Science.gov

Sample records for air sample filters

  1. Air Sampling Filter

    NASA Technical Reports Server (NTRS)

    1980-01-01

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

  2. Optimization of the development process for air sampling filter standards

    NASA Astrophysics Data System (ADS)

    Mena, RaJah Marie

    Air monitoring is an important analysis technique in health physics. However, creating standards which can be used to calibrate detectors used in the analysis of the filters deployed for air monitoring can be challenging. The activity of a standard should be well understood, this includes understanding how the location within the filter affects the final surface emission rate. The purpose of this research is to determine the parameters which most affect uncertainty in an air filter standard and optimize these parameters such that calibrations made with them most accurately reflect the true activity contained inside. A deposition pattern was chosen from literature to provide the best approximation of uniform deposition of material across the filter. Samples sets were created varying the type of radionuclide, amount of activity (high activity at 6.4 -- 306 Bq/filter and one low activity 0.05 -- 6.2 Bq/filter, and filter type. For samples analyzed for gamma or beta contaminants, the standards created with this procedure were deemed sufficient. Additional work is needed to reduce errors to ensure this is a viable procedure especially for alpha contaminants.

  3. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY AIR FILTER SAMPLES

    SciTech Connect

    Maxwell, S.; Noyes, G.; Culligan, B.

    2010-02-03

    A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and {sup 90}Sr in air filter results were reported in {approx}4 hours with excellent quality.

  4. Evaluation of membrane filter field monitors for microbiological air sampling

    NASA Technical Reports Server (NTRS)

    Fields, N. D.; Oxborrow, G. S.; Puleo, J. R.; Herring, C. M.

    1974-01-01

    Due to area constraints encountered in assembly and testing areas of spacecraft, the membrane filter field monitor (MF) and the National Aeronautics and Space Administration-accepted Reyniers slit air sampler were compared for recovery of airborne microbial contamination. The intramural air in a microbiological laboratory area and a clean room environment used for the assembly and testing of the Apollo spacecraft was studied. A significantly higher number of microorganisms was recovered by the Reyniers sampler. A high degree of consistency between the two sampling methods was shown by a regression analysis, with a correlation coefficient of 0.93. The MF samplers detected 79% of the concentration measured by the Reyniers slit samplers. The types of microorganisms identified from both sampling methods were similar.

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

    NASA Technical Reports Server (NTRS)

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

    1974-01-01

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

  6. The use of Whatman-41 filters for high volume air sampling

    NASA Technical Reports Server (NTRS)

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

    1975-01-01

    The feasibility of using W41 filter media on a routine TSP high-volume monitoring network was determined by comparison with glass fiber (GF) filtering. Results indicate that suspended particulate samples from GF filters averaged slightly, but not significantly, higher than those from Whatman-41 filters. Some extra handling procedures were required to avoid errors due to the hygroscopic nature of W41 filters; these added procedures are not overly burdensome, however, and they allow the performance of analytical work, thus extending the capabilities of high-volume sampling. It was demonstrated that W41 filters are practical for air quality monitoring and elemental analysis in environments similar to Cleveland's.

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

    PubMed

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

    2012-11-01

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

  8. EVALUATION OF THE FILTER PACK FOR LONG-DURATION SAMPLING OF AMBIENT AIR

    EPA Science Inventory

    A 14-week filter pack (FP) sampler evaluation field study was conducted at a site near Bondville, IL to investigate the impact of weekly sampling duration. Simultaneous samples were collected using collocated filter packs (FP) from two independent air quality monitoring networks...

  9. Problems Found Using a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    SciTech Connect

    Robert Hayes

    2008-04-01

    An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion of anthropogenic activity estimates with the relative bias being small compared to the dispersion, indicating that the system would not give false positive indications for an appropriately set decision level. By also measuring environmental air sample filters simultaneously with electroplated alpha filters, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations from calibrated values indicating that the system would give false negative indications. Use of the current algorithm is, therefore, not recommended for general assay applications. Use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve-fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha activities on air sample filters (not due to radon progeny) around the 200 disintegrations per minute level.

  10. Use of a Radon Stripping Algorithm for Retrospective Assessment of Air Filter Samples

    SciTech Connect

    Robert Hayes

    2009-01-23

    An evaluation of a large number of air sample filters was undertaken using a commercial alpha and beta spectroscopy system employing a passive implanted planar silicon (PIPS) detector. Samples were only measured after air flow through the filters had ceased. Use of a commercial radon stripping algorithm was implemented to discriminate anthropogenic alpha and beta activity on the filters from the radon progeny. When uncontaminated air filters were evaluated, the results showed that there was a time-dependent bias in both average estimates and measurement dispersion with the relative bias being small compared to the dispersion. By also measuring environmental air sample filters simultaneously with electroplated alpha and beta sources, use of the radon stripping algorithm demonstrated a number of substantial unexpected deviations. Use of the current algorithm is therefore not recommended for assay applications and so use of the PIPS detector should only be utilized for gross counting without appropriate modifications to the curve fitting algorithm. As a screening method, the radon stripping algorithm might be expected to see elevated alpha and beta activities on air sample filters (not due to radon progeny) around the 200 dpm level.

  11. Curve fitting air sample filter decay curves to estimate transuranic content.

    PubMed

    Hayes, Robert B; Chiou, Hung Cheng

    2004-01-01

    By testing industry standard techniques for radon progeny evaluation on air sample filters, a new technique is developed to evaluate transuranic activity on air filters by curve fitting the decay curves. The industry method modified here is simply the use of filter activity measurements at different times to estimate the air concentrations of radon progeny. The primary modification was to not look for specific radon progeny values but rather transuranic activity. By using a method that will provide reasonably conservative estimates of the transuranic activity present on a filter, some credit for the decay curve shape can then be taken. By carrying out rigorous statistical analysis of the curve fits to over 65 samples having no transuranic activity taken over a 10-mo period, an optimization of the fitting function and quality tests for this purpose was attained. PMID:14695010

  12. SO 2 sorption characteristics of air sampling filter media using a new laboratory test

    NASA Astrophysics Data System (ADS)

    Batterman, Stuart; Osak, Igor; Gelman, Charles

    A significant factor in the selection of filter media used for air sampling is the formation of artifacts due to the sorption of sulfur and nitrogen oxides on the filter. These artifacts can erroneously increase measured particulate concentrations. A technique is developed to measure the uptake of SO 2 and other gases and vapors on air sampling filter media. The static chamber technique features in-chamber measurements of SO 2 concentrations using FTIR spectrometry. The filter uptake, partition coefficient, and diffusion coefficient are estimated from the loss of gaseous SO 2 in the chamber. The technique provides rapid and precise results over a wide range of filter characteristics and avoids problems related to the extraction of target analytes from the filter. A total of 12 types of filters are evaluated, including glass fiber, Teflon-coated glass fiber, nylon, quartz fiber, Teflon, Supor, Nylasorb, and acrylic copolymer membranes. Results indicate that Teflon, quartz and acrylic copolymer filters have minimal sorption of SO 2 while quartz fiber, Supor and Nylasorb filters have high to moderate uptake of SO 2.

  13. Results of Self-Absorption Study on the Versapor 3000 Filters for Radioactive Particulate Air Sampling

    SciTech Connect

    Barnett, J. Matthew; Cullinan, Valerie I.; Barnett, Debra S.; Trang-Le, Truc LT; Bliss, Mary; Greenwood, Lawrence R.; Ballinger, Marcel Y.

    2009-02-17

    Since the mid-1980s, Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as the correction factor for self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. This value accounts for activity that cannot be detected by direct counting of alpha and beta particles. Emissions can be degraded or blocked by filter fibers for particles buried in the filter material or by inactive dust particles collected with the radioactive particles. These filters are used for monitoring air emissions from PNNL stacks for radioactive particles. This paper describes an effort to re-evaluate self-absorption effects in particulate radioactive air sample filters (Versapor® 3000, 47 mm diameter) used at PNNL. There were two methods used to characterize the samples. Sixty samples were selected from the archive for acid digestion to compare the radioactivity measured by direct gas-flow proportional counting of filters to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection. Thirty different sample filters were selected for visible light microscopy to evaluate filter loading and particulate characteristics. Mass-loading effects were also considered. Filter ratios were calculated by dividing the initial counts by the post-digestion counts with the expectation that post-digestion counts would be higher because digestion would expose radioactivity embedded in the filter in addition to that on top of the filter. Contrary to expectations, the post digestion readings were almost always lower than initial readings and averaged approximately half the initial readings for both alpha and beta activity. Before and after digestion readings appeared to be related to each other, but with a low coefficient of determination (R^2) value. The ratios had a wide range of values indicating that this method did not provide sufficient precision to quantify self

  14. The NYC native air sampling pilot project: using HVAC filter data for urban biological incident characterization.

    PubMed

    Ackelsberg, Joel; Leykam, Frederic M; Hazi, Yair; Madsen, Larry C; West, Todd H; Faltesek, Anthony; Henderson, Gavin D; Henderson, Christopher L; Leighton, Terrance

    2011-09-01

    Native air sampling (NAS) is distinguished from dedicated air sampling (DAS) devices (eg, BioWatch) that are deployed to detect aerosol disseminations of biological threat agents. NAS uses filter samples from heating, ventilation, and air conditioning (HVAC) systems in commercial properties for environmental sampling after DAS detection of biological threat agent incidents. It represents an untapped, scientifically sound, efficient, widely distributed, and comparably inexpensive resource for postevent environmental sampling. Calculations predict that postevent NAS would be more efficient than environmental surface sampling by orders of magnitude. HVAC filter samples could be collected from pre-identified surrounding NAS facilities to corroborate the DAS alarm and delineate the path taken by the bioaerosol plume. The New York City (NYC) Native Air Sampling Pilot Project explored whether native air sampling would be acceptable to private sector stakeholders and could be implemented successfully in NYC. Building trade associations facilitated outreach to and discussions with property owners and managers, who expedited contact with building managers of candidate NAS properties that they managed or owned. Nominal NAS building requirements were determined; procedures to identify and evaluate candidate NAS facilities were developed; data collection tools and other resources were designed and used to expedite candidate NAS building selection and evaluation in Manhattan; and exemplar environmental sampling playbooks for emergency responders were completed. In this sample, modern buildings with single or few corporate tenants were the best NAS candidate facilities. The Pilot Project successfully demonstrated that in one urban setting a native air sampling strategy could be implemented with effective public-private collaboration. PMID:21793731

  15. Nonuniform air flow in inlets: the effect on filter deposits in the fiber sampling cassette.

    PubMed

    Baron, P A; Chen, C C; Hemenway, D R; O'Shaughnessy, P

    1994-08-01

    Smoke stream studies were combined with a new technique for visualizing a filter deposit from samples used to monitor asbestos or other fibers. Results clearly show the effect of secondary flow vortices within the sampler under anisoaxial sampling conditions. The vortices observed at low wind velocities occur when the inlet axis is situated at angles between 45 degrees and 180 degrees to the motion of the surrounding air. It is demonstrated that the vortices can create a complex nonuniform pattern in the filter deposit, especially when combined with particle settling or electrostatic interactions between the particles and the sampler. Inertial effects also may play a role in the deposit nonuniformity, as well as causing deposition on the cowl surfaces. Changes in the sampler, such as its placement, may reduce these biases. The effects noted are not likely to occur in all sampling situations, but may explain some reports of high variability on asbestos fiber filter samples. The flow patterns observed in this study are applicable to straight, thin-walled inlets. Although only compact particles were used, the air flow patterns and forces involved will have similar effects on fibers of the same aerodynamic diameter. PMID:7942509

  16. Recirculating electric air filter

    DOEpatents

    Bergman, Werner

    1986-01-01

    An electric air filter cartridge has a cylindrical inner high voltage eleode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

  17. Recirculating electric air filter

    DOEpatents

    Bergman, W.

    1985-01-09

    An electric air filter cartridge has a cylindrical inner high voltage electrode, a layer of filter material, and an outer ground electrode formed of a plurality of segments moveably connected together. The outer electrode can be easily opened to remove or insert filter material. Air flows through the two electrodes and the filter material and is exhausted from the center of the inner electrode.

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - AIR PURATOR CORPORATION HUYGLAS 1405M FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  19. Results of a Self-Absorption Study on the Versapor 3000 47-mm Filters for Radioactive Particulate Air Stack Sampling

    SciTech Connect

    Barnett, J. Matthew; Cullinan, Valerie I.; Barnett, Debra S.; Trang-Le, Truc LT; Bliss, Mary; Greenwood, Lawrence R.; Ballinger, Marcel Y.

    2009-11-01

    Since the mid-1980s the Pacific Northwest National Laboratory (PNNL) has used a value of 0.85 as a correction factor for the self absorption of activity for particulate radioactive air samples collected from building exhaust for environmental monitoring. More recently, an effort was made to evaluate the current particulate radioactive air sample filters (Versapor® 3000, 47-mm diameter) used at PNNL for self absorption effects. There were two methods used to characterize the samples. Sixty samples were selected from the archive for acid digestion to compare the radioactivity measured by direct gas-flow proportional counting of filters to the results obtained after acid digestion of the filter and counting again by gas-flow proportional detection. Thirty different sample filters were selected for visible light microscopy to evaluate filter loading and particulate characteristics. Mass-loading effects were also considered. Large error is associated with the sample filter analysis comparison and subsequently with the estimation of the absorption factor resulting in an inadequate method to estimate losses from self-absorption in the sample filter. The mass loading on the sample filter as determined after digestion and drying was ~0.08 mg cm-2; however, this value may not represent the total filter mass loading given that there may be undetermined losses associated with the digestion process. While it is difficult to determine how much material is imbedded in the filter, observations from the microscopy analysis indicate that the vast majority of the particles remain on the top of the filter. In comparing the results obtained, the continued use of 0.85 as a conservative correction factor is recommended.

  20. HEPA air filter (image)

    MedlinePlus

    ... pet dander and other irritating allergens from the air. Along with other methods to reduce allergens, such ... controlling the amount of allergens circulating in the air. HEPA filters can be found in most air ...

  1. Testing Air-Filtering Systems

    PubMed Central

    Songer, Joseph R.; Sullivan, James F.; Hurd, James W.

    1963-01-01

    A procedure was developed for evaluating high-efficiency filters mounted in exhaust ducts at the National Animal Disease Laboratory. An aerosol of the test organism, Escherichia coli B T3 bacteriophage, was generated in a chamber attached to a ceiling exhaust register in concentrations of at least 1000 viable organisms per ft3 of air. Samples were collected from both the pre- and postfilter areas, and the number of organisms per ft3 of air was determined. The efficiency of the filter was calculated from these figures. A total of 269 high-efficiency filters were tested. Of these, 249 had efficiencies of 98% or greater. The remaining 20, with efficiencies of less than 98%, were repaired and retested. No filter was accepted with an efficiency of less than 98%. Images Fig. 2 PMID:14063779

  2. Disinfecting Filters For Recirculated Air

    NASA Technical Reports Server (NTRS)

    Pilichi, Carmine A.

    1992-01-01

    Simple treatment disinfects air filters by killing bacteria, algae, fungi, mycobacteria, viruses, spores, and any other micro-organisms filters might harbor. Concept applied to reusable stainless-steel wire mesh filters and disposable air filters. Treatment used on filters in air-circulation systems in spacecraft, airplanes, other vehicles, and buildings to help prevent spread of colds, sore throats, and more-serious illnesses.

  3. Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 2: Sampling capacity and breakthrough tests for sodium carbonate-impregnated filters.

    PubMed

    Demange, Martine; Oury, Véronique; Rousset, Davy

    2011-11-01

    In France, the MétroPol 009 method used to measure workplace exposure to inorganic acids, such as HF, HCl, and HNO3, consists of a closed-face cassette fitted with a prefilter to collect particles, and two sodium carbonate-impregnated filters to collect acid vapor. This method was compared with other European methods during the development of a three-part standard (ISO 21438) on the determination of inorganic acids in workplace air by ion chromatography. Results of this work, presented in a companion paper, led to a need to go deeper into the performance of the MétroPol 009 method regarding evaluation of the breakthrough of the acids, both alone and in mixtures, interference from particulate salts, the amount of sodium carbonate required to impregnate the sampling filter, the influence of sampler components, and so on. Results enabled improvements to be made to the sampling device with respect to the required amount of sodium carbonate to sample high HCl or HNO3 concentrations (500 μL of 5% Na2CO3 on each of two impregnated filters). In addition, a PVC-A filter used as a prefilter in a sampling device showed a propensity to retain HNO3 vapor so a PTFE filter was considered more suitable for use as a prefilter. Neither the material of the sampling cassette (polystyrene or polypropylene) nor the sampling flowrate (1 L/min or 2 L/min) influenced the performance of the sampling device, as a recovery of about 100% was achieved in all experiments for HNO3, HCl, and HF, as well as HNO3+HF and HNO3+HCl mixtures, over a wide range of concentrations. However, this work points to the possibility of interference between an acid and salts of other acids. For instance, interference can occur through interaction of HNO3 with chloride salts: the stronger the acid, the greater the interference. Methods based on impregnated filters are reliable for quantitative recovery of inorganic volatile acids in workplace atmosphere but are valuable only in the absence of interferents. PMID

  4. Air filtering device

    SciTech Connect

    Backus, A.L.

    1992-07-28

    This patent describes a room air cleaning device. It comprises: a box housing having an air inlet and an air outlet provided therein; a vertical baffle coupled to the box housing opposite the air outlet and spaced form the box housing such that an air egress outlet is formed between the vertical baffle and the box housing; air cleansing means substantially disposed within the box housing and cleansing air passing into the inlet and out of the air egress outlet; a fan disposed within the box housing, the fan providing air movement through the air inlet and the air egress outlet; wherein air exits the room air cleaning device through the air egress outlet as a vertical plane of moving air; and wherein formation of the vertical plane of moving air contributes to the formation of a low pressure area drawing impure air toward the air inlet.

  5. Early detection of foot-and-mouth disease virus from infected cattle using a dry filter air sampling system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foot-and-mouth disease (FMD) is a highly contagious livestock disease of high economic impact. Early detection of FMD virus (FMDV) is fundamental for rapid outbreak control. Air sampling collection has been demonstrated as a useful technique for detection of FMDV RNA in infected animals, related to ...

  6. Viability of bacteria in unused air filter media

    NASA Astrophysics Data System (ADS)

    Maus, R.; Goppelsröder, A.; Umhauer, H.

    Different experimental techniques were applied to determine the effects of different air filter media on the viability of bacteria. Rinse suspensions of unused filter media were employed in standard inhibition tests to determine the effects of filter ingredients on bacterial growth under ideal nutritional conditions. Furthermore, a new test procedure was proposed and validated to determine the survival of viable microorganisms in fibrous air filters as a function of different parameters. Samples of filter media were challenged with microbial aerosols in an experimental set-up designed for measuring the collection efficiencies of fibrous filters. The loaded filter samples were then challenged with clean air under controlled conditions for a definite time span and numbers of viable microorganisms in the filter media were determined as colony forming units. The filter samples were retrieved from unused filter media usually employed in common air conditioning and ventilation systems. Under ideal nutritional and moisture conditions, growth of investigated microorganisms in nutrient broth and on nutrient agar was not inhibited by the inclusion of filter samples or rinse solutions of different filters in the growth medium with one exception. M. luteus and E. coli collected in air filter media and exposed to low air humidity (RH = 30-60%) showed a decline in their viability as a function of time (within 1 h). The decline rate was dependent on the type of bacteria employed and also the filter material itself.

  7. [Electrostatic air filters for dental practice].

    PubMed

    Iversen, D B; Tolo, K

    1975-12-01

    The filtrering effect of an electrostatic filtrattion equipment (Vortronic mod. 75) for air filtration was examined by sampling the air in a general dental practice by means of a Casella Slit Sampler for Airborne Bacteria (C. F. Casella & Co. Ltd., London). A reception, a sterilization, two treatment chairs and a resting cabinet were seperated by 180 cm high walls in a rectangular room of 33 m2 and with an air volume of approximately 80 m3. The staff including one dentist and one or two assistents worked from 8 a.m. till 4 p.m. with a 30 min. lunch break. A mean of 17 patients visited the practice every day. The electrostatic filter was placed in front of one of the treatment chairs and the slit sampler was, for one period, placed at a distance of 5 m from the filter. In the next period both filter and slit sampler were placed within 140 cm from the treatment chair. The air was sampled at noon and at 4 p.m. Micro-organisms from the air samples were cultured on blood agar by incubation at 37 degrees C for 48 hours. After incubation all colonies visible to the eye were counted. A total of 36 air samples were examined. Without filtration of the air the bacterial contamination amounted to 14 cultivable organisms per ft3 air at noon and 54 organisms per ft3 at 4 p.m. The filtration equipment proved to reduce the air contamination to 6 cultivable organisms per ft3. PMID:1060050

  8. DWPF GC FILTER ASSEMBLY SAMPLING AND ANALYSIS

    SciTech Connect

    Bannochie, C.; Imrich, K.

    2009-11-11

    On March 18, 2009 a Defense Waste Processing Facility (DWPF) GC Line Filter Assembly was received at the Savannah River National Laboratory (SRNL). This filter assembly was removed from operation following the completion of Sludge Batch 4 processing in the DWPF. Work on this sample was requested in a Technical Assistance Request. This document reports the pictures, observations, samples collected, and analytical results for the assembly. The assembly arrived at SRNL separated into its three component filters: high efficiency particulate air (HEPA)-1, HEPA-2, and a high efficiency mist evaporator (HEME). Each stage of the assembly's media was sampled and examined visually and by scanning electron microscopy (SEM). Solids built up in the filter housing following the first stage HEME, were dissolved in dilute nitric acid and analyzed by ICP-AES and the undissolved white solids were analyzed by x-ray diffraction (XRD). The vast majority of the material in each of the three stages of the DWPF GC Line Filter Assembly appears to be contaminated with a Hg compound that is {approx}59 wt% Hg on a total solids basis. The Hg species was identified by XRD analysis to contain a mixture of Hg{sub 4}(OH)(NO{sub 3}){sub 3} and Hg{sub 10}(OH){sub 4}(NO{sub 3}){sub 6}. Only in the core sample of the second stage HEPA, did this material appear to be completely covering portions of the filter media, possibly explaining the pressure drops observed by DWPF. The fact that the material migrates through the HEME filter and both HEPA filters, and that it was seen collecting on the outlet side of the HEME filter, would seem to indicate that these filters are not efficient at removing this material. Further SRAT off-gas system modeling should help determine the extent of Hg breakthrough past the Mercury Water Wash Tank (MWWT). The SRAT off-gas system has not been modeled since startup of the facility. Improvements to the efficiency of Hg stripping prior to the ammonia scrubber would seem to be

  9. Interlaboratory evaluation of a standardized inductively coupled plasma mass spectrometry method for the determination of trace beryllium in air filter samples.

    PubMed

    Ashley, Kevin; Brisson, Michael J; Howe, Alan M; Bartley, David L

    2009-12-01

    A collaborative interlaboratory evaluation of a newly standardized inductively coupled plasma mass spectrometry (ICP-MS) method for determining trace beryllium in workplace air samples was carried out toward fulfillment of method validation requirements for ASTM International voluntary consensus standard test methods. The interlaboratory study (ILS) was performed in accordance with an applicable ASTM International standard practice, ASTM E691, which describes statistical procedures for investigating interlaboratory precision. Uncertainty was also estimated in accordance with ASTM D7440, which applies the International Organization for Standardization Guide to the Expression of Uncertainty in Measurement to air quality measurements. Performance evaluation materials (PEMs) used consisted of 37 mm diameter mixed cellulose ester filters that were spiked with beryllium at levels of 0.025 (low loading), 0.5 (medium loading), and 10 (high loading) microg Be/filter; these spiked filters were prepared by a contract laboratory. Participating laboratories were recruited from a pool of over 50 invitees; ultimately, 20 laboratories from Europe, North America, and Asia submitted ILS results. Triplicates of each PEM (blanks plus the three different loading levels) were conveyed to each volunteer laboratory, along with a copy of the draft standard test method that each participant was asked to follow; spiking levels were unknown to the participants. The laboratories were requested to prepare the PEMs by one of three sample preparation procedures (hotplate or microwave digestion or hotblock extraction) that were described in the draft standard. Participants were then asked to analyze aliquots of the prepared samples by ICP-MS and to report their data in units of mu g Be/filter sample. Interlaboratory precision estimates from participating laboratories, computed in accordance with ASTM E691, were 0.165, 0.108, and 0.151 (relative standard deviation) for the PEMs spiked at 0.025, 0

  10. Use of EIChroM TRU RESIN in the determination of Americium, Plutonium and Uranium in air filter and water samples

    SciTech Connect

    Berne, Anna

    1995-03-01

    TRU Resin, an extraction chromatographic material ((octyl (phenyl)-N,Ndiisobutylcarbamoylmethylphosphene oxide (CMPO) dissolved in tributyl phosphate (TBP)) manufactured by EIChroM Industries, was tested for its actinide sorption and desorption characteristics. A study was initiated to demonstrate the effectiveness of extracting plutonium, americium and uranium from water and air filter samples from the Environmental Measurements Laboratory’s Quality Assessment Program (QAP), and the effectiveness of subsequent desorption of one chemical species at a time in order to prepare each of them for spectrometry. Crossover of plutonium into the americium fraction with the TRU Resin was observed and could not be eliminated while using TRU Resin only. However, prior extraction of plutonium using an anion exchange resin can overcome this problem. A method for the determination of americium is proposed which combines the extraction of plutonium onto Bio-Rad AG 1-X8 anion exchange resin with the extraction of americium using the TRU Resin. This method was tested on three triplicate sets of QAP air filters and two triplicate sets of QAP water samples. The recoveries ranged from 70 to 90 percent, and the results were identical to those obtained by the existing methods. The time required to perform the analysis for americium was shortened from 5 weeks to 1 week.

  11. Use of EIChroM`s TRU resin in the determination of americium, plutonium and uranium in air filter and water samples

    SciTech Connect

    Berne, A.

    1995-12-01

    TRU Resin, an extraction chromatographic material (octyl (phenyl)-N,Ndiisobutylcarbamoyl-methylphosphene oxide (CMPO) dissolved in tributyl phosphate (TBP)) manufactured by EIChroM Industries, was tested for its actinide sorption and desorption characteristics. A study was initiated to demonstrate the effectiveness of extracting plutonium, americium and uranium from water and air filter samples from the Environmental Measurements Laboratory`s Quality Assessment Program (QAP), and the effectiveness of subsequent desorption of one chemical species at a time in order to prepare each of them for a spectrometry. Crossover of plutonium into the americium fraction with the TRU Resin was observed and could not be eliminated while using TRU Resin only. However, prior extraction of plutonium using an anion exchange resin can overcome this problem. A method for the determination of americium is proposed which combines the extraction of plutonium onto Bio-Rad AG 1-X8 anion exchange resin with the extraction of americium using the TRU Resin. This method was tested on three triplicate sets of QAP air filters and two triplicate sets of QAP water samples. The recoveries ranged from 70 to 90 percent, and the results were identical to those obtained by the existing methods. The time required to perform the analysis for americium was shortened from 5 weeks to 1 week.

  12. Survival of bacterial and mold spores in air filter media

    NASA Astrophysics Data System (ADS)

    Maus, R.; Goppelsröder, A.; Umhauer, H.

    The present study deals with the survival of bacterial and mold spores ( B. subtilis, A. niger) in new and used air filter media. In an filtration test unit samples of different filter media were challenged with specific microbial aerosols and the viability or survival of the microorganisms collected in the filter media was studied. No notable decline or increase in the viability of B. subtilis in new or used filter samples was observed within 5 days. No differences were observed when filter media were either continuously exposed to air flow or stored under static conditions. No influence of relative humidity (RH=30-85%) on the viability of B. subtilis spores was detected as well. Under ideal humidity conditions (RH>98%) no bacterial growth occurred within all the investigated filter media which is due to the lack of nutrients. Similar results were obtained when employing A. niger spores at low relative humidities (RH<35%). However, in two new filter media the viability declined notably at high relative humidity (RH>85%). This trend is attributed to the combined effect of spore rehydration and diffusion of fiber substances into the spores which rendered the spores prone to air flow and air toxics. Under static conditions in a climatic chamber (RH>98%) abundant mold growth occurred in two filter media. The results indicate that atmospheric dust deposited in air filters may serve as nutrient for molds if humidity is sufficient and filters are not exposed to an air flow.

  13. HEDL air filter examination system software

    SciTech Connect

    Stapleton, E.E.

    1984-10-01

    This document describes the system software and operation of the Hanford Engineering Development Laboratory (HEDL) air filter sample counting systems. Included are a description of how each program functions with flow charts, sample printouts, program listings and a listing with comments of test routines that exercise the hardware. This effort is a result of a work order from HEDL Operational Safety to the Instrument Calibration and Evaluations section of the Pacific Northwest Laboratory (PNL) to upgrade the HEDL counting systems to include standardization, radon subtraction, and detector cooling.

  14. Independent Evaluation of Air Filter Media from Chornobyl

    SciTech Connect

    MD Hoover; AF Fencl; GJ Vargo

    1999-12-21

    An independent evaluation was performed to assess the morphology, pressure drop characteristics, alpha spectroscopy characteristics, and collection efficiency of an air sampling filter media and two types of aerosol face masks provided from Chernobyl by Pacific Northwest National Laboratory. The evaluation included characterizing the filter morphology by scqg electron microscopy; measuring the filter pressure drop as a function of air flowrate; evaluating the spectroscopy characteristics of the filter for alpha-emitting radionuclides by sampling ambient radon progeny aerosols in an Eberline Alpha-6A alpha continuous air monitor; determining the particle collection efficiency of the filter media for 0.3 {micro}m aerodynamic diameter monodisperse particles at 1 and 2 cfm; and comparing the apparent construction, durability, and performance similarities of the filter media to other media commonly used for monitoring airborne alpha-emitting radionuclides.

  15. Temperature Tunable Air-Gap Etalon Filter

    NASA Technical Reports Server (NTRS)

    Krainak, Michael A.; Stephen, Mark A.; Lunt, David L.

    1998-01-01

    We report on experimental measurements of a temperature tuned air-gap etalon filter. The filter exhibits temperature dependent wavelength tuning of 54 pm/C. It has a nominal center wavelength of 532 nm. The etalon filter has a 27 pm optical bandpass and 600 pm free spectral range (finesse approximately 22). The experimental results are in close agreement with etalon theory.

  16. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF METALS FROM SOIL, DUST, AIR FILTER, AND SURFACE AND DERMAL SAMPLES FOR AA (GRAPHITE FURNACE OR FLAME) OR ICP-AES ANALYSIS (BCO-L-3.1)

    EPA Science Inventory

    The purpose of this SOP is to describe the acid digestion of soil, house dust, air filter, and surface or dermal wipe samples for analysis using inductively coupled plasma atomic emissions spectrometry (ICP-AES) and/or graphite furnace atomic absorption spectrometry (GFAAS) or fl...

  17. Aircraft Recirculation Filter for Air-Quality and Incident Assessment

    PubMed Central

    Eckels, Steven J.; Jones, Byron; Mann, Garrett; Mohan, Krishnan R.; Weisel, Clifford P.

    2015-01-01

    The current research examines the possibility of using recirculation filters from aircraft to document the nature of air-quality incidents on aircraft. These filters are highly effective at collecting solid and liquid particulates. Identification of engine oil contaminants arriving through the bleed air system on the filter was chosen as the initial focus. A two-step study was undertaken. First, a compressor/bleed air simulator was developed to simulate an engine oil leak, and samples were analyzed with gas chromatograph-mass spectrometry. These samples provided a concrete link between tricresyl phosphates and a homologous series of synthetic pentaerythritol esters from oil and contaminants found on the sample paper. The second step was to test 184 used aircraft filters with the same gas chromatograph-mass spectrometry system; of that total, 107 were standard filters, and 77 were nonstandard. Four of the standard filters had both markers for oil, with the homologous series synthetic pentaerythritol esters being the less common marker. It was also found that 90% of the filters had some detectable level of tricresyl phosphates. Of the 77 nonstandard filters, 30 had both markers for oil, a significantly higher percent than the standard filters. PMID:25641977

  18. Continuous air monitor filter changeout apparatus

    DOEpatents

    Rodgers, John C.

    2008-07-15

    An apparatus and corresponding method for automatically changing out a filter cartridge in a continuous air monitor. The apparatus includes: a first container sized to hold filter cartridge replacements; a second container sized to hold used filter cartridges; a transport insert connectively attached to the first and second containers; a shuttle block, sized to hold the filter cartridges that is located within the transport insert; a transport driver mechanism means used to supply a motive force to move the shuttle block within the transport insert; and, a control means for operating the transport driver mechanism.

  19. Spacelab J air filter debris analysis

    NASA Technical Reports Server (NTRS)

    Obenhuber, Donald C.

    1993-01-01

    Filter debris from the Spacelab module SLJ of STS-49 was analyzed for microbial contamination. Debris for cabin and avionics filters was collected by Kennedy Space Center personnel on 1 Oct. 1992, approximately 5 days postflight. The concentration of microorganisms found was similar to previous Spacelab missions averaging 7.4E+4 CFU/mL for avionics filter debris and 4.5E+6 CFU/mL for the cabin filter debris. A similar diversity of bacterial types was found in the two filters. Of the 13 different bacterial types identified from the cabin and avionics samples, 6 were common to both filters. The overall analysis of these samples as compared to those of previous missions shows no significant differences.

  20. Enhancing indoor air quality -The air filter advantage.

    PubMed

    Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar

    2015-01-01

    Air pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further reveals a stronger link between, indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. Use of air cleaners and filters are one of the suggested strategies to improve indoor air quality. This review discusses the impact of air pollutants with special focus on indoor air pollutants and the benefits of air filters in improving indoor air quality. PMID:26628762

  1. Enhancing indoor air quality –The air filter advantage

    PubMed Central

    Vijayan, Vannan Kandi; Paramesh, Haralappa; Salvi, Sundeep Santosh; Dalal, Alpa Anil Kumar

    2015-01-01

    Air pollution has become the world's single biggest environmental health risk, linked to around 7 million deaths in 2012 according to a recent World Health Organisation (WHO) report. The new data further reveals a stronger link between, indoor and outdoor air pollution exposure and cardiovascular diseases, such as strokes and ischemic heart disease, as well as between air pollution and cancer. The role of air pollution in the development of respiratory diseases, including acute respiratory infections and chronic obstructive pulmonary diseases, is well known. While both indoor and outdoor pollution affect health, recent statistics on the impact of household indoor pollutants (HAP) is alarming. The WHO factsheet on HAP and health states that 3.8 million premature deaths annually - including stroke, ischemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. Use of air cleaners and filters are one of the suggested strategies to improve indoor air quality. This review discusses the impact of air pollutants with special focus on indoor air pollutants and the benefits of air filters in improving indoor air quality. PMID:26628762

  2. Carbon fiber composite molecular sieve electrically regenerable air filter media

    DOEpatents

    Wilson, K.A.; Burchell, T.D.; Judkins, R.R.

    1998-10-27

    An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply air stream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium. 3 figs.

  3. Air-conditioner filters enriching dust mites allergen.

    PubMed

    Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

    2015-01-01

    We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens. PMID:26064381

  4. Air-conditioner filters enriching dust mites allergen

    PubMed Central

    Zhan, Xiaodong; Li, Chaopin; Xu, Haifeng; Xu, Pengfei; Zhu, Haibin; Diao, Jidong; Li, Na; Zhao, Beibei

    2015-01-01

    We detected the concentration of dust mites allergen (Der f1 & Der p1) in the air of different places before and after the starting of air-conditioners in Wuhu City, Anhui, China, and to discuss the relation between the dust mites allergen in air-conditioner filters and the asthma attack. The dust samples were collected from the air-conditioner filters in dining rooms, shopping malls, hotels and households respectively. Concentrations of dust mites major group allergen 1 (Der f 1, Der p1) were detected with enzyme linked immunosorbent assay (ELISA), and the dust mite immune activities were determined by dot-ELISA. The concentration of Der f1 in dining rooms, shopping malls, hotels and households was 1.52 μg/g, 1.24 μg/g, 1.31 μg/g and 1.46 μg/g respectively, and the concentration of Der p1 in above-mentioned places was 1.23 μg/g, 1.12 μg/g, 1.16 μg/g and 1.18 μg/g respectively. The concentration of Der f1 & Der p1 in air was higher after the air-conditioners starting one hours later, and the difference was significant (P<0.05, respectively). Additionally, dot-ELISA findings revealed that the allergen extracted from the dust was capable of reacting with IgE from the sera of asthma mice allergic to dust mites. The study concludes that air-conditioner filters can enrich dust mites major group allergen, and the allergens can induce asthma. The air-conditioner filters shall be cleaned or replaced regularly to prevent or reduce accumulation of the dust mites and its allergens. PMID:26064381

  5. Laboratory experiments on membrane filter sampling of airborne mycotoxins produced by Stachybotrys atra corda

    NASA Astrophysics Data System (ADS)

    Pasanen, A.-L.; Nikulin, M.; Tuomainen, M.; Berg, S.; Parikka, P.; Hintikka, E.-L.

    A membrane filter method for sampling of airborne stachybotrystoxins was studied in the laboratory. Toxigenic strains of Stachybotrys atra on wallpaper, grain, hay and straw were used as toxin sources in the experiments. Air samples were collected on cellulose nitrate and polycarbonate membrane filters at air flow rates of 10-20 ℓ min -1. After the filter sampling, the air was passed through methanol. The results showed that stachybotrystoxins (trichothecenes) were concentrated in airborne fungal propagules, and thus can be collected on filters. Polycarbonate filters with a pore size of 0.2 μm collected the highest percentage of toxic samples. The laboratory experiments indicated that polycarbonate filter sampling for the collection of airborne mycotoxins is a promising method for extension to field measurements.

  6. Carbon fiber composite molecular sieve electrically regenerable air filter media

    DOEpatents

    Wilson, Kirk A.; Burchell, Timothy D.; Judkins, Roddie R.

    1998-01-01

    An electrically regenerable gas filter system includes a carbon fiber composite molecular sieve (CFCMS) filter medium. After a separate medium-efficiency pre-filter removes particulate from the supply airstream, the CFCMS filter sorbs gaseous air pollutants before the air is recirculated to the space. When saturated, the CFCMS media is regenerated utilizing a low-voltage current that is caused to pass through the filter medium.

  7. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, K.H.

    1987-12-10

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  8. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, Katharine H.

    1990-01-01

    An inertial impactor to be used in an air sampling device for collection of respirable size particles in ambient air which may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry.

  9. Inertial impaction air sampling device

    DOEpatents

    Dewhurst, K.H.

    1990-05-22

    An inertial impactor is designed which is to be used in an air sampling device for collection of respirable size particles in ambient air. The device may include a graphite furnace as the impaction substrate in a small-size, portable, direct analysis structure that gives immediate results and is totally self-contained allowing for remote and/or personal sampling. The graphite furnace collects suspended particles transported through the housing by means of the air flow system, and these particles may be analyzed for elements, quantitatively and qualitatively, by atomic absorption spectrophotometry. 3 figs.

  10. Evaluating Radionuclide Air Emission Stack Sampling Systems

    SciTech Connect

    Ballinger, Marcel Y.

    2002-12-16

    The Pacific Northwest National Laboratory (PNNL) operates a number of research and development (R&D) facilities for the U.S. Department of Energy at the Hanford Site, Washington. These facilities are subject to Clean Air Act regulations that require sampling of radionuclide air emissions from some of these facilities. A revision to an American National Standards Institute (ANSI) standard on sampling radioactive air emissions has recently been incorporated into federal and state regulations and a re-evaluation of affected facilities is being performed to determine the impact. The revised standard requires a well-mixed sampling location that must be demonstrated through tests specified in the standard. It also carries a number of maintenance requirements, including inspections and cleaning of the sampling system. Evaluations were performed in 2000 – 2002 on two PNNL facilities to determine the operational and design impacts of the new requirements. The evaluation included inspection and cleaning maintenance activities plus testing to determine if the current sampling locations meet criteria in the revised standard. Results show a wide range of complexity in inspection and cleaning activities depending on accessibility of the system, ease of removal, and potential impact on building operations (need for outages). As expected, these High Efficiency Particulate Air (HEPA)-filtered systems did not show deposition significant enough to cause concerns with blocking of the nozzle or other parts of the system. The tests for sampling system location in the revised standard also varied in complexity depending on accessibility of the sample site and use of a scale model can alleviate many issues. Previous criteria to locate sampling systems at eight duct diameters downstream and two duct diameters upstream of the nearest disturbances is no guarantee of meeting criteria in the revised standard. A computational fluid dynamics model was helpful in understanding flow and

  11. REGIONAL AIR POLLUTION STUDY. HIGH VOLUME FILTER MEASUREMENTS OF SUSPENDED PARTICULATE MATTER

    EPA Science Inventory

    Ten of the 25 stations making up the Regional Air Monitoring System were equipped with dichotomous samplers and high volume filter samplers for aerosol measurements. The high volume samplers collected samples every third day for 24-hour periods (0000-2400). Sample filters were re...

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

    DOEpatents

    Phillips, Terrance D.; Edwards, Howard D.

    1999-01-01

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

  13. EML Surface Air Sampling Program, 1990--1993 data

    SciTech Connect

    Larsen, R.J.; Sanderson, C.G.; Kada, J.

    1995-11-01

    Measurements of the concentrations of specific atmospheric radionuclides in air filter samples collected for the Environmental Measurements Laboratory`s Surface Air Sampling Program (SASP) during 1990--1993, with the exception of April 1993, indicate that anthropogenic radionuclides, in both hemispheres, were at or below the lower limits of detection for the sampling and analytical techniques that were used to collect and measure them. The occasional detection of {sup 137}Cs in some air filter samples may have resulted from resuspension of previously deposited debris. Following the April 6, 1993 accident and release of radionuclides into the atmosphere at a reprocessing plant in the Tomsk-7 military nuclear complex located 16 km north of the Siberian city of Tomsk, Russia, weekly air filter samples from Barrow, Alaska; Thule, Greenland and Moosonee, Canada were selected for special analyses. The naturally occurring radioisotopes that the authors measure, {sup 7}Be and {sup 210}Pb, continue to be detected in most air filter samples. Variations in the annual mean concentrations of {sup 7}Be at many of the sites appear to result primarily from changes in the atmospheric production rate of this cosmogenic radionuclide. Short-term variations in the concentrations of {sup 7}Be and {sup 210}Pb continued to be observed at many sites at which weekly air filter samples were analyzed. The monthly gross gamma-ray activity and the monthly mean surface air concentrations of {sup 7}Be, {sup 95}Zr, {sup 137}Cs, {sup 144}Ce, and {sup 210}Pb measured at sampling sites in SASP during 1990--1993 are presented. The weekly mean surface air concentrations of {sup 7}Be, {sup 95}Zr, {sup 137}Cs, {sup 144}Ce, and {sup 210}Pb for samples collected during 1990--1993 are given for 17 sites.

  14. Air Sampling System Evaluation Template

    2000-05-09

    The ASSET1.0 software provides a template with which a user can evaluate an Air Sampling System against the latest version of ANSI N13.1 "Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stacks and Ducts of Nuclear Facilities". The software uses the ANSI N13.1 PIC levels to establish basic design criteria for the existing or proposed sampling system. The software looks at such criteria as PIC level, type of radionuclide emissions, physical state ofmore » the radionuclide, nozzle entrance effects, particulate transmission effects, system and component accuracy and precision evaluations, and basic system operations to provide a detailed look at the subsystems of a monitoring and sampling system/program. A GAP evaluation can then be completed which leads to identification of design and operational flaws in the proposed systems. Corrective measures can then be limited to the GAPs.« less

  15. 122. View in subway showing air filters for unit turbinegenerator ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    122. View in subway showing air filters for unit turbine-generator unit no. 3; looking north. To the left is opening through wall which brings fresh air into the filters; this opening is above the tailrace. Photo by Jet Lowe, HAER, 1989. - Puget Sound Power & Light Company, White River Hydroelectric Project, 600 North River Avenue, Dieringer, Pierce County, WA

  16. The high efficiency steel filters for nuclear air cleaning

    SciTech Connect

    Bergman, W.; Larsen, G.; Lopez, R.; Williams, K.; Violet, C.

    1990-08-01

    We have, in cooperation with industry, developed high-efficiency filters made from sintered stainless-steel fibers for use in several air-cleaning applications in the nuclear industry. These filters were developed to overcome the failure modes in present high-efficiency particulate air (HEPA) filters. HEPA filters are made from glass paper and glue, and they may fail when they get hot or wet and when they are overpressured. In developing our steel filters, we first evaluated the commercially available stainless-steel filter media made from sintered powder and sintered fiber. The sintered-fiber media performed much better than sintered-powder media, and the best media had the smallest fiber diameter. Using the best media, we then built prototype filters for venting compressed gases and evaluated them in our automated filter tester. 12 refs., 20 figs.

  17. Theory and applications of sampled analog recursive CTD comb filters

    NASA Technical Reports Server (NTRS)

    Tao, T. F.; Holmes, S. V.; Ejaz, A.; Piazza, F.; Saetre, L. T.; Freund, B.

    1976-01-01

    Sampled analog comb filter using a recursive filter implementation was studied. Charge transfer device delay lines were used as the delay elements. The similarities and differences between sampled analog recursive filter and digital recursive filter were pointed out. Both canceller type and integrator type comb filter using the first order or the second order canonical circuits were studied. Experimental results of frequency response are presented to show their difference from that of digital filters. A theoretical analysis was presented based essentially on the digital filter theory but modified to take into account the differences described above. The usefulness of this theory in analyzing the comb filter characteristics was discussed. Several applications of both the canceller type comb filter and the integrator type comb filter were demonstrated.

  18. Evaluation of Filters for Removal of Bacteriophages from Air1

    PubMed Central

    Washam, C. J.; Black, C. H.; Sandine, W. E.; Elliker, P. R.

    1966-01-01

    Glass wool, nonabsorbent cotton, fiberglass filter medium, and a commercial absolute filter were tested for effectiveness in removing aerosolized bacterial viruses under low flow rate (1 ft3/min) and high flow rate (10 to 25 ft3/min) air-flow conditions. Special equipment was designed for measurement of filter efficiencies under the two air-flow conditions. Under low air-flow rate test conditions, glass wool was only 98.543 to 99.83% efficient, whereas cotton (five layers), fiberglass medium (three layers), and the commercial absolute filter were at least 99.900, 99.999, and 99.999 efficient, respectively. Glass wool and cotton were not used under higher air-flow conditions because they were difficult to assemble in leak-tight filters. The commercial absolute filter and fiberglass medium (three layers) were at least 99.990 and 99.999% efficient, respectively, under the higher air flow conditions. A stainless-steel filter of simple design and fitted with three layers of fiberglass medium was found to be greater than 99.999% efficient in removing high concentrations (20,000 to 70,000 plaque-forming units per cubic foot) of aerosolized bacteriophages from air moving at a low flow rate (1 ft3/min). Use of this filter on pressure-vacuum tanks in the fermentation industry is suggested. Several other uses of such a filter are proposed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:5927020

  19. Digital Integrate-And-Dump Filter With Offset Sampling

    NASA Technical Reports Server (NTRS)

    Sadr, R.; Hurd, W. J.

    1989-01-01

    Detection of weak signals improved slightly. Digital integrate-and-dump filter proposed for detection of weak rectangular-pulse signals corrupted by additive white Gaussian noise. Theory of filter takes account of degradation of performance caused by offset sampling.

  20. Efficiency of dust sampling inlets in calm air.

    PubMed

    Breslin, J A; Stein, R L

    1975-08-01

    Measurement of airborne dust concentrations usually involves drawing a sample of the dust-laden air into the measuring instrument through an inlet. Even if the surrounding air is calm, theoretical calculations predict that large particles may not be sampled accurately due to the combined effects of gravity and inertia on the particles near the sampling inlet. Tests were conducted to determine the conditions of particle size, inlet radius, and flow rare necessary for accurate dust sampling. A coal-dust aerosol was sampled simultaneously through inlets of different diameters at the same volume flow-rate and collected on filters. The dust was removed from the filters and the particles were counted and sized with a Coulter counter. Results showed that published criteria for inlet conditions for correct sampling are overly restrictive and that respirable-size particles are sampled correctly in the normal range or operation of most dust sampling instruments. PMID:1227283

  1. A continuous sampling air-ICP for metals emission monitoring

    SciTech Connect

    Baldwin, D.P.; Zamzow, D.S.; Eckels, D.E.; Miller, G.P.

    1999-09-19

    An air-inductively coupled plasma (air-ICP) system has been developed for continuous sampling and monitoring of metals as a continuous emission monitor (CEM). The plasma is contained in a metal enclosure to allow reduced-pressure operation. The enclosure and plasma are operated at a pressure slightly less than atmospheric using a Roots blower, so that sample gas is continuously drawn into the plasma. A Teflon sampling chamber, equipped with a sampling pump, is connected to the stack that is to be monitored to isokinetically sample gas from the exhaust line and introduce the sample into the air-ICP. Optical emission from metals in the sampled gas stream is detected and monitored using an acousto-optic tunable filter (AOTF)--echelle spectrometer system. A description of the continuous sampling air-ICP system is given, along with some preliminary laboratory data for continuous monitoring of metals.

  2. Continuous sampling air-ICP for metals emission monitoring

    NASA Astrophysics Data System (ADS)

    Baldwin, David P.; Zamzow, Daniel S.; Eckels, David E.; Miller, George P.

    1999-12-01

    An air-inductively coupled plasma (air-ICP) system has been developed for continuous sampling and monitoring of metals as a continuous emission monitor (CEM). The plasma is contained in a metal enclosure to allow reduced-pressure operation. The enclosure and plasma are operated at a pressure slightly less than atmospheric using a Roots blower, so that sample gas is continuously drawn into the plasma. A Teflon sampling chamber, equipped with a sampling pump, is connected to the stack that is to be monitored to isokinetically sample gas from the exhaust line and introduce the sample into the air-ICP. Optical emission from metals in the sampled gas stream is detected and monitored using an acousto-optic tunable filter (AOTF)-echelle spectrometer system. A description of the continuous sampling air-ICP system is given, along with some preliminary laboratory data for continuous monitoring of metals.

  3. Are Ventilation Filters Degrading Indoor Air Quality in California Classrooms?

    SciTech Connect

    Fisk, William J.; Destaillats, H.; Apte, M.G.; Destaillats,, Hugo; Fisk, Michael G. Apte and William J.

    2008-10-01

    Heating, ventilating, and cooling classrooms in California consume substantial electrical energy. Indoor air quality (IAQ) in classrooms affects studenthealth and performance. In addition to airborne pollutants that are emitted directly by indoor sources and those generated outdoors, secondary pollutants can be formed indoors by chemical reaction of ozone with other chemicals and materials. Filters are used in nearly all classroom heating, ventilation and air?conditioning (HVAC) systems to maintain energy-efficient HVAC performance and improve indoor air quality; however, recent evidence indicates that ozone reactions with filters may, in fact, be a source of secondary pollutants. This project quantitatively evaluated ozone deposition in HVAC filters and byproduct formation, and provided a preliminary assessment of the extent towhich filter systems are degrading indoor air quality. The preliminary information obtained will contribute to the design of subsequent research efforts and the identification of energy efficient solutions that improve indoor air quality in classrooms and the health and performance of students.

  4. Electrostatic air filters generated by electric fields

    SciTech Connect

    Bergman, W.; Biermann, A.H.; Hebard, H.D.; Lum, B.Y.; Kuhl, W.D.

    1981-01-27

    This paper presents theoretical and experimental findings on fibrous filters converted to electrostatic operation by a nonionizing electric field. Compared to a conventional fibrous filter, the electrostatic filter has a higher efficiency and a longer, useful life. The increased efficiency is attributed to a time independent attraction between polarized fibers and charged, polarized particles and a time dependent attraction between charged fibers and charged, polarized particles. The charge on the fibers results from a dynamic process of charge accumulation due to the particle deposits and a charge dissipation due to the fiber conductivity.

  5. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF METALS FROM SOIL, DUST, AIR FILTER, AND SURFACE AND DERMAL WIPE SAMPLES FOR AA (GRAPHITE FURNACE OR FLAME) OR ICP-AES ANALYSIS (BCO-L-3.1)

    EPA Science Inventory

    The purpose of this SOP is to describe the acid digestion of soil, house dust, air filter, and surface or dermal wipe samples for analysis using inductively coupled plasma atomic emissions spectrometry (ICP-AES) and/or graphite furnace atomic absorption spectrometry (GFAAS) or fl...

  6. Independent Evaluaton of Air Filter Media From Chornobyl

    SciTech Connect

    Hoover, Mark D.; Fencl, Alice F.; Vargo, George J.

    1999-09-10

    Independent Evaluation of Air Filter Media from Chornobyl Research performed for the U.S. Department of Energy under Cooperative Agreement DE-FC04-96AL76406 Edited by Lovelace Respiratory Research Institute

  7. Air sampling in the workplace. Final report

    SciTech Connect

    Hickey, E.E.; Stoetzel, G.A.; Strom, D.J.; Cicotte, G.R.; Wiblin, C.M.; McGuire, S.A.

    1993-09-01

    This report provides technical information on air sampling that will be useful for facilities following the recommendations in the NRC`s Regulatory Guide 8.25, Revision 1, ``Air sampling in the Workplace.`` That guide addresses air sampling to meet the requirements in NRC`s regulations on radiation protection, 10 CFR Part 20. This report describes how to determine the need for air sampling based on the amount of material in process modified by the type of material, release potential, and confinement of the material. The purposes of air sampling and how the purposes affect the types of air sampling provided are discussed. The report discusses how to locate air samplers to accurately determine the concentrations of airborne radioactive materials that workers will be exposed to. The need for and the methods of performing airflow pattern studies to improve the accuracy of air sampling results are included. The report presents and gives examples of several techniques that can be used to evaluate whether the airborne concentrations of material are representative of the air inhaled by workers. Methods to adjust derived air concentrations for particle size are described. Methods to calibrate for volume of air sampled and estimate the uncertainty in the volume of air sampled are described. Statistical tests for determining minimum detectable concentrations are presented. How to perform an annual evaluation of the adequacy of the air sampling is also discussed.

  8. Methodology for Modeling the Microbial Contamination of Air Filters

    PubMed Central

    Joe, Yun Haeng; Yoon, Ki Young; Hwang, Jungho

    2014-01-01

    In this paper, we propose a theoretical model to simulate microbial growth on contaminated air filters and entrainment of bioaerosols from the filters to an indoor environment. Air filter filtration and antimicrobial efficiencies, and effects of dust particles on these efficiencies, were evaluated. The number of bioaerosols downstream of the filter could be characterized according to three phases: initial, transitional, and stationary. In the initial phase, the number was determined by filtration efficiency, the concentration of dust particles entering the filter, and the flow rate. During the transitional phase, the number of bioaerosols gradually increased up to the stationary phase, at which point no further increase was observed. The antimicrobial efficiency and flow rate were the dominant parameters affecting the number of bioaerosols downstream of the filter in the transitional and stationary phase, respectively. It was found that the nutrient fraction of dust particles entering the filter caused a significant change in the number of bioaerosols in both the transitional and stationary phases. The proposed model would be a solution for predicting the air filter life cycle in terms of microbiological activity by simulating the microbial contamination of the filter. PMID:24523908

  9. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - STANDARD FILTER CORPORATION PE16ZU FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  10. Evaluation of biological air filters for livestock ventilation air by membrane inlet mass spectrometry.

    PubMed

    Feilberg, Anders; Adamsen, Anders P S; Lindholst, Sabine; Lyngbye, Merete; Schäfer, Annette

    2010-01-01

    Biological air filters have been proposed as a cost-effective technology for reducing odor emissions from intensive swine production facilities. In this work we present results from the application of membrane inlet mass spectrometry (MIMS) for continuously monitoring the removal of odorous compounds in biological air filters. The sensitivity and selectivity were tested on synthetic samples of selected odorous compounds, and linearity and detection limits in the lower ppb range were demonstrated for all compounds tested (methanethiol, dimethyl sulfide, carboxylic acids, 4-methylphenol, aldehydes, indole, and skatole) except trimethylamine. The method was applied in situ at two full-scale filters installed at swine houses. The results have been compared with analyses by thermal desorption gas chromatography-mass spectrometry (TD-GC/MS), and odor was measured by olfactometry. By comparison with TD-GC/MS, observed MIMS signals were assigned to 4-methylphenol, 4-ethylphenol, indole, skatole, the sum of volatile reduced organic sulfur compounds (ROS), and three subgroups of carboxylic acids. The removal rates were observed to be related to air-water partitioning with removal efficiencies in the range of 0 to 50% for low-soluble organic sulfur compounds and high removal efficiencies (typically 80-100%) for more soluble phenols and carboxylic acids. Based on the results and published odor threshold values, it is estimated that the low removal efficiency of ROS is the main limitation for achieving a higher odor reduction. PMID:20400604

  11. Magnetic analyses of powders from exhausted cabin air filters

    NASA Astrophysics Data System (ADS)

    Winkler, Aldo; Sagnotti, Leonardo

    2013-04-01

    The automotive cabin air filter is a pleated-paper filter placed in the outside-air intake for the car's passenger compartment. Dirty and saturated cabin air filters significantly reduce the airflow from the outside and introduce particulate matter (PM) and allergens (for example, pollen) into the cabin air stream. Magnetic measurements and analyses have been carried out on powders extracted from exhausted cabin air filters to characterize their magnetic properties and to compare them to those already reported for powders collected from disk brakes, gasoline exhaust pipes and Quercus ilex leaves. This study is also aimed at the identification and quantification of the contribution of the ultrafine fraction, superparamagnetic (SP) at room temperature, to the overall magnetic properties of these powders. This contribution was estimated by interpreting and comparing data from FORCs, isothermal remanent magnetization vs time decay curves, frequency and field dependence of the magnetic susceptibility and out-of-phase susceptibility. The magnetic properties and the distribution of the SP particles are generally homogenous and independent of the brand of the car, of the model of the filter and of its level of usage. The relatively high concentration of magnetic PM trapped in these filters poses relevant questions about the air quality inside a car.

  12. A simple novel device for air sampling by electrokinetic capture

    DOE PAGESBeta

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

    2015-12-27

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

  13. A simple novel device for air sampling by electrokinetic capture

    SciTech Connect

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

    2015-12-27

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

  14. Gross Alpha Beta Radioactivity in Air Filters Measured by Ultra Low Level α/β Counter

    NASA Astrophysics Data System (ADS)

    Cfarku, Florinda; Bylyku, Elida; Deda, Antoneta; Dhoqina, Polikron; Bakiu, Erjona; Perpunja, Flamur

    2010-01-01

    Study of radioactivity in air as very important for life is done regularly using different methods in every country. As a result of nuclear reactors, atomic centrals, institutions and laboratories, which use the radioactivity substances in open or closed sources, there are a lot radioactive wastes. Mixing of these wastes after treatment with rivers and lakes waters makes very important control of radioactivity. At the other side nuclear and radiological accidents are another source of the contamination of air and water. Due to their radio toxicity, especially those of Sr90, Pu239, etc. a contamination hazard for human begins exist even at low concentration levels. Measurements of radioactivity in air have been performed in many parts of the world mostly for assessment of the doses and risk resulting from consuming air. In this study we present the results of international comparison organized by IAEA Vienna, Austria for the air filters spiked with unknown Alpha and Beta Activity. For the calibration of system we used the same filters spiked: a) with Pu-239 as alpha source; b) Sr-90 as beta source and also the blank filter. The measurements of air filter samples after calibration of the system are done with Ultra Low Level α/β Counter (MPC 9604) Protean Instrument Corporation. The high sensitivity of the system for the determination of the Gross Alpha and Beta activity makes sure detection of low values activity of air filters. Our laboratory results are: Aα = (0.19±0.01) Bq/filter and Aα (IAEA) = (0.17±0.009) Bq/filter; Aβ = (0.33±0.009) Bq/filter and Aβ (IAEA) = (0.29±0.01) Bq/filter. As it seems our results are in good agreement with reference values given by IAEA (International Atomic Energy Agency).

  15. Gross Alpha Beta Radioactivity in Air Filters Measured by Ultra Low Level alpha/beta Counter

    SciTech Connect

    Cfarku, Florinda; Bylyku, Elida; Bakiu, Erjona; Perpunja, Flamur; Deda, Antoneta; Dhoqina, Polikron

    2010-01-21

    Study of radioactivity in air as very important for life is done regularly using different methods in every country. As a result of nuclear reactors, atomic centrals, institutions and laboratories, which use the radioactivity substances in open or closed sources, there are a lot radioactive wastes. Mixing of these wastes after treatment with rivers and lakes waters makes very important control of radioactivity. At the other side nuclear and radiological accidents are another source of the contamination of air and water. Due to their radio toxicity, especially those of Sr{sup 90}, Pu{sup 239}, etc. a contamination hazard for human begins exist even at low concentration levels. Measurements of radioactivity in air have been performed in many parts of the world mostly for assessment of the doses and risk resulting from consuming air. In this study we present the results of international comparison organized by IAEA Vienna, Austria for the air filters spiked with unknown Alpha and Beta Activity. For the calibration of system we used the same filters spiked: a) with Pu-239 as alpha source; b) Sr-90 as beta source and also the blank filter. The measurements of air filter samples after calibration of the system are done with Ultra Low Level alpha/beta Counter (MPC 9604) Protean Instrument Corporation. The high sensitivity of the system for the determination of the Gross Alpha and Beta activity makes sure detection of low values activity of air filters. Our laboratory results are: Aalpha = (0.19+-0.01) Bq/filter and Aalpha(IAEA) = (0.17+-0.009) Bq/filter; A{sub b}eta = (0.33+-0.009) Bq/filter and A{sub b}eta (IAEA) = (0.29+-0.01) Bq/filter. As it seems our results are in good agreement with reference values given by IAEA (International Atomic Energy Agency).

  16. High efficiency, down flow air filter sealing and support system

    SciTech Connect

    Mattison, A.H.

    1986-07-15

    An assembly of high efficiency air filter units through which essentially all air entering a clean space below the units must pass to remove particulate matter down to sub-micron size from the air, the assembly comprising: (a) a plurality of air filter units each having a filter core of pleated media sealed in air-tight engagement on four sides to a surrounding, box-like, rigid frame, having side and end members; (b) means for supporting the filter units adjacent the upper surfaces thereof from structure above the space with adjacent units having the side and end members thereof providing adjoining vertical surfaces in closely spaced relation with the lower surfaces of the units in essentially the same horizontal plane to form at least a portion of the top of the space; and (c) a caulking material filling all spaces between the adjoining vertical surfaces of adjacent filter units, effectively sealing the spaces and providing the sole means preventing passage of air around the units.

  17. Effect of Intake Air Filter Condition on Vehicle Fuel Economy

    SciTech Connect

    Norman, Kevin M; Huff, Shean P; West, Brian H

    2009-02-01

    The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a study aimed specifically at the effect of engine air filter condition on fuel economy. The goal of this study was to explore the effects of a clogged air filter on the fuel economy of vehicles operating over prescribed test cycles. Three newer vehicles (a 2007 Buick Lucerne, a 2006 Dodge Charger, and a 2003 Toyota Camry) and an older carbureted vehicle were tested. Results show that clogging the air filter has no significant effect on the fuel economy of the newer vehicles (all fuel injected with closed-loop control and one equipped with MDS). The engine control systems were able to maintain the desired AFR regardless of intake restrictions, and therefore fuel consumption was not increased. The carbureted engine did show a decrease in

  18. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 8 2011-07-01 2011-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34...

  19. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 9 2014-07-01 2014-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34...

  20. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  1. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  2. 40 CFR 61.34 - Air sampling.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Air sampling. 61.34 Section 61.34 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Beryllium § 61.34...

  3. Air sampling filtration media: Collection efficiency for respirable size-selective sampling

    PubMed Central

    Soo, Jhy-Charm; Monaghan, Keenan; Lee, Taekhee; Kashon, Mike; Harper, Martin

    2016-01-01

    The collection efficiencies of commonly used membrane air sampling filters in the ultrafine particle size range were investigated. Mixed cellulose ester (MCE; 0.45, 0.8, 1.2, and 5 μm pore sizes), polycarbonate (0.4, 0.8, 2, and 5 μm pore sizes), polytetrafluoroethylene (PTFE; 0.45, 1, 2, and 5 μm pore sizes), polyvinyl chloride (PVC; 0.8 and 5 μm pore sizes), and silver membrane (0.45, 0.8, 1.2, and 5 μm pore sizes) filters were exposed to polydisperse sodium chloride (NaCl) particles in the size range of 10–400 nm. Test aerosols were nebulized and introduced into a calm air chamber through a diffusion dryer and aerosol neutralizer. The testing filters (37 mm diameter) were mounted in a conductive polypropylene filter-holder (cassette) within a metal testing tube. The experiments were conducted at flow rates between 1.7 and 11.2 l min−1. The particle size distributions of NaCl challenge aerosol were measured upstream and downstream of the test filters by a scanning mobility particle sizer (SMPS). Three different filters of each type with at least three repetitions for each pore size were tested. In general, the collection efficiency varied with airflow, pore size, and sampling duration. In addition, both collection efficiency and pressure drop increased with decreased pore size and increased sampling flow rate, but they differed among filter types and manufacturer. The present study confirmed that the MCE, PTFE, and PVC filters have a relatively high collection efficiency for challenge particles much smaller than their nominal pore size and are considerably more efficient than polycarbonate and silver membrane filters, especially at larger nominal pore sizes. PMID:26834310

  4. Development of Refrigerant Change Indicator and Dirty Air Filter Sensor

    SciTech Connect

    Mei, V.

    2003-06-24

    The most common problems affecting residential and light commercial heating, ventilation, and air-conditioning (HVAC) systems are slow refrigerant leaks and dirty air filters. Equipment users are usually not aware of a problem until most of the refrigerant has escaped or the air filter is clogged with dirt. While a dirty air filter can be detected with a technology based on the air pressure differential across the filter, such as a ''whistling'' indicator, it is not easy to incorporate this technology into existing HVAC diagnostic equipment. Oak Ridge National Laboratory is developing a low-cost, nonintrusive refrigerant charge indicator and dirty air filter detection sensor. The sensors, based on temperature measurements, will be inexpensive and easy to incorporate into existing heat pumps and air conditioners. The refrigerant charge indicator is based on the fact that when refrigerant starts to leak, the evaporator coil temperature starts to drop and the level of liquid subcooling drops. When the coil temperature or liquid subcooling drops below a preset reading, a signal, such as a yellow warning light, can be activated to warn the equipment user that the system is undercharged. A further drop of coil temperature or liquid subcooling below another preset reading would trigger a second warning signal, such as a red warning light, to warn the equipment user that the unit now detects a leak and immediate action should be taken. The warning light cannot be turned off until it is re-set by a refrigeration repairman. To detect clogged air filters, two additional temperature sensors can be applied, one each across the evaporator. When the air filter is accumulating buildup, the temperature differential across the evaporator will increase because of the reduced airflow. When the temperature differential reaches a pre-set reading, a signal will be sent to the equipment user that the air filter needs to be changed. A traditional refrigerant charge indicator requires

  5. Efficiency of Sampling and Analysis of Asbestos Fibers on Filter Media: Implications for Exposure Assessment

    EPA Science Inventory

    To measure airborne asbestos and other fibers, an air sample must represent the actual number and size of fibers. Typically, mixed cellulose ester (MCE, 0.45 or 0.8 µm pore size) and to a much lesser extent, capillary-pore polycarbonate (PC, 0.4 µm pore size) membrane filters are...

  6. Magnetic evaluation of TSP-filters for air quality monitoring

    NASA Astrophysics Data System (ADS)

    Castañeda-Miranda, Ana Gabriela; Böhnel, Harald N.; Molina-Garza, Roberto S.; Chaparro, Marcos A. E.

    2014-10-01

    We present the magnetic properties of the powders collected by high volume total suspended particle air samplers used to monitor atmospheric pollution in Santiago de Querétaro, a city of one million people in central Mexico. The magnetic measurements have been combined with scanning electron microscopy observations and analysis, in order to characterize the particles captured in the filters as natural and anthropogenic. The main goal of the study is to test if magnetic measurements on the sampled atmospheric dust can be effective, low-cost, proxy to qualitatively estimate the air quality, complementing the traditional analytical methods. The magnetic properties of the powder collected in the filters have been investigated measuring the low field magnetic susceptibility, hysteresis loops, thermomagnetic curves, and isothermal remanent magnetization. The rock magnetism data have been supplemented by energy-dispersive X-ray spectroscopy analysis and Raman spectroscopy. It was found that the main magnetic carrier is low-Ti magnetite in the PSD range with a contribution from SP particles, and small but significant contributions from hematite, maghemite and goethite particles. Total suspended particles in the atmosphere during the monitored days ranged between about 30 and 280 μg/m3. Magnetic susceptibility values are well correlated with the independently determined total suspended particles concentration (R = 0.93), but particle concentration does not correlate as well with IRM1T. This may be attributed to contributions from SP and paramagnetic particles to the susceptibility signal, but not to the remanence. The effects of climate in particle size, composition and concentration were considered in terms of precipitation and wind intensity, but they are actually minor. The main effect of climate appears to be the removal of SP particles during rainy days. There is a contribution to air pollution from natural mineral sources, which we attribute to low vegetation cover

  7. AMERICAN AIR FILTER KINPACTOR 10 X 56 VENTURI SCRUBBER EVALUATION

    EPA Science Inventory

    The report gives results of an evaluation of an American Air Filter Kinpactor 10 x 56 venturi scrubber, operating on emissions from a large borax fusing furnace. Average total efficiency was 97.5% during the test period. The venturi was operated at a pressure drop of 110 cm W. C....

  8. 36. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" AIR FILTERS LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. FIFTH FLOOR BLDG. 27, "CLEAN ROOM" AIR FILTERS LOOKING SOUTH. - Fafnir Bearing Plant, Bounded on North side by Myrtle Street, on South side by Orange Street, on East side by Booth Street & on West side by Grove Street, New Britain, Hartford County, CT

  9. BIOLOGICAL WASTE AIR TREATMENT IN BIOTRICKLING FILTERS. (R825392)

    EPA Science Inventory

    Abstract

    Recent studies in the area of biological waste air treatment in biotrickling filters have addressed fundamental key issues, such as biofilm architecture, microbiology of the process culture and means to control accumulation of biomass. The results from these s...

  10. BIASES IN CASTNET FILTER PACK RESULTS ASSOCIATED WITH SAMPLING PROTOCOL

    EPA Science Inventory

    In the current study, single filter weekly (w) results are compared with weekly results aggregated from day and night (dn) weekly samples. Comparisons of the two sampling protocols for all major constituents (SO42-, NO3-, NH4+, HNO3, and SO2) show median bias (MB) of < 5 nmol m-3...

  11. Preparation, certification and interlaboratory analysis of workplace air filters spiked with high-fired beryllium oxide.

    PubMed

    Oatts, Thomas J; Hicks, Cheryl E; Adams, Amy R; Brisson, Michael J; Youmans-McDonald, Linda D; Hoover, Mark D; Ashley, Kevin

    2012-02-01

    Occupational sampling and analysis for multiple elements is generally approached using various approved methods from authoritative government sources such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), as well as consensus standards bodies such as ASTM International. The constituents of a sample can exist as unidentified compounds requiring sample preparation to be chosen appropriately, as in the case of beryllium in the form of beryllium oxide (BeO). An interlaboratory study was performed to collect analytical data from volunteer laboratories to examine the effectiveness of methods currently in use for preparation and analysis of samples containing calcined BeO powder. NIST SRM(®) 1877 high-fired BeO powder (1100 to 1200 °C calcining temperature; count median primary particle diameter 0.12 μm) was used to spike air filter media as a representative form of beryllium particulate matter present in workplace sampling that is known to be resistant to dissolution. The BeO powder standard reference material was gravimetrically prepared in a suspension and deposited onto 37 mm mixed cellulose ester air filters at five different levels between 0.5 μg and 25 μg of Be (as BeO). Sample sets consisting of five BeO-spiked filters (in duplicate) and two blank filters, for a total of twelve unique air filter samples per set, were submitted as blind samples to each of 27 participating laboratories. Participants were instructed to follow their current process for sample preparation and utilize their normal analytical methods for processing samples containing substances of this nature. Laboratories using more than one sample preparation and analysis method were provided with more than one sample set. Results from 34 data sets ultimately received from the 27 volunteer laboratories were subjected to applicable statistical analyses. The observed

  12. Sampling of nitrates in ambient air

    NASA Astrophysics Data System (ADS)

    Appel, B. R.; Tokiwa, Y.; Haik, M.

    Methods for the measurement of nitric acid, particulate nitrate and total inorganic nitrate (i.e. HNO 3 plus particulate nitrate) are compared using atmospheric samples from the Los Angeles Basin. Nitric acid was measured by (1) the nitrate collected on nylon or NaCl-impregnated cellulose filters after removal of particulate matter with Teflon prefilters, (2) long-path Fourier transform infrared spectroscopy (FTIR) performed by a collaborating investigator, and (3) the difference between total inorganic nitrate (TIN) and particulate nitrate (PN). TIN was measured by the sum of the nitrate collected with a Teflon prefilter and nylon or NaCl-impregnated after-filter. PN was measured by the nitrate able to penetrate a diffusion dénuder coated to remove acidic gases (e.g. HNO 3). Losses of nitrate from Teflon prefilters were determined by comparing the nitrate retained by these filters to the nitrate penetrating the acid gas denuder. TIN and the nitrate collected with glass fiber filters were compared to assess the origin of the artifact particulate nitrate on the latter. Nitric acid measurements using nylon or NaCl-impregnated after-filters were substantially higher than those by the difference technique. This correlated with losses of nitrate from the Teflon prefilters, which exceeded 50 % at high ambient temperature and low relative humidity. Nitric acid by the difference method exceeded that by FTIR by, on average, 20 %. Thus errors inferred in HNO 3 measurements by comparison to the difference measurements are considered minimum values. The high values for HNO 3 by the difference method are consistent with the partial loss of PN in the acid gas denuder. However, no loss of 0.1 μm to 3 μm diameter NH 4NO 3 particles was observed. Thus, if significant, such loss is restricted to coarse particulate nitrate. Heating the filter samplers was shown to increase sampling errors. Nitrate results obtained in short-term, low volume sampling with Gelman A glass fiber

  13. Air sampling with solid phase microextraction

    NASA Astrophysics Data System (ADS)

    Martos, Perry Anthony

    There is an increasing need for simple yet accurate air sampling methods. The acceptance of new air sampling methods requires compatibility with conventional chromatographic equipment, and the new methods have to be environmentally friendly, simple to use, yet with equal, or better, detection limits, accuracy and precision than standard methods. Solid phase microextraction (SPME) satisfies the conditions for new air sampling methods. Analyte detection limits, accuracy and precision of analysis with SPME are typically better than with any conventional air sampling methods. Yet, air sampling with SPME requires no pumps, solvents, is re-usable, extremely simple to use, is completely compatible with current chromatographic equipment, and requires a small capital investment. The first SPME fiber coating used in this study was poly(dimethylsiloxane) (PDMS), a hydrophobic liquid film, to sample a large range of airborne hydrocarbons such as benzene and octane. Quantification without an external calibration procedure is possible with this coating. Well understood are the physical and chemical properties of this coating, which are quite similar to those of the siloxane stationary phase used in capillary columns. The log of analyte distribution coefficients for PDMS are linearly related to chromatographic retention indices and to the inverse of temperature. Therefore, the actual chromatogram from the analysis of the PDMS air sampler will yield the calibration parameters which are used to quantify unknown airborne analyte concentrations (ppb v to ppm v range). The second fiber coating used in this study was PDMS/divinyl benzene (PDMS/DVB) onto which o-(2,3,4,5,6- pentafluorobenzyl) hydroxylamine (PFBHA) was adsorbed for the on-fiber derivatization of gaseous formaldehyde (ppb v range), with and without external calibration. The oxime formed from the reaction can be detected with conventional gas chromatographic detectors. Typical grab sampling times were as small as 5 seconds

  14. Impregnated filters for the collection of ethanethiol and butanethiol in air

    SciTech Connect

    Knarr, R.D.; Rappaport, S.M.

    1981-11-01

    The use of glass-fiber filters impregnated with mercuric acetate is described for the collection of methanethiol and butanethiol in air. The entrapped thiol is regenerated from the mercuric mercaptide, formed on the filter during sampling, by treatment with acid. Samples are analyzed by gas chromatography with a relative error of +/- 4% and a RSD of less than 2%. The method may be used for the measurement of long-term or short-term exposures in the range of 0.1 to 1 ppm.

  15. East Mountain Area 1995 air sampling results

    SciTech Connect

    Deola, R.A.

    1996-09-01

    Ambient air samples were taken at two locations in the East Mountain Area in conjunction with thermal testing at the Lurance Canyon Burn Site (LCBS). The samples were taken to provide measurements of particulate matter with a diameter less than or equal to 10 micrometers (PM{sub 10}) and volatile organic compounds (VOCs). This report summarizes the results of the sampling performed in 1995. The results from small-scale testing performed to determine the potentially produced air pollutants in the thermal tests are included in this report. Analytical results indicate few samples produced measurable concentrations of pollutants believed to be produced by thermal testing. Recommendations for future air sampling in the East Mountain Area are also noted.

  16. Assessment of the 3410 Building Filtered Exhaust Stack Sampling Probe Location

    SciTech Connect

    Glissmeyer, John A.; Flaherty, Julia E.

    2010-07-16

    Pacific Northwest National Laboratory performed several tests in the exhaust air discharge from the new 3410 Building Filtered Exhaust Stack to determine whether the air sampling probe for emissions monitoring for radionuclides is acceptable. The method followed involved adopting the results of a previously performed test series from a system with a similar configuration, followed by several tests on the actual system to verify the applicability of the previously performed tests. The qualification criteria for these types of stacks include metrics concerning 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity tracer particle concentration.

  17. Assessment of the 3420 Building Filtered Exhaust Stack Sampling Probe Location

    SciTech Connect

    Glissmeyer, John A.; Flaherty, Julia E.

    2010-07-16

    Pacific Northwest National Laboratory performed several tests in the exhaust air discharge from the new 3420 Building Filtered Exhaust Stack to determine whether the air sampling probe for emissions monitoring for radionuclides is acceptable. The method followed involved adopting the results of a previously performed test series from a system with a similar configuration, followed by several tests on the actual system to verify the applicability of the previously performed tests. The qualification criteria for these types of stacks include metrics concerning 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity tracer particle concentration.

  18. Determination of the concentration and isotopic composition of uranium in environmental air filters

    SciTech Connect

    Russ, G.P. III; Bazan, J.M.

    1994-08-26

    For many years, Lawrence Livermore National Laboratory has collected monthly air-particulate filter samples from a variety of environmental monitoring stations on and off site. Historically the concentration and isotopic composition of uranium collected on these filters was determined by isotope dilution using a {sup 233}U spike and thermal ionization mass spectrometry (TIMS). For samples containing as little as 10 nanograms of uranium, ICP-MS is now used to make these measurements to the required level of precision, about 5% in the measured 235/238 and 233/238. Unless particular care is taken to control bias in the mass filter, variable mass bias limits accuracy to a few percent. Measurements of the minor isotopes 236 (if present) and 234 are also possible and provide useful information for identifying the source of the uranium. The advantage of ICP-MS is in rapid analysis, {approximately}12 minutes of instrument time per sample.

  19. Generic Hardware Architectures for Sampling and Resampling in Particle Filters

    NASA Astrophysics Data System (ADS)

    Athalye, Akshay; Bolić, Miodrag; Hong, Sangjin; Djurić, Petar M.

    2005-12-01

    Particle filtering is a statistical signal processing methodology that has recently gained popularity in solving several problems in signal processing and communications. Particle filters (PFs) have been shown to outperform traditional filters in important practical scenarios. However their computational complexity and lack of dedicated hardware for real-time processing have adversely affected their use in real-time applications. In this paper, we present generic architectures for the implementation of the most commonly used PF, namely, the sampling importance resampling filter (SIRF). These provide a generic framework for the hardware realization of the SIRF applied to any model. The proposed architectures significantly reduce the memory requirement of the filter in hardware as compared to a straightforward implementation based on the traditional algorithm. We propose two architectures each based on a different resampling mechanism. Further, modifications of these architectures for acceleration of resampling process are presented. We evaluate these schemes based on resource usage and latency. The platform used for the evaluations is the Xilinx Virtex II pro FPGA. The architectures presented here have led to the development of the first hardware (FPGA) prototype for the particle filter applied to the bearings-only tracking problem.

  20. Seismic analysis of reactor exhaust air filter compartment

    SciTech Connect

    Gong, Chung; Funderburk, E.L.; Jerrell, J.W.

    1990-09-24

    The Filter Compartment (FC) in this analysis is a generic reactor airborne activity confinement filter compartment which possesses all the essential physical and mechanical properties of the Savannah River Site (SRS) confinement filters of Reactor Buildings K, L, and P. The filters belong to the Airborne Activity Confinement System (AACS). These filters absorb a significant amount of radioactive effluents from the exhausting air. The seismic excitation is input indirectly from the output of the seismic analysis of the 105 exhaust stack building in the form of floor response spectra. However, the 105 exhaust stack building was analyzed for seismic motions defined by free-field ground response spectra with a ZPA (Zero Period Acceleration) of 0.2G for all three orthogonal components of ground motion and a shape consistent with USNRC Regulatory Guide 1.60. Based upon equivalent dynamic analysis of the FC, DuPont engineers suggested modifications on the existing FC with heavy I-section beams [1]. The scope of this ``phase I`` analysis, as requested by Seismic Engineering [2], is to carry out a ``scoping analysis`` of Frequency Analysis and Response Spectrum Analysis of the FC with DuPont suggested conceptual modifications. Our suggestion was that the existing FC without conceptual modifications be analyzed first. However, the schedule urgency of the project and with guidance from the previous seismic analysis established the priority to perform the analysis for the FC with modifications in the ``phase I`` calculations.

  1. Seismic analysis of reactor exhaust air filter compartment

    SciTech Connect

    Gong, Chung; Funderburk, E.L.; Jerrell, J.W.

    1990-09-24

    The Filter Compartment (FC) in this analysis is a generic reactor airborne activity confinement filter compartment which possesses all the essential physical and mechanical properties of the Savannah River Site (SRS) confinement filters of Reactor Buildings K, L, and P. The filters belong to the Airborne Activity Confinement System (AACS). These filters absorb a significant amount of radioactive effluents from the exhausting air. The seismic excitation is input indirectly from the output of the seismic analysis of the 105 exhaust stack building in the form of floor response spectra. However, the 105 exhaust stack building was analyzed for seismic motions defined by free-field ground response spectra with a ZPA (Zero Period Acceleration) of 0.2G for all three orthogonal components of ground motion and a shape consistent with USNRC Regulatory Guide 1.60. Based upon equivalent dynamic analysis of the FC, DuPont engineers suggested modifications on the existing FC with heavy I-section beams (1). The scope of this phase I'' analysis, as requested by Seismic Engineering (2), is to carry out a scoping analysis'' of Frequency Analysis and Response Spectrum Analysis of the FC with DuPont suggested conceptual modifications. Our suggestion was that the existing FC without conceptual modifications be analyzed first. However, the schedule urgency of the project and with guidance from the previous seismic analysis established the priority to perform the analysis for the FC with modifications in the phase I'' calculations.

  2. Operational air sampling report, July--December 1991

    SciTech Connect

    Lyons, C.L.

    1992-11-01

    Air sampling is one of the more useful ways of assessing the effectiveness of operational radiation safety programs at the Nevada Test Site (NTS). Air sampling programs document NTS airborne radionuclide concentrations in various work locations and environments. These concentrations generally remain well below the Derived Air Concentration (DAC) values prescribed by the Department of Energy (DOE 5480.11, Attachment 1) or the Derived Concentration Guide (DCG) values prescribed by the Department of Energy DOE 5400.5, Chapter Ill. The Defense Nuclear Agency (DNA) tunnel complexes, Area 12 Test Support Compound and the Area 6 Decontamination Pad and Laundry air sampling programs are summarized in this report. Evaluations are based on Analytical Services Department (ASD) Counting Laboratory analyses and Health Protection Department (HPD)/Radiological Field Operations Section (RFOS) radiation protection technician's (RPT) or health physicists' calculations for air samples collected July 1 through December 31, 1991. Of the NTS operational air sampling programs in the tunnel complexes, the initial mining and event reentry and recovery operations represent the only real airborne radioactive inhalation potentials to personnel. Monthly filter and scintillation cell samples were taken and counted in RDA-200 Radon Detectors to document working levels of radon/thoron daughters and picocurie/liter (PCVL) concentrations of radon gas. Weekly Drierite samples for tritium analysis were taken in the active tunnel complexes to document any changes in normal background levels or reentry drifts as they are advanced toward ground zero (GZ) areas. Underground water sources are considered primary transporters of tritium from old event areas.

  3. Operational air sampling report, July--December 1991

    SciTech Connect

    Lyons, C.L.

    1992-11-01

    Air sampling is one of the more useful ways of assessing the effectiveness of operational radiation safety programs at the Nevada Test Site (NTS). Air sampling programs document NTS airborne radionuclide concentrations in various work locations and environments. These concentrations generally remain well below the Derived Air Concentration (DAC) values prescribed by the Department of Energy (DOE 5480.11, Attachment 1) or the Derived Concentration Guide (DCG) values prescribed by the Department of Energy DOE 5400.5, Chapter Ill. The Defense Nuclear Agency (DNA) tunnel complexes, Area 12 Test Support Compound and the Area 6 Decontamination Pad and Laundry air sampling programs are summarized in this report. Evaluations are based on Analytical Services Department (ASD) Counting Laboratory analyses and Health Protection Department (HPD)/Radiological Field Operations Section (RFOS) radiation protection technician`s (RPT) or health physicists` calculations for air samples collected July 1 through December 31, 1991. Of the NTS operational air sampling programs in the tunnel complexes, the initial mining and event reentry and recovery operations represent the only real airborne radioactive inhalation potentials to personnel. Monthly filter and scintillation cell samples were taken and counted in RDA-200 Radon Detectors to document working levels of radon/thoron daughters and picocurie/liter (PCVL) concentrations of radon gas. Weekly Drierite samples for tritium analysis were taken in the active tunnel complexes to document any changes in normal background levels or reentry drifts as they are advanced toward ground zero (GZ) areas. Underground water sources are considered primary transporters of tritium from old event areas.

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

    PubMed Central

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

    2014-01-01

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

  5. A comparison of portable XRF and ICP-OES analysis for lead on air filter samples from a lead ore concentrator mill and a lead-acid battery recycler.

    PubMed

    Harper, Martin; Pacolay, Bruce; Hintz, Patrick; Andrew, Michael E

    2006-03-01

    Personal and area samples for airborne lead were taken at a lead mine concentrator mill, and at a lead-acid battery recycler. Lead is mined as its sulfidic ore, galena, which is often associated with zinc and silver. The ore typically is concentrated, and partially separated, on site by crushing and differential froth flotation of the ore minerals before being sent to a primary smelter. Besides lead, zinc and iron are also present in the airborne dusts, together with insignificant levels of copper and silver, and, in one area, manganese. The disposal of used lead-acid batteries presents environmental issues, and is also a waste of recoverable materials. Recycling operations allow for the recovery of lead, which can then be sold back to battery manufacturers to form a closed loop. At the recycling facility lead is the chief airborne metal, together with minor antimony and tin, but several other metals are generally present in much smaller quantities, including copper, chromium, manganese and cadmium. Samplers used in these studies included the closed-face 37 mm filter cassette (the current US standard method for lead sampling), the 37 mm GSP or "cone" sampler, the 25 mm Institute of Occupational Medicine (IOM) inhalable sampler, the 25 mm Button sampler, and the open-face 25 mm cassette. Mixed cellulose-ester filters were used in all samplers. The filters were analyzed after sampling for their content of the various metals, particularly lead, that could be analyzed by the specific portable X-ray fluorescence (XRF) analyzer under study, and then were extracted with acid and analyzed by inductively coupled plasma optical emission spectroscopy (ICP-OES). The 25 mm filters were analyzed using a single XRF reading, while three readings on different parts of the filter were taken from the 37 mm filters. For lead at the mine concentrate mill, all five samplers gave good correlations (r2 > 0.96) between the two analytical methods over the entire range of found lead mass

  6. Combination syringe provides air-free blood samples

    NASA Technical Reports Server (NTRS)

    Pool, S. L.

    1970-01-01

    Standard syringe and spinal needle are combined in unique manner to secure air-free blood samples. Combination syringe obtains air free samples because air bubbles become insignificant when samples greater than 1 cc are drawn.

  7. Transparent air filter for high-efficiency PM2.5 capture

    NASA Astrophysics Data System (ADS)

    Liu, Chong; Hsu, Po-Chun; Lee, Hyun-Wook; Ye, Meng; Zheng, Guangyuan; Liu, Nian; Li, Weiyang; Cui, Yi

    2015-02-01

    Particulate matter (PM) pollution has raised serious concerns for public health. Although outdoor individual protection could be achieved by facial masks, indoor air usually relies on expensive and energy-intensive air-filtering devices. Here, we introduce a transparent air filter for indoor air protection through windows that uses natural passive ventilation to effectively protect the indoor air quality. By controlling the surface chemistry to enable strong PM adhesion and also the microstructure of the air filters to increase the capture possibilities, we achieve transparent, high air flow and highly effective air filters of ~90% transparency with >95.00% removal of PM2.5 under extreme hazardous air-quality conditions (PM2.5 mass concentration >250 μg m-3). A field test in Beijing shows that the polyacrylonitrile transparent air filter has the best PM2.5 removal efficiency of 98.69% at high transmittance of ~77% during haze occurrence.

  8. Evaluation of the 2014 EC measurement comparison on (137)Cs in air filters.

    PubMed

    Máté, B; Sobiech-Matura, K; Altzitzoglou, T

    2016-03-01

    In 2014, the Joint Research Centre organised an interlaboratory comparison of (137)Cs measurement in air filters. This paper describes the context of the European measurement comparisons, as well as the technical implementation. Furthermore, sample treatment and measurements performed by participating laboratories are discussed and finally the evaluation of comparison results is presented. The intercomparison results are such that 71 out of the 76 laboratories (i.e. 93.4%) reported values within ±33% range of the reference value. PMID:26701658

  9. Clever particle filters, sequential importance sampling and the optimal proposal

    NASA Astrophysics Data System (ADS)

    Snyder, Chris

    2014-05-01

    Particle filters rely on sequential importance sampling and it is well known that their performance can depend strongly on the choice of proposal distribution from which new ensemble members (particles) are drawn. The use of clever proposals has seen substantial recent interest in the geophysical literature, with schemes such as the implicit particle filter and the equivalent-weights particle filter. Both these schemes employ proposal distributions at time tk+1 that depend on the state at tk and the observations at time tk+1. I show that, beginning with particles drawn randomly from the conditional distribution of the state at tk given observations through tk, the optimal proposal (the distribution of the state at tk+1 given the state at tk and the observations at tk+1) minimizes the variance of the importance weights for particles at tk overall all possible proposal distributions. This means that bounds on the performance of the optimal proposal, such as those given by Snyder (2011), also bound the performance of the implicit and equivalent-weights particle filters. In particular, in spite of the fact that they may be dramatically more effective than other particle filters in specific instances, those schemes will suffer degeneracy (maximum importance weight approaching unity) unless the ensemble size is exponentially large in a quantity that, in the simplest case that all degrees of freedom in the system are i.i.d., is proportional to the system dimension. I will also discuss the behavior to be expected in more general cases, such as global numerical weather prediction, and how that behavior depends qualitatively on the observing network. Snyder, C., 2012: Particle filters, the "optimal" proposal and high-dimensional systems. Proceedings, ECMWF Seminar on Data Assimilation for Atmosphere and Ocean., 6-9 September 2011.

  10. Sampling and Analyzing Air Pollution: An Apparatus Suitable for Use in Schools.

    ERIC Educational Resources Information Center

    Rockwell, Dean M.; Hansen, Tony

    1994-01-01

    Describes two variations of an air sampler and analyzer that are inexpensive to construct, easy to operate, and designed to be used in an educational program. Variations use vacuum cleaners and aquarium pumps, and white facial tissues serve as filters. Samples of air pollution obtained by this method may be used from early grade school to advanced…

  11. Evaluation of sampling methods for Bacillus spore-contaminated HVAC filters

    PubMed Central

    Calfee, M. Worth; Rose, Laura J.; Tufts, Jenia; Morse, Stephen; Clayton, Matt; Touati, Abderrahmane; Griffin-Gatchalian, Nicole; Slone, Christina; McSweeney, Neal

    2016-01-01

    The objective of this study was to compare an extraction-based sampling method to two vacuum-based sampling methods (vacuum sock and 37 mm cassette filter) with regards to their ability to recover Bacillus atrophaeus spores (surrogate for Bacillus anthracis) from pleated heating, ventilation, and air conditioning (HVAC) filters that are typically found in commercial and residential buildings. Electrostatic and mechanical HVAC filters were tested, both without and after loading with dust to 50% of their total holding capacity. The results were analyzed by one-way ANOVA across material types, presence or absence of dust, and sampling device. The extraction method gave higher relative recoveries than the two vacuum methods evaluated (p ≤ 0.001). On average, recoveries obtained by the vacuum methods were about 30% of those achieved by the extraction method. Relative recoveries between the two vacuum methods were not significantly different (p > 0.05). Although extraction methods yielded higher recoveries than vacuum methods, either HVAC filter sampling approach may provide a rapid and inexpensive mechanism for understanding the extent of contamination following a wide-area biological release incident. PMID:24184312

  12. Evaluation of sampling methods for Bacillus spore-contaminated HVAC filters.

    PubMed

    Calfee, M Worth; Rose, Laura J; Tufts, Jenia; Morse, Stephen; Clayton, Matt; Touati, Abderrahmane; Griffin-Gatchalian, Nicole; Slone, Christina; McSweeney, Neal

    2014-01-01

    The objective of this study was to compare an extraction-based sampling method to two vacuum-based sampling methods (vacuum sock and 37mm cassette filter) with regards to their ability to recover Bacillus atrophaeus spores (surrogate for Bacillus anthracis) from pleated heating, ventilation, and air conditioning (HVAC) filters that are typically found in commercial and residential buildings. Electrostatic and mechanical HVAC filters were tested, both without and after loading with dust to 50% of their total holding capacity. The results were analyzed by one-way ANOVA across material types, presence or absence of dust, and sampling device. The extraction method gave higher relative recoveries than the two vacuum methods evaluated (p≤0.001). On average, recoveries obtained by the vacuum methods were about 30% of those achieved by the extraction method. Relative recoveries between the two vacuum methods were not significantly different (p>0.05). Although extraction methods yielded higher recoveries than vacuum methods, either HVAC filter sampling approach may provide a rapid and inexpensive mechanism for understanding the extent of contamination following a wide-area biological release incident. PMID:24184312

  13. Bioaerosol DNA Extraction Technique from Air Filters Collected from Marine and Freshwater Locations

    NASA Astrophysics Data System (ADS)

    Beckwith, M.; Crandall, S. G.; Barnes, A.; Paytan, A.

    2015-12-01

    Bioaerosols are composed of microorganisms suspended in air. Among these organisms include bacteria, fungi, virus, and protists. Microbes introduced into the atmosphere can drift, primarily by wind, into natural environments different from their point of origin. Although bioaerosols can impact atmospheric dynamics as well as the ecology and biogeochemistry of terrestrial systems, very little is known about the composition of bioaerosols collected from marine and freshwater environments. The first step to determine composition of airborne microbes is to successfully extract environmental DNA from air filters. We asked 1) can DNA be extracted from quartz (SiO2) air filters? and 2) how can we optimize the DNA yield for downstream metagenomic sequencing? Aerosol filters were collected and archived on a weekly basis from aquatic sites (USA, Bermuda, Israel) over the course of 10 years. We successfully extracted DNA from a subsample of ~ 20 filters. We modified a DNA extraction protocol (Qiagen) by adding a beadbeating step to mechanically shear cell walls in order to optimize our DNA product. We quantified our DNA yield using a spectrophotometer (Nanodrop 1000). Results indicate that DNA can indeed be extracted from quartz filters. The additional beadbeating step helped increase our yield - up to twice as much DNA product was obtained compared to when this step was omitted. Moreover, bioaerosol DNA content does vary across time. For instance, the DNA extracted from filters from Lake Tahoe, USA collected near the end of June decreased from 9.9 ng/μL in 2007 to 3.8 ng/μL in 2008. Further next-generation sequencing analysis of our extracted DNA will be performed to determine the composition of these microbes. We will also model the meteorological and chemical factors that are good predictors for microbial composition for our samples over time and space.

  14. Sulfate and nitrate collected by filter sampling near the tropopause

    NASA Technical Reports Server (NTRS)

    Humenik, F. M.; Lezberg, E. A.; Otterson, D. A.

    1980-01-01

    Filter samples collected near the tropopause with an F-106 aircraft and two Boeing 747 aircraft were analyzed for sulfate and nitrate ion content. Within the range of routine commercial flight altitudes (at or below 12.5 km), stratospheric mass mixing ratios for the winter-spring group averaged 0.26 ppbm for sulfate and 0.35 ppbm for nitrate. For the summer-fall group, stratosphere mixing ratios averaged 0.13 ppbm and 0.25 ppbm for sulfate and nitrate, respectively. Winter-spring group tropospheric mass mixing ratios averaged 0.08 ppbm for sulfate and 0.10 ppbm for nitrate, while summer-fall group tropospheric mixing ratios averaged 0.05 ppbm for sulfate and 0.08 ppbm for nitrate. Correlations of the filter data with available ozone data suggest that the sulfate and nitrate are transported from the stratosphere to the troposphere.

  15. Antimicrobial Air Filters Using Natural Euscaphis japonica Nanoparticles.

    PubMed

    Hwang, Gi Byoung; Heo, Ki Joon; Yun, Ji Ho; Lee, Jung Eun; Lee, Hee Ju; Nho, Chu Won; Bae, Gwi-Nam; Jung, Jae Hee

    2015-01-01

    Controlling bioaerosols has become more important with increasing participation in indoor activities. Treatments using natural-product nanomaterials are a promising technique because of their relatively low toxicity compared to inorganic nanomaterials such as silver nanoparticles or carbon nanotubes. In this study, antimicrobial filters were fabricated from natural Euscaphis japonica nanoparticles, which were produced by nebulizing E. japonica extract. The coated filters were assessed in terms of pressure drop, antimicrobial activity, filtration efficiency, major chemical components, and cytotoxicity. Pressure drop and antimicrobial activity increased as a function of nanoparticle deposition time (590, 855, and 1150 µg/cm2(filter) at 3-, 6-, and 9-min depositions, respectively). In filter tests, the antimicrobial efficacy was greater against Staphylococcus epidermidis than Micrococcus luteus; ~61, ~73, and ~82% of M. luteus cells were inactivated on filters that had been coated for 3, 6, and 9 min, respectively, while the corresponding values were ~78, ~88, and ~94% with S. epidermidis. Although statistically significant differences in filtration performance were not observed between samples as a function of deposition time, the average filtration efficacy was slightly higher for S. epidermidis aerosols (~97%) than for M. luteus aerosols (~95%). High-performance liquid chromatography (HPLC) and electrospray ionization-tandem mass spectrometry (ESI/MS) analyses confirmed that the major chemical compounds in the E. japonica extract were 1(ß)-O-galloyl pedunculagin, quercetin-3-O-glucuronide, and kaempferol-3-O-glucoside. In vitro cytotoxicity and disk diffusion tests showed that E. japonica nanoparticles were less toxic and exhibited stronger antimicrobial activity toward some bacterial strains than a reference soluble nickel compound, which is classified as a human carcinogen. This study provides valuable information for the development of a bioaerosol control

  16. Antimicrobial Air Filters Using Natural Euscaphis japonica Nanoparticles

    PubMed Central

    Yun, Ji Ho; Lee, Jung Eun; Lee, Hee Ju; Nho, Chu Won; Bae, Gwi- Nam; Jung, Jae Hee

    2015-01-01

    Controlling bioaerosols has become more important with increasing participation in indoor activities. Treatments using natural-product nanomaterials are a promising technique because of their relatively low toxicity compared to inorganic nanomaterials such as silver nanoparticles or carbon nanotubes. In this study, antimicrobial filters were fabricated from natural Euscaphis japonica nanoparticles, which were produced by nebulizing E. japonica extract. The coated filters were assessed in terms of pressure drop, antimicrobial activity, filtration efficiency, major chemical components, and cytotoxicity. Pressure drop and antimicrobial activity increased as a function of nanoparticle deposition time (590, 855, and 1150 µg/cm2filter at 3-, 6-, and 9-min depositions, respectively). In filter tests, the antimicrobial efficacy was greater against Staphylococcus epidermidis than Micrococcus luteus; ~61, ~73, and ~82% of M. luteus cells were inactivated on filters that had been coated for 3, 6, and 9 min, respectively, while the corresponding values were ~78, ~88, and ~94% with S. epidermidis. Although statistically significant differences in filtration performance were not observed between samples as a function of deposition time, the average filtration efficacy was slightly higher for S. epidermidis aerosols (~97%) than for M. luteus aerosols (~95%). High-performance liquid chromatography (HPLC) and electrospray ionization-tandem mass spectrometry (ESI/MS) analyses confirmed that the major chemical compounds in the E. japonica extract were 1(ß)-O-galloyl pedunculagin, quercetin-3-O-glucuronide, and kaempferol-3-O-glucoside. In vitro cytotoxicity and disk diffusion tests showed that E. japonica nanoparticles were less toxic and exhibited stronger antimicrobial activity toward some bacterial strains than a reference soluble nickel compound, which is classified as a human carcinogen. This study provides valuable information for the development of a bioaerosol control

  17. Sampling Versus Filtering in Large-Eddy Simulations

    NASA Technical Reports Server (NTRS)

    Debliquy, O.; Knaepen, B.; Carati, D.; Wray, A. A.

    2004-01-01

    A LES formalism in which the filter operator is replaced by a sampling operator is proposed. The unknown quantities that appear in the LES equations originate only from inadequate resolution (Discretization errors). The resulting viewpoint seems to make a link between finite difference approaches and finite element methods. Sampling operators are shown to commute with nonlinearities and to be purely projective. Moreover, their use allows an unambiguous definition of the LES numerical grid. The price to pay is that sampling never commutes with spatial derivatives and the commutation errors must be modeled. It is shown that models for the discretization errors may be treated using the dynamic procedure. Preliminary results, using the Smagorinsky model, are very encouraging.

  18. Ambient Air Sampling During Quantum-dot Spray Deposition

    SciTech Connect

    Jankovic, John Timothy; Hollenbeck, Scott M

    2010-01-01

    Ambient air sampling for nano-size particle emissions was performed during spot spray coating operations with a Sono-Tek Exactacoat Benchtop system (ECB). The ECB consisted of the application equipment contained within an exhaust enclosure. The enclosure contained numerous small access openings, including an exhaust hook-up. Door access comprised most of the width and height of the front. The door itself was of the swing-out type. Two types of nanomaterials, Cadmium selenide (Cd-Se) quantum-dots (QDs) and Gold (Au) QDs, nominally 3.3 and 5 nm in diameter respectively, were applied during the evaluation. Median spray drop size was in the 20 to 60 micrometer size range.1 Surface coating tests were of short duration, on the order of one-half second per spray and ten spray applications between door openings. The enclosure was ventilated by connection to a high efficiency particulate aerosol (HEPA) filtered house exhaust system. The exhaust rate was nominally 80 ft3 per minute producing about 5 air changes per minute. Real time air monitoring with a scanning mobility particle size analyzer (SMPS ) with a size detection limit of 7 nm indicated a significant increase in the ambient air concentration upon early door opening. A handheld condensation particle counter (CPC) with a lower size limit of 10 nm did not record changes in the ambient background. This increase in the ambient was not observed when door opening was delayed for 2 minutes (~10 air changes). The ventilated enclosure controlled emissions except for cases of rapid door opening before the overspray could be removed by the exhaust. A time delay sufficient to provide 10 enclosure air changes (a concentration reduction of more than 99.99 %) before door opening prevented the release of aerosol particles in any size.2 Scanning-transmission electron microscopy (STEM) and atomic force microscopy (AFM) demonstrated the presence of agglomerates in the surfaces of the spray applied deposition. A filtered air sample of

  19. Air Sampling Instruments for Evaluation of Atmospheric Contaminants. Fourth Edition.

    ERIC Educational Resources Information Center

    American Conference of Governmental Industrial Hygienists, Cincinnati, OH.

    This text, a revision and extension of the first three editions, consists of papers discussing the basic considerations in sampling air for specific purposes, sampler calibration, systems components, sample collectors, and descriptions of air-sampling instruments. (BT)

  20. Assessment of the capacity of vehicle cabin air inlet filters to reduce diesel exhaust-induced symptoms in human volunteers

    PubMed Central

    2014-01-01

    Background Exposure to particulate matter (PM) air pollution especially derived from traffic is associated with increases in cardiorespiratory morbidity and mortality. In this study, we evaluated the ability of novel vehicle cabin air inlet filters to reduce diesel exhaust (DE)-induced symptoms and markers of inflammation in human subjects. Methods Thirty healthy subjects participated in a randomized double-blind controlled crossover study where they were exposed to filtered air, unfiltered DE and DE filtered through two selected particle filters, one with and one without active charcoal. Exposures lasted for one hour. Symptoms were assessed before and during exposures and lung function was measured before and after each exposure, with inflammation assessed in peripheral blood five hours after exposures. In parallel, PM were collected from unfiltered and filtered DE and assessed for their capacity to drive damaging oxidation reactions in a cell-free model, or promote inflammation in A549 cells. Results The standard particle filter employed in this study reduced PM10 mass concentrations within the exposure chamber by 46%, further reduced to 74% by the inclusion of an active charcoal component. In addition use of the active charcoal filter was associated by a 75% and 50% reduction in NO2 and hydrocarbon concentrations, respectively. As expected, subjects reported more subjective symptoms after exposure to unfiltered DE compared to filtered air, which was significantly reduced by the filter with an active charcoal component. There were no significant changes in lung function after exposures. Similarly diesel exhaust did not elicit significant increases in any of the inflammatory markers examined in the peripheral blood samples 5 hour post-exposure. Whilst the filters reduced chamber particle concentrations, the oxidative activity of the particles themselves, did not change following filtration with either filter. In contrast, diesel exhaust PM passed through the

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

    EPA Science Inventory

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

  2. NEUTRON ACTIVATION ANALYSIS FOR SIMULTANEOUS DETERMINATION OF TRACE ELEMENTS IN AMBIENT AIR COLLECTED ON GLASS-FIBER FILTERS

    EPA Science Inventory

    Arsenic with 25 other elements are simultaneously determined in ambient air samples collected on glass-fiber filter composites at 250 United States sites. The instrumental neutron activation analysis (NAA) technique combined with the power of a dedicated mini-computer resulted in...

  3. Diagnosing AIRS Sampling with CloudSat Cloud Classes

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  4. Incorrect interpretation of moving-filter continuous particulate air monitor responses.

    PubMed

    Evans, William C

    2013-04-01

    The graphs supplied by the vendors of moving-filter continuous particulate air monitors (CPAMs) in their sales literature show linear curves on a log-log scale, with net count rate on one axis and concentration on the other. The implication is that the monitor user is to read the concentration from the graph, given an observed net count rate, at any time. For the nominal filter speeds commonly used for these monitors, using the graph in this way is incorrect. The graphs do not state the limitations of the calculation: (1) the nuclide measured must be long-lived; (2) the concentration of that nuclide in the sampled air must remain constant; and (3) the reading of the net count rate must be obtained after a specific time, called the "transit time." This time is typically on the order of several hours. Reading the net count rate at any time earlier than this will result in an incorrect concentration estimate. Given that a major purpose of a CPAM is to alert plant personnel to a change in airborne radioactivity concentrations, by definition when this happens the concentration is not constant. Thus, using the supplied curves will result in an incorrect estimate of that concentration. The solution is to use instead a fixed-filter CPAM and a previously-published quantitative method. With this approach, there is no need to attempt to estimate a concentration, much less to assume that it is constant over long periods of time or that it can only change in a stair-step manner. With this alternative to a moving-filter CPAM, a signal proportional to the time-integrated worker intake can be generated continuously for any time-varying air concentration, including the sums-of-exponentials shapes expected during transient events in compartmental systems. PMID:23439149

  5. 40 CFR 53.57 - Test for filter temperature control during sampling and post-sampling periods.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... (40 CFR part 50, appendix L, figure L-30) or equivalent adaptor to facilitate measurement of sampler... recommended. (6) Sample filter or filters, as specified in section 6 of 40 CFR part 50, appendix L. (d... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test for filter temperature...

  6. 40 CFR 53.57 - Test for filter temperature control during sampling and post-sampling periods.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... (40 CFR part 50, appendix L, figure L-30) or equivalent adaptor to facilitate measurement of sampler... recommended. (6) Sample filter or filters, as specified in section 6 of 40 CFR part 50, appendix L. (d... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test for filter temperature...

  7. Antimicrobial nanoparticle-coated electrostatic air filter with high filtration efficiency and low pressure drop.

    PubMed

    Sim, Kyoung Mi; Park, Hyun-Seol; Bae, Gwi-Nam; Jung, Jae Hee

    2015-11-15

    In this study, we demonstrated an antimicrobial nanoparticle-coated electrostatic (ES) air filter. Antimicrobial natural-product Sophora flavescens nanoparticles were produced using an aerosol process, and were continuously deposited onto the surface of air filter media. For the electrostatic activation of the filter medium, a corona discharge electrification system was used before and after antimicrobial treatment of the filter. In the antimicrobial treatment process, the deposition efficiency of S. flavescens nanoparticles on the ES filter was ~12% higher than that on the pristine (Non-ES) filter. In the evaluation of filtration performance using test particles (a nanosized KCl aerosol and submicron-sized Staphylococcus epidermidis bioaerosol), the ES filter showed better filtration efficiency than the Non-ES filter. However, antimicrobial treatment with S. flavescens nanoparticles affected the filtration efficiency of the filter differently depending on the size of the test particles. While the filtration efficiency of the KCl nanoparticles was reduced on the ES filter after the antimicrobial treatment, the filtration efficiency was improved after the recharging process. In summary, we prepared an antimicrobial ES air filter with >99% antimicrobial activity, ~92.5% filtration efficiency (for a 300-nm KCl aerosol), and a ~0.8 mmAq pressure drop (at 13 cm/s). This study provides valuable information for the development of a hybrid air purification system that can serve various functions and be used in an indoor environment. PMID:26172593

  8. Preparation of Fiber Based Binder Materials to Enhance the Gas Adsorption Efficiency of Carbon Air Filter.

    PubMed

    Lim, Tae Hwan; Choi, Jeong Rak; Lim, Dae Young; Lee, So Hee; Yeo, Sang Young

    2015-10-01

    Fiber binder adapted carbon air filter is prepared to increase gas adsorption efficiency and environmental stability. The filter prevents harmful gases, as well as particle dusts in the air from entering the body when a human inhales. The basic structure of carbon air filter is composed of spunbond/meltblown/activated carbon/bottom substrate. Activated carbons and meltblown layer are adapted to increase gas adsorption and dust filtration efficiency, respectively. Liquid type adhesive is used in the conventional carbon air filter as a binder material between activated carbons and other layers. However, it is thought that the liquid binder is not an ideal material with respect to its bonding strength and liquid flow behavior that reduce gas adsorption efficiency. To overcome these disadvantages, fiber type binder is introduced in our study. It is confirmed that fiber type binder adapted air filter media show higher strip strength, and their gas adsorption efficiencies are measured over 42% during 60 sec. These values are higher than those of conventional filter. Although the differential pressure of fiber binder adapted air filter is relatively high compared to the conventional one, short fibers have a good potential as a binder materials of activated carbon based air filter. PMID:26726459

  9. Assessment of the Revised 3410 Building Filtered Exhaust Stack Sampling Probe Location

    SciTech Connect

    Yu, Xiao-Ying; Recknagle, Kurtis P.; Glissmeyer, John A.

    2013-12-01

    In order to support the air emissions permit for the 3410 Building, Pacific Northwest National Laboratory performed a series of tests in the exhaust air discharge from the reconfigured 3410 Building Filtered Exhaust Stack. The objective was to determine whether the location of the air sampling probe for emissions monitoring meets the applicable regulatory criteria governing such effluent monitoring systems. In particular, the capability of the air sampling probe location to meet the acceptance criteria of ANSI/HPS N13.1-2011 , Sampling and Monitoring Releases of Airborne Radioactive Substances from the Stack and Ducts of Nuclear Facilities was determined. The qualification criteria for these types of stacks address 1) uniformity of air velocity, 2) sufficiently small flow angle with respect to the axis of the duct, 3) uniformity of tracer gas concentration, and 4) uniformity of tracer particle concentration. Testing was performed to conform to the quality requirements of NQA-1-2000. Fan configurations tested included all fan combinations of any two fans at a time. Most of the tests were conducted at the normal flow rate, while a small subset of tests was performed at a slightly higher flow rate achieved with the laboratory hood sashes fully open. The qualification criteria for an air monitoring probe location are taken from ANSI/HPS N13.1-2011 and are paraphrased as follows with key results summarized: 1. Angular Flow—The average air velocity angle must not deviate from the axis of the stack or duct by more than 20°. Our test results show that the mean angular flow angles at the center two-thirds of the ducts are smaller than 4.5% for all testing conditions. 2. Uniform Air Velocity—The acceptance criterion is that the COV of the air velocity must be ≤ 20% across the center two thirds of the area of the stack. Our results show that the COVs of the air velocity across the center two-thirds of the stack are smaller than 2.9% for all testing conditions. 3

  10. SAMPLING FOR ORGANIC CHEMICALS IN AIR

    EPA Science Inventory

    Organic chemicals by far account for the majority of pollutants found in air. ore than 90% of the 75,000 chemicals listed in EPA's Toxic Substances Control Act Chemical Substance Inventory and 88% of the 189 Hazardous Air Pollutants (HAPS) named in the Clean Air Act Amendments of...

  11. Impact of Air Filter Material on Metal Oxide Semiconductor (MOS) Device Characteristics in HF Vapor Environment

    NASA Astrophysics Data System (ADS)

    Hsiao, Chih-Wen; Lou, Jen-Chung; Yeh, Ching-Fa; Hsieh, Chih-Ming; Lin, Shiuan-Jeng; Kusumi, Toshio

    2004-05-01

    Airborne molecular contamination (AMC) is becoming increasingly important as devices are scaled down to the nanometer generation. Optimum ultra low penetration air (ULPA) filter technology can eliminate AMC. In a cleanroom, however, the acid vapor generated from the cleaning process may degrade the ULPA filter, releasing AMC to the air and the surface of wafers, degrading the electrical characteristics of devices. This work proposes the new PTFE ULPA filter, which is resistant to acid vapor corrosion, to solve this problem. Experimental results demonstrate that the PTFE ULPA filter can effectively eliminate the AMC and provide a very clean cleanroom environment.

  12. Bias in air sampling techniques used to measure inhalation exposure.

    PubMed

    Cohen, B S; Harley, N H; Lippmann, M

    1984-03-01

    Factors have been evaluated which contribute to the lack of agreement between inhalation exposure estimates obtained by time-weighted averaging of samples taken with mini hi-volume samplers, and those measured by time integrating, low-volume, lapel mounted, personal monitors. Measurements made with real-time aerosol monitors on workers at a Be-Cu production furnace show that part of the discrepancy results from variability of the aerosol concentration within the breathing zone. Field studies of sampler inlet bias, the influences of the electrostatic fields around polystyrene filter holders, and resuspension of dust from work clothing, were done in three areas of a Be plant. No significant differences were found in Be air concentrations measured simultaneously by open and closed face cassettes, and "mini hi-volume" samplers mounted on a test stand. No significant influence on Be collection was detected between either positively or negatively charged monitors and charge neutralized control monitors. The effect of contaminated work clothing on dust collection by lapel mounted monitors is most important. Beryllium release from the fabrics affected air concentrations measured by fabric mounted monitors more than it affected concentrations measured by monitors positioned above the fabrics. The latter were placed 16 cm from the vertically mounted fabrics, to simulate the position of the nose or mouth. We conclude that dust resuspended from work clothing is the major source of the observed discrepancy between exposures estimated from lapel mounted samplers and time-weighted averages. PMID:6720582

  13. Bias in air sampling techniques used to measure inhalation exposure

    SciTech Connect

    Cohen, B.S.; Harley, N.H.; Lippmann, M.

    1984-03-01

    Factors have been evaluated which contribute to the lack of agreement between inhalation exposure estimates obtained by time-weighted averaging of samples taken with mini hi-volume samplers, and those measured by time integrating, low-volume, lapel mounted, personal monitors. Measurements made with real-time aerosol monitors on workers at a Be-Cu production furnace show that part of the discrepancy results from variability of the aerosol concentration within the breathing zone. Field studies of sampler inlet bias, the influences of the electrostatic fields around polystyrene filter holders, and resuspension of dust from work clothing, were done in three areas of a Be plant. No significant differences were found in Be air concentrations measured simultaneously by open and closed face cassettes, and mini hi-volume samplers mounted on a test stand. No significant influence on Be collection was detected between either positively or negatively charged monitors and charge neutralized control monitors. The effect of contaminated work clothing on dust collection by lapel mounted monitors is most important. Beryllium release from the fabrics affected air concentrations measured by fabric mounted monitors more than it affected concentrations measured by monitors positioned above the fabrics. The latter were placed 16 cm from the vertically mounted fabrics, to simulate the position of the nose or mouth. The authors conclude that dust resuspended from work clothing is the major source of the observed discrepancy between exposures estimated from lapel mounted samplers and time-weighted averages.

  14. Functional performance testing of the universal super absorbing air filters FSU 70 „Air by Corneliu”

    NASA Astrophysics Data System (ADS)

    Raţiu, S.; Birtok-Băneasă, C.; Alexa, V.; Kiss, I.

    2015-06-01

    This paper presents the experimental methodology to carry out functional performance tests for an air filter with a particular design of its housing, generically named Universal super absorbing FSU 70 „Air by Corneliu”. The tests were carried out in the Internal Combustion Engines Laboratory, within the specialization "Road automotives" belonging to the Faculty of Engineering Hunedoara, component of “Politehnica” University of Timisoara. We present some comparative values of various operating parameters of the engine fitted, in the first measuring session, with the original filter, and then with the studied filter.

  15. Sampling and analysis of trace-organic constituents in ambient and workplace air at coal-conversion facilities

    SciTech Connect

    Flotard, R D

    1980-07-01

    A review of the recent literature reveals that current sampling procedures involve the use of glass fiber filters for particulate-sorbed organics and sorbent resins such as Tenax GC and XAD-2 for vapor-phase organics. Ultra trace-organic analysis of air pollutants or particulates may require the collection of a large (1000 to 3000 m/sup 3/) sample by a high volume air sampler. Personal air sampling requires a smaller (approx. = 0.5 m/sup 3/) and a portable collection apparatus. Trapped organic chemicals are recovered by solvent extraction or thermal desorption of the collector. Recovered organics are separated by using liquid chromatography or gas chromatography and are identified by ultraviolet or fluorescence spectroscopy, gas chromatography, or mass spectrometry. For quantification, standards are added to the air stream during sampling or to the filter or resin following sampling. Analysis of the requirement for air sampling in and around coal conversion plants, coupled with the findings of the literature review, indicates that a combined particulate-filter and solvent-extractable-resin sampling unit should be used to collect both particulate-sorbed organics and vapor-phase organics from workplace or ambient plant air. Such a sampler was developed for stationary, moderate-to-high-volume air sampling. Descriptions of the sampler are provided together with sampling efficiency information and recommendations for a sampling procedure.

  16. Biomass control in waste air biotrickling filters by protozoan predation

    SciTech Connect

    Cox, H.H.J.; Deshusses, M.A.

    1999-01-20

    Two protozoan species as well as an uncharacterized protozoan consortium were added to a toluene-degrading biotrickling filter to investigate protozoan predation as a means of biomass control. Wet biomass formation in 23.6-L reactors over a 77-day period was reduced from 13.875 kg in a control biotrickling filter to 11.795 kg in a biotrickling filter enriched with protozoa. The average toluene vapor elimination capacity at 1 g/m{sup 3} toluene and 64 m{sup 3}/(m{sup 3} {center_dot} h) was 31.1 g(m{sup 3} {center_dot} h) in the control and 32.2 g(m{sup 3} {center_dot} h) in the biotrickling filter enriched with protozoa. At higher toluene inlet concentrations, toluene degradation rates increased and were slightly higher in the biotrickling filter enriched with protozoa. The lower rate of biomass accumulation after the addition of protozoa was due to an increase of carbon mineralization. Apparent biomass yield coefficients in the control and enriched trickling filter were 0.72 and 0.59 g dry biomass/g toluene, respectively. The results show that protozoan predation may be a useful tool to control biomass in biotrickling filters, however, further stimulation of predation of the biomass immobilized in the reactor is required to ensure long-term stability of biotrickling filters.

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

    SciTech Connect

    Metzger, R.L.; Jessop, B.H.; McDowell, B.L.

    1996-02-01

    A solubility testing method for several common actinides has been developed with sufficient sensitivity to allow profiles to be determined from routine breathing zone and area air samples in the workplace. Air samples are covered with a clean filter to form a filter-sample-filter sandwich which is immersed in an extracellular lung serum simulant solution. The sample is moved to a fresh beaker of the lung fluid simulant each day for one week, and then weekly until the end of the 28 day test period. The soak solutions are wet ashed with nitric acid and hydrogen peroxide to destroy the organic components of the lung simulant solution prior to extraction of the nuclides of interest directly into an extractive scintillator for subsequent counting on a Photon-Electron Rejecting Alpha Liquid Scintillation (PERALS{reg_sign}) spectrometer. Solvent extraction methods utilizing the extractive scintillators have been developed for the isotopes of uranium, plutonium, and curium. The procedures normally produce an isotopic recovery greater than 95% and have been used to develop solubility profiles from air samples with 40 pCi or less of U{sub 3}O{sub 8}. Profiles developed for U{sub 3}O{sub 8} samples show good agreement with in vitro and in vivo tests performed by other investigators on samples from the same uranium mills.

  18. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - INSPEC FIBRES 5512BRF FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  19. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - BHA GROUP, INC. QG061 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  20. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - MENARDI-CRISWELL 50-504 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  1. ANALYSIS OF VAPORS FROM METHYLENE CHLORIDE EXTRACTS OF NUCLEAR GRADE HEPA FILTER FIBERGLASS SAMPLES

    SciTech Connect

    FRYE JM; ANASTOS HL; GUTIERREZ FC

    2012-06-07

    While several organic compounds were detected in the vapor samples used in the reenactment of the preparation of mounts from the extracts of nuclear grade high-efficiency particulate air filter fiberglass samples, the most significant species present in the samples were methylene chloride, phenol, phenol-d6, and 2-fluorophenol. These species were all known to be present in the extracts, but were expected to have evaporated during the preparation of the mounts, as the mounts appeared to be dry before any vapor was collected. These species were present at the following percentages of their respective occupational exposure limits: methylene chloride, 2%; phenol, 0.4%; and phenol-d6, 0.6%. However, there is no established limit for 2-fluorophenol. Several other compounds were detected at low levels for which, as in the case of 2-fluorophenol, there are no established permissible exposure limits. These compounds include 2-chlorophenol; N-nitroso-1-propanamine; 2-fluoro-1,1{prime}-biphenyl; 1,2-dihydroacenaphthylene; 2,5-cyclohexadiene-1,4-dione,2,6-bis(1,1-dimethylethyl); trimethyl oxirane; n-propylpropanamine; 2-(Propylamino)ethanol; 4-methoxy-1-butene; 6-methyl-5-hepten-2-one; and 3,4-dimethylpyridine. Some of these were among those added as surrogates or spike standards as part ofthe Advanced Technologies and Laboratories International, Inc. preparation ofthe extract of the HEPA filter media and are indicated as such in the data tables in Section 2, Results; other compounds found were not previously known to be present. The main inorganic species detected (sulfate, sodium, and sulfur) are also consistent with species added in the preparation of the methylene chloride extract of the high-efficiency particulate air sample.

  2. Assessment of the 3430 Building Filtered Exhaust Stack Sampling Probe Location

    SciTech Connect

    Glissmeyer, John A.; Flaherty, Julia E.

    2010-07-16

    Pacific Northwest National Laboratory performed a demonstration to determine the acceptable location in which to place an air sampling probe for emissions monitoring for radionuclides in the exhaust air discharge from the new 3430 Building Filtered Exhaust Stack. The method was to adopt the results of a previously performed test series for a system of similar configuration, followed by a partial test on the actual system to verify the applicability of previously performed tests. The qualification criteria included 1) a uniform air velocity, 2) an average flow angle that does not deviate from the axis of the duct by more than 20°, 3) a uniform concentration of tracer gases, and 4) a uniform concentration of tracer particles. Section 1 provides background information for the demonstration, and Section 2 describes the test strategy, including the criteria for the applicability of model results and the test matrix. Section 3 describes the flow -angle test and the velocity uniformity test, Section 4 provides the test results, and Section 5 provides the conclusions. Appendix A includes the test data sheets, and Appendix B gives applicable qualification results from the previously tested model stack. The data from the previously tested and similarly designed stack was demonstrated to be applicable to the current design for the 3430 Building Filtered Exhaust Stack. The 3430 stack was tested in both January and May of 2010 to document the results of several changes that were made to the exhaust system after the January tests. The 3430 stack meets the qualification criteria given in the American National Standards Institute/Health Physics Society N13.1 standard. Changes to the system configuration or operations outside of the bounds of this report (e.g., exhaust velocity increases, relocation of sample probe) will require retesting/reevaluation to determine compliancewith the requirements.

  3. Assessment of the Building 3430 Filtered Exhaust Stack Sampling Probe Location

    SciTech Connect

    Glissmeyer, John A.

    2010-04-13

    Pacific Northwest National Laboratory performed a demonstration to determine the acceptable location in which to place an air sampling probe for emissions monitoring for radionuclides in the exhaust air discharge from the new 3430 Building Filtered Pathway Stack . The method was to adopt the results of a previously performed test series for a system of similar configuration, followed by a partial test on the actual system to verify the applicability of previously performed tests. The qualification criteria included 1) a uniform air velocity, 2) an average flow angle that does not deviate from the axis of the duct by more than 20°, 3) a uniform concentration of tracer gases, and 4) a uniform concentration of tracer particles. Section 1 provides background information for the demonstration, and Section 2 describes the test strategy, including the criteria for the applicability of model results and the test matrix. Section 3 describes the flow angle test and the velocity uniformity test, Section 4 provides the test results, and Section 5 provides the conclusions. Appendix A includes the test data sheets, and Appendix B gives applicable qualification results from the previously tested model stack. The data from the previously tested and similarly designed stack was demonstrated to be applicable to the current design for the 3430 Building Filtered Pathway stack. Therefore, this new system also meets the qualification criteria given in the ANSI/HPS N13.1 standard. Changes to the system configuration or operations outside of the bounds of this report (e.g., exhaust velocity increases, relocation of sample probe) will require retesting/reevaluation to determine compliance to the requirements.

  4. Modeling ambient air concentrations of volatile organic compounds via digitally filtered FTIR spectra

    SciTech Connect

    Kaltenbach, T.

    1994-12-31

    As part of an agreement with the New York State Department of Environmental Conservation, Eastman Kodak Company has a program to monitor ambient air concentrations of volatile organic compounds at its fence lines. Currently, canister-based point sensors are used to collect a time-averaged sample every sixth day. The staff required to position, retrieve, and analyze these canisters makes this procedure expensive. Alternative methods are being investigated that can provide similar results in real time, while also saving costs. One such method is Fourier transform infrared (FTIR) spectroscopy. Radian Corporation performed a series of FTIR fence-line monitoring experiments at Kodak about one year ago. The spectra collected during this experiment are complicated by the presence of water vapor bands. Digital filtering techniques utilizing the Fourier transform are being explored as a means of removing the interference due to water vapor. When a digital filter is used as a spectral preprocessor, partial least squares (PLS) techniques can be employed to provide a powerful prediction pool. This seminar will describe the operation of the Fourier filters and present some encouraging preliminary results from PLS models.

  5. Evaluation of Urban Air Quality By Passive Sampling Technique

    NASA Astrophysics Data System (ADS)

    Nunes, T. V.; Miranda, A. I.; Duarte, S.; Lima, M. J.

    Aveiro is a flat small city in the centre of Portugal, close to the Atlantic coast. In the last two decades an intensive development of demographic, traffic and industry growth in the region was observed which was reflected on the air quality degrada- tion. In order to evaluate the urban air quality in Aveiro, a field-monitoring network by passive sampling with high space resolution was implemented. Twenty-four field places were distributed in a area of 3x3 Km2 and ozone and NO2 concentrations were measured. The site distribution density was higher in the centre, 250x250 m2 than in periphery where a 500x500 m2 grid was used. The selection of field places took into consideration the choice criteria recommendation by United Kingdom environmental authorities, and three tubes and a blank tube for each pollutant were used at each site. The sampling system was mounted at 3m from the ground usually profiting the street lampposts. Concerning NO2 acrylic tubes were used with 85 mm of length and an in- ternal diameter of 12mm, where in one of the extremities three steel grids impregnated with a solution of TEA were placed and fixed with a polyethylene end cup (Heal et al., 1999); PFA Teflon tube with 53 mm of length and 9 mm of internal diameter and three impregnated glass filters impregnated with DPE solution fixed by a teflon end cup was used for ozone sampling (Monn and Hargartner, 1990). The passive sampling method for ozone and nitrogen dioxide was compared with continuous measurements, but the amount of measurements wasnSt enough for an accurate calibration and validation of the method. Although this constraint the field observations (June to August 2001) for these two pollutants assign interesting information about the air quality in the urban area. A krigger method of interpolation (Surfer- Golden Software-2000) was applied to field data to obtain isolines distribution of NO2 and ozone concentration for the studied area. Even the used passive sampling method has many

  6. Ultrasonic extraction and field-portable anodic stripping voltammetry for the determination of lead in workplace air samples.

    PubMed

    Ashley, K; Mapp, K J; Millson, M

    1998-10-01

    An on-site, field-portable analytical method for the determination of lead in workplace air samples, based on the use of ultrasonic extraction and anodic stripping voltammetry (ASV), was evaluated. Workplace air samples were obtained using a standard method involving particulate collection onto mixed cellulose ester membrane filters. Samples were collected at work sites where airborne particulates were generated from the abrasive blasting of lead-containing paint on highway bridges. Ultrasonic extraction (UE) of air filter samples in diluted nitric acid, followed by portable ASV, was used for the determination of lead. Also, performance evaluation samples consisting of reference materials of known lead concentration were subjected to the UE-ASV procedure for lead determination. Confirmatory analyses of the air filters and performance evaluation samples subjected to the UE-ASV lead measurement method were conducted by hotplate digestion in concentrated nitric acid and 30% hydrogen peroxide, followed by inductively coupled plasma-atomic emission spectrometric (ICP-AES) determination of lead. Recoveries of lead from performance evaluation materials (when using the UE-ASV method) were found to be quantitative. The performance of the UE-ASV method for lead in air filters was found to be acceptable, as evaluated by comparison with results from hotplate strong acid digestion followed by ICP-AES analysis. Based on the results of this study, the ultrasonic extraction/portable ASV procedure demonstrates potential for the on-site determination of lead in personal breathing zone and area air samples. PMID:9794065

  7. Sizing alpha emitting particles of aged plutonium on personal air sampler filters using CR-39 autoradiography.

    PubMed

    Richardson, R B; Hegyi, G; Starling, S C

    2003-01-01

    Methods have been developed to assess the size distribution of alpha emitting particles of reactor fuel of known composition captured on air sampler filters. The sizes of uranium oxide and plutonium oxide particles were determined using a system based on CR-39 solid-state nuclear track detectors. The CR-39 plastic was exposed to the deposited particles across a 400 microm airgap. The exposed CR-39 was chemically etched to reveal clusters of tracks radially dispersed from central points. The number and location of the tracks were determined using an optical microscope with an XY motorised table and image analysis software. The sample mounting arrangement allowed individual particles to be simultaneously viewed with their respective track cluster. The predicted diameters correlated with the actual particle diameters, as measured using the optical microscope. The efficacy of the technique was demonstrated with particles of natural uranium oxide (natUO2) of known size, ranging from 4 to 150 microm in diameter. Two personal air sampler (PAS) filters contaminated with actinide particles were placed against CR-39 and estimated to have size distributions of 0.8 and 1.0 microm activity median aerodynamic diameter (AMAD). PMID:14526944

  8. Effect of Intake Air Filter Condition on Light-Duty Gasoline Vehicles

    SciTech Connect

    Thomas, John F; Huff, Shean P; West, Brian H; Norman, Kevin M

    2012-01-01

    Proper maintenance can help vehicles perform as designed, positively affecting fuel economy, emissions, and the overall drivability. This effort investigates the effect of one maintenance factor, intake air filter replacement, with primary focus on vehicle fuel economy, but also examining emissions and performance. Older studies, dealing with carbureted gasoline vehicles, have indicated that replacing a clogged or dirty air filter can improve vehicle fuel economy and conversely that a dirty air filter can be significantly detrimental to fuel economy. The effect of clogged air filters on the fuel economy, acceleration and emissions of five gasoline fueled vehicles is examined. Four of these were modern vehicles, featuring closed-loop control and ranging in model year from 2003 to 2007. Three vehicles were powered by naturally aspirated, port fuel injection (PFI) engines of differing size and cylinder configuration: an inline 4, a V6 and a V8. A turbocharged inline 4-cylinder gasoline direct injection (GDI) engine powered vehicle was the fourth modern gasoline vehicle tested. A vintage 1972 vehicle equipped with a carburetor (open-loop control) was also examined. Results reveal insignificant fuel economy and emissions sensitivity of modern vehicles to air filter condition, but measureable effects on the 1972 vehicle. All vehicles experienced a measured acceleration performance penalty with clogged intake air filters.

  9. Ultrafine particle removal by residential heating, ventilating, and air-conditioning filters.

    PubMed

    Stephens, B; Siegel, J A

    2013-12-01

    This work uses an in situ filter test method to measure the size-resolved removal efficiency of indoor-generated ultrafine particles (approximately 7-100 nm) for six new commercially available filters installed in a recirculating heating, ventilating, and air-conditioning (HVAC) system in an unoccupied test house. The fibrous HVAC filters were previously rated by the manufacturers according to ASHRAE Standard 52.2 and ranged from shallow (2.5 cm) fiberglass panel filters (MERV 4) to deep-bed (12.7 cm) electrostatically charged synthetic media filters (MERV 16). Measured removal efficiency ranged from 0 to 10% for most ultrafine particles (UFP) sizes with the lowest rated filters (MERV 4 and 6) to 60-80% for most UFP sizes with the highest rated filter (MERV 16). The deeper bed filters generally achieved higher removal efficiencies than the panel filters, while maintaining a low pressure drop and higher airflow rate in the operating HVAC system. Assuming constant efficiency, a modeling effort using these measured values for new filters and other inputs from real buildings shows that MERV 13-16 filters could reduce the indoor proportion of outdoor UFPs (in the absence of indoor sources) by as much as a factor of 2-3 in a typical single-family residence relative to the lowest efficiency filters, depending in part on particle size. PMID:23590456

  10. Backflushing Filters for Field Processing of Water Samples Prior to Trace-Element Analyses

    USGS Publications Warehouse

    Kennedy, V.C.; Jenne, E.A.; Burchard, J.M.

    1976-01-01

    A portable unit is described for filtering water samples at field sites in such a manner that the filtrate is suitable for analysis not only of major constituents but also of trace elments at the mocrogram-per-liter level. A battery-operated peristaltic pump forces the water sample through medical-grade silicone tubing into and through an all-plastic in-line filter which can be backflushed when sediment clogs the filter membrane. Initial filtration rate exceeds 500 milliliter/minute and, because of the backflushing feature, a total time for filtering high-sediment-bearing waster samples is greatly reduced. (Woodard-USGS)

  11. 40 CFR 53.57 - Test for filter temperature control during sampling and post-sampling periods.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... energy distribution and permitted tolerances specified in table E-2 of this subpart. The solar radiation... (40 CFR part 50, appendix L, figure L-30) or equivalent adaptor to facilitate measurement of sampler... recommended. (6) Sample filter or filters, as specified in section 6 of 40 CFR part 50, appendix L....

  12. 40 CFR 53.57 - Test for filter temperature control during sampling and post-sampling periods.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... energy distribution and permitted tolerances specified in table E-2 of this subpart. The solar radiation... (40 CFR part 50, appendix L, figure L-30) or equivalent adaptor to facilitate measurement of sampler... recommended. (6) Sample filter or filters, as specified in section 6 of 40 CFR part 50, appendix L....

  13. 40 CFR 53.57 - Test for filter temperature control during sampling and post-sampling periods.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (40 CFR part 50, appendix L, figure L-30) or equivalent adaptor to facilitate measurement of sampler... recommended. (6) Sample filter or filters, as specified in section 6 of 40 CFR part 50, appendix L. (d... calibration, certification of calibration accuracy, and NIST-traceability (if required) of all...

  14. Venturi Air-Jet Vacuum Ejector For Sampling Air

    NASA Technical Reports Server (NTRS)

    Hill, Gerald F.; Sachse, Glen W.; Burney, L. Garland; Wade, Larry O.

    1990-01-01

    Venturi air-jet vacuum ejector pump light in weight, requires no electrical power, does not contribute heat to aircraft, and provides high pumping speeds at moderate suctions. High-pressure motive gas required for this type of pump bled from compressor of aircraft engine with negligible effect on performance of engine. Used as source of vacuum for differential-absorption CO-measurement (DACOM), modified to achieve in situ measurements of CO at frequency response of 10 Hz. Provides improvement in spatial resolution and potentially leads to capability to measure turbulent flux of CO by use of eddy-correlation technique.

  15. Fungal colonization of air filters and insulation in a multi-story office building: production of volatile organics

    NASA Technical Reports Server (NTRS)

    Ahearn, D. G.; Crow, S. A.; Simmons, R. B.; Price, D. L.; Mishra, S. K.; Pierson, D. L.

    1997-01-01

    Secondary air filters in the air-handling units on four floors of a multi-story office building with a history of fungal colonization of insulation within the air distribution system were examined for the presence of growing fungi and production of volatile organic compounds. Fungal mycelium and conidia of Cladosporium and Penicillium spp. were observed on insulation from all floors and both sides of the air filters from one floor. Lower concentrations of volatile organics were released from air filter medium colonized with fungi as compared with noncolonized filter medium. However, the volatiles from the colonized filter medium included fungal metabolites such as acetone and a carbonyl sulfide-like compound that were not released from noncolonized filter medium. The growth of fungi in air distribution systems may affect the content of volatile organics in indoor air.

  16. An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples

    NASA Astrophysics Data System (ADS)

    Yttri, K. E.; Schnelle-Kreiss, J.; Maenhaut, W.; Alves, C.; Bossi, R.; Bjerke, A.; Claeys, M.; Dye, C.; Evtyugina, M.; García-Gacio, D.; Gülcin, A.; Hillamo, R.; Hoffer, A.; Hyder, M.; Iinuma, Y.; Jaffrezo, J.-L.; Kasper-Giebl, A.; Kiss, G.; López-Mahia, P. L.; Pio, C.; Piot, C.; Ramirez-Santa-Cruz, C.; Sciare, J.; Teinilä, K.; Vermeylen, R.; Vicente, A.; Zimmermann, R.

    2014-07-01

    The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wild fire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for biomass burning particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied High-Performance Anion-Exchange Chromatography (HPAEC), four used High-Performance Liquid Chromatography (HPLC) or Ultra-Performance Liquid Chromatography (UPLC), and six resorted to Gas Chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 23%; however, for 62% of the laboratories the mean PE was within ±10%, and for 85% the mean PE was within ±20%. For mannosan, the corresponding range was -60 to 69%, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e., for 33% of

  17. An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples

    NASA Astrophysics Data System (ADS)

    Yttri, K. E.; Schnelle-Kreis, J.; Maenhaut, W.; Abbaszade, G.; Alves, C.; Bjerke, A.; Bonnier, N.; Bossi, R.; Claeys, M.; Dye, C.; Evtyugina, M.; García-Gacio, D.; Hillamo, R.; Hoffer, A.; Hyder, M.; Iinuma, Y.; Jaffrezo, J.-L.; Kasper-Giebl, A.; Kiss, G.; López-Mahia, P. L.; Pio, C.; Piot, C.; Ramirez-Santa-Cruz, C.; Sciare, J.; Teinilä, K.; Vermeylen, R.; Vicente, A.; Zimmermann, R.

    2015-01-01

    The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning (BB) aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wildfire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for BB particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied high-performance anion-exchange chromatography (HPAEC), four used high-performance liquid chromatography (HPLC) or ultra-performance liquid chromatography (UPLC) and six resorted to gas chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 20%; however, for 62% of the laboratories the mean PE was within ±10%, and for 85% the mean PE was within ±20%. For mannosan, the corresponding range was -60 to 69%, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e. for 33% of the

  18. Thermodesorption of aerosol matter on multiple filters of different materials for a more detailed evaluation of sampling artifacts

    NASA Astrophysics Data System (ADS)

    Wittmaack, Klaus; Keck, Lothar

    2004-10-01

    Multiple, essentially identical samples of PM2.5, PM10 and TSP aerosol matter were collected on filters of cellulose acetate-nitrate membrane (CA), quartz fiber (QF) and glass fiber (GF) material. The samples were analyzed in terms of the gravimetric mass and the mass of nine inorganic ions. These parameters were also measured after step-wise thermodesorption of aerosol matter by 1-h heating in ambient air up to 350 °C. The observed thermograms of the analyzed ions were compared with results obtained using pure and mixed salts on filter. In summer the apparent mass concentration of aerosol matter collected on CA was always larger than on QF and GF filter. The excess mass on CA was found to be highly volatile, i.e. completely removable at 120 °C, and composed of both ionic and non-ionic matter. The apparent nitrate concentration sampled on QF and GF was almost an order of magnitude lower than on CA. The very pronounced nitrate losses from the fiber filters are attributed to volatilization of ammonium nitrate. In contrast, nitrate losses from CA were small or even negligible for two reasons, pile-up of aerosol matter predominantly on (rather than in) the filter ("cake" formation) and, more importantly, re-adsorption of volatilized ammonia and nitric acid in the filter. Sampling on GF filters was found to suffer from severe problems due to chemical reactions between Na+ of the glass and SO42- of the aerosol matter. A novel type of artifact was observed in sampling campaigns during fall. Presumably as a results of a high water content, the collected aerosol matter became liquefied and a large fraction of the water soluble components was driven through the filter into the support pad underneath. The negative "wetting artifact" was much more pronounced for the thin CA than for the relatively thick QF filters. The total amount of aerosol matter in the CA/pad and QF/pad combinations was the same, indicating that this kind of artifact can be corrected for. Ammonium

  19. Mold colonization during use of preservative-treated and untreated air filters, including HEPA filters from hospitals and commercial locations over an 8-year period (1996-2003).

    PubMed

    Price, Daniel L; Simmons, Robert B; Crow, Sidney A; Ahearn, Donald G

    2005-07-01

    High efficiency particulate arrestance (HEPA; 99.97% efficient at 0.3 microm) filters, filters with ASHRAE particulate arrestance rating of 90-95% at 1 mum (90-95% filters), and lower efficiency cellulosic-polyester filters from air conditioning systems in hospitals and commercial buildings were removed from the systems and examined microscopically for mold colonization. Cellulosic-type filters from systems with water entrainment problems typically were colonized, or became colonized upon incubation in moisture chambers. Species of Acremonium, Aspergillus, and Cladosporium were most common. With air filters of all types, treatment of filter media with an antimicrobial preservative tended to reduce or delay colonization. Mold colonization of HEPA and 90-95% filters was observed most often on the load surfaces, but two untreated HEPA filters were permeated with fungi, one with Aspergillus flavus, the other with Cladosporium sp. Air filters in heating, ventilating, and air conditioning (HVAC) systems, particularly those with chronic or periodic exposure to moisture, may serve as point sources for indoor molds. PMID:15856351

  20. Thoron ( 220Rn) progeny reduction by an air cleaner of the polarized media filter type

    NASA Astrophysics Data System (ADS)

    Bigu, J.

    1993-02-01

    The effect of an air cleaner on 220Rn progeny atmospheres has been studied in a Radon/Thoron Test Facility (RTTF) of the walk-in type. The air cleaner consists basically of a fan and a special filter material sandwiched between two metal screens, to which an electric field is applied. The filter is of the polarized media type and uses fibreglass as material. The fan and filter system are housed in a metal case. Air is drawn from the back of the case by means of the fan and forced through the "electrical" filter where removal of the 220Rn progeny occurs. Radon-220 progeny "depleted" air is discharged at the top of the device. Tests were conducted in 220Rn/ 220Rn progeny atmospheres when the air cleaner was operating, and when it was turned off. Very pronounced effects were observed during the operation of the device, namely: a dramatic decrease in the 220Rn progeny concentrations and the total aerosol concentration, as well as a large increase in the 220Rn progeny unattached fractions and the plate-out of these radionuclides on the walls of the RTTF. The air cleaner has potential in industrial applications, which should be explored.

  1. Efficiency of automotive cabin air filters to reduce acute health effects of diesel exhaust in human subjects

    PubMed Central

    Rudell, B.; Wass, U.; Horstedt, P.; Levin, J. O.; Lindahl, R.; Rannug, U.; Sunesson, A. L.; Ostberg, Y.; Sandstrom, T.

    1999-01-01

    OBJECTIVES: To evaluate the efficiency of different automotive cabin air filters to prevent penetration of components of diesel exhaust and thereby reduce biomedical effects in human subjects. Filtered air and unfiltered diluted diesel exhaust (DDE) were used as negative and positive controls, respectively, and were compared with exposure to DDE filtered with four different filter systems. METHODS: 32 Healthy non- smoking subjects (age 21-53) participated in the study. Each subject was exposed six times for 1 hour in a specially designed exposure chamber: once to air, once to unfiltered DDE, and once to DDE filtered with the four different cabin air filters. Particle concentrations during exposure to unfiltered DDE were kept at 300 micrograms/m3. Two of the filters were particle filters. The other two were particle filters combined with active charcoal filters that might reduce certain gaseous components. Subjective symptoms were recorded and nasal airway lavage (NAL), acoustic rhinometry, and lung function measurements were performed. RESULTS: The two particle filters decreased the concentrations of diesel exhaust particles by about half, but did not reduce the intensity of symptoms induced by exhaust. The combination of active charcoal filters and a particle filter significantly reduced the symptoms and discomfort caused by the diesel exhaust. The most noticable differences in efficacy between the filters were found in the reduction of detection of an unpleasant smell from the diesel exhaust. In this respect even the two charcoal filter combinations differed significantly. The efficacy to reduce symptoms may depend on the abilities of the filters investigated to reduce certain hydrocarbons. No acute effects on NAL, rhinometry, and lung function variables were found. CONCLUSIONS: This study has shown that the use of active charcoal filters, and a particle filter, clearly reduced the intensity of symptoms induced by diesel exhaust. Complementary studies on vehicle

  2. Roll-to-Roll Transfer of Electrospun Nanofiber Film for High-Efficiency Transparent Air Filter.

    PubMed

    Xu, Jinwei; Liu, Chong; Hsu, Po-Chun; Liu, Kai; Zhang, Rufan; Liu, Yayuan; Cui, Yi

    2016-02-10

    Particulate matter (PM) pollution in air has become a serious environmental issue calling for new type of filter technologies. Recently, we have demonstrated a highly efficient air filter by direct electrospinning of polymer fibers onto supporting mesh although its throughput is limited. Here, we demonstrate a high throughput method based on fast transfer of electrospun nanofiber film from roughed metal foil to a receiving mesh substrate. Compared with the direct electrospinning method, the transfer method is 10 times faster and has better filtration performance at the same transmittance, owing to the uniformity of transferred nanofiber film (>99.97% removal of PM2.5 at ∼73% of transmittance). With these advantages, large area freestanding nanofiber film and roll-to-roll production of air filter are demonstrated. PMID:26789781

  3. Air Sampling System for use in monitoring viable and non-viable particulate air quality under dynamic operating conditions of blow/fill/seal processing.

    PubMed

    Probert, Steve; Sinclair, Colin S; Tallentire, Alan

    2002-01-01

    An Air Sampling Link (ASL), employed in conjunction with an Air Sampling Device (ASD) or a laser particle counter, has been developed for sampling flowing air for viable and non-viable particulate analyses. Typically, the ASL could be used to sample filtered air supplied to an air shower of a Blow/Fill/Seal machine operating in the dynamic state. The ASL allows sample volumes of air to be taken from flowing air without significant loss from the sample flow of airborne particles possessing aerodynamic sizes relevant to those found in practice. The link has no moving parts, is steam sterilizable in-situ, and allows for the taking of continuous samples of air without the need for intervention into the 'critical zone' of the filling machine. This article describes (i) the design criteria for the ASL and the ASD, (ii) the rationale underlying the concept of the ASL design, (iii) the collection performance of the ASL against that of a conventional sampling arrangement, and (iv) a functionality assessment of the ASL-based sampling system installed on a Rommelag style 305 B/F/S machine over a seven week period. PMID:12404722

  4. APPLICATION OF SEMIPERMEABLE MEMBRANE DEVICES TO INDOOR AIR SAMPLING

    EPA Science Inventory

    Semipermeable membrane devices (SPMDs) are a relatively new passive sampling technique for nonpolar organic compounds that have been extensively used for surface water sampling. A small body of literature indicates that SPMDs are also useful for air sampling. Because SPMDs ha...

  5. METHODS TO SAMPLE AIR BORNE PROPAGULES OF ASPERGILLUS FLAVUS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several techniques (cyclone samplers, filter samplers and rotorods) were evaluated for detection of airborne Aspergillus flavus Link propagules in a cultivated region of southwest Arizona. Cyclone samplers operated continuously for 168 h (7 d) collected a dry sample that was ideal for quantificatio...

  6. Evaluation of a Multiwavelength Characterization of Brown and Black Carbon from Filter Samples

    NASA Astrophysics Data System (ADS)

    Johnson, Megan M.

    An ultraviolet -- visible (UV-VIS) spectrometer coupled with an integrating sphere was used to measure diffuse reflectance and transmittance of particulate matter (PM) samples collected on quartz-fiber (QF) and Teflon-membrane (TM) filter media over the wavelength range 250 -- 1000 nm at 1 nm resolution. These measurements were used to calculate PM sample attenuation, absorption, and Angstrom absorption exponents (AAE). Samples included laboratory generated source samples (e.g. biomass burning emissions, diesel engine exhaust, and resuspended dusts) and ambient samples. PM sample attenuation and absorption were compared to other PM light absorption measurement methods including densitometer, dual-wavelength (370 & 880 nm) transmissometer, and 3-lambda (405, 532, 781 nm) photoacoustic spectrometer (PAS). Large differences were found between filter-based methods and QF and TM absorption was found to be higher than PAS by average factors of 5.1 and 3.6, respectively. AAE values calculated for all samples compared well with values previously reported in literature. Comparison of the filter media showed that attenuation and absorption values from TM samples are, on average, ˜1/2 of the values obtained using QF samples. Filter media comparison also revealed evidence of shadowing effects on TM filter media with high sample loading. Comparison of absorption approximation methods using various AAEs and a power law extrapolation exhibited large differences in radiative forcing estimates, indicating that PM absorption is not always well represented by the power law assumption.

  7. Solid waste transuranic storage and assay facility indoor air sampling

    SciTech Connect

    Pingel, L.A., Westinghouse Hanford

    1996-08-20

    The purpose of the study is to collect and analyze samples of the indoor air at the Transuranic Storage and Assay Facility (TRUSAF), Westinghouse Hanford. A modified US EPA TO-14 methodology, using gas chromatography/mass spectrography, may be used for the collection and analysis of the samples. The information obtained will be used to estimate the total release of volatile organic compounds from TRUSAF to determine the need for air emmission permits.

  8. Radioactive air emissions notice of construction for HEPA filtered vacuum radioactive air emission units

    SciTech Connect

    Johnson, R.E.

    1997-10-27

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health (WDOH) for the use of vacuums on the Hanford Site. These previous agreements/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant. Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year. This application is intended to request sitewide approval for the new activities, and provide an option for any facility on the site to use this approval, within the terms of this NOC. The HVUs used in accordance with this NOC will support reduction of radiological contamination at various locations on the Hanford Site. Radiation Protection Air

  9. Radioactive air emissions notice of construction HEPA filtered vacuum radioactive air emission units

    SciTech Connect

    JOHNSON, R.E.

    1999-09-01

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health for the use of vacuums on the Hanford Site. These previous agreement/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex (routine technical meeting 12/10/96) and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant (routine technical meeting 06/25/96). Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year.

  10. First report of Legionella pneumophila in car cabin air filters. Are these a potential exposure pathway for professional drivers?

    PubMed

    Alexandropoulou, Ioanna G; Konstantinidis, Theocharis G; Parasidis, Theodoros A; Nikolaidis, Christos; Panopoulou, Maria; Constantinidis, Theodoros C

    2013-12-01

    Recent findings have identified professional drivers as being at an increased risk of Legionnaires' disease. Our hypothesis was that used car cabin air filters represent a reservoir of Legionella bacteria, and thus a potential pathway for contamination. We analysed used cabin air filters from various types of car. The filters were analysed by culture and by molecular methods. Our findings indicated that almost a third of air filters were colonized with Legionella pneumophila. Here, we present the first finding of Legionella spp. in used car cabin air filters. Further investigations are needed in order to confirm this exposure pathway. The presence of Legionella bacteria in used cabin air filters may have been an unknown source of infection until now. PMID:24099652

  11. Bacterial filtration efficiency of green soy protein based nanofiber air filter.

    PubMed

    Lubasova, D; Netravali, A; Parker, J; Ingel, B

    2014-07-01

    High bacterial filtration efficiency (BFE) filters, based on nanofibers derived from blends of grain proteins and poly-ethylene-oxide (PEO), were produced by an electrospinning process. Specifically, polymer blends consisting of purified soy flour/PEO with a ratio of 7/3 were spun into nanofibers and characterized. A new laboratory based experimental apparatus for testing BFE was designed and used to test BFE of bacterial aerosols consisting of Escherichia coli (E. coli). Performances of soy protein based nanofiber filters with nanofiber mass varying from 1 to 5 g/m2 as well as a nanofiber filters prepared from pure PEO were compared. The results showed that BFE values for filters containing 5 g/m2 protein based nanofibers and PEO nanofiber filter were 100 and 81.5%, respectively. The results also indicated that the BFE increased as the protein content in the nanofiber filter increased. These novel protein based nanofiber filters have demonstrated a clear potential for effective removal and retention of E. coli bacteria during air-filtration. These filters can be effectively deployed in environments such as hospitals and senior residential areas to reduce bacterial infections. PMID:24757959

  12. Concepts for Environmental Radioactive Air Sampling and Monitoring

    SciTech Connect

    Barnett, J. Matthew

    2011-11-04

    Environmental radioactive air sampling and monitoring is becoming increasingly important as regulatory agencies promulgate requirements for the measurement and quantification of radioactive contaminants. While researchers add to the growing body of knowledge in this area, events such as earthquakes and tsunamis demonstrate how nuclear systems can be compromised. The result is the need for adequate environmental monitoring to assure the public of their safety and to assist emergency workers in their response. Two forms of radioactive air monitoring include direct effluent measurements and environmental surveillance. This chapter presents basic concepts for direct effluent sampling and environmental surveillance of radioactive air emissions, including information on establishing the basis for sampling and/or monitoring, criteria for sampling media and sample analysis, reporting and compliance, and continual improvement.

  13. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, BHA GROUP, INC., QP131 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  14. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, POLYMER GROUP, INC., DURAPEX PET FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  15. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, TETRATEC PTFE PRODUCTS, TETRATEX 6212 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  16. Level-1C Product from AIRS: Principal Component Filtering

    NASA Technical Reports Server (NTRS)

    Manning, Evan M.; Jiang, Yibo; Aumann, Hartmut H.; Elliott, Denis A.; Hannon, Scott

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS), launched on the EOS Aqua spacecraft on May 4, 2002, is a grating spectrometer with 2378 channels in the range 3.7 to 15.4 microns. In a grating spectrometer each individual radiance measurement is largely independent of all others. Most measurements are extremely accurate and have very low noise levels. However, some channels exhibit high noise levels or other anomalous behavior, complicating applications needing radiances throughout a band, such as cross-calibration with other instruments and regression retrieval algorithms. The AIRS Level-1C product is similar to Level-1B but with instrument artifacts removed. This paper focuses on the "cleaning" portion of Level-1C, which identifies bad radiance values within spectra and produces substitute radiances using redundant information from other channels. The substitution is done in two passes, first with a simple combination of values from neighboring channels, then with principal components. After results of the substitution are shown, differences between principal component reconstructed values and observed radiances are used to investigate detailed noise characteristics and spatial misalignment in other channels.

  17. Development of the sampling and nuclide analysis methods for spent HEPA filter wastes

    SciTech Connect

    Young-Yong Ji; Dae Seok Hong; Il-Sik Kang; Bum-Kyoung Seo; Jong-Sik Shon

    2007-07-01

    Spent filter wastes of about 2,160 units have been stored in the waste storage facility of the Korea Atomic Energy Research Institute since its operation. These spent filters have generally consisted of a HEPA filter after its filtering of all the contaminants in the gas stream generated during the operation of the HANARO research reactor and the nuclear fuel cycle facilities. At the moment, to secure enough storage space, it is necessary to make a volume reduction of the stored radioactive wastes through a compression treatment or a regulatory clearance. There have been many studies on a treatment and a clearance of the low level radioactive wastes generated from nuclear facilities. These methods are used in view of a reduction of a management cost and disposal cost and the security of free space for a waste storage facility approaching saturation. In order to dispose of the spent filters, it is first necessary to conduct a radionuclide assessment of them. To do that, a sampling procedure should be prepared to obtain a representative sample from a spent filter. As for conducting a nuclide analysis for this representative sample, a corresponding spent filter can be determined as either a regulatory clearance waste or a radioactive waste. (authors)

  18. Investigation of storage-phosphor autoradiography for the rapid quantitative screening of air filters for emergency response purposes

    NASA Astrophysics Data System (ADS)

    Gallardo, Athena Marie

    Past nuclear accidents, such as Chernobyl, resulted in a large release of radionuclides into the atmosphere. Radiological assessment of the vicinity of the site of the incident is vital to assess the exposure levels and dose received by the population and workers. Therefore, it is critical to thoroughly understand the situation and risks associated with a particular event in a timely manner in order to properly manage the event. Current atmospheric radiological assessments of alpha emitting radioisotopes include acquiring large quantities of air samples, chemical separation of radionuclides, sample mounting, counting through alpha spectrometry, and analysis of the data. The existing methodology is effective, but time consuming and labor intensive. Autoradiography, and the properties of phosphor imaging films, may be used as an additional technique to facilitate and expedite the alpha analysis process in these types of situations. Although autoradiography is not as sensitive to alpha radiation as alpha spectrometry, autoradiography may benefit alpha analysis by providing information about the activity as well as the spatial distribution of radioactivity in the sample under investigation. The objective for this research was to develop an efficient method for quantification and visualization of air filter samples taken in the aftermath of a nuclear emergency through autoradiography using 241Am and 239Pu tracers. Samples containing varying activities of either 241Am or 239Pu tracers were produced through microprecipitation and assayed by alpha spectroscopy. The samples were subsequently imaged and an activity calibration curve was produced by comparing the digital light units recorded from the image to the known activity of the source. The usefulness of different phosphor screens was examined by exposing each type of film to the same standard nuclide for varying quantities of time. Unknown activity samples created through microprecipiation containing activities of

  19. CHEMICAL REMOVAL OF BIOMASS FROM WASTE AIR BIOTRICKLING FILTERS: SCREENING CHEMICALS OF POTENTIAL INTEREST. (R825392)

    EPA Science Inventory

    A protocol was developed to rapidly assess the efficiency of chemical washing for the removal of excess biomass from biotrickling filters for waste air treatment. Although the experiment was performed on a small scale, conditions were chosen to simulate application in full-scale ...

  20. Modeling the Air Flow in the 3410 Building Filtered Exhaust Stack System

    SciTech Connect

    Recknagle, Kurtis P.; Barnett, J. Matthew; Suffield, Sarah R.

    2013-01-23

    Additional ventilation capacity has been designed for the 3410 Building filtered exhaust stack system. The updated system will increase the number of fans from two to three and will include ductwork to incorporate the new fan into the existing stack. Stack operations will involve running various two-fan combinations at any given time. The air monitoring system of the existing two-fan stack was previously found to be in compliance with the ANSI/HPS N13.1-1999 standard, however it is not known if the modified (three-fan) system will comply. Subsequently, a full-scale three-dimensional (3-D) computational fluid dynamics (CFD) model of the modified stack system has been created to examine the sampling location for compliance with the standard. The CFD modeling results show good agreement with testing data collected from the existing 3410 Building stack and suggest that velocity uniformity and flow angles will remain well within acceptance criteria when the third fan and associated ductwork is installed. This includes two-fan flow rates up to 31,840 cfm for any of the two-fan combinations. For simulation cases in which tracer gas and particles are introduced in the main duct, the model predicts that both particle and tracer gas coefficients of variance (COVs) may be larger than the acceptable 20 percent criterion of the ANSI/HPS N13.1-1999 standard for each of the two-fan, 31,840 cfm combinations. Simulations in which the tracers are introduced near the fans result in improved, though marginally acceptable, COV values for the tracers. Due to the remaining uncertainty that the stack will qualify with the addition of the third fan and high flow rates, a stationary air blender from Blender Products, Inc. is considered for inclusion in the stack system. A model of the air blender has been developed and incorporated into the CFD model. Simulation results from the CFD model that includes the air blender show striking improvements in tracer gas mixing and tracer particle

  1. Presence of organophosphorus pesticide oxygen analogs in air samples

    PubMed Central

    Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2012-01-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (< 30 ng/m3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity

  2. Presence of organophosphorus pesticide oxygen analogs in air samples

    NASA Astrophysics Data System (ADS)

    Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Galvin, Kit; Tchong-French, Maria; Yu, Jianbo

    2013-02-01

    A number of recent toxicity studies have highlighted the increased potency of oxygen analogs (oxons) of several organophosphorus (OP) pesticides. These findings were a major concern after environmental oxons were identified in environmental samples from air and surfaces following agricultural spray applications in California and Washington State. This paper reports on the validity of oxygen analog measurements in air samples for the OP pesticide, chlorpyrifos. Controlled environmental and laboratory experiments were used to examine artificial formation of chlorpyrifos-oxon using OSHA Versatile Sampling (OVS) tubes as recommended by NIOSH method 5600. Additionally, we compared expected chlorpyrifos-oxon attributable to artificial transformation to observed chlorpyrifos-oxon in field samples from a 2008 Washington State Department of Health air monitoring study using non-parametric statistical methods. The amount of artificially transformed oxon was then modeled to determine the amount of oxon present in the environment. Toxicity equivalency factors (TEFs) for chlorpyrifos-oxon were used to calculate chlorpyrifos-equivalent air concentrations. The results demonstrate that the NIOSH-recommended sampling matrix (OVS tubes with XAD-2 resin) was found to artificially transform up to 30% of chlorpyrifos to chlorpyrifos-oxon, with higher percentages at lower concentrations (<30 ng m-3) typical of ambient or residential levels. Overall, the 2008 study data had significantly greater oxon than expected by artificial transformation, but the exact amount of environmental oxon in air remains difficult to quantify with the current sampling method. Failure to conduct laboratory analysis for chlorpyrifos-oxon may result in underestimation of total pesticide concentration when using XAD-2 resin matrices for occupational or residential sampling. Alternative methods that can accurately measure both OP pesticides and their oxygen analogs should be used for air sampling, and a toxicity

  3. Air Sample Conditioner Helps the Waste Treatment Plant Meet Emissions Standards

    SciTech Connect

    Glissmeyer, John A.; Flaherty, Julia E.; Pekour, Mikhail S.

    2014-12-02

    The air in three of the Hanford Site Waste Treatment and Immobilization Plant (WTP) melter off-gas discharge stacks will be hot and humid after passing through the train of emission abatement equipment. The off-gas temperature and humidity levels will be incompatible with the airborne emissions monitoring equipment required for this type of stack. To facilitate sampling from these facilities, an air sample conditioner system will be installed to introduce cool, dry air into the sample stream to reduce the temperature and dew point. This will avoid thermal damage to the instrumentation and problematic condensation. The complete sample transport system must also deliver at least 50% of the particles in the sample airstream to the sample collection and on-line analysis equipment. The primary components of the sample conditioning system were tested in a laboratory setting. The sample conditioner itself is based on a commercially-available porous tube filter design. It consists of a porous sintered metal tube inside a coaxial metal jacket. The hot gas sample stream passes axially through the porous tube, and the dry, cool air is injected into the jacket and through the porous wall of the inner tube, creating an effective sample diluter. The dilution and sample air mix along the entire length of the porous tube, thereby simultaneously reducing the dew point and temperature of the mixed sample stream. Furthermore, because the dilution air enters through the porous tube wall, the sample stream does not come in contact with the porous wall and particle deposition is reduced in this part of the sampling system. Tests were performed with an environmental chamber to supply air with the temperature and humidity needed to simulate the off-gas conditions. Air from the chamber was passed through the conditioning system to test its ability to reduce the temperature and dew point of the sample stream. To measure particle deposition, oil droplets in the range of 9 to 11 micrometer

  4. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 42 Public Health 1 2012-10-01 2012-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  5. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 1 2011-10-01 2011-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  6. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  7. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 1 2013-10-01 2013-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  8. 42 CFR 84.1143 - Dust, fume, and mist air-purifying filter tests; performance requirements; general.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 1 2014-10-01 2014-10-01 false Dust, fume, and mist air-purifying filter tests; performance requirements; general. 84.1143 Section 84.1143 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF... Efficiency Respirators and Combination Gas Masks § 84.1143 Dust, fume, and mist air-purifying filter...

  9. THE REAL ISSUE WITH WALL DEPOSITS IN CLOSED FILTER CASSETTES - WHAT'S THE SAMPLE?

    SciTech Connect

    Brisson, M.

    2009-09-12

    The measurement of aerosol dusts has long been utilized to assess the exposure of workers to metals. Tools used to sample and measure aerosol dusts have gone through many transitions over the past century. In particular, there have been several different techniques used to sample for beryllium, not all of which might be expected to produce the same result. Today, beryllium samples are generally collected using filters housed in holders of several different designs, some of which are expected to produce a sample that mimics the human capacity for dust inhalation. The presence of dust on the interior walls of cassettes used to hold filters during metals sampling has been discussed in the literature for a number of metals, including beryllium, with widely varying data. It appears that even in the best designs, particulates can enter the sampling cassette and deposit on the interior walls rather than on the sampling medium. The causes are not well understood but are believed to include particle bounce, electrostatic forces, particle size, particle density, and airflow turbulence. Historically, the filter catch has been considered to be the sample, but the presence of wall deposits, and the potential that the filter catch is not representative of the exposure to the worker, puts that historical position into question. This leads to a fundamental question: What is the sample? This article reviews the background behind the issue, poses the above-mentioned question, and discusses options and a possible path forward for addressing that question.

  10. Innovations in air sampling to detect plant pathogens

    PubMed Central

    West, JS; Kimber, RBE

    2015-01-01

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

  11. High sensitivity gamma spectrometry of air samples near SRS during 1985-1995

    SciTech Connect

    Winn, W.G.; Cadieux, J.R.

    1997-07-01

    High sensitivity gamma analysis of off-site air samples near the Savannah River Site (SRS) is achieved by collecting large volume air samples for analysis by ultra-low-level gamma spectrometry. A review of the 1985-1995 measurements has highlighted local and distant releases of man-made radionuclides, along with cosmogenic radionuclides which correlate with both solar and seasonal phenomena. Measurements typically involve 2-day air collection of a 70,000 m{sup 3} sample on a 51 cm x 51 cm cellulose filter using a high-capacity pump. Short-lived radon background activity is allowed to decay a few days, and then the filter is configured into a smaller calibrated volume and counted 1-3 days on a 30 percent-efficient HPGe in the Ultra-Low-Level Counting Facility. Representative detection limits for this method are shown in Table 1, and even lower limits are achievable by counting on the low-background 160 percent-efficient HPGe of the Underground Counting Facility.

  12. Effects of Temperature, Humidity and Air Flow on Fungal Growth Rate on Loaded Ventilation Filters.

    PubMed

    Tang, W; Kuehn, T H; Simcik, Matt F

    2015-01-01

    This study compares the fungal growth ratio on loaded ventilation filters under various temperature, relative humidity (RH), and air flow conditions in a controlled laboratory setting. A new full-size commercial building ventilation filter was loaded with malt extract nutrients and conidia of Cladosporium sphaerospermum in an ASHRAE Standard 52.2 filter test facility. Small sections cut from this filter were incubated under the following conditions: constant room temperature and a high RH of 97%; sinusoidal temperature (with an amplitude of 10°C, an average of 23°C, and a period of 24 hr) and a mean RH of 97%; room temperature and step changes between 97% and 75% RH, 97% and 43% RH, and 97% and 11% RH every 12 hr. The biomass on the filter sections was measured using both an elution-culture method and by ergosterol assay immediately after loading and every 2 days up to 10 days after loading. Fungal growth was detected earlier using ergosterol content than with the elution-culture method. A student's t-test indicated that Cladosporium sphaerospermum grew better at the constant room temperature condition than at the sinusoidal temperature condition. By part-time exposure to dry environments, the fungal growth was reduced (75% and 43% RH) or even inhibited (11% RH). Additional loaded filters were installed in the wind tunnel at room temperature and an RH greater than 95% under one of two air flow test conditions: continuous air flow or air flow only 9 hr/day with a flow rate of 0.7 m(3)/s (filter media velocity 0.15 m/s). Swab tests and a tease mount method were used to detect fungal growth on the filters at day 0, 5, and 10. Fungal growth was detected for both test conditions, which indicates that when temperature and relative humidity are optimum, controlling the air flow alone cannot prevent fungal growth. In real applications where nutrients are less sufficient than in this laboratory study, fungal growth rate may be reduced under the same operating conditions

  13. 40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) of this section, or you may develop your own procedure. (g) Correct the measured mass of each sample... subsequently subtracted from the post-test mass of the corresponding sample media (e.g., filters) and collected PM to determine the mass of PM emitted during the test. (h) You may repeat measurements to...

  14. 40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) of this section, or you may develop your own procedure. (g) Correct the measured mass of each sample... subsequently subtracted from the post-test mass of the corresponding sample media (e.g., filters) and collected PM to determine the mass of PM emitted during the test. (h) You may repeat measurements to...

  15. 40 CFR 1065.590 - PM sampling media (e.g., filters) preconditioning and tare weighing.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) of this section, or you may develop your own procedure. (g) Correct the measured mass of each sample... subsequently subtracted from the post-test mass of the corresponding sample media (e.g., filters) and collected PM to determine the mass of PM emitted during the test. (h) You may repeat measurements to...

  16. EVALUATION OF HIGH VOLUME PARTICLE SAMPLING AND SAMPLE HANDLING PROTOCOLS FOR AMBIENT URBAN AIR MUTAGENICITY DETERMINATIONS

    EPA Science Inventory

    An investigation of high volume particle sampling and sample handling procedures was undertaken to evaluate variations of protocols being used by the U.S Environmental Protection Agency. hese protocols are used in urban ambient air studies which collect ambient and source samples...

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

    NASA Astrophysics Data System (ADS)

    Metzger, Robert Lawrence

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

  18. Air Monitoring: New Advances in Sampling and Detection

    PubMed Central

    Watson, Nicola; Davies, Stephen; Wevill, David

    2011-01-01

    As the harmful effects of low-level exposure to hazardous organic air pollutants become more evident, there is constant pressure to improve the detection limits of indoor and ambient air monitoring methods, for example, by collecting larger air volumes and by optimising the sensitivity of the analytical detector. However, at the other end of the scale, rapid industrialisation in the developing world and growing pressure to reclaim derelict industrial land for house building is driving the need for air monitoring methods that can reliably accommodate very-high-concentration samples in potentially aggressive matrices. This paper investigates the potential of a combination of two powerful gas chromatography—based analytical enhancements—sample preconcentration/thermal desorption and time-of-flight mass spectrometry—to improve quantitative and qualitative measurement of very-low-(ppt) level organic chemicals, even in the most complex air samples. It also describes new, practical monitoring options for addressing equally challenging high-concentration industrial samples. PMID:22241966

  19. Highly-Effective Purification of Air on the Fibrous Filtering Nozzles

    NASA Astrophysics Data System (ADS)

    Galtseva, O. V.; Bordunov, S. V.; Torgaev, S. N.

    2016-02-01

    A series of experiments by air purification on fibrous filtering nozzles was made. It is experimentally shown that the fibrous filter can operate in a wide rate range. The degree of trapping of fine aerosols of glass was 99% at a linear rate of 0.01 m/s. the degree of capture decreased to 85% at the increasing of filtration rate up to 0.06 m/s. Dustiness of the air ranged from 3 to 5 g/m3 at the course of the experiment. Hydraulic resistance changed from 5 to 25 mm of water column. The calculated data of resistance and falling of pressure on fibrous filters are given; these data were received on the equations from various sources in comparison with experimentally obtained data. According to the results of series of experiments the amendment of the well-known Fuchsian equation is calculated for calculation of the resistance of fibrous air filter. This amendment considers a form and defects of surface of the fibers received by centrifugal-spinneret method.

  20. High-efficiency particulate air filter test stand and aerosol generator for particle loading studies.

    PubMed

    Arunkumar, R; Hogancamp, Kristina U; Parsons, Michael S; Rogers, Donna M; Norton, Olin P; Nagel, Brian A; Alderman, Steven L; Waggoner, Charles A

    2007-08-01

    This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30 x 30 x 29 cm(3) nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5 to 12 standard m(3)/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150 degrees C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the particle size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA filters at and beyond rated media velocities by consistently providing, into a nominal flow of 7 standard m(3)/min, high mass concentrations (approximately 25 mg/m(3)) of dry aerosol streams having count mean diameters centered near the most penetrating particle size for HEPA filters (120-160 nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test filter. Types of filter performance related studies that can be performed using this test stand system include filter lifetime studies, filtering efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream particle size distributions. PMID

  1. High-efficiency particulate air filter test stand and aerosol generator for particle loading studies

    NASA Astrophysics Data System (ADS)

    Arunkumar, R.; Hogancamp, Kristina U.; Parsons, Michael S.; Rogers, Donna M.; Norton, Olin P.; Nagel, Brian A.; Alderman, Steven L.; Waggoner, Charles A.

    2007-08-01

    This manuscript describes the design, characterization, and operational range of a test stand and high-output aerosol generator developed to evaluate the performance of 30×30×29cm3 nuclear grade high-efficiency particulate air (HEPA) filters under variable, highly controlled conditions. The test stand system is operable at volumetric flow rates ranging from 1.5to12standardm3/min. Relative humidity levels are controllable from 5%-90% and the temperature of the aerosol stream is variable from ambient to 150°C. Test aerosols are produced through spray drying source material solutions that are introduced into a heated stainless steel evaporation chamber through an air-atomizing nozzle. Regulation of the particle size distribution of the aerosol challenge is achieved by varying source solution concentrations and through the use of a postgeneration cyclone. The aerosol generation system is unique in that it facilitates the testing of standard HEPA filters at and beyond rated media velocities by consistently providing, into a nominal flow of 7standardm3/min, high mass concentrations (˜25mg/m3) of dry aerosol streams having count mean diameters centered near the most penetrating particle size for HEPA filters (120-160nm). Aerosol streams that have been generated and characterized include those derived from various concentrations of KCl, NaCl, and sucrose solutions. Additionally, a water insoluble aerosol stream in which the solid component is predominantly iron (III) has been produced. Multiple ports are available on the test stand for making simultaneous aerosol measurements upstream and downstream of the test filter. Types of filter performance related studies that can be performed using this test stand system include filter lifetime studies, filtering efficiency testing, media velocity testing, evaluations under high mass loading and high humidity conditions, and determination of the downstream particle size distributions.

  2. DUS II SOIL GAS SAMPLING AND AIR INJECTION TEST RESULTS

    SciTech Connect

    Noonkester, J.; Jackson, D.; Jones, W.; Hyde, W.; Kohn, J.; Walker, R.

    2012-09-20

    Soil vapor extraction (SVE) and air injection well testing was performed at the Dynamic Underground Stripping (DUS) site located near the M-Area Settling Basin (referred to as DUS II in this report). The objective of this testing was to determine the effectiveness of continued operation of these systems. Steam injection ended on September 19, 2009 and since this time the extraction operations have utilized residual heat that is present in the subsurface. The well testing campaign began on June 5, 2012 and was completed on June 25, 2012. Thirty-two (32) SVE wells were purged for 24 hours or longer using the active soil vapor extraction (ASVE) system at the DUS II site. During each test five or more soil gas samples were collected from each well and analyzed for target volatile organic compounds (VOCs). The DUS II site is divided into four parcels (see Figure 1) and soil gas sample results show the majority of residual VOC contamination remains in Parcel 1 with lesser amounts in the other three parcels. Several VOCs, including tetrachloroethylene (PCE) and trichloroethylene (TCE), were detected. PCE was the major VOC with lesser amounts of TCE. Most soil gas concentrations of PCE ranged from 0 to 60 ppmv with one well (VEW-22A) as high as 200 ppmv. Air sparging (AS) generally involves the injection of air into the aquifer through either vertical or horizontal wells. AS is coupled with SVE systems when contaminant recovery is necessary. While traditional air sparging (AS) is not a primary component of the DUS process, following the cessation of steam injection, eight (8) of the sixty-three (63) steam injection wells were used to inject air. These wells were previously used for hydrous pyrolysis oxidation (HPO) as part of the DUS process. Air sparging is different from the HPO operations in that the air was injected at a higher rate (20 to 50 scfm) versus HPO (1 to 2 scfm). . At the DUS II site the air injection wells were tested to determine if air sparging affected

  3. Multi-wavelength Characterization of Brown and Black Carbon from Filter Samples

    NASA Astrophysics Data System (ADS)

    Johnson, M. M.; Yatavelli, R. L. N.; Chen, L. W. A. A.; Gyawali, M. S.; Arnott, W. P.; Wang, X.; Chakrabarty, R. K.; Moosmüller, H.; Watson, J. G.; Chow, J. C.

    2014-12-01

    Particulate matter (PM) scatters and absorbs solar radiation and thereby affects visibility, the Earth's radiation balance, and properties and lifetimes of clouds. Understanding the radiative forcing (RF) of PM is essential to reducing the uncertainty in total anthropogenic and natural RF. Many instruments that measure light absorption coefficients (βabs [λ], Mm-1) of PM have used light at near-infrared (NIR; e.g., 880 nm) or red (e.g., 633 nm) wavelengths. Measuring βabs over a wider wavelength range, especially including the ultraviolet (UV) and visible, allows for contributions from black carbon (BC), brown carbon (BrC), and mineral dust (MD) to be differentiated. This will help to determine PM RF and its emission sources. In this study, source and ambient samples collected on Teflon-membrane and quartz-fiber filters are used to characterize and develop a multi-wavelength (250 - 1000 nm) filter-based measurement method of PM light absorption. A commercially available UV-visible spectrometer coupled with an integrating sphere is used for quantifying diffuse reflectance and transmittance of filter samples, from which βabs and absorption Ǻngström exponents (AAE) of the PM deposits are determined. The filter-based light absorption measurements of laboratory generated soot and biomass burning aerosol are compared to 3-wavelength photoacoustic absorption measurements to evaluate filter media and loading effects. Calibration factors are developed to account for differences between filter types (Teflon-membrane vs. quartz-fiber), and between filters and in situ photoacoustic absorption values. Application of multi-spectral absorption measurements to existing archived filters, including specific source samples (e.g. diesel and gasoline engines, biomass burning, dust), will also be discussed.

  4. Plutonium Finishing Plant (PFP) Waste Composition and High Efficiency Particulate Air Filter Loading

    SciTech Connect

    ZIMMERMAN, B.D.

    2000-12-11

    This analysis evaluates the effect of the Plutonium Finishing Plant (PFP) waste isotopic composition on Tank Farms Final Safety Analysis Report (FSAR) accidents involving high-efficiency particulate air (HEPA) filter failure in Double-Contained Receiver Tanks (DCRTs). The HEPA Filter Failure--Exposure to High Temperature or Pressure, and Steam Intrusion From Interfacing Systems accidents are considered. The analysis concludes that dose consequences based on the PFP waste isotopic composition are bounded by previous FSAR analyses. This supports USQD TF-00-0768.

  5. Fabrication and characterization of micro-porous cellulose filters for indoor air quality control.

    PubMed

    Yoon, Younghan; Kim, Sungyoun; Ahn, Kwang Ho; Ko, Kwang Baik; Kim, Kwang-Soo

    2016-03-01

    Micro-porous cellulose filters were fabricated from paper mulberry pulp, which has been used for thousands of years with Korean history. 'Han-ji' is the name of a traditional paper used widely in Korea in construction, textile, craftworks and many household items but before now it has not been used for filtration purpose. Seeking for the utilization of this abundant natural material, this study aims to develop a fabrication process for the traditional paper to be used as a filter for dust filtration, and evaluate the performance by lab-scale experiments. To create pores in the paper, cellulose pulp was pretreated using several methods such as TEMPO oxidation and enzyme hydrolysis, or freeze dried with an alcoholic freezing medium, t-butyl alcohol, instead of water. The filters were characterized and their dust removal performance was tested at a lab scale while also monitoring pressure loss. Chemical oxidation and enzymatic pretreatment were helpful in fabricating a homogeneous filter but would not remove fine-dust particles because of its loose, enlarged pores. The best removal efficiency was observed with filters that were not pretreated but in which water had been exchanged with t-butyl alcohol before freeze-drying. The filter attained a dust removal efficiency higher than 99% over the entire experimental period, with a pressure loss of less than 230 Pa, at a 6.67 (cm(3)/s)/cm(2) air-to-cloth ratio. PMID:26370434

  6. Lined sampling vessel including a filter to separate solids from liquids on exit

    DOEpatents

    Shurtliff, Rodney M.; Klingler, Kerry M.; Turner, Terry D.

    2001-01-01

    A filtering apparatus has an open canister with an inlet port. A canister lid is provided which includes an outlet port for the passage of fluids from the canister. Liners are also provided which are shaped to fit the interiors of the canister and the lid, with at least the canister liner preferably being flexible. The sample to be filtered is positioned inside the canister liner, with the lid and lid liner being put in place thereafter. A filter element is located between the sample and the outlet port. Seals are formed between the canister liner and lid liner, and around the outlet port to prevent fluid leakage. A pressure differential is created between the canister and the canister liner so that the fluid in the sample is ejected from the outlet port and the canister liner collapses around the retained solids.

  7. Microorganisms cultured from stratospheric air samples obtained at 41 km.

    PubMed

    Wainwright, M; Wickramasinghe, N C; Narlikar, J V; Rajaratnam, P

    2003-01-21

    Samples of air removed from the stratosphere, at an altitude of 41 km, were previously found to contain viable, but non-cultureable bacteria (cocci and rods). Here, we describe experiments aimed at growing these, together with any other organisms, present in these samples. Two bacteria (Bacillus simplex and Staphylococcus pasteuri) and a single fungus, Engyodontium album (Limber) de Hoog were isolated from the samples. Although the possibility of contamination can never be ruled out when space-derived samples are studied on earth, we are confident that the organisms originated from the stratosphere. Possible mechanisms by which these organisms could have attained such a height are discussed. PMID:12583913

  8. Sampling frequency guidance for ambient air toxics monitoring.

    PubMed

    Bortnick, Steven M; Stetzer, Shannon L

    2002-07-01

    The U.S. Environmental Protection Agency (EPA) is in the process of designing a national network to monitor hazardous air pollutants (HAPs), also known as air toxics. The purposes of the expanded monitoring are to (1) characterize ambient concentrations in representative areas; (2) provide data to support and evaluate dispersion and receptor models; and (3) establish trends and evaluate the effectiveness of HAP emission reduction strategies. Existing air toxics data, in the form of an archive compiled by EPA's Office of Air Quality Planning and Standards (OAQPS), are used in this paper to examine the relationship between estimated annual average (AA) HAP concentrations and their associated variability. The goal is to assess the accuracy, or bias and precision, with which the AA can be estimated as a function of ambient concentration levels and sampling frequency. The results suggest that, for several air toxics, a sampling schedule of 1 in 3 days (1:3) or 1:6 days maybe appropriate for meeting some of the general objectives of the national network, with the more intense sampling rate being recommended for areas expected to exhibit relatively high ambient levels. PMID:12139351

  9. Influence of sampling filter type on the mutagenicity of diesel exhaust particulate extracts

    NASA Astrophysics Data System (ADS)

    Clark, Charles R.; Truex, Timothy J.; Lee, Frank S. C.; Salmeen, Irving T.

    The effects of filter types on the mutagenicity and chemical characteristics of organic extracts of diesel engine particulate exhaust were studied by collecting exhaust particles in a dilution tube simultaneously on three different types of filters: Teflon membrane (Zefluor), Teflon impregnated glass fiber (Pallflex T60A20), and a quartz fiber (Pallflex 2500QAO). The particles were extracted with dichloromethane and subsequently with acetonitrile. The dichloromethane extracts were evaluated in the Salmonella reversion (Ames) assay using strains TA 98, TA 100 and TA 1538 and analyzed by high performance liquid chromatography (HPLC) with fluorescence detection. The filter loadings ranged from 0.3 to 0.7 mg cm -2, typical of loadings in studies of diesel engine particulate exhaust. No major differences in relative concentrations were observed in the polycyclic aromatic hydrocarbon, oxygenated or transition fractions for the three filter types. Furthermore, no differences in the mutagenicity of the samples could be detected.

  10. Bioassay vs. Air Sampling: Practical Guidance and Experience at Hanford

    SciTech Connect

    Carbaugh, Eugene H.; Carlson, Eric W.; Hill, Robin L.

    2004-02-08

    The Hanford Site has implemented a policy to guide in determining whether air sampling data or special fecal bioassay data are more appropriate for determining doses of record for low-level plutonium exposures. The basis for the policy and four years of experience in comparing DAC-hours exposure with bioassay-based dosimetry is discussed.

  11. TETHERED BALLOON SAMPLING SYSTEMS FOR MONITORING AIR POLLUTION

    EPA Science Inventory

    The paper is an overview of recent studies in which balloons, usually tethered, have been used to investigate the structure and air quality of the planetary boundary layer. It also describes a number of lightweight tethered balloon sampling systems, developed to investigate parti...

  12. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF AIR SAMPLES FOR GC/MS ANALYSIS OF PESTICIDES (BCO-L-11.0)

    EPA Science Inventory

    The purpose of this SOP is to describe the procedures for extracting and preparing an air sample consisting of a polyurethane foam (PUF) plug and Teflon-coated glass fiber filter (Pallflex T60A20) for analysis of pesticides. This procedure covers sample preparation for samples t...

  13. Indoor air sampling and mutagenicity studies of emissions from unvented coal combustion

    SciTech Connect

    Mumford, J.L.; Harris, D.B.; Williams, K.; Chuang, J.C.; Cooke, M.

    1987-03-01

    To develop sampling strategies and bioassay protocols for indoor air containing emissions from coal combustion in homes of the rural Xuan Wei County in China, the authors developed a medium-volume sampler to collect the <10-..mu..m particles and semivolatile organics by a filter and an XAD-2 resin, respectively. A high-volume particulate sampler was used for comparison. The coal was burned under conditions that simulated the open-pit combustion that occurs in Xuan Wei. High-volume and medium-volume sampling yielded similar, high particulate concentrations 38-39 mg/m/sup 3/. Fifteen percent of the total extractable organic mass was collected in the XAD-2 resin, and the remaining 85% was retained in the filter. The polycyclic aromatic hydrocarbons found in the XAD were composed of four or fewer rings. In the Ames Salmonella assay, the XAD sample showed low mutagenic activity, and most of the mutagenic activity was found in the filter. The coal combustion emitted both direct- and indirect-acting mutagens, most of which were frameshift mutagens. 12 references, 2 figures, 3 tables.

  14. Determination of selected heavy metals in air samples from the northern part of Jordan.

    PubMed

    Gharaibeh, Ahmad A; El-Rjoob, Abdul-Wahab O; Harb, Mohammed K

    2010-01-01

    In this work, the atmospheric concentrations of selected heavy metals including lead (Pb), iron (Fe), cadmium (Cd), copper (Cu), nickel (Ni), manganese (Mn), and zinc (Zn) were measured for two different sampling sites (urban and rural) in the northern part of Jordan (Irbid city). Samples were collected according to a certain schedule for 1 year. High volume air samplers and glass fiber filters were used to collect the samples. Collected samples were digested using a mixture of analytical grade nitric acid and analytical grade hydrochloric acid, and analyzed to evaluate the levels of heavy metals by atomic absorption spectrophotometry. Six heavy metals (Pb, Fe, Cu, Ni, Mn, and Zn) were measured in all samples; the concentrations of Cd and Co were not detected in Irbid atmosphere by atomic absorption spectroscopy. The results were used to determine the levels of heavy metal pollutants in air, possible sources, and to compare the levels of selected heavy metals in the two studied sites. Aerosols from the rural site have lower concentrations for all the metals compared to those from the urban site. The daily and monthly variations of the elements were investigated. All heavy metals in urban and rural sites reached maximum concentrations in June, July, and August. This is consistent with the increased activities leading to particulate matter emission during the summer period. The enrichment factors with respect to earth crust and correlation coefficients of heavy metals were investigated to predict the possible sources of heavy metals in air. PMID:19083108

  15. Aging assessment of nuclear air-treatment system HEPA filters and adsorbers. Volume 1, Phase 1

    SciTech Connect

    Winegardner, W.K.

    1993-08-01

    A Phase I aging assessment of high-efficiency particulate air (HEPA) filters and activated carbon gas adsorption units (adsorbers) was performed by the Pacific Northwest Laboratory (PNL) as part of the US Nuclear Regulatory Commission`s (NRC) Nuclear Plant Aging Research (NPAR) Program. Information concerning design features; failure experience; aging mechanisms, effects, and stressors; and surveillance and monitoring methods for these key air-treatment system components was compiled. Over 1100 failures, or 12 percent of the filter installations, were reported as part of a Department of Energy (DOE) survey. Investigators from other national laboratories have suggested that aging effects could have contributed to over 80 percent of these failures. Tensile strength tests on aged filter media specimens indicated a decrease in strength. Filter aging mechanisms range from those associated with particle loading to reactions that alter properties of sealants and gaskets. Low radioiodine decontamination factors associated with the Three Mile Island (TMI) accident were attributed to the premature aging of the carbon in the adsorbers. Mechanisms that can lead to impaired adsorber performance include oxidation as well as the loss of potentially available active sites as a result of the adsorption of pollutants. Stressors include heat, moisture, radiation, and airborne particles and contaminants.

  16. Simple Freeze-Drying Procedure for Producing Nanocellulose Aerogel-Containing, High-Performance Air Filters.

    PubMed

    Nemoto, Junji; Saito, Tsuguyuki; Isogai, Akira

    2015-09-01

    Simple freeze-drying of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-oxidized cellulose nanofibril (TOCN) dispersions in water/tert-butyl alcohol (TBA) mixtures was conducted to prepare TOCN aerogels as high-performance air filter components. The dispersibility of the TOCNs in the water/TBA mixtures, and the specific surface area (SSA) of the resulting TOCN aerogels, was investigated as a function of the TBA concentration in the mixtures. The TOCNs were homogeneously dispersed in the water/TBA mixtures at TBA concentrations up to 40% w/w. The SSAs of the TOCN aerogels exceeded 300 m2/g when the TBA concentration in the aqueous mixtures was in the range from 20% to 50% w/w. When a commercially available, high-efficiency particulate air (HEPA) filter was combined with TOCN/water/TBA dispersions prepared using 30% TBA, and the product was freeze-dried, the resulting TOCN aerogel-containing filters showed superior filtration properties. This was because nanoscale, spider-web-like networks of the TOCNs with large SSAs were formed within the filter. PMID:26301859

  17. Spectral Cloud-Filtering of AIRS Data: Non-Polar Ocean

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Gregorich, David; Barron, Diana

    2004-01-01

    The Atmospheric Infrared Sounder (AIRS) is a grating array spectrometer which covers the thermal infrared spectral range between 640 and 1700/cm. In order to retain the maximum radiometric accuracy of the AIRS data, the effects of cloud contamination have to be minimized. We discuss cloud filtering which uses the high spectral resolution of AIRS to identify about 100,000 of 500,000 non-polar ocean spectra per day as relatively "cloud-free". Based on the comparison of surface channels with the NCEP provided global real time sst (rtg.sst), AIRS surface sensitive channels have a cold bias ranging from O.5K during the day to 0.8K during the night. Day and night spatial coherence tests show that the cold bias is due to cloud contamination. During the day the cloud contamination is due to a 2-3% broken cloud cover at the 1-2 km altitude, characteristic of low stratus clouds. The cloud-contamination effects surface sensitive channels only. Cloud contamination can be reduced to 0.2K by combining the spectral filter with a spatial coherence threshold, but the yield drops to 16,000 spectra per day. AIRS was launched in May 2002 on the Earth Observing System (EOS) Aqua satellite. Since September 2002 it has returned 4 million spectra of the globe each day.

  18. Determination of background concentrations for air quality models using spectral analysis and filtering of monitoring data

    NASA Astrophysics Data System (ADS)

    Tchepel, O.; Costa, A. M.; Martins, H.; Ferreira, J.; Monteiro, A.; Miranda, A. I.; Borrego, C.

    2010-01-01

    The use of background concentrations in air pollution modelling is usually a critical issue and a source of errors. The current work proposes an approach for the estimation of background concentrations using air quality measured data decomposed on baseline and short-term components. For this purpose, the spectral density was obtained for air quality monitoring data based on the Fourier series analysis. After, short-term fluctuations associated with the influence of local emissions and dispersion conditions were extracted from the original measurements using an iterative moving-average filter and taking into account the contribution of higher frequencies determined from the spectral analysis. The deterministic component obtained by the filtering is characterised by wider spatial and temporal representativeness than original monitoring data and is assumed to be appropriate for establishing the background values. This methodology was applied to define background concentrations of particulate matter (PM 10) used as input data for a local scale CFD model, and compared with an alternative approach using background concentrations provided by a mesoscale air quality modelling system. The study is focused on a selected domain within the Lisbon urban area (Portugal). The results present a better performance for the microscale model when initialised by decomposed time series and demonstrate the importance of the proposed methodology in reducing the uncertainty of the model predictions. The decomposition of air quality measurements and the removal of short-term fluctuations discussed in the work is a valuable technique to determine representative background concentrations.

  19. Qualitative multiplatform microanalysis of individual heterogeneous atmospheric particles from high-volume air samples.

    PubMed

    Conny, Joseph M; Collins, Sean M; Herzing, Andrew A

    2014-10-01

    High-resolution microscopic analysis of individual atmospheric particles can be difficult, because the filters upon which particles are captured are often not suitable as substrates for microscopic analysis. Described here is a multiplatform approach for microscopically assessing chemical and optical properties of individual heterogeneous urban dust particles captured on fibrous filters during high-volume air sampling. First, particles embedded in fibrous filters are transferred to polished silicon or germanium wafers with electrostatically assisted high-speed centrifugation. Particles are clustered in an array of deposit areas, which allows for easily locating the same particle with different microscopy instruments. Second, particles with light-absorbing and/or light-scattering behavior are identified for further study from bright-field and dark-field light-microscopy modes, respectively. Third, particles identified from light microscopy are compositionally mapped at high definition with field-emission scanning electron microscopy and energy-dispersive X-ray spectroscopy. Fourth, compositionally mapped particles are further analyzed with focused ion-beam (FIB) tomography, whereby a series of thin slices from a particle are imaged, and the resulting image stack is used to construct a three-dimensional model of the particle. Finally, particle chemistry is assessed over two distinct regions of a thin FIB slice of a particle with energy-filtered transmission electron microscopy (TEM) and electron energy-loss spectroscopy associated with scanning transmission electron microscopy (STEM). PMID:25220253

  20. Problems in creation of modern air inlet filters of power gas turbine plants in Russia and methods of their solving

    NASA Astrophysics Data System (ADS)

    Mikhaylov, V. E.; Khomenok, L. A.; Sherapov, V. V.

    2016-08-01

    The main problems in creation and operation of modern air inlet paths of gas turbine plants installed as part of combined-cycle plants in Russia are presented. It is noted that design features of air inlet filters shall be formed at the stage of the technical assignment not only considering the requirements of gas turbine plant manufacturer but also climatic conditions, local atmospheric air dustiness, and a number of other factors. The recommendations on completing of filtration system for air inlet filter of power gas turbine plants depending on the facility location are given, specific defects in design and experience in operation of imported air inlet paths are analyzed, and influence of cycle air preparation quality for gas turbine plant on value of operating expenses and cost of repair works is noted. Air treatment equipment of various manufacturers, influence of aerodynamic characteristics on operation of air inlet filters, features of filtration system operation, anti-icing system, weather canopies, and other elements of air inlet paths are considered. It is shown that nonuniformity of air flow velocity fields in clean air chamber has a negative effect on capacity and aerodynamic resistance of air inlet filter. Besides, the necessity in installation of a sufficient number of differential pressure transmitters allowing controlling state of each treatment stage not being limited to one measurement of total differential pressure in the filtration system is noted in the article. According to the results of the analysis trends and methods for modernization of available equipment for air inlet path, the importance of creation and implementation of new technologies for manufacturing of filtering elements on sites of Russia within the limits of import substitution are given, and measures on reliability improvement and energy efficiency for air inlet filter are considered.

  1. Detecting discontinuities in time series of upper air data: Demonstration of an adaptive filter technique

    SciTech Connect

    Zurbenko, I.; Chen, J.; Rao, S.T.

    1997-11-01

    The issue of global climate change due to increased anthropogenic emissions of greenhouse gases in the atmosphere has gained considerable attention and importance. Climate change studies require the interpretation of weather data collected in numerous locations and/or over the span of several decades. Unfortunately, these data contain biases caused by changes in instruments and data acquisition procedures. It is essential that biases are identified and/or removed before these data can be used confidently in the context of climate change research. The purpose of this paper is to illustrate the use of an adaptive moving average filter and compare it with traditional parametric methods. The advantage of the adaptive filter over traditional parametric methods is that it is less effected by seasonal patterns and trends. The filter has been applied to upper air relative humidity and temperature data. Applied to generated data, the filter has a root mean squared error accuracy of about 600 days when locating changes of 0.1 standard deviations and about 20 days for changes of 0.5 standard deviations. In some circumstances, the accuracy of location estimation can be improved through parametric techniques used in conjunction with the adaptive filter.

  2. Spectral fingerprinting of polycyclic aromatic hydrocarbons in high-volume ambient air samples by constant energy synchronous luminescence spectroscopy

    USGS Publications Warehouse

    Kerkhoff, M.J.; Lee, T.M.; Allen, E.R.; Lundgren, D.A.; Winefordner, J.D.

    1985-01-01

    A high-volume sampler fitted with a glass-fiber filter and backed by polyurethane foam (PUF) was employed to collect airborne particulate and gas-phase polycylic aromatic hydrocarbons (PAHs) in ambient air. Samples were collected from four sources representing a range of environmental conditions: gasoline engine exhaust, diesel engine exhaust, air near a heavily traveled interstate site, and air from a moderately polluted urban site. Spectral fingerprints of the unseparated particulate and gas-phase samples were obtained by constant energy synchronous luminescence spectroscopy (CESLS). Five major PAHs in the gas-phase extracts were characterized and estimated. The compatibility of a high-volume sampling method using polyurethane foam coupled with CESLS detection is explored for use as a screening technique for PAHs in ambient air. ?? 1985 American Chemical Society.

  3. A novel method for air drying aloe leaf slices by covering with filter papers as a shrink-proof layer.

    PubMed

    Kim, S A; Baek, J H; Lee, S J; Choi, S Y; Hur, W; Lee, S Y

    2009-01-01

    To prevent the shrinkage of aloe vera slices during air drying, a method utilizing a shrink-proof layer was developed. The sample was configured of whole leaf aloe slices, where 1 side or both sides were covered with filter papers as shrink-proof layers. After air drying by varying the air temperature and the slice thickness, the drying characteristics, as well as several quality factors of the dried aloe vera leaf slices, were analyzed. In the simulation of the drying curves, the modified Page model showed the best fitness, representing a diffusion-controlled drying mechanism. Nonetheless, there was a trace of a constant-rate drying period in the samples dried by the method. Shrinkage was greatly reduced, and the rehydration ratios increased by approximately 50%. Scanning electron microscopic analysis revealed that the surface structure of original fibrous form was well sustained. FT-IR characteristics showed that the dried samples could sustain aloe polysaccharide acetylation. Furthermore, the functional properties of the dried slices including water holding capacity, swelling, and fat absorption capability were improved, and polysaccharide retention levels increased by 20% to 30%. Therefore, we concluded that application of shrink-proof layers on aloe slices provides a novel way to overcome the shrinkage problems commonly found in air drying, thereby improving their functional properties with less cost. Practical Application: This research article demonstrates a novel air drying method using shrink-proof layers to prevent the shrinkage of aloe slices. We analyzed extensively the characteristics of shrinkage mechanism and physical properties of aloe flesh gels in this drying system. We concluded that this method can be a beneficial means to retain the functional properties of dried aloe, and a potential alternative to freeze drying, which is still costly. PMID:20492108

  4. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - W.L. GORE & ASSOCIATES, INC. L4347 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  5. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - BASF CORPORATION AX/BA-14/9-SAXP FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  6. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT - BAGHOUSE FILTRATION PRODUCTS - ALBANY INTERNATIONAL CORP. INDUSTRIAL PROCESS TECHNOLOGIES PRIMATEX PLUS I FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) pilot of the Environmental Technology Verification (ETV) Program. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of th...

  7. Study of loading/air back-pulse cleaning cycles on the performance of ceramic membrane filters

    SciTech Connect

    Waggoner, Charles; Alderman, Steven; Parsons, Michael; Hogoncamp, Kristina; Alderman, Steven

    2007-07-01

    Available in abstract form only. Full text of publication follows: The most commonly identified threats to conventional glass fiber HEPA filter performance are moisture and rapid blinding of filters by smoke. Regenerable filter media composed of ceramics or sintered metal can be utilized as pre-filters to protect the more vulnerable glass fiber HEPA filters in the event of upset conditions. Additionally, used in a pre-filtering application, the use of these regenerable filters can potentially extend the lifetime of conventional units. A series of tests have been conducted using CeraMem ceramic membrane filters in an effort to evaluate their performance after repeated loading and air back pulse cleaning. This was done in an effort to access filter performance after repeated loading/cleaning cycles. The filters were loaded using a solid potassium chloride aerosol challenge. The filters were evaluated for pressure drop and filtering efficiency changes from one cleaning cycle to the next. Additionally, the particle size distribution of the aerosol penetrating the filters was measured. (authors)

  8. Air Filter Devices Including Nonwoven Meshes of Electrospun Recombinant Spider Silk Proteins

    PubMed Central

    Lang, Gregor; Jokisch, Stephan; Scheibel, Thomas

    2013-01-01

    Based on the natural sequence of Araneus diadematus Fibroin 4 (ADF4), the recombinant spider silk protein eADF4(C16) has been engineered. This highly repetitive protein has a molecular weight of 48kDa and is soluble in different solvents (hexafluoroisopropanol (HFIP), formic acid and aqueous buffers). eADF4(C16) provides a high potential for various technical applications when processed into morphologies such as films, capsules, particles, hydrogels, coatings, fibers and nonwoven meshes. Due to their chemical stability and controlled morphology, the latter can be used to improve filter materials. In this protocol, we present a procedure to enhance the efficiency of different air filter devices, by deposition of nonwoven meshes of electrospun recombinant spider silk proteins. Electrospinning of eADF4(C16) dissolved in HFIP results in smooth fibers. Variation of the protein concentration (5-25% w/v) results in different fiber diameters (80-1,100 nm) and thus pore sizes of the nonwoven mesh. Post-treatment of eADF4(C16) electrospun from HFIP is necessary since the protein displays a predominantly α-helical secondary structure in freshly spun fibers, and therefore the fibers are water soluble. Subsequent treatment with ethanol vapor induces formation of water resistant, stable β-sheet structures, preserving the morphology of the silk fibers and meshes. Secondary structure analysis was performed using Fourier transform infrared spectroscopy (FTIR) and subsequent Fourier self-deconvolution (FSD). The primary goal was to improve the filter efficiency of existing filter substrates by adding silk nonwoven layers on top. To evaluate the influence of electrospinning duration and thus nonwoven layer thickness on the filter efficiency, we performed air permeability tests in combination with particle deposition measurements. The experiments were carried out according to standard protocols. PMID:23685883

  9. Detection of signals by the digital integrate-and-dump filter with offset sampling

    NASA Technical Reports Server (NTRS)

    Sadr, R.; Hurd, W. J.

    1987-01-01

    The Integrate and Dump Filter (IDF) is used as a matched filter for the detection of signals in additive white Gaussian noise. The performance of the digital integrate and dump filter is evaluated. The case considered is when symbol times are known and the sampling clock is free running at a constant rate, i.e., the sampling clock is not phase locked to the symbol clock. Degradations in the output signal to noise ratio of the digital implementation due to sampling rate, sampling offset, and finite bandwidth, resulting from the anti-aliasing low pass prefilter, are computed and compared with those of the analog counterpart. It is shown that the digital IDF performs within 0.6 dB of the ideal analog IDF whenever the prefilter bandwidth exceeds four times the symbol rate and when sampling is performed at the Nyquist rate. The loss can be reduced to 0.3 dB by doubling the sampling rate, where 0.2 dB loss results from finite bandwidth and 0.1 dB results from the digital IDF.

  10. Sampling artifacts in active air sampling of semivolatile organic contaminants: Comparing theoretical and measured artifacts and evaluating implications for monitoring networks.

    PubMed

    Melymuk, Lisa; Bohlin-Nizzetto, Pernilla; Prokeš, Roman; Kukučka, Petr; Klánová, Jana

    2016-10-01

    The effects of sampling artifacts are often not fully considered in the design of air monitoring with active air samplers. Semivolatile organic contaminants (SVOCs) are particularly vulnerable to a range of sampling artifacts because of their wide range of gas-particle partitioning and degradation rates, and these can lead to erroneous measurements of air concentrations and a lack of comparability between sites with different environmental and sampling conditions. This study used specially adapted filter-sorbent sampling trains in three types of active air samplers to investigate breakthrough of SVOCs, and the possibility of other sampling artifacts. Breakthrough volumes were experimentally determined for a range of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs) in sampling volumes from 300 to 10,000 m(3), and sampling durations of 1-7 days. In parallel, breakthrough was estimated based on theoretical sorbent-vapor pressure relationships. The comparison of measured and theoretical determinations of breakthrough demonstrated good agreement between experimental and estimated breakthrough volumes, and showed that theoretical breakthrough estimates should be used when developing air monitoring protocols. Significant breakthrough in active air samplers occurred for compounds with vapor pressure >0.5 Pa at volumes <700 m(3). Sample volumes between 700 and 10,000 m(3) may lead to breakthrough for compounds with vapor pressures between 0.005 and 0.5 Pa. Breakthrough is largely driven by sample volume and compound volatility (therefore indirectly by temperature) and is independent of sampler type. The presence of significant breakthrough at "typical" sampling conditions is relevant for air monitoring networks, and may lead to under-reporting of more volatile SVOCs. PMID:26743995

  11. Revisiting Atmospheric Lead in NYC - Comparison of Archived Air Filters to Urban Park Sediments and Soils

    NASA Astrophysics Data System (ADS)

    Chillrud, S. N.; Ross, J. M.; Yan, B.; Bopp, R.

    2015-12-01

    Urban lake sediments have the potential to be used for reconstructing history of aerosols, providing data before the start of urban air quality monitoring. In a previous study, the similarity between radionuclide and excess Pb inventories (57 g/m^2) in Central Park Lake (CPL) sediments and those same parameters in Central Park soils (CPS) was interpreted to indicate that urban lake sediment cores from CPL represent deposition of atmospheric aerosols over the history of the park, which was constructed in the 1860s. Furthermore, metal ratios and metal chronologies indicated that incineration was the major source of Pb to the NYC atmosphere over the 20th century. In this report, we compare the lake chronologies for metals to a set of archived air filters collected by the Department of Energy's Environmental Measurement Lab (EML). These weekly filters of total suspended particulates (TSP) were collected by a high volume sampler located in lower Manhattan for radionuclides as part of the program focused on documenting radioactive fallout from nuclear weapons testing. Metal concentrations measured in subsamples of the EML filters collected between the 1970s to 1990s showed Pb decreasing more slowly than the records of Pb added to gasoline. Metal ratios in the filters were similar to the ratios measured in CPL sediments; the Pb to Sn ratios were roughly 20:1 and the Pb to Zn ratios were in close to 1. The similarity of the ratios provides additional solid support that the CP Lake sediment cores reflect atmospheric inputs. The enrichment of Pb in the large aerosol particle fraction (TSP), relative to fine PM2.5 fraction, demonstrates that the resuspended NYC soils and their historical contaminant burden, are the primary, current source of Pb to NYC air.

  12. Application of wavelet filtering and Barker-coded pulse compression hybrid method to air-coupled ultrasonic testing

    NASA Astrophysics Data System (ADS)

    Zhou, Zhenggan; Ma, Baoquan; Jiang, Jingtao; Yu, Guang; Liu, Kui; Zhang, Dongmei; Liu, Weiping

    2014-10-01

    Air-coupled ultrasonic testing (ACUT) technique has been viewed as a viable solution in defect detection of advanced composites used in aerospace and aviation industries. However, the giant mismatch of acoustic impedance in air-solid interface makes the transmission efficiency of ultrasound low, and leads to poor signal-to-noise (SNR) ratio of received signal. The utilisation of signal-processing techniques in non-destructive testing is highly appreciated. This paper presents a wavelet filtering and phase-coded pulse compression hybrid method to improve the SNR and output power of received signal. The wavelet transform is utilised to filter insignificant components from noisy ultrasonic signal, and pulse compression process is used to improve the power of correlated signal based on cross-correction algorithm. For the purpose of reasonable parameter selection, different families of wavelets (Daubechies, Symlet and Coiflet) and decomposition level in discrete wavelet transform are analysed, different Barker codes (5-13 bits) are also analysed to acquire higher main-to-side lobe ratio. The performance of the hybrid method was verified in a honeycomb composite sample. Experimental results demonstrated that the proposed method is very efficient in improving the SNR and signal strength. The applicability of the proposed method seems to be a very promising tool to evaluate the integrity of high ultrasound attenuation composite materials using the ACUT.

  13. Effect of High-Pass Filtering on the Neonatal Auditory Brainstem Response to Air- and Bone-Conducted Clicks.

    ERIC Educational Resources Information Center

    Stuart, Andrew; Yang, Edward Y.

    1994-01-01

    Simultaneous 3- channel recorded auditory brainstem responses (ABR) were obtained from 20 neonates with various high-pass filter settings and low intensity levels. Results support the advocacy of less restrictive high-pass filtering for neonatal and infant ABR screening to air-conducted and bone-conducted clicks. (Author/JDD)

  14. Porous filtering media comparison through wet and dry sampling of fixed bed gasification products

    NASA Astrophysics Data System (ADS)

    Allesina, G.; Pedrazzi, S.; Montermini, L.; Giorgini, L.; Bortolani, G.; Tartarini, P.

    2014-11-01

    The syngas produced by fixed bed gasifiers contains high quantities of particulate and tars. This issue, together with its high temperature, avoids its direct exploitation without a proper cleaning and cooling process. In fact, when the syngas produced by gasification is used in an Internal Combustion engine (IC), the higher the content of tars and particulate, the higher the risk to damage the engine is. If these compounds are not properly removed, the engine may fail to run. A way to avoid engine fails is to intensify the maintenance schedule, but these stops will reduce the system profitability. From a clean syngas does not only follow higher performance of the generator, but also less pollutants in the atmosphere. When is not possible to work on the gasification reactions, the filter plays the most important role in the engine safeguard process. This work is aimed at developing and comparing different porous filters for biomass gasifiers power plants. A drum filter was developed and tested filling it with different filtering media available on the market. As a starting point, the filter was implemented in a Power Pallet 10 kW gasifier produced by the California-based company "ALL Power Labs". The original filter was replaced with different porous biomasses, such as woodchips and corn cobs. Finally, a synthetic zeolites medium was tested and compared with the biological media previously used. The Tar Sampling Protocol (TSP) and a modified "dry" method using the Silica Gel material were applied to evaluate the tars, particulate and water amount in the syngas after the filtration process. Advantages and disadvantages of every filtering media chosen were reported and discussed.

  15. Artifact peroxides produced during cryogenic sampling of ambient air

    NASA Astrophysics Data System (ADS)

    Staffelbach, Thomas; Neftel, Albrecht; Dasgupta, Purnendu K.

    Peroxides were found to be produced as artifacts during cryogenic sampling with Horibe traps. Cryogenic trap sampling was compared to collection with a wet effluent diffusion denuder and a Nafion membrane diffusion denuder. Hydrogen peroxide and hydroxymethyl hydroperoxide measured in the cryogenic trap samples were significantly higher. In comparison, no evidence of artifact methyl hydroperoxide production was found. The amount of artifact H2O2 and HMHP produced increased with decreasing trap temperature. Spiking ambient air with ethene or isoprene showed that these hydrocarbons, in the presence of ozone, can be responsible for the artifact production of peroxides. Our results clearly suggest that the peroxide data obtained by cryogenic sampling and reported in the literature should be interpreted with caution.

  16. Improvement on Diversity Gain with Filter Bandwidth Enlargement in Fractional Sampling OFDM Receiver

    NASA Astrophysics Data System (ADS)

    Shinkai, Toshiya; Nishimura, Haruki; Sanada, Yukitoshi

    A diversity scheme with Fractional Sampling (FS) in an OFDM receiver has been investigated recently. Through FS, it is possible to separate multipath components and obtain diversity gain in OFDM systems. Enlargement of the bandwidth of the total frequency response between transmit and receive baseband filters allows the FS scheme to achieve path diversity. However, the transmit filter has to be designed according to the spectrum mask of the wireless standards such as IEEE802.11a/g to avoid interference to the other communication systems and the frequency response of the composite channel including the transmit and receive filters has often been set to minimal bandwidth to eliminate adjacent channel signals. In order to achieve the maximum signal-to-noise ratio (SNR), the same filter is commonly used in the transmitter and the receiver. In this paper, the trade-off among the SNR deterioration, adjacent channel interference, and the diversity gain due to the enlargement of the bandwidth of the receive filter is investigated. Numerical results from computer simulations indicate that the BER performance with wider bandwidth in the receiver shows better performance than that with the minimal bandwidth for maximizing the SNR in certain conditions.

  17. Organic toxicants in air and precipitation samples from the Lake Michigan area

    SciTech Connect

    Harlin, K.S.; Sweet, C.W.; Gatz, D.F.

    1995-12-31

    Measurements of PCBs, organochlorine insecticides, PAHs, and atrazine were made in air and precipitation samples collected at regionally-representative locations near Lake Michigan from 1992-1995. The purpose of these measurements was to provide information needed to estimate the atmospheric deposition of organic toxicants to Lake Michigan. Twenty-four hour samples of airborne particles and vapor were collected at 12-day intervals on quartz fiber filters and XAD-2 resin vapor traps using modified high volume sampleers. Twenty-eight day precipitation samples were collected using wet-only samplers with stainless steel sampling surfaces and heated enclosure containing an XAD-2 resin adsorption column. Samples were Soxhlet extracted for 24 hours with hexane:acetone (1:1), and concentrated by rotary evaporation. Interferences were removed and the samples separated into analyte groups by silica gel chromatography. Four fractions were collected for GC-ECD and GC-Ion Trap MS analyses. Ten pesticides, 101 PCB congeners, 18 PAHs, and atrazine were measured in all samples. Quality assurance was maintained by including field duplicate samples, field blanks, alboratory matrix spikes, laboratory matrix blanks, and laboratory surrogate spikes in the sampling/analytical protocols. Preliminary results from urban and remote sites show geographical variations in the concentrations of some toxicants due to contributions from local sources. For all sites the total PCB levels are higher in the vapor phase than the particulate phase and show strong seasonal variations. Seasonal variations were also observed for several pesticides.

  18. Simultaneous Filtered and Unfiltered Light Scattering Measurements in Laser Generated Air Sparks

    NASA Astrophysics Data System (ADS)

    Limbach, Christopher; Miles, Richard

    2013-09-01

    Elastic laser light scattering may be used to measure the thermofluidic properties of gases and plasmas, including but not limited to density, temperature and velocity. Most of this information is contained within the spectra of the scattered radiation. This may be measured directly through dispersion or indirectly, by passing the light through an atomic or molecular vapor filter with known absorption features. In this work, filtered and unfiltered laser light scattering is used to diagnose air sparks generated by a 1064 nm Q-switched laser. The probe laser consists of a second Q-switched Nd:YAG laser frequency doubled to 532 nm. Simultaneous unfiltered and filtered images of the scattering are captured by a Princeton Instruments ICCD camera by using a 50 mm diameter concave re-imaging mirror. The filter consists of a well-characterized molecular Iodine cell. In the shock wave formed by the laser spark, spatially resolved measurements of density, temperature and radial velocity are extracted and compared with theory and models. Measurements in the spark core probe the ion feature of the electron Thomson scattering, from which ne and T can be extracted with the assumption Te =Ti . Partial funding was provided by General Electric Global Research Center: Niskayuna, New York. The first author is also supported by a National Defense Science and Engineering Graduate Fellowship.

  19. Fixation filter, device for the rapid in situ preservation of particulate samples

    NASA Astrophysics Data System (ADS)

    Taylor, C. D.; Edgcomb, V. P.; Doherty, K. W.; Engstrom, I.; Shanahan, T.; Pachiadaki, M. G.; Molyneaux, S. J.; Honjo, S.

    2015-02-01

    Niskin bottle rosettes have for years been the workhorse technology for collection of water samples used in biological and chemical oceanography. Studies of marine microbiology and biogeochemical cycling that aim to analyze labile organic molecules including messenger RNA, must take into account factors associated with sampling methodology that obscure an accurate picture of in situ activities/processes. With Niskin sampling, the large and often variable times between sample collection and preservation on deck of a ship, and the sometimes significant physico-chemical changes (e.g., changes in pressure, light, temperature, redox state, etc.) that water samples and organisms are exposed to, are likely to introduce artifacts. These concerns are likely more significant when working with phototrophs, deep-sea microbes, and/or organisms inhabiting low-oxygen or anoxic environments. We report here the development of a new technology for the in situ collection and chemical preservation of particulate microbial samples for a variety of downstream analyses depending on preservative choice by the user. The Fixation Filter Unit, version 3 (FF3) permits filtration of water sample through 47 mm diameter filters of the user's choice and upon completion of filtration, chemically preserves the retained sample within 10's of seconds. The stand-alone devices can be adapted to hydrocasting or mooring-based platforms.

  20. Evaluation of official air sampling methodologies in Ukraine

    SciTech Connect

    Nakonechniy, J.J.; Wadden, R.A.; Scheff, P.A.; Suero, M.

    1997-12-31

    In conjunction with an environmental epidemiology study of the health of Ukrainian children, a significant amount of air pollution measurement data was gathered from government agencies. The areas of interest were the industrial city of Dneprodzherzhinsk; and the Dniprovsky region of Kyiv. The data were for 1993 and, for some of the monitoring stations, 1994. The pollutants reported included dust (approximately equivalent to TSP, total suspended particulate matter), SO{sub 2}, CO, NO{sub 2}, NO, H{sub 2}S, phenol, HCl, NH{sub 3}, formaldehyde, BaP, and lead. The ultimate goal was to evaluate whether existing historical data are appropriate for developing measures of human exposure. In order to evaluate the data it was necessary to understand the sampling and analytical methodologies which were used. Small sample volumes coupled with dated analytical procedures resulted in very poor precision and detection limits for most of the measured pollutants. The measurement of particulate matter is a good example of the limits imposed by the sampling methodology. The short sample time (20 min), small sample volume (150 lpm), and limited analytical balances (0.5 mg resolution) result in a minimum lower limit of detection of 0.25 mg/m{sup 3}. For example at Kyiv Station 3 in 1993, only one of 545 measurements exceeded 0.2 mg/m{sup 3}. This minimum detectable quantity is over three times the former US annual TSP standard. In addition, even when operated on a 24-hour basis in the US, it has been shown that the sampling method only collected approximately 34% of that collected by a co-located hi-vol sampler. Consequently, official air pollution data for suspended dust are likely to severely under-represent actual ambient concentrations. Data for other pollutants are presented and sampling and analytical methods are similarly compared with Western methods in common use.

  1. Sampling reconstruction of N-dimensional bandlimited images after multilinear filtering in fractional Fourier domain

    NASA Astrophysics Data System (ADS)

    Wei, Deyun; Li, Yuanmin

    2013-05-01

    This paper addresses the problem of multidimensional signal reconstruction from generalized samples in fractional Fourier domain including the deterministic case and the stochastic case. The generalized sampling expansion is investigated for the case where the fractional bandlimited input depends on N real variable, i.e., f(t)=f(t1,⋯,tN) and is used as a common input to a parallel bank of m independent N dimensional linear fractional Fourier filters Hα,k(u), k=1,⋯,m. For the deterministic input, the input is assumed to have its N dimensional fractional Fourier transform bandlimited to the frequency rang |ui|≤Ωi, for i=1,⋯,N. If m, the number of fractional Fourier filters, is written as a product of positive integers in the form m=m1m2⋯mN, and if the fractional bandlimited input f(t) is processed by fractional Fourier filter Hα,k(u)resulting m outputs gk(t), then f(t) can be reconstructed in terms of the samples gk(nT), each output being sampled at the identical rates of Ω1 csc α/m1π, Ω2 csc α/m2π,⋯, ΩN csc α/mNπ samples/second in t1,⋯,tN respectively. This contrasts with the rates of Ω1 csc α/π, Ω2 csc α/π,⋯, ΩN csc α/π in t1,⋯,tN needed for reconstruction of the unfiltered input f(t). Input sampling expansions in terms of samples of the output filters are given for both deterministic and stochastic inputs, the generalized sampling expansion for random input having the same form as for the deterministic case but interpreted in the mean-square sense. Our formulation and results are general and include derivative sampling and periodic nonuniform sampling in the fractional Fourier domain for multidimensional signals as special case. Finally, the potensional application of the multidimensional generalized sampling is presented to show the advantage of the theory. Especially, the application of multidimensional generalized sampling in the context of the image scaling about image super-resolution is

  2. Passive air sampling of gaseous elemental mercury: a critical review

    NASA Astrophysics Data System (ADS)

    McLagan, David S.; Mazur, Maxwell E. E.; Mitchell, Carl P. J.; Wania, Frank

    2016-03-01

    Because gaseous elemental mercury (GEM) is distributed globally through the atmosphere, reliable means of measuring its concentrations in air are important. Passive air samplers (PASs), designed to be cheap, simple to operate, and to work without electricity, could provide an alternative to established active sampling techniques in applications such as (1) long-term monitoring of atmospheric GEM levels in remote regions and in developing countries, (2) atmospheric mercury source identification and characterization through finely resolved spatial mapping, and (3) the recording of personal exposure to GEM. An effective GEM PAS requires a tightly constrained sampling rate, a large and stable uptake capacity, and a sensitive analytical technique. None of the GEM PASs developed to date achieve levels of accuracy and precision sufficient for the reliable determination of background concentrations over extended deployments. This is due to (1) sampling rates that vary due to meteorological factors and manufacturing inconsistencies, and/or (2) an often low, irreproducible and/or unstable uptake capacity of the employed sorbents. While we identify shortcomings of existing GEM PAS, we also reveal potential routes to overcome those difficulties. Activated carbon and nanostructured metal surfaces hold promise as effective sorbents. Sampler designs incorporating diffusive barriers should be able to notably reduce the influence of wind on sampling rates.

  3. Passive air sampling of gaseous elemental mercury: a critical review

    NASA Astrophysics Data System (ADS)

    McLagan, D. S.; Mazur, M. E. E.; Mitchell, C. P. J.; Wania, F.

    2015-12-01

    Because gaseous elemental mercury (GEM) is distributed globally through the atmosphere, reliable means of measuring its concentrations in air are important. Passive air samplers (PASs), designed to be cheap, simple to operate, and to work without electricity, could provide an alternative to established active sampling techniques in applications such as (1) long term monitoring of atmospheric GEM levels in remote regions and in developing countries, (2) atmospheric mercury source identification and characterisation through finely-resolved spatial mapping, and (3) the recording of personal exposure to GEM. An effective GEM PAS requires a tightly constrained sampling rate, a large and stable uptake capacity, and a sensitive analytical technique. None of the GEM PASs developed to date achieves levels of accuracy and precision sufficient for the reliable determination of background concentrations over extended deployments. This is due to (1) sampling rates that vary due to meteorological factors and manufacturing inconsistencies and/or (2) an often low, irreproducible and/or unstable uptake capacity of the employed sorbents. While we identify shortcomings of existing GEM PAS, we also reveal potential routes to overcome those difficulties. Activated carbon and nano-structured metal surfaces hold promise as effective sorbents. Sampler designs incorporating diffusive barriers should be able to notably reduce the influence of wind on sampling rates.

  4. Interlaboratory evaluation of cellulosic acid-soluble internal air sampling capsules for multi-element analysis.

    PubMed

    Andrews, Ronnee N; Feng, H Amy; Ashley, Kevin

    2016-01-01

    An interlaboratory study was carried out to evaluate the use of acid-soluble cellulosic air sampling capsules for their suitability in the measurement of trace elements in workplace atmospheric samples. These capsules are used as inserts to perform closed-face cassette sample collection for occupational exposure monitoring. The interlaboratory study was performed in accordance with NIOSH guidelines that describe statistical procedures for evaluating measurement accuracy of air monitoring methods. The performance evaluation materials used consisted of cellulose acetate capsules melded to mixed-cellulose ester filters that were dosed with multiple elements from commercial standard aqueous solutions. The cellulosic capsules were spiked with the following 33 elements of interest in workplace air monitoring: Ag, Al, As, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, In, K, La, Li, Mg, Mn, Mo, Ni, P, Pb, Sb, Se, Sn, Sr, Te, Ti, Tl, V, W, Y, Zn, Zr. The elemental loading levels were certified by an accredited provider of certified reference materials. Triplicates of media blanks and multielement-spiked capsules at three different elemental loadings were sent to each participating laboratory; the elemental loading levels were not revealed to the laboratories. The volunteer participating laboratories were asked to prepare the samples by acid dissolution and to analyze aliquots of extracted samples by inductively coupled plasma atomic emission spectrometry in accordance with NIOSH methods. It was requested that the study participants report their analytical results in units of μg of each target element per internal capsule sample. For the majority of the elements investigated (30 out of 33), the study accuracy estimates obtained satisfied the NIOSH accuracy criterion (A < 25%). This investigation demonstrates the utility of acid-soluble internal sampling capsules for multielement analysis by atomic spectrometry. PMID:26308974

  5. Airborne Nanoparticle Detection By Sampling On Filters And Laser-Induced Breakdown Spectroscopy Analysis

    NASA Astrophysics Data System (ADS)

    Dewalle, Pascale; Sirven, Jean-Baptiste; Roynette, Audrey; Gensdarmes, François; Golanski, Luana; Motellier, Sylvie

    2011-07-01

    Nowadays, due to their unique physical and chemical properties, engineered nanoparticles are increasingly used in a variety of industrial sectors. However, questions are raised about the safety of workers who produce and handle these particles. Therefore it is necessary to assess the potential exposure by inhalation of these workers. There is thereby a need to develop a suitable instrumentation which can detect selectively the presence of engineered nanoparticles in the ambient atmosphere. In this paper Laser-Induced Breakdown Spectroscopy (LIBS) is used to meet this target. LIBS can be implemented on site since it is a fast and direct technique which requires no sample preparation. The approach consisted in sampling Fe2O3 and TiO2 nanoparticles on a filter, respectively a mixed cellulose ester membrane and a polycarbonate membrane, and to measure the surface concentration of Fe and Ti by LIBS. Then taking into account the sampling parameters (flow, duration, filter surface) we could calculate a detection limit in volume concentration in the atmosphere. With a sampling at 10 L/min on a 10 cm2 filter during 1 min, we obtained detection limits of 56 μg/m3 for Fe and 22 μg/m3 for Ti. These figures, obtained in real time, are significantly below existing workplace exposure recommendations of the EU-OSHA and of the NIOSH. These results are very encouraging and will be completed in a future work on airborne carbon nanotube detection.

  6. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.12)

    EPA Science Inventory

    The method is for extracting an indoor and outdoor air sample consisting of a quartz fiber filter and an XAD-2 cartridge for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass...

  7. Sampling and analysis of terpenes in air. An interlaboratory comparison

    NASA Astrophysics Data System (ADS)

    Larsen, Bo; Bomboi-Mingarro, Teresa; Brancaleoni, Enzo; Calogirou, Aggelos; Cecinato, Angelo; Coeur, Cecile; Chatzinestis, Ioannis; Duane, Matthew; Frattoni, Massimiliano; Fugit, Jean-Luc; Hansen, Ute; Jacob, Veronique; Mimikos, Nikolaos; Hoffmann, Thorsten; Owen, Susan; Perez-Pastor, Rosa; Reichmann, Andreas; Seufert, Gunther; Staudt, Michael; Steinbrecher, Rainer

    An interlaboratory comparison on the sampling and analysis of terpenes in air was held within the framework of the BEMA (Biogenic Emissions in the Mediterranean Area) project in May 1995. Samples were drawn and analysed by 10 European laboratories from a dynamic artificial air generator in which five terpenes were present at low ng ℓ -1 levels and ozone varied between 8 and 125 ppbv. Significant improvements over previous inter-comparison exercises in the quality of results were observed. At the ozone mixing ratio of 8 ppbv a good agreement among laboratories was obtained for all test compounds with mean values close to the target concentration. At higher mixing ratios, ozone reduced terpene recoveries and decreased the precision of the measurements due to ozonolysis during sampling. For β-pinene this effect was negligible but for the more reactive compounds significant losses were observed in some laboratories ( cis-β-ocimene = trans-β-ocimene > linalool > d-limonene). The detrimental effect of ozone was significantly lower for the laboratories which removed ozone prior to sampling by scrubbers. Parallel sampling was carried out with a standardised sampler and each individual laboratory's own device. A good agreement between the two sets of results was obtained, clearly showing that the majority of laboratories used efficient sampling systems. Two different standard solutions were analysed by each laboratory. Only in a few cases did interference in the GC separation cause problems for the quantification of the terpenes (nonanal/linalool). However, making up of standards for the calibration of the analytical equipment (GC-MS or GC-FID) was pointed out as a source of error in some laboratories.

  8. CONVENIENT SAMPLING OF AIR BACTERIA IN OPERATING ROOMS.

    PubMed

    WARNER, P; GLASSCO, A; KROEKER, J

    1964-02-22

    A convenient arrangement for sampling air bacteria in operating rooms with a slit sampler (the Fort Detrick sampler) is described. Its purpose is to contribute as far as possible to the convenience of the surgical staff and thereby to the safety of the patient. It has the advantages of recording minute-to-minute changes in bacterial air count; it is unobtrusive and yet can be continually observed by a technician; it is not noisy and avoids the dangers of explosion and static electricity; it is inexpensive, and parts are easily replaced; and finally it provides a means of keeping permanent photographic records of bacterial counts. Results of a preliminary trial of this method appeared to be satisfactory. PMID:14118695

  9. In-place HEPA (high efficiency, particulate air) filter testing at Hanford: Operating experiences, calibrations, and lessons learned

    SciTech Connect

    Flores, D.S.; Decelis, D.G.

    1989-10-01

    High Efficiency, Particulate Air (HEPA) Filters provide a minimum of 99.97% removal efficiency for particles greater than or equal to .3 microns in diameter. Each HEPA filter installation at Hanford is, at specified intervals, functionally tested for leaks. The test procedure involves a dioctylphthalate (DOP) smoke generator and a calibrated airborne particle detector. The DOP generator produces smoke of a known quantitative particle size distribution upstream of the filter. The airborne particle detector is first placed upstream, and then downstream of the filter to determine percent penetration. The smoke generator is characterized using a calibrated laser spectrometer, and the particle detector is calibrated using a calibrated picoammeter. 2 refs., 4 figs.

  10. High Efficiency Particulate Air (HEPA) Filter Generation, Characterization, and Disposal Experiences at the Oak Ridge National Laboratory

    SciTech Connect

    Coffey, D. E.

    2002-02-28

    High Efficiency Particulate Air filtration is an essential component of the containment and ventilation systems supporting the research and development activities at the Oak Ridge National Laboratory. High Efficiency Particulate Air filters range in size from 7.6cm (3 inch) by 10.2 cm (4 inch) cylindrical shape filters to filter array assemblies up to 2.1 m (7 feet) high by 1.5 m (5 feet) wide. Spent filters are grouped by contaminates trapped in the filter media and become one of the components in the respective waste stream. Waste minimization and pollution prevention efforts are applied for both radiological and non-radiological applications. Radiological applications include laboratory hoods, glove boxes, and hot cells. High Efficiency Particulate Air filters also are generated from intake or pre-filtering applications, decontamination activities, and asbestos abatement applications. The disposal avenues include sanitary/industrial waste, Resource Conservation and Recovery Act and Toxic Substance Control Act, regulated waste, solid low-level waste, contact handled transuranic, and remote handled transuranic waste. This paper discusses characterization and operational experiences associated with the disposal of the spent filters across multiple applications.

  11. Ice nucleation active particles in continental air samples over Mainz, Germany

    NASA Astrophysics Data System (ADS)

    Pummer, Bernhard G.; Pöschl, Ulrich; Fröhlich-Nowoisky, Janine

    2016-04-01

    Aerosol particles are of central importance for atmospheric chemistry and physics, climate and public health. Some of these particles possess ice nucleation activity (INA), which is highly relevant for cloud formation and precipitation. In 2010, air filter samples were collected with a high-volume filter sampler separating fine and coarse particles (aerodynamic cut-off diameter 3 μm) in Mainz, Germany. In this study, the INA of the atmospheric particles deposited on these filters was determined. Therefore,they were extracted with ultrapure water, which was then measured in a droplet freezing assay, as described in Fröhlich-Nowoisky et al. (2015). The determined concentration of ice nucleators (INs) was between 0.3 and 2per m³ at 266 K, and between5 and 75 per m³ at 260 K. The INs were further characterized by different treatments, like heating (308 K, 371 K), filtration (0.1 μm, 300 kDa), and digestion with papain (10 mg/ml). We further investigated, which atmospheric conditions (e.g. weather) and distinguished events (e.g. dust storms, volcanic eruptions, and pollen peaks) influenced the number and nature of these INs. Fröhlich-Nowoisky, J., Hill, T. C. J., Pummer, B. G., Yordanova, P., Franc, G. D., and Pöschl, U.: Ice nucleation activity in the widespread soil fungus Mortierella alpina, Biogeosci., 12, 1057-1071, doi:10.5194/bg-12-1057-2015, 2015.

  12. Integrated measurements of 212Pb and 212Bi in the air by rotating filters.

    PubMed

    Pressyanov, D S

    1995-02-01

    A method for determining time integrated concentrations of 212Pb and 212Bi in the air is proposed. It employs solid state nuclear track detectors covered with an absorber and placed around a rotating filter. Results from experiments carried out in an artificial 220Rn atmosphere have been presented. They reveal that the method works within the range of integrated concentrations for indoor measurements. The experimental error was about 7% for 212Pb and 23% for 212Bi. Possibilities for improving the accuracy have been discussed. PMID:7814259

  13. Relative Humidity and its Effect on Sampling and Analysis of Agricultural Odorants in Air

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Source and ambient air sampling techniques used in agricultural air quality studies are seldom validated for the variability in the air matrix (temperature, dust levels, and relative humidity). In particular, relative humidity (RH) affects both field sampling and analysis of air samples. The objec...

  14. Bioanalysis of uranium, plutonium, and curium on breathing zone air samples by solvent extraction and PERALS spectroscopy

    SciTech Connect

    Metzger, R.L.; Jessop, B.H.; McDowell, B.L.

    1995-12-31

    Breathing zone air samples are commonly used to monitor airborne concentrate of radionuclides in ions the workplace and to assess the efficacy of respiratory protection programs. Radioactive isotopes of actinides have very low allowable airborne concentrations, so knowledge of the airborne activities of these nuclides is crucial. The air samples are typically analyzed for alpha-particle-emitting radionuclides by direct counting of the filters or by conventional separation chemistry and alpha-particle spectrometry. These techniques do not normally provide a sample turnaround that is sufficiently rapid to allow a change in the respiratory protection program, if necessary. In this work we have developed straightforward solvent extraction separation procedures that can rapidly phase transfer isotopes of uranium, plutonium, and americium or curium from a dissolved filter medium to an extractive scintillator for counting on a Photon/Electron-Rejecting Alpha Liquid Scintillation (PERALS{sup {reg_sign}}) Spectrometer. Results can normally be obtained within eight hours from the receipt of the air filter.

  15. Evaluation of the effect of media velocity on filter efficiency and most penetrating particle size of nuclear grade high-efficiency particulate air filters.

    PubMed

    Alderman, Steven L; Parsons, Michael S; Hogancamp, Kristina U; Waggoner, Charles A

    2008-11-01

    High-efficiency particulate air (HEPA) filters are widely used to control particulate matter emissions from processes that involve management or treatment of radioactive materials. Section FC of the American Society of Mechanical Engineers AG-1 Code on Nuclear Air and Gas Treatment currently restricts media velocity to a maximum of 2.5 cm/sec in any application where this standard is invoked. There is some desire to eliminate or increase this media velocity limit. A concern is that increasing media velocity will result in higher emissions of ultrafine particles; thus, it is unlikely that higher media velocities will be allowed without data to demonstrate the effect of media velocity on removal of ultrafine particles. In this study, the performance of nuclear grade HEPA filters, with respect to filter efficiency and most penetrating particle size, was evaluated as a function of media velocity. Deep-pleat nuclear grade HEPA filters (31 cm x 31 cm x 29 cm) were evaluated at media velocities ranging from 2.0 to 4.5 cm/sec using a potassium chloride aerosol challenge having a particle size distribution centered near the HEPA filter most penetrating particle size. Filters were challenged under two distinct mass loading rate regimes through the use of or exclusion of a 3 microm aerodynamic diameter cut point cyclone. Filter efficiency and most penetrating particle size measurements were made throughout the duration of filter testing. Filter efficiency measured at the onset of aerosol challenge was noted to decrease with increasing media velocity, with values ranging from 99.999 to 99.977%. The filter most penetrating particle size recorded at the onset of testing was noted to decrease slightly as media velocity was increased and was typically in the range of 110-130 nm. Although additional testing is needed, these findings indicate that filters operating at media velocities up to 4.5 cm/sec will meet or exceed current filter efficiency requirements. Additionally

  16. The effect of sampling rate and anti-aliasing filters on high-frequency response spectra

    USGS Publications Warehouse

    Boore, David M.; Goulet, Christine

    2013-01-01

    The most commonly used intensity measure in ground-motion prediction equations is the pseudo-absolute response spectral acceleration (PSA), for response periods from 0.01 to 10 s (or frequencies from 0.1 to 100 Hz). PSAs are often derived from recorded ground motions, and these motions are usually filtered to remove high and low frequencies before the PSAs are computed. In this article we are only concerned with the removal of high frequencies. In modern digital recordings, this filtering corresponds at least to an anti-aliasing filter applied before conversion to digital values. Additional high-cut filtering is sometimes applied both to digital and to analog records to reduce high-frequency noise. Potential errors on the short-period (high-frequency) response spectral values are expected if the true ground motion has significant energy at frequencies above that of the anti-aliasing filter. This is especially important for areas where the instrumental sample rate and the associated anti-aliasing filter corner frequency (above which significant energy in the time series is removed) are low relative to the frequencies contained in the true ground motions. A ground-motion simulation study was conducted to investigate these effects and to develop guidance for defining the usable bandwidth for high-frequency PSA. The primary conclusion is that if the ratio of the maximum Fourier acceleration spectrum (FAS) to the FAS at a frequency fsaa corresponding to the start of the anti-aliasing filter is more than about 10, then PSA for frequencies above fsaa should be little affected by the recording process, because the ground-motion frequencies that control the response spectra will be less than fsaa . A second topic of this article concerns the resampling of the digital acceleration time series to a higher sample rate often used in the computation of short-period PSA. We confirm previous findings that sinc-function interpolation is preferred to the standard practice of using

  17. Simultaneous trace determination of nine organic UV-absorbing compounds (UV filters) in environmental samples.

    PubMed

    Zenker, Armin; Schmutz, Hansruedi; Fent, Karl

    2008-08-15

    A new sensitive method has been successfully developed and validated for the simultaneous determination and quantification of nine estrogenic UV filters (benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-4, 4,4-dihydroxybenzophenone, ethyl-4-aminobenzoate, 2-ethyl-hexyl-4-trimethoxycinnamate, 3-(4-methylbenzylidene)-camphor, 3-benzylidene-camphor) in different environmental matrices. After optimisation of extraction conditions for the best recovery of polar to lipophilic compounds from fish tissue and a subsequent lipid clean-up in HPLC, fish extraction recoveries exceeded 72% for all nine UV filters. Identification and quantification of compounds was performed for lipophilic UV filters with gas chromatography-electroionisation-mass spectrometry and for polar and mid-polar compounds with liquid chromatography coupled to electrospray ionisation mass spectrometry. Instrumental detection limits (IDL) varied between 5 and 260 pg injected and method detection limits (MDL) were in the low ng/g lipids range for all test compounds. The described analytical methods are shown to be useful to screen for estrogenic UV filters in environmental samples such as fish and polar organic chemical integrative samplers. PMID:18632108

  18. 13c Measurements On Air of Small Ice Samples

    NASA Astrophysics Data System (ADS)

    Eyer, M.; Leuenberger, M.

    We have developed a new method for 13C analysis for very small air amounts of less than 0.5 cc STP, corresponding to less than 10 gram of ice. It is based on the needle-crasher technique, which we routinely use for CO2 concentration measurements by infrared laser absorption. The extracted air is slowly expanded into a large volume through a water trap held at ­100°C. This sampled air is then carried by a high helium flux through a modified Precon system of Thermo-Finnigan to separate CO2 from the air and to inject the pure CO2 gas in a low helium stream via an open split device to a Delta Plus XL mass spectrometer. The overall precision based on replicates of standard air is significantly better than 0.1 for a single analysis and is further improved by a triplicate measurement of the same sample through a specially designed gas splitter. We have used this new method for investigations on polar ice cores. The 13C measurements are important for climate reconstructions, e.g. to reconstruct the evolution and its variability in the terrestrial and oceanic carbon sinks and to identify natural variations in the marine carbon cycle. During the industrialization atmospheric 13C decreased by about -2, mainly due to the anthropogenic release of biogenic CO2 by fossil fuel burning. Reconstructions of carbon and oxygen cycles of Joos at al. [1999] using a double deconvolution method show that between 1930 and 1950 the net terrestrial release is changing to a net terrestrial uptake of CO2. A highly resolved 13C dataset of this time window would replenish the documentation of this behaviour. Further, it would be interesting to compare such data with O2/N2 measurements, known as an other partitioning tool for carbon sources and sinks. At the EGS 2002 we will present a highly resolved 13C record from Antarctic ice covering this time period.

  19. Ozone measurement system for NASA global air sampling program

    NASA Technical Reports Server (NTRS)

    Tiefermann, M. W.

    1979-01-01

    The ozone measurement system used in the NASA Global Air Sampling Program is described. The system uses a commercially available ozone concentration monitor that was modified and repackaged so as to operate unattended in an aircraft environment. The modifications required for aircraft use are described along with the calibration techniques, the measurement of ozone loss in the sample lines, and the operating procedures that were developed for use in the program. Based on calibrations with JPL's 5-meter ultraviolet photometer, all previously published GASP ozone data are biased high by 9 percent. A system error analysis showed that the total system measurement random error is from 3 to 8 percent of reading (depending on the pump diaphragm material) or 3 ppbv, whichever are greater.

  20. Air quality benefits of universal particle filter and NOx controls on diesel trucks

    NASA Astrophysics Data System (ADS)

    Tao, L.; Mcdonald, B. C.; Harley, R.

    2015-12-01

    Heavy-duty diesel trucks are a major source of black carbon/particulate matter and nitrogen oxide emissions on urban and regional scales. These emissions are relevant to both air quality and climate change. Since 2010 in the US, new engines are required to be equipped with emission control systems that greatly reduce both PM and NOx emissions, by ~98% relative to 1988 levels. To reduce emissions from the legacy fleet of older trucks that still remain on the road, regulations have been adopted in Califonia to accelerate the replacement of older trucks and thereby reduce associated emissions of PM and NOx. Use of diesel particle filters will be widespread by 2016, and universal use of catalytic converters for NOx control is required by 2023. We assess the air quality consequences of this clean-up effort in Southern California, using the Community Multiscale Air Quality model (CMAQ), and comparing three scenarios: historical (2005), present day (2016), and future year (2023). Emissions from the motor vehicle sector are mapped at high spatial resolution based on traffic count and fuel sales data. NOx emissions from diesel engines in 2023 are expected to decrease by ~80% compared to 2005, while the fraction of NOx emitted as NO2 is expected to increase from 5 to 18%. Air quality model simulations will be analyzed to quantify changes in NO2, black carbon, particulate matter, and ozone, both basin-wide and near hot spots such as ports and major highways.

  1. Define and Quantify the Physics of Air Flow, Pressure Drop and Aerosol Collection in Nuclear Grade HEPA Filters

    SciTech Connect

    Moore, Murray E.

    2015-02-23

    Objective: Develop a set of peer-review and verified analytical methods to adjust HEPA filter performance to different flow rates, temperatures and altitudes. Experimental testing will measure HEPA filter flow rate, pressure drop and efficiency to verify the analytical approach. Nuclear facilities utilize HEPA (High Efficiency Particulate Air) filters to purify air flow for workspace ventilation. However, the ASME AG-1 technical standard (Code on Nuclear Air and Gas Treatment) does not adequately describe air flow measurement units for HEPA filter systems. Specifically, the AG-1 standard does not differentiate between volumetric air flow in ACFM (actual cubic feet per minute)compared to mass flow measured in SCFM (standard cubic feet per minute). More importantly, the AG-1 standard has an overall deficiency for using HEPA filter devices at different air flow rates, temperatures, and altitudes. Technical Approach: The collection efficiency and pressure drops of 18 different HEPA filters will be measured over a range of flow rates, temperatures and altitudes. The experimental results will be compared to analytical scoping calculations. Three manufacturers have allocated six HEPA filters each for this effort. The 18 filters will be tested at two different flow rates, two different temperatures and two different altitudes. The 36 total tests will be conducted at two different facilities: the ATI Test facilities (Baltimore MD) and the Los Alamos National Laboratory (Los Alamos NM). The Radiation Protection RP-SVS group at Los Alamos has an aerosol wind tunnel that was originally designed to evaluate small air samplers. In 2010, modifications were started to convert the wind tunnel for HEPA filter testing. (Extensive changes were necessary for the required aerosol generators, HEPA test fixtures, temperature control devices and measurement capabilities.) To this date, none of these modification activities have been funded through a specific DOE or NNSA program. This is

  2. Loss of PM2.5 nitrate from filter samples in central California.

    PubMed

    Chow, Judith C; Watson, John G; Lowenthal, Douglas H; Magliano, Karen L

    2005-08-01

    Evaporative loss of particulate matter (with aerodynamic diameter < 2.5 microm, [PM2.5]) ammonium nitrate from quartz-fiber filters during aerosol sampling was evaluated from December 3, 1999, through February 3, 2001, at two urban (Fresno and Bakersfield) and three nonurban (Bethel Island, Sierra Nevada Foothills, and Angiola) sites in central California. Compared with total particulate nitrate, evaporative nitrate losses ranged from < 10% during cold months to > 80% during warm months. In agreement with theory, evaporative loss from quartz-fiber filters in nitric acid denuded samplers is controlled by the ambient nitric acid-to-particulate nitrate ratio, which is determined mainly by ambient temperature. Accurate estimation of nitrate volatilization requires a detailed thermodynamic model and comprehensive chemical measurements. For the 14-month average of PM2.5 acquired on Teflon-membrane filters, measured PM2.5 mass was 8-16% lower than actual PM2.5 mass owing to nitrate volatilization. For 24-hr samples, measured PM2.5 was as much as 32-44% lower than actual PM2.5 at three California Central Valley locations. PMID:16187585

  3. Extended-life nuclear air cleaning filters via dynamic exclusion prefilters

    SciTech Connect

    Wright, S.R.; Crouch, H.S.; Bond, J.H.

    1997-08-01

    The primary objective of this investigation was to ascertain if a dynamic, self-cleaning particulate exclusion precleaner, designed for relatively large dust removal (2 to 100+ {mu}m diameter particles) from helicopter turbine inlets, could be extended to submicron filtration. The improved device could be used as a prefilter for HEPA filtration systems, significantly increasing service life. In nuclear air cleaning, its use would reduce the amount of nuclear particulate matter that would otherwise be entrapped in the HEPA filter cartridge/panel, causing fouling and increased back pressure, as well as requiring subsequent disposal of the contaminated media at considerable expense. A unique (patent-pending) mechanical separation device has recently been developed to extract particulate matter from fluid process streams based on a proprietary concept called Boundary Layer Momentum Transfer (BLMT). The device creates multiple boundary layers that actively exclude particles from entering the perimeter of the device, while allowing air to traverse the boundaries relatively unimpeded. A modified two-dimensional (2-D) computerized flow simulation model was used to assist in the prototype design. Empirical results are presented from particle breakthrough and AP experiments obtained from a reduced-scale prototype filter. Particles larger than 0.23 {mu}m were actively excluded by the prototype, but at a higher pressure drop than anticipated. Experimental data collected indicates that the filter housing and the inlet flow configuration may contribute significantly to improvements in device particle separation capabilities. Furthermore, preliminary experiments have shown that other downstream pressure drop considerations (besides those just across the spinning filtration disks) must be included to accurately portray the AP across the device. Further detailed quantitative investigations on a larger scale (1,000 CFM) prototype are warranted. 3 refs., 5 figs., 2 tabs.

  4. Evaluation of a sampling and analysis method for determination of polyhalogenated dibenzo-p-dioxins and dibenzofurans in ambient air

    SciTech Connect

    Harless, R.L.; Lewis, R.G.; McDaniel, D.D.; Gibson, J.F.; Dupuy, A.E.

    1992-01-01

    General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenz-p-dioxins and dibenzofurans (PBDDs/PBDFs) and bromo/chloro dibenzo-p-dioxins and dibenzofurans (BCDDs/BCDFs) in ambient air. Dilute solutions of these compounds and (13)C-1,2,3,4-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hrs to sample 350-400 cubic meter ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with (13)C-12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to an acid/base clean-up procedure followed by clean-up on microcolumns of silica gel, alumina, and carbon and then analyzed by HRGC-HRMS. Results derived from the study indicated the PS-1 ambient air samplers and the analytical procedures were very efficient and that pg/cubic meter and sub-pg/cubic meter levels of total PCDDs/PCDFs, PBDDs/PBDFs, BCDDs/BCDFs, and 2,3,7,8-substituted congeners could be accurately measured.

  5. Method validation program for the long duration sampling of PCDDs/PCDFs in ambient air

    SciTech Connect

    Maisel, B.E.; Hunt, G.T.; Hoyt, M.P.; Rowe, N.; Scarfo, L.

    1994-12-31

    A method validation program was completed to assess the technical viability of extended, long duration sampling periods (15- and 30-day) for the collection of PCDDs/PCDFs in ambient air in lieu of the 48-hour sampling periods typically employed. This long duration approach, if successful, would provide measurements data more representative of average ambient PCDDs/PCDFs levels on an annual basis, and hence provide enhanced support of the 1.0 pg/m{sup 3} annual ambient standard for PCDDs/PCDFs (expressed at 1987 EPA toxic equivalents) required by Connecticut regulation. The method validation program utilized nine collocated PUF samplers which were operated for 15-day and 30-day periods during each of two seasonal monitoring campaigns (winter and summer). Samples were analyzed using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) based on EPA Method 8290. Each PUF cartridge consisted of two foam halves; the top half PUF and filter were analyzed as a single sample separately from the bottom half PUF section. This approach provided an assessment of analyte breakthrough using the sampling system for large sample volumes of approximately 4,000 m{sup 3} and 8,000 m{sup 3} for the 15-day and respectively.

  6. Modeling and analysis of sampling artifacts in measurements of gas-particle partitioning of semivolatile organic contaminants using filter-sorbent samplers

    NASA Astrophysics Data System (ADS)

    Wang, Xinke; Bi, Chenyang; Xu, Ying

    2015-09-01

    Measurements of gas/particle partition coefficients for semivolatile organic compounds (SVOCs) using filter-sorbent samplers can be biased if a fraction of gas-phase mass is measured erroneously as particle-phase due to sorption of SVOC gases to the filter, or, if a fraction of particle-phase mass is measured erroneously as gas-phase due to penetration of particles into the sorbent. A fundamental mechanistic model to characterize the air sampling process with filter-sorbent samplers for SVOCs was developed and partially validated. The potential sampling artifacts associated with measurements of gas-particle partitioning were examined for 19 SVOCs. Positive sampling bias (i.e., overestimation of gas/particle partition coefficients) was observed for almost all the SVOCs. For certain compounds, the measured partition coefficient was several orders of magnitude greater than the presumed value. It was found that the sampling artifacts can be ignored when the value of log [Kf /(Kp ṡCp , a) ] is less than 7. By normalizing the model, general factors that influence the sampling artifacts were investigated. Correlations were obtained between the dimensionless time required for the gas-phase SVOCs within the filter to reach steady state (Ts,s∗) and the chemical Vp values, which can be used to estimate appropriate sampling time. The potential errors between measured and actual gas/particle partition coefficients of SVOCs as a function of sampling velocity and time were calculated and plotted for a range of SVOCs (vapor pressures: 10-8 ∼ 10-3 Pa). These plots were useful in identifying bias from the sampling in previously-completed field measurements. Penetration of particles into the sorbent may result in significant underestimation of the partition coefficient for particles in the size range between 10 nm and 2 μm. For most of the selected compounds, backup filters can be used to correct artifacts effectively. However, for some compounds with very low vapor pressure

  7. Quick-change filter cartridge

    DOEpatents

    Rodgers, John C.; McFarland, Andrew R.; Ortiz, Carlos A.

    1995-01-01

    A quick-change filter cartridge. In sampling systems for measurement of airborne materials, a filter element is introduced into the sampled airstream such that the aerosol constituents are removed and deposited on the filter. Fragile sampling media often require support in order to prevent rupture during sampling, and careful mounting and sealing to prevent misalignment, tearing, or creasing which would allow the sampled air to bypass the filter. Additionally, handling of filter elements may introduce cross-contamination or exposure of operators to toxic materials. Moreover, it is desirable to enable the preloading of filter media into quick-change cartridges in clean laboratory environments, thereby simplifying and expediting the filter-changing process in the field. The quick-change filter cartridge of the present invention permits the application of a variety of filter media in many types of instruments and may also be used in automated systems. The cartridge includes a base through which a vacuum can be applied to draw air through the filter medium which is located on a porous filter support and held there by means of a cap which forms an airtight seal with the base. The base is also adapted for receiving absorbing media so that both particulates and gas-phase samples may be trapped for investigation, the latter downstream of the aerosol filter.

  8. SAMPLING AND ANALYSIS FOR POLYCHLORINATED DIBENZO-P-DIOXINS AND DIBENZOFURANS IN AMBIENT AIR

    EPA Science Inventory

    A short-term study for determination of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in ambient air in Green Bay, Wisconsin, has been completed. eneral Metals Works PS-1 air samplers equipped with particle filters and polyurethane foam (PUF)...

  9. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 6 2011-07-01 2011-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  10. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 6 2013-07-01 2013-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  11. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  12. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA...

  13. 32 CFR 806.27 - Samples of Air Force FOIA processing documents.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Samples of Air Force FOIA processing documents. 806.27 Section 806.27 National Defense Department of Defense (Continued) DEPARTMENT OF THE AIR FORCE ADMINISTRATION AIR FORCE FREEDOM OF INFORMATION ACT PROGRAM § 806.27 Samples of Air Force FOIA processing documents. (a) This section...

  14. Solvent Selection for Pressurized Liquid Extraction of Polymeric Sorbents Used in Air Sampling

    PubMed Central

    Primbs, Toby; Genualdi, Susan; Simonich, Staci

    2014-01-01

    Pressurized liquid extraction (PLE) was evaluated as a method for extracting semivolatile organic compounds (SOCs) from air sampling media; including quartz fiber filter (QFF), polyurethane foam (PUF), and a polystyrene divinyl benzene copolymer (XAD-2). Hansen solubility parameter plots were used to aid in the PLE solvent selection in order to reduce both co-extraction of polyurethane and save time in evaluating solvent compatibility during the initial steps of method development. A PLE solvent composition of 75:25% hexane:acetone was chosen for PUF. The XAD-2 copolymer was not solubilized under the PLE conditions used. The average percent PLE recoveries (and percent relative standard deviations) of 63 SOCs, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and organochlorine, amide, triazine, thiocarbamate, and phosphorothioate pesticides, were 76.7 (6.2), 79.3 (8.1), and 93.4 (2.9) % for the QFF, PUF, and XAD-2, respectively. PMID:18220448

  15. Environmental DNA sampling protocol - filtering water to capture DNA from aquatic organisms

    USGS Publications Warehouse

    Laramie, Matthew B.; Pilliod, David S.; Goldberg, Caren S.; Strickler, Katherine M.

    2015-01-01

    Environmental DNA (eDNA) analysis is an effective method of determining the presence of aquatic organisms such as fish, amphibians, and other taxa. This publication is meant to guide researchers and managers in the collection, concentration, and preservation of eDNA samples from lentic and lotic systems. A sampling workflow diagram and three sampling protocols are included as well as a list of suggested supplies. Protocols include filter and pump assembly using: (1) a hand-driven vacuum pump, ideal for sample collection in remote sampling locations where no electricity is available and when equipment weight is a primary concern; (2) a peristaltic pump powered by a rechargeable battery-operated driver/drill, suitable for remote sampling locations when weight consideration is less of a concern; (3) a 120-volt alternating current (AC) powered peristaltic pump suitable for any location where 120-volt AC power is accessible, or for roadside sampling locations. Images and detailed descriptions are provided for each step in the sampling and preservation process.

  16. Isokinetic air sampler

    DOEpatents

    Sehmel, George A.

    1979-01-01

    An isokinetic air sampler includes a filter, a holder for the filter, an air pump for drawing air through the filter at a fixed, predetermined rate, an inlet assembly for the sampler having an inlet opening therein of a size such that isokinetic air sampling is obtained at a particular wind speed, a closure for the inlet opening and means for simultaneously opening the closure and turning on the air pump when the wind speed is such that isokinetic air sampling is obtained. A system incorporating a plurality of such samplers provided with air pumps set to draw air through the filter at the same fixed, predetermined rate and having different inlet opening sizes for use at different wind speeds is included within the ambit of the present invention as is a method of sampling air to measure airborne concentrations of particulate pollutants as a function of wind speed.

  17. Recovery of waterborne oocysts of Cryptosporidium from water samples by the membrane-filter dissolution method.

    PubMed

    Graczyk, T K; Cranfield, M R; Fayer, R

    1997-01-01

    The cellulose-acetate membrane (CAM)-filter dissolution method implemented into a Millipore Glass Microanalysis system was used for recovery of Cryptosporidium parvum oocysts seeded into 25 l of drinking water in polyethylene carboy aspirator bottles. CAM-entrapped oocysts were detected by immunofluorescence microscopy. From 65 to 94 oocysts/l (mean 75 oocysts/l), 34.7% overall of the inoculated oocysts, were unrecovered as determined after the water had been drained from the bottle, rinsed with 1 l of eluting fluid (EF), and CAM-filtered. Efficiency rates of oocyst recovery ranged from 24.0% to 64.0% (mean 44.1%), without the use of EF and from 72.1% to 82.3% (mean 78.8%) when EF was used. To ensure a high recovery efficiency of Cryptosporidium oocysts from sampled water by the CAM-filter dissolution method, it is recommended that 1 l of EF per 25 l of water be used. PMID:9039693

  18. Urine sample preparation in 96-well filter plates for quantitative clinical proteomics.

    PubMed

    Yu, Yanbao; Suh, Moo-Jin; Sikorski, Patricia; Kwon, Keehwan; Nelson, Karen E; Pieper, Rembert

    2014-06-01

    Urine is an important, noninvasively collected body fluid source for the diagnosis and prognosis of human diseases. Liquid chromatography mass spectrometry (LC-MS) based shotgun proteomics has evolved as a sensitive and informative technique to discover candidate disease biomarkers from urine specimens. Filter-aided sample preparation (FASP) generates peptide samples from protein mixtures of cell lysate or body fluid origin. Here, we describe a FASP method adapted to 96-well filter plates, named 96FASP. Soluble urine concentrates containing ~10 μg of total protein were processed by 96FASP and LC-MS resulting in 700-900 protein identifications at a 1% false discovery rate (FDR). The experimental repeatability, as assessed by label-free quantification and Pearson correlation analysis for shared proteins among replicates, was high (R ≥ 0.97). Application to urinary pellet lysates which is of particular interest in the context of urinary tract infection analysis was also demonstrated. On average, 1700 proteins (±398) were identified in five experiments. In a pilot study using 96FASP for analysis of eight soluble urine samples, we demonstrated that protein profiles of technical replicates invariably clustered; the protein profiles for distinct urine donors were very different from each other. Robust, highly parallel methods to generate peptide mixtures from urine and other body fluids are critical to increase cost-effectiveness in clinical proteomics projects. This 96FASP method has potential to become a gold standard for high-throughput quantitative clinical proteomics. PMID:24797144

  19. Efficacy of serum samples stored on filter paper for the detection of antibody to Leptospira spp. by microagglutination test (MAT).

    PubMed

    Blanco, R M; Romero, E C

    2012-12-14

    The aim of this study was to investigate the microagglutination test (MAT) results in serum samples dried on filter paper and stored at different temperatures during 1day, 7days, 30days and 1year to determine the stability of sera antibody against leptospires. Serum samples collected onto filter paper for the detection of leptospires antibody was compared with MAT in a study of 300 serum samples from patients with suspected leptospirosis. Among 300 fresh serum samples analyzed by MAT 156 (52%) were positive and 144 (48%) negative. All the negative fresh serum samples were negative when dried on filter paper (specificity 100%). The sensitivity of MAT performed on dried serum samples was 100%. Storage on filter paper at room temperature and at 4°C for 1 and 7days did not affect the MAT titers. For up to 7days, 98.72% of dried serum samples had titers identical to those of the corresponding serum samples, and 1.18% of dried serum samples showed 1 dilution of difference. After a storage period of one month a prozone phenomenon was observed. After a storage period of one year all serum samples were negative. Serum samples collected onto filter paper are a convenient source of antibodies for serological diagnosis and epidemiological surveys. PMID:22960422

  20. Sampling and Analysis of Asbestos Fibers on Filter Media to Support Exposure Assessment: Bench-Scale Testing

    EPA Science Inventory

    Sampling efficiency is essential in exposure assessments of contaminants in air, as well as other matrices. In the measurement of airborne contaminants, it is critical to collect a sample of air containing representative contaminants in the air of concern, that is, contaminant c...

  1. GAS CHROMATOGRAPHY/MATRIX ISOLATION - INFRARED SPECTROMETRY FOR AIR SAMPLE ANALYSIS

    EPA Science Inventory

    This report describes the application of gas chromatography/matrix- solation infrared (GC/MI-IR) spectrometry to the analysIs of environmental air sample extracts. Samples that were analyzed include extracts from woodsmoke-impacted air, XAD-2 blanks, indoor air, and carpet sample...

  2. Geostationary Coastal and Air Pollution Events (GeoCAPE) Filter Radiometer (FR)

    NASA Technical Reports Server (NTRS)

    Kotecki, Carl; Chu, Martha; Wilson, Mark; Clark, Mike; Nanan, Bobby; Matson, Liz; McBirney, Dick; Smith, Jay; Earle, Paul; Choi, Mike; Stoneking, Eric; Luu, Kequan; Swinski, J. P.; Secunda, Mark; Brall, Aron; Verma, Sanjay; Hartman, Kathy R.

    2014-01-01

    The GeoCAPE Filter Radiometer (FR) Study is a different instrument type than all of the previous IDL GeoCape studies. The customer primary goals are to keep mass, volume and cost to a minimum while meeting the science objectives and maximizing flight opportunities by fitting on the largest number of GEO accommodations possible. Minimize total mission costs by riding on a commercial GEO satellite. For this instrument type, the coverage rate, km 2 min, was significantly increased while reducing the nadir ground sample size to 250m. This was accomplished by analyzing a large 2d area for each integration period. The field of view will be imaged on a 4k x 4k detector array of 15 micrometer pixels. Each ground pixel is spread over 2 x 2 detector pixels so the instantaneous field of view (IFOV) is 2048 X 2048 ground pixels. The baseline is, for each field of view 50 sequential snapshot images are taken, each with a different filter, before indexing the scan mirror to the next IFOV. A delta would be to add additional filters.

  3. Nanofiber Air Filters with High-Temperature Stability for Efficient PM2.5 Removal from the Pollution Sources.

    PubMed

    Zhang, Rufan; Liu, Chong; Hsu, Po-Chun; Zhang, Chaofan; Liu, Nian; Zhang, Jinsong; Lee, Hye Ryoung; Lu, Yingying; Qiu, Yongcai; Chu, Steven; Cui, Yi

    2016-06-01

    Here, we developed high-efficiency (>99.5%) polyimide-nanofiber air filters for the high temperature PM2.5 removal. The polyimide nanofibers exhibited high thermal stability, and the PM2.5 removal efficiency was kept unchanged when temperature ranged from 25-370 °C. These filters had high air flux with very low pressure drop. They could continuously work for >120 h for PM2.5 index >300. A field-test showed that they could effectively remove >99.5% PM particles from car exhaust at high temperature. PMID:27167892

  4. EFFECT OF STORAGE TIME AND STORAGE CONDITIONS ON ANTIBODY DETECTION IN BLOOD SAMPLES COLLECTED ON FILTER PAPER.

    PubMed

    Bevins, Sarah; Pappert, Ryan; Young, John; Schmit, Brandon; Kohler, Dennis; Baeten, Laurie

    2016-07-01

    Using filter paper to collect blood from wildlife for antibody analysis can be a powerful technique to simplify the collection, transport, and storage of blood samples. Despite these advantages, there are limited data that detail how long these samples can be stored and how storage conditions affect antibody longevity. We used blood samples collected on filter paper from coyotes experimentally infected with Yersinia pestis to determine optimum sample storage conditions over time. Blood samples collected on filter paper were stored for 454 d or more in four groups: 1) at ambient temperature and at ambient relative humidity, 2) at ambient temperature with desiccant, 3) at 4 C with desiccant, and 4) at -20 C with desiccant. Samples stored at 4 C or -20 C with desiccant had detectable antibody for a longer period of time than the samples stored at room temperature. PMID:27187032

  5. Passive Samplers for Investigations of Air Quality: Method Description, Implementation, and Comparison to Alternative Sampling Methods

    EPA Science Inventory

    This Paper covers the basics of passive sampler design, compares passive samplers to conventional methods of air sampling, and discusses considerations when implementing a passive sampling program. The Paper also discusses field sampling and sample analysis considerations to ensu...

  6. Some Analysis of Integrated-count Processing for Fixed-filter Continuous Particulate Air Monitors.

    PubMed

    Evans, William C

    2016-09-01

    A calculation for estimating concentrations of long-lived airborne particulate radioactivity using fixed-filter continuous air monitors is given in an ISO standard. The method uses counts integrated over relatively long time intervals, rather than the 'instantaneous' count rates that in digital systems are evaluated using much shorter time intervals and some form of variance-reduction filtering. This article presents three ways of deriving and interpreting this calculation, based on previously published mathematical models that were derived from first principles. The method is also extended here to apply for short-lived activity. Some statistical properties of the estimator are discussed, including its time-dependent variance and the presence of strong autocorrelation in the concentration estimates. An interactive simulation was used to examine the performance of the concentration estimation, using physically plausible concentration time-dependence profiles; example plots are provided. The conclusion of these studies is that the method, as modified herein, can perform remarkably well in providing periodic average-concentration estimates for both long- and short-lived activity, and it should be considered an appropriate method in those situations where the tracking of a time-dependent concentration is deemed necessary. PMID:27472754

  7. Sampling of air streams and incorporation of samples in the Microtox{trademark} toxicity testing system

    SciTech Connect

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

    1997-10-01

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

  8. An Autosampler and Field Sample Carrier for Maximizing Throughput Using an Open-Air, Surface Sampling Ion Source for MS

    EPA Science Inventory

    A recently developed, commercially available, open-air, surface sampling ion source for mass spectrometers provides individual analyses in several seconds. To realize its full throughput potential, an autosampler and field sample carrier were designed and built. The autosampler ...

  9. Comparison of filters for concentrating microbial indicators and pathogens in lake-water samples

    USGS Publications Warehouse

    Francy, Donna S.; Stelzer, Erin A.; Brady, Amie M.G.; Huitger, Carrie; Bushon, Rebecca N.; Ip, Hon S.; Ware, Michael W.; Villegas, Eric N.; Gallardo, Vincent; Lindquist, H.D. Alan

    2013-01-01

    Bacterial indicators are used to indicate increased health risk from pathogens and to make beach closure and advisory decisions; however, beaches are seldom monitored for the pathogens themselves. Studies of sources and types of pathogens at beaches are needed to improve estimates of swimming-associated health risks. It would be advantageous and cost-effective, especially for studies conducted on a regional scale, to use a method that can simultaneously filter and concentrate all classes of pathogens from the large volumes of water needed to detect pathogens. In seven recovery experiments, stock cultures of viruses and protozoa were seeded into 10-liter lake water samples, and concentrations of naturally occurring bacterial indicators were used to determine recoveries. For the five filtration methods tested, the highest median recoveries were as follows: glass wool for adenovirus (4.7%); NanoCeram for enterovirus (14.5%) and MS2 coliphage (84%); continuous-flow centrifugation (CFC) plus Virocap (CFC+ViroCap) for Escherichia coli (68.3%) and Cryptosporidium (54%); automatic ultrafiltration (UF) for norovirus GII (2.4%); and dead-end UF for Enterococcus faecalis (80.5%), avian influenza virus (0.02%), and Giardia (57%). In evaluating filter performance in terms of both recovery and variability, the automatic UF resulted in the highest recovery while maintaining low variability for all nine microorganisms. The automatic UF was used to demonstrate that filtration can be scaled up to field deployment and the collection of 200-liter lake water samples.

  10. Particle Concentrations and Effectiveness of Free-Standing Air Filters in Bedrooms of Children with Asthma in Detroit, Michigan

    PubMed Central

    Du, Liuliu; Batterman, Stuart; Parker, Edith; Godwin, Christopher; Chin, Jo-Yu; O'Toole, Ashley; Robins, Thomas; Brakefield-Caldwell, Wilma; Lewis, Toby

    2011-01-01

    Asthma can be exacerbated by environmental factors including airborne particulate matter (PM) and environmental tobacco smoke (ETS). We report on a study designed to characterize PM levels and the effectiveness of filters on pollutant exposures of children with asthma. 126 households with an asthmatic child in Detroit, Michigan, were recruited and randomized into control or treatment groups. Both groups received asthma education; the latter also received a free-standing high efficiency air filter placed in the child’s bedroom. Information regarding the home, emission sources, and occupant activities was obtained using surveys administered to the child's caregiver and a household inspection. Over a one-week period, we measured PM, carbon dioxide (CO2), environmental tobacco smoke (ETS) tracers, and air exchange rates (AERs). Filters were installed at midweek. Before filter installation, PM concentrations averaged 28 µg m−3, number concentrations averaged 70,777 and 1,471 L−1 in 0.3–1.0 and 1–5 µm size ranges, respectively, and the median CO2 concentration was 1,018 ppm. ETS tracers were detected in 23 of 38 homes where smoking was unrestricted and occupants included smokers and, when detected, PM concentrations were elevated by an average of 15 µg m−3. Filter use reduced PM concentrations by an average of 69 to 80%. Simulation models representing location conditions show that filter air flow, room volume and AERs are the key parameters affecting PM removal, however, filters can achieve substantial removal in even "worst" case applications. While PM levels in homes with asthmatic children can be high, levels can be dramatically reduced using filters. PMID:21874085

  11. The impact of mass flow and masking on the pressure drop of air filter in heavy-duty diesel engine

    NASA Astrophysics Data System (ADS)

    Hoseeinzadeh, Sepideh; Gorji-Bandpy, Mofid

    2012-04-01

    This paper presents a computational fluid dynamics (CFD) calculation approach to predict and evaluate the impact of the mass-flow inlet on the pressure drop of turbocharger`s air filtfer in heavy-duty diesel engine. The numerical computations were carried out using a commercial CFD program whereas the inlet area of the air filter consisted of several holes connected to a channel. After entering through the channel, the air passes among the holes and enters the air filter. The effect of masking holes and hydraulic diameter is studied and investigated on pressure drop. The results indicate that pressure drop increase with decreasing of hydraulic diameter and masking of the holes has considerable affect on the pressure drop.

  12. Evaluation of sampling methods for measuring exposure to volatile inorganic acids in workplace air. Part 1: sampling hydrochloric acid (HCl) and nitric acid (HNO₃) from a test gas atmosphere.

    PubMed

    Howe, Alan; Musgrove, Darren; Breuer, Dietmar; Gusbeth, Krista; Moritz, Andreas; Demange, Martine; Oury, Véronique; Rousset, Davy; Dorotte, Michel

    2011-08-01

    Historically, workplace exposure to the volatile inorganic acids hydrochloric acid (HCl) and nitric acid (HNO(3)) has been determined mostly by collection on silica gel sorbent tubes and analysis of the corresponding anions by ion chromatography (IC). However, HCl and HNO(3) can be present in workplace air in the form of mist as well as vapor, so it is important to sample the inhalable fraction of airborne particles. As sorbent tubes exhibit a low sampling efficiency for inhalable particles, a more suitable method was required. This is the first of two articles on "Evaluation of Sampling Methods for Measuring Exposure to Volatile Inorganic Acids in Workplace Air" and describes collaborative sampling exercises carried out to evaluate an alternative method for sampling HCl and HNO(3) using sodium carbonate-impregnated filters. The second article describes sampling capacity and breakthrough tests. The method was found to perform well and a quartz fiber filter impregnated with 500 μL of 1 M Na(2)CO(3) (10% (m/v) Na(2)CO(3)) was found to have sufficient sampling capacity for use in workplace air measurement. A pre-filter is required to remove particulate chlorides and nitrates that when present would otherwise result in a positive interference. A GSP sampler fitted with a plastic cone, a closed face cassette, or a plastic IOM sampler were all found to be suitable for mounting the pre-filter and sampling filter(s), but care has to be taken with the IOM sampler to ensure that the sampler is tightly closed to avoid leaks. HCl and HNO(3) can react with co-sampled particulate matter on the pre-filter, e.g., zinc oxide, leading to low results, and stronger acids can react with particulate chlorides and nitrates removed by the pre-filter to liberate HCl and HNO(3), which are subsequently collected on the sampling filter, leading to high results. However, although there is this potential for both positive and negative interferences in the measurement, these are unavoidable

  13. Experimental Study on Ultrafine Particle Removal Performance of Portable Air Cleaners with Different Filters in an Office Room.

    PubMed

    Ma, Huan; Shen, Henggen; Shui, Tiantian; Li, Qing; Zhou, Liuke

    2016-01-01

    Size- and time-dependent aerodynamic behaviors of indoor particles, including PM1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different filters. In-situ real-time measurements were taken using an optical particle counter. The filtration characteristics of filter media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret filter (EE) medium shows better initial removal efficiency than the high efficiency (HE) medium in the 0.3-3.5 μm particle size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 10⁴ m³/m². The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC) with the pre-filter (PR) or the active carbon granule filter (CF) was relatively poor. While PAC with the pre-filter and the high efficiency filter (PR&HE) showed maximum single-pass efficiency for PM1.0 (88.6%), PAC with the HE was the most effective at removing PM1.0. The enhancement of PR with HE and electret filters augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized particles could be greater than for PACs without PR. Without regard to the lifetime, the electret filters performed better with respect to resource saving and purification improvement. A most penetrating particle size range (MPPS: 0.4-0.65 μm) exists in both HE and electret filters; the MPPS tends to become larger after HE and electret filters are combined with PR. These results serve to provide a better understanding of the indoor particle removal performance of PACs when combined with different kinds of filters in school

  14. Experimental Study on Ultrafine Particle Removal Performance of Portable Air Cleaners with Different Filters in an Office Room

    PubMed Central

    Ma, Huan; Shen, Henggen; Shui, Tiantian; Li, Qing; Zhou, Liuke

    2016-01-01

    Size- and time-dependent aerodynamic behaviors of indoor particles, including PM1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different filters. In-situ real-time measurements were taken using an optical particle counter. The filtration characteristics of filter media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret filter (EE) medium shows better initial removal efficiency than the high efficiency (HE) medium in the 0.3–3.5 μm particle size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 104 m3/m2. The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC) with the pre-filter (PR) or the active carbon granule filter (CF) was relatively poor. While PAC with the pre-filter and the high efficiency filter (PR&HE) showed maximum single-pass efficiency for PM1.0 (88.6%), PAC with the HE was the most effective at removing PM1.0. The enhancement of PR with HE and electret filters augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized particles could be greater than for PACs without PR. Without regard to the lifetime, the electret filters performed better with respect to resource saving and purification improvement. A most penetrating particle size range (MPPS: 0.4–0.65 μm) exists in both HE and electret filters; the MPPS tends to become larger after HE and electret filters are combined with PR. These results serve to provide a better understanding of the indoor particle removal performance of PACs when combined with different kinds of filters in school

  15. Interferences of atmospheric oxidants in the sampling of aldehydes using sep pak C18 mciro columns coated wtih 2,4-DNPH: The use of cellulose filters coated with KI as a scrubber

    SciTech Connect

    Andrade, J.B. de; Andrade, V.A.S. de; Pinheiro, H.L.C.

    1995-12-01

    Measurements of formaldehyde and acetaldehyde in the atmosphere often involve the use of DNPH-coated cartridges. During sampling, ozone and other atmospheric oxidants may react with DNPH and/or the carbonyl-DNPH, thus resulting in a negative bias. In this study, ambient air has been collected using co-located DNPH C{sub 18} cartridges with and without a filter coated with KI to remove ozone and other oxidants. Concentrations of formaldehyde and acetaldehyde measured without the KI filter were lower than those measured with a KI filter. Implications for ambient measurements of carbonyls in the presence of atmospheric ozone are discussed.

  16. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e.,...

  17. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e.,...

  18. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e.,...

  19. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e.,...

  20. 42 CFR 84.179 - Non-powered air-purifying particulate respirators; filter identification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...; filter identification. 84.179 Section 84.179 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH...-purifying particulate respirators; filter identification. (a) The respirator manufacturer, as part of the application for certification, shall specify the filter series and the filter efficiency level (i.e.,...

  1. Preparation of Nanofibrous Metal-Organic Framework Filters for Efficient Air Pollution Control.

    PubMed

    Zhang, Yuanyuan; Yuan, Shuai; Feng, Xiao; Li, Haiwei; Zhou, Junwen; Wang, Bo

    2016-05-11

    Environmental challenges especially air pollution (particulate matter (PM) and toxic gases) pose serious threats to public health globally. Metal-organic frameworks (MOFs) are crystalline materials with high porosity, tunable pore size, and rich functionalities, holding the promise for poisonous pollutants capture. Here, nanocrystals of four unique MOF structures are processed into nanofibrous filters (noted as MOFilter) with high MOF loadings (up to 60 wt %). The MOFilters show high PM removal efficiencies up to 88.33 ± 1.52% and 89.67 ± 1.33% for PM2.5 and PM10, respectively, in the hazy environment, and the performance remains largely unchanged over 48 h of continuous filtration. For the first time, the interactions between such porous crystalline material and particulate pollutants were explored. These thin MOFilters can further selectively capture and retain SO2 when exposed to a stream of SO2/N2 mixture, and their hierarchical nanostructures can easily permeate fresh air at high gas flow rate with the pressure drop <20 Pa. PMID:27090776

  2. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS, W.L. GORE & ASSOCIATES, INC. LYSB3 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size for particles equal to or smaller than...

  3. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT, BAGHOUSE FILTRATION PRODUCTS, W.L. GORE & ASSOCIATES, INC., L4427 FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size of those particles equal to and smalle...

  4. ENVIRONMENTAL TECHNOLOGY VERIFICATION REPORT: BAGHOUSE FILTRATION PRODUCTS, BWF AMERICA, INC. GRADE 700 MPS POLYESTER FELT FILTER SAMPLE

    EPA Science Inventory

    Baghouse filtration products (BFPs) were evaluated by the Air Pollution Control Technology (APCT) Verification Center. The performance factor verified was the mean outlet particle concentration for the filter fabric as a function of the size for particles equal to or smaller than...

  5. The development of point-of-use water filters as sampling devices in bioforensics: extent of microbial sorption and elution.

    PubMed

    Sedillo, Jennifer L; Quintana, Ayshea; Souza, Kathryn; Oshima, Kevin H; Smith, Geoffrey B

    2008-06-01

    The foundational idea for this project is that household faucet-mounted water filters may be used as bioforensic sampling devices to detect the extent of a potential bioagent release in domestic water supplies. An optimized eluent solution was determined experimentally by quantifying recoveries of microorganisms from point-of-use (POU) drinking water filters. The optimized extraction protocol was then used in mock bioagent release experiments to determine the feasibility of POU filters as bioforensic sampling devices. Bacillus atrophaeus spores, Escherichia coli and PP7 virus were exposed to filters and the number of attached organisms was determined by enumerating the unattached organisms on selective agar media. Subsequently, the filters were eluted and the percent of extracted organisms was determined based on the number of attached organisms. Two popular brands of carbon block filters retained 92%-99% of representative virus, spore and vegetative bacteria. In back-flush elutions of single filters, the most efficient eluent was identified as a combination of 1% peptone and 1% Tween-80, and extraction recovered 25.4% (+/-17.5%) of attached E. coli, 20.4% (+/-3.6%) of B. atrophaeus spores, and 9.4% (+/-5.2%) of PP7 virions (+/- standard deviations). In bioagent release studies in which filters were challenged with 100 agents mL(-1), greater than 99% of the spores were retained by the filters, and the percent of attached spores that were recovered ranged from 10.4% at day 0 to 4.3% five days after the release event (averaged from five separate experiments). In contrast, E. coli, Salmonella typhimurium and PP7 virus were rapidly inactivated in the chlorinated tap water, indicating their improbable survival in chlorinated water supplies. It is therefore concluded that household water filters can be used as microbial sampling devices for bioforensic applications in the event of a bioagent release in domestic drinking water supplies. PMID:18528538

  6. Semi-volatile organic compounds in heating, ventilation, and air-conditioning filter dust in retail stores.

    PubMed

    Xu, Y; Liang, Y; Urquidi, J R; Siegel, J A

    2015-02-01

    Retail stores contain a wide range of products that can emit a variety of indoor pollutants. Among these chemicals, phthalate esters and polybrominated diphenyl ethers (PBDEs) are two important categories of semi-volatile organic compounds (SVOCs). Filters in heating, ventilation, and air-conditioning (HVAC) system collect particles from large volumes of air and thus potentially provide spatially and temporally integrated SVOC concentrations. This study measured six phthalate and 14 PBDE compounds in HVAC filter dust in 14 retail stores in Texas and Pennsylvania, United States. Phthalates and PBDEs were widely found in the HVAC filter dust in retail environment, indicating that they are ubiquitous indoor pollutants. The potential co-occurrence of phthalates and PBDEs was not strong, suggesting that their indoor sources are diverse. The levels of phthalates and PBDEs measured in HVAC filter dust are comparable to concentrations found in previous investigations of settled dust in residential buildings. Significant correlations between indoor air and filter dust concentrations were found for diethyl phthalate, di-n-butyl phthalate, and benzyl butyl phthalate. Reasonable agreement between measurements and an equilibrium model to describe SVOC partitioning between dust and gas-phase is achieved. PMID:24766478

  7. Effects of ceiling-mounted HEPA-UV air filters on airborne bacteria concentrations in an indoor therapy pool building.

    PubMed

    Kujundzic, Elmira; Zander, David A; Hernandez, Mark; Angenent, Largus T; Henderson, David E; Miller, Shelly L

    2005-02-01

    The purpose of this study was to assess the effectiveness of a new generation of high-volume, ceiling-mounted high-efficiency particulate air (HEPA)-ultraviolet (UV) air filters (HUVAFs) for their ability to remove or inactivate bacterial aerosol. In an environmentally controlled full-scale laboratory chamber (87 m3), and an indoor therapy pool building, the mitigation ability of air filters was assessed by comparing concentrations of total bacteria, culturable bacteria, and airborne endotoxin with and without the air filters operating under otherwise similar conditions. Controlled chamber tests with pure cultures of aerosolized Mycobacterium parafortuitum cells showed that the HUVAF unit tested provided an equivalent air-exchange rate of 11 hr(-1). Using this equivalent air-exchange rate as a design basis, three HUVAFs were installed in an indoor therapy pool building for bioaerosol mitigation, and their effectiveness was studied over a 2-year period. The HUVAFs reduced concentrations of culturable bacteria by 69 and 80% during monitoring periods executed in respective years. The HUVAFs reduced concentrations of total bacteria by 12 and 76% during the same monitoring period, respectively. Airborne endotoxin concentrations were not affected by the HUVAF operation. PMID:15796111

  8. Sampling and conditioning artifacts of PM2.5 in filter-based samplers

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Nan; Lin, Sih-Fan; Awasthi, Amit; Tsai, Chuen-Jinn; Wu, Yueh-Chuen; Chen, Chung-Fang

    2014-03-01

    Field studies were conducted at Taiwan National Chiao-Tung University (NCTU) campus to evaluate the evaporation loss of fine particles (PM2.5) collected by the multi-filter PM10-PM2.5 sampler (MFPPS), which was collocated with a dichotomous sampler (Dichot, Andersen, Model SA-241), a WINS PM2.5 sampler (Thermo, Model 2000-FRM), and a tapered element oscillating microbalance with the filter dynamic measurement system (TEOM-FDMS, Thermo, Model 1405-DF). Porous-metal denuder samplers (PDSs) were installed in sampling channels of the MFPPS to measure the concentration of evaporated ion species. Results showed that the evaporation loss in PM2.5 was severe during sampling, accounting for 5.8-36.0% of the corrected PM2.5 concentration and the percentage increased with decreasing loaded particle mass and increasing filtration velocity. During 24-h sampling, the evaporated NH4+, NO3- and Cl- concentrations accounted for 9.5 ± 6.2, 5.4 ± 3.7, and 2.0 ± 1.3% in corrected PM2.5 concentration, respectively, or 46.4 ± 19.2, 66.9 ± 18.5, and 74.4 ± 14.0% in the concentration of each species, respectively. Due to the evaporation loss, PM2.5 concentrations measured by the WINS, Dichot, and MFPPS were lower than those the TEOM-FDMS by 16.6 ± 9.0, 15.2 ± 10.6 and 12.5 ± 8.8%, respectively. When the MFPPS PM2.5 concentrations were corrected for the evaporated loss determined by the PDS, good agreement with those by the TEOM-FDMS was achieved.

  9. Collection and analysis of NASA clean room air samples

    NASA Technical Reports Server (NTRS)

    Sheldon, L. S.; Keever, J.

    1985-01-01

    The environment of the HALOE assembly clean room at NASA Langley Research Center is analyzed to determine the background levels of airborne organic compounds. Sampling is accomplished by pumping the clean room air through absorbing cartridges. For volatile organics, cartridges are thermally desorbed and then analyzed by gas chromatography and mass spectrometry, compounds are identified by searching the EPA/NIH data base using an interactive operator INCOS computer search algorithm. For semivolatile organics, cartridges are solvent entracted and concentrated extracts are analyzed by gas chromatography-electron capture detection, compound identification is made by matching gas chromatogram retention times with known standards. The detection limits for the semivolatile organics are; 0.89 ng cu m for dioctylphlhalate (DOP) and 1.6 ng cu m for polychlorinated biphenyls (PCB). The detection limit for volatile organics ranges from 1 to 50 parts per trillion. Only trace quantities of organics are detected, the DOP levels do not exceed 2.5 ng cu m and the PCB levels do not exceed 454 ng cu m.

  10. EFFECT OF VENTILATION SYSTEMS AND AIR FILTERS ON DECAY RATES OF PARTICLES PRODUCED BY INDOOR SOURCES IN AN OCCUPIED TOWNHOUSE

    EPA Science Inventory

    Several studies have shown the importance of particle losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct filter on particle loss rates. In an attempt to provide such data, we me...

  11. Evaluation of a sampling and analysis method for determination of polyhalogenated dibenzo-p-dioxins and dibenzofurans in ambient air

    SciTech Connect

    Harless, R.L.; Lewis, R.G.; McDaniel, D.D.; Gibson, J.F.; Dupuy, A.E.

    1991-01-01

    General Metals Works PS-1 PUF air samplers and an analytical method based on high resolution gas chromatography - high resolution mass spectrometry (HRGC-HRMS) were evaluated for determination of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDDs/PCDFs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDDs/PBDFs) and bromo/chloro dibenzo-p-dioxins and dibenzofurans (BCDDs/BCDFs) in ambient air. Dilute solutions of these compounds and (13)C12-1,2,3,4-TCDD were used to spike the filters of PS-1 air samplers which were then operated 24 hrs to sample 350-400 cu m ambient air. After sampling, each quartz-fiber filter and polyurethane foam (PUF) were spiked with (13)C12-labeled PCDD, PCDF, PBDD, and PBDF internal standards before separate Soxhlet extractions with benzene. The extracts were subjected to an acid/base clean-up procedure followed by clean-up on microcolumns of silica gel, alumina, and carbon and then analyzed by HRGC-HRMS. Results derived from the study indicated the PS-1 ambient air samplers and the analytical procedures were very efficient and that pg/cu m and sub-pg/cu m levels of total PCDDs/PCDFs, PBDDs/PBDFs, BCDDs/BCDFs, and 2,3,7,8-substituted congeners could be accurately measured. Background levels of these compounds in the ambient air were also determined. Total PCDDs, PCDFs, TBDFs, and PeBDFs were detected in a low concentration range of 0.3 to 3.0 pg/cu m.

  12. Denuder/filter sampling of organic acids and organosulfates at urban and boreal forest sites: Gas/particle distribution and possible sampling artifacts

    NASA Astrophysics Data System (ADS)

    Kristensen, Kasper; Bilde, Merete; Aalto, Pasi P.; Petäjä, Tuukka; Glasius, Marianne

    2016-04-01

    Carboxylic acids and organosulfates comprise an important fraction of atmospheric secondary organic aerosols formed from both anthropogenic and biogenic precursors. The partitioning of these compounds between the gas and particle phase is still unclear and further research is warranted to better understand the abundance and effect of organic acids and organosulfates on the formation and properties of atmospheric aerosols. This work compares atmospheric aerosols collected at an urban and a boreal forest site using two side-by-side sampling systems; a high volume sampler (HVS) and a low volume (LVS) denuder/filter sampling system allowing for separate collection of gas- and particle-phase organics. All particle filters and denuder samples were collected at H.C. Andersen Boulevard (HCAB), Copenhagen, Denmark in the summer of 2010, and at the remote boreal forest site at Hyytiälä forestry field station in Finland in the summer of 2012. The chemical composition of gas- and particle-phase secondary organic aerosol was investigated by ultra-high performance liquid chromatography/electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOFMS), with a focus on carboxylic acids and organosulfates. Results show gas-phase concentrations higher than those observed in the particle phase by a factor of 5-6 in HCAB 2010 and 50-80 in Hyytiälä 2012. Although abundant in the particle phase, no organosulfates were detected in the gas phase at either site. Through a comparison of samples collected by the HVS and the LVS denuder/filter sampling system we evaluate the potential artifacts associated with sampling of atmospheric aerosols. Such comparison shows that particle phase concentrations of semi-volatile organic acids obtained from the filters collected by HVS are more than two times higher than concentrations obtained from filters collected using LVS denuder/filter system. In most cases, higher concentrations of organosulfates are observed in particles

  13. XANES Speciation of P in Environmental Samples: An Assessment of Filter Media for on-Site Wastewater Treatment

    SciTech Connect

    Eveborn, D.; Gustafsson, J; Hesterberg, D; Hillier, S

    2009-01-01

    X-ray absorption near edge structure (XANES) spectroscopy is a useful technique for characterization of chemical species of phosphorus in complex environmental samples. To develop and evaluate bed filters as sustainable on-site wastewater treatment solutions, our objective in this study was to determine the chemical forms of accumulated phosphorus in a selection of promising filter materials: Filtralite P, Filtra P, Polonite, Absol, blast furnace slag, and wollastonite. Full-scale operational wastewater-treatment systems were sampled and in addition, filter samples collected from laboratory studies provided access to additional media and complementary samples. Phosphorus species were characterized using phosphorus K-edge XANES spectroscopy, complemented by X-ray powder diffraction (XRPD) and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). No systematic differences could be seen in the results between laboratory- and full-scale samples. All six filter media contained significant amounts of crystalline calcium phosphates. Some samples also contained amorphous calcium phosphate (>60% of total P in Absol). In Filtralite P and blast furnace slag, more than 35% of the accumulated phosphorus was associated with Fe or Al. Both the power and shortcomings of XANES analysis for characterizing P species in these filter media are discussed.

  14. Interconversion of chromium species during air sampling: effects of O3, NO2, SO2, particle matrices, temperature, and humidity.

    PubMed

    Huang, Lihui; Fan, Zhihua Tina; Yu, Chang Ho; Hopke, Philip K; Lioy, Paul J; Buckley, Brian T; Lin, Lin; Ma, Yingjun

    2013-05-01

    The interconversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) interconversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched (53)Cr(VI) and (50)Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were precollected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 h at 16.7 LPM flow rate at designated temperature (20 and 31 °C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on (53)Cr(VI) reduction, with (53)Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced (53)Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote (50)Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) interconversion during sampling. Correction of the interconversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements. PMID:23550818

  15. Disk filter

    DOEpatents

    Bergman, Werner

    1986-01-01

    An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

  16. Disk filter

    DOEpatents

    Bergman, W.

    1985-01-09

    An electric disk filter provides a high efficiency at high temperature. A hollow outer filter of fibrous stainless steel forms the ground electrode. A refractory filter material is placed between the outer electrode and the inner electrically isolated high voltage electrode. Air flows through the outer filter surfaces through the electrified refractory filter media and between the high voltage electrodes and is removed from a space in the high voltage electrode.

  17. Breakthrough of 1,3-dichloropropene and chloropicrin from 600 mg XAD-4 air sampling tubes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Accurately measuring air concentrations of agricultural fumigants is important for the regulation of air quality. Understanding the conditions under which sorbent tubes can effectively retain such fumigants during sampling is critical in mitigating chemical breakthrough from the tubes and facilitati...

  18. Recovery of Cryptosporidium oocysts from small and large volume water samples using a compressed foam filter system.

    PubMed

    Sartory, D P; Parton, A; Parton, A C; Roberts, J; Bergmann, K

    1998-12-01

    A novel filter system comprising open cell reticulated foam rings compressed between retaining plates and fitted into a filtration housing was evaluated for the recovery of oocysts of Cryptosporidium from water. Mean recoveries of 90.2% from seeded small and large volume (100-2000 l) tap water samples, and 88.8% from 10-20 l river water samples, were achieved. Following a simple potassium citrate flotation concentrate clean-up procedure, mean recoveries were 56.7% for the tap water samples and 60.9% for river water samples. This represents a marked improvement in capture and recovery of Cryptosporidium oocysts from water compared with conventional polypropylene wound cartridge filters and membrane filters. PMID:9871348

  19. Evaluation of sampling and analytical methodology for polynuclear aromatic compounds in indoor air. Final report, 1 March-30 September 1985

    SciTech Connect

    Chuang, C.C.; Mack, G.A.; Mondron, P.J.; Petersen, B.A.

    1985-10-01

    The objective of this project was to develop a generic sampling and analytical methodology to characterize the polynuclear aromatic hydrocarbon (PAH) concentrations in air within various microenvironments. The following three studies were performed: evaluation of analytical methods, design of a sampling method, and design of a pilot study. Two analytical methods, high performance liquid chromatography with ultraviolet adsorption and fluorescence detection and gas chromatography/mass spectrometry, were evaluated for the determination of PAHs and their derivatives in air within microenvironments. The results showed that gas chromatography/positive chemical ionization massspectrometry with data acquisition in the selected ion-monitoring mode is the preferred analytical approach. A modified EPA high-volume sampler, consisting of a quartz fiber filter and a polyurethane foam cartridge, is proposed for use in a future experimental study. A literature review was conducted to determine what is known about the contribution of cigarette smoke to the levels of PAHs in air within microenvironments and to evaluate the use of quinoline and isoquinoline as possible marker compounds for the levels of cigarette smoke. A pilot study was designed to assess PAH levels in air found in residences. A study using this design, was conducted in Columbus, Ohio, during the winter of 1983/84. These results can then be applied to a future large-scale study involving the measurement of human exposure to PAH in air.

  20. Evaluation of Ag nanoparticle coated air filter against aerosolized virus: Anti-viral efficiency with dust loading.

    PubMed

    Joe, Yun Haeng; Park, Dae Hoon; Hwang, Jungho

    2016-01-15

    In this study, the effect of dust loading on the anti-viral ability of an anti-viral air filter was investigated. Silver nanoparticles approximately 11 nm in diameter were synthesized via a spark discharge generation system and were used as anti-viral agents coated onto a medium air filter. The pressure drop, filtration efficiency, and anti-viral ability of the filter against aerosolized bacteriophage MS2 virus particles were tested with dust loading. The filtration efficiency and pressure drop increased with dust loading, while the anti-viral ability decreased. Theoretical analysis of anti-viral ability with dust loading was carried out using a mathematical model based on that presented by Joe et al. (J. Hazard. Mater.; 280: 356-363, 2014). Our model can be used to compare anti-viral abilities of various anti-viral agents, determine appropriate coating areal density of anti-viral agent on a filter, and predict the life cycle of an anti-viral filter. PMID:26434534

  1. Methods for polynuclear aromatic hydrocarbon determination in air samples using polar-bonded phase HPLC and GC-MS with application to oil refinery samples

    SciTech Connect

    Karlesky, K.L.

    1985-01-01

    Particle samples were collected using high volume air samplers fitted with glass fiber filters or with a cascade impactor containing paper filters. They were then cleaned using either extraction with dimethylsulfoxide and pentane or utilizing a small cartridge containing a diamine polar-bonded phase material, the second method being more effective. Vapor phase PAH were sampled using an apparatus designed in the laboratory. After collection, the resins were desorbed with solvent and the PAH content was determined. The suitability of the resins decrease in the following order: Amberlite XAD-2, Chromosorb 105, Tenax GC, coconut charcoal, and Ambesorb XE-348. High performance liquid chromatography (HPLC) was used to determine the behavior of PAH in the normal and reversed phase on polar-bonded phases containing amine, diamine, and pyrrolidone substrates. Results support the proposed mechanism in the normal phase and indicate that both a partitioning and liquid-solid adsorption mechanism takes place in the reversed phase depending upon the mobile phase. Occasionally, these polar-bonded phases can be deactivated by the formation of amine-carbonyl complexes from polar aldehydes or ketones in the solvent or sample. Deactivation can be reversed by flushing with water to hydrolyze the Schiff's base imine back to the amine. Gas chromatography-mass spectroscopy (GC-MS) was used to analyze air samples from oil refineries in Port Arthur, collected over a period of three years. The analytical procedures are applied to the collected samples to determine if they contain detectable amounts of PAH. The GC-MS analysis was adequate for this study but the use of SIM detection is preferred because of the greater sensitivity for PAH.

  2. 30 CFR 71.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Approved sampling devices; operation; air... OF UNDERGROUND COAL MINES Sampling Procedures § 71.205 Approved sampling devices; operation; air... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  3. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved sampling devices; operation; air... DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  4. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Approved sampling devices; operation; air... DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  5. 30 CFR 70.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved sampling devices; operation; air... § 70.205 Approved sampling devices; operation; air flowrate. (a) Sampling devices approved in... Secretary of Health and Human Services for the particular device. (b) Except as provided in paragraph (d)...

  6. 30 CFR 71.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved sampling devices; operation; air... OF UNDERGROUND COAL MINES Sampling Procedures § 71.205 Approved sampling devices; operation; air... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  7. 30 CFR 70.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved sampling devices; operation; air... § 70.205 Approved sampling devices; operation; air flowrate. (a) Sampling devices approved in... Secretary of Health and Human Services for the particular device. (b) Except as provided in paragraph (d)...

  8. 30 CFR 70.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Approved sampling devices; operation; air... § 70.205 Approved sampling devices; operation; air flowrate. (a) Sampling devices approved in... Secretary of Health and Human Services for the particular device. (b) Except as provided in paragraph (d)...

  9. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Approved sampling devices; operation; air... DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  10. 30 CFR 70.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Approved sampling devices; operation; air... § 70.205 Approved sampling devices; operation; air flowrate. (a) Sampling devices approved in... Secretary of Health and Human Services for the particular device. (b) Except as provided in paragraph (d)...

  11. 30 CFR 71.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved sampling devices; operation; air... OF UNDERGROUND COAL MINES Sampling Procedures § 71.205 Approved sampling devices; operation; air... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  12. 30 CFR 71.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved sampling devices; operation; air... OF UNDERGROUND COAL MINES Sampling Procedures § 71.205 Approved sampling devices; operation; air... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  13. 30 CFR 71.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Approved sampling devices; operation; air... OF UNDERGROUND COAL MINES Sampling Procedures § 71.205 Approved sampling devices; operation; air... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  14. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Approved sampling devices; operation; air... DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures § 90.205 Approved sampling devices; operation; air flowrate... flowrate as prescribed by the Secretary and the Secretary of Health and Human Services for the...

  15. 30 CFR 70.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Approved sampling devices; operation; air... § 70.205 Approved sampling devices; operation; air flowrate. (a) Sampling devices approved in... Secretary of Health and Human Services for the particular device. (b) Except as provided in paragraph (d)...

  16. Efficacy of filter types for detecting Campylobacter jejuni and Campylobacter coli in environmental water samples by polymerase chain reaction.

    PubMed Central

    Oyofo, B A; Rollins, D M

    1993-01-01

    A previously developed polymerase chain reaction (PCR) amplification of a target region in the flaA Campylobacter flagellin gene was evaluated and adapted for use with environmental water samples. The ability to detect Campylobacter jejuni or Campylobacter coli in seeded water samples was tested with various filters after concentration and freeze-thaw lysis of the bacterial cells. A nonradioactive probe for the amplified flagellin gene fragment detected as little as 1 to 10 fg of genomic DNA and as few as 10 to 100 viable C. jejuni cells per 100 ml of water filtered onto Fluoropore (Millipore Corp.) filters. No amplification was obtained with cellulose acetate filters, most likely because of binding of the DNA to the filter. Concentration and lysis of target cells on Fluoropore and Durapore (Millipore Corp.) filters allowed PCR to be performed in the same reaction tube without removing the filters. This methodology was then adapted for use with environmental water samples. The water supply to a broiler chicken production farm was suspected as the source of C. jejuni known to be endemic in grow-out flocks at the farm, despite the inability to culture the organisms by standard methods. The filtration-PCR method detected Campylobacter DNA in more than half of the farm water samples examined. Amplified campylobacter DNA was not detected in small volumes of regional surface water samples collected on a single occasion in February. The filtration-PCR amplification method provided a basis for detection of C. jejuni and C. coli in environmental waters with a high degree of specificity and sensitivity. Images PMID:8285708

  17. The effect of simulated air conditions on N95 filtering facepiece respirators performance.

    PubMed

    Ramirez, Joel A; O'Shaughnessy, Patrick T

    2016-07-01

    The objective of this study was to determine the effect of several simulated air environmental conditions on the particle penetration and the breathing resistance of two N95 filtering facepiece respirator (FFR) models. The particle penetration and breathing resistance of the respirators were evaluated in a test system developed to mimic inhalation and exhalation breathing while relative humidity and temperature were modified. Breathing resistance was measured over 120 min using a calibrated pressure transducer under four different temperature and relative humidity conditions without aerosol loading. Particle penetration was evaluated before and after the breathing resistance test at room conditions using a sodium chloride aerosol measured with a scanning mobility particle sizer. Results demonstrated that increasing relative humidity and lowering external temperature caused significant increases in breathing resistance (p < 0.001). However, these same conditions did not influence the penetration or most penetrating particle size of the tested FFRs. The increase in breathing resistance varied by FFR model suggesting that some FFR media are less influenced by high relative humidity. PMID:26861653

  18. Review of Various Air Sampling Methods for Solvent Vapors.

    ERIC Educational Resources Information Center

    Maykoski, R. T.

    Vapors of trichloroethylene, toluene, methyl ethyl ketone, and butyl cellosolve in air were collected using Scotchpac and Tedlar bags, glass prescription bottles, and charcoal adsorption tubes. Efficiencies of collection are reported. (Author/RH)

  19. Inertial particle acceleration statistics in turbulence: Effects of filtering, biased sampling, and flow topology

    NASA Astrophysics Data System (ADS)

    Salazar, Juan P. L. C.; Collins, Lance R.

    2012-08-01

    In this study, we investigate the effect of "biased sampling," i.e., the clustering of inertial particles in regions of the flow with low vorticity, and "filtering," i.e., the tendency of inertial particles to attenuate the fluid velocity fluctuations, on the probability density function of inertial particle accelerations. In particular, we find that the concept of "biased filtering" introduced by Ayyalasomayajula et al. ["Modeling inertial particle acceleration statistics in isotropic turbulence," Phys. Fluids 20, 0945104 (2008), 10.1063/1.2976174], in which particles filter stronger acceleration events more than weaker ones, is relevant to the higher order moments of acceleration. Flow topology and its connection to acceleration is explored through invariants of the velocity-gradient, strain-rate, and rotation-rate tensors. A semi-quantitative analysis is performed where we assess the contribution of specific flow topologies to acceleration moments. Our findings show that the contributions of regions of high vorticity and low strain decrease significantly with Stokes number, a non-dimensional measure of particle inertia. The contribution from regions of low vorticity and high strain exhibits a peak at a Stokes number of approximately 0.2. Following the methodology of Ooi et al. ["A study of the evolution and characteristics of the invariants of the velocity-gradient tensor in isotropic turbulence," J. Fluid Mech. 381, 141 (1999), 10.1017/S0022112098003681], we compute mean conditional trajectories in planes formed by pairs of tensor invariants in time. Among the interesting findings is the existence of a stable focus in the plane formed by the second invariants of the strain-rate and rotation-rate tensors. Contradicting the results of Ooi et al., we find a stable focus in the plane formed by the second and third invariants of the strain-rate tensor for fluid tracers. We confirm, at an even higher Reynolds number, the conjecture of Collins and Keswani ["Reynolds

  20. Cone beam filtered backprojection (CB-FBP) image reconstruction by tracking re-sampled projection data

    NASA Astrophysics Data System (ADS)

    Tang, Xiangyang; Hsieh, Jiang; Nilsen, Roy A.; Mcolash, Scott M.

    2006-08-01

    The tomographic images reconstructed from cone beam projection data with a slice thickness larger than the nominal detector row width (namely thick image) is of practical importance in clinical CT imaging, such as neuro- and trauma- applications as well as applications for treatment planning in image guided radiation therapy. To get a balance optimization between image quality and computational efficiency, a cone beam filtered backprojection (CB-FBP) algorithm to reconstruct a thick image by tracking adaptively up-sampled cone beam projection of virtual reconstruction planes is proposed in this paper. Theoretically, a thick image is a weighted summation of a number of images with slice thickness corresponding to the nominal detector row width (namely thin image), and each thin image corresponds to a virtual reconstruction plane. To obtain the most achievable computational efficiency, the weighted summation has to be carried out in projection domain. However, it has been experimentally found that, to obtain a thick image with the reconstruction accuracy comparable to that of a thin image, the CB-FBP reconstruction algorithm has to be applied by tracking adaptively up-sampled cone beam projection data, which is the novelty of the proposed algorithm. The tracking process is carried out by making use of the cone beam projection data corresponding to the involved virtual reconstruction planes only, while the adaptive up-sampling process is implemented by interpolation along the z-direction at an adequate up-sampling rate. By using a helical body phantom, the performance of the proposed cone beam reconstruction algorithm, particularly its capability of suppressing artifacts, are experimentally evaluated and verified.

  1. Apparatus for measuring the decontamination factor of a multiple filter air-cleaning system

    DOEpatents

    Ortiz, J.P.

    1985-07-03

    An apparatus for measuring the overall decontamination factors of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement of aerosol within the apparatus.

  2. Apparatus for measuring the decontamination factor of a multiple filter air-cleaning system

    DOEpatents

    Ortiz, John P.

    1986-01-01

    An apparatus for measuring the overall decontamination factor of first and second filters located in a plenum. The first filter separates the plenum's upstream and intermediate chambers. The second filter separates the plenum's intermediate and downstream chambers. The apparatus comprises an aerosol generator that generates a challenge aerosol. An upstream collector collects unfiltered aerosol which is piped to first and second dilution stages and then to a laser aerosol spectrometer. An intermediate collector collects challenge aerosol that penetrates the first filter. The filtered aerosol is piped to the first dilution stage, diluted, and then piped to the laser aerosol spectrometer which detects single particles. A downstream collector collects challenge aerosol that penetrates both filters. The twice-filtered aerosol is piped to the aerosol spectrometer. A pump and several valves control the movement of aerosol within the apparatus.

  3. Breathing zone air sampler

    DOEpatents

    Tobin, John

    1989-01-01

    A sampling apparatus is provided which comprises a sampler for sampling air in the breathing zone of a wearer of the apparatus and a support for the sampler preferably in the form of a pair of eyeglasses. The sampler comprises a sampling assembly supported on the frame of the eyeglasses and including a pair of sample transport tubes which are suspended, in use, centrally of the frame so as to be disposed on opposite sides of the nose of the wearer and which each include an inlet therein that, in use, is disposed adjacent to a respective nostril of the nose of the wearer. A filter holder connected to sample transport tubes supports a removable filter for filtering out particulate material in the air sampled by the apparatus. The sample apparatus is connected to a pump for drawing air into the apparatus through the tube inlets so that the air passes through the filter.

  4. Application of a dry-gas meter for measuring air sample volumes in an ambient air monitoring network

    SciTech Connect

    Fritz, Brad G.

    2009-05-24

    Ambient air monitoring for non-research applications (e.g. compliance) occurs at locations throughout the world. Often, the air sampling systems employed for these purposes employee simple yet robust equipment capable of handling the rigors of demanding sampling schedules. At the Hanford Site (near Richland, Washington) concentrations of radionuclides in ambient air are monitored continuously at 44 locations. In 2004, mechanical dry-gas meters were incorporated into the Hanford Site ambient air sample collection system to allow the direct measurement of sample volumes. These meters replaced a portable airflow measurement system that required two manual flow measurements and a sample duration measurement to determine sample volume. A six-month evaluation of the dry-gas meters compared sample volumes calculated using the original flow rate method to the direct sample volume measurement (new method). The results of the evaluation indicate that use of the dry-gas meters result in accurate sample volume measurements and provide greater confidence in the measured sample volumes. In several years of in-network use, the meters have proven to be reliable and have resulted in an improved sampling system.

  5. Detection of airborne bacteria in a duck production facility with two different personal air sampling devices for an exposure assessment.

    PubMed

    Martin, Elena; Dziurowitz, Nico; Jäckel, Udo; Schäfer, Jenny

    2015-01-01

    Prevalent airborne microorganisms are not well characterized in industrial animal production buildings with respect to their quantity or quality. To investigate the work-related microbial exposure, personal bioaerosol sampling during the whole working day is recommended. Therefore, bioaerosol sampling in a duck hatchery and a duck house with two personal air sampling devices, a filter-based PGP and a NIOSH particle size separator, was performed. Subsequent, quantitative and qualitative analyses were carried out with" culture independent methods. Total cell concentrations (TCC) determined via fluorescence microscopy showed no difference between the two devices. In average, 8 × 10(6) cells/m(3) were determined in the air of the duck hatchery and 5 × 10(7) cells/m(3) in the air of the duck house. A Generated Restriction Fragment Length Polymorphism (RFLP) pattern revealed deviant bacterial compositions comparing samples collected with both devices. Clone library analyses based on 16S rRNA gene sequence analysis from the hatchery's air showed 65% similarity between the two sampling devices. Detailed 16S rRNA gene sequence analyses showed the occurrence of bacterial species like Acinetobacter baumannii, Enterococcus faecalis, Escherichia sp., and Shigella sp.; and a group of Staphylococcus delphini, S. intermedius, and S. pseudintermedius that provided the evidence of potential exposure to risk group 2 bacteria at the hatchery workplace. Size fractionated sampling with the developed by the Institute for Occupational Safety and Health of the German Social Accident Insurance (IFA) device revealed that pathogenic bacteria would deposit in the inhalable, the thorax, and possibly alveolar dust fraction according to EN481. TCC analysis showed the deposition of bacterial cells in the third stage (< 1μm) at the NIOSH device which implies that bacteria can reach deep into the lungs and contaminate the alveolus after inhalation. Nevertheless, both personal sampling devices

  6. Collection, storage, and filtration of in vivo study samples using 96-well filter plates to facilitate automated sample preparation and LC/MS/MS analysis.

    PubMed

    Berna, M; Murphy, A T; Wilken, B; Ackermann, B

    2002-03-01

    The benefits of high-throughput bioanalysis within the pharmaceutical industry are well established. One of the most significant bottlenecks in bioanalysis is transferring in vivo-generated study samples from their collection tubes during sample preparation and extraction. In most cases, the plasma samples must be stored frozen prior to analysis, and the freeze/thaw (F/T) process introduces thrombin clots that are capable of plugging pipets and automated liquid-transfer systems. A new approach to dealing with this problem involves the use of Ansys Captiva 96-well 20-microm polypropylene filter plates to collect, store frozen, and filter plasma samples prior to bioanalysis. The samples are collected from the test subjects, and the corresponding plasma samples are placed directly into the wells of the filter plate. Two Duoseal (patent pending) covers are used to seal the top and bottom of the plate, and the plate is stored at down to -70 degrees C. Prior to sample analysis, the seals are removed and the plate is placed in a 96-well SPE manifold. As the plasma thaws, it passes (by gravity or mild vacuum) through the polypropylene filter into a 96-well collection plate. A multichannel pipet or automated liquid-transfer system is used to transfer sample aliquots without fear of plugging. A significant advantage of this approach is that, unlike other methods, issues related to incomplete pipetting are virtually eliminated. The entire process is rapid since thawing and filtering take place simultaneously, and if a second F/T cycle is required for reanalysis, it is not necessary to refilter the samples (additional clotting was not observed after three F/T cycles). This technique was tested using monkey, rat, and dog plasma and sodium heparin and EDTA anticoagulants. To assess the possibility of nonspecific binding to the polypropylene filter, a variety of drug candidates from diverse drug classes were studied. Validation data generated for two Lilly compounds from distinct

  7. In-syringe magnetic stirring-assisted dispersive liquid-liquid microextraction and silylation prior gas chromatography-mass spectrometry for ultraviolet filters determination in environmental water samples.

    PubMed

    Clavijo, Sabrina; Avivar, Jessica; Suárez, Ruth; Cerdà, Víctor

    2016-04-22

    A novel online approach involving in-syringe magnetic stirring assisted dispersive liquid-liquid microextraction and derivatization coupled to gas chromatography-mass spectrometry has been developed for the determination of seven UV filters extensively used in cosmetic products in environmental water samples. The effect of parameters such as the type and volume of extraction solvent, dispersive solvent and derivatization agent, pH, ionic strength and stirring time, was studied using multivariate experimental design. Extraction, derivatization and preconcentration were simultaneously performed using acetone as dispersive solvent, N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) as derivatization agent and trichloroethylene as extraction solvent. After stirring during 160s, the sedimented phase was transferred to a rotary micro-volume injection valve (3 μL) and introduced by an air stream into the injector of the GC through a stainless-steel tube used as interface. The detection limits were in the range of 0.023-0.16 μg L(-1) and good linearity was observed up to 500 μg L(-1) of the studied UV filters, with R(2) ranging between 0.9829 and 0.9963. The inter-day precision expressed as relative standard deviation (n=5) varied between 5.5 and 16.8%. Finally, the developed method was satisfactorily applied to assess the occurrence of the studied UV filters in seawater and pool water samples. Some of the studied UV filters were found in these samples and an add-recovery test was also successfully performed with recoveries between 82 and 111%. PMID:27016119

  8. Integration of air separation membrane and coalescing filter for use on an inlet air system of an engine

    DOEpatents

    Moncelle, Michael E.

    2003-01-01

    An intake air separation system suitable for combustion air of an internal combustion engine. An air separation device of the system includes a plurality of fibers, each fiber having a tube with a permeation barrier layer on the outer surface thereof and a coalescing layer on the inner surface thereof, to restrict fluid droplets from contacting the permeation barrier layer.

  9. Rapid analytical technique to identify alpha emitting isotopes in water, air-filters, urine, and solid matrices using a Frisch Grid detector.

    PubMed

    Scarpitta, Salvatore C; Miltenberger, Robert P; Gaschott, Robert; Carte, Nina

    2003-04-01

    A 5-inch-diameter Frisch Grid gas-proportional ionization chamber was utilized at Brookhaven National Laboratory (BNL) to rapidly characterize and quantify alpha-emitting actinides in unprocessed water, soil, air-filter, urine, and solid matrices. Instrument calibrations for the various matrices were performed by spiking representative samples with National Institute of Standards and Technology traceable isotopes of 230Th, 232U, 236Pu, and 243Am. Detection efficiencies were typically 15-20% for solid matrices (soil, concrete, filters, dry urine) and 45% for mass-less water samples. Instrument background over a 512-channel alpha-energy range of 3-8 MeV is very low at 0.01 cps. At optimum efficiency, minimum detectable levels of 0.56 mBq Kg(-1), 74 mBq L(-1) and 14.8 mBq filter(-1) were achievable for 40 x 10(-6) Kg soil, 1 x 10(-3) L tap water (or urine), and 4.5 cm diameter air-filter samples, respectively, each counted for 60 min. Data and spectra are presented showing the quality of results obtained using untreated samples obtained from the BNL Graphite Research Reactor Decommissioning Project. These samples contained Bq to MBq per gram amounts of (239,240)Pu, 241Am, and/or (234,235/238)U (as well as other beta/gamma emitters). Data and spectra are also presented for a very finely pulverized and homogeneous U.S. DOE/RESL soil reference standard (spiked with 239Pu, 241Am, and 233U) that was used to assess precision, accuracy, and reproducibility. Although this technique has its limitations, the advantages are (1) minimal sample preparation, (2) no separation chemistry required, (3) no chemical or hazardous waste generated, and (4) ability to immediately characterize and quantify alpha-emitting nuclides in most matrices. The benefits of this technique to the BNL/DOE Project Managers were rapid (1-2 d) turn-around times coupled with significant cost savings, as compared to commercial off-site analyses. PMID:12705448

  10. Field evaluation of sampling and analysis for organic pollutants in indoor air. Project summary

    SciTech Connect

    Chuang, J.C.; Mack, G.A.; Stockrahm, J.W.; Hannan, S.W.; Bridges, C.

    1988-09-01

    The objectives of the study were to determine the feasibility of the use of newly developed indoor air samplers in residential indoor air sampling and to evaluate methodology for characterization of the concentrations of polynuclear aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in residential air.

  11. Rapid on-site air sampling with a needle extraction device for evaluating the indoor air environment in school facilities.

    PubMed

    Inoue, Mitsuru; Mizuguchi, Ayako; Ueta, Ikuo; Takahashi, Kazuya; Saito, Yoshihiro

    2013-01-01

    A rapid on-site air sampling technique was developed with a miniaturized needle-type sample preparation device for a systematic evaluation of the indoor air environments in school facilities. With the in-needle extraction device packed with a polymer particle of divinylbenzene and activated carbon particles, various types of volatile organic compounds (VOCs) were successfully extracted. For evaluating the indoor air qualities in school facilities, air samples in renovated rooms using organic solvent as a thinner of the paint were analyzed along with measurements of several VOCs in indoor air samples taken in newly built primary schools mainly using low-VOCs materials. After periodical renovation/maintenance, the time-variation profile of typical VOCs found in the school facilities has also been monitored. From the results, it could be observed that the VOCs in most of the rooms in these primary schools were at a quite low level; however, a relatively higher concentration of VOCs was found in some specially designed rooms, such as music rooms. In addition, some non-regulated compounds, including benzyl alcohol and branched alkanes, were detected in these primary schools. The results showed a good applicability of the needle device to indoor air analysis in schools, suggesting a wide range of future employment of the needle device, especially for indoor air analysis in other types of facilities and rooms including hospitals and hotels. PMID:23665624

  12. Extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters by supercritical carbon dioxide

    SciTech Connect

    Schilling, J.B.

    1997-09-01

    Supercritical fluid extraction (SFE) using unmodified carbon dioxide has been explored as an alternative method for the extraction of semivolatile organic compounds from high-efficiency particulate air (HEPA) filters. HEPA filters provide the final stage of containment on many exhaust systems in US Department of Energy (DOE) facilities by preventing the escape of chemical and radioactive materials entrained in the exhausted air. The efficiency of the filters is tested by the manufacturer and DOE using dioctylphthalate (DOP), a substance regulated by the US Environmental Protection Agency under the Resource Conservation and Recovery Act. Therefore, the filters must be analyzed for semivolatile organics before disposal. Ninety-eight acid, base, and neutral semivolatile organics were spiked onto blank HEPA material and extracted using SFE, Soxhlet, automated Soxhlet, and sonication techniques. The SFE conditions were optimized using a Dionex SFE-703 instrument. Average recoveries for the 98 semivolatile compounds are 82.7% for Soxhlet, 74.0% for sonication, 70.2% for SFE, and 62.9% for Soxtec. Supercritical fluid extraction reduces the extraction solvent volume to 10--15 mL, a factor of 20--30 less than Soxhlet and more than 5 times less than Soxtec and sonication. Extraction times of 30--45 min are used compared to 16--18 h for Soxhlet extraction.

  13. PM2.5 analog forecast and Kalman filter post-processing for the Community Multiscale Air Quality (CMAQ) model

    NASA Astrophysics Data System (ADS)

    Djalalova, Irina; Delle Monache, Luca; Wilczak, James

    2015-10-01

    A new post-processing method for surface particulate matter (PM2.5) predictions from the National Oceanic and Atmospheric Administration (NOAA) developmental air quality forecasting system using the Community Multiscale Air Quality (CMAQ) model is described. It includes three main components: A real-time quality control procedure for surface PM2.5 observations; Model post-processing at each observational site using historical forecast analogs and Kalman filtering; Spreading the forecast corrections from the observation locations to the entire gridded domain.

  14. Adjustable virtual pore-size filter for automated sample preparation using acoustic radiation force

    SciTech Connect

    Jung, B; Fisher, K; Ness, K; Rose, K; Mariella, R

    2008-05-22

    We present a rapid and robust size-based separation method for high throughput microfluidic devices using acoustic radiation force. We developed a finite element modeling tool to predict the two-dimensional acoustic radiation force field perpendicular to the flow direction in microfluidic devices. Here we compare the results from this model with experimental parametric studies including variations of the PZT driving frequencies and voltages as well as various particle sizes and compressidensities. These experimental parametric studies also provide insight into the development of an adjustable 'virtual' pore-size filter as well as optimal operating conditions for various microparticle sizes. We demonstrated the separation of Saccharomyces cerevisiae and MS2 bacteriophage using acoustic focusing. The acoustic radiation force did not affect the MS2 viruses, and their concentration profile remained unchanged. With optimized design of our microfluidic flow system we were able to achieve yields of > 90% for the MS2 with > 80% of the S. cerevisiae being removed in this continuous-flow sample preparation device.

  15. Analysis of pharmaceutical and other organic wastewater compounds in filtered and unfiltered water samples by gas chromatography/mass spectrometry

    USGS Publications Warehouse

    Zaugg, Steven D.; Phillips, Patrick J.; Smith, Steven G.

    2014-01-01

    Research on the effects of exposure of stream biota to complex mixtures of pharmaceuticals and other organic compounds associated with wastewater requires the development of additional analytical capabilities for these compounds in water samples. Two gas chromatography/mass spectrometry (GC/MS) analytical methods used at the U.S. Geological Survey National Water Quality Laboratory (NWQL) to analyze organic compounds associated with wastewater were adapted to include additional pharmaceutical and other organic compounds beginning in 2009. This report includes a description of method performance for 42 additional compounds for the filtered-water method (hereafter referred to as the filtered method) and 46 additional compounds for the unfiltered-water method (hereafter referred to as the unfiltered method). The method performance for the filtered method described in this report has been published for seven of these compounds; however, the addition of several other compounds to the filtered method and the addition of the compounds to the unfiltered method resulted in the need to document method performance for both of the modified methods. Most of these added compounds are pharmaceuticals or pharmaceutical degradates, although two nonpharmaceutical compounds are included in each method. The main pharmaceutical compound classes added to the two modified methods include muscle relaxants, opiates, analgesics, and sedatives. These types of compounds were added to the original filtered and unfiltered methods largely in response to the tentative identification of a wide range of pharmaceutical and other organic compounds in samples collected from wastewater-treatment plants. Filtered water samples are extracted by vacuum through disposable solid-phase cartridges that contain modified polystyrene-divinylbenzene resin. Unfiltered samples are extracted by using continuous liquid-liquid extraction with dichloromethane. The compounds of interest for filtered and unfiltered sample

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

    NASA Technical Reports Server (NTRS)

    Meyers, Valerie

    2013-01-01

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

  17. Low-cost monitoring of Campylobacter in poultry houses by air sampling and quantitative PCR.

    PubMed

    Søndergaard, M S R; Josefsen, M H; Löfström, C; Christensen, L S; Wieczorek, K; Osek, J; Hoorfar, J

    2014-02-01

    The present study describes the evaluation of a method for the quantification of Campylobacter by air sampling in poultry houses. Sampling was carried out in conventional chicken houses in Poland, in addition to a preliminary sampling in Denmark. Each measurement consisted of three air samples, two standard boot swab fecal samples, and one airborne particle count. Sampling was conducted over an 8-week period in three flocks, assessing the presence and levels of Campylobacter in boot swabs and air samples using quantitative real-time PCR. The detection limit for air sampling was approximately 100 Campylobacter cell equivalents (CCE)/m3. Airborne particle counts were used to analyze the size distribution of airborne particles (0.3 to 10 μm) in the chicken houses in relation to the level of airborne Campylobacter. No correlation was found. Using air sampling, Campylobacter was detected in the flocks right away, while boot swab samples were positive after 2 weeks. All samples collected were positive for Campylobacter from week 2 through the rest of the rearing period for both sampling techniques, although levels 1- to 2-log CCE higher were found with air sampling. At week 8, the levels were approximately 10(4) and 10(5) CCE per sample for boot swabs and air, respectively. In conclusion, using air samples combined with quantitative real-time PCR, Campylobacter contamination could be detected earlier than by boot swabs and was found to be a more convenient technique for monitoring and/or to obtain enumeration data useful for quantitative risk assessment of Campylobacter. PMID:24490929

  18. CO2 isotope analyses using large air samples collected on intercontinental flights by the CARIBIC Boeing 767.

    PubMed

    Assonov, S S; Brenninkmeijer, C A M; Koeppel, C; Röckmann, T

    2009-03-01

    Analytical details for 13C and 18O isotope analyses of atmospheric CO2 in large air samples are given. The large air samples of nominally 300 L were collected during the passenger aircraft-based atmospheric chemistry research project CARIBIC and analyzed for a large number of trace gases and isotopic composition. In the laboratory, an ultra-pure and high efficiency extraction system and high-quality isotope ratio mass spectrometry were used. Because direct comparison with other laboratories was practically impossible, the extraction and measurement procedures were tested in considerable detail. Extracted CO2 was measured twice vs. two different working reference CO2 gases of different isotopic composition. The two data sets agree well and their distributions can be used to evaluate analytical errors due to isotope measurement, ion corrections, internal calibration consistency, etc. The calibration itself is based on NBS-19 and also verified using isotope analyses on pure CO2 gases (NIST Reference Materials (RMs) and NARCIS CO2 gases). The major problem encountered could be attributed to CO2-water exchange in the air sampling cylinders. This exchange decreased over the years. To exclude artefacts due to such isotopic exchange, the data were filtered to reject negative delta18O(CO2) values. Examples of the results are given. PMID:19219897

  19. The stability of hydrogen ion and specific conductance in filtered wet-deposition samples stored at ambient temperatures

    USGS Publications Warehouse

    Gordon, J.D.; Schroder, L.J.; Morden-Moore, A. L.; Bowersox, V.C.

    1995-01-01

    Separate experiments by the U.S. Geological Survey (USGS) and the Illinois State Water Survey Central Analytical Laboratory (CAL) independently assessed the stability of hydrogen ion and specific conductance in filtered wet-deposition samples stored at ambient temperatures. The USGS experiment represented a test of sample stability under a diverse range of conditions, whereas the CAL experiment was a controlled test of sample stability. In the experiment by the USGS, a statistically significant (?? = 0.05) relation between [H+] and time was found for the composited filtered, natural, wet-deposition solution when all reported values are included in the analysis. However, if two outlying pH values most likely representing measurement error are excluded from the analysis, the change in [H+] over time was not statistically significant. In the experiment by the CAL, randomly selected samples were reanalyzed between July 1984 and February 1991. The original analysis and reanalysis pairs revealed that [H+] differences, although very small, were statistically different from zero, whereas specific-conductance differences were not. Nevertheless, the results of the CAL reanalysis project indicate there appears to be no consistent, chemically significant degradation in sample integrity with regard to [H+] and specific conductance while samples are stored at room temperature at the CAL. Based on the results of the CAL and USGS studies, short-term (45-60 day) stability of [H+] and specific conductance in natural filtered wet-deposition samples that are shipped and stored unchilled at ambient temperatures was satisfactory.

  20. NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF AIR SAMPLES FOR GC/MS ANALYSIS OF PESTICIDE AND PAH (BCO-L-27.0)

    EPA Science Inventory

    The purpose of this SOP is to describe methods for extracting and preparing an air sample consisting of a quartz fiber filter (Pallflex) and an XAD-2 cartridge for analysis of pesticides and polyaromatic hydrocarbons (PAHs). It covers the preparation of samples that are to be an...

  1. U.S.-MEXICO BORDER PROGRAM ARIZONA BORDER STUDY--STANDARD OPERATING PROCEDURE FOR EXTRACTION OF AIR SAMPLES FOR GC/MS ANALYSIS OF PESTICIDES AND PAH (BCO-L-27.0)

    EPA Science Inventory

    The purpose of this SOP is to describe methods for extracting and preparing an air sample consisting of a quartz fiber filter (Pallflex) and an XAD-2 cartridge for analysis of pesticides and polynuclear aromatic hydrocarbons (PAHs). It covers the preparation of samples that are ...

  2. Protein expression profiling by antibody array analysis with use of dried blood spot samples on filter paper.

    PubMed

    Jiang, Weidong; Mao, Ying Qing; Huang, Ruochun; Duan, Chaohui; Xi, Yun; Yang, Kai; Huang, Ruo-Pan

    2014-01-31

    Dried blood spot samples (DBSS) on filter paper offer several advantages compared to conventional serum/plasma samples: they do not require any phlebotomy or separation of blood by centrifugation; they are less invasive; they allow sample stability and shipment at room temperature; and they pose a negligible risk of infection with blood-borne viruses, such as HIV, HBV and HCV, to those who handle them. Therefore dried blood spot samples (DBSS) on filter paper can be a quick, convenient and inexpensive means of obtaining blood samples for biomarker discovery, disease screening, diagnosis and treatment monitoring in non-hospitalized, public health settings. In this study, we investigated for the first time the potential application of dried blood spot samples (DBSS) in protein expression profiling using antibody array technology. First, optimal conditions for array assay performance using dried blood spot samples (DBSS) was established, including sample elution buffer, elution time, elution temperature and assay blocking buffer. Second, we analyzed dried blood spot samples (DBSS) using three distinct antibody array platforms, including sandwich-based antibody arrays, quantitative antibody arrays and biotin-label-based antibody arrays. In comparison with paired serum samples, detection of circulating proteins in dried blood spot samples (DBSS) correlated well for both low- and high-abundance proteins on all three antibody array platforms. In conclusion, our study strongly indicates the novel application of multiplex antibody array platforms to analyze dried blood spot samples (DBSS) on filter paper represents a viable, cost-effective method for protein profiling, biomarker discovery and disease screening in a large, population-based survey. PMID:24287424

  3. DIRECT TRACE ANALYSIS OF VOLATILE ORGANIC COMPOUNDS IN AIR USING ION TRAP MASS SPECTROMETERS WITH FILTERED NOISE FIELDS

    EPA Science Inventory

    Two ion trap mass spectrometers and direct air sampling interfaces are being evaluated in the laboratory for monitoring toxic air pollutants in real time. he mass spectrometers are the large, laboratory-based Finnigan MAT ion trap (ITMS) and the compact, field-deployable Teledyne...

  4. Air filters and air cleaners: Rostrum by the American Academy of Allergy, Asthma & Immunology Indoor Allergen Committee

    PubMed Central

    Sublett, James L.; Seltzer, James; Burkhead, Robert; Williams, P. Brock; Wedner, H. James; Phipatanakul, Wanda

    2010-01-01

    The allergist is generally recognized as possessing the greatest expertise in relating airborne contaminants to respiratory health, both atopic and nonatopic. Consequently, allergists are most often asked for their professional opinions regarding the appropriate use of air-cleaning equipment. This rostrum serves as a resource for the allergist and other health care professionals seeking a better understanding of air filtration. PMID:19910039

  5. Branchfall as a Demographic Filter for Epiphyte Communities: Lessons from Forest Floor-Based Sampling

    PubMed Central

    Sarmento Cabral, Juliano; Petter, Gunnar; Mendieta-Leiva, Glenda; Wagner, Katrin; Zotz, Gerhard; Kreft, Holger

    2015-01-01

    Local variation in the abundance and richness of vascular epiphytes is often attributed to environmental characteristics such as substrate and microclimate. Less is known, however, about the impacts of tree and branch turnover on epiphyte communities. To address this issue, we surveyed branches and epiphytes found on the forest floor in 96 transects in two forests (Atlantic rainforest in Brazil and Caribbean rainforest in Panama). In the Brazilian forest, we additionally distinguished between edge and core study sites. We quantified branch abundance, epiphyte abundance, richness and proportion of adults to investigate the trends of these variables over branch diameter. Branches <2 cm in diameter comprised >90% of all branches on the forest floor. Abundance and richness of fallen epiphytes per transect were highest in the Brazilian core transects and lowest in the Panamanian transects. The majority of epiphytes on the floor (c. 65%) were found attached to branches. At all three study sites, branch abundance and branch diameter were negatively correlated, whereas epiphyte abundance and richness per branch, as well as the proportion of adults were positively correlated with branch diameter. The relationship between branch diameter and absolute epiphyte abundance or richness differed between study sites, which might be explained by differences in forest structure and dynamics. In the Panamanian forest, epiphytes had been previously inventoried, allowing an evaluation of our surveying method by comparing canopy and forest floor samplings. Individuals found on the forest floor corresponded to 13% of all individuals on branches <10 cm in diameter (including crowns), with abundance, richness and composition trends on forest floor reflecting canopy trends. We argue that forest floor surveys provide useful floristic and, most notably, demographic information particularly on epiphytes occurring on the thinnest branches, which are least accessible. Here, branchfall acts as an

  6. Branchfall as a Demographic Filter for Epiphyte Communities: Lessons from Forest Floor-Based Sampling.

    PubMed

    Sarmento Cabral, Juliano; Petter, Gunnar; Mendieta-Leiva, Glenda; Wagner, Katrin; Zotz, Gerhard; Kreft, Holger

    2015-01-01

    Local variation in the abundance and richness of vascular epiphytes is often attributed to environmental characteristics such as substrate and microclimate. Less is known, however, about the impacts of tree and branch turnover on epiphyte communities. To address this issue, we surveyed branches and epiphytes found on the forest floor in 96 transects in two forests (Atlantic rainforest in Brazil and Caribbean rainforest in Panama). In the Brazilian forest, we additionally distinguished between edge and core study sites. We quantified branch abundance, epiphyte abundance, richness and proportion of adults to investigate the trends of these variables over branch diameter. Branches <2 cm in diameter comprised >90% of all branches on the forest floor. Abundance and richness of fallen epiphytes per transect were highest in the Brazilian core transects and lowest in the Panamanian transects. The majority of epiphytes on the floor (c. 65%) were found attached to branches. At all three study sites, branch abundance and branch diameter were negatively correlated, whereas epiphyte abundance and richness per branch, as well as the proportion of adults were positively correlated with branch diameter. The relationship between branch diameter and absolute epiphyte abundance or richness differed between study sites, which might be explained by differences in forest structure and dynamics. In the Panamanian forest, epiphytes had been previously inventoried, allowing an evaluation of our surveying method by comparing canopy and forest floor samplings. Individuals found on the forest floor corresponded to 13% of all individuals on branches <10 cm in diameter (including crowns), with abundance, richness and composition trends on forest floor reflecting canopy trends. We argue that forest floor surveys provide useful floristic and, most notably, demographic information particularly on epiphytes occurring on the thinnest branches, which are least accessible. Here, branchfall acts as an

  7. Comparison of stationary and personal air sampling with an air dispersion model for children's ambient exposure to manganese.

    PubMed

    Fulk, Florence; Haynes, Erin N; Hilbert, Timothy J; Brown, David; Petersen, Dan; Reponen, Tiina

    2016-09-01

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to assess exposure for children enrolled in the Communities Actively Researching Exposure Study in Marietta, OH. Ambient air Mn concentration values were modeled using US Environmental Protection Agency's Air Dispersion Model AERMOD based on emissions from the ferromanganese refinery located in Marietta. Modeled Mn concentrations were compared with Mn concentrations from a nearby stationary air monitor. The Index of Agreement for modeled versus monitored data was 0.34 (48 h levels) and 0.79 (monthly levels). Fractional bias was 0.026 for 48 h levels and -0.019 for monthly levels. The ratio of modeled ambient air Mn to measured ambient air Mn at the annual time scale was 0.94. Modeled values were also time matched to personal air samples for 19 children. The modeled values explained a greater degree of variability in personal exposures compared with time-weighted distance from the emission source. Based on these results modeled Mn concentrations provided a suitable approach for assessing airborne Mn exposure in this cohort. PMID:27168393

  8. Detection of the Urban Release of a Bacillus anthracis Simulant by Air Sampling

    PubMed Central

    Garza, Alexander G.; Van Cuyk, Sheila M.; Brown, Michael J.

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques. PMID:24697146

  9. Detection of the urban release of a bacillus anthracis simulant by air sampling.

    PubMed

    Garza, Alexander G; Van Cuyk, Sheila M; Brown, Michael J; Omberg, Kristin M

    2014-01-01

    In 2005 and 2009, the Pentagon Force Protection Agency (PFPA) staged deliberate releases of a commercially available organic pesticide containing Bacillus amyloliquefaciens to evaluate PFPA's biothreat response protocols. In concert with, but independent of, these releases, the Department of Homeland Security sponsored experiments to evaluate the efficacy of commonly employed air and surface sampling techniques for detection of an aerosolized biological agent. High-volume air samplers were placed in the expected downwind plume, and samples were collected before, during, and after the releases. Environmental surface and personal air samples were collected in the vicinity of the high-volume air samplers hours after the plume had dispersed. The results indicate it is feasible to detect the release of a biological agent in an urban area both during and after the release of a biological agent using high-volume air and environmental sampling techniques. PMID:24697146

  10. Review of the Physical Science Facility Stack Air Sampling Probe Locations

    SciTech Connect

    Glissmeyer, John A.

    2007-09-30

    This letter report reviews compliance of the current design of the Physical Science Facility (PSF) stack air sampling locations with the ANSI/HPS N13.1-1999 standard. The review was based on performance criteria used for locating air sampling probes, the design documents provided and available information on systems previously tested for compliance with the criteria. Recommendations are presented for ways to bring the design into compliance with the requirements for the sampling probe placement.

  11. imFASP: An integrated approach combining in-situ filter-aided sample pretreatment with microwave-assisted protein digestion for fast and efficient proteome sample preparation.

    PubMed

    Zhao, Qun; Fang, Fei; Wu, Ci; Wu, Qi; Liang, Yu; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2016-03-17

    An integrated sample preparation method, termed "imFASP", which combined in-situ filter-aided sample pretreatment and microwave-assisted trypsin digestion, was developed for preparation of microgram and even nanogram amounts of complex protein samples with high efficiency in 1 h. For imFASP method, proteins dissolved in 8 M urea were loaded onto a filter device with molecular weight cut off (MWCO) as 10 kDa, followed by in-situ protein preconcentration, denaturation, reduction, alkylation, and microwave-assisted tryptic digestion. Compared with traditional in-solution sample preparation method, imFASP method generated more protein and peptide identifications (IDs) from preparation of 45 μg Escherichia coli protein sample due to the higher efficiency, and the sample preparation throughput was significantly improved by 14 times (1 h vs. 15 h). More importantly, when the starting amounts of E. coli cell lysate decreased to nanogram level (50-500 ng), the protein and peptide identified by imFASP method were improved at least 30% and 44%, compared with traditional in-solution preparation method, suggesting dramatically higher peptide recovery of imFASP method for trace amounts of complex proteome samples. All these results demonstrate that the imFASP method developed here is of high potential for high efficient and high throughput preparation of trace amounts of complex proteome samples. PMID:26920773

  12. Evaluation of sampling probes for fit testing n95 filtering facepiece respirators.

    PubMed

    Bergman, Michael S; Viscusi, Dennis J; Zhuang, Ziqing; Newcomb, William E

    2013-05-01

    Previous studies have shown a sampling probe bias for measuring fit factors (FFs) in respirator facepieces. This study was conducted to evaluate three sampling probes for fit testing NIOSH-certified N95 filtering facepiece respirators (FFRs). Two phases of fit test experiments were conducted incorporating 'side-by-side' probe mounting: (i) flush probe versus deep probe and (ii) flush probe versus disc probe. Seven test subjects in Phase 1 and six subjects in Phase 2 were fit tested with one to three N95 FFR models for a total of 10 subject/FFR model combinations for each phase. For each experimental condition, induced faceseal leakage (IFSL) through an induced leak was measured using a PORTACOUNT® Plus model 8020A Respirator Fit Tester with a model 8095 N95-Companion™ accessory. For Phase 1, the mean IFSL of all flush probe measurements (3.6%) was significantly greater than (P < 0.05) the mean IFSL of all deep probe measurements (3.3%). For Phase 2, the mean IFSL of all flush probe measurements (8.5%) was not significantly greater than (P > 0.05) the mean IFSL of all disc probe measurements (8.3%). Results indicate that some leak site and subject/FFR model/leak site combination comparisons (flush probe versus deep probe or flush probe versus disc probe) were statistically different (P < 0.05). The overall mean IFSL for subject/FFR model/leak site combinations differed by 14 and 4% for the flush probe versus deep probe and the flush probe versus disc probe, respectively; however, from a practical standpoint, there is little difference between the flush probe tests compared with the deep probe or disc probe tests. Overall, IFSL measured using the flush probe is higher (resulting in a more conservative measure of faceseal leakage) compared with either the deep probe or disc probe. The more conservative results obtained using the flush probe provide support for its common usage for fit testing cup-shaped FFRs in the USA and potential use for fit testing FFRs in

  13. Impact of HVAC filter on indoor air quality in terms of ozone removal and carbonyls generation

    NASA Astrophysics Data System (ADS)

    Lin, Chi-Chi; Chen, Hsuan-Yu

    2014-06-01

    This study aims at detecting ozone removal rates and corresponding carbonyls generated by ozone reaction with HVAC filters from various building, i.e., shopping mall, school, and office building. Studies were conducted in a small-scale environmental chamber. By examining dust properties including organic carbon proportion and specific surface area of dusts adsorbed on filters along with ozone removal rates and carbonyls generation rate, the relationship among dust properties, ozone removal rates, and carbonyls generation was identified. The results indicate a well-defined positive correlation between ozone removal efficiency and carbonyls generation on filters, as well as a positive correlation among the mass of organic carbon on filters, ozone removal efficiency and carbonyls generations.

  14. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... P-series certification is requested by the applicant. (b) Filters including holders and gaskets... and gaskets, the exhalation valves shall be blocked so as to ensure that leakage, if present, is...

  15. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... P-series certification is requested by the applicant. (b) Filters including holders and gaskets... and gaskets, the exhalation valves shall be blocked so as to ensure that leakage, if present, is...

  16. Identification of ambient air sampling and analysis methods for the 189 Title III air toxics

    SciTech Connect

    Mukund, R.; Kelly, T.J.; Gordon, S.M.; Hays, M.J.

    1994-12-31

    The state of development of ambient air measurement methods for the 189 Hazardous Air Pollution (HAPs) in Title 3 of the Clean Air Act Amendments was surveyed. Measurement methods for the HAPs were identified by reviews of established methods, and by literature searches for pertinent research techniques. Methods were segregated by their degree of development into Applicable, Likely, and Potential methods. This survey identified a total of 183 methods, applicable at varying degrees to ambient air measurements of one or more HAPs. As a basis for classifying the HAPs and evaluating the applicability of measurement methods, a survey of a variety of chemical and physical properties of the HAPs was also conducted. The results of both the methods and properties surveys were tabulated for each of the 189 HAP. The current state of development of ambient measurement methods for the 189 HAPs was then assessed from the results of the survey, and recommendations for method development initiatives were developed.

  17. Study of PCBs and PBDEs in King George Island, Antarctica, using PUF passive air sampling

    NASA Astrophysics Data System (ADS)

    Li, Yingming; Geng, Dawei; Liu, Fubin; Wang, Thanh; Wang, Pu; Zhang, Qinghua; Jiang, Guibin

    2012-05-01

    Polyurethane foam (PUF)-disk based passive air samplers were deployed in King George Island, Antarctica, during the austral summer of 2009-2010, to investigate levels, distributions and potential sources of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in Antarctic air. The atmospheric levels of ∑ indicator PCBs and ∑14 PBDEs ranged from 1.66 to 6.50 pg m-3 and from 0.67 to 2.98 pg m-3, respectively. PCBs homologue profiles were dominated by di-PCBs, tri-PCBs and tetra-PCBs, whereas BDE-17 and BDE-28 were the predominant congeners of PBDEs, which could be explained by long-range atmospheric transport processes. However, the sampling sites close to the Antarctic research stations showed higher atmospheric concentrations of PCBs and PBDEs than the other sites, reflecting potential local sources from the Antarctic research stations. The non-Aroclor congener PCB-11 was found in all the air samples, with air concentrations of 3.60-31.4 pg m-3 (average 15.2 pg m-3). Comparison between the results derived from PUF-disk passive air sampling and high-volume air sampling validates the feasibility of using the passive air samplers in Antarctic air. To our knowledge, this study is the first employment of PUF-disk based passive air samplers in Antarctic atmosphere.

  18. Summary of gamma spectrometry on local air samples from 1985--1995

    SciTech Connect

    Winn, W.G.

    1997-04-02

    This report summarizes the 1985--1995 results of low-level HPGe gamma spectrometry analysis of high-volume air samples collected at the Aiken Airport, which is about 25 miles north of SRS. The author began analyzing these samples with new calibrations using the newly developed GRABGAM code in 1985. The air sample collections were terminated in 1995, as the facilities at the Aiken Airport were no longer available. Air sample measurements prior to 1985 were conducted with a different analysis system (and by others prior to 1984), and the data were not readily available. The report serves to closeout this phase of local NTS air sample studies, while documenting the capabilities and accomplishments. Hopefully, the information will guide other applications for this technology, both locally and elsewhere.

  19. Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

    SciTech Connect

    Smith, P.R.; Gregory, W.S.

    1985-04-01

    Pressure transients in nuclear facility air cleaning systems can originate from natural phenomena such as tornadoes or from accident-induced explosive blast waves. This study was concerned with the effective efficiency of high-efficiency particulate air (HEPA) filters during pressure surges resulting from simulated tornado and explosion transients. The primary objective of the study was to examine filter efficiencies at pressure levels below the point of structural failure. Both standard and high-capacity 0.61-m by 0.61-m HEPA filters were evaluated, as were several 0.2-m by 0.2-m HEPA filters. For a particular manufacturer, the material release when subjected to tornado transients is the same (per unit area) for both the 0.2-m by 0.2-m and the 0.61-m by 0.61-m filters. For tornado transients, the material release was on the order of micrograms per square meter. When subjecting clean HEPA filters to simulated tornado transients with aerosol entrained in the pressure pulse, all filters tested showed a degradation of filter efficiency. For explosive transients, the material release from preloaded high-capacity filters was as much as 340 g. When preloaded high-capacity filters were subjected to shock waves approximately 50% of the structural limit level, 1 to 2 mg of particulate was released.

  20. Investigation into alternative sample preparation techniques for the determination of heavy metals in stationary source emission samples collected on quartz filters.

    PubMed

    Goddard, Sharon L; Brown, Richard J C

    2014-01-01

    Monitoring stationary source emissions for heavy metals generally requires the use of quartz filters to collect samples because of the high temperature and high moisture sampling environment. The documentary standard method sample preparation technique in Europe, EN 14385, uses digestion in hydrofluoric acid and nitric acid (HF/HNO3) followed by complexing with boric acid (H3BO3) prior to analysis. However, the use of this method presents a number of problems, including significant instrumental drift during analysis caused by the matrix components, often leading to instrument breakdown and downtime for repairs, as well as posing significant health and safety risks. The aim of this work was to develop an alternative sample preparation technique for emissions samples on quartz filters. The alternative techniques considered were: (i) acid digestion in a fluoroboric acid (HBF4) and HNO3 mixture and (ii) acid extraction in an aqua regia (AR) mixture (HCl and HNO3). Assessment of the effectiveness of these options included determination of interferences and signal drift, as well as validating the different methods by measurement of matrix certified reference materials (CRMs), and comparing the results obtained from real test samples and sample blanks to determine limits of detection. The results showed that the HBF4/HNO3 mixture provides the most viable alternative to the documentary standard preparation technique. PMID:25407906

  1. Investigation into Alternative Sample Preparation Techniques for the Determination of Heavy Metals in Stationary Source Emission Samples Collected on Quartz Filters

    PubMed Central

    Goddard, Sharon L.; Brown, Richard J. C.

    2014-01-01

    Monitoring stationary source emissions for heavy metals generally requires the use of quartz filters to collect samples because of the high temperature and high moisture sampling environment. The documentary standard method sample preparation technique in Europe, EN 14385, uses digestion in hydrofluoric acid and nitric acid (HF/HNO3) followed by complexing with boric acid (H3BO3) prior to analysis. However, the use of this method presents a number of problems, including significant instrumental drift during analysis caused by the matrix components, often leading to instrument breakdown and downtime for repairs, as well as posing significant health and safety risks. The aim of this work was to develop an alternative sample preparation technique for emissions samples on quartz filters. The alternative techniques considered were: (i) acid digestion in a fluoroboric acid (HBF4) and HNO3 mixture and (ii) acid extraction in an aqua regia (AR) mixture (HCl and HNO3). Assessment of the effectiveness of these options included determination of interferences and signal drift, as well as validating the different methods by measurement of matrix certified reference materials (CRMs), and comparing the results obtained from real test samples and sample blanks to determine limits of detection. The results showed that the HBF4/HNO3 mixture provides the most viable alternative to the documentary standard preparation technique. PMID:25407906

  2. Low-flow, long-term air sampling under normal domestic activity to measure house dust mite and cockroach allergens.

    PubMed

    Park, Jung Won; Kim, Cheol Woo; Kang, Dae Bong; Lee, In Young; Choi, Soo Young; Yong, Tai-Soon; Shin, Dong Cheon; Kim, Kyu Earn; Hong, Chein-Soo

    2002-01-01

    Successful applications of air sampling for the quantification of exposure to indoor allergens have been reported, but its efficiency is still controversial. We evaluated whether the low-flow, long-term air sampling in normal domestic activity conditions can quantify the exposure of house dust mites (HDM) and cockroaches (CR) allergens or not. Airborne Der f 1 and Bla g 1 were captured with a personal air sampler in 25 bedrooms during normal domestic activity. Quantification of the major allergens in the reservoir dust and the extraction of the air sampler filters were done with two-site ELISA kits. Airborne Der f 1 was measured above the threshold level of detection in 15 houses (60%). Detection rate of airborne Der f 1 was significantly higher in those houses where D. farinae was microscopically found in the reservoir dusts (76.5% vs. 25%, chi 2 = 6.0, p = 0.014). Airborne Der f 1 was more frequently detected in the houses with higher Der f 1 (> or = 10 micrograms/g dust) in bedding reservoir dust than the other group (91% vs. 35.7%, chi 2 = 7.819, p = 0.005), and the median value of airborne Der f 1 was also significantly higher in that group (14.0 pg/m3 vs. below detection limit, p = 0.002). Airborne Der f 1 was significantly correlated with Der f 1 in bedding reservoir dust (r = 0.591, p < 0.01). Airborne Bla g 1 was measured with ELISA in 16 houses (64%), and it was more frequently detected in the houses where the CRs were captured by adhesive traps (91% vs. 57%, chi 2 = 3,484, p = 0.06). The median concentration of Bla g 1 in the filter was also higher in the houses with captured CRs (0.12 vs. 0.05 mU/m3, p = 0.06), but the level of Bla g 1 did not correlate with that of the bedding dusts or the floor dusts of kitchen. These results suggested that airborne HDM or CR allergens could be measured by low-flow, long-term air sampling, and that it might be one of appropriate modalities for evaluating personal exposure to HDM and CR allergens. PMID:12926189

  3. A method to optimize sampling locations for measuring indoor air distributions

    NASA Astrophysics Data System (ADS)

    Huang, Yan; Shen, Xiong; Li, Jianmin; Li, Bingye; Duan, Ran; Lin, Chao-Hsin; Liu, Junjie; Chen, Qingyan

    2015-02-01

    Indoor air distributions, such as the distributions of air temperature, air velocity, and contaminant concentrations, are very important to occupants' health and comfort in enclosed spaces. When point data is collected for interpolation to form field distributions, the sampling locations (the locations of the point sensors) have a significant effect on time invested, labor costs and measuring accuracy on field interpolation. This investigation compared two different sampling methods: the grid method and the gradient-based method, for determining sampling locations. The two methods were applied to obtain point air parameter data in an office room and in a section of an economy-class aircraft cabin. The point data obtained was then interpolated to form field distributions by the ordinary Kriging method. Our error analysis shows that the gradient-based sampling method has 32.6% smaller error of interpolation than the grid sampling method. We acquired the function between the interpolation errors and the sampling size (the number of sampling points). According to the function, the sampling size has an optimal value and the maximum sampling size can be determined by the sensor and system errors. This study recommends the gradient-based sampling method for measuring indoor air distributions.

  4. The room temperature preservation of filtered environmental DNA samples and assimilation into a phenol-chloroform-isoamyl alcohol DNA extraction.

    PubMed

    Renshaw, Mark A; Olds, Brett P; Jerde, Christopher L; McVeigh, Margaret M; Lodge, David M

    2015-01-01

    Current research targeting filtered macrobial environmental DNA (eDNA) often relies upon cold ambient temperatures at various stages, including the transport of water samples from the field to the laboratory and the storage of water and/or filtered samples in the laboratory. This poses practical limitations for field collections in locations where refrigeration and frozen storage is difficult or where samples must be transported long distances for further processing and screening. This study demonstrates the successful preservation of eDNA at room temperature (20 °C) in two lysis buffers, CTAB and Longmire's, over a 2-week period of time. Moreover, the preserved eDNA samples were seamlessly integrated into a phenol-chloroform-isoamyl alcohol (PCI) DNA extraction protocol. The successful application of the eDNA extraction to multiple filter membrane types suggests the methods evaluated here may be broadly applied in future eDNA research. Our results also suggest that for many kinds of studies recently reported on macrobial eDNA, detection probabilities could have been increased, and at a lower cost, by utilizing the Longmire's preservation buffer with a PCI DNA extraction. PMID:24834966

  5. Evaluation of laser-induced breakdown spectroscopy (LIBS) for measurement of silica on filter samples of coal dust.

    PubMed

    Stipe, Christopher B; Miller, Arthur L; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

    2012-11-01

    Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 μg/cm(2) and 0.05 μg/cm(2), respectively (corresponding to 0.16 μg/cm(2) and 0.20 μg/cm(2) for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring. PMID:23146184

  6. The room temperature preservation of filtered environmental DNA samples and assimilation into a phenol–chloroform–isoamyl alcohol DNA extraction

    PubMed Central

    Renshaw, Mark A; Olds, Brett P; Jerde, Christopher L; McVeigh, Margaret M; Lodge, David M

    2015-01-01

    Current research targeting filtered macrobial environmental DNA (eDNA) often relies upon cold ambient temperatures at various stages, including the transport of water samples from the field to the laboratory and the storage of water and/or filtered samples in the laboratory. This poses practical limitations for field collections in locations where refrigeration and frozen storage is difficult or where samples must be transported long distances for further processing and screening. This study demonstrates the successful preservation of eDNA at room temperature (20 °C) in two lysis buffers, CTAB and Longmire's, over a 2-week period of time. Moreover, the preserved eDNA samples were seamlessly integrated into a phenol–chloroform–isoamyl alcohol (PCI) DNA extraction protocol. The successful application of the eDNA extraction to multiple filter membrane types suggests the methods evaluated here may be broadly applied in future eDNA research. Our results also suggest that for many kinds of studies recently reported on macrobial eDNA, detection probabilities could have been increased, and at a lower cost, by utilizing the Longmire's preservation buffer with a PCI DNA extraction. PMID:24834966

  7. Evaluation of Laser-Induced Breakdown Spectroscopy (LIBS) for Measurement of Silica on Filter Samples of Coal Dust

    PubMed Central

    Stipe, Christopher B.; Miller, Arthur L.; Brown, Jonathan; Guevara, Edward; Cauda, Emanuele

    2015-01-01

    Airborne silica dust (quartz) is common in coal mines and represents a respiratory hazard that can lead to silicosis, a potentially fatal lung disease. With an eye toward developing a portable monitoring device for rapid analysis of silica dust, laser-induced breakdown spectroscopy (LIBS) was used to quantify quartz in coal dust samples collected on filter media. Pure silica (Min-U-Sil™ 5), Georgia kaolin, and Pittsburgh-4 and Illinois-6 coal dusts were deposited separately and at multiple mass loadings onto 37-mm polyvinylchloride (PVC) filters. LIBS-generated silicon emission was monitored at 288.16 nm, and non-silica contributions to that signal from kaolinite were removed by simultaneously detecting aluminum. Measurements of the four samples were used to calculate limits of detection (LOD) for silicon and aluminum of approximately 0.08 µg/cm2 and 0.05 µg/cm2, respectively (corresponding to 0.16 µg/cm2 and 0.20 µg/cm2 for silica and kaolinite, respectively). Relative errors of prediction are around 10%. Results demonstrate that LIBS can dependably quantify silica on filter samples of coal dust and confirm that accurate quantification can be achieved for very lightly loaded samples, which supports the potential application of LIBS for rapid, in-field monitoring. PMID:23146184

  8. A STRINGENT COMPARISON OF SAMPLING AND ANALYSIS METHODS FOR VOCS IN AMBIENT AIR

    EPA Science Inventory

    A carefully designed study was conducted during the summer of 1998 to simultaneously collect samples of ambient air by canisters and compare the analysis results to direct sorbent preconcentration results taken at the time of sample collection. A total of 32 1-h sample sets we...

  9. A METHOD FOR THE SAMPLING AND ANALYSIS OF POLYCHLORINATED BIPHENYLS (PCBS) IN AMBIENT AIR

    EPA Science Inventory

    A method was developed for the sampling and analysis of polychlorinated biphenyls (PCBs) in air. An easily constructed, high-volume sampling system is employed with porous polyurethane foam as the collection medium. The sample is collected at the rate of 0.6 to 1.0 cu m per minut...

  10. Mixed species radioiodine air sampling readout and dose assessment system

    DOEpatents

    Distenfeld, Carl H.; Klemish, Jr., Joseph R.

    1978-01-01

    This invention provides a simple, reliable, inexpensive and portable means and method for determining the thyroid dose rate of mixed airborne species of solid and gaseous radioiodine without requiring highly skilled personnel, such as health physicists or electronics technicians. To this end, this invention provides a means and method for sampling a gas from a source of a mixed species of solid and gaseous radioiodine for collection of the mixed species and readout and assessment of the emissions therefrom by cylindrically, concentrically and annularly molding the respective species around a cylindrical passage for receiving a conventional probe-type Geiger-Mueller radiation detector.

  11. Dispersion modeling of selected PAHs in urban air: A new approach combining dispersion model with GIS and passive air sampling

    NASA Astrophysics Data System (ADS)

    Sáňka, Ondřej; Melymuk, Lisa; Čupr, Pavel; Dvorská, Alice; Klánová, Jana

    2014-10-01

    This study introduces a new combined air concentration measurement and modeling approach that we propose can be useful in medium and long term air quality assessment. A dispersion study was carried out for four high molecular weight polycyclic aromatic hydrocarbons (PAHs) in an urban area with industrial, traffic and domestic heating sources. A geographic information system (GIS) was used both for processing of input data as well as visualization of the modeling results. The outcomes of the dispersion model were compared to the results of passive air sampling (PAS). Despite discrepancies between measured and modeled concentrations, an approach combining the two techniques is promising for future air quality assessment. Differences between measured and modeled concentrations, in particular when measured values exceed the modeled concentrations, are indicative of undocumented, sporadic pollutant sources. Thus, these differences can also be useful for assessing and refining emission inventories.

  12. Automated syringe sampler. [remote sampling of air and water

    NASA Technical Reports Server (NTRS)

    Purgold, G. C. (Inventor)

    1981-01-01

    A number of sampling services are disposed in a rack which slides into a housing. In response to a signal from an antenna, the circutry elements are activated which provide power individually, collectively, or selectively to a servomechanism thereby moving an actuator arm and the attached jawed bracket supporting an evaculated tube towards a stationary needle. One open end of the needle extends through the side wall of a conduit to the interior and the other open end is maintained within the protective sleeve, supported by a bifurcated bracket. A septum in punctured by the end of the needle within the sleeve and a sample of the fluid medium in the conduit flows through the needle and is transferred to a tube. The signal to the servo is then reversed and the actuator arm moves the tube back to its original position permitting the septum to expand and seal the hole made by the needle. The jawed bracket is attached by pivot to the actuator to facilitate tube replacement.

  13. Salmonella recovery following air chilling for matched neck-skin and whole carcass sampling methodologies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The prevalence and serogroups of Salmonella recovered following air chilling were determined for both enriched neck skin and matching enriched whole carcass samples. Commercially processed and eviscerated carcasses were air chilled to 4C before removing the neck skin (8.3 g) and stomaching in 83 mL...

  14. Trapping Efficiency of 1,3-Dichloropropene Isomers by XAD-4 Sorbent Tubes for Air Sampling

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Emission monitoring is necessary to evaluate the impact of air pollutants such as soil fumigants on the environment. Quantifying fumigant emissions often involves the use of air sampling tubes filled with sorbents to trap fumigants. 1,3-dichloropropene (1,3-D) and chloropicrin (CP) are being increas...

  15. FIELD EVALUATION OF SAMPLING AND ANALYSIS FOR ORGANIC POLLUTANTS IN INDOOR AIR

    EPA Science Inventory

    The objectives of the study were to determine the feasibility of the use of newly developed indoor air samplers in residential indoor air sampling and to evaluate methodology for characterization of the concentrations of polynuclear aromatic hydrocarbons (PAH), PAH derivatives, a...

  16. Assimilation of surface and satellite observations with the Lotos-Euros air quality model and the ensemble Kalman filter technique

    NASA Astrophysics Data System (ADS)

    Eskes, H.; Curier, L.; Segers, A.

    2012-04-01

    LOTOS-EUROS is a chemistry transport model developed in the Netherlands, and is used for air quality assessments and forecasts. Operational air quality forecasts for the Netherlands concerning ozone and PM10 are made available on the RIVM webpage (http://www.lml.rivm.nl/) and are used to warn the population in case of predicted exceedances of air quality standards. Lotos-Euros is also contributing to the model-ensemble based air quality forecasts for Europe (MACC project, http://macc-raq.gmes-atmosphere.eu/index.php?op=get). Currently, the system is expanded to assimilate routine observations from European networks for ozone and PM10, as well as OMI NO2 satellite observations, based on the ensemble Kalman filter technique. This work is done in the context of the MACC project and contributes to the MACC air quality reanalyses for the years 2008 and 2009. The Ozone Monitoring Instrument (OMI) is a Dutch-Finnish instrument on the NASA EOS-Aura mission, and has a capability to detect boundary-layer NO2 with a unique resolution of about 20 km. In our contribution we will discuss the assimilation of NO2 tropospheric columns from the OMI instrument, the derivation of emissions and the changes in the emissions and concentrations over Europe for the period 2004-2010.

  17. Filter-Aided N-Glycan Separation (FANGS): A Convenient Sample Preparation Method for Mass Spectrometric N-Glycan Profiling

    PubMed Central

    2014-01-01

    We have developed a simple method for the release and isolation of glycoprotein N-glycans from whole-cell lysates using less than a million cells, for subsequent implementation with mass spectrometric analysis. Cellular protein extracts prepared using SDS solubilization were sequentially treated in a membrane filter device to ultimately release glycans enzymatically using PNGase F in the volatile buffer ammonium bicarbonate. The released glycans are recovered in the filtrate following centrifugation and typically permethylated prior to mass spectrometric analysis. We call our method “filter-aided N-glycan separation” and have successfully applied it to investigate N-glycan profiles of wild-type and mutant Chinese hamster ovary cells. This method is readily multiplexed and, because of the small numbers of cells needed, is compatible with the analysis of replicate samples to assess the true nature of glycan variability in tissue culture samples. PMID:24450425

  18. Large-scale generic test stand for testing of multiple configurations of air filters utilizing a range of particle size distributions

    NASA Astrophysics Data System (ADS)

    Giffin, Paxton K.; Parsons, Michael S.; Unz, Ronald J.; Waggoner, Charles A.

    2012-05-01

    The Institute for Clean Energy Technology (ICET) at Mississippi State University has developed a test stand capable of lifecycle testing of high efficiency particulate air filters and other filters specified in American Society of Mechanical Engineers Code on Nuclear Air and Gas Treatment (AG-1) filters. The test stand is currently equipped to test AG-1 Section FK radial flow filters, and expansion is currently underway to increase testing capabilities for other types of AG-1 filters. The test stand is capable of producing differential pressures of 12.45 kPa (50 in. w.c.) at volumetric air flow rates up to 113.3 m3/min (4000 CFM). Testing is performed at elevated and ambient conditions for temperature and relative humidity. Current testing utilizes three challenge aerosols: carbon black, alumina, and Arizona road dust (A1-Ultrafine). Each aerosol has a different mass median diameter to test loading over a wide range of particles sizes. The test stand is designed to monitor and maintain relative humidity and temperature to required specifications. Instrumentation is implemented on the upstream and downstream sections of the test stand as well as on the filter housing itself. Representative data are presented herein illustrating the test stand's capabilities. Digital images of the filter pack collected during and after testing is displayed after the representative data are discussed. In conclusion, the ICET test stand with AG-1 filter testing capabilities has been developed and hurdles such as test parameter stability and design flexibility overcome.

  19. Large-scale generic test stand for testing of multiple configurations of air filters utilizing a range of particle size distributions.

    PubMed

    Giffin, Paxton K; Parsons, Michael S; Unz, Ronald J; Waggoner, Charles A

    2012-05-01

    The Institute for Clean Energy Technology (ICET) at Mississippi State University has developed a test stand capable of lifecycle testing of high efficiency particulate air filters and other filters specified in American Society of Mechanical Engineers Code on Nuclear Air and Gas Treatment (AG-1) filters. The test stand is currently equipped to test AG-1 Section FK radial flow filters, and expansion is currently underway to increase testing capabilities for other types of AG-1 filters. The test stand is capable of producing differential pressures of 12.45 kPa (50 in. w.c.) at volumetric air flow rates up to 113.3 m(3)/min (4000 CFM). Testing is performed at elevated and ambient conditions for temperature and relative humidity. Current testing utilizes three challenge aerosols: carbon black, alumina, and Arizona road dust (A1-Ultrafine). Each aerosol has a different mass median diameter to test loading over a wide range of particles sizes. The test stand is designed to monitor and maintain relative humidity and temperature to required specifications. Instrumentation is implemented on the upstream and downstream sections of the test stand as well as on the filter housing itself. Representative data are presented herein illustrating the test stand's capabilities. Digital images of the filter pack collected during and after testing is displayed after the representative data are discussed. In conclusion, the ICET test stand with AG-1 filter testing capabilities has been developed and hurdles such as test parameter stability and design flexibility overcome. PMID:22667655

  20. Operational air sampling report. [Semiannual report], July 1--December 31, 1993

    SciTech Connect

    Lyons, C.L.

    1994-03-01

    Nevada Test Site vertical shaft and tunnel events generate beta/gamma fission products. The REECo air sampling program is designed to measure these radionuclides at various facilities supporting these events. The current testing moratorium and closure of the Decontamination Facility has decreased the scope of the program significantly. Of the 118 air samples collected in the only active tunnel complex, only one showed any airborne fission products. Tritiated water vapor concentrations were very similar to previously reported levels. The 206 air samples collected at the Area-6 decontamination bays and laundry were again well below any Derived Air Concentration calculation standard. Laboratory analyses of these samples were negative for any airborne fission products.

  1. Operational air sampling report. [Semiannual report], January 1--June 30, 1993

    SciTech Connect

    Lyons, C.L.

    1993-12-01

    Nevada Test Site vertical shaft and tunnel events generate beta/gamma fission products. This report discusses the REECo air sampling program which is designed to measure these radionuclides at various facilities supporting these events. The current testing moratorium and closure of the Decontamination Facility has decreased the scope of the program significantly. Of the 243 air samples collected in the only active tunnel complex, none showed any airborne fission products. Tritiated water vapor concentrations were very similar to previously reported levels. The 246 air samples collected at the Area-6 decontamination bays and laundry were again well below any Derived Air Concentration calculation standard. Laboratory analyses of these samples were negative for any airborne fission products.

  2. EVALUATION OF SAMPLING AND ANALYTICAL METHODOLOGY FOR POLYNUCLEAR AROMATIC COMPOUNDS IN INDOOR AIR

    EPA Science Inventory

    The objective of this project was to develop a generic sampling and analytical methodology to characterize the polynuclear aromatic hydrocarbon (PAH) concentrations in air within various microenvironments. The following three studies were performed: evaluation of analytical metho...

  3. TECHNOLOGY EVALUATION REPORT CEREX ENVIRONMENTAL SERVICES UV HOUND POINT SAMPLE AIR MONITOR

    EPA Science Inventory

    The USEPA's National Homeland Security Research Center (NHSRC) Technology Testing and Evaluation Program (TTEP) is carrying out performance tests on homeland security technologies. Under TTEP, Battelle evaluated the performance of the Cerex UV Hound point sample air monitor in de...

  4. NEW APPLICATION OF PASSIVE SAMPLING DEVICES FOR ASSESSMENT OF RESPIRATORY EXPOSURE TO PESTICIDES IN INDOOR AIR

    EPA Science Inventory

    The United States Environmental Protection Agency (EPA) has long maintained an interest in potential applications of passive sampling devices (PSDs) for estimating the concentrations of various pollutants in air. Typically PSDs were designed for the workplace monitoring of vola...

  5. Comparison of stationary and personal air sampling with an air dispersion model for children’s ambient exposure to manganese

    EPA Science Inventory

    Manganese (Mn) is ubiquitous in the environment and essential for normal growth and development, yet excessive exposure can lead to impairments in neurological function. This study modeled ambient Mn concentrations as an alternative to stationary and personal air sampling to asse...

  6. Application of a high-efficiency cabin air filter for simultaneous mitigation of ultrafine particle and carbon dioxide exposures inside passenger vehicles.

    PubMed

    Lee, Eon S; Zhu, Yifang

    2014-02-18

    Modern passenger vehicles are commonly equipped with cabin air filters but their filtration efficiency for ultrafine particle (UFP) is rather low. Although setting the vehicle ventilation system to recirculation (RC) mode can reduce in-cabin UFPs by ∼ 90%, passenger-exhaled carbon dioxide (CO2) can quickly accumulate inside the cabin. Using outdoor air (OA) mode instead can provide sufficient air exchange to prevent CO2 buildup, but in-cabin UFP concentrations would increase. To overcome this dilemma, we developed a simultaneous mitigation method for UFP and CO2 using high-efficiency cabin air (HECA) filtration in OA mode. Concentrations of UFP and other air pollutants were simultaneously monitored in and out of 12 different vehicles under 3 driving conditions: stationary, on local roadways, and on freeways. Under each experimental condition, data were collected with no filter, in-use original equipment manufacturer (OEM) filter, and two types of HECA filters. The HECA filters offered an average in-cabin UFP reduction of 93%, much higher than the OEM filters (∼ 50% on average). Throughout the measurements, the in-cabin CO2 concentration remained in the range of 620-930 ppm, significantly lower than the typical level of 2500-4000 ppm observed in the RC mode. PMID:24471775

  7. 42 CFR 84.181 - Non-powered air-purifying particulate filter efficiency level determination.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

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

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

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

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  10. Stereoisomer composition of the chiral UV filter 4-methylbenzylidene camphor in environmental samples.

    PubMed

    Buser, Hans-Rudolf; Müller, Markus D; Balmer, Marianne E; Poiger, Thomas; Buerge, Ignaz J

    2005-05-01

    4-Methylbenzylidene camphor (4-MBC) is an important organic UV filter used in many personal care products such as sunscreens and cosmetics. After use, 4-MBC may enter the aquatic environment due to its release from skin during recreational activities (swimming, bathing) and from personal hygiene measures (washing, laundering of cloths) via wastewater treatment plants (WWTPs). In fact, 4-MBC has been detected in wastewater, in surface waters, and even in fish. 4-MBC can exist as distinct cis-(Z)- and trans-(E)-isomers, both of which are chiral. Despite the fact that stereoisomers often show a different biological behavior, the stereochemistry of 4-MBC has hardly ever been considered in environmental or biological studies. In this study, enantioselective gas chromatography-mass spectrometry (GC-MS) was used to determine the stereoisomer composition of 4-MBC. For stereoisomer assignment, the pure enantiomers of (E)-4-MBC were synthesized from (+)- and (-)-camphor. The photochemical isomerization (sunlight) of these (E)-isomers to the corresponding (Z)-isomers eventually allowed the configurational assignment of all four stereoisomers of 4-MBC. In a technical material and in a major brand sun lotion, 4-MBC was shown to consist entirely (>99%) of (E)-isomers and to be racemic (R/S, 1.00 +/- 0.02). Wastewater showed the presence of both (E)- and (Z)-4-MBC with a clear excess of (E)-isomers (E > Z). Untreated wastewater showed a nearly racemic composition (R/S= 0.95-1.09), suggesting that most if not all commercial 4-MBC is racemic. Treated wastewater indicated some excess of (R)- or (S)-stereoisomers (R/S, 0.89-1.17), likely as a result of some enantioselective (bio)degradation in WWTPs. Residues of 4-MBC in lakes and in a river with inputs from WWTPs and/or recreational activities consisted mainly of (E)-4-MBC and, with exception of one lake (Greifensee), showed a small enantiomer excess (R/S, 1.04-1.16). In Greifensee, 4-MBC showed a higher enantiomer excess (R/S, 1

  11. A fast image retrieval method based on SVM and imbalanced samples in filtering multimedia message spam

    NASA Astrophysics Data System (ADS)

    Chen, Zhang; Peng, Zhenming; Peng, Lingbing; Liao, Dongyi; He, Xin

    2011-11-01

    With the swift and violent development of the Multimedia Messaging Service (MMS), it becomes an urgent task to filter the Multimedia Message (MM) spam effectively in real-time. For the fact that most MMs contain images or videos, a method based on retrieving images is given in this paper for filtering MM spam. The detection method used in this paper is a combination of skin-color detection, texture detection, and face detection, and the classifier for this imbalanced problem is a very fast multi-classification combining Support vector machine (SVM) with unilateral binary decision tree. The experiments on 3 test sets show that the proposed method is effective, with the interception rate up to 60% and the average detection time for each image less than 1 second.

  12. Ground-based air-sampling measurements near the Nevada Test Site after atmospheric nuclear tests.

    PubMed

    Cederwall, R T; Ricker, Y E; Cederwall, P L; Homan, D N; Anspaugh, L R

    1990-11-01

    Historical air-sampling data measured within 320 km (200 mi) of the Nevada Test Site (NTS) have been reviewed for periods following atmospheric nuclear tests, primarily in the 1950s. These data come mostly from high-volume air samplers, with some from cascade-impactor samplers. Measurements considered here are for beta radiation from gross fission products. The resulting air-quality data base is comprised of almost 13,000 samples from 42 sampling locations downwind of the NTS. In order to compile an accurate air-quality data base for use in estimating exposure via inhalation, raw data values were sought where possible, and the required calculations were performed on a computer with state-of-the-art algorithms. The data-processing procedures consisted of (1) entry and error checking of historical data; (2) determination of appropriate background values, air-sampling volumes, and net air concentrations; and (3) calculation of integrated air concentration (C) for each sample (considering fallout arrival times). Comparing C values for collocated high-volume and cascade-impactor samplers during the Upshot-Knothole series showed similar lognormal distributions, but with a geometric mean C for cascade impactors about half that for the high-volume air samplers. Overall, the uncertainty in C values is about a factor of three. In the past, it has been assumed that C could be related to ground deposition by a constant having units of velocity. In our data bases, simultaneous measurements of air concentration and ground deposition at the same locations were not related by a constant; indeed, there was a great amount of scatter. This suggests that the relationship between C and ground deposition in this situation is too complex to be treated adequately by simple approaches. PMID:2211113

  13. Ground-based air-sampling measurements near the Nevada Test Site after atmospheric nuclear tests

    SciTech Connect

    Cederwall, R.T.; Ricker, Y.E.; Cederwall, P.L.; Homan, D.N.; Anspaugh, L.R. )

    1990-11-01

    Historical air-sampling data measured within 320 km (200 mi) of the Nevada Test Site (NTS) have been reviewed for periods following atmospheric nuclear tests, primarily in the 1950s. These data come mostly from high-volume air samplers, with some from cascade-impactor samplers. Measurements considered here are for beta radiation from gross fission products. The resulting air-quality data base is comprised of almost 13,000 samples from 42 sampling locations downwind of the NTS. In order to compile an accurate air-quality data base for use in estimating exposure via inhalation, raw data values were sought where possible, and the required calculations were performed on a computer with state-of-the-art algorithms. The data-processing procedures consisted of (1) entry and error checking of historical data; (2) determination of appropriate background values, air-sampling volumes, and net air concentrations; and (3) calculation of integrated air concentration (C) for each sample (considering fallout arrival times). Comparing C values for collocated high-volume and cascade-impactor samplers during the Upshot-Knothole series showed similar lognormal distributions, but with a geometric mean C for cascade impactors about half that for the high-volume air samplers. Overall, the uncertainty in C values is about a factor of three. In the past, it has been assumed that C could be related to ground deposition by a constant having units of velocity. In our data bases, simultaneous measurements of air concentration and ground deposition at the same locations were not related by a constant; indeed, there was a great amount of scatter. This suggests that the relationship between C and ground deposition in this situation is too complex to be treated adequately by simple approaches.

  14. Microbial counts and particulate matter levels in roadside air samples under skytrain stations, Bangkok, Thailand.

    PubMed

    Luksamijarulkul, Pipat; Kongtip, Pornpimol

    2010-05-01

    In conditions with heavy traffic and crowds of people on roadside areas under skytrain stations in Bangkok, the natural air ventilation may be insufficient and air quality may be poor. A study of 350 air samples collected from the roadside, under skytrain stations in Bangkok, was carried out to assess microbial counts (210 air samples) and particulate matter (PM10) levels (140 samples). The results reveal the mean +/- standard deviation bacterial counts and fungal counts were 406.8 +/- 302.7 cfu/m3 and 128.9 +/- 89.7 cfu/m3, respectively. The PM10 level was 186.1 +/- 188.1 microg/m3. When compared to recommended levels, 4.8% of air samples (10/210 samples) had bacterial counts more than recommended levels (> 1,000 cfu/ m3) and 27.1% (38/140 samples) had PM10 levels more than recommended levels (> 120 microg/m3). These may affect human health, especially of street venders who spend most of their working time in these areas. PMID:20578558

  15. Development of a multicopter-carried whole air sampling apparatus and its applications in environmental studies.

    PubMed

    Chang, Chih-Chung; Wang, Jia-Lin; Chang, Chih-Yuan; Liang, Mao-Chang; Lin, Ming-Ren

    2016-02-01

    To advance the capabilities of probing chemical composition aloft, we designed a lightweight remote-controlled whole air sampling component (WASC) and integrated it into a multicopter drone with agile maneuverability to perform aerial whole air sampling. A field mission hovering over an exhaust shaft of a roadway tunnel to collect air samples was performed to demonstrate the applicability of the multicopter-carried WASC apparatus. Ten aerial air samples surrounding the shaft vent were collected by the multicopter-carried WASC. Additional five samples were collected manually inside the shaft for comparison. These samples were then analyzed in the laboratory for the chemical composition of 109 volatile organic compounds (VOCs), CH4, CO, CO2, or CO2 isotopologues. Most of the VOCs in the upwind samples (the least affected by shaft exhaust) were low in concentrations (5.9 ppbv for total 109 VOCs), posting a strong contrast to those in the shaft exhaust (235.8 ppbv for total 109 VOCs). By comparing the aerial samples with the in-shaft samples for chemical compositions, the influence of the shaft exhaust on the surrounding natural air was estimated. Through the aerial measurements, three major advantages of the multicopter-carried WASC were demonstrated: 1. The highly maneuverable multicopter-carried WASC can be readily deployed for three-dimensional environmental studies at a local scale (0-1.5 km); 2. Aerial sampling with superior sample integrity and preservation conditions can now be performed with ease; and 3. Data with spatial resolution for a large array of gaseous species with high precision can be easily obtained. PMID:26386435

  16. Marine Technician's Handbook, Instructions for Taking Air Samples on Board Ship: Carbon Dioxide Project.

    ERIC Educational Resources Information Center

    Keeling, Charles D.

    This booklet is one of a series intended to provide explicit instructions for the collection of oceanographic data and samples at sea. The methods and procedures described have been used by the Scripps Institution of Oceanography and found reliable and up-to-date. Instructions are given for taking air samples on board ship to determine the…

  17. 30 CFR 90.205 - Approved sampling devices; operation; air flowrate.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Approved sampling devices; operation; air flowrate. 90.205 Section 90.205 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY AND HEALTH MANDATORY HEALTH STANDARDS-COAL MINERS WHO HAVE EVIDENCE OF THE DEVELOPMENT OF PNEUMOCONIOSIS Sampling Procedures §...

  18. DEVELOPMENT OF A SUB-SLAB AIR SAMPLING PROTOCOL TO SUPPORT ASSESSMENT OF VAPOR INTRUSION

    EPA Science Inventory

    The primary purpose of this research effort is to develop a methodology for sub-slab sampling to support the EPA guidance and vapor intrusion investigations after vapor intrusion has been established at a site. Methodologies for sub-slab air sampling are currently lacking in ref...

  19. Report on sampling and analysis of ambient air at the central waste complex

    SciTech Connect

    Stauffer, M., Fluor Daniel Hanford

    1997-02-13

    Over 160 ambient indoor air samples were collected from warehouses at the Central Waste Complex used for the storage of low- level radioactive and mixed wastes. These grab (SUMMA) samples were analyzed by gas chromatography-mass spectrometry using a modified EPA TO-14 procedure. The data from this survey suggest that several buildings had elevated concentrations of volatile organic compounds.

  20. Biofiltration of toluene-contaminated air using an agro by-product-based filter bed.

    PubMed

    Krishnakumar, B; Hima, A M; Haridas, Ajit

    2007-02-01

    An innovative, coir-pith-based, filter bed for degrading vapor phase toluene in a gas biofilter over 160 days without any external nutrient supply is reported in this study. Indigenous microflora present in the coir pith as well as in the aerobic sludge added at the start-up stage metabolized the toluene, and correspondingly, CO(2) was produced in the biofilter. Inlet toluene concentration in the range of 0.75 to 2.63 g/m(3) was supplied to the biofilter in short acclimation periods. The maximum elimination capacity achieved was 96.75 g/m(3) x h at 120.72 g/m(3) x h loading where around 60% was recovered as CO(2). The filter bed maintained a stable low-pressure drop (0-4 mm H(2)O), neutral pH range (6.5-7.5), and moisture content of 60-80% (w/w) throughout the period. In addition to toluene-degrading microbial community, a grazing fauna including rotifer, bacteriovoric nematode, tardigrade, and fly larvae were also present in the filter bed. The overall performance of the biofilter bed in pollutant removal and sustainability was analyzed in this study. PMID:17024468

  1. External calibration strategy for trace element quantification in botanical samples by LA-ICP-MS using filter paper.

    PubMed

    Nunes, Matheus A G; Voss, Mônica; Corazza, Gabriela; Flores, Erico M M; Dressler, Valderi L

    2016-01-28

    The use of reference solutions dispersed on filter paper discs is proposed for the first time as an external calibration strategy for matrix matching and determination of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, Sr, V and Zn in plants by laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS). The procedure is based on the use of filter paper discs as support for aqueous reference solutions, which are further evaporated, resulting in solid standards with concentrations up to 250 μg g(-1) of each element. The use of filter paper for calibration is proposed as matrix matched standards due to the similarities of this material with botanical samples, regarding to carbon concentration and its distribution through both matrices. These characteristics allowed the use of (13)C as internal standard (IS) during the analysis by LA-ICP-MS. In this way, parameters as analyte signal normalization with (13)C, carrier gas flow rate, laser energy, spot size, and calibration range were monitored. The calibration procedure using solution deposition on filter paper discs resulted in precision improvement when (13)C was used as IS. The method precision was calculated by the analysis of a certified reference material (CRM) of botanical matrix, considering the RSD obtained for 5 line scans and was lower than 20%. Accuracy of LA-ICP-MS determinations were evaluated by analysis of four CRM pellets of botanical composition, as well as by comparison with results obtained by ICP-MS using solution nebulization after microwave assisted digestion. Plant samples of unknown elemental composition were analyzed by the proposed LA method and good agreement were obtained with results of solution analysis. Limits of detection (LOD) established for LA-ICP-MS were obtained by the ablation of 10 lines on the filter paper disc containing 40 μL of 5% HNO3 (v v(-1)) as calibration blank. Values ranged from 0.05 to 0.81  μg g(-1). Overall, the use of filter paper as support for dried aqueous

  2. NHEXAS PHASE I MARYLAND STUDY--STANDARD OPERATING PROCEDURE FOR PREPARATION OF EXPOSURE MEDIA (PUFS AND QUARTZ FIBER FILTERS) FOR AIR SAMPLERS FOR PESTICIDE AND PAH COLLECTION (L09)

    EPA Science Inventory

    This procedure describes preparation and disassembly of polyurethane foam (PUF) samplers, preparation and cleaning of filters and PUF plugs, assembly and packaging of samplers, and disassembly of exposed samplers and handling of exposed plugs and filters. Keywords: air; pestici...

  3. A Cryosampler Payload for Aseptic Air Sample Collection at Stratospheric Altitudes Using Balloons.

    NASA Astrophysics Data System (ADS)

    Sreenivasan, S.; Dutt, C. B. S.; Bhargava, P.; Shivaji, S.; Manchanda, R. K.

    A balloon borne Astrobiology program is being conducted from the National Balloon Facility of the Tata Institute of Fundamental Research at Hyderabad India in which a liquid Neon cooled cryo pump collects air samples under sterile conditions in the altitude regime 19 - 41 Km Pursuant to the encouraging results obtained from an earlier experiment conducted on January 2001 a new payload was configured and the balloon flight was conducted on April 20 2005 after implementing much more rigorous and enhanced sterilization protocol to completely rule out contamination from ground Air samples were collected in the altitude region 20 - 41 Km and are under analysis in the National laboratories in India for detecting the presence of living microbial cells In this paper we discuss the design and fabrication of the air sample collection probes the stringent sterilization protocol evolved for ensuring that the probes are aseptic before the commencement of the experiment and the sample retrival methods for analysis in the laboratory

  4. AmpliconDuo: A Split-Sample Filtering Protocol for High-Throughput Amplicon Sequencing of Microbial Communities

    PubMed Central

    Lange, Anja; Jost, Steffen; Heider, Dominik; Bock, Christina; Budeus, Bettina; Schilling, Elmar; Strittmatter, Axel; Boenigk, Jens; Hoffmann, Daniel

    2015-01-01

    High throughput sequencing (HTSeq) of small ribosomal subunit amplicons has the potential for a comprehensive characterization of microbial community compositions, down to rare species. However, the error-prone nature of the multi-step experimental process requires that the resulting raw sequences are subjected to quality control procedures. These procedures often involve an abundance cutoff for rare sequences or clustering of sequences, both of which limit genetic resolution. Here we propose a simple experimental protocol that retains the high genetic resolution granted by HTSeq methods while effectively removing many low abundance sequences that are likely due to PCR and sequencing errors. According to this protocol, we split samples and submit both halves to independent PCR and sequencing runs. The resulting sequence data is graphically and quantitatively characterized by the discordance between the two experimental branches, allowing for a quick identification of problematic samples. Further, we discard sequences that are not found in both branches (“AmpliconDuo filter”). We show that the majority of sequences removed in this way, mostly low abundance but also some higher abundance sequences, show features expected from random modifications of true sequences as introduced by PCR and sequencing errors. On the other hand, the filter retains many low abundance sequences observed in both branches and thus provides a more reliable census of the rare biosphere. We find that the AmpliconDuo filter increases biological resolution as it increases apparent community similarity between biologically similar communities, while it does not affect apparent community similarities between biologically dissimilar communities. The filter does not distort overall apparent community compositions. Finally, we quantitatively explain the effect of the AmpliconDuo filter by a simple mathematical model. PMID:26523925

  5. In Vitro Exposures in Diesel Exhaust Atmospheres: Resuspension of PM from Filters Verses Direct Deposition of PM from Air

    PubMed Central

    Lichtveld, Kim M.; Ebersviller, Seth M.; Sexton, Kenneth G.; Vizuete, William; Jaspers, Ilona; Jeffries, Harvey E.

    2012-01-01

    One of the most widely used in vitro particulate matter (PM) exposures methods is the collection of PM on filters, followed by resuspension in a liquid medium, with subsequent addition onto a cell culture. To avoid disruption of equilibria between gases and PM, we have developed a direct in vitro sampling and exposure method (DSEM) capable of PM-only exposures. We hypothesize that the separation of phases and post-treatment of filter-collected PM significantly modifies the toxicity of the PM compared to direct deposition, resulting in a distorted view of the potential PM health effects. Controlled test environments were created in a chamber that combined diesel exhaust with an urban-like mixture. The complex mixture was analyzed using both the DSEM and concurrently-collected filter samples. The DSEM showed that PM from test atmospheres produced significant inflammatory response, while the resuspension exposures at the same exposure concentration did not. Increasing the concentration of resuspended PM sixteen times was required to yield measurable IL-8 expression. Chemical analysis of the resuspended PM indicated a total absence of carbonyl compounds compared to the test atmosphere during the direct-exposures. Therefore, collection and resuspension of PM into liquid modifies its toxicity and likely leads to underestimating toxicity. PMID:22834915

  6. Assessing the Impact of Water Filters and Improved Cook Stoves on Drinking Water Quality and Household Air Pollution: A Randomised Controlled Trial in Rwanda

    PubMed Central

    Rosa, Ghislaine; Majorin, Fiona; Boisson, Sophie; Barstow, Christina; Johnson, Michael; Kirby, Miles; Ngabo, Fidele; Thomas, Evan; Clasen, Thomas

    2014-01-01

    Diarrhoea and respiratory infections remain the biggest killers of children under 5 years in developing countries. We conducted a 5-month household randomised controlled trial among 566 households in rural Rwanda to assess uptake, compliance and impact on environmental exposures of a combined intervention delivering high-performance water filters and improved stoves for free. Compliance was measured monthly by self-report and spot-check observations. Semi-continuous 24-h PM2.5 monitoring of the cooking area was conducted in a random subsample of 121 households to assess household air pollution, while samples of drinking water from all households were collected monthly to assess the levels of thermotolerant coliforms. Adoption was generally high, with most householders reporting the filters as their primary source of drinking water and the intervention stoves as their primary cooking stove. However, some householders continued to drink untreated water and most continued to cook on traditional stoves. The intervention was associated with a 97.5% reduction in mean faecal indicator bacteria (Williams means 0.5 vs. 20.2 TTC/100 mL, p<0.001) and a median reduction of 48% of 24-h PM2.5 concentrations in the cooking area (p = 0.005). Further studies to increase compliance should be undertaken to better inform large-scale interventions. Trial registration: Clinicaltrials.gov; NCT01882777; http://clinicaltrials.gov/ct2/results?term=NCT01882777&Search=Search PMID:24614750

  7. Survey of volatile organic compounds found in indoor and outdoor air samples from Japan.

    PubMed

    Tanaka-Kagawa, Toshiko; Uchiyama, Shigehisa; Matsushima, Erika; Sasaki, Akira; Kobayashi, Hiroshi; Kobayashi, Hiromi; Yagi, Masahiro; Tsuno, Masahiko; Arao, Masa; Ikemoto, Kazumi; Yamasaki, Makoto; Nakashima, Ayako; Shimizu, Yuri; Otsubo, Yasufumi; Ando, Masanori; Jinno, Hideto; Tokunaga, Hiroshi

    2005-01-01

    Indoor air quality is currently a growing concern, mainly due to the incidence of sick building syndrome and building related illness. To better understand indoor air quality in Japan, both indoor and outdoor air samples were collected from 50 residences in Iwate, Yamanashi, Shiga, Hyogo, Kochi and Fukuoka Prefectures. More than 100 volatile organic compounds (VOCs) were analyzed by thermal desorption-gas chromatography/mass spectrometry method. The most abundant class of compounds present in the indoor air samples were identified (i.e. alkanes, alkylbenzenes and terpenes). For 30% of the indoor air samples, the sum of each VOC exceeded the current provisional guideline value for total VOC (TVOC, 400 microg/m3). The major component of these samples included linear and branched-chain alkanes (possibly derived from fossil fuels), 1,4-dichlorobenzene (a moth repellent), alpha-pinene (emission from woody building materials) and limonene (probably derived from aroma products). As an unexpected result, one residence was polluted with an extremely high concentration of 1,1,1,2-tetrafluoroethane (720 microg/m3), suggesting accidental leakage from a household appliance such as a refrigerator. The results presented in this paper are important in establishing the Japanese target compound list for TVOC analysis, as well as defining the current status of indoor air quality in Japan. PMID:16541748

  8. Laboratory validation and field verification of a new passive colorimetric air monitoring badge for sampling hydrogen sulfide in air.

    PubMed

    Kring, E V; Damrell, D J; Henry, T J; DeMoor, H M; Basilio, A N; Simon, C E

    1984-01-01

    The Pro-Tek passive colorimetric air monitoring badge for personal or area sampling of hydrogen sulfide is described. The badge has been validated over the range of 1.8 to 164 ppm-hours (0.23-21 ppm on an 8-hour TWA basis). It has an overall accuracy throughout this range of +/- 15.9% and meets the NIOSH accuracy criteria for an analytical and sampling method. The colorimetric analytical method used is based on the Texas Air Control Board's Molybdenum Blue method. Color-activated exposed badge solutions are read out on a standard laboratory spectrophotometer using 1 centimeter (10 mm) cells. Variations in exposure temperature (between 10 degrees and 40 degrees C), relative humidity, and face velocity (between 2 and 250 ft/min) do not affect badge performance. Unexposed badges are stable for more than 12 months refrigerated and for two months at room temperature. PMID:6702591

  9. SAMPLING AND ANALYSIS OF PCDDS AND PCDFS IN STATIONARY SOURCE EMISSION AIR SAMPLES

    EPA Science Inventory

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs) are two classes of extremely toxic compounds produced and emitted into the environment as a result of combustion processes. lthough no standard method for sampling or analysis of PCDDs and PCDFs ...

  10. Earth formation sampling and testing method and apparatus with improved filter means

    SciTech Connect

    Carroll, J.F.

    1990-08-28

    This patent describes a method for obtaining samples of connate fluids from formations traversed by a borehole. Also described is an apparatus for collecting samples of connate fluids from earth formations traversed by a borehole.

  11. Determination of radiocarbon in stratospheric CO2, obtained through AirCore sampling.

    NASA Astrophysics Data System (ADS)

    Paul, Dipayan; Chen, Huilin; Been, Henk A.; Kivi, Rigel; Meijer, Harro A. J.

    2016-04-01

    The concentration of Greenhouse Gases (GHG), with carbon dioxide as the most prominent example, has been and still is increasing, predominantly due to emissions from fossil fuel combustion. CO2 is also the most important component of the global carbon cycle. Among other tracers, radiocarbon (Carbon-14) is a unique and an important atmospheric tracer used in the understanding of the global carbon cycle. Radiocarbon is a naturally occurring isotope (radioactive, t 1/2 = 5730 ± 40 years) of carbon produced through the interaction of thermalized neutrons and nitrogen in the upper atmosphere. Generally, for performing atmospheric radiocarbon measurements in the higher atmosphere, large samples (few liters of air) were collected using aircrafts and balloons. However, collecting stratospheric samples on a regular basis for radiocarbon analysis is extremely expensive. Here we describe the determination of radiocarbon concentrations in stratospheric CO2, collected using AirCore sampling. AirCore is an innovative sampling technique for obtaining vertical atmospheric profiles and, in Europe, is done on a regular basis at Sodankylä, Finland for CO2, CH4 and CO. The stratospheric parts of two such AirCore profiles were used in this study as a proof-of-principle. CO2 from the stratospheric air samples were extracted and converted to elemental carbon, which were then measured at the Accelerator Mass Spectrometric (AMS) facility of the Centre for Isotope Research (CIO) at the University of Groningen. The stratospheric part of the AirCore profile was divided into six sections, each contained approximately 10 μg C. A detailed description of the extraction, graphitization, AMS analysis and the derivation of the stratospheric radiocarbon profile will be the main focus. Through our results, we will show that AirCore is a viable sampling method for performing high-precision radiocarbon measurements of stratospheric CO2 with reasonably good spatial resolution on a regular basis

  12. Comparison of mold concentrations quantified by MSQPCR in indoor and outdoor air sampled simultaneously

    SciTech Connect

    Meklin, Teija; Reponen, Tina; McKinstry, Craig A.; Cho, Seung H.; Grinshpun, Sergey A.; Nevalainen, Aino; Vepsalainen, Asko; Haugland, Richard A.; Lemasters, Grace; Vesper, Sephen J.

    2007-08-15

    Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of 36 mold species in dust and in indoor and in outdoor air samples that were taken simultaneously in 17 homes in Cincinnati with no-known water damage. The total spore concentrations in the indoor (I) and outdoor (O) air samples were statistically significantly different and the concentrations in the three sample types of many of the individual species were significantly different (p < 0.05 based on the Wilcoxon Signed Rank Test). The I/O ratios of the averages or geometric means of the individual species were generally less than 1; but these I/O ratios were quite variable ranging from 0.03 for A. sydowii to 1.2 for Acremonium strictum. There were no significant correlations for the 36 specific mold concentrations between the dust samples and the indoor or outdoor air samples (based on the Spearman’s Rho test). The indoor and outdoor air concentrations of 32 of the species were not correlated. Only Aspergillus penicillioides, C. cladosporioides types 1 and 2 and C. herbarum had sufficient data to estimate a correlation at rho > 0.5 with signicance (p < 0.05) In six of these homes, a previous dust sample had been collected and analyzed 2 years earlier. The ERMI© values for the dust samples taken in the same home two years apart were not significantly different (p=0.22) based on Wilcoxon Signed Rank Test.

  13. Pesticide detection in air samples from contrasted houses and in their inhabitants' hair.

    PubMed

    Raeppel, Caroline; Salquèbre, Guillaume; Millet, Maurice; Appenzeller, Brice M R

    2016-02-15

    In order to identify associations between indoor air contamination and human exposure to pesticides, hair samples from 14 persons (9 adults and 5 children below 12 years) were collected simultaneously with the air of their 5 contrasted houses. Three houses were situated in Alsace (France), one in Lorraine (France) and one in Luxembourg (Luxembourg). Houses were located in urban (n=3), semi-urban (n=1) and rural areas (n=1). Twenty five (25) pesticides were detected at least once in indoor air samples and 20 pesticides were detected at least once in hair samples. The comparison between hair and air samples for the same sampling periods shows that pesticides detected in the two matrices were not necessarily associated. Exposure profiles varied from one home to another but also between inhabitants of the same home, suggesting that exposure can be different between inhabitants of the same home. This study demonstrated the usefulness and the complementarity of hair analysis, for the personalized biomonitoring of people exposure to pesticides, and air analysis, for the identification of airborne exposure and house contamination. PMID:26706757

  14. Field evaluation of sampling and analysis for organic pollutants in indoor air

    SciTech Connect

    Chuang, J.C.; Mack, G.A.; Stockrahm, J.W.; Hannan, S.W.; Bridges, C.

    1988-08-01

    The objectives of the study were to determine the feasibility of the use of newly developed indoor air samplers in residential indoor air sampling and to evaluate methodology for characterization of the concentrations of polynuclear aromatic hydrocarbons (PAH), PAH derivatives, and nicotine in residential air. Residential air sampling was conducted in Columbus, Ohio during the winter of 1986/87. The PAH derivatives were found at much lower levels than their parent PAH. Higher average indoor levels of all but three target compounds were found compared to outdoor levels. The higher outdoor levels of these three compounds (naphthalene dicarboxylic acid anhydride, pyrene dicarboxylic acid anhydride, and 2-nitrofluoranthene) are probably due to atmospheric transformation. Cigarette smoking was identified as the most-significant contributor to indoor levels of PAH and PAH derivatives. Homes with gas-heating systems appeared to have higher pollutant levels compared to homes with electric-heating systems.

  15. Small Sample Properties of an Adaptive Filter with Application to Low Volume Statistical Process Control

    SciTech Connect

    CROWDER, STEPHEN V.

    1999-09-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards while building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper we address the issue of low volume statistical process control. We investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. We develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, we study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. We show that far fewer data values are needed than is typically recommended for process control applications. We also demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  16. Small sample properties of an adaptive filter with application to low volume statistical process control

    SciTech Connect

    Crowder, S.V.; Eshleman, L.

    1998-08-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards white building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper the authors address the issue of low volume statistical process control. They investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. The authors develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, they study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. They show that far fewer data values are needed than is typically recommended for process control applications. And they demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  17. Comparison of sampling methods for radiocarbon dating of carbonyls in air samples via accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Schindler, Matthias; Kretschmer, Wolfgang; Scharf, Andreas; Tschekalinskij, Alexander

    2016-05-01

    Three new methods to sample and prepare various carbonyl compounds for radiocarbon measurements were developed and tested. Two of these procedures utilized the Strecker synthetic method to form amino acids from carbonyl compounds with either sodium cyanide or trimethylsilyl cyanide. The third procedure used semicarbazide to form crystalline carbazones with the carbonyl compounds. The resulting amino acids and semicarbazones were then separated and purified using thin layer chromatography. The separated compounds were then combusted to CO2 and reduced to graphite to determine 14C content by accelerator mass spectrometry (AMS). All of these methods were also compared with the standard carbonyl compound sampling method wherein a compound is derivatized with 2,4-dinitrophenylhydrazine and then separated by high-performance liquid chromatography (HPLC).

  18. Removal of Gross Air Embolization from Cardiopulmonary Bypass Circuits with Integrated Arterial Line Filters: A Comparison of Circuit Designs.

    PubMed

    Reagor, James A; Holt, David W

    2016-03-01

    Advances in technology, the desire to minimize blood product transfusions, and concerns relating to inflammatory mediators have lead many practitioners and manufacturers to minimize cardiopulmonary bypass (CBP) circuit designs. The oxygenator and arterial line filter (ALF) have been integrated into one device as a method of attaining a reduction in prime volume and surface area. The instructions for use of a currently available oxygenator with integrated ALF recommends incorporating a recirculation line distal to the oxygenator. However, according to an unscientific survey, 70% of respondents utilize CPB circuits incorporating integrated ALFs without a path of recirculation distal to the oxygenator outlet. Considering this circuit design, the ability to quickly remove a gross air bolus in the blood path distal to the oxygenator may be compromised. This in vitro study was designed to determine if the time required to remove a gross air bolus from a CPB circuit without a path of recirculation distal to the oxygenator will be significantly longer than that of a circuit with a path of recirculation distal to the oxygenator. A significant difference was found in the mean time required to remove a gross air bolus between the circuit designs (p = .0003). Additionally, There was found to be a statistically significant difference in the mean time required to remove a gross air bolus between Trial 1 and Trials 4 (p = .015) and 5 (p =.014) irrespective of the circuit design. Under the parameters of this study, a recirculation line distal to an oxygenator with an integrated ALF significantly decreases the time it takes to remove an air bolus from the CPB circuit and may be safer for clinical use than the same circuit without a recirculation line. PMID:27134304

  19. PM2.5 analog forecast and Kalman filter post-processing for the Community Multiscale Air Quality (CMAQ) model

    NASA Astrophysics Data System (ADS)

    Djalalova, Irina; Delle Monache, Luca; Wilczak, James

    2015-05-01

    A new post-processing method for surface particulate matter (PM2.5) predictions from the National Oceanic and Atmospheric Administration (NOAA) developmental air quality forecasting system using the Community Multiscale Air Quality (CMAQ) model is described. It includes three main components: • A real-time quality control procedure for surface PM2.5 observations; • Model post-processing at each observational site using historical forecast analogs and Kalman filtering; • Spreading the forecast corrections from the observation locations to the entire gridded domain. The methodology is tested using 12 months of CMAQ forecasts of hourly PM2.5, from December 01, 2009 through November 30, 2010. The model domain covers the contiguous USA, and model data are verified against U.S. Environmental Prediction Agency AIRNow PM2.5 observations measured at 716 stations over the CMAQ domain. The model bias is found to have a strong seasonal dependency, with a large positive bias in winter and a small bias in the summer months, and also to have a strong diurnal cycle. Five different post-processing techniques are compared, including a seven-day running mean subtraction, Kalman-filtering, analogs, and combinations of analogs and Kalman filtering. The most accurate PM2.5 forecasts have been found to be produced when using historical analogs of the hourly Kalman-filtered forecasts, referred to as KFAN. The choice of meteorological variables used in the hourly analog search is also found to have a significant effect. A monthly error analysis is computed, in each case using the remaining 11 months of the data set for the analog searches. The improvement of KFAN errors over the raw CMAQ model errors ranges from 50 to 75% for MAE and from 40 to 60% for the correlation coefficient. Since the post-processing analysis is only done at the locations where observations are available, the spreading of post-processing correction information over nearby model grid points is necessary to make

  20. Effect of ventilation systems and air filters on decay rates of particles produced by indoor sources in an occupied townhouse

    NASA Astrophysics Data System (ADS)

    Howard-Reed, Cynthia; Wallace, Lance A.; Emmerich, Steven J.

    Several studies have shown the importance of particle losses in real homes due to deposition and filtration; however, none have quantitatively shown the impact of using a central forced air fan and in-duct filter on particle loss rates. In an attempt to provide such data, we measured the deposition of particles ranging from 0.3 to 10 μm in an occupied townhouse and also in an unoccupied test house. Experiments were run with three different sources (cooking with a gas stove, citronella candle, pouring kitty litter), with the central heating and air conditioning (HAC) fan on or off, and with two different types of in-duct filters (electrostatic precipitator and ordinary furnace filter). Particle size, HAC fan operation, and the electrostatic precipitator had significant effects on particle loss rates. The standard furnace filter had no effect. Surprisingly, the type of source (combustion vs. mechanical generation) and the type of furnishings (fully furnished including carpet vs. largely unfurnished including mostly bare floor) also had no measurable effect on the deposition rates of particles of comparable size. With the HAC fan off, average deposition rates varied from 0.3 h -1 for the smallest particle range (0.3-0.5 μm) to 5.2 h -1 for particles greater than 10 μm. Operation of the central HAC fan approximately doubled these rates for particles <5 μm, and increased rates by 2 h -1 for the larger particles. An in-duct electrostatic precipitator increased the loss rates compared to the fan-off condition by factors of 5-10 for particles <2.5 μm, and by a factor of 3 for 2.5-5.0 μm particles. In practical terms, use of the central fan alone could reduce indoor particle concentrations by 25-50%, and use of an in-duct ESP could reduce particle concentrations by 55-85% compared to fan-off conditions.

  1. Accelerator Mass Spectrometric determination of radiocarbon in stratospheric CO2, retrieved from AirCore sampling.

    NASA Astrophysics Data System (ADS)

    Paul, Dipayan; Been, Henk A.; Chen, Huilin; Kivi, Rigel; Meijer, Harro A. J.

    2015-04-01

    In this decade, understanding the impact of human activities on climate is one of the key issues of discussion globally. The continuous rise in the concentration of greenhouse gases, e.g., CO2, CH4, etc. in the atmosphere, predominantly due to human activities, is alarming and requires continuous monitoring to understand the dynamics. Radiocarbon is an important atmospheric tracer and one of the many used in the understanding of the global carbon budget, which includes the greenhouse gases like CO2 and CH4. Measurement of 14C (or radiocarbon) in atmospheric CO2 generally requires collection of large air samples (few liters) from which CO2 is extracted and then the concentration of radiocarbon is determined. Currently, Accelerator Mass Spectrometry (AMS) is the most precise, reliable and widely used technique for atmospheric radiocarbon detection. However, the regular collection of air samples from troposphere and stratosphere, for example using aircraft, is prohibitively expensive. AirCore is an innovative atmospheric sampling system, developed by NOAA. It comprises of a long tube descending from a high altitude with one end open and the other closed, and has been demonstrated to be a reliable, cost-effective sampling system for high-altitude profile (up to ~ 30 km) measurements of CH4and CO2(Karion et al. 2010). In Europe, AirCore measurements are being performed on a regular basis near Sodankylä since September 2013. Here we describe the analysis of two such AirCore samples collected in July 2014, Finland, for determining the 14C concentration in stratospheric CO2. The two AirCore samples were collected on consecutive days. Each stratospheric AirCore sample was divided into six fractions, each containing ~ 35 μg CO2 (~9.5 μg C). Each fraction was separately trapped in 1 /4 inch coiled stainless steel tubing for radiocarbon measurements. The procedure for CO2 extraction from the stratospheric air samples; the sample preparation, with samples containing < 10

  2. Biofiltration of benzene contaminated air streams using compost-activated carbon filter media

    SciTech Connect

    Zhu, L.; Kocher, W.M.; Abumaizar, R.J.

    1998-12-31

    Three laboratory-scale biofilter columns were operated for 81 days to investigate the removal of benzene from a waste gas stream. The columns contain a mixture of yard waste and sludge compost as biomedia. Different amounts of granular activated carbon (GAC) are mixed with the compost in two of the three columns to evaluate the extent to which biofilter performance can be enhanced. The effects of different operating conditions on the performance of the removal of benzene from air were evaluated. More than 90% removal efficiency was observed for an influent benzene concentration of about 75 ppm and an air flow rate of 0.3 L/min. in all 3 columns under steady-state conditions. Under most cases of shock loading conditions, such as a sudden increase in the air flow rate, or the benzene concentration in the influent, the biofilters containing GAC provided higher removal efficiencies and more stable operation than the biofilter containing compost only.

  3. Removal of ammonia from contaminated air in a biotrickling filter - denitrifying bioreactor combination system.

    PubMed

    Sakuma, Takeyuki; Jinsiriwanit, Siriwat; Hattori, Toshihiro; Deshusses, Marc A

    2008-11-01

    The removal of gaseous ammonia in a system consisting of a biotrickling filter, a denitrification reactor and a polishing bioreactor for the trickling liquid was investigated. The system allowed sustained treatment of ammonia while preventing biological inhibition by accumulating nitrate and nitrite and avoiding generation of contaminated water. All bioreactors were packed with cattle bone composite ceramics, a porous support with a large interfacial area. Excellent removal of ammonia gas was obtained. The critical loading ranged from 60 to 120 gm(-3)h(-1) depending on the conditions, and loadings below 56 gm(-3)h(-1) resulted in essentially complete removal of ammonia. In addition, concentrations of ammonia, nitrite, nitrate and COD in the recycle liquid of the inlet and outlet of each reactor were measured to determine the fate of nitrogen in the reactor, close nitrogen balances and calculate nitrogen to COD ratios. Ammonia absorption and nitrification occurred in the biotrickling filter; nitrate and nitrite were biologically removed in the denitrification reactor and excess dissolved COD and ammonia were treated in the polishing bioreactor. Overall, ammonia gas was very successfully removed in the bioreactor system and steady state operation with respect to nitrogen species was achieved. PMID:18823641

  4. RETROFIT AIR POLLUTION CONTROL FILTER FOR RESTAURANT UNDERFIRED CHARBROILERS - PHASE I

    EPA Science Inventory

    Each day about 700,000 U.S. food service operations/restaurants emit more than 285 tons of particulate matter (PM) and more than 41 tons of volatile organic compounds (VOCs), a significant source of environmental air pollution that can adversely impact health. An estimated 32...

  5. A sample holder for measuring the magnetic properties of air-sensitive compounds

    NASA Astrophysics Data System (ADS)

    Berlie, Adam; Terry, Ian; Szablewski, Marek

    2011-01-01

    A sample holder is reported which has allowed the magnetic characterization of air-sensitive compounds to be made in a Quantum Design Magnetic Properties Measurement System as a function of the applied field (0-5 T), and at temperatures ranging from 2 to 290 K. The sample holder is in the form of a specially designed tube, which is made from high purity quartz, utilizes PTFE (polytetrafluoroethylene) plugs and is reusable. This construction also offers the benefit that no heat treatment of the holder is required during sample loading, making the sample holder suitable for thermally sensitive compounds. The application of this sample holder is demonstrated for the case of Ni(cod)2 (cod = 1,5-cyclooctadiene), a compound that decomposes when exposed to air and/or heat. This material's instability has, so far, prevented the magnetic characterization of the compound, with nickel nanoparticles, a product of the decomposition, usually being measured instead.

  6. ARRANGEMENT FOR REPLACING FILTERS

    DOEpatents

    Blomgren, R.A.; Bohlin, N.J.C.

    1957-08-27

    An improved filtered air exhaust system which may be continually operated during the replacement of the filters without the escape of unfiltered air is described. This is accomplished by hermetically sealing the box like filter containers in a rectangular tunnel with neoprene covered sponge rubber sealing rings coated with a silicone impregnated pneumatic grease. The tunnel through which the filters are pushed is normal to the exhaust air duct. A number of unused filters are in line behind the filters in use, and are moved by a hydraulic ram so that a fresh filter is positioned in the air duct. The used filter is pushed into a waiting receptacle and is suitably disposed. This device permits a rapid and safe replacement of a radiation contaminated filter without interruption to the normal flow of exhaust air.

  7. FILTER FOR HIGH VELOCITY GAS STREAMS

    DOEpatents

    Heckman, R.A.; Warner, H.F.

    1963-11-01

    An air filter that is particularly useful in air-sampling rockets is presented. The filter comprises a cellulose fiber mat having an evenly disposed thin coating of stearic acid. Protective loose weave fabric covers are stitched to the front and back of the fiber mat, the stitching being in the form of a sine wave spiraled from the midpoint of the mat out to its periphery. (AEC)

  8. A NEW NON-DESTRUCTIVE METHOD FOR CHEMICAL ANALYSIS OF PARTICULATE MATTER FILTERS: THE CASE OF MANGANESE AIR POLLUTION IN VALLECAMONICA (ITALY)

    PubMed Central

    Borgese, Laura; Zacco, Annalisa; Pal, Sudipto; Bontempi, Elza; Lucchini, Roberto; Zimmerman, Neil; Depero, Laura E.

    2011-01-01

    Total Reflection X-ray Fluorescence (TXRF) is a well-established technique for chemical analysis, but it is mainly employed for quality control in the electronics semiconductor industry. The capability to analyze liquid and uniformly thin solid samples makes this technique suitable for other applications, and especially in the very critical field of environmental analysis. Comparison with standard methods like Inductively Coupled Plasma (ICP) and Atomic Absorption Spectroscopy (AAS) show that TXRF is a practical, accurate, and reliable technique in occupational settings. Due to the greater sensitivity necessary in trace heavy metal detection, TXRF is also suitable for environmental chemical analysis. In this paper we show that based on appropriate standards, TXRF can be considered for non-destructive routine quantitative analysis of environmental matrices such as air filters. This work has been developed in the frame of the EU-FP6 PHIME (Public Health Impact of long-term, low-level Mixed element Exposure in susceptible population strata) Integrated Project (www.phime.org). The aim of this work was to investigate Mn air pollution in the area of Vallecamonica (Italy). PMID:21315919

  9. Validation of the integrity of a HEPA filter system.

    PubMed

    Wang, Wei-Hsung

    2003-11-01

    The objective of this study was to establish a delayed air sampling method to verify the integrity of an existing HEPA filter system in a ventilated fume hood. (238U,232Th)O2 microspheres were generated to fabricate cement nuclear fuel pellets in a HEPA-filtered hood. To comply with the air effluent concentration limits by NRC, the capture efficiency of the HEPA filter was examined. An in-line isokinetic air sampling system was installed downstream of the HEPA filter. Utilizing a gas flow proportional counter, 212Pb was used as a surrogate to indicate any possible penetration of the (238U,232Th)O2 particles through the HEPA filter. Based on the experimental results, this delayed sampling method proved to be an easy and effective way to validate the integrity of the HEPA filter. PMID:14570263

  10. Passive dosimeters for nitrogen dioxide in personal/indoor air sampling: A review

    PubMed Central

    Yu, Chang Ho; Morandi, Maria T.; Weisel, Clifford P.

    2015-01-01

    Accurate measurement of nitrogen dioxide concentrations in both outdoor and indoor environments, including personal exposures, is a fundamental step for linking atmospheric nitrogen dioxide levels to potential health and ecological effects. The measurement has been conducted generally in two ways: active (pumped) sampling and passive (diffusive) sampling. Diffusion samplers, initially developed and used for workplace air monitoring, have been found to be useful and cost-effective alternatives to conventional pumped samplers for monitoring ambient, indoor and personal exposures at the lower concentrations found in environmental settings. Since the 1970s, passive samplers have been deployed for ambient air monitoring in urban and rural sites, and to determine personal and indoor exposure to NO2. This article reviews the development of NO2 passive samplers, the sampling characteristics of passive samplers currently available, and their application in ambient and indoor air monitoring and personal exposure studies. The limitations and advantages of the various passive sampler geometries (i.e., tube, badge, and radial type) are also discussed. This review provides researchers and risk assessors with practical information about NO2 passive samplers, especially useful when designing field sampling strategies for exposure and indoor/outdoor air sampling. PMID:18446185

  11. Non-porous membrane-assisted liquid-liquid extraction of UV filter compounds from water samples.

    PubMed

    Rodil, Rosario; Schrader, Steffi; Moeder, Monika

    2009-06-12

    A method for the determination of nine UV filter compounds [benzophenone-3 (BP-3), isoamyl methoxycinnamate, 4-methylbenzylidene camphor, octocrylene (OC), butyl methoxydibenzoylmethane, ethylhexyl dimethyl p-aminobenzoate (OD-PABA), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate and homosalate] in water samples was developed and evaluated. The procedure includes non-porous membrane-assisted liquid-liquid extraction (MALLE) and LC-atmospheric pressure photoionization (APPI)-MS/MS. Membrane bags made of different polymeric materials were examined to enable a fast and simple extraction of the target analytes. Among the polymeric materials tested, low- and high-density polyethylene membranes proved to be well suited to adsorb the analytes from water samples. Finally, 2 cm length tailor-made membrane bags were prepared from low-density polyethylene in order to accommodate 100 microL of propanol. The fully optimised protocol provides recoveries from 76% to 101% and limits of detection (LOD) between 0.4 ng L(-1) (OD-PABA) and 16 ng L(-1) (EHMC). The interday repeatability of the whole protocol was below 18%. The effective separation of matrix molecules was proved by only marginal matrix influence during the APPI-MS analysis since no ion suppression effects were observed. During the extraction step, the influence of the matrix was only significant when non-treated wastewater was analysed. The analysis of lake water indicated the presence of seven UV filter compounds included in this study at concentrations between 40 ng L(-1) (BP-3) and 4381 ng L(-1) (OC). In non-treated wastewater several UV filters were also detected at concentration levels as high as 5322 ng L(-1) (OC). PMID:19419722

  12. Anisotropic tubular filtering for automatic detection of acid-fast bacilli in Ziehl-Neelsen stained sputum smear samples

    NASA Astrophysics Data System (ADS)

    Raza, Shan-e.-Ahmed; Marjan, M. Q.; Arif, Muhammad; Butt, Farhana; Sultan, Faisal; Rajpoot, Nasir M.

    2015-03-01

    One of the main factors for high workload in pulmonary pathology in developing countries is the relatively large proportion of tuberculosis (TB) cases which can be detected with high throughput using automated approaches. TB is caused by Mycobacterium tuberculosis, which appears as thin, rod-shaped acid-fast bacillus (AFB) in Ziehl-Neelsen (ZN) stained sputum smear samples. In this paper, we present an algorithm for automatic detection of AFB in digitized images of ZN stained sputum smear samples under a light microscope. A key component of the proposed algorithm is the enhancement of raw input image using a novel anisotropic tubular filter (ATF) which suppresses the background noise while simultaneously enhancing strong anisotropic features of AFBs present in the image. The resulting image is then segmented using color features and candidate AFBs are identified. Finally, a support vector machine classifier using morphological features from candidate AFBs decides whether a given image is AFB positive or not. We demonstrate the effectiveness of the proposed ATF method with two different feature sets by showing that the proposed image analysis pipeline results in higher accuracy and F1-score than the same pipeline with standard median filtering for image enhancement.

  13. Toward accurate molecular identification of species in complex environmental samples: testing the performance of sequence filtering and clustering methods

    PubMed Central

    Flynn, Jullien M; Brown, Emily A; Chain, Frédéric J J; MacIsaac, Hugh J; Cristescu, Melania E

    2015-01-01

    Metabarcoding has the potential to become a rapid, sensitive, and effective approach for identifying species in complex environmental samples. Accurate molecular identification of species depends on the ability to generate operational taxonomic units (OTUs) that correspond to biological species. Due to the sometimes enormous estimates of biodiversity using this method, there is a great need to test the efficacy of data analysis methods used to derive OTUs. Here, we evaluate the performance of various methods for clustering length variable 18S amplicons from complex samples into OTUs using a mock community and a natural community of zooplankton species. We compare analytic procedures consisting of a combination of (1) stringent and relaxed data filtering, (2) singleton sequences included and removed, (3) three commonly used clustering algorithms (mothur, UCLUST, and UPARSE), and (4) three methods of treating alignment gaps when calculating sequence divergence. Depending on the combination of methods used, the number of OTUs varied by nearly two orders of magnitude for the mock community (60–5068 OTUs) and three orders of magnitude for the natural community (22–22191 OTUs). The use of relaxed filtering and the inclusion of singletons greatly inflated OTU numbers without increasing the ability to recover species. Our results also suggest that the method used to treat gaps when calculating sequence divergence can have a great impact on the number of OTUs. Our findings are particularly relevant to studies that cover taxonomically diverse species and employ markers such as rRNA genes in which length variation is extensive. PMID:26078860

  14. Reducing patients’ exposures to asthma and allergy triggers in their homes: an evaluation of effectiveness of grades of forced air ventilation filters

    PubMed Central

    Minegishi, Taeko; Allen, Joseph G.; McCarthy, John F.; Spengler, John D.; MacIntosh, David L.

    2014-01-01

    Objective Many interventions to reduce allergen levels in the home are recommended to asthma and allergy patients. One that is readily available and can be highly effective is the use of high performing filters in forced air ventilation systems. Methods We conducted a modeling analysis of the effectiveness of filter-based interventions in the home to reduce airborne asthma and allergy triggers. This work used “each pass removal efficiency” applied to health-relevant size fractions of particles to assess filter performance. We assessed effectiveness for key allergy and asthma triggers based on applicable particle sizes for cat allergen, indoor and outdoor sources of particles <2.5 µm in diameter (PM2.5), and airborne influenza and rhinovirus. Results Our analysis finds that higher performing filters can have significant impacts on indoor particle pollutant levels. Filters with removal efficiencies of >70% for cat dander particles, fine particulate matter (PM2.5) and respiratory virus can lower concentrations of those asthma triggers and allergens in indoor air of the home by >50%. Very high removal efficiency filters, such as those rated a 16 on the nationally recognized Minimum Efficiency Removal Value (MERV) rating system, tend to be only marginally more effective than MERV12 or 13 rated filters. Conclusions The results of this analysis indicate that use of a MERV12 or higher performing air filter in home ventilation systems can effectively reduce indoor levels of these common asthma and allergy triggers. These reductions in airborne allergens in turn may help reduce allergy and asthma symptoms, especially if employed in conjunction with other environmental management measures recommended for allergy and asthma patients. PMID:24555523

  15. Passive air sampling of PCBs, PBDEs, and organochlorine pesticides across Europe.

    PubMed

    Jaward, Foday M; Farrar, Nick J; Harner, Tom; Sweetman, Andrew J; Jones, Kevin C

    2004-01-01

    This study presents concurrently sampled ambient air data for a range of persistent organic pollutants at the continental scale. This was achieved using a passive air sampling system, deploying polyurethane foam disks, which was prepared in one laboratory, sealed to prevent contamination, sent out by courier to volunteers participating in different countries, exposed for 6 weeks, collected, resealed, and returned to the laboratory for analysis. Europe was the study area--a region with a history of extensive POPs usage and emission and with marked national differences in population density, the degree of urbanization and industrial/agricultural development. Samplers were deployed at remote/rural/urban locations in 22 countries and analyzed for PCBs, a range of organochlorine pesticides (HCB, alpha-HCH, gamma-HCH, ppDDT, ppDDE), and PBDEs. Calculated air concentrations were in line with those obtained by conventional active air sampling techniques. The geographical pattern of all compounds reflected suspected regional emission patterns and highlighted localized hotspots. PCB and PBDE levels varied by over 2 orders of magnitude; the highest values were detected in areas of high usage and were linked to urbanized areas. HCB was relatively uniformly distributed, reflecting its persistence and high degree of mixing in air. Higher gamma-HCH, ppDDT, and ppDDE levels generally occurred in South and East Europe. PMID:14740714

  16. Inter-conversion of Chromium Species During Air Sampling: Effects of O3, NO2, SO2, Particle Matrices, Temperature and Humidity

    PubMed Central

    Huang, Lihui; Fan, Zhihua (Tina); Yu, Chang Ho; Hopke, Philip K.; Lioy, Paul J.; Buckley, Brian T.; Lin, Lin; Ma, Yingjun

    2013-01-01

    The inter-conversion between Cr(VI), a pulmonary carcinogen, and Cr(III), an essential human nutrient, poses challenges to the measurement of Cr(VI) in airborne particles. Chamber and field tests were conducted to identify the factors affecting Cr(VI)-Cr(III) inter-conversion in the basic filter medium under typical sampling conditions. In the chamber tests, isotopically enriched 53Cr(VI) and 50Cr(III) were spiked on diesel particulate matter (DPM) and secondary organic aerosol (SOA) that were pre-collected on a basic MCE filter. The filter samples were then exposed to clean air or the air containing SO2 (50 and 160 ppb), 100 ppb O3, or 150 ppb NO2 for 24 hours at 16.7 LPM flow rate at designated temperature (20 and 31°C) and RH (40% and 70%) conditions. Exposure to 160 ppb SO2 had the greatest effect on 53Cr(VI) reduction, with 53Cr(VI) recovery of 31.7 ± 15.8% (DPM) and 42.0 ± 7.9% (SOA). DPM and SOA matrix induced 53Cr(VI) reduction when exposed to clean air while reactive oxygen species in SOA could promote 50Cr(III) oxidation. Deliquescence when RH increased from 40% to 70% led to conversion of Cr(III) in SOA, whereas oxidized organics in DPM and SOA enhanced hygroscopicity and thus facilitated Cr(VI) reduction. Field tests showed seasonal variation of Cr(VI)-Cr(III) inter-conversion during sampling. Correction of the inter-conversion using USEPA method 6800 is recommended to improve accuracy of ambient Cr(VI) measurements. PMID:23550818

  17. Valveless sampling of ambient air for analysis by capillary gas chromatography

    SciTech Connect

    Stephens, E.R. )

    1989-09-01

    A method for the high resolution, high sensitivity analysis of polluted air for individual organic compounds is described. Samples collected from 50 mL of ambient air at 87 K (liquid argon) are injected without use of a valve into a silica capillary column which is then temperature programmed from {minus}30{degree}C to 180{degree}C. Hydrocarbons (4 to 10 carbons) as well as carbonyl compounds, chlorinated compounds and terpenes can be identified and quantified. The detection limit, not strongly dependent on carbon number, is estimated to be 0.3 ppbc in a 50 mL sample. Use of small samples eliminates the need to remove water vapor, a procedure which might jeopardize sample integrity.

  18. Theoretical model for the evaporation loss of PM2.5 during filter sampling

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Nan; Lin, Sih-Fan; Tsai, Chuen-Jinn; Wu, Yueh-Chuen; Chen, Chung-Fang

    2015-05-01

    The evaporation losses of PM2.5 particles in eight different size ranges corresponding to the 4th-10th stages and after filter of the MOUDI were calculated theoretically and then integrated to obtain the total PM2.5 evaporation loss. Results show that when PM2.5 particles are nearly neutral with pH in the range of 7-8, the evaporated concentrations predicted by the present model agree well with the experimental data with an average absolute difference of 20.2 ± 11.1%. When PM2.5 aerosols are acidic with pH less than 3.5, additional loss of nitrate and chloride can occur due to chemical interactions between collected particles and strong acids which are not considered in the present model. Under pH neutral conditions, the theoretical model was then used to examine the effect of PM2.5 concentration, gas-to-particle ratio, ambient temperature and relative humidity on the extent of evaporation loss. Results show that evaporated PM2.5 concentration increases with increasing temperature and decreasing relative humidity, PM2.5 concentration and gas-to-particle ratio.

  19. Development and calibration of real-time PCR for quantification of airborne microorganisms in air samples

    NASA Astrophysics Data System (ADS)

    An, Hey Reoun; Mainelis, Gediminas; White, Lori

    This manuscript describes the coupling of bioaerosol collection and the use of real-time PCR (RT-PCR) to quantify the airborne bacteria. The quantity of collected bacteria determined by RT-PCR is compared with conventional quantification techniques, such as culturing, microscopy and airborne microorganism counting by using optical particle counter (OPC). Our data show that an experimental approach used to develop standard curves for use with RT-PCR is critical for accurate sample quantification. Using universal primers we generated 12 different standard curves which were used to quantify model organism Escherichia coli (Migula) Catellani from air samples. Standard curves prepared using a traditional approach, where serially diluted genomic DNA extracted from pure cultured bacteria were used in PCR reaction as a template DNA yielded significant underestimation of sample quantities compared to airborne microorganism concentration as measured by an OPC. The underestimation was especially pronounced when standard curves were built using colony forming units (CFUs). In contrast, the estimate of cell concentration in an air sample by RT-PCR was more accurate (˜60% compared to the airborne microorganism concentration) when the standard curve was built using aerosolized E. coli. The accuracy improved even further (˜100%) when air samples used to build the standard curves were diluted first, then the DNA extracted from each dilution was amplified by the RT-PCR—to mimic the handling of air samples with unknown and possibly low concentration. Therefore, our data show that standard curves used for quantification by RT-PCR needs to be prepared using the same environmental matrix and procedures as handling of the environmental sample in question. Reliance on the standard curves generated with cultured bacterial suspension (a traditional approach) may lead to substantial underestimation of microorganism quantities in environmental samples.

  20. The effect of compressed air foam on the detection of hydrocarbon fuels in fire debris samples.

    PubMed

    Coulson, S A; Morgan-Smith, R K; Noble, D

    2000-01-01

    In 1998/99 the New Zealand Fire Service implemented compressed air foam delivery systems for the suppression of fires in rural areas. This study investigated whether the introduction of the foam to the seat of the fire created any problems in subsequent analyses of fire debris samples. No significant interferences from the foam were found when the samples were analysed by direct headspace using activated carbon strips. The only foam component detected was limonene. PMID:11094822

  1. ENVIRONMENTAL SAMPLING USING LOCATION SPECIFIC AIR MONITORING IN BULK HANDLING FACILITIES

    SciTech Connect

    Sexton, L.; Hanks, D.; Degange, J.; Brant, H.; Hall, G.; Cable-Dunlap, P.; Anderson, B.

    2011-06-07

    Since the introduction of safeguards strengthening measures approved by the International Atomic Energy Agency (IAEA) Board of Governors (1992-1997), international nuclear safeguards inspectors have been able to utilize environmental sampling (ES) (e.g. deposited particulates, air, water, vegetation, sediments, soil and biota) in their safeguarding approaches at bulk uranium/plutonium handling facilities. Enhancements of environmental sampling techniques used by the IAEA in drawing conclusions concerning the absence of undeclared nuclear materials or activities will soon be able to take advantage of a recent step change improvement in the gathering and analysis of air samples at these facilities. Location specific air monitoring feasibility tests have been performed with excellent results in determining attribute and isotopic composition of chemical elements present in an actual test-bed sample. Isotopic analysis of collected particles from an Aerosol Contaminant Extractor (ACE) collection, was performed with the standard bulk sampling protocol used throughout the IAEA network of analytical laboratories (NWAL). The results yielded bulk isotopic values expected for the operations. Advanced designs of air monitoring instruments such as the ACE may be used in gas centrifuge enrichment plants (GCEP) to detect the production of highly enriched uranium (HEU) or enrichments not declared by a State. Researchers at Savannah River National Laboratory in collaboration with Oak Ridge National Laboratory are developing the next generation of ES equipment for air grab and constant samples that could become an important addition to the international nuclear safeguards inspector's toolkit. Location specific air monitoring to be used to establish a baseline environmental signature of a particular facility employed for comparison of consistencies in declared operations will be described in this paper. Implementation of air monitoring will be contrasted against the use of smear ES

  2. Development of a wireless air pollution sensor package for aerial-sampling of emissions

    EPA Science Inventory

    A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particulate matter wi...

  3. the nature of air flow near the inlets of blunt dust sampling probes

    NASA Astrophysics Data System (ADS)

    Vincent, J. H.; Hutson, D.; Mark, D.

    This paper sets out to describe the nature of air flow near blunt dust samplers in a way which allows a relatively simple assessment of their performances for collecting dust particles. Of particular importance is the shape of the limiting stream surface which divides the sampled air from that which passes outside the sampler, and how this is affected by the free-stream air velocity, the sampling flow rate, and the shape of the sampler body. This was investigated for two-dimensional and axially-symmetric sampler systems by means of complementary experiments using electrolytic tank potential flow analogues and a wind tunnel respectively. For extreme conditions the flow of air entering the sampling orifice may be wholly divergent or wholly convergent. For a wide range of intermediate conditions, however, the flow first diverges then converges, exhibiting a so-called "spring onion effect". Whichever of these applies for a particular situation, the flow may be considered to consist of two parts, the outer one dominated by the flow about the sampler body and the inner one dominated by the flow into the sampling orifice. Particle transport in this two-part flow may be assessed using ideas borrowed from thin-walled probe theory.

  4. INTERCOMPARISON OF SAMPLING TECHNIQUES FOR TOXIC ORGANIC COMPOUNDS IN INDOOR AIR

    EPA Science Inventory

    People spend a major fraction of their time indoors, and there is concern over exposure to volatile organic compounds present in indoor air. The study was initiated to compare several VOC sampling techniques in an indoor environment. The techniques which were compared include dis...

  5. Development of a wireless air pollution sensor package for aerial-sampling of emissions

    EPA Science Inventory

    A new sensor system for mobile and aerial emission sampling was developed for open area pollutant sources, such as prescribed forest burns. The sensor system, termed “Kolibri”, consists of multiple low-cost air quality sensors measuring CO2, CO, samplers for particula...

  6. COMPARISON OF FAST GC/TOFMS WITH METHOD TO-14 FOR ANALYSIS OF AMBIENT AIR SAMPLES

    EPA Science Inventory

    Field studies using portable gas chromatographs (PGC) to analyze volatile organic compounds in ambient air usually include, as reference standard method, the analysis of concurrent, collocated canister samples by EPA Method TO-14. Each laboratory analysis takes about an hour a...

  7. INDOOR AIR SAMPLING AND MUTAGENICITY STUDIES OF EMISSIONS FROM UNVENTED COAL COMBUSTION (JOURNAL VERSION)

    EPA Science Inventory

    The purpose of the study is to develop sampling strategies and bioassay methods for indoor air in homes, the authors developed a medium-volume sampler to collect the <10 - micrometers particulate matter and semivolatile organics, and used high-volume particulate sampler for compa...

  8. ANALYSIS OF VOCS IN AMBIENT AIR USING MULTISORBENT PACKINGS FOR VOC ACCUMULATION AND SAMPLE DRYING

    EPA Science Inventory

    Solid multisorbent packings have been characterized for trapping and release efficiency of trace (10-20 ppbv in humidified zero air) volatile organic compounds (VOCs). he use of a two-stage trapping system reduces sample water content typically by more than 95.5% while maintainin...

  9. COMPARISON OF MOLD CONCENTRATIONS IN INDOOR AND OUTDOOR AIR SAMPLED SIMULTANEOUSLY AND THEN QUANTIFIED BY MSQPCR

    EPA Science Inventory

    Mold specific quantitative PCR (MSQPCR) was used to measure the concentrations of the 36 mold species in indoor and outdoor air samples that were taken simultaneously for 48 hours in and around 17 homes in Cincinnati, Ohio. The total spore concentrations of 353 per m3...

  10. CLEANLINESS OF COMMON AIR SAMPLING SORBENTS FOR APPLICATION TO PHENOLIC COMPOUNDS MEASUREMENT USING SUPERCRITICAL FLUID EXTRACTION

    EPA Science Inventory

    The trace-level measurement of phenolic compounds in the ambient air is complicated by the acidic and polar nature of the compounds especially during recovery from the sampling medium. ecently, supercritical fluid extraction (SFE) has been proposed as an alternative extraction me...

  11. NON-POLAR VOLATILE ORGANIC COMPOUNDS IN WHOLE AIR SAMPLES FROM THE AUTOEX STUDIES

    EPA Science Inventory

    Air samples were captured in SUMMA polished stainless steel canisters and returned to the laboratory for analysis of trace level volatile organic compounds by gas chromatography - mass spectrometry. ampling was performed over 2-hour periods at various distances from heavily trave...

  12. Collecting Samples of Workplace Air. Module 8. Vocational Education Training in Environmental Health Sciences.

    ERIC Educational Resources Information Center

    Consumer Dynamics Inc., Rockville, MD.

    This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on collecting samples of workplace air. Following guidelines for students and instructors and an introduction that explains what the student will learn are three lessons: (1) collecting information about…

  13. Air purification equipment combining a filter coated by silver nanoparticles with a nano-TiO2 photocatalyst for use in hospitals

    NASA Astrophysics Data System (ADS)

    Son Le, Thanh; Hien Dao, Trong; Nguyen, Dinh Cuong; Chau Nguyen, Hoai; Balikhin, I. L.

    2015-03-01

    X-ray diffraction, scanning electron microscopy and transmission electron microscopy showed that TiO2 particles synthesized by a sol-gel procedure exhibited uniform size about 16-20 nm. This nanopowder was deposited on a porous quartz tube (D = 74 mm, L = 418 mm, deposit density ˜16.4 mg cm-2) through an intermediate adhesive polymethylmethacrylate layer to manufacture a photocatalytic filter tube. A polypropylene pre-filter was coated with a nanosilver layer (particle size ˜20 nm) prepared by aqueous molecular solution method. An air cleaner of 250 m3 h-1 capacity equipped with this pre-filter, an electrostatic air filter, 4 photocatalytic filter tubes and 4 UV-A lamps (36 W) presented the high degradation ability for certain volatile organic compounds (VOCs), bacteria and fungi. The VOCs degradation performances of the equipment with respect to divers compounds are different: in a 10 m3 box, 91.6% of butanol was removed within 55 min, 80% of acetone within 100 min, 70.1% of diethyl ether within 120 min and only 43% of benzene was oxidized within 150 min. Over 99% of bacteria and fungi were killed after the air passage through the equipment. For application, it was placed in the intensive care room (volume of 125 m3) of E hospital in Hanoi; 69% of bacteria and 63% of fungi were killed within 6 h.

  14. Vapor-phase and particulate-associated pesticides and PCB concentrations in eastern North Dakota air samples

    SciTech Connect

    Hawthorne, S.B.; Miller, D.J.; Louie, P.K.K.

    1996-05-01

    Vapor-phase and suspended particulate (<50 {mu}m) samples were collected on polyurethane foam (PUF) and quartz fiber filters in rural North Dakota to determine the air concentrations of pesticides in an area where agriculture is a primary source of semivolatile pollutants. Samples were collected at two sites from 1992 to 1994 that were at least 0.4 km from the nearest farmed fields and known application of pesticides, and analyzed for 22 different organochlorine, triazine, and acid herbicide pesticides. Fourteen pesticides were found above the detection limits (typically <1 pg/m{sup 3}). Concentrations of polychlorinated biphenyl (PCB) congeners were much lower (<50 pg/m{sup 3} in all cases) than many of the pesticides. These results demonstrate that pesticides are among the most prevalent chlorinated semivolatile pollutants present in rural North Dakota, that significant transport of pesticides occurs both in the vapor-phase and on suspended particulate matter, and that blown soil may be a significant mechanism for introducing pesticides into surface and ground waters. 32 refs., 2 figs., 4 tabs.

  15. Whole Air Sampling During NASA's March-April 1999 Pacific Exploratory Expedition (PEM-Tropics B)

    NASA Technical Reports Server (NTRS)

    Blake, Donald R.

    2001-01-01

    University of California, Irvine (UCI) collected more than 4500 samples whole air samples collected over the remote Pacific Ocean during NASA's Global Tropospheric Experiment (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) in March and early April 1999. Approximately 140 samples during a typical 8-hour DC-8 flight, and 120 canisters for each 8-hour flight aboard the P-3B. These samples were obtained roughly every 3-7 min during horizontal flight legs and 1-3 min during vertical legs. The filled canisters were analyzed in the laboratory at UCI within ten days of collection. The mixing ratios of 58 trace gases comprising hydrocarbons, halocarbons, alkyl nitrates and DMS were reported (and archived) for each sample. Two identical analytical systems sharing the same standards were operated simultaneously around the clock to improve canister turn-around time and to keep our measurement precision optimal. This report presents a summary of the results for sample collected.

  16. Chemical reactivities of ambient air samples in three Southern California communities

    PubMed Central

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

    2015-01-01

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

  17. Mathematical Estimation of the Level of Microbial Contamination on Spacecraft Surfaces by Volumetric Air Sampling

    PubMed Central

    Oxborrow, G. S.; Roark, A. L.; Fields, N. D.; Puleo, J. R.

    1974-01-01

    Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model. PMID:4151118

  18. Mathematical estimation of the level of microbial contamination on spacecraft surfaces by volumetric air sampling

    NASA Technical Reports Server (NTRS)

    Oxborrow, G. S.; Roark, A. L.; Fields, N. D.; Puleo, J. R.

    1974-01-01

    Microbiological sampling methods presently used for enumeration of microorganisms on spacecraft surfaces require contact with easily damaged components. Estimation of viable particles on surfaces using air sampling methods in conjunction with a mathematical model would be desirable. Parameters necessary for the mathematical model are the effect of angled surfaces on viable particle collection and the number of viable cells per viable particle. Deposition of viable particles on angled surfaces closely followed a cosine function, and the number of viable cells per viable particle was consistent with a Poisson distribution. Other parameters considered by the mathematical model included deposition rate and fractional removal per unit time. A close nonlinear correlation between volumetric air sampling and airborne fallout on surfaces was established with all fallout data points falling within the 95% confidence limits as determined by the mathematical model.

  19. Estimating occupancy and abundance of stream amphibians using environmental DNA from filtered water samples

    USGS Publications Warehouse

    Pilliod, David S.; Goldberg, Caren S.; Arkle, Robert S.; Waits, Lisette P.

    2013-01-01

    Environmental DNA (eDNA) methods for detecting aquatic species are advancing rapidly, but with little evaluation of field protocols or precision of resulting estimates. We compared sampling results from traditional field methods with eDNA methods for two amphibians in 13 streams in central Idaho, USA. We also evaluated three water collection protocols and the influence of sampling location, time of day, and distance from animals on eDNA concentration in the water. We found no difference in detection or amount of eDNA among water collection protocols. eDNA methods had slightly higher detection rates than traditional field methods, particularly when species occurred at low densities. eDNA concentration was positively related to field-measured density, biomass, and proportion of transects occupied. Precision of eDNA-based abundance estimates increased with the amount of eDNA in the water and the number of replicate subsamples collected. eDNA concentration did not vary significantly with sample location in the stream, time of day, or distance downstream from animals. Our results further advance the implementation of eDNA methods for monitoring aquatic vertebrates in stream habitats.

  20. Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis

    SciTech Connect

    MULKEY, C.H.

    1999-07-06

    This document describes the results of the data quality objective (DQO) process undertaken to define data needs for state and federal requirements associated with toxic, hazardous, and/or radiological air emissions under the jurisdiction of the River Protection Project (RPP). Hereafter, this document is referred to as the Air DQO. The primary drivers for characterization under this DQO are the regulatory requirements pursuant to Washington State regulations, that may require sampling and analysis. The federal regulations concerning air emissions are incorporated into the Washington State regulations. Data needs exist for nonradioactive and radioactive waste constituents and characteristics as identified through the DQO process described in this document. The purpose is to identify current data needs for complying with regulatory drivers for the measurement of air emissions from RPP facilities in support of air permitting. These drivers include best management practices; similar analyses may have more than one regulatory driver. This document should not be used for determining overall compliance with regulations because the regulations are in constant change, and this document may not reflect the latest regulatory requirements. Regulatory requirements are also expected to change as various permits are issued. Data needs require samples for both radionuclides and nonradionuclide analytes of air emissions from tanks and stored waste containers. The collection of data is to support environmental permitting and compliance, not for health and safety issues. This document does not address health or safety regulations or requirements (those of the Occupational Safety and Health Administration or the National Institute of Occupational Safety and Health) or continuous emission monitoring systems. This DQO is applicable to all equipment, facilities, and operations under the jurisdiction of RPP that emit or have the potential to emit regulated air pollutants.

  1. Report on sampling and analysis of exhaust air at the 221-T and 2706-T buildings

    SciTech Connect

    Stauffer, M.

    1997-09-22

    This report presents analytical results from exhaust air samples collected at stacks 221-T and 2706-T of the T-Plant. The samples were collected with SUMMA canisters over a 24 hour interval and were analyzed by gas chromatography-mass spectrometry using a modified EPA TO-14 procedure. The data suggest that the buildings had generally low concentrations of volatile organic compounds (< 40 ppbv). However, samples from building 2706-T did have significant amounts of non-target higher-boiling hydrocarbons, probably from a petroleum destination fraction.

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

    SciTech Connect

    2000-07-11

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

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

    DOEpatents

    Zaromb, Solomon

    2000-01-01

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

  4. Water and entrapped air redistribution in heterogeneous sand sample: Quantitative neutron imaging of the process

    NASA Astrophysics Data System (ADS)

    Snehota, Michal; Jelinkova, Vladimira; Sobotkova, Martina; Sacha, Jan; Vontobel, Peter; Hovind, Jan

    2015-02-01

    Saturated flow in soil with the occurrence of preferential flow often exhibits temporal changes of saturated hydraulic conductivity even during the time scale of a single infiltration event. These effects, observed in a number of experiments done mainly on heterogeneous soils, are often attributed to the changing distribution of water and air in the sample. We have measured the variation of the flow rates during the steady state stage of the constant head ponded infiltration experiment conducted on a packed sample composed of three different grades of sand. The experiment was monitored by quantitative neutron imaging, which provided information about the spatial distribution of water in the sample. Measurements were taken during (i) the initial stages of infiltration by neutron radiography and (ii) during the steady state flow by neutron tomography. A gradual decrease of the hydraulic conductivity has been observed during the first 4 h of the infiltration event. A series of neutron tomography images taken during the quasi-steady state stage showed the trapping of air bubbles in coarser sand. Furthermore, the water content in the coarse sand decreased even more while the water content in the embedded fine sand blocks gradually increased. The experimental results support the hypothesis that the effect of the gradual hydraulic conductivity decrease is caused by entrapped air redistribution and the build up of bubbles in preferential pathways. The trapped air thus restricts the preferential flow pathways and causes lower hydraulic conductivity.

  5. Volatile organic components of air samples collected from Vertical Launch Missile capsules. Summary report

    SciTech Connect

    Tappan, D.V.; Knight, D.R.; Heyder, E.; Weathersby, P.K.

    1988-09-27

    Gas chromatographic/mass spectroscopic analyses are presented for the volatile organic components found in air samples collected from the inboard vents from Vertical Launch System (VLS) missile capsules aboard a 688 class submarine. Similar analyses were also conducted for a sample of the ship's high pressure air used to fill the missile tubes. A wide variety of organics was detected in the air from the missile capsules; and while no unique components have yet been identified, a significant contribution has been shown to be made by pressure-ventilation of the VLS capsules into the submarine atmosphere which is already heavily laden with volatile organic compounds. The most apparent conclusion from these preliminary analyses is that the mixtures of organic components in the air within VLS missile capsules vary greatly from capsule to capsule (and probably from time to time). Many such samples need to be investigated to provide sufficient information to judge the seriousness of the possibility of venting toxic components into the submarine atmosphere during the maintenance or firing of VLS missiles.

  6. Soyuz 22 Return Samples: Assessment of Air Quality Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Jams, John T.

    2010-01-01

    Three mini-grab sample containers (m-GSCs) were returned aboard Soyuz 22 because of concerns that new air pollutants were present in the air and these were getting into the water recovery system. The Total Organic Carbon Analyzer had been giving increasing readings of total organic carbon (TOC) in the potable water, and it was postulated that an increased load into the system was responsible. The toxicological assessment of 3 m-GSCs from the ISS is shown in Table 1. The recoveries of the 3 standards (as listed above) from the GSCs averaged 103, 95 and 76%, respectively. Recovery from formaldehyde control badges were 90 and 91%.

  7. Electronic Nose and Use of Bags to Collect Odorous Air Samples in Meat Quality Analysis

    NASA Astrophysics Data System (ADS)

    Sala, G.; Masoero, G.; Battaglini, L. M.; Cornale, P.; Barbera, S.

    2009-05-01

    To test EN reliability and use of bags on meat, 17 bulls (one group of 9 and one of 8) fed similarly, except for a supplementary feedingstuff, were used. Samples were prepared according to the MCS protocol and repeated three times on different days for a total of 51 samples. Bags were used to collect raw and cooked meat air samples, and to test odour changes among samples analysed at different times. The first time analysis was performed immediately after collection then was repeated, 1 hour, 1 day and 1 week later. The Electronic Nose is very discriminant and clear differences were evident among raw, cooked and bags odorous profiles. The highest values were found in cooked samples and the broad range class (W5S) was the most representative. The EN also recognized the two tested feed treatments. In the cooked samples, all sensor responses decrease while time enhances, indicating a progressive chemical variation of the air composition in the bag, with a less correlation shown in the raw samples. When using bags, to avoid bias, is important to fix analysis in order to obtain useful results.

  8. Diffusive sampling and measurement of microbial volatile organic compounds in indoor air.

    PubMed

    Araki, A; Eitaki, Y; Kawai, T; Kanazawa, A; Takeda, M; Kishi, R

    2009-10-01

    Microbial volatile organic compounds (MVOC), chemicals emitted from various microorganisms, in indoor air have been of concern in recent years. For large field studies, diffusive samplers are widely used to measure indoor environments. Since the sampling rate of a sampler is a fundamental parameter to calculate concentration, the sampling rates of eight MVOC with diffusive samplers were determined experimentally using a newly developed water-bubbling method: air was supplied to the MVOC-solutions and the vapor collected in an exposure bag, where diffusive and active samplers were placed in parallel for comparison. Correlations between the diffusive and active samplings gave good linear regressions. The sampling rates were 30-35 ml/min and the detection limits were 0.044-0.178 microg/m(3), as determined by GC/MS analysis. Application of the sampling rates in indoor air was validated by parallel sampling of the diffusive and active sampling method. 5% Propan-2-ol/CS(2) was the best solvent to desorb the compounds from absorbents. The procedure was applied to a field study in 41 dwellings. The most frequently detected compounds were hexan-2-one and heptan-2-one, with 97.5% detection rates and geometric mean values of 0.470 and 0.302 microg/m(3), respectively. This study shows that diffusive samplers are applicable to measure indoor MVOC levels. Practical Implications At present, there are still limited reports on indoor Microbial Volatile Organic Compounds (MVOC) levels in general dwellings and occupants' health. Compared with active sampling methods, air sampling using a diffusive sampler is particularly advantageous for use in large field studies due to its smallness, light-size, easy-handling, and cost-effectiveness. In this study, sampling rates of selected MVOC of the diffusive sampler were determined using the water-bubbling method: generating gases by water-bubbling and exposing the diffusive and active samplers at the same time. The obtained sampling rates

  9. HEPA filter dissolution process

    SciTech Connect

    Brewer, K.N.; Murphy, J.A.

    1992-12-31

    This invention is comprised of a process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

  10. Hepa filter dissolution process

    DOEpatents

    Brewer, Ken N.; Murphy, James A.

    1994-01-01

    A process for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal.

  11. HEPA filter dissolution process

    DOEpatents

    Brewer, K.N.; Murphy, J.A.

    1994-02-22

    A process is described for dissolution of spent high efficiency particulate air (HEPA) filters and then combining the complexed filter solution with other radioactive wastes prior to calcining the mixed and blended waste feed. The process is an alternate to a prior method of acid leaching the spent filters which is an inefficient method of treating spent HEPA filters for disposal. 4 figures.

  12. 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

  13. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  14. Image-domain sampling properties of the Hotelling Observer in CT using filtered back-projection

    NASA Astrophysics Data System (ADS)

    Sanchez, Adrian A.; Sidky, Emil Y.; Pan, Xiaochuan

    2015-03-01

    The Hotelling Observer (HO),1 along with its channelized variants,2 has been proposed for image quality evaluation in x-ray CT.3,4 In this work, we investigate HO performance for a detection task in parallel-beam FBP as a function of two image-domain sampling parameters, namely pixel size and field-of-view. These two parameters are of central importance in adapting HO methods to use in CT, since the large number of pixels in a single image makes direct computation of HO performance for a full image infeasible in most cases. Reduction of the number of image pixels and/or restriction of the image to a region-of-interest (ROI) has the potential to make direct computation of HO statistics feasible in CT, provided that the signal and noise properties lead to redundant information in some regions of the image. For small signals, we hypothesize that reduction of image pixel size and enlargement of the image field-of-view are approximately equivalent means of gaining additional information relevant to a detection task. The rationale for this hypothesis is that the backprojection operation in FBP introduces long range correlations so that, for small signals, the reconstructed signal outside of a small ROI is not linearly independent of the signal within the ROI. In this work, we perform a preliminary investigation of this hypothesis by sweeping these two sampling parameters and computing HO performance for a signal detection task.

  15. Test report for initial test of 6266 Building filter assemblies

    SciTech Connect

    Prather, M.C.

    1994-08-01

    This is the test report for the initial test of the Waste Sampling and Characterization Facility (WSCF) 6266 Building high efficiency particulate air (HEPA) filter assemblies. This supports the start-up of WSCF.

  16. Short communication: measurements of methane emissions from feed samples in filter bags or dispersed in the medium in an in vitro gas production system.

    PubMed

    Ramin, M; Krizsan, S J; Jančík, F; Huhtanen, P

    2013-07-01

    The objective of this study was to compare methane (CH4) emissions from different feeds when incubated within filter bags for in vitro analysis or directly dispersed in the medium in an automated gas in vitro system. Four different concentrates and 4 forages were used in this study. Two lactating Swedish Red cows were used for the collection of rumen fluid. Feed samples were milled to pass a 1.0-mm screen. Aliquots (0.5 g) of samples were weighed directly in the bottles or within the F 0285 filter bags that were placed in the bottles. Gas samples were taken during 24 and 48 h of incubation, and CH4 concentration was determined. The data were analyzed using a general linear model. Feeds differed significantly in CH4 emission both at 24 and at 48 h of incubation. The interaction between feed and method on methane emission in vitro was significant, indicating that the ranking of feeds was not consistent between the methods. Generally, greater amounts of CH4 were emitted from samples directly dispersed in the medium compared with those incubated within the filter bags, which could be a result of lower microbial activity within the filter bags. The ratio of CH4 to total gas was greater when the feeds were incubated within bags compared with samples directly dispersed in the medium. Incubating samples in filter bags during 48 h of incubation cannot be recommended for determination of CH4 emission of feeds in vitro. PMID:23628246

  17. Rapid sampling of local minima in protein energy surface and effective reduction through a multi-objective filter

    PubMed Central

    2013-01-01

    Background Many problems in protein modeling require obtaining a discrete representation of the protein conformational space as an ensemble of conformations. In ab-initio structure prediction, in particular, where the goal is to predict the native structure of a protein chain given its amino-acid sequence, the ensemble needs to satisfy energetic constraints. Given the thermodynamic hypothesis, an effective ensemble contains low-energy conformations which are similar to the native structure. The high-dimensionality of the conformational space and the ruggedness of the underlying energy surface currently make it very difficult to obtain such an ensemble. Recent studies have proposed that Basin Hopping is a promising probabilistic search framework to obtain a discrete representation of the protein energy surface in terms of local minima. Basin Hopping performs a series of structural perturbations followed by energy minimizations with the goal of hopping between nearby energy minima. This approach has been shown to be effective in obtaining conformations near the native structure for small systems. Recent work by us has extended this framework to larger systems through employment of the molecular fragment replacement technique, resulting in rapid sampling of large ensembles. Methods This paper investigates the algorithmic components in Basin Hopping to both understand and control their effect on the sampling of near-native minima. Realizing that such an ensemble is reduced before further refinement in full ab-initio protocols, we take an additional step and analyze the quality of the ensemble retained by ensemble reduction techniques. We propose a novel multi-objective technique based on the Pareto front to filter the ensemble of sampled local minima. Results and conclusions We show that controlling the magnitude of the perturbation allows directly controlling the distance between consecutively-sampled local minima and, in turn, steering the exploration towards

  18. Greenhouse gas analysis of air samples collected onboard the CARIBIC passenger aircraft

    NASA Astrophysics Data System (ADS)

    Schuck, T. J.; Brenninkmeijer, C. A. M.; Slemr, F.; Xueref-Remy, I.; Zahn, A.

    2009-08-01

    CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) is a long-term atmospheric measurement program based on the use of a comprehensive scientific instrument package aboard a commercial passenger aircraft. In addition to real-time measurements, whole air sampling is performed regularly at cruising altitudes in the tropical middle troposphere and the extra-tropical UT/LS region. Air samples are analyzed for greenhouse gases, NMHCs, halocarbons, and trace gas isotopic composition. The routinely performed greenhouse gas analysis comprises gas chromatography measurements of CO2, CH4, N2O and SF6. The air sampling procedure, the GC system and its performance are described. Comparisons with similar systems employed in other laboratories and a comparison with results from a CO2 in-situ analyzer that is also part of the CARIBIC instrumentation are shown. In addition, the time series of CO2, obtained from the collection of 684 samples at latitudes between 30° N and 56° N on 21 round trips out of Germany to different destinations in Asia between November 2005 and October 2008, is presented. A time shift in the seasonal cycle of about one month was observed between the upper troposphere and the tropopause region. For two sets of return flights from Germany to the Philippines the relationship between the four greenhouse gases is briefly discussed.

  19. Detection of Legionella spp. by a nested-PCR assay in air samples of a wastewater treatment plant and downwind distances in Isfahan

    PubMed Central

    Mirzaee, Seyyed Abbas; Nikaeen, Mahnaz; Hajizadeh, Yaghob; Nabavi, BiBi Fatemeh; Hassanzadeh, Akbar

    2015-01-01

    Background: Wastewater contains a variety of pathogens and bio -aerosols generated during the wastewater treatment process, which could be a potential health risk for exposed individuals. This study was carried out to detect Legionella spp. in the bio -aerosols generated from different processes of a wastewater treatment plant (WWTP) in Isfahan, Iran, and the downwind distances. Materials and Methods: A total of 54 air samples were collected and analyzed for the presence of Legionella spp. by a nested- polymerase chain reaction (PCR) assay. A liquid impingement biosampler was used to capture bio -aerosols. The weather conditions were also recorded. Results: Legionella were detected in 6% of the samples, including air samples above the aeration tank (1/9), belt filter press (1/9), and 250 m downwind (1/9). Conclusion: The result of this study revealed the presence of Legionella spp. in air samples of a WWTP and downwind distance, which consequently represent a potential health risk to the exposed individuals. PMID:25802817

  20. Evaluation of HEPA filter service life

    SciTech Connect

    Fretthold, J.K.; Stithem, A.R.

    1997-07-14

    Rocky Flats Environmental Technology Site (RFETS), has approximately 10,000 High Efficiency Particulate Air (HEPA) Filters installed in a variety of filter plenums. These ventilation/filtration plenum systems are used to control the release of airborne particulate contaminates to the environment during normal operations and potential accidents. This report summarizes the results of destructive and non-destructive tests on HEPA filters obtained from a wide variety of ages and service conditions. These tests were performed to determine an acceptable service life criteria for HEPA filters used at Rocky Flats Environmental Technology Site (RFETS). A total of 140 filters of various ages (1972 to 1996) and service history (new, aged unused, used) were tested. For the purpose of this report, filter age from manufacture date/initial test date to the current sample date was used, as opposed to the actual time a filter was installed in an operating system.