Building 9201-5 that are contaminated with radioactive materials and mercury, only beryllium contamination is addressed in this management plan. The overall goal of this initiative is the compliant packaging and disposal of beryllium waste from the 9201-5 Legacy Material Removal (LMR) Project to ensure that beryllium surface contamination and any potential airborne release of beryllium is controlled to levels as low as practicable in accordance with 10 CFR 850.25.

  15. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

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

  16. Contamination of optical surfaces. [Space Station

    NASA Technical Reports Server (NTRS)

    Arnold, Graham S.; Hall, David F.

    1988-01-01

    The effect of molecular contamination on Space Station optical surfaces is examined. In particular, contamination of solar voltaic power sources and optical solar reflectors for thermal control or solar dynamic power generation is addressed. The published Space Station requirements for molecular contamination accretion and for the monitoring of such accretion is discussed in the context of the historical performance of space systems. Specific reference is made to the results from the Spacecraft Charging at High Altitudes (SCATHA) ML12 experiment.

  17. Environmental Protection Agency (EPA) airborne gamma spectrometry system for environmental and emergency response surveys

    NASA Astrophysics Data System (ADS)

    Cardarelli, John, II; Thomas, Mark; Curry, Timothy

    2010-08-01

    The EPA Airborne Spectral Photometric Environmental Collection Technology (ASPECT) Program provides airborne ortho-rectified imagery, video, chemical and now radiological information directly to emergency response personnel via a commercial satellite link onboard the aircraft. EPA initiated the ASPECT Gamma Emergency Mapper GEM Project in 2008 to improve its airborne gamma-screening and mapping capability for monitoring any ground-based gamma contamination. This paper will provide an overview of the system, which can be configured to carry six 2"x4"x16" NaI(Tl) detectors and two 3"x3" LaBr3(Ce) detectors or eight 2"x4"x16" NaI(Tl) detectors. The paper will provide an overview of the analysis of gamma radiation spectra, system limitations, and emergency response applications.

  18. Variable pattern contamination control under positive pressure

    SciTech Connect

    Philippi, H.M.

    1997-08-01

    Airborne contamination control in nuclear and biological laboratories is traditionally achieved by directing the space ventilation air at subatmospheric pressures in one fixed flow pattern. However, biological and nuclear contamination flow control in the new Biological Research Facility, to be commissioned at the Chalk River Laboratories in 1996, will have the flexibility to institute a number of contamination control patterns, all achieved at positive (above atmospheric) pressures. This flexibility feature, made possible by means of a digitally controlled ventilation system, changes the facility ventilation system from being a relatively rigid building service operated by plant personnel into a flexible building service which can be operated by the facility research personnel. This paper focuses on and describes the application of these unique contamination control features in the design of the new Biological Research Facility. 3 refs., 7 figs.

  19. Effect of air-conditioner on fungal contamination

    NASA Astrophysics Data System (ADS)

    Hamada, Nobuo; Fujita, Tadao

    Air-conditioners (AC) produce much dew and wet conditions inside their apparatus, when in operation. We studied the fungal contamination in AC and found that the average fungal contamination of AC filters was about 5-fold greater than that of a carpet, and Cladosporium and Penicillium were predominant in AC filters. The fungal contamination inside AC, which were used everyday, increased more markedly than those not used daily, e.g. a few days per week or rarely. Moreover, the airborne fungal contamination in rooms during air-conditioning was about 2-fold greater than one in rooms without AC, and was highest when air-conditioning started and decreased gradually with time. We recognized that the airborne fungal contamination was controlled by the environmental condition of the rooms, in which AC were used. It is suggested that AC might promote mold allergies in users via airborne fungal spores derived from the AC. On the other hand, AC was estimated to remove moisture in the room atmosphere and carpets, and reduce the relative humidity in rooms. It was found that the average fungal contamination in the house dust of carpets with AC was suppressed by two-third of that in rooms without AC. The use of AC for suppressing fungal hazards was discussed.

  20. Bioremediation of high molecular weight polyaromatic hydrocarbons co-contaminated with metals in liquid and soil slurries by metal tolerant PAHs degrading bacterial consortium.

    PubMed

    Thavamani, Palanisami; Megharaj, Mallavarapu; Naidu, Ravi

    2012-11-01

    Bioremediation of polyaromatic hydrocarbons (PAH) contaminated soils in the presence of heavy metals have proved to be difficult and often challenging due to the ability of toxic metals to inhibit PAH degradation by bacteria. In this study, a mixed bacterial culture designated as consortium-5 was isolated from a former manufactured gas plant (MGP) site. The ability of this consortium to utilise HMW PAHs such as pyrene and BaP as a sole carbon source in the presence of toxic metal Cd was demonstrated. Furthermore, this consortium has proven to be effective in degradation of HMW PAHs even from the real long term contaminated MGP soil. Thus, the results of this study demonstrate the great potential of this consortium for field scale bioremediation of PAHs in long term mix contaminated soils such as MGP sites. To our knowledge this is the first study to isolate and characterize metal tolerant HMW PAH degrading bacterial consortium which shows great potential in bioremediation of mixed contaminated soils such as MGP.

  1. Adhesive-tape recovery combined with molecular and microscopic testing for the detection of Cryptosporidium oocysts on experimentally contaminated fresh produce

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryptosporidium parvum suspended in water were applied to the surface of apples, cucumbers, peaches, and tomatoes at concentrations of 100, 50 or 10 oocysts within circles drawn with a permanent marker. Approximately 18 hr later, skin containing uncontaminated and contaminated circles from each prod...

  2. Asbestos-fiber reentrainment during dry vacuuming and wet cleaning of asbestos-contaminated carpet. Report for January 1988-July 1989

    SciTech Connect

    Kominsky, J.R.; Freyberg, R.W.

    1991-03-01

    A study was conducted to evaluate the potential for asbestos fiber reentrainment during cleaning of carpet contaminated with asbestos. Two types of carpet cleaning equipment were evaluated at two carpet contamination levels. Airborne asbestos concentrations were determined before and during carpet cleaning. Overall, airborne asbestos concentrations were two to four times greater during the carpet cleaning activity. The level of asbestos contamination and the type of cleaning method used had no statistically significant effect on the relative increase of airborne asbestos concentrations during carpet cleaning.

  3. Contamination Impact of Station Brush Fire on Cleanroom Facilities

    NASA Technical Reports Server (NTRS)

    Carey, Phil; Blakkolb, Brian

    2010-01-01

    Brush and forest fires, both naturally occurring and anthropogenic in origin, in proximity to space flight hardware processing facilities raise concerns about the threat of contamination resulting from airborne particulate and molecular components of smoke. Perceptions of the severity of the threat are possibly heightened by the high sensitivity of the human sense of smell to some components present in the smoke of burning vegetation.On August 26th, 2009, a brushfire broke out north of Pasadena, California, two miles from the Jet Propulsion Laboratory. The Station Fire destroyed over 160,000 acres, coming within a few hundred yards of JPL. Smoke concentrations on Lab were very heavy over several days. All Lab operations were halted, and measures were taken to protect personnel, critical hardware, and facilities. Evaluation of real-time cleanroom monitoring data, visualinspection of facilities, filter systems, and analysis of surface cleanliness samples revealed facility environments andhardware were minimally effected.Outside air quality easily exceeded Class Ten Million. Prefilters captured most large ash and soot; multi-stage filtration greatly minimized the impact on the HEPA/ULPA filters. Air quality in HEPA filtered spacecraft assembly cleanrooms remained within Class 10,000 specification throughout. Surface cleanliness was inimally affected, as large particles were effectively removed from the airstream, and sub-micron particles have extremely long settling rates. Approximate particulate fallout within facilities was 0.00011% area coverage/day compared to 0.00038% area coverage/day during normal operations. Deposition of condensable airborne components, as measured in real time, peaked at approximately1.0 ng/cm2/day compared to 0.05 ng/cm2/day nominal.

  4. Contamination Control

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Upjohn Company sought a solution to their problem of potential particulate contamination of sterile injectable drugs. Contamination was caused by dust particles attracted by static electrical charge, which clung to plastic curtains in clean rooms. Upjohn found guidance in NASA Tech Briefs which provided detailed information for reducing static electricity. Guidelines for setting up static free work stations, materials and equipment needed to maintain antistatic protection.

  5. Exposure of workers to airborne microorganisms in open-air swine houses.

    PubMed

    Chang, C W; Chung, H; Huang, C F; Su, H J

    2001-01-01

    This study quantified the levels of airborne microorganisms in six swine farms with more than 10,000 pigs in subtropical Taiwan. We evaluated breeding, growing, and finishing stalls, which were primarily open-air buildings, as well as partially enclosed farrowing and nursery piggeries. Airborne culturable bacteria, gram-negative bacteria, and fungi were placed on appropriate media by using an all-glass impinger or single-stage Andersen microbial sampler. Results showed that mean concentrations of culturable bacteria and gram-negative bacteria were 3.3 x 10(5) and 143.7 CFU/m(3), respectively. The concentration of airborne culturable fungi was about 10(3) CFU/m(3), with Cladosporium the predominant genus. The highest airborne levels of culturable bacteria and gram-negative bacteria were identified in the finishing units. The air of the nursery stalls was the least contaminated with culturable and gram-negative bacteria. Irregular and infrequent cleaning, high pig density, no separation of wastes from pen floors, and accumulation of water as a result of the processes for cleaning and reducing pig temperature possibly compromise the benefits of the open characteristic of the finishing units with respect to airborne bacterial concentration.

  6. EVALUATION OF THREE CLEANING METHODS FOR REMOVING ASBESTOS FROM CARPET. DETERMINATION OF AIRBORNE ASBESTOS CONCENTRATIONS ASSOCIATED WITH EACH METHOD

    EPA Science Inventory

    This study was conducted to compare the effectiveness of three cleaning methods to remove asbestos from contaminated carpet and to determine the airborne asbestos concentrations associated with the use of each method. The carpet on which the methods were tested was naturally cont...

  7. Airborne High Spectral Resolution Lidar Measurements of Atmospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Ferrare, R.; Hostetler, C.; Hair, J.; Cook, A.; Harper, D.; Kleinman, L.; Clarke, A.; Russell, P.; Redemann, J.; Livingston, J.; Szykman, J.; Al-Saadi, J.

    2007-05-01

    NASA Langley Research Center (LaRC) recently developed an airborne High Spectral Resolution Lidar (HSRL) to measure aerosol distributions and optical properties. The HSRL technique takes advantage of the spectral distribution of the lidar return signal to discriminate aerosol and molecular signals and thereby measure aerosol extinction and backscatter independently. The LaRC instrument employs the HSRL technique to measure aerosol backscatter and extinction profiles at 532 nm and the standard backscatter lidar technique to measure aerosol backscatter profiles at 1064 nm. Depolarization profiles are measured at both wavelengths. Since March 2006, the airborne HSRL has acquired over 215 flight hours of data deployed on the NASA King Air B200 aircraft during several field experiments. Most of the flights were conducted during two major field experiments. The first major experiment was the joint Megacity Initiative: Local and Global Research Observations (MILAGRO) /Megacity Aerosol Experiment in Mexico City (MAX-MEX)/Intercontinental Chemical Transport Experiment-B (INTEX B) experiment that was conducted during March 2006 to investigate the evolution and transport of pollution from Mexico City. The second major experiment was the Texas Air Quality Study (TEXAQS)/Gulf of Mexico Atmospheric Composition and Climate Study (GoMACCS) that was conducted during August and September 2006 to investigate climate and air quality in the Houston/Gulf of Mexico region. Several flights were also conducted to help validate the Cloud-Aerosol LIdar with Orthogonal Polarization (CALIOP) lidar on board the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite (CALIPSO) satellite. In February 2007, several flights were carried out as part of an Environmental Protection Agency (EPA) experiment to assess air quality in central California. Airborne HSRL data acquired during these missions were used to quantify aerosol extinction and optical thickness contributed by various aerosol types

  8. Stability of airborne microbes in the Louvre Museum over time.

    PubMed

    Gaüzère, C; Moletta-Denat, M; Blanquart, H; Ferreira, S; Moularat, S; Godon, J-J; Robine, E

    2014-02-01

    The microbial content of air has as yet been little described, despite its public health implications, and there remains a lack of environmental microbial data on airborne microflora in enclosed spaces. In this context, the aim of this study was to characterize the diversity and dynamics of airborne microorganisms in the Louvre Museum using high-throughput molecular tools and to underline the microbial signature of indoor air in this human-occupied environment. This microbial community was monitored for 6 month during occupied time. The quantitative results revealed variations in the concentrations of less than one logarithm, with average values of 10(3) and 10(4) Escherichia coli/Aspergillus fumigatus genome equivalent per m(3) for bacteria and fungi, respectively. Our observations highlight the stability of the indoor airborne bacterial diversity over time, while the corresponding eukaryote community was less stable. Bacterial diversity characterized by pyrosequencing 454 showed high diversity dominated by the Proteobacteria which represented 51.1%, 46.9%, and 38.4% of sequences, for each of the three air samples sequenced. A common bacterial diversity was underlined, corresponding to 58.4% of the sequences. The core species were belonging mostly to the Proteobacteria and Actinobacteria, and to the genus Paracoccus spp., Acinetobacter sp., Pseudomonas sp., Enhydrobacter sp., Sphingomonas sp., Staphylococcus sp., and Streptococcus sp.

  9. Exposure assessment to airborne endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide in open style swine houses.

    PubMed

    Chang, C W; Chung, H; Huang, C F; Su, H J

    2001-08-01

    Information is limited for the exposure levels of airborne hazardous substances in swine feed buildings that are not completely enclosed. Open-style breeding, growing and finishing swine houses in six farms in subtropical Taiwan were studied for the airborne concentrations of endotoxin, dust, ammonia, hydrogen sulfide and carbon dioxide. The air in the farrowing and nursery stalls as partially enclosed was also simultaneously evaluated. Three selected gases and airborne dusts were quantified respectively by using Drager diffusion tubes and a filter-weighing method. Endotoxin was analyzed by the Limulus amoebocyte lysate assay. Average concentration of airborne total endotoxin among piggeries was between 36.8 and 298 EU/m(3), while that for respirable endotoxin was 14.1-129 EU/m(3). Mean concentration of total dust was between 0.15 and 0.34 mg/m(3), with average level of respirable dust of 0.14 mg/m(3). The respective concentrations of NH3, CO2 and H2S were less than 5 ppm, 600-895 ppm and less than 0.2 ppm. Airborne concentrations of total dust and endotoxin in the nursery house were higher than in the other types of swine houses. The finishing house presented the highest exposure risk to NH3, CO2 and H2S. Employees working in the finishing stalls were also exposed to the highest airborne levels of respirable endotoxin and dust. On the other hand, the air of the breeding units was the least contaminated in terms of airborne endotoxin, dust, NH3, CO2 and H2S. The airborne concentrations of substances measured in the present study were all lower than most of published studies conducted in mainly enclosed swine buildings. Distinct characteristics, including maintaining swine houses in an open status and frequent spraying water inside the stalls, significantly reduce accumulation of gases and airborne particulates.

  10. Effect of heavy metals and organic matter on root exudates (low molecular weight organic acids) of herbaceous species: An assessment in sand and soil conditions under different levels of contamination.

    PubMed

    Montiel-Rozas, M M; Madejón, E; Madejón, P

    2016-09-01

    Bioavailability of heavy metals can be modified by different root exudates. Among them, low molecular weight organic acids (LMWOAs) play an important role in this process. Three plant species (Poa annua, Medicago polymorpha and Malva sylvestris), potentially used for phytoremediation, have been assessed for both metal uptake and LMWOAs excretion in contaminated environments with different concentrations of Cd, Cu and Zn. The experiments have been carried out in washed sand and in three contaminated soils where two organic amendments were added (biosolid compost and alperujo compost). The most abundant LMWOAs excreted by all studied plants were oxalic and malic acids, although citric and fumaric acids were also detected. The general tendency was that plants responded to an increase of heavy metal stress releasing higher amounts of LMWOAs. This is an efficient exclusion mechanism reducing the metal uptake and allowing the plant growth at high levels of contamination. In the experiment using wash sand as substrate, the organic acids composition and quantity depended mainly on plant species and metal contamination. M. polymorpha was the species that released the highest concentrations of LMWOAs, both in sand and in soils with no amendment addition, whereas a decrease of these acids was observed with the addition of amendments. Our results established a clear effect of organic matter on the composition and total amount of LMWOAs released. The increase of organic matter and nutrients, through amendments, improved the soil quality reducing phytotoxicity. As a result, organic acids exudates decreased and were solely composed of oxalic acid (except for M. polymorpha). The release of LMWOAs has proved to be an important mechanism against heavy metal stress, unique to each species and modifiable by means of organic amendment addition.

  11. Airborne Research Experience for Educators

    NASA Astrophysics Data System (ADS)

    Costa, V. B.; Albertson, R.; Smith, S.; Stockman, S. A.

    2009-12-01

    The Airborne Research Experience for Educators (AREE) Program, conducted by the NASA Dryden Flight Research Center Office of Education in partnership with the AERO Institute, NASA Teaching From Space Program, and California State University Fullerton, is a complete end-to-end residential research experience in airborne remote sensing and atmospheric science. The 2009 program engaged ten secondary educators who specialize in science, technology, engineering or mathematics in a 6-week Student Airborne Research Program (SARP) offered through NSERC. Educators participated in collection of in-flight remote sensor data during flights aboard the NASA DC-8 as well as in-situ research on atmospheric chemistry (bovine emissions of methane); algal blooms (remote sensing to determine location and degree of blooms for further in-situ analysis); and crop classification (exploration of how drought conditions in Central California have impacted almond and cotton crops). AREE represents a unique model of the STEM teacher-as-researcher professional development experience because it asks educators to participate in a research experience and then translate their experiences into classroom practice through the design, implementation, and evaluation of instructional materials that emphasize the scientific research process, inquiry-based investigations, and manipulation of real data. Each AREE Master Educator drafted a Curriculum Brief, Teachers Guide, and accompanying resources for a topic in their teaching assignment Currently, most professional development programs offer either a research experience OR a curriculum development experience. The dual nature of the AREE model engaged educators in both experiences. Educators’ content and pedagogical knowledge of STEM was increased through the review of pertinent research articles during the first week, attendance at lectures and workshops during the second week, and participation in the airborne and in-situ research studies, data

  12. Requirements for airborne vector gravimetry

    NASA Technical Reports Server (NTRS)

    Schwarz, K. P.; Colombo, O.; Hein, G.; Knickmeyer, E. T.

    1992-01-01

    The objective of airborne vector gravimetry is the determination of the full gravity disturbance vector along the aircraft trajectory. The paper briefly outlines the concept of this method using a combination of inertial and GPS-satellite data. The accuracy requirements for users in geodesy and solid earth geophysics, oceanography and exploration geophysics are then specified. Using these requirements, accuracy specifications for the GPS subsystem and the INS subsystem are developed. The integration of the subsystems and the problems connected with it are briefly discussed and operational methods are indicated that might reduce some of the stringent accuracy requirements.

  13. Cyberinfrastructure for Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.

    2009-01-01

    Since 2004 the NASA Airborne Science Program has been prototyping and using infrastructure that enables researchers to interact with each other and with their instruments via network communications. This infrastructure uses satellite links and an evolving suite of applications and services that leverage open-source software. The use of these tools has increased near-real-time situational awareness during field operations, resulting in productivity improvements and the collection of better data. This paper describes the high-level system architecture and major components, with example highlights from the use of the infrastructure. The paper concludes with a discussion of ongoing efforts to transition to operational status.

  14. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.J.; Keiswetter, D.

    1995-10-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits rapid geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected.

  15. Geophex airborne unmanned survey system

    SciTech Connect

    Won, I.J.; Taylor, D.W.A.

    1995-03-01

    The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This nonintrusive system will provide {open_quotes}stand-off{close_quotes} capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. This system permits two operators to rapidly conduct geophysical characterization of hazardous environmental sites. During a survey, the operators remain remote from, but within visual distance, of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak anomalies can be detected.

  16. Adhesive-tape recovery combined with molecular and microscopic testing for the detection of Cryptosporidium oocysts on experimentally contaminated fresh produce and a food preparation surface.

    PubMed

    Fayer, Ronald; Santin, Monica; Macarisin, Dumitru; Bauchan, Gary

    2013-04-01

    A proof of concept study was conducted to determine if transparent double-sided adhesive tape could be used to recover and detect [by polymerase chain reaction (PCR) and immunofluorescence microscopy (IFA)] Cryptosporidium parvum oocysts on fresh produce and on a food preparation surface. Oocysts were applied on the surface of ten apples, ten peaches, eight cucumbers, and eight tomatoes within circles drawn with a permanent marker. Approximately 18 h later, skin excised from three uncontaminated and three contaminated circles from each piece of produce was subjected to PCR. Pieces of transparent double-sided adhesive tape were lightly pressed onto the surface of three other contaminated circles and examined by PCR. Other pieces of adhesive tape were pressed against the surfaces of three other circles and examined by IFA. At concentrations of 100 and 50 oocysts per circle, every produce item examined by PCR of contaminated excised skin was found positive, and every item examined by adhesive tape subjected to PCR and IFA was found positive, except one. At ten oocysts per circle, every produce item was found positive by PCR of contaminated excised skin, and all apples, cucumbers, and tomatoes were found positive by adhesive tape subjected to IFA. Detection of low numbers of oocysts on peaches by IFA examination of adhesive tape was problematic because trichomes that cover peaches and impart the fuzzy surface partially restrict the tape from reaching some areas where oocysts adhere. Tape combined with IFA was successful in recovering and identifying oocysts from six areas of laminate countertop where the oocysts had been applied and allowed to dry for 30-60 min. These are the first findings to demonstrate that adhesive tape can be used to recover and identify a protozoan parasite from fresh produce and from a laminate food preparation surface.

  17. A molecular epidemiological study of methicillin-resistant Staphylococci environmental contamination in railway stations and coach stations in Guangzhou of China.

    PubMed

    Lin, J L; Peng, Y; Ou, Q T; Lin, D X; Li, Y; Ye, X H; Zhou, J L; Yao, Z J

    2017-02-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has caused a series of public health problems since it was first found in 1961. However, there are few research studies on the MRSA environmental contamination in railway stations and coach stations. Therefore, the aim of this study was to determine MRSA environmental contamination in public transport stations. Between December 2013 and January 2014, 380 surface samples from three railway stations (180) and four coach stations (200) in Guangzhou were collected to isolate and determine the prevalence and characteristics of Staphylococci strains. 39·21% of all samples were Staphylococci isolates, 1·58% of Staphylococci isolates were MRSA isolates, and 6·05% were methicillin-susceptible S. aureus. The proportion of multidrug resistant among 149 Staphylococci isolates was 75·84%. None of MRSA isolates was identified with the Panton-Valentine Leukocidin (PVL) genes, and one of them was identified with the qac gene. Four MRSA isolates were Staphylococcal Cassette Chromosome mec IVa, and the other two were nontypeable. Staphylococcus aureus isolates were classified into several sequence types (STs), and STs showed possible cross-transmissions of isolates from various sources. Methicillin-resistant Staphylococci contamination prevalence was high, and the environment of stations may be the vectors transmitting the Staphylococci to passengers.

  18. Airborne Oceanographic Lidar (AOL) (Global Carbon Cycle)

    NASA Technical Reports Server (NTRS)

    2003-01-01

    This bimonthly contractor progress report covers the operation, maintenance and data management of the Airborne Oceanographic Lidar and the Airborne Topographic Mapper. Monthly activities included: mission planning, sensor operation and calibration, data processing, data analysis, network development and maintenance and instrument maintenance engineering and fabrication.

  19. Airborne Visible Laser Optical Communications Program (AVLOC)

    NASA Technical Reports Server (NTRS)

    Ward, J. H.

    1975-01-01

    The design, development, and operation of airborne and ground-based laser communications and laser radar hardware is described in support of the Airborne Visible Laser Optical Communication program. The major emphasis is placed on the development of a highly flexible test bed for the evaluation of laser communications systems techniques and components in an operational environment.

  20. A Simple Method for Collecting Airborne Pollen

    ERIC Educational Resources Information Center

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  1. Global Test Range: Toward Airborne Sensor Webs

    NASA Technical Reports Server (NTRS)

    Mace, Thomas H.; Freudinger, Larry; DelFrate John H.

    2008-01-01

    This viewgraph presentation reviews the planned global sensor network that will monitor the Earth's climate, and resources using airborne sensor systems. The vision is an intelligent, affordable Earth Observation System. Global Test Range is a lab developing trustworthy services for airborne instruments - a specialized Internet Service Provider. There is discussion of several current and planned missions.

  2. Meeting Review: Airborne Aerosol Inlet Workshop

    NASA Technical Reports Server (NTRS)

    Baumgardner, Darrel; Huebert, Barry; Wilson, Chuck

    1991-01-01

    Proceedings from the Airborne Aerosol Inlet Workshop are presented. The two central topics of discussion were the role of aerosols in atmospheric processes and the difficulties in characterizing aerosols. The following topics were discussed during the working sessions: airborne observations to date; identification of inlet design issues; inlet modeling needs and directions; objectives for aircraft experiments; and future laboratory and wind tunnel studies.

  3. Airborne Relay-Based Regional Positioning System

    PubMed Central

    Lee, Kyuman; Noh, Hongjun; Lim, Jaesung

    2015-01-01

    Ground-based pseudolite systems have some limitations, such as low vertical accuracy, multipath effects and near-far problems. These problems are not significant in airborne-based pseudolite systems. However, the monitoring of pseudolite positions is required because of the mobility of the platforms on which the pseudolites are mounted, and this causes performance degradation. To address these pseudolite system limitations, we propose an airborne relay-based regional positioning system that consists of a master station, reference stations, airborne relays and a user. In the proposed system, navigation signals are generated from the reference stations located on the ground and are relayed via the airborne relays. Unlike in conventional airborne-based systems, the user in the proposed system sequentially estimates both the locations of airborne relays and his/her own position. Therefore, a delay due to monitoring does not occur, and the accuracy is not affected by the movement of airborne relays. We conducted several simulations to evaluate the performance of the proposed system. Based on the simulation results, we demonstrated that the proposed system guarantees a higher accuracy than airborne-based pseudolite systems, and it is feasible despite the existence of clock offsets among reference stations. PMID:26029953

  4. Airborne Global Positioning System Antenna System

    DTIC Science & Technology

    2004-10-14

    GLOBAL POSITIONING SYSTEM ANTENNA SYSTEM DISTRIBUTION: SMC/ GP (3 cys); AFFSA...standard that airborne Global Positioning System ( GPS ) antenna system must meet to be identified with the applicable MSO marking. The similarity of...UNCLASSIFIED DOCUMENT NO. DATE NO. MSO-C144 14 Oct 04 Initial Release REV: REV: SHEET 1 OF 16 TITLE: AIRBORNE GLOBAL POSITIONING SYSTEM

  5. High Energy 2-Micron Solid-State Laser Transmitter for NASA's Airborne CO2 Measurements

    NASA Technical Reports Server (NTRS)

    Singh, Upendra N.; Yu, Jirong; Petros, Mulugeta; Bai, Yingxin

    2012-01-01

    A 2-micron pulsed, Integrated Path Differential Absorption (IPDA) lidar instrument for ground and airborne atmospheric CO2 concentration measurements via direct detection method is being developed at NASA Langley Research Center. This instrument will provide an alternate approach to measure atmospheric CO2 concentrations with significant advantages. A high energy pulsed approach provides high-precision measurement capability by having high signal-to-noise level and unambiguously eliminates the contamination from aerosols and clouds that can bias the IPDA measurement.

  6. Environmental contaminants

    USGS Publications Warehouse

    Hoffman, D.J.; Rattner, B.A.; Scheunert, I.; Korte, F.; Shore, Richard F.; Rattner, Barnett A.

    2001-01-01

    The purpose of this chapter is to provide an overview of the ecotoxicology of major classes of environmental contaminants, with respect to sources, environmental chemistry, most likely routes of exposure, potential bioaccumulation and biomagification, mechanisms of toxicity, and effects on potentially vulnerable species of mammalian wildlife. Major contaminants reviewed were selected on the basis of their use patterns, availability and potential toxicity to wild mammals. These included pesticides used in agroecosystems (organochlorines, organophosphorus and carbamate compounds, anticoagulants, herbicides and fungicides), various organic pollutants (chlorobenzenes, chlorophenols, polychlorinated biphenyls, dibenzodioxins and dibenzofurans, and polycyclic aromatic hydrocarbons), heavy metals (lead, mercury, and cadmium), agricultural drainwater mixtures, leachates and radionuclides. Many of the above aspects of ecotoxicology and contaminants will be expanded upon in subsequent chapters of this book as they relate to distinct mammalian species and potential risk.

  7. ISMAR: an airborne submillimetre radiometer

    NASA Astrophysics Data System (ADS)

    Fox, Stuart; Lee, Clare; Moyna, Brian; Philipp, Martin; Rule, Ian; Rogers, Stuart; King, Robert; Oldfield, Matthew; Rea, Simon; Henry, Manju; Wang, Hui; Chawn Harlow, R.

    2017-02-01

    The International Submillimetre Airborne Radiometer (ISMAR) has been developed as an airborne demonstrator for the Ice Cloud Imager (ICI) that will be launched on board the next generation of European polar-orbiting weather satellites in the 2020s. It currently has 15 channels at frequencies between 118 and 664 GHz which are sensitive to scattering by cloud ice, and additional channels at 874 GHz are being developed. This paper presents an overview of ISMAR and describes the algorithms used for calibration. The main sources of bias in the measurements are evaluated, as well as the radiometric sensitivity in different measurement scenarios. It is shown that for downward views from high altitude, representative of a satellite viewing geometry, the bias in most channels is less than ±1 K and the NEΔT is less than 2 K, with many channels having an NEΔT less than 1 K. In-flight calibration accuracy is also evaluated by comparison of high-altitude zenith views with radiative-transfer simulations.

  8. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.L.; Keiswetter, D.

    1995-12-31

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

  9. Magnetic characterization of airborne particulates

    NASA Astrophysics Data System (ADS)

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

    2010-12-01

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

  10. (Contaminated soil)

    SciTech Connect

    Siegrist, R.L.

    1991-01-08

    The traveler attended the Third International Conference on Contaminated Soil, held in Karlsruhe, Germany. The Conference was a status conference for worldwide research and practice in contaminated soil assessment and environmental restoration, with more than 1500 attendees representing over 26 countries. The traveler made an oral presentation and presented a poster. At the Federal Institute for Water, Soil and Air Hygiene, the traveler met with Dr. Z. Filip, Director and Professor, and Dr. R. Smed-Hildmann, Research Scientist. Detailed discussions were held regarding the results and conclusions of a collaborative experiment concerning humic substance formation in waste-amended soils.

  11. Investigating physiological, cellular and molecular effects in juvenile blue crab, Callinectus sapidus, exposed to field-collected sediments contaminated by oil from the Deepwater Horizon Incident.

    PubMed

    Pie, Hannah V; Schott, Eric J; Mitchelmore, Carys L

    2015-11-01

    Juvenile blue crabs, Callinectus sapidus, were exposed for 31 days to six different sediments collected within the Pass a Loutre State Wildlife Management Area approximately 6 months or 1.5 years post-capping of the Macondo-252 well-head following the Deepwater Horizon (DWH) Incident. Based on forensic analysis to fingerprint for DWH oil, these sediments differed in their levels of DWH oil contamination, and included one reference sediment collected from a location with no detectable DWH oil present. The concentration of 50 individual parent and alkylation group polycyclic aromatic hydrocarbons (PAHs), saturated hydrocarbons (37 total), and total extractable hydrocarbons were determined in each sediment, as were biologically relevant metals, grain size distribution, percent total organic carbon, and percent total solids. Total concentrations of 50 PAHs (TPAH50) of initial treatment sediments ranged from 187 μg kg(-1) (reference site) to 2,086,458 μg kg(-1) (the highest DWH oil contaminated site). Multiple biological endpoints were measured including mortality, growth, and ecdysis. Additionally, early biomarkers of biological stress were examined in the hemolymph and hepatopancreas of crabs, including DNA damage (Comet assay) and expression of genes encoding Cu-metallothionein (CuMT), glutathione-S-transferase (GST), and manganese superoxide dismutase (MnSOD). Over the 31 day exposure, there were no treatment related mortalities in juvenile blue crabs. The overall growth and molting of the crabs were not substantially different between the various sediment exposures over the exposure period. Additionally, none of the early biomarkers of biological stress were correlated with PAH concentrations. Overall, juvenile blue crabs did not appear to be negatively impacted during the 31 day exposure by DWH oil contaminated sediments collected at least 6 months post-capping of the Macondo-252 well-head.

  12. Applying Contamination Modelling to Spacecraft Propulsion Systems Designs and Operations

    NASA Technical Reports Server (NTRS)

    Chen, Philip T.; Thomson, Shaun; Woronowicz, Michael S.

    2000-01-01

    Molecular and particulate contaminants generated from the operations of a propulsion system may impinge on spacecraft critical surfaces. Plume depositions or clouds may hinder the spacecraft and instruments from performing normal operations. Firing thrusters will generate both molecular and particulate contaminants. How to minimize the contamination impact from the plume becomes very critical for a successful mission. The resulting effect from either molecular or particulate contamination of the thruster firing is very distinct. This paper will discuss the interconnection between the functions of spacecraft contamination modeling and propulsion system implementation. The paper will address an innovative contamination engineering approach implemented from the spacecraft concept design, manufacturing, integration and test (I&T), launch, to on- orbit operations. This paper will also summarize the implementation on several successful missions. Despite other contamination sources, only molecular contamination will be considered here.

  13. Groundwater contamination

    SciTech Connect

    Haimes, Y. . Dept. of Systems Engineering)

    1986-01-01

    The subject of these conference proceedings is the groundwater contamination. It is by nature multifarious - dealing with detection and monitoring, prevention, abatement and containment, and correction and restoration of contaminated groundwater - it intrinsically encompasses myriad disciplines, and it involves all levels of government. Also, the subject of groundwater contamination is complex because decisions concerning groundwater pollution control that are scientifically sound, technologically within the state of the art, economically feasible, politically tractable, legally sustainable, socially acceptable, morally accountable, and organizationally implementable must be grounded on appropriate information and intelligence bases in their respective areas - science, technology, economics, politics, the law, society, ethics, and management. Indeed, the human health effects (e.g., cancer, damage to the central nervous system, liver and kidney damage) and non-health effects (economic hardship to industry, agriculture, households, and municipalities; environmental impacts; social impacts) necessitate that we, as a society, address in a somber way the following variations of the same question: How safe is safe enough How clean is safe enough The enormous cost - in billions of dollars over the next decade - that various studies project for the prevention, detection and monitoring, abatement and containment, and correction and restoration of groundwater contamination make an answer to these questions even more urgent. There are sixteen papers in these proceedings.

  14. Unnecessary roughness? Testing the hypothesis that predators destined for molecular gut-content analysis must be hand-collected to avoid cross-contamination

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular gut-content analysis enables direct detection of arthropod predation with minimal disruption of on-going ecosystem processes. Mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, could lead to regurgitation or even rupturing of predators along with uneaten ...

  15. Ground water contamination

    SciTech Connect

    Not Available

    1991-01-01

    This book covers: Ground water contamination and basic concepts of water law; Federal law governing water contamination and remediation; Ground water flow and contaminant migration; Ground water cleanup under CERCLA; Technical methods of remediation and prevention of contamination; Liability for ground water contamination; State constraints on contamination of ground water; Water quantity versus water quality; Prevention of use of contaminated ground water as an alternative to remediation; Economic considerations in liability for ground water contamination; and Contamination, extraction, and injection issues.

  16. Airborne thermography or infrared remote sensing.

    PubMed

    Goillot, C C

    1975-01-01

    Airborne thermography is part of the more general remote sensing activity. The instruments suitable for image display are infrared line scanners. A great deal of interest has developed during the past 10 years in airborne thermal remote sensing and many applications are in progress. Infrared scanners on board a satellite are used for observation of cloud cover; airborne infrared scanners are used for forest fire detection, heat budget of soils, detecting insect attack, diseases, air pollution damage, water stress, salinity stress on vegetation, only to cite some main applications relevant to agronomy. Using this system it has become possible to get a 'picture' of our thermal environment.

  17. Airborne remote sensing of forest biomes

    NASA Technical Reports Server (NTRS)

    Sader, Steven A.

    1987-01-01

    Airborne sensor data of forest biomes obtained using an SAR, a laser profiler, an IR MSS, and a TM simulator are presented and examined. The SAR was utilized to investigate forest canopy structures in Mississippi and Costa Rica; the IR MSS measured forest canopy temperatures in Oregon and Puerto Rico; the TM simulator was employed in a tropical forest in Puerto Rico; and the laser profiler studied forest canopy characteristics in Costa Rica. The advantages and disadvantages of airborne systems are discussed. It is noted that the airborne sensors provide measurements applicable to forest monitoring programs.

  18. Airborne microwave radiometric imaging system

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Li, Futang; Zhang, Zuyin

    1999-09-01

    A dual channel Airborne Microwave Radiometric Imaging system (AMRI) was designed and constructed for regional environment mapping. The system operates at 35GHz, which collects radiation at horizontal and vertical polarized channels. It runs at mechanical conical scanning with 45 degrees incidence angle. Two Cassegrain antennas with 1.5 degrees beamwidth scan the scene alternately and two pseudo- color images of two channels are displayed on the screen of PC in real time. Simultaneously, all parameters of flight and radiometric data are sorted in hard disk for post- processing. The sensitivity of the radiometer (Delta) T equals 0.16K. A new displaying method, unequal size element arc displaying method, is used in image displaying. Several experiments on mobile tower were carried out and the images demonstrate that the AMRI is available to work steadily and accurately.

  19. Airborne microwave radiometric imaging system

    NASA Astrophysics Data System (ADS)

    Guo, Wei; Zhang, Zuyin; Chen, Zhengwen

    1998-08-01

    A dual channel Airborne Microwave Radiometric Imaging system (AMRI) was designed and constructed for regional environment mapping. The system operates at 35GHz, which collects radiation at horizontal and vertical polarized. It runs at mechanical conical scanning with 45 degrees incidence angle. Two Cassegrain antennas with 1.5 degrees 3 dB beamwidth scan the scene alternately and two pseudo-color images of two channels are displayed on the screen of PC in real time. Simultaneously all parameters of flight and radiometric data are stored in hard disk for postprocessing. The sensitivity of the radiometers of flight and radiometric data are stored in hard disk for postprocessing. The sensitivity of the radiometers (Delta) T equals 0.16K. A new display method, unequal size element arc displaying method, is used in image displaying. Several experiments on mobile tower were carried out and the images demonstrate the AMRI is available to work steadily and accurately.

  20. Accumulation and quantitative estimates of airborne lead for a wild plant (Aster subulatus).

    PubMed

    Hu, Xin; Zhang, Yun; Luo, Jun; Xie, Mingjie; Wang, Tijian; Lian, Hongzhen

    2011-03-01

    Foliar uptake of airborne lead is one of the pathways for Pb accumulation in plant organs. However, the approximate contributions of airborne Pb to plant organs are still unclear. In the present study, aerosols (nine-stage size-segregated aerosols and total suspended particulates), a wild plant species (Aster subulatus) and the corresponding soils were collected and Pb contents and isotopic ratios in these samples were analyzed. Average concentration of Pb was 96.5 ± 63.5 ng m(-3) in total suspended particulates (TSP) and 20.4 ± 5.5 ng m(-3) in the fine fractions of size-segregated aerosols (SSA) (<2.1 μm), higher than that in the coarser fractions (>2.1 μm) (6.38 ± 3.71 ng m(-3)). Enrichment factors show that aerosols and soils suffered from anthropogenic inputs and the fine fractions of the size-segregated aerosols enriched more Pb than the coarse fractions. The order of Pb contents in A. subulatus was roots>leaves>stems. The linear relationship of Pb isotope ratios ((206)Pb/(207)Pb and (208)Pb/(206)Pb) among soil, plant and aerosol samples were found. Based on the simple binary Pb isotopic model using the mean (206)Pb/(207)Pb ratios in TSP and in SSA, the approximate contributions of airborne Pb into plant leaves were 72.2% and 65.1%, respectively, suggesting that airborne Pb is the most important source for the Pb accumulation in leaves. So the combination of Pb isotope tracing and the simple binary Pb isotope model can assess the contribution of airborne Pb into plant leaves and may be of interest for risk assessment of the exposure to airborne Pb contamination.

  1. Evaluation of particulate air samplers for airborne aflatoxin B1

    SciTech Connect

    Silas, J.C.; Harrison, M.A.; Carpenter, J.A.

    1986-01-01

    Five air samplers (Millipore, all-glass impinger, centrifugal, Andersen, and absorbent cotton) were evaluated for their ability to collect airborne grain particles contaminated with aflatoxin B1. Corn dust containing 100 micrograms aflatoxin B1/g was aerosolized within a containment system. Each device sampled 100 I air, thus exchanging the air in the chamber two times. Aflatoxin B1 was extracted from all sampling matrices and was detected and quantitated with thin-layer chromatography and scanning fluorodensitometry. The highest efficiency was obtained with the Millipore sampler, while the efficiencies of the centrifugal and the cotton samplers were almost identical. Efficiency of an Andersen was less, with no toxin recovered from an all-glass impinger. Measurement of particle size was accomplished with the Andersen sampler.

  2. Dynamics of airborne fungal populations in a large office building

    NASA Technical Reports Server (NTRS)

    Burge, H. A.; Pierson, D. L.; Groves, T. O.; Strawn, K. F.; Mishra, S. K.

    2000-01-01

    The increasing concern with bioaerosols in large office buildings prompted this prospective study of airborne fungal concentrations in a newly constructed building on the Gulf coast. We collected volumetric culture plate air samples on 14 occasions over the 18-month period immediately following building occupancy. On each sampling occasion, we collected duplicate samples from three sites on three floors of this six-story building, and an outdoor sample. Fungal concentrations indoors were consistently below those outdoors, and no sample clearly indicated fungal contamination in the building, although visible growth appeared in the ventilation system during the course of the study. We conclude that modern mechanically ventilated buildings prevent the intrusion of most of the outdoor fungal aerosol, and that even relatively extensive air sampling protocols may not sufficiently document the microbial status of buildings.

  3. Macrobenthos and multi-molecular markers as indicators of environmental contamination in a South American port (Mar del Plata, Southwest Atlantic).

    PubMed

    Albano, Mariano J; da Cunha Lana, Paulo; Bremec, Claudia; Elías, Rodolfo; Martins, César C; Venturini, Natalia; Muniz, Pablo; Rivero, Silvia; Vallarino, Eduardo A; Obenat, Sandra

    2013-08-15

    We evaluated benthic habitat quality along a presumed contamination gradient in the Mar del Plata port (Southwestern Atlantic) by coupling biological and chemical proxies in a multidisciplinary approach. Organic matter and photosynthetic pigment contents were higher in silty-clay bottoms of the inner port sites. Levels of all fecal steroids decreased from the inner sites to the port inlet. High concentrations of coprostanol in the inner sites seemed to derive from a permanent population of sea lions rather than from sewage outfalls due to coprostanol/epicoprostanol ratio (IV) values <2.5. PAHs levels were also higher in the inner sector, related to both biomass combustion and petroleum combustion associated to local marine traffic. High disturbance and low ecological status were reflected in low benthic diversity and high AMBI values in the inner sites.

  4. Multi-molecular markers and metals as tracers of organic matter inputs and contamination status from an Environmental Protection Area in the SW Atlantic (Laranjeiras Bay, Brazil).

    PubMed

    Martins, César C; Bícego, Marcia C; Figueira, Rubens C L; Angelli, José Lourenço F; Combi, Tatiane; Gallice, Wellington C; Mansur, Andressa V; Nardes, Emanoela; Rocha, Marília L; Wisnieski, Edna; Ceschim, Liziane M M; Ribeiro, Andreza P

    2012-02-15

    The sources and concentrations of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), faecal and biogenic sterols, and trace metals at 10 sampling sites located in Laranjeiras Bay, a large Environmental Protection Area in the southern Atlantic region of Brazil, were determined to assess the sources of organic matter and the contamination status of estuarine sediments. Organic compounds were determined by GC-FID and GC-MS, and ICP-OES was used to evaluate trace metals. The total AHs concentration ranged from 0.28 to 8.19 μg g(-1), and n-C(29) and n-C(31) alkanes were predominant, indicating significant inputs from higher terrestrial plants. Unresolved complex mixtures (UCM) were not detected at any site, suggesting that the study area was not significantly contaminated by fossil fuels. The total PAH concentration varied from 3.85 to 89.2 ng g(-1). The ratio between selected PAH isomers showed that combustion of biomass, coal, and petroleum is the main source of PAHs in the study area. The concentrations of the faecal sterols coprostanol and epicoprostanol were below the detection limits, suggesting that sewage was not a significant contributor to sedimentary organic matter. The concentrations of the trace metals (As, Cr, Cu, Ni, Pb and Zn) were low, except near sites located at the mouths of rivers that discharge into the study area and near urbanised regions (Paranaguá city and the adjoining harbour). In general, the concentrations of PAHs were below the threshold effect concentrations (TEL) levels. Although the As, Cr and Ni concentrations were above the TEL levels, the study area can be considered as preserved from human activities.

  5. Spatial patterns of atmospherically deposited organic contaminants at high elevation in the southern Sierra Nevada mountains, California, USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Airborne contaminants in the Sierra Nevada mountains of California have been implicated as a factor adversely affecting biological resources like amphibians and fish, yet the distributions of contaminants within the mountains are poorly known, particularly at high elevation. we evaluated contaminan...

  6. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect

    Glissmeyer, John A.

    2010-10-18

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  7. Airborne Gamma-Spectrometry in Switzerland

    NASA Astrophysics Data System (ADS)

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-01

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of 137Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  8. Airborne Gamma-Spectrometry in Switzerland

    SciTech Connect

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-07

    Airborne gamma-spectrometry is able to obtain fast radiological information over large areas. The airborne gamma-spectrometry unit deployed in Switzerland by the Swiss National Emergency Operations Centre (NEOC) consists of a Swiss army Super Puma helicopter equipped with four NaI-Detectors with a total volume of 17 liters, associated electronics and a real-time data evaluation and mapping unit developed by the Swiss Federal Institute of Technology (ETH) and the Paul Scherrer Institut (PSI). The operational readiness of the airborne gamma-spectrometry system is validated in annual exercises of one week duration. Data from 2005 and 2006 exercises are represented in maps of {sup 137}Cs activity concentration for two towns located in southern and western Switzerland. An indicator of man-made radioactivity (MMGC ratio) is demonstrated for an area with four different types of nuclear installations. The intercomparison between airborne gamma-spectrometry and ground measurements showed good agreement between both methods.

  9. SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH

    EPA Science Inventory

    Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (<_ 1....

  10. Toolsets for Airborne Data Web Application

    Atmospheric Science Data Center

    2014-09-17

    ... relevant issues. Features Include Select data based on mission, date and/or scientific parameter Output original data ... Details:  Toolsets for Airborne Data (TAD) Web Application Category:  Instrument Specific Search, ...

  11. Combustion aerosols formed during burning of radioactively contaminated materials: Experimental results

    SciTech Connect

    Halverson, M.A.; Ballinger, M.Y.; Dennis, G.W.

    1987-03-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of potential airborne releases. Radioactive aerosols generated by fires were investigated in experiments in which combustible solids and liquids were contaminated with radioactive materials and burned. Uranium in powder and liquid form was used to contaminate five fuel types: polychloroprene, polystyrene, polymethylmethacrylate, cellulose, and a mixture of 30% tributylphosphate (TBP) in kerosene. Heat flux, oxygen concentration, air flow, contaminant concentration, and type of ignition were varied in the experiments. The highest release (7.1 wt %) came from burning TBP/kerosene over contaminated nitric acid. Burning cellulose contaminated with uranyl nitrate hexahydrate liquid gave the lowest release (0.01 wt %). Rate of release and particle size distribution of airborne radioactive particles were highly dependent on the type of fuel burned.

  12. Shuttle payload integration - Contamination aspects

    NASA Technical Reports Server (NTRS)

    Jacobs, S.; Leger, L. J.; Ehlers, H. K. F.

    1982-01-01

    As part of the development of the Space Shuttle, a payload integration system has been established. This integration system or process encompasses several technical disciplines, one of which is concerned with the control of molecular and particulate contamination. Specific integration procedures and documentation have evolved that reflect the incorporation of payload/Space Transportation System contamination requirements and capabilities. Of the 38 payloads in the payload integration system currently, about 20% are considered sensitive to contamination in that special precautions must be taken to ensure that contamination from the Space Shuttle Orbiter does not impair payload function. Most of these payload requirements have been satisfied by the incorporation of controlled ground operations discipline and installation of a payload bay liner, which isolates the payload from the Orbiter systems. Some payloads, however, provide covers for sensitive payload instrumentation.

  13. Polarimetric sensor systems for airborne ISR

    NASA Astrophysics Data System (ADS)

    Chenault, David; Foster, Joseph; Pezzaniti, Joseph; Harchanko, John; Aycock, Todd; Clark, Alex

    2014-06-01

    Over the last decade, polarimetric imaging technologies have undergone significant advancements that have led to the development of small, low-power polarimetric cameras capable of meeting current airborne ISR mission requirements. In this paper, we describe the design and development of a compact, real-time, infrared imaging polarimeter, provide preliminary results demonstrating the enhanced contrast possible with such a system, and discuss ways in which this technology can be integrated with existing manned and unmanned airborne platforms.

  14. Long-range atmospheric transport and deposition of anthropogenic contaminants and their potential effects on terrestrial ecosystems. Book chapter

    SciTech Connect

    Moser, T.J.; Barker, J.R.; Tingey, D.T.

    1991-01-01

    Through the processes of atmospheric transport and deposition, many anthropogenic contaminants such as industrial organics, pesticides, and trace metals have become widely distributed around the globe. Due to the phenomenon of long-range atmospheric transport, even the most remote areas of the plant are not out of range of contaminants emitted from distant anthropogenic sources. Many of these airborne contaminants are toxic and persistent, can bioaccumulate, and may remain biologically harmful for long periods of time. Although airborne contaminants are considered primarily a human health problem, there is increasing concern that they may have deleterious ecological consequences. When sensitive terrestrial plants and other biota experience chronic exposure to low concentrations of airborne toxic chemicals, sublethal effects may occur, with subsequent impacts on ecosystem structure and function.

  15. Downscaling of Airborne Wind Energy Systems

    NASA Astrophysics Data System (ADS)

    Fechner, Uwe; Schmehl, Roland

    2016-09-01

    Airborne wind energy systems provide a novel solution to harvest wind energy from altitudes that cannot be reached by wind turbines with a similar nominal generator power. The use of a lightweight but strong tether in place of an expensive tower provides an additional cost advantage, next to the higher capacity factor and much lower total mass. This paper investigates the scaling effects of airborne wind energy systems. The energy yield of airborne wind energy systems, that work in pumping mode of operation is at least ten times higher than the energy yield of conventional solar systems. For airborne wind energy systems the yield is defined per square meter wing area. In this paper the dependency of the energy yield on the nominal generator power for systems in the range of 1 kW to 1 MW is investigated. For the onshore location Cabauw, The Netherlands, it is shown, that a generator of just 1.4 kW nominal power and a total system mass of less than 30 kg has the theoretical potential to harvest energy at only twice the price per kWh of large scale airborne wind energy systems. This would make airborne wind energy systems a very attractive choice for small scale remote and mobile applications as soon as the remaining challenges for commercialization are solved.

  16. Challenges and opportunities of airborne metagenomics.

    PubMed

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-05-06

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles.

  17. Challenges and Opportunities of Airborne Metagenomics

    PubMed Central

    Behzad, Hayedeh; Gojobori, Takashi; Mineta, Katsuhiko

    2015-01-01

    Recent metagenomic studies of environments, such as marine and soil, have significantly enhanced our understanding of the diverse microbial communities living in these habitats and their essential roles in sustaining vast ecosystems. The increase in the number of publications related to soil and marine metagenomics is in sharp contrast to those of air, yet airborne microbes are thought to have significant impacts on many aspects of our lives from their potential roles in atmospheric events such as cloud formation, precipitation, and atmospheric chemistry to their major impact on human health. In this review, we will discuss the current progress in airborne metagenomics, with a special focus on exploring the challenges and opportunities of undertaking such studies. The main challenges of conducting metagenomic studies of airborne microbes are as follows: 1) Low density of microorganisms in the air, 2) efficient retrieval of microorganisms from the air, 3) variability in airborne microbial community composition, 4) the lack of standardized protocols and methodologies, and 5) DNA sequencing and bioinformatics-related challenges. Overcoming these challenges could provide the groundwork for comprehensive analysis of airborne microbes and their potential impact on the atmosphere, global climate, and our health. Metagenomic studies offer a unique opportunity to examine viral and bacterial diversity in the air and monitor their spread locally or across the globe, including threats from pathogenic microorganisms. Airborne metagenomic studies could also lead to discoveries of novel genes and metabolic pathways relevant to meteorological and industrial applications, environmental bioremediation, and biogeochemical cycles. PMID:25953766

  18. Payload/orbiter contamination control requirement study

    NASA Technical Reports Server (NTRS)

    Bareiss, L. E.; Ress, E. B.

    1975-01-01

    The results of a contamination impact analysis upon the spacelab carrier and the spacelab carrier upon some of its potential payloads are presented. These results are based upon contamination computer modeling techniques developed to predict the induced environment for spacelab and to provide the basis for evaluation of the predicted environment against the current on orbit contamination control criteria as specified for payloads. Those spacelab carrier contamination sources evaluated against the stated contamination control criteria were outgassing/offgassing of the major nonmetallic thermal control coating of the spacelab carriers, spacelab core and experiment module and tunnel cabin atmosphere leakage, avionics bay vent, spacelab condensate vent, random particulate sloughing, and the return flux of the molecular content of these sources from the gas-gas interactions with the ambient orbital environment. It is indicated that the spacelab carrier can meet the intent of the contamination control criteria through incorporating known contamination control practices.

  19. Contaminant hydrogeology

    SciTech Connect

    Fetter, C.W.

    1993-01-01

    Hydrogeology is a rapidly evolving field in which new approaches and tools are being applied to solve problems. This new book fills an important niche. Fetter focuses primarily on chemical processes in the subsurface, avoiding duplication of materials that are covered in other, more classical texts. This book is an excellent follow-up to his earlier text, Applied Hydrogeology, and reviews only briefly the foundational concepts covered in the earlier textbook. Contaminant Hydrogeology is written at the graduate student level and assumes prerequisite courses in physics, chemistry, and hydrogeology. For the most part, each of the nine chapters covers a major area of concern common to applied contaminant studies. A thorough, theoretical treatment of solute transport through the vadose zone is presented, and a sample problem and a case study add unusually high value to this discussion of a topic that generally is not well understood in the practice. Topics covered include the Buckingham Flux Law, the Richards Equation, vapor-phase transport, equilibrium and nonequilibrium models of mass transport, and preferential flow paths. Nonaqueous-phase liquid migrations under both saturated and unsaturated conditions is covered for horizontal as well as vertical migration. Both light and dense nonaqueous phase liquids are presented, and Darcy's Law for two-phase flow is introduced. The strength of Contaminant Hydrogeology lies in the author's ability to translate concepts through practical experience. This book links the theoretical to the practical through example problems and case histories. It should be considered for use in graduate classes and would be a valuable reference in the library of any practicing hydrogeologist.

  20. Contamination Analyzer

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Measurement of the total organic carbon content in water is important in assessing contamination levels in high purity water for power generation, pharmaceutical production and electronics manufacture. Even trace levels of organic compounds can cause defects in manufactured products. The Sievers Model 800 Total Organic Carbon (TOC) Analyzer, based on technology developed for the Space Station, uses a strong chemical oxidizing agent and ultraviolet light to convert organic compounds in water to carbon dioxide. After ionizing the carbon dioxide, the amount of ions is determined by measuring the conductivity of the deionized water. The new technique is highly sensitive, does not require compressed gas, and maintenance is minimal.

  1. Performance Basis for Airborne Separation

    NASA Technical Reports Server (NTRS)

    Wing, David J.

    2008-01-01

    Emerging applications of Airborne Separation Assistance System (ASAS) technologies make possible new and powerful methods in Air Traffic Management (ATM) that may significantly improve the system-level performance of operations in the future ATM system. These applications typically involve the aircraft managing certain components of its Four Dimensional (4D) trajectory within the degrees of freedom defined by a set of operational constraints negotiated with the Air Navigation Service Provider. It is hypothesized that reliable individual performance by many aircraft will translate into higher total system-level performance. To actually realize this improvement, the new capabilities must be attracted to high demand and complexity regions where high ATM performance is critical. Operational approval for use in such environments will require participating aircraft to be certified to rigorous and appropriate performance standards. Currently, no formal basis exists for defining these standards. This paper provides a context for defining the performance basis for 4D-ASAS operations. The trajectory constraints to be met by the aircraft are defined, categorized, and assessed for performance requirements. A proposed extension of the existing Required Navigation Performance (RNP) construct into a dynamic standard (Dynamic RNP) is outlined. Sample data is presented from an ongoing high-fidelity batch simulation series that is characterizing the performance of an advanced 4D-ASAS application. Data of this type will contribute to the evaluation and validation of the proposed performance basis.

  2. Visualizing Airborne and Satellite Imagery

    NASA Technical Reports Server (NTRS)

    Bierwirth, Victoria A.

    2011-01-01

    Remote sensing is a process able to provide information about Earth to better understand Earth's processes and assist in monitoring Earth's resources. The Cloud Absorption Radiometer (CAR) is one remote sensing instrument dedicated to the cause of collecting data on anthropogenic influences on Earth as well as assisting scientists in understanding land-surface and atmospheric interactions. Landsat is a satellite program dedicated to collecting repetitive coverage of the continental Earth surfaces in seven regions of the electromagnetic spectrum. Combining these two aircraft and satellite remote sensing instruments will provide a detailed and comprehensive data collection able to provide influential information and improve predictions of changes in the future. This project acquired, interpreted, and created composite images from satellite data acquired from Landsat 4-5 Thematic Mapper (TM) and Landsat 7 Enhanced Thematic Mapper plus (ETM+). Landsat images were processed for areas covered by CAR during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCT AS), Cloud and Land Surface Interaction Campaign (CLASIC), Intercontinental Chemical Transport Experiment-Phase B (INTEXB), and Southern African Regional Science Initiative (SAFARI) 2000 missions. The acquisition of Landsat data will provide supplemental information to assist in visualizing and interpreting airborne and satellite imagery.

  3. Desiccant contamination research: Report on the desiccant contamination test facility

    SciTech Connect

    Pesaran, A.A.; Bingham, C.E.

    1991-07-01

    The activity in the cooling systems research involves research on high performance dehumidifiers and chillers that can operate efficiently with the variable thermal outputs and delivery temperatures associated with solar collectors. It also includes work on advanced passive cooling techniques. This report describes the work conducted to improve the durability of solid desiccant dehumidifiers by investigating the causes of degradation of desiccant materials from airborne contaminants and thermal cycling. The performance of a dehumidifier strongly depends on the physical properties and durability of the desiccant material. To make durable and reliable dehumidifiers, an understanding is needed of how and to what degree the performance of a dehumidifier is affected by desiccant degradation. This report, an account of work under Cooling Systems Research, documents the efforts to design and fabricate a test facility to investigate desiccant contamination based on industry and academia recommendations. It also discusses the experimental techniques needed for obtaining high-quality data and presents plans for next year. Researchers of the Mechanical and Industrial Technology Division performed this work at the Solar Energy Research Institute in FY 1988 for DOE's Office of Solar Heat Technologies. 7 refs., 19 figs., 1 tab.

  4. Contaminant treatment method

    DOEpatents

    Shapiro, Andrew Philip; Thornton, Roy Fred; Salvo, Joseph James

    2003-01-01

    The present invention provides a method for treating contaminated media. The method comprises introducing remediating ions consisting essentially of ferrous ions, and being peroxide-free, in the contaminated media; applying a potential difference across the contaminated media to cause the remediating ions to migrate into contact with contaminants in the contaminated media; chemically degrading contaminants in the contaminated media by contact with the remediating ions; monitoring the contaminated media for degradation products of the contaminants; and controlling the step of applying the potential difference across the contaminated media in response to the step of monitoring.

  5. Transmission of SARS and MERS coronaviruses and influenza virus in healthcare settings: the possible role of dry surface contamination.

    PubMed

    Otter, J A; Donskey, C; Yezli, S; Douthwaite, S; Goldenberg, S D; Weber, D J

    2016-03-01

    Viruses with pandemic potential including H1N1, H5N1, and H5N7 influenza viruses, and severe acute respiratory syndrome (SARS)/Middle East respiratory syndrome (MERS) coronaviruses (CoV) have emerged in recent years. SARS-CoV, MERS-CoV, and influenza virus can survive on surfaces for extended periods, sometimes up to months. Factors influencing the survival of these viruses on surfaces include: strain variation, titre, surface type, suspending medium, mode of deposition, temperature and relative humidity, and the method used to determine the viability of the virus. Environmental sampling has identified contamination in field-settings with SARS-CoV and influenza virus, although the frequent use of molecular detection methods may not necessarily represent the presence of viable virus. The importance of indirect contact transmission (involving contamination of inanimate surfaces) is uncertain compared with other transmission routes, principally direct contact transmission (independent of surface contamination), droplet, and airborne routes. However, influenza virus and SARS-CoV may be shed into the environment and be transferred from environmental surfaces to hands of patients and healthcare providers. Emerging data suggest that MERS-CoV also shares these properties. Once contaminated from the environment, hands can then initiate self-inoculation of mucous membranes of the nose, eyes or mouth. Mathematical and animal models, and intervention studies suggest that contact transmission is the most important route in some scenarios. Infection prevention and control implications include the need for hand hygiene and personal protective equipment to minimize self-contamination and to protect against inoculation of mucosal surfaces and the respiratory tract, and enhanced surface cleaning and disinfection in healthcare settings.

  6. Contamination monitoring approaches for EUV space optics

    NASA Technical Reports Server (NTRS)

    Ray, David C.; Malina, Roger F.; Welsh, Barry J.; Battel, Steven J.

    1989-01-01

    Data from contaminant-induced UV optics degradation studies and particulate models are used here to develop end-of-service-life instrument contamination requirements which are very stringent but achievable. The budget is divided into allocations for each phase of hardware processing. Optical and nonoptical hardware are monitored for particulate and molecular contamination during initial cleaning and baking, assembly, test, and calibration phases. The measured contamination levels are compared to the requirements developed for each phase to provide confidence that the required end-of-life levels will be met.

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

    NASA Technical Reports Server (NTRS)

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

    1992-01-01

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

  8. Development of an airborne hydrocarbon monitoring system based on FTIR technology

    NASA Astrophysics Data System (ADS)

    Mogan, Paul A.; Mattson, Carl B.; Schwindt, Chris J.

    1998-10-01

    The capability to monitor airborne hydrocarbon compounds is essential in order to protect sensitive optical payloads from performance degradation caused by the deposition of surface films. Commonly used hydrocarbon monitoring instrumentation such as flame ionization detectors yield no information about the source or identity of compounds they detect. The Fourier Transform IR Spectrometer (FTIR) with its inherent ability to discriminate a large number of compounds offers a tremendous advantage over other types of instrumentation. The contamination monitoring laboratory at John F. Kennedy Space Center has developed an airborne hydrocarbon monitoring system based on FTIR technology to support the AXAF payload. This system consist of a portable cart suitable for use in Class 1 Division 2 environments. This paper describes the system in detail.

  9. Contamination Effects Due to Space Environmental Interactions

    NASA Technical Reports Server (NTRS)

    Chen, Philip T.; Paquin, Krista C. (Technical Monitor)

    2001-01-01

    Molecular and particulate contaminants are commonly generated from the orbital spacecraft operations that are under the influence of the space environment. Once generated, these contaminants may attach to the surfaces of the spacecraft or may remain in the vicinity of the spacecraft. In the event these contaminants come to rest on the surfaces of the spacecraft or situated in the line-of-sight of the observation path, they will create various degrees of contamination effect which may cause undesirable effects for normal spacecraft operations, There will be circumstances in which the spacecraft may be subjected to special space environment due to operational conditions. Interactions between contaminants and special space environment may alter or greatly increase the contamination effect due to the synergistic effect. This paper will address the various types of contamination generation on orbit, the general effects of the contamination on spacecraft systems, and the typical impacts on the spacecraft operations due to the contamination effect. In addition, this paper will explain the contamination effect induced by the space environment and will discuss the intensified contamination effect resulting from the synergistic effect with the special space environment.

  10. Using a bioaerosol personal sampler in combination with real-time PCR analysis for rapid detection of airborne viruses.

    PubMed

    Pyankov, Oleg V; Agranovski, Igor E; Pyankova, Olga; Mokhonova, Ekaterina; Mokhonov, Vlad; Safatov, Alexander S; Khromykh, Alexander A

    2007-04-01

    We have recently developed a new personal sampler and demonstrated its feasibility for detection of viable airborne microorganisms including bacteria, fungi and viruses. To accelerate the time-consuming analytical procedure involving 2-5 days of biological testing, we employed a real-time PCR protocol in conjunction with the personal sampler for collection of airborne viruses. The advantage of this approach is that if the presence of a particular pathogen in the air is detected by the PCR, the remaining collecting liquid can be further analysed by more time-consuming biological methods to estimate the number of airborne infectious/live microorganisms. As sampling of bioaerosols in natural environments is likely to be associated with substantial contamination by a range of microorganisms commonly existing in an ambient air, an investigation of the specificity of detection by targeted PCR analysis is required. Here we present the results of the study on the detection of Influenza virus in the ambient air contaminated with high concentrations of bacteria and fungi using real-time PCR protocol. The combined sampling PCR detection method was found to be fully feasible for the rapid ( approximately 2.5 h) and highly specific (no cross-reactivity) identification of the labile airborne virus in the air containing elevated concentrations of other microorganisms.

  11. Basic radiological studies contamination control experiments

    SciTech Connect

    Duce, S.W.; Winberg, M.R.; Freeman, A.L.

    1989-09-01

    This report describes the results of experiments relating to contamination control performed in support of the Environmental Restoration Programs Retrieval Project. During the years 1950 to 1970 waste contaminated with plutonium and other transuranic radionuclides was disposed of in shallow land-filled pits and trenches at the Idaho National Engineering Laboratory. Due to potential for migration of radionuclides to an existing aquifer the feasibility of retrieving and repackaging the waste for placement in a final repository is being examined as part of a retrieval project. Contamination control experiments were conducted to determine expected respirable and nonrespirable plutonium contaminated dust fractions and the effectiveness of various dust suppression techniques. Three soil types were tested to determine respirable fractions: Rocky Flats Plant generic soil, Radioactive Waste Management Complex generic soil, and a 1:1 blend of the two soil types. Overall, the average respirable fraction of airborne dust was 5.4% by weight. Three contamination control techniques were studied: soil fixative sprays, misting agents, and dust suppression agents. All of the tested agents proved to be effective in reducing dust in the air. Details of product performance and recommended usage are discussed.

  12. Quick response airborne command post communications

    NASA Astrophysics Data System (ADS)

    Blaisdell, Randy L.

    1988-08-01

    National emergencies and strategic crises come in all forms and sizes ranging from natural disasters at one end of the scale up to and including global nuclear warfare at the other. Since the early 1960s the U.S. Government has spent billions of dollars fielding airborne command posts to ensure continuity of government and the command and control function during times of theater conventional, theater nuclear, and global nuclear warfare. Unfortunately, cost has prevented the extension of the airborne command post technology developed for these relatively unlikely events to the lower level, though much more likely to occur, crises such as natural disasters, terrorist acts, political insurgencies, etc. This thesis proposes the implementation of an economical airborne command post concept to address the wide variety of crises ignored by existing military airborne command posts. The system is known as the Quick Response Airborne Command Post (QRAC Post) and is based on the exclusive use of commercially owned and operated aircraft, and commercially available automated data processing and communications resources. The thesis addresses the QRAC Post concept at a systems level and is primarily intended to demonstrate how current technology can be exploited to economically achieve a national objective.

  13. Airborne Gravimetry and Downward Continuation (Invited)

    NASA Astrophysics Data System (ADS)

    Jekeli, C.; Yang, H.; Kwon, J.

    2009-12-01

    Measuring the Earth’s gravity field using airborne instrumentation is fully operational and has been widely practiced for nearly three decades since its official debut in the early 1980s (S. Hammer: “Airborne Gravity is Here!”) coinciding with the precision kinematic positioning capability of GPS. Airborne gravimetry is undertaken for both efficient geophysical exploration purposes, as well as the determination of the regional geoid to aid in the modernization of height systems. Especially for the latter application, downward continuation of the data and combination with existing terrestrial gravimetry pose theoretical as well as practical challenges, which, on the other hand, create multiple processing possibilities. Downward continuation may be approached in various ways from the viewpoint of potential theory and the boundary-value problem to using gradients either estimated locally or computed from existing models. Logistical constraints imposed by the airborne survey, instrumental noise, and the intrinsic numerical instability of downward continuation all conspire to impact the final product in terms of achievable resolution and accuracy. In this paper, we review the theory of airborne gravimetry and the methodology of downward continuation, and provide a numerical comparison of possible schemes and their impact on geoid determination.

  14. Mapping permafrost with airborne electromagnetics

    NASA Astrophysics Data System (ADS)

    Minsley, B. J.; Ball, L. B.; Bloss, B. R.; Kass, A.; Pastick, N.; Smith, B. D.; Voss, C. I.; Walsh, D. O.; Walvoord, M. A.; Wylie, B. K.

    2014-12-01

    Permafrost is a key characteristic of cold region landscapes, yet detailed assessments of how the subsurface distribution of permafrost impacts the environment, hydrologic systems, and infrastructure are lacking. Data acquired from several airborne electromagnetic (AEM) surveys in Alaska provide significant new insight into the spatial extent of permafrost over larger areas (hundreds to thousands of square kilometers) than can be mapped using ground-based geophysical methods or through drilling. We compare several AEM datasets from different areas of interior Alaska, and explore the capacity of these data to infer geologic structure, permafrost extent, and related hydrologic processes. We also assess the impact of fires on permafrost by comparing data from different burn years within similar geological environments. Ultimately, interpretations rely on understanding the relationship between electrical resistivity measured by AEM surveys and the physical properties of interest such as geology, permafrost, and unfrozen water content in the subsurface. These relationships are often ambiguous and non-unique, so additional information is useful for reducing uncertainty. Shallow (upper ~1m) permafrost and soil characteristics identified from remotely sensed imagery and field observations help to constrain and aerially extend near-surface AEM interpretations, where correlations between the AEM and remote sensing data are identified using empirical multivariate analyses. Surface nuclear magnetic resonance (sNMR) measurements quantify the contribution of unfrozen water at depth to the AEM-derived electrical resistivity models at several locations within one survey area. AEM surveys fill a critical data gap in the subsurface characterization of permafrost environments and will be valuable in future mapping and monitoring programs in cold regions.

  15. Contaminant signature at Los Alamos firing sites

    SciTech Connect

    Becker, N.; Irvine, J.

    1996-01-01

    During a dynamic weapons test, a weapons component is either explosively detonated or impacted against a target in the open air environment. This results in both the production of a wide size range of depleted uranium particles as well as particle scattering over a considerable distance away from the firing pad. The explosive detonation process which creates aerial distribution over a watershed distinguishes this contaminant transport problem from others where the source term is spatially discrete. Investigations of this contamination began in 1983 with collection of onsite soils, sediments, and rock samples to establish uranium concentrations. The samples were analyzed for total uranium to evaluate the magnitude of transport of uranium away from firing sites by airborne and surface water runoff mechanisms. This data was then used to define a firing site.

  16. Airborne space laser communication system and experiments

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  17. STS-1 mission contamination evaluation approach

    NASA Technical Reports Server (NTRS)

    Jacobs, S.; Ehlers, H.; Miller, E. R.

    1980-01-01

    The space transportation system 1 mission will be the first opportunity to assess the induced environment of the orbiter payload bay region. Two tools were developed to aid in this assessment. The shuttle payload contamination evaluation computer program was developed to provide an analytical tool for prediction of the induced molecular contamination environment of the space shuttle orbiter during its onorbit operations. An induced environment contamination monitor was constructed and tested to measure the space shuttle orbiter contamination environment inside the payload bay during ascent and descent and inside and outside the payload bay during the onorbit phase. Measurements are to be performed during the four orbital flight test series. Measurements planned for the first flight are described and predicted environmental data are discussed. The results indicate that the expected data are within the measurement range of the induced environment contamination monitor instruments evaluated, and therefore it is expected that useful contamination environmental data will be available after the first flight.

  18. Contamination from electrically conductive silicone tubing during aerosol chemical analysis

    SciTech Connect

    Yu, Yong; Alexander, M. L.; Perraud, Veronique; Bruns, Emily; Johnson, Stan; Ezell, Michael J.; Finlayson-Pitts, Barbara J.

    2009-06-01

    Electrically conductive silicone tubing is used to minimize losses in sampling lines during the analysis of airborne particle size distributions and number concentrations. We report contamination from this tubing using gas chromatography-mass spectrometry (GC-MS) of filter-collected samples as well as by particle mass spectrometry. Comparison of electrically conductive silicone and stainless steel tubing showed elevated siloxanes only for the silicone tubing. The extent of contamination increased with length of tubing to which the sample was exposed, and decreased with increasing relative humidity.

  19. Urban greenness influences airborne bacterial community composition.

    PubMed

    Mhuireach, Gwynne; Johnson, Bart R; Altrichter, Adam E; Ladau, Joshua; Meadow, James F; Pollard, Katherine S; Green, Jessica L

    2016-11-15

    Urban green space provides health benefits for city dwellers, and new evidence suggests that microorganisms associated with soil and vegetation could play a role. While airborne microorganisms are ubiquitous in urban areas, the influence of nearby vegetation on airborne microbial communities remains poorly understood. We examined airborne microbial communities in parks and parking lots in Eugene, Oregon, using high-throughput sequencing of the bacterial 16S rRNA gene on the Illumina MiSeq platform to identify bacterial taxa, and GIS to measure vegetation cover in buffer zones of different diameters. Our goal was to explore variation among highly vegetated (parks) versus non-vegetated (parking lots) urban environments. A secondary objective was to evaluate passive versus active collection methods for outdoor airborne microbial sampling. Airborne bacterial communities from five parks were different from those of five parking lots (p=0.023), although alpha diversity was similar. Direct gradient analysis showed that the proportion of vegetated area within a 50m radius of the sampling station explained 15% of the variation in bacterial community composition. A number of key taxa, including several Acidobacteriaceae were substantially more abundant in parks, while parking lots had higher relative abundance of Acetobacteraceae. Parks had greater beta diversity than parking lots, i.e. individual parks were characterized by unique bacterial signatures, whereas parking lot communities tended to be similar to each other. Although parks and parking lots were selected to form pairs of nearby sites, spatial proximity did not appear to affect compositional similarity. Our results also showed that passive and active collection methods gave comparable results, indicating the "settling dish" method is effective for outdoor airborne sampling. This work sets a foundation for understanding how urban vegetation may impact microbial communities, with potential implications for designing

  20. Shelter-In-Pace: Indoor Exposure Assessment During an Airborne Chemical, Biological, Radiological, and Nuclear (CBRN) Event

    DTIC Science & Technology

    2009-03-01

    reproduction of the Pasquill stabilities. [13] Table 2-Estimation of Pasquill Stability Classes Surface Wind Speed at 10 m (m/sec) Solar ...airborne contaminants transported by these airflows; transformed by a variety of processes including chemical and radio-chemical transformation, adsorption ...buildings in the BASE study for the American Society of Heating, Refrigerating , and Air-Conditioning Engineers, Inc. (ASHRAE) Journal states the

  1. Airborne Astronomy with a 150 micron - 400 micron Heterodyne Spectrometer

    NASA Technical Reports Server (NTRS)

    Betz, A. L.

    1995-01-01

    This report summarizes work done under NASA Grant NAG2-753 awarded to the University of Colorado. The project goal was to build a far-infrared heterodyne spectrometer for NASA's Kuiper Airborne Observatory, and to use this instrument to observe atomic and molecular spectral lines from the interstellar medium. This goal was successfully achieved. Detections of particular note have been the 370 micron line of neutral atomic carbon, the 158 micron transition of ionized carbon, many of the high-J rotational lines of CO-12 and CO-13 between J=9-8 and J=22-21, the 119 micron and 163 micron rotational lines of OH, the 219 micron ground-state rotational line of H2D(+), and the 63 microns fine structure line of neutral atomic oxygen. All of these lines were observed at spectral resolutions exceeding 1 part in 10(exp 6), thereby allowing accurate line shapes and Doppler velocities to be measured.

  2. Airborne Astronomy with a 150 microns - 400 microns Heterodyne Spectrometer

    NASA Technical Reports Server (NTRS)

    Betz, A. L.

    1995-01-01

    This report summarizes work done under NASA Grant NAG2-753 awarded to the University of Colorado. The project goal was to build a far-infrared heterodyne spectrometer for NASA's Kuiper Airborne Observatory, and to use this instrument to observe atomic and molecular spectral lines from the interstellar medium. This goal was successfully achieved. Detections of particular note have been the 370 micron line of neutral atomic carbon, the 158 micron transition of ionized carbon, many of the high-J rotational lines of CO-12 and CO-13 between J=9-8 and J=22-21, the 119 micron and 163 micron rotational lines of OH, the 219 micron ground-state rotational line of H2D(+), and the 63 micron fine structure line of neutral atomic oxygen. All of these lines were observed at spectral resolutions exceeding 1 part in 10(exp 6) thereby allowing accurate line shapes and Doppler velocities to be measured.

  3. Airborne astronomy with a 150 micrometer - 500 micrometer heterodyne spectrometer

    NASA Technical Reports Server (NTRS)

    Betz, A. L.

    1991-01-01

    This report summarizes work done under NASA Grant NAG2-254 awarded to the University of California. The project goal was to build a far-infrared heterodyne spectrometer for NASA's Kuiper Airborne Observatory (KAO), and to use this instrument to observe atomic and molecular spectral lines from the interstellar medium. This goal was successfully achieved; the spectrometer is now in routine use aboard the KAO. Detections of particular note have been the 370 micrometers line of neutral atomic carbon, the 158 micrometers transition of ionized carbon, many of the high-J rotational lines of 12CO and 13CO between J=9-8 and J=22-21, the 119 micron ground-state rotational line of OH, and the 219 micron ground-state rotational line of H2D(+). All of these lines were observed at spectral resolutions exceeding 1 part in 10(exp 6), thereby allowing accurate line shapes and Doppler velocities to be measured.

  4. Airborne Turbulence Detection System Certification Tool Set

    NASA Technical Reports Server (NTRS)

    Hamilton, David W.; Proctor, Fred H.

    2006-01-01

    A methodology and a corresponding set of simulation tools for testing and evaluating turbulence detection sensors has been presented. The tool set is available to industry and the FAA for certification of radar based airborne turbulence detection systems. The tool set consists of simulated data sets representing convectively induced turbulence, an airborne radar simulation system, hazard tables to convert the radar observable to an aircraft load, documentation, a hazard metric "truth" algorithm, and criteria for scoring the predictions. Analysis indicates that flight test data supports spatial buffers for scoring detections. Also, flight data and demonstrations with the tool set suggest the need for a magnitude buffer.

  5. National center for airborne laser mapping proposed

    NASA Astrophysics Data System (ADS)

    Carter, Bill; Shrestha, Ramesh L.; Dietrich, Bill

    Researchers from universities, U.S. government agencies, U.S. national laboratories, and private industry met in the spring to learn about the current capabilities of Airborne Laser Swath Mapping (ALSM), share their experiences in using the technology for a wide variety of research applications, outline research that would be made possible by research-grade ALSM data, and discuss the proposed operation and management of the brand new National Center for Airborne Laser Mapping (NCALM).The workshop successfully identified a community of researchers with common interests in the advancement and use of ALSM—a community which strongly supports the immediate establishment of the NCALM.

  6. Molecular secondary ion mass spectrometry: New dimensions in chemical characterization

    NASA Astrophysics Data System (ADS)

    Colton, Richard J.; Campana, Joseph E.; Kidwell, David A.; Ross, Mark M.; Wyatt, Jeffrey R.

    1985-04-01

    Secondary ion mass spectrometry (SIMS) has become a diverse tool for the study of many substances other than metals and semiconductors. This paper discusses the emission of polyatomic and molecular ions from surfaces that contain various inorganic and organic compounds including polymers and biomolecules. The mass and abundance distribution of cluster ions emitted from various solids — Van der Waals, metallic, ionic and covalent — are compared. Trends in the emission patterns are discussed in terms of a recombination or direct emission mechanism. The emission of molecular ions is also discussed with respect to the method of ionization and the various sample preparation and matrix-assisted procedures used. The matrices include various solid-state and liquid matrices such as ammonium chloride, charcoal, glycerol and gallium. Various chemical derivatization procedures have been developed to enhance the sensitivity of molecular SIMS and to detect selectively components in mixtures. The procedures are demonstrated for the low-level detection of airborne contaminants from paints, for the analysis of drugs in biological fluids, and for the sequencing of biomolecules such as peptides and sugars. The emission of characteristic fragment ions from the surfaces of polymers is also described for thick, insulating films.

  7. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  8. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  9. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  10. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  11. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  12. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  13. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  14. 14 CFR 135.175 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Airborne weather radar equipment... Aircraft and Equipment § 135.175 Airborne weather radar equipment requirements. (a) No person may operate a large, transport category aircraft in passenger-carrying operations unless approved airborne...

  15. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  16. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  17. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  18. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  19. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  20. 14 CFR 125.223 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... Equipment Requirements § 125.223 Airborne weather radar equipment requirements. (a) No person may operate an airplane governed by this part in passenger-carrying operations unless approved airborne weather...

  1. 14 CFR 121.357 - Airborne weather radar equipment requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Airborne weather radar equipment... § 121.357 Airborne weather radar equipment requirements. (a) No person may operate any transport... December 31, 1964, unless approved airborne weather radar equipment has been installed in the airplane....

  2. 76 FR 76333 - Notification for Airborne Wind Energy Systems (AWES)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-07

    ... Federal Aviation Administration 14 CFR Part 77 Notification for Airborne Wind Energy Systems (AWES) AGENCY...,'' to airborne wind energy systems (AWES). In addition, this notice requests information from airborne wind energy system developers and the public related to these systems so that the FAA...

  3. Radon induced surface contaminations in low background experiments

    SciTech Connect

    Pattavina, L.

    2013-08-08

    In neutrinoless double-beta decay and dark matter searches, one of the main issues is to increase the experimental sensitivity through careful material selection and production, minimizing the background contributions. In order to achieve the required, extremely low, counting rates, very stringent requirements must be fulfilled in terms of bulk material radiopurity. As the experimental sensitivity increases, the bulk impurities in the detector components decrease, and surface contaminations start to play an increasingly significant role In fully active detectors, like cryogenic particle detectors, surface contaminations are a critical issue (as shown by the CUORICINO experiment). {sup 222}Rn is by far the most intense source of airborne radioactivity, and if a radio-pure material is exposed to environment where the Radon concentration is not minimized, {sup 210}Pb and {sup 210}Po contaminations can occur. The mechanisms and the dynamics of Radon-induced surface contaminations are reviewed, and specific solutions to prevent and to reject the induced background are presented.

  4. Resuspension of soil as a source of airborne lead near industrial facilities and highways.

    PubMed

    Young, Thomas M; Heeraman, Deo A; Sirin, Gorkem; Ashbaugh, Lowell L

    2002-06-01

    Geologic materials are an important source of airborne particulate matter less than 10 microm aerodynamic diameter (PM10), but the contribution of contaminated soil to concentrations of Pb and other trace elements in air has not been documented. To examine the potential significance of this mechanism, surface soil samples with a range of bulk soil Pb concentrations were obtained near five industrial facilities and along roadsides and were resuspended in a specially designed laboratory chamber. The concentration of Pb and other trace elements was measured in the bulk soil, in soil size fractions, and in PM10 generated during resuspension of soils and fractions. Average yields of PM10 from dry soils ranged from 0.169 to 0.869 mg of PM10/g of soil. Yields declined approximately linearly with increasing geometric mean particle size of the bulk soil. The resulting PM10 had average Pb concentrations as high as 2283 mg/kg for samples from a secondary Pb smelter. Pb was enriched in PM10 by 5.36-88.7 times as compared with uncontaminated California soils. Total production of PM10 bound Pb from the soil samples varied between 0.012 and 1.2 mg of Pb/kg of bulk soil. During a relatively large erosion event, a contaminated site might contribute approximately 300 ng/m3 of PM10-bound Pb to air. Contribution of soil from contaminated sites to airborne element balances thus deserves consideration when constructing receptor models for source apportionment or attempting to control airborne Pb emissions.

  5. CALIOPE airborne CO{sub 2} DIAL (CACDI) system design

    SciTech Connect

    Mietz, D.; Archuleta, B.; Archuleta, J.

    1997-09-01

    Los Alamos National Laboratory is currently developing an airborne CO{sub 2} Differential Absorption Lidar (DIAL) system based on second generation technology demonstrated last summer at NTS. The CALIOPE Airborne CO{sub 2} DIAL (CACDI) system requirements have been compiled based on the mission objectives and SONDIAL model trade studies. Subsystem designs have been developed based on flow down from these system requirements, as well as experience gained from second generation ground tests and N-ABLE (Non-proliferation AirBorne Lidar Experiments) airborne experiments. This paper presents the CACDI mission objectives, system requirements, the current subsystem design, and provides an overview of the airborne experimental plan.

  6. Infrared airborne spectroradiometer survey results in the western Nevada area

    NASA Technical Reports Server (NTRS)

    Collins, W.; Chang, S. H.; Kuo, J. T.

    1982-01-01

    The Mark II airborne spectroradiometer system was flown over several geologic test sites in western Nevada. The infrared mineral absorption bands were observed and recorded for the first time using an airborne system with high spectral resolution in the 2.0 to 2.5 micron region. The data show that the hydrothermal alteration zone minerals, carbonates, and other minerals are clearly visible in the airborne survey mode. The finer spectral features that distinguish the various minerals with infrared bands are also clearly visible in the airborne survey data. Using specialized computer pattern recognition methods, it is possible to identify mineralogy and map alteration zones and lithologies by airborne spectroradiometer survey techniques.

  7. Mass transport contamination study

    NASA Technical Reports Server (NTRS)

    Robertson, S. J.

    1972-01-01

    A theoretical analysis was performed to determine the effects of outgassing and waste dumping on the contamination field around an orbiting spacecraft. The spacecraft was assumed to be spherical in shape with the mass flow emitting uniformly from the spherical surface at a constant rate and in a D'Lambertian spatial distribution. The outflow of gases were assumed to be neutrally charged and of a single species with a molecular weight characteristic of a composite of the actual species involved in the mass flow. The theoretical analysis showed that, for outgassing only, less than 1.5 percent of the outgas products will return to the Skylab spacecraft as a result of intermolecular collisions. When the total mass flow from the spacecraft, including waste dumps and reaction control motor firings, was considered, it was estimated that about 30 percent will return to the spacecraft.

  8. Data Analysis of Airborne Electromagnetic Bathymetry.

    DTIC Science & Technology

    1985-04-01

    ploration Method. CIMM Bulletin, May, pp. 1-12. terpretation of Airborne Electromagnetic Data. Turnross, J., H. F. Morrison, and A. Becker (1984...System. CIMM Bulletin, v. 66, pp. 104-109. Fraser. D. C. (1978). Resistivity Mapping with an Air- report, Office of Naval Research, Washington, DC

  9. Tandem mass spectrometry of individual airborne microparticles

    SciTech Connect

    Reilly, P.T.A.; Gieray, R.A.; Yang, M.; Whitten, W.B.; Ramsey, J.M.

    1997-01-01

    An apparatus for real-time MS/MS analysis of individual airborne microparticles by laser ablation in an ion trap is described. The performance has been demonstrated by the detection of tributyl phosphate and bis(2-ethylhexyl) phosphate on silicon carbide and kaolin microparticles. 28 refs., 5 figs.

  10. Airborne Satcom Terminal Research at NASA Glenn

    NASA Technical Reports Server (NTRS)

    Hoder, Doug; Zakrajsek, Robert

    2002-01-01

    NASA Glenn has constructed an airborne Ku-band satellite terminal, which provides wideband full-duplex ground-aircraft communications. The terminal makes use of novel electronically-steered phased array antennas and provides IP connectivity to and from the ground. The satcom terminal communications equipment may be easily changed whenever a new configuration is required, enhancing the terminal's versatility.

  11. Temporal variability in airborne pollen concentrations.

    PubMed

    Raynor, G S; Hayes, J V; Ogden, E C

    1976-06-01

    Tests were conducted to determine the relationship between concentrations of airborne pollens and sampling time, using sequential rotoslide samplers at urban and rural locations. Short-period data showed an increase in variability with time between samples. Two-hour data showed a stronger trend for the first 12 hours but better agreement as the time between samples approached one day.

  12. A Technique for Airborne Aerobiological Sampling

    ERIC Educational Resources Information Center

    Mill, R. A.; And Others

    1972-01-01

    Report of a study of airborne micro-organisms collected over the Oklahoma City Metropolitan area and immediate environments, to investigate the possibility that a cloud of such organisms might account for the prevalence of some respiratory diseases in and around urban areas. (LK)

  13. Airborne Forcible Entry Operations: USAF Airlift Requirements

    DTIC Science & Technology

    1994-06-03

    34Urgent Fury." U.S. military forces would land in Grenada at 5:00 A.M. on 25 October 1983. 35 Admiral Wesley MacDonald, C~ munder -in-CMief, Atlantic...The airdrop of the 82nd Airborne Division troopers at Torri- jos/Tocwmen Airport, although successful, encountered sae problems. Bad weather in the U.S

  14. Tropospheric Emission Spectrometer and Airborne Emission Spectrometer

    NASA Technical Reports Server (NTRS)

    Glavich, T.; Beer, R.

    1996-01-01

    The Tropospheric Emission Spectrometer (TES) is an instrument being developed for the NASA Earth Observing System Chemistry Platform. TES will measure the distribution of ozone and its precursors in the lower atmosphere. The Airborne Emission Spectrometer (AES) is an aircraft precursor to TES. Applicable descriptions are given of instrument design, technology challenges, implementation and operations for both.

  15. AN AIRBORNE COLLISION-WARNING DEVICE,

    DTIC Science & Technology

    A simplified airborne collision- warning device is suggested in which each aircraft transmits its barometric altitude by radio. The likelihood of...signals into ’near’ and ’far’ categories would have to be determined by flight tests, it is felt that the low cost and early availability of the system justifies its consideration. (Author)

  16. Mapping Waterhyacinth Infestations Using Airborne Hyperspectral Imagery

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Waterhyacinth [Eichhornia crassipes (Mart.) Solms] is an exotic aquatic weed that often invades and clogs waterways in many tropical and subtropical regions of the world. The objective of this study was to evaluate airborne hyperspectral imagery and different image classification techniques for mapp...

  17. Contamination Effects on EUV Optics

    NASA Technical Reports Server (NTRS)

    Tveekrem, J.

    1999-01-01

    During ground-based assembly and upon exposure to the space environment, optical surfaces accumulate both particles and molecular condensibles, inevitably resulting in degradation of optical instrument performance. Currently, this performance degradation (and the resulting end-of-life instrument performance) cannot be predicted with sufficient accuracy using existing software tools. Optical design codes exist to calculate instrument performance, but these codes generally assume uncontaminated optical surfaces. Contamination models exist which predict approximate end-of-life contamination levels, but the optical effects of these contamination levels can not be quantified without detailed information about the optical constants and scattering properties of the contaminant. The problem is particularly pronounced in the extreme ultraviolet (EUV, 300-1,200 A) and far (FUV, 1,200-2,000 A) regimes due to a lack of data and a lack of knowledge of the detailed physical and chemical processes involved. Yet it is in precisely these wavelength regimes that accurate predictions are most important, because EUV/FUV instruments are extremely sensitive to contamination.

  18. Contamination protective coatings: an overview

    NASA Astrophysics Data System (ADS)

    Pirich, Ronald

    2013-09-01

    Tailored protective coatings have the potential for tremendous technical and affordability benefits to ground, air and space systems because of their ability to reduce surface contamination, minimize icing, reduce friction, and to reduce corrosion for a wide variety of applications and missions. The thermal and radiation environment of space systems also pose unique challenges to protective coatings because of the space environment's large temperature variations, the plasma environment and solar UV and Xrays. Contamination may accumulate on sensors inhibiting accurate and timely data acquisition and their efficiency can be seriously affected by contamination buildup. For polymeric materials, not all properties are affected to the same degree by radiation but are often localized at a specific molecular bond. Both hydrophilic and hydrophobic coating approaches may be important to address specific design requirements. Hydrophilic materials are composed of polar molecules and have been used to defog glass and enable oil spots to be swept away with water. Hydrophobic molecules tend to be nonpolar and thus prefer other neutral molecules and nonpolar solvents. Hydrophobic molecules often cluster and are difficult to wet with liquids. This paper presents an overview of various types of contamination that adheres to critical air and space surfaces and potential coatings phenomenology that may be used to eliminate contamination.

  19. Metal contamination in environmental media in residential ...

    EPA Pesticide Factsheets

    Hard-rock mining for metals, such as gold, silver, copper, zinc, iron and others, is recognized to have a significant impact on the environmental media, soil and water, in particular. Toxic contaminants released from mine waste to surface water and groundwater is the primary concern, but human exposure to soil contaminants either directly, via inhalation of airborne dust particles, or indirectly, via food chain (ingestion of animal products and/or vegetables grown in contaminated areas), is also, significant. In this research, we analyzed data collected in 2007, as part of a larger environmental study performed in the Rosia Montana area in Transylvania, to provide the Romanian governmental authorities with data on the levels of metal contamination in environmental media from this historical mining area. The data were also considered in policy decision to address mining-related environmental concerns in the area. We examined soil and water data collected from residential areas near the mining sites to determine relationships among metals analyzed in these different environmental media, using the correlation procedure in SAS statistical software. Results for residential soil and water analysis indicate that the average values for arsenic (As) (85 mg/kg), cadmium (Cd) (3.2 mg/kg), mercury (Hg) (2.3 mg/kg) and lead (Pb) (92 mg/kg) exceeded the Romanian regulatory exposure levels [the intervention thresholds for residential soil in case of As (25 mg/kg) and Hg

  20. The Beginnings of Airborne Astronomy, 1920 - 1930: an Historical Narrative

    NASA Technical Reports Server (NTRS)

    Craine, E. R.

    1984-01-01

    The emergence of airborne astronomy in the early twentieth century is recounted. The aerial expedition to observe the solar eclipse on September 10, 1923, is described. Observation of the total solar eclipse of January 24, 1925, is discussed. The Honey Lake aerial expedition to study the solar eclipse of April 28, 1930, is also described. Four major accomplishments in airborne astronomy during the period 1920 to 1930 are listed. Airborne expeditions were undertaken at every logical opportunity, starting a continuous sequence of airborne astronomical expeditions which was to remain unbroken, except by World War II, to the present day. Although the scientific returns of the first ten years were modest, they did exist. Interest in, and support for, airborne astronomy was generated not only among astronomers but also among the public. Albert Stevens, arguably the true father of airborne astronomy, was to become interested in applying his considerable skill and experience to the airborne acquisition of astronomical data.

  1. Airborne laser sensors and integrated systems

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  2. Non-Seasonal Variation of Airborne Aspergillus Spore Concentration in a Hospital Building

    PubMed Central

    Oberle, Michael; Reichmuth, Markus; Laffer, Reto; Ottiger, Cornelia; Fankhauser, Hans; Bregenzer, Thomas

    2015-01-01

    Nosocomial fungal infections are gaining increased attention from infectiologists. An adequate investigation into the levels of airborne Aspergillus and other fungal spores in hospital settings, under normal conditions, is largely unknown. We monitored airborne spore contamination in a Swiss hospital building in order to establish a seasonally-dependent base-line level. Air was sampled using an impaction technique, twice weekly, at six different locations over one year. Specimens were seeded in duplicate on Sabouraud agar plates. Grown colonies were identified to genus levels. The airborne Aspergillus spore concentration was constantly low throughout the whole year, at a median level of 2 spores/m3 (inter-quartile range = IQR 1–4), and displayed no seasonal dependency. The median concentration of other fungal spores was higher and showed a distinct seasonal variability with the ambient temperature change during the different seasons: 82 spores/m3 (IQR 26–126) in summer and 9 spores/m3 (IQR 6–15) in winter. The spore concentration varied considerably between the six sampling sites in the building (10 to 26 spores/m3). This variability may explain the variability of study results in the literature. PMID:26516890

  3. Latest Advancement In Airborne Relative Gravity Instrumentation.

    NASA Astrophysics Data System (ADS)

    Brady, N.

    2011-12-01

    Airborne gravity surveying has been performed with widely varying degrees of success since early experimentation with the Lacoste and Romberg dynamic meter in the 1950s. There are a number of different survey systems currently in operation including relative gravity meters and gradiometers. Airborne gravity is ideally suited to rapid, wide coverage surveying and is not significantly more expensive in more remote and inhospitable terrain which makes airborne measurements one of the few viable options available for cost effective exploration. As improved instrumentation has become available, scientific applications have also been able to take advantage for use in determining sub surface geologic structures, for example under ice sheets in Antarctica, and more recently direct measurement of the geoid to improve the vertical datum in the United States. In 2004, Lacoste and Romberg (now Micro-g Lacoste) decided to build on their success with the newly developed AirSea II dynamic meter and use that system as the basis for a dedicated airborne gravity instrument. Advances in electronics, timing and positioning technology created the opportunity to refine both the hardware and software, and to develop a truly turnkey system that would work well for users with little or no airborne gravity experience as well as those with more extensive experience. The resulting Turnkey Airborne Gravity System (TAGS) was successfully introduced in 2007 and has since been flown in applications from oil, gas and mineral exploration surveys to regional gravity mapping and geoid mapping. The system has been mounted in a variety of airborne platforms including depending on the application of interest. The development experience with the TAGS enabled Micro-g Lacoste to embark on a new project in 2010 to completely redesign the mechanical and electronic components of the system rather than continuing incremental upgrades. Building on the capabilities of the original TAGS, the objectives for the

  4. Spacecraft contamination experience

    NASA Technical Reports Server (NTRS)

    Borson, E. N.

    1989-01-01

    Effective contamination control must encompass all aspects of ground and flight from design of the system through the end of mission life. Design systems are needed to minimize sensitivity to contamination, ease of cleaning, and contaminant production. Facilities and procedures are critical to maintaining cleanliness during ground operations. Flight operations should be planned so as to minimize contamination. More data from flights are required to assess the adequacy of designs and operations. Standards and specifications should include contamination control requirements.

  5. Space Shuttle contamination overview

    NASA Technical Reports Server (NTRS)

    Leger, L.; Jacobs, S.; Ehlers, H. K. F.

    1978-01-01

    Consideration is given to particle and gaseous contamination associated with Shuttle payload orbital delivery. An approach to control contamination is discussed which consists of analytical environment assessment, vehicle design optimization, and flight environment measurement. The analytical assessment of orbital contamination source characteristics and their effects on the Shuttle orbital environment has resulted in vehicle design changes and a detailed understanding of system operational flexibility. Verification of resulting Shuttle contamination performance will be made by the Induced Environment Contamination Monitor.

  6. Harvesting contaminants from liquid

    DOEpatents

    Simpson, John T.; Hunter, Scott R.

    2016-05-31

    Disclosed are examples of apparatuses for evaporative purification of a contaminated liquid. In each example, there is a vessel for storing the contaminated fluid. The vessel includes a surface coated with a layer of superhydrophobic material and the surface is at least partially in contact with the contaminated liquid. The contaminants do not adhere to the surface as the purified liquid evaporates, thus allowing the contaminants to be harvested.

  7. Design, calibration, and application of an airborne gamma spectrometer system in Switzerland

    SciTech Connect

    Schwarz, G.F.; Rybach, L.; Klingele, E.E.

    1997-09-01

    Airborne radiometric surveys are finding increasingly wider application in environmental mapping and monitoring. They are the most efficient tool to delimit surface contamination and to locate lost radioactive sources. To secure radiometric capability in survey and emergency situations, a new sensitive airborne system has been built that includes an airborne spectrometer with 256 channels and a sodium iodide detector with a total volume of 16.8 liters. A rack-mounted PC with memory cards is used for data acquisition, with a GPS satellite navigation system for positioning. The system was calibrated with point sources using a mathematical correction to take into account the effects of gamma-ray scattering in the ground and in the atmosphere. The calibration was complemented by high precision ground gamma spectrometry and laboratory measurements on rock samples. In Switzerland, two major research programs make use of the capabilities of airborne radiometric measurements. The first one concerns nuclear power-plant monitoring. The five Swiss nuclear installations (four power plants and one research facility) and the surrounding regions of each site are surveyed annually. The project goal is to monitor the dose-rate distribution and to provide a documented baseline database. The measurements show that all sites (with the exception of the Goesgen power plant) can be identified clearly on the maps. No artificial radioactivity that could not be explained by the Chernobyl release or earlier nuclear weapons tests was detected outside of the fenced sites of the nuclear installations. The second program aims at a better evaluation of the natural radiation level in Switzerland. The survey focused on the crystalline rocks of the Central Massifs of the Swiss Alps because of their relatively high natural radioactivity and lithological variability.

  8. Enhanced airborne radioactivity during a pine pollen release episode.

    PubMed

    Tschiersch, J; Frank, G; Roth, P; Wagenpfeil, F; Watterson, F; Watterson, J

    1999-07-01

    A single episode of pine pollen release in the highly contaminated area of Novozybkov, Russian Federation, which led to enhanced atmospheric concentrations of 137Cs is discussed. The pollen grains were sampled by a rotating arm impactor and analysed by gamma-spectrometry for 137Cs activity and by image analysis for their size. In the vicinity of a forest, a maximum concentration of 4.5+/-0.4 mBq m(-3) was measured, and a mean activity per pollen grain of 260+/-80 nBq was determined. The emission rate of the Novozybkov mixed pine forest was estimated to be approximately 400 Bq m(-2) per year. Because of the large size of pine pollen grains (about 50 microm) and the short emission period of 5-8 days per year, the estimated potential annual inhalation doses are very low. Biological emissions including pollen release may be a source of increased airborne radionuclide concentrations at larger distances from the source areas as well.

  9. Airborne drug levels in a laminar-flow hood

    SciTech Connect

    Kleinberg, M.L.; Quinn, M.J.

    1981-09-01

    The airborne levels of fluorouracil and cefazolin sodium injections after manipulation of these drug products inside a horizontal laminar-flow hood were measured. The Biotest RCS Centrifugal Air Sampler, generally used to measure microbial levels in air, was adapted with a paper filter to measure drug levels in air. In each of nine trials, five ampuls of fluorouracil were opened in the hood and transferred to empty vials. Likewise, in each of nine trials, 50 vials of cefazolin sodium 1 g were reconstituted and transferred to small-volume i.v. solutions. Drug manipulations were performed between the hood's filter and the Biotest, which was placed inside the hood. Drug collected on the filter in the Biotest was assayed with ultraviolet spectrophotometry after extraction. The range of fluorouracil collected by the Biotest was from 0 to 14 microgram, corresponding to 0-0.07 microgram/liter of sample air. Recovered cefazolin sodium ranged from 28 to 131 microgram, or 0.02-0.11 microgram/liter of sampled air. Following routine manipulation of drug products in a laminar-flow hood, the drug can contaminate, the air flowing over the product.

  10. Airborne drug levels in a laminar-flow hood.

    PubMed

    Kleinberg, M L; Quinn, M J

    1981-09-01

    The airborne levels of fluorouracil and cefazolin sodium injections after manipulation of these drug products inside a horizontal laminar-flow hood were measured. The Biotest RCS Centrifugal Air Sampler, generally used to measure microbial levels in air, was adapted with a paper filter to measure drug levels in air. In each of nine trials, five ampuls of fluorouracil were opened in the hood and transferred to empty vials. Likewise, in each of nine trials, 50 vials of cefazolin sodium 1 g were reconstituted and transferred to small-volume i.v. solutions. Drug manipulations were performed between the hood's filter and the Biotest, which was placed inside the hood. Drug collected on the filter in the Biotest was assayed with ultraviolet spectrophotometry after extraction. The range of fluorouracil collected by the Biotest was from 0 to 14 microgram, corresponding to 0-0.07 microgram/liter of sample air. Recovered cefazolin sodium ranged from 28 to 131 microgram, or 0.02-0.11 microgram/liter of sampled air. Following routine manipulation of drug products in a laminar-flow hood, the drug can contaminate, the air flowing over the product.

  11. Microwave Temperature Profiler Mounted in a Standard Airborne Research Canister

    NASA Technical Reports Server (NTRS)

    Mahoney, Michael J.; Denning, Richard F.; Fox, Jack

    2009-01-01

    Many atmospheric research aircraft use a standard canister design to mount instruments, as this significantly facilitates their electrical and mechanical integration and thereby reduces cost. Based on more than 30 years of airborne science experience with the Microwave Temperature Profiler (MTP), the MTP has been repackaged with state-of-the-art electronics and other design improvements to fly in one of these standard canisters. All of the controlling electronics are integrated on a single 4 5-in. (.10 13- cm) multi-layer PCB (printed circuit board) with surface-mount hardware. Improved circuit design, including a self-calibrating RTD (resistive temperature detector) multiplexer, was implemented in order to reduce the size and mass of the electronics while providing increased capability. A new microcontroller-based temperature controller board was designed, providing better control with fewer components. Five such boards are used to provide local control of the temperature in various areas of the instrument, improving radiometric performance. The new stepper motor has an embedded controller eliminating the need for a separate controller board. The reference target is heated to avoid possible emissivity (and hence calibration) changes due to moisture contamination in humid environments, as well as avoiding issues with ambient targets during ascent and descent. The radiometer is a double-sideband heterodyne receiver tuned sequentially to individual oxygen emission lines near 60 GHz, with the line selection and intermediate frequency bandwidths chosen to accommodate the altitude range of the aircraft and mission.

  12. Traffic in the operating room: a review of factors influencing air flow and surgical wound contamination.

    PubMed

    Pokrywka, Marian; Byers, Karin

    2013-06-01

    Surgical wound contamination leading to surgical site infection can result from disruption of the intended airflow in the operating room (OR). When personnel enter and exit the OR, or create unnecessary movement and traffic during the procedure, the intended airflow in the vicinity of the open wound becomes disrupted and does not adequately remove airborne contaminants from the sterile field. An increase in the bacterial counts of airborne microorganisms is noted during increased activity levels within the OR. Researchers have studied OR traffic and door openings as a determinant of air contamination. During a surgical procedure the door to the operating room may be open as long as 20 minutes out of each surgical hour during critical procedures involving implants. Interventions into limiting excessive movement and traffic in the OR may lead to reductions in surgical site infections in select populations.

  13. The Callaway Plant's airborne tritium sampling cart

    SciTech Connect

    Graham, C.C.; Roselius, R.R. )

    1986-07-01

    The water vapor condensation method for sampling airborne tritium offers significant advantages over other methods, including minimal sample preparation, high sensitivity, and independence from collection efficiency and sample flow rate. However, it does have disadvantages that must be overcome in the design of a sampler. This article describes a cart-mounted, portable airborne tritium sampler used at the Callaway Nuclear Plant that incorporates the advantages of the condensation technique while minimizing its shortcomings. The key elements in the design of the sampler are the use of a refrigerated bath to cool a series of three water vapor collection traps and the use of an optical condensation dew point hygrometer to measure the moisture content of the sample. Design considerations for the proper operation of dew point hygrometers are presented, and the method used to convert due point readings to water vapor content is described.

  14. Airborne Infrared Spectroscopy of 1994 Western Wildfires

    NASA Technical Reports Server (NTRS)

    Worden, Helen; Beer, Reinhard; Rinsland, Curtis P.

    1997-01-01

    In the summer of 1994 the 0.07/ cm resolution infrared Airborne Emission Spectrometer (AES) acquired spectral data over two wildfires, one in central Oregon on August 3 and the other near San Luis Obispo, California, on August 15. The spectrometer was on board a NASA DC-8 research aircraft, flying at an altitude of 12 km. The spectra from both fires clearly show features due to water vapor, carbon dioxide, carbon monoxide, ammonia, methanol, formic acid, and ethylene at significantly higher abundance and temperature than observed in downlooking spectra of normal atmospheric and ground conditions. Column densities are derived for several species, and molar ratios are compared with previous biomass fire measurements. We believe that this is the first time such data have been acquired by airborne spectral remote sensing.

  15. Airborne Wind Measurements at Cape Blanco, Oregon.

    SciTech Connect

    Lin, Jung-Tai Lin; Veenhuizen, Scott D.

    1983-12-01

    The airborne wind measuring system using a fixed wing airplane and a Loran-C navigation unit was proven to be feasible to provide the large scale background wind flow for initialization of numerical wind modeling. The rms errors in the airborne wind measuring system were +- 2 mph in wind speed and +- 12 degrees in wind direction. The advantages of this method were that wind speeds over a large area (5 miles x 14 miles, or 18 miles x 30 miles) may be determined rapidly, economically and at altitudes above the normal altitudes of TALA kite mesurements. The disadvantages were that the spatial resolution of the measurements was poor and near surface measurements were not feasible using a fixed wing aircraft. 1 reference, 10 figures, 1 table.

  16. Analyzing Options for Airborne Emergency Wireless Communications

    SciTech Connect

    Michael Schmitt; Juan Deaton; Curt Papke; Shane Cherry

    2008-03-01

    In the event of large-scale natural or manmade catastrophic events, access to reliable and enduring commercial communication systems is critical. Hurricane Katrina provided a recent example of the need to ensure communications during a national emergency. To ensure that communication demands are met during these critical times, Idaho National Laboratory (INL) under the guidance of United States Strategic Command has studied infrastructure issues, concerns, and vulnerabilities associated with an airborne wireless communications capability. Such a capability could provide emergency wireless communications until public/commercial nodes can be systematically restored. This report focuses on the airborne cellular restoration concept; analyzing basic infrastructure requirements; identifying related infrastructure issues, concerns, and vulnerabilities and offers recommended solutions.

  17. Airborne Microwave Imaging of River Velocities

    NASA Technical Reports Server (NTRS)

    Plant, William J.

    2002-01-01

    The objective of this project was to determine whether airborne microwave remote sensing systems can measure river surface currents with sufficient accuracy to make them prospective instruments with which to monitor river flow from space. The approach was to fly a coherent airborne microwave Doppler radar, developed by APL/UW, on a light airplane along several rivers in western Washington state over an extended period of time. The fundamental quantity obtained by this system to measure river currents is the mean offset of the Doppler spectrum. Since this scatter can be obtained from interferometric synthetic aperture radars (INSARs), which can be flown in space, this project provided a cost effective means for determining the suitability of spaceborne INSAR for measuring river flow.

  18. Airborne Laser/GPS Mapping of Beaches

    NASA Technical Reports Server (NTRS)

    Krabill, W. B.; Swift, R. N.; Fredrick, E. B.; Manizade, S. S.; Martin, C. F.; Sonntag, J. G.; Duffy, Mark

    1999-01-01

    Results are presented from topographic surveys of the Assateague National Seashore Park using recently developed airborne laser and Global Positioning System (GPS) technology. During November, 1995, and again in May, 1996, the NASA Arctic Ice Mapping (AIM) group from the NASA Goddard Space Flight Center's Wallops Flight Facility conducted surveys as a part of technology enhancement activities or warm-up missions prior to conducting elevation measurements of the Greenland Ice Sheet as part of NASA's Global Climate Change program. The resulting data are compared to surface surveys using standard techniques. The goal of these projects is to make these measurements to an accuracy of 10 cm. The measurements were made from NASA's 4-engine P-3 Orion aircraft using the Airborne Topographic Mapper (ATM), a scanning laser system. The necessary high accuracy vertical as well as horizontal positioning are provided by Global Positioning System (GPS) receivers located both on board the aircraft and at a fixed site at Wallops Island.

  19. Airborne infrared spectroscopy of 1994 western wildfires

    NASA Astrophysics Data System (ADS)

    Worden, Helen; Beer, Reinhard; Rinsland, Curtis P.

    1997-01-01

    In the summer of 1994 the 0.07 cm-1 resolution infrared Airborne Emission Spectrometer (AES) acquired spectral data over two wildfires, one in central Oregon on August 3 and the other near San Luis Obispo, California, on August 15. The spectrometer was on board a NASA DC-8 research aircraft, flying at an altitude of 12 km. The spectra from both fires clearly show features due to water vapor, carbon dioxide, carbon monoxide, ammonia, methanol, formic acid, and ethylene at significantly higher abundance and temperature than observed in downlooking spectra of normal atmospheric and ground conditions. Column densities are derived for several species, and molar ratios are compared with previous biomass fire measurements. We believe that this is the first time such data have been acquired by airborne spectral remote sensing.

  20. BOREAS RSS-12 Airborne Tracking Sunphotometer Measurements

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Nickeson, Jaime (Editor); Lobitz, Brad; Spanner, Michael; Wrigley, Robert

    2000-01-01

    The BOREAS RSS-12 team collected both ground and airborne sunphotometer measurements for use in characterizing the aerosol optical properties of the atmosphere during the BOREAS data collection activities. These measurements are to be used to: 1) measure the magnitude and variability of the aerosol optical depth in both time and space; 2) determine the optical properties of the boreal aerosols; and 3) atmospherically correct remotely sensed data acquired during BOREAS. This data set contains airborne tracking sunphotometer data that were acquired from the C-130 aircraft during its flights over the BOREAS study areas. The data cover selected days and times from May to September 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  1. Performance metrics for an airborne imaging system

    NASA Astrophysics Data System (ADS)

    Dayton, David C.; Gonglewski, John D.

    2004-11-01

    A series of airborne imaging experiments have been conducted on the island of Maui and at North Oscura Peak in New Mexico. Two platform altitudes were considered 3000 meters and 600 meters, both with a slant range to the target up to 10000 meters. The airborne imaging platform was a Twin Otter aircraft, which circled ground target sites. The second was a fixed platform on a mountain peak overlooking a valley 600 meters below. The experiments were performed during the day using solar illuminated target buildings. Imaging system performance predictions were calculated using standard atmospheric turbulence models, and aircraft boundary layer models. Several different measurement approaches were then used to estimate the actual system performance, and make comparisons with the calculations.

  2. Design and Development of a Scanning Airborne Direct Detection Doppler Lidar System

    NASA Technical Reports Server (NTRS)

    Gentry, Bruce; McGill, Matthew; Schwemmer, Geary; Hardesty, Michael; Brewer, Alan; Wilkerson, Thomas; Atlas, Robert; Sirota, Marcos; Lindemann, Scott

    2006-01-01

    In the fall of 2005 we began developing an airborne scanning direct detection molecular Doppler lidar. The instrument is being built as part of the Tropospheric Wind Lidar Technology Experiment (TWiLiTE), a three year project selected by the NASA Earth Sun Technology Office under the Instrument Incubator Program. The TWiLiTE project is a collaboration involving scientists and engineers from NASA Goddard Space Flight Center, NOAA ESRL, Utah State University Space Dynamics Lab, Michigan Aerospace Corporation and Sigma Space Corporation. The TWiLiTE instrument will leverage significant research and development investments made by NASA Goddard and it's partners in the past several years in key lidar technologies and sub-systems (lasers, telescopes, scanning systems, detectors and receivers) required to enable spaceborne global wind lidar measurement. These sub-systems will be integrated into a complete molecular direct detection Doppler wind lidar system designed for autonomous operation on a high altitude aircraft, such as the NASA WB57. The WB57 flies at an altitude of 18 km and from this vantage point the nadir viewing Doppler lidar will be able to profile winds through the full troposphere. The TWiLiTE integrated airborne Doppler lidar instrument will be the first demonstration of a airborne scanning direct detection Doppler lidar and will serve as a critical milestone on the path to a future spaceborne tropospheric wind system. In addition to being a technology testbed for space based tropospheric wind lidar, when completed the TWiLiTE high altitude airborne lidar will be used for studying mesoscale dynamics and storm research (e.g. winter storms, hurricanes) and could be used for calibration and validation of satellite based wind systems such as ESA's Aeolus Atmospheric Dynamics Mission. The TWiLiTE Doppler lidar will have the capability to profile winds in clear air from the aircraft altitude of 18 km to the surface with 250 m vertical resolution and < 2mls

  3. Tracking of airborne radionuclides from the damaged Fukushima Dai-ichi nuclear reactors by European networks.

    PubMed

    Masson, O; Baeza, A; Bieringer, J; Brudecki, K; Bucci, S; Cappai, M; Carvalho, F P; Connan, O; Cosma, C; Dalheimer, A; Didier, D; Depuydt, G; De Geer, L E; De Vismes, A; Gini, L; Groppi, F; Gudnason, K; Gurriaran, R; Hainz, D; Halldórsson, Ó; Hammond, D; Hanley, O; Holeý, K; Homoki, Zs; Ioannidou, A; Isajenko, K; Jankovic, M; Katzlberger, C; Kettunen, M; Kierepko, R; Kontro, R; Kwakman, P J M; Lecomte, M; Leon Vintro, L; Leppänen, A-P; Lind, B; Lujaniene, G; Mc Ginnity, P; Mc Mahon, C; Malá, H; Manenti, S; Manolopoulou, M; Mattila, A; Mauring, A; Mietelski, J W; Møller, B; Nielsen, S P; Nikolic, J; Overwater, R M W; Pálsson, S E; Papastefanou, C; Penev, I; Pham, M K; Povinec, P P; Ramebäck, H; Reis, M C; Ringer, W; Rodriguez, A; Rulík, P; Saey, P R J; Samsonov, V; Schlosser, C; Sgorbati, G; Silobritiene, B V; Söderström, C; Sogni, R; Solier, L; Sonck, M; Steinhauser, G; Steinkopff, T; Steinmann, P; Stoulos, S; Sýkora, I; Todorovic, D; Tooloutalaie, N; Tositti, L; Tschiersch, J; Ugron, A; Vagena, E; Vargas, A; Wershofen, H; Zhukova, O

    2011-09-15

    Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 ((131)I) and cesium isotopes ((137)Cs and (134)Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous (131)I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous (131)I and the large underestimation of the total (131)I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous (131)I fraction to total (131)I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the (134)Cs to (137)Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total (131)I inventory that has passed over Europe during this period was <1% of the released amount. According to the measurements, airborne activity levels remain of no concern for public health in Europe.

  4. Inventory of PCBs in Chicago and Opportunities for Reduction in Airborne Emissions and Human Exposure.

    PubMed

    Shanahan, Caitlin E; Spak, Scott N; Martinez, Andres; Hornbuckle, Keri C

    2015-12-01

    Urban areas are important regional sources of airborne polychlorinated biphenyls (PCBs) and population-scale airborne exposure, yet a comprehensive bottom-up source inventory of PCB emissions has never been quantified at urban scales in the United States. Here we report a comprehensive parcel level inventory of PCB stocks and emissions for Chicago, Illinois, developed with a transferable method from publicly available data. Chicago's legacy stocks hold 276 ± 147 tonnes ∑PCBs, with 0.2 tonnes added annually. Transformers and building sealants represent the largest legacy categories at 250 and 20 tonnes, respectively. From these stocks, annual emissions rates of 203 kg for ∑PCBs and 3 kg for PCB 11 explain observed concentrations in Chicago air. Sewage sludge drying contributes 25% to emissions, soils 31%, and transformers 21%. Known contaminated sites account for <1% of stocks and 17% of emissions to air. Paint is responsible for 0.00001% of stocks but up to 7% of ∑PCBs emissions. Stocks and emissions are highly concentrated and not correlated with population density or demographics at the neighborhood scale. Results suggest that strategies to further reduce exposure and ecosystem deposition must focus on the largest emissions sources rather than the most contaminated sites or the largest closed source legacy stocks.

  5. A new method to measure air-borne pyrogens based on human whole blood cytokine response.

    PubMed

    Kindinger, Ilona; Daneshian, Mardas; Baur, Hans; Gabrio, Thomas; Hofmann, Andreas; Fennrich, Stefan; von Aulock, Sonja; Hartung, Thomas

    2005-03-01

    Air-borne microorganisms, as well as their fragments and components, are increasingly recognized to be associated with pulmonary diseases, e.g. organic dust toxic syndrome, humidifier lung, building-related illness, "Monday sickness." We have previously described and validated a new method for the detection of pyrogenic (fever-inducing) microbial contaminations in injectable drugs, based on the inflammatory reaction of human blood to pyrogens. We have now adapted this test to evaluate the total inflammatory capacity of air samples. Air was drawn onto PTFE membrane filters, which were incubated with human whole blood from healthy volunteers inside the collection device. Cytokine release was measured by ELISA. The test detects endotoxins and non-endotoxins, such as fungal spores, Gram-positive bacteria and their lipoteichoic acid moiety and pyrogenic dust particles with high sensitivity, thus reflecting the total inflammatory capacity of a sample. When air from different surroundings such as working environments and animal housing was assayed, the method yielded reproducible data which correlated with other parameters of microbial burden tested. We further developed a standard material for quantification and showed that this assay can be performed with cryopreserved as well as fresh blood. The method offers a test to measure the integral inflammatory capacity of air-borne microbial contaminations relevant to humans. It could thus be employed to assess air quality in different living and work environments.

  6. [The importance of the airborne microorganisms evaluation in the operating rooms: the biological risk for health care workers].

    PubMed

    Gioffrè, A; Dragone, M; Ammoscato, I; Iannò, A; Marramao, A; Samele, P; Sorrentino, D

    2007-01-01

    The operating room is a complex environment, traditionally considered at high infectious risk, for both the patients and the health care workers, they can contract diseases, because of the exposure for relatively long times to various dangerous chemical, physical and biological factors. The biological contamination in the operating rooms is mostly imputable to airborne and bloodborne microorganisms, whose primary source represent the staff: patients and operating team, while either secondary sources are the contaminate air introduced from the VCCC system and the use of the infect instruments. About 10% of the hospital infections are determined by airborne bacteria and a variable fraction of these, not only in immunocompromised patients but also in healthy people, may cause the respirators pathologies. The aim of this paper was to estimate the microbial contamination, in 20 hospitals located in three regions of the South Italy, for a total 81 operating rooms. The results show that 17 of the 20 operating units and 45 out of 81 operating rooms examined are contaminated. Periodic inspections should be carried out in order to control and lower the biological risk for both the patients and the health care workers.

  7. Airborne Chemical Sensing with Mobile Robots

    PubMed Central

    Lilienthal, Achim J.; Loutfi, Amy; Duckett, Tom

    2006-01-01

    Airborne chemical sensing with mobile robots has been an active research area since the beginning of the 1990s. This article presents a review of research work in this field, including gas distribution mapping, trail guidance, and the different subtasks of gas source localisation. Due to the difficulty of modelling gas distribution in a real world environment with currently available simulation techniques, we focus largely on experimental work and do not consider publications that are purely based on simulations.

  8. A new tool for sampling airborne isocyanates

    SciTech Connect

    Sesana, G.; Nano, G.; Baj, A. )

    1991-05-01

    A new sampling system is presented that uses solid sorbent media contained in a tube for the determination of airborne isocyanates (2.4-2.6 toluene diisocyanate, hexamethylene diisocyanate, and 4.4' diaminodiphenylmethane diisocyanate). The method is compared with the National Institute for Occupational Safety and Health (NIOSH) Method P CAM 5505 (Revision {number sign}1). Experimental tests yielded results that were highly concordant with the NIOSH method.

  9. Airborne Nanostructured Particles and Occupational Health

    NASA Astrophysics Data System (ADS)

    Maynard, Andrew D.; Kuempel, Eileen D.

    2005-12-01

    Nanotechnology is leading to the development in many field, of new materials and devices in many fields that demonstrate nanostructure-dependent properties. However, concern has been expressed that these same properties may present unique challenges to addressing potential health impact. Airborne particles associated with engineered nanomaterials are of particular concern, as they can readily enter the body through inhalation. Research into the potential occupational health risks associated with inhaling engineered nanostructured particles is just beginning. However, there is a large body of data on occupational and environmental aerosols, which is applicable to developing an initial assessment of potential risk and risk reduction strategies. Epidemiological and pathological studies of occupational and environmental exposures to airborne particles and fibers provide information on the aerosol-related lung diseases and conditions that have been observed in humans. Toxicological studies provide information on the specific disease mechanisms, dose-response relationships, and the particle characteristics that influence toxicity, including the size, surface area, chemistry or reactivity, solubility, and shape. Potential health risk will depend on the magnitude and nature of exposures to airborne nanostructured particles, and on the release, dispersion, transformation and control of materials in the workplace. Aerosol control methods have not been well-characterized for nanometer diameter particles, although theory and limited experimental data indicate that conventional ventilation, engineering control and filtration approaches should be applicable in many situations. Current information supports the development of preliminary guiding principles on working with engineered nanomaterials. However critical research questions remain to be answered before the potential health risk of airborne nanostructured particles in the workplace can be fully addressed.

  10. Holographic Airborne Rotating Lidar Instrument Experiment (HARLIE)

    NASA Technical Reports Server (NTRS)

    Schwemmer, Geary K.

    1998-01-01

    Scanning holographic lidar receivers are currently in use in two operational lidar systems, PHASERS (Prototype Holographic Atmospheric Scanner for Environmental Remote Sensing) and now HARLIE (Holographic Airborne Rotating Lidar Instrument Experiment). These systems are based on volume phase holograms made in dichromated gelatin (DCG) sandwiched between 2 layers of high quality float glass. They have demonstrated the practical application of this technology to compact scanning lidar systems at 532 and 1064 nm wavelengths, the ability to withstand moderately high laser power and energy loading, sufficient optical quality for most direct detection systems, overall efficiencies rivaling conventional receivers, and the stability to last several years under typical lidar system environments. Their size and weight are approximately half of similar performing scanning systems using reflective optics. The cost of holographic systems will eventually be lower than the reflective optical systems depending on their degree of commercialization. There are a number of applications that require or can greatly benefit from a scanning capability. Several of these are airborne systems, which either use focal plane scanning, as in the Laser Vegetation Imaging System or use primary aperture scanning, as in the Airborne Oceanographic Lidar or the Large Aperture Scanning Airborne Lidar. The latter class requires a large clear aperture opening or window in the aircraft. This type of system can greatly benefit from the use of scanning transmission holograms of the HARLIE type because the clear aperture required is only about 25% larger than the collecting aperture as opposed to 200-300% larger for scan angles of 45 degrees off nadir.

  11. Image Based Synthesis for Airborne Minefield Data

    DTIC Science & Technology

    2005-12-01

    applications of image synthesis include artificial texture generation [1], image repairing [2], photometric image rendering [3] and ultrasound imaging...1999. 4. M. Song, R. M. Haralick, F.H. Sheehan, " Ultrasound imaging simulation and echocardiographic image synthesis ", Proceedings of the IEEE...Night Vision and Electronic Sensors Directorate AMSRD-CER-NV-TR-246I Image Based Synthesis for Airborne Minefield Data December 2005 Approved for

  12. DC-8 Airborne Laboratory in flight

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This 17-second clip shows air-to-air shots of the NASA DC-8 airborne laboratory as it passes over the NASA Dryden Flight Research Center at Edwards, California, and the foothills of the Sierra Nevada mountains. On December 29, 1997, NASA Dryden Flight Research Center, Edwards, California, received a DC-8 airborne laboratory from NASA Ames Research Center, Moffett Field, California, where it had flown missions related to airborne science and earth science for many years. This airplane has continued to be used from Dryden for basic research about the Earth's surface and atmosphere as well as sensor development and satellite sensor verification. In mid-February 1998, the DC-8 resumed flying its medium-altitude, science-gathering missions following maintenance and upgrades of its satellite communications system. It flew a variety of missions over widely scattered geographic regions during the rest of the calendar year and beyond to gather data about earth science, including weather and climate. Built by Douglas Aircraft Company, Long Beach, California, in 1966, the DC-8 flew for 20 years with two major airlines before being acquired by NASA and converted to its present role as an airborne laboratory. The four-engine former jetliner was capable of flying extended-duration missions as long as 12 hours over a range of 5,400 nautical miles at cruise altitudes up to 41,000 feet. It was also capable of carrying a payload of multiple experiments weighing up to 30,000 pounds. On some of its missions, up to 30 scientists have worked on as many as 14 different experiments.

  13. DC-8 airborne laboratory in flight

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In this 26-second clip the NASA DC-8 airborne laboratory is shown making turns over the Sierra Nevada foothills, NASA Dryden Flight Research Center, and Rogers Dry Lakebed at Edwards Air Force Base, California. On December 29, 1997, NASA Dryden Flight Research Center, Edwards, California, received a DC-8 airborne laboratory from NASA Ames Research Center, Moffett Field, California, where it had flown missions related to airborne science and earth science for many years. This airplane has continued to be used from Dryden for basic research about the Earth's surface and atmosphere as well as sensor development and satellite sensor verification. In mid-February 1998, the DC-8 resumed flying its medium-altitude, science-gathering missions following maintenance and upgrades of its satellite communications system. It flew a variety of missions over widely scattered geographic regions during the rest of the calendar year and beyond to gather data about earth science, including weather and climate. Built by Douglas Aircraft Company, Long Beach, California, in 1966, the DC-8 flew for 20 years with two major Airlines before being acquired by NASA and converted to its present role as an airborne laboratory. The four-engine former jetliner was capable of flying extended-duration missions for as long as 12 hours over a range of 5,400 nautical miles at cruise altitudes of up to 41,000 feet. It was also capable of carrying a payload of multiple experiments weighing up to 30,000 pounds. On some of its missions, up to 30 scientists have worked on as many as 14 different experiments.

  14. Performance Testing of a Russian Mir Space Station Trace Contaminant Control Assembly

    NASA Technical Reports Server (NTRS)

    Curtis, R. E.; Perry, J. L.; Abramov, L. H.

    1997-01-01

    A filter assembly which is incorporated into the Russian Trace Contaminant Control Assembly was tested for removal of airborne trace chemical contaminants in a closed loop 9 m(exp 3) system. Given contaminant loading rates and maximum allowable atmospheric concentrations, the Russian system was able to maintain system air concentrations below maximum allowable limits. This was achieved for both a new filter system and for a system where a part of it was pre-loaded to emulate 3 years of system age.

  15. Airborne Tactical Free-Electron Laser

    SciTech Connect

    Whitney, Roy; Neil, George

    2007-02-01

    The goal of 100 kilowatts (kW) of directed energy from an airborne tactical platform has proved challenging due to the size and weight of most of the options that have been considered. However, recent advances in Free-Electron Lasers appear to offer a solution along with significant tactical advantages: a nearly unlimited magazine, time structures for periods from milliseconds to hours, radar like functionality, and the choice of the wavelength of light that best meets mission requirements. For an Airborne Tactical Free-Electron Laser (ATFEL) on a platforms such as a Lockheed C-130J-30 and airships, the two most challenging requirements, weight and size, can be met by generating the light at a higher harmonic, aggressively managing magnet weights, managing cryogenic heat loads using recent SRF R&D results, and using FEL super compact design concepts that greatly reduce the number of components. The initial R&D roadmap for achieving an ATFEL is provided in this paper. Performing this R&D is expected to further reduce the weight, size and power requirements for the FELs the Navy is currently developing for shipboard applications, as well as providing performance enhancements for the strategic airborne MW class FELs. The 100 kW ATFEL with its tactical advantages may prove sufficiently attractive for early advancement in the queue of deployed FELs.

  16. Improved Airborne System for Sensing Wildfires

    NASA Technical Reports Server (NTRS)

    McKeown, Donald; Richardson, Michael

    2008-01-01

    The Wildfire Airborne Sensing Program (WASP) is engaged in a continuing effort to develop an improved airborne instrumentation system for sensing wildfires. The system could also be used for other aerial-imaging applications, including mapping and military surveillance. Unlike prior airborne fire-detection instrumentation systems, the WASP system would not be based on custom-made multispectral line scanners and associated custom- made complex optomechanical servomechanisms, sensors, readout circuitry, and packaging. Instead, the WASP system would be based on commercial off-the-shelf (COTS) equipment that would include (1) three or four electronic cameras (one for each of three or four wavelength bands) instead of a multispectral line scanner; (2) all associated drive and readout electronics; (3) a camera-pointing gimbal; (4) an inertial measurement unit (IMU) and a Global Positioning System (GPS) receiver for measuring the position, velocity, and orientation of the aircraft; and (5) a data-acquisition subsystem. It would be necessary to custom-develop an integrated sensor optical-bench assembly, a sensor-management subsystem, and software. The use of mostly COTS equipment is intended to reduce development time and cost, relative to those of prior systems.

  17. Airborne SAR imagery to support hydraulic models

    NASA Astrophysics Data System (ADS)

    Castiglioni, S.

    2009-04-01

    Satellite images and airborne SAR (Synthetic Aperture Radar) imagery are increasingly widespread and they are effective tools for measuring the size of flood events and for assessment of damage. The Hurricane Katrina disaster and the tsunami catastrophe in Indian Ocean countries are two recent and sadly famous examples. Moreover, as well known, the inundation maps can be used as tools to calibrate and validate hydraulic model (e.g. Horritt et al., Hydrological Processes, 2007). We carry out an application of a 1D hydraulic model coupled with a high resolution DTM for predicting the flood inundation processes. The study area is a 16 km reach of the River Severn, in west-central England, for which, four maps of inundated areas, obtained through airborne SAR images, and hydrometric data are available. The inundation maps are used for the calibration/validation of a 1D hydraulic model through a comparison between airborne SAR images and the results of hydraulic simulations. The results confirm the usefulness of inundation maps as hydraulic modelling tools and, moreover, show that 1D hydraulic model can be effectively used when coupled with high resolution topographic information.

  18. Cryospheric Applications of Modern Airborne Photogrammetry

    NASA Astrophysics Data System (ADS)

    Nolan, M.

    2014-12-01

    Airborne photogrammetry is undergoing a renaissance. Lower-cost equipment, more powerful software, and simplified methods have lowered the barriers-to-entry significantly and now allow repeat-mapping of cryospheric dynamics that were previously too expensive to consider. The current state-of-the-art is the ability to use an airborne equipment package costing less than $20,000 to make topographic maps on landscape-scales at 10 cm pixel size with a vertical repeatability of about 10 cm. Nearly any surface change on the order of decimeters can be measured using these techniques through analysis of time-series of such maps. This presentation will discuss these new methods and their application to cryospheric dynamics such as the measurement of snow depth, coastal erosion, valley-glacier volume-change, permafrost thaw, frost heave of infrastructure, river bed geomorphology, and aufeis melt. Because of the expense of other airborne methods, by necessity measurements of these dynamics are currently most often made on the ground along benchmark transects that are then extrapolated to the broader scale. The ability to directly measure entire landscapes with equal or higher accuracy than transects eliminates the need to extrapolate them and the ability to do so at lower costs than transects may revolutionize the way we approach studying change in the cryosphere, as well as our understanding of the cryosphere itself.

  19. Optical Communications Link to Airborne Transceiver

    NASA Technical Reports Server (NTRS)

    Regehr, Martin W.; Kovalik, Joseph M.; Biswas, Abhijit

    2011-01-01

    An optical link from Earth to an aircraft demonstrates the ability to establish a link from a ground platform to a transceiver moving overhead. An airplane has a challenging disturbance environment including airframe vibrations and occasional abrupt changes in attitude during flight. These disturbances make it difficult to maintain pointing lock in an optical transceiver in an airplane. Acquisition can also be challenging. In the case of the aircraft link, the ground station initially has no precise knowledge of the aircraft s location. An airborne pointing system has been designed, built, and demonstrated using direct-drive brushless DC motors for passive isolation of pointing disturbances and for high-bandwidth control feedback. The airborne transceiver uses a GPS-INS system to determine the aircraft s position and attitude, and to then illuminate the ground station initially for acquisition. The ground transceiver participates in link-pointing acquisition by first using a wide-field camera to detect initial illumination from the airborne beacon, and to perform coarse pointing. It then transfers control to a high-precision pointing detector. Using this scheme, live video was successfully streamed from the ground to the aircraft at 270 Mb/s while simultaneously downlinking a 50 kb/s data stream from the aircraft to the ground.

  20. Airborne multispectral detection of regrowth cotton fields

    NASA Astrophysics Data System (ADS)

    Westbrook, John K.; Suh, Charles P.-C.; Yang, Chenghai; Lan, Yubin; Eyster, Ritchie S.

    2015-01-01

    Effective methods are needed for timely areawide detection of regrowth cotton plants because boll weevils (a quarantine pest) can feed and reproduce on these plants beyond the cotton production season. Airborne multispectral images of regrowth cotton plots were acquired on several dates after three shredding (i.e., stalk destruction) dates. Linear spectral unmixing (LSU) classification was applied to high-resolution airborne multispectral images of regrowth cotton plots to estimate the minimum detectable size and subsequent growth of plants. We found that regrowth cotton fields can be identified when the mean plant width is ˜0.2 m for an image resolution of 0.1 m. LSU estimates of canopy cover of regrowth cotton plots correlated well (r2=0.81) with the ratio of mean plant width to row spacing, a surrogate measure of plant canopy cover. The height and width of regrowth plants were both well correlated (r2=0.94) with accumulated degree-days after shredding. The results will help boll weevil eradication program managers use airborne multispectral images to detect and monitor the regrowth of cotton plants after stalk destruction, and identify fields that may require further inspection and mitigation of boll weevil infestations.

  1. ICESat-2 Simulated Data from Airborne Altimetery

    NASA Technical Reports Server (NTRS)

    Brunt, Kelly M.; Neumann, T. A.; Markus, T.; Brenner, A. C.; Barbieri, K. A.; Field, C. T.; Sirota, J. M.

    2010-01-01

    Ice, Cloud, and land Elevation Satellite-2 (ICESat-2) is scheduled to launch in 2015 and will carry onboard the Advanced Topographic Laser Altimeter System (ATLAS), which represents a new approach to spaceborne determination of surface elevations. Specifically, the current ATLAS design is for a micropulse, multibeam, photon-counting laser altimeter with lower energy, a shorter pulse width, and a higher repetition rate relative to the Geoscience Laser Altimeter (GLAS), the instrument that was onboard ICESat. Given the new and untested technology associated with ATLAS, airborne altimetry data is necessary (1) to test the proposed ATLAS instrument geometry, (2) to validate instrument models, and (3) to assess the atmospheric effects on multibeam altimeters. We present an overview of the airborne instruments and datasets intended to address the ATLAS instrument concept, including data collected over Greenland (July 2009) using an airborne SBIR prototype 100 channel, photon-counting, terrain mapping altimeter, which addresses the first of these 3 scientific concerns. Additionally, we present the plan for further simulator data collection over vegetated and ice covered regions using Multiple Altimeter Beam Experimental Lidar (MABEL), intended to address the latter two scientific concerns. As the ICESAT-2 project is in the design phase, the particular configuration of the ATLAS instrument may change. However, we expect this work to be relevant as long as ATLAS pursues a photon-counting approach.

  2. Emergency communications via airborne communications node

    NASA Astrophysics Data System (ADS)

    Niessen, Charles W.

    1997-02-01

    Natural disasters such as floods, hurricanes, and earthquakes invariably result in disruption of the commercial communications infrastructure and can severely impede the delivery of emergency services by local and federal agencies. In addition, the public's inability to communicate with commercial service providers can substantially slow the recovery process. Since wide-spread destruction of communications plant and distribution systems takes a long time to rebuild, an attractive alternative would be to provide communications connectivity through an airborne platform configured as a communication node. From a high altitude, a single aircraft could provide line of sight connectivity between users that are not within line of sight of each other, and could relay communications through ground or satellite gateways to the national PSTN. This capability could be used to substitute for multiple base stations for fire and police as well as military relief workers using their normal mobile communications gear. The airborne platform could also serve as a wide area base station to replace cellular phone towers that have been destroyed; this would enable civilian access to communications services from existing cellular phones, but could also be used by relief workers carrying low-cost commercial handsets. This paper examines the technical methods for achieving these goals, identifies the equipment needed on the airborne platform, and discusses the performance that could be expected.

  3. Airborne Infrared Spectrograph for Eclipse Observations

    NASA Astrophysics Data System (ADS)

    Golub, L.; Cheimets, P.; DeLuca, E. E.; Samra, J.; Judge, P. G.

    2015-12-01

    Direct measurements of the coronal magnetic field have significant potential to enhance our understanding of coronal dynamics, and improve forecasting models. Of particular interest are observations of coronal field lines in the Transition Corona, the transitional region between closed and open flux systems, providing important information on eruptive instabilities and on the origin of the slow solar wind. While current instruments routinely observe the photospheric and chromospheric magnetic fields, the proposed airborne spectrometer will take a step toward the direct observation of coronal fields by measuring plasma emission in the infrared at high spatial and spectral resolution. The targeted lines are five forbidden magnetic dipole transitions between 1.4 and 4 um. The airborne system will consist of a telescope, grating spectrometer and pointing/stabilization system to be flown on the NSF/NCAR High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) during the 21 August 2017 total solar eclipse. We will discuss the scientific objectives of the 2017 flight, describe details of the instrument design, and present the observing program for the eclipse.

  4. Shuttle/spacelab contamination environment and effects handbook

    NASA Technical Reports Server (NTRS)

    Bareiss, L. E.; Payton, R. M.; Papazian, H. A.

    1986-01-01

    This handbook is intended to assist users of the Spacelab/Space Transportation System by providing contamination environments and effects information that may be of value in planning, designing, manufacturing, and operating a space flight experiment. A summary of available molecular and particulate contamination data on the Space Transportation System and its facilities is presented. Contamination models, contamination effects, and protection methods information are also presented. In addition to contamination, the effects of the space environments at STS altitudes on spacecraft materials are included. Extensive references, bibliographies, and contacts are provided.

  5. Results of airborne measurements in the plume near and far from the 2014 Bardarbunga-Holuhraun eruption.

    NASA Astrophysics Data System (ADS)

    Arnason, Gylfi; Eliasson, Jonas; Weber, Konradin; Boehlke, Christoph; Palsson, Thorgeir; Rognvaldsson, Olafur; Thorsteinsson, Throstur; Platt, Ulrich; Tirpitz, Lukas; Jones, Roderic L.; Smith, Paul D.

    2015-04-01

    The Volcanic Ash Research (VAR) group is focused on airborne measurement of ash contamination to support safe air travel. In relations to the recent eruption, the group measured ash and several gaseous species in the plume 10-300 km from the volcano. The eruption emitted ash turned out to be mostly in the fine aerosol range (much less than 10 micrometers in diameter). Our highest measured concentrations were lower than 1 mg/m3 indicating that commercial air traffic was not threatened (greater than 2 mg/m3) by the ash contamination. But we measured sulfur dioxide (SO2 ) up to 90 mg/m3, which presented a potentially dangerous pollution problem. However, airborne measurements indicate that the sulfur concentration decays (probably due to scavenging) as the plume is carried by the wind from the volcano, which limits the area of immediate danger to the public. Here we present size distribution for particulate matter collected during flights, near and far from the crater at various times. The particle data is then compared with simultaneously collected sulfur dioxide data and the rate of decay of is estimated. Sulfur and particle concentration variations with height in the far plume are presented. Some airborne measurements for H2S, NO, NO2 and CO2 will also be presented. This includes correlation matrices for simultaneous measurements of these gases and comparison to National Air Quality Standards and background values.

  6. Evaluation of Thermal Comfort and Contamination Control for a Cleanroom

    NASA Astrophysics Data System (ADS)

    Wang, Fu-Jen; Zheng, Yin-Rui; Lai, Chi-Ming; Chiang, Che-Ming

    There has been a substantial increase in the working environment of cleanroom. Special garments are therefore dressed in all cleanrooms to control particles and microbiological contamination dispersed from personnel in cleanrooms. However, more tightly-woven fabrics of cleanroom garments will result in thermal comfort dissatisfaction. In this study, field tests of a cleanroom have been carried out in our newly constructed MEMS laboratory. The ASHRAE thermal comfort code was conducted to investigate thermal comfort of personnel based on field-testing data consequently. Furthermore, the effects of clothing on thermal comfort and contamination control have been assessed comprehensively. The results from computer simulation and field tests indicated that there existed optimum compromise between the predicted mean vote and airborne particle counts under different cleanroom garments. The contamination control could be achieved by proper types of garments with satisfied thermal comfort of predict mean vote between 0.5-1.0.

  7. Monitoring marine pollution by airborne remote sensing techniques

    SciTech Connect

    Yuanfu, S.; Quanan, Z.

    1982-06-01

    In order to monitor marine pollution by airborne remote sensing techniques, some comprehensive test of airborne remote sensing, involving monitoring marine oil pollution, were performed at several bay areas of China. This paper presents some typical results of monitoring marine oil pollution. The features associated with the EM spectrum (visible, thermal infrared, and microwave) response of marine oil spills is briefly analyzed. It has been verified that the airborne oil surveillance systems manifested their advantages for monitoring the oil pollution of bay environments.

  8. Range Corrections for Airborne Radar - A Joint STARS Study

    DTIC Science & Technology

    1984-05-01

    ESD-TR-84-169 MTR-9055 RANGE CORRECTIONS FOR AIRBORNE RADAR - A JOINT STARS STUDY By • _,.G. A. ROBERTSHAW MAY 1984 - Prepared for DEPUTY COMMANDER...NO NO Hanscom AFB, MA 01731 6460 11. TITLE •Include securi,•,cleaficatton) Range Corrections Tor Airborne Radar - A Joint STARS Study 12. PERSONAL...SUPPLEMENTARY NOTATION 17 COSATI CODES 18. SUBJECT TERMS (Continue on reuera if necemary and identify by block number) FIELD GROUP SUB GR. Airborne Radar

  9. Radiative heating rates during AAOE and AASE. [Airborne Antarctic Ozone Experiment and Airborne Arctic Stratospheric Experiment

    NASA Technical Reports Server (NTRS)

    Rosenfield, Joan E.

    1990-01-01

    Radiative transit computations of heating rates utilizing data from the 1987 Airborne Antarctic Ozone Experiment (AAOE) (Tuck et al., 1989) and the 1989 Airborne Arctic Stratospheric Experiment (AASE) (Turco et al., 1990) are described. Observed temperature and ozone profiles and a radiative transfer model are used to compute the heating rates for the Southern Hemisphere during AAOE and the Northern Hemisphere during AASE. The AASE average cooling rates computed inside the vortex are in good agreement with the diabatic cooling rates estimated from the ER-2 profile data for N2O for the AASE period (Schoeberl et al., 1989).

  10. Airborne lidar experiments at the Savannah River Plant

    NASA Technical Reports Server (NTRS)

    Krabill, William B.; Swift, Robert N.

    1985-01-01

    The results of remote sensing experiments at the Department of Energy (DOE) Savannah River Nuclear Facility utilizing the NASA Airborne Oceanographic Lidar (AOL) are presented. The flights were conducted in support of the numerous environmental monitoring requirements associated with the operation of the facility and for the purpose of furthering research and development of airborne lidar technology. Areas of application include airborne laser topographic mapping, hydrologic studies using fluorescent tracer dye, timber volume estimation, baseline characterization of wetlands, and aquatic chlorophyll and photopigment measurements. Conclusions relative to the usability of airborne lidar technology for the DOE for each of these remote sensing applications are discussed.

  11. Raytheon low temperature RSP2 cryocooler airborne testing

    NASA Astrophysics Data System (ADS)

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T. J.

    2014-01-01

    The Raytheon Cryocooler Product Line tested the Low Temperature Stirling / Pulse Tube Hybrid 2-Stage (LTRSP2) cryocooler for an airborne application during 2012. Several tests were carried out to verify the ability of the machine to operate in an airborne environment. The vacuum level and heat rejection surface temperatures were varied to determine the performance over the excursions. Vibration testing was performed to prove that the LT-RSP2 cryocooler can operate on an airborne platform. This paper will present the results of the airborne characterization testing.

  12. Raytheon low temperature RSP2 cryocooler airborne testing

    NASA Astrophysics Data System (ADS)

    Schaefer, B. R.; Bellis, L.; Ellis, M. J.; Conrad, T. J.

    2013-09-01

    The Raytheon Cryocooler Product Line tested the Low Temperature Stirling / Pulse Tube Hybrid 2-Stage (LTRSP2) cryocooler for an airborne application during 2012. Several tests were carried out to verify the ability of the machine to operate in an airborne environment. The vacuum level and heat rejection surface temperatures were varied to determine the performance over the excursions. Vibration testing was performed to prove that the LT-RSP2 cryocooler can operate on an airborne platform. This paper will present the results of the airborne characterization testing.

  13. Absorption-Desorption Compressor for Spaceborne/Airborne Cryogenic Refrigerators.

    DTIC Science & Technology

    Refrigerant compressors, *Refrigeration systems), Spaceborne, Airborne, Cryogenics, Gases, Absorption, Desorption, Hydrogen, Hydrides, Lanthanum compounds, Nickel alloys, Joule Thomson effect , Heat transfer

  14. Toolsets for Airborne Data - URS and New Documentation

    Atmospheric Science Data Center

    2015-03-23

    ... missions, documentation, and EOSDIS User Registration System (URS) authentication. This web application features an intuitive user interface for variable selection across different airborne field studies and ...

  15. Surface contamination on LDEF exposed materials

    NASA Technical Reports Server (NTRS)

    Hemminger, Carol S.

    1992-01-01

    X-ray photoelectron spectroscopy (XPS) has been used to study the surface composition and chemistry of Long Duration Exposure Facility (LDEF) exposed materials including silvered Teflon (Ag/FEP), Kapton, S13GLO paint, quartz crystal monitors (QCM's), carbon fiber/organic matrix composites, and carbon fiber/Al Alloy composites. In each set of samples, silicones were the major contributors to the molecular film accumulated on the LDEF exposed surfaces. All surfaces analyzed have been contaminated with Si, O, and C; most have low levels (less than 1 atom percent) of N, S, and F. Occasionally observed contaminants included Cl, Na, K, P, and various metals. Orange/brown discoloration observed near vent slots in some Ag/FEP blankets were higher in carbon, sulfur, and nitrogen relative to other contamination types. The source of contamination has not been identified, but amine/amide functionalities were detected. It is probable that this same source of contamination account for the low levels of sulfur and nitrogen observed on most LDEF exposed surfaces. XPS, which probes 50 to 100 A in depth, detected the major sample components underneath the contaminant film in every analysis. This probably indicates that the contaminant overlayer is patchy, with significant areas covered by less that 100 A of molecular film. Energy dispersive x-ray spectroscopy (EDS) of LDEF exposed surfaces during secondary electron microscopy (SEM) of the samples confirmed contamination of the surfaces with Si and O. In general, particulates were not observed to develop from the contaminant overlayer on the exposed LDEF material surfaces. However, many SiO2 submicron particles were seen on a masked edge of an Ag/FEP blanket. In some cases such as the carbon fiber/organic matrix composites, interpretation of the contamination data was hindered by the lack of good laboratory controls. Examination of laboratory controls for the carbon fiber/Al alloy composites showed that preflight contamination was

  16. Effects of airborne black carbon pollution on maize

    NASA Astrophysics Data System (ADS)

    Illes, Bernadett; Anda, Angela; Soos, Gabor

    2013-04-01

    The black carbon (BC) changes the radiation balance of the Earth and contributes to global warming. The airborne BC deposited on the surface of plant, changing the radiation balance, water balance and the total dry matter (TDM) content of plant. The objective of our study was to investigate the impact of soot originated from motor vehicle exhaust on maize. The field experiment was carried out in Keszthely Agrometeorological Research Station (Hungary) in three consecutive years (2010, 2011, 2012) of growing season. The test plant was the maize hybrid Sperlona (FAO 340) with short growing season. The BC was chemically "pure", which means that it is free any contaminants (e.g. heavy metals). The BC was coming from the Hankook Tyre Company (Dunaújváros, Hungary), where used that for improve the wear resistance of tires. We used a motorised sprayer of SP 415 type to spray the BC onto the leaf surface. The leaf area index (LAI) was measured each week on the same 12 sample maize in each treatment using an LI 3000A automatic planimeter (LI-COR, Lincoln, NE). Albedo was measured by pyranometers of the CMA-11 type (Kipp & Zonen, Vaisala), what we placed the middle of the plot of 0.3 ha. The effects of BC were studied under two different water supplies: evapotranspirometers of Thornthwaite type were used for "ad libitum" treatment and rainfed treatment in field plots. In 2010 and 2012, a big difference was not observed in the case of LAI in the effects of BC. However, in 2011 there was a significant difference. The LAI of the BC polluted maize was higher (10-15%, P<0.05), than the LAI of the control maize in the rainfed plot and in the ET chambers, respectively. The albedo of the BC contaminated maize decreased (15-30%, P<0.05) in all three years. We also detected that the green plant surface of maize increased on BC contaminated treatment. These results may suggest that the plant is able to absorb the additional carbon source through the leaves. The albedo decreased

  17. Experiences with groundwater contamination

    SciTech Connect

    Not Available

    1984-01-01

    This book discusses developments in combating groundwater contamination. The papers include: Regulation of Groundwater; Utility Experiences Related to Existing and Proposed Drinking Water Regulations; Point-of-Use Treatment Technology to Control Organic and Inorganic Contamination; Hazardous Waste Disposal Practices and Groundwater Contamination; Reverse Osmosis Treatment to Control Inorganic and Volatile Organic Contamination; The Dilemma of New Wells Versus Treatment; Characteristics and Handling of Wastes From Groundwater Treatment Systems; and Removing Solvents to Restore Drinking Water at Darien, Connecticut.

  18. External induced contamination environment assessment for Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Leger, Lubert; Ehlers, Horst; Hakes, Charles; Theall, Jeff; Soares, Carlos

    1993-01-01

    An assessment of the Space Station Freedom performance as affected by the external induced contamination environment is in progress. The assessment procedure involves comparing the Space Station Freedom external contamination requirements, SSP 30426, Revision B (1991), with calculated molecular deposition, molecular column density, and other effects from potential sources of contamination. The current assessment comprises discussions of Space Shuttle proximity operations, Space Shuttle waste-water dumps (while docked to the Space Station), Space Station fluid and waste-gas venting, system gas leakage, external material outgassing, and a combined contamination assessment. This performance assessment indicates that Space Station Freedom contamination requirements are realistic and can be satisfied when all contamination sources are included.

  19. Post-Accident Sporadic Releases of Airborne Radionuclides from the Fukushima Daiichi Nuclear Power Plant Site.

    PubMed

    Steinhauser, Georg; Niisoe, Tamon; Harada, Kouji H; Shozugawa, Katsumi; Schneider, Stephanie; Synal, Hans-Arno; Walther, Clemens; Christl, Marcus; Nanba, Kenji; Ishikawa, Hirohiko; Koizumi, Akio

    2015-12-15

    The Fukushima nuclear accident (March 11, 2011) caused the widespread contamination of Japan by direct deposition of airborne radionuclides. Analysis of weekly air filters has revealed sporadic releases of radionuclides long after the Fukushima Daiichi reactors were stabilized. One major discharge was observed in August 2013 in monitoring stations north of the Fukushima Daiichi nuclear power plant (FDNPP). During this event, an air monitoring station in this previously scarcely contaminated area suddenly reported (137)Cs activity levels that were 30-fold above the background. Together with atmospheric dispersion and deposition simulation, radionuclide analysis in soil indicated that debris removal operations conducted on the FDNPP site on August 19, 2013 are likely to be responsible for this late release of radionuclides. One soil sample in the center of the simulated plume exhibited a high (90)Sr contamination (78 ± 8 Bq kg(-1)) as well as a high (90)Sr/(137)Cs ratio (0.04); both phenomena have usually been observed only in very close vicinity around the FDNPP. We estimate that through the resuspension of highly contaminated particles in the course of these earthmoving operations, gross (137)Cs activity of ca. 2.8 × 10(11) Bq has been released.

  20. Tonopah Test Range Air Monitoring: CY2015 Meteorological, Radiological, and Airborne Particulate Observations

    SciTech Connect

    Nikolich, George; Shadel, Craig; Chapman, Jenny; McCurdy, Greg; Etyemezian, Vicken; Miller, Julianne J.; Mizell, Steve

    2016-09-01

    In 1963, the U.S. Department of Energy (DOE) (formerly the Atomic Energy Commission [AEC]), implemented Operation Roller Coaster on the Tonopah Test Range (TTR) and an adjacent area of the Nevada Test and Training Range (NTTR) (formerly the Nellis Air Force Range). The operation resulted in radionuclide-contaminated soils at the Clean Slate I, II, and III sites. This report documents observations made during ongoing monitoring of radiological, meteorological, and dust conditions at stations installed adjacent to Clean Slate I and Clean Slate III, and at the TTR Sandia National Laboratories (SNL) Range Operations Control (ROC) center. The primary objective of the monitoring effort is to determine if winds blowing across the Clean Slate sites are transporting particles of radionuclide-contaminated soil beyond the physical and administrative boundaries of the sites. Radionuclide assessment of airborne particulates in 2015 found the gross alpha and gross beta values of dust collected from the filters at the monitoring stations are consistent with background conditions. The meteorological and particle monitoring indicate that conditions for wind-borne contaminant movement exist at the Clean Slate sites and that, although the transport of radionuclide-contaminated soil by suspension has not been detected, movement by saltation is occurring.

  1. 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

  2. The use of an experimental room for monitoring of airborne concentrations of microorganisms, glass fibers, and total particles

    SciTech Connect

    Buttner, M.P.; Stetzenbach, L.D.

    1996-12-31

    An experimental room was used as a microcosm for studies of airborne particles and microorganisms in indoor environments. The interior of the room measures 4 by 4 by 2.2 m high and has a hardwood floor and the walls and ceiling are sheetrocked and coated with interior latex paint. Exterior walls are 11.4-cm thick plywood panels consisting of two outer sections of plywood insulated with fiber glass batts. The ceiling is of similar construction with 17.1-cm thick panels. Attached to the room entrance is an anteroom equipped with a HEPA-filtered air shower to reduce mixing of air resulting from entering and exiting during experiments. The room is equipped with a computer-controlled heating, ventilation, and cooling system. Temperature, relative humidity, air flow, and room pressure can be continuously monitored by probes located in the room and air handling system components. Several research projects have been conducted using this room including monitoring the potential for airborne glass fibers released from rigid fibrous ductboard, comparisons of commercially available samplers for monitoring of airborne fungal spores, and a study on the efficacy of vacuum bags to minimize dispersal of particles, including fungal spores from fungal-contaminated carpet. During studies designed to monitor airborne fiberglass, air samples were taken in the room serviced by new rigid fibrous glass ductwork, and the results were compared to those obtained in the room with bare metal ductwork installed. Monitoring of airborne fungal spores using the Andersen six-stage sampler, the high flow Spiral Biotech sampler, the Biotest RCS Plus sampler, and the Burkard spore trap sampler was performed following the release of Penicillium spores into the room through the supply register. Dispersal of carpet-associated particles and fungal spores was measured after vacuuming using conventional cellulose vacuum bags in comparison to recently developed bags.

  3. Airborne Astronomy Symposium. A symposium commemorating the tenth anniversary of operations of the Kuiper Airborne Observatory

    NASA Technical Reports Server (NTRS)

    Thronson, H. A., Jr. (Editor); Erickson, E. F. (Editor)

    1984-01-01

    Airborne infrared astronomy is discussed with respect to observations of the solar system, stars, star formation, and the interstellar medium. Far infrared characteristics of the Milky Way, its center, and other galaxies are considered. The instrumentation associated with IR astronomy is addressed.

  4. Contamination transport modeling with CTSP (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Brieda, Lubos

    2016-09-01

    CTSP (Contamination Transport Simulation Program) is a simulation program for performing detailed molecular and particulate contaminant transport analyses using complex, CAD-generated geometries. CTSP concurrently traces many simulation macroparticles, allowing it to compute contaminant partial pressures. The code uses a detailed surface model that supports multiple trapped gases and a multi-component surface layer. The molecular residence time is computed by considering surface temperature and activation energies. This paper describes the implemented algorithms and demonstrates the code with several test cases. These include outgassing in a vacuum chamber, spacecraft venting, particulate transport in an air flow, and redistribution of paint flakes on an orbiting satellite. The paper is concluded by summarizing the on-going effort to parallelize the code and utilize GPUs, and to add support for electrostatic return modeling by computing space potential using Green's functions.

  5. NEON Airborne Remote Sensing of Terrestrial Ecosystems

    NASA Astrophysics Data System (ADS)

    Kampe, T. U.; Leisso, N.; Krause, K.; Karpowicz, B. M.

    2012-12-01

    The National Ecological Observatory Network (NEON) is the continental-scale research platform that will collect information on ecosystems across the United States to advance our understanding and ability to forecast environmental change at the continental scale. One of NEON's observing systems, the Airborne Observation Platform (AOP), will fly an instrument suite consisting of a high-fidelity visible-to-shortwave infrared imaging spectrometer, a full waveform small footprint LiDAR, and a high-resolution digital camera on a low-altitude aircraft platform. NEON AOP is focused on acquiring data on several terrestrial Essential Climate Variables including bioclimate, biodiversity, biogeochemistry, and land use products. These variables are collected throughout a network of 60 sites across the Continental United States, Alaska, Hawaii and Puerto Rico via ground-based and airborne measurements. Airborne remote sensing plays a critical role by providing measurements at the scale of individual shrubs and larger plants over hundreds of square kilometers. The NEON AOP plays the role of bridging the spatial scales from that of individual organisms and stands to the scale of satellite-based remote sensing. NEON is building 3 airborne systems to facilitate the routine coverage of NEON sites and provide the capacity to respond to investigator requests for specific projects. The first NEON imaging spectrometer, a next-generation VSWIR instrument, was recently delivered to NEON by JPL. This instrument has been integrated with a small-footprint waveform LiDAR on the first NEON airborne platform (AOP-1). A series of AOP-1 test flights were conducted during the first year of NEON's construction phase. The goal of these flights was to test out instrument functionality and performance, exercise remote sensing collection protocols, and provide provisional data for algorithm and data product validation. These test flights focused the following questions: What is the optimal remote

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

    SciTech Connect

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

    2001-01-01

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

  7. Even Shallower Exploration with Airborne Electromagnetics

    NASA Astrophysics Data System (ADS)

    Auken, E.; Christiansen, A. V.; Kirkegaard, C.; Nyboe, N. S.; Sørensen, K.

    2015-12-01

    Airborne electromagnetics (EM) is in many ways undergoing the same type rapid technological development as seen in the telecommunication industry. These developments are driven by a steadily increasing demand for exploration of minerals, groundwater and geotechnical targets. The latter two areas demand shallow and accurate resolution of the near surface geology in terms of both resistivity and spatial delineation of the sedimentary layers. Airborne EM systems measure the grounds electromagnetic response when subject to either a continuous discrete sinusoidal transmitter signal (frequency domain) or by measuring the decay of currents induced in the ground by rapid transmission of transient pulses (time domain). In the last decade almost all new developments of both instrument hardware and data processing techniques has focused around time domain systems. Here we present a concept for measuring the time domain response even before the transient transmitter current has been turned off. Our approach relies on a combination of new instrument hardware and novel modeling algorithms. The newly developed hardware allows for measuring the instruments complete transfer function which is convolved with the synthetic earth response in the inversion algorithm. The effect is that earth response data measured while the transmitter current is turned off can be included in the inversion, significantly increasing the amount of available information. We demonstrate the technique using both synthetic and field data. The synthetic examples provide insight on the physics during the turn off process and the field examples document the robustness of the method. Geological near surface structures can now be resolved to a degree that is unprecedented to the best of our knowledge, making airborne EM even more attractive and cost-effective for exploration of water and minerals that are crucial for the function of our societies.

  8. Airborne seeker evaluation and test system

    NASA Astrophysics Data System (ADS)

    Jollie, William B.

    1991-08-01

    The Airborne Seeker Evaluation Test System (ASETS) is an airborne platform for development, test, and evaluation of air-to-ground seekers and sensors. ASETS consists of approximately 10,000 pounds of equipment, including sixteen racks of control, display, and recording electronics, and a very large stabilized airborne turret, all carried by a modified C- 130A aircraft. The turret measures 50 in. in diameter and extends over 50 in. below the aircraft. Because of the low ground clearance of the C-130, a unique retractor mechanism was designed to raise the turret inside the aircraft for take-offs and landings, and deploy the turret outside the aircraft for testing. The turret has over 7 cubic feet of payload space and can accommodate up to 300 pounds of instrumentation, including missile seekers, thermal imagers, infrared mapping systems, laser systems, millimeter wave radar units, television cameras, and laser rangers. It contains a 5-axis gyro-stabilized gimbal system that will maintain a line of sight in the pitch, roll, and yaw axes to an accuracy better than +/- 125 (mu) rad. The rack-mounted electronics in the aircraft cargo bay can be interchanged to operate any type of sensor and record the data. Six microcomputer subsystems operate and maintain all of the system components during a test mission. ASETS is capable of flying at altitudes between 200 and 20,000 feet, and at airspeeds ranging from 100 to 250 knots. Mission scenarios can include air-to-surface seeker testing, terrain mapping, surface target measurement, air-to-air testing, atmospheric transmission studies, weather data collection, aircraft or missile tracking, background signature measurements, and surveillance. ASETS is fully developed and available to support test programs.

  9. Exposure to airborne microorganisms in furniture factories.

    PubMed

    Krysińska-Traczyk, Ewa; Skórska, Czesława; Cholewa, Grazyna; Sitkowska, Jolanta; Milanowski, Janusz; Dutkiewicz, Jacek

    2002-01-01

    Microbiological air sampling was performed in 2 furniture factories located in eastern Poland. In one factory furniture were made from fibreboards and chipboards while in the other from beech wood. It was found that the concentration of total microorganisms (bacteria + fungi) in the air of the facility using beech wood for furniture production (mean 10.7 x (3) cfu/m(3), range 3.3 27.5 x (3) cfu/m(3)) was significantly higher (p < 0.01) compared to microbial concentration in the facility using fibre- and chipboards (mean 3.6 x (3) cfu/m(3), range 1.9-6.2 x (3) cfu/m(3)). On average, the commonest microorganisms in the air of the furniture factories were corynebacteria (Corynebacterium spp., Arthrobacter spp., Brevibacterium spp.) which formed 18.1-50.0% of the total airborne microflora, and fungi (mostly Aspergillus spp., Penicillium spp., Absidia spp. and yeasts) which formed 6.2-54.4% of the total count. The values of the respirable fraction of airborne microflora in the furniture factories varied within fairly wide limits and were between 15.0-62.4%. Altogether, 28 species or genera of bacteria and 12 species or genera of fungi were identified in the air of examined factories, of which respectively 8 and 7 species or genera were reported as having allergenic and/or immunotoxic properties. In conclusion, the workers of furniture factories are exposed to relatively low concentrations of airborne microorganisms which do not exceed the suggested occupational exposure limits. Nevertheless, the presence of allergenic and/or immunotoxic microbial species in the air of factories poses a potential risk of respiratory disease, in particular in sensitive workers.

  10. Simultaneous determination of aliphatic and aromatic amines in ambient air and airborne particulate matters by gas chromatography-mass spectrometry

    NASA Astrophysics Data System (ADS)

    Akyüz, Mehmet

    2008-05-01

    A gas chromatography-mass spectrometry (GC-MS) method has been proposed for the simultaneous determination of aliphatic and aromatic amines in ambient air and airborne particulate matters (PMs). The method includes collection of the particulate matters (PM2.5 and PM10) using dichotomous Partisol 2025 sampler followed by extraction of the compounds into acidic solution, and pre-concentration of the compounds by percolating the air samples through the acidic solution, then ion-pair extraction of amines with bis-2-ethylhexylphosphate and derivatisation with isobutyl chloroformate prior to their GC-MS analysis in both electron impact and positive and negative ion chemical ionisation mode as their isobutyloxycarbonyl (isoBOC) derivatives. In the present study, ambient air and airborne particulate samples collected in Zonguldak province during summer and winter times of 2006-2007 were analysed for aliphatic and aromatic amines by the proposed method and the method was shown to be suitable for the simultaneous determination of these compounds at the levels of pg m-3 in air and airborne particulate samples. The seasonal distributions of bioactive amines in concentrations in ambient air and airborne PMs were evaluated as they are significant for the estimation of their effects on the environment and human health. The concentration levels of water soluble amines fluctuate significantly within a year with higher means and peak concentrations, probably due to the increased emissions from coal-fired domestic and central heating, in the winter times compared to the summer times. The results indicated that the relative amine content in particulates modulates with molecular mass and time of the year and the relative amine content especially in fine fractions of inhalable airborne particulates increases with the molecular mass of species but decreases with temperature.

  11. Airborne optical detection of oil on water.

    NASA Technical Reports Server (NTRS)

    Millard, J. P.; Arvesen, J. C.

    1972-01-01

    Airborne measurements were made over controlled oil-spill test sites to evaluate various techniques, utilizing reflected sunlight, for detecting oil on water. The results of these measurements show that (1) maximum contrast between oil and water is in the UV and red portions of the spectrum; (2) minimum contrast is in the blue-green; (3) differential polarization appears to be a very promising technique; (4) no characteristic absorption bands, which would permit one oil to be distinguished from another, were discovered in the spectral regions measured; (5) sky conditions greatly influence the contrast between oil and water; and (6) highest contrast was achieved under overcast sky conditions.

  12. A prospectus on airborne laser mapping systems

    NASA Technical Reports Server (NTRS)

    Link, L. E.; Krabill, W. B.; Swift, R. N.

    1983-01-01

    Airborne laser systems have demonstrated enormous potential for topographic and bathymetric mapping. Both profiling and scanning systems have been evaluated for terrain elevation mapping, stream valley cross-section determination, and nearshore bottom profiling. Performance of the laser systems has been impressive and for some applications matches current operational accuracy requirements. Determining the position of individual laser measurements remains a constraint for most applications. Laser technology constrains some terrain and bathymetric applications, particularly for water penetration and frequency of measurements for high-spatial resolution over large areas.

  13. Aircraft deployment, and airborne arctic stratospheric expedition

    NASA Technical Reports Server (NTRS)

    Condon, Estelle; Tuck, Adrian; Hipskind, Steve; Toon, Brian; Wegener, Steve

    1990-01-01

    The Airborne Arctic Stratospheric Expedition had two primary objectives: to study the production and loss mechanisms of ozone in the north polar stratosphere and to study the effect on ozone distribution of the Arctic Polar Vortex and of the cold temperatures associated with the formation of Polar Stratospheric Clouds. Two specially instrumented NASA aircraft were flown over the Arctic region. Each aircraft flew to acquire data on the meteorological, chemical and cloud physical phenomena that occur in the polar stratosphere during winter. The chemical processes which occur in the polar stratosphere during winter were also observed and studied. The data acquired are being analyzed.

  14. Highly Protable Airborne Multispectral Imaging System

    NASA Technical Reports Server (NTRS)

    Lehnemann, Robert; Mcnamee, Todd

    2001-01-01

    A portable instrumentation system is described that includes and airborne and a ground-based subsytem. It can acquire multispectral image data over swaths of terrain ranging in width from about 1.5 to 1 km. The system was developed especially for use in coastal environments and is well suited for performing remote sensing and general environmental monitoring. It includes a small,munpilotaed, remotely controlled airplance that carries a forward-looking camera for navigation, three downward-looking monochrome video cameras for imaging terrain in three spectral bands, a video transmitter, and a Global Positioning System (GPS) reciever.

  15. The fate of airborne polycyclic organic matter.

    PubMed Central

    Nielsen, T; Ramdahl, T; Bjørseth, A

    1983-01-01

    Biological tests have shown that a significant part of the mutagenicity of organic extracts of collected airborne particulate matter is not due to polycyclic aromatic hydrocarbons (PAH). It is possible that part of these unknown compounds are transformation products of PAH. This survey focuses on the reaction of PAH in the atmosphere with other copollutants, such as nitrogen oxides, sulfur oxides, ozone and free radicals and their reaction products. Photochemically induced reactions of PAH are also included. The reactivity of particle-associated PAH is discussed in relation to the chemical composition and the physical properties of the carrier. Recommendations for future work are given. PMID:6825615

  16. Refractive acoustic devices for airborne sound.

    PubMed

    Cervera, F; Sanchis, L; Sánchez-Pérez, J V; Martínez-Sala, R; Rubio, C; Meseguer, F; López, C; Caballero, D; Sánchez-Dehesa, J

    2002-01-14

    We show that a sonic crystal made of periodic distributions of rigid cylinders in air acts as a new material which allows the construction of refractive acoustic devices for airborne sound. It is demonstrated that, in the long-wave regime, the crystal has low impedance and the sound is transmitted at subsonic velocities. Here, the fabrication and characterization of a convergent lens are presented. Also, an example of a Fabry-Perot interferometer based on this crystal is analyzed. It is concluded that refractive devices based on sonic crystals behave in a manner similar to that of optical systems.

  17. A spherical gas bearing for airborne application

    NASA Technical Reports Server (NTRS)

    Bouvier, A.; Schmertz, J. C.

    1974-01-01

    A spherical gas bearing is analyzed and tested for an airborne application. The externally pressurized bearing supports an inertially stabilized 36-in aperture, infrared telescope. The bearing provides the isolation of rotary motion from the aircraft and also serves as a seal between the aircraft cabin and cavity condition at 50,000 ft altitude. The accompanying temperature gradient of 135 F across the 16-in.-diam bearing created special design and manufacturing considerations. Test data on the static load under temperature and vacuum environment are presented in support of the analysis.

  18. Airborne Data Link Operational Evaluation Test Plan

    DTIC Science & Technology

    1993-08-01

    Peg* 1. Rep meft .2. Gowe,; , Accessio, No. 3. Recspsent’s Catel " No. DOT/FAA/CT-TN93/30 I 4. Title and Subtite 5. Roep,, .t. AIRBORNE DATA LINK...320 15. Supplementary Notes 16 . Abstract This plan desci. s an end-to-end study of operational concepts and procedures associated with the introduction...4.4 Dependent Measures 9 4.5 ATC Messages 14 4.6 Flight Scenarios 14 4.7 Support Personnel 15 4.8 Data Reduction and Analysis 16 5. SCHEDULE 16 5.1

  19. Stressed detector arrays for airborne astronomy

    NASA Technical Reports Server (NTRS)

    Stacey, G. J.; Beeman, J. W.; Haller, E. E.; Geis, N.; Poglitsch, A.; Rumitz, M.

    1989-01-01

    The development of stressed Ge:Ga detector arrays for far-infrared astronomy from the Kuiper Airborne Observatory (KAO) is discussed. Researchers successfully constructed and used a three channel detector array on five flights from the KAO, and have conducted laboratory tests of a two-dimensional, 25 elements (5x5) detector array. Each element of the three element array performs as well as the researchers' best single channel detector, as do the tested elements of the 25 channel system. Some of the exciting new science possible with far-infrared detector arrays is also discussed.

  20. Airborne Bistatic Radar Limitations and Sample Calculations

    DTIC Science & Technology

    1985-12-01

    Any parameter which maximizes the viewing area of the receiver platform is a prime candidate for change if the transmitter wishes to deny or decrease...AES-19, NO. 4, 513-520 (July 1983) 4. Lorti , D. "Airborne Bistatic RadaL Operation With Non-Cooperative Transmitters," Aeronautical Systems Divi- ’V...nology Center. Contract DASG60-82-C-0014 with McDonnell Douglas Research Labs. Huntsville AL. July 1982. 7. Moreno, C, and D. Lorti . "Tactical